JP2003223019A - Solid toner and image forming method and device using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid toner which is surely ground within a device and of which only the single particles of the toner are supplied to a developing portion and, an image forming method and device using the same. <P>SOLUTION: The polymerized toner manufactured by a method of making raw materials particulate in a dispersion system, such as a suspension polymerization method, emulsion polymerization method and emulsion dispersion method, is molded to obtain the solid toner. The spheroidized toner undergoing spheroidization processing by heating is otherwise solidified, to obtain the solid toner. The shape of the toner particles is consequently spherical. The handling quality in replenishing of a toner bottle with the toner, etc., is therefore good and the toner has an excellent break up property. Since image formation is performed only with the toner surely pulverized to the single particles, a clogging with the toner and the deterioration in image quality do not occur. The surfaces of the toner particles are covered with particulates before the solidification of the toner, thereby, the break up property of the solid toners is further well assured. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used as a developer during image formation. More specifically, the present invention relates to a solid toner molded into a predetermined shape, and an image forming method and apparatus using the solid toner.

[0002]

2. Description of the Related Art In an image forming apparatus using toner, it is necessary to replenish toner, which is a consumable item, as appropriate. During this replenishment work, toner dust may be scattered and contaminate your hands or the area around the replenishment port. In order to prevent this, there is a demand for using solidified toner. The prior art which uses the toner of the molded body for such requirements is as follows.
There are various types such as those disclosed in Japanese Patent Application Laid-Open No. 9-127778. Among them, as in Japanese Patent Laid-Open No. 6-308811, there is one in which a cylindrical solid toner is used as it is as a developing roller or a supplying roller.

[0003]

However, the above-mentioned conventional techniques have the following problems. That is, the solid toner must be provided for development in a state of being surely crushed. Otherwise, a toner lump in which a plurality of toner particles are aggregated is supplied to the developing area. This causes image noise and clogging. There are conventional technologies that take this into consideration, but they are still insufficient and have not reached the stage of practical application.

The present invention has been made to solve the problems of the above-described conventional solid toner. That is, it is an object of the invention to provide a solid toner which is surely pulverized in the apparatus and only the single particles of the toner are supplied to the developing portion, and an image forming method and apparatus using the solid toner.

[0005]

The solid toner of the present invention made for the purpose of solving this problem is a molded body of polymerized toner particles obtained by granulating raw materials in a dispersion system. Alternatively, it is a molded body of spheronized toner particles that have been spheronized by heating. As a result of studies by the present inventors, it has been found that the shape of toner particles is a factor that hinders the pulverization of solid toner. If the toner particles have a rough and irregular shape, it is difficult for the particles to come apart. Therefore, the present invention is to obtain a solid toner by using a spherical toner having as few corners as possible. That is, among the toners, the polymerized toner that is made into particles in the dispersion system has a relatively good spherical shape. Therefore, the solid toner obtained by solidifying the polymerized toner has excellent divergence. In particular, the toner produced by the suspension polymerization method is preferable because of its high sphericity.
The polymerized toner referred to in the present invention includes those manufactured by the suspension polymerization method or the emulsion polymerization method as well as those manufactured by the emulsion dispersion method. Further, even a toner manufactured by another method such as a pulverization method can be made into a sphere by once being heated and softened. Therefore, the solid toner obtained by solidifying the spheroidized toner that has been spheronized by heating is also excellent in divergence.

In the solid toner of the present invention, it is further preferable that the toner particles have been subjected to a treatment of coating the surface with fine particles before molding. In this way, the fine particles prevent the toner particles from sticking to each other. Therefore, the toner particles are easily separated from each other during the pulverization. From this, it is desirable that the fine particles contain a polymer having a glass transition point higher than that of the polymer constituting the toner particles as a main component.

According to the image forming method of the present invention, however, solid toner, which is a molded product of polymerized toner or spheroidized toner, is held in the apparatus, the solid toner is crushed in the apparatus to obtain toner particles, and the toner particles are obtained. Is a method for forming an image using a solid toner for developing a latent image. Further, the image forming apparatus of the present invention is an image forming apparatus that develops a latent image by supplying toner to an image carrier, and a toner roller formed by polymerizing toner or spherical toner into a cylindrical shape is a toner supply source. It has a supply roller in contact with the toner roller and supplies toner from the toner roller to the supply roller at the nip portion between the toner roller and the supply roller. As a result, both convenience of storage and replenishment work of toner and high-quality image formation with toner that has been reliably separated are compatible.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments embodying the present invention will be described in detail below with reference to the accompanying drawings.

