JP2010139779A - Method for manufacturing toner, toner, developer, developing device and image forming apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing for manufacturing a toner at short times with a high yield, a toner of a good film state where resin fine particles are uniformly made like a film on the surfaces of toner base particles, and to provide toner manufactured by the manufacturing method, a developer containing the toner, a developing device using the developer, and an image forming apparatus. <P>SOLUTION: The method for manufacturing the toner includes: a resin fine particle sticking process; a spray process; and a filming process. In the spray process, a first spray means sprays spray liquid. In a period since the beginning of the spray and until additional spray time T1 establishing equation (1) 0.2τ≤T1≤τ(τ=V/Fair), a second spray means additionally sprays spray liquid of an amount of additional gas volume amount K establishing equation (2) 0.6κ≤K≤1.6κ(κ=(Fin/Fair)×V) into a powder channel. Here, Fin is gas volume flow, Fair indicates air volume flow of the air discharged out of the powder channel, and V is volume of the inside of the powder channel. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a toner manufacturing method, a toner manufactured by the manufacturing method, a developer containing the toner, a developing device using the developer, and an image forming apparatus.

  Conventionally, with the aim of improving the properties of powder particles such as toner particles, a surface modification treatment has been performed to coat the surface of the powder particles with a coating material, and the coating material is fixed to the surface of the powder particles. The immobilization method has been studied.

  As a specific surface modification treatment method, powder particles are flowed in a powder flow path by applying mechanical stirring force with a rotary stirring means such as a screw, blade, rotor, etc. Methods for spraying coating material onto body particles from a spray nozzle are known. For example, in Patent Document 1, a rotating agitating means is rotated at a peripheral speed of 5 to 160 m / sec to cause powder particles to flow in the apparatus, and a liquid is sprayed from the spray nozzle onto the powder particles in the fluid state. Discloses a method for surface modification of powder particles, in which fine solid particles contained in the liquid are fixed to the surface of the powder particles, or a film of a coating material contained in the liquid is formed on the surface of the powder particles. . According to the surface modification method disclosed in Patent Document 1, it is possible to improve the adhesion between fine solid particles or coating material and powder particles, and to shorten the time required for the surface modification treatment.

Japanese Patent Publication No. 5-10971

  However, in the method disclosed in Patent Document 1, the gas concentration of the liquid in the apparatus is gradually increased to be close to a desired value by spraying a certain amount of the liquid within a specific time. As the size increases, it takes a long time to bring the liquid gas concentration in the apparatus to a desired concentration. If the time for which the powder particles are exposed to the liquid gas becomes longer, the desired surface modification treatment is caused by deformation of the powder particles, aggregation of the powder particles, and adhesion of the powder particles and the coating material to the inner wall of the apparatus. There is a possibility that a problem that the powder particles subjected to the treatment cannot be obtained. In addition, there may be a problem that the yield of the powder particles subjected to the desired surface modification treatment is reduced.

  An object of the present invention is to provide a toner production method capable of producing a good toner in a film state in which resin fine particles are uniformly formed on the surface of toner base particles in a short time and with a high yield, a toner produced by the production method, and the toner And a developing device and an image forming apparatus using the developer.

The present invention introduces toner base particles and resin fine particles into a powder channel in which a rotary stirring means including a rotating disk and a rotating shaft provided with rotating blades is rotating, and causes the particles to flow in the powder channel. A resin fine particle attaching step for attaching resin fine particles to the toner base particle surface;
Using the first spraying means and the second spraying means, spraying the toner mother particles and the resin fine particles that are in a fluid state into the powder flow path with the carrier gas while spraying the spray liquid having an effect of plasticizing those particles, A spraying step of discharging the air containing the atomized liquid and carrier gas gasified in the powder channel out of the powder channel;
A film-forming step in which the rotation of the rotary stirring means is continued until the resin fine particles attached to the surface of the toner base particles form a film, and the toner base particles and the resin fine particles are repeatedly circulated in the powder flow path
In the spraying process, in addition to the spraying of the spray liquid by the first spraying means, the additional gas satisfying the following expression (2) from the second spraying means until the additional spraying time T1 satisfying the following expression (1) from the start of the spraying. The toner manufacturing method is characterized in that an amount of the spray liquid of a volume amount K is additionally sprayed into the powder flow path.
0.2τ ≦ T1 ≦ τ (τ = V / Fair) (1)
0.6κ ≦ K ≦ 1.6κ (κ = (Fin / Fair) × V) (2)
(Fin indicates the gas volume flow rate obtained by multiplying the spray rate of the spray liquid sprayed from the first spray means into the powder flow path by the volume when the spray liquid is gasified. (The air volume flow rate of the air discharged from the powder flow path is shown, and V indicates the volume in the powder flow path.)

The present invention also provides toner mother particles and resin fine particles into a powder channel in which a rotating agitator including a rotating disk and a rotating shaft having rotating blades and a rotating shaft are rotating, and flows in the powder channel. And a resin fine particle attaching step for attaching the resin fine particles to the surface of the toner base particles;
The spraying means is used to spray toner liquid and toner fine particles that are in a fluidized state into the powder channel by spraying a spray liquid that has the effect of plasticizing those particles into the powder channel. Spraying step of discharging the air containing the atomized liquid and carrier gas out of the powder flow path;
A film-forming step in which the rotation of the rotary stirring means is continued until the resin fine particles attached to the surface of the toner base particles form a film, and the toner base particles and the resin fine particles are repeatedly circulated in the powder flow path.
In the spraying step, the amount of spray from the spraying means is increased by an amount corresponding to the increased gas volume k satisfying the following formula (4) from the start of spraying by the spraying means to the increasing spray time T2 satisfying the following formula (3). This is a method for producing a toner.
0.2τ ≦ T2 ≦ τ (τ = V / Fair) (3)
0.6κ ≦ k ≦ 1.6κ (κ = (Fin / Fair) × V) (4)
(Fin indicates the gas volume flow rate obtained by multiplying the spray rate when the spray liquid is sprayed into the powder flow path without increasing by the volume amount when the spray liquid is gasified. (The air volume flow rate of the air discharged from the body channel is shown, and V shows the volume in the powder channel.)

  In addition, the present invention is characterized in that the time of the film forming process is 10 minutes to 45 minutes.

  Further, the invention is characterized in that the spray liquid is an alcohol having a LEL concentration of 1.7 vol% or more and 6.7 vol% or less when gasified.

  In the invention, the spray liquid is a lower alcohol having 3 or less carbon atoms in the molecule.

  The present invention also provides a toner manufactured by the toner manufacturing method.

The present invention also provides a developer comprising the toner.
Further, the present invention is a two-component developer comprising the toner and a carrier.

  According to another aspect of the present invention, there is provided a developing device that develops a latent image formed on an image carrier using the developer to form a toner image.

The present invention also provides an image carrier on which a latent image is formed,
A latent image forming means for forming a latent image on the image carrier;
An image forming apparatus comprising the developing device.

  According to the present invention, the toner manufacturing method includes a resin fine particle attaching step, a spraying step, and a film forming step. In the resin fine particle adhesion step, the toner base particles and the resin fine particles are put into a powder flow path in which a rotating stirring means including a rotating disk and a rotating shaft provided with rotating blades is rotating, and a resin is applied to the surface of the toner base particles. Adhere fine particles. The spraying step is performed by spraying a spray liquid for plasticizing the toner base particles and resin fine particles in a fluid state from the first spraying means with a carrier gas while gasifying the sprayed liquid in the powder flow path and Air containing carrier gas is discharged out of the powder flow path. In the film forming process, the rotation of the rotary stirring means is continued until the resin fine particles attached to the surface of the toner base particles are formed into a film, and the toner base particles and the resin fine particles are repeatedly circulated in the powder flow path. In the spraying step, in addition to the spraying of the spray liquid by the first spraying means, the additional gas satisfying the above formula (2) from the second spraying means until the additional spraying time T1 satisfying the above formula (1) from the start of the spraying. An amount of spray liquid of volume K is additionally sprayed into the powder channel.

  When supplying the spray liquid into the powder flow path from the state where the liquid gas obtained by gasifying the spray liquid does not exist in the powder flow path, a certain amount of spray liquid is sprayed over a specific time to In the method of gradually increasing the liquid gas concentration in the channel and approaching the desired value, the device size increases, that is, the liquid gas concentration in the powder channel increases as the volume in the powder channel increases. Since it takes a long time to obtain the desired toner, deformation of the shape of the toner particles and aggregation between the toner particles are caused, and a desired toner cannot be obtained.

  The spray amount of the spray liquid necessary to keep the gas concentration in the powder flow path constant depends on the apparatus size, the target spray concentration, the spray time, the processing amount, etc., but in the spray process, the first spray means In addition to spraying, the second spraying means additionally supplies an amount of spray liquid necessary to quickly bring the gas concentration in the powder channel to a desired concentration according to the apparatus size, that is, the volume in the powder channel. As a result, the rising of the gas concentration in the powder flow path can be improved and film formation can be performed in a short time, so that deformation of the shape of the toner particles and aggregation between the toner particles can be suppressed. Further, since the resin fine particles can be uniformly formed on the surface of the toner base particles, the film quality can be improved. By producing the toner by such a method, the generation of coarse particles can be suppressed, and a toner having good film quality can be stably obtained.

  In addition, the material selectivity of the toner base particles and resin fine particles is wide, and the degree of freedom in designing the charging characteristics and fluidity of the toner is large, and the storage stability is also obtained when a low melting point material is used for the toner base particles. A toner that does not deteriorate can be produced stably.

  According to the invention, the toner manufacturing method includes a resin fine particle attaching step, a spraying step, and a film forming step. In the resin fine particle adhesion step, the toner base particles and the resin fine particles are put into a powder flow path in which a rotating stirring means including a rotating disk and a rotating shaft provided with rotating blades is rotating, and a resin is applied to the surface of the toner base particles. Adhere fine particles. In the spraying step, the spray liquid and carrier gas gasified in the powder flow channel are sprayed onto the toner base particles and resin fine particles in a fluidized state while spraying the spray liquid for plasticizing those particles from the spray means with the carrier gas. The air containing is discharged out of the powder flow path. In the film forming process, the rotation of the rotary stirring means is continued until the resin fine particles attached to the surface of the toner base particles are formed into a film, and the toner base particles and the resin fine particles are repeatedly circulated in the powder flow path. In the spraying process, the amount of spray from the spraying means is increased by an amount corresponding to the increased gas volume k satisfying the above formula (4) for the increased spray time T2 satisfying the above formula (3) from the start of spraying by the spraying means. It is characterized by that.

  When supplying the spray liquid into the powder flow path from the state where the liquid gas obtained by gasifying the spray liquid does not exist in the powder flow path, a certain amount of spray liquid is sprayed over a specific time to In the method of gradually increasing the liquid gas concentration in the channel and approaching the desired value, the device size increases, that is, the liquid gas concentration in the powder channel increases as the volume in the powder channel increases. Since it takes a long time to obtain the desired toner, deformation of the shape of the toner particles and aggregation between the toner particles are caused, and a desired toner cannot be obtained.

  The spray amount of the spray liquid necessary to keep the gas concentration in the powder channel constant depends on the device size, target spray concentration, spray time, throughput, etc. The amount of spray liquid required to quickly achieve the desired gas concentration is increased according to the device size, that is, the volume in the powder channel, thereby improving the rise of the gas concentration in the powder channel. Since film formation can be performed in a short time, deformation of the shape of the toner particles and aggregation between the toner particles can be suppressed. Further, since the resin fine particles can be uniformly formed on the surface of the toner base particles, the film quality can be improved. By producing the toner by such a method, the generation of coarse particles can be suppressed, and a toner having good film quality can be stably obtained.

  In addition, the material selectivity of the toner base particles and resin fine particles is wide, and the degree of freedom in designing the charging characteristics and fluidity of the toner is large, and the storage stability is also obtained when a low melting point material is used for the toner base particles. A toner that does not deteriorate can be produced stably.

  According to the invention, the time for the film forming step is 10 minutes or longer and 45 minutes or shorter. The film formation time can be shortened by additionally spraying the spray liquid. In the present invention, the time of the spraying process is 10 minutes or more and 45 minutes or less, thereby preventing the deformation of the toner particle shape and the aggregation between the toner particles. Can be remarkably expressed. Therefore, the generation of coarse particles can be suppressed, and a toner having good film quality can be obtained more stably.

  Further, according to the present invention, the spray liquid is an alcohol having a LEL concentration of 1.7 vol% or more and 6.7 vol% or less when gasified. Alcohol having an LEL concentration lower than 1.7% by volume is too low in the ability to plasticize the toner base particles and resin fine particles, and the formation of resin fine particles on the surface of the toner base particles does not proceed favorably, and is required for film formation. The time is too long. For this reason, deformation of the toner particles and aggregation between the toner particles are caused, and it becomes impossible to obtain a toner having a desired shape and particle diameter with high yield. In addition, when an alcohol having a LEL concentration higher than 6.7% by volume is used, the toner base particles and the resin fine particles are too plasticized, and the toner base particles or the resin fine particles are fixed or aggregated. As a result, a toner having a desired particle size cannot be obtained in a high yield.

  According to the invention, the spray liquid is a lower alcohol having 3 or less carbon atoms in the molecule. Since the liquid is a lower alcohol having such a carbon number, the wettability of the resin fine particles as the coating material to the toner mother particles can be improved, so that the resin fine particles adhere to the entire surface or most of the toner mother particles. In addition, deformation and film formation of the attached resin fine particles are facilitated. Further, since the lower alcohol having 3 or less carbon atoms in the molecule has a high vapor pressure, the drying time when removing the spray liquid from the toner base particles and the resin fine particles can be shortened, and the toner base particles are aggregated. Can be suppressed. Therefore, the generation of coarse particles can be suppressed, and a toner with good film quality can be obtained more stably.

  According to the present invention, the toner is manufactured by the toner manufacturing method of the present invention. The toner produced by the production method of the present invention has no coarse particles and good film quality. Even if a low melting point material is used for the toner base particles, the storage stability is good. By forming an image using such a toner, a good toner image can be formed over a long period of time.

  According to the invention, the developer contains the toner of the invention. Since the toner of the present invention does not deteriorate storage stability even when toner base particles having a low melting point are used for fixing at low temperature, the fluidity in the developing tank is also deteriorated even when used in a high temperature atmosphere. The developer can be reduced, and good developability can be secured over a long period of time.

  According to the invention, the developer is a two-component developer containing the toner of the invention and a carrier. Even when low melting point toner base particles are used for fixing at low temperature, the toner of the present invention does not deteriorate the storage stability. A two-component developer that can ensure good developability can be obtained.

  According to the invention, the developing device forms a toner image using the developer of the invention. By performing development using the developer of the present invention, a developing device capable of stably forming a good toner image on the surface of the image carrier over a long period of time can be obtained.

  According to the invention, the image forming apparatus forms an image using the developing device of the invention. As a result, a good image can be stably obtained over a long period of time.

