Toner

Abstract

The present invention relates to a toner having toner particles including a binder resin, in which the toner particles include a compound A having a specific polyether structure and an ester wax, the binder resin includes a polyester resin having a monomer unit corresponding to dodecenylsuccinic acid, and an SP value (cal / cm3) 0.5 of the ester wax is from 8.70 to 9.00.

Description

Technical Field

[0001] The present disclosure relates to a toner for developing an electrostatic image in an image forming apparatus such as an electrophotographic and an electrostatic printing apparatus. Background Art

[0002] Laser printers and copiers are representative electrophotographic apparatuses that use toner. In recent years, in addition to stable image quality, there has been a demand for high productivity, particularly for laser printers. As a means for improving productivity, by simultaneously achieving excellent charge elevation performance and low-temperature fixability, the speed until the initial print output is improved, and by maintaining the built-up charge, stable image quality can be provided.

[0003] Methods for improving low-temperature fixability include designing a toner binder resin having a low glass transition temperature (Tg), reducing the molecular weight of the toner binder resin to lower the melt viscosity, and using the plasticizing action of a crystalline material compatible with the toner binder resin. However, these methods have the problem that the image quality changes significantly due to relaxation phenomena occurring in the toner binder resin itself or in a material compatible with the toner binder resin.

[0004] In Japanese Patent Application Laid-Open No. 2021-001975, the acid value / hydroxyl value of an ester composition is adjusted to increase the affinity with the toner binder resin, thereby improving low-temperature fixability, heat stain resistance, and durability. In addition, a method is proposed in which the ester composition crystallizes at room temperature, thereby improving storage stability.

[0005] In Japanese Patent Application Laid-Open No. 2020-109500, the SP value of a silicone polymer, the domain diameter and SP value of an ester wax, and the SP value of a binder resin are controlled to increase their compatibility, thereby improving low-temperature fixability. In addition, the durability is improved by controlling the crosslink density of the silicone polymer.

[0006] In Japanese Patent Application Laid-Open No. 2018-081259, the melting point of a crystalline polyester resin is controlled by a resin composition to improve low-temperature fixability, and by controlling the content, resin composition, and molecular weight of a block polymer, the meltability of the toner can be controlled. This reduces density unevenness and gloss unevenness of the image and improves the image quality.

[0007] In addition, in Japanese Patent Application Laid-Open No. 2020-154224, toner base particles include a nonionic surfactant to improve the dispersibility of each material constituting the toner, and the toner includes tin oxide particles as an external additive to control the charging property. As a result, excellent color streak suppression is achieved even when continuous printing is performed after allowing the toner to stand in a high-temperature and high-humidity environment. SUMMARY OF THE INVENTION

[0008] However, the above-mentioned literature has problems in achieving even higher speeds and stable image quality.

[0009] In Japanese Patent Application Laid-Open No. 2021-001975, it is necessary to adjust the acid value / hydroxyl value of the ester wax and improve the affinity with the toner binder resin to improve low-temperature fixability, heat stain resistance, and durability. However, increasing the affinity between the ester wax and the toner binder resin causes problems such as a decrease in charge elevation performance and a change in image quality between the initial image and the image after continuous printing.

[0010] In Japanese Patent Application Laid-Open No. 2020-109500, it is necessary to control the resin composition of the binder resin and improve the affinity between the toner binder resin and the ester wax to improve low-temperature fixability. However, as in Japanese Patent Application Laid-Open No. 2021-001975, increasing the affinity between the ester wax and the toner binder resin causes problems such as a decrease in charge elevation performance and a change in image quality between the initial image and the image after continuous printing.

[0011] In Japanese Patent Application Laid-Open No. 2018-081259, one means to improve low-temperature fixability is to increase the amount of wax added. However, although increasing the amount of wax added improves low-temperature fixability, it also improves the compatibility with the toner binder resin, and as in Japanese Patent Application Laid-Open No. 2021-001975 and Japanese Patent Application Laid-Open No. 2020-109500, the charging property is significantly reduced, and image stability and image density uniformity are reduced.

[0012] In addition, in Japanese Patent Application Laid-Open No. 2020-154224, a nonionic surfactant is included in the toner, and tin oxide particles are added as an external additive, whereby even when continuous printing is performed after allowing the toner to stand in a high-temperature and high-humidity environment, the charging property can be controlled and excellent color streak suppression can be ensured. However, in the case of the toner structure described in Japanese Patent Application Laid-Open No. 2020-154224, the compatibility between the wax and the binder resin is low, and low-temperature fixability may be insufficient.

[0013] Therefore, the present disclosure provides a toner having excellent low-temperature fixability and excellent charging properties, such as image stability and image density uniformity during continuous printing.

[0014] The present disclosure relates to a toner comprising toner particles containing a binder resin, wherein,

[0015] the toner particles contain an ester wax and Compound A, and Compound A is at least one compound selected from the group consisting of the compounds represented by the following formula (1) and the compounds represented by the following formula (2),

[0016] the binder resin contains a polyester resin,

[0017] the polyester resin contains monomer units corresponding to dodecenyl succinic acid, and

[0018] the SP value (cal / cm 3 ) 0.5 of the ester wax is 8.70 to 9.00.

[0019] R 1 -O-(A 1 -O) n -X(1)

[0020] In formula (1), R 1 represents an alkyl group having 8 to 24 carbon atoms, A 1 represents ethylene or propylene, n is an integer of 5 to 60, and X is H, CH2COOH, CH2SO3H, CH2COONa or CH2SO3Na.

[0021] R 2 -Ph-O-(A 2 -O) m -X(2)

[0022] In formula (2), R 2 represents an alkyl group having 8 to 24 carbon atoms, Ph represents phenylene, A 2 represents ethylene or propylene, m is an integer of 5 to 60, and X is H, CH2COOH, CH2SO3H, CH2COONa or CH2SO3Na.

[0023] According to the present disclosure, a toner having excellent low-temperature fixability and excellent charging properties such as image stability and image density uniformity during continuous printing can be provided.

[0024] Other features of the present invention will become apparent from the following description of the exemplary embodiments. Detailed Description

[0025] In the present disclosure, unless otherwise specified, "XX to YY" or "XX~YY" indicating a numerical range means a numerical range including the lower limit and the upper limit as endpoints. In the case of describing numerical ranges in stages, the upper and lower limits of each numerical range can be combined as needed.

[0026] In addition, in the present disclosure, for example, a description such as "at least one selected from the group consisting of XX, YY, and ZZ" means any one of XX, YY, ZZ, a combination of XX and YY, a combination of XX and ZZ, a combination of YY and ZZ, or a combination of XX, YY, and ZZ.

[0027] In order to obtain a toner having excellent low-temperature fixability and charging properties and also excellent image stability and image density uniformity during continuous printing, the inventors have conducted extensive research on the charging performance of wax and its compatibility with polyester resin. The inventors have found that by introducing monomer units corresponding to specific acids into the polyester resin, controlling the SP value of ester wax, and further introducing a compound having a polyether structure into the toner, the above problems can be solved.

[0028] That is, the present disclosure relates to a toner comprising toner particles containing a binder resin, wherein

[0029] the toner particles contain ester wax and Compound A, and Compound A is at least one compound selected from the group consisting of the compound represented by the following formula (1) and the compound represented by the following formula (2),

[0030] the binder resin contains a polyester resin,

[0031] the polyester resin contains monomer units corresponding to dodecenyl succinic acid, and

[0032] the SP value (cal / cm 3 ) 0.5 of the ester wax is 8.70 to 9.00.

[0033] R 1 -O-(A 1 -O) n -X(1)

[0034] (In formula (1), R 1 represents an alkyl group having 8 to 24 carbon atoms, A 1 represents ethylene or propylene, n is an integer of 5 to 60, and X is H, CH2COOH, CH2SO3H, CH2COONa, or CH2SO3Na),

[0035] R 2 -Ph-O-(A 2 -O) m -X(2)

[0036] (In Formula (2), R 2 represents an alkyl group having 8 to 24 carbon atoms, Ph represents a phenylene group, A 2 represents an ethylene group or a propylene group, m is an integer of 5 to 60, and X is H, CH2COOH, CH2SO3H, CH2COONa, or CH2SO3Na).

[0037] The toner of the present disclosure includes a polyester resin containing monomer units corresponding to dodecenyl succinic acid as a binder resin. The polyester resin improves the compatibility with wax. The monomer units corresponding to dodecenyl succinic acid are derived from an alkyl chain and are low-polarity units in structure, having the effect of improving the compatibility with low-polarity materials such as ester wax. In particular, the alkyl chain of dodecenyl succinic acid can exhibit higher compatibility by existing as a side chain of the polyester molecule. In addition, by controlling the SP value (cal / cm 3 ) 0.5 of the ester wax to 8.70 to 9.00, the charging performance is improved.

[0038] The monomer units corresponding to dodecenyl succinic acid in the polyester resin have a structure in which dodecenyl succinic acid forms an ester bond, and are represented, for example, by the following formula (D).

[0039]

[0040] However, when only the above design is used, overcharging occurs during continuous printing, resulting in low concentration at the front end and reduced uniformity of image concentration. Therefore, an attempt is made to improve the charging stability by introducing a compound having a polyether structure into the toner particles. As a result, it has been found that by introducing Compound A, which is at least one compound selected from the group consisting of the compounds represented by the following formula (1) and the compounds represented by the following formula (2), into the toner particles, in addition to excellent low-temperature fixability, stable charging performance can be obtained even when continuous printing is repeated.

[0041] The inventors speculate that this effect is demonstrated by the following mechanism. The monomer units corresponding to dodecenyl succinic acid have a highly polar succinic acid part and a low-polar long-chain alkyl part. Therefore, the ester wax, which is a low-polarity material, easily approaches the monomer units corresponding to dodecenyl succinic acid and exhibits a strong interaction between the highly polar group part of dodecenyl succinic acid and the ester group part of the ester wax. This interaction generates a part with higher polarity. It is considered that this highly polar part easily stores charges and contributes to charge retention.

[0042] The polyether structure of Compound A also has the function of improving the charge mobility within the toner particles, and due to the high affinity of the structure of Compound A with the polyester resin, the interaction with the polyether segment is well exhibited. It is speculated that the above mechanism results in excellent charge elevation performance and charging stability during repeated continuous printing.

[0043] Therefore, the SP value (cal / cm 3 ) 0.5 of the ester wax needs to be 8.70 to 9.00. When the SP value of the ester wax is less than 8.70, the interaction with the polyester resin will be weak, damaging the charging performance after continuous printing. At the same time, when the SP value of the ester wax is higher than 9.00, the compatibility with the polyester resin will be low, and the fixing property will decrease. Therefore, the SP value of the ester wax needs to be 8.70 to 9.00, and preferably 8.80 to 8.90.

[0044] In addition, when the toner particles contain Compound A which is at least one compound selected from the group consisting of the compound represented by formula (1) and the compound represented by formula (2), excellent charging stability during continuous printing is achieved. This is due to the improvement of the charge mobility within the toner particles, which is derived from the polyether structure of Compound A. In the case of the structures of formula (1) and (2), the affinity with the polyester resin is high, and the interaction with the polyether segment is well exhibited.

[0045] R 1 -O-(A 1 -O) n -X(1)

[0046] R 2 -Ph-O-(A 2 -O) m -X(2)

[0047] From the viewpoint of the affinity with the polyester resin, in formula (1), R 1 is preferably an alkyl group having 8 to 24 carbon atoms, more preferably an alkyl group having 10 to 18 carbon atoms. In addition, in formula (2), R 2 is preferably an alkyl group having 8 to 24 carbon atoms, more preferably an alkyl group having 9 to 12 carbon atoms. Furthermore, in order to obtain excellent charge mobility within the toner particles, in formula (1), n is preferably 5 to 60, more preferably 6 to 30, and even more preferably 8 to 20. In order to obtain excellent charge mobility, in formula (2), m is preferably 5 to 60, more preferably 6 to 30, and even more preferably 8 to 20.

[0048] When R 1 and R 2When the number of carbon atoms in [alkyl group] is less than the lower limit, the intermolecular interaction between alkyl groups decreases, and Compound A is less likely to approach dodecenyl succinic acid or ester wax, making it difficult to maintain the charge inside the toner and reducing the charging stability on the toner surface. This is considered to result in a decrease in concentration uniformity after continuous printing. In addition, when the number of carbon atoms in R 1 and R 2 exceeds the upper limit, the molecular weight of Compound A becomes too large, making it difficult to move inside the toner, thereby reducing the charge transportability inside the toner and the charge elevation performance, which is considered to result in a decrease in concentration stability after continuous printing.

[0049] When n and m are less than the lower limit, the affinity between the polyester resin and Compound A decreases, making it difficult to maintain the charge inside the toner and reducing the charging stability on the toner surface. This is considered to result in a decrease in concentration uniformity after continuous printing. In addition, when n and m exceed the upper limit, the molecular weight of Compound A becomes too large, making it difficult to move inside the toner, thereby reducing the charge transportability inside the toner and the charge elevation performance, which is considered to result in a decrease in concentration stability after continuous printing.

