Toner for developing electrostatic images

Abstract

Relates to an electrostatic charge image developing toner having excellent rubbing fastness. 【Solution means】An electrostatic charge image developing toner containing a crystalline polyester resin, an amorphous polyester resin, a yellow pigment, and a hydroxy group-containing amide compound, wherein the amount of NH groups in the yellow pigment is 4.0 mmol / g or more and 15.0 mmol / g or less, and the hydroxy group-containing amide compound is of the formula (I): R 1 -CONH-X-NHCO-R 2 (I) Or of the formula (II): R 3 -CONH-R 4 (II) And is a compound represented by the above formula, and the content of the hydroxy group-containing amide compound is 0.4 parts by mass or more and 13 parts by mass or less with respect to 100 parts by mass of the total amount of the crystalline polyester resin and the amorphous polyester resin, an electrostatic charge image developing toner.

Description

[Technical Field]

[0001] The present invention relates to an electrostatic image developing toner used for developing latent images formed in electrophotography, electrostatic recording, electrostatic printing, and the like. [Background technology]

[0002] From the viewpoint of preservation, durability, and electrostatic properties, the use of amide compounds as toner raw materials, along with crystalline polyester resins and amorphous polyester resins, is being considered (see Patent Documents 1-4).

[0003] Furthermore, it is known that disazo pigments, as yellow pigments, suppress the decrease in electrostatic properties after high-temperature, high-humidity storage of toner (see Patent Document 5). [Prior art documents] [Patent Documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2019-8249 [Patent Document 2] Japanese Patent Publication No. 2019-95543 [Patent Document 3] Japanese Patent Publication No. 2009-251192 [Patent Document 4] Japanese Patent Publication No. 2009-251193 [Patent Document 5] Japanese Patent Publication No. 2020-154154 [Overview of the project] [Problems that the invention aims to solve]

[0005] In recent years, toner-based printing has become increasingly common in industrial and commercial printing. However, in such printing applications, where a large amount of toner adheres to the paper surface and images with significant surface irregularities are frequently used, there is a need to improve the scratch resistance of printed materials. However, disazo pigments have problems such as low image hardness and poor rubbing resistance of printed matter.

[0006] The present invention relates to an electrostatic charge image developing toner having excellent rubbing resistance.

Means for Solving the Problems

[0007] The present invention is an electrostatic charge image developing toner containing a crystalline polyester resin, an amorphous polyester resin, a yellow pigment, and a hydroxy group-containing amide compound, wherein the amount of NH groups in the yellow pigment is 4.0 mmol / g or more and 15.0 mmol / g or less, and the hydroxy group-containing amide compound is represented by the formula (I): R 4 , , , ,

[0008] , ,

[0009] , , , , , -CONH-X-NHCO-R 2 (I) (In the formula, R 1 and R 2 are each independently a hydroxyalkyl group having 12 to 22 carbon atoms, and X is a divalent hydrocarbon group having 2 to 12 carbon atoms) or the formula (II): R 3 -CONH-R 4 (II) ​​​​​​​​​​​​​​​​​​​​The electrostatic image developing toner of the present invention is characterized by containing a crystalline polyester resin, an amorphous polyester resin, a yellow pigment, and an amide compound, wherein the yellow pigment has a predetermined amount of NH groups, and the amide compound is a predetermined hydroxyl group-containing amide compound. Although the exact reason for the effects of this invention is unclear, it is presumed that the NH groups of these yellow pigments and the NH and OH groups of the hydroxyl group-containing amide compound form hydrogen bonds, creating a fine network structure throughout the toner, thereby improving the overall elasticity of the toner. Therefore, it is presumed that the hardness of the printed image increases, and the scratch resistance of the printed material improves. However, the above mechanism is a hypothesis and is not limited to this.

[0010] The crystalline or amorphous nature of a resin is determined by its crystallinity index. The crystallinity index is defined as the ratio of the resin's softening point to its maximum endothermic peak temperature (softening point (°C) / maximum endothermic peak temperature (°C)) in the measurement method described in the examples below. A crystalline resin is one in which the crystallinity index is between 0.6 and 1.4. An amorphous resin is one in which no endothermic peak is observed, or if observed, the crystallinity index is less than 0.6 or greater than 1.4. The crystallinity of a resin can be adjusted by the type and ratio of raw material monomers, as well as the manufacturing conditions (e.g., reaction temperature, reaction time, cooling rate). The maximum endothermic peak temperature refers to the temperature of the peak with the largest peak area among the observed endothermic peaks. In crystalline resins, the maximum endothermic peak temperature is defined as the melting point.

[0011] Examples of crystalline polyester resins include crystalline polyester resins, composite resins containing crystalline polyester resins and vinyl resins such as styrene-acrylic resins, epoxy resins, polycarbonate, polyurethane, and other resins. Among these, crystalline polyester resins are preferred.

[0012] As for the crystalline polyester resin, a polycondensate of an alcohol component containing an aliphatic diol and a carboxylic acid component is preferred.

[0013] Examples of aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-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.

[0014] The aliphatic diol has two or more carbon atoms, and from the viewpoint of low-temperature fixability, it is preferably 12 or less, more preferably 6 or less, and even more preferably 4 or less.

[0015] From the viewpoint of improving the low-temperature fixability of the toner, aliphatic diols are preferably those having a hydroxyl group at the end of the carbon chain, and more preferably α,ω-linear alkanediols.

[0016] As the aliphatic diol, an aliphatic diol having 2 to 6 carbon atoms is preferred, and ethylene glycol is more preferred.

