JPH0261650A - Production of toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To improve resolution, image density, gradation characteristic, cleanability, blocking resistance, and electrostatic charge stability by adding a dispersion of a coloring agent and/or magnetic powder to an emulsion polymn. liquid contg. polymer particles then flocculating thereof. CONSTITUTION:The emulsion polymn. liquid contg. the polymer particles is produced by emulsion polymn. of polymerizable monomers and is then mixed with the dispersion prepd. by dispersing the coloring agent and/or magnetic powder into water; thereafter, the particles in the resultant liquid mixture are flocculated. The emulsion polymn. is particularly preferably executed at 50 to 80 deg.C and is preferably progressed until the polymn. rate particularly attains >=99.9wt.%. The characteristics, more particularly preservable stability of the toner tend to be deteriorated if the polymn. rate is low and the residual monomers increase. The polymer produced by the emulsion polymn. is preferably so adjusted that the weight average mol. wt. thereof attains >=50,000. The cleanability and blocking resistance tend to be degraded if the weight average mol. wt. is too small.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for producing toner for electrostatic development using an emulsion polymerization method.

(Prior art) In electrophotography, after uniformly charging a photoreceptor,
The photoreceptor is exposed to a light image based on the original image, and the charge on the light-irradiated area is eliminated or reduced.

An electrostatic latent image based on the original image is formed on the photoreceptor.

Thereafter, it is visualized using a developer containing toner.

This visualized toner image is generally .

The image is transferred to a suitable transfer member and fixed to form a so-called copy.

The developer used in the above-mentioned Pro-Nananu basically consists of a coloring agent to visualize the electrostatic latent image and a binder to fix the developed image to the transfer body. These are broadly classified into so-called wet (liquid) developers and dry developers.

Dry developers can be further divided into two-component developers and -component developers, the former consisting of a carrier and a toner.
The latter consists only of toner. Toner υ, toner of opposite polarity to the electrostatic charge image necessary to develop the electrostatic charge image on the photoreceptor,
A two-component developer can be used to generate frictional electrification between carrier and toner.

On the other hand, a one-component developer is one that is charged by friction between toner particles or friction with other members in a developing device.

Conventionally, toners for such dry developers.

Generally, a coloring agent such as carbon black and/or a magnetic powder such as magnetite is melt-kneaded into a thermoplastic resin to form a dispersion, and then mechanical impact force is applied to the dispersion using an appropriate crushing device. The dispersion is ground to the desired particle size, and if necessary,
Toners have been produced by further classifying the toner (hereinafter, this method is referred to as the pulverization method).

Such methods not only require a large amount of energy for melt mixing and crushing.

Prepared toners necessarily have a number of drawbacks.

In particular, when using a desirable resin in the melt mixing process and the crushing process, 1. For example, if a resin that is easy to melt is used, capping may occur due to aggregation (caking) during toner storage or toner filming on the photoreceptor. Furthermore, if a resin that is easily crushed is used, it will be crushed in the developing machine, resulting in fine toner particles and dirt inside the machine.

In addition, the colorant dispersed in the resin appears on the surface of the crushed toner, resulting in a decrease in the amount of triboelectric charge in high humidity conditions and the colorant falling off in the developing machine. This causes undesirable phenomena such as contamination of the surface of the photoreceptor and contamination of the surface of the photoreceptor.

In order to solve the drawbacks of this pulverization method, 1% public
Japanese Patent No. 10799 proposes a method for producing truly spherical toner particles by spray drying an emulsion obtained by an emulsion polymerization method.

In addition, in order to solve the drawbacks of the pulverization method, toner manufacturing methods using a polymerization method and l~ are described in Japanese Patent Publication No. 51-14895 and Japanese Patent Publication No. 57-53756, etc., using a suspension polymerization method. A manufacturing method has been proposed. A perfectly spherical toner can also be obtained using the suspension polymerization method. If the obtained toner particles are truly spherical, the cleaning properties will be poor.

Therefore, as a method for obtaining an irregularly shaped toner that is not perfectly spherical by a polymerization method, particles in a polymerization solution obtained by an emulsion polymerization method using an emulsifier are coagulated, and an irregularly shaped toner with a particle size suitable for the toner is obtained by electrophotography. The manufacturing method of toner for
It is disclosed in Publication No. 8.

(Problem to be solved by the invention) As described in Japanese Patent Application Laid-Open No. 60-220358, 1
When emulsion polymerizing a polymerizable monomer in the presence of a coloring agent and/or magnetic powder, double polymerization may be significantly inhibited depending on the type of 1M colorant or magnetic powder, and single polymerization may not occur at all. Reactive monomer remains. In trench emulsion polymerization, a large amount of emulsifier and/or dispersion stabilizer is required to stably disperse colorant and/or magnetic powder during one polymerization.

