JP2604626B2 - Method for producing photoconductive toner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to electrophotography, and more particularly to a method for producing a toner having photoconductivity by itself.

[Prior Art] Conventionally, the configuration of a photoconductive toner includes a configuration in which a photoconductive substance is dispersed in a resin, a configuration in which the surface of a resin core is covered with a photoconductive substance, and the like. Examples of the method for producing the photoconductive toner having such a configuration include a melt-kneading method and a microcapsule method.

Melt kneading method, as seen in JP-A-54-86335, a photoconductive substance and a material mainly comprising an insulating resin, kneading rolls, kneaders, etc., after melt-kneading, pulverized, classified,
This is a method for producing a photoconductive toner. This method has 50
When melt-kneading a photoconductive substance of up to 90% by weight with an insulating resin, sufficient melt-kneading is difficult to perform, so that the photoconductive properties of the resulting toner tend to be non-uniform due to the particles. Further, since the kneading temperature is usually about 200 to 300 ° C., a photoconductive substance which does not decompose or change at this temperature must be used, and the photoconductive substance which can be used is limited.
Furthermore, the composition of the photoconductive toner to be manufactured is also limited to a photoconductive substance dispersed in a resin, and the photoconductive property is received by the toner coating layer, and the fixing property is provided to the core. It is difficult to provide a function separation structure.

The microencapsulation method is disclosed in JP-A-56-30138,
As disclosed in JP-A-56-30140, a method in which a photoconductor dispersion is sprayed on a fluidized bed of an insulating core,
-82417, a core material is dispersed in a liquid in which a photoconductor is dispersed as shown in JP-A-60-133459, and the mixed dispersion is dried to form a photoconductive material on the surface of the core material. It covers the body. This method is not preferable because, when an organic solvent is used as a dispersion medium, there is a problem such as pollution in production, and when an aqueous medium is used, there is a problem that core material particles tend to coagulate and solidify in a drying step.

Japanese Patent Application Laid-Open No. 60-258558 proposes a method in which photoconductive particles are mixed with each other, then introduced into a heat treatment chamber, and both particles are adhered to each other to form a sphere. Such a method requires a large heat treatment chamber, a hot air supply device, a cooling air supply device, and an exhaust air supply device, which increases the size of the entire device and prevents generation of coarse particles due to thermal fusion between toner particles. Not preferred.

Further, as a method of coating the surface of the toner particles, there is known a method of using a mixer such as Henschel or the like to batch-fix particles such as an external additive on the toner surface by rotating blades in a fixed container using a mixer. Such a method is suitable for coating with a small amount of fine particles and a loose state with respect to the entire amount of toner.
It is difficult to coat and fix thick and uniform with fine particles,
Further, if the rotation time and the number of rotations of the rotating blades are increased in order to achieve such an object, toner fusion and aggregation of toner particles are undesirably caused.

[Problems to be Solved by the Invention] An object of the present invention is to provide a method for producing a photoconductive toner that overcomes the above-mentioned problems.

The object of the present invention is to have good photoconductivity, semiconductivity,
JP-A-54-86335 and JP-A-62-249169 provide a method for producing a photoconductive toner suitable for an image forming method using a photoconductive toner. .

Further, an object of the present invention is to provide a photoconductive toner that uniformly and firmly coats the photoconductive resin particles on the surface of the resin particles.

[Means and Actions for Solving the Problems] The object of the present invention is to provide a resin particle A and a photoconductive resin particle B having a particle size ratio of 0.2 or less to the resin particle A.
Has an impact part having a shortest gap of 0.5 to 5 mm formed from a rotating piece and a fixed piece under the condition of an ambient temperature of 10 to 90 ° C. or a shortest gap of 0.5 to 5 mm formed from two kinds of rotating pieces. A method for producing a photoconductive toner, wherein the photoconductive resin particles B are immobilized on the surface of the resin particles A by a mechanical shock at the impact portion. .

The toner of the present invention fixes the photoconductive resin particles B in a powdery state by mechanical impact. Therefore, the toner of the present invention is used in the subsequent steps, for example, when stirring or developing at the time of external addition of silica or the like. It does not release due to agitation, rubbing, etc. of the toner and acts integrally with the toner. Further, the amount of the photoconductive resin particles on the surface of the toner is controlled and uniformly present. Furthermore, the toner obtained by such a method has a small amount of free photoconductive resin particles and can provide good developing characteristics without causing carrier contamination and sleeve contamination.

