Resin particles

Abstract

The present invention relates to resin particles. In the resin particles, a fluorescent colorant is chemically bonded to a binding resin.

Description

Technical Field

[0001] This invention relates to resin particles. Background Technology

[0002] Resin particles have various applications, one of which is as a toner in electrophotography. The toners described in the following patent documents are well-known as existing toners.

[0003] Japanese Patent Application Publication No. 2017-3818 discloses a coloring agent containing a binding resin and a colorant, characterized in that the colorant contains a coloring pigment and a fluorescent dye, wherein the mass percentages of the coloring pigment and the fluorescent dye in the coloring agent are respectively W. G W F At that time, the above W G And the above W F Satisfy the following equation (1),

[0004] W G ×0.5>W F >W G ×0.025 (1)

[0005] Let the absorption peak wavelength of the above-mentioned coloring pigment be P. G Let the peak emission wavelength of the above fluorescent dye be P. F At that time, the above P G And the above P F It satisfies the following equation (2).

[0006] P G <P F (2)

[0007] Japanese Patent Application Publication No. 11-119472 discloses a negatively charged magenta toner for electrophotography, characterized in that it is made by mixing a binding resin and other colorant materials, if necessary, into a magenta colorant obtained by thermally mixing rhodamine dye and a high acid value resin.

[0008] Japanese Patent Application Publication No. 54-5733 discloses a colorant, characterized in that it contains a heat-treated mixture of an alkaline dye and a resin with an acid value of 5 to 120 as a colorant in an adhesive resin. Summary of the Invention

[0009] The technical problem that the invention aims to solve

[0010] The technical problem to be solved by the present invention is to provide a resin particle that produces an image with high fluorescence intensity compared to a case where the fluorescent colorant is not chemically bonded to the binding resin or is simply dispersed without being dispersed at the molecular level in the binding resin.

[0011] Means for solving technical problems

[0012] According to a first aspect of the present invention, a resin particle is provided, wherein a fluorescent colorant is chemically bonded to an adhesive resin.

[0013] According to a second aspect of the present invention, a resin particle is provided, wherein a fluorescent colorant is dispersed at the molecular level in an adhesive resin.

[0014] According to the third aspect of the present invention, the above-mentioned resin particles are core / shell type particles.

[0015] According to the fourth aspect of the present invention, the fluorescent colorant is not exposed on the surface.

[0016] According to the fifth aspect of the present invention, the above-mentioned chemical bonding is ionic bonding.

[0017] According to the sixth aspect of the present invention, the adhesive resin has anionic groups and the fluorescent colorant has cationic groups.

[0018] According to the seventh aspect of the present invention, the adhesive resin has cationic groups and the fluorescent colorant has anionic groups.

[0019] According to the eighth aspect of the present invention, the fluorescent colorant is a fluorescent dye.

[0020] According to the ninth aspect of the present invention, the fluorescent dye includes a fluorescent dye having a maximum fluorescence wavelength in the wavelength range of 580 nm to 650 nm.

[0021] The effects of the invention

[0022] According to the above-mentioned schemes 1, 2 or 9, a resin particle is provided that, compared with the case where the fluorescent colorant is not chemically bonded to the binder resin or is simply dispersed without being dispersed at the molecular level in the binder resin, the image obtained by using the resin particle of this scheme has a high fluorescence intensity.

[0023] According to the third solution above, a resin particle is provided, and compared with the case where the resin particle is a single-layer toner particle, the graininess (granularity) of the image obtained using the resin particle of this solution is suppressed.

[0024] According to the fourth embodiment described above, a resin particle is provided, and compared with the case where the shell contains a fluorescent colorant, the graininess of the image obtained using the resin particle of this embodiment is further suppressed.

[0025] According to the above-mentioned schemes 5, 6 or 7, a resin particle is provided, which, compared with the above-mentioned case where the chemical bonding is hydrogen bonded, further improves the fluorescence intensity of the image obtained by using the resin particle of this scheme.

[0026] According to the eighth embodiment described above, a resin particle is provided, and compared with the case where the fluorescent colorant is a fluorescent pigment, the fluorescence intensity of the image obtained using the resin particle of this embodiment is further improved. Attached Figure Description

[0027] Figure 1 A schematic configuration diagram of the image forming apparatus used in this embodiment is shown.

[0028] Figure 2 A schematic configuration diagram of the processing box used in this embodiment is shown.

[0029] Figure 3 This shows an example of the spectrum for each color of the fluorescent color. The vertical axis represents fluorescence intensity, and the horizontal axis represents wavelength. It should be noted that "mμ" = "nm". Detailed Implementation

[0030] In this specification, when referring to the amount of each component in the composition, if there are two or more substances corresponding to each component in the composition, it refers to the total amount of the two or more substances present in the composition unless otherwise stated.

[0031] In this manual, "electrostatic image developing toner" is also referred to as "toner" and "electrostatic image developing agent" is also referred to as "developer".

[0032] The following describes an embodiment as an example of the present invention.

[0033] <Resin Particles>

[0034] The first embodiment of the resin particles in this embodiment is resin particles in which a fluorescent colorant is chemically bonded to an adhesive resin.

[0035] The second embodiment of the resin particles in this embodiment is a resin particle in which a fluorescent colorant is dispersed at the molecular level in the adhesive resin.

[0036] In recent years, various companies have released printing presses for commercial printing, publishing, and paper packaging, as well as models featuring spot color toners, in the digital printing industry. Regarding fluorescent colors, most companies use color sample books or color charts such as PANTONE's Neons Guide, DIC's DIC Color Guide, or Toyo Ink's COLORFINDER, selecting a range of colors from strong to pale fluorescent hues, similar to how they use regular spot colors. However, fluorescent colorants exhibit properties known as concentration-induced extinction and self-extinction. This means that if the fluorescent colorant is at a high concentration, the fluorescence intensity decreases, and the ratio of concentration to intensity no longer holds. It can be inferred that this phenomenon is due to the interaction between fluorescent molecules, causing the primary fluorescence to be reabsorbed by other molecules, or energy transfer between adjacent molecules instead of releasing all the original energy.

[0037] The resin particles in this embodiment, configured as described above, result in images with high fluorescence intensity. The reason for this is not yet certain, but it is presumed to be due to the reasons explained below.

[0038] By using fluorescent colorants chemically bonded to the resin particles of the binding resin, or by dispersing fluorescent colorants at the molecular level in the resin particles of the binding resin, concentration extinction and self-extinction can be suppressed. That is, the phenomenon that the fluorescence emitted in the first emission is reabsorbed by other molecules and the phenomenon that energy transfer occurs between adjacent molecules instead of releasing all the original energy to the outside are suppressed, resulting in images with high fluorescence intensity.

[0039] The resin particles of this embodiment will now be described in detail.

[0040] It should be noted that, unless otherwise specified, the use of the term "resin particles of this embodiment" or "resin particles" in this specification refers to both the first embodiment and the second embodiment described above.

[0041] The resin particles in this embodiment are resin particles in which fluorescent colorants are chemically bonded to adhesive resin, or resin particles in which fluorescent colorants are dispersed at the molecular level in adhesive resin. Depending on the need, they may contain other colorants besides fluorescent colorants, release agents and other additives. Preferably, they contain adhesive resin, fluorescent colorants, other colorants and release agents.

[0042] Furthermore, from the perspective of fluorescence intensity and image graininess, the aforementioned resin particles are preferably resin particles in which the fluorescent colorant is chemically bonded to the adhesive resin and dispersed at the molecular level in the adhesive resin.

[0043] In the first embodiment of the resin particles in this embodiment, the resin particles are resin particles in which a fluorescent colorant is chemically bonded to an adhesive resin.

[0044] Examples of the aforementioned chemical bonds include ionic bonds, covalent bonds, hydrogen bonds, and bonds based on dipole interactions (van der Waals bonds).

[0045] From the perspective of fluorescence intensity, the preferred bond is at least one bond selected from the group consisting of ionic bonds, covalent bonds, and hydrogen bonds; more preferably, it is at least one bond selected from the group consisting of ionic bonds and hydrogen bonds; and particularly preferably, it is an ionic bond.

[0046] Furthermore, when the aforementioned fluorescent colorant is ionicly bonded to the aforementioned adhesive resin, from the perspectives of fluorescence intensity and image graininess, it is preferable that the adhesive resin has anionic groups and the fluorescent colorant has cationic groups. Additionally, from the perspectives of fluorescence intensity and abrasion resistance, it is preferable that the adhesive resin has cationic groups and the fluorescent colorant has anionic groups. When the adhesive resin has cationic groups, the fixed image bonds with the anionic groups such as hydroxyl and carboxyl groups of cellulose contained in the paper, which is expected to improve image intensity.

[0047] Regarding the graininess, for example, when anionic resins are used as adhesive resins and cationic dyes are used as fluorescent colorants, anionic resins have more functional groups than cationic dyes, thus the resin particles as a whole are anionic. The additives described later are also anionic and charged; as a whole, the charge shift is small, reducing dot scattering during transfer and maintaining intact dots, thus resulting in a superior graininess.

[0048] Furthermore, when cationic resins are used as adhesive resins and anionic dyes are used as fluorescent colorants, the resin particles as a whole are cationic, contrary to the above. Since the additives described later are anionic and charged, resin particles with increased charge shift are easily generated in the form of dot scattering during transfer. In most cases, the particle texture is slightly worse than in the above cases.

[0049] Regarding abrasion resistance, for example, in the fibers of paper used as a recording medium, cellulose is the main component, and the surface has hydroxyl groups that carry a negative charge.

[0050] The resin particles melt under the heat during fixing and penetrate into the paper fibers. The unevenness of the bonding surface acts like an anchor, thus achieving physical bonding. This is called the anchoring effect.

[0051] When anionic resins are used as adhesive resins and cationic dyes are used as fluorescent colorants, the resin particles as a whole are anionic, which electrically repels the anionic nature of the paper, and fixing is achieved solely through an anchoring effect.

[0052] On the other hand, when cationic resins are used as adhesive resins and anionic dyes are used as fluorescent colorants, the resin particles as a whole are cationic and electrically bonded to the anionic nature of the paper. In addition to the anchoring effect, ionic bonds are used for fixing, thus improving the image strength (friction strength, abrasion resistance).

[0053] Furthermore, from the perspective of fluorescence intensity and image graininess, the value of (molar amount of ionic groups in the adhesive resin contained in the resin particles) / (molar amount of ionic groups in the fluorescent colorant contained in the resin particles) is preferably 1 or more, more preferably 1.5 or more, further preferably 2 or more, and particularly preferably 2 or more and 10 or less.

[0054] In the first embodiment of the resin particles of this embodiment, from the perspective of fluorescence intensity and image graininess, relative to the total mass of the fluorescent colorant contained in the resin particles, it is preferable that 50% or more of the fluorescent colorant is chemically bonded to the adhesive resin, more preferably 80% or more of the fluorescent colorant is chemically bonded to the adhesive resin, even more preferably 90% or more of the fluorescent colorant is chemically bonded to the adhesive resin, and particularly preferably all of the fluorescent colorant is chemically bonded to the adhesive resin.

[0055] The confirmation that the fluorescent colorant in the above resin particles is chemically bonded to the adhesive resin is carried out by the following method.

[0056] It can be performed using Fourier transform infrared spectroscopy (FT-IR), ultraviolet-visible spectroscopy (UV-vis spectroscopy), nuclear magnetic resonance analysis (NMR), gas chromatography-mass spectrometry (GC-MS), etc.

[0057] In the second embodiment of the resin particles in this embodiment, the resin particles are resin particles in which fluorescent colorants are dispersed at the molecular level in the adhesive resin.

[0058] In this embodiment, "dispersion at the molecular level" means that the fluorescent colorant molecules are not dispersed in the form of aggregates (associations) of two or more molecules (e.g., fluorescent colorant particles), but rather dispersed in a monomolecular state (monomolecular dispersion). In this embodiment, the case where the fluorescent colorant is chemically bonded to the adhesive resin in a monomolecular state is also included in monomolecular dispersion.

[0059] In the first embodiment of the resin particles of this embodiment, from the perspective of fluorescence intensity and image graininess, the resin particles are preferably resin particles in which the fluorescent colorant is chemically bonded to the adhesive resin and dispersed at the molecular level.

[0060] There are no particular limitations on the method used in this embodiment to disperse the fluorescent colorant at the molecular level in the binder resin. Examples include methods for chemically bonding the fluorescent colorant to the binder resin; methods using a fluorescent dye that is soluble in or compatible with the binder resin and dissolving it in or being compatible with the binder resin; methods for removing the solvent from a solution obtained by dissolving the fluorescent colorant and the binder resin in a solvent; and so on. Among these, methods for chemically bonding the fluorescent colorant to the binder resin are preferred.

