Two-component developer

Abstract

To provide a two-component developer that can have superior image stability, suppress unevenness in image density, and stably form an image with high in-plane uniformity.SOLUTION: There is provided a two-component developer which includes toner and a magnetic carrier, wherein the magnetic carrier has a magnetic carrier core and a coating resin layer with a specific structure which covers the surface of the magnetic carrier core, and the toner has composite particles on its toner particle surface. A composite particle is a particulate having a particulate A including an organic silicon compound with a specific structure having a siloxane bond as a binder component, and also has a particulate B present on its surface while embedded in part in the surface of the particulate A, wherein an average value of the embedding rate of the particulate B is 30 to 90%, and the composite particle has a number average particle size of 0.03 to 0.30 μm of primary particles.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present disclosure relates to a two-component developer used in an image forming method for visualizing an electrostatic image using an electrophotographic method. [Background technology]

[0002] Conventionally, electrophotographic image forming methods generally involve forming an electrostatic latent image on an electrostatic latent image carrier using various means, and then developing the electrostatic latent image by attaching toner to the electrostatic latent image. In this development, a two-component development method is widely used in which carrier particles called magnetic carriers are mixed with the toner, and the toner is frictionally charged to impart an appropriate amount of positive or negative charge to the toner, and the charge is used as a driving force for development. The two-component development method has the advantage that the magnetic carrier can be given functions such as stirring, transporting, and charging the developer, so the division of functions between the magnetic carrier and the toner is clear, and therefore developer performance can be easily controlled. On the other hand, in recent years, with the advancement of technology in the field of electrophotography, there has been an increasingly strict demand for not only higher speed and longer life of the device, but also higher definition and stable image quality. In order to meet these demands, there is a demand for higher performance of two-component developers. To achieve such a two-component developer, a toner has been proposed that exhibits excellent image stability by suppressing image defects such as white spots even after long-term use, and also exhibits excellent fixing properties (see Patent Document 1). This toner is characterized by having organic-inorganic composite particles with multiple convex portions on the toner surface. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-139063 Summary of the Invention [Problem to be solved by the invention]

[0004] The toner of Patent Document 1 improved issues such as image stability and fixability over long-term use. However, because it is difficult to completely prevent the migration of such composite particles from the toner particle surface, some composite particles may migrate to the magnetic carrier surface over long periods of use. Furthermore, such composite particles tend to concentrate triboelectric charge on the protruding portions of the surface. Therefore, as a result of composite particles with concentrated charge on the protruding portions migrating to the magnetic carrier surface, variations in the charge imparting ability of the magnetic carrier surface occur, resulting in a broad charge distribution of the two-component developer. This can lead to uneven image density within printed images over long periods of use and reduced in-plane uniformity. This problem is also likely to occur when printing on a high image ratio or large paper size. In the market, particularly in the field of on-demand printers, there is an ever-increasing demand for suppressing unevenness in image density within printed images even after long-term use, and consistently obtaining images with high in-plane uniformity. Therefore, there is an urgent need to develop a two-component developer that exhibits excellent image stability by suppressing image defects such as white spots even after long-term use, and further suppresses unevenness in image density within printed images, thereby consistently obtaining images with high in-plane uniformity. An object of the present disclosure is to provide a two-component developer that solves these problems. Specifically, the present invention provides a two-component developer that exhibits excellent image stability by suppressing image defects such as white spots even when used for a long period of time, and further suppresses unevenness in image density within a printed image, thereby always producing images with high in-plane uniformity. [Means for solving the problem]

[0005] The inventors have found that by using a two-component developer as shown below, - Even after long-term use, image defects such as white spots can be suppressed, resulting in excellent image stability - Image density variations are suppressed, resulting in stable, highly uniform images across the screen. We found that... That is, the present disclosure provides a two-component developer including a toner and a magnetic carrier, The magnetic carrier has a magnetic carrier core and a coating resin layer that coats the surface of the magnetic carrier core, and the coating resin layer has at least one structure selected from the structures represented by the following formula (A), (B), or (C):

[0006] [ka] (wherein X represents a carbon atom or a silicon atom. R a , R b each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. The toner has composite particles on the surface of the toner particles, The composite particles are (i) fine particles A containing an organosilicon compound having a siloxane bond as a binder component; (ii) a particle B present in a state of being partially embedded on the surface of the particle A; and The composite particles have a number average particle size of primary particles of 0.03 μm or more and 0.30 μm or less, The solid of the fine particles A 29 In the Si-NMR DD-MAS measurement, when the proportion of silicon atoms present in the state of the following unit (a) relative to all silicon atoms is Xa (%), the proportion of silicon atoms present in the state of the following unit (b) is Xb (%), and the proportion of silicon atoms present in the state of the following unit (c) is Xc (%), the contents of Xa, Xb, and Xc satisfy the following formulas (1) and (2): Xa + Xb + Xc ≥ 80% (1) Xb+Xc≧30% (2)

[0007] [ka] (In the formula, R1 and R2 each independently represent an alkyl group having 1 to 6 carbon atoms.) In the composite particles, the average embedding rate of the fine particles B, as expressed by the following formula, is 30% or more and 90% or less, Burial rate of particle B (%) = (depth of particle B buried in particle A / diameter of particle B) x 100 The solid of the composite particle 29 In the Si-NMR DD-MAS measurement, Si in the structure represented by the following formula (3) a and the peak PD1 corresponding to the silicon atom represented by the following formula (4). b and a peak PT1 corresponding to a silicon atom represented by the following formula (5): c and the peak PT2 corresponding to the silicon atom represented by the following formula (6): d and a peak PQ1 corresponding to a silicon atom represented by the following formula (7): e and the peak PQ2 corresponding to the silicon atom represented by the following formula (8): f A peak PQ3 corresponding to a silicon atom represented by The present invention relates to a two-component developer that satisfies the following formula (9), where SD1 is the area of ​​peak PD1, ST1 is the area of ​​peak PT1, ST2 is the area of ​​peak PT2, SQ1 is the area of ​​peak PQ1, SQ2 is the area of ​​peak PQ2, SQ3 is the area of ​​peak PQ3, and SSi is the area of ​​the total peak i due to all silicon atoms.

[0008] [ka] (In the formula, R3 and R4 each independently represent an alkyl group having 1 to 6 carbon atoms.)

[0009]

number

[0010] The present disclosure provides excellent image stability by suppressing image defects such as white spots even during long-term use, and further suppresses uneven image density within printed images, thereby consistently producing images with high in-plane uniformity. DETAILED DESCRIPTION OF THE INVENTION

[0011] In the present disclosure, the expressions "xx or more and xx or less" and "xx to xx" representing a numerical range mean a numerical range including the lower and upper limits, which are the endpoints, unless otherwise specified. In the present disclosure, a (meth)acrylic acid ester means an acrylic acid ester and / or a methacrylic acid ester.

[0012] [The process and significance of the present disclosure] The magnetic carrier in the two-component developer of the present disclosure has a magnetic carrier core and a coating resin layer that coats the surface of the magnetic carrier core, and the coating resin layer has at least one structure selected from the structures represented by the following formula (A), (B), or (C):

[0013] [ka] (wherein X represents a carbon atom or a silicon atom. R a , R b each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0014] The toner in the present disclosure is a toner having composite particles on the surface of the toner particles. The composite particles are (i) fine particles A containing an organosilicon compound having a siloxane bond as a binder component; (ii) a particle B present in a state of being partially embedded on the surface of the particle A; It has. The composite particles have a number average particle size of primary particles of 0.03 μm or more and 0.30 μm or less. Solid of fine particles A 29In the DD-MAS measurement of Si-NMR, when the proportion of silicon atoms present in the state of the following unit (a) relative to all silicon atoms is Xa (%), the proportion of silicon atoms present in the state of the following unit (b) is Xb (%), and the proportion of silicon atoms present in the state of the following unit (c) is Xc (%), Xa, Xb, and Xc satisfy the following formulas (1) and (2): Xa + Xb + Xc ≥ 80% (1) Xb+Xc≧30% (2)

[0015] [ka] (In the formula, R1 and R2 each independently represent an alkyl group having 1 to 6 carbon atoms.)

[0016] In the composite particles, the fine particles B have an average embedding rate, represented by the following formula, of 30% or more and 90% or less. Burial rate of particle B (%) = (depth of particle B buried in particle A / diameter of particle B) x 100

[0017] Furthermore, the solid of the composite particles 29 In the Si-NMR DD-MAS measurement, Si in the structure represented by the following formula (3) a and the peak PD1 corresponding to the silicon atom represented by the following formula (4). b and a peak PT1 corresponding to a silicon atom represented by the following formula (5): c and the peak PT2 corresponding to the silicon atom represented by the following formula (6): d and a peak PQ1 corresponding to a silicon atom represented by the following formula (7): e and the peak PQ2 corresponding to the silicon atom represented by the following formula (8): f A peak PQ3 corresponding to a silicon atom represented by When the area of ​​peak PD1 is SD1, the area of ​​peak PT1 is ST1, the area of ​​peak PT2 is ST2, the area of ​​peak PQ1 is SQ1, the area of ​​peak PQ2 is SQ2, the area of ​​peak PQ3 is SQ3, and the total peak area of ​​all silicon atoms is SSi, the following formula (9) is satisfied. 1 / 2 " indicates that the oxygen atom in question is bonded to two silicon atoms (one silicon atom is not shown).

[0018] [ka] (In the formula, R3 and R4 each independently represent an alkyl group having 1 to 6 carbon atoms.)

[0019]

number

[0020] The mechanism by which the two-component developer of the present disclosure can solve the problems is thought to be as follows.

[0021] The toner constituting the two-component developer of the present disclosure has composite particles on the surface of the toner particles. These composite particles have fine particles B present on the surface of fine particles A in a partially embedded state. Furthermore, the fine particles A constituting these composite particles have the specific structures shown in (a) to (c) above in the above ratios. Furthermore, the composite particles satisfy the relationship shown in formula (9) above.

[0022] On the other hand, the magnetic carrier constituting the two-component developer of the present disclosure has a coating resin layer on the surface of the magnetic carrier core, and further, this coating resin layer has a specific structure with polarity.

[0023] In general, the use of composite particles with protrusions on the surface prevents migration from the toner particle surface to the magnetic carrier surface or other components, even during long-term use. Suppressing migration can prevent toner degradation in two-component developers, thereby suppressing image defects such as white spots and achieving excellent image stability. However, over long-term use, some composite particles migrate to the magnetic carrier surface. Migration of composite particles with uneven surface charge to the magnetic carrier surface can cause variations in the charge-imparting ability of the magnetic carrier over long-term use. Variations in the charge-imparting ability of the magnetic carrier result in a broad charge distribution in the two-component developer, resulting in uneven image density and reduced in-plane uniformity.

[0024] In the configuration of the present disclosure, as described above, the fine particles A constituting the composite particles present on the toner particle surface and the coating resin layer present on the magnetic carrier core surface each have a specific structure. Because these structures each have polarity, even when composite particles with charge concentrated on the convex portions migrate to the magnetic carrier surface, an interaction occurs between the polar portions of the fine particles A and the polar portions of the coating resin layer, and the charge concentrated on the convex portions is thought to diffuse to the coating resin layer via these polar groups. As a result, we believe that the variation in the charge imparting ability of the magnetic carrier surface is suppressed, the broadening of the charge distribution of the two-component developer is suppressed, and uneven image density within printed images over long-term use is suppressed, resulting in stable, highly uniform images.

[0025] [Main configuration of the present disclosure] From the viewpoint of suppressing white spots and improving in-plane uniformity, it is important that the above formula (9) is 0.10 or more and 0.30 or less for the two-component developer of the present disclosure. When the above formula (9) is within the above range, the interaction between the polar moieties of the composite particles migrated to the magnetic carrier surface and the coating resin layer on the magnetic carrier core surface becomes moderate, and the charge concentrated on the convex portions of the composite particles diffuses to the coating resin layer, improving in-plane uniformity. Furthermore, variation in the charge imparting ability of the carrier surface can be suppressed, and good in-plane uniformity can be maintained. From the viewpoint of further suppressing white spots and improving in-plane uniformity, it is more preferable to satisfy the following formula (10).

[0026]

number

[0027] From the viewpoint of suppressing white spots and improving in-plane uniformity, it is important that particle B is present in a state where it is partially embedded in the surface of particle A, and that the average embedding rate is 30% or more and 90% or less.

[0028] From the viewpoint of suppressing white spots and improving in-plane uniformity, it is important that the number-average particle size of the primary particles of the composite particles is 0.03 μm or more and 0.30 μm or less. When the number-average particle size of the primary particles of the composite particles is within this range, stress on the toner is suppressed, and therefore the composite particles can be prevented from being buried in the toner surface. In addition, the composite particles can be prevented from migrating to the magnetic carrier surface, resulting in good in-plane uniformity.

[0029] From the viewpoint of suppressing white spots and improving in-plane uniformity, the solid of fine particles A 29 In DD-MAS measurement of Si-NMR, when the ratio of silicon atoms present in the state of the following unit (a) to all silicon atoms is Xa (%), the ratio of silicon atoms present in the state of the following unit (b) is Xb (%), and the ratio of silicon atoms present in the state of the following unit (c) is Xc (%), it is important that Xa, Xb, and Xc satisfy the following formulas (1) and (2): Xa + Xb + Xc ≥ 80% (1) Xb+Xc≧30% (2)

[0030] [ka] (In the formula, R1 and R2 each independently represent an alkyl group having 1 to 6 carbon atoms.)

[0031] Within the above range, the fine particles A can have an appropriate polarity portion, so that unevenness in image density within a printed image is suppressed over long-term use, and images with high in-plane uniformity are always obtained.

[0032] From the viewpoint of suppressing white spots and improving in-plane uniformity, it is important that the coating resin layer present on the surface of the magnetic carrier core has at least one structure selected from the group consisting of a structure represented by the following formula (A), a structure represented by the following formula (B), and a structure represented by the following formula (C). Cases in which a plurality of these structures are present are also included in the present disclosure.

[0033] [ka] (wherein X represents a carbon atom or a silicon atom. R a , R b each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0034] If the above structure is not present, the interaction between the polar portions of the composite particles transferred to the magnetic carrier surface and the coating resin layer on the magnetic carrier core surface will be weakened, making it difficult for the charges concentrated on the convex portions of the composite particles to diffuse to the coating resin layer, and in-plane uniformity will tend to decrease.From the viewpoint of further suppressing white spots and improving in-plane uniformity, it is more preferable for the structure represented by the above formula (A) to be present.

[0035] The configuration of the present disclosure will be described in detail below, including preferred embodiments.

[0036] [Composite particles] The composite particles have (i) fine particles A containing an organosilicon compound having a siloxane bond as a binder component, and (ii) fine particles B present on the surface of the fine particles A in a partially embedded state.

