JP5377060B2 - Toner production method, toner and two-component developer - Google Patents

Description

  The present invention relates to a toner production method, a toner, and a two-component developer.

  Toner that visualizes a latent image is used in various image forming processes, and as an example, it is known to be used in an electrophotographic image forming process.

  Image formation in an electrophotographic image forming apparatus is performed according to each process of charging, exposure, development, transfer, and fixing. First, in the charging step, the surface of the photoreceptor, which is an image carrier for forming an electrostatic latent image, is uniformly charged. In the exposure step, an electrostatic latent image is formed on the surface of the photosensitive member by irradiating the charged surface of the photosensitive member with light according to image information. In the development step, toner is selectively attached to the formed electrostatic latent image, and a visible image (toner image) is formed on the surface of the photoreceptor. In the transfer step, the toner image is transferred onto the transfer paper by an electric force. In the final fixing step, the toner image transferred onto the transfer paper is melted by heat to fix the toner image on the transfer paper.

  In addition, the colorization technique in the electrophotographic system has been rapidly developed, and full-color image forming apparatuses have been developed and provided to the market. The market for full-color image forming apparatuses is expanding with the spread of black-and-white image forming apparatuses.

  Generally, for color reproduction in a full color image forming apparatus, three subtractive primary colors, cyan (C), magenta (M), yellow (Y), or black (K) is added to these three colors. Four color toners are used. As a color reproduction procedure, for each color of C, M, Y, and K, first, the steps from charging, exposure, development, and transfer in the image forming process are repeated, and a plurality of color toners are formed on the transfer paper. A full color image is formed by overlapping toner images. In the final fixing step, the superimposed toner images are melted and fixed on the transfer paper. In this procedure, the fused toner images are mixed and the color is reproduced according to the principle of subtractive color mixing.

  In such a full-color electrophotographic method, development is performed a plurality of times, and toner images of different colors are superimposed on the same support as the fixing process, so the charging characteristics, flow characteristics, and fixing characteristics that each color toner should have are extremely important. Element.

  In order to maintain good and stable color reproducibility of a full-color image, it is necessary to first deposit a predetermined amount of toner on the surface of the photoreceptor in the development process and transfer it all onto the transfer paper in the transfer process. The charging characteristics of the toner, such as the charge rising characteristics, the environmental stability of the charge amount, and the stability over time, greatly affect the toner adhesion amount in the development and transfer processes. For this reason, the toner contains a charge control agent in addition to the binder resin and the colorant in order to improve and adjust the charge amount.

  In order to improve the charging characteristics of the toner, it is important to uniformly and finely disperse the charge control agent in the toner particles or on the toner particle surfaces.

  For example, Patent Document 1 discloses a method of adjusting both the charge exchange property and the chargeability by adjusting the dispersion diameter of the charge control agent particles dispersed in the toner. Patent Document 2 discloses that a toner having a stable charge amount is provided by coating the surface of a toner base containing no charge control agent with chargeable particles. Patent Document 3 discloses charge control. Disclosed is a method for obtaining a toner having excellent chargeability by embedding a charge control agent in the form of primary particles on the surface of the toner precursor particles produced by kneading, pulverization, and classification from toner compounding components other than the agent. ing.

JP-A-2-161469 JP-A 64-72168 JP-A-2-308262

  However, in the toner containing the charge control agent in the toner particles, the charge control agent is not aggregated in a part of the toner particles or is not uniformly dispersed, and is present as coarse particles at an initial stage. A sufficient charge amount cannot be obtained. In particular, when a high density image is continuously printed, there is a problem that toner rising occurs because of a poor charge rising characteristic.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a toner production method, toner, and two-component developer excellent in charge rising characteristics and charge amount stability over time.

The present invention includes a rotary stirring means including a rotating disk around which a stirring blade is provided and a rotary shaft, and a powder flow path including a rotary stirring chamber and a circulation pipe. Circulating means for repeatedly circulating toner base particles and resin fine particles in the inside,
A temperature adjusting means provided in at least a part of the powder flow path for adjusting the powder flow path and the rotary stirring means to a predetermined temperature;
Resin layer using a rotary stirrer comprising at least spraying means including a two-fluid nozzle comprising a liquid tube for spraying a liquid for assisting adhesion between toner mother particles and resin fine particles and an air tube for spraying a carrier gas In the method for producing a coated toner,
While the toner base particles and the resin fine particles are stirred and circulated in the temperature-adjusted powder flow path, a liquid that does not dissolve the toner base particles and the resin fine particles but is plasticized is used as the liquid. layer coated toner 100 parts by weight 3 parts by weight to by the Hare dissolve and become less than 0.1 parts by weight relative to the spray at a constant speed in the powder passage in the two-fluid nozzle, the toner base particle surfaces a method for producing a dendritic fat layer coated toner you, characterized in that to form a resin layer containing a resin particulate charge control agent.

  The present invention also provides a method for producing a resin layer-coated toner, wherein the charge control agent is contained inside the resin layer of the resin layer-coated toner.

  In the resin layer-coated toner according to the present invention, the charge control agent may include at least one of a metal complex and a metal salt of a salicylic acid derivative and a metal complex and a metal salt of a bisdiphenylglycolic acid derivative. It is a manufacturing method.

  The present invention is also the method for producing a resin layer-coated toner, wherein the liquid for assisting adhesion between the toner base particles and the resin fine particles contains at least a polar solvent.

  The present invention also provides a resin layer-coated toner manufactured by the above-described toner manufacturing method.

  The present invention also provides a two-component developer comprising the resin layer-coated toner and a carrier.

