JP2017102413A - Black fluorescent toner, toner storage unit, and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a black fluorescent toner that can form a print image with security simply by using only an image forming step with a black toner without using a transparent fluorescent toner.SOLUTION: There is provided a toner that contains at least a binder resin and colorant, wherein the colorant contains carbon black and fluorescent agent.SELECTED DRAWING: None

Description

  The present invention relates to a black fluorescent toner, a toner containing unit using the toner, and an image forming apparatus.

  In recent years, a method for forming an image with an electrophotographic image forming apparatus using an electrophotographic toner to which a fluorescent pigment having a fluorescent wavelength in the ultraviolet region is added in order to give security to an image printed matter is known. .

  In general, fluorescent toners for preventing impersonation use highly transparent toners. As a method for producing fluorescent toners with excellent luminous efficiency, a fluorescent dye-containing solvent containing a fluorescent dye and a solvent is used as a toner base particle. A toner manufacturing method having a film forming step of forming a fluorescent dye film by spraying resin fine particles adhering to the surface and the toner base surface and then removing the solvent is disclosed (for example, see Patent Document 1). ).

In addition, on the printed image of the black toner, the image of the transparent fluorescent toner is printed at a position shifted from the printing position of the black toner, and a print image characterized by the printed image of the transparent fluorescent toner is formed. A method of imparting sex is disclosed (for example, see Patent Document 2).
However, there is no known black fluorescent toner that can easily form a print image with added security by using only a black toner image forming process without using a transparent fluorescent toner.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a black fluorescent toner that can easily form a print image with a black toner to which security is imparted.

Means for solving the problems are as follows. That is,
The toner of the present invention is a toner containing at least a binder resin and a colorant, wherein the colorant contains carbon black and a fluorescent agent.

  According to the present invention, it is possible to provide a black fluorescent toner that can easily form a print image with a black toner imparted with security.

FIG. 1 is a cross-sectional view of a toner according to an embodiment of the present invention, to which a fluorescent agent is externally added. FIG. 2 is a cross-sectional view of a toner according to an embodiment of the present invention, in which a fluorescent agent is contained in a shell layer of a core-shell type toner. FIG. 3 is a cross-sectional view of a toner according to an embodiment of the present invention, in which a fluorescent material is contained in a toner base. FIG. 4 is a schematic configuration diagram showing an example of the image forming apparatus of the present invention.

(toner)
The toner of the present invention contains at least a binder resin and a colorant.
The colorant contains carbon black and a fluorescent agent.
The electrophotographic toner (also referred to as “toner”) according to the present invention contains at least a binder resin and a colorant, and further contains a release agent and other components as necessary. The toner of the present invention is a black fluorescent toner (also referred to as a toner or a black fluorescent toner in the present invention).

<Colorant>
The colorant contains carbon black and a fluorescent agent.
<< carbon black >>
Examples of the carbon black include carbon blacks (CI pigment black 7) such as furnace black, lamp black, acetylene black, and channel black. In addition to the carbon black, a black pigment made of metal such as copper, iron (CI pigment black 11), titanium oxide, or an organic pigment such as aniline black (CI pigment black 1) is used in combination. May be.

<< Fluorescent agent >>
The fluorescent agent is a pigment or dye that emits fluorescence by excitation light in the ultraviolet and visible regions, and is not particularly limited and can be appropriately selected according to the purpose. It may be a phosphorescent phosphor that emits light.
Specific examples of the fluorescent agent include inorganic fluorescent pigments such as sulfides, silicates and phosphorus of alkaline earth metals such as calcium tungstate, magnesium arsenate, calcium arsenate, barium silicate, calcium phosphate, and calcium zinc phosphate. Organic fluorescent pigments; organic fluorescent dyes such as 4,4′-bis (4-phenyl-1,2,3-triazol-2-yl) stilbene-2 ′, 2′-disulfonic acid Sodium, 3-phenyl-7- (4-methyl-5-phenyl-1,2,3-triazol-2-yl) coumarin, 3-phenyl-7- (2H-naphtho [1,2-d] -triazole -2-yl) coumarin, 1- (4-acidsulfonylphenyl) -3- (4-chlorophenyl) -2-pyrazoline and other coumarin derivatives, naphthalimi Derivatives, stilbene derivatives, benzothiazole derivatives, benzimidazole derivatives, benzoxazole derivatives, benzidine derivatives. Among these, coumarin derivatives and naphthalimide derivatives are preferable, and coumarin derivatives are more preferable.

Fluorescent agents that can be used in the present invention include Solvent Yellow 44, Solvent Orange 5, 55, Solvent Red 49, 149, 150, Solvent Blue 5, Solvent Green 7, Acid Yellow 3, 7, Acid Red 52, 77, 87, 92, Acid Blue 9, Basic Yellow 1, 40, Basic Red 1, 13, Basic Violet 7, 10, 110, Basic Orange 14, 22, Basic Blue 7, Basic Green 1, Bat Red 41, Disperse Yellow 82 121, 124, 184: 1, 186, 199, 216, disperse orange 11, disperse thread 58, 239, 240, 345, 362, 364, disperse blue 7, 56, 183, 155, 354, 365, Hispers Violet 26, 27, 28, 35, 38, 46, 48, 57, 63, 77, 97, Direct Yellow 85, Direct Orange 8, 9, Direct Blue 22, Direct Grain 6, Fluorescent Brightening Agent 54, There are a fluorescent brightening agent 135, a fluorescent brightening agent 162, a fluorescent brightening agent 260, and the like.
In addition to these fluorescent agents, in the range of black that can be used as a black toner, ordinary acid dyes, reactive dyes, direct dyes, disperse dyes, cationic dyes, organic pigments, inorganic pigments, and other colorants are used in combination. Also good.

