JP3131759B2 - Electrostatic image developing toner and method of manufacturing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used in a method for visualizing an electrostatic latent image and a method for producing the same.

[0002]

2. Description of the Related Art Many electrophotographic methods are known, for example, as described in US Pat. No. 2,297,691. In this electrophotography,
In general, an electric latent image is formed on a photoreceptor by various means using a photoconductive substance, and then the latent image is developed with a toner to form a toner image. After transferring this toner image onto a transfer material such as described above, a copy is obtained by fixing the toner image to the transfer material using heating, pressurizing, heating and pressurizing, solvent vapor, or the like. At present, a fixing method using heat has become mainstream in terms of fixing strength of a copy, easiness of handling of a transfer, and work comfort. As a heat fixing method, there is a method using radiant heat as in a heat chamber method. However, a heat roller fixing method in which a heated roll-shaped heating element (for example, a heat roll) is pressed against a toner image to fix the toner image has a high thermal efficiency. It is used in most machines because of its height, high-speed response and high safety. However, even though the efficiency is high, the energy used for heat fusing occupies a considerable part in the copying machine, and the toner contacts the hot roll because the fused toner image and the hot roll are in direct contact. An offset phenomenon that adheres and stains a later image, or a winding phenomenon in which the object to be fixed is wound around the heat roll in some cases, may occur.

[0003] As a method for producing a toner, a colorant such as a dye or a pigment and an additive such as a charge control agent are melt-mixed in a thermoplastic resin, uniformly dispersed, and then the melt-kneaded product is cooled. There is known a method for producing toner particles having a desired particle size by a fine pulverizing means and a classifying means.

[0004] In these methods of producing a toner by a pulverization method, there is a limitation in adding a releasable substance such as a wax to toner particles. In order to achieve a sufficient level of dispersion of the release material, at a kneading temperature with the binder resin,
That is, it is not dissolved to be in a liquid state, and the content of the release material cannot be increased. Due to such restrictions, it is not easy to improve the fixability of the toner by the pulverization method.

On the other hand, there has been proposed a method of producing a toner containing a release agent such as a wax by a suspension polymerization method or an emulsion polymerization method. In this suspension polymerization method, a colorant (a polymerization initiator, a crosslinking agent,
After uniformly dissolving or dispersing a charge control agent and other additives to prepare a monomer composition, the monomer composition is appropriately dispersed in a continuous phase (for example, an aqueous phase) containing a dispersion stabilizer. The dispersion is carried out using a suitable stirrer and the polymerization reaction is carried out to obtain toner particles having a desired particle size.

In this suspension polymerization method, since the droplets of the monomer composition are granulated in a dispersion medium having a large polarity such as water, the component having a polar group contained in the monomer composition is dispersed. The non-polar component easily exists in the surface layer, which is the interface with the medium, and takes a pseudo capsule structure existing inside. By utilizing the characteristics of this manufacturing method, a low melting point wax can be contained in the toner particles.

[0007] The toner produced by the polymerization method can achieve both the anti-blocking property and the contradictory performance of low-temperature fixing by incorporating wax having a low melting point. Since the low-melting wax is included in the toner particles, the thermal conductivity of the toner is improved by the wax that melts at a low temperature without lowering the blocking resistance,
As a result, low-temperature fixing of the toner becomes possible. More preferably, high-temperature offset can be prevented without applying a releasing agent such as silicone oil to the fixing roller because the wax melted at the time of fixing also acts as a releasing agent.

However, when a large amount of low melting point wax is dissolved and dispersed in the monomer composition and granulated in an aqueous medium,
Granulation is more difficult than the monomer composition containing no wax, and the resulting toner tends to have a broad particle size distribution.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a toner for developing an electrostatic image and a method for producing the same, which solves the above-mentioned problems.

An object of the present invention is to provide a toner for developing an electrostatic image having a sharp particle size distribution and a method for producing the same.

An object of the present invention is to provide a toner for developing an electrostatic charge image which is excellent in low-temperature fixing property and excellent in anti-offset property during high-temperature fixing, and a method for producing the same.

An object of the present invention is to provide a toner for developing an electrostatic image having excellent blocking resistance and a method for producing the same.

