JPS61167957A - Preparation of electrophotographic toner - Google Patents

Abstract

PURPOSE:To obtain superior cleanability, triboelectrification stability, and blocking resistance by emulsifying a water-soluble polymn. initiator in the presence of an emulsifier and solidifying the obtained polymer to particle diameters in a polymerized dispersion suitable for a toner. CONSTITUTION:The polymerizable monomer, a colorant and/or a magnetic powder, and an oil-soluble polymerization initiator, and a water-soluble polymerization initiator in an amt. smaller than the former initiator are emulsified in the presence of an emulsifier, and the obtained polymer dispersion is solidified to particle diameters suitable for the toner. The polymn. is performed after emulsification or during emulsification operation at a temp. of 20-120 deg.C to attain >=99wt% polymn. yield. The emulsified is added in an amt. of 0.01-10wt% of the polymerizable monomer, and as a solidifying agent, magnesium sulfate and/or aluminum sulfate and/or an inorg. salt are used in an aq. soln. of 0.1-10wt%, especially, 0.1-5wt%, thus permitting the obtained electrophotographic toner to be superior in cleanability, triboelectrification stability, and blocking resistance.

Description

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

(Prior art) In electrophotography, after uniformly charging a photoreceptor,
exposing the photoreceptor to a light image based on the original image;
Eliminate or reduce the charge on the light-irradiated area.

Forms an electrostatic latent image on the photoreceptor based on the original image.

Thereafter, it is visualized using a developer containing toner. This visualized toner image is generally transferred to a suitable transfer member and fixed thereon to form a so-called copy.

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

Dry developers can be further divided into two-component developers and one-component developers, with the former consisting of a carrier and toner, and the latter consisting only of toner. In other words, a two-component developer is one that obtains toner of opposite polarity to the electrostatic charge image needed to develop the electrostatic charge image on the photoconductor by triboelectrically charging the carrier and toner. A one-component developer is one that is charged by friction between the components or by friction with other members in the developing device.

Conventionally, toner for such a dry developer is generally produced by melting and kneading a colorant such as carbon black and/or magnetic powder such as magnetite into a thermoplastic resin to form a dispersion, and then processing the resulting dispersion using a suitable pulverizer. The toner has been produced by applying mechanical impact force to pulverize the dispersion to a desired particle size, and if necessary, further classifying it to form a toner (
below.

This method is called the crushing method).

Furthermore, 1% Publication No. 43-10799 proposes a method for producing completely spherical toner particles by spray drying an emulsion obtained by emulsion polymerization.

In addition, Japanese Patent Publication No. 14895/1989 discloses a toner manufacturing method using a polymerization method to solve the drawbacks of the pulverization method. A method for producing toner using a suspension polymerization method is proposed in JP-A No. 57-53756 and the like. When using the suspension polymerization method, a perfectly spherical toner can be obtained.

(Problems to be Solved by the Invention) However, the pulverization method is not a foolproof method as it requires a large amount of energy for melting and pulverizing.

The produced toner necessarily has a number of drawbacks.

In particular, when using desirable resins in the melt mixing process and the pulverization process, 2. For example, when using resins that are easy to melt, toner aggregation (caking) during storage and fogging due to toner filming on the photoconductor may occur. invite the
Furthermore, if a resin that is easily crushed is used, it will be crushed into fine toner particles in the developing device, resulting in image fogging and dirt inside the machine.

In addition, the colorant dispersed in the resin appears on the surface of the pulverized toner, which may cause a decrease in the amount of triboelectric charge in high humidity conditions or drop-off of the colorant in the developing machine.
This causes undesirable phenomena such as contamination of the carrier surface and contamination of the photoreceptor surface.

On the other hand, toners obtained using emulsion polymerization-spray drying and suspension polymerization have been found to solve some of the drawbacks of toners obtained by grinding methods, but introduce new drawbacks. Namely.

Since the obtained toner particles are perfectly spherical, they have poor cleaning properties. Since the emulsifier or suspending agent remains in the toner particles, charging stability and blocking properties are reduced.

