Toner for electrostatic charge image development

Abstract

To provide toner for electrostatic charge image development including pigments having favorable color developability and having image scratch resistance, and manufacturing method of the toner.SOLUTION: Toner for electrostatic charge image development includes a binder resin, ester compositions (E) and a colorant. The ester compositions (E) are one or more types selected from: an ester composition (E1) containing a condensate of a carboxylic acid component (E1-ac) containing an aliphatic monocarboxylic acid compound with 10 or more and 30 or less carbon atoms, and an alcohol component (E1-al) containing a dihydric or higher aliphatic alcohol with 2 or more and 14 or less carbon atoms; and an ester composition (E2) containing a condensate of an alcohol component (E2-al) containing an aliphatic monoalcohol with 10 or more and 30 or less carbon atoms, and a carboxylic acid component (E2-ac) containing divalent or higher aliphatic carboxylic acid compound with 2 or more and 14 or less carbon atoms, where a sum of the acid value and hydroxyl value of the ester compositions (E) is 70 mgKOH / g or more and 400 mgKOH or less. A manufacturing method of the toner for electrostatic charge image development is also provided.SELECTED DRAWING: None

Description

[Technical field]

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

[0002] In recent years, the market has been shifting from office printing to commercial printing, resulting in a demand for higher resolution and reliability than ever before in printed materials.

[0003] For example, Patent Document 1 describes a toner for developing electrostatic images, which comprises a colorant, a resin composition obtained by condensing an amorphous polyester resin (A) having an acid group with an amine compound, and either an ester composition containing a condensate of a carboxylic acid component (CI-ac) containing 20 mol % or more of an aliphatic monocarboxylic acid compound having 10 to 30 carbon atoms and an alcohol component (CI-al) containing 90 mol % or more of a divalent or higher aliphatic alcohol having 2 to 14 carbon atoms, or an ester composition containing a condensate of an alcohol component (CII-al) containing 20 mol % or more of an aliphatic monoalcohol having 10 to 30 carbon atoms and a carboxylic acid component (CII-ac) containing 90 mol % or more of a divalent or higher aliphatic carboxylic acid compound having 2 to 14 carbon atoms, or both of them. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Patent Publication No. 2021-47403 Summary of the Invention [Problem to be solved by the invention]

[0005] However, in the toner using the ester composition described in Patent Document 1, while the image density of the printed matter is improved, it has been found that the ester composition has a low SP value and a low molecular weight, and therefore localizes on the surface of the printed image, significantly reducing the strength of the image. Furthermore, it has been found that the low SP value of the ester composition results in insufficient dispersion of pigments containing many hydrophilic groups, such as yellow pigments and magenta pigments, and as a result, sufficient image density cannot be obtained.

[0006] The present invention relates to a toner for developing electrostatic images, which has good pigment color development and good image abrasion resistance, and a method for producing the same. [Means for solving the problem]

[0007] The present invention relates to [1] A toner for developing electrostatic images, comprising a binder resin, an ester composition (E), and a colorant, wherein the ester composition (E) is An ester composition (E1) containing a condensate of a carboxylic acid component (E1-ac) containing 55 mol % or more of an aliphatic monocarboxylic acid compound having 10 to 30 carbon atoms and an alcohol component (E1-al) containing 80 mol % or more of a dihydric or higher aliphatic alcohol having 2 to 14 carbon atoms; and An ester composition (E2) containing a condensate of an alcohol component (E2-al) containing 55 mol% or more of an aliphatic monoalcohol having 10 to 30 carbon atoms and a carboxylic acid component (E2-ac) containing 80 mol% or more of a divalent or higher aliphatic carboxylic acid compound having 2 to 14 carbon atoms. One or more selected from a toner for developing an electrostatic image, the sum of the acid value and the hydroxyl value of the ester composition (E) being 70 mgKOH / g or more and 400 mgKOH or less; [2] A method for producing the toner for developing electrostatic images according to the above [1], comprising the steps of melt-kneading a mixture containing a binder resin, an ester composition (E) and a colorant to obtain a melt-kneaded product, and pulverizing and classifying the melt-kneaded product to obtain toner particles. Regarding. Effect of the Invention

[0008] According to the present invention, it is possible to provide a toner for developing electrostatic images, which has good pigment color development and also has good scratch resistance for the image. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] The toner for developing electrostatic images of the present invention (hereinafter, also simply referred to as "the toner of the present invention") is a toner for developing electrostatic images containing a binder resin, an ester composition (E), and a colorant, and is significantly characterized in that the ester composition (E) is one or more selected from an ester composition (E1) containing a condensate of a carboxylic acid component mainly composed of an aliphatic monocarboxylic acid compound having a predetermined carbon number and an alcohol component mainly composed of an aliphatic alcohol having a predetermined carbon number of two or more hydric components and / or an ester composition (E2) containing a condensate of an alcohol component mainly composed of an aliphatic monoalcohol having a predetermined carbon number and a carboxylic acid component mainly composed of an aliphatic carboxylic acid compound having a predetermined carbon number of two or more hydric components, and has an acid value and a hydroxyl value in a predetermined range. According to the toner of the present invention, the color development of yellow and magenta pigments is good, and printed matter having good image abrasion resistance can be obtained.

[0010] Although the details of why the present invention has an effect are not clear, it is believed to be as follows. The toner of the present invention contains an ester composition (E) containing a long-chain monoalcohol or monocarboxylic acid in the molecular chain. This ester composition (E) has a high affinity with the hydrophobic surface of the colorant, and contributes to the dispersion of the colorant as a wetting agent for the colorant. In addition, the ester composition (E) has a predetermined amount of carboxylic acid terminals or hydroxyl terminals, or both, and therefore has good affinity with the hydrophilic surface of the pigment, and shows very high pigment dispersibility compared to conventional ester compositions. In addition, it is presumed that having a predetermined amount of carboxylic acid terminals or hydroxyl terminals, or both, also contributes to dispersion stabilization in the binder resin, suppresses localization on the image surface during heating, and suppresses deterioration of image abrasion resistance.

