JPH05127415A - Toner for development of electrostatic latent image - Google Patents

Abstract

PURPOSE:To obtain a toner for the development of electrostatic latent images having a fluidizing agent is deposited on the surface of toner particles in a manner that the fluidizing agent in a primary particle state is uniformly dispersed and deposited on the surface of the toner particles, so that the toner particles have excellent fluidity and uniform characteristics such as electrifying property and high quality picture images can be stably formed. CONSTITUTION:The toner for development of electrostatic latent images is obtd. by mixing at least toner particles essentially comprising a thermoplastic resin and a fluidizing agent so that the fluidizing agent is deposited on the surface of toner particles. The number average particle size DN of the fluidizing agent deposited on the surface of toner particles is in the range of 0.005mum<=DN<=0.5mum, and contains <=5 number % of particles having a partice size three times as large as the number mean particle size DN.

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, and more particularly to at least a thermoplastic resin. The present invention relates to a toner for developing an electrostatic latent image in which toner particles containing as a main component and a fluidizing agent are mixed and the fluidizing agent is attached to the surface of the toner particles.

[0002]

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

In recent years, it has been desired to improve the image quality of an image formed by the above-mentioned image forming apparatus. Therefore, various kinds of toner for developing the electrostatic latent image as described above used for development are also required. Various studies have been made to improve the fluidity of the toner for developing an electrostatic latent image, and to improve the transportability and the charging property of the toner.

In order to improve the fluidity of the toner for developing an electrostatic latent image as described above, conventionally, for example, JP-A-48-47346 and JP-A-56-12 are known.
As disclosed in JP-A-8956 and JP-A-59-52255, a fluidizing agent such as colloidal silica or titanium oxide is mixed with toner particles to adhere the fluidizing agent to the surface of the toner particles. A toner for developing an electrostatic latent image has been developed.

Here, when the toner particles and the fluidizing agent are mixed as described above and the fluidizing agent is attached to the surface of the toner particles, conventionally, the toner particles and the fluidizing agent are generally V type. The mixing was performed by using a mixing machine, an automatic mortar, a Henschel mixer, or the like.

However, when the toner particles and the fluidizing agent are mixed in this manner, the fluidizing agents are so small that the fluidizing agents are agglomerated, and thus the agglomerated state. As a result, the fluidizing agent was unevenly attached to the surface of the toner particles.

If the fluidizing agent is unevenly adhered to the surface of the toner particles as described above, the fluidity of the obtained toner for developing an electrostatic latent image is not sufficiently improved, and the characteristics such as its charging property are improved. Occurs, the charge amount of the electrostatic latent image developing toner is not constant, and when the electrostatic latent image developing toner is used for development, the image quality of the formed image is deteriorated. There was a problem.

If the amount of the fluidizing agent to be mixed with the toner particles is increased in order to increase the fluidity of the toner, the resulting electrostatic latent image developing toner will have poor environmental stability and the toner will also be deteriorated. There has been a problem that the aggregate of the fluidizing agent released from the particles increases, and the obtained electrostatic latent image developing toner has further large variations in characteristics such as charging properties.

[0009]

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, the present invention provides a toner for developing an electrostatic latent image in which toner particles containing at least a thermoplastic resin as a main component and a fluidizing agent are mixed and the fluidizing agent is attached to the surface of the toner particles. , The fluidizing agent is attached in the state of primary particles in a state of being uniformly dispersed on the surface of the toner particles, so that the fluidity is excellent and the characteristics such as the charging property do not vary and high-quality image formation is achieved. It is an object of the present invention to provide a toner for electrostatic latent image development that can be stably performed.

[0011]

In the present invention, in order to solve the above problems, at least toner particles containing a thermoplastic resin as a main component and a fluidizing agent are mixed,
In the electrostatic latent image developing toner in which the fluidizing agent is attached to the surface of the toner particles, the number average particle diameter D _{N of} the fluidizing agent attached to the surface of the toner particles is 0.005 μm ≦ D _N ≦
The number of fluidizing agents having a particle size of 0.5 μm and 3 times or more the number average particle diameter D _N is 5% or less. More preferably, the fluidizing agent having a particle size of 5 times or more of D _N should be 1% by number or less.

Here, in the toner for developing an electrostatic latent image according to the present invention, as the toner particles, a kneading-grinding method, a spray drying method and a wet granulation method which are generally used for producing toner are used. For example, those manufactured by various known methods can be used.

When the toner particles are produced by the wet granulation method, any known method may be used, including suspension polymerization method, emulsion polymerization method, soap-free emulsion polymerization method and microcapsule method ( Interfacial polymerization method, in-situ
Polymerization method), a non-aqueous dispersion polymerization method or the like, or a granulation method without a polymerization process such as a suspension method.

