JPH0540363A - Electrostatic latent image developing toner - Google Patents

Abstract

PURPOSE:To provide the electrostatic latent image developing toner which is free from fluctuations in toner compsn. and is excellent in electrostatic charge stability, flow property, etc., by immobilizing the fine particles for a surface treatment to the surfaces of toner core particles consisting essentially of the resin and/or forming the films thereof on these toner core particles in such a manner that the fine powder for the surface treatment are immobilized and/or formed as the films in the state of uniformly dispersing these particle in the surfaces of the toner core particles. CONSTITUTION:At least the toner core particles consisting essentially of the resin and the fine particles for the surface treatment are mixed and agitated by an agitating means 20 in a mixing chamber 10 in such a manner that the sticking thereof to the inside wall of the mixing chamber 10 is suppressed by a sticking suppressing means 30, by which the fine particles for the surface treatment are stuck to the surfaces of the toner core particles. The fine particles stuck in such a manner are immobilized to the surfaces of the toner core particles and/or are formed as the films thereon.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic latent image developing toner used for developing an electrostatic latent image in an image forming apparatus such as a copying machine or a printer. The present invention relates to an electrostatic latent image developing toner obtained by fixing fine particles for surface treatment and / or forming a film on the surface of toner core particles.

[0002]

2. Description of the Related Art Conventionally, in image forming apparatuses such as copying machines and printers, various toners have been used as developers for developing electrostatic latent images formed on photoconductors.

In recent years, in the image forming apparatus as described above, there is a demand for higher quality images to be formed, and accordingly, as the toner used for development, toner having a small particle size is used. It came to be considered.

Here, when manufacturing a toner having such a small particle diameter, it is difficult to uniformly disperse additives such as a charge control agent in the toner, and therefore the charge stability of the obtained toner is improved. However, there is a problem that the formed image is fogged or the toner is scattered and the inside of the image forming apparatus is soiled with the toner.

For this reason, in recent years, Japanese Patent Laid-Open No. 63-
As disclosed in Japanese Patent No. 85756 and Japanese Patent Laid-Open No. 63-244056, fine particles for surface treatment such as a coloring agent and a charge control agent are mainly used for impact force on the surface of toner core particles containing a resin as a main component. Immobilization or film formation using mechanical and thermal energy has been studied.

Here, when the fine particles for surface treatment such as a coloring agent and a charge control agent are fixed and / or formed into a film on the surface of the toner core particles as described above, generally, the toner core particles and the surface thereof are After mixing the fine particles for treatment with a V-type mixer, an automatic mortar, a Henschel mixer, etc., the mixture is mechanomill (Okada Seiko), Ongmill (Hosokawa Micron), hybridization system ( (Nara Machinery Co., Ltd.) and the like, and the fine particles for surface treatment are fixed and / or formed into a film on the surface of the toner core particles.

However, when the fine particles for surface treatment are fixed and / or formed into a film on the surface of the toner core particles in this way, when the toner core particles and the fine particles for surface treatment are mixed, the surface The fine particles for processing are mixed with the toner core particles in a solid state without being uniformly dispersed, and the fine particles for surface treatment are adhered to the surface of the toner core particles in a solid state, and the toner is solidified in such a state. The fine particles for surface treatment attached to the surface of the core particles are fixed and / or formed into a film on the surface of the toner core particles as they are,
There are problems that the obtained toner varies, the charge amount of the toner becomes unstable, and the fluidity of the toner becomes poor.

[0008]

SUMMARY OF THE INVENTION The present invention is directed to a copying machine,
In an image forming apparatus such as a printer, it is an object to solve the above problems in the toner for developing an electrostatic latent image used for developing an electrostatic latent image.

That is, according to the present invention, fine particles for surface treatment such as a colorant and a charge control agent are adhered to the surface of toner core particles containing a resin as a main component for immobilization and / or film formation treatment. Fine particles for surface treatment are fixed and / or formed into a film in a state of being uniformly dispersed on the surface of toner core particles, and there is no variation in toner composition, and excellent charging stability and fluidity are obtained. It is an object to provide a toner for developing an electrostatic latent image.

[0010]

According to the present invention, in order to solve the above problems, at least toner core particles containing a resin as a main component and fine particles for surface treatment are mixed in a mixer to obtain the fine particles. Is adhered to the surface of the toner core particles, and the thus adhered fine particles are fixed and / or film-formed on the surface of the toner core particles. And
In this mixer, the agitation means is used for mixing while suppressing the adhesion to the inner wall of the mixer by the adhesion suppressing means.

The toner core particles used in the electrostatic latent image developing toner according to the present invention are generally those obtained by the kneading-grinding method used for producing toner, The thing obtained by various methods, such as a wet granulation method, can be used.

When the wet granulation method is used, any known method may be used, and a suspension polymerization method or an emulsion polymerization method may be used. A granulation method that does not involve a polymerization process such as a turbidity method may be used.

Here, in the case of the suspension polymerization method, a polymerization composition containing a polymerizable monomer capable of forming a resin component, a polymerization initiator, and other additives such as a colorant in an aqueous medium is used. It is suspended in and polymerized to be granulated.

In addition, in the case of the emulsion polymerization method, it is preferable to use the method known as the seed polymerization method because a general emulsion polymerization has a good particle size distribution but only extremely fine particles can be obtained. That is, a part of the polymerizable monomer and a polymerization initiator are added to an aqueous medium obtained by adding an aqueous medium or an emulsifier, and the mixture is stirred and emulsified. It is preferable to obtain such particles, and perform the polymerization in the droplets of the polymerizable monomer using these particles as seeds. In this case, the polymerization may be performed in the droplets of the polymerizable monomer containing an additive such as a colorant.

Further, as a wet granulation method including other polymerization processes, a toner core particle is a soap-free emulsion polymerization method, a microcapsule method (interfacial polymerization method, in-situ polymerization method, etc.), a non-aqueous dispersion polymerization method, etc. May be manufactured.

On the other hand, in the case of the suspension method, an additive such as a colorant is blended with the resin component and melted or dissolved and dispersed in an appropriate organic solvent, and this is suspended in an aqueous medium and granulated. To do.

