Resin fine particles, thermoplastic resin particles, and method for producing resin fine particles

Abstract

The present invention provides resin fine particles, thermoplastic resin particles, and a method for producing resin fine particles, the resin fine particles containing a polyester resin and a basic dye, the volume average particle diameter of the resin fine particles being 0.05 μm or more and 1 μm or less, and the concentration ratio of the basic dye in the center-of-gravity portion of the resin fine particles relative to the surface layer portion of the resin fine particles to a depth of 10 nm or less from the surface of the resin fine particles being 0.8 or more.

Description

TECHNICAL FIELD

[0001] The present application relates to resin fine particles, thermoplastic resin particles, and a method for producing resin fine particles. BACKGROUND

[0002] As the existing resin fine particles, resin fine particles described in Patent Documents 1 to 4 are known.

[0003] In Patent Document 1, a dyed emulsion composition containing an emulsion polymer and a dye is disclosed, the emulsion polymer being obtained by emulsion polymerization of a monomer mixture containing a vinyl monomer (A) having a cyano group, a vinyl monomer (B) having an acidic functional group, and other vinyl monomers (C) in the presence of an anionic surfactant (D) having a structure represented by the following formula (1).

[0004]

[0005] In the above formula (1), R 1 is a hydrogen atom or a methyl group, R 2 is an alkyl group having 1 to 4 carbon atoms, Y is an alkylene group having 2 to 4 carbon atoms, M is a monovalent or divalent cation, k is an integer of 1 to 3, m is an integer of 1 to 100, and n is 1 or 2.

[0006] In Patent Document 2, a fluorescent organic nanoparticle is disclosed, which comprises a polymer matrix containing one or two or more crosslinked polymer resins, and one or two or more fluorescent dyes incorporated in the polymer matrix, the fluorescent organic nanoparticle having a particle size of less than 500 nm.

[0007] In Patent Document 3, a fluorescent pigment composition is disclosed, which comprises a fluorescent dye and a polyamide-polyester thermoplastic resin generated by condensation reaction of a polybasic acid selected from the group consisting of isophthalic acid, terephthalic acid, 2,6-naphthalene dicarboxylic acid, and trimesic acid, and at least one aliphatic primary amino alcohol having 2 to 4 carbon atoms.

[0008] In addition, as an example of the thermoplastic resin particles, in Patent Document 4, a toner is disclosed, which is a toner containing a binding resin and a colorant, characterized in that the colorant contains a coloring pigment and a fluorescent dye, and the content of the coloring pigment and the content of the fluorescent dye in the toner on a mass basis are respectively set to W G , W F , and the above W G and the above W F satisfy the following formula (1),

[0009] W G x 0.5 > WF >W G ×0.025 (1)

[0010] The absorption peak wavelength of the above coloring pigment is set to P G , and the emission peak wavelength of the above fluorescent dye is set to P F , the above P G and the above P F satisfy the following formula (2).

[0011] P G <P F (2)

[0012] Prior Art Documents

[0013] Patent Documents

[0014] Patent Document 1: Japanese Patent Application Laid-Open (JP-A) No. 2004-10846

[0015] Patent Document 2: Japanese Patent Application Laid-Open (JP-A) No. 2010-90739

[0016] Patent Document 3: Japanese Patent Application Laid-Open (JP-A) No. Hei 3-177461

[0017] Patent Document 4: Japanese Patent Application Laid-Open (JP-A) No. 2017-3818 SUMMARY

[0018] PROBLEMS TO BE SOLVED BY THE INVENTION

[0019] The present application provides a resin fine particle, which is a resin fine particle containing a polyester resin and a basic dye, and which has a higher color development density than a case where the volume average particle diameter of the resin fine particle is less than 0.05 μm or more than 1 μm, or the concentration ratio of the basic dye in the center-of-gravity portion of the resin fine particle with respect to the surface layer portion of the resin fine particle to a depth of 10 nm or less from the surface of the resin fine particle is less than 0.8.

[0020] Further, another object of the present application is to provide a thermoplastic resin particle having a higher color development density than a case where the average distance X D in the cross section of the thermoplastic resin particle between adjacent regions containing the basic dye is more than 0.05 μm or less than 0.025 μm.

[0021] MEANS FOR SOLVING THE PROBLEMS

[0022] Specific means for solving the above problems include the following modes.

[0023] <1> A resin fine particle which is a resin fine particle containing a polyester resin and a basic dye, wherein the volume average particle diameter of the resin fine particle is 0.05 μm or more and 1 μm or less, and the ratio of the concentration of the basic dye in the center-of-gravity portion of the resin fine particle to the concentration of the basic dye in the surface layer portion of the resin fine particle to a depth of 10 nm or less from the surface is 0.8 or more.

[0024] <2> The resin fine particle according to <1>, wherein the volume average particle diameter of the resin fine particle is 0.05 μm or more and 0.5 μm or less.

[0025] <3> The resin fine particle according to <1>, wherein the content of the basic dye in the resin fine particle is 0.1 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polyester resin in the resin fine particle.

[0026] <4> The resin fine particle according to <3>, wherein the content of the basic dye in the resin fine particle is 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polyester resin in the resin fine particle.

[0027] <5> The resin fine particle according to <1>, wherein the basic dye comprises a basic fluorescent dye.

[0028] <6> The resin fine particle according to <1>, wherein the acid value of the polyester resin is 1 mgKOH / g or more and 50 mgKOH / g or less.

[0029] <7> The resin fine particle according to <6>, wherein the acid value of the polyester resin is 5 mgKOH / g or more and 18 mgKOH / g or less.

[0030] <8> A thermoplastic resin particle which comprises a binder resin and the resin fine particle according to <1>.

[0031] <9> The thermoplastic resin particle according to <8>, wherein, in a cross section of the thermoplastic resin particle, the average distance X between adjacent regions containing the basic dye D satisfies the following formula L:

[0032] 0.01 x D 50v ≤ X D ≤ 0.4 x D 50v Formula L

[0033] Note that D 50v represents the volume average particle diameter of the thermoplastic resin particle.

[0034] <10> The thermoplastic resin particle according to <9>, wherein the average distance X between adjacent regions containing the basic dye D0.05 μm or more and 3.0 μm or less.

[0035] <11> The thermoplastic resin particles according to <10>, wherein the average distance X D 0.08 μm or more and 2.5 μm or less.

[0036] <12> The thermoplastic resin particles according to claim 8, which are produced by at least coagulating the resin fine particles.

[0037] <13> A method for producing resin fine particles according to <1>, comprising: a dissolving or melting step of bringing at least an oily mixture of a polyester resin, a base, and a basic dye into a dissolved state or a molten state while imparting a shear force thereto; and an emulsifying step of adding a surfactant and an aqueous medium to emulsify the dissolved or molten oily mixture while imparting a shear force thereto to obtain a dispersion liquid of the resin fine particles.

[0038] <14> The method for producing resin fine particles according to <13>, wherein the pH of the dispersion liquid is 7 or more and 11 or less.

[0039] Effects of the Invention

[0040] According to the invention of the above <1> or <5>, there are provided resin fine particles, which are resin fine particles containing a polyester resin and a basic dye, and which have a higher color development density than in a case where the volume average particle diameter of the resin fine particles is less than 0.05 μm or more than 1 μm, or the concentration ratio of the basic dye in a center-of-gravity portion of the resin fine particles to a surface layer portion of the resin fine particles having a depth of 10 nm or less from the surface of the resin fine particles is less than 0.8.

[0041] According to the invention of the above <2>, there are provided resin fine particles having a higher color development density than in a case where the volume average particle diameter of the resin fine particles is less than 0.05 μm or more than 0.5 μm.

[0042] According to the invention of the above <3>, there are provided resin fine particles having a higher color development density than in a case where the content of the basic dye is less than 0.1 parts by mass or more than 20 parts by mass with respect to 100 parts by mass of the content of the polyester resin.

[0043] According to the invention of the above <4>, there are provided resin fine particles having a higher color development density than in a case where the content of the basic dye is less than 0.5 parts by mass or more than 10 parts by mass with respect to 100 parts by mass of the content of the polyester resin.

[0044] According to the invention of the above <6>, there are provided resin fine particles having a higher color development density than in a case where the acid value of the polyester resin is less than 1 mgKOH / g or more than 50 mgKOH / g.

[0045] According to the invention described in the above <7>, there is provided a resin fine particle having a higher color development density than in the case where the acid value of the above polyester resin is less than 5 mgKOH / g or more than 18 mgKOH / g.

[0046] According to the invention described in the above <8>, there is provided a thermoplastic resin particle which is a resin fine particle containing a polyester resin and a basic dye, having a higher color development density than in the case where the volume average particle diameter is less than 0.05 μm or more than 1 μm, or the concentration ratio of the above basic dye in the center-of-gravity portion of the above resin fine particle with respect to the surface layer portion of the above resin fine particle having a depth of 10 nm or less from the surface of the above resin fine particle is less than 0.8.

[0047] According to the invention described in the above <9>, there is provided a thermoplastic resin particle having a higher color development density than in the case where the average distance X between the adjacent regions containing the above basic dye in the cross section of the above thermoplastic resin particle is less than 0.05 μm or more than 3.0 μm. D

[0048] According to the invention described in the above <10>, there is provided a thermoplastic resin particle having a higher color development density than in the case where the average distance X between the adjacent regions containing the above basic dye in the cross section of the above thermoplastic resin particle is less than 0.05 μm or more than 3.0 μm. D

[0049] According to the invention described in the above <11>, there is provided a thermoplastic resin particle having a higher color development density than in the case where the average distance X between the adjacent regions containing the above basic dye in the cross section of the above thermoplastic resin particle is less than 0.05 μm or more than 3.0 μm. D

[0050] According to the invention described in the above <12>, there is provided a thermoplastic resin particle which is a resin fine particle containing a polyester resin and a basic dye, having a higher color development density than in the case where the volume average particle diameter is less than 0.05 μm or more than 1 μm, or the concentration ratio of the above basic dye in the center-of-gravity portion of the above resin fine particle with respect to the surface layer portion of the above resin fine particle having a depth of 10 nm or less from the surface of the above resin fine particle is less than 0.8.

[0051] According to the invention described in the above <13>, there is provided a method for producing a resin fine particle containing a polyester resin and a basic dye, having a higher color development density than in the case where the volume average particle diameter is less than 0.05 μm or more than 1 μm, or the concentration ratio of the above basic dye in the center-of-gravity portion of the above resin fine particle with respect to the surface layer portion of the above resin fine particle having a depth of 10 nm or less from the surface of the above resin fine particle is less than 0.8.

[0052] According to the invention described in the above <14>, there is provided a method for producing a resin fine particle having a higher color development density than in the case where the pH of the above dispersion liquid is less than 7 or more than 11. BRIEF DESCRIPTION OF DRAWINGS ​​​

[0053] Figure 1 is a schematic configuration view showing an image forming apparatus when the thermoplastic resin particles of the present embodiment are used as a toner for electrostatic image development.

[0054] Figure 2 is a schematic configuration view showing a process cartridge when the thermoplastic resin particles of the present embodiment are used as an electrostatic image developer.

[0055] Explanation of symbols

[0056] 1Y, 1M, 1C, 1K photoreceptor (example of image holding body)

[0057] 2Y, 2M, 2C, 2K charging roller (example of charging mechanism)

[0058] 3 exposure device (example of electrostatic image forming mechanism)

[0059] 3Y, 3M, 3C, 3K laser beam

[0060] 4Y, 4M, 4C, 4K developing device (example of developing mechanism)

[0061] 5Y, 5M, 5C, 5K primary transfer roller (example of primary transfer mechanism)

[0062] 6Y, 6M, 6C, 6K photoreceptor cleaning device (example of image holding body cleaning mechanism)

[0063] 8Y, 8M, 8C, 8K toner cartridge

[0064] 10Y, 10M, 10C, 10K image forming unit

[0065] 20 intermediate transfer belt (example of intermediate transfer body)

[0066] 22 drive roller

[0067] 24 support roller

[0068] 26 secondary transfer roller (example of secondary transfer mechanism)

[0069] 28 fixing device (example of fixing mechanism)

[0070] 30 intermediate transfer belt cleaning device (example of intermediate transfer body cleaning mechanism)

[0071] P recording paper (example of recording medium)

[0072] 107 photoreceptor (example of image holding body)

[0073] 108 charging roller (example of charging mechanism)

[0074] 109 exposure device (example of electrostatic image forming mechanism)

[0075] 111 developing device (example of developing mechanism)

[0076] 112 transfer device (example of transfer mechanism)

[0077] 113 photoreceptor cleaning device (example of image holding body cleaning mechanism)

[0078] 115 fixing device (example of fixing mechanism)

[0079] 116 installation guide rail

[0080] 117 housing

[0081] 118 opening portion for exposure

[0082] 200 process cartridge

[0083] 300 recording paper (example of recording medium) DETAILED DESCRIPTION

[0084] In the present specification, in the case where the amount of each component in a composition is mentioned, in the case where two or more kinds of substances conforming to each component are present in the composition, the total amount of the two or more kinds of substances present in the composition is meant, unless specifically stated otherwise.

[0085] Hereinafter, an embodiment as an example of the present application will be described.

[0086] <Resin fine particle>

[0087] The resin fine particle of the present embodiment is a resin fine particle containing a polyester resin and a basic dye, wherein the volume average particle diameter is 0.05 μm or more and 1 μm or less, and the concentration ratio of the basic dye in the center of gravity portion of the resin fine particle with respect to the surface layer portion of the resin fine particle having a depth of 10 nm or less from the surface is 0.8 or more.

[0088] The present inventors have conducted detailed studies, and as a result, have found that, with the conventional resin fine particle containing a polyester resin and a basic dye, the dispersibility of the basic dye within the resin fine particle and the dispersibility of the resin fine particle itself when used in toner and the like are insufficient, and sometimes the color development density becomes low.

[0089] The resin fine particle of the present embodiment has obtained an image and the like having a high color development density by the above constitution. The reason for this is not certain, but is presumed based on the reasons shown below.

[0090] By containing a polyester resin and a basic dye, the volume average particle diameter is 0.05 μm or more and 1 μm or less, the concentration ratio of the basic dye in the center-of-gravity portion of the resin fine particle with respect to the surface layer portion of the resin fine particle to a depth of 10 nm or less from the surface of the resin fine particle is 0.8 or more, thereby the resin fine particle is dyed with the basic dye into the inside of the particle, and is a particle having a small particle diameter, and thus, a thermoplastic resin particle having excellent dispersibility, less unevenness of dye, and a high color density image is obtained.

