Toner for electrostatic image development

Abstract

Provided are: a toner for electrostatic image development which comprises a binder resin and a colorant comprising the binder resin that includes an amorphous polyester resin A that is a product of polycondensation of poly(ethylene terephthalate), an alcohol ingredient, and a carboxylic acid ingredient, and the colorant that includes an organic yellow pigment that has an NH group amount of 4.0 to 15.0 mmol / g inclusive, the NH group amount being a value obtained by dividing the total number of -NH- groups and -NH2 groups in one molecule by the molecular weight; and a method for producing the toner for electrostatic image development. The toner for electrostatic image development according to the present invention is suitable for use in, for example, developing latent images formed in electrophotography, electrostatic recording, electrostatic printing, or the like.

Description

Toner for developing electrostatic images

[0001] The present invention relates to a toner for developing electrostatic images used in developing latent images formed in electrophotography, electrostatic recording, electrostatic printing, etc., and a method for producing the same.

[0002] In recent years, C.I. Pigment Yellow 74 has been widely known as a yellow pigment used in toners for developing electrostatic images, but from the viewpoints of weather resistance and safety, switching to other yellow pigments has been considered.

[0003] For example, Patent Document 1 proposes a yellow pigment having three or more aromatic rings in one molecule and a molecular weight of 600 or more and 1,500 or less.

[0004] Japanese Patent Application Laid-Open No. 2020-154154

[0005] The present invention provides: [1] a toner for developing electrostatic images, comprising a binder resin and a colorant, wherein the binder resin comprises an amorphous polyester resin A which is a polycondensate of polyethylene terephthalate, an alcohol component, and a carboxylic acid component, and the colorant comprises an -NH- group and an -NH- group in one molecule. ２ [2] a toner for developing electrostatic images, comprising an organic yellow pigment having an NH group amount of 4.0 mmol / g or more and 15.0 mmol / g or less, where the NH group amount is the total number of groups divided by the molecular weight; and [3] a method for producing the toner for developing electrostatic images according to [1], comprising a step of melting and kneading at least the binder resin and the colorant, and a step of pulverizing the obtained kneaded mixture. Detailed Description of the Invention

[0006] Toners containing organic yellow pigments have the problem that the smear resistance of printed images is insufficient.

[0007] The present invention relates to a toner for developing electrostatic images, which has excellent smear resistance, and a method for producing the same.

[0008] The toner for developing electrostatic images of the present invention exhibits excellent effects in terms of smear resistance.

[0009] The electrostatic image developing toner of the present invention (hereinafter also simply referred to as "toner") has a significant feature in that it is a combination of an amorphous polyester resin (amorphous polyester resin A) using polyethylene terephthalate (PET) and an organic yellow pigment having a large amount of NH groups. The reason why the electrostatic image developing toner of the present invention has excellent smear resistance is not clear, but is presumed to be as follows.

[0010] In the amorphous polyester resin A obtained using PET, the PET undergoes depolymerization during the polycondensation reaction of the alcohol component, the carboxylic acid component, and the PET, and is incorporated into the polyester resin chain through a transesterification reaction. However, the PET is not completely randomized, and units that can be called PET segments exist in the resulting resin. These PET segments have a high concentration of ester groups and tend to interact with organic yellow pigments that have a high amount of NH groups. Therefore, during fixation, the amorphous polyester resin A forms a pseudo-crosslinked structure via the organic yellow pigment, which is thought to improve the impact resistance of printed materials and provide excellent smear resistance.

[0011] The amorphous polyester resin A is a polycondensation product of PET, an alcohol component, and a carboxylic acid component.

[0012] PET is produced by a polycondensation reaction between an alcohol component and a carboxylic acid component, and / or by depolymerization of a portion of PET. Ethylene glycol and terephthalic acid are then used as raw material monomers in the polycondensation reaction and incorporated into a polyester resin. PET is an equimolar polycondensation product of ethylene glycol and terephthalic acid, and the amounts of the alcohol component and carboxylic acid component described below include the amounts of ethylene glycol and terephthalic acid that constitute PET.

[0013] The PET may be new virgin PET or recycled PET. Recycled PET is obtained by collecting used PET, washing it as necessary, separating it from other materials, and then pulverizing it, decomposing the pulverized material into monomer units, and using these as raw materials for resynthesis.

[0014] In the present invention, the PET preferably has a relatively low IV value, i.e., a low molecular weight, compared to conventionally used PET. By introducing a PET with a low IV value (low molecular weight) into the polyester resin, depolymerization of the PET proceeds more uniformly.

[0015] From the above viewpoints, the IV value of PET is preferably 0.40 or more, more preferably 0.45 or more, even more preferably 0.50 or more, and even more preferably 0.55 or more. From the viewpoints of low-temperature fixability and uniform depolymerization, it is preferably 0.85 or less, more preferably 0.80 or less, even more preferably 0.75 or less, even more preferably 0.70 or less, and even more preferably 0.65 or less. The IV value is an intrinsic viscosity and serves as an index of molecular weight. The IV value of PET can be adjusted by the polycondensation time, etc.

[0016] Commercially available PET products having an IV value of 0.40 to 0.85 include RAMAPET L1 (manufactured by Indorama Ventures, IV value: 0.60), RAMAPET BF3067 (manufactured by Indorama Ventures, IV value: 0.65), RAMAPET N2G (manufactured by Indorama Ventures, IV value: 0.75), TRN-NTJ (manufactured by Teijin Limited, IV value: 0.53), TRN-RTJC (manufactured by Teijin Limited, IV value: 0.64), RAMAPET S1 (manufactured by Indorama Ventures, IV value: 0.84), and UK-31 (manufactured by Utsumi Recycle Systems Co., Ltd., IV value: 0.67).

[0017] The content of the low IV PET is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and still more preferably 100% by mass, of the total amount of PET used in polycondensation.

[0018] The PET content in amorphous polyester resin A is, from the viewpoint of smearing, preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, and preferably 75 mol% or less, more preferably 70 mol% or less, even more preferably 65 mol% or less, even more preferably 50 mol% or less, even more preferably 40 mol% or less, and even more preferably 30 mol% or less, based on the total amount of the alcohol component, carboxylic acid component, and PET. When amorphous polyester resin A is composed of two or more resins, the weighted average of the PET contents of each resin is taken as the PET content of amorphous polyester resin A. Note that, since PET is a polycondensation product of ethylene glycol with terephthalic acid, dimethyl terephthalate, etc., it is calculated by counting terephthalic acid-ethylene glycol units (MW: 192) as 1 mole. Therefore, the number of moles of PET = the number of moles of ethylene glycol units = the number of moles of terephthalic acid units.

[0019] From the viewpoint of smearing, the alcohol component preferably contains an alkylene oxide adduct of bisphenol A.

[0020] Examples of alkylene oxide adducts of bisphenol A include those represented by the formula (I):

[0021]

[0022] (wherein OR and RO are oxyalkylene groups, R is an ethylene group and / or propylene group, x and y are the average number of moles of alkylene oxide added and are each a positive number, and the sum of x and y is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, more preferably 6 or less, and even more preferably 4 or less) is preferred.

[0023] From the viewpoint of low-temperature fixability, the content of the alkylene oxide adduct of bisphenol A in the alcohol component is preferably 25 mol % or more, more preferably 40 mol % or more, even more preferably 55 mol % or more, and preferably 95 mol % or less, more preferably 90 mol % or less, even more preferably 85 mol % or less. The alcohol component here includes the ethylene glycol units in PET.

[0024] Examples of other alcohol components include aliphatic diols, alicyclic diols, bisphenol A, and the like.

[0025] The aliphatic diol is preferably an aliphatic diol other than ethylene glycol, and examples thereof include 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, neopentyl glycol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

[0026] Examples of the alicyclic diol include hydrogenated bisphenol A.

[0027] Examples of the carboxylic acid component include aromatic dicarboxylic acid compounds and aliphatic dicarboxylic acid compounds.

[0028] Examples of aromatic dicarboxylic acid compounds include phthalic acid, isophthalic acid, terephthalic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0029] Examples of the aliphatic dicarboxylic acid compound include fumaric acid, maleic acid, succinic acid, succinic acid derivatives substituted with a hydrocarbon group, glutaric acid, adipic acid, sebacic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0030] For the alcohol component and / or carboxylic acid component of the amorphous polyester resin A, a trivalent or higher raw material monomer may be used from the viewpoint of adjusting the softening point.

