JP3332394B2 - Method for producing toner particles - Google Patents

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 toner particles used in a method for visualizing a latent image.

[0002]

2. Description of the Related Art In order to visualize an electric or magnetic latent image or the like on a recording medium, it is possible to adsorb electroconductive or magnetically sensitive fine particles called toner to the latent image. There is an image forming method for forming a visual image.

[0003] As a representative example of the electrophotographic method, many methods are known as described in, for example, US Patent No. 2,297,691. In this electrophotography, generally, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means, and then the latent image is developed using toner to form a toner image. Then, if necessary, the toner image is transferred to a transfer material such as paper, and then the toner image is fixed to the transfer material using heat, pressure, solvent vapor, or the like, thereby obtaining a copy.

Conventionally, toners used for these purposes have generally been prepared by mixing and melting a coloring material such as a dye, a pigment or a magnetic material in a thermoplastic resin, uniformly dispersing the coloring material, and then pulverizing and classifying. As a result, a toner having a desired particle size has been manufactured. This method is relatively stable as a technology, and each material and each process can be relatively easily managed.

However, in this method, energy efficiency is low, such as melting the material once together with a binder resin to mix and fix the material, and further cooling and mechanically grinding the melt. Further, since the toner is made into fine particles by mechanical pulverization, the particle size tends to be widened, and it is necessary to prepare a desired particle size distribution in a subsequent classification step, and there is also a problem that the product yield cannot be increased. As a new manufacturing method for solving these problems, a toner manufacturing method by a so-called polymerization method has been proposed.

For example, JP-B-36-10231, JP-B-47-51830, and JP-B-51-14895.
JP-A-53-17735, JP-A-53-17735
There is a method for producing a toner by a so-called suspension polymerization method described in JP-A-17736 and JP-A-53-17737. In the suspension polymerization method, substances required to be included in the toner, such as a binder resin, a colorant such as a dye or a pigment, a magnetic substance, carbon black, a charge control agent, and a release agent such as wax or silicone oil. Is optionally dissolved or dispersed in a polymerizable monomer together with a polymerization initiator, a dispersant, and the like to form a polymerizable composition, and the polymerizable composition is dispersed in an aqueous continuous phase containing a dispersion stabilizer. After forming fine particles using a disperser, the polymerization reaction is caused to solidify,
At the end of the polymerization, toner particles having a desired particle size are to be obtained at a stretch.

According to the present method, it is desired to omit not only the melting step and the pulverizing step but also the subsequent classification step, and the cost reduction effect such as energy saving, shortening of the time, improvement of the process yield and the like can be obtained. large.

[0008] In the suspension polymerization method, the viscosity of the polymerization reaction system increases as the polymerization proceeds, including the suspension polymerization method toner, and the transfer of radicals and polymerizable monomers becomes difficult. In this case, a large amount of the polymerizable monomer component tends to remain. In particular, in the case of a suspension polymerization toner, a component that may inhibit a polymerization reaction, such as a dye, a pigment (particularly carbon black), a charge control agent, and a magnetic substance, is contained in the polymerizable monomer system. In addition, since the polymerizable monomer is present in a large amount, unreacted polymerizable monomers are more likely to remain. If there is a component that acts as a solvent for the binder resin as well as the polymerizable monomer in the toner, it will lower the fluidity of the toner and deteriorate the image quality,
This leads to a decrease in blocking resistance. In addition to the performance directly related to the toner, especially when an organic semiconductor is used as the photoconductor, deterioration of the photoconductor such as a memory ghost or blurred image may occur in addition to the fusion of the toner to the drum. . In addition to the matters relating to the performance of such products, there is a problem that the polymerizable monomer components and the like volatilize at the time of fixing and generate an odor.

As a means for reducing the amount of the residual polymerizable monomer, there is firstly an improvement in the polymerization conversion rate of the polymerizable monomer itself. As one of the methods, it is extremely effective to increase the amount of a polymerization initiator at the time of polymerization. However, the molecular weight distribution of the obtained toner is reduced to a desired molecular weight distribution (in the case of a styrene-acryl type, the molecular weight is 10,000 to 5%). In many regions, the balance between the fixing start temperature and the fixing strength or toner strength is not good). If a plurality of polymerization initiators having different half-lives are used to suppress the amount of radical species generated at the start of polymerization and to increase the total amount of the initiator, the reduction in molecular weight is suppressed and the molecular weight distribution is expanded ( This has a significant effect when heat roll fixing is adopted), but it is not always sufficient because it cannot overcome the viscosity barrier.