[0013]

SUMMARY OF THE INVENTION The present invention relates to a toner for developing an electrostatic image having toner particles containing at least a binder resin, a colorant and a wax. When the content of the vinyl monomer or the mixture of the polymerizable vinyl monomer and the organic solvent is 1.0 or less.
The toner particles have a copolymerizable weight ratio of the polymerizable vinyl monomer, styrene or styrene derivative and butadiene or isoprene of 95: 5 to 6
A mixture containing at least 5:35 of a styrene-diene copolymer, a colorant, a wax and a polymerization initiator is mixed to prepare a polymerizable monomer composition, and the polymerizable monomer composition is mixed with an aqueous medium. The present invention relates to a toner for developing an electrostatic image, characterized in that it is a colored resin particle produced by dispersing and granulating the polymerizable polymerizable monomer in an aqueous medium.

Further, according to the present invention, the copolymerizable weight ratio of the polymerizable vinyl monomer, styrene or styrene derivative and butadiene or isoprene is from 95: 5 to 65:35.
A mixture containing at least a styrene-diene copolymer, a colorant, a wax and a polymerization initiator is prepared to prepare a polymerizable monomer composition, and the polymerizable monomer composition is dispersed in an aqueous medium. And producing a toner particle by polymerizing a polymerizable vinyl-based monomer in an aqueous medium to produce toner particles. The toner particles comprise a binder resin, a colorant, Contains at least wax,
The present invention relates to a method for producing a toner for developing an electrostatic image, wherein the content of a polymerizable vinyl monomer or a mixture of an organic solvent and a polymerizable vinyl monomer is 1,000 ppm or less.

The inventors of the present invention made use of the property that polymerization in an aqueous medium starts at the particle interface, the polar component is concentrated near the interface, and the non-polar component is concentrated at the center, so that a large amount of wax component is contained. We have developed toner that can be fixed at low temperatures.

In the suspension polymerization method, in the case of a styrene or acrylic polymerizable vinyl monomer, the amount of the polymerization initiator used is 0.5 to 20% by weight, and the half life of the polymerization initiator is 0.5.
When the polymerization temperature is set so as to be 30 hours, a toner composition preferable as a toner for heat fixing can be obtained.

If the polymerization conversion rate becomes 90% or more with this setting, the toner particles do not coalesce and become agglomerated even if stirring is stopped, and when the polymerization conversion rate reaches 97 to 98%, the toner particles are taken out. It only has to be dried.

However, when a large amount of a low melting point wax is contained in the toner particles, a high quality image can be obtained without any problem under a normal environment. May occur.

In the suspension polymerization method, as the polymerization reaction proceeds, the viscosity of the polymerizable monomer composition increases, so that the transfer of the radical type polymerizable vinyl monomer becomes difficult, and unreacted unreacted particles are present in the toner particles. The polymerizable vinyl monomer tends to remain. In the case of the toner by the pulverization method, the residual polymerizable monomer can be removed by heat applied during the production of the binder resin or during the melt-kneading, but it is high when the toner is directly produced by the suspension polymerization method. Since heat cannot be applied to the toner particles, a larger amount of polymerizable monomer is more likely to be incorporated in the toner particles than the toner produced by the pulverization method. When the toner produced by the suspension polymerization method is left at a high temperature in the absence of water, when the remaining unreacted polymerizable monomers gradually volatilize from the toner particle surface, the low molecular weight components inside the toner particles It is considered that the toner developability deteriorates due to the fact that non-polar components (for example, low melting point wax) are conveyed to the surface of the toner particles. In the toner particles, a small amount of a volatile organic solvent component other than the polymerizable monomer may be present, and by controlling the content thereof to 1,000 ppm or less, a low melting point is obtained. It is possible to obtain a toner which does not deteriorate even when the toner containing the wax is left at a high temperature.

It is important to directly obtain a toner having a sharp particle size distribution by a suspension polymerization method or an emulsion polymerization method in order to omit a classification step, to improve developability, and to improve image quality.

A styrene-diene copolymer having both a polymer property and a wax property and having a copolymer weight ratio of 95: 5 to 65:35 is dissolved and mixed in a polymerizable monomer to obtain a sharp particle size. Of the toner.

The reason is that the styrene-diene copolymer has an effect of favorably including the wax in the granulation step.

The styrene-diene copolymer used in the present invention is preferably a block copolymer in order to effectively exhibit the present invention.

When the copolymerization ratio of styrene or derivative in the styrene-diene copolymer exceeds 95% by weight (that is, when the copolymerization ratio of butadiene or isoprene is less than 5% by weight), If the effect of improving the granulation property is small, while the copolymerization weight ratio of styrene or a styrene derivative is less than 65% by weight, the blocking resistance of the toner decreases. If the copolymerization weight ratio of butadiene or isoprene exceeds 35% by weight and there are too many diene units, the stability of the particles of the polymerizable monomer composition in the aqueous medium will be reduced.

