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

Abstract

To provide a toner that achieves both low temperature fixability and heat-resistant storage property, prevents dirt on a cleaning member and a photoreceptor, and has excellent electrification stability.SOLUTION: A toner according to the present invention is a toner in which a plurality of resin fine particles and inorganic external additives are present on a surface of a toner base particle containing a binder resin, a colorant, and wax. The coverage of the resin fine particle is 30% to 70%. The inorganic external additive covers a surface of an oxide of a metal element with a hydroxide of the metal element.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Toner cartridges require low-temperature fixing properties to reduce power consumption during fixing and save energy, as well as heat-resistant storage properties to enhance resistance to high temperatures and humidity during storage and transportation after manufacturing. Improving the low-temperature fixing properties of toner requires the use of low-melting-point materials, but toner manufactured using low-melting-point materials has poor heat-resistant storage properties, creating a trade-off between low-temperature fixing and heat-resistant storage.

[0003] Therefore, as a method to achieve both low-temperature fixability and heat-resistant storage of toner, for example, Patent Document 1 proposes a method of using composite resin particles as toner, which are manufactured by coating a part of the surface of resin particles with resin fine particles containing one or two types of resin as constituent components (see, for example, Patent Documents 1 to 4).

[0004] On the other hand, in recent years there has been a growing demand for longer lifespans and maintenance-free operation of photocopiers, and it is necessary to suppress toner contamination inside the machine. One of the causes of toner contamination inside the machine is toner scattering. As the charge of the toner does not stabilize over time and the amount of charge decreases, the toner is not sufficiently held by the carrier, and the toner in the developer unit scatters, contaminating the inside of the machine. In response to the demand for even greater suppression of toner scattering, there is a tendency to increase these external additives, but these external additives can inhibit toner fixing, posing a challenge in achieving higher low-temperature fixing performance. [Overview of the project] [Problems that the invention aims to solve]

[0005] However, in the prior art, there is a demand for a technology that can simultaneously satisfy both low-temperature fixing property and heat-resistant storage property, suppress contamination of the cleaning member and the photoreceptor, and have excellent charging stability such that toner scattering is reduced.

[0006] One aspect of the present invention aims to provide a toner that achieves both low-temperature fixing property and heat-resistant storage property, suppresses contamination of the cleaning member and the photoreceptor, and has excellent charging stability.

Means for Solving the Problems

[0007] One aspect of the toner according to the present invention is a toner in which a plurality of resin fine particles and inorganic external additives are present on the surface of toner base particles containing a binder resin, a colorant, and a wax, where the coating rate of the resin fine particles is 30% to 70%, and the inorganic external additive has the surface of the metal element oxide coated with a metal element hydroxide.

Advantages of the Invention

[0008] One aspect of the present invention can provide a toner that achieves both low-temperature fixing property and heat-resistant storage property, suppresses contamination of the cleaning member and the photoreceptor, and has excellent charging stability.

Brief Description of the Drawings

[0009] [Figure 1] It is a schematic configuration diagram showing an example of an image forming apparatus according to an embodiment. [Figure 2] It is a schematic configuration diagram showing another example of an image forming apparatus according to an embodiment. [Figure 3] It is a schematic configuration diagram showing another example of an image forming apparatus according to an embodiment. [Figure 4] It is a partially enlarged view of the image forming apparatus in FIG. 3. [Figure 5] It is a schematic configuration diagram showing an example of a process cartridge according to an embodiment.

Mode for Carrying Out the Invention

[0010] Hereinafter, embodiments of the present invention will be described in detail. The embodiments are not limited by the following description and can be appropriately changed without departing from the gist of the present invention. In addition, in this specification, "~" indicating a numerical range means including the numerical values described before and after it as the lower limit value and the upper limit value, unless otherwise specified.

[0011] <Toner> The toner according to one embodiment will be described. The toner according to one embodiment is a toner in which a plurality of organic resin particles and inorganic external additives are present on the surface of toner base particles containing a binder resin, a colorant, and a wax, the coating rate of the organic resin fine particles is 30% to 70%, and at least one kind of the inorganic external additives has a metal element hydroxide coating the surface of the metal element oxide.

[0012] In the present embodiment, the toner base having a plurality of organic resin particles on the surface is characterized. The coating rate between adjacent organic resin fine particles present on the surface of the toner base particles is 30% to 70%. By having the coating rate within this range, the toner surface can be covered with organic resin fine particles that do not sufficiently inhibit fixing, making the toner hard, and ensuring reliability (storage stability, adhesion), thereby achieving both high-level low-temperature fixing properties and heat-resistant storage properties.

[0013] In addition, in the present embodiment, at least one kind of the inorganic external additives used is characterized by having a metal element hydroxide coating the surface of the metal element oxide. By having the base material of the inorganic external additives be a metal element oxide, a toner with excellent charge stability can be provided. Furthermore, by coating the surface of the metal element oxide with a metal element hydroxide, the charge rising property of the toner is ensured and toner scattering can be suppressed at a high level.

[0014] Furthermore, in this embodiment, the toner matrix particles, on which multiple organic resin particles are present on the surface, are characterized in that at least one of the inorganic external additives is coated with a hydroxide of the metal element on the oxide surface of the metal element. By externally adding a metal element oxide coated with a hydroxide of the metal element to the matrix surface on which the organic resin particles are present, intermolecular interactions occur between the surface of the organic resin particles and the hydroxyl groups, preventing the inorganic external additive from being released from the toner. Therefore, the presence of multiple organic resin particles on the matrix surface hardens the toner, making it difficult for the external additive to become embedded, while simultaneously preventing its release from the toner. This effect is achieved when the coating rate of the organic resin particles on the matrix surface is 30% to 70%.

[0015] [Toner matrix particles] As described above, the toner according to one embodiment has toner matrix particles.

[0016] The toner matrix particles contain at least a binder resin and a colorant, and further, as may, other components.

[0017] Toner matrix particles are preferably obtained by dissolving or dispersing at least a binder resin and a colorant in an organic solvent, adding the resulting solution or dispersion to an aqueous phase, and removing the organic solvent from the resulting dispersion. More preferably, they are obtained by dissolving or dispersing at least a binder resin precursor and a colorant in an organic solvent, adding the resulting solution or dispersion to an aqueous phase to cause a crosslinking or extension reaction of the binder resin precursor, and then removing the organic solvent.

[0018] [Binding resin] The toner matrix particles contain a binder resin as a resin component.

[0019] Any binder resin suitable for toner can be used. Examples of binder resins include polyester resin, silicone resin, and styrene. -Common binder resins such as acrylic resin, styrene resin, epoxy resin, diene resin, phenolic resin, terpene resin, coumarin resin, amide-imide resin, butyral resin, urethane resin, and ethylene-vinyl acetate resin can be used. These may be used individually or in combination of two or more. Among these, polyester resin is preferred as the binder resin because it allows the toner to exhibit excellent low-temperature fixation.

[0020] (Polyester resin) The polyester resin preferably contains a nonlinear amorphous (non-crystalline) polyester resin (also called amorphous polyester resin A) and a crystalline polyester resin (also called crystalline polyester resin C). The nonlinear amorphous polyester resin A or crystalline polyester resin C is usually preferably contained in a component insoluble in tetrahydrofuran (THF).

[0021] ((Amorphous polyester resin)) Amorphous polyester resins are obtained using a polyhydric alcohol component and a polyhydric carboxylic acid component such as a polyhydric carboxylic acid, a polyhydric carboxylic acid anhydride, or a polyhydric carboxylic acid ester.

[0022] In this embodiment, amorphous polyester resin refers to a resin obtained using a polyhydric alcohol component and a polyhydric carboxylic acid component such as a polyhydric carboxylic acid, polyhydric carboxylic acid anhydride, or polyhydric carboxylic acid ester, as described above. Modified polyester resins, such as the prepolymers described later, and resins obtained by crosslinking and / or stretching the prepolymers, do not belong to the category of amorphous polyester resin.

[0023] Examples of polyhydric alcohol components 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, neopentyl glycol, glycerin, pentaerythritol, trimethylolpropane, hydrogenated bisphenol A, sorbitol, or their alkylene (2-3 carbon atoms) oxide (average number of added moles 1-10) adducts. These may be used individually or in combination of two or more.

[0024] Examples of polycarboxylic acid components include dicarboxylic acids such as adipic acid, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, and maleic acid; succinic acids substituted with C1-C20 alkyl groups or C2-C20 alkenyl groups, such as dodecenyl succinic acid and octyl succinic acid; trimellitic acid and pyromellitic acid; anhydrides of these acids and alkyl (C1-C8) esters of these acids. These may be used individually or in combination of two or more.

[0025] It is preferable that the amorphous polyester resin, the prepolymer described later, and the resin obtained by crosslinking and / or stretching the prepolymer are at least partially compatible. This compatibility improves low-temperature fixation and high-temperature offset resistance. For this reason, it is preferable that the polyhydric alcohol component and polyhydric carboxylic acid component constituting the amorphous polyester resin and the polyhydric alcohol component and polyhydric carboxylic acid component constituting the prepolymer described later have similar compositions.

[0026] There are no particular restrictions on the molecular weight of the amorphous polyester resin, and it can be appropriately selected according to the purpose. If the molecular weight is too low, the toner may have poor heat resistance during storage and poor durability against stress such as agitation in the developer. If the molecular weight is too high, the viscoelasticity of the toner during melting may increase, resulting in poor low-temperature fixation. In GPC measurement, it is preferable that the weight-average molecular weight (Mw) is 2,500 to 10,000, the number-average molecular weight (Mn) is 1,000 to 4,000, and the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn) (Mw / Mn) is 1.0 to 4.0.

[0027] There are no particular restrictions on the acid value of the amorphous polyester resin, 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 the low-temperature fixing performance can be improved. When the acid value is 50 mg KOH / g or lower, the electrostatic stability, especially the electrostatic stability against environmental fluctuations, does not decrease.

[0028] There are no particular restrictions on the hydroxyl value of amorphous polyester resin, and it can be appropriately selected depending on the purpose, but it is preferable to have a value of 5 mg KOH / g or higher.

[0029] There are no particular restrictions on the glass transition temperature (Tg) of amorphous polyester resin, and it can be appropriately selected depending on the purpose. If the Tg is too low, the toner may have poor heat resistance for storage and poor durability against stress such as agitation in the developer. If the Tg is too high, the viscoelasticity of the toner during melting may increase, resulting in poor low-temperature fixation. Therefore, the glass transition temperature Tg of amorphous polyester resin is preferably 40°C to 70°C, and more preferably 45°C to 60°C.

[0030] There are no particular restrictions on the content of amorphous polyester resin, and it can be appropriately selected depending on the purpose, but 50 to 95 parts by mass, and more preferably 60 to 90 parts by mass, per 100 parts by mass of toner. If the content of amorphous polyester resin is less than 50 parts by mass, the dispersibility of the pigment and release agent in the toner deteriorates, which may easily cause image blurring and distortion. If the content of amorphous polyester resin exceeds 95 parts by mass, the content of crystalline polyester decreases, which may result in poor low-temperature fixing performance. A more preferable range for the amorphous polyester resin content is advantageous in that it is superior in all aspects: high image quality, high stability, and low-temperature fixing performance.

[0031] The molecular structure of amorphous polyester resins can be determined by NMR measurements in solution and solid state, as well as by X-ray diffraction, GC / MS, LC / MS, and IR measurements. A simple method is infrared absorption spectroscopy, which can be used to determine the molecular structure at 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.

[0032] ((Crystalline polyester resin)) Crystalline polyester resins have constituent units derived from saturated aliphatic diols.

[0033] As the saturated aliphatic diol, it is preferable to use an alcohol component containing a linear aliphatic diol having 2 to 8 carbon atoms. This allows the crystalline polyester resin to be uniformly dispersed within the toner, preventing filming of the crystalline polyester resin, improving stress resistance, and achieving low-temperature fixing of the toner.

[0034] Crystalline polyester resins exhibit a thermal melting characteristic that shows a rapid decrease in viscosity near the fixing initiation temperature due to their high crystallinity. By using a crystalline polyester resin with such characteristics in toner, a toner with good heat resistance due to its crystallinity is obtained until just before the melting initiation temperature, and then a rapid decrease in viscosity (sharp melting) occurs at the melting initiation temperature, resulting in a toner that combines good heat resistance and low-temperature fixing properties. Furthermore, good results are also obtained regarding the release width (the difference between the fixing lower limit temperature and the hot offset occurrence temperature).

[0035] Crystalline polyester resins are obtained using a polyhydric alcohol component and a polyhydric carboxylic acid component such as a polyhydric carboxylic acid, a polyhydric carboxylic acid anhydride, or a polyhydric carboxylic acid ester.

[0036] In this embodiment, the term "crystalline polyester resin" refers to a resin obtained using a polyhydric alcohol component and a polyhydric carboxylic acid component such as a polyhydric carboxylic acid, polyhydric carboxylic acid anhydride, or polyhydric carboxylic acid ester, as described above. Modified crystalline polyester resins, such as the prepolymers described later, and resins obtained by crosslinking and / or stretching the prepolymers, do not belong to the category of crystalline polyester resin.

[0037] -Polyhydric alcohol components- There are no particular restrictions on the polyhydric alcohol component; it can be appropriately selected depending on the purpose. Examples include diols and trihydric or higher alcohols.

[0038] Examples of diols include saturated aliphatic diols. Examples of saturated aliphatic diols include linear saturated aliphatic diols and branched saturated aliphatic diols. Among these, linear saturated aliphatic diols are preferred, and linear saturated aliphatic diols with 2 to 8 carbon atoms are more preferred. If the saturated aliphatic diol is branched, the crystallinity of the crystalline polyester resin may decrease, and the melting point may be lowered. Furthermore, if the main chain has 2 or more carbon atoms, the rise in melting temperature is suppressed when condensation polymerization is carried out with aromatic dicarboxylic acids, enabling low-temperature fixing. On the other hand, if the carbon number is 8 or less, practical materials can be obtained.

[0039] Examples of 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-eicosandecanediol. Among these, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol are preferred because they exhibit high crystallinity in crystalline polyester resins and excellent sharp-melt properties.

[0040] Examples of alcohols with a hydride of 3 or higher include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. These can be used individually or in combination of two or more types.

[0041] -Polyhydric carboxylic acid components- Sebacic acid is used as the polycarboxylic acid component, but other divalent carboxylic acids or trivalent or higher carboxylic acids can be used in combination depending on the purpose.

[0042] Examples of 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 also their anhydrides and lower alkyl esters.

[0043] Examples of trivalent or higher carboxylic acids include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalentricarboxylic acid, and their anhydrides and lower alkyl esters.

[0044] In addition to saturated aliphatic dicarboxylic acids and aromatic dicarboxylic acids, polycarboxylic acid components may also include dicarboxylic acid components having a sulfonic acid group. Furthermore, in addition to saturated aliphatic dicarboxylic acids and aromatic dicarboxylic acids, dicarboxylic acid components having a double bond may also be included.

[0045] These can be used individually or in combination of two or more types.

[0046] 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 preferable that it be 60°C or higher and less than 80°C. If the melting point of the crystalline polyester resin is 60°C or higher, melting of the crystalline polyester resin at low temperatures is suppressed, and the heat resistance of the toner can be maintained. If the melting point of the crystalline polyester resin is less than 80°C, sufficient melting of polyester resin A due to heating during fixing can be achieved, and a decrease in low-temperature fixing performance can be suppressed.

[0047] The melting point can be determined by the endothermic peak value of the DSC chart in differential scanning calorimeter (DSC) measurements.

[0048] There are no particular restrictions on the molecular weight of the crystalline polyester resin, and it can be appropriately selected according to the purpose. However, from the viewpoint that a sharp molecular weight distribution and low molecular weight resins have excellent low-temperature fixation properties, and that a large amount of low molecular weight components worsens heat resistance and storage properties, it is preferable that the soluble orthodichlorobenzene content of the crystalline polyester resin has a weight-average molecular weight (Mw) of 3,000 to 30,000, a number-average molecular weight (Mn) of 1,000 to 10,000, and an Mw / Mn ratio of 1.0 to 10, as measured by GPC.

[0049] 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 higher is preferable, and 10 mg KOH / g or higher is more preferable, in order to achieve the desired low-temperature fixation properties. On the other hand, to improve resistance to high-temperature offset, a value of 45 mg KOH / g or lower is preferable.

[0050] 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 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.

[0051] The molecular structure of crystalline polyester resins can be confirmed by NMR measurements in solution and solid state, as well as by X-ray diffraction, GC / MS, LC / MS, and IR measurements. A simple method is infrared absorption spectroscopy, which can be used to determine the molecular 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.