[Toner Particles] First, the toner particles will be described. In the present invention, both polymerized toner and pulverized toner can be used. Further, the polymerized toner may be prepared by any of the suspension polymerization method, the emulsion polymerization method and the emulsion dispersion method. However, the pulverized toner needs to be spheronized by heating to be spheronized. Hereinafter, each manufacturing method will be briefly described.

(Suspension Polymerization Method) The suspension polymerization method is outlined in FIG.
The toner is manufactured by the procedure shown in. That is, in the suspension polymerization method, the raw material in a monomer state is dispersed in water as a dispersion medium.
At this time, a colorant, a polymerization initiator and other additives are mixed with the monomer forming the oil phase. Then, it is polymerized by polymerization. Then, it is washed, coated with fine particles, and dried. As a result, toner particles which are substantially spherical and whose surface is coated with fine particles are obtained.

Here, the polymerizable monomer as a raw material includes styrene compounds, unsaturated carboxylic acids, unsaturated carboxylic acid esters, unsaturated carboxylic acid derivatives,
Ethylenically unsaturated mono-olefin, vinyl halide,
Monovinyl type monomers such as vinyl ester, vinyl ether, vinyl ketone type compounds, nitrogen-containing vinyl, etc., acrylic acid ester type monomers, methacrylic acid ester type monomers, etc. can be used. You may use these 2 or more types in mixture. Further, for example, a crosslinkable monomer such as an aromatic divinyl compound may be blended.

As the colorant, for black, there are carbon black and magnetic particles (ferric tetroxide, etc.), for yellow and magenta, there are azo pigments and condensed polycyclic pigments, and for cyan. Include copper phthalocyanine compounds and anthraquinone compounds.

As the polymerization initiator, persulfates (potassium persulfate, etc.) and azo compounds (2,2'-azobis-2-methyl-N-1,1'-bis (hydroxymethyl) -2-) are used.
Hydroxyethyl propioamide etc.), peroxides (methyl ethyl peroxide etc.) etc. can be used. A polymerization initiator may be used in combination with a reducing agent as a redox type initiator.

Examples of other additives include a charge control agent using a metal complex of an organic compound, or a releasing agent.

As the dispersant, sulfates (barium sulfate etc.), carbonates (magnesium carbonate etc.), phosphates (calcium phosphate etc.), metal oxides (titanium oxide etc.), metal hydroxides (aluminum hydroxide etc.). ), Etc., solid fine powders can be used. Alternatively, water-soluble polymers (polyvinyl alcohol, etc.) and various surfactants can be used.

(Emulsion Polymerization Method) The emulsion polymerization method is outlined in FIG.
The toner is manufactured by the procedure shown in. That is, in the emulsion polymerization method, the raw materials in a monomer state are dispersed together with the polymerization initiator in water as a dispersion medium. At this time, the coloring agent is not mixed. This forms fine polymer particles. Then, add the colorant together with the coagulant and other additives,
The polymer particles are agglomerated with the colorant. Then, it is washed, coated with fine particles, and dried. As a result, toner particles which are substantially spherical and whose surface is coated with fine particles are obtained.

As the raw material monomers, those listed in the suspension polymerization method can be used. The same applies to colorants, polymerization initiators, and other additives.

Examples of emulsifiers include ionic surfactants such as sulfonates (sodium dodecylbenzene sulfonate, etc.), sulfate ester salts (sodium octyl sulfate, etc.), fatty acid salts (potassium stearate, etc.), polyethylene oxide, Nonionic surfactants such as polypropylene oxide, esters of polyethylene glycol and higher fatty acids, etc. can be used.

As the coagulant, alkali metal salts or alkaline earth metal salts (both halogen salts or carbonates,
Sulfate, etc.) can be used.