[0011] In the present invention, the binder resin is not particularly limited as long as it is a resin used as a binder resin for toner, and examples thereof include polyester resin, vinyl resin such as styrene-acrylic resin, epoxy resin, polycarbonate, polyurethane, and composite resin containing two or more of these resins, but in the present invention, from the viewpoint of fixability, it is preferable to contain a polyester resin such as a polyester resin or a composite resin having a polyester resin and a styrene resin. The polyester resin is preferably amorphous, and the amorphous polyester resin is preferably an amorphous polyester resin.

[0012] The crystallinity of a resin is represented by a crystallinity index defined as the ratio of the softening point to the maximum endothermic peak temperature measured by a differential scanning calorimeter, that is, the value of [softening point / maximum endothermic peak temperature]. The crystalline resin is a resin having a crystallinity index of 0.6 or more, preferably 0.7 or more, more preferably 0.9 or more, and 1.4 or less, preferably 1.2 or less, more preferably 1.1 or less. On the other hand, an amorphous resin is a resin in which no endothermic peak is observed, or if an endothermic peak is observed, the crystallinity index is greater than 1.4, preferably greater than 1.5, more preferably 1.6 or more, or less than 0.6, preferably 0.5 or less. The crystallinity of the resin can be adjusted by the type and ratio of the raw material monomers, and the 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. In the case of a crystalline resin, the maximum endothermic peak temperature is the melting point.

[0013] The amorphous polyester resin is preferably a polycondensation product of an alcohol component, including an alkylene oxide adduct of bisphenol A, and a carboxylic acid component.

[0014] The alkylene oxide adduct of bisphenol A has the formula (I):

[0015] [ka]

[0016] (In the formula, OR and RO are oxyalkylene groups, R is an ethylene group and / or a propylene group, x and y are the average number of moles of alkylene oxide added, each of which is 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.) Examples of the compound include an ethylene oxide adduct of bisphenol A and a propylene oxide adduct of bisphenol A.

[0017] The content of the alkylene oxide adduct of bisphenol A represented by formula (I) in the alcohol component is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, still more preferably 95 mol% or more, and is 100 mol% or less, and particularly preferably 100 mol%.

[0018] Examples of other alcohol components include aliphatic diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-butenediol, 1,3-butanediol, and neopentyl glycol; and trihydric or higher alcohols such as bisphenol A, hydrogenated bisphenol A, and glycerin.

[0019] Examples of the carboxylic acid component include aromatic dicarboxylic acids, aliphatic dicarboxylic acids, tri- or higher carboxylic acids, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0020] Examples of the aromatic dicarboxylic acid compound include phthalic acid, isophthalic acid, terephthalic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms. Of these, terephthalic acid is preferred.

[0021] Examples of the aliphatic dicarboxylic acid compound include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid which may be substituted with a hydrocarbon group having 1 to 20 carbon atoms, adipic acid, anhydrides of these acids, and alkyl esters of these acids in which the alkyl group has 1 to 3 carbon atoms.

[0022] Examples of the trivalent or higher carboxylic acid compound include trivalent or higher carboxylic acid compounds such as 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, and pyromellitic acid, anhydrides of these acids, and alkyl esters of these acids having an alkyl group with 1 to 3 carbon atoms.

[0023] In this specification, macromonomers and hydroxycarboxylic acids are not included in the alcohol component and the carboxylic acid component.

[0024] Furthermore, the alcohol component may appropriately contain a monohydric alcohol, and the carboxylic acid component may appropriately contain a monovalent carboxylic acid compound.

[0025] The equivalent ratio of the carboxy group of the carboxylic acid component to the hydroxyl group of the alcohol component (COOH group / OH group) is preferably 0.6 or more, more preferably 0.7 or more, even more preferably 0.75 or more, and is preferably 1.2 or less, more preferably 1.15 or less.

[0026] The amorphous polyester resin can be produced, for example, by polycondensing the raw material monomers, that is, an alcohol component and a carboxylic acid component, in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and further, if necessary, in the presence of an esterification promoter, a polymerization inhibitor, etc., at a temperature of preferably 160°C or higher, more preferably 200°C or higher, and preferably 250°C or lower, more preferably 240°C or lower.

[0027] Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and tin(II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropylate bistriethanolamine, and tin compounds are preferred. 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, more preferably 1 part by mass or less, relative to 100 parts by mass of the raw material monomer. Examples of the esterification promoter include gallic acid, etc. The amount of the esterification 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, more preferably 0.1 parts by mass or less, relative to 100 parts by mass of the raw material monomer. Examples of the polymerization inhibitor include tert-butylcatechol, etc. The amount of the 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, more preferably 0.1 parts by mass or less, relative to 100 parts by mass of the raw material monomer.

[0028] In the present invention, the amorphous polyester resin may be modified to such an extent that its properties are not substantially impaired. Examples of the modified amorphous polyester resin include amorphous polyester resins grafted or blocked with phenol, urethane, epoxy, or the like by the methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636, and the like.

[0029] The softening point of the amorphous polyester resin is preferably 90° C. or higher, more preferably 100° C. or higher, from the viewpoint of durability, and is preferably 150° C. or lower, more preferably 140° C. or lower, from the viewpoint of low-temperature fixability.

[0030] From the viewpoint of low-temperature fixing property and fixing width, the amorphous polyester resin 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 50° C. or less, and even more preferably 40° C. or less.

[0031] The softening point of the amorphous resin having the 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 180°C or lower, more preferably 160°C or lower, and even more preferably 140°C or lower, from the viewpoint of low-temperature fixing ability.

[0032] Furthermore, the softening point of the amorphous resin having the 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 durability, and is preferably 130°C or lower, more preferably 125°C or lower, and even more preferably 120°C or lower from the viewpoint of low-temperature fixability.

[0033] 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 70 / 30 or less.

[0034] From the viewpoint of durability, the glass transition temperature of the amorphous polyester resin is preferably 40° C. or higher, more preferably 50° C. or higher, and from the viewpoint of low-temperature fixability, it is preferably 80° C. or lower, more preferably 70° C. or lower, and even more preferably 65° C. or lower. When the amorphous polyester resin is composed of two or more resins, it is preferable that the weighted average value is within the above range.