The present invention solves these problems in the conventional toner manufacturing method and improves image density and image density.

An electrophotographic toner that is suitable for dry development, has excellent two-tone resolution, and has particularly excellent cleaning properties, charge stability, and blocking properties, and is produced using a polymerization method, and does not require a pulverization process. The present invention provides a method for manufacturing.

(Means for Solving the Problems) The present invention consists of one polymerizable monomer, nine colorants and/or magnetic powders, and an oil-soluble polymerization initiator or an oil-soluble polymerization initiator of the same weight as the polymerization initiator. Emulsifying and dispersing a less water-soluble polymerization initiator and polymerizing it to produce a main resin component, and coagulating the obtained polymerization liquid so that the particles in the polymerization liquid have a particle size suitable for the toner. The present invention relates to a method for producing an electrophotographic toner characterized by the following.

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

During this emulsification and dispersion, one colorant and/or magnetic powder and an oil-soluble polymerization initiator or a water-soluble polymerization initiator less than the same weight as the oil-soluble polymerization initiator are present.

Other anti-offset agents.

A toner property improver such as a charge control agent, a fluidity improver, a cleanability improver, a stabilizer for assisting emulsification and dispersion, and a chain transfer agent may be appropriately present.

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 at the same time, or the polymerizable monomer is added to the aqueous medium in which the emulsifier is dissolved. However, they may be mixed by stirring.

As the polymerization initiator, an oil-soluble polymerization initiator is used.
Further, an oil-soluble polymerization initiator and a water-soluble polymerization initiator whose weight is less than the same weight are used.

When a large amount of water-soluble polymerization initiator is used as a polymerization initiator, the resulting toner tends to become hygroscopic, and as a result, the toner tends to reduce the amount of triboelectric charge and cause image fogging in a high-humidity atmosphere. .

The polymerization initiator may be added after emulsification and dispersion, but oil-soluble polymerization initiators and water-soluble polymerization initiators should be dissolved in advance in the polymerizable monomer and in the aqueous medium before emulsification and dispersion. It is preferable to leave it there.

In order to improve dispersion in the resin, the colorant and/or magnetic powder is preferably used after being dissolved or dispersed in the polymerizable monomer in advance, rather than being added after the emulsification and dispersion. The same applies to toner property improvers used as necessary. Furthermore, stabilizers may be used as needed;

It may be added after the emulsification and dispersion, or it may be used after being dissolved in an aqueous medium in advance.

Stirring and mixing in the above-mentioned emulsification dispersion may be performed using an ordinary stirrer at a relatively high speed, but emulsification equipment such as a high-speed shear disperser, homogenizer, colloid mill, flow jet mixer, ultrasonic emulsifier, static mixer, etc. It is preferable to use. This also applies to the case where a colorant and/or magnetic powder and an optional toner property improver are dispersed in the dipolymerizable monomer.

Polymerization is carried out for 20 minutes after or while emulsifying and dispersing.
Preferably it is carried out at a temperature of -120°C.

In particular, it is preferable to conduct the reaction at a temperature of 50 to 90°C.

This polymerization is preferably carried out until the dipolymerization rate reaches 99% by weight or more, preferably 99.9% by weight or more. The lower the polymerization rate and the higher the amount of residual monomer, the better the characteristics of the toner.

In particular, storage stability tends to be poor.

The weight average molecular weight of the polymer obtained by dipolymerization is preferably at least so, o o o.

If the molecular weight is too low, cleaning properties and blocking resistance tend to deteriorate.

Furthermore, the obtained polymer has a glass transition point of 30 to 90°C.
It is preferable that it is, and 50-80 degreeC is preferable to 415F. If the glass transition point is too low, blocking resistance tends to decrease, and if it is too high, fixing ability tends to decrease. The glass transition point can be adjusted mainly by selecting the polymerizable monomer to be used.

Such polymerization results in particles of about 3 μm or less.

Next, materials used for monopolymerization will be explained.