[0017] The aliphatic diol content is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and 100 mol% or less, in the alcohol component.

[0018] Examples of alcohol components other than aliphatic diols include alkylene oxide adducts of bisphenol A, aromatic diols such as bisphenol A, hydrogenated bisphenol A, sorbitol, pentaerythritol, glycerin, trivalent or higher alcohols such as trimethylolpropane, etc.

[0019] The carboxylic acid component preferably contains an aliphatic dicarboxylic acid compound.

[0020] Examples of aliphatic dicarboxylic acid compounds include succinic acid (4 carbon atoms), fumaric acid (4 carbon atoms), adipic acid (6 carbon atoms), suberic acid (8 carbon atoms), azelaic acid (9 carbon atoms), sebacic acid (10 carbon atoms), dodecanediic acid (12 carbon atoms), tetradecanediic acid (14 carbon atoms), anhydrides of these acids, and alkyl esters of these acids with 1 to 3 carbon atoms.

[0021] From the viewpoint of heat-resistant storage, the carbon number of the aliphatic dicarboxylic acid compound is preferably 10 or more, more preferably 12 or more, and from the viewpoint of low-temperature fixability, it is preferably 16 or less, more preferably 14 or less. Here, the carbon number of the alkyl group when the aliphatic dicarboxylic acid compound is an alkyl ester is not included in the above carbon number.

[0022] The content of aliphatic dicarboxylic acid compounds in the carboxylic acid component is preferably 50 mol% or more, more preferably 60 mol% or more, even more preferably 70 mol% or more, even more preferably 80 mol% or more, and 100 mol% or less, from the viewpoint of hydrophobicity. If the carboxylic acid component includes aliphatic monocarboxylic acid compounds, the content is preferably 98 mol% or less, more preferably 97 mol% or less.

[0023] From the viewpoint of heat resistance and storage properties, it is preferable that the carboxylic acid component further contains an aliphatic monocarboxylic acid compound.

[0024] Examples of aliphatic monocarboxylic acid compounds include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, and alkyl esters of these acids in which the alkyl group has 1 to 3 carbon atoms.

[0025] From the viewpoint of glossiness, the carbon number of the aliphatic monocarboxylic acid compound is preferably 12 or more, more preferably 18 or more, and even more preferably 20 or more. From the viewpoint of low-temperature fixability, it is preferably 30 or less, more preferably 24 or less, and even more preferably 22 or less. Here, the carbon number of the alkyl group when the aliphatic monocarboxylic acid compound is an alkyl ester is not included in the above carbon number.

[0026] When the carboxylic acid component contains an aliphatic monocarboxylic acid compound, the content of the aliphatic monocarboxylic acid compound is preferably 2 mol% or more, more preferably 3 mol% or more, and preferably 15 mol% or less, and more preferably 10 mol% or less, in the carboxylic acid component.

[0027] 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.

[0028] In this specification, macromonomers and hydroxycarboxylic acids are not included in the alcohol and carboxylic acid components.

[0029] 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 0.7 or higher, more preferably 0.8 or higher, from the viewpoint of electrostatic stability, and preferably 1.3 or lower, more preferably 1.2 or lower, from the viewpoint of low-temperature fixability.

[0030] Crystalline polyester resins can be produced, for example, by polycondensing an alcohol component and a carboxylic acid component in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and optionally in the presence of a co-catalyst, polymerization inhibitor, etc., at a temperature preferably 120°C or higher, more preferably 180°C or higher, and preferably 230°C or lower, more preferably 220°C or lower.

[0031] Examples of esterification catalysts include tin compounds such as dibutyltin oxide and tin(II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropoxybis(triethanolamine) and titanium dihydroxybis(triethanolamine). The amount of 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 amount of alcohol and carboxylic acid components. Examples of co-catalysts for the esterification catalyst include gallic acid. The amount of co-catalyst 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 amount of alcohol and carboxylic acid components. Examples of polymerization inhibitors include tert-butylcatechol. The amount of polymerization inhibitor 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, based on 100 parts by mass of the total amount of alcohol and carboxylic acid components.

[0032] In this invention, the polyester resin may be a polyester resin that has been modified to such an extent that its properties are not substantially impaired. Examples of modified polyester resins include polyester resins that have been grafted or blocked with phenol, urethane, epoxy, etc., by methods described in Japanese Patent Publication No. 11-133668, Japanese Patent Publication No. 10-239903, Japanese Patent Publication No. 8-20636, etc. Among modified polyester resins, urethane-modified polyester resins obtained by urethane elongation of polyester resin with a polyisocyanate compound are preferred.

[0033] The softening point of the crystalline polyester resin is preferably 50°C or higher, more preferably 65°C or higher, and even more preferably 70°C or higher, from the viewpoint of hot offset resistance, and preferably 120°C or lower, more preferably 110°C or lower, from the viewpoint of low-temperature fixation.

[0034] The melting point of the crystalline polyester resin is preferably 45°C or higher, more preferably 60°C or higher, and even more preferably 65°C or higher, from the viewpoint of heat-resistant storage, and preferably 115°C or lower, more preferably 105°C or lower, from the viewpoint of low-temperature fixation.

[0035] The ratio of the softening point to the melting point (softening point / melting point) of the crystalline polyester resin is preferably 0.7 or higher, more preferably 0.9 or higher, and preferably 1.3 or lower, more preferably 1.2 or lower.

