JPS6278570A - Production of toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To eliminate fogging and to maintain high image quality for a long period of time by melting and mixing a mixture obtd. by melting and mixing a vinyl resin having a hydroxyl group and/or carboxyl group and electric charge controlling agent and binder resin. CONSTITUTION:The mixture obtd. by melting and mixing the vinyl resin having the hydroxyl group and/or carboxyl group and the charge controlling agent and the binder resin are melted and mixed. The vinyl resin has the hydroxyl group and/or carboxyl group preferably in such a ratio that the hydroxyl value or carboxyl value or the total thereof attains 50-350mgKOH/g. The compatibility with the charge controlling agent is deteriorated and there is a tendency to an increase of hygroscopicity and a decrease of electrostatic chargeability if the content of the group is excessively high or excessively low. The ratio of the vinyl resin and the charge controlling agent is 99/1-20/80 by weight. The content of the charge controlling agent in the toner decreases too much and the satisfactory electric charge is not obtainable if the ratio is too high. The resin component is too little and the melting and mixing are not satisfactorily executed if the ratio is excessively low.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing a toner for developing electrostatic images used in fields such as electrophotography and electrostatic recording.

(Prior Art) The electrophotographic method is described in U.S. Patent No. 2,297,691, British Patent No. 1,165,406, and British Patent No. 1,165,405. As described above, there is a charging process that applies a uniform electrostatic charge onto the photoreceptor using a photoconductive material, an exposure process that forms an electrostatic latent image by irradiating light, and a toner that adheres to the latent image area or non-latent image area. A developing process in which the image is transferred to an image support material such as paper, and a transfer process in which the image is transferred to an image support material such as paper as necessary.

It consists of a fixing process in which the toner image is attached to an image support material using heat, pressure, flash light, etc., a cleaning process to remove residual toner on the photoreceptor, and a static electricity removal process to remove static charges on the photoreceptor and return it to its initial state. , these steps are repeated to obtain a number of printed materials.

Toners for developing electrostatic images used in the fields of electrophotography and electrostatic recording include toners using styrene/acrylic copolymer resin as a binder resin (Japanese Patent Publication No. 11143/1983).
Toners using vinyl resins such as, toners using a bisphenol type epoxy resin obtained by reacting bisphenol and epichlorohydrin as a binder resin (Japanese Patent Application Laid-open No. 57
96354), a toner using a polyester resin obtained by reacting a glycol having a bisphenol skeleton with a polybasic acid as a binder resin (Japanese Patent Publication No. 52-254)
20), but vinyl resins have lower molecular weights and glass transition points than other resins.

The majority of toners are made up of toners using vinyl resins as binder resins because resin physical properties such as melt viscosity can be controlled over a wide range, which is extremely advantageous in terms of toner design.

Since these toners need to be charged with positive or negative electrostatic charge, a positive or negative charge control agent is added to the binder resin.

(Problems to be Solved by the Invention) Widely used vinyl resins such as styrene/acrylic copolymer resins contain nigrosine dyes, modified nigrosine dyes,
Since the compatibility of azo compounds with charge control agents such as metal complexes is poor and the charge control agents are not uniformly dispersed in the binder resin, toners obtained by mixing these materials have a positive (negative) charge on each toner particle. )
It was distributed over a wide range from 0 to 0 or negative (positive) 1, and many of the printed matter using this toner had capri.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a toner for developing electrostatic images that eliminates fog and maintains high image quality for a long period of time.

(Means for Solving the Problems) The present invention is a process of melt-mixing a binder resin and a mixture obtained by bath melt-mixing a vinyl resin having a hydroxyl group and/or a carboxyl group and a charge control agent. The present invention relates to a method for producing a toner for developing an electrostatic image, which comprises:

The vinyl resin having a hydroxyl group and/or carboxyl group in the present invention has a hydroxyl group and/or a carboxyl group with a hydroxyl value.

The carboxyl value or the total amount of these is 50 to 350 (mg
KOH/g).

If the amount of hydroxyl groups and/or carboxyl groups is too large or too small, compatibility with the charge control agent tends to be poor, hygroscopicity becomes poor, and chargeability tends to decrease.

As the resin having a hydroxyl group and/or a carboxyl group, a vinyl resin having a hydroxyl group and/or a carboxyl group is preferable.

