JPH0778645B2 - Microcapsule toner and manufacturing method thereof - Google Patents

Description

The present invention relates to a microcapsule toner for developing an electrostatic charge image in an image forming method such as electrophotography, electrostatic recording and electrostatic printing, and a method for producing the same. .

[Prior Art] Conventionally, as an electrophotographic method, many methods are known as described in US Pat. No. 2,297,691, JP-B-42-23910 and JP-B-43-24748. . 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, and a toner image is formed on a transfer material such as paper if necessary. After transfer, the image is fixed by heating, pressure, heating and pressurizing, or solvent vapor to obtain a copy.

In recent years, as a copying machine, a mono-color copying machine, a two-color copying machine, and a full-color copying machine have been studied and put into practical use.

Further, due to the efficiency of copying work, energy saving, downsizing and speeding up of copying machines, a low temperature fixing toner capable of fixing with a lower heat quantity and a pressure fixing toner capable of fixing at a lower temperature have been studied. There is.

Most of copying machines in recent years employ a heat roll type fixing system. This is to fix the toner on the paper by thermocompression bonding with a heating roller.

In such a thermocompression bonding method, as compared with a non-contact type heating method using heat rays, it is possible to obtain a good fixed image by using a lower temperature heating element, and it is possible to achieve higher speed. This method also has some problems. As one of the big ones, if the heat roller is kept at a temperature at which the toner is sufficiently fixed to a holding member such as paper, the toner is fused not only on the paper but also on the heat roll, which causes copying. There is a problem that the heat roll is soiled as the process is repeated. Such a fused toner on the heat roll cannot be sufficiently removed by a blade or a cleaning web for keeping the heat roll clean, and eventually the paper is also soiled (so-called high temperature offset),
Cause problems.

In order to solve or reduce the problem of such offset,
Various measures have been tried from both the fixing device and toner sides, but further improvement is desired.

For example, attempts have been made to improve the binder resin of toner. For example, in Japanese Examined Patent Publication No. 51-23354,
A toner using a crosslinked polymer (mainly a styrene resin) as a binder resin has been proposed. According to this method, the offset resistance and the sticking resistance of the toner are improved, but the fixing point (temperature) of the toner rises when the degree of crosslinking is increased. Such an increase in the fixing point of the toner deteriorates the image quality of the image, particularly when a color copy is obtained using the toner of each color. Not only the gloss and luster of the image, which are important characteristics for color copying, are lost, but also the color reproducibility of the color tone deteriorates.

Further, such a crosslinked polymer has a problem that the dispersibility of a colorant such as a pigment and / or a charge control agent is poor, and there is a problem of developability due to the influence of the colorant.

JP-A-58-106554 proposes a method of coating monodisperse spherical core particles with a polymer substance containing a colorant. One of them is a method of coating a polymer substance and a colorant by adding monodispersed spherical core particles to a solution such as dissolved or dispersed cyclohexane or methanol and removing the solvent.

Such a method requires a fairly low amount of polymeric material in the solvent to obtain a good coating, requires equipment for solvent removal, and is costly.
It is technically difficult to avoid agglomeration of particles at the stage when the solution is concentrated, and requires special measures and crushing of agglomerates. Further, the solvent must not dissolve the core and must dissolve the coating polymer substance, which greatly limits the materials of the core particle and the coating polymer substance.

As another method, a method of coating with a dispersion liquid (mainly an aqueous dispersion liquid) in which a polymer substance and a colorant are dispersed is proposed. This method requires a device for removing water, as in the method using a solvent, and is costly. It is technically difficult to avoid agglomeration of particles at the stage when the dispersion is concentrated. Furthermore, it is necessary to disperse the core particles in water, and an auxiliary material such as an emulsifier is required to disperse the highly hydrophobic core particles. In general, such an emulsifier is a hydrophilic substance, which deteriorates triboelectric chargeability in a highly insulating toner, and has a bad influence particularly under high humidity. Therefore, the emulsifier needs to be removed, but it is technically difficult to avoid using it.

As another method, there has been proposed a method in which a powder of a polymer substance or a colorant is used to melt and coat the powder by heating. In such a method, as described in the text, it is necessary to adjust the temperature to a temperature low enough to avoid thermal agglomeration of the core particles as much as possible and to a temperature high enough to bond the polymer substance as the coating substance. It is described that this temperature control is important. This is intended to prevent mutual fusion of core particles due to heat. The toner used in the electrophotographic method is a toner in which a toner image is transferred onto a transfer material such as paper and then fixed by heating, pressure or heating / pressurizing to obtain a copy, which is melted by heat and pressure in the fixing step. Because of the necessity to do so, a thermoplastic resin is mainly used as the material of the core particles, and when the polymer material as the coating material is heated and melted, the core particles are heated to some extent.

When the polymer substance is entirely attached to the surface of the core particle, when the polymer substance is heated and adhered to form the outer shell, the core substance is present due to the presence of the polymer substance even if the core particle is melted by heat. Although the aggregation of particles can be prevented to some extent,
In the case of a partially adhered state, it is difficult to prevent thermal agglomeration of the core particles due to thermal melting of the core particles, and it is technically difficult to obtain a partially coated toner.

In JP-A-61-210368, a resin for a binder and a colorant are dispersed on the surface of spherical particles using a mixer such as a Henschel mixer and a super mixer, and the dispersion temperature is lower than the softening point of the spherical particles and lower than the softening point of the binder resin. Also, a method of immobilizing by treatment at a high temperature has been proposed. This method has a material limitation that the binder resin is lower than the softening point of the spherical particles. When heat treatment is performed at a temperature of 110 ° C. to 140 ° C. for 10 minutes as shown in the examples, it is technically difficult to avoid cohesive fusion of spherical particles due to heat, and it is considered that thermal deterioration may occur depending on the material used. However, it cannot be said that the problem has been solved sufficiently.

As described above, a color toner having sufficient high-temperature offset resistance and releasability with respect to a heat fixing roller, and having a wide color reproducibility that provides particularly good developability as a color image and appropriate gloss. Is not yet obtained.

Usually, the toner particles are composed of materials such as a binder resin, a colorant, a charge control agent, and a release agent. In the method of producing a toner by a pulverization method, these materials are mixed, melt-kneaded by a kneader such as a roll mill, and then pulverized by a pulverizer such as a cutter mill, a pin mill or a jet mill to form fine particles. At this time, various materials may be present on the surface of the toner particles. For example, when a colorant appears on the surface of the toner, it deteriorates the charging property and increases the adsorption of water, thereby deteriorating the developability of the toner. The colorant released during pulverization contaminates the carrier or the developing sleeve. Binder resins and waxes having a low melting point used for low-temperature fixing toners and pressure fixing toners are preferable for fixing properties, but are not preferable for blocking resistance and durability of toners, which are contradictory properties.

As a toner form for solving such problems,
The particle morphology of microcapsule type toners such as those found in US Pat. No. 4,016,099 and US Pat. No. 3,788,994 is contemplated. The microcapsule type toner is a toner in which core particles containing a material such as a binder resin and a colorant are wrapped with a film called a hard shell having a role of protecting the core particles and having a chargeable function. The particles having such a form can cover the problems of the binder resin and the colorant. Many proposals have been made regarding such microcapsule toners.

As a method for producing the microcapsule toner, methods such as a spray drying method, an interfacial polymerization method, a coacervation method, a phase separation method and an in-situ polymerization method are known. However, a preferable microcapsule toner is not easily obtained by the above manufacturing method using a material having a preferable function. In many cases, imperfections in film formation,
There is a problem of unification of the microcapsule toner during manufacturing and manufacturing cost. A binder resin mainly composed of a wax-like substance is used as the core material of the microcapsule toner used in the pressure fixing method, but it is very difficult to disperse the colorant in the wax-like substance, and a color with wide color reproducibility is obtained. It is difficult to manufacture toner.

The toner or microcapsule toner can be charged by a charge injection method in which the toner is made conductive to inject an electric charge, a dielectric polarization method that uses dielectric polarization under an electric field, or an ion flow in which a shower of charged ions is applied to particles by a corona charger. There is a charging method and a triboelectric charging method in which the toner is charged by rubbing an object and a toner at a position having a different triboelectric charging series. Among them, the triboelectrification method is widely used at present because it can be adjusted to a sufficient charge amount by using insulating toner particles and has reproducibility. However, since the frictional band charge is proportional to the frictional work, it is impossible to keep the frictional work of the toner particles constant in practical development. It is easily affected by humidity.

If the rise of the frictional band charge is improved, its absolute amount tends to be large, and in particular in a low humidity environment, it becomes necessary to create a large electric field to transfer the toner particles to the latent image surface due to the excessive charge amount, This will impose a burden on the system and the risk of electric discharge due to dielectric breakdown. on the other hand,
When the absolute amount of charge is suppressed, it takes time to have a sufficient amount of charge, especially in a high humidity environment, and it is impossible to exclude particles that adhere to the latent image portion by a force other than electric force, It causes an obstacle to stain the image. Such a phenomenon is caused by a binder resin having a high insulating property other than a slight amount of a colorant, such as a color toner, or a core particle covered with a highly insulating outer shell like a capsule toner. Then
On the other hand, on the other hand, a magnetic toner in which a magnetic material is dispersed to give magnetism is relatively weak.

In the case of magnetic toner, the magnetic substance has a lower resistance than that of the binder resin, and it seems that excess charges are released from the magnetic substance. These are found not only in magnetic materials, but also in other metal oxides and powders, semiconductors such as carbon black or conductors, low molecular weight organic compounds such as dyes and pigments, and surfactants. These materials can obtain the antistatic effect (leak effect) even in the toner particles whose surface is composed of only the highly insulating binder.

The internal addition of such an antistatic substance changes the required physical properties and coloring properties of the toner particles and requires a large amount. Therefore, the external addition of fine particles of the antistatic substance to the toner is small. It is effective and has few obstacles. However, the developing properties of the toner particles and the externally added antistatic particles are greatly different by simply mixing, and when the developing operation is repeated, the composition ratio of the toner and the antistatic substance in the developer changes. , The developing characteristics of the developer may change.

After the toner particle image on the latent image surface is transferred to another adherend, the latent image surface is cleaned, and in a system that is used repeatedly, antistatic substances are not transferred but remain on the latent image surface and gradually accumulate at the cleaning site. Some objects may cause scratches on the latent image surface or the cleaning member. Therefore, it is necessary that the antistatic fine particles are definitely fixed on the toner surface.

Conventionally, there has been a problem of image deletion due to fusing of a toner to a photoconductor or adhesion of a low resistance substance such as paper dust due to friction between the photoconductor and a cleaning blade under high temperature and high humidity.

Conventionally, fatty acid metal salts are used from the viewpoint of facilitating cleaning of low-resistance substances such as toner or paper powder from the photoconductor in order to prevent the phenomenon of image deletion under high temperature and high humidity and toner fusion to the photoconductor. A method is known in which a lubricating fine powder such as PVdF or PVdF is added to a toner and mixed.

A method is known in which an abrasive such as CeO ₂ is mixed (externally added) with the toner from the viewpoint of imparting an excessive abrasive force to the toner and always appropriately abrading the surface of the photoreceptor during cleaning. However, these methods only electrostatically attach the fine powder to the toner surface, failing to control the abrasiveness of the toner main body, and in addition, a considerably large amount of addition is required, Often interferes with the chargeability of the toner. Due to electrostatic adhesion, the toner and the fine powder are separated in the developing process, and at that time, the opposite charge is generated due to friction between the surfaces of the opposite sides, so it is necessary to pay sufficient attention to the charging series of the conventionally added fine powder. And the ones that can be used are extremely limited.

Generally, in toner, it is known that the abrasiveness greatly varies depending on the molecular weight and gel content of the binder, the amount and shape of the magnetic material, the type and dispersion state of the polyalkylene,
Of course, it is possible to control the abrasiveness of the toner itself. However, if such a toner design is performed, there is a case where a developing process, a transfer process, or a fixing process (development failure, transfer failure, offset etc.) causes a trouble. Conventionally, such development, transfer, since the importance of avoiding troubles in the fixing process, the control of the abrasiveness of the toner itself is limited, and it is inevitable to rely on the addition and mixing of a lubricant and an abrasive, As a result, the design latitude of the photoconductor cleaning process of the copying machine is narrowed.

Conventionally, a substance called a charge control agent has been generally added in order to impart sufficient triboelectric chargeability to the toner.

Charge control agents known in the art today include nigrosine, azine dyes, quaternary ammonium salts, and the like, which control the toner to have a positive charge property. On the other hand, there are metal complex salts of monoazo dyes and metal complexes of salicylic acid Co, Cr or Fe as those for controlling the toner to be negatively charged. These are usually added to a thermoplastic resin, thermally melt-dispersed, finely pulverized and adjusted to an appropriate particle size as needed, and used.

