Toner

Abstract

The present invention relates to a toner. A toner comprising toner particles containing a binder resin, a hydrocarbon wax A, and an ester wax B, wherein, assuming that, in a heating IR measurement in which the toner is held at 100°C for 10 minutes, the ratio of the peak intensity attributable to the hydrocarbon wax A to the peak intensity attributable to the binder resin is I, wherein the initial peak intensity ratio when heated to 100°C is represented by I(ini), and the peak intensity ratio when heated to 100°C and held for 10 minutes is represented by I(10 minutes), then I(ini) and I(10 minutes) satisfy the following formula (1): I(ini) / I(10 minutes)≤0.95 (1).

Description

Technical Field

[0001] The present disclosure relates to a toner used in an image forming method such as electrophotography. Background Art

[0002] In recent years, user demands for higher speeds, higher image quality, and longer lifespans in electrophotographic image forming devices, such as copiers and printers, have been growing. Furthermore, energy conservation has gained increasing attention due to the growing momentum of global environmental protection. Furthermore, the number of users who prioritize duplex printing has increased due to the global trend toward resource conservation, and stable performance is required across a wide variety of user environments.

[0003] From a space-saving perspective, miniaturization of the main body is required. To achieve this, it is essential to optimally arrange the components to eliminate dead space and minimize the number of components required. Cooling fans and air ducts are potential candidates for reduction. In such cases, heat within the main body becomes difficult to cool. Furthermore, as printing speeds increase, sheets printed with toner will gradually accumulate on the output tray without cooling due to the heat generated during fusing.

[0004] The performance required of toners used in these types of electrophotographic image forming devices requires improved low-temperature fixability and the prevention of sheet adhesion in the paper output tray. As mentioned above, due to the miniaturization and high-speed operation of printed paper, when printed sheets are stacked on the output tray without cooling, the toner does not solidify on the output tray, resulting in a tendency for the stacked sheets to become clingy. This effect is particularly pronounced when toners with improved low-temperature fixability melt at relatively low temperatures.

[0005] For example, Japanese Patent Application Laid-Open No. 2019-086642 proposes a toner in which a wax with high plasticity for a binder resin and a wax with high releasability are used in combination to improve low-temperature fixing property so that the binder resin can be easily melted.

[0006] Furthermore, Japanese Patent Application Laid-Open No. 2018-173499 proposes a toner that includes a wax with high plasticity for the binder resin and a crystalline polyester resin, and controls the storage elastic modulus at 100°C, 60°C, and 50°C within certain ranges, thereby simultaneously achieving improved low-temperature fixability and suppressed output paper sticking. These technologies are somewhat effective in simultaneously achieving improved low-temperature fixability and suppressed output paper sticking. Summary of the Invention

[0007] Although low-temperature fixing property is greatly improved by the technology disclosed in Japanese Patent Application Laid-Open No. 2019-086642, this technology is insufficient in also achieving suppression of output paper sticking.

[0008] Further, with regard to Japanese Patent Application Laid-Open No. 2018-173499, in a miniaturized body with an increased operating speed, for example, as described above, in a usage environment in which paper is stacked on a paper output tray in a duplex printing mode, further improvements are required to simultaneously achieve low-temperature fixing ability and suppression of output paper adhesion.

[0009] The present disclosure provides a toner capable of simultaneously achieving low-temperature fixability and suppression of sticking of output paper in a use environment in which paper is stacked on a paper output tray in a duplex printing mode in a main body of a compact high-speed image forming apparatus.

[0010] Specifically, a toner is provided which has good fixing properties (resistance to belt peeling) even in high-speed processing and is less likely to cause adhesion of output paper of an image in a duplex printing mode.

[0011] A toner comprising toner particles, wherein the toner particles include:

[0012] Binder resin,

[0013] Hydrocarbon wax A, and

[0014] Ester wax B, wherein

[0015] Assuming that, in a heating IR measurement in which the toner is kept at 100° C. for 10 minutes, the peak intensity ratio of the peak intensity attributable to the hydrocarbon wax A to the peak intensity attributable to the binder resin is I, the initial peak intensity ratio when heated to 100° C. is I(ini), and the peak intensity ratio when heated to 100° C. and kept for 10 minutes is I(10 minutes),

[0016] Then the I(ini) and the I(10 minutes) satisfy the following formula (1):

[0017] I(ini) / I(10 minutes)≤0.95 (1).

[0018] The present disclosure can provide a toner capable of simultaneously achieving low-temperature fixability and suppression of sticking of output paper in a use environment in which paper is stacked on a paper output tray in a duplex printing mode in a main body of a compact high-speed image forming apparatus.

[0019] Further features of the present invention will become apparent from the following description of exemplary embodiments. DETAILED DESCRIPTION

[0020] In the present disclosure, unless otherwise specified, the description "from XX to YY" or "XX to YY" indicating a numerical range refers to a numerical range including the lower limit and the upper limit as endpoints. When a numerical range is described in sections, the upper and lower limits of each numerical range can be arbitrarily combined.

[0021] The present inventors have diligently studied a toner that has excellent low-temperature fixability in a miniaturized high-speed printer and is less likely to cause image sticking when sheets are stacked on an output tray in a duplex printing mode.

[0022] For low-temperature fixing, it is essential that the toner melts instantly during high-speed processing by passing through the fixing roller. Considering the balance between storage stability and durability, the inclusion of a finely dispersed crystalline material, namely a wax that plasticizes the binder resin, within the toner particles allows for melting even at low temperatures during high-speed processing. Furthermore, the inclusion of a release wax allows the wax to migrate to the surface of the image during fixing and exert a release effect on the fixing roller, thus enabling low-temperature fixing.

[0023] It's important to strike a balance between the amounts of these waxes. If the amount of plasticizing wax is too small, the melting effect at low temperatures won't be achieved, while if the amount is too large, heat-resistant storage stability will decline and hot offset will occur during fusing. Regarding hot offset, release wax ensures releasability from the fusing roller, but if the amount is too small, the release effect won't be achieved, while if the amount is too large, the release effect will be achieved even between sheets, hindering fusing.

[0024] In other words, since both the plasticizing wax and the releasing wax play their respective roles in optimum amounts and timings, low-temperature fixability can be achieved even in miniaturized equipment and high-speed processes.

[0025] However, it has become difficult to suppress the sticking of output paper during duplex printing because of the improved low-temperature fixability of the toner. When continuous printing is performed in duplex mode and paper is stacked on the output tray in a downsized and high-speed printer, the paper temperature immediately after output can reach approximately 100°C, and the temperature near the center of the paper bundle can reach approximately 80°C.

[0026] It has been found that in such cases, the heat does not easily cool down, and the printed toner remains warm for more than 10 minutes, although this depends on the basis weight of the stacked paper and the number of stacked sheets. In this state, the wax melts and the toner remains soft, so that toner-to-paper sticking of output paper (which tends to occur in duplex printing of text images) and toner-to-toner sticking of output paper (which tends to occur in duplex printing of solid images) tend to occur in the stacked sheets.

[0027] To address these issues, the inventors focused on the role of release wax. Specifically, they reasoned that maximizing the release effect of release wax would prevent sticking of output paper, even when toner is molten in the paper bundle on the output tray. Therefore, they investigated the behavior of release wax from the fuser nip to the paper output tray.

[0028] The results confirmed that while the release wax migrates to the toner surface during fixing and exerts a release effect on the surface of the fixing roller, the majority of the release wax migrates to the fixing roller during contact. Therefore, the inventors believe that the amount of release wax remaining on the image surface decreases, making it difficult for the toner to exert a release effect when the paper is stacked on the output tray while the toner is in a molten state.

[0029] Meanwhile, simply increasing the amount of release wax in toner particles to maintain the release effect even on the paper output tray improves the release effect from paper as described above, but reduces fixability. Furthermore, if the amount of release wax is too large, the toner quality is adversely affected, resulting in reduced durability.

[0030] Therefore, the inventors have proposed a method for gradually controlling the amount of release wax that migrates to the toner surface in order to simultaneously achieve low-temperature fixability and suppress output paper sticking. Specifically, the inventors have devised a toner in which only a necessary and sufficient amount of release wax migrates to the toner surface during the fixing nip, and the amount of release wax on the surface can be increased by allowing the release wax to subsequently be placed on the paper output tray in a heat-storing state. They have discovered that this allows the release wax to effectively exhibit its release effect both in the fixing nip and when paper is stacked on the paper output tray. This effect allows for simultaneous low-temperature fixability and suppression of output paper sticking during duplex printing.

[0031] That is, it was found that both the low-temperature fixability and the suppression of output paper adhesion at the time of duplex printing were improved by including a release wax and a plasticizing wax in toner particles, and, with respect to the amount of the release wax on the toner surface, controlling the amount of the release wax that migrates to the toner surface from immediately after heating to 100° C. to 10 minutes later within a specific range; and this finding led to the completion of the above-mentioned toner.

[0032] That is, the present disclosure relates to a toner comprising toner particles containing a binder resin, a hydrocarbon wax A, and an ester wax B, wherein

[0033] Assuming that, in a heating IR measurement in which the toner is kept at 100° C. for 10 minutes, the peak intensity ratio of the peak intensity attributed to the hydrocarbon wax A to the peak intensity attributed to the binder resin is I,

[0034] Wherein the initial peak intensity ratio when heated to 100°C is represented by I(ini), and the peak intensity ratio when heated to 100°C and maintained for 10 minutes is represented by I(10 minutes), then I(ini) and I(10 minutes) satisfy the following formula (1).

[0035] I(ini) / I(10 minutes)≤0.95 (1)

[0036] The details of the heating IR measurement will be described below, but this method makes it possible to capture changes in the amount of hydrocarbon wax A on the toner surface during heating. The I value is the ratio of the peak intensity attributable to hydrocarbon wax A to the peak intensity attributable to the binder resin in the heating IR measurement, and is an indicator of the amount of hydrocarbon wax A on (near) the toner surface.

[0037] The initial peak intensity ratio when heated to 100°C is represented by I(ini), and the peak intensity ratio when heated to 100°C and held for 10 minutes is represented by I(10min). It is necessary that the value of I(ini) and the value of I(10min) satisfy the formula (1).

[0038] When I(ini) / I(10 minutes) is 0.95 or less, a portion of the hydrocarbon wax A, which has a release effect, migrates to the toner surface in the fixing roller nip, exerting a release effect on the fixing roller. The hydrocarbon wax A then gradually migrates to the surface, allowing it to be placed on the paper output tray in a heat-storage state. This release effect is achieved even between stacked images, and sticking of output paper can be suppressed even during duplex printing. Furthermore, I(ini) / I(10 minutes) is preferably 0.94 or less, and more preferably 0.93 or less. The lower limit of I(ini) / I(10 minutes) is not particularly limited, but is preferably 0.70 or greater, more preferably 0.78 or greater, and even more preferably 0.80 or greater.

[0039] As one of means for developing the above-mentioned characteristics, it is preferable that the toner particles include inorganic particles C hydrophobized with a hydrophobizing agent. The hydrophobizing agent preferably has an alkyl chain.

[0040] Then, for the migration control of the hydrocarbon wax A, it is preferable to control the SP value of the alkyl chain of the hydrophobizing agent in the hydrocarbon wax A, the ester wax B, and the inorganic particles C.

[0041] Furthermore, in order to set I(ini) / I(10 minutes) within a preferred range, it is preferred that ΔSP1 and ΔSP2 satisfy the following formulas (2) to (4).

