Toner resin particles, toner, developer, toner storage unit, image forming apparatus, toner manufacturing method, and image forming method.

Abstract

To provide a resin particle which is excellent in electrification characteristic, low-temperature fixability, hot-offset resistance, heat-resistant storage property and blocking resistance after fixation.SOLUTION: A resin particle according to one embodiment of the present invention contains at least a binder resin and a coloring agent. The resin particle contains a tetrahydrofuran insoluble content. The tetrahydrofuran insoluble content contains a non-linear polymer having cross-linking components branched into three or more pieces, a sulfur element and a metal element. A glass transition temperature of differential scanning calorimetry of the tetrahydrofuran insoluble content is -60°C or more and less than 0°C.SELECTED DRAWING: None

Description

[Technical Field]

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

[0002] Image forming devices such as multifunction printers (MFPs) and printers that utilize toner containing resin particles are widely used in various locations, including offices. Toner requires low-temperature fixing properties to improve the quality of output images and reduce power consumption during fixing, thereby saving energy.

[0003] As a toner designed to improve low-temperature fixation, for example, a toner has been proposed that includes toner particles obtained by surface-treating toner matrix particles, which are a mixture of toner matrix particles containing a predetermined binder resin, wax, and colorant, with predetermined boron nitride particles, using hot air (see, for example, Patent Document 1). [Overview of the project] [Problems that the invention aims to solve]

[0004] However, the toner described in Patent Document 1 does not address improvements in electrostatic properties and blocking resistance. A decrease in the electrostatic properties of the toner can lead to background staining and toner scattering. Furthermore, achieving excellent low-temperature fixing requires lowering the thermal properties of the binder resin that makes up the toner, making it difficult to achieve both low-temperature fixing and blocking resistance simultaneously.

[0005] One aspect of the present invention aims to provide resin particles that are excellent in electrostatic properties, low-temperature fixability, resistance to hot offset, heat-resistant storage, and resistance to blocking after fixation. [Means for solving the problem]

[0006] One aspect of the resin particles according to the present invention is resin particles containing at least a binder resin and a colorant, containing a tetrahydrofuran-insoluble component, the tetrahydrofuran-insoluble component including a non-linear polymer having a cross-linked component branched into three or more branches, sulfur element, and metal element, and the glass transition temperature Tg of the tetrahydrofuran-insoluble component measured by differential scanning calorimetry being not less than -60°C and less than 0°C.

Advantages of the Invention

[0007] According to one aspect of the present invention, it is possible to provide resin particles excellent in chargeability, low-temperature fixing property, hot offset resistance, heat storage resistance, and blocking resistance after fixing.

Brief Description of the Drawings

[0008] [Figure 1] It is a schematic configuration diagram showing an example of a process cartridge according to one embodiment. [Figure 2] It is a schematic configuration diagram showing an example of an image forming apparatus according to one embodiment. [Figure 3] It is a schematic configuration diagram showing another example of an image forming apparatus according to one embodiment. [Figure 4] It is a schematic configuration diagram showing another example of an image forming apparatus according to one embodiment. [Figure 5] It is a partially enlarged view of the image forming apparatus of FIG. 4.

Modes for Carrying Out the Invention

[0009] Hereinafter, embodiments of the present invention will be described in detail. The embodiments are not limited by the following description and can be appropriately changed without departing from the gist of the present invention. In addition, in this specification, "~" indicating a numerical range means including the numerical values described before and after it as the lower limit value and the upper limit value, unless otherwise specified.

[0010] <Resin Particles> The resin particles according to one embodiment contain at least a binder resin and a colorant. The resin particles according to one embodiment further contain tetrahydrofuran insoluble matter, the tetrahydrofuran insoluble matter comprising a nonlinear polymer having three or more branched crosslinking components, a sulfur element, and a metal element, and the differential scanning calorimetry glass transition temperature Tg of the tetrahydrofuran insoluble matter is -60°C or higher and less than 0°C.

[0011] The tetrahydrofuran insoluble component contains a nonlinear polymer having three or more branched crosslinked components, a sulfur element, and a metal element. By setting the glass transition temperature Tg of the tetrahydrofuran insoluble component to be between -60°C and 0°C, the crosslinked component can exhibit rubber-like properties, deforming at low temperatures but not flowing. Therefore, the resin particles according to one embodiment can achieve both excellent low-temperature fixability and blocking resistance after fixation, as well as excellent electrostatic properties, low-temperature fixability, hot offset resistance, and heat-resistant storage properties.

[0012] This embodiment describes the case where the resin particles are toner.

[0013] [Binding resin] The binder resin preferably contains an amorphous polyester resin and has a glass transition temperature (Tg) of 40°C to 70°C.

[0014] Amorphous polyester resin is preferred, and linear polyester resin is preferred.

[0015] As the amorphous polyester resin, an unmodified polyester resin is preferred. An unmodified polyester resin is a polyester resin obtained using a polyhydric alcohol and a polyhydric carboxylic acid such as a polyhydric carboxylic acid, polyhydric carboxylic acid anhydride, or polyhydric carboxylic acid ester, or a derivative thereof, and is a polyester resin that has not been modified with an isocyanate compound or the like.

[0016] Examples of polyhydric alcohols include diols.

[0017] Examples of diols include alkylene (2-3 carbon atoms) oxide (average number of added moles 1-10) adducts of bisphenol A such as polyoxypropylene(2,2)-2,2-bis(4-hydroxyphenyl)propane and polyoxyethylene(2,2)-2,2-bis(4-hydroxyphenyl)propane; ethylene glycol; propylene glycol; hydrogenated bisphenol A; and alkylene (2-3 carbon atoms) oxide (average number of added moles 1-10) adducts of hydrogenated bisphenol A. These may be used individually or in combination of two or more.

[0018] Examples of polycarboxylic acids include dicarboxylic acids.

[0019] Examples of dicarboxylic acids include adipic acid, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, maleic acid; and succinic acid substituted with C1-C20 alkyl groups or C2-C20 alkenyl groups, such as dodecenyl succinic acid and octyl succinic acid. These may be used individually or in combination of two or more.

[0020] Furthermore, for the purpose of adjusting the acid value and hydroxyl value, the binder resin may contain at least one of a trivalent or higher carboxylic acid and a trivalent or higher alcohol at the end of its resin chain.

[0021] Examples of trivalent or higher carboxylic acids include trimellitic acid, pyromellitic acid, or their acid anhydrides.

[0022] Examples of alcohols with a hydride of 3 or higher include glycerin, pentaerythritol, and trimethylolpropane.

[0023] There are no particular restrictions on the content of amorphous polyester resin in the binder resin, and it can be appropriately selected depending on the purpose, but 50 to 90 parts by mass and more preferably 70 to 85 parts by mass per 100 parts by mass of resin particles is preferred.

[0024] If the amorphous polyester resin content in the binder resin is 50 parts by mass or more, low-temperature fixing properties and hot offset resistance can be maintained. If the amorphous polyester resin content in the binder resin is 90 parts by mass or less, heat-resistant storage properties and the gloss and color of the image obtained after fixing can be maintained. If the amorphous polyester resin content in the binder resin is within the above more preferable range, the resin particles can exhibit even better low-temperature fixing properties, hot offset resistance, and heat-resistant storage properties.

[0025] There are no particular restrictions on the molecular weight of the binder resin, and it can be appropriately selected depending on the purpose. However, in gel permeation chromatography (GPC) measurements, the weight-average molecular weight Mw is preferably 3000 to 10000, and more preferably 4000 to 7000. The number-average molecular weight Mn is preferably 1000 to 4000, and more preferably 1500 to 3000. The Mw / Mn ratio is preferably 1.0 to 4.0, and more preferably 1.0 to 3.5.

[0026] The weight-average molecular weight (Mw) of the binder resin is between 3,000 and 10,000. This allows the resin particles to possess appropriate viscoelasticity during melting, resulting in superior low-temperature fixation and heat-resistant storage. Furthermore, the resin particles can withstand stresses such as agitation within a developing machine.

[0027] There are no particular restrictions on the acid value of the binder resin, and it can be appropriately selected depending on the purpose, but 1 mg KOH / g to 50 mg KOH / g is preferred, and 5 mg KOH / g to 30 mg KOH / g is more preferred.

[0028] If the acid value of the binder resin is 1 mg KOH / g or higher, the resin particles tend to become negatively charged, and furthermore, the affinity between the paper and the resin particles improves during fixation to paper, thereby improving low-temperature fixation performance. If the acid value of the binder resin is 50 mg KOH / g or lower, the decrease in electrostatic stability, especially in response to environmental changes, can be suppressed.

[0029] There are no particular restrictions on the hydroxyl value of the binder resin, and it can be appropriately selected depending on the purpose, but it is preferable that it is 5 mg KOH / g or higher.

[0030] The glass transition temperature (Tg) of the binder resin is preferably 40°C to 70°C, and more preferably 50°C to 60°C.

[0031] If the glass transition temperature (Tg) of the binder resin is 40°C or higher, the resin particles can exhibit superior heat resistance for storage. Furthermore, the resin particles can maintain durability against stresses such as agitation in a developing machine. Additionally, the resin particles can maintain filming resistance. If the glass transition temperature (Tg) of the binder resin is 70°C or lower, the resin particles can be sufficiently deformed by heating and pressurizing during fixing, allowing them to exhibit superior low-temperature fixing properties.

[0032] The molecular structure of the binder resin can be confirmed by NMR measurements in solution or solid form, as well as by X-ray diffraction, GC / MS, LC / MS, IR measurements, etc. A simple method is to use infrared absorption spectroscopy, specifically 965±10 cm⁻¹. -1 and 990±10cm -1 One method for detecting amorphous polyester resins is one in which those that do not exhibit absorption based on δCH (out-of-plane angular bending vibration) of olefins are identified.

[0033] There are no particular restrictions on the content of the binder resin, and it can be appropriately selected depending on the purpose, but 50 to 90 parts by mass and 60 to 80 parts by mass are preferred per 100 parts by mass of resin particles.

[0034] When the binder resin content is 50 parts by mass or more, the dispersibility of the pigment and release agent in the resin particles can be maintained, making it less likely for image blurring and distortion to occur. When the binder resin content is 90 parts by mass or less, the nonlinear polymer content can be sufficiently high, resulting in better low-temperature fixing properties. When the binder resin content is within the above-mentioned more preferable range, the resin particles can exhibit better low-temperature fixing properties and provide high-quality images.

[0035] The binder resin may contain a nonlinear polymer, and may also contain a crystalline resin together with the nonlinear polymer. In this specification, "nonlinear" means having a branched structure.

[0036] It is preferable that the crystalline resin melts near the fixing temperature. By incorporating such a crystalline resin into the resin particles, at the fixing temperature, the crystalline resin melts and becomes compatible with the binder resin, improving the sharp melt properties of the resin particles and exhibiting excellent low-temperature fixing properties.

[0037] As long as the crystalline resin is crystalline, there are no particular restrictions, and it can be appropriately selected according to the purpose. Examples include polyester resin, polyurethane resin, polyurea resin, polyamide resin, polyether resin, vinyl resin, and modified crystalline resin. These may be used individually or in combination of two or more.

[0038] There are no particular restrictions on the melting point of the crystalline resin, and it can be appropriately selected depending on the purpose, but 60°C to 100°C is preferred. If the melting point of the crystalline resin is 60°C or higher, the crystalline resin is less likely to melt at low temperatures, so the resin particles can exhibit better heat resistance for storage. If the melting point of the crystalline resin is 100°C or lower, the resin particles can exhibit better low-temperature fixation properties.

[0039] When the crystalline resin is a crystalline polyester resin, there are no particular restrictions on the content of the crystalline polyester resin, and it can be appropriately selected depending on the purpose. However, it is preferably 3 to 20 parts by mass, and more preferably 5 to 15 parts by mass, per 100 parts by mass of resin particles.

[0040] When the crystalline polyester resin content is 3 parts by mass or more, sufficient sharp melt formation by the crystalline polyester resin is obtained, allowing the resin particles to exhibit better low-temperature fixation properties. When the crystalline polyester resin content is 20 parts by mass or less, the resin particles exhibit better heat resistance and are less prone to image fogging.

[0041] When the content of crystalline polyester resin is within the aforementioned more preferable range, the resin particles can exhibit better low-temperature fixability and heat-resistant storage properties, and high-quality images can be provided.

[0042] [Tetrahydrofuran insoluble components] As described above, the tetrahydrofuran (THF) insoluble components include a nonlinear polymer having three or more branched crosslinking components, a sulfur element, and a metal element.

[0043] The crosslinking component may be formed by bonding a substituent containing at least a sulfur element to a metal ion. In other words, a nonlinear polymer may have a crosslinking component in which a substituent containing a sulfur element is metal-crosslinked to a metal ion. Examples of substituents containing a sulfur element include thiol groups, sulfanyl groups, hydroxyl groups, and sulfhydryl groups. Among these, sulfonic acid groups are preferred as substituents containing a sulfur element.

[0044] Nonlinear polymers are gel-like polymers with crosslinking components formed by metal crosslinking, and are therefore insoluble in THF. Thus, nonlinear polymers are included in the THF insoluble components. Note that the THF insoluble components do not contain polymers other than nonlinear polymers. The sulfur elements in the THF insoluble components originate from the sulfur elements in substituents containing sulfonic acid groups, which are components of the crosslinking components of nonlinear polymers. The metal elements in the THF insoluble components originate from the metal ions that are components of the crosslinking components of nonlinear polymers.

[0045] The crosslinking component may be formed by bonding at least a sulfonic acid group with a metal ion. In other words, the nonlinear polymer may have a crosslinking component in which a sulfonic acid group and a metal ion are metal-crosslinked.

[0046] The crosslinking components of nonlinear polymers are formed by the bonding of at least sulfonic acid groups and metal ions, resulting in a high degree of crosslinking and enhanced viscoelasticity. Consequently, the resin particles can exhibit superior low-temperature fixation, hot offset resistance, and blocking resistance.

[0047] The crosslinking component may be formed by bonding sulfonic acid groups and carboxylic acid groups with metal ions. In other words, the nonlinear polymer may have a crosslinking component in which sulfonic acid groups and carboxylic acid groups are metal-crosslinked with metal ions. Because the crosslinking component of the nonlinear polymer is formed by bonding sulfonic acid groups and carboxylic acid groups with metal ions, it is crosslinked to a high degree, increasing its viscoelasticity, and thus the resin particles can exhibit better low-temperature fixation, hot offset resistance, and blocking resistance.

[0048] As a means of obtaining the THF-insoluble portion of the resin particles according to one embodiment, there are methods such as dissolution filtration and a general Soxhlet extraction method to obtain the extraction residue, and any of these methods can be used without any problems.

[0049] For example, when using the dissolution filtration method, THF-insoluble components can be obtained as follows. First, weigh 1 g of resin particles and add them to 100 mL of THF. Stir with a stirring bar at 25°C for 6 hours to obtain a solution in which the soluble components of the resin particles have dissolved. Next, filter the obtained solution through a membrane filter with a mesh size of 0.2 μm, add the filtrate back into 50 mL of THF, and stir with a stirring bar for 10 minutes.

[0050] This process is repeated two or three times, and the resulting filtrate is dried in an environment of 120°C and 10kPa or less to obtain the THF-insoluble portion.

[0051] When using the Soxhlet extraction method, it is desirable to reflux 100 parts THF per part resin particle for at least 6 hours to separate the THF-insoluble and soluble components.

[0052] Since the THF-insoluble portion contains nonlinear polymers, the glass transition temperature (Tg) of the THF-insoluble portion can be said to be the glass transition temperature (Tg) of the nonlinear polymers. In other words, by measuring the glass transition temperature (Tg) of the THF-insoluble portion of resin particles, the glass transition temperature (Tg) of the nonlinear polymers can be confirmed.

[0053] As mentioned above, the differential scanning calorimetry (DSC) glass transition temperature Tg of THF-insoluble components is between -60°C and 0°C. That is, the DSC glass transition temperature Tg of nonlinear polymers is between -60°C and 0°C. The DSC glass transition temperature Tg of THF-insoluble components, or of nonlinear polymers, is preferably between -50°C and -10°C, and more preferably between -40°C and -20°C.

[0054] If the glass transition temperature (Tg) of the DSC of the THF-insoluble component, or the glass transition temperature (Tg) of the DSC of the nonlinear polymer, is between -60°C and 0°C, then excellent low-temperature fixability, heat resistance, and filming resistance can be achieved.

[0055] The glass transition temperature Tg of the DSC for THF-insoluble components or non-linear polymers is the glass transition temperature Tg of the DSC during the first heating cycle. 1st and the glass transition temperature Tg during the second heating cycle of DSC 2nd However, the glass transition temperature Tg during the second heating of the DSC 2nd That is preferable.