[0050] In Formula (1) or Formula (2), A 1 or A 2 represents ethylene (-CH2CH2-) or propylene (-CH(CH3)CH2-), preferably ethylene. In Formula (1) or Formula (2), X represents H, CH2COOH, CH2SO3H, CH2COONa, or CH2SO3Na, preferably H, but may also be CH2COOH or CH2SO3H.

[0051] Next, the SP value (cal / cm 3 ) 0.5 of the ester wax is 8.70 to 9.00. The molecular weight of the ester wax is, for example, 500 to 2000, preferably 500 to 1000, more preferably 500 to 800. This is because the ester wax satisfying the above conditions has excellent compatibility with the polyester resin and a high crystallization rate from the compatible state. As the ester wax satisfying the above conditions, an ester wax (diester wax) having two (bifunctional) or more ester structures in the molecule is preferably used.

[0052] In the present disclosure, the molecular weight of the ester wax is a value calculated from the structure of the ester wax. In addition, in the case of an ester wax having a molecular weight distribution such as an ester wax derived from a natural product or a synthetic wax using a monomer or polymer derived from a natural product as a monomer component, the peak molecular weight of the molecular weight distribution obtained by GPC analysis is used as the molecular weight of the ester wax.

[0053] Examples of the ester waxes include ethylene glycol distearate, ethylene glycol behenate, ethylene glycol dipalmitate, 1,4-butanediol distearate, 1,4-butanediol behenate, 1,4-butanediol dipalmitate, 1,6-hexanediol distearate, 1,6-hexanediol behenate, 1,6-hexanediol dipalmitate, 1,8-octanediol distearate, 1,8-octanediol behenate, 1,8-octanediol dipalmitate, 1,10-decanediol distearate, 1,10-decanediol behenate, 1,10-decanediol dipalmitate, succinic acid distearyl ester, succinic acid dipalmitic ester, succinic acid behenyl ester, adipic acid distearyl ester, adipic acid dipalmitic ester, adipic acid behenyl ester, suberic acid distearyl ester, suberic acid dipalmitic ester, suberic acid behenyl ester, dodecanoic acid distearyl ester, dodecanoic acid dipalmitic ester, and dodecanoic acid behenyl ester, etc.

[0054] Among them, preferably, the ester wax contains a diester wax which is a compound represented by the following formula (3).

[0055] R 3 -COO-R 5 -OCO-R 4 (3)

[0056] (R 3 and R 4 each independently represents an alkyl group having 17 to 22 carbon atoms, and R 5 represents an alkylene group having 2 to 6 carbon atoms.)

[0057] The ester wax having the structure of formula (3) has excellent crystallinity because the alkyl chains represented by R 3 and R 4 are long enough, and the proportion of the ester groups included is sufficient for compatibility with the polyester resin. In addition, since the alkylene chain represented by R 5 is short, the interaction between the highly polar group part corresponding to the dodecenyl succinic acid monomer unit and the ester group part of the wax is more strongly manifested. In formula (3), R 3 and R 4 each independently represents an alkyl group having 17 to 22 carbon atoms, more preferably 17 to 19 carbon atoms, and R 5 is preferably an alkylene group having 2 to 6 carbon atoms, more preferably 2 to 4 carbon atoms.

[0058] The melting point of the ester wax is preferably 60°C to 90°C.

[0059] In addition, the content of the ester wax in the toner particles is, for example, 2.5 parts by mass to 25.0 parts by mass, preferably 3.0 parts by mass to 20.0 parts by mass, and more preferably 10.0 parts by mass to 15.0 parts by mass with respect to 100 parts by mass of the binder resin. Within the above range, the compatibility between the ester wax and the polyester resin is better, and the low-temperature fixability is better. In addition, within the above range, it is easy to separate from the state compatible with the polyester resin and promote crystallization.

[0060] In addition, the binder resin may contain a resin other than the polyester resin. In this case, the content ratio of the polyester resin is preferably 50.0 mass% to 100.0 mass%, more preferably 60.0 mass% to 100.0 mass%, even more preferably 70.0 mass% to 100.0 mass%, and still more preferably 85.0 mass% to 100.0 mass% based on the mass of the binder resin. Within the above range, it is easy to obtain better low-temperature fixability and charging performance.

[0061] The content ratio of the monomer unit corresponding to dodecenyl succinic acid based on the mass of the binder resin is, for example, 2.5 mass% to 22.0 mass%, preferably 3.0 mass% to 20.0 mass%, and more preferably 5.0 mass% to 14.0 mass%. Within the above range, the charging performance is likely to be more stable.

[0062] The content ratio of the monomer unit corresponding to dodecenyl succinic acid in the binder resin can be controlled by adjusting the amount of dodecenyl succinic acid during the production of the binder resin.

[0063] The extraction amount of compound A extracted from the toner with ethanol is, for example, 10 ppm to 1200 ppm, preferably 10 ppm to 1000 ppm based on the mass of the toner. In the toner, charges are generated by triboelectric charging on the surface of the toner particles. When the extraction amount of compound A is within the above range, the generated charges become uniform on the surface of the toner particles, and the excessive charges can be effectively released. The extraction amount is more preferably 30 ppm to 500 ppm, and even more preferably 50 ppm to 300 ppm.

[0064] The extraction amount of compound A is adjusted according to the addition amount of compound A during the toner production step. The timing of adding compound A can be during the toner particle production step, or it can be after the toner particle production. From the viewpoint of improving the interaction with the polyester resin, it is preferable to add compound A during the toner particle production step, and from the viewpoint of ensuring uniform presence on the surface of the toner particles, it is preferable to add compound A in an aqueous medium.

[0065] In addition, in the cross-sectional observation of the toner using a transmission electron microscope, the average ratio of the area occupied by the domains of wax (including ester wax) in the surface layer region from the surface of the toner particle to a depth of 200 nm is defined as As. In this case, As is from 0.0 area% to 2.0 area%, preferably from 0.0 area% to 1.0 area%. Here, As within the above range indicates that there is almost no wax near the surface of the toner particle.

[0066] In the present disclosure, by promoting the crystallization of the ester wax to stabilize the state of the wax after continuous printing, changes in the charging performance are suppressed, but it is difficult to completely crystallize the ester wax. In particular, since the compatible components of the ester wax may remain around the wax domains, by setting As within the above range, the migration of the compatible components to the surface of the toner particle can be further suppressed. As is more preferably from 0.0 area% to 0.5 area%.

[0067] When the toner particle is formed to have a core-shell structure, it can be adjusted by controlling the addition amount of the wax and the thickness of the shell layer.

[0068] Preferably, the toner particle contains a boron atom. When the content of the boron atom is, for example, from 1.0 ppm to 55.0 ppm, preferably from 1.0 ppm to 50.0 ppm based on the mass of the toner particle, it is easy to obtain toner particles having excellent charge elevation performance and excellent charging stability. The ionization potential of the boron atom is large and it easily forms covalent bonds, so it is considered to interact with a large number of ester groups in the polyester resin. It is considered that, as a result, the boron atom is easily dispersed in the polyester resin containing the boron atom, thereby improving the charge retention of the toner. In addition, it is considered that the interaction between the boron atom and a large number of ester groups of the polyester resin forms a pseudo-bridging state via the boron atom, which suppresses the movement of the incompletely crystallized ester wax and enables the obtaining of a toner having excellent charging stability.

[0069] The content of the boron atom is more preferably from 3.0 ppm to 30.0 ppm, and even more preferably from 3.0 ppm to 15.0 ppm. The boron atom can be introduced into the toner particle by adding a compound containing the boron atom during the toner particle production step, and the content can be adjusted by the addition amount of the compound containing the boron atom.

[0070] [Constituent Components of the Toner]

[0071] The components constituting the toner and the production method of the toner will be explained in more detail below.

[0072] [Binder Resin]

[0073] The toner particles include a binder resin. The binder resin includes a polyester resin. As described above, the binder resin may contain resins other than the polyester resin. Preferably, the binder resin contains a polyester resin in an amount of 50% by mass or more. Examples of the binder resin other than the polyester resin are as follows.

[0074] There is no particular limitation on the binder resin, but examples thereof include styrene-acrylic resins, epoxy resins, polyurethane resins, polyamide resins, cellulose resins, polyether resins, and their mixed resins and composite resins. Styrene-acrylic resins and polyester resins are preferred because they are inexpensive, easily available, and have excellent low-temperature fixability.

[0075] The polyester resin is obtained by selecting appropriate ones from polycarboxylic acids, polyols, hydroxycarboxylic acids, etc. and combining them, and synthesizing them using a conventionally known method such as a transesterification method or a polycondensation method.

[0076] A polycarboxylic acid is a compound containing two or more carboxyl groups in one molecule. Among them, a dicarboxylic acid is a compound containing two carboxyl groups in one molecule, and a dicarboxylic acid is preferably used.

[0077] The polyester resin preferably contains 3.0% by mass to 20.0% by mass of monomer units corresponding to dodecenyl succinic acid as a polycarboxylic acid. The content of the monomer units corresponding to dodecenyl succinic acid is preferably 5 mol% to 40 mol%, more preferably 10 mol% to 25 mol% in the 100 mol% polycarboxylic acid component of the polyester resin. Examples of polycarboxylic acids other than dodecenyl succinic acid in the polyester resin are as follows.

[0078] Examples of dicarboxylic acids include oxalic acid, succinic acid, glutaric acid, maleic acid, adipic acid, β-methyladipic acid, azelaic acid, sebacic acid, nonanedicarboxylic acid, decanedicarboxylic acid, undecanedicarboxylic acid, dodecanedicarboxylic acid, fumaric acid, citraconic acid, diglycolic acid, cyclohexane-3,5-diene-1,2-dicarboxylic acid, hexahydroterephthalic acid, malonic acid, pimelic acid, suberic acid, phthalic acid, terephthalic acid, isophthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-carboxyphenylacetic acid, p-phenylenediacetic acid, m-phenylenediacetic acid, o-phenylenediacetic acid, diphenylacetic acid, diphenyl-p,p′-dicarboxylic acid, naphthalene-1,4-dicarboxylic acid, naphthalene-1,5-dicarboxylic acid, naphthalene-2,6-dicarboxylic acid, anthracenedicarboxylic acid, and cyclohexanedicarboxylic acid, etc.

[0079] Examples of polycarboxylic acids other than dicarboxylic acids include trimellitic acid, pyromellitic acid, mellitic acid, naphthalenetricarboxylic acid, naphthalenetetracarboxylic acid, pyrenetricarboxylic acid, pyrenetetracarboxylic acid, itaconic acid, and pentenedioic acid, etc. These may be used alone or in combination of two or more.

[0080] A polyol is a compound containing two or more hydroxyl groups in one molecule. Among them, a diol is a compound containing two hydroxyl groups in one molecule, and a diol is preferably used.

[0081] Specific examples include ethylene glycol, diethylene glycol, triethylene glycol, 1,2 - propanediol, 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 - eicosanediol, diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene ether glycol, 1,4 - cyclohexanediol, 1,4 - cyclohexanedimethanol, 1,4 - butenediol, neopentyl glycol, 1,4 - cyclohexanediol, polytetramethylene glycol, hydrogenated bisphenol A, bisphenol A, bisphenol F, bisphenol S, and alkylene oxide (ethylene oxide, propylene oxide, and butylene oxide, etc.) adducts of the above bisphenols, etc.

[0082] Among them, an alkylene glycol having 2 to 12 carbon atoms and an alkylene oxide adduct of bisphenol are preferred, and an alkylene oxide adduct of bisphenol and a combination thereof with an alkylene glycol having 2 to 12 carbon atoms are particularly preferred.

[0083] Examples of polyols having three or more hydroxyl groups include glycerol, trimethylolethane, trimethylolpropane, pentaerythritol, hexamethylolmelamine, hexahydroxyethylmelamine, tetramethylolbenzoguanamine, tetrahydroxyethylbenzoguanamine, sorbitol, Trisphenol PA, phenol novolac, cresol novolac, and alkylene oxide adducts of the above polyphenols having three or more hydroxyl groups. These can be used alone or in combination of two or more.

[0084] More preferably, in addition to dodecenyl succinic acid, the polycarboxylic acid further includes at least one selected from the group consisting of terephthalic acid, isophthalic acid, sebacic acid, and trimellitic acid.

[0085] More preferably, the polyol includes at least one selected from the group consisting of an alkylene oxide (ethylene oxide, propylene oxide) adduct of bisphenol A (for example, 1 to 10 moles, preferably 1 to 5 moles) and an alkylene glycol having 2 to 6 carbon atoms.

[0086] The weight - average molecular weight Mw of the polyester resin is preferably from 10,000 to 100,000, more preferably from 20,000 to 50,000.

[0087] The acid value of the polyester resin is preferably from 10.0 mgKOH / g to 40.0 mgKOH / g, more preferably from 15.0 mgKOH / g to 25.0 mgKOH / g. The hydroxyl value of the polyester resin is preferably from 20.0 mgKOH / g to 50.0 mgKOH / g, more preferably from 25.0 mgKOH / g to 35.0 mgKOH / g.

