JPH0193748A - Production of toner for electrophotography - Google Patents

Abstract

PURPOSE:To improve the durability, cleanability and electrostatic charge stability of a toner by adhering a colorant, etc., to the surfaces of polymer particles obtd. by emulsion polymn. and by embedding and/or fixing the colorant, etc., in the particles by a mechanical means. CONSTITUTION:A polymerizable monomer such as styrene (deriv.) or (meth) acrylic acid (deriv.) is subjected to emulsion polymn., salting out, dehydration, washing and drying to obtain polymer particles (A). The particle A are mixed with a colorant and/or magnetic powder and further mixed with additives such as an offsetting inhibitor, an electrostatic charge controller and a flowability improver as required. After the colorant, etc., are adhered to the surfaces of the particles A, the particles A are put in a desired mechanical means and the colorant, etc., are embedded and/or fixed in the particles A by impact force or compressive force produced by the collision of the particles A with members such as the inner wall, agitating blades and metal balls and the collision of the particles A with one another.

Description

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

(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.

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 developed image to the transfer material. 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. However, a two-component developer is one that obtains toner of opposite polarity to the electrostatic charge image necessary 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 toner particles or friction with other members in the developing device.

Conventionally, toners for such dry developers have been prepared by melting and kneading colorants such as carbon black and/or magnetic powders such as magnetite into a hot OT plastic resin to form a dispersion using a suitable trowel. The toner has been manufactured by a method in which the dispersion is pulverized to a desired particle size by mechanically applying an impact force using a pulverizing device, and if necessary, it is further classified to form a toner (see below).

This method is called the crushing method).

Such methods not only require a large amount of energy for melt-kneading and grinding.

The produced toner necessarily has a number of drawbacks.

In particular, if a desirable resin is used in the melt mixing process and the pulverization process, for example, if a resin that easily melts is used, problems such as aggregation (blocking) during toner storage and capri caused by toner filming on the photoconductor may occur. Furthermore, if a pulverizable resin is used, it will be pulverized into fine toner in the developing device, resulting in image capri and dirt inside the machine.

In addition, the colorant dispersed in the resin appears on the surface of the crushed toner, which causes a decrease in the number of triboelectric charging needles in high humidity conditions and the dropout of the colorant in the developing machine.
This causes undesirable phenomena such as contamination of the carrier surface and contamination of the photoreceptor surface.

As a manufacturing method other than the crushing method, a method is known in which fine particles such as a colorant are fixed by applying an impact force to the surface of perfectly spherical particles obtained by suspension polymerization or the like.

(Problems to be Solved by the Invention) The toner particles obtained by the above method have poor cleaning properties because they are perfectly spherical. Since the suspending agent remains on the toner particles, charging stability and blocking resistance are reduced.

Furthermore, coloring agents, etc. are distributed only on the particle surface.

It has drawbacks such as wide charge amount distribution and increased spent amount.

The present invention solves these problems in the conventional toner manufacturing method, and is capable of producing two image densities.

Excellent resolution and gradation, especially durability.

The present invention provides a method for producing an electrophotographic toner that is suitable for dry development and has excellent cleaning properties, charging stability, and anti-blocking properties.

(Means for Solving the Problems) The present invention applies a salting-out operation to an emulsion polymerization solution obtained by emulsion polymerization of a 9-polymerizable monomer, and a 9-coloring agent and/or Mixing magnetic powder and adhering it to the surface of the polymer particles; 1 Applying impact force or compressive force by mechanical means; 1 embedding and/or fixing the colorant and/or magnetic powder in the polymer particles; The present invention relates to a method for producing an electrophotographic toner characterized by the following.

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

During this emulsion polymerization, 9 polymerization initiators are present.

As a method for emulsifying and dispersing the polymerizable monomer in an aqueous medium, the dipolymerizable 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.

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. Moreover, an oil-soluble polymerization initiator can also be used, and in this case, it is preferable to dissolve it in the polymerizable monomer in advance. Depending on the case, it is also possible to use both together.