As a method of lowering the viscosity of the polymer to increase the mobility of the polymerizable monomer, a solvent may be added, a plasticizer may be added, a chain transfer agent may be added, or the temperature may be increased. However, there remains a problem with the toner at the end of the polymerization. Is to suppress the amount of the polymer on the polymer side which affects the viscosity, while not reducing the amount of the radical at the same time, but to date no satisfactory results have been obtained. Is to melt the polymer by heat and also to cause thermal polymerization.At this time, if a polymerization initiator that decomposes at a high temperature to generate radical species is coexisted, the polymerizable monomer can be more effectively formed. Can be consumed. However, this method has difficulty in the case of polymerized toner in terms of dispersion stability and prevention of aggregation.

Therefore, since the polymerizable monomer is consumed by increasing the degree of polymerization, the polymerizable monomer vapor is recovered from the suspension and the residual polymerizable monomer in the toner is expelled from the toner system. Can reduce the amount of residual polymerizable monomer, but it takes a very long time because the organic solvent is diffused through water. In order to shorten the time, if the suspension system is vigorously stirred to increase the diffusion area, air is entrained and bubbles are generated, and the toner particles float on the suspension interface in a form attached to the bubbles. There is a risk that defective toner is generated due to aggregation of toner particles, change in polymerization conditions, and the like.

As a method for reducing the process time, Japanese Patent Laid-Open No.
JP-A-70765 discloses that after suspension polymerization, the obtained resin is heated at a temperature not lower than Tg, and the amount of water at the end of polymerization is 5
There has been proposed a method for producing a resin for toner in which about 50% by weight of water is distilled off. According to this method, the amount of residual polymerizable monomer in the resin can be reduced in a short time,
Energy loss is large, and when used in a method for producing a polymerized toner, there is a strict regulation on particle size, unlike the toner resin disclosed in Japanese Patent Application Laid-Open No. 1-70765, in that it prevents aggregation of particles. It is difficult to adopt the method as it is.

As another method for shortening the production time, Japanese Patent Application Laid-Open No. 1-3303450 discloses that a polymerization product obtained by a suspension polymerization method dissolves a monomer component during the polymerization, A method has been proposed in which a coalesced component is immersed in a highly volatile organic solvent in which it does not dissolve and stirred, and then a polymerization product is taken out from the solvent and dried. However, this method has a disadvantage that components soluble in an organic solvent cannot be contained in the toner.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing toner particles which has solved the above-mentioned problems.

Another object of the present invention is to provide a method for producing toner particles having excellent developability and having less residual polymerizable monomer.

Another object of the present invention is to provide a method for efficiently producing a toner having a narrow particle size distribution, high fluidity, good blocking resistance and good image quality.

[0017]

SUMMARY OF THE INVENTION The present invention provides an inorganic
After forming droplets containing the polymerizable monomer and the wax in the toner particle size in an aqueous suspension containing a dispersant, 50-9
A method for producing toner particles by producing the toner particles by polymerizing the polymerizable monomer at a polymerization temperature of 0 ° C. , wherein the polymerizable monomer contains at least styrene or a styrene derivative. The wax has a softening point of 30-130 ° C
Ri, and paraffin, polyolefin wax, paraffin modified products, polyolefin wax modified products, higher fatty acids, metal salts of higher fatty acids, higher fatty alcohols,
A wax selected from the group consisting of higher aliphatic esters and aliphatic amide waxes, wherein the content of the wax is
1 to 100 parts by weight per 100 parts by weight of the polymerizable monomer
The second aspect of the present invention relates to a method for producing toner particles (first invention), wherein steam is blown into the suspension and water is distilled off in the latter half of the polymerization reaction or after the end of the reaction.

Further, the present invention is formed by forming droplets containing the polymerizable monomer and the wax in the toner particle diameter in water <br/> of suspension containing an inorganic dispersant, 50 to 90 ° C. A method for producing toner particles by producing the toner particles by polymerizing the polymerizable monomer at a polymerization temperature of, wherein the polymerizable monomer contains at least styrene or a styrene derivative, and the wax is a softening point of 30 to 130 ° C., and paraffin <br/> down, polyolefin wax, paraffin modified products, polyolefin wax modified products, higher fatty acids, metal salts of higher fatty acids, higher aliphatic alcohols, higher aliphatic esters and A wax selected from the group consisting of aliphatic amide waxes, wherein the content of the wax is a polymerizable monomer 10
0 to 100 parts by weight per part by weight, after the end of the polymerization reaction or after the completion of the reaction, water-soluble solvent vapor or water-soluble gas is blown into the suspension, and the water-soluble solvent or water-soluble According to a second aspect of the present invention, there is provided a method for producing toner particles, which comprises removing a gas.