The photoconductive resin particles B and the resin particles A preferably have a value of (average particle diameter of particles B / average particle diameter of particles A) of 0.2 or less. When the particle size ratio is 0.2 or more, the resin particles A
It is difficult to uniformly fix the particles B on the surface of the particles.

The coverage of the particles B (the ratio at which the particles A are surrounded by the particles B) is represented by the following equation.

[Wherein, W ₁ represents the weight of particle A, W ₂ represents the weight of particle B, R ₁ represents the average particle size of particle A, R ₂ represents the average particle size of particle B, and M ₁ Indicates the true density of the particle A, and M ₂ indicates the true density of the particle B. In the above formula, when the coverage exceeds 100%, this is taken as 100%.

The resin particles A have a coverage of 10 to
Preferably, the coating is 100%, more preferably 51-100%.

If the coverage is less than 10%, the photoconductivity is insufficient,
The tendency that it is difficult to obtain an image with high image density increases.

The particle size distribution is measured by the following measurement method. The number average distribution and the volume average distribution are output by using a Coulter Counter TA-II type (manufactured by Coulter) or El Zone Particle Counter 80XY-2 (manufactured by United States Particle Data) as a measuring device. As the electrolytic solution, a 1 to 4% NaCl aqueous solution is used.

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

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 above-mentioned Coulter counter TA-II type or Elzone particle counter 80XY-2 was used. ~ 40μ
Is measured to obtain a volume average distribution and a number average distribution.

Although there is no particular limitation on the photoconductive substance that can be used in the present invention, examples of the organic photoconductive substance include vinylcarbazoles, indoles, oxazoles, imidazoles, and the like, and inorganic photoconductive substances. Is selenium,
Cadmium sulfide, and the like. In order to obtain photoconductive resin particles, these photoconductive substances are added to the resin in an amount of 0.
The content may be 5 to 90% by weight, preferably 2 to 70% by weight.

In order to make these photoconductive substances into photoconductive resin particles B, (i) a photoconductive substance powder is dispersed or dissolved in a resin solution, and the mixed solution is spray-dried, Method of obtaining photoconductive resin particles by removing solvent (ii) Method of obtaining photoconductive resin particles by suspending or emulsion polymerizing photoconductive substance powder together with resin monomer (iii) Photoconductive substance , Melt kneading with resin,
A method of obtaining photoconductive resin particles by crushing and classifying.

and so on.

In order to make these photoconductive substances into photoconductive resin particles B, a photoconductive substance powder is dispersed or dissolved in a resin solution,
A method for obtaining photoconductive resin particles by removing the solvent by spray-drying the mixed solution, and a method for obtaining a photoconductive resin particle by suspending or emulsion polymerizing a photoconductive substance powder together with a resin monomer. Melting and kneading the photoconductive substance together with the resin, pulverizing,
A method of obtaining photoconductive resin particles by classification.

As the resin used for the photoconductive resin particles B, those shown below are preferably used, but not limited thereto.

The particle diameter of the photoconductive resin particles B is 0.
Those having a particle size distribution of 1 to 5μ, particularly 0.5 to 3μ are preferably used, and those having a uniform particle size distribution (sharp) are preferable for uniform coating.
Rv ± 2μ at 60% or more by volume particle size distribution, more preferably 70%
% Or more of the resin particles B is preferable.

As the resin used for the resin particles A and the photoconductive resin particles B, a binder material for toner can be used.
Polystyrene and its homopolymers: styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-isobrene copolymer, styrene -Styrene-based copolymers such as acrylonitrile-indene copolymers: Examples include acrylic resins, methacrylic resins, vinyl-based resins such as polyethylene, silicone resins, polyester resins, furan resins, epoxy resins, and waxes. Preferred binders include crosslinked styrenic copolymers or polyesters. Examples of the comonomer of the styrene-based copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate,
Has a double bond such as octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. Monocarboxylic acid or a substituted product thereof: for example, dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate and the like, and a substituted product thereof. Compounds having a polymerizable double bond described above are used, for example, divinylbenzene, aromatic divinyl compounds such as divinylnaphthalene, for example, ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,
Carboxylic acid ester divinylaniline having two double bonds such as 3-butanediol dimethacrylate,
Divinyl compounds such as divinyl ether, divinyl sulfide and divinyl sulfone and compounds having three or more vinyl groups are used alone or as a mixture.

Such a resin has a Tg of 50 ° C. or higher, preferably 55 ° C. or higher, which is preferable for so-called blocking property for long-term storage.

