Resin particles, method for manufacturing resin particles, and toner

Abstract

To provide resin particles that suppress environmental impact and, even when a polyethylene terephthalate or polybutylene terephthalate component is used, exhibits excellent chargeability and enables formation of an image having excellent image quality even under high-humidity conditions.SOLUTION: The resin particles according to the present invention include a mother particle containing polyethylene terephthalate or polybutylene terephthalate and an external additive, the mother particle having the BET specific surface area of 0.8-1.4 m2 / g, and the external additive including two types of fine particles: fine particles A having an average particle diameter of at least 100 nm and fine particles B having the average particle diameter of 10-50 nm, and the content ratio (mass ratio) A / B being 0.5-1.4.SELECTED DRAWING: Figure 1

Description

[Technical Field]

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

[0002] Resin particles are widely used as toners for image forming devices such as multifunction peripherals (MFPs) and printers in various places, including offices. To reduce the environmental impact of toners, various approaches have been considered, including reducing power consumption by improving the low-temperature fixing ability of the toner itself, reducing energy consumption during production, using biomass (plant-derived) resins as binder resins, and using recycled materials as binder resins. In particular, given the increasing importance of resource conservation, energy conservation, and resource recycling, there is a growing demand for using recycled materials as binder resins.

[0003] As a toner containing a binder resin produced using recycled raw materials, for example, toner particles containing an amorphous polyester toner resin containing depolymerized PET polyol, a second amorphous resin containing depolymerized recycled PET polyol and bio-based polyester or polyacid, and a crystalline resin containing depolymerized recycled PET polyol have been disclosed (see Patent Document 1). Summary of the Invention [Problem to be solved by the invention]

[0004] However, the toner particles of Patent Document 1 contain polyethylene terephthalate or polybutylene terephthalate components, which affect the properties of the toner particles, such as poor charging properties and high moisture absorption, resulting in problems such as poor image quality.

[0005] The present invention aims to provide resin particles that have a reduced environmental impact, are excellent in charging properties even when a polyethylene terephthalate or polybutylene terephthalate component is used, and are capable of forming images with excellent image quality even in a high-humidity environment. [Means for solving the problem]

[0006] The above problem is solved by the following configuration 1). 1) Resin particles containing mother particles containing polyethylene terephthalate or polybutylene terephthalate and an external additive, The BET specific surface area of ​​the base particles is 0.8 to 1.4 m 2 / g, The external additive contains at least two types of particles: fine particles A having an average particle diameter of 100 nm or more and fine particles B having an average particle diameter of 10 to 50 nm, and the content ratio (mass ratio) A / B of the fine particles A to B is 0.5 to 1.4. [Effects of the Invention]

[0007] According to the present invention, it is possible to provide resin particles that have a reduced environmental impact, have excellent charging properties even when using polyethylene terephthalate or polybutylene terephthalate components, and are capable of forming images with excellent image quality even in high-humidity environments. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a schematic diagram showing an example of an image forming apparatus according to the present invention. [Figure 2] FIG. 2 is a schematic view showing an example of a process cartridge according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described in detail. Note that the embodiments are not limited by the following description and can be modified as appropriate within the scope of the present invention. Furthermore, in this specification, unless otherwise specified, the symbol "to" indicating a numerical range means that the numerical values ​​before and after it are included as the lower limit and upper limit.

[0010] <Resin particles> Resin particles according to one embodiment will be described. The resin particles according to one embodiment contain mother particles containing polyethylene terephthalate (PET) or polybutylene terephthalate (PBT) and an external additive. The resin particles according to one embodiment preferably further contain an amorphous resin, a crystalline resin, and a release agent in addition to PET or PBT, and may contain other components as necessary.

[0011] [PET or PBT] The PET or PBT contained in the resin particles according to one embodiment is contained in the resin particles mainly to reduce the environmental load.

[0012] There are no particular restrictions on the PET or PBT, and it can be selected appropriately depending on the purpose. For example, recycled products, off-specification fiber waste, or pellets can be used. However, from the viewpoint of reducing the environmental load, recycled products (hereinafter sometimes referred to as "recycled resin") processed into flakes are preferred.

[0013] There are no particular limitations on the molecular weight distribution, composition, production method, and form when used of PET or PBT, and they can be appropriately selected depending on the purpose.

[0014] The weight average molecular weight (Mw) of PET or PBT is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 30,000 to 100,000.

[0015] The methods for analyzing and calculating the content of PET or PBT in the resin particles are not particularly limited, and a general method for calculating the blending amount of PET can be used. For example, the PET or PBT content can be separated from the resin particles by gel permeation chromatography (GPC) or the like, and the mass ratio of the constituent components of the resin particles can be calculated by subjecting each separated component to the analytical method described below.

[0016] Quantitative analysis can also be performed by using gas chromatography / mass spectrometry (GC / MS) at 300°C with a reaction reagent (10% tetramethyl ammonium hydroxide (TMAH) / methanol solution) to estimate the main components from the soft decomposition of the ester bonds in the resin particles due to methylation, and drawing a calibration curve of the total ion current chromatogram (TICC) intensity.

[0017] Separation of each component by GPC can be carried out, for example, by the following method.

[0018] 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 full integral of the elution curve are collected.

[0019] The combined eluate is concentrated and dried using an evaporator or the like, and the solid content is then dissolved in a heavy solvent such as deuterated chloroform or deuterated THF, 1 H-NMR measurement is performed, and the ratio of constituent monomers of the resin in the eluted components is calculated from the integral ratio of each element.

[0020] Alternatively, the eluate may be concentrated, hydrolyzed with sodium hydroxide or the like, and the decomposition products may be subjected to qualitative and quantitative analysis by high performance liquid chromatography (HPLC) or the like to calculate the proportion of constituent monomers.

[0021] The content of PET or PBT is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 30% by mass or more, and more preferably 30 to 70% by mass, relative to the total mass of the resin particles. When the content of PET or PBT is 70% by mass or less, relative to the total mass of the resin particles, low-temperature fixability can be exhibited. When the content of PET or PBT is 30% by mass or more, the effect of reducing environmental impact can be exhibited, and the resin particles can have an excellent particle size distribution. The content of PET or PBT within the above more preferred range is advantageous in that it can simultaneously reduce the environmental impact of the resin particles and improve the particle size distribution.

[0022] An example of a method for separating components contained in resin particles when analyzing resin particles according to one embodiment is described in detail below. First, 1 g of resin particles is placed in 100 mL of THF and stirred at 25°C for 30 minutes to obtain a solution in which the soluble components are dissolved. The solution is then filtered through a 0.2 μm membrane filter to obtain the THF-soluble components of the resin particles. This is then dissolved in THF to prepare a sample for GPC measurement and injected into the GPC used to measure the molecular weight of each of the resins described above. Meanwhile, a fraction collector is placed at the GPC eluate outlet, and eluate is collected at predetermined counts, obtaining eluate at 5% area fractions from the start of elution (the rise of the curve) of the elution curve. Next, for each eluate, 30 mg of 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 a spectrum is obtained using a nuclear magnetic resonance spectrometer (JNM-AL400 manufactured by JEOL Ltd.) at a temperature of 23 to 25°C, with 128 integrations. The monomer composition and constituent ratio of the PET resin and other components contained in the resin particles can be determined from the peak integral ratio of the obtained spectrum.

[0023] Therefore, the resin particles according to one embodiment can reduce the environmental load and have an excellent particle size distribution.

[0024] As described above, the resin particles according to one embodiment preferably contain an amorphous resin, a crystalline resin, and a release agent in addition to PET or PBT.

[0025] The total content of PET or PBT relative to the total mass of the resin particles is preferably 30% by mass or more, more preferably 40% by mass or more, and even more preferably 50% by mass or more.

[0026] [Amorphous resin] The resin particles according to one embodiment preferably contain an amorphous resin.

[0027] The amorphous resin is preferably a terpene resin or an amorphous (non-crystalline) polyester resin (hereinafter also referred to as "amorphous polyester resin B"). Among them, a linear polyester resin is preferable, and an unmodified polyester resin is also preferable. In this embodiment, the amorphous resin refers to a resin excluding PET or PBT.

[0028] The unmodified polyester resin is a polyester resin obtained using a polyhydric alcohol and a polycarboxylic acid or a derivative thereof, such as a polycarboxylic acid, a polycarboxylic acid anhydride, or a polycarboxylic acid ester, and is not modified with an isocyanate compound or the like.

[0029] The amorphous polyester resin preferably does not contain a urethane bond or a urea bond.

[0030] The amorphous polyester resin preferably contains a dicarboxylic acid component as a constituent, and the dicarboxylic acid component preferably contains 50 mol % or more of terephthalic acid, which is advantageous in terms of heat-resistant storage stability.

[0031] Examples of polyhydric alcohols include diols.

[0032] Examples of diols include alkylene (carbon number 2 to 3) oxide (average number of added moles 1 to 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 (carbon number 2 to 3) oxide (average number of added moles 1 to 10) adducts of hydrogenated bisphenol A.

[0033] These may be used alone or in combination of two or more.

[0034] Among these, plant-derived ethylene glycol and propylene glycol are preferred.

[0035] Examples of polycarboxylic acids include dicarboxylic acids.

[0036] Examples of dicarboxylic acids include adipic acid, phthalic acid, isophthalic acid, terephthalic acid, fumaric acid, maleic acid, succinic acids substituted with an alkyl group having 1 to 20 carbon atoms or an alkenyl group having 2 to 20 carbon atoms, such as dodecenylsuccinic acid and octylsuccinic acid, and modified purified rosin. Preferred modified purified rosins are those modified with acrylic acid, fumaric acid, and maleic acid.

[0037] Among these, succinic acid, a saturated aliphatic acid derived from a plant, and modified purified rosin are preferred. Being derived from a plant can enhance carbon neutrality. Saturated aliphatic acids have the effect of enhancing the recrystallization properties of crystalline polyester resins, increasing the aspect ratio of the crystalline polyester resins, and improving low-temperature fixability.

[0038] These may be used alone or in combination of two or more.

[0039] Furthermore, for the purpose of adjusting the acid value and hydroxyl value, the 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.

[0040] Examples of trivalent or higher carboxylic acids include trimellitic acid, pyromellitic acid, and acid anhydrides thereof.

[0041] Examples of trihydric or higher alcohols include glycerin, pentaerythritol, and trimethylolpropane.

[0042] The molecular weight of the amorphous polyester resin is not particularly limited and can be appropriately selected depending on the purpose. The weight average molecular weight (Mw) measured by gel permeation chromatography (GPC) is preferably 3,000 to 10,000. The number average molecular weight (Mn) is preferably 1,000 to 4,000. The ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn), Mw / Mn, is preferably 1.0 to 4.0.

[0043] When the molecular weight is equal to or greater than the lower limit, it is possible to prevent the resin particles from having a reduced heat-resistant storage stability and a reduced durability against stress caused by stirring in a developing machine, etc. When the molecular weight is equal to or less than the upper limit, it is possible to prevent the resin particles from having an increased viscoelasticity when melted, and to prevent a reduced low-temperature fixability.

[0044] 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 Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is more preferably 1.0 to 3.5.

[0045] The acid value of the amorphous polyester resin is not particularly limited and can be appropriately selected depending on the purpose. It is preferably 1 mgKOH / g to 50 mgKOH / g, and more preferably 5 mgKOH / g to 30 mgKOH / g. An acid value of 1 mgKOH / g or more makes the resin particles more likely to be negatively charged, and further improves the affinity between the paper and the resin particles during fixation to paper, thereby improving low-temperature fixability. An acid value of 50 mgKOH / g or less can prevent a decrease in charging stability, particularly charging stability against environmental changes.

[0046] The hydroxyl value of the amorphous polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 5 mgKOH / g or more.