The liquid medium used in the above wet granulation method depends on the type of resin or polymerizable monomer contained in the toner composition, but is generally as follows. Something is used. First, among wet granulation methods including a polymerization process, water and a water / organic solvent mixture can be used in the suspension polymerization method, emulsion polymerization method, soap-free emulsion polymerization method, microcapsule method and the like. The organic solvent used here may be any one having a high affinity for water, for example, alcohols such as methanol, ethanol, propanol, butanol, ethylene glycol monomethyl ether, Ether alcohols such as ethylene glycol monoethyl ether, ethers such as tetrahydrofuran and dimethoxyethane are used,
These may be used as one kind or a mixture of two or more kinds.

Further, as a liquid medium used in the non-aqueous dispersion polymerization method among the wet granulation methods including the polymerization process, it exhibits solubility with respect to the monomer used but solubility with respect to the polymer produced. Any organic solvent may be used as long as it does not show.

As such an organic solvent, in addition to the above organic solvents, for example, aliphatic hydrocarbons such as pentane, hexane, octane, xylene, benzene, toluene and other alkylbenzenes, aromatic naphtha, etc. It is possible to use various organic solvents such as hydrocarbons, ketones, and ester-based organic solvents. These organic solvents may be used alone or in admixture of two or more, or may be used in admixture with water. It is appropriately selected and used accordingly.

In the wet granulation method that does not involve a polymerization process, any liquid medium may be used as long as it does not dissolve the resin used for the toner core particles. For example, the organic solvent as described above, Water / organic solvent mixture as well as water are used. The organic solvents may be used alone or in combination of two or more.

When the toner core particles are granulated in a wet process using the liquid medium as described above, the average particle size is usually set to 1 to 15 μm, preferably 2 to 10 μm. To do. Incidentally, when the toner core particles are granulated in the wet method as described above, it is easy to adjust those having a uniform particle size distribution such that the toner core particles are contained in an average particle size of ± 25% in an amount of 30% or more. Become.

The resin used for the toner core particles may be any resin that is generally used as a binder used in the production of toner, for example polystyrene. Thermoplastic resin such as resin, poly (meth) acrylic resin, polyolefin resin, polyamide resin, polycarbonate resin, polyether resin, polysulfone resin, polyester resin, epoxy resin, butadiene resin, or A thermosetting resin such as a urea resin, a urethane resin, a urea resin or an epoxy resin, or a copolymer, block polymer, graft polymer or polymer blend of these can be used. The above-mentioned resin is not limited to, for example, a resin in a complete polymer state such as a thermoplastic resin, and a resin containing an oligomer or a prepolymer, a crosslinking agent, etc. as in a thermosetting resin may be used. It is possible.

When the electrostatic image developing toner according to the present invention is used in a high speed system, it is necessary to fix the toner on a transfer paper or the like in a short time or to improve the separability from the fixing roller. Therefore, as the resin constituting the toner core particles, it is preferable to use a homopolymer or copolymer polymer synthesized from a styrene-based monomer, a (meth) acrylic-based monomer, a (meth) acrylate-based monomer, or a polyester-based resin.

In such a resin, the number average molecular weight Mn and the weight average molecular weight Mw are 1000 ≦.
Mn ≦ 10000, 20 ≦ Mw / Mn ≦ 70, and regarding the number average molecular weight Mn, 2,000 ≦ Mn ≦
It is desirable to use that which is 7,000.

When this electrostatic image developing toner is used as an oilless fixing toner, the resin forming the toner core particles has a glass transition point of 55 to 80 ° C. and a softening point of 80 to 150 ° C. Further, it is desirable to use the one containing 5 to 20% by weight of the gelling component.

Further, when the toner for developing an electrostatic image according to the present invention is used as a translucent color toner for full color, it is preferable to use a polyester resin as a resin constituting the toner core particles. ..

Here, the polyester resin constituting the toner core particles in the translucent color toner has a glass transition temperature of 55 to 70 ° C. and a softening point of 80 to 150 ° C.
It is desirable to use a linear polyester having a number average molecular weight Mn of 2000 to 15,000 and a molecular weight distribution (Mw / Mn) of 3 or less.

Further, a linear urethane-modified polyester obtained by reacting the above linear polyester resin with diisocyanate can also be used.

Here, the linear urethane-modified polyester is a linear polyester resin 1 composed of a dicarboxylic acid and a diol, having a number average molecular weight Mn of 2000 to 15,000, an oxidation of 5 or less, and a terminal group substantially having a hydroxyl group.
A linear urethane-modified polyester resin obtained by reacting 0.3 to 0.95 mol of diisocyanate with respect to mol, and having a glass transition temperature of 40 to 80.
A material whose main component is one whose oxidation is 5 ° C. or less is used.

Further, the above linear polyester is modified with a styrene-based, acrylic-based, aminoacrylic-based monomer or the like by a method such as grafting or block polymerization to obtain the same glass transition temperature, softening point, Those having a molecular weight characteristic can also be preferably used.

In the toner core particles, a colorant, a charge control agent, an offset preventive agent, etc. may be added in addition to the resin as described above.

On the other hand, as the fine particles for surface treatment mixed with the toner core particles, various coloring agents, charge control agents,
A fluidizing agent, an abrasive, a magnetic powder, an anti-offset agent, a resin fine particle and the like can be used alone or in combination, and generally, the average particle diameter thereof is 1/5 or less, preferably 1/10 of the toner core particle. Hereinafter, it is more preferable to use fine particles of 1/20 or less.

When the surface-treating fine particles are added to the toner core particles, if the amount of addition is too small, the surface-treating fine particles are uniformly treated on the surface of the toner core particles. On the other hand, while the effect of the fine particles for surface treatment is reduced, if the addition amount is too large, not all of the fine particles for surface treatment adhere to the toner core particles, but these exist alone to form particles. Therefore, 0.01 to 50 parts by weight, preferably 0.1 to 30 parts by weight, of such fine particles for surface treatment is usually added to 100 parts by weight of the toner core particles.

Here, as the colorant used as the fine particles for surface treatment, various organic or inorganic pigments or dyes of various colors as described below can be used.