[0091] The resin fine particle of the present embodiment is suitable for use as an image forming resin fine particle, and is suitable for use as a colorant resin fine particle of a thermoplastic resin particle, and is more suitable for use as a fluorescent colorant resin fine particle of a thermoplastic resin particle.

[0092] Hereinafter, the resin fine particle of the present embodiment will be described in detail.

[0093] In the resin fine particle of the present embodiment, the concentration ratio of the basic dye in the center-of-gravity portion of the resin fine particle with respect to the surface layer portion of the resin fine particle to a depth of 10 nm or less from the surface of the resin fine particle is 0.8 or more, and from the viewpoints of the dispersibility of the basic dye in the resin fine particle, the dispersibility of the resin fine particle, and the color density, it is preferably 0.85 or more, more preferably 0.9 or more, and particularly preferably 0.92 or more and 1.0 or less.

[0094] In the present embodiment, the measurement of the concentration ratio of the basic dye in the center-of-gravity portion of the resin fine particle with respect to the surface layer portion of the resin fine particle to a depth of 10 nm or less from the surface of the resin fine particle in the resin fine particle is performed by the following method.

[0095] The resin fine particle is embedded in a resin and cut by a microtome to obtain a cross section.

[0096] For the cross section, whether or not an element derived from the dye (for example, Zn in the case of Basic Violet 11: 1) is present is analyzed (specifically, mapping) by scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX) analysis.

[0097] The concentration of the element derived from the dye is calculated for the surface layer (less than 10 nm from the profile in the cross-sectional view of the resin fine particles) and the center of gravity of the cross section of the resin fine particles, respectively. Specifically, for one particle, the average concentration (or the total amount of the element) of the element derived from the dye in each 5 nm square at the surface layer 5 and the center of gravity is calculated, and the above calculation is performed for 50 particles. In the case of using the average, for each particle, the average of the concentration ratio of the concentration at the surface layer 5 to the concentration at the center of gravity is calculated, and the average of the concentration ratios of the 50 resin fine particles is calculated as the value of the concentration ratio of the basic dye described above. In the case of using the total amount of the element, for each particle, the ratio of the total amount of the element at the surface layer 5 to the total amount of the element at the center of gravity is calculated, and the average of the ratios of the 50 resin fine particles is calculated as the value of the concentration ratio of the basic dye described above. In the case of calculating the concentration of the element derived from the dye (either the average concentration or the total amount), the presence or absence of the element derived from the dye is binarized and contrast is imparted by SEM-EDX analysis.

[0098] The volume average particle diameter of the resin fine particles of the present embodiment is 0.05 μm or more and 1 μm or less, and from the viewpoint of the dispersibility of the basic dye in the resin fine particles, the dispersibility of the resin fine particles, and the color development concentration, it is preferably 0.08 μm or more and 0.8 μm or less, more preferably 0.1 μm or more and 0.5 μm or less, and particularly preferably 0.1 μm or more and 0.3 μm or less.

[0099] The volume average particle diameter of the resin fine particles of the present embodiment is measured by the following method.

[0100] Using the particle size distribution obtained by the measurement by the laser diffraction type particle size distribution measuring device (manufactured by HORIBA, Ltd., LA-700), for the divided particle size range (section), the cumulative distribution is plotted from the small particle diameter side for the volume, and the particle diameter at which 50% of the total particles are accumulated is measured as the volume average particle diameter Dv50. 50v .

[0101] (Polyester Resin)

[0102] The resin fine particles of the present embodiment contain a polyester resin.

[0103] As the polyester resin, for example, a publicly known polyester resin can be given.

[0104] • Amorphous Polyester Resin

[0105] As the amorphous polyester resin, for example, a polycondensate of a polybasic acid and a polyhydric alcohol can be given. Note that as the amorphous polyester resin, a commercially available product can be used, or a synthetic amorphous polyester resin can be used.

[0106] Note that the "crystallinity" of the resin means that there is no stepwise endothermic change and a clear endothermic peak is present in differential scanning calorimetry (DSC), and specifically, that the half-peak width of the endothermic peak is within 10°C when measured at a temperature increase rate of 10°C / minute.

[0107] On the other hand, the "amorphousness" of the resin means that the half-peak width exceeds 10°C, a stepwise endothermic change is present, or no clear endothermic peak is found.

[0108] As the polycarboxylic acid, for example, aliphatic dicarboxylic acids (e.g., oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid, etc.), alicyclic dicarboxylic acids (e.g., cyclohexane dicarboxylic acid, etc.), aromatic dicarboxylic acids (e.g., terephthalic acid, isophthalic acid, phthalic acid, naphthalene dicarboxylic acid, etc.), acid anhydrides thereof, or lower (e.g., carbon number 1 to 5) alkyl esters thereof can be given. Among these, as the polycarboxylic acid, for example, aromatic dicarboxylic acids are preferred.

[0109] As the polycarboxylic acid, a carboxylic acid of three or more valences having a crosslinking structure or a branched chain structure can be used in combination with the dicarboxylic acid. As the carboxylic acid of three or more valences, for example, trimellitic acid, pyromellitic acid, acid anhydrides thereof, or lower (e.g., carbon number 1 to 5) alkyl esters thereof, etc. can be given.

[0110] The polycarboxylic acid can be used alone or in combination with two or more kinds.

[0111] As the polyol, for example, aliphatic diols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butylene glycol, hexanediol, neopentyl glycol, etc.), alicyclic diols (e.g., cyclohexanediol, cyclohexane dimethanol, hydrogenated bisphenol A, etc.), aromatic diols (e.g., oxirane adduct of bisphenol A, propylene oxide adduct of bisphenol A, etc.) can be given. Among these, as the polyol, for example, aromatic diols, alicyclic diols are preferred, and aromatic diols are more preferred.

[0112] As the polyol, a polyol of three or more valences having a crosslinking structure or a branched chain structure can be used in combination with the diol. As the polyol of three or more valences, for example, glycerol, trimethylolpropane, pentaerythritol can be given.

[0113] The polyol can be used alone or in combination with two or more kinds.

[0114] The glass transition temperature (Tg) of the amorphous polyester resin is preferably 50°C or higher and 80°C or lower, and more preferably 50°C or higher and 65°C or lower.

[0115] Note that the glass transition temperature is calculated from a DSC curve obtained by differential scanning calorimetry (DSC), and more specifically, from the "extrapolated glass transition start temperature" described in the method for calculating the glass transition temperature of JIS K 7121-1987 "Plastics: Methods of test for transition temperatures".

[0116] The weight average molecular weight (Mw) of the amorphous polyester resin is preferably 5,000 or more and 1,000,000 or less, and more preferably 7,000 or more and 500,000 or less.

[0117] The number average molecular weight (Mn) of the amorphous polyester resin is preferably 2,000 or more and 100,000 or less.

[0118] The molecular weight distribution Mw / Mn of the amorphous polyester resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less.

[0119] Note that the weight average molecular weight and the number average molecular weight are measured by gel permeation chromatography (GPC). In the GPC-based molecular weight measurement, GPC HLC-8120 GPC manufactured by Tosoh Corporation was used as the measuring device, column TSKgel Super HM-M (15 cm) manufactured by Tosoh Corporation was used, and THF solvent was used. The weight average molecular weight and the number average molecular weight were calculated from the measurement results using a molecular weight calibration curve prepared from monodisperse polystyrene standard samples.

[0120] The amorphous polyester resin is obtained by a publicly known production method. Specifically, for example, it is obtained by a method in which the polymerization temperature is 180°C or more and 230°C or less, and the reaction system is depressurized as necessary, and the reaction is performed while removing water and alcohol generated at the time of condensation.

[0121] Note that in the case where the monomers of the raw materials are not dissolved or not compatible at the reaction temperature, a high-boiling solvent can be added as a dissolution aid to dissolve them. In this case, the polycondensation reaction is performed while distilling and removing the dissolution aid. In the case where there are monomers that are not compatible, the monomers that are not compatible and the acid or alcohol to be polycondensed with the monomers can be condensed in advance and then polycondensed together with the main components.

[0122] • Crystalline polyester resin

[0123] As the crystalline polyester resin, a condensate of a polybasic acid and a polyol can be given, for example. Note that as the crystalline polyester resin, a commercially available product can be used, or a synthetic crystalline polyester resin can be used.

[0124] Here, for the crystalline polyester resin, in order to easily form a crystal structure, it is preferable to use a polycondensate of a polymerizable monomer having a linear aliphatic group, as compared to a polymerizable monomer having an aromatic group.

[0125] As the polybasic acid, there can be mentioned, for example, aliphatic dicarboxylic acids (e.g., oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedioic acid, 1,10-decanedioic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, 1,18-octadecanedioic acid, etc.), aromatic dicarboxylic acids (e.g., phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, etc.), anhydrides thereof, or lower (e.g., carbon number 1 to 5) alkyl esters thereof.

[0126] As the polybasic acid, there can be mentioned, for example, aliphatic dicarboxylic acids (e.g., oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedioic acid, 1,10-decanedioic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, 1,18-octadecanedioic acid, etc.), aromatic dicarboxylic acids (e.g., phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, etc.), anhydrides thereof, or lower (e.g., carbon number 1 to 5) alkyl esters thereof.

[0127] As the polybasic acid, there can be mentioned, for example, aliphatic dicarboxylic acids (e.g., oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedioic acid, 1,10-decanedioic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, 1,18-octadecanedioic acid, etc.), aromatic dicarboxylic acids (e.g., phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, etc.), anhydrides thereof, or lower (e.g., carbon number 1 to 5) alkyl esters thereof.

[0128] The polybasic acid can be used singly or in combination of two or more.

[0129] As the polyhydric alcohol, there can be mentioned, for example, aliphatic diols (e.g., linear aliphatic diols in which the number of carbon atoms in the main chain portion is 7 to 20). As the aliphatic diol, there can be mentioned, for example, 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, 1,14-eicosanediol, etc. Among these, as the aliphatic diol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol are preferable.

[0130] As the polyhydric alcohol, there can be mentioned, for example, aliphatic diols (e.g., linear aliphatic diols in which the number of carbon atoms in the main chain portion is 7 to 20). As the aliphatic diol, there can be mentioned, for example, 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, 1,14-eicosanediol, etc. Among these, as the aliphatic diol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol are preferable.

[0131] The polyhydric alcohol can be used singly or in combination of two or more.

[0132] Here, the content of the aliphatic diol can be set to 80 mol% or more, and preferably 90 mol% or more, with respect to the polyol.

[0133] The melting temperature of the crystalline polyester resin is preferably 50°C or higher and 100°C or lower, more preferably 55°C or higher and 90°C or lower, and further preferably 60°C or higher and 85°C or lower.

[0134] Note that the melting temperature is obtained from a DSC curve obtained by differential scanning calorimetry (DSC) by the "melting peak temperature" described in the method for calculating the melting temperature of JIS K 7121-1987 "Method of testing transition temperatures of plastics".

[0135] The weight average molecular weight (Mw) of the crystalline polyester resin is preferably 6,000 or more and 35,000 or less.

[0136] The crystalline polyester resin is obtained, for example, by a publicly known production method, similarly to the amorphous polyester resin.

[0137] From the viewpoint of the rubbing resistance of the image, the weight average molecular weight (Mw) of the 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, and particularly preferably 25,000 or more and 60,000 or less. The number average molecular weight (Mn) of the polyester resin is preferably 2,000 or more and 100,000 or less. The molecular weight distribution Mw / Mn of the polyester resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less.

[0138] The weight average molecular weight and the number average molecular weight of the polyester resin are measured by gel permeation chromatography (GPC). In the GPC-based molecular weight measurement, GPC HLC-8120GPC manufactured by Tosoh Corporation is used as a measuring device, a column TSKgel Super HM-M (15 cm) manufactured by Tosoh Corporation is used, and tetrahydrofuran (THF) solvent is used. The weight average molecular weight and the number average molecular weight are calculated from the measurement results using a molecular weight calibration curve prepared from monodisperse polystyrene standard samples.

[0139] From the viewpoint of the dispersibility of the basic dye in the particles, the dispersibility of the resin fine particles, and the color development density, the polyester resin preferably has an acid group, and more preferably has a carboxyl group.

[0140] From the viewpoint of the dispersibility of the basic dye in the particles, the dispersibility of the resin fine particles, and the color development density, the acid value of the polyester resin is preferably 1 mgKOH / g or more and 50 mgKOH / g or less, more preferably 2 mgKOH / g or more and 30 mgKOH / g or less, and particularly preferably 5 mgKOH / g or more and 18 mgKOH / g or less.

[0141] As a method for measuring the acid value, the measurement was performed in accordance with JIS K0070 (1992)

[0142] The resin fine particles can contain one polyester resin alone, or two or more kinds in combination.

[0143] From the viewpoints of the dispersibility of the basic dye in the resin fine particles, the dispersibility of the resin fine particles, and the color development density, the content of the polyester resin relative to the entire resin fine particles is preferably 50% by mass or more and 99% by mass or less, more preferably 60% by mass or more and 98% by mass or less, and further preferably 70% by mass or more and 95% by mass or less.

[0144] (Basic dye)

[0145] The resin fine particles of the present embodiment contain a basic dye.

[0146] The basic dye refers to a dye having a basic group, and is preferably an ionic dye in which a cationic portion is a color developing group.

[0147] Note that, in the present embodiment, "pigment" refers to a colorant having a solubility of less than 0.1 g in 100 g of water at 23°C and a solubility of less than 0.1 g in 100 g of cyclohexanone at 23°C, and "dye" refers to a colorant having a solubility of 0.1 g or more in 100 g of water at 23°C or a solubility of 0.1 g or more in 100 g of cyclohexanone at 23°C.

[0148] As the basic dye, for example, dyes such as diazine-based dyes, oxazine-based dyes, thiazine-based dyes, azo-based dyes, anthraquinone-based dyes, xanthene-based dyes, triarylmethane-based dyes, phthalocyanine-based dyes, auramine-based dyes, acridine-based dyes, and methine-based dyes can be given. Specifically, the following dyes can be given. Note that, for example, "Basic Red 2" and the like are also referred to as "C.I. Basic Red 2" and the like.