1. Toner Manufacturing Method FIG. 1 is a flowchart showing an example of the procedure of a toner manufacturing method according to the first embodiment of the present invention. As shown in FIG. 1, the toner manufacturing method according to the first embodiment of the present invention includes a toner base particle preparation step S1 for preparing toner base particles, a resin fine particle preparation step S2 for preparing resin fine particles, and a resin. And a coating step S3 for coating the surface of the toner base particles with fine particles.

(1) Toner mother particle production step S1
In the toner base particle preparation step of Step S1, toner base particles to be coated with resin fine particles are prepared. The toner base particles are particles containing at least a binder resin and a colorant. The method for producing the toner base particles is not particularly limited, and can be produced by a known method. Examples thereof include dry methods such as a pulverization method, and wet methods such as a suspension polymerization method, an emulsion aggregation method, a dispersion polymerization method, a dissolution suspension method, and a melt emulsification method. Hereinafter, a method for producing toner mother particles by a pulverization method will be described.

(Production method of toner mother particles by pulverization method)
In the production of toner mother particles by a pulverization method, a toner composition containing a binder resin, a colorant and other additives is dry-mixed with a mixer and then melt-kneaded with a kneader. The kneaded product obtained by melt kneading is cooled and solidified, and the cooled and solidified solidified product is pulverized by a pulverizer. Thereafter, toner base particles are obtained by adjusting the particle size such as classification as required.

  Known mixers can be used, such as Henschel mixer (trade name, manufactured by Mitsui Mining Co., Ltd.), super mixer (trade name, manufactured by Kawata Co., Ltd.), and Mechano Mill (trade name, manufactured by Okada Seiko Co., Ltd.). Henschel type mixing device, Ongmill (trade name, manufactured by Hosokawa Micron Corporation), hybridization system (trade name, manufactured by Nara Machinery Co., Ltd.), and Cosmo system (trade name, manufactured by Kawasaki Heavy Industries, Ltd.) .

  As the kneader, known ones can be used. For example, a general kneader such as a twin-screw extruder, a three-roller, and a lab blast mill can be used. More specifically, for example, uniaxial or biaxial, such as TEM-100B (trade name, manufactured by Toshiba Machine Co., Ltd.), PCM-65 / 87, and PCM-30 (all of which are trade names, manufactured by Ikegai Co., Ltd.). Extruders, as well as open roll type kneaders such as Needex (trade name, manufactured by Mitsui Mining Co., Ltd.). Among these, an open roll type kneader is preferable.

  As a pulverizer, for example, a jet-type pulverizer that uses a supersonic jet stream, and a solidified material is introduced into a space formed between a rotor (rotor) and a stator (liner) that rotate at high speed. And an impact type pulverizer for pulverization.

  For the classification, a known classifier capable of removing the excessively pulverized toner base particles by classification by centrifugal force or classification by wind force can be used, and examples thereof include a swirl type wind classifier (rotary wind classifier).

(Toner base material)
As described above, the toner base particles include a binder resin and a colorant. The binder resin is not particularly limited, and a known binder resin for black toner or color toner can be used. For example, styrene resin such as polystyrene and styrene-acrylate copolymer resin, polymethyl methacrylate, etc. And acrylic resins such as polyethylene, polyolefin resins such as polyethylene, polyesters, polyurethanes, and epoxy resins. Moreover, you may use resin obtained by mixing a release agent with the raw material monomer mixture of binder resin, and performing a polymerization reaction. Binder resin can be used individually by 1 type, or can use 2 or more types together.

  Among the above binder resins, polyester is excellent in transparency and can impart good powder fluidity, low-temperature fixability, secondary color reproducibility, etc. to toner base particles, and is therefore suitable as a binder resin for color toners. It is. Known polyesters can be used, and examples thereof include polycondensates of polybasic acids and polyhydric alcohols.

  As the polybasic acid, those known as monomers for polyesters can be used, for example, terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid and other aromatic carboxylic acids, maleic anhydride, Examples thereof include aliphatic carboxylic acids such as fumaric acid, succinic acid, alkenyl succinic anhydride and adipic acid, and methyl esterified products of these polybasic acids. A polybasic acid can be used individually by 1 type, or can use 2 or more types together.

  As the polyhydric alcohol, those known as monomers for polyesters can be used. For example, aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, hexanediol, neopentylglycol, glycerin, cyclohexanediol, cyclohexanediene, etc. Examples thereof include aromatic diols such as alicyclic polyhydric alcohols such as methanol and hydrogenated bisphenol A, ethylene oxide adducts of bisphenol A, and propylene oxide adducts of bisphenol A. A polyhydric alcohol can be used individually by 1 type, or can use 2 or more types together.

  The polycondensation reaction between the polybasic acid and the polyhydric alcohol can be carried out according to a conventional method. For example, the polybasic acid and the polyhydric alcohol are contacted in the presence or absence of an organic solvent and in the presence of a polycondensation catalyst. The process is terminated when the acid value, softening temperature, etc. of the produced polyester reach a predetermined value. Thereby, polyester is obtained. When a methyl esterified product of a polybasic acid is used as a part of the polybasic acid, a demethanol polycondensation reaction is performed. In this polycondensation reaction, for example, the carboxyl group content at the end of the polyester can be adjusted by appropriately changing the mixing ratio of polybasic acid and polyhydric alcohol, the reaction rate, etc., and thus the properties of the resulting polyester are modified. it can. When trimellitic anhydride is used as the polybasic acid, a modified polyester can also be obtained by introducing a carboxyl group into the main chain of the polyester. A self-dispersible polyester in water in which a hydrophilic group such as a carboxyl group or a sulfonic acid group is bonded to the main chain and / or side chain of the polyester can also be used. Further, polyester and acrylic resin may be grafted.

  The binder resin preferably has a glass transition point of 30 ° C. or higher and 80 ° C. or lower. If the glass transition point of the binder resin is less than 30 ° C., blocking in which the toner thermally aggregates easily occurs in the image forming apparatus, and storage stability may be lowered. When the glass transition point of the binder resin exceeds 80 ° C., the fixability of the toner to the recording medium is lowered, and there is a possibility that fixing failure occurs.

  As the colorant, organic dyes, organic pigments, inorganic dyes, inorganic pigments and the like commonly used in the electrophotographic field can be used.

  Examples of the black colorant include carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, nonmagnetic ferrite, magnetic ferrite, and magnetite.

  Examples of yellow colorants include chrome lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navel yellow, naphthol yellow S, Hansa yellow G, Hansa yellow 10G, benzidine yellow G, and benzidine. Yellow GR, Quinoline Yellow Lake, Permanent Yellow NCG, Tartrazine Lake, C.I. I. Pigment yellow 12, C.I. I. Pigment yellow 13, C.I. I. Pigment yellow 14, C.I. I. Pigment yellow 15, C.I. I. Pigment yellow 17, C.I. I. Pigment yellow 74, C.I. I. Pigment yellow 93, C.I. I. Pigment yellow 94, C.I. I. Pigment yellow 138, C.I. I. Pigment yellow 180, C.I. I. And CI Pigment Yellow 185.

  Examples of the orange colorant include red chrome yellow, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, indanthrene brilliant orange RK, benzidine orange G, indanthrene brilliant orange GK, C.I. I. Pigment orange 31, C.I. I. And CI Pigment Orange 43.

  Examples of red colorants include bengara, cadmium red, red lead, mercury sulfide, cadmium, permanent red 4R, risor red, pyrazolone red, watching red, calcium salt, lake red C, lake red D, and brilliant carmine 6B. Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B, C.I. I. Pigment red 2, C.I. I. Pigment red 3, C.I. I. Pigment red 5, C.I. I. Pigment red 6, C.I. I. Pigment red 7, C.I. I. Pigment red 15, C.I. I. Pigment red 16, C.I. I. Pigment red 48: 1, C.I. I. Pigment red 53: 1, C.I. I. Pigment red 57: 1, C.I. I. Pigment red 122, C.I. I. Pigment red 123, C.I. I. Pigment red 139, C.I. I. Pigment red 144, C.I. I. Pigment red 149, C.I. I. Pigment red 166, C.I. I. Pigment red 177, C.I. I. Pigment red 178, C.I. I. And CI Pigment Red 222.

  Examples of purple colorants include manganese purple, fast violet B, and methyl violet lake.

  Examples of blue colorants include bitumen, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, phthalocyanine blue partially chlorinated products, first sky blue, induslen blue BC, C.I. I. Pigment blue 15, C.I. I. Pigment blue 15: 2, C.I. I. Pigment blue 15: 3, C.I. I. Pigment blue 16, C.I. I. And CI Pigment Blue 60.

  Examples of the green colorant include chrome green, chromium oxide, pigment green B, micalite green lake, final yellow green G, C.I. I. And CI Pigment Green 7.

  Examples of the white colorant include compounds such as zinc white, titanium oxide, antimony white, and zinc sulfide.

  One colorant can be used alone, or two or more different colorants can be used in combination. Moreover, even if it is the same color, 2 or more types can be used together. The amount of the colorant used is not particularly limited, but is preferably 5 parts by weight or more and 20 parts by weight or less, more preferably 5 parts by weight or more and 10 parts by weight or less with respect to 100 parts by weight of the binder resin.

  The colorant may be used as a master batch in order to uniformly disperse it in the binder resin. Two or more colorants may be used in the form of composite particles. The composite particles can be produced, for example, by adding an appropriate amount of water, lower alcohol or the like to two or more colorants, granulating with a general granulator such as a high speed mill, and drying. The master batch or composite particles are mixed into the toner composition during dry mixing.

  The toner base particles may contain a charge control agent in addition to the binder resin and the colorant. As the charge control agent, a charge control agent for positive charge control and negative charge control commonly used in this field can be used.

  Examples of charge control agents for controlling positive charge include nigrosine dyes, basic dyes, quaternary ammonium salts, quaternary phosphonium salts, aminopyrines, pyrimidine compounds, polynuclear polyamino compounds, aminosilanes, nigrosine dyes and derivatives thereof, and triphenylmethane. Derivatives, guanidine salts, amidine salts and the like.

  Charge control agents for controlling negative charges include oil-soluble dyes such as oil black and spiron black, metal-containing azo compounds, azo complex dyes, metal salts of naphthenic acid, metal salts of salicylic acid and its derivatives (metals are metal Chromium, zinc, zirconium, etc.), boron compounds, fatty acid soaps, long-chain alkyl carboxylates, resin acid soaps, and the like. A charge control agent can be used individually by 1 type, or can use 2 or more types together as needed. The amount of the charge control agent used is not particularly limited and can be appropriately selected from a wide range, but is preferably 0.5 parts by weight or more and 3 parts by weight or less with respect to 100 parts by weight of the binder resin.

  The toner base particles may contain a releasing agent in addition to the binder resin and the colorant. As the release agent, those commonly used in this field can be used, for example, petroleum wax such as paraffin wax and derivatives thereof, microcrystalline wax and derivatives thereof, Fischer-Tropsch wax and derivatives thereof, polyolefin wax (polyethylene wax, polypropylene Wax etc.) and derivatives thereof, low molecular weight polypropylin wax and derivatives thereof, hydrocarbon polymer waxes such as polyolefin polymer wax (low molecular weight polyethylene wax etc.) and derivatives thereof, carnauba wax and derivatives thereof, rice wax and derivatives thereof , Candelilla wax and its derivatives, plant wax such as wood wax, animal wax such as beeswax and whale wax, fatty acid amide, phenol fatty acid ester, etc. Oil-based synthetic waxes, long-chain carboxylic acids and their derivatives, long-chain alcohols and derivatives thereof, silicone polymers, such as higher fatty acids. Derivatives include oxides, block copolymers of vinyl monomers and waxes, graft modified products of vinyl monomers and waxes, and the like. The amount of the wax used is not particularly limited and can be appropriately selected from a wide range, but is preferably 0.2 to 20 parts by weight, more preferably 0.5 to 10 parts by weight, particularly preferably 100 parts by weight of the binder resin. 1.0 to 8.0 parts by weight.

(Toner mother particles)
The toner base particles obtained through the toner base particle preparation step S1 preferably have a volume average particle size of 4 μm or more and 8 μm or less. When the volume average particle size of the toner base particles is 4 μm or more and 8 μm or less, a high-definition image can be stably formed over a long period of time. Further, by reducing the particle size to this range, a high image density can be obtained even with a small amount of adhesion, and the toner consumption can be reduced. If the volume average particle size of the toner base particles is less than 4 μm, the particle size of the toner base particles becomes too small, and there is a possibility that high charge and low fluidity may occur. When this high charging and low fluidization occur, it becomes impossible to stably supply the toner to the photoreceptor, and there is a possibility that background fogging and a decrease in image density may occur. When the volume average particle size of the toner base particles exceeds 8 μm, the particle size of the toner base particles becomes too large, so that the layer thickness of the formed image becomes high and an image that feels remarkably graininess is obtained to obtain a high-definition image. I can't. Further, as the toner base particle size increases, the specific surface area decreases and the toner charge amount decreases. When the charge amount of the toner is small, the toner is not stably supplied to the photoconductor, and there is a possibility that in-machine contamination due to toner scattering occurs.

(2) Resin fine particle preparation step S2
In the resin fine particle preparation step in step S2, dried resin fine particles are prepared. Any method may be used as a method for drying the resin fine particles. For example, dry resin fine particles can be obtained by using a method such as hot air heat receiving drying, conduction heat transfer drying, far-infrared drying, or microwave drying. . The resin fine particles are used as a material for coating the surface of the toner base particles in the coating step S3 described later. By using resin fine particles as a film-forming material that coats the surface of the toner base particles, for example, toner aggregation due to melting of low melting point components such as a release agent contained in the toner base particles during storage of the developer can be prevented. Can do. Further, since the shape of the resin fine particles remains on the surface of the toner base particles, a toner having excellent cleaning properties can be obtained as compared with a toner having a smooth surface.

(Method for preparing resin fine particles)
The resin fine particles can be obtained, for example, by emulsifying and dispersing a resin, which is a resin fine particle raw material, with a homogenizer or the like. It can also be obtained by polymerization of resin monomer components.

(Resin fine particle raw material)
As the resin used as the resin fine particle raw material, for example, a resin used for a general toner raw material can be used, and examples thereof include polyester, acrylic resin, styrene resin, and styrene-acrylic copolymer. The resin fine particles preferably include an acrylic resin and a styrene-acrylic copolymer among the resins exemplified above. Acrylic resins and styrene-acrylic copolymers have many advantages, such as being light and having high strength, being easy to obtain particles having high transparency, low cost, and uniform particle diameter.

  The resin used as the resin fine particle raw material may be the same type of resin as the binder resin contained in the toner base particles or a different type of resin. In that respect, it is preferable to use different types of resins. When a resin different from the toner base particles is used as the resin fine particle raw material, the softening temperature of the resin used as the resin fine particle raw material may be higher than the softening temperature of the binder resin contained in the toner base particles. preferable. As a result, the toner produced in the present embodiment can improve storage stability without fusing the toners together during storage. The softening temperature of the resin used as the resin fine particle raw material is preferably 80 ° C. or higher and 140 ° C. or lower, although it depends on the image forming apparatus in which the toner is used. By using a resin having such a temperature range, a toner having both storage stability and fixing ability can be obtained.