[0061] In the second embodiment of the resin particles of this embodiment, from the perspective of fluorescence intensity and image graininess, relative to the total mass of the fluorescent colorant contained in the resin particles, it is preferable that 50% or more of the fluorescent colorant in the resin particles is dispersed at the molecular level in the binding resin, more preferably 80% or more of the fluorescent colorant is dispersed at the molecular level in the binding resin, even more preferably 90% or more of the fluorescent colorant is dispersed at the molecular level in the binding resin, and particularly preferably all of the fluorescent colorant is dispersed at the molecular level in the binding resin.

[0062] The confirmation that the fluorescent colorant in the above resin particles is dispersed at the molecular level in the adhesive resin is carried out by the following method.

[0063] In the presence of insoluble fluorescent colorants, they are observed as fine aggregates (clumps). Therefore, if no aggregates (clumps) of the fluorescent dye are identified, it can be considered to be dispersed at the molecular level. The identification of these clumps is performed by observing the cross-section using TEM or by filtering the solution after dissolution.

[0064] Furthermore, as a method for manufacturing resin particles in this embodiment, it is preferable to use a method that uses at least fluorescent colorant ions bonded to the surface of the resin particles, and more preferably, a method that includes a step of producing resin particles by condensing and agglomerating resin particles with at least fluorescent colorant ions bonded to the surface in a coagulation and agglomeration method (coagulation method 1).

[0065] Furthermore, from the perspective of fluorescence intensity and image graininess, the resin particles in this embodiment are preferably particles formed by agglomerating resin particles in which at least fluorescent colorants are chemically bonded to the adhesive resin, and more preferably particles formed by agglomerating resin particles in which at least fluorescent colorants are ionicly bonded to the adhesive resin.

[0066] -Fluorescent colorant-

[0067] The fluorescent colorant is any colorant that exhibits fluorescence, and preferably a colorant that exhibits fluorescence in the visible light region (wavelength 380 nm to 760 nm). Furthermore, there are no particular limitations on the light that excites the fluorescent colorant, but it is preferable to include at least visible light or ultraviolet light, and more preferably at least ultraviolet light.

[0068] Furthermore, from the perspective of chemical bonding with adhesive resins and ease of dispersion, fluorescent colorants are preferably fluorescent dyes.

[0069] It should be noted that in this embodiment, "pigment" refers to a colorant whose solubility in 100g of water at 23°C and in 100g of cyclohexanone at 23°C is less than 0.1g, and "dye" refers to a colorant whose solubility in 100g of water at 23°C or in 100g of cyclohexanone at 23°C is 0.1g or more.

[0070] Furthermore, from the perspective of chemical bonding and ease of dispersion with the adhesive resin, the fluorescent colorant preferably has chemically bondable groups, more preferably has ionic groups, and particularly preferably has cationic or anionic groups.

[0071] As a cationic group, from the perspective of fluorescence intensity and image graininess, ononium group is preferred, ammonium group, imine ion group or pyridinium group is more preferred, ammonium group is even more preferred, and quaternary ammonium group is particularly preferred.

[0072] Furthermore, the fluorescent colorant may have only one ionic group or two or more ionic groups. From the perspective of fluorescence intensity and image graininess, it is preferable to have one or more but no more than four ionic groups, more preferably one or two ionic groups, and particularly preferably only one ionic group.

[0073] As an anionic group, from the perspective of fluorescence intensity and image graininess, it is preferable to have at least one group selected from the group consisting of acid groups and their salts, more preferably to have at least one group selected from the group consisting of sulfonyl, carboxyl and their salts, and particularly preferably to have at least one group selected from the group consisting of sulfonyl and their salts.

[0074] Furthermore, when the fluorescent colorant forms a chemical bond with the adhesive resin, an anionic group, for example, -SO3, can be preferably used. - and -COO - More preferably, -SO3 can be cited as an example. - .

[0075] In addition, there are no particular restrictions on the color of fluorescent colorants; they can be selected appropriately according to the desired effect.

[0076] Examples of fluorescent colorants include fluorescent pink, fluorescent red, fluorescent orange, fluorescent yellow, fluorescent green, and fluorescent purple colorants.

[0077] The preferred colorant is a fluorescent pink colorant, a fluorescent red colorant, a fluorescent orange colorant, a fluorescent yellow colorant, or a fluorescent green colorant, more preferably a fluorescent pink colorant, a fluorescent yellow colorant, or a fluorescent green colorant, and particularly preferably a fluorescent pink colorant.

[0078] Furthermore, the resin particles in this embodiment are preferably fluorescent resin particles, more preferably fluorescent pink resin particles, fluorescent yellow resin particles, or fluorescent green resin particles, and particularly preferably fluorescent pink resin particles.

[0079] The fluorescence peak wavelength (maximum fluorescence wavelength) of the fluorescent colorant in the spectrophotometric reflectance can be appropriately selected according to the desired color. For example, if it is desired to exhibit a fluorescent pink color, it is preferable to have a fluorescence peak wavelength between 560 nm and 670 nm, and more preferably between 580 nm and 650 nm.

[0080] Figure 3 An example of the spectrum of each color of fluorescent color is shown.

[0081] Furthermore, from the perspective of image graininess, the spectral reflectance of the fluorescent colorant at the aforementioned fluorescence peak wavelength is preferably 100% or more, more preferably 105% or more, and particularly preferably 110% or more.

[0082] As fluorescent colorants, known fluorescent colorants can be used, specifically, examples include Basic Red 1 (Rhodamine 6G), Basic Red 1:1, Basic Red 2, Basic Red 12, Basic Red 13, Basic Red 14, Basic Red 15, Basic Red 36, Basic Violet 7, Basic Violet 10 (Rhodamine B), Basic Violet 11 (Rhodamine 3B), Basic Violet 11:1 (Rhodamine A), Basic Violet 15, Basic Violet 16, Basic Violet 27, Pigment Yellow 101, and Basic Violet 16. Basic Yellow 1, Basic Yellow 2, Basic Yellow 9, Basic Yellow 24, Basic Yellow 40, Basic Orange 15, Basic Orange 22, Basic Blue 1, Basic Blue 3, Basic Blue 7, Basic Blue 9, Basic Blue 45, Basic Green 1, Acid Yellow 3, Acid Yellow 7, Acid Yellow 73, Acid Yellow 87, Acid Yellow 184, Acid Yellow 245, Acid Yellow 250, Acid Red 51, Acid Red 52, Acid Red 57, Acid Red 77, Acid Red 87, Acid Red 89, Acid Red 92, Acid Blue 9. Acid Black 2, Solvent Yellow 43, Solvent Yellow 44, Solvent Yellow 85, Solvent Yellow 98, Solvent Yellow 116, Solvent Yellow 131, Solvent Yellow 145, Solvent Yellow 160:1, Solvent Yellow 172, Solvent Yellow 185, Solvent Yellow 195, Solvent Yellow 196, Solvent Orange 63, Solvent Orange 112, Solvent Red 49, Solvent Red 149, Solvent Red 175, Solvent Red 196, Solvent Red 197, Solvent Blue 5, Solvent Green 5, Solvent Green 7, Direct Yellow 27 Direct Yellow 85, Direct Yellow 96, Direct Orange 8, Direct Red 2, Direct Red 9, Direct Blue 22, Direct Blue 199, Direct Green 6, Disperse Yellow 11, Disperse Yellow 82, Disperse Yellow 139, Disperse Yellow 184, Disperse Yellow 186, Disperse Yellow 199, Disperse Yellow 202, Disperse Yellow 232, Disperse Orange 11, Disperse Orange 32, Disperse Red 58, Disperse Red 274, Disperse Red 277, Disperse Red 303, Disperse Blue 7, Reactive Yellow 78, Reducing Red 41, etc.

[0083] These fluorescent colorants can be selected from one or more depending on the desired color. For example, when it is desired to exhibit a fluorescent pink color, it is preferable to select at least one fluorescent colorant from the group consisting of Basic Red 1 (Rhodamine 6G), Basic Red 1:1, Basic Red 2, Basic Red 12, Basic Red 13, Basic Red 14, Basic Red 15, Basic Red 36, Basic Violet 7, Basic Violet 10 (Rhodamine B), Basic Violet 11 (Rhodamine 3B), Basic Violet 11:1 (Rhodamine A), Basic Violet 15, Basic Violet 16, and Basic Violet 27.

[0084] Furthermore, from the perspective of fluorescence intensity and image graininess, fluorescent colorants containing a xatonne structure, a naphthalene structure, or a triarylmethane structure are preferred, and fluorescent colorants containing a xatonne structure are more preferred.

[0085] In addition, the zeolite structure is preferably a rhodamine structure, a fluorescein structure, or an eosin structure, and more preferably a rhodamine structure.

[0086] As fluorescent colorants with cationic groups, from the perspective of fluorescence intensity and image graininess, preferred examples include Basic Red 1 (Rhodamine 6G), Basic Red 1:1, Basic Red 2, Basic Red 12, Basic Red 13, Basic Red 14, Basic Red 15, Basic Red 36, Basic Violet 7, Basic Violet 10 (Rhodamine B), Basic Violet 11 (Rhodamine 3B), Basic Violet 11:1 (Rhodamine A), Basic Violet 15, Basic Violet 16, Basic Violet 27, Basic Yellow 1, Basic Yellow 2, Basic Yellow 9, and Basic... Yellow 24, Basic Yellow 40, Basic Orange 15, Basic Orange 22, Basic Blue 1, Basic Blue 3, Basic Blue 7, Basic Blue 9, Basic Blue 45, Basic Green 1, and more preferably Basic Red 1 (Rhodamine 6G), Basic Red 1:1, Basic Red 2, Basic Red 12, Basic Red 13, Basic Red 14, Basic Red 15, Basic Red 36, Basic Violet 7, Basic Violet 10 (Rhodamine B), Basic Violet 11 (Rhodamine 3B), Basic Violet 11:1 (Rhodamine A), Basic Violet 15, Basic Violet 16, Basic Violet 27.

[0087] Furthermore, from the perspective of fluorescence intensity and image graininess, the preferred fluorescent colorants having anionic groups include Acid Yellow 3, Acid Yellow 7, Acid Yellow 73, Acid Yellow 87, Acid Yellow 184, Acid Yellow 245, Acid Yellow 250, Acid Red 51, Acid Red 52, Acid Red 57, Acid Red 77, Acid Red 87, Acid Red 89, Acid Red 92, Acid Blue 9, and Acid Black 2. More preferred examples include Acid Red 51, Acid Red 52, Acid Red 57, Acid Red 77, Acid Red 87, Acid Red 89, and Acid Red 92.

[0088] Resin particles may contain a single fluorescent colorant or a combination of two or more fluorescent colorants.

[0089] The content of the fluorescent colorant, from the perspective of fluorescence intensity and image graininess, is preferably 0.2% to 5% by mass, more preferably 0.2% to 3% by mass, and particularly preferably 0.2% to 2% by mass, relative to the total amount of resin particles.

[0090] -Adhesive resin-

[0091] Examples of adhesive resins include vinyl resins formed from homopolymers of monomers or copolymers of two or more of these monomers, such as: styrene (e.g., styrene, p-chlorostyrene, α-methylstyrene, etc.), (meth)acrylates (e.g., methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate, etc.), olefinic unsaturated nitriles (e.g., acrylonitrile, methacrylonitrile, etc.), vinyl ethers (e.g., vinyl methyl ether, vinyl isobutyl ether, etc.), vinyl ketones (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropylene ketone, etc.), and olefins (e.g., ethylene, propylene, butadiene, etc.).

[0092] Examples of adhesive resins include non-vinyl resins such as epoxy resins, polyester resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and modified rosin, mixtures of these resins with the aforementioned vinyl resins, or graft polymers obtained by polymerizing vinyl monomers in their coexistence.

[0093] Styrene-acrylic acid copolymer or polyester resin are suitable, with polyester resin being more suitable.

[0094] These adhesive resins can be used alone or in combination of two or more.

[0095] Furthermore, the glass transition temperature of the adhesive resin is preferably 90°C or less, more preferably 80°C or less, and particularly preferably 50°C or more and 80°C or less.

[0096] Furthermore, as an adhesive resin, from the perspective of fluorescence intensity and image graininess, it is preferable to have ionic groups, and more preferably to have cationic or anionic groups.

[0097] As cationic groups, amino or ammonium groups are preferred from the perspective of fluorescence intensity and image graininess.

[0098] As an anionic group, from the perspective of fluorescence intensity and image graininess, carboxyl, sulfonyl or their salts are preferred, and carboxyl or its salts are more preferred.

[0099] Among them, from the perspective of fluorescence intensity and image abrasion resistance, the resin containing cationic groups preferably includes a styrene-acrylic acid copolymer containing amino groups, and more preferably includes a styrene-acrylic acid copolymer containing amino structural units.

[0100] Furthermore, from the perspective of fluorescence intensity and image graininess, polyester resins containing at least one group selected from the group consisting of carboxyl groups and their salts, or styrene-acrylic resins containing at least one group selected from the group consisting of carboxyl groups and their salts, are preferred as resins containing at least one group selected from the group consisting of carboxyl groups and their salts. Polyester resins containing at least one group selected from the group consisting of carboxyl groups and their salts are more preferred.