However, since it is difficult to uniformly disperse these charge control agents in the thermoplastic resin, there is a problem in that the triboelectric charge amount between toner particles obtained by pulverization is different. Therefore, various methods have been conventionally used to make the dispersion more uniform. For example, a basic nigrosine dye is used as a higher fatty acid complex in order to improve the compatibility with a thermoplastic resin, but unreacted fatty acid or a salt dispersion product is often exposed on the toner surface. And contaminate the carrier or toner carrier. This causes a decrease in the fluidity of the toner, a fog, or a decrease in the image density. on the other hand,
In order to improve the dispersibility of the charge control agent in the resin, a method of mechanically pulverizing and mixing the charge control agent and the resin powder in advance and then hot-melt kneading is used. However, the original poor dispersion cannot be avoided, and under the present circumstances, improvement for obtaining a sufficient amount of charge uniformly is desired.

[Object of the Invention] An object of the present invention is to provide a microcapsule toner and a method for producing the microcapsule toner, which solves the above problems of the toner.

An object of the present invention is to provide a microcapsule toner in which carrier contamination by a colorant is suppressed or suppressed, and a method for producing the same. An object of the present invention is to provide a method for producing a microcapsule toner having good fixability, good durability, and good storage stability without blocking. An object of the present invention is to provide a microcapsule toner having good chargeability and sufficient developability, and a method for producing the same. An object of the present invention is to provide a microcapsule toner for electrophotography which gives a color copy image having sufficient gloss and luster, and a method for producing the same.

INDUSTRIAL APPLICABILITY The present invention has a good rise of the charge of the triboelectric insulating microcapsule toner and does not become excessively charged.
A microcapsule toner with self-static properties that is improved so that the charge amount does not become unstable due to environmental differences during repeated use and does not damage the photoreceptor or cleaner in a system that is used repeatedly. It is provided.

An object of the present invention is to provide a microcapsule toner by a dry method which prevents a film formation phenomenon on a photoconductor, exhibits a good charging property with time, and gives a stable and good image, and a method for producing the same. .

Further, an object of the present invention is to provide a method for producing a microcapsule toner for fixing on a heat roller, which has good chargeability and always shows stable chargeability during use, and which gives a clear and fog-free image. is there.

[Outline of the Invention] Specifically, in the present invention, in a microcapsule toner having core particles and an outer shell, particles (A1) having at least a binder resin and particles of 0.2 or less with respect to the particles (A1). The particles (B) having a diameter ratio (however, the particles (B) are colored particles, antistatic particles or abrasive particles) are mixed at an ambient temperature of 10
Formed from a rotating piece and a fixed piece under the condition of ~ 90 ℃ 0.5
A particle having a shortest gap of ˜5 mm or a shock portion having a shortest gap of 0.5-5 mm formed from at least two kinds of rotating pieces and passing through a mechanical impact in the impact part to the surface of the particle (A1). (B) is immobilized to form particles (A2), and outer shell forming resin particles (C) having a particle size ratio of 0.2 or less with respect to the particles (A2) are heated under the conditions of an ambient temperature of 10 to 90 ° C. An impact part having a minimum gap of 0.5 to 5 mm formed from a rotating piece and a fixed piece, or formed from at least two kinds of rotating pieces
It has an outer shell formed by passing through an impact part having a shortest gap of 0.5 to 5 mm and fixing the outer shell forming resin particles (C) on the surface of the particles (A2) by a mechanical impact in the impact part. The present invention relates to a microcapsule toner.

Furthermore, the present invention provides particles (A1) having at least a binder resin and particles (B) having a particle size ratio of 0.2 or less with respect to the particles (A1) (provided that the particles (B) are colored particles and control particles. Electrolytic particles or abrasive particles) are formed from an impact part having a minimum gap of 0.5 to 5 mm formed from a rotating piece and a fixed piece or at least two kinds of rotating pieces under the condition of an ambient temperature of 10 to 90 ° C. The particles (A1) are passed through an impact part having a shortest gap of 0.5 to 5 mm and mechanically impacted at the impact part.
Particles (B) are fixed on the surface to form particles (A2), and outer shell forming resin particles (C) having a particle size ratio of 0.2 or less with respect to particles (A2) are used at an ambient temperature of 10 to 90 ° C. Below, an impact part having a shortest gap of 0.5 to 5 mm formed from a rotating piece and a fixed piece, or formed from at least two kinds of rotating pieces
The outer shell is formed by passing through an impact part having a shortest gap of 0.5 to 5 mm and fixing the outer shell-forming resin particles (C) on the surface of the particles (A2) by a mechanical impact at the impact part. And a method for producing a microcapsule toner.

[Detailed Description of the Invention] The microcapsule toner produced by the manufacturing method of the present invention has, for example, a cross-sectional structure schematically shown in FIG.

In the production method of the present invention, the particles (B) 62 are immobilized on the surface of the particles (A1) 61 by mechanical impact, and
2) is prepared. Further, resin particles for forming an outer shell (C)
Are applied to the particles (A2), and the particles (C) are immobilized on the surface of the particles (A2) by mechanical impact to form the outer shell 63.

When the particles (B) or (C) are uniformly immobilized on the particles (A1) or (A2), the particles (A1) or (A2) are preferably spherical particles having few protrusions.

The projections are not preferable because they are selectively subjected to a mechanical shock and are subjected to non-uniform thermal deformation and may be crushed. The particles (B) or (C) adhering to the recesses are less likely to be mechanically shocked at last, are less likely to be immobilized, and may exist in a free state, which is not preferable.

On the contrary, spherical particles are preferable because they can uniformly receive an impact force.

The particles (B) include electrostatic particles, colored particles and / or abrasive particles.

The case where the particles (B) are antistatic particles will be described below.

When a toner having antistatic fine particles on the surface is obtained by kneading and pulverizing, in order to obtain the necessary antistatic effect (suppress excessive toner charge-up) by internally adding the antistatic fine particles, Large additions are required.

These antistatic fine particles are present near the surface of the toner and particularly exert their effect. In the case of a toner obtained by kneading and pulverizing, there is a difference in dispersibility depending on the affinity between the binder resin and the antistatic fine particles used and the kneading method. For example, it is possible to lower the kneading temperature to improve the dispersibility of the antistatic fine particles, but there is a concern that the binder resin may be cut. Furthermore, the way of breaking the coarse particles of the kneaded product against impact when crushing further is random, and it is difficult to control the amount of the toner surface.

In the case of the toner obtained by the suspension polymerization method, it is difficult to obtain a good insulating toner when the colorant (especially magnetic substance or carbon) is exposed on the surface of the toner particle, and therefore the colorant is generally a hydrophobic one. The strong one is used. As a result, the surface of the toner particles becomes more insulating.

On the other hand, JP-A-58-66857 proposes to use a hydrophobically treated magnetic substance and an untreated magnetic substance in combination, but it is technically not easy to control the amount of the surface portion in the same manner.

In the case of a microcapsule toner whose surface is coated with a resinous substance, the surface of the toner particle is generally insulative. On the other hand, JP-A-60-3177 proposes a capsule toner in which a magnetic material is substantially exposed.
This is a coating method using a resin solution in which a magnetic material is dispersed, and it is difficult to control the surface uniformly because of the uneven distribution of the magnetic material.

The present invention is to immobilize particles (B) having an antistatic property on the surfaces of particles (A) by a mechanical impact, and further to coat the particles with an outer shell. The antistatic particles are not liberated in the subsequent steps (for example, stirring during external addition of silica, stirring during development, and rubbing),
Works together with microcapsule toner.

In the insulating toner, it is important to adjust the triboelectric charge amount to be constant. In order to obtain a good image even under different environments, an important characteristic for obtaining a good image that is the same as the initial stage in continuous image formation is how to control the triboelectric charge amount of the toner. Generally, when the rise of the triboelectric charge of the toner is improved, the absolute amount tends to increase, and it is necessary to create a large electric field to transfer the toner to the latent image surface due to the excessive charge amount, especially in a low humidity environment. Cause a load on the system, and there is a risk of discharge due to dielectric breakdown.

On the other hand, if the charging characteristics of the toner are suppressed, it takes time to have a sufficient amount of electric charge, especially in a high humidity environment, and it is possible to eliminate the toner that adheres to other than the latent image portion by a force other than electric force. However, there arises a problem that the image is stained.

The present invention solves these problems by immobilizing antistatic particles (B) on the surface of particles (A1) to form particles (A2), and thereafter particles (C) made of an outer shell forming resin for particles (A2). By immobilizing, the antistatic fine particles are evenly distributed on the particles (A1),
And a partially present microcapsule toner. The triboelectric charge amount of the microcapsule toner according to the present invention is controlled in this manner. In the microcapsule toner according to the present invention, the antistatic fine particles are present in a state of being fixed to the mother particles (A1), and the outer shell forming resin particles (C) are preferably 51 to 100% (preferably 80 to 100).
%, And more preferably 95 to 100%), so that excessive electrification is prevented and sufficient friction of the microcapsule toner particles is not hindered and the antistatic fine particles are Since it is not released, damage to the drum and cleaner is suppressed.

When particles (B) having an antistatic property are interfacially present in a large amount on the particles (A1), the resistance becomes too low and the charge is too low. Particles (B) are particles (A1) 10
It is preferable to use 0.1 to 10 parts by weight based on 0 parts by weight.

The microcapsule toner according to the present invention is to immobilize particles (B) having an antistatic property in a powder state by mechanical impact, and the amount of antistatic particles on the surface portion of the microcapsule toner is particles ( It is directly controlled by the addition amount of B). As a result, good developing characteristics can be obtained.

The microcapsule toner according to the present invention has few free antistatic particles and can obtain good developing characteristics without causing carrier contamination or sleeve contamination.

As the antistatic particles (B), it is preferable to use particles composed of simple antistatic particles. It is possible to use particles dispersed in a resin such as styrene, but attention must be paid to the dispersibility of the antistatic fine particles and the manner of exposure.

The average particle size of the particles (B) is preferably 0.2 or less with respect to the average particle size of the particles (A1). When the particle size ratio is 0.2 or more, it is difficult to uniformly fix the particles (B) on the surface of the particles (A1). The average particle size of the particles (C) made of the resin for forming the outer shell is less than 0.2 with respect to the average particle size of the particles (A2) in which the particles (B) are fixed to the particles (A1). Preferably there is. When the particle size ratio exceeds 0.2, it is difficult to uniformly fix the particles (C) on the surface of the particles (A2).

In the present invention, the coverage of particles (B) or particles (C) (the ratio of particles (A1) surrounded by particles (B) or the ratio of particles (A2) surrounded by particles (C)) is It is represented by the formula shown below.

[Wherein W ₁ represents the weight of the particles (A1) or (A2), W ₂
Represents the weight of particles (B) or (C), and R ₁ represents particles (A
1) or (A2) is an average particle size, R ₂ is an average particle size of particles (B) or (C), M ₁ is a true density of particles (A1) or (A2), M ₂ Indicates the true density of particles (B) or (C). ] Supply with the coverage calculated by this formula exceeding 100% shall be 100%.

The particles (A2) are preferably covered with the particles (C) at a coverage of 51% or more.

The particles (C) may cover the entire surface of the particles (A2). Even in such a case, since the releasable particles are present near the surface, the releasability is sufficiently exhibited.

The particle size distribution is measured by the following measuring method. A Coulter Counter TA-II type (manufactured by Coulter) or an Elzone Particle Counter 80XY-2 (manufactured by US Particle Data Co., Ltd.) is used as a measuring device, and a number average distribution and a volume average distribution are output. A 1 to 4% NaCl aqueous solution is used as the electrolytic solution.

As the measuring method, 0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) as a dispersant is added to 100 to 150 ml of the electrolytic aqueous solution, and 0.5 to 50 mg of a measurement sample is further added.
Add.

The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment for about 1 to 3 minutes with an ultrasonic disperser, and the dispersion was treated with the Coulter Counter TA-II type or the Elzone Particle Counter 80XY-2.
The volume average distribution and the number average distribution are obtained by measuring the particle size distribution of particles of 0.2 to 40 μ using an aperture of ˜120 μ.

The particles (B) having an antistatic property have an electric resistivity of 10 ¹³ to 10 ^-2.
Examples of alloy powders, metal oxides, semiconductors, ceramics, organic semiconductors, and carbon powders having Ω · cm, preferably 10 ⁴ to 10 ⁻² Ω · cm are exemplified. These may be used alone or in combination of two or more. Specific examples are shown below.

As the antistatic particles (B), powders of ferromagnetic metals such as iron, cobalt and nickel, alloys thereof, or magnetic powders such as magnetite, hematite and ferrite; SnO ₂ , ZnO, F
_{e 2 O, Al 2 O 3} , CaO, BaO, MgO, TiO 2, TiO, SnO 2 -TiO 2, SnO 2
-BaSO ₄ , SiO ₂ , SrTiO ₃ , and carbon black are available. ZnO
₂ , SiO ₂ , TiO ₂ , Al ₂ O ₃ , and SrTiO ₃ light or colorless can also be used for color.