Polymerizable monomers applicable to form polymer particles as resin particles are monomers having a CH ₂ ＣC <group as a reactive group, and include styrene, o-methylstyrene, m-methylstyrene, and 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-methylene resin group monocarboxylic acid esters such as isobutyl acrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate Methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, acrylic Acrylic esters such as phenyl acid; and monomers having a reactive double bond such as a vinyl group such as acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile, and acrylamide. These may be used alone or in combination of two or more. If necessary,
A crosslinking agent may be used. Examples of the crosslinking agent include divinylbenzene, divinylnaphthalene, diethylene glycol dimethacrylate, and ethylene glycol dimethacrylate. The amount of the crosslinking agent added is usually 10 polymerizable monomers.
0.1 to 5 parts by weight is used for 0 part by weight. Among the above-mentioned monomers, styrene, styrene having a substituent such as an alkyl group, or polymer particles produced from a mixed monomer of styrene and another monomer, in consideration of developability and durability Is preferred.

Further, a generally known charge control agent may be used in combination as needed.

The resin particles A are obtained, for example, as follows. As the resin particles A by the pulverization method, a mixture comprising at least a binder resin and, if necessary, a colorant, a charge control agent, and a release agent is melt-kneaded, and after cooling, pulverized by a generally known pulverizer. If this is the case, a material having a uniform particle size distribution after classification is used. The volume average particle size of the resin particles A preferable as the toner is 2 to 20 μm.

In the present invention, in particular, resin particles A having a uniform (sharp) particle size distribution are preferable for uniform coating. When the volume average particle size of the resin particles A is Rv, the volume particle size distribution becomes Rv ± 3 μm. It is preferable that the resin particles A contain 50% or more, more preferably 60% or more.

Next, the coloring agent added to the resin particles A will be described. To produce a magnetic toner, magnetic particles are added. In this case, the magnetic particles also serve as a colorant. As the magnetic particles that can be used in the present invention, a substance that is magnetized when placed in a magnetic field is used, for example, iron, cobalt, powder of a ferromagnetic metal such as nickel or magnetite, hematite, an alloy or compound such as ferrite. Powder. Magnetic particles having a particle size of 0.1 to 1 μm, preferably 0.1 to 0.5 μm 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 toner.
Is good. Further, these magnetic fine particles may be treated with a treating agent such as a silane coupling agent or a titanium coupling agent, or a suitable reactive resin. In this case, although it depends on the surface area of the magnetic fine particles and the density of the hydroxyl groups existing on the surface, a sufficiently preferable dispersibility can be obtained with a treatment amount of 5% by weight or less (preferably 0.1 to 3% by weight).

Further, as the coloring agent, conventionally known dyes, pigments, carbon black, and pigments such as grafted carbon black in which the surface of carbon black is coated with a resin can be used. When a colorant is added, it is preferably contained in an amount of 0.5 to 30% by weight based on the binder resin.

The colorant is usually added internally to the resin particles A, but may be added or externally added to the resin particles B as needed.

When the photoconductive toner is used for one-shot color as disclosed in JP-A-52-60624,
A sublimable dye is used as a coloring agent.

The resin particles A obtained by the polymerization method are obtained, for example, by the following method, but are not limited thereto. A polymerizable monomer (monomer), colorant, polymerization initiator and, if necessary, a cross-linking agent, a charge control agent, a polar polymer, and a monomer system obtained by uniformly dissolving or dispersing other additives are used as a suspension stabilizer. It is poured into the contained aqueous phase (that is, continuous phase), and granulated and polymerized with stirring. Then remove the suspension stabilizer,
It is obtained by separate drying.

It is particularly preferable to obtain the resin particles A by a suspension polymerization method described later because the particle size distribution is sharp.

Further, a preferable polymerized toner can be obtained by adding a polar polymer having a polar group, a polar copolymer or a cyclized rubber as an additive during polymerization of the monomer to polymerize the polymerizable monomer. The polar polymer, polar copolymer or cyclized rubber is 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 the content is 0.5% by weight or less, it is difficult to obtain a sufficient pseudocapsule structure, and if the content is 50% by weight or more, the amount of the polymerizable monomer becomes insufficient, and the characteristics of the polymerized toner tend to deteriorate. Polar polymer,
It is preferable that the polymerizable monomer composition to which the polar copolymer or the cyclized rubber is added is suspended in an aqueous phase of an aqueous medium in which the polar polymer and a reversely charged dispersant are dispersed and polymerized. . That is, the cationic or anionic polymer, the cationic or anionic copolymer or the anionic cyclized rubber contained in the polymerizable monomer composition is a reversely charged anion dispersed in an aqueous medium. The electrostatic or cationic dispersant attracts electrostatically on the surface of the toner particles, and the dispersant covers the surface of the particles to prevent coalescence of the particles, stabilize, add the polar polymer, polar copolymer added Because the coalesced or cyclized rubber collects on the surface layer of the toner particles,
It becomes a kind of shell, and the obtained particles become pseudo capsules. And the relatively high molecular weight polar polymer, polar copolymer or cyclized rubber collected in the surface layer of the particles contains a large amount of the low softening point compound inside the toner particles, so that the polymer particles of the present invention have a blocking property, Provides excellent developability and abrasion resistance. The polar polymer (including the polar copolymer and the cyclized rubber) and the reverse charge dispersant which can be used in the present invention are exemplified below. The polar polymer is GPC
Those having a weight average molecular weight of 5,000 to 500,000 measured in the above are preferably used because they dissolve well in the polymerizable monomer and have durability.

