Toner, toner storage unit, image forming apparatus, image forming method, and method for manufacturing toner

Abstract

To provide a toner that exhibits excellent low temperature fixability and achieves heat-resistant storage properties.SOLUTION: A toner has a toner base particle containing at least a binder resin, a coloring agent, and wax, and resin fine particles attached to the surface of the toner base particle. The toner has a glass-transition temperature of 44.0°C or more. When a void diameter on a cross section of the toner base particle observed by a scanning electron microscope (SEM) is defined as Φ(nm), one or less voids indicate Φ≥200, and after the toner is heated at a glass-transition temperature of the toner of -3.0°C, three or more voids indicate Φ≥200.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] In recent years, toners have been required to have small particle sizes and high-temperature offset resistance for high-quality output images, low-temperature fixing properties for energy saving, and heat-resistant storage properties to withstand high temperatures and humidity during storage and transportation after manufacturing. In particular, since power consumption during fixing accounts for a large portion of the power consumption in the image formation process, improving low-temperature fixing properties is extremely important.

[0003] To improve the low-temperature fixing properties of toner, it is necessary to use materials with a low melting point in the toner. However, toner manufactured using materials with a low melting point has poor heat resistance for storage, and there is a trade-off between low-temperature fixing properties and heat resistance for storage.

[0004] Therefore, in order to achieve both low-temperature fixability and heat-resistant storage, a method for producing composite resin particles has been proposed that includes a removal step to remove some or all of the resin from the resin microparticles after forming composite resin particles in which resin microparticles containing two types of resin as constituent components within the same particle are attached to the surface of the resin particles (see, for example, Patent Documents 1 to 3). [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] The present invention aims to provide a toner that exhibits excellent low-temperature fixing properties while also achieving heat resistance for storage. [Means for solving the problem]

[0006] The above problem is solved by the following configuration 1). 1) A toner in which resin fine particles are attached to the surface of toner matrix particles containing at least a binder resin, a colorant, and a wax, The aforementioned binder resin includes polyester resin, The aforementioned resin fine particles include a polymer obtained by homopolymerizing or copolymerizing vinyl monomers. The glass transition temperature of the toner is 44.0 °C or higher, when the void diameter in the cross-section of the toner base particles observed by a scanning electron microscope (SEM) is Φ (nm), the number of voids with Φ ≥ 200 is 1 or less, and at the glass transition temperature - 3.0 °C of the toner Assuming a heating rate of 130°C / min after heating the toner, the number of voids with Φ ≥ 200 is 3 or more. The toner is characterized by this.

Advantages of the Invention

[0007] According to the present invention, it is possible to provide a toner that exhibits excellent low-temperature fixing properties while also achieving heat-resistant storage properties.

Brief Description of the Drawings

[0008] [Figure 1] It is a schematic diagram showing an example of the surface state of toner base particles. [Figure 2] It is a schematic diagram showing an embodiment of a process cartridge. [Figure 3] It is a schematic diagram showing an example of an image forming apparatus according to the present invention.

Embodiments for Carrying Out the Invention

[0009] Hereinafter, the toner, toner container unit, image forming apparatus, and image forming method according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiments shown below, and can be changed within the range that those skilled in the art can conceive, such as other embodiments, additions, modifications, deletions, etc., and is included in the scope of the present invention as long as the functions and effects of the present invention are achieved in any aspect.

[0010] As described above, there is a demand for improving the low-temperature fixing property of toner. However, toner manufactured using a low melting point material has poor heat-resistant storage property, and there is a trade-off relationship between the low-temperature fixing property and the heat-resistant storage property. As described in Patent Documents 1 to 3 above, various technical developments have been made, but none of them, including the above technology, have satisfied the high level of low-temperature fixing property required in recent years. In the present invention, in order to solve such problems, by generating voids in the toner in the fixing device, the ductility is improved, and thus, it is possible to provide a toner that exhibits excellent low-temperature fixing property while also achieving heat-resistant storage property.

[0011] The present invention includes the following aspects. 1. A toner in which resin fine particles are attached to the surface of toner base particles containing at least a binder resin, a colorant, and a wax, where the glass transition temperature of the toner is 44.0 °C or higher, when the void diameter in the cross-section of the toner base particles observed by a scanning electron microscope (SEM) is Φ (nm), the number of voids with Φ ≥ 200 is 1 or less, and after heating the toner at the glass transition temperature of the toner - 3.0 °C, the number of voids with Φ ≥ 200 is 3 or more. A toner characterized by this. 2. The toner according to 1 above, characterized in that after heating the toner at the glass transition temperature of the toner - 3.0 °C, the number of voids with Φ ≥ 200 is 3 or more and 15 or less. 3. The toner according to 1 or 2 above, characterized in that after heating the toner at the glass transition temperature of the toner - 3.0 °C, the number of voids with 500 ≥ Φ ≥ 200 is 3 or more and 15 or less. [[ID=第十八]]4. The toner according to any one of 1 to 3 above, characterized in that the standard deviation of the distance between adjacent resin fine particles present on the surface of the toner base particles is less than 500 nm. 5. A toner storage unit characterized by storing the toner according to any one of 1 to 4 above. 6. An image forming apparatus characterized by having the toner storage unit according to 5 above. 7. An image forming method comprising: an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier; and a developing step of forming a toner image, which is a visible image, by developing the electrostatic latent image formed on the electrostatic latent image carrier using toner, wherein the toner is the toner described in any of 1 to 4 above.

[0012] <Toner> The toner of the present invention is characterized in that resin fine particles are attached to the surface of toner matrix particles containing at least a binder resin, a colorant, and a wax, the glass transition temperature of the toner is 44.0°C or higher, and when the void diameter in the cross-section of the toner matrix particles observed by a scanning electron microscope (SEM) is Φ (nm), there is one or fewer voids with Φ≧200, and after heating the toner at the glass transition temperature of -3.0°C, there are three or more voids with Φ≧200, and further, other components may be present as needed.

[0013] In conventional technologies, low-temperature fixability and heat-resistant storage are often at odds, and there is currently a need for alternative methods to improve low-temperature fixability. However, the toner of the present invention, with the above configuration, improves ductility by creating a difference in the number of voids before and after heating at the toner's glass transition temperature (Tg) of -3°C, thereby exhibiting excellent low-temperature fixability without affecting heat-resistant storage.

[0014] By heating to a certain temperature or higher, residual solvents such as ethyl acetate and water vaporize, creating voids within the toner. Setting this heating temperature to Tg-3.0°C allows for the reproduction of conditions close to the preheating temperature before use in the fuser. Furthermore, by setting the heating temperature to Tg-3.0°C, the creation of voids in the toner, which is related to the improvement in ductility, can be confirmed.

[0015] Toner containing voids from the moment of manufacture is vulnerable to mechanical stress, leading to various problems such as the toner being crushed by stress within the developing machine or adhering to equipment, causing image loss.

[0016] By warming the toner to a temperature of Tg-3.0°C within the fuser unit, that is, during preheating just before fixing, voids are created, resulting in a toner that is highly resistant to mechanical stress and exhibits excellent low-temperature fixing properties.

[0017] The toner of the present invention, when observed by a scanning electron microscope (SEM) before heating, has one or fewer voids with a void diameter of Φ (nm) in the cross-section of the toner matrix particles, where Φ is defined as Φ (nm). By satisfying this condition, a toner can be obtained that is highly resistant to mechanical stress, has excellent low-temperature fixation properties, and also has good heat resistance for storage.

[0018] Furthermore, the toner of the present invention has three or more voids with a diameter of Φ≧200 after heating the toner at a Tg of -3.0℃. By satisfying this condition, a toner that exhibits excellent low-temperature fixing properties without affecting heat resistance for storage can be obtained.

[0019] Furthermore, it is preferable that the toner of the present invention has 3 to 15 voids with a diameter of Φ≧200 after heating at Tg-3.0℃. Satisfying this condition ensures that the toner has appropriate spreadability without degrading its blocking resistance, while also satisfying low-temperature fixation and blocking resistance.

[0020] Furthermore, it is even more preferable that the toner of the present invention has 3 to 15 voids with a diameter of 500 ≥ Φ ≥ 200 after heating at Tg -3.0°C. Satisfying this condition further improves the spreadability of the toner and does not worsen its blocking resistance. By keeping the number of voids with a diameter of 500 ≥ Φ ≥ 200 in the range of 3 to 15, low-temperature fixation and blocking resistance can be sufficiently satisfied.

[0021] In the present invention, it is preferable that the standard deviation of the distance between adjacent resin fine particles on the surface of the toner matrix particles is less than 500 nm. By satisfying this condition, the amount of external additive released can be optimized, suppressing the occurrence of abnormal images such as medaka and filming, while simultaneously achieving a high level of both low-temperature fixation and excellent cleaning performance due to low adhesion.

[0022] <Void> In the toner of the present invention, after heating to a Tg of -3.0°C, voids are formed inside the toner matrix particles. Voids are identified when ruthenium-stained toner matrix particles are observed using a scanning electron microscope (SEM), and the secondary electron image and backscattered electron image are compared. Voids are identified as areas that appear black only in the secondary electron image.

[0023] <Method for measuring void diameter Φ> Using image processing software (ImageJ), the outer circumference of the void is measured, and the diameter of a perfect circle having the same circumference as the measured outer circumference is defined as the void diameter Φ. The imaging conditions for the scanning electron microscope (SEM) are shown below.

[0024] [Shooting conditions] • Scanning electron microscope: SU-8230 (manufactured by Hitachi High-Technologies Corporation) • Magnification: 60,000x • Image type: SE(L): Secondary electrons, BSE(backscattered electrons) • Acceleration voltage: 3.0kV ·Acceleration current: 1.0μA • Probe current: Normal • Focus mode: UHR WD: 8.0mm

[0025] In the toner of the present invention, in order to reduce the number of voids with Φ≧200 to one or less, and to reduce the number of voids with Φ≧200 to three or more after heating the toner at Tg-3.0℃, means of reducing the primary particle size by mechanical or chemical action can be used. Specific examples of the former include, for example, applying shear, and the latter include adjusting the amount of surfactant or amine. Furthermore, the following conditions are required to heat the toner to Tg-3.0℃. Equipment used: Microscope cooling and heating stage (manufactured by Japan High-Tech Co., Ltd.) Example heating rate: 130°C / min Holding time: 0min Cooling temperature: Up to room temperature

[0026] Furthermore, the glass transition temperature (Tg) of the toner of the present invention must be 44.0°C or higher. If the Tg is below 44.0°C, the heat resistance for storage will deteriorate.

[0027] <Resin fine particles> The aforementioned resin fine particles are attached to the surface of the toner matrix particles. The standard deviation of the distance between adjacent resin fine particles on the surface of the toner matrix particles is less than 500 nm, preferably 250 nm or less, and more preferably 100 nm or less. The lower limit of the standard deviation is preferably 10 nm or more. A standard deviation of less than 500 nm allows for a high level of both low-temperature fixability and heat resistance during storage, while maintaining good cleaning performance and suppressing the generation of abnormal images due to filming. The average distance between the resin fine particles is preferably 10 nm to 500 nm, and more preferably 20 nm to 250 nm. Methods to ensure that the standard deviation of the distance between adjacent resin microparticles on the surface of the toner matrix particles is less than 500 nm include, for example, designing the formulation so that the coverage rate of resin microparticles on the target toner particle size is 90% or more, and adding the resin microparticles during the emulsification process to densely adhere the resin microparticles to the toner surface, or adjusting the average circularity of the toner to efficiently adhere the resin microparticles and thereby reduce the distance between resin microparticles.

[0028] In this invention, the distance between adjacent resin microparticles is the distance between the centers of one resin microparticle and the center of the other resin microparticle. The center of the resin microparticle is the center point of the image obtained by observing the resin microparticle with a scanning electron microscope (SEM). The surface of the toner matrix particles is not flat but slightly rounded (curved). Therefore, the distance between the resin microparticles is not the distance between resin microparticles on the surface of the toner matrix particles, but rather the shortest distance between resin microparticles in an image of the resin microparticles on the surface of the toner matrix particles taken with a scanning electron microscope (SEM).

[0029] Here, Figure 1 is a schematic diagram showing an example of the surface state of toner matrix particles. Resin microparticles 3 are attached to the surface of the toner matrix particles 4. The resin microparticles 3 consist of a core resin (b2) 2 and a shell resin (b1) 1, which will be described later. C1 and C2 indicate the centers of the resin microparticles 3. M indicates the volume-average primary particle size of the resin microparticles 3. L indicates the distance between adjacent resin microparticles 3.

[0030] <Measurement of distance between resin microparticles> As described below, external additives are removed as much as possible by ultrasonic treatment to release them, bringing the material closer to the toner matrix particles, and the average value and standard deviation of the distance between resin microparticles are calculated.

[0031] -Method for releasing external additives- [1] Add 50 ml of a 5% by mass aqueous solution containing a surfactant (product name Neugen 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 side to side. Then, stir with a ball mill for 30 minutes to allow the toner to blend into the dispersion solution. [2] Then, an ultrasonic homogenizer (product name homogenizer, model VCX750, CV33, manufactured by SONICS&MATERIALS Co., Ltd.) is used to apply ultrasonic energy for 60 minutes at an output of 40W. -Ultrasonic Conditions- • Vibration time: 60 minutes continuous ·Amplitude: 40W ·Vibration start temperature: 23±1.5℃ ·Temperature during vibration: 23±1.5℃ [3](1) The obtained dispersion is filtered by suction using filter paper (product name: Qualitative filter paper (No. 2, 110 mm), manufactured by Advantec Toyo Co., Ltd.), washed twice again with deionized water and filtered to remove the freed additives, and then the toner particles are dried. (2) Observe the toner obtained in (1) using a scanning electron microscope (SEM). First, observe the backscattered electron image to detect Si-containing additives and fillers. (3) The image from (1) is binarized using image processing software (ImageJ) to remove the external additive and filler. Next, a secondary electron image is observed at the same position as in (1). Since resin microparticles are not observed in the backscattered electron image but only in the secondary electron image, they are compared with the image obtained in (3), and the microparticles present in the parts other than the remaining external additive and filler (the parts other than those excluded in (3)) are identified as resin microparticles. The distance between the resin microparticles (the distance between the centers of the particles) is then measured using the aforementioned image processing software. This measurement is performed on 100 binarized images (one toner particle per image), and the average value is taken as the average distance between resin microparticles. The standard deviation of the distance between resin microparticles is calculated using the following formula, where x is the interparticle distance.

[0032]

number

[0033] [Shooting conditions] • Scanning electron microscope: SU-8230 (manufactured by Hitachi High-Technologies Corporation) • Magnification: 35,000x • Image type: SE(L): Secondary electrons, BSE(backscattered electrons) • Acceleration voltage: 2.0kV ·Acceleration current: 1.0μA • Probe current: Normal • Focus mode: UHR WD: 8.0mm

[0034] The volume-average primary particle diameter of the resin fine particles is preferably 5 nm to 100 nm, and more preferably 10 nm to 50 nm. When the volume-average primary particle diameter is 5 nm to 100 nm, the low-temperature fixation performance is good. The volume-average primary particle diameter can be measured, for example, by scanning electron microscope (SEM) imaging.

[0035] The resin fine particles (hereinafter sometimes also 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 even more preferably contain vinyl units consisting of resin (b1) and resin (b2). 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.

[0036] Examples of the vinyl monomers 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 Examples of aliphatic vinyl hydrocarbons include alkenes and alkadienes. Examples of the aforementioned alkenes include ethylene, propylene, and α-olefins. Examples of the aforementioned alkadienes include butadiene, isoprene, 1,4-pentadiene, 1,6-hexadiene, and 1,7-octadiene.

[0037] (1-2) Alicyclic vinyl hydrocarbons Examples of alicyclic vinyl hydrocarbons include mono- or di-cycloalkenes and alkadienes, with specific examples including (di)cyclopentadiene and terpenes.

[0038] (1-3) Aromatic vinyl hydrocarbons Examples of aromatic vinyl hydrocarbons include styrene or its hydrocarbyl (alkyl, cycloalkyl, aralkyl, and / or alkenyl) substituted derivatives, specifically α-methylstyrene, 2,4-dimethylstyrene, and vinylnaphthalene.

[0039] (2) Carboxyl group-containing vinyl monomers and salts thereof Examples of the carboxyl group-containing vinyl monomers and their salts include unsaturated monocarboxylic acids (salts), unsaturated dicarboxylic acids (salts), and their anhydrides (salts), and their monoalkyl (1-24 carbon atoms) esters or salts thereof. Specifically, examples include (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, carboxyl group-containing vinyl monomers such as cinnamic acid, and metal salts thereof.