(Resin fine particles)
The resin fine particles are required to have a volume average particle size sufficiently smaller than the average particle size of the toner base particles, and are preferably 0.05 μm or more and 1 μm or less. The volume average particle size of the resin fine particles is more preferably 0.1 μm or more and 0.5 μm or less. When the volume average particle diameter of the resin fine particles is 0.05 μm or more and 1 μm or less, a protrusion having a suitable size is formed on the surface of the toner coating layer. As a result, the toner manufactured in the present embodiment is easily caught by the cleaning blade during cleaning, so that the cleaning property is improved.

(3) Covering step S3
In the coating step of step S3, the surface of the toner base particles is coated with resin fine particles. First, a toner manufacturing apparatus used in this process will be described. In the coating step in step S3, for example, the toner production apparatus 201 shown in FIG. 2 is used, and the resin fine particles prepared in the resin fine particle preparation step in step S2 are attached to the surface of the toner mother particles produced in the toner mother particle production step in step S1. Thus, a resin film is formed on the surface of the toner base particles by a synergistic effect of the circulation in the apparatus and the impact force by stirring.

(Toner production equipment)
FIG. 2 is a front view showing the configuration of the toner manufacturing apparatus 201 used in the toner manufacturing method according to the first embodiment of the present invention. FIG. 3 is a schematic cross-sectional view of the toner manufacturing apparatus 201 shown in FIG. 2 as viewed from the cutting plane line A200-A200. The toner manufacturing apparatus 201 includes a powder flow path 202, a spraying means 203, a rotary stirring means 204, a temperature adjustment jacket (not shown), a powder input unit 206, and a powder recovery unit 207. Is done. The rotary stirring means 204 and the powder flow path 202 constitute a circulation means.

[Powder channel]
The powder channel 202 includes a stirring unit 208 and a powder flow unit 209. The stirring unit 208 is a cylindrical container-like member having an internal space. In the stirring unit 208, openings 210 and 211 are formed. The opening 210 is formed so as to penetrate the side wall including the surface 208a of the stirring unit 208 in the thickness direction at a substantially central portion of the surface 208a on one side in the axial direction of the stirring unit 208. The opening 211 is formed on a side surface 208b perpendicular to the surface 208a on one side in the axial direction of the stirring unit 208 so as to penetrate the side wall including the side surface 208b of the stirring unit 208 in the thickness direction. The powder flow part 209 has one end connected to the opening 210 and the other end connected to the opening 211. As a result, the internal space of the stirring unit 208 and the internal space of the powder flow unit 209 are communicated to form the powder flow path 202. The toner base particles, resin fine particles, and gas flow through the powder flow path 202. The powder flow path 202 is provided such that the powder flow direction, which is the direction in which the toner base particles and the resin fine particles flow, is a constant direction.

(Rotating stirring means)
The rotating stirring means 204 includes a rotating shaft 218, a disk-shaped rotating disk 219, and a plurality of stirring blades 220. The rotation shaft 218 has an axis line that coincides with the axis line of the stirring unit 208 and is formed on the surface 208c on the other side in the axial direction of the stirring unit 208 so as to penetrate the side wall including the surface 208c in the thickness direction. It is provided so as to be inserted through. The rotary shaft 218 is a cylindrical rod-like member that rotates around an axis line by a motor (not shown) in a rotary shaft portion (not shown) that is a portion that drives the rotary shaft 218. The rotating disk 219 is a disk-like member that is supported by the rotating shaft 218 so that its axis coincides with the axis of the rotating shaft 218 and rotates as the rotating shaft 218 rotates. The plurality of stirring blades 220 are supported by the peripheral portion of the turntable 219 and rotate as the turntable 219 rotates. Powders such as toner base particles and resin fine particles flow in the powder flow path 202 by the flow of air generated by the rotation of the rotary stirring means 204.

  From the rotating shaft portion, air can be flowed into the powder flow path 202. Air and liquid gas in the powder channel 202 are discharged from the gas discharge unit 222. The air and liquid gas discharged from the gas discharge unit 222 in this way are referred to as discharged air. In the gas exhaust part 222, the flow rate of the exhaust air can be adjusted. A plurality of gas discharge units 222 may be provided.

  The rotating shaft 218 can rotate at a peripheral speed of 50 m / sec or more at the outermost periphery. The outermost periphery is a portion of the rotary stirring means 204 having the longest distance from the rotary shaft 218 in the direction perpendicular to the axial direction of the rotary shaft 218.

[Spraying means]
The spraying means includes a first spraying means 203a and a second spraying means 203b. Hereinafter, the first spraying means 203a and the second spraying means 203b may be collectively referred to as the spraying means 203. The first spraying means 203a is provided in the powder flow part 209 of the powder flow path 202 at the powder flow part closest to the opening 211 in the flow direction of the toner base particles and the resin fine particles. The first spraying means 203a mixes a liquid storage section (not shown) that stores the spray liquid, a carrier gas supply section (not shown) that supplies a carrier gas, a liquid and a carrier gas, and the resulting mixture is mixed with the powder flow path 202. And a first second fluid nozzle 205a for spraying liquid droplets onto the toner base particles present therein. The first second fluid nozzle 205 a is provided by being inserted through an opening formed in the outer wall of the powder flow path 202. As the 2nd spraying means 203b, the thing of the same structure as the 1st spraying means 203a can be used. In this case, the second spraying means is preferably attached in the powder flow part 209, and for example, is attached in the powder flow part 209 downstream from the first spray means 203a.

  As the liquid sprayed by the spraying means (hereinafter also referred to as “spraying liquid”), a liquid having an effect of plasticizing toner base particles and resin fine particles is used. The spray liquid will be described in detail later. Compressed air or the like can be used as the carrier gas.

[Temperature adjustment jacket]
A temperature adjusting jacket (not shown), which is a temperature adjusting means, is provided in at least a part of the outside of the powder flow path 202, and the inside of the powder flow path 202 and the rotary stirring are passed through a cooling medium or a heating medium into the space inside the jacket. The temperature of the means 204 is adjusted to a predetermined temperature. In the present embodiment, the temperature adjusting jacket is preferably provided on the entire outside of the powder flow path 202.

[Powder input unit and powder recovery unit]
A powder input unit 206 and a powder recovery unit 207 are connected to the powder flow unit 209 of the powder channel 202. FIG. 4 is a front view showing a configuration around the powder input unit 206 and the powder recovery unit 207. The powder input unit 206 includes a hopper (not shown) that supplies toner base particles and resin fine particles, a supply pipe 212 that communicates the hopper and the powder flow path 202, and an electromagnetic valve 213 provided in the supply pipe 212. The toner base particles and resin fine particles supplied from the hopper are supplied to the powder flow path 202 through the supply pipe 212 in a state where the flow path in the supply pipe 212 is opened by the electromagnetic valve 213. The toner base particles and resin fine particles supplied to the powder flow path 202 flow through in a constant powder flow direction by stirring by the rotary stirring means 204. When the flow path in the supply pipe 212 is closed by the electromagnetic valve 213, the toner base particles and the resin fine particles are not supplied to the powder flow path 202.

  The powder recovery unit 207 includes a recovery tank 215, a recovery pipe 216 that connects the recovery tank 215 and the powder flow path 202, and an electromagnetic valve 217 provided in the recovery pipe 216. In a state where the flow path in the collection pipe 216 is opened by the electromagnetic valve 217, the toner particles flowing through the powder flow path 202 are collected in the collection tank 215 via the collection pipe 216. Further, when the flow path in the collection pipe 216 is closed by the electromagnetic valve 217, the toner particles, toner base particles, and resin fine particles flowing through the powder flow path 202 are not collected.

(Coating process)
The covering step S3 using the toner manufacturing apparatus 201 includes a temperature adjusting step S3a, a resin fine particle attaching step S3b, a spraying step S3c, a film forming step S3d, and a collecting step S3e.

[Temperature adjustment step S3a]
In the temperature adjustment step of step S3a, the temperature of the powder flow path 202 and the rotary stirring means 204 are adjusted to a predetermined temperature while rotating the rotary stirring means 204. As a method for this, a medium such as water is passed through a temperature adjustment jacket disposed outside the powder flow path 202. If the temperature in the powder flow path 202 is not suitable, toner mother particles and resin fine particles introduced in the resin fine particle adhesion step S3b described later are likely to adhere to the inner wall of the powder flow path, and the resin fine particles are smoothly formed into a film. There is a risk of not proceeding. By adjusting the inside of the powder flow path 202 and the rotary stirring means 204 to a predetermined temperature, the toner base particles and the resin fine particles can be controlled to a temperature at which they are not softened and deformed, and the resin fine particles adhere to the toner base particles. And film formation proceeds smoothly. In addition, since the adhesion force to the inner wall of the powder flow path is reduced, the adhesion of the toner base particles and the resin fine particles to the inner wall of the powder flow path can be suppressed, and the inside of the powder flow path is narrowed by the toner base particles and the resin fine particles. Can be prevented. Accordingly, it is possible to produce a toner having excellent cleaning properties in which the surface of the toner base particles is uniformly coated with the resin fine particles with a high yield.

  Further, in the spraying step S3c and the film forming step S3d, which will be described later, the temperature applied to the toner base particles, the resin fine particles and the liquid is less varied, and it is possible to maintain a stable fluid state of the toner base particles and the resin fine particles. .

  In the coating step S3, the toner base particles and resin fine particles made of synthetic resin or the like collide with the inner wall of the normal powder flow path many times, and at the time of the collision, part of the collision energy is converted into thermal energy, and the toner Accumulated in mother particles and resin particles. As the number of collisions increases, the thermal energy accumulated in these particles increases, and eventually the toner base particles and resin fine particles soften and adhere to the inner wall of the powder flow path. By adjusting the temperature through the cooling medium or heating medium in the space, it is possible to suppress the adhesion of the toner base particles and the resin fine particles to the inner wall of the powder flow path due to excessive temperature rise, and the liquid sprayed from the spraying means is powdered. It is possible to suppress adhesion of toner base particles and resin fine particles to the powder flow path due to accumulation in the body flow path and blockage in the powder flow path due to the accumulation. Therefore, the toner base particles are uniformly coated with the resin fine particles, and the toner excellent in the cleaning property coated with the resin layer can be produced with high yield.

  In the powder flow section 209 downstream of the spraying means 203, the sprayed liquid remains without being dried, and if the temperature is not appropriate, the drying speed becomes slow and the liquid tends to stay. When the toner base particles come into contact, the toner base particles easily adhere to the inner wall of the powder flow path 202. This can be a source of aggregation of toner base particles. On the inner wall in the vicinity of the opening 210, the toner base particles that flow through the powder flow-through portion 209 and flow into the stirring portion 208 from the opening 210 and the toner base that flows in the stirring portion 208 by stirring by the rotary stirring means 204. Easy to collide with particles. As a result, the collided toner base particles are likely to adhere to the vicinity of the opening 210. Therefore, by adjusting the temperature of the portion where the toner base particles are likely to adhere with the temperature adjusting jacket, the toner base particles can be more reliably prevented from adhering to the inner wall of the powder flow path 202.

[Resin fine particle adhesion step S3b]
In the resin fine particle attaching step in step S3b, the resin fine particles are attached to the surface of the toner base particles. Specifically, the toner base particles and the resin fine particles are supplied from the powder input unit 206 into the powder flow path 202 adjusted to a predetermined temperature and rotating the rotation shaft 218 of the rotary stirring unit 204. The toner base particles and resin fine particles supplied to the powder flow path 202 are stirred by the rotary stirring means 204 and flow in the direction of arrow 214 through the powder flow section 209 of the powder flow path 202. As a result, the resin fine particles adhere to the surface of the toner base particles.

[Spraying step S3c]
In the spraying step of step S3c, a spray liquid that does not dissolve the toner base particles and the resin fine particles but has a plasticizing effect is sprayed from the spray means to the toner base particles in a fluid state in which the resin fine particles adhere to the surface. Spraying of the spray liquid is preferably started after the surface of the toner base particles and the flow rate of the resin fine particles are stabilized in the powder flow path 202. In this way, since the spray liquid can be uniformly sprayed on the toner base particles and the resin fine particles, the yield of the toner uniformly coated with the coating layer can be improved.

  The spray liquid is fed to the spray means at a constant flow rate by a liquid feed pump. The sprayed liquid sprayed from the spraying means is gasified in a sufficiently fast time in the powder flow path, and the gasified sprayed liquid spreads on the surface of the toner base particles to which the resin fine particles are adhered. As a result, the toner base particles and the resin fine particles are plasticized. In the powder flow path 202, the gasified spray liquid and other gas such as carrier gas are present in a mixed state.

  Since the spray liquid needs to be removed from the toner base particles and the resin fine particles after spraying, a spray liquid having a low boiling point and being easily vaporized is used. As the spray liquid that is easily vaporized and has the effect of plasticizing the toner base particles and the resin fine particles without dissolving them, an organic solvent that gasifies in a sufficiently fast time is used. Explosive limit concentrations are known in methods for managing and operating these gasified organic solvents. This indicates a range where explosion occurs when air and a vaporized organic solvent are mixed, and the lower limit of explosion is called LEL concentration. In the present embodiment, this LEL concentration is treated as a volume-specific concentration and is characteristic of the gas vaporized by the organic solvent. Normally, the LEL concentration indicates the range that explodes when mixed with air. However, in this embodiment, the LEL concentration is used as a value indicating the limit volume concentration inherent to the gas, and similarly when mixed with a non-explosive gas such as nitrogen. Treated as a gas-specific LEL concentration.

  Examples of such an organic solvent include a liquid containing a lower alcohol. Examples of the lower alcohol include methanol, ethanol, propanol, butanol and the like. Among these, tertiary or lower alcohols are preferable. When the spray liquid contains such a lower alcohol, the wettability of the resin fine particles as the coating material to the toner mother particles can be improved, and the resin fine particles are attached to the entire surface or most of the toner mother particles to be deformed. And it becomes easy to form a film. In addition, since the lower alcohol has a low viscosity and a high vapor pressure, the drying time when removing the spray liquid can be further shortened. Further, spraying with a fine droplet diameter and spraying with a uniform droplet diameter are possible without coarsening the droplet diameter of the spray liquid when sprayed from the spraying means 203. When the toner base particles collide with the liquid droplets, the micronization of the liquid droplets is further promoted, so that the surface of the toner base particles and the resin fine particles are uniformly wetted and blended, and the resin fine particles are softened by a synergistic effect with the collision energy. In addition, a toner having excellent uniformity can be obtained. The viscosity of the spray liquid is measured at 25 ° C. The viscosity of the liquid can be measured by, for example, a cone plate type rotary viscometer.