  The fluorescent agent is a fluorescent agent that emits fluorescence by excitation light in the ultraviolet light region and the visible light region, and is particularly preferably a fluorescent agent having a peak wavelength of a fluorescence spectrum in a wavelength region of 450 nm to 780 nm or less. In this case, the fluorescence emitted by the excitation light in the ultraviolet light region and the visible light region becomes a wavelength region from yellow to red, and the visibility of the fluorescence in the printed image by the black toner is high.

  When the fluorescent agent has a peak wavelength in the wavelength range of 380 nm to less than 450 nm, the fluorescence emitted by the excitation light in the ultraviolet light region and the visible light region has a blue color. Inferior.

  It is preferable that the peak wavelength of the absorption spectrum does not include the visible light region in the wavelength region so that the fluorescent agent in the present invention does not affect the color or the like.

  As the fluorescent agent in the present invention, the peak wavelength of the fluorescence spectrum is in the wavelength region of 450 nm to 780 nm, such as Yellow 1057-YD (manufactured by BASF Japan Ltd.), Cartax CXDPp (manufactured by Clariant Co., Ltd.), and the peak of the absorption spectrum The wavelength is preferably not in the visible light region. In particular, Yellow 1057-YD (manufactured by BASF Japan Ltd.) is excellent in light resistance, and long-term security can be expected.

  When the fluorescent agent is contained in the toner base, the content of the fluorescent agent is preferably 4 parts by mass to 8 parts by mass with respect to 100 parts by mass of the toner. When the content of the fluorescent agent is 4 parts by mass or more, a sufficient fluorescent effect can be imparted to the toner. If the content of the fluorescent agent is 8 parts by mass or less, it is possible to effectively prevent problems such as uneven fluorescence and a reduction in black color of the toner.

  When the fluorescent agent is present in the vicinity of the toner surface, the content of the fluorescent agent is preferably 1 part by mass to 4 parts by mass with respect to 100 parts by mass of the toner. If the content of the fluorescent agent is 1 part by mass or more, a sufficient fluorescent effect can be imparted to the toner. If the content of the fluorescent agent is 4 parts by mass or less, it is possible to effectively prevent problems such as uneven fluorescence and a reduction in black color of the toner.

<Binder resin>
The binder resin is not particularly limited, and a conventionally known material can be appropriately used depending on the purpose. For example, polystyrene, chloropolystyrene, poly α-methylstyrene, styrene / chlorostyrene copolymer, styrene / Propylene copolymer, styrene / butadiene copolymer, styrene / vinyl chloride copolymer, styrene / vinyl acetate copolymer, styrene / maleic acid copolymer, styrene / acrylic acid ester copolymer (styrene / acrylic acid) Methyl copolymer, styrene / ethyl acrylate copolymer, styrene / butyl acrylate copolymer, styrene / octyl acrylate copolymer, styrene / phenyl acrylate copolymer, etc.), styrene / methacrylic acid ester copolymer Copolymer (styrene / methyl methacrylate copolymer, styrene / methacryl Styrene such as ethyl copolymer, styrene / butyl methacrylate copolymer, styrene / phenyl methacrylate copolymer), styrene / methyl α-chloroacrylate copolymer, styrene / acrylonitrile / acrylate ester copolymer, etc. Resin (homopolymer or copolymer containing styrene or styrene-substituted product), vinyl chloride resin, styrene / vinyl acetate copolymer, rosin-modified maleic acid resin, phenol resin, epoxy resin, polyethylene resin, polypropylene resin, ionomer Examples thereof include resins, polyurethane resins, silicone resins, ketone resins, ethylene / ethyl acrylate copolymers, petroleum resins such as xylene resins and polyvinyl butyral resins, and hydrogenated petroleum resins. These may be used individually by 1 type and may use 2 or more types together.
There is no restriction | limiting in particular as a manufacturing method of these resin, Any of block polymerization, solution polymerization, emulsion polymerization, and suspension polymerization can be utilized.

<Other toner components>
Examples of other components include a release agent, a charge control agent, and an external additive.

<< Releasing agent >>
There is no restriction | limiting in particular as a mold release agent, It can select suitably from well-known things. For example, low molecular weight polyolefin waxes such as low molecular weight polyethylene and low molecular weight polypropylene; synthetic hydrocarbon waxes such as Fischer-Tropsch wax; natural waxes such as beeswax, carnauba wax, candelilla wax, rice wax and montan wax; Petroleum waxes such as paraffin wax and microcrystalline wax; higher fatty acids such as stearic acid, palmitic acid and myristic acid, metal salts and amides thereof; synthetic ester waxes; and various modified waxes thereof. These may be used individually by 1 type and may use 2 or more types together.

<< Charge Control Agent >>
The charge control agent is not particularly limited and may be appropriately selected depending on the intended purpose. For example, modified products such as nigrosine and fatty acid metal salts, onium salts such as phosphonium salts, lake pigments thereof, and triphenyl Methane dyes and their lake pigments, metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; diorganotin borates such as dibutyltin borate, dioctyltin borate, dicyclohexyltin borate, organic Examples thereof include metal complexes, chelate compounds, monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, aromatic dicarboxylic acid metal complexes, quaternary ammonium salts, and salicylic acid metal compounds. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- or polycarboxylic acids and metal salts thereof, anhydrides, esters, phenol derivatives such as bisphenol, and the like. These may be used individually by 1 type and may use 2 or more types together.

<< External additive >>
The external additive is not particularly limited and may be appropriately selected depending on the intended purpose. For example, silica, Teflon (registered trademark) resin powder, polyvinylidene fluoride powder, cerium oxide powder, silicon carbide powder, titanium Polishing agent such as strontium acid powder, fluidity imparting agent such as titanium oxide powder, aluminum oxide powder, anti-aggregation agent, resin powder, or zinc oxide powder, conductivity imparting agent such as antimony oxide powder, tin oxide powder, or Reverse polarity white fine particles and black fine particle developability improvers can be used. These can be used alone or in combination, and can be selected so as to be resistant to development stress such as idling.