Examples of the polymerizable monomer include styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene,
p-ethylstyrene, 4-dimethylstyrene, p-
n-butylstyrene, p-tert-butylstyrene,
pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene,
p-n-dodecylstyrene, n-methoxystyrene, p
-Phenylstyrene, p-chlorostyrene, 3.4
- Styrene and its derivatives such as dichlorostyrene, ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, isobutylene, and vinyl chloride.

Vinyl halides such as vinylidene chloride, vinyl bromide, vinyl fluoride, vinyl esters such as vinyl acetate, vinyl propionate, vinyl penzoate, vinyl butyrate, methyl acrylate, ethyl acrylate, n-butyl acrylate, Inbutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, methyl α-chloroacrylate, methyl methacrylate.

Ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate.

α-methylene such as n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylamine ethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, etc. Aliphatic monocarboxylic acid esters, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, 2-hydroxyethyl acrylate, 2-hydroxyglobyl acrylate.

Acrylic acid or methacrylic acid derivatives such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and in some cases acrylic acid.

Methacrylic acid, maleic acid, fumaric acid, etc. can also be used. In addition, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl methyl ketone, vinyl hexyl ketone, methyl isopropyl benyl ketone, N-buerch pc, -l, N-vinyl carbazole, N-vinylindole.

N-vinyl compounds such as N-vinylpyrrolidone.

Vinylnaphthalene salts and the like can be used alone or in combination of two or more. Among these polymerizable monomers, styrene or styrene derivatives are used in an amount of 40 to 100% by weight.
The toner has excellent fixing properties when copied onto paper using an electrophotographic copying device.

Further, as the polymerizable monomer of the present invention, a compound having two or more polymerizable double bonds that can serve as a crosslinking agent can also be used in part. For example, divinylbenzene.

Aromatic divinyl compounds such as divinylnaphthalene and their derivatives; diethylene carboxylic acid esters such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol diacrylate, trimethylolpropane triacrylate; Divinyl compounds such as vinyl ether and divinyl sulfate, and compounds having three or more vinyl groups can be used alone or as a mixture. The amount of the crosslinking agent used is preferably 0 to 20% by weight, particularly preferably 0 to 5% by weight, based on the total amount of polymerizable monomers.

The aqueous medium used for emulsification and dispersion is mainly water, but depending on the case, a water-soluble organic solvent such as methanol, ethanol, methylcellosolve, butylcellosolve, etc. may be used in combination with water.

The water-soluble organic solvent is preferably 10% by weight or less based on water. What is the ratio of the above polymerizable monomer to the aqueous medium?

The weight ratio of the former/latter is preferably 40/60 to 90/10. If this ratio is too small, emulsification and dispersion will be too busy, and if this ratio is too large, the yield will decrease.

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

Examples of anionic surfactants include fatty acid salts such as sodium oleate and potassium castor oil, alkyl sulfate ester salts 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.

Examples of nonionic surfactants include polyoxyethylene alkyl ether, polyoxyethylene alkylphenol ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxine rubitan fatty acid ester, polyoxyethylene alkylamine, glycerin, fatty acid ester, and oxyethylene fatty acid ester. Examples include oxypropylene block polymers.

Examples of the cationic surfactant include alkylamine salts such as laurylamine acetate and stearylamine 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 0.01 to 1 per dipolymerizable monomer.
O is preferably 0.5 to 5% by weight, particularly preferably 0.5 to 5% by weight. If the amount of emulsifier used is too small, stable emulsification and dispersion will be difficult and busy, and if it is too large, the resulting toner will have poor moisture resistance.

Stabilizers include polyvinyl alcohol, starch,
Water-soluble polymers such as methyl cellulose, carboxymethyl cellulose, hydroxyethyl cellulose, 4+7 sodium acrylate, and polysodium methacrylate are preferably used in an amount of 0 to 1 weight per polymerizable monomer.

Examples of oil-soluble polymerization initiators include organic peroxides such as benzoyl peroxide and t-butyl perbenzoate, and azobis-based compounds such as azobisisobutyronitrile and azobisisobutylvaleronitrile. Agents include persulfates such as potassium persulfate and ammonium persulfate.