  The spray liquid is preferably an alcohol having an LEL concentration of 1.7 vol% or more and 6.7 vol% or less when gasified. Alcohol having an LEL concentration lower than 1.7% by volume is too low in the ability to plasticize the toner base particles and resin fine particles, and the formation of resin fine particles on the surface of the toner base particles does not proceed favorably, and is required for film formation. The time is too long. For this reason, deformation of the toner particles and aggregation between the toner particles are caused, and it becomes impossible to obtain a toner having a desired shape and particle diameter with high yield. In addition, when an alcohol having a LEL concentration higher than 6.7% by volume is used, the toner base particles and the resin fine particles are too plasticized, and the toner base particles or the resin fine particles are fixed or aggregated. As a result, a toner having a desired particle size cannot be obtained in a high yield.

  Since the sprayed liquid sprayed from the spraying means is gasified in the powder flow path 202, the operation of spraying the spray liquid into the powder flow path 202 and discharging it out of the powder flow path 202 by air is sufficient. When performed over time, the gas concentration of the gasified spray liquid (hereinafter also referred to as “liquid gas”) becomes constant in the powder flow path 202. In this step and the film forming step S3d described later, in order to sufficiently plasticize the toner base particles and the resin fine particles, the gas concentration in the powder flow path 202 needs to be constant. In addition, by keeping the gas concentration in the powder flow path 202 constant, the drying speed of the spray liquid can be increased compared with the case where the gas concentration is not kept, so that the toner particles in which the undried liquid remains are other than that. Adhesion to the toner particles can be prevented, and aggregation of the toner particles can be further suppressed. Therefore, the yield of the toner uniformly coated with the coating layer can be further improved. The air containing the liquid gas and the carrier gas is discharged out of the powder flow path 202 through the gas discharge unit 222.

In this embodiment, the two spraying means 203 of the 1st spraying means 203a and the 2nd spraying means 203b are used, and spraying is performed over the whole this process in the 1st spraying means 203a. From the second spraying means 203b, in addition to the spraying from the first spraying means 203a, the spraying is performed from the start of the spraying until the additional spraying time T1 that satisfies the following formula (1). At that time, from the second spraying means 203b, an additional amount of the spray liquid that becomes the additional gas volume K satisfying the following formula (2) is sprayed into the powder flow path.
0.2τ ≦ T1 ≦ τ (τ = V / Fair) (1)
0.6κ ≦ K ≦ 1.6κ (κ = (Fin / Fair) × V) (2)

  Fin indicates the gas volume flow rate obtained from the volume when the spray liquid is gasified. This volume varies depending on the type of spray liquid. The gas volume flow rate is obtained by multiplying the spray rate of the spray liquid sprayed from the first spray means 203a into the powder flow path by the volume amount of the spray liquid gasified. In the present embodiment, the spray speed is calculated from the average spray amount per hour. Spraying may be performed intermittently or continuously. However, if the flow rate of the spray liquid is controlled by adjusting the flow rate of the spray liquid with a fixed pump, etc. Simple. Fair indicates the air volume flow rate of the air discharged from the powder flow path, and V indicates the volume in the powder flow path. The volume of the spray liquid gasified (hereinafter also referred to as “gasification volume”) is obtained by dividing the weight of the spray liquid by the molecular weight of the molecules constituting the spray liquid and multiplying by 22.4 L. The additional gas volume K is obtained by multiplying the spray amount of the spray liquid from the second spray means 203b by the gasification volume. Note that the spray liquid sprayed from the second spraying means 203b may be in a mist or gasified state.

  The reason for using the two spraying means 203 of the 1st spraying means 203a and the 2nd spraying means 203b is described below.

When spraying a certain amount of spray liquid using one spraying means, the time change of the gas concentration D in the powder channel is expressed by the following equation (5) using the volume V of the powder channel. Can be expressed as:
V (dD / dt) = Fin−D × Fair (5)

When a sufficient amount of time has elapsed since the start of spraying, the amount of gas supplied and the amount of gas discharged are balanced, so that the gas concentration D in the powder flow path does not change with time and is constant. (Left side) = 0. If the gas concentration at this time is D∞,
D∞ = Fin / Fair (6)
It becomes. That is, the supply amount and discharge amount of the liquid gas are constant. The left side represents the time change of the liquid gas amount (VD) stored in the powder flow path 202. The next value represented by the gas concentration D∞ and the volume V of the powder channel is represented as the gas quantity κ in the powder channel.
κ = D∞ × V

Here, in solving the time differential equation of the above equation (5), the following equation (7) is assumed using the variable A, the variable B, and the variable τ.
D = A × exp (−t / τ) + B (7)

Variables are determined so that Equation (7) satisfies the initial condition and Equation (5).
First, when time t is infinite, since D converges to D∞, the following equation (7a) is obtained.
B = D∞ (7a)

Next, when time t is 0, since D = 0, the following equation (7b) is obtained.
0 = A + B
A = -B (7b)

Substituting equations (7a) and (7b) into equation (7) leads to the following theoretical equation (8).
D = D∞ {1-exp (−t / τ)} (8)

  A differential equation of Expression (8) is obtained, and the speed of collection time τ is determined by comparing the coefficient with Expression (5) above.

Solving for exp (−t / τ) of equation (8), the following equation (8a) is obtained.
exp (−t / τ) = 1− (D / D∞) (8a)

When the gas concentration D in the equation (8a) is differentiated with respect to time t, the following equation (8b) is obtained.
(DD / dt) = (D∞ / τ) exp (−t / τ) (8b)

By substituting equation (8a) into equation (8b) to eliminate exp (−t / τ) and multiplying both sides by the powder flow path volume V, V (dD / dt) is summarized as the following equation (9 ) Is required.
V (dD / dt) = V (D∞ / τ) {1- (D / D∞)} (9)

The coefficient of the equation (9) is compared with the coefficient of the above equation (5).
Since Expression (5) is V (dD / dt) = Fin−D × Fair, the following Expressions (10) and (11) are derived.

For a term related to the gas concentration D, −V (D∞ / τ) × (D / D∞) = − D × Fair
…(Ten)
For terms not related to gas concentration D, V (D∞ / τ) = Fin (11)
When the equation (10) is calculated, the following equation (10a) is obtained.
τ = V / Fair (10a)

Substituting equation (10a) into equation (11) yields equation (6).
D∞ = (Fin / V) τ = (Fin / Fair)

  Therefore, it is shown that the above formula (8) D = D∞ {1-exp (−t / τ)} is the solution of the above formula (5).

  However, the theoretical formula (8) is different from the actual gas concentration, and it always takes a longer time than the theoretical formula (8) until the gas concentration becomes constant. This deviation is mainly caused by spraying the spray liquid toward the particles, so that the spray liquid is trapped on the surface and inside of the particles such as toner base particles and does not evaporate, or it takes time to evaporate. it is conceivable that. However, a sufficient time has elapsed since the start of spraying, and the gas concentration at the time of convergence almost coincides with D∞ in the theoretical formula (8).

  When the size of the toner manufacturing apparatus is increased, as can be seen from the theoretical formula (8) and the like, since the powder flow path volume V increases, the convergence time τ becomes longer. A longer time is required to keep the gas concentration in the flow path constant. In particular, when a certain amount of spray liquid is sent and gasified by a pump as described above, the gasification concentration in the powder flow path is not stable, and the effective concentration necessary for processing cannot be obtained immediately. If so, deformation of the shape of the toner particles and aggregation between the toner particles are caused, and a desired toner cannot be obtained.

  The spray amount of the spray liquid necessary for making the gas concentration in the powder flow path constant varies depending on the apparatus size, the target spray concentration, the spray time, the processing amount, etc., but in the spray process, the first spray means 203a. In addition to spraying by the above, the amount of spray liquid necessary to quickly bring the gas concentration in the powder channel to the desired concentration is added by the second spraying means 203b according to the device size, that is, the volume in the powder channel. By supplying, the gas concentration in the powder channel can be made close to the theoretical formula (8) to improve the rising of the gas concentration, and the film can be formed in a short time. Shape deformation and aggregation between toner particles can be suppressed. Further, since the resin fine particles can be uniformly formed on the surface of the toner base particles, the film quality can be improved. By producing the toner by such a method, the generation of coarse particles can be suppressed, and a toner having good film quality can be stably obtained. In the present invention, the spray amount of the spray liquid is changed in the middle of the spraying step S3c. By using two spraying means in this way, the spray amount of the spray liquid can be easily controlled.

  In addition, the material selectivity of the toner base particles and resin fine particles is wide, and the degree of freedom in designing the charging characteristics and fluidity of the toner is large, and the storage stability is also obtained when a low melting point material is used for the toner base particles. A toner that does not deteriorate can be produced stably.

  An angle θ formed by the liquid spray direction which is the direction of the axis of the two-fluid nozzle 205 and the powder flow direction which is the direction in which the toner base particles and the resin fine particles flow in the powder flow path 202 is 0 ° or more and 45 ° or less. Is preferred. When θ is within such a range, the spray liquid droplets are prevented from recoiling at the inner wall of the powder flow path, and the yield of toner mother particles coated with the resin film can be further improved. . When the angle θ exceeds 45 °, the droplets of the spray liquid are likely to recoil on the inner wall of the powder flow path, and the spray liquid tends to stay, causing toner particles to aggregate and the yield to deteriorate.

  The spreading angle φ of the liquid sprayed by the spraying means 203 is preferably 20 ° or more and 90 ° or less. If the spread angle φ is out of this range, it may be difficult to uniformly spray the spray liquid onto the toner base particles.

  The concentration of the liquid gas measured by the concentration sensor in the gas discharge unit 222 is preferably about 3%. Since the liquid gas concentration is about 3%, the drying time of the spray liquid can be shortened, so that the undried toner particles in which the spray liquid remains are further prevented from adhering to other toner particles. And aggregation of toner particles can be prevented. Further, the concentration of the liquid gas in the gas discharge unit 222 is more preferably 0.1% or more and 3.0% or less by the concentration sensor. When the spraying speed is in such a range, the aggregation of toner particles can be further prevented without lowering the productivity.

Instead of using two spraying means as in this embodiment, only one spraying means is used, and during the increased spraying time T2 that satisfies the following expression (3) from the start of spraying by the spraying means, the following expression (4) The object of the present invention can also be achieved by increasing the amount of spray from the spraying means by an amount that provides an increased gas volume k that satisfies the above.
0.2τ ≦ T2 ≦ τ (τ = V / Fair) (3)
0.6κ ≦ k ≦ 1.6κ (κ = (Fin / Fair) × V) (4)

  Fin indicates a gas volume flow rate obtained by multiplying the spray rate when the spray liquid is sprayed into the powder channel without increasing by the volume amount when the spray liquid is gasified. Fair indicates the air volume flow rate of the air discharged from the powder flow path, and V indicates the volume in the powder flow path. The increased gas volume k is obtained by multiplying the increased spray amount of the spray liquid by the gasification volume.

[Film forming step S3d]
In the film forming step of step S3d, while spraying the spray liquid, the resin fine particles are softened by the synergistic effect of the circulation by the toner manufacturing apparatus 201 and the impact force by the stirring, and the thermal energy by the stirring to form a continuous film. Then, stirring of the rotary stirring means 204 is continued at a predetermined temperature until a resin film is formed on the toner base particles, and the toner base particles and resin fine particles are repeatedly circulated in the powder flow path.

[Recovery step S3e]
In the recovery step of step S3e, the spraying of the spray liquid is terminated, the rotation of the rotary stirring unit 204 is stopped, and the toner with the resin film formed on the surface of the toner base particles is discharged from the powder recovery unit 207 to the outside of the apparatus. ,to recover.

  As described above, the toner of the present invention is manufactured. In the covering step S3 including steps S3a to S3e, the peripheral speed of the outermost periphery of the rotary stirring means 204 is preferably set to 30 m / sec or more. More preferably, it is set to 50 m / sec or more. When the peripheral speed at the outermost periphery of the rotary stirring means 204 is 30 m / sec or more, the toner base particles can be isolatedly flowed. If the peripheral speed at the outermost periphery is less than 30 m / sec, the toner base particles and the resin fine particles cannot be isolatedly flowed, so that the toner base particles cannot be uniformly coated with the resin film.

  In the coating step S3, the temperature in the powder flow path 202 is preferably set to be equal to or lower than the glass transition temperature of the toner base particles, and more preferably from 30 ° C. to the glass transition temperature of the toner base particles. When the temperature in the powder flow path 202 exceeds the glass transition temperature of the toner base particles, the toner base particles are too soft in the powder flow path 202, and the toner base particles may be aggregated. On the other hand, if the temperature in the powder flow path 202 is lower than 30 ° C., the drying speed of the dispersion may be slowed and productivity may be reduced. Therefore, in order to prevent the aggregation of the toner base particles, the inner diameter is larger than the outer diameter of the powder passage tube in order to keep the temperature of the powder flow path 202 and the rotating stirring means below the glass transition temperature of the toner base particles. It is necessary to dispose a temperature adjusting jacket on at least a part of the outside of the powder channel tube and the rotary stirring means 204, and to provide a device having a function of adjusting the temperature through a cooling medium or a heating medium in the space. is there. Note that the temperature in the powder flow path 202 becomes substantially uniform in any part of the powder flow path 202 due to the flow of the toner base particles.

  As described above, the rotating stirring unit 204 includes the rotating disk 219 that rotates as the rotating shaft 218 rotates, but the toner base particles and the resin fine particles preferably collide perpendicularly with the rotating disk 219. It is more preferable to collide with the rotating shaft 218 perpendicular to the rotating disk 219. As a result, the toner base particles and the resin fine particles can be sufficiently stirred rather than the toner base particles and the resin fine particles colliding with the rotating disk 219 in parallel, so that the toner base particles are more uniformly coated with the resin fine particles. And the yield of the toner with the coating layer uniformly coated can be further improved.

  The toner manufacturing apparatus 201 is not limited to the above configuration, and various modifications can be made. For example, the temperature adjustment jacket may be provided on the entire surface outside the powder flow part 209 and the stirring part 208, or may be provided on a part of the powder flow part 208 or a part outside the stirring part 208. . If a temperature adjustment jacket is provided on the entire surface outside the powder flow section 209 and the stirring section 208, it is possible to more reliably prevent toner base particles from adhering to the inner wall of the powder flow path 202.

  The toner manufacturing apparatus 201 can also be obtained by combining a commercially available stirring apparatus and spraying means. As a commercially available stirring apparatus provided with a powder flow path and rotating stirring means, for example, a hybridization system (trade name, manufactured by Nara Machinery Co., Ltd.) and the like can be mentioned. By mounting the liquid spray unit in such a stirring device, this stirring device can be used as a toner manufacturing apparatus used in the toner manufacturing method of the present invention.

2. Toner The toner according to the second embodiment of the present invention is manufactured by the toner manufacturing method according to the first embodiment. The toner produced by the production method of the present invention has no coarse particles and good film quality. Even if a low melting point material is used for the toner base particles, the storage stability is good. By forming an image using such a toner, a good toner image can be formed over a long period of time.