[0088] The styrene acrylic resin may be a homopolymer made from the following polymerizable monomers, a copolymer obtained by combining two or more of these monomers, or a mixture thereof.

[0089] Styrene monomers such as styrene, α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, p-n-butylstyrene, p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-decylstyrene, p-n-dodecylstyrene, p-methoxystyrene, and p-phenylstyrene;

[0090] (Meth)acrylic monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, n-pentyl (meth)acrylate, n-hexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, n-nonyl (meth)acrylate, cyclohexyl (meth)acrylate, benzyl (meth)acrylate, dimethyl phosphate ethyl (meth)acrylate, diethyl phosphate ethyl (meth)acrylate, dibutyl phosphate ethyl (meth)acrylate, 2-benzoyloxyethyl (meth)acrylate, (meth)acrylonitrile, 2-hydroxyethyl (meth)acrylate, (meth)acrylic acid, and maleic acid;

[0091] Vinyl ether monomers such as vinyl methyl ether and vinyl isobutyl ether;

[0092] Vinyl ketone monomers such as vinyl methyl ketone, vinyl ethyl ketone, and vinyl isopropenyl ketone; and

[0093] Polyolefins such as ethylene, propylene, and butadiene.

[0094] The polyfunctional polymerizable monomers can be used for styrene acrylic resins as needed. Examples of the polyfunctional polymerizable monomers include diethylene glycol di(meth)acrylate, triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polyethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 2,2'-bis(4-((meth)acryloyloxy diethoxy)phenyl)propane, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, divinylbenzene, divinylnaphthalene, and divinyl ether, etc.

[0095] In order to control the degree of polymerization, known chain transfer agents and polymerization inhibitors can be further added.

[0096] The polymerization initiators used to obtain styrene acrylic resins include organic peroxide initiators and azo polymerization initiators.

[0097] Examples of the organic peroxide initiators include benzoyl peroxide, lauroyl peroxide, di-α-cumyl peroxide, 2,5-dimethyl-2,5-bis(benzoyl peroxide)hexane, bis(4-tert-butylcyclohexyl) peroxydicarbonate, 1,1-bis(tert-butylperoxy)cyclododecane, tert-butyl maleic peroxide, bis(tert-butylperoxy) isophthalate, methyl ethyl ketone peroxide, tert-butyl-2-ethylhexanoate peroxide, diisopropyl peroxydicarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, and tert-butyl neopentanoate peroxide.

[0098] Examples of the azo polymerization initiators include 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis(cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobis(methylbutyronitrile), and 2,2'-azobis-(methyl isobutyrate).

[0099] In addition, a redox initiator that combines an oxidizing substance and a reducing substance can also be used as the polymerization initiator.

[0100] Examples of the oxidizing substances include inorganic peroxides such as hydrogen peroxide and persulfates (sodium salts, potassium salts, and ammonium salts), and metal oxide salts such as cerium(IV) salts.

[0101] Reducing substances include reducing metal salts (ferrous salts, cuprous salts, and chromium(III) salts), ammonia, lower amines (amines having 1 to 6 carbon atoms, such as methylamine and ethylamine), amino compounds such as hydroxylamine, reducing sulfur compounds such as sodium thiosulfate, sodium dithionite, sodium bisulfite, sodium sulfite, and Rongalite, lower alcohols (having 1 to 6 carbon atoms), ascorbic acid or its salts, and lower aldehydes (having 1 to 6 carbon atoms).

[0102] The polymerization initiator is selected with reference to the 10-hour half-life temperature and can be used alone or in combination. The addition amount of the polymerization initiator varies depending on the desired degree of polymerization, but is usually 0.5 to 20.0 parts by mass with respect to 100.0 parts by mass of the polymerizable monomer.

[0103] <wax>

[0104] The toner particles include wax, and the wax includes ester wax. In addition to the ester wax, the toner particles may contain other known waxes within the range that does not impair the effects of the present disclosure. Specific examples of waxes other than the ester wax include hydrocarbon waxes such as paraffin wax, microcrystalline wax, Fischer-Tropsch wax, polyolefins (e.g., polyethylene), petroleum waxes such as petrolatum and its derivatives, and montan wax and its derivatives.

[0105] Preferably, the wax other than the ester wax contains hydrocarbon wax. The content of the other wax is preferably 1.0 to 5.0 parts by mass with respect to 100.0 parts by mass of the binder resin.

[0106] <Compound A>

[0107] Compound A is at least one compound selected from the group consisting of the compound represented by the following formula (1) and the compound represented by the following formula (2).

[0108] R 1 -O-(A 1 -O) n -X(1)

[0109] (In formula (1), R 1 represents an alkyl group having 8 to 24 carbon atoms, A 1 represents ethylene or propylene, n is an integer of 5 to 60, and X is H, CH2COOH, CH2SO3H, CH2COONa, or CH2SO3Na),

[0110] R 2 -Ph-O-(A 2 -O) m -X(2)

[0111] (In formula (2), R 2 represents an alkyl group having 8 to 24 carbon atoms, Ph represents phenylene, A 2represents ethylene or propylene, m is an integer from 5 to 60, and X is H, CH2COOH, CH2SO3H, CH2COONa, or CH2SO3Na).

[0112] There is no particular limitation on the production method of the above compounds, and any method can be used. For example, depending on the purpose, the above compounds can be obtained by adding a predetermined amount of ethylene oxide or propylene oxide to a fatty alcohol. A catalyst can be used for the addition reaction of propylene oxide. As the catalyst, alkali metal hydroxides such as NaOH or KOH, or a catalyst containing magnesium oxide as the main component described in Japanese Patent Application Laid-Open No. H08-323200 can be used. The former can obtain a polyvinyl alkyl ether or polypropylene alkyl ether with a relatively wide addition mole number distribution, and the latter can obtain a compound with a relatively narrow addition mole number distribution.

[0113] As exemplified in the toner production method described below, Compound A can also be used as a surfactant.

[0114] <Colorant>

[0115] The toner particles may contain a colorant. As the colorant, known pigments and dyes can be used. From the viewpoint of excellent weather resistance, pigments are preferably used as the colorant.

[0116] Examples of cyan colorants include copper phthalocyanine compounds and their derivatives, anthraquinone compounds, and basic dye lake compounds, etc.

[0117] Specific examples include the following: C.I. Pigment Blue 1, 7, 15, 15:1, 15:2, 15:3, 15:4, 60, 62, and 66.

[0118] Examples of magenta colorants include condensed azo compounds, diketopyrrolopyrrole compounds, anthraquinone compounds, quinacridone compounds, basic dye lake compounds, naphthol compounds, benzimidazolone compounds, thioindigo compounds, and perylene compounds, etc.

[0119] Specific examples include the following: C.I. Pigment Red 2, 3, 5, 6, 7, 23, 48:2, 48:3, 48:4, 57:1, 81:1, 122, 144, 146, 150, 166, 169, 177, 184, 185, 202, 206, 220, 221, and 254, and C.I. Pigment Violet 19.

[0120] Examples of yellow colorants include condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complexes, methylene compounds, and allylamide compounds, etc.

[0121] Specific examples include the following: C.I. Pigment Yellow 12, 13, 14, 15, 17, 62, 74, 83, 93, 94, 95, 97, 109, 110, 111, 120, 127, 128, 129, 147, 151, 154, 155, 168, 174, 175, 176, 180, 181, 185, 191, and 194.

[0122] The black colorants include those obtained by mixing the above yellow colorants, magenta colorants, and cyan colorants to form black, as well as carbon black.

[0123] These colorants can be used alone, in mixtures, or in the form of solid solutions.

[0124] The colorant is preferably used in an amount of 1.0 to 20.0 parts by mass relative to 100.0 parts by mass of the binder resin.

[0125] <Charge control agents and charge control resins>

[0126] The toner particles may contain a charge control agent or a charge control resin.

[0127] The charge control agent can be any known reagent, and is preferably a reagent having a high triboelectric charging speed and capable of stably maintaining a constant triboelectric charge amount. In addition, when producing toner particles by suspension polymerization, a charge control agent having low polymerization inhibitory properties and substantially free of substances soluble in an aqueous medium is particularly preferably used.

[0128] Examples of materials for controlling the toner to be negatively charged include monoazo metal compounds, acetylacetone metal compounds, aromatic hydroxycarboxylic acids, aromatic dicarboxylic acids, metal compounds of hydroxycarboxylic acids and dicarboxylic acids, aromatic monovalent and polyvalent carboxylic acids and their metal salts, acid anhydrides, and their esters, phenolic derivatives such as bisphenol, urea derivatives, metal-containing salicylic acid compounds, metal-containing naphthoic acid compounds, boron compounds, quaternary ammonium salts, calixarenes, and charge control resins.

[0129] Examples of charge control resins include polymers or copolymers having a sulfonic acid group, a sulfonate group, or a sulfonic acid ester group. As polymers having a sulfonic acid group, a sulfonate group, or a sulfonic acid ester group, particularly preferably polymers containing 2% by mass or more of an acrylamide monomer or a methacrylamide monomer having a sulfonic acid group in the copolymerization ratio, and more preferably polymers containing 5% by mass or more of an acrylamide monomer or a methacrylamide monomer having a sulfonic acid group.

[0130] The glass transition temperature (Tg) of the charge control resin is preferably from 35°C to 90°C, the peak molecular weight (Mp) is from 10,000 to 30,000, and the weight average molecular weight (Mw) is from 25,000 to 50,000. When using such a charge control resin, desired triboelectric charging properties can be imparted without affecting the required thermal properties of the toner particles. In addition, when the charge control resin contains a sulfonic acid group, for example, the dispersibility of the charge control resin itself and the dispersibility of a colorant and the like in the polymerizable monomer composition are improved, and the coloring power, transparency, and triboelectric charging characteristics can be further improved.

[0131] These charge control agents or charge control resins can be added alone or in combination of two or more. The addition amount of the charge control agent or charge control resin is preferably from 0.01 parts by mass to 20.0 parts by mass, more preferably from 0.5 parts by mass to 10.0 parts by mass, based on 100.0 parts by mass of the binder resin.

[0132] <Method for producing toner>

[0133] The method for producing the toner is not particularly limited, and known methods such as a pulverization method, a suspension polymerization method, a dissolution suspension method, an emulsion aggregation method, and a dispersion polymerization method can be used. Here, the toner is preferably produced by an emulsion aggregation method.

[0134] The method for producing the toner successively includes the following steps (1) to (3):

[0135] (1) A dispersion step of preparing a dispersion of resin fine particles including a resin such as a binder resin, and a dispersion step of preparing a dispersion of wax fine particles containing an ester wax.

[0136] (2) An aggregation step of aggregating the resin fine particles contained in the resin fine particle dispersion with the wax fine particles containing an ester wax to form aggregates.

[0137] (3) A fusing step of heating the aggregates and fusing them.

[0138] Preferably, in the method for producing the toner, a boron compound is added in the aggregation step and / or the fusing step.

[0139] In addition, preferably, during or after the fusing step, the following steps (4) to (6) are successively included:

[0140] (4) A spheroidization step of further raising the temperature and heating the aggregates;

[0141] (5) A cooling step of cooling the aggregates at a cooling rate of 0.1°C / second or more; and

[0142] (6) An annealing step of heating and maintaining the aggregate at a temperature equal to or higher than the crystallization temperature or glass transition temperature of the resin.

[0143] The toner is preferably produced by the emulsion aggregation method because the toner shape can be controlled and boric acid is easily uniformly dispersed near the surface of the toner. Details of the emulsion aggregation method are described below.

[0144] <Emulsion Aggregation Method>

[0145] In the emulsion aggregation method, an aqueous dispersion of fine particles made of a constituent material of toner particles that are sufficiently smaller than the target particle size is prepared in advance, and the fine particles are aggregated in an aqueous medium until the fine particles reach the particle size of the toner particles, and the resin is fused by heating or the like to produce toner particles.

[0146] In other words, in the emulsion aggregation method, a dispersion step of preparing a fine particle dispersion liquid composed of a constituent material of toner particles, an aggregation step of aggregating fine particles composed of a constituent material of toner particles and controlling the particle size until the particle size becomes the particle size of toner particles, a fusion step of fusing the resin contained in the obtained aggregated particles, a spheroidization step of further melting and controlling the surface shape of the toner by heating or the like, a subsequent cooling step, a metal removal step of filtering the obtained toner and removing excess polyvalent metal ions, a filtration and washing step of washing with ion-exchanged water or the like, and a step of removing moisture from the washed toner particles and drying are used to produce toner particles.

[0147] (Preparation Step of Resin Fine Particle Dispersion Liquid (Dispersion Step))

[0148] The resin fine particle dispersion liquid can be prepared by known methods, but is not limited to these methods. Known methods include, for example, emulsion polymerization method, self-emulsification method, phase inversion emulsification method of emulsifying resin by adding an aqueous medium to a resin solution obtained by dissolving in an organic solvent, and forced emulsification method of forcibly emulsifying resin by high-temperature treatment in an aqueous medium without using an organic solvent.

