Resin particles, method for manufacturing resin particles, toner, and image forming apparatus

Abstract

To provide resin particles that have a low environmental impact, yet exhibit excellent electrostatic properties and toner replenishment even when subjected to continuous development stress in high-humidity environments, thereby suppressing carrier contamination. [Solution] A resin particle comprising a matrix particle containing an amorphous resin, a crystalline resin, and polyethylene terephthalate and / or polybutylene terephthalate, to which an external additive containing a plurality of types of silica particles with different volume average particle sizes is added, wherein among the plurality of types of silica particles, silica particle A, which has the largest volume average particle size, is a non-spherical aggregated particle composed of secondary particles formed by the aggregation of a plurality of primary particles, and silica particle B, which has the smallest volume average particle size, is a spherical particle composed of primary particles.

Description

[Technical Field]

[0001] The present invention relates to resin particles, a method for producing resin particles, toner, and an image forming apparatus. [Background technology]

[0002] Resin particles are widely used as toner in image forming devices such as multifunction printers (MFPs) and printers in various locations, including offices. To reduce the environmental impact of toner, various measures are being considered, such as improving the low-temperature fixability of the toner itself to reduce power consumption, reducing energy consumption during manufacturing, using biomass (plant)-derived resins in the binder resin, and using recycled materials in the binder resin. In particular, given the increasing importance of resource conservation, energy conservation, and resource recycling, there is a growing demand for the use of recycled materials in the binder resin.

[0003] When toner particles contain polyethylene terephthalate or polybutylene terephthalate as recycled materials, problems arise such as poor electrostatic properties and high hygroscopicity, leading to a deterioration of image quality when subjected to continuous development stress in high-temperature, high-humidity environments. It is known that these problems can be solved by controlling the particle size distribution and shape of the toner, or by attaching various functional additives to the surface of the toner matrix, thereby controlling the toner's flow stability within a desired range. However, in high-speed machines where the stress on the toner is greater, significant embedding of the additives occurs, leading to the formation of numerous toner aggregates and a deterioration in toner replenishment and waste toner transport.

[0004] To solve the aforementioned problems, for example, Patent Document 1 discloses a toner in which amorphous particles, which are formed by the aggregation of multiple primary particles, are added as an external additive to the surface of toner matrix particles. According to Patent Document 1, by using amorphous particles as an external additive, the release of the external additive from the surface of the toner matrix particles and its embedding into the surface of the toner matrix particles due to stress in the developing machine over time can be relatively suppressed, and the deterioration of toner replenishment and waste toner transportability due to the generation of toner aggregates caused by these factors can be relatively suppressed.

[0005] However, Patent Document 1 does not adequately consider the significant deterioration of toner cohesiveness due to high temperature and high humidity environments. In particular, after prolonged exposure to high temperature and high humidity environments, toner replenishment deteriorates significantly, and waste toner lock occurs. Furthermore, Patent Document 1 does not consider the particle size distribution of amorphous particles or their resistance to cracking under stress. This leads to problems such as deterioration of toner cohesiveness due to small-sized particles or insufficiently coalesced particles contained within amorphous particles, deterioration of toner cohesiveness due to the loss of function of amorphous particles due to cracking of amorphous particles when stress becomes excessive over time, and consequently, a decrease in electrostatic charge and toner replenishment, as well as carrier contamination. [Overview of the project] [Problems that the invention aims to solve]

[0006] The present invention aims to provide resin particles that have a low environmental impact, yet exhibit excellent electrostatic properties and toner replenishment even when subjected to continuous development stress in high-humidity environments, and that can suppress carrier contamination. [Means for solving the problem]

[0007] The resin particles of the present invention, as a means for solving the problem, Resin particles comprising a matrix particle containing an amorphous resin, a crystalline resin, and polyethylene terephthalate and / or polybutylene terephthalate, to which an external additive containing multiple types of silica particles with different volume-average particle sizes is added, Among the aforementioned multiple types of silica particles, silica particle A, which has the largest volume-average particle size, is a non-spherical aggregated particle composed of secondary particles formed by the aggregation of multiple primary particles, while silica particle B, which has the smallest volume-average particle size, is a spherical particle composed of primary particles. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide resin particles that have a low environmental impact, yet exhibit excellent electrostatic properties and toner replenishment even when continuously subjected to development stress in a high-humidity environment, and that can suppress carrier contamination. [Brief explanation of the drawing]

[0009] [Figure 1] Figure 1 is a schematic diagram showing an example of an image forming apparatus according to one embodiment of the present invention. [Modes for carrying out the invention]

[0010] Embodiments of the present invention will be described in detail below. However, the embodiments are not limited by the following description and can be modified as appropriate without departing from the spirit of the invention. Furthermore, in this specification, the "~" indicating a numerical range means that the values ​​before and after it are included as the lower and upper limits, respectively, unless otherwise specified.

[0011] <Resin particles> Resin particles according to one embodiment include a matrix particle comprising an amorphous resin, a crystalline resin, polyethylene terephthalate (PET) and / or polybutylene terephthalate (PBT), and an external additive added to the surface of the matrix particle, and optionally further comprising other components.

[0012] [PET, PBT] The PET and / or PBT contained in the resin particles according to one embodiment have an aromatic ring skeleton, which can improve the strength of the resin particles.

[0013] There are no particular restrictions on PET and / or PBT, and they can be appropriately selected depending on the purpose. For example, recycled materials, off-spec fiber waste, or pellets can be used, but from the standpoint of reducing environmental impact, it is preferable to use recycled materials (hereinafter sometimes referred to as "recycled resin") that have been processed into flake form.

[0014] In one embodiment, the resin particles include PET and / or PBT, which allows for the inclusion of biomass-derived resins instead of petroleum-derived resins, while enhancing environmental compatibility and mitigating the impact of structural differences in biomass-derived resins on the properties of the resin particles.

[0015] There are no particular restrictions on the molecular weight distribution, composition, manufacturing method, or form of use of PET and / or PBT, and they can be appropriately selected according to the purpose.

[0016] There are no particular restrictions on the weight-average molecular weight (Mw) of PET and / or PBT, and it can be appropriately selected depending on the purpose, but 30,000 to 100,000 is preferred.

[0017] The analytical and calculation methods for the PET and / or PBT content in resin particles are not particularly limited, and general methods for calculating the amount of PET can be used. As an analytical and calculation method for the PET or PBT content, for example, the components can be separated from the resin particles by gel permeation chromatography (GPC), and the mass ratio of the constituent components of the resin particles can be calculated by using the analytical methods described below for each separated component.

[0018] Furthermore, quantitative analysis can also be performed by estimating the main components from the soft decomposition of ester bonds in resin particles by methylation using gas chromatography-mass spectrometry (GC / MS) at 300°C with a reaction reagent (10% tetramethylammonium hydroxide (TMAH) / methanol solution), and by drawing a calibration curve of total ion current chromatogram (TICC) intensity.

[0019] Separation of each component by GPC can be carried out, for example, by the following method. In GPC measurement using tetrahydrofuran (THF) as the mobile phase, the eluate is fractionated using a fraction collector or the like, and fractions corresponding to the desired molecular weight portion of the total area integral of the elution curve are collected. After concentrating and drying this collected eluate using an evaporator or the like, the solid content is dissolved in a heavy solvent such as deuterochloroform or deuterated THF, and 1H-NMR measurement is performed. From the integral ratio of each element, the composition monomer ratio of the resin in the eluted component is calculated. As another method, after concentrating the eluate, it is hydrolyzed with sodium hydroxide or the like, and the decomposition products are qualitatively and quantitatively analyzed by high performance liquid chromatography (HPLC) or the like, whereby the composition monomer ratio can also be calculated.

[0020] There is no particular limitation on the total content of PET and PBT, and it can be appropriately selected according to the purpose. However, with respect to 100 parts by mass of the resin particles, 5 to 70 parts by mass is preferable, and 10 to 50 parts by mass is more preferable. If the total content of PET and PBT is 70 parts by mass or less with respect to 100 parts by mass of the resin particles, low-temperature fixing property can be exhibited. If the total content of PET and PBT is 5 parts by mass or more with respect to 100 parts by mass of the resin particles, the effect of reducing the environmental load can be exhibited, and the resin particles can have an excellent particle size distribution. When the total content of PET and PBT is in the more preferable range as described above, it is advantageous in terms of achieving both reduction of the environmental load of the resin particles and improvement of the particle size distribution.

[0021] An example of a separation means for each component contained in resin particles when analyzing the resin particles according to an embodiment is shown in detail. First, 1 g of resin particles is put into 100 mL of THF, and a dissolution solution in which the soluble component is dissolved is obtained while stirring for 30 minutes under the condition of 25°C. The dissolution solution is filtered through a membrane filter with a pore size of 0.2 μm to obtain the THF-soluble component in the resin particles. Next, this is dissolved in THF to prepare a sample for GPC measurement, and is injected into the GPC used for measuring the molecular weight of each of the above resins. On the other hand, a fraction collector is arranged at the eluate discharge port of the GPC, and the eluate is fractionated every predetermined count, and the eluate is obtained every 5% in terms of area ratio from the start of elution (the rise of the curve) of the elution curve. Next, for each elution fraction, 30 mg of the sample is dissolved in 1 mL of deuterated chloroform, and 0.05% by volume of tetramethylsilane (TMS) is added as a reference substance. The solution is filled into a 5 mm diameter glass tube for NMR measurement, and using a nuclear magnetic resonance apparatus (JNM-AL400 manufactured by JEOL Ltd.), integration is performed 128 times at a temperature of 23°C to 25°C to obtain a spectrum. The monomer composition and the composition ratio of the PET resin or the like contained in the resin particles can be determined from the peak integration ratio of the obtained spectrum. Therefore, the resin particles according to an embodiment can reduce the environmental load and can have an excellent particle size distribution.

[0022] [Amorphous resin] The resin particles according to an embodiment contain an amorphous resin. As the amorphous resin, a terpene resin or an amorphous (non-crystalline) polyester resin (hereinafter, also referred to as "amorphous polyester resin B") is preferable, and among them, a linear polyester resin is preferable, and an unmodified polyester resin is preferable. In the present invention, the amorphous resin means those excluding PET and PBT.

[0023] The unmodified polyester resin is a polyester resin obtained by using a polyhydric alcohol and a polyvalent carboxylic acid, a polyvalent carboxylic acid anhydride, a polyvalent carboxylic acid ester or the like, which is a polyvalent carboxylic acid or a derivative thereof, and is a polyester resin not modified with an isocyanate compound or the like.

[0024] The amorphous polyester resin is preferably one that does not contain urethane bonds or urea bonds.

[0025] The amorphous polyester resin contains a dicarboxylic acid component as a constituent, and it is preferable that the dicarboxylic acid component contains 50 mol% or more of terephthalic acid. This is advantageous in terms of heat resistance and storage properties.

[0026] Examples of polyhydric alcohols include diols.

[0027] 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, neopentyl 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 can be used individually or in combination of two or more. Among these, it is preferable that the product contains plant-derived ethylene glycol or propylene glycol.

[0028] Examples of polycarboxylic acids include dicarboxylic acids.

[0029] Examples of dicarboxylic acids include adipic acid, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, maleic acid; succinic acid substituted with C1-C20 alkyl groups or C2-C20 alkenyl groups such as dodecenyl succinic acid and octyl succinic acid; and modified purified rosin. Modified purified rosin modified with acrylic acid, fumaric acid, and maleic acid is preferred.

[0030] Among these, it is preferable to include succinic acid, a saturated aliphatic material derived from plants, and modified purified rosin. Being plant-derived enhances carbon neutrality. Saturated aliphatic materials have the effect of increasing the recrystallization properties of crystalline polyester resins, thereby increasing the aspect ratio of the crystalline polyester resin and improving low-temperature fixability. These can be used individually or in combination of two or more.

[0031] Furthermore, for the purpose of adjusting the acid value and hydroxyl value, amorphous polyester 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.

[0032] Examples of trivalent or higher carboxylic acids include trimellitic acid, pyromellitic acid, or their acid anhydrides.

[0033] Examples of alcohols with a hydride of 3 or higher include glycerin, pentaerythritol, and trimethylolpropane.

[0034] There are no particular restrictions on the molecular weight of the amorphous polyester resin, and it can be appropriately selected depending on the purpose. In gel permeation chromatography (GPC) measurement, the weight-average molecular weight (Mw) is preferably 3,000 to 10,000. The number-average molecular weight (Mn) is preferably 1,000 to 4,000. The ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn), Mw / Mn, is preferably 1.0 to 4.0.

[0035] When the molecular weight is above the lower limit mentioned above, it is possible to suppress a decrease in the heat resistance of the resin particles and their durability against stress such as agitation in the developing machine. When the molecular weight is below the upper limit mentioned above, it is possible to suppress an increase in the viscoelasticity of the resin particles when they melt, and to suppress a decrease in low-temperature fixability.

[0036] The weight-average molecular weight (Mw) is more preferably 4,000 to 7,000. The number-average molecular weight (Mn) is more preferably 1,500 to 3,000. The ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn), Mw / Mn, is more preferably 1.0 to 3.5.

[0037] There are no particular restrictions on the acid value of the amorphous polyester resin, and it can be appropriately selected depending on the purpose. A value of 1 mg KOH / g to 50 mg KOH / g is preferred, and 5 mg KOH / g to 30 mg KOH / g is more preferred. An acid value of 1 mg KOH / g or higher makes the resin particles more likely to become negatively charged, and furthermore, improves the affinity between the paper and the resin particles during fixing to paper, thereby improving low-temperature fixing performance. An acid value of 50 mg KOH / g or lower suppresses a decrease in electrostatic stability, particularly electrostatic stability against environmental fluctuations.

[0038] The hydroxyl value of amorphous polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but it is preferably 5 mg KOH / g or higher.

[0039] The glass transition temperature (Tg) of amorphous polyester resin is preferably 40°C to 80°C, and more preferably 50°C to 70°C. A glass transition temperature (Tg) of 40°C or higher ensures sufficient heat resistance for storage of resin particles and durability against stress such as agitation in the developing machine, as well as good filming resistance. A glass transition temperature (Tg) of 80°C or lower ensures sufficient deformation due to heating and pressurization during fixing of resin particles, resulting in good low-temperature fixing performance.

