Toner, developer, toner storage unit, image forming apparatus, and image forming method

Abstract

To provide a toner that can improve transfer properties of the toner and can prevent generation of an abnormal image.SOLUTION: A toner includes a toner base particle having a resin particle containing at least a binder resin and wax and resin fine particles covering the surface of the resin particle, and an external additive. The coverage of the surface of the toner base particle by the resin fine particles is 30% or more and 70% or less. The number of coarse particles having a particle diameter of 20 μm or more is 10 or more and 200 or less in 1 g of the toner.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a toner, a developer, a toner storage unit, an image forming apparatus, and an image forming method. [Background technology]

[0002] In recent years, toners are required to have smaller particle size and high-temperature offset resistance for improving the quality of output images, low-temperature fixability for energy saving, and heat-resistant storage stability that can withstand high temperatures and high humidity during storage and transportation after production. In particular, since the power consumption during fixation accounts for a large portion of the power consumption in the image forming process, improving the low-temperature fixability is extremely important.

[0003] In order to improve the low-temperature fixing property of a toner, it is necessary to use a material with a low melting point in the toner. However, a toner produced using a material with a low melting point has poor heat-resistant storage stability, and there is a trade-off between low-temperature fixing property and heat-resistant storage stability.

[0004] In order to achieve both low-temperature fixability and heat-resistant storage stability, a method for producing composite resin particles has been proposed that includes a step of forming composite resin particles in which resin fine particles containing two types of resin as constituents in the same particle are attached to the surface of the resin particles, and then removing part or all of the resin from the resin fine particles (see, for example, Patent Documents 1 to 3). Patent Document 4 also proposes that resin fine particles be present on the surface of toner particles. Summary of the Invention [Problem to be solved by the invention]

[0005] However, there has been a demand for a technology that can simultaneously achieve high image quality by improving transferability and suppress the occurrence of abnormal images.

[0006] An object of the present invention is to provide a toner that can improve the transferability of the toner and can suppress the occurrence of abnormal images. [Means for solving the problem]

[0007] The toner of the present invention which solves the above problems has the composition described in (1) below. (1) A toner comprising toner base particles in which the surfaces of resin particles containing at least a binder resin and a wax are covered with resin fine particles, and an external additive, a coverage rate of the resin fine particles on the surface of the toner base particle is 30% or more and 70% or less, The number of coarse particles having a particle size of 20 μm or more per 1 g of the toner is 10 to 200. A toner characterized by: Effect of the Invention

[0008] According to the present invention, it is possible to provide a toner that can improve the transferability of the toner and also suppress the occurrence of abnormal images. [Brief description of the drawings]

[0009] [Figure 1] FIG. 1 is a schematic diagram showing an example of an image forming apparatus of the present invention. [Diagram 2] FIG. 2 is a schematic diagram showing another example of the image forming apparatus of the present invention. [Diagram 3] FIG. 3 is a partial enlarged view of the image forming apparatus of FIG. [Figure 4] FIG. 4 is a schematic diagram illustrating an example of a process cartridge. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] The toner of the present invention contains at least a binder resin and toner base particles in which the surfaces of resin particles containing wax are covered with resin fine particles, and an external additive. The coverage of the surface of the toner base particle with the resin fine particles is 30% or more and 70% or less, and the number of coarse particles having a particle size of 20 μm or more per gram of the toner mass is 10 to 200.

[0011] When the surface coverage of the toner base particles with the resin particles is 30% or more, the heat-resistant storage stability of the toner is improved and good transferability can be ensured. Also, when the coverage is 70% or less, external additives are easily attached and heat is easily transferred during toner fixing, ensuring transferability and fixability.

[0012] The present invention is characterized in that the number of coarse particles having a particle size of 20 μm or more is 10 to 200 per 1 g of the mass of the toner. If coarse particles are present in the toner, gaps may be formed around the particles during the transfer process, and spots that look like smudges may be formed on the image with the coarse particles as nuclei. By reducing the number of coarse particles, the occurrence of the above-mentioned abnormal images can be suppressed. In addition, the number of coarse particles is 10 to 200, and more preferably 10 to 100. If the number of coarse particles exceeds 200, abnormal images will occur. On the other hand, if the number of coarse particles is less than 10, poor cleaning will occur around the cleaning blade, and the toner particles will aggregate to form coarse particles, causing abnormal images.

[0013] In the present invention, it is preferable that the average interparticle distance of the resin fine particles on the surface of the toner base particle is 10 nm to 600 nm. By setting the interparticle distance (the straight line distance connecting the centers) of the resin fine particles adjacent to each other on the surface of the toner base particle to 10 nm to 600 nm, good storage stability and low-temperature fixability can be obtained, and a certain liberation rate can be obtained when inorganic fine particles such as silica and titanium are externally added to the surface of the toner base particle, thereby improving cleaning properties and transferability.

[0014] In the present invention, it is preferable that the liberation rate A (mass %) of silica in the toner is 0.3≦A≦2.0. In order to coat each unit in the system with the external additive, a certain amount of the external additive must be liberated from the toner. If the liberation rate A is less than 0.3, the external additive does not coat each unit, causing poor cleaning and resulting in abnormal images. On the other hand, if the liberation rate A is more than 2.0, the toner adheres to and aggregates with the liberated external additive to form coarse particles, resulting in abnormal images.

[0015] In the cleaning method using a cleaning blade in which a blade made of an elastic material is pressed against an image carrier to remove toner, and in the cleaning roller method in which a roller made of an elastic material is pressed against an image carrier and rotated to remove toner, there is a problem that poor image quality due to poor cleaning is likely to occur. In response to this problem, a developer in which zinc stearate is added to a toner together with silica has been proposed in the prior art. In an image forming apparatus using this developer, a coating of zinc stearate is formed on the surface of a photoconductor during development. This reduces the frictional force of the photoconductor surface, improving the sliding of the cleaning member on the surface of the photoconductor and improving background smearing and transferability. It is also expected to have the effect of preventing wear of the photoreceptor itself over time. Zinc stearate acts as a lubricant between the cleaning blade and the image carrier, which allows the toner to have good cleaning properties. However, because zinc stearate is easily attached to the toner base particles due to its shape, it may not be liberated in the system even if it is added to the toner, and the desired coating effect may not be achieved.

[0016] In contrast, in the present invention, the surfaces of the toner base particles are covered with resin fine particles, so that the resin fine particles do not impede fixing and can harden the toner base particles. As a result, it is possible to maintain low-temperature fixing properties while improving heat-resistant storage stability, transferability, and cleaning properties, and to suppress the occurrence of abnormal images.

[0017] In the present invention, the particle diameter of the resin fine particles is preferably in the range of 10 nm to 40 nm. By reducing the particle diameter of the particles present on the base surface, good transferability and cleanability can be maintained without impairing low-temperature fixability. In addition, by setting the coverage rate of the resin fine particles on the toner base particles to 30% to 70%, the adhesion strength when inorganic fine particles such as silica and titanium are externally added to the surface of the toner base particles can be made appropriate. As a result, a certain amount of the inorganic fine particles are liberated from the toner base particles during cleaning, and the liberated inorganic fine particles are deposited on the contact surface between the cleaning blade and the photoconductor, thereby obtaining good transferability and cleanability. In addition, the liberation rate of the inorganic fine particles can be suppressed to an appropriate amount, thereby suppressing the occurrence of abnormal images.

[0018] The present invention specifies the numerical values ​​of the coverage of the resin fine particles on the surface of the toner base particle, the number of coarse particles in the toner particle, the interparticle distance of the resin fine particles, and the liberation rate A (mass%) of the external additive as constituent elements of the invention. Therefore, the method for measuring these values ​​will be described below.

[0019] (Removal of external additives) In order to measure the coverage rate of the resin fine particles and the interparticle distance of the resin fine particles, the toner is first subjected to ultrasonic treatment to release and remove the external additives from the toner, and the toner is made into a state close to the toner base particles, and then the resin fine particles covering the toner base particles are observed using a scanning electron microscope (SEM). The method for releasing the external additive is as follows.

[0020] -How to separate external additives- [1] Add 50 mL of a 5% by weight aqueous solution containing a surfactant (product name: Noigen ET-165, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) to a 100 mL screw tube, add 3 g of toner to the mixture, and gently move it up and down and left and right. Then, mix it with a ball mill for 30 minutes so that the toner is mixed into the dispersion solution.

[0021] [2] Then, using an ultrasonic homogenizer (product name homogenizer, model VCX750, CV33, manufactured by SONICS & MATERIALS LLC), set the output to 40 W and apply ultrasonic energy for 60 minutes.

[0022] [Ultrasonic conditions] Vibration time: 60 minutes continuous ·Amplitude: 40W ·Vibration start temperature: 23±1.5℃ ·Temperature during vibration: 23±1.5℃

[0023] [3](1) The dispersion liquid is suction filtered using filter paper (product name: Qualitative Filter Paper (No. 2, 110 mm), manufactured by Advantec Toyo Co., Ltd.), washed twice again with ion-exchanged water, filtered, and the liberated additives are removed, and the toner particles are then dried. (2) The toner obtained in (1) is observed with a scanning electron microscope (SEM). First, external additives and fillers containing Si are detected by observing the backscattered electron image. (3) The image of (1) is binarized using image processing software (ImageJ) to remove the external additives and fillers.

[0024] Next, a secondary electron image is observed at the same position as in (2). Since resin fine particles cannot be observed in a reflected electron image, but can only be observed in a secondary electron image, the image is compared with the image obtained in (3), and the fine particles present in the areas other than the remaining external additives and filler (areas other than those removed in (3)) are regarded as resin fine particles and observed.

[0025] [Shooting conditions] Scanning electron microscope: SU-8230 (Hitachi High-Technologies Corporation) Magnification: 35,000x Image capture: SE(L): Secondary electrons, BSE (backscattered electrons) Acceleration voltage: 2.0kV ·Acceleration current: 1.0μA ·Probe current:Normal Focus mode: UHR WD:8.0mm

[0026] (Measurement of the coverage rate of toner base particles with resin particles) The area ratio of the resin fine particles to the area of ​​the toner base particles is calculated using the image processing software. This measurement was carried out for 100 binarized images (one toner particle per image), and the average value of the area ratio of each particle was taken as the coverage rate.

[0027] (Measurement of interparticle distance of resin fine particles) The interparticle distance (the distance between the centers of the particles) of the resin fine particles is measured using the image software. This measurement was carried out for 100 binarized images (one toner particle per image), and the average value was taken as the average value of the distance between the resin particles. The distance between the resin fine particles was calculated by the following formula, where the interparticle distance is x.

number

[0028] (Measurement of silica liberation rate A (mass%)) In the present invention, the liberation rate of silica is defined as a value obtained according to the measurement method described below. The liberation rate A (mass %) of silica from the toner was measured by the following procedure. In a 500 mL beaker, 10 g of polyoxyalkylene alkyl ether (Noigen ET-165, Daiichi Kogyo Seiyaku Co., Ltd.) and 300 mL of pure water were placed, and dispersed by ultrasonication for 1 hour to obtain Dispersion A. Dispersion A was then transferred to a 2 L measuring flask, diluted with the solution, and dissolved by ultrasonication for 1 hour to obtain Dispersion B containing 0.5% polyoxyalkylene alkyl ether.

[0029] 50 mL of dispersion B was poured into a 110 mL screw tube, and 3.75 g of sample toner was added. Dispersion C was obtained by stirring for 30 to 90 minutes until the screw tube was absorbed into dispersion B. At this time, the rotation was kept as low as possible to prevent bubbles from being generated. After the toner was sufficiently dispersed, the vibration part of an ultrasonic homogenizer (VCX750, manufactured by SONICS & Materials, Inc., 20 kHz, 750 watts) was inserted 2.5 cm into dispersion C, and ultrasonic vibration was applied for 1 minute at 40% output energy to produce dispersion D.

[0030] Dispersion D was placed in a 50 mL centrifuge tube and centrifuged at 2,000 rpm for 2 minutes to obtain a supernatant and a precipitate. The precipitate was poured into a separatory funnel while being washed with 60 mL of pure water, and the washing water was removed by suction filtration. The precipitate after filtration was placed back into the mini cup, 60 mL of pure water was poured into the mini cup, and the mixture was stirred five times with the handle of the spatula. The washing water was removed again by suction filtration, and the toner remaining on the filter paper was collected and dried in a 40°C thermostatic chamber for 8 hours.

[0031] After drying, 3 g of the obtained toner was molded into pellets with a diameter of 3 mm and a thickness of 2 mm using an automatic pressure molding machine (T-BRB-32, manufactured by Maekawa; load 6.0 t, pressure time 60 seconds), and treated to obtain sample toner. The initial sample toner that had not been subjected to the above treatment was similarly molded into pellets having a diameter of 3 mm and a thickness of 2 mm to prepare pre-treatment sample toner.

[0032] The amount of silica in the pelletized sample toner was measured by quantitative analysis using a fluorescent X-ray analyzer (ZSX-100e, manufactured by Rigaku Corporation). The calibration curve used was created in advance using sample toners with silica contents of 0.1 parts by mass, 1 part by mass, and 1.8 parts by mass per 100 parts by mass of toner. The silica liberation rate (mass%) was calculated by the following formula. Silica liberation rate A (mass%)=[Silica content of sample toner before treatment (parts)−Silica content of sample toner after treatment (parts)] / sample toner before treatment (parts)×100

[0033] (Measurement of the number of coarse toner particles) In the present invention, "the number of coarse particles having a particle size of 20 μm or more" refers to a value determined as follows. Weigh out 1 g of toner, place it on a metal mesh (Tokyo Screen Co., Ltd.) with 20 μm openings, and suck in the toner particles at a wind speed of 10 m / s. After that, observe the coarse particles remaining on the mesh surface with a microscope (Keyence Co., Ltd.) and count the number.

[0034] The components constituting the toner, the carrier, a method for producing the toner, an image forming apparatus, an image forming method, and the like will be described below. <Toner> -Toner base particles- The toner base particles contain at least a binder resin and a wax, and may further contain other components as required. The toner base particles are preferably obtained by dissolving or dispersing at least a binder resin and a wax in an organic solvent, adding the obtained solution or dispersion to an aqueous phase, and removing the organic solvent from the obtained dispersion.More preferably, the toner base particles are obtained by dissolving or dispersing at least a binder resin precursor and a colorant in an organic solvent, adding the obtained solution or dispersion to an aqueous phase to crosslink or elongate the binder resin precursor, and removing the organic solvent.

[0035] The toner generally contains a polyester as a binder resin, preferably a non-linear non-crystalline polyester, and more preferably a crystalline polyester. The THF-insoluble component usually preferably contains a non-linear non-crystalline polyester or a crystalline polyester.

[0036] The non-crystalline polyester is obtained by using a polyhydric alcohol component and a polycarboxylic acid component such as a polycarboxylic acid, a polycarboxylic acid anhydride, or a polycarboxylic acid ester. In the present invention, the non-crystalline polyester resin refers to a resin obtained by using a polyhydric alcohol component and a polycarboxylic acid component such as a polycarboxylic acid, a polycarboxylic anhydride, or a polycarboxylic acid ester, as described above. Modified polyester resins, for example, prepolymers described below, and resins obtained by subjecting the prepolymers to a crosslinking and / or elongation reaction, do not belong to the non-crystalline polyester resin.

[0037] Examples of the polyhydric alcohol component include alkylene (carbon number 2-3) oxide (average number of added moles 1-10) adducts of bisphenol A such as polyoxypropylene (2.2)-2,2-bis(4-hydroxyphenyl)propane and polyoxyethylene (2.2)-2,2-bis(4-hydroxyphenyl)propane; ethylene glycol, propylene glycol, neopentyl glycol, glycerin, pentaerythritol, trimethylolpropane, hydrogenated bisphenol A, sorbitol, or alkylene (carbon number 2-3) oxide (average number of added moles 1-10) adducts thereof. These may be used alone or in combination of two or more.

[0038] Examples of the polyvalent carboxylic acid component include dicarboxylic acids such as adipic acid, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, and maleic acid; succinic acids substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms such as dodecenylsuccinic acid and octylsuccinic acid; trimellitic acid, pyromellitic acid; anhydrides of these acids, and alkyl (carbon number 1 to 8) esters of these acids. These may be used alone or in combination of two or more.

[0039] It is preferable that the amorphous polyester resin, the prepolymer described below, and the resin obtained by crosslinking and / or elongation reaction of this prepolymer are at least partially compatible with each other. By being compatible with each other, low-temperature fixability and high-temperature offset resistance can be improved. For this reason, it is preferable that the polyhydric alcohol component and polyvalent carboxylic acid component constituting the amorphous polyester resin and the polyhydric alcohol component and polyvalent carboxylic acid component constituting the prepolymer described below have similar compositions.

[0040] The molecular weight of the non-crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose. However, if the molecular weight is too low, the toner may be inferior in heat-resistant storage stability and durability against stress such as stirring in a developing device, whereas if the molecular weight is too high, the toner may have high viscoelasticity when melted and may have inferior low-temperature fixing properties. Therefore, it is preferable that the weight average molecular weight (Mw) is 2,500 to 10,000, the number average molecular weight (Mn) is 1,000 to 4,000, and the Mw / Mn is 1.0 to 4.0, as measured by GPC.

[0041] The acid value of the non-crystalline polyester resin is not particularly limited and can be appropriately selected according to the purpose, but is preferably 1 mgKOH / g or more and 50 mgKOH / g or less, and more preferably 5 mgKOH / g or more and 30 mgKOH / g or less. When the acid value is 1 mgKOH / g or more, the toner is easily negatively charged, and further, when fixed to paper, the affinity between the paper and the toner is improved, and low-temperature fixability can be improved. When the acid value is 50 mgKOH / g or less, charging stability, particularly charging stability against environmental changes, is not reduced.

[0042] The hydroxyl value of the non-crystalline polyester resin is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 5 mgKOH / g or more.

[0043] The glass transition temperature (Tg) of the non-crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose. However, if the Tg is too low, the toner may have poor heat-resistant storage stability and poor durability against stress such as stirring in a developing device, whereas if the Tg is too high, the toner may have high viscoelasticity when melted and poor low-temperature fixability. Therefore, the glass transition temperature is preferably 40°C to 70°C, and more preferably 45°C to 60°C.

[0044] The content of the non-crystalline polyester resin is not particularly limited and can be appropriately selected according to the purpose, but is preferably 50 parts by mass or more and 95 parts by mass or less, more preferably 60 parts by mass or more and 90 parts by mass or less, relative to 100 parts by mass of the toner. If the content is less than 50 parts by mass, the dispersibility of the pigment and release agent in the toner may deteriorate, and image fogging and disturbance may easily occur, and if it exceeds 95 parts by mass, the content of the crystalline polyester may be reduced, resulting in poor low-temperature fixability. If the content is within the above-mentioned more preferred range, it is advantageous in that high image quality, high stability, and low-temperature fixability are all excellent.