  According to the present invention, the charge control agent that adjusts the charging characteristics of the toner is sprayed from the two-fluid nozzle in a state of being dissolved in a liquid such as a polar solvent. As a result, the charge control agent can be uniformly adhered to the surface of the toner base particles, and a film can be formed together with the resin fine particles. By this method, a toner having a uniform dispersion state of the charge control agent on the surface layer can be produced continuously and stably. In such a toner, since the charge control agent is contained in the coating layer, it is difficult to separate from the toner base particles. Since the coating layer is durable, it prevents the charge control agent from detaching due to long-term use of the toner and prevents changes in the properties of the toner, thus improving the toner charge rise, environmental stability, and stability over time during printing. To do.

  Further, according to the present invention, unlike the case where the charge control agent is mixed in the entire toner base particles, the production method can adjust the concentration of the charge control agent in the toner surface layer. As a result, the rise of charge, environmental stability, and stability over time during printing durability are improved.

  Further, according to the present invention, the charge control agent is easily dissolved in a liquid such as a polar solvent, so that it can be uniformly dispersed in the toner surface layer. Further, since the transparency is high, a clearer image can be obtained.

  Further, according to the present invention, when the liquid for assisting adhesion between the toner base particles and the resin fine particles contains at least a polar solvent, the viscosity of the liquid is lowered, and when the charge control agent is dissolved, the liquid is sprayed. The liquid can be sprayed finely and uniformly without coarsening the droplet diameter. Further, when the droplet collides with the toner base particles and the resin fine particles, miniaturization of the droplet diameter is further promoted. As a result, a resin layer-coated toner in which the charge control agent is uniformly dispersed can be obtained. In addition, polar solvents such as lower alcohols have a high vapor pressure and are therefore easily removed by drying. Therefore, the yield of the resin layer-coated toner having a uniform film state and particle size distribution can be further improved.

  Further, according to the present invention, the concentration of the charge control agent is uniform, and the toner characteristics such as the charging characteristics between the individual toner particles are uniform. The toner of the present invention is excellent in durability because the encapsulated component is protected by a coating layer containing a charge control agent. By using such a toner, it is possible to stably form a high-definition and good-quality image without density unevenness.

  According to the invention, there is provided a two-component developer comprising the resin layer-coated toner of the invention and a carrier. Since the toner of the present invention has uniform toner characteristics such as charging characteristics between individual toner particles, the charging characteristics can be stably maintained. In addition, it is possible to stably form a high-definition and good-quality image without density unevenness.

6 is a flowchart illustrating an example of a procedure of a toner manufacturing method according to the exemplary embodiment. FIG. 3 is a front view showing a configuration of a toner manufacturing apparatus 201 used in the toner manufacturing method 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 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.

1. Toner Manufacturing Method FIG. 1 is a flowchart illustrating an example of a procedure of a toner manufacturing method according to an embodiment of the present invention. The toner production method of the present invention includes a toner base particle preparation step S1, a resin fine particle preparation step S2, a charge control agent-containing liquid preparation step S3, and a coating step S4 for coating the toner base particles with the charge control agent and resin fine particles. Including.

  The toner manufacturing method according to the embodiment of the present invention uses a rotary stirring device. The rotary stirring device includes at least a circulation unit, a temperature adjustment unit, and a spraying unit. The circulation means is composed of a rotating disk having a rotary blade and a rotating stirring means including a rotating shaft, and a powder flow path including a rotating stirring chamber and a circulation pipe. To circulate in the powder flow path. The temperature adjusting means is provided in at least a part of the powder flow path, and adjusts the temperature in the powder flow path and the rotary stirring means to a predetermined temperature. The spraying means comprises a two-fluid nozzle and sprays liquid and gas. The two-fluid nozzle includes a liquid pipe and an air pipe. The liquid pipe is inserted into the air pipe so that the axes of the two pipes coincide with each other, and at least a part of the pipes is fixed so that the center does not deviate. Yes.

  While adjusting the temperature and circulating the toner base particles and resin fine particles in the powder flow path of such a rotary agitator, the two-fluid nozzle assists the adhesion of the toner base particles and resin fine particles and dissolves the charge control agent. The liquid used for this is sprayed at a constant speed to form a resin film in which the charge control agent is mixed on the surface of the toner base particles.

(1) Toner mother particle production step S1
In the toner base particle preparation step S1, toner base particles to be covered with the charge control agent-containing resin layer are prepared. The toner base particles are particles containing a binder resin and a colorant, and the production method thereof is not particularly limited and can be performed by a known method. Examples of the method for producing the toner mother particles include dry methods such as a pulverization method, 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 base particles by a pulverization method will be described.

(Method for preparing 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 solidified product is pulverized by a pulverizer. Thereafter, particle size adjustment such as classification is performed as necessary to obtain toner mother particles.

  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.), Mechano Mill (trade name, manufactured by Okada Seiko Co., Ltd.), etc. Henschel type mixing device, ong mill (trade name, manufactured by Hosokawa Micron Corporation), hybridization system (trade name, manufactured by Nara Machinery Co., Ltd.), Cosmo system (trade name, manufactured by Kawasaki Heavy Industries, Ltd.), and the like.

  A well-known thing can be used also as a kneading machine, For example, common kneading machines, such as a twin-screw extruder, a 3 roll, a laboratory blast mill, are mentioned. More specifically, for example, TEM-100B (trade name, manufactured by Toshiba Machine Co., Ltd.), PCM-65 / 87, PCM-30 (all of which are trade names, manufactured by Ikegai Co., Ltd.), etc. Extruder, Needex (trade name, manufactured by Mitsui Mining Co., Ltd.) and other open roll type kneaders. Among these, an open roll type kneader is preferable.

  As the pulverizer, for example, a jet type pulverizer that pulverizes using a supersonic jet stream, and a solidified material in a space formed between a rotor (rotor) and a stator (liner) that rotate at high speed. An impact pulverizer that introduces and pulverizes can be used.

