JP2011191405A - Fluorescence toner and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescence toner having high transparency and excellent emission efficiency, and to provide a manufacturing method therefor. <P>SOLUTION: The method for manufacturing the fluorescence toner includes: the process for spraying fluorescence dye containing solution for forming wet composite particles adhered by resin fine particles and the fluorescence dye containing solution on the surfaces of toner base particles by spraying the fluorescence dye containing solution including a fluorescence dye and a solvent toward composite particles while circulating the composite particles adhered by the resin fine particles on the surfaces of the toner base particles in an air flow; and the filming process for removing the solvent by circulating the wet composite particles in the air flow to film the resin fine particles and the fluorescence dye on the surfaces of the toner base particles. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a toner containing a fluorescent material and a method for producing the same. More specifically, the present invention relates to a fluorescent toner having high transparency and excellent luminous efficiency, and a method for producing the same.

  In order to prevent unauthorized copying, a method of forming an image by an electrophotographic image forming apparatus using a transparent fluorescent toner to which a fluorescent material that develops a color by irradiating ultraviolet rays of a predetermined wavelength is known. Yes.

  As a method for producing a fluorescent toner, for example, in JP-A-2006-251389 (Patent Document 1), a zinc oxide fine powder as a fluorescent substance is added to a polyester resin together with a charge control agent and a wax, and transparent by a kneading and pulverizing method. A method of manufacturing a fluorescent toner is disclosed.

  Japanese Patent Application Laid-Open No. 2003-107803 (Patent Document 2) discloses a method for producing a transparent fluorescent toner by a kneading and pulverizing method in which a coumarin derivative or a naphthalimide derivative is added to a polyester resin together with a charge control agent and a wax as a fluorescent substance. Is disclosed.

JP 2006-251389 A JP 2003-107803 A

  However, it is difficult to finely disperse an inorganic fluorescent material such as zinc oxide fine powder in a binder resin such as a polyester resin (for example, a particle diameter of 0.2 μm or less), and the transparency of the obtained toner is lowered. There was a problem.

  In addition, organic fluorescent substances such as coumarin derivative fine powder can be finely dispersed (or dissolved) in a binder resin such as a polyester resin by using a compound having a low melting point. There was a problem that the more finely dispersed (or dissolved) the substance, the lower the luminous efficiency due to the interaction with the resin.

  The present invention has been made in view of the above problems, and provides a fluorescent toner having high transparency and excellent luminous efficiency and a method for producing the same.

  Thus, according to the present invention, a fluorescent dye-containing solution containing a fluorescent dye and a solvent is sprayed toward the composite particles while circulating the composite particles having resin fine particles attached to the surface of the toner base particles in an air stream. A fluorescent dye-containing solution spraying step for forming wet composite particles in which the resin fine particles and the fluorescent dye-containing solution adhere to the surface of the toner base particles, and circulating the wet composite particles in the air stream to remove the solvent. There is provided a method for producing a fluorescent toner, comprising a film forming step of removing and forming a film of the resin fine particles and the fluorescent dye on the surface of the toner base particles.

  Moreover, according to the present invention, there is provided a fluorescent toner obtained by the production method.

  By using the production method of the present invention, absorption and scattering of visible light by the crystal particles can be suppressed, and since the interaction with the binder resin can be suppressed, transparency is high and luminous efficiency is improved. An excellent fluorescent toner can be obtained.

  According to the present invention, the fluorescent dye-containing solution spraying step and the film-forming step include a circulation means for circulating the composite particles or wet composite particles in the air stream, and fluorescence for the composite particles or wet composite particles circulating in the air stream. Repeatedly and continuously using a toner production apparatus having a spraying means for spraying a fluorescent dye-containing solution containing a dye and a rotary stirring means for applying impact force to the composite particles circulating in the air stream or the wet composite particles In this case, when the resin fine particles and the fluorescent dye are formed on the surface of the toner base particles, aggregation of the wet composite particles can be suppressed, and the production efficiency of the fluorescent toner can be improved.

  According to the present invention, when the solvent includes ethanol and the fluorescent dye includes one of coumarin and a coumarin derivative, the resin fine particles and the fluorescent dye are formed on the surface of the toner base particles while suppressing aggregation of the wet composite particles. The production efficiency of fluorescent toner can be improved.

  According to the present invention, when the toner base particles have a volume average particle size of 4 μm or more and 8 μm or less, and the resin fine particles have a number average particle size of 0.2 μm or more and 0.5 μm or less, the toner base particles and the resin An appropriate fine space is formed in the gap between the fine particles, and the fluorescent dye sprayed on the surface of the composite particle in a state of being dissolved in the solution forms appropriate fine crystal particles in such a fine space. A fluorescent toner having high transparency and excellent luminous efficiency can be obtained.

  According to the present invention, when the airflow includes compressed air, the fluorescent toner can be manufactured more safely.

  According to the present invention, when the fluorescent dye-containing solution is sprayed continuously or discontinuously, the aggregation of wet composite particles can be further suppressed, and the production efficiency of the fluorescent toner can be further improved.

  According to the present invention, a fluorescent toner having high transparency and excellent luminous efficiency can be obtained.

5 is a flowchart illustrating an example of a procedure of a toner manufacturing method according to the present invention. 1 is a schematic cross-sectional view showing a toner manufacturing apparatus of the present invention. It is a schematic sectional drawing of the cross section of A200-A200 of FIG. It is a schematic sectional drawing which shows the powder flow path (circulation means) of the manufacturing apparatus of this invention. FIG. 3 is a schematic diagram illustrating a toner of the present invention.