[0149] Specifically, the resin is dissolved in an organic solvent capable of dissolving the resin, and a surfactant and a basic compound are added. In the case where the resin is a crystalline resin having a melting point, the resin can be dissolved by heating to a temperature above its melting point. Then, while stirring with a homogenizer or the like, an aqueous medium is slowly added to precipitate resin fine particles. After that, the solvent is removed by heating or reduced pressure to prepare an aqueous dispersion liquid of resin fine particles. Any organic solvent capable of dissolving the resin can be used to dissolve the resin, but from the viewpoint of suppressing the generation of coarse powder, an organic solvent that forms a homogeneous phase with water such as toluene is preferably used.

[0150] The surfactant used in the above emulsification is not particularly limited, and examples thereof include anionic surfactants such as sulfate esters and salts, sulfonates, carboxylates, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycol-based, alkylphenol ethylene oxide adduct-based, and polyol-based surfactants. The surfactant can be used alone or in combination of two or more.

[0151] Examples of the basic compound used in the dispersion step include inorganic bases such as sodium hydroxide and potassium hydroxide, and organic bases such as ammonia, triethylamine, trimethylamine, dimethylaminoethanol, and diethylaminoethanol. The basic compound can be used alone or in combination of two or more.

[0152] The 50% particle size (D50) based on the volume distribution of the resin fine particles in the aqueous dispersion of the resin fine particles is preferably from 0.05 μm to 1.0 μm, more preferably from 0.05 μm to 0.4 μm. By adjusting the 50% particle size (D50) based on the volume distribution to the above range, toner particles having a volume average particle size of 3 μm to 10 μm can be easily obtained, which is an appropriate size for the toner particles.

[0153] The 50% particle size (D50) based on the volume distribution is measured using a dynamic light scattering type particle size distribution analyzer Nanotrac UPA-EX150 (manufactured by Nikkiso Co., Ltd.).

[0154] <Wax fine particle dispersion>

[0155] The wax fine particle dispersion containing an ester wax can be prepared by the following known methods, but is not limited thereto.

[0156] The wax fine particle dispersion can be prepared as follows: The wax is added to an aqueous medium containing a surfactant, heated to a temperature above the melting point of the wax, and dispersed into particles by using a homogenizer having a strong shearing ability (for example, "Clearmix WMotion", manufactured by M Technique Co., Ltd.) or a pressure discharge type disperser (for example, "Gaulin homogenizer", manufactured by Gaulin Co., Ltd.), and then cooled to a temperature below the melting point of the wax.

[0157] The dispersed particle size of the wax fine particle dispersion in the aqueous dispersion, based on the 50% particle size (D50) of the volume distribution, is preferably from 0.03 μm to 1.0 μm, more preferably from 0.1 μm to 0.5 μm. It is also preferred that there are no coarse particles larger than 1 μm.

[0158] The dispersed particle size of the fine wax particles dispersion in an aqueous medium can be measured using a dynamic light scattering type particle size distribution analyzer (Nanotrac UPA-EX150, manufactured by Nikkiso Co., Ltd.).

[0159] <Fine particle dispersion of colorant>

[0160] The fine particle dispersion of colorant can be used as needed. The fine particle dispersion of colorant can be prepared by the following known methods, but is not limited thereto. Thus, the fine particle dispersion of colorant can be prepared by mixing a colorant, an aqueous medium, and a dispersant using a mixer such as a known stirrer, emulsifier, or disperser. The dispersant used here can be a known dispersant such as a surfactant or a polymer dispersant.

[0161] Both the surfactant and the polymer dispersant can be removed in the washing step described below, but from the viewpoint of washing efficiency, the surfactant is preferred.

[0162] Surfactants include anionic surfactants such as sulfate esters and salts, sulfonates, phosphate esters, and soaps; cationic surfactants such as amine salts and quaternary ammonium salts; and nonionic surfactants such as polyethylene glycol-based, alkylphenol ethylene oxide adduct-based, and polyol-based surfactants. Among them, nonionic surfactants or anionic surfactants are preferred. Nonionic surfactants and anionic surfactants can also be used in combination. Surfactants can be used alone or in combination of two or more. The concentration of the surfactant in the aqueous medium is preferably 0.5% by mass to 5% by mass.

[0163] The content of the fine colorant particles in the fine particle dispersion of colorant is not particularly limited, but is preferably 1% by mass to 30% by mass based on the total mass of the fine particle dispersion of colorant.

[0164] In addition, from the viewpoint of the dispersibility of the colorant in the finally obtained toner, the dispersed particle size of the fine colorant particles in the aqueous dispersion of the colorant is preferably 0.5 μm or less in terms of the 50% particle size (D50) based on the volume distribution. For the same reason, it is preferably 2 μm or less in terms of the 90% particle size (D90) based on the volume distribution. The dispersed particle size of the colorant particles dispersed in the aqueous medium is measured using a dynamic light scattering particle size distribution analyzer (Nanotrac UPA-EX150, manufactured by Nikkiso Co., Ltd.).

[0165] Examples of conventional mixers such as stirrers, emulsifiers, and dispersers used for dispersing the colorant in the aqueous medium include ultrasonic homogenizers, jet mills, pressure homogenizers, colloid mills, ball mills, sand mills, and paint stirrers. These can be used alone or in combination.

[0166] (Mixing step)

[0167] In the mixing step, a mixed liquid is prepared by mixing a resin fine particle dispersion liquid, a wax fine particle dispersion liquid, and, if necessary, a colorant fine particle dispersion liquid. This can be accomplished using known mixing devices such as homogenizers and mixers.

[0168] (Step of forming aggregate particles (aggregation step))

[0169] In the aggregation step, the fine particles contained in the mixed liquid prepared in the mixing step are aggregated to form aggregates having a desired particle size. At this time, a flocculant is added and mixed, and heating and / or mechanical power are appropriately applied as needed to form aggregates in which the resin fine particles, wax fine particles, and colorant fine particles are aggregated.

[0170] Examples of the flocculant include organic flocculants such as quaternary salt cationic surfactants and polyethyleneimine, and inorganic flocculants such as inorganic metal salts such as sodium sulfate, sodium nitrate, sodium chloride, calcium chloride, and calcium nitrate, inorganic ammonium salts such as ammonium sulfate, ammonium chloride, and ammonium nitrate, and metal complexes of divalent or higher valences. An acid can also be added to lower the pH and cause soft aggregation; for example, sulfuric acid or nitric acid can be used.

[0171] The flocculant can be added in the form of a dry powder or an aqueous solution obtained by dissolving it in an aqueous medium, but in order to cause uniform aggregation, it is preferably added in the form of an aqueous solution. In addition, the addition and mixing of the flocculant are preferably carried out at a temperature below the glass transition temperature or melting point of the resin contained in the mixed liquid. By mixing under this temperature condition, the aggregation proceeds more uniformly. The flocculant can be mixed into the mixed liquid using known mixing devices such as homogenizers or mixers. In the aggregation step, aggregates of toner particle size are formed in an aqueous medium. The volume average particle size of the aggregates produced in the aggregation step is preferably 3 μm to 10 μm. The volume average particle size can be measured using a particle size distribution analyzer (Coulter Multisizer 3, manufactured by Beckman Coulter Inc.) using the Coulter method.

[0172] (Shell formation step of further adding resin fine particles containing a shell resin to the dispersion liquid containing aggregates and aggregating to form aggregates having a shell)

[0173] Preferably, after forming aggregated particles (core particles) by an aggregation step, resin fine particles containing a shell resin are further added and aggregated to form a shell in a shell formation step. That is, preferably, the toner particles have core particles containing a binder resin and a shell on the surface of the core particles. As the shell resin, the same resin as the binder resin or a different resin can be used. The addition amount of the shell resin is preferably 5 to 40 parts by mass, more preferably 10 to 35 parts by mass, relative to 100 parts by mass of the binder resin contained in the core particles.

[0174] The shell resin is not particularly limited, and the above resins used as the binder resin can be used. The shell resin preferably contains a polyester resin. As the shell resin, a polyester resin having the above monomer units corresponding to dodecenyl succinic acid can be used.

[0175] When forming the shell, preferably, compound A is further added together with the resin fine particles containing the shell resin to the dispersion liquid containing the aggregates, so that compound A is included in the toner particles. This is because by adding compound A when forming the shell, compound A can be present in the binder resin and on the toner surface.

[0176] In addition, when forming the shell, in order to promote the inclusion of boron in the toner particles, preferably, a boron compound is added together with the resin fine particles containing the shell resin to the dispersion liquid containing the aggregates in the shell formation step.

[0177] The boron compound can be boric acid, or a compound that can be changed to boric acid during toner production by pH control or the like. For example, at least one selected from the group consisting of boric acid, borax, organic boric acid, borate, and borate ester can be used. For example, a boron compound can be added and controlled to include boric acid in the aggregates. Preferably, the pH is controlled to acidic conditions in the aggregation step, and the shell formation step is carried out.

[0178] In the shell formation step, the presence of boric acid is favorable for the uniform aggregation of the shell resin on the core particles, so that the area of the domain near the surface can be reduced.

[0179] Boric acid can exist in the aggregates in an unsubstituted state. The boron compound is preferably at least one selected from the group consisting of boric acid and borax. When producing a toner in an aqueous medium, from the viewpoints of reactivity and production stability, it is preferable to add a borate as the boron compound. Specifically, the boron compound more preferably contains at least one selected from the group consisting of sodium tetraborate, borax, and ammonium borate, and is more preferably borax.

[0180] Borax is represented by the decahydrate of sodium tetraborate Na2B4O7 and turns into boric acid in an acidic aqueous solution. Therefore, when using a boron compound in an acidic environment in an aqueous medium, it is preferable to use borax. The addition method may include either dry powder or an aqueous solution obtained by dissolving it in an aqueous medium. However, in order to cause uniform aggregation, it is preferable to add borax in the form of an aqueous solution. The concentration of the aqueous solution can be appropriately changed according to the concentration of borax included in the toner, for example, 1 mass% to 20 mass%. In order to turn borax into boric acid, it is preferable to set the pH to acidic conditions before, during, or after the addition. For example, the pH can be controlled to 1.5 to 5.0, preferably 2.0 to 4.0.

[0181] (Step of obtaining a dispersion containing toner particles (fusing step))

[0182] In the fusing step, first, under stirring in the same manner as in the aggregation step, aggregation is stopped in the dispersion containing the aggregates obtained in the aggregation step. Aggregation is stopped by adding an aggregation terminator such as a base capable of adjusting the pH, a chelating compound, or an inorganic salt compound such as sodium chloride.

[0183] After the dispersion state of the aggregated particles in the dispersion becomes stable due to the action of the aggregation terminator, the dispersion is heated to a temperature above the glass transition temperature or melting point of a resin such as a binder resin, and the aggregated particles are fused and adjusted to a desired particle size. The volume-based 50% particle size (D50) of the toner particles is preferably 3 μm to 10 μm.

[0184] (Step of obtaining a desired surface shape of the toner (spheroidization step))

[0185] During or after the fusing step, it is preferable to perform a spheroidization step in which the temperature is further increased and maintained until the toner particles have a desired roundness or surface shape. The specific temperature in the spheroidization step is, for example, 85 °C or higher, preferably 90 °C or higher, and preferably 95 °C or lower. The heating time in the spheroidization step includes heating times of 1 hour or more, 2 hours or more, and 3 hours or more. The upper limit is, for example, 5 h or less. This step makes it easy to form hydrogen bonds derived from boric acid in the toner particles.

[0186] (Cooling step)

[0187] After the spheroidization step, a cooling step is preferably carried out, in which the temperature of the dispersion containing the obtained toner particles is lowered to a temperature lower than the crystallization temperature or the glass transition temperature of resin components such as binder resin and wax components such as hydrocarbon wax and ester wax by controlling the cooling rate. By the cooling step, the change in the domain shape accompanying the crystallization of the crystalline components of the wax can be suppressed. As a result, it becomes easier to control the proportion of the domain area of the crystalline components of the ester wax near the surface of the toner particles.

[0188] The specific cooling rate is 0.1 °C / second or more, preferably 0.5 °C / second or more, more preferably 2 °C / second or more, and even more preferably 4 °C / second or more. The upper limit is, for example, 20 °C / second or less or 15 °C / second or less.

[0189] (Annealing step)

[0190] After the cooling step, an annealing step of heating the toner particles to a temperature above the crystallization temperature or the glass transition temperature of the resin and below the crystallization temperature of the wax can be carried out. By the annealing step, the crystalline components compatible with the resin of the toner particles can be crystallized, further suppressing the change in the domain shape.

[0191] (Post-treatment step)

[0192] In the method for producing toner, post-treatment steps such as a washing step, a solid-liquid separation step, and a drying step can be further carried out, and by carrying out the above post-treatment steps, dry toner particles can be obtained.

[0193] (External addition step)

[0194] The obtained toner particles can be used as toner as they are, but in the external addition step, external additives such as fine silica particles can be added to the outside of the toner particles obtained in the drying step.