[0056] For nonlinear polymers, such as amorphous polyesters, the glass transition temperature Tg during the first heating step of the DSC is... 1st and the glass transition temperature Tg during the second heating cycle. 2ndIn any of these cases, there is no significant change in the value of the glass transition temperature Tg. However, since the glass transition temperature Tg of the non-linear polymer is generally measured by heating in the bulk state, when the glass transition temperature Tg in the first heating of the DSC 1st is considered, it is possible that air or the like is contained in the non-linear polymer and the noise increases.

[0057] When the glass transition temperature Tg of the DSC of the non-linear polymer is the glass transition temperature Tg in the second heating of the DSC 2nd because there is almost no air or the like in the non-linear polymer and the noise is small, it can be measured stably.

[0058] The non-linear polymer is obtained by the reaction of a non-linear reactive precursor and a metal ion. The cross-linked component of the non-linear polymer consists of a metal cross-link of a metal salt structure obtained by the reaction of a non-linear reactive precursor and a metal ion, and does not contain a urethane bond and a urea bond. Therefore, the resin particles can exhibit excellent charging properties.

[0059] (Non-linear reactive precursor) The non-linear reactive precursor (hereinafter sometimes referred to as a prepolymer) may be a polyester modified with a sulfonic acid. In other words, the prepolymer may be a polyester having a sulfonic acid group at its end. Since the prepolymer has a sulfonic acid group at its end, the sulfonic acid group is more likely to form a salt structure with a metal ion than a carboxylic acid group, so it can be cross-linked with a metal at a high degree of cross-linking, and the resin particles can exhibit excellent low-temperature fixing properties, hot offset resistance, and blocking resistance.

[0060] The prepolymer may have, in addition to the sulfonic acid group, other substituents capable of reacting with metal ions. There is no particular limitation on other substituents capable of reacting with metal ions, and they can be appropriately selected according to the purpose.

[0061] The prepolymer may have carboxylic acid groups in addition to sulfonic acid groups at its terminals. Because the nonlinear polymer has sulfonic acid groups and carboxylic acid groups at its terminals, the sulfonic acid groups and carboxylic acid groups form salt structures with metal ions. In particular, the sulfonic acid groups and metal ions can be crosslinked with a high degree of crosslinking, allowing the resin particles to exhibit excellent low-temperature fixation, hot offset resistance, and blocking resistance.

[0062] The prepolymer may have isocyanate groups in addition to sulfonic acid groups at its terminals. Because the nonlinear polymer has sulfonic acid groups and isocyanate groups at its terminals, the sulfonic acid groups and isocyanate groups form salt structures with metal ions. In particular, the sulfonic acid groups and metal ions can be crosslinked with a high degree of crosslinking, allowing the resin particles to exhibit excellent low-temperature fixation, hot offset resistance, and blocking resistance.

[0063] The prepolymer may be a polyester modified with a sulfonic acid, having a branched structure imparted by at least one of a trivalent or higher alcohol and a trivalent or higher carboxylic acid.

[0064] There are no particular restrictions on alcohols with a hydride of 3 or higher; they can be appropriately selected depending on the purpose. Examples include aliphatic alcohols with a hydride of 3 or higher, polyphenols with a hydride of 3 or higher, and alkylene oxide adducts of polyphenols with a hydride of 3 or higher.

[0065] Examples of trivalent or higher aliphatic alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol.

[0066] Examples of polyphenols with a trivalent or higher nucleotide

[0067] Examples of alkylene oxide adducts of polyphenols with a valency of 3 or higher include those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, or butylene oxide to polyphenols with a valency of 3 or higher.

[0068] There are no particular restrictions on the trivalent or higher carboxylic acid, and it can be appropriately selected depending on the purpose. Examples include trivalent or higher aromatic carboxylic acids. In addition, anhydrides of these compounds may be used, as well as lower (1-3 carbon atoms) alkyl esters or halides.

[0069] As for aromatic carboxylic acids with a valency of 9 to 20, those with a valency of 9 to 20 are preferred. Examples of aromatic carboxylic acids with a valency of 9 to 20 are trimellitic acid and pyromellitic acid.

[0070] Examples of sulfonic acids include aromatic sulfonic acids and aliphatic sulfonic acids.

[0071] Aromatic sulfonic acids include sodium dimethylisophthalic acid 5-sulfonate, p-toluenesulfonic acid, isotoluenesulfonic acid, metatoluenesulfonic acid, benzenesulfonic acid, p-xylene-2-sulfonic acid, naphthalene-1-sulfonic acid, naphthalene-2-sulfonic acid, aminobenzenesulfonic acid, 2-aminotoluene-5-sulfonic acid, 8-amino-2-naphthalenesulfonic acid, 4-biphenylsulfonic acid, benzene-1,3-sulfonic acid, p-toluenesulfonic acid-2-butynyl, and p-toluenesulfonic acid-3-butynyl Examples include chloroethyl p-toluenesulfonate, cyclohexyl p-toluenesulfonate, 2,5-dimethylbenzenesulfonic acid, dodecylbenzenesulfonic acid, ethyl benzenesulfonate, ethyl p-toluenesulfonate, ethylene glycol bis-p-toluenesulfonate, isobutyl p-toluenesulfonate, methyl benzenesulfonate, 1,3,6-naphthalenetrisulfonic acid, 1-naphthol-2-sulfonic acid, and salts (sodium salts, potassium salts, etc.), hydrates, and methyl ester compounds of these compounds.

[0072] Examples of aliphatic sulfonic acids include ethanesulfonic acid, 1,2-ethanedisulfonic acid, hydroxyamine-O-sulfonic acid, methanesulfonic acid, ethyl methanesulfonate, trifluoromethanesulfonic acid, 1-butanesulfonic acid, 1-decanesulfonic acid, 1-heptanesulfonic acid, 1-hexanesulfonic acid, 3-hydroxypropanesulfonic acid, 1-nonanesulfonic acid, 1-octanesulfonic acid, 1-pentanesulfonic acid, 1,3-propanedisulfonic acid, 1-dodecanesulfonic acid, 1-hexadecanesulfonic acid, 1-propanesulfonic acid, vinylsulfonic acid and its salts and hydrates.

[0073] Examples of prepolymers having isocyanate groups include polymers obtained by modifying the reaction product of a branched polyester having active hydrogen as a substituent with a diisocyanate using sulfonic acid, or polymers obtained by modifying the reaction product of a linear polyester without a branched structure having active hydrogen as a substituent with a trivalent or higher isocyanate using sulfonic acid.

[0074] As a branched polyester, the same polyesters as described above can be used. A linear polyester without a branched structure can be obtained by polycondensation of a diol and a dicarboxylic acid.

[0075] There are no particular restrictions on the diols, and they can be appropriately selected depending on the purpose. Examples include aliphatic diols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,8-octanediol, 1,10-decanediol, and 1,12-dodecanediol; diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, and polytetramethylene glycol. Examples include diols having an oxyalkylene group such as licol; alicyclic diols such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A; alicyclic diols to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide have been added; bisphenols such as bisphenol A, bisphenol F, and bisphenol S; and alkylene oxide adducts of bisphenols to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide have been added. Among these, aliphatic diols having 4 to 12 carbon atoms are preferred. These diols may be used individually or in combination of two or more.

[0076] There are no particular restrictions on the dicarboxylic acid, and it can be appropriately selected depending on the purpose. Examples include aliphatic dicarboxylic acids and aromatic dicarboxylic acids. In addition, anhydrides of these dicarboxylic acids may be used, as well as lower (1-3 carbon atoms) alkyl esters or halides.

[0077] There are no particular restrictions on the aliphatic dicarboxylic acid, and it can be appropriately selected depending on the purpose. Examples include succinic acid, adipic acid, sebacic acid, dodecanediic acid, maleic acid, and fumaric acid.

[0078] There are no particular restrictions on the aromatic dicarboxylic acid, and it can be appropriately selected depending on the purpose, but aromatic dicarboxylic acids having 8 to 20 carbon atoms are preferred.

[0079] There are no particular restrictions on the aromatic dicarboxylic acids having 8 to 20 carbon atoms, and they can be appropriately selected depending on the purpose. Examples include phthalic acid, isophthalic acid, terephthalic acid, naphthalenedicarboxylic acid, and the like.

[0080] Among aliphatic dicarboxylic acids and aromatic dicarboxylic acids, aliphatic dicarboxylic acids having 4 to 12 carbon atoms are preferred. These dicarboxylic acids may be used individually or in combination of two or more.

[0081] Examples of diisocyanates include aliphatic diisocyanates, alicyclic diisocyanates, aromatic diisocyanates, aromatic aliphatic diisocyanates, isocyanurates, and those obtained by blocking these with phenol derivatives, oximes, caprolactams, etc.

[0082] There are no particular restrictions on the aliphatic diisocyanates used, and they can be appropriately selected depending on the purpose. Examples include tetramethylene diisocyanate, hexamethylene diisocyanate, methyl 2,6-diisocyanatocaproate, octamethylene diisocyanate, decamethylene diisocyanate, dodecamethylene diisocyanate, tetradecamethylene diisocyanate, trimethylhexane diisocyanate, and tetramethylhexane diisocyanate.

[0083] There are no particular restrictions on the alicyclic diisocyanate, and it can be appropriately selected depending on the purpose. Examples include isophorone diisocyanate and cyclohexylmethane diisocyanate.

[0084] There are no particular restrictions on the aromatic diisocyanates, and they can be appropriately selected depending on the purpose. Examples include tolylene diisocyanate, diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, 4,4'-diisocyanatodiphenyl, 4,4'-diisocyanato-3,3'-dimethyldiphenyl, 4,4'-diisocyanato-3-methyldiphenylmethane, and 4,4'-diisocyanato-diphenyl ether.

[0085] There are no particular restrictions on the aromatic aliphatic diisocyanate, and it can be appropriately selected depending on the purpose. Examples include α,α,α',α'-tetramethylxylylene diisocyanate.

[0086] There are no particular restrictions on the isocyanates with a valency of 3 or higher, and they can be appropriately selected depending on the purpose. Examples include tris(isocyanatoalkyl)isocyanurate and tris(isocyanatocycloalkyl)isocyanurate.

[0087] These diisocyanates and isocyanates with a valentity of 3 or higher may be used individually or in combination of two or more.

[0088] As for the sulfonic acid, the same type as the sulfonic acid described above can be used.

[0089] Nonlinear polymers may also be obtained by reacting a prepolymer with metal ions and a curing agent.

[0090] (Hardening agent) The curing agent is not particularly limited as long as it reacts with the prepolymer and can be appropriately selected depending on the purpose. Examples include compounds containing active hydrogen groups.

[0091] There are no particular restrictions on the active hydrogen group in the active hydrogen group-containing compound, and it can be appropriately selected depending on the purpose. Examples include hydroxyl groups (alcoholic hydroxyl groups and phenolic hydroxyl groups), amino groups, carboxyl groups, mercapto groups, etc. These may be used individually or in combination of two or more.

[0092] There are no particular restrictions on the active hydrogen group-containing compound, and it can be appropriately selected depending on the purpose, but examples include amines.

[0093] There are no particular restrictions on the amines used, and they can be appropriately selected depending on the purpose. Examples include diamines, trivalent or higher amines, amino alcohols, amino mercaptans, amino acids, and those in which the amino group has been blocked. These may be used individually or in combination of two or more. Among these, diamines and mixtures of diamines and small amounts of trivalent or higher amines are preferred.

[0094] There are no particular restrictions on the diamines, and they can be appropriately selected depending on the purpose. Examples include aromatic diamines, alicyclic diamines, and aliphatic diamines. There are no particular restrictions on the aromatic diamines, and they can be appropriately selected depending on the purpose. Examples include phenylenediamine, diethyltoluenediamine, and 4,4'-diaminodiphenylmethane. There are no particular restrictions on the alicyclic diamines, and they can be appropriately selected depending on the purpose. Examples include 4,4'-diamino-3,3'-dimethyldicyclohexylmethane, diaminocyclohexane, and isophorone diamine. There are no particular restrictions on the aliphatic diamines, and they can be appropriately selected depending on the purpose. Examples include ethylenediamine, tetramethylenediamine, and hexamethylenediamine.

[0095] There are no particular restrictions on the amines with a valency of 3 or higher; they can be appropriately selected depending on the purpose. Examples include diethylenetriamine and triethylenetetramine.

[0096] There are no particular restrictions on the amino alcohol used; it can be appropriately selected depending on the purpose. Examples include ethanolamine and hydroxyethylaniline.

[0097] There are no particular restrictions on the amino mercaptan, and it can be appropriately selected depending on the purpose. Examples include aminoethyl mercaptan and aminopropyl mercaptan.

[0098] There are no particular restrictions on the amino acids used; they can be appropriately selected depending on the purpose. Examples include aminopropionic acid and aminocaproic acid.

[0099] There are no particular restrictions on the type of amino group that can be blocked, and they can be appropriately selected depending on the purpose. Examples include ketimine compounds and oxazoline compounds obtained by blocking the amino group with ketones such as acetone, methyl ethyl ketone, and methyl isobutyl ketone.

[0100] The molecular structure of polyester as a nonlinear polymer can be determined by NMR measurements in solution or solid state, as well as by X-ray diffraction, GC / MS, LC / MS, IR measurements, etc. A simple method is infrared absorption spectroscopy, which can determine the structure at 965±10 cm⁻¹. -1 and 990±10cm -1 One method involves detecting polyesters that do not exhibit absorption based on δCH (out-of-plane bending vibration) of olefins.

[0101] (Metal ions) As described above, metal ions function as crosslinking agents that crosslink the ends of nonlinear reactive precursors.

[0102] Examples of metal ions include divalent, trivalent, and tetravalent metal ions. Among these, it is preferable that the metal ions include divalent or higher valent metal ions. By including divalent or higher valent metal ions, the resin particles can exhibit superior low-temperature fixation, hot offset resistance, and blocking resistance.

[0103] Examples of divalent metal ions include magnesium ions, calcium ions, and strontium ions. Among these, strontium is preferred.

[0104] Examples of trivalent metal ions include aluminum ions, gallium ions, indium ions, and thallium ions. Among these, aluminum is preferred.

[0105] It is preferable that the metal ions include two or more types of metal ions with a valency of 2 or higher. By including two or more types of metal ions with a valency of 2 or higher, the resin particles can exhibit even better low-temperature fixation, hot offset resistance, and blocking resistance.

[0106] It is preferable that the two or more metal ions each have different valencies. When the two or more metal ions each have different valencies, the metal ion with the higher valency has higher reactivity with the substituent, resulting in a stronger crosslinking state and further excellent resistance to blocking and hot offset.

[0107] The difference in ionic diameter between two or more metal ions is preferably 50 pm or more, more preferably between 55 pm and 120 pm, and even more preferably between 60 pm and 65 pm. Note that a difference in ionic diameter between two or more metal ions of 50 pm or more means that for any two of the two or more metal ions selected, the difference in ionic diameter is 50 pm or more.

[0108] If the difference in ionic diameter of the metal ions is 50 pm or more, the reactivity of the crosslinking reaction increases, resulting in superior low-temperature fixation, hot offset resistance, and blocking resistance. In other words, as polyester is crosslinked, the distance between substituents that react with the metal ions increases, but if the metal ions have a large ionic radius, the metal ions and substituents react more easily, and crosslinking proceeds more smoothly.

[0109] On the other hand, as crosslinking increases the size of the reactants, steric hindrance also increases. However, if the metal ions have a small ionic radius, they can enter the gaps in the steric structure, making the crosslinking reaction proceed more easily.

[0110] Furthermore, as the reactivity of the crosslinking reaction increases, it also reacts with amorphous resins. Therefore, even when the resin particles contain amorphous polyester resin, they react with the amorphous polyester resin, thereby improving the low-temperature fixation and hot-off resistance of the resin particles according to one embodiment.

[0111] The presence or absence of sulfur and metal elements in nonlinear polymers can be qualitatively confirmed by analyzing the THF-insoluble components in the resin particles using X-ray fluorescence analysis. For example, qualitative analysis of metal elements can be performed using the ZSX PrimuIV X-ray fluorescence spectrometer (manufactured by Rigaku Corporation).

[0112] The form of the THF-insoluble sample to be measured is not particularly limited, but it is easier to handle if it is molded into pellets or sheets using a general-purpose pressure molder.

[0113] For example, a sample is placed in a 15mm diameter tablet forming die, and the die is placed in a high-temperature bath maintained above the glass transition temperature for about an hour. Immediately afterward, it is pressurized with a load of 6MPa for one minute to obtain THF-insoluble pellet tablets with a thickness of approximately 2mm. The obtained pellet tablets are placed in the sample holder of an X-ray fluorescence spectrometer, and qualitative analysis is performed to detect the metal elements contained in the sample.

[0114] There are no particular restrictions on the weight-average molecular weight of the nonlinear polymer, and it can be appropriately selected depending on the purpose, but in GPC measurement, 20,000 to 1,000,000 is preferred. The weight-average molecular weight of the nonlinear polymer is the molecular weight of the reaction product obtained by reacting a nonlinear reactive precursor with a metal ion.