The styrene-diene copolymer is a block copolymer in which a styrene polymer chain or a styrene derivative polymer chain and a butadiene polymer chain or isoprene polymer chain are polymerized in an aqueous medium. This is preferred because of the granulation properties of the product and the improvement of the blocking resistance of the wax particles.

When a styrene-diene block copolymer is used, when a polymerizable monomer composition is granulated in an aqueous medium, a CH ₂ ＣＨCH— group existing in a butadiene polymer block portion or an isoprene polymer block portion is used. Increases the stability of the particles of the polymerizable monomer composition, more preferably suppresses the generation of fine particles and coarse particles, and sharpens the particle size distribution of the toner. Further, since the styrene polymer block portion or the styrene derivative polymer block portion has a high glass transition point, the blocking resistance of the toner is further improved.

CH _{2 of} styrene-diene copolymer
The ＣＨCH— group reacts with the polymerizable vinyl monomer during the polymerization of the polymerizable vinyl monomer to cause branching of the binder resin component,
Since the reticulation is enhanced, the offset resistance of the toner is improved.

The styrene-diene copolymer used in the present invention preferably has a weight average molecular weight of 30,000 to 500,000 (more preferably 50,000 to 300,000).

When the total double bonds remaining in the diene unit in the styrene-diene copolymer is 100% by weight, 5 to 60% by weight of CH ₂ ＝ CH— groups as side chains.
(More preferably 10 to 50% by weight) improves the blocking resistance of the toner, improves the offset resistance, and further improves the granulation property of the polymerizable monomer composition in an aqueous medium. It is more preferable in that it is performed.

The styrene-diene copolymer is preferably contained in the toner in an amount of 0.1 to 20% by weight. Further, the styrene-diene copolymer is contained in an amount of 1% based on the wax.
The content of about 50% by weight is preferable in that the wax can be satisfactorily included in the toner particles, and the blocking resistance and the fluidity of the toner are improved.

The wax is preferably contained in the toner in an amount of 5 to 30% by weight, and examples of the wax used in the present invention include paraffin, polyolefin, and ester wax. The wax having a melting point of 50 to 90 ° C. is preferable since low-temperature fixing can be achieved.

The polymerizable vinyl monomers constituting the polymerizable monomer composition used in the present invention include the following.

Examples of the polymerizable monomer include styrene; styrene derivatives such as o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, and p-ethylstyrene; methyl acrylate, ethyl acrylate; Acrylic esters such as n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate Classes: methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, methacrylic acid Acid phenyl, dimethylaminoethyl methacrylate, such as methacrylic acid esters of diethylaminoethyl methacrylate; acrylonitrile, methacrylonitrile, and such monomers of acrylamide.

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

In the present invention, a polymer other than the styrene-diene copolymer may be added to the polymerizable monomer composition for polymerization. For example, hydrophilic functional groups such as amino group, carboxylic acid group, hydroxyl group, sulfonic acid group, glycidyl group, and nitrile group which cannot be used because the monomer dissolves in an aqueous suspension to cause emulsion polymerization due to water solubility. When it is desired to introduce a polymer into a toner, a copolymer such as a random copolymer, a block copolymer, or a graft copolymer of a vinyl monomer having a hydrophilic functional group and a vinyl monomer such as styrene or ethylene is used. It can be used in the form of a union or a polycondensate such as polyamide, or a polyaddition polymer such as polyether or polyimine. The coexistence of such a high molecular polymer containing a polar functional group in the toner is preferable because the wax component is phase-separated, the encapsulation becomes better, and the performance of the toner is improved. As the usage amount,
It is preferably from 1 to 20% by weight based on the polymerizable vinyl monomer. The polymer having a polar functional group preferably has a weight average molecular weight of 5,000 or more. If the weight average molecular weight is less than 5,000, especially 4,000 or less, the blocking resistance decreases, which is not preferred. When 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.