First, as the black pigment, carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, non-magnetic ferrite, magnetic ferrite, magnetite or the like can be used.

The yellow pigments include yellow lead, zinc yellow,
Cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navels yellow, naphthol yellow S, bunzer yellow G, bunzer yellow 10G, benzidine yellow G, benzidine yellow GR, quinoline yellow rake, permanent yellow NCG, tartrazine rake. Etc. can be used.

As the orange pigment, red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, induslen brilliant orange RK, benzidine orange G, induslen brilliant orange GK and the like can be used.

As the red pigment, red iron oxide, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, resole red, pyrazolone red,
Watching red, calcium salt, lake red C,
Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B and the like can be used.

Further, as the purple pigment, manganese purple, fast violet B, netyl violet lake, etc. can be used.

As the blue pigment, navy blue, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partial chlorinated compound, fast sky blue, induslen blue BC, etc. may be used. You can

As the green pigment, chrome green, chrome oxide, pigment green B, malachite green lake, final yellow green G and the like can be used.

As the white pigment, zinc white, titanium oxide, antimony white, zinc sulfide and the like can be used.

As the extender pigment, barite powder, barium carbonate, clay, silica, white carbon, talc, alumina white and the like can be used.

Various dyes such as basic, acidic, disperse and direct dyes include nigrosine, methylene blue,
Rose bengal, quinoline yellow, ultramarine blue, etc. can be used.

When these colorants are used as fine particles for surface treatment, these colorants can be used alone or in combination.

When these colorants are mixed with the toner core particles as fine particles for surface treatment, if the amount of the colorant is too large, the fixing property of the toner is lowered, while the amount of the colorant is too small. Since the desired image density cannot be obtained, the amount of these colorants including the colorant contained in the toner core particles as described above is 1 to 20 with respect to 100 parts by weight of the resin in the toner. Parts by weight, preferably 2 to 10 parts by weight.

When the toner for developing an electrostatic image according to the present invention is used as the light-transmitting color toner as described above, various kinds of pigments and dyes of various colors as shown below are used as fine particles for surface treatment. Can be used.

Here, as the yellow pigment used for the translucent color toner, C.I. I. 10316 (Naphthol Yellow S), C.I. I. 11710 (Hansa Yellow 10
G), C.I. I. 11660 (Hansa Yellow 5G),
C. I. 11670 (Hansa Yellow 3G), C.I. I.
11680 (Hansa Yellow G), C.I. I. 11730
(Hansa Yellow GR), C.I. I. 11735 (Hansa Yellow A), C.I. I. 11740 (Hansa Yellow R
N), C.I. I. 12710 (Hansa Yellow R), C.I.
I. 12720 (Pigment Yellow L), C.I. I. Two
1090 (benzidine yellow), C.I. I. 21095
(Benzidine Yellow G), C.I. I. 21100 (Benzidine Yellow GR), C.I. I. 20040 (Permanent Yellow NCG), C.I. I. 21220 (Vulcan Fast Yellow 5), C.I. I. 21135 (Vulcan Fast Yellow R) or the like can be used.

Further, as the red pigment for the translucent color toner, C.I. I. 12055 (Stalin I), C.I.
I. 12075 (permanent orange), C.I. I. 1
2175 (Resor Fast Orange 3GL), C.I.
I. 12305 (Permanent Orange GTR), C.I.
I. 11725 (Hansa Yellow 3R), C.I. I. 21
165 (Vulcan Fast Orange GG), C.I. I. Two
1110 (benzidine orange G), C.I. I. 1212
0 (Permanent Red 4R), C.I. I. 1270 (Para Red), C.I. I. 12085 (Fire Red), C.I. I. 12315 (Brilliant Fast Scarlet), C.I. I. 12310 (Permanent Red F2R), C.I. I. 12335 (Permanent Red F
4R), C.I. I. 12440 (Permanent Red FR
L), C.I. I. 12460 (Permanent Red FRL
L), C.I. I. 12420 (Permanent Red F4R
H), C.I. I. 12450 (Light Fast Red Toner B), C.I. I. 12490 (Permanent Carmine FB), C.I. I. 15850 (Brilliant Carmine 6
B) and the like can be used.

As the blue pigment for the translucent color toner, C.I. I. 74100 (metal-free phthalocyanine blue), C.I. I. 74160 (phthalocyanine blue), C.I. I. 74180 (Fast Sky Blue) or the like can be used.

When these colorants for light-transmitting color toners are used as fine particles for surface treatment, they can be used alone or in combination as in the case of ordinary colorants, or in combination. The amount is 1 to 10 parts by weight, preferably 2 parts by weight, including 100 parts by weight of the resin in the toner, including the colorant contained in the toner core particles as described above.
~ 5 parts by weight.

When an offset preventing agent is used as the above-mentioned fine particles for surface treatment, as such an offset preventing agent, various waxes, particularly low molecular weight polypropylene, polyethylene, or polyolefins such as oxidized polypropylene and polyethylene are used. A system wax is preferably used.

When a charge control agent is used as the above-mentioned fine particles for surface treatment, examples of the positive charge control agent include azine compound Nigrosine base EX and Bontron N-01, 02, 04, 05, 07, 09. , 1
0,13 (manufactured by Orient Chemical Industry Co., Ltd.), oil black (manufactured by Chuo Synthetic Chemical Industry Co., Ltd.), quaternary ammonium salt P-5
1, polyamine compound P-52, Sudan Chief Schwarz BB (solvent black 3: C.I. No. 26)
150), Fetschwartz HBN (C.I. No. 2)
6150), Brilliant Spirits Schwarz TN
(Manufactured by Farben Fabriken Bayer Co., Ltd.), alkoxylated amines, alkylamides, molybdic acid chelate pigments, imidazole compounds, etc. can be used.
On the other hand, as the negative charge control agent, for example, chromium complex salt type azo dye S-32, 33, 34, 35, 37, 38, 4
0,44 (manufactured by Orient Chemical Industry Co., Ltd.), Eisenspiro Black TRH, BHH (manufactured by Hodogaya Chemical Co., Ltd.), Kayaset Black T-22,004 (manufactured by Nippon Kayaku Co., Ltd.), copper phthalocyanine dye S-39 (Orient Chemistry) Industrial Co., Ltd.), chromium complex salt E-81, 82 (Orient Chemical Co., Ltd.), zinc complex salt E-84 (Orient Chemical Co., Ltd.), aluminum complex salt E-86 (Orient Chemical Co., Ltd.), etc. You can

When these charge control agents are mixed with toner core particles as fine particles for surface treatment, if the amount of the charge control agent becomes too large, the charge amount of the toner becomes unstable and the toner is fixed. On the other hand, when the amount of the charge control agent is too small, the desired charge amount cannot be obtained. Therefore, the charge control agent including the charge control agent contained in the toner core particles as described above is used. Is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the resin in the toner.