[0115] If the weight-average molecular weight of the nonlinear polymer is 20,000 or higher, the resin particles will not flow even at low temperatures, exhibiting superior heat resistance and storage properties. Furthermore, the resin particles can maintain their viscosity during melting, resulting in superior hot offset properties.

[0116] The molecular structure of nonlinear polymers can be determined by NMR measurements in solution or solid state, as well as by X-ray diffraction, GC / MS, LC / MS, IR measurements, etc. For example, in infrared absorption spectroscopy, at 3100 cm⁻¹... -1 ~3500cm -1 One method for detecting sulfonic acid groups is by absorption based on [a specific method].

[0117] [Other ingredients] Other components include, for example, mold release agents, colorants, charge control agents, external additives, fluidity enhancers, cleaning properties enhancers, and magnetic materials.

[0118] (Release agent) There are no particular restrictions on the release agent, and it can be appropriately selected from known ones. Examples of release agents for waxes and waxes include plant-based waxes such as carnauba wax, cotton wax, wood wax, and rice wax; animal-based waxes such as beeswax and lanolin; mineral waxes such as ozokelite and selsine; and petroleum waxes such as paraffin, microcrystalline, and petrolatum; and other natural waxes.

[0119] In addition to these natural waxes, other examples include Fischer-Tropsch wax, synthetic hydrocarbon waxes such as polyethylene and polypropylene, and synthetic waxes such as esters, ketones, and ethers.

[0120] Furthermore, fatty acid amide compounds such as 12-hydroxystearic acid amide, stearic acid amide, phthalimide anhydride, and chlorinated hydrocarbons may be used; homopolymers or copolymers of polyacrylates such as poly-n-stearyl methacrylate and poly-n-lauryl methacrylate, which are low molecular weight crystalline polymer resins (for example, copolymers of n-stearyl acrylate and ethyl methacrylate); and crystalline polymers having long alkyl groups in their side chains may also be used.

[0121] Among the waxes exemplified above, hydrocarbon waxes such as paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyethylene wax, and polypropylene wax are preferred as release agents.

[0122] There are no particular restrictions on the melting point of the release agent, and it can be appropriately selected depending on the purpose, but 60°C to 80°C is preferred. If the melting point is 60°C or higher, the release agent will not melt easily at low temperatures, and its heat resistance can be maintained. If the melting point is 80°C or lower, even when the resin has melted and is in the fixing temperature range, the release agent will melt sufficiently, making fixing offset less likely and reducing the likelihood of image defects.

[0123] There are no particular restrictions on the content of the release agent, and it can be appropriately selected according to the purpose, but preferably 2 to 10 parts by mass, and more preferably 3 to 8 parts by mass, per 100 parts by mass of resin particles. When the content of the release agent is 2 parts by mass or more, better hot offset resistance and low-temperature fixing performance can be achieved. When the content of the release agent is 10 parts by mass or less, heat resistance for storage is improved and image fogging can be made less likely. When the content of the release agent is 3 to 8 parts by mass, it is advantageous in terms of improving image quality and fixing stability.

[0124] (Coloring agent) There are no particular restrictions on the colorants used; they can be appropriately selected depending on the purpose. For example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, ochre, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), tartrazine lake, quinoline yellow lake, and anthrazane yellow BGL. Isoindolone Yellow, Bengara, Red Lead, Red Lead, Cadmium Red, Cadmium Mercury Red, Antimony Red, Permanent Red 4R, Para Red, Faise Red, Parachlor-orthonitroaniline Red, Risol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, Permanent Red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belkan Fast Rubin B, Brilliant Scarlet G, Risol Rubin GX, Permanent Red F5R, Brillia Bon Maroon 6B, Pigment Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinon Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkali Blue Lake, Peacock Blue Lake, Victoria Blue Lake, Metal-free Phthalocyanine Blue, Phthalocyanine Blue, Fast Sky Blue, Indanthrene Blue (RS, BC), Indigo, Ultramarine, Prussian Blue, Anthraquinone Blue, Fast Violet B, Methyl Violet Lake, Cobalt Purple, Manganese Purple, Dioxane Violet, Anthraquinone Violet, Chrome Green, Zinc Green, Chromium Oxide, Pyridian, Emerald Green, Pigment Green B, Naphthol Green B, Green Gold, Acid Green Lake,Examples include malachite green lake, phthalocyanine green, anthraquinone green, titanium dioxide, zinc oxide, and lithobone.

[0125] There are no particular restrictions on the amount of colorant, and it can be appropriately selected depending on the purpose, but it is preferably 1 to 15 parts by mass, and more preferably 3 to 10 parts by mass, per 100 parts by mass of resin particles.

[0126] The colorant can also be used as a masterbatch compounded with the resin. Examples of resins used in the production of the masterbatch or kneaded together with the masterbatch include, in addition to amorphous polyester resins, polymers of styrene or its substituted derivatives such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene; styrene-p-chlorostyrene copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, and styrene-α-chloromethacrylate copolymer. Examples include styrene copolymers such as styrene-acrylonitrile copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, and styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, epoxy resin, epoxy polyol resin, polyurethane, polyamide, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, and paraffin wax. These may be used individually or in combination of two or more.

[0127] A masterbatch can be obtained by mixing and kneading a masterbatch resin and a colorant under high shear force. Organic solvents can be used during this process to enhance the interaction between the colorant and the resin.

[0128] Furthermore, a method known as the flushing method, in which an aqueous paste containing water from the coloring agent is mixed and kneaded with the resin and organic solvent to transfer the coloring agent to the resin side and remove the water and organic solvent components, is also preferred because it allows the wet cake of the coloring agent to be used as is, eliminating the need for drying. For mixing and kneading, a high-shear dispersion device such as a three-roll mill is preferably used.

[0129] (Static control agent) There are no particular restrictions on the charge control agent, and it can be appropriately selected depending on the purpose. Examples include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxyamines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, elemental or compound phosphorus, elemental or compound tungsten, fluorine-based surfactants, metal salicylic acid salts, and metal salts of salicylic acid derivatives. Specifically, examples include the nigrosine-based dye Bontron 03, the quaternary ammonium salt Bontron P-51, the metal-containing azo dye Bontron S-34, the oxynaphthoic acid-based metal complex E-82, the salicylic acid-based metal complex E-84, the phenolic condensate E-89 (all manufactured by Orient Chemical Industry Co., Ltd.), the quaternary ammonium salt molybdenum complexes TP-302 and TP-415 (both manufactured by Hodogaya Chemical Co., Ltd.), LRA-901, the boron complex LR-147 (manufactured by Nippon Carlit Co., Ltd.), copper phthalocyanine, perylene, quinacridone, azo pigments, and other polymer compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts.

[0130] There are no particular restrictions on the content of the charge control agent, and it can be appropriately selected depending on the purpose, but preferably 0.1 to 10 parts by mass, and more preferably 0.2 to 5 parts by mass, per 100 parts by mass of resin particles. When the content of the charge control agent is 10 parts by mass or less, the electrostatic charge of the resin particles does not become too large, and the effect of the charge control agent can be maintained. As a result, the electrostatic attraction force with the developing roller does not increase excessively, and a decrease in the fluidity of the developer and a decrease in image density can be suppressed.

[0131] These charge control agents can be dissolved and dispersed after melting and kneading with the masterbatch and resin, or they can be added directly to the organic solvent during dissolution and dispersion, or they can be immobilized on the surface of the resin particles after the resin particles have been formed.

[0132] (External additive) In addition to oxide nanoparticles, inorganic nanoparticles and hydrophobized inorganic nanoparticles can be used as external additives. Hydrophobized inorganic nanoparticles with an average primary particle size of 1 nm to 100 nm are preferred as external additives, and inorganic nanoparticles with an average primary particle size of 5 nm to 70 nm are more preferred.

[0133] Preferably, the external additive contains at least one type of hydrophobized inorganic fine particles with an average primary particle size of 20 nm or less, and at least one type of inorganic fine particles with an average primary particle size of 30 nm or more.

[0134] The specific surface area of ​​the external additive, calculated by the BET method, is 20 m². 2 / g~500m 2 / g is preferable.

[0135] There are no particular restrictions on external additives, and they can be appropriately selected depending on the purpose. Examples include silica nanoparticles, hydrophobic silica, fatty acid metal salts (e.g., zinc stearate, aluminum stearate, etc.), metal oxides (e.g., titania, alumina, tin oxide, antimony oxide, etc.), and fluoropolymers.

[0136] Suitable external additives include hydrophobized silica nanoparticles, hydrophobized titania nanoparticles, hydrophobized titanium oxide nanoparticles, and hydrophobized alumina nanoparticles.

[0137] Examples of hydrophobized silica nanoparticles include R972, R974, RX200, RY200, R202, R805, and R812 (all manufactured by Nippon Aerosil Co., Ltd.).

[0138] Examples of hydrophobized titania microparticles include P-25 (manufactured by Nippon Aerosil Co., Ltd.), STT-30, STT-65C-S (all manufactured by Titanium Industries Co., Ltd.), TAF-140 (manufactured by Fuji Titanium Industries Co., Ltd.), MT-150W, MT-500B, MT-600B, and MT-150A (all manufactured by Teika Co., Ltd.).

[0139] Examples of hydrophobized titanium oxide nanoparticles include T-805 (manufactured by Nippon Aerosil Co., Ltd.), STT-30A, STT-65S-S (all manufactured by Titanium Industry Co., Ltd.), TAF-500T, TAF-1500T (both manufactured by Fuji Titanium Industry Co., Ltd.), MT-100S, MT-100T (both manufactured by Teika Co., Ltd.), and IT-S (manufactured by Ishihara Sangyo Co., Ltd.).

[0140] Hydrophobized inorganic fine particles can be obtained, for example, by treating hydrophilic inorganic fine particles with a silane coupling agent such as methyltrimethoxysilane, methyltriethoxysilane, or octyltrimethoxysilane. Silicone oil-treated oxide fine particles and inorganic fine particles, obtained by treating inorganic fine particles with silicone oil and applying heat if necessary, are also suitable.

[0141] Examples of silicone oils include dimethyl silicone oil, methylphenyl silicone oil, chlorophenyl silicone oil, methylhydrogen silicone oil, alkyl-modified silicone oil, fluorine-modified silicone oil, polyether-modified silicone oil, alcohol-modified silicone oil, amino-modified silicone oil, epoxy-modified silicone oil, epoxy-polyether-modified silicone oil, phenol-modified silicone oil, carboxyl-modified silicone oil, mercapto-modified silicone oil, methacrylic-modified silicone oil, and α-methylstyrene-modified silicone oil.

[0142] Examples of inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, copper oxide, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, pengala, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, and silicon nitride. Among these, silica and titanium dioxide are particularly preferred.

[0143] There are no particular restrictions on the average particle size of the primary inorganic microparticles, and they can be appropriately selected depending on the purpose. However, a size of 100 nm or less is preferred, and a size of 3 nm to 70 nm is more preferred. Within this range, the inorganic microparticles are less likely to become embedded in the resin particles, allowing the functions of the inorganic microparticles to be effectively exhibited. Furthermore, uneven scratching of the photoreceptor surface can be suppressed.

[0144] There are no particular restrictions on the content of external additives, and they can be appropriately selected depending on the purpose, but preferably 0.1 to 5 parts by mass, and more preferably 0.3 to 3 parts by mass, per 100 parts by mass of resin particles.

[0145] (Flow improver) The fluidity improver is not particularly limited as long as it can be surface-treated to increase hydrophobicity and prevent deterioration of fluidity and electrostatic properties even under high humidity conditions; it can be appropriately selected according to the purpose.

[0146] Examples of fluidity improvers include silane coupling agents, silylation agents, silane coupling agents having alkyl fluoride compounds, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils. It is particularly preferable to surface-treat silica and titanium oxide with such fluidity improvers and use them as hydrophobic silica and hydrophobic titanium oxide.

[0147] (Cleaning performance enhancer) The cleaning agent is not particularly limited as long as it is added to the resin particles to remove residual developer after transfer from the photoreceptor or primary transfer medium, and can be appropriately selected according to the purpose. Examples include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, polymer fine particles produced by soap-free emulsion polymerization such as polymethyl methacrylate fine particles and polystyrene fine particles.

[0148] Polymer fine particles are preferably those with a relatively narrow particle size distribution, and those with a volume-average particle size of 0.01 μm to 1 μm are preferred.

[0149] (Magnetic material) There are no particular restrictions on the magnetic material, and it can be appropriately selected depending on the purpose. Examples include iron powder, magnetite, and ferrite. Among these, white materials are preferred in terms of color.

[0150] Glass transition temperature Tg of resin particles according to one embodiment during the first heating step of DSC 1st The temperature can be set to 20°C to 40°C.

[0151] Conventional toners generally have a relatively high glass transition temperature (Tg), exceeding 40°C. Therefore, temperature fluctuations during transportation and storage in high-temperature environments such as summer or tropical regions can easily cause toner aggregation. As a result, solidification in the toner bottle and toner adhesion within the developing machine are more likely to occur. Furthermore, toner clogging in the toner bottle can lead to poor replenishment, and toner adhesion within the developing machine can easily cause image abnormalities.

[0152] The resin particles according to one embodiment have a glass transition temperature Tg 1st The glass transition temperature (Tg) is 20°C to 40°C, and by including a nonlinear polymer, it has the function of lowering the glass transition temperature (Tg) compared to conventional toners while exhibiting excellent heat resistance for storage. The resin particles according to one embodiment have a glass transition temperature (Tg) 1st Having a glass transition temperature of 20°C or higher allows for superior heat resistance during storage and suppresses blocking and filming on the photoreceptor within the developing machine. The resin particles according to one embodiment have a glass transition temperature Tg 1st By keeping the temperature below 40°C, it can exhibit superior low-temperature fixation properties.

[0153] Glass transition temperature Tg of resin particles according to one embodiment 1st And the glass transition temperature Tg of the DSC at the second heating stage. 2nd The difference (Tg 1st -Tg 2nd There are no particular restrictions on the glass transition temperature (Tg), and it can be appropriately selected depending on the purpose, but it is preferably 10°C or higher. 1st and glass transition temperature Tg 2nd There is no particular upper limit to the difference between the two temperatures, and it can be appropriately selected depending on the purpose, but 50°C or less is preferable.

[0154] Resin particles have a glass transition temperature (Tg). 1st and glass transition temperature Tg 2nd If the difference between the temperature and the glass transition temperature (Tg) is 10°C or more, superior low-temperature fixing properties can be achieved. 1st and glass transition temperature Tg 2ndA temperature difference of 10°C or more means that, if the resin particles contain both crystalline and amorphous polyester resins, the crystalline and amorphous polyester resins, which were in a miscible state before heating (before the first heating cycle), become miscible after heating (after the first heating cycle). Note that the miscible state after heating does not need to be perfectly miscible.

[0155] The melting point of the resin particles according to one embodiment is not particularly limited and can be appropriately selected depending on the purpose, but 60°C to 80°C is preferred.

[0156] The THF-insoluble content of the resin particles according to one embodiment is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 15% to 35% by mass relative to the resin particles, and more preferably 20% to 30% by mass. If the THF-insoluble content is 15% by mass or more, better constant-temperature fixing properties can be exhibited, and if it is 35% by mass or less, better heat-resistant storage properties can be exhibited.

[0157] The THF-insoluble content in resin particles can be measured by weighing the amount of THF-insoluble content obtained from Soxhlet extraction of resin particles using an electronic balance, and can be calculated as (Amount of THF-insoluble content (g) / Amount of resin particles before extraction (g)) × 100.

[0158] There are no particular restrictions on the volume-average particle size of the resin particles, and they can be appropriately selected depending on the purpose, but 3 μm to 7 μm is preferred.

[0159] Furthermore, the ratio of volume-average particle size to number-average particle size is preferably 1.2 or less. It is also preferable that the mixture contains 1% to 10% of a component with a volume-average particle size of 2 μm or less.

[0160] <Methods for calculating and analyzing various properties of resin particles and resin particle components> The glass transition temperature (Tg), acid value, hydroxyl value, molecular weight, and melting point may be measured for each component individually, or they may be separated from the resin particles using GPC or the like, and the constituent monomer ratio, melting point, and glass transition temperature (Tg) of each separated component may be calculated using the analytical methods described later.

[0161] The separation of each component by GPC can be performed, for example, by the following method. (1) In GPC measurement using tetrahydrofuran (THF) as the mobile phase, the eluate is separated using a fraction collector or the like, and the fraction corresponding to the desired molecular weight portion of the total integral of the elution curve is collected. (2) After concentrating and drying the collected eluate using an evaporator or the like, the solids are dissolved in a deuterated solvent such as deuterated chloroform or deuterated THF. 1 1H-NMR measurements are performed, and the ratio of constituent monomers in the resin in the eluted components is calculated from the integral ratio of each element. (3) Another method involves concentrating the eluate, hydrolyzing it with sodium hydroxide or the like, and then qualitatively and quantitatively analyzing the decomposition products using high-performance liquid chromatography (HPLC) or the like to calculate the ratio of constituent monomers.