[0035] The acid value of the amorphous polyester resin is preferably 1 mgKOH / g or more, more preferably 3 mgKOH / g or more, from the viewpoint of low temperature fixability, and is preferably 20 mgKOH / g or less, more preferably 15 mgKOH / g or less, from the viewpoint of durability. When the amorphous polyester resin is composed of two or more resins, it is preferable that the weighted average value is within the above range.

[0036] The content of the 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, still more preferably 95% by mass or more, and is 100% by mass or less, and particularly preferably 100% by mass.

[0037] The ester composition (E) is at least one selected from ester compositions (E1) and (E2), and the ester composition (E1) contains a condensate of a carboxylic acid component (E1-ac) containing 55 mol % or more of an aliphatic monocarboxylic acid compound having from 10 to 30 carbon atoms and an alcohol component (E1-al) containing 80 mol % or more of a dihydric or higher aliphatic alcohol having from 2 to 14 carbon atoms. In the present invention, from the viewpoint of storage stability, the ester composition (E1) is preferred, and from the viewpoint of fixability, the ester composition (E2) is preferred.

[0038] From the viewpoint of further improving image density and gloss, the carbon number of the aliphatic monocarboxylic acid compound is 10 or more, preferably 12 or more, more preferably 14 or more, and even more preferably 16 or more, and from the viewpoint of low-temperature fixability, it is 30 or less, preferably 28 or less, more preferably 26 or less, even more preferably 24 or less, even more preferably 22 or less, and even more preferably 20 or less. When the aliphatic monocarboxylic acid compound is an alkyl ester of an aliphatic monocarboxylic acid, the carbon number of the alkyl ester moiety is not included in the above carbon number.

[0039] The aliphatic monocarboxylic acid compound may be either a saturated aliphatic monocarboxylic acid compound or an unsaturated aliphatic monocarboxylic acid compound. From the viewpoint of further improving image density and gloss, however, a saturated aliphatic monocarboxylic acid compound is preferred.

[0040] Examples of the saturated aliphatic monocarboxylic acid compound include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, and montanic acid. Among these, stearic acid or palmitic acid is preferred from the viewpoint of low-temperature fixing ability and further improving image density and gloss.

[0041] The carboxylic acid component (E1-ac) may contain other carboxylic acid compounds other than the aliphatic monocarboxylic acid compounds. Examples of the other carboxylic acid compounds include linear or branched aliphatic dicarboxylic acid compounds, aromatic dicarboxylic acid compounds, alicyclic dicarboxylic acid compounds, and trivalent or higher carboxylic acid compounds.

[0042] From the viewpoint of further improving image density and gloss, the content of the aliphatic monocarboxylic acid compound in the carboxylic acid component (E1-ac) is 55 mol% or more, preferably 60 mol% or more, more preferably 75 mol% or more, even more preferably 85 mol% or more, still more preferably 95 mol% or more, and is 100 mol% or less, particularly preferably 100 mol%.

[0043] The carbon number of the dihydric or higher aliphatic alcohol is 2 or more, and preferably 3 or more, from the viewpoint of image density and gloss, and is 14 or less, preferably 12 or less, and more preferably 10 or less, from the viewpoint of low-temperature fixability.

[0044] Examples of the dihydric or higher aliphatic alcohol include linear or branched aliphatic diols and trihydric or higher aliphatic alcohols.

[0045] The linear or branched aliphatic diol may be either a saturated aliphatic diol or an unsaturated aliphatic diol, but from the viewpoint of further improving image density and gloss, a saturated aliphatic diol is preferred.

[0046] Examples of the saturated aliphatic diol include ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,10-decanediol, 1,12-dodecanediol, and 1,14-tetradecanediol.

[0047] Examples of the trihydric or higher aliphatic alcohol include glycerin, pentaerythritol, trimethylolpropane, and sorbitol, and among these, glycerin is preferred.

[0048] Of the dihydric or higher aliphatic alcohols, trihydric or higher aliphatic alcohols are preferred from the viewpoint of pigment dispersibility.

[0049] The alcohol component (E1-al) may contain alcohols other than the dihydric or higher aliphatic alcohols. Examples of the other alcohols include monoalcohols, aromatic diols, alicyclic diols, and trihydric or higher aromatic alcohols.

[0050] From the viewpoint of further improving image density and gloss, the content of the dihydric or higher aliphatic alcohol in the alcohol component (E1-al) is 80 mol% or more, preferably 90 mol% or more, more preferably 95 mol% or more, and 100 mol% or less, and particularly preferably 100 mol%.

[0051] The equivalent ratio (COOH group / OH group) of the carboxy group of the carboxylic acid component (E1-ac) to the hydroxyl group of the alcohol component (E1-al) is preferably 0.1 or more, more preferably 0.2 or more, even more preferably 0.3 or more, and is preferably 2 or less, more preferably 1 or less, even more preferably 0.7 or less.

[0052] The ester composition (E1) preferably contains a condensate of an aliphatic monocarboxylic acid compound having 10 to 30 carbon atoms and a divalent or higher aliphatic alcohol having 2 to 14 carbon atoms, more preferably a condensate of an aliphatic monocarboxylic acid compound having 12 to 26 carbon atoms and a divalent or higher aliphatic alcohol having 2 to 10 carbon atoms, and even more preferably a condensate of an aliphatic monocarboxylic acid compound having 14 to 22 carbon atoms and a divalent or higher aliphatic alcohol having 2 to 4 carbon atoms.

[0053] The ester composition (E2) contains a condensate of an alcohol component (E2-al) containing 55 mol% or more of an aliphatic monoalcohol having 10 to 30 carbon atoms and a carboxylic acid component (E2-ac) containing 80 mol% or more of a divalent or higher aliphatic carboxylic acid compound having 2 to 14 carbon atoms.

[0054] From the viewpoint of further improving image density and gloss, the carbon number of the aliphatic monoalcohol is 10 or more, preferably 12 or more, more preferably 14 or more, even more preferably 16 or more, and even more preferably 18 or more, and from the viewpoint of low-temperature fixability, the carbon number is 30 or less, preferably 28 or less, more preferably 26 or less, even more preferably 24 or less, and even more preferably 22 or less.