[0101] Examples of adhesive resins include amorphous (also known as "non-crystalline") resins and crystalline resins.

[0102] From the perspective of suppressing uneven concentration in the obtained image, the adhesive resin preferably includes a crystalline resin, more preferably an amorphous resin and a crystalline resin.

[0103] The content of crystalline resin relative to the total mass of adhesive resin is preferably 2% to 40% by mass, more preferably 2% to 20% by mass.

[0104] It should be noted that the "crystallization" of the resin means that there is no step-like change in endothermic heat in differential scanning calorimetry (DSC) and there is a clear endothermic peak. Specifically, it means that the half-peak width of the endothermic peak is within 10°C when the measurement is performed at a heating rate of 10°C / min.

[0105] On the other hand, the "amorphousness" of resin refers to a full width at half maximum (FWHM) greater than 10°C, exhibiting a step-like change in endothermic heat, or the absence of a clear endothermic peak.

[0106] <<Polyester Resin>>

[0107] Examples of polyester resins include, for instance, well-known polyester resins.

[0108] Amorphous polyester resin

[0109] Examples of amorphous polyester resins include condensation polymers of polycarboxylic acids and polyols. It should be noted that both commercially available and synthetic amorphous polyester resins can be used.

[0110] Examples of polycarboxylic acids include, for example, aliphatic dicarboxylic acids (such as oxalic acid, malonic acid, maleic acid, fumaric acid, citracic acid, itaconic acid, pentenic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.), alicyclic dicarboxylic acids (such as cyclohexanedicarboxylic acid, etc.), aromatic dicarboxylic acids (such as terephthalic acid, isophthalic acid, phthalic acid, naphthalenedicarboxylic acid, etc.), their anhydrides, or their lower (e.g., alkyl esters with 1 to 5 carbon atoms). Among these, aromatic dicarboxylic acids are preferred as polycarboxylic acids.

[0111] In polycarboxylic acids, dicarboxylic acids can be used in combination with carboxylic acids of three or more members that have a cross-linked or branched structure. Examples of carboxylic acids of three or more members include trimellitic acid, benzopyrene, their anhydrides, or their lower (e.g., 1-5 carbon atoms) alkyl esters.

[0112] Polycarboxylic acids can be used alone or in combination of two or more.

[0113] Examples of polyols include aliphatic diols (such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol, etc.), alicyclic diols (such as cyclohexanediol, cyclohexanediol, hydrogenated bisphenol A, etc.), and aromatic diols (such as ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, etc.). Among these, aromatic diols and alicyclic diols are preferred as polyols, and aromatic diols are more preferred.

[0114] As a polyol, a diol can be used in combination with a polyol of three or more members that has a cross-linked or branched structure. Examples of polyols of three or more members include glycerol, trimethylolpropane, and pentaerythritol.

[0115] Polyols can be used alone or in combination of two or more.

[0116] The glass transition temperature (Tg) of the amorphous polyester resin is preferably 50°C or higher and 80°C or lower, more preferably 50°C or higher and 65°C or lower.

[0117] It should be noted that the glass transition temperature is determined by the DSC curve obtained by differential scanning calorimetry (DSC), or more specifically, by extrapolating the glass transition onset temperature as described in the method for determining the glass transition temperature in JIS K7121:1987 "Method for determination of transition temperature of plastics".

[0118] The weight-average molecular weight (Mw) of the amorphous polyester resin is preferably 5,000 or more and 1,000,000 or less, more preferably 7,000 or more and 500,000 or less.

[0119] The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2,000 or more and 100,000 or less.

[0120] The molecular weight distribution of the amorphous polyester resin, Mw / Mn, is preferably 1.5 to 100, more preferably 2 to 60.

[0121] It should be noted that the weight-average molecular weight and number-average molecular weight were determined by gel permeation chromatography (GPC). For the molecular weight determination using GPC, a Tosoh HLC-8120 GPC (manufactured by Tosoh Corporation) was used, along with a Tosoh TSKgel SuperHM-M (15 cm) column, and THF solvent was employed. The weight-average molecular weight and number-average molecular weight were calculated from these results using a molecular weight calibration curve prepared from monodisperse polystyrene standard samples.

[0122] Amorphous polyester resins are obtained by known manufacturing methods. Specifically, for example, they are obtained by the following method: the polymerization temperature is set to 180°C or higher and 230°C or lower, and the reaction system is subjected to reduced pressure as needed, while removing water or alcohol generated during condensation.

[0123] It should be noted that if the raw material monomers are insoluble or incompatible at the reaction temperature, a high-boiling-point solvent can be added as a dissolving agent to dissolve them. In this case, the polycondensation reaction is carried out while the dissolving agent is removed by distillation. In the presence of monomers with poor compatibility, the monomers with poor compatibility can be pre-condensed with the acid or alcohol to which they are to be polycondensed, and then polycondensed together with the main component.

[0124] Crystalline polyester resin

[0125] Examples of crystalline polyester resins include condensation polymers of polycarboxylic acids and polyols. It should be noted that commercially available products or synthetic compounds can be used as crystalline polyester resins.

[0126] Here, in order to facilitate the formation of a crystalline structure in the crystalline polyester resin, the crystalline polyester preferably uses a condensation polymer obtained from a linear aliphatic polymer, compared to a condensation polymer obtained using a polymer with aromatic polymers.

[0127] Examples of polycarboxylic acids include aliphatic dicarboxylic acids (such as oxalic acid, succinic acid, glutaric acid, adipic acid, octanoic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,18-octadecanedicarboxylic acid, etc.), aromatic dicarboxylic acids (such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, etc.), their anhydrides, or their lower (e.g., alkyl esters with 1 to 5 carbon atoms).

[0128] In polycarboxylic acids, dicarboxylic acids can be used in combination with carboxylic acids of three or more members that have a cross-linked or branched structure. Examples of tricarboxylic acids include aromatic carboxylic acids (e.g., 1,2,3-benzenetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, etc.), their anhydrides, or their lower (e.g., alkyl esters with 1 to 5 carbon atoms).

[0129] As polycarboxylic acids, these dicarboxylic acids can be used in combination with dicarboxylic acids having sulfonic acid groups or dicarboxylic acids having olefinic double bonds.

[0130] Polycarboxylic acids can be used alone or in combination of two or more.

[0131] Examples of polyols include aliphatic diols (e.g., straight-chain aliphatic diols with 7 to 20 carbon atoms in the main chain). Examples of aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, and 1,14-eicosenediol. Among these, 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol are preferred as aliphatic diols.

[0132] In polyols, diols can also be used in combination with alcohols of three or more members that have a cross-linked or branched structure. Examples of alcohols of three or more members include glycerol, trimethylolethane, trimethylolpropane, and pentaerythritol.

[0133] Polyols can be used alone or in combination of two or more.

[0134] Here, the content of aliphatic diols in the polyol is preferably 80 mol% or more, and more preferably 90 mol% or more.

[0135] The melting temperature of the crystalline polyester resin is preferably 50°C to 100°C, more preferably 55°C to 90°C, and even more preferably 60°C to 85°C.

[0136] It should be noted that the melting temperature is determined based on the DSC curve obtained by differential scanning calorimetry (DSC) according to the "melting peak temperature" recorded in the method for determining the melting temperature of plastics in JISK 7121:1987 "Method for determination of the transition temperature of plastics".

[0137] The weight-average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less.

[0138] Crystalline polyester resins are obtained, for example, by known manufacturing methods, similar to amorphous polyesters.

[0139] From the perspective of the abrasion resistance of the image, the weight-average molecular weight (Mw) of the adhesive resin is preferably 5,000 to 1,000,000, more preferably 7,000 to 500,000, and particularly preferably 25,000 to 60,000. The number-average molecular weight (Mn) of the adhesive resin is preferably 2,000 to 100,000. The molecular weight distribution Mw / Mn of the adhesive resin is preferably 1.5 to 100, more preferably 2 to 60.

[0140] The weight-average molecular weight and number-average molecular weight of the adhesive resin were determined by gel permeation chromatography (GPC). For the molecular weight determination using GPC, a Tosoh HLC-8120 GPC (manufactured by Tosoh Corporation) was used, along with a Tosoh TSKgel SuperHM-M (15 cm) column, and tetrahydrofuran (THF) solvent. The weight-average molecular weight and number-average molecular weight were calculated from the determination results using a molecular weight calibration curve prepared from monodisperse polystyrene standard samples.

[0141] The content of the adhesive resin relative to the total amount of resin particles is preferably 40% to 95% by mass, more preferably 50% to 90% by mass, and even more preferably 60% to 85% by mass.

[0142] -Other colorants besides the fluorescent colorants mentioned above-

[0143] Other colorants can be any colorants other than the fluorescent colorants mentioned above, and known colorants can be used.

[0144] Other colorants are preferably colorants that do not exhibit fluorescence in the visible light region.

[0145] In addition, other colorants can be pigments or dyes, with pigments being preferred.

[0146] Other colorants, specifically, include, for example, CI Pigment Red 1, CI Pigment Red 2, CI Pigment Red 3, CI Pigment Red 4, CI Pigment Red 5, CI Pigment Red 6, CI Pigment Red 7, CI Pigment Red 8, CI Pigment Red 9, CI Pigment Red 10, CI Pigment Red 11, CI Pigment Red 12, CI Pigment Red 14, CI Pigment Red 15, CI Pigment Red 16, CI Pigment Red 17, CI Pigment Red 18, CI Pigment Red 21, CI Pigment Red 22, CI Pigment Red 23, CI Pigment Red 31, CI Pigment Red 32, CI Pigment Red 38, CI Pigment Red 41, C CI Pigment Red 48, CI Pigment Red 48:1, CI Pigment Red 48:2, CI Pigment Red 48:3, CI Pigment Red 48:4, CI Pigment Red 49, CI Pigment Red 52, CI Pigment Red 53:1, CI Pigment Red 54, CI Pigment Red 57:1, CI Pigment Red 58, CI Pigment Red 60:1, CI Pigment Red 63, CI Pigment Red 64:1, CI Pigment Red 68, CI Pigment Red 81:1, CI Pigment Red 81:4, CI Pigment Red 83, CI Pigment Red 88, CI Pigment Red 89, CI Pigment Red 112, CI Pigment Red 114, CI Pigment Red 12 2. CI Pigment Red 123, CI Pigment Red 144, CI Pigment Red 146, CI Pigment Red 149, CI Pigment Red 150, CI Pigment Red 166, CI Pigment Red 170, CI Pigment Red 176, CI Pigment Red 177, CI Pigment Red 178, CI Pigment Red 179, CI Pigment Red 184, CI Pigment Red 185, CI Pigment Red 187, CI Pigment Red 202, CI Pigment Red 206, CI Pigment Red 207, CI Pigment Red 208, CI Pigment Red 209, CI Pigment Red 210, CI Pigment Red 220, CI Pigment Red 221, CI Pigment Red Pigment Red 238, CI Pigment Red 242, CI Pigment Red 245, CI Pigment Red 253, CI Pigment Red 254, CI Pigment Red 255, CI Pigment Red 256, CI Pigment Red 258, CI Pigment Red 264, CI Pigment Red 266, CI Pigment Red 269, CI Pigment Red 282, etc., Pigment Violet 19, etc., Magenta Pigment, CI Solvent Red 1, CI Solvent Red 3, CI Solvent Red 8, CI Solvent Red 23, CI Solvent Red 24, CI Solvent Red 25, CI Solvent Red 27, CI Solvent Red 30, CI Solvent Red 49, CI Solvent Red 52, CI Solvent Red 58, CI...Solvent Red 63, CI Solvent Red 81, CI Solvent Red 82, CI Solvent Red 83, CI Solvent Red 84, CI Solvent Red 100, CI Solvent Red 109, CI Solvent Red 111, CI Solvent Red 121, CI Solvent Red 122, CI Disperse Red 9, CI Basic Red 1, CI Basic Red 2, CI Basic Red 9, CI Basic Red 12, CI Basic Red 13, CI Basic Red 14, CI Basic Red 15, CI Basic Red 17, CI Basic Red 18, CI Basic Red 22, CI Basic Red 23, CI Basic Red 24, CI Basic Red 27, CI Basic Red 29, CI Basic Red 32, CI Basic Red 34, CI Basic Red 35, CI Basic Red 36, CI Basic Red 37, CI Basic Red 38, CI Basic Red 39, CI Basic Red 40, etc., magenta dyes, iron oxide red, cadmium red, lead red, mercury sulfide, permanent red 4R, lithochrome red, pyrazolone red, Huaqiong red, calcium salts, lake red D, bright carmine 6B, eosin lake, rhodamine lake B, alizarin lake, bright carmine 3B, carbon black, chrome yellow, Hansa yellow, benzidine yellow, vat yellow, quinoline yellow, pigment yellow, permanent orange GTR, pyrazolone orange, sulfur-resistant orange, bright carmine 3B, bright carmine 6B, DuPont oil red, lake red C, aniline blue, cyan blue, oil-soluble blue, methylene blue chloride, phthalocyanine blue, pigment blue, phthalocyanine green, malachite green oxalate, and various other pigments or dyes. Additionally, it is suitable for solid solution pigments (pigments whose crystal structure is changed by solidifying two or more pigments). Specifically, combinations of different substituents in quinacridones (such as unsubstituted quinacridones PV19 and PR122, PV19 and PR202, etc.) can be cited as examples.

