JPH09101630A - Electrostatic charge image developing toner and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce an electrostatic charge image developing toner in which an external additive is softly and uniformly fixed to the surface of color resin particles so as to realize stable image density and transfer characteristics for a long time in a multiple development and simultaneous transfer process capable of miniaturizing a device with good color registering. SOLUTION: This toner is produced by adding fine particles to color particles comprising at least a resin and a coloring agent so as to fix the fine particles to the surface of the color particles. The fixing process is carried out under such conditions that the color particles and the fine particles are mixed in the presence of a mixing medium which is substantially sphere, that the temp. of the color particles (fixing temp.) during mixing is controlled to the range expressed by (Tg-20 deg.C)<=(fixing temp.)<=(Tg+20 deg.C), wherein Tg is the glass transition temp. ( deg.C) of the resin, and that the mixing medium is removed after the treatment.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a two-component electrostatic image developing toner for electrophotographic copying machines and printers.

[0002]

2. Description of the Related Art Conventionally, in copying machines and printers using an electrophotographic method, a method of visualizing an electrostatic latent image using resin particles containing a coloring agent is generally used. External additives are used for the purpose of charge control, improvement of fluidity and the like. In particular, as described in JP-A-62-182775, an external additive having a relatively small particle size is added because it has a great effect of improving the fluidity. However, when such an external additive having a small particle size is added, the external additive is buried in the toner due to the stress generated in the developing device, the charge amount is changed, and the transferability is deteriorated. Have.

In a color copying machine or a color printer, a method of forming an image by superimposing a plurality of basic colors is generally used. For the purpose of downsizing and preventing color misregistration, a developer is used as a photoreceptor. On the other hand, a non-contact development batch transfer method has been proposed in which development is carried out in a non-contact state, all the colors are superposed on a photoconductor, and then they are collectively transferred to a transfer paper.

In such a process, the physical adhesive force between the toner and the carrier contributes to the developability during development.
That is, the burial of the external additive increases the physical adhesive force to cause a decrease in developability, and also causes transfer unevenness during batch transfer. In order to solve such a problem, JP-A-58-1
No. 157, a method using an external additive having a large particle diameter, and JP-A-48-8141 disclose a method using organic fine particles as an external additive having a large particle diameter. Furthermore, JP-A-57
It is also known to add two kinds of external additives having different particle sizes such as No. 179866. When such two kinds of external additives having a small particle size and a large particle size are added, the burying of the external additive can be suppressed, and an excellent toner having stable chargeability, developability and transferability can be obtained for a long period of time. . However, when such an external additive having a large particle size is used, the external additive is likely to be separated from the toner, and the charge amount changes due to contamination of the carrier surface. In addition, the released external additive may cause scratches on the drum or scratches on the blade, or in some cases form an aggregate,
A slip phenomenon occurs on the rotating sleeve, which causes a low image density in the developed image portion and causes image defects such as a white portion not being developed.

In order to solve such a problem, Japanese Patent Laid-Open No. 2-1
67561, JP-A-4-328579, and JP-A-4-328579.
No. 335357 discloses a method of fixing an external additive hard. Conventionally, as a method of immobilizing this hard, a mechanical impact force is applied by using a fine particle compounding device having a stirring blade or a rotor that rotates at a high speed in a batch system such as a hybridization system. There is known a technique of immobilizing fine particles by imprinting them on the surface of the colored particles. However, when it is immobilized by such a method, it is difficult to be uniformly immobilized on the surface of the colored resin particles, and the distribution of the charge amount may be widened or sufficient fluidity may not be obtained.

In order to solve such a problem, there is known a method of softly fixing an external additive such as stirring and mixing a toner at a high temperature (Japanese Patent Laid-Open No. 63-131149).
issue). However, in a conventional mixer, for example, a fixed container type mixer having a stirring blade such as a Henschel mixer or a container rotating type mixer such as a V type mixer, when mixing at high temperature is performed, the colored particles Aggregates may form. Therefore, there is a problem that the particle size distribution is changed and the agglomerates must be removed by performing a sieving process.

[0007]

SUMMARY OF THE INVENTION The object of the present invention is to softly immobilize fine particles of 50 to 1000 nm on the surface of colored particles to provide stable chargeability and high and stable transferability for a long period of time. Maintains stable image density for a long period of time even in multiple development and batch transfer process for the purpose of maintaining compactness and preventing color shift, and realizes stable transfer characteristics. It is an object of the present invention to provide a means for manufacturing an electrostatic charge developing toner.

[0008]

In order to achieve the above object, the toner for developing an electrostatic image of the present invention comprises fine particles added to at least colored resin particles, and the fine particles form 10 to 90 on the surface of the colored particles. It is characterized by being fixed at a fixing rate of%. Further, in the production method for obtaining the toner, the colored particles and the fine particles are mixed in the presence of a substantially spherical mixed medium, and the temperature of the colored particles at the time of mixing is Tg which is the glass transition temperature of the resin. Sometimes, the treatment is performed in a temperature range of Tg−20 ° C. ≦ fixing treatment temperature ≦ Tg + 20 ° C. The term “substantially spherical” in the present invention means that the mixed medium has a spherical shape or an elliptical shape close to a spherical shape.
Specifically, the average ratio a / b of the minor axis a and the major axis b of the mixed medium is a /
b is preferably 0.8 to 1.0, and particularly 0.9
It is preferable that it is ~ 1.0. By using such a substantially spherical mixed medium, the immobilized state of the fine particles on the surface of the colored particles can be made sufficiently uniform. The volume average particle size of the mixed medium is the average of the major axis and the minor axis, and is preferably 0.1 to 10 mm, and particularly preferably 0.1.
5-5 mm is preferred. Further, the specific gravity of the mixed medium is preferably 2.0 to 4.0. Furthermore, the filling ratio of the mixed medium and the colored particles is as follows: mixed medium: colored particles = 1:
Preference is given to treatment with a volume ratio of 2 to 2: 1. The material of the mixed medium is appropriately selected in consideration of its specific gravity and the contamination property (contamination property) with the mixed colored particles and fine particles. Specifically, it is selected from plastic, iron, glass, alumina, zirconia, silicon nitride and the like.