(Emulsification and Dispersion Method) An outline of the emulsification and dispersion method is shown in FIG.
The toner is manufactured by the procedure shown in. That is, in the emulsification dispersion method, a raw material in the form of a polymer is dissolved in a water-insoluble organic solvent and dispersed in water as a dispersion medium together with a coloring agent or other additives. As a result, polymer particles containing the organic solvent are formed. After this is dissolved, it is washed, coated with fine particles, and dried. As a result, toner particles which are substantially spherical and whose surface is coated with fine particles are obtained.

As the raw material polymer, a polymer that is soluble in a water-insoluble organic solvent and is insoluble in water or almost insoluble in water can be used. For example, styrene resin, acrylic resin, methacrylic resin, styrene-acrylic copolymer resin, styrene-methacrylic copolymer resin, polyester resin, polyamide resin, carbonate resin, polyether, polyvinyl acetate resin,
Polysulfone, epoxy resin, polyurethane resin, urea resin, etc. can be used. You may use these 2 or more types in mixture.

As the water-insoluble organic solvent, those which are insoluble or sparingly soluble in water and which dissolve the above-mentioned polymer can be used. For example, toluene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, trichloroethylene, chloroform, ethyl acetate, methyl ethyl ketone, etc. can be used.

As the colorant, those listed in the suspension polymerization method can be used. Examples of other additives include a charge control agent and a release agent.

As the dispersant, gelatin, gum arabic, agar, cellulose derivatives (hydroxymethyl cellulose etc.) and water-soluble polymers (polyvinyl alcohol etc.) can be used. Also, solids such as sulfates (barium sulfate, etc.), carbonates (magnesium carbonate, etc.), phosphates (calcium phosphate, etc.), metal oxides (titanium oxide, etc.), metal hydroxides (aluminum hydroxide, etc.), silica, etc. Fine powder of can also be used. Further, various surfactants can be used as a dispersion aid.

Desulfurization is carried out by dispersing the raw material polymer in water.
/ W emulsion is heated or sprayed. The temperature is raised by gradually raising the temperature of the O / W emulsion under a reduced pressure atmosphere. As a result, the water-insoluble organic solvent in the oil phase is removed and toner particles are obtained. Spraying is performed by spraying an O / W emulsion in a dry atmosphere. Also by this, the toner particles from which the water-insoluble organic solvent is removed can be obtained.

(Pulverizing Method) In the pulverizing method, the toner is manufactured by the procedure shown in FIG. In the pulverization method, a raw material in a polymer state is kneaded together with a colorant and other additives without being dispersed in water. This is crushed and classified to obtain toner particles. This is heat treated to make it spherical and then coated with fine particles. As a result, toner particles which are substantially spherical and whose surface is coated with fine particles are obtained.

Examples of the raw material polymer include styrene-based homopolymer resins, various styrene-based copolymer resins, acrylic resins, methacrylic resins, polyamide resins, epoxy resins, polyester resins, urea resins, polyurethane resins and poly resins. Vinyl acetate resin, polyvinyl chloride resin, polyethylene, polypropylene, polyol resin, rosin, modified rosin, terpene resin, phenol resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, Paraffin wax, etc. can be used. You may use these 2 or more types in mixture.

As the colorant, those listed in the suspension polymerization method can be used. Examples of other additives include a charge control agent and a release agent.

[Heat Treatment] In the above description, a heat treatment for spheroidization is included in the procedure of the grinding method. This is not generally performed at the time of toner production by the pulverization method, but this is particularly performed in the present embodiment. The purpose is to make the polyhedral toner particles having irregularities obtained by pulverization spherical. Therefore,
Toner particles are heated to the extent that the molecular structure does not change and soften and become spherical. It should be noted that toner particles manufactured by a manufacturing method other than the pulverization method need not be spherically formed by heat treatment, but it is not necessary to do so.

The spheroidizing is performed by jetting the classified toner with hot air. As a result, when the temperature of the toner is raised to a temperature equal to or higher than the glass transition point of the constituent resin, the particles are softened and the shape thereof becomes spherical. The treatment temperature is usually within the range of 150 to 300 ° C. This is sufficient for spheronization and does not change the molecular structure.