<About toner structure>
Examples of the toner structure include the modes shown in the cross-sectional views of FIGS. 1 to 3. In the figure, reference numeral 1 denotes a black fluorescent toner, reference numeral 2 denotes a fluorescent agent, reference numeral 3 denotes an external additive, and reference numeral 4 denotes a toner base.
In the toner of FIG. 1, a fluorescent material 2 is externally added to a toner base 4 together with other external additives 3. In the toner of FIG. 2, the fluorescent agent 2 is contained in the shell layer of the core-shell type toner, and the fluorescent agent 2 is present in the vicinity of the toner surface. In the toner of FIG. 3, the fluorescent material 2 is contained in the toner base 4, and the fluorescent agent 2 is inherent in the toner base 4.
In the present invention, the fluorescent agent 2 may be externally added as shown in FIG. 1 to the core-shell type toner in which the fluorescent agent 2 is contained in the shell layer as shown in FIG. Further, as shown in FIG. 3, the fluorescent agent 2 may be externally added as shown in FIG. 1 to the toner containing the fluorescent agent 2 in the toner.
In the present invention, an embodiment in which a fluorescent agent is present in the vicinity of the toner surface is more preferable. In the present invention, the presence of the fluorescent agent in the vicinity of the toner surface means, for example, that the fluorescent agent is attached to the outer surface of the toner as shown in FIG. And when it is contained in the layer (when the fluorescent agent is present in the region about 15% inside the particle diameter from the toner surface). Even when the fluorescent agent is added simultaneously with the core material of the core-shell type toner, the fluorescent agent is present on the surface of the core layer or in the vicinity of the surface of the core layer, and when it can be considered that the fluorescent material is present in substantially the same region as the shell layer, The fluorescent agent may be considered to be present in the shell layer. In this case, the substantially same region as the shell layer refers to a region approximately 15% inside the particle diameter from the toner surface.

<Toner production method>
There is no restriction | limiting in particular as a manufacturing method of the toner of this invention, According to the objective, it can select suitably, For example, a grinding method, a polymerization method, etc. are mentioned.
The pulverization method includes at least a melt-kneading step and a pulverization step, and further includes other steps such as a cooling step and a classification step as necessary. That is, the toner material is dry-mixed, melt-kneaded in a kneader, and pulverized to obtain a pulverized toner.
There is no restriction | limiting in particular as said polymerization method, According to the objective from conventionally well-known, it can select suitably, For example, a suspension polymerization method, a solution suspension method, an emulsion aggregation method, an ester extension method etc. are mentioned.

<< Crushing method >>
The melt kneading step is a step of melt kneading a mixture obtained by mixing the above-described toner materials. As the melt kneader used in the melt kneading step, for example, a uniaxial continuous kneader, a biaxial continuous kneader, or a batch kneader using a roll mill can be used. Specifically, KTK type twin screw extruder manufactured by Kobe Steel, TEM type extruder manufactured by Toshiba Machine Co., Ltd., twin screw extruder manufactured by Casey Kay Co., Ltd., PCM type twin screw extruder manufactured by Ikekai Iron Works Co., Ltd., manufactured by Busus A kneader or the like is preferably used. The melt-kneading is preferably performed under appropriate conditions that do not cause the molecular chain of the binder resin to be broken. Specifically, the melt-kneading temperature is determined with reference to the softening point of the binder resin, and the higher the temperature, the more severe the cutting, and the lower the temperature, the less the dispersion.

The pulverization step is a step of pulverizing the kneaded product obtained in the melt-kneading step. In this pulverization, it is preferable that the kneaded material is first coarsely pulverized and then finely pulverized. At this time, a method of pulverizing by colliding with a collision plate in a jet stream, pulverizing particles by colliding with each other in a jet stream, or pulverizing with a narrow gap between a mechanically rotating rotor and a stator is preferably used.
The classification step is a step of classifying the pulverized product obtained in the pulverization step, and the toner can be adjusted to particles having a predetermined particle diameter. Classification can be performed, for example, by removing fine particle portions by a cyclone, a decanter, centrifugation, or the like.
After the pulverization and classification are completed, the pulverized product is classified in an air stream with a centrifugal force or the like to produce a toner having a predetermined particle size.

In order to improve the fluidity, storage stability, developability, and transferability of the toner, an external additive is prepared by adding an external additive such as hydrophobic silica fine powder to the toner (toner base particle) produced as described above. A mixing step may be further included.
In the toner of the present invention, as a method for allowing the fluorescent agent to be present in the vicinity of the toner surface, it is preferable to mix the fluorescent agent in this external additive mixing step.

As another method for causing the fluorescent agent to be present in the vicinity of the toner surface, there is a method in which the toner base particles and the fluorescent agent are mixed in advance, and then mechanical energy is applied to drive the fluorescent agent in the vicinity of the toner surface. Any mixing method may be used such as a ball mill, a V blender, a Henschel mixer and the like. As a method of giving mechanical energy, a method of applying an impact to the mixture by blades rotating at high speed, a method of injecting the mixture into a high-speed air stream to accelerate particles, and causing particles or mixed particles to collide with an appropriate collision plate, etc. Thus, the fluorescent agent is adhered and fixed on the surface of the toner base particles. Specific examples of the apparatus include an ong mill (Hosokawa Micron Co., Ltd.) and an I-type mill (Nippon New-Machitsuku Kogyo Co., Ltd.), a pulverization air pressure lower than that in the case of normal pulverization, and a hybridize system (Nara). Machine mill) and automatic mortar.
Thereafter, inorganic fine particles such as silica fine particles and titanium oxide fine particles may be externally added to obtain a toner. The external addition of the inorganic fine particles is performed by a known method using a mixer or the like. As an external additive to the base coloring particles, it is preferable to add 0.5 to 5 parts by mass of inorganic fine particles to 100 parts by mass of the toner.