Known coloring agents can be used in the present invention. For example, C.I. I. Direct Red 1, C.I. I. Basic Red 1, C.I. I. Modant Red 30, C.I. I. Direct Blue 1, C.I. I.
Direct Blue 2, C.I. I. Acid blue 15,
C. I. Basic Blue 3, C.I. I. Basic Blue 5, C.I. I. Modant Blue 7, C.I. I. Direct Green 6, C.I. I. Basic Green 4, C.I.
I. Dyes such as Basic Green 6, carbon black, graphite, cadmium yellow, mineral first yellow, navel yellow, naphthol yellow S, Hansa 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 And final yellow 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 property and the aqueous phase migration property of the colorant, and preferably surface modification, for example, hydrophobization by a substance having no polymerization inhibition. It is better to have it processed. 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 the dye, a method of polymerizing a polymerizable monomer in the presence of the dye in advance is exemplified.

As for carbon black, in addition to the same treatment as the above dye, it is also possible to carry out a grafting treatment with a substance (for example, polyorganosiloxane or polyethylene glycol) which reacts with the surface functional group of carbon black. There are few pigments other than carbon black that have strong polymerization inhibition, but it is better to perform the same treatment as carbon black in consideration of the improvement of uniform dispersibility in polymerizable monomers.

A magnetic toner may be obtained by adding a magnetic substance to toner particles.

The toner of the present invention may contain a charge control agent to stabilize the charge characteristics. A colorless or light-colored charge control agent that does not affect the color tone of the toner is preferable.

The polymerization initiator used in the present invention has a half-life of 0.5 to 30 hours during the polymerization reaction, and is added in an amount of 0.5 to 20% by weight of the polymerizable vinyl monomer. Is carried out, it is possible to obtain a polymer having a maximum molecular weight between 10,000 and 100,000, and it is possible to provide the toner with preferable strength and appropriate heat 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 can be used.

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

The method for producing a toner according to the present invention comprises a mixture containing at least a polymerizable vinyl monomer, a styrene-diene copolymer, a wax and a polymerization initiator (in some cases,
(A charge controlling agent, a crosslinking agent, a magnetic substance, an organic solvent, a release agent other than wax, etc.) may be uniformly dissolved by a dispersing machine such as a homogenizer, a ball mill, a colloid mill, or an ultrasonic dispersing machine. Alternatively, a polymerizable monomer composition is prepared by dispersion, and then the polymerizable monomer composition is dispersed 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 the polymerization reaction is started, a polymerization initiator dissolved in a polymerizable monomer or a solvent may be further added.

After the granulation, stirring may be performed using a conventional stirrer to such an extent that the particle state of the polymerizable monomer composition is maintained in the aqueous medium and the floating and sedimentation of the particles are prevented. .

In the method for producing the toner of the present invention, a known surfactant or an organic or inorganic dispersant can be used as a dispersion stabilizer. Among them, the inorganic dispersant hardly generates harmful ultrafine powder, Since dispersion stability is obtained, even if the reaction temperature is changed, the stability is hardly lost, the washing is easy, and the toner is hardly adversely affected. Examples of inorganic dispersants include fine powders of polyvalent metal salts of phosphate such as calcium phosphate, magnesium phosphate, aluminum phosphate, and zinc phosphate; fine powders of carbonate such as calcium carbonate and magnesium carbonate; calcium metasilicate, calcium sulfate, and sulfuric acid Inorganic salt fine powder such as barium; inorganic oxide fine powder such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite, and alumina.

These inorganic dispersants are preferably used alone in an amount of 0.2 to 20 parts by weight based on 100 parts by weight of the polymerizable vinyl monomer. In some cases, 0.001
0.1 parts by weight of a surfactant may be used in combination. As the surfactant, for example, sodium dodecylbenzene sulfate,
Sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate,
And potassium stearate.

When these inorganic dispersants are used, they may be used as they are, but it is preferable to form the inorganic dispersant particles in an aqueous medium in order to obtain fine inorganic dispersant particles. For example, in the case of calcium phosphate, an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride can be mixed under high-speed stirring to produce fine particles of calcium phosphate insoluble in water, and can be uniformly dispersed and have a high stability effect. . At this time, a water-soluble sodium chloride salt is simultaneously produced as a by-product, but when the water-soluble salt is present in the aqueous medium, the dissolution of the polymerizable vinyl monomer in water is suppressed, and the ultrafine particles formed by emulsion polymerization are formed. This is more convenient because toner hardly occurs. Since sodium chloride acts as an obstacle when removing the residual polymerizable vinyl monomer at the end of the polymerization reaction, it is better to replace the aqueous medium or desalinate the aqueous medium using an ion exchange resin. After the polymerization is completed, the inorganic dispersant is
It can be removed by dissolving with acid or alkali.