[0036] The weight-average molecular weight of the crystalline polyester resin is preferably 10,000 or more, more preferably 15,000 or more, from the viewpoint of heat-resistant storage, and preferably 30,000 or less, more preferably 25,000 or less, from the viewpoint of low-temperature fixation.

[0037] From the viewpoint of low-temperature fixability, the content of crystalline polyester resin in the total amount of crystalline polyester resin and amorphous polyester resin is preferably 5% by mass or more, more preferably 8% by mass or more, even more preferably 10% by mass or more, and preferably 25% by mass or less, more preferably 20% by mass or less, and even more preferably 17% by mass or less.

[0038] Examples of amorphous polyester resins include amorphous polyester resins, composite resins containing amorphous polyester resin and vinyl resins such as styrene-acrylic resin, epoxy resins, polycarbonate, polyurethane, and other resins. Among these, amorphous polyester resins are preferred.

[0039] As the amorphous polyester resin, an amorphous polyester resin that is a polycondensate of an alcohol component containing an alkylene oxide adduct of bisphenol A and a carboxylic acid component is preferred.

[0040] The alkylene oxide adduct of bisphenol A is given by formula (III):

[0041] [Chemical]

[0042] (wherein, OR 5 and R 5 O is an oxyalkylene group, R 5 is an ethylene group and / or a propylene group, x and y represent the average number of moles of alkylene oxide added, and are each a positive number. The value of 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) Compounds represented by are preferred, and examples include ethylene oxide adducts of bisphenol A, propylene oxide adducts of bisphenol A, and the like.

[0043] From the viewpoint of low-temperature fixing properties, the content of the alkylene oxide adduct of bisphenol A in the alcohol component is preferably 40 mol% or more, more preferably 60 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and 100 mol% or less.

[0044] Other alcohol components include aliphatic diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,6-hexanediol, neopentyl glycol, and polyhydric alcohols with three or more valences such as bisphenol A, hydrogenated bisphenol A, sorbitol, pentaerythritol, glycerin, trimethylolpropane, and the like.

[0045] Examples of the carboxylic acid component include aromatic dicarboxylic acid compounds, aliphatic dicarboxylic acid compounds, carboxylic acid compounds with three or more valences, and the like.

[0046] Examples of the 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.

[0047] The content of aromatic dicarboxylic acid compounds is preferably 40 mol% or more, more preferably 70 mol% or more, and preferably 95 mol% or less, and more preferably 90 mol% or less, in the carboxylic acid component, from the viewpoint of heat resistance and storage.

[0048] Examples of aliphatic dicarboxylic acid compounds include fumaric acid, maleic acid, succinic acid, succinic acid derivatives substituted with hydrocarbon groups, glutaric acid, adipic acid, sebacic acid, anhydrides of these acids, and alkyl esters of these acids with 1 to 3 carbon atoms.

[0049] Examples of carboxylic acid compounds with a valency of 3 or higher include trimellitic acid, pyromellitic acid, anhydrides of these acids, and alkyl esters of these acids with 1 to 3 carbon atoms.

[0050] The alcohol component may contain a monohydric alcohol, and the carboxylic acid component may contain a monohydric carboxylic acid compound, as appropriate.

[0051] The equivalent ratio (COOH group / OH group) of the carboxyl group of the carboxylic acid component to the hydroxyl group of the alcohol component is preferably 0.6 or higher, more preferably 0.7 or higher, even more preferably 0.8 or higher, and preferably 1.3 or lower, more preferably 1.2 or lower, from the viewpoint of adjusting the softening point of the polyester resin.

[0052] The polycondensation reaction conditions between the alcohol component and the carboxylic acid component of the amorphous polyester resin are the same as those for the crystalline polyester resin, except that the preferred reaction temperature is 160°C or higher, more preferably 200°C or higher, and 250°C or lower, more preferably 240°C or lower.

[0053] The softening point of amorphous polyester resin is preferably 70°C or higher, more preferably 85°C or higher, and even more preferably 100°C or higher, from the viewpoint of electrostatic stability, and 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.

[0054] From the viewpoint of low-temperature fixability and fixation width, the amorphous polyester resin is preferably composed of amorphous polyester resins with different softening points. The difference in softening points between the two amorphous polyester resins is preferably 10°C or more, more preferably 15°C or more, and preferably 60°C or less, more preferably 50°C or less.

[0055] The softening point of the amorphous polyester resin (resin AH) with a high softening point is preferably 100°C or higher, more preferably 110°C or higher, from the viewpoint of fixing width, and 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 fixing properties.

[0056] The weight-average molecular weight of resin AH is preferably 50,000 or more, more preferably 100,000 or more, and preferably 200,000 or less, more preferably 150,000 or less.

[0057] Furthermore, the softening point of the amorphous polyester resin (resin AL) with a lower softening point is preferably 70°C or higher, more preferably 85°C or higher, from the viewpoint of electrostatic stability, and preferably 120°C or lower, more preferably 110°C or lower, and even more preferably 100°C or lower, from the viewpoint of low-temperature fixation.

[0058] The weight-average molecular weight of resin AL is preferably 3,000 or more, more preferably 4,000 or more, and preferably 9,000 or less, more preferably 8,000 or less.

[0059] The mass ratio of resin AL to resin AH (resin AL / resin AH) is preferably 55 / 45 or more, more preferably 60 / 40 or more, even more preferably 65 / 35 or more, and preferably 90 / 10 or less, more preferably 85 / 15 or less, and even more preferably 80 / 20 or less.

