JP2002148860A - Method of manufacturing polymerization process toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method of manufacturing polymerization process toners by which high improving density is stably maintained and which do not give rise to fogging or the like, stably yield high-quality images even under the environment of high temperature and high moisture and have durability. SOLUTION: This method of manufacturing the polymerization process toners consists in polymerizing a polymerizable monomer composition containing at least polymerizable monomers and coloring agents in a medium to form colored polymer particles, then filtering the colored polymer particles out of the medium, adding a cleaning liquid 14 to the filtered colored polymer particles 13 to reslurry the particles, filtering the colored polymer particles again out of the reslurry liquid and drying the refiltered colored polymer particles 17. The reslurry process step successively manufactures the reslurry liquid 15 by supplying and mixing the colored polymer particles 13 by a small amount each into and with the continuously or intermittently flowing cleaning liquid 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a polymerization toner used for an image forming method for developing an electrostatic latent image and a toner jet recording method.

[0002]

2. Description of the Related Art Conventionally, many methods have been known as electrophotography. In general, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means. The latent image is developed with a toner to form a visible image, the toner image is transferred to a transfer material such as paper as necessary, and then the toner image is fixed on the transfer material by heat, pressure, etc. Is what you get.

Various methods have been conventionally proposed as a method of developing with toner or a method of fixing a toner image.

Conventionally, toners used for these purposes are:
Generally, a colorant comprising a dye or a pigment is melt-kneaded in a thermoplastic resin, uniformly dispersed, then finely pulverized by a fine pulverizer, and the finely pulverized material is classified by a classifier to obtain a desired particle size. Has been manufactured.

[0005] Although this method can produce fairly good toners, it does have certain limitations, namely the choice of toner materials. For example, the resin colorant dispersion must be sufficiently brittle and capable of being comminuted on economically feasible manufacturing equipment. However, when the resin colorant dispersion is made brittle to satisfy these requirements, when the dispersion is actually finely pulverized at a high speed, the particle size range of the formed particles tends to be widened, and particularly, the fine particles are formed in a relatively large proportion. Is included in this.

Further, the toner obtained from such a highly brittle material is susceptible to further pulverization or powdering in a developing device such as a copying machine. Further, in this method, it is difficult to completely and uniformly disperse solid fine particles such as a colorant in a resin, and depending on the degree of the dispersion, an increase in fog at the time of image formation, a decrease in image density, color mixing or transparency. Great care must be taken in dispersing the colorant, as this can lead to poor properties. Further, exposure of the coloring agent to the fracture surface of the pulverized particles may cause a change in development characteristics.

On the other hand, in order to overcome the problems of the toner caused by these pulverization methods, Japanese Patent Publication Nos.
Various polymerization toners and production methods thereof have been proposed, including suspension polymerization toners disclosed in Japanese Patent Nos. 10799 and 51-14895 and the like. For example, in a suspension polymerization method toner, a polymerizable monomer, a colorant and a polymerization initiator, and further, if necessary, a crosslinking agent, a charge control agent, and other additives are uniformly dissolved or dispersed to prepare a monomer composition. After that, the monomer composition is dispersed in a medium containing a dispersion stabilizer, for example, an aqueous phase using a suitable stirrer, and simultaneously subjected to a polymerization reaction, and separated by filtration and dried to obtain a desired product. A toner particle having a particle size is obtained. In this method, since no pulverization step is included, the toner does not need to be brittle, a soft material can be used as the resin, and the colorant is not exposed on the particle surface, and uniform friction can be achieved. There is an advantage that a toner having chargeability can be obtained. Further, since the particle size distribution of the obtained toner is relatively sharp, even if the classification step is omitted or the classification is performed, the toner can be obtained in a high yield.

However, since the polymer toner directly generates toner particles in the medium, the surface of the toner is easily affected by the medium.

For example, when the medium is an aqueous medium, a polar resin having a high polarity and a charge control agent generally tend to be localized near the toner surface. As a result, compared with the pulverized toner, a very small amount of the charge control agent can impart uniform and high chargeability to the toner, but a highly polar material such as the charge control agent is a very small part, Some are dissolved in an aqueous medium. Therefore, great care must be taken in the step of filtering the toner particles from the medium after the completion of the polymerization reaction.

That is, it is important how to efficiently and uniformly clean the surface of each toner particle. That is,
If the surface of each toner particle is not uniformly washed, the charge distribution of the toner becomes broad, and in an environment where the toner is difficult to be charged, such as under high temperature and high humidity, problems such as a decrease in image density and fog occur. Easier to do.

[0011]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to solve the above-mentioned problems, to efficiently and uniformly clean the surface of each toner particle, and to form an image using the obtained toner. An object of the present invention is to provide a method for producing a polymerization toner which can stably maintain a high image density and obtain a toner having excellent image characteristics without generating fog.

It is a further object of the present invention to provide a method for producing a polymerization toner capable of stably obtaining a high-quality image even in a high-temperature and high-humidity environment and obtaining a durable toner.

[0013]

The above object is achieved by the present invention described below.

