JPS63195660A - Production of electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To prevent the generation of faulty cleaning of a polymer toner by mixing the polymer toner contg. a thermoplastic resin and a coloring agent, and a metal salt of fatty acid with a liquid dispersing medium, and removing the liquid dispersing medium from the obtd. dispersion, thereby sticking the metal salt of the fatty acid to the surface of the polymer toner. CONSTITUTION:The metal salt of the fatty acid is 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 metal salt of the fatty acid and the liquid dispersing medium, and removing the liquid dispersing medium from the obtd. dispersion. As the metal salt of the fatty acid is stuck to the surface of the toner in such state that any shearing stress and heat do not generate, the characteristic performance of the toner are not injured. As the good blocking property of the toner is held and the loading of a doctor blade due to a fused material does not generate, a while line does not generate in the image formed on a transfer paper.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for producing a toner for developing an electrostatic image, and particularly to a method for attaching a fatty acid metal salt to the surface of a polymerized toner.

[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 a zero characteristic of uniform triboelectrification.

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 used as electrophotographic developers after a fatty acid metal salt is externally added as a lubricant using a high-shear mill or the like, similar to toners manufactured by conventional pulverization processes. There is.

[Problems that 95 Ming attempts to solve] However, in the external addition process as described above, strong shearing force and heat are applied to the polymerized toner, which causes changes in the shape of the polymerized toner and changes its fluidity and charging characteristics. There is also a problem that the low softening point compound contained therein comes out to the surface and the toner is fused.

The present invention aims to solve the problems of the prior art described above.

That is, it is an object of the present invention to provide a polymerized toner in which a fatty acid metal salt is externally added to a polymerized toner uniformly and efficiently without causing deformation or fusion of the toner, and in which cleaning failure does not occur.

[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, a fatty acid metal salt, and a liquid dispersion medium is mixed, and a liquid dispersion is obtained from this dispersion. A method for producing a toner for developing an electrostatic image is provided, which is characterized in that a fatty acid metal salt is attached to the surface of a polymerized toner by removing a dispersion medium.

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 thus obtained is:

Unless the aqueous medium is completely removed by drying, the affinity for water is good, and by mixing the polymerized toner in such a state with the fatty acid metal salt and the liquid dispersion medium, the fatty acid metal salt can be transferred to the surface of the polymerized toner. It can be attached.

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 fatty acid metal salts used in the present invention include, but are not limited to, zinc stearate, calcium stearate, and the like. 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. Such emulsions include Cellozol 187-N (zinc stearate), Cellozol 644-50B (calcium stearate), Hydrin Z-7-30 (zinc stearate), Hydrin E-366 (zinc stearate), Hydrin E- 619 (zinc stearate) [manufactured by Middle East Oil & Fats] and the like. The amount of these fatty acid metal salts added is 0.1 to 1 to 100 parts by weight of the polymerized toner.
0 parts by weight, preferably 0.3 to 5 parts by weight.

The fatty acid metal salt and the liquid dispersion medium are mixed and stirred with the undried polymerized toner, and then the liquid dispersion medium is filtered and dried, thereby allowing the fatty acid metal salt to adhere to the surface of the polymerized toner.

Since the method of the present invention is carried out in a liquid dispersion medium, there is little shearing force on the monopolymerized toner and no heat is generated, so the shape and properties of the polymerized 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 It exhibits good cleaning properties similar to toners to which fatty acid metal salts are externally added by milling or the like.

In the present invention, in order to more uniformly adhere the fatty acid metal salt to the polymerized toner, it is preferable to disperse the fatty acid metal salt in a dispersion medium before mixing the polymerized toner and the fatty acid metal salt. For example, as the dispersion means, a device such as a piston-type high-pressure homogenizer manufactured by Gorlin 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. - It is commonly used as a homogenizer.