Emulsion polymerization is preferably carried out at a temperature of 20 to 120°C, particularly preferably 50 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. When the polymerization rate is low and the amount of residual monomer is large, toner properties, especially storage stability, tend to be poor.

The polymer obtained by emulsion polymerization preferably has a weight average molecular weight of 50,000 or more.

If the molecular weight becomes too small, cleaning properties and blocking resistance tend to deteriorate.

Furthermore, the obtained polymer has a glass transition point of 30 to 90°C.
The temperature is preferably 9% and 5θ to 80°C. 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.

By such emulsion polymerization, particles having a particle diameter of about 0.5 μm or less can be obtained.

Next, materials used for emulsion polymerization will be explained.

Examples of the polymerizable monomers include styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, p-
Ethylstyrene, λ4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n
-hexylstyrene, p-n-octylstyrene, p-
n-nonylstyrene, p-n-f silstyrene, p-n
- Styrene and its derivatives such as dodecylstyrene, n-methoxystyrene, p-phenylstyrene, p-chlorostyrene, and he4-dichlorostyrene, ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and inobutylene, vinyl chloride .

Vinyl halides such as vinylidene chloride, vinyl bromide, vinyl fluoride, vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, vinyl butyrate, methyl acrylate, ethyl acrylate, n-butyl acrylate, acrylic isobutyl 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, cR-2 ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl acrylate, dimethylaminoethyl methacrylate, diethylaminoethyl acrylate, diethylaminoethyl methacrylate, etc. Aliphatic monocarboxylic acid esters, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, acrylic I! 1!2 Hydroxyethyl, 2-hydroxypropyl 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, and vinyl isobutyl ether, vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and methyl isopropenyl ketone, N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, N-vinyl compounds such as N-vinylpyrrolidone and vinylnaphthalene salts can be used alone or in combination of two or more. Among these polymerizable monomers, it is preferable to use styrene or a styrene derivative in an amount of 40 to 100% by weight, since 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 triacrylate, trimethylolpropane triacrylate; vinyl ether,
Divinyl compounds such as divinyl sulfite 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 in emulsion polymerization is mainly water. The ratio of the polymerizable monomer to the aqueous medium is preferably 40/60 to 90/10 in weight ratio of aqueous medium/polymerizable monomer. If this ratio is too small, emulsion polymerization will be difficult, and if this ratio is too large, the yield will 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 a positively chargeable toner, it is preferable to use a cationic surfactant. 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 ester salts such as sodium lauryl sulfate and ammonium uryl sulfate, alkylbenzene sulfonates such as sodium dodecylbenzenesulfonate, and flukylnaphthalene. Examples include sulfonates, dialkyl sulfosuccinates, alkyl phosphate ester salts, naphthalene sulfonic acid formalin condensates, and polyoxyethylene alkyl sulfate ester salts.

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 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 polymerizable monomer.
0% by weight is preferred, particularly 0.5-5% by weight. If the amount of emulsifier used is too small, stable emulsion polymerization will be difficult, and if it is too large, the resulting toner will have poor moisture resistance.

Stabilizers include polyvinyl alcohol, starch,
Water-soluble polymers such as methylcellulose, carboxymethylcellulose, and hydroxyethylcellulose are preferably used in an amount of 0 to 1% by weight based on the 9-polymerizable monomer.

Examples of water-soluble polymerization initiators that can be used in the present invention include persulfates such as potassium persulfate and ammonium persulfate, hydrogen persulfide, 4,4'-azopiscyanovaleric acid, and 2,2'-azobis. (2-amidinopropane)
Dihydrochloride, t-butylhydroberoxide, cumene hydroperoxide, etc. can be used. Particularly when persulfate is used, sulfate anion radicals (804 radicals are present on the surface of the hepatoma as the initiation active site, and the particles are stabilized by the hydrophilic group of the 5O4 group and the electrostatic charge, resulting in a relatively uniform particle size. It is easy to obtain an emulsion having .

The amount used is preferably 0.01 to 10% by weight based on the polymerizable monomer, particularly preferably 0.1 to 5% by weight.