[0162] [Method for separating resin particle components] An example of a method for separating each component when analyzing resin particles according to one embodiment is described in detail. First, 1 g of resin particles is placed in 100 mL of THF and stirred at 25°C for 30 minutes to obtain a solution in which the soluble components have dissolved. Next, the solution is filtered through a membrane filter with a mesh size of 0.2 μm to obtain the THF-soluble components in the resin particles. Then, this is dissolved in THF to prepare a sample for GPC measurement and injected into the GPC used for molecular weight measurement of each resin as described above.

[0163] On the other hand, a fraction collector is placed at the eluate outlet of the GPC to separate the eluate at predetermined count intervals, and the eluate is obtained at intervals of 5% area percentage from the start of elution (the rising point of the curve) on the elution curve.

[0164] [Method for measuring melting point and glass transition temperature (Tg)] The melting point and glass transition temperature (Tg) of each separated component can be measured, for example, using a DSC system (Differential Scanning Calorimeter) ("Q-200", manufactured by TA Instruments). Specifically, the melting point and glass transition temperature of the target sample can be measured by the following procedure.

[0165] First, approximately 5.0 mg of the target sample is placed in an aluminum sample container, which is then placed on a holder unit and set in an electric furnace. Next, under a nitrogen atmosphere, the sample is heated from -80°C to 150°C at a heating rate of 10°C / min. After that, it is cooled from 150°C to -80°C at a cooling rate of 10°C / min, and then heated again to 150°C at a heating rate of 10°C / min (second heating).

[0166] During both the first and second heating cycles, a differential scanning calorimeter ("Q-200", manufactured by TA Instruments) is used to measure the DSC curve.

[0167] From the obtained DSC curves, the analysis program in the Q-200 system is used to select the DSC curve for the first heating cycle, and the glass transition temperature Tg of the target sample at the first heating cycle is determined. 1st Similarly, select the DSC curve during the second heating cycle and determine the glass transition temperature Tg of the target sample during the second heating cycle. 2nd We seek.

[0168] From the obtained DSC curves, the analysis program in the Q-200 system can be used to select the DSC curve for the first heating cycle, and the endothermic peak top temperature of the target sample during the first heating cycle can be determined as the melting point. Similarly, the DSC curve for the second heating cycle can be selected, and the endothermic peak top temperature of the target sample during the second heating cycle can be determined as the melting point.

[0169] In this specification, unless otherwise specified, the melting point and glass transition temperature Tg refer to the endothermic peak top temperature and glass transition temperature Tg during the second heating step. 2ndThese are defined as the melting point and glass transition temperature (Tg) of each sample.

[0170] <Toner> A toner according to one embodiment may contain resin particles according to one embodiment, or may consist of resin particles.

[0171] A toner according to one embodiment comprises resin particles according to one embodiment, and contains at least a binder resin and a colorant, and contains THF-insoluble matter, the THF-insoluble matter contains a nonlinear polymer having three or more branched crosslinking components, a sulfur element and a metal element, and the differential scanning calorimetry glass transition temperature Tg of the THF-insoluble matter is -60°C or higher and less than 0°C.

[0172] Nonlinear polymers have a very low glass transition temperature (Tg), and therefore deform at low temperatures. As a result, nonlinear polymers deform easily in response to heating and pressurization during fixing, making them more likely to come into contact with recording media such as paper at lower temperatures.

[0173] The crosslinking component of the nonlinear polymer is formed by metal crosslinking through the bonding of terminal substituents with metal ions. As a result, the toner according to one embodiment can exhibit excellent low-temperature fixation, hot offset resistance, and heat-resistant storage properties.

[0174] Furthermore, the nonlinear polymer is formed from a nonlinear reactive precursor, has a branched structure in its molecular backbone, and its molecular chains have a three-dimensional network structure. Therefore, the nonlinear polymer has rubber-like properties that do not flow even when deformed at low temperatures, and can increase the amount of charge it can hold. Thus, the toner according to one embodiment can exhibit excellent chargeability.

[0175] Furthermore, the toner according to one embodiment can reduce its adhesion to recording media such as paper and components within the developing machine by increasing its charge. Therefore, when the toner is fixed on the paper surface and stacked in the output tray, blocking occurs, where the toner adheres to the recording media due to the pressure from the weight of the recording media and the residual heat during fixing. In addition, the toner can be easily removed by the cleaning blade.

[0176] As described above, the toner according to one embodiment can exhibit excellent electrostatic properties, low-temperature fixing properties, high-temperature offset resistance, heat-resistant storage properties, and post-fixing blocking resistance.

[0177] The crosslinking component is formed by the bonding of at least a sulfonic acid group and a metal ion, and the metal ion may contain two types of divalent or higher metal ions. As a result, the crosslinking component makes contact with the recording medium more easily, and the toner according to one embodiment can exhibit better low-temperature fixation, hot offset resistance, and blocking resistance.

[0178] Furthermore, the metal ions can be two types of divalent or higher metal ions with different valencies. This allows for a greater charge resistance of the metal ions that crosslink at the ends of the crosslinking component, thus enabling the toner according to one embodiment to exhibit superior chargeability.

[0179] Furthermore, the difference in ionic diameter between two types of divalent or higher metal ions can be set to 50 pm or more. By setting the difference in ionic diameter between the two types of metal ions that crosslink at the ends of the crosslinking component to 50 pm or more, the network structure of the crosslinking component can be made into a more complex three-dimensional structure. Therefore, the toner according to one embodiment can exhibit superior low-temperature fixing properties, hot offset resistance, and blocking resistance.

[0180] <Toner manufacturing method> A toner manufacturing method according to one embodiment may include, for example, a granulation step of forming toner matrix particles and an external addition step of adding an external additive to the toner matrix particles.

[0181] [Granulation process] For example, methods such as dissolution suspension and emulsification agglutination can be used to form toner matrix particles.

[0182] In one embodiment of the toner manufacturing method, in the granulation step, an oil phase containing a nonlinear reactive precursor (prepolymer) may be mixed with an aqueous medium to form toner matrix particles while generating a nonlinear polymer through at least one of the extension reaction and crosslinking reaction between the reactive precursor and metal ions.

[0183] In a toner manufacturing method according to another embodiment, in the granulation step, the oil phase, in which a polyester resin and a nonlinear reactive precursor (prepolymer) are dissolved or dispersed in an organic solvent, is emulsified by phase inversion to remove the organic solvent, and then a dispersion containing a crystalline polyester resin is mixed to prepare a mixture, and the crystalline polyester resin in the mixture is agglomerated to form toner matrix particles.

[0184] Furthermore, in a toner manufacturing method according to another embodiment, in the granulation step, an oil phase containing a nonlinear reactive precursor (prepolymer) and an active hydrogen group-containing compound may be mixed with an aqueous medium to form toner matrix particles while generating a nonlinear polymer through at least one of the extension reaction and crosslinking reaction between the reactive precursor and metal ions.

[0185] The toner manufacturing methods according to each of the above embodiments include, in addition to a prepolymer, a crystalline polyester resin in the oil phase, and may further include a mold release agent, a colorant, etc., as needed.

[0186] The granulation process using the dissolution-suspension method will be described in detail below.

[0187] In a granulation process using a dissolution-suspension method, for example, a method can be used in which an oil phase containing a nonlinear reactive precursor is mixed with an aqueous medium, and toner matrix particles are formed while extending a nonlinear polymer by at least one of the reactions of extension and crosslinking between the reactive precursor and metal ions.

[0188] The granulation process using the dissolution suspension method includes a step of preparing an aqueous dispersion of crystalline polyester resin (crystalline polyester resin dispersion) (preparation of crystalline polyester resin dispersion), a step of preparing an aqueous medium (preparation of aqueous medium), a step of preparing an oil phase containing toner material (preparation of oil phase), a step of emulsifying or dispersing the toner material (emulsification or dispersion step), and a step of removing organic solvents (removal of organic solvents step).

[0189] (Preparation process of crystalline polyester resin dispersion) Crystalline polyester resin dispersions are preferably prepared by a phase inversion emulsification method. This method involves adding organic solvents, neutralizing agents, and surfactants to the resin as needed, adding an aqueous medium dropwise while stirring to obtain emulsion particles, and then removing the organic solvent from the resin dispersion to obtain an emulsion. Heating can also be performed as needed.

[0190] There are no particular restrictions on the organic solvent, and it can be appropriately selected depending on the purpose, but examples include methanol, ethanol, propanol, IPA, butanol, ethyl acetate, MEK, and combinations thereof. Organic solvents with a boiling point of less than 150°C are preferred because they are easy to remove.

[0191] As neutralizing agents, common acids and alkalis such as nitric acid, hydrochloric acid, sodium hydroxide, and ammonia can be used.

[0192] There are no particular restrictions on the method for removing organic solvents, and they can be appropriately selected depending on the purpose. For example, methods include gradually raising the temperature of the entire reaction system to evaporate the organic solvent in the oil droplets, or spraying the dispersion into a dry atmosphere to remove the organic solvent from the oil droplets.

[0193] One, two, or more types of surfactants may be used. The surfactants may be selected from ionic surfactants and nonionic surfactants. Here, ionic surfactants include anionic surfactants and cationic surfactants.

[0194] (Preparation process of aqueous media) The aqueous medium (aqueous phase) can be prepared, for example, by dispersing resin particles in the aqueous medium. There are no particular restrictions on the amount of resin particles added to the aqueous medium, and it can be appropriately selected depending on the purpose, but 0.5 to 10 parts by mass per 100 parts by mass of the aqueous medium is preferred.

[0195] There are no particular restrictions on the aqueous medium, and it can be appropriately selected depending on the purpose. Examples include water, a solvent miscible with water, and mixtures thereof. These may be used individually or in combination of two or more. Among these, water is preferred.

[0196] As a solvent miscible with water, it can be appropriately selected depending on the purpose, and examples include alcohols, lower ketones, dimethylformamide, tetrahydrofuran, cellosolves, etc. There are no particular restrictions on alcohols, and they can be appropriately selected depending on the purpose, and examples include methanol, isopropanol, ethylene glycol, etc. As a lower ketone, it can be appropriately selected depending on the purpose, and examples include acetone, methyl ethyl ketone, etc.

[0197] (Preparation process of the oil phase) The oil phase containing the toner material can be prepared by dissolving or dispersing the toner material, which includes at least a nonlinear reactive precursor, a binder resin (e.g., amorphous polyester resin, crystalline polyester resin, etc.), a colorant, and optionally a curing agent, a release agent, etc., in an organic solvent.

[0198] There are no particular restrictions on the organic solvent, and it can be appropriately selected depending on the purpose, but organic solvents with a boiling point of less than 150°C are preferred because they are easy to remove.

[0199] There are no particular restrictions on organic solvents with a boiling point below 150°C, and they can be appropriately selected depending on the purpose. Examples include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, methyl ethyl ketone, and methyl isobutyl ketone. These may be used individually or in combination of two or more.

[0200] Among these, ethyl acetate, toluene, xylene, benzene, methylene chloride, 1,2-dichloroethane, chloroform, carbon tetrachloride, etc. are preferred, with ethyl acetate being more preferred.

[0201] (Emulsification or dispersion process) The toner material can be emulsified or dispersed by dispersing an oil phase containing the toner material in an aqueous medium. Furthermore, during the emulsification or dispersion of the toner material, a nonlinear polymer is generated by performing at least one of an extension reaction and a crosslinking reaction between metal ions and a nonlinear reactive precursor.

[0202] Specifically, nonlinear polymers can be produced, for example, by the following methods (1) and (2). (1) An oil phase containing a nonlinear reactive precursor and metal ions is emulsified or dispersed in an aqueous medium, and a nonlinear polymer is produced by carrying out at least one of an extension reaction and a crosslinking reaction between the metal ions and the nonlinear reactive precursor in the aqueous medium. (2) An oil phase containing a nonlinear reactive precursor is emulsified or dispersed in an aqueous medium to which metal ions have been added in advance, and a nonlinear polymer is produced by carrying out at least one of an extension reaction and a crosslinking reaction between the metal ions and the nonlinear reactive precursor in the aqueous medium.

[0203] There are no particular restrictions on the reaction time, and it can be selected as appropriate depending on the purpose, but 10 minutes to 40 hours is preferred, and 2 hours to 24 hours is more preferred.

[0204] There are no particular restrictions on the reaction temperature, and it can be appropriately selected depending on the purpose, but 0°C to 150°C is preferred, and 40°C to 98°C is more preferred.

[0205] There are no particular limitations on the method for stably forming a dispersion containing a nonlinear reactive precursor in an aqueous medium, and a suitable method can be selected depending on the purpose. For example, one method involves adding an oil phase prepared by dissolving or dispersing toner material in a solvent to an aqueous medium phase and dispersing it by shear force.

[0206] There are no particular restrictions on the type of disperser used for dispersion, and they can be appropriately selected according to the purpose. Examples include low-speed shear dispersers, high-speed shear dispersers, friction dispersers, high-pressure jet dispersers, and ultrasonic dispersers.

[0207] Among these, a high-speed shear disperser is preferred because it can control the particle size of the dispersion (oil droplets) to between 2 μm and 20 μm. When using a high-speed shear disperser, conditions such as rotation speed, dispersion time, and dispersion temperature can be appropriately selected according to the purpose.

[0208] There are no particular restrictions on rotational speed, and it can be selected appropriately depending on the purpose, but 1,000 rpm to 30,000 rpm is preferred, and 5,000 rpm to 20,000 rpm is more preferred.

[0209] There are no particular restrictions on the distribution time, and it can be selected as appropriate depending on the purpose, but for batch processing, 0.1 to 5 minutes is preferable.

[0210] There are no particular restrictions on the dispersion temperature, and it can be appropriately selected depending on the purpose, but under pressure, 0°C to 150°C is preferred, and 40°C to 98°C is more preferred. Generally, dispersion is easier at higher dispersion temperatures.

[0211] There are no particular restrictions on the amount of aqueous medium used when emulsifying or dispersing toner material, and it can be appropriately selected according to the purpose. However, 50 to 2000 parts by mass of aqueous medium per 100 parts by mass of toner material is preferred, and 100 to 1000 parts by mass is more preferred. If the amount of aqueous medium used is 50 parts by mass or more, the toner material can be stably dispersed, and toner matrix particles of a predetermined particle size can be obtained. If the amount of aqueous medium used is 2000 parts by mass or less, production costs can be reduced.

[0212] When emulsifying or dispersing an oil phase containing toner material, it is preferable to use a dispersant from the viewpoint of stabilizing the dispersion, such as oil droplets, to achieve the desired shape and sharpen the particle size distribution.

[0213] There are no particular restrictions on the dispersant, and it can be appropriately selected depending on the purpose. Examples include surfactants, dispersants of poorly water-soluble inorganic compounds, and polymeric protective colloids. These may be used individually or in combination of two or more. Among these, surfactants are preferred.

[0214] There are no particular restrictions on the surfactant used; it can be appropriately selected depending on the purpose. For example, anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, etc., can be used.

[0215] There are no particular restrictions on the anionic surfactant, and it can be appropriately selected depending on the purpose. Examples include alkylbenzene sulfonates, α-olefin sulfonates, and phosphate esters. Among these, those having a fluoroalkyl group are preferred.

[0216] (Soluble solvent removal process) Toner matrix particles are obtained by removing the organic solvent from a dispersion such as an emulsified slurry. There are no particular restrictions on the method for removing the organic solvent from the dispersion, and it can be appropriately selected depending on the purpose. For example, methods include gradually raising the temperature of the entire reaction system to evaporate the organic solvent in the oil droplets, or spraying the dispersion into a dry atmosphere to remove the organic solvent in the oil droplets.

[0217] Once the organic solvent is removed, toner matrix particles are formed. These toner matrix particles can be washed, dried, and further classified. Classification may be performed by removing the fine particles in the liquid using a cyclone, decanter, centrifugation, etc., or the classification operation may be performed after drying.

[0218] [External addition process] Furthermore, external additives, charge control agents, etc., may be mixed with the obtained toner matrix particles. In this case, applying a mechanical impact force can suppress the detachment of particles such as external additives from the surface of the toner matrix particles.

[0219] The method for applying mechanical impact force can be appropriately selected depending on the purpose. Examples include applying impact force to a mixture using a high-speed rotating blade, or introducing a mixture into a high-speed airflow to accelerate it and causing particles to collide with each other or with a suitable impact plate.

[0220] The devices used to apply mechanical impact force can be appropriately selected depending on the purpose. Examples include the Ongmill (manufactured by Hosokawa Micron Corporation), a modified I-type mill (manufactured by Nippon Pneumatic Co., Ltd.) with reduced grinding air pressure, a hybridization system (manufactured by Nara Machine Works), a cryptron system (manufactured by Kawasaki Heavy Industries), and an automatic mortar and pestle.