[0047] The glass transition temperature (Tg) of the amorphous polyester resin is preferably 40°C to 80°C, more preferably 50°C to 70°C. When the glass transition temperature (Tg) is 40°C or higher, the resin particles have sufficient heat-resistant storage stability and durability against stress such as stirring in a developing machine, and also have good filming resistance. When the glass transition temperature (Tg) is 80°C or lower, the resin particles are sufficiently resistant to deformation due to heat and pressure during fixing, and good low-temperature fixability is achieved.

[0048] The molecular structure of the amorphous polyester resin can be confirmed by NMR measurement in solution or solid, as well as X-ray diffraction, GC / MS, LC / MS, and IR measurement. -1 and 990±10cm -1 One method is to detect amorphous polyester resins that do not have absorption due to olefin δCH (out-of-plane bending vibration).

[0049] The content of the amorphous resin is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 50 to 90 parts by weight, and more preferably 60 to 80 parts by weight, per 100 parts by weight of resin particles. A content of 50 parts by weight or more can prevent deterioration of the dispersibility of the pigment and release agent in the resin particles, thereby preventing image fogging and distortion. A content of 90 parts by weight or less can prevent a decrease in the contents of, for example, the following crystalline polyester resin C and amorphous polyester resin B, and suppress a decrease in low-temperature fixability. A content within the above-mentioned more preferred range is advantageous in that both high image quality and low-temperature fixability are excellent.

[0050] [Amorphous resin (prepolymer)] The resin particles according to one embodiment may contain an amorphous resin (prepolymer) as the amorphous resin in order to improve low-temperature fixability, and the prepolymer is preferably modified with an isocyanate compound or the like.

[0051] Reactive precursors include polyesters having groups capable of reacting with active hydrogen groups.

[0052] Examples of the group capable of reacting with the active hydrogen group include an isocyanate group, an epoxy group, a carboxylic acid, an acid chloride group, etc. Among these, an isocyanate group is preferred because it can introduce a urethane bond or a urea bond into the amorphous polyester resin.

[0053] The reactive precursor may have a branched structure imparted by at least one of a trivalent or higher alcohol and a trivalent or higher carboxylic acid.

[0054] Examples of polyester resins containing an isocyanate group include reaction products of polyester resins having active hydrogen groups and polyisocyanates (hereinafter sometimes referred to as amorphous polyester resin A).

[0055] The polyester resin having an active hydrogen group 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 an isocyanate group.

[0056] 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 of suitable diols include diols having an oxyalkylene group 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, such as 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 the amorphous polyester resin A to 20° C. or less, 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 alone or in combination of two or more.

[0057] The amorphous polyester resin A has steric hindrance in the resin chain, which reduces the melt viscosity during fixing and makes it easier to achieve low-temperature fixability. For this reason, the main chain of the aliphatic diol preferably has a structure represented by the following general formula (1): HO-(CR1R2)n-OH General formula (1) where R1 and R2 each independently represent a hydrogen atom or an alkyl group having 1 to 3 carbon atoms, and n represents an odd number from 3 to 9. In the n repeating units, R1 and R2 may be the same or different.

[0058] Here, the main chain of an aliphatic diol refers to the carbon chain that connects two hydroxyl groups of the aliphatic diol with the shortest number of carbon atoms. The main chain preferably has an odd number of carbon atoms, since the odd-even ratio reduces crystallinity. Furthermore, the main chain preferably has at least one alkyl group having 1 to 3 carbon atoms in the side chain, since the interaction energy between the main chain molecules is reduced due to the stericity.

[0059] 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. Furthermore, anhydrides, lower (C1-C3) alkyl esters, and halides of these dicarboxylic acids may also be used. Among these, aliphatic dicarboxylic acids having from 4 to 12 carbon atoms are preferred from the viewpoint of controlling the glass transition temperature (Tg) of the amorphous polyester resin A to 20°C or less, and it is more preferable to use them in an amount of 50% by mass or more of the carboxylic acid components in the resin. These dicarboxylic acids may be used alone or in combination of two or more.

[0060] Examples of trihydric or higher alcohols include trihydric or higher aliphatic alcohols such as glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, and sorbitol; trihydric or higher polyphenols such as trisphenol PA, phenol novolac, and cresol novolac; and alkylene oxide adducts of trihydric or higher polyphenols, such as those obtained by adding alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide to trihydric or higher polyphenols.

[0061] Examples of trivalent or higher carboxylic acids include trivalent or higher aromatic carboxylic acids, and particularly preferred are trivalent or higher aromatic carboxylic acids having 9 to 20 carbon atoms, such as trimellitic acid and pyromellitic acid. Furthermore, anhydrides, lower (1 to 3 carbon atoms) alkyl esters, and halides of these may also be used.

[0062] Examples of polyisocyanates include diisocyanates and tri- or higher valent isocyanates.

[0063] The polyisocyanate is not particularly limited and can be appropriately selected depending on the purpose. Examples of the polyisocyanate include 1,3- and / or 1,4-phenylene diisocyanate, 2,4- and / or 2,6-tolylene diisocyanate (TDI), crude TDI, 2,4'- and / or 4,4'-diphenylmethane diisocyanate (MDI), crude MDI [crude diaminophenylmethane [condensation product of formaldehyde and aromatic amine (aniline) or a mixture thereof; diaminodiphenylmethane and a small amount (for example, 5 to 20% by mass) of a trifunctional or higher functional group], Phosgenates of polyallyl polyisocyanate (PAPI), aromatic diisocyanates such as 1,5-naphthylene diisocyanate, 4,4',4"-triphenylmethane triisocyanate, m- and p-isocyanatophenylsulfonyl isocyanate; ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, Aliphatic diisocyanates such as isocyanate, 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) alicyclic diisocyanates such as m- and p-xylylene diisocyanate (XDI) and α,α,α',α'-tetramethylxylylene diisocyanate (TMXDI); trivalent or higher polyisocyanates such as lysine triisocyanate and diisocyanate-modified products of trivalent or higher alcohols; and modified products of these isocyanates, and mixtures of two or more of these may also be used.Examples of the modified isocyanate include modified products containing a urethane group, a carbodiimide group, an allophanate group, a urea group, a biuret group, a uretdione group, a uretoimine group, an isocyanurate group, and an oxazolidone group.

[0064] [Crystalline resin] In one embodiment, a crystalline resin is preferably added to the resin particles in order to improve low-temperature fixability.

[0065] The crystalline resin is not particularly limited as long as it has crystallinity and can be appropriately selected depending on the purpose. Examples include polyester resin, polyurethane resin, polyurea resin, polyamide resin, polyether resin, vinyl resin, modified crystalline resin, etc. These may be used alone or in combination of two or more.

[0066] The polyester resin used in the crystalline resin is a crystalline polyester resin (hereinafter, may be referred to as "crystalline polyester resin C"). Crystalline polyester resin C will be described below.

[0067] Crystalline polyester resin C has high crystallinity and therefore exhibits heat melting characteristics that result in a sudden change in viscosity near the fixing start temperature.

[0068] Resin particles having good heat-resistant storage stability and low-temperature fixability can be obtained by using crystalline polyester resin C having such properties together with amorphous polyester resin B. For example, by using them together, the heat-resistant storage stability is good due to the crystallinity up to just before the melting start temperature, and at the melting start temperature, the crystalline polyester resin C melts, causing a sudden decrease in viscosity (sharp melt property), which in turn makes it compatible with the amorphous polyester resin B described above, and both resins rapidly decrease in viscosity, allowing for good fixation.

[0069] (Crystalline polyester resin) The crystalline polyester resin is obtained from a polyhydric alcohol and a polycarboxylic acid or a derivative thereof, such as a polycarboxylic acid, a polycarboxylic acid anhydride, or a polycarboxylic acid ester.

[0070] In this embodiment, the crystalline polyester resin refers to a resin obtained by using a polyhydric alcohol and a polycarboxylic acid or a derivative thereof, such as a polycarboxylic acid, a polycarboxylic acid anhydride, or a polycarboxylic acid ester, as described above. Modified polyester resins, such as prepolymers, and resins obtained by subjecting such prepolymers to a crosslinking and / or elongation reaction, do not fall under the category of crystalline polyester resins.

[0071] ((Polyhydric alcohol)) The polyhydric alcohol is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include diols and trihydric or higher alcohols.

[0072] Examples of diols include saturated aliphatic diols. Examples of the 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 having 2 to 12 carbon atoms are more preferred. If the saturated aliphatic diol is branched, the crystallinity of the crystalline polyester resin may decrease, resulting in a lower melting point. Furthermore, if the saturated aliphatic diol has more than 12 carbon atoms, it may be difficult to obtain a practical material.

[0073] Examples of the saturated aliphatic diol 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, 1,14-eicosanedecanediol, etc. 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 in terms of the high crystallinity and excellent sharp melt properties of the crystalline polyester resin.

[0074] Examples of trihydric or higher alcohols include glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, etc. These may be used alone or in combination of two or more.

[0075] ((Polycarboxylic acid)) The polycarboxylic acid is not particularly limited and can be appropriately selected depending on the purpose. Examples thereof include dicarboxylic acids and tricarboxylic or higher carboxylic acids.

[0076] Examples of dicarboxylic acids include saturated aliphatic dicarboxylic acids such as oxalic acid, succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, 1,10-decanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, and 1,18-octadecanedicarboxylic acid; and aromatic dicarboxylic acids such as phthalic acid, isophthalic acid, terephthalic acid, naphthalene-2,6-dicarboxylic acid, malonic acid, and mesaconic acid. Further examples include anhydrides of these dicarboxylic acids and their lower (1 to 3 carbon atoms) alkyl esters. Among these, saturated aliphatic dicarboxylic acids derived from plants and having 12 or fewer carbon atoms are preferred from the viewpoint of carbon neutrality.

[0077] Examples of trivalent or higher carboxylic acids include 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, and the like, as well as anhydrides and lower (C1 to C3) alkyl esters of these.

[0078] These may be used alone or in combination of two or more.

[0079] The crystalline polyester resin is preferably composed of a linear saturated aliphatic dicarboxylic acid having 4 to 12 carbon atoms and a linear saturated aliphatic diol having 2 to 12 carbon atoms. This results in high crystallinity and excellent sharp melting properties, allowing for excellent low-temperature fixability. One method for controlling the crystallinity and softening point of the crystalline polyester resin is to design and use a non-linear polyester obtained by condensation polymerization of a trivalent or higher polyhydric alcohol such as glycerin to the alcohol component or a trivalent or higher polycarboxylic acid such as trimellitic anhydride to the acid component during polyester synthesis.

[0080] The molecular structure of crystalline polyester resin can be confirmed by NMR measurement of solution or solid, X-ray diffraction, GC / MS, LC / MS, IR measurement, etc., but it can be easily confirmed by infrared absorption spectroscopy at 965±10cm -1 Or 990±10cm -1 Examples include those that have absorption based on the δCH (out-of-plane bending vibration) of olefins.

[0081] Regarding molecular weight, a polymer with a sharp molecular weight distribution and low molecular weight has excellent low-temperature fixability, while a high content of low-molecular-weight components leads to poor heat-resistant storage stability. From this perspective, it is preferable that the molecular weight distribution of the o-dichlorobenzene-soluble fraction measured by GPC, in which the horizontal axis is log(M) and the vertical axis is mass%, has a peak position in the range of 3.5 to 4.0, a peak half-width of 1.5 or less, a weight-average molecular weight (Mw) of 3,000 to 30,000, a number-average molecular weight (Mn) of 1,000 to 10,000, and a ratio Mw / Mn of 1 to 10. Even more preferable is a weight-average molecular weight (Mw) of 5,000 to 15,000, a number-average molecular weight (Mn) of 2,000 to 10,000, and a ratio Mw / Mn of 1 to 5.

[0082] The acid value of the crystalline polyester resin is preferably 5 mgKOH / g or more to achieve the desired low-temperature fixability from the viewpoint of the affinity between the resin and paper. For the preparation of fine particles by the phase inversion emulsification method, the acid value of the crystalline polyester resin is more preferably 7 mgKOH / g or more. On the other hand, for improving hot offset resistance, the acid value of the crystalline polyester resin is preferably 45 mgKOH / g or less. The hydroxyl value of the crystalline polyester resin is preferably 0 to 50 mgKOH / g, more preferably 5 to 50 mgKOH / g, in order to achieve a predetermined low-temperature fixability and good charging characteristics.