[0042] ΔSP1 is the SP value of hydrocarbon wax A (SPa) (cal / cm 3 ) 1 / 2 The SP value (SPc) (cal / cm2) of the alkyl chain of the hydrophobizing agent in the inorganic particles C 3 ) 1 / 2 The difference between (SPa-SPc).

[0043] Furthermore, ΔSP2 is the SP value (SPb) of ester wax B (cal / cm 3 ) 1 / 2 The difference between the SP value (SPa) of hydrocarbon wax A and the SP value (SPb-SPa).

[0044] ΔSP1-ΔSP2≤0.10 (2)

[0045] 0.41≤ΔSP2≤1.00 (3)

[0046] 0.10≤ΔSP1≤0.82 (4)

[0047] The SP value is also called the solubility parameter and is a numerical value used as an indicator of solubility or affinity to express how much a substance dissolves in a certain substance. Those with similar SP values ​​have high solubility and affinity, and those with different SP values ​​have low solubility and affinity. The SP value is calculated based on the commonly used Fedors method [Poly. Eng. Sci., 14 (2) 147 (1974)]. The unit of the SP value is (cal / cm 3 ) 1 / 2 .

[0048] The SP value (SPa) of hydrocarbon wax A is generally about 8.30 to 8.50. By designing the SP value of hydrocarbon wax A, the SP value of ester wax B, and the SP value of the alkyl chain of the hydrophobizing agent in inorganic particles C within the above ranges, the amount of hydrocarbon wax on (near) the surface of the toner after heating at 100° C. for 10 minutes can be easily increased.

[0049] By satisfying formula (3), hydrocarbon wax A has an affinity with ester wax B, so that migration to the toner surface during fixing is suppressed, and hydrocarbon wax A is retained inside. When ΔSP2 is set to 0.41 or more, the waxes are not mixed and remain in the form of domains, and by setting ΔSP2 to 1.00 or less, appropriate affinity is achieved.

[0050] Since ester wax B is compatible with the binder resin, ester wax B is mixed with the binder resin in a molten state at a high temperature. Therefore, hydrocarbon wax A functions to be retained inside by ester wax B. ΔSP2 is more preferably 0.43 to 0.60.

[0051] By setting ΔSP1 within the range of 0.10 to 0.82, hydrocarbon wax A adheres to the inorganic particles C due to its affinity for the alkyl chains of the hydrophobizing agent. Setting ΔSP1 to 0.10 or greater prevents complete mixing of hydrocarbon wax A and the inorganic particles, while setting ΔSP1 to 0.82 or less allows for optimal affinity. ΔSP1 is more preferably 0.15 to 0.55.

[0052] Furthermore, by setting the relationship ΔSP1 - ΔSP2 ≤ 0.10, a difference in interaction is achieved, establishing a gradient. As a result, a driving force is generated that simultaneously pulls hydrocarbon wax A toward inorganic particles C, while hydrocarbon wax A is attracted to ester wax B and inorganic particles C. This driving force causes hydrocarbon wax A, which remains within the toner, to be transferred to the surface of an image, which is then placed on the paper output tray in a heat-storage state, due to its affinity for ester wax B or inorganic particles C. ΔSP1 - ΔSP2 is more preferably 0.08 or less. The lower limit is not particularly limited, but is preferably -0.60 or greater, and more preferably -0.50 or greater.

[0053] It is preferable to set the SP value of each component within the above range so as to satisfy the relationship of formula (1).

[0054] By establishing the relationship of formula (1), only the amount of hydrocarbon wax A necessary and sufficient for release from the fixing roller is transferred to the toner surface, thereby exhibiting a release effect during fixing. Furthermore, hydrocarbon wax A migrates to the toner surface in an image allowed to be placed in a heat storage state in a paper bundle stacked on a paper output tray, so that sticking of output paper is also suppressed.

[0055] The toner particles include ester wax B. Ester wax B plasticizes the binder resin during fixing and is essential for achieving low-temperature fixing. The plasticizing effect of ester wax B is achieved by compatibility with the binder resin. Ester wax B is not particularly limited as long as it has the aforementioned properties, and known waxes can be used.

[0056] For example, in addition to monofunctional ester waxes, polyfunctional ester waxes such as difunctional ester waxes or tetrafunctional or hexafunctional ester waxes can also be used. Specific examples include esterification products of alcohol components, such as monofunctional alcohols such as lauryl alcohol, stearyl alcohol, and behenyl alcohol; difunctional alcohols such as ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,4-butanediol, and 1,6-hexanediol; and polyfunctional alcohols such as glycerol, pentaerythritol, and dipentaerythritol; and aliphatic monocarboxylic acids such as palmitic acid, stearic acid, and behenic acid.

[0057] The carbon number of the hydrocarbon chain of the long-chain fatty acid or alcohol is preferably 10 to 30, and more preferably 12 to 24. In particular, difunctional ester wax is preferred, and the SP value described later is preferably in the range of 7.0 to 10.0, and more preferably 8.4 to 9.0.

[0058] The molecular weight of the ester wax B is preferably 500 to 1000, and more preferably 550 to 800. By setting the molecular weight within this range, the plasticizing effect on the binder resin is increased, and the contribution to low-temperature fixing property is increased. Specifically, an ester compound composed of a diol and an aliphatic monocarboxylic acid is more preferred.

[0059] Further, the ester wax B is preferably an ester compound of a diol having 2 to 6 carbon atoms and an aliphatic monocarboxylic acid having 16 to 22 carbon atoms.

[0060] Examples of the diol having 2 to 6 carbon atoms include ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,6-hexanediol, and the like.

[0061] Examples of the aliphatic monocarboxylic acid having 16 to 22 carbon atoms include aliphatic monocarboxylic acids such as palmitic acid, stearic acid, behenic acid and the like.

[0062] The amount of the ester wax B in the toner particles is preferably 1.0 to 45.0 parts by mass, more preferably 5.0 to 35.0 parts by mass, and even more preferably 10.0 to 30.0 parts by mass, relative to 100.0 parts by mass of the binder resin.

[0063] The analysis method of the molecular weight of the ester wax B is not particularly limited, and any method suitable for detecting the mass of the ester wax can be used. Specific examples include a method of detecting molecular ions by using a mass spectrometer ISQ manufactured by Thermo Fisher Scientific Inc. and a direct data import method, and a method of detecting molecular ions by using 2,5-dihydroxybenzoic acid (DHBA) as a matrix and sodium trifluoroacetate as an ionizing agent with a MALDI-TOFMS manufactured by Bruker Daltonics Co.

[0064] The SP value (SPb) of the ester wax B is preferably 8.60 to 9.20, and more preferably 8.80 to 9.00.

[0065] Furthermore, the toner particles include hydrocarbon wax A. As described above, hydrocarbon wax A exerts a release effect on the surface of the fixing roller in the fixing nip, and therefore it is necessary to ensure the release effect between toner and paper and between toner and toner in an image that is allowed to be placed on a paper output tray in a heat storage state.

[0066] Known hydrocarbon waxes can be used as the hydrocarbon wax A, and examples thereof include petroleum waxes, hydrocarbon waxes, and polyolefin waxes, etc. For example, low molecular weight polyethylene, low molecular weight polypropylene, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax can be mentioned.

[0067] The amount of the hydrocarbon wax A in the toner particles is preferably 0.5 to 20.0 parts by mass, more preferably 3.0 to 15.0 parts by mass, and even more preferably 4.0 to 10.0 parts by mass, relative to 100.0 parts by mass of the binder resin.

[0068] Further, it is preferred that the toner particles include the hydrophobized inorganic particles C.

[0069] Examples of the inorganic particles include metal oxides of metals such as Fe, Si, Ti, Sn, Zn, Al, and Ce, and known particles can be used. The coating method of the surface of the inorganic particles is not particularly limited as long as it is a treatment method using a surface hydrophobizing treatment agent.

[0070] Examples of suitable methods include: a wet method in which the powder to be treated is dispersed in a solvent such as water or an organic solvent using a mechanochemical mill such as a ball mill or a sand mill, followed by mixing with a hydrophobizing agent, removing the solvent and drying; a dry method in which the powder to be treated and the hydrophobizing agent are mixed using a Henschel mixer or a super mixer, and then dried; a method in which the powder to be treated and the surface hydrophobizing agent are brought into contact with each other in a high-speed air flow of a jet mill or the like for treatment; a method in which the adhesion between the particle surface and the hydrophobizing agent is improved while the particles are deagglomerated by the shearing action and compression action of a wheel-type mixer such as Mix-Muller; and the like.

[0071] Furthermore, it is more preferred that the hydrophobized inorganic particles C are magnetic.

[0072] Examples of magnetic bodies include magnetic iron oxides such as magnetite, hematite, ferrite, and magnetic iron oxides including other metal oxides; metals such as Fe, Co and Ni, or alloys of these metals with metals such as Al, Co, Cu, Pb, Mg, Ni, Sn, Zn, Sb, Be, Bi, Cd, Ca, Mn, Se, Ti, W and V, and mixtures thereof.

[0073] Among them, magnetite is preferred. Magnetite can have a polyhedron, octahedron, hexahedron, sphere, needle, or flake shape, but from the viewpoint of improving image density by suppressing cohesion, shapes such as hexahedron and sphere that ensure a small contact area between magnetic bodies are preferred.

[0074] The number average particle diameter of the primary particles of the inorganic particles C is preferably 50 nm to 500 nm, more preferably 100 nm to 300 nm, and further preferably 150 nm to 250 nm.

[0075] When the inorganic particles C are a magnetic body, the amount of the magnetic body is preferably 35 parts by mass to 100 parts by mass, and more preferably 45 parts by mass to 95 parts by mass, relative to 100 parts by mass of the binder resin.

[0076] The amount of the magnetic body in the toner can be measured using a thermal analyzer TGAQ5000IR manufactured by PerkinElmer Corp. In the measurement method, the toner is heated from room temperature to 900° C. at a heating rate of 25° C. / min in a nitrogen atmosphere, the mass loss between 100° C. and 750° C. is set as the mass of the toner components excluding the magnetic body, and the remaining mass is regarded as the mass of the magnetic body.

[0077] The following methods can be cited as methods for producing a magnetic body.

[0078] An aqueous solution containing ferrous hydroxide is prepared by adding an alkali such as sodium hydroxide in an amount equal to or greater than the amount of the iron component to an aqueous solution of a ferrous salt. Air is blown into the prepared aqueous solution while maintaining the pH of the aqueous solution at pH 7 or higher, and an oxidation reaction of the ferrous hydroxide is carried out while the aqueous solution is heated to 70° C. or higher, thereby first forming seed crystals that form the cores of the magnetic body.

[0079] Next, an aqueous solution containing 1 equivalent of ferrous sulfate based on the amount of alkali previously added is added to the slurry liquid containing the seed crystals. While blowing air and maintaining the pH of the liquid at 5 to 10, the reaction of ferrous hydroxide is promoted, and magnetic iron oxide particles grow around the seed crystals. At this time, the shape and magnetic properties of the magnetic body can be controlled by selecting any pH, reaction temperature and stirring conditions. As the oxidation reaction proceeds, the pH of the liquid moves toward the acidic side, but it is preferred that the pH of the liquid does not become less than 5. The magnetic body can be obtained by filtering, washing and drying the magnetic iron oxide particles thus obtained by conventional methods.