If the amount of polymerization initiator is too small, the polymerizable monomer will not be completely polymerized, and residual amounts will remain in the toner, which will deteriorate the properties of the toner.

As a polymerization initiator, benzoyl peroxide, t-
Peroxides such as butyl perbenzoate.

Oil-soluble polymerization initiators such as azo compounds such as azobisisobutyronitrile and azobisisobutylvaleronitrile can also be used. Further, these initiators may be used in combination.

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 preferable to use it in an amount equal to or less than that of the water-soluble polymerization initiator.

Chain transfer agents include alkyl mercaptans such as t-dodecyl mercaptan, lower alkyl xanthogens such as diisoprobyl xanthogen, carbon tetrachloride, carbon tetrabromide, etc. Preferably, it% is used.

In addition, it is also possible to carry out emulsion polymerization without using the usual emulsifier as described above, such as soap-free emulsion polymerization and soap-free emulsion polymerization. These emulsion polymerization methods include a method in which a water-soluble resin such as maleated polybutadiene is used as a base for a conventional emulsifier, and a method in which a prepolymer is synthesized using a water-soluble initiator and a monomer monomer is further added in the presence of the prepolymer. In addition, the polymerization method CH2=C(CH3)-C00(CHzCHzO
)nH.

CH3 0CH3 CH2=C(CH3) -COO(Cru)ssOsM(
However, M represents a method using a reactive emulsifier having a double bond such as (Na or NH4, n represents a natural number), and the like. Emulsion polymers obtained by these methods are preferred because they have little or no adverse effects from emulsifiers and have excellent electrophotographic properties.

In the present invention, after producing the main resin component by emulsion polymerization, a salting-out agent is added to the obtained emulsion polymerization solution to perform salting-out. Thereby, the particles in the emulsion polymerization solution are agglomerated to preferably have a particle size of 1 to 30 μm, particularly preferably 5 to 25 μm.

The average particle size is preferably adjusted to 9 to 15 μm. If the particle size is smaller than 1 μm, toner scattering will be large;
Furthermore, cleaning performance is reduced. When the particle size exceeds 30 μm, image quality characteristics such as resolution deteriorate. Note that the particle size may be adjusted to the above particle size by classifying after salting out.

For the above adjustment, the salting-out agent is preferably used in an amount of 0.1 to 5 times, particularly 0.3 to 3 times, the weight of the emulsifier in the emulsion polymerization solution. If the amount of the salting-out agent used is too small, the salting-out 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.

In this salting-out process, the emulsion polymerization liquid and the salting-out agent are mixed,
This can be carried out by dropping the emulsion polymerization liquid little by little into the salting-out agent aqueous solution while stirring, or by mixing the salting-out agent aqueous solution and the emulsion polymerization liquid at a constant ratio. In this salting-out step, the temperature is not particularly limited, but is preferably 109C to 150C, particularly preferably 40 to 90C.

Examples of salting-out agents include inorganic acids such as hydrochloric acid and sulfuric acid, organic acids such as formic acid and sigma acid, these acids and alkaline earth metals,
There are water-soluble metal salts made of aluminum, etc. These salting-out agents can be used alone or in combination, but preferred salting-out agents are magnesium sulfate, aluminum sulfate, barium chloride, magnesium chloride, calcium chloride, sodium chloride, and/or a combination of these and an inorganic acid. . These salting-out agents are 0.1 to 1.0% by weight aqueous solutions.

It is particularly preferable to use it as an aqueous solution of 0.1 to 5% by weight.

After salting out, it is dehydrated using a centrifugal dehydrator or the like, and preferably further washed with warm water 2 to 3 times.

Here, washing is preferable in order to completely remove the emulsifier attached to each particle, and in addition to the above-mentioned salting out,
Charging stability and blocking resistance can be improved. Washing is preferably carried out with warm water at a temperature of 40 to 60°C.

The obtained particles are preferably dried in a hot air dryer at 30 to 40°C to obtain monopolymer particles. The polymer particles are about 9, for example, the emulsion polymer fine particles are about 103 to 109
1. It is a solid agglomerated substance with an irregular shape.