[0149] Diazine-based dyes such as Basic Red 2, 5, 6, 10, Basic Blue 13, 14, 16, Basic Violet 5, 6, 8, 12, and Basic Yellow 14;

[0150] Oxazine-based dyes such as Basic Blue 3, 6, 10, 12, and 74;

[0151] Thiazine-based dyes such as Basic Blue 9, 17, 24, 25, and Basic Green 5;

[0152] Basic Red 18, 22, 23, 24, 29, 30, 31, 32, 34, 38, 39, 46, 51, 53, 54, 55, 62, 64, 76, 94, 111, 118, Basic Blue 41, 53, 54, 55, 64, 65, 66, 67, 162, Basic Violet 18, 36, Basic Yellow 15, 19, 24, 25, 28, 29, 38, 39, 49, 51, 57, 62, 73, Basic Orange 1, 2, 24, 25, 29, 30, 33, 54, 69, and the like azo-based dyes;

[0153] Basic Blue 22, 44, 47, 72, and the like anthraquinone-based dyes;

[0154] Basic Red 1, 1:1, 3, 4, 8, 11, Basic Violet 10, 11, 11:1, and the like xanthene-based dyes;

[0155] Basic Red 9, Basic Blue 1, 2, 5, 7, 8, 11, 15, 18, 20, 23, 26, 35, 81, Basic Violet 1, 2, 3, 4, 14, 23, Basic Green 1, 4, and the like triarylmethane-based dyes;

[0156] Basic Blue 140, and the like phthalocyanine-based dyes;

[0157] Basic Yellow 2, 3, 37, and the like metal amine-based dyes;

[0158] Basic Yellow 5, 6, 7, 9, Basic Orange 4, 5, 14, 15, 16, 17, 18, 19, 23, and the like acridine-based dyes;

[0159] Basic Red 12, 13, 14, 15, 27, 28, 37, 52, 90, Basic Yellow 11, 13, 20, 21, 52, 53, Basic Orange 21, 22, Basic Violet 7, 15, 16, 20, 21, 22, and the like methine-based dyes.

[0160] In addition, as the basic dye, a basic fluorescent dye can be used. In the case of the resin fine particles of the present embodiment, if a basic fluorescent dye is used, a high fluorescent density image can be obtained, in order to obtain an image with a high color development density.

[0161] In addition, as the basic fluorescent dye, a cationic group is particularly preferable from the viewpoints of color development density and fluorescent density.

[0162] As the cationic group, an onium group is preferable from the viewpoint of fluorescent intensity, an ammonium group, an iminium group, or a pyridinium group is more preferable, an ammonium group is further preferable, and a quaternary ammonium group is particularly preferable.

[0163] In addition, the basic fluorescent dye can have only one cationic group, or can have two or more cationic groups. From the viewpoint of fluorescence intensity, it is preferable to have one or more but four or less, more preferably one or two, and particularly preferably only one.

[0164] As the basic fluorescent dye, from the viewpoint of fluorescence intensity, 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, 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 can be mentioned, 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 can be mentioned.

[0165] The basic fluorescent dye preferably has a fluorescence peak wavelength at a spectral reflectance of 380 nm or more and 760 nm or less. Among them, the fluorescence peak wavelength can be appropriately selected depending on the color to be expressed. For example, in the case of expressing a fluorescence peak, more preferably, it has a fluorescence peak wavelength at a spectral reflectance of 560 nm or more and 670 nm or less, and particularly preferably, it has a fluorescence peak wavelength at a spectral reflectance of 580 nm or more and 650 nm or less.

[0166] In addition, with respect to the basic fluorescent dye, the value of the spectral reflectance at the above-mentioned fluorescence peak wavelength is preferably 100% or more, more preferably 105% or more, and particularly preferably 110% or more from the viewpoint of the graininess of the image.

[0167] The resin microparticles can contain one kind of basic dye alone, or two or more kinds in combination.

[0168] The content of the basic dye, from the viewpoint of the dispersibility of the basic dye in the resin microparticles, the dispersibility of the resin microparticles, and the color development density, is preferably 0.1% by mass or more and 20% by mass or less, more preferably 0.3% by mass or more and 15% by mass or less, and particularly preferably 0.5% by mass or more and 10% by mass or less, with respect to the entire resin microparticles.

[0169] In addition, the content of the basic dye in the resin fine particles is preferably 0.1 parts by mass or more and 20 parts by mass or less, more preferably 0.3 parts by mass or more and 15 parts by mass or less, and particularly preferably 0.5 parts by mass or more and 10 parts by mass or less, relative to 100 parts by mass of the polyester resin in the resin fine particles, from the viewpoint of the dispersibility of the basic dye in the resin fine particles, the dispersibility of the resin fine particles, and the color development density.

[0170] The resin fine particles can contain components other than the polyester resin and the basic dye.

[0171] Examples include alkali and surfactants at the time of production, and colorants other than the basic dye, as described later.

[0172] The total content of the polyester resin and the basic dye in the resin fine particles is preferably 70% by mass or more, more preferably 80% by mass or more, and particularly preferably 90% by mass or more and 100% by mass or less, relative to the entire resin fine particles, from the viewpoint of the dispersibility of the basic dye in the resin fine particles, the dispersibility of the resin fine particles, and the color development density.

[0173] (Method for producing resin fine particles)

[0174] The method for producing the resin fine particles of the present embodiment is not particularly limited, and a publicly known method can be used. Among them, the method for producing the resin fine particles of the present embodiment is preferably a method including: a dissolving or melting step of bringing an oily mixture of at least a polyester resin, an alkali, and a basic dye to a dissolved state or a molten state while imparting a shear force thereto; and an emulsifying step of adding a surfactant and an aqueous medium to emulsify while imparting a shear force to the dissolved or molten oily mixture.

[0175] -Dissolving or melting step-

[0176] The method for producing the resin fine particles of the present embodiment preferably includes a dissolving or melting step, that is, a step of bringing an oily mixture of at least a polyester resin, an alkali, and a basic dye to a dissolved state or a molten state while imparting a shear force thereto.

[0177] In the dissolving or melting step, one kind of alkali can be used alone, or two or more kinds of alkalis can be used in combination.

[0178] In the dissolving or melting step, a surfactant can be used. One kind of surfactant can be used alone, or two or more kinds of surfactants can be used in combination.

[0179] In the above-mentioned dissolving or melting step, the polyester resin (amorphous resin and crystalline resin), the base, and the basic dye are dissolved and mixed using an organic solvent, or are melt-mixed by heat without using an organic solvent. Note that the "organic solvent" in the present embodiment is an organic solvent that dissolves the resin. An organic solvent other than an aqueous medium such as an alcohol can also be used in combination.

[0180] The mixing temperature in the above-mentioned dissolving or melting step is not particularly limited, and is preferably 20°C to 150°C, and more preferably 35°C to 100°C from the viewpoint of uniformity of mixing and emulsification dispersibility in the emulsification step.

[0181] In addition, in order to easily perform mixing, the melting temperature in the above-mentioned melting step is preferably a temperature of the glass transition temperature (Tg) of the amorphous resin or more, and more preferably a temperature of "Tg of the amorphous resin + 5°C" or more.

[0182] As the mechanism that imparts a shearing force while being in a dissolved state or a molten state in the above-mentioned dissolving or melting step, there is no particular limitation, and a publicly known mixing device or the like can be used. As the mixing device, a mixing tank equipped with a stirrer, a roll mill, a kneader, a pressurized kneader, a Banbury mixer, a labo-plastomill, an extruder of a single screw or a twin screw, or the like can be cited.

[0183] Among them, a mixing tank equipped with a stirrer, an extruder, or a kneader can be cited as preferable.

[0184] As the base used in the above-mentioned dissolving or melting step, specifically, a hydroxide of an alkali metal such as lithium, sodium, or potassium, or an oxide or a hydroxide of an alkaline earth metal such as magnesium or calcium, or the like can be cited. Among them, from the viewpoint of fixability and transferability of the thermoplastic resin particles, a hydroxide of an alkali metal or an alkaline earth metal is preferable, a hydroxide of an alkali metal is more preferable, potassium hydroxide or sodium hydroxide is further preferable, and sodium hydroxide is particularly preferable.

[0185] As the surfactant used in the above-mentioned dissolving or melting step, various surfactants such as anionic surfactants, amphoteric surfactants, cationic surfactants, and nonionic surfactants can be cited. Among them, from the viewpoint of fixability and transferability of the thermoplastic resin particles, an anionic surfactant is preferable, an anionic surfactant of a sulfate type or a sulfonic acid type is more preferable, and an anionic surfactant of a sulfonic acid type is particularly preferable.

[0186] As the anionic surfactant, any one of a carboxylic acid type, a sulfate type, a sulfonic acid type, and a phosphate type can be used. Examples of the anionic surfactant include a fatty acid salt, a rosin acid salt, a naphthenic acid salt, an ether carboxylic acid salt, an alkenyl succinic acid salt, a primary alkyl sulfate salt, a secondary alkyl sulfate salt, an alkyl polyoxyethylene sulfate salt, an alkylphenyl polyoxyethylene sulfate salt, a monoglyceride sulfate salt, an acylamino sulfate salt, a sulfated oil, a sulfated fatty acid alkyl ester, an a-olefin sulfonic acid salt, a secondary paraffin sulfonic acid salt, an a-sulfofatty acid salt, an acylhydroxyethyl sulfonic acid salt, a dialkyl sulfosuccinic acid salt, an alkylbenzenesulfonic acid salt, an alkylnaphthalenesulfonic acid salt, an alkyl diphenyl ether disulfonic acid salt, a petroleum sulfonic acid salt, a lignin sulfonic acid salt, an alkyl phosphate salt, an alkyl polyoxyethylene phosphate salt, an alkylphenyl polyoxyethylene phosphate salt, a perfluoroalkyl carboxylic acid salt, a perfluoroalkyl sulfonic acid salt, and a perfluoroalkyl phosphate ester.

[0187] The amphoteric surfactant refers to a surfactant having both a cationic group and an anionic group in the molecular structure, and refers to a substance having no electric charge as a whole molecule although there is a separation of electric charges in the molecular structure.

[0188] As the amphoteric surfactant, examples include N-alkyl nitrilo triacetates, N-alkyldimethyl betaines, N-alkyloxy methyl-N,N-diethyl betaines, N-alkylsulfo betaines, N-alkylhydroxysulfo betaines, lecithin, and perfluoroalkylsulfonamido alkyl betaines.

[0189] As the cationic surfactant, examples include N-acyl amine salts, quaternary ammonium salts, and imidazolium salts, and specifically, examples include fatty acid polyethylene polyamide, amide, alkyltrimethylammonium salt, dialkyldimethylammonium salt, alkyl dimethyl benzyl ammonium salt, alkyl pyridinium salt, acylaminoethyl methyldiethyl ammonium salt, acylamino propyl dimethyl benzyl ammonium salt, acylamino propyl dimethyl hydroxyethyl ammonium salt, acylamino ethyl pyridinium salt, diacylamino ethyl ammonium salt, diacyloxy ethyl methyl hydroxyethyl ammonium salt, alkyl oxy methyl pyridinium salt, and 1-acylamino ethyl-2-alkyl imidazolium salt.

[0190] As the nonionic surfactant, examples include esters of polyhydric alcohols and fatty acids, ethers such as polyoxyethylene alkyl ether or polyoxyethylene alkyl phenyl ether, polyoxyethylene polyoxypropylene glycol, fatty acid to which ethylene oxide is added, polyhydric alcohol fatty acid ester to which ethylene oxide is added, fatty acid alkanolamide to which an amide bond is added between a hydrophobic group and a hydrophilic group, and alkyl polyglycoside.

[0191] Note that, as the anionic surfactant, the amphoteric surfactant, the cationic surfactant, and the nonionic surfactant, not limited to the above-mentioned substances, publicly known anionic surfactants, amphoteric surfactants, cationic surfactants, nonionic surfactants, and the like other than the above can also be used.

[0192] The amount of the base used in the dissolving or melting step is preferably 0.001 parts by mass to 10 parts by mass, more preferably 0.005 parts by mass to 5 parts by mass, further preferably 0.1 parts by mass to 2 parts by mass, and particularly preferably 0.01 parts by mass to 1 part by mass, relative to 100 parts by mass of the polyester resin. When the amount is within the above range, the emulsification and dispersion are more excellent, and the transferability of the thermoplastic resin particles is more excellent.

[0193] The amount of the surfactant used in the dissolving or melting step is preferably 0.1 parts by mass to 20 parts by mass, more preferably 0.5 parts by mass to 10 parts by mass, and further preferably 1 part by mass to 5 parts by mass, relative to 100 parts by mass of the polyester resin. When the amount is within the above range, the emulsification and dispersion are more excellent, and the transferability of the thermoplastic resin particles is more excellent.

[0194] -Emulsification Step-

[0195] The method for producing the resin fine particles of the present embodiment includes an emulsification step in which the surfactant and the aqueous medium are added while imparting a shear force to the above-mentioned oil mixture that is dissolved or melted to emulsify and thereby obtain a dispersion liquid of the above-mentioned resin fine particles.

[0196] Further, from the viewpoint of the dispersibility of the basic dye in the resin fine particles, the dispersibility of the resin fine particles, and the color development density, the pH of the above-mentioned dispersion liquid is preferably 6 or higher and 12 or lower, and more preferably 7 or higher and 11 or lower.

[0197] The emulsification and dispersion in the above-mentioned emulsification step is preferably performed by phase inversion emulsification. That is, in the above-mentioned emulsification step, it is preferable to continuously or sequentially add the water-based medium to the above-mentioned dissolving mixture or the melting mixture to perform emulsification and dispersion, more preferable to sequentially add the water-based medium to the above-mentioned dissolving mixture or the melting mixture in two or more times to perform emulsification and dispersion, and particularly preferable to sequentially add the water-based medium to the above-mentioned dissolving mixture or the melting mixture in three or more times to perform emulsification and dispersion.

[0198] The emulsification and dispersion in the above-mentioned emulsification step is performed while imparting a shear force to the above-mentioned dissolving mixture or the melting mixture. Further, a mixing tank equipped with a stirrer, an extruder, or a kneader is preferably used in the above-mentioned emulsification step. For example, it is preferable to impart a shear force to the above-mentioned dissolving mixture or the melting mixture by a screw of an extruder, a blade of a kneader, or the like.

[0199] As the surfactant, the above-mentioned surfactants can be mentioned.

[0200] The amount of the surfactant used in the emulsification step is preferably 0.1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass, and further preferably 1 to 5 parts by mass, relative to 100 parts by mass of the polyester resin. When the amount is within the above range, the emulsification dispersibility is more excellent, and the transferability when used as a toner is more excellent.

[0201] As the aqueous medium used in the present embodiment, water such as distilled water, ion-exchange water, alcohols such as ethanol and methanol, and the like can be given. Among these, ethanol, water, and particularly distilled water and ion-exchange water are preferred. These media can be used singly or in combination of two or more.