[0037] The number average particle size of the primary particles of the composite particles is more preferably 0.06 μm or more and 0.30 μm or less, from the viewpoint of suppressing white spots and improving in-plane uniformity.

[0038] The number average particle size of the primary particles of the composite particles can be increased by lowering the reaction temperature, shortening the reaction time, or increasing the amount of catalyst in the hydrolysis and condensation steps, while the number average particle size of the primary particles of the external additive can be decreased by increasing the reaction temperature, lengthening the reaction time, or decreasing the amount of catalyst in the hydrolysis and condensation steps.

[0039] From the viewpoint of suppressing white spots and improving in-plane uniformity, the unit ratio "Xb+Xc" of the fine particles A contained in the composite particles is preferably 55% or more.

[0040] In addition, from the viewpoint of suppressing white spots and improving in-plane uniformity, it is preferable that the content ratios of the above units (a), (b) and (c) satisfy the following formulas (12), (13) and (14). 30%≦Xa / (Xa+Xb+Xc)≦80% (12) 0%≦Xb / (Xa+Xb+Xc)≦50% (13) 20%≦Xc / (Xa+Xb+Xc)≦70% (14)

[0041] The content ratio of the above units (a), (b) and (c) in the composite particles can be controlled by the amount of alkoxysilane having each structure added.

[0042] It is important that the particle B is present in a state where at least a portion thereof is embedded in the surface of the particle A, and that the average embedding rate is 30% to 90%. The embedding rate of the particle B can be controlled by the reaction time and reaction temperature with the alkoxysilane having the structures (a) to (c) above. To reduce the embedding rate, methods include shortening the reaction time between the alkoxysilane and the particle B and lowering the reaction temperature. To increase the embedding rate, methods include lengthening the reaction time between the alkoxysilane and the particle B and raising the reaction temperature.

[0043] When microparticles containing an organosilicon compound having a simple siloxane bond as a binder without the protrusions derived from microparticle B are used as an external additive in a toner, the effect of suppressing toner deterioration in a two-component developer described above cannot be obtained, and image defects such as white spots cannot be suppressed.Furthermore, when microparticle B is completely embedded inside microparticle A, image defects such as white spots cannot be suppressed for the same reason.

[0044] The methods for measuring various physical properties will be described later.

[0045] <Manufacturing method> Although the method for producing composite particles is not particularly limited, it is preferable to form particles through hydrolysis and condensation polymerization of a silicon compound (silane monomer) by the sol-gel method. Specifically, it is preferable to hydrolyze and condense a mixture of a bifunctional silane having two siloxane bonds and a tetrafunctional silane having four siloxane bonds, and then react the mixture with colloidal silica or the like to form composite fine particles. Silane monomers such as bifunctional silanes and tetrafunctional silanes will be described later. The proportion of bifunctional silane is preferably 20 mol% to 70 mol%, more preferably 30 mol% to 60 mol%. The proportion of trifunctional silane is preferably 0 mol% to 50 mol%, more preferably 0 mol% to 40 mol%. The proportion of tetrafunctional silane is preferably 30 mol% to 80 mol%, more preferably 40 mol% to 70 mol%.

[0046] The method for producing the organosilicon compound that constitutes the fine particles A is not particularly limited. For example, a silane compound can be added dropwise to water, hydrolyzed and condensed in the presence of a catalyst, and the resulting suspension can be filtered and dried. The particle size can be controlled by the type of catalyst, the compounding ratio, the reaction initiation temperature, the dropwise addition time, etc. Examples of acidic catalysts include hydrochloric acid, hydrofluoric acid, sulfuric acid, and nitric acid, and examples of basic catalysts include, but are not limited to, aqueous ammonia, sodium hydroxide, and potassium hydroxide.

[0047] The silicon compound is preferably produced by the following method. Specifically, it preferably includes a first step of obtaining a hydrolysate of a silicon compound, a second step of mixing the hydrolysate with an alkaline aqueous medium and colloidal silica to polycondense the hydrolysate and react it with the colloidal silica, and a third step of mixing the polycondensation reaction product with an aqueous solution to form particles. In some cases, a hydrophobizing agent may also be added.

[0048] In the first step, a silicon compound is contacted with a catalyst by stirring, mixing, or the like in an aqueous solution in which an acidic or alkaline substance serving as a catalyst is dissolved in water. Known catalysts can be suitably used. Specific examples of acidic catalysts include acetic acid, hydrochloric acid, hydrofluoric acid, sulfuric acid, and nitric acid, while basic catalysts include aqueous ammonia, sodium hydroxide, and potassium hydroxide.

[0049] The amount of catalyst used may be adjusted appropriately depending on the type of silicon compound and catalyst. Preferably, the amount of catalyst used is 1×10 -3 The amount is selected from the range of 1 part by mass or more and 1 part by mass or less.

[0050] The amount of catalyst used is 1×10 -3If the amount of catalyst used is 1 part by mass or more, the reaction proceeds sufficiently. On the other hand, if the amount of catalyst used is 1 part by mass or less, the concentration of impurities remaining in the fine particles will be low, making hydrolysis easier. The amount of water used is preferably 2 to 15 moles per mole of silicon compound. If the amount of water is 2 moles or more, the hydrolysis reaction will proceed sufficiently, and if it is 15 moles or less, productivity will be improved.

[0051] The reaction temperature is not particularly limited and may be carried out at room temperature or under heating, but it is preferable to carry out the reaction at a temperature maintained at 10 to 60° C., as this allows a hydrolysate to be obtained in a short time and prevents a partial condensation reaction of the produced hydrolysate. The reaction time is not particularly limited and may be appropriately selected taking into consideration the reactivity of the silicon compound used, the composition of the reaction liquid obtained by mixing the silicon compound, acid, and water, and productivity.

[0052] In the second step of the method for producing silicon polymer particles, the raw material solution obtained in the first step is mixed with an alkaline aqueous medium to polycondense the particle precursor, thereby obtaining a polycondensation reaction solution. Here, the alkaline aqueous medium is a liquid obtained by mixing an alkaline component, water, and, if necessary, an organic solvent.

[0053] The alkaline component used in the alkaline aqueous medium is one whose aqueous solution is basic and acts as a neutralizer for the catalyst used in step 1 and as a catalyst for the polycondensation reaction in step 2. Examples of such alkaline components include alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, and potassium hydroxide; ammonia; and organic amines such as monomethylamine and dimethylamine.

[0054] The amount of the alkali component used is an amount that neutralizes the acid and effectively acts as a catalyst for the polycondensation reaction. For example, when ammonia is used as the alkali component, the amount is usually selected in the range of 0.01 parts by mass or more and 12.5 parts by mass or less per 100 parts by mass of the mixture of water and the organic solvent.

[0055] In the second step, in order to prepare an alkaline aqueous medium, an organic solvent may be used in addition to the alkaline component and water. The organic solvent is not particularly limited as long as it is compatible with water, but an organic solvent that dissolves 10 g or more of water per 100 g at room temperature and normal pressure is preferred.

[0056] Specific examples include alcohols such as methanol, ethanol, n-propanol, 2-propanol, and butanol; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, glycerin, trimethylolpropane, and hexanetriol; ethers such as ethylene glycol monoethyl ether, acetone, diethyl ether, tetrahydrofuran, and diacetone alcohol; and amide compounds such as dimethylformamide, dimethylacetamide, and N-methylpyrrolidone.

[0057] Among the organic solvents listed above, alcohol solvents such as methanol, ethanol, 2-propanol, butanol, etc. are preferred. Furthermore, from the viewpoint of hydrolysis and dehydration condensation reactions, it is more preferred to select as the organic solvent the same alcohol as the alcohol produced by elimination.

[0058] In the third step, the polycondensation reaction product obtained in the second step is mixed with an aqueous solution to form particles. Water (tap water, pure water, etc.) is preferably used as the aqueous solution, but components compatible with water, such as salts, acids, alkalis, organic solvents, surfactants, and water-soluble polymers, may also be added to the water. The temperatures of the polycondensation reaction liquid and the aqueous solution when mixed are not particularly limited, and are preferably selected in the range of 5 to 70°C, taking into consideration their compositions, productivity, etc.

[0059] The method for recovering particles can be any known method without any particular limitation. For example, a method of scooping floating powder or a filtration method can be mentioned, but filtration is preferred because of its simple operation. The filtration method is not particularly limited, and known devices such as vacuum filtration, centrifugal filtration, and pressure filtration can be selected. The filter paper, filter, filter cloth, etc. used for filtration are not particularly limited as long as they are industrially available, and can be appropriately selected depending on the device used.

[0060] The monomer used to synthesize the fine particle A of the composite particle can be appropriately selected based on its compatibility with the solvent and catalyst, its hydrolysis property, etc. Examples of the tetrafunctional silane monomer having the above structure (a) include tetramethoxysilane, tetraethoxysilane, and tetraisocyanatesilane, with tetraethoxysilane being preferred.

[0061] Examples of trifunctional silane monomers having the structure (b) include methyltrimethoxysilane, methyltriethoxysilane, methyldiethoxymethoxysilane, methylethoxydimethoxysilane, methyltrichlorosilane, methylmethoxydichlorosilane, methylethoxydichlorosilane, methyldimethoxychlorosilane, methylmethoxyethoxychlorosilane, methyldiethoxychlorosilane, methyltriacetoxysilane, methyldiacetoxymethoxysilane, methyldiacetoxyethoxysilane, methylacetoxydimethoxysilane, methylacetoxymethoxyethoxysilane, methylacetoxydiethoxysilane, methyltrihydroxysilane, methylmethoxydihydroxysilane, methylethoxydihydroxysilane, methyldimethoxyhydroxysilane, methylethoxymethoxyhydroxysilane, methyldiethoxyhydroxysilane, ethoxyhydroxysilane, methyldimethoxyhydroxysilane, methylethoxymethoxyhydroxysilane, methyldiethoxyhydroxysilane, Examples of such silane include ethyltrimethoxysilane, ethyltriethoxysilane, ethyltrichlorosilane, ethyltriacetoxysilane, ethyltrihydroxysilane, propyltrimethoxysilane, propyltriethoxysilane, propyltrichlorosilane, propyltriacetoxysilane, propyltrihydroxysilane, butyltrimethoxysilane, butyltriethoxysilane, butyltrichlorosilane, butyltriacetoxysilane, butyltrihydroxysilane, hexyltrimethoxysilane, hexyltriethoxysilane, hexyltrichlorosilane, hexyltriacetoxysilane, hexyltrihydroxysilane, phenyltrimethoxysilane, phenyltriethoxysilane, phenyltrichlorosilane, phenyltriacetoxysilane, and phenyltrihydroxysilane. Of these, methyltrimethoxysilane is preferred.

[0062] Examples of bifunctional silane monomers having the above structure (c) include di-tert-butyldichlorosilane, di-tert-butyldimethoxysilane, di-tert-butyldiethoxysilane, dibutyldichlorosilane, dibutyldimethoxysilane, dibutyldiethoxysilane, dichlorodecylmethylsilane, dimethoxydecylmethylsilane, diethoxydecylmethylsilane, dichlorodimethylsilane, dimethoxydimethylsilane, diethoxydimethylsilane, and diethyldimethoxysilane, and among these, dimethyldimethoxysilane is preferred.

[0063] For the fine particles B of the composite particles, inorganic fine particles such as silica fine particles, alumina fine particles, and titanium oxide fine particles can be suitably used, but silica fine particles or alumina fine particles are preferred. When the fine particles B are the above-mentioned fine particles, they have appropriate conductivity, which is preferable from the viewpoint of improving in-plane uniformity. They are also preferable from the viewpoint of durability and stability. Furthermore, silica fine particles are more preferred from the viewpoint of reactivity with the binder component constituting the fine particles A. The silica fine particles used in the present disclosure are particles mainly composed of silica (i.e., SiO2), and may be particles produced using silicon compounds such as water glass or alkoxysilane as raw materials, or may be particles obtained by pulverizing quartz.

[0064] Specific examples include silica particles prepared by the sol-gel method, precipitated silica particles prepared by a precipitation method, aqueous colloidal silica particles, fumed silica particles obtained by a gas-phase process, and fused silica particles. Among these, aqueous colloidal silica particles are preferred in terms of reactivity with the binder components and dispersion stability. Aqueous colloidal silica particles are commercially available or can be prepared from various starting materials by known methods. Aqueous colloidal silica particles can be prepared from silicic acid derived from an alkali silicate solution having a pH of about 9 to about 11, and silicate anions undergo polymerization to produce silica particles having the desired average particle size in the form of an aqueous dispersion.

[0065] The surface of the composite particles is preferably surface-treated with a hydrophobic treatment agent.The hydrophobic treatment agent is not particularly limited, but is preferably an organosilicon compound.For example, alkylsilazane compounds such as hexamethyldisilazane, alkylalkoxysilane compounds such as diethyldiethoxysilane, trimethylmethoxysilane, methyltrimethoxysilane, butyltrimethoxysilane, fluoroalkylsilane compounds such as trifluoropropyltrimethoxysilane, chlorosilane compounds such as dimethyldichlorosilane, trimethylchlorosilane, siloxane compounds such as octamethylcyclotetrasiloxane, silicone oil, silicone varnish, etc. can be mentioned.

[0066] By subjecting the surface of the composite particles to hydrophobic treatment, it is possible to suppress the change in electrostatic adhesion force of the toner after endurance testing. Among these, the composite particles are preferably surface-treated with at least one compound selected from the group consisting of alkylsilazane compounds, alkylalkoxysilane compounds, chlorosilane compounds, siloxane compounds, and silicone oils.Furthermore, from the above viewpoint, it is more preferable that the composite particles are surface-treated with an alkylsilazane compound.

[0067] The content of the composite particles is preferably 0.1 parts by mass or more and 10.0 parts by mass or less, and more preferably 0.2 parts by mass or more and 8.0 parts by mass or less, relative to 100 parts by mass of the toner particles, from the viewpoint of suppressing white spots and improving in-plane uniformity.

[0068] The adhesion rate of the composite particles to the toner particles is preferably 50% or more and 90% or less from the viewpoint of suppressing white spots and improving in-plane uniformity. The method for measuring the above physical properties will be described later.

[0069] [Magnetic Carrier] <Coating resin layer> It is important that the magnetic carrier used in the two-component developer of the present disclosure has a coating resin layer on the surface of the magnetic carrier core. As described above, it is also important that the coating resin layer has at least one structure selected from the structure represented by the following formula (A), the structure represented by the formula (B), and the structure represented by the formula (C). Cases in which a plurality of structures represented by formulas (A) to (C) are present are also included in the present disclosure.

[0070] [ka] (wherein X represents a carbon atom or a silicon atom. R a , R b each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms.