The mixing device that can be used in the external additive mixing step is not particularly limited as long as the powder can be mixed, and a known device can be used. For example, a V-type mixer, a rocking mixer, a Ladige mixer, a now-known device can be used. Turmixer, Henschel mixer, etc. These mixing devices are preferably those equipped with a jacket or the like and capable of adjusting the internal temperature.
In order to change the load history applied to the external additive, for example, the external additive may be added in the middle of the mixing or gradually, and the rotation speed, rolling speed, time, temperature, etc. of the mixer may be changed as appropriate. You may let them. Further, a strong load may be applied first, and then a relatively weak load may be applied, or vice versa.

  In addition, after performing the said external additive mixing process, you may pass a 250 mesh or more sieve, and may remove a coarse particle and an aggregated particle.

<< Dissolution suspension method >>
In the dissolution suspension method, for example, an oil phase composition in which a toner composition containing at least a binder resin or a resin precursor, a colorant, and a release agent is dissolved or dispersed in an organic solvent is used. In this method, toner base particles are produced by dispersing or emulsifying in a medium.
The toner of the present invention preferably contains a fluorescent agent in the oil phase composition as a method of incorporating the fluorescent agent in the toner.

  The organic solvent used for dissolving or dispersing the toner composition is preferably volatile with a boiling point of less than 100 ° C. from the viewpoint of easy removal of the solvent later.

  In the dissolution suspension method, when the oil phase composition is dispersed or emulsified in an aqueous medium, an emulsifier or a dispersant may be used as necessary.

<<< Dissolution suspension polymerization method >>>
In the dissolution suspension polymerization method, an oil phase including at least a binder resin, a reactive group-containing binder resin precursor (reactive group-containing prepolymer), a colorant, and a release agent in the dissolution suspension method. It is preferable to obtain the toner base particles by dispersing or emulsifying the composition in an aqueous medium containing resin fine particles.
The electrophotographic toner of the present invention preferably contains a fluorescent agent in the oil phase composition as a method of incorporating the fluorescent agent in the toner.
As the reactive group-containing binder resin precursor, a reactive group-containing prepolymer having a functional group capable of reacting with an active hydrogen group is known, and the oil phase composition in the emulsified and granulated base particles. A method of reacting the active hydrogen group-containing compound contained in the medium and / or the aqueous medium with the prepolymer is preferred.

The resin fine particles can be formed using a known polymerization method, but is preferably obtained as an aqueous dispersion of resin fine particles.
The volume average particle diameter of the resin fine particles is preferably 10 nm to 300 nm, and more preferably 30 nm to 120 nm. When the volume average particle size of the resin fine particles is 10 nm or more or 300 nm or less, it is possible to effectively prevent the deterioration of the particle size distribution of the toner.

  The solid content concentration of the oil phase composition is preferably 40% by mass to 80% by mass. If the solid content concentration is too high, dissolution or dispersion may be difficult, and the viscosity may be high and difficult to handle. If the solid content concentration is too low, the productivity of the toner may be reduced.

  The toner composition other than the binder resin such as the colorant and the release agent, and the masterbatch thereof are individually dissolved or dispersed in an organic solvent, and then mixed with the binder resin solution or dispersion. May be.

  As the aqueous medium, water alone may be used, but a solvent miscible with water may be used in combination. Examples of solvents miscible with water include alcohols (methanol, isopropanol, ethylene glycol, etc.), dimethylformamide, tetrahydrofuran, cellosolves (methyl cellosolve, etc.), lower ketones (acetone, methyl ethyl ketone, etc.), and the like.

  The dispersion or emulsification method in the aqueous medium is not particularly limited, and known equipment such as a low-speed shearing type, a high-speed shearing type, a friction type, a high-pressure jet type, and an ultrasonic wave can be applied. Among these, the high-speed shearing method is preferable from the viewpoint of reducing the particle size of the particles. When a high-speed shearing disperser is used, the rotational speed is not particularly limited, but is usually 1,000 rpm to 30,000 rpm, preferably 5,000 to 20,000 rpm. As temperature at the time of dispersion | distribution, it is 0 to 150 degreeC (under pressure) normally, and 20 to 80 degreeC is preferable.

  The method for removing the organic solvent from the obtained emulsified dispersion is not particularly limited and may be appropriately selected depending on the purpose. A method in which the temperature is raised and the organic solvent in the droplets is completely removed by evaporation can be employed.

  As a method of washing and drying the toner base particles dispersed in the aqueous medium, a known technique is used. That is, after solid-liquid separation with a centrifuge, a filter press, etc., the obtained toner cake is redispersed in ion exchange water at about room temperature to about 40 ° C., and after adjusting the pH with acid or alkali as necessary, After removing the impurities and surfactants by repeating the process of solid-liquid separation again and again, the toner powder is obtained by drying with an air dryer, circulating dryer, vacuum dryer, vibration fluid dryer, etc. . At this time, the fine particle component of the toner may be removed by centrifugation or the like, and a desired particle size distribution can be obtained using a known classifier after drying, if necessary.

The toner base particles may be mixed with particles such as the external additive and the charge control agent. At this time, by applying a mechanical impact force, it is possible to prevent the particles such as the external additive from being detached from the surface of the toner base particles.
The method for applying the mechanical impact force is not particularly limited and can be appropriately selected depending on the purpose. For example, a method for applying the impact force to the mixture using blades rotating at high speed, For example, a method may be used in which the mixture is charged and accelerated to cause the particles or particles to collide with an appropriate collision plate.
The apparatus used in the above method is not particularly limited and can be appropriately selected according to the purpose. For example, an ang mill (manufactured by Hosokawa Micron Co., Ltd.), an I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) is modified and pulverized air is used. Examples include an apparatus for reducing pressure, a hybridization system (manufactured by Nara Machinery Co., Ltd.), a kryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), and an automatic mortar.

(Toner storage unit)
The toner storage unit in the present invention refers to a unit in which toner is stored in a unit having a function of storing toner. Here, examples of the toner storage unit include a toner storage container, a developing device, and a process cartridge.
The toner container is a container that contains toner.
The developing device is a unit having a means for containing and developing toner.
The process cartridge is a cartridge in which at least an electrostatic latent image carrier (also referred to as an image carrier) and a developing unit are integrated, accommodates toner, and is detachable from the image forming apparatus. The process cartridge may further include at least one selected from a charging unit, an exposure unit, and a cleaning unit.
By forming the image by attaching the toner containing unit of the present invention to the image forming apparatus, it is possible to easily form a printed image with the black toner with added security. It can be performed.