[0031] Examples of the trihydric or higher alcohol include sorbitol, pentaerythritol, glycerin, and trimethylolpropane.

[0032] Examples of the trivalent or higher carboxylic acid compound include trimellitic acid, pyromellitic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0033] The content of the trivalent or higher raw material monomer is preferably 2 mol% or more, more preferably 4 mol% or more, of the total amount of the alcohol component, the carboxylic acid component, and the PET, and is preferably 25 mol% or less, more preferably 20 mol% or less.

[0034] The alcohol component may contain a monohydric alcohol, and the carboxylic acid component may contain a monocarboxylic acid compound, as appropriate.

[0035] In this specification, macromonomers and hydroxycarboxylic acids are not included in the alcohol component and carboxylic acid component.

[0036] The equivalent ratio (COOH groups / OH groups) of the carboxylic acid component (including terephthalic acid units in PET) to the alcohol component (including ethylene glycol units in PET) is preferably 0.6 or more, more preferably 0.7 or more, even more preferably 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0037] The amorphous polyester resin A can be produced, for example, by polycondensing an alcohol component, a carboxylic acid component, and PET in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and if necessary, in the presence of a co-catalyst, a polymerization inhibitor, etc., at a temperature of preferably 130°C or higher, more preferably 170°C or higher, and preferably 250°C or lower, more preferably 240°C or lower.

[0038] Examples of esterification catalysts include tin compounds such as dibutyltin oxide and tin(II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropoxybis(triethanolaminate) and titanium dihydroxybis(triethanolaminate). The amount of the esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 1.5 parts by mass or less, and more preferably 1 part by mass or less, per 100 parts by mass of the total of the alcohol component, the carboxylic acid component, and the PET. Examples of promoters for the esterification catalyst include gallic acid. The amount of the promoter used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.5 parts by mass or less, and more preferably 0.1 parts by mass or less, per 100 parts by mass of the total of the alcohol component, the carboxylic acid component, and the PET. Examples of polymerization inhibitors include tert-butylcatechol. The amount of the polymerization inhibitor used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and preferably 0.5 part by mass or less, more preferably 0.1 part by mass or less, relative to 100 parts by mass of the total amount of the alcohol component, the carboxylic acid component, and the PET.

[0039] In the present invention, the polyester resin may be modified to such an extent that its properties are not substantially impaired. Examples of modified polyester resins include polyester resins grafted or blocked with phenol, urethane, epoxy, or the like, by methods described in JP-A Nos. 11-133668, 10-239903, and 8-20636. Among the modified polyester resins, urethane-modified polyester resins in which polyester resins are urethane-extended with a polyisocyanate compound are preferred.

[0040] The ester group concentration of the amorphous polyester resin A is preferably 3.5 mmol / g or more, more preferably 3.7 mmol / g or more, and even more preferably 4.0 mmol / g or more, and is preferably 12.0 mmol / g or less, more preferably 10.0 mmol / g or less, and even more preferably 6.0 mmol / g or less. When two or more types of amorphous polyester resins A are used, the weighted average of the ester group concentrations of the respective amorphous polyester resins A is taken as the ester group concentration of the amorphous polyester resin A.

[0041] In the present invention, the ester group concentration of the polyester resin is calculated by the following formula.

[0042]

[0043] (In the formula, A is the total amount (mol) of ester bonds produced when all the raw material monomers of the polyester resin are reacted, and B is the total mass (g) of the raw material monomers constituting the polyester resin. The numbers in parentheses in the formula indicate the units of each value.)

[0044] The softening point of the amorphous polyester resin A is preferably 70°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher from the viewpoint of charging stability, and is preferably 170°C or lower, more preferably 160°C or lower, and even more preferably 150°C or lower from the viewpoint of low-temperature fixability.

[0045] The crystallinity of a resin is expressed by the crystallinity index, defined as the ratio of the softening point to the maximum endothermic peak temperature measured by a differential scanning calorimeter, i.e., the value [softening point / maximum endothermic peak temperature]. Amorphous resins are those in which no endothermic peak is observed, or, if observed, have a crystallinity index greater than 1.4 or less than 0.6. On the other hand, crystalline resins are those in which the crystallinity index is 0.6 or greater and 1.4 or less. The crystallinity of a resin can be adjusted by the type and ratio of raw material monomers, as well as production conditions (e.g., reaction temperature, reaction time, cooling rate), etc. The maximum endothermic peak temperature refers to the temperature of the peak with the largest peak area among the observed endothermic peaks. For crystalline resins, the maximum endothermic peak temperature is the melting point.

[0046] From the viewpoint of low-temperature fixability and fixing width, the amorphous polyester resin A may be composed of resins having different softening points. The difference in softening point between the two resins is preferably 10° C. or more, more preferably 20° C. or more, and is preferably 60° C. or less, more preferably 40° C. or less.

[0047] The softening point of the amorphous resin having a higher softening point (resin AH) is preferably 100°C or higher, more preferably 110°C or higher, and even more preferably 120°C or higher, from the viewpoint of fixing width, and is preferably 170°C or lower, more preferably 160°C or lower, and even more preferably 150°C or lower, from the viewpoint of low-temperature fixability.

[0048] Furthermore, the softening point of the amorphous resin having a lower softening point (resin AL) is preferably 70°C or higher, more preferably 90°C or higher, and even more preferably 100°C or higher, from the viewpoint of charging stability, and is preferably 130°C or lower, more preferably 125°C or lower, even more preferably 120°C or lower, and even more preferably 110°C or lower, from the viewpoint of low-temperature fixability.

[0049] The mass ratio of resin AH to resin AL (resin AH / resin AL) is preferably 10 / 90 or more, more preferably 20 / 80 or more, even more preferably 30 / 70 or more, and is preferably 90 / 10 or less, more preferably 80 / 20 or less, even more preferably 75 / 25 or less.

[0050] The glass transition temperature of the amorphous polyester resin A is preferably 40°C or higher, more preferably 50°C or higher, from the viewpoint of storage stability, and is preferably 80°C or lower, more preferably 70°C or lower, from the viewpoint of low-temperature fixability.

[0051] The acid value of the amorphous polyester resin A is preferably 1 mgKOH / g or more, more preferably 3 mgKOH / g or more, from the viewpoint of charging stability, and is preferably 20 mgKOH / g or less, more preferably 18 mgKOH / g or less, from the viewpoint of durability.

[0052] The content of the amorphous polyester resin A in the binder resin is preferably 70% by mass or more, more preferably 75% by mass or more, and even more preferably 80% by mass or more, from the viewpoint of durability, and is preferably 100% by mass or less, more preferably 99% by mass or less, even more preferably 97% by mass or less, and even more preferably 95% by mass or less, from the viewpoint of low-temperature fixability.

[0053] The binder resin preferably further contains a crystalline polyester resin C from the viewpoint of low-temperature fixability.

[0054] The crystalline polyester resin C is preferably a polycondensate of an alcohol component containing an aliphatic diol and a carboxylic acid component containing an aliphatic dicarboxylic acid compound.

[0055] Examples of aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-butenediol, 1,7-heptanediol, 1,8-octanediol, neopentyl glycol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

[0056] The aliphatic diol has 2 or more carbon atoms, preferably 6 or more carbon atoms, and from the viewpoint of adjusting the ester group concentration, preferably 14 or less carbon atoms, more preferably 12 or less carbon atoms.

[0057] From the viewpoint of improving the low-temperature fixability of the toner, the aliphatic diol preferably has a hydroxyl group at the end of the carbon chain, and is more preferably an α,ω-straight-chain alkanediol.

[0058] The content of the aliphatic diol in the alcohol component is preferably 80 mol % or more, more preferably 90 mol % or more, and even more preferably 95 mol % or more, but 100 mol % or less.

[0059] Examples of alcohol components other than aliphatic diols include alkylene oxide adducts of bisphenol A, aromatic diols such as bisphenol A, hydrogenated bisphenol A, trivalent or higher alcohols such as sorbitol, pentaerythritol, glycerin, and trimethylolpropane.

[0060] Examples of the aliphatic dicarboxylic acid compound include succinic acid (number of carbon atoms: 4), fumaric acid (number of carbon atoms: 4), adipic acid (number of carbon atoms: 6), suberic acid (number of carbon atoms: 8), azelaic acid (number of carbon atoms: 9), sebacic acid (number of carbon atoms: 10), dodecanedioic acid (number of carbon atoms: 12), tetradecanedioic acid (number of carbon atoms: 14), anhydrides of these acids, and alkyl esters of these acids having from 1 to 3 carbon atoms. Here, when the aliphatic dicarboxylic acid compound is an alkyl ester, the number of carbon atoms of the alkyl group is not included in the above carbon number.