[0052] There are no particular restrictions on the content of crystalline polyester resin, and it can be appropriately selected depending on the purpose, but preferably it is 2 to 20 parts by mass, and more preferably 5 to 15 parts by mass, per 100 parts by mass of toner. When the content of crystalline polyester resin is 2 parts by mass or more, sharp melting by the crystalline polyester resin is sufficient, and sufficient low-temperature fixing properties can be achieved. When the content of crystalline polyester resin is 20 parts by mass or less, heat resistance for storage can be maintained and image fogging can be suppressed. When the content of crystalline polyester resin is within the above more preferable range, it is advantageous in that it is excellent in all aspects of high image quality, high stability, and low-temperature fixing properties.

[0053] [Coloring agent] There are no particular restrictions on the colorants used, 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 BGL, Isoindolinone Yellow, Bengara, Red Lead, Red Lead, Cadmium Red, Cadmium Mercury Red, Antimony Red, Permanent Red 4R, Para Red, Faise Red, Parachlor-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, Brilli Antcarmine 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, Navy 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.

[0054] There are no particular restrictions on the amount of colorant, 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.

[0055] The colorant can also be used as a masterbatch compounded with the resin. Examples of resins used in the production of the masterbatch or mixed together with the masterbatch include, in addition to hybrid resins, 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, 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.

[0056] A masterbatch can be obtained by mixing and kneading a 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, is preferred because it allows the use of a wet cake of the colorant without the need for drying. For mixing and kneading, a high-shear dispersion device such as a three-roll mill is preferably used.

[0057] [Resin fine particles] The resin microparticles are arranged on the surface of the toner matrix particles so as to cover the surface of the toner matrix particles. The coverage rate of the resin microparticles is preferably 30% to 70%. A coverage rate of 30% or more ensures the heat resistance of the toner during storage. A coverage rate of 70% or less allows external additives to adhere more easily and facilitates heat transfer during toner fixing, thus ensuring proper fixing.

[0058] (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. -Method for releasing external additives- [1] Add 50 ml of a 5% aqueous solution containing a surfactant (product name Neugen ET-165, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) to a 100 ml screw-top 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 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 additives and fillers. 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. Image processing software is then used to measure the distance between the resin microparticles (the distance between the centers of the particles). 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 (1), where x is the interparticle distance.

[0059]

number

[0060] [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

[0061] The volume-average primary particle diameter of the resin fine particles is preferably between 5 nm and 100 nm, and more preferably between 10 nm and 50 nm. A volume-average primary particle diameter of 5 nm to 100 nm results in good low-temperature fixation. The volume-average primary particle diameter can be measured, for example, by scanning electron microscopy (SEM) imaging.

[0062] The resin fine particles (hereinafter sometimes also referred to as "resin fine particles (B)") preferably have a core resin (core part) and a shell resin (outer shell part) 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).

[0063] 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.

[0064] Examples of vinyl monomers include (1) to (10) listed below. (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.

[0065] Examples of alkenes include ethylene, propylene, and α-olefins.

[0066] Examples of alkadienes include butadiene, isoprene, 1,4-pentadiene, 1,6-hexadiene, and 1,7-octadiene. (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. (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.

[0067] (2) Carboxyl group-containing vinyl monomers and salts thereof Examples of carboxyl group-containing vinyl monomers and their salts include unsaturated monocarboxylic acids (salts), unsaturated dicarboxylic acids (salts), and their anhydrides (salts), as well as their monoalkyl (1-24 carbon atoms) esters or salts.

[0068] 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.

[0069] In this embodiment, "(salt)" means an acid or a salt thereof. For example, C3-C30 unsaturated monocarboxylic acid (salt) means an unsaturated monocarboxylic acid or a salt thereof. In this embodiment, "(meth)acrylic" means methacrylic acid or acrylic acid. In this embodiment, "(meth)acryloyl" means methacryloyl or acryloyl. In this embodiment, "(meth)acrylate" means methacrylate or acrylate.

[0070] (3) Sulfonic acid group-containing vinyl monomers, vinyl sulfate monoesters, and salts thereof Examples of 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), etc.

[0071] 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).

[0072] (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), (meth)acryloyloxyalkyl (1-24 carbon atoms) phosphonic acid (salt), and the like.

[0073] Specific examples of (meth)acryloyloxyalkyl (1-24 carbon atoms) phosphate monoesters (salts) include 2-hydroxyethyl (meth)acryloyl phosphate (salt) and phenyl-2-acryloyloxyethyl phosphate (salt).

[0074] Specific examples of (meth)acryloyloxyalkyl (1-24 carbon atoms) phosphonic acid (salt) include 2-acryloyloxyethylphosphonic acid (salt).

[0075] 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.

[0076] (5) Hydroxyl group-containing vinyl monomer Examples of 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.

[0077] (6) Nitrogen-containing vinyl monomer Examples of 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.

[0078] (6-1) Examples of amino group-containing vinyl monomers include aminoethyl (meth)acrylate.

[0079] (6-2) Examples of amide group-containing vinyl monomers include (meth)acrylamide and N-methyl(meth)acrylamide.

[0080] (6-3) Examples of nitrile group-containing vinyl monomers include (meth)acrylonitrile, cyanostyrene, and cyanoacrylate.

[0081] (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).

[0082] (6-5) Examples of nitro group-containing vinyl monomers include nitrostyrene.

[0083] (7) Epoxy group-containing vinyl monomer Examples of epoxy group-containing vinyl monomers include glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, and p-vinylphenylphenyl oxide.

[0084] (8) Halogen-containing vinyl monomers Examples of halogen-containing vinyl monomers include vinyl chloride, vinyl bromide, vinylidene chloride, allyl chloride, chlorostyrene, bromostyrene, dichlorostyrene, chloromethylstyrene, tetrafluorostyrene, and chloroprene.

[0085] (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.].

[0086] Examples of vinyl (thio) ethers include vinyl methyl ether.

[0087] Examples of vinyl ketones include vinyl methyl ketone.

[0088] (10) Other vinyl monomers Other vinyl monomers include, for example, tetrafluoroethylene, fluoroacrylate, isocyanatoethyl (meth)acrylate, and m-isopropenyl-α,α-dimethylbenzyl isocyanate.

[0089] 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.

[0090] As the resin (b1), styrene-acrylic resin is preferred from the viewpoint of low-temperature fixation. Specifically, as the styrene-acrylic resin, styrene-(meth)acrylic acid ester copolymer and (meth)acrylic acid ester copolymer are preferred, and styrene-(meth)acrylic acid ester copolymer is more preferred.

[0091] 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.

[0092] The vinyl monomer used in resin (b2) is the same as that used in resin (b1).

[0093] 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.

[0094] As for the resin (b2), styrene-acrylic resin is preferred from the viewpoint of low-temperature fixation. Specifically, as for the styrene-acrylic resin, styrene-(meth)acrylic acid ester copolymer and (meth)acrylic acid ester copolymer are preferred, and styrene-(meth)acrylic acid ester copolymer is more preferred.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.).

[0099] Specifically, by using a composition such as the following, it becomes possible to adjust each G'' to the aforementioned range. (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.

[0100] The glass transition temperature (Tg) calculated from the constituent monomers is a value that can be calculated using the Fox method.

[0101] 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.]

[0102] (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.

[0103] 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.

[0104] 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.

[0105] 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).

[0106] (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.

[0107] In this embodiment, the loss modulus G'' of the viscoelastic properties is measured, for example, using the viscoelasticity measuring device described below. • Equipment: ARES-24A (manufactured by Rheometric Corporation) • Jig: 25mm parallel plate • Frequency: 1Hz • Distortion rate: 10% • Heating rate: 5°C / min

[0108] The acid value (AVb1) of 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 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.

[0109] 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).

[0110] 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.

[0111] 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).

[0112] The acid value can be measured, for example, by the method specified in JIS K0070:1992.

[0113] 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. When the glass transition temperature of resin (b1) is higher than that of resin (b2), it is possible to achieve an excellent balance between the ease with which resin fine particles (B) adhere to the surface of the toner to form toner particles and the low-temperature fixation performance of the toner according to one embodiment.

[0114] The glass transition temperature (Tg) of the resin (b1) is preferably 0°C to 150°C, and more preferably 50°C to 100°C. If the glass transition temperature is 0°C or higher, the heat resistance for storage can be improved, and if it is 150°C or lower, there is less inhibition of low-temperature fixing properties.

[0115] The Tg of resin (b2) is preferably -30°C to 100°C, more preferably 0°C to 80°C, and even more preferably 30°C to 60°C. If the glass transition temperature is -30°C or higher, the heat resistance for storage can be improved, and if it is 100°C or lower, there is less inhibition of low-temperature fixing properties.

[0116] Tg is measured using the method (DSC) specified in ASTM D3418-82 with a "DSC20, SSC / 580" [manufactured by Seiko Electronics Industries, Ltd.].

[0117] The solubility parameter of resin (b1) (hereinafter sometimes abbreviated as SP value) is set at 9 (cal / cm³) from the viewpoint of the ease of toner particle formation. 3 ) 1 / 2 ~13 (cal / cm) 3 ) 1 / 2is preferred, 9.5 (cal / cm 3 ) 1 / 2 ~12.5 (cal / cm 3 ) 1 / 2 is more preferred, 10.5 (cal / cm 3 ) 1 / 2 ~11.5 (cal / cm 3 )1 / 2 is even more preferred.

[0118] The SP value of the resin (b1) can be adjusted by changing the types of the constituent monomers and their composition ratios.

[0119] As the SP value of the resin (b2), from the viewpoint of the ease of forming toner particles, 8.5 (cal / cm 3 ) 1 / 2 ~12.5 (cal / cm 3 ) 1 / 2 is preferred, 9 (cal / cm 3 ) 1 / 2 ~12 (cal / cm 3 ) 1 / 2 is more preferred, 10 (cal / cm 3 ) 1 / 2 ~11 (cal / cm 3 )1 / 2 is even more preferred.

[0120] The SP value of the resin (b2) can be adjusted by changing the types of the constituent monomers and their composition ratios.

[0121] The SP value is calculated by the method by Fedors [Polym. Eng. Sci. 14(2)152, (1974)].

[0122] In the resin (b1), from the viewpoints of the Tg of the resin (b1) and the copolymerizability with other monomers, it is preferable to contain 10% by mass to 80% by mass of styrene as a constituent monomer based on the total mass of the resin (b1), and more preferably 30% by mass to 60% by mass.

[0123] 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).

[0124] 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.

[0125] 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 ease of toner formation and low-temperature fixation.

[0126] 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 (Mw) 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.

[0127] 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.

[0128] 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.

[0129] 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".

[0130] The number-average molecular weight (Mn) and weight-average molecular weight (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]

[0131] 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.

[0132] Known manufacturing methods can be used to produce resin fine particles (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).

[0133] 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).

[0134] 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.

[0135] 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.

[0136] 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.

[0137] 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.

[0138] 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.

[0139] 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.

[0140] In this embodiment, any of the above manufacturing methods (I) to (V) is preferred.

[0141] The resin fine particles (B) are preferably used as an aqueous dispersion.

[0142] 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, buffers, protective colloids, etc. These may be used individually or in combination of two or more.

[0143] The aqueous medium used in the aqueous dispersion is not particularly limited as long as it is a liquid that requires water, such as an aqueous solution containing water.

[0144] [Inorganic external additives] The inorganic additive may be placed on the surface of the toner matrix particles or on the surface of the resin microparticles. That is, the inorganic additive may be placed on the surface of the toner matrix particles or on the surface of the resin microparticles that are present between the resin microparticles.

[0145] Inorganic additives consist of a metal element oxide coated with a metal element hydroxide.

[0146] There are no particular restrictions on the oxides of metal elements, and they can be appropriately selected depending on the purpose. Examples include silicon dioxide (silica), titanium dioxide, aluminum oxide, iron oxide, copper oxide, zinc oxide, tin oxide, chromium oxide, cerium oxide, antimony trioxide, magnesium oxide, and zirconium oxide. Among these, silica and titanium dioxide are preferred from the viewpoint of adhesion to toner matrix particles and resin fine particles, with silica being more preferred.

[0147] Examples of metal element hydroxides include aluminum hydroxide, zinc hydroxide, and magnesium hydroxide. These may be used individually or in combination.

[0148] The outermost surface of the inorganic external additive is preferably coated with an alkylsilane by surface treatment with a silane coupling agent containing alkylsilanes such as isobutylsilane, methyltrimethoxysilane, methyltriethoxysilane, and octyltrimethoxysilane.

[0149] Hydrophobized oxide nanoparticles, hydrophobized silica nanoparticles, hydrophobized titanium oxide nanoparticles, and hydrophobized aluminum oxide nanoparticles can be obtained by treating hydrophilic nanoparticles with a silane coupling agent containing alkylsilane.

[0150] The average particle size of the inorganic additive is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 1 nm to 200 nm, and more preferably 10 nm to 150 nm. If the average particle size of the inorganic additive is within the above preferred range, the inorganic additive will not be easily embedded in the toner matrix particles, allowing the inorganic additive to function effectively, and it will also be possible to suppress uneven scratching of the photoreceptor surface.

[0151] There are no particular restrictions on the content of the inorganic external additive, and it can be appropriately selected depending on the purpose, but it is preferably 0.5 to 6.0 parts by mass, and more preferably 1.0 to 4.0 parts by mass, per 100 parts by mass of toner matrix particles.

[0152] <Inorganic fillers> Toner matrix particles are manufactured by adding inorganic fillers to toner matrix particles. While not particularly limited, one or more inorganic fillers can be selected from calcium carbonate, kaolin clay, talc, barium sulfate, etc. These may be used individually or in combination. These inorganic fillers may be surface-treated with silane coupling agents, surfactants, and metal soaps, or they may be used after being adjusted to a desired particle size distribution through classification or other means.

[0153] In addition to the above, layered inorganic minerals are also preferred as inorganic fillers. Furthermore, layered inorganic minerals modified with organic ions are preferred. Layered inorganic minerals are inorganic minerals made up of layers several nanometers thick stacked on top of each other, and modification with organic ions means introducing organic ions into the ions present between these layers.

[0154] Known layered inorganic minerals include the smectite group (montmorillonite, saponite, etc.), the kaolin group (kaolinite, etc.), magadhiite, and kanemite. Modified layered inorganic minerals have high hydrophilicity due to their modified layered structure. Therefore, if layered inorganic minerals are used in toners that are dispersed and granulated in an aqueous medium without modification, the layered inorganic minerals migrate into the aqueous medium, preventing the toner from being deformed. However, modification increases hydrophilicity, and these modified layered inorganic minerals become finer and deformed during toner production, becoming particularly abundant on the surface of the toner particles. They can be uniformly dispersed throughout the toner matrix particles, performing a charge regulation function and contributing to low-temperature fixing. In this case, the content of modified layered inorganic minerals in the toner material is preferably 0.2% to 1.5% by mass.

[0155] Modified layered inorganic minerals are preferably those with a smectite-based basic crystal structure that have been modified with organic cations. Furthermore, metal anions can be introduced by substituting some of the divalent metals in the layered inorganic mineral with trivalent metals. However, since the introduction of metal anions increases hydrophilicity, layered inorganic compounds in which at least some of the metal anions have been modified with organic anions are preferable.

[0156] Examples of organic ion modifiers for layered inorganic minerals, in which at least some of the ions contained in the layered inorganic mineral are modified with organic ions, include quaternary alkylammonium salts, phosphonium salts, and imidazolium salts, but quaternary alkylammonium salts are preferred. Examples of quaternary alkylammonium salts include trimethylstearylammonium, dimethylstearylbenzylammonium, dimethyloctadecylammonium, and oleylbis(2-hydroxyethyl)methylammonium.

[0157] Examples of organic ion modifiers include sulfates, sulfonates, carboxylates, or phosphates containing branched, unbranched, or cyclic alkyl (C1-C44), alkenyl (C1-C22), alkoxy (C8-C32), hydroxyalkyl (C2-C22), ethylene oxide, propylene oxide, etc. Carboxylic acids with an ethylene oxide skeleton are preferred.

[0158] By modifying at least a portion of the layered inorganic mineral with organic ions, it is possible to obtain a layered inorganic mineral with appropriate hydrophobicity, a non-Newtonian viscosity in the oil phase containing the toner composition and / or toner composition precursor, and to modify the shape of the toner. In this case, the content of the layered inorganic mineral modified with organic ions in the toner material is preferably 0.2% to 1.5% by mass.

[0159] Layered inorganic minerals partially modified with organic ions can be selected as appropriate, but examples include montmorillonite, bentonite, hectorite, attapulgite, sepiolite, and mixtures thereof. Among these, montmorillonite or bentonite containing Al is preferred because Al is effective in improving the charging capacity.