Hydrogen peroxide, 44'-azobiscyanovaleric acid, 42'-azobis(2-amidinopropane) dihydrochloride, t-butyl hydroperoxide, cumene hydroperoxide, etc. can be used.

The above water-soluble polymerization initiator may be used in combination with a reducing agent. As the reducing agent, there are commonly known ones such as sodium metabisulfite and ferrous chloride. Although it is not necessary to use a reducing agent.

When used, it is preferably used in an amount equal to or less than the amount of the water-soluble polymerization initiator.

The polymerization initiator is preferably used in an amount of 0.01 to 10% by weight per polymerizable monomer, preferably 1% KO11 to 5% by weight.

Examples of chain transfer agents include flukyl mercaptans such as t-dodecyl mercaptan, lower alkyl xanthogens such as diisopropyl xanthogen, carbon tetrachloride, carbon tetrabromide, etc. 0 to 2% by weight based on the polymerizable monomer. Preferably used.

Coloring agents preferably used in the present invention include:

Pigments or dyes such as various carbon blacks, nigrosine dyes (C,I, m50415
), 7 Nirinpuru (c, 1.&s O40s)
.

Calfoil Blue (C, I, & azoec Blu
e 3 L chrome elet −(C, 1, Nl 1
4090), Ur) Lamarin Blue (C, I, 8
177103), Te:s-Ho7 Oil Red (C
, I, Arashi 26105), Orient Oil Red $33
0 (C, I, Na60505), *Norif Yellow (C
, 1, m47005), 1fV7 blue chloride (C
,1,Na52015)t7riacyaniyblue(
C, I, & 74160), -v Laka () Green Off Sarate (C, 1, Na 42000) 5 Black (C, 1, Na 77266), Oil Black, Azo Oil Black These colorants can be used alone or in a mixture. Although any amount of these colorants can be used, in order to obtain the required concentration and for economical reasons, approximately 1 to 1 30% by weight, preferably 5-1
It is used in such a proportion that it weighs 5:96.

The pigment or dye may be subjected to various treatments for the purpose of increasing its dispersibility in the reaction system or in the toner of the present invention.

The treatment includes, for example, nigrosine dye (C, I).

There is a treatment of Na50415) using an organic acid such as stearic acid or maleic acid.

Among these colorants, particularly preferred for the toner of the present invention are various carbon blacks, such as furnace black, channel plaque, thermal black, acetylene black, lamp black, and the like. Furthermore, the carbon black may be surface-treated. As for surface treatment.

Examples include oxidation treatment using various oxidizing agents such as oxygen, ozone, and nitric acid, and surface adsorption treatment with organic acid esters such as dibutyl phthalate and dioctyl phthalate.

When using carbon black as a colorant, it is preferred to use grafted carbon black. What is grafted carbon black?

It is obtained by polymerizing the above polymerizable monomers in the presence of carbon black by a method such as bulk polymerization or solution polymerization. The polymer component of grafted carbon black is
It is preferably less than 50 parts by weight, especially less than 30 parts by weight per two grafted car pumps. Grafted carbon black is preferred because it has excellent dispersion stability during emulsion polymerization, but if the dipolymer acid content is too large, the viscosity tends to become too high when dispersed in the polymerizable monomer, and workability is reduced. descend. The amount of grafted carbon black used is preferably determined by the amount of carbon black component.

Magnetic powder is used when manufacturing magnetic toner.

This can also serve as a coloring agent. Preferred magnetic powders include oxides or compounds of iron such as magnetite or ferrite, or ferromagnetic elements such as nickel and cobalt. These magnetic powders are preferably powders with a particle size of 0.01 to 3 μm, and the surface of the magnetic powder is resin.

It may be treated with a titanium coupling agent, a silane coupling agent, a higher fatty acid metal salt, or the like. These magnetic substances can be contained in an amount of 20 to 80% by weight, preferably 35 to 70% by weight, based on the toner. Less than this amount may be used as a second colorant.