When the toner particles are manufactured by the wet granulation method as described above, the average particle diameter of the toner particles is usually set to 1 to 15 μm, preferably 2 to 10 μm. To do. When the toner particles are manufactured by the wet granulation method as described above, the average particle size ±
In the range of 25%, 30% or more of the toner particles are contained, and it becomes easy to adjust the particles having a uniform particle size distribution.

The resin used for the toner particles is
Any resin may be used as long as it is generally used as a binder in the production of toner, and examples thereof include polystyrene resin, poly (meth) acrylic resin, polyolefin resin, polyamide resin. , Thermoplastic resin such as polycarbonate resin, polyether resin, polysulfone resin, polyester resin, epoxy resin, butadiene resin, or thermosetting resin such as urea resin, urethane resin, urea resin, epoxy resin, Further, these copolymers, block polymers, graft polymers, polymer blends and the like can be used. The resin is not limited to, for example, a resin in a complete polymer state such as a thermoplastic resin,
It is also possible to use those containing oligomers or prepolymers such as in thermosetting resins, crosslinking agents and the like.

When the electrostatic latent 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, it is preferable to use a homopolymer or copolymer polymer synthesized from a styrene monomer, a (meth) acrylic monomer, a (meth) acrylate monomer, or a polyester resin as the resin forming the toner particles.

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 latent image developing toner is used as an oilless fixing toner, the resin forming the toner 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 electrostatic latent image developing toner according to the present invention is used as a full-color translucent color toner, it is preferable to use a polyester resin as the resin forming the toner particles. ..

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

Further, 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 a glass transition temperature, a softening point, and a glass transition temperature similar to those of the linear urethane-modified polyester. Those having a molecular weight characteristic can also be preferably used.

In addition to the resin as described above, a colorant, a charge control agent, an offset preventing agent and the like may be added to the toner particles.

Here, as the colorant used in the toner for developing an electrostatic latent image according to the present invention, various known organic or inorganic pigments and dyes of various colors which have been conventionally used in the production of toner are used. It is also possible to use these colorants alone or in combination of plural kinds.

In addition, in incorporating these colorants into the electrostatic latent image developing toner, if the amount of the colorant is too large, the fixability of the toner is lowered, while if the amount of the colorant is too small. Since the desired image density cannot be obtained, the amount of the colorant is 1 to 20 parts by weight, preferably 2 to 10 parts by weight, based on 100 parts by weight of the above resin in the electrostatic latent image developing toner. It is preferable to do so.

When the charge control agent is added to the electrostatic latent image developing toner according to the present invention, the positive charge control agent may be, for example, an azine compound nigrosine base E.
X, Bontron N-01, 02, 04, 05, 07, 0
9, 10, 13 (manufactured by Orient Chemical Industry Co., Ltd.), oil black (manufactured by Chuo Synthetic Chemical Industry Co., Ltd.), quaternary ammonium salt P
-51, polyamine compound P-52, Sudan Chief Schwarz BB (solvent black 3: CI No.
26150), Fetschwartz HBN (C.I.N.
o. 26150), Brilliant Spirits Schwarz TN (manufactured by Farbenfabrikken Bayer), and further alkoxylated amines, alkylamides, molybdic acid chelate pigments, imidazole compounds and the like can be used. , Chromium complex salt type azo dyes S-32, 33, 34, 35, 37, 38,
40,44 (manufactured by Orient Chemical Industry Co., Ltd.), Aizen Spiro 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 added to the electrostatic latent image developing toner, the amount of the charge control agent added depends on the type of toner, the type of additive to be added to the toner, and the production of toner particles. It should be appropriately selected depending on the type of the resin and the developing system (two-component system or one-component system) in which development is performed using the electrostatic latent image developing toner.

If the amount of the charge control agent added to the electrostatic latent image developing toner is too large, the chargeability of the obtained electrostatic latent image developing toner becomes unstable and the electrostatic latent image developing toner becomes unstable. While the fixability of the image developing toner is lowered, if the amount of the charge control agent is too small, the desired charge amount cannot be obtained.

Therefore, when the charge control agent as described above is contained in the toner particles produced by the kneading-pulverization method, the suspension method or the like, it is added to 100 parts by weight of the resin used for the toner particles. The charge control agent is 0.1 to 20
Parts by weight, preferably 1 to 10 parts by weight are added. Further, when the charge control agent is adhered to the surface of the toner particles to be fixed, if the amount of the charge control agent is large, the adhesion of the charge control agent to the surface of the toner particles becomes insufficient, resulting in this electrostatic latent image. When the developing toner is used, the problem that the charge control agent is released from the surface of the toner particles occurs, so 0.001 of the charge control agent is added to 100 parts by weight of the toner particles.
-10 parts by weight, preferably 0.05 to 2 parts by weight, and more preferably 0.1 to 1 part by weight.