  An external additive may be added to the toner of the present invention. Known external additives can be used, and examples thereof include silica and titanium oxide. These are preferably surface-treated with a silicone resin, a silane coupling agent or the like. The amount of the external additive used is preferably 1 to 10 parts by weight with respect to 100 parts by weight of the toner.

3. Developer The developer according to the third embodiment of the present invention includes the toner according to the second embodiment. Since the toner of the present invention does not deteriorate the storage stability even when toner base particles having a low melting point are used for fixing at a low temperature, the developer of this embodiment can be developed even when used in a high temperature atmosphere. The deterioration of fluidity in the tank is reduced, and good developability can be secured over a long period of time.

  The developer of this embodiment can be used as a one-component developer or a two-component developer. When used as a one-component developer, the toner is used alone without using a carrier. When used as a one-component developer, a blade and a fur brush are used, and the toner is conveyed by friction charging with a developing sleeve to adhere the toner onto the sleeve, thereby forming an image.

  When used as a two-component developer, the toner of the present invention is used with a carrier. Since the toner of the present invention does not deteriorate the storage stability even when low melting point toner base particles are used for fixing at low temperature, the two-component developer of the present invention has the ability to impart charge by toner spent on the carrier. Can be prevented, and good developability can be ensured over a long period of time.

(Career)
As the carrier, a known carrier can be used, for example, a single or composite ferrite composed of iron, copper, zinc, nickel, cobalt, manganese, chromium, etc., a resin-coated carrier whose carrier core particles are coated with a coating substance, and a resin And a resin-dispersed carrier in which magnetic particles are dispersed. Known coating materials can be used, such as polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicone resin, polyester resin, metal compound of ditertiary butylsalicylic acid, styrene resin, acrylic resin , Polyamide, polyvinyl butyral, nigrosine, amino acrylate resin, basic dye, basic dye lake, silica fine powder, alumina fine powder, and the like. Moreover, although it does not restrict | limit especially as resin used for a resin dispersion type carrier, For example, a styrene acrylic resin, a polyester resin, a fluorine resin, a phenol resin, etc. are mentioned. Both are preferably selected according to the toner component, and one type can be used alone or two or more types can be used in combination.

The shape of the carrier is preferably a spherical shape or a flat shape. The particle size of the carrier is not particularly limited, but is preferably 10 to 100 μm, more preferably 20 to 50 μm, considering high image quality. Furthermore, the resistivity of the carrier is preferably 10 ⁸ Ω · cm or more, more preferably 10 ¹² Ω · cm or more.

The volume resistivity of the carrier is determined by putting the carrier in a container having a cross-sectional area of 0.50 cm ² and tapping, then applying a load of 1 kg / cm ² with the weight of the particles packed in the container, It is a value obtained by reading a current value when a voltage generating an electric field of 1000 V / cm is applied between the two. When the volume resistivity is low, when a bias voltage is applied to the developing sleeve, charges are injected into the carrier, and carrier particles easily adhere to the photoreceptor. Further, breakdown of the bias voltage is likely to occur.

  The magnetization strength (maximum magnetization) of the carrier is preferably 10 to 60 emu / g, more preferably 15 to 40 emu / g. The magnetization strength depends on the magnetic flux density of the developing roller, but under the general magnetic flux density conditions of the developing roller, if it is less than 10 emu / g, the magnetic binding force does not work and causes carrier scattering. There is a fear. On the other hand, if the magnetization strength exceeds 60 emu / g, the rising of the carrier becomes too high, so that it is difficult to maintain the non-contact state with the image carrier in the non-contact development. Further, in the contact development, there is a risk that a sweep is likely to appear in the toner image.

  The use ratio of the toner and the carrier in the two-component developer is not particularly limited and can be appropriately selected according to the kind of the toner and the carrier. However, if a resin-coated carrier (density 5 to 8 g / cm 2) is taken as an example, the developer The toner may be used so that the toner is contained in an amount of 2 to 30% by weight, preferably 2 to 20% by weight, based on the total amount of the developer. In the two-component developer, the carrier coverage with the toner is preferably 40 to 80%.

4. Image Forming Apparatus FIG. 5 is a cross-sectional view schematically showing a configuration of an image forming apparatus 100 according to the fourth embodiment of the present invention. The image forming apparatus 100 is a multifunction machine having both a copying function, a printer function, and a facsimile function, and forms a full-color or monochrome image on a recording medium in accordance with transmitted image information. That is, the image forming apparatus 100 has three types of printing modes, ie, a copier mode (copying mode), a printer mode, and a FAX mode. Operation input from an operation unit (not shown), personal computer, portable terminal device, information A print mode is selected by a control unit (not shown) in response to reception of a print job from an external device using a recording storage medium or a memory device.

  The image forming apparatus 100 includes a photosensitive drum 11 that is an image carrier, an image forming unit 2, a transfer unit 3, a fixing unit 4, a recording medium supply unit 5, and a discharge unit 6. Each member constituting the image forming unit 2 and some members included in the transfer unit 3 are black (b), cyan (c), magenta (m) and yellow (y) included in the color image information. In order to correspond to image information, four each are provided. Here, each member provided by four according to each color is distinguished by attaching an alphabet representing each color to the end of the reference symbol, and when referring collectively, only the reference symbol is used.

  The image forming unit 2 includes a charging unit 12, an exposure unit 13, a developing device 14, and a cleaning unit 15. The charging unit 12 and the exposure unit 13 function as a latent image forming unit. The charging unit 12, the developing device 14, and the cleaning unit 15 are arranged around the photosensitive drum 11 in this order. The charging unit 12 is disposed below the developing device 14 and the cleaning unit 15 in the vertical direction.

The photosensitive drum 11 is a roller-like member that is provided so as to be rotatable about an axis by a rotation driving unit (not shown), and on which an electrostatic latent image is formed. The rotation driving means of the photosensitive drum 11 is controlled by a control means realized by a central processing unit (CPU). The photosensitive drum 11 includes a conductive substrate (not shown) and a photosensitive layer (not shown) formed on the surface of the conductive substrate. The conductive substrate can take various shapes, and examples thereof include a cylindrical shape, a columnar shape, and a thin film sheet shape. Among these, a cylindrical shape is preferable. The conductive substrate is formed of a conductive material.

  As the conductive material, those commonly used in this field can be used. For example, metals such as aluminum, copper, brass, zinc, nickel, stainless steel, chromium, molybdenum, vanadium, indium, titanium, gold, platinum, etc. A conductive layer made of one or more of aluminum, aluminum alloy, tin oxide, gold and indium oxide is formed on a film-like substrate such as two or more alloys, synthetic resin film, metal film or paper. And a resin composition containing conductive particles and / or a conductive polymer. As the film-like substrate used for the conductive film, a synthetic resin film is preferable, and a polyester film is particularly preferable. Moreover, as a formation method of the electroconductive layer in an electroconductive film, vapor deposition, application | coating, etc. are preferable.

  The photosensitive layer is formed, for example, by laminating a charge generation layer containing a charge generation material and a charge transport layer containing a charge transport material. In that case, it is preferable to provide an undercoat layer between the conductive substrate and the charge generation layer or the charge transport layer. By providing an undercoat layer, it is possible to cover the scratches and irregularities present on the surface of the conductive substrate, smooth the surface of the photosensitive layer, and prevent deterioration of the chargeability of the photosensitive layer during repeated use. And / or the advantage of improving the charging characteristics of the photosensitive layer in a low humidity environment can be obtained. Further, a laminated photoreceptor having a three-layer structure having a high durability and having a photoreceptor surface protective layer as the uppermost layer may be used.

  The charge generation layer is mainly composed of a charge generation material that generates a charge when irradiated with light, and contains a known binder resin, plasticizer, sensitizer and the like as necessary. As the charge generation material, those commonly used in this field can be used, for example, perylene pigments such as perylene imide and perylene acid anhydride, polycyclic quinone pigments such as quinacridone and anthraquinone, metal and metal-free phthalocyanines, and halogenated compounds. Phthalocyanine pigments such as metal-free phthalocyanine, squalium dye, azulenium dye, thiapyrylium dye, carbazole skeleton, styryl stilbene skeleton, triphenylamine skeleton, dibenzothiophene skeleton, oxadiazole skeleton, fluorenone skeleton, bis-stilbene skeleton, distyryl And azo pigments having an oxadiazole skeleton or a distyrylcarbazole skeleton. Among these, metal-free phthalocyanine pigments, oxotitanyl phthalocyanine pigments, bisazo pigments containing a fluorene ring and / or a fluorenone ring, bisazo pigments composed of aromatic amines, trisazo pigments, etc. have high charge generation ability and high sensitivity. Suitable for obtaining a photosensitive layer. One type of charge generating material can be used alone, or two or more types can be used in combination. Although the content of the charge generation material is not particularly limited, it is preferably 5 parts by weight or more and 500 parts by weight or less, more preferably 10 parts by weight or more and 200 parts by weight or less with respect to 100 parts by weight of the binder resin in the charge generation layer. is there. As the binder resin for the charge generation layer, those commonly used in this field can be used. For example, melamine resin, epoxy resin, silicone resin, polyurethane, acrylic resin, vinyl chloride-vinyl acetate copolymer resin, polycarbonate, phenoxy resin , Polyvinyl butyral, polyarylate, polyamide and polyester. Binder resin can be used individually by 1 type, or can use 2 or more types together as needed.

  The charge generation layer generates charge by dissolving or dispersing appropriate amounts of charge generation materials, binder resins and, if necessary, plasticizers and sensitizers in an appropriate organic solvent that can dissolve or disperse these components. It can be formed by preparing a layer coating solution, applying this charge generation layer coating solution to the surface of the conductive substrate, and drying the surface of the conductive substrate. The film thickness of the charge generation layer thus obtained is not particularly limited, but is preferably 0.05 μm or more and 5 μm or less, more preferably 0.1 μm or more and 2.5 μm or less.

  The charge transport layer laminated on the charge generation layer has a charge transport material having the ability to accept and transport the charge generated from the charge generation material and a binder resin for the charge transport layer as essential components. Contains known antioxidants, plasticizers, sensitizers, lubricants and the like. As the charge transport material, those commonly used in this field can be used, for example, poly-N-vinylcarbazole and its derivatives, poly-γ-carbazolylethyl glutamate and its derivatives, pyrene-formaldehyde condensate and its derivatives, Polyvinylpyrene, polyvinylphenanthrene, oxazole derivatives, oxadiazole derivatives, imidazole derivatives, 9- (p-diethylaminostyryl) anthracene, 1,1-bis (4-dibenzylaminophenyl) propane, styrylanthracene, styrylpyrazoline, pyrazoline Derivatives, phenylhydrazones, hydrazone derivatives, triphenylamine compounds, tetraphenyldiamine compounds, triphenylmethane compounds, stilbene compounds, 3-methyl-2-benzothiazoli Electron donating substances such as azine compounds having a ring, fluorenone derivatives, dibenzothiophene derivatives, indenothiophene derivatives, phenanthrenequinone derivatives, indenopyridine derivatives, thioxanthone derivatives, benzo [c] cinnoline derivatives, phenazine oxide derivatives, tetra And electron accepting substances such as cyanoethylene, tetracyanoquinodimethane, promanyl, chloranil, and benzoquinone. The charge transport materials can be used alone or in combination of two or more. Although the content of the charge transport material is not particularly limited, it is preferably 10 parts by weight or more and 300 parts by weight or less, more preferably 30 parts by weight or more and 150 parts by weight or less with respect to 100 parts by weight of the binder resin in the charge transport material. .

  As the binder resin for the charge transport layer, those commonly used in this field and capable of uniformly dispersing the charge transport material can be used. For example, polycarbonate, polyarylate, polyvinyl butyral, polyamide, polyester, polyketone, epoxy resin, polyurethane , Polyvinyl ketone, polystyrene, polyacrylamide, phenol resin, phenoxy resin, polysulfone resin, and copolymer resins thereof. Among these, in consideration of film formability, wear resistance of the resulting charge transport layer, electrical characteristics, etc., polycarbonate containing bisphenol Z as a monomer component (hereinafter referred to as “bisphenol Z type polycarbonate”), bisphenol Z type polycarbonate A mixture of and other polycarbonates is preferred. Binder resin can be used individually by 1 type, or can use 2 or more types together.

  The charge transport layer preferably contains an antioxidant together with the charge transport material and the binder resin for the charge transport layer. As the antioxidant, those commonly used in this field can be used, and examples thereof include vitamin E, hydroquinone, hindered amine, hindered phenol, paraphenylenediamine, arylalkane and derivatives thereof, organic sulfur compounds, and organic phosphorus compounds. It is done. One antioxidant can be used alone, or two or more antioxidants can be used in combination. The content of the antioxidant is not particularly limited, but is 0.01% by weight or more and 10% by weight or less, preferably 0.05% by weight or more and 5% by weight or less of the total amount of components constituting the charge transport layer.

  The charge transport layer is dissolved or dispersed in a suitable organic solvent capable of dissolving or dispersing these components, such as a charge transport material, a binder resin, and if necessary, an antioxidant, a plasticizer, and a sensitizer. The charge transport layer coating liquid is prepared, the charge transport layer coating liquid is applied to the surface of the charge generation layer, and the charge generation layer surface is dried. The film thickness of the charge transport layer thus obtained is not particularly limited, but is preferably 10 μm or more and 50 μm or less, more preferably 15 μm or more and 40 μm or less.

  A photosensitive layer in which a charge generation material and a charge transport material are present can be formed in one layer. In that case, the type, content, binder resin, and other additives of the charge generation material and the charge transport material may be the same as in the case of separately forming the charge generation layer and the charge transport layer.

  In this embodiment, the photosensitive drum formed by forming the organic photosensitive layer using the charge generation material and the charge transport material as described above is used. Instead, an inorganic photosensitive layer using silicon or the like is formed. A photosensitive drum can be used.

  The charging unit 12 faces the photosensitive drum 11 and is arranged so as to be separated from the surface of the photosensitive drum 11 along the longitudinal direction of the photosensitive drum 11 with a gap, and the surface of the photosensitive drum 11 has a predetermined polarity and Charge to potential. As the charging unit 12, a charging brush type charger, a charger type charger, a sawtooth type charger, an ion generator, or the like can be used. In the present embodiment, the charging unit 12 is provided so as to be separated from the surface of the photosensitive drum 11, but is not limited thereto. For example, a charging roller may be used as the charging unit 12, and the charging roller may be arranged so that the charging roller and the photosensitive drum are in pressure contact with each other, or a contact charging type charger such as a charging brush or a magnetic brush may be used. .

  The exposure unit 13 is arranged such that light of each color information emitted from the exposure unit 13 passes between the charging unit 12 and the developing device 14 and is irradiated on the surface of the photosensitive drum 11. The exposure unit 13 branches the image information into light of each color information of black, cyan, magenta, and yellow in the unit, and the surface of the photosensitive drum 11 charged to a uniform potential by the charging unit 12 is light of each color information. To form an electrostatic latent image on the surface. As the exposure unit 13, for example, a laser scanning unit including a laser irradiation unit and a plurality of reflecting mirrors can be used. In addition, a unit in which an LED array or a liquid crystal shutter and a light source are appropriately combined may be used.