[0045] The molecular structure of the amorphous polyester resin can be confirmed by NMR measurement of a solution or solid, as well as X-ray diffraction, GC / MS, LC / MS, IR measurement, etc. -1 and 990±10cm -1 One method is to detect a resin that does not have absorption due to olefin δCH (out-of-plane bending vibration) as a non-crystalline polyester resin.

[0046] -Resin fine particles- The volume average primary particle diameter of the resin fine particles is preferably 5 nm to 100 nm, more preferably 10 nm to 100 nm, and even more preferably 10 nm to 50 nm. When the volume average primary particle diameter satisfies the above range, low temperature fixability is improved.

[0047] The volume average primary particle size can be measured, for example, by observing images taken with a scanning electron microscope (SEM).

[0048] The resin fine particles (hereinafter, may be referred to as "resin fine particles (B)") preferably have a core resin (core portion) and a shell resin (outer shell portion) that covers at least a part of the surface of the core resin, more preferably consist of a core resin and a shell resin, and further preferably contain a vinyl-based unit consisting of a resin (b1) and a resin (b2).

[0049] The shell resin (hereinafter also referred to as "resin (b1)") and the core resin (hereinafter also referred to as "resin (b2)") are preferably polymers obtained by homopolymerizing or copolymerizing vinyl monomers.

[0050] Examples of the vinyl monomer include the following (1) to (10). (1) Vinyl hydrocarbons Examples of vinyl hydrocarbons include (1-1) aliphatic vinyl hydrocarbons, (1-2) alicyclic vinyl hydrocarbons, and (1-3) aromatic vinyl hydrocarbons. (1-1) Aliphatic vinyl hydrocarbons Aliphatic vinyl hydrocarbons include, for example, alkenes and alkadienes. Examples of the alkenes include ethylene, propylene, and α-olefins. Examples of the alkadienes include butadiene, isoprene, 1,4-pentadiene, 1,6-hexadiene, and 1,7-octadiene. (1-2) Alicyclic vinyl hydrocarbons Alicyclic vinyl hydrocarbons include mono- or di-cycloalkenes and alkadienes, and specific examples include (di)cyclopentadiene, terpene, and the like. (1-3) Aromatic vinyl hydrocarbons Examples of aromatic vinyl hydrocarbons include styrene and its hydrocarbyl (alkyl, cycloalkyl, aralkyl and / or alkenyl) substituted derivatives, and specific examples thereof include α-methylstyrene, 2,4-dimethylstyrene and vinylnaphthalene.

[0051] (2) Carboxyl-containing vinyl monomers and their salts Examples of the carboxyl group-containing vinyl monomer and its salt include unsaturated monocarboxylic acids (salts) having 3 to 30 carbon atoms, unsaturated dicarboxylic acids (salts), and anhydrides (salts) thereof, and monoalkyl (carbon number 1 to 24) esters thereof or salts thereof. Specific examples thereof include carboxyl group-containing vinyl monomers such as (meth)acrylic acid, (anhydride) maleic acid, maleic acid monoalkyl esters, fumaric acid, fumaric acid monoalkyl esters, crotonic acid, itaconic acid, itaconic acid monoalkyl esters, itaconic acid glycol monoether, citraconic acid, citraconic acid monoalkyl esters, and cinnamic acid, and metal salts thereof.

[0052] In the present invention, "(salt)" means an acid or a salt thereof. For example, an unsaturated monocarboxylic acid (salt) having 3 to 30 carbon atoms means an unsaturated monocarboxylic acid or a salt thereof. In the present invention, "(meth)acrylic" means methacrylic acid or acrylic acid. In the present invention, "(meth)acryloyl" means methacryloyl or acryloyl. In the present invention, "(meth)acrylate" means methacrylate or acrylate.

[0053] (3) Sulfonic acid group-containing vinyl monomers, vinyl sulfate monoesters, and their salts Examples of the sulfonic acid group-containing vinyl monomer, vinyl sulfate monoester, and salts thereof include alkene sulfonic acids (salts) having 2 to 14 carbon atoms, alkyl sulfonic acids (salts) having 2 to 24 carbon atoms, sulfo(hydroxy)alkyl-(meth)acrylates (salts), (meth)acrylamides (salts), and alkylarylsulfosuccinic acids (salts). Specifically, an example of an alkene sulfonic acid having 2 to 14 carbon atoms is vinyl sulfonic acid (salt), an example of an alkyl sulfonic acid (salt) having 2 to 24 carbon atoms is α-methylstyrene sulfonic acid (salt), and an example of a sulfo(hydroxy)alkyl-(meth)acrylate (salt) or (meth)acrylamide (salt) is sulfopropyl(meth)acrylate (salt), sulfuric acid ester (salt), or a sulfonic acid group-containing vinyl monomer (salt).

[0054] (4) Phosphate-containing vinyl monomers and their salts Examples of the phosphoric acid group-containing vinyl monomer and its salt include (meth)acryloyloxyalkyl (carbon number 1 to 24) phosphoric acid monoester (salt), (meth)acryloyloxyalkyl (carbon number 1 to 24) phosphonic acid (salt), and the like. Specific examples of the (meth)acryloyloxyalkyl (carbon number 1 to 24) phosphate monoester (salt) include 2-hydroxyethyl (meth)acryloyl phosphate (salt), phenyl-2-acryloyloxyethyl phosphate (salt), and the like. Specific examples of the (meth)acryloyloxyalkyl (carbon number: 1 to 24)phosphonic acid (salt) include 2-acryloyloxyethylphosphonic acid (salt).

[0055] Examples of the salts of (2) to (4) above include alkali metal salts (sodium salts, potassium salts, etc.), alkaline earth metal salts (calcium salts, magnesium salts, etc.), ammonium salts, amine salts, and quaternary ammonium salts.

[0056] (5) Hydroxyl-containing vinyl monomers Examples of the hydroxyl group-containing vinyl monomer include hydroxystyrene, N-methylol (meth)acrylamide, hydroxyethyl (meth)acrylate, hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, (meth)allyl alcohol, crotyl alcohol, isocrotyl alcohol, 1-buten-3-ol, 2-buten-1-ol, 2-butene-1,4-diol, propargyl alcohol, 2-hydroxyethyl propenyl ether, and sucrose allyl ether.

[0057] (6) Nitrogen-containing vinyl monomers Examples of the nitrogen-containing vinyl monomer include (6-1) amino group-containing vinyl monomers, (6-2) amide group-containing vinyl monomers, (6-3) nitrile group-containing vinyl monomers, (6-4) quaternary ammonium cation group-containing vinyl monomers, and (6-5) nitro group-containing vinyl monomers. (6-1) Examples of amino group-containing vinyl monomers include aminoethyl (meth)acrylate. (6-2) Examples of amide group-containing vinyl monomers include (meth)acrylamide and N-methyl(meth)acrylamide. (6-3) Examples of nitrile group-containing vinyl monomers include (meth)acrylonitrile, cyanostyrene, and cyanoacrylate. (6-4) Examples of the vinyl monomer containing a quaternary ammonium cation group include quaternized products of tertiary amine group-containing vinyl monomers such as dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylamide, diethylaminoethyl (meth)acrylamide, and diallylamine (which are quaternized with a quaternizing agent such as methyl chloride, dimethyl sulfate, benzyl chloride, or dimethyl carbonate). (6-5) Examples of nitro group-containing vinyl monomers include nitrostyrene.

[0058] (7) Epoxy group-containing vinyl monomer Examples of the epoxy group-containing vinyl monomer include glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and p-vinylphenyl phenyl oxide.

[0059] (8) Halogen-containing vinyl monomers Examples of the halogen-containing vinyl monomer include vinyl chloride, vinyl bromide, vinylidene chloride, allyl chloride, chlorostyrene, bromostyrene, dichlorostyrene, chloromethylstyrene, tetrafluorostyrene, and chloroprene.

[0060] (9) Vinyl esters, vinyl (thio)ethers, vinyl ketones Examples of vinyl esters include vinyl acetate, vinyl butyrate, vinyl propionate, vinyl butyrate, diallyl phthalate, diallyl adipate, isopropenyl acetate, vinyl methacrylate, methyl 4-vinyl benzoate, cyclohexyl methacrylate, benzyl methacrylate, phenyl (meth)acrylate, vinyl methoxyacetate, vinyl benzoate, ethyl α-ethoxyacrylate, alkyl (meth)acrylates having an alkyl group having 1 to 50 carbon atoms [methyl (meth)acrylate], ) acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, dodecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate, eicosyl (meth)acrylate, behenyl (meth)acrylate, etc.)], dialkyl fumarate (wherein the two alkyl groups are linear, branched or alicyclic groups having 2 to 8 carbon atoms), dialkyl Examples of the poly(meth)allyloxyalkane include maleates (the two alkyl groups are straight-chain, branched-chain or alicyclic groups having 2 to 8 carbon atoms), poly(meth)allyloxyalkanes (diallyloxyethane, triallyloxyethane, tetraallyloxyethane, tetraallyloxypropane, tetraallyloxybutane, tetramethallyloxyethane, etc.), vinyl monomers having polyalkylene glycol chains (polyethylene glycol (molecular weight 300) mono(meth)acrylate, polypropylene glycol (molecular weight 500) monoacrylate, methyl alcohol ethylene oxide 10 mol adduct (meth)acrylate, lauryl alcohol ethylene oxide 30 mol adduct (meth)acrylate, etc.), poly(meth)acrylates (poly(meth)acrylates of polyhydric alcohols: ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, polyethylene glycol di(meth)acrylate, etc.). An example of the vinyl (thio)ether is vinyl methyl ether. An example of the vinyl ketone is vinyl methyl ketone.

[0061] (10) Other vinyl monomers Examples of other vinyl monomers include tetrafluoroethylene, fluoroacrylate, isocyanatoethyl (meth)acrylate, and m-isopropenyl-α,α-dimethylbenzyl isocyanate.

[0062] In the synthesis of the resin (b1), the vinyl monomers (1) to (10) may be used alone or in combination of two or more. As the resin (b1), from the viewpoint of low-temperature fixability, a styrene-(meth)acrylic acid ester copolymer and a (meth)acrylic acid ester copolymer are preferred, and a styrene-(meth)acrylic acid ester copolymer is more preferred. When the resin (b1) has a carboxylic acid, an acid value is imparted to the resin, and the resin fine particles (B) are easily attached to the surface of the toner particles to form the toner particles.

[0063] The vinyl monomer used in the resin (b2) may be the same as that used in the resin (b1). In synthesizing the resin (b2), the vinyl monomers (1) to (10) listed in the above resin (b1) may be used alone or in combination of two or more. As the resin (b2), from the viewpoint of low-temperature fixability, a styrene-(meth)acrylic acid ester copolymer and a (meth)acrylic acid ester copolymer are preferred, and a styrene-(meth)acrylic acid ester copolymer is more preferred.

[0064] In particular, it is preferable that the shell and core contain a styrene-acrylic resin. In this case, both heat-resistant storage stability and fixability can be achieved. As for the content of the resin in the shell and the content of the resin in the shell, it is preferable that the shell and core each contain 50% by mass or more of styrene-acrylic resin.

[0065] The loss modulus G" of the viscoelastic properties of the resin (b1) at 100° C. and a frequency of 1 Hz is preferably 1.5 MPa to 100 MPa, more preferably 1.7 MPa to 30 MPa, and even more preferably 2.0 MPa to 10 MPa. The loss modulus G" of the viscoelastic properties of the resin (b2) at 100° C. and a frequency of 1 Hz is preferably 0.01 MPa to 1.0 MPa, more preferably 0.02 MPa to 0.5 MPa, and even more preferably 0.05 MPa to 0.3 MPa. When the loss modulus G″ of the viscoelastic properties is within this range, it is easy to form toner particles in which the resin fine particles (B) containing the resin (b1) and the resin (b2) as constituent components in the same particle are adhered to the surface of the toner particle.

[0066] The loss modulus G″ of the viscoelastic properties of resins (b1) and (b2) at a frequency of 1 Hz and 100°C can be adjusted by changing the types and composition ratio of the constituent monomers or by adjusting the polymerization conditions (types and amounts of initiator and chain transfer agent, reaction temperature, etc.). Specifically, for example, by using the following composition, it is possible to adjust each G'' to be within the above-mentioned range.

[0067] (1) Regarding the glass transition temperature (Tg1) calculated from the constituent monomers of resin (b1) and the glass transition temperature (Tg2) calculated from the constituent monomers of resin (b2), Tg1 is preferably 0°C to 150°C, more preferably 50°C to 100°C, and Tg2 is preferably -30°C to 100°C, more preferably 0°C to 80°C, and most preferably 30°C to 60°C.

[0068] The glass transition temperature (Tg) calculated from the constituent monomers is a value that can be calculated by the Fox method. Here, the Fox method [TGFox, Phys. Rev., 86, 652 (1952)] is a method for estimating the Tg of a copolymer from the Tg of each homopolymer represented by the following formula. 1 / Tg=W1 / Tg1+W2 / Tg2++Wn / Tgn [In the formula, Tg is the glass transition temperature (expressed in absolute temperature) of the copolymer, Tg1, Tg2...Tgn are the glass transition temperatures (expressed in absolute temperature) of the homopolymers of each monomer component, and W1, W2...Wn are the weight fractions of each monomer component.]

[0069] (2) Regarding the calculated acid value (AV1) of the resin (b1) and the calculated acid value (AV2) of the resin (b2), (AV1) is preferably 75 mgKOH / g to 400 mgKOH / g, more preferably 150 mgKOH / g to 300 mgKOH / g, and (AV2) is 0 mgKOH / g to 50 mgKOH / g, more preferably 0 mgKOH / g to 20 mgKOH / g, and most preferably 0 mgKOH / g. The calculated acid value is a theoretical acid value calculated from the molar amount of acidic groups contained in the constituent monomers and the total mass of the constituent monomers.

[0070] As for the resin (b1), an example of a constituent monomer that satisfies the conditions (1) and (2) is a resin that contains, based on the total mass of the resin (b1), preferably 10% by mass to 80% by mass, and more preferably 30% by mass to 60% by mass of styrene, and preferably a total of 10% by mass to 60% by mass, and more preferably a total of 30% by mass to 50% by mass of methacrylic acid and / or acrylic acid.

[0071] Furthermore, the resin (b2) may, for example, be a resin containing, as constituent monomers, preferably 10% by mass to 100% by mass, and more preferably 30% by mass to 90% by mass of styrene, and preferably 0% by mass to 7.5% by mass in total, and more preferably 0% by mass to 2.5% by mass of methacrylic acid and / or acrylic acid, based on the total mass of the resin (b2).

[0072] (3) Adjust the polymerization conditions (types and amounts of initiator and chain transfer agent, reaction temperature, etc.). Specifically, regarding the number average molecular weights (Mn1) and (Mn2) of the resin (b1) and the resin (b2), (Mn1) is preferably 2,000 to 2,000,000, and more preferably 20,000 to 200,000. (Mn2) is preferably 1,000 to 1,000,000, and more preferably 10,000 to 100,000.

[0073] The loss modulus G″ of the viscoelastic properties in the present invention is measured, for example, using the following viscoelasticity measuring device. Equipment: ARES-24A (Rheometrics) Fixture: 25mm parallel plate Frequency: 1Hz Distortion rate: 10% Heating rate: 5℃ / min

[0074] The acid value (AVb1) of the resin (b1) is preferably from 75 mgKOH / g to 400 mgKOH / g, and more preferably from 150 mgKOH / g to 300 mgKOH / g. When the acid value is within the above range, the resin fine particles (B) containing vinyl units in which the resin (b1) and the resin (b2) are contained as constituents in the same particle are easily formed into particles adhered to the surface of the toner. Resin (b1) having an acid value within the above range is a resin that contains methacrylic acid and / or acrylic acid in a total amount of preferably 10% by mass to 60% by mass, and more preferably 30% by mass to 50% by mass, based on the total mass of resin (b1).

[0075] From the viewpoint of low-temperature fixability, the acid value (AVb2) of the resin (b2) is preferably from 0 mgKOH / g to 50 mgKOH / g, more preferably from 0 mgKOH / g to 20 mgKOH / g, and even more preferably 0 mgKOH / g. Resin (b2) having an acid value within this range is a resin that contains methacrylic acid and / or acrylic acid in a total amount of preferably 0% to 7.5% by mass, and more preferably 0% to 2.5% by mass, based on the total mass of resin (b2). The acid value can be measured, for example, by the method of JIS K0070:1992.

[0076] In the present invention, the glass transition temperature TgA of the shell portion (resin b1) is higher than the glass temperature TgB of the core portion (resin b2). By having the glass transition temperature TgA of the shell portion higher than the glass temperature TgB of the core portion, high heat-resistant storage stability can be ensured.

[0077] In order to make the glass transition temperature TgA of the shell portion of the resin microparticles higher than the glass transition temperature TgB of the core portion, for example, a method of adjusting the type and ratio of monomers used in synthesizing the shell can be mentioned.

[0078] The glass transition temperature TgA of the shell portion of the resin fine particles and the glass transition temperature TgB of the core portion preferably satisfy TgA-TgB≧10[° C.], and more preferably satisfy TgA-TgB≧20[° C.]. By making the difference between TgA and TgB 10° C. or more, the ease of forming toner particles in which the resin fine particles (B) are adhered to the toner surface and the low-temperature fixability of the toner particles of the present invention are excellent in balance.

[0079] In order to set the difference in glass transition temperature within the above range, for example, a method of adjusting the type and ratio of monomers used when synthesizing the shell portion and the core portion can be mentioned.

[0080] In the present invention, Tg is measured by the method (DSC) specified in ASTM D3418-82 using "DSC60-A" [manufactured by Shimadzu Corporation]. The method for measuring the glass transition temperature TgA of the shell portion and the glass transition temperature TgB of the core portion of the resin fine particles from the toner is as follows. For example, the shell is removed by using an organic solvent or by heating to separate only the core, which is then measured by the method (DSC) specified in the above-mentioned ASTM D3418-82.

[0081] The glass transition temperature TgA of the resin (b1) is preferably 0° C. to 150° C., and more preferably 50° C. to 100° C. When the glass transition temperature TgA is 0° C. or higher, the heat-resistant storage stability can be improved, and when it is 150° C. or lower, the inhibition of low-temperature fixability can be reduced.

[0082] The glass transition temperature TgB of the resin (b2) is preferably −30° C. to 100° C., more preferably 0° C. to 80° C., and even more preferably 30° C. to 60° C. When the glass transition temperature TgB is −30° C. or higher, the heat-resistant storage stability can be improved, and when it is 100° C. or lower, the inhibition of low-temperature fixability can be reduced.