An offset inhibitor is used as necessary. The anti-offset agent is present in the system in various forms during polymerization and can be incorporated into the toner product. Alternatively, the anti-offset agent can be added later to the toner of the present invention in which no anti-offset agent is present.

Various natural waxes such as carnauba wax, hydrogenated castor oil, and low molecular weight olefin polymers can be used as the anti-offset agent in the present invention, and preferably low molecular weight olefin polymers are used. As this low molecular weight olefin polymer, a low molecular weight polymer of olefin or a copolymer of an olefin and a monomer other than olefin is used. Here, the olefins include ethylene, propylene, butene-1, etc., and the monomers other than siaolefins include acrylic esters, methacrylic esters, and the like. Examples of this low molecular weight olefin polymer include polyalkylene described in JP-A-55-153944, JP-A-50-936;
This can be achieved by using the low molecular weight olefin copolymer described in Japanese Patent No. 47.

The molecular weight of the low molecular weight olefin polymer of the present invention may be within the concept of low molecular weight in ordinary polymer compounds, but generally the weight average molecular weight (Mw) is 1,000.
0~45,000. Preferably 4000-6. OOO
belongs to.

The low molecular weight polyolefin polymer of the present invention has a softening point of 10
It is preferable to have an IC of 0 to 180°C, particularly an IC of 130 to 160°C.

There is no particular limit to the amount of the low molecular weight olefin polymer that can be used in the present invention, but it is preferably in the range of 0 to 30% by weight based on the weight of the toner.

Preferably it is used in an amount of 1 to 30% by weight. If the amount of the low molecular weight olefin polymer is too small, the offset effect due to its addition will not be exhibited, and if it exceeds 30% by weight, gelation may occur during the polymerization reaction.

Furthermore, a fluidity improver, a cleaning performance improver, etc. can be used as necessary. Although they can be present in the double polymerization reaction system and trapped in the product toner, they are preferably externally added to the product toner afterwards. The content of each of these is preferably 0% to 3% by weight based on the toner of the present invention. Fluidity improvers include silane,
Titanium.

Oxides of aluminum, calcium, magnesium, and magnesium, or those obtained by hydrophobizing the above oxides with a titanium coupling agent or a silane coupling agent, are suitable. Cleanability improvers include zinc stearate, lithium stearate, and lauric acid. These include metal salts of higher fatty acids such as magnesium or aromatic acid esters such as pentaerythritol benzoate.

In the present invention, by selecting the dipolymerizable monomer and the colorant, the charge amount and charge polarity of the product toner can be freely adjusted. A charge control agent can also be used in combination with the colorant in the toner.

Charge control agents preferably used in the present invention include azo dyes such as Subiron Black TRH and Subiron Black TPH (Hodogaya Chemical), p-fluorobenzoic acid, p-nitrobenzoic acid, and 44-di-t-butyl Examples include aromatic acid derivatives such as salicylic acid, tin compounds such as dibutyl-tin oxide, and dioctyl-tin oxide.

These are preferably used in an amount of 0 to 5% by weight based on one polymerizable monomer.

In the present invention, after the main resin component is produced by double polymerization, a coagulant is added to the obtained polymerization liquid (particle dispersion) to coagulate the particles. By appropriately aggregating the particles in the polymerization solution, a resin suitable for toner having an average particle size larger than the particles in the polymerization solution, having an incomplete spherical shape, and requiring no pulverization can be obtained. I can do it.

Here, the particle size distribution of the aggregated particles is 1-Zo.

It is preferably adjusted to 9% so that it becomes 1 g μm.

It is preferable to adjust the VC to 3 to 70 μm.

It is most preferable to adjust the thickness so that the main component is one having a diameter of 5 to 25 μm. The average particle size is preferably adjusted to 9 to 15 μm. For the purpose of adjustment as described above, it is preferable to use the coagulant in an amount of 0.1 to 5 times, preferably 0.3 to 3 times, the weight of the emulsifier in the 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 become too large.