[0147] Other colorants can be appropriately selected based on the desired color. For example, in cases where a fluorescent pink is desired, a colorant containing magenta can be used. Solid solution pigments are suitable in this case. As a fluorescent color, good performance is achieved if the same hue produces either a bright or dark color; the performance tends to be improved by using solid solution pigments.

[0148] Other colorants can be used alone or in combination of two or more.

[0149] Other colorants can be surface-treated as needed, or they can be used in combination with dispersants. Furthermore, two or more colorants can be used together.

[0150] The content of other colorants, from the perspective of fluorescence intensity and image graininess, is preferably 2% by mass or less, more preferably 1.5% by mass or less, and particularly preferably 1% by mass or less, relative to the total amount of resin particles.

[0151] From the perspective of fluorescence intensity and image graininess, the ratio of the content of fluorescent colorant WA in the resin particles to the content of other colorants WB (WB / WA) is preferably 1.25 or less, more preferably 1.0 or less, and particularly preferably 0.5 or less.

[0152] -Release agent-

[0153] Examples of release agents include: hydrocarbon waxes; natural waxes such as carnauba wax, rice bran wax, and candelilla wax; synthetic or mineral / petroleum-based waxes such as lignite wax; ester-based waxes such as fatty acid esters and lignite esters; and so on. Release agents are not limited to these.

[0154] The melting temperature of the release agent is preferably 50°C to 110°C, more preferably 60°C to 100°C.

[0155] The melting temperature is determined by the "melting peak temperature" as described in the method for determining the melting temperature in JIS K7121-1987 "Method for determination of the transition temperature of plastics" based on the DSC curve obtained by differential scanning calorimetry (DSC).

[0156] The content of the release agent relative to the total amount of resin particles is preferably 1% to 20% by mass, more preferably 5% to 15% by mass.

[0157] -Other Additives-

[0158] Other additives include, for example, known additives such as magnetic materials, charge control agents, and inorganic powders. These additives can be included as internal additives in resin particles.

[0159] -Properties of resin particles, etc.-

[0160] The resin particles can be single-layered resin particles or so-called core / shell structure resin particles (core / shell type particles) consisting of a core (core particle) and a coating layer (shell layer) covering the core. Core / shell structured resin particles can, for example, consist of a core and a coating layer, wherein the core contains an adhesive resin, a fluorescent colorant, and other colorants and release agents, if necessary, and the coating layer contains an adhesive resin.

[0161] The volume average particle size (D) of the resin particles 50v The preferred size is 2μm or more and 10μm or less, and more preferably 4μm or more and 8μm or less.

[0162] The volume average particle size of the resin particles was determined using a Coulter Multisizer II (manufactured by Beckman Coulter), and the electrolyte was determined using an ISOTON-II (manufactured by Beckman Coulter).

[0163] During the determination, 0.5 mg to 50 mg of the test sample is added to 2 ml of a 5% aqueous solution of the surfactant (preferably sodium alkylbenzene sulfonate) as a dispersant. This is then added to 100 ml to 150 ml of electrolyte.

[0164] The electrolyte containing the suspended sample was dispersed using an ultrasonic disperser for 1 minute. Particle sizes ranging from 2 μm to 60 μm were measured using a Coulter Multisizer II with 100 μm pores. A total of 50,000 particles were sampled.

[0165] For the measured particle size, the cumulative distribution of the volume reference is plotted from the smaller diameter side, and the particle size at the 50% cumulative point is defined as the volume average particle size D. 50v .

[0166] In this embodiment, the average roundness of the resin particles is not particularly limited. From the perspective of ensuring good cleanliness of the image holder, it is preferably 0.91 or more and 0.98 or less, more preferably 0.94 or more and 0.98 or less, and even more preferably 0.95 or more and 0.97 or less.

[0167] In this embodiment, the roundness of the resin particles is defined as (circumference of a circle with the same area as the particle projection image) ÷ (circumference of the particle projection image). The average roundness of the resin particles is defined as the roundness of the 50% of points accumulated from the smallest roundness side in the roundness distribution. The average roundness of the resin particles is determined by analyzing at least 3,000 resin particles using a flow cytometry particle image analysis device.

[0168] Regarding the average roundness of resin particles, for example in the case of manufacturing resin particles by agglomeration and merging, it can be controlled by adjusting the stirring speed of the dispersion, the temperature of the dispersion, or the holding time in the fusion / merging step.

[0169] (Additives)

[0170] When resin particles are used as toners for electrostatic image development (described later), the resin particles may contain additives as needed.

[0171] In addition, the resin particles can be resin particles without additives, or they can be resin particles with additives.

[0172] Examples of additives include inorganic particles. Examples of such inorganic particles include SiO2, TiO2, Al2O3, CuO, ZnO, SnO2, CeO2, Fe2O3, MgO, BaO, CaO, K2O, Na2O, ZrO2, CaO·SiO2, and K2O·(TiO2). n Al2O3·2SiO2, CaCO3, MgCO3, BaSO4, MgSO4, etc.

[0173] The surface of inorganic particles used as additives can also be hydrophobically treated. Hydrophobic treatment can be performed, for example, by impregnating the inorganic particles with a hydrophobic agent. There are no particular limitations on the hydrophobic agent; examples include silane-based coupling agents, silicone oils, titanate-based coupling agents, and aluminum-based coupling agents. These agents can be used alone or in combination of two or more.

[0174] The amount of the hydrophobic treatment agent is preferably 1 part to 10 parts by mass relative to 100 parts by mass of inorganic particles.

[0175] Other examples of additives include resin particles (such as polystyrene, polymethyl methacrylate (PMMA), and melamine resin particles) and cleaning surfactants (such as metal salts of higher fatty acids, such as zinc stearate, and particles of fluorinated high molecular weight compounds).

[0176] The amount of additive used as an external additive is preferably 0.01% to 10% by mass and more preferably 0.01% to 6% by mass relative to the resin particles.

[0177] <Uses of Resin Granules>

[0178] The resin particles of this embodiment are suitable for use as resin particles for image forming, and are even more suitable for use as toners for electrostatic image development.

[0179] Furthermore, the resin particles of this embodiment are also suitable for use as powder coatings. They can also be used to coat the surface to be coated, and then heated (calcined) to form a coating film that solidifies the powder, thereby manufacturing coated products. In this case, coating and heating (calcining) can be performed simultaneously.

[0180] Powder coating can be achieved using known coating methods such as spray coating, electrostatic powder coating, triboelectric powder coating, and flow impregnation. The thickness of the powder coating film is preferably, for example, 30 μm or more and 50 μm or less.

[0181] The heating temperature (calcination temperature) is preferably 90°C to 250°C, more preferably 100°C to 220°C, and even more preferably 120°C to 200°C. It should be noted that the heating time (calcination time) is adjusted by the heating temperature (calcination temperature).

[0182] There are no particular limitations on the objects to be coated with powder; various metal parts, ceramic parts, resin parts, etc., can be included. These objects can be unformed products before being molded into sheet-like or wire-like products, or molded products for use in electronic components, road vehicles, or interior and exterior building decoration materials. In addition, objects can be products whose surfaces have been pre-treated with an undercoat, plated, or electrodeposited.

[0183] In addition, the resin particles of this embodiment are also suitable for use as resin particles for colorant displays in fields other than coating.

[0184] Toner displays, which disperse charged resin particles in a medium (mostly air) and display images by moving the resin particles under the influence of an electric field, are well-known. The resin particles of this embodiment can also be used without problems in this manner. For example, resin particles are placed in a cell held by two transparent electrodes, and a voltage is applied to move the resin particles, thereby displaying an image.

[0185] [Method for manufacturing resin particles]

[0186] Next, the method for manufacturing the resin particles according to this embodiment will be described.

[0187] In this embodiment, the resin particles can be supplemented with an additive after the resin particles are manufactured.

[0188] Resin particles can be manufactured using any of the following methods: dry methods (e.g., mixing and pulverizing) and wet methods (e.g., agglomeration and aggregation (agglomeration-1), suspension polymerization, dissolution suspension polymerization, etc.). There are no particular limitations on these methods, and well-known methods can be used. Among these, agglomeration and aggregation is preferred for obtaining resin particles.

[0189] As a method of aggregation and merging, examples include the methods described in Japanese Patent Application Publication No. 2010-97101 or Japanese Patent Application Publication No. 2006-154641.

[0190] As a method of mixing and pulverizing, for example, the method described in Japanese Patent Application Publication No. 2000-267338 can be cited.

[0191] As a dissolution and suspension method, the method described in Japanese Patent Application Publication No. 2000-258950 can be cited as an example.

[0192] In the method for manufacturing resin particles, when using a fluorescent colorant with anionic groups and an adhesive resin with cationic groups, a surfactant with cationic groups is preferred from the perspective of fluorescence intensity and image graininess. Furthermore, a polymerization initiator with cationic groups is preferred in the polymerization of the adhesive resin with cationic groups.

[0193] Furthermore, in the method for manufacturing resin particles, when using a fluorescent colorant with cationic groups and an adhesive resin with anionic groups, a surfactant with anionic groups is preferred from the perspective of fluorescence intensity and image graininess. Additionally, a polymerization initiator with anionic groups is preferred in the polymerization of the adhesive resin with anionic groups.

[0194] As a surfactant with a cationic group, a cationic surfactant with an ammonium group is preferred, and a cationic surfactant with a quaternary ammonium group is more preferred.

[0195] As a polymerization initiator with cationic groups, polymerization initiators with amino or amidine groups are preferred, polymerization initiators with amidine groups are more preferred, and azo polymerization initiators with amidine groups are particularly preferred.

[0196] As a surfactant having anionic groups, anionic surfactants having sulfonyl, sulfate ester or salt thereof are preferred, and anionic surfactants having sulfonyl or salt thereof are more preferred.

[0197] As a polymerization initiator with anionic groups, persulfate compounds are preferred, and ammonium persulfate, potassium persulfate, or sodium persulfate are more preferred.

[0198] In addition, specifically, for example, in the case of manufacturing resin particles by agglomeration and merging, the resin particles are manufactured by the following steps: preparing a resin particle dispersion in which resin particles as a binding resin are dispersed (resin particle dispersion preparation step); agglomerating the resin particles (and other particles if necessary) in the resin particle dispersion (or in the dispersion after mixing with other particle dispersions if necessary) to form agglomerated particles (agglomerated particle forming step); and heating the agglomerated particle dispersion in which the agglomerated particles are dispersed to fuse / merge (fusion / union) the agglomerated particles to form resin particles (fusion / merging step).

[0199] The following details each step.

[0200] The following description explains a method for obtaining resin particles containing other colorants and release agents, but these other colorants and release agents are components used as needed. Of course, other additives besides colorants and release agents can also be used.

[0201] -Preparation steps for resin particle dispersion-

[0202] Prepare a resin particle dispersion containing resin particles as an adhesive resin, and simultaneously prepare, for example, a colorant particle dispersion containing other colorant particles and a release agent particle dispersion containing release agent particles.

[0203] Resin particle dispersions are prepared, for example, by dispersing resin particles in a dispersion medium using a surfactant.

[0204] Examples of dispersion media used in resin particle dispersions include aqueous media.

[0205] Examples of aqueous media include distilled water, ion-exchanged water, and alcohols. These media can be used individually or in combination.

[0206] Examples of surfactants include: anionic surfactants such as sulfate esters, sulfonates, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyols. Among these, anionic and cationic surfactants are particularly noteworthy. Nonionic surfactants can also be used in combination with anionic or cationic surfactants.

[0207] Among these, nonionic surfactants are preferred, and nonionic surfactants are preferably used in combination with anionic or cationic surfactants.

[0208] Furthermore, as described above, in the method for manufacturing resin particles, when using a fluorescent colorant with anionic groups and an adhesive resin with cationic groups, from the perspective of fluorescence intensity and image graininess, it is preferable to use a surfactant with cationic groups. On the other hand, in the method for manufacturing resin particles, when using a fluorescent colorant with cationic groups and an adhesive resin with anionic groups, from the perspective of fluorescence intensity and image graininess, it is preferable to use a surfactant with anionic groups.

[0209] Surfactants can be used alone or in combination of two or more.