When an offset preventing agent is added to the toner for developing an electrostatic latent image according to the present invention, various waxes, particularly low molecular weight polypropylene, polyethylene, or oxidized polypropylene are used as the offset preventing agent. Polyolefin wax such as polyethylene is preferably used.

On the other hand, as the fluidizing agent which is mixed with the toner particles and adhered to the surface of the toner particles, a known material which has been conventionally used to impart fluidity to the toner can be used. For example, silica, aluminum oxide, titanium oxide, magnesium fluoride, zirconium oxide, fluorine-based resin fine particles, acrylic resin fine particles, etc. can be used, and these can be used alone or in combination. ..

When such a fluidizing agent is mixed with the above-mentioned toner particles and the fluidizing agent is attached to the surface of the toner particles, the number average particle diameter D of the fluidizing agent attached to the surface of the toner particles is _N is 0.005 μm ≦ D _N ≦ 0.5
1 and 2 are used as a mixing device for mixing 5 μm of the fluidizing agent having a particle diameter of μm and having a particle diameter of 3 times or more of the number average particle diameter D _N so as to be 5% by number. A mixing device as shown can be preferably used.

Here, in the mixing apparatus shown in FIG.
The lower portion of the processing chamber 10 for mixing the toner particles and the fluidizing agent is formed in a hemispherical shape, while the upper portion thereof is formed in a cylindrical shape.

When the fluidizing agent is mixed with the toner particles in the processing chamber 10, a rotating shaft 21 having a plurality of stirring blades 22 is used as a stirring means 20 for mixing and stirring the fluidizing agents. I did it.

Here, in the stirring means 20, the rotary shaft 21 is provided at the rotary shaft 21 so as to extend into the process chamber 10 by inclining the rotary shaft 21 from a lower part of the process chamber 10 which is hemispherical by a predetermined angle. Further, the stirring blade 22 is tilted at a required angle in the processing chamber 10.

Then, the rotating shaft 21 is rotated by the motor 23 via the belt 24 and the pulley 25, whereby the stirring blades 22 are rotated in the processing chamber 10 in a tilted state at a required angle, and thus rotated. The stirring blade 22 was used to mix the fluidizing agent with the toner particles in the processing chamber 10.

In this mixing device, the stirring means 20 is used as the adhesion suppressing means 30 for suppressing the adhesion of the fluidizing agent and the toner particles to the inner wall 11 of the processing chamber 10.
The first scraping member 31 having an arc shape corresponding to the inner shape of the lower portion of the processing chamber 10 is attached to the cylindrical rotating shaft 31a through which the rotating shaft 21 of FIG. Is closely contacted with the inner wall 11 of the lower part of the processing chamber 10, and the processing chamber 10 is inserted from the upper part of the processing chamber 10.
A second scraping member 3 having a groove shape corresponding to the internal shape of the upper portion of the processing chamber 10 is attached to the rotating shaft 32a extending inward.
2 was attached so that the second scraping member 32 was brought into close contact with the inner wall 11 above the processing 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 processing 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 portion of the processing chamber 10 to rotate, and The fluidizing agent and the toner particles attached to the lower and upper inner walls 11 are scraped off from the inner wall 11 of the processing chamber 10 by the first and second scraping members 31 and 32.

In this mixing device, the fluidizing agent and the toner particles adhering to the inner wall 11 at the lower and upper portions of the processing chamber 10 as described above are removed by the first and second scraping members 3 respectively.
When the fluidizing agent is mixed with the toner particles by the agitating blades 22 of the agitating means 20 while being scraped off by 1, 32, the fluidizing agent is not adhered to the inner wall 11 of the processing chamber 10 and solidified, and fluidized. The agent is crushed into the state of primary particles and mixed with the toner particles in a sufficiently dispersed state, so that the fluidizing agent is uniformly dispersed and attached in the state of primary particles on the surface of the toner particles. And the number average particle diameter D _{N of} the fluidizing agent attached to the surface of the toner particles is 0.0
In 05μm ≦ D _N ≦ 0.5μm, the number average particle diameter D electrostatic latent image developing toner that fluidizer became 5% by number or less having a particle size of more than 3 times the _N can be easily obtained and Like

In this mixing apparatus, since the stirring blade 22 is rotated in the processing chamber 10 in a state in which it is inclined at a required angle as described above, the stirring blade 22 causes the fluidizing agent to become the toner particles. The stress applied to these particles during mixing and stirring was also reduced.