[0202] In addition, an organic solvent having water miscibility can be contained in the aqueous medium, but it is preferred not to be contained in the emulsification step.

[0203] The amount of the aqueous medium used in the emulsification step is not particularly limited, and can be appropriately selected depending on the solid content concentration of the obtained resin microparticle dispersion liquid.

[0204] The solid content concentration of the obtained resin microparticle dispersion liquid can be appropriately selected as needed, and is preferably 1% by mass or more and 60% by mass or less, more preferably 5% by mass or more and 50% by mass or less, and particularly preferably 10% by mass or more and 50% by mass or less.

[0205] The emulsification temperature in the emulsification step is not particularly limited, and is preferably 20°C to 150°C, and more preferably 30°C to 100°C from the viewpoint of emulsification dispersibility in the emulsification step.

[0206] In addition, the emulsification temperature in the emulsification step is preferably a temperature of the glass transition temperature (Tg) of the amorphous resin or more, and more preferably a temperature of "Tg of the amorphous resin + 5°C" or more, in the case of using a molten mixture.

[0207] The emulsification mechanism used in the emulsification step is not particularly limited, and a publicly known disperser or emulsifier can be used, and a mixing tank provided with a stirrer, a kneader, a homogenizer, a homomixer, a pressure kneader, an extruder, a media disperser, an extruder of a single screw or a twin screw, and the like can be given.

[0208] Among these, a mixing tank provided with a stirrer, an extruder, or a kneader is preferred.

[0209] The emulsifier used in the emulsification step is not particularly limited between batch type and continuous type, and a twin screw extruder can be preferably given.

[0210] The method for producing the resin fine particles of the present embodiment can include other processes than the above-mentioned dissolving or melting process and the above-mentioned emulsifying process.

[0211] As the other processes, there is no particular limitation, and known processes can be performed as needed, and processes such as a process of cooling the obtained resin fine particle dispersion liquid can be cited.

[0212] In addition, the resin fine particles can be separated from the resin fine particle dispersion liquid by filtration or the like as needed, dried, and obtained.

[0213] <Thermoplastic resin particles>

[0214] The first embodiment of the thermoplastic resin particles of the present embodiment is thermoplastic resin particles containing a polyester resin and a basic dye, in which, in a cross section of the above-mentioned thermoplastic resin particles, the average distance X between adjacent regions containing the above-mentioned basic dye D satisfies the following formula L:

[0215] 0.01 x D 50v ≤ X D ≤ 0.4 x D 50v Formula L

[0216] Note that D 50v represents the volume average particle diameter of the thermoplastic resin particles.

[0217] In addition, the second embodiment of the thermoplastic resin particles of the present embodiment is thermoplastic resin particles in which the resin fine particles of the present embodiment are at least coagglomerated.

[0218] Note that, in the present specification, in the case where it is referred to as "the thermoplastic resin particles of the present embodiment" or simply "the thermoplastic resin particles" without particular mention, it is described with respect to both the above-mentioned first embodiment and the above-mentioned second embodiment.

[0219] The present inventors have conducted detailed studies, and as a result, it has been found that, for the existing thermoplastic resin particles, the dispersibility of the resin fine particles containing a basic dye is not sufficient, and sometimes the color development density becomes low.

[0220] The thermoplastic resin particles of the present embodiment can obtain an image with a high color development density by the above-mentioned constitution. The reason for this is not certain, but it is presumed based on the reasons shown below.

[0221] The coagulation-merged resin fine particles contain a polyester resin and a basic dye, and have a volume average particle diameter of 0.05 μm or more and 1 μm or less. The concentration ratio of the basic dye in the center-of-gravity portion of the resin fine particles with respect to the surface layer portion of the resin fine particles to a depth of 10 nm or less from the surface of the resin fine particles is 0.8 or more. Alternatively, the average distance X between adjacent regions containing the basic dye in a cross section of the thermoplastic resin particles is 0.1 μm or more and 1 μm or less. D Satisfying formula L, thereby, a thermoplastic resin particle having excellent dispersibility of resin fine particles containing a basic dye, less dye unevenness, and a high color density image can be obtained.

[0222] The thermoplastic resin particle of the present embodiment is preferably used as a thermoplastic fluorescent resin particle.

[0223] In addition, the thermoplastic resin particle of the present embodiment is preferably used as a toner for electrostatic image development.

[0224] The thermoplastic resin particle contains a polyester resin, a basic dye, and, as necessary, an anti-adhesive agent and other additives, and preferably contains a polyester resin, a basic dye, and an anti-adhesive agent.

[0225] In the first embodiment of the thermoplastic resin particle of the present embodiment, the average distance X between adjacent regions containing the basic dye in a cross section of the thermoplastic resin particle is 0.1 μm or more and 1 μm or less. D Satisfying the following formula L:

[0226] 0.01 x D 50v ≤ X D ≤ 0.4 x D 50v Formula L

[0227] Note that D 50v represents the volume average particle diameter of the thermoplastic resin particle.

[0228] In addition, in the second embodiment of the thermoplastic resin particle of the present embodiment, from the aspect of color density, the average distance X between adjacent regions containing the basic dye in a cross section of the thermoplastic resin particle is preferably 0.1 μm or more and 1 μm or less. D Satisfying formula L.

[0229] The average distance X between adjacent regions containing the basic dye in a cross section of the thermoplastic resin particle is 0.1 μm or more and 1 μm or less. D The measurement of the average distance X between adjacent regions containing the basic dye in a cross section of the thermoplastic resin particle is performed by the following method.

[0230] A sample was prepared by embedding the thermoplastic resin particles in a resin. A cross section was prepared from the prepared sample using a microtome. The position of the dye was determined from the cross section observation. As the analysis method for determining the position of the region containing the basic dye, a method of observing after staining using an electron microscope, a method of performing element mapping using energy dispersive X-ray analysis (EDX), time-of-flight secondary ion mass spectrometry (TOF-SIMS), Auger electron spectroscopy (AES), and the like can be used. In addition, the distance between the regions containing the basic dye was measured as the distance from the center of gravity of each region of the basic dye. With respect to the average distance X between the regions described above D , the average value of the distance between the regions containing the basic dye in one thermoplastic resin particle was determined, and cross section observation was performed on 50 or more thermoplastic resin particles, and the average was used.

[0231] In addition, in the first embodiment of the thermoplastic resin particles of the present embodiment, from the aspect of color development density, the average distance X between the adjacent regions containing the basic dye in the cross section of the thermoplastic resin particles described above D satisfies the following formula L1, and more preferably satisfies the following formula L2.

[0232] 0.03 x D 50v ≤ X D ≤ 0.30 x D 50v Formula L1

[0233] 0.05 x D 50v ≤ X D ≤ 0.20 x D 50v Formula L2

[0234] Note that D 50v represents the volume average particle diameter of the thermoplastic resin particles.

[0235] In addition, in the second embodiment of the thermoplastic resin particles of the present embodiment, from the aspect of color development density, the average distance X between the adjacent regions containing the basic dye in the cross section of the thermoplastic resin particles described above D more preferably satisfies the above formula L1, and particularly preferably satisfies the above formula L2.

[0236] From the aspect of color development density, in the thermoplastic resin particles of the present embodiment, the average distance X between the adjacent regions containing the basic dye in the cross section of the thermoplastic resin particles described above D is preferably 0.05 μm or more and 3.0 μm or less, more preferably 0.08 μm or more and 2.5 μm or less, and particularly preferably 0.2 μm or more and 1.0 μm or less.

[0237] In addition, the first embodiment of the thermoplastic resin particles of the present embodiment is preferably thermoplastic resin particles in which the resin fine particles of the present embodiment are at least coaggregated.

[0238] The preferable modes of the polyester resin and the basic dye contained in the thermoplastic resin particles of the present embodiment are the same as those described for the resin fine particles of the present embodiment.

[0239] With respect to the thermoplastic resin particles of the present embodiment, from the viewpoints of the dispersibility of the basic dye in the resin fine particles, the dispersibility of the resin fine particles, and the color development density, in the cross section of the above thermoplastic resin particles, the concentration ratio of the basic dye in the central portion of the region containing the above basic dye with respect to the surface layer portion of the region containing the above basic dye to a depth of 10 nm or less from the surface is preferably 0.8 or greater, more preferably 0.85 or greater, further preferably 0.9 or greater, and particularly preferably 0.92 or greater to 1.0 or less.

[0240] With respect to the concentration ratio of the basic dye in the region containing the basic dye in the cross section of the thermoplastic resin particles, the measurement of the concentration ratio of the basic dye in the central portion of the resin fine particles with respect to the surface layer portion of the resin fine particles to a depth of 10 nm or less from the surface is similarly performed in the above resin fine particles. In addition, the confirmation of the region containing the basic dye can also refer to the measurement of the average distance X between adjacent regions containing the basic dye in the cross section of the above thermoplastic resin particles. D

[0241] - Colorants other than basic dyes -

[0242] The thermoplastic resin particles of the present embodiment can contain colorants other than basic dyes (hereinafter referred to as "other colorants").

[0243] As the other colorants, publicly known colorants can be used.

[0244] The other colorants are preferably colorants that do not exhibit fluorescence in the visible light region.

[0245] In addition, the other colorants can be pigments or dyes, and are preferably pigments.

[0246] ​As other colorants, specifically, mention can be made of, for example, C.I. Pigment Red 1, C.I. Pigment Red 2, C.I. Pigment Red 3, C.I. Pigment Red 4, C.I. Pigment Red 5, C.I. Pigment Red 6, C.I. Pigment Red 7, C.I. Pigment Red 8, C.I. Pigment Red 9, C.I. Pigment Red 10, C.I. Pigment Red 11, C.I. Pigment Red 12, C.I. Pigment Red 14, C.I. Pigment Red 15, C.I. Pigment Red 16, C.I. Pigment Red 17, C.I. Pigment Red 18, C.I. Pigment Red 21, C.I. Pigment Red 22, C.I. Pigment Red 23, C.I. Pigment Red 31, C.I. Pigment Red 32, C.I. Pigment Red 38, C.I. Pigment Red 41, C.I. Pigment Red 48, C.I. Pigment Red 48:1, C.I. Pigment Red 48:2, C.I. Pigment Red 48:3, C.I. Pigment Red 48:4, C.I. Pigment Red 49, C.I. Pigment Red 52, C.I. Pigment Red 53:1, C.I. Pigment Red 54, C.I. Pigment Red 57:1, C.I. Pigment Red 58, C.I. Pigment Red 60:1, C.I. Pigment Red 63, C.I. Pigment Red 64:1, C.I. Pigment Red 68, C.I. Pigment Red 81:1, C.I. Pigment Red 81:4, C.I. Pigment Red 83, C.I. Pigment Red 88, C.I. Pigment Red 89, C.I. Pigment Red 112, C.I. Pigment Red 114, C.I. Pigment Red 122, C.I. Pigment Red 123, C.I. Pigment Red 144, C.I. Pigment Red 146, C.I. Pigment Red 149, C.I. Pigment Red 150, C.I. Pigment Red 166, C.I. Pigment Red 170, C.I. Pigment Red 176, C.I. Pigment Red 177, C.I. Pigment Red 178, C.I. Pigment Red 179, C.I. Pigment Red 184, C.I. Pigment Red 185, C.I. Pigment Red 187, C.I. Pigment Red 202, C.I. Pigment Red 206, C.I. Pigment Red 207, C.I. Pigment Red 208, C.I. Pigment Red 209, C.I. Pigment Red 210, C.I. Pigment Red 220, C.I. Pigment Red 221, C.I. Pigment Red 238, C.I. Pigment Red 242, C.I. Pigment Red 245, C.I. Pigment Red 253, C.I. Pigment Red 254, C.I. Pigment Red 255, C.I. Pigment Red 256, C.I. Pigment Red 258, C.I. Pigment Red 264, C.I. Pigment Red 266, C.I. Pigment Red 269, etc., a magenta pigment of C.I. Pigment Violet 19, C.I. Solvent Red 1, C.I. Solvent Red 3, C.I. Solvent Red 8, C.I. Solvent Red 23, C.I. Solvent Red 24, C.I. Solvent Red 25, C.I. Solvent Red 27, C.I. Solvent Red 30, C.I. Solvent Red 49, C.I. Solvent Red 52, C.I. Solvent Red 58, C.I. Solvent Red 63, C.I.Solvent Red 81, C.I. Solvent Red 82, C.I. Solvent Red 83, C.I. Solvent Red 84, C.I. Solvent Red 100, C.I. Solvent Red 109, C.I. Solvent Red 111, C.I. Solvent Red 121, C.I. Solvent Red 122, C.I. Disperse Red 9, C.I. Basic Red 1, C.I. Basic Red 2, C.I. Basic Red 9, C.I. Basic Red 12, C.I. Basic Red 13, C.I. Basic Red 14, C.I. Basic Red 15, C.I. Basic Red 17, C.I. Basic Red 18, C.I. Basic Red 22, C.I. Basic Red 23, C.I. Basic Red 24, C.I. Basic Red 27, C.I. Basic Red 29, C.I. Basic Red 32, C.I. Basic Red 34, C.I. Basic Red 35, C.I. Basic Red 36, C.I. Basic Red 37, C.I. Basic Red 38, C.I. Basic Red 39, C.I. Basic Red 40, and the like, red dyes such as Fast Red 4R, Lithol Red, Pyrazolone Red, Watching Red, calcium salt, Lake Red D, Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B, carbon black, chrome yellow, Hansa yellow, benzidine yellow, vat yellow, quinoline yellow, pigment yellow, Permanent Orange GTR, Pyrazolone Orange, Thiosulfone Orange, Brilliant Carmine 3B, Brilliant Carmine 6B, DuPont Oil Red, Lake Red C, Aniline Blue, Thionine Blue, Oil-Soluble Blue, Methylene Blue Chloride, Phthalocyanine Blue, Pigment Blue, Phthalocyanine Green, Malachite Green, and the like.

[0247] The other colorant can be appropriately selected depending on the color desired. For example, in the case where a fluorescent powder is desired to be expressed, a red pigment is considered to be included.

[0248] The other colorant can be used alone or in combination of two or more. In the case of combination, two or more kinds of colorants having different maximum absorption wavelengths in the visible light region are preferably combined.

[0249] The other colorant can be used as a colorant subjected to surface treatment as needed or in combination with a dispersant. In addition, the colorant can be combined with two or more kinds.

[0250] The content of the other colorant is preferably 0.1% by mass or more and 30% by mass or less, more preferably 0.2% by mass or more and 15% by mass or less, and particularly preferably 0.3% by mass or more and 5% by mass or less, relative to the entire thermoplastic resin particles, from the aspects of fluorescence intensity and color tone.