When a fluidizing agent is used as the above-mentioned fine particles for surface treatment, for example, silica, aluminum oxide, titanium oxide, magnesium fluoride or the like can be used alone or in combination.

When non-magnetic inorganic fine particles are used as the above-mentioned fine particles for surface treatment, for example, silicon carbide, boron carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium dicarbide, tantalum carbide, niobium carbide, carbonized Various carbides such as tungsten, chromium carbide, molybdenum carbide, calcium carbide, diamond carbon random; various nitrides such as boron nitride, titanium nitride, zirconium nitride; boride such as zirconium boride; iron oxide, chromium oxide, oxidation Various oxides such as titanium, calcium oxide, magnesium oxide, zinc oxide, copper oxide, aluminum oxide, silica, colloidal silica and hydrophobic silica; sulfides such as molybdenum disulfide; fluorides such as magnesium fluoride and carbon fluoride Compound; Aluminum stearate, Steari Calcium, zinc stearate, various metal soaps such as magnesium stearate: talc, can be used various non-magnetic inorganic fine particles of bentonite. In addition, it is desirable that these fine particles be subjected to a hydrophobizing treatment before use.

When organic fine particles are used as the above-mentioned fine particles for surface treatment, for example, a wet polymerization method such as an emulsion polymerization method, a soap-free emulsion polymerization method or a non-aqueous dispersion polymerization method,
Various organic fine particles such as styrene-based, (meth) acrylic-based, benzoguanamine, melamine, Teflon, silicon, polyethylene and polypropylene which are granulated by a vapor phase method can be used.

When magnetic fine particles are used as the above-mentioned fine particles for surface treatment, for example, metals exhibiting ferromagnetism such as cobalt, iron and nickel, aluminum, cobalt, iron, lead, magnesium, nickel, zinc, Antimony, beryllium, bismuth, cadmium, calcium,
It is possible to use alloys of metals such as manganese, selenium, titanium, tungsten, vanadium, mixtures thereof, and fine particles of known magnetic materials such as oxides and fired bodies (ferrite).

When mixing the above-mentioned fine particles for surface treatment with the above-mentioned toner core particles, a mixer as shown in FIGS. 1 and 2 can be used.

Here, in the mixer shown in FIG. 1, the mixing chamber 1 for mixing the fine particles for surface treatment with the toner core particles.
The lower part of 0 was formed into a hemispherical shape and the upper part was formed into a cylindrical shape. Also,
As the stirring means 20 for mixing the fine particles for surface treatment with the toner core particles in the mixing chamber 10, the rotating shaft 21 is used.
The one provided with a plurality of stirring blades 22 was used.

Here, when the fine particles for surface treatment are mixed with the toner core particles by the stirring means 20 in the mixing chamber 10, the rotating shaft 21 of the stirring means 20 is a hemispherical lower part of the mixing chamber 10. To the inside of the mixing chamber 10 with a required angle of inclination, and the stirring blade 22 provided on the rotating shaft 21 is inclined within the mixing chamber 10 by the required angle. The rotary shaft 21 is connected to the motor 23.
By means of the belt 24 and the pulley 25, whereby the stirring blade 22 is rotated in the mixing chamber 10 in a tilted state at a required angle, and the stirring blade 22 causes the fine particles for surface treatment to be mixed with the toner core particles. Mixing was performed within 10.

In this mixing machine, the rotary shaft 21 of the stirring means 20 is used as the adhesion suppressing means 30 for suppressing the adhesion of the fine particles for surface treatment and the toner core particles to the inner wall 11 of the mixing chamber 10. Cylindrical rotating shaft 3 inserted
An arc-shaped first scraping member 31 corresponding to the inner shape of the lower part of the mixing chamber 10 is attached to the la 1a, and the first scraping member 31 is attached to the inner wall 11 of the lower part of the mixing chamber 10.
To the rotary shaft 32a extending from the upper part of the mixing chamber 10 into the mixing chamber 10
A second scraping member 32 having a groove shape corresponding to the internal shape of the upper portion is attached, and the second scraping member 3 is attached.
2 was brought into close contact with the inner wall 11 above the mixing chamber 10.

Then, the rotating shaft 31a to which the first scraping member 31 is attached is rotated by the motor 31b via the belt 31c and the pulley 31d, and the first scraping member 31 is moved to the inner wall 11 below the mixing chamber 10. The second scraping member 32 is rotated in close contact with the second scraping member 32.
The rotating shaft 32a to which is attached is rotated by the motor 32b via the belt 32c and the pulley 32d so that the second scraping member 32 is brought into close contact with the inner wall 11 of the upper part of the mixing chamber 10 to rotate, and Surface-treating fine particles and toner core particles adhering to the lower and upper inner walls 11 are scraped off by the first and second scraping members 31, 32.
Was scraped off from the inner wall 11 of the mixing chamber 10.

In this mixer, fine particles for surface treatment and toner core particles attached to the inner wall 11 at the lower and upper portions of the mixing chamber 10 as described above are removed by the first and second scraping members 31, 32. When the fine particles for surface treatment are mixed with the toner core particles by the stirring blade 22 of the stirring means 20 while scraping off, the fine particles for surface treatment do not adhere to the inner wall 11 of the mixing chamber 10 and harden, and The fine particles for treatment are crushed into the state of primary particles and mixed with the toner core particles in a sufficiently dispersed state, and the fine particles for surface treatment are uniformly dispersed on the surface of the toner core particles in the state of primary particles. Started to adhere.