[0060] The glass transition temperature of amorphous polyester resin is preferably 40°C or higher from the viewpoint of storage properties, and preferably 80°C or lower, more preferably 70°C or lower, from the viewpoint of electrostatic stability.

[0061] The content of amorphous polyester 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 100% by mass or less, in the amorphous polyester resin.

[0062] Furthermore, the content of amorphous polyester resin in the total amount of amorphous polyester resin and crystalline polyester resin is preferably 75% by mass or more, more preferably 80% by mass or more, even more preferably 83% by mass or more, and preferably 95% by mass or less, more preferably 92% by mass or less, and even more preferably 90% by mass or less.

[0063] The mass ratio of crystalline polyester resin to amorphous polyester resin (crystalline polyester resin / amorphous polyester resin) is preferably 5 / 95 or more, more preferably 8 / 92 or more, even more preferably 10 / 90 or more, and preferably 25 / 75 or less, more preferably 20 / 80 or less, and even more preferably 17 / 83 or less.

[0064] In the toner of the present invention, crystalline polyester resin and amorphous polyester resin are contained as binder resins (binders).

[0065] The total content of crystalline polyester resin and amorphous polyester resin 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 100% by mass or less.

[0066] Other binder resins include vinyl resins such as styrene-acrylic resin, polyamide resin, epoxy resin, polycarbonate resin, polyurethane resin, and composite resins containing two or more of these resins.

[0067] The binder resin content in the toner is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 75% by mass or more, and preferably 97% by mass or less, more preferably 95% by mass or less, and even more preferably 93% by mass or less.

[0068] Yellow pigments have a specific amount of NH groups.

[0069] The amount of NH groups in the 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 13.0 mmol / g or less, and more preferably 10.0 mmol / g or less. Here, the amount of NH groups is the value obtained by dividing the total number of -NH- groups and -NH2 groups in one molecule by the molecular weight.

[0070] The yellow pigment is not particularly limited as long as it has the above-mentioned amount of NH groups, but from the viewpoint of image density, at least one selected from the group consisting of benzimidazolone pigment, isoindoline pigment, and condensed disazo pigment is preferred, and at least one selected from benzimidazolone pigment and isoindoline pigment is more preferred.

[0071] Examples of benzimidazolone pigments include CI Pigment Yellow 180 (total number of -NH- and -NH2 groups in one molecule = 6, molecular weight = 733, NH group amount = 8.2 mmol / g).

[0072] Examples of isoindoline pigments include CI Pigment Yellow 185 (total number of -NH- and -NH2 groups in one molecule = 4, molecular weight = 337, NH group amount = 11.9 mmol / g).

[0073] Examples of condensed disazo pigments include CI Pigment Yellow 93 (total number of -NH- and -NH2 groups in one molecule = 4, molecular weight = 937, NH group amount = 4.3 mmol / g) and CI Pigment Yellow 95 (total number of -NH- and -NH2 groups in one molecule = 4, molecular weight = 917, NH group amount = 4.4 mmol / g).

[0074] The yellow pigment content is preferably 3 parts by mass or more, more preferably 4 parts by mass or more, and even more preferably 5 parts by mass or more, based on 100 parts by mass of the total of the crystalline polyester resin and amorphous polyester resin, and from the viewpoint of low-temperature fixability, preferably 12 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 8 parts by mass or less.

[0075] The toner of the present invention may contain colorants other than the yellow pigment, as long as the effects of the present invention are not impaired. However, the content of the yellow pigment is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and 100% by mass or less, in the colorants. Other colorants include carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, and the like.

[0076] Hydroxyl group-containing amide compounds are given by formula (I): R 1 -CONH-X-NHCO-R 2 (I) (In the formula, R 1 and R 2Each of these is independently a hydroxyalkyl group having 12 to 22 carbon atoms, and X is a divalent hydrocarbon group having 2 to 12 carbon atoms. Or formula (II): R 3 -CONH-R 4 (II) (In the formula, R 3 R is a hydroxyalkyl group having 12 to 22 carbon atoms. 4 (This is a hydroxyalkyl group having 2 to 22 carbon atoms.) The compound is represented by [formula]. The toner of the present invention may contain either the compound represented by formula (I) or the compound represented by formula (II) as a hydroxyl group-containing amide compound, or it may contain both the compound represented by formula (I) and the compound represented by formula (II).

[0077] R 1 , R 2 and R 3 From the viewpoint of further improving the scratch resistance of the printed material, the number of carbon atoms in each hydroxyalkyl group is preferably 13 or more, more preferably 15 or more, and preferably 21 or less, more preferably 19 or less.

[0078] R 4 The number of carbon atoms in the hydroxyalkyl group is preferably 10 or less, more preferably 6 or less, from the viewpoint of further improving the scratch resistance of the printed material.

[0079] R 1 ~R 4 The alkyl group in this combination may be branched or linear, but it is preferably linear.

[0080] Examples of divalent hydrocarbon groups in X include divalent aliphatic hydrocarbon groups and divalent aromatic hydrocarbon groups.

[0081] Examples of divalent aliphatic hydrocarbon groups include ethylene, trimethylene, tetramethylene, and hexamethylene groups.

[0082] Examples of divalent aromatic hydrocarbon groups include phenylene groups, m-xylylene groups, and p-xylylene groups.

[0083] The number of carbon atoms in the divalent hydrocarbon group of X is preferably 10 or less, more preferably 8 or less, and even more preferably 6 or less.