[0251] From the aspects of fluorescence intensity and hue, the ratio (WB / WA) of the content WB of the other colorant to the content WA of the basic dye in the thermoplastic resin particles is preferably 0.5 or more and 10 or less, more preferably 0.8 or more and 5 or less, and particularly preferably 0.8 or more and 1.5 or less.

[0252] - Other binding resins -

[0253] The thermoplastic resin particles of the present embodiment can contain a binding resin other than the polyester resin contained in the above-mentioned resin fine particles (hereinafter referred to as "other binding resin").

[0254] As the other binding resin, for example, a vinyl-based resin composed of a homopolymer of a monomer such as a styrene-based monomer (e.g., styrene, p-chlorostyrene, α-methylstyrene, etc.), a (meth)acrylate-based monomer (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.), an ethylenically unsaturated nitrile-based monomer (e.g., acrylonitrile, methacrylonitrile, etc.), a vinyl ether-based monomer (e.g., vinyl methyl ether, vinyl isobutyl ether, etc.), a vinyl ketone-based monomer (e.g., vinyl methyl ketone, vinyl ethyl ketone, vinyl isopropyl ketone, etc.), an olefin-based monomer (e.g., ethylene, propylene, butadiene, etc.), or a copolymer of two or more of these monomers can be given.

[0255] As the other binding resin, for example, a polyester resin other than the polyester resin contained in the above-mentioned resin fine particles, an epoxy resin, a polyurethane resin, a polyamide resin, a cellulose resin, a polyether resin, a modified rosin, and the like, a mixture of these and the above-mentioned vinyl-based resin, or a graft polymer obtained by polymerizing a vinyl-based monomer in the presence of these can also be given.

[0256] These other binding resins can be used singly or in combination of two or more.

[0257] From the aspect of the rubbing resistance of the image, the weight average molecular weight (Mw) of the other binding resin is preferably 5,000 or more and 1,000,000 or less, more preferably 7,000 or more and 500,000 or less, and particularly preferably 25,000 or more and 60,000 or less. The number average molecular weight (Mn) of the other binding resin is preferably 2,000 or more and 100,000 or less. The molecular weight distribution Mw / Mn of the other binding resin is preferably 1.5 or more and 100 or less, and more preferably 2 or more and 60 or less.

[0258] The weight average molecular weight and the number average molecular weight of the other binding resins are measured by gel permeation chromatography (GPC). In the GPC-based molecular weight measurement, GPC·HLC-8120GPC manufactured by Tosoh Corporation is used as a measuring device, column·TSKgel Super HM-M (15 cm) manufactured by Tosoh Corporation is used, and tetrahydrofuran (THF) solvent is used. The weight average molecular weight and the number average molecular weight are calculated from the measurement results using a molecular weight calibration curve prepared from monodisperse polystyrene standard samples.

[0259] The total content of the polyester resin and the other binding resins contained in the above resin fine particles with respect to the entire thermoplastic resin particles is preferably 40% by mass or more and 95% by mass or less, more preferably 50% by mass or more and 90% by mass or less, and further preferably 60% by mass or more and 85% by mass or less.

[0260] - Anti-adhesion agent -

[0261] As the anti-adhesion agent, for example, a hydrocarbon wax; a natural wax such as carnauba wax, rice bran wax, candelilla wax; a synthetic or mineral / petroleum-based wax such as montan wax; an ester-based wax such as a fatty acid ester, montanic acid ester; and the like can be given. The anti-adhesion agent is not limited thereto.

[0262] The melting temperature of the anti-adhesion agent is preferably 50°C or higher and 110°C or lower, and more preferably 60°C or higher and 100°C or lower.

[0263] The melting temperature is calculated from the "melting peak temperature" described in the method for calculating the melting temperature of JIS K7121-1987 "Plastic Transition Temperature Measurement Method" from the DSC curve obtained by differential scanning calorimetry (DSC).

[0264] The content of the anti-adhesion agent with respect to the entire thermoplastic resin particles is preferably 1% by mass or more and 20% by mass or less, and more preferably 5% by mass or more and 15% by mass or less.

[0265] - Other additives -

[0266] As the other additives, for example, a magnetic body, a charge control agent, an inorganic powder, and the like known additives can be given. These additives are contained in the thermoplastic resin particles as an internal additive.

[0267] - Characteristics of the thermoplastic resin particles and the like -

[0268] The thermoplastic resin particles can be thermoplastic resin particles of a single layer structure, or can be thermoplastic resin particles (core-shell type particles) of a so-called core-shell structure composed of a core (core particle) and a coating layer (shell layer) that coats the core. The thermoplastic resin particles of the core-shell structure are composed of, for example, a core that contains a binding resin and, as needed, a colorant, an anti-adhesion agent, and the like, and a coating layer that contains a binding resin.

[0269] The volume average particle diameter (Dv) of the thermoplastic resin particles is preferably 2 μm or more and 10 μm or less, more preferably 4 μm or more and 8 μm or less, and particularly preferably 4 μm or more and 7 μm or less. 50v The volume average particle diameter (Dv) of the thermoplastic resin particles is preferably 2 μm or more and 10 μm or less, more preferably 4 μm or more and 8 μm or less, and particularly preferably 4 μm or more and 7 μm or less.

[0270] The volume average particle diameter of the thermoplastic resin particles is measured using a Coulter Multisizer II (manufactured by Beckman Coulter) with an electrolyte solution of ISOTON-II (manufactured by Beckman Coulter).

[0271] At the time of measurement, 0.5 mg or more and 50 mg or less of the sample to be measured is added to 2 mL of a 5% by mass aqueous solution of a surfactant (preferably sodium alkylbenzenesulfonate) as a dispersant. This is added to 100 mL or more and 150 mL or less of the electrolyte solution.

[0272] The electrolyte solution in which the sample is suspended is dispersed for 1 minute using an ultrasonic disperser, and the Coulter Multisizer II is used to measure the particle diameter using a 100-μm aperture with respect to particles in the range of 2 μm or more and 60 μm or less. The number of particles sampled is 50,000.

[0273] The cumulative distribution based on the volume is plotted from the small-diameter side with respect to the particle diameters measured, and the particle diameter at which 50% is accumulated is defined as the volume average particle diameter Dv. 50v .

[0274] In the present embodiment, the average circularity of the thermoplastic resin particles is not particularly limited, and in the case of toner, it is preferably 0.91 or more and 0.98 or less, more preferably 0.94 or more and 0.98 or less, and further preferably 0.95 or more and 0.97 or less from the viewpoint of maintaining the cleanliness of the image holding body.

[0275] In the present embodiment, the circularity of the thermoplastic resin particles refers to (the circumference of a circle having the same area as the projection image of the particle) ÷ (the circumference of the projection image of the particle), and the average circularity of the thermoplastic resin particles refers to the circularity at which 50% is accumulated from the small side in the distribution of the circularity. The average circularity of the thermoplastic resin particles is obtained by analyzing at least 3,000 thermoplastic resin particles using a flow-type particle image analysis device.

[0276] With respect to the average circularity of the thermoplastic resin particles, for example, in the case where the thermoplastic resin particles are produced by the coagulation aggregation method, it can be controlled by adjusting the stirring speed of the dispersion liquid, the temperature of the dispersion liquid, or the holding time in the fusion / merging step.

[0277] (External additive)

[0278] In the case where the thermoplastic resin particles are used as the toner for electrostatic image development described later, the thermoplastic resin particles can contain an external additive as needed.

[0279] In addition, the thermoplastic resin particles can be either thermoplastic resin particles having no external additive or particles in which an external additive is externally added to the thermoplastic resin particles.

[0280] As the external additive, for example, inorganic particles can be given. As the inorganic particles described above, Si02, Ti02, AI2O3, CuO, ZnO, Sn02, Ce02, Fe203, MgO, BaO, CaO, K20, Na20, Zr02, CaO-Si02, K20-(Ti02) n , AI2O3-2Si02, CaC03, MgC03, BaS04, MgS04, and the like can be given.

[0281] The surface of the inorganic particles as the external additive can be subjected to a hydrophobizing treatment. The hydrophobizing treatment is performed by, for example, immersing the inorganic particles in a hydrophobizing treatment agent or the like. The hydrophobizing treatment agent is not particularly limited, and for example, silane-based coupling agents, silicone oils, titanate-based coupling agents, aluminum-based coupling agents, and the like can be given. These can be used alone or in combination of two or more.

[0282] As the amount of the hydrophobizing treatment agent, for example, 1 part by mass or more and 10 parts by mass or less relative to 100 parts by mass of the inorganic particles is preferable.

[0283] As the external additive, resin particles (resin particles of polystyrene, polymethyl methacrylate (PMMA), melamine resin, and the like), a cleaning active agent (for example, a metal salt of a higher fatty acid represented by zinc stearate, a particle of a fluorine-based high molecular weight body), and the like can also be given.

[0284] As the external additive amount, for example, 0.01% by mass or more and 10% by mass or less, more preferably 0.01% by mass or more and 6% by mass or less, relative to the thermoplastic resin particles is preferable.

[0285] <Use of the thermoplastic resin particles>

[0286] The thermoplastic resin particles of the present embodiment are suitable for use as thermoplastic resin particles for image formation, and are more suitable for use as toner for electrostatic image development.

[0287] In addition, the thermoplastic resin particles of the present embodiment are also preferably used as a powder paint. The powder paint can also be used for the production of a painted product. After the powder paint is applied to a surface to be painted, heating (baking) is performed to cure the powder and form a painted film, thereby producing a painted product. At this time, the application and the heating (baking) can be performed integrally.

[0288] The powder can be applied by a known application method such as spray application, electrostatic powder application, triboelectric powder application, flow immersion, or the like. The thickness of the applied film of the powder is preferably, for example, 30 μm or more and 50 μm or less.

[0289] The heating temperature (baking temperature) is preferably, for example, 90°C or more and 250°C or less, more preferably 100°C or more and 220°C or less, and further preferably 120°C or more and 200°C or less. Note that the heating time (baking time) is adjusted by the heating temperature (baking temperature).

[0290] The object article to which the powder is applied is not particularly limited, and various metal members, ceramic members, resin members, and the like can be given. These object articles can be unformed articles before being formed into each article such as a plate-shaped article, a wire-shaped article, or the like, or formed articles for electronic components, road vehicles, interior and exterior decorative materials, or the like. In addition, the object article can be an article on which a surface treatment such as a primer treatment, a plating treatment, an electrodeposition coating, or the like has been performed in advance on the surface to be applied.

[0291] In addition, in fields other than application, the thermoplastic resin particles of the present embodiment are also suitable for use as resin particles for a toner display.

[0292] A toner display is known in which charged thermoplastic resin particles are dispersed in a medium (mostly air), and the resin particles are moved by an electric field to thereby display an image. The thermoplastic resin particles of the present embodiment can also be used without problems in such a toner display. For example, the resin particles are put in a cell sandwiched by two transparent electrodes, and a voltage is applied to move the thermoplastic resin particles, thereby displaying an image.

[0293] [Method for producing thermoplastic resin particles]

[0294] Next, a method for producing the thermoplastic resin particles of the present embodiment will be described.

[0295] The thermoplastic resin particles of the present embodiment are obtained by externally adding an external agent to the thermoplastic resin particles after the thermoplastic resin particles are produced.

[0296] The thermoplastic resin particles can be produced by any one of a dry production method (for example, a kneading and pulverization method, or the like), a wet production method (for example, a coagulation and aggregation method, a suspension polymerization method, a dissolution and suspension method, or the like). The production method is not particularly limited, and a known production method can be used. Among these, it is preferable that the thermoplastic resin particles are obtained by a coagulation and aggregation method.

[0297] As the coagulation and aggregation method, for example, the method described in Japanese Patent Application Laid-Open No. 2010-97101 or Japanese Patent Application Laid-Open No. 2006-154641 can be given.

[0298] As the kneading and pulverization method, for example, the method described in Japanese Patent Application Laid-Open No. 2000-267338 can be given.

[0299] As the dissolution and suspension method, the method described in Japanese Patent Application Laid-Open No. 2000-258950 can be given.

[0300] Further, specifically, for example, in the case of manufacturing the thermoplastic resin particles by the coagulation and aggregation method, the thermoplastic resin particles are manufactured by the following procedures: a procedure of preparing a resin particle dispersion liquid in which resin particles that become the binding resin are dispersed (resin particle dispersion liquid preparation procedure); a procedure of causing the resin particles (other particles as necessary) to coagulate in the resin particle dispersion liquid (in the dispersion liquid after mixing other particle dispersion liquids as necessary) to form coagulation particles (coagulation particle formation procedure); and a procedure of causing the coagulation particles dispersed in the coagulation particle dispersion liquid to fuse and aggregate to form the thermoplastic resin particles (fusion and aggregation procedure).

[0301] Hereinafter, each procedure will be described in detail.

[0302] In the following description, a method of obtaining the thermoplastic resin particles containing the colorant and the anti-adhesion agent is described, and the anti-adhesion agent is used as necessary. Of course, other additives other than the colorant and the anti-adhesion agent can be used.

[0303] - Resin Particle Dispersion Liquid Preparation Procedure -

[0304] A resin particle dispersion liquid in which resin particles that become the binding resin are dispersed is prepared, and for example, a colorant particle dispersion liquid in which colorant particles are dispersed, an anti-adhesion agent particle dispersion liquid in which anti-adhesion agent particles are dispersed are prepared.

[0305] Further, the method of manufacturing the thermoplastic resin particles of the present embodiment preferably uses the resin particle dispersion liquid containing the resin fine particles of the present embodiment as the above-described colorant particle dispersion liquid.

[0306] The resin particle dispersion liquid is prepared, for example, by dispersing the resin particles in a dispersion medium using a surfactant.

[0307] As the dispersion medium used in the resin particle dispersion liquid, for example, an aqueous medium can be given.

[0308] As the aqueous medium, for example, water such as distilled water, ion-exchange water, and the like, alcohols, and the like can be given. These can be used alone or in combination with two or more.

[0309] As the surfactant, for example, anionic surfactants such as sulfate ester salts, sulfonate salts, phosphate esters, soaps, and the like; cationic surfactants such as amine salts, quaternary ammonium salts, and the like; nonionic surfactants such as polyethylene glycol, alkylphenol ethylene oxide adducts, polyhydric alcohols, and the like; and the like can be given. Among these, anionic surfactants and cationic surfactants can be given in particular. The nonionic surfactant can be used in combination with the anionic surfactant or the cationic surfactant.