In this mixing machine, since the stirring blade 22 is rotated in the mixing chamber 10 in a state in which it is tilted at a required angle as described above, the stirring blade 22 causes the fine particles for surface treatment to become a toner. The stress on these particles was also reduced when mixed with the core particles.

The mixing machine shown in FIG. 2 is also substantially the same as the mixing machine shown in FIG. 1, but in this mixing machine, a mixing chamber for mixing fine particles for surface treatment with toner core particles is used. 10 was formed into a spherical shape, and the mixing chamber 10 itself was allowed to freely tilt. Then, as the adhesion suppressing means 30 for suppressing the adhesion of the fine particles for surface treatment and the toner core particles to the inner wall 11 of the mixing chamber 10, the stirring means 20 is used.
The scraping member 33 having a ring shape corresponding to the internal shape of the mixing chamber 10 is attached to the cylindrical rotating shaft 33a through which the rotating shaft 21 of FIG.
3 was brought into close contact with the inner wall 11 of the mixing chamber 10.

Also in this mixer, the rotary shaft 33a to which the scraping member 33 is attached is rotated by the motor 33b via the belt 33c and the pulley 33d, and the scraping member 31 is moved to the inner wall of the mixing chamber 10. It was rotated in a state of being in close contact with 11, and fine particles for surface treatment and toner core particles adhering to the inner wall 11 of the mixing chamber 10 were scraped off by the scraping member 33.

Here, when the toner core particles and the fine particles for surface treatment are mixed using the mixers shown in FIGS. 1 and 2, the temperature of the mixing chamber 10 is generally set to 5
˜60 ° C., treatment time 1˜20 minutes, the peripheral speed of the tip of each stirring blade 22 is in the range of 10˜100 m / sec, and the internal pressure of the mixing chamber 10 is 1˜1.
It is preferable to carry out at about 2 atm.

In each of the mixers shown in FIGS. 1 and 2, fine particles for surface treatment and toner core particles are mixed in the mixing chamber 10.
Each of the scraping members 31, 32, and 33 as described above is provided as the adhesion suppressing means 30 for suppressing adhesion to the inner wall of the above. However, the adhesion suppressing means 30 is not limited to the above. Instead, for example, an ultrasonic vibration machine or the like that vibrates the inner wall 11 of the mixing chamber 10 and suppresses fine particles for surface treatment and toner core particles from adhering to the inner wall 11 of the mixing chamber 10 is used as the adhesion suppressing unit 30. It is also possible to do so. In addition, the scraping members 31, 3
The operating conditions of Nos. 2 and 33 need to be appropriately set according to the types and amounts of the surface treatment particles and the toner core particles so that the surface treatment particles and the toner core particles do not adhere to the inner wall 11 of the processing chamber 10. is there.

[0070]

In the toner for developing an electrostatic latent image according to the present invention, the toner core particles containing at least the resin as a main component and the fine particles for surface treatment are mixed and stirred in the mixer as described above, While suppressing adhesion of the particles and the fine particles for surface treatment to the inner wall of the mixer during mixing by the adhesion suppressing means, the fine particles for surface treatment are mixed and stirred with the toner core particles by the stirring means in the mixer. Therefore, the fine particles for surface treatment do not adhere to the inner wall of the mixer and harden, and the fine particles for surface treatment are mixed with the toner core particles in a sufficiently dispersed state to form the toner core particles. The fine particles for surface treatment adhere to the surface in a state of being uniformly dispersed.

Then, the fine particles for surface treatment, which are adhered to the surface of the toner core particles in a uniformly dispersed state, are fixed and / or formed into a film on the surface of the toner core particles. A toner for developing an electrostatic latent image having excellent charge stability and fluidity can be obtained.

[0072]

EXAMPLES The electrostatic latent image developing toner according to the examples of the present invention will be specifically described below, and the electrostatic latent image developing toners according to the examples of the present invention will be compared with the comparative electrostatic latent image developing toner. It is revealed that the toner for developing the electrostatic latent image is excellent.

(Example 1) In this example, the toner core particles A produced as described below were used.

Here, in producing the toner core particles A, 100 parts by weight of a styrene monomer, 35 parts by weight of n-butyl methacrylate, 5 parts by weight of methacrylic acid, and 2,2-azobis- (2,4-). Dimethyl valeronitrile) 0.5 part by weight, low molecular weight polypropylene (manufactured by Sanyo Kasei Kogyo KK, Viscole 605P) 3 parts by weight, and carbon black (Mitsubishi Kasei Kogyo KK, MA # 8) 8 parts by weight by a sand stirrer A polymerization composition was prepared by mixing.

Then, this polymerization composition was put into an aqueous solution of gum arabic having a concentration of 3%, and these were rotated with a stirrer (TK Auto Homomixer manufactured by Tokushu Kika Kogyo Co., Ltd.) at a rotation speed of 40
While stirring at 00 rpm, a polymerization reaction was carried out at a temperature of 60 ° C. for 6 hours, and then the rotation speed of the agitator was set to 2000 rp.
m, and the temperature is raised to 85 ° C. to agglomerate the polymerized particles with each other.
50 by sticking to the surface of fine particles of μm or more and melting
Aggregate to about 1 μm to 1 mm, dry it to 100
Aggregates of about μm to 2 mm were obtained.

Next, this aggregate was crushed by a jet mill and further classified by wind to produce toner core particles A having an average particle size of 6 μm.

In this embodiment, a zinc complex salt compound (E-84, manufactured by Orient Chemical Industry Co., Ltd.) was used as fine particles for surface treatment with respect to 100 parts by weight of the toner core particles A produced as described above. 0.5 parts by weight of the charge control agent was added, and the particles were mixed and stirred by the mixer shown in FIG.

Here, when mixing and stirring these particles with the above mixer, the peripheral speed of the tip of the stirring blade 22 having the longest blade length is 40 m / sec. As described above, the stirring blades 22 are rotated by the rotating shaft 21, and the first and second scraping members 31, 32 are moved by the stirring blades 22.
The scraping members 31 and 32 are rotated at a rotation speed of 50 rpm so that the normal rotation and the reverse rotation are performed every 10 seconds with respect to the rotation direction, and the particles adhere to the inner wall 11 of the mixing chamber 10. While preventing the above by the first and second scraping members 31 and 32, these particles were mixed and stirred for 5 minutes by the respective stirring blades 22.