[0040] In this invention, "(salt)" means an acid or a salt thereof. For example, an unsaturated monocarboxylic acid (salt) with 3 to 30 carbon atoms refers to an unsaturated monocarboxylic acid or its salt. In this invention, "(meth)acrylic" means methacrylic acid or acrylic acid. In this invention, "(meth)acryloyl" means methacryloyl or acryloyl. In this invention, "(meth)acrylate" means methacrylate or acrylate.

[0041] (3) Sulfonic acid group-containing vinyl monomers, vinyl sulfate monoesters, and salts thereof Examples of the sulfonic acid group-containing vinyl monomers, vinyl sulfate monoesters, and salts thereof include C2-C14 alkene sulfonic acid (salt), C2-C24 alkyl sulfonic acid (salt), sulfo(hydroxy)alkyl-(meth)acrylate (salt), or (meth)acrylamide (salt), alkylallyl sulfosuccinate (salt), and so on. Specifically, examples of alkene sulfonic acids having 2 to 14 carbon atoms include vinyl sulfonic acid (salt), examples of alkyl sulfonic acids having 2 to 24 carbon atoms include α-methylstyrene sulfonic acid (salt), and examples of sulfo(hydroxy)alkyl-(meth)acrylate (salt) or (meth)acrylamide (salt) include sulfopropyl (meth)acrylate (salt), sulfate ester (salt), or sulfonic acid group-containing vinyl monomer (salt).

[0042] (4) Phosphate group-containing vinyl monomers and their salts Examples of phosphate-containing vinyl monomers and their salts include (meth)acryloyloxyalkyl (1-24 carbon atoms) phosphate monoester (salt) and (meth)acryloyloxyalkyl (1-24 carbon atoms) phosphonic acid (salt). Specific examples of the (meth)acryloyloxyalkyl (1-24 carbon atoms) phosphate monoester (salt) mentioned above include 2-hydroxyethyl (meth)acryloyl phosphate (salt) and phenyl-2-acryloyloxyethyl phosphate (salt). Specific examples of the (meth)acryloyloxyalkyl (1-24 carbon atoms) phosphonic acid (salt) mentioned above include 2-acryloyloxyethylphosphonic acid (salt).

[0043] Examples of the salts in (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.

[0044] (5) Hydroxyl group-containing vinyl monomer Examples of the hydroxyl group-containing vinyl monomers include hydroxystyrene, N-methylol(meth)acrylamide, hydroxyethyl(meth)acrylate, hydroxypropyl(meth)acrylate, polyethylene glycol mono(meth)acrylate, (meth)allyl alcohol, clotyl alcohol, isoclotyl alcohol, 1-buten-3-ol, 2-buten-1-ol, 2-buten-1,4-diol, propargyl alcohol, 2-hydroxyethylpropenyl ether, and sucrose allyl ether.

[0045] (6) Nitrogen-containing vinyl monomer Examples of the nitrogen-containing vinyl monomers 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 vinyl monomers containing quaternary ammonium cation groups include dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, dimethylaminoethyl (meth)acrylamide, diethylaminoethyl (meth)acrylamide, and quaternized vinyl monomers containing tertiary amine groups such as diallylamine (quaternized using quaternizing agents such as methyl chloride, dimethyl sulfate, benzyl chloride, and dimethyl carbonate). (6-5) Examples of nitro group-containing vinyl monomers include nitrostyrene.

[0046] (7) Epoxy group-containing vinyl monomer Examples of the epoxy group-containing vinyl monomers include glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and p-vinylphenylphenyl oxide.

[0047] (8) Halogen-containing vinyl monomers Examples of the halogen-containing vinyl monomers include vinyl chloride, vinyl bromide, vinylidene chloride, allyl chloride, chlorostyrene, bromostyrene, dichlorostyrene, chloromethylstyrene, tetrafluorostyrene, and chloroprene.

[0048] (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, and alkyl (meth)acrylate having an alkyl group with 1 to 50 carbon atoms [methyl (meth )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 (the two alkyl groups are linear, branched, or alicyclic groups with 2 to 8 carbon atoms), dialkyl Examples include maleates (the two alkyl groups are linear, branched, or alicyclic groups with 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 molar adduct (meth)acrylate, lauryl alcohol ethylene oxide 30 molar adduct (meth)acrylate, etc.], and 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.]. Examples of vinyl (thio) ethers include vinyl methyl ether. Examples of vinyl ketones include vinyl methyl ketone.

[0049] (10) Other vinyl monomers Other vinyl monomers include, for example, tetrafluoroethylene, fluoroacrylate, isocyanatoethyl (meth)acrylate, and m-isopropenyl-α,α-dimethylbenzyl isocyanate.

[0050] For the synthesis of resin (b1), one of the vinyl monomers (1) to (10) above may be used alone, or two or more may be used in combination. As for the resin (b1), styrene-(meth)acrylic acid ester copolymer and (meth)acrylic acid ester copolymer are preferred from the viewpoint of low-temperature fixation, and styrene-(meth)acrylic acid ester copolymer is more preferred. The presence of a carboxylic acid in resin (b1) imparts an acid value to the resin, making it easier for resin microparticles (B) to adhere to the surface of toner particles and form toner particles.

[0051] The vinyl monomer used in resin (b2) is the same as that used in resin (b1). For the synthesis of resin (b2), one of the vinyl monomers (1) to (10) listed in resin (b1) above may be used alone, or two or more may be used in combination. As for the resin (b2), styrene-(meth)acrylic acid ester copolymer and (meth)acrylic acid ester copolymer are preferred from the viewpoint of low-temperature fixation, and styrene-(meth)acrylic acid ester copolymer is more preferred.

[0052] The loss modulus G'' of the viscoelastic properties of resin (b1) at a frequency of 1 Hz and 100°C 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 resin (b2) at a frequency of 1 Hz and 100°C 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. If the loss modulus G'' of the viscoelastic properties is within this range, resin fine particles (B) containing resin (b1) and resin (b2) as constituent components within the same particle are likely to form toner particles that adhere to the surface of toner particles.

[0053] 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 type and proportion of constituent monomers, as well as by the polymerization conditions (type and amount of initiator and chain transfer agent, and reaction temperature, etc.). Specifically, by using a composition such as the following, it becomes possible to adjust each G'' to the aforementioned range.

[0054] (1) 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) are set such that 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. The glass transition temperature (Tg) calculated from the constituent monomers is a value that can be calculated using 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 individual homopolymers, as shown by the following formula. 1 / Tg=W1 / Tg1+W2 / Tg2++Wn / Tgn [In the formula, Tg is the glass transition temperature of the copolymer (expressed in absolute temperature), Tg1, Tg2...Tgn are the glass transition temperatures of the homopolymers of each monomer component (expressed in absolute temperature), and W1, W2...Wn represent the weight fraction of each monomer component.]

[0055] (2) For the calculated acid value (AV1) of resin (b1) and the calculated acid value (AV2) of resin (b2), (AV1) is preferably 75 mg KOH / g to 400 mg KOH / g, more preferably 150 mg KOH / g to 300 mg KOH / g, and (AV2) is 0 mg KOH / g to 50 mg KOH / g, more preferably 0 mg KOH / g to 20 mg KOH / g, and most preferably 0 mg KOH / g. The calculated acid value is the theoretical acid value calculated from the molar amount of acidic groups contained in the constituent monomers and the total weight of the constituent monomers.

[0056] Examples of constituent monomers that satisfy conditions (1) and (2) include resin (b1), which preferably contains 10% to 80% by mass, more preferably 30% to 60% by mass of styrene as constituent monomers, and preferably a total of 10% to 60% by mass, more preferably 30% to 50% by mass of methacrylic acid and / or acrylic acid. Furthermore, regarding resin (b2), for example, a resin may be used in which, based on the total mass of resin (b2), styrene is preferably contained in a total of 10% to 100% by mass, more preferably 30% to 90% by mass, as a constituent monomer, and methacrylic acid and / or acrylic acid are preferably contained in a total of 0% to 7.5% by mass, more preferably 0% to 2.5% by mass, based on the total mass of resin (b2).

[0057] (3) Adjust the polymerization conditions (type and amount of initiator and chain transfer agent, and reaction temperature, etc.). Specifically, for the number average molecular weights (Mn1) and (Mn2) of resin (b1) and 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.

[0058] The loss modulus G'' of the viscoelastic properties in this invention is measured, for example, using the following viscoelasticity measuring device. • Equipment: ARES-24A (manufactured by Rheometric Corporation) • Jig: 25mm parallel plate • Frequency: 1Hz • Distortion rate: 10% • Heating rate: 5°C / min

[0059] The acid value (AVb1) of the resin (b1) is preferably 75 mg KOH / g to 400 mg KOH / g, and more preferably 150 mg KOH / g to 300 mg KOH / g. If the acid value is within the above range, resin fine particles (B) containing vinyl-based units that include resin (b1) and resin (b2) as constituent components within the same particle are likely to form particles that adhere to the surface of the toner. The resin (b1) having an acid value within the above range is a resin that contains methacrylic acid and / or acrylic acid in an amount of 10% to 60% by mass, more preferably 30% to 50% by mass, based on the total mass of the resin (b1).

[0060] From the viewpoint of low-temperature fixation, the acid value (AVb2) of the resin (b2) is preferably 0 mg KOH / g to 50 mg KOH / g, more preferably 0 mg KOH / g to 20 mg KOH / g, and even more preferably 0 mg KOH / g. Resins (b2) with an acid value in this range are resins that contain methacrylic acid and / or acrylic acid in a total amount of 0% to 7.5% by mass, 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 specified in JIS K0070:1992.

[0061] The glass transition temperature of resin (b1) is preferably higher than that of resin (b2), more preferably 10°C or more higher, and even more preferably 20°C or more higher. Within this range, the resin fine particles (B) offer an excellent balance between the ease with which toner particles are formed when they adhere to the surface of the toner and the low-temperature fixation properties of the toner particles according to the present invention.

[0062] The glass transition temperature of the resin (b1) (hereinafter sometimes abbreviated as Tg) is preferably 0°C to 150°C, more preferably 50°C to 100°C. If the glass transition temperature is 0°C or higher, the heat-resistant storage stability can be improved, and if it is 150°C or lower, the inhibition to low-temperature fixing property is small. The Tg of the resin (b2) is preferably -30°C to 100°C, more preferably 0°C to 80°C, and still more preferably 30°C to 60°C. If the glass transition temperature is -30°C or higher, the heat-resistant storage stability can be improved, and if it is 100°C or lower, the inhibition to low-temperature fixing property is small.

[0063] The Tg of the resin (b1) and the resin (b2) is measured by the method (DSC) specified in ASTM D3418-82 using "DSC20, SSC / 580" [manufactured by Seiko Epson Corporation].

[0064] The solubility parameter of the resin (b1) (hereinafter sometimes abbreviated as SP value) is 9 (cal / cm 3 , 3 ) 1 / 2 ~13 (cal / cm 3 ) 1 / 2 is preferable, 9.5 (cal / cm 3 ) 1 / 2 ~12.5 (cal / cm 3 ) 1 / 2 is more preferable, and 10.5 (cal / cm 3 ) 1 / 2 ~11.5 (cal / cm 3 ) 1 / 2 is still more preferable. The SP value of the resin (b1) can be adjusted by changing the types of the constituent monomers and their composition ratios. The SP value of the resin (b2) is 8.5 (cal / cm 3 ) 1 / 2 ~12.5 (cal / cm 3 ) 1 / 2 is preferable, 9 (cal / cm 3 ) 1 / 2 ~12 (cal / cm 3 ) 1 / 2More preferably, 10 (cal / cm³) 3 ) 1 / 2 ~11 (cal / cm 3 ) 1 / 2 That is even more preferable. The SP value of resin (b2) can be adjusted by changing the types and proportions of the constituent monomers.

[0065] The SP value in this invention is calculated by the method of Fedors [Polym.Eng.Sci.14(2)152,(1974)].

[0066] From the viewpoint of the Tg of resin (b1) and copolymerizability with other monomers, it is preferable that resin (b1) contains 10% to 80% by mass of styrene as a constituent monomer, and more preferably 30% to 60% by mass, based on the total mass of resin (b1). From the viewpoint of the Tg of resin (b2) and copolymerizability with other vinyl monomers, it is preferable that resin (b2) contains 10% to 100% by mass of styrene as a constituent monomer, and more preferably 30% to 90% by mass, based on the total mass of resin (b2).

[0067] 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. If the number-average molecular weight is 2,000 or higher, the heat-resistant storage properties are improved, and if it is 2,000,000 or lower, there is less inhibition of the toner's low-temperature fixation properties.

[0068] The weight-average molecular weight (Mw) of resin (b1) is preferably greater than that of resin (b2), more preferably 1.5 times greater than that of resin (b2), and even more preferably 2.0 times greater than that of resin (b2). Within this range, an excellent balance is achieved between the ease of toner particle formation and low-temperature fixation.

[0069] The weight-average molecular weight (Mw) of resin (b1) is preferably 20,000 to 20,000,000, and more preferably 200,000 to 2,000,000. If the weight-average molecular weight is 20,000 or higher, the heat-resistant storage properties are improved, and if it is 20,000,000 or lower, there is less inhibition of low-temperature fixation properties.

[0070] 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. If Mn is 1,000 or higher, the heat resistance of the toner is improved, and if it is 1,000,000 or lower, there is less inhibition of the toner's low-temperature fixation.

[0071] 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. If Mw is 10,000 or higher, the heat resistance of the toner is improved, and if it is 10,000,000 or lower, there is less inhibition of the toner's low-temperature fixation.

[0072] Among these, it is preferable 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 that "(b1)'s Mw" > "(b2)'s Mw".

[0073] In this invention, Mn and Mw can be measured using gel permeation chromatography (GPC) under the following conditions. • Device (example): "HLC-8120" [Manufactured by Tosoh Corporation] • Column (example): "TSK GEL GMH6" [manufactured by Tosoh Corporation] 2 pieces ·Measurement temperature: 40℃ • Sample solution: 0.25 wt% tetrahydrofuran solution (insoluble matter filtered out using a glass filter) ·Solution injection volume: 100μl • Detection device: Refractive index detector • Reference material: Standard polystyrene (TSKstandard POLYSTYRENE) 12 samples (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]

[0074] 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. If the mass ratio of resin (b1) to resin (b2) is 5 / 95 or higher, the toner has excellent heat resistance for storage, and if the mass ratio of resin (b1) to resin (b2) is 95 / 5 or lower, the resin fine particles (B) are more likely to adhere to the surface of toner particles, forming toner particles.

[0075] Known manufacturing methods can be used to produce resin microparticles (B), including, for example, the following manufacturing 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 seed polymerization of constituent monomers of resin (b1) using fine particles of resin (b2) in an aqueous dispersion as seeds. (III) A method for obtaining an aqueous dispersion of resin fine particles by emulsifying a mixture of resin (b1) and resin (b2) in an aqueous medium. (IV) A method for obtaining an aqueous dispersion of resin fine particles by emulsifying a mixture of resin (b1) and constituent monomers of resin (b2) in an aqueous medium, and then polymerizing the constituent monomers of resin (b2). (V) A method of obtaining an aqueous dispersion of resin fine particles by emulsifying a mixture of resin (b2) and constituent monomers of resin (b1) in an aqueous medium, and then polymerizing the constituent monomers of resin (b1).

[0076] The fact that resin microparticles (B) contain shell resin (b1) and core resin (b2) as constituent components within the same particle can be confirmed by observing elemental mapping images of the cross-section of resin microparticles (B) using a known surface elemental analyzer (TOF-SIMSEDX-SEM, etc.), and by observing electron microscope images of the cross-section of resin microparticles (B) stained with dyes corresponding to the functional groups contained in resin (b1) and resin (b2). Furthermore, the resin fine particles obtained by this method may be a mixture containing resin fine particles (B) that have resin (b1) and resin (b2) as constituent components within the same particle, as well as resin fine particles that have only resin (b1) as a constituent resin component and resin fine particles that have only resin (b2) as a constituent resin component. In the compounding process described later, the mixture may be used as is, or only the resin fine particles (B) may be isolated and used.

[0077] Specific examples of (I) include a method in which the constituent monomers of (b1) are polymerized dropwise to produce an aqueous dispersion of resin fine particles 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.

[0078] Specific examples of (II) include a method in which the constituent monomers of (b2) are polymerized dropwise to produce an aqueous dispersion of resin fine particles containing (b2), and then the constituent monomers of (b1) are 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 monomers of (b1) are polymerized using this as a seed.

[0079] Specific examples of (III) include a method in which solutions or melts of (b1) and (b2) prepared in advance by solution polymerization, etc., are mixed, and then the mixture is emulsified and dispersed in an aqueous medium.

[0080] Specific examples of (IV) include a method in which (b1), which has been produced in advance by solution polymerization, 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 constituent monomers of (b2), the mixture is emulsified and dispersed in an aqueous medium, and then the constituent monomers of (b2) are polymerized.

[0081] Specific examples of (V) include a method in which (b2), which has been produced in advance by solution polymerization, 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 (a2) 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.