[0040] The molecular structure of amorphous polyester resins can be determined by NMR measurements in solution or solid state, as well as by X-ray diffraction, GC / MS, LC / MS, and IR measurements. A simpler method is infrared absorption spectroscopy, which can be used to determine the molecular structure at 965±10 cm⁻¹. -1 and 990±10cm -1 One method for detecting amorphous polyester resins is one in which those that do not exhibit absorption based on δCH (out-of-plane angular bending vibration) of olefins are identified.

[0041] The content of amorphous polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but 50 to 90 parts by mass, and more preferably 60 to 80 parts by mass, per 100 parts by mass of resin particles. When the content is 50 parts by mass or more, deterioration of the dispersibility of pigments and release agents in the resin particles can be suppressed, and the occurrence of image fogging and distortion can be suppressed. When the content is 90 parts by mass or less, the content of crystalline polyester resin C and amorphous polyester resin B can be prevented from decreasing, thereby suppressing a decrease in low-temperature fixability. When the content is within the more preferred range described above, it is advantageous in that it is excellent in both high image quality and low-temperature fixability.

[0042] [Prepolymer] In one embodiment, the resin particles may include a polymer (hereinafter also referred to as a prepolymer) having a site that can react with an active hydrogen group-containing compound in order to improve low-temperature fixation.

[0043] Examples of prepolymers include polyesters having groups that can react with active hydrogen groups (hereinafter also referred to as amorphous polyester resin A).

[0044] Examples of groups that can react with active hydrogen groups include isocyanate groups, epoxy groups, carboxylic acids, and acid chloride groups. Among these, isocyanate groups are preferred because they can introduce urethane or urea bonds into amorphous polyester resin A.

[0045] The prepolymer may have a branched structure conferred by at least one of a trivalent or higher alcohol and a trivalent or higher carboxylic acid.

[0046] Examples of polyester resins containing isocyanate groups include reaction products of polyester resins having active hydrogen groups and polyisocyanates.

[0047] Polyester resins having active hydrogen groups can be obtained, for example, by polycondensation of a diol, a dicarboxylic acid, and at least one of a trivalent or higher alcohol and a trivalent or higher carboxylic acid. The trivalent or higher alcohol and the trivalent or higher carboxylic acid impart a branched structure to the polyester resin containing isocyanate groups.

[0048] Examples of diols include aliphatic diols such as ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, 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 polytetramethyl Examples include diols having oxyalkylene groups such as ethylene glycol; alicyclic diols such as 1,4-cyclohexanedimethanol and hydrogenated bisphenol A; alicyclic diols to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide have been added; bisphenols such as bisphenol A, bisphenol F, and bisphenol S; and alkylene oxide adducts of bisphenols to which alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide have been added. Among these, from the viewpoint of controlling the glass transition temperature (Tg) of amorphous polyester resin A to 20°C or lower, it is preferable to use aliphatic diols having 3 to 10 carbon atoms, such as 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 2-methyl-1,3-propanediol, 1,5-pentanediol, and 3-methyl-1,5-pentanediol, and it is more preferable to use 50 mol% or more of the alcohol component in the resin. These diols may be used individually or in combination of two or more.

[0049] Amorphous polyester resin A has steric hindrance in its resin chains, which reduces its melt viscosity during fixing and makes it easier to achieve low-temperature fixing properties. For this reason, it is preferable that the main chain of the aliphatic diol has a structure represented by the following general formula (1).

[0050] [ka] [In the formula, R1 and R2 each independently represent a hydrogen atom and an alkyl group having 1 to 3 carbon atoms. n represents an odd number from 3 to 9. In n repeating units, R1 and R2 may be the same or different.]

[0051] Here, the main chain of an aliphatic diol refers to the carbon chain connecting the two hydroxyl groups of the aliphatic diol in the shortest possible number of carbon atoms. When the number of carbon atoms in the main chain is odd, it is preferable because the crystallinity decreases due to the oddness. Furthermore, when there is at least one alkyl group with 1 to 3 carbon atoms in the side chain, it is even more preferable because the interaction energy between the main chain molecules decreases due to the stericity.

[0052] Examples of dicarboxylic acids include aliphatic dicarboxylic acids such as succinic acid, adipic acid, sebacic acid, dodecanedioic acid, maleic acid, and fumaric acid; and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, and naphthalenedicarboxylic acid. Anhydrides, lower (1-3 carbon atoms) alkyl esters, and halides of these dicarboxylic acids may also be used. Among these, aliphatic dicarboxylic acids with 4 to 12 carbon atoms are preferred from the viewpoint of controlling the glass transition temperature (Tg) of amorphous polyester resin A to 20°C or below, and it is more preferable to use them in amounts of 50% by mass or more of the carboxylic acid component in the resin. These dicarboxylic acids may be used individually or in combination of two or more.

[0053] Examples of trivalent or higher alcohols include trivalent or higher aliphatic alcohols such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol; trivalent or higher polyphenols such as trisphenol PA, phenol novolac, and cresol novolac; and alkylene oxide adducts of trivalent or higher polyphenols, such as those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to trivalent or higher polyphenols.

[0054] Examples of trivalent or higher carboxylic acids include trivalent or higher aromatic carboxylic acids, with trimellitic acid and pyromellitic acid, which have 9 to 20 carbon atoms, being particularly preferred. Alternatively, their anhydrides, lower (1 to 3 carbon atoms) alkyl esters, and halides may also be used.

[0055] Examples of polyisocyanates include diisocyanates and isocyanates with a valency of three or higher. There are no particular restrictions on the polyisocyanate, and it can be appropriately selected depending on the purpose. For example, 1,3- and / or 1,4-phenylenediisocyanate, 2,4- and / or 2,6-tolylenediisocyanate (TDI), crude TDI, 2,4'- and / or 4,4'-diphenylmethane diisocyanate (MDI), crude MDI, crude diaminophenylmethane [a condensation product of formaldehyde and an aromatic amine (aniline) or a mixture thereof; diaminodiphenylmethane and a small amount (e.g., 5-20% by mass) of trifunctional or more] Phosgenes of mixtures with polyamines: Aromatic diisocyanates such as polyallyl polyisocyanate (PAPI), 1,5-naphthylene diisocyanate, 4,4',4"-triphenylmethane triisocyanate, m- and p-isocyanatophenylsulfonyl isocyanates; ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate Aliphatic diisocyanates such as socyanates, lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis(2-isocyanatoethyl) fumarate, bis(2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate; isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis(2-isocyanatoethyl) Examples include alicyclic diisocyanates such as tyl-4-cyclohexene-1,2-dicarboxylate and 2,5- and 2,6-norbornane diisocyanate; aromatic aliphatic diisocyanates such as m- and p-xylylene diisocyanate (XDI) and α,α,α',α'-tetramethylxylylene diisocyanate (TMXDI); polyisocyanates of trivalent or higher valency such as lysine triisocyanate and diisocyanate-modified alcohols of trivalent or higher valency; and modified products of these isocyanates, which may also be mixtures of two or more of these.Examples of modified isocyanates include modified products containing urethane groups, carbodiimide groups, allophanate groups, urea groups, biuret groups, uretodione groups, uretoimine groups, isocyanurate groups, and oxazolidone groups.

[0056] [Crystalline resin] In one embodiment, it is preferable to add a crystalline resin to the resin particles to improve low-temperature fixation.

[0057] 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.

[0058] The polyester resin used in crystalline resins is a crystalline polyester resin (hereinafter sometimes referred to as "crystalline polyester resin C"). The following describes crystalline polyester resin C.

[0059] Crystalline polyester resin C exhibits thermal melting properties that show a rapid change in viscosity near the fixing start temperature due to its high crystallinity.

[0060] By using a crystalline polyester resin C with these properties together with an amorphous polyester resin B, resin particles with good heat resistance and low-temperature fixation properties can be obtained. For example, when used together, the crystalline properties provide good heat resistance until just before the melting temperature, and at the melting temperature, the crystalline polyester resin C undergoes a rapid decrease in viscosity (sharp melt property) due to melting. Consequently, it becomes compatible with the amorphous polyester resin B, and the rapid decrease in viscosity of both allows for good fixation.

[0061] Crystalline polyester resins are obtained from polyhydric alcohols and polyhydric acids or their derivatives, such as polyhydric carboxylic acids, polyhydric carboxylic acid anhydrides, and polyhydric carboxylic acid esters.

[0062] In this embodiment, crystalline polyester resin refers to a 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, as described above. Modified polyester resins, such as prepolymers, and resins obtained by crosslinking and / or stretching the prepolymer are not included in the definition of crystalline polyester resin.

[0063] There are no particular restrictions on polyhydric alcohols, and they can be appropriately selected depending on the purpose. Examples include diols and alcohols with a hydride of three or higher.

[0064] Examples of diols include saturated aliphatic diols. Examples of saturated aliphatic diols include linear saturated aliphatic diols and branched saturated aliphatic diols. Among these, linear saturated aliphatic diols are preferred, and linear saturated aliphatic diols with 2 to 12 carbon atoms are more preferred. If the saturated aliphatic diol is branched, the crystallinity of the crystalline polyester resin may decrease, and the melting point may be lowered. Furthermore, if the number of carbon atoms in the saturated aliphatic diol exceeds 12, it becomes difficult to obtain practical materials.

[0065] Examples of saturated aliphatic diols include ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecanediol, 1,18-octadecanediol, and 1,20-eicosanediol. Among these, ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, and 1,12-dodecanediol are preferred because they provide high crystallinity and excellent sharp-melt properties in the crystalline polyester resin.

[0066] Examples of trivalent or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, and pentaerythritol. These may be used individually or in combination of two or more.

[0067] There are no particular restrictions on polycarboxylic acids, and they can be appropriately selected depending on the purpose. Examples include divalent carboxylic acids and trivalent or higher carboxylic acids.

[0068] From the viewpoint of affinity between paper and resin, the acid value of the crystalline polyester resin is preferably 5 mg KOH / g or higher in order to achieve the desired low-temperature fixation properties. For the production of fine particles by the phase inversion emulsification method, the acid value of the crystalline polyester resin is more preferably 7 mg KOH / g or higher. On the other hand, to improve hot offset properties, the acid value of the crystalline polyester resin is preferably 45 mg KOH / g or lower.

[0069] Furthermore, the hydroxyl value of the crystalline polyester resin is preferably 0 to 50 mg KOH / g, and more preferably 5 to 50 mg KOH / g, in order to achieve the required low-temperature fixability and good electrostatic properties.

[0070] [Biomass-derived resin] In one embodiment, the amorphous resin and / or crystalline resin in the resin particles may include a biomass-derived resin. A biomass-derived resin is a resin that contains plant-derived compounds as raw materials. By adjusting the ratio of petroleum-derived and plant-derived alcohol and acid components, the environmental compatibility ratio and toner quality can be adjusted.

[0071] From the viewpoint of reducing environmental impact, the total content of biomass-derived resin, PET, and PBT is preferably 30% by mass or more, and more preferably 50% by mass or more.

[0072] [External Additives] The resin particles according to one embodiment include multiple types of silica particles with different volume-average particle sizes as external additives added to the surface of the matrix particles, and optionally include other external additives.

[0073] In this invention, among multiple types of silica particles with different volume-average particle sizes contained in the external additive, the silica particle with the largest volume-average particle size is defined as silica particle A, and the silica particle with the smallest volume-average particle size is defined as silica particle B. Silica particle A is a non-spherical aggregated particle composed of secondary particles formed by the aggregation of multiple primary particles. For example, it is a non-spherical aggregated silica (secondary particle) with an average secondary particle size of approximately 100-220 nm, formed by secondary aggregation of primary particles of silica and / or fused silica having an average primary particle size of approximately 20-150 nm. In other words, aggregated silica refers to silica that has been secondary aggregated by chemically bonding primary particles of silica and / or fused silica together using a treatment agent. Silica particle B is a spherical particle composed of primary particles. The following provides a more detailed explanation of primary and secondary particles.

[0074] (primary particle) There are no particular restrictions on the average particle size (Da) of the primary particles, and it can be appropriately selected depending on the purpose, but it is preferably 20 nm to 150 nm, and more preferably 35 nm to 150 nm. When the average particle size (Da) of the primary particles is 20 nm or more, the secondary particles function as a spacer, which can suppress the embedding of the external additive into the toner matrix particles due to external stress. When the average particle size (Da) of the primary particles is 150 nm or less, it can suppress the release of the external additive from the toner, and can also suppress photoreceptor filming.

[0075] The average particle size (Da) of the primary particles can be measured based on the particle size of the primary particles in the secondary particles. The average particle size (Da) of the primary particles can be measured, for example, as follows: First, secondary particles are dispersed in a suitable solvent such as tetrahydrofuran (THF), and then the solvent is removed on a substrate to dry out the sample. Next, the longest length of each aggregated primary particle in the field of view of the obtained sample is measured using a field emission scanning electron microscope (FE-SEM, acceleration voltage: 5kV to 8kV, observation magnification: 8,000x to 10,000x). The number of particles to be measured should be between 100 and 200. The average of the longest lengths of the primary particles of the measured number of particles is calculated and used as the average particle size of the primary particles.

[0076] (Secondary particles) The secondary particles are not particularly limited, and can be appropriately selected depending on the purpose, as long as they are particles obtained by chemically bonding the primary particles with a processing agent described later and then secondary agglomerating them. However, they are preferably obtained by the sol-gel method.

[0077] There are no particular restrictions on the average particle size (Db) of the secondary particles, and it can be appropriately selected depending on the purpose, but it is preferably 80 nm to 200 nm, more preferably 100 nm to 180 nm, and particularly preferably 100 nm to 160 nm. When the average particle size is 80 nm or more, it effectively functions as a spacer and can suppress embedding due to external stress. When the average particle size is 200 nm or less, it suppresses liberation from the toner and also suppresses the adhesion of liberated silica to the photoreceptor, resulting in excellent filming resistance. Furthermore, when the average particle size is 80 nm to 200 nm, it is advantageous in that it suppresses embedding in the toner and improves fluidity and transferability.