Hereinafter, the present invention will be described in detail.

In the suspended state, the toner particles can be suspended with a small force, and the danger of aggregation can be reduced even when heat effective to volatilize the remaining polymerizable monomer is applied. Further, since the polymerization proceeds from the interface, low molecular weight components can be included. When the suspending medium is an aqueous medium, it is possible to include a low-polarity component and a low surface energy component, which tend to lower the developing property of the toner, and therefore, it is desirable to complete the treatment in the suspension stage as much as possible. On the other hand, the diffusion of the polymerizable monomer vapor is slow due to the nature of suspension polymerization, and as described above, the suspension stability is destroyed when the diffusion rate is increased.

As a result of diligent studies, the present inventor has found that by blowing steam into an aqueous suspension, the gas-liquid interface is enlarged and the transport of polymerizable monomer vapor out of the polymerization system is accelerated. Since the gas phase is the same as that of the aqueous suspension, it has been found that bubbles do not remain forever and the stability of the suspension system is not lost, leading to the first invention.

The present inventor also expands the gas-liquid interface by blowing a water-soluble solvent vapor or a water-soluble gas into the aqueous suspension, and allows the polymerizable monomer vapor to flow out of the polymerization system. Faster transport, while the gas phase is eventually absorbed into the aqueous suspension, or the vapor condenses and reduces its volume. Alternatively, since the strength of the foam is reduced due to the absorption of steam into the water, the foam tends to burst, etc., it has been found that the foam does not remain forever, and the stability of the suspension system is not lost, and the second invention It has been reached.

In the method of the present invention, when the polymerization conversion reaches at least 90% or more, fresh steam generated outside is introduced into the aqueous suspension, and at the same time, vapor in the gas phase is collected. The polymerizable monomer was discharged to the outside of the reaction system by the removal, and finally, the amount of the residual polymerizable monomer was reduced to 1,000.
From the viewpoint of not giving an odor, the operation is preferably performed until it becomes 100 ppm or less. Good results are obtained when this water vapor is supplied in the form of fine bubbles as a whole through a porous tube or the like. It is desired that the reaction operation is adjusted so that the reaction system does not boil.

When a water-soluble solvent vapor or a dried water-soluble gas is used instead of water vapor, it is desirable that the water-soluble solvent vapor is introduced into the suspension and the same consideration is taken. As the water-soluble solvent used in the present invention, various solvents that are soluble in water can be used, but those having high solubility in water and high volatility are preferable from the viewpoint of the invention, and methanol, ethanol, and propanol are preferable. And lower ketones such as acetone are conveniently mixed with water at an arbitrary ratio and have a low boiling point. Examples of the water-soluble gas include an acidic gas such as carbon dioxide, and a basic gas such as ammonia. Good results can be obtained by supplying these water-soluble solvent vapors or water-soluble gases in the form of fine bubbles as a whole through a porous tube or the like. It is desired that the reaction operation is adjusted so that the reaction system does not boil. Furthermore, it is desirable to replenish water in an amount commensurate with the water distilled off during operation, and to take care that the amount of water does not change.

The polymerizable monomer constituting the polymerizable monomer system and the toner property imparting agent such as a colorant used in the present invention include the following.

Examples of the polymerizable monomer include styrene monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene, and methyl acrylate and acrylic. Ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, etc. Acrylic esters, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate
Examples thereof include methacrylates such as 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate, and monomers such as acrylonitrile, methacrylonitrile, and acrylamide.

These monomers can be used alone or as a mixture. Among the above-mentioned monomers, it is preferable to use styrene or a styrene derivative alone or in combination with another monomer from the viewpoint of the developing characteristics and durability of the toner.

In the present invention, polymerization may be carried out by adding a resin to the monomer system. For example, a monomer containing an amino group, a carboxylic acid group, a hydroxyl group, a sulfonic acid group, a glycidyl group or the like that cannot be used because the monomer is soluble in an aqueous suspension due to water solubility and causes emulsion polymerization. When it is desired to introduce them into the material, they can be used in the form of a copolymer such as a random copolymer, a block copolymer or a graft copolymer of these and styrene or ethylene. Further, if a polymer having a molecular weight different from the molecular weight range of the toner obtained by polymerizing the monomer is dissolved in the monomer and polymerized, a toner having a wide molecular weight distribution and high offset resistance can be obtained. I can do it.