Next, a method for producing toner particles from the obtained polymer particles will be described.

First, polymer particles are mixed with a colorant and/or magnetic powder, and if necessary, fine particles of a toner property improver (hereinafter referred to as fine particles).

These are collectively called additives).

Colorants preferably used in the present invention include:

Pigments or dyes such as various carbon blacks, nigrosine dyes (C,1,Nα5041
5), Aniline Blue (C, I, Ma50405).

Calco oil blue (C, 1, Nll azoec B
3).

Chrome Yellow (CI, &14090), Ultramarine Blue (C1, Oni 77103), Dubon Oil Red (C, LNI126105), Orient Oil Reddna 330 (C, 1, Nα60505), Quinoline Yellow (C1, 47005), Methylene Pur-
(CLNa52015)t Lid a
Cyanine blue (C, I, Nα74160), malachite green offsalate <a r, 42000),
Lamp black (C1, Na77266)t
O's Bengal (C, I, Nα45435), oil black, azo oil black, etc., and 9 other treatments 1. For example, nigrosine dyes treated with organic acids such as stearic acid and maleic acid.

Examples include those obtained by surface oxidation treatment of various carbon blacks with an oxidizing agent such as oxygen, ozone, or nitric acid, and those subjected to surface adsorption treatment of various carbon blacks with organic acid esters such as dibutyl phthalate and dioctyl phthalate.

Among these colorants, those particularly preferred for the toner according to the present invention include carbon blacks such as furnace black, channel black, thermal black, acetylene black, and lamp black, and carbon blacks subjected to the above-mentioned treatments. The colorant can be used in any amount, but in order to obtain the required concentration and from economic considerations, it is preferably used in the toner in an amount of 1 to 3.0% by weight, particularly preferably 2 to 15% by weight. be done.

Examples of the magnetic powder include oxides or compounds of iron such as magnetite or ferrite, or ferromagnetic elements such as nickel and cobalt. These magnetic powders are preferably in powder form with a particle size of 0.01 to 3 μm,
Further, the surface of the magnetic powder may be treated with a resin titanium coupling agent, a silane coupling agent, a higher fatty acid metal salt, or the like. These magnetic powders are 20~
It is used in an amount of 80 weight ft or 35 to 70% by weight. Incidentally, the coloring agent may be used in an amount less than this, or it may be used in combination with the 9 coloring agent.

When used together, the amount of the colorant may be less than 10% by weight based on the total toner components.

An anti-offset agent is used as a toner property improver.

Examples include charge control agents, fluidity improvers, and cleaning performance improvers.

Examples of anti-offset agents include various natural waxes,
Examples: Eva carnauba wax, hydrogenated castor oil or low molecular weight olefin polymers are used in the present invention, preferably low molecular weight olefin polymers are used. As the low molecular weight olefin polymer, olefin polymers and low molecular weight copolymers of olefins and monomers other than olefins are conveniently used. Here, the olefins include ethylene, propylene, butyl-1, etc.

Examples of monomers other than olefins include acrylic esters and methacrylic esters. Examples of this low molecular weight olefin polymer include 9, for example, JP-A-55-1539
Polyalkylene described in Publication No. 44, % opening 50-
A low molecular weight olefin copolymer described in Japanese Patent No. 93647 can be used.

The molecular weight of the low molecular weight olefin polymer of the present invention may be one that is included in the concept of low molecular weight in ordinary polymer compounds.
00-45,000. Preferably 4,000 to 6,000
belongs to.

The low molecular weight polyolefin polymer of the present invention has a softening point of 10
Those having a temperature of 0 to 180°C, particularly 130 to 160°C are preferred.

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 used in an amount of 0 to 30% by weight based on the weight of the toner. If the content of the low molecular weight olefin polymer exceeds 30% by weight, the fluidity and blocking resistance of the toner tend to be poor.

As a charge control agent, Subiron Black TRH is used.

Spiron black TPH (all manufactured by Hodogaya Chemical Industry)
Examples include azo dyes such as (manufactured by)), aromatic acid derivatives such as p-fluorobenzoic acid, p-nitrobenzoic acid, and 2,4-di-t-butylsalicylic acid, and tin compounds such as dibutyl-tin oxide and dioctyl-tin oxide. be able to.