  Hereinafter, it will be as follows if one Embodiment of this invention is described based on FIGS. In this embodiment, a transparent fluorescent toner can be manufactured using the fluorescent toner manufacturing method according to the present invention.

  FIG. 1 is a process diagram showing an example of the procedure of a toner manufacturing method according to the present invention. As shown in FIG. 1, in the procedure of the toner manufacturing method, the toner mother particle preparation step S1, the resin fine particle preparation step S2, the fluorescent dye-containing solution preparation step S3, the fluorescent toner particle preparation step S4, An external addition step S5 is included.

FIG. 5 is a schematic view of the fluorescent toner of the present invention manufactured by the toner manufacturing method according to the present invention. As shown in FIG. 5, the fluorescent toner 10 has a fluorescent dye-containing resin film (coating layer) 12 containing a resin and a fluorescent dye 13 on the surface of toner base particles 11, and the fluorescent dye 13 is a fluorescent dye-containing resin. The film 12 is uniformly dispersed without agglomeration.
Hereinafter, each step will be described.

(1) Toner mother particle production step S1
In the toner base particle preparation step S1, toner base particles 11 that are the core of the fluorescent toner 10 shown in FIG. 5 are prepared. The toner base particles 11 are particles containing a binder resin, and may further contain an additive (not shown) such as a colorant, a release agent, or a charge control agent, if necessary. The method for producing the toner base particles 11 is not particularly limited, and can be performed by a known method. For example, there can be mentioned wet methods such as a dry method such as a pulverization method, 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 the toner base particles 11 by the pulverization method will be described.

  In the production of the toner base particles 11 by the pulverization method, the composition of the toner base particles 11 to which the binder resin and, if necessary, the additives are added, 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, the toner base particles 11 can be obtained by adjusting the particle size such as classification as required.

  Known mixers can be used, for example, Henschel mixer (trade name, manufactured by Mitsui Mining Co., Ltd.), Super Mixer (trade name, manufactured by Kawata Co., Ltd.), Mechano Mill (trade name, Okada Seiko Co., Ltd.) Henschel type mixing equipment such as company-made), Ongmill (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.), etc. Can be mentioned.

  As the kneader, known ones can be used, and examples thereof include general kneaders such as a twin-screw extruder, a three-roller, and a lab blast mill. More specifically, for example, uniaxial or biaxial 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.) An open roll type kneader such as Extruder or Kneedex (trade name, manufactured by Mitsui Mining Co., Ltd.) can be used. Among these, an open roll kneader is particularly preferable.

  A well-known thing can be used as a grinder, for example, a jet type grinder which grinds using a supersonic jet stream, or a rotor (rotor) and a stator (liner) which rotate at high speed. Examples thereof include an impact pulverizer that introduces a solidified material into a space formed therebetween and pulverizes it.

  For the classification, a known classifier that removes excessively pulverized toner base particles by centrifugal force and wind classification can be used. For example, a swirling wind classifier (rotary wind classifier) or the like can be used. be able to.

(Binder resin)
The binder resin is not particularly limited, and known binder resins for color toners and black toners can be used. For example, amorphous polyester resin, crystalline polyester resin, polystyrene, poly- α-methylstyrene, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer Styrene resins such as polymers, epoxy resins, urethane modified epoxy resins, rosin modified maleic acid resins, phenyl resins, polyethylene, polypropylene, ionomer resins, polyurethane resins, ethylene-ethyl acrylate copolymers, terpene resins, phenol resins, fats Aromatic or alicyclic hydrocarbon resin It is possible.

  Alternatively, a resin obtained by mixing a release agent with a raw material monomer mixture and performing a polymerization reaction may be used. Binder resin can be used individually by 1 type, and may use 2 or more types together.

  In particular, amorphous polyester resin and crystalline polyester resin, and mixed resins thereof are excellent in transparency, and can impart good powder fluidity, low-temperature fixability, secondary color reproducibility and the like to the toner. Therefore, it is suitable for a binder resin for transparent fluorescent toner.

  As a polyester resin, a well-known thing can be used, For example, the polycondensate of a polybasic acid and a polyhydric alcohol etc. can be mentioned. Polybasic acids are polybasic acids and derivatives of polybasic acids, such as acid anhydrides or esterified products of polybasic acids, and polyhydric alcohols are compounds containing two or more hydroxyl groups. Yes, including both alcohols and phenols.

  As the polybasic acid, those known as monomers for polyester resins can be used. For example, aromatic carboxylic acids such as terephthalic acid, isophthalic acid, phthalic anhydride, trimellitic anhydride, pyromellitic acid, naphthalenedicarboxylic acid, etc. And aliphatic carboxylic acids such as maleic anhydride, 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, and may use 2 or more types together.

As the polyhydric alcohol, those known as polyester resin monomers can be used, for example, aliphatic polyhydric alcohols such as ethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, glycerin, Aromatic diols such as cycloaliphatic polyhydric alcohols such as cyclohexanediol, cyclohexanedimethanol and hydrogenated bisphenol A, ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, and the like can be mentioned. A polyhydric alcohol can be used individually by 1 type, and may use 2 or more types together.
Moreover, it is preferable to select the physical properties of various resins so that the physical properties of the obtained binder resin are as follows.