[0080] The hydrophobization treatment of the inorganic particles C is not particularly limited, but it is preferred that the inorganic particles C be surface-treated with a hydrophobization agent represented by formula (I) described later and having a relatively large number of carbon atoms.

[0081] As a result, the hydrophobizing agent can uniformly react with the particle surfaces of the inorganic particles C to achieve high hydrophobicity.

[0082] The inorganic particles C are preferably inorganic particles hydrophobized using an alkyltrialkoxysilane coupling agent represented by the following formula (I) as a hydrophobizing agent. The inorganic particles C preferably have a reaction product of the inorganic particles and the hydrophobizing agent on the surface of the inorganic particles.

[0083] C p H 2p+1 -Si-(OC q H 2q+1 )3 (I)

[0084] In formula (I), p represents an integer of 6 to 12 (preferably 8 to 12, more preferably 10 to 12), and q represents an integer of 1 to 3 (preferably 1 or 2, more preferably 1).

[0085] In the case where p in the above formula is 6 or more, sufficient hydrophobicity can be imparted, and in the case where p is 12 or less, uniform treatment can be performed on the surface of the inorganic particles, and aggregation of the inorganic particles can be favorably suppressed.

[0086] The SP value of the alkyl chain of the hydrophobizing agent in the inorganic particles C is preferably 7.50 to 8.50, and more preferably 7.80 to 8.20.

[0087] The alkyl chain of the hydrophobizing agent in the inorganic particles C preferably represents the alkyl chain of the hydrophobizing agent (and its reaction product) present on the surface of the inorganic particles C, and more preferably is an alkyl group bonded to Si of the hydrophobizing agent (and its reaction product) represented by formula (I).

[0088] The amount of the hydrophobizing agent is preferably 0.3 to 2.0 parts by mass, and more preferably 0.6 to 1.5 parts by mass, relative to 100 parts by mass of the untreated inorganic particles.

[0089] When toner is produced by the suspension polymerization method described below, hydrophobized inorganic particles, acting like a surfactant, are unevenly distributed near the surface of the toner particles. This is due to the hydrophobicity imparted by the alkyl substituents during toner formation and the hydrophilicity of residual hydroxyl groups. The presence of the magnetic material near the surface has the effect of suppressing the migration of wax onto the toner surface when the toner is stored in a harsh environment, such as 40°C and 95% RH.

[0090] When wax migrates to the toner surface when the toner is left standing, the amount of hydrocarbon wax that migrates to the surface is less likely to increase in images placed on a paper output tray in a heat-storage state. By ensuring the presence of inorganic particles close to the surface, the migration of wax to the toner surface, which occurs when the toner is left standing in a harsh environment, is suppressed, further maintaining the effect of suppressing sticking of output paper.

[0091] Further, the binder resin preferably includes a monomer unit derived from styrene in order to fully exert the plasticizing effect of the ester wax.

[0092] More preferably, the binder resin includes a styrene acrylic copolymer. The styrene acrylic copolymer is a copolymer of a styrene monomer and an acrylic monomer (acrylic acid, methacrylic acid, and alkyl esters thereof), and more preferably a copolymer of a monomer including styrene and an alkyl (meth)acrylate having 1 to 8 carbon atoms in the alkyl group, and even more preferably a copolymer of styrene, an alkyl (meth)acrylate having 1 to 8 carbon atoms in the alkyl group, and a crosslinking agent added as needed.

[0093] Here, the styrene acrylic copolymer may be contained in the binder resin in a state consisting of only the styrene acrylic copolymer, or in a state of a block copolymer or a graft copolymer with other polymers, or a mixture thereof.

[0094] By using a binder resin including a monomer unit derived from styrene, particularly a resin including a styrene acrylic copolymer, the plasticizing effect of the ester wax is strongly exerted, and the contribution to low-temperature fixing increases.

[0095] The monomer unit derived from styrene is a monomer unit represented by the following formula (St).

[0096]

[0097] The amount of styrene-derived monomer units in the binder resin is preferably 50% by mass or more, more preferably 65% ​​by mass or more, and further preferably 70% by mass or more. The upper limit is not particularly limited, but is preferably 90% by mass or less, and more preferably 80% by mass or less.

[0098] Furthermore, it is preferred that I(10 min), which is the I value after the toner is heated to 100°C and held for 10 minutes, is 0.30 or greater, more preferably 0.32 or greater, and further preferably 0.35 or greater. The upper limit is not particularly limited, but is preferably 0.60 or less, and more preferably 0.50 or less.

[0099] Satisfying the above amount and I (10 minutes) indicates that the amount of the hydrocarbon wax on the image surface in the paper output tray after fixing is sufficient to suppress sticking.

[0100] The amount of monomer units derived from styrene in the binder resin can be easily determined by nuclear magnetic resonance spectroscopy (hereinafter referred to as NMR). The toner is added to deuterated chloroform, and the NMR spectrum of the protons of the dissolved binder resin is measured. The molar ratio and mass ratio of each monomer can be calculated from the resulting NMR spectrum, and the amount of monomer units derived from styrene can be determined.

[0101] For example, in the case of a styrene acrylic copolymer, the composition ratio and mass ratio can be calculated based on a peak derived from a styrene monomer at around 6.5 ppm and a peak derived from an acrylic monomer at around 3.5 ppm to 4.0 ppm.

[0102] Further, for example, when a polyester resin generally known as a binder resin for toner is included, the peaks derived from the respective monomers constituting the polyester resin and the peak derived from the styrene acrylic copolymer are combined to calculate the molar ratio and mass ratio and determine the amount of the monomer unit derived from styrene.

[0103] Assuming that the difference (SPb-SPc) between the SP value (SPb) of the ester wax B and the SP value (SPc) of the alkyl chain of the hydrophobizing agent in the inorganic particles C is ΔSP3, ΔSP3 preferably satisfies the following formula (5):

[0104] ΔSP3≤1.05 (5).

[0105] ΔSP3 is more preferably 1.02 or less. The lower limit is not particularly limited, but is preferably 0.45 or more, and more preferably 0.55 or more. Within these ranges, low-temperature fixing property (tape releasability) tends to improve.

[0106] This is understood to be because the effect of plasticizing the binder resin is enhanced by increasing the affinity between the ester wax B and the inorganic particles C. Further, in a toner produced by a suspension polymerization method described later, the inorganic particles C tend to be unevenly present near the surface of the toner particles, but the presence ratio of the ester wax B having a high affinity therefore increases near the surface.

[0107] Since it is assumed that the melting property near the toner surface contributes more to the fixability than the internal melting property, the presence of the ester wax B having a large plasticizing effect near the toner surface significantly contributes to the improvement of the low-temperature fixability.

[0108] The toner particles may include a charge control agent.

[0109] Organic metal complex compounds and chelate compounds are effective as charge control agents for negative charging, and examples thereof include monoazo metal complex compounds; acetylacetone metal complex compounds; and metal complex compounds of aromatic hydroxycarboxylic acids or aromatic dicarboxylic acids, and the like.

[0110] Specific examples of commercially available products include Spilon Black TRH, T-77, T-95 (Hodogaya Chemical Co., Ltd.), BONTRON (registered trademark) S-34, S-44, S-54, E-84, E-88, E-89 (Orient Chemical Industry Co., Ltd.).

[0111] The charge control agents may be used alone or in combination of two or more.

[0112] From the viewpoint of the charge amount of the toner, the amount of the charge control agent is preferably 0.1 to 10.0 parts by mass, and more preferably 0.1 to 5.0 parts by mass, relative to 100 parts by mass of the binder resin.

[0113] The toner particles may include a colorant such as a pigment or a dye. These may be used alone or in combination of two or more.

[0114] Examples of black pigments include carbon black such as furnace black, channel black, acetylene black, thermal black, lamp black, etc. These may be used alone or in combination of two or more.

[0115] As a colorant suitable for yellow, a pigment or a dye can be used.

[0116] Examples of pigments include CI Pigment Yellow 1, 2, 3, 4, 5, 6, 7, 10, 11, 12, 13, 14, 15, 17, 23, 62, 65, 73, 74, 81, 83, 93, 94, 95, 97, 98, 109, 110, 111, 117, 120, 127, 128, 129, 137, 138, 139, 147, 151, 154, 155, 167, 168, 173, 174, 176, 180, 181, 183, 191, and CI Vat Yellow 1, 3, 20. Examples of dyes include CI Solvent Yellow 19, 44, 77, 79, 81, 82, 93, 98, 103, 104, 112, 162, and the like. These may be used alone or in combination of two or more.

[0117] As a colorant suitable for cyan, a pigment or a dye can be used.

[0118] Examples of the pigment include CI Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 16, 17, 60, 62, 66, etc., CI Vat Blue 6, and CI Acid Blue 45. Examples of the dye include CI Solvent Blue 25, 36, 60, 70, 93, 95, etc. These may be used alone or in combination of two or more.

[0119] As a colorant suitable for magenta, a pigment or a dye can be used.

[0120] Examples of pigments include CI Pigment Red 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 21, 22, 23, 30, 31, 32, 37, 38, 39, 40, 41, 48, 48:2, 48:3, 48:4, 49, 50, 51, 52, 53, 54, 55, 57, 57:1, 58, 60, 63, 64, 68, 81, 81:1, 83, 87, 88, 89, 90, 112, 114, 122, 123, 144, 146, 150, 163, 166, 169, 177, 184, 185, 202, 206, 207, 209, 220, 221, 238, 254, etc., CI Pigment Violet 19, and CI Vat Red 1, 2, 10, 13, 15, 23, 29, 35.

[0121] Examples of magenta dyes include oil-soluble dyes such as CI Solvent Red 1, 3, 8, 23, 24, 25, 27, 30, 49, 52, 58, 63, 81, 82, 83, 84, 100, 109, 111, 121, 122, etc., CI Disperse Red 9, CI Solvent Violet 8, 13, 14, 21, 27, etc., CI Disperse Violet 1; and basic dyes such as CI Basic Red 1, 2, 9, 12, 13, 14, 15, 17, 18, 22, 23, 24, 27, 29, 32, 34, 35, 36, 37, 38, 39, 40, etc., CI Basic Violet 1, 3, 7, 10, 14, 15, 21, 25, 26, 27, 28, etc. These may be used alone or in combination of two or more.

[0122] The amount of the colorant (excluding the inorganic particles C) is preferably 1 part by mass to 20 parts by mass, and more preferably 2 parts by mass to 15 parts by mass, relative to 100 parts by mass of the binder resin.

[0123] The toner may have toner particles and external additives.

[0124] Examples of external additives include metal oxide fine particles (inorganic fine particles) such as silica fine particles, alumina fine particles, titanium dioxide fine particles, zinc oxide fine particles, strontium titanate fine particles, cerium oxide fine particles, and calcium carbonate fine particles. Furthermore, composite oxide fine particles using two or more metals may be used, or two or more selected from the group of these fine particles may be used in any combination.

[0125] Further, resin fine particles and organic-inorganic composite fine particles of resin fine particles and inorganic fine particles can also be used.

[0126] More preferably, the external additive has at least one selected from the group consisting of silica fine particles and organic-inorganic composite fine particles.

[0127] Examples of the silica fine particles include sol-gel silica fine particles produced by a sol-gel method, aqueous silica gel fine particles, alcoholic silica fine particles, fumed silica fine particles obtained by a gas phase method, fused silica fine particles, and the like.