[0083] The content of the crystalline polyester resin is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 3 to 15 parts by mass per 100 parts by mass of resin particles.

[0084] [Other ingredients] The resin particles according to an embodiment may further contain an external additive and other components, such as a release agent, a colorant, a charge control agent, a cleaning improver, and a magnetic material.

[0085] (mold release agent) The release agent is not particularly limited and can be selected appropriately depending on the purpose, but a low-melting release agent with a melting point of 50° C. to 120° C. is preferred. When dispersed in the resin, the low-melting release agent effectively acts as a release agent at the interface between the fixing roller and the resin particles, thereby improving hot offset resistance even in an oil-less fixing roller (wherein a release agent such as oil is not applied to the fixing roller).

[0086] Suitable examples of release agents include waxes. Examples of waxes include natural waxes such as plant-based waxes such as carnauba wax, cotton wax, Japan wax, and rice wax; animal-based waxes such as beeswax and lanolin; mineral waxes such as ozokerite and cerusine; and petroleum waxes such as paraffin, microcrystalline wax, 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. Other examples include fatty acid amides such as 12-hydroxystearic acid amide, stearic acid amide, phthalimide anhydride, and chlorinated hydrocarbons; low-molecular-weight crystalline polymer resins such as polyacrylate homopolymers or copolymers (e.g., n-stearyl acrylate-ethyl methacrylate copolymers); and crystalline polymers having long alkyl groups in their side chains. These may be used alone or in combination of two or more.

[0087] From the viewpoint of reducing the environmental load, vegetable waxes are preferred.

[0088] The melting point of the wax is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 50°C to 120°C, more preferably 60°C to 90°C. A melting point of 50°C or higher can prevent the wax from adversely affecting heat-resistant storage stability, while a melting point of 120°C or lower can effectively prevent the problem of cold offset occurring during low-temperature fixing. 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, more preferably 10 cps to 100 cps. A melt viscosity of 5 cps or higher can prevent a decrease in release properties, while a melt viscosity of 1,000 cps or lower can fully exhibit the effects of hot offset resistance and low-temperature fixability. The content of the wax in the resin particles is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 0% to 40% by mass, more preferably 3% to 30% by mass.

[0089] (external additives) The external additive may be inorganic fine particles, polymeric fine particles, etc. The external additive contains at least two types of fine particles: fine particles A with an average particle size of 100 nm or more and fine particles B with an average particle size of 10 to 50 nm, and the content ratio (mass ratio) A / B of the fine particles A to B is 0.5 to 1.4. The average particle size is the average particle size of primary particles.

[0090] Examples of inorganic fine particles include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, iron oxide, copper oxide, zinc oxide, tin oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride, etc. Among these, silica, alumina, and titanium oxide are preferred.

[0091] The inorganic fine particles may be surface-treated with a hydrophobic treatment agent to enhance their hydrophobicity and prevent deterioration of flowability and charging properties even under high humidity. Preferred examples of the hydrophobic treatment agent include silane coupling agents, silylating agents, silane coupling agents having a fluorinated alkyl group, organic titanate coupling agents, aluminum coupling agents, silicone oils, and modified silicone oils.

[0092] Examples of polymeric fine particles include polystyrene obtained by soap-free emulsion polymerization, suspension polymerization, or dispersion polymerization, methacrylic acid ester or acrylic acid ester copolymers, polycondensation systems such as silicone, benzoguanamine, and nylon, and polymer particles made from thermosetting resins.

[0093] Furthermore, the average particle diameter of the external additives is 100 nm or more for fine particles A, preferably 150 nm or more, and more preferably 300 nm or less. The average particle diameter of fine particles B is 10 to 50 nm, preferably 20 to 30 nm. If the average particle diameter of fine particles A is 100 μm or more, the heat-resistant storage stability is improved due to the filler effect. If the average particle diameter of fine particles B is 10 nm or more, aggregation of the external additives is suppressed, and the external additives can be uniformly dispersed in the resin particles.

[0094] The average particle size is a value obtained by directly determining the particle size from a photograph obtained by a transmission electron microscope, and it is preferable to observe at least 100 particles and use the average value of the major diameters thereof.

[0095] The specific surface area of ​​the external additive by the BET method is 20 to 500 m 2 / g is preferred.

[0096] The content of the external additive is preferably 0.01% to 5% by mass of the resin particles. As mentioned above, the content ratio (mass ratio) A / B of the fine particles A to B is 0.5 to 1.4, and more preferably 0.7 to 1.2. Particles containing PET or PBT components have high electrostatic charge and high hygroscopicity, which can lead to problems with image quality, such as reduced particle transportability and cleaning performance. When the ratio A / B of the external additives A and B is 0.5 or more, excessive electrostatic charge can be suppressed, and when it is 1.4 or less, particle powder properties such as transportability can be improved.

[0097] (coloring agent) As the colorant, known dyes and pigments can be used, 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), Balkan fast yellow (5G, R), tartrazine lake, quinoline yellow lake, anthrazan yellow BGL, isoindolinone yellow -, red iron oxide, red lead, vermilion lead, cadmium red, cadmium mercury red, antimony vermilion, permanent red 4R, para red, faise red, parachlor orthonitroaniline red, Lithol Fast Scarlet G, Brilliant Fast Scarlet, Brilliant Carmine BS, permanent red (F2R, F4R, FRL, FRLL, F4RH), Fast Scarlet VD, Belcan Fast Rubin B, Brilliant Scarlet G, Lithol Rubin GX, permanent red F5R, Brilliant Carmine 6B, POG Mentos Scarlet 3B, Bordeaux 5B, Toluidine Maroon, Permanent Bordeaux F2K, Helio Bordeaux BL, Bordeaux 10B, Bon Maroon Light, Bon Maroon Medium, Eosin Lake, Rhodamine Lake B, Rhodamine Lake Y, Alizarin Lake, Thioindigo Red B, Thioindigo Maroon, Oil Red, Quinacridone Red, Pyrazolone Red, Polyazo Red, Chrome Vermilion, Benzidine Orange, Perinone Orange, Oil Orange, Cobalt Blue, Cerulean Blue, Alkaline 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 oxide, zinc oxide, lithopone, and mixtures thereof can be used.

[0098] (Charge control agent) The charge control agent may be a general charge control agent, and examples of the charge control agent include nigrosine dyes, triphenylmethane dyes, chromium-containing metal complex dyes, molybdate chelate pigments, rhodamine dyes, alkoxyamines, quaternary ammonium salts (including fluorine-modified quaternary ammonium salts), alkylamides, phosphorus simple substance or compounds, tungsten simple substance or compounds, fluorine-based activators, metal salicylate salts, and metal salts of salicylic acid derivatives. Specifically, these include the nigrosine dye Bontron 03, the quaternary ammonium salt Bontron P-51, the metal-containing azo dye Bontron S-34, the oxynaphthoic acid metal complex E-82, the salicylic acid metal complex E-84, and the phenol condensate E-89 (all manufactured by Orient Chemical Industry Co., Ltd.), the quaternary ammonium salt molybdenum complexes TP-302 and TP-415 (both manufactured by Hodogaya Chemical Co., Ltd.), the quaternary ammonium salt Copy Charge PSY VP2038, the triphenylmethane derivative Copy Blue PR, and the quaternary ammonium salt Copy Charge NEG VP2036 and Copy Charge NX. Examples include VP434 (all manufactured by Hoechst), LRA-901, the boron complex LR-147 (manufactured by Nippon Carlit), copper phthalocyanine, perylene, quinacridone, azo pigments, and other polymeric compounds having functional groups such as sulfonic acid groups, carboxyl groups, and quaternary ammonium salts.The charge control agent may be used in an amount that allows it to exhibit its performance without interfering with fixation properties, etc., and is contained in the resin particles in an amount of 0.5% to 5% by weight, and preferably 0.8% to 3% by weight.

[0099] (cleaning improver) The cleaning property improver is not particularly limited as long as it is added to resin particles to remove the developer remaining on the photosensitive member or primary transfer medium after transfer, and can be appropriately selected depending on the purpose. Examples of the cleaning property improver include fatty acid metal salts such as zinc stearate, calcium stearate, and stearic acid, and polymer fine particles produced by soap-free emulsion polymerization, such as polymethyl methacrylate fine particles and polystyrene fine particles. The polymer fine particles preferably have a relatively narrow particle size distribution, and are preferably those with a volume average particle size of 0.01 μm to 1 μm.

[0100] (Magnetic material) The magnetic material is not particularly limited and can be appropriately selected from known materials depending on the purpose, and examples thereof include iron powder, magnetite, ferrite, etc. Among these, white materials are preferred in terms of color tone.

[0101] <Characteristics of resin particles> [Particle diameter of resin particles] The particle size of resin particles according to one embodiment is measured using a Coulter Multisizer III (manufactured by Coulter). The particle size of resin particles is measured as follows: First, 2 mL of a surfactant (sodium dodecylbenzenesulfonate, manufactured by Tokyo Chemical Industry Co., Ltd.) is added as a dispersant to 100 mL of electrolyte. The electrolyte is an approximately 1% NaCl aqueous solution prepared using first-grade sodium chloride, and ISOTON-II (manufactured by Coulter) can be used. 10 mg of a measurement sample (solid content) is added to the mixture of the electrolyte and surfactant to obtain an electrolyte solution in which the sample is suspended. The electrolyte solution in which the sample is suspended is dispersed using 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. The volume average particle size (Dv) of the resin particles is determined from the resulting distribution.

[0102] [Measuring method for melting point and glass transition temperature (Tg)] The melting point and glass transition temperature (Tg) of the resin particles according to one embodiment can be measured using, for example, a DSC system (differential scanning calorimeter) ("Q-200" manufactured by TA Instruments). Specifically, the melting point and glass transition temperature of a 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, which is then placed on a holder unit and set in an electric furnace. Next, in a nitrogen atmosphere, the sample is heated from -80°C to 150°C at a heating rate of 10°C / min (first heating). Thereafter, the sample is cooled from 150°C to -80°C at a heating rate of 10°C / min, and further heated to 150°C at a heating rate of 10°C / min (second heating). During each of the first and second heatings, a DSC curve is measured using a differential scanning calorimeter ("Q-200" manufactured by TA Instruments). From the obtained DSC curves, the DSC curve at the first temperature rise can be selected using the analysis program in the Q-200 system, and the glass transition temperature (Tg) of the target sample at the first temperature rise can be determined. Similarly, the DSC curve at the second temperature rise can be selected, and the glass transition temperature (Tg) of the target sample at the second temperature rise can be determined.

[0103] Furthermore, the DSC curve obtained during the first heating run can be selected using the analysis program in the Q-200 system, and the endothermic peak top temperature during the first heating run of the target sample can be determined as the melting point. Similarly, the DSC curve during the second heating run can be selected, and the endothermic peak top temperature during the second heating run of the target sample can be determined as the melting point.

[0104] 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 constituent components such as a release agent are the endothermic peak top temperature and glass transition temperature (Tg) at the time of the second temperature rise, respectively, as the melting point and glass transition temperature (Tg) of each target sample.