  The cleaning unit 15 uses the developing device 14 to transfer the toner image formed on the surface of the photosensitive drum 11 to a recording medium, and then removes the toner remaining on the surface of the photosensitive drum 11 to remove the surface of the photosensitive drum 11. Clean. For the cleaning unit 15, for example, a plate-like member such as a cleaning blade is used. In the image forming apparatus of the present embodiment, an organic photosensitive drum is used as the photosensitive drum 11, and the surface of the organic photosensitive drum is mainly composed of a resin component, and thus is generated by corona discharge by a charging device. Deterioration of the surface of the organic photosensitive drum is likely to proceed due to the chemical action of ozone. However, the deteriorated surface portion is worn by receiving a rubbing action by the cleaning unit 15 and the gradually deteriorated surface portion is surely removed. Therefore, the problem of surface deterioration due to ozone or the like is practically solved, and the charging potential by the charging operation can be stably maintained over a long period of time. Although the cleaning unit 15 is provided in this embodiment, the present invention is not limited to this, and the cleaning unit 15 may not be provided.

  According to the image forming unit 2, the surface of the photosensitive drum 11 that is uniformly charged by the charging unit 12 is irradiated with signal light according to image information from the exposure unit 13 to form an electrostatic latent image. Then, the toner is supplied from the developing device 14 to form a toner image. After the toner image is transferred to the intermediate transfer belt 25, the toner remaining on the surface of the photosensitive drum 11 is removed by the cleaning unit 15. This series of toner image forming operations is repeatedly executed to form an image.

  The transfer means 3 is arranged above the photosensitive drum 11 and has four intermediate portions corresponding to the intermediate transfer belt 25, the drive roller 26, the driven roller 27, and the image information of each color of black, cyan, magenta and yellow. A transfer roller 28, a transfer belt cleaning unit 29, and a transfer roller 30 are included. The intermediate transfer belt 25 is an endless belt-like member that is stretched around a driving roller 26 and a driven roller 27 to form a loop-shaped movement path, and is driven to rotate in the direction of an arrow B. The driving roller 26 is provided so as to be rotatable around its axis by driving means (not shown), and the intermediate transfer belt 25 is driven to rotate in the direction of arrow B by the rotational driving. The driven roller 27 is provided so as to be able to be driven and rotated by the rotational drive of the driving roller 26, and applies a certain tension to the intermediate transfer belt 25 so that the intermediate transfer belt 25 does not loosen. The intermediate transfer roller 28 is provided in pressure contact with the photosensitive drum 11 via the intermediate transfer belt 25 and capable of being driven to rotate about its axis by a driving unit (not shown). The intermediate transfer roller 28 is connected to a power source (not shown) for applying a transfer bias as described above, and has a function of transferring the toner image on the surface of the photosensitive drum 11 to the intermediate transfer belt 25.

  When the intermediate transfer belt 25 passes through the photoconductive drum 11 while being in contact with the photoconductive drum 11, the toner on the surface of the photoconductive drum 11 is transferred from the intermediate transfer roller 28 disposed opposite to the photoconductive drum 11 through the intermediate transfer belt 25. A transfer bias having a polarity opposite to the charging polarity is applied, and the toner image formed on the surface of the photosensitive drum 11 is transferred to the intermediate transfer belt 25. In the case of a full-color image, each color toner image formed on each photoconductor drum 11 is sequentially transferred onto the intermediate transfer belt 25 to form a full-color toner image.

  The transfer belt cleaning unit 29 is provided so as to face the driven roller 27 through the intermediate transfer belt 25 and to contact the outer peripheral surface of the intermediate transfer belt 25. The toner adhering to the intermediate transfer belt 25 due to contact with the photosensitive drum 11 causes the recording medium to be contaminated. Therefore, the transfer belt cleaning unit 29 removes and collects the toner on the surface of the intermediate transfer belt 25.

  The transfer roller 30 is provided in pressure contact with the drive roller 26 via the intermediate transfer belt 25, and can be driven to rotate about an axis by a drive unit (not shown). The toner image carried on the intermediate transfer belt 25 and conveyed at the pressure contact portion between the transfer roller 30 and the driving roller 26, that is, the transfer nip portion, is transferred to a recording medium fed from a recording medium supply means 5 described later. The The recording medium carrying the toner image is fed to the fixing unit 4.

  According to the transfer unit 3, the toner image transferred from the photosensitive drum 11 to the intermediate transfer belt 25 at the pressure contact portion between the photosensitive drum 11 and the intermediate transfer roller 28 rotates the intermediate transfer belt 25 in the arrow B direction. It is conveyed to a transfer nip portion by driving, and transferred to a recording medium there.

  The fixing unit 4 is provided downstream of the transfer unit 3 in the conveyance direction of the recording medium, and includes a fixing roller 31 and a pressure roller 32. The fixing roller 31 is rotatably provided by a driving unit (not shown), and fixes an unfixed toner image carried on the recording medium to the recording medium by heating and melting the constituent toner. A heating unit (not shown) is provided inside the fixing roller 31. The heating unit heats the fixing roller 31 so that the surface of the fixing roller 31 reaches a predetermined temperature (hereinafter also referred to as “heating temperature”). For example, a heater or a halogen lamp can be used as the heating means. The heating means is controlled by fixing condition control means described later. The control of the heating temperature by the fixing condition control means will be described in detail later.

  A temperature detection sensor (not shown) is provided near the surface of the fixing roller 31, and the temperature detection sensor detects the surface temperature of the fixing roller 31. The detection result by the temperature detection sensor is written in the storage unit of the control means described later. The pressure roller 32 is provided so as to be in pressure contact with the fixing roller 31 and is supported so as to be driven to rotate by the rotation drive of the pressure roller 32. When the toner is melted by heat from the fixing roller 31 and the toner image is fixed on the recording medium, the pressure roller 32 presses the toner and the recording medium to assist the fixing of the toner image onto the recording medium. A pressure contact portion between the fixing roller 31 and the pressure roller 32 is a fixing nip portion.

  According to the fixing unit 4, the recording medium onto which the toner image is transferred by the transfer unit 3 is sandwiched between the fixing roller 31 and the pressure roller 32, and the toner image is recorded under heating when passing through the fixing nip portion. By being pressed against the medium, the toner image is fixed on the recording medium and an image is formed.

  The recording medium supply unit 5 includes an automatic paper feed tray 35, a pickup roller 36, a transport roller 37, a registration roller 38, and a manual paper feed tray 39. The automatic paper feed tray 35 is a container-like member that is provided in the lower part of the image forming apparatus 100 in the vertical direction and stores a recording medium. Examples of the recording medium include plain paper, color copy paper, overhead projector sheet, and postcard. The pick-up roller 36 takes out the recording medium stored in the automatic paper feed tray 35 one by one and feeds it to the paper transport path S1. The conveyance rollers 37 are a pair of roller members provided so as to be in pressure contact with each other, and convey the recording medium toward the registration rollers 38. The registration rollers 38 are a pair of roller members provided so as to be in pressure contact with each other, and the recording medium fed from the conveyance roller 37 is used to convey the toner image carried on the intermediate transfer belt 25 to the transfer nip portion. Synchronously, it is fed to the transfer nip. The manual paper feed tray 39 is a device for taking a recording medium into the image forming apparatus 100 by a manual operation. The recording medium taken from the manual paper feed tray 39 passes through the paper conveyance path S2 by the conveyance roller 37. Then, it is fed to the registration roller 38. According to the recording medium supply means 5, the toner image carried on the intermediate transfer belt 25 is conveyed to the transfer nip portion of the recording medium supplied one by one from the automatic paper feed tray 35 or the manual paper feed tray 39. In synchronism with this, the sheet is fed to the transfer nip portion.

  The discharge unit 6 includes a conveyance roller 37, a discharge roller 40, and a discharge tray 41. The conveyance roller 37 is provided downstream of the fixing nip portion in the sheet conveyance direction, and conveys the recording medium on which the image is fixed by the fixing unit 4 toward the discharge roller 40. The discharge roller 40 discharges the recording medium on which the image is fixed to a discharge tray 41 provided on the upper surface in the vertical direction of the image forming apparatus 100. The discharge tray 41 stores a recording medium on which an image is fixed.

The image forming apparatus 100 includes a control unit (not shown). For example, the control unit is provided in an upper part of the internal space of the image forming apparatus 100 and includes a storage unit, a calculation unit, and a control unit. The storage unit of the control unit stores various setting values via an operation panel (not shown) arranged on the upper surface of the image forming apparatus 100, detection results from sensors (not shown) arranged at various locations inside the image forming apparatus 100, and external Image information from the device is input. In addition, programs for executing various means are written. Examples of the various means include a recording medium determination unit, an adhesion amount control unit, and a fixing condition control unit. As the storage unit, those commonly used in this field can be used, and examples thereof include a read only memory (ROM), a random access memory (RAM), and a hard disk drive (HDD). As the external device, an electric / electronic device that can form or acquire image information and can be electrically connected to the image forming apparatus 100 can be used. For example, a computer, a digital camera, a television, a video recorder, a DVD recorder HD DVD, Blu-ray disc recorder, facsimile device, portable terminal device and the like. The arithmetic unit takes out various data (image formation command, detection result, image information, etc.) written in the storage unit and programs of various means, and performs various determinations. The control unit sends a control signal to the corresponding device according to the determination result of the calculation unit, and performs operation control. The control unit and the calculation unit include a processing circuit realized by a microcomputer, a microprocessor, or the like provided with a central processing unit (CPU). The control means includes a main power supply together with the processing circuit described above, and the power supply supplies power not only to the control means but also to each device in the image forming apparatus 100.

5. Fixing Device FIG. 6 is a schematic view schematically showing the developing device 14 provided in the image forming apparatus 100 shown in FIG. The developing device 14 includes a developing tank 20 and a toner hopper 21. The developing tank 20 is disposed so as to face the surface of the photosensitive drum 11, and supplies and develops a toner to an electrostatic latent image formed on the surface of the photosensitive drum 11 to form a visible toner image. It is a shaped member. The developing tank 20 accommodates toner in its internal space and accommodates roller members such as the developing roller 50, the supply roller 51, and the stirring roller 52, and rotatably supports them. Moreover, you may accommodate a screw member instead of a roller-shaped member. The developing device 14 of this embodiment stores the toner of the above-described embodiment in the developing tank 20 as toner.

  An opening 53 is formed on a side surface of the developing tank 20 facing the photosensitive drum 11, and a developing roller 50 is rotatably provided at a position facing the photosensitive drum 11 through the opening 53. The developing roller 50 is a roller-like member that supplies toner to the electrostatic latent image on the surface of the photosensitive drum 11 at the pressure contact portion or the closest portion to the photosensitive drum 11. When supplying the toner, a potential having a polarity opposite to the charging potential of the toner is applied to the surface of the developing roller 50 as a developing bias voltage (hereinafter simply referred to as “developing bias”). As a result, the toner on the surface of the developing roller 50 is smoothly supplied to the electrostatic latent image. Further, by changing the developing bias value, the toner amount supplied to the electrostatic latent image, that is, the toner adhesion amount of the electrostatic latent image can be controlled.

  The supply roller 51 is a roller-like member that faces the developing roller 50 and can be driven to rotate, and supplies toner around the developing roller 50.

  The agitation roller 52 is a roller-like member provided so as to be able to be driven to rotate while facing the supply roller 51, and feeds toner newly supplied from the toner hopper 21 into the developing tank 20 to the periphery of the supply roller 51. The toner hopper 21 is provided so that a toner replenishing port 54 provided at the lower part in the vertical direction and a toner receiving port 55 provided at the upper part in the vertical direction of the developing tank 20 communicate with each other. Add toner. Further, the toner may be directly supplied from each color toner cartridge without using the toner hopper 21.

  As described above, since the developing device 14 develops a latent image using the developer of the present invention, a high-definition toner image can be stably formed on the photosensitive drum 11. Therefore, the developing device 14 can stably form a good toner image on the surface of the image carrier over a long period of time.

  Further, according to the present invention, the photosensitive drum 11 on which the latent image is formed, the charging unit 12 and the exposure unit 13 that form the latent image on the photosensitive drum 11, and the high-definition toner image as described above are photosensitive. The image forming apparatus 100 includes the developing device 14 of the present invention that can be formed on the body drum 11. By forming an image with such an image forming apparatus 100, a good image can be stably obtained over a long period of time.

  Hereinafter, the present invention will be specifically described with reference to Examples and Comparative Examples. In the following, “parts” and “%” mean “parts by weight” and “% by weight” unless otherwise specified. The glass transition temperature of the binder resin and toner base particles used in the examples and comparative examples, the softening temperature of the binder resin, the melting point of the release agent, and the volume average particle diameter of the toner base particles were measured as follows. .

[Glass transition temperature of binder resin and toner base particles]
Using a differential scanning calorimeter (trade name: DSC220, manufactured by Seiko Denshi Kogyo Co., Ltd.), according to Japanese Industrial Standard (JIS) K7121-1987, 1 g of a sample (binder resin or toner base particles) was heated at a rate of 10 / min. The DSC curve was measured by heating at ° C. Draw the endothermic peak corresponding to the glass transition of the obtained DSC curve at a point where the slope is maximum with respect to the straight line that extends the base line on the high temperature side to the low temperature side and the curve from the rising part of the peak to the vertex. The temperature at the intersection with the tangent was determined as the glass transition temperature (Tg).

[Softening temperature of binder resin]
In a flow characteristic evaluation apparatus (trade name: Flow Tester CFT-100C, manufactured by Shimadzu Corporation), a load of 20 kgf / cm ² (9.8 × 10 ⁵ Pa) is applied and 1 g of a sample (binder resin) is a die (nozzle). It was set to be extruded from a diameter of 1 mm and a length of 1 mm), heated at a heating rate of 6 ° C. per minute, and the temperature at which half of the sample flowed out of the die was determined as the softening temperature (Tm).

[Melting point of release agent]
Using a differential scanning calorimeter (trade name: DSC220, manufactured by Seiko Denshi Kogyo Co., Ltd.), 1 g of a sample (release agent) was heated from a temperature of 20 ° C. to 200 ° C. at a heating rate of 10 ° C. per minute, and then 200 ° C. The operation of rapidly cooling to 20 ° C. was repeated twice, and the DSC curve was measured. The temperature at the top of the endothermic peak corresponding to the melting of the DSC curve measured in the second operation was determined as the melting point of the release agent.