The present invention will be described in more detail with reference to FIG. 1 of the accompanying drawings, taking as an example a case where a piston-type high-pressure homogenizer manufactured by Gorlin is used as a means for dispersing fatty acid metal salts. After preliminarily dispersing the fatty acid metal salt in a liquid dispersion medium using a high shear force stirrer such as a homomixer, this dispersion liquid is pressurized to a predetermined pressure of 10 kg/cm2 or more using a pressurizing means to form a high pressure ff12. supply to. 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 applied to a valve seat 3 that constitutes a valve mechanism.
It is discharged at high speed from the gap 5 between the valve 4 and the impact ring 6 as a collision member due to the pressure difference between the high pressure section 2 and the low pressure section 7, and collides with the surface of the impact ring 6. As a result, the aggregates of the fatty acid metal salt that were aggregated and coarse are made into fine particles and uniformly dispersed in the liquid dispersion medium. Also,
Repeating this pressurized dispersion process by circulating it continuously or intermittently (usually about 2 to 3 times) is effective in reducing aggregates of fatty acid metal salts.

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 is discharged is insufficient, and it is difficult to obtain efficient dispersion of the fatty acid metal salt. Preferably, the dispersion is 100 to 700 K.
g/cm2, especially when pressurized to about 300 to 650 Kg/cm2, the pressure difference between the high pressure part and the low pressure part is about 100 Kg.
/cs+2 or more (more preferably about 300-650K
g/c 2), so the dispersion liquid 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, layer-methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, and p-chlorostyrene. ,3,
4-dichlorostyrene, p-ethylstyrene, 2,4-
Dimethylstyrene, p-n-butylstyrene, p-t
ert-butylstyrene, p-n-hexylstyrene,
p-n-octylstyrene, p-n-nonylstyrene,
Styrene and its derivatives such as p-n-decylstyrene and p-n-dodecylstyrene; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and isobutylene; vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride Vinyl halides such as vinyl acetate, vinyl propionate, vinyl benzoate; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, methacrylic fll-n -α-methylene aliphatic mo/carboxylic acid esters such as octyl, dodecyl methacrylate, -2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, methyl diacrylate, acrylic Ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, acrylic W#-2-chloroethyl, acrylic acid Acrylic acid esters such as phenyl; vinyl methyl ether.

Vinyl ethers such as vinyl ethyl ether and vinyl isobutyl ether; Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone; - Vinyl compounds; Vinylnaphthalenes: Vinyl monomers such as acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylic acid derivatives, and acrylamide. These may be used alone or in combination of two or more, and polymers of these polymerizable materials may be added to the monomer composition. Among the above-mentioned intermediates, styrene or styrene having a substituent such as an alkyl group, or a combination of styrene and other monomers is preferred in consideration of the developability and durability of the polymerized toner.

Further, a charge control agent, various coloring agents, and fluidity modifiers may be added to the monomer composition as necessary. Charge control agents include metal-containing dyes, nigrosine, etc.; colorants include conventionally known dyes, carbon black, pigments such as grafted carbon black in which the surface of carbon black is coated with resin, iron, Ferromagnetic metals such as cobalt and nickel, or magnetite, hematite,
Magnetic powders of alloys and compounds such as ferrite can be used. In addition, fillers such as calcium carbonate and finely divided silica may be added to the toner in an amount of 0.5 to 20% by weight for the purpose of increasing the amount.Furthermore, it prevents mutual aggregation of toner particles and improves fluidity. For this purpose, 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. There are anhydride and nitro monomer polymers.