[0128] Examples of the resin fine particles include particles of resins such as vinyl resins, polyester resins, and silicone resins.

[0129] Examples of the organic-inorganic composite fine particles include organic-inorganic composite fine particles composed of resin fine particles and inorganic fine particles.

[0130] When using organic-inorganic composite fine particles, while maintaining good durability and charging performance due to the inorganic fine particles, the resin component having a low heat capacity does not easily hinder the aggregation of toner particles during fixing, and fixing is not easily hindered. Therefore, it is easy to achieve both durability and fixing properties.

[0131] The organic-inorganic composite fine particles are preferably composite fine particles having convex portions, in which inorganic fine particles are embedded in the surface of resin fine particles (preferably vinyl resin fine particles) as the resin component. Composite fine particles having a structure in which the inorganic fine particles are exposed on the surface of the vinyl resin particles are more preferred. Composite fine particles having a structure in which convex portions derived from the inorganic fine particles are present on the surface of the vinyl resin fine particles are even more preferred.

[0132] Examples of the inorganic fine particles constituting the organic-inorganic composite fine particles include fine particles such as silica fine particles, alumina fine particles, titania fine particles, zinc oxide fine particles, strontium titanate fine particles, cerium oxide fine particles, calcium carbonate fine particles, and the like.

[0133] The amount of the external additive is preferably 0.1 parts by mass to 20.0 parts by mass relative to 100 parts by mass of the toner particles.

[0134] The external additive may be hydrophobized with a hydrophobizing agent.

[0135] Examples of the hydrophobizing treatment agent include:

[0136] Chlorosilanes, such as methyltrichlorosilane, dimethyldichlorosilane, trimethylchlorosilane, phenyltrichlorosilane, diphenyldichlorosilane, tert-butyldimethylchlorosilane, vinyltrichlorosilane, etc.;

[0137] Alkoxysilanes, such as tetramethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, phenyltrimethoxysilane, diphenyldimethoxysilane, o-methylphenyltrimethoxysilane, p-methylphenyltrimethoxysilane, n-butyltrimethoxysilane, isobutyltrimethoxysilane, hexyltrimethoxysilane, octyltrimethoxysilane, decyltrimethoxysilane, dodecyltrimethoxysilane, tetraethoxysilane, methyltriethoxysilane, dimethyldiethoxysilane, phenyltriethoxysilane, diphenyldiethoxysilane Alkane, isobutyltriethoxysilane, decyltriethoxysilane, vinyltriethoxysilane, γ-methacryloxypropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-(2-aminoethyl)aminopropyltrimethoxysilane, γ-(2-aminoethyl)aminopropylmethyldimethoxysilane, etc.;

[0138] Silazanes, such as hexamethyldisilazane, hexaethyldisilazane, hexapropyldisilazane, hexabutyldisilazane, hexapentyldisilazane, hexahexyldisilazane, hexacyclohexyldisilazane, hexaphenyldisilazane, divinyltetramethyldisilazane, dimethyltetravinyldisilazane, etc.;

[0139] Silicone oils, such as dimethyl silicone oil, methyl hydrogen silicone oil, methylphenyl silicone oil, alkyl-modified silicone oil, chloroalkyl-modified silicone oil, chlorophenyl-modified silicone oil, fatty acid-modified silicone oil, polyether-modified silicone oil, alkoxy-modified silicone oil, carbinol-modified silicone oil, amino-modified silicone oil, fluorine-modified silicone oil, terminal reactive silicone oil, etc.;

[0140] Siloxanes, such as hexamethylcyclotrisiloxane, octamethylcyclotetrasiloxane, decamethylcyclopentasiloxane, hexamethyldisiloxane, octamethyltrisiloxane, etc.;

[0141] Fatty acids and metal salts thereof, for example, long-chain fatty acids such as undecanoic acid, lauric acid, tridecanoic acid, dodecanoic acid, myristic acid, palmitic acid, pentadecanoic acid, stearic acid, heptadecanoic acid, arachidic acid, montanic acid, oleic acid, linoleic acid, arachidonic acid, and salts of fatty acids with metals such as zinc, iron, magnesium, aluminum, calcium, sodium, lithium, etc.

[0142] Among them, alkoxysilanes, silazanes, and silicone oils are preferably used because they can be easily hydrophobized. These hydrophobizing agents can be used alone or in combination of two or more.

[0143] The amount of the external additive is preferably 0.05 parts by mass to 10.0 parts by mass relative to 100 parts by mass of the toner particles.

[0144] The production method of the toner is shown below.

[0145] A known method such as a pulverization method or a polymerization method can be used to produce the toner. Examples of suitable methods include dispersion polymerization method, association aggregation method, dissolution suspension method, suspension polymerization method, emulsion aggregation method and the like.

[0146] The suspension polymerization method is more preferable because the inorganic particles C are likely to be present near the surface of the toner particles, and a toner satisfying appropriate physical properties can be easily obtained.

[0147] A preferred embodiment in the case where the toner is produced by a suspension polymerization method is described below.

[0148] In the suspension polymerization method, for example, a polymerizable monomer capable of producing a binder resin, a hydrocarbon wax A, and an ester wax B, as well as inorganic particles C, a colorant, a polymerization initiator, a crosslinking agent, a charge control agent, and other additives as needed, are uniformly dispersed to obtain a polymerizable monomer composition. The resulting polymerizable monomer composition is then dispersed and granulated in a continuous layer (e.g., an aqueous phase) containing a dispersion stabilizer using an appropriate stirrer, and a polymerization reaction is carried out using a polymerization initiator to obtain toner particles having a desired particle size.

[0149] Examples of the polymerizable monomer include the following.

[0150] Styrene monomers, such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene, p-ethylstyrene, etc.

[0151] Acrylates, such as methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, behenyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, etc.

[0152] Methacrylates, such as methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, behenyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc.

[0153] Other monomers such as acrylonitrile, methacrylonitrile, acrylamide, etc. These monomers can be used alone or in mixture.

[0154] Among the above monomers, styrene-based monomers are preferred, either alone or in combination with other monomers such as acrylates and methacrylates, because the toner structure is controlled and the toner's development characteristics and durability are easily improved. In particular, it is more preferred to use styrene and acrylates or styrene and methacrylates as the main components. That is, the binder resin preferably includes 50% by mass or more of a styrene acrylic resin.

[0155] A polymer including styrene and at least one monomer selected from the group consisting of acrylates and methacrylates is preferable.

[0156] As polymerization initiators used to produce toner particles by suspension polymerization, those with a half-life of 0.5 to 30 hours during the polymerization reaction are preferred. Furthermore, it is preferred to use the polymerization initiator in an amount of 0.5 to 20 parts by mass per 100 parts by mass of the polymerizable monomer. As a result, a polymer with a maximum molecular weight between 5,000 and 50,000 can be obtained, and the toner can be provided with preferred strength and suitable melting properties.

[0157] Specific examples of the polymerization initiator include: azo or diazo polymerization initiators, such as 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobisisobutyronitrile, and peroxide polymerization initiators, such as benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxypivalate, di(2-ethylhexyl) peroxydicarbonate, di(sec-butyl) peroxydicarbonate, etc. Among them, tert-butyl peroxypivalate is preferred.

[0158] When the toner is produced by a polymerization method, a crosslinking agent may be added. Examples of the crosslinking agent include the following.

[0159] Divinylbenzene, 1,6-hexanediol diacrylate, polyethylene glycol #200 diacrylate (A200), polyethylene glycol #400 diacrylate (A400), polyethylene glycol #600 diacrylate (A600), polyethylene glycol #1000 diacrylate (A1000);

[0160] Dipropylene glycol diacrylate (APG100), tripropylene glycol diacrylate (APG200), polypropylene glycol #400 diacrylate (APG400), polypropylene glycol #700 diacrylate (APG700), polytetrapropylene glycol #650 diacrylate (A-PTMG-65).

[0161] The addition amount is preferably 0.05 to 15.0 parts by mass, more preferably 0.10 to 10.0 parts by mass, and even more preferably 0.20 to 5.0 parts by mass, relative to 100 parts by mass of the polymerizable monomer.

[0162] The polymerizable monomer composition may include a polar resin.

[0163] Examples of polar resins include: homopolymers of styrene and its substitution products, for example, polystyrene, polyvinyltoluene, etc.; styrene copolymers, for example, styrene-propylene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, styrene-methyl acrylate copolymers, styrene-ethyl acrylate copolymers, styrene-butyl acrylate copolymers, styrene-octyl acrylate copolymers, styrene-dimethylaminoethyl acrylate copolymers, styrene-methyl methacrylate copolymers, styrene-ethyl methacrylate copolymers, styrene-butyl methacrylate copolymers, styrene-dimethylaminoethyl methacrylate copolymers; ethyl ester copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-maleic acid copolymer, styrene-maleic ester copolymer, etc.; polymethyl methacrylate, polybutyl methacrylate, polyvinyl acetate, polyethylene, polypropylene, polyvinyl butyral, silicone resin, polyester resin, styrene-polyester copolymer, polyacrylate-polyester copolymer, polymethacrylate-polyester copolymer, polyamide resin, epoxy resin, polyacrylic resin, terpene resin, phenolic resin, etc.

[0164] These can be used alone or in mixtures of two or more. Further, functional groups such as amino, carboxyl, hydroxyl, sulfonic acid, glycidyl, nitrile, etc. can be introduced into these polymers. Among these resins, polyester resins are preferred.

[0165] As the polyester resin, a saturated polyester resin, an unsaturated polyester resin, or both may be appropriately selected and used.

[0166] As the polyester resin, a general polyester resin composed of an alcohol component and an acid component can be used, and the two components are explained below.

[0167] Examples of the diol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-hexanediol, cyclohexanedimethanol, butene glycol, octenediol, cyclohexenedimethanol, hydrogenated bisphenol A, or a bisphenol derivative represented by the following formula (A); a hydrogenated product of the compound represented by formula (A), a diol represented by the following formula (B), and a diol of a hydrogenated product of the compound represented by formula (B).

[0168]

[0169] In formula (A), R is an ethylene group or a propylene group, x and y are each an integer of 1 or greater, and the average value of x+y is 2-10.

[0170]

[0171] In formula (B), R' represents x' and y' are each an integer greater than or equal to 0; and the average value of x'+y' is 0-10.

[0172] As the diol component, the alkylene oxide adduct of the above bisphenol A has excellent charging characteristics and environmental stability and is well balanced in other electrophotographic characteristics, and is particularly preferred.

[0173] In the case of this compound, the average number of added moles of the alkylene oxide is preferably 2 to 10 in view of fixability and toner durability.

[0174] Examples of dibasic acid components include benzene dicarboxylic acids or their anhydrides such as phthalic acid, terephthalic acid, isophthalic acid, phthalic anhydride; alkyl dicarboxylic acids or their anhydrides such as succinic acid, adipic acid, sebacic acid, azelaic acid; succinic acid or its anhydride substituted with an alkyl or alkenyl group having 6 to 18 carbon atoms; unsaturated dicarboxylic acids or their anhydrides such as fumaric acid, maleic acid, citraconic acid, itaconic acid.

[0175] Further, examples of trivalent or higher alcohol components include glycerin, pentaerythritol, sorbitol, sorbitan, and oxyalkylene ethers of novolac-type phenolic resins, and examples of trivalent or higher acid components include trimellitic acid and pyromellitic acid, 1,2,3,4-butanetetracarboxylic acid, benzophenonetetracarboxylic acid and its anhydride, and the like.