  For the classification, a known classifier capable of removing the excessively pulverized toner base particles by classification using centrifugal force and 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, polystyrene, styrene resin such as styrene-acrylate copolymer resin, polymethyl Examples thereof include acrylic resins such as methacrylate, polyolefin resins such as polyethylene, polyester, polyurethane, and epoxy resin. Further, a resin obtained by mixing a release agent with the raw material monomer mixture and polymerization reaction may be used. Binder resin can be used individually by 1 type, or can use 2 or more types together.

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

  As the polybasic acid, those known as polyester monomers 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 a polybasic acid and a polyhydric alcohol can be carried out according to a conventional method. For example, a polybasic acid is reacted with a polyhydric alcohol using a polycondensation catalyst in the presence or absence of an organic solvent, and the reaction is performed when the acid value, softening temperature, etc. of the resulting polyester reach a predetermined value. Finish and get polyester.

  When a methyl esterified product of a polybasic acid is used as a part of the polybasic acid, a demethanol polycondensation reaction occurs. In this polycondensation reaction, for example, the carboxyl group content at the end of the polyester can be adjusted by appropriately changing the blending ratio of the polybasic acid and the polyhydric alcohol, the reaction rate, etc., and as a result, a modified polyester is obtained. A modified polyester can also be obtained by using trimellitic anhydride as a polybasic acid and introducing a carboxyl group into the main chain of the polyester. Alternatively, a self-dispersible polyester having self-dispersibility in water can be obtained by bonding a hydrophilic group such as a carboxyl group or a sulfonic acid group to at least one of the main chain or side chain of the polyester. Further, polyester and acrylic resin may be grafted.

  The glass transition point of the binder resin is preferably 30 ° C. or higher and 80 ° C. or lower. If the glass transition point of the binder resin is less than 30 ° C., thermal aggregation (blocking) of the toner tends to occur inside the image forming apparatus, which may reduce storage stability. 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, risol 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. In the case of the same color, two or more kinds can be used in combination. The amount of the colorant to be 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, a polar solvent or the like to two or more kinds of colorants, granulating with a general granulator such as a high speed mill, and drying. The masterbatch and 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, charge control agents for positive charge control and negative charge control which are commonly used in this field can be used.

  Examples of the charge control agent for positive charge control 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 can be mentioned.

  Charge control agents for controlling negative charge include oil-soluble dyes such as oil black and spiron black, metal-containing azo compounds, azo complex dyes, naphthenic acid metal salts, metal complexes and metal salts of salicylic acid and its derivatives (metal is Chromium, zinc, zirconium, etc.), boron compounds, fatty acid soaps, long-chain alkyl carboxylates, resin acid soaps, and the like. The charge control agent can be used alone or in combination of two or more as required. The amount of the charge control agent used is not particularly limited and can be appropriately selected from a wide range, but is preferably 0.1 parts by weight or more and 3 parts by weight or less with respect to 100 parts by weight of the binder resin.

  Further, the toner base particles may contain a release agent. 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, silicon-based 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 with respect to 100 parts by weight of the binder resin. Particularly preferred is 1.0 to 8.0 parts by weight.

  The toner base particles obtained in 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 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 within this range, a high image density can be obtained even if the amount of adhesion is small, and an effect of reducing the toner consumption can be obtained. If the volume average particle size of the toner base particles is less than 4 μm, the particle size is small, and there is a risk of high charging and low fluidization. If the toner is highly charged and fluidized, the toner cannot be stably supplied to the photoconductor, which may cause background fogging and a decrease in image density. When the volume average particle size of the toner base particles exceeds 8 μm, the layer size of the formed image is increased due to the large particle size, resulting in an image with remarkable graininess, and a high-definition image cannot be obtained. Further, as the particle size of the toner base particles increases, the specific surface area decreases and the charge amount of the toner 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 S2, dry resin fine particles are prepared. Any method may be used for drying. For example, dry resin fine particles can be obtained by a method such as hot air heat receiving drying, conductive heat transfer drying, far infrared drying, microwave drying, or the like. The resin fine particles are used as a material for forming a film on the surface of the toner base particles in the subsequent coating step S4.

  By using the resin fine particles as a film forming material on the surface of the toner base particles, for example, it is possible to prevent a low melting point component such as a release agent contained in the toner base particles from aggregating during storage of the toner. In addition, it is possible to adjust the film state when coating the toner base particles and leave the shape of the toner base particles, or to form a film while leaving the uneven shape of the resin fine particles on the surface of the toner base particles. As compared with the toner, a toner having excellent cleaning properties can be obtained.

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

  As the resin fine particle raw material, for example, a resin used for a toner material can be used, and examples thereof include polyester, acrylic resin, styrene resin, and styrene-acrylic copolymer. Among the above resins, it is preferable to include an acrylic resin and a styrene-acrylic copolymer. Acrylic resins and styrene-acrylic copolymers have many advantages such as light weight and high strength, high transparency, low cost, and easy to obtain materials with uniform particle diameters.

  The resin fine particle raw material may be the same type of resin as the binder resin contained in the toner base particles, or may be a different type of resin. It is preferable to use this resin. When different types of resins are used as the resin fine particle raw material, it is preferable that the glass transition temperature of the resin of the resin fine particle raw material is higher than the glass transition temperature of the binder resin contained in the toner base particles. Accordingly, the toner produced by the method of the present invention is excellent in storage stability because mutual fusion during storage is prevented. The glass transition 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 in such a temperature range, a toner having both good storage stability and fixability can be obtained.

  The volume average particle size of the resin fine particles needs to be sufficiently smaller than the average particle size of the toner base particles, and is preferably 0.05 μm or more and 1 μm or less, more preferably 0.1 μm or more and 0.5 μm or less. . When the volume average particle size is 0.05 μm or more and 1 μm or less, resin fine particles that easily adhere to the surface of the toner base particles and are easy to be softened and formed into a film can be obtained.