According to another aspect of the present invention, the manufacturing method for obtaining the toner is characterized in that after the preliminary mixing step of the colored particles and the fine particles, the fixing step is carried out. When the temperature of the colored particles is Tg which is the glass transition temperature (° C) of the resin, the premixing temperature ≤ Tg-30 ° C.
Perform within the temperature range. The temperature of the colored particles during the fixing step is
It is preferable to perform the treatment within a temperature range of Tg−20 ° C. ≦ immobilization treatment temperature ≦ Tg + 20 ° C. In the present invention, the peripheral speed of the stirring blade during mixing is such that the premixing speed is ≧ 30 m / sec, 1
It is preferable that the relationship of 0 m / sec ≦ immobilization processing speed ≦ 40 m / sec is satisfied. In addition, it is preferable to hold for 1 min.ltoreq.holding time.ltoreq.60 min within the processing temperature range during the immobilization step. Furthermore, it is preferable to adjust the product temperature within a speed range of 1.0 ° C./min≦temperature rise and temperature decrease ≦ 5.0 ° C./min. This makes it possible to obtain good results without using the mixed medium used in the former case.

The fine particles used in the present invention preferably have a volume average particle diameter of 50 to 1000 nm, and the fine particles may be inorganic fine particles or resin fine particles.

The present invention will be specifically described below.

In the two-component developer, inorganic or organic fine particles are generally added externally in order to secure fluidity and chargeability, but the fluidity imparting effect becomes greater as the particle size becomes smaller. The chargeability is controlled by the external additive on the outermost surface in contact with the carrier and can be controlled by controlling the chargeability on the surface of the external additive, but the particle size of the external additive is too small or the external impact is applied. When the toner is buried in the toner, the toner surface comes into contact with the carrier, and the chargeability of the toner begins to affect, and the chargeability changes. On the other hand, when a large particle size external additive is used, it is possible to prevent the external additive from being buried, but since the particle size becomes large, the fluidity deteriorates, and the adhesive strength with the resin particle surface is weak, so external addition The release of the agent causes a change in the charge amount due to the contamination of the carrier surface, and a defect such as a drum scratch or a blade scratch due to the free external additive and an image defect due to the formation of an aggregate.

Therefore, according to the present invention, in order to prevent detachment of the external additive having a large particle diameter, in the presence of a substantially spherical mixed medium,
The resin particles and the external additive are stirred and mixed under the condition of Tg−20 ° C. ≦ immobilization treatment temperature ≦ Tg + 20 ° C. to uniformly fix the external additive on the surface of the resin particles. This fixed state is determined by the following formula from the BET specific surface areas of the external additive and the toner.
d has been defined.

[0014]

(Equation 1)

[0015] Immobilization Toner: BET specific surface area of immobilized toner (m ² / g) Untreated Toner: BET specific surface area of the untreated toner (m ² /
g) Added external additive: BET specific surface area (m ^{2 of the} added external additive)
/ G) The BET specific surface area is Flow manufactured by Shimadzu Corporation.
It is measured by the BET one-point method using sorb 2300.

When the temperature range is Tg-20 ° C. or lower, the immobilization rate Fd does not reach 10%, and the fine particles are simply attached to the surface of the colored particles. Problem occurs. Further, at Tg + 20 ° C. or higher, the fixing ratio Fd exceeds 90%, the external additive fine particles are excessively fixed, and the influence of the colored particle surface becomes large,
The effect of the large particle size external additive is lost. In addition, aggregation occurs between toner particles, the particle size distribution changes, the charge amount changes,
Toner scattering and image deterioration occur. On the other hand, Tg-20 ° C
Even when the treatment strength was increased below and the fixation was attempted, the impact strength enough to drive the external additive could not be imparted with the strength of the mixed medium, and the fixation ratio Fd was insufficient at 10% or less. Even if the immobilization rate Fd at this time becomes 10% or more, it becomes a hard immobilization state, and the desired effect cannot be obtained.

Further, in order to reduce the effect of imparting fluidity, which has been a problem in the case of adding an external additive having a large particle diameter, Tg-20 ° C ≤ fixed in the presence of a substantially spherical mixed medium. It was found that the improvement can be achieved by treating in the temperature range of chemical treatment temperature ≦ Tg + 20 ° C.

The external additive preferably has a particle size of 50 nm or more in order to exert the above-mentioned excellent effects. 5
If the particle size is 0 nm or less, the effect of suppressing the embedding, which is a feature of the large particle size external additive, cannot be obtained, and the particles are completely buried by immobilization. In addition, when the particle size is 1000 nm or more, the fluidity is remarkably reduced, and it cannot be improved even if the treatment is carried out in the above temperature range.

The toner used in the present invention is a toner obtained by adding the fine particles of the present invention to colored particles containing a binder resin, a colorant, and other additives used as necessary. The average particle size is a volume average particle size and is usually 1 to 30 μm.
m, preferably 5 to 15 μm.

The binder resin constituting the colored particles is not particularly limited, and various conventionally known resins can be used. For example, a styrene resin, an acrylic resin, a styrene / acrylic resin, a polyester resin, and the like can be given. Here, the glass transition temperature of the resin is 45 to 70 ° C., preferably 52 to 6 ° C. for improving fixing property and blocking property.
5 ° C. When this temperature is low, the fine particles are fixed well, but the blocking property is reduced, and the so-called aggregation inside the developing device and the problem of fusion of the toner to the carrier occur. On the other hand, when the glass transition temperature is high, the problem of blocking does not occur, but the adhesiveness to paper is lowered, and the fixing property is lowered.

The colorant is not particularly limited, and carbon black, nigrosine dye, aniline blue, calcoil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, and phthalocyanine, which are conventionally known for toners, are known. Examples include blue, malachite green oxalate, and rose bengal.