Such vinyl resins include 2-hydroxyethyl methacrylate, 2-hydroxyglobyl methacrylate, hydroxybutyl methacrylate, and 2-hydroxy-3-phenyloxypropyl methacrylate.

2-Hydroxyethyl acrylate, 2-hydroxyglobyl acrylate, hydro Φ diptyl acrylate.

Vinyl monomers having a hydroxyl group such as 2-hydroxy-3-phenyloxypropyl acrylate and/or methacrylic acid, acrylic acid, and itaconic acid.

It is obtained by copolymerizing a vinyl monomer having a carboxyl group such as maleic acid or fumaric acid with another vinyl monomer. Other vinyl monomers include styrene, α-methylstyrene, p-methylstyrene, p-t-
Styrene derivatives such as butylstyrene, p-chlorostyrene, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, decyl methacrylate, onedecyl methacrylate methacrylate Dodecyl, glycidyl methacrylate, methoxyethyl methacrylate, propoxyethyl methacrylate, butoxyethyl methacrylate, methoxydiethylene glycol methacrylate.

Ethoxydiethylene glycol methacrylate, methoxyethylene glycol methacrylate, butoxytriethylene glycol methacrylate, methoxydipropylene glycol methacrylate, phenoxyethyl methacrylate,
Phenoxydiethylene glycol methacrylate, phenoxytetraethylene glycol methacrylate, benzyl methacrylate, cyclohexyl methacrylate, tetrahydrofurfuryl methacrylate, dicyclohentenyl methacrylate, dicyclopentenyloxyethyl methacrylate, N-vinyl-2-pyrrolidone methacrylate , methacrylotrile. Methacrylamide, N-methylolmethacrylamide, ethylmorpholine methacrylate, diacetone acrylamide, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, pentyl acrylate, hexyl acrylate, heptyl acrylate, octyl acrylate 1 Nonyl acrylate.

Decyl acrylate, undecyl acrylate, dodecyl acrylate, glycidyl acrylate, methoxyethyl acrylate, propoxyethyl acrylate, butoxyethyl acrylate, methoxydiethylene glycol acrylate, ethoxydiethylene glycol acrylate, methoxyethylene glycol acrylate, butoxy acrylate Trienalene glycol, methoxydipropylene glycol acrylate, phenoxyethyl acrylate, phenoxydiethylene glycol acrylate, phenoxytetraethylene glycol acrylate, benzyl acrylate,
Cyclohexyl acrylate, tetrahydrofurfuryl acrylate, dicyclopentenyl acrylate, dicyclopentenyloxyethyl acrylate, N-vinyl-2-pyrrolidone acrylate, glycidyl acrylate, acrylonitrile, acrylamide, N-methylol acrylamide, diacetone acrylamide , ethyl acrylate morpholine, vinyl monomers having one vinyl group in each molecule such as vinylpyridine, divinylbenzene, reaction products of glycol and methacrylic acid or acrylic acid 0 For example, ethylene glycol dimethacrylate, 1,
3-butylene glycol dimethacrylate, 1,4-butanediol dimethacrylate, 1,5-bentanediol dimethacrylate, 1,6-hexanediol diacrylate, neopentyl glycol dimethacrylate, diethylene glycol dimethacrylate.

Triethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, tripropylene glycol dimethacrylate, hydroxyhybalic acid neopentyl glycol ester dimethacrylate, trimethylolethane trimethacrylate, trimethylolpropane trimethacrylate, pentaerythritol tetramethacrylate, trismethacryloxyethyl phosphate .

Bis(methacryloyloxyethyl)hydroxyethyl isocyanurate, tris(methacryloyloxyethyl)in cyanurate, ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1
．． 4-butanediol diacrylate, 1,5-pentanediol diacrylate), 1,6-hexanediol diacrylate.

Neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, polyethylene glycol diacrylate,
Tripropylene diacrylate, hydroxypivalate neopentyl glycol diacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, pentaerythritol tetraacrylate.

Examples include vinyl monomers having two or more vinyl groups in one molecule, such as tris acryloxyethyl phosphate and tris (methacryloyloxy ether) in cyanurate.

Among these vinyl monomers, particularly preferred vinyl monomers having one vinyl group in one molecule include styrene, styrene derivatives, methacrylic esters, and acrylic esters.

