JPS63195659A - Production of electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To prevent the deterioration of image density after endurance of an image displayed, and the generation of faulty cleaning by mixing a polymer toner contg. a thermoplastic resin and a coloring agent, a hydrophobic silica, and a metal salt of fatty acid with a liquid dispersing medium, and removing said liquid dispersing medium from the obtd. dispersion, thereby sticking the hydrophobic silica and the metal salt of the fatty acid to the surface of the polymer toner. CONSTITUTION:The hydrophobic silica and the metal salt of the fatty acid are stuck to the surface of the polymer toner by mixing the composite composed of the polymer toner contg. at least the thermoplastic resin and the coloring agent, the hydrophobic silica, the metal salt of the fatty acid and the liquid dispersing medium, and removing said liquid dispersing medium from the obtd. dispersion. Thus, the hydrophobic silica and the metal salt of the fatty acid are stuck on the surface of the polymer toner without injuring the characteristic property of the polymer toner and occurring the fusion of said toner. The polymer toner which does not generate the deterioration of the image density and the faulty cleaning after the endurance of the image displaied is obtd.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for depositing a fatty acid metal salt in a method for producing a toner for developing an electrostatic image.

[Prior Art] In the conventional general suspension polymerization method, a monomer composition containing at least a colorant and a polymerizable monomer is granulated to a toner particle size in an aqueous medium, and the monomer composition that has been added in advance is granulated to the size of a toner particle. A polymerizable monomer is polymerized using radicals generated when a polymerization initiator or a newly added polymerization initiator is decomposed by heat to form a polymer, thereby producing a polymerized toner. In other words, since this method does not involve a pulverization process, the polymerized toner does not need to be brittle and has a spherical shape, so it has excellent fluidity.
It has features such as uniform triboelectricity.

In recent years, in order to lower the fixing temperature and/or fixing pressure of polymerized toner in the contact roller fixing method, solid paraffin or low molecular weight polyolefin, which has shape retention properties at room temperature, has been added to the monomer composition. Polymerized toners containing a large amount of such low softening point compounds have been obtained.

In general, these polymerized toners are made by externally adding additives that modify the surface properties of the toner, such as scalability and slipperiness, to the toner and Mn that have not been subjected to the conventional pulverization process and subjected to F49 heating. It is used as a photographic developer.

This external addition method is preferable to stirring using a conventional high-shear mill, etc., in order to maintain the spherical structure of the polymerized toner and to prevent the encapsulated low softening point compound from being exposed to the surface. A method is used in which a polymerized toner is stirred and mixed with hydrophobic silica as a fluidity imparting agent and a fatty acid metal salt as a lubricant in an aqueous medium that generates little amount of .

[Problems to be Solved by the Invention] However, in the above-mentioned external addition method, only either hydrophobic silica or fatty acid metal salt is externally added, and therefore image density or cleaning defects may be affected after image printing is carried out. For example, even if a large amount of hydrophobic silica is externally added to improve the durability of image density, there is a limit to the durability of image density. There was a problem that scattering occurred, causing new problems to the image.

One object of the present invention is to solve the problems of the prior art described above.

In other words, the external addition of hydrophobic silica and fatty acid metal salts to polymerized toner can be carried out uniformly and efficiently without causing deformation or staining of the toner, thereby preventing a decrease in image density or poor cleaning even after the image has been produced for a long time. The purpose of the present invention is to provide a polymerized toner that does not cause polymerization.

[Means and effects for solving the problems] According to the present invention, a system consisting of a polymerized toner containing at least a thermoplastic resin and a colorant, hydrophobic silica, a fatty acid metal salt, and a liquid dispersion medium is mixed, There is provided a method for producing a toner for developing electrostatic images, characterized in that hydrophobic silica and a fatty acid metal salt are attached to the surface of a polymerized toner by removing a liquid dispersion medium from a dispersion system.