[0078] The average particle size (Db) of the secondary particles can be measured, for example, as follows: First, secondary particles are dispersed in a suitable solvent such as tetrahydrofuran (THF), and then the solvent is removed from the substrate to dry out the sample. Next, the longest length of secondary particles in the field of view of the obtained sample is measured using a field emission scanning electron microscope (FE-SEM, acceleration voltage: 5kV to 8kV, observation magnification: 8,000x to 10,000x). The number of particles to be measured should be between 100 and 200. The average longest length of the measured secondary particles is calculated and used as the average particle size of the secondary particles.

[0079] (Degree of adhesion of secondary particles) The degree of adhesion (G) of each secondary particle is expressed as the ratio of the particle size of the secondary particle to the average particle size of the primary particles contained in the secondary particle (particle size of secondary particle / average particle size of primary particle). The particle size of the secondary particle and the average particle size of the primary particle are measured and calculated by the method described above. The degree of adhesion (G) can be arbitrarily controlled by adjusting the primary particle size, the type and amount of the treatment agent described later, and the treatment conditions.

[0080] There are no particular restrictions on the average value of the degree of adhesion (G) of the secondary particles (particle size of secondary particles / average particle size of primary particles), and it can be appropriately selected according to the purpose, but it is preferably 1.5 or more and 4.0 or less, and more preferably 2.0 or more and 3.0 or less. When the average value of the degree of adhesion (G) is 1.5 or more, the external additive is prevented from rolling and becoming embedded in the depressions on the surface of the toner matrix particles, resulting in excellent transferability. When the average value of the degree of adhesion (G) is 4.0 or less, the external additive is prevented from peeling off the toner, thus suppressing charge reduction due to carrier contamination, the occurrence of scratches on the photoreceptor, and image defects over time.

[0081] There are no particular restrictions on the content of secondary particles with an adhesion degree of less than 1.3, and they can be appropriately selected depending on the purpose, but it is preferable that it be 10% or less relative to the secondary particles in the toner.

[0082] The aforementioned secondary particles have a distribution due to the manufacturing process, and particles with a degree of adhesion of less than 1.3 are particles that have not undergone adhesion and exist in a nearly spherical state. Therefore, they are less likely to function as a shape-shifting additive, which is a characteristic feature for preventing embedding.

[0083] The amount of secondary particles with a degree of adhesion of less than 1.3 can be measured by first measuring the particle size of 100 to 200 primary and secondary particles using the method described above, then calculating the degree of adhesion of each secondary particle from the obtained measurement values, and finally dividing the number of particles with a degree of adhesion of less than 1.3 by the number of particles measured.

[0084] (An indicator of the stirring of secondary particles) There are no particular restrictions on the secondary particles, and they can be appropriately selected depending on the purpose. However, it is preferable that they satisfy the following formula (1) in that the cohesive force (adhesion force) between primary particles is maintained even under certain stirring conditions. Nx / 1,000×100≦30%...Formula (1) However, in formula (1) above, Nx represents the number of primary particles in 1,000 particles of the external additive. Nx is measured by stirring 0.5 g of the external additive and 49.5 g of the carrier in a 50 mL bottle with a mixing stirrer at 67 Hz for 10 minutes, and then observing with a scanning electron microscope.

[0085] When the cohesive force of the secondary particles is strong, the number of particles that become primary particles is reduced as the external additives in the toner break or disintegrate due to the load of the developer, etc., suppressing the embedding and rolling of the external additives and maintaining a high transfer rate over time.

[0086] If the cohesive force of the secondary particles is weak (when the proportion of primary particles existing individually exceeds 30% of 1,000 secondary particles), the number of particles that break or disintegrate due to the load of the developer or other equipment in the toner and become primary particles increases, the proportion of spherical primary particles increases, the external additive is more likely to migrate or become embedded, and it becomes difficult to maintain a high transfer rate over time.

[0087] If the primary particles are too small in size (e.g., less than 80 nm), the external additive may easily become embedded in the toner matrix particles and roll into recesses, potentially failing to maintain transferability and chargeability. If the primary particles are too large in size (e.g., more than 200 nm), the external additive may easily detach from the toner, potentially leading to reduced charge due to carrier contamination and damage to the photoreceptor, resulting in image defects over time.

[0088] In formula (1), the primary particles refer to particles that exist individually and are not bonded together after the secondary particles have been stirred using the mixing and stirring machine under the stirring conditions, and include particles that have cracked or disintegrated after stirring and become primary particles, and particles that existed individually as primary particles before stirring, and also include particles that are not bonded together.

[0089] In formula (1) above, there are no particular restrictions on the shape of the primary particles, as long as the particles are not fused together, and they can be appropriately selected according to the purpose, and they often exist in a substantially spherical state.

[0090] In formula (1) above, there are no particular restrictions on the method for confirming the presence of the primary particle, and it can be appropriately selected depending on the purpose. However, a method of confirming the presence of the particle alone by observing it with a scanning electron microscope (SEM) is preferred.

[0091] There are no particular restrictions on the method for measuring the average particle size of the primary particles, and it can be appropriately selected depending on the purpose. However, it is performed by measuring the average particle size of the primary particles in the field of view using a scanning electron microscope (FE-SEM, acceleration voltage: 5kV to 8kV, observation magnification: 8,000x to 10,000x) (number of particles to measure: 100 or more).

[0092] In formula (1) above, in measuring the number of primary particles existing individually relative to 1,000 secondary particles, after stirring, the particles are observed with a scanning electron microscope and counted as one primary particle.

[0093] In formula (1) above, the method for measuring the number of individual primary particles per 1,000 secondary particles can be expressed as, for example, the number of primary particles per 1,000 secondary particles in an observation area when observed with the scanning electron microscope at a particle density and observation magnification in which the contours of each secondary particle and primary particle can be distinguished. The observation area can be appropriately set, for example, any multiple fields or regions of the scanning electron microscope, preferably multiple adjacent fields or regions, such that the number of observed secondary particles is 1,000 or more.

[0094] There are no particular restrictions on the mixing and stirring machine, and it can be appropriately selected according to the purpose, but for example, a rocking mill can be used. Examples of rocking mills include those manufactured by Seiwa Giken Co., Ltd.

[0095] There are no particular restrictions on the carrier, and it can be appropriately selected depending on the purpose, but it is preferable to use coated ferrite powder obtained by applying or drying a coating layer forming solution of acrylic resin and silicone resin containing alumina particles onto the surface of calcined ferrite powder.

[0096] There are no particular restrictions on the 50 mL bottle mentioned above, and it can be appropriately selected depending on the purpose. For example, commercially available glass bottles (manufactured by Nichiden Rika Glass Co., Ltd.) can be used.

[0097] (Particle size distribution index of secondary particles) There are no particular restrictions on the particle size distribution index of the secondary particles, and they can be appropriately selected depending on the purpose, but it is preferable that they satisfy the following formula (2) in particular, as this can solve the problem of cleaning performance in toner. By using particles with a sharp particle size distribution as the secondary particles, as represented by the following formula (2), it is possible to make a toner with particularly excellent cleaning performance. Db50 / Db10≦1.20...Equation (2) However, in formula (2) above, Db50 represents the particle size of the secondary particles at which the cumulative value is 50 percent when the cumulative distribution of the secondary particles is plotted from the small particle side, with the particle size (nm) of the secondary particles on the horizontal axis and the cumulative value (number of particles) of the secondary particles on the vertical axis, and Db10 represents the particle size of the secondary particles at which the cumulative value is 10 percent.

[0098] The aforementioned Db50 is represented, for example, by the cumulative distribution of the secondary particles when the particle size (nm) of the secondary particles is plotted on the horizontal axis and the cumulative value (number of particles %) of the secondary particles is plotted on the vertical axis. If the number of secondary particles measured is 200, it refers to the particle size of the 100th particle, and if it is 150, it refers to the particle size of the 75th secondary particle.

[0099] As a method for measuring Db50, for example, the secondary particles are dispersed in a suitable solvent such as tetrahydrofuran (THF), and the solvent is removed from the substrate to dry the sample. The sample is then measured using a field emission scanning electron microscope (FE-SEM, acceleration voltage: 5kV to 8kV, observation magnification: 8,000x to 10,000x) to measure the particle size of the secondary particles in the field of view, and the particle size of the secondary particles at which the cumulative value reaches 50% is measured. The particle size of the secondary particles can be measured by measuring the longest length of the aggregated secondary particles (number of particles to measure: 100 to 200).

[0100] Db10 is, for example, represented by the cumulative distribution of the secondary particles when the particle size (nm) of the secondary particles is on the horizontal axis and the cumulative value (number of particles %) of the secondary particles is on the vertical axis. If the number of secondary particles measured is 200, it refers to the particle size of the 20th particle, and if it is 150, it refers to the particle size of the 15th particle.

[0101] As a method for measuring Db10, for example, the secondary particles are dispersed in a suitable solvent such as tetrahydrofuran (THF), and the solvent is removed from the substrate to dry the sample. The sample is then measured using a field emission scanning electron microscope (FE-SEM, acceleration voltage: 5kV to 8kV, observation magnification: 8,000x to 10,000x) to measure the particle size of the secondary particles in the field of view, and the particle size of the secondary particles at which the cumulative value reaches 10% is measured. The particle size of the secondary particles can be measured by measuring the longest length of the aggregated particles (number of particles measured: 100 to 200).

[0102] There are no particular restrictions on the "Db50 / Db10" and it can be appropriately selected according to the purpose, but it is preferably 1.00 or more and 1.20 or less, and more preferably 1.00 or more and 1.15 or less. The closer the "Db50 / Db10" is to 1.00, the sharper the shape of the particle size distribution becomes, which is preferable because it reduces the number of uncompounded primary particles and the number of aggregated secondary particles with small particle sizes. When the aforementioned "Db50 / Db10" is 1.20 or less, the particle size distribution of secondary particles does not spread too broadly, and the abundance of small-sized particles can be suppressed. In other words, it means that there are few "small-sized particles A" (particles that have not yet undergone coagulation and exist in the state of primary particles) and few "small-sized particles B" (particles that have undergone coagulation but whose primary particles themselves are small in size). When the amount of the aforementioned "small particle A" is small, it functions as a non-spherical external additive and has excellent resistance to embedding, thus suppressing the occurrence of abnormal images. When there are few of the aforementioned "small-particle B", they function as a spacer, reducing external stress and suppressing the embedding of external additives into the toner matrix particles. There are no particular limitations on the method for reducing the aforementioned "small particle A" and "small particle B," and a suitable method can be selected depending on the purpose. However, a method of removing small particles in advance by classification is preferred.

[0103] (Shape of secondary particles) The shape of the secondary particles is not particularly limited as long as they have a non-spherical shape formed by the adhesion of particles to each other, and can be appropriately selected according to the purpose. For example, a non-spherical shape formed by the adhesion of two or more particles can be used. By using the secondary particles, high toner fluidity is achieved, and even when the toner is subjected to load, such as being agitated in the developer, the embedding and rolling of external additives is suppressed, making it possible to maintain a high transfer rate over time. In addition, the secondary particles maintain their cohesive force (adhesion force) even under certain agitation conditions, resulting in high toner durability.

[0104] There are no particular limitations on the method for confirming that the primary particles are adhering to each other in the secondary particles, and a suitable method can be selected depending on the purpose. However, a method of confirmation by observation with a field emission scanning electron microscope (FE-SEM) is preferred.

[0105] (Method for manufacturing secondary particles) There are no particular limitations on the method for producing the secondary particles, and a suitable method can be selected depending on the purpose. Examples include the sol-gel method and the dry method. Among these, the sol-gel method is preferred. Specifically, a preferred method involves chemically bonding the primary particles with the treatment agent described below by mixing or calcining them to cause secondary aggregation, thereby producing the secondary particles. When synthesizing by the sol-gel method, the treatment agent may be present in the same manner, and the secondary particles may be prepared in a single reaction.

[0106] Secondary particles produced by the sol-gel method are preferable because particle size control is easier than with the dry method, they have a sharp particle size distribution, and they have excellent moisture adsorption properties. Because of the sharp particle size distribution, embedding in the toner due to insufficient particle size and detachment from the toner due to excessive particle size can be suppressed. In addition, secondary particles produced by the sol-gel method are porous, unlike dry silica, and are thought to adsorb moisture, thus reducing the effect of humidity on polyester resin, and are expected to suppress changes in shape and improve storage life.

[0107] There are no particular restrictions on the aforementioned treatment agent, and it can be appropriately selected according to the purpose. Examples include silane-based treatment agents and epoxy-based treatment agents. These may be used individually or in combination of two or more. When the aforementioned silica primary particles are used, the silane-based treatment agent is preferred because the Si-O-Si bonds formed by the silane-based treatment agent are more thermally stable than the Si-OC bonds formed by the epoxy-based treatment agent. In addition, treatment aids (water, 1% by mass aqueous acetic acid solution, etc.) may be used as needed.

[0108] There are no particular restrictions on the silane-based treatment agent, and it can be appropriately selected according to the purpose. For example, alkoxysilanes (tetramethoxysilane, tetraethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, methyldimethoxysilane, methyldiethoxysilane, diphenyldimethoxysilane, isobutyltrimethoxysilane, decyltrimethoxysilane, etc.); silane coupling agents (γ-aminopropyltoluenethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxysilane, etc.) Examples include doxypropylmethyldiethoxysilane, γ-methacroxypropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, vinyltriethoxysilane, methylvinyldimethoxysilane, etc.; vinyltrichlorosilane, dimethyldichlorosilane, methylvinyldichlorosilane, methylphenyldichlorosilane, phenyltrichlorosilane, N,N'-bis(trimethylsilyl)urea, N,O-bis(trimethylsilyl)acetamide, dimethyltrimethylsilylamine, hexamethyldisilazane, and mixtures of cyclic silazanes.