[0160] Commercially available layered inorganic minerals partially modified with organic cations include quaternium-18 bentonite such as Bentone 3, Bentone 38, Bentone 38V (all manufactured by Rheox), Thixogel VP (manufactured by United Catalyst), Kraton 34, Kraton 40, Kraton XL (all manufactured by Southern Clay); stearalkonium bentonite such as Bentone 27 (manufactured by Rheox), Thixogel LG (manufactured by United Catalyst), Kraton AF, Kraton APA (both manufactured by Southern Clay); and quaternium-18 / benzalkonium bentonite such as Kraton HT, Kraton PS (both manufactured by Southern Clay). Kraton AF and Kraton APA are particularly preferred. Furthermore, as a layered inorganic mineral partially modified with organic anions, DHT-4A (manufactured by Kyowa Chemical Industry Co., Ltd.) modified with an organic anion represented by the following general formula (3) is particularly preferred. Examples of the general formula (3) below include Hythenol 330T (manufactured by Daiichi Kogyo Seiyaku Co., Ltd.). R1(OR2)nOSO3M...General formula (3) (In formula (3), R1 represents an alkyl group having 13 carbon atoms, R2 represents an alkylene group having 2 to 6 carbon atoms, n represents an integer from 2 to 10, and M represents a monovalent metallic element.)

[0161] <Other ingredients> Other components are not particularly limited and can be appropriately selected depending on the purpose. Examples include polymers having sites that can react with reactive hydrogen group-containing compounds, reactive hydrogen group-containing compounds, charge control agents, external additives, flow improvers, cleaning improvers, magnetic materials, etc.

[0162] [Release agent] There are no particular restrictions on the release agent; it can be appropriately selected from known ones.

[0163] Examples of release agents for waxes and waxes include plant-based waxes such as carnauba wax, cotton wax, wood wax, and rice wax; animal-based waxes such as beeswax and lanolin; mineral waxes such as ozokerite and cerucine; and petroleum waxes such as paraffin, microcrystalline, and petrolatum.

[0164] In addition to these natural waxes, other examples include Fischer-Tropsch wax, synthetic hydrocarbon waxes such as polyethylene and polypropylene, and synthetic waxes such as esters, ketones, and ethers.

[0165] Furthermore, fatty acid amide compounds such as 12-hydroxystearic acid amide, stearic acid amide, phthalimide anhydride, and chlorinated hydrocarbons may be used; 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-ethyl methacrylate); and crystalline polymers having long alkyl groups in their side chains may also be used.

[0166] Among these, hydrocarbon waxes such as paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyethylene wax, and polypropylene wax are preferred.

[0167] There are no particular restrictions on the melting point of the release agent, and it can be appropriately selected depending on the purpose, but a melting point of 60°C or higher and less than 95°C is preferred.

[0168] As a release agent, a hydrocarbon wax with a melting point of 60°C or higher and less than 95°C is more preferable. Since such a release agent can act effectively as a release agent between the fixing roller and the toner interface, high-temperature offset resistance can be improved without applying a release agent such as oil to the fixing roller.

[0169] In particular, hydrocarbon waxes are preferable because they have almost no compatibility with the polyester resin A and can function independently of each other, thus not impairing the softening effect as a binder resin for crystalline polyester resin or the offsetting effect of the mold release agent.

[0170] If the release agent has a melting point of 60°C or higher, it will not melt easily at low temperatures, thus maintaining the heat resistance of the toner. If the release agent has a melting point of less than 95°C, sufficient melting of the release agent due to heating during fixing will be achieved, resulting in sufficient offset.

[0171] There are no particular restrictions on the amount of release agent, and it can be appropriately selected depending on the purpose, but preferably it is 2 to 10 parts by mass, and more preferably 3 to 8 parts by mass, per 100 parts by mass of toner. If the amount of release agent is 2 parts by mass or more, high temperature offset resistance and low temperature fixing performance can be achieved during fixing, and if it is 10 parts by mass or less, heat resistance for storage can be maintained and image fogging can be made less likely. If the amount of release agent is within the more preferable range, it is advantageous in terms of improving image quality and fixing stability.

[0172] [Polymers (prepolymers) having sites that can react with active hydrogen group-containing compounds] There are no particular limitations on the polymer (sometimes referred to as "prepolymer") having a site that can react with an active hydrogen group-containing compound, and it can be appropriately selected depending on the purpose. Examples include polyol resins, polyacrylic resins, polyester resins, epoxy resins, and their derivatives. These may be used individually or in combination of two or more. Among these, polyester resins are preferred in terms of high fluidity and transparency when melted.

[0173] The reactive sites of the prepolymer that can react with active hydrogen group-containing compounds include isocyanate groups, epoxy groups, carboxyl groups, and functional groups represented by -COCl. These may be used individually or in combination of two or more. Among these, isocyanate groups are preferred.

[0174] There are no particular restrictions on the prepolymer, and it can be appropriately selected depending on the purpose. However, polyester resins having isocyanate groups that can generate urea bonds are preferred because they allow for easy adjustment of the molecular weight of the polymer component and ensure good oil-free low-temperature fixing characteristics in dry toners, particularly in the absence of a release oil application mechanism to the fixing heating medium.

[0175] [Active hydrogen group-containing compound] The active hydrogen group-containing compound acts as an extension agent, crosslinking agent, etc., when a polymer having a site that can react with the active hydrogen group-containing compound undergoes an extension reaction, crosslinking reaction, etc., in an aqueous medium.

[0176] There are no particular restrictions on the active hydrogen group, and it can be appropriately selected depending on the purpose. Examples include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, etc. These may be used individually or in combination of two or more.

[0177] There are no particular restrictions on the active hydrogen group-containing compound, and it can be appropriately selected depending on the purpose. However, when the polymer 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 be increased in molecular weight through extension reactions, crosslinking reactions, etc., with the polyester resin.

[0178] There are no particular restrictions on the amines used, 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 and small amounts of trivalent or higher amines are preferred.

[0179] There are no particular restrictions on the diamine, and it can be appropriately selected depending on the purpose. Examples include aromatic diamines, alicyclic diamines, and aliphatic diamines.

[0180] There are no particular restrictions on the aromatic diamine, and it can be appropriately selected depending on the purpose. Examples include phenylenediamine, diethyltoluenediamine, and 4,4'-diaminodiphenylmethane.

[0181] There are no particular restrictions on the alicyclic diamine, and it can be appropriately selected depending on the purpose. Examples include 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diaminocyclohexane, and isophorone diamine.

[0182] There are no particular restrictions on the aliphatic diamine, and it can be appropriately selected depending on the purpose. Examples include ethylenediamine, tetramethylenediamine, and hexamethylenediamine.

[0183] There are no particular restrictions on the amines with a valency of 3 or higher; they can be appropriately selected depending on the purpose. Examples include diethylenetriamine and triethylenetetramine.

[0184] There are no particular restrictions on the amino alcohol used; it can be appropriately selected depending on the purpose. Examples include ethanolamine and hydroxyethylaniline.

[0185] There are no particular restrictions on the amino mercaptan, and it can be appropriately selected depending on the purpose. Examples include aminoethyl mercaptan and aminopropyl mercaptan.

[0186] There are no particular restrictions on the amino acids used; they can be appropriately selected depending on the purpose. Examples include aminopropionic acid and aminocaproic acid.

[0187] There are no particular restrictions on the type of amino group that can be blocked, and they 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.

[0188] -Polyester resin containing isocyanate groups- There are no particular limitations on the polyester resin containing isocyanate groups (hereinafter sometimes referred to as "polyester prepolymer having isocyanate groups"), and it can be appropriately selected depending on the purpose. Examples include the reaction product of a polyester resin having active hydrogen groups obtained by polycondensation of a polyol and a polycarboxylic acid, and a polyisocyanate.

[0189] -Polyol- There are no particular restrictions on the polyol, and it 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.

[0190] There are no particular restrictions on the diol, and it can be appropriately selected depending on the purpose. Examples include alkylene glycols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, and 1,6-hexanediol; diols having an oxyalkylene group such as diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol; alicyclic diols such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A; alicyclic diols to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide have been added; bisphenols such as bisphenol A, bisphenol F, and bisphenol S; and alkylene oxide adducts of bisphenols to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide have been added. There are no particular restrictions on the number of carbon atoms in the alkylene glycol, and it can be appropriately selected depending on the purpose, but 2 to 12 is preferred.

[0191] Among these, alkylene glycols having 2 to 12 carbon atoms and alkylene oxide adducts of bisphenols are preferred, and a mixture of alkylene oxide adducts of bisphenols, alkylene oxide adducts of bisphenols, and alkylene glycols having 2 to 12 carbon atoms is more preferred.

[0192] There are no particular restrictions on alcohols with a valency of three or higher; they can be appropriately selected depending on the purpose. Examples include aliphatic alcohols with a valency of three or higher, polyphenols with a valency of three or higher, and alkylene oxide adducts of polyphenols with a valency of three or higher.

[0193] There are no particular restrictions on trivalent or higher aliphatic alcohols, and they can be appropriately selected depending on the purpose. Examples include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol.

[0194] There are no particular restrictions on the use of trivalent or higher polyphenols; they can be appropriately selected depending on the purpose. Examples include trisphenol PA, phenol novolac, and cresol novolac.

[0195] Examples of alkylene oxide adducts of polyphenols with a valency of three or higher include those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to polyphenols with a valency of three or higher.

[0196] When using a mixture of a diol and the aforementioned trivalent or higher alcohol, there are no particular restrictions on the mass ratio of the trivalent or higher alcohol to the 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.

[0197] -Polycarboxylic acid- There are no particular restrictions on the polycarboxylic acid, and it 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.

[0198] There are no particular restrictions on the dicarboxylic acid, and it can be appropriately selected depending on the purpose. Examples include divalent alkanic acid, divalent alkenic acid, and aromatic dicarboxylic acid.

[0199] There are no particular restrictions on the divalent alkanic acid, and it can be appropriately selected depending on the purpose. Examples include succinic acid, adipic acid, and sebacic acid.

[0200] There are no particular restrictions on the divalent alkenoic acid, and it can be appropriately selected depending on the purpose, but divalent alkenoic acid having 4 to 20 carbon atoms is preferred. There are no particular restrictions on the divalent alkenoic acid having 4 to 20 carbon atoms, and it can be appropriately selected depending on the purpose, for example, maleic acid, fumaric acid, etc.

[0201] There are no particular restrictions on the aromatic dicarboxylic acid, and it 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, and the like.

[0202] There are no particular restrictions on the trivalent or higher carboxylic acid, and it can be appropriately selected depending on the purpose. Examples include trivalent or higher aromatic carboxylic acids.

[0203] 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.

[0204] As the polycarboxylic acid, an acid anhydride or lower alkyl ester of any of the following can 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.

[0205] There are no particular restrictions on the lower alkyl esters, and they can be appropriately selected depending on the purpose. Examples include methyl esters, ethyl esters, isopropyl esters, and the like.

[0206] When a dicarboxylic acid and the aforementioned trivalent or higher carboxylic acid are used in mixture, there are no particular restrictions on the mass ratio of the trivalent or higher carboxylic acid to the 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.

[0207] When polycondensing a polyol and a 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, 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.

[0208] 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 above content is 0.5% by mass or more, high temperature offset resistance can be maintained and both heat resistance for toner storage and low temperature fixing can be achieved, and when it is 40% by mass or less, low temperature fixing can be maintained.

[0209] -Polyisocyanate- There are no particular restrictions on the polyisocyanates, and they 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.

[0210] There are no particular restrictions on the aliphatic diisocyanates used, and they 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.

[0211] 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.

[0212] There are no particular restrictions on the aromatic diisocyanates, and they 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.

[0213] There are no particular restrictions on the aromatic aliphatic diisocyanate, and it can be appropriately selected depending on the purpose. Examples include α,α,α',α'-tetramethylxylylene diisocyanate.

[0214] There are no particular restrictions on the isocyanurates used, 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.

[0215] When reacting polyisocyanate with a polyester resin having hydroxyl groups, there are no particular restrictions on the equivalent ratio of 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 3 is particularly preferred. If the equivalent ratio is 1 or higher, offset resistance can be maintained, and if it is 5 or lower, low-temperature fixability can be maintained.

[0216] 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. If the above content is 0.5% by mass or more, high temperature offset resistance can be maintained, and if it is 40% by mass or less, low temperature fixability can be maintained.

[0217] There are no particular restrictions on the average number of isocyanate groups per molecule of a polyester prepolymer having isocyanate groups, and it can be appropriately selected depending on the purpose, but it is preferably 1 or more, more preferably 1.2 to 5, and particularly preferably 1.5 to 4. When the average number is 1 or more, the decrease in molecular weight of the urea-modified polyester resin is suppressed and the high-temperature offset resistance can be maintained.

[0218] The polyhydric alcohol component contains 50 mol% or more of propylene oxide adducts of bisphenols, and the mass ratio of the polyester prepolymer having isocyanate groups to the polyester resin having a specific hydroxyl value and acid value is not particularly limited and can be appropriately selected depending on the purpose, but is preferably greater than 5 / 95 and less than 25 / 75, and more preferably between 10 / 90 and 25 / 75. When the mass ratio exceeds 5 / 95, high temperature offset resistance can be maintained, and when it is less than 25 / 75, low temperature fixability and image gloss can be exhibited.

[0219] [Static Control Agent] There are no particular restrictions on the charge control agent, and it 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. Specifically, examples include the nigrosine-based dye Bontron 03, the quaternary ammonium salt Bontron P-51, the metal-containing azo dye Bontron S-34, the oxynaphthoic acid-based metal complex E-82, the salicylic acid-based metal complex E-84, the phenolic condensate E-89 (all manufactured by Orient Chemical Industry Co., Ltd.), the quaternary ammonium salt molybdenum complexes TP-302 and TP-415 (both manufactured by Hodogaya Chemical Co., Ltd.), LRA-901, the boron complex LR-147 (manufactured by Nippon Carlit Co., Ltd.), copper phthalocyanine, perylene, quinacridone, azo pigments, and other polymer compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts.

[0220] There are no particular restrictions on the content of the charge control agent, and it can be appropriately selected according to the purpose, but preferably 0.1 to 10 parts by mass, and more preferably 0.2 to 5 parts by mass, per 100 parts by mass of toner. When the content of the charge control agent is 10 parts by mass or less, the charge of the toner is not too high, and the effect of the main charge control agent can be maintained, thereby suppressing the increase in electrostatic attraction force with the developing roller and maintaining the fluidity of the developer and the image density. These charge control agents can be dissolved and dispersed after melting and kneading together with the masterbatch and resin, or they can be added when dissolving and dispersing directly in an organic solvent, or they can be immobilized on the toner surface after the toner matrix particles have been formed.

[0221] There are no particular restrictions on the acid value of the toner, and it can be appropriately selected according to the purpose. However, from the standpoint of controlling low-temperature fixing properties (lower fixing temperature) and hot offset generation temperature, an acid value of 0.5 mg KOH / g to 40 mg KOH / g is preferable. When the acid value is 0.5 mg KOH / g or higher, the dispersion stability due to the base during manufacturing is improved, and when a prepolymer is used, the tendency for extension reactions and / or crosslinking reactions to proceed is suppressed, and manufacturing stability can be maintained. When the acid value is 40 mg KOH / g or lower, when a prepolymer is used, the extension reactions and / or crosslinking reactions are sufficient, and high-temperature offset resistance can be exhibited.

[0222] There are no particular restrictions on the glass transition temperature (Tg) of the toner, and it can be appropriately selected depending on the purpose. However, it is preferable that the glass transition temperature (Tg1st) calculated in the first heating step of the DSC measurement be 45°C or higher and less than 65°C, and more preferably 50°C to 60°C. This allows for low-temperature fixability, heat resistance, and high durability. If Tg1st is 45°C or higher, blocking in the developing machine and filming on the photoreceptor are suppressed, and if it is 65°C or lower, the decrease in low-temperature fixability is suppressed.

[0223] Furthermore, in DSC measurement of toner, the glass transition temperature (Tg2nd) calculated during the second heating step is preferably between 20°C and 40°C. If Tg2nd is 20°C or higher, blocking and filming on the photoreceptor within the developing machine are suppressed, and if it is 40°C or lower, the decrease in low-temperature fixability is suppressed.

[0224] There are no particular restrictions on the volume-average particle size of the toner, and it can be appropriately selected depending on the purpose, but it is preferably 3 μm to 7 μm. Furthermore, the ratio of the volume-average particle size to the number-average particle size is preferably 1.2 or less. In addition, it is preferable to contain 1% to 10% of a component with a volume-average particle size of 2 μm or less.