[0105] [Average particle size, average circularity] The average particle size and average circularity can also be measured using, for example, a flow particle image analyzer (FPIA-3000, manufactured by Sysmex Corporation). Specifically, 0.1 to 0.5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of water from which solid impurities have been removed, and approximately 0.1 to 0.5 g of the sample to be measured is then added. The suspension containing the dispersed sample is subjected to a dispersion treatment using an ultrasonic disperser for approximately 1 to 3 minutes, and the dispersion concentration is adjusted to 3,000 particles / μl to 10,000 particles / μl. The average particle size and average circularity are measured using the flow particle image analyzer. The particle size is the equivalent circle diameter, and the average particle size is determined based on the equivalent circle diameter (number basis). The analysis conditions for the flow particle image analyzer are as follows: Particle size limit: 0.5 μm≦circle equivalent diameter (number basis)≦200.0 μm Particle shape limit: 0.93<circularity≦1.00 The average circularity is defined as follows. (Average circularity) = (perimeter of a circle equal to the projected area) / (perimeter of the projected image)

[0106] [Molecular weight measurement] 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 triple column (Tosoh Corporation) ·Temperature: 40℃ Solvent: THF ·Flow rate: 0.35mL / min Sample: 100 μL of 0.15% by mass sample injected Sample pretreatment: Resin particles are dissolved in tetrahydrofuran (THF) (containing stabilizers, manufactured by Wako Pure Chemical Industries, Ltd.) at 0.15% by mass, then filtered through a 0.2 μm filter. The filtrate is used as the sample. 100 μL of the THF sample solution is injected and measured.

[0107] When measuring the molecular weight of a sample, the molecular weight distribution of the sample is calculated from the relationship between the logarithm of the calibration curve prepared using several monodisperse polystyrene standard samples and the count number. The standard polystyrene samples used to prepare the calibration curve are Showdex STANDARD (Showa Denko K.K.), Std. Nos. S-7300, S-210, S-390, S-875, S-1980, S-10.9, S-629, S-3.0, and S-0.580. An RI (refractive index) detector is used.

[0108] <Method of manufacturing resin particles> A method for producing resin particles according to an embodiment will be described. The method for producing resin particles according to an 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 may further include other steps such as a shell formation step, a washing step, a drying step, an annealing step, and an external addition step, as necessary.

[0109] (Oil phase preparation process) In the oil phase preparation step, the raw materials for the resin particles, i.e., resin (amorphous resin, amorphous resin and crystalline resin, etc.), PET or PBT, and, if necessary, materials such as colorant, prepolymer (precursor of amorphous polyester resin A), wax, etc., are first dissolved or dispersed in an organic solvent to prepare the oil phase. Note that some of the materials may be added in the aggregation step described below.

[0110] The method for preparing the oil phase is not particularly limited and can be appropriately selected depending on the purpose. For example, a method in which raw materials such as a resin are gradually added to an organic solvent while stirring, and dissolved or dispersed therein, can be mentioned.

[0111] For dispersion, known dispersing machines such as a bead mill and a disk mill can be used.

[0112] The raw materials used in the oil phase preparation step can be those described above in the section on <Resin Particles>. These may be used alone or in combination of two or more.

[0113] The organic solvent is not particularly limited and 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 makes it easier to remove the organic solvent later.

[0114] 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 alone or in combination of two or more.

[0115] When the resin to be dissolved or dispersed in an organic solvent is a resin having a polyester skeleton, the organic solvent is preferably an ester solvent such as methyl acetate, ethyl acetate, or butyl acetate, or a ketone solvent such as methyl ethyl ketone or methyl isobutyl ketone, because of its high solubility. Among these, methyl acetate, ethyl acetate, or methyl ethyl ketone is preferred as the organic solvent, because of its high solvent removability.

[0116] The amount of organic solvent used is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 40 to 300 parts by mass, more preferably 60 to 140 parts by mass, and even more preferably 80 to 120 parts by mass per 100 parts by mass of the raw material for the resin particles.

[0117] (Aqueous phase preparation process) In the aqueous phase preparation step, an aqueous phase (aqueous medium) is prepared.

[0118] The aqueous medium is not particularly limited and can be appropriately selected from known aqueous media, and examples thereof include water, a water-miscible solvent, and a mixture thereof. From the viewpoint of granulation properties, the concentration of the water-miscible solvent is preferably equal to or lower than the saturation concentration of the ion-exchanged water used in the phase inversion emulsification step.

[0119] The water-miscible solvent is not particularly limited and can be appropriately selected from known solvents, such as alcohol, dimethylformamide, tetrahydrofuran, cellosolves, lower ketones, and esters.

[0120] Examples of alcohols include methanol, isopropanol, and ethylene glycol.

[0121] Examples of lower ketones include acetone and methyl ethyl ketone.

[0122] An example of the esters is ethyl acetate.

[0123] These may be used alone or in combination of two or more.

[0124] (Phase inversion emulsification process) In the phase inversion emulsification step, the oil phase obtained in the oil phase preparation step is atomized.

[0125] 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.

[0126] The phase inversion emulsification is carried out by stirring.

[0127] This is done by uniformly mixing and dispersing using a conventional stirrer or dispersing device.

[0128] The impeller is not particularly limited and can be appropriately selected depending on the viscosity of the solution. Examples include low-viscosity impellers such as paddles and propellers, medium-viscosity impellers such as anchors and maxblends, and high-viscosity impellers such as helical ribbons.

[0129] The dispersing device is not particularly limited, and examples thereof include an ultrasonic disperser, a bead mill, a ball mill, a roll mill, a homomixer, an ultra mixer, a disperser mixer, a penetrating type high-pressure dispersing device, a collision type high-pressure dispersing device, a porous type high-pressure dispersing device, an ultra-high-pressure homogenizer, an ultrasonic homogenizer, etc. A conventional stirrer and a dispersing device may be used in combination.

[0130] Among these, paddle and anchor are preferred in that they can control the volume average particle size of the dispersion (oil droplets) within the above-mentioned preferred range.

[0131] The base used to neutralize the oil phase may be either a basic inorganic compound or a basic organic compound. 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, tripropanolamine, tributanolamine, triethylamine, n-propylamine, n-butylamine, isopropylamine, monomethanolamine, morpholine, methoxypropylamine, pyridine, vinylpyridine, and isophoronediamine.

[0132] When using a stirring blade, the conditions such as the rotation speed, stirring time, and stirring temperature are not particularly limited and can be appropriately selected depending on the purpose.

[0133] The rotation speed is not particularly limited, but is preferably 100 rpm to 1,000 rpm, and more preferably 200 rpm to 600 rpm.

[0134] The stirring time and stirring temperature are not particularly limited and may be appropriately selected depending on the purpose.

[0135] A dispersant may also be used if necessary. The dispersant is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include surfactants, poorly water-soluble inorganic compound dispersants, and polymeric protective colloids. These may be used alone or in combination of two or more. Among these, surfactants are preferred.

[0136] The surfactant is not particularly limited and can be appropriately selected depending on the purpose. For example, anionic surfactants, cationic surfactants, nonionic surfactants, amphoteric surfactants, etc. can be used.

[0137] The anionic surfactant is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include alkylbenzene sulfonates, α-olefin sulfonates, phosphate esters, etc. Among these, those having a fluoroalkyl group are preferred.

[0138] (Desolvation process) In the solvent removal step, the organic solvent is removed from the resulting fine particle dispersion.

[0139] To remove the organic solvent from the resulting fine particle dispersion, a method can be employed in which the temperature of the entire system is gradually increased while being stirred, and the organic solvent in the droplets is completely evaporated and removed.

[0140] Alternatively, the organic solvent in the droplets can be completely removed by spraying the obtained microparticle dispersion into a dry atmosphere while stirring. Furthermore, the organic solvent can be evaporated and removed by reducing the pressure while stirring the microparticle dispersion. Alternatively, the organic solvent can be evaporated and removed by blowing a gas onto the microparticle dispersion while stirring it.

[0141] These means may be used alone or in combination.

[0142] The drying atmosphere in which the fine particle dispersion is sprayed is generally a gas such as air, nitrogen, carbon dioxide, or a heated combustion gas, particularly a gas stream heated to a temperature equal to or higher than the boiling point of the highest boiling point solvent used. The desired quality can be obtained by short-term processing using a spray dryer, belt dryer, rotary kiln, etc.

[0143] By removing the organic solvent from the fine particle dispersion obtained by the above method, a fine particle dispersion liquid can be obtained.

[0144] (Agglutination process) In the aggregation step, the obtained fine particle dispersion is agitated to aggregate particles of a desired particle size, thereby obtaining aggregated particles.

[0145] To achieve flocculation, existing methods such as adding a flocculant or adjusting the pH can be used. When adding a flocculant, it may be added directly, but it is preferable to use an aqueous solution of the flocculant, as this can prevent localized high concentrations. It is also preferable to add the flocculant gradually while monitoring the particle size of the fine particles.

[0146] The temperature of the dispersion during aggregation is preferably near the glass transition temperature Tg of the resin used. If the liquid temperature of the microparticle dispersion is too low, aggregation does not proceed very well, resulting in poor efficiency. If the liquid temperature of the microparticle dispersion is too high, the aggregation rate increases, resulting in the generation of coarse particles and a deterioration in particle size distribution.

[0147] When the target particle size is reached, aggregation is stopped by adding a salt or chelating agent with a low ionic valence, adjusting the pH, lowering the temperature of the dispersion, or adding a large amount of aqueous medium to dilute the concentration.

[0148] By the above method, a dispersion of resin particles can be obtained.

[0149] In the aggregation step, a colorant, a crystalline resin, and a release agent may be added. In this case, the material is mixed with a dispersion in which the material is dispersed in an aqueous medium or the fine particle dispersion, and then aggregated to obtain aggregated particles in which the colorant, the crystalline resin, and the release agent are uniformly dispersed.

[0150] In this embodiment, it is preferable to use a metal salt of Na with a low ionic valence. By substituting Na for the metal used as the flocculant, flocculation can be stopped efficiently.

[0151] ((flocculant)) As the flocculant, a general flocculant can be used, and one flocculant may be used alone, or two or more flocculants may be used in combination.

[0152] The metal ions function as a cross-linking agent that cross-links the ends of the resin.

[0153] 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.

[0154] In this embodiment, a divalent metal salt is preferred in order to obtain resin particles with a good particle size distribution.

[0155] Monovalent metals have a low crosslinking effect. Furthermore, when using biomass resin, amorphous resins with many aromatic ring structures, and PET or PBT resins, the structural differences are significant. Therefore, using a trivalent or higher metal salt with a fast crosslinking reaction rate results in poor particle size distribution of the resin particles. Among divalent metals, Mg exhibited particularly good aggregating properties. Metals used in flocculants, etc., can deteriorate electrostatic chargeability if they remain in the resin particles. Therefore, the amount of divalent metal elements in the resin particles is set to 0.05% to 1% by mass. When the amount of element in the resin particles is 0.05% by mass or more, the amount of metal used during aggregating is sufficient, providing sufficient coagulation force and preventing deterioration of particle size distribution. When the amount of element in the resin particles is 1% by mass or less, electrostatic chargeability can be achieved. The type and amount of metal in the resin particles can be adjusted by the type and amount of flocculant and terminator, and the washing conditions in the washing process.

[0156] (fusion process) In the fusion step, the resulting aggregated particles are fused by heat treatment to reduce irregularities and to form spherical particles. Fusion can be achieved by heating the dispersion of aggregated particles while stirring. The temperature of the dispersion is preferably near a temperature above the glass transition temperature (Tg) of the resin used.

[0157] (Shelling process) If necessary, shelling may be carried out (shelling step). In the shelling step, a shell layer is formed on the spheroidized particles obtained in the fusion step.

[0158] The method for forming the shell layer is not particularly limited and can be appropriately selected depending on the purpose. For example, the method for forming the shell layer includes a method in which spherical particles having a desired particle size are produced in a fusion step, and then an amorphous resin is added, and the shell layer is formed by repeating an aggregation step and a fusion step. In the present invention, it is preferred that the base particles have a core-shell structure, and the shell portion contains polyethylene terephthalate or polybutylene terephthalate.

[0159] (Washing and drying process) In the washing and drying step, only the resin particles are taken out from the resin particle dispersion obtained by the above method, washed, and dried.