For example, as the black toner, carbon black / nigrosine dye or the like is used, and yellow, magenta,
Examples of pigments required for cyan toner include C.I. I. Pigment Blue 15: 3, C.I. I. Pigment Blue 15,
C. I. Pigment Blue 15: 6, C.I. I. Pigment Blue 68, C.I. I. Pigment Red 48-3,
C. I. Pigment Red 122, C.I. I. Pigment Red 212, C.I. I. Pigment Red 57-1,
C. I. Pigment Yellow 17, C.I. I. Pigment Yellow 81, C.I. I. Pigment Yellow-154 and the like can be preferably used.

Examples of the other additives include charge control agents such as salicylic acid derivatives and azo metal complexes, and fixability improving agents such as low molecular weight polyolefins and carnauba wax.

Various inorganic oxides, nitrides, borides and the like are preferably used as the inorganic fine particles for constituting the present invention. For example, silica, alumina, titania, zirconia, barium titanate, aluminum titanate, strontium titanate, magnesium titanate, cerium oxide, zinc oxide, chromium oxide, cerium oxide, antimony oxide, tungsten oxide, tin oxide, tellurium oxide, Examples thereof include manganese oxide, boron oxide, silicon carbide, boron carbide, titanium carbide, silicon nitride, titanium nitride and boron nitride. Further, the inorganic fine particles may be subjected to a hydrophobic treatment. When carrying out the hydrophobic treatment, it is preferable to perform the hydrophobic treatment with various titanium coupling agents, so-called coupling agents such as silane coupling agents,
Furthermore, aluminum stearate, zinc stearate,
A hydrophobic treatment with a higher fatty acid metal salt such as calcium stearate is also preferably used.

Examples of materials for hydrophobizing are titanium coupling agents such as tetrabutyl titanate, tetraoctyl titanate, isopropyl triisostearoyl titanate, isopropyl tridecylbenzene sulfonyl titanate, bis (dioctyl pyrophosphate) oxyacetate. There are titanates. Further, as the silane coupling agent, γ- (2-aminoethyl) aminopropyltrimethoxysilane, γ- (2
-Aminoethyl) aminopropylmethyldimethoxysilane, γ-methacryloxypropyltrimethoxysilane,
N-β- (N-vinylbenzylaminoethyl) γ-aminopropyltrimethoxysilane hydrochloride, hexamethyldisilazane, methyltrimethoxysilane, butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane Silane,
Examples thereof include decyltrimethoxysilane, dodecyltrimethoxysilane, phenyltrimethoxysilane, o-methylphenyltrimethoxysilane and p-methylphenyltrimethoxysilane.

Furthermore, silicone oil obtained by amino-modifying polysiloxane can also be used. An example of this is γ- (2-aminoethyl) with respect to polysiloxane.
Examples include those treated with aminopropylmethyldimethoxysilane.

Examples of the fatty acid and its metal salt include undecyl acid, lauric acid, tridecyl acid, dodecyl acid, myristic acid, palmitic acid, pentadecyl acid, stearic acid, heptadecyl acid, arachidic acid, montanic acid, oleic acid, linoleic acid, Examples include long-chain fatty acids such as arachidonic acid, and their metal salts include zinc, iron, magnesium,
Salts with metals such as aluminum, calcium, sodium, lithium and the like can be mentioned.

These compounds are preferably added in an amount of 1 to 10% by weight based on the weight of the inorganic fine particles, and are preferably coated.
It is 3 to 7% by weight. Further, these materials can be used in combination.

On the other hand, the composition of the resin fine particles for constituting the present invention is not particularly limited. Generally, vinyl-based organic fine particles are preferable. The reason for this is that it can be easily produced by a production method such as an emulsion polymerization method or a suspension polymerization method. In particular,
Styrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, α-methylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-phenylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pt-butylstyrene, pn- Styrene or styrene derivatives such as hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, methyl methacrylate, ethyl methacrylate, n-methacrylic acid Butyl, isopropyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, diethylaminoethyl methacrylate, dimethylaminoethyl methacrylate Methacrylic acid ester derivatives and the like,
Methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, t-butyl acrylate, isobutyl acrylate, n-octyl acrylate,
Acrylic ester derivatives such as 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate, dimethylaminoethyl acrylate, diethylaminoethyl acrylate, and the like can be mentioned as materials for forming the organic fine particles. These can be used alone or in combination.

Further, as materials for constituting the other vinyl resin fine particles, olefins such as ethylene, propylene and isobutylene, halogen-based vinyls such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride,
Vinyl propionate / vinyl acetate / vinyl benzoate vinyl esters, vinyl methyl ether / vinyl ethyl ether vinyl ethers, vinyl methyl ketone / vinyl ethyl ketone / vinyl hexyl ketone vinyl ketones, N-vinyl carbazole / N -N-vinyl compounds such as vinylindole / N-vinylpyrrolidone, vinyl compounds such as vinylnaphthalene / vinylpyridine, acrylonitrile / methacrylonitrile / acrylamide / N-butylacrylamide / N, N-dibutylacrylamide / methacrylamide / N There are acrylic acid or methacrylic acid derivatives such as -butyl methacrylamide and N-octadecyl acrylamide. These vinyl monomers can be used alone or in combination.

Further, the resin fine particles need to be stable even when the developer is used for a long period of time.
For this purpose, it is preferable to cross-link the resin machine fine particles themselves with various cross-linking agents and use them as those having high hardness. Examples of the cross-linking agent include divinylbenzene / ethylene glycol diacrylate / diethylene glycol diacrylate / triethylene glycol diacrylate / ethylene glycol glycol dimethacrylate / diethylene glycol dimethacrylate / triethylene glycol dimethacrylate. The amount of the crosslinking agent used is appropriately adjusted depending on the required degree of crosslinking, and is preferably used in an amount of 0.1 to 5% by weight based on the vinyl monomer. If the amount of the cross-linking agent is excessive, the hardness increases, but the brittleness becomes brittle, and on the contrary, there is a problem that the durability decreases. If the amount of the cross-linking agent is too small, the effect of the cross-linking agent cannot be exerted.