(Image forming device)
The image forming apparatus of the present invention includes at least an electrostatic latent image carrier, an electrostatic latent image forming unit, and a developing unit, and further includes other units as necessary.
More preferably, the image forming apparatus of the present invention is an electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, and the electrostatic latent image carrier. The electrostatic latent image formed on the body is developed with toner to form a toner image, and a developing means including toner, and the toner image formed on the electrostatic latent image carrier are transferred to a recording medium Transfer means for transferring to the surface, and fixing means for fixing the toner image transferred to the surface of the recording medium.
The toner is used in the developing unit. Preferably, the toner image may be formed by using a developer containing the toner and further containing other components such as a carrier as necessary.

  Next, one aspect of the image forming apparatus of the present invention will be described with reference to FIG. A color image forming apparatus 100A shown in FIG. 4 includes a photosensitive drum 10 (hereinafter also referred to as “photosensitive member 10”) as the electrostatic latent image carrier, a charging roller 20 as the charging unit, and the An exposure apparatus 30 as an exposure means, a developing device 40 as the development means, an intermediate transfer member 50, a cleaning device 60 as the cleaning means having a cleaning blade, and a static elimination lamp 70 as the static elimination means. .

  The intermediate transfer member 50 is an endless belt, and is designed to be movable in the direction of an arrow by three rollers 51 that are arranged inside and stretched. Part of the three rollers 51 also functions as a transfer bias roller that can apply a predetermined transfer bias (primary transfer bias) to the intermediate transfer member 50. A cleaning device 90 having a cleaning blade is disposed in the vicinity of the intermediate transfer member 50. Also, in the vicinity of the intermediate transfer member 50, there is a transfer roller 80 as the transfer means capable of applying a transfer bias for transferring (secondary transfer) a developed image (toner image) onto a transfer sheet 95 as a recording medium. The intermediate transfer member 50 is disposed opposite to the intermediate transfer member 50. Around the intermediate transfer member 50, a corona charger 58 for applying a charge to the toner image on the intermediate transfer member 50 is arranged between the photosensitive member 10 and the intermediate transfer member 50 in the rotation direction of the intermediate transfer member 50. It is disposed between the contact portion and the contact portion between the intermediate transfer member 50 and the transfer paper 95.

  The developing device 40 includes a developing belt 41 as the developer carrying member, and a black (Bk) developing unit 45K, a yellow (Y) developing unit 45Y containing the black fluorescent toner of the present invention provided around the developing belt 41, It is composed of a magenta (M) developing unit 45M and a cyan (C) developing unit 45C. The black developing unit 45K containing the black fluorescent toner of the present invention includes a developer accommodating portion 42K, a developer supply roller 43K, and a developing roller 44K. The black fluorescent toner of the present invention is accommodated in the developer accommodating portion 42K. The yellow developing unit 45Y includes a developer container 42Y, a developer supply roller 43Y, and a developing roller 44Y. The magenta developing unit 45M includes a developer container 42M, a developer supply roller 43M, and a developing roller 44M. The cyan developing unit 45C includes a developer container 42C, a developer supply roller 43C, and a developing roller 44C. Further, the developing belt 41 is an endless belt, is rotatably stretched around a plurality of belt rollers, and a part thereof is in contact with the electrostatic latent image carrier 10.

  Examples of the present invention will be described below, but the present invention is not limited to the following examples. “%” Represents “% by mass”, and “part” represents “part by mass” unless otherwise specified.

(Production example of black fluorescent toner 1)
Polyester resin (Mw7,300, Mn2,400, acid value 12 mgKOH / g) 94 parts Monoester wax 1 (mp70.5 ° C) 6 parts Carbon black (manufactured by Mitsubishi Chemical Corporation) 8 parts Yellow 1057-YD (BASF Japan stock) 5.7 parts The above toner raw materials were premixed using a Henschel mixer (manufactured by Nihon Coke Kogyo Co., Ltd., FM20B), and then 100 ° C. to uniaxial kneader (Buss, Conida kneader). It was melted and kneaded at a temperature of 130 ° C. The obtained kneaded product was cooled to room temperature and then coarsely pulverized to 200 μm to 300 μm using a funnel plex. Next, the mixture was finely pulverized using a counter jet mill (100 AFG manufactured by Hosokawa Micron Co., Ltd.) so that the weight average particle size was 6.2 ± 0.3 μm, and an air classifier ( EJ-LABO (Matsubo Co., Ltd.) adjusts the louver opening appropriately so that the weight average particle size is 7.0 ± 0.2 μm and the weight average particle number / number average particle size ratio is 1.25 or less. Then, classification was performed to obtain toner base particles. Next, 1.5 parts by mass of silica fine particles (manufactured by Clariant Co., Ltd., HDK-2000) was mixed with stirring with a Henschel mixer with respect to 100 parts of the toner base particles, whereby a black fluorescent toner 1 was produced.

(Production example of black fluorescent toner 2)
Polyester resin (Mw7,300, Mn2,400, acid value 12 mgKOH / g) 94 parts Monoester wax 1 (mp70.5 ° C) 6 parts Carbon black (Mitsubishi Chemical Corporation) 8 parts Cartax CXDPp (Clariant Corporation) 5.7 parts Black fluorescent toner 2 was produced in the same manner as black fluorescent toner 1 except that the above toner raw materials were used.

(Example of production of black fluorescent toner 3)
Polyester resin (Mw7,300, Mn2,400, acid value 12 mgKOH / g) 94 parts Monoester wax 1 (mp70.5 ° C) 6 parts Carbon black (Mitsubishi Chemical Corporation) 8 parts Cartax CXDPp (Clariant Corporation) 3.3 parts Black fluorescent toner 3 was produced in the same manner as black fluorescent toner 1 except that the above toner raw materials were used.