(C) As the anionic dispersant, water-soluble polymers such as partially saponified vinyl acetate polymers or 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, magnesium hydroxide, 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 (C:H2) or more, and esters thereof. A mixture of different low softening point compounds may be used. Specifically, paraffin wax (Nippon Oil type), halaffin wax (Nippon Oil type), micro wax (Nippon Oil type), microcrystalline wax (
Hard paraffin wax (manufactured by Nippon Seiro), hard paraffin wax (manufactured by Nippon Seiro)
, PE-130 (manufactured by Hoechst), Tamai Hiwax ll0P (manufactured by Mikata Petrochemical), Mitsui Hiwax 220
P (manufactured by Mikata Petrochemical), Mitsui Hiwax 660P
(manufactured by Mikata Petrochemical), Mitsui Hiwax 210P (manufactured by Mikata Petrochemical), Mikata Hiwax 320P (manufactured by Mikata Petrochemical), Mikata Hiwax 410P (manufactured by Mikata Petrochemical), Mikata Hiwax 420P (manufactured by Mikata Petrochemical)
, Hiretsu T-100X (Mikata Petrochemicals), Hiretsu T-200X (Mikata Petrochemicals), Hirets T-300X (Mikata Petrochemicals): Vetrogin 80 (
Mikata Petrochemical), Vetrogin 100 (Mikata Petrochemical), Vetrogin 120 (Mikata Petrochemical), Tac Ace A-100 (Mikata Petrochemical), Tac Ace F
-100 (Mikata Petrochemical), Tac Ace B-60 (
(manufactured by Mikata Petrochemical), modified wax JC-1141 (manufactured by Mikata Petrochemical), modified wax JC-2130 (manufactured by Mikata Petrochemical), modified wax JC-4020 (manufactured by Mikata Petrochemical), modified wax JC- 1142 (manufactured by Mikata Petrochemical)
, modified wax JC-5020 (Mikata Petrochemical 'II)
:'IE wax, 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
Or polymerizable to reduce fusing pressure? ti-mer 10
50 to 3,000 parts by weight are mixed with 0 parts by weight.

In particular, it is preferable to mix 70 to 1,000 parts by weight.

If it is less than 50 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, there is a strong tendency for blocking resistance and durability 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 fatty acid metal salt externally using a strong shearing force using a coffee grinder or the like as in the past may destroy the pseudo capsule structure. As a result, the above-mentioned excellent properties are lost, resulting in negative 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, 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(cyclohexane-1-carbonitrile), 2
．． 2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, other azobisisobutyronitriles (
Azo or diazo polymerization initiators such as AIBN); peroxides such as benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxy carbonate, cumene hydroperoxide, 2,4-dichlorylbenzoyl peroxide, and lauroyl peroxide. Examples include polymerization initiators. Also, two or more of these may be used in combination.

The suspension polymerization 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 undesirable. Therefore, the softening point temperature of the low softening point compound used is high (usually 70°C or higher).
In some cases, granulation at a temperature suitable for polymerization cannot be carried out due to the increased viscosity of the monomer composition, so the temperature of the aqueous dispersion medium is kept above this softening point, and granulation is carried out at a temperature suitable for polymerization. After initially granulating the polymer composition, the temperature of the dispersion is lowered to a temperature range below the upper temperature limit suitable for polymerization, and then
Special techniques are required to add the polymerization initiator into the aqueous medium.

The suspension method involves simply dissolving or dispersing a polymerizable monomer, additives, etc. in a colorant dispersed in a low softening point compound, and adding 0.1 to 50% by weight of the composition. an aqueous medium containing 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 have a size of the desired toner particles, generally less than 30 gm (e.g., a volume average particle size of 0.1 to 20 JL).
) The stirring speed, time, and temperature of the aqueous medium are adjusted so that the size of the aqueous medium is obtained. 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 55-80°C
The temperature is particularly preferably set at 60 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 collected 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 of water is usually added to 100 parts of polymerizable monomer.
~3000 parts by weight is used as an aqueous dispersant.

Also suitable stabilizers, such as polyvinyl alcohol,
Gelatin, methyl cellulose, methyl bitro a-pill cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, 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.

Further, for uniform dispersion of the inorganic dispersant, a surfactant may be used to the extent that it does not adversely affect the production method of the present invention. This is to promote the intended action of the above-mentioned dispersants, and specific examples thereof include sodium dodecylbenzenesulfonate, sodium tetradecylsulfate, sodium pentadecylsulfate, sodium octylsulfate, and allyl-alkyl-polyethersulfone. sodium acid, sodium oleate, sodium laurate, 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.

