JPH0784407A - Toner for electrostatic image development - Google Patents

Abstract

(57) [Summary] [Object] To provide a toner for developing an electrostatic charge image, which is fixed at a low temperature and has good granulation property and fluidity of the agent. [Structure] A toner for developing an electrostatic charge image, which comprises at least a polymerizable monomer, a colorant, a wax, a styrene-butadiene resin and a polyester resin, and is produced by a suspension polymerization method in an aqueous suspension. The toner contains 5 to 30 wt% of the toner, the styrene-butadiene resin contains 1 to 50 wt% of the wax, and the organic solvent and / or the polymerizable monomer content is 1,000 pp.
It is characterized by being m or less.

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 developing an electrostatic latent image.

[0002]

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

As a typical example of the electrophotographic method, many methods are known as described in, for example, US Pat. No. 2,297,691. In this electrophotographic method, generally, a photoconductive substance is used to form an electric latent image on a photoconductor by various means, and then the latent image is developed with a toner to form a toner image. Then, if necessary, this toner image is transferred to a transfer material such as paper, and then the toner image is fixed to the transfer material or the like by using heat, pressure, solvent vapor or the like to obtain a copy. Currently, a fixing method using heat is predominant in terms of fixing strength of a copy, ease of handling a transfer, and comfort of work. As a heat fixing method, there is a method using radiant heat such as a heat chamber method, but a so-called heat roller fixing method of pressing a heated roll-shaped heating member against a toner image to fix it has high thermal efficiency and high-speed compatibility. It is used in most machines due to its high safety. However,
Even though it is highly efficient, the energy used for heat melting occupies a considerable amount in the copier,
In addition, the so-called offset phenomenon, in which the toner adheres to the heat roll and directly stains the subsequent image due to direct contact with the melted toner image, and the so-called wrap-around phenomenon in which the toner to be fused around the heat roll is inevitable is inevitable. There is.

In recent years, high-speed copying and high image quality have been required for electrophotography.

Generally, as a method for producing a toner, a thermoplastic resin is mixed with a coloring agent such as dye / pigment and an additive such as a charge control agent by melting and uniformly dispersed, and then a fine pulverizer and a classifier are used. A method for producing a toner having a desired particle diameter is known.

In the toner obtained by the pulverization method, there is a limitation in adding a releasing material such as wax.
That is, in order to obtain a sufficient level of dispersibility of the releasing material, the releasing material should not be dissolved and become liquid at the kneading temperature with the resin, and the content of the releasing material should be about 5 parts by weight or less. To do. Due to such restrictions, there is a limit to the fixability of the toner by the pulverization method.

To solve the above problems, a suspension polymerization method toner containing a releasing agent such as wax has been proposed. In this suspension polymerization method, a polymerizable monomer and a colorant (and optionally a polymerization initiator, a cross-linking agent, a charge control agent and other additives) are uniformly dissolved or dispersed to form a monomer composition. After that, this monomer composition is dispersed in a continuous phase (for example, an aqueous phase) containing a dispersion stabilizer by using a suitable stirrer, and a polymerization reaction is simultaneously performed to obtain toner particles having a desired particle size. I will get it.

In this suspension polymerization method, since the droplets of the monomer composition are formed in a dispersion medium of water, which has a large polarity,
The component having a polar group contained in the monomer composition tends to exist in the surface layer portion which is the interface with the aqueous phase, and the non-polar component does not exist in the surface layer portion, which is a so-called pseudocapsule structure. By utilizing this characteristic of the manufacturing method, it is possible to contain a wax having a low melting point which cannot be used by other pulverization methods.

A toner produced by the polymerization method can have both anti-blocking properties and low-temperature fixing properties, which are contradictory properties, by encapsulating the wax having a low melting point. That is, by encapsulating the low-melting-point wax, the wax that melts at a low temperature improves the thermal conductivity in the toner without deteriorating the blocking resistance, and as a result, low-temperature fixing is possible. More preferably, since the wax melted at the time of fixing also functions as a releasing agent, it is possible to prevent high temperature offset without applying a releasing agent such as oil to the fixing roller.