(3) Charge control agent-containing liquid preparation step S3
In the charge control agent-containing solution preparation step S3, a solution in which the charge control agent is dissolved is prepared. The charge control agent-containing liquid agent is used as a material for dispersing the charge control agent on the surface of the toner base particles in the charge control agent-containing liquid agent spraying step S4c of the coating step S4 described later.
As the charge control agent, charge control agents for positive charge control and negative charge control which are commonly used in this field can be used.

  Examples of the charge control agent for positive charge control 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 can be mentioned.

  Charge control agents for controlling negative charge include oil-soluble dyes such as oil black and spiron black, metal-containing azo compounds, azo complex dyes, metal salts of naphthenic acid, metal complexes and metal salts of salicylic acid, and metal complexes of salicylic acid derivatives. And metal salts, metal complexes and metal salts of bisdiphenyl glycolic acid, metal complexes and metal salts of bisdiphenyl glycolic acid derivatives (metals are chromium, zinc, zirconium, etc.), boron compounds, fatty acid soaps, long-chain alkyl carboxylates, Examples include resin acid soap.

  As the charge control agent, one kind can be used alone, or two or more kinds can be used in combination as required. Preferably, at least among the metal complex and metal salt of salicylic acid derivative, the metal complex and metal salt of bisdiphenylglycolic acid derivative, Contains one or more.

  The amount of the charge control agent used is not particularly limited and can be appropriately selected from a wide range, but is preferably 0.1 parts by weight or more and 3 parts by weight or less with respect to 100 parts by weight of the resin layer-coated toner.

  The liquid that dissolves the charge control agent and assists the adhesion of the toner base particles and resin fine particles and has the effect of plasticizing the particles without dissolving them, is not particularly limited, but the toner after spraying the liquid Since it needs to be removed from the mother particles and the resin fine particles, it is preferably a liquid that easily evaporates. Examples of such a liquid include a liquid containing a polar solvent. Examples of the polar solvent include methanol, ethanol, propanol and the like. When the liquid contains such a polar solvent, the wettability of the resin fine particles as the coating material to the toner mother particles can be improved, and the resin fine particles and the charge control agent adhere to the entire surface or most of the toner mother particles. Further, it becomes easy to deform and form a film. In addition, since the polar solvent has a high vapor pressure, the drying time when removing the liquid can be further shortened, and aggregation of the toner base particles can be suppressed.

  The viscosity of the liquid is preferably 5 cP or less. The viscosity of the liquid is measured at 25 ° C., and can be measured by, for example, a cone plate type rotary viscometer. Preferable liquids having a viscosity of 5 cP or less include alcohols such as methyl alcohol, ethyl alcohol, and propyl alcohol, and acetonitrile. Since these liquid agents have low viscosity and are easy to evaporate, it is possible to spray a liquid having a fine and uniform droplet diameter without coarsening the spray droplet diameter of the liquid sprayed from the spraying means 203. At the time of collision between the toner base particles and the liquid droplets, further refinement of the liquid droplets can be promoted. Due to the finer droplets, the surface of the toner base particles and resin fine particles are uniformly wetted and blended, the resin fine particles are softened by a synergistic effect with the collision energy, and the charge control agent is fixed inside, and it has excellent uniformity. A resin layer-coated toner can be obtained.

(4) Covering step S4
<Toner production device>
FIG. 2 is a front view showing a configuration of a toner manufacturing apparatus 201 used in the method for manufacturing a resin layer-coated toner 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. In the coating step S4, for example, using the toner manufacturing apparatus 201, the fine particle mixture prepared in the resin fine particle preparation step S2 is attached to the toner base particles prepared in the toner base particle preparation step S1, and circulation and agitation in the apparatus are performed. A resin film is formed on the toner base particles by an impact force due to a synergistic effect.

  The toner manufacturing apparatus 201 is a rotary stirring device, and 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. It is comprised including. 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. Openings 210 and 211 are formed in the stirring unit 208 which is a rotary stirring chamber. 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. Further, the opening 211 is formed on the side surface 208b perpendicular to the surface 208a on the one axial side 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 that is a circulation pipe 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. Through this powder flow path 202, toner base particles, resin fine particles and gas flow. The powder flow path 202 is provided so that the powder flow direction in which the toner base particles and the resin fine particles flow is constant.

  The temperature in the powder flow path 202 is set to be equal to or lower than the glass transition temperature of the toner base particles, more preferably 30 ° C. or higher, and becomes almost uniform in any part due to the flow of the toner base particles. When the temperature in the flow path exceeds the glass transition temperature of the toner base particles, the toner base particles are too soft and the toner base particles may aggregate. On the other hand, if the temperature is lower than 30 ° C., the drying rate of the dispersion liquid becomes slow and productivity is lowered. Therefore, in order to prevent the aggregation of the toner base particles, it is necessary to maintain the temperature of the powder flow path 202 and the rotary stirring means 204 described later below the glass transition temperature of the toner base particles. A temperature adjusting jacket, which will be described later, which is larger than the outer diameter of the tube, is disposed on at least a part of the outside of the powder flow path 202 and the rotary stirring means 204.

(Rotating stirring means)
The rotating stirring means 204 includes a rotating shaft member 218, a rotating disk 219, and a plurality of stirring blades 220. The rotary shaft member 218 has an axis that coincides with the axis of the stirring unit 208 and is formed in the surface 8c on the other side in the axial direction of the stirring unit 208 so as to penetrate the side wall including the surface 8c in the thickness direction. A cylindrical rod-like member provided so as to be inserted through 221 and rotated about an axis by a motor (not shown). The rotating disk 219 is a disk-shaped member that is supported by the rotating shaft member 218 so that its axis coincides with the axis of the rotating shaft member 218 and rotates with the rotation of the rotating shaft member 218. The plurality of stirring blades 220 are installed at the peripheral portion of the turntable 219 and rotate as the turntable 219 rotates.