The polymerized toner applied to the production method of the present invention is a toner obtained by suspension polymerizing a monomer composition containing at least a polymerizable monomer and a colorant in an aqueous medium. It is approximately spherical in shape and has good fluidity and triboelectric properties. The polymerized toner obtained in this way has good affinity for water unless the aqueous medium is completely removed by drying, and the polymerized toner in such a state, hydrophobic silica, fatty acid metal salt, and liquid dispersion medium have a good affinity for water. By mixing these, hydrophobic silica and fatty acid metal salt can be attached to the surface of the polymerized toner.

The liquid dispersion medium used in the present invention is preferably an aqueous medium (containing a dispersion aid such as a surfactant as necessary) or an alcoholic aqueous medium.As for the alcohol used, for the subsequent drying, It is better to use something with a lower boiling point than water, such as ethanol or methanol.

Examples of the hydrophobic silica used in the present invention include, but are not limited to, Aerosil R972 (manufactured by Nippon Aerosil Co., Ltd.).

Moreover, the amount of these hydrophobic silicas added is 10
0.1 to 15 parts by weight, preferably 0.5 parts by weight
~10 parts by weight is good.

Examples of fatty acid metal salts used in the present invention include zinc stearate, calcium stearate, etc.
I'm going to have a good time with my own character.

These fatty acid metal salts can be used by being dispersed in the liquid dispersion medium, but it is also possible to use an emulsion of the fatty acid metal salts dispersed in an aqueous medium containing an ionic emulsifier. As such an emulsion, Cellosol 1B?
-N (zinc stearate), Serozol 644-5
0B (calcium stearate), Hydrin Z-
7-30 (zinc stearate), Hydrin E-366
(zinc stearate), Hydrin E-619 (zinc stearate) manufactured by Middle East Oil and Fat (E) and above. The amount of these fatty acid metal salts added is preferably 0.1 to 10 parts by weight, preferably 0.3 to 5 parts by weight, per 100 parts by weight of the polymerized toner.

After mixing and stirring such hydrophobic silica, fatty acid metal salt, and liquid dispersion medium with undried polymerized toner, the liquid dispersion medium is filtered and dried to adhere the hydrophobic silica and fatty acid metal salt to the surface of the polymerized toner. can be done.

Since the method of the present invention is carried out in a liquid dispersion medium, there is little shearing force on the polymerized toner and no heat is generated, so the shape and properties of the monopolymerized toner are not impaired, and the toner is It has the advantage that no fusion occurs.

Generally, toners to which a fatty acid metal salt as a lubricant is not externally added may not be able to sufficiently clean the residual toner on the photoreceptor after transfer, but the toner obtained by the present invention can be shows good cleaning properties similar to toners to which fatty acid metal salts are externally added.
Also, sufficient image density can be obtained, similar to toners to which hydrophobic silica as a fluidity imparting agent is externally added using a mill or the like.

In the present invention, in order to more uniformly adhere hydrophobic silica and fatty acid metal salt to the polymerized toner, hydrophobic silica and fatty acid metal salt are added to the dispersion medium before mixing the polymerized toner and these surface modifiers. For example, as a dispersing means, a device such as a piston-type high-pressure homogenizer manufactured by Gorlin Co., Ltd. is exemplified. This high-pressure homogenizer has a pressurizing mechanism for pressurizing the processing liquid, a valve mechanism for discharging or spouting the pressurized processing liquid, and an impact mechanism for colliding the discharged processing liquid. have,
Generally used as a homogenizer.