[0310] Among these, the use of a nonionic surfactant is preferred, and the use of a nonionic surfactant in combination with an anionic surfactant or a cationic surfactant is more preferred.

[0311] The surfactant can be used singly or in combination of two or more.

[0312] As a method of dispersing the resin particles in the dispersion medium, for example, a general dispersion method such as a rotational shearing type homogenizer, a ball mill with a medium, a sand mill, a bead mill, and the like can be given. In addition, depending on the kind of the resin particles, the resin particles can be dispersed in the dispersion medium by a phase inversion emulsification method. The phase inversion emulsification method refers to a method in which the resin to be dispersed is dissolved in a hydrophobic organic solvent in which the resin is soluble, and after neutralization by adding a base to the organic continuous phase (O phase), the water-based medium (W phase) is added, and thus phase inversion from W / O to O / W is performed, and the resin particles are dispersed in the water-based medium.

[0313] As the volume average particle diameter of the resin particles dispersed in the resin particle dispersion liquid, for example, 0.01 μm or more and 1 μm or less is preferred, 0.08 μm or more and 0.8 μm or less is more preferred, and 0.1 μm or more and 0.6 μm or less is further preferred.

[0314] As the volume average particle diameter of the resin particles, the particle size distribution obtained by a laser diffraction type particle size distribution measuring device (for example, manufactured by HORIBA, Ltd., LA-700) is used, and for the divided particle size range (section), the cumulative distribution is plotted against the volume from the small particle diameter side, and the particle diameter at which the cumulative amount is 50% with respect to the total particles is measured as the volume average particle diameter D50v. The volume average particle diameter of the particles in the other dispersion liquid is also measured in the same manner.

[0315] The content of the resin particles contained in the resin particle dispersion liquid is preferably 5% by mass or more and 50% by mass or less, and more preferably 10% by mass or more and 40% by mass or less.

[0316] The antisticking agent particle dispersion liquid is also prepared in the same manner as the resin particle dispersion liquid. That is, as the volume average particle diameter of the particles, the dispersion medium, the dispersion method, and the content of the particles in the resin particle dispersion liquid, the same applies to the antisticking agent particles dispersed in the antisticking agent particle dispersion liquid.

[0317] - Coagulated particle formation step -

[0318] Next, the resin particle dispersion liquid, the colorant particle dispersion liquid, and the anti-adhesion agent particle dispersion liquid are mixed.

[0319] Then, in the mixed dispersion liquid, the resin particles, the colorant particles, and the anti-adhesion agent particles are made to hetero-coagulate, and coagulated particles having a diameter close to the target diameter of the thermoplastic resin particles and containing the resin particles, the colorant particles, and the anti-adhesion agent particles are formed.

[0320] In addition, the method for manufacturing the thermoplastic resin particles of the present embodiment preferably uses, in the above coagulated particle formation step, a resin particle dispersion liquid containing the resin fine particles of the present embodiment as the above colorant particle dispersion liquid.

[0321] Specifically, for example, a coagulation agent is added to the mixed dispersion liquid, and the pH of the mixed dispersion liquid is adjusted to be acidic (for example, pH 2 or more and 5 or less), and, if necessary, a dispersion stabilizer is added, and then the mixed dispersion liquid is heated to a temperature close to the glass transition temperature of the resin particles (specifically, for example, a temperature of "the glass transition temperature of the resin particles - 30°C" or more and "the glass transition temperature of the resin particles - 10°C" or less), and the particles dispersed in the mixed dispersion liquid are made to coagulate, and coagulated particles are formed.

[0322] In the coagulated particle formation step, for example, the mixed dispersion liquid can be stirred with a rotational shear type homogenizer, a coagulation agent can be added at room temperature (for example, 25°C), the pH of the mixed dispersion liquid can be adjusted to be acidic (for example, pH 2 or more and 5 or less), and, if necessary, a dispersion stabilizer can be added, and then heating can be performed.

[0323] As the coagulation agent, for example, a surfactant having a polarity opposite to that of the surfactant contained in the mixed dispersion liquid, an inorganic metal salt, a metal complex of 2 or more valences can be given. In the case where a metal complex is used as the coagulation agent, the amount of the surfactant is reduced, and the charging characteristics are improved.

[0324] An additive that forms a complex or the like with the metal ion of the coagulation agent can be used together with the coagulation agent as necessary. As the additive, a chelating agent is suitably used.

[0325] As the inorganic metal salt, for example, metal salts such as calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, aluminum sulfate, and the like; inorganic metal salt polymers such as polyaluminum chloride, polyaluminum hydroxide, calcium polysulfide, and the like; and the like can be given.

[0326] As the chelating agent, a water-soluble chelating agent can be used. As the chelating agent, for example, hydroxycarboxylic acids such as tartaric acid, citric acid, gluconic acid; aminocarboxylic acids such as iminodiacetic acid (IDA), nitrilotriacetic acid (NTA), ethylenediaminetetraacetic acid (EDTA); and the like can be given.

[0327] The amount of the coagulant added is preferably 0.01 parts by mass or more and 5.0 parts by mass or less, more preferably 0.1 parts by mass or more and less than 3.0 parts by mass, relative to 100 parts by mass of the resin particles.

[0328] - Fusion and merging step -

[0329] Next, the coagulated particle dispersion liquid in which the coagulated particles are dispersed is heated to, for example, a temperature of 30°C to 50°C higher than the glass transition temperature of the resin particles or higher and a temperature higher than the melting temperature of the release agent, so that the coagulated particles are fused and merged, and thermoplastic resin particles are formed.

[0330] In the fusion and merging step, the resin and the release agent are in a state of being fused at a temperature higher than the glass transition temperature of the resin particles and higher than the melting temperature of the release agent. Then, cooling is performed, and thermoplastic resin particles are obtained.

[0331] As a method of adjusting the aspect ratio of the release agent in the thermoplastic resin particles, by keeping the temperature around the freezing point of the release agent for a certain period of time during cooling, so that the crystal grows, or by using two or more kinds of release agents having different melting temperatures, so that the crystal growth during cooling is promoted, it is possible to adjust the aspect ratio.

[0332] Through the above-described processes, thermoplastic resin particles are obtained.

[0333] After the coagulated particle dispersion liquid in which the coagulated particles are dispersed is obtained, the thermoplastic resin particles can be manufactured by the following processes: a process of further mixing the above-described coagulated particle dispersion liquid and a resin particle dispersion liquid in which resin particles are dispersed, and coagulating in a manner that resin particles further adhere to the surfaces of the coagulated particles, to form second coagulated particles; and a process of heating the second coagulated particle dispersion liquid in which the second coagulated particles are dispersed, so that the second coagulated particles are fused and merged, to form thermoplastic resin particles having a core-shell structure.

[0334] After the fusion and merging step is completed, the thermoplastic resin particles formed in the solution are subjected to a publicly known washing process, a solid-liquid separation process, and a drying process, and thermoplastic resin particles in a dried state are obtained. From the aspect of charging properties, the washing process is preferably performed so that displacement washing with ion exchange water is sufficiently performed. From the aspect of productivity, the solid-liquid separation process can be performed by suction filtration, pressure filtration, or the like. From the aspect of productivity, the drying process can be performed by freeze drying, airflow drying, fluidized drying, vibration-type fluidized drying, or the like.

[0335] After that, the thermoplastic resin particles of the present embodiment are manufactured, for example, by adding an external additive to the obtained thermoplastic resin particles in a dry state and mixing them. The mixing can be performed by, for example, a V-type stirrer, a Henschel mixer, a Loedige mixer, or the like. Further, a vibratory sifter, an air sifter, or the like can be used as needed to remove coarse particles of the thermoplastic resin particles.

[0336] <Electrostatic Image Developer>

[0337] In the case where the thermoplastic resin particles of the present embodiment are used as an electrostatic image developer, it can be a one-component developer containing only the thermoplastic resin particles of the present embodiment, or it can be a two-component developer in which the thermoplastic resin particles are mixed with a carrier.

[0338] As the carrier, there is no particular limitation, and known carriers can be given. As the carrier, for example, a coated carrier in which a resin is coated on the surface of a core material composed of a magnetic powder; a magnetic powder dispersion type carrier in which a magnetic powder is dispersed in a base resin; a resin-infiltrated type carrier in which a resin is infiltrated into a porous magnetic powder; and the like can be given. The magnetic powder dispersion type carrier and the resin-infiltrated type carrier can be a carrier in which a constituent particle of the carrier is used as a core material, and a resin is coated on the surface thereof.

[0339] As the magnetic powder, for example, a magnetic metal such as iron, nickel, cobalt, or the like; a magnetic oxide such as ferrite, magnetite, or the like; and the like can be given.

[0340] As the resin for coating and the base resin, for example, polyethylene, polypropylene, polystyrene, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl ether, polyvinyl ketone, a chlorovinyl-vinyl acetate copolymer, a styrene-acrylate copolymer, a pure silicone resin or a modified product thereof containing an organosiloxane bond, a fluororesin, a polyester, a polycarbonate, a phenol resin, an epoxy resin, and the like can be given. Additives such as electrically conductive particles can be contained in the resin for coating and the base resin. As the electrically conductive particles, for example, particles of a metal such as gold, silver, copper, or the like, carbon black, titanium dioxide, zinc oxide, tin oxide, barium sulfate, aluminum borate, potassium titanate, and the like can be given.

[0341] Among them, from the viewpoint of the suppression of density unevenness in the obtained image, a carrier having a surface coated with a resin containing a silicone resin is preferable, and a carrier having a surface coated with a silicone resin is more preferable.

[0342] As a method for coating the surface of the core material with the resin, the following methods can be mentioned: coating using a coating layer-forming solution prepared by dissolving the resin to be coated and various additives (used as necessary) in an appropriate solvent. The solvent is not particularly limited, and can be selected in consideration of the type of resin used, the coatability, and the like. As a specific resin coating method, the following methods can be mentioned: an immersion method in which the core material is immersed in the coating layer-forming solution; a spray method in which the coating layer-forming solution is sprayed onto the surface of the core material; a fluidized bed method in which the coating layer-forming solution is sprayed while the core material is floated by flowing air; a kneader coater method in which the core material and the coating layer-forming solution are mixed in a kneader coater and then the solvent is removed; and the like.

[0343] The mixing ratio (mass ratio) of the thermoplastic resin particles (toner for electrostatic image development) to the carrier in the two-component developer is preferably thermoplastic resin particles (toner for electrostatic image development) : carrier = 1 : 100 to 30 : 100, and more preferably 3 : 100 to 20 : 100.

[0344] <IMAGE FORMING APPARATUS, IMAGE FORMING METHOD>

[0345] An image forming apparatus / image forming method using the thermoplastic resin particles of the present embodiment as a toner for electrostatic image development will be described.

[0346] The image forming apparatus includes: an image holding body; a charging mechanism that charges the surface of the image holding body; an electrostatic image forming mechanism that forms an electrostatic image on the surface of the charged image holding body; a developing mechanism that accommodates an electrostatic image developer and develops the electrostatic image formed on the surface of the image holding body into a toner image using the electrostatic image developer; a transfer mechanism that transfers the toner image formed on the surface of the image holding body to the surface of a recording medium; and a fixing mechanism that fixes the toner image transferred to the surface of the recording medium. As the electrostatic image developer, an electrostatic image developer containing the thermoplastic resin particles of the present embodiment is used.

[0347] In the image forming apparatus, an image forming method having the following steps is implemented: a charging step of charging the surface of an image holding body; an electrostatic image forming step of forming an electrostatic image on the surface of the charged image holding body; a developing step of developing the electrostatic image formed on the surface of the image holding body into a toner image using an electrostatic image developer containing the thermoplastic resin particles of the present embodiment; a transfer step of transferring the toner image formed on the surface of the image holding body to the surface of a recording medium; and a fixing step of fixing the toner image transferred to the surface of the recording medium.

[0348] As the image forming apparatus, the following known image forming apparatuses are applied: a direct transfer type apparatus that directly transfers a toner image formed on a surface of an image holding body to a recording medium; an intermediate transfer type apparatus that once transfers a toner image formed on a surface of an image holding body to a surface of an intermediate transfer body, and secondarily transfers the toner image transferred to the surface of the intermediate transfer body to a surface of a recording medium; an apparatus provided with a cleaning mechanism that cleans the surface of the image holding body before charging after transferring the toner image; an apparatus provided with a charge removing mechanism that removes charge by irradiating the surface of the image holding body with a charge removing light after transferring the toner image and before charging; and the like.

[0349] In a case where the image forming apparatus is an intermediate transfer type apparatus, the configuration applied to the transfer mechanism has, for example, an intermediate transfer body on the surface of which a toner image is transferred; a primary transfer mechanism that once transfers a toner image formed on a surface of an image holding body to a surface of the intermediate transfer body; and a secondary transfer mechanism that secondarily transfers the toner image transferred to the surface of the intermediate transfer body to a surface of a recording medium.

[0350] In the image forming apparatus, for example, a part including the developing mechanism can be a cartridge structure (process cartridge) that is attached to and detached from the image forming apparatus. As the process cartridge, for example, a process cartridge provided with a developing mechanism that accommodates an electrostatic image developer containing the thermoplastic resin particles of the present embodiment is preferably used.

[0351] Hereinafter, an example of the image forming apparatus will be described, but is not limited thereto. In the following description, the main parts shown in the drawings will be described, and the description of other parts will be omitted.

[0352] Figure 1 is a schematic configuration view showing an image forming apparatus used in the present embodiment.

[0353] Figure 1 The image forming apparatus shown in the drawing is provided with first to fourth image forming units 10Y, 10M, 10C, 10K (image forming mechanisms) of an electrophotographic type, and these image forming mechanisms output yellow (Y), magenta (M), cyan (C), and black (K) images based on separated image data. These image forming units (hereinafter sometimes referred to as "units") 10Y, 10M, 10C, 10K are arranged at a distance apart from each other in the horizontal direction. These units 10Y, 10M, 10C, 10K can be process cartridges that are attached to and detached from the image forming apparatus.

[0354] Above the units 10Y, 10M, 10C, 10K, an intermediate transfer belt (one example of an intermediate transfer body) 20 is provided so as to extend across the units. The intermediate transfer belt 20 is wound around a driving roller 22 and a support roller 24 which are in contact with the inner face of the intermediate transfer belt 20, and is caused to travel in the direction from the first unit 10Y toward the fourth unit 10K. The support roller 24 applies a force in the direction away from the driving roller 22 by means of a spring or the like not shown, and applies tension to the intermediate transfer belt 20 wound around both of them. An intermediate transfer belt cleaning device 30 is provided on the image holding face side of the intermediate transfer belt 20, opposite the driving roller 22.