The resin fine particles can be produced by an emulsion polymerization method or a suspension polymerization method. Emulsion polymerization is a method of adding the above monomer to water containing a surfactant and emulsifying it, and then polymerizing it, and as the surfactant, sodium dodecylbenzene sulfonate, polyvinyl alcohol, ethylene oxide adduct, and higher Any substance used as a surfactant such as alcohol sodium sulfate can be used and is not particularly limited. Furthermore, the use of a reactive emulsifier, a hydrophilic monomer, for example, polymerization with a persulfate initiator such as vinyl acetate or methyl acrylate, a method of copolymerizing a water-soluble monomer, a water-soluble resin or A so-called non-emulsion polymerization method such as a method using an oligomer, a method using a decomposable emulsifier, a method using a cross-linking emulsifier is also suitable. Examples of reactive emulsifiers include sulfonates of acrylic acid amides and salts of maleic acid derivatives. The emulsion-free polymerization method has no influence of the residual emulsifier and is suitable when organic fine particles are used alone.

Polymerization initiators necessary for synthesizing the resin fine particles include peroxides such as benzoyl peroxide and lauryl peroxide, and azo polymerization initiators such as azobisisobutyronitrile and azobisisovaleronitrile. Agent. The addition amount of these is preferably 0.1 to 2% by weight with respect to the monomer. If the amount is less than this amount, the polymerization reaction is insufficient and the problem of residual monomer itself occurs. In addition, when the amount is excessive, a decomposition product of the polymerization initiator remains and affects the chargeability, and furthermore, the polymerization reaction is too fast, resulting in a problem that the molecular weight becomes small. Further, in the emulsion polymerization method or the like, potassium persulfate, sodium thiosulfate or the like can be used as a polymerization initiator.

The inorganic fine particles and the resin fine particles may be used in combination.

The fine particles are preferably added in an amount of about 0.1 to 5.0% by weight based on the toner. If the addition amount is too small, the effect of improving the transferability, which is the object of the present invention, does not occur, and if it is too large, problems such as scratches on the photoconductor due to release of the added fine particles and poor conveyance of the developer occur.

In the present invention, it is also preferable to add inorganic fine particles having a so-called small particle size in addition to the fine particles constituting the present invention. In this case, the inorganic fine particles used are not particularly limited, and the inorganic fine particles described above can be used. Further, it is preferable to use after being subjected to a hydrophobizing treatment, and in this case also, it is preferable to treat with the above-mentioned hydrophobizing agent. In this case, as the inorganic fine particles having a small particle diameter, those having a number average primary particle diameter of 5 to 50 nm are preferably used. When the particle size is large, the desired effect of improving the fluidity is not exhibited, while when it is small, the adhesiveness to the toner is high, and therefore the effect of improving the fluidity is not exhibited.

In the present invention, as a specific device for immobilizing the fine particles on the surface of the colored particles, a vibro-mill, a V-type mixer, a rocking mixer, a Loedige mixer, a Nauta mixer, a W cone mixer or the like is used. be able to. Among them, the vibro-mill uses the vibration force generated by the rotating bell bell method to a mixing container filled with colored particles, fine particles and a mixed medium, and uses the convective mixing due to the movement of the mixed medium, the compression action and the shear action due to the collision of the mixed medium. The microscopically uniform immobilization can be performed by the immobilization described above, the mixing utilizing the frictional action due to the collision between the mixed medium and the container wall, and the like. Further, it can be preferably used from the viewpoint of ease of heating from the outside and continuous treatment.

FIG. 1 is an explanatory view showing the details of the by-blow mill according to the present invention. 5 is the Vibro mill main body, 6,
Reference numeral 7 is an eccentric vibration source, 8 is a spring, 9 is a flexible shaft coupling, and 10 is a motor. In this vibrating mill, vibrating by eccentric vibration sources 6 and 7,
The immobilization process is performed by causing the mixed medium 4 and the colored particles and the fine particles in the main body to undergo relatively small impact action, shear action, and friction action. Since the mixed medium 4 repeatedly collides while moving in the entire mill body 5, fine particles are uniformly dispersed and fixed to the colored particles in a microscopic manner.
Further, as a method of controlling the temperature, it is preferable to adjust the temperature to the required temperature by using hot water or the like from the outside. At this time, the method of measuring the temperature is to measure the temperature of a portion where the toner flows while the toner is mixed. Furthermore, it is preferable that cold water be circulated after the fixing treatment to carry out a cooling and crushing step.

The present invention is characterized in that the fixing step is carried out after the colored particles and the fine particles are pre-mixed under the specific conditions as described above, and the pre-mixing step is performed under the condition that the mechanical impact force is large. And when the glass transition temperature of the resin of the colored particles is Tg, the premixing temperature ≦
Since the mixture is stirred and mixed in the material temperature range of Tg-30 ° C., the mechanochemical effect and the crushing effect of the fine particles into the primary particles are further imparted to the electrostatic frictional force between the colored particles and the fine particles. It is possible to obtain a mixture in which fine particles are densely dispersed on the surface of the colored particles and are evenly attached in a short time.

When the stirring peripheral velocity at which the mechanical impact force during premixing is small is less than 30 m / sec,
The crushing effect of the fine particles into the primary particles is insufficient, and the particles cannot be evenly attached to the surface of the colored particles, causing so-called release of the fine particles. In addition, the temperature during premixing is Tg-
If the temperature is higher than 30 ° C., the surface of the colored particles begins to soften before the fine particles are evenly attached to the surface of the colored particles, causing aggregation or fusion of the colored particles.

On the other hand, in the fixing step, the mechanical impact force is slightly lower than that in the premixing step, and the material temperature is Tg.
Since the treatment is carried out by increasing the temperature to −20 ° C. ≦ fixing temperature ≦ Tg + 20 ° C., it is possible to easily and softly fix the fine particles suitably attached to the surface of the colored particles without releasing them.