The resistivity of the antistatic powder is measured by the device shown in FIG. In the figure, 71 is a pedestal, 72 is a pressing means, which is connected to a hand press and has a pressure gauge 73 attached thereto. 74 is the diameter
3. Place sample 75 in a 100 cm hard glass cell. 76
It is a brass press ram with a diameter of 4.266 cm and an area of 14.2857.
cm ² . 77 is a push rod made of stainless steel, radius 0.397 cm, area 0.
At 496 cm ² , pressure from press ram 76 is applied to sample 75.
78 is a brass base. 79 and 80 are bakelite insulating plates. 81 is an ohmmeter connected to 76 and 78. 82 is a dial gauge.

The apparatus of Figure 9, the application of pressure of the hydraulic 20 kg / cm ² to hand press the sample takes a pressure of 576kg / cm ^2. The resistance is read from the ohmmeter 81, multiplied by the cross-sectional area of the sample, and divided by the height of the sample read from the dial gauge 82 to obtain the specific resistance value.

Next, the case where the particles (B) are colored particles will be described.

The microcapsule toner of the present invention is obtained by mixing a colorant or a resin particle containing a colorant and a colorless resin particle in a powder form to obtain a particle in which a colored layer is immobilized on the colorless resin particle. The microcapsule toner in which the colored particles are covered with the shell is obtained by mixing the particles with the resin particles for forming the outer shell in the same manner.

In the case of conventional toners produced by melt-kneading, pulverizing and classifying, it is technically not always easy to uniformly disperse such a colorant in the binder resin. In particular, when a binder resin cross-linked for the purpose of improving the fixing property is used, it is more difficult to disperse, and it is possible to obtain a color toner having a wide reproducibility such as a good developability as a color image and an appropriate gloss. It's not easy.

In the case of the pulverization method, it is not preferable that the colorant appears or is released on the surface of the pulverized particles due to the pulverization of the kneaded product, in view of hygroscopicity and carrier contamination.

Examples of the colorant used as the colored particles (B) include the following pigments or dyes.

Examples of the dye include CI direct red 1, CI direct red 4, CI acid red 1, CI basic red 1, CI modant red 30, CI direct blue 1, CI direct blue 2, CI acid blue 9, and CI acid blue 15. , CI Basic Blue 3, CI Basic Blue 5, CI Modern Blue 7
There is.

As pigments, Naphthol Yellow S, Hansa Yellow G, Permanent Yellow NCG, Permanent Orange G
TR, Pyrazolone Orange, Benzidine Orange G, Permanent Red 4R, Watching Red Calcium Salt,
Brilliant Carmine 3B, Fast Violet Red (B), Methyl Violet Lake, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue
There is BC.

Disazo yellow, insoluble azo and copper phthalocyanine are suitable as pigments, and basic dyes and oil-soluble dyes are suitable as dyes.

CI Pigment Yellow 17, CI Pigment Yellow 15, CI Pigment Yellow 13, CI Pigment Yellow 14, CI Pigment Yellow 12, CI Pigment Red 5, CI Pigment Red 3, CI Pigment Red 2, CI Pigment Red 6, CI Pigment Red are particularly preferred. Red 7, CI Pigment Blue 15, CI Pigment Blue 16 or having the structural formula (1) shown below,
It is a copper phthalocyanine pigment which is a Ba salt in which a carboxybenzamidomethyl group is substituted in the phthalocyanine skeleton by 2-3.

Examples of the dye include CI solvent red 49, CI solvent red 52, CI solvent red 109, CI basic red 12, CI basic red 3b, and carbon black.

Further, when the colored particles (B) are colored resin particles (B), in the present invention, the colored particles (B) are fixed to the particles (A1), and further on the outer resin particles (C). Since it is coated, the resin used for the colored particles (B) can be selected considering only the dispersion of the colorant without considering the charging characteristics. When the colored particles (B) are produced by the suspension polymerization method, it is possible to select a monomer system that does not cause polymerization inhibition or dispersion failure without considering the chargeability after the resin particles are formed. The range of choices for the monomer system expands.

In the particles (B), the ratio of the colorant to the resin is 1 to 99
It should be 99: 1, preferably 5:95 to 95: 5.

As described above, the coverage of the colored particles (B) can take any value depending on the required coloring power because of the capsule structure according to the present invention. Considering the coloring power of general colorants, it is necessary to use 1% by weight or more of the colorant in the microcapsule toner particles.
Is preferred.

Next, the case where the particles (B) are abrasive particles will be described.

The microcapsule toner according to the present invention is such that abrasive particles are firmly and partially fixed on the surface of the particles (A1) in a partially submerged state, and the developability, transferability, fixability, and offset resistance of the microcapsule toner are obtained. By controlling the polishing power of the microcapsule toner itself without adversely affecting the property, the phenomenon of image deletion or fusion is prevented, the life of the photoconductor is extended, and the design of the microcapsule toner and the copying machine are facilitated. It is a thing.

In the present invention, the abrasive particles (B) are immobilized in a powder form by mechanical impact to the particles (A1). Therefore, the microcapsule toner of the present invention is not released by the subsequent steps. Works together with microcapsule toner.

Furthermore, the amount of abrasive particles on the surface of the particles (A1) is controlled by the amount added, and since they are evenly present, the excellent abrasiveness or lubricity of the added fine powder can be used as it is. The abrasiveness of the microcapsule toner can be controlled over a wide range by changing the amount.

Since the abrasive particles (B) are fixed on the surface of the particles (A1), the effect can be obtained with a small amount, and the microcapsule toner and the abrasive particles (B) are not separated at the time of development. The above effect can be achieved without adversely affecting the fluidity.

As the particles (B) having abrasiveness, it is preferable to use particles composed of abrasive fine particles alone. It is possible to use particles dispersed in a resin such as polystyrene, but attention must be paid to the dispersibility and exposure method of the abrasive fine particles.

As the abrasive particles (B), one or more inorganic metal oxides, nitrides, carbides, sulfuric acids or metal carbonates having a Mohs hardness of 3 or more are used. A specific example is shown below.

Metal oxides such as SiO ₂ , SrTiO ₃ , CeO ₂ , CrO, Al ₂ O ₃ , MgO;
Nitride such as Si ₃ N ₄ ; Carbide such as SiC, CaSO ₄ , BaSO ₄ , C
Examples thereof include sulfuric acid or metal carbonate such as aCO ₃ .

Preferably Mohs hardness of 5 or more SiO _2, SrTiO _3, CeO ₂ (e.g. Mireku, Mireku T, the powder having such CeO ₂ and rare earth elements of _{ROX M-1) Si 3 N} 4, SiC good.

These abrasive particles (B) may be surface-treated with a coupling agent such as a silane coupling agent, a titanium coupling agent, a zircoaluminate coupling agent, silicone oil or other organic compound.

The coverage of the abrasive particles (B) on the particles (A1) is 10 to 10
0% is preferable.

Abrasive particles (B) are 0.1 parts by weight per 100 parts by weight of particles (A1).
It is preferable to use 30 parts by weight.

The microcapsule toner having the abrasive particles (B) immobilized thereon is used to remove fatty acid metal salts or PVdF (polyvinylidene fluoride) from the viewpoint of easily cleaning low-resistance substances such as toner or paper powder from the photoreceptor. External addition of such a lubricious fine powder to the microcapsule toner produces a preferable effect.

Lubricating fine powders used include Teflon, polyvinylidene fluoride, fluorinated polymer particles such as fluorocarbon, zinc stearate particles, calcium stearate, magnesium stearate, zinc oleate, zinc palmitate, magnesium palmitate. A fatty acid metal salt such as is preferably used.

These lubricating fine powders preferably have an average particle size of 6 μm or less, more preferably 5 μm or less. The amount of external addition is 0.5% by weight or less based on the weight of the toner, preferably 0.01 to 0.3
Weight percent is used.

The antistatic component, coloring component, and polishing component of the particles (B) may be in the form of particles produced by mixing with a resin and granulating. Further, it may be in the form of particles produced by dispersing the active ingredient of the particles (B) in a monomer composition and suspension-polymerizing the dispersion.

As the resin used for the particles (B), a binder resin for toner can be used. Specifically, the particles (A
The binder resin from 1) can be used.

Next, the manufacturing method of the present invention will be specifically described below.

According to the method of the present invention, the particles (B) are dispersed and the particles (A) are uniformly dispersed.
1) Pretreatment to attach to particles; Particles attached (B)
Is immobilized on the surface of the particle (A1) by impact force to obtain the particle (A2); pretreatment for dispersing the particle (C) and uniformly adhering it to the particle (A2); ) Is immobilized on the surface of the particles (A2) by an impact force.

The pretreatment is to disperse the particles (B) or (C) and rub them with the particles (A1) or (A2) respectively to adhere them by electrostatic force (and van der Waals force). Generally, a high speed stirring blade A blender with is used. It is not limited to this as long as it has a mixing function and a dispersing function. FIG. 1 shows an example of a mixer (Henschel mixer) equipped with a high-speed stirring blade. As the pretreatment, it is necessary that the particles are well dispersed and that the particles are not pulverized substantially.

The mixer shown in FIG. 1 includes a jacket 1; a stirring blade 2; a control plate 3;
Cylinders 4 and 4b; direction control unit 5; discharge port 6 are provided.

It depends on the physical properties of the material of the microcapsule toner, but the pretreatment temperature is 0 to 50 ° C, and the circumference of the blade tip is 5
The treatment time is preferably 50 m / sec to 1 minute to 60 minutes (more preferably 1 to 20 minutes). When such a treatment is performed, the temperature rises due to stirring, so it is preferable to cool the jacket or cool the tank by introducing cooling air.

The pretreatment device does not have to be a mixer with a high-speed stirring blade, but may have a dispersing function and a mixing function and can obtain a sufficiently long residence time. It is also good to use after reducing the impact force.

In the pretreatment, when the particles (B) (or particles (C)) are uniformly attached to the particles (A1) (or particles (A2)), the fluidity of the particles (B) (or particles (C)),
Dispersibility is important. When the particles (B) (or the particles (C)) exhibit strong agglomeration, individual particles cannot be formed in the pretreatment step and uniform adhesion tends to be difficult. Even if the fluidity is extremely poor, it is difficult to form individual particles, and likewise, uniform adhesion is difficult. Liquidity,
Regarding particles (B) (or particles (C)) having poor dispersibility, particles (B) (or particles (C)) having improved fluidity and dispersibility by previously mixing and mixing silica fine powder with the particles (B) (or particles (C)) Alternatively, by using particles (C)), particles (B)
(Or particles (C) to particles (A1) (or particles (A
It is particularly preferable to use the method of uniformly adhering to 2)). The fine silica powder used in this case is preferably positively charged treated silica for positively charged toner and negatively charged treated silica for negatively charged toner. The addition amount is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on the weight of the particles (B) (or (C)). As the treated silica, a hydrophobic silica fine powder treated with one or more of a positively or negatively charged silane coupling agent, a hydrophobic treatment agent, and a silicone oil is preferable. The silica fine powder preferably has a specific surface area of 40 to 400 m ² / g measured by a nitrogen gas adsorption method.
Hydrophobicity measured by methanol titration test is 30
Particularly preferred is -80% treated silica fines.

Defined herein to evaluate the degree of hydrophobicity of the treated silica fines. The "methanol titration test" is performed as follows. 0.2 g of the fine silica powder to be tested is added to 50 ml of water in an Erlenmeyer flask having a volume of 250 ml. Methanol is titrated from the burette until the total amount of silica is wet.
At this time, the solution in the flask is constantly stirred with a magnetic stirrer. The end point is observed by suspending the total amount of silica fines in the liquid and the degree of hydrophobization is expressed as the percentage of methanol in the liquid mixture of methanol and water when the end point is reached.

In immobilization, crushed particles of particles (A1) or (A2) or particles (B) or (C) are released, and re-release of particles (B) or (C) once attached is not preferable. It is preferably fixed to.

It is important to control the impact force in the range where the particles (A1) or (A2) are not crushed and the temperature in the range where fusion coagulation does not occur. As an example of a fixing device for carrying out the present method, a pin mill (Fig. 4-1) having a recycling function and a large number of rotating pins, and a rotating blade or hammer (rotating piece) and a liner (fixing piece) It is effective to use a crusher (Figs. 2-1 and 3) that gives a shock between the two and has a recycling mechanism.

The apparatus shown in FIG. 2-1 includes a jacket 1a, a rotary shaft 12, a rotor 14, a dispersion blade 14, a rotary piece (blade) 15, a partition disk 16, a casing 17, a liner 18, an inlet chamber 20, an outlet chamber 21, Return way
It is equipped with 22, product outlet 23, raw material inlet 24, and blower 25.

The device shown in FIG. 3-1 includes a jacket 16, a rotary shaft 12b, a return path 22b, a product outlet 23b, a raw material inlet 24b, and a blower blade 3.
0, rotor (with blade) 31, outlet 32, inlet 36 are provided.