[0083] The glass transition temperature Tg of the resin particles is preferably 40° C. or more and 70° C. or less. In this case, high heat-resistant storage stability can be ensured without inhibiting fixation. In order to set the glass transition temperature Tg of the resin particles in the above range, for example, a method of appropriately adjusting the glass transition temperatures of the shell portion and the core portion can be mentioned.

[0084] The glass transition temperature Tg of the resin particles from the toner is measured as follows: The resin particles on the toner surface are physically peeled off, or separated using an organic solvent and the solvent is removed, and then the glass transition temperature Tg is calculated by the above-mentioned measurement method.

[0085] From the viewpoint of ease of forming toner particles, the solubility parameter (hereinafter sometimes abbreviated as SP value) of the resin (b1) is set to 9 (cal / cm 3 ) 1 / 2 ~13(cal / cm 3 ) 1 / 2 is preferable, and 9.5 (cal / cm 3)1 / 2 ~12.5(cal / cm 3 ) 1 / 2 More preferably, 10.5 (cal / cm 3 ) 1 / 2 ~11.5(cal / cm 3 ) 1 / 2 is more preferred.

[0086] The SP value of the resin (b1) can be adjusted by changing the types and composition ratio of the constituent monomers. From the viewpoint of ease of forming toner particles, the SP value of the resin (b2) is set to 8.5 (cal / cm 3 ) 1 / 2 ~12.5(cal / cm 3 ) 1 / 2 is preferable, and 9 (cal / cm 3 ) 1 / 2 ~12(cal / cm 3 ) 1 / 2 More preferably, 10 (cal / cm3)1 / 2 to 11 (cal / cm 3 ) 1 / 2 is more preferred. The SP value of the resin (b2) can be adjusted by changing the types and composition ratio of the constituent monomers.

[0087] The SP value in the present invention is calculated by the method by Fedors [Polym. Eng. Sci. 14(2)152, (1974)].

[0088] From the viewpoint of TgA of resin (b1) and copolymerizability with other monomers, resin (b1) preferably contains 10% by mass to 80% by mass, and more preferably 30% by mass to 60% by mass of styrene as a constituent monomer, based on the total mass of resin (b1). From the viewpoint of TgB of resin (b2) and copolymerizability with other vinyl monomers, resin (b2) preferably contains 10% by mass to 100% by mass, and more preferably 30% by mass to 90% by mass of styrene as a constituent monomer, based on the total mass of resin (b2).

[0089] The number average molecular weight (Mn) of the resin (b1) is preferably 2,000 to 2,000,000, and more preferably 20,000 to 200,000. When Mn is 2,000 or more, the heat-resistant storage stability of the toner is improved, and when it is 2,000,000 or less, the low-temperature fixability of the toner is less hindered.

[0090] The weight average molecular weight (Mw) of the resin (b1) is preferably larger than that of the resin (b2), more preferably 1.5 times or more larger than that of the resin (b2), and even more preferably 2.0 times or more larger than that of the resin (b2). Within this range, the balance between the ease of forming toner particles and low-temperature fixability is excellent.

[0091] The weight average molecular weight (Mw) of the resin (b1) is preferably 20,000 to 20,000,000, and more preferably 200,000 to 2,000,000. When Mw is 20,000 or more, the heat-resistant storage stability of the toner is improved, and when it is 20,000,000 or less, there is little inhibition of low-temperature fixability.

[0092] The number average molecular weight (Mn) of the resin (b2) is preferably 1,000 to 1,000,000, and more preferably 10,000 to 100,000. When Mn is 1,000 or more, the heat-resistant storage stability of the toner is improved, and when it is 1,000,000 or less, the low-temperature fixability of the toner is less hindered.

[0093] The weight average molecular weight (Mw) of the resin (b2) is preferably 10,000 to 10,000,000, and more preferably 100,000 to 1,000,000. When Mw is 10,000 or more, the heat-resistant storage stability of the toner is improved, and when it is 10,000,000 or less, the low-temperature fixability of the toner is less hindered.

[0094] Among these, it is preferred that the Mw of resin (b1) is 200,000 to 2,000,000, the Mw of resin (b2) is 100,000 to 500,000, and the "Mw of (b1)" is greater than the "Mw of (b2)".

[0095] In the present invention, Mn and Mw can be measured by gel permeation chromatography (GPC) under the following conditions. Equipment (example): "HLC-8120" [manufactured by Tosoh Corporation] Column (example): "TSK GEL GMH6" [Tosoh Corporation] x 2 ·Measurement temperature: 40℃ Sample solution: 0.25% by mass tetrahydrofuran solution (undissolved matter was removed using a glass filter) ·Solution injection volume: 100μL Detector: Refractive index detector Reference material: 12 standard polystyrenes (TSKstandard POLYSTYRENE) (molecular weight: 500, 1,050, 2,800, 5,970, 9,100, 18,100, 37,900, 96,400, 190,000, 355,000, 1,090,000, 2,890,000) [manufactured by Tosoh Corporation]

[0096] The mass ratio of resin (b1) to resin (b2) in the resin fine particles (B) is preferably 5 / 95 to 95 / 5, more preferably 25 / 75 to 75 / 25, and even more preferably 40 / 60 to 60 / 40. When the mass ratio of resin (b1) to resin (b2) is 5 / 95 or more, the toner has excellent heat-resistant storage stability, and when the mass ratio of resin (b1) to resin (b2) is 95 / 5 or less, toner particles in which resin fine particles (B) adhere to the surfaces of the toner particles are easily formed.

[0097] Methods for producing the resin fine particles (B) include known production methods, such as the following production methods (I) to (V). (I) A method of seed polymerization of constituent monomers of resin (b2) using fine particles of resin (b1) in an aqueous dispersion as seeds. (II) A method of carrying out seed polymerization of constituent monomers of resin (b1) using fine particles of resin (b2) in an aqueous dispersion as seeds. (III) A method in which a mixture of resin (b1) and resin (b2) is emulsified in an aqueous medium to obtain an aqueous dispersion of resin fine particles. (IV) A method in which a mixture of resin (b1) and constituent monomers of resin (b2) is emulsified in an aqueous medium, and then the constituent monomers of resin (b2) are polymerized to obtain an aqueous dispersion of resin fine particles. (V) A method in which a mixture of resin (b2) and constituent monomers of resin (b1) is emulsified in an aqueous medium, and then the constituent monomers of resin (b1) are polymerized to obtain an aqueous dispersion of resin fine particles.

[0098] The fact that the resin microparticles (B) contain the shell resin (b1) and the core resin (b2) as constituent components within the same particle can be confirmed by observing an element mapping image of a cut surface of the resin microparticles (B) using a known surface elemental analysis device (TOF-SIMSEDX-SEM, etc.), and by observing an electron microscope image of a cut surface of the resin microparticles (B) stained with a stain corresponding to the functional groups contained in the resins (b1) and (b2).

[0099] Furthermore, the resin microparticles obtained by this method may be obtained as a mixture containing resin microparticles whose only constituent resin component is resin (b1) and resin microparticles whose only constituent resin component is resin (b2), in addition to resin microparticles (B) containing resin (b1) and resin (b2) as constituent components within the same particle. In the composite process described below, the mixture may be used as is, or only the resin microparticles (B) may be isolated and used.

[0100] Specific examples of (I) include a method in which the constituent monomers of (b1) are polymerized by dropwise polymerization to produce an aqueous dispersion of resin microparticles containing (b1), and then the constituent monomers of (b2) are polymerized using this as a seed; and a method in which (b1) produced in advance by solution polymerization or the like is emulsified and dispersed in water, and then the constituent monomers of (b2) are polymerized using this as a seed.

[0101] Specific examples of (II) include a method in which the constituent monomer of (b2) is polymerized by dropwise polymerization to produce an aqueous dispersion of resin microparticles containing (b2), and then the constituent monomer of (b1) is polymerized using this as a seed; and a method in which (b2) produced in advance by solution polymerization or the like is emulsified and dispersed in water, and then the constituent monomer of (b1) is polymerized using this as a seed.

[0102] A specific example of (III) is a method in which solutions or melts of (b1) and (b2) previously prepared by solution polymerization or the like are mixed together, and the mixture is then emulsified and dispersed in an aqueous medium.

[0103] Specific examples of (IV) include a method in which (b1), which has been produced in advance by solution polymerization or the like, is mixed with constituent monomers of (b2), the mixture is emulsified and dispersed in an aqueous medium, and then the constituent monomers of (b2) are polymerized; and a method in which (b1) is produced in the constituent monomers of (b2), the mixture is emulsified and dispersed in an aqueous medium, and then the constituent monomers of (b2) are polymerized.

[0104] Specific examples of (V) include a method in which (b2), which has been produced in advance by solution polymerization or the like, is mixed with the constituent monomers of (b1), the mixture is emulsified and dispersed in an aqueous medium, and then the constituent monomers of (b1) are polymerized; and a method in which (ab2) is produced in the constituent monomers of (b1), the mixture is emulsified and dispersed in an aqueous medium, and then the constituent monomers of (b1) are polymerized.

[0105] In the present invention, any of the above production methods (I) to (V) is suitable.

[0106] The resin fine particles (B) are preferably used in the form of an aqueous dispersion. The substance (aqueous medium) used in the aqueous dispersion is not particularly limited as long as it dissolves in water, and can be appropriately selected depending on the purpose, and examples thereof include a surfactant (D), a buffering agent, a protective colloid, etc. These may be used alone or in combination of two or more.

[0107] <Crystalline polyester resin> The crystalline polyester resin has structural units derived from a saturated aliphatic diol. As the saturated aliphatic diol, it is preferable to use an alcohol component containing a straight-chain aliphatic diol having 2 to 8 carbon atoms. This enables the crystalline polyester resin to be uniformly and finely dispersed within the toner, prevents filming of the crystalline polyester resin, improves stress resistance, and achieves low-temperature fixability of the toner.

[0108] The crystalline polyester resin has high crystallinity and exhibits a thermal melting characteristic in which the viscosity drops sharply near the fixing start temperature. By using the crystalline polyester resin having such characteristics in the toner, the toner has good heat-resistant storage stability due to the crystallinity until just before the melting start temperature, and at the melting start temperature, the toner has a good heat-resistant storage stability and low-temperature fixing property because the toner has a sharp viscosity drop (sharp melt property) and is fixed. In addition, the toner also shows good results in terms of the release width (the difference between the minimum fixing temperature and the hot offset occurrence temperature).

[0109] The crystalline polyester resin is obtained by using a polyhydric alcohol component and a polycarboxylic acid component such as a polycarboxylic acid, a polycarboxylic anhydride, or a polycarboxylic ester. In the present invention, the crystalline polyester resin refers to a resin obtained by using a polyhydric alcohol component and a polycarboxylic acid component such as a polycarboxylic acid, a polycarboxylic anhydride, or a polycarboxylic acid ester, as described above. Modified crystalline polyester resins, such as the prepolymers described below, and resins obtained by subjecting the prepolymers to a crosslinking and / or elongation reaction, do not belong to the crystalline polyester resins.

[0110] -Polyhydric alcohol component- The polyhydric alcohol component is not particularly limited and can be appropriately selected depending on the purpose. Examples of the polyhydric alcohol component include diols and trihydric or higher alcohols. Examples of the diol include saturated aliphatic diols. Examples of the saturated aliphatic diols include linear saturated aliphatic diols and branched saturated aliphatic diols. Among these, linear saturated aliphatic diols are preferred, and linear saturated aliphatic diols having 2 to 8 carbon atoms are more preferred. If the saturated aliphatic diol is branched, the crystallinity of the crystalline polyester resin may decrease, and the melting point may decrease. If the carbon number of the main chain is less than 2, the melting temperature may increase when polycondensing with an aromatic dicarboxylic acid, making low-temperature fixing difficult. On the other hand, if the carbon number exceeds 8, it is difficult to obtain a practical material. It is more preferred that the carbon number is 8 or less.

[0111] Examples of the saturated aliphatic diol include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, 1,14-eicosanedecanediol, etc. Among these, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol are preferred in terms of the high crystallinity of the crystalline polyester resin and excellent sharp melt properties. Examples of the trihydric or higher alcohol include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. These may be used alone or in combination of two or more.

[0112] -Polycarboxylic acid component- As the polyvalent carboxylic acid component, sebacic acid is used, but other divalent carboxylic acids and trivalent or higher carboxylic acids can be used in combination depending on the purpose. Examples of the divalent carboxylic acid include saturated aliphatic dicarboxylic acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, and 1,18-octadecanedicarboxylic acid; and aromatic dicarboxylic acids such as dibasic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, and mesaconic acid; and further, anhydrides and lower alkyl esters of these.

[0113] Examples of the trivalent or higher carboxylic acid include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, as well as anhydrides and lower alkyl esters of these. The polyvalent carboxylic acid component may contain a dicarboxylic acid component having a sulfonic acid group in addition to the saturated aliphatic dicarboxylic acid and aromatic dicarboxylic acid, and may contain a dicarboxylic acid component having a double bond in addition to the saturated aliphatic dicarboxylic acid and aromatic dicarboxylic acid. These may be used alone or in combination of two or more.

[0114] The melting point of the crystalline polyester resin is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 60° C. or more and less than 80° C. If the melting point is less than 60° C., the crystalline polyester resin is likely to melt at low temperatures, and the heat-resistant storage stability of the toner may decrease, whereas if the melting point is 80° C. or more, the polyester resin A may not melt sufficiently due to heating during fixing, and the low-temperature fixability may decrease. The melting point can be measured from the endothermic peak value on a differential scanning calorimeter (DSC) chart in DSC measurement.

[0115] The molecular weight of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose. However, from the viewpoint that a resin having a sharp molecular weight distribution and a low molecular weight has excellent low-temperature fixability, and that a large amount of low-molecular-weight components deteriorates heat-resistant storage stability, it is preferable that the ortho-dichlorobenzene-soluble portion of the crystalline polyester resin has a weight average molecular weight (Mw) of 3,000 to 30,000, a number average molecular weight (Mn) of 1,000 to 10,000, and Mw / Mn of 1.0 to 10, as measured by GPC.

[0116] The acid value of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but from the viewpoint of affinity between paper and resin, in order to achieve the desired low-temperature fixability, it is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, while in order to improve high-temperature offset resistance, it is preferably 45 mgKOH / g or less.

[0117] The hydroxyl value of the crystalline polyester resin is not particularly limited and may be appropriately selected depending on the purpose. In order to achieve the desired temperature fixing property and good charging characteristics, the hydroxyl value is preferably 0 mgKOH / g to 50 mgKOH / g, and more preferably 5 mgKOH / g to 50 mgKOH / g.

[0118] The molecular structure of the crystalline polyester resin can be confirmed by NMR measurement of a solution or solid, as well as X-ray diffraction, GC / MS, LC / MS, IR measurement, etc. A simple method includes a method of detecting a crystalline polyester resin as one having an absorption due to δCH (out-of-plane bending vibration) of olefin at 965±10 cm-1 or 990±10 cm-1 in an infrared absorption spectrum.

[0119] The content of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 2 to 20 parts by mass, more preferably 5 to 15 parts by mass, relative to 100 parts by mass of the toner. If the content is less than 2 parts by mass, the sharp melting by the crystalline polyester resin is insufficient, so that the low-temperature fixing property may be poor, and if it exceeds 20 parts by mass, the heat-resistant storage stability may be deteriorated and the image may be easily fogged. If the content is within the above more preferred range, it is advantageous in that high image quality, high stability, and low-temperature fixing property are all excellent.

[0120] <Inorganic filler> The toner base particles of the present invention are produced by adding an inorganic filler to the above-mentioned toner base particles. The inorganic filler is not particularly limited, and one or more types selected from calcium carbonate, kaolin clay, talc, barium sulfate, etc. can be added alone or in combination. These inorganic fillers may be surface-treated with a silane coupling agent, a surfactant, a metal soap, etc., and may be adjusted to a desired particle size distribution by classification, etc.

[0121] In addition to the above, the inorganic filler contained in the toner of the present invention is preferably a layered inorganic mineral, and more preferably a layered inorganic mineral modified with an organic ion. Layered inorganic minerals are inorganic minerals that are made up of layers several nanometers thick stacked on top of each other, and modifying them with organic ions means introducing organic ions into the ions that exist between the layers.

[0122] Known examples of layered inorganic minerals include smectites (montmorillonite, saponite, etc.), kaolins (kaolinite, etc.), magadiite, and kanemite. Modified layered inorganic minerals have high hydrophilicity due to their modified layered structure. Therefore, if the layered inorganic minerals are used in a toner that is dispersed in an aqueous medium and granulated without being modified, the layered inorganic minerals migrate into the aqueous medium and the toner cannot be deformed, but the modification increases hydrophilicity, and such modified layered inorganic minerals are finely divided and deformed during the production of the toner, and are present in particularly large amounts on the surface of the toner particles, and can be uniformly dispersed and arranged throughout the toner base particles, fulfilling a charge adjustment function and contributing to low-temperature fixation. In this case, the content of the modified layered inorganic minerals in the toner material is preferably 0.2 to 1.5% by mass.

[0123] The modified layered inorganic mineral used in the present invention is preferably one that has a basic smectite crystal structure and is modified with an organic cation. In addition, metal anions can be introduced by replacing a part of the divalent metal of the layered inorganic mineral with a trivalent metal. However, since the introduction of metal anions results in high hydrophilicity, it is preferable to use a layered inorganic compound in which at least a part of the metal anion is modified with an organic anion.

[0124] The organic ion modifier for the layered inorganic mineral in which at least a part of the ions of the layered inorganic mineral is modified with an organic ion may be a quaternary alkyl ammonium salt, a phosphonium salt, an imidazolium salt, etc., but a quaternary alkyl ammonium salt is preferable. The quaternary alkyl ammonium may be trimethylstearyl ammonium, dimethylstearylbenzyl ammonium, dimethyloctadecyl ammonium, oleylbis(2-hydroxyethyl)methyl ammonium, etc.

[0125] The organic ion modifier further includes sulfates, sulfonates, carboxylates, or phosphates having branched, unbranched, or cyclic alkyl (C1-C44), alkenyl (C1-C22), alkoxy (C8-C32), hydroxyalkyl (C2-C22), ethylene oxide, propylene oxide, etc. Carboxylic acids having an ethylene oxide skeleton are preferred.

[0126] By modifying at least a portion of the layered inorganic mineral with an organic ion, the layered inorganic mineral has a suitable hydrophobicity, the oil phase containing the toner composition and / or the toner composition precursor has a non-Newtonian viscosity, and the toner can be deformed. In this case, the content of the layered inorganic mineral partially modified with an organic ion in the toner material is preferably 0.2 to 1.5% by mass.

[0127] The layered inorganic mineral partially modified with organic ions can be appropriately selected, and examples thereof include montmorillonite, bentonite, hectorite, attapulgite, sepiolite, and mixtures thereof. Among these, montmorillonite or bentonite containing Al element is preferred because Al element is effective in improving charging ability.