[Volume average particle diameter of toner base particles, toner and externally added toner]
To 50 ml of electrolyte (trade name: ISOTON-II, manufactured by Beckman Coulter, Inc.), 20 mg of sample (toner mother particles) and 1 ml of sodium alkyl ether sulfate are added, and an ultrasonic disperser (trade name: tabletop type two-frequency ultrasonic) A measurement sample was prepared by performing a dispersion treatment at an ultrasonic frequency of 20 kHz for 3 minutes using a cleaning device VS-D100 (manufactured by ASONE Corporation). This sample for measurement was measured using a particle size distribution measuring device (trade name: Multisizer III, manufactured by Beckman Coulter, Inc.) under the conditions of aperture diameter: 100 μm, number of measured particles: 50000 count, and volume particle size distribution of sample particles. From this, the volume average particle size was determined.

[Volume average particle diameter of resin fine particles]
Measurement was performed using a laser diffraction / scattering particle size distribution measuring apparatus (trade name: Microtrack MT3000, manufactured by Nikkiso Co., Ltd.). In order to prevent agglomeration of the measurement sample (resin fine particles), the dispersion containing the measurement sample (fine particles and non-spherical particles) dispersed in an aqueous solution containing Family Fresh (manufactured by Kao Corporation) is stirred and then injected into the apparatus. And it measured twice and calculated | required the average value. The measurement conditions were a measurement time of 30 seconds, a particle refractive index of 1.4, a particle shape of non-spherical, a solvent of water, and a solvent refractive index of 1.33. The volume particle size distribution of the measurement sample was measured, and from the measurement results, the particle size at which the cumulative volume from the small particle size side in the cumulative volume distribution was 50% was calculated as the volume average particle size (μm) of the particles.

  First, an example and a comparative example for evaluating the increase and the presence or absence of the spray liquid in the spraying process and the spraying time will be described.

Example 1-a
[Toner mother particle production step S1]
The toner base particle raw material and the addition amount thereof are as follows.
Polyester resin (trade name: Diacron, manufactured by Mitsubishi Rayon Co., Ltd., glass transition temperature 55 ° C., softening temperature 130 ° C.) 87.5% (100 parts)
-Colorant (CI Pigment Blue 15: 3) 5.0% (5.7 parts)
Release agent (carnauba wax, melting point 82 ° C.) 6.0% (6.9 parts)
・ Charge control agent (trade name: Bontron E84, Orient Chemical Co., Ltd.)
1.5% (1.7 parts)

  Each of the above components was premixed with a Henschel mixer (trade name: FM20C, manufactured by Mitsui Mining Co., Ltd.) and then melt-kneaded with a twin-screw extrusion kneader (trade name: PCM65, manufactured by Ikekai Co., Ltd.). This melt-kneaded product is roughly pulverized by a cutting mill (trade name: VM-16, manufactured by Orient Co., Ltd.), then finely pulverized by a jet mill (manufactured by Hosokawa Micron Co., Ltd.), and further an air classifier (manufactured by Hosokawa Micron Co., Ltd.). Thus, toner mother particles having a volume average particle diameter of 6.5 μm and a glass transition temperature of 56 ° C. were produced.

[Resin fine particle preparation step S2]
A polymer obtained by polymerizing styrene and butyl acrylate is freeze-dried, and the resin fine particles are styrene-butyl acrylate copolymer fine particles A having a volume average particle size of 0.1 μm (glass transition temperature 72 ° C., softening temperature 126 ° C.). Got.

[Coating step S3]
The toner base produced above by a device (device M) in which a two-fluid nozzle is attached as a spraying means to a hybridization system (trade name: NHS-3 type, manufactured by Nara Machinery Co., Ltd.) according to the device shown in FIG. After stirring and mixing 600 parts by weight of particles and 60 parts by weight of resin fine particles for 10 minutes, ethanol is sprayed to form a film, and then ethanol spraying is stopped and stirred for 5 minutes to obtain the toner of Example 1-a. It was.

  The internal volume of the range in which air circulates inside the apparatus, that is, the volume in the powder flow path is 26.8L. Air was allowed to flow into the powder channel from the rotating shaft and one two-fluid nozzle. One two-fluid nozzle was provided at the same position as the first two-fluid nozzle 205a shown in FIG. In the rotating shaft portion, the pressure was controlled to keep the pressure higher than that in the powder passage, and the air flow rate flowing from the rotating shaft portion into the powder passage was adjusted to 5 L / min.

  The convergence time τ at this time is τ = 2.68 minutes from τ = V / Fair. Ethanol was sprayed from one two-fluid nozzle for 10 minutes (variable spray time T3 was 10 minutes). The spray rate when there was no increase in spray liquid was 0.5 g / min. The gas concentration D∞ when the spraying is started and time has passed sufficiently is D∞ = 2.43 vol% from D∞ = (Fin / Fair). When calculated using these values, the gas flow rate gas quantification κ is 0.65 L from κ = D∞V.

  During the increased spray time T2 = 0.6τ from the start of spraying with the two-fluid nozzle, the amount of ethanol sprayed is increased by an amount corresponding to an increased gas volume k of 1.2κ with respect to the gas quantity κ in the powder flow path. I let you. The increase spray rate Fa of ethanol in an amount corresponding to the increase gas volume k was set to 0.2 κ / τ. A value obtained by combining the increased spray speed Fa and the spray speed when there is no increase in the spray liquid is the spray speed at the increased spray time T2.

  A liquid spraying unit was used as the spraying means. A commercially available product can be used as the liquid spray unit, and the liquid is passed through a liquid feed pump (trade name: SP11-12, manufactured by Flume Corporation), and a two-fluid nozzle (trade name: HM-6, manufactured by Fuso Seiki Co., Ltd. ) Was used so as to deliver a fixed amount of liquid. The liquid spray rate and gas discharge rate were observed using a commercially available gas detector (trade name: XP-3110, manufactured by Shin Cosmos Electric Co., Ltd.).

  The temperature adjusting jacket was provided on the entire surface of the powder flow section and the stirring section wall. A temperature sensor was attached to the powder channel. The temperature of the powder flow part and the stirring part was adjusted to 55 ° C. In the apparatus, the peripheral speed at the outermost periphery of the rotating stirring means of the hybridization system was set to 100 m / sec in the resin fine particle attaching process to the surface of the toner base particles. The peripheral speed was also set to 100 m / sec in the spraying process and the film forming process. The mounting angle of the two-fluid nozzle was set so that the angle formed between the liquid spraying direction and the powder flow direction (hereinafter referred to as “spraying angle”) was parallel (0 °).

(Example 2-a)
A toner of Example 2-a was obtained in the same manner as in Example 1-a, except that an apparatus (apparatus L) equipped with a two-fluid nozzle was used for the hybridization system having different powder flow path internal volumes. The internal volume within the range in which air circulates inside the apparatus, that is, the volume V in the powder flow path is 39.7L. The convergence time τ at this time is 3.97 minutes from τ = V / Fair. The gas concentration D∞ is given as D∞ = 2.43 vol% from D∞ = (Fin / Fair). When calculated using these, the gas quantification κ in the powder passage is κ = 0.97 L from κ = D∞V.

  During the increased spray time T2 = 0.6τ, the amount of ethanol sprayed was increased by an amount corresponding to an increased gas volume k of 1.2κ relative to the gas flow rate gas κ in the powder flow path. The increased spray rate Fa at that time was set to 2κ / τ.

(Comparative Example 1-a)
A toner of Comparative Example 1 was obtained in the same manner as in Example 1 except that the amount of ethanol sprayed was not increased.

(Comparative Example 2-a)
A toner of Comparative Example 2 was obtained in the same manner as Example 2 except that the amount of ethanol spray was not increased.

(Examples 1-b to e, Examples 2-b to e, Comparative Examples 1 to b, and Comparative Examples 2-b to e)
By changing the variable spraying time T3 of the spraying means in Examples 1 and 2 and Comparative Examples 1 and 2 from 10 minutes to 20 minutes, 30 minutes, 45 minutes, and 60 minutes, Examples 1-b to 1-e, The toners of Examples 2-b to 2-e, Comparative Examples 1-b to 1-e, and Comparative Examples 2-b to 2-e were prepared.
Table 1 summarizes the apparatus and variable spray time T3 used in the above examples and comparative examples.

  FIG. 7 shows changes in the gas concentration D in the powder passages in Examples 1-e and 2-e and Comparative Examples 1-e and 2-e in which the variable spray time T3 is 60 minutes. It should be noted that the gas concentration change similar to that shown in FIG.

As shown in FIG. 7, in the example, the gas concentration reaches a constant concentration earlier than the comparative example. In particular, when Example 2 having a large volume in the powder flow path is compared with Comparative Example 2, there is a large difference in the time required to reach a certain concentration.
The following evaluations were performed using the toners obtained in the above Examples and Comparative Examples.

<Rough powder content>
Using the particle size distributions of the toners of Examples and Comparative Examples, the content of large particle size particles, that is, coarse powders, was evaluated. To 50 ml of electrolytic solution (trade name: ISOTON-II, manufactured by Beckman Coulter, Inc.), 20 mg of toner and 1 ml of sodium alkyl ether sulfate are added, and an ultrasonic disperser (trade name: desktop type dual frequency ultrasonic cleaner VS-D100. (Manufactured by As One Co., Ltd.) for 3 minutes at an ultrasonic frequency of 20 kHz to prepare a measurement sample. This sample for measurement was measured using a particle size distribution measuring device (trade name: Multisizer III, manufactured by Beckman Coulter, Inc.) under the conditions of aperture diameter: 100 μm, number of measured particles: 50000 count, and from the volume particle size distribution of the toner. The ratio of the coarse powder having a particle diameter of 12 μm or more was determined, and this was defined as the coarse powder content. It can be said that the smaller the ratio is, the more desirable the toner is.

The evaluation criteria for the coarse powder content are as follows.
A: No coarse powder. The coarse powder content is less than 1%.
○: Trace amount of coarse powder. The coarse powder content is 1% or more and less than 3%.
Δ: A small amount of coarse powder. The coarse powder content is 3% or more and less than 10%.
X: A large amount of coarse powder. The coarse powder content is 10% or more.

<Coating uniformity>
The coating uniformity was evaluated by the presence or absence of toner aggregates after high temperature storage. After 20 g of toner was sealed in a plastic container and allowed to stand at 50 ° C. for 48 hours, the toner was taken out and passed through a 230 mesh sieve. The weight of the toner remaining on the sieve was measured, and the remaining amount, which is the ratio of this weight to the total toner weight, was determined and evaluated according to the following criteria. A lower numerical value indicates that the toner does not block and the storage stability is better.

The evaluation criteria for coating uniformity are as follows.
A: No aggregation. The remaining amount is less than 1%.
○: Aggregation trace amount. The remaining amount is 1% or more and less than 3%.
Δ: Small amount of aggregation. The remaining amount is 3% or more and less than 20%.
X: Large amount of aggregation. The remaining amount is 20% or more.
Table 2 shows the evaluation results of the coarse powder content and the coating uniformity.

  In the evaluation of the coarse content rate, there is a tendency that the coarse particles increase as the variable spray time T3 is increased. In the evaluation of the coating uniformity, there is a tendency that the coating uniformity improves as the variable spraying time T3 is increased, but in the examples, suitable coating uniformity was shown even when the spraying time was short.

<Comprehensive evaluation of toner for variable spraying time T3>
Based on the said coarse powder content rate and evaluation of coating | coated uniformity, comprehensive evaluation of the Example and the comparative example was performed. First, in ◎, ○, Δ, and ×, which are evaluation results of the coarse powder content and coating uniformity, ◎ was converted into a score, 3 points, ○ was 2 points, Δ was 1 point, and x was 0 point. Next, the scores of Examples 1-a to 1-e were added to obtain a comprehensive evaluation score of Example 1. Similarly, comprehensive evaluation scores of Example 2 and Comparative Examples 1 and 2 were obtained. Comprehensive evaluation was performed using these comprehensive evaluation scores and the following comprehensive evaluation criteria.

The overall evaluation results are as follows.
A: Very good. The overall evaluation score exceeds 25 points.
○: Good. The comprehensive evaluation score exceeds 20 points and is 25 points or less.
Δ: Slightly poor The overall evaluation score exceeds 15 points and is 20 points or less.
X: Defect. The overall evaluation score is 10 points or less.
The evaluation results are shown in Table 3.

  From the results shown in Table 3, it is possible to produce a toner with good performance regardless of the length of spraying time if it is manufactured by the toner manufacturing method of the present invention. It can be seen that the toner can be manufactured.

  Next, examples and comparative examples for evaluating the relationship between the increased gas volume k of the spray liquid and the increased spray time T2 will be described.

(Examples 3 to 6)
Toners of Examples 3 to 6 were obtained in the same manner as in Example 2-c except that the increased gas volume k and the increased spray time T2 were adjusted to the values shown in Table 4.

(Comparative Examples 3-6)
Toners of Comparative Examples 3 to 6 were obtained in the same manner as in Example 2-c except that the increased gas volume k and the increased spray time T2 were adjusted to the values shown in Table 4.

  Table 4 shows the relationship between the increased gas volume k and the increased spray time T2 in Example 2-c, Examples 3-6, and Comparative Examples 3-6.

  Using the toners of Examples 3 to 6 and Comparative Examples 3 to 6, the coarse powder content and the coating uniformity were evaluated. The evaluation method of the coarse powder content and the coating uniformity is the same as the evaluation method of the coarse powder content and the coating uniformity of Examples 1 and 2 and Comparative Examples 1 and 2.

[Comprehensive evaluation of toner with respect to relationship between increased gas volume k and increased spray time T2]
Based on the evaluation results of coarse particles and coating uniformity, the toners of Examples 3 to 6 and Comparative Examples 3 to 6 were comprehensively evaluated.

  As the standard for comprehensive evaluation, the worst standard among coarse particles or coating uniformity was used as an index for comprehensive evaluation.

  From the results shown in Table 5, it is necessary to increase the spray amount while the increased gas volume k is 0.6κ to 1.6κ and the increased spray time T2 is 0.2τ to 1.0τ. I understand. Within this range, it was confirmed that a toner having few coarse particles and excellent coating uniformity can be produced stably.

(Example 7)
In the coating step S3, an example is used except that two spraying means of the first spraying means and the second spraying means are used as the spraying means, and air is allowed to flow into the powder channel from the rotating shaft portion and the two two-fluid nozzles. In the same manner as in Example 5, a toner of Example 7 was obtained. The first two-fluid nozzle that is the first spraying means is provided at the position of the first two-fluid nozzle 205a shown in FIG. 3, and the second two-fluid nozzle that is the second spraying means is the position of the second two-fluid nozzle 205b shown in FIG. Provided in position. From the first two-fluid nozzle, the spray liquid was sprayed in a constant amount for 30 minutes over the entire spray process S3 (the fixed spray time T4 was set to 30 minutes). As the second two-fluid nozzle, a two-fluid nozzle having the same configuration as that of the first two-fluid nozzle is used. An amount of ethanol that was an additional gas volume K of 1.6 kappa was sprayed only during this period.