These emulsifiers and/or dispersion stabilizers are mixed into the toner in large amounts during coagulation. Also, emulsifier and/or
Alternatively, since the dispersant is strongly chemically and physically adsorbed onto the surface of the polymer particles, it is difficult to easily remove it by washing after bipolymerization. Obi 10! The field test results showed that it was not possible to obtain uniform images over two years because t was significantly different.

(!!Means for Solving Problem 1) The present invention emulsion polymerizes a polymerizable monomer to produce an emulsion polymerization liquid containing polymer particles, and then disperses a colorant and/or magnetic powder in water. The present invention relates to a method for producing a toner for developing an electrostatic image, characterized in that the particles in the obtained mixed solution are coagulated after the particles are mixed with a dispersion solution.

The emulsion polymerization of the polymerizable monomer in the present invention is carried out by emulsifying and dispersing the polymerizable monomer in an aqueous medium containing an emulsifier and polymerizing the emulsion polymerization.

During this emulsion polymerization, an oil-soluble and/or water-soluble polymerization initiator can be added. others.

In some cases, anti-offset agents and charge control agents.

Toner property improvers such as fluidity improvers and IJ-improving agents, stabilizers for assisting emulsification and dispersion, and chain transfer agents may be added as appropriate.

As a method for emulsifying and dispersing the polymerizable monomer in an aqueous medium, the polymerizable monomer, the emulsifier, and the aqueous medium may be stirred and mixed simultaneously, or the polymerizable monomer is added to the aqueous medium in which the emulsifier is dissolved. However, they may be mixed by stirring.

The polymerization initiator may be added after this emulsification and dispersion, but
It is preferable to dissolve the water-soluble polymerization initiator in advance in an aqueous medium during emulsification and dispersion. Furthermore, when an oil-soluble polymerization initiator is used as the polymerization initiator, it is preferable to dissolve it in the polymerizable monomer in advance.

Stirring and mixing in the above emulsification dispersion may be carried out by stirring at a relatively high speed using an ordinary stirrer, but it is preferably carried out by stirring by high-speed shearing using a homomixer or the like. The same applies when dispersing the 9-polymerizable monomer and the toner property improver used as necessary.

The emulsion polymerization is preferably carried out at a temperature of 20 to 120° C. after or while emulsifying and dispersing the emulsion.
Preferably, it is carried out at a temperature of 0 to 80°C.

This emulsion polymerization is preferably carried out until the polymerization rate reaches 99% by weight or more, particularly preferably 99.9% by weight or more. Polymerization rate is low.

When the amount of residual monomer increases, the storage stability of the toner tends to be inferior to 9%.

Moreover, the polymer produced by the above emulsion polymerization is as follows.

the! It is preferable to adjust the weight average molecular weight to 5oooo or more. If the weight average molecular weight becomes too small, cleaning properties and blocking resistance tend to decrease. Note that in the present invention.

The weight average molecular weight is a value measured by gel permeation chromatography and calculated using a standard polystyrene calibration curve.

Further, the glass transition point of the obtained polymer is preferably 3
The temperature is adjusted to 0 to 90°C, particularly preferably 50 to 80°C.

If the glass transition point is too low, the blocking resistance tends to decrease, and if it is too high, the fixing ability tends to decrease. Adjustment of glass transition point.

This can be done mainly by selecting the polymerizable monomer to be used. Note that the glass transition point is measured using a differential scanning calorimeter (DSC).
It can be measured by

By such emulsion polymerization, the average particle size of the obtained polymer particles is 20 to 400 nm + especially 40 to 200 nm.
Preferably, it is m. outside of this range.

It is difficult to obtain a toner with good dispersibility.

Next, materials used for emulsion polymerization in the present invention will be explained.

The polymerizable monomers used in the present invention include styrene, 0
-Methylstyrene, m-methylstyrene.

p-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene.

p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, n-methoxystyrene, p-phenyl Styrene, such as styrene, p-chlorostyrene, and 3,4-dichlorostyrene, and ethylenically unsaturated monoolefins, such as His fV7 derivatives, ethylene, propylene, butylene, and imbutylene.

Vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide, vinyl fluoride, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, 2-enyl acrylate.

α-Methyl chloroacrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate.

α- such as n-butyl methacrylate, ibutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethyl-aminoethyl acrylate, dimethylaminoethyl methacrylate, etc.
Derivatives of acrylic acid or methacrylic acid such as methylene aliphatic monocarboxylic acid esters, acrylonitrile, methacrylic nitrile, acrylamide, methacrylamide, 2-hydroxyethyl acrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, Sometimes acrylic acid.

Methacrylic acid, maleic acid, fumaric acid, etc. can also be used to kill. vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone, N-vinylpyrrole, N-vinylcarbazole, and N-vinylindole. , N-vinyl compounds such as N-vinylpyrrolidone, vinylnaphthalene, etc. can be used alone or in combination of 221 or more.