ArfA will be explained in more detail with reference to Figure 1 of the attached drawings, using as an example a case where a piston-type high-pressure homogenizer manufactured by Gorlin is used as a dispersion means for hydrophobic silica and fatty acid metal salt. . After pre-dispersing hydrophobic silica and fatty acid metal salts in a liquid dispersion medium using a high shear force stirrer such as a homomixer, this dispersion 1 was mixed with 10 kg/kg using a pressurizing means.
It is pressurized to a predetermined pressure of ca+2 or higher and supplied to the high pressure section 2. In the above-mentioned homogenizer, a positive displacement plunger pump is used as a pressurizing means because it is highly quantitative and the pressure can be adjusted arbitrarily. The pressurized dispersion liquid l is directed from the gap 5 between the valve seat 3 and the valve 4, which constitute the valve mechanism, to the impact ring 6, which is a collision member, at the high pressure section 2.
It is discharged at a high speed due to the pressure difference between the pressure part 7 and the low pressure part 7, and collides with the surface of the impact ring 6. As a result, the aggregates of the hydrophobic silica and the fatty acid metal salt, which were aggregated and coarse, are made into fine particles and uniformly dispersed in the liquid dispersion medium. Moreover, repeating the pressurized dispersion step continuously or intermittently (usually about 2 to 3 times) is effective in reducing aggregates of hydrophobic silica and fatty acid metal salt.

In order to disperse the dispersion prepared in the preliminary dispersion step by discharging it from a gap or a nozzle to a low pressure part, the dispersion is heated at 10K.
Pressure is applied to g/cm2 or more. If it is less than 10 kg/cm2, the pressure difference between the high pressure part and the low pressure part is small, so the speed at which the dispersion liquid is discharged is insufficient, and it is difficult to obtain efficient dispersion of hydrophobic silica and fatty acid metal salt. Preferably the dispersion is io
o~700Kg/C■2, especially about 300~650Kg/
When pressurized to c+s2, the pressure difference between the high pressure part and the low pressure part is about 100 Kg/c layer 2 or more (more preferably about 300 Kg/c layer 2 or more)
~650Kg/c+s2) The resulting dispersion is discharged at high speed and collides with the collision member. Aggregates in the dispersion liquid discharged at high speed are well pulverized.

Examples of polymerizable monomers applicable to the polymerized toner used in the present invention include styrene, 0-methylstyrene, di-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, and p-chlorostyrene. , 3.
4-dichlorostyrene, p-ethylstyrene, 2,4-
Dimethylstyrene, p-n-butylstyrene, p-
Styrene and its derivatives such as tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene; ethylene, propylene Ethylenically unsaturated monoolefins such as , butylene, and isobutylene; Vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, and vinyl fluoride; Vinyl esters such as vinyl acetate, vinyl propionate, and vinyl benzoate; Methacryl Methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, m-2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, methacrylic acid α-methylene aliphatic monocarboxylic acid esters such as dimethylaminoethyl and diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate, inbutyl acrylate, propyl acrylate, n-octyl acrylate , acrylic esters such as dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, and phenyl acrylate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether: vinyl Vinyl ketones such as methyl ketone, vinylhexyl ketone, methyl isopropenyl ketone: N-vinylpyrrole, N-vinylcarbazole, N-vinylindole,
Examples include N-vinyl compounds such as N-vinylpyrrolidone; vinylnaphthalenes; vinyl monomers such as acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylaterile, and acrylamide. These monomers may be used alone or in combination of two or more, and a polymer of these polymerizable monomers may be added to the monomer composition. Among the above monomers, styrene or alkyl basic i
Styrene having a substituent or a combination of styrene and another monomer is preferred in consideration of the developability and durability of the polymerized toner.

In addition, charge control agents, various coloring agents, and fluidity modifiers may be added to the monomer composition as necessary.Charge control agents include metal-containing dyes, nigrosine, etc. Coloring agents include conventionally known dyes, carbon black,
Pigments such as grafted carbon black, in which the surface of carbon black is coated with a resin, and magnetic powders of ferromagnetic metals such as iron, cobalt, and nickel, and alloys and compounds such as magnetite, hematite, and ferrite can be used. Also,#! For purposes of controlling the amount, fillers such as calcium carbonate and finely divided silica may be incorporated into the toner in an amount of 0.5 to 20% by weight. Further, in order to prevent toner particles from coagulating with each other and improve fluidity, a fluidity improver such as fine Teflon powder may be added.