That is, according to the present invention, a polymerizable monomer composition containing at least a polymerizable monomer and a colorant is polymerized in a medium to form colored polymer particles, and then the polymer is colored from the medium. The polymer particles were separated by filtration, a washing solution was added to the filtered colored polymer particles, and the slurry was reslurried.The colored polymer particles were refiltered from the reslurried liquid, and the refiltered colored polymer particles were dried to obtain a polymerization method. A method for producing a toner, wherein the reslurry step is a step of successively producing a reslurry liquid by supplying and mixing a small amount of colored polymer particles in a continuous or intermittent washing liquid to produce a reslurry liquid. And a method for producing the same.

Further, according to the present invention, a polymerizable monomer composition containing at least a polymerizable monomer and a colorant is polymerized in a medium containing a dispersion stabilizer to form colored polymer particles. After that, an acid or alkali is added to the suspension containing the colored polymer particles to dissolve the dispersion stabilizer in the medium, the unwashed colored polymer particles are filtered from the medium, and the unwashed filtered A method for producing a polymerized toner by adding a washing liquid to the colored polymer particles and reslurrying, re-filtering the washed colored polymer particles from the re-slurried liquid, and drying the re-filtered washed colored polymer particles. Wherein the reslurry step is a step of supplying a small amount of unwashed colored polymer particles little by little into a continuous or intermittent washing liquid to produce a reslurry liquid, thereby producing a reslurry liquid sequentially. About the method.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in more detail with reference to preferred embodiments.

The present inventors have conducted intensive studies to solve the above-mentioned problems of the prior art. As a result, in order to efficiently and uniformly wash the surface of each toner particle, the colored resin particles were separated from a medium by filtration. It was found that the cleaning method had a significant effect.

The method for producing a polymerization toner according to the present invention is characterized in that at least a release agent, a colorant, a charge control agent,
Adding a polymerization initiator and other additives, dissolving or dispersing, and dispersing the monomer composition in an aqueous phase containing a dispersion stabilizer, and forming a droplet of the monomer composition into a desired liquid. A step of granulating until the size of the toner particles is obtained, a step of polymerizing the polymerizable monomer composition in a medium to generate toner particles, and after the completion of the reaction, adjusting the pH and adding a dispersion stabilizer. The method includes a step of dissolving, a step of filtering and washing the generated toner particles, and a step of drying the filtered and washed toner particles.

Preferred monomers used in the present invention include, specifically, styrene monomers such as styrene, o (m-, p-)-methylstyrene and m (p-)-ethylstyrene; Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, octyl (meth) acrylate, (meth)
Dodecyl acrylate, stearyl (meth) acrylate,
Behenyl (meth) acrylate, 2- (meth) acrylate
(Meth) acrylate monomers such as ethylhexyl, dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate; ene monomers such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile and acrylamide A dimer is preferably used. These can be used alone or generally in the published Polymer Handbook, 2nd edition III-P 139-192 (Jo).
hnWiley & Sons), and the monomers are appropriately mixed and used so that the theoretical glass transition temperature (Tg) thereof is 40 to 75 ° C. If the theoretical glass transition temperature is lower than 40 ° C., problems arise in terms of the storage stability of the toner and the durability stability of the developer. In this case, the color mixture of each color toner is insufficient and the color reproducibility is poor, and the transparency of the OHP image is remarkably reduced, which is not preferable from the viewpoint of high image quality.

The molecular weight of the shell resin is measured by GPC (gel permeation chromatography). As a specific GPC measurement method, the toner is extracted in advance with a toluene solvent using a Soxhlet extractor for 20 hours, and then the toluene is distilled off with a rotary evaporator. After adding an organic solvent that cannot be dissolved, for example, chloroform, and washing well, the solution dissolved in THF (tetrahydrofuran) was filtered through a solvent-resistant membrane filter having a pore diameter of 0.3 μm. 150C, column composition was A-801, 802, 80 manufactured by Showa Denko
3, 804, 805, 806, 807 can be linked and the molecular weight distribution can be measured using a standard polystyrene resin calibration curve.
The number average molecular weight (Mn) of the obtained resin component is 5000
An outer shell resin having a weight average molecular weight (Mw) and a number average molecular weight (Mn) of 2 to 100 is preferable for the present invention.

In the present invention, when a toner having a core / shell structure is produced, it is particularly preferable that a polar resin is further added to the outer shell resin in order to incorporate a substance having a low softening point.

As the polar resin used in the present invention, a copolymer of styrene and (meth) acrylic acid, a maleic acid copolymer, a saturated polyester resin, and an epoxy resin are preferably used. It is particularly preferable that the polar resin does not contain much unsaturated group in the molecule which can react with the outer shell resin or the monomer. If a polar resin having many unsaturated groups is contained, a cross-linking reaction occurs with the monomers forming the outer shell resin layer. Is disadvantageous and is not preferred.

In the present invention, an outermost shell resin layer may be further provided on the surface of the toner. The glass transition temperature of the outermost shell resin layer is preferably designed to be equal to or higher than the glass transition temperature of the outer shell resin layer in order to further improve blocking resistance, and it is preferable that the outermost shell resin layer is crosslinked so as not to impair fixability. . The outermost resin layer preferably contains a polar resin and a charge control agent for improving the chargeability.

