JPH07199532A - Manufacture of electrostatic image developing toner - Google Patents

Abstract

PURPOSE:To provide a manufacturing method for the electrostatic latent image developing toner small in particle diameter and narrow in particle diameter distribution and high in fluidity, releasability, transferability, fixability, durability, storage stability, and the like and capable of forming a sharp image. CONSTITUTION:The electrostatic image developing toner is formed by fixing fine releasing agent particles A to the surfaces of core particles B composed essentially of a colorant and a thermoplastic resin. The particles A are fixed by attaching the particles A to the surfaces of the particles B in a liquid dispersion medium C and then, swelling the particles B to bury the particles A into the particles B and to fix the particles A to the particles B, or attaching the particles A to the particles B in the medium C capable of swelling the particles B and burying the particles A into the particles B to fix the particles A to the particles B.

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 a toner for electrostatic charge development used in electrophotography, electrostatic printing, electrostatic recording and the like.

[0002]

2. Description of the Related Art Generally, in an electrophotographic method, an electrostatic printing method or the like, an appropriately charged toner is used to develop an electrostatic latent image formed on a latent image carrier by various methods. Then, the toner image is transferred to a material to be copied such as paper, if necessary, and then fixed by heating, pressure or the like to obtain a copy.

As a means for developing an electrostatic latent image formed on an electrophotographic photoreceptor or an electrostatic recording body, a dry developing method is often used at present. In the dry development method, a toner in which a colorant such as a dye and pigment is dispersed in a binder resin and, if necessary, a release agent, a charge control agent, etc. is used, and this toner is brought into contact with a charging member such as a blade or a roller. Then, the toner is charged to form a thin layer on a roller or the like, and the toner is mixed with a magnetic powder carrier by a one-component developing method in which the electrostatic latent image is developed by bringing the electrostatic latent image close to or in contact with the electrostatic latent image. There is a two-component developing method in which an electrostatic latent image is developed by contacting the electrostatic latent image with a magnet brush by applying a charge to the electrostatic latent image. In either case, the charge applied to the toner needs to be uniform and of an appropriate amount.

Recently, a toner having high image quality and high durability has been demanded. For this purpose, the toner is required to have a small particle size, a narrow particle size distribution, a smooth surface shape, and a charge control agent uniformly dispersed. That is, the particle size affects resolution, sharpness, halftone reproducibility, and the like, and if the particle size distribution is wide, selective development of a specific particle size occurs, and durability is impaired. If the surface shape is not smooth, due to the stress when stirring the developing section, partial pulverization occurs on the surface and ultrafine powder is generated,
In the two-component developer, it causes fusion to the carrier and deterioration of charge, and in the one-component developer, fusion to the member for the toner thin film occurs, which causes white stripes.

As a method of fixing the toner image transferred from the latent image carrier onto the material to be copied, a pressure heating method using a heating roller is generally used. This method has good thermal efficiency and is capable of high-speed fixing, but a part of the toner image adheres to the surface of the heat roller because the surface of the heat roller and the toner image are in contact with each other under pressure in a molten state. The toner may adhere to the material to be fixed again to cause so-called offset development that contaminates the copied image. For the purpose of preventing this phenomenon, the surface of the fixing roller is formed of silicone rubber or fluororesin having excellent releasability to toner, and a releasable liquid such as silicone oil is supplied to the surface. This method is extremely effective in preventing toner offset, but the offset preventing liquid heats and evaporates to give an unpleasant odor, and a device for supplying the offset preventing liquid is required. There was a problem. In order to solve this, there is a method of containing a resin having a releasing property in the toner (Japanese Patent Publication No. 52-3304). However, in this internal addition method, the releasing agent must be contained in a relatively large amount in the toner. I can't get enough effect,
Due to the poor compatibility of the binder resin and the release agent, it is difficult to uniformly mix and disperse them.

Furthermore, a conventional general method for producing a toner, that is, a resin, a dye / pigment, a release agent, and a charge control agent are melt-kneaded, and pulverized and classified by a mechanical or air collision type pulverizer. In the toner manufactured by the method described above, particularly when it is attempted to obtain a toner having a small particle size and a narrow particle size distribution, not only the production capacity and the yield are significantly lowered, but also the cost is increased.
As the particle size is made smaller, the toner charging characteristics become poor due to non-uniform dispersion of the internal additive. In addition, the surface shape of the particles obtained by pulverization has many protrusions, and fusion with the carrier or the toner thinning member is likely to occur. Furthermore, since an expensive charge control agent or the like, which originally has a function on the surface of the toner, is also contained in the toner, there is a drawback that the cost becomes high.

In order to solve these problems, Japanese Patent Laid-Open No. 63-
11955, JP-A-63-30861, JP-A-63
No. 61265, JP-A No. 63-244053 and the like disclose a toner in which a release agent layer using a release agent such as low melting point wax and polyolefin is provided on the outer layer of the toner, and a method for producing the toner. However, it is difficult to obtain the release agent fine particles used for this, and since the surface of this toner is covered with the release agent having a low molecular weight, the fluidity of the toner is significantly deteriorated and the toner supply in the developing section However, there is a problem in that the toner cannot be smoothly transferred, or that the toner cannot be smoothly transferred from the latent image carrier to the copy material.

Further, Japanese Patent Laid-Open No. 63-300245 discloses a toner in which a toner is mixed with a water-based release agent wax emulsion to fix release agent fine particles, and wax fine particles are easily obtained by this method. However, this toner not only has a problem in fluidity and transferability as described above, but also the release agent is released in the developer to cause the release property to be lost. There is a problem that fine particles contaminate the carrier and the photoconductor. Further, a toner having these release agents fixed on the surface requires a large amount of a fluidizing agent such as an inorganic fine powder in order to obtain sufficient fluidity and transferability.
There is a problem that the fluidizing agent has a bad influence such as streak-shaped image omission due to the adhesion to the photoconductor or the like.

In order to solve these problems, Japanese Patent Laid-Open No. 1-18
566, JP-A 1-257853, JP-A 3-12
No. 5156 discloses a toner in which fine resin particles containing a release agent are prepared and fixed on the toner surface. However, since the release agent is coated with resin, the fluidity and transferability of the toner are What is improved, not only is the process of obtaining fine resin particles containing a release agent extremely complicated, but there is also the problem that sufficient release properties cannot be obtained because the release agent is coated with resin. .

Further, Japanese Patent Application Laid-Open No. 2-264266 discloses a method of fixing a mixture of resin fine particles and release agent fine particles on the toner surface by a mechanical impact force. In this method, the mixture is separated by a mechanical impact force. There is a problem that the patterning agent fine particles are rolled on the toner surface and the fluidity and transferability of the toner are not sufficiently improved. In addition, JP-A-4-182661,
JP-A-4-182666 discloses a method in which resin fine particles and release agent fine particles are adhered to the toner surface and treated with a solvent that dissolves the resin fine particles to form a coating layer containing a release agent. This method has a problem in that the processing steps are complicated, and that the release agent is covered with the resin to improve the fluidity and transferability of the toner, but sufficient release characteristics cannot be obtained.