[0061] The carbon number of the aliphatic dicarboxylic acid compound is preferably 4 or more, more preferably 6 or more, and even more preferably 8 or more, and from the viewpoint of adjusting the ester group concentration, it is preferably 14 or less, more preferably 12 or less.

[0062] From the viewpoint of hydrophobicity, the content of the aliphatic dicarboxylic acid compound in the carboxylic acid component is preferably 50 mol% or more, more preferably 60 mol% or more, even more preferably 70 mol% or more, and still more preferably 80 mol% or more, and is 100 mol% or less.

[0063] Examples of other carboxylic acid components include aromatic dicarboxylic acid compounds such as phthalic acid, isophthalic acid, and terephthalic acid, and trivalent or higher carboxylic acid compounds such as trimellitic acid and pyromellitic acid.

[0064] The alcohol component may contain a monohydric alcohol, and the carboxylic acid component may contain a monocarboxylic acid compound, as appropriate.

[0065] The equivalent ratio of the carboxyl group of the carboxylic acid component to the hydroxyl group of the alcohol component (COOH group / OH group) is preferably 0.8 or more, more preferably 0.9 or more, from the viewpoint of charging stability, and is preferably 1.2 or less, more preferably 1.1 or less, from the viewpoint of low-temperature fixability.

[0066] The polycondensation reaction conditions of the alcohol component and the carboxylic acid component of the crystalline polyester resin C are the same as those of the amorphous polyester resin A, except that the preferred reaction temperature is 120°C or higher, more preferably 180°C or higher, and 230°C or lower, more preferably 220°C or lower.

[0067] The softening point of the crystalline polyester resin C is preferably 50°C or higher, more preferably 65°C or higher, and even more preferably 70°C or higher from the viewpoint of durability, and is preferably 140°C or lower, more preferably 120°C or lower, and even more preferably 100°C or lower from the viewpoint of low-temperature fixability.

[0068] The melting point of the crystalline polyester resin C is preferably 50°C or higher, more preferably 65°C or higher, and even more preferably 70°C or higher from the viewpoint of durability, and is preferably 130°C or lower, more preferably 120°C or lower, and even more preferably 100°C or lower from the viewpoint of low-temperature fixability.

[0069] The acid value of the crystalline polyester resin C is preferably 1 mgKOH / g or more, more preferably 3 mgKOH / g or more, from the viewpoint of low-temperature fixability, and is preferably 30 mgKOH / g or less, more preferably 25 mgKOH / g or less, from the viewpoint of durability.

[0070] The content of the crystalline polyester resin C in the binder resin is preferably 1% by mass or more, more preferably 3% by mass or more, and even more preferably 5% by mass or more, from the viewpoint of low-temperature fixability, and is preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, from the viewpoint of durability.

[0071] From the viewpoint of charging stability, the mass ratio of crystalline polyester resin C to amorphous polyester resin A (crystalline polyester resin C / amorphous polyester resin A) is preferably 1 / 99 or more, more preferably 3 / 97 or more, even more preferably 5 / 95 or more, and is preferably 30 / 70 or less, more preferably 25 / 75 or less, even more preferably 20 / 80 or less.

[0072] Other binder resins include vinyl resins such as styrene-acrylic resin, epoxy resin, polycarbonate, polyurethane, and composite resins containing two or more of these resins.

[0073] The total content of the amorphous polyester resin A and the crystalline polyester resin C in the binder resin is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 90% by mass or more, even more preferably 95% by mass or more, and still more preferably 100% by mass.

[0074] The content of the binder resin in the toner is preferably 60% by mass or more, more preferably 70% by mass or more, and even more preferably 80% by mass or more, and is preferably less than 100% by mass, more preferably 98% by mass or less, and even more preferably 95% by mass or less.

[0075] The colorant contains an organic yellow pigment having a specific amount of NH groups in view of the interaction with the amorphous polyester resin A.

[0076] The amount of NH groups in the organic yellow pigment is 4.0 mmol / g or more, preferably 5.0 mmol / g or more, more preferably 6.0 mmol / g or more, and 15.0 mmol / g or less, preferably 12.5 mmol / g or less, more preferably 10.0 mmol / g or less. Here, the amount of NH groups refers to the number of -NH- groups and -NH ２ It is the total number of groups divided by the molecular weight.

[0077] As the organic yellow pigment, from the viewpoint of achieving a desired NH group amount, at least one selected from the group consisting of benzimidazolone pigments, isoindoline pigments, and condensed disazo pigments is preferred.

[0078] Examples of benzimidazolone pigments include C.I. Pigment Yellow 180 (having -NH- and -NH- groups in one molecule). ２ total number of groups=6, molecular weight=733, NH group amount=8.2 mmol / g).

[0079] Examples of isoindoline pigments include C.I. Pigment Yellow 185 (containing -NH- and -NH- groups in one molecule). ２ total number of groups=4, molecular weight=337, NH group amount=11.9 mmol / g).

[0080] Condensed disazo pigments include C.I. Pigment Yellow 93 (containing -NH- and -NH- groups in one molecule). ２ Total number of groups = 4, molecular weight = 937, NH group amount = 4.3 mmol / g), C.I. Pigment Yellow 95 (-NH- group and -NH- group in one molecule) ２ total number of groups=4, molecular weight=917, NH group amount=4.4 mmol / g).

[0081] From the viewpoint of toner smear resistance, the organic yellow pigment used in the present invention is preferably at least one selected from benzimidazolone pigments and isoindoline pigments, and more preferably at least one selected from C.I. Pigment Yellow 180 (PY180) and C.I. Pigment Yellow 185 (PY185).

[0082] The content of the organic yellow pigment is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 3 parts by mass or more, relative to 100 parts by mass of the amorphous polyester resin A, and is preferably 20 parts by mass or less, more preferably 18 parts by mass or less, and even more preferably 15 parts by mass or less.

[0083] The colorant may contain other colorants as long as the effects of the present invention are not impaired, but the content of the organic yellow pigment in the colorant is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and still more preferably 100% by mass. Examples of other colorants include carbon black, phthalocyanine blue, permanent brown FG, brilliant fast scarlet, pigment green B, rhodamine B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, and disazo yellow.

[0084] The content of the colorant is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 3 parts by mass or more, relative to 100 parts by mass of the binder resin, and is preferably 20 parts by mass or less, more preferably 18 parts by mass or less, and even more preferably 15 parts by mass or less.

[0085] The toner for developing electrostatic images of the present invention may contain additives such as a release agent, a charge control agent, a magnetic powder, a flowability improver, a conductivity adjuster, a reinforcing filler such as a fibrous substance, an antioxidant, and a cleaning property improver, in addition to the binder resin and the colorant.

[0086] Examples of the release agent include hydrocarbon waxes such as polypropylene wax, polyethylene wax, ethylene-propylene copolymer wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax, and oxides thereof; ester waxes such as carnauba wax, montan wax, and deacidified waxes thereof, and fatty acid ester wax; fatty acid amides, fatty acids, higher alcohols, and fatty acid metal salts, and these may be used alone or in combination of two or more.

[0087] The melting point of the release agent is preferably 60°C or higher, more preferably 70°C or higher, from the viewpoint of toner transferability, and is preferably 160°C or lower, more preferably 140°C or lower, even more preferably 120°C or lower, and even more preferably 110°C or lower, from the viewpoint of low-temperature fixability.

[0088] The content of the release agent is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 1.5 parts by mass or more, relative to 100 parts by mass of the binder resin, from the viewpoints of the low-temperature fixability and offset resistance of the toner and the dispersibility in the binder resin, and is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 7 parts by mass or less.

[0089] The charge control agent is not particularly limited, and may contain either a positively chargeable charge control agent or a negatively chargeable charge control agent.