(Production example of black fluorescent toner 4)
Polyester resin (Mw7,300, Mn2,400, acid value 12 mgKOH / g) 94 parts Monoester wax 1 (mp70.5 ° C) 6 parts Carbon black (Mitsubishi Chemical Corporation) 8 parts Yellow fluorescent pigment (BASF Japan Ltd.) Lumogen Yellow S 0795) 5.7 parts A black fluorescent toner 4 was produced in the same manner as the black fluorescent toner 1 except that the above toner raw materials were used.

(Production example of black fluorescent toner 5)
Polyester resin (Mw 7,300, Mn 2,400, acid value 12 mg KOH / g) 94 parts Monoester wax 1 (mp 70.5 ° C.) 6 parts Carbon black (manufactured by Mitsubishi Chemical Corporation) 8 parts Blue fluorescent pigment (Sinrohi FZ -SB) 5.7 parts Black fluorescent toner 5 was produced in the same manner as black fluorescent toner 1 except that the above toner raw materials were used.

(Example of production of black fluorescent toner 6)
Polyester resin (Mw7,300, Mn2,400, acid value 12 mgKOH / g) 94 parts Monoester wax 1 (mp70.5 ° C) 6 parts Carbon black (Mitsubishi Chemical Corporation) 8 parts Red fluorescent pigment (Sinrohi FZ -6013) 5.7 parts Black fluorescent toner 6 was produced in the same manner as black fluorescent toner 1 except that the above toner raw materials were used.

(Production example of black fluorescent toner 7)
Polyester resin (Mw7,300, Mn2,400, acid value 12 mgKOH / g) 94 parts Monoester wax 1 (mp70.5 ° C.) 6 parts Carbon black (Mitsubishi Chemical Corporation) 8 parts Other than using the above toner raw materials Produced toner base particles in the same manner as black fluorescent toner 1. Next, 1.5 parts by mass of silica fine particles (manufactured by Clariant Co., Ltd., HDK-2000) and 1.1 parts of Yellow 1057-YD (manufactured by BASF Japan Ltd.) are agitated and mixed with a Henschel mixer with respect to 100 parts of the toner base particles. A black fluorescent toner 7 was produced.

(Example of production of black fluorescent toner 8)
<Manufacture of toner base particles>
-Synthesis of crystalline polyester resin-
1,5-alkanediol 2,300 g, fumaric acid 2,530 g, trimellitic anhydride 291 g, hydroquinone 4.9 g in a 5-liter four-necked flask equipped with a nitrogen inlet tube, dehydration tube, stirrer and thermocouple The mixture was reacted at 160 ° C. for 5 hours, heated to 200 ° C. and reacted for 1 hour, and further reacted at 8.3 kPa for 1 hour to obtain a crystalline polyester resin 1. DSC endothermic peak temperature was 120 ° C., Mn 1,500, Mw 9,000. The SP value was 10.8.
-Synthesis of non-crystalline polyester (low molecular polyester) resin-
A 5-liter four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer and a thermocouple, 229 parts of bisphenol A ethylene oxide side 2 mol adduct, 529 parts of bisphenol A propylene oxide 3 mol adduct, terephthalic acid 208 parts, 46 parts of adipic acid and 2 parts of dibutyltin oxide were added, reacted at 230 ° C. at normal pressure for 7 hours, further reacted at reduced pressure of 10 mmHg to 15 mmHg for 4 hours, and then 44 parts of trimellitic anhydride was added to the reaction vessel. The mixture was reacted at 180 ° C. and normal pressure for 2 hours to obtain [Non-crystalline polyester].
-Synthesis of polyester prepolymer-
In a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, 682 parts of bisphenol A ethylene oxide 2-mole adduct, 81 parts of bisphenol A propylene oxide 2-mole adduct, 283 parts of terephthalic acid, trimellitic anhydride 22 Part and 2 parts of dibutyltin oxide were added, reacted at 230 ° C. at normal pressure for 8 hours, and further reacted for 5 hours at a reduced pressure of 10 mmHg to 15 mmHg to obtain an [intermediate polyester]. [Intermediate polyester] had a number average molecular weight of 2,100, a weight average molecular weight of 9,500, Tg of 55 ° C., an acid value of 0.5, and a hydroxyl value of 51.
Next, 410 parts of [intermediate polyester], 89 parts of isophorone diisocyanate, and 500 parts of ethyl acetate are placed in a reaction vessel equipped with a cooling pipe, a stirrer and a nitrogen introduction pipe, and reacted at 100 ° C. for 5 hours. ] Was obtained. [Prepolymer] had a free isocyanate mass% of 1.53%.
-Synthesis of ketimine-
In a reaction vessel equipped with a stirrer and a thermometer, 170 parts of isophoronediamine and 75 parts of methyl ethyl ketone were charged and reacted at 50 ° C. for 5 hours to obtain [ketimine compound]. The amine value of [ketimine compound] was 418.
-Synthesis of master batch (MB)-
1200 parts of water, carbon black (manufactured by Printex 35 Dexa) [DBP oil absorption = 42 ml / 100 mg, pH = 9.5], 540 parts, polyester resin 1,200 parts are added, and mixed with a Henschel mixer (manufactured by Mitsui Mining). The mixture was kneaded at 150 ° C. for 30 minutes using two rolls, rolled and cooled, and pulverized with a pulverizer to obtain a [masterbatch].