Then, these particles mixed as described above were subjected to a peripheral speed of 80 m / sec using a hybridization system NHS-3 type (manufactured by Nara Machinery Co., Ltd.).
For 5 minutes to immobilize the above charge control agent on the surface of the toner core particle A to obtain a black toner having an average particle size of 6 μm.

Example 2 In this example, the toner core particles B manufactured as follows were used.

In the production of the toner core particles B, in the production of the toner core particles A in the above-mentioned Example 1, no low molecular weight polypropylene (manufactured by Sanyo Kasei Co., Ltd., Viscole 605P) was added, and otherwise. A toner core particle B having an average particle diameter of 6 μm was manufactured in the same manner as the toner core particle A.

In this example, 100 parts by weight of the toner core particles B produced as described above were used as fine particles for surface treatment as a chromium complex salt type dye (manufactured by Hodogaya Chemical Co., Ltd., Eisenspirone). Black TRH)
And 0.5 parts by weight of a charge control agent consisting of hydrophobic silica (R-974 manufactured by Nippon Aerosil Co., Ltd.).
0 part by weight was added, and these particles were treated in the same manner as in Example 1 above to obtain a black toner having an average particle size of 6 μm.

(Example 3) In this example, the same toner core particles A as in Example 1 were used.
Then, with respect to 100 parts by weight of the toner core particles A, 1.0 part by weight of a charge control agent composed of a quaternary ammonium salt compound (P-51 manufactured by Orient Chemical Industry Co., Ltd.) as fine particles for surface treatment, and And 1.0 part by weight of a superplasticizer consisting of hydrophobic silica of Example 1 was added to the particles shown in FIG.
A black toner having an average particle size of 6 μm was obtained in the same manner as in Example 1 except that the mixing and stirring was performed using the mixer shown in FIG.

(Example 4) In this example, the toner core particles C produced as follows were used.

In producing the toner core particles C, 100 parts by weight of styrene-n-butyl methacrylate resin (softening point: 108 ° C., glass transition point: 52 ° C.),
Carbon black (Mitsubishi Kasei Co., Ltd., MA # 8) 10
3 parts by weight of low-molecular-weight polypropylene (manufactured by Sanyo Kasei Kogyo Co., Ltd., VISCOL 605P) were thoroughly mixed in a ball mill, and then kneaded by a three-roll mill heated to 140 ° C. The kneaded product was left to cool, coarsely pulverized with a feather mill, finely pulverized with a jet mill, and then air-classified to obtain a toner having an average particle size of 8 μm. Core particles C were produced.

In this example, 100 parts by weight of the toner core particles C produced as described above were used as fine particles for surface treatment, and chromium complex salt type azo dye (Orient Chemical Co., Ltd., S-34) was used. 1.0 part by weight of a charge control agent consisting of 10 parts by weight of these particles was mixed using the mixer shown in FIG. 1 under the same conditions as in Example 1 above. (Made by Matic Industry Co., Ltd.)
℃, the time until the temperature of the air flow reaches the glass transition temperature of the toner core particles is 0.7 seconds, the dispersion concentration of the mixture in the air flow is set to 200 g / m ² , and the immobilization treatment is performed. A black toner having an average particle size of 8 μm was obtained.

(Example 5) In this example, the toner core particles D produced as follows were used.

In producing the toner core particles D, in the production of the toner core particles C in the above-mentioned Example 4, instead of the styrene-n-butylmethacrylate resin, a polyerter resin (Tafton NE-38, manufactured by Kao Corporation) was used.
2) was used, and otherwise the same as in the case of the toner core particles C, and the toner core particles D having an average particle diameter of 7.5 μm were produced.

In this embodiment, 100 parts by weight of the toner core particles D produced as described above are used as fine particles for surface treatment, and the charge control agent of the quaternary ammonium salt of 1.5 is used. Parts by weight and 1.0 part by weight of a fluidizing agent made of hydrophobic titanium oxide (T-805, manufactured by Degussa) were added, and these particles were mixed using the mixer shown in FIG. Otherwise, the average particle size was 7.5 μm in the same manner as in Example 4 above.
To obtain a black toner.

Comparative Example 1 In this comparative example, the same toner core particles A as in Example 1 were used. Then, to 100 parts by weight of the toner core particles A, 1.0 part by weight of a charge control agent composed of the chromium complex salt dye was added as fine particles for surface treatment, and the particles were put into a Henschel mixer to rotate at 3000 rpm. After mixing for 1 minute, the mixture is put into the above-mentioned hybridization system NHS-3 type and fixed for 5 minutes at a peripheral speed of 80 m / sec to obtain a black toner having an average particle size of 6 μm. It was

(Comparative Example 2) In this comparative example, the same toner core particles B as in Example 2 were used. Then, to 100 parts by weight of the toner core particles B, 1.5 parts by weight of the charge control agent composed of the quaternary ammonium salt compound as fine particles for surface treatment was added, and these particles were the same as in Comparative Example 1 above. The average particle size is 6μ
m black toner was obtained.

Comparative Example 3 In this comparative example, the same toner core particles C as in Example 4 were used. Then, with respect to 100 parts by weight of the toner core particles C, 1.0 part by weight of the charge control agent composed of the chromium complex salt type azo dye described above and a fluidizing agent composed of hydrophobic titanium oxide as fine particles for surface treatment 1. 0 parts by weight were added, and these particles were mixed using a Henschel mixer in the same manner as in Comparative Example 1 above.

Then, the particles thus mixed are introduced into a suffusing system (manufactured by Nippon Pneumatic Mfg. Co., Ltd.) in the same manner as in Example 4, and the maximum airflow temperature is 350 ° C. and the airflow temperature is the toner core. Immobilization treatment was performed under the conditions that the time required for the particles to reach the glass transition temperature or lower was 0.7 seconds and the dispersion concentration of the mixture in the airflow was 200 g / m ² , and the average particle diameter was 8 μm. A black toner was obtained.