[0225] <<Method for measuring acid value and hydroxyl value>> The hydroxyl value can be measured using a method compliant with JIS K0070-1966. Specifically, first, 0.5 g of the sample is accurately weighed into a 100 mL volumetric flask, and 5 mL of acetylation reagent is added. Next, the flask is heated in a 100 ± 5 °C bath for 1 to 2 hours, then removed from the bath and allowed to cool. Water is then added and shaken to decompose the acetic anhydride. Next, to completely decompose the acetic anhydride, the flask is heated again in a bath for 10 minutes or more, allowed to cool, and then the flask walls are thoroughly washed with an organic solvent. Furthermore, the hydroxyl value is measured at 23 °C using a potentiometric automatic titrator DL-53 Titrator (Mettler-Toledo) and electrode DG113-SC (Mettler-Toledo), and the analysis is performed using the analysis software LabX Light Version 1.00.000. A mixed solvent of 120 mL of toluene and 30 mL of ethanol is used for calibration of the instrument. The measurement conditions are as follows:

[0226] [Measurement conditions] • Stirring Speed[%]:25 Time[s]:15 ·EV titration curve (EQP titration) Titrant / Sensor Titrant:CH3ONa Concentration[mol / L]:0.1 Sensor:DG115 Unit of measurement:mV Predispensing to volume Volume[mL]:1.0 Wait time[s]:0 Titrant addition:Dynamic dE(set)[mV]:8.0 dV(min)[mL]:0.03 dV(max)[mL]:0.5 Measure mode:Equilibrium controlled dE[mV]:0.5 dt[s]:1.0 t(min)[s]:2.0 t(max)[s]:20.0 Recognition Threshold:100.0 Steepest jump:only No Range:No Tendency:None Termination at maximum volume[mL]:10.0 at potential:No at slope:No after number EQPs:Yes n=1 comb.termination conditions:No Evaluation Procedure:Standard Potential1:No Potential2:No Stop for reevaluation:No

[0227] The acid value can be measured using a method compliant with JIS K0070-1992. Specifically, first, 0.5 g of the sample (0.3 g for ethyl acetate soluble portion) is added to 120 mL of toluene and dissolved by stirring at 23°C for approximately 10 hours. Next, 30 mL of ethanol is added to prepare the sample solution. If the sample does not dissolve, solvents such as dioxane or tetrahydrofuran can be used. Furthermore, the acid value is measured at 23°C using a potentiometric automatic titrator DL-53 Titrator (Mettler-Toledo) and electrode DG113-SC (Mettler-Toledo), and analyzed using the analysis software LabX Light Version 1.00.000. A mixed solvent of 120 mL of toluene and 30 mL of ethanol is used for instrument calibration. The measurement conditions are the same as those for the hydroxyl value described above.

[0228] The acid value can be measured as described above. Specifically, it is measured by titrating with a pre-standardized 0.1N potassium hydroxide / alcohol solution, and the acid value is calculated from the titration volume using the following formula: Acid value [mgKOH / g] = Titration volume [mL] × N × 56.1 [mg / mL] / Sample mass [g] (where N is the factor for the 0.1N potassium hydroxide / alcohol solution).

[0229] <<Method for measuring melting point and glass transition temperature (Tg)>> The melting point and glass transition temperature (Tg) can be measured, for example, using a DSC system (differential scanning calorimeter) ("DSC-60", manufactured by Shimadzu Corporation). Specifically, the melting point and glass transition temperature of the target sample can be measured by the following procedure.

[0230] First, approximately 5.0 mg of the target sample is placed in an aluminum sample container, which is then placed on a holder unit and set in an electric furnace. Next, under a nitrogen atmosphere, it is heated from 0°C to 150°C at a heating rate of 10°C / min. After that, it is cooled from 150°C to 0°C at a cooling rate of 10°C / min, and then heated again to 150°C at a heating rate of 10°C / min, and the DSC curve is measured using a differential scanning calorimeter ("DSC-60", manufactured by Shimadzu Corporation).

[0231] From the obtained DSC curve, using the analysis program "endothermic shoulder temperature" in the DSC-60 system, select the DSC curve during the first heating, and the glass transition temperature of the target sample during the first heating can be obtained. Also, using the "endothermic shoulder temperature", select the DSC curve during the second heating, and the glass transition temperature of the target sample during the second heating can be obtained.

[0232] Also, from the obtained DSC curve, using the analysis program "endothermic peak temperature" in the DSC-60 system, select the DSC curve during the first heating, and the melting point of the target sample during the first heating can be obtained. Also, using the "endothermic peak temperature", select the DSC curve during the second heating, and the melting point of the target sample during the second heating can be obtained.

[0233] In this embodiment, when using toner as the target sample, the glass transition temperature during the first heating is designated as Tg_{1st}, and the glass transition temperature during the second heating is designated as Tg_{2nd}. [[ID=ll]]

[0234] Also, in this embodiment, the melting point and Tg of each constituent component during the second heating are taken as the melting point and Tg of each target sample.

[0235] <<Measurement Method of Particle Size Distribution>> The volume average particle diameter (D4), number average particle diameter (Dn), and their ratio (D4 / Dn) of the toner can be measured using, for example, a Coulter Counter TA-II, Coulter Multisizer II (both manufactured by Coulter Corporation), etc. In the present invention, the Coulter Multisizer II was used. The measurement method will be described below.

[0236] First, 0.1 mL to 5 mL of a surfactant (preferably polyoxyethylene alkyl ether (a nonionic surfactant)) is added as a dispersant to 100 mL to 150 mL of electrolytic aqueous solution. Here, the electrolytic aqueous solution is a 1% NaCl aqueous solution prepared using primary sodium chloride; for example, ISOTON-II (manufactured by Coulter) can be used. Next, 2 mg to 20 mg of the sample to be measured is added. The electrolytic aqueous solution in which the sample is suspended is dispersed in an ultrasonic disperser for about 1 to 3 minutes. Then, using the aforementioned measuring device with a 100 μm aperture, the volume and number of toner particles or toner are measured, and the volume distribution and number distribution are calculated. From the obtained distribution, the volume-average particle size (D4) and number-average particle size (Dn) of the toner can be determined.

[0237] The 13 channels used are: 2.00 μm or more and less than 2.52 μm; 2.52 μm or more and less than 3.17 μm; 3.17 μm or more and less than 4.00 μm; 4.00 μm or more and less than 5.04 μm; 5.04 μm or more and less than 6.35 μm; 6.35 μm or more and less than 8.00 μm; 8.00 μm or more and less than 10.08 μm; 10.08 μm or more and less than 12.70 μm; 12.70 μm or more and less than 16.00 μm; 16.00 μm or more and less than 20.20 μm; 20.20 μm or more and less than 25.40 μm; 25.40 μm or more and less than 32.00 μm; and 32.00 μm or more and less than 40.30 μm.

[0238] [External Additives] In addition to oxide microparticles, inorganic microparticles and hydrophobically treated inorganic microparticles can be used as external additives. The average particle size of the hydrophobically treated primary particles is preferably 1 nm to 200 nm, and inorganic microparticles of 10 nm to 150 nm are more preferable. Furthermore, it is preferable to include at least one type of inorganic microparticle with an average particle size of 30 nm or less, and at least one type of inorganic microparticle with an average particle size of 50 nm or more. When the average particle size of the inorganic microparticles is 50 nm or more, they are more easily blocked by the blade, improving filming and cleaning. The specific surface area measured by the BET method is 20 m². 2 / g~500m2 It is preferable that it be / g.

[0239] There are no particular restrictions on external additives, and they can be appropriately selected depending on the purpose. Examples include silica nanoparticles, hydrophobic silica, fatty acid metal salts (e.g., zinc stearate, aluminum stearate, etc.), metal oxides (e.g., titanium dioxide, aluminum oxide, tin oxide, antimony oxide, etc.), fluoropolymers, etc.

[0240] There are no particular restrictions on the content of external additives, and they can be appropriately selected depending on the purpose, but preferably 0.5 to 6.0 parts by mass, and more preferably 1.0 to 4.0 parts by mass, per 100 parts by mass of toner matrix particles.

[0241] (Other external additives) Other additives include titanium dioxide nanoparticles and aluminum oxide nanoparticles. Examples of titanium dioxide nanoparticles 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, MT-150A (all manufactured by Teika Co., Ltd.), etc.

[0242] 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.), IT-S (manufactured by Ishihara Sangyo Co., Ltd.), and others.

[0243] Hydrophobized oxide nanoparticles, hydrophobized silica nanoparticles, hydrophobized titanium oxide nanoparticles, and hydrophobized aluminum oxide nanoparticles can be obtained by treating hydrophilic nanoparticles with silane coupling agents such as methyltrimethoxysilane, methyltriethoxysilane, and octyltrimethoxysilane. Alternatively, if necessary, silicone oil-treated oxide nanoparticles and inorganic nanoparticles obtained by treating silicone oil with heat to convert it into inorganic nanoparticles are also suitable.

[0244] Examples of silicone oils that can be used include dimethyl silicone oil, methylphenyl silicone oil, chlorophenyl silicone oil, methylhydrogen silicone oil, alkyl-modified silicone oil, fluorine-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, epoxy-polyether-modified silicone oil, phenol-modified silicone oil, carboxyl-modified silicone oil, mercapto-modified silicone oil, acrylic-methacrylic-modified silicone oil, and α-methylstyrene-modified silicone oil.

[0245] Examples of inorganic fine particles include silica, aluminum oxide, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, copper oxide, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, silica and titanium dioxide are particularly preferred.

[0246] There are no particular restrictions on the content of external additives, and they can be appropriately selected depending on the purpose, but a content of 0.1% to 5% by mass relative to the toner is preferred, and 0.3% to 3% by mass is more preferred.

[0247] There are no particular restrictions on the average particle size of the primary inorganic fine particles, and they can be appropriately selected depending on the purpose. However, a size of 200 nm or less is preferred, and a size of 10 nm to 100 nm is more preferred. If the particle size is smaller than this range, the inorganic fine particles become embedded in the toner, and their function is not effectively exerted. Conversely, if the particle size is larger than this range, it is undesirable as it can unevenly damage the surface of the photoreceptor.

[0248] [Flow improver] The fluidity improver is not particularly limited as long as it can be surface-treated to increase hydrophobicity and prevent deterioration of fluidity and electrostatic properties even under high humidity conditions, and can be appropriately selected according to the purpose. Examples of fluidity improvers include silane coupling agents, silylation agents, silane coupling agents having alkyl fluoride, organic titanate coupling agents, aluminum coupling agents, silicone oil, and modified silicone oil. It is particularly preferable to surface-treat silica and titanium dioxide with such fluidity improvers and use them as hydrophobic silica and hydrophobic titanium dioxide.

[0249] [Cleaning performance enhancer] The cleaning agent is not particularly limited as long as it is added to the toner to remove residual developer after transfer from the photoreceptor and primary transfer medium, and can be appropriately selected according to 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. Polymer microparticles with a relatively narrow particle size distribution are preferred, and those with a volume average particle size of 0.01 μm to 1 μm are preferred.

[0250] [Magnetic material] There are no particular restrictions on the magnetic material, and it can be appropriately selected depending on the purpose. Examples include iron powder, magnetite, and ferrite. Among these, white materials are preferred in terms of color.

[0251] <Toner manufacturing method> The method for producing toner is not particularly limited and can be appropriately selected according to the purpose. However, the toner is preferably granulated by dispersing an oil phase containing at least an amorphous polyester resin, a crystalline polyester resin, a release agent, and a colorant in an aqueous medium.

[0252] As an example of such a method for producing toner, a known dissolution-suspension method can be mentioned.

[0253] Also, as another example of the method for producing toner, a method for forming toner mother particles while generating a product (hereinafter sometimes referred to as an "adhesive base material") produced by an elongation reaction and / or a cross-linking reaction between an active hydrogen group-containing compound and a polymer having a site capable of reacting with the active hydrogen group-containing compound is shown below. In such a method, preparation of an aqueous medium, preparation of an oil phase containing toner materials, emulsification or dispersion of the toner materials, removal of an organic solvent, etc. are carried out.

[0254] [Preparation of Aqueous Medium (Aqueous Phase)] The preparation of the aqueous medium can be carried out, for example, by dispersing resin particles in the aqueous medium. The addition amount of the resin particles in the aqueous medium is not particularly limited and can be appropriately selected according to the purpose, but 0.5 mass% to 10 mass% is preferable.

[0255] The resin particles are not particularly limited and can be appropriately selected according to the purpose. Examples thereof include surfactants, poorly water-soluble inorganic compound dispersants, polymer-based protective colloids, etc. These may be used alone or in combination of two or more. Among these, surfactants are preferable.

[0256] The aqueous medium is not particularly limited and can be appropriately selected according to the purpose. Examples thereof include water, solvents miscible with water, mixtures thereof, etc. These may be used alone or in combination of two or more. Among these, water is preferable.

[0257] 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.

[0258] There are no particular restrictions on the alcohol used; it can be selected appropriately depending on the purpose. Examples include methanol, isopropanol, and ethylene glycol.

[0259] There are no particular restrictions on the lower ketones used; they can be appropriately selected depending on the purpose. Examples include acetone and methyl ethyl ketone.

[0260] [Preparation of the oil phase] The oil phase containing toner material can be prepared by dissolving or dispersing toner material, which includes an active hydrogen group-containing compound, a polymer having a site that can react with the active hydrogen group-containing compound, a crystalline polyester resin, an amorphous polyester resin, a mold release agent, a hybrid resin, and a colorant, in an organic solvent.

[0261] There are no particular restrictions on the organic solvent, and it can be appropriately selected depending on the purpose, but organic solvents with a boiling point of less than 150°C are preferred because they are easy to remove.

[0262] There are no particular restrictions on organic solvents with a boiling point below 150°C, and they can be appropriately selected depending on the purpose. Examples include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, methyl isobutyl ketone, etc. These may be used individually or in combination of two or more. Among these, ethyl acetate, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, carbon tetrachloride, etc. are preferred, with ethyl acetate being more preferred.

[0263] [Emulsification or dispersion] The emulsification or dispersion of toner material can be carried out by dispersing an oil phase containing the toner material in an aqueous medium. Furthermore, during the emulsification or dispersion of the toner material, an adhesive substrate is generated by causing an extension reaction and / or crosslinking reaction between an active hydrogen group-containing compound and a polymer having a site reactive to the active hydrogen group-containing compound.

[0264] The adhesive substrate may be produced by emulsifying or dispersing an oil phase containing a polymer that is reactive to active hydrogen groups, such as a polyester prepolymer having isocyanate groups, together with a compound containing active hydrogen groups, such as amines, in an aqueous medium, and then causing an extension reaction and / or crosslinking reaction between the two in the aqueous medium; or by emulsifying or dispersing an oil phase containing toner material in an aqueous medium to which a compound containing active hydrogen groups has been previously added, and then causing an extension reaction and / or crosslinking reaction between the two in the aqueous medium; or by emulsifying or dispersing an oil phase containing toner material in an aqueous medium, then adding a compound containing active hydrogen groups, and then causing an extension reaction and / or crosslinking reaction between the two from the particle interface in the aqueous medium. When the extension reaction and / or crosslinking reaction is carried out from the particle interface, a urea-modified polyester resin may be preferentially formed on the surface of the toner produced, and a concentration gradient of urea-modified polyester resin can be provided in the toner.

[0265] There are no particular restrictions on the reaction conditions (reaction time, reaction temperature) for producing the adhesive substrate, and they can be appropriately selected depending on the combination of the active hydrogen group-containing compound and the polymer having a site that can react with the active hydrogen group-containing compound.

[0266] There are no particular restrictions on the reaction time, and it can be selected as appropriate depending on the purpose, but 10 minutes to 40 hours is preferred, and 2 hours to 24 hours is more preferred.

[0267] There are no particular restrictions on the reaction temperature, and it can be appropriately selected depending on the purpose, but 0°C to 150°C is preferred, and 40°C to 98°C is more preferred.

[0268] There are no particular limitations on the method for stably forming a dispersion containing a polymer having a site that can react with an active hydrogen group-containing compound, such as a polyester prepolymer having an isocyanate group, in an aqueous medium, and a suitable method can be selected depending on the purpose. For example, such a method involves adding an oil phase prepared by dissolving or dispersing toner material in a solvent to an aqueous medium phase and dispersing it by shear force.

[0269] There are no particular restrictions on the type of disperser used for dispersion, and they can be appropriately selected according to the purpose. Examples include low-speed shear dispersers, high-speed shear dispersers, friction dispersers, high-pressure jet dispersers, ultrasonic dispersers, etc. Among these, high-speed shear dispersers are preferred because they can control the particle size of the dispersion (oil droplets) to 2 μm to 20 μm.

[0270] When using a high-speed shear disperser, conditions such as rotation speed, dispersion time, and dispersion temperature can be appropriately selected according to the purpose.

[0271] There are no particular restrictions on rotational speed, and it can be selected appropriately depending on the purpose, but 1,000 rpm to 30,000 rpm is preferred, and 5,000 rpm to 20,000 rpm is more preferred.

[0272] There are no particular restrictions on the distribution time, and it can be selected as appropriate depending on the purpose, but for batch processing, 0.1 to 5 minutes is preferable.

[0273] There are no particular restrictions on the dispersion temperature, and it can be appropriately selected depending on the purpose, but under pressure, 0°C to 150°C is preferred, and 40°C to 98°C is more preferred. Generally, dispersion is easier at higher dispersion temperatures.