[0082] In the present invention, any of the above manufacturing methods (I) to (V) is preferred.

[0083] The resin fine particles (B) are preferably used as an aqueous dispersion. The aqueous dispersion (aqueous medium) used is not particularly limited as long as it is soluble in water, and can be appropriately selected according to the purpose. Examples include surfactants (D), buffers, and protective colloids. These may be used individually or in combination of two or more. The aqueous medium used in the aforementioned aqueous dispersion can be any liquid that requires water; there are no particular restrictions on its use, and examples include aqueous solutions containing water.

[0084] Examples of the surfactant (D) include nonionic surfactants (D1), anionic surfactants (D2), cationic surfactants (D3), amphoteric surfactants (D4), and other emulsifying dispersants (D5).

[0085] Examples of the nonionic surfactant (D1) include AO (alkylene oxide)-added nonionic surfactants and polyhydric alcohol-type nonionic surfactants. Examples of the AO-addition type nonionic surfactant include EO adducts of aliphatic alcohols having 10 to 20 carbon atoms, EO adducts of phenols, EO (ethylene oxide) adducts of nonylphenols, EO adducts of alkylamines having 8 to 22 carbon atoms, and EO adducts of poly(oxypropylene) glycols. Examples of the polyhydric alcohol-type nonionic surfactant include polyhydric (3-8 or more hydric) alcohol (2-30 carbon atoms) fatty acid (8-24 carbon atoms) esters (e.g., glycerin monostearate, glycerin monooleate, sorbitan monolaurate, sorbitan monooleate, etc.), alkyl (4-24 carbon atoms) poly(degree of polymerization 1-10) glycosides, and the like.

[0086] Examples of the anionic surfactant (D2) include ether carboxylic acids or salts thereof having a hydrocarbon group having 8 to 24 carbon atoms, sulfate esters or ether sulfate esters and salts thereof having a hydrocarbon group having 8 to 24 carbon atoms, sulfonates having a hydrocarbon group having 8 to 24 carbon atoms, sulfosuccinates having one or two hydrocarbon groups having 8 to 24 carbon atoms, phosphate esters or ether phosphate esters and salts thereof having a hydrocarbon group having 8 to 24 carbon atoms, fatty acid salts having a hydrocarbon group having 8 to 24 carbon atoms, and acylated amino acid salts having a hydrocarbon group having 8 to 24 carbon atoms. Examples of ether carboxylic acids or salts thereof having hydrocarbon groups with 8 to 24 carbon atoms include sodium lauryl ether acetate and sodium (poly)oxyethylene (additional moles 1 to 100) lauryl ether acetate. Examples of sulfate esters or ether sulfate esters having hydrocarbon groups with 8 to 24 carbon atoms and their salts include sodium lauryl sulfate, (poly)oxyethylene (1 to 100 moles added) sodium lauryl sulfate, (poly)oxyethylene (1 to 100 moles added) triethanolamine lauryl sulfate, and (poly)oxyethylene (1 to 100 moles added) coconut oil fatty acid monoethanolamide sulfate sodium. Examples of sulfonates having hydrocarbon groups with 8 to 24 carbon atoms include sodium dodecylbenzenesulfonate. Examples of phosphate esters or ether phosphate esters having hydrocarbon groups with 8 to 24 carbon atoms, and their salts, include sodium lauryl phosphate and sodium (poly)oxyethylene (additional moles 1 to 100) lauryl ether phosphate. Examples of fatty acid salts having hydrocarbon groups with 8 to 24 carbon atoms include sodium laurate and triethanolamine laurate. Examples of acylated amino acid salts having hydrocarbon groups with 8 to 24 carbon atoms include sodium methyl taurate, sodium sarcosinate, triethanolamine sarcosinate, triethanolamine acyl-L-glutamate, sodium acyl-L-glutamate, and sodium lauroyl methyl-β-alanine.

[0087] Examples of the cationic surfactant (D3) include quaternary ammonium salts and amine salts. Examples of the quaternary ammonium salt type include stearyltrimethylammonium chloride, behenyltrimethylammonium chloride, distearyldimethylammonium chloride, and aminopropylethyldimethylammonium ethyl sulfate. Examples of the amine salt type include diethylaminoethyl stearate lactate, dilaurylamine hydrochloride, and oleylamine lactate.

[0088] Examples of amphoteric surfactants (D4) include betaine-type amphoteric surfactants and amino acid-type amphoteric surfactants. Examples of the betaine-type amphoteric surfactants include coconut oil fatty acid amidopropyl dimethylaminoacetic acid betaine, lauryl dimethylaminoacetic acid betaine, 2-alkyl-N-carboxymethyl-N-hydroxyethylimidazolinium betaine, and lauryl hydroxysulfobetaine. Examples of amino acid-type amphoteric surfactants include sodium β-laurylaminopropionate.

[0089] Other emulsifying and dispersing agents (D5) include, for example, reactive surfactants. The reactive activator is not particularly limited as long as it has radical reactivity and can be appropriately selected according to the purpose. For example, Adekarya Soap (registered trademark) SE-10N, SR-10, SR-20, SR-30, ER-20, ER-30 (all manufactured by ADEKA Corporation), Aqualon (registered trademark) HS-10, KH-05, KH-10, KH-1025 (all manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), Eleminor (registered trademark) JS-20 (manufactured by Sanyo Chemical Industries, Ltd.), Latemul (registered trademark) D-104, PD-420, PD-430 (all, Examples include Kao Corporation's Ionet (registered trademark) MO-200 (manufactured by Sanyo Chemical Industries, Ltd.), polyvinyl alcohol, starch or its derivatives, cellulose derivatives such as carboxymethylcellulose, methylcellulose and hydroxyethylcellulose, and carboxyl group-containing (co)polymers such as sodium polyacrylate, and emulsifying dispersants having urethane groups or ester groups as described in U.S. Patent No. 5,906,704 (for example, polycaprolactone polyol and polyetherdiol linked by polyisocyanate).

[0090] As for the surfactant (D), (D1), (D2), (D5), and combinations thereof are preferred from the viewpoint of stabilizing oil droplets during emulsification and dispersion, obtaining the desired shape, and sharpening the particle size distribution, with combinations of (D1) and (D5) and combinations of (D2) and (D5) being more preferred.

[0091] Examples of the buffering agent include sodium acetate, sodium citrate, sodium bicarbonate, and the like. Examples of the protective colloid include water-soluble cellulose compounds and alkali metal salts of polymethacrylic acid.

[0092] The resin fine particles (B) may contain, in addition to the shell resin (b1) and core resin (b2), other resin components, initiators (and their residues), chain transfer agents, antioxidants, plasticizers, preservatives, reducing agents, organic solvents, and the like.

[0093] Other resin components include vinyl resins other than those used in the shell resin (b1) and core resin (b2), polyurethane resins, epoxy resins, polyester resins, polyamide resins, polyimide resins, silicon resins, phenolic resins, melamine resins, urea resins, aniline resins, ionomer resins, and polycarbonate resins.

[0094] Examples of the initiator (and its residue) include known radical polymerization initiators, specifically persulfate initiators such as potassium persulfate and ammonium persulfate; azo initiators such as azobisisobutyronitrile; organic peroxides such as benzoyl peroxide, cumene hydroperoxide, tert-butyl hydroperoxide, tert-butyl peroxyisopropyl monocarbonate, and tert-butyl peroxybenzoate; and hydrogen peroxide.

[0095] Examples of chain transfer agents include n-dodecyl mercaptan, tert-dodecyl mercaptan, n-butyl mercaptan, 2-ethylhexyl thioglycolate, 2-mercaptoethanol, β-mercaptopropionic acid, and α-methylstyrene dimer.

[0096] Examples of antioxidants include phenol compounds, paraphenylenediamine, hydroquinone, organosulfur compounds, and organophosphorus compounds.

[0097] Examples of phenolic compounds include 2,6-di-t-butyl-p-cresol, butylated hydroxyanisole, 2,6-di-t-butyl-4-ethylphenol, stearyl-β-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 2,2′-methylene-bis-(4-methyl-6-t-butylphenol), 2,2′-methylene-bis-(4-ethyl-6-t-butylphenol), 4,4′-thiobis-(3-methyl-6-t-butylphenol), and 4,4′-butylidenebis-(3-methyl-6-t-butylphenol). Examples include tris(6-t-butylphenol), 1,1,3-tris-(2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tetrakis-[methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate]methane, bis[3,3′-bis(4′-hydroxy-3′-t-butylphenyl)butyric acid]glycol ester, and tocopherol.

[0098] Examples of paraphenylenediamines include N-phenyl-N′-isopropyl-p-phenylenediamine, N,N′-di-sec-butyl-p-phenylenediamine, N-phenyl-N-sec-butyl-p-phenylenediamine, N,N′-di-isopropyl-p-phenylenediamine, and N,N′-dimethyl-N,N′-di-t-butyl-p-phenylenediamine.

[0099] Examples of hydroquinones include 2,5-di-t-octylhydroquinone, 2,6-didodecylhydroquinone, 2-dodecylhydroquinone, 2-dodecyl-5-chlorohydroquinone, 2-t-octyl-5-methylhydroquinone, and 2-(2-octadecenyl)-5-methylhydroquinone.

[0100] Examples of organosulfur compounds include dilauryl-3,3′-thiodipropionate, distearyl-3,3′-thiodipropionate, and ditetradecyl-3,3′-thiodipropionate.

[0101] Examples of organophosphorus compounds include triphenylphosphine, tri(nonylphenyl)phosphine, tri(dinonylphenyl)phosphine, tricresylphosphine, and tri(2,4-dibutylphenoxy)phosphine.

[0102] Examples of the aforementioned plasticizers include phthalate esters, aliphatic dibasic acid esters, trimellitic acid esters, phosphate esters, and fatty acid esters. Examples of phthalate esters include dibutyl phthalate, dioctyl phthalate, butylbenzyl phthalate, and diisodecyl phthalate. Examples of aliphatic dibasic acid esters include di-2-ethylhexyl adipate and 2-ethylhexyl sebacate. Examples of trimellitic acid esters include tri-2-ethylhexyl trimellitic acid and trioctyl trimellitic acid. Examples of phosphate esters include triethyl phosphate, tri-2-ethylhexyl phosphate, and tricresyl phosphate. Examples of fatty acid esters include butyl oleate.

[0103] Examples of the aforementioned preservatives include organic nitrogen sulfur compound preservatives and organic sulfur halide preservatives.

[0104] Examples of reducing agents include reducing organic compounds such as ascorbic acid, tartaric acid, citric acid, glucose, and formaldehyde sulfoxylate metal salts; and reducing inorganic compounds such as sodium thiosulfate, sodium sulfite, sodium bisulfite, and sodium metabisulfite.

[0105] Examples of organic solvents include ketone solvents such as acetone and methyl ethyl ketone (hereinafter abbreviated as MEK); ester solvents such as ethyl acetate and γ-butyrolactone; ether solvents such as THF (tetrahydrofuran); amide solvents such as N,N-dimethylformamide, N,N-dimethylacetamide, N-methyl-2-pyrrolidone, and N-methylcaprolactam; alcohol solvents such as isopropyl alcohol; and aromatic hydrocarbon solvents such as toluene and xylene.

[0106] The resin fine particle content is preferably 0.2% to 5% by mass relative to the toner. When the sum of resin (b1) and resin (b2) is within this range, both low-temperature fixability and heat-resistant storage properties are improved. If the content is 0.2% by mass or more relative to the toner, the problem of poor heat-resistant storage properties can be prevented, and if it is 5% by mass or less, the problem of reduced low-temperature fixability can be prevented.

[0107] <Toner matrix particles> The aforementioned toner matrix particles (hereinafter sometimes referred to as "toner matrix" or "matrix particles") contain a binder resin, a colorant, and a wax, and further contain other components as necessary.

[0108] <<Binding resin>> The binder resin is not particularly limited and can be appropriately selected depending on the purpose. Examples include polyester resin, styrene-acrylic resin, polyol resin, vinyl resin, polyurethane resin, epoxy resin, polyamide resin, polyimide resin, silicon resin, phenol resin, melamine resin, urea resin, aniline resin, ionomer resin, and polycarbonate resin. These may be used individually or in combination of two or more. Among these, polyester resin is preferred because it can impart flexibility to the toner.

[0109] <<<Polyester resin>>> There are no particular restrictions on the polyester resin, and it can be appropriately selected depending on the purpose. Examples include crystalline polyester resin, amorphous polyester resin, and modified polyester resin. These may be used individually or in combination of two or more types.

[0110] -Amorphous polyester resin- The amorphous polyester resin (hereinafter sometimes referred to as "amorphous polyester," "amorphous polyester," "amorphous polyester resin," "unmodified polyester resin," "polyester resin component A," or "noncrystalline polyester resin") is not particularly limited and can be appropriately selected depending on the purpose. Examples include amorphous polyester resins obtained by reacting a polyol with a polycarboxylic acid. In this invention, amorphous polyester resin refers to a resin obtained by reacting a polyol with a polycarboxylic acid, as described above. Modified polyester resins, such as prepolymers described later, and modified polyester resins obtained by crosslinking and / or stretching the prepolymers, are not included in the amorphous polyester resin in this invention and are treated as modified polyester resins. The amorphous polyester is a polyester resin component soluble in tetrahydrofuran (THF). The amorphous polyester (polyester resin component A) is preferably a linear polyester resin.

[0111] Examples of the aforementioned polyols include diols. Examples of the aforementioned diols include alkylene (2-3 carbon atoms) 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; hydrogenated bisphenol A; and alkylene (2-3 carbon atoms) oxide (average number of added moles 1-10) adducts of hydrogenated bisphenol A. These may be used individually or in combination of two or more. Among these, it is preferable that the polyol contains 40 mol% or more of alkylene glycol.

[0112] Examples of the polycarboxylic acid include dicarboxylic acids. Examples of the dicarboxylic acid include alkyl groups having 1 to 20 carbon atoms, such as adipic acid, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, maleic acid, dodecenyl succinic acid, and octyl succinic acid; and succinic acid substituted with alkenyl groups having 2 to 20 carbon atoms. These may be used individually or in combination of two or more. Among these, it is preferable that the polycarboxylic acid contains 50 mol% or more of terephthalic acid.

[0113] The polyester resin component A may contain trivalent or higher carboxylic acids and / or trivalent or higher alcohols, trivalent or higher epoxy compounds, etc., at the ends of its resin chains in order to adjust the acid value and hydroxyl value. Among these, it is preferable to include aliphatic alcohols of trivalent or higher valent Examples of the carboxylic acids with a valency of 3 or higher include trimellitic acid, pyromellitic acid, or their acid anhydrides. Examples of trivalent or higher alcohols include glycerin, pentaerythritol, and trimethylolpropane.

[0114] There are no particular restrictions on the molecular weight of polyester resin component A, and it can be appropriately selected depending on the purpose, but it is preferably within the following range. The weight-average molecular weight (Mw) of polyester resin component A is preferably 3,000 to 10,000, and more preferably 4,000 to 7,000. The number-average molecular weight (Mn) of polyester resin component A is preferably 1,000 to 4,000, and more preferably 1,500 to 3,000. The molecular weight ratio (Mw / Mn) of polyester resin component A is preferably 1.0 to 4.0, and more preferably 1.0 to 3.5. The weight-average molecular weight and number-average molecular weight can be measured, for example, by GPC (gel permeation chromatography). The reason why the weight-average molecular weight and number-average molecular weight are preferably within the above range is that if the weight-average molecular weight and number-average molecular weight are too low, the toner may have poor heat resistance for storage and durability against stress such as agitation in the developing machine. If the weight-average molecular weight and number-average molecular weight are too high, the viscoelasticity of the toner when melted may increase, resulting in poor low-temperature fixing properties. Furthermore, if there is too much of a component with a molecular weight of 600 or less, the toner may have poor heat resistance for storage and durability against stress such as agitation in the developing machine. If there is too little of a component with a molecular weight of 600 or less, the low-temperature fixing properties may be poor.

[0115] The THF-soluble components with a molecular weight of 600 or less are preferably present in an amount of 2% to 10% by mass. One method for adjusting the content of this component is to extract polyester resin component A with methanol, remove components with a molecular weight of 600 or less, and then purify it.

[0116] There are no particular restrictions on the acid value of polyester resin component A, and it can be appropriately selected depending on the purpose, but 1 mg KOH / g to 50 mg KOH / g is preferred, and 5 mg KOH / g to 30 mg KOH / g is more preferred. When the acid value is 1 mg KOH / g or higher, the toner tends to become negatively charged, and furthermore, the affinity between the paper and the toner improves when fixing to paper, and low-temperature fixing performance can be improved. On the other hand, when the acid value is 50 mg KOH / g or lower, it is possible to prevent problems such as decreased electrostatic stability, especially electrostatic stability against environmental fluctuations.