The method for providing the outermost shell layer is not particularly limited, but examples thereof include the following method. 1. In the second half of the polymerization reaction or after the end, if necessary, a monomer in which a polar resin, a charge control agent, a cross-linking agent, etc. are dissolved and dispersed in the reaction system is added, the mixture is adsorbed on polymer particles, a polymerization initiator is added, and polymerization is performed. How to do. 2. If necessary, an emulsion polymerization particle or a soap-free polymerization particle composed of a monomer containing a polar resin, a charge control agent, a cross-linking agent, etc. is added to the reaction system, and aggregated on the surface of the polymerization particle.If necessary, heat or the like is used. How to stick. 3. A method in which emulsion polymerized particles or soap-free polymerized particles comprising a monomer containing a polar resin, a charge control agent, a cross-linking agent, and the like, if necessary, are dry-mechanically fixed to the toner particle surfaces.

As the coloring agent used in the present invention, carbon black, a magnetic substance, and those toned to black using the following yellow / magenta / cyan coloring agents are used.

Examples of the yellow colorant include condensed azo compounds, isoindolinone compounds, anthraquinone compounds,
Compounds represented by azo metal complexes, methine compounds and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 12, 13, 14, 15, 17, 6
2, 74, 83, 93, 94, 95, 109, 110,
111, 128, 129, 147, 168 and the like are preferably used.

Examples of the magenta colorant include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinones, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds and perylene compounds. Specifically, C.I.
I. Pigmentlets 2, 3, 5, 6, 7, 23, 4
8; 2, 48; 3, 48; 4, 57; 1, 81; 1, 1
22, 144, 146, 166, 169, 177, 18
4, 185, 202, 206, 220, 221, 254
Is particularly preferred.

As the cyan coloring agent, copper phthalocyanine compounds and derivatives thereof, anthraquinone compounds, basic dye lake compounds and the like can be used. Specifically, C.I. I.
Pigment Blue 1, 7, 15, 15: 1, 15: 2,
15; 3, 15: 4, 60, 62, 66 and the like can be particularly preferably used.

These colorants can be used alone or as a mixture or in the form of a solid solution.

In the case of a color toner, the colorant used in the present invention is selected from the viewpoints of hue angle, saturation, lightness, weather resistance, OHP transparency, and dispersibility in the toner. The colorant is used in an amount of 1 to 20 parts by mass per 100 parts by mass of the resin.

When a magnetic material is used as a black colorant, unlike the other colorants, 4 to 1 with respect to 100 parts by mass of the resin.
Used by adding 50 parts by mass.

The charge control agent used in the present invention includes:
Although a known toner can be used, in the case of a color toner, a charge control agent which is colorless, has a high toner charging speed, and can stably maintain a constant charge amount is particularly preferable. Specific compounds include metal compounds of salicylic acid, naphthoic acid, and dicarboxylic acid, polymer compounds having sulfonic acid and carboxylic acid in the side chain, boron compounds, urea compounds, silicon compounds, and carricks arenes as negative compounds. As the positive system, a quaternary ammonium salt, a high molecular compound having the quaternary ammonium salt in a side chain, a guanidine compound, an imidazole compound and the like are preferably used. The charge control agent is preferably used in an amount of 0.5 to 10 parts by mass based on 100 parts by mass of the resin.

Examples of the polymerization initiator used in the present invention include 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile,
1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-
Azo-based polymerization initiators such as dimethylvaleronitrile and azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-
A peroxide-based polymerization initiator such as dichlorobenzoyl peroxide and lauroyl peroxide is used.

The amount of the polymerization initiator varies depending on the desired degree of polymerization, but generally ranges from 0.5 to 2 with respect to the monomer.
0 mass% is added and used. Although the type of the initiator slightly varies depending on the polymerization method, it is used alone or in combination with reference to the 10-hour half-life temperature. Further, in order to control the degree of polymerization, a known crosslinking agent, chain transfer agent, polymerization inhibitor and the like can be further added and used.

In the toner production method of the present invention, it is preferable that the dispersion stabilizer used at the time of polymerization is an acid or alkali-soluble inorganic compound. Further, the inorganic compound is preferably a phosphoric acid compound. Examples of the phosphate compound include tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, and the like. It is preferable to use 0.2 to 10.0 parts by mass of these dispersion stabilizers with respect to 100 parts by mass of the polymerizable monomer.

As the dispersion stabilizer, a commercially available dispersion stabilizer may be used as it is. However, in order to obtain finely dispersed particles having a uniform particle size, the inorganic compound is dispersed under high-speed stirring in a dispersion medium. It can also be generated. For example, in the case of tricalcium phosphate, a dispersion stabilizer suitable for a suspension polymerization method can be obtained by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring. Also,
For miniaturization of these dispersion stabilizers, 0.001 to 0.1 parts by mass of a surfactant may be used in combination.

Specific examples of the surfactant include commercially available nonionic, anionic, and cationic surfactants, such as sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, and sodium oleate. , Sodium laurate, potassium stearate, calcium oleate and the like are preferably used.

The method for producing the polymerization toner of the present invention is specifically carried out as follows.