On the other hand, when the stirring impeller peripheral speed is set to 40 m / sec or more and the mechanical impact force is increased at the temperature of Tg-20 ° C. or less, the immobilization rate Fd at this time becomes 10% or more. However, it becomes a hard immobilization state, and the desired effect cannot be obtained.

Further, by holding at the fixing temperature in the range of 1 min ≦ holding time ≦ 60 min, the fine particles can be uniformly fixed on the surface of the colored particles. Furthermore,
Since the product temperature is adjusted within the speed range of 1.0 ° C / min ≤ temperature rise and temperature decrease ≤ 5.0 ° C / min, there is no variation in product temperature or blocking in the tank, and the inside of the tank is always uniform. It is possible to perform immobilization treatment in a simple state, and a very uniform immobilization state can be achieved.

When the temperature is raised at a high rate of 5.0 ° C./min or more, the temperature distribution in the tank varies, and there are a very high temperature portion and a portion where the temperature hardly changes, and coloring occurs. The immobilized state on the particle surface also becomes non-uniform. Further, when the temperature is raised at a slow rate of 1.0 ° C./min or less, the stirring time becomes very long, the fine particles adhering to the surface of the colored particles are gradually released, and the flow state in the tank deteriorates. May cause blocking, etc. From this, in order to proceed the immobilization in a uniform state, it is preferable that the temperature rising rate is set to an appropriate rate and the holding time is set to some extent. A very uniform immobilization state is achieved by advancing the immobilization in a state where the entire inside of the tank has a uniform and constant temperature.

In the present invention, when all of the above conditions are satisfied, stable chargeability and high and stable transferability are maintained for a long period of time, and excellent developer performance is exhibited. If any one of these conditions is out of the range, the above problems occur, and a developer having desired performance cannot be obtained.

As a temperature control method, it is desirable to adjust the temperature to the required temperature by using hot water or the like from the outside. At this time, the method of measuring the temperature is to measure the temperature of the portion where the toner flows while the toner is being stirred and mixed. Furthermore, it is preferable to carry out a cooling step by circulating cold water after the fixing treatment.

Further, in the present invention, since all the treatments are carried out by the same stirring and mixing apparatus, it is possible to immobilize two or more kinds of fine particles simultaneously or separately. Further, a fluidity improver or the like may be added and mixed after the immobilization treatment.

A method of forming an image on the photoreceptor may be a method of forming an image by contact development, and in the case of forming a color image, an image is repeatedly formed on the photoreceptor without contact with a developer. Alternatively, a method of forming a full-color image may be used, or a method of forming one color on the photoconductor in a contact or non-contact state, sequentially transferring from the photoconductor to an intermediate transfer body, and forming a full-color image on the intermediate transfer body may be used. .

When developing in a non-contact state, it is preferable to convey the developer by a thin layer forming method. The thin layer forming method is 20 to 500 μm in the developing area on the surface of the developer carrier.
The method of forming the developer layer of is shown. When forming this thin layer, there are a magnetic blade that uses a magnetic force and a method of pressing a developer layer restriction rod against the surface of the developer carrying member. Furthermore, there is also a method in which a urethane blade, a phosphor bronze plate or the like is brought into contact with the surface of the developer carrying member to regulate the developer layer.

As the developer carrying member, a developing device in which a magnet is built in the carrying member is used, and as the developer carrying member surface, aluminum or aluminum whose surface is oxidized or stainless steel is used. To be

The pressure regulating force of the pressure regulating member is 1 to 1
5 gf / mm is preferred. When the pressing force is small, the regulation force is insufficient and the conveyance becomes unstable. On the other hand, when the pressing force is large, the stress on the developer increases, and the durability of the developer decreases. The preferred range is 3
10 to 10 gf / mm.

A gap (Ds) between the developer bearing member and the photosensitive member surface.
d) needs to be larger than the developer layer, and the gap is preferably wider than the developer layer by 10 μm or more. A particularly preferable range is 15 to 200 μm. Further, it is preferable to apply an AC bias as an alternating electric field in addition to a DC component as a developing bias. 100 as an alternating electric field
0 to 3000 Hz, the peak to peak (V
The absolute value of pp) is preferably 500 to 2000V. If it exceeds this range, the effect of pulling back the weakly charged toner, which is the effect of the alternating electric field, is not exhibited, and if it is smaller than this range, the action of the alternating electric field is not exhibited.

The size of the developer carrying member is 10 in diameter.
Those having a size of ４０40 mm are preferred. If the diameter is small, the mixing of the developer is insufficient, and it becomes difficult to ensure sufficient mixing to impart charge to the toner, and if the diameter is large, the centrifugal force against the developer becomes large, Cause the problem of splattering.

[0054]

In the present invention, when the colored particles and the fine particles are mixed in the presence of a substantially spherical mixed medium and the glass transition temperature (° C.) of the colored particles at the time of mixing is Tg, Tg
Since the treatment is carried out in the temperature range of -20 ° C ≤ immobilization treatment temperature ≤ Tg + 20 ° C, the effect of dispersing the medium can achieve uniform immobilization and dispersion of the added fine particles, and no fusion or aggregation of the colored particles occurs. Therefore, the sieving step can be omitted. Moreover, it is possible to increase the filling rate of the mixing medium having a substantially spherical shape into the mixing container, and it is possible to bring colored particles and fine particles into contact with the mixing medium with high probability, and to mix and immobilize in a short time. Is achieved. Further, the impact force given from the medium is smaller than that of the blade type fixing device, and the mixing strength can be freely adjusted by appropriately selecting the type of medium, and the desired soft fixing can be achieved. Is fully achieved.

In another embodiment of the present invention, in the premixing step of the colored particles and the fine particles, when the glass transition temperature (° C.) of the resin of the colored particles is Tg under the condition that the mechanical impact force is large. Pre-mixing temperature ≤ Tg-30
Since the mixture is stirred and mixed in the material temperature range of ℃, a mechanochemical effect is further added to the electrostatic frictional force between the colored particles and the fine particles, and a crushing effect of the fine particles into primary particles is added. It is possible to obtain a mixture in which the fine particles are densely dispersed on the surface and are uniformly attached in a short time. In the mixture in such a state, white particles derived from fine particles cannot be observed, which is clearly different from the conventional mixture.