The device shown in FIG. 4-1 includes a jacket 1c, a rotary shaft 12c, a rotor 13c, a casing 17c, a return path 22c, a product outlet 23c,
Raw material inlet 24c, outlet 32c, inlet 36c, fixed pin 39, rotating pin 4
It has 0.

The peripheral speed of the tip of the rotating piece in the device is preferably 30 to 130 m / sec. The ambient temperature varies depending on the physical properties of the particles (A1) or (A2) and the particles (B) or (C), but a temperature of 10 to 90 ° C, preferably 30 to 70 ° C is good, and the residence time of the impact part is 0.
02 sec to 12 sec is preferable. In the case of a pin mill, it is necessary to increase the concentration of particles. In a device of the type shown in FIGS. 2-1 or 3-1, particles to be processed by centrifugal force are collected in the vicinity of the liner, so that the latitude of particle concentration is wide. The shortest clearance between pin mills or blades or hammers and liners is about 0.5-5 mm, preferably 1 m
Adjust to m ~ 3 mm.

A more detailed description will be given with reference to FIG. The particles (A1) and (B) or the particles (A2) and (C) pretreated by the above-described method are charged from the raw material charging port 24, pass through the inlet chamber 20, and rotate along the rotating dispersion blade 14. The circuit is circulated again through the impact section 19 between the blade 15 and the liner 18, the outlet chamber 21, the return path 22 and the blower 25. After the immobilization process is completed, the product is taken out from the product take-out port 23.

Here, the powder composed of the particles (A1) and the particles (B) or the particles (A2) and (C) is the blade 15 at the impact portion 19.
An impact is applied between the liner 18 and the liner 18, and the fixing process is performed.

Here, if necessary, it is preferable to flow cooling water through the jacket 1 to adjust the ambient temperature. In FIG. 2-2, the gap a between the blade 15 and the liner 18 is the shortest gap, and the space corresponding to the width b of the blade 15 is the impact portion.

FIG. 3-3 shows the positional relationship between the liner 18b of the fixing device and the rotating rotor 31. The shortest gap between the liner 18b and the rotor 31 is the tip of the protruding portion to the inner circumference of the liner 18b. It means the difference between the radii of the two circles of the circumference 51 and the locus 52 of the protrusion of the rotor 31 obtained by connecting the two. The same applies when a blade or a hammer is used instead of the rotor 31.

FIG. 4-2 is a schematic view of the pin in the pin mill type fixing device as seen from the front of the device, and the gap 41 between the fixed pin 39 and the rotating pin 40 is the shortest gap. 42 shows the maximum gap, and 43 shows the trajectory of the rotating pin 40.

The particles (A1) may be colorless resin particles or colored resin particles.

When the particles (A1) are colored resin particles, the particles (A1) are obtained as follows, for example. As the particles (A1) obtained by the pulverization method, at least a binder resin and a coloring agent (if necessary, a release agent)
The mixture consisting of and is melt-kneaded, cooled and then ground by a grinder, and if necessary, classified to have a uniform particle size distribution. The volume average particle diameter of the particles (A1) preferable as the microcapsule toner for developing an electrostatic image is 2 to 20 μm.

As the binder resin used, a homopolymer of polystyrene and its substitution product: styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, Styrene-isoprene copolymer, styrene-
A styrene-based copolymer such as acrylonitrile-indene copolymer: acrylic resin, methacrylic resin, silicone resin, polyester resin, furan resin, epoxy resin,
Is exemplified. In the case of the heat roller fixing microcapsule toner, a preferable binder resin is a crosslinked styrenic copolymer or a crosslinked polyester. Acrylic acid, as the comonomer of the styrene-based copolymer,
Methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate,
A dicarboxylic acid having a double bond such as butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, and acrylamide, and a substituted product thereof are used. A compound having two or more polymerizable double bonds is mainly used as the cross-linking agent. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate and 1,3-butanediol dimethacrylate; divinylaniline and divinylaniline Vinyl ether,
Divinyl compounds such as divinyl sulfide and divinyl sulfone and compounds having three or more vinyl groups are used alone or as a mixture.

The amount of the crosslinking agent added is 0.1 with respect to 100 parts by weight of the polymerizable monomer.
It is preferable to use ~ 5 parts by weight.

Next, the magnetic powder and colorant used for the particles (A1) will be described. To produce magnetic toner, magnetic particles are added. In this case, the magnetic particles also serve as a coloring agent. As the magnetic particles that can be used in the present invention, substances that are placed in a magnetic field and magnetized are used. Examples thereof include powders of ferromagnetic metals such as iron, cobalt and nickel, powders of alloys thereof or powders of compounds such as magnetite, hematite and ferrite. Particle size is 0.1-1μ
m, preferably 0.1-0.5 μm magnetic particles are used. The content of the magnetic particles is 10 to 65% by weight, preferably 20 to 60% by weight, based on the weight of the microcapsule toner. These magnetic fine particles may be treated with a treating agent such as a silane coupling agent or a titanium coupling agent, or an appropriate reactive resin. In this case, depending on the surface area of the magnetic fine particles and the density of hydroxyl groups present on the surface, 5% by weight
The following (preferably 0.1 to 3% by weight) treatment amount provides sufficiently preferable dispersibility.

As the colorant, the colorant described in the above-mentioned particles (B) can be used. Colorant is 0.5-30 based on the binder resin
It is preferably contained by weight%.

It is particularly preferable to obtain the particles (A1) by the suspension polymerization method described below because the particle size distribution is sharp and spherical particles can be obtained.

The polymerizable monomer applicable to form colored particles as particles (A1) by a suspension polymerization method is CH ₂ =
It is a monomer having a C <group. Styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene,
Styrene and its derivatives such as p-methoxystyrene and p-ethylstyrene; acrylic acid, methacrylic acid, maleic acid, maleic acid half ester; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, methacrylic acid. Α such as isobutyl, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate.
-Methylene aliphatic monocarboxylic acid esters; methyl acrylate, ethyl acrylate, n-butyl acrylate,
Isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-acrylate
Ethylhexyl, stearyl acrylate, acrylic acid 2
-Acrylic esters such as chloroethyl, phenyl acrylate: acrylonitrile, methacrylonitrile,
Examples are acrylic acid or methacrylic acid derivatives such as acrylamide. These may be used alone or in combination of two or more. You may use a crosslinking agent as needed.
Examples of the cross-linking agent include divinylbenzene, divinylnaphthalene, diethylene glycol dimethacrylate, and ethylene glycol dimethacrylate. The amount of the crosslinking agent added is 0.1 to 5 parts by weight based on 100 parts by weight of the polymerizable monomer. A small amount of a polymer of these polymerizable monomers may be added to the monomer composition. Among the above monomers,
Styrene, styrene having a substituent such as an alkyl group,
Alternatively, the polymerized colored particles (A1) produced from a mixed monomer of styrene and another monomer are preferable in view of developability and durability.

Preferable particles (A1) can be obtained by adding a polar polymer having a polar group, a polar copolymer or a cyclized rubber as an additive during the polymerization of the monomer to polymerize the polymerizable monomer. The polar polymer, polar copolymer or cyclized rubber may be added in an amount of 0.5 to 50 parts by weight, preferably 1 to 40 parts by weight, based on 100 parts by weight of the polymerizable monomer. If it is less than 0.5% by weight, it is difficult to obtain a sufficient pseudocapsule structure, and if it exceeds 50 parts by weight, the amount of the polymerizable monomer becomes insufficient and the properties as particles (A1) tend to be deteriorated. . A polar polymer, a polar copolymer, or a polymerizable monomer composition containing a cyclized rubber is suspended in an aqueous phase of an aqueous medium in which the polar polymer and a dispersion stabilizer having an opposite charge property are dispersed. Polymerization is preferred. The cationic or anionic polymer, cationic or anionic copolymer or anionic cyclized rubber contained in the polymerizable monomer composition is a reversely charged anionic or anionic cyclized rubber dispersed in an aqueous medium. The cationic dispersant and the toner particle surface electrostatically attract each other,
The dispersion stabilizer covers the particle surface to prevent the particles from coalescing with each other and stabilizes the particles, and the added polar polymer,
Since the polar copolymer or the cyclized rubber gathers on the surface layer of the particles (A1), it becomes a kind of shell-like morphology, and the obtained particles become pseudo capsules. The relatively high molecular weight polar polymer, polar copolymer or cyclized rubber gathered in the surface layer of the particle encloses a large amount of the low softening point compound inside the toner particle, resulting in blocking property and development in the microcapsule toner. Imparts excellent properties such as wear resistance and wear resistance.
The polar polymers (including polar copolymers and cyclized rubbers) and reverse charge dispersion stabilizers that can be used in the present invention are exemplified below. The polar polymer has a weight average molecular weight of 5,000 to 500, measured by gel permeation chromatography (GPC).
Those of 000 (preferably 50,000 to 200,000) are preferably used because they dissolve well in the polymerizable monomer and have durability.

(I) As the cationic polymer, a polymer of a nitrogen-containing monomer such as dimethylaminoethyl methacrylate or diethylaminoethyl acrylate; a copolymer of styrene and the nitrogen-containing monomer; or styrene and an unsaturated carboxylic acid. There is a copolymer of an ester and the nitrogen-containing monomer.

(Ii) As the anionic polymer, a polymer of a nitrile monomer such as acrylonitrile; a polymer of a halogen-containing monomer such as vinyl chloride; a polymer of an unsaturated carboxylic acid such as acrylic acid; There are polymers of saturated dibasic acids; polymers of anhydrides of unsaturated dibasic acids or copolymers of styrene and the above monomers.

As the dispersion stabilizer, an inorganic fine powder which has the ability to disperse and stabilize the monomer composition particles in an aqueous medium and is sparingly soluble in water is preferable. The amount of the dispersion stabilizer added to the aqueous medium is preferably 0.1 to 50% by weight (preferably 1 to 20% by weight) based on water.

(Iii) Aerosil # 2 as anionic dispersion stabilizer
There are colloidal silicas such as 00, # 300 (made by Nippon Aerosil Co., Ltd.).

(Iv) Cationic dispersion stabilizers include aluminum oxide, magnesium hydroxide, and hydrophilic positively charged silica fine powder such as aminoalkyl-modified colloidal silica treated with a coupling agent.

Instead of the above polar polymer or copolymer, a cyclized rubber having anionic property may be used.

To produce polymerized colored particles having magnetism as particles (A1), magnetic particles are added to the monomer composition. in this case,
The magnetic particles also serve as a coloring agent. The above-mentioned magnetic particles can be used as the magnetic particles usable in the present invention.

As the colorant, the above-mentioned dyes, pigments, carbon black, and pigments such as grafted carbon black obtained by coating the surface of carbon black with a resin can be used.
Colorants are based on the polymer and low softening point compound.
It is contained in an amount of 5 to 30% by weight.

The suspension polymerization method is a monomer composition in which a colorant or an additive is uniformly dissolved and dispersed, if necessary, at 0.1 to 50% by weight.
An aqueous medium containing a dispersion stabilizer (eg, a sparingly soluble inorganic dispersant) (eg, 5 ° C. or higher than the polymerization temperature, preferably
It is heated to a temperature of 10 ° C to 30 ° C or more) by a usual stirrer, a homomixer, or a monogenizer.

Preferably, the stirring speed, time and aqueous medium are such that the particles of the melted or softened monomer composition have the desired toner particle size, generally less than 30 μm (eg volume average particle size 2-20 μm). Adjust the temperature of. afterwards,
Due to the action of the dispersion stabilizer, almost that state is maintained,
The liquid temperature of the aqueous medium is lowered to the polymerization temperature while stirring is performed to such an extent that settling of particles is prevented. The polymerization temperature is set to 50 ° C. or higher, preferably 55 to 80 ° C., particularly preferably 60 to 75 ° C., and a substantially water-insoluble polymerization initiator is added with stirring to carry out polymerization. The polymerization initiator may be contained in the monomer composition in advance. After completion of the reaction, the produced particles (A1) are collected by a suitable method such as washing, removal of dispersion stabilizer, filtration, decantation, and centrifugation, and dried to obtain polymerized colorless particles (A1).
Alternatively, polymerized colored particles (A1) are obtained. In the suspension polymerization method, usually 200 to 3000 parts by weight of water is used as an aqueous dispersion medium with respect to 100 parts by weight of the polymerizable monomer and the low softening point compound.

The particles (A1) are obtained by heating and mixing the binder resin and the colorant,
It may be produced by a method of forming fine particles in a molten state. In this case, various liquid atomization methods can be applied. For example, one fluid nozzle by pressure, two fluid nozzle by high pressure air flow,
A disc atomizer using a rotating disc may be used.

The binder resin of the particles (A1) used in the present invention, or the particles (A1) themselves have a softening point of 90 to 150 measured by the following method when the microcapsule toner is used in a heat fixing method. C. is preferable, and 90 to 140.degree. C. is particularly preferable.