[0011]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for producing an electrostatic charge developing toner which solves the above problems. That is, 1) the release agent fine particles are embedded and fixed on the surface of the toner to prevent an offset phenomenon and a trace of a separation claw that separates the fixing roller and the fixing material from remaining on the image, and 2) the release property. Prevents release of releasing agents and contamination of other materials due to direct contact of substances with other members. 3) Releasing agents do not affect toner chargeability and reduce toner fluidity. A toner that forms a high-quality image with excellent transferability, excellent resolving power, and excellent image reproducibility, and has uniform charging performance, stability of charge amount over time, and environmental changes. Provided is a method for producing a highly reliable toner for electrostatic charge development, which is excellent in stability.

[0012]

According to the present invention, firstly, a method for producing a toner for electrostatic charge development in which fine particles of a release agent are fixed to the surfaces of core particles containing a colorant and a binder resin as main components. In the liquid dispersion medium, the release agent fine particles are adhered to the core particles, and then the core particles are swollen to embed and fix the release agent fine particles on the surface of the core particles. Secondly, in a method for producing a toner for electrostatic charge development, wherein release agent fine particles are fixed to the surface of core particles mainly composed of a colorant and a binder resin, the core particles are swollen. In the liquid, release agent particles are attached to the core particles,
Provided is a method for producing a toner for electrostatic charge development, which comprises fixing by embedding, and thirdly, the method for producing a toner for electrostatic charge development as described above, wherein the fixing is performed in the presence of inorganic fine particles. Fourthly, a method is provided, and fourthly, the inorganic fine particles are hydrophobic silica, and the addition amount thereof is 0.2 to 0.8 parts by weight with respect to 100 parts by weight of the core particles. A method for producing the toner for electrostatic charge development described above is provided. Fifthly, there is provided a method for producing the toner for electrostatic charge development described above, characterized in that heating is performed when the core particles are swollen. In item 6, there is provided the method for producing a toner for electrostatic charge development as described above, wherein the embedded fixing is performed in the presence of a nonionic surfactant.

According to the above-mentioned manufacturing method of the present invention, in the obtained toner for electrostatic charge development, the release agent fine particles are uniformly adhered to the surface of the colored resin particles (core particles), and the release agent is used. The fine particles are not spread, and are embedded and fixed in the state of fine particles on the surface of the core particles (that is, the core particles are not in a state of being covered with the release agent), and the release agent fine particles are projected on the toner surface. Since it is not in a state, contact between the release agent present on the toner surface and contact between the release agent and the photoconductor or the carrier can be prevented, and deterioration of toner fluidity and transferability can be prevented. The release agent fine particles are not detached even by stirring in the agent, and a durable toner can be obtained without contaminating the photoconductor and the carrier, and the durability of the developer can be improved. it can. Further, since the fine particles of the release agent are uniformly distributed near the toner surface, the release agent is easily and uniformly eluted on the toner surface by heating the fixing roller, and an offset prevention effect and a separation nail mark prevention effect are exhibited. be able to.

Further, in the toner produced by the method performed in the presence of the above-mentioned inorganic fine particles, the inorganic fine particles are uniformly embedded and fixed together with the release agent fine particles on the surface of the core particles, and the fixed amount is very small. The effect is further improved without affecting the moldability and fixability, and in the production method thereof, when the release agent particles are embedded and fixed, the core particles swell to increase the tackiness and melt. Adhesion, aggregation, and coalescence easily occur, but the presence of the inorganic fine particles prevents the fusion, aggregation, and coalescence, does not require a special inorganic fine particle adhesion step, and has a narrow particle size distribution efficiently. Can be manufactured.

The first method for producing an electrostatic charge developing toner of the present invention is a thermoplastic resin particle (core particle) containing a colorant.
(I-), a step of adhering release agent fine particles to the toner surface (I-), a step of embedding and fixing the release agent fine particles on the toner surface (I-), and separating and drying the obtained toner. The step (I-) is performed.

In the second method for producing a toner for electrostatic charge development of the present invention, the step (II-) of producing core particles, the release agent fine particles are preferably embedded together with the inorganic fine particles on the surface of the toner and embedded at the same time. It comprises a step (II-) of fixing and a step (II-) of separating and drying the obtained toner. Hereinafter, each step will be described in detail.

[I] Formation of Colorant-Containing Resin Particles (Core Particles) (Step I- of First Production Method and Step II- of Second Production Method) The core particles used in the present invention are conventional colorants. Particles obtained by kneading and pulverizing a binder resin and a binder resin, particles obtained by suspension polymerization of a colorant-containing monomer, etc. can be used, but particles having a small particle size and a narrow particle size distribution can be easily obtained. From the viewpoint of obtaining, it is preferable to use particles obtained by dispersion polymerization. Dispersion polymerization is a method in which a vinyl monomer is dissolved but a polymer formed therefrom is not dissolved in a solvent in the presence of a dispersion stabilizer which is soluble in the solvent.

As the vinyl monomer used at this time, those known in the electrophotographic field are used, for example, styrene and O-.
Methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-ethyl styrene, 2,
4-dimethylstyrene, pn-butylstyrene, p-
tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy styrene, p-phenyl styrene, p
-Styrenes such as chlorostyrene and 3,4-dichlorostyrene, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, acrylic acid Lauryl, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-chloromethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate. , N-octyl methacrylate, dodecyl methacrylate, lauryl methacrylate, 2-methacrylic acid
Α-Methyl fatty acid monocarboxylic acid esters such as ethylhexyl, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, acrylonitrile, methacrylonitrile, acrylic acid or methacrylic acid derivatives such as acrylamide, vinyl chloride , Vinylidene chloride,
Examples thereof include halogen vinyls such as vinyl bromide and vinyl fluoride, and mixtures of two or more thereof.

Further, the polymer in the present invention may be one obtained by polymerizing in the presence of a so-called cross-linking agent having two or more polymerizable double bonds in order to enhance offset resistance, and then cross-linking and polymerizing. As the cross-linking agent preferably used, divinylbenzene, divinylnaphthalene and aromatic divinyl compounds which are derivatives thereof, other ethylene glycol dimethacrylate, diethylene glycol methacrylate, triethylene glycol methacrylate, trimethylolpurpan triacrylate, allyl methacrylate, tetraethylene glycol Dimethacrylate,
Diethylenic carboxylic acid esters such as 1,3-butanediol dimethacrylate, all divinyl compounds such as N, N-divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone and compounds having three or more vinyl groups, alone or 2 A mixture of two or more species is used.