[0195] As external addition conditions, by changing the rotation speed rpm of the stirring spring provided in the external addition machine and the external addition time, the adhesion state of the external additive and the coating state of the external additive on the toner particles can be controlled as needed.

[0196] To make the particles adhere more firmly, it is effective to increase the rotation speed and extend the external addition time. In particular, the adhesion strength can be increased by increasing the rotation speed. In addition, since the external addition particles with a small particle size form aggregates, the external addition conditions are controlled to carry out a depolymerization treatment while coating the toner particles with the external additive. The depolymerization performance can be improved by increasing the rotation speed and extending the external addition time, but to further promote depolymerization while suppressing the adhesion strength, it is effective to lower the rotation speed and extend the external addition time.

[0197] The weight average particle diameter (D4) of the toner is preferably from 4.0 μm to 12.0 μm, more preferably from 4.0 μm to 8.0 μm.

[0198] [Method for Measuring Physical Properties]

[0199] Next, the method for measuring the physical properties of the present disclosure will be described.

[0200] <Measurement of Weight Average Particle Diameter (D4) and Number Average Particle Diameter (D1) of Toner or Toner Particles>

[0201] The weight average particle diameter (D4) and number average particle diameter (D1) of the toner or toner particles are measured using a precision particle size distribution measuring device “Coulter Counter Multisizer3” (registered trademark, manufactured by Beckman Coulter, Inc.) equipped with a 100 μm aperture tube and its dedicated software “Beckman Coulter Multisizer 3 Version 3.51” (manufactured by Beckman Coulter, Inc.) for setting measurement conditions and analyzing measurement data, with the effective number of measurement channels being 25,000, and the measurement data is analyzed and calculated.

[0202] The electrolyte aqueous solution for measurement is an electrolyte aqueous solution obtained by dissolving special grade sodium chloride in ion-exchanged water to a concentration of about 1% by mass. For example, “ISOTON II” (manufactured by Beckman Coulter, Inc.) can be used.

[0203] Before measurement and analysis, the dedicated software is set as follows.

[0204] In the “Change Standard Measurement Method (SOM) screen” of the dedicated software, the total count in the control mode is set to 50,000 particles, the number of measurements is set to 1 time, and the Kd value is set to the value obtained using “Standard Particle 10.0 μm” (manufactured by Beckman Coulter, Inc.). By pressing the threshold / noise level measurement button, the threshold and noise level are automatically set. In addition, the current is set to 1600 μA, the gain is set to 2, the electrolyte solution is set to ISOTON II, and the aperture tube flushing after measurement is checked.

[0205] In the “Pulse to Particle Size Conversion Setting screen” of the dedicated software, the element interval is set to logarithmic particle size, the particle size element is set to 256 particle size elements, and the particle size range is set to 2 μm to 60 μm.

[0206] The specific measurement method is as follows.

[0207] (1) Pour approximately 200 mL of the electrolyte aqueous solution into a 250 mL round-bottom glass beaker dedicated to the Multisizer 3. Place the beaker on the sample holder and stir with a stirring rod counterclockwise at 24 revolutions per second. Then, use the "mouthpiece flushing" function of the dedicated software to remove dirt and bubbles from the inside of the mouthpiece.

[0208] (2) Pour approximately 30 mL of the electrolyte aqueous solution into a 100 mL flat-bottom glass beaker, and add approximately 0.3 mL of a solution obtained by diluting "Contaminon N" (a 10% aqueous solution of a neutral detergent for cleaning precision measuring instruments composed of a nonionic surfactant, an anionic surfactant, and an organic builder, pH 7, manufactured by Wako Pure Chemical Industries, Ltd.) three times (by mass) with ion-exchanged water as a dispersant.

[0209] (3) Place a specified amount of ion-exchanged water in the water tank of the ultrasonic disperser "Ultrasonic Dispersion System Tetora 150" (manufactured by Nikkaki Bios Co., Ltd.). This ultrasonic disperser has two built-in oscillators with an oscillation frequency of 50 kHz and an electrical output of 120 W and a phase shift of 180 degrees, and add approximately 2 mL of Contaminon N to the water tank.

[0210] (4) Set the beaker of (2) in the beaker fixing hole of the ultrasonic disperser and operate the ultrasonic disperser. Adjust the height position of the beaker so that the resonance state of the liquid level of the electrolyte aqueous solution in the beaker becomes maximum.

[0211] (5) When irradiating the electrolyte aqueous solution in the beaker of (4) with ultrasonic waves, gradually add approximately 10 mg of toner or toner particles to the electrolyte aqueous solution and disperse them. Then, further continue the ultrasonic dispersion treatment for 60 seconds. During the ultrasonic dispersion, appropriately adjust the water temperature of the water tank to 10 °C to 40 °C.

[0212] (6) Using a pipette, drop the electrolyte aqueous solution of (5) in which the toner or toner particles are dispersed into the round-bottom beaker of (1) placed on the sample stage, and adjust the measurement concentration to approximately 5%. Perform the measurement until the number of measured particles reaches 50,000.

[0213] (7) Analyze the measurement data using the dedicated software set in the device and calculate the weight-average particle diameter (D4). When the dedicated software is set to Chart / Volume%, the "average diameter" on the Analysis / Volume Statistics (arithmetic mean) screen is the weight-average particle diameter (D4), and when the dedicated software is set to Chart / Number%, the "average diameter" on the Analysis / Number Statistics (arithmetic mean) screen is the number-average particle diameter (D1).

[0214] <Measurement of Acid Value>

[0215] The acid value is the number of milligrams of potassium hydroxide required to neutralize the acid contained in 1 g of the sample. The acid value of the resin is measured according to JIS K0070 - 1992. Specifically, the measurement is carried out according to the following procedure.

[0216] (1) Preparation of Reagents

[0217] Dissolve a total of 1.0 g of phenolphthalein in 90 mL of ethanol (95 vol%) and add ion - exchanged water to make 100 mL to obtain a phenolphthalein solution.

[0218] Dissolve a total of 7 g of special - grade potassium hydroxide in 5 mL of water, add ethanol (95 vol%) to make 1 L. Put the solution in an alkali - resistant container, avoid contact with carbon dioxide, etc., let it stand for 3 days, then filter to obtain a potassium hydroxide solution. Store the obtained potassium hydroxide solution in an alkali - resistant container. Place a total of 25 mL of 0.1 mol / L hydrochloric acid in a conical flask, add a few drops of phenolphthalein solution, and titrate with the potassium hydroxide solution. The factor of the potassium hydroxide solution is determined by the amount of the potassium hydroxide solution required for neutralization. The 0.1 mol / L hydrochloric acid used is prepared according to JIS K 8001 - 1998.

[0219] (2) Procedure

[0220] (a) Main Test

[0221] Weigh out a total of 2.0 g of the crushed resin sample into a 200 - mL conical flask, add 100 mL of a toluene / ethanol (2:1) mixed solution, and dissolve for 5 hours. Then, add a few drops of phenolphthalein solution as an indicator and titrate with the potassium hydroxide solution. The end - point of the titration is that the light red color of the indicator persists for 30 seconds.

[0222] (B) Blank Test

[0223] Carry out the titration in the same manner as above, except that no sample is used (i.e., only the toluene / ethanol (2:1) mixed solution is used).

[0224] (3) Substitute the obtained results into the following formula to calculate the acid value.

[0225] A = [(C - B)×f×5.61] / S

[0226] Here, A is the acid value (mgKOH / g), B is the amount of the potassium hydroxide solution added in the blank test (mL), C is the amount of the potassium hydroxide solution added in the main test (mL), f is the factor of the potassium hydroxide solution, and S is the mass of the sample (g).

[0227] <Method for Measuring Hydroxyl Value>

[0228] The hydroxyl value is the number of milligrams of potassium hydroxide required to neutralize the acetic acid bonded to the hydroxyl groups when acetylating 1 g of the sample. The hydroxyl value of the binder resin is measured according to JIS K 0070-1992. Specifically, the measurement is carried out according to the following procedure.

[0229] (1) Preparation of reagents

[0230] Place a total of 25 g of special grade acetic anhydride in a 100 mL measuring flask, add pyridine to make the total volume 100 mL, shake the flask well to obtain the acetylation reagent. Store the obtained acetylation reagent in a brown bottle to avoid contact with moisture, carbon dioxide, etc. Dissolve a total of 1.0 g of phenolphthalein in 90 mL of ethanol (95 vol%) and add ion-exchanged water to make 100 mL to obtain the phenolphthalein solution.

[0231] Dissolve a total of 35 g of special grade potassium hydroxide in 20 mL of water, add ethanol (95 vol%) to make 1 L. Put the solution in an alkali-resistant container, avoid contact with carbon dioxide, etc., let it stand for 3 days, and then filter to obtain the potassium hydroxide solution. Store the obtained potassium hydroxide solution in an alkali-resistant container. Place a total of 25 mL of 0.5 mol / L hydrochloric acid in a conical flask, add a few drops of phenolphthalein solution, and titrate with the potassium hydroxide solution. The factor of the potassium hydroxide solution is determined by the amount of the potassium hydroxide solution required for neutralization. The 0.5 mol / L hydrochloric acid used is prepared according to JIS K 8001-1998.

[0232] (2) Procedure

[0233] (a) Main test

[0234] Accurately weigh a total of 1.0 g of the sample into a 200 mL round-bottom flask, and accurately add 5.0 mL of the acetylation reagent thereto using a Hall pipette. In this case, when the sample is difficult to dissolve in the acetylation reagent, add a small amount of special grade toluene to cause dissolution.

[0235] Place a small funnel on the mouth of the flask, and heat the flask with the bottom part immersed in a glycerol bath at about 97 °C for about 1 cm. To prevent the temperature of the neck of the flask from rising due to the heating of the bath, it is preferable to cover the base of the neck of the flask with cardboard with round holes.

[0236] After 1 hour, take the flask out of the glycerol bath and let it cool. After cooling, add 1 mL of water from the funnel and shake the flask to hydrolyze the acetic anhydride. To further complete the hydrolysis, heat the flask in the glycerol bath again for 10 minutes. After cooling, wash the funnel and the wall of the flask with 5 mL of ethanol.

[0237] Add a few drops of phenolphthalein solution as an indicator and titrate with the potassium hydroxide solution. The end point of the titration is that the light red color of the indicator persists for about 30 seconds.

[0238] (B) Blank test

[0239] Titration is carried out in the same manner as described above, except that the sample is not used.

[0240] (3) Substitute the obtained result into the following formula to calculate the hydroxyl value.

[0241] A = [{(B - C) × 28.05 × f} / S] + D

[0242] Here, A is the hydroxyl value (mgKOH / g), B is the added amount (mL) of potassium hydroxide solution in the blank test, C is the added amount (mL) of potassium hydroxide solution in the main test, f is the factor of the potassium hydroxide solution, S is the mass (g) of the sample, and D is the acid value (mgKOH / g) of the sample.

[0243] <Method for measuring the content ratio of monomer units corresponding to dodecenyl succinic acid based on the mass of the binder resin>

[0244] A pyrolysis gas chromatography - mass spectrometer (hereinafter referred to as pyrolysis GC / MS) and NMR are used to measure the content ratio of monomer units corresponding to dodecenyl succinic acid based on the mass of the binder resin.

[0245] Specifically, the following operations are performed.

[0246] (1) Weigh precisely a total of 50 mg of toner into an 8 - mL glass sample bottle, add 1 mL of deuterated chloroform, cover the bottle, and disperse and dissolve the toner with an ultrasonic disperser for 1 hour. Next, filter through a 0.4 - μm membrane filter and collect the filtrate. At this time, the deuterated chloroform - insoluble matter remains on the membrane filter.

[0247] (2) Perform 1 1H - NMR and 13 13C - NMR measurements, assign the components contained in the toner from the spectra, and calculate the content ratio of the monomer units corresponding to dodecenyl succinic acid contained in the toner.

[0248] (3) In the case of insufficient identification, further analysis is carried out by pyrolysis GC / MS, and derivatization treatment such as methylation is performed as required, and then composition analysis is carried out.

[0249] (4) Calculate the amount of binder resin in the toner according to the "Method for measuring the ester wax content in the toner" described later. From these values, the content ratio of monomer units corresponding to dodecenyl succinic acid based on the mass of the binder resin can be calculated.

[0250] (NMR measurement conditions)

[0251] Bruker AVANCE 500, manufactured by Bruker Biospin Co., Ltd.

[0252] Nuclei measured: 1 H, 13 C

[0253] Measurement frequency: 500.1 MHz

[0254] Number of integrations: 16 times, 2048 times

[0255] Measurement temperature: room temperature

[0256] (Pyrolysis GC / MS measurement conditions)

[0257] Pyrolysis device: TPS-700, manufactured by Japan Analytical Industry Co., Ltd.

[0258] Pyrolysis temperature: Optimal value from 400 °C to 600 °C

[0259] GC / MS device: ISQ manufactured by Thermo Fisher Scientific Inc.