[0084] Specific examples of hydroxyl group-containing amide compounds represented by formula (I) include 12-hydroxystearate ethylenebisamide, 12-hydroxystearate hexamethylenebisamide, 12-hydroxystearate xylylenebisamide, and 12-hydroxypalmitate ethylenebisamide.

[0085] Specific examples of hydroxyl group-containing amide compounds represented by formula (II) include hydroxyethyl 12-hydroxystearate and hydroxyethyl 12-hydroxypalmitate.

[0086] The melting point of the hydroxyl group-containing amide compound is preferably 100°C or higher, more preferably 110°C or higher, and even more preferably 120°C or higher, from the viewpoint of glossiness, and preferably 180°C or lower, more preferably 170°C or lower, and even more preferably 160°C or lower, from the viewpoint of low-temperature fixability.

[0087] The content of the hydroxyl group-containing amide compound is 0.4 parts by mass or more, preferably 0.5 parts by mass or more, more preferably 0.6 parts by mass or more, even more preferably 0.7 parts by mass or more, even more preferably 0.8 parts by mass or more, and 13 parts by mass or less, preferably 12 parts by mass or less, more preferably 7 parts by mass or less, even more preferably 4 parts by mass or less, and even more preferably 2 parts by mass or less, based on 100 parts by mass of the total amount of crystalline polyester resin and amorphous polyester resin.

[0088] Furthermore, the mass ratio of the hydroxyl group-containing amide compound to the yellow pigment (hydroxyl group-containing amide compound / yellow pigment) is preferably 5 / 95 or more, more preferably 10 / 90 or more, even more preferably 13 / 87 or more, and preferably 70 / 30 or less, more preferably 50 / 50 or less, even more preferably 30 / 70 or less, and even more preferably 20 / 80 or less.

[0089] The toner of the present invention may further contain additives such as release agents, charge control agents, magnetic powders, flowability enhancers, conductivity modifiers, reinforcing fillers such as fibrous materials, antioxidants, and cleaning properties enhancers.

[0090] Examples of mold release agents include hydrocarbon waxes and their oxides, such as polypropylene wax, polyethylene wax, ethylene propylene copolymer wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; ester waxes such as carnauba wax, montane wax and their deoxidizing waxes, and fatty acid ester waxes; and fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts, etc., which can be used individually or in combination of two or more.

[0091] 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 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 fixation.

[0092] The release agent content is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 1.5 parts by mass or more, and 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, per 100 parts by mass of binder resin, from the viewpoint of low-temperature fixation and offset resistance of the toner and dispersibility in the binder resin.

[0093] The charge control agent is not particularly limited and may contain either a positively charged charge control agent or a negatively charged charge control agent.

[0094] Positively charged 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," "Bontron N-11," and "Bontron N-79" (all manufactured by Orient Chemical Industries, Ltd.); triphenylmethane-based dyes containing tertiary amines as side chains; quaternary ammonium salt compounds, such as "Bontron P-51" (manufactured by Orient Chemical Industries, Ltd.), cetyltrimethylammonium bromide, and "COPY CHARGE PX." Examples include VP435 (manufactured by Clariant), polyamine resins such as AFP-B (manufactured by Orient Chemical Industries, Ltd.), imidazole derivatives such as PLZ-2001 and PLZ-8001 (both manufactured by Shikoku Chemicals, Ltd.), and styrene-acrylic resins such as FCA-701PT and FCA-201-PS (manufactured by Fujikura Chemicals, Ltd.).

[0095] Furthermore, as negative charge control agents, 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.), "Eisenspiron Black TRH," and "T-77" (manufactured by Hodogaya Chemical Co., Ltd.); metal compounds of benzyl acid compounds, such as "LR-147" and "LR-297" (both 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" Examples include VP434 (manufactured by Clariant), nitroimidazole derivatives, organometallic compounds, etc.

[0096] From the viewpoint of the charge 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 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, per 100 parts by mass of the binder resin.

[0097] The toner of the present invention may be obtained by any of the conventionally known methods, such as the melt-kneading method, the emulsification-coagulation method, or the suspension polymerization method, and may also be a toner having a core-shell structure. However, from the viewpoint of the mixability of the toner raw materials, pulverized toner is preferred, and pulverized toner obtained by the melt-kneading method, that is, pulverized toner obtained by a method including the steps of melt-kneading the raw materials and pulverizing the resulting mixture, is more preferred. Specifically, for example, a crystalline polyester resin, an amorphous polyester resin, a yellow pigment, and a hydroxyl group-containing amide compound, along with raw materials such as a mold release agent and a charge control agent as needed, can be uniformly mixed in a mixer such as a Henschel mixer, then melt-kneaded in a closed-type kneader, a single-screw or twin-screw extruder, an open-roll type kneader, etc., followed by cooling, pulverization, and classification. Furthermore, from the viewpoint of dispersibility of the hydroxyl group-containing amide compound, it is preferable to use the hydroxyl group-containing amide compound after mixing all or part of the amorphous polyester resin with it at a temperature above the melting point of the hydroxyl group-containing amide compound. It is even more preferable to add and mix the hydroxyl group-containing amide compound after the polycondensation reaction of the raw material monomers of the amorphous polyester resin at a temperature above the melting point of the hydroxyl group-containing amide compound.

[0098] In order to improve the transferability of the toner of the present invention, it is preferable to use external additives. Examples of external additives include inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide, and zinc oxide, and organic fine particles such as melamine resin fine particles and polytetrafluoroethylene resin fine particles, and two or more 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 treated to hydrophobicity is more preferable.