The charge control agent is preferably used in an amount of 0 to 5 with respect to the main resin component.
Heavy! used in a loose manner.

Furthermore, a combination of fluidity improver and cleaning property improver can be used as necessary. The content of each of these is preferably 0 to 3% by weight based on the toner of the present invention.
used to become

Fluidity improvers include silane, titanium, aluminum, calcium, magnesium, and magnesium oxides, or those obtained by hydrophobizing the above oxides with a titanium coupling agent or a silane coupling agent.Cleanability improvers include .

These include metal salts of higher fatty acids such as zinc stearate, lithium stearate and magnesium laurate, or aromatic acid esters such as pentaerythritol benzoate.

The polymer particles and additives are mixed using a means such as stirring with a small stirrer, and as a result, on the surface of the bipolymer particles,
The additive is attached. This stirring time of 9 revolutions corresponds to 9 types of toner ingredient combinations.

It varies depending on the amount and is selected appropriately.

Subsequently, an impact or compressive force is applied by mechanical means to the polymer particles to which the additive is attached. Devices that apply impact force or compressive force by mechanical means include known mixers, ball mills, automatic mortars, and the like, as well as devices configured as shown below.

It has the effect of embedding and/or fixing.

Specifically, it is equipped with equipment components that rotate at high speed.

The particles collide here, and the hit receiver is bounced off and collides with the inner wall of the device, other fixed or rotating hitting members, etc., and is hit again, causing damage to other parts around the polymer particles. The fine particles of the toner component are buried and/or
Or, while being fixed, the particles are carried by a large amount of gas circulating preferably at high speed in the device and are again subjected to the above-mentioned blows, which are repeated many times in a short period of time to obtain toner particles. There are some configurations that can be mentioned. An apparatus having such a structure can apply a strong impact force many times in an extremely short period of time, so that toner particles with good characteristics can be obtained in a short period of time. The currently available equipment is Hypuridizer (product name, @Nara Kikai Seisaku Shinsei).
, Ongmil (trade name, manufactured by Hosokawa Micron ■), etc. Note that the device is not limited to these, and any device may be used as long as it can produce similar effects.

Here, the bipolymer particles are two particles, a stirring blade, and an inner wall.

Collision with equipment internal materials such as metal balls Due to the impact force or compressive force caused by collision of one particle with another, the additive that adheres to the surroundings is affected by the heat generated at the same time, and the additive adheres to the inside and surface of the polymer particle. buried and/or fixed. Furthermore, heating etc. may be performed as an auxiliary means.

Impact or compressive force applied by mechanical means.

To prevent the polymer particles obtained by salting out in the previous step from being crushed or melted and fused with other particles, and to prevent them from having an irregular shape after the salting out step. It must be added to the extent that the particles do not become perfectly spherical. - The impact force or compressive force must be applied in such a way that the embedding and/or fixation of fine particles of other toner components into the polymer particles is not incomplete due to insufficient impact force or compressive force.

The conditions for this differ depending on the components of the device 2 polymer particles used, other toner components, etc., and are appropriately determined for each.

It is preferable to use the device whose configuration was explained above (commercially available products include Hypuridizer, Ongmill, etc.) because it is easy to set these conditions and toner particles with particularly good characteristics can be obtained in a short time. .

The obtained particles can be used as a toner as they are, but if necessary, they may be classified using a known classifier or the like.

The toner 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. 2,618,552, the magnetic brush method described in U.S. Pat. No. 2,874,065, the Patent No. 2.221,
776, the touchdown development method described in U.S. Patent No. 3,166.432, the so-called jumping method described in JP-A-55-18656, and the pulverization method as a carrier. It can be used in the so-called microtoning method using the magnetic toner produced by the method and the so-called bipolar magnetic toner method in which the necessary toner charge is obtained by frictional charging of magnetic toners.