However, when a large amount of low-melting wax is dissolved and dispersed in the monomer composition of the polymerized toner and granulated in an aqueous medium, the granulation becomes unstable as compared with a system containing no wax. It was confirmed that the particle size distribution of the toner tends to be broad.

Further, the inclusion of such a low melting point wax is required to increase the amount of the wax in order to improve the fixing property. In such a case, it is difficult to completely encapsulate the wax and the blocking performance is maintained to some extent, but the fluidity of the agent becomes poor. Regarding fluidity and cohesiveness of the agent, reactive polyester-containing polymerized toners are disclosed in JP-A-56-116042 and JP-A-56-161843, and saturated polyester-containing polymerized toners are disclosed in JP-A-60-238846. Is proposed.

However, even in these manufacturing methods,
When a large amount of low-melting wax is contained, the compatibility between the wax and the polyester is poor, so that granulation becomes unstable and the particle size distribution becomes broad.

[0013]

The present inventors have found that in suspension polymerization in an aqueous medium, the polymerization starts from the particle interface, the polar component is concentrated near the interface, and the nonpolar component is collected in the central part. Utilizing this, we developed a polymerized toner containing a large amount of wax components that could not be produced by a conventional toner production method that relies on kneading and pulverization, and obtained a toner that can be fixed at a low temperature.

However, the granulation property and the fluidity of the agent became slightly inferior.

In the suspension polymerization method, the amount of the polymerization initiator is 0.5 to 2 in the case of a styrene-acrylic vinyl polymerizable monomer.
When the polymerization temperature is set to 0% by weight and the half-life of the initiator is set to 0.5 to 30 hours, a toner composition usable as a thermal fixing toner can be obtained.

With this setting, if the polymerization conversion rate is 90% or more, the toner particles will not coalesce into a mochi even if the stirring is stopped. When the polymerization conversion rate reaches 97, 8%, the toner particles are taken out. When dried, the toner can be used as a toner without any problems.

However, if a large amount of low-temperature melting wax is contained in this polymerized toner system, a high-quality image can be obtained without any problem under normal circumstances, but if it is left in a high-temperature environment, it is remarkably developable. The phenomenon that the value decreases occurs.

An object of the present invention is to provide a color toner for developing an electrostatic charge image, which solves the above problems.

[0019]

The object of the present invention is to provide a suspension polymerization method in an aqueous suspension, which comprises at least a polymerizable monomer, a colorant, a wax, a styrene-butadiene resin and a polyester resin. In the toner for developing an electrostatic charge image produced by, the wax is contained in an amount of 5 to 3 with respect to the toner.
0 wt%, the styrene-butadiene resin is contained in the wax in an amount of 1 to 50 wt%, and an organic solvent and / or
Alternatively, it can be achieved when the content of the polymerizable monomer is 1,000 ppm or less.

The present invention is described in detail below.

As described above, according to the suspension polymerization method, the low molecular weight component and the nonpolar component in the polymer can be encapsulated in the central part of the toner particle. On the other hand, in the suspension polymerization method, the viscosity of the polymerizable monomer system increases as the polymerization reaction progresses, making it difficult for the radical species and the polymerizable monomer to move, leaving unreacted polymerizable monomer in the system. Easy to do. In the case of the toner by the usual pulverization method, the residual polymerizable monomer can be expelled by the heat applied during the production of the resin for the toner or during the melt kneading, but in the case of the suspension polymerization method toner which directly produces the toner. Since high heat cannot be applied, a large amount of the polymerizable monomer remains in the toner as compared with the normal pulverization method toner. If the toner obtained by this suspension polymerization method is left at a high temperature in the absence of water, when the unreacted polymerizable monomer gradually evaporates from the surface, low molecular weight components and nonpolar components inside That is, it is considered that the developability of the toner is deteriorated due to the fact that the low melting point wax is conveyed and left on the surface portion. In the toner, a trace amount of a volatile organic solvent component is present in addition to the polymerizable monomer, and the content of all solvent components including these is 1,0 at the time of producing the suspension polymerization toner.
By controlling the amount to be not more than 00 ppm, it was possible to obtain a toner that does not deteriorate even when left at high temperature while encapsulating a large amount of low melting point wax.