[0071] From the viewpoint of suppressing white spots and improving in-plane uniformity, it is more preferable that the film has a structure represented by formula (A).

[0072] The resin used in the coating resin layer can be any known resin, such as a silicone resin or vinyl resin, as long as it has a structure represented by the above formula (A), (B), or (C). Here, "silicone resin" refers to all commonly known silicone resins. Examples of silicone resins include straight silicone resins composed solely of organosiloxane bonds, and silicone resins (modified silicone resins) modified with alkyd, polyester, epoxy, acrylic, urethane, etc. Commercially available silicone resins can be used. Examples of commercially available straight silicone resins include KR271, KR255, and KR152 manufactured by Shin-Etsu Chemical Co., Ltd., and SR2400, SR2406, and SR2410 manufactured by Dow Corning Toray Silicones Co., Ltd. In this case, the silicone resin can be used alone, or other crosslinkable components, components for adjusting the charge amount, etc. can also be used simultaneously.

[0073] Furthermore, commercially available modified silicone resins include, for example, KR206 (alkyd-modified), KR5208 (acrylic-modified), ES1001N (epoxy-modified), and KR305 (urethane-modified), all manufactured by Shin-Etsu Chemical Co., Ltd., and SR2115 (epoxy-modified) and SR2110 (alkyd-modified), all manufactured by Dow Corning Toray Silicones Co., Ltd.

[0074] Furthermore, the vinyl resin is not particularly limited as long as it has the structure represented by the above formulas (A) to (C), but an acrylic resin having the structure represented by the above formula (A) is preferred from the viewpoint of suppressing white spots and improving in-plane uniformity.

[0075] Examples of monomers constituting the acrylic resin include methyl acrylate, methyl methacrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate (n-butyl, sec-butyl, iso-butyl, or tert-butyl; the same applies below), butyl methacrylate, 2-ethylhexyl acrylate, 2-ethylhexyl methacrylate, nonyl acrylate, or nonyl methacrylate. Furthermore, the monomer constituting the acrylic resin may also be a monomer containing a (meth)acrylic acid ester having an alicyclic hydrocarbon group, such as cyclobutyl acrylate, cyclopentyl acrylate, cyclohexyl acrylate, cycloheptyl acrylate, dicyclopentenyl acrylate, dicyclopentanyl acrylate, cyclobutyl methacrylate, cyclopentyl methacrylate, cyclohexyl methacrylate, cycloheptyl methacrylate, dicyclopentenyl methacrylate, and dicyclopentanyl methacrylate. Furthermore, a macromonomer may also be used as the monomer constituting the acrylic resin. The macromonomer may be a macromonomer that is a polymer of at least one monomer selected from the group consisting of methyl acrylate, methyl methacrylate, butyl acrylate, butyl methacrylate, 2-ethylhexyl acrylate, and 2-ethylhexyl methacrylate. One or more of the above monomers may be selected and used. Among the above monomers, it is preferable to use a (meth)acrylic acid ester monomer having an alicyclic hydrocarbon group with 4 to 8 carbon atoms, a (meth)acrylic acid ester monomer having an alkyl group with 1 to 8 carbon atoms, and the above-mentioned macromonomer.

[0076] The resin used for the coating resin layer is preferably a copolymer obtained by radical polymerization of the above-mentioned monomers. One or more selected monomers may be used for the copolymer. More preferably, the coating resin layer has a structure represented by the above formula (A), and is a copolymer of a monomer containing a (meth)acrylic acid ester monomer having an alicyclic hydrocarbon group or a (meth)acrylic acid monomer having an alkyl group having 1 to 8 carbon atoms.

[0077] The ester group concentration of the acrylic resin having the structure of the above formula (A) is preferably 5.0 mmol / g or more and 11.0 mmol / g or less from the viewpoint of suppressing white spots and improving in-plane uniformity.

[0078] Furthermore, when the value of the middle part of the above formula (9) in the above composite particle is α and the ester group concentration of the acrylic resin is β (mmol / g), it is preferable that the following formula (11) is satisfied.

number

[0079] By setting β / α within this range, the interaction between the composite particles and the coating resin layer is further improved, making it possible to suppress white spots and improve in-plane uniformity.

[0080] <Magnetic carrier core> Next, the magnetic carrier core will be described.

[0081] As the magnetic carrier core, a known magnetic carrier core can be used. It is more preferable to use magnetic material-dispersed resin particles in which a magnetic material is dispersed in a resin component, or porous magnetic core particles containing a resin in the voids.

[0082] These can reduce the true density of the magnetic carrier, thereby reducing the load on the toner. This reduces image quality degradation even over long periods of use and reduces the frequency of replacing the developer, which is composed of toner and carrier. However, the present disclosure is not limited to the above, and the effects of the present disclosure can be fully achieved even when commercially available magnetic carrier cores are used.

[0083] The magnetic material component used in the magnetic material-dispersed resin particles may be any of various magnetic iron compound particles, such as magnetite particles, maghemite particles, or magnetic iron oxide particles containing at least one selected from silicon oxide, silicon hydroxide, aluminum oxide, and aluminum hydroxide; magnetoplumbite ferrite particles containing barium, strontium, or barium-strontium; and spinel ferrite particles containing at least one selected from manganese, nickel, zinc, lithium, and magnesium.

[0084] Among these, magnetic iron oxide particles are preferably used.

[0085] In addition to the magnetic material component, non-magnetic inorganic compound particles such as non-magnetic iron oxide particles such as hematite particles, non-magnetic ferric oxide hydrous particles such as goethite particles, titanium oxide particles, silica particles, talc particles, alumina particles, barium sulfate particles, barium carbonate particles, cadmium yellow particles, calcium carbonate particles, and zinc oxide particles may be used in combination with the magnetic iron compound particles.

[0086] When the magnetic iron compound particles and the non-magnetic inorganic compound particles are mixed and used, the mixing ratio of these is preferably such that the magnetic iron compound particles account for at least 30 mass %.

[0087] The magnetic iron compound particles are preferably treated in whole or in part with a lipophilic treatment agent. The lipophilic treatment agent used in this case may be an organic compound having one or more functional groups selected from the group consisting of epoxy, amino, mercapto, organic acid, ester, ketone, halogenated alkyl, and aldehyde groups, or a mixture thereof. The organic compound having a functional group is preferably a coupling agent, more preferably a silane coupling agent, titanium coupling agent, or aluminum coupling agent, with silane coupling agents being particularly preferred.

[0088] The binder resin constituting the magnetic material dispersed resin particles is preferably a thermosetting resin. For example, phenol resin, epoxy resin, unsaturated polyester resin, etc. are available, but phenol resin is preferred because it is inexpensive and easy to manufacture, such as phenol-formaldehyde resin.

[0089] The content ratio of the binder resin to the magnetic iron compound particles (or a mixture of the magnetic iron compound particles and the non-magnetic inorganic compound particles) is preferably 1% by mass or more and 20% by mass or less of the binder resin and 80% by mass or more and 99% by mass or less of the magnetic iron compound particles (or the mixture).

[0090] Next, a method for producing the magnetic material-dispersed resin particles will be described.

[0091] As described in the Examples below, for example, composite particles can be produced by stirring phenols and aldehydes in an aqueous medium in the presence of magnetic or non-magnetic inorganic compound particles and a basic catalyst, followed by reacting and curing the phenols and aldehydes to produce composite particles containing inorganic compound particles such as magnetic iron oxide particles and a phenolic resin.

[0092] Alternatively, the magnetic carrier can be produced by a so-called kneading and grinding method in which a binder resin containing inorganic compound particles such as magnetic iron oxide particles is ground. The former method is preferred in order to easily control the particle size of the magnetic carrier and to obtain a sharp particle size distribution.

[0093] Next, the porous magnetic core particles will be described.

[0094] The material of the porous magnetic core particles is preferably magnetite or ferrite, and more preferably ferrite, since this allows the porous structure of the porous magnetic core particles to be controlled and the resistance to be adjusted.

[0095] Ferrite is a sintered body represented by the following general formula: (M12O) x (M2O) y (Fe2O3) z (In the formula, M1 is a monovalent metal, M2 is a divalent metal, and when x + y + z = 1.0, x and y are each 0≦(x, y)≦0.8, and z is 0.2 <z<1.0である。)

[0096] In the formula, M1 and M2 preferably use at least one metal atom selected from the group consisting of Li, Fe, Mn, Mg, Sr, Cu, Zn, and Ca. In addition, Ni, Co, Ba, Y, V, Bi, In, Ta, Zr, B, Mo, Na, Sn, Ti, Cr, Al, Si, and rare earth elements can also be used.

[0097] In the case of magnetic carriers, it is preferable to control the surface roughness of the porous magnetic core particles to maintain an appropriate level of magnetization and to set the pore diameter within a desired range. It is also preferable to be able to easily control the rate of the ferritization reaction and to suitably control the resistivity and magnetic force of the porous magnetic core. From these viewpoints, Mn-based ferrites, Mn-Mg-based ferrites, Mn-Mg-Sr-based ferrites, and Li-Mn-based ferrites containing Mn element are more preferable.

[0098] The manufacturing process when porous ferrite particles are used as the magnetic carrier core will be described in detail below.

[0099] [Process 1 (weighing and mixing process)] The raw materials for the ferrite are weighed and mixed.

[0100] Examples of ferrite raw materials include metal particles of the above metal elements, or oxides, hydroxides, oxalates, carbonates, and the like thereof.

[0101] Examples of mixing devices include a ball mill, a planetary mill, a Giotto mill, and a vibration mill. A ball mill is particularly preferred from the viewpoint of mixability. Specifically, weighed ferrite raw material and balls are placed in a ball mill, and the mixture is pulverized and mixed for preferably 0.1 to 20.0 hours.

[0102] [Step 2 (pre-firing step)] The crushed and mixed ferrite raw material is calcined in air or a nitrogen atmosphere, preferably at a calcination temperature of 700°C to 1200°C for preferably 0.5 to 5.0 hours to form ferrite. For calcination, the following furnaces are used, for example: burner-type incinerator, rotary-type calciner, electric furnace, etc.

[0103] [Process 3 (Crushing process)] The calcined ferrite produced in step 2 is pulverized in a pulverizer. There are no particular limitations on the pulverizer as long as the desired particle size can be obtained. Examples include crushers, hammer mills, ball mills, bead mills, planetary mills, and Giotto mills.

[0104] In order to obtain a pulverized ferrite product with a desired particle size, it is preferable to control the material, particle size, and operating time of the balls and beads used in a ball mill or a bead mill. Specifically, to reduce the particle size of the calcined ferrite slurry, balls with a heavy specific gravity can be used or the milling time can be extended. Furthermore, to widen the particle size distribution of the calcined ferrite, balls or beads with a heavy specific gravity can be used and the milling time can be shortened. Furthermore, calcined ferrite with a wide particle size distribution can also be obtained by mixing multiple calcined ferrites with different particle sizes.

[0105] In addition, when using a ball mill or bead mill, the wet method is more preferable than the dry method because the crushed product does not fly up inside the mill and the crushing efficiency is higher.

[0106] [Process 4 (granulation process)] To the pulverized calcined ferrite, water, a binder, and, if necessary, a pore adjuster, such as a foaming agent or resin particles, are added.

[0107] Examples of foaming agents include sodium hydrogen carbonate, potassium hydrogen carbonate, lithium hydrogen carbonate, ammonium hydrogen carbonate, sodium carbonate, potassium carbonate, lithium carbonate, and ammonium carbonate.

[0108] Examples of resin microparticles include polyester, polystyrene, styrene copolymers such as styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, and styrene-acrylonitrile-indene copolymer; polyvinyl chloride, phenolic resin, modified phenolic resin, maleic resin, acrylic resin, methacrylic resin, polyvinyl acetate, and silicone resin; polyester resin having, as a structural unit, a monomer selected from aliphatic polyhydric alcohols, aliphatic dicarboxylic acids, aromatic dicarboxylic acids, aromatic dialcohols, and diphenols; polyurethane resin, polyamide resin, polyvinyl butyral, terpene resin, coumarone-indene resin, petroleum resin, and hybrid resin having a polyester unit and a vinyl polymer unit.

[0109] As the binder, for example, polyvinyl alcohol is used.

[0110] In step 3, when wet pulverization is performed, it is preferable to add a binder and, if necessary, a pore adjuster, taking into consideration the water contained in the ferrite slurry.

[0111] The obtained ferrite slurry is dried and granulated using a spray dryer, preferably in a heated atmosphere at 100° C. to 200° C. The spray dryer is not particularly limited as long as it can obtain the desired particle size of the porous magnetic core particles. For example, a spray dryer can be used.

[0112] [Step 5 (baking process)] Next, the granulated product is fired preferably at a temperature of 800° C. or higher and 1400° C. or lower, preferably for 1 hour or higher and 24 hours or lower.

[0113] By increasing the firing temperature and lengthening the firing time, the firing of the porous magnetic core particles progresses, resulting in a smaller pore size and a reduced number of pores.

[0114] [Process 6 (Sorting Process)] After the calcined particles are crushed as described above, they may be classified or sieved to remove coarse particles and fine particles, if necessary.

[0115] The volume distribution based 50% particle size (D50) of the magnetic core particles is preferably 18.0 μm or more and 68.0 μm or less.

[0116] [Process 7 (filling process)] The physical strength of porous magnetic core particles may be reduced depending on the internal pore volume, and therefore, in order to increase the physical strength as a magnetic carrier, it is preferable to fill at least a portion of the voids of the porous magnetic core particles with a resin. The amount of resin filled in the porous magnetic core particles is preferably 2% by mass or more and 15% by mass or less of the porous magnetic core particles.

[0117] As long as there is little variation in the resin content of each magnetic carrier, it is acceptable for the resin to fill only a portion of the internal voids, for the resin to fill only the voids near the surface of the porous magnetic core particle and leave voids inside, or for the internal voids to be completely filled with resin.

[0118] The method for filling the voids of the porous magnetic core particles with a resin is not particularly limited, but examples thereof include a method in which the porous magnetic core particles are impregnated with a resin solution by a coating method such as a dipping method, a spraying method, a brush coating method, or a fluidized bed coating method, and then the solvent is evaporated. Alternatively, a method in which the resin is diluted in a solvent and then added to the voids of the porous magnetic core particles can be used.

[0119] The solvent used here may be any solvent that can dissolve the resin. In the case of a resin that is soluble in an organic solvent, examples of the organic solvent include toluene, xylene, cellosolve butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, and methanol. In the case of a water-soluble resin or an emulsion-type resin, water may be used as the solvent.