Example 6 In this example, the toner core particles had an average particle size of 5 obtained by the seed polymerization method.
μm monodisperse spherical styrene and n-butyl methacrylate copolymer polymer particles (glass transition temperature 54 ° C.,
Gelling component 1 with a softening point of 128 ° C and toluene insoluble matter
5%) was used.

Then, to 100 parts by weight of the toner core particles, 8 parts by weight of carbon black (MA # 8 manufactured by Mitsubishi Kasei Kogyo Co., Ltd.) was added as fine particles for surface treatment, and the mixer shown in FIG. 2 was used. Then, in the state where the angle of the mixing chamber 10 in this mixer is inclined by 45 °, the stirring blade 2
2 of the stirring blades 22 having the longest blade length, the peripheral speed of the tip portion of the stirring blade 22 is 40 m / sec.
1, the stirring blades 22 are rotated, and at the same time, the scraping member 33 performs normal rotation and reversal with respect to the rotation direction of the stirring blades 22 every 10 seconds, so that the scraping member 33 is rotated at a rotational speed. Rotate at 50 rpm, mixing chamber 1
While preventing the above particles from adhering to the inner wall 11 of 0 by the scraping member 33,
In step 2, these particles were mixed and stirred for 1 minute to attach carbon black to the surface of the toner core particles.

Next, the thus obtained toner core particles to which carbon black is adhered is treated for 3 minutes at 6000 rpm using a hybridization system NHS-1 type (manufactured by Nara Machinery Co., Ltd.) to obtain the above carbon black. It was fixed on the surface of the toner core particles.

Then, with respect to 100 parts by weight of the toner core particles on which carbon black is fixed as described above, the average particle diameter of methyl methacrylate / i-butyl methacrylate = 1/9 as fine particles for surface treatment. Is 0.
2 μm resin fine particles (manufactured by Soken Chemical Industry Co., Ltd., MP-4951,
30 parts by weight of glass transition temperature (85 ° C.) and 1 part by weight of a charge control agent composed of the zinc complex salt compound are added, and these particles are mixed under the same mixing conditions as above using a mixer shown in FIG. After mixing and stirring for 3 minutes, this mixture was treated for 3 minutes at a rotation speed of 7,000 rpm using the above-mentioned hybridization system NHS-1 type to obtain a toner having a three-layer structure and an average particle diameter of 6 μm.

COMPARATIVE EXAMPLE 4 In this comparative example, the toner core particles and the carbon black-immobilized toner core particles and the resin fine particles (MP, manufactured by Soken Kagaku Co., Ltd.) in Example 6 were mixed. -4951,
When mixing the glass transition temperature (85 ° C.) and the zinc complex salt compound, each was mixed for 2 minutes at a peripheral speed of 40 m / sec using a Henschel mixer, and otherwise the toner was prepared in the same manner as in Example 6 above. Manufactured.

Next, Example 1 produced as described above
6 to 6 and Comparative Examples 1 to 4, the average charge amount [μC / g], poorly charged toner amount [weight%], and toner scattering amount are examined, and the fog of the formed image is evaluated. did.

In the evaluation of the toners of Examples 1 to 6 and Comparative Examples 1 to 4, 100 parts by weight of each toner was used to colloidal silica (R-972, manufactured by Nippon Aerosil Co., Ltd.). 0.2 part by weight was added and post-treated.

In making these evaluations,
Each of the toners of Examples 1 to 6 and Comparative Examples 1 to 4 was mixed with a binder type carrier produced as follows, and evaluated in the state of a two-component developer.

Here, as the binder type carrier, polyester resin (NE-111 manufactured by Kao Corporation) is used.
0) 100 parts by weight and inorganic magnetic powder (manufactured by Toda Kogyo Co., EP
T-1000) 500 parts by weight and carbon black (MA # 8 manufactured by Mitsubishi Kasei Co., Ltd.) 2 parts by weight were thoroughly mixed, pulverized, and then set to 180 ° C. for the cylinder part and 170 ° C. for the cylinder head part. Binder having an average particle diameter of 55 μm obtained by melt-kneading using an extrusion kneader, cooling and roughly crushing this kneaded product, finely crushing with a jet mill, and further classifying with a wind classifier. A mold carrier was used.

The above Examples 1 to 6 and Comparative Examples 1 to
In measuring the average particle size of each toner in 4 and the average particle size of the carrier, a laser diffraction particle size distribution analyzer (manufactured by Shimadzu Corporation, SALD-1100) was used.

In measuring the charge amount and the poorly charged toner amount of each of the toners of Examples 1 to 6 and Comparative Examples 1 to 4 using the above binder type carrier, the above amount was measured for 2 g of each toner. 2 careers
8 g was added, and these were put in a plastic bottle of 50 cc and rotated at 120 rpm for 10 minutes on a rotary stand.

Then, 3 g of the developer containing each toner thus adjusted was weighed with a precision balance, and the amount of electrification and the amount of poorly electrified toner of each toner was measured using the apparatus shown in FIG.

Here, in measuring the charge amount of each toner and the amount of poorly charged toner by using the apparatus shown in FIG. 3, each developer measured as described above is evenly distributed over the entire surface of the conductive sleeve 1. And put it so that
The rotation speed of the magnet roll 2 provided in the conductive sleeve 1 was set to 100 rpm.

Then, a bias voltage of 0 to 10 KV is sequentially applied from the bias power source 3, the conductive sleeve 1 is rotated for 5 seconds, and the potential Vm at the cylindrical electrode 4 at the time when the conductive sleeve 1 is stopped is read. At the same time, the weight of the toner attached to the cylindrical electrode 4 from the conductive sleeve 1 was measured by a precision balance to obtain the average charge amount [μC / g] of each toner, and the results are shown in Table 1 below. ..

Further, the results of the above measurements are tabulated to measure the charge amount distribution of each toner contained in the developer, and based on this charge amount distribution, the average charge amount [μC / G], the amount of toner having a charge amount of ⅕ or less was determined, and the value is shown in Table 1 below as the amount of poorly charged toner [wt%].

The above Examples 1 to 6 and Comparative Examples 1 to
In examining the amount of scattering in each toner of No. 4, the developer containing each toner of Examples 1 to 6 and Comparative Examples 1 to 4 was used in the same manner as in the case of measuring the average charge amount [μC / g]. It was adjusted.