[0109] The silane-based treatment agent causes the primary particles to form chemical bonds and undergo secondary aggregation, as shown below. When the silica primary particles are treated with the alkoxysilanes, silane-based coupling agents, etc., as the silane-based treatment agent, the silanol groups bound to the silica primary particles react with the alkoxy groups bound to the silane-based treatment agent, as shown in formula (A) below, and new Si-O-Si bonds are formed by de-alcoholization, resulting in secondary aggregation. When the silica primary particles are treated with the chlorosilanes as the silane-based treatment agent, the chlorine groups of the chlorosilanes and the silanol groups bound to the silica primary particles undergo a dehydrochlorination reaction, and the silanol groups that form new Si-O-Si bonds undergo a dehydration reaction, forming new Si-O-Si bonds and resulting in secondary aggregation. Furthermore, when the silica primary particles are treated with the chlorosilanes as the silane-based treatment agent, if water is present in the system, the chlorosilanes first hydrolyze into water to generate silanol groups, and these silanol groups and the silanol groups bound to the silica primary particles undergo a dehydration reaction to form new Si-O-Si bonds, resulting in secondary aggregation. When the silica primary particles are treated with silazanes as the silane-based treatment agent, the amino groups and the silanol groups bound to the silica primary particles undergo deammonia, forming new Si-O-Si bonds and resulting in secondary aggregation.

[0110] [ka] However, in formula (A) above, R represents an alkyl group.

[0111] The epoxy treatment agent is not particularly limited and can be appropriately selected depending on the purpose. Examples include bisphenol A type epoxy resin, bisphenol F type epoxy resin, phenol novolac type epoxy resin, cresol novolac type epoxy resin, bisphenol A novolac type epoxy resin, biphenol type epoxy resin, glycidylamine type epoxy resin, and alicyclic epoxy resin.

[0112] The epoxy treatment agent chemically bonds the silica primary particles to form secondary aggregates, as shown in formula (B) below. When the silica primary particles are treated with the epoxy treatment agent, the silanol groups bonded to the silica primary particles add to the epoxy oxygen atoms and carbon atoms bonded to the epoxy groups of the epoxy treatment agent, thereby forming new Si-OC bonds and causing secondary aggregates.

[0113] [ka]

[0114] There are no particular restrictions on the mixing mass ratio (primary particles:treatment agent) of the treatment agent and the primary particles, and it can be appropriately selected depending on the purpose, but 100:0.01 to 100:50 is preferred. Note that the degree of adhesion tends to increase with increasing amounts of the treatment agent.

[0115] There are no particular restrictions on the method of mixing the treatment agent and the primary particles, and a suitable method can be selected depending on the purpose. For example, mixing can be done using a known mixer (such as a spray dryer). When mixing, the primary particles may be prepared first and then mixed with the treatment agent, or the primary particles may be prepared in a single reaction by having the treatment agent present during the preparation of the primary particles.

[0116] There are no particular restrictions on the firing temperature between the treatment agent and the primary particles, and it can be appropriately selected depending on the purpose, but a temperature of 100°C to 2,500°C is preferred. Note that the higher the firing temperature, the higher the degree of adhesion tends to be.

[0117] There are no particular restrictions on the calcination time between the treatment agent and the primary particles, and it can be appropriately selected depending on the purpose, but it is preferably 0.5 hours or more and 30 hours or less.

[0118] There are no particular restrictions on the content of the external additive, and it can be appropriately selected depending on the purpose, but it is preferably 0.5 parts by mass or more and 4.0 parts by mass or less per 100 parts by mass of toner matrix particles, and more preferably 1.0 part by mass or more and 4.0 parts by mass or less. When the content is 0.5 parts by mass or more, the coating rate of the external additive on the matrix particles is high, resulting in excellent fluidity, heat resistance, durability, and cleaning properties. When the content is 4.0 parts by mass or less, the amount of silica released on the photoreceptor can be reduced, and the occurrence of abnormal images can be suppressed.

[0119] (Other external additives) Other external additives that can be used include inorganic fine particles. Inorganic fine particles can be used as appropriate external additives to impart fluidity, developability, electrostatic properties, etc., to toner particles. There are no particular restrictions on such inorganic fine particles, and they can be appropriately selected from known ones depending on the purpose. For example, fine particles made of silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, 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, silicon nitride, etc., can be used. These may be used individually or in combination of two or more.

[0120] (Content of external additives) The content of external additives is preferably 0.01% to 5% by mass of the resin particles, but it is more preferable that the silica release rate Xs, measured by ultrasonic vibration-based free silica measurement, is 35% to 70%. Particles containing PET and / or PBT components may have high charge and high hygroscopicity, which can lead to image quality problems such as reduced particle transportability and cleaning performance. If the silica release rate Xs is below 35%, the overall amount of released silica is very low, making it highly likely that silica is over-embedded, which impairs storage and fluidity. On the other hand, if the silica release rate Xs exceeds 70%, the amount of released silica is too high, making it easy to contaminate carriers and developing rollers during the development process, which can cause a decrease in charge over time and deterioration of image quality.

[0121] [Other ingredients] The resin particles of the present invention may also contain other components such as a mold release agent, a colorant, a charge control agent, a cleaning performance enhancer, and a magnetic material.

[0122] (Release agent) There are no particular restrictions on the release agent (also called wax), and it can be appropriately selected according to the purpose, but a low-melting-point release agent with a melting point of 50°C to 120°C is preferred. The low-melting-point release agent, when dispersed with the resin, effectively acts as a release agent at the interface between the fixing roller and the resin particles, thereby providing good hot offset even in an oil-free (no release agent such as oil is applied to the fixing roller) environment.

[0123] Suitable release agents include, for example, waxes and other similar substances. Examples of waxes and other similar substances include plant-based waxes such as carnauba wax, cotton wax, wood wax, and rice wax; animal-based waxes such as beeswax and lanolin; mineral waxes such as ozokerite and cerucine; and petroleum waxes such as paraffin, microcrystalline, and petrolatum. In addition to these natural waxes, synthetic hydrocarbon waxes such as Fischer-Tropsch wax and polyethylene wax, and synthetic waxes such as esters, ketones, and ethers are also suitable. Furthermore, fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride, and chlorinated hydrocarbons may also 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. These can be used individually or in combination of two or more. From the viewpoint of reducing environmental impact, plant-based waxes are preferred.

[0124] There are no particular restrictions on the melting point of the wax, and it can be appropriately selected depending on the purpose, but 50°C to 120°C is preferred, and 60°C to 90°C is more preferred. If the melting point is 50°C or higher, it is possible to prevent the wax from adversely affecting the heat-resistant storage properties, and if it is 120°C or lower, it is possible to effectively prevent the problem of cold offset occurring during fixing at low temperatures. The melt viscosity of the wax, measured at a temperature 20°C higher than the melting point of the wax, is preferably 5 cps to 1,000 cps, and more preferably 10 cps to 100 cps. If the melt viscosity is 5 cps or higher, it is possible to prevent a decrease in mold release properties, and if it is 1,000 cps or lower, the effects of hot offset resistance and low-temperature fixing properties can be fully exhibited. There are no particular restrictions on the content of the wax in the resin particles, and it can be appropriately selected depending on the purpose, but 0% to 40% by mass is preferred, and 3% to 30% by mass is more preferred.

[0125] (Coloring agent) Known dyes and pigments can be used as colorants, for example, carbon black, nigrosine dye, iron black, naphthol yellow S, Hansa yellow (10G, 5G, G), cadmium yellow, yellow iron oxide, yellow ochre, yellow lead, titanium yellow, polyazo yellow, oil yellow, Hansa yellow (GR, A, RN, R), pigment yellow L, benzidine yellow (G, GR), permanent yellow (NCG), Vulcan fast yellow (5G, R), tartrazine lake, quinoline yellow lake, anthrazan yellow BGL, isoindolinone yellow -, Bengara, Red lead, Red lead, Cadmium red, Cadmium mercury red, Antimony red, Permanent Red 4R, Para red, Faisey 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, Brilliant Carmine 6B, POG Mentoscarlet 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, Malachite Green Lake,Phthalocyanine green, anthraquinone green, titanium dioxide, zinc oxide, lithobone, and mixtures thereof can be used.

[0126] (Static control agent) For the charge control agent, a general charge control agent can be used. Examples of charge control agents include nigrosine-based dyes, triphenylmethane-based dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine-based dyes, alkoxyamines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, elemental or compound phosphorus, elemental or compound tungsten, fluorine-based surfactants, salicylic acid metal salts, and metal salts of salicylic acid derivatives. Specifically, these include Bontron 03 (nigrosine-based dye), Bontron P-51 (quaternary ammonium salt), Bontron S-34 (metal-containing azo dye), E-82 (oxynaphthoic acid-based metal complex), E-84 (salicylic acid-based metal complex), E-89 (phenol-based condensate) (all manufactured by Orient Chemical Industry Co., Ltd.), TP-302 and TP-415 (quaternary ammonium salt molybdenum complexes) (both manufactured by Hodogaya Chemical Co., Ltd.), and Copy Charge PSY (quaternary ammonium salt). Examples include VP2038, the triphenylmethane derivative Copy Blue PR, the quaternary ammonium salt Copy Charge NEGVP2036, Copy Charge NXVP434 (all manufactured by Hoechst), 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. The charge control agent should be used in an amount that exhibits performance without inhibiting fixation, and it is preferable that it be contained in the resin particles at a concentration of 0.5% to 5% by mass, preferably 0.8% to 3% by mass.

[0127] (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 of cleaning agents 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. The polymer fine particles are preferably those with a relatively narrow particle size distribution, and those with a volume average particle size of 0.01 μm to 1 μm are preferred.

[0128] (Magnetic material) There are no particular restrictions on the magnetic material; it can be appropriately selected from known materials depending on the purpose, such as iron powder, magnetite, and ferrite. Among these, white materials are preferred in terms of color.

[0129] <Characteristics of resin particles> [BET specific surface area of ​​the parent particle]

[0130] The BET specific surface area of ​​the matrix particles of the resin particles according to one embodiment is 0.8 m². 2 / g or more 1.4m 2 Preferably less than / g. BET specific surface area is 0.8m². 2 A value of 1.4 m² or higher suppresses the release of external additives. Furthermore, a BET specific surface area of ​​1.4 m² is also present. 2 By keeping the value below / g, it is possible to suppress the deterioration of cohesiveness due to the exposure of parent particles.

[0131] The BET specific surface area of ​​the parent particles of the resin particles according to one embodiment can be measured, for example, using an automatic specific surface area / pore distribution analyzer (device name: TriStar3000, manufactured by Shimadzu Corporation).

[0132] [Particle size] The particle size of the resin particles according to one embodiment is measured using a Coulter Multisizer III (manufactured by Beckman Coulter). The particle size of the resin particles is determined as follows: First, 2 mL of surfactant (sodium dodecylbenzenesulfonate, manufactured by Tokyo Chemical Industry Co., Ltd.) is added as a dispersant to 100 mL of electrolyte. The electrolyte is prepared as an approximately 1% NaCl aqueous solution using primary sodium chloride, and ISOTON-II (manufactured by Beckman Coulter) can be used. To the mixture of electrolyte and surfactant, 10 mg of the sample to be measured is added as solid content to obtain the electrolytic product in which the sample is suspended. The electrolyte in which the sample is suspended is dispersed in an ultrasonic disperser for approximately 1 to 3 minutes, and the volume and number of resin particles are measured using a Coulter Multisizer III with a 100 μm aperture, and the volume distribution and number distribution are calculated. From the obtained distribution, the volume-average particle size (Dv) of the resin particles is determined.

[0133] [Melting point and glass transition temperature (Tg)] The melting point and glass transition temperature (Tg) of resin particles according to one embodiment 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. First, approximately 5.0 mg of the target sample is placed in an aluminum sample container, the sample container is placed on a holder unit, and the container is 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 (first heating). After that, the sample 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). In each of these first and second heating cycles, the DSC curve is measured using a differential scanning calorimeter ("Q-200", manufactured by TA Instruments). 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 determine the glass transition temperature (Tg) of the target sample during the first heating cycle. Similarly, the DSC curve for the second heating cycle can be selected to determine the glass transition temperature (Tg) of the target sample during the second heating cycle.

[0134] Furthermore, using the analysis program in the Q-200 system, the DSC curve obtained can be selected 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 obtained 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.

[0135] Furthermore, in this specification, unless otherwise specified, the glass transition temperature (Tg) and melting point of amorphous polyester resin A, amorphous polyester resin B, crystalline polyester resin C, and other components such as mold release agents shall be the endothermic peak top temperature and glass transition temperature (Tg) at the second heating stage, respectively, as the melting point and glass transition temperature (Tg) of each target sample.

[0136] [Average particle size, average roundness] For measuring the average particle diameter and average circularity, for example, a flow-type particle image analyzer (FPIA-3000, manufactured by Sysmex Corporation) can be used. Specifically, the measurement method involves adding 0.1 ml to 0.5 ml of a surfactant, preferably alkylbenzene sulfonate, as a dispersant to 100 ml to 150 ml of water from which impurities have been removed in a container, and then adding approximately 0.1 g to 0.5 g of the sample to be measured. The suspension containing the dispersed sample is subjected to dispersion treatment in an ultrasonic disperser for approximately 1 to 3 minutes, and the average particle diameter and average circularity are measured using a flow-type particle image analyzer with a dispersion concentration of 3,000 particles / μl to 10,000 particles / μl. However, the particle diameter is defined as the equivalent diameter of a circle, and the average particle diameter is determined by the equivalent diameter of a circle (based on the number of particles). The analysis conditions for the flow-type particle image analyzer are as follows. • Particle size limitation: 0.5 μm ≤ Equivalent circle diameter (based on number of particles) ≤ 200.0 μm • Particle shape limitation: 0.93 < Circularity ≤ 1.00 The mean circularity is defined as follows: (Average circularity) = (Perimeter of a circle equal to the projected area) / (Perimeter of the projected image)

[0137] [Molecular weight] The molecular weight of each component of the resin particles can be measured, for example, by the following method. • Gel permeation chromatography (GPC) measurement device: GPC-8220GPC (manufactured by Tosoh Corporation) • Column: TSKgel SuperHZM-H 15cm 3-row (manufactured by Tosoh Corporation) ·Temperature: 40℃ • Solvent: THF ·Flow rate: 0.35mL / min • Sample: Inject 100 μL of 0.15 mass% of the sample. • Sample pretreatment: Resin particles are dissolved in tetrahydrofuran THF (containing stabilizer, manufactured by Wako Pure Chemical Industries) at a concentration of 0.15% by mass, then filtered through a 0.2 μm filter, and the filtrate is used as the sample. 100 μL of the THF sample solution is injected and measured. For molecular weight measurement of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithm of a calibration curve prepared using several monodisperse polystyrene standard samples and the count. The standard polystyrene samples used for calibration curve preparation are ShowdexSTANDARD Std. Nos. S-7300, S-210, S-390, S-875, S-1980, S-10.9, S-629, S-3.0, and S-0.580, manufactured by Showa Denko. An RI (refractive index) detector is used.