The mixing device shown in FIG. 2 is also the same as that shown in FIG.
Although it is substantially the same as the mixing device shown in FIG. 2, in this mixing device, the processing chamber 10 for mixing the fluidizing agent with the toner particles is formed into a spherical shape, and the processing chamber 10 itself can be freely tilted. .. Then, the inner wall 11 of the processing chamber 10
As the adhesion suppressing means 30 for suppressing the adhesion of the fluidizing agent and the toner particles to the inside, a cylindrical rotating shaft 33a through which the rotating shaft 21 of the stirring means 20 is inserted corresponds to the internal shape of the processing chamber 10. Ring-shaped scraping member 33
Was attached, and the scraping member 33 was brought into close contact with the inner wall 11 of the processing chamber 10.

Also in this mixing device, the rotating 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 processing chamber 10. The fluidizing agent and the toner particles adhering to the inner wall 11 of the processing chamber 10 are scraped off by the scraping member 33 by rotating in close contact with the processing chamber 11.

When the toner particles and the fluidizing agent are mixed by using the mixing devices shown in FIGS. 1 and 2 and the fluidizing agent is adhered to the surface of the toner particles, the processing chamber 10 is generally used. Temperature of 5 to 60 ° C, mixing time of 30
The peripheral speed of the tip of each stirring blade 22 is set to 10 to 10 seconds.
It is preferable to set it in the range of 80 m / sec.

In the mixing devices shown in FIGS. 1 and 2, the fluidizing agent and the toner particles are used as the inner wall 11 of the processing chamber 10.
Although the scraping members 31, 32, and 33 as described above are provided as the adhesion suppressing means 30 for suppressing adhesion to the surface, the adhesion suppressing means 30 is not particularly limited to the above. For example, an ultrasonic vibration machine or the like that vibrates the inner wall 11 of the processing chamber 10 and suppresses the fluidizing agent and the toner particles from adhering to the inner wall 11 of the processing chamber 10 is used as the adhesion suppressing unit 30. Is also possible. Further, the operating conditions of the scraping members 31, 32, 33 are appropriately set according to the types and amounts of the fluidizing agent and the toner particles so that the fluidizing agent and the toner particles do not adhere to the inner wall 11 of the processing chamber 10. Must be set.

When the electrostatic latent image developing toner according to the present invention is used in the two-component developing system, the electrostatic latent image developing toner is mixed with the magnetic carrier. Here, as the magnetic carrier to be mixed with the toner for developing the electrostatic latent image, a known magnetic carrier generally used conventionally can be used, for example, iron,
Alloys or mixtures of metals such as nickel and cobalt with metals such as zinc, antimony, aluminum, lead, tin, bismuth, beryllium, manganese, selenium, tungsten, zirconium, vanadium, oxides, titanium oxide, magnesium oxide, etc. Mixtures of metal oxides, chromium nitride, vanadium nitride, etc., with carbides such as silicon carbide, tungsten carbide, etc., ferromagnetic ferrites, and iron, ferrite carriers, etc. composed of materials such as these mixtures can be used.

Further, as the above-mentioned magnetic carrier, a core material of iron or ferrite carrier, the surface of which is coated with various synthetic resins or ceramic layers can be used. Here, as the above-mentioned synthetic resin for coating the core material, for example, polystyrene resin, poly (meth) acrylic resin, polyolefin resin, polyamide resin,
Various thermoplastics such as polycarbonate resin, polyether resin, polysulfinic acid resin, polyester resin, epoxy resin, polybutyral resin, urea resin, urethane / urea resin, silicone resin, polyethylene resin, Teflon resin, etc. Resins and thermosetting resins and mixtures thereof, copolymers of these resins, block polymers,
Graft polymers and polymer blends can be used, and in addition, resins having various polar groups may be used in order to improve the chargeability thereof. On the other hand, when coating the surface of the core material with the ceramic layer, various ceramic materials are coated on the surface of the core material by a method such as a thermal spraying method, various plasma methods, and a sol-gel method.

Further, as the magnetic carrier, the above-mentioned various synthetic resins used for coating are used as a binder resin, and the above-mentioned various magnetic materials and, if necessary, various organic and / or inorganic materials are added. It is also possible to mix, knead, and grind, and use a binder-type carrier whose particle size is adjusted as necessary.

In each of the above magnetic carriers used in the present invention, if the particle size is smaller than 20 μm, there is a problem that the magnetic carrier itself is generally attached to the photosensitive member and developed. , The particle size is 2
If it is larger than 00 μm, there is a problem that the texture of an image to be formed is generally rough. Therefore, normally, an average particle size of 20 to 200 μm, preferably 30 to 100 μm is used, and a developing method or the like is used. Therefore, a magnetic carrier having an appropriate particle size is appropriately selected and used.