[0090] Examples of positively chargeable charge control agents include nigrosine dyes such as "Nigrosine Base EX," "Oil Black BS," "Oil Black SO," "Bontron N-01," "Bontron N-04," "Bontron N-07," "Bontron N-09," and "Bontron N-11" (all manufactured by Orient Chemical Industries Co., Ltd.); triphenylmethane dyes containing a tertiary amine as a side chain; quaternary ammonium salt compounds such as "Bontron P-51" (manufactured by Orient Chemical Industries Co., Ltd.), cetyltrimethylammonium bromide, and "COPY CHARGE PX" (manufactured by Orient Chemical Industries Co., Ltd.). VP435 (manufactured by Clariant), etc.; polyamine resins, for example, "AFP-B" (manufactured by Orient Chemical Industries, Ltd.), etc.; imidazole derivatives, for example, "PLZ-2001" and "PLZ-8001" (both manufactured by Shikoku Chemical Industries, Ltd.), etc.; styrene-acrylic resins, for example, "FCA-701PT" and "FCA-201-PS" (manufactured by Fujikura Chemical Industries, Ltd.), etc.

[0091] Examples of negatively chargeable charge control agents include metal-containing azo dyes, such as "Barifast Black 3804," "Bontron S-31," "Bontron S-32," "Bontron S-34," and "Bontron S-36" (all manufactured by Orient Chemical Industries, Ltd.), "Eizenspiron Black TRH," and "T-77" (manufactured by Hodogaya Chemical Co., Ltd.); metal compounds of benzilic acid compounds, such as "LR-147" and "LR-297" (manufactured by Nippon Carlit Co., Ltd.); metal compounds of salicylic acid compounds, such as "Bontron E-81," "Bontron E-84," "Bontron E-88," and "Bontron E-304" (all manufactured by Orient Chemical Industries, Ltd.), and "TN-105" (manufactured by Hodogaya Chemical Co., Ltd.); copper phthalocyanine dyes; and quaternary ammonium salts, such as "COPY CHARGE NX" VP434 (manufactured by Clariant), nitroimidazole derivatives, etc.; organometallic compounds, etc.

[0092] From the viewpoint of the charging stability of the toner, the content of the charge control agent is preferably 0.01 parts by mass or more, more preferably 0.2 parts by mass or more, and is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, and even more preferably 2 parts by mass or less, relative to 100 parts by mass of the binder resin.

[0093] The toner may be a toner obtained by any conventionally known method such as a melt-kneading method, an emulsion aggregation method, or a suspension polymerization method, and may also be a toner having a core-shell structure, but from the viewpoint of smearing, a pulverized toner obtained by a melt-kneading method is preferred. In the case of a pulverized toner obtained by a melt-kneading method, it is preferably produced by a method including a step of melt-kneading at least a binder resin and a colorant and a step of pulverizing the resulting kneaded mixture. For example, the toner can be produced by uniformly mixing raw materials such as an amorphous polyester resin A and a colorant, and, if necessary, a crystalline polyester resin, a release agent, and a charge control agent, in a mixer such as a Henschel mixer, followed by melt-kneading in an internal kneader, a single-screw or twin-screw extruder, an open-roll kneader, or the like, followed by cooling, pulverization, and classification.

[0094] In order to improve the transferability of the toner of the present invention, it is preferable to use an external additive. Examples of the external additive include inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide, and zinc oxide, and organic fine particles such as melamine-based resin fine particles and polytetrafluoroethylene resin fine particles, and two or more of these may be used in combination. Among these, silica is preferred, and from the viewpoint of the transferability of the toner, hydrophobic silica that has been subjected to a hydrophobic treatment is more preferred.

[0095] Examples of hydrophobic treatment agents for hydrophobizing the surfaces of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), cyclic silazanes, silicone oils, aminosilanes, octyltriethoxysilane (OTES), and methyltriethoxysilane.

[0096] From the viewpoint of the chargeability, fluidity, and transferability of the toner, the average particle size of the external additive is preferably 5 nm or more, more preferably 10 nm or more, and even more preferably 15 nm or more, and is preferably 250 nm or less, more preferably 200 nm or less, and even more preferably 90 nm or less.

[0097] The external addition treatment by mixing the toner particles with the external additives can be carried out in accordance with a conventional method, and a mixer such as a Henschel mixer can be used.

[0098] From the viewpoint of the chargeability, fluidity, and transferability of the toner, the content of the external additive is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.3 parts by mass or more, relative to 100 parts by mass of the toner particles before treatment with the external additive, and is preferably 5 parts by mass or less, and more preferably 3 parts by mass or less.

[0099] The volume median particle size (D ５０ ) is preferably 3 μm or more, more preferably 4 μm or more, and is preferably 15 μm or less, more preferably 10 μm or less. ５０) means a particle size at which the cumulative volume frequency calculated by volume fraction is 50% counted from the smallest particle size. In addition, when the toner is treated with an external additive, the volume median particle size of the toner particles before treatment with the external additive is taken as the volume median particle size of the toner.

[0100] The toner of the present invention can be used as a toner for one-component development as it is, or as a toner for two-component development mixed with a carrier, in an image forming apparatus of a one-component development system or a two-component development system, respectively.

[0101] In relation to the above-described embodiment, the present invention further discloses the following toner for developing electrostatic images and a method for producing the same.

[0102] <1> A toner for developing electrostatic images, comprising a binder resin and a colorant, wherein the binder resin comprises an amorphous polyester resin A which is a polycondensation product of polyethylene terephthalate, an alcohol component, and a carboxylic acid component, and the colorant comprises an —NH— group and an —NH— group in one molecule. ２ The toner for developing electrostatic images contains an organic yellow pigment having an NH group amount of 4.0 mmol / g or more and 15.0 mmol / g or less, where the NH group amount is the total number of groups divided by the molecular weight.