[0221] Next, the toner according to one embodiment is obtained by passing it through a sieve of 250 mesh or larger to remove coarse particles and aggregated particles.

[0222] <Developer> A developer according to one embodiment includes a toner according to one embodiment and may optionally contain other components such as a carrier. As a result, the developer according to one embodiment can exhibit excellent electrostatic properties, low-temperature fixing properties, hot offset resistance, heat storage resistance, and post-fixing blocking resistance.

[0223] The developer may be a one-component developer or a two-component developer, but when used in high-speed printers and the like to accommodate the recent increase in information processing speed, a two-component developer is preferable from the standpoint of extending its lifespan.

[0224] When toner according to one embodiment is used in a one-component developer, even when toner is balanced, there is little variation in toner particle size, less toner filming onto the developing roller, and less toner fusion to components such as blades that thin the toner layer. As a result, good and stable developability and images can be obtained even with long-term agitation in the developing apparatus.

[0225] When the toner according to one embodiment is used in a two-component developer, it can be mixed with a carrier and used as a developer. When the developer is used as a two-component developer, even if the toner is balanced over a long period of time, the toner particle size does not fluctuate much, and good and stable developability and images can be obtained even with long-term agitation in the developing device.

[0226] The carrier content in the two-component developer can be appropriately selected depending on the purpose, but 90 to 98 parts by mass and more preferably 93 to 97 parts by mass per 100 parts by mass of the two-component developer is preferred.

[0227] The developer according to one embodiment can be suitably used for image formation by various known electrophotographic methods, such as magnetic one-component development methods, non-magnetic one-component development methods, and two-component development methods.

[0228] [Career] The carrier is not particularly limited and can be appropriately selected according to the purpose, but it is preferable that it has a core material and a resin layer (coating layer) that covers the core material.

[0229] (Core material) There are no particular restrictions on the core material, and it can be appropriately selected according to the purpose. Examples include manganese-strontium materials with a density of 50 emu / g to 90 emu / g, manganese-magnesium materials with a density of 50 emu / g to 90 emu / g, etc.

[0230] To ensure image density, it is preferable to use highly magnetized materials such as iron powder with a magnetite density of 100 emu / g or more, or magnetite with a magnetite density of 75 emu / g to 120 emu / g. Furthermore, from the viewpoint of mitigating the impact of the developer on the photoreceptor when it is in a condensed state, and being advantageous for high image quality, it is preferable to use a low magnetized material such as copper-zinc alloy with a magnetite density of 30 emu / g to 80 emu / g. These materials may be used individually or in combination of two or more.

[0231] The volume-average particle size of the core material is not particularly limited and can be appropriately selected depending on the purpose, but 10 μm to 150 μm is preferred, and 40 μm to 100 μm is more preferred.

[0232] If the volume-average particle size of the core material is 10 μm or larger, it is possible to effectively prevent the problem of carrier scattering due to a large amount of fine powder in the carrier, which reduces the magnetization per particle. On the other hand, if it is 150 μm or smaller, the specific surface area decreases, which can cause toner scattering, and in full-color printing with many solid areas, it is possible to effectively prevent the problem of poor reproduction of solid areas.

[0233] (Resin layer) The resin layer may contain a resin and, if necessary, other components. As the resin used in the resin layer, any known material capable of imparting the required electrostatic properties can be used. Specifically, silicone resin, acrylic resin, or a combination thereof is preferred. Furthermore, the composition for forming the resin layer preferably contains a silane coupling agent.

[0234] The average thickness of the resin layer is preferably 0.05 μm to 0.50 μm.

[0235] <Toner storage unit> A toner storage unit according to one embodiment can store toner according to one embodiment. A toner storage unit according to one embodiment refers to a unit having the function of storing toner, in which toner is stored. Here, examples of the form of the toner storage unit include a toner storage container, a developer, and a process cartridge.

[0236] A toner container refers to a container that holds toner.

[0237] A developing unit refers to a device that has the means to store toner and develop it.

[0238] A process cartridge is defined as a device that integrates at least an electrostatic latent image carrier (also called an image carrier) and a developing means, contains toner, and is detachable from an image forming apparatus. The process cartridge may further include at least one selected from a charging means, an exposure means, a cleaning means, etc.

[0239] A process cartridge according to one embodiment is molded to be detachable from various image forming apparatuses and includes an electrostatic latent image carrier that carries an electrostatic latent image, and a developing unit that develops the electrostatic latent image carried on the electrostatic latent image carrier with the developer according to the above embodiment to form a toner image, and may have other configurations as needed.

[0240] (Electrostatic latent image carrier) The material, shape, structure, size, etc., of the electrostatic latent image carrier (sometimes referred to as "electrophotographic photoreceptor" or "photoreceptor") are not particularly limited and can be appropriately selected from known materials. Examples of materials for the electrostatic latent image carrier include inorganic photoreceptors such as amorphous silicon and selenium, and organic photoreceptors (OPC) such as polysilane and phthalopolymethine. Among these, amorphous silicon is preferred in terms of long lifespan.

[0241] As amorphous silicon photoreceptors, for example, a photoreceptor having a photoconductive layer made of a-Si can be used by heating the support to 50°C to 400°C and depositing it on the support using methods such as vacuum deposition, sputtering, ion plating, thermal CVD (chemical vapor deposition), photo-CVD, or plasma CVD. Among these, plasma CVD, that is, a method in which a source gas is decomposed by DC, high-frequency, or microwave glow discharge to form an a-Si deposited film on the support, is preferred.

[0242] There are no particular restrictions on the shape of the electrostatic latent image carrier, and it can be appropriately selected depending on the purpose, but a cylindrical shape is preferred. There are no particular restrictions on the outer diameter of the cylindrical electrostatic latent image carrier, and it can be appropriately selected depending on the purpose, but 3 mm to 100 mm is preferred, 5 mm to 50 mm is more preferred, and 10 mm to 30 mm is particularly preferred.

[0243] (Developing Department) The developing unit includes a developer container for containing a developer according to one embodiment, and a developer carrier for carrying and transporting the developer contained in the developer container. The developing unit may further include regulating members or the like to regulate the thickness of the carried developer.

[0244] Figure 1 shows an example of a process cartridge according to one embodiment. As shown in Figure 1, the image forming apparatus process cartridge 1 includes a photoreceptor drum 11 which is an electrostatic latent image carrier, a corona charger 12 which is a charging unit, an exposure unit 13, a developing unit 14 which is a developing unit, a cleaning unit 15, and a transfer roller 16. In the figure, P represents the transfer paper and L represents the exposure light.

[0245] By mounting the toner storage unit according to one embodiment onto an image forming apparatus and performing image formation, image formation is carried out using the toner according to one embodiment. Therefore, the toner storage unit according to one embodiment can form images with excellent electrostatic properties, low-temperature fixing properties, hot offset resistance, heat storage resistance, and blocking resistance after fixing.

[0246] <Image forming apparatus> An image forming apparatus according to one embodiment includes an electrostatic latent image carrier, an electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, and a developing unit that develops the electrostatic latent image formed on the electrostatic latent image carrier using toner to form a toner image, and may further have other configurations as needed.

[0247] In one embodiment, the image forming apparatus more preferably includes, in addition to the electrostatic latent image carrier, electrostatic latent image forming unit and developing unit, a transfer unit for transferring a toner image to a recording medium and a fixing unit for fixing the transferred image on the surface of the recording medium.

[0248] In the developing section, a toner according to one embodiment is used. Preferably, a developer containing the toner according to one embodiment, and further containing other components such as a carrier as needed, may be used to form a toner image.

[0249] (Electrostatic latent image carrier) The electrostatic latent image carrier can be the same as the one used in the process cartridge described above.

[0250] (Electrostatic latent image formation section) The electrostatic latent image forming unit is not particularly limited as long as it is a means for forming an electrostatic latent image on an electrostatic latent image carrier, and can be appropriately selected according to the purpose. The electrostatic latent image forming unit includes, for example, a charging member (charger) that uniformly charges the surface of the electrostatic latent image carrier, and an exposure member (exposure unit) that exposes the surface of the electrostatic latent image carrier in an image-like manner.

[0251] The charger is not particularly limited and can be appropriately selected depending on the purpose, but examples include contact chargers equipped with conductive or semiconductive rolls, brushes, films, rubber blades, etc., and non-contact chargers that utilize corona discharge such as Corotron and Scorotron.

[0252] The shape of the charger can be anything other than a roller, such as a magnetic brush or a fur brush, and can be selected according to the specifications and configuration of the image forming apparatus.

[0253] Preferably, the charger is positioned in contact with or without contact with the electrostatic latent image carrier, and charges the surface of the electrostatic latent image carrier by superimposing DC and AC voltages. Alternatively, it is preferable that the charger is a charging roller positioned in close proximity to the electrostatic latent image carrier via a gap tape, and charges the surface of the electrostatic latent image carrier by superimposing DC and AC voltages on the charging roller.

[0254] While the charger is not limited to a contact-type charger, it is preferable to use a contact-type charging element because it allows for the creation of an image forming apparatus with reduced ozone generation from the charger.

[0255] The exposure device is not particularly limited as long as it can expose the surface of an electrostatic latent image carrier charged by a charger in the manner of the image to be formed, and can be appropriately selected according to the purpose. Examples of exposure devices include copying optical systems, rod lens array systems, laser optical systems, and liquid crystal shutter optical systems.

[0256] There are no particular restrictions on the light source used in an exposure unit, and it can be appropriately selected according to the purpose. Examples include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light-emitting diodes (LEDs), semiconductor lasers (LDs), electroluminescent devices (ELs), and other types of light-emitting materials.

[0257] Furthermore, various filters such as sharp-cut filters, band-pass filters, near-infrared cut filters, dichroic filters, interference filters, and color temperature conversion filters can be used to illuminate only the desired wavelength range.

[0258] Alternatively, a back-facing method may be employed in which the electrostatic latent image carrier is exposed in an image-like manner from the back side.

[0259] (Developing Department) The developing unit is not particularly limited as long as it can develop the electrostatic latent image formed on the electrostatic latent image carrier to form a visible image, and can be appropriately selected according to the purpose. The developing unit can preferably be one that includes a developer that contains toner and can apply toner to the electrostatic latent image by contact or non-contact, and a developer with a toner container is preferred.

[0260] The developing unit may be a single-color developing unit or a multi-color developing unit. A preferred developing device has, for example, an agitator that frictionally agitates and charges the toner, a magnetic field generating unit fixed inside, and a rotatable developer carrier on which a developer containing toner is carried.

[0261] (Transfer section) The transfer unit preferably has a primary transfer unit that transfers a visible image onto an intermediate transfer unit to form a composite transfer image, and a secondary transfer unit that transfers the composite transfer image onto a recording medium. The intermediate transfer unit is not particularly limited and can be appropriately selected from known transfer units depending on the purpose, for example, a transfer belt is a suitable example.

[0262] The transfer unit (primary transfer means and secondary transfer unit) preferably includes at least a transfer device that peels and charges the visible image formed on the electrostatic latent image carrier (photoconductor) toward the recording medium side. The transfer unit may be one or two or more.

[0263] Examples of the transfer device include a corona transfer device by corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, an adhesive transfer device, etc.

[0264] The recording medium is typically plain paper, but there is no particular limitation as long as it can transfer the undeveloped image after development, and it can be appropriately selected according to the purpose. PET bases for OHP can also be used.

[0265] (Fixing unit) The fixing unit is not particularly limited and can be appropriately selected according to the purpose, but a known heating and pressure applying unit is preferable. Examples of the heating and pressure applying unit include a combination of a heating roller and a pressure applying roller, a combination of a heating roller, a pressure applying roller, and an endless belt, etc.

[0266] The fixing unit preferably has a heating body having a heating element, a film in contact with the heating body, and a pressure applying member that is press-fitted to the heating body through the film, and is a heating and pressure applying unit that can heat and fix by passing the recording medium on which the undeveloped image is formed between the film and the pressure applying member.

[0267] The heating in the heating and pressure applying unit is usually preferably 80°C to 200°C.

[0268] The surface pressure in the heating and pressure applying unit is not particularly limited and can be appropriately selected according to the purpose, but it is preferably 10 N / cm 2 ~80 N / cm 2 is preferable.

[0269] In this embodiment, depending on the purpose, a known light fixing device may be used together with or instead of the fixing unit.

[0270] (Others) An image forming apparatus according to one embodiment may also include, for example, a static elimination unit, a recycling unit, a control unit, and the like.

[0271] ((Static elimination section)) The static elimination unit is not particularly limited and only needs to be able to apply a static elimination bias to the electrostatic latent image carrier. It can be appropriately selected from known static eliminators, for example, a static elimination lamp is a suitable example.

[0272] ((Cleaning Department)) The cleaning unit only needs to be able to remove toner remaining on the electrostatic latent image carrier, and can be appropriately selected from known cleaners. Examples of cleaning units include magnetic brush cleaners, electrostatic brush cleaners, magnetic roller cleaners, blade cleaners, brush cleaners, and web cleaners.

[0273] The image forming apparatus according to the primary form can improve cleaning performance by having a cleaning unit. That is, by controlling the adhesion force between toners, the fluidity of the toner can be controlled, thereby improving cleaning performance.

[0274] Furthermore, by controlling the characteristics of the toner after degradation, excellent cleaning quality can be maintained even under harsh conditions such as prolonged use or high temperature and humidity. In addition, since the external additive can be sufficiently released from the toner on the photoreceptor, a deposit layer (dam layer) of the external additive can be formed in the cleaning blade nip, thereby achieving high cleaning performance.

[0275] ((Recycling Department)) The recycling department is not particularly restricted and can use known means of transport, etc.

[0276] ((Control Unit)) The control unit can control the movement of each of the above-mentioned parts. The control unit is not particularly limited as long as it can control the movement of each of the above-mentioned parts, and can be appropriately selected according to the purpose. Examples include control devices such as sequencers and computers.

[0277] An image forming apparatus according to one embodiment can perform image formation using a toner according to one embodiment, and can therefore provide images with excellent electrostatic properties, low-temperature fixing properties, hot offset resistance, and blocking resistance after fixing.

[0278] Figure 2 is a schematic diagram showing an example of an image forming apparatus according to one embodiment. As shown in Figure 2, the image forming apparatus 100A comprises a photoreceptor drum 10 which is an electrostatic latent image carrier, a charging roller 20 which is a charging unit, an exposure unit 30 which is an exposure unit, a developing unit 40 which is a developing unit, an intermediate transfer body (intermediate transfer belt) 50, a cleaning unit 60 which is a cleaning unit, a transfer roller 70 which is a transfer unit, a static elimination lamp 80 which is a static elimination unit, and an intermediate transfer body cleaning unit 90.

[0279] The intermediate transfer body 50 is an endless belt stretched by three rollers 51 located on the inside, and is designed to be movable in the direction of the arrow by the three rollers 51. Some of the three rollers 51 also function as transfer bias rollers capable of applying a predetermined transfer bias (primary transfer bias) to the intermediate transfer body 50.

[0280] An intermediate transfer body cleaning device 90 is positioned near the intermediate transfer body 50. Furthermore, a transfer roller 70 is positioned opposite the intermediate transfer body 50, and a transfer bias (secondary transfer bias) can be applied to transfer the developed image (toner image) onto the transfer paper P, which is a recording medium (secondary transfer).

[0281] Around the intermediate transfer member 50, a corona charger 52 for charging the toner image on the intermediate transfer member 50 is disposed between the contact portion of the photoreceptor drum 10 and the intermediate transfer member 50 and the contact portion of the intermediate transfer member 50 and the transfer paper P with respect to the rotation direction of the intermediate transfer member 50.

[0282] The developing device 40 includes a developing belt 41 as a developer carrier, and black (Bk) developing units 42K, yellow (Y) developing units 42Y, magenta (M) developing units 42M, and cyan (C) developing units 42C provided around the developing belt 41.

[0283] The developing belt 41 is an endless belt stretched by a plurality of belt rollers and can move in the direction of the arrow in the figure. Further, a part of the developing belt 41 is in contact with the photoreceptor drum 10.

[0284] The black developing unit 42K includes a developer storage portion 421K, a developer supply roller 422K, and a developing roller (developer carrier) 423K. The yellow developing unit 42Y includes a developer storage portion 421Y, a developer supply roller 422Y, and a developing roller 423Y. The magenta developing unit 42M includes a developer storage portion 421M, a developer supply roller 422M, and a developing roller 423M. The cyan developing unit 42C includes a developer storage portion 421C, a developer supply roller 422C, and a developing roller 423C.

[0285] Next, a method of forming an image using the image forming apparatus 100A will be described. First, after uniformly charging the surface of the photoreceptor drum 10 using the charging roller 20, exposure light L is applied to the photoreceptor drum 10 using the exposure apparatus 30 to form an electrostatic latent image. Next, the electrostatic latent image formed on the photoreceptor drum 10 is developed with toner supplied from the developing device 40 to form a toner image.