Since incompletely spherical toner particles are obtained through this coagulation step, the toner particles have excellent cleaning properties. Moreover, since the emulsifier is also removed by this coagulation step, blocking resistance and charging stability are also improved.

In this coagulation step, mixing of the polymerization liquid and the coagulant can be carried out by a method such as dropping the polymerization liquid little by little into the aqueous coagulant solution while stirring, or mixing the aqueous coagulant solution and the polymerization liquid at a fixed ratio. .

The temperature in this coagulation step is not particularly limited, but is preferably from room temperature to 150°C, particularly preferably at a temperature equal to or higher than the softening point of the main resin component.

If the coagulation is carried out at a temperature below the softening point, it is particularly preferred to subsequently heat the coagulation liquid to a temperature above the softening point of the polymer. This heat treatment increases the bulk density of the main resin component particles and makes them moisture resistant.

Offset resistance and durability are improved.

It is also possible to add a large amount of coagulant to the polymerization liquid in the coagulation process to obtain large coagulates, which are then pulverized to a particle size suitable for toner. Although this method has the effect of uniformly dispersing the additives in the resin, it has a shape similar to that of the pulverized toner compared to the toner of the present invention due to the pulverization process, resulting in inferior cleaning properties and toner fluidity. .

On the other hand, in the present invention, the particles obtained by coagulation can be made into a toner as they are or only by being classified into two, and the shape of the toner particles can be changed.

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

Examples of coagulants 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, and the like. 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 combination of these and an inorganic acid. These coagulants are preferably used as a 0.1 to 10% by weight aqueous solution, particularly KO01 to 5% by weight aqueous solution.

After coagulation, toner particles can be obtained by centrifugal dehydration, further washing, drying and, if necessary, classification.

Here, washing is preferable in order to completely remove the emulsifier attached to the two particles, and as a result, along with the above-mentioned coagulation,
Charging stability and blocking properties can be improved.

Washing is preferably carried out with warm water of 40 to 100°C.

Note that the post-solidification heat treatment described above may be inserted during the washing process or between two or more washing processes.

The toners obtained according to the present invention can be used in various development processes, such as the cascade development method described in U.S. Pat. No. 2,61 &552, the magnetic brush method described in U.S. Pat. .221,7
Powder processing method described in US Pat. No. 76, Touchdown development method described in US Patent No. λ166.432,
The so-called jumping method described in JP-A-55-18656, the so-called microtoning method using a magnetic toner produced by a pulverization method as a carrier, and the so-called Vivo 2 method in which the necessary toner charge is obtained by frictional charging of magnetic toners. -Can be used in magnetic toner methods, etc.

First 2 The toner obtained by the present invention can be used in various fixing methods 2
For example, oil-less and oil coated heat roll methods, flash methods, open methods and pressure fixing methods can be used.

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, two examples of the present invention will be shown. Hereinafter, * means weight %.

Example 1 (1) Emulsification dispersion and production of polymerization liquid 3I! Craft carbon (Craft Carbon GP-E-2 manufactured by Ryoyu Kogyo ■) 1009 (
C polymerizable monomers include styrene 4009° and butyl acrylate 1209°. azobisisobutyronitrile 129 and t-dodecylmercaptan o, ag as a chain transfer agent,
The mixture was mixed and dispersed using a high-speed shearing disperser (manufactured by Tokushu Kika Kogyo ■, TK Homomixer) at 3000 cp and m for 30 minutes.

Next, ion exchange water 13009 was added to this carbon dispersion.
As an emulsifier, the anionic surfactant Dodecylbenzenesulfone Sodium 129, the nonionic surfactant Noniball PR-68 (Sanyo (tJ Industries ■Oxypropylene-oxyethylene block polymer) ag,
Add an aqueous solution containing 3 g of Noigen EA170 (polyoxyethylene glycol nonylphenyl ether manufactured by Daiichi Kogyo Seiyaku ■) and further dissolve with a high-speed shear dispersion machine (T, Ni, Homomixer, manufactured by Tokushu Kika Kogyo ■). 30 at
Emulsification was carried out for a minute to obtain a black pre-emulsion.