In the polymerization step, the polymerization is carried out at a polymerization temperature of 40 ° C. or higher, generally 50 to 90 ° C. When the polymerization is performed in this temperature range, the wax to be sealed inside the toner particles precipitates by phase separation as the polymerization proceeds, and the encapsulation becomes more complete. At the end of the polymerization reaction, the reaction temperature may be raised to 90 to 150 ° C. in order to consume the remaining polymerizable vinyl monomer.

Under the above conditions, the conversion rate increases almost linearly up to a polymerization conversion rate of 90%, but at a polymerization conversion rate of 90% or more at which the polymerizable monomer composition is solidified, the increase in the degree of polymerization slows down and the polymerization rate decreases. When the conversion is 95% or more, it becomes very slow. The polymerization reaction was allowed to proceed as it was, and the amount of the remaining polymerizable monomer was reduced to 1,
The operation may be performed so as to be not more than 000 ppm, but a known method for promoting the consumption of polymerizable monomers by a suspension polymerization method may be used.

As a method adopted in the method for producing the toner of the present invention, when the polymerization conversion reaches 95% or more, the liquid temperature of the aqueous medium is further raised by 20 to 60 ° C., and the viscosity due to heat is increased. Reduction, and there is a method of promoting the consumption of the polymerizable monomer by the initiation of thermal polymerization, at this time, if a polymerization initiator that decomposes at high temperature is allowed to coexist in the polymerizable monomer composition, it is effective The polymerizable monomer can be consumed.

Further, it is preferable that the unreacted polymerizable monomer and the organic solvent be distilled off under reduced pressure to reduce the residual amount to 1,000 ppm or less. By exposing the toner particles wetted with water to supersaturated steam while cooling the steam to 40 to 50 ° C., the residual amounts of the polymerizable vinyl monomer and the organic solvent can be reduced to 1,000 ppm or less. .

In addition, as a method of increasing the polymerization rate to reduce the amount of the polymerizable monomer, an organic solvent is added to the polymerizable monomer composition, or the amount is such that the blocking resistance of the resulting toner is not deteriorated. A plasticizer is added to the polymerizable monomer composition to lower the viscosity of the polymer system.

As a method for removing the unreacted polymerizable monomer and the organic solvent, a highly volatile organic solvent which does not dissolve the binder resin of the toner particles but dissolves the polymerizable monomer or the organic solvent component is used. Washing method, a method of washing the toner particles with an acid or alkali, a foaming agent or a solvent component that does not dissolve the polymer is put into a polymer system, and the polymerizable monomer inside the toner particles by making the toner particles porous and There is a method of increasing the volatilization area of the organic solvent component. Since it is difficult to select a solvent to be used in consideration of the dissolution of the toner components and the persistence of the organic solvent, the method of volatilizing the polymerizable monomer and the organic solvent component under reduced pressure is most preferable.

Finally, at least 1000 ppm or less, a polymerizable monomer generated during fixing and its reaction residue,
Alternatively, in order to eliminate the unpleasant odor due to the solvent, more preferably 700 ppm or less (more preferably, 300 ppm
pm or less).

The polymerization conversion is measured by adding a polymerization inhibitor to 1 g of a suspension and dissolving the polymerization inhibitor in 4 ml of THF. Quantification of residual polymerizable monomer and residual organic solvent,
A solution prepared by dissolving 0.2 g of the toner in 4 ml of THF is used. The prepared sample was subjected to gas chromatography (G.
C. ) Is measured by the internal standard method under the following conditions.

G. C. Conditions Measuring device: Shimadzu GC-15A (with capillary) Carrier: N ₂ , 2 Kg / cm ² 50 ml / min. split ratio 1:60, linear velocity 30 mm / sec. Column: ULBON HR-1 50m x 0.25m
m Sample volume: 2 μl Labeled substance: toluene

Hereinafter, the present invention will be specifically described based on Examples and Comparative Examples.

[0057]

EXAMPLES Example 1 0.1 M Na ₃ PO ₄ was added to 709 parts by weight of ion-exchanged water.
After adding 451 parts by weight of the aqueous solution and heating to 60 ° C,
An aqueous medium in which fine particles of Ca ₃ (PO ₄ ) ₂ were dispersed was prepared by gradually adding 67.7 parts by weight of a 1.0 M CaCl ₂ aqueous solution.