In the immobilization step, the mechanical impact force is lower than in the premixing step, and the material temperature is Tg.
Since the treatment is carried out by increasing the temperature to −20 ° C. ≦ fixing temperature ≦ Tg + 20 ° C., it is possible to easily and softly fix the fine particles suitably attached to the surface of the colored particles without releasing them. Further, at the fixing temperature, 1 min ≦ holding time ≦ 6
By holding in the range of 0 min, the fine particles can be fixed uniformly on the surface of the colored particles. Furthermore, 1.0
Since the product temperature is adjusted within the speed range of ℃ / min ≤ temperature rise and temperature decrease ≤ 5.0 ℃ / min, the toner sieving process should be performed without variations in product temperature or blocking in the tank. Is preferable, but this can be omitted. It is possible to perform the immobilization treatment in the tank in a uniform state at all times, and to achieve a very uniform immobilization state.

[0057]

The present invention will be described in detail below with reference to examples, but the embodiments of the present invention are not limited thereto.

Example 1 [Production Example of Colored Particles] (Production Example 1 of Colored Particles) Component Weight Part Polyester Resin (Glass Transition Temperature = 57 ° C.) 100 Carbon Black 10 Polypropylene 2 The above components were kneaded, pulverized, classified and the volume was increased. Average particle size 8.5μ
m colored particles were obtained. This is designated as "black colored particle 1".

(Preparation Example 2 of Colored Particles) In Preparation Example 1 of colored particles, C.I. I. Pigment Yellow 17 was used to obtain colored particles in the same manner. This is designated as "Y colored particle 1".

(Production Example 3 of Colored Particles) In Production Example 1 of colored particles, C.I. I. Pigment Red 122 was used, and colored particles were obtained in the same manner. This is designated as "M colored particle 1".

Production Example 4 of Colored Particles In Production Example 1 of colored particles, C.I. I. Pigment Blue 15: 3 was used, and colored particles were obtained in the same manner. This is designated as "C colored particle 1".

[Production Example of Added Fine Particles] (Fine Particles 1) Dry silica (number average primary particle diameter 100 n
m) 100 g of hexamethyldisilazane was stirred in methanol for 30 minutes, filtered, dried, and then crushed to prepare.

(Fine Particles 2) Dry silica (number average primary particle diameter 15 nm) was prepared in the same manner as the fine particles 1.

(Fine Particle 3) Amorphous titania (number average primary particle diameter 150 nm) was prepared by treating with 10 g of C ₁₀ H ₂₁ Si (OCH ₃ ) _{3 in} the same manner as the fine particle 1.

(Fine Particles 4) Amorphous titania (number average primary particle diameter 20 nm) was prepared in the same manner as the fine particles 3.

(Fine Particles 5) Fine particles of methyl methacrylate (MMA) (number average primary particle diameter 50 nm) prepared by emulsion polymerization were used.

(Fine Particles 6) Methyl methacrylate (MMA) fine particles (number average primary particle diameter 1200 nm) produced by emulsion polymerization were used.

[Toner Production Example] The colored particles and the fine particles are premixed by a Mitsui Henschel mixer (FM-10B) and continuously supplied to the by-blow mill of FIG. 1 filled with a mixed medium, and hot water is circulated in the jacket. Then, the fixing process is carried out so that the temperature at the toner discharge port becomes the temperature shown below, and the diameter, the specific gravity, and the filling ratio of the medium used are as shown in "Table 1". Cooling was performed by passing the cold water through the mill once again, and the treated product was collected and collected to obtain the toner of the present invention. Further, as a comparison, an immobilization treatment was also performed on a stirring blade type device that does not use a medium. Tables 1 and 2 show the conditions and the results.

[0069]

[Table 1]

[0070]

[Table 2]

[Actual Machine Test] (Production Method of Carrier) Specific Gravity 5.0, Weight Average Particle Diameter 40 μ
The surface of the Cu—Zn ferrite particles having a saturation magnetization of 62 emu / g when an external magnetic field of m, 1000 oersted is applied, is methylmethacrylate / styrene = 6/4.
The copolymer having the composition was prepared so that the average film thickness of the coating layer was 2.0 μm.

(Developer manufacturing method) 558 g of the above carrier
And 42 g of the toner in Table 1 in which neither agglomerate nor fusion was generated, using a V-type mixer under a test environment (20 ° C .;
50% R.I. H. ) For 20 minutes to prepare four color developers of yellow (Y), magenta (M), cyan (C) and black.

<Evaluation device, conditions> Evaluation is carried out by Konica color copying machine Koni of non-contact development batch transfer system in which all the colors are superposed on the photoconductor and then collectively transferred onto transfer paper.
The ca9028 was modified and used. The conditions are as shown below. A laminated organic photoreceptor was used as the photoreceptor.

Photoconductor surface potential = -550V DC bias = -250V AC bias = Vp-p: -50 to -450V Alternating electric field frequency = 1800Hz Dsd = 300 .mu.m Pressing restriction force = 10 gf / mm Pressing restriction member = SUS416 (magnetic stainless steel) Made) /
Diameter 3 mm Developer layer thickness = 150 μm Developer carrier = 20 mm << Evaluation items, method >> N. Environmental conditions (20
C .; 50% R.C. H. ), The live-action evaluation is 10,000
Sheets were subjected to evaluation, and the initial stage and after 10,000 sheets of copying were evaluated for developability / transferability and fluidity, white streaks, drum scratches, and toner scattering within the machine. Regarding the evaluation of the transferability of the superposed colors, four color developers were developed on the photoconductor in the order of Y, M, C and black, and the transferability thereof was evaluated.