[0286] Furthermore, the toner image formed on the photoreceptor drum 10 is transferred (primary transfer) onto the intermediate transfer body 50 by a transfer bias applied from the roller 51, and then transferred (secondary transfer) onto the transfer paper P fed by a paper feeding unit (not shown) by a transfer bias applied from the transfer roller 70.

[0287] Meanwhile, the photoreceptor drum 10, on which the toner image has been transferred to the intermediate transfer body 50, is de-staticized by the static elimination lamp 80 after the toner remaining on its surface is removed by the cleaning device 60. The remaining toner on the intermediate transfer body 50 after image transfer is removed by the intermediate transfer body cleaning device 90.

[0288] After the transfer process is complete, the transfer paper P is transported to the fixing unit, where the transferred toner image is fixed to the transfer paper P.

[0289] Figure 3 is a schematic diagram showing another example of an image forming apparatus according to one embodiment. As shown in Figure 3, the image forming apparatus 100B has the same configuration as the image forming apparatus 100A shown in Figure 2, except that the developing belt 41 is not provided, and the black developing unit 42K, yellow developing unit 42Y, magenta developing unit 42M, and cyan developing unit 42C are arranged directly opposite each other around the photoreceptor drum 10.

[0290] Figure 4 is a schematic diagram showing another example of an image forming apparatus according to one embodiment. As shown in Figure 4, the image forming apparatus 100C is a tandem-type color image forming apparatus and includes a copy device body 110, a paper feed table 120, a scanner 130, an automatic document feeder (ADF) 140, a secondary transfer device 150, a fixing unit which is a fixing device 160, and a sheet reversing device 170.

[0291] An endless belt-shaped intermediate transfer body 50 is provided in the center of the main body 110 of the copying device. The intermediate transfer body 50 is an endless belt stretched over three rollers 53A, 53B, and 53C, and can move in the direction of the arrow in Figure 4. Near roller 53B, an intermediate transfer body cleaning device 90 is positioned to remove toner remaining on the intermediate transfer body 50 after the toner image has been transferred to the recording paper.

[0292] An image forming unit (yellow (Y) developing unit 42Y, cyan (C) developing unit 42C, magenta (M) developing unit 42M, and black (Bk) developing unit 42K) is positioned opposite the intermediate transfer body 50, which is stretched by rollers 53A and 53B, and along the transport direction.

[0293] Furthermore, an exposure device 30 is located near the image forming unit. In addition, a secondary transfer device 150 is located on the side of the intermediate transfer body 50 opposite to the side where the image forming unit is located. The secondary transfer device 150 includes a secondary transfer belt 151. The secondary transfer belt 151 is an endless belt stretched over a pair of rollers 152, and the recording paper and the intermediate transfer body 50 being transported on the secondary transfer belt 151 can come into contact between the roller 53C and the roller 152.

[0294] Furthermore, a fixing device 160 is positioned near the secondary transfer belt 151. The fixing device 160 comprises a fixing belt 161, which is an endless belt stretched over a pair of rollers, and a pressure roller 162 that is positioned under pressure from the fixing belt 161.

[0295] Furthermore, a sheet reversing device 170 is positioned near the secondary transfer belt 151 and the fixing device 160 to reverse the recording paper when forming an image on both sides of the recording paper.

[0296] Next, a method for forming a full-color image using the image forming apparatus 100C will be described. First, a color document is placed on the document glass 141 of the automatic document feeder (ADF) 140, or the automatic document feeder 140 is opened and the color document is placed on the contact glass 131 of the scanner 130, and the automatic document feeder 140 is closed.

[0297] When the start switch (not shown) is pressed, if a color document is placed in the automatic document transporter 140, the color document is transported and moved onto the contact glass 131, after which the scanner 130 is activated and the first and second traveling bodies 132 and 133, which are equipped with light sources, move. On the other hand, if a document is placed on the contact glass 131, the scanner 130 is activated immediately and the first and second traveling bodies 132 and 133, which are equipped with light sources, move.

[0298] At this time, the light emitted from the first traveling body 132 is reflected from the original document surface by the mirror of the second traveling body 133, and then received by the reading sensor 136 through the imaging lens 135, thereby reading the color original (color image) and obtaining image information in black, yellow, magenta, and cyan.

[0299] Image information for each color is transmitted to the respective color developing units (yellow developing unit 42Y, cyan developing unit 42C, magenta developing unit 42M, and black developing unit 42K), and toner images for each color are formed.

[0300] Figure 5 is a partially enlarged view of the image forming apparatus shown in Figure 4. As shown in Figure 5, each developing unit (yellow developing unit 42Y, cyan developing unit 42C, magenta developing unit 42M, and black developing unit 42K) is equipped with a charging roller 20, which is a charging part that uniformly charges the black photoreceptor drum 10K, the yellow photoreceptor drum 10Y, the magenta photoreceptor drum 10M, and the cyan photoreceptor drum 10C, respectively.

[0301] Each developing unit further includes an exposure device 30, shown in Figure 4, which exposes each photoreceptor drum 10K, 10Y, 10M, and 10C with exposure light L based on the image information of each color to form electrostatic latent images of each color on the photoreceptor drums 10K, 10Y, 10M, and 10C; a developing device 40, which is a developing section that develops the electrostatic latent images with developers of each color to form toner images of each color; a transfer charger 62 for transferring the toner images onto an intermediate transfer body 50; a cleaning device 60; and an anti-static lamp 80.

[0302] The toner images of each color formed by the respective color developing units (yellow developing unit 42Y, cyan developing unit 42C, magenta developing unit 42M, and black developing unit 42K) are sequentially transferred (primary transfer) onto an intermediate transfer body 50 that is stretched and moved on rollers 53A, 53B, and 53C. Then, the toner images of each color are superimposed on the intermediate transfer body 50 to form a composite toner image.

[0303] On the other hand, as shown in Figure 4, the paper feed table 120 selectively rotates one of the paper feed rollers 121 to feed recording paper from one of the paper feed cassettes 123 arranged in multiple stages in the paper bank 122.

[0304] The recording paper is separated one sheet at a time by the separation roller 124 and fed into the paper feed path 125, transported by the transport roller 126 and guided into the paper feed path 111 in the copy machine body 110, where it is stopped by the registration roller 112. Alternatively, the manual feed roller 113 is rotated to feed the recording paper from the manual feed tray 114, separates it one sheet at a time by the manual feed roller 113 and guides it into the manual feed path 115, where it is stopped by the registration roller 112.

[0305] Although the registration roller 112 is generally used with grounding, it may also be used with a bias applied to remove paper dust from the recording paper.

[0306] Next, the register roller 112 is rotated in time with the composite toner image formed on the intermediate transfer body 50, and recording paper is fed between the intermediate transfer body 50 and the secondary transfer belt 151 to transfer the composite toner image onto the recording paper (secondary transfer). Any toner remaining on the intermediate transfer body 50 on which the composite toner image has been transferred is removed by the intermediate transfer body cleaning device 90.

[0307] After the composite toner image is transferred to the recording paper, it is transported by the secondary transfer belt 151, and then the composite toner image is fixed onto the recording paper by the fixing device 160.

[0308] Subsequently, the transport path of the recording paper is switched by the switching claw 116, and the recording paper is discharged onto the output tray 118 by the discharge roller 117. Alternatively, the transport path of the recording paper is switched by the switching claw 116, the recording paper is inverted by the sheet inversion device 170, and then guided again to the secondary transfer belt 151, where an image is formed on the reverse side in the same manner, and then discharged onto the output tray 118 by the discharge roller 117.

[0309] <Image forming method> An image forming method according to one embodiment includes an electrostatic latent image formation step of forming an electrostatic latent image on an electrostatic latent image carrier, and a development step of developing the electrostatic latent image using toner to form a toner image, and may further include other steps as necessary. The image forming method according to one embodiment can be suitably carried out by an image forming apparatus according to one embodiment, the electrostatic latent image formation step can be suitably carried out by an electrostatic latent image formation unit, the development step can be suitably carried out by a development unit, and the other steps can be suitably carried out by other units.

[0310] Furthermore, the image forming method according to one embodiment more preferably includes, in addition to the electrostatic latent image formation step and the development step described above, a transfer step for transferring a toner image to a recording medium and a fixing step for fixing the transferred image on the surface of the recording medium.

[0311] In the development process, a toner according to one embodiment is used. Preferably, a developer containing the toner according to one embodiment, and optionally containing other components such as a carrier, may be used to form a toner image.

[0312] The electrostatic latent image formation process is a process of forming an electrostatic latent image on an electrostatic latent image carrier, and includes a charging step of charging the surface of the electrostatic latent image carrier and an exposure step of exposing the charged surface of the electrostatic latent image carrier to form an electrostatic latent image.

[0313] Charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using a charger. Exposure can be performed, for example, by exposing the surface of the electrostatic latent image carrier in an image-like manner using an exposure unit. Formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then exposing it in an image-like manner, and this can be done by an electrostatic latent image forming unit.

[0314] The development process is a process of sequentially developing an electrostatic latent image with multiple toners to form a visible image. The formation of the visible image can be done, for example, by developing the electrostatic latent image using toner, and this can be done using a developing unit.

[0315] Inside the developing unit, for example, toner and carrier are mixed and stirred, and the friction during this process causes the toner to become charged. This charge is then held in a pile-like state on the surface of the rotating magnetic roller, forming a magnetic brush. Since the magnetic roller is positioned near the electrostatic latent image carrier (photoreceptor), some of the toner that makes up the magnetic brush formed on the surface of the magnetic roller moves to the surface of the electrostatic latent image carrier (photoreceptor) due to electrical attraction. As a result, the electrostatic latent image is developed by the toner, and a visible image is formed on the surface of the electrostatic latent image carrier (photoreceptor) by the toner.

[0316] The transfer process is a process of transferring a visible image to a recording medium. Preferably, the transfer process uses an intermediate transfer medium, first transferring the visible image onto the intermediate transfer medium, and then second transferring the visible image onto the recording medium. More preferably, the transfer process includes a first transfer process using two or more toners, preferably full-color toners, to transfer the visible image onto the intermediate transfer medium to form a composite transfer image, and a second transfer process to transfer the composite transfer image onto the recording medium.

[0317] Transfer can be performed, for example, by charging an electrostatic latent image carrier (photoreceptor) with a transfer charger using a visible image, and this can be done by the transfer unit.

[0318] The fixing process is the process of fixing the visible image transferred to the recording medium using a fixing device. This process may be performed for each color developer after the image is transferred to the recording medium, or it may be performed simultaneously for each color developer in a stacked state.

[0319] The image formation method for the primary form may further include other steps as appropriate, such as static elimination steps, cleaning steps, and recycling steps.

[0320] The static elimination process involves applying a static elimination bias to the electrostatic latent image carrier to remove static electricity, and this process can be more effectively performed by the static elimination unit.

[0321] The cleaning process is a process of removing toner remaining on the electrostatic latent image carrier, and can be performed more effectively by the cleaning unit.

[0322] The recycling process involves recycling the toner removed during the cleaning process into the developing unit, and can be performed more effectively in the recycling unit.

[0323] The image forming method according to one embodiment can perform image forming using the toner according to one embodiment, and therefore can provide an image with excellent electrostatic properties, low-temperature fixing properties, hot offset resistance, and blocking resistance after fixing. [Examples]

[0324] The embodiments will be described in more detail below with reference to examples and comparative examples, but the embodiments are not limited to these examples and comparative examples.

[0325] <Manufacturing Example A-1: ​​Synthesis of Prepolymer A-1> 3-methyl-1,5-pentanediol, isophthalic acid, and adipic acid were added to a reaction vessel equipped with a heating device, condenser, stirrer, and nitrogen inlet tube, together with titanium tetraisopropoxide (1000 ppm relative to the resin component). At this time, the molar ratio of hydroxyl groups to carboxyl groups (OH / COOH) was 1.1, the composition of the diol component was 110 mol% 3-methyl-1,5-pentanediol, and the composition of the dicarboxylic acid component was 40 mol% isophthalic acid and 60 mol% adipic acid.

[0326] Subsequently, the temperature was raised to 200°C over approximately 4 hours, and then to 230°C over 2 hours, and the reaction was continued until all effluent was gone. After that, the reaction was further carried out under reduced pressure of 10 mmHg to 15 mmHg for 5 hours to obtain intermediate polyester A-1.

[0327] Next, intermediate polyester A-1 and hexamethylene isocyanate derivative (HDI isocyanurate) were added to a reaction vessel equipped with a heating device, cooling tubes, a stirrer, and nitrogen inlet tube, such that the molar ratio (NCO / OH) of the isocyanate groups of HDI isocyanurate to the hydroxyl groups of intermediate polyester A-1 was 2.0. Ethyl acetate was then added to dissolve the mixture in a 50% ethyl acetate solution.

[0328] Subsequently, the mixture was heated to 80°C under a nitrogen atmosphere and reacted for 5 hours to obtain an ethyl acetate solution of a prepolymer having isocyanate groups at its ends (NCO group-terminated prepolymer A-1). Then, the pressure was reduced until the amount of residual ethyl acetate in the ethyl acetate solution of NCO group-terminated prepolymer A-1 was 100 ppm or less.

[0329] Next, NCO group-terminated prepolymer A-1 and sodium dimethyl isophthalic acid 5-sulfonate were added to a reaction vessel equipped with a heating device, cooling tubes, a stirrer, and nitrogen inlet tubes, in a molar ratio (SO3H / NCO) of 1.0, and reacted at 150°C for 6 hours. This yielded a nonlinear polymer, a sulfonic acid-terminated prepolymer (prepolymer A-1).

[0330] <Manufacturing Example A-2: Synthesis of Prepolymer A-2> In a reaction vessel equipped with a heating device, condenser, stirrer, and nitrogen inlet tube, 3-methyl-1,5-pentanediol, isophthalic acid, adipic acid, and trimellitic anhydride were added together with titanium tetraisopropoxide (1,000 ppm relative to the resin component). At this time, the molar ratio of hydroxyl groups to carboxyl groups (OH / COOH) was 1.1, the composition of the diol component was 110 mol% 3-methyl-1,5-pentanediol, the composition of the dicarboxylic acid component was 40 mol% isophthalic acid and 60 mol% adipic acid, and the amount of trimellitic anhydride in the total monomer was 1 mol%.

[0331] Subsequently, the temperature was raised to 200°C over approximately 4 hours, and then to 230°C over 2 hours, and the reaction was continued until all effluent was gone. After that, the reaction was further carried out under reduced pressure of 10 mmHg to 15 mmHg for 5 hours to obtain the intermediate polyester A-2.

[0332] Next, intermediate polyester A-2 and hexamethylene isocyanate derivative (HDI isocyanurate) were added to a reaction vessel equipped with a heating device, cooling tubes, a stirrer, and nitrogen inlet tube, such that the molar ratio (NCO / OH) of the isocyanate groups of HDI isocyanurate to the hydroxyl groups of intermediate polyester A-2 was 2.0. Ethyl acetate was then added to dissolve the mixture in a 50% ethyl acetate solution.

[0333] Subsequently, the mixture was heated to 80°C under a nitrogen atmosphere and reacted for 5 hours to obtain an ethyl acetate solution of a prepolymer having isocyanate groups at its ends (NCO group-terminated prepolymer A-2). Then, the pressure was reduced until the amount of residual ethyl acetate in the ethyl acetate solution of NCO group-terminated prepolymer A-2 was 100 ppm or less.

[0334] Next, NCO group-terminated prepolymer A-2 and sodium dimethyl isophthalic acid 5-sulfonate were added to a reaction vessel equipped with a heating device, cooling tubes, a stirrer, and nitrogen inlet tubes in a molar ratio (SO3H / NCO) of 1.0 and reacted at 150°C for 6 hours. This yielded a nonlinear polymer, a sulfonic acid-terminated prepolymer (prepolymer A-2).

[0335] <Manufacturing Example a-1: Synthesis of Prepolymer a-1> 3-methyl-1,5-pentanediol, isophthalic acid, and adipic acid were added to a reaction vessel equipped with a heating device, condenser, stirrer, and nitrogen inlet tube, together with titanium tetraisopropoxide (1000 ppm relative to the resin component). At this time, the molar ratio of hydroxyl groups to carboxyl groups (OH / COOH) was 1.1, the composition of the diol component was 110 mol% 3-methyl-1,5-pentanediol, and the composition of the dicarboxylic acid component was 40 mol% isophthalic acid and 60 mol% adipic acid.

[0336] Subsequently, the temperature was raised to 200°C over approximately 4 hours, and then to 230°C over 2 hours, and the reaction was continued until all effluent was gone. After that, the reaction was further carried out under reduced pressure of 10 mmHg to 15 mmHg for 5 hours to obtain intermediate polyester a-1.