A releasing agent, a coloring agent, a charge controlling agent, a polymerization initiator and other additives composed of a low-softening substance are added to at least the polymerizable monomer, and are uniformly dissolved or dispersed by a homogenizer, an ultrasonic disperser or the like. The resulting monomer composition is dispersed in a medium such as water containing a dispersion stabilizer using a conventional stirrer, homomixer, homogenizer, or the like.

In the suspension polymerization method, the monomer system 10
It is preferable to use 300 to 3000 parts by mass of water as a dispersion medium with respect to 0 parts by mass.

Preferably, the stirring speed and time are adjusted so that the droplets of the monomer composition have the desired size of the toner particles, and the granulation is carried out. Thereafter, by the action of the dispersion stabilizer, stirring may be performed to such an extent that the particle state is maintained and the particles are prevented from settling.

The polymerization temperature is 40 ° C. or higher, generally 50 to
The polymerization is carried out at a temperature of 90 ° C. Further, the temperature may be raised in the latter half of the polymerization reaction, and furthermore, in the latter half of the reaction to remove unreacted polymerizable monomers, by-products, and the like, or by partially distilling the aqueous medium after completion of the reaction. Is also good.

After the completion of the reaction, the pH is adjusted, the dispersion stabilizer is dissolved, and the resulting toner particles are collected by washing, filtration, and dried.

Here, it is important to remove the dispersion stabilizer.
Since the dispersion stabilizer used in the polymerization method generally significantly lowers the charging performance of the toner, it is necessary to remove the dispersant. If the dispersant is not completely removed, problems such as a decrease in image density and fogging are likely to occur in an environment where the toner is difficult to be charged.

As a method for removing the dispersion stabilizer, it is general to add an acid or an alkali before dissolving in the medium before filtering off from the medium, and then filter off with the medium. here,
Some medium adheres to the toner surface after filtration. And the dispersion stabilizer is dissolved in this medium,
When the toner to which the medium in which the dispersion stabilizer is dissolved is attached is dried in a subsequent step, only the medium is removed, and the dissolved dispersion stabilizer is concentrated and adheres to the toner surface. Therefore,
It is important to reduce the concentration of the dispersion stabilizer in the medium attached to the toner surface after filtration.

As a method for lowering the concentration of the dispersion stabilizer in the medium, a washing liquid such as water is added to the wet toner after filtration to reduce the concentration of the dispersion stabilizer in the washing liquid, followed by re-filtration. There is a method of reducing the amount of the dispersion stabilizer, and if necessary, the steps of adding a washing liquid and filtering may be repeated several times to make the amount of the dispersion stabilizer equal to or less than the desired remaining amount of the dispersion stabilizer.

Here, as a filtering device used for filtering,
A filtration device having a washing function has been preferably used because of its excellent capital investment and installation space. Examples of a filtering device having a washing function include a filter press and a belt filter disclosed in JP-A-08-160661. However, in these devices, when the cleaning liquid is added, since the toner is in a cake form, the cleaning liquid and the toner cannot be mixed, and there is a concern that the cleaning of the toner is likely to be uneven, and high-definition and high-durability printing in recent years has been concerned. Some high-quality toners that require high quality have been required to review the filtration and cleaning methods.

The high quality toner as described above is disclosed in
As disclosed in JP-A-160661, a wet toner filtered from a medium is re-dispersed in a cleaning liquid such as water or alcohol to form a reslurry liquid, and then re-filtered. be able to.

As a reslurry method, a so-called batch type reslurry method is generally used, in which a wet toner is collectively charged into a container such as a tank in which a predetermined amount of cleaning liquid is stored in advance, stirred and mixed for a predetermined time, and then taken out. It is. As a filtration device before and after reslurry, in addition to the above-described filter press and belt filter, a dedicated machine for solid-liquid separation such as a centrifuge or a decanter can be used.

However, the batch type reslurry method is
Since a large-capacity reslurry tank is indispensable, there has been a problem in that the installation space is limited, and when the scale is increased, the uniformity of cleaning is reduced due to the reduced uniformity of stirring. In addition, when the filtration device in the preceding process is a continuous processing device, a buffer tank for wet toner before washing is newly required, and when the filtering device in the subsequent process is a continuous processing device, a buffer tank for a reslurry liquid is newly required. For example, there is a problem that the process is discontinuous and extra capital investment is required.

Therefore, the present inventors have devised a reslurry system of substantially continuous processing, and have solved the above-described problems of installation space and scale-up.

That is, a flow of the cleaning liquid is generated by its own weight or a liquid sending pump or the like, and the wet toner before cleaning is supplied little by little into the flow of the cleaning liquid to prepare a reslurry liquid of the cleaning liquid and the toner. The flow of the cleaning liquid may be any of a continuous flow, a pulsating flow, and an intermittent flow, and the wet toner before cleaning may be supplied continuously or intermittently in accordance with the flow of the cleaning liquid so that the concentration of the reslurry liquid becomes constant.

Generally, it is preferable to use water or the medium itself as the cleaning liquid. The mixing ratio of the washing liquid and the wet toner before washing varies depending on the composition of the toner, the mass ratio of the toner and the medium during the polymerization reaction (the mass of the medium / the mass of the dry toner), the properties of the filtration devices before and after, and the desired toner washing level. The ratio of the washing liquid mass / the dry toner mass is 0.5 to
The weight ratio can be selected from between 10 times the mass ratio of the toner and the medium during the polymerization reaction, but is generally from 1 to 2 times the mass ratio of the toner and the medium during the polymerization reaction.