  The glass transition temperature (Tg) of the binder resin is not particularly limited and can be appropriately selected from a wide range, but is 30 ° C. or higher and 80 ° C. or lower in consideration of the fixing property and storage stability of the obtained toner. Is preferred. When the temperature is less than 30 ° C., the storage stability becomes insufficient, so that the toner is likely to thermally aggregate inside the image forming apparatus, and development failure may occur. On the other hand, if the glass transition temperature exceeds 80 ° C., the fixing property may be deteriorated and fixing failure may occur.

  The molecular weight of the binder resin is usually designed in consideration of low-temperature fixability, hot offset resistance, and fixing strength, but the weight average molecular weight (Mw) is preferably 5,000 or more and 500,000 or less. . Here, the weight average molecular weight of the binder resin is a value converted on the basis of polystyrene analyzed simultaneously by gel permeation chromatography (GPC).

  When the weight average molecular weight is less than 5,000, the mechanical strength of the binder resin is lowered, and the resulting toner particles are easily pulverized by stirring inside the developing device, and the charging performance is likely to vary. Hot offset is likely to occur. “Hot offset phenomenon” means that when toner is fixed on a recording sheet by heating and pressing with a fixing member such as a heating roller, the cohesive force between toner particles is less than the adhesive force between the toner and the fixing member due to overheating of the toner. This is a phenomenon in which a part of the toner adheres to and is removed from the fixing member because the toner layer is divided. Moreover, since it becomes difficult to melt when the weight average molecular weight exceeds 500,000, kneading in the kneading step becomes difficult, and the dispersibility of the colorant, release agent, charge control agent and the like in the kneaded product is impaired. Low temperature fixability of the toner is lowered, and fixing failure is likely to occur.

(Coloring agent)
The colorant may be added when producing a color toner or a black toner other than the transparent toner. 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 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 magenta colorant include the color index name C.I. I. Pigment red 49, C.I. I. Pigment red 57, C.I. I. Pigment red 81, C.I. I. Pigment red 122, C.I. I. Solvent Red 19, C.I. I. Solvent Red 49, C.I. I. Solvent Red 52, C.I. I. Basic Red 10 and C.I. I. Disperse Red 15 etc. can be mentioned.

  Examples of the cyan colorant include the color index name C.I. I. Pigment blue 15, C.I. I. Pigment blue 16, C.I. I. Solvent Blue 55, C.I. I. Solvent Blue 70, C.I. I. Direct Blue 25, and C.I. I. Direct Blue 86 and the like can be mentioned.

  Examples of the black colorant include carbon black such as channel black, roller black, disk black, gas furnace black, oil furnace black, thermal black, and acetylene black.

  Examples of the white colorant include compounds such as zinc white, titanium oxide, antimony white, and zinc sulfide. The colorant can be used alone or in combination of two or more different colors. Further, two or more of the same color may be used in combination.

  The content of the colorant is not particularly limited, but is preferably 4 parts by weight or more and 20 parts by weight or less with respect to 100 parts by weight of the binder resin. As a result, an unfavorable filler effect due to the addition of the colorant can be suppressed, and a toner having high coloring power can be obtained. When the blending amount of the colorant exceeds 20 parts by weight, the fixability of the toner may be lowered due to the filler effect of the colorant. Moreover, sufficient coloring may not be acquired as it is less than 4 weight part.

  The colorant may be used as a master batch in order to uniformly disperse it in the binder resin. A master batch of a colorant can be produced, for example, by kneading a resin melt and a colorant. As the resin, the same type of resin as the binder resin or a resin having good compatibility with the binder resin is used. The use ratio of the resin and the colorant in the master batch is not particularly limited, but is preferably 30 parts by weight or more and 100 parts by weight or less with respect to 100 parts by weight of the synthetic resin. The master batch is used after being granulated to a particle size of about 2 mm or more and 3 mm or less, for example.

  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, polar solvent or the like to two or more 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.

(Release agent)
The release agent is added as necessary for the purpose of imparting releasability to the toner when the toner is fixed on the recording sheet. The addition of the release agent increases the high temperature offset start temperature, so that the hot offset phenomenon may be difficult to occur. Further, since the release agent can be melted by heating at the time of toner fixing and the melting temperature of the toner can be lowered, the low temperature offset start temperature can be lowered and the fixing temperature can be lowered. “Low-temperature offset phenomenon” means that when a toner is fixed to a recording sheet by heating and pressing with a fixing member such as a heating roller, the toner is not sufficiently melted, and the adhesive force between the toner and the recording sheet This is a phenomenon in which a part of the toner adheres to and is removed from the fixing member in order to be less than the adhesive force.

  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-based synthetic 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 derivatives thereof, plant waxes such as wood wax, animal waxes such as beeswax and whale wax, oils such as fatty acid amides and phenol fatty acid esters System synthetic waxes, long-chain carboxylic acids and their derivatives, long-chain alcohols and derivatives thereof, silicone polymers, can be mentioned higher fatty acid and the like. 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 release agent used is not particularly limited and can be appropriately selected from a wide range, but is preferably 0.2 parts by weight or more and 20 parts by weight or less, more preferably 100 parts by weight of the binder resin. It is 0.5 parts by weight or more and 10 parts by weight or less, and particularly preferably 1.0 part by weight or more and 8.0 parts by weight. If the release agent is contained in an amount of more than 20 parts by weight, filming on the photoreceptor and spent on the carrier may easily occur. Further, if it is less than 0.2 parts by weight, the function of the release agent may not be sufficiently exhibited.

  The melting point of the release agent is not particularly limited, but is preferably 30 ° C or higher and 120 ° C or lower. When the melting point exceeds 120 ° C., the fixability (releasability) is not improved, and when it is less than 30 ° C., the storage stability of the toner may be impaired.