[0120] The amount of resin solids in the resin solution is preferably 1% by mass or more and 50% by mass or less, more preferably 1% by mass or more and 30% by mass or less. If it is 50% by mass or less, the viscosity is not too high and the resin solution easily penetrates uniformly into the voids of the porous magnetic core particles. On the other hand, if it is 1% by mass or more, the amount of resin is appropriate, and the adhesion of the resin to the porous magnetic core particles is good.

[0121] The resin to be filled into the voids of the porous magnetic core particles may be either a thermoplastic resin or a thermosetting resin. It is preferable that the resin has a high affinity for the porous magnetic core particles. When a resin with a high affinity is used, the surface of the porous magnetic core particles can be covered with the resin at the same time as the resin is filled into the voids of the porous magnetic core particles.

[0122] Examples of the resin to be filled include the following thermoplastic resins: novolac resin, saturated alkyl polyester resin, polyarylate, polyamide resin, and acrylic resin.

[0123] Examples of the thermosetting resin include phenolic resins, epoxy resins, unsaturated polyester resins, and silicone resins.

[0124] The method for coating the surfaces of the magnetic carrier core particles with a resin is not particularly limited, but examples thereof include coating methods such as dipping, spraying, brushing, dry coating, and fluidized bed coating.

[0125] The content of the resin coating layer of the magnetic carrier is preferably 0.5 to 3.5 parts by mass per 100 parts by mass of magnetic carrier core particles, from the viewpoint of suppressing white spots and improving in-plane uniformity.

[0126] Furthermore, the resin coating layer may contain conductive particles or particles or materials having charge control properties. Examples of conductive particles include carbon black, magnetite, graphite, zinc oxide, and tin oxide.

[0127] The amount of conductive particles added is preferably 0.1 parts by mass or more and 10.0 parts by mass or less relative to 100 parts by mass of the coating resin in order to adjust the resistance of the magnetic carrier.

[0128] Examples of particles having charge control properties include organic metal complex particles, organic metal salt particles, chelate compound particles, monoazo metal complex particles, acetylacetone metal complex particles, hydroxycarboxylic acid metal complex particles, polycarboxylic acid metal complex particles, polyol metal complex particles, polymethyl methacrylate resin particles, polystyrene resin particles, melamine resin particles, phenolic resin particles, nylon resin particles, silica particles, titanium oxide particles, and alumina particles.

[0129] The amount of particles having charge control properties added is preferably 0.5 parts by mass or more and 50.0 parts by mass or less per 100 parts by mass of the coating resin in order to adjust the amount of triboelectric charge.

[0130] [Toner particles and toner] <Materials that make up toner particles> [Binder resin] The toner particles contain a binder resin, and known binder resins can be used for the toner particles. For example, the binder resins include the following:

[0131] Styrene-based resins, styrene-based copolymer resins, polyester resins, polyol resins, polyvinyl chloride resins, phenolic resins, natural resin-modified phenolic resins, natural resin-modified maleic acid resins, acrylic resins, methacrylic resins, polyvinyl acetate, silicone resins, polyurethane resins, polyamide resins, furan resins, epoxy resins, xylene resins, polyvinyl butyral, terpene resins, coumarone-indene resins, and petroleum-based resins. Preferred resins include styrene-based copolymer resins, polyester resins, and hybrid resins in which polyester resins and styrene-based copolymer resins are mixed or partially reacted, with polyester resins being more preferred.

[0132] The components constituting the polyester resin will be described in detail below. Note that the following components may be used singly or in combination depending on the type and application.

[0133] Examples of the divalent carboxylic acid component constituting the polyester resin include the following dicarboxylic acids or derivatives thereof: benzenedicarboxylic acids such as phthalic acid, terephthalic acid, isophthalic acid, and phthalic anhydride, or their anhydrides or lower alkyl esters; alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid, and azelaic acid, or their anhydrides or lower alkyl esters; alkenylsuccinic acids or alkylsuccinic acids having an average carbon number of 1 to 50, or their anhydrides or lower alkyl esters; and unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, and itaconic acid, or their anhydrides or lower alkyl esters.

[0134] The alkyl group in the lower alkyl ester includes a methyl group, an ethyl group, a propyl group, and an isopropyl group.

[0135] On the other hand, examples of the dihydric alcohol component constituting the polyester resin include the following.

[0136] Ethylene glycol, polyethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 2-ethyl-1,3-hexanediol, 1,4-cyclohexanedimethanol (CHDM), hydrogenated bisphenol A, bisphenols represented by formula (I-1) and derivatives thereof, and diols represented by formula (I-2).

[0137] [ka] (In formula (I-1), R represents an ethylene group or a propylene group, x and y each represent an integer of 0 or more, and the average value of x+y is 0 or more and 10 or less.)

[0138] [ka] (In formula (I-2), R' is an ethylene group or a propylene group, x' and y' are each an integer of 0 or more, and the average value of x'+y' is 0 or more and 10 or less.)

[0139] The constituent components of the polyester resin may contain, in addition to the above-mentioned divalent carboxylic acid component and divalent alcohol component, a trivalent or higher carboxylic acid component and a trivalent or higher alcohol component.

[0140] The trivalent or higher carboxylic acid component is not particularly limited, but examples thereof include trimellitic acid, trimellitic anhydride, pyromellitic acid, etc. Furthermore, the trivalent or higher alcohol component includes trimethylolpropane, pentaerythritol, glycerin, etc.

[0141] The polyester resin may contain, in addition to the above-mentioned compounds, a monocarboxylic acid component and a monoalcohol component as constituent components. Specific examples of the monocarboxylic acid component include palmitic acid, stearic acid, arachidic acid, behenic acid, cerotic acid, heptacosanoic acid, montanic acid, melissic acid, lacteric acid, tetracontanoic acid, and pentacontanoic acid.

[0142] Furthermore, examples of the monohydric alcohol component include behenyl alcohol, ceryl alcohol, melissyl alcohol, and tetracontanol.

[0143] [Coloring agent] As black pigments, carbon black such as furnace black, channel black, acetylene black, thermal black, and lamp black is used, and magnetic powder such as magnetite and ferrite is also used.

[0144] Suitable colorants for the yellow color include pigments or dyes, such as CI Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 17, 23, 62, 65, 73, 74, 81, 83, 93, 94, 95, 97, 98, 109, 110, 111, 117, 120, 127, 128, 129, 137, 138, 139, 147, 151, 154, 155, 167, 168, 173, 174, 176, 180, 181, 183, and 191, and CI Vat Yellow 1, 3, and 20. Examples of dyes include CI Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, and 162. These may be used alone or in combination of two or more.

[0145] Suitable colorants for cyan include pigments and dyes. Examples of pigments include CI Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 16, 17, 60, 62, and 66, CI Vat Blue 6, and CI Acid Blue 45. Examples of dyes include CI Solvent Blue 25, 36, 60, 70, 93, and 95. These may be used alone or in combination.

[0146] Suitable colorants for magenta include pigments and dyes, such as CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 48:2, 48:3, 48:4, 49, 50, 51, 52, 53, 54, 55, 57, 57:1, 58, 60, 63, 64, 68, 81, 81:1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 144, 146, 150, 163, 166, 169, 177, 184, 185, 202, 206, 207, 209, 220, 221, 238, 254, etc.; CI Pigment Violet 19; CI Bat Red 1, 2, 10, 13, 15, 23, 29, 35.

[0147] Examples of magenta dyes include oil-soluble dyes such as CI Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 52, 58, 63, 81, 82, 83, 84, 100, 109, 111, 121, and 122, CI Disperse Red 9, CI Solvent Violet 8, 13, 14, 21, and 27, and CI Disperse Violet 1; and basic dyes such as CI Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, and 40, and CI Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, and 28. These dyes can be used alone or in combination of two or more.

[0148] The content of the colorant is preferably 1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass of the binder resin.

[0149] [Release agent] A release agent (wax) may be used to impart releasability to the toner.

[0150] Examples of waxes include: aliphatic hydrocarbon waxes such as low-molecular-weight polyethylene, low-molecular-weight polypropylene, olefin copolymers, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; oxidized waxes of aliphatic hydrocarbon waxes such as oxidized polyethylene wax; waxes containing fatty acid esters as the main component such as carnauba wax, behenyl behenate, and Montan acid ester wax; and partially or completely deoxidized fatty acid esters such as deoxidized carnauba wax.

[0151] Furthermore, saturated straight-chain fatty acids such as palmitic acid, stearic acid, and montanic acid; unsaturated fatty acids such as brassidic acid, eleostearic acid, and valinaric acid; saturated alcohols such as stearyl alcohol, aralkyl alcohol, behenyl alcohol, carnaubyl alcohol, ceryl alcohol, and melissyl alcohol; polyhydric alcohols such as sorbitol; fatty acid amides such as linoleic acid amide, oleic acid amide, and lauric acid amide; saturated fatty acid bisamides such as methylene bisstearic acid amide, ethylene biscapric acid amide, ethylene bislauric acid amide, and hexamethylene bisstearic acid amide; ethylene bisoleic acid amide, hexamethylene bisoleic acid amide, N,N Examples of suitable fatty acid amides include unsaturated fatty acid amides such as N,N'-dioleyl adipamide and N,N'-dioleyl sebacamide; aromatic bisamides such as m-xylene bisstearamide and N,N'-distearyl isophthalamide; fatty acid metal salts (commonly known as metal soaps) such as calcium stearate, calcium laurate, zinc stearate, and magnesium stearate; waxes grafted onto aliphatic hydrocarbon waxes using vinyl copolymerizable monomers such as styrene and acrylic acid; partial esters of fatty acids and polyhydric alcohols such as behenic acid monoglyceride; and methyl ester compounds having hydroxy groups obtained by hydrogenating vegetable oils and fats.

[0152] Particularly preferred waxes are aliphatic hydrocarbon waxes, such as low-molecular-weight hydrocarbons obtained by radical polymerization of alkylene under high pressure or polymerization under low pressure with a Ziegler catalyst or a metallocene catalyst, Fischer-Tropsch wax synthesized from coal or natural gas, paraffin wax, olefin polymers obtained by thermal decomposition of high-molecular-weight olefin polymers, synthetic hydrocarbon waxes obtained from the distillation residue of hydrocarbons obtained by the Arge process from synthesis gas containing carbon monoxide and hydrogen, and synthetic hydrocarbon waxes obtained by hydrogenating these.

[0153] Furthermore, hydrocarbon waxes fractionated by press sweating, solvent method, vacuum distillation, or fractional crystallization are more preferably used. Among paraffin waxes, n-paraffin wax and Fischer-Tropsch wax, which are mainly composed of linear components, are particularly preferred from the viewpoint of molecular weight distribution.

[0154] These waxes may be used alone or in combination of two or more kinds. The wax is preferably added in an amount of 1 part by mass to 20 parts by mass per 100 parts by mass of the binder resin.

[0155] [Charge control agent] A charge control agent may be used in the toner. Known charge control agents can be used. Examples include azo-based iron compounds, azo-based chromium compounds, azo-based manganese compounds, azo-based cobalt compounds, azo-based zirconium compounds, chromium compounds of carboxylic acid derivatives, zinc compounds of carboxylic acid derivatives, aluminum compounds of carboxylic acid derivatives, and zirconium compounds of carboxylic acid derivatives. The carboxylic acid derivative is preferably an aromatic hydroxycarboxylic acid. Charge control resins can also be used. If necessary, one or more types of charge control agents may be used in combination. It is preferable to use 0.1 to 10 parts by weight of the charge control agent per 100 parts by weight of the binder resin.

[0156] <Inorganic fine powder> In addition to the composite particles, the toner may contain multiple other inorganic fine powders in combination as needed. The inorganic fine powders may be added internally to the toner particles or may be mixed with the toner base particles as an external additive. As the external additive, inorganic fine powders such as silica are preferred. The inorganic fine powders are preferably hydrophobized with a hydrophobizing agent such as a silane compound, silicone oil, or a mixture thereof.

[0157] As an external additive to improve fluidity, 2 / g or more 400m 2In order to simultaneously improve the flowability and stabilize the durability, inorganic fine particles having a specific surface area within the above range may be used in combination.

[0158] The inorganic fine powder is preferably used in an amount of 0.1 to 10.0 parts by mass relative to 100 parts by mass of toner particles. When this range is satisfied, the effect of durability and stability is easily obtained.

[0159] <Method of manufacturing toner particles> In the step of obtaining toner particles, the method for producing the toner particles is not particularly limited, and the toner particles can be produced by a known method, such as a pulverization method, an emulsion aggregation method, a suspension polymerization method, or a solution suspension method.

[0160] [Crushing method] Toner particles produced by a pulverization method are produced, for example, as follows.

[0161] The binder resin, colorant, and other additives, if necessary, are thoroughly mixed using a mixer such as a Henschel mixer or a ball mill. The mixture is then melt-kneaded using a thermal kneader such as a twin-screw kneading extruder, a heated roll, a kneader, or an extruder. Wax, magnetic iron oxide particles, and a metal-containing compound may also be added during this process.

[0162] The molten mixture is cooled and solidified, and then pulverized and classified to obtain toner particles. The immersion rate of silica fine particles on the toner particle surface can be controlled by adjusting the exhaust temperature during pulverization. The toner particles and external additives such as silica fine particles are mixed in a mixer such as a Henschel mixer to obtain the toner.

[0163] Examples of mixers include the following: Henschel mixer (manufactured by Mitsui Mining Co., Ltd.); Super mixer (manufactured by Kawata Corporation); Ribocone (manufactured by Okawara Manufacturing Co., Ltd.); Nauta mixer, Turbulizer, Cyclomix (manufactured by Hosokawa Micron Corporation); Spiral pin mixer (manufactured by Pacific Machinery Works Co., Ltd.); and Lödige mixer (manufactured by Matsubo Corporation).

[0164] Examples of kneaders include the following: KRC kneader (manufactured by Kurimoto Iron Works); Buss-Co kneader (manufactured by Buss); TEM type extruder (manufactured by Toshiba Machine Co., Ltd.); TEX twin-screw kneader (manufactured by The Japan Steel Works); PCM kneader (manufactured by Ikegai Iron Works); three-roll mill, mixing roll mill, kneader (manufactured by Inoue Seisakusho); Kneadex (manufactured by Mitsui Mining Co., Ltd.); MS-type pressure kneader, kneader-ruder (manufactured by Moriyama Seisakusho); and Banbury mixer (manufactured by Kobe Steel, Ltd.).

[0165] Examples of pulverizers include the following: Counter Jet Mill, Micron Jet, and Innomizer (manufactured by Hosokawa Micron Corporation); IDS-type mill and PJM jet pulverizer (manufactured by Nippon Pneumatic Mfg. Co., Ltd.); Cross Jet Mill (manufactured by Kurimoto Iron Works); Urmax (manufactured by Nisso Engineering Co., Ltd.); SK Jet-O-Mill (manufactured by Seishin Enterprise Co., Ltd.); Cryptron (manufactured by Kawasaki Heavy Industries, Ltd.); Turbo Mill (manufactured by Turbo Kogyo Co., Ltd.); and Super Rotor (manufactured by Nisshin Engineering Co., Ltd.).