In particular, alkyl esters of methacrylic acid or acrylic acid having 1 to 5 carbon atoms in the alkyl group are preferred. Among vinyl monomers having two or more vinyl groups in one molecule, divinylbenzene.

Dimethacrylates and diacrylates of methylene glycol having 2 to 6 carbon atoms are preferred.

These are used in 0 to 20 weight percent of the total vinyl monomers. These vinyl monomers having one vinyl group in one molecule and vinyl monomers having two or more vinyl groups in one molecule can be used alone or in combination of two or more.

These vinyl monomers can be polymerized in solution or in bulk.

Polymerization can be carried out by any method such as emulsion polymerization or suspension polymerization.

Polymerization initiators that can be used in the polymerization of and nyl monomer include acetyl peroxide, decanoyl peroxide, lauroyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide, 2,4-dichlorobenzoyl peroxide, and diisopropyl percarbonate. , di-2-ethylhexyl perdicarbonate, acetylcyclohexane sulfonyl peroxide, l11
-bis(t-butylperoxy)3. &5-) Limethylcyclohexane, tert-butyl peracetate, tert-butyl perisobutyrate, azobisisobutyronitrile, 21
2/ -Azobis-44-dimethylvaleronitrile, tert-butyl per-2-ethylhexanoate, t-perbenzoate
Known polymerization initiators such as er t-butyl may be used.

These are preferably used in an amount of 0.1 to 15% by weight based on the total amount of vinyl monomers. Moreover, it is preferable to use it by dissolving it in a vinyl monomer.

The charge control agent in the present invention is not limited to 0%, but includes nigrosine dyes, fatty acid-modified nigrosine dyes, carboxyl group-containing resin-modified nigrosine dyes, chromium complexes of azo compounds, cobalt complexes of azo compounds, iron complexes of azo compounds, etc. There are these salts. The salts of these complexes are expressed by the general formula (where T, Y and Z are each independently hydrogen.

Represents a halogen, carboxyl group, hydroxyl group, nitro group, sulfone group or sulfonamide group.

Metals such as MeFiCr, Co, and Fe, and M are hydrogen.

K, Na or fatty acid ammonium).

Examples of the binder resin in the present invention include polymers or copolymers of the other vinyl monomers mentioned above (vinyl polymers, particularly polymers containing the above-mentioned preferred vinyl monomers as an essential component), KR-216, KR-220, KR-152,
KR-271, Ni-255 (manufactured by Shin-Etsu Chemical)
, 5R-2400, 5R-2406, 5H-840 (manufactured by Toshi Silicone), or norbornene polymers such as Nosolex (manufactured by CdF Chemical), or C-20OA, C-2.
5OA (manufactured by Mitsubishi Chemical Corporation), Kneepilon-100
Polyester carbonate such as 0 (manufactured by Mitsubishi Gas Chemical ■), or polygonol R, -70, R-120°R,
-140, P-2 (more than lignite cleavage) xylene resin, Nirapol HR1220, 1032°1441
, lR2200, NBR2057S, 2007J (Nippon Zeon cleavage) and other diene resins, phenol resins, coumaron resins, amide resins, amide imide resins, butyral resins, amine resins, urethane resins, etc., and have low compatibility with charge control agents. The effects of the present invention are remarkable when these resins are used.

In the present invention, the ratio of the vinyl resin (3) having a hydroxyl group and/or carboxyl group to the charge control agent (B) is tA)/(B) in a weight ratio of 99/1 to 20/8.
0, preferably 9515 to 30/70. Particularly preferably, the ratio is 90/10 to 50,150. If this ratio is too large, there will be too few particles of charge control agent in the toner, and sufficient charge will not be obtained. If this ratio is too small, there will be problems such as insufficient resin content and insufficient bath melt mixing. There is.

In the present invention, the melt mixing of a resin having a hydroxyl group and/or a carboxyl group and a charge control agent, and the melt mixing of a mixture obtained by melt mixing these and a binder resin are carried out using a hot roll, a kneader, or a Banbury mixer. -1-
Temperature 9 at which the resin melts using a screw extruder, twin screw extruder, etc.
For example, it is carried out at 50 to 100°C.

In the present invention, 9 colorants and/or magnetic powders are melt-mixed at any time, but 9% is added during or after melt-mixing the mixture with a binder resin that has low compatibility with the charge control agent. Bath melt mixing is preferred.