(Charge control agent)
The charge control agent is added as necessary for the purpose of imparting preferable chargeability to the toner. The charge control agent is not particularly limited, and charge control agents for positive charge control and negative charge control commonly used in this field can be used.

  Examples of charge control agents 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, 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.
One charge control agent can be used alone, or two or more charge control agents may be used in combination 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 0.5 parts by weight or more and 5 parts by weight or less with respect to 100 parts by weight of the binder resin, More preferably, it is 0.5 part by weight or more and 3 parts by weight or less with respect to 100 parts by weight of the binder resin. When the charge control agent exceeds 5 parts by weight, the carrier is contaminated and toner scattering may occur. Further, when the content of the charge control agent is less than 0.5 parts by weight, it may not be possible to impart sufficient chargeability to the toner.

  The toner base particles 11 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 toner base particles 11 within this range, it is possible to obtain a high image density even if the amount of adhesion is small, and to reduce the toner consumption. When the volume average particle size of the toner base particles 11 is less than 4 μm, the particle size is small, and thus high charging and low fluidization may occur. Further, when the toner is highly charged and fluidized, the toner cannot be stably supplied to the photosensitive member, and background fogging and a decrease in image density may occur. If the volume average particle size of the toner base particles 11 exceeds 8 μm, the particle size is large, so that the layer thickness of the formed image increases and a high-definition image may not be obtained.

(2) Resin fine particle preparation step S2
In the resin fine particle preparation step S2, dry resin fine particles are prepared which are fused to the surface of the toner base particles 11 to form the fluorescent dye-containing resin film 12 shown in FIG. The resin fine particles are used as a material for forming the fluorescent dye-containing resin film 12 on the surface of the toner base particles 11 in the fluorescent toner particle preparation step S4 described later. In addition, what kind of method may be used for drying, for example, dry resin microparticles | fine-particles can be obtained by methods, such as hot-air heat receiving type drying, conduction heat transfer type drying, far-infrared drying, and microwave drying.

  As the raw material for the resin fine particles, resins generally used for toner materials can be used, and examples thereof include polyester, acrylic resin, styrene resin, and styrene-acrylic copolymer. Among these raw materials for the resin fine particles, it is particularly preferable to contain 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 sizes.

  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. Moreover, it can obtain also by superposition | polymerization of the monomer component of resin. The polymerization production method of resin fine particles is not particularly limited, and for example, a suspension polymerization method, an emulsion polymerization method and the like can be used, and a soap-free emulsion polymerization method is preferable. According to the soap-free emulsion polymerization method, particles having a narrow particle size distribution are obtained.

  Examples of the vinyl type include styrenes such as styrene, o-methyl styrene, m-methyl styrene, p-methyl styrene, p-ethyl styrene, and p-chloro styrene, and ethylene unsaturated such as ethylene, propylene, butylene, and isobutylene. Monoolefins, vinyl halides such as vinyl chloride, vinyl esters such as vinyl acetate, methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, n-octyl acrylate, acrylic Dodecyl acid, 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, propyl methacrylate, n-octyl methacrylate, dodemethacrylate , Α-methylene aliphatic monocarboxylic esters such as 2-ethylhexyl methacrylate, stearyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, (meth) acrylic acid derivatives such as acrylonitrile, methacrylonitrile acrylamide, Examples thereof include vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, and vinyl isobutyl ether. Among these, styrenes are preferable, and styrene is particularly preferable. A vinyl monomer can be used individually by 1 type, and may use 2 or more types together.

  When different types of resins are used as the resin fine particle raw material, 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 11 and is 50 ° C. or higher and 70 ° C. or lower. Preferably there is. As a result, mutual fusion during storage of the toner is prevented, so that storage stability can be improved.

  The softening temperature of the resin fine particles depends on the image forming apparatus in which the toner is used, but is preferably 80 ° C. or higher and 140 ° C. or lower. By using resin fine particles in such a temperature range, a toner having both good storage stability and fixability can be obtained.

  Further, the amount of resin fine particles used is not particularly limited, but an amount in which the surface of the toner base particles is coated with one layer of resin fine particles is preferable. The optimum addition amount varies depending on the particle size and shape of the toner base particles and the resin fine particles, and the optimum amount is selected by experiment. Usually, the addition amount of the resin fine particles is 3 to 10 parts by weight with respect to 100 parts by weight of the toner base particles.

  The resin fine particles preferably have a number average particle diameter of 0.2 μm or more and 0.5 μm or less. When the number average particle diameter is 0.2 μm or more and 0.5 μm or less, it becomes easy to form a homogeneous film on the surface of the toner base particles.

(3) Fluorescent dye-containing solution preparation step S3
In the fluorescent dye-containing solution preparation step S3, a fluorescent dye-containing solution in which the fluorescent dye 13 shown in FIG. 5 is dissolved is prepared.

(Fluorescent dye)
The fluorescent dye 13 is preferably colorless or white under visible light so as not to affect the color or the like. Further, since the fluorescent dye 13 is used in a state of being dissolved in the solvent of the fluorescent dye-containing solution, it is necessary to be soluble in the solvent used, and there is a fluorescent dye that dissolves at least 10 g per 1 kg of the solvent. preferable.