-Creation of oil phase-
A container equipped with a stir bar and a thermometer was charged with 378 parts of [Non-crystalline polyester], 110 parts of Carnauba WAX, 22 parts of CCA (salicylic acid metal complex E-84: Orient Chemical Industry), and 947 parts of ethyl acetate. The temperature was raised to 0 ° C., kept at 80 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour. Next, 500 parts of [Master batch], 22.4 parts of Yellow 1057-YD (manufactured by BASF Japan Ltd.), and 500 parts of ethyl acetate were charged into the container and mixed for 1 hour to obtain a [raw material solution].
[Raw material solution] 1,324 parts were transferred to a container, and using a bead mill (Ultra Visco Mill, manufactured by Imex Co., Ltd.), a liquid feeding speed of 1 kg / hr, a disk peripheral speed of 6 m / sec, and a volume of 0.5 mm zirconia beads of 80 volumes. Dispersion of carbon black and WAX was performed under the conditions of% filling and 3 passes. Next, 1,042.3 parts of a 65% ethyl acetate solution of [amorphous polyester] was added, and one pass was performed with a bead mill under the above conditions to obtain [Pigment / WAX dispersion]. The solid content concentration of the [pigment / WAX dispersion] (130 ° C., 30 minutes) was 50%.
-Preparation of dispersion of crystalline polyester-
100 g of [Crystalline Polyester Resin] and 400 g of ethyl acetate were placed in a metal 2 L container, heated and dissolved at 75 ° C., and then rapidly cooled in an ice water bath at a rate of 27 ° C./min. To this, 500 ml of glass beads (3 mmφ) was added, and pulverized for 10 hours with a batch type sand mill (manufactured by Campehapio) to obtain [Crystalline Polyester Dispersion].
-Synthesis of organic fine particle emulsion-
In a reaction vessel equipped with a stir bar and a thermometer, 683 parts of water, 11 parts of sodium salt of ethylene oxide methacrylate adduct sulfate (Eleminol RS-30: manufactured by Sanyo Chemical Industries), 138 parts of styrene, 138 parts of methacrylic acid, When 1 part of ammonium persulfate was charged and stirred at 400 rpm for 15 minutes, a white emulsion was obtained. The system was heated to raise the system temperature to 75 ° C. and reacted for 5 hours. Further, 30 parts of a 1% ammonium persulfate aqueous solution was added, and the mixture was aged at 75 ° C. for 5 hours, and an aqueous dispersion of a vinyl resin (a copolymer of styrene-methacrylic acid-methacrylic acid ethylene oxide adduct sulfate sodium salt) [fine particles Dispersion] was obtained. The volume average particle diameter of the [fine particle dispersion] measured by LA-920 was 0.14 μm. A part of the [fine particle dispersion] was dried to isolate the resin component.
-Adjustment of aqueous phase-
990 parts of water, 83 parts of [fine particle dispersion], 37 parts of 48.5% aqueous solution of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7: manufactured by Sanyo Chemical Industries) and 90 parts of ethyl acetate were mixed and stirred to give a milky white liquid. Obtained. This was designated as [aqueous phase].

-Emulsification / solvent removal-
[Pigment / WAX Dispersion] 664 parts, [Prepolymer] 109.4 parts, [Crystalline Polyester Dispersion] 73.9 parts, [Ketimine Compound] 4.6 parts in a container, and TK homomixer ( After mixing at 5,000 rpm for 1 minute using a special machine, add 1,200 parts of [water phase] to the container and mix with a TK homomixer at 13,000 rpm for 20 minutes to obtain [emulsified slurry]. It was.
[Emulsion slurry] was put into a container equipped with a stirrer and a thermometer, and after removing the solvent at 30 ° C. for 8 hours, aging was carried out at 45 ° C. for 4 hours to obtain [dispersed slurry].
-Cleaning and drying-
[Dispersion slurry] After filtering 100 parts under reduced pressure,
(1): 100 parts of ion-exchanged water was added to the filter cake, mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered.
(2): 100 parts of a 10% aqueous sodium hydroxide solution was added to the filter cake of (1), mixed with a TK homomixer (30 minutes at 12,000 rpm), and then filtered under reduced pressure.
(3): 100 parts of 10% hydrochloric acid was added to the filter cake of (2), mixed with a TK homomixer (rotation speed: 12,000 rpm for 10 minutes), and then filtered.
(4): 300 parts of ion exchange water was added to the filter cake of (3), mixed with a TK homomixer (10 minutes at 12,000 rpm), and then filtered twice to obtain [filter cake]. .
[Filter cake] was dried with a circulating dryer at 45 ° C. for 48 hours, and sieved toner base particles were obtained with an opening of 75 μm mesh. Among the toner base particles, those having high hydrophilicity are likely to be unevenly distributed on the surface of the toner, so that the fluorescent pigment in the toner is present in the vicinity of the surface.
-External treatment-
With respect to 100 parts by mass of the toner base particles, 2.0 parts by mass of silica having an average particle diameter of 20 nm was mixed with a Henschel mixer, and passed through a sieve having an opening of 500 mesh, whereby a black fluorescent toner 8 was obtained.

(Production example of black fluorescent toner 9)
In the same manner as the black fluorescent toner 8, toner base particles were obtained. To 100 parts of toner base particles, 1.5 parts by mass of silica fine particles (manufactured by Clariant Co., Ltd., HDK-2000) and 1 part of Lumogen Yellow S 0795 (manufactured by BASF Japan Co., Ltd.) are stirred and mixed with a Henschel mixer, and black fluorescent toner 9 was produced.

(Example of production of black fluorescent toner 10)
A black fluorescent toner 10 was produced in the same manner as the black fluorescent toner 8 except that the oil phase was prepared as follows.
-Creation of oil phase-
A container equipped with a stir bar and a thermometer was charged with 378 parts of [Non-crystalline polyester], 110 parts of Carnauba WAX, 22 parts of CCA (salicylic acid metal complex E-84: Orient Chemical Industry), and 947 parts of ethyl acetate. The temperature was raised to 0 ° C., kept at 80 ° C. for 5 hours, and then cooled to 30 ° C. over 1 hour. Next, 500 parts of [Masterbatch], 22.4 parts of Lumogen Yellow S 0795 (manufactured by BASF Japan Ltd.) and 500 parts of ethyl acetate were charged into the container and mixed for 1 hour to obtain [Raw material solution 2].