Further, as the polymerizable monomer of the present invention, a compound having two or more polymerizable double bonds that serves as a crosslinking agent can also be used in part. aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene and their derivatives;
Diethylene carboxylic acid esters such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol triacrylate, trimethylolpropane triacrylate, all divinyl compounds such as N,N-divinylaniline, divinyl ether, divinyl sulfite, etc. The above vinyl group-containing compounds can be used alone or as a mixture. When a crosslinking agent is used, the amount used is preferably 200% by weight or less based on the total amount of 9 polymerizable monomers, particularly 5
It is preferable that it is less than % by weight.

The aqueous medium used in emulsion polymerization is primarily water. What is the ratio of the above polymerizable monomer to the aqueous medium?

The weight ratio of the former/latter is preferably 60/40 to 10/90. If this ratio is too large, emulsion polymerization becomes difficult, and if this ratio is too small, the yield of the 9 polymer tends to decrease.

As the emulsifier, anionic surfactants, cationic surfactants, zwitterionic surfactants, and nonionic surfactants can be used. Among these, when producing negatively chargeable toner, anionic surfactants are used,
When producing positively chargeable toners, it is preferable to use cationic surfactants. In these cases, in order to improve the two-dispersion stability, it is preferable to use a nonionic surfactant in combination.

Examples of anionic surfactants include fatty acid salts such as sodium oleate and potassium castor oil, alkyl sulfate esters such as sodium lauryl sulfate and ammonium lauryl sulfate, alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, and alkylnaphthalene sulfonates. , dialkyl sulfosuccinates, alkyl phosphate ester salts, naphthalene sulfonic acid formalin condensates, polyoxyethylene alkyl sulfate ester salts, and the like.

Nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxysorbitan fatty acid ester, polyoxyethylene alkylamine, glycerin, fatty acid ester, oxyethylene Examples include oxypropylene bromine polymer.

Examples of the cationic surfactant include alkylamine salts such as laurylamine acetate and nutearylamine acetate, and quaternary ammonium salts such as lauryltrimethylammonium chloride and stearyltrimethylammonium chloride.

Examples of the zwitterionic surfactant include lauryltrimethylammonium chloride.

The amount of emulsifier used is 0.0 based on the total amount of dipolymerizable monomers.
Preferably it is 1 to 5% by weight, especially 0.5 to 3% by weight. If the amount of emulsifier used is too low.

Stable emulsion polymerization becomes difficult, and if the amount is too high, the resulting toner will have poor moisture resistance.

Stabilizers include polyvinyl alcohol, starch,
There are water-soluble polymer substances such as methylcellulose, carboxymethylcellulose, and hydroxyethylcellulose.
These may be added in an amount of 1% by weight based on the polymerizable monomer as necessary.
Preferably, the following amounts are used:

Examples of the polymerization initiator that can be used in the present invention include persulfates such as potassium persulfate and ammonium persulfate, hydrogen peroxide, and 4,4'-azobiscyanovaleric acid.

42'-azobis(2-amidinopropane) dihydrochloride,
It is preferable to use water-soluble polymerization initiators such as t-butyl hydroperoxide and cumene hydroperoxide. Especially when using persulfates.

The sulfate anion radical (8
04-) is present on the monomer surface, and the particles are stabilized by the hydrophilicity and charge of the 504- group, making it easy to obtain an emulsion having a relatively uniform particle size. The amount of polymerization initiator used is 9
It is preferable that the amount is 0.01 to 5% by weight based on the polymerizable monomer, and particularly preferably KO11 to 3% by weight. If the amount of polymerization initiator is too small, the nine-polymerizable monomer will not be completely polymerized and will remain in the toner, resulting in a tendency for the properties of the toner to deteriorate. Furthermore, if the amount is too large, the moisture resistance of the toner tends to decrease.

Additionally, benzoyl peroxide as a polymerization initiator.

Oil-soluble polymerization initiators such as peroxides such as tert-butyl perbenzoate and azo compounds such as azobisisobutyronitrile and azobisisobutylvaleronitrile can be used in combination. The oil-soluble polymerization initiator is preferably used in an amount of 100% by weight or less based on the water-soluble polymerization initiator.

Further, the water-soluble polymerization initiator described above may be used in combination with a reducing agent. As a reducing agent, metabisulfite is used)
Generally known materials such as IJium and ferrous chloride can be used. The reducing agent does not necessarily need to be used, but when it is used, it is preferably used in an amount equal to or less than the amount of the water-soluble polymerization initiator.

Chain transfer agents include alkyl mercaptans such as t-dodecyl mercaptan, lower alkyl xanthogens such as diisopropyl xanthogen, carbon tetrachloride, carbon tetrabromide, etc., and are used in an amount of 0 to 2% by weight based on the dipolymerizable monomer. It is preferable to do so.

In the present invention, a dispersion in which a colorant and/or magnetic powder is dispersed in water includes water as a continuous phase.

The colorant and/or magnetic powder preferably has an average particle size of 2 to 2.
It is a liquid that is dispersed in the form of fine particles of 500 nm. Good dispersibility is difficult to obtain with average particle diameters other than this. Note that the dispersion liquid may be in the form of a paste.