In the present invention, a polymerizable monomer system to which a polymer, copolymer or cyclized rubber having a polar group is added during polymerization is suspended in an aqueous phase in which a dispersant having an opposite charge to the polar polymer is dispersed. It is preferable to make it cloudy and polymerize it. That is, the cationic or anionic polymer, copolymer or cyclized rubber contained in the polymerizable monomer system is polymerized with the oppositely charged anionic or cationic dispersant dispersed in the aqueous phase. The particles that become the toner inside are electrostatically attracted to each other on the surface, and the dispersant covers the particle surface to prevent the particles from coalescing.
Stabilize it.

Examples of polar polymers (including polar polymers) and counterloading dispersants that can be used in the present invention are shown below.

(a) Examples of cationic polymers include polymers of nitrogen-containing monomers such as dimethylaminoethyl methacrylate and diethylaminoethyl acrylate, or copolymers of nitrogen-containing monomers with styrene, unsaturated carboxylic acid esters, etc. .

(b) Examples of anionic polymers include nitrile monomers such as acrylonitrile, halogen-containing monomers such as vinyl chloride, unsaturated carboxylic acids such as acrylic acid, unsaturated dibasic acids, and unsaturated dibasic acids. Anhydrous.

There are polymers of nitro monomers.

CC) As anionic dispersants, water-soluble polymers such as partially saponified vinyl acetate polymers, Aerosil-
There are colloidal silicas such as 200 and 1300 (manufactured by Nippon Aerosil Co., Ltd.).

(d) Examples of the cationic dispersant include aluminum oxide, water-degrading magnesium, and fine wood-philic positively chargeable silica powder such as aminoalkyl-modified colloidal silica. Cyclized rubber may be used instead of the polar polymer.

Furthermore, for the purpose of lowering the fixing temperature and/or fixing pressure of the polymerized toner, a low softening point compound such as solid paraffin or low molecular weight polyolefin that has shape retention properties at room temperature is added to the monomer composition. The low softening point compound in the present invention may be added in a large amount by the ring and ball method (JIS
Softening point measured by K 2531 etc.) is 40-13
0°C, preferably 50 to 120°C. If the softening point is 40° C. or lower, the blocking resistance and shape retention of the toner will be insufficient, and if the softening point is 130° C. or higher, there will be little effect in lowering the fixing temperature and fixing pressure.

Examples of low softening point compounds include paraffins, waxes, low molecular weight polyolefins with softening points within the above range, modified waxes having aromatic groups, hydrocarbon compounds having alicyclic groups, natural waxes, and long chains with 12 or more carbon atoms. Hydrocarbon chain [
Examples include long-chain carboxylic acids having an aliphatic carbon chain of CH3 (CH2) or (CH2) or more, and esters thereof. A mixture of different low softening point compounds may be used. Specifically, paraffin wax (manufactured by Nippon Oil)
, paraffin wax (manufactured by Nippon Seiro), micro wax (manufactured by Nippon Oil), microcrystalline wax (manufactured by Nippon Seiro), hard paraffin wax (manufactured by Nippon Seiro)
, PH-130 (manufactured by Hoechst), Mitsui Hiwax l
l0P (Mitsui Petrochemical), Mitsui Hiwax 220P
(manufactured by Mitsui Petrochemical), Mitsui Hiwax 660P (
Mitsui Hiwax 210P (Mitsui Petrochemical), Mitsui Hiwax 320P (Mitsui Petrochemical), Mitsui Hiwax 410P (Mitsui Petrochemical), Mitsui Hiwax 420P (Mitsui Petrochemical)
, Hilets T-100X (Mitsui Petrochemicals), Hilets T-200X (Mitsui Petrochemicals), Hilets? -300X (Mitsui Petrochemical): Vetrogin 80
(Mitsui Petrochemicals), Vetrogin 100 (Mitsui Petrochemicals), Vetrogin 120 (Mitsui Petrochemicals), Tacace A-100 (Mitsui Petrochemicals f!A), Tacace F-100 (Mitsui Petrochemicals) , Tuck Ace B-
60 (Mitsui Petrochemical), modified wax JC-114
1 (Mitsui Petrochemical), modified wax JC-2130 (
Mitsui Petrochemicals), modified wax JC-4020 (Mitsui Petrochemicals), modified wax JC-1142 (Mitsui Petrochemicals), modified wax JC-5020 (Mitsui Petrochemicals): beeswax, carnauba wax, montan wax etc. can be mentioned. In addition, when using a low softening point compound having a softening point of 100° C. or higher, it may be preferable to carry out dispersion and granulation under pressure while raising the temperature of the aqueous medium to 100° C. or higher.