[0260] Column: "HP5-MS" (Agilent / 19091S-433), length 30 m, inner diameter 0.25 mm, film thickness 0.25 μm GC / MS conditions

[0261] Inlet conditions:

[0262] Inlet temperature: 250 °C

[0263] Split flow: 50 mL / min

[0264] GC temperature programming conditions: 40 °C (5 min) → 10 °C / min (300 °C) → 300 °C (20 min)

[0265] <Measurement of molecular weight of polyester resin>

[0266] The molecular weight (weight-average molecular weight Mw) of the polyester resin was measured by gel permeation chromatography (GPC) as follows.

[0267] First, the polyester resin was dissolved in tetrahydrofuran (THF) at room temperature for 24 hours. Then the resulting solution was filtered through a solvent-resistant membrane filter "MyShori Disc" (manufactured by Tosoh Corporation) with a pore size of 0.2 μm to obtain a sample solution. The sample solution was adjusted so that the concentration of the components soluble in THF was 0.8 mass%. This sample solution was used for measurement under the following conditions.

[0268] - Equipment: HLC8120 GPC (Detector: RI) (manufactured by Tosoh Corporation)

[0269] - Column: Shodex LF-404, LF-404 in series (manufactured by Showa Denko Corporation)

[0270] - Eluent: Tetrahydrofuran (THF)

[0271] - Flow rate: 1.0 mL / minute

[0272] - Oven temperature: 40.0 °C

[0273] - Sample injection volume: 0.10 mL

[0274] To calculate the molecular weight of the sample, a molecular weight calibration curve prepared using a standard polystyrene resin (e.g., product names “TSK Standard Polystyrene F-850, F-450, F-288, F-128, F-80, F-40, F-20, F-10, F-4, F-2, F-1, A-5000, A-2500, A-1000, A-500”, manufactured by Tosoh Corporation) was used.

[0275] <Identification of the molecular structure of the ester wax contained in the toner>

[0276] First, the wax contained in the toner was separated from the toner through the following separation steps. The toner was dispersed in ethanol, which is a poor solvent for the toner, and the temperature was raised above the melting point of the wax. At this time, pressure can be applied as needed. The wax, whose temperature exceeded its melting point as a result of this step, was melted and extracted into ethanol. In the case of heating and further applying pressure, the wax can be separated from the toner by performing solid-liquid separation while still under pressure. Then the extract was dried and solidified to obtain the wax. By classifying the obtained wax according to molecular weight, the ester wax can be separated. This separation step enables the separation of the ester wax even when waxes other than the ester wax are mixed in.

[0277] Next, the molecular structure of the separated ester wax was identified. A pyrolysis gas chromatography mass spectrometer (hereinafter referred to as pyrolysis GC / MS) and NMR were used to identify the molecular structure.

[0278] Specifically, the following steps were performed.

[0279] (1) A total of 50 mg of the toner was precisely weighed into an 8 mL glass sample bottle, 1 mL of deuterated chloroform was added, the bottle was capped, and the toner was dispersed and dissolved for 1 hour using an ultrasonic disperser. Next, filtration was performed through a 0.4 μm membrane filter, and the filtrate was collected. At this time, the deuterated chloroform-insoluble matter remained on the membrane filter.

[0280] (2) Perform 1H-NMR measurement on the filtrate, and the spectrum is attributed to the ester wax.

[0281] (3) Analyze by pyrolysis GC / MS. Perform derivatization such as methylation as needed to calculate the molecular weight of the ester wax.

[0282] (NMR Measurement Conditions)

[0283] Bruker AVANCE 500, manufactured by Bruker Biospin Co., Ltd.

[0284] Nucleus Measured: 1 H

[0285] Measurement Frequency: 500.1 MHz

[0286] Number of Integration Times: 16 times

[0287] Measurement Temperature: Room temperature

[0288] (Pyrolysis GC / MS Measurement Conditions)

[0289] Pyrolysis Device: TPS-700, manufactured by Japan Analytical Industry Co., Ltd.

[0290] Pyrolysis Temperature: Optimal value from 400 °C to 600 °C

[0291] GC / MS Device: ISQ manufactured by Thermo Fisher Scientific Inc.

[0292] Column: "HP5-MS" (Agilent / 19091S-433), length 30 m, inner diameter 0.25 mm, film thickness 0.25 μm

[0293] GC / MS Conditions

[0294] Inlet Conditions:

[0295] Inlet Temperature: 250 °C

[0296] Split Flow: 50 mL / min

[0297] GC Temperature Rising Conditions: 40 °C (5 minutes) → 10 °C / min (300 °C) → 300 °C (20 minutes)

[0298] (Method for Measuring the Content of Ester Wax in the Toner)

[0299] The ester wax content W per 100 parts by mass of the binder resin in the toner is calculated by the following steps. First, find the mass X1 of the tetrahydrofuran (THF) soluble matter, the mass X2 of the insoluble matter, and the ash content X3 of the incineration residue of the insoluble matter in the toner. Then, the ester wax content W in the toner can be calculated.

[0300] Specifically, accurately weigh 1.5 g of the toner and place it in a pre-weighed cylindrical filter paper (product name: No. 86R, size 28×100 mm, manufactured by Advantec Toyo Co., Ltd.), and then place it in a Soxhlet extractor. Use 200 mL of tetrahydrofuran (THF) as the solvent for extraction for 20 hours. At this time, perform extraction at a reflux rate of one solvent extraction cycle every 5 minutes. After the extraction is completed, take out the cylindrical filter paper, air-dry it, and then vacuum-dry it at 40 °C for 8 hours. Weigh the mass of the cylindrical filter paper containing the extraction residue, and subtract the mass of the cylindrical filter paper to obtain the mass of the extraction residue as the mass X2 (g) of the tetrahydrofuran (THF) insoluble matter in the toner. The mass X1 (g) of the tetrahydrofuran (THF) soluble matter in the toner is calculated using the following formula (A):

[0301] X1 = 1.5 - X2 (A)

[0302] Next, measure the content X3 (g) of the components other than the resin component according to the following steps. Accurately weigh a total of 1.5 g of the toner into a pre-weighed 30 mL porcelain crucible. Place the porcelain crucible in an electric furnace and heat it at 900 °C for 3 hours, let it cool in the electric furnace, and then let it cool in a desiccator at room temperature for at least 1 hour. Weigh the mass of the crucible containing the incineration residue ash, and subtract the mass of the crucible to calculate the incineration residue ash content X3 (g).

[0303] Furthermore, filter the extract obtained through the above operations through a solvent-resistant membrane filter “MyShori Disc” (manufactured by Tosoh Corporation) with a pore size of 0.2 μm to obtain a sample solution. This sample solution is used for measurement under the following conditions.

[0304] Equipment: HLC8320 GPC (detector: RI) (manufactured by Tosoh Corporation)

[0305] Column: Shodex LF-404, LF-404 in series (manufactured by Showa Denko Corporation)

[0306] Eluent: tetrahydrofuran (THF)

[0307] Flow rate: 1.0 mL / minute

[0308] Oven temperature: 40.0 °C

[0309] Sample injection volume: 0.10 mL

[0310] The total area S of the molecular weight distribution of the tetrahydrofuran (THF)-soluble matter in the toner and the area P of the ester wax having the same molecular weight as the wax identified by the above method can be used to calculate the amount w of the ester wax in the toner using the following calculation formula (B).

[0311] w = (X1 × P / S) = {(1.5 - X2) × P / S} (B)

[0312] In addition, the total area S of the molecular weight distribution of the tetrahydrofuran (THF)-soluble matter in the toner and the area Pw derived from all waxes can be determined by the above GPC, and the amount R of the binder resin in the toner can be calculated by the following formula (R).

[0313] R = {X1 + (X2 - X3)} - (X1 × Pw / S) (R)

[0314] The content of the ester wax relative to 100 parts by mass of the binder resin can be determined from the obtained amount w of the ester wax and the amount R of the binder resin.

[0315] <Calculation method of SP value of ester wax>

[0316] The SP value of the ester wax is calculated as follows according to the calculation method proposed by Fedors.

[0317] When calculating the SP value of the ester wax (cal / cm 3 ) 0.5 the evaporation energy (Δei) (cal / mol) and molar volume (Δvi) (cm 3 / mol) of the atoms or atomic groups in the molecular structure of the identified ester wax are obtained from the table in "Polym. Eng. Sci., 14(2), 147 - 154(1974)" and calculated by the following formula (4).

[0318] Formula (4): SP value of ester wax = (ΣΔei / ΣΔvi) 0.5

[0319] <Measurement of extraction amount of compound A extracted with ethanol>

[0320] Using 1 1H-NMR (nuclear magnetic resonance) measurement, the extraction amount of compound A extracted from the toner with ethanol is measured in the following manner.

[0321] First, 50 mL of ethanol and 5 g of toner were weighed and mixed thoroughly in a sample bottle, and then ultrasonic waves were applied for 30 minutes using a tabletop ultrasonic cleaner (product name "B2510JMTH", manufactured by Branson Co.) at an oscillation frequency of 42 kHz and an electrical output of 125 W. Then, the mixture was filtered using a solvent-resistant membrane filter "MyShori Disc" (manufactured by Tosoh Corporation) having a pore size of 0.2 μm. Ethanol was removed from the filtrate using an evaporator, and the mixture was dissolved in deuterated chloroform containing 10 mg of trimethylsilane (TMS) (1% TMS), and the mixture was filtered by 1 H-NMR analysis was used to identify the structure of Compound A.

[0322] In addition, the identified compound A was 1 H-NMR measurement, the extraction amount (ppm) of compound A extracted from the toner was calculated using a calibration curve based on TMS intensity. The calibration curve was created from the TMS intensity and the peak intensity ratio of hydrogen derived from ethylene oxide groups around 3.0 ppm to 5.0 ppm. The measuring apparatus and conditions were as follows.

[0323] (NMR measurement conditions)

[0324] Bruker AVANCE 500, manufactured by Bruker Biospin Co.,Ltd.

[0325] Measurement core: 1 H

[0326] Measuring frequency: 500.1MHz

[0327] Number of points: 1024 times

[0328] Measuring temperature: room temperature

[0329] <Calculation of the average ratio As of the area occupied by the wax domains in the surface layer region from the toner particle surface to a depth of 200 nm>

[0330] The distribution state of the crystalline wax in the toner is evaluated by observing the cross section of the toner particle with a transmission electron microscope, calculating As from the cross-sectional area of ​​the domain formed by the crystalline wax, and averaging it for 100 arbitrarily selected toners.

[0331] Specifically, the toner was embedded in a visible light-curable embedding resin (D-800, manufactured by Nissin EM Co., Ltd.), cut into a thickness of 60 nm using an ultrasonic ultramicrotome (EM5, manufactured by Leica), and Ru stained using a vacuum staining device (manufactured by Filgen, Inc.). Subsequent observations were carried out using a transmission electron microscope (H7500, manufactured by Hitachi, Ltd.) at an acceleration voltage of 120 kV. For the toner cross-section to be observed, 100 particles with a weight-average particle size within ±2.0 μm were selected and photographed. The obtained images were processed using image processing software (Photoshop (registered trademark) 5.0, manufactured by Adobe Inc.) to clearly distinguish the domains of the crystalline wax component and the resin region. Specifically, the domains of the crystalline wax component can be distinguished as follows. By setting the brightness threshold (255 grayscale) to 160, the captured TEM image was binarized using the image processing software. At this time, the crystalline wax component of the toner and the photocurable resin D800 became bright regions, and the regions other than the crystalline resin component of the toner became dark regions. The outline of the toner could be distinguished by the light and dark of the toner and the photocurable resin.

[0332] Masking was performed to leave the surface layer region of the toner particle cross-section from the surface of the toner particle (outline of the cross-section) to a depth of 200 nm. Specifically, a dotted line was drawn from the center of gravity of the toner particle cross-section to a point on the outline of the toner particle cross-section. On this line, the position 200 nm from the outline in the direction of the center of gravity was identified. Then this operation was performed for one circumference of the toner particle cross-section outline, and the surface layer region up to 200 nm from the toner particle cross-section outline was clearly indicated. The area percentage occupied by the domain of the crystalline wax component in the area of the obtained surface layer region was calculated and expressed as As.

[0333] <Method for Quantifying Boron Atoms Based on the Mass of Toner Particles>

[0334] The content of boron (B) atoms based on the mass of toner particles was quantified using an inductively coupled plasma mass spectrometer (ICP-MS). As a pretreatment, the toner particles were subjected to the following acid decomposition to obtain a measurement solution for ICP-MS, and then ICP-MS measurement was performed so that the content of boron atoms in the toner particles could be quantified.

[0335] [Pretreatment]

[0336] Equipment: Microwave pretreatment device (ETHOS SEL), manufactured by Milestone General K.K.

[0337] Sample amount: 50 mg

[0338] A total of 5.00 mL of 68% nitric acid (for atomic absorption spectrometry, manufactured by Kanto Chemical Co.) was added to 50 mg of toner particles, and acid decomposition was performed using the above-mentioned apparatus. The acid decomposition was carried out in two stages to obtain the required measurement solution for ICP-MS. The acid decomposition conditions are as follows.