As the coloring agent used in the present invention, known coloring agents can be used, and carbon black, iron black, C.I. I.
Direct Red 1, C.I. I. Basic Red 1,
C. I. Modant Red 30, C.I. I. Direct Blue 1, C.I. I. Direct Blue 2, C.I. I. Acid Blue 15, C.I. I. Basic Blue 3, C.I. I.
Basic Blue 5, C.I. I. Modant Blue 7,
C. I. Direct Green 6, C.I. I. Basic Green 4, C.I. I. Dyes such as Basic Green 6; graphite, cadmium yellow, mineral first yellow, navel yellow, naphthol yellow S, Hanza yellow G, permanent yellow NCG, tartrazine lake, molybdenum orange GTR, benzidine orange G, cadmium red 4R, watching red Calcium salt, Brilliant Carmine 3B, Fast Violet B, Methyl Violet Lake, Navy Blue, Cobalt Blue, Alkaline Blue Lake, Victoria Blue Lake, Quinacridone, Rhodamine Lake, Phthalocyanine Blue, Fast Sky Blue, Pigment Green B, Malachite Green Lake, Final Yellow There are pigments such as Green G. In the present invention, in order to obtain a toner using a polymerization method, it is necessary to pay attention to the polymerization inhibitory properties and aqueous phase migration of the colorant, preferably surface modification,
For example, it is better to perform a hydrophobic treatment with a substance having no polymerization inhibition. In particular, dyes and carbon black often have polymerization inhibitory properties, so care must be taken when using them. As a preferable method of surface-treating a dye system, a method of polymerizing a polymerizable monomer in the presence of these dyes in advance is exemplified.

The carbon black may be subjected to the same treatment as that for the dye, or to a grafting treatment with a substance that reacts with the surface functional group of the carbon black, for example, polyorganosiloxane or polyethylene glycol. Other pigments are less strongly inhibited by polymerization than carbon black, but it is better to perform the same treatment in consideration of dispersion into a polymerizable monomer.

In the present invention, a magnetic substance can be added to obtain a magnetic toner, but it is also preferable to use a magnetic toner after a surface treatment.

In the present invention, a charge control agent can be added to the toner material in order to control the chargeability of the toner. It is desired that the charge control agent has no polymerization inhibitory property or water phase transfer property.For example, as the positive charge control agent, a nigrosine dye, a triphenylmethane dye, a quaternary ammonium salt, an amine or imine-based dye is used. Compound,
Examples of the negative charge control agent include metal complex salts of salicylic acid or alkyl salicylic acid, gold-containing monoazo dyes, polymers having a carboxylic acid or sulfonic acid functional group, and humic acids and salts such as nitrohumic acid. .

In the suspension polymerization method of the present invention, a low-molecular-weight polymer such as wax is contained in the toner in order to improve the low-temperature fixing property or the releasability when combined with a hot roll fixing device. A low-temperature fluidizing component such as a plasticizer, a liquid rubber, and silicone oil, and a low surface energy substance can be contained.

Examples of the wax include paraffin / polyolefin waxes and modified products thereof, for example, oxides and grafted products, higher fatty acids and metal salts thereof, higher fatty alcohols, higher fatty esters, and fatty acids. Amide wax and the like. These waxes have a softening point of 30 to 30 according to the ring and ball method (JIS K2531).
Those having a temperature of 130C, preferably 50-100C are desirable. Further, it is desirable to dissolve in the polymerizable monomer.
If the softening point is 30 ° C. or lower, it is difficult to maintain the toner in the toner. If the softening point is 130 ° C. or higher, it is difficult to dissolve in the polymerizable monomer, and the dispersion of the wax tends to be uneven, and the polymer composition Is unfavorable because the particle size distribution becomes wide during granulation in order to increase the viscosity. The amount of the wax added is generally 1 to 10 per 100 parts by weight of the polymerizable monomer.
Although 0 parts by weight can be used, if it is 10 parts by weight or more, sufficient releasability and low-temperature fixability can be obtained.

As another means for improving the releasability, silicone oil can be used alone or in combination. The silicone oil used in the present invention preferably has a viscosity at 25 ° C. of 100 to 100,000 centistokes. Outside this range, the releasing effect is reduced, and the same problems as in the case of the wax are caused in terms of the toner retention and the granulation. It is generally appropriate to use 0.1 to 10 parts by weight of silicone oil per 100 parts by weight of polymerizable monomer. Even when used in an amount of 10 parts by weight or more, the releasability is already sufficiently exhibited, and the image surface is only sticky, so no further addition is required.