[0128] Examples of commercially available layered inorganic minerals partially modified with organic cations include quaternium-18 bentonites such as Bentone 3, Bentone 38, Bentone 38V (manufactured by Rheox), Thixogel VP (manufactured by United Catalyst), Clayton 34, Clayton 40, and Clayton XL (manufactured by Southern Clay); stearalkonium bentonites such as Bentone 27 (manufactured by Rheox), Thixogel LG (manufactured by United Catalyst), Clayton AF, and Clayton APA (manufactured by Southern Clay); and quaternium-18 / benzalkonium bentonites such as Clayton HT and Clayton PS (manufactured by Southern Clay). Particularly preferred are Clayton AF and Clayton APA. Particularly preferred examples of layered inorganic minerals partially modified with organic anions include DHT-4A (manufactured by Kyowa Chemical Industry Co., Ltd.) modified with an organic anion represented by the following general formula (3). An example of the following general formula (3) is Hitenol 330T (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). R 1 (OR 2 ) n OSO 3 M...General formula (3) [In formula (3), R 1 is an alkyl group having 13 carbon atoms, R 2 represents an alkylene group having 2 to 6 carbon atoms, n represents an integer of 2 to 10, and M represents a monovalent metal element.

[0129] <Other ingredients> The other components are not particularly limited and can be appropriately selected depending on the purpose. Examples of the other components include a separator, a colorant, a polymer having a site capable of reacting with an active hydrogen group-containing compound, an active hydrogen group-containing compound, a charge control agent, an external additive, a flowability improver, a cleaning property improver, and a magnetic material.

[0130] <Release agent> The release agent is not particularly limited and can be appropriately selected from known agents. Examples of waxes and wax release agents include natural waxes such as vegetable waxes such as carnauba wax, cotton wax, wood wax, and rice wax; animal waxes such as beeswax and lanolin; mineral waxes such as ozokerite and cerusine; and petroleum waxes such as paraffin, microcrystalline, and petrolatum.

[0131] In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax, polyethylene, and polypropylene; synthetic waxes such as esters, ketones, and ethers; and the like can also be used. Further, fatty acid amide compounds such as 12-hydroxystearic acid amide, stearic acid amide, phthalimide anhydride, and chlorinated hydrocarbons; homopolymers or copolymers of polyacrylates such as poly-n-stearyl methacrylate and poly-n-lauryl methacrylate, which are low molecular weight crystalline polymer resins (for example, copolymers of n-stearyl acrylate and ethyl methacrylate); and crystalline polymers having long alkyl groups in their side chains may be used. Among these, hydrocarbon waxes such as paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyethylene wax, and polypropylene wax are preferred.

[0132] The melting point of the release agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 60° C. or higher and lower than 95° C.

[0133] The release agent is more preferably a hydrocarbon wax having a melting point of 60° C. or more and less than 95° C. Such a release agent can effectively act as a release agent between the fixing roller and the toner interface, and therefore can improve high-temperature offset resistance without applying a release agent such as oil to the fixing roller. In particular, hydrocarbon waxes are preferred because they have almost no compatibility with the polyester resin A and can function independently of each other, and therefore do not impair the softening effect of the crystalline polyester resin as a binder resin or the offset property of the release agent. If the melting point of the release agent is less than 60° C., the release agent is likely to melt at low temperatures, and the heat-resistant storage stability of the toner may be poor.If the melting point of the release agent is more than 95° C., the release agent may not melt sufficiently due to heating during fixing, and sufficient offset properties may not be obtained.

[0134] The content of the release agent is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 2 to 10 parts by mass, more preferably 3 to 8 parts by mass, relative to 100 parts by mass of the toner. If the content is less than 2 parts by mass, the high-temperature offset resistance and low-temperature fixability during fixing may be poor, and if it exceeds 10 parts by mass, the heat-resistant storage stability may be deteriorated and image fogging may be easily caused. If the content is within the above more preferred range, it is advantageous in terms of improving image quality and fixing stability.

[0135] <Coloring agent> The colorant is not particularly limited and can be appropriately selected depending on the purpose. Examples of the colorant include carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, yellow ochre, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Balkan fast yellow (5G, R), tartrazine lake, quinoline yellow lake, and anthrazan yellow BG. L, Isoindolinone Yellow, Bengala, Red Lead, Cinnabar, Cadmium Red, Cadmium Mercury Red, Antimony Vermilion, Permanent Red 4R, Para Red, Phaysee Red, Parachlor Orthonitroaniline Red, Lithol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Kanmin BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Lithol Rubin GX, Permanent Red F5R, Brilliant Riant Carmine 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline Blue - Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine Blue, Prussian Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chromium Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake,Examples include malachite green lake, phthalocyanine green, anthraquinone green, titanium oxide, zinc oxide, and lithopone. The content of the colorant is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 part by mass to 15 parts by mass, and more preferably 3 parts by mass to 10 parts by mass, relative to 100 parts by mass of the toner.

[0136] The colorant may also be used as a master batch in which it is combined with a resin. Examples of resins to be used in the preparation of a masterbatch or to be kneaded with a masterbatch include, in addition to the hybrid resins, polymers of styrene or its substitutes, such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene; styrene-p-chlorostyrene copolymers, styrene-propylene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, styrene-methyl acrylate copolymers, styrene-ethyl acrylate copolymers, styrene-butyl acrylate copolymers, styrene-octyl acrylate copolymers, styrene-methyl methacrylate copolymers, styrene-ethyl methacrylate copolymers, styrene-butyl methacrylate copolymers, styrene-α-methyl chloromethacrylate copolymers, styrene-acrylonitrile copolymers, styrene-vinyl methyl ketone copolymers, styrene-butadiene copolymers, styrene-isoprene copolymers, styrene-acrylonitrile-indene copolymers, styrene-maleic acid copolymers, and styrene-maleic acid ester copolymers; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resins, epoxy polyol resins, polyurethanes, polyamides, polyvinyl butyrates, and other styrene-based copolymers. Examples of the resins include polyacrylic resins, rosin, modified rosin, terpene resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffin, paraffin wax, etc. These may be used alone or in combination of two or more.

[0137] The master batch can be obtained by mixing and kneading the resin and colorant for the master batch under high shear force. In this case, an organic solvent can be used to enhance the interaction between the colorant and the resin. In addition, a method called the flushing method, in which an aqueous paste containing water of the colorant is mixed and kneaded with the resin and organic solvent to transfer the colorant to the resin side and remove the water and organic solvent components, is also preferably used because it does not require drying since the wet cake of the colorant can be used as it is. A high shear dispersing device such as a three-roll mill is preferably used for mixing and kneading.

[0138] -Polymer (prepolymer) having a site capable of reacting with an active hydrogen group-containing compound- The polymer having a site capable of reacting with the active hydrogen group-containing compound (sometimes referred to as a "prepolymer") is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include polyol resins, polyacrylic resins, polyester resins, epoxy resins, and derivatives thereof. These may be used alone or in combination of two or more. Among these, polyester resins are preferred in terms of high fluidity and transparency when melted.

[0139] Examples of the site of the prepolymer that can react with the active hydrogen group-containing compound include an isocyanate group, an epoxy group, a carboxyl group, a functional group represented by -COCl, etc. These may be used alone or in combination of two or more. Of these, an isocyanate group is preferred.

[0140] The prepolymer is not particularly limited and can be appropriately selected depending on the purpose, but a polyester resin having an isocyanate group or the like capable of generating a urea bond is preferred, in that it is easy to adjust the molecular weight of the polymer component, and it has oil-less low-temperature fixing properties in a dry toner, and in particular, it can ensure good releasability and fixability even when there is no mechanism for applying release oil to the heating medium for fixing.

[0141] -Active hydrogen group-containing compounds- The active hydrogen group-containing compound acts as an elongation agent, a crosslinking agent, or the like when a polymer having a site capable of reacting with the active hydrogen group-containing compound undergoes an elongation reaction, a crosslinking reaction, or the like in an aqueous medium.

[0142] The active hydrogen group is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a hydroxyl group (alcoholic hydroxyl group and phenolic hydroxyl group), an amino group, a carboxyl group, a mercapto group, etc. These may be used alone or in combination of two or more kinds.

[0143] The active hydrogen group-containing compound is not particularly limited and can be appropriately selected according to the purpose, but when the polymer having a site capable of reacting with the active hydrogen group-containing compound is a polyester resin containing an isocyanate group, amines are preferred because they can be made high molecular weight by elongation reaction, crosslinking reaction, etc. with the polyester resin. The amines are not particularly limited and can be appropriately selected according to the purpose, and examples thereof include diamines, trivalent or higher amines, amino alcohols, amino mercaptans, amino acids, and those in which the amino groups are blocked. These may be used alone or in combination of two or more. Among these, diamines and mixtures of diamines with small amounts of trivalent or higher amines are preferred.

[0144] The diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include aromatic diamines, alicyclic diamines, and aliphatic diamines. The aromatic diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include phenylenediamine, diethyltoluenediamine, and 4,4'-diaminodiphenylmethane. The alicyclic diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diaminocyclohexane, and isophoronediamine. The aliphatic diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include ethylenediamine, tetramethylenediamine, and hexamethylenediamine.

[0145] The trivalent or higher amine is not particularly limited and can be appropriately selected depending on the purpose. Examples of the trivalent or higher amine include diethylenetriamine and triethylenetetramine.

[0146] The amino alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples of the amino alcohol include ethanolamine and hydroxyethylaniline. The amino mercaptan is not particularly limited and can be appropriately selected depending on the purpose. Examples of the amino mercaptan include aminoethyl mercaptan and aminopropyl mercaptan.

[0147] The amino acid is not particularly limited and can be appropriately selected depending on the purpose. Examples of the amino acid include aminopropionic acid and aminocaproic acid. The blocked amino group is not particularly limited and can be appropriately selected depending on the purpose. Examples of the blocked amino group include ketimine compounds obtained by blocking the amino group with ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone, and oxazoline compounds.

[0148] -Polyester resin containing isocyanate groups- The polyester resin containing an isocyanate group (hereinafter, sometimes referred to as a "polyester prepolymer having an isocyanate group") is not particularly limited and can be appropriately selected depending on the purpose. For example, a reaction product of a polyester resin having an active hydrogen group obtained by polycondensation of a polyol and a polycarboxylic acid and a polyisocyanate can be mentioned.

[0149] -Polyol- The polyol is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include diols, trihydric or higher alcohols, mixtures of diols and trihydric or higher alcohols, etc. These may be used alone or in combination of two or more kinds. Among these, diols and mixtures of diols with small amounts of trihydric or higher alcohols are preferred.

[0150] The diol is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include alkylene glycols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, and 1,6-hexanediol; diols having an oxyalkylene group such as diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; alicyclic diols such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A; alicyclic diols to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide have been added; bisphenols such as bisphenol A, bisphenol F, and bisphenol S; and alkylene oxide adducts of bisphenols such as those to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide have been added to bisphenols. The number of carbon atoms of the alkylene glycol is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 2 to 12. Among these, alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols are preferred, and alkylene oxide adducts of bisphenols and mixtures of alkylene oxide adducts of bisphenols and alkylene glycols having 2 to 12 carbon atoms are more preferred.

[0151] The trihydric or higher alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples of the trihydric or higher alcohol include aliphatic trihydric or higher alcohols, trihydric or higher polyphenols, and alkylene oxide adducts of trihydric or higher polyphenols. The trihydric or higher aliphatic alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol. The trivalent or higher polyphenols are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include trisphenol PA, phenol novolac, and cresol novolac. Examples of the alkylene oxide adducts of trivalent or higher polyphenols include those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to trivalent or higher polyphenols. When the diol and the trihydric or higher alcohol are used in combination, the mass ratio of the trihydric or higher alcohol to the diol is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.01 mass % to 10 mass %, more preferably 0.01 mass % to 1 mass %.

[0152] -Polycarboxylic acid- The polycarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include dicarboxylic acids, trivalent or higher carboxylic acids, mixtures of dicarboxylic acids and trivalent or higher carboxylic acids, etc. These may be used alone or in combination of two or more. Among these, dicarboxylic acids and mixtures of dicarboxylic acids with a small amount of trivalent or higher polycarboxylic acids are preferred.

[0153] The dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples of the dicarboxylic acid include divalent alkanoic acids, divalent alkenoic acids, and aromatic dicarboxylic acids. The divalent alkanoic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples of the divalent alkanoic acid include succinic acid, adipic acid, and sebacic acid. The divalent alkenoic acid is not particularly limited and can be appropriately selected depending on the purpose, but is preferably a divalent alkenoic acid having 4 to 20 carbon atoms. The divalent alkenoic acid having 4 to 20 carbon atoms is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include maleic acid and fumaric acid. The aromatic dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, but is preferably an aromatic dicarboxylic acid having 8 to 20 carbon atoms. The aromatic dicarboxylic acid having 8 to 20 carbon atoms is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid.

[0154] The tri- or higher carboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples of the tri- or higher carboxylic acid include aromatic tri- or higher carboxylic acids. The trivalent or higher aromatic carboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, but is preferably a trivalent or higher aromatic carboxylic acid having 9 to 20 carbon atoms. The trivalent or higher aromatic carboxylic acid having 9 to 20 carbon atoms is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include trimellitic acid and pyromellitic acid.

[0155] As the polycarboxylic acid, anhydrides or lower alkyl esters of any of dicarboxylic acids, tri- or higher carboxylic acids, and mixtures of dicarboxylic acids and tri- or higher carboxylic acids can also be used. The lower alkyl ester is not particularly limited and can be appropriately selected depending on the purpose. Examples of the lower alkyl ester include methyl ester, ethyl ester, and isopropyl ester. When the dicarboxylic acid and the tri- or higher carboxylic acid are used in combination, the mass ratio of the tri- or higher carboxylic acid to the dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.01% by mass to 10% by mass, and more preferably 0.01% by mass to 1% by mass.

[0156] When the polyol and the polycarboxylic acid are polycondensed, the equivalent ratio of the hydroxyl groups of the polyol to the carboxyl groups of the polycarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 to 2, more preferably 1 to 1.5, and particularly preferably 1.02 to 1.3.

[0157] The content of the polyol-derived structural unit in the polyester prepolymer having an isocyanate group is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5% by mass to 40% by mass, more preferably 1% by mass to 30% by mass, and particularly preferably 2% by mass to 20% by mass. If the content is less than 0.5% by mass, the high-temperature offset resistance decreases, and it may be difficult to achieve both the heat-resistant storage stability and low-temperature fixability of the toner. If the content exceeds 40% by mass, the low-temperature fixability may decrease.

[0158] -Polyisocyanate- The polyisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples of the polyisocyanate include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, araliphatic diisocyanates, isocyanurates, and those blocked with phenol derivatives, oximes, caprolactam, etc.

[0159] The aliphatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples of the aliphatic diisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, methyl 2,6-diisocyanatocaproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, and tetramethylhexane diisocyanate.

[0160] The alicyclic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples of the alicyclic diisocyanate include isophorone diisocyanate and cyclohexylmethane diisocyanate.

[0161] The aromatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples of the aromatic diisocyanate include tolylene diisocyanate, diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4'-diisocyanatodiphenyl, 4,4'-diisocyanato-3,3'-dimethyldiphenyl, 4,4'-diisocyanato-3-methyldiphenylmethane, and 4,4'-diisocyanato-diphenyl ether.

[0162] The aromatic aliphatic diisocyanate is not particularly limited and may be appropriately selected depending on the purpose. Examples of the aromatic aliphatic diisocyanate include α,α,α',α'-tetramethylxylylene diisocyanate. The isocyanurates are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include tris(isocyanatoalkyl)isocyanurate, tris(isocyanatocycloalkyl)isocyanurate, etc. These may be used alone or in combination of two or more kinds.

[0163] When the polyisocyanate is reacted with a polyester resin having a hydroxyl group, the equivalent ratio of the isocyanate group of the polyisocyanate to the hydroxyl group of the polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 to 5, more preferably 1.2 to 4, and particularly preferably 1.5 to 3. If the equivalent ratio is less than 1, the offset resistance may decrease, and if it exceeds 5, the low-temperature fixability may decrease.

[0164] The content of the polyisocyanate-derived structural unit in the polyester prepolymer having an isocyanate group is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5% by mass to 40% by mass, more preferably 1% by mass to 30% by mass, and particularly preferably 2% by mass to 20% by mass. If the content is less than 0.5% by mass, high-temperature offset resistance may decrease, and if it exceeds 40% by mass, low-temperature fixability may decrease.

[0165] The average number of isocyanate groups in the polyester prepolymer having an isocyanate group per molecule is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 1 or more, more preferably 1.2 to 5, and particularly preferably 1.5 to 4. If the average number is less than 1, the molecular weight of the urea-modified polyester resin becomes low, and high-temperature offset resistance may decrease.

[0166] The mass ratio of the polyester prepolymer having an isocyanate group to the polyester resin containing 50 mol % or more of a propylene oxide adduct of bisphenols in the polyhydric alcohol component and having a specific hydroxyl value and acid value is not particularly limited and can be appropriately selected depending on the purpose, but is preferably less than 5 / 95 to more than 25 / 75, and more preferably 10 / 90 to 25 / 75. If the mass ratio is less than 5 / 95, high-temperature offset resistance may decrease, and if it exceeds 25 / 75, low-temperature fixability and image gloss may decrease.

[0167] -Charge control agent- The charge control agent is not particularly limited and can be appropriately selected depending on the purpose. Examples of the charge control agent include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdic acid chelate pigments, rhodamine dyes, alkoxy amines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substance or compounds, tungsten simple substance or compounds, fluorine-based activators, metal salicylic acid salts, and metal salts of salicylic acid derivatives. Specific examples include the nigrosine dye Bontron 03, the quaternary ammonium salt Bontron P-51, the metal-containing azo dye Bontron S-34, the oxynaphthoic acid metal complex E-82, the salicylic acid metal complex E-84, and the phenol condensate E-89 (all manufactured by Orient Chemical Industry Co., Ltd.), the quaternary ammonium salt molybdenum complexes TP-302 and TP-415 (both manufactured by Hodogaya Chemical Co., Ltd.), LRA-901, the boron complex LR-147 (manufactured by Nippon Carlit Co., Ltd.), copper phthalocyanine, perylene, quinacridone, azo pigments, and other polymeric compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts.

[0168] The content of the charge control agent is not particularly limited and can be appropriately selected according to the purpose, but is preferably 0.1 to 10 parts by mass, more preferably 0.2 to 5 parts by mass, relative to 100 parts by mass of the toner. If the content exceeds 10 parts by mass, the chargeability of the toner is too high, the effect of the main charge control agent is reduced, and the electrostatic attraction force with the developing roller increases, which may lead to a decrease in the fluidity of the developer and a decrease in image density. These charge control agents can be melt-kneaded together with the master batch and resin and then dissolved and dispersed, or of course they can be added when directly dissolved and dispersed in an organic solvent, or they can be fixed on the toner surface after the toner particles are produced.