Examples of the cationic polymer include a polymer of a nitrogen-containing monomer such as dimethylaminoethyl methacrylate and diethylaminoethyl acrylate, a copolymer of styrene and the nitrogen-containing monomer, or a copolymer of styrene and an unsaturated carboxylic acid ester. There are copolymers with nitrogen monomers.

Examples of the anionic polymer include 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, and a polymer of an unsaturated dibasic acid. Examples of the polymer include a polymer, a polymer of an anhydride of an unsaturated dibasic acid, and a copolymer of styrene and the monomer.

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

Aerosil # 200, # 300 as anionic dispersants
(Manufactured by Nippon Aerosil Co., Ltd.).

Examples of the cationic dispersant include aluminum oxide, magnesium hydroxide, hydrophilic positively-chargeable silica fine powder such as aminoalkyl-modified colloidal silica treated with a coupling agent, and the like.

A cyclized rubber having anionic property may be used instead of the above-mentioned polar polymer or copolymer.

In order to produce the magnetic polymer resin particles A, magnetic particles are added to the monomer composition. In this case, the magnetic particles also serve as a colorant. As the magnetic particles that can be used in the present invention, a substance that is magnetized when placed in a magnetic field is used, for example, iron, cobalt, powder of a ferromagnetic metal such as nickel or magnetite, hemitite, or an alloy or a compound such as ferrite. Powder. Magnetic fine particles having a particle size of 0.05 to 5 μm, preferably 0.1 to 1 μm are used.
The content of the magnetic particles is preferably from 10 to 60% by weight, and more preferably from 20 to 50% by weight, based on the weight of the toner. Further, these magnetic fine particles may be treated with a treating agent such as a silane coupling agent or a titanium coupling agent, or a suitable reactive resin. In this case, although it depends on the surface area of the magnetic fine particles and the density of hydroxyl groups existing on the surface, it is 5% by weight or less (preferably
With a treatment amount of 0.1 to 3% by weight, sufficient dispersibility in a polymerizable monomer and a low softening point compound can be obtained, and the physical properties of the particles are not adversely affected. When the polymer particles contain a colorant, a conventionally known dye, carbon black, a pigment such as grafted carbon black in which the surface of carbon black is coated with a resin can be used as the colorant. is there. The coloring agent is contained in an amount of 0.5 to 30% by weight based on the polymer and the low softening point compound. If necessary, a charge control agent and a fluidity modifier may be added (internally added) to the toner.

In particular, in the case of polymerization method particles, since the release agent is included therein, there is no release of the release agent such as particles in the pulverization method. It is.

The suspension polymerization method uses a monomer composition obtained by uniformly dissolving and dispersing a colorant or an additive added as necessary, by 0.1%.
~ 50% by weight of a suspension stabilizer (eg, a poorly soluble inorganic dispersant)
An aqueous medium containing (for example, 5 ° C. or higher than the polymerization temperature,
(Preferably heated to a temperature of at least 10 ° C. to 30 ° C.) using a conventional stirrer, homomixer, homogenizer or the like. Preferably, the particles of the molten or softened monomer composition are of a desired toner particle size, generally
The stirring speed, time and temperature of the aqueous medium are adjusted so as to have a size of 30 μm or less (for example, a volume average particle size of 0.1 to 20 μm). Thereafter, the liquid temperature of the aqueous medium is lowered to the polymerization temperature while stirring to such an extent that the particles are prevented from settling, so that the state is substantially maintained by the action of the dispersion stabilizer.
The polymerization temperature is set at 50 ° C. or higher, preferably 55 to 80 ° C., particularly preferably 60 to 75 ° C., and the polymerization is carried out by adding a substantially water-insoluble polymerization initiator with stirring. After the reaction,
Wash the generated toner particles, remove the dispersion stabilizer, excess,
The polymerized colored particles A that can be used in the present invention can be obtained by collecting and drying by an appropriate method such as decantation or centrifugation. In the suspension polymerization method, usually 200 to 3000 parts by weight of water is used as an aqueous dispersion medium based on 100 parts by weight of a polymerizable monomer and a low softening point compound.