170 parts by weight of styrene 30 parts by weight of n-butyl acrylate I. Pigment Blue 15: 3 10 parts by weight Styrene-butadiene block copolymer 3 parts by weight (15 wt% based on wax) [(Clearen 730L (Denki Kagaku Kogyo); styrene / butadiene copolymer weight ratio = 75 / 25) Weight average molecular weight 100,000; CH ₂ ＣＨCH-group abundance about 20% by weight] Paraffin wax (melting point 75 ° C) 20 parts by weight Metal di-t-butylsalicylate compound (negative charge controlling agent) 5 parts by weight

The above-mentioned material was heated to 60 ° C., and 2,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo).
, And the mixture was dispersed and dissolved. To this, 2,2′-azobis (2,4-dimethylvaleronitrile) as a polymerization initiator [half-life at a temperature of 60 ° C. = 140 mi]
n. 10 parts by weight and dimethyl-2,2′-azobisisobutyrate [half-life at a temperature of 60 ° C. = 1,27]
0 min. Half life at 80 ° C. = 80 mi
n. 1 part by weight was dissolved to prepare a polymerizable monomer composition.

The above polymerizable monomer composition was put into the aqueous medium, and the mixture was stirred at 60 ° C. under a N ₂ atmosphere at 10,000 rpm for 20 minutes using a TK homomixer.
A suspension droplet of toner particle size was granulated. Thereafter, the mixture was reacted at a temperature of 60 ° C. for 3 hours while stirring with a paddle stirring blade. At this point, the polymerization conversion was 90%. Thereafter, the reflux of the steam was stopped, the liquid temperature was raised to 80 ° C.,
Stirring was continued for hours. After completion of the reaction, the suspension was cooled, and hydrochloric acid was added to dissolve the fine particles of Ca ₃ (PO ₄ ) ₂ , followed by filtration.
After washing with water and drying, a polymerized toner having a weight average diameter of 8.2 μm was obtained. This polymerized toner was subjected to a degassing treatment at 45 ° C. under a reduced pressure of 50 mmHg for 12 hours. At this time, the content of the polymerizable monomer remaining in the toner was 150 ppm, and the content of the organic solvent was substantially 0 ppm.

The particle size distribution of the obtained polymer toner is sharp, and the particle size distribution is shown in Table 1.

The particle size distribution of the toner was measured using a Coulter counter as follows.

As a measuring device, Coulter Counter T
An interface (manufactured by Nikkaki) and a CX that output the number distribution and volume distribution using A-II type (manufactured by Coulter)
-1 Connect a personal computer (Canon),
As the electrolyte, a 1% aqueous NaCl solution was prepared using primary sodium chloride. The measuring method is 100 to 100
0.1 to 5 ml of an alkylbenzene sulfonate as a dispersant is added to 150 ml, and the measurement sample is further added to 2 to 20 m.
g was added. The electrolyte in which the sample is suspended is approximately 1
Perform a dispersion treatment for up to 3 minutes.
Using the A-II type, the particle size distribution of the particles of 2 to 40 μm was measured on the basis of the number, using a 100 μm aperture as the aperture.

0.8 g of hydrophobic fine silica powder was externally added to 100 g of the toner. Further, silica externally added toner 30
g and 570 g of a resin-coated magnetic ferrite carrier were mixed to obtain a two-component developer.

Using this two-component developer, an image was formed using a modified machine of a commercially available color copying machine (manufactured by CLC-500 Canon). The development condition was a development contrast of 320 V in an environment of 23 ° C./65% RH.

An external fixing device capable of changing the fixing temperature of the unfixed image on the transfer material which has just been developed and copied by a remodeling machine [a fluorine resin soft roller is used as a fixing roller, and a silicone rubber is used as a pressure roller] System roller, no silicone oil coating function].

The obtained image had no offset, and was excellent in fixability. This two-component developer is heated at a temperature of 3
The toner image was left in an environment of 5 ° C. for one month, and the image quality was the same as before the image was left.

Next, about 3 g of toner is placed in a 100 ml container having a diameter of about 5 cm, and the temperature is 45 ° C. and the relative humidity is about 60 ± 5%.
When the toner was passed through a 20 Messi (U.S.A.) sieve after leaving it for one day in the environment described above, it was confirmed that there was no residual agglomerate of the toner having a major axis of more than about 1 mm, and the toner had excellent blocking resistance. Was.