However, problems such as the above-mentioned granulation property and fluidity of the agent occurred here. Obtaining toner with fluidity and sharp particle size is indispensable for omission of classification process, developing property and high image quality, which are found in the pulverization method.
The present inventors have earnestly studied.

As a result, the styrene-budagen resin, which is a polymer having the opposite properties of the polymer component and the wax component, and the polyester resin in order to find the fluidity of the agent, are dissolved and mixed in the polymerizable monomer. According to the above, it was found that a fluidity of the agent is essential and a toner having a sharp particle size can be obtained.

The reason for the effect is suggested to be that the styrene-budagen resin has an action of alleviating the phase separation from the polymer component in the wax polymerization process in the granulation process, but its details are unknown.

The styrene-butadiene resin used in the present invention may be any copolymer such as a graft copolymer, a block copolymer, etc., but it has a constitution capable of more effectively exhibiting the action of the present invention. As the above, a block copolymer is preferable.

Further, as a constitution capable of effectively exhibiting the action of the present invention, the copolymerization ratio of styrene and butadiene is 95:
It is preferably 5 to 65:35. Here, if the styrene ratio exceeds 95%, no effect is seen on the granulation property, while if it is less than several%, the granulation property and toner blocking property deteriorate. It is considered that the reduction in the effect due to the styrene-butadiene copolymerization ratio indicates that the compatibility of the compatibility between the polymer component and the wax component is required.

Further, the reason why the block copolymer is more effective is considered to be that the compatible component segment for each phase is secured at a certain ratio.

The addition amount of the styrene-butadiene resin in the present invention is preferably 1 to 50 wt% with respect to the wax. If the styrene-butadiene resin is less than 1 wt% with respect to the wax, no effect is seen on the granulation property, while if it exceeds 50 wt%, the blocking property and fluidity of the toner deteriorate.

Examples of the wax used in the present invention include paraffin and polyolefin wax.
When the paraffin wax is used, the effect of the present invention can be exhibited more highly. The reason why the paraffin wax is selected is that it is highly soluble in the polymerizable monomer. The melting point of the wax is preferably 50 to 90 ° C., and lower temperature fixing can be achieved.

The feature of the present invention resides in that it further contains a polyester resin, but when it is used alone, the granulating property tends to be further deteriorated. When used in combination with the styrene-butadiene resin, the fluidity of the agent and the granulating property are improved. At the same time, the sex partner can be satisfied.

The reason for this is that the toner surface layer is formed of polyester, and as a result, the fluidity of the agent is ensured, and further, the styrene-butadiene copolymerization is used as a function of alleviating the phase separation tendency of the wax in the monomer system due to the addition of polyester. It is thought that coalescence will work.

The polyester resin used in the present invention is an unsaturated polyester, and is 0.1 to the polymerizable monomer.
It is preferable to contain 10 to 10 wt%. If less than 0.1 wt% is added to the polymerized monomer, the fluidity of the agent cannot be secured, and if more than 10 wt%, the granulating property in the wax-containing system deteriorates.

Further, the polyester of the present invention is 40-60.
mol% etherified diphenol component and 10-40
A divalent carboxylic acid or its derivative component substituted with mol% of C _{6 to} C ₁₆ hydrocarbon groups, and 1 to 1 of the total amount of monomers.
It is preferable to contain at least 20 wt% of trivalent or higher polycarboxylic acid or / and polyols or their derivatives.