[0355] The developing devices (one example of a developing mechanism) 4Y, 4M, 4C, 4K of the units 10Y, 10M, 10C, 10K are respectively supplied with each color toner of yellow, magenta, cyan, and black which is housed in the toner cartridges 8Y, 8M, 8C, 8K.

[0356] The first to fourth units 10Y, 10M, 10C, 10K have the same configuration and operation, and therefore, here, the first unit 10Y which forms a yellow image, disposed on the upstream side in the direction of travel of the intermediate transfer belt, will be described as representative.

[0357] The first unit 10Y has a photoreceptor 1Y which functions as an image holding body. Around the photoreceptor 1Y, in order, are disposed: a charging roller (one example of a charging mechanism) 2Y which charges the surface of the photoreceptor 1Y to a predetermined potential; an exposure device (one example of an electrostatic image forming mechanism) 3 which forms an electrostatic image by exposure using a laser beam 3Y based on an image signal obtained by color separation of the charged surface; a developing device (one example of a developing mechanism) 4Y which supplies the electrostatic image with charged toner and develops the electrostatic image; a primary transfer roller (one example of a primary transfer mechanism) 5Y which transfers the developed toner image onto the intermediate transfer belt 20; and a photoreceptor cleaning device (one example of an image holding body cleaning mechanism) 6Y which removes toner remaining on the surface of the photoreceptor 1Y after primary transfer.

[0358] The primary transfer rollers 5Y, 5M, 5C, 5K of the respective units are connected to a bias power source (not shown) which applies a primary transfer bias. The bias power source is controlled by a control section (not shown) so as to change the value of the transfer bias applied to each primary transfer roller.

[0359] Next, the operation of forming a yellow image in the first unit 10Y will be described.

[0360] First, before the operation begins, the surface of the photoreceptor 1Y is charged to a potential of -600 V to -800 V by the charging roller 2Y.

[0361] The photoreceptor 1Y is formed by laminating a photosensitive layer on a base body having conductivity (volume resistivity of 1 x 10 -6 Ωcm or less). The photosensitive layer is generally high in resistance (resistance of a general resin), and has a property that, if a laser beam is irradiated, the resistivity of the portion irradiated with the laser beam changes. Therefore, the surface of the charged photoreceptor 1Y is irradiated with a laser beam 3Y in accordance with yellow image data transmitted from a control section (not shown) by an exposure device 3. Thereby, an electrostatic image of a yellow image pattern is formed on the surface of the photoreceptor 1Y.

[0362] The electrostatic image is so-called negative latent image, which is formed on the surface of the photoreceptor 1Y by charging, and is formed as follows: the resistivity of the irradiated portion of the photosensitive layer is reduced by the laser beam 3Y, the charged electric charges on the surface of the photoreceptor 1Y flow, on the other hand, the electric charges of the portion not irradiated with the laser beam 3Y remain, thereby forming the so-called negative latent image.

[0363] The electrostatic image formed on the photoreceptor 1Y rotates to a predetermined developing position as the photoreceptor 1Y operates. And, at the developing position, the electrostatic image on the photoreceptor 1Y is developed into a toner image by a developing device 4Y, thereby visualized.

[0364] Inside the developing device 4Y, an electrostatic image developer containing at least yellow toner and a carrier, for example, is accommodated. The yellow toner is agitated inside the developing device 4Y to be triboelectrically charged, has electric charges of the same polarity (negative polarity) as the charged electric charges on the photoreceptor 1Y, and is thereby held on a developer roller (an example of a developer holder). Thereafter, the surface of the photoreceptor 1Y passes through the developing device 4Y, whereby the yellow toner is electrostatically attached to the de-charged latent image portion on the surface of the photoreceptor 1Y, and the latent image is developed by the yellow toner. The photoreceptor 1Y on which the yellow toner image is formed continues to operate at a predetermined speed, and the toner image developed on the photoreceptor 1Y is transferred to a predetermined primary transfer position.

[0365] When the yellow toner image on the photoreceptor 1Y is transferred to the primary transfer position, a primary transfer bias is applied to a primary transfer roller 5Y, and the electrostatic force from the photoreceptor 1Y to the primary transfer roller 5Y acts on the toner image, so that the toner image on the photoreceptor 1Y is transferred to the intermediate transfer belt 20. At this time, the transfer bias applied is of a polarity (+) opposite to the polarity (-) of the toner, and is controlled to be +10 μA, for example, in the 1st unit 10Y by a control section (not shown). The toner remaining on the photoreceptor 1Y is removed and recovered in a photoreceptor cleaning device 6Y.

[0366] The transfer bias applied to the primary transfer rollers 5M, 5C, 5K after the second unit 10M is also controlled in the same manner as the first unit.

[0367] Thus, the intermediate transfer belt 20 on which the yellow toner image is transferred by the first unit 10Y is sequentially conveyed through the second to fourth units 10M, 10C, 10K, and the toner images of the respective colors are superimposed to perform multiple transfer.

[0368] The intermediate transfer belt 20 on which the multiple transfer of the toner images of the four colors is performed in the first to fourth units reaches a secondary transfer section. The secondary transfer section is composed of the intermediate transfer belt 20, a backup roller 24 which contacts the inner surface of the intermediate transfer belt, and a secondary transfer roller (an example of a secondary transfer mechanism) 26 which is disposed on the image holding surface side of the intermediate transfer belt 20. On the other hand, the recording paper (an example of a recording medium) P is fed to the nip where the secondary transfer roller 26 contacts the intermediate transfer belt 20 at a predetermined timing by a feeding mechanism, and a secondary transfer bias is applied to the backup roller 24. The transfer bias applied at this time is of the same polarity (-) as the polarity of the toner (-), and the electrostatic force from the intermediate transfer belt 20 to the recording paper P acts on the toner image, and the toner image on the intermediate transfer belt 20 is transferred to the recording paper P. The secondary transfer bias at this time is determined based on the resistance detected by a resistance detection mechanism (not shown) which detects the resistance of the secondary transfer section, and the voltage is controlled.

[0369] The recording paper P on which the toner image is transferred is sent to the nip of a pair of fixing rollers in a fixing device (an example of a fixing mechanism) 28, and the toner image is fixed to the recording paper P to form a fixed image. The recording paper P on which the color image is fixed is sent to a discharge section, and the series of color image forming operations is completed.

[0370] As the recording paper P on which the toner image is transferred, for example, a plain paper used in an electrophotographic copying machine, a printer, or the like can be given. As the recording medium, in addition to the recording paper P, an OHP film or the like can be given. In order to further improve the smoothness of the surface of the fixed image, it is preferable that the surface of the recording paper P is also smooth, and for example, a coated paper in which the surface of a plain paper is coated with a resin or the like, an art print paper for printing, or the like is suitably used.

[0371] <PROCESS CARTRIDGE, TONER CARTRIDGE>

[0372] In the case where the thermoplastic resin particles of the present embodiment are used as an electrostatic image developer, a process cartridge is a process cartridge which is attached to and detached from an image forming apparatus, and includes a developing mechanism which accommodates an electrostatic image developer containing the thermoplastic resin particles of the present embodiment, and develops an electrostatic image formed on the surface of an image holding body into a toner image by the electrostatic image developer.

[0373] The process cartridge can be configured with a developing mechanism and at least one mechanism selected from, for example, an image holding body, a charging mechanism, an electrostatic image forming mechanism, and a transfer mechanism, as needed.

[0374] An example of a process cartridge is shown below, but is not limited thereto. In the following description, the main parts shown in the drawings are described, and the other parts are omitted from the description.

[0375] Figure 2 A schematic configuration diagram showing an example of a process cartridge used in the present embodiment.

[0376] Figure 2 The process cartridge 200 shown is configured by holding the photosensitive body 107 (an example of an image holding body) in its entirety with a housing 117 provided with a mounting rail 116 and an opening 118 for exposure, together with a charging roller 108 (an example of a charging mechanism) provided around the photosensitive body 107, a developing device 111 (an example of a developing mechanism), and a photosensitive body cleaning device 113 (an example of a cleaning mechanism), and forms a cartridge.

[0377] Figure 2 In the drawing, 109 denotes an exposure device (an example of an electrostatic image forming mechanism), 112 denotes a transfer device (an example of a transfer mechanism), 115 denotes a fixing device (an example of a fixing mechanism), and 300 denotes a recording paper (an example of a recording medium).

[0378] Next, a toner cartridge is described.

[0379] The toner cartridge is a toner cartridge that accommodates the thermoplastic resin particles of the present embodiment as an electrostatic image developing toner and is attached to and detached from an image forming apparatus. The toner cartridge accommodates toner for replenishment to a developing mechanism provided in the image forming apparatus.

[0380] Figure 1 The image forming apparatus shown is an image forming apparatus configured with toner cartridges 8Y, 8M, 8C, and 8K attached to and detached from the image forming apparatus, and developing devices 4Y, 4M, 4C, and 4K are connected to the toner cartridges corresponding to each color by means of a not-shown toner supply tube. When the toner accommodated in the toner cartridge becomes low, the toner cartridge is replaced.

[0381] Example

[0382] Hereinafter, examples of the present application are described, but the present application is not limited to the following examples. Note that in the following description, "parts" and "%" are on a mass basis, unless otherwise specified.

[0383] Method for producing polyester resin A

[0384] • terephthalic acid: 30 mole parts

[0385] • fumaric acid: 70 mole parts

[0386] • bisphenol A ethylene oxide adduct: 5 mole parts

[0387] • bisphenol A propylene oxide adduct: 95 mole parts

[0388] In a flask equipped with a stirring device, a nitrogen gas introduction tube, a temperature sensor, and a rectifying column, the above-described materials were charged, and the temperature was raised to 220°C over 1 hour. With respect to 100 parts of the above-described materials, 1 part of titanium tetraethoxide was charged. While distilling off the generated water, the temperature was raised to 230°C over 30 minutes, and the dehydration condensation reaction was continued at 230°C for 1 hour. After that, the reaction product was cooled. In this way, a polyester resin A having an acid value of 12.0 mgKOH / g and a glass transition temperature of 60°C was obtained.

[0389] <Method for producing polyester resin B>

[0390] Terephthalic acid was made to be 27 mole parts, and the production was made by the same production method as the polyester resin A except for this. A polyester resin B having an acid value of 1.0 mgKOH / g and a glass transition temperature of 58°C was obtained.

[0391] <Method for producing polyester resin C>

[0392] Terephthalic acid was made to be 37.5 mole parts, and the production was made by the same production method as the polyester resin A except for this. A polyester resin C having an acid value of 50.0 mgKOH / g and a glass transition temperature of 62°C was obtained.

[0393] <Production of resin fine particle dispersion liquid (P1)>

[0394] - Melting step -

[0395] Polyester resin A (glass transition temperature (Tg): 60°C) 200 parts by mass, a 25% by mass sodium hydroxide aqueous solution 0.4 parts by mass, and basic fluorescent dye A (Basic Violet 11: 1, manufactured by Showa Denko K.K.) 2 parts by mass were charged into a raw material charging port of a twin-screw extruder (trade name: TEM26SS, manufactured by Toshiba Machine Co., Ltd.), and, in addition, a 48.5% by mass aqueous solution of sodium dodecyl diphenyl ether disulfonate (manufactured by Sanyo Chemical Industries, Ltd., ELEMINOL MON-7) as a surfactant was charged from the 4th cylinder of the twin-screw extruder 4.1 parts by mass, and melting was performed under conditions in which the cylinder temperature was 90°C and the screw rotation speed was 400 rpm (revolutions / minute) to produce an oily mixture.

[0396] - Emulsification step (phase inversion emulsification step) -

[0397] From the 5th barrel of the twin-screw extruder, 150 parts by mass of ion exchange water adjusted to 90°C (ion exchange water 1) was added, from the 7th barrel, 150 parts by mass of ion exchange water adjusted to 90°C (ion exchange water 2) was added, and from the 9th barrel, 150 parts by mass of ion exchange water adjusted to 90°C (ion exchange water 3) was added, and the oily mixture was emulsified to obtain a resin fine particle dispersion liquid (P1). At this time, the average supply amount F of the oily mixture was carried out at 12 kg / h.

[0398] The volume average particle size distribution of the particles in the obtained resin fine particle dispersion liquid was measured using a laser diffraction type particle size distribution measuring machine (LA-700, manufactured by HORIBA, Ltd.). As a result, the volume average particle diameter of the resin fine particles was 0.2 μm. The solid content was 31%.

[0399] <Manufacture of resin fine particle dispersion liquids (P2) to (P18), (P20), and (P21)>

[0400] The kind of the polyester resin, the amount of the base, the amount of the surfactant, and the pH at the emulsification step were changed as described in Table 1, and in addition, the following aspects were changed, and otherwise, the same as the resin fine particle dispersion liquid (P1), resin fine particle dispersion liquids (P2) to (P18), (P20), and (P21) were respectively manufactured.

[0401] (P6) As the basic dye, basic fluorescent dye B (Basic Red 1:1, manufactured by Showa Denko K.K., Rhodamine 6G CP-N) was used.

[0402] (P7) As the basic dye, basic fluorescent dye C (Basic Violet 10, manufactured by Showa Denko K.K., Rhodamine B) was used.

[0403] (P8) As the basic dye, basic fluorescent dye D (Basic Yellow 40, manufactured by Neelikon, Coumarin 40) was used.

[0404] (P9) As the basic dye, basic fluorescent dye E (Basic Red 13, manufactured by Tokyo Chemical Industry Co., Ltd.) was used.

[0405] (P10) As the basic dye, basic fluorescent dye F (Basic Blue 45, manufactured by Tokyo Chemical Industry Co., Ltd.) was used.

[0406] (P11) As the basic dye, basic dye G (Basic Yellow 2, manufactured by Tokyo Chemical Industry Co., Ltd.) was used.

[0407] <Manufacture of resin fine particle (P19): kneading pulverization method>

[0408] Polyester resin A 200 parts by mass, basic fluorescent dye A (basic violet 11: manufactured by Nitto Boseki Co., Ltd.) 2 parts by mass were charged into a raw material charging port of a twin-screw extruder (trade name: TEM26SS, manufactured by Toshiba Machine Co., Ltd.) to obtain a kneaded product. The obtained kneaded product was pulverized using a pulverizer (pulverizer AFG100, manufactured by Hosokawa Micron Co., Ltd.) to obtain resin fine particles (P19).