  In the coating step S4, the peripheral speed of the outermost periphery of the rotary stirring means 204 is preferably set to 30 m / sec or more, and more preferably set to 50 m / sec or more. The outermost periphery of the rotary stirring means 204 is a portion 204a of the rotary stirring means 204 having the longest distance from the axis of the rotary shaft member 218 in the direction perpendicular to the direction in which the rotary shaft member 218 of the rotary stirring means 204 extends. By setting the peripheral speed at the outermost periphery of the rotary stirring means 204 to 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, and the toner base particles cannot be uniformly coated with the resin film.

  It is preferable that the toner base particles and the resin fine particles collide with the rotating disk 219 vertically. Thereby, the toner base particles and the resin fine particles are sufficiently stirred, and the toner base particles are more uniformly coated with the resin fine particles, so that the yield of the toner having a uniform coating layer can be improved.

(Spraying means)
The spray means 203 is provided so as to be inserted into an opening formed in the outer wall of the powder flow path 202, and in the powder flow portion 209, the side closest to the opening portion 211 in the flow direction of the toner base particles and the resin fine particles. It is provided in the powder flow part. The spraying unit 203 applies a mixture obtained by mixing a liquid and a carrier gas, a carrier gas supply unit for supplying a liquid, a carrier gas supply unit for supplying a carrier gas, and the toner base particles present in the powder channel 202 to the toner base particles. And a two-fluid nozzle that sprays liquid droplets onto the toner base particles. The two-fluid nozzle is provided by being inserted through an opening formed in the outer wall of the powder flow path 202. The liquid is fed to the spraying means 203 at a constant flow rate by a liquid feed pump, sprayed and gasified by the spraying means 203, and the gasified liquid spreads on the surfaces of the toner base particles and the resin fine particles. As a result, the toner base particles and the resin fine particles are plasticized.

(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 rotates and stirs in the powder flow path 202 through a cooling medium or a heating medium in the space inside the jacket. 204 is adjusted to a predetermined temperature. As a result, in the temperature adjustment step S4a described later, the temperature inside the powder flow path and outside the rotary stirring means can be controlled to a temperature at which the toner base particles and the resin fine particles are not softened and deformed. Further, in the charge control agent-containing liquid spraying step S4c and the film forming step S4d, it is possible to reduce variations in temperature applied to the toner base particles, resin fine particles, and liquid, and to maintain a stable fluid state of the toner base particles and resin fine particles. Become.

  Normally, the toner base particles and the resin fine particles collide with the inner wall of the powder flow path many times. At this time, a part of the collision energy is converted into thermal energy and accumulated in the toner base particles and the resin fine particles. As the number of collisions increases, the thermal energy accumulated in these particles increases, and the toner base particles and resin fine particles are eventually softened and adhere to the inner wall of the powder flow path. By providing the temperature adjustment jacket over the entire outside of the powder flow path 202, the temperature in the apparatus is prevented from rising rapidly, the softening of the toner base particles and the resin fine particles is suppressed, and the toner on the inner wall of the powder flow path 202 is prevented. It is possible to reliably prevent the mother particles and the resin fine particles from adhering and avoid the narrowing of the powder flow path. As a result, the toner base particles are uniformly coated with the resin fine particles, and a toner having excellent cleaning properties can be produced with a high yield.

  Further, in the powder flow part 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, so that the liquid tends to stay. When the toner base particles come into contact with this, the toner base particles are likely to adhere to the inner wall of the powder flow path 202, which causes toner aggregation. On the inner wall near the opening 210, the toner base particles flowing into the stirring section 208 from the powder flow section 209 collide with the toner base particles flowing in the stirring section 208 by the rotating stirring means 204, and the toner base particles are It tends to adhere to the vicinity of the opening 210. By providing the temperature adjusting jacket at the portion where the toner base particles are likely to adhere, it is possible to more reliably prevent the toner base particles from adhering to the inner wall of the powder flow path 202.

(Powder input part and powder recovery part)
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 the 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 mother 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 are flowed in a predetermined direction by the rotary stirring means 204. Further, 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 communicates 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 through the collection pipe 216. In addition, when the flow path in the collection pipe 216 is closed by the electromagnetic valve 217, the toner particles flowing through the powder flow path 202 are not collected.

  The coating step S4 using the toner manufacturing apparatus 201 as described above includes a temperature adjustment step S4a, a resin fine particle adhesion step S4b, a charge control agent-containing liquid agent spraying step S4c, a film forming step S4d, and a recovery step S4e. Including.

(4) -1, temperature adjustment step S4a
In the temperature adjustment step S4a, while rotating the rotary stirring means 204, the inside of the powder flow path 202 and the rotary stirring means 204 are adjusted to a predetermined temperature through a medium through a temperature adjustment jacket disposed outside them. As a result, the temperature in the powder flow path 202 can be controlled to be equal to or lower than the temperature at which the toner base particles and resin fine particles introduced in the resin fine particle attaching step S4b described later are not softened and deformed.

  In this step, it is preferable that the temperature of not only a part in the powder channel 202 but also the entire powder channel 202 and the rotary stirring means 204 is adjusted. Thereby, compared with the case where only the temperature of a part of the powder flow path is adjusted, the resin fine particles adhere to the toner base particles and form a film smoothly. Moreover, since the adhesion of these particles to the inner wall surface of the powder channel can be suppressed, it is possible to suppress the inside of the powder channel from becoming narrow. As a result, the toner base particles are uniformly coated with the resin fine particles, and a toner having a uniform film state and particle size distribution can be manufactured more stably over a long period of time.

(4) -2, resin fine particle adhesion step S4b
In the resin fine particle attaching step S4b, the toner base particles and the resin fine particles are supplied from the powder input unit 206 to the powder flow path 202 while the rotary stirring means is rotating.