[0117] There are no particular restrictions on the hydroxyl value of polyester resin component A, and it can be appropriately selected depending on the purpose, but 5 mg KOH / g or higher is preferred.

[0118] The glass transition temperature (Tg) of polyester resin component A is preferably 44°C to 65°C, more preferably 45°C to 65°C, and even more preferably 50°C to 60°C. When the Tg is 40°C or higher, the heat resistance of the toner during storage and its durability against stress such as agitation in the developing machine are improved, and its filming resistance is also improved. On the other hand, when the Tg is 65°C or lower, deformation due to heating and pressurization during toner fixing is improved, and low-temperature fixing performance is improved.

[0119] The content of polyester resin component A is preferably 80 to 90 parts by mass per 100 parts by mass of toner.

[0120] -Modified polyester resin- The modified polyester resin (hereinafter sometimes referred to as "modified polyester" or "polyester resin component C") is not particularly limited and can be appropriately selected depending on the purpose. Examples include reaction products of an active hydrogen group-containing compound and a polyester resin having a site that can react with the active hydrogen group-containing compound (hereinafter sometimes referred to as "prepolymer" or "polyester prepolymer"). The aforementioned modified polyester is a polyester resin insoluble in tetrahydrofuran (THF). The polyester resin component insoluble in tetrahydrofuran (THF) has a lower Tg and melt viscosity, ensuring low-temperature fixability, while having a branched structure in its molecular backbone and a three-dimensional network structure in its molecular chains. As a result, it has rubber-like properties, deforming at low temperatures but not flowing. Since the polyester resin component C has an active hydrogen group-containing compound and a site that can react with the active hydrogen group-containing compound, these sites behave like pseudo-crosslinking points, which enhances the rubbery properties of the amorphous polyester resin component A, making it possible to produce a toner with excellent heat resistance, storage resistance, and high-temperature offset resistance.

[0121] --Compounds containing active hydrogen groups-- The active hydrogen group-containing compound is a compound that reacts with a polyester resin having a site that can react with the active hydrogen group-containing compound.

[0122] The active hydrogen group is not particularly limited and can be appropriately selected depending on the purpose. Examples include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, and mercapto groups. These may be used individually or in combination of two or more.

[0123] There are no particular restrictions on the active hydrogen group-containing compound, and it can be appropriately selected depending on the purpose. However, if the polyester resin having a site that can react with the active hydrogen group-containing compound is a polyester resin containing an isocyanate group, amines are preferred because they can increase the molecular weight of the polyester resin through extension reactions, crosslinking reactions, etc. There are no particular restrictions on the amines mentioned above, and they can be appropriately selected depending on the purpose. Examples include diamines, trivalent or higher amines, amino alcohols, amino mercaptans, amino acids, and those in which the amino group has been blocked. These may be used individually or in combination of two or more. Among these, diamines and mixtures of diamines with small amounts of trivalent or higher amines are preferred.

[0124] The diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples 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 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 include 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diaminocyclohexane, and isophorone diamine. The aliphatic diamine is not particularly limited and can be appropriately selected depending on the purpose, and examples include ethylenediamine, tetramethylenediamine, and hexamethylenediamine.

[0125] There are no particular restrictions on the amines with a valency of 3 or higher, and they can be appropriately selected depending on the purpose. Examples include diethylenetriamine and triethylenetetramine.

[0126] The amino alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples include ethanolamine and hydroxyethylaniline.

[0127] The amino mercaptan is not particularly limited and can be appropriately selected depending on the purpose. Examples include aminoethyl mercaptan and aminopropyl mercaptan.

[0128] There are no particular restrictions on the amino acids mentioned above, and they can be appropriately selected depending on the purpose. Examples include aminopropionic acid and aminocaproic acid.

[0129] There are no particular limitations on the amino group that is blocked, and it can be appropriately selected depending on the purpose. Examples include ketimine compounds and oxazolidine compounds obtained by blocking the amino group with ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0130] --Polyester resin having a site that can react with active hydrogen group-containing compounds-- There are no particular limitations on the polyester resin having a site that can react with the active hydrogen group-containing compound, and it can be appropriately selected depending on the purpose. For example, a polyester resin containing an isocyanate group (hereinafter sometimes referred to as "polyester prepolymer having an isocyanate group") can be used. There are no particular limitations on the polyester resin containing an isocyanate group, and it 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 used.

[0131] The polyol is not particularly limited and can be appropriately selected depending on the purpose. Examples include diols, trivalent or higher alcohols, and mixtures of diols and trivalent or higher alcohols. These may be used individually or in combination of two or more. Among these, diols and mixtures of diols and small amounts of trivalent or higher alcohols are preferred.

[0132] The aforementioned diol is not particularly limited and can be appropriately selected depending on the purpose. Examples include linear alkylene glycols, diols having oxyalkylene groups, alicyclic diols, bisphenols, alkylene oxide adducts of alicyclic diols, and alkylene oxide adducts of bisphenols. Examples of the chain-like alkylene glycol include ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, and 1,6-hexanediol. Examples of diols having an oxyalkylene group include diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Examples of the alicyclic diol include 1,4-cyclohexanedimethanol and hydrogenated bisphenol A. Examples of the aforementioned bisphenols include bisphenol A, bisphenol F, and bisphenol S. Examples of the alkylene oxides include ethylene oxide, propylene oxide, and butylene oxide. There are no particular restrictions on the number of carbon atoms in the chain-like alkylene glycol, and it can be appropriately selected depending on the purpose, but 2 to 12 is preferred. Among these, at least one of a chain alkylene glycol having 2 to 12 carbon atoms and an alkylene oxide adduct of a bisphenol is preferred, and an alkylene oxide adduct of a bisphenol, or a mixture of an alkylene oxide adduct of a bisphenol and a chain alkylene glycol having 2 to 12 carbon atoms is more preferred.

[0133] There are no particular restrictions on the alcohols with a valency of 3 or higher, and they can be appropriately selected depending on the purpose. Examples include aliphatic alcohols with a valency of 3 or higher, polyphenols with a valency of 3 or higher, and alkylene oxide adducts of polyphenols with a valency of 3 or higher. There are no particular restrictions on the aliphatic alcohols with a valency of 3 or higher, and they can be appropriately selected depending on the purpose. Examples include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol. There are no particular restrictions on the aforementioned polyphenols with a valency of 3 or higher, and they can be appropriately selected depending on the purpose. Examples include trisphenol PA, phenol novolac, and cresol novolac. Examples of alkylene oxide adducts of polyphenols with a valency of 3 or higher include those obtained by adding an alkylene oxide such as ethylene oxide, propylene oxide, or butylene oxide to polyphenols with a valency of 3 or higher. When the diol and the trivalent or higher alcohol are used in mixture form, there are no particular restrictions on the mass ratio of the trivalent or higher alcohol to the diol (trivalent or higher alcohol / diol), and it can be appropriately selected depending on the purpose, but 0.01% to 10% by mass is preferred, and 0.01% to 1% by mass is more preferred.

[0134] The polycarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples include dicarboxylic acids, trivalent or higher carboxylic acids, and mixtures of dicarboxylic acids and trivalent or higher carboxylic acids. These may be used individually or in combination of two or more. Among these, dicarboxylic acids and mixtures of dicarboxylic acids and small amounts of trivalent or higher polycarboxylic acids are preferred.

[0135] The dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples include divalent alkanic acid, divalent alkeneic acid, and aromatic dicarboxylic acid. There are no particular restrictions on the divalent alkanoic acid, and it can be appropriately selected depending on the purpose. Examples 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 a divalent alkenoic acid having 4 to 20 carbon atoms is preferred. 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 include maleic acid and fumaric acid. The aromatic dicarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose, but aromatic dicarboxylic acids having 8 to 20 carbon atoms are preferred. 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 include phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, etc.

[0136] There are no particular restrictions on the carboxylic acid with a valency of three or more, and it can be appropriately selected depending on the purpose. Examples include aromatic carboxylic acids with a valency of three or more. There are no particular restrictions on the trivalent or higher aromatic carboxylic acid, and it can be appropriately selected depending on the purpose, but trivalent or higher aromatic carboxylic acids having 9 to 20 carbon atoms are preferred. There are no particular restrictions on the trivalent or higher aromatic carboxylic acid having 9 to 20 carbon atoms, and it can be appropriately selected depending on the purpose, and examples include trimellitic acid and pyromellitic acid.

[0137] As the polycarboxylic acid, an acid anhydride or lower alkyl ester of any of the following may be used: a dicarboxylic acid, a trivalent or higher carboxylic acid, or a mixture of a dicarboxylic acid and a trivalent or higher carboxylic acid. The aforementioned lower alkyl ester is not particularly limited and can be appropriately selected depending on the purpose. Examples include methyl esters, ethyl esters, and isopropyl esters. When the dicarboxylic acid and the trivalent or higher carboxylic acid are used in a mixture, there are no particular restrictions on the mass ratio of the trivalent or higher carboxylic acid to the dicarboxylic acid (trivalent or higher carboxylic acid / dicarboxylic acid), and it can be appropriately selected depending on the purpose, but 0.01% to 10% by mass is preferred, and 0.01% to 1% by mass is more preferred.

[0138] When polycondensing the polyol and the polycarboxylic acid, there are no particular restrictions on the equivalent ratio of the hydroxyl groups of the polyol to the carboxyl groups of the polycarboxylic acid (hydroxyl groups of the polyol / carboxyl groups of the polycarboxylic acid), and it can be appropriately selected depending on the purpose, but 1 to 2 is preferred, 1 to 1.5 is more preferred, and 1.02 to 1.3 is particularly preferred.

[0139] There are no particular restrictions on the content of polyol-derived structural units in the polyester prepolymer having isocyanate groups, and it can be appropriately selected depending on the purpose, but 0.5% to 40% by mass is preferred, 1% to 30% by mass is more preferred, and 2% to 20% by mass is particularly preferred. When the aforementioned content is 0.5% by mass or more, good hot offset resistance is achieved, and both heat resistance for toner storage and low-temperature fixing properties are achieved. When the content is 40% by mass or less, good low-temperature fixing properties are achieved.

[0140] There are no particular restrictions on the polyisocyanate, and it can be appropriately selected depending on the purpose. Examples include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, aromatic aliphatic diisocyanates, isocyanurates, and those obtained by blocking these with phenol derivatives, oximes, caprolactams, etc. There are no particular restrictions on the aliphatic diisocyanate, and it can be appropriately selected depending on the purpose. Examples include tetramethylene diisocyanate, hexamethylene diisocyanate, methyl 2,6-diisocyanatocaproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, and tetramethylhexane diisocyanate. There are no particular restrictions on the alicyclic diisocyanate, and it can be appropriately selected depending on the purpose. Examples include isophorone diisocyanate and cyclohexylmethane diisocyanate. The aromatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples 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. The aforementioned aromatic aliphatic diisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples include α,α,α',α'-tetramethylxylylene diisocyanate. There are no particular restrictions on the isocyanurates mentioned above, and they can be appropriately selected depending on the purpose. Examples include tris(isocyanatoalkyl)isocyanurate and tris(isocyanatocycloalkyl)isocyanurate. These may be used individually or in combination of two or more.

[0141] When reacting the polyisocyanate with a polyester resin having hydroxyl groups, there are no particular restrictions on the equivalent ratio (NCO / OH) of the isocyanate groups of the polyisocyanate to the hydroxyl groups of the polyester resin, and it can be appropriately selected depending on the purpose, but 1 to 5 is preferred, 1.2 to 4 is more preferred, and 1.5 to 2.5 is particularly preferred. When the equivalent ratio is 1 or higher, hot offset resistance is good, and when it is 5 or lower, low-temperature fixation is good.

[0142] There are no particular restrictions on the content of polyisocyanate-derived structural units in the polyester prepolymer having isocyanate groups, and it can be appropriately selected depending on the purpose, but 0.5% to 40% by mass is preferred, 1% to 30% by mass is more preferred, and 2% to 20% by mass is particularly preferred. When the content is 0.5% by mass or more, good hot offset resistance is obtained, and when it is 40% by mass or less, good low-temperature fixation is obtained.

[0143] The average number of isocyanate groups per molecule of the polyester prepolymer having isocyanate groups is not particularly limited and can be appropriately selected depending on the purpose, but it is preferably 1 or more, more preferably 1.5 to 3, and particularly preferably 1.8 to 2.5. When the average number is 1 or more, the molecular weight of the modified polyester resin becomes appropriate and the hot offset resistance is improved.

[0144] The modified polyester resin can be manufactured by a one-shot method or the like. As an example, a method for manufacturing urea-modified polyester resin will be described. First, a polyol and a polycarboxylic acid are heated to 150°C to 280°C in the presence of a catalyst such as tetrabutoxytitanate or dibutyltin oxide, and the resulting water is removed under reduced pressure as needed to obtain a polyester resin having hydroxyl groups. Next, the polyester resin having hydroxyl groups is reacted with a polyisocyanate at 40°C to 140°C to obtain a polyester prepolymer having isocyanate groups. Furthermore, the polyester prepolymer having isocyanate groups is reacted with amines at 0°C to 140°C to obtain a urea-modified polyester resin.

[0145] There are no particular restrictions on the number-average molecular weight (Mn) of the modified polyester resin, and it can be appropriately selected depending on the purpose. However, in GPC (gel permeation chromatography) measurements, 1,000 to 10,000 is preferred, and 1,500 to 6,000 is more preferred. There are no particular restrictions on the weight-average molecular weight of the modified polyester resin, and it can be appropriately selected depending on the purpose, but in GPC (gel permeation chromatography) measurements, a value of 20,000 to 1,000,000 is preferred. When the weight-average molecular weight is 20,000 or more, the toner becomes more fluid at low temperatures, preventing problems such as poor heat resistance during storage and reduced viscosity during melting, which can lead to decreased high-temperature offset performance.

[0146] Furthermore, when reacting a polyester resin having hydroxyl groups with polyisocyanates, or when reacting a polyester prepolymer having isocyanate groups with amines, a solvent may be used as needed. The solvent is not particularly limited and can be appropriately selected depending on the purpose. Examples include aromatic solvents, ketones, esters, amides, ethers, and other solvents that are inert to isocyanate groups. Examples of aromatic solvents include toluene and xylene. Examples of ketones include acetone, methyl ethyl ketone, and methyl isobutyl ketone. Examples of esters include ethyl acetate. Examples of amides include dimethylformamide and dimethylacetamide. Examples of ethers include tetrahydrofuran.

[0147] The glass transition temperature of the modified polyester resin is preferably -60°C or higher and 0°C or lower, and more preferably -40°C or higher and -20°C or lower. If the glass transition temperature is -60°C or higher, the flow of toner at low temperatures cannot be suppressed, which prevents problems such as deterioration of heat resistance for storage and deterioration of filming resistance. If the glass transition temperature is 0°C or lower, the toner cannot be sufficiently deformed by heating and pressurizing during fixing, which prevents problems such as insufficient low-temperature fixing performance.

[0148] There are no particular restrictions on the content of the modified polyester, and it can be appropriately selected depending on the purpose, but it is preferably 1 to 15 parts by mass, and more preferably 5 to 10 parts by mass, per 100 parts by mass of the toner. The molecular structures of the polyester resin components A and C can be confirmed by NMR measurements in solution and solid form, as well as by X-ray diffraction, GC / MS, LC / MS, IR measurements, and other methods. In simple terms, in the infrared absorption spectrum, 965±10 cm⁻¹ -1 and 990±10cm -1 One method for detecting amorphous polyester resins is one in which those that do not exhibit absorption based on δCH (out-of-plane angular bending vibration) of olefins are identified.

[0149] -Crystalline polyester- The crystalline polyester resin (hereinafter also referred to as "crystalline polyester" or "polyester resin component D") is not particularly limited and can be appropriately selected depending on the purpose. For example, a crystalline polyester resin obtained by reacting a polyol with a polycarboxylic acid can be used.

[0150] The aforementioned crystalline polyester resin exhibits thermal melting properties, showing a rapid decrease in viscosity near the fixing start temperature, due to its high crystallinity. By using the crystalline polyester resin having these characteristics together with the amorphous polyester resin, the toner exhibits good heat resistance due to its crystalline properties until just before the melting temperature. At the melting temperature, the crystalline polyester resin undergoes a rapid decrease in viscosity (sharp melt) due to melting, and consequently, it becomes compatible with the amorphous polyester resin. As a result, both exhibit a rapid decrease in viscosity and fixation, thus providing a toner that combines good heat resistance and low-temperature fixation properties. Furthermore, the release width (the difference between the lower limit temperature for fixation and the temperature at which high-temperature offset occurs) also shows favorable results. In this invention, crystalline polyester resin refers to a resin obtained by reacting a polyol with a polycarboxylic acid, as described above. Modified polyester resins, such as the prepolymer and resins obtained by crosslinking and / or stretching the prepolymer, do not belong to the category of crystalline polyester resin.