[0166] Furthermore, if necessary, after pulverization, the toner particles may be surface-treated using a Hybridization System (manufactured by Nara Machinery Works), Nobilta (manufactured by Hosokawa Micron Corporation), Mechanofusion System (manufactured by Hosokawa Micron Corporation), Faculty (manufactured by Hosokawa Micron Corporation), Innomizer (manufactured by Hosokawa Micron Corporation), Theta Composer (manufactured by Tokuju Kogyosho Co., Ltd.), Mechanomill (manufactured by Okada Seiko Co., Ltd.), or Meteoraidbow MR Type (manufactured by Nippon Pneumatic Co., Ltd.) to control the embedding rate of silica microparticles on the toner particle surface.

[0167] Examples of classifiers include the following: Cruseal, Micron Classifier, and Spedic Classifier (manufactured by Seishin Enterprise Co., Ltd.); Turbo Classifier (manufactured by Nisshin Engineering Co., Ltd.); Micron Separator, Turboplex (ATP), and TSP Separator (manufactured by Hosokawa Micron Corporation); Elbow Jet (manufactured by Nittetsu Mining Co., Ltd.), and Dispersion Separator (manufactured by Nippon Pneumatic Mfg. Co., Ltd.); and YM Microcut (manufactured by Yaskawa Corporation).

[0168] Examples of sieving devices used to sift out coarse particles include the following: Ultrasonic (manufactured by Koei Sangyo Co., Ltd.); Resonaseave, Gyroshifter (Tokuju Kogyosho Co., Ltd.); Vibrasonic system (manufactured by Dalton Co., Ltd.); Soniclean (manufactured by Shinto Kogyo Co., Ltd.); Turboscreener (manufactured by Turbo Industry Co., Ltd.); Microshifter (manufactured by Makino Sangyo Co., Ltd.); circular vibrating sieve.

[0169] [Emulsification aggregation method] By the emulsion aggregation method, toner particles are produced, for example, as follows.

[0170] A process for preparing a resin particle dispersion (preparation process): For example, a polyester resin or a styrene-acrylic resin as a binder resin component is dissolved in an organic solvent to form a uniform solution. Then, a basic compound or a surfactant is added as needed. An aqueous medium is slowly added to this solution while applying shear force using a homogenizer or the like to form resin microparticles of the binder resin. Finally, the organic solvent is removed to produce a resin microparticle dispersion in which the resin microparticles are dispersed.

[0171] When preparing the resin microparticle dispersion, the amount of resin component dissolved in the organic solvent is preferably 10 parts by mass or more and 50 parts by mass or less, and more preferably 30 parts by mass or more and 50 parts by mass or less, per 100 parts by mass of the organic solvent.

[0172] Any organic solvent can be used as long as it can dissolve the resin component, but solvents that have high solubility for olefin resins, such as toluene, xylene, and ethyl acetate, are preferred.

[0173] The surfactant is not particularly limited, and examples thereof include anionic surfactants such as sulfate salts, sulfonates, carboxylates, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycols, alkylphenol ethylene oxide adducts, and polyhydric alcohols.

[0174] Examples of the basic compound include inorganic bases such as sodium hydroxide and potassium hydroxide, and organic bases such as triethylamine, trimethylamine, dimethylaminoethanol, diethylaminoethanol, etc. The basic compound may be used alone or in combination of two or more.

[0175] ·Agglomeration process: The aggregation process is a process in which, for example, the above-mentioned resin microparticle dispersion is mixed with a colorant microparticle dispersion, a wax microparticle dispersion, and a silicone oil emulsion, as necessary, to prepare a mixed liquid, and then the microparticles contained in the prepared mixed liquid are aggregated to form aggregate particles.

[0176] A suitable example of a method for forming aggregate particles is a method in which an aggregating agent is added to and mixed with the above-mentioned mixed liquid, and the temperature is increased or mechanical power is appropriately applied.

[0177] The colorant particle dispersion is prepared by dispersing the colorant described above. The colorant particles are dispersed by a known method, and for example, a media-type disperser such as a rotary shear homogenizer, a ball mill, a sand mill, or an attritor, or a high-pressure counter-collision type disperser is preferably used. Furthermore, a surfactant or a polymer dispersant that imparts dispersion stability can be added as needed.

[0178] Wax microparticle dispersion and silicone oil emulsion are prepared by dispersing each material in aqueous medium.Each material is dispersed by known methods, for example, preferably using a media-type disperser such as a rotary shear homogenizer, a ball mill, a sand mill, an attritor, or a high-pressure counter-collision type disperser.In addition, if necessary, surfactants or polymer dispersants that provide dispersion stability can be added.

[0179] Examples of the flocculant include metal salts of monovalent metals such as sodium and potassium, metal salts of divalent metals such as calcium and magnesium, metal salts of trivalent metals such as iron and aluminum, and polyvalent metal salts such as polyaluminum chloride. From the viewpoint of particle size controllability in the flocculation step, metal salts of divalent metals such as calcium chloride and magnesium sulfate are preferred.

[0180] The addition and mixing of the flocculant is preferably carried out at a temperature ranging from room temperature to 75°C. When the mixing is carried out under these temperature conditions, the flocculation proceeds in a stable state. The mixing can be carried out using a known mixing device, homogenizer, mixer, etc.

[0181] ·Fusion process: The fusion step is a step in which the aggregate particles are fused by heating, preferably at a temperature equal to or higher than the melting point of the olefin-based resin, to produce particles having smooth surfaces of the aggregate particles.

[0182] Before the fusion step, a chelating agent, a pH adjuster, a surfactant, etc. may be added as needed to prevent fusion between the resulting resin particles.

[0183] Examples of chelating agents include ethylenediaminetetraacetic acid (EDTA) and its alkali metal salts such as the Na salt, sodium gluconate, sodium tartrate, potassium and sodium citrate, nitrilotriacetate (NTA) salts, and many water-soluble polymers containing both COOH and OH functionality (polyelectrolytes).

[0184] The fusion process requires a shorter time if the heating temperature is high, but a longer time if the heating temperature is low. That is, the heat fusion time depends on the heating temperature and cannot be generally determined, but is generally about 10 minutes to 10 hours.

[0185] ·Cooling process: This is a step of cooling the temperature of the aqueous medium containing the resin particles obtained in the fusion step. Although not particularly limited, the specific cooling rate is about 0.1 to 50°C / min.

[0186] Cleaning process: The resin particles produced through the above steps can be repeatedly washed and filtered to remove impurities from the resin particles.

[0187] Specifically, it is preferable to wash the resin particles with an aqueous solution containing a chelating agent such as ethylenediaminetetraacetic acid (EDTA) and its Na salt, and then wash the resin particles with pure water.

[0188] By repeating washing with pure water and filtration multiple times, metal salts, surfactants, etc. in the resin particles can be removed. The number of filtrations is preferably 3 to 20 times, more preferably 3 to 10 times, from the viewpoint of production efficiency.

[0189] ·Drying and classification process: The washed resin particles are dried and then appropriately classified to obtain toner particles.

[0190] [Dissolution suspension method] Toner particles produced by the solution suspension method are produced, for example, as follows.

[0191] In the solution suspension method, a resin composition obtained by dissolving a binder resin component such as a polyester resin or a styrene-acrylic resin in an organic solvent is dispersed in an aqueous medium to granulate particles of the resin composition, and then the organic solvent contained in the particles of the resin composition is removed to produce toner particles.

[0192] The dissolution suspension method can be applied to any resin component that dissolves in an organic solvent, and the shape can be easily controlled by adjusting the conditions for removing the solvent.

[0193] A specific method for producing a toner using a solution suspension method will be described below, but the method is not limited to this.

[0194] ·Resin component dissolution process: In the resin component dissolving step, a binder resin and, if necessary, other components such as a colorant, wax, and silicone oil are dissolved or dispersed in an organic solvent to prepare a resin composition.

[0195] The organic solvent used may be any solvent capable of dissolving the resin component. Specific examples include toluene, xylene, chloroform, methylene chloride, and ethyl acetate. Toluene and ethyl acetate are preferred because of their ability to promote crystallization of the crystalline resin and ease of solvent removal.

[0196] The amount of the organic solvent used is not limited, but may be an amount that allows the resin composition to be dispersed in a poor medium such as water and has a viscosity that allows granulation. Specifically, from the viewpoint of granulation properties and production efficiency of toner particles, a mass ratio of the organic solvent to the resin component and, if necessary, other components such as a colorant, wax, and silicone oil is preferably 10 / 90 to 50 / 50.

[0197] On the other hand, the colorant, wax, and silicone oil do not need to be dissolved in the organic solvent and may be dispersed. When the colorant, wax, and silicone oil are used in a dispersed state, they are preferably dispersed using a dispersing machine such as a bead mill.

[0198] ·Granulation process: The granulation step is a step of preparing particles of the resin composition by dispersing the obtained resin composition in an aqueous medium using a dispersant so as to give a predetermined toner particle size.

[0199] As the aqueous medium, water is mainly used.

[0200] The aqueous medium preferably contains 1% by mass or more and 30% by mass or less of a monovalent metal salt, which inhibits the organic solvent in the resin composition from diffusing into the aqueous medium and enhances the crystallinity of the resin component contained in the resulting toner particles.

[0201] As a result, the toner tends to have good blocking resistance and good particle size distribution.

[0202] Examples of monovalent metal salts include sodium chloride, potassium chloride, lithium chloride, and potassium bromide, and among these, sodium chloride and potassium chloride are preferred.

[0203] The mixing ratio (mass ratio) of the aqueous medium to the resin composition is preferably aqueous medium / resin composition=90 / 10 to 50 / 50.

[0204] The dispersant is not particularly limited, but cationic, anionic, and nonionic surfactants are used as organic dispersants, with anionic surfactants being preferred. Examples include sodium alkylbenzene sulfonate, sodium α-olefin sulfonate, sodium alkyl sulfonate, and sodium alkyl diphenyl ether disulfonate. Meanwhile, inorganic dispersants include tricalcium phosphate, hydroxyapatite, calcium carbonate fine particles, titanium oxide fine particles, and silica fine particles.

[0205] Of these, the inorganic dispersant tricalcium phosphate is preferred because it has very little adverse effect on the granulation properties and stability thereof, and further on the properties of the toner obtained.

[0206] The amount of dispersant added is determined depending on the particle size of the granulated product, and as the amount of dispersant added increases, the particle size decreases. Therefore, although the amount of dispersant added varies depending on the desired particle size, it is preferably used in the range of 0.1% by mass to 15.0% by mass of the resin composition.

[0207] Furthermore, when preparing particles of the resin composition in an aqueous medium, it is preferable to carry out the preparation under high-speed shearing, and examples of devices that can provide high-speed shearing include various high-speed dispersers and ultrasonic dispersers.

[0208] Desolvation process: In the solvent removal step, the organic solvent contained in the particles of the obtained resin composition is removed to produce toner particles. The removal of the organic solvent is preferably carried out while stirring.

[0209] Washing, drying and classification process: After the solvent removal step, a washing and drying step may be carried out in which the toner particles are washed multiple times with water or the like, and then filtered and dried. When a dispersant that dissolves under acidic conditions, such as tricalcium phosphate, is used as the dispersant, it is preferable to wash with hydrochloric acid or the like and then wash with water. By performing washing, the dispersant used for granulation can be removed. After washing, the toner particles can be obtained by filtering, drying, and appropriately classifying them.

[0210] [Suspension polymerization method] By the suspension polymerization method, toner particles are produced, for example, as follows.

[0211] A polymerizable monomer composition is prepared by uniformly dissolving or dispersing a polymerizable monomer that forms a binder resin, a colorant, a wax component, a polymerization initiator, etc., using a dispersing machine such as a homogenizer, a ball mill, an ultrasonic dispersing machine, etc. The polymerizable monomer composition is dispersed in an aqueous medium to granulate particles of the polymerizable monomer composition, and then the polymerizable monomer in the particles made of the polymerizable monomer composition is polymerized to obtain toner particles.

[0212] In this case, the polymerizable monomer composition is preferably one prepared by mixing a dispersion in which a colorant is dispersed in a first polymerizable monomer (or a part of the polymerizable monomer) with at least a second polymerizable monomer (or the remaining polymerizable monomer). That is, by first dispersing the colorant sufficiently in the first polymerizable monomer, and then mixing it with the second polymerizable monomer together with other toner materials, the colorant can be present in the polymer particles in a better dispersed state.

[0213] The obtained toner particles may be filtered, washed, dried and classified by known methods, if necessary.

[0214] <Process of adding external additives to toner particles> The toner particles obtained by the above-described method and an external additive are mixed in a mixer such as a Henschel mixer to obtain a toner.

[0215] The weight average particle diameter (D4) of the toner is preferably 4.0 μm or more and 15.0 μm or less, more preferably 4.0 μm or more and 9.0 μm or less, and even more preferably 6.0 μm or more and 8.0 μm or less.

[0216] The weight average particle size (D4) of the toner can be adjusted, for example, by classifying the toner particles.

[0217] The mixing ratio of the toner and the carrier is preferably 2% by mass or more and 15% by mass or less, more preferably 4% by mass or more and 13% by mass or less, in terms of the toner concentration in the two-component developer. When the toner concentration is 2% by mass or more, the image density becomes good, and when it is 15% by mass or less, fogging and scattering inside the machine can be suppressed.

[0218] [Methods for measuring various physical properties] The methods for measuring various physical properties are explained below.

[0219] <Separation of composite particles from toner> The physical properties can also be measured using composite particles separated from the toner by the following method.

[0220] Add 200 g of sucrose (Kishida Chemical) to 100 mL of ion-exchanged water and dissolve in a hot water bath to prepare a sucrose concentrate. Place 31 g of the sucrose concentrate and 6 mL of Contaminon N (a 10% by weight aqueous solution of a pH 7 neutral detergent for cleaning precision measuring instruments, consisting of a nonionic surfactant, an anionic surfactant, and an organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) in a centrifuge tube to prepare a dispersion. Add 1 g of toner to this dispersion and break up any clumps of toner with a spatula or similar.

[0221] The centrifuge tube is shaken in the shaker at 350 reciprocations per minute for 20 minutes. After shaking, the solution is transferred to a 50 mL glass tube for a swing rotor and centrifuged in a centrifuge at 3500 rpm for 30 minutes. After centrifugation, the toner is present in the top layer of the glass tube, and the fine particles are present in the aqueous solution below. The aqueous solution below is sampled and centrifuged to separate the sucrose and the fine particles, and the fine particles are collected. Centrifugation is repeated as necessary to thoroughly separate the particles, after which the dispersion is dried and the composite particles are collected.