[0169] The acid value of the toner is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5 mgKOH / g to 40 mgKOH / g in terms of controlling low-temperature fixability (lower limit temperature of fixation) and hot offset occurrence temperature. If the acid value is less than 0.5 mgKOH / g, the effect of improving dispersion stability by a base during production cannot be obtained, or when the prepolymer is used, the elongation reaction and / or crosslinking reaction may easily proceed, resulting in a decrease in production stability. If the acid value is more than 40 mgKOH / g, when the prepolymer is used, the elongation reaction and / or crosslinking reaction may be insufficient, resulting in a decrease in high-temperature offset resistance.

[0170] The glass transition temperature (Tg) of the toner is not particularly limited and can be appropriately selected depending on the purpose, but the glass transition temperature (Tg1st) calculated at the first temperature rise in DSC measurement is preferably 45° C. or more and less than 65° C., and more preferably 50° C. or more and 60° C. or less. This allows low-temperature fixability, heat-resistant storage stability, and high durability to be obtained. If the Tg1st is less than 45° C., blocking in the developing machine or filming on the photoreceptor may occur, and if it is 65° C. or more, the low-temperature fixability may decrease. The glass transition temperature (Tg2nd) calculated at the second temperature rise in the DSC measurement of the toner is preferably 20° C. or more and less than 40° C. If the Tg2nd is less than 20° C., blocking in a developing machine or filming on a photoreceptor may occur, and if it exceeds 40° C., low-temperature fixability may decrease.

[0171] The volume average particle diameter (D4) of the toner is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 3 μm to 7 μm. The ratio of D4 to the number average particle diameter (Dn) is preferably 1.2 or less. The toner preferably contains 1% to 10% by number of components having a volume average particle diameter of 2 μm or less.

[0172] <<Method of measuring acid value and hydroxyl value>> The hydroxyl value can be measured using a method in accordance with JIS K0070-1966. Specifically, 0.5 g of sample is weighed out into a 100 mL measuring flask and 5 mL of acetylation reagent is added to it. Next, the sample is heated in a 100±5°C hot bath for 1 to 2 hours, after which the flask is removed from the bath and allowed to cool. Water is then added and the flask is shaken to decompose the acetic anhydride. Next, in order to completely decompose the acetic anhydride, the flask is heated again in the hot bath for 10 minutes or more and allowed to cool, after which the walls of the flask are thoroughly washed with an organic solvent. In addition, the hydroxyl value is measured at 23°C using a potentiometric automatic titrator DL-53Titrator (Mettler Toledo) and an electrode DG113-SC (Mettler Toledo), and the results are analyzed using the analysis software LabX Light Version 1.00.000. A mixed solvent of 120 mL of toluene and 30 mL of ethanol is used to calibrate the apparatus. At this time, the measurement conditions are as follows:

[0173] [Measurement conditions] Stir Speed[%] 25 Time[s] 15 EQP titration Titrant / Sensor Titrant CH3ONa Concentration [mol / L] 0.1 Sensor DG115 Unit of measurement mV Predispensing to volume Volume [mL] 1.0 Wait time[s] 0 Titrant addition Dynamic dE(set)[mV] 8.0 dV(min)[mL] 0.03 dV(max)[mL] 0.5 Measure mode Equilibrium controlled dE[mV] 0.5 dt[s] 1.0 t(min)[s] 2.0 t(max)[s] 20.0 Recognition Threshold 100.0 Steepest jump only No Range No Tendency None Termination at maximum volume [mL] 10.0 at potential No at slope No After number EQPs Yes n=1 comb.termination conditions No Evaluation Procedure Standard Potential 1 No Potential2 No Stop for reevaluation

[0174] The acid value can be measured using a method in accordance with JIS K0070-1992. Specifically, 0.5 g of sample (0.3 g for ethyl acetate soluble matter) is added to 120 mL of toluene and dissolved by stirring at 23°C for about 10 hours. Next, 30 mL of ethanol is added to obtain the sample solution. If the sample does not dissolve, a solvent such as dioxane or tetrahydrofuran is used. Furthermore, the acid value is measured at 23°C using a potentiometric automatic titrator DL-53 Titrator (manufactured by Mettler Toledo) and an electrode DG113-SC (manufactured by Mettler Toledo), and the result is analyzed using the analysis software LabX Light Version 1.00.000. A mixed solvent of 120 mL of toluene and 30 mL of ethanol is used to calibrate the apparatus. In this case, the measurement conditions are the same as those for the hydroxyl value described above.

[0175] The acid value can be measured as described above. Specifically, the sample is titrated with a pre-standardized 0.1N potassium hydroxide / alcohol solution, and the acid value is calculated from the titration amount using the formula: acid value [mgKOH / g] = titration amount [mL] × N × 56.1 [mg / mL] / sample mass [g] (where N is the factor of the 0.1N potassium hydroxide / alcohol solution).

[0176] <<Melting point and glass transition temperature (Tg) measurement method>> The melting point and glass transition temperature (Tg) in the present invention can be measured, for example, by using a DSC system (differential scanning calorimeter) ("DSC-60", manufactured by Shimadzu Corporation). Specifically, the melting point and glass transition temperature of a sample can be measured by the following procedure. First, about 5.0 mg of the target sample is placed in an aluminum sample container, the sample container is placed on a holder unit, and set in an electric furnace. Next, in a nitrogen atmosphere, the sample is heated from 0°C to 150°C at a heating rate of 10°C / min. After that, the sample is cooled from 150°C to 0°C at a heating rate of 10°C / min, and further heated to 150°C at a heating rate of 10°C / min, and a DSC curve is measured using a differential scanning calorimeter ("DSC-60", manufactured by Shimadzu Corporation). From the obtained DSC curves, the DSC curve at the first heating up can be selected using the analysis program "Endothermic Shoulder Temperature" in the DSC-60 system, and the glass transition temperature at the first heating up of the target sample can be obtained. Also, the DSC curve at the second heating up can be selected using "Endothermic Shoulder Temperature", and the glass transition temperature at the second heating up of the target sample can be obtained. From the obtained DSC curves, the DSC curve at the first heating up can be selected using the analysis program "Endothermic Peak Temperature" in the DSC-60 system, and the melting point of the target sample at the first heating up can be obtained. Also, the DSC curve at the second heating up can be selected using "Endothermic Peak Temperature", and the melting point of the target sample at the second heating up can be obtained.

[0177] In the present invention, when a toner is used as a target sample, the glass transition temperature during the first heating is designated as Tg1st, and the glass transition temperature during the second heating is designated as Tg2nd. In the present invention, the melting point, Tg, of each component during the second heating is taken as the melting point, Tg, of each sample.

[0178] <<Method of measuring particle size distribution>> The volume average particle diameter (D4) and number average particle diameter (Dn) of the toner, and the ratio thereof (D4 / Dn) can be measured using, for example, a Coulter Counter TA-II or a Coulter Multisizer II (both manufactured by Coulter, Inc.). In the present invention, a Coulter Multisizer II was used. The measurement method is described below. First, 0.1 mL to 5 mL of a surfactant (preferably polyoxyethylene alkyl ether (nonionic surfactant)) is added as a dispersant to 100 mL to 150 mL of the electrolyte solution. Here, the electrolyte solution is a 1 mass % NaCl aqueous solution prepared using first-class sodium chloride, and for example, ISOTON-II (manufactured by Coulter) can be used. Then, 2 mg to 20 mg of a measurement sample is further added. The electrolyte solution in which the sample is suspended is subjected to a dispersion treatment for about 1 minute to 3 minutes using an ultrasonic disperser, and the volume and number of toner particles or toner are measured using a 100 μm aperture as the aperture with the above-mentioned measuring device to obtain the volume distribution and individual distribution. The number distribution is calculated. From the distribution obtained, the volume average particle diameter (D4) and number average particle diameter (Dn) of the toner can be obtained. Thirteen channels are used: 2.00 μm or more but less than 2.52 μm; 2.52 μm or more but less than 3.17 μm; 3.17 μm or more but less than 4.00 μm; 4.00 μm or more but less than 5.04 μm; 5.04 μm or more but less than 6.35 μm; 6.35 μm or more but less than 8.00 μm; 8.00 μm or more but less than 10.08 μm; 10.08 μm or more but less than 12.70 μm; 12.70 μm or more but less than 16.00 μm; 16.00 μm or more but less than 20.20 μm; 20.20 μm or more but less than 25.40 μm; 25.40 μm or more but less than 32.00 μm; and 32.00 μm or more but less than 40.30 μm, and the target particles are 2.00 μm or more but less than 40.30 μm in diameter.

[0179] -Inorganic fine particles- The inorganic fine particles used as an external additive can be used in combination with hydrophobized inorganic fine particles, the average particle size of which is preferably 1 nm to 200 nm, more preferably 10 nm to 150 nm. It is also preferable that the inorganic fine particles contain at least one type of inorganic fine particles whose average particle size of the hydrophobized primary particles is 30 nm or less, and at least one type of inorganic fine particles whose average particle size is 50 nm or more. When the average particle size of the inorganic fine particles is 50 nm or more, they are easily blocked by the blade, improving filming and cleaning. The specific surface area according to the BET method is 20 m 2 / g~500m 2 It is preferable that the molecular weight is 1 / g.

[0180] The inorganic fine particles are not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include silica fine particles, hydrophobic silica, metal oxides (such as titania, alumina, tin oxide, and antimony oxide), and fluoropolymers.

[0181] The content of the inorganic fine particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5 parts by mass or more and 6.0 parts by mass or less, and more preferably 1.0 parts by mass or more and 4.0 parts by mass or less, relative to 100 parts by mass of the toner base particles.

[0182] -Fatty acid metal salts- The most common industrial manufacturing methods for fatty acid metal salts used as external additives are a wet method in which fatty acids are saponified with caustic soda or caustic potash to form an alkali soap, which is then reacted with a metal salt to obtain a metal soap, and a dry method in which fatty acids are reacted with a metal oxide or hydroxide to obtain a metal soap. Methods for microparticulating fatty acid metal salts include dry pulverization using compressed air after drying the metal soap obtained by the wet or dry method, or a method in which the metal soap is dispersed in silicone oil or the like and then wet pulverized in a bead mill.

[0183] The fatty acid metal salt is not particularly limited, and examples thereof include zinc stearate and aluminum stearate.

[0184] The content of the fatty acid metal salt is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.05 parts by mass or more and 0.20 parts by mass or less, and more preferably 0.08 parts by mass or more and 0.16 parts by mass or less, relative to 100 parts by mass of the toner base particles.

[0185] <<Other external additives>> Other additives include titania, titanium oxide, and alumina fine particles. Examples of titania fine particles include P-25 (manufactured by Nippon Aerosil Co., Ltd.), STT-30, STT-65C-S (all manufactured by Titanium Kogyo Co., Ltd.), TAF-140 (manufactured by Fuji Titanium Kogyo Co., Ltd.), MT-150W, MT-500B, MT-600B, and MT-150A (all manufactured by Teika Co., Ltd.).

[0186] Examples of hydrophobically treated titanium oxide microparticles include T-805 (manufactured by Nippon Aerosil Co., Ltd.), STT-30A, STT-65S-S (all manufactured by Titanium Kogyo Co., Ltd.), TAF-500T, TAF-1500T (all manufactured by Fuji Titanium Kogyo Co., Ltd.), MT-100S, MT-100T (all manufactured by Teika Corporation), and IT-S (manufactured by Ishihara Sangyo Co., Ltd.).

[0187] Hydrophobized oxide particles, hydrophobized silica particles, hydrophobized titania particles, and hydrophobized alumina particles can be obtained by treating hydrophilic particles with a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, octyltrimethoxysilane, etc. Silicone oil-treated oxide particles and inorganic particles, which are treated with silicone oil by heating if necessary, are also suitable.

[0188] Examples of the silicone oil include dimethyl silicone oil, methylphenyl silicone oil, chlorophenyl silicone oil, methylhydrogen silicone oil, alkyl-modified silicone oil, fluorine-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, epoxy-polyether-modified silicone oil, phenol-modified silicone oil, carboxyl-modified silicone oil, mercapto-modified silicone oil, acrylic, methacrylic-modified silicone oil, and α-methylstyrene-modified silicone oil. Examples of inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, copper oxide, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengalla, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, silica and titanium dioxide are particularly preferred.

[0189] The content of the external additive is not particularly limited and can be appropriately selected depending on the purpose, but is preferably from 0.1% by mass to 5% by mass, and more preferably from 0.3% by mass to 3% by mass, based on the toner. The average particle size of the primary particles of the inorganic fine particles is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 200 nm or less, more preferably 10 nm to 100 nm. If it is smaller than this range, the inorganic fine particles are buried in the toner and their function is not effectively exerted. If it is larger than this range, the photoconductor surface is damaged unevenly, which is not preferable.

[0190] <<Other ingredients>> The other components are not particularly limited and may be appropriately selected depending on the purpose. Examples of the other components include magnetic materials, cleaning improvers, flow improvers, and charge control agents.

[0191] -Flow improver- The flowability improver is not particularly limited as long as it is capable of performing a surface treatment to increase hydrophobicity and prevent deterioration of flowability and charging properties even under high humidity, and can be appropriately selected according to the purpose, and examples thereof include silane coupling agents, silylating agents, silane coupling agents having a fluorinated alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, modified silicone oils, etc. It is particularly preferable that the silica and titanium oxide are surface-treated with such a flowability improver and used as hydrophobic silica and hydrophobic titanium oxide.

[0192] -Cleaning improver- The cleaning property improver is not particularly limited as long as it is added to the toner to remove the developer remaining on the photoconductor or primary transfer medium after transfer, and can be appropriately selected depending on the purpose, and examples thereof include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles, etc. The polymer fine particles preferably have a relatively narrow particle size distribution, and are preferably ones having a volume average particle size of 0.01 μm to 1 μm.

[0193] -Magnetic materials- The magnetic material is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include iron powder, magnetite, ferrite, etc. Among these, those that are white in color are preferred.

[0194] <Toner manufacturing method> The method for producing the toner is not particularly limited and can be appropriately selected depending on the purpose. However, it is preferable that the toner is granulated by dispersing an oil phase containing at least the non-crystalline polyester resin, the crystalline polyester resin, the release agent, and the colorant in an aqueous medium. An example of the method for producing such a toner is a known dissolution suspension method. As another example of the toner manufacturing method, a method of forming toner base particles while producing a product (hereinafter, sometimes referred to as "adhesive substrate") by elongation reaction and / or crosslinking reaction between the active hydrogen group-containing compound and a polymer having a site capable of reacting with the active hydrogen group-containing compound is described below. In such a method, preparation of an aqueous medium, preparation of an oil phase containing toner materials, emulsification or dispersion of the toner materials, removal of organic solvent, etc. are performed.

[0195] - Preparation of aqueous medium (aqueous phase) - The aqueous medium can be prepared, for example, by dispersing resin particles in the aqueous medium. The amount of the resin particles added to the aqueous medium is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.5% by mass to 10% by mass. The resin particles are not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include surfactants, poorly water-soluble inorganic compound dispersants, and polymer-based protective colloids. These may be used alone or in combination of two or more types. Among these, surfactants are preferred.

[0196] The aqueous medium is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include water, a solvent miscible with water, a mixture thereof, etc. These may be used alone or in combination of two or more. Of these, water is preferred. The water-miscible solvent is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include alcohol, dimethylformamide, tetrahydrofuran, cellosolves, lower ketones, etc. The alcohol is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include methanol, isopropanol, ethylene glycol, etc. The lower ketone is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include acetone, methyl ethyl ketone, etc.

[0197] - Preparation of oil phase - The oil phase containing the toner materials can be prepared by dissolving or dispersing the toner materials, including the active hydrogen group-containing compound, the polymer having a site capable of reacting with the active hydrogen group-containing compound, the crystalline polyester resin, the non-crystalline polyester resin, the release agent, the hybrid resin, and the colorant, in an organic solvent.

[0198] The organic solvent is not particularly limited and can be appropriately selected depending on the purpose, but an organic solvent having a boiling point of less than 150° C. is preferred in terms of ease of removal. The organic solvent having a boiling point of less than 150° C. is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, etc. These may be used alone or in combination of two or more. Among these, ethyl acetate, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, carbon tetrachloride, etc. are preferable, and ethyl acetate is more preferable.

[0199] -Emulsification or dispersion- The toner materials can be emulsified or dispersed by dispersing an oil phase containing the toner materials in the aqueous medium. When the toner materials are emulsified or dispersed, an active hydrogen group-containing compound and a polymer having a site capable of reacting with the active hydrogen group-containing compound undergo an elongation reaction and / or a crosslinking reaction to produce an adhesive substrate.

[0200] The adhesive substrate may be produced, for example, by emulsifying or dispersing an oil phase containing a polymer having reactivity with active hydrogen groups, such as a polyester prepolymer having an isocyanate group, together with a compound containing active hydrogen groups, such as amines, in an aqueous medium, and then carrying out an elongation reaction and / or crosslinking reaction between the two in the aqueous medium, or by emulsifying or dispersing an oil phase containing toner materials in an aqueous medium to which a compound having an active hydrogen group has been added in advance, and carrying out an elongation reaction and / or crosslinking reaction between the two in the aqueous medium, or by emulsifying or dispersing an oil phase containing toner materials in an aqueous medium, adding a compound having an active hydrogen group, and carrying out an elongation reaction and / or crosslinking reaction between the two from the particle interface in the aqueous medium. When carrying out an elongation reaction and / or crosslinking reaction between the two from the particle interface, the urea-modified polyester resin is preferentially formed on the surface of the toner produced, and a concentration gradient of the urea-modified polyester resin can also be provided in the toner.

[0201] The reaction conditions (reaction time, reaction temperature) for producing the adhesive base material are not particularly limited, and can be appropriately selected depending on the combination of the active hydrogen group-containing compound and the polymer having a site capable of reacting with the active hydrogen group-containing compound. The reaction time is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 minutes to 40 hours, and more preferably 2 hours to 24 hours. The reaction temperature is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0°C to 150°C, and more preferably 40°C to 98°C.

[0202] The method for stably forming a dispersion liquid containing a polymer having a site capable of reacting with an active hydrogen group-containing compound, such as a polyester prepolymer having an isocyanate group, in the aqueous medium is not particularly limited and may be appropriately selected depending on the purpose. For example, there is a method in which an oil phase prepared by dissolving or dispersing a toner material in a solvent is added to an aqueous medium phase, and the mixture is dispersed by shear force.