The above-mentioned low softening point compound controls the fixing temperature of the polymerized toner and/or
Alternatively, in order to lower the fixing pressure, 50 to 3,000 parts by weight are mixed with 100 parts by weight of the polymerizable monomer. It is particularly preferable that 70 to 1,000 parts by weight of the 50
If it is less than 3,000 parts by weight, it is insufficient to lower the fixing temperature or fixing pressure of the fixing roller, and if it exceeds 3,000 parts by weight, blocking resistance and durability tend to decrease.

When a large amount of a low softening point compound is contained, the polar polymer added to the above-mentioned polymerizable monomer collects on the surface layer of the toner particles, forming a kind of shell-like form, and the resulting particles become pseudo-like. It becomes a capsule. A relatively high molecular weight polar polymer, copolymer, or cyclized rubber encapsulates a large amount of low softening point compounds inside the toner particles, giving the toner particles excellent blocking resistance, developability, and abrasion resistance. At the same time, it is possible to obtain a toner that also provides excellent fixing properties and satisfies these contradictory requirements. In addition, especially to the polymerized toner obtained in this way, adding hydrophobic silica or fatty acid metal salt externally using a strong shearing force using a coffee grinder or the like as in the past does not create a pseudo capsule structure. As a result, the above-mentioned excellent properties are lost, resulting in adverse effects such as deterioration of anti-blocking properties. Therefore, for such polymerized toners, the external addition method of the present invention, which requires less shearing force and does not generate heat, is extremely effective.

Furthermore, in the present invention, since both hydrophobic silica as a fluidity imparting agent and fatty acid metal salt as a lubricant are externally added, image density and cleaning properties are improved compared to the conventional case where only one was added externally. It is characterized by improved durability. Although the reason for this is unclear, it is probably due to the synergistic effect of hydrophobic silica and fatty acid metal salt.

Further, there is an effect that other problems such as toner scattering and poor toner coating on the sleeve that occur when only a large amount of hydrophobic silica is added externally to improve durability do not occur.

Furthermore, the polymerization initiator used in the present invention is soluble in the polymerizable monomer, and is used in the amount range normally used (2 to 5 parts by weight of the polymerization initiator per 100 parts by weight of the monomer). 0 Examples of polymerization initiators that can be used in the present invention include 2,2'-7
Zobisu(2,4-dimethylvaleronitrile), 2
．． 2'-Azobisisobutyronitrile, 1.1'-Azobis(cyclohegyushun!-carbonitrile), 2
．． 2'-7zobis-4-methoxy-2,4-dimethylvaleronitrile, other azobisin butyronitrile (
azo or diazo polymerization initiators such as benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorylbenzoyl peroxide, lauroyl peroxide; Examples include oxide polymerization initiators. Also, two or more of these may be used in combination.

Hang'l! The tetrapolymerization reaction is usually carried out at a polymerization temperature of 50° C. or higher, and the upper limit temperature is set in consideration of the decomposition rate of the polymerization initiator. If the set polymerization temperature is too high, the polymerization initiator will be rapidly decomposed, which is not preferable. Therefore, when the softening point temperature of the low softening point compound used is high (usually 70°C or higher), granulation at a temperature suitable for polymerization cannot be carried out because the viscosity of the monomer composition increases, so an aqueous dispersion medium cannot be used. After first granulating the monomer composition without adding a polymerization initiator while maintaining the temperature above this softening point, the temperature of the dispersion system is lowered to a temperature range below the upper limit temperature suitable for polymerization. After that,
Special techniques are required to add the polymerization initiator into the aqueous medium.