[0222] When a plurality of external additives are added, the composite particles can be selected by using a centrifugal separation method or the like.

[0223] <Method for measuring the embedding rate of fine particle B> Composite microparticles were thoroughly dispersed in a visible light-curable resin (product name: Aronix LCR Series D-800; manufactured by Toagosei Co., Ltd.) and then cured by irradiation with short-wavelength light. The resulting cured product was cut using an ultramicrotome equipped with a diamond knife to prepare 250 nm thin flake samples. The cut samples were then magnified 40,000 to 50,000 times using a transmission electron microscope (JEOL JEM-2800) (TEM-EDX) to observe the cross section of the composite microparticles. The diameter of microparticle B and the depth of microparticle B embedded in microparticle A were measured from the cross-sectional image. Five particles of microparticle B were randomly selected for each composite microparticle, and the embedding ratio of microparticle B was calculated using the following formula. The number of external additive particles analyzed was 20 or more, and the average value was used to represent the embedding ratio of microparticle B. Burial rate of particle B (%) = (depth of particle B buried in particle A / diameter of particle B) x 100

[0224] <Solid 29 Method for measuring the content ratio of constituent compounds of fine particles A and composite particles using Si-NMR> solid 29 In Si-NMR, peaks are detected in different shift regions depending on the structure of the functional groups that bind to Si in the constituent compounds of the fine particle A and composite particles. By identifying the position of each peak using a standard sample, the structure that binds to Si can be identified. Furthermore, the abundance ratio of each constituent compound can be calculated from the obtained peak area. The ratio of the peak area of ​​the M unit structure, D unit structure (unit (c)), T unit structure (unit (b)), and Q unit structure (unit (a)) to the total peak area can be calculated.

[0225] solid 29 The specific conditions for Si-NMR measurement are as follows: Equipment: JNM-ECX5002 (JEOL RESONANCE) Temperature: room temperature Measurement method: DDMAS method 29 Si 45° Sample tube: zirconia 3.2 mm diameter Sample: Filled in powder form into a test tube Sample rotation speed: 10kHz Relaxation delay: 180s Scan:2000

[0226] When it is necessary to separate the fine particles B from the composite particles, the fine particles B can be separated, for example, as follows.

[0227] First, the composite particles are dispersed in a solution with a pH of 12 to 14. By carrying out a strong alkaline treatment, gaps are created at the interface between particle A and particle B, and then by centrifuging the mixture, particle B can be separated out using its specific gravity.

[0228] After the measurement, the peaks of the multiple silane components of the sample with different substituents and bonding groups are separated into M unit structures, D unit structures (c), T unit structures (b), and Q unit structures (a) by curve fitting, and the peak areas of each are calculated.

[0229] Curve fitting is performed using EXcalibur for Windows (registered trademark) version 4.2 (EX series), software for the JNM-EX400 manufactured by JEOL Ltd. Click "1D Pro" from the menu icon to load the measurement data. Next, select "Curve fitting function" from "Command" on the menu bar to perform curve fitting. Curve fitting is performed for each component so that the difference (composite peak difference) between the composite peak obtained by curve fitting and the peak of the measurement results is minimized.

[0230] Furthermore, by performing a separation process on the peaks corresponding to the structures represented by the above formulas (a), (b), and (c), the above-mentioned peaks PD1, PT1, PT2, PQ1, PQ2, and PQ3 are obtained. From each peak, the peak areas SD1, ST1, ST2, SQ1, SQ2, and SQ3 are calculated. If it is necessary to confirm the structure in more detail, 29 Along with the Si-NMR measurement results13 C-NMR and 1 The results of H-NMR measurements may also be used for identification.

[0231] <Method for measuring the adhesion rate of external additives> The method for measuring the adhesion rate of external additives is as follows. First, the amount of external additives contained in the toner before washing is quantified. The Si element intensity in the toner is measured using a wavelength dispersive X-ray fluorescence analyzer, Axios Advanced (manufactured by PANalytical). Next, the Si element intensity in the toner after washing is measured in the same way. The adhesion rate (%) can be calculated using the following formula. Adhesion rate (%) = (Si element strength in toner after water washing treatment / Si element strength in toner before water washing treatment) x 100

[0232] <Measurement of number average particle size of external additives> The number average particle diameter can be determined by observing toner particles with a scanning electron microscope (SEM) and measuring the number and particle diameter (maximum diameter) of the composite fine particles and fine particles C present on the surface of the toner particles. At this time, energy dispersive X-ray analysis (EDS) attached to the SEM can be used to confirm that the objects being measured are composite fine particles or fine particles C. The number average particle diameter is the average value measured for 100 toner particles.

[0233] <Method for measuring weight average particle size (D4) of toner> The weight-average particle size (D4) of the toner is measured with an effective number of 25,000 measurement channels using a precision particle size distribution measuring device equipped with a 100 μm aperture tube and using the narrow-pore electrical resistance method, the Coulter Counter Multisizer 3 (registered trademark, manufactured by Beckman Coulter, Inc.), and the accompanying dedicated software, the Beckman Coulter Multisizer 3 Version 3.51 (manufactured by Beckman Coulter, Inc.), for setting measurement conditions and analyzing measurement data, and the weight-average particle size (D4) is calculated by analyzing the measurement data.

[0234] The aqueous electrolyte solution used for the measurement is prepared by dissolving special grade sodium chloride in ion-exchanged water to a concentration of approximately 1% by mass, such as "ISOTON II" (manufactured by Beckman Coulter).

[0235] Before performing measurements and analysis, the dedicated software is set up as follows.

[0236] In the "Change Standard Measurement Method (SOM)" screen of the dedicated software, set the total count in control mode to 50,000 particles, the number of measurements to 1, and the Kd value obtained using "Standard Particles 10.0 μm" (Beckman Coulter). Press the threshold / noise level measurement button to automatically set the threshold and noise level. Also, set the current to 1600 μA, the gain to 2, the electrolyte to ISOTON II, and check "Flush aperture tube after measurement."

[0237] In the dedicated software's "Pulse to particle size conversion setting screen," set the bin interval to logarithmic particle size, the particle size bin to 256 particle size bins, and the particle size range to 2 μm or more and 60 μm or less.

[0238] The specific measurement method is as follows. (1) Pour approximately 200 ml of the electrolyte solution into a 250 ml round-bottom glass beaker made specifically for the Multisizer 3, set it on the sample stand, and stir the stirrer rod counterclockwise at 24 revolutions per second. Then, use the "aperture tube flush" function of the dedicated software to remove any dirt and air bubbles from inside the aperture tube. (2) Approximately 30 ml of the above-mentioned aqueous electrolyte solution is placed in a 100 ml flat-bottom glass beaker, and approximately 0.3 ml of a dilution obtained by diluting "Contaminon N" (a 10% by weight aqueous solution of a neutral detergent for cleaning precision measuring instruments, pH 7, consisting of a nonionic surfactant, anionic surfactant, and organic builder, manufactured by Wako Pure Chemical Industries, Ltd.) three times by weight with ion-exchanged water is added as a dispersant. (3) A predetermined amount of ion-exchanged water is placed in the water tank of an ultrasonic disperser, "Ultrasonic Dispersion System Tetora150" (manufactured by Nikkaki Bios Co., Ltd.), which has two built-in oscillators with an oscillation frequency of 50 kHz and a phase difference of 180 degrees and an electrical output of 120 W, and approximately 2 ml of the Contaminon N is added to this water tank. (4) Set the beaker (2) in the beaker fixing hole of the ultrasonic disperser, operate the ultrasonic disperser, and adjust the height of the beaker so that the resonance state of the liquid surface of the electrolytic solution in the beaker is maximized. (5) While the electrolyte solution in the beaker in (4) is irradiated with ultrasonic waves, approximately 10 mg of toner is added little by little to the electrolyte solution and dispersed. The ultrasonic dispersion process is then continued for another 60 seconds. During the ultrasonic dispersion, the water temperature in the water tank is appropriately adjusted to be between 10°C and 40°C. (6) The (5) electrolytic solution in which the toner has been dispersed is dropped using a pipette into the (1) round-bottom beaker placed in the sample stand, and the measurement concentration is adjusted to about 5%. Then, measurements are continued until the number of measured particles reaches 50,000. (7) The measurement data is analyzed using the dedicated software provided with the device, and the weight-average particle size (D4) is calculated. Note that when the dedicated software is set to Graph / Volume %, the "Average diameter" on the Analysis / Volume Statistics (Arithmetic Mean) screen is the weight-average particle size (D4).

[0239] <Measurement of ester group concentration> The ester group concentration in the present disclosure indicates the concentration of ester groups in the acrylic resin, and is defined by the following formula: [Ester group concentration (mmol / g)] = [Number of moles of ester groups in the acrylic moiety] / [Molecular weight of the acrylic moiety]

[0240] Acrylic resins are generally obtained by radical polymerization of (meth)acrylic acid esters with double bonds. Therefore, the number of moles of ester groups and molecular weight of the acrylic resin can be calculated from the number of moles and molecular weight of the (meth)acrylic acid ester used as the raw material.

[0241] To determine the ester group concentration from the coating resin of the present disclosure, first, place the magnetic carrier in a cup, and use toluene to elute the coating resin. Then, remove the magnetic carrier core and evaporate the eluted resin to separate the coating resin. The separated coating resin is analyzed by pyrolysis GC / MS to estimate the constituent monomers, and the ester group concentration is calculated from the results.

[0242] When two or more kinds of constituent monomers are used, the ester group concentration is calculated by calculating the molar ratio of the constituent monomers, for example, by 1H-NMR measurement using deuterated chloroform.

[0243] [Configurations included in embodiments of the invention] The disclosure of this embodiment includes the following configuration. (Configuration 1) A two-component developer containing a toner and a magnetic carrier, The magnetic carrier has a magnetic carrier core and a coating resin layer that coats the surface of the magnetic carrier core, the coating resin layer has at least one structure selected from the group consisting of a structure represented by the above formula (A), a structure represented by the above formula (B), and a structure represented by the above formula (C), The toner has composite particles on the surface of the toner particles, The composite particles are (i) fine particles A containing an organosilicon compound having a siloxane bond as a binder component; (ii) a particle B present in a state of being partially embedded on the surface of the particle A; and The composite particles have a number average particle size of primary particles of 0.03 μm or more and 0.30 μm or less, The solid of the fine particles A 29In the Si-NMR DD-MAS measurement, when the ratio of silicon atoms present in the state of the above unit (a) to all silicon atoms is Xa (%), the ratio of silicon atoms present in the state of the above unit (b) is Xb (%), and the ratio of silicon atoms present in the state of the above unit (c) is Xc (%), Xa, Xb, and Xc satisfy the following formulas (1) and (2): Xa + Xb + Xc ≥ 80% (1) Xb+Xc≧30% (2) In the composite particles, the average embedding rate of the fine particles B, as expressed by the following formula, is 30% or more and 90% or less, Burial rate of particle B (%) = (depth of particle B buried in particle A / diameter of particle B) x 100 The solid of the composite particle 29 In the Si-NMR DD-MAS measurement, the Si in the structure represented by the above formula (3) a and the peak PD1 corresponding to the silicon atom represented by the formula (4) above. b and the peak PT1 corresponding to the silicon atom represented by the formula (5) above. c and the peak PT2 corresponding to the silicon atom represented by the formula (6) above. d and the peak PQ1 corresponding to the silicon atom represented by the formula (7) above. e and the peak PQ2 corresponding to the silicon atom represented by the formula (8) above. f A peak PQ3 corresponding to a silicon atom represented by A two-component developer characterized in that the above formula (9) is satisfied when the area of ​​peak PD1 is SD1, the area of ​​peak PT1 is ST1, the area of ​​peak PT2 is ST2, the area of ​​peak PQ1 is SQ1, the area of ​​peak PQ2 is SQ2, the area of ​​peak PQ3 is SQ3, and the total peak area due to all silicon atoms is SSi. (Configuration 2) The two-component developer according to configuration 1, wherein SD1, ST1, ST2, SQ1, SQ2, SQ3, and SSi satisfy the above formula (10). (Configuration 3) The two-component developer according to configuration 1 or 2, wherein the coating resin layer has a structure represented by formula (A). (Configuration 4) The two-component developer according to any one of Configurations 1 to 3, wherein the coating resin layer has a structure represented by formula (A) and the ester group concentration of the coating resin layer is 5.0 mmol / g or more and 11.0 mmol / g or less. (Configuration 5) The two-component developer according to any one of Configurations 1 to 4, wherein the coating resin layer has a structure represented by formula (A) and is a copolymer of a monomer containing a (meth)acrylic acid ester monomer having an alicyclic hydrocarbon group or a (meth)acrylic acid monomer having an alkyl group having 1 to 8 carbon atoms. (Configuration 6) The two-component developer according to any one of Configurations 1 to 5, wherein the coating resin layer has a structure represented by the above formula (A), and when the value of the middle part of the formula (9) is α and the concentration of the ester group in the coating resin layer is β (mmol / g), the following formula (11) is satisfied: 16.0≦β / α≦100.0 (11) (Configuration 7) The two-component developer according to any one of configurations 1 to 6, wherein Xa, Xb, and Xc satisfy the following formulae (12), (13), and (14): 30%≦Xa / (Xa+Xb+Xc)≦80% (12) 0%≦Xb / (Xa+Xb+Xc)≦50% (13) 20%≦Xc / (Xa+Xb+Xc)≦70% (14) (Configuration 8) The two-component developer according to any one of Configurations 1 to 7, wherein the magnetic carrier contains 0.5 parts by mass or more and 3.5 parts by mass or less of the coating resin layer relative to 100 parts by mass of the magnetic carrier core particles. (Configuration 9) The two-component developer according to any one of Configurations 1 to 8, wherein the toner contains 0.1 parts by mass or more and 10.0 parts by mass or less of the composite particles per 100 parts by mass of the toner particles. (Configuration 10) The two-component developer according to any one of configurations 1 to 9, wherein the fine particles B are silica fine particles or alumina fine particles. (Configuration 11) The two-component developer according to any one of Configurations 1 to 10, wherein the adhesion rate of the composite particles to the toner particle surfaces is 50% or more and 90% or less. [Example]

[0244] The present disclosure will be described in more detail below with reference to examples, but the present disclosure is not limited to these examples. In the following formulations, parts are by weight unless otherwise specified.

[0245] <Production example of binder resin 1> Bisphenol A ethylene oxide (2.2 mole adduct): 50.0 mole parts Bisphenol A propylene oxide (2.2 mole adduct): 50.0 mole parts Terephthalic acid: 90.0 parts by mole Trimellitic anhydride: 10.0 parts by mole 100 parts of the monomers constituting the polyester unit were mixed together with 500 ppm of titanium tetrabutoxide in a 5-liter autoclave.