(Comparative example)
(Example of production of black toner 1)
Toner base particles were obtained in the same manner as the black fluorescent toner 8 except that 22.4 parts of Yellow 1057-YD were removed in the oil phase preparation step of the black fluorescent toner 8. With respect to 100 parts of the toner base particles, 1.5 parts by mass of silica fine particles (manufactured by Clariant Co., Ltd., HDK-2000) was stirred and mixed with a Henschel mixer to produce black toner 1.

(Example of production of two-component developer)
<Creation of carrier>
Silicone resin (organostraight silicone) 100 parts Toluene 100 parts γ- (2-Aminoethyl) aminopropyltrimethoxysilane 5 parts Carbon black 10 parts The above mixture is dispersed with a homomixer for 20 minutes to prepare a coating layer forming solution. did. Using this coating layer forming liquid, as a core material, Mn ferrite particles having a weight average particle diameter of 35 μm, and using a fluidized bed type coating apparatus so that the average film thickness is 0.20 μm on the core material surface, The temperature in the fluidized tank was controlled to 70 ° C. and applied and dried. The obtained carrier was baked in an electric furnace at 180 ° C./2 hours to obtain carrier A.

Using the black fluorescent toners 1 to 10 and the black toner 1 prepared in the above examples and comparative examples, a two-component developer was prepared as follows.
<Preparation of two-component developer>
Each of the produced black fluorescent toner or black toner and carrier A are uniformly mixed and charged at 48 rpm for 5 minutes using a tumbler mixer (manufactured by Willy et Bacofen (WAB)), and each is a two-component developer. Was made. The mixing ratio of the toner and the carrier was matched with the toner concentration of the initial developer of the evaluation machine.

The two-component developer having black fluorescent toner or black toner was evaluated as follows.
<Visibility (under UV irradiation)>
Using a Ricoh digital full-color multifunction machine, Imagio Neo C600 remodeling machine (linear speed is 320 mm / sec), a 4 cm square solid image is formed on each two-component developer so that the adhesion amount is 0.4 mg / cm ² and fixed. After fixing at a temperature of 160 ° C. and an NIP width of 15 mm, the fluorescence of the image was visually evaluated under ultraviolet irradiation.
The paper used for the evaluation was POD gloss coated paper 128 g / m ² made by Oji Paper.
[Evaluation criteria]
○: Good △: Acceptable level ×: Not acceptable

<Visibility (under visible light)>
The sample used for the visibility (under ultraviolet irradiation) was visually observed under visible light, and the blackness of the image was evaluated.
[Evaluation criteria]
○: Black △: Tint black

<Light resistance>
The fade meter was tested by irradiation for 48 hours, and the degree of discoloration at that time was visually evaluated.
[Evaluation criteria]
○: Good △: Acceptable level ×: Not acceptable

<Security (Comprehensive evaluation)>
Visibility (under ultraviolet irradiation), visibility (under visible light), and light resistance were evaluated between A and D based on the total score of the points shown below. Moreover, the thing containing x was set to evaluation D for security.
Criteria for visibility (ultraviolet irradiation) ○: 2 points △: 1 point ×: 0 points Criteria for visibility (under visible light) ○: 2 points △: 1 point ×: 0 points Criteria for light resistance ○ : 2 points △: 1 point ×: 0 point
[Evaluation criteria]
A: 5 to 6 points B: 4 points C: 2 to 3 points D: 0 to 2 points The above evaluation results are shown in Table 1 below.

Aspects of the present invention are as follows, for example.
<1> A toner containing at least a binder resin and a colorant, wherein the colorant contains carbon black and a fluorescent agent.
<2> The toner according to <1>, wherein a peak wavelength of a fluorescence spectrum of the fluorescent agent is in a wavelength region of 450 nm to 780 nm.
<3> The toner according to any one of <1> to <2>, wherein a peak wavelength of an absorption spectrum of the fluorescent agent is not in a visible light region.
<4> The toner according to any one of <1> to <3>, wherein a fluorescent agent is present in the vicinity of the toner surface.
<5> The toner according to <4>, wherein the fluorescent agent is externally added to the toner.
<6> The toner according to <4>, wherein the toner includes a core and a shell layer, and the shell layer includes the fluorescent agent.
<7> A toner storage unit that stores the toner according to any one of <1> to <6>.
<8> an electrostatic latent image carrier, and electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier;
Developing means comprising toner for developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image;
Transfer means for transferring the toner image formed on the electrostatic latent image carrier onto the surface of a recording medium;
Fixing means for fixing the toner image transferred to the surface of the recording medium,
An image forming apparatus, wherein the toner is the toner according to any one of <1> to <6>.

  According to the toner according to any one of <1> to <6>, the toner storage unit according to <7>, and the image forming apparatus according to <8>, the conventional problems are solved. The object of the present invention can be achieved.

JP 2003-118276 A JP 2011-191405 A

Claims (8)

  A toner containing at least a binder resin and a colorant, wherein the colorant contains carbon black and a fluorescent agent.   The toner according to claim 1, wherein a peak wavelength of a fluorescence spectrum of the fluorescent agent is in a wavelength region of 450 nm to 780 nm.   The toner according to claim 1, wherein a peak wavelength of an absorption spectrum of the fluorescent agent is not in a visible light region.   The toner according to claim 1, wherein a fluorescent agent is present in the vicinity of the toner surface.   The toner according to claim 4, wherein the fluorescent agent is externally added to the toner.   The toner according to claim 4, wherein the toner includes a core and a shell layer, and the shell layer contains the fluorescent agent.   A toner containing unit containing the toner according to claim 1. An electrostatic latent image carrier, and electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier;
Developing means comprising toner for developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image;
Transfer means for transferring the toner image formed on the electrostatic latent image carrier onto the surface of a recording medium;
Fixing means for fixing the toner image transferred to the surface of the recording medium,
The image forming apparatus according to claim 1, wherein the toner is the toner according to claim 1.