[0055] The aliphatic monoalcohol may be either a saturated aliphatic monoalcohol or an unsaturated aliphatic monoalcohol. From the viewpoint of further improving image density and gloss, the saturated aliphatic monoalcohol is preferred.

[0056] Examples of the aliphatic monoalcohol include capric alcohol, lauryl alcohol, stearyl alcohol, palmityl alcohol, behenyl alcohol, etc. Among these, stearyl alcohol or behenyl alcohol is preferred, and stearyl alcohol is more preferred.

[0057] The alcohol component (E2-al) may contain alcohols other than aliphatic monoalcohols. Examples of the other alcohols include linear or branched aliphatic diols, alicyclic diols, and trihydric or higher alcohols.

[0058] From the viewpoint of further improving image density and gloss, the content of the aliphatic monoalcohol in the alcohol component (E2-al) is 55 mol% or more, preferably 60 mol% or more, more preferably 75 mol% or more, even more preferably 85 mol% or more, still more preferably 95 mol% or more, and is 100 mol% or less, particularly preferably 100 mol%.

[0059] Examples of the divalent or higher aliphatic carboxylic acid compound include linear or branched aliphatic dicarboxylic acid compounds and trivalent or higher aliphatic carboxylic acid compounds.

[0060] The number of carbon atoms in the divalent or higher aliphatic carboxylic acid compound is, from the viewpoint of further improving image density and gloss, 2 or more, preferably 4 or more, more preferably 6 or more, and from the viewpoint of low-temperature fixability, 14 or less, preferably 12 or less. When the divalent or higher aliphatic carboxylic acid compound is an alkyl ester of an aliphatic carboxylic acid, the number of carbon atoms in the alkyl ester moiety is not included in the above carbon number.

[0061] The aliphatic dicarboxylic acid compound may be either a saturated aliphatic dicarboxylic acid compound or an unsaturated aliphatic dicarboxylic acid compound.

[0062] Examples of the aliphatic dicarboxylic acid compound include succinic acid, fumaric acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, anhydrides of these acids, and alkyl esters of these acids having an alkyl group with 1 to 3 carbon atoms. Of these, sebacic acid is preferred.

[0063] Examples of the trivalent or higher aliphatic carboxylic acid compound include aconitic acid, anhydrides of these acids, and alkyl esters of these acids having an alkyl group with 1 to 3 carbon atoms.

[0064] As the divalent or higher aliphatic carboxylic acid compound, from the viewpoint of low-temperature fixability and further improving image density and gloss, a saturated aliphatic dicarboxylic acid compound is preferable, and sebacic acid is more preferable.

[0065] The carboxylic acid component (E2-ac) may contain a carboxylic acid compound other than a divalent or higher aliphatic carboxylic acid compound. Examples of the other carboxylic acid compound include a monocarboxylic acid compound, an aromatic dicarboxylic acid compound, an alicyclic dicarboxylic acid compound, and a trivalent or higher aromatic carboxylic acid compound.

[0066] From the viewpoint of further improving image density and gloss, the content of the divalent or higher aliphatic carboxylic acid compound in the carboxylic acid component (E2-ac) is 80 mol % or more, preferably 90 mol % or more, more preferably 95 mol % or more, and 100 mol % or less, and particularly preferably 100 mol %.

[0067] The equivalent ratio (COOH group / OH group) of the carboxy group of the carboxylic acid component (E2-ac) to the hydroxyl group of the alcohol component (E2-al) is preferably 1 or more, more preferably 1.2 or more, even more preferably 1.4 or more, and is preferably 10 or less, more preferably 5 or less, even more preferably 3.3 or less.

[0068] The ester composition (E2) preferably contains a condensate of an aliphatic monoalcohol having from 10 to 30 carbon atoms and a divalent or higher aliphatic carboxylic acid compound having from 2 to 14 carbon atoms, more preferably a condensate of an aliphatic monoalcohol having from 12 to 26 carbon atoms and a divalent or higher aliphatic carboxylic acid compound having from 2 to 12 carbon atoms, and even more preferably a condensate of an aliphatic monoalcohol having from 18 to 22 carbon atoms and a divalent or higher aliphatic carboxylic acid compound having from 2 to 10 carbon atoms.

[0069] The ester composition (E) can be produced by condensing raw material monomers containing an alcohol component and a carboxylic acid component. For example, the ester composition (E1) can be produced by condensing raw material monomers containing an alcohol component (E1-al) and a carboxylic acid component (E1-ac) in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and further, if necessary, in the presence of an esterification promoter, 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. The ester composition (E2) can be produced using raw material monomers containing an alcohol component (E2-al) and a carboxylic acid component (E2-ac) in the same manner as the ester composition (E1).

[0070] The esterification catalyst, esterification promoter, and polymerization inhibitor used in the production of the ester composition (E1) and the ester composition (E2) are the same as those used in the production of the amorphous polyester resin. In the production of the ester composition (E1) and the ester composition (E2), the amount of the esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.05 parts by mass or more, and preferably 1 part by mass or less, more preferably 0.5 parts by mass or less, relative to 100 parts by mass of the raw material monomer. The amount of the esterification 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, more preferably 0.1 parts by mass or less, relative to 100 parts by mass of the raw material monomer. The amount of the 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, more preferably 0.1 parts by mass or less, relative to 100 parts by mass of the raw material monomer.

[0071] The sum of the acid value and the hydroxyl value of the ester composition (E) is, from the viewpoint of pigment dispersibility, 70 mgKOH / g or more, preferably 80 mgKOH / g or more, more preferably 90 mgKOH / g or more, and even more preferably 95 mgKOH / g or more, and from the viewpoint of storage stability, it is 400 mgKOH or less, preferably 380 mgKOH / g or less, more preferably 350 mgKOH / g or less, and even more preferably 320 mgKOH / g or less.

[0072] From the viewpoint of storage stability, the acid value of the ester composition (E1) is preferably 0.1 mgKOH / g or more, more preferably 0.5 mgKOH / g or more, and preferably 40 mgKOH / g or less, more preferably 20 mgKOH / g or less, and even more preferably 5 mgKOH / g or less.