[0246] A reflux condenser, a water separator, an N2 gas inlet pipe, a thermometer, and a stirrer were attached to the autoclave, and a condensation polymerization reaction was carried out at 230°C while introducing N2 gas into the autoclave. The reaction time was adjusted to obtain the desired softening point, and after completion of the reaction, the resin was removed from the vessel, cooled, and pulverized to obtain Binder Resin 1. The softening point of Binder Resin 1 was 130°C, and the Tg was 57°C.

[0247] The softening point was measured as follows.

[0248] (Softening point measurement) The softening point is measured using a constant-load extrusion capillary rheometer, the "Flow Tester CFT-500D Flow Property Evaluation Device" (Shimadzu Corporation), according to the manual that comes with the device. With this device, a constant load is applied from above the sample by a piston, while the sample filled in the cylinder is heated and melted, and the molten sample is extruded from a die at the bottom of the cylinder, allowing a flow curve to be obtained that shows the relationship between the piston's descending distance and the temperature.

[0249] The softening point is the "melting temperature in the 1 / 2 method" described in the manual attached to the "flow property evaluation device, Flow Tester CFT-500D."

[0250] The melting temperature in the 1 / 2 method is calculated as follows.

[0251] First, calculate half the difference between the amount of piston descent Smax when the outflow ends and the amount of piston descent Smin when the outflow starts (this is called X; X = (Smax - Smin) / 2). Then, the temperature on the flow curve when the amount of piston descent on the flow curve is the sum of X and Smin is the melting temperature in the half method.

[0252] The measurement sample is a cylindrical sample of approximately 8 mm in diameter, compressed at 25°C for 60 seconds using a tablet press (e.g., NT-100H, manufactured by NPA Systems Co., Ltd.) with a weight of approximately 1.3 g. The measurement conditions for the CFT-500D are as follows: Test mode: Temperature rising method Starting temperature: 50℃ Achieved temperature: 200℃ Measurement interval: 1.0℃ Heating rate: 4.0℃ / min Piston cross-sectional area: 1.000cm 2 Test load (piston load): 10.0 kgf / cm 2 (0.9807MPa) Preheat time: 300 seconds Die hole diameter: 1.0mm Die length: 1.0mm

[0253] <Production example of composite particle 1> 1. Hydrolysis and condensation polymerization process: (1) 21.6 g of RO water, 135.0 g of methanol, 0.004 g of acetic acid as a catalyst, and 12.2 g of dimethyldimethoxysilane were charged into a 500 ml beaker and stirred at 45° C. for 5 minutes. (2) To this was added 2.0 g of 28% ammonia water, 15.0 g of tetraethoxysilane, and 5.0 g of colloidal silica aqueous dispersion A (silica solid content: 40 mass%, silica number average particle size: 40 nm (0.04 μm)), and the mixture was stirred at 30° C. for 3.0 hours to obtain a raw material solution.

[0254] 2.Particleization process: 120.0 g of RO water was placed in a 1000 ml beaker, and the raw material solution obtained in the hydrolysis and polycondensation steps was added dropwise over 5 minutes while stirring at 25° C. Thereafter, the mixture was heated to 60° C. and stirred for 1.5 hours while maintaining the temperature at 60° C. to obtain a dispersion of external additive fine particles.

[0255] 3. Hydrophobization process: To the dispersion of external additive fine particles obtained in the above-mentioned particulate formation step, 6.0 g of hexamethyldisilazane was added as a hydrophobizing agent, and the mixture was stirred at 60°C for 3.0 hours. After leaving the mixture to stand for 5 minutes, the powder that precipitated at the bottom of the solution was collected by suction filtration and dried under reduced pressure at 120°C for 24 hours to obtain Composite Particles 1. The number average particle size of the primary particles of Composite Particles 1 was 0.12 μm.

[0256] <Production example of composite particle 2> Composite particles 2 were obtained in the same manner as in the production example of composite particles 1, except that in the hydrolysis and polycondensation step (2), an alumina aqueous dispersion (alumina solid content: 30 mass %, alumina number average particle size: 40 nm (0.04 μm)) was used instead of colloidal silica aqueous dispersion A. The number average particle size of the primary particles of composite particles 2 was 0.12 μm.

[0257] <Production example of composite particle 3> Composite particles 3 were obtained in the same manner as in the production example of composite particles 1, except that in (2) of the hydrolysis and polycondensation step, 7.0 g of a titanium oxide aqueous dispersion (titanium oxide solid content: 30 mass %, titanium oxide number average particle size: 40 nm (0.04 μm)) was used instead of colloidal silica aqueous dispersion A. The number average particle size of the primary particles of composite particles 3 was 0.12 μm.

[0258] <Production example of composite particle 4> Composite particles 4 were obtained in the same manner as in the production example for composite particles 1, except that in (1) of the hydrolysis and polycondensation step, dimethyldimethoxysilane was changed to 5.4 g, and in (2) tetraethoxysilane was changed to 8.2 g, and 13.6 g of trimethoxymethylsilane was added. The number average particle size of the primary particles of composite particles 4 was 0.12 μm.

[0259] <Production Example of Composite Particle 5> Composite particle 5 was obtained in the same manner as in the production example of composite particle 1, except that in (1) of the above hydrolysis and polycondensation step, dimethyldimethoxysilane was not added, but 25.3 g of trimethoxymethylsilane was added, and in (2) the amount of tetraethoxysilane was changed to 1.9 g. The number average particle size of the primary particles of Composite Particle 5 was 0.12 μm.

[0260] <Production example of composite particle 6> Composite particles 6 were obtained in the same manner as in the production example of composite particles 1, except that in the hydrolysis and polycondensation step (2), the amount of 28% aqueous ammonia was changed to 1.0 g and the stirring temperature was changed to 25° C. The number average particle size of the primary particles of composite particles 6 was 0.12 μm.

[0261] <Production example of composite particle 7> Composite particles 7 were obtained in the same manner as in the production example of composite particles 1, except that in the hydrolysis and polycondensation step (2), the stirring temperature was changed to 35° C. The number average particle size of the primary particles of composite particles 7 was 0.12 μm.

[0262] <Production example of composite particle 8> Composite particles 8 were obtained in the same manner as in the production example of composite particles 1, except that in the hydrolysis and polycondensation step (2), the amount of 28% aqueous ammonia was changed to 3.0 g and the stirring temperature was changed to 35° C. The number average particle size of the primary particles of composite particles 8 was 0.12 μm.

[0263] <Production example of composite particle 9> Composite particles 9 were obtained in the same manner as in the production example of composite particles 1, except that in (2) of the hydrolysis and polycondensation step, colloidal silica aqueous dispersion B (silica solid content: 40 mass%, silica number average particle size: 10 nm (0.01 μm)) was used instead of colloidal silica aqueous dispersion A, the amount of 28% ammonia water was changed to 1.0 g, the stirring temperature was changed to 45°C, and the stirring time was changed to 4.5 hours. The number average particle size of the primary particles of composite particles 9 was 0.03 μm.

[0264] <Production Example of Composite Particle 10> Composite particles 10 were obtained in the same manner as in the production example of composite particles 1, except that in the hydrolysis and polycondensation step (2), the amount of 28% aqueous ammonia was changed to 3.0 g and the stirring temperature was changed to 25° C. The number average particle size of the primary particles of composite particles 10 was 0.30 μm.

[0265] <Production example of composite particle 12> Composite particles 10 were obtained in the same manner as in the production example of composite particles 1, except that in the hydrolysis and polycondensation step (2), the amount of 28% aqueous ammonia was changed to 0.5 g and the stirring temperature was changed to 25° C. The number average particle size of the primary particles of composite particles 10 was 0.12 μm.

[0266] <Production example of composite particle 13> 1. Hydrolysis and condensation polymerization process: (1) 21.6 g of RO water, 135.0 g of methanol, 0.004 g of acetic acid as a catalyst, and 12.2 g of dimethyldimethoxysilane were charged into a 500 ml beaker and stirred at 45° C. for 5 minutes. (2) To this was added 2.0 g of 28% aqueous ammonia and 15.0 g of tetraethoxysilane, and the mixture was stirred at 30° C. for 2.0 hours. (3) 5.0 g of colloidal silica aqueous dispersion A (silica solid content: 40 mass %, particle size: 40 nm) was added thereto and stirred for 10 minutes to obtain a raw material solution.

[0267] 2.Particleization process: 120.0 g of RO water was placed in a 1000 ml beaker, and the raw material solution obtained in step 1 above was added dropwise over 5 minutes while stirring at 25°C. The mixture was then heated to 60°C and stirred for 1.5 hours while maintaining the temperature at 60°C to obtain a dispersion of composite particles.

[0268] 3. Hydrophobization process: To the dispersion of external additive fine particles obtained in the above-mentioned 2. Particle formation step, 6.0 g of hexamethyldisilazane was added as a hydrophobizing agent, and the mixture was stirred at 60°C for 3.0 hours. After leaving the mixture to stand for 5 minutes, the powder that precipitated at the bottom of the solution was collected by suction filtration and dried under reduced pressure at 120°C for 24 hours to obtain composite particles 11. The number average particle size of the primary particles of composite particles 11 was 0.12 μm.

[0269] <Production example of composite particle 14> Composite particles 14 were obtained in the same manner as in the production example of composite particles 1, except that in (2) of the hydrolysis and polycondensation step, colloidal silica aqueous dispersion B (silica solid content: 40 mass%, silica number average particle size: 10 nm (0.01 μm)) was used instead of colloidal silica aqueous dispersion A, the amount of 28% ammonia water was changed to 1.0 g, the stirring temperature was changed to 45°C, and the stirring time was changed to 4.0 hours. The number average particle size of the primary particles of composite particles 14 was 0.02 μm.

[0270] <Production example of composite particle 15> Composite particles 15 were obtained in the same manner as in the production example of composite particles 1, except that in the hydrolysis and polycondensation step (2), the amount of 28% aqueous ammonia was changed to 5.0 g and the stirring temperature was changed to 25° C. The number average particle size of the primary particles of composite particles 15 was 0.33 μm.

[0271] <Production example of composite particle 11> A 250 mL four-neck round-bottom flask equipped with an overhead stirrer, condenser, and thermocouple was charged with 18.7 g of colloidal silica dispersion (40 wt. % silica solids, 30 nm (0.03 μm) silica number average particle size), 125 mL of DI water, and 16.5 g (0.066 mol) of methacryloxypropyl-trimethoxysilane. The temperature was increased to 65°C, and the mixture was stirred at 120 rpm. Nitrogen gas was bubbled through the mixture for 30 minutes. After 3 hours, 0.16 g of 2,2'-azobisisobutyronitrile radical initiator dissolved in 10 mL of ethanol was added, and the temperature was increased to 75°C.

[0272] The radical polymerization was allowed to proceed for 5 hours, after which 3 mL of 1,1,1,3,3,3-hexamethyldisilazane was added to the mixture. The reaction was allowed to proceed for an additional 3 hours. The final mixture was filtered through a 170-mesh sieve to remove coagulum, and the dispersion was dried in a Pyrex dish at 120°C overnight to yield Composite Particle 11. The number average particle size of the primary particles of the composite particles 11 was 0.12 μm.

[0273] The physical properties of the composite particles 1 to 15 and inorganic fine particles 1 obtained above are shown in Table 1. For the inorganic fine particles 1, colloidal silica having a number-average particle size of 0.10 μm was used.

[0274] [Table 1]

[0275] <Toner 1 manufacturing example> Binding resin 1 100 parts Paraffin wax (melting point 78°C) 4 parts CI Pigment Blue 15:3 4 parts The above materials were premixed in a Henschel mixer (product name: FM-10C, manufactured by Nippon Coke Co., Ltd.), and then melt-kneaded at 160°C using a twin-screw kneading extruder. The resulting kneaded mixture was cooled, coarsely pulverized using a hammer mill, and then finely pulverized using a turbo mill. The resulting finely pulverized product was classified using a multi-division classifier utilizing the Coanda effect, yielding toner base particles 1 with a weight average particle size (D4) of 6.5 μm.

[0276] Next, the obtained toner base particles 1 were subjected to external addition treatment as follows. Toner base particles 1: 100 parts ·Composite particles 1: 3.0 parts The above materials were mixed in a Henschel mixer (product name: FM-10C, manufactured by Nippon Coke Co., Ltd.) at a rotation speed of 67 s -1 (4000 rpm), a rotation time of 2 minutes, and an external addition temperature of room temperature were mixed, and then the mixture was passed through an ultrasonic vibration sieve with a mesh size of 54 μm to obtain Toner 1.

[0277] <Production example of toners 2 to 24> Toners 2 to 24 were obtained in the same manner as in the production example of Toner 1, except that the external addition conditions were changed so that the adhesion rate would be the value in Table 2, and the particle type and addition amount were changed as shown in Table 2.

[0278] [Table 2]

[0279] <Manufacturing example of magnetic carrier core 1> Process 1 (weighing and mixing process): Fe2O368.3% by mass MnCO328.5% by mass Mg(OH)22.0% by mass SrCO31.2% by mass The ferrite raw materials were weighed, and 80 parts of the ferrite raw materials were mixed with 20 parts of water, followed by wet mixing for 3 hours in a ball mill using zirconia with a diameter (φ) of 10 mm to prepare a slurry with a solid content of 80 mass%.

[0280] Step 2 (pre-firing step): The mixed slurry was dried using a spray dryer (manufactured by Okawahara Kakoki Co., Ltd.) and then fired in a batch electric furnace in a nitrogen atmosphere (oxygen concentration 1.0% by volume) at a temperature of 1050°C for 3.0 hours to produce calcined ferrite.

[0281] Step 3 (Crushing): The calcined ferrite was crushed to about 0.5 mm using a crusher, and water was then added to prepare a slurry. The solid content of the slurry was adjusted to 70% by mass. The slurry was crushed for 3 hours using a wet ball mill with 1 / 8-inch stainless steel beads to obtain a slurry. This slurry was further crushed for 4 hours using a wet bead mill with 1 mm diameter zirconia to obtain a calcined ferrite slurry with a volume-based 50% particle size (D50) of 1.3 μm.

[0282] Process 4 (granulation process): To 100 parts of the calcined ferrite slurry, 1.0 part of ammonium polycarboxylate as a dispersant and 1.5 parts of polyvinyl alcohol as a binder were added, and the mixture was granulated into spherical particles using a spray dryer (manufactured by Okawara Kakoki Co., Ltd.) and dried. The resulting granules were subjected to particle size adjustment and then heated at 700°C for 2 hours in a rotary electric furnace to remove organic substances such as the dispersant and binder.