[Particle Coating] In the above description, in each method, particle coating is included in the procedure. Although this is not generally performed when the toner is manufactured by each of the above-mentioned methods, this is particularly performed in this embodiment. The purpose is to secure dismantling from the molded body. Specifically, polymer fine particles having a particle size in the range of 0.01 to 1.0 μm (more preferably 0.03 to 0.3 μm) are formed by emulsion polymerization method or soap-free emulsion polymerization method, and Attach to toner particles in water.
In the case of pulverized toner, fine particles are coated after heat treatment.

(Production of fine particles) As the raw material of fine particles,
Vinyl compound monomers can be used. For example, vinyl aromatic, acrylic ester, methacrylic ester, acrylic acid, methacrylic acid, vinyl ether,
Monomers such as can be used. You may mix and use 2 or more types. It is desirable to select the raw material so that it has a glass transition point higher than that of the toner particles. As a polymerization initiator, persulfate, hydrogen peroxide, hydroperoxide, etc. can be used. Also,
A charge control agent may be added, but no colorant is added. As the emulsifier in the emulsion polymerization method, those listed in the emulsion polymerization method of toner particles can be used.

(Coating of Toner Particles) Coating of fine particles to toner particles is performed as follows. That is, a dispersion liquid of fine particles is added to a slurry of toner particles. Then, the pH of the system is adjusted with hydrochloric acid so as to be 1.0. In that state, it is heated to about 50 ° C. and stirred for several hours. Then, after allowing to cool, it is filtered, washed with water, and vacuum dried to obtain toner particles. The surface of the toner particles thus obtained is coated with fine particles.

[Solidification] The toner particles produced by any of the above methods are solidified. The solidification is performed by placing the toner particles in a mold having an appropriate shape and compressing and molding. The compression pressure at this time is in the range of 10 to 500 N / cm ² (preferably 10 to 300 N / cm ² ). If the pressure is too low, the mechanical strength of the obtained solid toner as a molded body will be insufficient, and it will gradually collapse during handling. On the other hand, if the pressure is too high, the toner particles will be crushed. Moreover, the temperature at the time of compression should not exceed the glass transition point (about 50 to 70 ° C.) of the polymer of the toner particles. This is to prevent the toner particles from firmly adhering to each other.

The outer shape of the solid toner as a molded body is not particularly limited. Basically, there should be no problem in inserting the toner into the toner bottle of the image forming apparatus. One of the preferable outer shapes of the solid toner is a cylindrical shape. This is because the cylindrical solid toner can be used as it is as a toner supply roller or a developing roller in the image forming apparatus.

[Image Formation] Image formation by the solid toner manufactured as described above is performed as follows. That is, the solid toner as it is as a molded body is put into the toner bottle of the image forming apparatus. At this time, the area around the inlet and the hands are not contaminated with the toner. This is because dust is hardly generated because it is solidified.

Then, the molded body is crushed in the toner bottle and is subjected to development as the same single particle as a normal toner. An example thereof is shown in FIG. In the example of FIG. 5, a polishing roller 11 is provided in the toner bottle 10. The solid toner 1 put in the toner bottle 10 is
The surface of the polishing roller 11 is scraped off. The toner that is scraped off by the polishing roller 11 and becomes single particles,
Used for development. Alternatively, the solid toner can be crushed by ultrasonic vibration, warm air, induction heating, or the like.

At this time, the dismantling property of the solid toner is very good, and only the single particle toner is used for the development. The first reason is that the toner particles have a good spherical shape. That is, it has almost no irregularities that hinder crushing. This is because, as the toner particles, a polymerized toner that is made into particles in a dispersion system or a spheronized toner that has been spheroidized by heating is used. The second reason is that the toner particles are coated with fine particles before solidification. That is, the adhesion of the toner particles to each other is prevented by the fine particles.