[0050]

In the toner for developing an electrostatic latent image according to the present invention, at least the toner particles containing the thermoplastic resin as a main component and the fluidizing agent are mixed to adhere the fluidizing agent to the surface of the toner particles. The number average particle diameter D _{N of} the fluidizing agent attached to the surface of the toner particles is 0.005 μm ≦
Since D _N ≦ 0.5 μm and the number of fluidizing agents having a particle diameter of 3 times or more of the number average particle diameter D _N is set to 5% or less, most of the fluidizing agent is in the state of primary particles. The toner for electrostatic latent image development is obtained by being crushed into particles and attached to the surface of the toner particles in a state of being uniformly dispersed, and having excellent fluidity and less variation in characteristics such as charging property.

When the electrostatic latent image developing toner is used to form an image, the fluidity of the electrostatic latent image developing toner is improved and the charging property and other characteristics are stabilized. In addition, high quality images can be stably obtained.

[0052]

[Examples] A specific example of the production of a toner for developing an electrostatic latent image in which toner particles and a fluidizing agent are mixed and the fluidizing agent is attached to the surface of the toner particles will be described below. The electrostatic latent image developing toner manufactured in accordance with the present invention includes the electrostatic latent image developing toner satisfying the conditions defined in the present invention and the electrostatic latent image developing toner not satisfying the conditions defined in the invention. Comparison with a toner reveals that the toner for developing an electrostatic latent image satisfying the above conditions defined in the present invention is excellent.

Here, in producing each electrostatic latent image developing toner, four types of toner particles a to d produced as described below were used.

(Production of Toner Particles a) To produce the toner particles a, 70 parts by weight of styrene, 28 parts by weight of n-butyl methacrylate, 2 parts by weight of methacrylic acid and 2,2-azobis- (2,2). 0.5 parts by weight of 4-dimethylvaleronitrile) (Wako Pure Chemical Industries, Ltd., first grade), 8 parts by weight of carbon black (Mitsubishi Kasei Kogyo, MA # 8), and chromium complex salt (Orient Chemical Co., Ltd.) , E-8
1) 3 parts by weight were mixed with a sand stirrer to prepare a polymerization composition.

Then, this polymer composition was stirred in an aqueous solution of gum arabic with a concentration of 3% (T.
K. Rotation speed 4000 rp using auto homomixer)
Polymerization reaction at a temperature of 60 ° C. for 6 hours while stirring at m
Further, the temperature was raised to 90 ° C. to cause a polymerization reaction. Then, after the completion of the polymerization reaction, the reaction system was cooled, washed with water 5 times, filtered, and dried to obtain spherical particles.

The spherical particles thus obtained were further classified by air to produce black toner particles having an average particle size of 8 μm.

(Production of Toner Particles b) In producing the toner particles b, a quaternary ammonium salt (P-51 manufactured by Orient Chemical Industry Co., Ltd.) is used instead of the chromium complex salt used in the production of the toner particles a. Was added in the same manner as in the case of the toner particles a, and black toner particles having an average particle diameter of 8 μm were obtained.

(Production of Toner Particles c) To produce the toner particles c, 100 parts by weight of a polyester resin (Tafton NE-1110 manufactured by Kao Corporation) and carbon black (MA # 8 manufactured by Mitsubishi Kasei Kogyo Co., Ltd.) 8 Parts by weight and low molecular weight polypropylene (Viscole 6 manufactured by Sanyo Kasei Co., Ltd.)
05P) and 3 parts by weight of a chromium complex salt type azo dye (S-34, manufactured by Orient Chemical Industry Co., Ltd.) were thoroughly mixed by a ball mill and then kneaded by a three-roll mill heated to 140 ° C.

Then, the kneaded material thus obtained is allowed to cool and then coarsely pulverized using a feather mill,
Further, it was finely pulverized with a jet mill, and the finely pulverized material was subjected to air classification to obtain black toner particles having an average particle diameter of 9 μm.

(Production of Toner Particles d) To produce the toner particles d, a styrene-methyl methacrylate resin (softening point: 138 ° C., glass transition point: 65 ° C.) 10
0 parts by weight, 5 parts by weight of a blue pigment (phthalocyanine blue), and 5 parts by weight of a quaternary ammonium salt (P-51, manufactured by Orient Chemical Industry Co., Ltd.) were used. By the same method as in the above, blue toner particles having an average particle diameter of 9 μm were obtained.

Next, the above-mentioned four types of toner particles a to d are used as the toner particles, while colloidal silica having an average particle diameter of 0.02 μm (HDK H-2000 manufactured by Wacker) is used as the fluidizing agent. Experimental Examples 1 to 1 below
Eight types of toners for developing electrostatic latent images were manufactured as shown in FIG.

(Experimental Example 1) In this experimental example, 0.3 part by weight of the colloidal silica is added to 100 parts by weight of the toner particles a, and these are mixed and stirred by the mixing apparatus shown in FIG. Then, a fluidizing agent, colloidal silica, is adhered to the surface of the toner particles a to produce a toner for developing an electrostatic latent image.