The present inventors have found that the polyester having this composition has good toner fluidity, developability, chargeability and environmental stability, but the reason for the effect is not clear.

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

Examples of the polymerizable monomer include styrene-based monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-ethylstyrene, methyl acrylate, and acrylic acid. Such as 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 methacrylic acid esters such as 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, and other monomers such as acrylonitrile, methacrylonitrile, and acrylamide.

These monomers may 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 other monomers, from the viewpoint of developing characteristics and durability of the toner.

In the present invention, in addition to the styrene-butadiene resin and the polyester resin, a resin may be added to the monomer system for polymerization. For example, a monomer is water-soluble and cannot be used because it dissolves in an aqueous suspension to cause emulsion polymerization, and thus cannot be used as a hydrophilic functional group such as an amino group, a carboxylic acid group, a hydroxyl group, a sulfonic acid group, a glycidyl group, or a nitrile group. When it is desired to introduce the monomer component of the above into the toner, it is made into a copolymer such as a random copolymer, a block copolymer, or a graft copolymer of these and a vinyl compound such as styrene or ethylene, or polyamide. It can be used in the form of a polycondensate such as polyether, a polyaddition polymer such as polyether or polyimine. When such a high molecular polymer containing a polar functional group is coexisted in the toner, the wax component is phase-separated, the inclusion becomes stronger, and the performance of the toner intended by the present invention is improved. desirable. The amount used is preferably 1 to 20 wt%. The average molecular weight of the high molecular weight polymer containing these polar functional groups is 5,0.
00 or more is preferably used. When it is 5,000 or less, particularly 4,000 or less, the present polymer tends to concentrate near the surface, which is unfavorable since it tends to adversely affect the developability and blocking resistance. Further, 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. I can.

As the coloring agent used in the present invention, known coloring agents can be used, such as carbon black, iron black, C.I. I.
Direct Red 1, C.I. I. Basic Red 1,
C. I. Mordant 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, Yellow Lead, 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, Alkali 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, since a toner is obtained by using a polymerization method, it is necessary to pay attention to the polymerization inhibitory property and the water phase transfer property of the colorant, preferably surface modification,
For example, it is better to perform a hydrophobic treatment with a substance that does not inhibit polymerization. In particular, since many dyes and carbon black have a polymerization inhibitory property, caution is required when using them. As a preferred method of surface-treating a dye system, a method of previously polymerizing a polymerizable monomer in the presence of these dyes can be mentioned.

Regarding carbon black, in addition to the same treatment as for the dye, it is also possible to carry out a grafting treatment with a substance that reacts with the surface functional groups of carbon black, such as polyorganosiloxane or polyethylene glycol. Although few other pigments have a stronger polymerization inhibiting effect than carbon black, it is better to perform the same treatment in consideration of dispersion in a polymerizable monomer.

A magnetic toner may be added by adding a magnetic material.

A charge control agent may be blended in the toner according to the present invention in order to stabilize the charge characteristics, and a colorless or pale color 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 at the time of the polymerization reaction, and the polymerization reaction is carried out with the addition amount of 0.5 to 20% by weight of the polymerizable monomer. Thus, a polymer having a maximum in the molecular weight of 10,000 to 100,000 can be obtained, and the toner can be provided with desired strength and proper melting characteristics. Examples of the polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile) and 2,2′-
Azo such as azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile -Based or diazo-based polymerization initiators, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-
Examples thereof include peroxide type polymerization initiators such as dichlorobenzoyl peroxide and lauroyl peroxide.