Next, the black pre-emulsion was transferred to a 31!4 separable flask equipped with a stirrer, nitrogen inlet, thermometer, and condenser, and the flask was polymerized at 80°C for 5 hours under a nitrogen stream, and then cooled. 1 polymerization solution was obtained. The polymerization rate at this time was 99.5 or more. The molecular weight of the dipolymer was measured by gel chromatography using a standard polystyrene calibration curve, and the weight average molecular weight (
Mw) go, ooo, number average molecular weight (Mn) 2 Fh
It was OOO.

(2) Solidification process/final process Above polymerization liquid 11! Mg5Oa heated to 30℃ 1
Chi aqueous solution 2I! The temperature of the aqueous solution was raised to 30°C while stirring thoroughly.
It was uniformly dropped and solidified over about 30 minutes while being maintained at .degree. The mixture was kept at this temperature for an additional 30 minutes and cooled to room temperature.

Next, this slurry was dehydrated using a centrifugal dehydrator, and then
Washing was performed three times with warm water at ℃. Then, 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 2 to 50 μm, with an average particle size of 14 μm. Further, the glass transition point (Tg) was measured with a differential scanning calorimeter and was found to be 73°C. This toner was further classified into 5 to 25 μm using a zigzag classifier (100MZR, manufactured by Alvin), and the yield was 859G compared to before classification.

In the Examples and Comparative Examples below, particle diameters and average particle diameters were measured using a Coulter counter, and glass transition points were measured using a differential scanning calorimeter.

Classification was performed using a zigzag classifier.

Examples 2 to 6 Polymerization liquid II obtained in Example 1! 9 to a coagulant aqueous solution (shown in Table IK) heated to the coagulation temperature shown in Table 1.
It was uniformly dropped and solidified in 0 minutes. During coagulation, the above coagulation temperature was maintained, and after the completion of dropping the polymerization liquid, the temperature was maintained at the same temperature as the above coagulation temperature for 30 minutes, and then cooled to room temperature. The obtained coagulated liquid (slurry) was dehydrated using a centrifugal dehydrator, and then washed three times with warm water at 50°C. Then, 30-35℃
The powder was dried in a dryer to obtain toner particles. The particle diameter, average particle diameter, yield of particles of 5 to 25 μm, and glass transition point of the main resin component of this toner particle are shown in Table IK together with the results of Example 1.

The classified toners obtained in Examples 1 to 6 were used.

A plain paper copying machine (manufactured by Konishi Roku Photo Industry ■, u-Bix 1600) using a commercially available insulating carrier was used.

The electrophotographic toner properties were tested. However, each toner contains hydrophobic silica (Nippon Aerosil) as a fluidity improver.
R-972) and zinc stearate were externally added to the above toner in an amount of 0.6% and 0.1%, respectively. The test results are shown in Table 1K.

Examples 7 to 9 Polymerization solution ll obtained in Example 1! And coagulation was carried out in the same manner as in Examples 1 to 6 using an aqueous coagulant solution (shown in Table 2) heated to the coagulation temperature shown in Table 2.

Transfer the obtained coagulated liquid (slurry) to an autoclave 2
It was heated for 30 minutes at the heat treatment temperature shown in Table 2.

Thereafter, it was cooled, dehydrated, washed with water, and dried in the same manner as in Examples 1 to 6 to obtain a toner.

Table 2 shows the particle size, average particle size, yield of particles of 5 to 25 μm, and electrophotographic properties tested in the same manner as Examples 1 to 6 of the obtained toner.

Table 2 Characteristic Comparative Example 1 (Production of toner by suspension polymerization) Styrene 70
g, butyl methacrylate 30g.

15 g of grafted carbon and 2 g of benzoyl peroxide were thoroughly kneaded using a high-speed shear dispersion machine (manufactured by Homo Mixer Tokushu Kika Kogyo ■), 500 g of tricalcium phosphate 1-h aqueous solution was added, and the mixture was further kneaded for 3000 r, l using a homo mixer.
), m for 30 minutes.