[0274] There are no particular restrictions on the amount of aqueous medium used when emulsifying or dispersing the toner material, and it can be appropriately selected according to the purpose. However, 50 to 2,000 parts by mass are preferred, and 100 to 1,000 parts by mass are more preferred, per 100 parts by mass of toner material.

[0275] If the amount of aqueous medium used is less than 50 parts by mass, the dispersion state of the toner material may deteriorate, and it may not be possible to obtain toner matrix particles of the specified particle size. If it exceeds 2,000 parts by mass, production costs may increase.

[0276] When emulsifying or dispersing an oil phase containing 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.

[0277] 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.

[0278] There are no particular restrictions on the surfactant used; it can be appropriately selected depending on the purpose. For example, anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, etc., can be used.

[0279] There are no particular restrictions on the anionic surfactant, and it can be appropriately selected depending on the purpose. Examples include alkylbenzene sulfonates, α-olefin sulfonates, and phosphate esters. Among these, those having a fluoroalkyl group are preferred.

[0280] A catalyst can be used in the extension reaction and / or crosslinking reaction when producing an adhesive substrate.

[0281] There are no particular restrictions on the catalyst, and it can be appropriately selected depending on the purpose. Examples include dibutyl syrup, dioctyl syrup, and the like.

[0282] [Removal of organic solvents] There are no particular restrictions on the method for removing organic solvents from dispersions such as emulsified slurries, 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, or spraying the dispersion into a dry atmosphere to remove the organic solvent in the oil droplets.

[0283] Once the organic solvent is removed, toner matrix particles are formed. These toner matrix particles can be washed, dried, and further classified. Classification may be performed by removing the fine particles in the liquid using a cyclone, decanter, centrifugation, etc., or by performing the classification operation after drying.

[0284] The resulting toner matrix particles may be mixed with particles such as the external additive and the charge control agent. At this time, applying a mechanical impact force can suppress the detachment of particles such as the external additive from the surface of the toner matrix particles.

[0285] There are no particular restrictions on the method of applying 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, or a method of introducing a mixture into a high-speed airflow and accelerating it to cause particles to collide with each other or with a suitable impact plate.

[0286] There are no particular restrictions on the equipment used in the 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), a cryptron system (manufactured by Kawasaki Heavy Industries), an automatic mortar and pestle, etc.

[0287] As described above, the toner according to one embodiment has a plurality of organic resin particles and inorganic external additives on the surface of toner matrix particles containing a binder resin, a colorant, and a wax, with a coating rate of 30% to 70% of organic resin fine particles, and at least one of the inorganic external additives coating the oxide surface of a metal element with a hydroxide of a metal element. In the toner according to one embodiment, by setting the coating rate between adjacent organic resin fine particles on the surface of the toner matrix particles to 30% to 70%, a high level of both low-temperature fixation and heat-resistant storage can be achieved. Furthermore, because a large number of organic resin fine particles are present on the surface of the toner matrix particles, the inorganic external additives are less likely to become embedded in the surface of the toner matrix particles.

[0288] Furthermore, the toner according to one embodiment has excellent electrostatic stability by using a metal element oxide as the substrate for the inorganic external additive, and by coating the surface of the substrate for the inorganic external additive with a metal element hydroxide, the electrostatic rise of the toner can be enhanced and toner scattering can be suppressed. Moreover, in the toner according to one embodiment, intermolecular interactions occur between the surface of the organic resin particles present on the surface of the toner matrix particles and the hydroxyl groups present on the surface of the inorganic external additive, so the release of the inorganic external additive from the toner matrix particles can be suppressed.

[0289] Therefore, the toner according to one embodiment can achieve both low-temperature fixability and heat-resistant storage, suppress contamination of the cleaning member and photoreceptor, and have excellent electrostatic stability.

[0290] In one embodiment of the toner, the outermost surface of the inorganic external additive can be coated with alkylsilane. As a result, the hydrophobicity of the surface of the toner according to this embodiment can be increased, thereby improving the charge level, i.e., improving excellent charge stability and charge rise time.

[0291] In one embodiment of the toner, silica can be used as the oxide of a metal element. This allows the toner according to one embodiment to have improved electrostatic stability.

[0292] In one embodiment, the toner can use at least one selected from the group consisting of aluminum, zinc, and magnesium as the hydroxide of the inorganic external additive. This allows for more readily occurring intermolecular interactions between the surface of the organic resin particles present on the surface of the toner matrix particles and the hydroxyl groups present on the surface of the inorganic external additive, thereby more reliably suppressing the release of the inorganic external additive from the toner matrix particles. Therefore, the toner according to this embodiment can more reliably exhibit the function of the inorganic external additive. This can improve low-temperature fixation and heat resistance during storage.

[0293] <Developer> A developer according to one embodiment includes a toner according to one embodiment and may optionally contain other components such as a carrier, as appropriate. This allows for excellent transferability, electrostatic properties, etc., and enables the stable formation of high-quality images.

[0294] The developer may be a one-component developer or a two-component developer, but when used in high-speed printers and the like to accommodate the recent increase in information processing speed, a two-component developer is preferable from the standpoint of extending its lifespan.

[0295] When toner according to one embodiment is used in a one-component developer, even when toner is replenished, fluctuations in toner particle size are small, toner filming onto the developing roller and toner fusion onto components such as blades that thin the toner layer are minimized, and good and stable developability and high image quality can be obtained even when agitated for a long period of time in the developing device.

[0296] When the developer according to one embodiment is used as a two-component developer, it can be used as a developer after being mixed with a carrier. When the toner according to one embodiment is used as a two-component developer, even if the toner is balanced over a long period of time, there is little change in the toner particle size, and good and stable developability and images can be obtained even if the toner is agitated for a long period of time in the developing device.

[0297] The carrier content in the two-component developer 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.

[0298] The developer according to one embodiment 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.

[0299] [Career] The carrier is not particularly limited and can be appropriately selected according to the purpose, but it is preferable that it has a core material and a resin layer (coating layer) that covers the core material.

[0300] (Core material) There are no particular restrictions on the core material, and it can be appropriately selected according to the purpose. Examples include manganese-strontium materials with a magnetization of 50 emu / g to 90 emu / g, and manganese-magnesium materials with a magnetization 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 of 100 emu / g or more, or magnetite with a magnetization of 75 emu / g to 120 emu / g. Furthermore, it is preferable to use low magnetized materials such as copper-zinc materials with a magnetization of 30 emu / g to 80 emu / g, as this can mitigate the impact of the developer in a slushy state on the photoreceptor and is advantageous for improving image quality. These may be used individually or in combination of two or more types.

[0301] The volume-average particle size of the core material is not particularly limited and 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 size is 10 μm or more, the problem of a large amount of fine powder in the carrier, which can reduce the magnetization per particle and cause carrier scattering can be effectively prevented. On the other hand, if it is 150 μm or less, the specific surface area decreases, which can cause toner scattering, and in full-color printing with many solid areas, this can effectively prevent the problem of poor reproduction of solid areas in particular.

[0302] (Resin layer) There are no particular restrictions on the material of the resin layer, and it can be appropriately selected from known resins according to the purpose. Examples include amino resins, polyvinyl resins, polystyrene resins, polyhalogenated olefins, polyester resins, polycarbonate resins, polyethylene, polyvinyl fluoride, polyvinylidene fluoride, polytrifluoroethylene, polyhexafluoropropylene, copolymers of vinylidene fluoride and acrylic monomers, copolymers of vinylidene fluoride and vinyl fluoride, fluoropolymers such as copolymers of tetrafluoroethylene, vinylidene fluoride and monomers without fluoro groups, and silicone resins. These may be used individually or in combination of two or more.

[0303] There are no particular restrictions on amino-based resins, and they can be appropriately selected depending on the purpose. Examples include urea-formaldehyde resin, melamine resin, benzoguanamine resin, urea resin, polyamide resin, epoxy resin, and the like.

[0304] There are no particular restrictions on the polyvinyl resin used, and it can be appropriately selected depending on the purpose. Examples include acrylic resin, polymethyl methacrylate, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, and polyvinyl butyral.

[0305] There are no particular restrictions on the polystyrene-based resin, and it can be appropriately selected depending on the purpose. Examples include polystyrene and styrene-acrylic copolymers.

[0306] There are no particular restrictions on the polyhalogenated olefin, and it can be appropriately selected depending on the purpose. Examples include polyvinyl chloride, etc.

[0307] There are no particular restrictions on the polyester resin used; it can be appropriately selected depending on the purpose. Examples include polyethylene terephthalate and polybutylene terephthalate.

[0308] The resin layer may contain conductive powder or the like, if necessary. There are no particular restrictions on the conductive powder, and it can be appropriately selected depending on the purpose. Examples include metal powder, carbon black, titanium dioxide, tin oxide, zinc oxide, etc. The average particle size of the conductive powder is preferably 1 μm or less. When the average particle size is 1 μm or less, the electrical resistance can be controlled.

[0309] The resin layer can be formed by dissolving a silicone resin or the like in a solvent to prepare a coating solution, then applying the coating solution to the surface of the core material using a known coating method, drying it, and then baking it.

[0310] There are no particular restrictions on the application method, and it can be appropriately selected according to the purpose. For example, immersion coating, spray coating, brush coating, etc., can be used.

[0311] There are no particular restrictions on the solvent, and it can be appropriately selected depending on the purpose. Examples include toluene, xylene, methyl ethyl ketone, methyl isobutyl ketone, butyl cellosolve acetate, and the like.

[0312] The baking process may be carried out using an external heating method or an internal heating method, such as using a fixed electric furnace, a fluidized bed electric furnace, a rotary electric furnace, a burner furnace, or a microwave.

[0313] There are no particular restrictions on the resin layer content in the carrier, and it can be appropriately selected depending on the purpose, but 0.01% to 5.0% by mass is preferred. If the resin layer content is 0.01% by mass or more, a uniform resin layer can be formed on the surface of the core material, and if it is 5.0% by mass or less, the thickness of the resin layer is suppressed, which suppresses fusion between carriers and maintains the uniformity of the carriers.

[0314] <Developer container> A developer container according to one embodiment contains the developer according to one embodiment. The developer container is not particularly limited and can be appropriately selected from known containers, but examples include those having a container body and a cap.

[0315] Furthermore, the size, shape, structure, and material of the container body are not particularly limited, but the shape is preferably cylindrical, with spiral-shaped irregularities formed on the inner surface, allowing the developer contents to move towards the discharge port by rotation, and it is particularly preferable that some or all of the spiral-shaped irregularities have a bellows function. In addition, the material is not particularly limited, but it is preferable that it has good dimensional accuracy, and examples of resin materials include polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, polyacrylic acid, polycarbonate resin, ABS resin, and polyacetal resin.

[0316] The developer container is easy to store and transport, and offers excellent handling, so it can be detachably attached to the image forming apparatus, process cartridge, etc., described later, and used for replenishing the developer.

[0317] <Toner storage unit> A toner storage unit according to one embodiment can store toner according to one embodiment. A toner storage unit according to one embodiment refers to a unit having the function of storing toner, in which toner is stored. Here, examples of the form of the toner storage unit include a toner storage container, a developer, and a process cartridge.

[0318] A toner container refers to a container that holds toner.

[0319] A developing unit refers to a device that has the means to store toner and develop it.

[0320] A process cartridge is defined as a device that integrates at least an electrostatic latent image carrier (also called an image carrier) and a developing means, contains toner, and is detachable from an image forming apparatus. The process cartridge may further include at least one selected from a charging unit, an exposure unit, a cleaning unit, etc.

[0321] A toner storage unit according to one embodiment houses the toner according to one embodiment, and the toner according to one embodiment has the characteristics of excellent offset resistance, charge stability, stress resistance, and background stain resistance, enabling it to provide high-definition, high-quality images over a long period of time. By mounting the toner storage unit according to one embodiment in an image forming apparatus and forming an image utilizing the characteristics of the toner according to one embodiment, it is possible to form images that have long-term image stability and are of high quality and high definition.

[0322] <Image forming apparatus> An image forming apparatus according to one embodiment includes an electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, and a developing unit that develops the electrostatic latent image formed on the electrostatic latent image carrier using toner to form a toner image, and may further have other configurations as needed.

[0323] In one embodiment, the image forming apparatus more preferably includes, in addition to the electrostatic latent image carrier, electrostatic latent image forming unit and developing unit, a transfer unit for transferring a toner image to a recording medium and a fixing unit for fixing the transferred image onto the surface of the recording medium.

[0324] In the developing section, a toner according to one embodiment is used. Preferably, a developer containing the toner according to one embodiment, and optionally containing other components such as a carrier, may be used to form a toner image.

[0325] (Electrostatic latent image carrier) The material, shape, structure, size, etc., of the electrostatic latent image carrier (sometimes referred to as "electrophotographic photoreceptor" or "photoreceptor") are not particularly limited and can be appropriately selected from known materials. Examples of materials for the electrostatic latent image carrier include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors (OPC) such as polysilane and phthalopolymethine. Among these, amorphous silicon is preferred in terms of long lifespan, and organic photoreceptors (OPC) are preferred in that they can produce higher-resolution images.

[0326] As amorphous silicon photoreceptors, for example, a photoreceptor having a photoconductive layer made of a-Si can be used by heating the support to 50°C to 400°C and depositing it on the support using methods such as vacuum deposition, sputtering, ion plating, thermal CVD (chemical vapor deposition), photo-CVD, or plasma CVD. Among these, plasma CVD, that is, a method in which a source gas is decomposed by DC, high-frequency, or microwave glow discharge to form an a-Si deposited film on the support, is preferred.

[0327] There are no particular restrictions on the shape of the electrostatic latent image carrier, and it can be appropriately selected depending on the purpose, but a cylindrical shape is preferred. There are no particular restrictions on the outer diameter of the cylindrical electrostatic latent image carrier, and it can be appropriately selected depending on the purpose, but 3 mm to 100 mm is preferred, 5 mm to 50 mm is more preferred, and 10 mm to 30 mm is particularly preferred.

[0328] The linear velocity of the electrostatic latent image carrier is preferably 300 mm / s or higher.

[0329] (Electrostatic latent image formation section) The electrostatic latent image forming unit is not particularly limited as long as it is a means for forming an electrostatic latent image on an electrostatic latent image carrier, and can be appropriately selected according to the purpose. The electrostatic latent image forming unit includes, for example, a charging member (charger) that uniformly charges the surface of the electrostatic latent image carrier, and an exposure member (exposure unit) that exposes the surface of the electrostatic latent image carrier in an image-like manner.

[0330] The charger is not particularly limited and can be appropriately selected according to the purpose, but examples include contact chargers equipped with conductive or semiconductive rolls, brushes, films, rubber blades, etc., and non-contact chargers that utilize corona discharge such as Corotron and Scorotron.

[0331] The shape of the charger can be anything 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.

[0332] Preferably, the charger is positioned in contact with or without contact with the electrostatic latent image carrier, and charges the surface of the electrostatic latent image carrier by superimposing DC and AC voltages. Alternatively, it is preferable that the charger is a charging roller positioned in close proximity to the electrostatic latent image carrier via a gap tape, and charges the surface of the electrostatic latent image carrier by superimposing DC and AC voltages on the charging roller.

[0333] While the charger is not limited to a contact-type charger, it is preferable to use a contact-type charging element because it allows for the creation of an image forming apparatus with reduced ozone generation from the charger.

[0334] The exposure device is not particularly limited as long as it can expose the surface of an electrostatic latent image carrier charged by a charger in the manner of the image to be formed, and can be appropriately selected according to the purpose. Examples of exposure devices include copying optical systems, rod lens array systems, laser optical systems, and liquid crystal shutter optical systems.

[0335] There are no particular restrictions on the light source used in an exposure unit, 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 types of light-emitting materials.

[0336] 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.

[0337] Furthermore, the exposure unit may employ a back-facing method that exposes the electrostatic latent image carrier in an image-like manner from the back side.

[0338] (Developing Department) The developing unit is not particularly limited as long as it can develop the electrostatic latent image formed on the electrostatic latent image carrier to form a visible image, and can be appropriately selected according to the purpose. The developing unit can preferably be one that includes a developer that contains toner and can apply toner to the electrostatic latent image by contact or non-contact, and a developer with a toner container is preferred.

[0339] The developing unit may be a single-color developing unit or a multi-color developing unit. Suitable developing devices include, for example, a developing apparatus that has an agitator that frictionally agitates and charges the toner, a magnetic field generating unit fixed inside, and a rotatable developer carrier (e.g., a magnetic roller) on its surface that carries a developer containing toner.

[0340] (Transfer section) The transfer unit preferably has a primary transfer unit that transfers a visible image onto an intermediate transfer unit to form a composite transfer image, and a secondary transfer unit that transfers the composite transfer image onto a recording medium. The intermediate transfer unit is not particularly limited and can be appropriately selected from known transfer units depending on the purpose, for example, a transfer belt is a suitable example.