[0099] Examples of hydrophobic agents used to hydrophobize the surface of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), cyclic silazane, silicone oil, aminosilane, octyltriethoxysilane (OTES), and methyltriethoxysilane.

[0100] The average particle size of the external additive is preferably 5 nm or larger, more preferably 10 nm or larger, even more preferably 15 nm or larger, and preferably 250 nm or smaller, more preferably 200 nm or smaller, and even more preferably 90 nm or smaller, from the viewpoint of the toner's chargeability, fluidity, and transferability.

[0101] External additive treatment, which involves mixing toner particles with external additives, can be carried out according to conventional methods, and a mixer such as a Henschel mixer can be used.

[0102] From the viewpoint of the toner's electrostatic properties, fluidity, and transferability, the content of the external additive is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.3 parts by mass or more, and preferably 5 parts by mass or less, and more preferably 3 parts by mass or less, per 100 parts by mass of toner particles before treatment with the external additive.

[0103] The volume-intermediate particle size (D) of the toner of the present invention 50 The volume median particle size (D) is preferably 3 μm or more, more preferably 4 μm or more, and preferably 15 μm or less, more preferably 10 μm or less. 50 ) refers to the particle size at which the cumulative volume frequency calculated using volume fractions accounts for 50% when calculated from the smallest particle size. Furthermore, if 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.

[0104] The toner of the present invention can be used as is as a one-component developing toner, or as a two-component developing toner used in combination with a carrier, in image forming apparatuses using either a one-component developing method or a two-component developing method, respectively. [Examples]

[0105] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way by these examples. The physical properties of resins, etc., can be measured by the following methods.

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

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

[0108] [Glass transition temperature of resins] Using a differential scanning calorimeter "Q-100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.01 to 0.02 g of the sample is weighed into an aluminum pan and heated from room temperature (20°C) to 200°C at a heating rate of 10°C / min, and then cooled to 0°C at a cooling rate of 10°C / min. Next, the sample is heated at a heating rate of 10°C / min and the endothermic peak is measured. The temperature at the intersection of the extension of the baseline below the maximum endothermic peak temperature and the tangent line showing the maximum slope from the rising part of the peak to the peak apex is defined as the glass transition temperature.

[0109] [Weight-average molecular weight of resins] The molecular weight distribution is measured by gel permeation chromatography (GPC) using the following method, and the weight-average molecular weight is determined. (1) Preparation of sample solution The sample is dissolved in tetrahydrofuran (amorphous resin) or chloroform (crystalline resin) at 40°C to a concentration of 0.5 g / 100 mL. Then, this solution is filtered using a PTFE type membrane filter "DISMIC-25JP" (manufactured by ADVANTEC) with a pore size of 0.20 μm to remove insoluble components and obtain the sample solution. (2) Molecular weight measurement Using the measurement apparatus and analytical column described below, tetrahydrofuran (amorphous resin) or chloroform (crystalline resin) is flowed as the eluent at a flow rate of 1 mL / min, and the column is stabilized in a constant temperature bath at 40°C. 100 μL of the sample solution is then injected, and the measurement is performed. The molecular weight of the sample is calculated based on a calibration curve prepared in advance. The calibration curve used in this case includes several types of monodisperse polystyrene (A-500 (5.0 × 10) manufactured by Tosoh Corporation). 2 ), A-1000 (1.01 x 10 3 ), A-2500 (2.63 x 10 3 ), A-5000 (5.97 x 10 3 ), F-1 (1.02×10 4 ), F-2 (1.81×10 4 ), F-4 (3.97×10 4 ), F-10 (9.64×10 4 ), F-20 (1.90×10 5 ), F-40 (4.27×10 5 ), F-80 (7.06×10 5 ), F-128 (1.09×10 6 The sample prepared using )) as a standard sample is used. The value in parentheses indicates the molecular weight. Measuring device: HLC-8220GPC (manufactured by Tosoh Corporation) Analysis column: TSKgel GMH XL +TSKgel G3000H XL (Manufactured by Tosoh Corporation)

[0110] [Melting point of release agent] Using a differential scanning calorimeter "Q-100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.02 g of the sample is weighed into an aluminum pan, heated to 200°C, and then cooled from 200°C to 0°C at a rate of 10°C / min. Next, the sample is heated at a rate of 10°C / min and the heat quantity is measured, with the maximum endothermic peak temperature being defined as the melting point.

[0111] [Average particle size of external additives] The average particle diameter refers to the number-average particle diameter, which is calculated by measuring the particle size (average of the major and minor axes) of 500 particles from scanning electron microscope (SEM) images and using the number-average value of these measurements.

[0112] [Toner volume medium particle size (D 50 )〕 • Measuring instrument: "Coulter Multisizer (Registered Trademark) III" (manufactured by Beckman Coulter, Inc.) • Aperture diameter: 50 μm • Analysis software: "Multisizer (registered trademark) III version 3.51" (manufactured by Beckman Coulter, Inc.) • Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) • Dispersion: Prepared by dissolving polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" [manufactured by Kao Corporation, HLB (Griffin) = 13.6] in the electrolyte to adjust the concentration to 5% by mass. • Dispersion conditions: Add 10 mg of the sample to 5 mL of the dispersion and disperse for 1 minute using an ultrasonic disperser (machine name: US-1 manufactured by SND Corporation, output: 80W). Then, add 25 mL of electrolyte and disperse for another minute using the ultrasonic disperser to prepare the sample dispersion. • Measurement conditions: The sample dispersion is added to 100 mL of the electrolyte to adjust the concentration so that the particle size of 30,000 particles can be measured in 20 seconds. Then, the 30,000 particles are measured, and the volume median particle size (D) is determined from the particle size distribution. 50 )