A flow tester CFT-500 type (manufactured by Shimadzu Corp.) is used, and a sample of 60mesh bath product is weighed in an amount of about 1.0 to 1.5 g, and this is pressed for 1 minute with a load of 100 kg / cm ² using a molding machine.

A flow tester measurement is performed on this pressurized sample under the following conditions, and the temperature corresponding to 1/2 of the stroke difference at the start of outflow and the end of outflow is taken as the softening point. Measurement conditions DATE TEMP 5.0 D / M (℃ 1 minute) SET TEMP 50.0 DEG (℃) MAX TEMP 200.0 DEG INTERVAL 2.5 DEG PREHEAT 300.0 SEC (sec) LOAD 50.0 KGF (kg) DIE (DIA) 0.5 MM (mm) DIE ( LENG) 1.0 MM PLUNGER 1.0CM ² (cm ² ) When the charge control agent is contained in the particles (A1), the following charge control substances can be used.

The charge controllable substance in the present invention means a substance satisfying the following triboelectric charging characteristics. Sufficiently knead 5 parts by weight of the charge control material with 100 parts by weight of the bulk polymer of polystyrene resin (weight average molecular weight of about 100,000 to 200,000) at a heat roll at 100 to 150 ° C. (for example, for about 30 minutes to After cooling for 1 hour), the mixture is pulverized, and classified to obtain polystyrene particles containing a charge control substance having a main particle size of 10 μm. About 5 g of the prepared polystyrene particles and 95 g of carrier iron powder (for example, EFV200 / 300 manufactured by Nippon Iron Powder Co., Ltd.) which is not coated with a resin having a main particle size of 200 to 300 mesh at 25 ° C. and 50 to 60% RH After leaving it in the environment overnight, mix it thoroughly in a polyethylene container with a volume of about 200 cc (about 5 to 10 minutes), and use an aluminum cell with a 400-mesh screen to perform tribo charge by the usual blow-off method. Measure the quantity. The tribo charge measured by this method is 2μ in absolute value.
It has a value of c / g or more, particularly 7 μc / g or more.

As the charge control substance used in the microcapsule toner of the present invention, a positive or negative charge control agent that is at least solid at a temperature of 20 to 90 ° C. is used.

(1) The following substances are used to control the toner to be positively charged.

Nigrosine, an azine dye containing an alkyl group having 2 to 16 carbon atoms (Japanese Patent Publication No. 42627/1987), a basic dye [eg C.I.
I.Basic Yellow 2 (CI41000), CIBasic Yellow
3, CIBasic Red 1 (CI45160), CIBasic Red 9
(CI42500), CIBasic Violet 1 (CI42535), C.
I.Basic Violet 3 (CI42555), CIBasic Violet 10
(CI45170), CIBasic Violet 14 (CI42510),
CIBasic Blue 1 (CI42025), CIBasic Blue 3
(CI51005), CIBasic Blue 5 (CI42140), CI
Basic Blue 7 (CI42595), CIBasic Blue 9 (CI5
2015), CIBasic Blue 24 (CI52030), CIBasic
Blue 25 (CI52025), CIBasic Blue 26 (CI4404
5), CIBasic Green 1 (CI42040), CIBasic Gre
en 4 (CI42000)], lake pigments of these basic dyes, (as laking agents, phosphotungstic acid, phosphomolybdic acid, phosphotungstic molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide, Russian compound), CISovent Black 3 (CI26150),
Hansa Yellow G (CI11680), CIMordlant Black
11, CI Pigment Black 1, benzolmethyl-hexadecyl ammonium chloride, decyl-trimethyl ammonium chloride, or dialkyltin compounds such as dibutyl or dioctyl, dialkyltin borate compounds, guanidine derivatives, vinyl polymers containing amino groups, containing amino groups A polyamine resin such as a condensation polymer.

(2) The following substances control the toner to be negatively charged. Japanese Patent Publication No. 41-20153, No. 43-27596, No. 44-63
Metal complex salts of monoazo dyes described in Nos. 97 and 45-26478. JP-B-55-42752, JP-B-58-41508, JP-B-58-7384, JP-B-59-7385, salicylic acid, dialkyl salicylic acid, naphthoic acid, dicarboxylic acid Zn, Al, Co, Metal complexes such as Cr and Fe, sulfonated copper phthalocyanine pigments.

Further, the charge control agent to be used in the present invention is required to have little environmental dependence, be thermally stable, be mechanically stable, and be chemically stable.

When the charge control substance is a resin, the resin is pulverized by a generally known method to obtain fine particles. If necessary, classification may be carried out to obtain preferable fine particles. Fine particles may be obtained by heating and spraying.

The charge control agent is used in an amount of 0.1 to 10 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the resin component of the particles (A1).

The particles (A1) according to the present invention may contain a releasing material in order to improve the offset resistance and / or the fixability of the microcapsule toner.

Examples of the material having releasability are shown below.
Softening point measured by ring and ball method (see JIS K 2531 etc.) is 40-13
A low molecular weight resin or wax having a temperature of 0 ° C, preferably 50 to 120 ° C. If the softening point is lower than 40 ° C, the blocking resistance and shape retention of the toner will be insufficient,
If it exceeds, the effect of lowering the fixing temperature or the fixing pressure is small. As the release agent, wax, low molecular weight polyolefin, modified wax having an aromatic group, hydrocarbon compound having an alicyclic group, natural wax, a long-chain hydrocarbon chain having 12 or more carbon atoms [CH ₃ CH _{2 11} or CH Long chain carboxylic acids having _{2 12} or more aliphatic carbon chains], their ester fatty acid metal salts, fatty acid acids, and fatty acid bisands. Different low softening point compounds may be mixed and used.

Specifically, Microwax (Nippon Petroleum), Microcrystalline Wax (Nippon Wax), PE-130 (Hoechst), Mitsui High Wax 110P (Mitsui Petrochemical), Mitsui High Wax 220P (Mitsui Petrochemical) Mitsui High Wax 660P (Mitsui Petrochemical), Mitsui High Wax 210P (Mitsui Petrochemical), Mitsui High Wax 320P (Mitsui Petrochemical), Mitsui High Wax 410P (Mitsui Petrochemical), Mitsui High Wax 420P (Mitsui Petrochemical), modified wax JC-1141 (Mitsui Petrochemical), modified wax JC
-2130 (Mitsui Petrochemical), modified wax JC-4020 (Mitsui Petrochemical), modified wax JC-1142 (Mitsui Petrochemical), modified wax JC-5020 (Mitsui Petrochemical): Beeswax, carnauba wax , Montan wax, and polytetrafluoroethylene.

Examples of fatty acid metal salts include zinc stearate, calcium stearate, magnesium stearate, zinc oleate, zinc palmitate, and magnesium palmitate.

These may be used alone or in combination of two or more.

The releasable substance is 0.1 to 100 parts by weight of the resin component of particles (A1)
It is recommended to use 10 parts by weight, preferably 0.5 to 5 parts by weight.

When the microcapsule toner according to the present invention is used as a pressure-fixing capsule toner, waxes such as polyethylene wax, polyethylene oxide, paraffin, fatty acid, fatty acid ester, fatty acid amide, fatty acid metal salt and higher alcohol; ethylene-acetic acid Vinyl resin and cyclized rubber can be used as the binder resin for the particles (A1).

A binder resin for toner can be used as the particles (C). For example, homopolymers of polystyrene and its substitutes;
Styrene such as styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer Acrylic resin, acrylic resin, methacrylic resin, silicone resin, polyester resin, epoxy resin can be used. A preferable binder is a crosslinked styrene copolymer or a crosslinked polyester resin. Styrene-based copolymer comonomers include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate. , Ethyl methacrylate, butyl methacrylate,
A monocarboxylic acid having a double bond such as octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide or a substituted product thereof; a dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate or dimethyl maleate, and The substitution product is mentioned. A compound having two or more polymerizable double bonds is mainly used as the cross-linking agent. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate and 1,3-butanediol dimethacrylate; divinylaniline; Examples are divinyl compounds such as divinyl ether, divinyl sulfide, divinyl sulfone, and compounds having 3 or more vinyl groups. The crosslinking agents may be used alone or as a mixture. The resin used for the particles (C) has a Tg of 50 ° C. or higher, preferably 55 ° C. or higher (particularly 55 to 65 ° C.) in terms of so-called blocking property and fixing property for long-term storage.

When particles (C) of a nitrogen-containing resin such as a styrene-dimethylaminoethyl methacrylate copolymer are used when the outer shell of the capsule is to have charge controllability by a resin, the finally formed micro-particles are formed. It is possible to stably and positively charge the capsule toner. Particle (C)
It is also possible to incorporate a general charge control agent into the.

Outer shell forming resin particles (C) for coating the core particle surface (A2)
The addition amount of is not uniquely determined by the surface shape of the particles (A2), the material of the particles (A2) and the density of the particles (C), and the particle diameter of the particles (A2). In the present invention, the addition amount of the particles (C) can be determined by calculating the weight of the particles (C) corresponding to the set film thickness according to the following formula in view of the characteristics of the microcapsule toner.

The addition amount of the particles (C) is preferably calculated by the following formula.

[Wherein δ: set film thickness (μm), W: charged amount of particles (C), ρ: density of particles (C), G: density of particles (A2), S: charged amount of particles (A2) , D: Volume average particle size of particles (A2) (μ
m).

The set film thickness δ in the present invention is 0.01 to 2.0 μm (further,
0.05 to 1.0 μm) is preferable. This set film thickness is 0.01 μm
If it is less than 100%, it is difficult to completely coat the shell material on the surface of the particles (A2), a defective film is likely to occur, and it is difficult to perform stable triboelectrification in the development under high humidity. is there. Further, in the case of a capsule type toner using a soft substance in the particles (A2), sleeve fusion or drum fusion is likely to occur.

On the other hand, when the set film thickness exceeds 2.0 μm, the resistance of the microcapsule toner becomes too high, which may cause the development in low humidity.
A non-uniform coating of microcapsule toner is likely to occur on the sleeve. Furthermore, when immobilized, particles (A2)
The number of particles (C) that exist independently without adhering to the surface increases, and an adverse effect such as fog is likely to occur.

The microcapsule toner obtained by the production method of the present invention can be applied to a known dry electrostatic image developing method. For example,
Cascade method, magnetic brush method, microtoning method,
Two-component developing method such as two-component AC bias developing method: conductivity-
Magnetic toner such as component developing method, insulating-component developing method, jumping developing method-component developing method; powder cloud method and fur brush method; toner is retained by electrostatic force on a toner carrier. It is applicable to a non-magnetic component developing method in which the toner is conveyed to the developing section and is used for development; an electric field curtain developing method in which toner is conveyed to the developing section by the electric field curtain method and is used for development.

When the microcapsule toner according to the present invention is used in a two-component developer, as a carrier, surface-oxidized or unoxidized iron, nickel, copper, zinc, cobalt, manganese,
Chromium, rare earth metals and their alloys or oxides and ferrites can be used. You may coat the surface of the said carrier with resin.

The substance adhered to the carrier surface is selected according to the material forming the microcapsule toner. For example, polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, metal complex of ditertiary butylsalicylic acid, styrene resin, acrylic resin, polyacid, polyvinyl butyral, nigrosine, amino acrylate resin , Basic dyes and lakes thereof, fine silica powder, fine alumina powder, and these may be used alone or in combination.

The treatment amount of the above compounds is generally the total amount with respect to the carrier.
0.1 to 30% by weight (preferably 0.5 to 20% by weight) is preferable.

The average particle size of the carrier is 20-100μ, preferably 25-70
It is preferable to have μ, more preferably 30 to 65 μ.

In a particularly preferred embodiment, Cu-Zn-Fe ternary ferrite is used, and the surface thereof is preferably a styrene resin or a mixture of a resin such as a fluorine resin and a styrene resin. For example, polyvinylidene fluoride and styrene-methyl methacrylate resin; polytetrafluoroethylene and styrene-methyl methacrylate resin, fluorine-based copolymer and styrene-based copolymer; 90:10 to 20:80, preferably
A mixture of 70:30 to 30:70, 0.01 to 5% by weight, preferably 0.1 to 1% by weight, with 250 mesh pass and 350 mesh on carrier particles of 70% by weight or more. Examples include coated ferrite carriers having a particle size. Examples of the fluorine-based copolymer include vinylidene fluoride-tetrafluoroethylene copolymer (10:90 to 90:10), and examples of the styrene-based copolymer include styrene and 2-ethylhexyl acrylate (20: 8).
0-80: 20), styrene-2-ethylhexyne acrylate-methyl methacrylate (20-60: 5-30: 10-50).

The above-mentioned coated ferrite carrier has a sharp particle size distribution, has a triboelectric charging property preferable for a microcapsule toner, and has an effect of improving electrophotographic characteristics.