As a method of mixing the reslurry liquid, there is a method of improving the mixing state by providing a fixed stirring blade such as a rotating stirring blade or a static mixer in a pipe. As a method of rotating the stirring blade, a power source may be provided independently, but it is possible to use a liquid sending blade of the liquid sending pump itself or a stirring blade provided coaxially with the liquid sending blade and having the same power source. Economically favorable.

When the stirring blade is rotated by the power of the liquid feed pump, the supply port of the wet toner before cleaning needs to be provided on the suction side of the liquid feed pump because the cleaning liquid and the toner are mixed in the liquid feed pump. If the supply port for the pre-cleaning wet toner is provided in the suction side pipe, the pre-cleaning wet toner can be mixed into the cleaning liquid by using the suction pressure. It is preferable to approach the liquid feed pump.

As described above, as a device in which the liquid feed pump, the stirring blade, and the wet toner supply port before washing are integrated, Pow Blender (Osame Kogyo Co., Ltd.), Super Shock Dissolver (Noritake Co., Ltd.) and the like are available. is there.

The reslurry liquid mixed with the rotating stirring blades or fixed blades may be filtered again and dried as it is. However, the reslurry may be circulated through the present reslurry apparatus or may be resirred with another reslurry apparatus. After that, it can be re-filtered and dried.

The method for filtering and washing toner particles, which is a feature of the present invention, will be specifically described with reference to the drawings.

FIG. 4 is a schematic view showing an example of a conventional toner manufacturing apparatus. The reslurry device 2 shown in FIG.
The wet toner 13 before washing is put into the container storing the toner 4 at a time, stirred by the stirring blade 27 or the like, and after a predetermined time has elapsed, the entire amount is sent to the next step.

On the other hand, FIGS. 1 to 3 are schematic views of an example of a toner manufacturing apparatus used in the present invention.

In FIG. 1, a toner suspension 11 in which an acid or an alkali is added and a dispersion stabilizer is dissolved in a medium is solid-liquid separated by a first filtration device 1 into a medium 12 and a wet toner 13 before washing. The obtained wet toner 13 before washing is crushed by a crushing device (not shown) if necessary, and then mixed with a cleaning liquid 14 such as water in the reslurry device 2 to become a reslurry liquid 15. The obtained reslurry liquid 15 is solid-liquid separated into a cleaning liquid 16 and a cleaned wet toner 17 by the second filtration device 3. The first filtration device 1 and the second filtration device 2 may be provided separately or may be shared by one. The obtained washed wet toner is crushed by a crusher (not shown) if necessary,
Although it can be sent to the next step, depending on the desired washing level, reslurry and re-filtration may be repeated several times before sending to the next step.

FIG. 2 is a sectional view showing an example of the reslurry apparatus 2 of the present invention. The reslurry device 2 shown in FIG.
The main component is a liquid supply pump in which the liquid supply blades 23 rotate to transfer the fluid from the suction side pipe 21 to the discharge side pipe 25. The cleaning liquid 14 is supplied to the suction side pipe 21 and flows in the direction of the arrow in the figure. The suction side pipe 21 is provided with a supply port 22 for the pre-cleaning wet toner 13, and the pre-cleaning wet toner 13 is sequentially mixed into the cleaning liquid 14 by a suction effect generated by the flow of the cleaning liquid 14.
If it is necessary to keep the mixing ratio between the wet toner 13 before cleaning and the cleaning liquid 14 constant, a means 28 for controlling the supply amount of the wet toner 13 before cleaning may be provided. As a control method, there are a diameter of a supply port, opening and closing of a damper, a fixed-amount supply means using an auger or the like. The mixed liquid is transferred to the discharge-side pipe 25 by the liquid sending blades 23 and is sequentially mixed with the mixed liquid to form the reslurry liquid 15. At this time, the discharge side pipe 2
A filter 24 such as a screen mesh may be provided in front of 5. The filter 24 includes a wet toner 24 before cleaning.
To prevent the agglomerates from passing through the reslurry device 2
It also has a function of generating a back pressure inside to improve the mixing effect of the liquid sending blade 23.

FIG. 3 is a sectional view showing another example of the reslurry apparatus 2 of the present invention. Reslurry device 2 shown in FIG.
Creates a flow of the cleaning liquid 14 by gravity or a power source (not shown), and provides a supply port 22 for the pre-cleaning wet toner 13 in a pipe through which the cleaning liquid 14 flows. The toner 13 is sequentially mixed into the cleaning liquid 14. When it is necessary to keep the mixing ratio between the wet toner 13 before cleaning and the cleaning liquid 14 constant, a means 28 for controlling the supply amount of the wet toner 13 before cleaning may be provided as in FIG. The mixed solution is fixed blade 2
6 to form a reslurry liquid 15.

The obtained washed wet toner is dried by a dryer such as a fluidized bed dryer, a flash dryer and a vacuum dryer.