[0151] --Polyol-- There are no particular restrictions on the polyol, and it can be appropriately selected depending on the purpose. Examples include diols and polyols with a valent or higher nucleotide ratio.

[0152] Examples of the aforementioned diols include saturated aliphatic diols. Examples of the saturated aliphatic diols include linear saturated aliphatic diols and branched saturated aliphatic diols. These may be used individually or in combination of two or more. Among these, linear saturated aliphatic diols are preferred because they improve crystallinity and prevent a decrease in the melting point, and linear saturated aliphatic diols with 2 to 12 carbon atoms are more preferred.

[0153] Examples of the saturated aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, and 1,14-eicosanediol. Among these, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and 1,12-dodecanediol are preferred because they exhibit high crystallinity and excellent sharp-melt properties in the crystalline polyester resin.

[0154] Examples of trivalent or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol.

[0155] --Polycarboxylic acid-- The polycarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples include divalent carboxylic acids and trivalent or higher carboxylic acids.

[0156] Examples of the aforementioned divalent carboxylic acids include saturated aliphatic dicarboxylic acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, superiric 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; aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, and mesaconic acid; and further, their anhydrides and lower (1-3 carbon atoms) alkyl esters.

[0157] Examples of the carboxylic acids with a valency of 3 or higher include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and their anhydrides and lower (1-3 carbon atoms) alkyl esters.

[0158] The polycarboxylic acid may include, in addition to the saturated aliphatic dicarboxylic acid and aromatic dicarboxylic acid, a dicarboxylic acid having a sulfonic acid group. Furthermore, in addition to the saturated aliphatic dicarboxylic acid and aromatic dicarboxylic acid, a dicarboxylic acid having a double bond may also be included. These may be used individually or in combination of two or more.

[0159] The crystalline polyester resin is preferably composed of a linear saturated aliphatic dicarboxylic acid having 4 to 12 carbon atoms and a linear saturated aliphatic diol having 2 to 12 carbon atoms. That is, the crystalline polyester resin preferably has constituent units derived from a saturated aliphatic dicarboxylic acid having 4 to 12 carbon atoms and constituent units derived from a saturated aliphatic diol having 2 to 12 carbon atoms. This is preferable because it exhibits high crystallinity and excellent sharp melt properties, thus providing excellent low-temperature fixability.

[0160] The presence or absence of crystallinity in the crystalline polyester resin used in this invention can be confirmed by a crystallographic X-ray diffractometer (e.g., X'Pert Pro MRD, manufactured by Philips). The measurement method is described below. First, the target sample is ground in a mortar to create a sample powder, and the resulting sample powder is uniformly applied to the sample holder. Then, the sample holder is set in the diffractometer, and measurements are taken to obtain the diffraction spectrum. Crystallinity is determined to exist if the peak with the highest peak intensity among the obtained diffraction peaks in the range of 20° < 2θ < 25° has a peak width at half maximum of 2.0 or less. In this invention, a polyester resin that does not exhibit the above-mentioned state, as opposed to a crystalline polyester resin, is referred to as an amorphous polyester resin.

[0161] The measurement conditions for X-ray diffraction are described below. [Measurement conditions] Tension kV: 45kV Current: 40mA MPSS ·Upper ·Gonio • Scanmode: continue • Start angle: 3° End angle: 35° Angle Step: 0.02° Lucident beam optics ·Divergence slit: Div slit 1 / 2 Difflection beam optics ·Anti scatter slit: As fixed 1 / 2 ·Receiving slit: Prog rec slit

[0162] There are no particular restrictions on the melting point of the crystalline polyester resin, and it can be appropriately selected depending on the purpose, but it is preferably 60°C or higher and 80°C or lower. If the melting point is 60°C or higher, the crystalline polyester resin melts easily at low temperatures, preventing the problem of reduced heat resistance storage of the toner. If the melting point is 80°C or lower, the crystalline polyester resin does not melt sufficiently due to heating during fixing, preventing the problem of reduced low-temperature fixing performance.

[0163] There are no particular restrictions on the molecular weight of the crystalline polyester resin, and it can be appropriately selected depending on the purpose. The soluble orthodichlorobenzene content of the crystalline polyester resin is preferably such that, in GPC measurement, the weight-average molecular weight (Mw) is 3,000 to 30,000, and more preferably 5,000 to 15,000. The soluble orthodichlorobenzene content of the crystalline polyester resin is preferably such that the number average molecular weight (Mn) is 1,000 to 10,000, and more preferably 2,000 to 10,000, as measured by GPC. The molecular weight ratio Mw / Mn of the crystalline polyester resin is preferably 1.0 to 10, and more preferably 1.0 to 5.0. This is because substances with a sharp molecular weight distribution and low molecular weight exhibit excellent low-temperature fixation properties, while a high proportion of low molecular weight components reduces heat resistance during storage.

[0164] There are no particular restrictions on the acid value of the crystalline polyester resin, and it can be appropriately selected depending on the purpose. However, from the viewpoint of affinity between paper and resin, a value of 5 mg KOH / g or more is preferred, and 10 mg KOH / g or more is more preferred, in order to achieve the desired low-temperature fixation. On the other hand, to improve high-temperature offset resistance, a value of 45 mg KOH / g or less is preferred.

[0165] There are no particular restrictions on the hydroxyl value of the crystalline polyester resin, and it can be appropriately selected depending on the purpose. However, in order to achieve the desired low-temperature fixability and good electrostatic properties, a value of 0 mg KOH / g to 50 mg KOH / g is preferred, and 5 mg KOH / g to 50 mg KOH / g is more preferred.

[0166] The molecular structure of the crystalline polyester resin can be confirmed by NMR measurements in solution or solid state, as well as by X-ray diffraction, GC / MS, LC / MS, IR measurements, etc. A simpler method is infrared absorption spectroscopy, which can be used to determine the structure at 965±10 cm⁻¹. -1 or 990±10cm -1 One method involves detecting crystalline polyester resins that exhibit absorption based on δCH (out-of-plane bending vibration) of olefins.

[0167] There are no particular restrictions on the content of the crystalline polyester resin, and it can be appropriately selected depending on the purpose, but it is preferably 3 to 20 parts by mass, and more preferably 5 to 15 parts by mass, per 100 parts by mass of toner. If the content is 3 parts by mass or more, it is possible to prevent the problem of poor low-temperature fixing performance due to insufficient sharp melting by the crystalline polyester resin. If it is 20 parts by mass or less, it is possible to prevent problems such as reduced heat resistance and increased likelihood of image fogging.

[0168] <<Coloring agent>> There are no particular restrictions on the aforementioned colorants, and they can be appropriately selected according to the purpose. For example, 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), Vulcan fast yellow (5G, R), tartrazine lake, quinoline yellow lake, anthrazane yellow BG L, Isoindolinone Yellow, Bengara, Red Lead, Red Lead, Cadmium Red, Cadmium Mercury Red, Antimony Red, Permanent Red 4R, Para Red, Faise Red, Parachloro-orthonitroaniline Red, Risol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Risol Rubin GX, Permanent Red F5R, Brillia Bon Maroon 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, Perinon Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkali Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine, 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 dioxide, zinc oxide, and lithobone.

[0169] There are no particular restrictions on the content of the coloring agent, and it can be appropriately selected depending on the purpose, but it is preferably 1 to 15 parts by mass, and more preferably 3 to 10 parts by mass, per 100 parts by mass of toner.

[0170] The coloring agent can also be used as a masterbatch compounded with a resin. Examples of resins used in the production of a masterbatch or kneaded together with a masterbatch include, in addition to the other polyester resins mentioned above, polymers of styrene or its substituted derivatives such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, and styrene-α-chloromethacrylate copolymer. Examples include styrene copolymers such as styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, and styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, and paraffin wax. These may be used individually or in combination of two or more.

[0171] The masterbatch can be obtained by mixing and kneading a masterbatch resin and a colorant under high shear force. In this process, an organic solvent can be used to enhance the interaction between the colorant and the resin. Alternatively, a method known as the flushing method, in which an aqueous paste containing water from 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 allows the wet cake of the colorant to be used as is, eliminating the need for drying. A high-shear dispersion device such as a three-roll mill is preferably used for mixing and kneading.

[0172] <<wax>> There are no particular restrictions on the wax (release agent) and it can be appropriately selected from known waxes, such as natural waxes and synthetic waxes. These may be used individually or in combination of two or more types.

[0173] Examples of the aforementioned natural waxes include plant-based waxes such as carnauba wax, cotton wax, and wood wax; animal-based waxes such as beeswax and lanolin; mineral-based waxes such as ozokerite and cerucine; and petroleum waxes such as paraffin, microcrystalline, and petrolatum. Examples of the synthetic waxes include synthetic hydrocarbon waxes such as Fischer-Tropsch wax, polyethylene, and polypropylene; fatty acid amide compounds such as esters, ketones, ethers, 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. Among these, hydrocarbon waxes such as paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyethylene wax, and polypropylene wax are preferred.

[0174] There are no particular restrictions on the melting point of the mold release agent, and it can be appropriately selected depending on the purpose, but a melting point of 60°C or higher and 80°C or lower is preferred. If the melting point is 60°C or higher, the mold release agent melts easily at low temperatures, preventing the problem of poor heat resistance during storage. If the melting point is 80°C or lower, even when the resin has melted and is in the fixing temperature range, the mold release agent does not melt sufficiently, causing a fixing offset and preventing the problem of image defects.

[0175] There are no particular restrictions on the content of the release agent, and it can be appropriately selected depending on the purpose, but it is preferably 2 to 10 parts by mass, and more preferably 3 to 8 parts by mass, per 100 parts by mass of toner. If the content is 2 parts by mass or more, it is possible to prevent problems such as poor resistance to high temperature offset and poor low temperature fixing during fixing, and if it is 10 parts by mass or less, it is possible to prevent problems such as reduced heat resistance for storage and increased likelihood of image blurring.

[0176] The toner matrix particles are not particularly limited as long as they are those used in ordinary toner matrix particles, and may contain other components as appropriate, depending on the purpose. There are no particular restrictions on the content of the other components mentioned above, as long as they do not impair the properties of the toner, and they can be appropriately selected according to the purpose.

[0177] <Other ingredients> The aforementioned other components are not particularly limited as long as they are used in ordinary toners, and can be appropriately selected according to the purpose. Examples include charge control agents, external additives, flow improvers, cleaning performance improvers, and magnetic materials.

[0178] -Static control agent- The aforementioned charge control agent is not particularly limited and can be appropriately selected depending on the purpose. Examples include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxyamines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, elemental or compound phosphorus, elemental or compound tungsten, fluorine-based surfactants, metal salicylic acid salts, and metal salts of salicylic acid derivatives.

[0179] Examples of commercially available charge control agents include Bontron 03, a nigrosine-based dye; Bontron P-51, a quaternary ammonium salt; Bontron S-34, a metal-containing azo dye; E-82, an oxynaphthoic acid-based metal complex; E-84, a salicylic acid-based metal complex; and E-89, a phenolic condensate (all manufactured by Orient Chemical Industry Co., Ltd.); TP-302 and TP-415, quaternary ammonium salt molybdenum complexes (both manufactured by Hodogaya Chemical Co., Ltd.); LRA-901; and LR-147, a boron complex (both manufactured by Nippon Carlit Co., Ltd.).

[0180] The content of the charge control agent is determined by the type of binder resin, the presence or absence of additives used as needed, and the toner manufacturing method including the dispersion method, and is not uniquely limited, but is preferably 0.1 to 10 parts by mass, and more preferably 0.2 to 5 parts by mass, per 100 parts by mass of the binder resin. By having a content of 10 parts by mass or less, the chargeability of the toner becomes appropriate, the effect of the main charge control agent is improved, and it is possible to prevent an increase in electrostatic attraction force with the developing roller, a decrease in the fluidity of the developer, and a decrease in image density. These charge control agents can be dissolved and dispersed after melting and kneading with the masterbatch and resin, or they can be added when directly dissolving or dispersing in an organic solvent, or they can be fixed to the toner surface after toner particle formation.

[0181] -External additives- Examples of external additives include silica nanoparticles, hydrophobic silica, fatty acid metal salts (e.g., zinc stearate, aluminum stearate, etc.), metal oxides (e.g., titania, alumina, tin oxide, antimony oxide, etc.), and fluoropolymers. These may be used individually or in combination of two or more. Among these, hydrophobized inorganic nanoparticles are preferred. Examples of silica nanoparticles include R972, R974, RX200, RY200, R202, R805, and R812 (all manufactured by Nippon Aerosil Co., Ltd.). Examples of titania microparticles include P-25 (manufactured by Nippon Aerosil Co., Ltd.), STT-30, STT-65C-S (all manufactured by Titanium Industry Co., Ltd.), TAF-140 (manufactured by Fuji Titanium Industry Co., Ltd.), MT-150W, MT-500B, MT-600B, and MT-150A (all manufactured by Teika Co., Ltd.).

[0182] Examples of hydrophobized titanium oxide nanoparticles include T-805 (manufactured by Nippon Aerosil Co., Ltd.), STT-30A, STT-65S-S (all manufactured by Titanium Industry Co., Ltd.), TAF-500T, TAF-1500T (both manufactured by Fuji Titanium Industry Co., Ltd.), MT-100S, MT-100T (both manufactured by Teika Co., Ltd.), and IT-S (manufactured by Ishihara Sangyo Co., Ltd.).

[0183] Hydrophobized oxide nanoparticles, hydrophobized silica nanoparticles, hydrophobized titania nanoparticles, and hydrophobized alumina nanoparticles can be obtained, for example, by treating hydrophilic nanoparticles with a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, or octyltrimethoxysilane. Silicone oil-treated oxide nanoparticles and inorganic nanoparticles, obtained by treating silicone oil with heat if necessary to convert it into inorganic nanoparticles, are also suitable.

[0184] Examples of the silicone oils mentioned above 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, methacrylic-modified silicone oil, and α-methylstyrene-modified silicone oil.

[0185] There are no particular restrictions on the average particle size of the primary particles of the external additive, and it can be appropriately selected depending on the purpose, but it is preferably 100 nm or less, more preferably 1 nm to 100 nm, even more preferably 3 nm to 70 nm, and particularly preferably 5 nm to 70 nm. When the average particle size of the primary particles is within this range, it is possible to prevent problems such as inorganic fine particles becoming embedded in the toner and not being able to effectively exert their function, and problems such as uneven scratching of the photoreceptor surface. The external additive preferably contains at least one type of inorganic fine particles with an average particle size of 20 nm or less, and at least one type of inorganic fine particles with an average particle size of 30 nm or more. The specific surface area of ​​the aforementioned external additive, calculated by the BET method, is 20 m². 2 / g~500m 2 / g is preferable.

[0186] There are no particular restrictions on the content of the external additive, and it can be appropriately selected depending on the purpose, but it is preferably 0.1 to 5 parts by mass, and more preferably 0.3 to 3 parts by mass, per 100 parts by mass of toner.

[0187] - Fluidity improver - The aforementioned fluidity improver is not particularly limited as long as it can be surface-treated to increase its hydrophobicity and prevent deterioration of fluidity and electrostatic properties even under high humidity conditions, and can be appropriately selected according to the purpose. Examples include silane coupling agents, silylation agents, silane coupling agents having alkyl fluoride compounds, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils. It is particularly preferable to surface-treat the silica and titanium oxide with such a fluidity improver and use them as hydrophobic silica and hydrophobic titanium oxide.

[0188] -Cleaning performance enhancer- The cleaning agent is not particularly limited as long as it is added to the toner to remove residual post-transfer developer from the photoreceptor and primary transfer medium, and can be appropriately selected depending on the purpose. Examples include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, polymer microparticles produced by soap-free emulsion polymerization such as polymethyl methacrylate microparticles and polystyrene microparticles. The polymer fine particles are preferably those with a relatively narrow particle size distribution, and those with a volume-average particle size of 0.01 μm to 1 μm are preferred.

[0189] -Magnetic materials- The magnetic material is not particularly limited and can be appropriately selected depending on the purpose. Examples include iron powder, magnetite, and ferrite. Among these, white is preferred in terms of color.

[0190] For differential scanning calorimetry (DSC) of toner, the glass transition temperature (Tg1st) during the first heating step is preferably 44°C to 65°C. Note that the glass transition temperature of the toner referred to in configuration 1) above is this Tg1st. For the glass transition temperature (Tg1st) of the DSC component insoluble in tetrahydrofuran (THF) of the toner during the first heating step, -45°C to 5°C is preferred. The glass transition temperature (Tg2nd) in the second heating of the DSC of the components soluble in THF of the toner is preferably 20°C to 65°C. It is preferable that the glass transition temperature (Tg1st) in the first heating of the differential scanning calorimetry (DSC) of the toner and the glass transition point (Tg2nd) in the second heating satisfy Tg1st - Tg2nd ≥ 10 [°C], because the low-temperature fixing property and the heat-resistant storage property are improved.