The binder resin of the particles A used in the present invention or the particles A,
When the fixing system is for heat fixing, the softening point measured by the following method is preferably from 90 to 150 ° C, particularly preferably from 90 to 140 ° C.

Using a flow tester CFT-500 type (manufactured by Shimadzu Corporation)
As a sample, about 1.0 to 1.5 g of a 60-mesh bath product is weighed, and this is pressurized for 1 minute at a load of 100 kg / cm ² using a former.

This pressurized sample is subjected to a flow tester measurement under the following conditions, and a temperature corresponding to a half of a stroke difference between the start and the end of the outflow is defined as a softening point.

Measurement conditions RATE TEMP 5.0D / M (℃ 1 minute) SET TEMP 50.5DEG (℃) MAX TEMP 200.0DEG INTERVAL 2.5DEG PREHEAT 300.0SEC (second) LOAD 50.0KGF (kg) DIE (DIA) 0.5MM (mm) DIE ( LENG) 1.0MM PLUNGER 1.0CM ² (cm ² ) When used as a pressure fixing toner, as resin particles A, polyethylene wax, polyethylene oxide, paraffin, fatty acid, fatty acid ester, fatty acid amide, fatty acid metal salt, higher alcohol, etc. Waxes; ethylene-
Vinyl acetate resin, cyclized rubber and the like can be used. After heating and mixing, it may be finely divided into particles in a molten state. Conventionally known various liquid microparticulation methods can be applied. That is,
A one-fluid nozzle using pressure, a two-fluid nozzle using high-pressure airflow, a disk atomizer using a rotating disk, or the like may be used. Alternatively, the particles may be heated and melted in a solvent and then cooled to form fine particles. Here, a dispersant may be used with stirring. If necessary, the dispersant is preferably washed with water, removed with an acid or an alkali. Such a granulation method is preferable because spherical particles can be obtained.

 Next, a preferred production method is described below.

This fixing method includes a pretreatment for dispersing and uniformly adhering the photoconductive resin particles B to the resin particles A, and a step of immobilizing the adhered photoconductive resin particles B by an impact force.
Consists of one.

In the pretreatment, particles B are dispersed and rubbed against particles A to adhere to particles A by electrostatic force (and Van der Waals force). Generally, a mixer with a high-speed stirring blade is used. Any device having a dispersing function can be used.

FIG. 1 shows an example of a mixer equipped with high-speed stirring blades. As a pretreatment, it is necessary that both the particles A and B are dispersed well and that the particles A are not substantially crushed.

Therefore, the processing temperature is preferably 0 to 50 ° C., the area around the blade is 5 to 50 m / sec, and the processing time is preferably 1 minute to 60 minutes. Further, when performing such a treatment, it is preferable to cool the jacket or to cool the inside of the tank by introducing cooling air since the temperature rises due to stirring.

The pretreatment device is not limited to a mixer with a high-speed stirring blade, but may be any device having a dispersing function and a mixing function and having a sufficiently long residence time. It is also possible to use with reduced impact force. In addition to the above, the particles B may be dispersed in a liquid having the particles A, dried, dried, and then fixed.

In such pretreatment, the fluidity and dispersibility of the particles B are important in uniformly attaching the particles B to the particles A.
That is, when the particle BN exhibits strong agglomeration, individual particles cannot be formed in the pretreatment step, and uniform adhesion tends to be difficult. Similarly, when the fluidity is extremely poor, it is similarly difficult to make individual particles, and similarly, uniform adhesion becomes difficult. Regarding the particles B having poor fluidity and dispersibility, the particles B are added to the particles B in advance and mixed with the particles B to improve the fluidity and dispersibility.
It is particularly preferable to use a method for uniformly attaching to the surface. As the silica fine powder used in this method, positively charged silica is used for positively charged toner, and negatively charged silica is used for negatively charged toner. The addition amount is 0.01 to 10% by weight, preferably 0.1 to 5% by weight based on the weight of the particles B.
% By weight. As such treated silica, a positively or negatively charged silane coupling agent, a hydrophobic treatment agent,
Hydrophobic silica fine powder treated with silicon oil or the like 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. or,
Hydrophobicity determined by methanol titration test is 30
Especially preferred is a ~ 80% treated silica fine powder.