An external additive may be added to the toner of the present invention for imparting various toner properties. Examples of the external additives used include metal oxides (aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, tin oxide, zinc oxide, etc.) and nitrides (silicon nitride, etc.). -Carbide (such as silicon carbide) metal salts (calcium sulfate, barium sulfate, calcium carbonate, etc.), fatty acid metal salts (zinc stearate, calcium stearate, etc.), carbon black, silica, etc. are used.

These external additives are used in an amount of 0.01 to 10 parts by mass, preferably 0.05 to 5 parts by mass, based on 100 parts by mass of the toner particles. These external additives may be used alone or in combination. Respectively,
Those subjected to a hydrophobic treatment are more preferable.

A Coulter Counter TA-II or Coulter Multisizer II (manufactured by Coulter Inc.) is used as an apparatus for measuring the average diameter and the particle size distribution of the toner. The electrolyte is about 1% N using primary grade sodium chloride.
An aqueous aCl solution is prepared.

The measuring method is as follows.
0.1 to 5 ml of a surfactant, preferably an alkylbenzenesulfonate, is added as a dispersant in ~ 150 ml;
Further, 2 to 20 mg of a measurement sample is added.

The electrolytic solution in which the sample was suspended was subjected to dispersion treatment for about 1 to 3 minutes using an ultrasonic disperser, and the volume and number of the toner were measured by using the measuring device with a 100 μm aperture as the aperture. The distribution and number distribution were calculated. Then, the weight-based weight average particle diameter (D4) (the representative value of each channel is taken as the representative value of each channel) obtained from the volume distribution according to the present invention was obtained.

In the present invention, the water content is 5%.
g was collected on an aluminum dish, and it was precisely weighed (A [g]).
It is left for 1 hour in a dryer set at 05 ° C., cooled, precisely weighed (B [g]), and calculated by the following formula.

Water content = ((AB) / A) × 100 [%]

[0072]

The basic structure and features of the present invention have been described above. Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples of the present invention. However, of course, this does not limit the invention in any way.

Example 1 450 parts by mass of a 0.1 M Na ₃ PO ₄ aqueous solution was charged into 700 parts by mass of ion-exchanged water, heated to 60 ° C., and then Clearmix CLS-30.
4500 rpm using S (M, Technique)
And stirred. 1.0M-CaCl ₂ aqueous solution 68
Parts by mass were gradually added to obtain an aqueous medium containing a calcium phosphate salt.

On the other hand, 170 parts by mass of (monomer) styrene 30 parts by mass of n-butyl acrylate (colorant) I. Pigment Blue 15: 3 10 parts by mass (charge control agent) Di-t-butylsalicylic acid metal compound 2 parts by mass (polar resin) Saturated polyester 15 parts by mass (acid value 10 mgKOH / g, peak molecular weight; 8500) (release agent) Ester wax (melting point: 65 ° C.) 40 parts by mass The above formulation was heated to 60 ° C., and was uniformly dissolved and dispersed. Into this, 8 parts by mass of a polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into the aqueous medium and stirred at 4500 rpm for 15 minutes in a clear mix at 60 ° C. under an N ₂ atmosphere to granulate the polymerizable monomer composition. did.

Thereafter, while stirring with a paddle stirring blade, 70
C., and reacted for 10 hours. After the completion of the polymerization reaction, 8
The residual monomer was distilled off at 0 ° C./reduced pressure, and after cooling, hydrochloric acid was added to dissolve the calcium phosphate, followed by solid-liquid separation with a belt filter. The obtained wet toner before washing was a cake having a water content of 27%. After the wet toner before washing was disintegrated, it was mixed with 1150 parts by mass of ion-exchanged water using a reslurry apparatus shown in FIG. 2 to prepare a reslurry liquid, and then subjected to solid-liquid separation again using a belt filter.

The water content of the obtained wet cake was 26%. Then, after crushing, it was dried to obtain colored resin particles. In addition, since all of the series of processes were capable of continuous processing, miniaturization and efficient operation of each apparatus became possible, and processing could be performed at a lower cost than before.

(Evaluation of Cleaning State) The cleaning state was evaluated by the amount of the remaining dispersion stabilizer. The amount of the remaining dispersion stabilizer was quantitatively analyzed using a fluorescent X-ray analyzer (RIX3000). When the value of the residual dispersion stabilizer is 500 ppm or less, there is no substantial problem. However, when the value exceeds 500 ppm, the chargeability of the toner decreases. The amount of the residual dispersion stabilizer in this example was 150 ppm, which is a level that is not a problem.

To 100 parts by mass of the above-obtained colored particles, 1.0 part by mass of hydrophobic silica having a specific surface area of 200 m ² / g by the BET method was added and mixed by a mixer. A toner was obtained.

In this example, the weight average particle size of the obtained toner was 6.8 μm.