[0160] The resin particle dispersion obtained by the above method contains secondary materials such as coagulated salts in addition to the resin particles, so washing is performed to extract only the resin particles from the dispersion. Methods for washing the resin particles include, but are not limited to, centrifugation, vacuum filtration, and filter press. While any of these methods produces a cake of resin particles, if the particles cannot be sufficiently washed in a single operation, the resulting cake may be dispersed again in an aqueous solvent to form a slurry, and the resin particles may be extracted by one of the above methods. Alternatively, if washing is performed by vacuum filtration or filter press, a method may be used in which the aqueous solvent is passed through the cake to wash away the secondary materials 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. However, water is preferred from the standpoints of cost and environmental impact due to wastewater treatment.

[0161] The washed resin particles contain a large amount of the aqueous medium, so the resin particles can be obtained by drying them to remove the aqueous medium.

[0162] Drying methods that can be used include dryers such as spray dryers, vacuum freeze dryers, reduced-pressure dryers, stationary shelf dryers, mobile shelf dryers, fluidized bed dryers, rotary dryers, and agitator dryers. The dried resin particles are preferably dried until the final moisture content is less than 1%. If the dried colored resin particles are in the form of soft agglomerates that cause inconvenience during use, they may be crushed using a device such as a jet mill, Henschel mixer, super mixer, coffee mill, Oster blender, or food processor to loosen the agglomerates.

[0163] (Annealing process) In the annealing process, when a crystalline resin is added, annealing after drying causes phase separation between the amorphous resin and the crystalline resin, improving fixability. Specifically, the toner is stored at a temperature near the glass transition temperature (Tg) for 10 hours or more.

[0164] The base particles of the resin particles obtained as described above have a BET specific surface area of ​​0.8 to 1.4 m 2 / g. The BET specific surface area is preferably 0.8 m 2 / g or more is advantageous in terms of charge control, and the BET specific surface area is 1.4 m 2 / g or less is advantageous in terms of fluidity and cleaning properties. 2 The BET specific surface area can be adjusted by adjusting the temperature and time of the fusion step in the particle production process. The BET specific surface area can be measured, for example, using an automatic specific surface area / pore size distribution analyzer (TriStar3000, manufactured by Shimadzu Corporation). Specifically, approximately 0.5 g of toner is weighed into a sample cell and vacuum-dried for 24 hours using a pretreatment SmartPrep (manufactured by Shimadzu Corporation) to remove impurities and moisture from the sample surface. The pretreated sample is placed in the automatic specific surface area / pore size distribution analyzer (TriStar3000, manufactured by Shimadzu Corporation), and the relationship between the nitrogen gas adsorption amount and the relative pressure is determined. From the relationship between the nitrogen gas adsorption amount and the relative pressure, the BET specific surface area of ​​the toner is determined by the BET multipoint method.

[0165] (External addition process) To the base particles of the obtained resin particles, external additives may be attached in order to impart fluidity, chargeability, cleanability, etc., and other additives, such as wax, colorant, charge control agent, and cleanability improver, may also be added and mixed. Specific mixing methods include a method in which an impact force is applied to the mixture using blades rotating at high speed, and a method in which the mixture is introduced into a high-speed air current, accelerated, and the particles or composite particles are caused to collide with an appropriate collision plate.

[0166] Examples of equipment include an Ang Mill (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 Machinery Works, Ltd.), a Cryptron System (manufactured by Kawasaki Heavy Industries, Ltd.), and an automatic mortar.

[0167] The resin particles according to one embodiment contain a radioactive carbon isotope. 14 It is preferable that the carbon concentration is 10.8 pMC or more, and that the resin particles contain 0.05% to 1% by mass of a divalent metal element, excluding external additives. By including PET or PBT, the resin particles according to one embodiment can improve environmental friendliness even when a biomass-derived resin is included instead of a petroleum-derived resin, while reducing the impact of structural differences in the biomass-derived resin on the resin particle properties. Furthermore, by including 0.05% to 1% by mass of a divalent metal element, the resin particles according to one embodiment can be agglomerated mildly when a metal salt is used to agglomerate the resin particles during production, thereby producing resin particles with a good particle size distribution.

[0168] Therefore, the resin particles according to one embodiment can reduce the environmental load, have an excellent particle size distribution, and form an image with excellent image quality.

[0169] Resin particles according to one embodiment contain at least one of an amorphous resin, an amorphous resin, and a crystalline resin, wherein at least one of the amorphous resin, the amorphous resin, and the crystalline resin comprises a biomass-derived resin, and the total content of the biomass-derived resin and PET or PBT relative to the total mass of the resin particles can be 50% by mass or more. This allows the resin particles according to one embodiment to contain a biomass-derived resin, thereby enhancing environmental friendliness, and reliably reducing the impact on the properties of the resin particles due to the structural differences between the biomass-derived resin and petroleum-derived resin. Therefore, the resin particles according to one embodiment can improve the particle size distribution while reducing the environmental impact, and can more consistently provide high-quality images.

[0170] The resin particles according to an embodiment may contain more PET or PBT than the biomass-derived resin, thereby further reducing the influence of the structural difference between the biomass-derived resin and the petroleum-derived resin on the properties of the resin particles.

[0171] The resin particles according to one embodiment may contain 0.1% by mass to 0.5% by mass of magnesium among the divalent metal elements, which allows the resin particles according to one embodiment to more reliably and mildly aggregate when a metal salt is used to aggregate the resin particles during production of the resin particles, thereby ensuring the production of resin particles with an even better particle size distribution.

[0172] The resin particles according to one embodiment contain sodium, and among divalent metal elements, the magnesium content is greater than the sodium content, and the sodium content can be set to more than 0.05% by mass. This allows for milder aggregation of the resin particles when a metal salt is used to aggregate the resin particles during production, thereby ensuring the production of resin particles with an even better particle size distribution.

[0173] The resin particles according to one embodiment have the above-described properties, and therefore can be effectively used as a material for image formation, such as a toner, a developer, a toner set, a toner storage unit, and an image forming apparatus.

[0174] <Toner> The toner according to an embodiment includes the resin particles according to an embodiment, and may be made of the resin particles according to an embodiment.

[0175] By using the resin particles according to one embodiment in a toner, the environmental impact can be reduced, and even if a plant-derived resin is used, it is possible to provide an image having excellent low-temperature fixability and chargeability, and excellent image quality.

[0176] <Developer> The developer according to an embodiment includes the toner according to an embodiment, and may optionally include other appropriately selected components such as a carrier, etc. This allows for excellent transferability, chargeability, etc., and enables stable formation of high-quality images.

[0177] The developer may be a one-component developer or a two-component developer, but when used in high-speed printers that correspond to the recent improvements in information processing speed, a two-component developer is preferable in terms of extending the developer life.

[0178] When the toner according to one embodiment is used in a one-component developer, even if the toner is balanced, there is little variation in the particle size of the toner, and toner filming on the developing roller and toner fusion to components such as blades that thin the toner layer are minimized, resulting in high-quality images being obtained in the developing device.

[0179] When the developer according to an embodiment is used as a two-component developer, it can be mixed with a carrier and used as a developer. When the toner according to an embodiment is used as a two-component developer, the particle size of the toner changes little even when the toner is balanced over a long period of time, and good and stable developability and images can be obtained even when the toner is stirred for a long period of time in a developing device. The development method may be a premix development method, in which a premix developer in which toner and carrier are mixed in advance is replenished. In the premix development method, the excess carrier in the developing device is discharged as excess developer. This gradually refreshes the developer in the developing device. This can extend the replacement cycle due to developer deterioration and eliminate the effort required for developer replacement.

[0180] The content of the carrier in the two-component developer can be appropriately selected depending on the purpose, but is preferably 90 to 98 parts by mass, and more preferably 93 to 97 parts by mass, relative to 100 parts by mass of the two-component developer.

[0181] The developer according to one embodiment can be suitably used for image formation by various known electrophotographic methods such as a magnetic one-component development method, a non-magnetic one-component development method, and a two-component development method.

[0182] [Career] The carrier is not particularly limited and can be appropriately selected depending on the purpose, but it is preferable that the carrier has a core material and a resin layer (coating layer) that coats the core material.

[0183] (Core material) The core material is not particularly limited and can be selected appropriately depending on the purpose. Examples include manganese-strontium-based materials with a density of 50 emu / g to 90 emu / g and manganese-magnesium-based materials with a density of 50 emu / g to 90 emu / g. To ensure image density, it is preferable to use high-magnetization materials such as iron powder with a density of 100 emu / g or more, or magnetite with a density of 75 emu / g to 120 emu / g. It is also preferable to use low-magnetization materials such as copper-zinc-based materials with a density of 30 emu / g to 80 emu / g, as this can reduce the impact of the developer in a standing state on the photoreceptor and is advantageous for achieving high image quality. These materials may be used alone or in combination of two or more.

[0184] The volume average particle diameter of the core material is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 10 μm to 150 μm, and more preferably 40 μm to 100 μm. If the volume average particle diameter is 10 μm or more, the amount of fine powder in the carrier increases, which effectively prevents the problem of reduced magnetization per particle and carrier scattering. On the other hand, if the volume average particle diameter is 150 μm or less, the specific surface area decreases, which can cause toner scattering, effectively preventing the problem of poor reproduction of solid areas, especially in full-color printers with many solid areas.

[0185] (resin layer) The resin layer can contain a resin and, if necessary, other components. The resin used in the resin layer can be a known material that can impart the necessary electrostatic property. Specifically, it is preferable to use a silicone resin, an acrylic resin, or a combination of these. Furthermore, it is preferable that the composition for forming the resin layer contains a silane coupling agent.

[0186] The average thickness of the resin layer is preferably 0.05 to 0.50 μm.

[0187] <Developer container> The developer storage container according to an embodiment stores the developer according to an embodiment. The developer storage container is not particularly limited and can be appropriately selected from known containers, and examples thereof include a container having a container body and a cap.

[0188] Furthermore, the size, shape, structure, material, etc. of the container body are not particularly limited, but the shape is preferably cylindrical or the like, and spiral irregularities are formed on the inner peripheral surface so that the developer contained therein can be transferred to the discharge port side by rotating it, and it is particularly preferred that part or all of the spiral irregularities have a bellows function. Furthermore, the material is not particularly limited, but is preferably one with good dimensional accuracy, and examples thereof include resin materials such as polyester resin, polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, polyacrylic acid, polycarbonate resin, ABS resin, and polyacetal resin.

[0189] The developer storage container is easy to store, transport, and handle, and can be detachably attached to an image forming apparatus, a process cartridge, or the like, which will be described later, and used to replenish the developer.

[0190] <Toner storage unit> The toner storage unit according to an embodiment can store the toner according to an embodiment. The toner storage unit according to an embodiment refers to a unit that stores toner in a unit having a function of storing toner. Here, examples of the toner storage unit include a toner storage container, a developing unit, and a process cartridge.

[0191] The toner container refers to a container that stores toner.

[0192] The developing device is a device that contains toner and has means for developing.

[0193] A process cartridge is a device that integrates at least an electrostatic latent image carrier (also called an image carrier) and a developing means, contains toner, and is detachably mountable to 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.

[0194] The toner storage unit according to the embodiment stores the toner according to the embodiment. By mounting the toner storage unit according to the embodiment in an image forming apparatus and forming an image using the toner according to the embodiment, it is possible to obtain a toner that has excellent low-temperature fixing properties and chargeability, and has high image quality.

[0195] <Image forming device> 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 with toner to form a toner image, and may further include other components as necessary.

[0196] More preferably, the image forming apparatus according to one embodiment includes, in addition to the electrostatic latent image carrier, electrostatic latent image forming unit, and developing unit described above, a transfer unit that transfers the toner image onto a recording medium, and a fixing unit that fixes the transferred image onto the surface of the recording medium.

[0197] In the developing section, a toner according to an embodiment is used. Preferably, a developer containing the toner according to an embodiment and, if necessary, other components such as a carrier may be used to form a toner image.

[0198] (Electrostatic latent image carrier) The electrostatic latent image carrier is not particularly limited in structure, size, etc., and can be appropriately selected from known ones. The shape of the image carrier is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include a drum shape and a belt shape. The material of the image carrier is not particularly limited and can be appropriately selected depending on the purpose, and examples thereof include inorganic photoconductors such as amorphous silicon and selenium, and organic photoconductors (OPCs) such as polysilane and phthalopolymethine.