[0339] The first stage of acid decomposition

[0340] The heating temperature and holding time during acid decomposition were set as follows.

[0341] Room temperature, 60 °C (2 minutes), 40 °C (2 minutes), 160 °C (6 minutes), 220 °C (8 minutes), 180 °C (1 minute), 220 °C (4 minutes), 220 °C (held for 30 minutes), cooled to room temperature (25 °C).

[0342] The second stage of acid decomposition

[0343] The heating temperature and holding time during acid decomposition were set as follows.

[0344] A total of 3 mL of nitric acid was added, room temperature, 180 °C (5 minutes), 150 °C (1 minute), 220 °C (2 minutes), 220 °C (maintained for 27 minutes), cooled to room temperature (25 °C).

[0345] The solution obtained above was adjusted to a constant volume of 50 mL with ultrapure water. The resulting solution was further diluted 100 times with ultrapure water to obtain the measurement solution for ICP-MS.

[0346] [Quantitative analysis of boron atoms in toner particles using inductively coupled plasma mass spectrometry]

[0347] The content of boron atoms in the measurement solution for ICP-MS obtained above was quantified using the following apparatus and conditions.

[0348] Apparatus: Inductively coupled plasma mass spectrometer ICP-MS NexION 350D, PerkinElmer, Inc.

[0349] Measurement mode: Standard mode, calibration curve method

[0350] Measured element: Boron

[0351] Mass number: 11.0093

[0352] Scan mode: Peak hopping

[0353] Dwell time: 50 ms

[0354] Detector: Dual

[0355] Peristaltic pump speed: 20.0 rpm

[0356] Therefore, the content of boron atoms is quantified based on the mass of toner particles.

[0357] <Method for obtaining toner particles by removing external additives from toner>

[0358] Add a total of 160 g of sucrose (manufactured by Kishida Chemical Co., Ltd.) to 100 mL of ion-exchanged water, and dissolve it using a hot water bath to prepare a concentrated sucrose solution. Place 31 g of the concentrated sucrose solution and 6 mL of Contaminon N (10% aqueous solution of a neutral detergent for cleaning precision measuring instruments composed of a nonionic surfactant, an anionic surfactant, and an organic co-washing agent, pH 7, manufactured by Wako Pure Chemical Industries, Ltd.) in a centrifuge tube (capacity 50 mL). Add a total of 1.0 g of toner thereto, and break up the toner lumps with a spatula or the like. Shake the centrifuge tube at 300 spm (strokes per minute) for 20 minutes using a shaker (AS-1N, sold by AS ONE Corporation). After shaking, transfer the solution to a glass tube (50 mL) for a swinging rotor, and centrifuge it at 3500 rpm for 30 minutes in a centrifuge (H-9R, manufactured by Kokusan Co., Ltd.).

[0359] This operation separates the toner particles and the external additives. Visually confirm that the separation of the toner particles and the aqueous solution is sufficient, and collect the separated toner particles in the top layer with a spatula or the like. The collected toner particles are filtered through a vacuum filter and then dried in a dryer for more than 1 hour to obtain a measurement sample. This operation is performed multiple times to ensure the required amount.

[0360] Examples

[0361] The present disclosure will be described in more detail below using examples and comparative examples. Unless otherwise specified, the present disclosure is not limited in any way by the following examples. In the description of the following examples, "parts" are based on mass unless otherwise specified.

[0362] <Synthesis of polyester resin 1>

[0363]

[0364] Add the above-mentioned monomers to a flask equipped with a stirrer, a nitrogen inlet tube, a temperature sensor, and a distillation column. Heat the mixture to 195 °C within 1 hour and confirm that the reaction system is stirred evenly. Add a total of 1.2 parts by mass of tin distearate to 100 parts of these monomers. Then, raise the temperature from 195 °C to 240 °C within 5 hours while distilling off the generated water, and carry out the dehydration condensation reaction at 240 °C for another 2 hours. Then, lower the temperature to 190 °C, gradually add 40 parts by mass of trimellitic anhydride, and continue the reaction at 190 °C for 1 hour.

[0365] Thus, polyester resin 1 with an acid value of 19.9 mg KOH / g, a hydroxyl value of 31.7 mg KOH / g, and a weight-average molecular weight of 32,000 was obtained. The synthesis conditions and analysis results of polyester resin 1 are shown in Tables 1 and 2.

[0366] <Synthesis of polyester resins 2 - 9>

[0367] Except for changing the raw materials used in the synthesis example of polyester resin 1 as shown in Table 1, polyester resins 2 - 9 were obtained in the same manner as in the synthesis example of polyester resin 1. The synthesis conditions and analysis results of polyester resins 2 - 9 are shown in Tables 1 and 2.

[0368] Table 1

[0369]

[0370] BPA-2PO: Bisphenol A - propylene oxide 2 mol adduct

[0371] BPA-2EO: Bisphenol A - ethylene oxide 2 mol adduct

[0372] Table 2

[0373]

[0374] <Synthesis example of ester wax 1>

[0375] Add a total of 10 parts of ethylene glycol as an alcohol monomer and 100 parts of stearic acid as a carboxylic acid monomer to a reaction vessel equipped with a thermometer, a nitrogen inlet tube, a stirrer, a Dean - Stark trap, and a Dimroth condenser, and carry out the esterification reaction at 200 °C for 15 hours. Add 20 parts of toluene and 25 parts of isopropyl alcohol to the obtained ester compound, add 190 parts of a 10% potassium hydroxide aqueous solution equivalent to 1.5 times the acid value of the ester compound, and stir at 70 °C for 4 hours. Then, remove the water bath unit. Add a total of 20 parts of ion - exchanged water and stir at 70 °C for 1 hour, then remove the water bath unit and wash. Repeat the above washing steps until the pH of the removed water bath becomes neutral.

[0376] Then, the solvent was removed under reduced pressure at 200 °C and 1 kPa to obtain ethylene glycol distearate (ester wax 1), which is an ester compound of ethylene glycol and stearic acid, as the final product. The synthesis conditions and analysis results of the obtained ester wax 1 are shown in Tables 3 and 4.

[0377] <Production Examples of Ester Waxes 2 to 10>

[0378] Except for changing the raw materials used in the synthesis example of ester wax 1 as shown in Table 3, ester waxes 2 to 10 were obtained in the same manner as in the synthesis example of ester wax 1. The synthesis conditions and analysis results of the obtained ester waxes 2 to 10 are shown in Tables 3 and 4.

[0379] Table 3

[0380]

[0381] Table 4

[0382] Structure SP value Molecular weight Melting point Ester wax 1 Ethylene glycol distearate 8.85 595 79℃ Ester wax 2 1,10-Decanediol bis(triacontanoate) 8.72 1045 88℃ Ester wax 3 Behenyl sebacate 8.77 819 73℃ Ester wax 4 Ethylene glycol dibehenate 8.81 707 84℃ Ester wax 5 1,6-Hexanediol distearate 8.83 651 63℃ Ester wax 6 Ethylene glycol dipalmitate 8.88 539 77℃ Ester wax 7 Pentaerythritol tetrapalmitate 8.97 1090 69℃ Ester wax 8 Dipentaerythritol hexastearate 8.97 1853 77℃ Ester wax 9 Behenyl behenate 8.59 649 72℃ Ester wax 10 Dipentaerythritol hexapalmitate 9.01 1685 72℃

[0383] The unit of the SP value is (cal / cm3)0.5.

[0384] <Synthesis of Compound A1>

[0385] A total of 280 parts by mass of 1-dodecanol and 15.5 parts by mass of potassium hydroxide were added to a 2 L autoclave. After dehydration at 115 °C and 10.5 kPa, 720 parts by mass of ethylene oxide was added at 150 °C and a pressure of 0.3 MPa to carry out an addition reaction. After the reaction was completed, aging was carried out at the same reaction temperature for 6 hours, and then it was cooled to 80 °C. A total of 250 parts by mass of a synthetic adsorbent (Kyoward 600S, manufactured by Kyowa Chemical Industry Co., Ltd.) was added to the obtained reaction composition, and the mixture was treated at 4.0 kPa for 1 hour. Thereafter, the catalyst was removed by filtration to obtain Compound A1 shown in Table 5.

[0386] <Synthesis of Compounds A2 to A9, A11, and A13 to A16>

[0387] Except for changing the raw materials used in the synthesis example of Compound A1 as shown in Table 3, Compounds A2 to A9, A11, and A13 to A16 were obtained in the same manner as in the synthesis example of Compound A1. Compounds A2 to A9, A11, and A13 to A16 are shown in Table 5.

[0388] <Synthesis of Compound A10>

[0389] To a 1000 mL five-necked flask equipped with a reflux pipe, a dissolved oxygen concentration meter, and stirring blades, add a total of 100 parts by mass of Compound A1, 5 parts by mass of 5% Pt-1% Bi / C (Lot. TP-2 / 0230, manufactured by Evonik Co.) as a catalyst, and 420 parts by mass of ion-exchanged water. Then, while stirring at 400 rpm, heat up to 70 °C under a nitrogen stream. After reaching 70 °C, continue to flow nitrogen for 15 minutes. After that, switch the flow to oxygen and continue to flow oxygen at 90 mL / min for 18 hours to cause a reaction, obtaining Compound A10. Regarding Compound A10, refer to Table 5.

[0390] <Synthesis of Compound A12>

[0391] To a 1000 mL five-necked flask equipped with a reflux pipe, a dissolved oxygen concentration meter, and stirring blades, add a total of 100 parts by mass of Compound A11, 5 parts by mass of 5% Pt-1% Bi / C (Lot. TP-2 / 0230, manufactured by Evonik Co.) as a catalyst, and 420 parts by mass of ion-exchanged water. Then, while stirring at 400 rpm, heat up to 70 °C under a nitrogen stream. After reaching 70 °C, continue to flow nitrogen for 15 minutes. After that, switch the flow to oxygen and continue to flow oxygen at 90 mL / min for 18 hours to cause a reaction, obtaining Compound A12. Regarding Compound A12, refer to Table 5.

[0392] Table 5

[0393]

[0394] Among Compounds A2 to A16, A 1 and A 2 is ethylene.

[0395] <Preparation of Resin Particle Dispersion of Polyester Resin 1>

[0396] To a container, add a total of 50 parts by mass of the above-mentioned methyl ethyl ketone and 20 parts by mass of isopropyl alcohol. Then, gradually add 100 parts by mass of polyester resin 1 and stir to completely dissolve it, thereby obtaining a polyester resin 1 solution. Set the container containing the polyester resin 1 solution to 65 °C, and while stirring, gradually add 10% ammonia water dropwise to a total of 5 parts, and gradually add 230 parts of ion-exchanged water dropwise at a rate of 10 mL / min to cause phase inversion emulsification. Then use an evaporator to reduce the pressure to remove the solvent, obtaining a resin particle dispersion of polyester resin 1. Measure the particle size of the resin particle dispersion of polyester resin 1 using a particle size measuring device (LA-950, manufactured by Horiba, Ltd.). The volume average particle size of the resin particle dispersion of polyester resin 1 is 105 nm. Adjust the solid content in the resin particle dispersion of polyester resin 1 to 20% by mass with ion-exchanged water.

[0397] <Preparation of Resin Particle Dispersions of Polyester Resin 2 to Polyester Resin 9>

[0398] The resin particle dispersions of polyester resin 2 to polyester resin 9 were prepared in the same manner as the preparation of the resin particle dispersion of polyester resin 1, except that polyester resin 2 to 9 were used in place of polyester resin 1.

[0399] <Preparation of Colorant Particle Dispersion>

[0400] - 45 parts of copper phthalocyanine (Pigment Blue 15:3)

[0401] - 5 parts of an anionic surfactant Neogen RK (manufactured by DKS Co., Ltd.)

[0402] - 190 parts of ion-exchanged water

[0403] The above components were mixed and dispersed for 1 hour using a high-pressure impact disperser Nanomizer (manufactured by Yoshida Kikai Kogyo Co., Ltd.) to prepare an aqueous dispersion (colorant fine particle dispersion) having a colorant fine particle concentration of 20% by mass in which the colorant was dispersed.

[0404] <Preparation of Hydrocarbon Wax Particle Dispersion>

[0405] - 45 parts of hydrocarbon wax (HNP-9, manufactured by Nippon Seiro Co., Ltd.)

[0406] - 5 parts of an anionic surfactant Neogen RK (manufactured by DKS Co., Ltd.)

[0407] - 190 parts of ion-exchanged water

[0408] The above components were placed in a mixing vessel equipped with a stirrer, heated to 90 °C, and dispersed for 60 minutes by circulation using Clearmix WMotion (manufactured by M Technique Co., Ltd.). The dispersion conditions were as follows:

[0409] - Outer diameter of rotor: 3 cm

[0410] - Gap: 0.3 mm

[0411] - Rotor speed: 19,000 r / min

[0412] - Screen speed: 19,000 r / min

[0413] After dispersion treatment, cooling is carried out under the cooling conditions of a rotor speed of 1000 r / minute, a screen speed of 0 r / minute, and a cooling rate of 10 °C / minute to 40 °C, obtaining a hydrocarbon wax dispersion liquid with a volume average particle diameter of 160 nm and a solid component content of 20 mass%.