[0203] The dispersing machine for the dispersion is not particularly limited and can be appropriately selected depending on the purpose. Examples of the dispersing machine include a low-speed shear dispersing machine, a high-speed shear dispersing machine, a friction dispersing machine, a high-pressure jet dispersing machine, and an ultrasonic dispersing machine. Among these, a high-speed shear type disperser is preferred because it is possible to control the particle size of the dispersion (oil droplets) to 2 μm to 20 μm. When the high-speed shear type dispersing machine is used, the conditions such as the rotation speed, dispersing time, and dispersing temperature can be appropriately selected depending on the purpose. The rotation speed is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1,000 rpm to 30,000 rpm, and more preferably 5,000 rpm to 20,000 rpm. The dispersion time is not particularly limited and can be appropriately selected depending on the purpose, but in the case of a batch method, it is preferably 0.1 to 5 minutes. The dispersion temperature is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0° C. to 150° C. under pressure, and more preferably 40° C. to 98° C. In general, the higher the dispersion temperature, the easier the dispersion.

[0204] The amount of the aqueous medium used when emulsifying or dispersing the toner materials is not particularly limited and can be appropriately selected depending on the purpose. However, the amount is preferably 50 parts by mass to 2,000 parts by mass, and more preferably 100 parts by mass to 1,000 parts by mass, relative to 100 parts by mass of the toner materials. If the amount of the aqueous medium used is less than 50 parts by mass, the dispersion state of the toner materials may become poor, and toner base particles having the specified particle size may not be obtained. If the amount of the aqueous medium used is more than 2,000 parts by mass, the production cost may become high.

[0205] When the oil phase containing the toner materials is emulsified or dispersed, it is preferable to use a dispersant from the viewpoints of stabilizing the dispersion such as oil droplets, forming a desired shape, and sharpening the particle size distribution. The dispersant is not particularly limited and can be appropriately selected according to the purpose, and examples thereof include surfactants, poorly water-soluble inorganic compound dispersants, polymer-based protective colloids, etc. These may be used alone or in combination of two or more. Among these, surfactants are preferred.

[0206] The surfactant is not particularly limited and can be appropriately selected depending on the purpose. For example, anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, etc. can be used. The anionic surfactant is not particularly limited and can be appropriately selected depending on the purpose. Examples of the anionic surfactant include alkylbenzene sulfonate, α-olefin sulfonate, and phosphoric acid ester. Among these, those having a fluoroalkyl group are preferred.

[0207] A catalyst may be used in the elongation reaction and / or crosslinking reaction in producing the adhesive substrate. The catalyst is not particularly limited and can be appropriately selected depending on the purpose. Examples of the catalyst include dibutyltin laurate and dioctyltin laurate.

[0208] -Removal of organic solvents- The method for removing the organic solvent from the dispersion liquid such as the emulsified slurry is not particularly limited and can be appropriately selected depending on the purpose. For example, the method includes a method of gradually increasing the temperature of the entire reaction system to evaporate the organic solvent in the oil droplets, a method of spraying the dispersion liquid in a dry atmosphere to remove the organic solvent in the oil droplets, and the like. When the organic solvent is removed, toner base particles are formed. The toner base particles can be washed, dried, etc., and can further be classified, etc. The classification can be performed by removing fine particles in a liquid using a cyclone, decanter, centrifugal separation, etc., or the classification operation can be performed after drying.

[0209] The obtained toner base particles may be mixed with particles of the external additive, the charge control agent, etc. At this time, by applying a mechanical impact force, it is possible to suppress the particles of the external additive, etc. from being detached from the surface of the toner base particles. The method of applying the mechanical impact force is not particularly limited and can be appropriately selected depending on the purpose. Examples of the method include a method of applying an impact force to the mixture using a blade rotating at high speed, and a method of introducing the mixture into a high-speed air stream and accelerating it to cause particles to collide with each other or against an appropriate collision plate. The apparatus used in the above method is not particularly limited and can be appropriately selected depending on the purpose. Examples of the apparatus include Angmill (manufactured by Hosokawa Micron Corporation), an apparatus obtained by modifying an I-type mill (manufactured by Japan Pneumatic Mfg. Co., Ltd.) to reduce the grinding air pressure, a Hybridization System (manufactured by Nara Machinery Works, Ltd.), a Cryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), an automatic mortar, and the like.

[0210] <Developer> The developer of the present invention contains at least the toner, and optionally contains other components such as a carrier that are appropriately selected. For this reason, it is possible to stably form high-quality images with excellent transferability, charging property, etc. The developer may be a one-component developer or a two-component developer, but when used in a high-speed printer corresponding to the recent improvement in information processing speed, a two-component developer is preferable because of its improved life. When the developer is used as a one-component developer, even if the toner is balanced, there is little variation in the particle size of the toner, there is little filming of the toner on the developing roller, and there is little melting of the toner to components such as blades that thin the toner layer, and good and stable developability and images can be obtained even with long-term stirring in the developing device. When the developer is used as a two-component developer, the particle size of the toner changes little even when the toner is balanced over a long period of time, and good and stable developability and images can be obtained even when the toner is stirred for a long period of time in a developing device. When the toner is used in a two-component developer, it may be mixed with the carrier. The content of the carrier in the two-component developer is not particularly limited and may be appropriately selected depending on the purpose, but is preferably 90% by mass to 98% by mass, more preferably 93% by mass to 97% by mass.

[0211] <Career> The carrier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably one having a core material and a resin layer covering the core material.

[0212] -Core material- The material of the core material is not particularly limited and can be appropriately selected according to the purpose, and examples thereof include manganese-strontium-based materials and manganese-magnesium-based materials of 50 emu / g to 90 emu / g. In order to ensure image density, it is preferable to use high magnetization materials such as iron powder of 100 emu / g or more and magnetite of 75 emu / g to 120 emu / g. In addition, it is preferable to use low magnetization materials such as copper-zinc-based materials of 30 emu / g to 80 emu / g, since it can reduce the impact of the developer in a standing state on the photoconductor and is advantageous for improving image quality. These may be used alone or in combination of two or more.

[0213] The volume average particle size of the core material is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 10 μm to 150 μm, and more preferably 40 μm to 100 μm. If the volume average particle diameter is less than 10 μm, the amount of fine powder in the carrier increases, the magnetization per particle decreases, and the carrier may scatter. If the volume average particle diameter exceeds 150 μm, the specific surface area decreases, and the toner may scatter. In particular, in full color toners that have many solid areas, the reproduction of the solid areas may become poor.

[0214] -Resin layer- The material for the resin layer is not particularly limited and can be appropriately selected from known resins depending on the purpose. Examples of the material include amino-based resins, polyvinyl-based resins, polystyrene-based resins, polyhalogenated olefins, polyester-based resins, polycarbonate-based resins, polyethylene, polyvinyl fluoride, polyvinylidene fluoride, polytrifluoroethylene, polyhexafluoropropylene, fluoro terpolymers such as copolymers of vinylidene fluoride and an acrylic monomer, copolymers of vinylidene fluoride and vinyl fluoride, copolymers of tetrafluoroethylene, vinylidene fluoride and a monomer not having a fluoro group, and silicone resins. These may be used alone or in combination of two or more.

[0215] The amino resin is not particularly limited and can be appropriately selected depending on the purpose. Examples of the amino resin include urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, and epoxy resin. The polyvinyl resin is not particularly limited and can be appropriately selected depending on the purpose. Examples of the polyvinyl resin include acrylic resin, polymethyl methacrylate, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, and polyvinyl butyral. The polystyrene-based resin is not particularly limited and can be appropriately selected depending on the purpose. Examples of the polystyrene-based resin include polystyrene and styrene-acrylic copolymers. The polyhalogenated olefin is not particularly limited and can be appropriately selected depending on the purpose. For example, polyvinyl chloride is included. The polyester resin is not particularly limited and may be appropriately selected depending on the purpose. Examples of the polyester resin include polyethylene terephthalate and polybutylene terephthalate.

[0216] The resin layer may contain conductive powder, etc., if necessary. The conductive powder is not particularly limited and may be appropriately selected depending on the purpose, and examples thereof include metal powder, carbon black, titanium oxide, tin oxide, zinc oxide, etc. The average particle diameter of the conductive powder is preferably 1 μm or less. If the average particle diameter exceeds 1 μm, it may be difficult to control the electrical resistance.

[0217] The resin layer can be formed by preparing a coating solution by dissolving a silicone resin or the like in a solvent, coating the coating solution on the surface of the core material using a known coating method, drying, and then baking. The coating method is not particularly limited and may be appropriately selected depending on the purpose. For example, a dip coating method, a spray method, a brush coating method, etc. may be used. The solvent is not particularly limited and can be appropriately selected depending on the purpose. Examples of the solvent include toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, and butyl cellosolve acetate. The baking may be performed by an external heating method or an internal heating method, and examples of the method include a method using a fixed electric furnace, a flow type electric furnace, a rotary type electric furnace, a burner furnace, etc., a method using microwaves, etc.

[0218] The content of the resin layer in the carrier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 0.01% by mass to 5.0% by mass. If the content is less than 0.01% by mass, a uniform resin layer may not be formed on the surface of the core material, and if it exceeds 5.0% by mass, the resin layer is too thick and fusion between carrier particles may occur, resulting in a decrease in uniformity of the carrier.

[0219] (Toner storage unit) The toner storage unit in the present invention refers to a unit having a function of storing toner and storing the toner. Examples of the toner storage unit include a toner storage container, a developing unit, and a process cartridge. The toner storage container refers to a container that stores toner. The developing device has a means for containing toner and developing the toner.

[0220] <Process cartridge> The process cartridge according to the present invention is formed so as to be detachably mountable to various image forming apparatuses, and has at least a photoconductor for carrying an electrostatic latent image, and a developing means for developing the electrostatic latent image carried on the photoconductor with the developer of the present invention to form a toner image. The process cartridge of the present invention may further have other means as necessary. The developing means includes at least a developer container for containing the developer of the present invention, and a developer carrier for carrying and transporting the developer contained in the developer container. The developing means may further include a regulating member for regulating the thickness of the developer carried.

[0221] By mounting the toner storage unit on an image forming apparatus and forming an image, it is possible to take advantage of the characteristics of the toner, which has excellent offset resistance, charge stability, stress resistance, and background scumming properties, and can provide high-definition, high-quality images over a long period of time, thereby forming high-quality, high-definition images with long-term image stability.

[0222] (Image forming apparatus and image forming method) The image forming apparatus of the present invention comprises at least an electrostatic latent image carrier, an electrostatic latent image forming means, and a developing means, and further comprises other means as necessary. The image forming method according to the present invention includes at least an electrostatic latent image forming step and a development step, and further includes other steps as necessary. The image forming method can be suitably performed by the image forming apparatus, the electrostatic latent image forming process can be suitably performed by the electrostatic latent image forming means, the developing process can be suitably performed by the developing means, and the other processes can be suitably performed by the other means.

[0223] More preferably, the image forming apparatus of the present invention includes an electrostatic latent image carrier, an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, a developing means provided with toner for developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image, a transfer means for transferring the toner image formed on the electrostatic latent image carrier to a surface of a recording medium, and a fixing means for fixing the toner image transferred to the surface of the recording medium. Furthermore, the image forming method of the present invention more preferably includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, a developing step of developing the electrostatic latent image formed on the electrostatic latent image carrier with toner to form a toner image, a transfer step of transferring the toner image formed on the electrostatic latent image carrier to a surface of a recording medium, and a fixing step of fixing the toner image transferred to the surface of the recording medium.

[0224] The toner is used in the developing means. Preferably, the toner image is formed by using a developer containing the toner and, if necessary, other components such as a carrier.

[0225] The development method may be a premix development method in which a premix developer in which toner and carrier are mixed in advance is replenished. In the premix development method, the amount of carrier that has increased in the development device is discharged as excess developer. This gradually refreshes the developer in the development device. This makes it possible to extend the replacement cycle associated with deterioration of the developer and to eliminate the trouble of replacing the developer.

[0226] <Electrostatic latent image carrier> The material, structure, and size of the electrostatic latent image carrier (hereinafter also referred to as "photoreceptor") are not particularly limited and can be appropriately selected from known materials. Examples of the material include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors such as polysilane and phthalopolymethine. Examples of the organic photoreceptor include a laminated type photoreceptor having a laminated structure in which a layer (charge generation layer) in which a charge generation material such as metal-free phthalocyanine or titanyl phthalocyanine is dispersed in a binder resin and a layer (charge transport layer) in which a charge transport material is dispersed in a binder resin are stacked on a support such as an aluminum drum, and a single-layer type photoreceptor having a single-layer photosensitive layer on a support in which both a charge generation material and a charge transport material are dispersed in a binder resin. In the case of a single-layer type photoreceptor, a hole transport material and an electron transport material can be added as charge transport materials to the photosensitive layer. An undercoat layer may be provided between the support and the multi-layer charge generating layer or the single-layer photosensitive layer.

[0227] <Electrostatic latent image forming means> The electrostatic latent image forming means is not particularly limited as long as it is a means for forming an electrostatic latent image on the electrostatic latent image carrier, and may be appropriately selected depending on the purpose. For example, there may be mentioned a means having at least a charging member that charges the surface of the electrostatic latent image carrier, and an exposure member that exposes the surface of the electrostatic latent image carrier to light in an imagewise manner.

[0228] <Developing method> The developing unit is not particularly limited as long as it is a developing unit that develops the electrostatic latent image formed on the electrostatic latent image carrier to form a visible image and has a toner, and can be appropriately selected depending on the purpose.

[0229] <Cleaning Method> The image forming apparatus of the present invention preferably has a cleaning means. As described above, the toner of the present invention has excellent cleaning properties. Therefore, by applying the toner to the image forming apparatus having a cleaning means, the cleaning properties are improved in the following respects. By improving the spacer effect of the toner base particles, the fluidity of the toner is maintained even under stress, improving the cleaning performance. When the external additive (silica) liberation rate A (mass %) satisfies the above-mentioned general formula (3), the external additive is sufficiently liberated from the toner on the photoreceptor, and a deposition layer (dam layer) of the external additive is formed in the cleaning blade nip, thereby achieving high cleaning performance.

[0230] The cleaning means is not particularly limited as long as it is capable of removing the toner remaining on the photoreceptor, and can be appropriately selected depending on the purpose. Examples of the cleaning means include a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, and a web cleaner.

[0231] <Other methods> Examples of the other means include a transfer means, a fixing means, a discharging means, a recycling means, and a control means.

[0232] Next, one embodiment of the method for forming an image by the image forming apparatus of the present invention will be described with reference to FIG.

[0233] An example of an image forming apparatus of the present invention is shown in Fig. 1. The color image forming apparatus 100A shown in Fig. 1 includes a photoconductor drum 10 (hereinafter sometimes referred to as "photoconductor 10") as the electrostatic latent image carrier, a charging roller 20 as the charging means, an exposure device 30 as the exposure means, a developing device 40 as the developing means, an intermediate transfer body 50, a cleaning device 60 as the cleaning means having a cleaning blade, and a static elimination lamp 70 as the static elimination means.

[0234] The intermediate transfer body 50 is an endless belt, and is designed to be movable in the direction of the arrow by three rollers 51 arranged inside and stretching it. Some of the three rollers 51 also function as transfer bias rollers capable of applying a predetermined transfer bias (primary transfer bias) to the intermediate transfer body 50. A cleaning device 90 having a cleaning blade is arranged near the intermediate transfer body 50. Also, a transfer roller 80 as the transfer means capable of applying a transfer bias for transferring (secondary transfer) a developed image (toner image) to a transfer paper P as a recording medium is arranged near the intermediate transfer body 50 so as to face the intermediate transfer body 50. Around the intermediate transfer body 50, a corona charger 52 for applying a charge to the toner image on the intermediate transfer body 50 is arranged between the contact portion between the photoconductor 10 and the intermediate transfer body 50 and the contact portion between the intermediate transfer body 50 and the transfer paper P in the rotation direction of the intermediate transfer body 50.

[0235] In the present embodiment, an elastic intermediate transfer belt can also be used as the intermediate transfer body 50. As the elastic intermediate transfer belt, for example, one in which a flexible elastic layer is laminated on a rigid base layer that provides comparative flexibility can be used. In order to prevent the intermediate transfer body 50 from meandering, a guide member for preventing deviation may be provided on the inner peripheral surface of the intermediate transfer body 50 .

[0236] Around the photosensitive drum 10, a black developing unit 45K, a yellow developing unit 45Y, a magenta developing unit 45M, and a cyan developing unit 45C are disposed directly facing each other. The black developing unit 45K includes a developer container 42K, a developer supply roller 43K, and a developing roller 44K. The yellow developing unit 45Y includes a developer container 42Y, a developer supply roller 43Y, and a developing roller 44Y. The magenta developing unit 45M includes a developer container 42M, a developer supply roller 43M, and a developing roller 44M. The cyan developing unit 45C includes a developer container 42C, a developer supply roller 43C, and a developing roller 44C. The developing belt 41 is an endless belt that is rotatably stretched around a plurality of belt rollers, and a part of the belt 41 contacts the electrostatic latent image carrier 10.

[0237] In a color image forming apparatus 100A shown in FIG. 1, for example, a charging roller 20 uniformly charges a photoconductor drum 10. An exposure device 30 exposes the photoconductor drum 10 imagewise to light to form an electrostatic latent image. The electrostatic latent image formed on the photoconductor drum 10 is developed by supplying toner from a developing device 40 to form a toner image. The toner image is transferred (primary transfer) onto an intermediate transfer body 50 by a voltage applied from a roller 51, and is further transferred (secondary transfer) onto a transfer paper P. As a result, a transfer image is formed on the transfer paper P. Note that residual toner on the photoconductor 10 is removed by a cleaning device 60, and the charge on the photoconductor 10 is temporarily removed by a discharging lamp 70.

[0238] Another example of the image forming apparatus of the present invention is shown in Fig. 2. The image forming apparatus 100B shown in Fig. 1 includes a copying machine main body 150, a paper feed table 200, a scanner 300, and an automatic document feeder (ADF) 400. An endless belt-like intermediate transfer body 50 is provided in the center of the copying machine main body 150. The intermediate transfer body 50 is stretched around support rollers 14, 15, and 16, and can rotate clockwise in FIG. 2. An intermediate transfer body cleaning device 17 for removing residual toner on the intermediate transfer body 50 is provided near the support roller 15. A tandem type developing device 120 is provided on the intermediate transfer body 50 stretched around the support rollers 14 and 15 along the conveying direction of the intermediate transfer body 50, in which four image forming means 120 for yellow, cyan, magenta, and black are arranged in a row facing each other. An exposure device 21, which is the exposure member, is provided near the tandem type developing device 120. A secondary transfer device 22 is provided on the side of the intermediate transfer body 50 opposite the side on which the tandem type developing device 120 is provided. In the secondary transfer device 22, a secondary transfer belt 24, which is an endless belt, is stretched around a pair of rollers 23, and the transfer paper transported on the secondary transfer belt 24 and the intermediate transfer body 50 can come into contact with each other. A fixing device 25, which is the fixing means, is disposed near the secondary transfer device 22. The fixing device 25 includes a fixing belt 26, which is an endless belt, and a pressure roller 27 disposed so as to be pressed against the fixing belt 26. In the tandem image forming apparatus, a sheet inverting device 28 is disposed near the secondary transfer device 22 and the fixing device 25 for inverting the transfer paper so that images can be formed on both sides of the transfer paper.