In addition, water-soluble polymers simultaneously cause emulsion polymerization in water and contaminate the resulting suspension polymer with small emulsion polymer particles, so water-soluble polymerization inhibitors such as metal salts are added to the water phase. It is also possible to add glycerin, glycol, etc. to water in order to increase the viscosity of the aqueous medium and prevent coalescence of particles during polymerization. In addition, NaC
It is also possible to add Brønsted acids such as hydrochloric acid to the aqueous medium to increase the ionicity of salts or polar groups such as R+KCR, Na25On.

The polymerized toner obtained by the production method of the present invention can be applied to known electrostatic image development methods, such as two-component development methods such as cascade method, magnetic brush method, and microtoning method;
One-component development methods using magnetic toner, such as conductive component development method, insulating component development method, and jumping development method; Powder cloud method and fur brush method; Holding on toner carrier by electrostatic force It can be applied to a non-magnetic component development method in which the component is transported to a developing section and developed by an electric field curtain method; an electric field curtain development method in which the component is transported to a developing section and developed by an electric field curtain method.

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

Example 1 The above was carried out at 60°C, 1100r, p, using a paddle stirring blade.
After mixing for 5 minutes, add an attritor (MA-Is).
The mixture was stirred for 4 hours using a screwdriver (manufactured by Mikata Miike). Next, add 2
．． 8 g of 2'-azobis-(2,4-dimethylvaleronitrile) and 4 g of 2,2'-azobisinbutyronitrile are dissolved at a temperature of 60°C. This monomer composition was mixed with 10 g of amine-modified silica (100 parts by weight of AEROSIL 200 manufactured by Nippon Aerosil ■ and 5 parts by weight of aminopropyltriethoxysilane), 600 g of distilled water, and 0.0 g of distilled water. Add to a stainless steel container with a capacity of 2 fL containing a mixture with 12.5 g of IN hydrochloric acid, and mix it with a homomixer (Tokushu Kika Kogyo type) at 60'C in a nitrogen gas atmosphere.
The mixture was stirred for 1 hour at 10.00 Or, p, m, and Te to perform dispersion granulation. The dispersion thus obtained was mixed and stirred with a paddle stirring blade at 100r, p, l for 10 hours at 60°C to complete the polymerization, and after washing,
The aqueous dispersion medium was filtered (the toner is now wet). The number average particle size of this polymerized toner was 10 g.

To this, an emulsion of zinc stearate (Hydrin E-619, manufactured by Middle East Oil Company, zinc stearate content 4)
0% by weight) and 1,000 g of water were mixed and stirred for 30 minutes at 10,000 r, p, m using a homomixer to disperse and adhere zinc stearate to the surface of the polymerized toner. After the l& medium was filtered and dried, fine particles such as fine toner powder, excess zinc stearate, and unreacted substances were removed using a classifier (Albine 18ONZR manufactured by HEYMAIV, West Germany).

The content of zinc stearate in the toner after classification was 1% by weight.

A developer was prepared by mixing 10 parts by weight of the obtained toner and 90 parts by weight of carrier particles made of triiron tetroxide and an epoxy resin and having an average particle diameter of 407 pm, and development was carried out under the following conditions.

The developing device shown in FIG. 2 was used. Image carrier 1
has a selenium photoreceptor, the circumferential speed of the photoreceptor is 100 mm/sec, and the maximum 'iR position of the electrostatic charge image formed on the image carrier 8 is +
750 V, the outer diameter of the sleeve 9 is 20 mm, its peripheral speed is 10 hm/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, the thickness of the developer layer is 200 P, ta, the gap between the sleeve 9 and the image carrier 8 is 300 JLm, and the bias voltage applied to the sleeve has a DC voltage component of +200V and an AC voltage component of 3.0KHz.
Development was carried out at 1400 Vpp. The electrostatic latent image was developed well, and the developed toner image was electrostatically transferred to plain paper and fixed at 180°C.