[0210] In resin particle dispersions, common methods for dispersing resin particles in a dispersion medium include using a rotary shear homogenizer or a ball mill, sand mill, or bead mill with a media. Alternatively, depending on the type of resin particles, phase inversion emulsification can also be used. Phase inversion emulsification involves dissolving the resin to be dispersed in a hydrophobic organic solvent capable of dissolving the resin, adding an alkali to the organic continuous phase (O phase) for neutralization, and then introducing an aqueous medium (W phase). This results in a phase inversion from W / O to O / W, dispersing the resin in particulate form in the aqueous medium.

[0211] The volume average particle size of the resin particles dispersed in the resin particle dispersion is preferably 0.01 μm or more and 1 μm or less, more preferably 0.08 μm or more and 0.8 μm or less, and even more preferably 0.1 μm or more and 0.6 μm or less.

[0212] Regarding the volume average particle size of resin particles, the particle size distribution obtained by laser diffraction particle size distribution measuring device (e.g., Horiba Manufacturing Co., Ltd. LA-700) was used. For the divided particle size range (segment), a cumulative distribution was plotted from the smallest particle size side with respect to volume, and the particle size at the cumulative 50% point relative to all particles was measured and taken as the volume average particle size D50v. The volume average particle size of particles in other dispersions was also measured in the same way.

[0213] The resin particle dispersion contains preferably 5% by mass or more and 50% by mass or less, more preferably 10% by mass or more and 40% by mass or less.

[0214] -Steps in chemical bonding formation-

[0215] Furthermore, in the method for manufacturing resin particles according to this embodiment, it is preferable to include a step of chemically bonding a fluorescent colorant having groups capable of reacting or interacting with the aforementioned chemically bondable groups to the surface of the resin particles having chemically bondable groups, and more preferably to include a step of ionically bonding a fluorescent colorant having ionic groups to the surface of the resin particles having ionic groups.

[0216] More specifically, for example, a step of ion bonding a fluorescent colorant with cationic groups to the surface of resin particles having anionic groups, or a step of ion bonding a fluorescent colorant with anionic groups to the surface of resin particles having cationic groups.

[0217] In addition, unless otherwise stated, in the following description, resin particles are resin particles with fluorescent colorants chemically bonded or resin particles with fluorescent colorants dispersed at the molecular level.

[0218] Similar to resin particle dispersions, other colorant particle dispersions and release agent particle dispersions are also prepared. That is, the same conditions apply to the volume average particle size, dispersion medium, dispersion method, and particle content in resin particle dispersions as to the colorant particles dispersed in other colorant particle dispersions and the release agent particles dispersed in release agent particle dispersions.

[0219] -Steps in the formation of aggregated particles-

[0220] Next, the resin particle dispersion, other colorant particle dispersion, and release agent particle dispersion are mixed.

[0221] Subsequently, the resin particles, other colorant particles, and release agent particles are heterogeneously aggregated in the mixed dispersion to form aggregated particles with a diameter similar to that of the target resin particles and containing resin particles, other colorant particles, and release agent particles.

[0222] Specifically, for example, a flocculant is added to the mixed dispersion, and the pH of the mixed dispersion is adjusted to acidic (e.g., pH 2 or higher than 5). A dispersing stabilizer is added as needed, and then the mixture is heated to a temperature close to the glass transition temperature of the resin particles (specifically, for example, the glass transition temperature of the resin particles -30°C to -10°C), causing the particles dispersed in the mixed dispersion to agglomerate and form aggregated particles.

[0223] In the step of forming aggregated particles, for example, a coagulant can be added at room temperature (e.g., 25°C) while the mixed dispersion is stirred using a rotary shear homogenizer, the pH of the mixed dispersion is adjusted to acidic (e.g., pH 2 or higher than 5), a dispersion stabilizer is added as needed, and then the mixture is heated.

[0224] Examples of flocculants include surfactants with polarity opposite to that of the surfactant contained in the mixed dispersion, inorganic metal salts, and metal complexes with a polarity of two or higher. When metal complexes are used as flocculants, the amount of surfactant required is reduced, and the charging characteristics are improved.

[0225] Additives that form complexes or similar bonds with the metal ions of the flocculant can be used as needed. Chelating agents are suitable as such additives.

[0226] Examples of inorganic metal salts include calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, and calcium polysulfide; and so on.

[0227] Water-soluble chelating agents can be used as chelating agents. Examples of chelating agents include hydroxycarboxylic acids such as tartaric acid, citric acid, and gluconic acid; aminocarboxylic acids such as iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), and ethylenediaminetetraacetic acid (EDTA); and so on.

[0228] The amount of coagulant added relative to 100 parts by weight of resin particles is preferably 0.01 parts by weight or more and 5.0 parts by weight or less, more preferably 0.1 parts by weight or more and less than 3.0 parts by weight.

[0229] -Merge / merge steps-

[0230] Next, the dispersion of agglomerated particles containing the agglomerated particles is heated to, for example, above the glass transition temperature of the resin particles (e.g., above a temperature 30°C to 50°C higher than the glass transition temperature of the resin particles) and above the melting temperature of the release agent, so that the agglomerated particles fuse / merge to form resin particles.

[0231] In the fusion / merging step, the resin and release agent are fused together above the glass transition temperature of the resin particles and above the melting temperature of the release agent. Cooling is then performed to obtain resin particles.

[0232] As a method to adjust the aspect ratio of the release agent in resin particles, crystal growth can be promoted by maintaining the temperature near the solidification point of the release agent for a certain period of time during cooling, or by using two or more release agents with different melting temperatures, thereby adjusting the aspect ratio.

[0233] After the above steps, resin particles are obtained.

[0234] After obtaining the agglomerated particle dispersion containing agglomerated particles, resin particles can be manufactured by the following steps: further mixing the above agglomerated particle dispersion with the resin particle dispersion containing resin particles, and agglomerating the resin particles in a manner that further adheres them to the surface of the agglomerated particles to form second agglomerated particles; and heating the second agglomerated particle dispersion containing the second agglomerated particles to fuse / merge the second agglomerated particles to form core / shell structured resin particles.

[0235] After the fusion / merging step, the resin particles formed in the solution are subjected to known washing, solid-liquid separation, and drying steps to obtain dried resin particles. Regarding the washing step, from a power efficiency perspective, displacement washing using ion-exchanged water can be fully implemented. Regarding the solid-liquid separation step, from a productivity perspective, methods such as vacuum filtration and pressure filtration can be implemented. Regarding the drying step, from a productivity perspective, methods such as freeze drying, airflow drying, fluidized bed drying, and vibrating fluidized bed drying can be implemented.

[0236] Subsequently, when using the resin particles of this embodiment as a toner for electrostatic image development, for example, an additive is added to the obtained dried resin particles and mixed to produce the toner. Mixing can be performed using, for example, a V-type mixer, a Henschel mixer, or a Loedige mixer.

[0237] Furthermore, vibrating screens, pneumatic screens, and other equipment can be used as needed to remove coarse resin particles.

[0238] <Electrostatic Image Developer>

[0239] When the resin particles of this embodiment are used as an electrostatic image developer, it can be a single-component developer containing only the resin particles of this embodiment, or it can be a two-component developer formed by mixing the resin particles with a carrier.

[0240] There are no particular limitations on the carrier, and known carriers can be cited. Examples of carriers include: a coated carrier in which resin is coated on the surface of a core material formed of magnetic powder; a magnetic powder dispersion carrier in which magnetic powder is dispersed and mixed in a matrix resin; a resin-impregnated carrier formed by impregnating resin in porous magnetic powder; and so on. Magnetic powder dispersion carriers and resin-impregnated carriers can also be carriers in which the constituent particles of the carrier are used as the core material and their surfaces are coated with resin.

[0241] Examples of magnetic powders include: magnetic metals such as iron, nickel, and cobalt; magnetic oxides such as ferrite and magnetite; and so on.

[0242] Examples of resins used for coating and matrix resins include polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, vinyl chloride-vinyl acetate copolymer, styrene-acrylate copolymer, pure silicone resins or their modifications comprising organosiloxane bonds, fluoropolymers, polyesters, polycarbonates, phenolic resins, and epoxy resins. The coating resin and matrix resin may contain additives such as conductive particles. Examples of conductive particles include metals such as gold, silver, and copper, carbon black, titanium dioxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, and potassium titanate.

[0243] From the perspective of suppressing concentration unevenness in the obtained image, it is preferable to use a carrier with a surface coated with a resin containing an organosilicon resin, and more preferably a carrier with a surface coated with an organosilicon resin.

[0244] When using resin to coat the surface of a core material, methods such as coating with a coating layer forming solution prepared by dissolving the resin to be coated and various additives (used as needed) in a suitable solvent can be employed. There are no particular limitations on the solvent; it can be selected considering the type of resin used and its coating suitability. Specific resin coating methods include: impregnation, in which the core material is immersed in the coating layer forming solution; spraying, in which the coating layer forming solution is sprayed onto the surface of the core material; fluidized bed method, in which the coating layer forming solution is sprayed while the core material is suspended by flowing air; kneading coating machine method, in which the core material of the carrier is mixed with the coating layer forming solution in a kneading coating machine, and then the solvent is removed; and so on.

[0245] The mixing ratio (mass ratio) of resin particles (toner for electrostatic image development) to carrier in the two-component developer is preferably resin particles (toner for electrostatic image development): carrier = 1:100 to 30:100, more preferably 3:100 to 20:100.

[0246] <Image forming apparatus, image forming method>

[0247] An image forming apparatus / image forming method will be described in the case where the resin particles of this embodiment are used as a toner for electrostatic image development.

[0248] The image forming apparatus includes: an image holder; a charging mechanism for charging the surface of the image holder; an electrostatic image forming mechanism for forming an electrostatic image on the charged surface of the image holder; a developing mechanism for storing an electrostatic image developer and developing the electrostatic image formed on the surface of the image holder into a toner image using the electrostatic image developer; a transfer mechanism for transferring the toner image formed on the surface of the image holder to the surface of a recording medium; and a fixing mechanism for fixing the toner image transferred to the surface of the recording medium. Furthermore, an electrostatic image developer comprising the resin particles of this embodiment is used as the electrostatic image developer.

[0249] An image forming method comprising the following steps is performed in an image forming apparatus: a charging step, wherein the surface of an image holder is charged; an electrostatic image forming step, wherein an electrostatic image is formed on the charged surface of the image holder; a developing step, wherein the electrostatic image formed on the surface of the image holder is developed into a toner image using an electrostatic image developer containing resin particles of the present embodiment; a transfer step, wherein the toner image formed on the surface of the image holder is transferred to the surface of a recording medium; and a fixing step, wherein the toner image transferred to the surface of the recording medium is fixed.

[0250] As an image forming apparatus, the following known image forming apparatuses can be used: a direct transfer method apparatus that directly transfers a toner image formed on the surface of an image holder to a recording medium; an intermediate transfer method apparatus that transfers a toner image formed on the surface of an image holder to the surface of an intermediate transfer body in one step, and then transfers the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium in a second step; an apparatus equipped with a cleaning mechanism for cleaning the surface of the image holder after the toner image is transferred and before charging; an apparatus equipped with a de-energizing mechanism for irradiating the surface of the image holder with de-energizing light to de-energize it after the toner image is transferred and before charging; and so on.

[0251] When the image forming apparatus is an intermediate transfer apparatus, the applied transfer mechanism may have, for example, the following components: an intermediate transfer body that transfers a toner image to a surface; a primary transfer mechanism that transfers a toner image formed on the surface of an image holder to the surface of the intermediate transfer body in one step; and a secondary transfer mechanism that transfers the toner image transferred to the surface of the intermediate transfer body to the surface of a recording medium in a second step.

[0252] In an image forming apparatus, the portion including the developing mechanism may be a cartridge structure (processing cartridge) that is loaded and unloaded within the image forming apparatus. For example, a processing cartridge equipped with a developing mechanism that stores an electrostatic image developer containing resin particles from this embodiment is suitable as a processing cartridge.

[0253] An example of an image forming apparatus will be described below, but the description is not limited to this. In the following description, the main parts shown in the figures will be explained. Other descriptions are omitted.

[0254] Figure 1 A schematic configuration diagram of the image forming apparatus used in this embodiment is shown.

[0255] Figure 1 The image forming apparatus shown includes first to fourth image forming units 10Y, 10M, 10C, and 10K (image forming mechanisms) of an electrophotographic method that outputs images of yellow (Y), magenta (M), cyan (C), and black (K) based on color image data. These image forming units (hereinafter also referred to as "units") 10Y, 10M, 10C, and 10K are arranged side-by-side at a predetermined distance from each other in the horizontal direction. These units 10Y, 10M, 10C, and 10K can be processing boxes that are mounted and detached from the image forming apparatus.

[0256] Above each of units 10Y, 10M, 10C, and 10K, an intermediate transfer belt (an example of an intermediate transfer body) 20 extends through each unit. The intermediate transfer belt 20 is wound around a drive roller 22 and a support roller 24, which are in contact with the inner surface of the intermediate transfer belt 20, causing it to move in a direction from the first unit 10Y towards the fourth unit 10K. The support roller 24 applies force in a direction separate from the drive roller 22 via a spring (not shown), applying tension to the intermediate transfer belt 20 wound around both rollers. An intermediate transfer belt cleaning device 30, opposite the drive roller 22, is provided on the image holding surface side of the intermediate transfer belt 20.