In particular, the core particles containing the THF insoluble matter, which are partially crosslinked by adding the above-mentioned crosslinking agent at the time of polymerization, do not remarkably increase the adhesiveness of the resin particles caused by the swelling by the solvent, and the release agent fine particles are embedded. It is preferably used because the aggregation of core particles at that time can be reduced.

Further, for the purpose of controlling the average molecular weight, polymerization may be carried out in the presence of a compound having a large continuous transfer constant. For example, a low molecular weight compound having a mercapto group, carbon tetrachloride, carbon tetrabromide and the like can be mentioned.

As the polymerization initiator of the above-mentioned monomer, for example, 2,2'-azobisisobutyronitrile,
Azo-based polymerization initiators such as 2,2′-azobis (2,4-dimethylvaleronitrile), lauryl peroxide,
Peroxide-based polymerization initiators such as benzoyl peroxide and tert-butyl peroctoate, persulfide-based initiators such as potassium persulfate, or systems in which sodium thiosulfate, amine, etc. are used in combination are used. . The concentration of the polymerization initiator is 0.1 to 100 parts by weight of vinyl monomer.
10 parts by weight is preferred.

The solvent is preferably a hydrophilic organic liquid,
For example, methyl alcohol, ethyl alcohol, denatured ethyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, tert-butyl alcohol, sec-butyl alcohol, tert-amyl alcohol, 3-pentanol, octyl alcohol, benzyl alcohol, cyclohexanol. , Furfuryl alcohol, tetrahydrofurfuryl alcohol,
Alcohols such as ethylene glycol, glycerin, and diethylene glycol, methyl cellosolve, cellosolve,
Examples include ether alcohols such as isopropyl cellosolve, butyl cellosolve, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, and diethylene glycol monoethyl ether. If necessary, water or a soluble lipophilic liquid may be mixed with these hydrophilic organic liquids before use. The ratio of the monomer and hydrophilic organic liquid used is the value of monomer / hydrophilic organic liquid
Approximately 1 or less, preferably 1/2 or less is suitable.

As the dispersion stabilizer, a homopolymer of a monomer having a hydrophilic group or a copolymer of this and another polymerizable monomer, which is soluble in a hydrophilic organic liquid, is preferably used. . Examples of the monomer having a hydrophilic group include acrylic acid, methacrylic acid, fumaric acid, maleic acid, maleic anhydride, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, glycerin monoacrylic ester, glycerin mono Methacrylic acid ester, vinyl alcohol, vinyl methyl ether, vinyl ethyl ether, vinyl acetate, vinyl propionate, acrylamide, methacrylamide, vinyl pyridine, vinyl pyrrolidone, vinyl imidazole, ethylene imine and the like.
The amount of the dispersion stabilizer used varies depending on the kind of the polymerizable monomer for forming the intended polymer particles, but is 0.1 to 10% by weight, more preferably 1 to 5% by weight with respect to the hydrophilic organic liquid. preferable.

The particles are manufactured by completely dissolving the polymer dispersion stabilizer in the hydrophilic organic liquid, adding one or more vinyl monomers, and then inertizing nitrogen, argon, etc. in the reaction vessel. After the gas is replaced, a polymerization initiator is added, and the polymerization is carried out by heating at a temperature corresponding to the decomposition rate of the used initiator while stirring at a rate such that the flow in the tank becomes uniform. It takes 5 to 40 hours to carry out the polymerization in a high polymerization rate range. However, the polymerization may be stopped in a desired particle size and particle size distribution state, or a polymerization initiator may be added sequentially. The polymerization rate can be increased by carrying out the reaction under high pressure. After completion of the polymerization, it may be used in the dyeing step as it is, or after removing unnecessary fine particles, residual monomers, polymer dispersion stabilizer, etc. by operations such as sedimentation, centrifugation, decantation, etc. The dye may be collected as a combined slurry and dyed, but if the dispersion stabilizer is not removed, the stability of the dyeing system is high and unnecessary aggregation is suppressed.

The dyeing in the present invention is as follows. The resin particles can be colored resin particles by fixing a colorant such as a pigment on the surface, but it is preferable to color the resin particles with a dye from the viewpoint of fixing property. That is, the resin particles are dispersed in an organic solvent which does not dissolve the resin particles, and before or after the dye is dissolved in the solvent, the dye is permeated into the resin particles and colored, and then the organic solvent is added. Are removed to produce a dyed toner. As the dye, it is preferable that the SP value of the dye and the SP value of the resin are close to each other, and the relationship between the solubility [D ₁ ] of the dye in the organic solvent and the solubility [D ₂ ] of the resin particle in the resin [D ₂ ]. , [D ₁ ]
It is preferable to selectively use a dye satisfying / [D ₂ ] ≦ 0.5, whereby a toner in which the dye penetrates (diffuses) to the deep part of the resin particles can be efficiently produced. It is preferable to keep the liquid temperature below the glass transition temperature of the resin particles and stir. As a result, the permeation rate of the dye into the resin particles can be increased, and it takes about 30 minutes to 6 minutes.
It is possible to obtain sufficiently colored resin particles in about the time.

Further, a dye is directly added to a slurry obtained at the end of polymerization by dispersion polymerization, that is, a dispersion liquid in which polymerized resin particles are dispersed in an organic solvent, and the mixture is heated and stirred under the above conditions. Good.

As the dyes, vat dyes, disperse dyes and oil-soluble dyes are preferably used, and oil-soluble dyes are particularly preferable.
Further, several kinds of dyes can be used together depending on the desired color tone. Ratio of dye to be dyed and resin particles (weight)
Is optionally selected according to the degree of coloring, but it is usually preferable to use 1 to 50 parts by weight of the dye per 100 parts by weight of the resin particles.

For example, when an alcohol having a high SP value such as methanol or ethanol is used as the dyeing solvent and a styrene-acrylic resin having an SP value of about 9 is used as the resin particles, dyes usable include, for example, The following dyes may be mentioned. C. I. SOLVENT YELLOW (6,9,1
7, 31, 35, 100, 102, 103, 105) C.I. I. SOLVENT orange (2,7,1
3, 14, 66) C.I. I. SOLVENT RED (5,16,17,1
8, 19, 22, 23, 143, 145, 146, 14
9, 150, 151, 157, 158) C.I. I. SOLVENT VIOLET (31, 32,
33, 37) C.I. I. SOLVENT BLUE (22, 63, 7
8, 83-86, 91, 94, 95, 104) C.I. I. SOLVENT GREEN (24, 25) C.I. I. SOLVENT BROWN (3,9) etc.