[0103] <2> The toner for developing electrostatic images according to the above item <1>, wherein the polyethylene terephthalate has a low IV value of 0.40 or more, preferably 0.45 or more, more preferably 0.50 or more, even more preferably 0.55 or more, and 0.85 or less, preferably 0.80 or less, more preferably 0.75 or less, even more preferably 0.70 or less, and even more preferably 0.65 or less. <3> The toner for developing electrostatic images according to the above item <2>, wherein the content of the low IV polyethylene terephthalate is 90% by mass or more, preferably 95% by mass or more, more preferably 98% by mass or more, and even more preferably 100% by mass, of the total amount of polyethylene terephthalate to be subjected to polycondensation. <4> The electrostatic image developing toner according to any one of <1> to <3>, wherein the content of polyethylene terephthalate is 5 mol% or more, preferably 10 mol% or more, more preferably 20 mol% or more, and 75 mol% or less, preferably 70 mol% or less, more preferably 65 mol% or less, even more preferably 50 mol% or less, even more preferably 40 mol% or less, and even more preferably 30 mol% or less, based on the total amount of the alcohol component, the carboxylic acid component, and the polyethylene terephthalate. <5> The electrostatic image developing toner according to any one of <1> to <4>, wherein the alcohol component contains an alkylene oxide adduct of bisphenol A represented by formula (I). <6> The electrostatic image developing toner according to <5>, wherein the content of the alkylene oxide adduct of bisphenol A is 25 mol% or more, preferably 40 mol% or more, more preferably 55 mol% or more, and 95 mol% or less, preferably 90 mol% or less, and even more preferably 85 mol% or less, based on the alcohol component (including ethylene glycol units in the polyethylene terephthalate). <7> The toner for developing electrostatic images according to any one of <1> to <6>, wherein the amorphous polyester resin A has an ester group concentration of 3.5 mmol / g or more, preferably 3.7 mmol / g or more, more preferably 4.0 mmol / g or more, and is 12.0 mmol / g or less, preferably 10.0 mmol / g or less, more preferably 6.0 mmol / g or less.<8> The electrostatic image developing toner according to any one of <1> to <7> above, wherein the softening point of the amorphous polyester resin A is 70° C. or higher, preferably 90° C. or higher, more preferably 100° C. or higher, and 170° C. or lower, preferably 160° C. or lower, more preferably 150° C. or lower. <9> The electrostatic image developing toner according to any one of <1> to <8> above, wherein the amorphous polyester resin A contains resins having different softening points, the difference in softening point being 10° C. or higher, preferably 20° C. or higher, and 60° C. or lower, preferably 40° C. or lower. <10> The electrostatic image developing toner according to <9> above, wherein the softening point of the amorphous resin having the higher softening point (resin AH) is 100° C. or higher, preferably 110° C. or higher, more preferably 120° C. or higher, and 170° C. or lower, preferably 160° C. or lower, more preferably 150° C. or lower. <11> The toner for developing electrostatic images according to <9> or <10>, wherein the softening point of the amorphous resin having a lower softening point (resin AL) is 70° C. or higher, preferably 90° C. or higher, more preferably 100° C. or higher, and 130° C. or lower, preferably 125° C. or lower, more preferably 120° C. or lower, and even more preferably 110° C. or lower. <12> The toner for developing electrostatic images according to any one of <9> to <11>, wherein the mass ratio of the amorphous resin having a higher softening point (resin AH) to the amorphous resin having a lower softening point (resin AL) (resin AH / resin AL) is 10 / 90 or higher, preferably 20 / 80 or higher, more preferably 30 / 70 or higher, and 90 / 10 or lower, preferably 80 / 20 or lower, and more preferably 75 / 25 or lower. <13> The toner for developing electrostatic images according to any one of <1> to <12>, wherein the glass transition temperature of the amorphous polyester resin A is 40° C. or higher, preferably 50° C. or higher, and 80° C. or lower, preferably 70° C. or lower. <14> The toner for developing electrostatic images according to any one of <1> to <13>, wherein the content of the amorphous polyester resin A in the binder resin is 70% by mass or higher, preferably 75% by mass or higher, more preferably 80% by mass or higher, and 100% by mass or lower, preferably 99% by mass or lower, more preferably 97% by mass or lower, and even more preferably 95% by mass or lower.<15> The electrostatic image developing toner according to any one of <1> to <14>, wherein the binder resin contains a crystalline polyester resin C. <16> The electrostatic image developing toner according to <15>, wherein the crystalline polyester resin C is a polycondensate of an alcohol component containing an aliphatic diol and a carboxylic acid component containing an aliphatic dicarboxylic acid compound. <17> The electrostatic image developing toner according to <16>, wherein the aliphatic diol has a hydroxyl group at the end of the carbon chain and is preferably an α,ω-linear alkanediol. <18> The electrostatic image developing toner according to <16> or <17>, wherein the content of the aliphatic diol in the alcohol component is 80 mol % or more, preferably 90 mol % or more, more preferably 95 mol % or more, and 100 mol % or less. <19> The electrostatic image developing toner according to any one of the above <16> to <18>, wherein the content of the aliphatic dicarboxylic acid compound in the carboxylic acid component is 50 mol% or more, preferably 60 mol% or more, more preferably 70 mol% or more, and even more preferably 80 mol% or more, and 100 mol% or less. <20> The electrostatic image developing toner according to any one of the above <15> to <19>, wherein the softening point of the crystalline polyester resin C is 50°C or more, preferably 65°C or more, more preferably 70°C or more, and 140°C or less, preferably 120°C or less, and more preferably 100°C or less. <21> The electrostatic image developing toner according to any one of the above <15> to <20>, wherein the melting point of the crystalline polyester resin C is 50°C or more, preferably 65°C or more, more preferably 70°C or more, and 130°C or less, preferably 120°C or less, and more preferably 100°C or less. <22> The electrostatic image developing toner according to any one of <15> to <21>, wherein the content of the crystalline polyester resin C in the binder resin is 1% by mass or more, preferably 3% by mass or more, more preferably 5% by mass or more, and 30% by mass or less, preferably 25% by mass or less, more preferably 20% by mass or less.<23> The electrostatic image developing toner according to any one of the above <15> to <22>, wherein the mass ratio of the crystalline polyester resin C to the amorphous polyester resin A (crystalline polyester resin C / amorphous polyester resin A) is 1 / 99 or more, preferably 3 / 97 or more, more preferably 5 / 95 or more, and 30 / 70 or less, preferably 25 / 75 or less, more preferably 20 / 80 or less. <24> The electrostatic image developing toner according to any one of the above <15> to <23>, wherein the total content of the amorphous polyester resin A and the crystalline polyester resin C in the binder resin is 70% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and even more preferably 100% by mass. <25> The electrostatic image developing toner according to any one of <1> to <24>, wherein the organic yellow pigment has an NH group content of preferably 5.0 mmol / g or more, more preferably 6.0 mmol / g or more, and preferably 12.5 mmol / g or less, more preferably 10.0 mmol / g or less. <26> The electrostatic image developing toner according to any one of <1> to <25>, wherein the organic yellow pigment is at least one selected from the group consisting of benzimidazolone pigments, isoindoline pigments, and condensed disazo pigments. <27> The electrostatic image developing toner according to any one of <1> to <25>, wherein the organic yellow pigment is at least one selected from the group consisting of benzimidazolone pigments and isoindoline pigments, and preferably at least one selected from C.I. Pigment Yellow 180 (PY180) and C.I. Pigment Yellow 185 (PY185). <28> The electrostatic image developing toner according to any one of <1> to <27>, wherein the content of the organic yellow pigment is 1 part by mass or more, preferably 2 parts by mass or more, more preferably 3 parts by mass or more, and 20 parts by mass or less, preferably 18 parts by mass or less, and more preferably 15 parts by mass or less, per 100 parts by mass of the amorphous polyester resin A. <29> The electrostatic image developing toner according to any one of <1> to <28>, wherein the content of the colorant is 1 part by mass or more, preferably 2 parts by mass or more, more preferably 3 parts by mass or more, and 20 parts by mass or less, preferably 18 parts by mass or less, and more preferably 15 parts by mass or less, per 100 parts by mass of the binder resin.<30> The method for producing a toner for developing electrostatic images according to any one of <1> to <29>, further comprising the steps of melting and kneading at least the binder resin and the colorant, and pulverizing the resulting kneaded mixture.

[0104] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Physical properties of resins and the like can be measured by the following methods.

[0105] [IV Value of PET] A PET is dissolved in a 60 / 40 (mass ratio) mixed solvent of phenol / tetrachloroethane at a concentration of 4 g / L, and the IV value is measured using an Ubbelohde viscometer. The IV value is calculated using the following formula: IV = (-1 + √(1 + 4kη)) / (2kC) (where k = 0.33, C = 0.004 g / mL, and η = (t １ / t ０ ) −1(t ０ : Time in seconds for the solvent to fall, t １ : the number of seconds it takes for the sample solution to fall.)

[0106] [Softening Point of Resin] Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), 1 g of a sample is heated at a temperature increase rate of 6°C / min, while a load of 1.96 MPa is applied by the plunger, and the sample is extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. The plunger depression distance of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is taken as the softening point.

[0107] [Maximum endothermic peak temperature of resin] Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of sample is weighed into an aluminum pan, cooled from room temperature (25°C) to 0°C at a temperature decrease rate of 10°C / min, and maintained at 0°C for 1 minute. Thereafter, measurements are made at a temperature increase rate of 10°C / min. Of the endothermic peaks observed, the temperature of the peak with the largest peak area is taken as the maximum endothermic peak temperature. For crystalline resins, the maximum endothermic peak temperature is taken as the melting point.

[0108] [Glass Transition Temperature of Resin] Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of a sample is weighed into an aluminum pan, heated to 200°C, and cooled from that temperature to 0°C at a rate of 10°C / min. The sample is then heated at a rate of 10°C / min, and the endothermic peak is measured. The glass transition temperature is the temperature at the intersection of an extension of the baseline below the maximum endothermic peak temperature and a tangent line showing the maximum slope from the rising part of the peak to the peak apex.

[0109] [Acid value of resin] Measured based on the method of JIS K 0070: 1992. However, only the measurement solvent is changed from the mixed solvent of ethanol and ether specified in JIS K 0070 to a mixed solvent of acetone and toluene (acetone:toluene=1:1 (volume ratio)) for amorphous resins, and to a mixed solvent of chloroform and dimethylformamide (chloroform:dimethylformamide=7:3 (volume ratio)) for crystalline resins.

[0110] [Melting Point of Mold Release Agent] Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of a sample is weighed into an aluminum pan, heated to 200°C, and then cooled from 200°C to 0°C at a temperature decrease rate of 10°C / min. Next, the sample is heated at a temperature increase rate of 10°C / min, the amount of heat is measured, and the maximum endothermic peak temperature is taken as the melting point.