[0337] Next, intermediate polyester a-1 and hexamethylene isocyanate derivative (HDI isocyanurate) were added to a reaction vessel equipped with a heating device, cooling tubes, a stirrer, and nitrogen inlet tube, such that the molar ratio (NCO / OH) of the isocyanate groups of HDI isocyanurate to the hydroxyl groups of intermediate polyester a-1 was 2.0. Ethyl acetate was then added to dissolve the mixture in a 50% ethyl acetate solution.

[0338] Subsequently, the mixture was heated to 80°C under a nitrogen atmosphere and reacted for 5 hours to obtain an ethyl acetate solution of a prepolymer having isocyanate groups at its ends (NCO group-terminated prepolymer a-1). Then, the pressure was reduced until the amount of residual ethyl acetate in the ethyl acetate solution of NCO group-terminated prepolymer a-1 was 100 ppm or less.

[0339] Next, in a reaction vessel equipped with a heating device, cooling tubes, a stirrer, and nitrogen inlet tubes, NCO group-terminated prepolymer a-1 and monomethyl succinic acid were added so that the molar ratio (CH3 / NCO) of the methyl groups of monomethyl succinic acid to the hydroxyl groups of NCO group-terminated prepolymer a-1 was 2.0, and the mixture was reacted at 150°C for 6 hours. This yielded a nonlinear polymer, a carboxylic acid-terminated prepolymer (prepolymer a-1).

[0340] <Manufacturing Example a-2: Synthesis of Prepolymer a-2> In a reaction vessel equipped with a heating device, condenser, stirrer, and nitrogen inlet tube, 3-methyl-1,5-pentanediol, isophthalic acid, adipic acid, and trimellitic anhydride were added together with titanium tetraisopropoxide (1,000 ppm relative to the resin component). At this time, the molar ratio of hydroxyl groups to carboxyl groups (OH / COOH) was 1.1, the composition of the diol component was 110 mol% 3-methyl-1,5-pentanediol, the composition of the dicarboxylic acid component was 40 mol% isophthalic acid and 60 mol% adipic acid, and the amount of trimellitic anhydride in the total monomer was 1 mol%.

[0341] Subsequently, the temperature was raised to 200°C over approximately 4 hours, and then to 230°C over 2 hours, and the reaction was continued until all effluent was gone. After that, the reaction was further carried out under reduced pressure of 10 mmHg to 15 mmHg for 5 hours to obtain the intermediate polyester a-2.

[0342] Next, intermediate polyester a-2 and isophorone diisocyanate (IPDI) were added to a reaction vessel equipped with a heating device, cooling tubes, a stirrer, and nitrogen inlet tube, such that the molar ratio (NCO / OH) of the hydroxyl groups of intermediate polyester a-2 to the isocyanate groups of IPDI was 2.0. After diluting with ethyl acetate to a 50% ethyl acetate solution, the mixture was reacted at 100°C for 5 hours. This yielded a nonlinear polymer, prepolymer a-2, which has isocyanate groups at its ends.

[0343] <Manufacturing Example a-3: Synthesis of Prepolymer a-3> 3-methyl-1,5-pentanediol, isophthalic acid, and adipic acid were added to a reaction vessel equipped with a heating device, condenser, stirrer, and nitrogen inlet tube, along with titanium tetraisopropoxide (1,000 ppm relative to the resin component). At this time, the molar ratio of hydroxyl groups to carboxyl groups (COOH / OH) was 1.1, the composition of the diol component was 100 mol% 3-methyl-1,5-pentanediol, and the composition of the dicarboxylic acid component was 50 mol% isophthalic acid and 60 mol% adipic acid.

[0344] Subsequently, the temperature was raised to 200°C over approximately 4 hours, and then to 230°C over 2 hours, and the reaction was continued until all effluent was gone. After that, the reaction was further carried out under reduced pressure of 10 mmHg to 15 mmHg for 5 hours to obtain a linear prepolymer (prepolymer a-3) having hydroxyl groups at its ends.

[0345] <Manufacturing Example B: Synthesis of Amorphous Polyester Resin B> A four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was charged with 2 molar bisphenol A ethylene oxide side adduct, 3 molar bisphenol A propylene oxide adduct, isophthalic acid, and adipic acid, such that the molar ratio of 2 molar bisphenol A ethylene oxide side adduct to 3 molar bisphenol A propylene oxide adduct was 85 / 15, the molar ratio of isophthalic acid to adipic acid was 80 / 20, and the molar ratio of hydroxyl groups to carboxyl groups (OH / COOH) was 1.3.

[0346] Then, this mixture was reacted with titanium tetraisopropoxide (500 ppm relative to the resin component) at atmospheric pressure at 230°C for 8 hours, followed by a further reaction under reduced pressure of 10 mmHg to 15 mmHg for 4 hours. After that, trimellitic anhydride was added to the reaction vessel to a concentration of 1 mol% relative to the total resin component. Subsequently, the reaction was carried out at 180°C and atmospheric pressure for 3 hours. This yielded amorphous polyester resin B.

[0347] <Manufacturing Example C-1: Synthesis of Crystalline Polyester Resin C-1> Dodecanediol and 1,6-hexanediol were charged into a 5L four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple, so that the molar ratio of hydroxyl groups to carboxyl groups (OH / COOH) was 0.9.

[0348] Subsequently, this mixture was reacted with titanium tetraisopropoxide (500 ppm relative to the resin component) at 180°C for 10 hours, then the temperature was raised to 200°C and the reaction was continued for 3 hours, followed by a further reaction at a pressure of 8.3 kPa for 2 hours. This yielded crystalline polyester resin C-1.

[0349] <Manufacturing Example C-2: Synthesis of Crystalline Polyester Resin C-2> A 5L four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple was charged with 1,6-hexanediol and sebacic acid in such a molar ratio (OH / COOH) of hydroxyl groups to carboxyl groups as 1.1. This mixture was reacted with titanium tetraisopropoxide (500 ppm relative to the resin component) while effluent, and the reaction was carried out at 235°C for 1 hour. Subsequently, the reaction was carried out under reduced pressure of 10 mmHg or less for 6 hours.

[0350] Subsequently, the temperature was set to 185°C, and trimellitic anhydride was added in a molar ratio of 0.053 to COOH groups. The mixture was then stirred and reacted for 2 hours. This yielded crystalline polyester resin C-2.

[0351] <Toner production> [Example 1] In this example, toner was prepared using the dissolution-suspension method.

[0352] (Masterbatch (MB) synthesis) 1200 parts by mass of water, 500 parts by mass of carbon black (Printex35, manufactured by DEXA, DBP oil absorption = 42 mL / 100 mg, pH = 9.5), and 500 parts by mass of amorphous polyester B were added to a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) and mixed. The mixture was kneaded at 150°C for 30 minutes using two rolls, then rolled and cooled, and pulverized in a pulperizer. This obtained masterbatch 1.

[0353] (Preparation of wax dispersion) A container equipped with a stirring rod and thermometer was charged with 50 parts by mass of paraffin wax (HNP-9, manufactured by Nippon Seiro Co., Ltd., hydrocarbon wax, melting point 75°C, SP value 8.8) and 450 parts of ethyl acetate as a release agent. The mixture was heated to 80°C under stirring and maintained at 80°C for 5 hours.

[0354] Subsequently, the mixture was cooled to 30°C in 1 hour, and dispersion was performed using a bead mill (UltraViscomill, manufactured by AIMEX) under three pass conditions with a liquid delivery rate of 1 kg / hour, a disk peripheral speed of 6 m / sec, and 80% volume of 0.5 mm zirconia beads packed into the mill. This yielded wax dispersion 1.

[0355] (Preparation of crystalline polyester resin dispersion) 50 parts by mass of crystalline polyester resin C-1 and 450 parts by mass of ethyl acetate were placed in a container equipped with a stirring rod and thermometer. The mixture was heated to 80°C under stirring and maintained at 80°C for 5 hours. The mixture was then cooled to 30°C in 1 hour, and dispersion was performed using a bead mill (Ultraviscomill, manufactured by AIMEX) with a liquid transfer rate of 1 kg / hour, a disk peripheral speed of 6 m / sec, and 80% by volume of 0.5 mm zirconia beads packed into the mixture, under 3-pass conditions. This yielded crystalline polyester resin dispersion 1.

[0356] (Preparation of the oil phase) 500 parts by mass of wax dispersion 1, 300 parts by mass of prepolymer A-1, 500 parts by mass of crystalline polyester resin dispersion 1, 650 parts by mass of amorphous polyester resin B, and 100 parts by mass of masterbatch 1 were placed in a container and mixed at 5000 rpm for 60 minutes using a TK homomixer (manufactured by Tokushu Kika) to obtain oil phase 1.

[0357] (Synthesis of organic microparticle emulsion (microparticle dispersion)) In a reaction vessel equipped with a stirring rod and thermometer, 683 parts by mass of water, 11 parts by mass of sodium salt of ethylene oxide adduct sulfate methacrylate (Eleminol RS-30: manufactured by Sanyo Chemical Industries, Ltd.), 138 parts by mass of styrene, 138 parts by mass of methacrylic acid, and 1 part by mass of ammonium persulfate were charged. When this mixture was stirred at 400 rpm for 15 minutes, a white emulsion was obtained.

[0358] The resulting emulsion was heated to a system temperature of 75°C and reacted for 5 hours. Furthermore, 30 parts by mass of a 1% ammonium persulfate aqueous solution were added, and the mixture was aged at 75°C for 5 hours to obtain an aqueous dispersion of vinyl resin (styrene-methacrylic acid-methacrylate ethylene oxide adduct sulfate sodium salt copolymer) (fine particle dispersion 1). The volume-average particle size of the fine particles contained in the obtained fine particle dispersion 1 was measured using an LA-920 (manufactured by HORIBA). The volume-average particle size was 0.14 μm.

[0359] (Preparation of the aqueous phase) 690 parts by mass of water, 83 parts by mass of fine particle dispersion 1, 37 parts by mass of a 48.5% aqueous solution of sodium dodecyldiphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries, Ltd.), 90 parts by mass of ethyl acetate, and 300 parts by mass of 5% magnesium sulfate solution were mixed and stirred to obtain a milky white liquid. This was designated as aqueous phase 1. In this example, a 5% magnesium sulfate solution was used as the aqueous solution of the metal salt, and magnesium ions (Mg) contained in the magnesium sulfate solution were used. 2+ ) functions as a crosslinking agent.

[0360] (Emulsification and desolvation) 1200 parts by mass of aqueous phase 1 were added to a container containing oil phase 1, and the mixture was mixed in a TK homomixer at a rotation speed of 13000 rpm for 20 minutes to obtain emulsified slurry 1. The obtained emulsified slurry 1 was placed in a container equipped with a stirrer and thermometer, desolvented at 30°C for 8 hours, and then aged at 45°C for 4 hours to obtain dispersed slurry 1. In this example, magnesium ions metal-crosslink at the ends of prepolymer A-1 in dispersed slurry 1, generating a nonlinear polymer which is a crosslinking component.

[0361] (Washing and drying) After filtering 100 parts by mass of the dispersed slurry 1 under reduced pressure, the following operations (1) to (4) were performed twice to obtain the filtered cake 1. (1): 100 parts of deionized water were added to the filter cake, mixed with a TK homomixer (rotating at 12,000 rpm for 10 minutes), and then filtered. (2): 100 parts by mass of a 10% sodium hydroxide aqueous solution was added to the filtered cake from (1), mixed with a TK homomixer (at a rotation speed of 12,000 rpm for 30 minutes), and then filtered under reduced pressure. (3): Add 100 parts of 10% hydrochloric acid to the filtered cake from (2), mix with a TK homomixer (at 12,000 rpm for 10 minutes), and then filter. (4): 300 parts by mass of deionized water were added to the filtered cake from (3), mixed with a TK homomixer (at a rotation speed of 12,000 rpm for 10 minutes), and then filtered to obtain toner base 1.

[0362] (External processing) Toner matrix 1 was mixed with 0.6 parts by mass of hydrophobic silica with an average particle size of 100 nm, 1.0 part by mass of titanium dioxide with an average particle size of 20 nm, and 0.8 parts of hydrophobic silica fine powder with an average particle size of 15 nm per 100 parts by mass of toner matrix 1 using a Henschel mixer. This yielded toner 1.

[0363] (Number of branches in the cross-linking component) Since prepolymer A-1 is obtained by reacting the hydroxyl group of intermediate polyester A-1 with the isocyanate group of HDI isocyanurate, it is considered that the number of branches in the crosslinking component contained in the resulting toner 1 is three or more.

[0364] (Glass transition temperature Tg of DSC of prepolymer) Prepolymer A-1 was separated from Toner 1 using the Soxhlet extraction method. 5.0 mg of the target sample, prepolymer A-1, was placed in an aluminum sample container, which was then placed on a holder unit and set in an electric furnace. Next, under a nitrogen atmosphere, it was heated from -80°C to 150°C at a heating rate of 10°C / min (first heating pass). After that, it was cooled from 150°C to -80°C at a cooling rate of 10°C / min.

[0365] Next, prepolymer A-1 was heated under the same conditions as the first heating cycle (second heating cycle). During this second heating cycle, a differential scanning calorimeter ("Q-200", manufactured by TA Instruments Inc.) was used to measure the DSC curve.

[0366] From the obtained DSC curves, the analysis program in the Q-200 system was used to select the DSC curve for the second heating cycle, and the glass transition temperature Tg of prepolymer A-1 during the second heating cycle was determined. 2nd This was determined as the Tg of the DSC of the prepolymer. The glass transition temperature Tg of prepolymer A-1 contained in the obtained toner 1 was -30.7°C.

[0367] [Example 2] In Example 1, during the preparation of the aqueous phase, 690 parts by mass of water, 83 parts by mass of fine particle dispersion 1, 37 parts by mass of a 48.5% aqueous solution of sodium dodecyldiphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries, Ltd.), 90 parts by mass of ethyl acetate, 300 parts by mass of a 5% magnesium sulfate solution, and 150 parts by mass of a 5% aluminum sulfate solution were mixed and stirred to obtain a milky white liquid. This was designated as aqueous phase 2.

[0368] In this example, a 5% magnesium sulfate solution and a 5% aluminum sulfate solution were used as aqueous solutions of the metal salt, and the magnesium ions (Mg) contained in the magnesium sulfate solution were used. 2+ ) and aluminum ions (Al) contained in a 5% aluminum sulfate solution 3+ ) and function as crosslinking agents. Toner 2 was prepared under the same conditions as in Example 1, except for the preparation of the aqueous phase.

[0369] The number of branches in the crosslinking component contained in the obtained toner 2 is considered to be 3 or more, similar to Example 1. The glass transition temperature Tg of prepolymer A-1 was -34.4°C.

[0370] [Example 3] In Example 1, the procedure was carried out in the same manner as in Example 1, except that the prepolymer was changed from prepolymer A-1 to prepolymer A-2, to obtain toner 3. The number of branches in the crosslinking component contained in the obtained toner 3 is considered to be 3 or more, similar to Example 1. The glass transition temperature Tg of prepolymer A-2 was -35.9°C.

[0371] [Example 4] In Example 2, the procedure was the same as in Example 2, except that the prepolymer was changed from prepolymer A-1 to prepolymer A-2, to obtain toner 4. The number of branches in the crosslinking component contained in the obtained toner 4 is considered to be 3 or more, similar to Example 2. The glass transition temperature Tg of prepolymer A-2 was -35.9°C.

[0372] [Example 5] In this example, toner was prepared using the emulsification and agglutination method.

[0373] (Manufacturing of wax emulsions) To 100 parts by mass of deionized water, 28 parts by mass of wax (HNP-9, manufactured by Nippon Seiro Co., Ltd.) and benzalkonium chloride solution (Sanisol® B50, manufactured by Kao Corporation) as a surfactant were added. This mixture was dispersed in a homogenizer while being heated to 90°C to obtain wax emulsion 1. The solid content concentration of wax emulsion 1 was 30%.

[0374] (Preparation of crystalline polyester resin dispersion) 55 parts by mass of crystalline polyester resin C-2, 35 parts by mass of methyl ethyl ketone, and 10 parts by mass of 2-propyl alcohol were added to a four-necked flask. The mixture was then heated and stirred at the melting point of crystalline polyester resin C-2 to dissolve it. Subsequently, a 28% by mass aqueous ammonia solution was added to achieve a neutralization rate of 200%. The neutralization rate was calculated from the acid value of the crystalline polyester resin.

[0375] Furthermore, 130 parts by mass of deionized water was gradually added to perform phase inversion emulsification, followed by desolvation. Subsequently, deionized water was added to adjust the solid content concentration (concentration of crystalline polyester resin) to 25% by mass, thereby obtaining crystalline polyester resin dispersion 2, which is a binder resin dispersion for toner. The particle size of the crystalline polyester resin in crystalline polyester resin dispersion 2 was 250 nm.