When a two-component developer is prepared by mixing with the microcapsule toner according to the present invention, the mixing ratio is 5.0% by weight to 15% by weight, preferably 6% by weight to 13% by weight, as the concentration of the microcapsule toner in the developer. Good results are obtained with%. If the microcapsule toner concentration is less than 5.0%, the image density will be low, and if it exceeds 15%, fog and in-machine scattering will be increased, and the useful life of the developer will be shortened.

As the fluidity improver used by being mixed with the microcapsule toner according to the present invention, it is possible to use a fluidity improver which, when mixed with the microcapsule toner, can increase the fluidity of the microcapsule toner before and after the addition.

For example, fluororesin powder (vinylidene fluoride fine powder, polytetrafluoroethylene fine powder, etc.); fatty acid metal salt (zinc stearate, calcium stearate, lead stearate, etc.); metal oxide (zinc oxide powder, etc.); fine powder There are silica (that is, wet-processed silica, dry-processed silica, silica treated with a silane coupling agent, a titanium coupling agent, silicon oil, and the like).

A preferable flow improver is a fine powder produced by vapor phase oxidation of a silicon halogen compound, which is so-called dry process silica or fumed silica. For example, the thermal decomposition oxidation reaction of silicon tetrachloride gas in oxyhydrogen flame is utilized, and the basic reaction formula is as follows.

SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl In this manufacturing process, it is possible to obtain a composite fine powder of silica and other metal oxides by using a metal halogen compound such as aluminum chloride or titanium chloride together with a silicon halogen compound. is there. The average particle size of the particles is preferably in the range of 0.001 to 2 μ, and particularly preferably, fine silica powder in the range of 0.002 to 0.2 μ is used.

An external additive such as an abrasive such as cerium oxide may be used in combination.

Hereinafter, the present invention will be described in detail based on examples. The number of parts in this example represents parts by weight unless otherwise specified.

Example 1 Preparation of colorless particles (A): The above components were mixed by an attritor at a concentration of 60 ° C. for 1 hour to prepare a monomer composition. In a container having an Ajihomo mixer manufactured by Tokushu Kika, 1200 parts of ion-exchanged water containing 15 parts of 0.1N hydrochloric acid and kept at 60 ° C. is put, and silica having positively charged amino groups in water (colloidal silica ( Aerosil # 200) treated with 5% by weight of aminopropyltriethoxysilane) was added and dispersed.

After adding 10 parts of 2,2'-azobis- (2,4-dimethylvaleronitrile) and 1 part of 2,2'-azobisisobutyronitrile to the above monomer composition, an Ajihomo mixer was used. Put it in a container and have a homomixer rotating at 9,000 rpm.
Granulation was performed by high speed stirring for 30 minutes.

Furthermore, change the stirring from a homo mixer to a paddle mixer,
The polymerization was completed by stirring for 16 hours while maintaining the temperature at 60 ° C.
After cooling, add sodium hydroxide solution in excess to dissolve and remove silica, repeat washing with water twice and then at 40 ° C.
After leaving to stand in a ventilation dryer for 24 hours, colorless particles (A1) having a volume average particle diameter of 10.0 μm were obtained.

Preparation of colored particles (B): The above components were dispersed by heating with an attritor at 60 ° C. to obtain a monomer composition. It was prepared by adding 2 parts of 2,2'-azobis- (2,4-dimethylvaleronitrile) to the above monomer composition. The monomer composition prepared was added to a stainless steel container having a capacity of 2 liters containing 15 parts of the same amino group-containing silica used for the preparation of particles (A1), 600 parts of distilled water and 30 parts of 1/10 N hydrochloric acid. At 60 ° C., a TK homomixer (manufactured by Tokushu Kika Kogyo) was used to stir at 10,000 rpm for 60 minutes for preliminary dispersion to prepare a dispersion liquid. This dispersion was granulated at a discharge pressure of 400 kg / cm ² using a piston type high pressure homogenizer (manufactured by Gorin Co., Ltd., model 15M-8TA). The time required for granulation was 5 minutes. After granulation, the mixture was stirred with a paddle stirring blade for 12 hours at 60 ° C. to complete the polymerization.

Then, it was cooled, washed with a sodium hydroxide solution, dehydrated and dried to obtain particles (B). The obtained particles (B) had a volume average diameter of 1.0 μm.

Preparation of particles (C) The above components were dispersed by heating with an attritor at 60 ° C. to obtain a monomer composition. It was prepared by adding 2 parts of 2,2'-azobis-2,4-dimethylvaleronitrile to the above monomer composition. The monomer composition prepared was added to a stainless steel container having a volume of 2 l containing 7 parts of the same amino group-containing silica as used for the preparation of the particles (A1) and 30 parts of 1/10 N hydrochloric acid, and the mixture was kept at 60 ° C. A TK homomixer (manufactured by Tokushu Kiki Co., Ltd.) was used to stir at 10,000 rpm for 60 minutes for preliminary dispersion to prepare a dispersion liquid. This dispersion is a piston type high pressure homogenizer (manufactured by Gorin Co., model 15M-8
(TA) with a discharge pressure of 400 kg / cm ² . After granulation, the polymerization was completed at 60 ° C. for 12 hours while stirring with a paddle mixer. Then, it was cooled, washed with sodium hydroxide, dehydrated and dried to obtain particles (C). The obtained particles (C) had a volume average diameter of 1.0 μm.

30 parts of particles (B) per 100 parts of particles (A1) were mixed by stirring with Henschel mixer FM10B (manufactured by Mitsui Miike) shown in FIG. 1 at a blade tip peripheral speed of 30 m / sec at room temperature for 3 minutes,
Pretreatment was performed. Then, using the apparatus shown in FIG. 2-1, treatment was carried out while circulating the blade tip at a peripheral speed of 70 m / sec for 7 minutes to obtain yellow-colored particles (A2).
The shortest gap at this time was 1 mm, and the ambient temperature was 50 ° C. When the particles (A2) were observed with an electron microscope, it was observed that the particles (B) were fused and immobilized on the particles (A1) as shown in FIG. When the coverage of the particles (B) with respect to the particles (A1) was observed by an electron micrograph, about 70% of the surface was covered with the particles (B). To 100 parts of the particles (A2), 40 parts of the particles (C) were stirred and mixed for 3 minutes at a blade tip peripheral speed of 30 m / sec by the Henschel mixer shown in FIG. 1 to perform pretreatment. When the pretreated product is observed with an electron microscope, the particles (C) adhere to the particles (A1) which are mostly covered with the particles (B) and further above the particles (A2). Was observed. This pretreatment product is then
Using the apparatus shown in FIG. 1, processing was performed while circulating at a peripheral speed of 70 m / sec for 10 minutes to obtain a yellow non-magnetic microcapsule toner. The shortest gap at this time was set to 1 mm. The ambient temperature was 50 ° C. When the particles (microcapsule toner) are observed with an electron microscope, as shown in FIG. 8, the particles (C) are fused and fixed to the particles (A2), and the particles (C) are also fused to each other. Was observed. The entire surface of the particles (A2) was surrounded by the resin outer wall of the particles (C), and the coverage was about 100%. 0.5 part of colloidal silica (Talanox 500) was mixed with 100 parts of the microcapsule toner. A developer was prepared by mixing 10 parts of a microcapsule toner containing silica with 100 parts of a ferrite carrier prepared by coating ferrite particles having a particle size of 250 to 300 mesh with a fluororesin and an acrylic resin.
Tribo value of microcapsule toner at this time (23 ° C / 65
% Measured in an environment) was -25 μc / g. The tribo device mixes the microcapsule toner with the carrier under a mesh with a vacuum cleaner to separate the microcapsule toner that passes through the mesh and the carrier that does not pass through the mesh, and the amount of charge obtained through the mesh when passing through the mesh is stored in a capacitor. The amount of charge of the microcapsule toner per unit weight is calculated by accumulating. When this developer was used as an image forming apparatus in which Canon NP-5440 was used as a negatively chargeable microcapsule toner and the photosensitive drum was changed to a silicon drum to form an image, a clear image was obtained.

Comparative Example 1 In Example 1, 100 parts of the particles (A2) were added to the particles (C).
Was treated in the same manner as in Example 1 using 10 parts. Observation of the particles with an electron microscope revealed that about 1/4 of the surface of the particles (A2) (coverage of about 25%) was covered with the particles (C). After the colloidal silica was mixed, it was mixed with the carrier in the same manner as in Example 1 and the tribo was measured and found to be −8 μc / g. When an image was printed with the copying machine of Example 1, the image density was low and the image had a lot of fog.

Comparative Example 2 The particles (A2) themselves were added to colloidal silica and then mixed with a carrier, and the tribo was measured and found to be −6 μc / g. As a result, the image density was low and the image was more fogged than Comparative Example 1.

Comparative Example 3 In Example 1, 100 parts of the particles (A2) were added to the particles (C).
The same treatment as in Example 1 was carried out using 19 parts of When the particles were observed with an electron microscope, it was found that nearly half the surface area of the particles (A2) was covered with the particles (C) (coverage of 48%). After mixing colloidal silica and mixing with a carrier in the same manner as in Example 1, the tribo was measured.
It was μc / g. When an image was printed with the copying machine of Example 1, the image density was sufficient although it was inferior to that of Example 1, but the fog was clearly inferior to the microcapsule toner of Example 1.

Example 2 The same particles as in Example 1 were used as the particles (A1).

Preparation of colored particles (B): The above components were dispersed by heating with an attritor at 60 ° C. to obtain a monomer composition. It was prepared by adding 2 parts of 2,2'-azobis-2,4-dimethylvaleronitrile to the above monomer composition. Hydrophilic silica, Aerosil # 300 (Nippon Aerosil Co., Ltd.) 1 in a 2 liter stainless steel container containing 700 parts of distilled water
After adding 5 parts and adjusting the temperature to 60 ℃, TK homomixer 10,000 rpm
The above-mentioned monomer composition was charged under rotation, stirred for 60 minutes and pre-dispersed to prepare a dispersion liquid. Discharge pressure of this dispersion is 400kg / cm ² using a piston type high pressure homogenizer (15M-8TA).
Granulated in. After granulation, stir with paddle mixer for 8 hours
The polymerization was completed under the condition of 60 ° C. Thereafter, the mixture was cooled, washed with an aqueous sodium hydroxide solution, dehydrated and dried to obtain particles (B). Volume average particle diameter of the obtained particles (B)
It was 0.95 μm.

Preparation of particles (C): The above components were stirred at 60 ° C. to obtain a monomer composition. 2,2 ′
Prepared by adding 2 parts of azobis-2,4-dimethylvaleronitrile to the monomer composition. 12 parts of hydrophilic silica (Aerosil # 300) was placed in a stainless steel container with a capacity of 2 liters containing 700 parts of distilled water, and the temperature was adjusted to 60 ° C. Then, the above-mentioned monomer composition was put under TK homomixer 10,000 rpm rotation. Then, the mixture was stirred for 60 minutes and pre-dispersed to prepare a dispersion liquid. Discharge pressure of this dispersion is 400 kg / cm ² using a piston type high pressure homogenizer.
Granulated in. After granulation, continue stirring with a paddle mixer,
The polymerization was completed under the conditions of 60 ° C. for 8 hours. Then, it was cooled, washed with an aqueous sodium hydroxide solution, dehydrated and dried to obtain particles (C). Obtained particles (C)
The volume average diameter was 1.05 μm.

After pretreating 100 parts of the particles (A1) with 30 parts of the particles (B) with a Henschel mixer in the same manner as in Example 1,
In the apparatus shown in FIG. 1, particles (B) were used in the same manner as in the method of Example 1.
Were immobilized. However, the circulation time was 10 minutes, the shortest gap was 1 mm, and the ambient temperature was 55 ° C. Further, 45 parts of the particles (C) were pretreated in the same manner as in the method of Example 1 and then immobilized to perform encapsulation. The shortest gap at this time was 1 mm, and the ambient temperature was 60 ° C. When the obtained yellow microcapsule toner particles were observed with an electron microscope, the particles were almost entirely surrounded by the particles (C) (coverage rate 100%), and the surface was almost smooth. This microcapsule toner particles 100
0.8 part of colloidal silica treated with amino silicone oil was externally added to 10 parts of the mixture, and 10 parts of this mixture and 100 parts of the ferrite carrier were mixed to prepare a two-component developer.
When this developer was imaged using a modified NP-3525 machine manufactured by Canon Inc. (changed in the developing device configuration), an image free from fog and having a sufficient image density was obtained. The tribo of the microcapsule toner of this developer was +21 μc / g.

Comparative Example 4 The particles (A2) in Example 2 were used as yellow toner as they were, after externally adding colloidal silica in the same manner as in Example 2, and mixed with a carrier to obtain a developer. Tribo of this developer is +
It was 1.5 μc / g. Images were reproduced with a modified NP3525 machine, but the images were extremely thin and did not deserve evaluation.