Coloring agents include carbon black, acetylene black, Hansa Yellow G, cadmium yellow, molyftene orange, permanent orange, red red iron, rhodamine lake B, first violet B, methyl violet lake, dark blue, phthalocyanine blue, chrome green, and pigment green B. , zinc oxide, titanium oxide, nigrosine dye, methylene blue, rose bengal.

Quinoline Yellow, Ultramarine Blue, Chrome Yellow, Aniline Blue, Calco Oil Blue, Rhodamine 6G Lake, Watching Red Barium, Watching Red Strontium.

There are conventionally known pigments or dyes such as malachite green oxalate, DuPont oil red, and mixtures thereof, and these are preferably used in the toner in an appropriately selected range of 1 to 60% by weight.

Magnetic powders include metal powders such as iron, manganese, nickel, and cobalt, as well as aluminum and cobalt.

Steel, lead, magnesium, nickel, tin, alumina.

antimony, beryllium, bismuth, cadmium.

Alloys and mixtures of metals such as calcium, manganese, selenium, titanium, tungsten, vanadium, metal oxides such as aluminum oxide, iron oxide, steel oxide, nickel oxide, zinc oxide, titanium oxide, magnesium oxide, chromium oxide or alloys that exhibit ferromagnetism when heat treated.

For example, Heusler alloys such as manganese-copper-aluminum and manganese-copper-tin can be used, and when used, they are contained in the toner in an amount of 30 to 70% by weight.

The particle size of the magnetic powder is preferably 10 μm or less, particularly preferably 1 μm or less. By blending magnetic powder, a one-component toner can be obtained. In this case, it is generally not necessary to add the colorant as described above, but it may be added in an amount of 10% by weight or less to the toner.

Other additives may be added at any time during the production of the electrostatic charge developing toner of the present invention. The timing of addition is the same as for coloring agent 9 and/or magnetic powder, but it may be added and melt-mixed after these additions.

Other additives include fluidity improvers, cleaning improvers, offset inhibitors, and the like.

Fluidity improvers provide toner with high fluidity.

It facilitates the continuous supply of toner and forms visible images of good quality. Hydrophobic silica powder is most suitable as a fluidity improver. Such hydrophobic silica powder is a fine powder of silicon dioxide in which one surface silicon atom is a silanol group, for example, octyltrichlorosilane,
Decyltrichlorosilane, nonyltrichlor 7ran, 4
-Inglobylphenyltrichlorosilane, 4-ter
t-Butylphenyltrichlorosilane, dimethyldichlorosilane, dipentyldichlorosilane, dihexyldichlorosilane, dioctyldichlorosilane.

Dinonyldichlorosilane, didecyldichlorosilane, didodecyldichlorosilane, 4-tert-butylphenyloctyldichlorosilane, dioctyldichlorosilane, dibutenyldichlorosilane.

Dinonenyldichlor 7rane, di-2-ethylhexyldichlor//rane, di-3.3-dimethylpentylcyclosilane, trimethylchlorosilane, trihexylchlorosilane, trioctylchlorosilane, tridecylchlorosilane, dioctyl Hydrophobic groups are bonded to surface silicon atoms of silicon dioxide particles via oxygen atoms by reacting with compounds such as chlorosilane, octyldimethylchlorosilane, and 4-inglobyrphenyldiethylchlorosilane.

These hydrophobic silica powders have an average particle size of 1 mμ to
It is preferably within the range of 100 μm.

In particular, it is preferably between 2 mμ and 50 μm. If it is less than 1 mμ, the powder tends to scatter and is difficult to handle, and if it exceeds 100 μm, the photoreceptor is likely to be damaged.

Such hydrophobic silica powders include Aerosil R972,
Silica L)-17, R, 812, RA200H.

It is commercially available under trade names such as RX-C (9 Nippon Aerosil cleavage) and Tallanox 500 (manufactured by Tulco).

The toner may be manufactured by blending the hydrophobic silica powder as described above with other toner materials.

In particular, it is preferred to manufacture the toner in part with toner materials excluding the hydrophobic silica powder, and then add the hydrophobic silica powder.

When adding hydrophobic silica powder, hydrophobic silica powder is
0.0 for toner powder without hydrophobic silica powder
It is preferable to add it in an amount of 1 to 15% by weight. In particular, 0
．． The amount added is preferably 1 to 10% by weight. This addition amount is 0
．． It is less than 0.01% by weight.