Examples of commercially available dyes include Aizen SOT dyes Yellow-1,3,4, Orange of Hodogaya Chemical Co., Ltd.
e-1, 2, 3, Scarlet-1, Red-1,
2,3, Brown-2, Blue-1,2, Viol
et-1, Green-1, 2, 3, Black-1,
4,6,8 and BASF sudan dye, Yellow
w-140, 150, Orange-220, Red-
290, 380, 460, Blue-670 and Mitsubishi Kasei's dialresin, Yellow-3G, F, H2G,
HG, HC, HI, Orange-HS, G, Red-
GG, S, HS, A, K, H58, Violet-D,
Blue-J, G, N, K, P, H3G, 4G, Gre
en-C, Brown-A and oil colors of Orient Chemical Co., Yellow-3G, GG-S, # 10.
5, Orange-PS, PR, # 201, Scarl
et- # 308, Red-5B, Brown-GR, #
416, Green-BG, # 502, Blue-BO
S, HN, Black-HBB, # 803, EE, E
X, Sumiplast from Sumitomo Chemical Co., Ltd., Blue GP, OR
Red FB, 3B, Yellow FL7G, GC, Nippon Kayaku's Caroyan, Polyester Black EX-SH30
0, Kayaset Red-B blue A-2R and the like can be used. Of course, the dye is not limited to the above examples because it is appropriately selected depending on the combination of the resin particles and the solvent used for dyeing.

[II] Adhesion of release agent fine particles, fixing by embedding (step I- of the first production method, and step II- of the second production method) The release agent fine particles are added to the colored resin particles (core particles). In order to uniformly attach the particles, the release agent fine particles can have a particle size of about 1/10 times the particle diameter of the core particles, but in order to efficiently embed and fix the particles on the surface of the core particles, it is 1/20 or less. Is preferred. In order to embed more efficiently and improve the transfer rate, 0.1 μm is required regardless of the particle size of the core particles.
It is preferably m or less. Release agent fine particles are core particles 1
It is preferable to attach 1 to 5 parts by weight to 00 parts by weight. If the amount is less than 1 part by weight, the effective releasability cannot be exhibited, and if the amount is more than 5 parts by weight, the fluidity and transferability of the toner are insufficient. Hereinafter, the adhesion and embedding of the release agent particles to the core particles in the first and second manufacturing methods will be described in more detail.

Adhesion of Release Agent Fine Particles (Step I- of First Production Method) When the release agent fine particles are attached to the core particles, a method of simply mixing both particles produces particularly release agent fine particles. It is difficult to adhere uniformly because it is difficult to mix uniformly without agglomerates. In order to embed and fix the release agent fine particles according to the present invention on the surface of the core particles, it is necessary to attach the release agent fine particles uniformly without agglomerates. For this purpose, it is necessary to carry out the attaching step in a dispersed state.
Further, in order to adhere in a dispersed state, core particle powder may be added to the release agent fine particle dispersion liquid, but mixing the release agent fine particle dispersion liquid and the core particle dispersion liquid is more uniform without aggregation. It is preferable because it can be mixed with.

The method for obtaining the release agent fine particle dispersion is, for example, as shown below, and it is also available as a commercial product. 1. A method in which a solvent a which dissolves the release agent fine particles and a liquid b which is compatible with a but does not dissolve the release agent fine particles are used, and the release agent fine particles are dissolved in a and then added to b which is stirred at a high speed to cause precipitation. ． 2. A method for obtaining a dispersion of release agent fine particles by adding hot water to a liquid obtained by heat-melting a release agent while stirring at high speed to cool the obtained dispersion. It is possible to use a generally known method such as a method in which the liquid c which does not dissolve the release agent fine particles and the release agent fine particles are mixed and dispersed in the liquid by using a dispersing device such as a ball mill. Further, these dispersions may contain generally known surfactants, polymer dispersants, inorganic ions and the like as dispersion stabilizers, alone or in combination.

The release agent fine particles referred to herein may be any substance as long as it is a substance which is melted at the time of fixing the heat roller and has an effect of preventing the adhesion of the toner on the heat roller and the material to be fixed,
That is, it means all substances having the effect of preventing the above-mentioned offset phenomenon. Specific examples of these substances include polypropylene, polyethylene, polypropylene oxide,
The number average molecular weight of polyethylene oxide is 1000 to 200.
00 low molecular weight polyolefin, candelilla, carnauba, rice, roe, jojoba and other plant-based natural waxes, mineral-based waxes such as montan, ceresin and ozokerite, and petroleum-based waxes such as paraffin, microcrystalline and petrilactam, and Its modified wax.
Solid higher fatty acids such as palmitic acid, stearic acid and behenic acid, higher fatty acid alkali metal salts such as calcium stearate, aluminum stearate, calcium palmitate and zinc palmitate, zinc salts, aluminum salts,
Higher fatty acid esters such as octadecyl stearate and glycerin monostearate, lauric acid amides, stearic acid amides, amides such as N, N′-ethylenebisoleic acid amides, N, N′-ethylenebisstearic acid amides. Examples thereof include ketones such as diheptadecyl ketone and diundecyl ketone.

Adhesion of the release agent fine particles to the colored resin particles (core particles) may occur simply by mixing, but in the present invention, they can be firmly attached by any of the following methods. . As the attachment method, there are (1) a method of adding an acid or alkali to adjust the pH, (2) a method of adding an anionic surfactant or a cationic surfactant, and (3) a method of adding an electrolyte. By these methods, by appropriately setting the conditions, the potentials of the colored resin particles and the release agent fine particles in the dispersion liquid have opposite polarities, or even if the polarities are the same, the release agent fine particles are formed by increasing the potential difference. It is possible to produce a core particle dispersion liquid that is uniformly attached to the surface. The adjustment of these potentials may be performed before mixing both dispersion liquids, or may be performed after mixing them.

By adjusting these potentials, the dispersion stability of the core particles is sometimes impaired and aggregation easily occurs. However, the addition of the nonionic surfactant sterically stabilizes the core particles, and the adhesion operation can be performed without aggregation. It is possible because it is possible. Further, the nonionic surfactant does not prevent the release agent particles from adhering. The amount of the nonionic surfactant added is 0.5 to 4 parts by weight, preferably 1 to 3 parts by weight, based on 100 parts by weight of the core particles. If it is less than 0.5 parts by weight, the effect of preventing aggregation is not sufficient, and if it is more than 4 parts by weight, the operation of removing the surfactant becomes complicated and the fluidity of the toner,
Transferability and chargeability may be reduced.

Examples of these nonionic surfactants include polyethylene glycol nonyl phenyl ether, polyethylene glycol octyl phenyl ether, polyethylene glycol lauryl ether, polyethylene glycol oleyl ether and polyethylene glycol tridecyl ether which are soluble in the liquid used as the dispersion medium. , Polyoxyethylene cetyl ether, polyoxyethylene stearyl ether, polyethylene glycol laurate, polyethylene glycol oleate, polyethylene glycol stearate, polyethylene glycol sorbitan laurate, polyethylene glycol sorbitan palmitate, polyethylene glycol sorbitan stearate, polyethylene glycol sorbitan oleate Ate etc. are illustrated

Buried fixation of release agent fine particles (step I- of the first production method) The release agent fine particles adhered to the core particles obtained in the above step are in a state of protruding on the surface. There is a high probability that the contact between the release agents will occur, and only a toner having poor transferability and durability can be obtained. Further, the release agent fine particles are easily released by stirring in the developer, and the photoreceptor and carrier are contaminated. Therefore, in the present invention, the release agent particles are embedded and fixed on the surface of the core particles after the step of attaching the release agent particles.
The term "embedded" as used herein refers to a state in which most of the volume of the release agent fine particles has entered the surface of the core particles and does not protrude to the surface. In this form, the cross section of the toner can be easily observed with a transmission electron microscope.