The "methanol titration test" defined herein for evaluating the degree of hydrophobicity of the treated fine silica powder is performed as follows. 0.2 g of the test silica fine powder is added to 50 ml of water in a 250 ml Erlenmeyer flask. Methanol is titrated from the burette until all of the silica is wetted.
At this time, the solution in the flask is constantly stirred with a magnetic stirrer. The end point is observed by the suspension of the entire amount of the fine silica powder in the liquid, and the degree of hydrophobicity is expressed as the percentage of methanol in the liquid mixture of methanol and water at the end point.

Next, the fixing method is used. In the toner, it is not preferable that the crushed pieces of the resin particles A and the photoconductive particles B are released, or the particles B once adhered are not preferably released, and the toner particles are more reliably fixed. Is preferred.

For this purpose, it is preferable to control the impact force within a range where the resin particles A are not pulverized and the temperature control within a range where no fusion aggregation occurs. A pin mill (see FIG. 4-1) having a recycle function and having a large number of rotating pins as an example of an immobilizing device for carrying out the method, a rotating blade or a hammer (a rotating piece) and a liner (a fixed piece). A pulverizer (see FIGS. 2-1 and 3-1) which gives an impact between the two and has a recycling function is effective.

The peripheral speed of the tip of the rotary piece in the device is preferably 30 to 130 m / sec. Although the temperature varies depending on the physical properties of the resin particles A and B, the temperature is preferably 20 to 90 ° C., and more preferably 30 to 70 ° C., and the residence time at the impact portion is preferably 0.02 to 12 seconds. In the case of a pin mill, it is necessary to increase the powder concentration. In the apparatus of the type shown in FIG. 2-1 or FIG. 3-1, the powder to be processed by the centrifugal force is collected near the liner, so that the latitude of the powder concentration is wide. The shortest gap between the pin mills or between the blade or the hammer and the liner is preferably about 0.5 to 5 mm, and more preferably 1 to 3 mm provides good results.

More specifically, referring to FIG. 2-1, the powders A and B pretreated by the method described above are introduced from the inlet 24, pass through the inlet chamber 20, and rotate along the rotating dispersion blade 14. After passing through the impact portion 19 between the blade 15 and the liner 18, passing through the exit chamber 21, passing through the return path 22 and the blower 25, the circuit circulates again. After the fixing process is completed, the product is taken out from the product take-out port 23.

Here, the powder composed of the particles A and the particles B is subjected to an impact between the blade 15 and the liner 18 at the impact portion 19, and the mechanical energy and the thermal energy obtained by converting a part of the mechanical energy into heat are used as the particles A. And a part of the particles B are melted or softened, and the immobilization treatment is performed. Here, if necessary, flow cooling water through the jacket 26,
It is preferable 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 29 of the fixing device and the rotating rotor 31.
The shortest gap of 31 is the circumference 51 obtained by connecting the tip of the protrusion to the inner periphery with the liner 29 and the locus 52 of the protrusion of the rotor 31.
Means the difference between the radii of the two types of circles. The same applies when a blade or a hammer is used instead of the rotor 31.

FIG. 4-2 is a schematic view of a pin mill type fixing device when the pins are filled from the front of the device, and a gap 55 between the fixing pin 39 and the rotating pin 54 is the shortest gap. Incidentally, 15 indicates the maximum gap, and 56 indicates the locus of the rotating pin 54.

EXAMPLES Hereinafter, the present invention will be described in detail based on examples.

The above components were mixed by an attritor at a temperature of 60 ° C. for 4 hours to prepare a monomer composition. In the obtained monomer composition
2,2'-azobis- (2,4-dimethylvaleronitrile) 10
Parts by weight and 1 part by weight of 2,2'-azobisisobutyronitrile were added, and the mixture was treated with 100 parts by weight of amino-modified silica (Aerosil # 200, 5 parts by weight of aminopropyltriethoxysilane). Thing) 10 parts by weight and 0.1N
Ion-exchanged water containing 15 parts by weight of hydrochloric acid and heated to 60 ° C
The mixture was charged into 1200 parts by weight of an aqueous medium with stirring by a TK homomixer, and stirred for 25 minutes at 10,000 rpm for dispersion granulation.

Further, the stirring was changed to paddle blade stirring, followed by stirring at 60 ° C. for 10 hours to complete the polymerization. Thereafter, the mixture was cooled, washed with a sodium hydroxide solution to remove the amino-modified silica from the solvent, washed with water, dehydrated, dried and classified to obtain resin particles A having a volume average diameter of 9.0 μm. The softening degree was 110 ° C.