  Specific examples of fluorescent dyes include coumarin, sodium 4,4′-bis (4-phenyl-1,2,3-triazol-2-yl) stilbene-2 ′, 2′-disulfonate, 3-phenyl- 7- (4-Methyl-5-phenyl-1,2,3-triazol-2-yl) coumarin, 3-phenyl-7- (2H-naphtho [1,2-d] -triazol-2-yl) coumarin , 1- (4-acidsulfonylphenyl) -3- (4-chlorophenyl) -2-pyrazoline and other coumarin derivatives, naphthalimide derivatives, stilbene derivatives, benzothiazole derivatives, benzimidazole derivatives, benzoxazole derivatives, benzidine derivatives and the like. Of these, coumarin and coumarin derivatives are preferred.

  The concentration of the fluorescent dye-containing solution is preferably such that the fluorescent dye is dissolved in an amount of 10 g to 50 g with respect to 1 kg of the solvent. The spray amount of the fluorescent dye-containing solution is the content of the fluorescent dye in the fluorescent toner. As for it, it is preferable to adjust so that it may become 0.5-5 weight part with respect to 100 weight part of binder resin. When the content of the fluorescent dye is less than 0.5 parts by weight, it may be impossible to impart a fluorescent effect to the toner. On the other hand, when the content of the fluorescent dye is more than 5 parts by weight, the toner may cause uneven fluorescence.

(solvent)
The solvent for the fluorescent dye-containing solution (also referred to simply as a solvent in the present invention) is a solvent that dissolves the fluorescent dye 13 and promotes the fusion of the resin fine particles. There is no particular limitation as long as it has an action of plasticizing without being dissolved.

  In addition, since the solvent needs to be removed after spraying the fluorescent dye-containing solution in the fluorescent dye-containing solution spraying step S4c of the fluorescent toner particle preparation step S4 described later, the solvent is easily evaporated (boiling point is 30 ° C. or higher, 100 ° C. The following are preferable:

  Examples of the solvent include methanol, ethanol, propanol and the like, and ethanol is preferable. As a result, the wettability of the resin fine particles to the toner base particles 11 can be improved, and the resin fine particles and the fluorescent dye 13 are adhered to the entire surface or most of the toner base particles 11 and further deformed and formed into a film. Becomes easier. In addition, since a polar solvent has a high vapor pressure, the drying time when removing the solvent can be further shortened, and aggregation of the toner base particles 11 can be suppressed.

  The viscosity of the solvent is preferably 5 cP or less. The viscosity is measured at 25 ° C., and can be measured by, for example, a cone plate type rotary viscometer. Particularly preferable solutions having a viscosity of 5 cP or less include alcohols such as methanol, ethanol and propanol, acetonitrile and the like. Since these solvents have low viscosity and are easy to evaporate, they can be sprayed finely and uniformly without coarsening the spray droplet diameter of the fluorescent dye-containing solution sprayed from the spray means 203 described later. . As a result, in the film forming step S4d described later, the surfaces of the toner base particles 11 and the resin fine particles can be uniformly wetted and become familiar.

(4) Fluorescent toner particle preparation step S4
In the fluorescent toner particle preparation step S4, the surface of the toner base particle 11 prepared in the toner base particle preparation step S1 was adjusted in the resin fine particle preparation step S2 and the fluorescent dye-containing solution preparation step S3 using a toner manufacturing apparatus. A fluorescent dye-containing resin film 12 is formed using resin fine particles and a fluorescent dye-containing solution. As shown in FIG. 1, the fluorescent toner particle preparation step S4 includes a temperature adjustment step S4a, a resin fine particle adhesion step S4b, a fluorescent dye-containing solution spraying step S4c, a film forming step S4d, a recovery step S4e, and a drying step. S4f.

  In the present invention, in the fluorescent dye-containing solution spraying step S4c, the fluorescent dye-containing solution containing the fluorescent dye and the solvent is directed to the composite particles while circulating the composite particles in which the resin fine particles adhere to the surface of the toner base particles in an air stream. By spraying, wet composite particles in which the resin fine particles and the fluorescent dye-containing solution are adhered to the surface of the toner base particles are formed.

  In the film forming step S4d, the solvent is removed by circulating the wet composite particles in an air stream, and the resin fine particles and the fluorescent dye are formed into a film on the surface of the toner base particles.

  Further, when the resin fine particles and the fluorescent dye are formed on the surface of the toner base particles, aggregation of the wet composite particles can be suppressed and the production efficiency of the fluorescent toner can be improved. A film forming step comprising: circulating means for circulating composite particles or wet composite particles in an air stream; and spraying means for spraying a fluorescent dye-containing solution containing a fluorescent dye on the composite particles or wet composite particles circulating in the air stream; It is preferable to carry out the process repeatedly and continuously using a toner production apparatus provided with a rotating stirring means for applying an impact force to the composite particles circulating in the air stream or the wet composite particles. First, the toner manufacturing apparatus used in the fluorescent toner particle preparation step S4 will be described.

(Toner production equipment)
2 and 3
FIG. 2 is a schematic cross-sectional 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 flow path (circulation means))
In the present invention, in the powder flow path, composite particles in which resin fine particles adhere to the surface of the toner base particles, or wet composite particles in which resin fine particles and a fluorescent dye-containing solution adhere to the toner base particle surface are circulated in an air stream. It is preferable.

  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, gas and the like 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 preferably 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 the 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)
In the present invention, it is preferable to apply an impact force to the composite particles or wet composite particles circulating in the airflow by the 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 rotation shaft member 218 has an axis that coincides with the axis 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. 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)
In this invention, it is preferable to spray the fluorescent dye containing solution containing a fluorescent dye with respect to the composite particle or wet composite particle which circulates in an airflow by the 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 means 203 is a powder storage unit that stores a liquid (fluorescent dye-containing solution containing a fluorescent dye), a carrier gas supply unit that supplies a carrier gas, and a mixture obtained by mixing the liquid and the carrier gas. A two-fluid nozzle that sprays toward the toner base particles existing in the path 202 and 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. In addition, when the fluorescent dye-containing solution is sprayed continuously or discontinuously, the aggregation of wet composite particles can be further suppressed as compared with the case where the fluorescent dye-containing solution is put into the spraying means at once, and the fluorescent toner The production efficiency can be further improved.