Further, as shown in FIG. 6, the cylindrical solid toner 2 can be used as it is as a toner supply roller. In the example of FIG. 6, the solid toner 2 having a cylindrical shape is used.
From the above, toner is supplied to the developing roller 4, and the photosensitive drum 5 is further developed. In this example, the surface of the solid toner 2 is crushed little by little at the nip portion between the solid toner 2 and the developing roller 4, and a layer of single particles of toner is formed on the developing roller 4. You may provide some grinding | pulverization member in a nip part. Alternatively, a crushing member may be provided on the surface of the solid toner 2 at a position slightly upstream of the nip portion. The radius of the solid toner 2 gradually decreases as it is used, so that the expansion and contraction of the spring 6 ensures contact with the nip portion. Alternatively, a cylindrical solid toner may be used as a developing roller, and the toner may be directly applied to the photosensitive drum. Even in these cases, the disassembly property of the solid toner is very good for the same reason as above.

As described in detail above, in the present embodiment, a polymerized toner produced by a method of granulating raw materials in a dispersion system, such as a suspension polymerization method, an emulsion polymerization method, or an emulsion dispersion method, is molded, It is supposed to obtain solid toner. Alternatively, the spheronized toner that has been spheronized by heating is solidified to obtain a solid toner. Therefore, in the solid toner of this embodiment, the shape of the toner particles is spherical. For this reason, it is easy to handle when refilling the toner bottle, and is easy to disassemble. Therefore, since the image is formed only by the toner which is surely pulverized into the single particles, the toner is not clogged and the image quality is not deteriorated.
Further, in this embodiment, the surface of the toner particles is coated with fine particles before the toner is solidified. As a result, the dismantling property of the solid toner is further ensured. As described above, the solid toner, which has both the handling property and the disassembly property, and the image forming method and apparatus using the solid toner have been realized.

The present embodiment is merely an example and does not limit the present invention. Therefore, naturally, the present invention can be variously improved and modified without departing from the gist thereof. For example, raw materials, colorants, and other additives are not limited to those listed.

[0042]

As is apparent from the above description, according to the present invention, a solid toner which is reliably crushed in the apparatus and only the single particle of the toner is supplied to the developing portion, an image forming method using the solid toner, and A device is provided.

[Brief description of drawings]

FIG. 1 is a diagram showing an outline of toner production by a suspension polymerization method.

FIG. 2 is a diagram showing an outline of toner production by an emulsion polymerization method.

FIG. 3 is a diagram showing an outline of toner production by an emulsion dispersion method.

FIG. 4 is a diagram showing an outline of toner production by a pulverization method.

FIG. 5 is a diagram illustrating disassembly of solid toner.

FIG. 6 is a configuration diagram illustrating a main part of an image forming apparatus that uses a cylindrical solid toner as a toner supply roller.

[Explanation of symbols]

1 Solid toner

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/08 507E (72) Inventor Keiichi Yoshizawa 2-3-13 Azuchi-cho, Chuo-ku, Osaka City Osaka Toki Building Minolta Co., Ltd. (72) Inventor Ryutaro Iwase 2-3-3 Azuchi-cho, Chuo-ku, Osaka Osaka International Building Minolta Co., Ltd. F-term (reference) 2H005 AA08 AA15 AB03 AB06 AB09 2H077 AA02 AA12 AA15 AA16 AB01 AB12 AB13 AB14 AC04 AD02 AD06

Claims (5)

[Claims] 1. A solid toner, which is a molded product of toner, wherein the toner particles are toners (hereinafter, referred to as "polymerized toner") obtained by granulating raw materials in a dispersion system. 2. A solid toner, which is a molded product of toner, wherein the toner particles are toner that has undergone a spheroidizing treatment by heating (hereinafter, referred to as “spherical toner”). 3. The solid toner according to claim 1 or 2, wherein the toner particles have been subjected to a treatment of coating the surface with fine particles before molding. 4. A solid toner, which is a molded body of polymerized toner or spheroidized toner, is held in an apparatus, the solid toner is crushed in the apparatus to obtain toner particles, and the toner particles are used for developing a latent image. An image forming method using a solid toner. 5. In an image forming apparatus for developing a latent image by supplying toner to an image carrier, a toner roller formed by polymerizing toner or spheroidizing toner into a cylindrical shape is used as a toner supply source, and the toner roller is An image forming apparatus using solid toner, comprising: a supply roller in contact with the supply roller; and supplying toner from the toner roller to the supply roller at a nip portion between the toner roller and the supply roller.