The polymerization initiator used in the present invention has a half-life (hereinafter abbreviated as [t 1/2]) of 0.5 to 0.5 during the polymerization reaction.
When the polymerization reaction is performed for 30 hours with an addition amount of 0.5 to 20% by weight of the polymerizable monomer, a molecular weight of 10,000 to 10% is obtained.
It is possible to obtain a polymer having a maximum value in the range of 10,000 to give the toner the desired strength and appropriate melting properties. Examples of the polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, and 1,1′-azobis (cyclohexane-1-carbonitrile) , 2,2'-azobis-4-methoxy-
Azo or diazo polymerization initiators such as 2,4-dimethylvaleronitrile and azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl par Peroxide-based polymerization initiators such as oxide and lauroyl peroxide;

In the present invention, a crosslinking agent may be added, and a preferable addition amount is 0.001 to 15% by weight.

In the toner production method of the present invention, the above-mentioned toner composition, that is, a colorant, a release agent, a plasticizer, a binder, a charge control agent, a crosslinking agent, a magnetic material, etc. Components necessary as a toner and other additives, for example, an organic solvent to be added to reduce the viscosity of the polymer formed by the polymerization reaction, a dispersant and the like are added as appropriate, and a homogenizer,
A monomer system uniformly dissolved or dispersed by a disperser such as a ball mill, a colloid mill, and an ultrasonic disperser is suspended in an aqueous medium containing a dispersion stabilizer. At this time, the particle size of the obtained toner particles becomes sharper by using a high-speed disperser such as a high-speed stirrer or an ultrasonic disperser to make the desired toner particle size at once. As for the timing of the addition of the polymerization initiator, it may be added at the same time as the other additives are added to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. Immediately after granulation and before initiating the polymerization reaction, a polymerization initiator dissolved in a polymerizable monomer or a solvent can be added.

After the granulation, stirring may be carried out using a conventional stirrer to such an extent that the particle state is maintained and the floating and settling of the particles are prevented.

[0040] In the suspension polymerization process of this invention, as a dispersion stabilizer, no machine dispersant hardly cause any harmful ultrafine powder and the reaction temperature is changed because they give the dispersion stability due to its steric hindrance Can be preferably used because the stability is hardly lost, the washing is easy, and the toner is hardly adversely affected. Examples of such inorganic dispersants include calcium phosphate, magnesium phosphate, aluminum phosphate, polyvalent metal phosphates such as zinc phosphate, calcium carbonate, carbonates such as magnesium carbonate, calcium metasilicate, calcium sulfate, barium sulfate and the like. Examples include inorganic salts, inorganic oxides such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite, and alumina.

[0041] These inorganic dispersants are used as polymerizable monomers 10
It is desirable to use 0.2 to 20 parts by weight alone with respect to 0 parts by weight, but 0.001 to 0.1 parts by weight because it is difficult to generate ultra-fine particles but a little difficult to atomize the toner. May be used in combination.

Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, pentadecyl sodium sulfate, sodium octyl sulfate,
Examples include sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be formed in an aqueous medium. For example, in the case of calcium phosphate, a water-insoluble calcium phosphate can be produced by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring, and more uniform and fine dispersion can be achieved. At this time, a water-soluble sodium chloride salt is by-produced at the same time, but if the water-soluble salt is present in the aqueous medium, the dissolution of the polymerizable monomer in water is suppressed, and the ultrafine toner due to emulsion polymerization is formed. This is more convenient because it hardly occurs. Since it becomes an obstacle when removing the residual polymerizable monomer at the end of the polymerization reaction, it is better to replace the aqueous medium or to desalinate with an ion exchange resin. The inorganic dispersant can be almost completely removed by dissolving with an acid or alkali after completion of the polymerization.

In the polymerization step, the polymerization temperature is 40
The polymerization is carried out at a temperature of at least 50 ° C., generally from 50 to 90 ° C. When the polymerization is carried out in this temperature range, the release agent and waxes to be sealed inside are precipitated by phase separation, and the encapsulation becomes more complete. In order to adjust the molecular weight to be low, at the start of polymerization, the temperature may be temporarily increased to 130 ° C. or higher, the initial radical concentration may be increased, and then the temperature may be set to the above-mentioned temperature to carry out the polymerization reaction. .
In order to consume the remaining polymerizable monomer, it is possible to raise the reaction temperature to 90 to 150 ° C. at the end of the polymerization reaction. At this time, if a polar substance is allowed to coexist in the monomer system, phase separation is further promoted. In particular, when the polar substance is a polar high molecular polymer, it is more effective.