[0176] Assuming that the total of the alcohol component and the acid component is 100 mol%, the polyester resin preferably includes 45 mol% to 55 mol% of the alcohol component.

[0177] The polyester resin can be produced using any catalyst such as a tin-based catalyst, an antimony-based catalyst, or a titanium-based catalyst, but a titanium-based catalyst is preferably used.

[0178] Furthermore, from the viewpoints of developing performance, blocking resistance, and durability, it is preferred that the number average molecular weight of the polar resin is 2,500 to 25,000.

[0179] The acid value of the polar resin is preferably 1.0 mg KOH / g to 15.0 mg KOH / g, and more preferably 2.0 mg KOH / g to 10.0 mg KOH / g.

[0180] The amount of the polar resin is preferably 2 parts by mass to 20 parts by mass relative to 100 parts by mass of the binder resin.

[0181] A dispersion stabilizer may be included in the aqueous medium in which the polymerizable monomer composition is dispersed.

[0182] As the dispersion stabilizer, known surfactants, organic dispersants, and inorganic dispersants can be used. Among them, inorganic dispersants can be preferably used because they ensure dispersion stability due to their steric hindrance, so that stability is not easily lost even when the reaction temperature is changed, are easy to wash, and do not adversely affect the toner.

[0183] Examples of these inorganic dispersants include: polyvalent metal salts of phosphoric acid such as tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, hydroxyapatite, etc.; carbonates such as calcium carbonate, magnesium carbonate, etc.; inorganic salts such as calcium metasilicate, calcium sulfate, barium sulfate, etc.; and inorganic compounds such as calcium hydroxide, magnesium hydroxide, aluminum hydroxide, etc.

[0184] The amount of the inorganic dispersant added is preferably 0.2 to 20 parts by mass relative to 100 parts by mass of the polymerizable monomer. Furthermore, a dispersion stabilizer may be used alone or in combination of two or more. Furthermore, a surfactant may be used in an amount of 0.001 to 0.1 parts by mass.

[0185] When an inorganic dispersant is used, it may be used as it is, but in order to obtain finer particles, fine particles of the inorganic dispersant may be generated in an aqueous medium and used.

[0186] For example, in the case of tricalcium phosphate, an aqueous sodium phosphate solution and an aqueous calcium chloride solution may be mixed under high-speed stirring to produce fine particles of water-insoluble calcium phosphate, thereby ensuring a more uniform and fine dispersion.

[0187] Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, sodium stearate, potassium stearate and the like.

[0188] In the step of polymerizing the polymerizable monomer, the polymerization temperature is generally set to 40° C. or higher, and preferably 50° C. to 90° C. When polymerization is performed within this temperature range, for example, a release agent or the like precipitates by phase separation to achieve more complete encapsulation.

[0189] After that, there is a cooling step of cooling from a reaction temperature of approximately 50° C. to 90° C. to end the polymerization step. At that time, gradual cooling may be performed to maintain a compatible state of the release agent and the binder resin.

[0190] After the polymerization of the polymerizable monomer is complete, the resulting polymer particles are filtered, washed, and dried using known methods to obtain toner particles. The toner particles can be used as a toner as is. Toner can be obtained by mixing an external additive with the toner particles and attaching the external additive to the surface of the toner particles. A classification step can also be added to the production process to separate coarse powder from fine powder contained in the toner particles.

[0191] Methods of measuring various physical properties of the toner will be described below.

[0192] Measurement method of I(ini) and I(10min) by heating IR

[0193] A pressure of 15 kN is applied to 300 mg of the toner by a Newton press for 1 minute to prepare toner pellets having a diameter of 1 cm.

[0194] Using toner pellets as a sample, heating IR measurement was performed under the following conditions.

[0195] Instrument: FT-IR, PerkinElmer Co., Frontier

[0196] Heating unit: Specac Ltd., MKII Golden Gate Single Reflection ATR System

[0197] Heating program: Increase the temperature from room temperature to 40 °C, hold at 40 °C for 1 minute, increase the temperature at 10 °C / min to 100 °C, hold at 100 °C for 10 minutes

[0198] IR spectrum acquisition conditions: resolution 4cm -1 , measuring range 4000-550cm -1 , points 5

[0199] Spectrum acquisition interval: 30 seconds

[0200] From the obtained IR spectrum, the peak at 2922 cm-1 assigned to hydrocarbon wax A was measured. -1The peak heights of hydrocarbon wax A and the peak attributable to the binder resin are calculated, and the peak height ratio I of hydrocarbon wax A to the binder resin is calculated. The position of the peak attributable to the binder resin can be selected according to the composition of the binder resin. The composition of the binder resin can be obtained by the "Composition Analysis of Binder Resin" described later.

[0201] For example, when the binder resin is a styrene acrylic resin, the peak derived from styrene at 696 cm -1 The height of the peaks of hydrocarbon wax A and the peak height ratio I of the binder resin was calculated. The I value at the time of reaching 100° C. was taken as I(ini), and the I value after holding at 100° C. for 10 minutes was taken as I(10 minutes). The arithmetic average of these samples was used.

[0202] SP value calculation method

[0203] The solubility parameter (SP value) was obtained using Fedors formula (2).

[0204] For the following values ​​of Δei and Δvi, refer to the evaporation energies and molar volumes (25° C.) of atoms and atomic groups shown in Table 3-9 of “Basic Science of Coating,” pp. 54-57, 1986 (Maki Shoten)”.

[0205] The unit of SP value is (cal / cm 3 ) 1 / 2 , but can be passed through 1(cal / cm 3 ) 1 / 2 =2.046×10 3 (J / m 3 ) 1 / 2 Convert to (J / m 3 ) 1 / 2 unit.

[0206] δi=(Ev / V) 1 / 2 =(Δei / Δvi) 1 / 2 Formula (2)

[0207] Ev: evaporation energy

[0208] V: molar volume

[0209] Δei: Evaporation energy of the atom or atomic group of component i

[0210] Δvi: molar volume of the atom or atomic group of component i

[0211] Molecular Weight Measurement of Ester Wax B by Mass Spectrometry

[0212] - Separation of wax from toner

[0213] Although the molecular weight of the wax can be measured using the toner as it is, it is more preferable to perform a separation operation.

[0214] The toner is dispersed in ethanol, a poor solvent for the toner, and the temperature is raised to a temperature exceeding the melting point of the wax. At this point, pressurization may be performed if necessary. By this operation, the wax exceeding the melting point is melted in ethanol and extracted. When heated and further pressurized, the wax can be separated from the toner by solid-liquid separation under pressurization. The extract is then dried and solidified to obtain the wax.

[0215] - Identification and molecular weight measurement of waxes by pyrolysis GCMS

[0216] Mass spectrometer: ISQ, manufactured by Thermo Fisher Scientific Co.

[0217] GC apparatus: Focus GC, manufactured by Thermo Fisher Scientific Co.

[0218] Ion source temperature: 250°C

[0219] Ionization method: EI

[0220] Mass range: 50-1000 m / z

[0221] Column: HP-5MS[30m]

[0222] Thermal cracking unit: JPS-700, manufactured by Japan Analytical Industry Co., Ltd.

[0223] A small amount of wax separated by the extraction procedure and 1 μL of tetramethylammonium hydroxide (TMAH) were added to a 590°C pyrofoil. The sample was subjected to pyrolysis GCMS under the above conditions to obtain peaks for the alcohol component and the carboxylic acid component derived from the ester compound. The alcohol component and the carboxylic acid component were detected as methylated products obtained by the action of the methylating agent TMAH.

[0224] The molecular weight can be obtained by analyzing the resulting peaks and identifying the structure of the ester wax.

[0225] Furthermore, hydrocarbon wax has a peak having a distribution derived from the decomposition pattern of hydrocarbons, and hydrocarbon wax can be identified by confirming and analyzing this peak.

[0226] - Identification and molecular weight measurement of waxes by direct incorporation

[0227] Mass spectrometer: ISQ, manufactured by Thermo Fisher Scientific Co.

[0228] Ion source temperature: 250°C; electron energy: 70eV

[0229] Mass range: 50-1000 m / z (CI)

[0230] Reagent gas: methane (CI)

[0231] Ionization method: Direct Exposure Probe (DEP), manufactured by Thermo Fisher Scientific Co.

[0232] 0mA (10 seconds) - 10mA / second - 1000mA (10 seconds)

[0233] The wax separated by the extraction operation is directly placed in the filament portion of the DEP unit for measurement. The molecular ion of the mass spectrum of the main component peak around 0.5 to 1 minute in the obtained chromatogram is confirmed, and the ester wax is identified to obtain the molecular weight.

[0234] Furthermore, since hydrocarbon wax has a characteristic mass spectrum with a distribution in increments of 14 m / z, confirmation can be performed using this mass spectrum.

[0235] - Identification and molecular weight measurement of ester waxes by MALDI-TOFMS

[0236] A total of 2 mg of the wax separated by the extraction procedure was accurately weighed and dissolved by adding 2 ml of chloroform to prepare a sample solution. Next, 20 mg of 2,5-dihydroxybenzoic acid (DHBA) was accurately weighed and dissolved by adding 1 ml of chloroform to prepare a matrix solution. Furthermore, 3 mg of NA trifluoroacetic acid (NATFA) was accurately weighed and dissolved by adding 1 ml of acetone to prepare an ionization aid solution.

[0237] A total of 25 μl of the sample solution, 50 μl of the matrix solution, and 5 μl of the ionization aid solution prepared in this manner were mixed, added dropwise to a MALDI analysis sample plate, and dried to obtain a measurement sample. The sample was measured under the following conditions to obtain a mass spectrum. The ester wax was identified from the obtained mass spectrum and its molecular weight was obtained.

[0238] Device: Flextreme, manufactured by Bruker Corp.

[0239] Conditions: Tof detection mode, Reflect mode

[0240] Measuring range: 100-2000 m / z

[0241] Laser intensity: 60%

[0242] Cumulative number: 3000

[0243] Composition analysis of binder resin

[0244] -Binder resin separation method

[0245] A total of 100 mg of the toner is dissolved in 3 ml of chloroform. Next, insoluble matter is removed by suction filtration using a syringe equipped with a sample processing filter (pore size 0.2 μm to 0.5 μm, for example, Myshori Disc H-25-2 (manufactured by Tosoh Corporation)).

[0246] The soluble fraction was introduced into a preparative HPLC (apparatus: LC-9130NEXT, preparative column [60 cm] exclusion limits: 20,000, 70,000, two-column; manufactured by Japan Analytical Industry Co., Ltd.), and the chloroform eluent was delivered. When a peak was confirmed on the resulting chromatogram, fractionation was performed at the retention time with a molecular weight of 2,000 or more, using a monodisperse polystyrene standard sample. The resulting fraction solution was dried and solidified to obtain a binder resin.

[0247] - Measurement of composition ratio and mass ratio by nuclear magnetic resonance spectroscopy (NMR)

[0248] A total of 1 mL of deuterated chloroform is added to 20 mg of the toner and the NMR spectrum of the protons of the dissolved binder resin is measured. The molar ratio and mass ratio of each monomer can be calculated from the obtained NMR spectrum, and the content of the monomer unit derived from styrene can be specified.