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

In the toner manufacturing method of the present invention, generally, the above-mentioned toner composition, that is, a colorant, a releasing agent, a plasticizer, a binder, a charge control agent, a cross-linking agent, a magnetic substance, etc., in the polymerizable monomer. Components necessary as a toner and other additives, for example, an organic solvent, which is added to reduce the viscosity of the polymer produced in the polymerization reaction, a dispersant, etc. are appropriately added, and a homogenizer,
The monomer system uniformly dissolved or dispersed by a dispersing machine such as a ball mill, a colloid mill or an ultrasonic dispersing machine 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 stirrer or a high-speed disperser such as an ultrasonic disperser to immediately make the desired toner particle size. Regarding the timing of addition of the polymerization initiator, it may be added at the same time when other additives are added to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. It is also possible to add a polymerization initiator dissolved in a polymerizable monomer or a solvent immediately after granulation and before starting the polymerization reaction.

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

In the suspension polymerization method of the present invention, known surfactants and organic / inorganic dispersants can be used as dispersion stabilizers. Among them, the inorganic dispersants are unlikely to produce harmful ultrafine powders, and due to their steric hindrance. Since the dispersion stability is obtained, the stability is not easily deteriorated even when the reaction temperature is changed, the washing is easy, and the toner is not adversely affected, and therefore it is preferably used. Examples of such inorganic dispersants include calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, and other polyvalent metal salts of phosphates, calcium carbonate, carbonates such as magnesium carbonate, calcium meta silicate, calcium sulfate, and barium sulfate. Examples thereof include inorganic salts, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite, and inorganic oxides such as alumina.

These inorganic dispersants are composed of the polymerizable monomer 10
It is desirable to use 0.2 to 20 parts by weight per 0 parts by weight, but it is difficult to generate ultrafine particles, but it is somewhat difficult to atomize the toner, so 0.001 to 0.1 parts by weight Some surfactants may be used together.

Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate,
Examples thereof 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 generated 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 is possible. At this time, a water-soluble sodium chloride salt is by-produced at the same time, but when the water-soluble salt is present in the aqueous medium, the dissolution of the polymerizable monomer in water is suppressed, and the ultrafine toner particles due to emulsion polymerization are generated. It is more convenient because it is less likely to occur. Since it becomes an obstacle when removing the remaining polymerizable monomer at the end of the polymerization reaction, it is better to replace the aqueous medium or desalt with an ion exchange resin. The inorganic dispersant can be almost completely removed by dissolving it with an acid or an alkali after completion of the polymerization.

In the polymerization step, the polymerization temperature is 40
Polymerization is carried out at a temperature of not lower than 0 ° C, generally 50 to 90 ° C. When the polymerization is carried out within this temperature range, the release agent and waxes to be sealed inside are precipitated by phase separation and the encapsulation becomes more complete. At the end of the polymerization reaction, the reaction temperature is set to 90 to consume the remaining polymerizable monomer.
It is possible to raise it to 150 ° C.

Under the above conditions, the conversion rate increases almost linearly up to the polymerization conversion rate of 90%, but the toner solidifies 90
%, The increase in the degree of polymerization is slow, and when the polymerization conversion rate is 95% or more, it is very slow. The polymerization reaction may proceed as it is, and the amount of residual polymerizable monomer may be controlled to 1,000 ppm or less, but a known means for promoting the consumption of polymerizable monomer in the conventional suspension polymerization method can be used.

The means adopted in the method for producing a polymerized toner of the present invention include, when the polymerization conversion rate reaches 95% or more, raising the temperature by 20 to 60 ° C. to reduce the viscosity due to heat, and the initiation of thermal polymerization. Therefore, the consumption of the polymerizable monomer is promoted. At this time, if a polymerization initiator that decomposes at high temperature is allowed to coexist in the polymer system, the consumption of the polymerizable monomer is effectively performed.

Further, the reflux is stopped or the pressure is reduced to partially distill off the unreacted polymerizable monomer and / or the organic solvent so that the residual amount is 1,000 ppm or less. In terms of Instead of keeping it in water, for example while cooling the water vapor to 40-50 ° C,
By exposing the toner particles moistened with water to supersaturated water vapor, the residual amount can be reduced to 1,000 ppm or less while leaving the same effect as being retained in water.