(Evaluation of Image Performance) The image performance was evaluated by performing a durability test on 8,000 sheets continuously in an environment of high temperature and high humidity (temperature of 30 ° C., humidity of 80%) and measuring fog. The durability test was performed using a modified LBP-2030 machine manufactured by Canon Inc. For fog on paper, use a reflection densitometer (T
OKYO DENSHOKU CO. , LTD R
EFLECTOMETER ODEL TC-6DS)
It measured using. That is, when the worst value of the reflection density of the white background after printing measured by the reflection densitometer is Ds, and the average reflection density measured by the reflection densitometer on the paper before printing is Dr, the difference between these values (Ds -Dr) was determined, and this was defined as fog on paper. The fog amount on paper is 2%
In the following cases, the image is a good image with substantially no fogging on paper, but if it exceeds 2%, the image is unclear with fog on paper conspicuous. In the present example, evaluation was performed on images after 8,000 sheets of durability, and high-quality images could be stably obtained over 8000 sheets without fogging exceeding 2%.

Example 2 A wet cake of polymerized toner particles was obtained in the same manner as in Example 1 except that the reslurry apparatus shown in FIG. 3 was used.

The water content of the obtained wet cake was 26%. Then, after crushing, it was dried to obtain colored resin particles. In addition, since all of the series of processes were capable of continuous processing, miniaturization and efficient operation of each apparatus became possible, and processing could be performed at a lower cost than before.

The toner thus obtained was evaluated for the cleaning state in the same manner as in Example 1. As a result, the amount of the remaining dispersion stabilizer was 190 ppm, which is a level that is not a problem.

Further, using the toner obtained as described above, an image formation test was carried out by externally adding the toner in the same manner as in Example 1, and the fog was confirmed.
, And a high-quality image could be stably obtained.

Comparative Example 1 A wet cake of polymerized toner particles was obtained by performing the same operation as in Example 1 except that the reslurry apparatus shown in FIG. 4 was used. In addition, the stirring time in the reslurry apparatus was set to an extremely short time of 5 minutes in order to make it the same as in Examples 1 and 2.

The toner thus obtained was evaluated for the cleaning state in the same manner as in Example 1. As a result, although the amount of the residual dispersion stabilizer was an average level of 420 ppm, which was no problem, a portion where the amount exceeded 500 ppm was partially measured.

Further, the toner obtained above was externally added in the same manner as in Example 1 to perform an image formation test, and the fog was confirmed. The fog was found to be about 2% over 8,000 sheets from the beginning. The level changed, and was at an acceptable level for character image output, but at an unacceptable level for high-quality images such as photographs.

Comparative Example 2 A wet cake of polymerized toner particles was obtained by performing the same operation as in Example 1 except that the reslurry step and the second solid-liquid separation step were omitted. Note that 1150 parts by mass of ion-exchanged water as a washing liquid was sprinkled on the cake-like toner in the belt filter.

The toner obtained above was evaluated for the cleaning state in the same manner as in Example 1. As a result, although the amount of the residual dispersion stabilizer was 460 ppm on average, which was no problem, a portion where the amount exceeded 500 ppm was partially measured.

Further, using the toner obtained above, an image addition test was performed by externally adding the toner in the same manner as in Example 1, and the fog was confirmed. The fog was found to be about 2% over 8,000 sheets from the beginning. The level changed, and was at an acceptable level for character image output, but at an unacceptable level for high-quality images such as photographs.

Example 3 450 parts by mass of a 0.1 M Na ₃ PO ₄ aqueous solution were charged into 700 parts by mass of ion-exchanged water, heated to 60 ° C., and then Clearmix CLS-30.
4500 rpm using S (M, Technique)
And stirred. 1.0M-CaCl ₂ aqueous solution 68
Parts by mass were gradually added to obtain an aqueous medium containing a calcium phosphate salt.

On the other hand, (monomer) styrene 170 parts by mass n-butyl acrylate 30 parts by mass (colorant) Silane-coupling-treated magnetic material 180 parts by mass (charge control agent) Di-t-butylsalicylate metal compound 2 parts by mass ( Polar resin) Saturated polyester 15 parts by mass (Acid value 10 mg KOH / g, peak molecular weight: 8500) (Release agent) Ester wax (melting point 65 ° C) 8 parts by mass The above formulation is heated to 60 ° C and uniformly dissolved. Dispersed. To this, 8 parts by mass of a polymerization initiator tert-butylperoxy-2-ethylhexanate was dissolved to prepare a polymerizable monomer composition.

The polymerizable monomer composition was charged into the aqueous medium, and the mixture was stirred at 4500 rpm for 15 minutes in a clear mix at 60 ° C. in an N ₂ atmosphere to granulate the polymerizable monomer composition. did.

Thereafter, while stirring with a paddle stirring blade, 70
C., and reacted for 10 hours. After the completion of the polymerization reaction, sodium carbonate was added for the purpose of dissolving the residue of the polymerization initiator, the remaining monomer was distilled off at 80 ° C./reduced pressure, and after cooling, hydrochloric acid was added to dissolve the calcium phosphate salt. For solid-liquid separation. The obtained wet toner before washing was a powder having a water content of 24%. Without crushing the wet toner before washing, using a reslurry device shown in FIG.
After mixing with 1150 parts by mass of ion-exchanged water to prepare a reslurry liquid, solid-liquid separation was performed again using a decanter.

The moisture content of the wet cake obtained as described above was 25%. Thereafter, drying was performed to obtain colored resin particles. In addition, since a series of processes were all capable of continuous processing, miniaturization and efficient operation of each device became possible.
Processing at a lower cost than before was possible.