[0376] (Preparation of the oil phase) In a four-necked flask, 71 parts by mass of amorphous polyester resin B, 30 parts by mass of prepolymer A-2, and 5 parts by mass of carbon black were added. Then, 100 parts by mass of ethyl acetate was added, and the mixture was stirred to dissolve and disperse the components. Subsequently, 5 parts by mass of 28% by mass aqueous ammonia solution was added to achieve a neutralization rate of 400%. This yielded oil phase 5.

[0377] (Emulsification and desolvation) Phase inversion emulsification was performed by gradually adding 300 parts by mass of a 2% sodium dodecyl sulfate aqueous solution to the oil phase 5. Then, desolvation was carried out to obtain emulsion slurry 5. The particle size of emulsion slurry 5 was measured to be 0.50 μm. The solid content concentration of emulsion slurry 5 was measured to be 23.0%.

[0378] (Agglomeration and fusion process) 117.5 parts by mass of emulsified slurry 5, 6.0 parts by mass of crystalline polyester resin dispersion 2, 5.0 parts by mass of wax emulsion 1, and 300 parts by mass of deionized water were placed in a container and stirred for 1 minute. Next, 100 parts by mass of 5% magnesium sulfate solution and 50 parts by mass of 5% aluminum sulfate solution were added dropwise to the mixture, stirred for a further 5 minutes, and then the temperature was raised to 60°C.

[0379] Subsequently, when the particle size reached 5.0 μm, 50 parts by mass of sodium chloride were added to complete the flocculation process and obtain flocculated slurry 1. The flocculated slurry 1 was then heated to 70°C while stirring, and when it reached the desired circularity of 0.960, it was cooled to obtain dispersed slurry 5.

[0380] (Annealing, washing, and drying) The dispersed slurry 5 was stored at 45°C for 10 hours, then filtered under reduced pressure, and washed and dried as follows. This process was repeated until the electrical conductivity of the slurry liquid was 10 μC / cm or less, and then filtered to obtain the filtered cake 5. (1): 100 parts by mass of deionized water were added to the filtration cake, mixed with a TK homomixer (rotation speed 12000 rpm, mixing time 10 minutes), and then filtered. (2): 900 parts by mass of deionized water were added to the filtration cake from (1), and the mixture was mixed in a TK homomixer with ultrasonic vibration (at a rotation speed of 12,000 rpm for 30 minutes), followed by vacuum filtration.

[0381] The filtered cake 5 was dried in a circulating air dryer at 45°C for 48 hours, and then sieved with a 75 μm mesh to obtain the toner base 5.

[0382] (External processing) Toner 5 was obtained by mixing toner matrix 5 with 0.6 parts by mass of hydrophobic silica with an average particle size of 100 nm, 1.0 part by mass of titanium dioxide with an average particle size of 20 nm, and 0.8 parts by mass of hydrophobic silica fine powder with an average particle size of 15 nm, per 100 parts by mass of toner matrix 5, using a Henschel mixer.

[0383] The number of branches in the crosslinking component contained in the obtained toner 5 is considered to be 3 or more, similar to Example 1. The glass transition temperature Tg of prepolymer A-2 was -35.9°C.

[0384] [Comparative Example 1] In Example 2, the procedure was the same as in Example 2, except that the prepolymer was changed from prepolymer A-1 to prepolymer a-1, and toner 6 was obtained. The number of branches in the crosslinking component contained in the obtained toner 6 is considered to be 3 or more, similar to Example 2. The glass transition temperature Tg of prepolymer a-1 was -36.5°C.

[0385] [Comparative Example 2] In Example 2, the preparation of the oil phase and the aqueous phase was changed as described below, but otherwise the same procedure was followed to obtain toner 7. (Preparation of the oil phase) 500 parts by mass of wax dispersion 1, 300 parts by mass of prepolymer a-2, 500 parts by mass of crystalline polyester resin dispersion 1, 700 parts by mass of amorphous polyester resin B, 100 parts by mass of masterbatch 1, and 2 parts by mass of a 20% ethyl acetate solution of IPDA were placed in a container. The mixture was then mixed at 5000 rpm for 60 minutes using a TK homomixer (manufactured by Tokushu Kika) to obtain oil phase 7.

[0386] (Preparation of the aqueous phase) 990 parts by mass of water, 83 parts by mass of fine particle dispersion 1, 37 parts by mass of a 48.5% aqueous solution of sodium dodecyldiphenyl ether disulfonate (Eleminol MON-7, manufactured by Sanyo Chemical Industries, Ltd.), and 90 parts by mass of ethyl acetate were mixed and stirred to obtain a milky white liquid. This was designated as aqueous phase 7.

[0387] The number of branches in the crosslinking component contained in the obtained toner 7 is considered to be three or more, similar to Example 2. The glass transition temperature Tg of prepolymer a-2 was -37.5°C.

[0388] [Comparative Example 3] In Example 2, the procedure was the same as in Example 2, except that the prepolymer was changed from prepolymer A-1 to prepolymer a-3, and toner 8 was obtained. The number of branches in the crosslinking component contained in the obtained toner 8 is considered to be two or less. The glass transition temperature Tg of prepolymer a-3 was -36.5°C.

[0389] <Rating> The electrostatic properties, low-temperature fixing properties, hot offset resistance, heat storage resistance, and blocking resistance of the toners obtained from each example and comparative example were evaluated.

[0390] [Electrifiable] The electrostatic properties of the toner were evaluated by calculating the amount of charge the toner had. Under conditions of 23°C and 53±3% humidity, 0.35g of toner and 5g of carrier were placed in a cylindrical stainless steel container (25mm inner diameter, 30mm height) and allowed to humidify for more than 12 hours. After that, the container was sealed and rotated at 300 rpm for 5 minutes.

[0391] A sample of the toner and carrier mixture was taken from the container, placed in a 400-mesh blow-off gauge, and air-blown at an air pressure of 5 kPa for 3 minutes. The mixture was then measured using a Q / M meter (EPPING). The Q / M meter was set to a mesh size of 400 mesh (stainless steel), a soft blow pressure of 1050 V, and a suction time of 90 seconds. The charge was calculated using the following formula (1). A charge of 20 μC / g or more was considered to indicate good toner charging properties. Charge amount (μC / g) = Total electric charge after 90 seconds (μC) / Amount of toner absorbed (g) ... (1)

[0392] [Low temperature fixation] A developer was obtained by mixing the carrier used in the imageo MP C5503 (manufactured by Ricoh Co., Ltd.) with the toners obtained in the examples and comparative examples, so that the toner concentration in each case was 5%.

[0393] After loading the obtained developer into the imageo MP C5503 unit (manufactured by Ricoh Co., Ltd.), a 2cm x 15cm rectangular solid image was printed on PPC paper type 6000 <70W> A4 T-grain (manufactured by Ricoh Co., Ltd.) with a toner adhesion amount of 0.40 mg / cm². 2 It was formed in such a way.

[0394] At this time, the surface temperature of the fixing roller was changed, and it was observed whether a cold offset occurred, in which the undeveloped image of the solid color was fixed to a location other than the desired location. The temperature at which a cold offset occurs (cold offset temperature or fixing lower limit temperature) was determined and evaluated based on the evaluation criteria below. If the evaluation result was A or B, the obtained toner was considered to have sufficient low-temperature fixing properties that are usable for practical purposes. If the evaluation result was C, the obtained toner was considered to be unusable for practical purposes. (Evaluation Criteria) A: Cold offset temperature is less than 110°C B: Cold offset temperature is 110°C or higher and less than 125°C C: Cold offset temperature is 125°C or higher.

[0395] [Hot offset resistance] The toner's resistance to hot offset was evaluated by measuring the upper limit temperature of the toner's fixing. Copy tests were performed on Type 6200 paper (manufactured by Ricoh Co., Ltd.) using a modified fuser unit from an imageo MP C5002.

[0396] Specifically, the fixing temperature was varied to measure the temperature at which hot offset occurs (hot offset temperature or fixing upper limit temperature), and this was evaluated based on the following evaluation criteria. The evaluation conditions for the fixing upper limit temperature were a paper feed linear speed of 100 mm / second and a surface pressure of 1.0 kgf / cm². 2 The nip width was set to 7 mm. If the evaluation result was AA, A, or B, the obtained toner was considered to have sufficient hot offset resistance for practical use; if the evaluation result was C, the obtained toner was considered unusable. (Evaluation Criteria) AA: Hot offset temperature is 170°C or higher. A: Hot offset temperature is between 150°C and 170°C. B: Hot offset temperature is between 140°C and 150°C. C: Hot offset temperature is less than 140°C

[0397] [Heat-resistant storage stability] Toner was filled into a glass container for evaluating thermal storage properties and left in a constant temperature bath at 50°C for 24 hours. The toner was then cooled to 24°C, and the penetration rate was measured using a penetration test (JIS K2235-1991). The criteria for determining thermal storage properties based on penetration rate are as follows: If the evaluation result is A or B, the obtained toner is considered to have sufficient heat resistance for practical use; if the evaluation result is C, the obtained toner is considered to be unusable. (Evaluation Criteria) A:25mm or more B: 10mm or more and less than 25mm C: Less than 10mm

[0398] Table 1 shows the evaluation results for the charge amount, low-temperature fixing performance, heat storage performance, hot offset resistance, and blocking resistance of the toners obtained in each example and comparative example.

[0399] [Blocking resistance] A solid 3cm x 15cm rectangular image was printed on Ricoh PPC paper type 6000 <70W> A4 T-grain, with a toner adhesion rate of 0.85 mg / cm². 2 The sheets were formed in this manner, and 200 sheets were printed continuously on one side. The fixing temperature was controlled to be centered around the cold offset temperature + 20°C.

[0400] 200 printed images were stacked and left for one hour. Afterwards, the presence or absence of sticking between the sheets was checked. If sticking occurred, the changes in the images and the sheets after separating them were visually inspected. The results were then evaluated based on the following criteria. If the evaluation result was AA, A, or B, the obtained toner was considered to have sufficient blocking resistance for practical use. If the evaluation result was C, the obtained toner was considered to be unusable. (Evaluation Criteria) AA: The papers do not stick together at all. A: The papers are slightly stuck together, but there are no problems with the image when the papers are separated. B: The papers stick together slightly, and the gloss of the image changes when the papers are separated. C: The papers stick together, and when separated, the images or paper are damaged.

[0401] [Table 1]

[0402] Table 1 shows that the toners of Examples 1 to 5 all met the usage requirements for electrostatic properties, low-temperature fixing properties, heat-resistant storage properties, hot-offset resistance, and blocking resistance, and were confirmed to be practically usable. In contrast, the toners of Comparative Examples 1 to 3 did not meet the usage requirements for electrostatic properties, low-temperature fixing properties, hot-offset resistance, blocking resistance, and heat-resistant storage properties, and were confirmed to have practical problems.

[0403] Therefore, unlike the toners of Comparative Examples 1 to 3, the toners of Examples 1 to 5 contain a crosslinking component, which is a nonlinear polymer containing sulfur elements that branches into three, with metal crosslinking at the ends. By setting the glass transition temperature Tg of the nonlinear polymer to -60°C or higher and less than 0°C, the toners exhibit excellent charge capacity, low-temperature fixing properties, heat resistance, hot offset resistance, and blocking resistance, making them high-quality toners.

[0404] Examples of the present invention are as follows: <1> Resin particles containing at least a binder resin and a coloring agent, It contains tetrahydrofuran insoluble matter, The tetrahydrofuran insoluble component comprises a nonlinear polymer having three or more branched crosslinking components, a sulfur element, and a metal element. The resin particles have a glass transition temperature Tg of -60°C or higher and less than 0°C, as measured by differential scanning calorimetry of the tetrahydrofuran-insoluble component. <2> The aforementioned crosslinking component is formed by bonding at least a sulfonic acid group and a metal ion. <1> These are the resin particles described in [the document]. <3> The aforementioned metal ions include metal ions with a valency of 2 or higher. <2> These are the resin particles described in [the document]. <4> The aforementioned metal ions include two or more types of metal ions. <2> or <3> These are the resin particles described in [the document]. <5> The difference in ionic diameter between the two or more of the aforementioned metal ions is 50 pm or more. <2> from <4> The resin particles are those described in any one of the items. <6> The aforementioned <1> from <5> This toner contains resin particles as described in any one of the following items. <7> The aforementioned <6> This is a developer containing the toner described above. <8> The aforementioned <6> This is a toner storage unit containing the toner described above. <9> Electrostatic latent image carrier, An electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, A developing unit that develops the electrostatic latent image using toner to form a visible image, A transfer unit that transfers the visible image onto a recording medium, The system comprises a fixing unit for fixing the transferred image onto the recording medium, The toner, <6> This is an image forming apparatus that uses the toner described above. <10> The aforementioned <6> A method for manufacturing toner as described above, This method for producing toner involves mixing an oil phase containing a prepolymer, which is a nonlinear reactive precursor, with an aqueous medium, and forming toner matrix particles while generating the nonlinear polymer through at least one of the extension reaction and crosslinking reaction between the prepolymer and metal ions. <11> The aforementioned <6> A method for manufacturing toner as described above, This method for producing toner involves dissolving or dispersing a polyester resin and a prepolymer, which is a nonlinear reactive precursor, in an organic solvent to create an oil phase, then inverting the oil phase to remove the organic solvent, mixing it with a dispersion containing a crystalline polyester resin to prepare a mixed solution, and finally agglomerating the crystalline polyester resin in the mixed solution to form toner matrix particles. <12> An electrostatic latent image is formed on an electrostatic latent image carrier, the electrostatic latent image is developed using toner to form a visible image, the visible image is transferred to a recording medium, the transferred image on the recording medium is fixed, and the toner is <6> This is an image forming method using the toner described above.

[0405] As described above, embodiments have been explained, but these embodiments are presented as examples only, and the present invention is not limited by these embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, and modifications are possible without departing from the spirit of the invention. These embodiments and their variations are included in the scope and spirit of the invention, as well as in the claims of the invention and its equivalents. [Explanation of symbols]

[0406] 1. Image forming process cartridge 100A, 100B, 100C image forming device 10, 11 Electrostatic latent image carrier (photoreceptor drum) 12.52 Corona Charger (Charging Section) 20. Charging roller (charging part) 13.30 Exposure apparatus (exposure section) 14, 40 Developing device (developing section) 50 Intermediate transfer material (intermediate transfer belt) 15, 60 Cleaning device (cleaning section) 16, 70 Transfer roller (transfer section) 80 Static elimination lamp (static elimination unit) 90 Intermediate Transfer Body Cleaning Apparatus 110 Copying device main unit 120 Paper feed table 130 Scanners 140. Automated document transport system 150 Secondary Transfer Device 160 Fixing device (fixing unit) 170 Sheet Reversing Device [Prior art documents] [Patent Documents]

[0407] [Patent Document 1] Japanese Patent Publication No. 2015-125413

Claims

1. Toner resin particles containing at least a binder resin and a colorant, It contains tetrahydrofuran insoluble matter, The tetrahydrofuran-insoluble component comprises a nonlinear polyester having a crosslinked component formed by the bonding of a sulfonic acid group to a metal ion, which is branched into three or more parts. Toner resin particles having a glass transition temperature Tg of the tetrahydrofuran-insoluble component measured by differential scanning calorimetry between -60°C and 0°C.

2. The toner resin particles according to claim 1, wherein the metal ions include metal ions with a valency of 2 or higher.

3. The toner resin particles according to claim 1, wherein the metal ions comprise two or more types of divalent or higher metal ions.

4. The toner resin particles according to claim 3, wherein the difference in ionic diameters of the two or more metal ions is 50 pm or more for each of them.

5. A toner comprising resin particles for toner as described in any one of claims 1 to 4.

6. A developer containing the toner described in claim 5.

7. A toner storage unit containing the toner described in claim 5.

8. Electrostatic latent image carrier, An electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, A developing unit that develops the electrostatic latent image using toner to form a visible image, A transfer unit that transfers the visible image onto a recording medium, The system comprises a fixing unit for fixing the transferred image onto the recording medium, An image forming apparatus in which the toner is the toner described in claim 5.

9. A method for manufacturing toner according to claim 5, A method for producing toner, comprising mixing an oil phase containing a nonlinear reactive precursor with an aqueous medium, and forming toner matrix particles while generating the nonlinear polyester through at least one of an extension reaction and a crosslinking reaction between the reactive precursor and metal ions.

10. A method for manufacturing toner according to claim 5, A method for producing toner, comprising: dissolving or dispersing a polyester resin and a nonlinear reactive precursor in an organic solvent in an oil phase; inverting the oil phase to remove the organic solvent; mixing it with a dispersion containing a crystalline polyester resin to prepare a mixture; and agglomerating the crystalline polyester resin in the mixture to form toner matrix particles.

11. An image forming method comprising forming an electrostatic latent image on an electrostatic latent image carrier, developing the electrostatic latent image using toner to form a visible image, transferring the visible image to a recording medium, fixing the transferred image on the recording medium, wherein the toner is the toner described in claim 5.

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