[0341] The transfer section (primary transfer means and secondary transfer section) preferably includes at least a transfer device that exfoliates and charges the visible image formed on the electrostatic latent image carrier (photoreceptor) toward the recording medium. There may be one transfer section or two or more.

[0342] Examples of transfer devices include corona discharge transfer devices, transfer belts, transfer rollers, pressure transfer rollers, and adhesive transfer devices.

[0343] While plain paper is typically used as the recording medium, there are no particular restrictions as long as it is capable of transferring the unfixed image after development. Any known recording medium (recording paper) can be appropriately selected according to the purpose, and PET bases for OHPs can also be used.

[0344] (Fixing part) The fixing section is not particularly limited and can be appropriately selected according to the purpose, but a known heating and pressing section is preferred. Examples of heating and pressing sections 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.

[0345] The fixing section preferably comprises a heating element equipped with a heating element, a film in contact with the heating element, and a pressurizing member that presses against the heating element via the film, and is capable of heating and fixing a recording medium on which an unfixed image has been formed between the film and the pressurizing member.

[0346] The heating temperature in the heating and pressurizing section is usually preferably between 80°C and 200°C.

[0347] There are no particular restrictions on the surface pressure in the heating and pressurizing section, 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.

[0348] In this embodiment, depending on the purpose, a known optical fuser may be used together with or in place of the fuser unit.

[0349] (others) The image forming apparatus relating to the primary form may also include, for example, a static elimination unit, a recycling unit, a control unit, and the like.

[0350] ((Static elimination section)) The static elimination unit is not particularly limited and only needs to be able to apply a static elimination bias to the electrostatic latent image carrier. It can be appropriately selected from known static eliminators, for example, a static elimination lamp is a suitable example.

[0351] ((Cleaning Department)) The cleaning unit only needs to be able to remove toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. Examples of cleaning units include magnetic brush cleaners, electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, and web cleaners.

[0352] The primary image forming apparatus can improve cleaning performance by having a cleaning section. Specifically, by controlling the adhesion force between toners, the fluidity of the toner is maintained, thereby improving cleaning performance. Furthermore, by controlling the characteristics of the toner after degradation, excellent cleaning quality can be maintained even under harsh conditions such as extended lifespan and high temperature and humidity. In addition, since the external additive can be sufficiently released from the toner on the photoreceptor, a deposit layer (dam layer) of the external additive can be formed in the cleaning blade nip section, thereby achieving high cleaning performance.

[0353] ((Recycling Department)) The recycling department is not particularly restricted and can use known means of transport, etc.

[0354] ((Control Unit)) The control unit can control the movement of each of the above-mentioned parts. The control unit is not particularly limited as long as it can control the movement of each of the above-mentioned parts, and can be appropriately selected according to the purpose. Examples include control devices such as sequencers and computers.

[0355] The image forming apparatus according to one embodiment can perform image formation using the toner according to one embodiment, and therefore has excellent transferability, electrostatic properties, etc., and can stably provide high-quality images.

[0356] <Image forming method> An image forming method according to one embodiment includes an electrostatic latent image formation step of forming an electrostatic latent image on an electrostatic latent image carrier, and a development step of developing the electrostatic latent image using toner to form a toner image, and may further include other steps as necessary. The image forming method can be suitably carried out by an image forming apparatus, the electrostatic latent image formation step can be suitably carried out by an electrostatic latent image formation unit, the development step can be suitably carried out by a development unit, and the other steps can be suitably carried out by other units.

[0357] Furthermore, the image forming method according to one embodiment more preferably includes, in addition to the electrostatic latent image formation step and the development step described above, a transfer step for transferring a toner image to a recording medium and a fixing step for fixing the transferred image on the surface of the recording medium.

[0358] In the development process, a toner according to one embodiment is used. Preferably, a developer containing the toner according to one embodiment, and optionally containing other components such as a carrier, may be used to form a toner image.

[0359] The electrostatic latent image formation process is a process of forming an electrostatic latent image on an electrostatic latent image carrier, and includes a charging step of charging the surface of the electrostatic latent image carrier and an exposure step of exposing the charged surface of the electrostatic latent image carrier to form an electrostatic latent image. Charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using a charger. Exposure can be performed, for example, by exposing the surface of the electrostatic latent image carrier in an image-like manner using an exposure unit. Formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then exposing it in an image-like manner, and can be performed by an electrostatic latent image formation unit.

[0360] The development process is a process of sequentially developing an electrostatic latent image with multiple toners to form a visible image. The formation of the visible image can be done, for example, by developing the electrostatic latent image using toner, and this can be done using a developing unit.

[0361] Inside the developing unit, for example, toner and carrier are mixed and stirred, and the friction during this process causes the toner to become charged. This charge is then held in a pile-like state on the surface of the rotating magnetic roller, forming a magnetic brush. Since the magnetic roller is positioned near the electrostatic latent image carrier (photoreceptor), some of the toner that makes up the magnetic brush formed on the surface of the magnetic roller moves to the surface of the electrostatic latent image carrier (photoreceptor) due to electrical attraction. As a result, the electrostatic latent image is developed by the toner, and a visible image is formed on the surface of the electrostatic latent image carrier (photoreceptor) by the toner.

[0362] The transfer process is a process of transferring a visible image to a recording medium. The transfer process is preferably carried out using an intermediate transfer medium, in which the visible image is first transferred onto the intermediate transfer medium, and then the visible image is secondarily transferred onto the recording medium.

[0363] The transfer process more preferably includes a first transfer step in which a visible image is transferred onto an intermediate transfer medium using two or more toners, preferably full-color toners, to form a composite transfer image, and a second transfer step in which the composite transfer image is transferred onto a recording medium. If the image to be secondarily transferred onto the recording medium is a color image consisting of multiple toners, an intermediate transfer medium may be used to sequentially superimpose each color of toner onto the intermediate transfer medium to form an image on the intermediate transfer medium, and the image on the intermediate transfer medium may be secondarily transferred onto the recording medium all at once using the intermediate transfer medium.

[0364] Transfer can be performed, for example, by charging an electrostatic latent image carrier (photoreceptor) with a transfer charger using a visible image, and this can be done by the transfer unit.

[0365] The fixing process is the process of fixing the visible image transferred to the recording medium using a fixing device. This process may be performed for each color developer after the image is transferred to the recording medium, or it may be performed simultaneously for each color developer in a stacked state.

[0366] The image formation method for the primary form may further include other steps as appropriate, such as static elimination steps, cleaning steps, and recycling steps.

[0367] The static elimination process involves applying a static elimination bias to the electrostatic latent image carrier to remove static electricity, and this process can be more effectively performed by the static elimination unit.

[0368] The cleaning process is a process of removing toner remaining on the electrostatic latent image carrier, and can be performed more effectively by the cleaning unit.

[0369] The recycling process involves recycling the toner removed during the cleaning process into the developing unit, and can be performed more effectively in the recycling unit.

[0370] The image forming method according to one embodiment can perform image formation using the toner according to one embodiment, and therefore has excellent transferability, electrostatic properties, etc., and can stably provide high-quality images.

[0371] [An embodiment of an image forming apparatus] Next, one aspect of an image forming apparatus according to one embodiment will be described with reference to Figure 1. Figure 1 is a schematic configuration diagram showing an example of an image forming apparatus according to one embodiment. As shown in Figure 1, the image forming apparatus 100A comprises a photosensitive drum 10 which is an electrostatic latent image carrier, a charging roller 20 which is a charging unit, an exposure unit 30 which is an exposure unit, a developing unit 40 which is a developing unit, an intermediate transfer body (intermediate transfer belt) 50, a cleaning unit 60 which is a cleaning unit, a transfer roller 70 which is a transfer unit, a static elimination lamp 80 which is a static elimination unit, and an intermediate transfer body cleaning unit 90.

[0372] The intermediate transfer body 50 is an endless belt stretched by three rollers 51 located on its inside, and is designed to be movable in the direction of the arrow by the three rollers 51. Some of the three rollers 51 also function as transfer bias rollers capable of applying a predetermined transfer bias (primary transfer bias) to the intermediate transfer body 50. An intermediate transfer body cleaning device 90 is located near the intermediate transfer body 50. Furthermore, a transfer roller 70 is located near the intermediate transfer body 50, facing the intermediate transfer body 50, and can apply a transfer bias (secondary transfer bias) for transferring the developed image (toner image) to the transfer paper P, which is the recording medium (secondary transfer). Around the intermediate transfer body 50, a corona charger 52 for imparting charge to the toner image on the intermediate transfer body 50 is located between the contact area between the photoreceptor drum 10 and the intermediate transfer body 50, and between the intermediate transfer body 50 and the transfer paper P, with respect to the rotation direction of the intermediate transfer body 50.

[0373] The developing apparatus 40 consists of a developing belt 41, which is a developer carrier, and a developing unit 42 that is arranged around the developing belt 41.

[0374] The developing belt 41 is an endless belt stretched by multiple belt rollers and can move in the direction of the arrow in the figure. Furthermore, a portion of the developing belt 41 is in contact with the photoreceptor drum 10.

[0375] The developing unit 42 consists of a black (Bk) developing unit 42K, a yellow (Y) developing unit 42Y, a magenta (M) developing unit 42M, and a cyan (C) developing unit 42C.

[0376] The black developing unit 42K comprises a developer container 421K, a developer supply roller 422K, and a developing roller (developer carrier) 423K. The yellow developing unit 42Y comprises a developer container 421Y, a developer supply roller 422Y, and a developing roller 423Y. The magenta developing unit 42M comprises a developer container 421M, a developer supply roller 422M, and a developing roller 423M. The cyan developing unit 42C comprises a developer container 421C, a developer supply roller 422C, and a developing roller 423C.

[0377] Next, a method for forming an image using the image forming apparatus 100A will be described. First, the surface of the photoreceptor drum 10 is uniformly charged using the charging roller 20, and then the photoreceptor drum 10 is exposed to exposure light L using the exposure apparatus 30 to form an electrostatic latent image. Next, the electrostatic latent image formed on the photoreceptor drum 10 is developed with toner supplied from the developing apparatus 40 to form a toner image. Furthermore, the toner image formed on the photoreceptor drum 10 is transferred (primary transfer) onto the intermediate transfer body 50 by a transfer bias applied from the roller 51, and then transferred (secondary transfer) onto the transfer paper P fed by a paper feeding unit (not shown) by a transfer bias applied from the transfer roller 70. Meanwhile, the photoreceptor drum 10 on which the toner image has been transferred to the intermediate transfer body 50 is de-static by the static elimination lamp 80 after the toner remaining on the surface is removed by the cleaning apparatus 60. The remaining toner on the intermediate transfer body 50 after image transfer is removed by the intermediate transfer body cleaning apparatus 90.

[0378] After the transfer process is complete, the transfer paper P is transported to the fixing unit, where the transferred toner image is fixed to the transfer paper P.

[0379] Figure 2 is a schematic diagram showing another example of an image forming apparatus according to one embodiment. As shown in Figure 2, the image forming apparatus 100B has the same configuration as the image forming apparatus 100A shown in Figure 1, except that the developing belt 41 is not provided and the developing units 42 (black developing unit 42K, yellow developing unit 42Y, magenta developing unit 42M, and cyan developing unit 42C) are arranged directly opposite each other around the photoreceptor drum 10.

[0380] Figure 3 is a schematic diagram showing another example of an image forming apparatus according to one embodiment. As shown in Figure 3, the image forming apparatus 100C is a tandem-type color image forming apparatus and includes a copy device body 110, a paper feed table 120, a scanner 130, an automatic document feeder (ADF) 140, a secondary transfer device 150, a fixing unit which is a fixing device 160, and a sheet reversing device 170.

[0381] An endless belt-shaped intermediate transfer body 50 is provided in the center of the main body 110 of the copying device. The intermediate transfer body 50 is an endless belt stretched over three rollers 53A, 53B, and 53C, and can move in the direction of the arrow in Figure 3. Near roller 53B, an intermediate transfer body cleaning device 90 is arranged to remove toner remaining on the intermediate transfer body 50 after the toner image has been transferred to the recording paper. Opposite the intermediate transfer body 50 stretched by rollers 53A and 53B, and along the transport direction, are tandem-type developing units 42 (yellow (Y) developing unit 42Y, cyan (C) developing unit 42C, magenta (M) developing unit 42M, and black (Bk) developing unit 42K) which are arranged side by side.

[0382] Furthermore, an exposure device 30 is located near the developing unit 42. In addition, a secondary transfer device 150 is located on the side of the intermediate transfer body 50 opposite to the side where the developing unit 42 is located. The secondary transfer device 150 includes a secondary transfer belt 151. The secondary transfer belt 151 is an endless belt stretched over a pair of rollers 152, and the recording paper and the intermediate transfer body 50 being transported on the secondary transfer belt 151 can come into contact between the roller 53C and the roller 152.

[0383] Furthermore, a fixing device 160 is positioned near the secondary transfer belt 151. The fixing device 160 comprises a fixing belt 161, which is an endless belt stretched over a pair of rollers, and a pressure roller 162 that is positioned under pressure from the fixing belt 161.

[0384] Furthermore, a sheet reversing device 170 is positioned near the secondary transfer belt 151 and the fixing device 160 to reverse the recording paper when forming an image on both sides of the recording paper.

[0385] Next, a method for forming a full-color image using the image forming apparatus 100C will be described. First, a color document is placed on the document glass 141 of the automatic document feeder (ADF) 140, or the automatic document feeder 140 is opened and the color document is placed on the contact glass 131 of the scanner 130, and the automatic document feeder 140 is closed.

[0386] When the start switch (not shown) is pressed, if a color document is placed in the automatic document transporter 140, the color document is transported and moved onto the contact glass 131, after which the scanner 130 is driven and the first and second traveling bodies 132 and 133, which are equipped with light sources, move. On the other hand, if a document is placed on the contact glass 131, the scanner 130 is driven immediately and the first and second traveling bodies 132 and 133, which are equipped with light sources, move. At this time, the light emitted from the first traveling body 132 is reflected from the document surface by the mirror of the second traveling body 133, and then received by the reading sensor 136 through the imaging lens 135, thereby reading the color document (color image) and obtaining image information in black, yellow, magenta, and cyan.

[0387] Image information for each color is transmitted to the respective color developing units (yellow developing unit 42Y, cyan developing unit 42C, magenta developing unit 42M, and black developing unit 42K), and toner images for each color are formed.

[0388] Figure 4 is a partially enlarged view of the image forming apparatus shown in Figure 3. As shown in Figure 4, each developing unit (yellow developing unit 42Y, cyan developing unit 42C, magenta developing unit 42M, and black developing unit 42K) comprises a photoreceptor drum 10 (static photoreceptor drum 10K for black, photoreceptor drum 10Y for yellow, photoreceptor drum 10M for magenta, and photoreceptor drum 10C for cyan), a charging roller 20 which is a charging unit that uniformly charges the photoreceptor drum 10, an exposure device 30 which exposes the photoreceptor drum 10 with exposure light L based on image information for each color and forms an electrostatic latent image of each color on the photoreceptor drum 10, a developing device 40 which is a developing unit that develops the electrostatic latent image with a developer of each color to form a toner image of each color, a transfer charger 62 for transferring the toner image onto an intermediate transfer body 50, a cleaning device 60, and an anti-static lamp 80.

[0389] The toner images of each color formed by the respective color developing units (yellow developing unit 42Y, cyan developing unit 42C, magenta developing unit 42M, and black developing unit 42K) are sequentially transferred (primary transfer) onto an intermediate transfer body 50 that is stretched and moved on rollers 53A, 53B, and 53C. Then, the toner images of each color are superimposed on the intermediate transfer body 50 to form a composite color image (color transfer image).

[0390] Meanwhile, in the paper feed table 120, one of the paper feed rollers 121 is selectively rotated to feed recording paper from one of the paper cassettes 123 arranged in multiple stages in the paper bank 122. The recording paper is separated one sheet at a time by the separation roller 124 and sent to the paper feed path 125, transported by the transport roller 126 and guided to the paper feed path 111 in the main body of the copier 110, where it is stopped by the registration roller 112. Alternatively, the manual feed roller 113 is rotated to feed recording paper from the manual feed tray 114, separates it one sheet at a time by the manual feed roller 113 and guides it to the manual feed path 115, where it is stopped by the registration roller 112.

[0391] Although the registration roller 112 is generally used with grounding, it may also be used with a bias applied to remove paper dust from the recording paper.

[0392] Next, the register roller 112 is rotated in time with the composite color image (color transfer image) formed on the intermediate transfer body 50, and recording paper is fed between the intermediate transfer body 50 and the secondary transfer belt 151 to transfer the composite color image (color transfer image) onto the recording paper (secondary transfer). Any toner remaining on the intermediate transfer body 50 onto which the composite color image (color transfer image) has been transferred is removed by the intermediate transfer body cleaning device 90.