[0414] <Preparation of Ester Wax Dispersion Liquid 1>

[0415] - 45 parts of Ester Wax 1

[0416] - Ionic surfactant Neogen RK (manufactured by DKS Co., Ltd.) 5 parts

[0417] - Ion-exchanged water 190 parts

[0418] Put the above components into a mixing container equipped with a stirrer, heat to 90 °C, and carry out dispersion treatment for 60 minutes by means of circulation with Clearmix WMotion (manufactured by M Technique Co., Ltd.). The dispersion treatment conditions are as follows:

[0419] - Outer diameter of the rotor: 3 cm

[0420] - Gap: 0.3 mm

[0421] - Rotor speed: 19,000 r / minute

[0422] - Screen speed: 19,000 r / minute

[0423] After dispersion treatment, cooling is carried out under the cooling conditions of a rotor speed of 1000 r / minute, a screen speed of 0 r / minute, and a cooling rate of 10 °C / minute to 40 °C, obtaining Ester Wax Dispersion Liquid 1 with a volume average particle diameter of 170 nm and a solid component content of 20 mass%.

[0424] <Preparation of Ester Wax Dispersion Liquids 2 - 10>

[0425] Except for using Ester Waxes 2 - 10 instead of Ester Wax 1, Ester Wax Dispersion Liquids 2 - 10 are obtained in the same manner as the preparation of Ester Wax Dispersion Liquid 1.

[0426] <Production of Toner Particles 1>

[0427]

[0428] First, in the nucleation step, the above materials are placed in a round stainless-steel flask and mixed. Then, the mixture is dispersed at 5000 r / min for 10 minutes using a homogenizer Ultra Turrax T50 (manufactured by IKA Works, Inc.). After adding a 1.0% aqueous nitric acid solution and adjusting the pH to 3.0, the mixture is heated to 45 °C in a heating water bath while appropriately adjusting the rotation speed to stir the mixture using a stirring blade.

[0429] The volume-average particle diameter of the formed aggregated particles is appropriately confirmed using a Coulter Multisizer 3. When aggregated particles (nuclei) of 5.0 μm are formed, the following materials are added as the shell formation step, and stirring is continued for 1 hour to form a shell.

[0430]

[0431] (Borax: Sodium tetraborate decahydrate, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)

[0432] Then, as the spheroidization step, the pH is adjusted to 9.0 using a 5% aqueous sodium hydroxide solution, and the mixture is heated to 90 °C while continuing stirring.

[0433] Then, the average circularity of the formed aggregated particles is appropriately measured using a flow-type particle image analyzer “FPIA-3000” (manufactured by Sysmex Corporation).

[0434] Then, heating is carried out until the average circularity of the aggregated particles reaches 0.970 (the heating time is 3 hours). Then, as the cooling step, ice is rapidly added at a cooling rate of 10 °C / s or more, and thus cooled to 25 °C to obtain a dispersion of toner particles 1.

[0435] The dispersion of toner particles 1 is neutralized by adding hydrochloric acid to adjust the pH to 5.0 to 7.0, and then solid-liquid separation is carried out at a pressure of 0.3 MPa in a pressure filter to obtain a toner filter cake. It is repulped with ion-exchanged water to prepare a dispersion again, and then solid-liquid separation is carried out at a pressure of 0.3 MPa in the above filter to obtain a toner filter cake. In addition, 2000 parts by mass of ion-exchanged water is added to the toner filter cake, washing is carried out, and washing is carried out while removing water by repressurizing to 0.3 MPa again. In addition, after air-drying while maintaining 0.2 MPa, the toner filter cake is taken out and subjected to a pulverization treatment.

[0436] The pulverized toner cake was dried in a vacuum dryer at 40 °C for 12 hours and then classified to obtain toner particles 1. The production conditions and analysis results of toner particles 1 are shown in Tables 6 and 7.

[0437] <Production of toner particles 2 to 45 and comparative toner particles 1 to 11>

[0438] Except that the conditions were changed to those shown in Table 4, toner particles 2 to 45 and comparative toner particles 1 to 11 were obtained in the same manner as the production of toner particles 1. The production conditions and analysis results of toner particles 2 to 45 and comparative toner particles 1 to 11 are shown in Tables 6 and 7.

[0439] Table 6

[0440]

[0441] In the table, parts represent the mass parts of the dispersion and the aqueous solution, respectively. The numbers in the borax column represent the mass parts of a 2.0 mass% aqueous borax solution. SDBS represents sodium dodecylbenzenesulfonate.

[0442] Table 7

[0443]

[0444] In the table, the amount of dodecenyl succinic acid in the binder resin represents the content ratio of the monomer unit corresponding to dodecenyl succinic acid based on the mass of the binder resin. The content of the ester wax represents the mass parts relative to 100 mass parts of the binder resin. The content of compound A represents the extraction amount of compound A extracted from the toner with ethanol based on the mass of the toner. The content of boron atoms represents the content of boron atoms based on the mass of the toner particles.

[0445] [Example 1]

[0446] - 100.0 parts of toner particles 1

[0447] - RX10 (manufactured by Nippon Aerosil Co., Ltd.) 2.0 parts

[0448] - RX200 (manufactured by Nippon Aerosil Co., Ltd.) 1.5 parts

[0449] The above materials were mixed using a Henschel mixer FM10C (manufactured by Nippon Coke Co., Ltd.) at 3000 rpm for 7.5 minutes to obtain toner 1.

[0450] The obtained toner 1 was evaluated according to the following steps.

[0451] <Evaluation method>

[0452] [Evaluation of Low-temperature Fixing Property]

[0453] Leave the process cartridge filled with toner 1 at a temperature of 25°C and a humidity of 40% RH for 48 hours. Use a modified LBP-712Ci that can operate even when the fixing unit is removed, and output an unfixed image of an image pattern with 10 mm × 10 mm square images evenly arranged at 9 points on the overall transfer paper. The toner loading on the transfer paper is 0.80 mg / cm 2 , while changing the fixing temperature at 5°C intervals in the range of 100°C to 220°C, evaluate the lower fixing temperature and the upper fixing temperature. The transfer paper used is A4 paper (“Prover Bond Paper”: 105 g / m 2 , manufactured by Fox River Co.).

[0454] The fixing unit used is removed from the LBP-712Ci and modified into an external fixing unit that can even operate outside the laser beam printer. The fixing temperature of the external fixing unit is increased from 120°C in 5°C increments, and fixing is performed under the condition of a processing speed of 360 mm / second. Visually inspect the fixed image, and take the lowest temperature at which no cold offset occurs as the lower fixing temperature.

[0455] [Evaluation of Density Stability and Density Uniformity]

[0456] As an evaluation machine, a Color Laser Jet Enterprise 6701dn (manufactured by HP Inc.) was prepared and modified to change the printing speed. Using a process cartridge filled with toner 1, conduct a durability test of continuously passing (printing) 15,000 sheets of paper with a 1% image ratio horizontal lines in an environment of normal temperature and normal humidity NN (25°C / 50% RH) at a printing speed of 75 sheets per minute, and then evaluate the density stability and density uniformity.

[0457] To evaluate the density stability and density uniformity, after the durability test, output a solid black image on the first sheet, a horizontal line image on the second to 99th sheets, and a solid black image again on the 100th sheet. For the first and 100th solid black images, measure the image density at a total of 6 points on the lines 10 cm and 20 cm from the top of the transfer material and on the left, center, and right, and calculate the average value. Evaluate the density stability from the difference between the average density value of the first sheet and the average density value of the 100th sheet.

[0458] In addition, for the 100th solid black image, the image density uniformity was evaluated based on the difference in the average image density between the points 1 cm and 10 cm from the top of the transfer material. The transfer material used was GF-C081 (manufactured by Canon Inc., 81.4 g / m 2 ) and the density measurement was performed using X-Rite eXact Advance (manufactured by X-Rite Inc.).

[0459] The evaluation criteria are as follows:

[0460] - Evaluation criteria for density stability

[0461] (Evaluation criteria)

[0462] A: The average density difference between the 1st and 100th sheets is less than 0.04

[0463] B: The average density difference between the 1st and 100th sheets is 0.04 or more and less than 0.07

[0464] C: The average density difference between the 1st and 100th sheets is 0.07 or more and less than 0.10

[0465] D: The average density difference between the 1st and 100th sheets is 0.10 or more

[0466] - Evaluation criteria for density uniformity

[0467] (Evaluation criteria)

[0468] A: The average image density difference between the points 1 cm and 10 cm from the top of the transfer material is less than 0.04

[0469] B: The average image density difference between the points 1 cm and 10 cm from the top of the transfer material is 0.04 or more and less than 0.07

[0470] C: The average image density difference between the points 1 cm and 10 cm from the top of the transfer material is 0.07 or more and less than 0.10

[0471] D: The average image density difference between the points 1 cm and 10 cm from the top of the transfer material is 0.10 or more

[0472] As a result of the evaluation of Toner 1, the density of the solid black images on the 1st and 100th sheets was 1.40 or more, and the average density difference was less than 0.04, indicating stability. In addition, for the solid black image on the 100th sheet, the average image density difference between the points 1 cm and 10 cm from the top edge of the transfer material was less than 0.04, indicating excellent density uniformity. The evaluation results of Toner 1 are shown in Table 8.

[0473] Table 8

[0474]

[0475] [Examples 2 to 45 and Comparative Examples 1 to 11]

[0476] Table 8 shows the evaluation results of Examples 2 to 45 and Comparative Examples 1 to 11 obtained in the same manner as in Example 1.

[0477] Although the present invention has been described with reference to exemplary embodiments, it should be understood that the present invention is not limited to the disclosed exemplary embodiments. The scope of the appended claims should be accorded the broadest interpretation so as to cover all such modifications as well as equivalent structures and functions.

Claims

1. A toner comprising toner particles containing a binder resin, wherein: The toner particles contain an ester wax and a compound A, wherein the compound A is at least one compound selected from the group consisting of a compound represented by the following formula (1) and a compound represented by the following formula (2), The binder resin comprises a polyester resin, The polyester resin comprises a monomer unit corresponding to dodecenylsuccinic acid, and The SP value (cal / cm 3 ) 0.5 8.70 to 9.00, R 1 -O-(A 1 -O) n -X (1) In formula (1), R 1 represents an alkyl group having 8 to 24 carbon atoms, A 1 represents ethylene or propylene, n is an integer of 5 to 60, and X is H, CH2COOH, CH2SO3H, CH2COONa, or CH2SO3Na; R 2 -Ph-O-(A 2 -O) m -X (2) In formula (2), R 2 represents an alkyl group having 8 to 24 carbon atoms, Ph represents a phenylene group, A 2 represents an ethylene group or a propylene group, m is an integer of 5 to 60, and X is H, CH2COOH, CH2SO3H, CH2COONa, or CH2SO3Na. 2 . The toner according to claim 1 , wherein the ester wax has a molecular weight of 500 to 1,000.

3. The toner according to claim 1 or 2, wherein The content of the ester wax in the toner is 3.0 parts by mass to 20.0 parts by mass relative to 100 parts by mass of the binder resin.

4. The toner according to claim 1 or 2, wherein The content ratio of the monomer unit corresponding to dodecenylsuccinic acid is 3.0% by mass to 20.0% by mass based on the mass of the binder resin. 5 . The toner according to claim 1 , wherein an extraction amount of the compound A extracted from the toner with ethanol is 10 ppm to 1000 ppm based on the mass of the toner.

6. The toner according to claim 1 or 2, wherein The content of the ester wax in the toner is 3.0 parts by mass to 20.0 parts by mass relative to 100 parts by mass of the binder resin, The content ratio of the monomer unit corresponding to dodecenylsuccinic acid is 3.0% by mass to 20.0% by mass based on the mass of the binder resin, and The extraction amount of the compound A extracted from the toner with ethanol is 10 ppm to 1000 ppm based on the mass of the toner.

7. The toner according to claim 1 or 2, wherein the ester wax comprises a compound represented by the following formula (3), R 3 -COO-R 5 -OCO-R 4 (3) R 3 and R 4 each independently represents an alkyl group having 17 to 22 carbon atoms, and R 5 It represents an alkylene group having 2 to 6 carbon atoms.

8. The toner according to claim 1 or 2, wherein In cross-sectional observation of the toner using a transmission electron microscope, When the average ratio of the area occupied by the domains of the wax containing the ester wax in the surface layer region from the surface of the toner particle to a depth of 200 nm is defined as As, As is 0.0 area % to 1.0 area %. 9 . The toner according to claim 1 , wherein the toner particles contain boron atoms, and a content of the boron atoms is 1.0 ppm to 50.0 ppm based on the mass of the toner particles. 10 . The toner according to claim 1 , wherein a content ratio of the polyester resin is 50.0% by mass to 100.0% by mass based on the mass of the binder resin.

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