Comparative Example 1 In Example 1, the same state was maintained after 3 hours of the reaction, and after a total of 8 hours, when the polymerization conversion reached 99% or more, the toner was taken out, and the dispersant was washed and dried. Was performed.
At this time, the content of the remaining polymerizable monomer was 4,
000 ppm. A two-component developer was prepared using 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. But,
Styrene odor was emitted from around the fixing device. When this two-component developer was allowed to stand for one month in an environment of 35 ° C., the triboelectric charge of the toner was extremely reduced, and a toner image with much fog was formed.

Further, a blocking resistance test was carried out in the same manner as in Example 1. As a result, an aggregate of toner having a major axis exceeding 1 mm was found.

Example 2 As a styrene-butadiene block copolymer, a styrene-butadiene copolymer KR03 manufactured by Nippon Steel Chemical Co., Ltd.
[Styrene / butadiene copolymer weight ratio = 75/25;
Weight average molecular weight 200,000] A toner was prepared in the same manner as in Example 1 except that 4 parts by weight was used, and further subjected to a reduced pressure treatment. The content of the polymerizable monomer remaining in the obtained toner was 300 ppm, and the content of the organic solvent was substantially 0 ppm.

Example 3 3 parts by weight of styrene-methyl methacrylate-methacrylic acid (copolymerization weight ratio: 96: 3: 1; weight average molecular weight: 50,000, acid value: 20) were further added to the polymerizable monomer composition. A toner was prepared in the same manner as in Example 1 except for addition, and further subjected to a reduced pressure treatment. The content of the polymerizable monomer remaining in the obtained toner was 650 ppm, and the content of the organic solvent was substantially 0 ppm.

Example 4 A styrene-butadiene copolymer Asaflex 805 manufactured by Asahi Kasei Corporation (styrene / butadiene copolymer weight ratio = 80) was used as a styrene-butadiene block copolymer.
/ 20; weight average molecular weight 110,000) A toner was prepared in the same manner as in Example 1 except that 4 parts by weight was used, and subjected to a reduced pressure treatment. The content of the polymerizable monomer remaining in the obtained toner was 300 ppm, and the content of the organic solvent was substantially 0 ppm.

Comparative Example 2 A toner was prepared in the same manner as in Example 1 except that the styrene-butadiene block copolymer was not contained in the polymerizable monomer composition, and subjected to a pressure reduction treatment. The obtained toner has a wider particle size distribution than that of Example 1, and the content of the polymerizable monomer remaining in the toner is 4500 ppm.
Met.

A two-component developer was prepared in the same manner as in Example 1, and an image-drawing test was conducted. As a result, the developability and the offset resistance were clearly inferior to those of Example 1. Further, when a test of blocking resistance of the toner was performed in the same manner as in Example 1, a toner lump having a major axis exceeding 1 mm was confirmed.

Comparative Example 3 As a styrene-butadiene block copolymer, 3 parts by weight of Kaliflex TRKX138S (styrene / butadiene copolymer weight ratio = 40/60; weight average molecular weight 80,000) manufactured by Shell Chemical Co., Ltd. was used. Example 1 except that
A toner was prepared in the same manner as described above. The content of the polymerizable monomer remaining in the obtained toner was 4,200 ppm.

A two-component developer was prepared in the same manner as in Example 1, and an image-drawing test was conducted. As a result, the developability and the offset resistance were clearly inferior to those of Example 1.

Further, the toner was tested for blocking resistance in the same manner as in Example 1. As a result, agglomerated aggregates of toner having a major axis exceeding 1 mm were confirmed.

Table 1 below shows the average particle size and particle size distribution of the toners obtained in Examples 1, 2 and 3 and Comparative Examples 2 and 3.

[0080]

[Table 1]

The toners obtained in Comparative Examples 2 and 3 had a broad particle size distribution as compared with the toners obtained in Examples 1, 2 and 3.

COMPARATIVE EXAMPLE 4 The toner obtained in Comparative Example 3 was subjected to a reduced pressure treatment in the same manner as in Example 1 so that the content of the polymerizable monomer was 200 p.
pm toner was prepared.

Example 5 A toner was prepared in the same manner as in Example 1 except that 3 parts by weight of a styrene / butadiene random copolymer having a styrene / butadiene copolymer weight ratio of 75/25 was used.
Next, the toner was subjected to a decompression treatment. The content of the polymerizable monomer remaining in the obtained toner was 250 ppm, and the content of the organic solvent was substantially 0 ppm.