(1) Developability A patch having an original density of 1.3 2.0 cm × 5.0 cm was developed and the amount of developed toner per 1 cm ² was calculated.

(2) Transferability In the same manner as the developing property measurement, the ratio of the toner on the transfer member to the total amount of development was measured.

(3) Color toner superposition color transferability Evaluation of superposition color when toner is superposed and developed in the order of Y, M, C and black on the photoconductor and transferred to the transfer body. Was visually observed (○ (good) → △ → × (bad)).

(4) Fluidity The static bulk density of the toner was measured using a Kawakita type static bulk density measuring device. In addition, the toner replenishment property was evaluated during the actual machine test.

(5) White streaks Evaluation was made by observing the photographed image with the naked eye. This is an evaluation of image defects due to the formation of aggregates of toner and release external additive.

(6) Drum scratches Vertical stripes in the image were evaluated in the same manner as in (5). This is an evaluation of image defects due to the formation of scratches on the drum.

(7) Toner Scattering The state of contamination inside the machine after 10,000 copies was visually evaluated (◯ (good) → Δ → × (bad)).

<Evaluation Results> The above evaluation was carried out by preparing a developer from the toner shown in Table 1 in which neither aggregates nor fusion occurred. Table 3 shows the results.

[0083]

[Table 3]

It can be seen that while the characteristics within the present invention have no problem with any of the characteristics, the characteristics outside the invention have a problem with at least any of the characteristics, which is a problem in practical use.

Example 2 [Production Example of Colored Particles] (Production Example 1 of Colored Particles) Component Weight Part Polyester Resin (Glass Transition Temperature = 57 ° C.) 100 Carbon Black 10 Polypropylene 2 The above components are kneaded, pulverized, classified and the volume is increased. Average particle size 8.5μ
m colored particles were obtained. This is designated as "black colored particle 1".

(Production Example 2 of Colored Particles) In Production Example 1 of colored particles, C.I. I. Pigment Yellow 17 was used to obtain colored particles in the same manner. This is designated as "Y colored particle 1".

(Production Example 3 of Colored Particles) In Production Example 1 of colored particles, C.I. I. Pigment Red 122 was used, and colored particles were obtained in the same manner. This is designated as "M colored particle 1".

(Colored Particle Production Example 4) In the colored particle production example 1, C.I. I. Pigment Blue 15: 3 was used, and colored particles were obtained in the same manner. This is designated as "C colored particle 1".

[Production Example of Added Fine Particles] (Fine Particles 1) Dry silica (number average primary particle diameter 100 n
m) 100 g of hexamethyldisilazane was stirred in methanol for 30 minutes, filtered, dried, and then crushed to prepare.

(Fine particles 2) Fine particles of methylmethacrylate prepared by emulsion polymerization (number average primary particle diameter 50 n
m) was used.

[Toner Production Example] The colored particles and the fine particles were premixed by using a Mitsui Henschel mixer (FM-10B) under the conditions shown in Tables 4 and 5, and then warm water was circulated through the jacket so that the peripheral speed, time and The temperature rising rate was variously changed to obtain the toner of the present invention. The conditions and results are shown below. In this Example 2, no mixed medium was used.

[0092]

[Table 4]

[0093]

[Table 5]

[Manufacturing Example of Developer] (Manufacturing Method of Carrier) The same method and composition as in Example 1 were used.

(Developer Manufacturing Method) The same method as in Example 1,
It was made with the composition.

<< Evaluation of Toner and Developer >> The toner and developer prepared by the above method were evaluated for floating external additive, turbidity of free external additive, and evaluation of charge buildup of the developer. , Tested on the actual machine.

<< Evaluation of Actual Machine >> The same equipment as in Example 1 was used.

<< Evaluation Items and Method >> N.
Under environmental conditions (20 ° C .; 50% RH), the actual copying evaluation was performed on 10,000 sheets, and the charge amount, the firefly, and the black spot were evaluated at the initial stage and after copying 10,000 sheets.

(1) Floating External Additives Using a powder tester manufactured by Hosokawa Micron Co., Ltd., 60 g of the toner prepared as shown in Table 1 was used to perform a tapping test, and external additive particles which could be visually confirmed floating on the surface. The number was evaluated by counting.

(2) Turbidity Using COH-300A manufactured by Nippon Denshoku Co., Ltd., thickness 1c
Toner (0.4 mg) and water (1 ml) were placed in a cell of m, and the turbidity (diffusive transmittance / total transmittance × 100) was measured. Practically, it is desirable to be 20% or less.

(3) Rising Charge of Developer Charge The charging rise performance was evaluated by taking the ratio of 1 minute to 20 minutes after the start of mixing during the mixing described in the above-mentioned developer manufacturing method. It is preferably 0.75 or less.

Actual machine test (4) Amount of charge A durability test was conducted using an actual machine, and the amount of charge of the initial developer was set to 1
The charge amount at the end of 0000 copies was measured by the blow-off method.

(5) Firefly optical image defects due to toner aggregates were evaluated from the firefly image sample.

(6) Black spots Due to the influence of aggregates of free external additives generated on the photoreceptor,
The image defect of the black spot was evaluated.

<< Evaluation Results >> The above-mentioned evaluations were carried out by preparing a developer with each of the toners shown in Tables 4 and 5. Tables 6 and 7 show the results.

[0106]

[Table 6]

[0107]

[Table 7]

[0108]

In the present invention, when the colored particles and the fine particles are mixed in the presence of a mixed medium and the glass transition temperature (° C) of the colored particles at the time of mixing is Tg, Tg-20 ° C.
Since the treatment is carried out in a temperature range of ≤ immobilization treatment temperature ≤ Tg + 20 ° C, the effect of dispersing the medium does not cause fusion or agglomeration of the colored particles to achieve uniform immobilization and dispersion of the added fine particles. Mixing and immobilization are achieved in a short time. Further, the impact force applied from the medium is minute as compared with other types of immobilization devices, and the desired soft immobilization is achieved.