The toner thus obtained was evaluated for the cleaning state in the same manner as in Example 1. As a result, the amount of the remaining dispersion stabilizer was 120 ppm, which was a level that was not a problem.

Further, using the toner obtained above, an external image addition test was carried out in the same manner as in Example 1, and a fogging test was carried out. As a result, fog was found to be 2% over 8,000 sheets.
, And a high-quality image could be stably obtained.

[0099]

As described above, according to the present invention,
A method of producing a polymerization toner, which can efficiently and uniformly wash the surface of each toner particle and obtain a toner having excellent image characteristics that does not cause fogging or the like when an image is formed with the obtained toner. Provided.

Further, according to the present invention, there is provided a method for producing a polymerization toner capable of stably obtaining a high-quality image even in a high-temperature and high-humidity environment and obtaining a durable toner.

[Brief description of the drawings]

FIG. 1 is an example of a schematic diagram of a filtration / washing step used in the present invention.

FIG. 2 is an example of a schematic sectional view of a reslurry apparatus used in the present invention.

FIG. 3 is an example of a schematic sectional view of a reslurry apparatus used in the present invention.

FIG. 4 is an example of a schematic sectional view of a conventional reslurry apparatus.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 first filtration device 2 reslurry device 3 second filtration device 11 suspension of medium and toner 12 medium 13 wet toner before cleaning 14 cleaning liquid 15 reslurry liquid 16 cleaning liquid 17 cleaned wet toner 21 suction-side pipe 22 wet toner supply port 23 Liquid sending and stirring blade 24 Filter 25 Discharge side piping 26 Fixed blade 27 Stirring blade 28 Wet toner supply amount control means

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (reference) C08F 2/44 B01D 37/06 6/24 F term (reference) 2H005 AB06 EA07 4D066 BA03 4J011 JA01 JA04 JA13 JB26 PA03 PA27 PA33 PA37 PA38 PA43 PA45 PB25 PC02 PC07 4J100 AB02P AB04P AL03P AL04P AL05P AL08P AM02P AM15P AR05P AS02P AS03P BA31P CA01 FA21 GC35 JA09

Claims (11)

[Claims] 1. A polymerizable monomer composition containing at least a polymerizable monomer and a colorant is polymerized in a medium to produce colored polymer particles. Filtering, adding a washing liquid to the filtered colored polymer particles and reslurry, re-filtering the colored polymer particles from the reslurried liquid,
A method for producing a polymerized toner by drying the re-filtered colored polymer particles, wherein the re-slurry step supplies and mixes the colored polymer particles little by little into a washing liquid that flows continuously or intermittently. A method for producing a polymerization toner, comprising successively producing a reslurry liquid. 2. The method for producing a polymerization toner according to claim 1, wherein a control means for supplying a small amount of unwashed colored polymer particles is added to sequentially produce a reslurry liquid. 3. A method for continuously or intermittently flowing a cleaning liquid by a liquid feed pump, wherein the unwashed colored polymer particles are supplied little by little into the cleaning liquid on the suction side of the liquid feed pump. The method for producing a polymerization toner according to claim 1 or 2, wherein: 4. The method according to claim 3, wherein the liquid supply pump is a blade-type liquid supply pump, and the cleaning liquid and the unwashed colored polymer particles are mixed by the blades. Method. 5. The method according to claim 1, wherein a mixed liquid of the washing liquid and the unwashed colored polymer particles is passed through fixed blades in a pipe to improve a mixing state. A method for producing a polymerization toner. 6. A polymerizable monomer composition containing at least a polymerizable monomer and a colorant is polymerized in a medium containing a dispersion stabilizer to produce colored polymer particles. An acid or an alkali is added to the suspension containing the colored polymer particles to dissolve the dispersion stabilizer in the medium, the unwashed colored polymer particles are separated from the medium by filtration, and the filtered unwashed colored polymer particles are filtered. A re-slurry, washing the colored polymer particles from the re-slurry again, and drying the re-filtered washed colored polymer particles to produce a polymerized toner. A method for producing a polymerization method toner, characterized in that a reslurry step is a step of supplying a small amount of unwashed colored polymer particles little by little into a washing liquid flowing continuously or intermittently and mixing to sequentially produce a reslurry liquid. 7. The method for producing a polymerization toner according to claim 6, wherein a control means for supplying a small amount of unwashed colored polymer particles is added to sequentially produce a reslurry liquid. 8. A method of continuously or intermittently flowing a cleaning liquid by a liquid feed pump, wherein a small amount of unwashed colored polymer particles is supplied into the cleaning liquid on the suction side of the liquid feed pump. The method for producing a polymerization toner according to claim 6 or 7, wherein: 9. The method according to claim 8, wherein the liquid supply pump is a blade-type liquid supply pump, and the cleaning liquid is mixed with the unwashed colored polymer particles by the blades. Method. 10. The method according to claim 6, wherein a mixed liquid of the washing liquid and the unwashed colored polymer particles is passed through fixed blades in a pipe to improve a mixing state. A method for producing a polymerization toner. 11. The amount of the dispersion stabilizer remaining in the washed colored polymer particles is 500 to the washed colored polymer particles.
The method for producing a polymerization toner according to any one of claims 6 to 10, wherein the content is not more than ppm.