In the suspension method, a monomer composition in which a polymerizable monomer, additives, etc. are uniformly dissolved or dispersed in a colorant dispersed in a low softening point compound is mixed into a monomer composition of 0.1 to 50% by weight. % of a dispersant (e.g. a poorly soluble inorganic dispersant) (
For example, the mixture is heated to a temperature higher than the polymerization temperature by 5° C. or more, preferably 10° C. or more higher than the polymerization temperature) using a conventional stirrer, homomixer, homogenizer, or the like. Preferably the monomer droplets are of the desired toner particle size.

Generally 30 JLm or less (e.g. volume average particle size 0.1-2
The stirring speed, time, and temperature of the aqueous medium are adjusted to have a size of 0IL■). Thereafter, the temperature of the aqueous medium is lowered to the polymerization temperature while stirring is carried out to the extent that sedimentation of the particles is prevented so that this state is substantially maintained by the action of the dispersant. Polymerization temperature is 50°C or higher, preferably 55°C
The temperature is set to 80 DEG C., preferably 60 DEG to 75 DEG C., and a substantially water-insoluble polymerization initiator is added while stirring to carry out polymerization.

After the reaction is completed, the produced toner particles are recovered by an appropriate method such as washing, filtration, decantation, centrifugation, etc. and dried to obtain a polymerized toner. In the suspension polymerization method, 200 parts by weight of water is usually used per 100 parts by weight of polymerizable monomer.
~3000 parts by weight are used as aqueous dispersion medium.

Also suitable stabilizers, such as polyvinyl alcohol,
Gelatin, methylcellulose, methylhydropropylcellulose, ethylcellulose, sodium salt of carboxymethylcellulose, polyacrylic acid and their salts, starch, gum alginate, zein, casein,
One or a mixture of tricalcium phosphate, talc, barium sulfate, bentonite, aluminum hydroxide, ferric hydroxide, titanium hydroxide, thorium hydroxide, etc., to an extent that does not adversely affect the production method of the present invention. It may also be used in an aqueous medium.

Furthermore, in order to uniformly disperse the inorganic dispersant, a surfactant may be used to the extent that it does not adversely affect the production method of the present invention, and this is because it promotes the intended action of the dispersant. Specific examples include sodium dodecylbenzenesulfonate, sodium tetradecylsulfate, sodium pentadecylsulfate, sodium octylsulfate, sodium allyl-alkyl-polyethersulfonate, sodium oleate, sodium laurate, and sodium caprate. , sodium caprylate, sodium caproate, potassium stearate, calcium oleate, 3,3-disulfonodiphenylurea-4
, 4-diazo-bis-amino-8-naphthol-6-sulfonate sodium, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5.5-tetramethyl-triphenylmethane-4,4-diazo- Examples include sodium bis-β-naphthol-disulfonate and others.

Monomers that are easily soluble in water simultaneously cause emulsion polymerization in water, and the resulting suspension polymer is contaminated with small emulsion polymer particles, so water-soluble polymerization inhibitors, such as metal salts, are added to emulsify in the aqueous phase. It is also possible to add glycerin, glycol, etc. to the water to prevent polymerization, and to increase the viscosity of the aqueous medium and prevent coalescence of particles during polymerization. In addition, Na
It is also possible to add salts such as CR+KCR, Na25Oa or Brønsted acids such as salts to the aqueous medium to increase the ionicity of the polar groups.

The polymerized toner obtained by the production method of the present invention can be applied to known electrostatic image development methods. , one-component development methods using magnetic toner, such as insulating-component development methods and jumping development methods;
Powder cloud method and fur brush method: Non-magnetic component development method in which the toner is held on a toner carrier by electrostatic force and transported to the developing section for development; Transported to the developing section and developed using the electric field curtain method It can be applied to electric field curtain development, etc.