In the premixing step of the colored particles and the fine particles according to another embodiment of the present invention, when the glass transition temperature (° C.) of the resin of the colored particles is Tg under the condition of large mechanical impact force. , Pre-mixing temperature ≦ Tg -30 ° C. with stirring in the range of material temperature. As a result, the fine particles of the external additive are densely dispersed on the surface of the colored particles, and a mixture in a state of uniformly adhering can be obtained in a short time. No spots were found.

In the immobilization step, the mechanical impact force is lower than that in the premixing step, and the material temperature is Tg.
Since the treatment is performed by increasing the temperature to −20 ° C. ≦ fixing temperature ≦ Tg + 20 ° C., it is possible to easily and softly without releasing the fine particles suitably attached to the surface of the colored particles, even without using a mixed medium. It can be fixed. No agglomerates or fused deposits of colored particles were observed, and no image defects such as fireflies were observed. Further, at the fixing temperature, 1 min ≦
Hold in the range of hold time ≤ 60 min, and
Since the product temperature is adjusted within the speed range of 1.0 ° C / min ≤ temperature rise and temperature decrease ≤ 5.0 ° C / min, a very uniform immobilization state can be achieved, and the charge amount can be stabilized over a long period of time. It is possible to obtain a developer having an excellent charging rise.

As a result, it is possible to carry out a multi-development and batch transfer process for the purpose of maintaining stable chargeability and high and stable transferability for a long period of time, and also miniaturizing the apparatus and preventing color misregistration. In order to achieve stable image density and stable transfer characteristics over a long period of time, an electrostatic charge image developing toner in which an external additive is softly fixed uniformly on the surface of colored resin particles is obtained. Was given.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram for explaining a by-blow mill according to the present invention.

[Explanation of symbols]

 4 Mixed medium 5 Mill body 6 Eccentric vibration source 7 Eccentric vibration source 8 Spring 9 Flexible shaft coupling 10 Motor

Claims (14)

[Claims] 1. A method for producing a toner for developing an electrostatic charge image, comprising the steps of adding fine particles to colored particles comprising at least a resin and a colorant, the fine particles being fixed on the surface of the colored particles. The treatment mixes the colored particles and the fine particles in the presence of a substantially spherical mixed medium, and the temperature of the colored particles at the time of mixing is the glass transition temperature (° C) of the resin Tg.
The method for producing an electrostatic charge image developing toner is characterized in that the mixed medium is removed after being treated in the temperature range shown below. Tg-20 ° C ≤ immobilization treatment temperature ≤ Tg + 20 ° C 2. The volume average particle diameter of the mixed medium is 0.1 to 10.
It is 10 mm, The manufacturing method of the toner for electrostatic image development of Claim 1 characterized by the above-mentioned. 3. The method for producing an electrostatic charge image developing toner according to claim 1, wherein the specific gravity of the mixed medium is 2.0 to 4.0. 4. The volume ratio of the mixed medium and the colored particles to be treated is as shown below.
4. The method for producing the electrostatic charge image developing toner according to 2 or 3. Mixed medium: colored particles = 1: 2 to 2: 1 5. A method for producing a toner, which comprises adding fine particles to colored particles comprising at least a resin and a coloring agent, wherein the fine particles have a volume average particle diameter of 50 to 1000 nm and the surface of the colored particles is 10 The method for producing an electrostatic charge image developing toner according to any one of claims 1 to 4, wherein the toner is fixed at a fixing rate of 90% to 90%. 6. The method of producing an electrostatic charge image developing toner according to claim 1, wherein the fine particles are inorganic fine particles or resin fine particles. 7. A toner obtained by adding fine particles to colored particles comprising at least a resin and a colorant, wherein the fine particles are fixed on the surface of the colored particles after a premixing step of the colored particles and the fine particles. The fixing step is performed, and when the temperature of the colored particles during the pre-mixing is Tg which is the glass transition temperature (° C.) of the resin, the pre-mixing is performed within the temperature range shown below. Toner for developing electrostatic images. Premix temperature (° C) ≤ Tg-30 ° C 8. In a method for producing a toner for developing an electrostatic charge image, which comprises a fixing step after at least a premixing step of colored particles and fine particles, the temperature of the colored particles at the fixing step is the glass transition temperature of the resin ( (C) as Tg, the toner is fixed at a fixing rate of 10 to 90% by treating in the temperature range shown below, and a method for producing an electrostatic image developing toner. Tg-20 ° C ≤ immobilization treatment temperature ≤ Tg + 20 ° C 9. The method for producing an electrostatic charge image developing toner according to claim 8, wherein in the method for producing an electrostatic charge image developing toner, the toner is held for at least the time shown below. 1 min ≦ holding time ≦ 60 min 10. The method for producing a toner for developing an electrostatic charge image according to claim 8 or 9, wherein the temperature rising rate and the temperature falling rate in the fixing step are processed in the following rate ranges. A method for producing the electrostatic charge image developing toner as described above. 1.0 ° C./min≦temperature rise and temperature decrease rate ≦ 5.0 ° C./mi
n 11. The method for producing a toner for developing an electrostatic charge image according to claim 8, 9 or 10, wherein the peripheral speed of the agitating blade of the mixer is processed in the following speed range. A method for producing the electrostatic charge image developing toner as described above. Premixing speed ≧ 30 m / sec 10 m / sec ≦ fixing processing speed ≦ 40 m / sec 12. The toner for developing an electrostatic charge image according to claim 8, further comprising a sieving process after the fixing process in the method for producing the toner for developing an electrostatic charge image. Manufacturing method. 13. A method for producing a toner, which comprises adding fine particles to colored particles comprising at least a resin and a colorant, wherein the fine particles have a volume average particle size of 50 to 1000 nm, and the surface of the colored fine particles is 10 8. The method according to claim 8, wherein the fixation is performed at a fixation rate of 90%.
3. The method for producing the electrostatic charge image developing toner according to any one of 2 above. 14. The method for producing an electrostatic charge image developing toner according to claim 8, wherein the fine particles are inorganic fine particles or resin fine particles.