Such core particles in which the release agent fine particles are embedded cannot be obtained by heating the core particles to which the release agent fine particles are attached in a liquid such as water which does not swell the core particles. . To bring the core particles into a swollen state in the present invention,
(1) Add a liquid that swells the colored resin particles,
(2) The concentration of the liquid is increased, (3) heating is performed to promote swelling, and the like. Therefore, particularly in the present invention, the release agent fine particles can be easily embedded by treating in the liquid of the dispersion medium for swelling the core particles to which the release agent fine particles are adhered. In this case, the method of heating to promote swelling is simple in operation and can be effectively fixed by embedding. The heating temperature is preferably 30 ° C to 60 ° C. If the temperature is lower than 30 ° C, embedding is insufficient, and if the temperature is higher than 60 ° C, core particles are likely to be fused and bonded, which is not preferable. The heating time varies depending on the binder resin, the release agent, the dispersion medium, and the treatment temperature, but is preferably 2 hours to 10 hours.

Further, when the core particles are swollen, the tackiness of the particles is increased, and fusion and coalescence easily occur. Therefore, as described in the section of the release agent fine particle adhesion, the nonionic surfactant is used. It is possible to prevent fusion and fusion by addition of.
If it has already been added in the attaching step, it is not necessary to add it further. The liquid serving as a dispersion medium for swelling the core particles varies depending on the binder resin constituting the core particles, but contains alcohols such as methanol, ethanol, n-propyl alcohol, and isopropyl alcohol, and 50% by weight or more of these alcohols. Mixed solution with water, acetone,
An aqueous solution of methyl ethyl ketone or the like is preferably used.

Adhesion / Fixing of Release Agent Fine Particles (Step II- of Second Manufacturing Method) In the second production method of the present invention, the adhesion and embedding fixing of the releasing agent fine particles to the core particles are the releasing The adhesion of the agent fine particles and the embedding fixation are simultaneously and continuously performed in parallel. The release agent fine particles used in the second production method may be the same as those used in the first production method. Further, also in the second manufacturing method, similarly to the first manufacturing method, when the release agent particles are attached to the core particles and fixed by embedding, first, the release agent particles are attached. It can be carried out by the same processing means as in step I of the first production method, and a method of adding the release agent particle dispersion to the core particle dispersion and mixing is particularly preferable.

When the fine particles of the release agent are adhered, the potential is adjusted in the same manner as in the step I of the first manufacturing method.
By adjusting the potential, the dispersion stability of the core particles is impaired in some cases, and aggregation is likely to occur, but the aggregation can be prevented by attaching the release agent fine particles in the presence of the inorganic fine particles. It is considered that most of the inorganic fine particles are present in a dispersed state and are partially present on the surface of the colored resin particles, and both prevent the core particles from aggregating and fusing. Therefore, it is not preferable that the dispersed state of the inorganic fine particles is changed by the above-mentioned operation of attaching the release agent fine particles, and it is preferable that the dispersed state of the inorganic fine particles is kept good even by this operation. Further, the presence of the inorganic fine particles does not hinder the adhesion of the release agent fine particles.

The inorganic fine particles are insoluble in the liquid of the dispersion medium,
A particle size of 1 μm or less is preferable. These inorganic fine particles include silicon oxide, zinc oxide, aluminum oxide,
Oxides such as titanium oxide, sulfates such as barium sulfate and calcium sulfate, carbonates such as calcium carbonate and magnesium carbonate, phosphates such as calcium phosphate, bentonite,
Acid clay etc. are shown as a specific example. Further, as the inorganic fine particles, those subjected to a hydrophobic treatment with a silane coupling agent, a titanate coupling agent, silicone oil, a fatty acid, etc. are preferably used.

The amount of the inorganic fine particles added is 0.1 to 1 part by weight, more preferably 0.1 part by weight, relative to 100 parts by weight of the core particles.
2 to 0.8 parts by weight are added. If it is less than 0.1 part by weight, the effect of stabilizing the colored resin particles is small, and the effect of improving the fluidity and transferability of the toner is also small. If the amount is more than 1 part by weight, the effect of stabilizing the colored resin particles is sufficient, but the fixing property and releasing property of the toner are deteriorated, which is not preferable. Hydrophobic silica is particularly preferable as the inorganic fine particles, and the addition amount thereof is 0.1% with respect to 100 parts by weight of the core particles.
2 to 0.8 parts by weight is preferable.

Also when the inorganic fine particles are added, the release agent fine particles are adhered to the surface of the colored resin particles by the method described above. At this time, it is considered that most of the inorganic fine powder is in a dispersed state and a part thereof adheres to the surface of the colored resin particles to prevent cohesive fusion of the colored resin particles.

The inorganic fine powder is preferably added after being dispersed in the same or similar liquid as the liquid that is the dispersion medium of the core particle dispersion liquid. As a dispersing means, a ball mill, a sand mill,
It can be carried out by an ordinary dispersing device such as a pebble mill or a basket mill.

In order to accelerate the dispersion of the inorganic fine particles,
Further, in order to prevent the cohesive fusion of the colored resin particles, a nonionic surfactant may be added and dispersed. As the nonionic surfactant, those exemplified in Step I- of the first production method can be used. The nonionic surfactant may be added together with the inorganic fine particles when the release agent fine particles are attached. The core particles are sterically stabilized by the nonionic surfactant, aggregation and fusion can be further prevented, and a toner having a narrow particle size distribution can be efficiently produced. Further, the nonionic surfactant does not prevent the release agent particles from adhering. The amount of the nonionic surfactant added is the same as in step I- of the first production method.
Is the same as that described in. When the addition amount is in this range, the effect of preventing aggregation is sufficient, the operation of removing the surfactant is easy, and the toner has excellent fluidity, transferability, and chargeability, as described above.

The release agent particles are strongly embedded and fixed on the surface of the core particles so that the release agent particles will not be detached in the subsequent developer manufacturing process and in the developer. This embedding fixation is continuously performed at the same time as the adhesion. In order to strongly embed and fix the release agent fine particles, in the liquid for swelling the core particles, the surface of the core particles is swollen with the liquid to increase the adhesiveness and the release agent fine particles are embedded in the surface. It In order to bring the core particles into a swollen state, a method of (1) adding and presenting a liquid for swelling the colored resin particles, (2) increasing the concentration of the liquid, and (3) heating to promote swelling is carried out. .