[Example] Hereinafter, the present invention will be described in detail based on Examples.

Example 1 The above was heated at 60°C, 100 r, p, m using a paddle stirring blade.
After mixing for 5 minutes with
(manufactured by Mitsui Miike) for 4 hours. Next, add 2.2 to this solution.
'-Azobis-(2,4-dimethylvaleronitrile)
8g, 2.2'-7zobisisobutyronitrile 4g
is dissolved at a temperature of 60°C. This monomer composition is
Amine-modified silica (100 parts by weight of AEROSIL 200 manufactured by Nippon Aerosil ■ reacted with 5 parts by weight of aminopropyltriethoxysilane) 108 and distilled water 6
A mixture of 0.0g and 12.5g of 0.1N salt was added to a stainless steel container with a capacity of 2M, and the
1 using a TK homomixer (manufactured by Tokushu Kika Kogyo) at 0°C.
Dispersion granulation was performed by stirring for 1 hour at 0.00 Or, P, m. The dispersion thus obtained was mixed and heated at 60°C for 10 hours at 10 Or, p, +s using a paddle stirring blade.
The polymerization was completed by heating and stirring, and after washing, the aqueous dispersion medium was filtered (the toner was wet with water).

The number average particle size of this polymerized toner was 6ILrx.

After mixing one at room temperature, 2000g of water was added to this, and T
, to 100 (+Or, p, I1
．． The mixture was stirred for 30 minutes and dispersed.

This dispersion liquid and the previously obtained polymerized toner were mixed, and then heated at 10,000 rpm using a homo mixer.
, p, m for 30 minutes to adhere hydrophobic silica and zinc stearate to the surface of the polymerized toner.
After filtering and drying the dispersed particles, use a classifier (West German HEYMA)
Fine particles such as fine toner, excess hydrophobic silica, zinc stearate, and unreacted materials were removed using Albine 180 MZR manufactured by IV Company.

A developer was prepared by mixing 10 parts by weight of the obtained toner and 90 parts by weight of carrier particles having an average particle size of 40 JJ and 11 made of triiron tetroxide and epoxy resin, and development was performed under the following conditions. .

The developing device shown in FIG. 2 was used. Image carrier 1
has a selenium photoreceptor, the peripheral speed of the photoreceptor is 100 m/sec, and the highest potential of the electrostatic image formed on the image carrier 8 is +75
0v, the outer diameter of the sleeve 9 is 20+ui, its peripheral speed is 100 m/sec, the magnetic flux density in the vertical direction of the sleeve surface of the N and S poles of the magnet is 1000 Gauss, and the thickness of the developer layer is 2.
00 JLta, gap 3 between sleeve 9 and image carrier 8
00 ILta, and the bias voltage applied to the sleeve was 1400 V pp, with a DC voltage component of +200 V and an AC voltage component of 3.0 KHz. The electrostatic charge latent image was developed well, and the developed toner image was electrostatically transferred to sweat paper and fixed at 180°C.

Table 1 shows the image density and cleaning characteristics at the initial stage and after 2000 sheets of image printing.

Example 2 The above components were mixed in an attritor for 4 hours, and this mixture 1
54 g kept at 75°C was mixed with 100 g of paraffin wax 155"F melted at the same temperature and stirred to prepare a monomer composition. The obtained monomer composition was
10 g of amine-modified silica (100 parts by weight of Aerosil 200 treated with 5 parts by weight of aminopropyltriethoxysilane) and 0.5 g of amine-modified silica (100 parts by weight of Aerosil 200 treated with 5 parts by weight of aminopropyltriethoxysilane); into an aqueous medium of 1200 g of distilled water heated to 75°C containing 12.5 g of IN hydrochloric acid,
Add it to the homomixer while stirring, and leave it for 15 minutes after adding it.
The mixture was dispersed and granulated by stirring at 0000 r, p, m. After granulation, the liquid temperature was lowered to 65°C, and 4 g of 2.2'-azobis-(2,4-dimethylvaleronitrile) and 2 g of 2.2'-azobisisobutyronitrile were added to the aqueous medium as polymerization initiators. The mixture was stirred for an additional 30 minutes. Furthermore, the stirring was changed to paddle blade stirring, and the mixture was stirred at 60°C for 10 hours to complete the polymerization.