  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 the arrow 214 through the powder flow section 209 of the powder flow path 202. Thereby, resin fine particles adhere to the surface of the toner base particles.

(4) -3, charge control agent-containing liquid spraying step S4c
In the charge control agent-containing liquid spraying step S4c, in the toner base particles and resin fine particles in a fluidized state, a solution in which the charge control agent is dissolved in a liquid that has an effect of plasticizing and assisting adhesion without dissolving the particles, Spraying is performed by the carrier gas from the spraying means 203 described above.

  The sprayed liquid is preferably gasified so that the gas concentration in the powder flow path 202 is constant, and the gasified liquid is preferably discharged out of the powder flow path through the through hole 221. By keeping the concentration of the gasified liquid constant, the drying speed of the liquid can be increased as compared with the case where the concentration is not kept constant. Therefore, the toner particles in which the undried liquid remains can be prevented from adhering to each other, and aggregation of the toner particles can be suppressed. As a result, the yield of toner with a uniform coating layer can be further improved.

  The concentration of the gasified liquid measured by the concentration sensor in the gas discharge unit 222 is preferably about 3% or less. When the concentration is about 3% or less, the drying speed of the liquid can be sufficiently increased, the remaining toner base particles of the undried liquid can be prevented from adhering to each other, and aggregation of the toner base particles can be suppressed. Further, the concentration of the gasified liquid is more preferably 0.1% or more and 3.0% or less. When the liquid concentration is within such a range, aggregation of toner mother particles can be prevented without reducing productivity. The concentration of the liquid is adjusted according to the type and amount of the raw materials for the toner base particles and the resin fine particles. It can also be adjusted by changing the spraying speed of the liquid according to the scale of the toner manufacturing apparatus 201.

  In the present embodiment, it is preferable to start spraying after the surface of the toner base particles and the flow rate of the resin fine particles in the powder flow path 202 are stabilized. Thereby, the liquid can be uniformly sprayed on the toner base particles and the resin fine particles, and the yield of the toner having a uniform coating layer can be improved.

(Carrier gas)
Compressed air or the like can be used as the carrier gas. The flow rate of the carrier gas is appropriately adjusted according to the spraying speed of the liquid. The preferable flow rate of the carrier gas depends on the spraying speed of the liquid, and varies depending on the scale of the toner manufacturing apparatus 201 and the amount of toner base particles and resin fine particles.

  An angle θ formed between the liquid spraying direction which is the axial direction of the two-fluid nozzle of the spraying means 203 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 It is preferable that the angle is not more than °. When θ is within such a range, liquid droplets are prevented from recoiling on the inner wall of the powder flow path 202, and the yield of toner mother particles coated with the resin film can be further improved. . If θ exceeds 45 °, the liquid droplets recoil on the inner wall of the powder flow path 202, the liquid tends to stay, the toner particles aggregate, and the yield deteriorates.

  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 liquid onto the toner base particles.

  In this process, by using the two-fluid nozzle having the above-described structure, the center of the liquid pipe and the air pipe is shifted even if the circulating air and the circulating toner mother particles and resin fine particles collide with the two-fluid nozzle. Can be prevented. Thereby, in the cross section of the tip of the air pipe, the amount of the carrier gas to be sprayed per unit area becomes constant, the direction of the sprayed liquid and the spray amount can be kept constant, and the spray state can be stably maintained. Accordingly, it is possible to stably produce a toner having a uniform film state and particle size distribution over a long period of time while keeping the liquid concentration in the powder flow path constant.

(4) -4, film forming step S4d
In the film forming step S4d, the rotation stirring means 204 is continuously rotated at a predetermined temperature until the resin fine particles are softened and formed into a film, and the toner mother particles and the resin fine particles are flowed, and the toner mother particles are coated with the charge control agent-containing resin layer. To do.

(4) -5, Recovery step S4e
In the collection step S4e, the liquid spray from the spray unit and the rotation of the rotary stirring unit 204 are stopped, and the charge control agent-containing resin layer-coated toner is discharged from the powder recovery unit 207 to the outside and collected.

  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 outer surface of the powder flow part 209 and the stirring part 208, or may be provided on a part of the powder flow part 209 or the outside of the stirring part 208. . When the temperature adjustment jacket is provided on the entire outer surface of the powder flow part 209 and the stirring part 208, it is possible to more reliably prevent the toner base particles from adhering to the inner wall of the powder flow path 202.

  Further, the toner manufacturing apparatus can be configured 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 a liquid spray unit in such a stirring device, this stirring device can be used as a toner manufacturing apparatus used for manufacturing the toner of the present invention.

2. Toner A toner according to an embodiment of the present invention is manufactured by the above-described toner manufacturing method. Since the toner obtained by the above-described toner manufacturing method has a uniform coating amount of the charge control agent and the resin fine particles, toner characteristics such as charging characteristics between individual toner particles are uniform. The toner of the present invention is excellent in durability because the encapsulated component is protected by the surface charge control agent-containing resin layer. Therefore, when such a toner is used for image formation, a high-definition and good-quality image without uneven density can be obtained.

  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 silicon 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 Since the developer which is an embodiment of the present invention contains the toner described above, the toner characteristics are uniform and good developability can be maintained. The developer of the present invention 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. Further, using a blade and a fur brush, the toner is conveyed by frictional charging with the developing sleeve and the toner is deposited on the sleeve, thereby forming an image. When used as a two-component developer, the above toner is used together with a carrier.

  As the carrier, a known carrier can be used, for example, a resin-coated carrier in which the surface of single or composite ferrite and carrier core particles made of iron, copper, zinc, nickel, cobalt, manganese, chromium, etc. are coated with a coating substance, or Examples thereof include a resin-dispersed carrier in which magnetic particles are dispersed in a resin.