[0249] For example, in the case of a styrene acrylic copolymer, the composition ratio and the mass ratio can be calculated based on the peak derived from the styrene monomer at around 6.5 ppm and the peak derived from the acrylic monomer at around 3.5 to 4.0 ppm.

[0250] Further, for example, when a polyester resin generally known as a binder resin for toner is included, the molar ratio and mass ratio are calculated based on both the peak derived from each monomer constituting the polyester resin and the peak derived from the styrene acrylic copolymer to determine the amount of the monomer unit derived from styrene.

[0251] NMR equipment: JEOL RESONANCE ECX500

[0252] Observation nucleus: proton; Measurement mode: single pulse

[0253] Identification of inorganic particles C

[0254] Inorganic particles C are magnetic

[0255] A total of 10 ml of chloroform was added to 100 mg of the toner, and the homogenizer was operated for 10 minutes to dissolve the binder resin. Then, the magnetic body (inorganic particles C) was recovered by the magnet. The magnetic body was separated by repeating this operation several times.

[0256] The resulting magnetic material was subjected to thermal pyrolysis GCMS under the above conditions. Since the thermal pyrolysis products of the hydrophobizing agent can be obtained from the measurement results, the carbon number of the hydrophobizing agent can be determined from the main components. The thermal pyrolysis products are detected as alkyl substituents of the hydrophobizing agent, double bond modifications thereof, or alkylsilanes.

[0257] Inorganic particles C are not magnetic

[0258] A total of 1 ml of chloroform was added to 100 mg of the toner, and a homogenizer was operated for 10 minutes to dissolve and swell the binder resin. A total of 10 ml of chloroform was added thereto to reprecipitate the resin component and disperse the inorganic particles C in the supernatant. The supernatant was collected and dried to separate the inorganic particles C.

[0259] The resulting inorganic particles C were subjected to thermal cracking GCMS under the above conditions. Since the thermal cracking products of the hydrophobizing agent can be obtained from the measurement results, the carbon number of the hydrophobizing agent is obtained from the main components. The thermal cracking products are detected as alkyl substituents of the hydrophobizing agent, double bond modifications thereof, or alkylsilanes.

[0260] Example

[0261] Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited thereto. Unless otherwise specified, the "parts" used in Examples and Comparative Examples are based on mass.

[0262] Production Example of Ester Wax B1

[0263] A total of 100 parts of stearic acid and 10 parts of ethylene glycol were added to a reaction vessel equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, and a reaction was performed at 180° C. and atmospheric pressure under a nitrogen stream for 15 hours while distilling off reaction water.

[0264] The crude esterification product obtained by this reaction was washed with water by adding 20 parts of toluene and 4 parts of ethanol to 100 parts of the crude esterification product, stirring, and then standing for 30 minutes, and then removing the aqueous phase (lower layer) separated from the ester phase. The above water washing was repeated four times until the pH of the aqueous phase reached 7. Then, the solvent was distilled off from the washed ester phase under reduced pressure conditions of 170°C and 5 kPa to obtain ester wax B1.

[0265] Production Example of Ester Wax B2

[0266] Ester wax B2 was obtained by carrying out the same operation as in the production of ester wax B1, except that the acid monomer was changed from stearic acid to behenic acid.

[0267] Production Example of Ester Wax B3

[0268] Ester wax B3 was obtained by performing the same operation as in the production of ester wax B1, except that the alcohol monomer was changed from ethylene glycol to pentaerythritol.

[0269] Production Example of Ester Wax B4

[0270] Ester wax B4 was obtained by performing the same operation as in the production of ester wax B1, except that the alcohol monomer was changed from ethylene glycol to dipentaerythritol and the acid monomer was changed to lauric acid.

[0271] Production Example of Ester Wax B5

[0272] Ester wax B5 was obtained by carrying out the same operation as in the production of ester wax B1, except that the alcohol monomer was changed from ethylene glycol to dipentaerythritol.

[0273] Production Example of Ester Wax B6

[0274] Ester wax B6 was obtained by conducting the same operation as in the production of ester wax B1, except that the alcohol monomer was changed from ethylene glycol to behenyl alcohol and the acid monomer was changed to sebacic acid.

[0275] [Table 1]

[0276] Types of Ester Wax B composition Molecular weight SP value (SPb) Ester wax B1 Ethylene glycol distearate 595 8.85 Ester wax B2 Ethylene glycol dibehenate 707 8.81 Ester wax B3 Pentaerythritol tetrastearate 1202 8.93 Ester wax B4 Dipentaerythritol hexalaurate 1348 9.14 Ester wax B5 Dipentaerythritol hexastearate 1853 8.97 Ester wax B6 Dibehenyl Sebacate 819 8.77

[0277] The unit of SP value in the table is (cal / cm 3 ) 1 / 2 The same shall apply hereinafter.

[0278] Production Example of Inorganic Particles C1

[0279] A 1.0% equivalent of caustic soda solution relative to iron ions (including 1% by mass of sodium hexametaphosphate calculated as P relative to Fe) was mixed with an aqueous solution of ferrous sulfate to prepare an aqueous solution including ferrous hydroxide. While maintaining the aqueous solution at pH 9, air was blown into the aqueous solution, and an oxidation reaction was performed at 80°C to prepare a slurry for producing seed crystals.

[0280] Next, an aqueous solution of ferrous sulfate was added to the slurry to obtain an initial amount of 1.0 equivalent relative to the alkali (sodium component in caustic soda). The oxidation reaction was promoted while the slurry was maintained at pH 8 and air was blown in. At the end of the oxidation reaction, the pH was adjusted to 6, followed by washing and drying to obtain magnetic iron oxide in the form of spherical magnetite particles having a primary particle number average particle diameter of 200 nm.

[0281] A total of 10.0 kg of magnetic iron oxide was placed in a Simpson Mix-Muller (Model MSG-0L, manufactured by Shinto Kogyo Co., Ltd.) and pulverized for 30 minutes.

[0282] Thereafter, 95 g of n-decyltrimethoxysilane was added as a silane coupling agent in the same apparatus, and an operation was performed for 1 hour to hydrophobize the surfaces of the magnetic iron oxide particles with the silane coupling agent, thereby obtaining inorganic particles C1.

[0283] Production example of inorganic particles C2 to C6

[0284] Inorganic particles C2 to C6 were obtained in the same manner as in the production example of the inorganic particles C1, except that the kind of the hydrophobizing agent was changed as shown in Table 2.

[0285] Production example of inorganic particles C7

[0286] Inorganic particles C7 were obtained in the same manner as in the production example of inorganic particles C1, except that a Henschel mixer (Model FM-10, manufactured by Nippon Coke Industries Co., Ltd.) was used as the apparatus for pulverization and hydrophobization instead of the Simpson Mix-Muller, and an alkyl-modified silicone oil (dimethyl silicone and octylmethyl silicone copolymer) was used as the hydrophobization treatment agent instead of the alkylalkoxysilane.

[0287] Production example of inorganic particles C8

[0288] Inorganic particles C8 were obtained in the same manner as in the production example of inorganic particles C7, except that silica particles having a primary particle number average particle diameter of 100 nm were used as the inorganic particles to be hydrophobized instead of magnetic iron oxide.

[0289] [Table 2]

[0290]

[0291] In the table, the average primary particle size represents the number average particle size of the primary particles of the inorganic particles C.

[0292] Production example of polyester resin

[0293] -Terephthalic acid: 30.0 parts

[0294] -Trimellitate: 5.0 parts

[0295] -Bisphenol A ethylene oxide (2 mol) adduct: 160.0 parts

[0296] -Dibutyltin oxide: 0.1 parts

[0297] The above materials were placed in a heated and dried two-necked flask, nitrogen was introduced into the container to maintain an inert atmosphere, and the temperature was increased while stirring. Then, a polycondensation reaction was carried out while the temperature was increased from 140°C to 220°C over about 12 hours, and then a polycondensation reaction was carried out while reducing the pressure in the temperature range of 210°C to 240°C to obtain a polyester resin.

[0298] The polyester resin had a number average molecular weight (Mn) of 21,200, a weight average molecular weight (Mw) of 84,500, and a glass transition temperature (Tg) of 79.5°C.

[0299] Production of crystalline polyester 1

[0300] A total of 100.0 parts of sebacic acid (acid monomer 1) and 89.3 parts of 1,12-dodecanediol (alcohol monomer) were placed in a reaction vessel equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple. The temperature was raised to 140°C with stirring, and the mixture was heated at 140°C under a nitrogen atmosphere. The reaction was continued for 8 hours while distilling water at normal pressure.

[0301] Next, after adding 0.57 parts of tin dioctylate, the reaction was allowed to proceed while the temperature was raised to 200°C at a rate of 10°C / hour. After the temperature reached 200°C and the reaction was allowed to proceed for 2 hours, the pressure in the reaction vessel was reduced to 5 kPa or less, and the reaction was continued at 200°C while observing the molecular weight, thereby obtaining Crystalline Polyester 1. Analysis of the resulting Crystalline Polyester 1 revealed a weight-average molecular weight of 38,000.

[0302] Production Example of Toner Particles 1

[0303] After 450 parts of a 0.1 mol / L-Na3PO4 aqueous solution was added to 720 parts of ion-exchanged water and heated to a temperature of 60°C, 67.7 parts of a 1.0 mol / L-CaCl2 aqueous solution was added to obtain an aqueous medium including a dispersion stabilizer.

[0304] -Styrene: 75.0 parts

[0305] - n-Butyl acrylate: 25.0 parts

[0306] -1,6-Hexanediol diacrylate (HDDA): 1.0 part

[0307] -Polyester resin: 4.0 parts

[0308] -Inorganic particles C1: 65.0 parts

[0309] The above formulation was uniformly dispersed and mixed using an attritor (Nippon Cokes & Industry Co., Ltd.).

[0310] The obtained monomer composition was heated to a temperature of 60° C., and the following materials were mixed and dissolved therein, thereby preparing a polymerizable monomer composition.

[0311] - Hydrocarbon wax: 6.0 parts

[0312] (Fischer-Tropsch wax (HNP-51: manufactured by Nippon Seiro Co., Ltd.)

[0313] - Ester wax B1: 20.0 parts

[0314] -Polymerization initiator: 10.0 parts

[0315] (tert-Butyl peroxypivalate (25% toluene solution))

[0316] The polymerizable monomer composition was placed in an aqueous medium, stirred at 12,000 rpm for 15 minutes using a TK homomixer (Tokushu Kika Kogyo Co., Ltd.) at 60°C under a nitrogen atmosphere, and pelletized. The mixture was then stirred with a paddle stirrer and subjected to polymerization for 300 minutes at a reaction temperature of 70°C. After the reaction was complete, the suspension temperature was raised to 100°C and maintained for 2 hours.

[0317] Next, as a cooling step, 0°C water was added to the suspension, and the suspension was cooled to 30°C at a rate of 200°C / minute. The temperature was then raised and maintained at 55°C for 3 hours. The suspension was then cooled to 25°C by natural cooling at room temperature. The cooling rate at this time was 2°C / minute. Hydrochloric acid was then added to the suspension, and the suspension was thoroughly washed to dissolve the dispersion stabilizer, filtered, and dried to obtain Toner Particles 1.

[0318] The amount of styrene-derived monomer units in the binder resin in the resulting toner particles 1 was 72% by mass. The weight-average particle size (D4) of the resulting toner particles 1 was confirmed using a Coulter Counter Multisizer 3 (manufactured by Beckman Coulter Co., Ltd.) and was found to be 7.3 μm. The SP value (SPa) of the hydrocarbon wax HNP-51 was 8.37.