Here, when the toner particles a and the colloidal silica are mixed and stirred by the mixing device shown in FIG. 1, the circumference of the tip portion of the stirring blade 22 having the longest blade among the stirring blades 22. The stirring blades 22 are rotated by the rotating shaft 21 at a speed of 60 m / sec, and the first and second scraping members 31, 32 are moved with respect to the rotation direction of the stirring blades 22. The scraping members 31 and 32 are rotated at appropriate rotational speeds by performing normal rotation and reversal every 10 seconds to prevent the colloidal silica or the like from adhering to and agglomerating on the inner wall 11 of the processing chamber 20. While preventing, each stirring blade 22 described above
Thus, the toner particles a and colloidal silica are mixed and stirred to adhere the fluidizing agent colloidal silica to the surface of the toner particles a.

Here, in the electrostatic latent image developing toner thus manufactured, the state of the colloidal silica adhering to the surface of the toner particles a was examined. As shown in the electron micrograph of FIG. Silica in the state of fine primary particles was uniformly dispersed and adhered to the surface of the toner particle a.

(Experimental Example 2) In this experimental example, the toner particles b are used as the toner particles, and otherwise the electrostatic latent image developing toner is prepared in the same manner as in the experimental example 1. Manufactured.

(Experimental Example 3) In this experimental example, the above-mentioned toner particles c are used as the toner particles, and when the toner particles c and the colloidal silica are mixed and stirred, the above-mentioned FIG. 2 is used. The indicated mixing device was used.

Then, in the mixing device shown in FIG. 2, the toner particles c and colloidal silica are mixed and stirred under the same conditions as in the case of Experimental Example 1, and the surface of the toner particles c is coated with the fluidizing agent. A toner for developing an electrostatic latent image was manufactured by depositing colloidal silica.

(Experimental Example 4) In this experimental example, the toner particles d are used as the toner particles, and otherwise the electrostatic latent image developing toner is used in the same manner as in the experimental example 3. Manufactured.

(Experimental Example 5) In this experimental example, the same toner particles a as in Experimental Example 1 were used as the toner particles,
To 100 parts by weight of this toner particle a, 0.2 parts by weight of the above colloidal silica was added. And
When the toner particles a and colloidal silica are mixed and stirred, a homogenizer (manufactured by Nippon Seiki Co., Ltd.) is used, and the peripheral speed is 50 m / sec, and these are mixed and stirred for 1 minute to fluidize to the surface of the toner particles a. Toner for developing an electrostatic latent image was produced by adhering the agent colloidal silica.

When the state of the colloidal silica adhering to the surface of the toner particles a in the electrostatic latent image developing toner thus manufactured is examined, as shown in the electron micrograph of FIG. 4, the colloidal silica aggregates. In the state of large particles, the toner particles a were unevenly attached to the surface.

(Experimental Example 6) In this Experimental Example, the same toner particles b as those in Experimental Example 2 are used as toner particles, and otherwise the electrostatic latent image is the same as in Experimental Example 5 above. A developing toner was produced.

(Experimental Example 7) In this Experimental Example, the same toner particles c as those in Experimental Example 3 were used as the toner particles.
0.3 part by weight of the above colloidal silica was added to 100 parts by weight of the toner particles c. And
When the toner particles c and colloidal silica are mixed and stirred, a Henschel mixer (manufactured by Mitsui Miike Kakoki Co., Ltd.) is used, and the peripheral speed is 50 m / sec. A fluidizing agent, colloidal silica, was attached to the toner to prepare a toner for developing an electrostatic latent image.

(Experimental Example 8) In this experimental example, the same toner particles d as those in Experimental Example 4 are used as toner particles, and otherwise the electrostatic latent image is the same as in Experimental Example 7. A developing toner was produced.

The average particle size of each of the toner particles a to d used in these Experimental Examples 1 to 8 is the laser diffraction type particle size distribution measuring device (Shimadzu Corporation, SALD-110).
0), and the average particle size of the colloidal silica used as a fluidizing agent was measured by using a flow type specific surface area measuring device (manufactured by Shimadzu Corporation, Flowsorb 2300). The value was converted into a particle size and determined.

Then, with respect to each of the electrostatic latent image developing toners of Experimental Examples 1 to 8 produced as described above, the state in which the fluidizing agent colloidal silica adhered to the surface of each of the toner particles a to d was examined, The number average particle diameter D _{N of} colloidal silica adhering to the surface of each toner particle a to d and the number% to which a fluidizing agent having a particle diameter of 3 times or more the number average particle diameter D _N adheres In order to determine the fluidity of each electrostatic latent image developing toner of Experimental Examples 1 to 8, the bulk density of each electrostatic latent image developing toner was measured, and the results are shown in Table 1 below. ..