Under the above conditions, the conversion rate increases almost linearly up to the polymerization conversion rate of 90%, but the solidification rate of the toner is reduced to 90%.
% Or more, the increase in the degree of polymerization is slowed, and when the polymerization conversion rate is 95% or more, it becomes very slow. At this point, since the molecular weight of the toner is already in a sufficient range, it is more efficient to proceed with the operation of removing the polymerizable monomer. Eventually at least one
000 ppm or less, more preferably 100 ppm or less.

The polymerization conversion, the amount of the residual polymerizable monomer, and the amount of the residual organic solvent were quantified by measuring the peak area of each substance by gas chromatography under the following conditions. For the measurement, a polymerization inhibitor was added to the sample, and 0.2 g after drying the sodium sulfate.
Was dissolved in 4 ml of THF.

G. C. Conditions Measuring device: Shimadzu GC-15A (with capillary) Carrier: N ₂ , 2 Kg / cm ² 50 ml / min. Split 10 ml / 13 s Column: ULBON HR-1 50 m × 0.25 mmφ Heating: 50 ° C. 5 min. Hold ↓ 10 ° C / min. 100 ° C ↓ 20 ° C / min. Hold at 200 ° C Sample amount: 2 μl Labeled substance: toluene

In the particle size measurement in the present invention, a Coulter counter TA-II (manufactured by Coulter Inc.) is used as a measuring device.
And an interface (manufactured by Nikkaki) for outputting the number distribution and volume distribution and a CX-1 personal computer (manufactured by Canon Inc.) are connected, and a 1% aqueous NaCl solution is prepared using a primary sodium chloride electrolyte.

To 100 to 150 ml of the aqueous electrolytic solution, 0.1 to 5 ml of a surfactant, preferably sodium alkylbenzenesulfonate, is added as a dispersant, and 0.5 to 50 mg of a measurement sample is further added. Perform a dispersion treatment for 1 to 3 minutes to prepare a sample solution.

The particle size distribution of particles having a particle size of 2 to 40 μm was measured using the Coulter Counter TA-II with an aperture of 100 μm as an aperture, and the length average diameter, weight average diameter, and weight average diameter were determined from the obtained number distribution and volume distribution. Each variation coefficient was calculated using the median value of the measurement channel as a representative diameter.

Hereinafter, the present invention will be specifically described based on examples and comparative examples.

[0052]

EXAMPLE 1 To 709 g of ion-exchanged water, 451 g of an aqueous 0.1 M Na ₃ PO ₄ solution was added, and after heating to 60 ° C., 1.0 M-C
67.7 g of an aCl ₂ aqueous solution is gradually added, and Ca ₃ (PO
₄ ) An aqueous medium containing ₂ was obtained.

Styrene 170 g 2-ethylhexyl acrylate 30 g C.I. I. Pigment Blue 15: 3 10 g Styrene-methacrylic acid-methyl methacrylate (85: 5: 10) Molecular weight (Mw = 58,000) 5 g Paraffin wax (mp. 70 ° C.) 30 g Di-t-butylsalicylate chromium complex 5 g Was heated to 60 ° C. and uniformly dispersed and dissolved at 12,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). The polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) [t1 / 2 = 140
min. at 60 ° C.] 10 g, and dimethyl-2,2 ′
Azobisisobutyrate [t1 / 2 = 1,270 mi
n. at 60 ° C., t1 / 2 = 80 min. at 80 ° C] 1
g was dissolved to prepare a polymerizable monomer system. The above polymerizable monomer system is charged into the aqueous medium, and the mixture is subjected to 10,000 rpm using a TK homomixer at 60 ° C. in an N ₂ atmosphere.
For 20 minutes to granulate suspension droplets of toner particle size. Then, at 60 ° C for 4 hours while stirring with paddle stirring blades.
Allowed to react for hours. At this point, the polymerization addition rate was 95%. Then, the reflux of the water vapor was stopped, the liquid temperature was raised to 80 ° C., and the water vapor of 100 ° C. was adjusted from the outside through a porous ceramic tube with one end closed so that the amount of distilled water per minute became 5 g. The stirring was continued for another 10 hours. After completion of the reaction, the suspension was cooled, and hydrochloric acid was added to add Ca ₃ (P
O ₄ ) ₂ is dissolved, filtered, washed with water and dried to obtain a weight average diameter =
8.2 μm (coefficient of variation [average diameter / standard deviation * 100%]
= 23.4%). At this point, the amount of the remaining polymerizable monomer was 90 ppm.

With respect to 100 parts by weight of the obtained toner, B
0.7 parts by weight of a hydrophobic silica having a specific surface area of 200 m ² / g by the ET method was externally added. To 7 parts by weight of this externally added toner, 93 parts by weight of a ferrite carrier coated with an acrylic resin were mixed to prepare a developer.