[0191] Here, the glass transition temperature of the toner can be measured using, for example, a differential scanning calorimeter (DSC-60, manufactured by Shimadzu Corporation). For example, a DSC curve is measured using the above differential scanning calorimeter. From the obtained DSC curve, by using an analysis program, the DSC curve at the first heating is selected, and the glass transition temperature Tg1st at the first heating can be obtained using the endothermic shoulder temperature in the analysis program. The DSC curve at the second heating is selected, and the glass transition temperature Tg2nd at the second heating can be obtained using the endothermic shoulder temperature.

[0192] (Developer) The developer of the present invention contains at least the toner of the present invention, and optionally contains other components appropriately selected such as a carrier. The developer may be a one-component developer or a two-component developer, but when used in a high-speed printer or the like corresponding to the recent improvement in information processing speed, a two-component developer is preferable because the life is improved.

[0193] <Carrier> There is no particular limitation on the carrier, and it can be appropriately selected according to the purpose, but those having a core material and a resin layer covering the core material are preferable.

[0194] - Core material - There are no particular restrictions on the material of the core material, and it can be appropriately selected according to the purpose. Examples include manganese-strontium materials with a density of 50 emu / g to 90 emu / g, and manganese-magnesium materials with a density of 50 emu / g to 90 emu / g. In order to ensure image density, it is preferable to use highly magnetized materials such as iron powder with a density of 100 emu / g or more, or magnetite with a density of 75 emu / g to 120 emu / g. It is also preferable to use low-magnetized materials such as copper-zinc materials with a density of 30 emu / g to 80 emu / g, as this can mitigate the impact of the developer on the photoreceptor when it is in a condensed state, which is advantageous for improving image quality. These materials may be used individually or in combination of two or more.

[0195] There are no particular restrictions on the volume-average particle diameter of the core material, and it can be appropriately selected depending on the purpose, but 10 μm to 150 μm is preferred, and 40 μm to 100 μm is more preferred. If the volume-average particle diameter is less than 10 μm, there will be a large amount of fine powder in the carrier, which may reduce the magnetization per particle and cause carrier scattering. On the other hand, if it exceeds 150 μm, the specific surface area will decrease, which may cause toner scattering, and in full-color printing with many solid areas, the reproduction of solid areas may be particularly poor.

[0196] The toner of the present invention can be mixed with the carrier and used in a two-component developer. There are no particular restrictions on the amount of the carrier in the two-component developer, and it can be appropriately selected depending on the purpose, but 90 to 98 parts by mass and more preferably 93 to 97 parts by mass per 100 parts by mass of the two-component developer is preferred. The developer of the present invention can be suitably used for image formation by various known electrophotographic methods, such as magnetic one-component development methods, non-magnetic one-component development methods, and two-component development methods.

[0197] (Toner manufacturing method) The toner manufacturing method of the present invention is the method for manufacturing the toner described above. The toner manufacturing method includes a composite particle formation step and a removal step, and further includes other steps as necessary.

[0198] <Composite particle formation process> The composite particle formation step involves attaching resin fine particles to the surface of toner matrix particles to form composite particles. Examples of methods for forming the composite particles include known dissolution suspension methods, in which an oil phase containing components of toner matrix particles, such as the binder resin, colorant, and wax, is dispersed in an aqueous medium containing resin fine particles to form granules.

[0199] As an example of a dissolution suspension method, a method is shown in which a polyester resin is produced by an extension reaction and / or crosslinking reaction between the prepolymer and the curing agent, while composite particles are formed. This method involves preparing an aqueous medium, preparing an oil phase containing toner matrix particle material, emulsifying or dispersing the toner matrix particle material, and removing organic solvents.

[0200] -Preparation of aqueous media (aqueous phase)- The aqueous medium can be prepared, for example, by dispersing resin fine particles in the aqueous medium. There are no particular restrictions on the amount of resin fine particles added to the aqueous medium, and it can be appropriately selected depending on the purpose, but 0.5 to 10 parts by mass per 100 parts by mass of the aqueous medium is preferred. The aqueous medium is not particularly limited and can be appropriately selected depending on the purpose. Examples include water, a solvent miscible with water, and mixtures thereof. These may be used individually or in combination of two or more. Among these, water is preferred.

[0201] There are no particular restrictions on the solvent that can be miscible with water, and it can be appropriately selected depending on the purpose. Examples include alcohols, dimethylformamide, tetrahydrofuran, cellosolves, and lower ketones. Examples of alcohols include methanol, isopropanol, and ethylene glycol. Examples of lower ketones include acetone and methyl ethyl ketone.

[0202] -Preparation of the oil phase- The oil phase can be prepared by dissolving or dispersing a toner matrix particle material containing a binder resin, a colorant, and a wax, and optionally a curing agent, in an organic solvent.

[0203] There are no particular restrictions on the organic solvent, and it can be appropriately selected depending on the purpose, but an organic solvent with a boiling point of less than 150°C is preferred because it is easy to remove.

[0204] Examples of organic solvents with a boiling point of less than 150°C 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, and methyl isobutyl ketone. These may be used individually or in combination of two or more. Among these, ethyl acetate, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, and carbon tetrachloride are preferred, with ethyl acetate being more preferred.

[0205] -Emulsification or dispersion- The emulsification or dispersion of the toner material can be carried out by dispersing the oil phase containing the toner material in the aqueous medium. During the emulsification or dispersion of the toner material, the curing agent and the prepolymer can be subjected to an extension reaction and / or a crosslinking reaction.

[0206] There are no particular restrictions on the reaction conditions (reaction time, reaction temperature) for producing the prepolymer, and they can be appropriately selected depending on the combination of the curing agent and the prepolymer. The reaction time is preferably 10 minutes to 40 hours, and more preferably 2 to 24 hours. The reaction temperature is preferably 0°C to 150°C, and more preferably 40°C to 98°C.

[0207] In the aqueous medium, there are no particular restrictions on the method for stably forming a dispersion liquid containing the prepolymer, and it can be appropriately selected according to the purpose. Examples thereof include 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 dispersed by a shearing force.

[0208] There are no particular restrictions on the disperser for the dispersion, and it can be appropriately selected according to the purpose. For example, a low-speed shearing disperser, a high-speed shearing disperser, a friction disperser, a high-pressure jet disperser, an ultrasonic disperser, etc. can be mentioned. Among these, a high-speed shearing disperser is preferable in that the particle diameter of the dispersion (oil droplets) can be controlled to 2 μm to 20 μm.

[0209] When using the high-speed shearing disperser, conditions such as the rotation speed, dispersion time, and dispersion temperature can be appropriately selected according to the purpose. The rotation speed is preferably 1,000 rpm to 30,000 rpm, and more preferably 5,000 rpm to 20,000 rpm. The dispersion time is preferably 0.1 minute to 60 minutes in the case of the batch method. The dispersion temperature is preferably 0 °C to 150 °C under pressure, and more preferably 40 °C to 98 °C. Generally, the dispersion is easier when the dispersion temperature is higher.

[0210] It is preferable to reduce the primary particle system by increasing the rotation speed or lengthening the dispersion time.

[0211] There are no particular restrictions on the amount of the aqueous medium used when emulsifying or dispersing the toner material, and it can be appropriately selected according to the purpose. However, with respect to 100 parts by mass of the toner material, 50 parts by mass to 2,000 parts by mass is preferable, and 100 parts by mass to 1,000 parts by mass is more preferable. If the amount of the aqueous medium used is less than 50 parts by mass, the dispersion state of the toner material may deteriorate, and toner mother particles with a predetermined particle diameter may not be obtained. If it exceeds 2,000 parts by mass, the production cost may increase.

[0212] When emulsifying or dispersing the oil phase containing the toner material, it is preferable to use a dispersant from the viewpoint of stabilizing the dispersion, such as oil droplets, to achieve the desired shape and sharpen the particle size distribution. There are no particular restrictions on the dispersant, and it can be appropriately selected depending on the purpose. Examples include surfactants, dispersants of poorly water-soluble inorganic compounds, and polymeric protective colloids. These may be used individually or in combination of two or more. Among these, surfactants are preferred.

[0213] The surfactant is not particularly limited and can be appropriately selected depending on the purpose. For example, anionic surfactants, cationic surfactants, nonionic surfactants, and amphoteric surfactants can be used. Examples of anionic surfactants include alkylbenzene sulfonates, α-olefin sulfonates, and phosphate esters. Among these, those having a fluoroalkyl group are preferred.

[0214] -Removal of organic solvents- There are no particular restrictions on the method for removing the organic solvent from the dispersion liquid such as the emulsified slurry, and a suitable method can be selected depending on the purpose. Examples include gradually raising the temperature of the entire reaction system to evaporate the organic solvent in the oil droplets, and spraying the dispersion liquid into a dry atmosphere to remove the organic solvent from the oil droplets. Once the organic solvent is removed, composite particles are formed.

[0215] <Removal process> The removal step is a step of removing at least a portion of the resin fine particles from the composite particles, and it is preferable to remove a portion or all of the shell resin (resin (b1)) in the resin fine particles in order to improve low-temperature fixability. One example of a process for removing at least a portion of the resin microparticles is a cleaning process for washing the composite particles. Therefore, the removal process can also be considered a cleaning process.

[0216] In the cleaning step, a method for removing part or all of the resin (b1) is a method for removing part or all of (b1) by a chemical method. The aforementioned chemical method includes, for example, a step of washing the composite particles with a basic aqueous solution. By washing the composite particles with a basic aqueous solution, part or all of the shell resin (b1) can be dissolved.

[0217] The basic aqueous solution is not particularly limited as long as it is basic, and can be appropriately selected depending on the purpose. Examples include aqueous solutions of alkali metal hydroxides such as potassium hydroxide and sodium hydroxide, and ammonia. These may be used individually or in combination of two or more. Among these, potassium hydroxide and sodium hydroxide are preferred from the viewpoint of easily dissolving the shell resin (b1). The pH of the basic aqueous solution is preferably 8 to 14, and more preferably 10 to 12.

[0218] The mixing of the composite particles and the alkaline aqueous solution in the washing process can be carried out by methods such as adding the basic aqueous solution dropwise to the composite slurry under stirring. Alternatively, a basic aqueous solution may be added dropwise, followed by the addition of an acidic aqueous solution to neutralize the solution.

[0219] <Other processes> The aforementioned other processes are not particularly limited and can be appropriately selected depending on the purpose, and examples include drying processes and classification processes. The drying process is not particularly limited as long as it can remove the solvent from the composite particles, and can be appropriately selected depending on the purpose. The classification process may be carried out by removing the fine particles in a liquid using a cyclone, decanter, centrifugation, or other methods, or the classification operation may be performed after drying.

[0220] The composite particles obtained may be mixed with particles such as the external additive and the charge control agent. In this case, applying a mechanical impact force can suppress the detachment of particles such as the external additive from the surface of the toner matrix particles. There are no particular restrictions on the method of applying the aforementioned mechanical impact force, and it can be appropriately selected depending on the purpose. Examples include a method of applying impact force to a mixture using a blade rotating at high speed, and a method of introducing a mixture into a high-speed airflow, accelerating it, and causing particles to collide with each other or with a suitable impact plate.

[0221] There are no particular restrictions on the equipment used in the above method, and it can be appropriately selected according to the purpose. Examples include an Ongmill (manufactured by Hosokawa Micron Corporation), a modified I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) with reduced grinding air pressure, a hybridization system (manufactured by Nara Machine Works Co., Ltd.), a cryptron system (manufactured by Kawasaki Heavy Industries, Ltd.), and an automatic mortar and pestle.

[0222] (Toner storage unit) In this invention, a toner storage unit refers to a unit having the function of storing toner, in which toner is stored. Examples of the toner storage unit include a toner storage container, a developer, and a process cartridge. The aforementioned toner container refers to a container that holds toner. The aforementioned developing unit refers to one that has means for storing and developing toner. The process cartridge refers to a cartridge that integrates at least an image carrier and a developing means, contains toner, and is detachable from the image forming apparatus. The process cartridge may further include at least one selected from a charging means, an exposure means, and a cleaning means.

[0223] Next, an embodiment of the process cartridge is shown in Figure 2. As shown in Figure 2, the process cartridge of this embodiment incorporates a latent image carrier 101 and includes a charging device 102, a developing device 104, and a cleaning unit 107, and further includes other means as necessary. In Figure 2, reference numeral 103 denotes exposure from the exposure device, and reference numeral 105 denotes recording paper. The latent image carrier 101 can be the same as the electrostatic latent image carrier used in the image forming apparatus described later. Any charging member can be used for the charging device 102. In the image formation process using the process cartridge shown in Figure 2, the latent image carrier 101 rotates clockwise, and an electrostatic latent image corresponding to the exposed image is formed on its surface by charging with a charging device 102 and exposure 103 with an exposure means (not shown). This electrostatic latent image is developed using toner in the developing device 104, and the developed toner is transferred to the recording paper 105 by the transfer roller 108 and printed out. Next, the surface of the latent image carrier after image transfer is cleaned by the cleaning unit 107, and further static electricity is removed by a static elimination means (not shown), and the above operation is repeated again.

[0224] (Image forming apparatus and image forming method) The image forming apparatus of the present invention has the aforementioned toner storage unit and preferably comprises at least an electrostatic latent image carrier, an electrostatic latent image forming means, and a developing means, and may further have other means as needed. The image forming method according to the present invention includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, and a developing step of forming a toner image, which is a visible image, by developing the electrostatic latent image formed on the electrostatic latent image carrier using toner, wherein the toner is the toner of the present invention, and further includes other steps as necessary.

[0225] <Electrostatic latent image carrier> There are no particular restrictions on the material, structure, or size of the electrostatic latent image carrier, and can be appropriately selected from known materials. Examples of materials include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors such as polysilane and phthalopolymethine. Among these, amorphous silicon is preferred in terms of long lifespan. The linear velocity of the electrostatic latent image carrier is preferably 300 mm / s or higher.

[0226] <Electrostatic latent image forming means and electrostatic latent image forming process> 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 can be appropriately selected according to the purpose. For example, it could be a means having at least a charging member for charging the surface of the electrostatic latent image carrier and an exposure member for exposing the surface of the electrostatic latent image carrier to an image.

[0227] The electrostatic latent image formation step is not particularly limited as long as it is a step of forming an electrostatic latent image on the electrostatic latent image carrier, and can be appropriately selected according to the purpose. For example, it can be performed by charging the surface of the electrostatic latent image carrier and then exposing it in an image-like manner, and can be performed using the electrostatic latent image formation means.

[0228] -Charging member and charging- There are no particular limitations on the charging member, and it can be appropriately selected according to the purpose. Examples include contact chargers that are known themselves and equipped with conductive or semiconductive rollers, brushes, films, rubber blades, etc., and non-contact chargers that utilize corona discharge such as Corotron and Scorotron.

[0229] The charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using the charging member. The shape of the charging member can be any form other than a roller, such as a magnetic brush or a fur brush, and can be selected according to the specifications and configuration of the image forming apparatus.

[0230] The charging member is not limited to the contact-type charging member, but it is preferable to use a contact-type charging member because it reduces the amount of ozone generated from the charging member, thus providing an image forming apparatus.

[0231] <<Exposure component and exposure>> The exposure member is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier, which has been charged by the charging member, in the manner of the image to be formed, and can be appropriately selected according to the purpose. Examples of exposure members include various types such as copying optical systems, rod lens array systems, laser optical systems, and liquid crystal shutter optical systems.

[0232] There are no particular restrictions on the light source used in the exposure member, and it can be appropriately selected according to the purpose. Examples include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light-emitting diodes (LEDs), semiconductor lasers (LDs), electroluminescent devices (ELs), and other light-emitting materials in general.

[0233] Furthermore, various filters such as sharp-cut filters, band-pass filters, near-infrared cut filters, dichroic filters, interference filters, and color temperature conversion filters can be used to illuminate only the desired wavelength range.

[0234] The exposure can be performed, for example, by exposing the surface of the electrostatic latent image carrier in an image-like manner using the exposure member. In addition, in the present invention, a back-facing method may be employed in which the electrostatic latent image carrier is exposed in an image-like manner from the back side.

[0235] <Developing means and developing process> The developing means is not particularly limited as long as it is a developing means equipped with toner that develops the electrostatic latent image formed on the electrostatic latent image carrier to form a toner image which is a visible image, and can be appropriately selected according to the purpose. The development step is not particularly limited as long as it is a step of developing the electrostatic latent image formed on the electrostatic latent image carrier using toner to form a toner image, which is a visible image. It can be appropriately selected according to the purpose, for example, by the development means. The preferred developing means is a developing apparatus that includes an agitator that frictionally agitates and charges the toner, and a developer carrier that has a magnetic field generating means fixed inside and a rotatable developer carrier on which the developer containing the toner is carried.