Table 2 below shows the test results and the like of Examples 1 to 5 and Comparative Examples 1 to 4.

[0085]

[Table 2]

[0086]

According to the present invention, the amount of the organic solvent component in the toner particles is regulated, and the styrene-diene copolymer having both the properties of the polymer and the wax is contained in the polymerizable monomer. Since the toner is dissolved and mixed, the toner has excellent offset resistance at the time of high-temperature fixing, and has excellent blocking resistance and low-temperature fixing property, and a toner having a sharp particle size distribution can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (72) Koji Inaba, Inventor Koji 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Makoto Shinbayashi 3-30-2, Shimomaruko 3-chome, Ota-ku, Tokyo G Inside Canon Inc. (72) Inventor Kazuyuki Miyano 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-61-110154 (JP, A) JP-A-3-80260 ( JP, A) JP-A-61-7848 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 9/08-9/087

Claims (13)

(57) [Claims] 1. A binder resin, a toner for developing electrostatic images having toner particles containing at least a colorant and a wax, the toner for the electrostatic image development, the polymerizable vinyl monomer or a polymerizable vinyl The content of the mixture of the monomer and the organic solvent is 1,000 ppm or less, and the toner particles have a copolymerizable weight ratio of the polymerizable vinyl monomer, styrene or styrene derivative and butadiene or isoprene of 95: Styrene which is 5 to 65:35
A mixture containing at least a diene copolymer, a colorant, a wax and a polymerization initiator is mixed to prepare a polymerizable monomer composition, and the polymerizable monomer composition is dispersed in an aqueous medium and granulated. And a colored resin particle produced by polymerizing a polymerizable vinyl monomer in an aqueous medium. 2. The electrostatic image developing device according to claim 1, wherein the wax contains 5 to 30% by weight based on the toner, and the styrene-butadiene copolymer contains 1 to 50% by weight based on the wax. toner. 3. The toner for developing an electrostatic charge image according to claim 1, wherein the polymerizable vinyl monomer is styrene, acrylate, methacrylate or a mixture thereof. 4. The styrene-diene copolymer is styrene-diene.
The toner according to any one of claims 1 to 3, wherein the toner is a butadiene copolymer, and the styrene-butadiene copolymer is a block copolymer of a polystyrene structural unit and a polybutadiene structural unit. 5. The styrene-diene copolymer is styrene-diene.
Butadiene copolymer, styrene-butadiene copolymer
Coalescence is CH _Two= CH-group having 5 to 60% by weight
Item 6. The toner for developing an electrostatic image according to any one of Items 1 to 4. 6. The electrostatic image developing toner according to claim 1, wherein the wax contains 5 to 30% by weight of the toner. 7. The toner according to claim 1, wherein the wax contains 5 to 30% by weight of the toner, and the styrene-diene copolymer contains 1 to 50% by weight based on the wax. For developing electrostatic images. 8. The electrostatic image developing toner according to claim 1, wherein the styrene-diene copolymer is unevenly distributed on the surface of the toner particles. 9. The toner for developing an electrostatic charge image according to claim 1, wherein the wax has a melting point of 50 to 90 ° C. 10. The electrostatic image developing toner according to claim 1, wherein the styrene-diene copolymer has a weight average molecular weight of 30,000 to 500,000. 11. The toner according to claim 1, wherein the content of the toner particles having a particle diameter of 16.0 μm or more is less than 2% by volume.
0. The toner for developing an electrostatic image according to any one of the above items 12. Styrene having a copolymerizable weight ratio of a polymerizable vinyl monomer, styrene or a styrene derivative and butadiene or isoprene of from 95: 5 to 65:35.
A mixture containing at least a diene copolymer, a colorant, a wax and a polymerization initiator is mixed to prepare a polymerizable monomer composition, and the polymerizable monomer composition is dispersed in an aqueous medium and granulated. A method for producing a toner for developing an electrostatic image , wherein toner particles are formed by polymerizing a polymerizable vinyl monomer in an aqueous medium , wherein the toner particles contain at least a binder resin, a colorant and a wax. The content of the mixture of the polymerizable vinyl monomer or the organic solvent and the polymerizable vinyl monomer is 1,
A method for producing a toner for developing an electrostatic image, wherein the toner content is not more than 000 ppm. 13. The method for producing a toner for developing an electrostatic charge image according to claim 12, wherein a vacuum degassing process is performed after the toner particles are generated.