Using this developer and externally added toner, an image was formed using a Canon full color copying machine CLC-500. A clear, high-density image was obtained. Fixing was good, and no offset phenomenon was observed. When this developer was left in an environment of 35 ° C./80% RH for one month, the image quality was as good as the initial one. There was no styrene odor at the time of fixing, and no filming phenomenon on the photosensitive drum and no toner blocking phenomenon were observed even after 10,000 images were printed.

Comparative Example 1 The procedure of Example 1 was repeated except that no steam was introduced. Weight average diameter = 8.3 μm (coefficient of variation = 24.1)
%) Of the toner was obtained. The residual polymerizable monomer amount is 2,350
ppm. A developer was prepared from this toner in the same manner as in Example 1, and image formation was performed. As a result, a good image was obtained as in Example 1. However, styrene odor was emitted from around the fixing device. When this toner was left for one month in an environment of 35 ° C./80% RH, toner tribo decreased and image fog increased. When 10,000 sheets of images were formed, filming was slightly observed on the photosensitive drum, and the sharpness of the image was reduced.

Comparative Example 2 In Comparative Example 1, the temperature was raised to 100 ° C. after the completion of the polymerization reaction.
50% of the water was distilled off. Thereafter, the same treatment as in Example 1 was performed to obtain a polymerized toner having a residual polymerizable monomer content of 80 ppm. Although the unpleasant odor at the time of fixation was almost eliminated, the weight average particle diameter was 12.3 μm (coefficient of variation = 33.8%).

COMPARATIVE EXAMPLE 3 In Example 1, dried N at 100 ° C. was used instead of steam.
₂ gas was blown. At the time of the polymerization reaction, there was no effect at a flow rate enough to introduce oxygen for oxygen substitution. As the introduction was increased, the suspension began to foam and the polymer began to adhere to the walls. Even when the introduction of the gas was stopped, the bubbles did not disappear easily, and the obtained toner had many coarse pieces, the blocking temperature decreased by 5 ° C., and the fluidity deteriorated.

Example 2 In Example 1, the pressure was reduced to 500 mmHg, and the amount of water removed was doubled to 10 g. The same toner was obtained in half the operation time. No effect on the particle size and toner performance was observed, and a good toner was obtained as in Example 1.

Example 3 The same polymerizable monomer system as in Example 1 was charged into the same aqueous medium as in Example 1, and stirred at 10,000 rpm for 20 minutes with a TK homomixer at 60 ° C. in an N ₂ atmosphere. And
A suspension droplet of toner particle size was granulated. Thereafter, the mixture was reacted at 60 ° C. for 4 hours while stirring with a paddle stirring blade. At this point, the polymerization addition rate was 95%. Thereafter, the reflux of steam was stopped, the liquid temperature was set to 80 ° C, and 94 ° C from outside.
Of propyl alcohol vapor was supplied through a porous ceramic tube having one end closed, while adjusting the amount of introduction so that bubbles did not disappear halfway, 500 g in total was supplied to the suspension system, and stirring was continued for 5 hours. . After completion of the reaction, the suspension was cooled, hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) ₂ , filtered, washed with water and dried, and the weight average diameter was 7.9 μm (coefficient of variation [average diameter / standard deviation *] 100%] = 24.0%). At this time, the amount of the remaining polymerizable monomer is 7
It was 0 ppm.

With respect to 100 parts by weight of the obtained toner, B
0.7 parts by weight of a hydrophobic silica having a specific surface area of 200 m ² / g by the ET method was externally added. To 7 parts by weight of this externally added toner, 93 parts by weight of a ferrite carrier coated with an acrylic resin were mixed to prepare a developer.

Using this developer and externally added toner, image formation was performed using a full color copying machine CLC-500 manufactured by Canon. A clear, high-density image was obtained. Fixing was good, and no offset phenomenon was observed. When this developer was left in an environment of 35 ° C./80% RH for one month, the image quality was as good as the initial one. There was no styrene odor at the time of fixing, and no filming phenomenon on the photosensitive drum and no toner blocking phenomenon were observed even after 10,000 images were printed.

Comparative Example 4 The procedure of Example 3 was repeated, except that propyl alcohol vapor was not introduced, and the stirring time was further extended by 5 hours. Weight average diameter = 8.3 μm (coefficient of variation = 24.1%)
Was obtained. 2,350 pp residual polymerizable monomer
m. A developer was prepared from this toner in the same manner as in Example 3 and image formation was performed. As a result, a good image was obtained as in Example 3. However, styrene odor was emitted from around the fixing device. When this toner was left for one month in an environment of 35 ° C./80% RH, toner tribo decreased and image fog increased. When 10,000 sheets of images were formed, filming was slightly observed on the photosensitive drum, and the sharpness of the image was reduced.