  Known coating materials can be used, such as polytetrafluoroethylene, monochlorotrifluoroethylene polymer, polyvinylidene fluoride, silicon 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. The resin used for the resin dispersion carrier is not particularly limited, and examples thereof include styrene acrylic resin, polyester resin, fluorine resin, and phenol resin. Either of them is preferably selected according to the toner component, and one kind can be used alone, or two or more kinds 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.

The volume resistivity of the carrier is preferably 10 ⁸ Ω · cm or more, and more preferably 10 ¹² Ω · cm or more. The volume resistivity is determined by placing a carrier in a container having a cross-sectional area of 0.50 cm ² and tapping it, then applying a load of 1 kg / cm ² to the particles packed in the container and applying 1000 V between the load and the bottom electrode. This is a value obtained from a current value when a voltage generating an electric field of / cm is applied. If the resistivity is low, the carrier is charged when a bias voltage is applied to the developing sleeve, the carrier particles are likely to adhere to the photoreceptor, and the 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. Under a general developing roller magnetic flux density condition, if it is less than 10 emu / g, the magnetic binding force does not work, which may cause carrier scattering. On the other hand, if the magnetization strength exceeds 60 emu / g, the carrier spikes become too high in the non-contact development, and it becomes difficult to maintain the non-contact state between the image carrier and the toner. 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. For example, when mixed with a resin-coated carrier (density 5 to 8 g / cm ² ), the toner may be contained in an amount of 2 to 30% by weight, preferably 2 to 20% by weight based on the total amount of developer. Further, the coverage of the carrier with the toner is preferably 40 to 80%.

  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 volume average particle diameters of the sample particles in the examples and comparative examples were measured as follows.

[Volume average particle size]
To 50 ml of electrolytic solution (trade name: ISOTON-II, manufactured by Beckman Coulter, Inc.), 20 mg of sample and 1 ml of alkyl ether sulfate ester are added, and an ultrasonic disperser (trade name: UH-50, manufactured by SMT Co., Ltd.) is used. The sample was subjected to dispersion treatment at an ultrasonic frequency of 20 kHz for 3 minutes to obtain a measurement sample. This sample for measurement is measured using a particle size distribution measuring device (trade name: Multisizer 3, manufactured by Beckman Coulter, Inc.) under the conditions of an aperture diameter of 100 μm and the number of measured particles of 50000, and the volume from the volume particle size distribution of the sample particles. The average particle size was determined.

Example 1
<Toner base particle production process>
Polyester resin (trade name: Diacron, manufactured by Mitsubishi Rayon Co., Ltd., glass transition temperature 56 ° C., softening temperature 130 ° C.) 89.0% (8900 parts)
-Colorant C.I. I. Pigment Red 57: 1 5.0% (500 parts)
Release agent (carnauba wax, melting point 82 ° C.) 6.0% (600 parts)

  The above raw materials were 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 coarsely pulverized with a cutting mill (trade name: VM-16, manufactured by Orient Co., Ltd.), then finely pulverized with a jet mill (manufactured by Hosokawa Micron Co., Ltd.), and further with an air classifier (manufactured by Hosokawa Micron Co., Ltd.). Classification was performed to prepare toner base particles having a volume average particle size of 6.9 μm and a glass transition temperature of 56 ° C.

<Resin fine particle and charge control agent-containing liquid preparation process>
Styrene-butyl acrylate-acrylic acid copolymer fine particles (glass transition temperature 64 ° C.) having a volume average particle size of 0.1 μm were prepared as resin fine particles. In addition, a charge control agent (trade name: LR-147, manufactured by Nippon Carlit Co., Ltd.), which is a metal complex and metal salt of a salicylic acid dielectric, was prepared, and ethanol was prepared as a liquid for plasticizing the mother particles and resin fine particles. The charge control agent LR-147 was dissolved in ethanol to prepare resin fine particles and a charge control agent-containing liquid agent.

<Coating process>
100 parts of toner base particles and 10 parts of resin particles are put into a surface modification device (trade name: Hybridization System NHS-1 type, manufactured by Nara Machinery Co., Ltd.) equipped with a two-fluid nozzle that can spray liquid in the container. And kept at a rotational speed of 8000 rpm for 10 minutes. Thereafter, compressed air is sent to the two-fluid nozzle, and 20 parts of an ethanol solution (0.5 wt%) of the charge control agent LR-147 (0.1 part) is sprayed at 0.5 g / min for 40 minutes to obtain a toner base. The entire surface of the particles was coated with resin fine particles and a charge control agent.

  The toner base particles having the coating layer formed on the surface in this manner were lyophilized to obtain the toner of Example 1.

(Example 2)
A toner of Example 2 was obtained in the same manner as in Example 1 except that 20 parts of an ethanol solution (5 wt%) of the charge control agent LR-147 (1 part) was added in the coating step.

(Example 3)
A toner of Example 3 was obtained in the same manner as in Example 1 except that 20 parts of the charge control agent LR-147 (2 parts) ethanol solution (10 wt%) was added in the coating step.

Example 4
The toner of Example 4 was obtained in the same manner as in Example 2, except that 20 parts of an ethanol solution (5 wt%) of the charge control agent LR-147 (1 part) was added in the toner base particle preparation step.

(Example 5)
In the coating step, instead of the charge control agent LR-147, a metal complex of a bisdiphenylglycolic acid derivative and a metal salt of a charge control agent BONTRON E-84 (0.1 part) in an ethanol solution (0.5 wt%) 20 parts A toner of Example 5 was obtained in the same manner as Example 1 except that was added.

(Example 6)
The toner of Example 6 was obtained in the same manner as in Example 5, except that 20 parts of an ethanol solution (5 wt%) of the charge control agent BONTRON E-84 (1 part) was added in the coating step.