[0199] Examples of the organic photoreceptor include a laminated photoreceptor having a laminated structure in which a layer (charge generation layer) in which a charge generation material such as metal-free phthalocyanine or titanyl phthalocyanine is dispersed in a binder resin and a layer (charge transport layer) in which a charge transport material is dispersed in a binder resin are stacked on a support such as an aluminum drum, and a single-layer photoreceptor having a single-layer photosensitive layer in which both a charge generation material and a charge transport material are dispersed in a binder resin on a support. In the single-layer type photoreceptor, a hole transport material and an electron transport material can be added to the photosensitive layer as charge transport materials. An undercoat layer may be provided between the support and the multilayer charge generating layer or the single-layer photosensitive layer.

[0200] The shape of the electrostatic latent image carrier is not particularly limited and can be appropriately selected depending on the purpose, but a cylindrical shape is preferred.The outer diameter of the cylindrical electrostatic latent image carrier is not particularly limited and can be appropriately selected depending on the purpose, but is preferably 3 mm to 100 mm, more preferably 5 mm to 50 mm, and particularly preferably 10 mm to 30 mm.

[0201] (Electrostatic latent image formation unit) 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 depending on 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 imagewise exposes the surface of the electrostatic latent image carrier.

[0202] The charger is not particularly limited and can be appropriately selected depending on the purpose. Examples include contact chargers equipped with a conductive or semiconductive roll, brush, film, rubber blade, etc., and non-contact chargers that utilize corona discharge such as corotrons and scorotrons.

[0203] The shape of the charger may be a roller, a magnetic brush, a fur brush, or any other shape, and can be selected according to the specifications and shape of the image forming apparatus.

[0204] The charger is preferably one that is arranged in contact or non-contact with the electrostatic latent image carrier and charges the surface of the electrostatic latent image carrier by applying a superimposed DC and AC voltage to it. Also, the charger is preferably a charging roller that is arranged in close proximity to the electrostatic latent image carrier but not in contact with it via a gap tape and that charges the surface of the electrostatic latent image carrier by applying a superimposed DC and AC voltage to the charging roller.

[0205] The charger is not limited to a contact type charger, but it is preferable to use a contact type charging member because it allows for an image forming apparatus in which ozone generated from the charger is reduced.

[0206] The exposure device is not particularly limited as long as it can expose the surface of the electrostatic latent image carrier charged by the charger in the shape of an image to be formed, and can be appropriately selected depending on the purpose. Examples of the exposure device include various exposure devices such as a copying optical system, a rod lens array system, a laser optical system, and a liquid crystal shutter optical system.

[0207] The light source used in the exposure device is not particularly limited and can be appropriately selected depending on the purpose. Examples include fluorescent lamps, tungsten lamps, halogen lamps, mercury lamps, sodium lamps, light-emitting diodes (LEDs), semiconductor lasers (LDs), electroluminescence (EL), and other light-emitting materials in general.

[0208] In order to irradiate only light in a desired wavelength range, various filters such as a sharp cut filter, a band pass filter, a near infrared cut filter, a dichroic filter, an interference filter, and a color temperature conversion filter can be used.

[0209] The exposure unit may employ a backlight system in which imagewise exposure is performed from the back side of the electrostatic latent image carrier.

[0210] (development section) 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 depending on the purpose. For example, the developing unit can be suitably used one that includes a developing unit that stores toner and can apply the toner to the electrostatic latent image in a contact or non-contact manner, and a developing unit that includes a toner container is preferred.

[0211] The developing device may be a single-color developing device or a multi-color developing device. Suitable examples of the developing device include a developing device having an agitator that frictionally agitates toner to charge it, a magnetic field generating unit fixed inside, and a rotatable developer carrier (e.g., a magnet roller) that carries developer containing toner on its surface.

[0212] (Transfer section) The transfer unit preferably has a first transfer unit that transfers a visible image onto an intermediate transfer body to form a composite transfer image, and a second transfer unit that transfers the composite transfer image onto a recording medium. The intermediate transfer body is not particularly limited and can be appropriately selected from known transfer bodies depending on the purpose, and a transfer belt or the like is suitable, for example.

[0213] The transfer section (primary transfer means and secondary transfer section) preferably has at least a transfer device that peels and charges the visible image formed on the electrostatic latent image carrier (photosensitive member) onto the recording medium. The number of transfer sections may be one or two or more.

[0214] Examples of the transfer device include a corona transfer device using corona discharge, a transfer belt, a transfer roller, a pressure transfer roller, and an adhesive transfer device.

[0215] The recording medium is typically plain paper, but there are no particular restrictions as long as it is capable of transferring the unfixed image after development, and it can be selected appropriately from known recording media (recording paper) depending on the purpose, and a PET base for an overhead projector can also be used.

[0216] (fixing part) The fixing unit is not particularly limited and can be appropriately selected depending on the purpose, but a known heating and pressurizing unit is suitable. Examples of the heating and pressurizing unit include a combination of a heating roller and a pressure roller, and a combination of a heating roller, a pressure roller and an endless belt.

[0217] The fixing section is preferably a heating and pressurizing section that has a heating element having a heat generating element, a film that contacts the heating element, and a pressure member that is pressed against the heating element via the film, and that can heat and fix a recording medium on which an unfixed image has been formed by passing it between the film and the pressure member.

[0218] The heating temperature in the heating and pressurizing section is usually preferably 80°C to 200°C.

[0219] The surface pressure in the heating and pressing section is not particularly limited and can be selected appropriately depending on the purpose, but is preferably 10 N / cm 2 ~80N / cm 2 It is preferable that:

[0220] In this embodiment, depending on the purpose, for example, a known optical fixing device may be used together with or instead of the fixing unit.

[0221] (others) The image forming apparatus according to the first embodiment may further include, for example, a static eliminator, a cleaning unit, a recycling unit, a control unit, and the like.

[0222] ((Static eliminator)) The charge removal unit is not particularly limited as long as it can apply a charge removal bias to the electrostatic latent image bearing member, and can be appropriately selected from known charge removal devices, and a suitable example is a charge removal lamp.

[0223] ((Cleaning section)) The cleaning unit may be any cleaner capable of removing toner remaining on the electrostatic latent image carrier, and may be appropriately selected from known cleaners, such as a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, a brush cleaner, and a web cleaner.

[0224] The image forming apparatus according to the first embodiment has a cleaning unit, which improves cleaning performance. Specifically, by controlling the inter-toner adhesion, the fluidity of the toner is controlled, improving cleaning performance. Furthermore, by controlling the properties of the deteriorated toner, excellent cleaning quality can be maintained even under harsh conditions such as extended life and high temperature and humidity. Furthermore, since the external additives can be sufficiently liberated from the toner on the photoreceptor, a deposition layer (dam layer) of the external additives can be formed in the cleaning blade nip, thereby achieving high cleaning performance.

[0225] (Recycling Department) The recycling section is not particularly limited, and examples thereof include known conveying means.

[0226] ((Control Unit)) The control unit can control the movement of each of the above-mentioned units. The control unit is not particularly limited as long as it can control the movement of each of the above-mentioned units, and can be appropriately selected depending on the purpose. Examples of the control unit include control devices such as a sequencer and a computer.

[0227] The image forming apparatus according to one embodiment can form images using the toner according to one embodiment, thereby reducing power consumption and providing high-quality images stably.

[0228] <Image forming method> An image forming method according to one embodiment includes an electrostatic latent image forming step of forming an electrostatic latent image on an electrostatic latent image carrier, and a developing step of developing the electrostatic latent image with toner to form a toner image, and may further include other steps as necessary. The image forming method can be suitably performed by the image forming apparatus, the electrostatic latent image forming step can be suitably performed by the electrostatic latent image forming unit, the developing step can be suitably performed by the developing unit, and the other steps can be suitably performed by the other units.

[0229] Furthermore, the image forming method according to one embodiment more preferably includes, in addition to the electrostatic latent image forming process and the developing process, a transfer process of transferring the toner image onto a recording medium, and a fixing process of fixing the transferred image onto the surface of the recording medium.

[0230] In the developing step, the toner according to one embodiment is used. Preferably, a developer containing the toner according to one embodiment and, if necessary, other components such as a carrier may be used to form a toner image.

[0231] The electrostatic latent image forming process is a process of forming an electrostatic latent image on an electrostatic latent image carrier, and includes a charging process of charging the surface of the electrostatic latent image carrier and an exposure process of exposing the charged surface of the electrostatic latent image carrier to light 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 imagewise exposing the surface of the electrostatic latent image carrier using the exposure device. The electrostatic latent image can be formed, for example, by uniformly charging the surface of the electrostatic latent image carrier and then imagewise exposing it, and this can be performed by an electrostatic latent image forming unit.

[0232] The developing step is a step of sequentially developing the electrostatic latent image with toners of multiple colors to form a visible image. The formation of the visible image can be carried out, for example, by developing the electrostatic latent image with the toners, using a developing device.

[0233] In the developing unit, for example, toner and carrier are mixed and stirred, and the friction caused by this causes the toner to become charged and be held in a standing state on the surface of the rotating magnet roller, forming a magnetic brush. Because the magnet roller is located near an electrostatic latent image carrier (photosensitive member), some of the toner constituting the magnetic brush formed on the surface of the magnet roller moves to the surface of the electrostatic latent image carrier (photosensitive member) by electrical attraction. As a result, the electrostatic latent image is developed with toner, and a visible toner image is formed on the surface of the electrostatic latent image carrier (photosensitive member).

[0234] The transfer step is a step of transferring a visible image to a recording medium. A preferred embodiment of the transfer step is to use an intermediate transfer member, perform primary transfer of the visible image onto the intermediate transfer member, and then perform secondary transfer of the visible image onto the recording medium. A more preferred embodiment of the transfer step is to use toner of two or more colors, preferably full-color toner, and include a primary transfer step of transferring the visible image onto the intermediate transfer member to form a composite transfer image, and a secondary transfer step of transferring the composite transfer image onto the recording medium. Transfer can be performed, for example, by charging an electrostatic latent image carrier (photosensitive member) with a transfer charger, and can be performed in a transfer section.

[0235] The fixing process is a process in which the visible image transferred to the recording medium is fixed using a fixing device, and may be performed for each color developer each time it is transferred to the recording medium, or may be performed simultaneously for each color developer in a stacked state.

[0236] The image forming method according to the first embodiment may further include other steps appropriately selected as necessary, such as a static elimination step, a cleaning step, a recycling step, and the like.

[0237] The charge removal step is a step of removing static electricity by applying a charge removal bias to the electrostatic latent image bearing member, and can be suitably performed by the charge removal unit.

[0238] The cleaning step is a step of removing the toner remaining on the electrostatic latent image carrier, and can be suitably carried out by a cleaning unit.

[0239] The recycling step is a step in which the toner removed in the cleaning step is recycled to the developing unit, and can be suitably carried out by the recycling unit.

[0240] The image forming method according to one embodiment can form an image using the toner according to one embodiment, thereby reducing power consumption and providing high-quality images stably.

[0241] Here, an image forming apparatus according to the present invention will be described with reference to the drawings. Note that the present invention is not limited to the following embodiments, and other modifications, additions, corrections, deletions, and other changes can be made within the scope of what one skilled in the art can conceive. Any embodiment is within the scope of the present invention as long as it achieves the functions and effects of the present invention.

[0242] One embodiment of a method for forming an image using an image forming apparatus of the present invention will be described with reference to Fig. 1. Although a printer is shown as an example of the image forming apparatus of 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 in a copier, facsimile, multifunction machine, or the like.

[0243] FIG. 1 is a schematic diagram showing an example of an image forming apparatus according to the present invention. The image forming apparatus includes a paper feed unit 210 , a conveying unit 220 , an image forming unit 230 , a transfer unit 240 , and a fixing unit 250 . The paper feed section 210 includes a paper feed cassette 211 in which paper sheets P to be fed are stacked, and a paper feed roller 212 that feeds the paper sheets P stacked in the paper feed cassette 211 one by one.