[0319] Production Example of Toner 1

[0320] A total of 0.3 parts of sol-gel silica fine particles having a primary particle number average particle size of 115 nm were added to 100 parts of toner particles 1 and mixed using an FM mixer (manufactured by Nippon Coke Industries Co., Ltd.). Then, silica fine particles having a primary particle number average particle size of 12 nm were treated with hexamethyldisilazane and then with silicone oil, and 0.9 parts of a sol-gel silica fine particle having a BET specific surface area value of 120 m was added. 2 / g of hydrophobic silica fine particles and mixed in the same manner using an FM mixer (manufactured by Nippon Coke Industries Co., Ltd.), thereby obtaining Toner 1. Tables 3 and 4 show the formulation and physical properties of the obtained Toner 1.

[0321] Production Examples of Toners 2 to 19 and Toners 25 to 32

[0322] Toners 2 to 19 and toners 25 to 32 were obtained in the same manner as in the production examples of Toner Particles 1 and Toner 1, except that the kinds and parts of the materials shown in Table 3 were changed. Tables 3 and 4 show the formulations and physical properties.

[0323] Production Example of Toner 21

[0324] After 450 parts of a 0.1 mol / L-Na3PO4 aqueous solution was added to 720 parts of ion-exchanged water and heated to a temperature of 60°C, 67.7 parts of a 1.0 mol / L-CaCl2 aqueous solution was added to obtain an aqueous medium including a dispersion stabilizer.

[0325] -Styrene: 75.0 parts

[0326] - n-Butyl acrylate: 25.0 parts

[0327] -1,6-Hexanediol diacrylate (HDDA): 1.0 part

[0328] The above formulation was uniformly dispersed and mixed using an attritor (Nippon Cokes & Industry Co., Ltd.).

[0329] The obtained monomer composition was heated to a temperature of 60° C., and the following materials were mixed and dissolved therein, thereby preparing a polymerizable monomer composition.

[0330] -Polymerization initiator: 10.0 parts

[0331] (tert-Butyl peroxypivalate (25% toluene solution))

[0332] The polymerizable monomer composition was placed in an aqueous medium, stirred at 12,000 rpm for 15 minutes using a TK homomixer (Tokushu Kika Kogyo Co., Ltd.) at 60°C in a nitrogen atmosphere, and pelletized. The mixture was then stirred with a paddle stirrer and subjected to polymerization reaction at a reaction temperature of 70°C for 300 minutes.

[0333] Then, the resulting suspension was cooled to room temperature at 3° C. / min, hydrochloric acid was added to dissolve the dispersion stabilizer, and the suspension was filtered, washed with water, and dried to obtain resin particles 1 .

[0334] - Resin pellets 1: 101.5 parts

[0335] -Inorganic particles C1: 65.0 parts

[0336] -Polyester resin: 4.0 parts

[0337] - Hydrocarbon wax: 6.0 parts

[0338] (Fischer-Tropsch wax (HNP-51: manufactured by Nippon Seiro Co., Ltd.)

[0339] - Ester wax B1: 20.0 parts

[0340] After premixing the above materials with an FM mixer (manufactured by Nippon Coke Industries Co., Ltd.), melt kneading was performed using a twin-screw extruder (trade name: PCM-30, manufactured by Ikegai Iron Works Co., Ltd.) and setting the temperature so that the melt temperature at the discharge port was 150°C.

[0341] The obtained kneaded product was cooled, coarsely pulverized with a hammer mill, and then finely pulverized using a pulverizer (trade name: Turbo Mill T250, manufactured by Turbo Industries, Ltd.).

[0342] The resulting finely pulverized product was classified using a multi-stage classifier utilizing the Coanda effect to obtain toner particles 21. The amount of styrene-derived monomer units in the binder resin in the resulting toner particles 21 was 73% by mass. The weight-average particle size (D4) of the resulting toner particles 21 was confirmed using a Coulter counter Multisizer 3 (manufactured by Beckman Coulter Co., Ltd.) and was found to be 7.3 μm. The SP value (SPa) of the hydrocarbon wax HNP-51 was 8.37.

[0343] Using the obtained toner particles 21, Toner 21 was obtained in the same manner as in the production method of Toner 1. Tables 3 and 4 show the formulation and various physical properties of Toner 21 obtained.

[0344] Production Example of Toner 22

[0345] -Bisphenol A ethylene oxide adduct (2.0 mol addition): 50.0 mol parts

[0346] -Bisphenol A propylene oxide adduct (2.3 mol addition): 50.0 mol parts

[0347] -Terephthalic acid: 60.0 parts by mole

[0348] -Trimellitic anhydride: 20.0 parts by mole

[0349] - Acrylic acid: 10.0 parts by mole

[0350] A total of 70 parts of the polyester monomer mixture was placed in a four-necked flask, which was equipped with a pressure reducing device, a water separator, a nitrogen inlet device, a temperature measuring device, and a stirring device, and stirred at 160° C. in a nitrogen atmosphere. A mixture of 30 parts of vinyl-based polymerizable monomers (90.0 parts by mole of styrene and 10.0 parts by mole of butyl acrylate) constituting the vinyl polymer segment and 2.0 parts by mole of benzoyl peroxide as a polymerization initiator was added dropwise from a dropping funnel over 4 hours.

[0351] Then, after reacting at 160°C for 5 hours, the temperature was raised to 20°C, 0.05 parts by mass of tetraisobutyl titanate was added, and the reaction time was adjusted to obtain the desired viscosity. After the reaction was completed, the reaction product was taken out of the container, cooled and pulverized to obtain a mixed resin.

[0352] -Mixed resin: 101.5 parts

[0353] -Inorganic particles C1: 65.0 parts

[0354] -Polyester resin: 4.0 parts

[0355] - Hydrocarbon wax: 6.0 parts

[0356] (Fischer-Tropsch wax (HNP-51: manufactured by Nippon Seiro Co., Ltd.)

[0357] - Ester wax B1: 20.0 parts

[0358] After premixing the above materials with an FM mixer (manufactured by Nippon Coke Industries Co., Ltd.), melt kneading was performed using a twin-screw extruder (trade name: PCM-30, manufactured by Ikegai Iron Works Co., Ltd.) and setting the temperature so that the melt temperature at the discharge port was 150°C.

[0359] The obtained kneaded product was cooled, coarsely pulverized with a hammer mill, and then finely pulverized using a pulverizer (trade name: Turbo Mill T250, manufactured by Turbo Industries, Ltd.).

[0360] The obtained finely pulverized product was classified using a multi-stage classifier utilizing the Coanda effect to obtain toner particles 22. The amount of monomer units derived from styrene in the binder resin in the obtained toner particles 22 was 26% by mass. The weight average particle diameter (D4) of the obtained toner particles 22 was confirmed by a Coulter counter Multisizer 3 (manufactured by Beckman Coulter Co., Ltd.) and found to be 7.2 μm.

[0361] Using the obtained toner particles 22, Toner 22 was obtained in the same manner as in the production method of Toner 1. Tables 3 and 4 show the formulation and various physical properties of the obtained Toner 22.

[0362] Production Examples of Toners 23, 33, and 34

[0363] Toners 23, 33, and 34 were obtained in the same manner as in the production example of toner 21, except that the kinds and parts of the materials shown in Table 3 were changed. Tables 3 and 4 show the formulations and physical properties.

[0364] Production Example of Toner 24

[0365] Toner particles 24 were obtained in the same manner as in the production example of toner particles 21, except that 5 parts of inorganic particles C8 and 5 parts of copper phthalocyanine were added as shown in Table 3. By using the obtained toner particles 24, toner 24 was obtained in the same manner as in the production example of toner 1. Tables 3 and 4 show the formulation and physical properties of the obtained toner 24.

[0366] Production Example of Toner 20

[0367] Toner 20 is produced by an emulsion aggregation method according to the following procedure.

[0368] Preparation of resin particle dispersion A

[0369] After 450 parts of a 0.1 mol / L-Na3PO4 aqueous solution was added to 720 parts of ion-exchanged water and heated to a temperature of 60°C, 67.7 parts of a 1.0 mol / L-CaCl2 aqueous solution was added to obtain an aqueous medium including a dispersion stabilizer.

[0370] -Styrene: 75.0 parts

[0371] - n-Butyl acrylate: 25.0 parts

[0372] -1,6-Hexanediol diacrylate (HDDA): 1.0 part

[0373] The above formulation was uniformly dispersed and mixed using an attritor (Nippon Cokes & Industry Co., Ltd.).

[0374] The obtained monomer composition was heated to a temperature of 60° C., and the following materials were mixed and dissolved therein, thereby preparing a polymerizable monomer composition.

[0375] -Polymerization initiator: 10.0 parts

[0376] (tert-Butyl peroxypivalate (25% toluene solution))

[0377] The polymerizable monomer composition was placed in an aqueous medium, stirred at 12,000 rpm for 15 minutes using a TK homomixer (Tokushu Kika Kogyo Co., Ltd.) at 60°C in a nitrogen atmosphere, and pelletized. The mixture was then stirred with a paddle stirrer and subjected to polymerization reaction at a reaction temperature of 70°C for 300 minutes.

[0378] Then, the resulting suspension was cooled to room temperature at 3° C. / min, hydrochloric acid was added to dissolve the dispersion stabilizer, and the suspension was filtered, washed with water, and dried to obtain resin particles 1 .

[0379] The following components were placed in a round bottom flask and stirred.

[0380] - Resin pellets 1: 100.0 parts

[0381] - Ethyl acetate: 60.0 parts

[0382] - Isopropyl alcohol: 15.0 parts

[0383] After confirming that the resin particles 1 were fully mixed, 3.0 parts of a 10% aqueous ammonia solution was added. Then, 1000 parts of ion-exchanged water was added dropwise, and a resin emulsion was obtained by phase transfer emulsification. Next, a resin particle dispersion A was obtained by removing the organic solvent (ethyl acetate, isopropyl alcohol) under reduced pressure using an evaporator. When the size of the resin particles in dispersion A was measured using a particle size measuring device (LA-700, manufactured by HORIBA, Ltd.), the average particle diameter was 0.15 μm.

[0384] Preparation of wax dispersion A

[0385] Place the following components into the designated containers.

[0386] - Hydrocarbon wax (HNP-51, manufactured by Nippon Seiro Co., Ltd.): 100.0 parts

[0387] - Anionic surfactant (Neogen RK, manufactured by DKS Co., Ltd.): 10.0 parts

[0388] - Ion exchange water: 390.0 parts

[0389] Next, the charged components were dispersed by using a homogenizer (Ultra-Turrax T50, manufactured by IKA Works, Inc.) while heating at 95° C., and then dispersed by a pressure discharge type homogenizer to prepare a wax dispersion A in which the wax component was dispersed. When measured using a particle size measuring device (LA-700, manufactured by HORIBA, Ltd.), the average particle diameter was 0.30 μm.

[0390] Preparation of wax dispersion B

[0391] Place the following components into the designated containers.