[0138] <Method for manufacturing resin particles> A method for producing resin particles according to one embodiment will be described. The method for producing resin particles according to one embodiment includes an oil phase preparation step, an aqueous phase preparation step, a phase inversion emulsification step, a solvent removal step, an aggregation step, and a fusion step, and further includes other steps such as a shelling step, a washing step, a drying step, an annealing step, and an external additive step as needed.

[0139] (Oil phase preparation process) In the oil phase preparation process, the oil phase is first prepared by dissolving or dispersing the resin (amorphous resin and crystalline resin, etc.), PET or PBT, which are the raw materials for the resin particles, and, if necessary, colorants, prepolymers (precursors of amorphous polyester resin A), wax, and other materials in an organic solvent. Some of the above materials may be added in the aggregation process described later.

[0140] There are no particular restrictions on the method for preparing the oil phase, and it can be appropriately selected depending on the purpose. For example, one method involves gradually adding raw materials such as resins to an organic solvent while stirring, and dissolving or dispersing them.

[0141] For dispersion, known methods can be used, such as dispersers like bead mills and disc mills.

[0142] The raw materials used in the oil phase preparation process can be those described in the section on <Resin Particles> above.

[0143] There are no particular restrictions on the organic solvent, and it can be appropriately selected depending on the purpose, but a volatile solvent with a boiling point of less than 100°C is preferred because it facilitates the subsequent removal of the organic solvent. Examples of such organic solvents include toluene, xylene, benzene, carbon tetrachloride, methylene chloride, 1,2-dichloroethane, 1,1,2-trichloroethane, trichloroethylene, chloroform, monochlorobenzene, dichloroethylidene, methyl acetate, ethyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, methanol, ethanol, and isopropyl alcohol. These may be used individually or in combination of two or more.

[0144] When the resin to be dissolved or dispersed in an organic solvent is a resin having a polyester skeleton, ester-based solvents such as methyl acetate, ethyl acetate, and butyl acetate, or ketone-based solvents such as methyl ethyl ketone and methyl isobutyl ketone are preferred as organic solvents due to their high solubility. Among these, methyl acetate, ethyl acetate, or methyl ethyl ketone are preferred as organic solvents due to their high solvent removal properties.

[0145] There are no particular restrictions on the amount of organic solvent used, and it can be appropriately selected depending on the purpose, but 40 to 300 parts by mass is preferred, 60 to 140 parts by mass is more preferred, and 80 to 120 parts by mass is even more preferred, per 100 parts by mass of the resin particle raw material.

[0146] (Aqueous phase preparation process) In the aqueous phase preparation process, the aqueous phase (aqueous medium) is prepared.

[0147] There are no particular restrictions on the aqueous medium, and it can be appropriately selected from known ones, such as water, a solvent miscible with water, or a mixture thereof. From the viewpoint of granulation, the concentration of the solvent miscible with water is preferably less than or equal to the saturation concentration with respect to the ion-exchanged water used in the phase inversion emulsification process.

[0148] There are no particular restrictions on the solvent that can be miscible with water, and any known solvent can be appropriately selected, such as alcohols, dimethylformamide, tetrahydrofuran, cellulose, lower ketones, or esters. Examples of alcohols include methanol, isopropanol, or ethylene glycol. Examples of lower ketones include acetone or methyl ethyl ketone. Examples of esters include ethyl acetate. These can be used individually or in combination of two or more.

[0149] (Phase inversion emulsification process) In the phase inversion emulsification process, the oil phase obtained in the oil phase preparation process is atomized into fine particles. After neutralizing the oil phase, ion-exchanged water is added to the neutralized oil phase, and a fine particle dispersion is obtained by phase inversion emulsification, which inverts the water-in-oil dispersion into an oil-in-water dispersion.

[0150] Phase inversion emulsification is carried out by uniformly mixing and dispersing the mixture using a stirrer equipped with agitators or a dispersion device.

[0151] There are no particular restrictions on the type of stirring blade, and they can be appropriately selected according to the viscosity of the solution. Examples include low-viscosity stirring blades such as paddles and propellers, medium-viscosity stirring blades such as anchors and Maxblende, and high-viscosity stirring blades such as helical ribbons. Among these, paddles and anchors are preferred because they can control the volume-average particle size of the dispersion (oil droplets) within the preferred range.

[0152] There are no particular limitations on the dispersion device, but examples include ultrasonic dispersers, bead mills, ball mills, roll mills, homomixers, ultramixers, disper mixers, through-type high-pressure dispersers, impact-type high-pressure dispersers, porous high-pressure dispersers, ultra-high-pressure homogenizers, and ultrasonic homogenizers. A stirrer and dispersion device may be used in combination.

[0153] Either a basic inorganic compound or a basic organic compound may be used as the base for neutralizing the oil phase. Examples of basic inorganic compounds include sodium hydroxide, potassium hydroxide, lithium hydroxide, ammonia, sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate, and ammonia. Examples of basic organic compounds include N,N-dimethylethanolamine, N,N-diethylethanolamine, triethanolamine, trippropanolamine, tributanolamine, triethylamine, n-propylamine, n-butylamine, isopropylamine, monomethanolamine, morpholine, methoxypropylamine, pyridine, vinylpyridine, and isophoronediamine.

[0154] When using a stirring blade, there are no particular restrictions on conditions such as rotation speed, stirring time, and stirring temperature, and these can be appropriately selected according to the purpose. There are no particular restrictions on rotational speed, but 100 rpm to 1,000 rpm is preferable, and 200 rpm to 600 rpm is more preferable. The stirring time and stirring temperature are not particularly limited and may be selected arbitrarily as appropriate depending on the purpose.

[0155] Furthermore, a dispersant may be used as needed. 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.

[0156] 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.

[0157] 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.

[0158] (Desolvation process) In the desolvation step, the organic solvent is removed from the obtained fine particle dispersion.

[0159] To remove the organic solvent from the obtained particulate dispersion, one method can be employed in which the entire system is gradually heated while stirring to completely evaporate and remove the organic solvent from the droplets. Alternatively, the obtained particulate dispersion can be sprayed into a dry atmosphere while stirring to completely remove the organic solvent from the droplets. Furthermore, the particulate dispersion may be reduced in pressure while stirring to evaporate and remove the organic solvent. Alternatively, the particulate dispersion may be blown with gas while stirring to evaporate and remove the organic solvent. These methods may be used individually or in combination.

[0160] The drying atmosphere in which the particulate dispersion is sprayed generally consists of heated gases such as air, nitrogen, carbon dioxide, and combustion gases, particularly various gas streams heated to a temperature above the boiling point of the maximum boiling point solvent used. The desired quality can be obtained with short processing times using spray dryers, belt dryers, rotary kilns, etc.

[0161] By removing the organic solvent from the obtained particulate dispersion using the above method, a particulate dispersion liquid can be obtained.

[0162] (Agglutination process) In the agglomeration step, the obtained fine particle dispersion is agglomerated while being stirred until it reaches a desired particle size to obtain agglomerated particles.

[0163] Existing methods such as adding a flocculant and adjusting the pH can be used to induce flocculation. When adding a flocculant, it can be added directly, but it is preferable to use an aqueous solution of the flocculant to avoid localized high concentrations. Furthermore, it is preferable to add the flocculant gradually while observing the particle size of the fine particles.

[0164] The temperature of the dispersion during aggregation is preferably near the glass transition temperature (Tg) of the resin used. If the temperature of the fine particle dispersion is too low, aggregation will not proceed well, resulting in poor efficiency. If the temperature of the fine particle dispersion is too high, the aggregation rate will increase, and the particle size distribution will deteriorate, such as the generation of coarse particles.

[0165] Once the target particle size is reached, aggregation is stopped. Methods to stop aggregation include adding salts or chelating agents with low ionic charge, adjusting the pH, lowering the temperature of the dispersion, or diluting the concentration by adding a large amount of aqueous medium.

[0166] By the above method, a dispersion of resin particles can be obtained.

[0167] In the agglomeration process, colorants, crystalline resins, and release agents may be added. In this case, by dispersing the materials in an aqueous medium or by mixing them with the aforementioned fine particle dispersion and then agglomerating them, agglomerated particles in which the colorant, crystalline resin, and release agent are uniformly dispersed can be obtained.

[0168] In this embodiment, it is preferable to use a metal salt of Na with a low ionic charge. By replacing Na with the metal used as a flocculant, flocculation can be stopped efficiently.

[0169] As a coagulant, a general-purpose coagulant can be used. The coagulant may be used alone or in combination of two or more types.

[0170] Metal ions function as crosslinking agents, causing the edges of the resin to crosslink. For example, metal salts of monovalent metals such as sodium and potassium, metal salts of divalent metals such as calcium and magnesium, and metal salts of trivalent metals such as iron and aluminum can be used. In this embodiment, in order to obtain resin particles with a good particle size distribution, it is preferable to use a metal salt of a divalent metal, and a metal salt of magnesium is particularly preferred.

[0171] If metals used as flocculants remain in the resin particles, they worsen the electrostatic properties. Therefore, the amount of metal elements in the resin particles is preferably 0.05% to 1% by mass. If the amount of elements in the resin particles is 0.05% by mass or more, there is a sufficient amount of metal used during flocculation, resulting in sufficient flocculation force and suppression of deterioration of particle size distribution. If the amount of elements in the resin particles is 1% by mass or less, electrostatic properties can be maintained. The type and amount of metal in the resin particles can be adjusted by the type and amount of flocculants and inhibitors, and the washing conditions in the washing process.

[0172] (fusion process) In the fusion process, the obtained aggregated particles are fused together by heat treatment to reduce irregularities and create a spherical shape. Fusion can be achieved by heating the dispersion of aggregated particles while stirring. The temperature of the liquid is preferably near the temperature exceeding the glass transition temperature (Tg) of the resin being used.

[0173] (Shelling process) Furthermore, shelling may be performed as needed (shelling step). In the shelling step, a shell layer is formed on the spheroidized particles obtained in the fusion step.

[0174] There are no particular restrictions on the method for forming the shell layer, and it can be appropriately selected depending on the purpose. For example, one method for forming the shell layer is to first produce spherical particles of the desired particle size in a fusion process, then add an amorphous resin, and repeat the aggregation and fusion processes to form the shell layer.

[0175] (Washing and drying process) In the washing and drying process, only the resin particles are removed from the resin particle dispersion obtained by the above method, washed, and dried.

[0176] The resin particle dispersion obtained by the above method contains auxiliary materials such as agglutinating salts in addition to resin particles, so washing is performed to separate only the resin particles from the dispersion. Methods for washing the resin particles include, but are not limited to, centrifugal separation, vacuum filtration, and filter pressing. A resin particle cake can be obtained by any of these methods, but if the cake cannot be sufficiently washed in one operation, the obtained cake may be dispersed again in an aqueous solvent to form a slurry, and the process of separating the resin particles by one of the above methods may be repeated. Alternatively, if washing is performed by vacuum filtration or filter pressing, a method may be adopted in which the aqueous solvent is passed through the cake to wash away the auxiliary materials that have been absorbed by the colored resin particles. The aqueous solvent used for this washing is water, or a mixed solvent of water and an alcohol such as methanol or ethanol, but it is preferable to use water from the standpoint of cost and environmental burden due to wastewater treatment, etc.

[0177] Since the washed resin particles contain a large amount of water-based media, removing the water-based media through drying will allow you to obtain only the resin particles.

[0178] For drying, various types of dryers can be used, including spray dryers, vacuum freeze dryers, reduced pressure dryers, stationary shelf dryers, mobile shelf dryers, fluidized bed dryers, rotary dryers, and agitated dryers. It is preferable to dry the resin particles until the final moisture content is less than 1%. If the colored resin particles after drying are soft and aggregated, causing problems during use, they may be crushed using equipment such as a jet mill, Henschel mixer, super mixer, coffee mill, Auster blender, or food processor to break up the aggregates.

[0179] (Annealing process) In the annealing process, when a crystalline resin is added, performing the annealing treatment after drying causes phase separation between the amorphous and crystalline resins, improving adhesion. Specifically, storage at a temperature near the glass transition temperature (Tg) for 10 hours or more is sufficient.

[0180] (External addition process) In the external additive process, an external additive containing multiple types of silica particles with different volume-average particle sizes is added to the obtained resin particles (matrix particles). In addition, to give the resin particles fluidity, electrostatic properties, cleaning properties, etc., other components such as wax, colorants, electrostatic control agents, and cleaning property enhancers may be added and mixed.

[0181] Specific mixing methods include applying impact force to the mixture using high-speed rotating blades, and introducing the mixture into a high-speed airflow to accelerate it and causing the particles, or composite particles, to collide with a suitable impact plate.

[0182] Examples of equipment 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 Co., Ltd.), a cryptron system (manufactured by Kawasaki Heavy Industries Co., Ltd.), and an automatic mortar and pestle.

[0183] <Toner> A toner according to one embodiment may contain resin particles according to one embodiment, or may consist of resin particles according to one embodiment. By using resin particles according to one embodiment in toner, the environmental impact can be reduced, and even when using plant-derived resin, it is possible to provide images with excellent low-temperature fixability and electrostatic properties, as well as superior image quality.

[0184] <Developer> A developer containing toner according to one embodiment may optionally contain other components such as carriers, as appropriate. This allows for excellent transferability, electrostatic properties, and stable formation of high-quality images.

[0185] 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.

[0186] When toner according to one embodiment is used in a one-component developer, even when toner is replenished, fluctuations in toner particle size are small, toner filming onto the developing roller and toner fusion onto components such as blades that thin the toner layer are minimized, and high-quality images can be obtained in the developing device.

[0187] 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 toner according to one embodiment is used in 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.

[0188] 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.