[0113] Resin manufacturing example 1 The alcohol components, carboxylic acid components other than adipic acid, esterification catalyst, and co-catalyst shown in Tables 1 and 2 were placed in a 10-liter four-necked flask equipped with a thermometer, stainless steel stirring rod, dehydration tube, condenser, and nitrogen inlet tube, and heated to 235°C over 2 hours in a mantle heater under a nitrogen atmosphere. After confirming that the reaction rate reached over 95% at 235°C, the mixture was cooled to 180°C, adipic acid was added, and the mixture was heated to 220°C over 2 hours. After reacting at 220°C for 1 hour, the reaction was carried out at 8 kPa until the softening point shown in Tables 1 and 2 was reached to obtain amorphous polyester resins (resins A1-A6, A8-A12). The mixture was then cooled to 180°C, the amide compounds shown in Tables 1 and 2 were added, and the mixture was melt-mixed at 180°C for 30 minutes to obtain mixtures of resin and amide compounds (mixtures 1-6, 8-12). The physical properties of the resins measured by taking a sample of the obtained resins are shown in Tables 1 and 2. In this specification, the reaction rate refers to the value of (mol) of reacted water produced / (mol) of theoretically produced water produced × 100.

[0114] Resin manufacturing example 2 The alcohol component, carboxylic acid components other than dodecenyl succinic anhydride, esterification catalyst, and co-catalyst shown in Table 1 were placed in a 10-liter four-necked flask equipped with a thermometer, stainless steel stirring rod, dehydration tube, condenser, and nitrogen inlet tube, and heated to 235°C over 2 hours in a mantle heater under a nitrogen atmosphere. After confirming that the reaction rate reached over 95% at 235°C, the mixture was cooled to 180°C, dodecenyl succinic anhydride was added, and the mixture was heated to 220°C over 2 hours. After reacting at 220°C for 1 hour, the reaction was carried out at 8 kPa until the softening point shown in Table 1 was reached to obtain amorphous polyester resin (resin A7). After cooling to 180°C, the amide compound shown in Table 1 was added, and the mixture was melt-mixed at 180°C for 30 minutes to obtain a mixture of resin and amide compound (mixture 7). The physical properties of the resin, measured by taking a sample of the obtained resin, are shown in Table 1.

[0115] Resin manufacturing example 3 The alcohol component, carboxylic acid components other than adipic acid and trimellitic anhydride, esterification catalyst, and co-catalyst shown in Table 2 were placed in a 10-liter four-necked flask equipped with a thermometer, stainless steel stirring rod, dehydration tube, condenser, and nitrogen inlet tube, and heated to 235°C over 2 hours in a mantle heater under a nitrogen atmosphere. After confirming that the reaction rate reached 95% or more at 235°C, the mixture was cooled to 180°C, and then adipic acid and trimellitic anhydride were added. The mixture was then heated to 220°C over 2 hours. After reacting at 220°C for 1 hour, the reaction was continued at 8 kPa until the softening point shown in Table 2 was reached, yielding an amorphous polyester resin (resin A13). The physical properties of the obtained resin are shown in Table 2.

[0116] Details of the amide compounds used are as follows: 12-Hydroxystearate ethylenebisamide: ITOHWAX J-530 (manufactured by Ito Oil Co., Ltd.), melting point 142℃ 12-Hexamethylenebisamide hydroxystearate: ITOHWAX J-630 (manufactured by Ito Oil Co., Ltd.), melting point 135℃ 12-Hydroxystearate xylylenebisamide: ITOHWAX J-700 (manufactured by Ito Oil Co., Ltd.), melting point 125℃ 12-Hydroxyethyl hydroxystearate: ITOHWAX J-420 (manufactured by Ito Oil Co., Ltd.), melting point 105℃ Ethylenebisamide stearate: Kao Wax EB-P (manufactured by Kao Corporation), melting point 143℃

[0117] [Table 1]

[0118] [Table 2]

[0119] Resin manufacturing example 4 The alcohol and carboxylic acid components shown in Table 3 were placed in a 10-liter four-necked flask equipped with a thermometer, stainless steel stirring rod, dehydration tube, condenser, and nitrogen inlet tube. The mixture was then kept at 140°C for 1 hour in a mantle heater under a nitrogen atmosphere, followed by a 10°C / h increase in temperature from 140°C to 200°C. A polycondensation reaction was then carried out at 200°C for 1 hour. Finally, the esterification catalyst shown in Table 3 was added, and the reaction was carried out at 200°C and 8 kPa until the softening point indicated in Table 3 was reached to obtain crystalline polyester resins (resins C1-C6).

[0120] [Table 3]

[0121] Examples 1-4, 6-15, Comparative Examples 1-3 The mixture and resin shown in Table 4 were thoroughly mixed in a Henschel mixer. This mixture consisted of 100 parts by mass of the negative charge control agent "Bontron E-81" (manufactured by Orient Chemical Industry Co., Ltd.), 5 parts by mass of the coloring agent "Toner Yellow HG" (manufactured by Heubach Color Japan Co., Ltd., CI Pigment Yellow 180 (PY180), molecular weight: 733, number of NH groups per molecule: 6), and 2 parts by mass of the release agent "HNP-9" (manufactured by Nippon Seiro Co., Ltd., paraffin wax, melting point: 75°C). The mixture was then melt-kneaded using a co-rotating twin-screw extruder with a total length of 1560 mm, a screw diameter of 42 mm, and a barrel inner diameter of 43 mm, at a roll rotation speed of 200 r / min and a heating temperature of 100°C inside the rolls. The mixture was fed at a rate of 20 kg / h, and the average residence time was approximately 18 seconds. The resulting mixture is cooled, coarsely ground, then ground in a jet mill, and classified to obtain the medium volume particle size (D 50 ) yielded toner particles with a diameter of 8 μm.