[0111] [Volume median particle diameter and CV value of resin particles, colorant particles, and release agent particles] (1) Measuring device: Laser diffraction particle size measuring instrument "LA-920" (manufactured by Horiba, Ltd.) (2) Measuring conditions: A sample dispersion was placed in a measuring cell, distilled water was added, and the volume median particle diameter (D ５０ The CV value is calculated according to the following formula: CV value (%) = (standard deviation of particle size distribution / volume average particle size) x 100

[0112] [Solid content concentration of resin dispersion, colorant dispersion, and release agent dispersion] Using an infrared moisture meter "FD-230" (manufactured by Kett Electric Laboratory Co., Ltd.), 5 g of a measurement sample is dried at a drying temperature of 150°C and measurement mode 96 (monitoring time 2.5 minutes, fluctuation range 0.05%), and the moisture content (mass %) of the dispersion is measured. The solid content concentration is calculated according to the following formula: Solid content concentration (mass %) = 100 - moisture (mass %)

[0113] [Volume Median Particle Size of Aggregated Particles] Measuring instrument: "Coulter Multisizer (registered trademark) III" (Beckman Coulter, Inc.) Aperture diameter: 50 μm Analysis software: "Multisizer (registered trademark) III Version 3.51" (Beckman Coulter, Inc.) Electrolyte: "Isoton (registered trademark) II" (Beckman Coulter, Inc.) Measurement conditions: A sample dispersion was added to 100 mL of the electrolyte to adjust the concentration so that the particle sizes of 30,000 particles could be measured in 20 seconds, and then 30,000 particles were measured, and the volume median particle size (D ５０ ) is required.

[0114] [Average Particle Diameter of External Additive] The average particle diameter refers to the number-average particle diameter, and is determined by measuring the particle diameters (average values ​​of major and minor axes) of 500 particles in a scanning electron microscope (SEM) photograph and averaging these values ​​by number.

[0115] [Volume median particle size of toner (D ５０) Measuring instrument: "Coulter Multisizer (registered trademark) III" (Beckman Coulter, Inc.) Aperture diameter: 50 μm Analysis software: "Multisizer (registered trademark) III Version 3.51" (Beckman Coulter, Inc.) Electrolyte: "Isoton (registered trademark) II" (Beckman Coulter, Inc.) Dispersion: Polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" (Kao Corporation, HLB (Griffin) = 13.6) was dissolved in electrolyte to adjust the concentration to 5% by mass Dispersion conditions: 10 mg of a measurement sample was added to 5 mL of the dispersion, and the mixture was dispersed for 1 minute using an ultrasonic disperser (machine name: US-1, manufactured by SND Corporation, output: 80 W), and then 25 mL of electrolyte was added and the mixture was further dispersed for 1 minute using the ultrasonic disperser to prepare a sample dispersion. Measurement conditions: The sample dispersion was added to 100 mL of the electrolyte to adjust the concentration so that the particle diameter of 30,000 particles could be measured in 20 seconds. Then, 30,000 particles were measured, and the volume median particle diameter (D ５０ ) is required.

[0116] [Toner Circularity] The circularity of toner particles is measured under the following conditions: Measuring device: Flow type particle image analyzer "FPIA-3000" (manufactured by Sysmex Corporation) Preparation of dispersion: The dispersion of toner particles is diluted with deionized water to prepare a solid content concentration of 0.001 to 0.05% by mass. Measurement mode: HPF measurement mode

[0117] Resin Production Example 1: The alcohol components, carboxylic acid components other than trimellitic anhydride, PET, esterification catalyst, and cocatalyst shown in Tables 1 to 3 were placed in a 10-liter four-neck flask equipped with a nitrogen inlet tube, a downflow condenser with a dehydration tube, a stirrer, and a thermocouple. The mixture was heated to 235°C under a nitrogen atmosphere and then polycondensed at 235°C for 6 hours. The temperature was then lowered to 210°C, and trimellitic anhydride shown in Tables 1 to 3 was added. The mixture was reacted at 210°C for 1 hour, and then further reacted at 210°C under a reduced pressure of 10 kPa until the softening point shown in the table was reached, yielding amorphous polyester resins (resins AH1 to AH8, AH13 to AH16). The physical properties are shown in Tables 1 to 3.

[0118] Resin Production Example 2 The alcohol component, carboxylic acid component, PET, esterification catalyst, and cocatalyst shown in Tables 2 and 5 were placed in a 10-liter four-neck flask equipped with a nitrogen inlet tube, a downflow condenser with a dehydration tube, a stirrer, and a thermocouple. After maintaining the temperature at 180°C for 1 hour under a nitrogen atmosphere, the temperature was increased from 180°C to 235°C at a rate of 10°C / h, and polycondensation was carried out at 235°C for 5 hours. The temperature was then lowered to 210°C and the reaction was continued under a reduced pressure of 10 kPa until the softening point shown in the table was reached, yielding amorphous polyester resins (Resin AH9, Resin AL9). The physical properties are shown in Tables 2 and 5.

[0119] Resin Production Example 3: The alcohol component, carboxylic acid component other than trimellitic anhydride, PET, esterification catalyst, and cocatalyst shown in Table 2 were placed in a 10-liter four-neck flask equipped with a nitrogen inlet tube, a downflow condenser with a dehydration tube, a stirrer, and a thermocouple. The mixture was heated to 235°C under a nitrogen atmosphere and then polycondensed at 235°C for 10 hours. The temperature was then lowered to 210°C, and trimellitic anhydride shown in Table 2 was added. The mixture was reacted at 210°C for 1 hour, and then further reacted at 210°C under a reduced pressure of 10 kPa until the softening point shown in Table 2 was reached, resulting in an amorphous polyester resin (Resin AH10). The physical properties are shown in Table 2.

[0120] Resin Production Example 4 The alcohol components, carboxylic acid components other than trimellitic anhydride, esterification catalyst, and cocatalyst shown in Table 2 were placed in a 5-liter four-neck flask equipped with a nitrogen inlet tube, a dehydration tube equipped with a fractionating column through which hot water of 98 ° C. was passed, a stirrer, and a thermocouple. After holding at 180 ° C. for 1 hour under a nitrogen atmosphere, the mixture was heated from 180 ° C. to 235 ° C. at a rate of 10 ° C. / h, and then polycondensed at 235 ° C. for 5 hours. The temperature was then lowered to 210 ° C., and trimellitic anhydride shown in Table 2 was added. The mixture was reacted at 210 ° C. for 1 hour, and then further reacted at 210 ° C. under a reduced pressure of 10 kPa until the softening point listed in Table 2 was reached, resulting in an amorphous polyester resin (resin AH11). The physical properties are shown in Table 2.

[0121] Resin Production Example 5 The alcohol component, carboxylic acid component other than trimellitic anhydride, esterification catalyst, and cocatalyst shown in Table 2 were placed in a 10-liter four-neck flask equipped with a nitrogen inlet tube, a downflow condenser with a dehydration tube, a stirrer, and a thermocouple, and the mixture was heated to 235°C under a nitrogen atmosphere and then polycondensed at 235°C for 6 hours. The temperature was then lowered to 210°C, and trimellitic anhydride shown in Table 2 was added. The mixture was reacted at 210°C for 1 hour, and then further reacted at 210°C under a reduced pressure of 10 kPa until the softening point shown in Table 2 was reached, resulting in an amorphous polyester resin (Resin AH12). The physical properties are shown in Table 2.

[0122] Resin Production Example 6: The alcohol component, carboxylic acid component, PET, esterification catalyst, and cocatalyst shown in Tables 4 to 6 were placed in a 10-liter four-neck flask equipped with a nitrogen inlet tube, a downflow condenser with a dehydration tube, a stirrer, and a thermocouple, and the temperature was raised to 235°C under a nitrogen atmosphere, followed by polycondensation at 235°C for 6 hours. The temperature was then lowered to 210°C, and the reaction was continued under a reduced pressure of 10 kPa until the softening points shown in Tables 4 to 6 were reached, yielding amorphous polyester resins (resins AL1 to AL8, AL13 to AL16). The physical properties are shown in Tables 4 to 6.

[0123] Resin Production Example 7 The alcohol component, carboxylic acid component, PET, esterification catalyst, and cocatalyst shown in Table 5 were placed in a 10-liter four-neck flask equipped with a nitrogen inlet tube, a downflow condenser with a dehydration tube, a stirrer, and a thermocouple, and the mixture was heated to 235 ° C under a nitrogen atmosphere, and then polycondensed at 235 ° C for 10 hours. The temperature was then lowered to 210 ° C, and the reaction was continued under a reduced pressure of 10 kPa until the softening point shown in Table 5 was reached, resulting in an amorphous polyester resin (resin AL10). The physical properties are shown in Table 5.