Comparative Example 5 In Comparative Example 4, the temperature was raised to 100 ° C. after the completion of the polymerization reaction.
50% of the water was distilled off. Thereafter, the same treatment as in Example 3 was performed to obtain a polymerized toner having a residual polymerizable monomer content of 80 ppm. Although the unpleasant odor at the time of fixation was almost eliminated, the weight average particle diameter was 12.3 μm (coefficient of variation = 33.8%).

Comparative Example 6 In Example 3, dry N ₂ gas at 100 ° C. was blown instead of propyl alcohol vapor. During the polymerization reaction,
There was no effect at a flow rate enough to introduce oxygen. As the introduction was increased, the suspension began to foam and the polymer began to adhere to the walls. Even when the introduction of the gas was stopped, the bubbles did not disappear easily, and the obtained toner had many coarse pieces, the blocking temperature decreased by 5 ° C., and the fluidity deteriorated.

[0066]

According to the present invention, a toner having a small amount of residual polymerizable monomer and excellent developability can be obtained.

Continuation of front page (56) References JP-A-2-273758 (JP, A) JP-A-2-254468 (JP, A) JP-A-61-179202 (JP, A) JP-A-64-70765 (JP) JP-A-53-41387 (JP, A) JP-A-52-107087 (JP, A) JP-A-60-243664 (JP, A) JP-A-63-124055 (JP, A) 63-304002 (JP, A) JP-A-59-56410 (JP, A) JP-A-52-95792 (JP, A) JP-A-54-119588 (JP, A) JP-A-2-11604 (JP, A) A)

Claims (6)

(57) [Claims] 1. After forming a droplet containing a polymerizable monomer having a toner particle size and a wax in an aqueous suspension containing an inorganic dispersant, the polymerizable monomer is produced at a polymerization temperature of 50 to 90 ° C. A method for producing toner particles by polymerizing a body to produce toner particles, wherein the polymerizable monomer contains at least styrene or a styrene derivative, the wax has a softening point of 30 to 130 ° C , And paraffin, polyolefin-based wax, paraffin-modified product,
A wax selected from the group consisting of a modified polyolefin wax, a higher fatty acid, a metal salt of a higher fatty acid, a higher aliphatic alcohol, a higher aliphatic ester, and an aliphatic amide wax, wherein the content of the wax is a polymerizable monomer. 1
1 to 100 parts by weight per 100 parts by weight , wherein steam is blown into the suspension and water is distilled off in the second half or after the end of the polymerization reaction, and the water is distilled off. 2. After forming droplets containing a polymerizable monomer having a toner particle size and a wax in an aqueous suspension containing an inorganic dispersant, the polymerizable monomer is added at a polymerization temperature of 50 to 90 ° C. A method for producing toner particles by polymerizing a body to produce toner particles, wherein the polymerizable monomer contains at least styrene or a styrene derivative, the wax has a softening point of 30 to 130 ° C , And paraffin, polyolefin-based wax, paraffin-modified product,
A wax selected from the group consisting of a modified polyolefin wax, a higher fatty acid, a metal salt of a higher fatty acid, a higher aliphatic alcohol, a higher aliphatic ester, and an aliphatic amide wax, wherein the content of the wax is a polymerizable monomer. 1
1 to 100 parts by weight per 100 parts by weight. After the second half of the polymerization reaction or after the end of the reaction, a water-soluble solvent vapor or a water-soluble gas is blown into the suspension, and the water-soluble solvent or the water-soluble A method for producing toner particles, comprising removing a gas. 3. After the second half of the reaction or after completion of the reaction, a water-soluble solvent vapor selected from the group consisting of a lower alcohol vapor and a lower ketone vapor is blown into the suspension, and
3. The water-soluble solvent vapor is distilled off.
3. The method for producing toner particles according to item 1. 4. The method according to claim 3, wherein the water-soluble solvent vapor is methanol, ethanol, propanol or acetone. 5. A method of blowing a water-soluble gas selected from the group consisting of an acidic gas and a basic gas into the suspension after the latter half of the reaction or after the reaction, and distilling the water-soluble gas. The method for producing toner particles according to claim 2, wherein: 6. The method according to claim 5, wherein the water-soluble gas is a carbon dioxide gas or an ammonia gas.