Further, by making the surface of the core particles swelled, the tackiness of the particles increases and fusion / bonding easily occurs. However, by carrying out in the presence of the inorganic particles, the release agent particles can be adhered. Due to the same effect as the above, the fusion and coalescence can be prevented, and a toner having a narrow particle size distribution can be efficiently produced. In addition, by making the surface of the core particles swelled, coexisting inorganic fine particles are attached to the surface, the fluidity of the toner,
Transferability can be improved. The proportion of the added inorganic fine particles that adhere to the colored resin particles can be arbitrarily selected as necessary. This can be confirmed by fluorescent X-ray analysis after removing the free inorganic fine particles.

The liquid as a dispersion medium for swelling the colored resin particles (core particles) varies depending on the binder resin constituting the particles, but alcohols such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol and the like. A mixed solution with water containing 50% by weight or more of alcohols, an aqueous solution of acetone or methyl ethyl ketone, and the like are preferably used.

When heating to accelerate the swelling of the core particles, the heating temperature is the step I- of the first production method.
As in the case of, the temperature is preferably 30 to 60 ° C.

[III] Solid-Liquid Separation / Drying (Step I of First Manufacturing Method, Step of Second Manufacturing Method)
II-) After releasing the release agent particles or the inorganic particles with the release agent particles, free inorganic particles, release agent particle dispersion liquid, additives in the inorganic particle dispersion liquid, and surfactants added later are suction filtered. , Sedimentation by centrifugation, centrifugation, etc. Since the particles that have undergone the embedding treatment are in a swollen state and fusion of particles is likely to occur, it is preferable to perform solid-liquid separation after diluting the dispersion liquid with water after the embedding treatment to make it non-swelled.

Further, if necessary, free inorganic fine powder and other additives are redispersed in a liquid in which they can be dispersed / dissolved, washed, and then solid-liquid separated and dried by means such as vacuum drying and freeze drying. The toner of the invention can be obtained. Further, the particles may be used as a toner by being spray-dried or fluidized and dried in a state of being dispersed.

The toner obtained as described above may further be mixed with a fluidizing agent. The addition of the fluidizing agent further improves the fluidity and transferability of the toner. As the fluidizing agent, hydrophobic silica, inorganic fine powder such as silica, titanium oxide and zinc oxide, and fatty acid metal salt such as calcium stearate and zinc stearate are used. As a mixing method, a general mixing device such as a V blender or a Henschel mixer may be used.

When this toner is used as a two-component developer, it is used as a mixture with a carrier. Known carriers can be used, for example, iron, magnetite, hematite, powder having magnetism such as ferrite,
Examples thereof include glass beads. The particle size of these powders is 30
It is μm to 500 μm. In particular, a carrier in which these powders are coated with a silicone resin is preferably used. The toner is added to the carrier in an amount of 0.5% by weight to 5% by weight and mixed by the above-mentioned general mixing device to prepare a developer.

[0056]

EXAMPLES Next, the present invention will be described in more detail by way of examples. All “parts” and “%” shown below are based on weight.

(Production Example of Resin Particle Dispersion) Methyl vinyl ether / maleic anhydride copolymer (weight average molecular weight 4
0000) 7 parts was dissolved by heating in 100 parts of methanol to obtain a dispersion stabilizer solution. Dispersion stabilizer solution 250 parts styrene 60 parts methyl acrylate 40 parts dodecyl mercaptan 1 part 1,3-butanediol dimethacrylate 1.5 parts In a four-necked flask equipped with a stirrer, a cooling pipe, a nitrogen introduction pipe, and a thermometer. And purge the air completely with N ₂ gas to maintain the liquid temperature at 60 ° C.
, 2,2′-azobisisobutyronitrile 2.
Polymerization was started by adding 0 part, and the polymerization was carried out at 100 rpm for 24 hours with stirring and rotation. The resin particles thus obtained had a volume average diameter of 6.73 μm and a number average diameter of 6.600 μm at a particle number distribution of 50,000, and their ratio was 1.02, when measured with a Coulter Multisizer in a particle size distribution of 20 μm percher tube. . Further, the polymerization rate was measured by the gravimetric method and found to be 95.2%.

(Production Example of Colored Resin Particles- (a)) 6 parts of Oil Black 860 (manufactured by Orient Chemical Co., Ltd.) was added to the above resin particle dispersion and stirred at 50 ° C. for 2 hours, and then the dispersion was cooled to room temperature. After centrifugal sedimentation to remove the supernatant, redispersion in a mixed solvent of 50 parts of methanol and 50 parts of water was repeated three times, and after washing, suction filtration was performed, and this was dried under reduced pressure at 35 ° C. to obtain colored resin particles (core particles). Obtained.

(Production Example of Colored Resin Particles- (b)) 6 parts of Oil Black 860 (manufactured by Orient Chemical Co., Ltd.) was added to the above resin particle dispersion and stirred at 50 ° C. for 2 hours, and then the dispersion was cooled to room temperature. After centrifugal sedimentation to remove the supernatant and redispersion in a mixed solvent of 50 parts of methanol and 50 parts of water for three times and washing, the solid content concentration was adjusted to 30% in the dispersion medium having the above ratio, and the core was dispersed. A particle dispersion was obtained. Further, a part of this was suction filtered and then dried under reduced pressure to obtain colored resin particles (core particles).

(Production Example of Release Agent Fine Particle Dispersion) 26 parts of carnauba wax (No. 1) was gradually placed in a hermetically sealed container equipped with an agitator, a cooling pipe and a dropping funnel, which was installed in an oil bath. After heating and melting at 100 ° C., 4 parts of a nonionic surfactant polyoxyethylene noniphenyl ether (average oxyethylene addition mole number = 15) is added with stirring and completely dissolved. Then, 70 parts of water at 98 ° C. was gradually added with stirring, the mixture was stirred for 1 hour, and then allowed to cool to 25 ° C. with stirring. After that, stirring was stopped, and after standing for 6 hours, the precipitate was removed to obtain a release agent dispersion liquid. Further, the solid content concentration was adjusted to 30% with ion-exchanged water. The obtained release agent dispersion liquid was used as a dynamic light scattering meter DLS700 (Otsuka Electronics Co., Ltd.)
The volume average particle diameter was 0.151 μm and the number average particle diameter was 0.11 μm.

(Production Example of Inorganic Fine Particle Dispersion) 4 parts of hydrophobized silicon oxide (H2000 Hoechst) was mixed with 196 parts of methanol, and the mixture was ball-milled for 5 hours with an alumina ball of 4 mmφ.