[0257] The yellow, magenta, cyan, and black toners stored in the toner cartridges 8Y, 8M, 8C, and 8K are supplied to the developing apparatus (an example of a developing mechanism) 4Y, 4M, 4C, and 4K of each unit 10Y, 10M, 10C, and 10K, respectively.

[0258] Units 1 through 4, 10Y, 10M, 10C, and 10K, have the same configuration and operation. Therefore, the first unit 10Y, which forms the yellow image and is located on the upstream side of the intermediate transfer belt in the direction of travel, will be used as an example for explanation.

[0259] Unit 10Y has a photoreceptor 1Y that functions as an image holder. Around the photoreceptor 1Y are arranged in sequence: a charging roller (an example of a charging mechanism) 2Y, which charges the surface of the photoreceptor 1Y to a preset potential; an exposure device (an example of an electrostatic image forming mechanism) 3, which uses a laser line 3Y to expose the charged surface based on a color separation image signal to form an electrostatic image; a developing device (an example of a developing mechanism) 4Y, which supplies the charged toner to the electrostatic image to develop the electrostatic image; a primary transfer roller (an example of a primary transfer mechanism) 5Y, which transfers the developed toner image onto an intermediate transfer belt 20; and a photoreceptor cleaning device (an example of an image holder cleaning mechanism) 6Y, which removes the toner remaining on the surface of the photoreceptor 1Y after the primary transfer.

[0260] The primary transfer roller 5Y is positioned inside the intermediate transfer belt 20, opposite to the photosensitive element 1Y. Each unit's primary transfer rollers 5Y, 5M, 5C, and 5K are connected to a bias power supply (not shown) that applies a primary transfer bias voltage. The bias power supply changes the value of the transfer bias voltage applied to each primary transfer roller via a control unit (not shown).

[0261] The following explains the action of forming the yellow image in Unit 1, 10Y.

[0262] First, before the operation, the surface of the photoreceptor 1Y is charged to a potential of -600V to -800V using the charging roller 2Y.

[0263] Photoreceptor 1Y has good electrical conductivity (e.g., a volume resistivity of 1×10⁻⁶ at 20°C). -6 A photosensitive layer is deposited on a substrate (Ωcm or less). This photosensitive layer typically has high resistance (the resistance of common resins), but it has the property that the resistivity of the portion irradiated by the laser line changes when the laser line is irradiated. Therefore, based on yellow image data sent from a control unit (not shown), the laser line 3Y is irradiated by the exposure device 3 onto the surface of the charged photoreceptor 1Y. As a result, an electrostatic image of a yellow image pattern is formed on the surface of the photoreceptor 1Y.

[0264] An electrostatic image is an image formed on the surface of a photoreceptor 1Y by charging. It is a so-called negative latent image, which is formed as follows: the resistivity of the irradiated part of the photosensitive layer is reduced by using a laser line 3Y, causing the charged charge on the surface of the photoreceptor 1Y to flow; on the other hand, the charge remains in the part that is not irradiated by the laser line 3Y, thereby forming the negative latent image.

[0265] The electrostatic image formed on the photoreceptor 1Y rotates to a predetermined developing position as the photoreceptor 1Y rotates. At this developing position, the electrostatic image on the photoreceptor 1Y is developed into a toner image by the developing device 4Y and then visualized.

[0266] The developing apparatus 4Y stores an electrostatic image developer, for example, containing at least a yellow toner and a carrier. The yellow toner, inside the developing apparatus 4Y, becomes triboelectrically charged through agitation, acquiring a charge of the same polarity (negative polarity) as the charge on the photoreceptor 1Y, and is held on a developer roller (an example of a developer holder). The surface of the photoreceptor 1Y then passes through the developing apparatus 4Y, whereby the yellow toner electrostatically adheres to the de-charged latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed using the yellow toner. The photoreceptor 1Y, with the yellow toner image formed, continues to rotate at a preset speed, conveying the developed toner image on the photoreceptor 1Y to a preset primary transfer position.

[0267] When the yellow toner image on the photoreceptor 1Y is transferred to the primary transfer position, a primary transfer bias is applied to the primary transfer roller 5Y. The electrostatic force from the photoreceptor 1Y toward the primary transfer roller 5Y acts on the toner image, transferring the toner image from the photoreceptor 1Y onto the intermediate transfer belt 20. The applied transfer bias has a polarity opposite to the toner's polarity (-), and is controlled, for example, to +10 μA in the first unit 10Y by a control unit (not shown). The toner remaining on the photoreceptor 1Y is removed and recovered using the photoreceptor cleaning device 6Y.

[0268] The primary transfer bias applied to the primary transfer rollers 5M, 5C, and 5K after 10M in Unit 2 is also controlled according to Unit 1.

[0269] In this way, the intermediate transfer belt 20, which has transferred the yellow toner image using the first unit 10Y, is sequentially transmitted through the second to fourth units 10M, 10C, and 10K, so that the toner images of each color are transferred in a superimposed manner.

[0270] The intermediate transfer belt 20, which has undergone multiple transfer of four toner images via units 1 to 4, reaches the secondary transfer section. This secondary transfer section comprises the intermediate transfer belt 20, a support roller 24 in contact with the inner surface of the intermediate transfer belt, and a secondary transfer roller (an example of a secondary transfer mechanism) 26 disposed on the image holding side of the intermediate transfer belt 20. Meanwhile, recording paper (an example of a recording medium) P is fed to the gap between the secondary transfer roller 26 and the intermediate transfer belt 20 at a predetermined time by a supply member, and a secondary transfer bias is applied to the support roller 24. The applied transfer bias has the same polarity (-) as the toner, and the electrostatic force from the intermediate transfer belt 20 toward the recording paper P acts on the toner image, transferring the toner image from the intermediate transfer belt 20 onto the recording paper P. The secondary transfer bias is determined based on the resistance detected by a resistance detection mechanism (not shown) that detects the resistance of the secondary transfer section, and the voltage is controlled accordingly.

[0271] The recording paper P, on which the toner image has been transferred, is fed into the pressing section (engaging section) of a pair of fixing rollers in the fixing device (an example of a fixing mechanism) 28, fixing the toner image onto the recording paper P to form a fixed image. The recording paper P, now with the color image fixed, is then sent to the ejection section, ending a series of color image forming operations.

[0272] Recording paper P used for transferring toner images can be, for example, ordinary paper used in photocopiers and printers using electrophotographic methods. Besides recording paper P, other recording media include OHP transparent film. To further improve the smoothness of the image surface after fixing, it is preferable that the surface of the recording paper P is also smooth; for example, coated paper or art paper for printing, which is obtained by coating the surface of ordinary paper with resin, is suitable.

[0273] <Processing box, colorant box>

[0274] When the resin particles of this embodiment are used as an electrostatic image developer, the processing cartridge is a processing cartridge that is loaded and unloaded in an image forming apparatus. It has a developing mechanism that stores an electrostatic image developer containing the resin particles of this embodiment, and uses the electrostatic image developer to develop the electrostatic image formed on the surface of the image holder into a toner image.

[0275] The processing box may be configured to include a developing mechanism, and, if necessary, at least one of other mechanisms selected from an image holder, a charging mechanism, an electrostatic image forming mechanism, and a transfer mechanism.

[0276] The following shows an example of a processing box, but is not limited to it. In the following description, the main parts shown in the figure will be described, and other descriptions will be omitted.

[0277] Figure 2 This is a schematic configuration diagram illustrating an example of the processing box used in this embodiment.

[0278] Figure 2 The processing cartridge 200 shown is constructed, for example, by integrating and holding the photosensitive element 107 (an example of an image holder) with the charging roller 108 (an example of a charging mechanism), the developing device 111 (an example of a developing mechanism), and the photosensitive element cleaning device 113 (an example of a cleaning mechanism) around the photosensitive element 107 in a housing 117 having a mounting rail 116 and an opening 118 for exposure, thus forming an ink cartridge.

[0279] Figure 2 In the diagram, 109 represents an exposure device (an example of an electrostatic image forming mechanism), 112 represents a transfer device (an example of a transfer mechanism), 115 represents a fixing device (an example of a fixing mechanism), and 300 represents recording paper (an example of a recording medium).

[0280] Next, the colorant box will be explained.

[0281] The toner cartridge is a cartridge that stores the resin particles of this embodiment as a toner for electrostatic image development and is loaded and unloaded in the image forming apparatus. The toner cartridge stores replenishment toner for supplying to the developing unit provided in the image forming apparatus.

[0282] Figure 1 The image forming apparatus shown is configured with toner cartridges 8Y, 8M, 8C, and 8K for loading and unloading. The developing units 4Y, 4M, 4C, and 4K are connected to the toner cartridges corresponding to each color via toner supply tubes (not shown). Furthermore, if the toner stored in a cartridge is insufficient, the cartridge is replaced.

[0283] [Example]

[0284] The following describes embodiments of the present invention, but the present invention is not limited to the following embodiments. It should be noted that, unless otherwise stated, "parts" and "%" in the following description refer to mass.

[0285] (Example 1)

[0286] <Preparation of Adhesive Resin Particle Dispersion (1): An Example of Preparing Cationic Particles Based on Emulsion Polymerization>

[0287] • Styrene (manufactured by Wako Pure Chemical Industries, Ltd.): 80.0 parts

[0288] • Dimethylaminoethyl acrylate (manufactured by Tokyo Chemical Industry Co., Ltd.): 20.0 parts

[0289] • Cationic surfactant (Kao Corporation, Quartamin 86W): 3.6 parts

[0290] • Cationic polymerization initiator (manufactured by Wako Pure Chemical Industries, Ltd., VA-50): 1.0 part

[0291] ·DIW: 397 copies

[0292] The above materials were mixed in a flask and emulsified for 10 minutes using a homogenizer (ULTRA-TURRAX T50, manufactured by IKA). Next, after purging the flask with nitrogen, the solution was heated to 85°C in a water bath with stirring. Emulsion polymerization was carried out under these conditions for 5 hours, followed by cooling to 30°C to obtain a cationic resin particle dispersion (1) with a solid content concentration of 20% by mass. An adhesive resin particle dispersion (1) with an average particle size of 130 nm was also obtained.

[0293] <Preparation of a dispersion of resin particles with ion-bonded fluorescent colorants (1)>

[0294] • Adhesive resin particle dispersion (1): 475 parts

[0295] • Anionic fluorescent colorant (Tokyo Chemical Industry Co., Ltd., Acid Red 52): 5 parts

[0296] The above materials were mixed and the pH was adjusted to 4.5. The mixture was then stirred at 60°C for 1 hour. The concentration of the solid component was adjusted to 20% by mass to obtain a fluorescent colorant particle dispersion (1).

[0297] <Preparation of release agent particle dispersion (1)>

[0298] • Solid paraffin wax (manufactured by Nippon Seika Co., Ltd., HNP-9): 100 parts

[0299] • Anionic surfactant (manufactured by Daiichi Kogyo Co., Ltd., NEOGEN RK): 1 part

[0300] • Ion-exchanged water: 350 parts

[0301] The above materials were mixed and heated to 100°C. After dispersion using a homogenizer (IKA, trade name ULTRA-TURRAX T50), the dispersion was further processed using a Manton Gaulin high-pressure homogenizer (Gaulin) to obtain a release agent particle dispersion (1) containing release agent particles with a volume average particle size of 200 nm (solid content 20% by mass).

[0302] <Preparation of Toning Agent Particles (1)>

[0303] Fluorescent colorant particle dispersion (1): 450 parts

[0304] • Release agent particle dispersion (1): 50 parts

[0305] • Anionic surfactant (NEOGEN RK, 20%, manufactured by Daiichi Kogyo Co., Ltd.): 10 parts

[0306] The above materials were placed in a round stainless steel flask, and the pH was adjusted to 3.5 by adding 0.1N (mol / L) nitric acid. Then, 30 parts of a 10% by mass nitric acid aqueous solution of polyaluminum chloride were added. Next, the mixture was dispersed at 30°C using a homogenizer (IKA Corporation, trade name ULTRA-TURRAX T50), and then heated to 45°C in an oil bath and held for 30 minutes. Afterward, the pH was adjusted to 8.5 by adding 0.1 mol / L sodium hydroxide aqueous solution, and the mixture was heated to 84°C and held for 2.5 hours. Then, the mixture was cooled to 20°C at a rate of 20°C / min, the solid components were filtered out, thoroughly washed with deionized water, and dried to obtain colorant particles (1). The volume average particle size of the colorant particles (1) was 5.9 μm.