(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 fluorescent dye-containing solution spraying step S4c and the film forming step S4d, variations in temperature applied to the toner base particles, resin fine particles and liquid can be reduced, and a stable fluid state of the toner base particles and resin fine particles can be maintained. .

  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)
FIG.
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 fluorescent dye-containing liquid-liquid 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) Fluorescent dye-containing solution spraying step S4c
In the fluorescent dye-containing solution spraying step S4c, the fluorescent dye-containing solution containing the fluorescent dye and the solvent is sprayed toward the composite particles while circulating the composite particles having the resin fine particles attached to the surface of the toner base particles in an air stream. As a result, wet composite particles in which the resin fine particles and the fluorescent dye-containing solution are adhered are formed on the surface of the toner base particles.

  Specifically, in the fluorescent dye-containing solution spraying step S4c, the fluorescent dye is dissolved in a liquid having an effect of plasticizing and assisting adhesion without dissolving the particles in the toner base particles and resin fine particles in a fluid state. A thing is sprayed by carrier gas from the above-mentioned spraying means 203.

  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. Further, when the carrier gas contains compressed air, the fluorescent toner can be manufactured more safely.

  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 solvent is removed by circulating the wet composite particles in an air stream, and the resin fine particles and the fluorescent dye are formed into a film on the surface of the toner base particles.

  Specifically, in the film forming step S4d, the rotation of the rotating stirring means 204 is continued at a predetermined temperature until the resin fine particles are softened and formed into a film, and the toner base particles and the resin fine particles are caused to flow. Cover with resin layer.

(4-5) Recovery step S4e
In the collecting step S4e, the liquid spray from the spraying means and the rotation of the rotary stirring means 204 are stopped, and the fluorescent dye-containing resin layer-coated toner is discharged from the powder collecting 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.

(4-6) Drying step S4f
In the drying step, the solvent is completely evaporated by applying hot air to the collected toner. Thereby, the toner shown in FIG. 5 can be obtained.

  As shown in FIG. 5, the fluorescent dye 13 is uniformly and finely dispersed on the surface of the toner. For this reason, a fluorescent toner having high transparency and excellent luminous efficiency can be obtained.

  As described above, according to the toner manufacturing method 1 according to the present embodiment, a toner having excellent saturation and lightness of a fixed image can be obtained by a synergistic effect between the spraying of the finer fluorescent dye-containing solution and the collision energy. Can be manufactured.

(5) External addition process S5
In order to improve functions such as powder flowability, inorganic fine particles (external additive) having a number average particle diameter of 7 nm to 50 nm are added (externally added) to the toner.

  As the external additive, those commonly used in this field can be used, and examples thereof include silica fine powder, titanium oxide fine powder, and alumina fine powder. These inorganic fine powders are for the purpose of hydrophobization, chargeability control, etc., silicone varnish, various modified silicone varnishes, silicone oil, various modified silicone oils, silane coupling agents, silane coupling agents having functional groups, and other It is preferably treated with an organosilicon compound or the like, and one kind can be used alone, or two or more kinds can be used in combination.

  The amount of the external additive is generally 1 to 5 parts by weight with respect to 100 parts by weight of the toner.

  The present invention will be further described below with reference to examples, but the present invention is not limited to these examples. In this example, a fluorescent toner was actually manufactured by the toner manufacturing method according to the present invention, and a comparative experiment was performed.

<Toner volume average particle diameter>
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 3, 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 diameter was determined, and the number average particle diameter was determined from the number particle size distribution of the sample particles.

<Volume average particle diameter of carrier>
A value measured under the condition of a dispersion pressure of 3.0 bar using a dry dispersion device RODOS (manufactured by SYMPATEC) in a laser diffraction particle size distribution measuring device HELOS (manufactured by SYMPATEC) was defined as the volume average particle size of the coated carrier.

<Number average particle diameter / Average primary particle diameter>
The primary particle size of the particles was measured with a scanning electron microscope, and the average value was taken as the average primary particle size.

<Glass transition temperature>
The glass transition temperature (Tg) was measured by using a differential scanning calorimeter (trade name: DSC220, manufactured by Seiko Denshi Kogyo Co., Ltd.) and in accordance with Japanese Industrial Standard (JIS) K7121-1987, 1 g of a sample was heated at a rate of 10 ° C. per minute. And the DSC curve was measured. 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>
Using a flow characteristic evaluation apparatus (trade name: Flow Tester CFT-100C, manufactured by Shimadzu Corporation), a load of 10 kgf / cm 2 (9.8 × 105 Pa) was applied to give 1 g of a sample (nozzle diameter 1 mm, length 1 mm). The sample was heated at a temperature elevation rate of 6 ° C. per minute, and the temperature at which half of the sample flowed out from the die was determined to obtain the flow softening temperature (Tf).