Also, in the volume particle size distribution, the particle size within the range of 9.0 ± 3μ,
There were 72% by volume of the particles in total.

Particle B containing a photoconductive substance was prepared as described below.

After the above composition liquid was prepared and spray-dried, the resulting dried particles were collected and classified to obtain particles having a volume average particle diameter of 1 μm. 3 μ or more is a volume particle size distribution of 5
% Or less.

1,000 parts by weight of the particles A were treated with 430 parts by weight of the particles B at 30 m / sec for 8 minutes using the apparatus shown in FIG.

Then, using the apparatus shown in FIG.
After processing for 9 minutes at sec, the inside temperature was 50 ° C. and the coverage was 97%.

Observation with an electron microscope showed that the particles B were firmly fused and fixed to the particles A.

Next, a photoreceptor having a transparent substrate was prepared as described below.

Using a transparent glass plate as a transparent substrate, a transparent conductive layer 60 made of tin oxide is formed on the glass plate, and the following composition dispersion is applied thereon with a doctor blade,
It was air-dried to prepare a photoreceptor having a charge generation layer 61 having a thickness of about 11 μm.

Next, as shown in FIG. 5-1, the photoconductive toner obtained in Example 1 was placed on the photosensitive plate 61 manufactured as described above.
Spray 62 evenly. Charger 63 is placed on the scattered toner 62
To perform negative () corona charging (5-2).
Figure). Next, using the white light 64, exposure corresponding to the image 65 is performed from the back surface of the transparent substrate 60 (FIG. 5-3). The charge generation layer 61 generates electrons and holes by the light passing through the substrate 60, and the holes move in the toner 62 of the present invention, and neutralize the charge on the toner. Also, the electrons move to the substrate 60 and neutralize the induced charge.

The transfer paper 66 is subjected to corona charging using a charger 67 (FIG. 5-4), and the charged toner 62 'in the dark area is transferred to the transfer paper 66 (FIG. 5-5).

The toner transferred onto the transfer paper 66 is transferred to heat rollers 67a, 67
According to b, by heating and fixing, a cyan color image corresponding to the dye contained in the toner can be obtained.

The components of the above formulation were hot-kneaded in a roll mill (150 ° C.) for about 30 minutes, and the obtained kneaded product was cooled and then pulverized for about 10 minutes.
The powder was crushed to a particle size of about 11 μm by a zigzag classifier manufactured by Alpine, to obtain a particle A of the present invention. The softening point was 125 ° C.

The volume particle size distribution in the range of 11 ± 3μ
There was a volume% of particles A.

Particle B containing a photoconductive substance was obtained by the following method.

After mixing the above components at a temperature of 60 ° C. for 4 hours using an attritor, 3 parts by weight of 2,2′-azobis- (2,4-dimethylvaleronitrile) was added to prepare a monomer composition.

Amino-modified silica (Aerosil # 20 manufactured by Nippon Aerosil)
100 parts by weight of 0 and 5 parts by weight of aminopropyltriethoxysilane were reacted) 12 parts by weight, 600 parts by weight of distilled water, 1 part by weight
The prepared monomer composition is added to a stainless steel container having a capacity of 2 containing 30 parts by weight of / 10N hydrochloric acid and stirred at 60 ° C. for 60 minutes at 10,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). To prepare a dispersion. This dispersion is homogenized by a piston type high-pressure machine (Gaulin Co., Ltd., Model 15M-8TA).
And granulated at a discharge pressure of 400 kg / cm ² . The time required for granulation was 5 minutes. After granulation, 60 hours with paddle stirring blades
The mixture was stirred under the condition of ° C. to complete the polymerization.

Thereafter, the mixture was cooled, washed with a sodium hydroxide solution, dehydrated, and dried to obtain particles. Tg was 90 ° C. The obtained particles had a volume average diameter of 1.2 μm.

Particles of 3μ or more have a volume particle size distribution of 10%
It was below.

Next, a mixture 250 of particles B was added to 1000 parts by weight of particles A.
The parts by weight were treated at 30 m / sec for 2 minutes using the apparatus shown in FIG.

Then, using the apparatus shown in FIG.
Processing was performed for 7 minutes at sec.

The temperature inside the machine was 50 ° C. The coverage was 98%.

Observation with an electron microscope revealed that the particles B were firmly fused and fixed to the surface of the particles A.

To 100 parts by weight of the toner, 0.5 parts by weight of colloidal silica was externally added.

The photoconductive toner thus obtained is put into an image forming apparatus schematically shown in FIG.