The effect of improving fluidity does not appear, and even if it is added in excess of 15% by weight, the effect will not increase accordingly.

A part of the toner component of the cleaning property improving agent adheres to the surface of the photoreceptor or carrier. 9. Prevents the so-called filming phenomenon and facilitates long-term continuous use. , also always serves to form a clear visible image without capri.

Cleanability improvers include metal salts of saturated or unsaturated fatty acids such as maleic acid, stearic acid, oleic acid, palmitic acid, and caproic acid.

Linoleic acid, ricinoleic acid or ricylic acid with zinc, magnesium, calcium, cadmium.

Salts with lead, iron, nickel, cobalt, copper or aluminum may be mentioned, with 1% of zinc stearate, calcium stearate or magnesium stearate being preferred.

When a cleaning property-improving agent is used, it is particularly preferable that the cleaning property-improving agent is regularly added to the hydrophobic silica powder. The fatty acid metal salt is preferably added in an amount of 0.01 to 25 weight tS, particularly 0.1 to 10 weight %, based on the toner powder not containing the fatty acid metal salt and the hydrophobic silica powder. If the amount is less than 0.01% by weight, the effect of improving cleaning properties will not be exhibited. However, even if it is added in excess of 25% by weight.

It does not increase the effect.

It is generally advantageous to use a heat fixing method to fix a toner image on an image support, and this heat fixing method includes non-contact heat fixing methods such as oven fixing, and contact heating methods such as hot roll fixing. However, the contact heat fixing method has high thermal efficiency9
Equipment can be made smaller.

It has advantages such as low power consumption. However, in the contact heat fixing method, when the image support carrying the toner image passes through the heat roll, part of the toner image is transferred to the heat roll, and after the heat roll has made one revolution, the transferred toner image is transferred to the image support. There is a serious problem of re-metastasis and contamination. The anti-offset agent does not cause offset even in the hot roll fixing method and plays a role in forming high-quality images.

Anti-offset agents include ethylene, propylene, butene, pentene, hexene, and heptene.

octene, nonene, decene, 3-methyl-1-butene,
Polymers of olefin monomers such as 3-methyl-2-pentene and 3-7"copyru-5-methyl-2-hexene, or copolymers of the above-mentioned olefin monomers with acrylic acid, methacrylic acid, vinyl acetate, etc. Lower alcohol esters of fatty acids such as butyl stearate and propyl stearate, casta wax A (manufactured by Kao Soap)
, polyhydric alcohol esters of fatty acids such as diamond wax (Shin Nippon Rika), palm acetate (NOF)
), Hoechstwax E, Hoechstwax-〇P (
(Manufactured by Hoechst Akchengesellschaft), higher alcohol esters of fatty acids such as carnauba wax, Bisamide Frustflo (manufactured by Nitto Chemical Industries), Amide 6L, 7S and 6H (manufactured by Yoken Fine Chemicals), Hoechst Wax C (manufactured by Hoechst・Alkylene bis fatty acid amide compounds such as Akchen Gesellschaft).

Zinc stearate, calcium stearate, magnesium stearate, barium stearate.

Fatty acid metal salts such as copper stearate, aluminum stearate, zinc oleate, fugnesium oleate, zinc caprylate, magnesium caprylate, zinc linoleate, and calcium linoleate.

Nilaball NBR, 20578, 2007J, BR1
Diene resin with a weight average molecular weight of 50,000 or more, such as 220,
There are hydroxyl group-containing vinyl resins, carboxyl group-containing vinyl resins, and the like.

When an anti-offset agent is added, it is particularly preferred that the anti-offset agent be blended with other toner materials to produce the toner. The anti-offset agent is o in the toner.
It is preferably added in an amount of i to 50 weight, particularly 1 to 30 weight iφ. If it is less than 0.1% by weight, no offset prevention effect will be exhibited, and if it is added in excess of 50% by weight, the effect will not increase.

In the present invention, the fluidity improver as described above is used.

The cleaning performance improver and offset inhibitor may be added alone or in combination.

In the present invention, when melt-mixing, the mixing components are prepared in advance by
It is preferable to premix using a W cone, ■ blender, Henschel mixer, or the like.

In the present invention, the melt-mixed mixture is milled with a 7-Aser mill and pin milled before zero-order melt-mixing.