Coloring agents include pigments or dyes, 9 for example various carbon blacks, nigrosine dyes (C, 1
, Nn50415), Aniline Blue (C, 1, Arashi 5)
0405), Calco Oil Blue (C.

1, NQ azoec Blue 3) + Chrome Yellow (C, L Koji 14090), Ultramarine Blue (C0I, N1177103), DuPont Oil Red (C, 1, Nα26105), Orient Oil Red ÷ 330 (C, 1, Constant 60505) ),
Quinoline yellow (C, LNa47005), methylene blue chloride (C.

1, N1152015), Phthalocyanine Blue (
C4NQ74160), Malachite Green Oxale) (C, 1, N114200 OL Lamp Black (C, L Demon? 7266), Rose Bengal (
C-1, MA45435), oil black, azo oil black, etc. can be used alone or in combination. These colorants can be used in any amount, but in order to obtain the required concentration and for economic reasons, about 1 to 30% by weight in the toner.

It is preferably used in a proportion of 5 to 15% by weight.

Magnetic powder is used when manufacturing magnetic toners, and it can optionally double as a colorant. Preferred magnetic powders include iron or nickel, such as magnetite or ferrite.

There are oxides or compounds of elements that exhibit ferromagnetism, such as cobalt. Further, the surface of the magnetic powder may be treated with a resin, a titanium coupling agent, a silane coupling agent, a higher fatty acid metal salt, or the like. The content of these magnetic powders is 20 to 80% by weight based on the toner.

Preferably, it can be contained in an amount of 35 to 70% by weight.

Less than this amount may be used as a coloring agent.

As for the method for producing a dispersion liquid in which these colorants and/or magnetic powders are dispersed in water, there is no limit to 9% except that water is used as a dispersion medium. If necessary, a surfactant, a buffer, an oligosoap, a dispersion stabilizer such as a water-soluble polymer, etc. may be added. It should be noted that these additives are strongly chemically and physically adsorbed on the surface of the bipolymer particles when present during monomer polymerization.

Although it cannot be easily removed by washing or the like, if it is added after one polymerization is completed, it will not be adsorbed to the surface of the 9-polymer particles, so it can be easily removed by washing or the like.

In addition, the above-mentioned dispersion liquid includes an aqueous processing pigment dispersion used in the field of water-based coloring processing such as water-based paints, coloring liquids for building materials, dyeing liquids for dyeing and miscellaneous materials, and water-based inks [for example, BM Color (manufactured by Toyo Ink Manufacturing Co., Ltd.)] , Bikku) IJ Acolor (manufactured by Martyr's Color ■)] and pressure seals.

It is also possible to use an aqueous magnetic fluid used for liquid damper rotary shaft seals and the like.

Next, other additives will be explained in detail.

An offset inhibitor is used as necessary.

The offset inhibitor can be present in the system in various forms during or after the double polymerization, and can be included in the toner product. Alternatively, the anti-offset agent can be added later to a toner in which it is not present. The most preferred method is to mix a dispersion of this in water into an emulsion polymerization solution before coagulation. The anti-offset agents mentioned above include nine different natural waxes, such as carnauba wax.

Examples include hydrogenated castor oil and low molecular weight olefin polymers, and preferably low molecular weight olefin polymers are used. As this low molecular weight olefin polymer, a low molecular weight olefin polymer or a copolymer of an olefin and a monomer other than olefin is used. Here, as an olefin.

Examples of monomers other than olefins include ethylene, propylene, and butene-1, and examples of monomers other than olefins include acrylic esters and methacrylic esters. Examples of this low molecular weight olefin polymer include the polyalkylene described in JP-A No. 55-153944, and the polyalkylene described in JP-A No. 50-9364.
The low molecular weight olefin copolymer described in Japanese Patent No. 7 can be used.

In the present invention, the low molecular weight olefin polymer may be one that is included in the concept of low molecular weight in ordinary polymer chemistry, and generally has a weight average molecular weight t (Mw) of 100.
0~45000. Preferably it is 2000-6000.

The low molecular weight olefin polymer used in the present invention is:

It is preferable to have a softening point of 13θ to 160°C at 9% of 100 to 180°C.

The amount of the low molecular weight olefin polymer that can be used in the present invention is not particularly limited, but is preferably in the range of 0 to 30 wt.tts, more preferably 1 to 30 wt.% based on the total amount of the toner. be done.

Furthermore, fluidity improvers, cleaning performance improvers, etc. can be used as necessary. these are.

It can be present in the polymerization reaction system or in the emulsion polymerization solution after completion of the pentapolymerization, and can also be present in the product toner, but preferably it is externally added to the product toner afterwards. These contents are respectively 0 and 0 for the toner obtained by the present invention.
It is preferable that it is 3 weight t%. Silane and titanium are used as fluidity improvers.