[0073] The hydroxyl value of the ester composition (E1) is, from the viewpoint of pigment dispersibility, preferably 30 mgKOH / g or more, more preferably 70 mgKOH / g or more, even more preferably 80 mgKOH / g or more, and even more preferably 90 mgKOH / g or more, and from the viewpoint of storage stability, preferably 400 mgKOH or less, more preferably 360 mgKOH / g or less, and even more preferably 320 mgKOH / g or less.

[0074] The acid value of the ester composition (E2) is, from the viewpoint of pigment dispersibility, preferably 80 mgKOH / g or more, more preferably 90 mgKOH / g or more, and even more preferably 100 mgKOH / g or more, and from the viewpoint of storage stability, preferably 200 mgKOH / g or less, more preferably 180 mgKOH / g or less, and even more preferably 160 mgKOH / g or less.

[0075] From the viewpoint of storage stability, the hydroxyl value of the ester composition (E2) is preferably 0.1 mgKOH / g or more, more preferably 0.5 mgKOH / g or more, and preferably 20 mgKOH / g or less, more preferably 10 mgKOH / g or less, and even more preferably 5 mgKOH / g or less.

[0076] The weight average molecular weight of the ester composition (E) is preferably 100 or more, more preferably 150 or more, and even more preferably 200 or more from the viewpoint of further improving image density and gloss, and is preferably 2,000 or less, more preferably 1,500 or less, and even more preferably 1,000 or less from the viewpoint of low-temperature fixability.

[0077] The softening point of the ester composition (E) is preferably 40°C or higher, more preferably 50°C or higher, even more preferably 60°C or higher, and is preferably 90°C or lower, more preferably 80°C or lower, even more preferably 70°C or lower.

[0078] The ester composition (E) is preferably a crystalline composition having a melting point, and is more preferably a composition having a crystallinity index defined as the value of [softening point / maximum endothermic peak temperature] of 0.6 or more, preferably 0.7 or more, more preferably 0.9 or more, and 1.4 or less, preferably 1.2 or less, more preferably 1.1 or less.

[0079] The melting point of the ester composition (E) is preferably 30°C or higher, more preferably 40°C or higher, and even more preferably 50°C or higher from the viewpoint of storage stability, and is preferably 90°C or lower, more preferably 80°C or lower, and even more preferably 70°C or lower from the viewpoint of fixability.

[0080] The acid value, hydroxyl value, weight average molecular weight, softening point, and melting point of the ester composition (E) can be appropriately adjusted by the types and ratios of raw material monomers, as well as production conditions such as reaction temperature, reaction time, cooling rate, etc. When two or more types of ester compositions (E) are used in combination, it is preferable that the values ​​of the physical properties obtained as a mixture thereof are each within the above-mentioned ranges.

[0081] In the toner of the present invention, the content of the ester compound (E) in the total amount of the binder resin and the ester compound (E) is preferably 0.5% by mass or more, more preferably 1% by mass or more, and even more preferably 3% by mass or more, from the viewpoint of improving the dispersibility of the colorant and further improving the image density and gloss, and is preferably 15% by mass or less, more preferably 10% by mass or less, and even more preferably 7% by mass or less, from the viewpoint of storage stability.

[0082] The total content of the binder resin and the ester composition (E) in the toner is preferably 60% by mass or more, more preferably 70% by mass or more, even more preferably 80% by mass or more, and is preferably less than 100% by mass, more preferably 98% by mass or less, even more preferably 95% by mass or less.

[0083] The colorant may be either a pigment or a dye, but is preferably a pigment from the viewpoint of the remarkable effect of improving the dispersibility of the colorant. Examples of the pigment include azo pigments, phthalocyanine pigments, condensed polycyclic pigments, and lake pigments. Examples of the azo pigment include insoluble azo pigments such as CI Pigment Red 3, soluble azo pigments such as CI Pigment Red 48:1, and condensed azo pigments such as CI Pigment Red 144. Examples of the phthalocyanine pigment include copper phthalocyanine pigments such as CI Pigment Blue 15:3, polyhalogenated zinc phthalocyanine pigments such as CI Pigment Green 58, and the like. Examples of the condensed polycyclic pigments include anthraquinone pigments such as CI Pigment Red 177, perylene pigments such as CI Pigment Red 123, perinone pigments such as CI Pigment Orange 43, quinacridone pigments such as CI Pigment Red 122, naphthol pigments such as CI Pigment Red 269, dioxazine pigments such as CI Pigment Violet 23, isoindolinone pigments such as CI Pigment Yellow 139 and 185, isoindoline pigments such as CI Pigment Orange 66, quinophthalone pigments such as CI Pigment Yellow 138, nickel azo complex pigments such as CI Pigment Yellow 150, indigo pigments such as CI Pigment Red 88, metal complex pigments such as CI Pigment Green 8, diketopyrrolopyrrole pigments such as CI Pigment Red 254, CI Pigment Red 255, and CI Pigment Orange 71. An example of the lake pigment is CI Pigment Red 57:1. Among these, from the viewpoints of color development and abrasion resistance of the image, azo pigments, quinacridone pigments, isoindolinone pigments, naphthol pigments, anthraquinone pigments, and lake pigments are preferred, naphthol pigments, quinacridone pigments, and isoindolinone pigments are more preferred, and naphthol pigments and isoindolinone pigments are even more preferred. Two or more of these pigments may be used in combination.

[0084] From the viewpoint of improving the image density and low-temperature fixability of the toner, the content of the colorant is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and is preferably 40 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less, relative to 100 parts by mass in total of the binder resin and the ester composition (E).

[0085] The toner 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, the ester composition (E), and the colorant.

[0086] Examples of the release agent include hydrocarbon waxes such as polypropylene wax, polyethylene wax, polypropylene-polyethylene 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. 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 durability, 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, from the viewpoint of low-temperature fixability and durability of the toner and dispersibility in the binder resin, 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, relative to 100 parts by mass of the total of the binder resin and the ester composition (E), and is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, 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 the positively charged charge control agent 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 Examples of such resins include "VP435" (manufactured by Clariant), etc.; polyamine resins, such as "AFP-B" (manufactured by Orient Chemical Industry Co., Ltd.); imidazole derivatives, such as "PLZ-2001" and "PLZ-8001" (both manufactured by Shikoku Kasei Corporation); and styrene-acrylic resins, such as "FCA-701PT" and "FCA-201-PS" (manufactured by Fujikura Kasei Co., Ltd.).