[0189] A developer containing toner 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.

[0190] [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.

[0191] (Core material) There are no particular restrictions on the core material, and it can be appropriately selected according to the purpose. Examples include manganese-strontium materials with a magnetization of 50 emu / g to 90 emu / g, and manganese-magnesium materials with a magnetization of 50 emu / g to 90 emu / g. In order to ensure image density, it is preferable to use highly magnetized materials such as iron powder of 100 emu / g or more, or magnetite with a magnetization of 75 emu / g to 120 emu / g. Furthermore, it is preferable to use low magnetized materials such as copper-zinc materials with a magnetization of 30 emu / g to 80 emu / g, as this can mitigate the impact of the developer in a slushy state on the photoreceptor and is advantageous for improving image quality. These may be used individually or in combination of two or more types.

[0192] The volume-average particle size of the core material is not particularly limited and can be appropriately selected depending on the purpose, but 10 μm to 150 μm is preferred, and 40 μm to 100 μm is more preferred. If the volume-average particle size is 10 μm or more, the problem of a large amount of fine powder in the carrier, which can reduce the magnetization per particle and cause carrier scattering can be effectively prevented. On the other hand, if it is 150 μm or less, the specific surface area decreases, which can cause toner scattering, and in full-color printing with many solid areas, this can effectively prevent the problem of poor reproduction of solid areas in particular.

[0193] (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.

[0194] The average thickness of the resin layer is preferably 0.05 to 0.50 μm.

[0195] <Developer container> The developer container is a container for containing a developer including toner according to one embodiment. The developer container is not particularly limited and can be appropriately selected from known types, but examples include those having a container body and a cap.

[0196] Furthermore, the size, shape, structure, and material of the container body are not particularly limited, but the shape is preferably cylindrical, with spiral-shaped irregularities formed on the inner surface, allowing the developer contents to move towards the discharge port by rotation, and it is particularly preferable that some or all of the spiral-shaped irregularities have a bellows function. In addition, the material is not particularly limited, but it is preferable that it has good dimensional accuracy, and examples of resin materials include polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, polyacrylic acid, polycarbonate resin, ABS resin, and polyacetal resin.

[0197] The developer container is easy to store and transport, and offers excellent handling, so it can be detachably attached to the image forming apparatus, process cartridge, etc., described later, and used for replenishing the developer.

[0198] <Toner storage unit> A toner storage unit 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 toner storage unit include a toner storage container, a developer, and a process cartridge.

[0199] A toner container refers to a container that holds toner.

[0200] A developing unit refers to a device that has the means to store toner and develop it.

[0201] A process cartridge is defined as an integrated device comprising at least an electrostatic latent image carrier (also called an image carrier) and a developing means, containing toner, and being 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.

[0202] The toner storage unit contains toner according to one embodiment. By mounting the toner storage unit in an image forming apparatus and performing image formation, image formation is carried out using the toner according to one embodiment. As a result, the environmental impact is reduced, and even when using plant-derived resin, it is possible to provide images with excellent low-temperature fixability and electrostatic properties, as well as superior image quality.

[0203] <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.

[0204] 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 the toner image to a recording medium and a fixing unit for fixing the transferred image on the surface of the recording medium.

[0205] In the developing unit, 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.

[0206] (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.

[0207] 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.

[0208] (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.

[0209] 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.

[0210] 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.

[0211] 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.

[0212] 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.

[0213] 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.

[0214] 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.

[0215] 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.

[0216] Furthermore, the exposure unit may employ a back-facing method that exposes the electrostatic latent image carrier in an image-like manner from the back side.

[0217] (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.

[0218] The developing unit may be a single-color developing unit or a multi-color developing unit. Suitable developing devices include, for example, a developing apparatus that has an agitator that frictionally agitates and charges the toner, a magnetic field generating unit fixed inside, and a rotatable developer carrier (e.g., a magnetic roller) on its surface that carries a developer containing toner.

[0219] (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.

[0220] The transfer section (primary transfer means and secondary transfer section) preferably includes at least a transfer device that exfoliates and charges the visible image formed on the electrostatic latent image carrier (photoreceptor) toward the recording medium. There may be one transfer section or two or more.

[0221] Examples of transfer devices include corona discharge transfer devices, transfer belts, transfer rollers, pressure transfer rollers, and adhesive transfer devices.

[0222] While plain paper is typically used as the recording medium, there are no particular restrictions as long as it is capable of transferring the unfixed image after development. Any known recording medium (recording paper) can be appropriately selected according to the purpose, and PET bases for OHPs can also be used.

[0223] (Fixing part) The fixing section is not particularly limited and can be appropriately selected according to the purpose, but a known heating and pressing section is preferred. Examples of heating and pressing sections include a combination of a heating roller and a pressing roller, and a combination of a heating roller, a pressing roller and an endless belt.

[0224] Preferably, the fixing section is a heating and pressing section that includes a heating element equipped with a heating element, a film in contact with the heating element, and a pressing member that presses against the heating element via the film, and can heat and fix a recording medium on which an unfixed image has been formed between the film and the pressing member.

[0225] The heating temperature in the heating and pressurizing section is usually preferably between 80°C and 200°C.

[0226] There are no particular restrictions on the surface pressure in the heating and pressurizing section, and it can be appropriately selected according to the purpose, but 10 N / cm is recommended. 2 ~80 N / cm 2 It is preferable that this be the case.

[0227] In this embodiment, depending on the purpose, a known optical fuser may be used together with or in place of the fuser unit.

[0228] (others) The image forming apparatus relating to the primary form may also include, for example, a static elimination unit, a recycling unit, a control unit, and the like.

[0229] ((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.

[0230] ((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.

[0231] The primary image forming apparatus can improve cleaning performance by having a cleaning section. Specifically, by controlling the adhesion force between toners, the fluidity of the toner can be controlled, thereby improving cleaning performance. Furthermore, by controlling the characteristics of the toner after degradation, excellent cleaning quality can be maintained even under harsh conditions such as extended lifespan and high temperature and humidity. In addition, since the external additive can be sufficiently released from the toner on the photoreceptor, a deposit layer (dam layer) of the external additive can be formed in the cleaning blade nip section, thereby achieving high cleaning performance.

[0232] ((Recycling Department)) The recycling department is not particularly restricted and can use known means of transport, etc.

[0233] ((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.

[0234] The image forming apparatus according to one embodiment can perform image formation using the toner according to one embodiment, thereby reducing environmental impact, and even when using plant-derived resin, it can provide images with excellent low-temperature fixability and electrostatic properties, as well as superior image quality.

[0235] <Image forming method> An image forming method using toner according to one embodiment includes an electrostatic latent image formation step of forming an electrostatic latent image on an electrostatic latent image carrier, and a development step of developing the electrostatic latent image using toner to form a toner image, and may further include other steps as necessary. The image forming method can be suitably carried out by the image forming apparatus, the electrostatic latent image formation step can be suitably carried out by the electrostatic latent image formation unit, the development step can be suitably carried out by the development unit, and the other steps can be suitably carried out by the other unit.

[0236] Furthermore, an image forming method using toner according to one embodiment more preferably includes, in addition to the electrostatic latent image formation step and development step described above, a transfer step of transferring the toner image to a recording medium and a fixing step of fixing the transferred image on the surface of the recording medium.

[0237] 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.

[0238] The electrostatic latent image formation process is a process of forming an electrostatic latent image on an electrostatic latent image carrier, and includes a charging step of charging the surface of the electrostatic latent image carrier and an exposure step of exposing the charged surface of the electrostatic latent image carrier to form an electrostatic latent image. Charging can be performed, for example, by applying a voltage to the surface of the electrostatic latent image carrier using a charger. Exposure can be performed, for example, by exposing the surface of the electrostatic latent image carrier in an image-like manner using the exposure unit. Formation of the electrostatic latent image can be performed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then exposing it in an image-like manner, and can be performed by an electrostatic latent image formation unit.

[0239] 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 performed, for example, by developing the electrostatic latent image using the toners, and this can be done using a developing unit.

[0240] 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, which 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.

[0241] The transfer process is a process of transferring a visible image to a recording medium. Preferably, the transfer process involves using an intermediate transfer medium to transfer the visible image onto the intermediate transfer medium, followed by a secondary transfer of the visible image onto the recording medium. More preferably, the transfer process includes a primary transfer process using two or more toners, preferably full-color toners, to transfer the visible image onto an intermediate transfer medium to form a composite transfer image, and a secondary transfer process to transfer the composite transfer image onto the recording medium. The transfer can be performed, for example, by charging an electrostatic latent image carrier (photoreceptor) with a transfer charger, and can be carried out by a transfer unit.

[0242] 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 has been transferred to the recording medium, or it may be performed simultaneously for each color developer in a stacked state.

[0243] An image forming method using toner according to one embodiment may further include other steps as appropriate, such as a static elimination step, a cleaning step, a recycling step, etc.

[0244] 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.

[0245] The cleaning process is a process of removing the toner remaining on the electrostatic latent image carrier, and can be suitably performed by the cleaning unit.

[0246] 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.

[0247] An image forming method using toner according to one embodiment reduces environmental impact, and even when using plant-derived resin, it can provide images with excellent low-temperature fixability and electrostatic properties, as well as superior image quality.

[0248] Here, the image forming apparatus according to the present invention will be described with reference to the drawings. It should be noted that the present invention is not limited to the embodiments shown below, and can be modified, added, modified, or deleted to the extent that a person skilled in the art can conceive of it. Any embodiment that achieves the function and effects of the present invention is included within the scope of the present invention.

[0249] One embodiment of a method for forming an image using the image forming apparatus of the present invention will be described with reference to Figure 1. While a printer is shown as an example of the image forming apparatus in this embodiment, the image forming apparatus of the present invention is not particularly limited as long as it is capable of forming an image using toner from a copier, facsimile, multifunction device, etc.

[0250] Figure 1 is a schematic diagram showing an example of an image forming apparatus according to one embodiment of the present invention. The image forming apparatus 200 includes a paper feeding unit 210, a transport unit 220, an image forming unit 230, a transfer unit 240, and a fuser 250.

[0251] The paper feeding unit 210 includes a paper feed cassette 211 on which the paper to be fed P is stacked, and a paper feed roller 212 that feeds the paper P from the paper feed cassette 211 one sheet at a time.

[0252] The conveying unit 220 includes a roller 221 that conveys the paper P fed by the paper feed roller 212 in the direction of the transfer unit 240, a pair of timing rollers 222 that sandwich and wait for the leading end of the paper P conveyed by the roller 221, and send the paper to the transfer unit 240 at a predetermined timing, and a paper discharge roller 223 that discharges the paper P on which the color toner image is fixed to the paper discharge tray 224.

[0253] The image forming unit 230 includes, at predetermined intervals, an image forming unit 180Y that forms an image using a developer having yellow toner, an image forming unit 180C that uses a developer having cyan toner, an image forming unit 180M that uses a developer having magenta toner, an image forming unit 180K that uses a developer having black toner, and an exposure device 233, in order from left to right in FIG. 1.

[0254] The image forming unit 180 (180Y, 180C, 180M, 180K) is provided rotatable clockwise in FIG. 1, and includes a photosensitive drum 231 (231Y, 231C, 231M, 231K) on which an electrostatic latent image and a toner image are formed, a charger 232 (232Y, 232C, 232M, 232K) that uniformly charges the surface of the photosensitive drum 231 (231Y, 231C, 231M, 231K), and a cleaner 236 (236Y, 236C, 236M, 236K) that removes the toner remaining on the surface of the photosensitive drum 231 (231Y, 231C, 231M, 231K).

[0255] The image forming unit 180 (180Y, 180C, 180M, 180K) includes a toner bottle 234 (234Y, 234C, 234M, 234K) that stores toner of each color, and a sub hopper 160 (160Y, 160C, 160M, 160K) for replenishing the toner supplied from the toner bottle 234 (234Y, 234C, 234M, 234K).

[0256] In addition, when indicating an arbitrary image forming unit among the image forming units 180 (180Y, 180C, 180M, 180K), it is referred to as an image forming unit.

[0257] The exposure unit 233 reflects the laser light L emitted from the light source 233a based on image information using polygon mirrors 233b (233bY, 233bC, 233bM, 233bK) which are rotated by a motor, and irradiates the photoreceptor drum 231 with the resulting light.

[0258] Furthermore, the developer contains toner and carrier. The four image forming units 180 (180Y, 180C, 180M, 180K) are substantially identical in their mechanical configuration, differing only in the developer they use.

[0259] The transfer unit 240 includes a drive roller 241 and a driven roller 242, an intermediate transfer belt 243 that can rotate counterclockwise in Figure 1 in conjunction with the drive roller 241, primary transfer rollers 244 (244Y, 244C, 244M, 244K) positioned opposite the photoreceptor drum 231 (231Y, 231C, 231M, 231K) on either side of the intermediate transfer belt 243, and secondary opposing rollers 245 and 246 positioned opposite the intermediate transfer belt 243 at the transfer position of the toner image to the paper.

[0260] The fuser unit 250 has a heater inside and is equipped with a pressure roller 252 that rotatably applies pressure to the fuser belt 251, which heats the paper P, to form a nip. As a result, heat and pressure are applied to the color toner image on the paper P, and the color toner image is fixed.

[0261] The paper P on which the color toner image has been fixed is ejected to the paper output tray 224 by the paper output roller 223, completing the image formation process. [Examples]

[0262] 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.

[0263] <Synthesis of Ketimin> In a reaction vessel equipped with a stirring rod and thermometer, 170 parts of isophorone diamine and 75 parts of methyl ethyl ketone were charged, and the reaction was carried out at 50°C for 5 hours to obtain [Ketimine Compound 1]. The amine value of [Ketimine Compound 1] was 418.