[0393] After the composite color image (color transfer image) is transferred to the recording paper, it is transported by the secondary transfer belt 151, and then the composite toner image is fixed onto the recording paper by the fixing device 160.

[0394] Subsequently, the transport path of the recording paper is switched by the switching claw 116, and the recording paper is discharged onto the output tray 118 by the discharge roller 117. Alternatively, the transport path of the recording paper is switched by the switching claw 116, the recording paper is inverted by the sheet inversion device 170, and guided again to the secondary transfer belt 151, where an image is formed on the reverse side in the same manner, and then discharged onto the output tray 118 by the discharge roller 117.

[0395] <Processing Cartridge> A process cartridge according to one embodiment is molded to be detachable from various image forming apparatuses and includes an electrostatic latent image carrier that carries an electrostatic latent image, and a developing unit that develops the electrostatic latent image carried on the electrostatic latent image carrier with the developer according to the above embodiment to form a toner image, and may have other configurations as needed.

[0396] The electrostatic latent image carrier is the same as the electrostatic latent image carrier in the image forming apparatus described above, so details are omitted.

[0397] The developing unit includes a developer container for containing a developer according to one embodiment, and a developer carrier for carrying and transporting the developer contained in the developer container. The developing unit may further include regulating members or the like to regulate the thickness of the carried developer.

[0398] Figure 6 shows an example of a process cartridge according to one embodiment. As shown in Figure 6, the image forming apparatus process cartridge 200 includes a photoreceptor drum 10, a corona charger 22 which is a charging unit, a developing unit 40, a cleaning unit 60, and a transfer roller 70. In the figure, P represents the transfer paper and L represents the exposure light. [Examples]

[0399] The embodiments will be described in more detail below with reference to examples and comparative examples, but the embodiments are not limited to these examples and comparative examples.

[0400] -Toner Manufacturing- (Examples of crystalline polyester resin production) <Synthesis of crystalline polyester resin 1> Sebacic acid and 1,6-hexanediol were charged into a reaction vessel equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple. At this time, the molar ratio of hydroxyl groups to carboxyl groups was set to 0.9, and 500 ppm of titanium tetraisopropoxide was added to the total monomer. Next, the reaction was carried out at 180°C for 10 hours, then the temperature was raised to 200°C and the reaction was carried out for 3 hours. Furthermore, the reaction was carried out under reduced pressure of 8.3 kPa for 2 hours to obtain crystalline polyester resin 1. Crystalline polyester resin 1 had a melting point of 67°C and a weight-average molecular weight of 25,000.

[0401] (Examples of amorphous polyester resin manufacturing) <Synthesis of amorphous polyester resin 1> In a 5L four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple, 1427.5g of bisphenol A propylene oxide side 2 molar adduct, 20.2g of trimethylolpropane, 512.7g of terephthalic acid, and 119.9g of adipic acid were placed and reacted at 230°C under atmospheric pressure for 10 hours, followed by a further reaction under reduced pressure of 10mmHg to 15mmHg for 5 hours. Then, 41.0g of trimellitic anhydride was added to the reaction vessel and reacted at 180°C under atmospheric pressure for 3 hours to obtain amorphous polyester resin 1. Amorphous polyester resin 1 had a weight-average molecular weight (Mw) of 10,000, a number-average molecular weight of 2,900, a Tg of 57.5℃, and an acid value of 20 mgKOH / g.

[0402] (Example of manufacturing a crystalline polyester resin dispersion) <Preparation of crystalline polyester resin dispersion 1> 100 parts by mass of crystalline polyester resin 1 and 200 parts by mass of ethyl acetate were placed in a 2L metal container, heated and dissolved at 75°C, and then rapidly cooled in an ice bath at a rate of 27°C / min. 500 mL of glass beads (3 mmφ) were added to this, and the mixture was ground for 10 hours using a batch-type sand mill (manufactured by Kanpe Hapio Co., Ltd.) to obtain crystalline polyester resin dispersion 1.

[0403] (Preparation of organic particulate dispersion) <Manufacturing 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, 3710 parts by mass of water and 200 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% ammonium persulfate aqueous solution were added, and then a mixture consisting of 450 parts by mass of styrene, 250 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 a fine particle dispersion (W0-1) containing a resin (a1-1) which is a polymer copolymerized with the monomer and polyoxyethylene-1-(allyloxymethyl)alkyl ether sulfate ammonium. The volume-average particle size of the microparticles in the microparticle dispersion (W0-1) was measured using dynamic light scattering (light scattering electrophoresis apparatus: ELS-8000, manufactured by Otsuka Electronics Co., Ltd.) and was found to be 15 nm. A portion of the fine particle dispersion (W0-1) was dried to isolate the resin (a1-1). The glass transition temperature (TgA) of the resin was 75°C, and its acid value was 195 mgKOH / g.

[0404] <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% ascorbic acid aqueous solution 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 measured in the same manner as described above and was found to be 17.3 nm. The resin (a2-1) was isolated by neutralizing an aqueous dispersion (W-1) of resin fine particles (A-1) with a 10% aqueous ammonia solution to pH 9.0, and then drying the precipitate obtained by centrifugation. The glass transition temperature (Tg) of the resin was 61°C.

[0405] 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% ruthenium tetroxide aqueous solution in vapor phase for 5 minutes, and finally observed using a transmission electron microscope (Hitachi Technologies, Ltd., H-7100).

[0406] <Manufacturing of organic particulate emulsion (particulate dispersion)> In a reaction vessel equipped with a stirring rod and thermometer, 683 parts by mass of water, 11 parts by mass of sodium salt of ethylene oxide adduct sulfate methacrylate (product name: Eleminol RS-30, manufactured by Sanyo Chemical Industries, Ltd.), 138 parts by mass of styrene, 138 parts by mass of methacrylic acid, and 1 part by mass of ammonium persulfate were charged and stirred at 400 rpm for 15 minutes, yielding a white emulsion. This was heated to a system temperature of 75°C and reacted for 5 hours. Furthermore, 30 parts by mass of a 1% aqueous solution of ammonium persulfate was added and aged at 75°C for 5 hours to obtain an aqueous dispersion of vinyl resin (polymer of styrene-methacrylic acid-sodium salt of ethylene oxide adduct sulfate methacrylate) [fine particle dispersion 2]. When [fine particle dispersion 2] was measured using a laser diffraction / scattering particle size distribution analyzer (LA-920, HORIBA Corporation), the volume-average particle size was found to be 0.14 μm. A portion of [fine particle dispersion 2] was dried to isolate the resin component.

[0407] (Manufacturing Example 1) [Production of aqueous dispersion (W0-1) of resin microparticles (A)] In a reaction vessel equipped with a stirrer, heating / cooling device, and thermometer, 3710 parts by mass of water and 200 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% ammonium persulfate aqueous solution were added, and then a mixture consisting of 450 parts by mass of styrene, 250 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 a fine particle dispersion (W0-1) containing a resin (a1-1) which is a polymer copolymerized with the monomer and polyoxyethylene-1-(allyloxymethyl)alkyl ether sulfate ammonium. The volume-average particle size of the microparticles in the microparticle dispersion (W0-1) was measured using dynamic light scattering (light scattering electrophoresis apparatus: ELS-8000, manufactured by Otsuka Electronics Co., Ltd.) and was found to be 15 nm. A portion of the fine particle dispersion (W0-1) was dried to isolate the resin (a1-1). The glass transition temperature (TgA) of the resin was 75°C, and its acid value was 195 mgKOH / g.

[0408] (Manufacturing example 2) [Production of aqueous dispersion (W0-2) 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 rpm until homogenized. The homogenized mixture was heated to a system temperature of 75°C, after which 90 parts by mass of a 10% ammonium persulfate aqueous solution was added, followed by the dropwise addition of 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 over 4 hours. After dropwise addition, the mixture was aged at 75°C for 4 hours to obtain a fine particle dispersion (W0-2) containing a resin (a3-1) which is a polymer copolymer of the monomer and polyoxyethylene-1-(allyloxymethyl)alkyl ether sulfate ammonium. The volume-average particle size of the fine particles in the fine particle dispersion (W0-2) was measured in the same manner as in Production Example 1 and was found to be 45 nm. A portion of the fine particle dispersion (W0-2) was dried to isolate the resin (a2-1). The glass transition temperature (TgA) of the resin was 65°C, and its acid value was 195 mgKOH / g.

[0409] (Manufacturing Example 3) <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% ascorbic acid aqueous solution 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 measured in the same manner as in Manufacturing Example 1 and was found to be 17.3 nm. The resin (a2-1) was isolated by neutralizing an aqueous dispersion (W-1) of resin fine particles (A-1) with a 10% aqueous ammonia solution to pH 9.0, and then drying the precipitate obtained by centrifugation. The glass transition temperature (Tg) of the resin was 61°C.

[0410] 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% ruthenium tetroxide aqueous solution in vapor phase for 5 minutes, and finally observed using a transmission electron microscope (Hitachi Technologies, Ltd., H-7100).

[0411] (Manufacturing example 4) <Manufacturing of aqueous dispersion (W-2) of resin microparticles (A-2)> Next, in a reaction vessel equipped with a stirrer, a heating and cooling device, and a thermometer, 667 parts by mass of an aqueous dispersion of resin fine particles (A) (W0-2) and 248 parts by mass of water were charged. Then, 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. After that, 43.3 parts by mass of styrene, 23.3 parts by mass of butyl acrylate, and 18.0 parts by mass of a 1% ascorbic acid aqueous solution were added dropwise over 2 hours. After dropwise addition, the mixture was aged at 70°C for 4 hours to obtain a fine particle dispersion (W-2) of resin fine particles (A-2) containing resin (a2-2), which is a polymer copolymerized from the monomer using the resin fine particles in (W0-2) as seeds, and resin (a1-2) as constituent components within the same particle. The volume-average particle size of the resin microparticles (A-2) was measured in the same manner as in Manufacturing Example 1 and was found to be 51.5 nm. The resin (a2-3) was isolated by neutralizing an aqueous dispersion (W-2) of resin fine particles (A-2) with a 10% aqueous ammonia solution to pH 9.0, and then drying the precipitate obtained by centrifugation. The glass transition temperature (Tg) of the resin was 55°C. It was confirmed, using the same method as in Production Example 4, that the aqueous dispersion (W-2) of resin microparticles (A-2) contains resin microparticles (A-2) that include resin (a1-2) and resin (a2-2) as constituent components within the same particle.

[0412] (Manufacturing example 5) <Synthesis of amorphous polyester resin (b-1)> 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 (b-1) was obtained. The glass transition temperature (Tg) of this 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.

[0413] (Manufacturing example 6) <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 (Solspers 28000, manufactured by Abyssia), 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. After that, 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.

[0414] (Manufacturing example 7) <Manufacturing of modified wax (d)> 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 modified wax (d). The SP value of the graft chain of modified wax (d) is 10.35 (cal / cm²). 3 ) 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.

[0415] (Manufacturing example 8) <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 (d), 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.

[0416] (Manufacturing example 9) <Manufacturing of reactive prepolymer (α2b-1)> In a reaction vessel equipped with a condenser, a stirrer, and nitrogen inlet tube, 3-methyl-1,5-pentanediol, isophthalic acid, adipic acid, and trimellitic anhydride were added together with titanium tetraisopropoxide (1,000 ppm relative to the resin component) such that the molar ratio of hydroxyl groups to carboxyl groups (OH / COOH) was 1.5, the diol component consisted of 100 mol% 3-methyl-1,5-pentanediol, the dicarboxylic acid component consisted of 40 mol% isophthalic acid and 60 mol% adipic acid, and the amount of trimellitic anhydride in the total monomer was 1 mol%. The temperature was then raised to 200°C over approximately 4 hours, and then to 230°C over 2 hours, and the reaction continued until all the effluent was gone. Subsequently, the reaction was carried out under reduced pressure of 10 mmHg to 15 mmHg for 5 hours to obtain [intermediate polyester C-1]. Next, [intermediate polyester C-1] and isophorone diisocyanate (IPDI) were added to a reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet tube in a molar ratio (isocyanate groups of IPDI / hydroxyl groups of intermediate polyester) of 2.0. After diluting with ethyl acetate to a 50% ethyl acetate solution, the mixture was reacted at 100°C for 5 hours to obtain [reactive prepolymer (α2b-1)].

[0417] (Manufacturing example 10) <Preparation of inorganic external additives> <<Preparation of Inorganic External Additive 1>> First, silica particles manufactured by the liquid-phase method (Tosoh Silica Nip Seal SP-200B ET, specific surface area 200m²) 2 100g of ( / g) was dispersed in 2L of water and heated to 85°C. Next, an aqueous zinc chloride solution was added in an amount equivalent to 10% by mass of ZnO relative to the silica particles, and the pH was adjusted to 8.0 with an aqueous sodium hydroxide solution. After holding with stirring for 30 minutes, the mixture was filtered and the residue on the filter media was washed with water to obtain a washed cake. Next, this washed cake was dried at 120°C and then pulverized using a media-type fine grinder. Finally, 40g of the obtained powder was placed in a small mixer, 10g of isobutyltrimethoxysilane was added and mixed for 15 minutes, and then re-dried at 120°C to prepare inorganic external additive 1.

[0418] <<Preparation of Inorganic External Additive 2>> First, silica particles manufactured by the liquid-phase method (NipSeal SP-200B, ET specific surface area 200m²) 2 100g of (manufactured by Tosoh Silica) was dispersed in 2L of water and heated to 85°C. Next, an aqueous aluminum chloride solution was added in an amount equivalent to 10% by mass of Al2O3 relative to the silica particles, and the pH was adjusted to 5.5 with an aqueous sodium hydroxide solution. After holding the mixture while stirring for 30 minutes, the mixture was filtered and the residue on the filter media was washed with water to obtain a washed cake. Next, this washed cake was dried at 120°C and then pulverized using a media-type fine grinder. Finally, 40g of the obtained powder was placed in a small mixer, 10g of isobutyltrimethoxysilane was added and mixed for 15 minutes, and then re-dried at 120°C to prepare inorganic external additive 2.

[0419] <<Preparation of Inorganic External Additive 3>> First, silica particles manufactured by the liquid-phase method (Tosoh Silica Nip Seal SP-200B ET, specific surface area 200m²) 2 100g of the substance was dispersed in 2L of water and heated to 85°C. Next, an aqueous magnesium chloride solution was added in an amount equivalent to 10% by mass of MgO relative to the silica particles. The pH was then adjusted to 5.0 with an aqueous sodium hydroxide solution, and after being held while stirring for 30 minutes, the mixture was filtered and the residue on the filter media was washed with water to obtain a washed cake. Next, the washed cake was dried at 120°C and then ground using a media-type pulverizer. Finally, 40 g of the obtained powder was placed in a small mixer, 10 g of isobutyltrimethoxysilane was added and mixed for 15 minutes, and then re-dried at 120°C to prepare inorganic external additive 3.

[0420] <<Preparation of Inorganic External Additive 4>> First, silica particles manufactured by the liquid-phase method (Tosoh Silica Nip Seal SP-200B ET, specific surface area 200m²) 2100g of (g) was dispersed in 2L of water and heated to 85°C. Next, an aqueous solution of iron chloride was added in an amount equivalent to 10% by mass in terms of FeO relative to the silica particles, and the pH was adjusted to 8.5 with an aqueous solution of sodium hydroxide. After holding with stirring for 30 minutes, the mixture was filtered and the residue on the filter media was washed with water to obtain a washed cake. Next, this washed cake was dried at 120°C and then pulverized using a media-type pulverizer. Finally, 40g of the obtained powder was placed in a small mixer, 10g of isobutyltrimethoxysilane was added and mixed for 15 minutes, and then re-dried at 120°C to prepare inorganic external additive 4.

[0421] <<Preparation of Inorganic External Additive 5>> First, silica particles manufactured by the liquid-phase method (Tosoh Silica Nip Seal SP-200B ET, specific surface area 200m²) 2 100g of (g) was dispersed in 2L of water and heated to 85°C. Next, an aqueous cobalt chloride solution was added in an amount equivalent to 10% by mass in terms of CoO relative to the silica particles, and the pH was adjusted to 9.0 with an aqueous sodium hydroxide solution. After holding with stirring for 30 minutes, the mixture was filtered and the residue on the filter media was washed with water to obtain a washed cake. Next, this washed cake was dried at 120°C and then pulverized using a media-type fine grinder. Finally, 40g of the obtained powder was placed in a small mixer, 10g of isobutyltrimethoxysilane was added and mixed for 15 minutes, and then re-dried at 120°C to prepare inorganic external additive 5.