[0307] <Making of Carrier 1>

[0308] Ferrite particles (average particle size 35 μm): 100 parts

[0309] Toluene: 14 parts

[0310] • Polymethyl methacrylate (PMMA, weight average molecular weight 75,000): 5 parts

[0311] • Carbon black: 0.2 parts (VXC-72, manufactured by Cabot, volume resistivity: below 100 Ωcm)

[0312] The above materials, excluding ferrite particles, are dispersed in a sand mill to prepare a dispersion. The dispersion and ferrite particles are then loaded into a vacuum degassing kneader and dried under reduced pressure with stirring to obtain carrier 1.

[0313] <Making of Toning Agents>

[0314] To 100 parts by weight of the obtained toner particles (1), 1.5 parts by weight of hydrophobic silica (NIPPON AEROSIL, RY50) and 1.0 parts by weight of hydrophobic titanium dioxide (NIPPON AEROSIL, T805) were mixed using a sample mill at 10,000 rpm for 30 seconds. The mixture was then sieved using a vibrating sieve with a mesh size of 45 μm to prepare toner 1 (a toner for electrostatic image development). The volume average particle size of the obtained toner 1 was 6.0 μm.

[0315] <Preparation of Electrostatic Image Developer>

[0316] Eight parts of toner 1 and 92 parts of carrier 1 were mixed using a V mixer to prepare developer 1 (electrostatic image developer).

[0317] (Example 2)

[0318] <Preparation of Toning Agent Particles (2)>

[0319] Fluorescent colorant particle dispersion (1): 450 parts

[0320] • Release agent particle dispersion (1): 50 parts

[0321] • Anionic surfactant (Daiichi Kogyo Co., Ltd.: NEOGEN RK, 20%): 10 parts

[0322] The above materials were placed in a round stainless steel flask, and the pH was adjusted to 3.5 by adding 0.1N (mol / L) nitric acid. Then, 30 parts of a 10% by mass nitric acid aqueous solution of polyaluminum chloride were added. Next, the mixture was dispersed at 30°C using a homogenizer (IKA Corporation, trade name ULTRA-TURRAX T50), and then heated to 45°C in an oil bath and held for 30 minutes. Subsequently, 50 parts of the adhesive resin particle dispersion (1) were added, and the mixture was held for 1 hour. The pH was adjusted to 8.5 by adding 0.1 mol / L sodium hydroxide aqueous solution, and the mixture was heated to 84°C and held for 2.5 hours. Then, the mixture was cooled to 20°C at a rate of 20°C / min, the solid components were filtered out, and the mixture was thoroughly washed with deionized water and dried to obtain colorant particles (2). The volume average particle size of the colorant particles (2) was 6.0 μm.

[0323] (Example 3)

[0324] <Preparation of Resin Particle Dispersion (2): An Example of Preparing Anionic Particles Based on Emulsion Polymerization>

[0325] • Styrene (manufactured by Wako Pure Chemical Industries, Ltd.): 65.0 parts

[0326] • n-Butyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.): 30.0 parts

[0327] • Sodium p-styrene sulfonate (manufactured by Tosoh Corporation, Spinomer NaSS): 5.0 parts

[0328] • Anionic surfactant (manufactured by Daiichi Kogyo Co., Ltd., NEOGEN RK): 1.0 part

[0329] • Anionic polymerization initiator (ammonium persulfate): 1.0 part

[0330] ·DIW: 400 copies

[0331] The above materials were mixed in a flask and emulsified for 10 minutes using a homogenizer (ULTRA-TURRAX T50, manufactured by IKA). Next, after purging the flask with nitrogen, the solution was heated to 85°C in a water bath with stirring. Emulsion polymerization was carried out at this temperature for 5 hours, followed by cooling to 30°C to obtain an anionic resin particle dispersion (2) with a solids concentration of 20%. A cohesive resin particle dispersion (2) with an average particle size of 180 nm was obtained.

[0332] <Preparation of a Resin Particle Dispersion with Ion-Bonded Fluorescent Colorant (2)>

[0333] • Adhesive resin particle dispersion (2): 475 parts

[0334] • Cationic fluorescent colorant (manufactured by Taoka Chemical Industry Co., Ltd., Rhodamine A (basic violet 11:1)): 5 parts

[0335] The above materials were mixed and the pH was adjusted to 4.5. The mixture was then stirred at 60°C for 1 hour. The concentration of the solid component was adjusted to 20% to obtain a fluorescent colorant particle dispersion (2).

[0336] Fluorescent colorant particle dispersion (2) was used instead of fluorescent colorant particle dispersion (1), and adhesive resin particle dispersion (2) was used instead of adhesive resin particle dispersion (1). Otherwise, the toner and electrostatic image developer were prepared in the same manner as in Example 1.

[0337] (Example 4)

[0338] Fluorescent colorant particle dispersion (2) was used instead of fluorescent colorant particle dispersion (1), and adhesive resin particle dispersion (2) was used instead of adhesive resin particle dispersion (1). Otherwise, the toner and electrostatic image developer were prepared in the same manner as in Example 2.

[0339] (Examples 5 and 6)

[0340] According to the composition in Table 1, the amount of fluorescent colorant particle dispersion (2) was adjusted, and electrostatic image developing agent and electrostatic image developing agent were prepared in the same manner as in Example 4.

[0341] (Example 7)

[0342] <Preparation of Adhesive Resin Particle Dispersion (3)>

[0343] ·Terephthalic acid: 30 moles

[0344] Fumaric acid: 70 moles

[0345] Bisphenol A ethylene oxide adduct: 5 moles

[0346] Bisphenol A propylene oxide adduct: 95 molar parts

[0347] The above materials were added to a flask equipped with a stirrer, nitrogen inlet pipe, temperature sensor, and distillation column. The temperature was raised to 220°C over 1 hour, and 1 part tetraethanolamine was added for every 100 parts of the above materials. While distilling away the generated water, the temperature was raised to 230°C over 30 minutes. The dehydration condensation reaction was continued at this temperature for 1 hour, and then the reactants were cooled. This yielded a polyester resin with a weight-average molecular weight of 18,000 and a glass transition temperature of 60°C.

[0348] 40 parts of ethyl acetate and 25 parts of 2-butanol were added to a container equipped with a temperature control mechanism and a nitrogen purging mechanism to prepare a mixed solvent. Then, 100 parts of polyester resin were slowly added to dissolve it. A 10% by mass ammonia solution (equivalent to 3 times the amount of the resin in molar ratio relative to the acid value) was added and stirred for 30 minutes. The container was then purged with dry nitrogen to maintain the temperature at 40°C. While stirring the mixture, 400 parts of ion-exchanged water were added dropwise at a rate of 2 parts / minute. After the addition was completed, the temperature was restored to room temperature (20°C to 25°C). While stirring, the mixture was bubbled with dry nitrogen for 48 hours to obtain a resin particle dispersion with ethyl acetate and 2-butanol reduced to below 1,000 ppm. Ion-exchanged water was added to the above resin particle dispersion to adjust the solid content to 20% by mass, resulting in an adhesive resin particle dispersion (3).

[0349] Except that the adhesive resin particle dispersion (3) is used instead of the adhesive resin particle dispersion (2), the fluorescent colorant particle dispersion (3) is prepared in the same way as the fluorescent colorant particle dispersion (2).

[0350] <Preparation of Toning Agent Particles (7)>

[0351] Fluorescent colorant particle dispersion (3): 450 parts

[0352] • Release agent particle dispersion (1): 50 parts

[0353] • Anionic surfactant (Daiichi Kogyo Co., Ltd.: NEOGEN RK, 20%): 10 parts

[0354] The above materials were placed in a round stainless steel flask, and the pH was adjusted to 3.5 by adding 0.1N (mol / L) nitric acid. Then, 30 parts of a 10% by mass nitric acid aqueous solution of polyaluminum chloride were added. Next, the mixture was dispersed at 30°C using a homogenizer (IKA, trade name ULTRA-TURRAX T50), and then heated to 45°C in an oil bath and held for 30 minutes. Afterward, the pH was adjusted to 8.5 by adding 0.1 mol / L sodium hydroxide aqueous solution, and the mixture was heated to 84°C and held for 2.5 hours. Then, the mixture was cooled to 20°C at a rate of 20°C / min, the solid components were filtered out, thoroughly washed with deionized water, and dried to obtain colorant particles (7). The volume average particle size of the colorant particles (7) was 5.8 μm.

[0355] Except that toner particles (7) are used instead of toner particles (1), the electrostatic image developing agent and electrostatic image developing agent are prepared in the same manner as in Example 1.

[0356] (Example 8)

[0357] Fluorescent colorant particle dispersion (3): 450 parts

[0358] • Release agent particle dispersion (1): 50 parts

[0359] • Anionic surfactant (Daiichi Kogyo Co., Ltd.: NEOGEN RK, 20%): 10 parts

[0360] The above materials were placed in a round stainless steel flask, and the pH was adjusted to 3.5 by adding 0.1N (= mol / L) nitric acid. Then, 30 parts of a 10% by mass nitric acid aqueous solution of polyaluminum chloride were added. Next, the mixture was dispersed at 30°C using a homogenizer (IKA Corporation, trade name ULTRA-TURRAX T50), and then heated to 45°C in an oil bath and held for 30 minutes. Subsequently, 50 parts of the adhesive resin particle dispersion (3) were added and held for 1 hour. The pH was adjusted to 8.5 by adding 0.1 mol / L sodium hydroxide aqueous solution, and then heated to 84°C and held for 2.5 hours. Next, the mixture was cooled to 20°C at a rate of 20°C / min, the solid components were filtered out, and the mixture was thoroughly washed with deionized water and dried to obtain the colorant particles (8). The volume average particle size of the colorant particles (8) was 5.9 μm.

[0361] Except that toner particles (8) are used instead of toner particles (1), the electrostatic image developing agent and electrostatic image developing agent are prepared in the same manner as in Example 1.

[0362] (Examples 9-12)

[0363] <Preparation of ionically bonded resin particle dispersions (4) to (7)>

[0364] Except for replacing the cationic fluorescent colorant in the ionically bonded fluorescent colorant-containing resin particle dispersion (2) with basic yellow 40 (manufactured by Neelikon Food Dyes And Chemicals Co., Ltd.), basic green 1 (manufactured by Tokyo Kasei Corporation, basic green 1), basic red 1:1 (manufactured by Taoka Chemical Co., Ltd., Rhodamine 6GCP-N), or basic orange 15 (manufactured by Classic Dyestuffs Co., Ltd., Phosphhine 2RN), fluorescent colorant particle dispersions (4) to (7) were prepared in the same manner as the preparation of the fluorescent colorant particle dispersion (2).

[0365] Except for using any one of the fluorescent colorant particle dispersions (4) to (7) instead of the fluorescent colorant particle dispersion (2), the electrostatic image developing toner and electrostatic image developing agent were prepared in the same manner as in Example 8.

[0366] (Examples 13 and 14)

[0367] <Preparation of Colorant Particle Dispersion (1)>

[0368] • Magenta pigment (FASTOGEN SUPER MAGENTA R manufactured by DIC Corporation): 90 parts

[0369] • Anionic surfactant (manufactured by Daiichi Kogyo Co., Ltd., NEOGEN RK): 10 parts

[0370] • Ion-exchanged water: 200 parts

[0371] The above materials were mixed and dispersed for 10 minutes using a homogenizer (ULTRA-TURRAX T50 manufactured by IKA). Ion-exchanged water was added at a solid content of 20% by mass to obtain a colorant particle dispersion (1) containing colorant particles with a volume average particle size of 140 nm.

[0372] In accordance with the mass ratios recorded in Table 1, fluorescent colorant particle dispersion (6) and colorant particle dispersion (1) were further used during the preparation of the toner particles. Otherwise, the toner and electrostatic image developer were prepared in the same manner as in Example 8.

[0373] (Example 15)

[0374] In accordance with the mass ratios recorded in Table 1, a fluorescent colorant particle dispersion (6) was further used during the preparation of the colorant particles. Otherwise, the colorant and electrostatic image developer were prepared in the same manner as in Example 8.

[0375] (Example 16)

[0376] <Preparation of Adhesive Resin Particle Dispersion (2): An Example of Preparing Anionic Particles Based on Emulsion Polymerization>

[0377] • Styrene (manufactured by Wako Pure Chemical Industries, Ltd.): 65.0 parts

[0378] • n-Butyl acrylate (manufactured by Wako Pure Chemical Industries, Ltd.): 30.0 parts

[0379] • Sodium p-styrene sulfonate (manufactured by Tosoh Corporation, Spinomer NaSS): 5.0 parts

[0380] • Cationic fluorescent colorant (manufactured by Fujifilm-Wako Pure Chemicals Co., Ltd., polymeric dye Fluorouryviolet R13): 1.91 parts

[0381] • Anionic surfactant (manufactured by Daiichi Kogyo Co., Ltd., NEOGEN RK): 1.0 part

[0382] • Anionic polymerization initiator (ammonium persulfate): 1.0 part

[0383] ·DIW: 400 copies

[0384] The above materials were mixed in a flask and emulsified for 10 minutes using a homogenizer (ULTRA-TURRAX T50, manufactured by IKA). Next, after nitrogen purging of the flask, the solution was heated to 85°C in a water bath with stirring. Emulsion polymerization was carried out under these conditions for 5 hours, followed by cooling to 30°C to obtain an anionic resin particle dispersion with a solid content of 20%. A resin particle dispersion with an average particle size of 180 nm was obtained. Except that the anionic resin particle dispersion obtained above was used instead of the fluorescent colorant particle dispersion (2), a toner and an electrostatic image developer were prepared in the same manner as in Example 6.