This dispersion was transferred to a flask and subjected to suspension polymerization at 80°C for 7 hours. The polymerization rate was 99% or more. This polymer was dehydrated, washed with an aqueous hydrochloric acid solution having a pH of 2 or less, and dried to obtain a toner. The Mw of the resin in this toner is 110,000. Mn was 50,000.

Comparative Example 2 (Production of toner by spray drying after emulsion polymerization) Except for Example 1, in which 12 g of ammonium persulfate was dissolved in ion-exchanged water together with an emulsifier instead of azobisisobutyronitrile 129. A toner was obtained by spray drying an emulsion polymerization solution obtained according to (1) of Example 1 at a temperature of 110°C.

Comparative Example 3 (pulverization method) Styrene/butyl methacrylate = 70/30 (weight ratio) 2 molecular weight Mw 70.
000 and Mn 30. A polymer of OOO was prepared, and toluene was removed by desolvation under reduced pressure to produce a white solid.

This polymer 1.0009 was kneaded with carbon black 509, 10 g of copper phthalocyanine, and 20 g of low molecular weight polypropylene (Viscol 550P, trade name of Sanyo Chemical Industries, Ltd.) using two rolls, and pulverized using a jet mill to obtain a toner.

Particle size and average particle size of toners obtained in Comparative Examples 1 to 3, 5
Table 3 shows the yield of ~25 μm particles, the glass transition temperature of the main resin component, and the electrophotographic properties tested in the same manner as Examples 1 to 6.
Shown below.

Table 3 Properties The electrophotographic properties of Examples 1 to 9 and Comparative Examples 1 to 3 were evaluated as follows.

(a) Resolution: Copies were made on plain paper using Electrophotography Society Test Chart Stone 1 and the respective developers. We compared and evaluated whether the copied images could be read in detail.

(b) Image density: Judgment was made by measuring the density of the black part of the copied paper with a densitometer in the same manner as the resolution.

Gradation: Evaluated in the same manner as the resolution using the 11-level shading section in the center of the test chart.

(C) Cleanability: Continuous copying was carried out using a copying machine using the respective prepared developers at a temperature of 30° C. and a humidity of 801 RH.

The process leading up to the occurrence of cleaning failure The evaluation was based on the number of pieces.

(dl Blocking property: Examples 1 to 14. The toners prepared in Comparative Examples 1 to 3 were heated at 50°C.

Leave it for 72 hours at a humidity of 95 degrees. Determine if the player is blocking. Fixed.

◎: Very good ○: Excellent Δ2 slightly inferior ×: Inferior It was evaluated as

(e) Charge stability: Each prepared developer was stirred in a copying machine, the amount of charge was measured at regular intervals, and judgment was made based on the change in the amount of charge.

◎: Very good ○: Excellent Δ: Slightly inferior X: Inferior It was evaluated as

(Effects of the Invention) According to the present invention, by utilizing the double polymerization method, resolution 2 image density 2
It is possible to obtain an electrophotographic toner that is suitable for dry development and has excellent gradation properties, particularly cleaning properties, charging stability, and blocking properties.

Claims (1)

[Claims] 1. Polymerizable monomers, colorants and/or magnetic powders, and oil-soluble polymerization initiators or oil-soluble polymerization initiators and less than the same weight of water-soluble polymerization initiators as emulsifiers. An electronic device characterized by emulsifying and dispersing and polymerizing in the presence of a toner to produce a main resin component, and coagulating the obtained polymerization solution so that the particles in the polymerization solution have a particle size suitable for toner. Method of manufacturing photographic toner. 2. The method for producing an electrophotographic toner according to claim 1, wherein during coagulation, the coagulant is used in an amount of 0.1 to 5 times the weight of the emulsifier in the polymerization solution. 3. The method for producing an electrophotographic toner according to claim 1 or 2, wherein at least one compound selected from inorganic acids, organic acids, and water-soluble metal salts thereof is used as a coagulant during coagulation. .