[0283] Step 5 (baking): The material was fired in a nitrogen atmosphere (oxygen concentration 1.0% by volume) over a period of 2 hours from room temperature to the firing temperature (1100°C), and then held at 1100°C for 4 hours. The temperature was then lowered to 60°C over 8 hours, and the material was returned from the nitrogen atmosphere to the air and removed when the temperature was below 40°C.

[0284] Step 6 (sorting step): After crushing the agglomerated particles, they were sieved through a sieve with 150 μm openings to remove coarse particles, air classification to remove fine powder, and further magnetic separation to remove low magnetic force particles, thereby obtaining porous magnetic core particles 1.

[0285] 100 parts of porous magnetic core particles 1 were placed in the stirring vessel of a mixer / stirrer (NDMV type universal stirrer manufactured by Dalton), the temperature was maintained at 60°C, and 5 parts of a filling resin consisting of 95.0% by mass of methyl silicone oligomer and 5.0% by mass of γ-aminopropyltrimethoxysilane was added dropwise at normal pressure.

[0286] After the dropwise addition was completed, stirring was continued while adjusting the time, and the temperature was raised to 70°C, filling the resin composition into the particles of each porous magnetic core.

[0287] After cooling, the resin-filled magnetic core particles obtained were transferred to a mixer (a UD-AT drum mixer manufactured by Sugiyama Heavy Industries Co., Ltd.) equipped with a spiral blade in a rotatable mixing container, and the temperature was raised to 140°C at a rate of 2°C / min while stirring under a nitrogen atmosphere. Heating and stirring were then continued at 140°C for 50 minutes.

[0288] The resin-filled and hardened ferrite particles were then cooled to room temperature, and non-magnetic materials were removed using a magnetic separator. Coarse particles were then removed using a vibrating sieve to obtain resin-filled magnetic carrier cores 1.

[0289] <Manufacturing example of magnetic carrier core 2> The raw materials were weighed to a concentration of 35 mol% MnO, 14.5 mol% MgO, 50 mol% Fe2O3, and 0.5 mol% SrO, mixed with water, and milled for 5 hours in a wet media mill to obtain a slurry. The resulting slurry was dried in a spray dryer to obtain spherical particles. The mixture was pre-calcined at 950°C for 2 hours, then milled in a wet ball mill using 0.5 cm diameter stainless steel beads for 1 hour, and then further milled using 0.3 cm diameter zirconia beads for 4 hours. An appropriate amount of dispersant was added to the slurry, and polyvinyl alcohol resin (PVA) was added as a binder at 0.8% by mass based on the solid content to ensure the strength of the granulated particles. The mixture was then granulated and dried in a spray dryer and calcined in an electric furnace at 1275°C and an oxygen concentration of 2.5% by volume (nitrogen gas atmosphere) for 5 hours. Thereafter, the mixture was crushed and further classified to adjust the particle size, and then low magnetic force products were separated by magnetic separation to obtain magnetic carrier cores 2.

[0290] <Manufacturing example of magnetic carrier core 3> To 100.0 parts of magnetite powder (magnetite A) with a number-average particle size of 0.30 μm, 4.0 parts of a silane coupling agent (3-(2-aminoethylamino)propyltrimethoxysilane) was added, and the mixture was mixed and stirred at high speed in a container at 100°C or higher to treat the magnetite A.

[0291] Phenol 10 parts 6 parts formaldehyde solution (40% formaldehyde, 10% methanol, 50% water) Treated Magnetite A 84 parts The above materials, 5 parts of 28% aqueous ammonia, and 20 parts of water were placed in a flask, and the mixture was heated to 85°C over 30 minutes and maintained at that temperature while stirring and mixing. A polymerization reaction was carried out for 3 hours, and the resulting phenolic resin was cured. The cured phenolic resin was then cooled to 30°C, and more water was added. The supernatant was removed, and the precipitate was washed with water and air-dried. This was then dried at 60°C under reduced pressure (5 mmHg or less) to obtain spherical magnetic carrier cores 3 with the magnetic material dispersed therein.

[0292] <Magnetic Carrier 1 Manufacturing Example> Cyclohexyl methacrylate 75.8 parts Methyl methacrylate 5.4 parts Methyl methacrylate macromonomer 32.7 parts The above-described raw materials (109.0 parts in total) were added to a four-necked flask equipped with a reflux condenser, a thermometer, a nitrogen suction tube, and a rotary stirrer, and then 100.0 parts of toluene, 100.0 parts of methyl ethyl ketone, and 2.4 parts of azobisisovaleronitrile were added, and the mixture was maintained at 80°C under a nitrogen stream for 10 hours to obtain a coating resin.

[0293] 100 magnetic carrier cores 2 parts coating resin The above-mentioned amount of coating resin was diluted with toluene to a resin content of 5% for 100 parts of magnetic carrier cores, and the resulting solution was thoroughly stirred. Then, magnetic carrier cores 1 were placed in a planetary mixer (Nauta Mixer VN, manufactured by Hosokawa Micron Corporation) maintained at 60°C, and the above-mentioned resin solution was added. The resin solution was added by adding half of the amount, and the solvent was removed and applied for 30 minutes. Next, another half of the resin solution was added, and the solvent was removed and applied for 40 minutes.

[0294] The magnetic carrier coated with the resin coating layer was then transferred to a mixer (a UD-AT type drum mixer manufactured by Sugiyama Heavy Industries Co., Ltd.) equipped with spiral blades in a rotatable mixing container, and heat-treated for 2 hours at 120°C in a nitrogen atmosphere while stirring at 10 revolutions per minute. The obtained magnetic carrier was separated into low magnetic carriers by magnetic separation, passed through a sieve with 150 μm openings, and then classified with an air classifier to obtain magnetic carrier 1.

[0295] <Manufacturing Examples of Magnetic Carriers 2 to 17> Magnetic carriers 2 to 17 were obtained in the same manner as in Magnetic Carrier Production Example 1, except that the types and amounts of materials added were changed as shown in Table 3. The molar ratio of NMA to AA in the coating resin of Magnetic Carrier 13 was 9:1.

[0296] Furthermore, no coating resin was synthesized for magnetic carrier 15, and a commercially available silicone resin (SR2410, Toray Dow Corning Silicone Co., Ltd.) was used. For magnetic carrier 17, magnetic carrier core 3 was used as is without being coated with a coating resin.

[0297] [Table 3] CHMA: Cyclohexyl methacrylate MMA: methyl methacrylate 2-EHMA: 2-ethylhexyl methacrylate NMA: Nonyl methacrylate MA: methyl acrylate AA: acrylic acid St: styrene

[0298] <Two-component developers 1 to 41> Toners 1 to 24 and magnetic carriers 1 to 17 were shaken in a shaker (YS-8D model, manufactured by Yayoi Co., Ltd.) to a toner concentration of 8% by mass, and 300 g of each two-component developer was prepared. The vibration conditions of the shaker were 200 rpm and 2 minutes. Details of two-component developers 1 to 41 are shown in Table 4.

[0299] [Table 4]

[0300] [Examples 1 to 33 and Comparative Examples 1 to 8] The obtained two-component developer was subjected to the following evaluations.

[0301] A modified Canon imagePRESS C850 color copier was used as the image forming apparatus. Two-component developers were placed in each color developing unit, images were formed, and various evaluations were performed in a durability test.

[0302] For durability testing, a chart with FFH output at a specified image ratio was used under the following printing conditions: FFH is a value representing 256 gradations in hexadecimal, with 00h being the first gradation (white background) of the 256 gradations, and FFH being the 256th gradation (solid area) of the 256 gradations. (conditions) Image formation speed: A4 size, full color 100 sheets / min Development conditions: The development contrast was adjusted to any value, and the automatic correction by the main unit was disabled. The peak-to-peak voltage (Vpp) of the alternating electric field was adjusted to a frequency of 2.0 kHz, from 0.7 kV to 1.8 kV in 0.1 kV increments. Each color was modified so that a monochrome image could be output.

[0303] During the durability evaluation, the developing machine was modified so that the carrier of the two-component developer would not be replaced (auto-refresh mechanism).

[0304] The evaluation items are shown below.

[0305] (1)White spots For the durability test, 100,000 images were printed using a 5% image ratio FFH output chart under a printing environment of 23°C temperature / 5% RH (hereafter referred to as "N / L"). After the durability test, the image density was measured using an X-Rite color reflection densitometer (500 series: manufactured by X-Rite) and the development conditions were adjusted so that the solid (FFh) density on the paper was 1.4. The number of white spots was measured by printing 17 gradations (00h to FFh, each horizontal band 10mm x 290mm) on A4 size paper and counting the number of spots that occurred.

[0306] The evaluation paper was plain copy paper CS-814 (A4 size, basis weight 81.4 g / m 2 (sold by Canon Marketing Japan Inc.) was used. [Evaluation criteria] A: Number of white spots: 0 to less than 3 B: Number of white spots: 3 or more but less than 6 C: Number of white spots: 6 or more but less than 10 D: Number of white spots: 10 or more but less than 20 E: Number of white spots: 20 or more

[0307] (2) Evaluation of in-plane uniformity For the durability test, a FFH output chart with an image ratio of 30% was used in a printing environment of 30°C temperature / 80% RH (hereinafter referred to as "H / H"), and 100,000 images were output. After the durability test was completed, a screen halftone image with an average reflection density of 0.80 was output on A3 size paper, and the in-plane uniformity was evaluated.

[0308] The evaluation paper was plain copy paper CS-814 (A3 size, basis weight 81.4 g / m 2 (sold by Canon Marketing Japan Inc.) was used.

[0309] The image density was measured at 45 points on one sheet using a spectrodensitometer 500 series (X-Rite Corporation), and the standard deviation was evaluated according to the following evaluation criteria. [Evaluation criteria] A: Standard deviation: less than 0.020 B: Standard deviation: 0.020 or more and less than 0.040 C: Standard deviation: 0.040 or more and less than 0.060 D: Standard deviation: 0.060 or more and less than 0.080 E: Standard deviation: 0.080 or more

[0310] The results of the above evaluations are shown in Table 5. In each of the above evaluation items, if there were no items that received an E rating, the product was judged to be good.

[0311] [Table 5]

Claims

1. A two-component developer containing a toner and a magnetic carrier, The magnetic carrier has a magnetic carrier core and a coating resin layer that coats the surface of the magnetic carrier core, The coating resin layer has at least one structure selected from the group consisting of a structure represented by the following formula (A), a structure represented by the following formula (B), and a structure represented by the following formula (C), 【number】 (wherein X represents a carbon atom or a silicon atom. R a , R b each independently represents a hydrogen atom or an alkyl group having 1 to 10 carbon atoms. The toner has composite particles on the surface of the toner particles, The composite particles are (i) fine particles A containing an organosilicon compound having a siloxane bond as a binder component; (ii) fine particles B present on the surface of the fine particles A in a partially embedded state; and The composite particles have a number average particle size of primary particles of 0.03 μm or more and 0.30 μm or less, The solid of the fine particles A 29 In the DD-MAS measurement of Si-NMR, when the ratio of silicon atoms present in the state of the following unit (a) to all silicon atoms is Xa (%), the ratio of silicon atoms present in the state of the following unit (b) is Xb (%), and the ratio of silicon atoms present in the state of the following unit (c) is Xc (%), Xa, Xb, and Xc satisfy the following formulas (1) and (2): Xa+Xb+Xc≧80% (1) Xb+Xc≧30% (2) 【number】 (In the formula, R 1 , R 2 each independently represents an alkyl group having 1 to 6 carbon atoms. In the composite particle, the fine particles B have an average embedding rate represented by the following formula of 30% or more and 90% or less, Buried rate of particle B (%) = (depth of particle B buried in particle A / diameter of particle B) × 100 The solid of the composite particle 29 In the DD-MAS measurement of Si-NMR, Si in the structure represented by the following formula (3) a and a peak PD1 corresponding to a silicon atom represented by the following formula (4): b and a peak PT1 corresponding to a silicon atom represented by the following formula (5): c and a peak PT2 corresponding to a silicon atom represented by the following formula (6): d and a peak PQ1 corresponding to a silicon atom represented by the following formula (7): e and a peak PQ2 corresponding to a silicon atom represented by the following formula (8): f A peak PQ3 corresponding to a silicon atom represented by A two-component developer characterized in that, when the area of ​​peak PD1 is SD1, the area of ​​peak PT1 is ST1, the area of ​​peak PT2 is ST2, the area of ​​peak PQ1 is SQ1, the area of ​​peak PQ2 is SQ2, the area of ​​peak PQ3 is SQ3, and the total peak area due to all silicon atoms is SSi, the developer satisfies the following formula (9): 【number】 (In the formula, R 3 , R 4 each independently represents an alkyl group having 1 to 6 carbon atoms. [Equation 1]

2. The two-component developer according to claim 1 , wherein SD1, ST1, ST2, SQ1, SQ2, SQ3, and SSi satisfy the following formula (10): [Equation 2]

3. 3. The two-component developer according to claim 1, wherein the coating resin layer has a structure represented by formula (A).

4. 3. The two-component developer according to claim 1, wherein the coating resin layer has a structure represented by formula (A), and the coating resin layer has an ester group concentration of 5.0 mmol / g or more and 11.0 mmol / g or less.

5. 3. The two-component developer according to claim 1, wherein the coating resin layer has a structure represented by formula (A), and the coating resin layer is a copolymer of a monomer containing a (meth)acrylic acid ester monomer having an alicyclic hydrocarbon group or a (meth)acrylic acid monomer having an alkyl group having 1 to 8 carbon atoms.

6. 3. The two-component developer according to claim 1, wherein the coating resin layer has a structure represented by the above formula (A), and when the value of the middle part of the formula (9) is α and the concentration of the ester group in the coating resin layer is β (mmol / g), the following formula (11) is satisfied: １６．０≦β／α≦１００．０ （１１）

7. 3. The two-component developer according to claim 1, wherein Xa, Xb, and Xc satisfy the following formulae (12), (13), and (14). 30%≦Xa / (Xa+Xb+Xc)≦80% (12) 0%≦Xb / (Xa+Xb+Xc)≦50% (13) 20%≦Xc / (Xa+Xb+Xc)≦70% (14)

8. 3. The two-component developer according to claim 1, wherein the magnetic carrier contains the coating resin layer in an amount of 0.5 parts by mass or more and 3.5 parts by mass or less with respect to 100 parts by mass of the magnetic carrier core particles.

9. 3. The two-component developer according to claim 1, wherein the toner contains the composite particles in an amount of 0.1 parts by mass or more and 10.0 parts by mass or less with respect to 100 parts by mass of the toner particles.

10. 3. The two-component developer according to claim 1, wherein the fine particles B are silica fine particles or alumina fine particles.

11. 3. The two-component developer according to claim 1, wherein the composite particles have a fixing rate to the toner particle surface of 50% or more and 90% or less.

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