In addition to this, as a method of increasing the polymerization addition rate and consuming the polymerizable monomer, an organic solvent which is a solvent of the toner is added to the polymer system, and a plasticizer is added to the extent that the blocking resistance of the toner is not deteriorated. There is a method of decreasing the viscosity of the polymer system by, for example, adding an amount to the polymer system.

As a method of removing the unreacted polymerizable monomer and / or the organic solvent, the toner binder resin is not dissolved but the polymerizable monomer and / or the organic solvent component is dissolved. A method of washing with an organic solvent, a method of washing with an acid or an alkali, a solvent component that does not dissolve a foaming agent or a polymer is added to a polymer system, and a polymerizable monomer inside by making the obtained toner porous, and Alternatively, there is a method of increasing the volatilization area of the organic solvent component, but since it is difficult to select the solvent such as the elution of the toner constituents and the residual property of the solvent, the polymerizable monomer and / or the organic solvent component are volatilized under reduced pressure. How to make
Most preferred.

Finally, at least 1000 ppm or less, the polymerizable monomer generated during fixing and its reaction residue,
Alternatively, it is more preferably 100 ppm or less in order to eliminate the offensive odor caused by the solvent.

The polymerization conversion rate was obtained by adding a polymerization inhibitor to 1 g of the suspension and dissolving it in 4 ml of THF. The amount of the residual polymerizable monomer and the residual organic solvent was 0.2 g of the toner. Those dissolved in 4 ml of THF were measured by gas chromatography by the internal standard method under the following conditions.

G. C. Conditions Measuring apparatus: Shimadzu GC-15A (with a capillary) ^{_{Carrier: N 2, 2Kg / cm 2}} 50ml / min.
Split ratio 1:60, linear velocity 30 mm / sec. Column: ULBON HR-1 50m x 0.25m
m Sample amount: 2 μl Labeled substance: Toluene Hereinafter, the present invention will be specifically described based on Examples and Comparative Examples.

[0060]

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

Styrene 170 g n-Butyl acrylate 30 g C.I. I. Pigment Blue 15: 3 10 g Styrene-butadiene copolymer 3 g (15 wt% with respect to wax) [Clearene 730 L (manufactured by Denki Kagaku Kogyo), St / Buta = 75/25] Paraffin wax (mp. 75 ° C.) 20 g di- t-Butylsalicylic acid metal compound 5 g Polyester resin 2 g The above formulation was heated to 60 ° C. and uniformly dispersed and dissolved at 12,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). In addition, 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., t 1/2 = 80 min. at 80 ° C] 1
g was dissolved and a polymerizable monomer system was prepared.

The above polymerizable monomer system was added to the above aqueous medium and stirred at 60 ° C. under N ₂ atmosphere with a TK type homomixer at 8,000 rpm for 15 minutes to form suspension droplets of toner particle size. Granulated. Then, the mixture was reacted at 60 ° C. for 3 hours while stirring with a paddle stirring blade. The polymerization conversion rate at this point was 90%. Then, the reflux of water vapor was stopped, the liquid temperature was raised to 80 ° C., and stirring was continued for 10 hours.
After the reaction was completed, 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 =
A polymerized toner of 8.7 μm was obtained. This toner at 45 ° C,
The degassing treatment was performed for 12 hours under a reduced pressure of 50 mmHg. The amount of the polymerizable monomer remaining at this point is 150.
It was ppm.

The particle size distribution of the obtained toner became sharp. The particle size distribution is shown in Table 2.

The fluidity of the agent was also good.
The particle size distribution was measured by the following method.

That is, a Coulter Counter TA-II type (manufactured by Coulter) is used as a measuring device, and an interface (manufactured by Nikkaki) for outputting number distribution and volume distribution.
And CX-1 personal computer (made by Canon) are connected, and electrolyte is 1% Na using primary sodium chloride.
An aqueous Cl solution is prepared. As a measuring method, a surfactant, preferably an alkylbenzene sulfonate, as a dispersant is added to 100 to 150 ml of the electrolytic aqueous solution in an amount of 0.1 to 5 m.
1 and 2 to 20 mg of the measurement sample are further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and is subjected to a Coulter Counter TA-II type,
Using a 100 μm aperture as an aperture, the particle size distribution of particles of 2 to 40 μm was measured based on the number.