[0124] Resin Production Example 8 The alcohol component, carboxylic acid component, esterification catalyst, and cocatalyst shown in Table 5 were placed in a 5-liter four-neck flask equipped with a nitrogen inlet tube, a dehydration tube equipped with a fractionating column through which hot water of 98 ° C. was passed, a stirrer, and a thermocouple, and then heated at 180 ° C. for 1 hour under a nitrogen atmosphere, and then heated from 180 ° C. to 235 ° C. at a rate of 10 ° C. / h, and then polycondensed at 235 ° C. for 5 hours. Then, the temperature was lowered to 210 ° C. and the reaction was continued under a reduced pressure of 10 kPa until the softening point listed in Table 5 was reached, to obtain an amorphous polyester resin (resin AL11). The physical properties are shown in Table 5.

[0125] Resin Production Example 9 The alcohol component, carboxylic acid component, esterification catalyst, and cocatalyst shown in Table 5 were placed in a 10-liter four-neck flask equipped with a nitrogen inlet tube, a downflow condenser with a dehydration tube, a stirrer, and a thermocouple, and the mixture was heated to 235 ° C under a nitrogen atmosphere, and then polycondensed at 235 ° C for 6 hours. The temperature was then lowered to 210 ° C, and the reaction was continued under a reduced pressure of 10 kPa until the softening point shown in Table 5 was reached, resulting in an amorphous polyester resin (resin AL12). The physical properties are shown in Table 5.

[0126]

[0127]

[0128]

[0129]

[0130]

[0131]

[0132] Resin Production Example 10 The alcohol component and carboxylic acid component shown in Table 7 were placed in a 10-liter four-neck flask equipped with a thermometer, a stainless steel stirring rod, a downflow condenser with a dehydration tube, and a nitrogen inlet tube, and the temperature was raised to 200°C over 8 hours in a nitrogen atmosphere in a mantle heater. The esterification catalyst shown in Table 7 was then added, and the reaction was carried out at 8.0 kPa until the softening point shown in Table 7 was reached, yielding a crystalline polyester resin (Resin C1). The physical properties are shown in Table 7.

[0133]

[0134] Examples 1 to 6, 8 to 11, 14 to 18, and Comparative Examples 2 and 3 (Melt-Kneading Method) 100 parts by mass of a binder resin shown in Table 8, 5 parts by mass of a colorant "Toner Yellow HG" (manufactured by Clariant, C.I. Pigment Yellow 180), 3 parts by mass of a release agent "Carnauba Wax C1" (manufactured by Kato Yoko Co., Ltd., melting point: 83°C), and 0.5 parts by mass of a negatively chargeable charge control agent "Bontron E-304" (manufactured by Orient Chemical Industries Co., Ltd.) were mixed in a Henschel mixer.

[0135] The resulting mixture was melt-kneaded using a co-rotating twin-screw extruder having a kneading section with a total length of 1560 mm, a screw diameter of 42 mm, and a barrel inner diameter of 43 mm at a screw rotation speed of 200 r / min and a barrel temperature setting of 100° C. to obtain a melt-kneaded product. The feed rate of the mixture was 20 kg / h, and the average residence time was about 18 seconds.

[0136] The resulting melt-kneaded product was cooled and coarsely crushed, then crushed in a jet mill, and classified using an air classifier (manufactured by Nippon Pneumatic Mfg. Co., Ltd.) to obtain a volume median particle size (D ５０ ) toner particles of 7.0 μm were obtained.

[0137] 100 parts by mass of the obtained toner particles and, as external additives, 1.0 part by mass of hydrophobic silica "R972" (manufactured by Nippon Aerosil Co., Ltd., hydrophobic treatment agent: DMDS, average particle size: 16 nm) and 1.0 part by mass of hydrophobic silica "RY-50" (manufactured by Nippon Aerosil Co., Ltd., hydrophobic treatment agent: silicone oil, average particle size: 40 nm) were mixed in a Henschel mixer at a rotation speed of 3000 r / min (circumferential speed: 32 m / sec) for 3 minutes to obtain a yellow toner.

[0138] Example 7 A yellow toner was obtained in the same manner as in Example 1, except that "Paliotol Yellow D1155" (manufactured by Sun Chemical Co., Ltd., C.I. Pigment Yellow 185) was used instead of the colorant "Toner Yellow HG" (manufactured by Clariant, C.I. Pigment Yellow 180).

[0139] Comparative Example 1 In Example 1, the colorant "Toner Yellow HG" (manufactured by Clariant, C.I. Pigment Yellow 180) was replaced with "Toner Yellow 3GP-CT" (manufactured by Clariant, C.I. Pigment Yellow 155 (having -NH- group and -NH- group in one molecule) ２ A yellow toner was obtained in the same manner as in Example 1, except that the total number of groups was 2, the molecular weight was 717, and the amount of NH groups was 2.8 mmol / g.

[0140] Comparative Example 4 In Example 1, the colorant "Toner Yellow HG" (manufactured by Clariant, C.I. Pigment Yellow 180) was replaced with "HANSA Yellow 5GX01" (manufactured by Clariant, C.I. Pigment Yellow 74 (having -NH- group and -NH- group in one molecule)). ２ A yellow toner was obtained in the same manner as in Example 1, except that the total number of groups=1, the molecular weight=386, and the amount of NH groups=2.6 mmol / g) were used.

[0141] Example 12 A yellow toner was obtained in the same manner as in Example 1, except that a continuous twin-open-roll kneader "Kneedex" (manufactured by Nippon Coke and Engineering Co., Ltd.) was used instead of the co-rotating twin-screw extruder during melt kneading. The continuous twin-open-roll kneader had a roll outer diameter of 0.14 m and an effective roll length of 0.8 m. The operating conditions were a rotation speed of the high-speed roll (front roll) of 75 r / min (circumferential speed of 33 m / min), a rotation speed of the low-speed roll (rear roll) of 50 r / min (circumferential speed of 22 m / min), and a roll gap of 0.1 mm. The heating and cooling medium temperatures within the rolls were set as follows: the temperature on the raw material inlet side of the high-speed roll was 140°C, and the temperature on the kneaded material discharge side was 110°C; and the temperature on the raw material inlet side of the low-speed roll was 65°C, and the temperature on the kneaded material discharge side was 30°C. The raw material mixture was supplied at a rate of 10 kg / h, and the average residence time was approximately 5 minutes.

[0142] Example 13 [Emulsion aggregation method] <Preparation of aqueous dispersion of core resin particles> 600 g of methyl ethyl ketone was placed in a 5-liter container equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, and 129 g of resin AH1 and 21 g of resin C1 were added and dissolved at 60°C. A 5% by mass aqueous solution of sodium hydroxide was added to the resulting solution so that the degree of neutralization relative to the acid value of the resin was 60 mol%, and the mixture was stirred for 30 minutes to obtain a mixture. Subsequently, 675 g of deionized water was added over 77 minutes. Next, while stirring at 250 r / min, the methyl ethyl ketone was distilled off under reduced pressure at a temperature of 50°C or less, and the solids concentration of the aqueous dispersion was measured. The solids concentration of the aqueous dispersion was adjusted to 20% by mass with deionized water to obtain a core resin dispersion. The volume median particle diameter (D ５０ ) was 200 nm and the CV value was 24%.

[0143] <Preparation of aqueous dispersion of shell resin particles> 600 g of methyl ethyl ketone was placed in a 5-liter container equipped with a stirrer, reflux condenser, dropping funnel, thermometer, and nitrogen inlet tube, and 150 g of resin AL1 was added at 60 ° C. and dissolved. A 5% by mass aqueous solution of sodium hydroxide was added to the resulting solution so that the degree of neutralization was 60 mol% relative to the acid value of the resin, and the mixture was stirred for 30 minutes to obtain a mixture. Subsequently, 675 g of deionized water was added over 77 minutes. Next, while stirring at 250 r / min, methyl ethyl ketone and a portion of the water were distilled off under reduced pressure at a temperature of 50 ° C. or less, and the solids concentration of the aqueous dispersion was measured. The solids concentration of the aqueous dispersion was adjusted to 20% by mass with deionized water to obtain a shell resin dispersion. The volume median particle size (D ５０ ) was 130 nm and the CV value was 22%.

[0144] <Preparation of Colorant Dispersion> Into a 1-liter beaker, 116.2 g of colorant "Toner Yellow HG" (manufactured by Clariant, C.I. Pigment Yellow 180), 154.9 g of anionic surfactant "Neopelex (registered trademark) G-15" (manufactured by Kao Corporation, 15% by mass aqueous solution of sodium dodecylbenzenesulfonate), and 260 g of deionized water were mixed and dispersed using a homogenizer at room temperature for 3 hours, and then deionized water was added so that the solids concentration became 24% by mass, thereby obtaining a colorant dispersion. The volume median particle diameter (D ５０ ) was 140 nm and the CV value was 28%.