[0236] <Other means and other processes> Other means include, for example, transfer means, fixing means, cleaning means, static elimination means, recycling means, and control means. Other processes include, for example, a transfer process, a fixing process, a cleaning process, a static elimination process, a recycling process, and a control process.

[0237] -Transfer means and transfer process- The transfer means is not particularly limited as long as it is a means for transferring a visible image to a recording medium, and can be appropriately selected according to the purpose. However, a configuration having a first transfer means for transferring a visible image onto an intermediate transfer body to form a composite transfer image, and a second transfer means for transferring the composite transfer image onto a recording medium is preferred. The aforementioned transfer step is not particularly limited as long as it is a step of transferring a visible image to a recording medium, and can be appropriately selected according to the purpose. However, a preferred method is to use an intermediate transfer medium, first transfer the visible image onto the intermediate transfer medium, and then second transfer the visible image onto the recording medium. The transfer step can be performed, for example, by charging the photoreceptor using a transfer charger to create the visible image, and can be carried out by the transfer means.

[0238] In this configuration, if the image to be secondarily transferred onto the recording medium is a color image consisting of multiple toners, the transfer means can sequentially superimpose each toner onto the intermediate transfer body to form an image on the intermediate transfer body, and the intermediate transfer means can then secondarily transfer the image on the intermediate transfer body onto the recording medium in one go. There are no particular restrictions on the intermediate transfer material, and it can be appropriately selected from known transfer materials depending on the purpose. For example, a transfer belt is a suitable example.

[0239] The transfer means (the primary transfer means, the secondary transfer means) preferably includes at least a transfer device that exfoliates the visible image formed on the photoreceptor toward the recording medium. Examples of the transfer device include a corona discharge transfer device, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device. While plain paper is a typical recording medium, there are no particular restrictions as long as it can transfer the unfixed image after development. It can be appropriately selected according to the purpose, and PET bases for OHPs can also be used.

[0240] - Fixing means and fixing process - The fixing means is not particularly limited as long as it is a means for fixing the transferred image transferred to the recording medium, and can be appropriately selected according to the purpose. For example, a known heating and pressing member is preferred. Examples of the heating and pressing member include a combination of a heating roller and a pressing roller, and a combination of a heating roller, a pressing roller and an endless belt. The fixing step is not particularly limited as long as it is a step of fixing the visible image transferred to the recording medium, and can be appropriately selected according to the purpose. For example, it may be performed for each color of toner after it has been transferred to the recording medium, or it may be performed simultaneously for each color of toner in a stacked state.

[0241] The fixing process can be carried out by the fixing means. The heating temperature in the aforementioned heating and pressurizing member is preferably 80°C to 200°C. In addition, in the present invention, depending on the purpose, a known optical fuser may be used together with or in place of the fixing means, for example. There are no particular restrictions on the surface pressure in the fixing process, and it can be appropriately selected according to the purpose, but 10 N / cm is recommended. 2 ~80 N / cm 2 It is preferable that this be the case.

[0242] -Cleaning methods and cleaning process- The cleaning means is not particularly limited as long as it can remove the toner remaining on the photoreceptor, and can be appropriately selected according to the purpose. Examples include magnetic brush cleaners, electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, and web cleaners. The cleaning process is not particularly limited as long as it can remove the toner remaining on the photoreceptor, and can be appropriately selected according to the purpose. For example, it can be carried out by the cleaning means.

[0243] -Static elimination means and static elimination process- The static elimination means is not particularly limited as long as it is a means of eliminating static electricity by applying a static elimination bias to the photoreceptor, and can be appropriately selected according to the purpose, for example, a static elimination lamp. The static elimination step is not particularly limited as long as it is a step of eliminating static electricity by applying a static elimination bias to the photoreceptor, and can be appropriately selected according to the purpose, for example, it can be carried out by the static elimination means.

[0244] -Recycling methods and recycling processes- The recycling means is not particularly limited as long as it is a means for recycling the toner removed by the cleaning process to the developing device, and can be appropriately selected according to the purpose, for example, known transport means. The recycling process is not particularly limited as long as it is a process of recycling the toner removed by the cleaning process to the developing device, and can be appropriately selected according to the purpose, for example, by the recycling means.

[0245] The image forming apparatus according to this embodiment will be described with reference to Figure 3. Figure 3 is a schematic diagram of an example of the image forming apparatus according to this embodiment.

[0246] The image forming apparatus 200 develops an electrostatic latent image into a visible image using toner manufactured by the toner manufacturing method described above, transfers this visible image to paper as an example of a recording medium, and fixes it to form an image. In this embodiment, the image forming apparatus 200 is described as an electrophotographic printer, but the present invention is not limited to this case, and may also be a copier, facsimile, etc.

[0247] As shown in Figure 3, the image forming apparatus 200 includes a paper feeding unit 210, a transport unit 220, an image forming unit 230, a transfer unit 240, and a fixing unit 250.

[0248] The paper feeding unit 210 includes a paper feed cassette 211 on which the paper to be fed is stacked, and a paper feed roller 212 that feeds the paper stacked in the paper feed cassette 211 one sheet at a time.

[0249] The transport unit 220 includes a roller 221 that transports the paper fed by the paper feed roller 212 toward the transfer unit 240, a pair of timing rollers 222 that hold the leading edge of the paper transported by the roller 221 and wait, and send the paper to the transfer unit 240 at a predetermined timing, and a paper output roller 223 that outputs the paper, on which the toner has been fixed by the fuser unit 250, to the paper output tray 224.

[0250] The image-forming unit 230 comprises, at predetermined intervals and arranged sequentially from left to right in Figure 3, an image-forming unit Y that forms an image using a developer containing yellow toner (toner Y), an image-forming unit C that uses a developer containing cyan toner (toner C), an image-forming unit M that uses a developer containing magenta toner (toner M), an image-forming unit K that uses a developer containing black toner (toner K), and an exposure unit 233. Each of the above toners (Y, C, M, K) is obtained by the manufacturing method described above.

[0251] In Figure 3, the four image forming units are substantially the same in configuration, except that they use different developers. Each image forming unit is rotatable clockwise in Figure 3 and includes a photosensitive drum (231Y, 231C, 231M, 231K) that carries the electrostatic latent image and toner image, chargers (232Y, 232C, 232M, 232K) that uniformly charge the surface of the photosensitive drum (231Y, 231C, 231M, 231K), toner cartridges (237Y, 237C, 237M, 237K) that supply toner of each color (Y, C, M, K), and an exposure unit 233 that charges the electrostatic latent image formed on the surface of the photosensitive drum (231Y, 231C, 231M, 231K) to the toner cartridges ( The system comprises: a developing unit (234Y, 234C, 234M, 234K) that develops a toner image using toner supplied from (237Y, 237C, 237M, 237K); a static eliminator (235Y, 235C, 235M, 235K) that removes static electricity from the surface of the photosensitive drum (231Y, 231C, 231M, 231K) after the toner image has been first transferred to the transfer medium; and a cleaning unit (236Y, 236C, 236M, 236K) that removes any remaining transfer toner from the surface of the photosensitive drum (231Y, 231C, 231M, 231K) after the static electricity has been removed by the static eliminator (235Y, 235C, 235M, 235K).

[0252] The exposure unit 233 is a device that, based on image information, reflects laser light L emitted from the light source 233a using polygon mirrors (233bY, 233bC, 233bM, 233bK) driven by motors, and irradiates the photosensitive drum (231Y, 231C, 231M, 231K). As a result, an electrostatic latent image based on the image information is formed on the photosensitive drum 231.

[0253] The transfer unit 240 includes a drive roller 241 and a driven roller 242, an intermediate transfer belt 243 which is stretched between these rollers and rotates counterclockwise in Figure 3 as a transfer medium when the drive roller 241 is driven, primary transfer rollers (244Y, 244C, 244M, 244K) which are provided on either side of the intermediate transfer belt 243 and facing the photosensitive drum 231, and a secondary transfer roller 246 which is provided on either side of the intermediate transfer belt 243 and facing the secondary opposing roller 245 at the position where the toner image is transferred to the paper.

[0254] In the transfer section 240, a primary transfer bias is applied to the primary transfer roller 244, transferring each toner image formed on the surface of the photosensitive drum 231 onto the intermediate transfer belt 243 (primary transfer). Furthermore, a secondary transfer bias is applied to the secondary transfer roller 246, transferring the toner image on the intermediate transfer belt 243 onto the paper being transported, sandwiched between the secondary transfer roller 246 and the secondary opposing roller 245 (secondary transfer).

[0255] The fixing unit 250 includes a heating roller 251 with a heater inside that heats the paper to a temperature higher than the toner fixing limit temperature, and a pressure roller 252 that forms a contact surface (nip portion) by rotatably pressing against the heating roller 251 and applying pressure. In this embodiment, the fixing limit temperature refers to the lower temperature at which the toner will fix. [Examples]

[0256] The present invention will be further described below with reference to examples and comparative examples, but the present invention is not limited in any way to these examples.

[0257] (Example 1) [Production of aqueous dispersion (W0-1) of resin microparticles (A)] In a reaction vessel equipped with a stirrer, a heating and cooling device, and a thermometer, 3810 parts by mass of water and 100 parts by mass of polyoxyethylene-1-(allyloxymethyl)alkyl ether sulfate ammonium (Aqualon KH-1025, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) were charged and stirred at 200 revolutions per minute until homogenized. After heating the homogenized mixture to a system temperature of 75°C, 90 parts by mass of a 10% by mass aqueous solution of ammonium persulfate was added, and then a mixture consisting of 400 parts by mass of styrene, 300 parts by mass of butyl acrylate, and 300 parts by mass of methacrylic acid was added dropwise over 4 hours. After dropwise addition, the mixture was aged at 75°C for 4 hours to obtain an aqueous dispersion (W0-1) of resin fine particles (A) containing a resin (a1-1), which is a polymer copolymerized with the monomer and polyoxyethylene-1-(allyloxymethyl)alkyl ether sulfate ammonium.

[0258] <Manufacturing of aqueous dispersion (W-1) of resin microparticles (A-1)> Next, 667 parts by mass of an aqueous dispersion of resin fine particles (A) (W0-1) and 248 parts by mass of water were charged into a reaction vessel equipped with a stirrer, a heating and cooling device, and a thermometer. 0.267 parts by mass of tert-butyl hydroperoxide (manufactured by NOF Corporation, Perbutyl H) was added, and the mixture was heated to raise the system temperature to 70°C. Then, 43.3 parts by mass of styrene, 23.3 parts by mass of butyl acrylate, and 18.0 parts by mass of a 1% by mass aqueous solution of ascorbic acid were added dropwise over 2 hours. After dropwise addition, the mixture was aged at 70°C for 4 hours to obtain an aqueous dispersion (W-1) of resin microparticles (A-1) containing resin (a2-1) and resin (a1-1), which are polymers copolymerized by the monomers using the resin microparticles in (W0-1) as seeds, as constituent components within the same particle. The volume-average particle size of the resin microparticles (A-1) was 51.5 nm. Aqueous dispersion (W-1) of resin fine particles (A-1) was neutralized with a 10% by mass aqueous ammonia solution to pH 9.0, and the precipitate obtained by centrifugation was allowed to dry to isolate the resin (a2-1). The glass transition temperature (Tg) of the resin was 53°C. The aqueous dispersion (W-1) of resin microparticles (A-1) was confirmed to contain resin microparticles (A-1) that include resin (a1-1) and resin (a2-1) as constituent components within the same particle, as follows. Specifically, 2 parts by mass of gelatin (Cook Gelatin, manufactured by Morinaga Milk Industry Co., Ltd.) were dissolved in 15 parts by mass of water heated to 95°C to 100°C. The gelatin solution was then air-cooled to 40°C, to which an aqueous dispersion of resin fine particles (A-1) (W-1) was mixed in a 1:1 mass ratio. After thorough stirring, the mixture was cooled at 10°C for 1 hour to produce a hardened gel. This gel was examined by preparing 80 nm thick sections from an ultramicrotome (Ultramicrotome UC7, FC7, Leica Microsystems) while maintaining a temperature of -80°C. These sections were then stained with a 2% by mass ruthenium tetroxide aqueous solution in vapor phase for 5 minutes, and finally observed using a transmission electron microscope (Hitachi Technologies, Ltd., H-7100).

[0259] <Synthesis of amorphous polyester resin> In a reaction vessel equipped with a condenser, stirrer, heating / cooling device, thermometer, and nitrogen inlet tube, 425 parts by mass of bisphenol A·PO2 molar adduct, 100 parts by mass of propylene glycol, 634 parts by mass of terephthalic acid·propylene glycol 2 molar adduct, and 0.5 parts by mass of titanium diisopropoxybistriethanolaminate as a condensation catalyst were added and the mixture was reacted at 230°C for 12 hours. Next, the reaction was carried out under reduced pressure of 10-15 mmHg. The recovered propylene glycol amounted to 195 parts by mass. Next, after cooling to 180°C, 30 parts by mass of trimellitic anhydride were added and the mixture was reacted at 180°C for 1 hour before being removed. After cooling the extracted resin to room temperature, an amorphous polyester was obtained. The glass transition temperature (Tg) of the resin was 42°C, the number-average molecular weight (Mn) was 2400, the weight-average molecular weight (Mw) was 5400, the hydroxyl value was 32 mgKOH / g, and the acid value was 18 mgKOH / g.

[0260] <Manufacturing of colorant dispersion> In a reaction vessel equipped with a condenser, stirrer, heating / cooling device, thermometer, and nitrogen inlet tube, 557 parts by mass of propylene glycol, 569 parts by mass of dimethyl terephthalate, 184 parts by mass of adipic acid, and 3 parts by mass of tetrabutoxytinate as a condensation catalyst were added, and the mixture was reacted at 180°C under a nitrogen stream for 8 hours while distilling off the methanol produced. Next, the reaction was carried out for 4 hours while gradually increasing the temperature to 230°C and distilling off the propylene glycol and water generated under a nitrogen atmosphere. The reaction was then carried out for another hour under reduced pressure of 0.007 MPa to 0.026 MPa. The recovered propylene glycol amounted to 175 parts by mass. Next, the mixture was cooled to 180°C, 121 parts by mass of trimellitic anhydride were added, and the mixture was reacted for 2 hours under atmospheric pressure and in a sealed state. Then, it was heated to 220°C under atmospheric pressure and the reaction continued until the softening point reached 180°C to obtain a polyester resin (number average molecular weight (Mn) = 8500). 20 parts by mass of copper phthalocyanine, 4 parts by mass of colorant dispersant (Abyssia, Solspers 28000), 20 parts by mass of the obtained polyester resin, and 56 parts by mass of ethyl acetate were placed in a beaker and stirred to uniformly disperse. Then, 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.

[0261] <Manufacturing of Modified Wax> In a pressure-resistant reaction vessel equipped with a stirrer, heating / cooling device, thermometer, and dropping cylinder, 454 parts by mass of xylene and 150 parts by mass of low molecular weight polyethylene (Sanyo Chemical Industries, Ltd., Sanwax LEL-400) were added. After purging with nitrogen, the temperature was raised to 170°C under stirring. At the same temperature, a mixed solution of 595 parts by mass of styrene, 255 parts by mass of methyl methacrylate, 34 parts by mass of di-t-butyl peroxyhexahydroterephthalate, and 119 parts by mass of xylene was added dropwise over 3 hours, and the mixture was then held at the same temperature for 30 minutes. Next, xylene was removed under reduced pressure of 0.039 MPa to obtain a modified wax. The sp value of the graft chain of the modified wax was 10.35 (cal / cm3) 1 / 2, the number-average molecular weight (Mn) was 1900, the weight-average molecular weight (Mw) was 5200, and the glass transition temperature (Tg) was 57°C.

[0262] <Manufacturing of mold release agent dispersion> Ten parts by mass of paraffin wax (HNP-9, manufactured by Nippon Seiro Co., Ltd.), one part by mass of modified wax, and 33 parts by mass of ethyl acetate were added to a reaction vessel equipped with a condenser, a stirrer, a heating and cooling device, and a thermometer. The mixture was heated to 78°C and stirred at the same temperature for 30 minutes, then cooled to 30°C over 1 hour to crystallize the paraffin wax into fine particles. The mixture was then wet-milled using an Ultraviscomil (manufactured by AIMEX) to obtain a [release agent dispersion]. The volume-average particle size of the [release agent dispersion] was 0.25 μm.