1. The toner obtained according to the present invention can be used in various fixing methods.
For example, so-called oil-less and oil-coated heat roll methods,
It can be used in flash method, open method, pressure fixing method, etc.

Furthermore, the toner of the present invention can be used in various cleaning methods 9, such as the so-called fur brush method and blade method.

(Example) Next, the present invention will be explained in detail based on this example.

The present invention is not limited to this.

Below, 9% means % by weight.

Example 1 [Emulsion polymerization] 5I! Styrene 7σOg in a stainless steel beaker.

Butyl methacrylate 3009. t-dodecyl mercaptan19. 2,000 g of ion-exchanged water, 209 g of sodium dodecylbenzenesulfonate, and 15 g of ammonium persulfate were added and mixed and dispersed at 3000 rpm for 30 minutes using a TK homomixer (manufactured by Tokushu Kika Kogyo ■) to obtain a pre-emulsion. Next.

Add this pre-emulsion to a stirring device and nitrogen inlet.

31 with thermometer and capacitor! Transfer the 4 pieces to a parapet flask and lower the temperature of the flask to 70°C under a nitrogen stream.
After polymerizing at ℃ for 5 hours, it was cooled.

Emulsion polymerization was obtained.

The polymerization rate at this time was 99.9% or more. When the molecular weight of the polymer was measured by gel permeation chromatography using a standard polystyrene calibration curve, the weight average molecular weight (Mw) was 110,000.
The number average molecular weight (Mn) was 43.000. or,
The glass transition point was measured with a differential scanning calorimeter and was 73°C.
Met.

[Production of polymer particles]

The above emulsion polymerization solution 11! MgSO4 heated to 40℃
2 tons of 0.2% aqueous solution! The mixture was thoroughly stirred and added dropwise over about 30 minutes to salt out. The mixture was kept at this temperature for an additional 30 minutes, and then cooled to room temperature. Next, this slurry was dehydrated using a centrifugal dehydrator, and then washed three times with warm water at 40°C.

Next, it was dried in a dryer at a temperature of 30 to 35°C to obtain 9 polymer particles.

When the particle size of the particles was measured using a Coulter counter, the particle size was 2 to 20 μm, with an average particle size of 11 μm.

[Manufacture of toner]

The above polymer particles 859. Carbon black Φ44 (manufactured by Mitsubishi Chemical Industries, Ltd.) 10s, oil black BY with glosine dye, Orient Chemical Industries, Ltd.) 3s, and low molecular weight polypropylene viscoel 660F (manufactured by Sanyo Chemical Industries, Ltd.)
2B was added to the 0M dizer of a hybridization system (Nara Kikai Seisaku Shin) and mixed and dispersed to form a state in which the additive i was attached to the surface of the 9 polymer particles. Next, using the same system's hyperdizer, the rotation speed was 7.00 Orp.
The toner was fixed by treating with m for 3 minutes to produce a toner.

Furthermore, this toner was classified into 5 to 25 μm using a zigzag classifier.

Comparative Example 1 (Example using pulverization method) Styrene/butyl methacrylate = 70/30 (weight ratio) 9 Molecular weight Mw 70.0 by solution polymerization using toluene as a solvent
00 and Mn 30,000 were prepared and desolventized under reduced pressure to remove toluene and produce a white solid.

This polymer ssog, carbon blackna 4
41009, oil black BY309, and low molecular weight polypropylene biscol 660P209 were mixed, melt-kneaded with two rolls, and pulverized with a jet mill to obtain a toner. Furthermore, it was classified into 5 to 25 μm using a zigzag classifier.

Comparative Example 2 (method using s-turbid polymer particles) Aqueous suspension polymerization of monomers with a blending ratio of styrene/butyl methacrylate = 70/30 (weight ratio) was carried out using tricalcium phosphate as a dispersant. ~25μm, average particle size 16μm9 molecules jiMw
Polymer particles of 90,000°Mn 45,000 were obtained. 85g of these dry particles, carbon black≠44 10
ge oil black BY39 and low molecular weight polypropylene viscoel 660P 2G were mixed for 10 minutes using a small stirrer to form a uniformly dispersed state.