(Evaluation) A PPC copying machine (Imagio 42) was manufactured using the developers prepared in the following Examples and Comparative Examples.
No. 0, manufactured by Ricoh) was applied to the fixing roller without applying silicone oil, and the image was evaluated by copying. (Agglomerates during embedding treatment) [Weight 22 μm non-passing material / (colored resin particles (core particles) + release agent particles)] × 100 (weight) (Transfer rate) Develop and transfer a black original document The machine was stopped in the middle of the process, and the toner on the transferred portion and the untransferred portion on the photosensitive member was transferred to an adhesive paper of known weight and constant area, and the weight of each was measured to determine the transfer rate as follows. [(Weight of untransferred portion-Weight of transferred portion) / Weight of untransferred portion] x 100 (Releasability) Full black (black solid) image is copied and the state of generation of nail marks on separated nails (length of nail marks) Was evaluated on a 5-point scale. 5 = No claw marks 4 = Claw marks less than 1 mm 3 = Claw marks 1 mm or more and less than 10 mm 2 = Claw marks 10 mm
20 mm or more 1 = Nail mark 20 mm or more (image density) The reflection density of a circular image having a diameter of 10 mm was measured with a Macbeth densitometer. (Sharpness of image) The dot image was observed with an optical microscope, and the state of the image was evaluated in five levels. 5 = Toner is present only in the dot portion and the contour is clear. 4 = Most of the toner is present in the dots, but the outline is slightly unclear. 3 = A lot of toner is present in the dot portion, but the contour is unclear. 2 = Toner scattering is large, but the presence of dots can be identified. 1 = Toner scattering is so large that the presence of dots cannot be determined. The judgment is based on the limit sample. (Fixability) After fixing with the fixing device of IMAGEO 420 (constant conditions), a black solid image was put on a drawing tester and the detached state of the image was evaluated on a five-point scale. 5 = Most of the drawn portion is not peeled off. 4 = The drawn portion is peeled off like dots. 3 = The drawn portion is peeled off in a broken line shape. 2 = All the drawn parts are peeled off, and the width of peeling is narrow. 1 = All the drawn parts were peeled off, and the width of peeling was wide. The judgment is based on the limit sample.

Example 1 30 parts of the colored resin particles (core particles) obtained in Production Example- (a) were mixed with water: methanol = 30:
The mixture was added to 270 parts by weight of 70 (by weight) of the mixed liquid, stirred and ultrasonically dispersed to obtain a colored resin particle dispersion liquid. This dispersion was placed in a four-necked flask equipped with a stirrer, a cooling tube, and a thermometer,
At room temperature, 3 parts of the release agent fine particle dispersion liquid of Production Example 1 was added, and 10 parts of a 0.4% methanol solution of stearylamine acetate was added dropwise with stirring to attach release agent fine particles to the surface of the colored resin particles. After that, it was heated in a constant temperature water bath at 50 ° C. for 5 hours. After cooling, 80 parts of water was added and the mixture was passed through a stainless steel sieve having an opening of 22μ. The non-passed material at this time was dried and weighed. After suction filtration of this passing dispersion, water: methanol = 5
Re-disperse in 100 parts of 0:50 (weight) mixture and mix at room temperature for 3
After stirring for 0 minute, suction filtration and vacuum drying were performed to obtain a toner having carnauba wax fine particles embedded in the surface thereof. When this toner was observed with a scanning electron microscope, it was found to be spherical particles having a slightly uneven surface. Also, when the cross section of the toner was dyed with rubidium oxide and observed with a transmission electron microscope, the release agent fine particles were present in contact with the inside of the circumference of the toner cross section while maintaining the shape of the particles. Was confirmed. 20 parts of this toner was mixed with 0.2 part of hydrophobic silica with a mixer, and this was mixed with 780 parts of 75 μm ferrite carrier coated with silicone resin for 10 minutes using a ball mill to prepare a developer.

Example 2 Water of Example 1: Methanol =
A toner and a developer were prepared in the same manner as in Example 1 except that 6 parts of a 10% aqueous solution of polyethylene glycol nonylphenyl ether was added to the mixed solution of 30:70 (weight).

Example 3 30 parts of the core particles obtained in Production Example- (a) was added to 216 parts of a mixed solution of water: methanol = 90: 10 (weight), and the mixture was stirred and ultrasonically dispersed to give a colored resin. A particle dispersion was obtained. This dispersion is placed in a beaker, 3 parts of the release agent fine particle dispersion of the production example is added at room temperature, and 10 parts of a 0.4% methanol solution of stearylamine acetate is dropped with stirring to release the release agent fine particles onto the surface of the colored resin particles. Attached. Then, 54 parts of acetone was added dropwise at room temperature and the mixture was stirred at a constant temperature of 28 ° C. for 5 hours. 80 parts of water was added and the mixture was passed through a 400-mesh wire net, suction filtered, and dried under reduced pressure to obtain a toner in which carnauba wax fine particles were embedded on the surface. A developer was prepared from this toner in the same manner as in Example 1 and evaluated.

[Examples 4 to 8] Each toner was obtained in the same manner as in Example 1 except that the production conditions shown in Table 1 below were used, and a developer was similarly prepared using each of the toners. (Below margin)

[Table 1] * Surfactant solution is the same as in Example 2

Comparative Example 1 30 parts of the core particles obtained in Production Example- (a) was added to 270 parts of a mixed solution of water: methanol = 90: 10 (weight), and the mixture was stirred and ultrasonically dispersed to give colored resin particles. A dispersion was obtained. This dispersion was used in the same manner as in Example 1 to obtain a toner to which the release agent particles of Production Example were attached and fixed. When the adhered state of the release agent fine particles of the toner was observed by the same method as in Example 1, the release agent fine particles were attached outside the circumference of the toner cross section while maintaining the shape of the fine particles.

[Comparative Example 2] In the same manner as in Example 1, after preparing the dispersion liquid of the core particles obtained in Production Example- (a) and adhering the release agent fine particles, The mixture was stirred in the same apparatus at 25 ° C. for 5 hours. This liquid was treated in the same manner as in Example 1 to obtain a toner. When the adhesion state of the release agent fine particles in this toner was observed by the same method as in Example 1, the release agent fine particles were in the same attached state as in Comparative Example 1.

Comparative Example 3 A release agent dispersion liquid was prepared by adding 3 parts of the release agent fine particle dispersion liquid of the production example and 6 parts of polyethylene glycol nonylphenyl ether 10% aqueous solution to 200 parts of ion-exchanged water to dilute. Production Example-
30 parts of the core particles obtained in (a) were added and ultrasonically dispersed with stirring. Stearylamine acetate of 0.
A 4% methanol solution was added to attach the release agent particles to the core particles. After that, the mixture was stirred at 30 ° C. for 2 hours and then a toner was obtained by the same operation as in the example. When the adhered state of the release agent fine particles of the toner was observed by the same method as in Example 1, the release agent fine particles were attached outside the circumference of the toner cross section while maintaining the shape of the fine particles.