[0244] The conveying section 220 includes a roller 221 that conveys the paper P fed by the paper feed roller 212 toward the transfer section 240, a pair of timing rollers 222 that hold the leading end of the paper P conveyed by the roller 221 and wait, sending the paper to the transfer section 240 at a predetermined timing, and a paper discharge roller 223 that discharges the paper P with the fixed color toner image onto a paper discharge tray 224.

[0245] The image forming section 230 includes, at predetermined intervals from left to right in FIG. 1, an image forming unit 180Y that forms an image using a developer containing yellow toner, an image forming unit 180C that uses a developer containing cyan toner, an image forming unit 180M that uses a developer containing magenta toner, an image forming unit 180K that uses a developer containing black toner, and an exposure device 233.

[0246] The image forming unit 180 (180Y, 180C, 180M, 180K) is arranged to be 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, chargers 232 (232Y, 232C, 232M, 232K) that uniformly charge the surface of the photosensitive drum 231 (231Y, 231C, 231M, 231K), and cleaners 236 (236Y, 236C, 236M, 236K) that remove toner remaining on the surface of the photosensitive drum 231 (231Y, 231C, 231M, 231K).

[0247] The image forming units 180 (180Y, 180C, 180M, 180K) are equipped with toner bottles 234 (234Y, 234C, 234M, 234K) that contain toner of each color, and sub-hoppers 160 (160Y, 160C, 160M, 160K) that replenish the toner supplied from the toner bottles 234 (234Y, 234C, 234M, 234K).

[0248] It should be noted that when referring to any one of the image forming units 180 (180Y, 180C, 180M, 180K), it will be referred to as the image forming unit.

[0249] The exposure device 233 irradiates the photosensitive drum 231 with laser light L emitted from a light source 233a based on image information, by reflecting the light on a polygon mirror 233b (233bY, 233bC, 233bM, 233bK) that is driven to rotate by a motor. The developer contains toner and carrier. The four image forming units 180 (180Y, 180C, 180M, 180K) have substantially the same mechanical configuration, except for the developer used therein.

[0250] 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 as the drive roller 241 is driven, primary transfer rollers 244 (244Y, 244C, 244M, 244K) that are arranged opposite the photosensitive drums 231 (231Y, 231C, 231M, 231K) across the intermediate transfer belt 243, and secondary opposing rollers 245 and 246 that are arranged opposite each other across the intermediate transfer belt 243 at the position where the toner image is transferred to the paper. In this embodiment, an elastic intermediate transfer belt can also be used as the intermediate transfer belt 243. As the elastic intermediate transfer belt, for example, one in which a flexible elastic layer is laminated on a rigid base layer that can provide relatively flexibility can be used. In order to prevent the intermediate transfer belt 243 from meandering, a guide member for preventing the intermediate transfer belt 243 from shifting may be provided on the inner peripheral surface of the intermediate transfer belt 243 .

[0251] The fixing device 250 has a heater installed inside and includes a pressure roller 252 that forms a nip by rotatably pressing a fixing belt 251 that heats the paper P against the fixing belt 251. This applies heat and pressure to the color toner image on the paper P, fixing the color toner image. The paper P on which the color toner image has been fixed is discharged onto a paper discharge tray 224 by a paper discharge roller 223, completing a series of image forming processes.

[0252] 2 shows an example of a process cartridge as an example of a toner storage container according to the present invention. The process cartridge 110 has a photosensitive drum 10, a corona charger 58, a developing device 40, a transfer roller 80, and a cleaning device 90. An electrostatic latent image is formed on the photosensitive drum 10 by exposure light L. The image is formed on recording paper 95 by the process cartridge 110 according to the present invention. [Example]

[0253] Hereinafter, the embodiment will be described in more detail with reference to examples and comparative examples, but the embodiment is not limited to these examples and comparative examples.

[0254] <Production Example A-1: ​​Synthesis of Amorphous Polyester Resin A-1> -Synthesis of Prepolymer A-1- 3-methyl-1,5-pentanediol, isophthalic acid, and plant-derived sebacic acid were added to a reaction vessel equipped with a condenser, stirrer, and nitrogen inlet tube, along with titanium tetraisopropoxide (1,000 ppm relative to the resin component) so that the hydroxyl to carboxyl molar ratio (OH / COOH) was 1.1, the diol component was 100 mol% 3-methyl-1,5-pentanediol, the dicarboxylic acid component was 73 mol% isophthalic acid and 23 mol% sebacic acid, and the amount of trimethylolpropane in the total monomers was 1.5 mol%. The mixture was then heated to 200°C over approximately 4 hours, then to 230°C over 2 hours, and the reaction was continued until no water was discharged. The mixture was then further reacted for 5 hours under a reduced pressure of 10 to 15 mmHg to obtain [Intermediate Polyester A-1].

[0255] 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, diluted with ethyl acetate to make a 50% ethyl acetate solution, and reacted at 150°C for 4 hours to obtain [Prepolymer A-1].

[0256] -Synthesis of amorphous polyester resin A-1- The resulting [Prepolymer A-1] was stirred in a reaction vessel equipped with a heater, stirrer, and nitrogen inlet tube. Further, [Ketimine Compound 1] was added dropwise to the reaction vessel in an amount such that the amine content of [Ketimine Compound 1] was equimolar to the isocyanate content of [Prepolymer A-1]. After stirring at 45°C for 10 hours, the prepolymer elongated product was removed. The resulting prepolymer elongated product was dried under reduced pressure at 50°C until the residual ethyl acetate content was 100 ppm or less, yielding [Amorphous Polyester Resin A-1]. The resulting [Amorphous Polyester Resin A-1] had a glass transition temperature (Tg) of -51°C and a weight average molecular weight (Mw) of 17,000. Ketimine Compound 1 was obtained by charging 170 parts by mass of isophoronediamine and 75 parts by mass of methyl ethyl ketone into a reaction vessel equipped with a stirring rod and a thermometer, and reacting them at 50°C for 5 hours.

[0257] <Synthesis of amorphous polyester resin B-1> In a four-neck flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple, bisphenol A ethylene oxide 2-mol adduct, bisphenol A propylene oxide 2-mol adduct, terephthalic acid, and adipic acid were added to form a mixture in which the bisphenol A propylene oxide 2-mol adduct and the bisphenol A ethylene oxide 2-mol adduct were mixed in a molar ratio of 60 / 40 (bisphenol A propylene oxide 2-mol adduct / bisphenol A ethylene oxide 2-mol adduct), and the terephthalic acid and adipic acid were mixed. The mixture was charged with terephthalic acid and adipic acid in a molar ratio (terephthalic acid / adipic acid) of 97 / 3, with a hydroxyl to carboxyl group molar ratio of OH / COOH of 1.3, and reacted with titanium tetraisopropoxide (500 ppm based on the resin components) at atmospheric pressure and 230°C for 8 hours. After further reaction at a reduced pressure of 10-15 mmHg for 4 hours, trimellitic anhydride was added to the reaction vessel in an amount of 1 mol% based on the total resin components, and the reaction was continued at 180°C and atmospheric pressure for 4 hours to obtain [Amorphous Polyester Resin B-1]. The resulting [Amorphous Polyester Resin B-1] had a glass transition temperature (Tg) of 65°C and a weight average molecular weight (Mw) of 9000.

[0258] <P-1: Introduction of PET> The flaky recycled PET (P-1) was mixed so that the proportion of solids shown in Table 1 was obtained when mixing the materials.

[0259] <Synthesis of Crystalline Polyester Resin C-1> Sebacic acid and ethylene glycol were charged into a 5L four-necked flask equipped with a nitrogen inlet tube, a water removal tube, a stirrer, and a thermocouple so that the molar ratio of hydroxyl group to carboxyl group, OH / COOH, was 0.9. Together with titanium tetraisopropoxide (500 ppm with respect to the resin components), the reaction was carried out 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.

[0260] <Production of Crystalline Polyester Resin Dispersion C-1> 45 parts by mass of [Crystalline Polyester Resin C-1] and 450 parts by mass of ethyl acetate were charged into a container equipped with a stirrer bar and a thermometer, heated to 80 °C under stirring, held at 80 °C for 5 hours, then cooled to 30 °C in 1 hour, and dispersed using a bead mill (Ultraviscomill, manufactured by Imex Co., Ltd.) under the conditions of a liquid feeding 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%.

[0261] <Production of Polyester Resin SR for Shell> A reaction vessel equipped with a condenser, a stirrer, and a nitrogen inlet tube was charged with 7.5 parts by mass of adipic acid, 63.5 parts by mass of terephthalic acid, and 4.8 parts by mass of succinic acid as acid monomers, and 35.5 parts by mass of Bis-A-EO 2-mol adduct, 58.2 parts by mass of Bis-A-PO 2-mol adduct, 23.4 parts by mass of 1,2-propanediol, and 1 part by mass of trimethylolpropane as alcohol monomers, so that the molar ratio of hydroxyl groups to carboxylic acid (OH / COOH) was 1.2. Further, 1,000 ppm of tetrabutoxy titanate, relative to the total amount of monomers, was added as a condensation catalyst. The temperature was raised to 200°C over 2 hours under a nitrogen stream, and then further raised to 230°C over 8 hours, and the reaction was carried out for 5 hours while the produced water was distilled off. The mixture was then reacted for 1 hour under a reduced pressure of 5-15 mmHg and cooled to 200°C. Then, 4.5 parts by mass of trimellitic anhydride was added and the mixture was reacted for 1 hour at 200°C under normal pressure. The mixture was then further reacted under a reduced pressure of 5-20 mmHg until the desired molecular weight was reached, yielding [Shell Polyester Resin SR]. The recycled PET flakes were mixed with the acid monomer and alcohol monomer materials to make up 30% of the solids. <Preparation of Polyester Resin Solution for Shell> 200 parts of [shell polyester resin SR] and 200 parts of methyl ethyl ketone were placed in a container and mixed for 60 minutes at 5,000 rpm using a TK Homomixer (manufactured by Primix Corporation) to obtain [shell polyester resin solution 1]. The solids concentration of the obtained [shell polyester resin solution 1] was 50%.

[0262] <<Calculation method for solid concentration of polyester resin solution for shell>> The solids concentration of [Shell polyester resin solution 1] was calculated using the following formula from the remaining amount after accurately weighing 0.9000 g to 1.0000 g of [Shell polyester resin solution] into an aluminum container and leaving it to stand in a thermostatic bath with an internal temperature set to 150°C for 1 hour and then removing it from the thermostatic bath. Solid content [%] = (amount remaining after standing at 150°C for 1 hour [g]) / (precisely weighed amount of [shell resin solution 1]) × 100

[0263] <Preparation of Shell Aqueous Phase 1> 468 parts of water and 132 parts of methyl ethyl ketone were mixed and stirred to obtain a white transparent liquid. This was designated as [Shell Aqueous Phase 1].

[0264] <Preparation of Polyester Resin Emulsion SR for Shell> 400 parts of the solution of [Polyester Resin Solution 1 for Shell] was stirred with a TK homomixer (manufactured by Primix Corporation) at a rotational speed of 8,000 rpm, and 28% aqueous ammonia was added in an amount equivalent to 100% of the acid value of [Resin SR for Polyester Resin Emulsion] while stirring. After mixing for 10 minutes, 600 parts of [Shell Aqueous Phase 1] was gradually added dropwise to invert and emulsify [Polyester Resin Solution 1 for Shell]. Further, the inverted emulsion of [Polyester Resin Solution 1 for Shell] was desolvated with an evaporator to obtain [Polyester Resin Emulsion SR for Shell].

[0265] <Preparation of WAX Dispersion 1> 720 parts by mass of ion-exchanged water was added with 180 parts by mass of ester wax (manufactured by NOF CORPORATION, WE-11, synthetic wax of plant-derived monomer, 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. This was heated to 90°C while being dispersed with 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%.