[0409] <Preparation of resin particle dispersion (1)>

[0410] • Terephthalic acid: 30 mole parts

[0411] • Fumaric acid: 70 mole parts

[0412] • Bisphenol A ethylene oxide adduct: 5 mole parts

[0413] • Bisphenol A propylene oxide adduct: 95 mole parts

[0414] In a flask equipped with a stirring device, a nitrogen gas introduction tube, a temperature sensor, and a rectifying column, the above-described materials were charged, and the temperature was raised to 220°C over 1 hour. With respect to 100 parts of the above-described materials, 1 part of titanium tetraethoxide was charged. While distilling off the generated water, the temperature was raised to 230°C over 30 minutes, and the dehydration condensation reaction was continued at 230°C for 1 hour. After that, the reaction product was cooled. In this way, a polyester resin having a weight average molecular weight of 18,000 and a glass transition temperature of 60°C was obtained.

[0415] In a container equipped with a temperature adjusting mechanism and a nitrogen gas replacement mechanism, ethyl acetate 40 parts and 2-butanol 25 parts were charged, and after a mixed solvent was prepared, a polyester resin 100 parts was slowly charged to be dissolved. To this, 10 mass% ammonia water solution (an amount equivalent to 3 times the amount in terms of molar ratio with respect to the acid value of the resin) was added, and stirred for 30 minutes. Next, the inside of the container was replaced with dry nitrogen gas, and the temperature was maintained at 40°C. While the mixed solution was stirred, ion exchange water 400 parts was added dropwise at a rate of 2 parts / minute. After the dropwise addition was completed, the temperature was returned to room temperature (20°C to 25°C), and while being stirred, bubbling was performed for 48 hours using dry nitrogen gas. In this way, a resin particle dispersion in which the amounts of ethyl acetate and 2-butanol were reduced to 1000 ppm or less was obtained. To the above-described resin particle dispersion, ion exchange water was added, and the solid content was adjusted to 20 mass% to obtain a resin particle dispersion (1).

[0416] <Preparation of anti-adhesive agent particle dispersion (1)>

[0417] • Paraffin wax (manufactured by Nippon Seiro Co., Ltd., HNP-9): 100 parts

[0418] • Anionic surfactant (manufactured by the First Industrial Co., Ltd., Neogen RK): 1 part

[0419] • Ion exchange water: 350 parts

[0420] The above materials were mixed and heated to 100°C, and after dispersion using a homogenizer (manufactured by IKA, trade name ULTRA-TURRAX T50), dispersion treatment was performed using a Menton Gorin high-pressure homogenizer (Gorin Co., Ltd.), to obtain a release agent particle dispersion liquid (1) in which release agent particles having a volume average particle diameter of 200 nm were dispersed (solid content 20 mass%).

[0421] (Example 1)

[0422] <Production of toner particles (1)>

[0423] • Resin fine particle dispersion liquid (P1): 3.7 parts

[0424] • Resin particle dispersion liquid (1): 80 parts

[0425] • Release agent particle dispersion liquid (1): 8.0 parts

[0426] • Anionic surfactant (manufactured by the First Industrial Co., Ltd., Neogen RK, 20%): 1.1 parts

[0427] The above materials were added to a round stainless steel flask, and after adjusting the pH to 3.5 by adding 0.1 N (= mol / L) nitric acid, 30 parts of a 10 mass% polyaluminum chloride aqueous nitric acid solution was added. Subsequently, after dispersion at a liquid temperature of 30°C using a homogenizer (manufactured by IKA, trade name ULTRA-TURRAX T50), heating was performed to 45°C in a heating oil bath for 30 minutes. Then, 20 parts of the resin particle dispersion liquid (1) was added, and after maintaining for 1 hour, the pH was adjusted to 8.5 by adding a 0.1 mol / L sodium hydroxide aqueous solution, and heating was performed to 84°C for 2.5 hours. Subsequently, cooling was performed to 20°C at a rate of 20°C / minute, the solid components were filtered, and sufficient washing was performed using ion exchange water, and drying was performed, to obtain toner particles (1). The volume average particle diameter of the toner particles (1) was 6 μm.

[0428] <Production of carrier 1>

[0429] • Ferrite particles (average particle diameter 35 μm): 100 parts

[0430] • Toluene: 14 parts

[0431] • Polymethyl methacrylate (MMA, weight average molecular weight 75,000): 5 parts

[0432] • Carbon black: 0.2 parts (VXC-72, manufactured by Cabot Corporation, volume resistivity: 100 Ωcm or less)

[0433] The above materials except for the ferrite particles were dispersed with a sand mill to prepare a dispersion liquid, and the dispersion liquid was put into a vacuum degassing type kneader together with the ferrite particles, and while stirring, depressurization and drying were performed, thereby obtaining carrier 1.

[0434] <Production of toner>

[0435] A sample mill was used to mix 1.5 parts by mass of hydrophobic silica (manufactured by Japan Aerosil Co., Ltd., RY50) and 1.0 parts by mass of hydrophobic titanium oxide (manufactured by Japan Aerosil Co., Ltd., T805) with respect to 100 parts by mass of the obtained toner particles (1) at 10,000 rpm (revolutions per minute) for 30 seconds. Then, sieving was performed using a vibrating sieve with a mesh size of 45 μm, thereby producing toner 1 (thermoplastic resin particles, toner for electrostatic image development). The volume average particle diameter of the obtained toner 1 was 6.0 μm.

[0436] <Production of electrostatic image developer>

[0437] A V-type stirrer was used to mix 8 parts of toner and 92 parts of carrier, thereby producing developer 1 (electrostatic image developer).

[0438] (Examples 2 to 14 and Comparative Examples 1 to 7)

[0439] The resin fine particle dispersion liquid (P1) was changed to the resin fine particle dispersion liquids (P2) to (P21) described in Table 1, and otherwise, thermoplastic resin particles (toner for electrostatic image development) of Examples 2 to 14 or Comparative Examples 1 to 7 were produced by the same method as in Example 1.

[0440] The obtained thermoplastic resin particles (toner for electrostatic image development) and electrostatic image developers of Examples 1 to 14 and Comparative Examples 1 to 7 were used to perform the following evaluations. The evaluation results are summarized in Table 1.

[0441] <Measurement of concentration difference of basic dye between surface layer part of resin fine particle and center of gravity part of resin fine particle>

[0442] The resin fine particles were embedded in a resin and cut with a microtome to obtain a cross section.

[0443] For its cross section, whether or not there is an element derived from the dye (Zn or the like, which differs depending on the basic dye contained) is analyzed (specifically, mapped) using scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX) analysis.

[0444] The concentration of the element derived from the dye is found for the surface layer (less than 10 nm from the profile in the cross-sectional view of the resin fine particle) and the center of gravity of the cross section of the resin fine particle, respectively. Specifically, for one particle, the average concentration of the element derived from the dye in each of the surface layer 5 and the center of gravity 5 nm square is calculated, and the above calculation is performed for 50 particles. For each particle, the concentration ratio of the average of the concentration at the surface layer 5 to the concentration at the center of gravity is found, and the average of the concentration ratios of the 50 resin fine particles is calculated, which is taken as the value of the concentration ratio of the above basic dye. In finding the concentration of the element derived from the dye, the presence or absence of the element derived from the dye is binarized and contrast is imparted by SEM-EDX analysis.

[0445] <Average distance X between adjacent basic dye-containing regions in the cross section of the thermoplastic resin particle D >

[0446] A sample is prepared by embedding the thermoplastic resin particles in a resin. A section is prepared from the prepared sample using a microtome. The position of the dye is determined from the cross-sectional observation of the obtained section. As the analysis method for determining the position of the basic dye-containing region, energy dispersive X-ray analysis (EDX) is used. In addition, the distance between the basic dye-containing regions is measured as the distance from the center of gravity of each basic dye-containing region. With respect to the average distance X D between the above regions, the average value of the distance between the basic dye-containing regions contained in one thermoplastic resin particle is measured, and the above operations are performed for cross-sectional observation of 50 or more thermoplastic resin particles, and the average is adopted.

[0447] <Development density evaluation 1>

[0448] The following operations and image formation are performed in an environment of a temperature of 23°C and a humidity of 50% RH. As an image forming apparatus for forming an evaluation image, an Apeos Port IV C4470 manufactured by Fuji Xerox Co., Ltd. is prepared, a developer is loaded into a developer, and the prepared thermoplastic resin particles (toner for electrostatic image development) as a supplemental toner are loaded into a toner cartridge. Subsequently, an OS copper plate paper (basis weight 127 g / m 2 ) manufactured by Fuji Xerox Co., Ltd. is formed with an image area ratio of 100% of 5 cm x 5 cm, and the toner amount is adjusted to 4.5 g / m 2The image was output at a fixing temperature of 170°C and the color density was evaluated. The color density was measured using X-Rite (manufactured by X-Rite). * , L * The value of 65 or above is set to A, and L * The value of 60 or more and less than 65 is set to B, and L * A value of less than 60 was set as C. In addition, the above A to C are the following evaluations.

[0449] A: There is no practical problem.

[0450] B: The color rendering is slightly poor, but there is no problem in practical use.

[0451] C: Clearly discernible even by visual inspection, but problematic in practical use.

[0452] <Fluorescence Intensity Evaluation (Color Concentration Evaluation 2)>

[0453] The following operations and image formation were performed under an environment of temperature 23° C. / humidity 50% RH.

[0454] As an image forming apparatus for forming an evaluation image, an ApeosPortIV C4470 manufactured by Fuji Xerox Co., Ltd. was prepared. A developer was loaded into the developing device, and the prepared thermoplastic resin particles (toner for electrostatic image development) as a replenishing toner were loaded into the toner cartridge. Next, OS coated paper (basis weight 127 g / m2) manufactured by Fuji Xerox Co., Ltd. was printed on the surface of the printed paper. 2 ) An image of 5 cm×5 cm with an image area ratio of 100% was formed, output at a fixing temperature of 170° C., and fluorescence intensity evaluation was performed.

[0455] Regarding the fluorescence intensity, the spectral reflectance in the visible light region was measured using X-Rite (manufactured by X-Rite Corporation), and the fluorescence peak intensity at the spectral reflectance was defined as the fluorescence intensity.

[0456] A: More than 108%

[0457] B: 104% or more and less than 108%

[0458] C: 100% or more and less than 104%

[0459] D: less than 100%

[0460]

[0461]

[0462] Note that the "concentration ratio of basic dye" in Table 1 indicates the ratio of the concentration of the basic dye in the center-of-gravity portion of the resin fine particles to the concentration of the basic dye in the surface layer portion of the resin fine particles to a depth of 10 nm or less from the surface.

[0463] In addition, in Comparative Example 1, the thermoplastic resin particles could not be produced, and evaluation could not be performed.

[0464] As is apparent from the results shown in Table 1 above, the thermoplastic resin particles (toner for electrostatic image development) of the present example produced an image having a higher color development density than the thermoplastic resin particles (toner for electrostatic image development) of the comparative example.

[0465] In addition, as is apparent from the results shown in Table 1 above, the thermoplastic resin particles (toner for electrostatic image development) of the present example produced an image having a higher fluorescence intensity.

[0466] (Example 15)

[0467] -Production of Coated Product-

[0468] On a 10 cm x 10 cm quadrilateral test panel of a zinc phosphate-treated steel sheet, the thermoplastic resin particles of Example 1 were applied using a corona gun manufactured by Asahi Sunac Corporation, by sliding the corona gun up and down and left and right from a distance of 30 cm from the front surface, at a coating film thickness of 30 μm or more and 50 μm or less, and then baking was performed at 150°C for 5 minutes, to produce a coated product.

[0469] With the coated product produced, it was confirmed that powder adhered to the coated product (zinc phosphate-treated steel sheet), and coating was completed.

Claims

1. A resin fine particle which is a resin fine particle containing a polyester resin and a basic dye, wherein the volume average particle diameter of the resin fine particle is 0.05 μm or more and 1 μm or less, the ratio of the concentration of the basic dye in the center-of-gravity portion of the resin fine particle to the concentration of the basic dye in the surface layer portion of the resin fine particle to a depth of 10 nm or less from the surface is 0.8 or more, the concentrations of the basic dye in the center-of-gravity portion and the surface layer portion are the average concentrations of elements derived from the basic dye in each of 5 nm squares at the center of gravity and the surface layer 5, respectively, obtained by scanning electron microscope-energy dispersive X-ray spectroscopy (SEM-EDX), the content of the basic dye in the resin fine particle is 0.1 parts by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the polyester resin of the resin fine particle, and the acid value of the polyester resin is 1 mgKOH / g or more and 50 mgKOH / g or less. The volume average particle diameter of the resin fine particle is 0.05 μm or more and 0.5 μm or less. The content of the basic dye in the resin fine particle is 0.5 parts by mass or more and 10 parts by mass or less with respect to 100 parts by mass of the polyester resin of the resin fine particle. The basic dye contains a basic fluorescent dye. The acid value of the polyester resin is 5 mgKOH / g or more and 18 mgKOH / g or less.

2. The resin fine particles according to claim 1, wherein 6. A thermoplastic resin particle which contains a binding resin and the resin fine particle according to claim 1.

3. The resin fine particles according to claim 1, wherein 10. The thermoplastic resin particle according to claim 6, which is produced by at least coagulating the resin fine particle.

4. The resin fine particles according to claim 1, wherein 11. A method for producing a resin fine particle, which is a method for producing the resin fine particle according to claim 1, comprising: a dissolving or melting step of bringing at least an oily mixture of a polyester resin, a base, and a basic dye into a dissolved state or a molten state while imparting a shear force thereto; and an emulsifying step of adding a surfactant and an aqueous medium to the dissolved or molten oily mixture while imparting a shear force thereto to emulsify and obtain a dispersion liquid of the resin fine particle.

5. The resin fine particles as claimed in claim 1, wherein, The pH of the dispersion liquid is 7 or more and 11 or less.

11. The method for producing a resin fine particle according to claim 11, wherein the pH of the dispersion liquid is 7 or more and 11 or less.

7. The thermoplastic resin particles according to claim 6, wherein In the cross section of the thermoplastic resin particles, the average distance X between adjacent regions containing the basic dye D satisfies the following formula L: 0.01 x D 50v ≤ X D ≤ 0.4 x D 50v Formula L Note that D 50v represents the volume average particle diameter of the thermoplastic resin particles.

8. The thermoplastic resin particles according to claim 7, wherein, The average distance X D is 0.05 μm or more and 3.0 μm or less.

9. The thermoplastic resin particles according to claim 8, wherein, The average distance X D is 0.08 μm or more and 2.5 μm or less. ​ ​ ​ ​ ​ 12. The method for producing resin fine particles according to claim 11, wherein ​

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