(Example 1)
(Toner mother particle production step S1)
As binder resin, polyester resin (trade name: Diacron, manufactured by Mitsubishi Rayon Co., Ltd., glass transition temperature 56 ° C., softening temperature 130 ° C.) 2 kg and paraffin wax (HNP-9 manufactured by Nippon Seiki Co., Ltd.) as a release agent 100 g was premixed using a Henschel mixer (trade name: FM20C, manufactured by Mitsui Mining Co., Ltd.) and then melt-kneaded by a twin-screw extrusion kneader (trade name: PCM65, manufactured by Ikekai Co., Ltd.). The maximum kneading temperature at this time was 152 ° C. in the thermometer provided in the twin-screw extrusion kneader.

  This melt-kneaded product is coarsely 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 size of 6.5 μm and a glass transition temperature of 55 ° C. were produced.

  The glass transition temperature (Tg) was measured using a differential scanning calorimeter (trade name: DSC220, manufactured by Seiko Denshi Kogyo Co., Ltd.) according to the Japanese Industrial Standard (JIS) K7121-1987, with 1 g of the sample heated at a rate of temperature increase per minute. The DSC curve was measured by heating at 10 ° 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).

(Resin fine particle preparation step S2)
In this example, styrene-butyl acrylate-acrylic acid copolymer fine particles (emulsion polymerization resin fine particles, Tg 60 ° C., manufactured by Soken Chemical Co., Ltd.) having a number average particle size of 0.3 μm were prepared as resin fine particles.

(Fluorescent dye-containing solution preparation step S3)
Coumarin (special grade reagent manufactured by Wako Pure Chemical Industries, Ltd., melting point 69 ° C.) was used as a fluorescent dye, and ethanol was used as a solvent. A solution containing a fluorescent dye was prepared by dissolving 20 g of coumarin in 100 g of ethanol.

(Fluorescent toner particle preparation step S4)
In this embodiment, as a toner manufacturing apparatus, a surface modification apparatus equipped with a two-fluid nozzle capable of spraying a fluorescent dye-containing solution (trade name: hybridization system NHS-1 type, manufactured by Nara Machinery Co., Ltd.) Was used.

  In this embodiment, the circulation flow path inside the toner manufacturing apparatus is set to 50 ° C., and 1 kg of toner base particles (volume average particle diameter 6.5 μm) and 100 g of resin fine particles (number average particle diameter 0.3 μm) are supplied to the toner manufacturing apparatus. And was allowed to stay at a rotational speed of 8000 rpm for 10 minutes to produce composite particles. When 1 g of composite particles were taken out from the toner manufacturing apparatus and observed with a scanning electron microscope (SEM), the surface of the toner base particles was uniformly coated with almost one layer of resin fine particles.

  Next, compressed air is fed to the two-fluid nozzle, and the fluorescent dye-containing solution is sprayed at a rate of 2 g / min for 50 minutes while circulating the composite resin particles in which the resin fine particles adhere to the surface of the toner base particles in an air stream. Thus, the surface of the composite resin particle is wetted and an impact force is applied to the wet composite particle to form a resin fine particle and a fluorescent dye on the surface of the toner base particle, followed by drying with hot air. A transparent fluorescent toner was obtained. The calculated fluorescent dye content in the transparent fluorescent toner is about 1.8 g per 1 kg of the toner.

  The obtained transparent fluorescent toner of Example 1 was observed with a scanning electron microscope (SEM). As a result, there was no unevenness due to the shape of the resin fine particles on the toner surface, and the toner mother particle surface was uniformly formed into a film.

  Next, 1 kg of the transparent fluorescent toner of Example 1 and 10 g of silica particles (R974 manufactured by Nippon Aerosil Co., Ltd., average primary particle size 12 nm) were externally added with a Henschel mixer (trade name: FM20C, manufactured by Mitsui Mining Co., Ltd.) The externally added transparent fluorescent toner of Example 1 was prepared and evaluated for luminous efficiency and transparency.

(Comparative Example 1)
As binder resin, polyester resin (trade name: Diacron, manufactured by Mitsubishi Rayon Co., Ltd., glass transition temperature 56 ° C., softening temperature 130 ° C.) 2 kg and as fluorescent dye, coumarin (special grade reagent manufactured by Wako Pure Chemical Industries, Ltd., melting point) 69 g) and paraffin wax (HNP-9 manufactured by Nippon Seiki Co., Ltd.) 100 g as a mold release agent were premixed using a Henschel mixer (trade name: FM20C, manufactured by Mitsui Mining Co., Ltd.) It was melt-kneaded by an extrusion kneader (trade name: PCM65, manufactured by Ikegai Co., Ltd.). The maximum kneading temperature at this time was 148 ° C. in the thermometer provided in the twin-screw extrusion kneader.

  This melt-kneaded product is coarsely 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.). The transparent fluorescent toner of Comparative Example 1 having a number average particle size of 7 μm and a glass transition temperature of 53 ° C. was produced. The calculated fluorescent dye content in the transparent fluorescent toner is about 1.8 g per 1 kg of the toner.

(Comparative Example 2)
A comparison of a number average particle diameter of 7 μm and a glass transition temperature of 53 ° C. in the same manner as in Comparative Example 1 except that a blue fluorescent pigment (FZ-SB manufactured by Sinloihi) was used as a fluorescent dye instead of coumarin. The transparent fluorescent toner of Example 2 was produced. The calculated fluorescent dye content in the transparent fluorescent toner is about 1.8 g per 1 kg of the toner.