This mixture was then stirred for 30 minutes in an automatic mortar ANM-200 to obtain a toner. Furthermore, this toner was classified into 5-25 μm particles using a zigzag classifier.

Characteristic test example 1. Regarding Comparative Example 1.2, electrophotographic toner properties were tested using a plain paper copying machine (5F755 manufactured by Sharp ■) using a commercially available conductive carrier. The results are shown in Table 1. However, for each toner.

Hydrophobic silica (Nippon Aerosil R) as a fluidity improver
-972) and zinc stearate were externally added to the above toner in amounts of 0.2% and 0.1%, respectively.

Table 1 Evaluation of two-component toner All evaluation tests for photographic properties were conducted as follows.

(a) Resolution 2 was copied onto plain paper using the Photo Society Test Chart Standard 1 and each developer was used. We compared and evaluated whether the copied images could be read in detail.

(b) Image density: 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 9.

(C) Gradation: Evaluated in the same way as the resolution using the 11-level gray area in the center of the test chart.

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

[e3 Blocking resistance: Examples 1 to 2. Comparative example 1
The toner prepared in steps 2 to 2 was left for 72 hours at 50''C and 95% humidity, and it was determined whether the toner was blocked or not, and evaluated based on the following criteria.

◎: Excellent ○: Excellent △: Slightly inferior It was determined based on the change and evaluated using the following criteria.

◎: Excellent ○: Excellent Δ: Slightly inferior ×: Inferior (g) Durability: Using a copying machine, the respective developers were tested at a temperature of 30°C and a relative humidity of 80%.
Continuous copying of o sheets was performed. The toner scattering that occurs at this time was investigated and judged based on the following evaluation.

◎: No toner scattering O: Some toner scattering Δ: A lot of toner scattering ×: A large amount of toner scattering Example 2 Using the same polymer particles as Example 1, the following was carried out. A magnetic toner was produced with the formulation shown.

These were added to the QM dizer of a hybridization system (made by Nara Kikai Seizo Shin) and mixed and dispersed to form a state in which the additive was attached to the surface of one polymer particle. Next, using the hybridizer of the same system, the number of revolutions was 10,000.
0 for about 5 minutes to produce a toner. Furthermore, this toner was classified into 5-25 μm particles using a zigzag classifier.

Comparative Example 3 A magnetic toner was produced using the same suspension polymerized resin as in Comparative Example 2 with the formulation shown below.

These were mixed for 10 minutes using a small stirrer to form a uniformly dispersed state, and this mixture was stirred for 30 minutes using an automatic mortar ANM-200 to obtain a toner.

Furthermore, this toner was classified into 5-25 μm particles using a zigzag classifier.

Characteristics Test The electrophotographic toner characteristics of Example 2 and Comparative Example 3 were tested using a commercially available plain paper copying machine (NP-200J, manufactured by Canon ■), and the results are shown in Table 2.

However, each toner contains hydrophobic silica (
Nippon Aerosil ■R, -972) and zinc stearate were externally added to the above toner in amounts of 0.5% and 0.2%, respectively.

Table 2 Evaluation of magnetic toner (effects of the invention) According to the method for producing an electrophotographic toner according to the present invention, a toner that is excellent in resolution, two image density, and one gradation property, as well as particularly excellent in cleaning performance and durability, is produced. can get. Furthermore,
In addition to the above characteristics, a toner having excellent charging stability and blocking resistance can be obtained.

, par Agent: Patent attorney Kunihiko Wakabayashi.

Claims (1)

[Scope of Claims] 1. Polymer particles obtained by salting out an emulsion polymerization solution obtained by emulsion polymerization of polymerizable monomers are mixed with a colorant and/or magnetic powder and polymerized. An electronic device characterized in that a coloring agent and/or magnetic powder is embedded and/or fixed in the polymer particles by adhering them to the surface of the combined particles and applying an impact force or compressive force by mechanical means. Method of manufacturing photographic toner. 2. The method for producing an electrophotographic toner according to claim 1, further comprising mixing a toner property improver with the colorant and/or magnetic powder.