The number average particle diameter D _{N of} the colloidal silica attached to the surface of the toner particles and the number average particle diameter D
_In order to determine the number% in which the fluidizing agent having a particle diameter of 3 times or more of _N is attached, each electrostatic latent image developing toner of Experimental Examples 1 to 8 is photographed using a scanning electron microscope. 100 particles of the colloidal silica adhering to the surface of each toner particle are randomly selected, the particle diameter of each colloidal silica is measured, and the number average particle diameter D _N of the colloidal silica is determined based on the measurement result. Further, the number% of colloidal silica particles having a particle diameter of 3 times or more of the number average particle diameter D _N thus obtained was obtained. The bulk density of each electrostatic latent image developing toner of Experimental Examples 1 to 8 was measured by using Tapdenser KYT-2000 (manufactured by Seishin Enterprise Co., Ltd.).

[0077]

[Table 1]

As a result, the electrostatic latent image developing toners of Experimental Examples 1 to 4 in which the toner particles a to d and the colloidal silica were mixed and agitated by using the mixing device of FIGS. 1 and 2 were fluidized. The number average particle diameter D _{N of the} agent is 0.005 μm ≦ D _N ≦
The condition of the present invention that the number of the fluidizing agent having a particle size of 0.5 μm and 3 times or more of the number average particle size D _N is 5% or less is satisfied, but the toner is obtained by using a homogenizer or a Henschel mixer. The electrostatic latent image developing toners of Experimental Examples 5 to 8 in which the particles a to d and the colloidal silica were mixed and stirred did not satisfy the above conditions of the present invention.

Then, in terms of the bulk density measured for examining the fluidity of the toner for developing the electrostatic latent image, Experimental Examples 1 to
4 is compared with the electrostatic latent image developing toners of Experimental Examples 5 to 8, the electrostatic latent images of Experimental Examples 1 to 4 satisfying the conditions of the present invention. The developing toner had a larger bulk density and superior fluidity as compared with the electrostatic latent image developing toners of Experimental Examples 5 to 8 which did not satisfy the conditions of the present invention.

Next, Experimental Example 1 manufactured as described above
.About.8 for each of the electrostatic latent image developing toners, the average charge amount [μC / g], the defective charge toner amount [wt%],
The amount of scattered toner was measured.

Here, in carrying out these measurements for each of the electrostatic latent image developing toners of Experimental Examples 1 to 8, each electrostatic latent image developing toner was prepared by using the binder type carrier produced as follows. It was mixed with and evaluated.

Here, in manufacturing the binder type carrier, polyester resin (NE-, manufactured by Kao Corporation) is used.
1110) 100 parts by weight, inorganic fine particles (manufactured by Toda Kogyo Co., EPT-1000) 500 parts by weight, and carbon black (Mitsubishi Kasei Co., MA # 8) 2 parts by weight were sufficiently mixed by a Henschel mixer and pulverized. After that, these were melt-kneaded by using an extrusion kneader set to a cylinder portion of 180 ° C. and a cylinder head portion of 170 ° C. The kneaded product was cooled, coarsely pulverized with a feather mill, finely pulverized with a jet mill, and further classified with an air classifier to obtain a binder type carrier having an average particle diameter of 55 μm.

The average particle size of this binder type carrier is the same as when the average particle size of each of the toner particles a to d is obtained, a laser diffraction type particle size distribution measuring device (Shimadzu SALD-1100). Was measured.

When measuring the average charge amount and the poorly charged toner amount of each electrostatic latent image developing toner of Experimental Examples 1 to 8 using the above binder type carrier, each electrostatic latent image developing toner was measured. 28 g of the above carrier is added to each 2 g of toner, and 50 g of each of them is added.
Put in a plastic bottle of c, and rotate at 120 rpm on a rotating rack for 3
The thing rotated for 10 minutes and the thing rotated for 10 minutes were prepared.

Next, 3 g of the developer containing each electrostatic latent image developing toner thus rotated and adjusted is weighed by a precision balance, and each electrostatic latent image developing toner is measured using the apparatus shown in FIG. The average amount of electrostatic charge and the amount of poorly charged toner were measured.

Here, in measuring the average amount of charge and the amount of poorly charged toner of each toner using the apparatus shown in FIG. 5, each developer measured as described above is applied to the entire surface of the conductive sleeve 1. The magnet roll 2 was placed evenly, and the magnet roll 2 provided in the conductive sleeve 1 was rotated at 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 is measured by a precision balance to obtain the average charge amount [μC / g] of each electrostatic latent image developing toner, and the result is shown below. Table 2 below.

Further, the results of the above measurements are totaled to obtain the charge amount distribution of each electrostatic latent image developing toner contained in the developer, and the average charge amount of each electrostatic latent image developing toner [ The amount of toner whose charge amount became 1/5 or less with respect to μC / g] was determined based on this charge amount distribution, and the value is shown in Table 2 below as a poorly charged toner amount [% by weight]. ..