[0122] To 100 parts by mass of the obtained toner particles, 1 part by mass of hydrophobic silica "AEROSIL NAX 50" (manufactured by Nippon Aerosil Co., Ltd., hydrophobic treatment agent: HMDS, average particle size: approximately 30 nm) was added as an external additive and mixed in a Henschel mixer to obtain yellow toner.

[0123] Example 5 A yellow toner was obtained in the same manner as in Example 1, except that 5 parts by mass of "Pariotol Yellow D1155" (manufactured by Sun Chemical Co., Ltd., CI Pigment Yellow 185 (PY185), molecular weight: 337, number of NH groups per molecule: 4) was used as a coloring agent instead of "Toner Yellow HG".

[0124] Comparative Example 4 A yellow toner was obtained in the same manner as in Example 1, except that 5 parts by mass of "Toner Yellow 3GP-CT" (manufactured by Heubach Color Japan Co., Ltd., CI Pigment Yellow 155 (PY155), molecular weight: 717, number of NH groups per molecule: 2) was used as a coloring agent instead of "Toner Yellow HG".

[0125] Test example [Abrasion resistance of printed materials] Toner was installed in a Sharp AR-505 copier (product name, manufactured by Sharp Corporation), and a solid image was removed before passing through the fuser to obtain a printed copy in an unfixed state (print area: 2cm x 12cm, toner adhesion: 0.5mg / cm²). 2 Furthermore, the unfixed image was printed twice on top of the unfixed image, with an adhesion amount of 1.5 mg / cm². 2 The unfixed image obtained in this way was fixed at 150°C and 300 mm / s to obtain a printed material. A stainless steel weight measuring 3 cm vertically, 3 cm horizontally, and 6.5 cm high, weighing 500 g, was placed on the resulting printout and moved back and forth at a speed of 0.5 m / s over a width of 12 cm on the fixed image plus 2 cm on both ends, for a total width of 16 cm. One back-and-forth motion was counted as one cycle. The number of times a black band of toner deposits appeared on the non-printed area was visually confirmed to evaluate abrasion resistance. The results are shown in Table 5. A higher number of cycles indicates better abrasion resistance.

[0126] [Table 4]

[0127] [Table 5]

[0128] From the above results, it can be seen that the toners of Examples 1 to 15 produce images with superior scratch resistance compared to the toners of Comparative Example 1, which contains an amide compound without a hydroxyl group; Comparative Examples 2 and 3, which do not contain a predetermined amount of a hydroxyl group-containing amide compound; and Comparative Example 4, which contains a yellow pigment with a lower-than-determined amount of NH groups. [Industrial applicability]

[0129] The electrostatic image developing toner of the present invention is suitably used for developing latent images formed in electrostatic image developing methods, electrostatic recording methods, electrostatic printing methods, and the like.

Claims

1. A toner for developing electrostatic images, comprising a crystalline polyester resin, an amorphous polyester resin, a yellow pigment, and a hydroxyl group-containing amide compound, wherein the NH group content of the yellow pigment is 4.0 mmol / g or more and 15.0 mmol / g or less, and the hydroxyl group-containing amide compound is of formula (I): R １ -CONH-X-NHCO-R ２ (I) (In the formula, R １ and R ２ Each of these is independently a hydroxyalkyl group having 12 to 22 carbon atoms, and X is a divalent hydrocarbon group having 2 to 12 carbon atoms. Or formula (II): R ３ -.ONH-R ４ (-I) (In the formula, R ３ R is a hydroxyalkyl group having 12 to 22 carbon atoms. ４ (This is a hydroxyalkyl group having 2 to 22 carbon atoms.) A toner for developing electrostatic images, wherein the compound represented by [formula] is such that the content of the hydroxyl group-containing amide compound is 0.4 parts by mass or more and 13 parts by mass or less, based on 100 parts by mass of the total amount of the crystalline polyester resin and the amorphous polyester resin.

2. The toner for developing electrostatic images according to claim 1, wherein the alcohol component of the crystalline polyester resin contains ethylene glycol.

3. The electrostatic image developing toner according to claim 1 or 2, wherein the carboxylic acid component of the crystalline polyester resin contains an aliphatic monocarboxylic acid compound having 12 to 30 carbon atoms.

4. Amorphous polyester resin, formula (III): 【Chemistry 1】 (wherein, OR ５ and R ５ O is an oxyalkylene group, R ５ is an ethylene group and / or a propylene group, x and y represent the average number of moles of alkylene oxide added, each being a positive number, and the value of the sum of x and y is 1 or more and 16 or less) The electrostatic image developing toner according to claim 1 or 2, comprising an amorphous polyester resin which is a polycondensate of an alcohol component and a carboxylic acid component, the alcohol component containing an alkylene oxide adduct of bisphenol A represented by [formula].

5. The electrostatic image developing toner according to claim 1 or 2, wherein the content of the yellow pigment is 3 parts by mass or more and 12 parts by mass or less based on 100 parts by mass of the total amount of crystalline polyester resin and amorphous polyester resin.

Images