[0264] <Synthesis of amorphous polyester resin A-1> -Synthesis of Prepolymer A-1- In a reaction vessel equipped with a condenser, stirrer, and nitrogen inlet, 3-methyl-1,5-pentanediol, isophthalic acid, and plant-derived sebacic acid were added together with titanium tetraisopropoxide (1,000 ppm relative to the resin component) such that the molar ratio of hydroxyl groups to carboxyl groups (OH / COOH) was 1.1, the diol component consisted of 100 mol% 3-methyl-1,5-pentanediol, the dicarboxylic acid component consisted of 73 mol% isophthalic acid and 23 mol% sebacic acid, and the amount of trimethylolpropane in the total monomer was 1.5 mol%. The mixture was then heated to 200°C over approximately 4 hours, and then to 230°C over 2 hours, and the reaction was carried out until no more effluent was released. The mixture was then further reacted under reduced pressure of 10 mmHg to 15 mmHg for 5 hours to obtain [Intermediate Polyester A-1]. Next, the obtained [intermediate polyester A-1] and isophorone diisocyanate (IPDI) were added to a reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet tube in a molar ratio (isocyanate groups of IPDI / hydroxyl groups of intermediate polyester) of 2.0. After diluting with ethyl acetate to a 50% ethyl acetate solution, the mixture was reacted at 150°C for 4 hours to obtain [prepolymer A-1].

[0265] -Synthesis of amorphous polyester resin A-1- The obtained [prepolymer A-1] was stirred in a reaction vessel equipped with a heater, stirrer, and nitrogen inlet tube. Then, [ketimine compound 1] was added dropwise to the reaction vessel in an amount that was equimolar to the amount of isocyanate in [prepolymer A-1]. After stirring at 45°C for 10 hours, the prepolymer extension was removed. The obtained prepolymer extension was dried under reduced pressure at 50°C until the amount of residual ethyl acetate was 100 ppm or less to obtain [amorphous polyester resin A-1]. The glass transition temperature (Tg) of the obtained [amorphous polyester resin A-1] was -51°C, and the weight-average molecular weight (Mw) was 17000.

[0266] <Synthesis of amorphous polyester resin B-1> In a four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple, bisphenol A ethylene oxide 2 molar adduct, bisphenol A propylene oxide 2 molar adduct, terephthalic acid, and adipic acid were added, with the molar ratio of bisphenol A propylene oxide 2 molar adduct to bisphenol A ethylene oxide 2 molar adduct being 60 / 40 (bisphenol A propylene oxide 2 molar adduct / bisphenol A ethylene oxide 2 molar adduct), and terephthalic acid and adipic acid. The terephthalic acid and adipic acid were charged in a molar ratio (terephthalic acid / adipic acid) of 97 / 3, and the molar ratio of hydroxyl groups to carboxyl groups (OH / COOH) was 1.3. This mixture was reacted with titanium tetraisopropoxide (500 ppm relative to the resin components) at atmospheric pressure and 230°C for 8 hours, followed by a further reaction under reduced pressure of 10 mmHg to 15 mmHg for 4 hours. Then, trimellitic anhydride was added to the reaction vessel at a concentration of 1 mol% relative to the total resin components, and the mixture was reacted at 180°C and atmospheric pressure for 4 hours to obtain [amorphous polyester resin B-1]. The glass transition temperature (Tg) of the obtained [amorphous polyester resin B-1] was 65°C, and the weight-average molecular weight (Mw) was 9000.

[0267] <Synthesis of crystalline polyester resin C-1> A 5 L four-neck flask equipped with a nitrogen inlet tube, a dehydrating tube, a stirrer, and a thermocouple was charged with sebacic acid and ethylene glycol such that the molar ratio of the hydroxyl group to the carboxyl group, OH / COOH, was 0.9. Together with titanium tetraisopropoxide (500 ppm with respect to the resin component), the mixture was reacted at 180 °C for 10 hours, then the temperature was raised to 200 °C and reacted for 3 hours, and further reacted at a pressure of 8.3 kPa for 2 hours to obtain [Crystalline polyester resin C-1]. The melting point of the obtained [Crystalline polyester resin C-1] was 72 °C, and the weight-average molecular weight (Mw) was 20,000.

[0268] <Production of Crystalline Polyester Resin Dispersion C-1> A container equipped with a stirring rod and a thermometer was charged with 45 parts by mass of [Crystalline polyester resin C-1] and 450 parts by mass of ethyl acetate. The temperature was raised to 80 °C under stirring and held at 80 °C for 5 hours, then cooled to 30 °C in 1 hour. Using a bead mill (Ultraviscomill, manufactured by Imex Co., Ltd.), dispersion was carried out under the conditions of a liquid feed rate of 1 kg / hr, a disk peripheral speed of 6 m / sec, 80% by volume filling of zirconia beads with a diameter of 0.5 mm, and 3 passes to obtain [Crystalline polyester resin dispersion C-1]. The volume-average particle diameter of the obtained crystalline polyester resin particles was 450 nm, and the solid content concentration of the resin particles was 10%.

[0269] <Preparation of WAX Dispersion 1> 180 parts by mass of ester wax (manufactured by NOF Corporation, WE-11, a synthetic wax derived from plant monomers, melting point 67 °C) and 17 parts by mass of an anionic surfactant (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Neogen SC, sodium dodecylbenzenesulfonate) as a surfactant were added to 720 parts by mass of ion-exchanged water. This was heated to 90 °C and dispersed using a homogenizer to obtain [WAX Dispersion 1]. The volume-average particle diameter of the wax particles contained in the obtained [WAX Dispersion 1] was 300 nm, and the solid content concentration of the resin particles was 25%.

[0270] <Preparation of Master Batch (MB) 1> 1200 parts by mass of water, 500 parts by mass of carbon black (Printex 35, manufactured by Degussa) [DBP oil absorption = 42 mL / 100 mg, pH = 9.5], and 500 parts by mass of [amorphous polyester resin B-1] were added and mixed with a Henschel mixer (manufactured by Nippon Coke & Engineering Co., Ltd.). The mixture was kneaded at 150 °C for 30 minutes with two rolls, then rolled and cooled and pulverized with a pelletizer to obtain [masterbatch 1].

[0271] <Manufacture of External Additives 1 and 2> The manufacture of External Additives 1 and 2 was carried out by mixing primary particles of silica having various average particle diameters and a treating agent with a spray dryer and firing them under the conditions shown in Table 1-1 to agglomerate the primary particles to produce agglomerated particles (secondary particles). Then, in order to obtain a sharp particle size distribution, a classification treatment was performed with a classifier. The treating agent was prepared by adding 0.1 part by mass of a treatment aid (water or 1 mass% acetic acid aqueous solution) to 1 part by mass of methyltrimethoxysilane. The average particle diameter, shape, etc. of the secondary particles produced by agglomerating the primary particles are shown in Table 1-1 and Table 1-2.

[0272] <Evaluation of External Additives 1 and 2> [Particle Diameter and Particle Size Distribution] For the agglomerated particles (secondary particles), Db50 was determined by measuring the particle diameter of the agglomerated particles and obtaining the particle diameter at which the cumulative value became 50% by number when drawing a cumulative distribution from the small particle side. Db10 was determined by measuring the particle diameter of the agglomerated particles and obtaining the particle diameter at which the cumulative value became 10% by number when drawing a cumulative distribution from the small particle side. The number average particle diameter (Db) of the agglomerated particles (secondary particles) was measured by measuring the longest length of the aggregated particles (number of particles measured: 150), and the number average particle diameter (Da) of the primary particles of the agglomerated particles was predicted from the overall image from the outer frame of the silica being agglomerated, and the average value of the longest length of the overall image was measured (number of particles measured: 150). The particle size of each of these particles was measured by dispersing the cemented particles in a suitable solvent (such as tetrahydrofuran (THF)), removing the solvent from the substrate, and then measuring the particle size in the field of view of the sample obtained by drying.

[0273] [Coalescence degree] The degree of adhesion was calculated by determining the number-average particle size (Db) of a single adherent particle (secondary particle) and the number-average particle size (Da) of the multiple primary particles constituting that adherent particle, in the measurement of the primary and secondary particle sizes of the adherent particles, and using the following formula. Degree of adhesion (Db / Da) = Number-average particle size of adhered particles / Number-average particle size of primary particles We observed over 100 cohesive particles, determined the degree of cohesion for each particle, and calculated the average degree of cohesion.

[0274] [Crackable] 50 g of developer, consisting of 0.5 g of external additive and 49.5 g of carrier, placed in a 50 mL bottle (manufactured by Nichiden Rika Glass Co., Ltd.), was stirred using a rocking mill (manufactured by Seiwa Giken Co., Ltd.) at 67 Hz for 10 minutes. The stirred developer was diluted and dispersed in tetrahydrofuran (THF), and after separating the external additive into the supernatant, it was observed using a field emission scanning electron microscope (FE-SEM). The cleavage (%), which is the ratio of fractured or disintegrated particles to 1,000 particles of the external additive, was determined from the FE-SEM observation.

[0275] [Table 1-1]

[0276] [Table 1-2]

[0277] <Manufacturing of resin particles> [Example 1] (Preparation process of the oil phase) 50 parts by mass of [amorphous polyester resin A-1], 50 parts by mass of [crystalline polyester resin dispersion C-1], 50 parts by mass of [WAX dispersion 1], 550 parts by mass of [amorphous polyester resin B-1], 700 parts by mass of flake-type recycled PET, and 100 parts by mass of [masterbatch 1] were placed in a container and mixed at 5,000 rpm for 60 minutes using a TK homomixer (manufactured by Primix Co., Ltd.) to obtain [oil phase 1]. The above proportions indicate the proportion of solids in each raw material.

[0278] (Aqueous phase preparation process) 990 parts by mass of water, 20 parts by mass of sodium dodecyl sulfate, and 90 parts by mass of ethyl acetate were mixed and stirred to obtain a milky white liquid. This was designated as [Aqueous Phase 1].

[0279] (Manufacturing process for emulsified slurry) [Oil phase 1] 700 parts by mass was stirred in a TK homomixer at a rotation speed of 8,000 rpm while 20 parts by mass of 28% aqueous ammonia was added and mixed for 10 minutes. Then, 1,200 parts by mass of [Aqueous phase 1] was gradually added dropwise to obtain [Emulsified slurry 1].

[0280] (Manufacturing process for solvent-free slurry) [Emulsified slurry 1] was placed in a container equipped with a stirrer and thermometer, and the solvent was removed at 30°C for 180 minutes to obtain [solvent-removed slurry 1].

[0281] (Agglutination process) To [solvent-removed slurry 1], 30 parts by mass of a 5% calcium chloride solution was added dropwise as a flocculating salt and stirred for 5 minutes. The temperature was then raised to 60°C, and when the particle size reached 5.0 μm, 30 parts by mass of calcium chloride was added to complete the flocculation process, thereby obtaining [flocculated slurry 1].

[0282] (fusion process) [Agglomerated slurry 1] was heated at 70°C for 2 hours while stirring to obtain [Dispersed slurry 1].

[0283] (Washing and drying process) After filtering 100 parts of [Dispersed Slurry 1] under reduced pressure, the following operations (1) to (4) were repeated three times to obtain [Filtration Cake 1]. (1): 100 parts of deionized water were added to the filter cake, mixed with a TK homomixer (at a rotation speed of 12,000 rpm for 10 minutes), and then filtered. (2): 100 parts of a 10% sodium hydroxide aqueous solution were added to the filtered cake from (1), mixed in a TK homomixer (at 12,000 rpm for 30 minutes), and then filtered under reduced pressure. (3): 150 parts of 10% hydrochloric acid were added to the filtered cake from (2), mixed in a TK homomixer (at 12,000 rpm for 20 minutes), and then filtered. (4): 300 parts of deionized water were added to the filtration cake from (3), mixed with a TK homomixer (at a rotation speed of 12,000 rpm for 10 minutes), and then filtered. The obtained [filter cake 1] was dried in a circulating air dryer at 45°C for 48 hours, and then sieved through a mesh with a mesh opening of 75 μm to obtain [resin particle matrix 1].

[0284] (External additive treatment process) To 100 parts by mass of [resin particle matrix 1], 1.0 part by mass of external additive 1 was added as silica particle A and mixed in a Henschel mixer for 6 minutes. Then, 1.2 parts by mass of small-particle silica (H1303VP (average primary particle size 23 nm, manufactured by Clariant)) was added as silica particle B and mixed in a Henschel mixer for 2 minutes. After mixing, the mixture was passed through a 500-mesh sieve to obtain [resin particle 1].

[0285] [Example 2] In Example 1, the same procedure was followed except that silica particles A were replaced with external additive 2 to produce [resin particles 2].

[0286] [Example 3] In Example 1, the process was carried out in the same manner as in Example 1, except that the fusion time in the fusion process was changed to 0.5 hours and silica particles A was replaced with external additive 2, in order to produce [resin particles 3].

[0287] [Example 4] In Example 1, the process was carried out in the same manner as in Example 1, except that the fusion temperature in the fusion process was changed to 72°C and the fusion time to 4 hours, and silica particles A was changed to external additive 2. [Resin particles 4] were produced.

[0288] [Example 5] In Example 1, the process was carried out in the same manner as in Example 1, except that the amount of flake-shaped recycled PET in the oil phase preparation step was changed to 300 parts by mass, the fusion time in the fusion step was changed to 0 hours, and silica particles A was changed to external additive 2. [Resin particles 5] were produced.

[0289] [Example 6] In Example 1, the process was carried out in the same manner as in Example 1, except that the amount of flake-shaped recycled PET in the oil phase preparation step was changed to 300 parts by mass, the mixing time of silica particles A was changed to 2 minutes, and silica particles A was changed to external additive 2. [Resin particles 6] were produced.

[0290] [Example 7] In Example 1, the process was carried out in the same manner as in Example 1, except that the amount of flake-shaped recycled PET in the oil phase preparation step was changed to 300 parts by mass, the fusion time in the fusion step was changed to 0 hours, the mixing time for silica particles B was changed to 8 minutes, and silica particles A was changed to external additive 2. [Resin particles 7] were produced.

[0291] [Comparative Example 1] In Example 1, the same procedure was followed except that silica particle A was changed to spherical silica (X-24 (average primary particle diameter 120 nm, manufactured by Shin-Etsu Chemical Co., Ltd.)) to produce [resin particle 8].

[0292] [Comparative Example 2] In Example 1, the process was carried out in the same manner as in Example 1, except that the flake-shaped recycled PET was not mixed in the oil phase preparation step, and silica particles A was replaced with external additive 2. [Resin particles 9] were then produced.