Washing of Polymerized Toner 1 Filtration of the dispersion medium and mixing of the dispersion liquid of hydrophobic silica and zinc stearate were carried out in the same manner as in Example 1. The number average particle size of the obtained polymerized toner was 6 mm.
Met. An image was formed in the same manner as in Example 1 and fixed using a hot pressure roll at 130°C and a pressure of 20 kg/cs2. The evaluation results are shown in Table 1.

Comparative Example 1.2 The same procedure as in Example 1 was carried out except that either hydrophobic silica or zinc stearate was not mixed.

Comparative Examples 3 and 4 The same procedure as in Example 2 was carried out except that either hydrophobic silica or zinc stearate was not mixed.

Example 3 Hydrophobic silica and zinc stearate were attached to the filtered polymerized toner obtained in Example 1 as follows.

After mixing at room temperature, 700g of water was added to this, and T,
3 at 10,000 r, p, m using a homomixer.
After preliminary dispersion for a minute, the dispersion was circulated twice using a piston-type high-pressure homogenizer (manufactured by Gorlin, model 15-87A) at a discharge pressure of 580 kg/cs2 to combine hydrophobic silica and stearic acid. Zinc was evenly dispersed (
(3 minutes required). This dispersion liquid and the previously obtained filtered polymerized toner were mixed, and mixed and stirred for 30 minutes at 10,000 r, p, m using a homomixer to form a hydrophobic surface on the surface of the polymerized toner. The evaluation of zero image output with silica and fatty acid metal salt attached was carried out in the same manner as in Example 1.

Example 4 A toner was obtained by attaching hydrophobic silica and a fatty acid metal salt to the filtered polymerized toner obtained in Example 2 in the same manner as in Example 3, and image quality was evaluated in the same manner as in Example 2. I went to

Comparative Examples 5 and 6 The same procedure as in Example 3 was carried out except that either hydrophobic silica or zinc stearate was not mixed.

Comparative Example 7.8 The same procedure as in Example 4 was carried out except that either hydrophobic silica or zinc stearate was not mixed in Example 4.

[Effects of the Invention] As described above, according to the present invention, hydrophobic silica and fatty acid metal salt can be attached to the toner surface without impairing the properties of the polymerized toner or causing fusion, and image quality is improved. However, even after durability, a polymerized toner that does not cause a decrease in image density or poor cleaning can be obtained.

[Brief explanation of the drawing]

FIG. 1 is a cross-sectional view schematically showing a homogenizer that can be used in the dispersion process according to the present invention, and FIG. FIG. 2 is a diagram schematically showing a developing device used in FIG. 2...Preliminary dispersion (high pressure part) 301. Valve seat, 4... Valve, 5... Micro gap, 6... Impact ring, 7... Homogeneous atomized material (low pressure part), 8... Photosensitive drum, 9... Sleeve, 10. ... Magnet roller, 11... Developer, 12.13... Development bias power supply, 17... Doctor blade.

Claims (2)

[Claims] (1) By mixing a system consisting of a polymerized toner containing at least a thermoplastic resin and a colorant, hydrophobic silica, a fatty acid metal salt, and a liquid dispersion medium, and removing the liquid dispersion medium from this dispersion system, hydrophobic silica 1. A method for producing a toner for developing an electrostatic image, characterized by adhering a fatty acid metal salt and a fatty acid metal salt to the surface of a polymerized toner. (2) A patent claim using a polymerized toner obtained by polymerizing a monomer composition containing 50 to 3,000 parts by weight of a low softening point compound having a softening point of 40 to 130°C based on 100 parts by weight of the polymerizable monomer. A method for producing a toner for developing an electrostatic image according to item 1.