There are 9 types of oxides of aluminum, calcium, magnesium and magnesium, or the above oxides, which are treated with a titanium coupling agent or a silane coupling agent to make them hydrophobic.As a cleaning property improver, zinc stearate, lithium stearate, etc. and metal salts of higher fatty acids such as magnesium laurate or aromatic acid esters such as pentaerythritol benzoate.

In the present invention, also by selecting the polymerizable monomer and the colorant. The charge amount and charge polarity of the product toner can be freely adjusted by adjusting the amount of emulsifier, but in order to adjust the band 11 and charge polarity to desired values, in the present invention, the charge control agent is added to the colorant. It can also be used in combination with.

The charge control agent may be present in the polymerization reaction system, present in the product toner, or dispersed in water to solidify the dispersion (
It may also be mixed into the emulsion polymerization solution and coagulated (salted out) before being present in the product toner. As the charge control agent suitably used in the present invention, 9, for example, Subiron Black TRH
, Spironflux TPH (manufactured by Hodogaya Chemical Co., Ltd., trademark), etc. 1 Aromatic acid derivatives such as p-fluorobenzoic acid, p-nitrobenzoic acid, 2,4-di-t-butylsalicylic acid, etc. 1. Examples include tin compounds such as dibutyl-tin oxide and dioctyl-tin oxide. These are 0 to 5% by weight based on the main resin components.
It is preferable to use

In the method of the present invention, an aqueous dispersion of a colorant and/or magnetic powder and other additives as necessary is added to an emulsion polymerization solution containing polymer particles obtained by emulsion polymerization, and mixed uniformly. After making a mixture.

The particles in the liquid mixture are coagulated to a particle size suitable for toner.

Specifically, the average particle size of the coagulated particles is 2 to 25 μm,
In particular, it is preferable to adjust the thickness to 3 to 15 μm.

For the above adjustment, the coagulant is preferably used in an amount of 0.1 to 5 times, particularly preferably 0.3 to 3 times, the weight of the emulsifier in the emulsion polymerization solution. If the amount of coagulant used is too small, the coagulation effect will be insufficient, and if it is too large, the moisture resistance of the toner will be poor and the average particle size of the particles will be too large, making the toner unsuitable.

In this coagulation step, the polymerization liquid and coagulant are mixed by a method of dropping the polymerization liquid little by little into an aqueous solution of the coagulation agent while stirring;
This can be carried out by, for example, a method of mixing an aqueous solution of a coagulant and a polymerization liquid at a fixed ratio.

By these methods, the bipolymer particles and the colorant and/or magnetic powder were uniformly mixed by mixing with an aqueous solution of a coagulant at a temperature below the glass transition point of the tzu polymer particles and coagulating them. It is preferable to generate floc-like particles and then heat-treat the polymer particles at a temperature higher than the glass transition point of the polymer particles.

Such heat treatment increases the bulk density of the resulting particles and improves their moisture resistance, offset resistance, and durability.

In the coagulation step, a method may be considered in which a large amount of coagulant is added to the emulsion polymerization liquid to obtain a large coagulated body, which is then ground to a size of 9 particles suitable for toner.

This method compared to toner by crushing method.

Although this method has the effect that the additive can be uniformly dispersed in the resin, the cost is higher than that of the toner according to the present invention because of the pulverization.

On the other hand, in the present invention, the particles obtained by coagulation can be made into a toner as is or by simply classifying them, and the shape of the toner particles is as follows.

It is different from the asymmetric amorphous shape of the pulverized toner, and is not perfectly spherical, but has an imperfect spherical shape, so it has excellent cleaning properties.

Examples of the coagulant include inorganic acids such as hydrochloric acid and sulfuric acid, organic acids such as formic acid and oxalic acid, and water-soluble metal salts of these acids and alkaline earth metals, aluminum, etc. These coagulants can be used alone or in combination, but preferred coagulants are magnesium sulfate, aluminum sulfate, barium chloride, magnesium chloride, calcium chloride, sodium chloride, and/or a mixture of these and an inorganic acid. It is preferable to use these coagulants as a 0.1 to 10 tlL aqueous solution, particularly KO11 to 5% by weight aqueous solution.

The particles obtained through the coagulation process (and heat treatment process) appear in the form of a slurry, which can be centrifugally dehydrated to isolate the particles, which are further washed and dried, and further processed as needed. The toner for developing an electrostatic image can be obtained by classifying the toner accordingly.

Here, washing is preferable in order to completely remove the polymerization initiator residue, coagulant, etc. adhering to the two particles, and this K improves the above-mentioned coagulation as well as charging stability and blocking resistance. Can be done. Washing is preferably carried out with warm water of 40 to 60°C.

Note that the post-solidification heat treatment operation may be inserted during the washing step or between two or more washing steps.