(Example 7)
The toner of Example 7 was obtained in the same manner as in Example 5, except that in the coating step, 20 parts of the charge control agent BONTRON E-84 (2 parts) ethanol solution (10 wt%) was added.

(Comparative Example 1)
A toner of Comparative Example 1 was obtained in the same manner as in Example 1 except that no charge control agent was added in the coating step.

(Comparative Example 2)
A toner of Comparative Example 2 was obtained in the same manner as in Example 2 except that the resin fine particles were not added in the coating step.

(Comparative Example 3)
A toner of Comparative Example 3 was obtained in the same manner as Comparative Example 2, except that 20 parts of an ethanol solution (5 wt%) of the charge control agent LR-147 (1 part) was added in the toner base particle preparation step.
Table 1 summarizes the toner compositions of Examples and Comparative Examples.

<Preparation of two-component developer>
100 parts of the toners of the examples and comparative examples obtained as described above were mixed with 0.7 parts of silica particles having an average primary particle diameter of 20 nm hydrophobized with a silane coupling agent and 0.5 parts of titanium oxide. Thus, an externally added toner was obtained. Further, the externally added toner and the ferrite core carrier (volume average particle diameter of 60 μm) are adjusted so that the toner concentration becomes 7 wt% (weight mixing ratio of the toner in the total weight of the developer). The two-component developer was prepared by mixing and stirring at 100 rpm for 1 hour on a double-shaft driven plastic bottle rotating stand.

The toners of Examples and Comparative Examples were evaluated as follows.
[Aging conditions]
Using a two-component developer produced under the above-described conditions, a digital full-color MFP MX-6200N manufactured by Sharp Corporation was used, and 20k (20,000) sheets of images with a printing rate of 10% were continuously printed.

  The DC bias value of the bias voltage applied to the developer carrying member was appropriately changed according to the charge amount of the toner in each developer, and was adjusted so that the image density of the solid image became a specified value. The toner consumption amount due to visible image formation is detected by a toner density sensor as a change in toner density. Since the consumed toner is replenished from the toner hopper until the specified toner concentration is reached, the toner concentration in the two-component developer inside the developing unit is kept substantially constant.

[Toner charge amount, image density and toner scattering]
Aging was performed under the above conditions, the image density was measured, and the toner charge amount and toner scattering were measured and evaluated.

  The image density is a value obtained by measuring the density of a solid image obtained when the above-described DC bias value of the bias voltage is −600 V using an X-Rite 939 spectrocolorimetric densitometer.

  The amount of charge was measured with a suction-type charge amount measuring device 210H-2A Q / M Meter (TREK) by collecting a two-component developer at each measurement, and the difference in charge amount between the initial value and after printing 20k sheets is 10 If it is small, it is “◯”, and if it is 10 or more, it is “x”.

The toner scattering was evaluated by the following criteria, after the idling operation was performed for 2 minutes without forming an image at each measurement point, and the toner adhesion amount on the housing portion above the developing unit was visually confirmed.
○: Conspicuous toner scattering is not observed ×: Toner scattering is entirely present

〔Comprehensive evaluation〕
In the overall evaluation, regarding both the charge amount and the toner scattering, if both are “◯”, it is “◯”, and if one is “×”, it is “×”.

  Table 2 shows the results of image density, toner charge amount, and toner scattering at 0 k, 10 k, and 20 k in the continuous printing process.

  For all of the toners of Examples and Comparative Examples, the image density was 1.4 or higher, which was good.

  In the toners of Examples 1 to 7, there was almost no decrease in the charge amount after aging, the charge rising state was good, the chargeability was excellent, and the toner was not scattered.

  Since the toner of Comparative Example 1 does not contain a charge control agent, it is considered that the charge amount after aging is low and the charge rise is slow. In addition, toner scattering occurred. Since the toners of Comparative Examples 2 and 3 contained a charge control agent but no resin layer, the charge amount after aging was low and toner scattering occurred.

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 (6)

A rotating stirring means including a rotating disk having a stirring blade and a rotating shaft; and a powder flow path including a rotary stirring chamber and a circulation pipe. Circulation means for repeatedly circulating particles and resin fine particles;
A temperature adjusting means provided in at least a part of the powder flow path for adjusting the powder flow path and the rotary stirring means to a predetermined temperature;
Resin layer using a rotary stirrer comprising at least spraying means including a two-fluid nozzle comprising a liquid tube for spraying a liquid for assisting adhesion between toner mother particles and resin fine particles and an air tube for spraying a carrier gas In the method for producing a coated toner,
While the toner base particles and the resin fine particles are stirred and circulated in the temperature-adjusted powder flow path, a liquid that does not dissolve the toner base particles and the resin fine particles but is plasticized is used as the liquid. layer coated toner 100 parts by weight 3 parts by weight to by the Hare dissolve and become less than 0.1 parts by weight relative to the spray at a constant speed in the powder passage in the two-fluid nozzle, the toner base particle surfaces the method of tree fat layer coated toner you, characterized in that to form a resin layer containing a resin particulate charge control agent. The charge control agent, the production method of the resin layer coated toner according to 請 Motomeko 1 you, characterized in that contained in the inner resin layer of the resin layer coated toner. The charge control agent, a metal complex and a metal salt of a salicylic acid derivative, of the metal complex and the metal salt of bis diphenyl glycolic acid derivative, the resin according to 請 Motomeko 1 or 2 you characterized in that it comprises at least one A method for producing a layer-coated toner. Toner mother particles and liquid for assisting the adhesion of the resin fine particles, method for producing a resin layer coated toner according to any one of 請 Motomeko 1-3 you characterized in that it comprises at least a polar solvent.   A resin layer-coated toner produced by the toner production method according to claim 1.   A two-component developer comprising the resin layer-coated toner according to claim 5 and a carrier.

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