[0422] <<Preparation of Inorganic External Additive 6>> First, 100g of titanium dioxide was dispersed in 2L of water and heated to 85°C. Next, an aqueous solution of iron chloride was added in an amount equivalent to 10% by mass in terms of FeO relative to the titanium particles. The pH was adjusted to 8.5 with an aqueous solution of sodium hydroxide, and the mixture was held while stirring for 30 minutes. After filtration, the residue on the filter media was washed with water to obtain a washed cake. Next, this washed cake was dried at 120°C and then pulverized using a media-type pulverizer. Finally, 40g of the obtained powder was placed in a small mixer, 10g of isobutyltrimethoxysilane was added and mixed for 15 minutes, and then re-dried at 120°C to prepare inorganic external additive 6.

[0423] <<Preparation of Inorganic External Additive 7>> First, silica particles manufactured by the liquid-phase method (Tosoh Silica Nip Seal SP-200B ET, specific surface area 200m²) 2 100g of (g) was dispersed in 2L of water and heated to 85°C. Next, an aqueous aluminum chloride solution was added in an amount equivalent to 10% by mass of Al2O3 relative to the silica particles, and the pH was adjusted to 5.5 with an aqueous sodium hydroxide solution. After holding with stirring for 30 minutes, the mixture was filtered and the residue on the filter media was washed with water to obtain a washed cake. Next, this washed cake was dried at 120°C and then pulverized using a media-type pulverizer. Finally, 40g of the obtained powder was placed in a small mixer, 10g of decyltrimethoxysilane was added and mixed for 15 minutes, and then re-dried at 120°C to prepare inorganic external additive 7.

[0424] <<Preparation of Inorganic External Additive 8>> First, 100g of titanium dioxide was dispersed in 2L of water and heated to 85°C. Next, Al2O3 was applied to the titanium particles. exchange An aqueous solution of aluminum chloride was added in an amount equal to 10% by mass by calculation, and the pH was adjusted to 9.0 with an aqueous solution of sodium hydroxide. After holding the mixture while stirring for 30 minutes, the mixture was filtered, and the residue on the filter media was washed with water to obtain a washing cake. Next, this washing cake was dried at 120°C and then pulverized using a media-type pulverizer to prepare inorganic external additive 8.

[0425] <<Preparation of Inorganic External Additive 9>> First, silica particles manufactured by the liquid-phase method (Tosoh Silica Nip Seal SP-200B ET, specific surface area 200m²) 2 100g of (g) was placed in a small mixer, 10g of isobutyltrimethoxysilane was added and mixed for 15 minutes, and then re-dried at 120°C to prepare external additive 9.

[0426] Table 1 shows the details of the inorganic external additives used.

[0427] [Table 1]

[0428] (Example 1) <Manufacturing of composite resin particles (C-1)> A dispersion was obtained by adding 165 parts by mass of deionized water, a mixture of 5 parts by mass of fine particle dispersion (W-1) and 10 parts by mass of fine particle 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 them together. Next, 71 parts by mass of amorphous polyester resin (b-1), 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 (α2b-1) solution and 0.3 parts by mass of isophorone diamine as a curing agent (β) were added and mixed to obtain a mixed solution. This mixture was added entirely to the dispersion prepared earlier, and stirred for 2 minutes in 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.

[0429] The aqueous dispersion of composite resin particles is a composite resin particle in which fine particles containing resin fine particles (A-1) are attached to resin particles (B'-1) which contain amorphous polyester resin (b-1) and amorphous polyurethane resin (b-2) composed of a reaction product of reactive prepolymer (α2b-1) and isophorone diamine. The fact that the resin particles contained in the aqueous dispersion of composite resin particles are composite resin particles (C-1) in which resin microparticles (A-1) and other microparticles attached to resin particles (B'-1) was confirmed by magnified observation of the shape of the particles contained in the aqueous dispersion of composite resin particles using a scanning electron microscope (SU-8230, manufactured by Hitachi High-Technologies Corporation).

[0430] Next, sodium hydroxide was added to the aqueous dispersion of composite resin particles so that the pH became 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 make a reslurry. The process of centrifuging and reslurrying 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 [toner matrix particles 1].

[0431] To [Toner matrix particles 1], 100 parts by mass of toner matrix particles, 1.5 parts by mass of hydrophobic silica particles with an average particle size of 50 nm, and 1.0 part by mass of inorganic external additive 1 were mixed using a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) to obtain [Toner 1].

[0432] (Example 2) In Example 1, 15 parts by mass of a mixture of 5 parts by mass of fine particle dispersion (W-1) and 10 parts by mass of fine particle dispersion (W0-1) was changed to 15 parts by mass of a mixture of 7.5 parts by mass of fine particle dispersion (W0-1) and 7.5 parts by mass of fine particle dispersion (W0-1) to obtain [Toner matrix particles 2]. [Toner matrix particles 2] was subjected to external additive treatment in Example 1, with inorganic external additive 1 changed to inorganic external additive 2, to obtain [Toner 2]. Evaluation was carried out in the same manner as in Example 1, except that [Toner 2] was used.

[0433] (Example 3) In Example 1, 15 parts by mass of a mixture of 5 parts by mass of fine particle dispersion (W-1) and 10 parts by mass of fine particle dispersion (W0-1) was changed to 15 parts by mass of a mixture of 10 parts by mass of fine particle dispersion (W-1) and 5 parts by mass of fine particle dispersion (W0-1) to obtain [toner matrix particles 3]. [Toner matrix particles 3] was subjected to external additive treatment in Example 1, with inorganic external additive 1 replaced by inorganic external additive 3 to obtain [toner 3]. Evaluation was carried out in the same manner as in Example 1, except that [toner 3] was used.

[0434] (Example 4) In Example 3, inorganic external additive 3 was replaced with inorganic external additive 4, and the external additive treatment was performed to obtain [Toner 4]. The evaluation was carried out in the same manner as in Example 1, except that [Toner 4] was used.

[0435] (Example 5) In Example 3, inorganic external additive 3 was replaced with inorganic external additive 5, and the external additive treatment was performed to obtain [Toner 5]. The evaluation was carried out in the same manner as in Example 1, except that [Toner 5] was used.

[0436] (Example 6) In Example 3, inorganic external additive 3 was replaced with inorganic external additive 6, and the external additive treatment was performed to obtain [Toner 6]. The evaluation was carried out in the same manner as in Example 1, except that [Toner 6] was used.

[0437] (Example 7) In Example 3, inorganic external additive 3 was replaced with inorganic external additive 7, and the external additive treatment was performed to obtain [Toner 7]. The evaluation was carried out in the same manner as in Example 1, except that [Toner 7] was used.

[0438] (Example 8) In Example 3, inorganic external additive 3 was replaced with inorganic external additive 8, and the external additive treatment was performed to obtain [Toner 8]. The evaluation was carried out in the same manner as in Example 1, except that [Toner 8] was used.

[0439] (Comparative Example 1) In Example 3, inorganic external additive 3 was replaced with inorganic external additive 9, and the external additive treatment was performed to obtain [Toner 9]. The evaluation was carried out in the same manner as in Example 1, except that [Toner 9] was used.

[0440] (Comparative Example 2) In Example 1, 15 parts by mass of a mixture of 5 parts by mass of fine particle dispersion (W-1) and 10 parts by mass of fine particle dispersion (W0-1) was changed to 15 parts by mass of a 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) to obtain [toner matrix particles 4]. [Toner matrix particles 4] was subjected to external additive treatment by changing inorganic external additive 1 in Example 1 to inorganic external additive 2 to obtain [toner 10]. Evaluation was carried out in the same manner as in Example 1, except that [toner 10] was used.

[0441] (Comparative Example 3) In Example 1, 15 parts by mass of a mixture of 5 parts by mass of fine particle dispersion (W-1) and 10 parts by mass of fine particle dispersion (W0-1) was changed to 15 parts by mass of a mixture of 11.25 parts by mass of fine particle dispersion (W-1) and 3.75 parts by mass of fine particle dispersion (W0-1) to obtain [toner matrix particles 5]. [Toner matrix particles 4] was subjected to external additive treatment by changing external additive 1 in Example 1 to external additive 2 to obtain [toner 11]. Evaluation was carried out in the same manner as in Example 1, except that [toner 11] was used.

[0442] <Career Creation> To 100 parts by mass of toluene, 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 and dispersed in a homomixer for 20 minutes to prepare a resin layer coating solution. Using a fluidized bed coating apparatus, the resin layer coating solution was applied to the surface of 1,000 parts by mass of spherical magnetite with a volume average particle size of 50 μm to prepare a [carrier].

[0443] <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.

[0444] The coverage rate of resin microparticles on the surface of toner matrix particles was determined as follows: the resin microparticles on the surface of the toner matrix were observed using a scanning electron microscope (SEM), and the area ratio of the resin microparticles to the area of ​​the toner matrix was calculated using image processing software on the captured images.

[0445] The resin microparticles were observed after removing as many external additives as possible using ultrasonic treatment to create a state similar to that of toner matrix particles.

[0446] <Measurement of distance between resin microparticles> -Method for releasing external additives- [1] 50 ml of a 5% aqueous solution containing a surfactant (product name Neugen ET-165, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added to a 100 ml screw-top 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 particles obtained in (1) were observed using a scanning electron microscope (SEM) under the following observation conditions. First, the backscattered electron image was observed to detect Si-containing additives and fillers. (3) The image from (1) was binarized using image processing software (ImageJ) to remove the external additive and filler.

[0447] Next, a secondary electron image was observed at the same position as in (1). Since resin nanoparticles were 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 nanoparticles present in the parts other than the residual additive and filler (the parts other than those excluded in (3)) were identified as resin nanoparticles and observed.

[0448] [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

[0449] Next, using toners 1 to 8, toners 9 to 11, and the developer, the low-temperature fixing properties, heat-resistant storage properties, additive filming resistance, and electrostatic stability were evaluated as follows. The results are shown in Table 2.

[0450] <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 the above weight density. In this case, a printer with the heat fuser removed was used to spread the powder onto the paper. Other methods may be used as long as the powder can be spread evenly at the above weight density. The paper with the powder was 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 the specified conditions, and the low-temperature fixation performance was evaluated based on the following cold offset evaluation criteria. A lower cold offset occurrence temperature indicates better low-temperature fixation performance. [Cold Offset Evaluation Criteria] A: The minimum fixing temperature is 130°C or lower. B: The minimum fixing temperature is greater than 130°C and 135°C or lower. C: The minimum fixing temperature is greater than 135°C and 140°C or lower. D: The minimum fixing temperature is greater than 140°C.

[0451] <Heat-resistant storage stability> Each toner was stored at 50°C for 8 hours, then sieved through a 42-mesh sieve for 2 minutes. The remaining percentage on the sieve was measured, and the heat-resistant storage properties were evaluated according to the following criteria. Note that a toner with better heat-resistant storage properties has a lower remaining percentage. [Evaluation Criteria] A: The survival rate is less than 5%. B: The survival rate is 5% or more but less than 15%. C: The survival rate is between 15% and 30%. D: The survival rate is 30% or higher.

[0452] <Filming resistance of additives (inorganic microparticles)> Using an image forming apparatus (imageo MP C5002, manufactured by Ricoh Co., Ltd.), 5,000 vertical band charts with an image area ratio of 30% were printed at a rate of 3 prints per job (A4 size, landscape orientation) in a laboratory environment of 27°C and 90% RH. Next, 5,000 blank sheets (A4 size, landscape orientation) were printed at a rate of 3 prints per job. After printing one halftone image, the photoreceptor was visually observed, and the filming resistance of the additive was evaluated according to the following evaluation criteria. [Evaluation Criteria] A: There are no defects in the photoconductor. There are no quality issues whatsoever. B: There is a slight filming in the direction of printing, but it is at a level that does not affect the quality of the image, so it is not a problem. C: Filming is clearly present in the photosensitive element, and the image quality is at a level where there are problems.

[0453] <Static Stability> A durability test was conducted using each developer, printing 100,000 consecutive character image patterns with an image area ratio of 12%, and evaluating the change in charge during this test. A small amount of developer was taken from the developer sleeve, and the change in charge was determined using the blow-off method and evaluated according to the following criteria. A rating of "C" or higher indicates a level suitable for practical use. [Evaluation Criteria] A: Change in charge is less than 3 μC / g B: Change in charge is between 3 μC / g and less than 6 μC / g C: Change in charge is between 6 μC / g and less than 10 μC / g D: Change in charge is 10 μC / g or more

[0454] [comprehensive evaluation] The overall evaluation was based on the following criteria: A was assigned if all evaluation items were A; B was assigned if 1 to 3 evaluation items were A and the rest were B; C was assigned if 2 or fewer evaluation items were B and the rest were C; and D was assigned if all evaluation items were D. (Evaluation Criteria) A: Excellent B: Excellent C: Slightly better than before D: Not practical for use

[0455] [Table 2]

[0456] As shown in Table 2, in Examples 1 to 8, excellent results were obtained in terms of low-temperature fixability, heat resistance, additive filming resistance, and electrostatic stability. By controlling the coverage rate of resin fine particles on the toner matrix surface and the surface treatment agent of the inorganic external additive, it was possible to maintain high low-temperature fixability, heat resistance, and electrostatic stability, while also controlling the amount of released inorganic external additive appropriately, thereby improving the filming properties of the additive.

[0457] In contrast, in Comparative Example 1, the inorganic external additive was not coated with a hydroxide of a metal element, resulting in low electrostatic stability. Furthermore, because no interaction occurred between the hydroxyl groups and the resin fine particles, the amount of external additive released increased, leading to a deterioration in the additive's filming resistance.

[0458] In Comparative Example 2, the high coverage rate of the resin microparticles hardened the surface of the toner matrix particles, preventing the additive, including the inorganic external additive, from being properly mixed onto the toner matrix surface. As a result, the amount of free inorganic external additive increased, worsening the additive's filming resistance, and the weak mixing strength of the inorganic external additive led to poor electrostatic stability.

[0459] In Comparative Example 3, the coating rate of the resin microparticles was low, resulting in a soft surface on the toner matrix particles. This allowed the additives, including the inorganic external additive, to become embedded in the toner matrix surface. Consequently, the inorganic external additive inhibited low-temperature fixation, reducing its effectiveness as a spacer and worsening heat resistance.

[0460] Therefore, unlike the toners of Comparative Examples 1 to 3, the toners of Examples 1 to 8 have a coating rate of 30% to 70% of organic resin fine particles, and the inorganic external additive coats the oxide surface of the metal element with a hydroxide of the metal element. This results in excellent low-temperature fixability, heat resistance, and electrostatic stability, as well as suppression of contamination of the cleaning material and photoreceptor, making it possible to manufacture high-quality toner.

[0461] As described above, embodiments have been explained, but these embodiments are presented as examples only, and the present invention is not limited by these embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, and modifications are possible without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]

[0462] 10. Electrostatic latent image carrier (photoreceptor drum) 20. Charging roller (charging part) 30 Exposure apparatus (exposure unit) 40. Developing device (developing unit) 50 Intermediate transfer material (intermediate transfer belt) 60 Cleaning device (cleaning section) 70 Transfer roller (transfer section) 80 Static elimination lamp (static elimination unit) 100A, 100B, 100C image forming device [Prior art documents] [Patent Documents]

[0463] [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 [Patent Document 4] Japanese Patent Publication No. 2007-233030

Claims

1. A toner having multiple resin microparticles and inorganic external additives on the surface of toner matrix particles containing a binder resin, a colorant, and a wax, The coating rate of the resin fine particles is 30% to 70%. The inorganic external additive coats the surface of the oxide of the metal element with the hydroxide of the metal element. The resin fine particles contain styrene-acrylic resin, The hydroxide of the aforementioned metal element is a hydroxide of zinc, aluminum, magnesium, iron, and cobalt. The coating rate of the resin microparticles on the surface of the toner matrix particles is calculated using image processing software on an image of the resin microparticles on the surface of the toner matrix particles, after adding toner to an aqueous solution containing a surfactant and performing a liberation treatment by ultrasound, and then scanning the image with a scanning electron microscope, and the area ratio of the resin microparticles to the area of ​​the toner matrix particles.

2. The toner according to claim 1, wherein the outermost surface of the inorganic external additive is coated with alkylsilane.

3. The toner according to claim 1 or 2, wherein the oxide of the metal element is silica.

4. The toner according to any one of claims 1 to 3, wherein the hydroxide of the inorganic external additive is at least one selected from the group consisting of aluminum, zinc, and magnesium.

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

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

7. Electrostatic latent image carrier, An electrostatic latent image forming means for forming an electrostatic latent image on the electrostatic latent image carrier, A developing means for developing the electrostatic latent image to form a visible image using the toner described in any one of claims 1 to 4 or the developer described in claim 5, A transfer means for transferring the visible image onto a recording medium, An image forming apparatus having fixing means for fixing the transferred image transferred onto the recording medium.

8. An electrostatic latent image formation step in which an electrostatic latent image is formed on an electrostatic latent image carrier, A developing step of developing the electrostatic latent image to form a visible image using the toner described in any one of claims 1 to 4 or the developer described in claim 5, A transfer step of transferring the visible image onto a recording medium, An image forming method comprising a fixing step of fixing the transferred image onto the recording medium.

Images