[0392] -Ester wax B1: 100.0 parts

[0393] - Anionic surfactant (Neogen RK, manufactured by DKS Co., Ltd.): 10.0 parts

[0394] - Ion exchange water: 390.0 parts

[0395] Next, the charged components were dispersed by using a homogenizer (Ultra-Turrax T50, manufactured by IKA Works, Inc.) while heating at 95° C., and then dispersed by a pressure discharge type homogenizer to prepare a wax dispersion B in which the wax component was dispersed. When measured using a particle size measuring device (LA-700, manufactured by HORIBA, Ltd.), the average particle diameter was 0.30 μm.

[0396] Preparation of magnetic dispersion

[0397] The magnetic body dispersion was obtained by dispersing the following components with a homogenizer (Ultra-Turrax T50, manufactured by IKA Works, Inc.) for 30 minutes.

[0398] -Inorganic particles C1: 100.0 parts

[0399] - Anionic surfactant (Neogen SC, manufactured by DKS Co., Ltd.): 10.0 parts

[0400] - Ion exchange water: 290.0 parts

[0401] Preparation of Toner Particles 20

[0402] The following components and ion-exchanged water were placed in such amounts as to ensure a solid content concentration of 15% in a separable flask equipped with a stirrer, a cooling tube, and a thermometer.

[0403] - Resin particle dispersion A: 100.0 parts, based on solid content

[0404] - Wax dispersion A: 6.0 parts, based on solid content

[0405] - Wax dispersion B: 20.0 parts, based on solid content

[0406] -Magnetic dispersion: 65.0 parts, based on solid content

[0407] Next, the contents of the flask were thoroughly mixed using a homogenizer (Ultra-Turrax T50, manufactured by IKA Works, Inc.). 0.36 parts of polyaluminum chloride was then gradually added as a flocculant, followed by dispersion using the homogenizer for 30 minutes. After 30 minutes, the contents were heated to 50°C, and 25.0 parts of Resin Particle Dispersion Liquid B was slowly added based on the solid content.

[0408] An appropriate amount of sodium hydroxide aqueous solution was then added to adjust the pH of the system to 6.9, followed by heating to 85° C. and maintaining the mixture for 3 hours while stirring. After cooling, the mixture was filtered, the solids were thoroughly washed with ion-exchanged water, and then dried and classified using a multi-classifier utilizing the Coanda effect to obtain toner particles 20.

[0409] The amount of monomer units derived from styrene in the binder resin in the obtained toner particles 20 was 73% by mass. The weight average particle diameter (D4) of the obtained toner particles 20 was confirmed by Coulter Counter Multisizer 3 (manufactured by Beckman Coulter Co., Ltd.) and found to be 7.1 μm.

[0410] Production of Toner 20

[0411] Using the obtained toner particles 20 , Toner 20 was obtained in the same manner as in the production example of Toner 1 .

[0412] Tables 3 and 4 show the formulation and various physical properties of the obtained toner 20.

[0413] [Table 3]

[0414]

[0415] In the table, “CE” stands for “Comparative Example”, “SP” stands for “suspension polymerization”, “EP” stands for “emulsion polymerization”, and “P” stands for “pulverization”.

[0416] [Table 4]

[0417]

[0418] In the tables, “CE” stands for “Comparative Example”.

[0419] An HP printer (Color LaserJet Enterprise M552) was modified by increasing the process speed by 1.5 times and setting the fixing nip pressure to 80% of the default setting, and used as an evaluation electrophotographic apparatus. Further, a CF230X was used as a toner cartridge, filled with 150 g of toner, and the following evaluation was performed.

[0420] A4 color laser copy paper (Canon Red Label 80g / m 2 ) is used as printing paper in the evaluation of low-temperature fixing. Because this paper is the thickest of the commonly used paper types, it can be used for detailed printing evaluation.

[0421] A4 color laser copy paper (Canon, 70g / m 2 ) was used as printing paper in the evaluation of output paper adhesion. Because this paper is relatively thin, heat is easily transferred to the toner layer. As a result, the toner melts easily and image adhesion is likely to occur, allowing evaluation under more stringent conditions. The evaluation results are shown in Table 5.

[0422] Belt peeling resistance (low temperature fixing), low temperature and low humidity environment

[0423] The tape peeling resistance was evaluated in a low-temperature, low-humidity environment (temperature 15° C., relative humidity 10%), which is a strict environment for evaluation of low-temperature fixability.

[0424] Specifically, the fixing temperature was changed in increments of 5° C., and at each temperature, an image was output in which 10 vertical lines of 4 dots were arranged at intervals of 5 mm with an upper margin of 250 mm and left and right margins of 80 mm.

[0425] Then, a polyester tape (No. 5515, manufactured by Nichiban Co., Ltd.) was attached to the portion of the image obtained under each temperature control having 10 vertical lines, and a load of 100 g was applied to the polyester tape three times back and forth so that the polyester tape image was in close contact with the image. Then, the temperature at which the number of lines that were broken and peeled off after peeling off the polyester tape was one or less was taken as the lower limit temperature for fixation, and it was determined that the lower the lower limit temperature for fixation, the better the fixability.

[0426] A. The lower limit of fixing temperature is less than 190°C.

[0427] B. The lower limit fixing temperature is 190°C or higher and lower than 200°C.

[0428] C. The lower limit fixing temperature is 200°C or higher and lower than 210°C.

[0429] D. The lower limit of fixing temperature is 210℃ or above.

[0430] Duplex printing mode, evaluation of output paper adhesion, duplex character printing images, toner-paper adhesion

[0431] The lower limit temperature obtained in the evaluation of the above low-temperature fixability was set as the fixing temperature, and 200 character images were continuously printed in duplex printing mode. The paper bundle discharged from the paper discharge section was left in a stacked state for more than 30 minutes and cooled to room temperature.

[0432] After that, for 50 sheets from the 76th to the 125th sheet of the paper bundle, the images on the front and back were checked one by one, and the image adhesion was evaluated by the number of blank dots. Here, the adhesion when the character image is continuously printed is an evaluation of the toner-paper adhesion.

[0433] When the sticking of the output paper can be suppressed, the number of blank spots in the character image is small. Meanwhile, when the sticking of the output paper cannot be suppressed, blank spots appear when sticking occurs in the paper bundle due to toner-paper adhesion, and the number of blank spots increases.

[0434] A. The number of blank spots is less than 5.

[0435] B. The number of blank spots is 5 or more and less than 20.

[0436] C. The number of blank spots is 20 or more and less than 40.

[0437] D. The number of blank spots is 40 or more.

[0438] Duplex printing mode, evaluation of output paper adhesion, double-sided solid print image, toner-toner adhesion

[0439] The lower limit temperature obtained in the evaluation of the above low-temperature fixability was set as the fixing temperature, and 200 solid images were continuously printed in duplex printing mode. The paper bundle discharged from the paper discharge section was left in a stacked state for more than 30 minutes and cooled to room temperature.

[0440] After that, for 50 sheets from the 76th to the 125th sheet of the paper bundle, the images on the front and back were checked one by one, and the image adhesion was evaluated by the number of blank dots. Here, the adhesion when the solid image is continuously printed is an evaluation of toner-toner adhesion.

[0441] When the sticking of output paper can be suppressed, the number of blank spots in the solid image is small. Meanwhile, when the sticking of output paper cannot be suppressed, blank spots appear when sticking occurs in the paper bundle due to toner-toner adhesion, and the number of blank spots increases.

[0442] A. The number of blank spots is less than 5.

[0443] B. The number of blank spots is 5 or more and less than 20.

[0444] C. The number of blank spots is 20 or more and less than 40.

[0445] D. The number of blank spots is 40 or more.

[0446] Evaluation of the adhesion of output paper in duplex printing mode after exposure to harsh conditions of high temperature and high humidity. Character printing images, toner-paper bonding

[0447] A total of 150 g of the toner was left in a high-temperature, high-humidity environment of 45° C. and 95% RH for 30 days. The toner was placed in a toner cartridge, and the output paper adhesion of the double-sided character printed image was evaluated in the same manner as in the above method.

[0448] [Table 5]

[0449]

[0450] In the table, “CE” stands for “Comparative Example”, “LLF” stands for “Lower Limit Fixing Temperature”, and “NB” stands for “Number of Blank Dots”.

[0451] While the present invention has been described with reference to exemplary embodiments, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. The scope of the following claims is to be accorded the broadest interpretation so as to encompass all such modifications and equivalent structures and functions.

Claims

1. A toner comprising toner particles, characterized in that: The toner particles comprise: Binder resin, Hydrocarbon wax A, Ester wax B, and Inorganic particles C hydrophobized with a hydrophobizing agent, wherein The binder resin includes a monomer unit represented by the following formula (St): The amount of the monomer unit represented by formula (St) in the binder resin is 50% by mass or more; The ester wax B is an ester compound of a diol having 2 to 6 carbon atoms and an aliphatic monocarboxylic acid having 16 to 22 carbon atoms; The hydrophobizing agent has an alkyl chain, and Assume that the SP value of the hydrocarbon wax A is SPa (cal / cm 3 ) 1 / 2 The SP value SPc (cal / cm 3 ) 1 / 2 The difference SPa-SPc between them is ΔSP1, and the SP value SPb (cal / cm 3 ) 1 / 2 The difference between SPb-SPa and the SP value SPa of the hydrocarbon wax A is ΔSP2, Then the ΔSP1 and the ΔSP2 satisfy the following equations (2) to (4): -0.60≤ΔSP1-ΔSP2≤0.10 (2) 0.41≤ΔSP2≤1.00(3), and 0.15≤ΔSP1≤0.55 (4); Assuming that, in a heating IR measurement in which the toner is kept at 100° C. for 10 minutes, the peak intensity ratio of the peak intensity attributable to the hydrocarbon wax A to the peak intensity attributable to the binder resin is I, the initial peak intensity ratio when heated to 100° C. is I(ini), and the peak intensity ratio when heated to 100° C. and kept for 10 minutes is I(10 minutes), Then the I(ini) and the I(10 minutes) satisfy the following equations (1) and (6): I(ini) / I(10 minutes)≤0.95 (1), 0.30≤I(10min)≤0.60 (6). 2 . The toner according to claim 1 , wherein the inorganic particles C are magnetic.

3. The toner according to claim 1, wherein The hydrophobizing agent has an alkyl chain, and Assume that the SP value of the ester wax B is SPb (cal / cm 3 ) 1 / 2 The SP value SPc (cal / cm 3 ) 1 / 2 The difference between SPb-SPc is ΔSP3, Then the ΔSP3 satisfies the following formula (5): ΔSP3≤1.05 (5). The toner according to claim 1 , wherein The hydrophobizing agent has an alkyl chain, and The SP value of the alkyl chain SPc (cal / cm 3 ) 1 / 2 It is 7.50 to 8.

50.

5. The toner according to claim 1, wherein the hydrophobizing agent comprises an alkyltrialkoxysilane coupling agent represented by the following formula (I): C p H 2p+1 -Si-(OC q H 2q+1 )3 (I) in, In formula (I), p represents an integer of 6 to 12, and q represents an integer of 1 to 3. 6 . The toner according to claim 1 , wherein the ester wax B has a molecular weight of 500 to 1000.

7. The toner according to any one of claims 1 to 5, wherein The toner particles contain the ester wax B in an amount of 5.0 to 35.0 parts by mass relative to 100.0 parts by mass of the binder resin in the toner particles. 8 . The toner according to claim 1 , wherein the toner particles contain the hydrocarbon wax A in an amount of 3.0 to 15.0 parts by mass relative to 100.0 parts by mass of the binder resin in the toner particles.

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