[0266] <Preparation of Master Batch (MB) 1> 1200 parts by mass of water, 500 parts by mass of carbon black (Printex 35, manufactured by Degussa AG) [DBP oil absorption amount = 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 using two rolls, then rolled and cooled and pulverized with a pelletizer to obtain [Master Batch 1].

[0267] <Production of resin particles> [Example 1] (Oil phase preparation step) 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], 300 parts by mass of [P-1], 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 Corporation) to obtain [oil phase 1]. The above blending amounts indicate the solid content of each raw material.

[0268] (Aqueous phase preparation step) 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, which was designated as [aqueous phase 1].

[0269] (Emulsified slurry manufacturing process) 700 parts by mass of [Oil Phase 1] was stirred at 8,000 rpm using a TK Homomixer, and 20 parts by mass of 28% aqueous ammonia was added. After mixing for 10 minutes, 1,200 parts by mass of [Aqueous Phase 1] was gradually added dropwise to obtain [Emulsified Slurry 1].

[0270] (Production process of solvent-free slurry) [Emulsified slurry 1] was placed in a container equipped with a stirrer and a thermometer, and the solvent was removed at 30° C. for 180 minutes to obtain [solvent-free slurry 1].

[0271] (Agglutination process) To [Desolvated Slurry 1], 30 parts by mass of a 5% calcium chloride solution was added dropwise as a flocculating salt, and the mixture was 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 terminate the flocculation process, thereby obtaining [Flocculated Slurry 1].

[0272] Only in Example 7 was the following shelling step applied. (Shelling process) 80 parts by mass of [Polyester Resin Emulsion SR for Shell] (solid content concentration 25% by mass) was added to [Aggregated Slurry 1] and stirred. While stirring, a 20% by mass aqueous solution of magnesium sulfate was slowly added dropwise at a rate of 1 part by mass / minute until the particles in the system ceased to undergo Brownian motion as observed under an optical microscope. (fusion process) [Agglomerated Slurry 1] was heated at 70°C for 3 hours while stirring to obtain [Dispersed Slurry 1].

[0273] (Washing and drying process) 100 parts of [Dispersion Slurry 1] was filtered under reduced pressure, and then the following operations (1) to (4) were carried out three times to obtain [Filter Cake 1]. (1) 100 parts of ion-exchanged water was added to the filter cake, and the mixture was mixed with a TK homomixer (at 12,000 rpm for 10 minutes) and then filtered. (2): 100 parts of a 10% aqueous sodium hydroxide solution was added to the filter cake of (1), and the mixture was mixed in a TK homomixer (at 12,000 rpm for 30 minutes), followed by filtration under reduced pressure. (3): 150 parts of 10% hydrochloric acid was added to the filter cake of (2), and the mixture was mixed in a TK homomixer (at 12,000 rpm for 20 minutes) and then filtered. (4): 300 parts of ion-exchanged water was added to the filter cake of (3), and the mixture was mixed in a TK homomixer (at 12,000 rpm for 10 minutes) and then filtered.

[0274] The obtained [filter cake 1] was dried in a circulating air dryer at 45° C. for 48 hours and sieved through a mesh with 75 μm openings to obtain [resin particle base particles 1].

[0275] (External additive processing process) 100 parts by mass of [resin particle mother particles 1] were mixed with fine particles A and fine particles B as external additives as shown in Table 1 in a Henschel mixer, and the mixture was passed through a 500 mesh sieve to obtain [resin particles 1]. Note that microparticles A are silica microparticles (manufactured by Fuso Chemical Co., Ltd.) with an average particle diameter of approximately 160 nm that have been hydrophobized with HMDS, and microparticles B are silica microparticles (manufactured by Nippon Aerosil Co., Ltd.) with an average particle diameter of approximately 30 nm that have been hydrophobized with HMDS.

[0276] [Examples 2 to 7 and Comparative Examples 1 to 6] Resin particles of Examples 2 to 7 and Comparative Examples 1 to 6 were produced in the same manner as in Example 1, except that the heating temperature, amount of PET added, time, and type and amount of external additive in the fusion step were changed as shown in Table 1. The properties of the obtained resin particles are shown in Table 2. In Table 2, the unit of BET specific surface area is m 2 / g, and the content ratio of fine particles A / fine particles B is a mass ratio.

[0277] [Table 1]

[0278] [Table 2]

[0279] <Evaluation of characteristics> The resin particles of each of the above examples and comparative examples were used as toner, and the toner properties, such as environmental friendliness, low-temperature fixability, image quality, and charging property, were evaluated. The evaluation results are shown in Table 3.

[0280] [Environmental friendliness] The environmental friendliness was evaluated based on the ratio of the environmentally friendly resin in the toner, according to the following evaluation criteria. (Evaluation criteria) A: Recycled resin is 50% or more B: Recycled resin is 30% or more but less than 50% C: Less than 30% recycled resin A and B ratings are considered to be sufficient environmental compatibility.

[0281] [Image Quality] Image quality was evaluated by observing the reproducibility of fine lines. The resin particles were placed in an imageo MP C5503 (manufactured by Ricoh Co., Ltd.), and a printing test of 6-point and 10-point characters was performed under an environment with a temperature of 30°C and a relative humidity of 80%. The reproducibility of the printed characters was evaluated on a three-point scale based on the following evaluation criteria. (Evaluation criteria) A: 6-point characters are clear B: Some of the 6-point text is crushed C: 10-point text is partially crushed A rating and B rating can be considered to have sufficient image quality.

[0282] <Heat-resistant storage stability> The toner was filled into a 50 mL glass container and left in a thermostatic chamber at 50° C. for 24 hours, and then cooled to 24° C. Next, the penetration [mm] was measured by a penetration test (JISK2235-1991) to evaluate the heat resistance storage stability. [Evaluation criteria] ◎:Penetration 20mm or more ○: Penetration 15mm or more and less than 20mm △: Penetration 10mm or more and less than 15mm ×: Penetration less than 10 mm The evaluations of ⊚ and ◯ indicate that the product has sufficient heat-resistant storage stability.

[0283] [Chargeability] The carrier used in the imageo MP C5503 (manufactured by Ricoh Co., Ltd.) was mixed with the resin particles obtained above so that the resin particle concentration was 7% by mass to obtain a developer. The developer was set in the imageo MP C5503 (manufactured by Ricoh Co., Ltd.), and a running evaluation of 300,000 sheets was performed in monochrome mode using an image chart with a 50% image area. The charge change of the carrier after this running was then determined based on the following evaluation criteria to evaluate the chargeability. The charge change is as follows: That is, a sample was conditioned in an open system for 30 minutes or more in an environment of 23°C temperature and 50% relative humidity (M / M environment), and then 6,000 g of initial carrier and 0.452 g of toner were added to a stainless steel container, which was then sealed. The container was then run for 5 minutes at 150 using a YS-LD (a shaker manufactured by Yayoi Co., Ltd.) and subjected to approximately 1,100 shaking cycles to triboelectrically charge the sample. The charge amount measured using a standard blow-off method (TB-200 manufactured by Toshiba Chemical Co., Ltd.) for this sample was Q1, and the toner in the developer after running was removed using the blow-off device, resulting in a carrier obtained, was measured using the same method, and the resulting charge amount was Q2. (Evaluation criteria) A: The change in charge amount is less than 10 μc / g B: Charge amount change is 10 μc / g or more and less than 20 μc / g C: Charge change is 20 μc / g or more A rating and B rating can be judged to have sufficient charging properties.

[0284] [Table 3]

[0285] From Table 3, it was confirmed that the resin particles of Examples 1 to 7 were toners that satisfied the requirements for use in terms of environmental compatibility, heat-resistant storage stability, image quality, and chargeability. In contrast, it was confirmed that the resin particles obtained in Comparative Examples 1 to 6 did not satisfy the requirements for use in terms of at least one of environmental compatibility, heat-resistant storage stability, image quality, and chargeability, and were toners that had practical problems.

[0286] Although the embodiments have been described above, they are presented as examples and the present invention is not limited to the above embodiments. The above embodiments can be implemented in various other forms, and various combinations, omissions, substitutions, modifications, etc. can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the inventions and their equivalents as set forth in the claims.

[0287] The embodiment of the present invention is as follows, for example. <1> Resin particles containing mother particles containing polyethylene terephthalate or polybutylene terephthalate and an external additive, The BET specific surface area of ​​the base particles is 0.8 to 1.4 m 2 / g, The external additive contains at least two types of particles: fine particles A having an average particle diameter of 100 nm or more and fine particles B having an average particle diameter of 10 to 50 nm, and the content ratio (mass ratio) A / B of the fine particles A to B is 0.5 to 1.4. <2> The base particles further contain an amorphous resin, a crystalline resin, and a release agent. <1> The resin particles according to claim 1. <3> The content of polyethylene terephthalate or polybutylene terephthalate relative to the total mass of the resin particles is 30% by mass or more. <1> or <2> The resin particles according to claim 1. <4> The base particles have a core-shell structure, and the shell portion contains polyethylene terephthalate or polybutylene terephthalate. <1> ~ <3> The resin particles according to any one of the preceding items. <5> <1> ~ <4> A method for producing the resin particles according to any one of the above, A manufacturing method including the steps of: preparing a solution by dissolving or dispersing a resin containing at least polyethylene terephthalate or polybutylene terephthalate in an organic solvent; adding water to the solution to invert the phase from a water-in-oil dispersion to an oil-in-water dispersion; aggregating fine particles in the oil-in-water dispersion; and attaching an external additive to the base particles. <6> <1> ~ <4> 2. A toner containing the resin particles according to any one of claims 1 to 11. <7> <6> A toner storage container containing the toner described in claim 1. <8> 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 with toner to form a toner image, wherein the toner is <6> 10. An image forming apparatus, comprising the toner according to claim 9. [Explanation of symbols]

[0288] 10 Photosensitive drum 40 Developer 58 Corona charger 80 Transfer roller 90 Cleaning Device 95 Recording Paper 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) 210 Paper feed section 211 Paper cassette 212 Paper feed roller 220 Conveyor 221 Laura 222 Timing roller 223 Paper ejection 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 device 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 Cleaner (cyan) 236M Cleaner (Magenta) 236K Cleaning Tool (Black) 240 Transcription Unit 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 Fixing unit 251 Fixing belt 252 pressure roller L Laser P paper [Prior art documents] [Patent documents]

[0289] [Patent Document 1] Patent No. 6138021

Claims

1. Resin particles containing mother particles containing polyethylene terephthalate or polybutylene terephthalate and an external additive, The BET specific surface area of ​​the base particles is 0.8 to 1.4 m ２ / g, The external additive contains at least two types of particles: fine particles A having an average particle diameter of 100 nm or more and fine particles B having an average particle diameter of 10 to 50 nm; and the content ratio (mass ratio) A / B of the fine particles A to B is 0.5 to 1.

4.

2. 2. The resin particles according to claim 1, wherein the base particles further contain an amorphous resin, a crystalline resin, and a release agent.

3. 2. The resin particles according to claim 1, wherein the content of polyethylene terephthalate or polybutylene terephthalate relative to the total mass of the resin particles is 30% by mass or more.

4. 2. The resin particle according to claim 1, wherein the base particle has a core-shell structure, and the shell portion contains polyethylene terephthalate or polybutylene terephthalate.

5. A method for producing the resin particles according to claim 1, comprising: A manufacturing method including the steps of: preparing a solution by dissolving or dispersing a resin containing at least polyethylene terephthalate or polybutylene terephthalate in an organic solvent; adding water to the solution to invert the phase from a water-in-oil dispersion to an oil-in-water dispersion; aggregating fine particles in the oil-in-water dispersion; and attaching an external additive to the base particles.

6. A toner containing the resin particles according to claim 1.

7. A toner storage container containing the toner according to claim 6.

8. 7. An image forming apparatus comprising: 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 with toner to form a toner image, wherein the toner is the toner according to claim 6.

Images