Table 1 shows the presence or absence of cleaning defects during initial and 1000-sheet image formation, the presence or absence of white streaks on one image, the amount of externally added toner remaining after 72W mesh sieving, and the results of the blocking test.

Example 2 The above components were mixed in an attritor for 4 hours, and this mixture 1
A monomer composition was prepared by mixing and stirring 100 g of paraffin wax 155'F, which had been melted at the same temperature, with 54 g kept at 75°C. The obtained monomer composition,
An aqueous medium of 1200 g of distilled water heated to 75° C. containing 10 g of amine-modified silica (100 parts by weight of Aerosil 200 treated with 5 parts by weight of aminopropyltriethoxysilane) and 12.5 g of 0.1N chloride. ToT,
Add it to the homomixer while stirring, and leave it for 15 minutes after adding it.
The mixture was stirred at 0000r, p, +s to perform 1-dispersion granulation. After granulation, the liquid temperature was lowered to 65°C, and 2,2'-
4 g of azobis-(2,4-dimethylvaleronitrile) and 2 g of 2,2'-azobisisobutyronitrile were added to the aqueous medium and stirred for an additional 30 minutes. Furthermore, stirring was changed to paddle blade stirring, and the mixture was stirred at 60° C. for 10 hours to complete one polymerization.

Washing of the polymerized toner, filtration of the dispersion medium, and mixing with the zinc stearate dispersion were carried out in the same manner as in Example 1. The number average particle size of the obtained polymerized toner was 10#L11,
The zinc stearate content after classification was 1% by weight. Images were drawn in the same manner as in Example 1 at 130°C and a pressure of 20 kg.
/cm2 hot pressure roll. The evaluation results are shown in Table 1.

Comparative Examples 1 and 2 The filtrated and undried polymerized toner obtained in Example 1.2 was dried, and 1 part by weight of zinc stearate powder was mixed with 100 parts by weight of the obtained polymerized toner using a coffee mill. Thereafter, it was mixed with a carrier in the same manner as in Example 1.2, and the same evaluation test was conducted.

Example 3 Zinc stearate was attached to the filtered polymerized toner obtained in Example 1 as follows.

After mixing 10 g of zinc stearate powder and 500 g of ethanol at room temperature, 700 g of water was added to the mixture, and T.
After preliminary dispersion for 3 minutes at 10,000 r, p, m using a homomixer, this dispersion was dispersed for 2 hours at a discharge pressure of 580 kg/cm2 using a piston-type high-pressure homogenizer (manufactured by Gorlin, model 15M-87A). The dispersion was circulated to uniformly disperse zinc stearate (required time: 3 minutes).

This dispersion liquid and the previously obtained filtered polymerized toner were mixed, and heated at 10,000 r using a homo mixer.
, p, m for 30 minutes to adhere the fatty acid metal salt to the surface of the polymerized toner. The evaluation of both sides was carried out in the same manner as in Example 1.

Example 4 Zinc stearate was attached to the filtered polymerized toner obtained in Example 2 in the same manner as in Example 3 to obtain a toner, and the image quality was evaluated in the same manner as in Example 2.

(Hereinafter in the margin) [Effects of the Invention] As described in 2 below, in the present invention, the fatty acid metal salt is attached to the toner surface without shearing force or heat generation, so that it does not impair the various properties of the toner. Furthermore, since the toner blocking property is maintained well and the doctor blade is not clogged with fused materials, white streaks do not occur on the image on the transfer paper.

This manufacturing method is particularly effective for toners containing large amounts of low softening point compounds.

[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) 3... 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, a fatty acid metal salt, and a liquid dispersion medium, and removing the liquid dispersion medium from this dispersion system, the fatty acid metal salt is added to the polymerized toner. A method for producing a toner for developing an electrostatic image, characterized by adhering it to a surface. (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.