Example 3 The above components were dispersed with an attritor at 135 ° C., taken out, cooled, and pulverized with a cutter mill. This was freeze-pulverized and then classified to obtain particles (A1) having a volume average diameter of 13.3 μm.
To 100 parts of the particles (A1), 5 parts of phthalocyanine blue itself (coloring agent) was used as the colored particles (B), and 0.2 parts of colloidal silica (Aerosil # 300) was used with a Henschel mixer FM10B at a peripheral speed of 20 m / sec for 1 minute. Pretreatment was performed. When observed with an electric microscope, the particles (B) and colloidal silica were uniformly attached to the surfaces of the particles (A1). Then, using the machine shown in Fig.2-1, the peripheral speed is 50m / se.
The treatment was carried out while circulating at c for 3 minutes. Shortest gap 2
mm, and the ambient temperature was 40 ° C. After 0.2 parts of colloidal silica (Aerogel # 300) was mixed with 100 parts of the particles (A2) having the particles (B) immobilized on the surface of the particles (A1) to improve fluidity, Example 2 After 40 parts of the particles (C) prepared in Step 1) were mixed and dispersed in a Henschel mixer and pretreated, the particles (C) were circulated for 8 minutes at a peripheral speed of 60 m / sec in the apparatus shown in FIG. ) Immobilized on the surface. The shortest gap was 2 mm and the ambient temperature was 45 ° C. When observed with an electron microscope, the surface of the particles (A2) was sufficiently covered with the particles (C) (coverage rate 100%). To 100 parts of the cyan microcapsule toner, 1.0 part of aminosilicone oil-treated silica was externally added and mixed, and then 6 parts of the mixture and 100 parts of the ferrite carrier were mixed to obtain a two-component developer. When an image was printed using a Canon PC-9 remodeling machine (with an increased fixing pressure) and a developing cartridge for PC-9, a very clear cyan image was obtained and no fog occurred. . The tribo of this microcapsule toner was +18 μc / g.

As described above, the microcapsule toner manufactured according to the present invention is a microcapsule toner that can obtain a good color image without fogging, and that is low in cost and can be sufficiently applied to color toners of high-mix low-volume production. is there. It is a method for producing a microcapsule toner capable of sufficiently exhibiting the properties of various materials.

Example 4 The above materials were mixed with an attritor at a temperature of 60 ° C. for 4 hours to prepare a monomer composition. 2, in the obtained monomer composition
2'-azobis- (2,4-dimethylvaleronitrile) 10
Part, and 1 part of 2,2'-azobisisobutyronitrile were added, and the mixture was mixed with 12 parts of hydrophilic colloidal silica (Aerosil # 200, manufactured by Nippon Aerosil Co., Ltd.) which is negatively charged in water. Ion exchange water 1200 heated to ℃
Part of the aqueous medium was added with stirring by a TK homomixer, and after the addition, the mixture was stirred at 10,000 rpm for 25 minutes for dispersion granulation. further,
The stirring was changed to paddle blade stirring, and stirring was carried out at 60 ° C. for 10 hours to complete the polymerization. After that, it is cooled, the surface of the polymer particles is washed with a sodium hydroxide solution to dissolve and remove silica, and washed with water,
Particles (A1) with a volume average diameter of 8.5μ after dehydration, drying and classification
Got The softening point of the particles (A1) was 115 ° C.

Fine powder of a mixed crystal of tin oxide and antimony oxide as the antistatic particles (B) (resistance value 1 to 5 Ω · cm, particle size 0.1 μ, density 6.
6. T-1) manufactured by Mitsubishi Metals Co., Ltd. was used. Particle (A1) 1
000 parts, 20 parts of particles (B) at 30 m / s by using the apparatus of FIG.
ec pretreated for 5 minutes. After that, particles (A2) were prepared by using the apparatus shown in FIG. 2 for 3 minutes at a minimum gap of 1 mm and a peripheral speed of 60 m / sec at the tip of the blade 15. The temperature inside the equipment in Fig. 2 is 50.
It was ℃. The coverage of the particles (A2) was 6.4%.

When observed with an electron microscope, the particles (A1) and the particles (B)
Was partially immobilized.

As the particles (C), fine particles of polymethylmethacrylate having an average particle size of 0.4 μm were used, and 120 parts of the particles (C) were added to 1000 parts of the particles (A2) using the apparatus shown in FIG.
Treated with ec for 5 minutes. Then, using the apparatus shown in FIG. 2-1, processing was performed for 3 minutes at a minimum gap of 1 mm and a blade peripheral speed of 70 m / sec. The temperature inside the device was 75 ° C. The coverage of the particles (A2) with the particles (C) was 70%.

When observed with an electron microscope, the particles (C) were converted into particles (A2)
Were observed to be immobilized.

To 100 parts of the microcapsule toner, 0.5 part of colloidal silica treated with amino silicone oil was externally added and mixed.

The surface of 100 parts of ferrite particles having a particle size of 250 to 300 mesh was coated with 0.8 part of a silicone resin to obtain magnetic particles. A two-component developer was prepared by mixing 10 parts of the toner having colloidal silica on the surface thereof and 100 parts of magnetic particles.

Images were printed with the above developer using a Canon copier NP-3525. Good images can be obtained at room temperature and normal humidity, no charge-up phenomenon is observed in continuous copying even at low temperature and low humidity (15 ° C, 10% RH), and there is little fog, and good images are obtained without image deletion. Was given.

Example 5 After heat-kneading the components of the above formulation with a roll mill (150 ° C) for about 30 minutes and cooling the resulting kneaded product, use a pulverizer to add about 10μ
The powder was pulverized to m (volume average diameter), and coarse powder and fine powder were cut by two zigzag classifiers manufactured by Alpine Co., Ltd. so that the volume average particle diameter was about 9 μm, to obtain (A1). The softening point of the particles (A1) was 120 ° C.

First, 20 parts of the particles (B) of Example 4 were added to 1000 parts of the particles (A1).
It processed at 30 m / sec and 5 minutes using the apparatus of a figure. Then, the shortest gap of 1 mm and 60 m / sec was applied for 5 minutes using the apparatus shown in FIG. 2-1 to obtain particles (A2). The temperature inside the machine was 55 ° C. The coverage was 6.8%.

To 1000 parts of the obtained particles (A2), the particles (C) 140 of polymethylmethacrylate having an average particle diameter of 0.4 μm were added in the same manner as in Example 4.
A part was pretreated by using the apparatus shown in FIG. 1 for a peripheral speed of the stirring blade of 30 m / sec for 5 minutes. Then, using the apparatus shown in FIG. 2-1, the shortest gap was 1 mm, the blade peripheral speed was 70 m / sec, and the treatment was performed for 3 minutes.
The temperature inside the machine was 80 ° C. Particles (A2) by particles (C)
The coverage was 82%.

When observed with an electron microscope, the particles (A2) and the particles (B)
Were observed to be immobilized.

Thereafter, image formation was performed in the same manner as in Example 4. Fogging was small and good in continuous image formation, and good images were obtained.

Example 6 The above components were mixed with an attritor at a temperature of 60 ° C. for 4 hours to prepare a monomer composition. 2, in the obtained monomer composition
2'-azobis- (2,4-dimethylvaleronitrile) 10
Part, and 1 part of 2,2′-azobisisobutyronitrile were added and mixed, and 100 parts of silica having amino groups (colloidal silica (Aerosil # 200) was added with 5 parts of aminopropyltriethoxysilane). Treated)) 12 parts and 0.1 parts of 0.1N hydrochloric acid, 15 parts was added to the aqueous medium of 1200 parts of ion-exchanged water heated to 60 ° C under stirring of TK homomixer, and stirred at 10,000 rpm for 15 minutes after the addition. It was dispersed and granulated.

Further, stirring was changed to paddle blade stirring, and stirring was carried out at 60 ° C. for 10 hours to complete the polymerization. After cooling, wash with sodium hydroxide solution to dissolve and remove amino-modified silica, wash with water, dehydrate, dry and classify to obtain particles with a volume average diameter of 8.5μ (A
1) got. The softening point of the particles (A1) was 115 ° C.

When the antistatic particles (B) and the particles (C) of Example 4 were similarly immobilized, a phenomenon agent was prepared in the same manner, and image formation was performed using the phenomenon apparatus shown in FIG. , A good image was obtained.

In the apparatus of this embodiment, the photoconductor drum 103 is 6 in the direction of arrow a.
It rotates at a peripheral speed of 0 mm / sec. 122 is a stainless steel (SUS 304) sleeve with an outer diameter of 32 mm and a thickness of 0.8 mm that rotates in the direction of arrow b at a peripheral speed of 66 mm / sec. The surface of the sleeve is amorphous sand with # 600 alundum abrasive grains. Plast was applied to make the roughness of the circumferential surface 0.8 μm (Rz =).

On the other hand, a ferrite sintered type magnet 123 is fixedly arranged in the rotating sleeve 112, the magnetic pole arrangement is as shown in FIG. 5, and the maximum value of the surface magnetic flux density is about 800 gauss. The non-magnetic blade 124 is made of non-magnetic stainless steel having a thickness of 1.2 mm. The blade sleeve gap was 400 μm.

On the surface of the photosensitive drum 103 facing the sleeve 122,
As an electrostatic latent image, a charge pattern of +150 V in the dark part and +150 V in the bright part was formed, and the distance from the sleeve surface was set to 300 μm. Then, a frequency of 800 Hz is applied to the sleeve by a power supply 134
The phenomenon was performed by applying a voltage having a peak-to-peak value of 1.4 KV and a center value of +300 V.

Comparative Example 5 To 100 parts of the particles (A1) of Example 4, 0.5 part of colloidal silica treated with aminosilicone oil was externally added. Less than,
When images were printed in the same manner as in Example 4, fog was observed in continuous copying.

Comparative Example 6 To 100 parts of the formulation of the particles (A1) of Example 5, 0.2 parts of antistatic particles (B) were added, kneaded in the same manner as above, cooled, pulverized and classified, and toner having a volume average diameter of 9 μm. Got After that, when image formation was performed in the same manner as in Example 4, fog was observed in continuous image formation.

INDUSTRIAL APPLICABILITY The method for producing a microcapsule toner of the present invention can easily produce a microcapsule toner that can obtain a high-quality image even under various environments, and is industrially very useful.

Example 7 Preparation of colored particles (A1): The above components were mixed by using an attritor at 70 ° C. for 5 hours to prepare a monomer composition. Using a TK homomixer (made by Tokushu Kika Kogyo), the obtained monomer composition was
2'-azobis- (2,4-dimethylvaleronitrile) 10
Parts, 2,2'-azobisisobutyronitrile 1 part, amino-modified silica (100 parts of Aerosil # 200 treated with 5 parts aminopropyltriethoxysilane) 10 parts, 0.1N hydrochloric acid 15 parts Add while stirring in an aqueous medium of 1200 parts of ion-exchanged water heated to 60 ° C, and after 90 minutes for 90 minutes
Dispersion granulation was performed by stirring at 00 rpm.

Further, the stirring was changed to paddle blade stirring, and stirring was carried out at 60 ° C. for 10 hours to complete the polymerization. After cooling, wash with sodium hydroxide solution to remove amino-modified silica, wash with water,
The dehydration was repeated twice, and a drying step at 40 ° C. for 24 hours was performed to obtain particles (A1) having a volume average diameter of 10.0 μm.

Preparation of Abrasive Particles (B): Cerium oxide particles (CeO ₂ main component) were removed by a wind classifier to remove coarse powder, and particles (B) having a volume average particle size of 1.0 μm.
Got

Preparation of outer shell-forming particles (C): The above components were mixed with an attritor at a temperature of 60 ° C. for 4 hours to obtain a monomer composition, to which 5 parts of 2,2′-azobis- (2,4-dimethylvaleronitrile) was added and mixed, The mixture was added to ion-exchanged water containing 10 parts of modified silica and 15 parts of 0.1N hydrochloric acid and heated to 60 ° C., and stirred at 9000 rpm for 30 minutes with a TK homomixer. The dispersion thus obtained was granulated at a discharge pressure of 400 kg · cm ⁻² using a piston type high pressure homogenizer (manufactured by Gorin Co., model 15M-8TA). Further, polymerization was carried out by stirring with a paddle mixer at 60 ° C. for 10 hours. After cooling, wash with sodium hydroxide solution to remove amino-modified silica, wash with water,
Repeat dehydration twice, and go through a drying process at 40 ° C for 24 hours,
Particles (C) having a volume average particle diameter of 1.5 μm were obtained.

20 parts of particles (B) were added to 100 parts of colored particles (A1) obtained as described above, and Henschel mixer FM10 shown in FIG.
B (manufactured by Mitsui Miike Industry Co., Ltd.) was pretreated by mixing at a peripheral speed of 50 m · S ⁻¹ for 3 minutes. After that, the second
Using the apparatus shown in Fig. 1, the immobilization treatment was performed at the shortest gap of 1 mm, 60 m · S ^-1 , 5 minutes (atmosphere temperature 50 ° C). When the obtained colored particles (A2) were observed under an electron microscope, it was confirmed that the abrasive particles (B) were partially fixed. The coverage at this time was 75%.