0.6 g of hydrophobic silica was externally added to 100 g of the polymerized toner. Furthermore, this silica external additive 30
and 570 g of resin-coated ferrite carrier were mixed to prepare a two-component developer.

Using this developer, images were printed using a commercially available color copying machine (CLC-500, manufactured by Canon) remodeling machine. The developing condition was a developing contrast of 320 V under the environment of 23 ° C./65%.

An unfixed image on the above copy just developed and copied by a modified machine of CLC-500 is an external fixing machine (a fixing roller is a fluorine type soft roller and a pressure roller is a silicon type roller (oil coating). Fixed))). The obtained fixed image had excellent fixability without offset. Also,
The developer was left in an environment of 35 ° C. for one month, and the image quality was the same as that in the initial stage.

Comparative Example 1 In Example 1, the same state was maintained after 3 hours of 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 done.
At this point, the amount of residual polymerizable monomer was 4,300 ppm. When this toner was adjusted in the same manner as in Example 1 by adjusting the developer and image formation was performed, a good image was obtained, which was the same as in Example 1. However, there was a styrene odor from around the fixing device. When this toner was left in an environment of 35 ° C. for one month, the toner tribo was extremely reduced, and an image with a lot of fog was formed.

Examples 2-4 and Comparative Examples 2-5 In Example 1, toners having different wax contents and residual polymerizable monomers were produced and evaluated.

Table 1 lists the details. Table 2 shows the particle size distribution in granulation.

[0072]

[Table 1]

[0073]

[Table 2] In terms of granulation, emulsion stability, interfacial tension,
And the dispersibility of pigments and the like is greatly involved. Furthermore, in pigment dispersibility, additives, resins,
Compatibility with wax and the like is important.

From this viewpoint, the interfacial tension of the system was measured in Example 1 and Comparative Examples 2 and 5, and the results are shown in Table 3. Table 3 also shows the dispersibility of the pigment during granulation. The pigment dispersibility was visually determined with a microscope. It is clear from Table 3 that the decrease in pigment dispersibility and the decrease in interfacial tension are the factors for judging the granulation property.

[0075]

[Table 3]

[0076]

According to the present invention, in the suspension polymerization toner,
Since it contains a styrene-butadiene resin and a polyester resin, the granulating property and the fluidity of the agent are improved,
A high quality fixed image is obtained.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁶ Identification number Internal reference number FI Technical indication point 365 (72) Inventor Tatsuya Nakamura 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. ( 72) Inventor Makoto Kamibayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kazuyuki Miyano 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (4)

[Claims] 1. A toner for developing an electrostatic charge image, which comprises at least a polymerizable monomer, a colorant, a wax, a styrene-butadiene resin and a polyester resin, and is produced by a suspension polymerization method in an aqueous suspension, The wax is contained in the toner in an amount of 5 to 30 wt%, the styrene-butadiene resin is included in the wax in an amount of 1 to 50 wt%, and the organic solvent and / or the polymerizable monomer content is 1,000 p.
A toner for developing an electrostatic charge image, which has a pm or less. 2. The polyester resin is an unsaturated polyester, and is 0.1 to 1.0 wt% with respect to the polymerizable monomer.
The toner for developing an electrostatic charge image according to claim 1, wherein the toner contains the toner. 3. The styrene-butadiene resin is a block copolymer resin, and the ratio of styrene to butadiene is 95: 5 to 65:35.
Or the toner for developing an electrostatic image according to item 2. 4. The toner for developing an electrostatic charge image according to claim 1, wherein the wax is a paraffin wax and has a melting point of 50 to 90 ° C.