The toner obtained (according to the present invention) is obtained by the development process of S.
For example, the cascade method described in U.S. Pat. No. 2,618,552, U.S. Pat. No. 2,874,0
The magnetic brush method described in US Pat. No. 65, the powder cloud method described in US Pat. No. 2,221,776, and the powder cloud method described in US Pat. No. 3,166,432. Touchdown development method 1% 1977-
The so-called jumping method described in Japanese Patent No. 18656, the so-called microtoning method in which the necessary toner charge is obtained by using a pulverization method as a carrier, the so-called bipolar magnetic toner method in which the necessary toner charge is obtained by frictional charging between magnetic toners, etc. Can be used.

Furthermore, the toner obtained according to the present invention can be used in various fixing methods, such as so-called oil-less and oil-coated heat roll methods, flash methods, open methods, pressure fixing methods, and the like.

Furthermore, the toner of the present invention can be used in various cleaning methods such as the so-called fur brush method and blade method.

(Example) Next, the present invention will be explained by referring to an example, but the present invention is not limited thereto. In the example.

"%" means "% by weight" unless otherwise specified.

Example 1 (1) Production of emulsion polymerization solution In a stainless steel beaker of No. 31, ion exchange water No. 13009 was added.
An aqueous solution was prepared by dissolving sodium dodecylbenzenesulfonate 69, an anionic surfactant as an emulsifier, and ammonium persulfate 129 as a polymerization initiator.

Next, a uniformly mixed solution of 120 g of styrene 4009° acrylic butyl as a dipolymerizable monomer and 0.69 g of t-dodecyl mercaptan as a chain transfer agent was added to the aqueous solution, and emulsified for 1 minute at 3.00 Orpm using a homomixer. A pre-emulsion was obtained.

Next, the pre-emulsion was transferred to a 31 four-piece removable flask equipped with a stirrer, a nitrogen inlet, a thermometer, and a condenser, and the temperature of the flask was adjusted to 70°C under a nitrogen stream.
After polymerization for 5 hours.

It was cooled to obtain an emulsion polymerization liquid.

When this emulsion polymerization solution was filtered through a 400 mesh wire mesh, no aggregates remained on the wire mesh. Further, no deposits were observed on the stainless steel stirring blade.

From these results, it was found that the emulsion polymerization liquid had good dispersion stability. Furthermore, the polymerization rate at this time was 99.
It was over 5 inches. In addition, the weight average molecular weight (Mw) of 9 polymer was measured by molecular IT gel permeation chromatography using a calibration curve using standard polystyrene: 9 weight average molecular weight (Mw) 86000° number average molecular weight (Mn) 3000
It was 0. Also.

Coulter #! The average particle size of the polymer particles in the emulsion polymerization solution was examined using an N4 submicron particle size distribution analyzer (light scattering method) and was found to be approximately 80 nm.

(2) Coagulation step and heat treatment step BMP black (carbon black dispersion aqueous solution manufactured by Toyo Ink Manufacturing ■, carbon content 40%,
Average particle size approximately 200n by N4 submicron particle size distribution meter
m) 130g was added and mixed well.

1 g of the obtained mixture was uniformly dropped into 1 liter of a 3% magnesium sulfate aqueous solution heated to 60° C. over about 30 minutes with thorough stirring, and solidified. The obtained slurry was transferred to an autoclave, heat-treated at 120°C for 30 minutes, and cooled to room temperature.

(3) Final step Next, after dehydrating this slurry with a centrifugal dehydrator,
Washing was repeated three times with warm water at °C.

Next, it was dried in a dryer at 30 to 35°C to obtain a toner. The particle size of the obtained toner was measured using a Coulter counter, and the particle size was 1 to 50 μm.

The average particle size was 13 μm. Furthermore, when the glass transition point (Tg) was measured using a differential scanning calorimeter, it was 73°C. This toner is further processed using a zigzag classifier (100MZR,
When the mixture was classified into 5 to 25 μm particles using Alpin Co., Ltd., the yield was 90% of that before classification.

In addition, in the following Examples and Comparative Examples, the particle size and average particle size of the toner were measured using a Coulter counter.

The average particle size of the polymer particles in the emulsion polymerization solution and the particles of the colorant and/or magnetic powder in the dispersion liquid was measured with an N4 submicron particle size analyzer, and the glass transition point was measured with a differential scanning calorimeter.
Classification was performed using a zigzag classifier.

Example 2 A dispersion prepared by the following method was used in place of the EM color. Carbon Black Na4 in 760g of ion-exchanged water
4 (Mitsubishi Chemical Industries Exhibition) 2oog.

Demol N (manufactured by Kao ■) iog was added as a surfactant and mixed well. Next, mix this mixture with a homomixer.
ORPM for 30 minutes to give carbon black an average particle size of 200 nm.

Example 1, (1
), coagulation, heat treatment, washing, and final steps were performed in the same manner as in Example 1 to obtain a toner having an average particle size of 13 μm.

Comparative Example 1 Production of emulsion polymerization solution Carbon black Φ44 was placed in a stainless steel beaker of 31.
529. Add styrene 4009 as a polymerizable monomer, 120 g of butyl acrylate, and 0.69 g of t-dodecyl mercaptan as a chain transfer agent, and mix with a homomixer at 300 g.
Mixing and dispersion was carried out for 30 minutes using Or, plm.