[0293] The composition of resin particles 1 to 9 is shown in Table 2-1. The PET content in Table 2-1 indicates the percentage (by mass) of recycled PET relative to the total mass of polyester resin contained in the resin particle matrix.

[0294] [Table 2-1]

[0295] <Evaluation of resin particles 1-9> [Silica release rate Xs based on ultrasonic vibration method] 10 g of polyoxyalkylene alkyl ether (Neugen ET-165, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) and 300 ml of pure water were placed in a 500 ml beaker and dispersed by sonication for 1 hour to obtain dispersion A. Then, dispersion A was transferred to a 2 L volumetric flask, the volume was increased to make up, and dissolved by sonication for 1 hour to obtain 0.5% dispersion B. Pour 50 ml of 0.5% dispersion B into a 110 ml screw-cap tube, and then add 3.75 g of the resin particles to be used as the sample. Stir for 30 to 90 minutes until the screw-cap tube is saturated with the dispersion to prepare solution C. During this time, stir as gently as possible to avoid creating bubbles. After thoroughly dispersing the resin particles, an ultrasonic homogenizer (VCX750SONICS, 750 watts) is used to prepare liquid D by inserting the vibrating part 2.5 cm into liquid C and vibrating it for 1 minute at 40% output energy. Place the above liquid D into a 50 ml centrifuge tube and centrifuge at 2000 rpm for 2 minutes to obtain supernatant liquid E and precipitate. Wash the precipitate with 60 ml of pure water and pour it into a separator, then remove the washing water by suction filtration. Place the filtered sample back into the mini cup, measure 60 ml of water using a graduated cylinder and pour it into the mini cup, then stir 5 times with the handle of a spatula. Do not stir too vigorously at this time. The washing water is removed again by suction filtration, and the resin particles remaining on the filter paper are collected and dried in a 40°C constant temperature bath for 8 hours. 3g of the dried resin particles is taken and molded into pellets with a diameter of 3mm and a thickness of 2mm using an automatic pressure molding machine (T-BRB-32, manufactured by Maekawa Co., Ltd.) under conditions of a load of 6.0t and a pressurizing time of 60sec. These pellets are then processed and used as samples. On the other hand, untreated resin particles are used as the initial sample, and these resin particles are molded into pellets with a diameter of 3 mm and a thickness of 2 mm using an automatic pressure molding machine, as described above, to create a sample before processing. Next, quantitative analysis is performed on the post-treatment and pre-treatment samples using an X-ray fluorescence spectrometer (ZSX-100e: manufactured by Rigaku Denki Co., Ltd.), and the parts by mass of metal in each sample is measured. The calibration curve used to calculate the parts by mass is created by preparing samples with predetermined metal content for resin particles (for example, 0.1 parts by mass, 1 part by mass, and 1.8 parts by mass), and referring to the results of the quantitative analysis obtained using the X-ray fluorescence spectrometer. The silica release rate Xs is calculated using the following formula (1). Silica liberation rate Xs = [{Metal content of sample before treatment (parts) - Metal content of sample after treatment (parts)} / Metal content of sample before treatment (parts)] × 100 ... (1) However, the metal in equation (1) represents a silicon atom.

[0296] [BET specific surface area] After weighing 1.0 g of the resin particles obtained in a sample cell, the particles were vacuum-dried for 24 hours using a pre-treatment Smart Prep (manufactured by Shimadzu Corporation) to remove impurities and moisture from the surface of the resin particles. Next, the pre-treated resin particles were placed in an automatic specific surface area / pore distribution analyzer, and the relationship between nitrogen gas adsorption and relative pressure was determined. The BET specific surface area was then determined using the BET multi-point method. The BET specific surface area was measured using an automated specific surface area / pore distribution analyzer (device name: TriStar3000, manufactured by Shimadzu Corporation).

[0297] Table 2-2 shows the silica release rate Xs and BET specific surface area of ​​resin particles 1-9.

[0298] [Table 2-2]

[0299] <Evaluation of characteristics> Resin particles 1-9 were used as toner, and their characteristics, including static charge stability over time, carrier contamination, toner replenishment, and environmental friendliness, were evaluated. The results of these evaluations are shown in Table 3.

[0300] [Static stability over time] A durability test was conducted by continuously printing 100,000 character image patterns with an image area ratio of 12% using a developer obtained by mixing toner and a ferrite carrier, and the change in charge during this test was evaluated. A small amount of developer was taken from the developer sleeve, and the change in charge was determined by the blow-off method and evaluated according to the following criteria. A score of "〇" or higher indicates a level that is actually usable. (Evaluation Criteria) ◎: Change in charge is less than 3 μC / g ○: Change in charge is 3 μC / g or more and less than 6 μC / g △: Change in charge is between 6 μC / g and less than 10 μC / g ×: Change in charge is 10 μC / g or more

[0301] [Carrier contamination] Using a two-component developer, a print durability test was conducted using an image forming apparatus (Ricoh Imagio Neo C355 copier) at a document density of 5%, with 50,000 prints. After forming the 50,000th image, the toner from the developer was removed by blow-off, and 1g of the resulting material was washed with a surfactant. This was then dissolved in THF, and its absorbance was measured using a spectrophotometer (CT3500, Hitachi, Ltd.). A calibration curve was created using the toner amount (concentration) of the prepared two-component developer and the absorbance measured as described above. The amount of toner contaminating the carrier was then quantified and evaluated according to the following criteria. A score of "〇" or higher indicates a level suitable for actual use. (Evaluation Criteria) ◎: Carrier contamination amount is 0.1 mg or less ○: The amount of toner contaminating the carrier is more than 0.1 mg but less than or equal to 0.2 mg. △: The amount of toner contaminating the carrier is more than 0.2 mg but less than or equal to 0.3 mg. ×: The amount of toner contaminating the carrier is greater than 0.3 mg.

[0302] [Toner replenishment capability] An evaluation machine, modified from the toner supply unit of a commercially available digital full-color printer (RICOH Pro C901, A4 size landscape color 90 pages / minute, manufactured by Ricoh Co., Ltd.), was loaded with the toners of the examples and comparative examples. After being stored at 50°C for 24 hours, images were printed until the toner end detection was activated (until the toner supply ran out), and evaluated according to the following criteria. The toners used were stored for one month in a constant temperature chamber set to 40°C ± 2°C and 70% ± 5% RH before the evaluation. A rating of "△" or higher indicates a level that is actually usable. (Evaluation Criteria) ◎: No change in replenishment until the toner runs out, and the amount of remaining toner in the toner storage container at the end of the toner cycle is less than 1g. ○: No change in replenishment until the toner runs out, but the amount of remaining toner in the toner storage container at the end of the toner run is between 1g and 5g. △: The toner end light illuminated because toner remained in the storage container, but it recovered after vibrating the storage container. ×: The toner end light illuminates when toner remains in the storage container, and does not recover even when the storage container is shaken.

[0303] [Environmental compatibility] The environmental friendliness of the toner was evaluated based on the ratio of environmentally friendly resins in the toner, according to the following evaluation criteria. (Evaluation Criteria) A: More than 50% recycled resin B: Recycled resin is between 30% and less than 50% C: Less than 30% recycled resin

[0304] [Table 3]

[0305] From Table 3, it was confirmed that the resin particles of Examples 1 to 7 are all toners that satisfy the conditions for use in terms of chargeability, toner replenishability, spent property, and environmental compatibility. In contrast, the resin particles obtained in Comparative Examples 1 and 2 were confirmed to be toners having practical problems because at least one of chargeability, toner replenishability, spent property, and environmental compatibility did not satisfy the conditions for use.

[0306] As described above, the embodiments have been explained. However, the above embodiments are presented as examples, and the present invention is not limited by the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, replacements, changes, etc. can be made without departing from the gist of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalent scope thereof.

[0307] Incidentally, aspects of the embodiments of the present invention are as follows, for example. <1> Resin particles obtained by adding an external additive containing a plurality of types of silica particles having different volume average particle diameters to the surface of matrix particles containing an amorphous resin, a crystalline resin, and polyethylene terephthalate and / or polybutylene terephthalate, Among the plurality of types of silica particles, silica particle A having the largest volume average particle diameter is a non-spherical aggregated particle composed of secondary particles formed by aggregation of a plurality of primary particles, and silica particle B having the smallest volume average particle diameter is a spherical particle composed of primary particles. <2> The resin particles according to <1>, wherein the silica release rate Xs measured by free silica measurement based on the ultrasonic vibration method is 35 to 70%. <3> The resin particles according to any one of <1> to <2>, wherein the total of polyethylene terephthalate and polybutylene terephthalate is 30% by mass or more. <4> The BET specific surface area of the matrix particles is 0.8 to 1.4 m 2It is characterized by being / g <1> from <3> The resin particles are those described in any one of the items. <5> The silica particles A are characterized by satisfying the following formula (1). <1> from <4> The resin particles are those described in any one of the items. Nx / 1,000×100≦30%...Formula (1) However, in formula (1) above, Nx represents the number of primary particles in 1,000 particles of the external additive. Nx is measured by stirring 0.5 g of the external additive and 49.5 g of the carrier in a 50 mL bottle with a mixing stirrer at 67 Hz for 10 minutes, and then observing with a scanning electron microscope. <6> <1> from <5> A method for producing resin particles according to any one of the items, A step of preparing a solution by dissolving or dispersing an amorphous resin, a crystalline resin, and polyethylene terephthalate and / or polybutylene terephthalate in an organic solvent, The process involves adding water to the aforementioned dissolving solution to invert the phase from a water-in-oil dispersion to an oil-in-water dispersion, A step of agglomerating the fine particles of the oil-in-water dispersion, This is a method for producing resin particles, characterized by containing [a specific ingredient / method]. <7> <1> from <5> This toner contains resin particles as described in any one of the items. <8> Electrostatic latent image carrier, An electrostatic latent image forming unit that forms an electrostatic latent image on the electrostatic latent image carrier, The electrostatic latent image formed on the electrostatic latent image carrier, <7> A developing unit that develops using the toner described above to form a toner image, This is an image forming apparatus characterized by having [a certain feature].

[0308] The aforementioned <1> from <5> The resin particles described above, <6> The method for producing resin particles as described above <7> The toner described above, <8> The image forming apparatus described above can solve the aforementioned problems of the conventional method and achieve the objectives of the present invention. [Explanation of symbols]

[0309] 160Y Sub-hopper (Yellow) 160C Sub-hopper (Cyan) 160M Sub-hopper (Magenta) 160K Sub-hopper (Black) 180Y Image Forming Unit (Yellow) 180C Image Forming Unit (Cyan) 180M Image Forming Unit (Magenta) 180K Image Forming Unit (Black) 200 Image forming apparatus 210 Paper feed section 211 Paper feed cassette 212 Paper feed roller 220 Conveying section 221 Laura 222 Timing Roller 223 Paper output roller 224 Paper Output Tray 230 Image creation section 231Y Photoconductor Drum (Yellow) 231C Photoconductor Drum (Cyan) 231M Photoconductor Drum (Magenta) 231K Photoconductor Drum (Black) 232Y Charger (Yellow) 232C Charger (Cyan) 232M Charger (Magenta) 232K Charger (Black) 233 Exposure Unit 233a light source 233bY Polygon Mirror (Yellow) 233bC Polygon Mirror (Cyan) 233bM Polygon Mirror (Magenta) 233bK Polygon Mirror (Black) 234Y Toner Bottle (Yellow) 234C Toner Bottle (Cyan) 234M Toner Bottle (Magenta) 234K Toner Bottle (Black) 236Y Cleaning device (yellow) 236C Cleaning device (Cyan) 236M Cleaning Machine (Magenta) 236K Cleaning Device (Black) 240 Transfer section 241 Drive roller 242 Driven roller 243 Intermediate transfer belt 244 Primary Transfer Roller 244Y Primary Transfer Roller (Yellow) 244C Primary Transfer Roller (Cyan) 244M Primary Transfer Roller (Magenta) 244K Primary Transfer Roller (Black) 245 Secondary opposing roller 246 Secondary Transfer Roller 250 Fuser 251 Fixing belt 252 Pressure roller L Laser P paper [Prior art documents] [Patent Documents]

[0310] [Patent Document 1] Patent No. 4894876

Claims

1. Resin particles comprising a matrix particle containing an amorphous resin, a crystalline resin, and polyethylene terephthalate and / or polybutylene terephthalate, to which an external additive containing multiple types of silica particles with different volume-average particle sizes is added, The resin particle is characterized in that, among the multiple types of silica particles, silica particle A, which has the largest volume-average particle size, is a non-spherical aggregated particle composed of secondary particles formed by the aggregation of multiple primary particles, and silica particle B, which has the smallest volume-average particle size, is a spherical particle composed of primary particles.

2. The resin particles according to claim 1, characterized in that the silica free rate Xs measured by the free silica measurement method based on ultrasonic vibration is 35 to 70%.

3. The resin particles according to claim 1, characterized in that the total amount of polyethylene terephthalate and polybutylene terephthalate is 30% by mass or more.

4. The BET specific surface area of ​​the aforementioned parent particles is 0.8 to 1.4 m². ２ The resin particles according to claim 1, characterized by being / g.

5. The resin particle according to claim 1, characterized in that the silica particle A satisfies the following formula (1). Nx / 1,000×100≦30%...Formula (1) However, in formula (1) above, Nx represents the number of primary particles in 1,000 particles of the external additive. Nx is measured by stirring 0.5 g of the external additive and 49.5 g of the carrier in a 50 mL bottle with a mixing stirrer at 67 Hz for 10 minutes, and then observing with a scanning electron microscope.

6. A method for producing resin particles according to any one of claims 1 to 5, A step of preparing a solution by dissolving or dispersing an amorphous resin, a crystalline resin, and polyethylene terephthalate and / or polybutylene terephthalate in an organic solvent, The process involves adding water to the aforementioned dissolving solution to invert the phase from a water-in-oil dispersion to an oil-in-water dispersion, A step of agglomerating the fine particles of the oil-in-water dispersion, A method for producing resin particles, characterized by containing [the specified component].

7. Toner comprising resin particles according to any one of claims 1 to 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 formed on the electrostatic latent image carrier using the toner described in claim 7 to form a toner image, An image forming apparatus characterized by having the following features.

Images