When investigating the amount of scattering in each electrostatic latent image developing toner of Experimental Examples 1 to 8, Experimental Examples 1 to 1 were carried out in the same manner as in the case of measuring the above-mentioned average charge amount [μC / g]. A developer containing each of the electrostatic latent image developing toners of No. 8 was prepared.

To check the amount of scattering in each electrostatic latent image developing toner, the digital dust meter P5H2 is used.
Using a mold (manufactured by Shibata Chemical Co., Ltd.), the dust meter is set at a position 10 cm away from the magnet roll, and 2 g of the developer containing each toner adjusted as described above is set on the magnet roll. The amount of each toner that generated dust when the magnet roll was rotated at 2000 rpm was read by the above dust meter, and the count number per minute [cpm] was obtained.

Then, when the count number per minute thus obtained is 100 cpm or less, it is ◯, and 300 cp
Table 2 below shows Δ when m or less and X when more than 300 cpm.

[0092]

[Table 2]

As is clear from these results, the electrostatic latent image developing toners of Experimental Examples 1 to 4 satisfying the conditions of the present invention and the same toner particles as these electrostatic latent image developing toners were used. , Experimental Example 5 that does not satisfy the conditions of the present invention
8 is compared with each electrostatic latent image developing toner, the electrostatic latent image developing toners of Experimental Examples 1 to 4 satisfying the condition of the present invention do not satisfy the condition of the present invention. Compared with the electrostatic latent image developing toners of Experimental Examples 5 to 8, the charge amount of the toner quickly rises to a predetermined charge amount, and the amount of defectively charged toner is reduced, and the amount of scattered toner is further increased. Was also less.

Further, in each of the electrostatic latent image developing toners of Experimental Examples 1 to 4 satisfying the conditions of the present invention as described above, the charge amount of the toner quickly rises to a predetermined charge amount, and the toner having a bad charge is obtained. Is small and the amount of scattered toner is also small. Therefore, when an image is formed using each of the electrostatic latent image developing toners of Experimental Examples 1 to 4, a good image without fogging is stably obtained. Was obtained.

[0095]

As described in detail above, in the toner for developing an electrostatic latent image according to the present invention, the fluidizing agent is prepared by mixing at least toner particles containing a thermoplastic resin as a main component with the fluidizing agent. When the number average particle size D _{N of} the fluidizing agent attached to the surface of the toner particles is 0.005 μm ≦ D _N ≦ 0.5 μm,
In addition, since the fluidizing agent having a particle diameter of 3 times or more the number average particle diameter D _N is set to 5 number% or less, the fluidizing agent is aggregated as in the conventional electrostatic latent image developing toner. In the state where most of the fluidizing agent is disintegrated into primary particles without unevenly adhering to the surface of the toner particles.
It has become possible to obtain a toner for developing an electrostatic latent image, which is adhered to the surface of toner particles in a state of being uniformly dispersed, has excellent fluidity, and has little variation in characteristics such as chargeability.

When an image is formed using the toner for developing an electrostatic latent image according to the present invention, the toner for developing an electrostatic latent image according to the present invention has excellent fluidity as described above and also has a charging property. Since there is little variation in characteristics such as properties, it has become possible to stably obtain a good image as compared with the case where an image is formed using a conventional toner for developing an electrostatic latent image.

[Brief description of drawings]

FIG. 1 is an example of a mixing device used for adhering the fluidizing agent to the surface of the toner particles by mixing and stirring the toner particles and the fluidizing agent in the electrostatic latent image developing toner according to the present invention. It is the schematic explanatory drawing shown.

FIG. 2 is an electrostatic latent image developing toner according to the present invention, in which another mixing device used for adhering the fluidizing agent to the surfaces of the toner particles by mixing and stirring the toner particles and the fluidizing agent. It is the schematic explanatory drawing which showed the example.

3 is a photograph replacing a drawing showing a particle structure of a toner for developing an electrostatic latent image in Experimental Example 1. FIG.

FIG. 4 is a photograph replacing a drawing showing a particle structure of a toner for developing an electrostatic latent image in Experimental Example 5.

FIG. 5 is a schematic diagram of an apparatus used to measure the average charge amount of toner and the amount of poorly charged toner.

Claims (1)

[Claims] 1. A toner for developing an electrostatic latent image, comprising a mixture of toner particles containing at least a thermoplastic resin as a main component and a fluidizing agent, the fluidizing agent being attached to the surface of the toner particles. The number average particle size D _{N of} the fluidizing agent attached to the surface is 0.005 μm ≦ D _N ≦ 0.5 μm, and the fluidizing agent having a particle size three times or more of the number average particle size D _N is A toner for developing an electrostatic latent image, which is 5% by number or less.