Henschel mixer FM10 shown in FIG. 1 was prepared by adding 30 parts of outer shell forming resin particles (C) to 100 parts of the obtained colored particles (A2).
Pretreatment was carried out by mixing with B at a peripheral speed of 30 m · S ⁻¹ for 3 minutes. Then, using the apparatus of FIG.
The shortest gap was 1 mm, 50 m · S ⁻¹ for 3 minutes (atmosphere temperature 50 ° C.) to obtain microcapsule toner. The microcapsule toner particles obtained were about 90 when observed with an electron microscope.
% Was covered with the resin for the outer shell. To 100 parts of the above microcapsule toner, 0.5 part of colloidal silica treated with aminosilicon oil and 0.1 part of polyvinylidene fluoride particles (volume average particle size 3.5 μm) were externally added by a Henschel mixer and mixed.

25 parts of the above toner mixture were coated with silicone resin
Two-component developer was prepared by mixing 100 parts of a 0-300 mesh ferrite carrier.

Under normal temperature and normal humidity environment of this two-component developer (23 ℃, 65% RH)
The tribo value at was −20 μc / g. Using this developer, a Canon copier NP-270RE remodeling machine (remodeled for two-component developer) was used to continuously copy 5000 sheets. Fog was good and no image deletion was observed. It was The image density (Macbeth densitometer) was stable at 1.40 from the beginning, and when the drum was observed after running, no fusion of the microcapsule toner was observed.

Example 8 Example 7 was used as the colored particles (A1) and the abrasive particles (B).
Colored particles (A2)
Got

Preparation of outer shell forming particles (C) The above components were mixed with an attritor at a temperature of 80 ° C. for 4 hours to obtain a monomer composition, and 2,2′-azobis- (2,4-
2 parts dimethyl valeronitrile) and amino-modified silica 10
Parts and 20 parts of 0.1N hydrochloric acid were added to ion-exchanged water heated at 70 ° C., and the mixture was stirred at 9000 rpm for 40 minutes using a homomixer. This dispersion was granulated at a discharge pressure of 400 kg · cm ⁻² using a piston type high pressure homogenizer. Furthermore, the mixture was stirred by a paddle mixer at 60 ° C. for 10 hours to complete the polymerization. Then, the mixture was cooled, washed with sodium hydroxide to remove the amino-modified silica, washed with water and dehydrated twice, and dried. The volume average particle diameter of the particles (C) obtained at this time was 0.9 μm.

Next, 100 parts of the colored particles (A2) were pretreated with 25 parts of the resin (C) for outer shell in a Henschel mixer in the same manner as in Example 7, and then shown in FIG. 2-1. Using the apparatus described above, the shell material was fixed on the surface of the colored particles by the same operation as in Example 7 to obtain a microcapsule toner. Observation with an electron microscope revealed that about 90% of the surface of the particles (A2) was covered with the particles (C).

To this microcapsule toner, colloidal silica and polyvinylidene fluoride were externally added and mixed in the same manner as in Example 7. Further, 10 parts of this microcapsule toner mixture was mixed with 100 parts of the same carrier as in Example 7 to obtain a developer.

A continuous copy of this developer was made in a high temperature and high humidity environment (32 ° C, 85% RH) using a machine with an improved NP-3525 developing machine configuration, but the image density was stable at about 1.20 to 1.25. No fogging or image deletion occurred. When observing the drum after copying 6000 sheets, the surface is unevenly printed,
No fusion of the microcapsule toner was observed. The tribo of this microcapsule toner was +18 μc · g ⁻¹ in an environment of 23 ° C. and 65% RH, and the fluidity of the microcapsule toner was also satisfactory.

Example 9 The particles (A1) were prepared as follows.

Each component of the above formulation was melted and mixed at 150 ° C, and sprayed, cooled, and solidified by a two-fluid nozzle whose air temperature was set at 120 ° C. The volume average particle diameter of the obtained particles (A1) was 10.5 μm.

As the abrasive particles (B), strontium titanate (SrTiO ₃ ) was applied to an air classifier to obtain a volume average particle size of 1.0 μm.
m was obtained and used as abrasive particles (B).
The same particles as in Example 18 were used as the particles (C).

The particles (A1) and particles (B) obtained as described above are pretreated in the same manner as in Example 7, and then the 2-1.
Immobilization was performed by the apparatus shown in the figure. At this time, the atmospheric temperature was 50 ° C, the processing time was 4 minutes, and the shortest gap was 1 mm. The surface of the colored particles (A2) thus obtained is about
It was coated with 70% strontium titanate fine powder. Next, the particles (A2) and the particles (C) used in Example 18 were mixed in a weight ratio of 100: 25 (set film thickness 0.5 μm).
And mix with a Henschel mixer for 3 minutes at a wind speed of 40 m · S ^-1 ,
Pretreatment was performed. The device shown in FIG. 2-1 was used for immobilization, and the treatment time was 3 minutes to obtain a microcapsule toner. To the obtained microcapsule toner, 0.6 part of colloidal silica and 0.4 part of zinc stearate were externally added and mixed to prepare a one-component type developer, and the tribo was measured to be +22 μc / g. As a result of observation, the surface of the particles (A2) was sufficiently covered with the particles (C) (100% coverage), and the outer shape of the microcapsule toner particles was close to a uniform spherical shape.

When a one-component developer having this microcapsule toner was used for image formation using a Canon Copier PC-9, image sharpness, fog, and image density were at satisfactory levels. The fusion of the microcapsule toner of No. 1 was not seen in the paper passing up to 2000 sheets.

Example 10 The particles (A1) were produced in the same manner as in Example 7 except that CI Basic Red 1 (CI45160) was used in place of the carbon black of Example 7. The particles (B) and (C) used were the same as in Example 8, and the particles were immobilized with the same formulation as in Example 8 to obtain a microcapsule toner. A microcapsule toner mixture was prepared by mixing 0.6 parts of colloidal silica and 0.3 part of zinc stearate with 100 parts of the above microcapsule toner using a Henschel mixer. To 100 parts of a ferrite carrier in which ferrite particles having a particle size of 250 to 300 mesh were coated with a fluororesin and an acrylic resin, 10 parts of a microcapsule toner mixture was mixed to obtain a two-component developer. The microcapsule toner tribo value at this time is 23.
It was +20 μc / g in the environment of ℃ and 65% RH. When this developer was put in a color cartridge for Canon PC-7 PC, and 3000 sheets were continuously passed through PC-7 in an environment of 32 ° C and 20% RH, good image quality was obtained from beginning to end. I was able to get it.

Example 11 Microencapsulation was performed in the same formulation as in Example 7 except that fine strontium titanate powder (SrTiO ₃ ) treated with a silane coupling agent was used in the particles (B), and the evaluation method was the same. By the way. The image evaluation results were sufficiently satisfactory in terms of density, fog, and image deletion.

Comparative Example 5 In Example 7, except that the particles (B) were not added.
A developer was manufactured according to the same formulation as in Example 7. Tribo of this developer at 23 ° C. and 65% RH was −18 μc / g. When this developer was imaged in the same manner as in Example 7, the image density was 1.35. However, from around 500 sheets, black spots appeared on the copy image due to poor cleaning of the photosensitive drum. There has occurred.

Comparative Example 6 Microencapsulation was performed in the same manner as in Example 7 except that the amount of the particles (C) was changed to 10 parts based on 100 parts of the particles (A2). When the obtained microcapsule toner was observed with an electron microscope, about 20% of the particles (A2) were covered with the particles (C). When this microcapsule toner was externally added and imaged in the same manner as in Example 7,
Fog was severe and the image density was as low as 1.0. The tribo value at this time was −4 μc / g.

As described above, the microcapsule toner manufactured according to the present invention does not cause fusion of the microcapsule toner onto the photosensitive drum even in continuous copying, the image density is stable, and a good image without fog is obtained. . Since the production method of the present invention is encapsulation by a dry method, it is possible to save the labor such as recovery of an organic solvent and also to reduce the cost, and to produce the microcapsule toner capable of sufficiently exhibiting the characteristics of various materials. Is the way.

[Brief description of drawings]

In the accompanying drawings, FIG. 1 is a diagram schematically showing an example of a stirring device for pretreating particles (A1) and particles (B) or particles (A2) and particles (C). . FIG. 2-1 is a diagram schematically showing an example of an apparatus for immobilizing particles (B) on particles (A1) or particles (B) on particles (A2), and FIG. FIG. 2 is a partially enlarged view of the device of FIG. 2-1. FIG. 3-1 is a diagram schematically showing another example of an apparatus for immobilizing particles (B) on particles (A1) and particles (C) on particles (A2). -2 and Fig. 3-3 are partial views of the device of Fig. 3-1. FIG. 4-1 is a view schematically showing an example of a pin mill system for immobilizing particles (B) on particles (A1) and particles (C) on particles (A2). -2 shows a partial view of the device of Fig. 4-1. FIG. 5 is a schematic view of an image forming apparatus used for image formation using the microcapsule toner of the present invention, and FIGS. 6 and 7 are the apparatus of FIG. FIG. 3 is an enlarged view of the developing area in FIG. FIG. 8 is a diagram schematically showing a cross section of the microcapsule toner according to the present invention. FIG. 9 is a diagram schematically showing an apparatus for measuring the resistance of antistatic particles. 1,1a, 1b: Jacket, 19: Impact part 2: Stirrer, 20: Inlet chamber 3: Control plate, 21: Outlet chamber 4,4b: Cylinder, 22,22b, 22c: Return path 5: Direction control unit, 23,23b, 23c: Product outlet 6: Discharge port, 24,24b, 24c: Raw material inlet 12,12b, 12c: Rotating shaft, 25,25c: Blower 13,13b, 13c: Rotor, 30: Blower blade 14 : Dispersion blade, 31: With rotor blade 15: Rotating piece (blade), 32, 32c: Outlet 16: Partition disk, 36, 36c: Inlet 17,17b, 17c: Casing, 39: Fixed pin 18: Liner, 40 : Rotating pin

Front page continued (72) Inventor Atsuko Kobayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masuo Yamazaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Yusuke Karami 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) Reference JP-A-63-311264 (JP, A) JP-A-64-63035 (JP, A) ) JP-A 64-62666 (JP, A)

Claims (4)

[Claims] 1. A microcapsule toner having core particles and an outer shell, wherein particles having at least a binder resin (A
1) and particles (B) having a particle size ratio of 0.2 or less with respect to the particles (A1) (provided that the particles (B) are colored particles, antistatic particles or abrasive particles) at an ambient temperature of 10 Under the condition of ~ 90 ℃, it passes through the impact part with the shortest gap of 0.5 to 5 mm formed from the rotating piece and the fixed piece or the impact part with the shortest gap of 0.5 to 5 mm formed from at least two kinds of rotating pieces. Then, the particles (B) are fixed on the surface of the particles (A1) by mechanical impact in the impact part to form the particles (A2), and the outer shell having a particle size ratio of 0.2 or less with respect to the particles (A2) is formed. The resin particles (C) for use are formed from an impact part having a shortest gap of 0.5 to 5 mm formed from a rotating piece and a fixed piece or at least two kinds of rotating pieces under an atmosphere temperature of 10 to 90 ° C.
It has an outer shell formed by passing through an impact part having a shortest gap of 0.5 to 5 mm and fixing the outer shell forming resin particles (C) on the surface of the particles (A2) by a mechanical impact in the impact part. A microcapsule toner characterized by the above. 2. The microcapsule toner according to claim 1, wherein the coating rate of the outer shell forming resin particles (C) on the surface of the particles (A2) is 51 to 100%. 3. Particles (A1) having at least a binder resin, and particles (B) having a particle size ratio of 0.2 or less with respect to the particles (A1) (provided that the particles (B) are colored particles and antistatic). Particles or abrasive particles) is formed from an impact part having a minimum gap of 0.5 to 5 mm formed from a rotating piece and a fixed piece or at least two kinds of rotating pieces under the condition of an ambient temperature of 10 to 90 ° C. Pass the impact part with the shortest gap of 0.5 ~ 5 mm,
An outer shell forming resin having a particle ratio of 0.2 or less with respect to the particles (A2) by fixing the particles (B) on the surface of the particles (A1) by mechanical impact in the impact part. Particles (C) are formed from an impact part having a shortest gap of 0.5 to 5 mm formed from a rotating piece and a fixed piece or at least two kinds of rotating pieces under an atmosphere temperature of 10 to 90 ° C.
The outer shell is formed by passing through an impact part having a shortest gap of 0.5 to 5 mm and fixing the outer shell-forming resin particles (C) on the surface of the particles (A2) by a mechanical impact at the impact part. And a method for producing a microcapsule toner. 4. The method for producing a microcapsule toner according to claim 3, wherein the surface of the particles (A2) is coated with the outer shell forming resin particles (C) so as to have a coverage of 51 to 100% and fixed.