In FIG. 6, reference numeral 81 denotes a photosensitive drum which rotates in the direction of the arrow shown in the figure. First, the photosensitive drum is uniformly charged to a negative polarity by a corona charger 82, and then, in an optical unit 83, Exposure to an image-like pattern forms an electrostatic latent image. Next, when the latent image on the photosensitive drum 81 is moved to the developing unit 84, the latent image on the photosensitive drum 81 is charged with a positive () charge by the electric field between the toner supply member 87 and the photosensitive drum 81, and the photoconductive toner according to the present invention. 85 (toner of Example 2).

The developing unit 84 includes a permanent magnet 87a therein, and a sleeve-shaped toner supply member 87 that rotates in the direction of the arrow.
It is located close to 81. The surface of the toner supply member 87 is made of an appropriate material in consideration of injecting charges of the opposite polarity into the toner 85 according to the polarity of the latent image. The toner 85 held by magnetic force is applied to the toner supply member 87.
Is transported along the surface of the member 87 toward the photosensitive drum 81. At this time, the amount of toner can be regulated by the doctor blade 88.

At a position where the latent image on the photosensitive drum 81 and the toner supply member 87 are sufficiently close to each other, due to the action of the electric field generated between the two, charges are injected into the toner 85 from the toner supply member 87, Charges and develops the latent image. After the development, the photosensitive drum 1 further moves to the transfer section 89, where the transfer material 90 sent out from the paper supply section 86 is efficiently charged by a corona charger 91 that charges negatively.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing an example of a stirring device for pretreating particles A and B, and FIG. 2-1 is an apparatus for immobilizing particles B on particles A. FIG. 2-2 is a diagram schematically showing an example, FIG. 2-2 is a partially enlarged view of the apparatus in FIG. 2-1 and FIG. 3-1 is an apparatus for immobilizing particles B on particles A; FIG. 9 is a diagram schematically showing another example, and FIG.
2 and 3-3 are partial views of the apparatus of FIG. 3-1. FIG. 4-1 schematically shows an example of a pin mill type apparatus for fixing particles B to particles A. FIG.
FIG. 2 is a partial view of the apparatus shown in FIG. 4-1. FIGS. 5-1 to 5-6 show an image forming method used for producing an image using the toner of the present invention. FIG. 6 is a diagram schematically showing an image forming apparatus using the toner manufactured according to the present invention. DESCRIPTION OF SYMBOLS 1 ... Jacket, 2 ... Stirring blade 3 ... Motor, 4 ... Lid 5 ... Base, 6 ... Control plate 7 ... Cylinder, 8 ... Lock of lid 9 ... Cylinder 10 ... Direction control unit 11 ... outlet, 12 ... rotating shaft 13 ... rotor, 14 ... dispersion blade 15 ... rotating piece (blade), 16 ... partitioning disk 17 ... casing, 18 ... liner 19 ... impact part , 20… Inlet room 21… Outlet room, 22… Return path 23… Product take-out valve, 24… Raw material input valve 25… Blower, 26… Jacket 27… Rotating shaft, 28… Casing 29 …… Liner, 30… Blower blade 31 …… Rotor (with blade), 32 …… Outlet 33 …… Raw material inlet, 34 …… Return path 35 …… Product outlet, 36 …… Inlet 37 …… Jacket, 38 Casing 39 Fixing pin 40 Inlet 41 Material inlet 42 Circulating blower 43 Rita 44, Product outlet 45, Outlet 46, Rotor 47, Rotary shaft, 48, Jacket 60, Transparent conductive substrate 61, Photosensitive layer (charge generation layer) 62,85 Photoconductive toner 63, 67, 82, 89 Corona generator 82 Photosensitive drum 84 Developing device 66, 90 Transfer material

Continuing on the front page (72) Inventor Yasuhisa Akashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc. (72) Inventor Yasuhide Goseki 3- 30-2 Shimomaruko, Ota-ku, Tokyo Canon stock In-company (72) Inventor Masuo Yamazaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (56) References JP-A-60-258558 (JP, A) JP-A-60-175056 (JP, A) JP-A-60-165656 (JP, A) JP-A-63-250661 (JP, A)

Claims (1)

(57) [Claims] (1) Resin particles A and 0.1% of the resin particles A
A photoconductive resin particle B having a particle size ratio of 2 or less is prepared by rotating a rotating piece and a fixed piece,
Passing through an impact portion having a shortest gap of 0.5 to 5 mm formed from a kind of rotating piece, and the photoconductive particles B on the surface of the resin particles A at the impact portion.
And a method for producing a photoconductive toner.