[0091] Examples of the negatively chargeable charge control agent include metal-containing azo dyes such as "Varifast Black 3804", "Bontron S-31", "Bontron S-32", "Bontron S-34", and "Bontron S-36" (all manufactured by Orient Chemical Industry Co., Ltd.), "Aizenspiron Black TRH", and "T-77" (manufactured by Hodogaya Chemical Industry Co., Ltd.); metal compounds of benzilic acid compounds such as "LR-147" and "LR-297" (all 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 Industry Co., Ltd.), and "TN-105" (manufactured by Hodogaya Chemical Industry Co., Ltd.); copper phthalocyanine dyes; and quaternary ammonium salts such as "COPY CHARGE NX VP434 (Clariant), nitroimidazole derivatives, and organometallic compounds.

[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 total of the binder resin and the ester composition (E).

[0093] The toner of the present invention may be a toner obtained by any conventionally known method such as a melt-kneading method, an emulsion phase inversion method, or a polymerization method. However, a pulverized toner obtained by a melt-kneading method is preferred because it exhibits a more significant effect of improving the dispersibility of the colorant.

[0094] Therefore, the toner of the present invention is preferably produced by a method including a step of melt-kneading a mixture containing a binder resin, an ester composition (E), and a colorant, and further, as necessary, additives such as a release agent and a charge control agent to obtain a melt-kneaded product (melt-kneading step), and a step of pulverizing and classifying the melt-kneaded product to obtain toner particles (pulverizing and classifying step).

[0095] The mixture to be melt-kneaded may be kneaded all at once or in portions, but it is preferable to mix the mixture in advance in a mixer such as a Henschel mixer or a ball mill and then supply the mixture to the kneader.

[0096] The melt kneading can be carried out using a known kneading machine such as an internal kneader, a single-screw or twin-screw extruder, or an open roll type kneader.

[0097] The melt-kneading temperature is not particularly limited as long as the resin components are melted and mixed at the temperature.

[0098] After the melt-kneading step, it is preferable to appropriately cool the kneaded mixture until it reaches a pulverizable hardness, and then, if necessary, perform a pulverizing step and a classification step to obtain toner particles. Here, cooling refers to cooling the kneaded mixture to 0°C or higher and 50°C or lower, or cooling to the glass transition temperature of the binder resin in the kneaded mixture or lower.

[0099] The pulverization and classification steps can be appropriately carried out by a conventional method. In the pulverization step, the kneaded material may be pulverized to a desired particle size all at once or in stages. In the classification step, the pulverized material removed due to insufficient pulverization may be subjected to the pulverization step again, and the pulverization step and the classification step may be repeated as necessary.

[0100] In the toner of the present invention, it is preferable to use an external additive in order to improve transferability.The external additive includes inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide, zinc oxide, etc., and organic fine particles such as resin particles such as melamine resin fine particles and polytetrafluoroethylene resin fine particles, and two or more kinds may be used in combination.Among these, silica is preferable, and from the viewpoint of transferability of the toner, hydrophobic silica that has been hydrophobized is more preferable.

[0101] Examples of hydrophobic treatment agents for hydrophobizing the surfaces of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), silicone oil, octyltriethoxysilane (OTES), and methyltriethoxysilane.

[0102] From the viewpoint of the chargeability, fluidity, and transferability of the toner, the average particle size of the external additive is preferably 10 nm or more, 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.

[0103] From the viewpoint of the electrostatic 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 being treated with the external additive, and is preferably 5 parts by mass or less, and more preferably 3 parts by mass or less.

[0104] 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 ) refers to the particle size at which the cumulative volume frequency calculated by volume fraction is 50% calculated 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 regarded as the volume median particle size of the toner.

[0105] The toner of the present invention can be used as it is as a toner for one-component development, 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. EXAMPLES

[0106] The present invention will be described in 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.

[0107] [Softening points of resin and ester compositions] Using a flow tester "CFT-500D" (Shimadzu Corporation), 1g of sample is heated at a temperature increase rate of 6℃ / min while applying a load of 1.96MPa with the plunger, and extruding the sample from a nozzle with a diameter of 1mm and a length of 1mm. The amount of plunger descent of the flow tester is plotted against the temperature, and the temperature at which half of the sample has flowed out is taken as the softening point.

[0108] [Maximum endothermic peak temperature of resin] Using a differential scanning calorimeter "Q-20" (TA Instruments Japan, Inc.), the sample is cooled from room temperature (20°C) to 0°C at a rate of 10°C / min, maintained at that temperature for 1 minute, and then heated to 180°C at a rate of 10°C / min while measuring the calorific value. The temperature of the peak with the largest area among the endothermic peaks observed is regarded as the maximum endothermic peak temperature.

[0109] [Glass transition temperature of resin] Using a differential scanning calorimeter "Q-20" (TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of sample is weighed into an aluminum pan, heated to 200°C, and cooled to 0°C at a rate of 10°C / min. Next, the sample is heated at a rate of 10°C / min, and the glass transition temperature is determined as 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 top of the peak.

[0110] [Acid value of resin] Measure based on the method of JIS K0070:1992, except that the measurement solvent is changed from the ethanol and ether mixture specified in JIS K0070:1992 to a mixture of acetone and toluene (acetone:toluene = 1:1 (volume ratio)).

[0111] [Maximum endothermic peak temperature (melting point) of ester composition] Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan, Inc.), the sample is cooled from room temperature (20°C) to 0°C at a rate of 10°C / min, maintained at that temperature for 1 minute, and then heated to 180°C at a rate of 10°C / min while measuring the calorific value. The temperature of the peak with the largest peak area among the observed endothermic peaks is taken as the maximum endothermic peak temperature, and is also taken as the melting point.

[0112] [Acid value and hydroxyl value of ester composition] Measure based on the method of JIS K0070:1992, except that the measurement solvent is changed from the mixed solvent of ethanol and ether specified in JIS K0070:1992 to chloroform.