[0385] (Comparative Example 1)

[0386] • Anionic adhesive resin particle dispersion (2) after dialysis cleaning and drying curing: 85.5 parts

[0387] • Anionic dye (Tokyo Chemical Industry Co., Ltd., Acid Red 52): 4.5 parts

[0388] • Solid paraffin wax (manufactured by Nippon Seika Co., Ltd., HNP-9): 10 parts

[0389] The above components were heated and mixed (170°C, 2 hours), coarsely pulverized using a Banbury mixer, and further pulverized using an AFG100 pulverizer (manufactured by Hosokawa Micron Co., Ltd.) to obtain colorant particles (C1). The volume average particle size of the colorant particles (C1) was 6.1 μm.

[0390] Using the obtained toner particles (C1), an electrostatic image developing toner and an electrostatic image developing agent were prepared in the same manner as in Example 1.

[0391] It should be noted that in the dialysis cleaning method, the resin particle dispersion is loaded into the dialysis membrane, replaced with deionized water (DIW), and then freeze-dried for cleaning.

[0392] (Comparative Example 2)

[0393] • 100 parts of colorant particles (C1) from Comparative Example 1

[0394] • 10 parts of dried and cured anionic adhesive resin particle dispersion (2) after dialysis cleaning and drying.

[0395] The above components were mixed using Nobilta 300 (manufactured by Hosokawa Micron Co., Ltd.) to obtain toner particles (C2) coated with a shell. The volume average particle size of the toner particles (C2) was 6.2 μm.

[0396] Using the obtained toner particles (C2), an electrostatic image developing toner and an electrostatic image developing agent were prepared in the same manner as in Example 1.

[0397] (Comparative Example 3)

[0398] • 85.5 parts of dried and cured product of adhesive resin particle dispersion (1) after dialysis cleaning and drying.

[0399] • Cationic dye (Rohodamine A, manufactured by Taoka Chemical Co., Ltd.): 4.5 parts

[0400] • Solid paraffin wax (manufactured by Nippon Seika Co., Ltd., HNP-9): 10 parts

[0401] The above components were heated and mixed (170°C, 2 hours), coarsely pulverized using a Banbury mixer, and further pulverized using an AFG100 pulverizer (manufactured by Hosokawa Micron Co., Ltd.) to obtain colorant particles (C3). The volume average particle size of the colorant particles (C3) was 6.1 μm.

[0402] Using the obtained toner particles (C3), electrostatic charge enhancement toner and electrostatic image developer were prepared in the same manner as in Example 1.

[0403] It should be noted that in the dialysis cleaning method, the resin particle dispersion is loaded into the dialysis membrane, replaced by DIW, and then freeze-dried for cleaning.

[0404] (Comparative Example 4)

[0405] • 100 parts of colorant particles (C3) from Comparative Example 3

[0406] • 10 parts of dried and cured product of adhesive resin particle dispersion (1) after dialysis cleaning and drying:

[0407] The above components were mixed with Nobilta 300 (manufactured by Hosokawa Micron Co., Ltd.) to obtain toner particles (C4) coated with a shell. The volume average particle size of the toner particles (C4) was 6.2 μm.

[0408] Using the obtained toner particles (C4), an electrostatic image developing toner and an electrostatic image developing agent were prepared in the same manner as in Example 1.

[0409] (Comparative Example 5)

[0410] By changing the amount of cationic dye and using the fluorescent colorant content recorded in Table 1, the toner and electrostatic image developer for electrostatic image development were prepared in the same manner as in Comparative Example 4.

[0411] (Comparative Example 6)

[0412] Further changes were made to the amounts of fluorescent colorant particle dispersion (2) and colorant particle dispersion (1), using the fluorescent colorant content recorded in Table 1. Otherwise, the toner and electrostatic image developer were prepared in the same manner as in Example 13.

[0413] (Comparative Example 7)

[0414] <Resin Preparation Method: Example of Anionic Particle Production Based on Emulsion Polymerization>

[0415] • Methyl methacrylate (manufactured by Wako Pure Chemical Industries, Ltd.): 95.0 parts

[0416] • Sodium p-styrene sulfonate (manufactured by Tosoh Corporation, Spinomer NaSS): 5.0 parts

[0417] • Anionic surfactant (manufactured by Daiichi Kogyo Co., Ltd., NEOGEN RK): 1.0 part

[0418] • Anionic polymerization initiator (ammonium persulfate): 1.0 part

[0419] ·DIW: 400 copies

[0420] The above materials were mixed in a flask and emulsified for 10 minutes using a homogenizer (ULTRA-TURRAX T50, IKA). Next, the flask was purged with nitrogen, and the solution was heated to 85°C in a water bath with stirring. Emulsion polymerization was carried out at this temperature for 5 hours, followed by cooling to 30°C to obtain an anionic resin particle dispersion with a solids concentration of 20%. A resin particle dispersion with a particle size of 210 nm was obtained.

[0421] Impurities are removed using a dialysis membrane, and the dried product (resin A) is obtained by freeze drying.

[0422] <Production of dye-colored resins: mixing and pulverizing>

[0423] • Resin A: 75 parts

[0424] • Cationic dye (manufactured by Taoka Chemical Co., Ltd., Rohodamine A): 4.8 parts

[0425] The above components were heated and mixed (170°C, 2 hours), coarsely pulverized using a Banbury mixer, and further pulverized to 0.5 μm using an AFG100 pulverizer (manufactured by Hosokawa Micron Co., Ltd.) to obtain colored resin particles.

[0426] <Preparation of Fluorescent Colorant Particle Dispersion (8)>

[0427] • 90 parts of the above-mentioned colored resin particles

[0428] • Anionic surfactant (manufactured by Daiichi Kogyo Co., Ltd., NEOGEN RK): 10 parts

[0429] • Ion-exchanged water: 200 parts

[0430] The above materials were mixed and dispersed for 10 minutes using a homogenizer (ULTRA-TURRAX T50 manufactured by IKA). Ion-exchanged water was added to bring the solid content in the dispersion to 20% by mass, resulting in a fluorescent colorant particle dispersion (8) containing fluorescent colorant particles with a volume average particle size of 0.5 μm.

[0431] The fluorescent colorant particle dispersion (2) was changed to the fluorescent colorant particle dispersion (8), and the amount of fluorescent colorant was changed according to Table 1. Otherwise, the toner and electrostatic image developer were prepared in the same manner as in Example 4.

[0432] Furthermore, in the electrostatic image developing toner of Comparative Example 7, the fluorescent colorant was not dispersed in the adhesive resin, but only existed in the polymethyl methacrylate copolymer particles.

[0433] (Comparative Example 8)

[0434] Except for changing the amount of fluorescent colorant as described in Table 1, electrostatic image developing toner and electrostatic image developing agent were prepared in the same manner as in Comparative Example 7.

[0435] Furthermore, in the electrostatic image developing toner of Comparative Example 8, the fluorescent colorant was not dispersed in the adhesive resin, but only existed in the polymethyl methacrylate copolymer particles.

[0436] The electrostatic image developing toners and electrostatic image developers obtained in Examples 1-16 and Comparative Examples 1-8 were evaluated as follows. The evaluation results are summarized in Table 1.

[0437] <Fluorescence Intensity Evaluation>

[0438] The following operations and image formation were performed in an environment with a temperature of 23°C and a humidity of 50% RH.

[0439] As an image forming apparatus for forming evaluation images, an ApeosPortIVC4470 manufactured by Fuji Xerox Corporation was prepared. The developer was loaded into the developer unit, and the replenishing toner (the same toner contained in the developer) was loaded into the toner cartridge. Next, the image was formed on OS coated paper (basic weight 127 g / m²) manufactured by Fuji Xerox Corporation. 2 An image of 5cm × 5cm with 100% image area ratio was formed on the image (the tonal dose per unit area was 4.5g / m²). 2 The image was output at a fixing temperature of 170℃, and the fluorescence intensity was evaluated.

[0440] Regarding fluorescence intensity, the spectrophotometric reflectance in the visible light region was measured using X-Rite (manufactured by X-Rite Corporation), and the fluorescence peak intensity at the spectrophotometric reflectance was taken as the fluorescence intensity.

[0441] A: More than 112%

[0442] B: 108% or higher but less than 112%

[0443] C: 104% or higher but less than 108%

[0444] D: 100% or more but less than 104%

[0445] E: Less than 100%

[0446] <Image Graininess Evaluation (Color Noise)>

[0447] In the fluorescence intensity evaluation described above, the output image is a mid-tone image with an image area ratio of 50%. Otherwise, the same image is output to create an evaluation image, and the following graininess evaluation is performed.

[0448] Image quality was evaluated using an index called color noise (CN), which is obtained by quantifying density unevenness at intervals of less than 1 mm. The results are shown in Table 1. The CN index is an index that quantifies graininess as a sensory evaluation value; the lower the CN, the better the image quality.

[0449] A: The CN index value is below 3.0.

[0450] B: The CN index value is greater than 3.0 and less than 3.5.

[0451] C: The CN index value is greater than 3.5 and less than 4.0.

[0452] D: The CN index value is greater than 4.0.

[0453] <Abrasion Resistance Evaluation>

[0454] Prepare an evaluation image identical to the one output in the above particle texture evaluation, and perform the following abrasion resistance evaluation.

[0455] For the evaluation images, a Tribo Gear 14DR surface testing machine (manufactured by Shin-To Science Co., Ltd.) was used. Unused OK Prince fiberless paper was placed on the image, and the surface of the fixed image was rubbed with the unused paper under a vertical load of 100g, a rubbing speed of 10mm / second, a rubbing amplitude of 2cm, and a rubbing number of 10 times. The dirt on the unused paper after rubbing was observed by visual inspection and by using a 50x magnifying glass.

[0456] The evaluation criteria are as follows.

[0457] A: No stains caused by colorants were identified.

[0458] B: No stains caused by colorant could be visually identified, but slight stains were observed with a magnifying glass.

[0459] C: Very slight stains caused by colorant were visible to the naked eye.

[0460] D: Significant stains caused by colorants can be visually confirmed.

[0461]

[0462]

[0463] It should be noted that *1 in Table 1 indicates that the fluorescent colorant is not dispersed in the adhesive resin, but exists only in the particles of polymethyl methacrylate copolymer.

[0464] As shown in Table 1 above, compared with the resin particles (electrostatic image developing toner) of the comparative example, the resin particles (electrostatic image developing toner) of this embodiment produce images with higher fluorescence intensity.

[0465] Furthermore, as shown in Table 1 above, the resin particles (tone agent for electrostatic image development) of this embodiment can suppress the graininess of the obtained image, and the obtained image also has excellent abrasion resistance.

[0466] (Example 17)

[0467] -Production of Coatings-

[0468] On a 10cm×10cm quadrilateral test plate of zinc phosphate treated steel plate, the resin particles of Example 1 were coated by sliding the corona gun manufactured by Asahi Suntec Co., Ltd. from a distance of 30cm from the front side in a manner with a coating thickness of 30μm to 50μm. Then, the coated product was prepared by calcination at 150°C for 5 minutes.

[0469] In the prepared coating, the powder adhered to the coated material (zinc phosphate treated steel plate), confirming that coating had been performed.

Claims

1. A toner for electrostatic image development, the toner for electrostatic image development comprising: resin particles of a core / shell type containing a fluorescent colorant and a binding resin, the fluorescent colorant is ionically bonded to the binding resin, a content of other colorants than the fluorescent colorant is 2 mass% or less with respect to the entire resin particles, a ratio WB / WA of a content WB of the other colorants to a content WA of the fluorescent colorant is 1.25 or less, a content of the fluorescent colorant is 0.2 mass% or more and 5 mass% or less with respect to the entire resin particles.

2. The electrostatic image developing toner as claimed in claim 1, wherein, the fluorescent colorant does not emerge on a surface of the resin particles.

3. The toner for electrostatic image development according to claim 1, wherein, the binding resin has an anionic group, the fluorescent colorant has a cationic group.

4. The toner for electrostatic image development according to claim 1, wherein, the binding resin has a cationic group, the fluorescent colorant has an anionic group.

5. The electrostatic image developing toner as claimed in claim 1 or 2, wherein, the fluorescent colorant is a fluorescent dye.

6. The electrostatic image developing toner as claimed in claim 5, wherein, the fluorescent dye contains a fluorescent dye having an extreme fluorescent wavelength in a range of 580 nm to 650 nm. the fluorescent dye contains a fluorescent dye having an extreme fluorescent wavelength in a range of 580 nm to 650 nm.

Images