[0239] Next, a description will be given of the formation of a full-color image (color copy) using the tandem type developing device 120. That is, first, an original is set on the original table 130 of the automatic document feeder (ADF) 400, or the automatic document feeder 400 is opened and an original is set on the contact glass 32 of the scanner 300, and the automatic document feeder 400 is closed.

[0240] When a start switch (not shown) is pressed, the scanner 300 is driven after the original is transported and moved onto the contact glass 32 when an original is set on the automatic original transport device 400, or immediately when an original is set on the contact glass 32. Then, the first traveling body 33 and the second traveling body 34 travel. At this time, light from a light source is irradiated by the first traveling body 33, and the reflected light from the original surface is reflected by a mirror in the second traveling body 34, and is received by the reading sensor 36 through the imaging lens 35 to read the color original (color image), which is converted into image information of black, yellow, magenta, and cyan.

[0241] Then, the image information for black, yellow, magenta, and cyan is transmitted to the image forming means 120 (image forming means for black, image forming means for yellow, image forming means for magenta, and image forming means for cyan) in the tandem developing device 120. Then, in each image forming means, a toner image for black, yellow, magenta, and cyan is formed. That is, as shown in FIG. 3, each image forming means 120 (image forming means for black, image forming means for yellow, image forming means for magenta, and image forming means for cyan) in the tandem developing device 120 includes an electrostatic latent image carrier 10 (electrostatic latent image carrier for black 10K, electrostatic latent image carrier for yellow 10Y, electrostatic latent image carrier for magenta 10M, and electrostatic latent image carrier for cyan 10C), a charging device 20 which is the charging means for uniformly charging the electrostatic latent image carrier 10, and a charging device 20 which charges the electrostatic latent image carrier 10 based on each color image information. The image forming apparatus includes an exposure device that exposes the electrostatic latent image carrier to light (L in FIG. 3) in the form of an image corresponding to each color image to form an electrostatic latent image corresponding to each color image on the electrostatic latent image carrier, a developing device 61 that is the developing means that develops the electrostatic latent image with each color toner (black toner, yellow toner, magenta toner, and cyan toner) to form a toner image with each color toner, a transfer charger 62 for transferring the toner image onto the intermediate transfer body 50, a cleaning device 63, and a charge remover 64. Each image forming means 120 is capable of forming a single color image (black image, yellow image, magenta image, and cyan image) based on image information of the respective color. The black image formed on the black electrostatic latent image carrier 10K, the yellow image formed on the yellow electrostatic latent image carrier 10Y, the magenta image formed on the magenta electrostatic latent image carrier 10M, and the cyan image formed on the cyan electrostatic latent image carrier 10C are sequentially transferred (primary transfer) onto the intermediate transfer body 50 which is rotated by the support rollers 14, 15, and 16. Then, the black image, the yellow image, the magenta image, and the cyan image formed on the cyan electrostatic latent image carrier 10C are superimposed on the intermediate transfer body 50 to form a composite color image (color transfer image).

[0242] On the other hand, in the paper feed table 200, one of the paper feed rollers 142 is selectively rotated to feed a sheet (recording paper) from one of the paper feed cassettes 144 provided in multiple stages in the paper bank 143. The sheets are separated one by one by the separation roller 145 and sent to the paper feed path 146, then conveyed by the conveyance roller 147 and guided to the paper feed path 148 in the copying machine main body 150, where they are stopped by striking against the registration roller 49. Alternatively, the paper feed roller 142 is rotated to feed the sheets (recording paper) on the manual feed tray 54, and the sheets are separated one by one by the separation roller 52 and placed in the manual feed path 53, where they are also stopped by striking against the registration roller 49. The registration roller 49 is generally used while being grounded, but may be used with a bias applied to remove paper dust from the sheets. Then, the registration roller 49 is rotated in synchronization with the composite color image (color transfer image) composited on the intermediate transfer body 50, a sheet (recording paper) is sent between the intermediate transfer body 50 and the secondary transfer device 22, and the composite color image (color transfer image) is transferred (secondary transfer) onto the sheet (recording paper) by the secondary transfer device 22. In this way, a color image is transferred and formed on the sheet (recording paper). Note that residual toner on the intermediate transfer body 50 after the image transfer is cleaned by the intermediate transfer body cleaning device 17.

[0243] In the figure, the intermediate transfer body cleaning device 17 is arranged to clean the outer peripheral surface of the intermediate transfer body 50, but an intermediate transfer body cleaning device that cleans the inner peripheral surface of the intermediate transfer body 50 may be provided separately. The intermediate transfer body cleaning device 17 may have a cleaning means in the shape of a blade or a brush. A collecting means for receiving the toner and the like removed by the cleaning means may be provided. A dish-shaped tray or the like may be used as the collecting means.

[0244] The sheet (recording paper) on which the color image has been transferred and formed is transported by the secondary transfer device 22 and sent to the fixing device 25, where the composite color image (color transfer image) is fixed onto the sheet (recording paper) by heat and pressure. Thereafter, the sheet (recording paper) is switched by a switching claw 55, discharged by discharge rollers 56, and stacked on a paper output tray 57. Alternatively, the sheet is switched by a switching claw 55, inverted by a sheet inverting device 28, and guided to the transfer position again, an image is also recorded on the back side, and then the sheet is discharged by discharge rollers 56 and stacked on a paper output tray 57.

[0245] An example of a process cartridge according to the present invention is shown in Fig. 4. The process cartridge 110 has the photosensitive drum 10, a corona charger 52, a developing device 40, a transfer roller 80 and a cleaning device 90. EXAMPLES

[0246] Examples of the present invention will be described below, but the present invention is not limited to the following examples. In the following description, "parts" and "%" represent "parts by mass" and "% by mass", respectively.

[0247] - Toner manufacturing - (Production Example 1) [Production of Aqueous Dispersion (W0-1) of Resin Fine Particles (A)] In a reaction vessel equipped with a stirrer, a heating / cooling device, and a thermometer, 3710 parts of water and 200 parts of polyoxyethylene-1-(allyloxymethyl) alkyl ether sulfate ester ammonium (Aqualon KH-1025, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were charged and homogenized by stirring at 200 rpm. The homogenized mixture was heated to raise the temperature inside the system to 75° C., after which 90 parts of a 10% aqueous ammonium persulfate solution was added, and then a mixture consisting of 450 parts of styrene, 250 parts of butyl acrylate, and 300 parts of methacrylic acid was added dropwise over 4 hours. After the dropwise addition, the mixture was aged at 75° C. for 4 hours to obtain a fine particle dispersion (W0-1) containing a resin (a1-1), which is a polymer in which the monomer and polyoxyethylene-1-(allyloxymethyl) alkyl ether sulfate ester ammonium are copolymerized. The volume average particle size of the particles in [particle dispersion (W0-1)] was 15 nm when measured by dynamic light scattering (light scattering electrophoresis apparatus: ELS-8000, manufactured by Otsuka Electronics Co., Ltd.). A part of the [fine particle dispersion (W0-1)] was dried to isolate resin (a1-1). The resin had a glass transition temperature (TgA) of 75° C. and an acid value of 195 mg KOH / g.

[0248] (Production Example 2) [Production of Aqueous Dispersion (W0-2) of Resin Fine Particles (A)] In a reaction vessel equipped with a stirrer, a heating / cooling device, and a thermometer, 3810 parts of water and 100 parts of polyoxyethylene-1-(allyloxymethyl) alkyl ether sulfate ester ammonium (Aqualon KH-1025, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were charged and homogenized by stirring at 200 rpm. The homogenized mixture was heated to raise the temperature inside the system to 75° C., after which 90 parts of a 10% aqueous ammonium persulfate solution was added, and then a mixture consisting of 400 parts of styrene, 300 parts of butyl acrylate, and 300 parts of methacrylic acid was added dropwise over 4 hours. After the dropwise addition, the mixture was aged at 75° C. for 4 hours to obtain a fine particle dispersion (W0-2) containing a resin (a2-1), which is a polymer in which the monomer and polyoxyethylene-1-(allyloxymethyl) alkyl ether sulfate ester ammonium were copolymerized. The volume average particle size of the fine particles in [fine particle dispersion (W0-2)] was measured in the same manner as in Production Example 1 and was found to be 45 nm. A part of the [fine particle dispersion (W0-2)] was dried to isolate resin (a2-1). The resin had a glass transition temperature (TgA) of 65° C. and an acid value of 195 mg KOH / g.

[0249] (Production Example 3) <Production of Aqueous Dispersion (W-1) of Resin Fine Particles (A-1)> Next, 667 parts of [microparticle dispersion (W0-1)] and 248 parts of water were charged into a reaction vessel equipped with a stirrer, a heating / cooling device, and a thermometer, and 0.267 parts of tertiary butyl hydroperoxide (Perbutyl H, manufactured by NOF Corporation) was added. The system was then heated to raise the temperature inside the system to 70°C, and 43.3 parts of styrene, 23.3 parts of butyl acrylate, and 18.0 parts of a 1% aqueous ascorbic acid solution were added dropwise over 2 hours. After the dropwise addition, the mixture was allowed to mature at 70°C for 4 hours to obtain [microparticle dispersion (W-1)], which is an aqueous dispersion of resin microparticles (A-1) containing resin (a2-1), a polymer formed by copolymerization of the monomer using the resin microparticles in [microparticle dispersion (W0-1)] as seeds, and resin (a1-1) as constituent components within the same particle. The volume average particle size of the resin fine particles (A-1) was measured in the same manner as in Production Example 1 and was found to be 17.3 nm. [Fine particle dispersion (W-1)] was neutralized with 10% aqueous ammonia to pH 9.0, and the precipitate was centrifuged and dried to isolate resin (a2-1). The glass transition temperature (TgA) of the resin was 61°C.

[0250] It was confirmed as follows that the [microparticle dispersion (W-1)] contained resin microparticles (A-1) containing resin (a1-1) and resin (a2-1) as constituent components in the same particle. Specifically, 2 parts of gelatin (Cook Gelatin, Morinaga Milk Industry Co., Ltd.) was dissolved in 15 parts of water heated to 95°C to 100°C, and the gelatin solution was cooled to 40°C by air cooling. The gelatin solution was then mixed with [microparticle dispersion (W-1)] in a mass ratio of 1:1, thoroughly stirred, and then cooled to 10°C for 1 hour to produce a hardened gel. This gel was sliced ​​into 80 nm-thick sections using an ultramicrotome (Ultramicrotome UC7, FC7, Leica Microsystems) while maintaining the temperature at -80°C. The sections were then stained with a 2% aqueous solution of ruthenium tetroxide for 5 minutes and then observed with a transmission electron microscope (Hitachi Technologies, H-7100) to confirm the results.

[0251] (Production Example 4) <Production of Aqueous Dispersion (W-2) of Resin Fine Particles (A-2)> Next, 667 parts of [microparticle dispersion (W0-2)] and 248 parts of water were charged into a reaction vessel equipped with a stirrer, a heating / cooling device, and a thermometer, and 0.267 parts of tertiary butyl hydroperoxide (Perbutyl H, manufactured by NOF Corporation) was added. The system was then heated to raise the temperature to 70°C, and 43.3 parts of styrene, 23.3 parts of butyl acrylate, and 18.0 parts of a 1% aqueous ascorbic acid solution were then added dropwise over 2 hours. After the dropping, the mixture was aged at 70°C for 4 hours to obtain [microparticle dispersion (W-2)], which is an aqueous dispersion of resin microparticles (A-2) containing resin (a2-2) and resin (a1-2) as constituents in the same particle, which are polymers obtained by copolymerizing the monomers using the resin microparticles in [microparticle dispersion (W0-2)] as seeds. The volume average particle size of the resin microparticles (A-2) was measured in the same manner as in Production Example 1 and was found to be 51.5 nm. [Fine particle dispersion (W-2)] was neutralized with 10% aqueous ammonia to pH 9.0, and the precipitate was centrifuged and dried to isolate resin (a2-2). The glass transition temperature (TgA) of the resin was 55°C. It was confirmed by the same method as in Production Example 4 that the [microparticle dispersion (W-2)] contained resin microparticles (A-2) containing resin (a1-2) and resin (a2-2) as constituent components in the same particle.

[0252] (Production Example 5) <Synthesis of non-crystalline polyester resin (b-1)> In a reaction vessel equipped with a condenser, a stirrer, a heating / cooling device, a thermometer, and a nitrogen inlet tube, 425 parts of bisphenol A·PO 2-mol adduct, 100 parts of propylene glycol, 634 parts of terephthalic acid·propylene glycol 2-mol adduct, and 0.5 parts of titanium diisopropoxybistriethanolamine as a condensation catalyst were placed and reacted at 230°C for 12 hours. Then, the reaction was carried out under a reduced pressure of 10 to 15 mmHg. The amount of propylene glycol recovered was 195 parts. Then, after cooling to 180° C., 30 parts of trimellitic anhydride was added and reacted at 180° C. for 1 hour, and then the mixture was taken out. The extracted resin was cooled to room temperature to obtain amorphous polyester resin (b-1). The resin had a glass transition temperature (Tg) of 42°C, a number average molecular weight (Mn) of 2400, a weight average molecular weight (Mw) of 5400, a hydroxyl value of 32 mgKOH / g, and an acid value of 18 mgKOH / g.

[0253] (Production Example 6) <Production of Colorant Dispersion> Into a reaction vessel equipped with a condenser, a stirrer, a heating / cooling device, a thermometer, and a nitrogen inlet tube, 557 parts of propylene glycol, 569 parts of dimethyl terephthalate, 184 parts of adipic acid, and 3 parts of tetrabutoxychinate as a condensation catalyst were charged, and the mixture was reacted for 8 hours under a nitrogen stream at 180° C. while distilling off the produced methanol. Next, while gradually increasing the temperature to 230° C., the reaction was carried out for 4 hours under a nitrogen stream while distilling off the produced propylene glycol and water, and further for 1 hour under a reduced pressure of 0.007 MPa to 0.026 MPa. The amount of propylene glycol recovered was 175 parts. Next, the mixture was cooled to 180°C, 121 parts of trimellitic anhydride was added, and the mixture was reacted for 2 hours under normal pressure in a sealed state. The mixture was then heated to 220°C under normal pressure and reacted until the softening point reached 180°C, yielding a polyester resin (number average molecular weight (Mn) = 8500). 20 parts of copper phthalocyanine, 4 parts of colorant dispersant (Solsperse 28000, manufactured by Avecia), 20 parts of the obtained polyester resin, and 56 parts of ethyl acetate were added to a beaker, and after stirring to uniformly disperse, the copper phthalocyanine was finely dispersed using a bead mill to obtain a [colorant dispersion]. The volume average particle size of the obtained [colorant dispersion] was 0.2 μm.

[0254] (Production Example 7) <Production of Modified Wax (d)> A pressure-resistant reaction vessel equipped with a stirrer, a heating / cooling device, a thermometer, and a dropping bomb was charged with 454 parts of xylene and 150 parts of low-molecular-weight polyethylene (SANWAX LEL-400, manufactured by Sanyo Chemical Industries, Ltd.), and after replacing with nitrogen, the temperature was raised to 170°C with stirring. At the same temperature, a mixed solution of 595 parts of styrene, 255 parts of methyl methacrylate, 34 parts of di-t-butylperoxyhexahydroterephthalate, and 119 parts of xylene was added dropwise over 3 hours, and the mixture was then maintained at the same temperature for a further 30 minutes. Next, the xylene was distilled off under a reduced pressure of 0.039 MPa to obtain a modified wax (d). The SP value of the graft chain of the modified wax (d) is 10.35 (cal / cm 3 ) 1 / 2 The number average molecular weight (Mn) was 1,900, the weight average molecular weight (Mw) was 5,200, and the glass transition temperature (Tg) was 57°C.

[0255] (Production Example 8) <Production of release agent dispersion> In a reaction vessel equipped with a cooling tube, a stirrer, a heating / cooling device, and a thermometer, 10 parts of paraffin wax (HNP-9, manufactured by Nippon Seiro Co., Ltd.), 1 part of modified wax (d), and 33 parts of ethyl acetate were added, heated to 78°C, stirred at the same temperature for 30 minutes, and then cooled to 30°C over 1 hour to crystallize the paraffin wax into fine particles, which were then wet-pulverized in an Ultraviscomill (manufactured by Imex) to obtain a [release agent dispersion]. The volume average particle size of the [release agent dispersion] was 0.25 μm.

[0256] (Production Example 9) <Production of reactive prepolymer (α2b-1)> Into a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube, 3-methyl-1,5-pentanediol, isophthalic acid, adipic acid, and trimellitic anhydride were added together with titanium tetraisopropoxide (1,000 ppm relative to the resin component) so that the molar ratio of hydroxyl groups to carboxyl groups, OH / COOH, was 1.5, the diol component was 100 mol% 3-methyl-1,5-pentanediol, the dicarboxylic acid component was 40 mol% isophthalic acid and 60 mol% adipic acid, and the amount of trimellitic anhydride in all monomers was 1 mol%. Thereafter, the temperature was raised to 200°C over about 4 hours, and then to 230°C over 2 hours, and the reaction was continued until no water was discharged. Thereafter, the mixture was further reacted for 5 hours under a reduced pressure of 10 mmHg to 15 mmHg to obtain [intermediate polyester C-1]. Next, [intermediate polyester C-1] and isophorone diisocyanate (IPDI) were added to a reaction vessel equipped with a cooling tube, a stirrer, and a nitrogen inlet tube in a molar ratio (isocyanate group of IPDI / hydroxyl group of intermediate polyester) of 2.0, and the mixture was diluted with ethyl acetate to become a 50% ethyl acetate solution. The mixture was reacted at 100°C for 5 hours to obtain [reactive prepolymer (α2b-1)].