[0263] <Manufacturing of reactive prepolymers> In a reaction vessel equipped with a condenser, stirrer, heating / cooling device, thermometer, and nitrogen inlet tube, 439 parts by mass of bisphenol A·PO2 molar adduct, 329 parts by mass of bisphenol A·PO3 molar adduct, 206 parts by mass of terephthalic acid, 90 parts by mass of adipic acid, and 0.5 parts by mass of titanium diisopropoxybistriethanol laminate as a condensation catalyst were added, and the mixture was reacted for 10 hours under reduced pressure of 0.5 to 2.5 kPa while gradually increasing the temperature to 230°C. The resin was removed when its acid value fell below 1 mg KOH / g to obtain polyester. The glass transition temperature (Tg) of the resin was 45°C, the number average molecular weight (Mn) was 3900, the weight average molecular weight (Mw) was 11000, and the hydroxyl value was 25 mg KOH / g. Next, 448 parts by mass of polyester, 52 parts by mass of isophorone diisocyanate, and 500 parts by mass of ethyl acetate were placed in a pressure-resistant reaction vessel equipped with a stirrer, a heating and cooling device, and a thermometer. The reaction was carried out in a sealed state at 80°C for 10 hours to obtain a reactive prepolymer solution containing isocyanate groups at the molecular ends. The reactive prepolymer had a urethane group concentration of 2.0, a number-average molecular weight (Mn) of 6900, and a weight-average molecular weight (Mw) of 25000.

[0264] <Manufacturing of composite resin particles (C-1)> A dispersion was obtained by adding 165 parts by mass of deionized water, a mixture of 2.5 parts by mass of aqueous dispersion (W-1) and 12.5 parts by mass of aqueous dispersion (W0-1), 1 part by mass of sodium carboxymethylcellulose, 26 parts by mass of sodium dodecyldiphenyl ether disulfonate (manufactured by Sanyo Chemical Industries, Ltd., Eleminor MON-7), and 15 parts by mass of ethyl acetate to a beaker and mixing the mixture. Next, 71 parts by mass of amorphous polyester resin, 40 parts by mass of colored dispersion, 39 parts by mass of mold release agent dispersion, and 54 parts by mass of ethyl acetate were added to another beaker and mixed. Then, 18 parts by mass of reactive prepolymer solution and 0.3 parts by mass of isophorone diamine as a curing agent were added and mixed to obtain a mixed solution. This mixture was added entirely to the dispersion prepared earlier, and stirred at 10,000 rpm for 30 minutes using a TK autohomogenizer to obtain the final mixture. Next, the mixture was transferred to a reaction vessel equipped with a stirrer and a thermometer, and the ethyl acetate was removed by distillation at 50°C until the concentration was 0.5% by mass or less to perform a compounding process, thereby obtaining an aqueous dispersion of composite resin particles. The aqueous dispersion of the composite resin particles is a composite resin particle in which fine particles containing resin fine particles (A-1) are attached to resin particles containing an amorphous polyester resin and an amorphous polyurethane resin composed of a reaction product of a reactive prepolymer and isophorone diamine. The fact that the resin particles contained in the aqueous dispersion of the composite resin particles are composite resin particles in which fine particles containing resin fine particles (A-1) are attached to the resin particles was confirmed by magnified observation of the shape of the particles contained in the aqueous dispersion of the composite resin particles using an electron microscope (scanning electron microscope: SU-8230 (manufactured by Hitachi High-Technologies Corporation)). Next, sodium hydroxide was added to the aqueous dispersion of composite resin particles so that its pH was 12, and the mixture was stirred with a three-one motor for 1 hour. After that, it was centrifuged and deionized water was added again to re-slurry it. The process of centrifuging and re-slurrying was repeated several times, and then it was filtered by suction using a membrane filter (hereinafter referred to as the "washing and filtration process"), dried at 40°C for 18 hours, and the volatile matter was reduced to 0.5% by mass or less to obtain composite resin particles (C-1).

[0265] Next, 1.0 part by mass of colloidal silica (Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) was mixed with 100 parts by mass of composite resin particles as an external additive in a sample mill to obtain toner 1 after external additive treatment.

[0266] (Example 2) <Preparation of Toner-2> An aqueous dispersion of composite resin particles (C-2) was obtained in the same manner as in Example 1, except that the process for producing composite resin particles (C-1) was changed from "stirring at 10,000 rpm for 30 minutes in a TK autohomomial mixer" to "stirring at 12,000 rpm for 30 minutes in a TK autohomomial mixer". Next, toner-2 was obtained by performing an external additive treatment in the same manner as in Example 1.

[0267] (Example 3) <Creating Toner-3> An aqueous dispersion of composite resin particles (C-3) was obtained in the same manner as in Example 1, except that the process for producing composite resin particles (C-1) was changed from "stirring at 10,000 rpm for 30 minutes in a TK autohomomial mixer" to "stirring at 12,000 rpm for 10 minutes in a TK autohomomial mixer". Next, the external additive treatment was performed in the same manner as in Example 1 to obtain Toner-3.

[0268] (Example 4) <Creating Toner-4> An aqueous dispersion of composite resin particles (C-4) was obtained in the same manner as in Example 1, except that the process for producing composite resin particles (C-1) was changed from "stirring at 10,000 rpm for 30 minutes in a TK autohomogenizer" to "stirring at 10,000 rpm for 10 minutes in a TK autohomogenizer." Next, toner-4 was obtained by performing an external additive treatment in the same manner as in Example 1.

[0269] (Example 5) <Preparation of Toner-5> In Example 3, an aqueous dispersion of composite resin particles (C-5) was obtained in the same manner as in Example 1, except that the "mixture of 2.5 parts by mass of fine particle dispersion (W-1) and 12.5 parts by mass of fine particle dispersion (W0-1) (15 parts by mass)" in the production of composite resin particles was changed to "a mixture of 5 parts by mass of fine particle dispersion (W-1) and 10 parts by mass of fine particle dispersion (W0-1) (15 parts by mass)". Next, the external additive treatment was performed in the same manner as in Example 1 to obtain Toner-5.

[0270] (Comparative Example 1) <Preparation of Toner-6> In Example 1, an aqueous dispersion of composite resin particles (C-6) was obtained in the same manner as in Example 1, except that the composite resin particles (C-1) were heated at 40°C for 15 minutes and then cooled to 25°C immediately before suction filtration using a membrane filter. Next, toner-6 was obtained by performing an external additive treatment in the same manner as in Example 1.

[0271] (Comparative Example 2) <Creating Toner-7> An aqueous dispersion of composite resin particles (C-7) was obtained in the same manner as in Example 1, except that the process of "stirring at 10,000 rpm for 30 minutes in a TK autohomomial mixer" in the production of composite resin particles was changed to "stirring at 8,000 rpm for 2 minutes in a TK autohomomial mixer". Next, the external additive treatment was performed in the same manner as in Example 1 to obtain Toner-7.

[0272] (Comparative Example 3) <Preparing Toner-8> An aqueous dispersion of composite resin particles (C-8) was obtained in the same manner as in Example 1, except that "634 parts by mass of terephthalic acid-propylene glycol 2 molar adduct" in the synthesis of the amorphous polyester resin was changed to "571 parts by mass of terephthalic acid-propylene glycol 2 molar adduct and 63 parts by mass of adipic acid". Next, the external additive treatment was performed in the same manner as in Example 1 to obtain Toner-8.

[0273] <Career Creation> To prepare the resin coating solution, 100 parts by mass of silicone resin (organostraight silicone), 5 parts by mass of γ-(2-aminoethyl)aminopropyltrimethoxysilane, and 10 parts by mass of carbon black were added to 100 parts by mass of toluene and dispersed in a homomixer for 20 minutes. A carrier was prepared by applying the resin coating solution to the surface of 1,000 parts by mass of spherical magnetite with a volume-average particle size of 50 μm using a fluidized bed coating apparatus.

[0274] <Preparation of developer> Using a ball mill, 5 parts by mass of each toner and 95 parts by mass of each carrier were mixed to prepare each developer.

[0275] Next, for each obtained toner, the external additives were removed as much as possible by ultrasonic treatment to release them, bringing the toner closer to its original particle state, and the average value and standard deviation of the distance between resin microparticles were calculated. Furthermore, the glass transition temperature of the toner, the void diameter Φ (nm) in the cross-section of the toner matrix particles, and the void diameter Φ (nm) after heating the toner at the glass transition temperature of -3.0°C were determined by the method described above.

[0276] <Measurement of distance between resin microparticles> -Method for releasing external additives- [1] 50 ml of a 5% by mass aqueous solution containing a surfactant (product name Neugen ET-165, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added to a 100 ml screw tube, and 3 g of toner was added to the mixture and gently moved up and down and side to side. Then, the mixture was stirred with a ball mill for 30 minutes to allow the toner to blend into the dispersion solution. [2] Subsequently, ultrasonic homogenizer (product name homogenizer, model VCX750, CV33, manufactured by SONICS&MATERIALS Co., Ltd.) was used to apply ultrasonic energy for 60 minutes at an output of 40W. -Ultrasonic Conditions- • Vibration time: 60 minutes continuous ·Amplitude: 40W ·Vibration start temperature: 23±1.5℃ ·Temperature during vibration: 23±1.5℃ [3](1) The dispersion was filtered by suction using filter paper (product name: Qualitative filter paper (No. 2, 110 mm), manufactured by Advantec Toyo Co., Ltd.), washed twice again with deionized water and filtered to remove the freed additives, and then the toner particles were dried. (2) The toner obtained in (1) was observed using a scanning electron microscope (SEM). First, Si-containing additives and fillers were detected by observing the backscattered electron image. (3) The image from (1) was binarized using image processing software (ImageJ) to remove the external additive and filler. Next, a secondary electron image was observed at the same position as in (1). Since resin microparticles are not observed in the backscattered electron image but only in the secondary electron image, the image was compared with the image obtained in (3), and the microparticles present in the parts other than the residual additive and filler (the parts other than those excluded in (3)) were identified as resin microparticles. The distance between the resin microparticles (the distance between the centers of the particles) was measured using the aforementioned image processing software. This measurement was performed on 100 binarized images (one toner particle per image), and the average value was taken as the average distance between resin microparticles. The standard deviation of the distance between resin microparticles was calculated using the following formula, where x is the interparticle distance.

[0277]

number

[0278] [Shooting conditions] • Scanning electron microscope: SU-8230 (manufactured by Hitachi High-Technologies Corporation) • Magnification: 35,000x • Image type: SE(L): Secondary electrons, BSE(backscattered electrons) • Acceleration voltage: 2.0kV ·Acceleration current: 1.0μA • Probe current: Normal • Focus mode: UHR WD: 8.0mm

[0279] <Low temperature retention> Each toner is applied to the paper at a rate of 0.8 mg / cm² 2 The powder was spread evenly to achieve this. The method used to apply the powder to the paper involved using a printer with the heat fuser removed. Other methods may be used if the powder can be uniformly loaded at the above weight density. This paper is then fixed to a pressure roller at a speed (heating roller peripheral speed) of 213 mm / sec and a fixing pressure (pressure roller pressure) of 10 kg / cm². 2 The temperature at which cold offset occurs (MFT) was measured under these conditions. A lower cold offset temperature indicates better low-temperature fixing performance. [Cold Offset Evaluation Criteria] ◎: Minimum fixing temperature is 125℃ or lower ○: The minimum fixing temperature is greater than 125°C and 135°C or less. ×: The minimum fixing temperature is greater than 135°C ◎ and 〇 ratings indicate a passing grade.

[0280] <Heat-resistant storage stability> Each toner was stored at 50°C for 8 hours, then sieved through a 42-mesh sieve for 2 minutes, and the remaining amount on the mesh was measured to evaluate its heat resistance according to the following criteria. Note that toners with better heat resistance had a lower remaining amount. [Evaluation Criteria] ◎: Survival rate less than 5% ○: Survival rate is 5% or more but less than 15% △: Survival rate is 15% or more but less than 30% ×: Survival rate of 30% or more ◎, ○, and △ are all considered passing grades.

[0281] <Blocking resistance> A solid 3cm x 15cm rectangular image was printed on Ricoh PPC paper type 6000 <70W> A4 T-grain, with a toner adhesion rate of 0.85 mg / cm². 2 The image is formed in this manner, and 200 images are printed continuously on one side. The fixing temperature is controlled to be centered around the cold offset temperature + 20°C. The 200 printed images are left stacked for 1 hour, and then the adhesion between the images is evaluated. [Blocking Evaluation Criteria] ◎: The papers do not stick together at all. ○: The papers are slightly stuck together, but there are no problems with the image when the papers are separated. △: There is some slight sticking between the sheets of paper, and the gloss of the image changes when the sheets are separated. ×: The papers stick together, and when separated, the images or paper may be damaged. ◎, ○, and △ are all considered passing grades.

[0282] <Overall Judgment> Based on the evaluation results for the three categories mentioned above—"low-temperature fixation," "heat-resistant storage," and "blocking resistance"—an overall judgment was made based on the following criteria. [Evaluation Criteria] ◎: Two ◎s, and no △ or ×s. ○: No △, × △: No × ×:× exists The results are shown in Table 1.

[0283] [Table 1]

[0284] As is clear from the evaluation results in Table 1, the toners of Examples 1 to 5 showed sufficiently excellent results in low-temperature fixability, heat resistance, and blocking resistance. In particular, the toner of Example 5 showed particularly excellent results. In contrast, the toners of Comparative Examples 1 to 3 showed inferior results compared to the examples in at least one of the following areas: low-temperature fixability, heat resistance, and blocking resistance. [Explanation of Symbols]

[0285] 1. Shell resin 2 Core resin 3 Resin fine particles 4 Toner matrix particles 101 Latent Image Carrier 102 Charging device 104 Developing device 105 Recording paper 107 Cleaning Department 108 Transfer Roller 200 Image forming apparatus 210 Paper feed section 211 Paper feed cassette 212 Paper feed roller 220 Conveying section 221 Laura 222 Timing Roller 223 Paper output roller 224 Paper Output Tray 230 Image creation section 231Y, 231C, 231M, 231K233 Photosensitive Drum 232Y, 232C, 232M, 232K Charger 233bY, 233bC, 233bM, 233bK Polygon Mirror 234Y,234C,234M,234K developing device 235Y,235C,235M,235K Static eliminator 236Y,236C,236M,236K Cleaner 237Y, 237C, 237M, 237K Toner Cartridges 240 Transfer section 241 Drive roller 242 Driven roller 243 Intermediate transfer belt 244 Primary Transfer Roller 245 Secondary opposing roller 246 Secondary Transfer Roller 250 Fixing section 251 Heating roller 252 Pressure roller [Prior art documents] [Patent Documents]

[0286] [Patent Document 1] Japanese Patent Publication No. 2002-284881 [Patent Document 2] Japanese Patent Publication No. 2019-099809 [Patent Document 3] Japanese Patent Publication No. 2019-143128

Claims

1. A toner in which resin fine particles are attached to the surface of toner matrix particles containing at least a binder resin, a colorant, and a wax, The aforementioned binder resin includes polyester resin, The aforementioned resin fine particles include a polymer obtained by homopolymerizing or copolymerizing vinyl monomers. The glass transition temperature of the toner is 44.0°C or higher. When the void diameter in the cross-section of the toner matrix particles observed by a scanning electron microscope (SEM) is denoted as Φ (nm), there is one or fewer voids with Φ ≥ 200, and A toner characterized in that, after heating the toner at a glass transition temperature of -3.0°C and a heating rate of 130°C / min, there are three or more voids with a diameter of Φ≧200.

2. The toner according to claim 1, characterized in that, after heating the toner at its glass transition temperature of -3.0°C, there are 3 to 15 voids with a diameter of Φ≧200.

3. The toner according to claim 2, characterized in that, after heating the toner at its glass transition temperature of -3.0°C, there are 3 to 15 voids with a diameter of 500 ≥ Φ ≥ 200.

4. A toner storage unit characterized by storing the toner described in claim 1.

5. An image forming apparatus characterized by having the toner storage unit described in claim 4.

6. The process includes an electrostatic latent image formation step of forming an electrostatic latent image on an electrostatic latent image carrier, and a development step of forming a toner image, which is a visible image, by developing the electrostatic latent image formed on the electrostatic latent image carrier using toner. An image forming method characterized in that the toner is the toner described in claim 1.

7. A composite particle formation step of forming composite particles by attaching resin fine particles to the surface of toner matrix particles containing at least a binder resin, a colorant, and a wax in an aqueous medium containing an organic solvent, A method for manufacturing toner, comprising an external additive addition step of adding an external additive to the composite particles, The aforementioned binder resin includes polyester resin, The aforementioned resin fine particles include a polymer obtained by homopolymerizing or copolymerizing vinyl monomers. The glass transition temperature of the toner is 44.0°C or higher, and when the void diameter in the cross-section of the toner matrix particles observed by a scanning electron microscope (SEM) is Φ (nm), there is one or fewer voids with Φ ≥ 200, and A method for manufacturing toner, characterized in that, after heating the toner at a glass transition temperature of -3.0°C and a heating rate of 130°C / min, there are three or more voids with a diameter of Φ≧200.

Images