<Evaluation>
Using the prepared externally added transparent fluorescent toner, luminous efficiency and transparency were evaluated by the following methods.
In addition, the transparent fluorescent toner of Comparative Example 1 was obtained by adding 10 g of silica particles (R974 manufactured by Nippon Aerosil Co., Ltd., average primary particle size of 12 nm) to Henschel mixer (trade name: FM20C, manufactured by Mitsui Mining Co., Ltd.) per 1 kg of the transparent fluorescent toner. The externally added transparent fluorescent toner was prepared by external addition in (1), and then the light emission efficiency and transparency were evaluated as follows.

<Method for evaluating luminous efficiency>
A three-dimensional spectrofluorometer (Shimadzu Corporation) is used as a measuring device for luminous efficiency, using a fixing sheet on which a solid image (transparent image) with a toner adhesion amount of 0.6 mg per square centimeter is formed on a transparent OHP sheet. RF-5300PC manufactured by the company was used, the excitation wavelength and the fluorescence wavelength were set to 360 nm and 500 nm, and the ratio of the excitation intensity to the fluorescence intensity was determined as the luminous efficiency.

<Transparency evaluation method>
A spectrophotometer (UV1240 manufactured by Shimadzu Corp.) was used as a transparency measuring device with a fixing sheet on which a solid image (transparent image) having a toner adhesion amount of 0.6 mg per square centimeter was formed on a transparent OHP sheet. ), The wavelength of incident light was set to 400 nm to 700 nm, and the transmittance of the incident light was determined as transparency.

  Table 1 shows the evaluation results of the luminous efficiency and transparency of the fluorescent toners of Examples and Comparative Examples.

実施例１の蛍光トナーは、発光効率と透明性ともに良好な結果が得られた。一方、比較例１の蛍光トナーは、発光効率が低く、明るい室内でブラックライトを用いた目視の簡易テストでも蛍光の確認が困難であった。
比較例１の蛍光トナーは、発光効率が低く、明るい室内でブラックライトを用いた目視の簡易テストでも蛍光の確認が困難であった。
比較例２の蛍光トナーは、透明性が低く、ブラックライトなしでもＯＨＰシート上の透明トナー画像が目に付いた。

With the fluorescent toner of Example 1, good results were obtained in both luminous efficiency and transparency. On the other hand, the fluorescent toner of Comparative Example 1 has low luminous efficiency, and it was difficult to confirm the fluorescence even in a simple visual test using a black light in a bright room.
The fluorescent toner of Comparative Example 1 had low luminous efficiency, and it was difficult to confirm the fluorescence even in a simple visual test using a black light in a bright room.
The fluorescent toner of Comparative Example 2 had low transparency, and a transparent toner image on the OHP sheet was noticeable even without black light.

  The present invention can be used in an electrophotographic image forming apparatus.

S1 Toner mother particle preparation step S2 Resin fine particle preparation step S3 Fluorescent dye-containing solution preparation step S4 Fluorescent toner particle preparation step S4a Temperature adjustment step S4b Resin fine particle adhesion step S4c Fluorescent dye-containing solution spraying step S4d Film forming step S4e Recovery step S4f Drying step S5 External process

A200 Cut surface line 201 Toner manufacturing apparatus 202 Powder flow path 203 Spraying means 204 (a) Rotating stirring means 206 Powder feeding section 207 Powder recovery section 208 Stirring section 208a Surface 208b on one side in the axial direction of the stirring section 208 Side surface 208c perpendicular to 208a Surface 209 on the other side in the axial direction of the agitating section 208 Powder flow section 210 Opening section 211 Opening section 212 Supply pipe 213 Electromagnetic valve 214 Arrow 215 Recovery tank 216 Recovery pipe 217 Electromagnetic valve 218 Rotating shaft member 219 Rotary plate 220 Stirrer blade 221 Through hole 222 Gas discharge part φ Spreading angle θ Angle formed by the direction of spraying the fluorescent dye-containing solution and the direction of arrow X

DESCRIPTION OF SYMBOLS 10 Fluorescent toner 11 Toner mother particle 12 Fluorescent dye containing resin film 13 Fluorescent dye

Claims (7)

By spraying a fluorescent dye-containing solution containing a fluorescent dye and a solvent toward the composite particles while circulating the composite particles having resin fine particles attached to the surface of the toner base particles in an air stream, A fluorescent dye-containing solution spraying step for forming wet composite particles to which the resin fine particles and the fluorescent dye-containing solution are attached;
A fluorescent toner comprising: a film forming step of removing the solvent by circulating the wet composite particles in the air stream to form the resin fine particles and the fluorescent dye on the surface of the toner base particles; Manufacturing method.   The fluorescent dye-containing solution spraying step and the film forming step include a circulation means for circulating the composite particles or the wet composite particles in the air stream, and the composite particles or the wet composite particles circulating in the air stream. Continuously and repeatedly using a toner producing apparatus comprising spraying means for spraying the fluorescent dye-containing solution and rotating stirring means for applying impact force to the composite particles or the wet composite particles circulating in the air stream. The manufacturing method of the fluorescent toner of Claim 1 implemented.   The method for producing a fluorescent toner according to claim 1, wherein the solvent contains ethanol, and the fluorescent dye contains any one of coumarin and a coumarin derivative.   4. The toner according to claim 1, wherein the toner base particles have a volume average particle diameter of 4 μm or more and 8 μm or less, and the resin fine particles have a number average particle diameter of 0.2 μm or more and 0.5 μm or less. The manufacturing method of the fluorescent toner of description.   The method for producing a fluorescent toner according to claim 1, wherein the air flow includes compressed air.   The method for producing a fluorescent toner according to claim 1, wherein the fluorescent dye-containing solution is sprayed continuously or discontinuously.   A fluorescent toner obtained by the production method according to claim 1.

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