Next, 1.300 g of ion-exchanged water was added to this carbon dispersion.
An aqueous solution containing 6 g of sodium aldodecylbenzenesulfonate dissolved in an anionic surfactant as a sLC emulsifier and ammonium persulfate 129 as a polymerization initiator was added, and the mixture was further emulsified with a homomixer at 3000 r, p, m for 30 minutes to form a black pre-emulsion. I got it.

Next, the black pre-emulsion was transferred into a 3/4-inch parallel flask equipped with a stirrer, nitrogen inlet, thermometer, and condenser, and the temperature of the flask was kept at 70°C under a nitrogen stream for 5 hours. The mixture was cooled to obtain an emulsion polymerization solution.

This emulsion polymerization solution was filtered through a 400-mesh wire mesh, and the aggregate on the wire mesh was dried and weighed, and the weight was about 1,809. A large amount of deposits were also observed on the stainless steel stirring blades.

These results revealed that the two-dispersion stability was very poor. Therefore, this emulsion polymerization solution was not converted into a toner.

Comparative Example 2 (1) Production of emulsion polymerization solution Polymerization was carried out in the same manner as in Comparative Example 1 except that the amount of sodium dodecylbenzenesulfonate was changed to 309. Adherence was observed. In addition, the average particle size of the bipolymer particles is approximately 300
It was nm.

(2) Coagulation process/heat treatment process Above emulsion polymerization liquid II! 3% magnesium sulfate aqueous solution II! heated to 6e℃! While stirring thoroughly, drop the mixture evenly over about 30 minutes and allow it to solidify. The obtained slurry was transferred to an autoclave and heat treated at 120°C for 30 minutes.
Cooled to room temperature.

(3) Final step The final step was carried out in the same manner as in Example 1, and the average particle size was 13 μm.
m toner was obtained.

Comparative Example 3 In the production of an emulsion polymerization solution, in addition to 6 g of sodium didodecylbenzenesulfonate, Demol Niog was added as a surfactant, and nine polymers were polymerized in the same manner as in Comparative Example 1. The amount of aggregates was about 209, and deposits were observed on the stainless steel stirring blade.

The average particle size of the 9 polymer particles was about 250 nm.

Furthermore, in the same manner as in Comparative Example 2, a solidification step, a heat treatment step, and a final step were performed to form a toner. The average particle size was 13 μm.

Comparative Example 4 Polymerization was carried out in the same manner as in Comparative Example 2, except that 209% of Demol N was added. There were no aggregates or deposits on the stirring blades. Further, the average particle size of the polymer particles was about 250 nm. A solidification step, a heat treatment step, and a final step were performed to obtain a toner of 13 μm.

Example 3 Ion exchange water 1.3009 in a 31 stainless steel beaker
e Sodium dodecylbenzenesulfonate 159 was dissolved using an emulsifier.

Next, styrene 4009° and butyl acrylate 1209° were used as polymerizable monomers. t-dodecyl mercaptan 0.6
9. Penzoyl peroxide 159 as a polymerization initiator
Mix uniformly, add the solution to the aqueous solution, and emulsify with a homomixer at 3.00 Orpm for 1 minute to form a pre-emulsion t-i+.

This pre-emulsion was emulsion polymerized in the same manner as in Example 1 to form a circle. No aggregates or deposits were observed in the emulsion polymerization solution obtained. The average particle size of the nine-bonded particles is approximately 100 nm, which is a good value. 260 g of the same carbon black dispersion as that prepared in Example 2 was added to this emulsion polymerization liquid, mixed well, and the coagulation process, heat treatment process, and final process were carried out in the same manner as in Example 2 to obtain a toner with an average particle size of 14 μm. Obtained.

Comparative example 5 31! Carbon black in a stainless steel beaker◆4
4 529. Styrene 4009, butyl acrylate 1209. as polymerizable monomers. t-dodecyl mercaptan 0
．． Add 6 g of benzoyl peroxide 159 as a polymerization initiator, mix well, and add 3.000 g of benzoyl peroxide as a polymerization initiator.
Mix and disperse for 30 minutes at rpm.

Next, 1.300 g of ion-exchanged water was added to this carbon dispersion.
g, )'7'' silbenzenesulfonic acid) IJium 69p Demol N209 was added and dissolved in an aqueous solution, which was then emulsified for 30 minutes using a homomixer at zooorpm to obtain a black gray emulsion.

Next, 31! was equipped with a stirring device, nitrogen inlet, thermometer and condenser! The black pre-emulsion was transferred into a 2-Pulle flask, and the flask was kept at a temperature of 70° C. for 5 hours under a nitrogen stream. Since the monomer odor was strong, the polymerization rate of non-volatile substances was determined and was found to be less than 5%.

Example 4 Example 10 Instead of EMP color, Victoria Color Red (manufactured by Mikuni Shiki ■, average particle size of about 10,100 nm, 200
The average particle size was 13 μm in the same manner as in Example 1 except that g was used.
A red color toner was obtained.