[0113] [Weight average molecular weight of ester composition] The molecular weight distribution is measured by gel permeation chromatography (GPC) obtained by the following method, and the weight average molecular weight is determined. (1) Preparation of sample solution The sample is dissolved in chloroform at 25° C. so that the concentration becomes 0.5 g / 100 mL. Next, this solution is filtered using a fluororesin filter "FP-200" (manufactured by Sumitomo Electric Industries, Ltd.) with a pore size of 2 μm to remove insoluble matter, and a sample solution is obtained. (2) Molecular weight measurement The following measuring equipment and analytical column were used, and chloroform was used as the eluent at a flow rate of 1 mL per minute. The column was stabilized in a thermostatic chamber at 40°C. 100 μL of the sample solution was then injected and the measurement was performed. The molecular weight of the sample was calculated based on a calibration curve that had been prepared in advance. The calibration curve used here included several types of monodisperse polystyrene "A-500" (5.0 × 10 2 ), "A-1000" (1.01 x 10 3 ), "A-2500" (2.63×10 3 ), "A-5000" (5.97 x 10 3 ), "F-1" (1.02 x 10 4 ), "F-2" (1.81 x 10 4 ), "F-4" (3.97 x 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 ) (all manufactured by Tosoh Corporation) were used as standard samples. The numbers in parentheses indicate the molecular weight. Measuring device: "CO-8010" (Tosoh Corporation) Analytical column: "GMHXL" + "G3000HXL" (manufactured by Tosoh Corporation)

[0114] [Melting point of release agent] Using a differential scanning calorimeter "DSC Q-100" (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of sample is weighed into an aluminum pan, heated to 200°C at a heating rate of 10°C / min, and cooled to -10°C at a heating rate of 5°C / min. The sample is then heated to 180°C at a heating rate of 10°C / min and measured. The maximum endothermic peak temperature observed in the melting endothermic curve obtained is taken as the melting point of the wax.

[0115] [Average particle size of external additives] The average particle size refers to the number-average particle size, and is calculated by measuring the particle sizes (average of major and minor diameters) of 500 particles in a scanning electron microscope (SEM) photograph and averaging these by number.

[0116] [Volume Median Particle Size of Toner] Measuring instrument: Coulter Multisizer III (manufactured by Beckman Coulter, Inc.) Aperture diameter: 50μm Analysis software: Multisizer III version 3.51 (Beckman Coulter, Inc.) Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) Dispersion liquid: Polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" (manufactured by Kao Corporation, HLB (Griffin) = 13.6) was dissolved in the electrolyte to adjust the concentration to 5% by mass. Dispersion conditions: 10 mg of the measurement sample is added to 5 mL of the dispersion liquid, and dispersed for 1 minute using an ultrasonic disperser (machine name: US-1, manufactured by SND Co., Ltd., output: 80 W). Then, 25 mL of electrolyte is added, and the mixture is further dispersed for 1 minute using the ultrasonic disperser to prepare a sample dispersion liquid. Measurement conditions: The sample dispersion was added to 100 mL of the electrolyte to adjust the concentration so that the particle size of 30,000 particles could be measured in 20 seconds. Then, 30,000 particles were measured, and the volume median particle size (D 50 ) is required.

[0117] Resin manufacturing example 1 The raw material monomers and esterification catalyst shown in Table 1 were placed in a 20-liter four-neck flask equipped with a thermometer, a stainless steel stirring rod, a downflow condenser, and a nitrogen inlet tube, and the temperature was raised to 235°C over 2 hours in a nitrogen atmosphere in a mantle heater. After that, when it was confirmed that the reaction rate had reached 90% or more at 235°C, the reaction was continued at 235°C under a reduced pressure of 40 kPa until the desired softening point was reached, and an amorphous polyester resin (resin A1) was obtained. The physical properties of the obtained resin are shown in Table 1.

[0118] Resin manufacturing example 2 Among the raw material monomers shown in Table 1, raw material monomers other than trimellitic anhydride and an esterification catalyst were placed in a 20-liter four-neck flask equipped with a thermometer, a stainless steel stirring rod, a downflow condenser, and a nitrogen inlet tube, and the temperature was raised to 235 ° C. over 2 hours in a mantle heater in a nitrogen atmosphere. After that, it was confirmed that the reaction rate reached 90% or more at 235 ° C., and the mixture was cooled to 190 ° C., and trimellitic anhydride shown in Table 1 was added, and the temperature was raised to 210 ° C. over 2 hours. After that, the mixture was reacted at 210 ° C. for 1 hour, and then reacted under a reduced pressure of 40 kPa until the desired softening point was reached, to obtain an amorphous polyester resin (resin B1). The physical properties of the obtained resin are shown in Table 1.

[0119] [Table 1]

[0120] Production Examples of Ester Compositions The alcohol components and carboxylic acid components shown in Tables 2 to 4 were placed in a 10-liter four-neck flask equipped with a thermometer, a stainless steel stirring rod, a downflow condenser, and a nitrogen inlet tube, and the mixture was heated in a mantle heater in a nitrogen atmosphere from 130°C to 200°C over 8 hours, and then reacted at 200°C for 2 hours. An esterification catalyst was then added, and the reaction was continued under a reduced pressure of 8 kPa until the desired softening point was reached, to obtain ester compositions (ester compositions E1-1 to E1-10, E2-1, and E2-2). The physical properties of the obtained compositions are shown in Tables 2 to 4.