It is preferable to grind with a barberizer, hammer mill, etc. In addition, the finally obtained toner for developing an electrostatic image is as follows:
After passing through a similar pulverization process, it is classified into appropriate particle sizes and used.

(Example) The present invention will be explained below using nine examples.

Examples 1 to 5 Cod stalks (1) Synthesis of hydroxyl group- and/or carboxyl group-containing resin In a reaction vessel, add 200" parts of water, a suspending agent [Denka Popal W-24. manufactured by Denki Kagaku Kogyo ■] ] 0.3 parts by weight was charged, uniformly dissolved, heated to 90°C, and stirred.9 Add benzoyl peroxide, a polymerization initiator, to monomers having the composition shown in Table 1, -4#,! 1. A solution containing 2% by weight of kK was added dropwise over 2 hours.

Suspension polymerization was carried out, followed by 1 at 90°C with continuous stirring.
It was held for 0 hours. After cooling and filtering, the mixture was sufficiently dried to obtain a hydroxyl group- and/or carboxyl group-containing resin. Table 1 shows the hydroxyl value, carboxyl value, or their total value, and glass transition point of this resin.

(2) Production of toner The materials shown in Example 2 were melt-mixed in a pressure kneader at 140° C. for 1 hour to obtain a mixture. Next, the toner materials shown in Table 3 were melt-mixed at 130° C. using a twin-screw mixer, finely pulverized using a pin mill and a jet mill, and classified using a sliding sieve to obtain a toner having an average particle size of 13 mm.

(3) Manufacture of developer Toner 3 parts by weight and apparent density 3.5 to 4.5 g/art'
A developer was obtained by mixing with 97 parts by weight of iron oxide powder having a particle size content of 44 to 177 μm at 90% by weight or more.

(4) Test After uniformly positively charging a selenium drum rotating at a circumferential speed of about 20 cm/sec with a corona voltage of +6 KV, a latent image was randomly drawn with an e-Ne laser, and this was applied to Toner Storm 1 to Arashi 5. Reversal development was carried out using a magnetic plan method using a developer consisting of the following: Next, fixation was carried out using a pressure roll fixing machine.Table 4 shows the results of measurement using a microphotometer MPM type (Union Chemical Cleavage).

The print quality after printing 200,000 sheets is a change in print density.

Judgment was made based on increase in fog, etc.

As is clear from Table 4, when printing with the developer using the toners of Examples 1 to 5, prints showing good fixing strength (as judged from print # degree and capri density) were obtained, and 200,000 sheets were printed. No deterioration in print quality was observed even in this case.

Table 4 shows the results measured under the same conditions.

As is clear from Table 4, in the comparative example, the print quality deteriorated as printing continued.

The numerical unit of the O monomer composition is parts by weight.

0 Glass transition temperature measurement conditions Thermomechanical analysis method Verenation mode load 709. f/cm2 Heating rate 10℃/min Table 2
Composition of Materials The units of numerical values in Table 0 are parts by weight.

Table 4 Test results ☆Density is optical reflection density.

*Print density drops to 1.0 after 100,000 sheets, Kabu IJ 8
degree increased to 0.2.

(Effects of the Invention) The toner according to the method for producing a toner for developing an electrostatic image of the present invention has no fogging because the charge control agent is uniformly dispersed.
, :+tu 'IJ can be maintained for a long period of time.

In particular, the manufacturing method of Honjomei is particularly effective when manufacturing a toner using a binder resin that has low compatibility with the charge control agent.

Agent Patent Attorney Kunihiko Wakabayashi Procedural Amendment (Spontaneous) May 19, 1985 1. Indication of the case 1985 Patent Application No. 218837 2. Title of invention $f↑ Yu Seki Patent applicant name +4451 Hitachi Chemical Co., Ltd. Name
471E15) Patent attorney Kunihiko Wakabayashi 55
．． -2 is corrected to ``Load 70g-fJ.''

that's all

Claims (1)

[Claims] 1. The method is characterized by including a step of melt-mixing a binder resin and a mixture obtained by melt-mixing a vinyl resin having a hydroxyl group and/or a carboxyl group and a charge control agent. A method for producing toner for developing electrostatic images. 2. The method for producing a toner for developing electrostatic images according to claim 1, wherein the charge control agent is a metal complex of a nigrosine dye and/or a modified product thereof or an azo compound.