  In the rotating shaft part, the pressure was controlled to keep the rotating shaft part at a higher pressure than in the powder flow path, and the air flow rate flowing from the rotating shaft part into the powder flow path was adjusted to 5 L / min. The carrier gas flow rate of the first two-fluid nozzle was adjusted to 2.5 L / min. Similarly, the second two-fluid nozzle was adjusted to 2.5 L / min. The air flow rate from the two two-fluid nozzles and the air flow rate from the rotating shaft were added together, and 10 L per minute was discharged out of the apparatus as discharged air.

表６から、２つの噴霧手段を利用することによって粗粉含有率が改善されたことが示された。 For the toner obtained in Example 7, the coarse powder content and coating uniformity were evaluated in the same manner as in the above Examples and Comparative Examples. The evaluation results are shown in Table 6.

Table 6 shows that the coarse powder content was improved by using two spraying means.

Next, examples for evaluating the physical properties of the spray liquid will be described.
(Example 8)
A toner of Example 8 was obtained in the same manner as in Example 1-c except that methanol was used instead of ethanol as the spray liquid. The LEL concentration of methanol is 6.7 vol%.

Example 9
A toner of Example 9 was obtained in the same manner as in Example 1-c except that propanol was used instead of ethanol as the spray liquid. The LEL concentration of propanol is 2.0 vol%.

(Example 10)
A toner of Example 10 was obtained in the same manner as in Example 1-c except that 2-butanol was used instead of ethanol as the spray liquid. The LEL concentration of 2-butanol is 1.7 vol%.

(Example 11)
A toner of Example 11 was obtained in the same manner as in Example 1-c except that 1-butanol was used instead of ethanol as the spray liquid. The LEL concentration of 1-butanol is 1.4 vol%.

  For the toners of Examples 8 to 11, the coarse powder content and the coating uniformity were evaluated. The evaluation method of the coarse powder content rate and the coating uniformity is the same as the evaluation method of the coarse powder content rate and the coating uniformity of the above-described Examples and Comparative Examples. Table 7 shows the evaluation results.

  The LEL concentration coefficient X described in Table 7 is: X = {(gasification volume of spray liquid sprayed per unit time) / (powder channel volume V)} × 100 / (LEL concentration of spray liquid) ).

  From the results in Table 7, it can be seen that a suitable toner can be produced particularly when the LEL concentration is 1.7 vol% or more and 6.7 vol% or less. Furthermore, the use of methanol, ethanol, or propanol, which are tertiary alcohols lower than tertiary, suppresses the generation of coarse particles, and a more suitable toner can be produced.

  Magenta, cyan, and yellow color toners were respectively produced by the manufacturing methods of the above-described examples and comparative examples. The color developer containing each of these was used to evaluate the cleaning property, charging stability and density uniformity.

Example 12
[Production of magenta toner]
A magenta toner was prepared in the same manner as in Example 2-c except that the composition of the toner base particles was changed to the following composition in the toner base particle preparation step S1.

The toner base particle raw material and the addition amount thereof were as follows.
Polyester resin (trade name: Diacron, manufactured by Mitsubishi Rayon Co., Ltd., glass transition temperature 55 ° C., softening temperature 130 ° C.) 87.5% (100 parts)
-Magenta pigment: C.I. I. Pigment Red 122 [Toner Magenta E-02 (manufactured by Clariant Japan)] 5.0% (5.7 parts)
Release agent (carnauba wax, melting point 82 ° C.) 6.0% (6.9 parts)
・ Charge control agent (trade name: Bontron E84, Orient Chemical Co., Ltd.)
1.5% (1.7 parts)

[Production of cyan toner]
A cyan toner was prepared in the same manner as in Example 2-c except that the composition of the toner base particles was changed to the following composition in the toner base particle preparation step S1.

The toner base particle raw material and the addition amount thereof were as follows.
Polyester resin (trade name: Diacron, manufactured by Mitsubishi Rayon Co., Ltd., glass transition temperature 55 ° C., softening temperature 130 ° C.) 87.5% (100 parts)
-Cyan pigment: C.I. I. Pigment Blue 15: 3 [Hosteaperm Blue B2G (manufactured by Clariant Japan)] 5.0% (5.7 parts)
Release agent (carnauba wax, melting point 82 ° C.) 6.0% (6.9 parts)
・ Charge control agent (trade name: Bontron E84, Orient Chemical Co., Ltd.)
1.5% (1.7 parts)

[Production of yellow toner]
A yellow toner was prepared in the same manner as in Example 2-c except that the composition of the toner base particles was changed to the following composition in the toner base particle preparation step S1.

The toner base particle raw material and the addition amount thereof were as follows.
Polyester resin (trade name: Diacron, manufactured by Mitsubishi Rayon Co., Ltd., glass transition temperature 55 ° C., softening temperature 130 ° C.) 87.5% (100 parts)
-Yellow pigment: C.I. I. Pigment Yellow 74 [FAST YELLOW FGOK (Sanyo Color Co., Ltd.)] 5.0% (5.7 parts)
Release agent (carnauba wax, melting point 82 ° C.) 6.0% (6.9 parts)
・ Charge control agent (trade name: Bontron E84, Orient Chemical Co., Ltd.)
1.5% (1.7 parts)

  The three color toners are collectively referred to as toner of Example 12. In the following evaluation of the cleaning property, charging stability and density uniformity, the above three color toners were used, and these were collectively evaluated as the toner of Example 12.

(Example 13)
Magenta toner, cyan toner and yellow toner were prepared in the same manner as in Example 12 except that the method of Example 3 was used instead of the method of Example 2-c. did.

(Example 14)
A magenta toner, a cyan toner and a yellow toner were prepared in the same manner as in Example 12 except that the method of Example 4 was used instead of the method of Example 2-c. did.

(Example 15)
A magenta toner, a cyan toner, and a yellow toner were prepared in the same manner as in Example 12 except that the method of Example 5 was used instead of the method of Example 2-c. did.

(Example 16)
Magenta toner, cyan toner and yellow toner were prepared in the same manner as in Example 12 except that the method of Example 6 was used instead of the method of Example 2-c. did.

(Example 17)
Magenta toner, cyan toner and yellow toner were prepared in the same manner as in Example 12 except that the method of Example 7 was used instead of the method of Example 2-c. did.

(Comparative Example 7)
A magenta toner, a cyan toner and a yellow toner were produced in the same manner as in Example 12 except that the method of Comparative Example 2 was used instead of the method of Example 2-c. did.

(Comparative Example 8)
The three-color color toner base particles produced in Example 12 were used as they were as the three-color toner. These toners were collectively used as the toner of Comparative Example 8.

The following operations were performed on these color toners to obtain external color toners.
In 100 parts of the color toner, 1.3 parts of hydrophobic silica fine particles having an average primary particle diameter of 12 nm as surface modifying agents and 0.5 parts of hydrophobic silica fine particles having an average primary particle diameter of 200 nm. And 0.6 part by weight of hydrophobic titanium oxide having an average primary particle size of 30 nm, and using a Henschel mixer (trade name: FM20C, manufactured by Mitsui Mining Co., Ltd.), the peripheral speed of the rotating member is set to 35 m. / S was mixed for 3 minutes to obtain an external color toner.

  The externally added color toners of Examples and Comparative Examples thus obtained and the silicone-coated ferrite core carrier having a volume average particle diameter of 60 microns are adjusted and mixed so that the toner concentration becomes 5%. Thus, two-component developers of Examples and Comparative Examples were prepared.

[Cleanability]
Each of the two-component developers of Examples and Comparative Examples is put into a copier (trade name: MX-2300G, manufactured by Sharp Corporation) having a commercially available two-component developing device, and 1000 charts with a printing rate of 5% are continuously provided. After printing, it was visually confirmed whether filming had occurred on the surface of the photoreceptor.

The evaluation criteria for the cleaning property are as follows.
○: Good. The occurrence of filming is not confirmed for all colors.
Δ: Slightly poor The occurrence of filming is confirmed for only one color.
X: Defect. The occurrence of filming is confirmed for two or more colors.

[Charging stability]
The charging stability was measured by measuring the charge amount of the two-component developer after printing the chart. The charge amount was compared for each color, and evaluation was made based on a charge amount difference ΔQc (μC / g) which is a difference between the minimum toner charge amount and the maximum toner charge amount. Thus, a characteristic difference due to a difference in color of toner base particles coated with resin fine particles under the same coating conditions was confirmed.

The evaluation criteria for charging stability are as follows.
○: Good. The charge amount difference is 5 μC / g or less.
Δ: No problem in actual use. The charge amount difference exceeds 5 μC / g and is 7 μC / g or less.
X: Defect. The charge amount difference exceeds 7 μC / g.

[Density uniformity]
Density uniformity was evaluated by measuring density unevenness at the time of printing 10,000 sheets in the copying machine. The density unevenness was measured by the following method.

  Five patches are printed at regular intervals in the circumferential direction, their image density ID is measured using X-Rite, and the density is the difference between the maximum density and the minimum density in patches of the same color. The density uniformity was evaluated by determining the difference ΔID. The density difference ΔID used for the evaluation was the largest among the three colors.

The evaluation standard of density uniformity is as follows.
○: Good. The density difference is 0.2 or less.
Δ: No problem in actual use. The density difference is more than 0.2 and 0.3 or less.
X: Defect. The density difference exceeds 0.3.

[Comprehensive evaluation of two-component developer]
A comprehensive evaluation was performed based on the evaluation results of the cleaning property, charging stability, and concentration uniformity.

The overall evaluation criteria are as follows.
○: Good. The evaluation results of cleaning property, charging stability and density uniformity are all “◯”.
Δ: Slightly poor There are no crosses in the evaluation results of cleaning property, charging stability and density uniformity, and there is one or more Δ.
X: Defect. X is present in the evaluation results of cleaning property, charging stability and density uniformity.
The results are shown in Table 8.

  From the above results, it can be seen that by performing the encapsulation according to the present invention, the characteristics as a developer are improved, and in particular, the difference of the toner base material due to the color material can be eliminated. In addition, by comparing the comparative example 2 and the example, the present invention improves the cleaning property by reducing the adverse effect on the cleaning property due to the finely formed fine particles, and also improves the density uniformity because the coarse particles are reduced. I was able to confirm.

6 is a flowchart illustrating an example of a procedure of a toner manufacturing method according to the exemplary embodiment. 1 is a front view illustrating a configuration of a toner manufacturing apparatus 201 used in a toner manufacturing method according to a first embodiment of the present invention. FIG. FIG. 3 is a schematic cross-sectional view of the toner manufacturing apparatus 201 shown in FIG. 2 as viewed from a cutting plane line A200-A200. FIG. 3 is a front view showing a configuration around a powder charging unit 206 and a powder recovery unit 207. It is sectional drawing which shows typically the structure of the image forming apparatus 100 which is the 4th Embodiment of this invention. FIG. 6 is a schematic view schematically showing a developing device 14 provided in the image forming apparatus 100 shown in FIG. 5. It is a graph which shows the change of the gas density | concentration D in the powder flow path in Example 1-e, 2-e and Comparative example 1-e, 2-e.

Explanation of symbols

DESCRIPTION OF SYMBOLS 201 Toner manufacturing apparatus 202 Powder flow path 203 Spraying means 204 Rotating stirring means 206 Powder input part 207 Powder recovery part 220 Stirring blade

Claims (10)

A toner base particle and a resin fine particle are put into a powder flow path in which a rotary stirring means including a rotary disk and a rotary shaft rotating around a rotating blade is rotated, and the toner base particle is flowed in the powder flow path. A resin fine particle attaching step for attaching resin fine particles to the surface;
Using the first spraying means and the second spraying means, spraying the toner mother particles and the resin fine particles that are in a fluid state into the powder flow path with the carrier gas while spraying the spray liquid having an effect of plasticizing those particles, A spraying step of discharging the air containing the atomized liquid and carrier gas gasified in the powder channel out of the powder channel;
A film-forming step in which the rotation of the rotary stirring means is continued until the resin fine particles attached to the surface of the toner base particles form a film, and the toner base particles and the resin fine particles are repeatedly circulated in the powder flow path.
In the spraying process, in addition to the spraying of the spray liquid by the first spraying means, the additional gas satisfying the following expression (2) from the second spraying means until the additional spraying time T1 satisfying the following expression (1) from the start of the spraying. A method for producing toner, characterized in that an amount of spray liquid of a volume amount K is additionally sprayed into the powder flow path.
0.2τ ≦ T1 ≦ τ (τ = V / Fair) (1)
0.6κ ≦ K ≦ 1.6κ (κ = (Fin / Fair) × V) (2)
(Fin indicates the gas volume flow rate obtained by multiplying the spray rate of the spray liquid sprayed from the first spray means into the powder flow path by the volume when the spray liquid is gasified. (The air volume flow rate of the air discharged from the powder flow path is shown, and V indicates the volume in the powder flow path.) A toner base particle and a resin fine particle are put into a powder flow path in which a rotary stirring means including a rotary disk and a rotary shaft rotating around a rotating blade is rotated, and the toner base particle is flowed in the powder flow path. A resin fine particle attaching step for attaching resin fine particles to the surface;
The spraying means is used to spray toner liquid and toner fine particles that are in a fluidized state into the powder channel by spraying a spray liquid that has the effect of plasticizing those particles into the powder channel. Spraying step of discharging the air containing the atomized liquid and carrier gas out of the powder flow path;
A film-forming step in which the rotation of the rotary stirring means is continued until the resin fine particles attached to the surface of the toner base particles form a film, and the toner base particles and the resin fine particles are repeatedly circulated in the powder flow path.
In the spraying step, the amount of spray from the spraying means is increased by an amount corresponding to the increased gas volume k satisfying the following formula (4) from the start of spraying by the spraying means to the increasing spray time T2 satisfying the following formula (3). And a method for producing the toner.
0.2τ ≦ T2 ≦ τ (τ = V / Fair) (3)
0.6κ ≦ k ≦ 1.6κ (κ = (Fin / Fair) × V) (4)
(Fin indicates the gas volume flow rate obtained by multiplying the spray rate when the spray liquid is sprayed into the powder flow path without increasing by the volume amount when the spray liquid is gasified. (The air volume flow rate of the air discharged from the body channel is shown, and V shows the volume in the powder channel.)   The method for producing a toner according to claim 1 or 2, wherein the film forming step has a time of 10 minutes to 45 minutes.   The method for producing a toner according to any one of claims 1 to 3, wherein the spray liquid is an alcohol having an LEL concentration of 1.7 vol% to 6.7 vol% when gasified. .   The method for producing a toner according to claim 1, wherein the spray liquid is a lower alcohol having 3 or less carbon atoms in the molecule.   A toner manufactured by the method for manufacturing a toner according to claim 1.   A developer comprising the toner according to claim 6.   The developer according to claim 7, wherein the developer is a two-component developer including the toner and a carrier.   A developing device that develops a latent image formed on an image carrier using the developer according to claim 7 to form a toner image. An image carrier on which a latent image is formed;
A latent image forming means for forming a latent image on the image carrier;
An image forming apparatus comprising: the developing device according to claim 9.

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