[0257] The products of Production Examples 1 to 9 are shown in Table 1 below. [Table 1]

[0258] Example 1 <Production of toner base particles (C-1)> A beaker was charged with 165 parts of ion-exchanged water, a mixture of 5 parts of [microparticle dispersion (W-1)] and 10 parts of [microparticle dispersion (W0-1)], 1 part of sodium carboxymethylcellulose, 26 parts of sodium dodecyl diphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries, Ltd.), and 15 parts of ethyl acetate, and a mixed dispersion was obtained. Next, 71 parts of "non-crystalline polyester resin (b-1)" 40 parts of [colorant dispersion], 39 parts of [release agent dispersion], and 54 parts of ethyl acetate were added to another beaker and mixed, and then 18 parts of the reactive prepolymer (α2b-1) solution and 0.3 parts of isophoronediamine as a curing agent (β) were further added and mixed to obtain a mixed solution. The entire amount of this mixture was added to the dispersion prepared above, and the mixture was stirred for 2 minutes using a TK Auto Homomixer to obtain a mixture. Next, this mixture was transferred to a reaction vessel equipped with a stirrer and a thermometer, and dispersed for 5 minutes at a rotation speed of 5000 rpm using a high-speed shear disperser. The ethyl acetate was then distilled off at 50°C until the concentration became 0.5% or less, thereby carrying out a composite process, and an aqueous dispersion of toner base particles was obtained.

[0259] The aqueous dispersion of the toner base particles is a toner base particle in which fine particles including resin fine particles (A-1) are adhered to resin particles (B'-1) including a non-crystalline polyester resin (b-1) and a non-crystalline polyurethane resin (b-2) consisting of a reaction product of a reactive prepolymer (α2b-1) and isophoronediamine. It was confirmed that the resin particles contained in the aqueous dispersion of the toner base particles were toner base particles (C-1) in which fine particles including resin fine particles (A-1) were adhered to resin particles (B'-1) by magnifying and observing the shapes of the particles contained in the aqueous dispersion of the toner base particles with an electron microscope (scanning electron microscope: SU-8230 (manufactured by Hitachi High-Technologies Corporation)).

[0260] Next, sodium hydroxide was added so that the pH of the aqueous dispersion of toner base particles became 12, and the mixture was stirred for 1 hour with a three-one motor. After that, the mixture was centrifuged and ion-exchanged water was added again to make a reslurry. After repeating the process of centrifugal filtration and reslurrying several times, the mixture was filtered with suction using a membrane filter (hereinafter referred to as the "washing and filtering process") and dried at 40°C for 18 hours to reduce the volatile content to 0.5% or less, thereby obtaining toner base particles (C-1).

[0261] [Toner base particles (C-1)] was mixed with 100 parts of toner base particles, 1.5 parts of hydrophobic silica particles with an average particle size of 50 nm, 1.0 parts of hydrophobic titanium oxide with an average particle size of 20 nm, and 0.12 parts of zinc stearate in a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) for external addition treatment to obtain [Toner 1]. [Toner 1] had a volume average particle size of 5.5 μm, a ratio of the volume average particle size to the number average particle size of 1.1, and components with a volume average particle size of 2 μm or less were 4% by number.

[0262] For the obtained [Toner 1], the "number of coarse particles of 20 μm or more," "the coverage rate of the toner base particles with the resin particles," "the interparticle distance of the resin particles," and "the liberation rate A of silica (mass%)" of the toner particles were determined based on the measurement methods described above. The evaluation results are shown in Table 3.

[0263] Example 2 [Toner base particles (C-2)] and [Toner 2] were obtained in the same manner as in Example 1, except that in Example 1, 15 parts of a mixture of 5 parts of microparticle dispersion (W-1) and 10 parts of microparticle dispersion (W0-1) was changed to 15 parts of a mixture of 7.5 parts of microparticle dispersion (W-1) and 7.5 parts of microparticle dispersion (W0-1). The obtained [Toner 2] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

[0264] Example 3 [Toner base particles (C-3)] and [Toner 3] were obtained in the same manner as in Example 1, except that the amount of hydrophobic silica particles having an average particle size of 50 nm in Example 1 was changed from 1.5 parts to 2.3 parts as an external additive. The obtained [Toner 3] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

[0265] Example 4 [Toner base particles (C-4)] and [Toner 4] were obtained in the same manner as in Example 1, except that 15 parts of a mixture of 5 parts of the fine particle dispersion (W-1) and 10 parts of the fine particle dispersion (W0-1) in Example 1 was dispersed at a rotation speed of 30,000 rpm using a high-speed shear disperser. The obtained [Toner 4] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

[0266] Example 5 In Example 2, 15 parts of a mixture of 7.5 parts of microparticle dispersion (W-1) and 7.5 parts of microparticle dispersion (W0-1) was dispersed at a rotation speed of 30,000 rpm using a high-speed shear disperser, and the amount of hydrophobic silica particles having an average particle size of 50 nm was changed from 1.5 parts to 2.3 parts for external addition treatment, and the same procedure as in Example 2 was repeated to obtain [toner base particles (C-5)] and [toner 5]. The obtained [Toner 5] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

[0267] Example 6 In Example 1, 15 parts of a mixture of 5 parts of microparticle dispersion (W-1) and 10 parts of microparticle dispersion (W0-1) was changed to 15 parts of a mixture of 10 parts of microparticle dispersion (W-1) and 5 parts of microparticle dispersion (W0-1), which was dispersed at a rotation speed of 10,000 rpm using a high-speed shear disperser. In addition, the amount of hydrophobic silica particles having an average particle size of 50 nm was changed from 1.5 parts to 2.3 parts for external addition treatment. In the same manner as in Example 1, [toner base particles (C-6)] and [toner 6] were obtained. The obtained [Toner 6] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

[0268] Example 7 In Example 1, 15 parts of a mixture of 5 parts of the microparticle dispersion (W-1) and 10 parts of the microparticle dispersion (W0-1) was dispersed at a rotation speed of 10,000 rpm using a high-speed shear disperser, and the amount of hydrophobic silica particles having an average particle size of 50 nm was changed to 0.6 parts for external addition treatment, and the same procedure as in Example 1 was repeated to obtain [toner base particles (C-7)] and [toner 7]. The obtained [Toner 7] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

[0269] Example 8 In Example 2, 15 parts of a mixture of 7.5 parts of the microparticle dispersion (W-1) and 7.5 parts of the microparticle dispersion (W0-1) was dispersed at a rotation speed of 10,000 rpm using a high-speed shear disperser, and the amount of hydrophobic silica particles having an average particle size of 50 nm was changed to 2.3 parts for external addition treatment, and the same procedure as in Example 2 was repeated to obtain [toner base particles (C-8)] and [toner 8]. The obtained [Toner 8] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

[0270] Example 9 [Toner base particles (C-9)] and [Toner 9] were obtained in the same manner as in Example 6, except that the amount of hydrophobic silica particles having an average particle size of 50 nm was changed from 2.3 parts to 1.5 parts in Example 6. The obtained [Toner 9] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 3.

[0271] Comparative Example 1 [Toner base particles (C-10)] and [Toner 10] were obtained in the same manner as in Example 6, except that in Example 6, 15 parts of a mixture of 10 parts of microparticle dispersion (W-1) and 5 parts of microparticle dispersion (W0-1) was changed to 15 parts of a mixture of 11.25 parts of microparticle dispersion (W-2) and 3.75 parts of microparticle dispersion (W0-2). The obtained [Toner 10] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0272] Comparative Example 2 [Toner base particles (C-11)] and [Toner 11] were obtained in the same manner as in Comparative Example 1, except that in Comparative Example 1, 15 parts of a mixture of 11.25 parts of microparticle dispersion (W-2) and 3.75 parts of microparticle dispersion (W0-2) was changed to 15 parts of a mixture of 5 parts of microparticle dispersion (W-2) and 10 parts of microparticle dispersion (W0-2). The obtained [Toner 11] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0273] Comparative Example 3 [Toner base particles (C-12)] and [Toner 12] were obtained in the same manner as in Example 1, except that 15 parts of the mixed liquid was dispersed using a high-speed shear disperser at a rotation speed of 2000 rpm. The obtained [Toner 12] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0274] Comparative Example 4 [Toner base particles (C-13)] and [Toner 13] were obtained in the same manner as in Example 2, except that 15 parts of the mixed liquid was dispersed using a high-speed shear disperser at a rotation speed of 2000 rpm. The obtained [Toner 13] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0275] Comparative Example 5 [Toner base particles (C-14)] and [Toner 14] were obtained in the same manner as in Comparative Example 1, except that 15 parts of the mixed liquid was dispersed using a high-speed shear disperser at a rotation speed of 50,000 rpm. The obtained [Toner 14] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0276] Comparative Example 6 In Comparative Example 2, [toner base particles (C-15)] and [toner 15] were obtained in the same manner as in Comparative Example 2, except that 15 parts of the mixed liquid was dispersed using a high-speed shear disperser at a rotation speed of 50,000 rpm. The obtained [Toner 15] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0277] Comparative Example 7 In Comparative Example 1, [toner base particles (C-16)] and [toner 16] were obtained in the same manner as in Comparative Example 1, except that 15 parts of the mixed liquid was dispersed using a high-speed shear disperser at a rotation speed of 2000 rpm. The obtained [Toner 16] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0278] Comparative Example 8 In Comparative Example 2, [toner base particles (C-17)] and [toner 17] were obtained in the same manner as in Comparative Example 2, except that 15 parts of the mixed liquid was dispersed using a high-speed shear disperser at a rotation speed of 2000 rpm. The obtained [Toner 17] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0279] Comparative Example 9 [Toner base particles (C-18)] and [Toner 18] were obtained in the same manner as in Comparative Example 7, except that in Comparative Example 7, the amount of hydrophobic silica particles having an average particle size of 50 nm was changed to 3.3 parts and external addition treatment was performed. The obtained [Toner 18] was evaluated in the same manner as in Example 1. The evaluation results are shown in Table 4.

[0280] The components of the toners and the details of the external additive treatments in the examples and comparative examples are shown in Table 2 below.

[0281] [Table 2]

[0282] Next, the "abnormal image occurrence rate" and "transferability" were evaluated for each of the developers containing the toners of Examples 1 to 9 and Comparative Examples 1 to 9. The results are shown in Tables 3 and 4 below.

[0283] <Abnormal image occurrence rate> After filling a digital full-color multifunction printer (device name: Imagio MP C5000, manufactured by Ricoh Co., Ltd.) with each developer containing toner, A4 size, toner adhesion amount: 1.0 mg / cm 2 Then, the toner adhesion amount was set to 0.5, 1.0, 1, and 5 mg / cm. 2 A solid image was output and the number of abnormal images such as spots and white spots was counted. After that, the number of abnormal images was compared with the reference image of the toner installed in the same machine with the same ID to evaluate the "abnormal image occurrence rate." [Evaluation Criteria] ◎: The reduction rate of the number of abnormal images is 10% or more compared to the standard images. ○: The reduction rate of the number of abnormal images is between 0% and 10% compared to the reference images. △: The increase in the number of abnormal images is between 0% and 10% compared to the standard images. ×: Increase in the number of abnormal images is 10% or more compared to the standard images

[0284] <Transferability> After filling a digital full-color multifunction printer (device name: Imagio MP C5000, manufactured by Ricoh Co., Ltd.) with each developer containing toner, A4 size, toner adhesion amount: 1.0 mg / cm 2 A solid image of the same was copied 500 times. Next, the toner remaining on the photoconductor and the transfer residue on the photoconductor were transferred to a blank sheet of paper using Scotch tape (manufactured by Sumitomo 3M), and the ID was measured using a colorimeter (manufactured by Xrite, X-Rite938). In addition, the mass of the toner remaining on the intermediate transfer belt was measured, and the transfer rate was calculated from these values. The transferability was then evaluated by comparing it with a reference sample of the toner installed in the same machine. [Evaluation Criteria] ◎: Increase in transferability is 2% or more compared to the reference sample ○: The increase in transferability is 0.1% or more but less than 2% compared to the reference sample. △: The decrease in transferability is 0.1% or more but less than 2% compared to the reference sample. ×: The decrease in transferability is 2% or more compared to the reference sample.

[0285] [Table 3]

[0286] [Table 4]

[0287] As described above, excellent results in the rate of occurrence of abnormal images and transferability were obtained in Examples 1 to 9. The rate of occurrence of abnormal images and transferability were improved by controlling the coverage rate of the resin fine particles on the surface of the toner base particles and the number of coarse particles of 20 μm or more within specific ranges.

[0288] In contrast to this, in Comparative Example 1, the coverage of the resin fine particles on the surface of the toner base particle is excessively small, resulting in poor transferability. In Comparative Example 2, the coverage of the resin fine particles on the surface of the toner base particle is excessively large, so that a coating film of the external additive is difficult to form on the surface of the base particle, and transferability is deteriorated. In Comparative Examples 3 and 4, the number of coarse particles contained in the toner is excessively large, so that many abnormal images including spots are generated on the images. In Comparative Example 5, the number of coarse particles contained in the toner is too small, so that the toner particles aggregate around the cleaning blade to form coarse particles, resulting in abnormal images. Also, the coverage of the resin particles on the surface of the toner base particles is too small, resulting in poor transferability. In Comparative Example 6, the number of coarse particles contained in the toner is too small, so the toner particles aggregate around the cleaning blade to form coarse particles, resulting in abnormal images. Also, the coverage of the resin particles on the surface of the toner base particles is too high, resulting in poor transferability. In Comparative Example 7, the number of coarse particles contained in the toner is excessively large, and the coverage of the resin particles on the surface of the toner base particles is also excessively small, so that both the rate of occurrence of abnormal images and transferability are deteriorated. In Comparative Example 8, the number of coarse particles contained in the toner is excessively large, and the coverage of the toner base particle surfaces with the fine resin particles is also excessively large, so that both the rate of occurrence of abnormal images and transferability are deteriorated. In Comparative Example 9, the number of coarse particles contained in the toner is excessively large, the coverage of the resin fine particles on the surface of the toner base particles is excessively large, and the liberation rate of the external additive is also excessively high, so that both the rate of occurrence of abnormal images and transferability are deteriorated.

[0289] For example, aspects of the present invention are as follows. (1) A toner comprising toner base particles in which the surfaces of resin particles containing at least a binder resin and a wax are covered with resin fine particles, and an external additive, a coverage rate of the resin fine particles on the surface of the toner base particle is 30% or more and 70% or less, The number of coarse particles having a particle size of 20 μm or more per 1 g of the toner is 10 to 200. A toner characterized by: (2) The toner according to (1) above, wherein the average interparticle distance of the resin fine particles on the surface of the toner base particle is 10 nm or more and 600 nm or less. (3) The toner according to (1) above, wherein the number of coarse particles having a particle size of 20 μm or more per 1 g of the toner is from 10 to 100. (4) The toner according to (1) above, wherein a liberation rate A (% by mass) of silica contained in the toner satisfies the following relational expression (1): 0.3≦A≦2.0 (1) (5) A developer comprising the toner according to any one of (1) to (4) above. (6) A toner storage unit containing the toner according to any one of (1) to (4) above. (7) an electrostatic latent image carrier; an electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image bearing member; a developing unit for developing the electrostatic latent image to form a visible image by using the toner according to any one of the above (1) to (4); a transfer means for transferring the visible image onto a recording medium; A fixing means for fixing the transferred image on the recording medium; An image forming apparatus comprising: (8) forming an electrostatic latent image on an electrostatic latent image carrier; a developing step of developing the electrostatic latent image to form a visible image by using the toner according to any one of (1) to (4) above; a transfer step of transferring the visible image onto a recording medium; a fixing step of fixing the transferred image on the recording medium; An image forming method comprising the steps of: [Explanation of symbols]

[0290] 10 Electrostatic latent image carrier (photoconductor drum) 10K Black Electrostatic Latent Image Carrier 10Y Yellow electrostatic latent image carrier 10M Magenta electrostatic latent image carrier 10C Cyan electrostatic latent image carrier 14 Support roller 15 Support roller 16 Support roller 17 Cleaning equipment 18 Image forming means 20 Charging roller 21 Exposure equipment 22 Secondary transfer device 23 Laura 24 Secondary transfer belt 25 Fixing device 26 Fixing belt 27 Pressure roller 28 Sheet reversing device 32 Contact Glass 33 First Running Body 34 Second Running Body 35 Imaging Lens 36 Reading sensor 40 Developer 41 Developing belt 42K Developer compartment 42Y Developer storage unit 42M Developer compartment 42C Developer container 43K Developer supply roller 43Y Developer supply roller 43M Developer supply roller 43C Developer supply roller 44K developing roller 44Y Developing roller 44M Developing roller 44C Developing roller 45K Black Development Unit 45Y Yellow Development Unit 45M Magenta Development Unit 45C Cyan Development Unit 49 Registration roller 50 Intermediate transfer body 51 Lola 52 Separation roller 53 Manual feed path 54 Manual feed tray 55 Switching claw 56 Discharge roller 57 Output Tray 58 Corona charging device 60 Cleaning Equipment 61 Developing device 62 Transfer charger 63 Cleaning Equipment 64 Static electricity removal lamp 70 Static electricity removal lamp 80 Transfer roller 90 Cleaning Equipment 95 Transfer paper 100A, 100B, 100C image forming device 110 Process cartridge 120 Tandem type developer 130 Manuscript stand 142 Paper feed roller 143 Paper Bank 144 Paper feed cassette 145 Separation roller 146 Paper feed path 147 Transport roller 148 Paper feed path 150 Copying device body 160 Charging device 200 Paper feed table 300 Scanner 400 Automatic Document Feeder (ADF) L exposure light [Prior art documents] [Patent documents]

[0291] [Patent Document 1] JP 2002-284881 A [Patent Document 2] JP 2019-099809 A [Patent Document 3] JP 2019-143128 A [Patent Document 4] JP 2007-233030 A

Claims

1. A toner comprising toner base particles in which the surface of resin particles containing at least a binder resin and a wax is covered with resin fine particles, and an external additive, wherein the coverage rate of the resin fine particles on the surface of the toner base particles is 30% or more and 70% or less, and the number of coarse particles having a particle size of 20 μm or more is 10 or more and 200 or less per 1 g of the toner mass. The toner is characterized by the above.

2. The toner according to claim 1, wherein the average value of the interparticle distance of the resin fine particles on the surface of the toner base particles is 10 nm or more and 600 nm or less.

3. The toner according to claim 1, wherein the number of coarse particles having a particle size of 20 μm or more is 10 or more and 100 or less per 1 g of the toner mass.

4. The toner according to claim 1, wherein the free ratio A (mass%) of silica contained in the toner satisfies the following relational expression (1). 0.3 ≤ A ≤ 2.0 (1)

5. A developer comprising the toner according to any one of claims 1 to 4.

6. A toner container unit containing the toner according to any one of claims 1 to 4.

7. An electrostatic latent image carrier, electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, developing means for developing the electrostatic latent image to form a visible image using the toner according to any one of claims 1 to 4, transfer means for transferring the visible image onto a recording medium, fixing means for fixing the transferred image on the recording medium, and an image forming apparatus characterized by having the above.

8. An electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, a developing step of developing the electrostatic latent image to form a visible image using the toner according to any one of claims 1 to 4, a transfer step of transferring the visible image onto a recording medium, a fixing step of fixing the transferred image on the recording medium, and an image forming method characterized by having the above.

Images