[0145] <Preparation of Release Agent Dispersion> 50 g of Fischer-Tropsch wax (manufactured by Nippon Seiro Co., Ltd., trade name: FNP0090, melting point: 90°C), 5 g of a cationic surfactant (manufactured by Kao Corporation, trade name: Sanisol B50) and 200 g of deionized water were heated to 95°C, and the wax was dispersed using a homogenizer. The mixture was then subjected to a dispersion treatment using a pressure discharge homogenizer, thereby obtaining a release agent dispersion having a solids concentration of 20% by mass. The volume median particle diameter (D ５０ ) was 550 nm and the CV value was 26%.

[0146] <Preparation of Toner Particles> 500 g of the core resin dispersion, 36 g of the colorant dispersion, 33 g of the release agent dispersion, and 3.3 g of a 15% by mass aqueous solution of sodium dodecylbenzenesulfonate "Neopelex G-15" (manufactured by Kao Corporation, an anionic surfactant) were mixed at a temperature of 25°C in a 3-liter four-neck flask equipped with a reflux condenser, a stirrer, and a thermocouple. Next, while stirring the resulting mixture, a solution prepared by dissolving 40 g of ammonium sulfate in 570 g of deionized water and adding a 4.8% by mass aqueous solution of potassium hydroxide to adjust the pH to 8.2 was added dropwise over 10 minutes at 25°C, and the temperature was then raised to 62°C over 2 hours to measure the volume median particle diameter (D ５０ The temperature was maintained at 62° C. until the particle size reached 7.1 μm, thereby obtaining a dispersion of aggregated particles (I).

[0147] While maintaining the temperature of the obtained dispersion of aggregated particles (I) at 62° C., 215 g of the shell resin dispersion was added dropwise at a rate of 0.6 mL / min (0.6 g / min) to obtain a dispersion of aggregated particles (II). ５０ ) was 7.0 μm.

[0148] To the resulting dispersion of aggregated particles (II), an aqueous solution prepared by mixing 20 g of polyoxyethylene lauryl ether sodium sulfate "EMAL E-27C" (manufactured by Kao Corporation, anionic surfactant, effective concentration 27% by mass), 280 g of deionized water, and 40 g of a 0.1 mol / L aqueous sulfuric acid solution was added. The mixture was then heated to 80°C over 1 hour and maintained at 80°C for 30 minutes. Thereafter, 10 g of a 0.1 mol / L aqueous sulfuric acid solution was added, and the mixture was further maintained at 80°C for 15 minutes. Thereafter, 15 g of a 0.1 mol / L aqueous sulfuric acid solution was added again, and the mixture was maintained at 80°C until the circularity reached 0.970, thereby obtaining a dispersion of fused particles (core-shell particles) in which the aggregated particles were fused together.

[0149] The obtained core-shell particle dispersion was cooled to 30°C, and the dispersion was subjected to suction filtration to separate the solid content. The solid content was then washed with deionized water at 25°C and suction filtration was carried out at 25°C for 2 hours. Thereafter, the solid content was vacuum dried at 33°C for 24 hours using a vacuum constant temperature dryer "DRV622DA" (manufactured by ADVANTEC) to obtain toner particles. The volume median particle diameter (D ５０ The particle diameter was 7.0 μm and the circularity was 0.970. The composition ratio (mass ratio) of the binder resin of the obtained toner particles was resin AH1 / resin AL1 / resin C1=60 / 30 / 10.

[0150] 100 parts by mass of the obtained toner particles and, as external additives, 1.0 part by mass of hydrophobic silica "R972" (manufactured by Nippon Aerosil Co., Ltd., hydrophobic treatment agent: DMDS, average particle size: 16 nm) and 1.0 part by mass of hydrophobic silica "RY-50" (manufactured by Nippon Aerosil Co., Ltd., hydrophobic treatment agent: silicone oil, average particle size: 40 nm) were mixed in a Henschel mixer at a rotation speed of 3000 r / min (circumferential speed: 32 m / sec) for 3 minutes to obtain a yellow toner.

[0151] Test Example [Smearing of Printed Matter] Toner was loaded into a copying machine "AR-505" (trade name, manufactured by Sharp Corporation), and a solid image was removed before passing through the fixing machine to obtain a printed matter in an unfixed state (printed area: 2 cm x 12 cm, adhesion amount: 0.5 mg / cm ２ Furthermore, an unfixed image was printed twice on the same paper, and the amount of adhesion was 1.5 mg / cm ２ The unfixed image thus obtained was fixed at 150° C. and 300 mm / s to obtain a printed matter.

[0152] A stainless steel weight measuring 3 cm in length, 3 cm in width, and 6.5 cm in height, weighing 500 g, was placed on the resulting print and moved back and forth over the print at a speed of 0.5 m / s. One reciprocation was counted as one cycle, with a maximum of 50 cycles. The number of times that black bands of toner deposits appeared in non-printed areas was visually confirmed and smearing was evaluated. The results are shown in Table 8. A higher number indicates better smearing. In the table, ">50" indicates that no toner deposits were observed even after 50 cycles.

[0153]

[0154] The above results show that the toners of Examples 1 to 18 have good smear properties compared to the toners of Comparative Examples 1 and 4, which contain an organic yellow pigment with a small amount of NH groups, and the toners of Comparative Examples 2 and 3, which do not use PET. In particular, Comparative Example 2 shows that using ethylene glycol and terephthalic acid, which are monomer components of PET, has no effect, and that it is important to use PET.

[0155] The toner for developing electrostatic images of the present invention is suitably used for developing latent images formed in electrophotography, electrostatic recording, electrostatic printing and the like.

Claims

1. A toner for developing electrostatic images, comprising a binder resin and a colorant, the binder resin comprising an amorphous polyester resin A which is a polycondensation product of polyethylene terephthalate, an alcohol component and a carboxylic acid component, the colorant comprising an -NH- group and an -NH ２ The toner for developing electrostatic images contains an organic yellow pigment having an NH group amount of 4.0 mmol / g or more and 15.0 mmol / g or less, where the NH group amount is the total number of groups divided by the molecular weight.

2. The toner for developing electrostatic images according to claim 1, wherein the content of polyethylene terephthalate is 5 mol % or more and 75 mol % or less of the total amount of the alcohol component, the carboxylic acid component and the polyethylene terephthalate, assuming that the terephthalic acid-ethylene glycol unit is 1 mol.

3. The toner for developing electrostatic images according to claim 1, wherein the content of polyethylene terephthalate is 10 mol % or more and 50 mol % or less of the total amount of the alcohol component, the carboxylic acid component and the polyethylene terephthalate, assuming that the terephthalic acid-ethylene glycol unit is 1 mol.

4. The toner for developing electrostatic images according to any one of claims 1 to 3, wherein the IV value of the polyethylene terephthalate is from 0.40 to 0.

85.

5. The toner for developing electrostatic images according to any one of claims 1 to 4, wherein the organic yellow pigment is at least one selected from the group consisting of benzimidazolone pigments, isoindoline pigments, and condensed disazo pigments.

6. The toner for developing electrostatic images according to any one of claims 1 to 4, wherein the organic yellow pigment is at least one selected from the group consisting of C. I. Pigment Yellow 180 and C. I. Pigment Yellow 185.

7. The toner for developing electrostatic images according to any one of claims 1 to 6, wherein the amorphous polyester resin A has an ester group concentration of 3.5 mmol / g or more and 12.0 mmol / g or less.

8. The toner for developing electrostatic images according to any one of claims 1 to 7, wherein the content of the organic yellow pigment is from 1 part by mass to 20 parts by mass per 100 parts by mass of the amorphous polyester resin A.

9. The toner for developing electrostatic images according to any one of claims 1 to 8, wherein the binder resin further contains a crystalline polyester resin C.

10. The toner for developing electrostatic images according to any one of claims 1 to 9, wherein the amorphous polyester resin A contains resins having different softening points with a difference of 10°C or more.

11. The method for producing a toner for developing electrostatic images according to any one of claims 1 to 10, comprising the steps of melting and kneading at least said binder resin and said colorant, and pulverizing the resulting kneaded mixture.

Images