To check the amount of scattering in each toner, a digital dust meter P5H2 (manufactured by Shibata Chemical Co., Ltd.) was used.
The developer containing the respective toners adjusted as described above is set on the magnet rolls at a distance of m.
After setting g, this magnet roll is 2000 rp
The amount of each toner that generated dust when rotated at m was read by the above dust meter, and the count number [cpm] per minute was obtained.

Then, when the count number per minute thus obtained is 300 cpm or less, it is ◯, and 500 cp.
Table 1 below shows Δ when m or less and x when more than 500 cpm.

Further, in evaluating the fogging of the image formed, the above carrier was used for each of the toners of Examples 1 to 6 and Comparative Examples 1 to 4 as toner / carrier =
Mixing to give a weight ratio of 5/95, Examples 1-6
A two-component developer using each toner of Comparative Examples 1 to 4 was prepared.

For the developers using the toners of Examples 1, 2, 4, 6 and Comparative Examples 1, 3, 4, a commercially available copying machine (EP-570Z manufactured by Minolta Camera Co., Ltd.) was used. A fixing device improved to an oil coating system is used, while a commercially available copying machine (manufactured by Minolta Camera, EP, is used for the developers using the toners of Examples 3 and 5 and Comparative Example 2). -8600) was used.

Then, using these copying machines, a printing durability test of 100,000 sheets was conducted using a chart having a black ratio of 6%, and formed at the initial, 10,000, and 100,000 sheet tests. The fogging of the images was evaluated.

Here, in the evaluation of image fogging, ◯ means good, Δ means slight fogging but practically usable, and Δ means practically problematic. It was shown to.

[0116]

[Table 1]

As is clear from this result, when the toners of Examples 1 to 6 are used, the amount of defectively charged toner is significantly smaller than that when the toners of Comparative Examples 1 to 4 are used. As a result, the amount of toner scattering and fog in the formed image were reduced.

When the toner of Comparative Example 4 was used, the resin fine particles were not sufficiently adhered to the surface of the toner core particles, and the resin fine particles adhered to the surface of the sleeve to cause developer spillage. A large amount of toner was generated, and it was not possible to evaluate the amount of toner scattered and fogging in the formed image.

Further, with respect to each of the toners of Example 6 and Comparative Example 4, the content ratio of the released fine particles in the toner was measured.

Here, in measuring the content rate of the released fine particles in these toners, a small amount of each developer using each toner is sampled and dispersed in an aqueous solution in which a trace amount of a surfactant is dissolved. After ultrasonically dispersing the dispersion, only the carrier was removed with a magnet, and the particle size distribution of each toner was determined using a laser diffraction particle size distribution analyzer (Shimadzu Corporation SALD-1100).

Then, based on the particle size distribution of each toner thus obtained, the ratio of the weight particle size distribution of the particles having a particle size of 0.1 μm or more and half or less of the weight average particle size of each toner is calculated to obtain fine particles. The content rate (%) was measured.

As a result, in the toner of Comparative Example 4, the content of fine particles was as high as 3.6%, and the fine particles for surface treatment were not sufficiently treated on the surface of the toner core particles and were liberated. On the other hand, in the toner of Example 6, the content rate of the fine particles was as low as 0.2%, and the fine particles for surface treatment were sufficiently treated on the surface of the toner core particles.

SEM observation of the toners of Example 6 and Comparative Example 4 revealed that in the toner of Comparative Example 4, fine particles for surface treatment were partially formed on the surface of the toner core particles. However, a large number of particles composed of the resin fine particles, the resin fine particles aggregated with each other, the zinc complex salt compounds aggregated with each other, the resin fine particles and the zinc complex salt compound aggregated with each other were observed, whereas In the toner of Example 6, fine particles for surface treatment were formed into a film in good condition on the surface of the toner core particles.

[0124]

As described above in detail, in the toner for developing an electrostatic latent image according to the present invention, at least toner core particles containing a resin as a main component and fine particles for surface treatment are mixed and stirred in a mixer. At this time, while suppressing the adhesion of the toner core particles and the fine particles for surface treatment to the inner wall of the mixer during mixing by the adhesion suppressing means, the fine particles for surface treatment are mixed with the toner core by the stirring means in the mixer. Since the particles are mixed and stirred with the particles, the particles for surface treatment do not adhere to the inner wall of the mixer and harden, and the particles for surface treatment are mixed with the toner core particles in a sufficiently dispersed state, The fine particles for treatment adhere to the surface of the toner core particles in a uniformly dispersed state, and in this state, the fine particles for surface treatment are fixed and / or formed into a film on the surface of the toner core particles. It became way.

As a result, in the toner for developing an electrostatic latent image according to the present invention, the particles for surface treatment are fixed to the surface of the toner core particles in a state of being hardened like the conventional toner for developing an electrostatic latent image. And / or the composition of the toner does not fluctuate due to being formed into a film, the charging stability and fluidity are excellent, and good image formation can be performed.

[Brief description of drawings]

FIG. 1 is a schematic explanatory view of a mixer used for mixing toner core particles containing a resin as a main component and fine particles for surface treatment in the electrostatic latent image developing toner according to the present invention.

FIG. 2 is a schematic explanatory view of another mixer used for mixing toner core particles containing a resin as a main component and fine particles for surface treatment in the electrostatic latent image developing toner according to the present invention. ..

FIG. 3 is a schematic view of an apparatus used to measure the charge amount of toner.

[Explanation of symbols]

 10 Mixing Chamber 11 Inner Wall 20 Stirring Means 30 Adhesion Suppressing Means

Claims (1)

[Claims] 1. A toner core particle containing at least a resin as a main component and fine particles for surface treatment are mixed in a mixer, and the fine particles are adhered to the surface of the toner core particle. In the electrostatic latent image developing toner obtained by fixing and / or forming a film on the surface of particles, the adhesion suppressing means suppresses the adhesion of the toner core particles and the fine particles to the inner wall of the mixer. An electrostatic latent image developing toner characterized by being mixed by a stirring means in this mixer.