[0121] [Table 2]

[0122] [Table 3]

[0123] [Table 4]

[0124] Examples 1 to 12 and Comparative Examples 1 and 2 A total of 100 parts by mass of resin components having the compounding ratio shown in Table 5, 1 part by mass of negative charge control agent "Bontron E-81" (manufactured by Orient Chemical Industry Co., Ltd.), and a colorant shown in Table 5 (magenta pigment "Permanent 10 parts by mass of "Pigment Red 269, manufactured by Sanyo Dye Co., Ltd.) or yellow pigment "Paliothol Yellow D1155" (Pigment Yellow 185, manufactured by BASF) and 2 parts by mass of release agent "HNP-9" (paraffin wax, manufactured by Nippon Seiro Co., Ltd., melting point: 80°C) were thoroughly mixed in a Henschel mixer, and then melt-kneaded at a screw rotation speed of 200 r / min and a barrel set temperature of 100°C using a co-rotating twin-screw extruder with a kneading section total length of 1560 mm, a screw diameter of 42 mm, and a barrel inner diameter of 43 mm. The feed rate of the mixture was 20 kg / h, and the average residence time was about 18 seconds. The resulting molten kneaded product was cooled and coarsely crushed, then crushed in a jet mill and classified to obtain a volume median particle size (D 50 ) yielded 8 μm toner particles.

[0125] 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 the mixture was mixed in a Henschel mixer to perform external additive treatment and obtain a toner.

[0126] Test Example 1 [Image Density] Using a commercially available printer "Microline (registered trademark) 5400" (Oki Data Corporation) on high-quality paper "J paper A4 size" (Fuji Xerox Co., Ltd.), the amount of toner attached to the paper was 0.25 to 0.30 mg / cm 2 A solid image was output, and a print was obtained. Next, the temperature of the fixing unit was set to 150° C., and the toner was fixed in the portrait direction on A4 sheets at a speed of 1.5 seconds per sheet to obtain a printed matter. The reflected image density of the fixed image of the output print was measured using a colorimeter "SpectroEye" (GretagMacbeth, light irradiation conditions: standard light source D 50 The measurements were taken using a 2° observation field, density standard DINNB, and absolute white standard. The higher the reflection image density, the better the image density. The results are shown in Table 5.

[0127] Test Example 2 [Abrasion resistance] The evaluation paper was "Business4200" (weighing weight 105g / m 2 (manufactured by Xerox Corporation) was used, and the toner loading amount was 0.50 mg / cm 2 The solid image was fixed by passing it through a fixing machine whose temperature was adjusted to 180°C. The fixed image was left for one month in an environment of 40°C and 80% relative humidity, and then rubbed five times with a sand eraser having a bottom surface of 15 mm x 7.5 mm and a load of 500 g. The optical reflection density before and after rubbing was measured using a reflection densitometer "RD-915" (manufactured by Macbeth Co., Ltd.), and the reduction rate (%) of the optical reflection density was calculated from the following formula, and the rub resistance of the fixed image was evaluated according to the following evaluation criteria. The results are shown in Table 5.

[0128] Reduction rate of optical reflection density (%) = [1-(optical reflection density after rubbing / optical reflection density before rubbing)] x 100

[0129] [Evaluation Criteria] A: The decrease in optical reflection density is less than 15%, and no change in the image due to rubbing is observed. B: The decrease in optical reflection density is 15% or more and less than 20%, and some blurring or the like is observed in the image due to rubbing. C: The decrease in optical reflection density is 20% or more and less than 25%, and blurring or the like is observed on the image due to rubbing. D: The decrease in optical reflection density is 25% or more, and image defects due to abrasion are evident.

[0130] [Table 5]

[0131] From the above results, it is apparent that the toners of Examples 1 to 12 have higher image density and better abrasion resistance than the toners of Comparative Examples 1 and 2. In contrast, in Comparative Example 1, in which the sum of the acid value and the hydroxyl value of the ester composition was small, the image density was low and the abrasion resistance was insufficient, and in Comparative Example 2, in which an ester composition not using a monovalent monomer was used, the decrease in image density was significant. [Industrial Applicability]

[0132] The toner for developing electrostatic images 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 an electrostatic charge image containing a binder resin, an ester composition (E), and a colorant, wherein the ester composition (E) is a carboxylic acid component (E1-ac) containing 55 mol% or more of an aliphatic monocarboxylic acid compound having 10 to 30 carbon atoms, and an alcohol component (E1-al) containing 80 mol% or more of a divalent or higher aliphatic alcohol having 2 to 14 carbon atoms, and an ester composition (E1) containing a condensate thereof, and an ester composition (E2) containing a condensate of an alcohol component (E2-al) containing 55 mol% or more of an aliphatic monoalcohol having 10 to 30 carbon atoms and a carboxylic acid component (E2-ac) containing 80 mol% or more of a divalent or higher aliphatic carboxylic acid compound having 2 to 14 carbon atoms is one or more selected from a toner for developing an electrostatic charge image, wherein the sum of the acid value and the hydroxyl value of the ester composition (E) is 70 mgKOH / g or more and 400 mgKOH or less.

2. The toner for developing an electrostatic charge image according to claim 1, wherein the ester composition (E) is the ester composition (E1).

3. The toner for developing an electrostatic charge image according to claim 1, wherein the ester composition (E) is the ester composition (E2).

4. The toner for developing an electrostatic charge image according to claim 2, wherein the hydroxyl value of the ester composition (E1) is 70 mgKOH / g or more and 400 mgKOH or less.

5. The toner for developing an electrostatic charge image according to claim 1, wherein the weight average molecular weight of the ester composition (E) is 2,000 or less.

6. The toner for developing an electrostatic charge image according to claim 1, wherein the ester composition (E) is a crystalline ester composition having a melting point, and the melting point is 30°C or more and 90°C or less.

7. The toner for developing an electrostatic charge image according to claim 1, wherein the binder resin contains an amorphous polyester resin.

8. The toner for developing an electrostatic charge image according to claim 1, wherein the content of the ester compound (E) is 0.5% by mass or more and 15% by mass or less in the total amount of the binder resin and the ester compound (E).

9. The toner for developing an electrostatic charge image according to claim 1, wherein the colorant is a pigment.

10. The toner for developing an electrostatic charge image according to claim 9, wherein the pigment is at least one selected from the group consisting of an azo pigment, a quinacridone pigment, an isoindolinone pigment, a naphthol pigment, an anthraquinone pigment, and a lake pigment.

11. A step of melt-kneading a mixture containing an adhesive resin, an ester composition (E), and a colorant to obtain a melt-kneaded product, and a step of pulverizing and classifying the melt-kneaded product to obtain toner particles, the method for producing an electrostatic charge image developing toner according to any one of claims 1 to 10.