The developers prepared by using the electrostatic charge developing toners obtained in Examples 1 to 8 and Comparative Examples 1 to 3 were evaluated. The results are shown in Table 2. (Below margin)

[Table 2]

Description of Evaluation Results (1) Addition of a surfactant can reduce agglomerates without changing releasability. (2) When acetone having a large swelling property for the colored resin particles is used, embedding is possible without heating, but aggregates increase and the sharpness of the image decreases. (3) In the comparative example, the generation of aggregates is small, but the transfer rate is remarkably reduced and a normal image cannot be obtained.

Example 9 15 parts of the core particles obtained in Production Example- (b) was used in an amount of 25.5 parts of ion-exchanged water and 5 parts of methanol.
In addition to 9.5 parts of the mixed liquid, 6 parts of a 5% aqueous solution of polyethylene glycol mono-nonylphenyl ether was added and stirred, and dispersed with an ultrasonic cleaner for 5 minutes to prepare a core particle dispersion liquid. The release agent fine particle dispersion liquid 1.
7 parts and 3.75 parts of the inorganic fine particle dispersion liquid of the above Production Example were added and 5 parts of a 0.4% methanol solution of stearylamine acetate was added dropwise with stirring to remove all of the release agent fine particles and a part of the inorganic fine particles as core particles. Attached to. After this, 50 in a constant temperature water bath
The release agent fine particles and the inorganic fine particles adhered were fixed by heating and stirring at 4 ° C. for 4 hours. After cooling this dispersion, 34 parts of water was added to suppress the swelling of the core particles, and then passed through a 400-mesh wire mesh (opening 20 μm). The non-passed material at this time was dried and weighed. The particles obtained by suction filtration of this passing dispersion are added to a mixed solution of 17.5 parts of water and 17.5 parts of methanol, redispersed, stirred for 30 minutes, suction filtered and dried under reduced pressure at 40 ° C. to obtain a toner. It was When this toner was observed with a scanning electron microscope, a slight amount of inorganic fine particles was found to be adhering to the spherical particles with slight irregularities, and no protrusion of release agent particles was observed. Further, when the cross section of the toner was dyed with rubidium oxide and observed with a transmission electron microscope, it was found that the release agent fine particles were present inside the circumference of the cross section of the toner in contact with the circumference while maintaining the particle shape. confirmed.

Example 10 Example 9 was repeated except that the aqueous polyethylene glycol nonylphenyl ether solution was not added when the core particle dispersion liquid obtained in Production Example- (b) was prepared.
A toner was prepared by the same method as described above.

[Example 11] The same as Example 9 except that 1.77 parts of a commercially available carnauba wax dispersion (Cerosol # 524; manufactured by Chukyo Yushi Co., Ltd.) was used in place of the carnauba wax dispersion of the above Production Example. A toner was produced by the method. In addition,
The volume average particle size of the carnauba wax fine particles in this dispersion was 0.08 μm, the solid content concentration was 30%, and the wax content in the solid content was 83.3%.

[Examples 12 to 18 and Comparative Examples 4 to 6] Each toner was prepared in the same manner as in Example 9 except that the manufacturing conditions shown in Table 3 below were used. When the inorganic fine particle dispersion is not hydrophobized, the dispersion medium is water: methanol = 1: 1.
(Weight), and when it was hydrophobized, methanol was used and the solid content concentration was set to 2% by the same method as in the production example. The aqueous surfactant solution is the same as in Example 2, and the commercially available release agent fine particle dispersion is the same as that in Example 3. The addition weight of the inorganic fine particle dispersion was changed so that the same volume was obtained. The hydrophobized titanium oxide used was a silicone treated product made by Teika, the titanium oxide used was P25 manufactured by Nippon Aerosil, the third calcium phosphate used was manufactured by Ohira Chemical Industry, and the silicon oxide used was Aerosil 200 manufactured by Nippon Aerosil. (Below margin)

[0076]

[Table 3]

Preparation of Developer To 100 parts of the toner obtained in each of Examples and Comparative Examples, 1 part of hydrophobic silica as a fluidizing agent was mixed with a mixer. 2 parts of this toner and 100μ coated with silicone resin
The ferrite carrier of m was mixed with a ball mill for 10 minutes to prepare each developer. PPC using this developer
The image was evaluated by copying with a copying machine (Imagio 420, manufactured by Ricoh) without applying silicone oil to the fixing roller. The results are shown in Table 4. (Below margin)

[0078]

[Table 4]

Description of Evaluation Results (1) The effect of preventing aggregation and fusion of toner is hydrophobic silica.
Although untreated silica is excellent, hydrophobic silica is better in transferability. (2) Aggregation and fusion of toner can be further prevented by adding a surfactant. (3) The transfer rate is improved by the release agent fine particles having a particle size of 0.1 μm or less. (4) When the amount of the hydrophobic silica added is less than 0.2 parts by weight (based on 100 parts by weight of the colored resin particles), the aggregation and fusion of the toner increases and the transfer rate also decreases. (5) When the amount of the hydrophobic silica added is more than 0.8 parts by weight (based on 100 parts by weight of the colored resin particles), aggregation and fusion of the toner can be prevented, but the transfer rate decreases. (6) When the inorganic fine particles are not added, toner cohesive fusion occurs and the transfer rate is slightly low. (7) Under the condition that the colored resin particles are not swollen, the transfer rate is significantly reduced.

[0080]

According to the production method of the present invention, the particle size distribution is small and the particle size distribution is narrow, and the fine particles of the release agent are uniformly embedded in the vicinity of the toner surface. It is possible to produce a toner for electrostatic charge development having excellent durability and capable of obtaining various images by an industrially advantageous method.

Claims (6)

[Claims] 1. A method for producing a toner for electrostatic charge development, comprising fine particles of a releasing agent fixed to the surface of core particles containing a colorant and a binder resin as main components, wherein the core particles are released in a liquid dispersion medium. A method for producing a toner for electrostatic charge development, which comprises depositing fine agent particles and then swelling the core particles to embed and fix the fine release agent particles on the surface of the core particles. 2. A method for producing a toner for electrostatic charge development, comprising releasing agent particles fixed to the surface of core particles comprising a colorant and a binder resin as main components, in a liquid for swelling the core particles,
A method for producing a toner for electrostatic charge development, characterized in that fine particles of a release agent are attached to and embedded in the core particles. 3. The method for producing a toner for electrostatic charge development according to claim 2, wherein the fixing is performed in the presence of inorganic fine particles. 4. The inorganic fine particles are hydrophobic silica,
The amount added is 0.2 with respect to 100 parts by weight of the core particles.
4. The method for producing a toner for electrostatic charge development according to claim 3, wherein the amount is from 0.8 to 0.8 parts by weight. 5. The method for producing an electrostatic charge developing toner according to claim 1, wherein heating is performed when the core particles are swollen. 6. The method for producing a toner for electrostatic charge development according to claim 1, wherein the embedding fixation is carried out in the presence of a nonionic surfactant.