Example 5 Instead of the EMP color of Example 1, Victoria color blue (Ryogoku dyestuff, zoo
The average particle size was 13 μm in the same manner as in Example 1 except that g was used.
A blue color toner was obtained.

Example 6 In Example 1, the EMP color was changed to 659. A magnetic toner having an average particle size of 13 μm was obtained in the same manner as in Example 1, except that 400 g of Okamura Oil Co., Ltd. magnetic powder fraction acid solution (solid content: about 60 cm, average particle size: 30 nm) was added.

The toners obtained in Examples 1 to 5 and Comparative Examples 2 to 4 were tested for electrophotographic toner properties using a DC-111 plain paper copying machine manufactured by Sanda Kogyo. Further, in Example 6, Minicopia PC-25 manufactured by Canon ■ was used.

However, each toner has a fluidity improver.

Hydrophobic silica (manufactured by Nippon Aerosil ■, R-972) and zinc stearate were each added at a rate of 0.6 to the above toner.
% and 0.1% were used for external addition treatment. Test results first
Shown in the table.

The electrophotographic properties were evaluated as follows.

(Al Resolution: Using the Electrophotographic Society Test Chart Megumi 1, copies were made on plain paper using the respective developers. Evaluation was made by comparing whether the copied images could be read in detail.

(b) Image Density 2 The density of the black part of the copied paper was measured using a Macbeth densitometer in the same manner as the resolution, and was evaluated as 2. (However, Examples 4 and 5 are excluded.) (C) Gradation: Evaluation was made in the same manner as resolution using the 11-level gray area in the center of the test chart.

(dl Cleanability: Each of the prepared developers was continuously copied using a copying machine at a temperature of 30° C. and a relative humidity of 80q6, and evaluated by the number of copies until cleaning failure occurred.

(e) Blocking resistance: The prepared toners were left at 50°C and 95% humidity for 72 hours.

It was determined whether or not the toner caused blocking, and evaluation was made based on the following criteria.

◎: Very good ○: Excellent △: Slightly inferior ×: Poor) Charging stability: Each of the prepared developers was stirred with four machines, and the amount of charge was measured at regular intervals, and the amount of charge was determined. It was judged based on the change in , and evaluated using the following criteria.

◎: Very good O: Excellent △: Slightly inferior ×: Poor (g) Durability: Using a copying machine, each developer was tested at a temperature of 30 degrees Celsius and a relative humidity of 80 degrees centigrade.
00 copies were made continuously. The toner scattering that occurs at this time was investigated and judged based on the following evaluation.

◎: No toner scattering ○: Some toner scattering Δ: A lot of toner scattering ,
Temperature 10℃, humidity 20tl; temperature 20℃, humidity 60tl;
Leave it for 24 hours at a temperature of 30°C and a humidity of 80%, and calculate the moisture absorption rate (%) by calculating the weight increase after humidification relative to the weight before humidification.
).

(1) Environmental resistance: The prepared toners were tested at low temperature and low humidity (10°C, 40%) and high temperature and high humidity (30°C).

5od) on plain paper, and the image density under low temperature and low humidity is divided by the image density under high temperature and high humidity. (Excluding Example 4.5.) The results are shown in Table 1.

(Effects of the Invention) In the production method of the present invention, it is sufficient to use a small amount of the rounding emulsifier, which is obtained by adding a dispersion of a colorant and/or magnetic powder to an emulsion polymerization solution containing bipolymer particles and coagulating it. The yield of toner is also increased.

Also, because the amount of emulsifier etc. mixed in is small, resolution is improved.

It has excellent two-tone image density, cleaning performance, blocking resistance, and charging stability, as well as eK.

It is possible to obtain a toner for developing electrostatic images that has excellent environmental resistance and is suitable for dry development.

Claims (1)

[Claims] 1. After producing an emulsion polymerization solution containing polymer particles by emulsion polymerization of a polymerizable monomer, and then mixing it with a dispersion solution in which a colorant and/or magnetic powder is dispersed in water. A method for producing a toner for developing an electrostatic image, characterized by coagulating particles in the obtained mixed liquid. 2. The average particle size of polymer particles in the emulsion polymerization solution is 20 to 40.
2. The method for producing an electrostatic image developing toner according to claim 1, wherein the toner has a particle diameter of 0 nm. 3. The average particle size of the colorant and/or magnetic powder in the dispersion is 2.
3. The method for producing a toner for developing an electrostatic image according to claim 1 or 2, wherein the toner has a particle diameter of 500 nm. 4. During coagulation, first coagulate at a temperature below the glass transition temperature of the polymer particles to generate floc-like particles in which the polymer particles and the colorant and/or magnetic powder are uniformly mixed, and then 4. The method for producing an electrostatic image developing toner according to claim 1, wherein the toner is heat-treated at a temperature higher than the glass transition temperature of the particles.