Binder resin composition for toner

Abstract

To provide a binder resin composition for a toner capable of reducing odor upon fixation and excellent even in conservation, a manufacturing method therefor, and a toner for electrostatic charge image development containing the binder resin composition.SOLUTION: The present invention provides: a binder resin composition for a toner containing a polycondensate of an alcohol component, a carboxylic acid component and polyethylene terephthalate, where the carboxylic acid component contains an aliphatic dicarboxylic acid compound having 4 to 12 carbon atoms, among volatile components in the binder resin composition, the content of low-molecular-weight cyclic volatile components having a molecular weight of 50 or more and 200 or less is 25 mass% or less; a manufacturing method therefor; and a toner for electrostatic charge image development containing the binder resin composition.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a binder resin composition for a toner used for developing a latent image formed in, for example, an electrophotographic method, an electrostatic recording method, an electrostatic printing method, etc., a method for producing the same, and a toner for developing an electrostatic image containing the binder resin composition. [Background technology]

[0002] Patent Document 1 discloses a binder resin composition for toner containing one or more types of amorphous polyester and a crystalline polyester, in which at least one type of amorphous polyester is obtained by reacting an alcohol component, a carboxylic acid component, and polyethylene terephthalate, and the binder resin composition for toner contains the crystalline polyester in an amount of 0.3 to 2.5 times by mass the amount of polyethylene terephthalate-derived components in the amorphous polyester.

[0003] Patent Document 2 discloses a binder resin composition for toner, which contains one or more composite resins having a polyester resin portion and a vinyl resin portion, and a crystalline polyester, wherein the polyester resin portion of at least one composite resin is obtained by polycondensing an alcohol component containing ethylene glycol and an aromatic diol, and a carboxylic acid component.

[0004] Patent Document 3 discloses a binder resin composition for toner containing an amorphous polyester resin, which is a polycondensate of a carboxylic acid component, an alcohol component, and polyethylene terephthalate, and a crystalline polyester resin, wherein the polyethylene terephthalate has an IV value of 0.40 or more and 0.75 or less, and the mass ratio of the polyethylene terephthalate to the crystalline polyester resin (polyethylene terephthalate / crystalline polyester resin) is 0.1 or more and 15 or less. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2015-14778 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-232169 [Patent Document 3] Japanese Patent Application Publication No. 2018-13519 Summary of the Invention [Problem to be solved by the invention]

[0006] As described in Patent Documents 1 to 3, polyethylene terephthalate is used as a raw material for polyester resins for toners, and the use of polyethylene terephthalate is also useful from the viewpoint of recycling. However, when a certain type of carboxylic acid component is used as a raw material monomer, if an amorphous polyester resin using polyethylene terephthalate is used as a binder resin for toner, it is likely to give off an unpleasant odor during fixing, and it has been found that further improvement in storage stability is also required.

[0007] The present invention relates to a binder resin composition for toners which has reduced odor during fixing and excellent storage stability, a method for producing the same, and a toner for developing electrostatic images which contains the binder resin composition. [Means for solving the problem]

[0008] The present invention provides [1] A binder resin composition for toner, comprising a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate, wherein the carboxylic acid component contains an aliphatic dicarboxylic acid compound having 4 to 12 carbon atoms, and the content of low-molecular-weight cyclic volatile components having a molecular weight of 50 to 200 among the volatile components in the binder resin composition is 25 mass % or less. [2] Step 1: Polycondensing an alcohol component, a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 4 to 12 carbon atoms, and polyethylene terephthalate; Step 2: steam distilling the reaction mixture obtained in step 1; and Step 3: After step 2, the reaction system is depressurized to remove water. and a method for producing a binder resin composition for toner, comprising the steps of: [3] A toner for developing electrostatic images, comprising the binder resin composition for toner according to [1] above and a colorant. Regarding. [Effects of the Invention]

[0009] The binder resin composition for toner of the present invention is effective in reducing odor during fixing and improving the storage stability of the toner. DETAILED DESCRIPTION OF THE INVENTION

[0010] The binder resin composition for toner of the present invention contains a polycondensate using polyethylene terephthalate (PET) (hereinafter also referred to as amorphous polyester resin A), and has significant features in that the carboxylic acid component contains an aliphatic dicarboxylic acid compound having from 4 to 12 carbon atoms, and the content of low-molecular-weight cyclic volatile components among the volatile components in the binder resin composition is 25 mass % or less. Although the details are unknown, it is presumed that the effects of the present invention are achieved by the following mechanism. When an aliphatic dicarboxylic acid compound is reacted in the presence of PET, it is more likely to produce low-molecular-weight cyclic compounds through intramolecular cyclization of aliphatic dicarboxylic acid compounds with 4 to 12 carbon atoms, which are relatively susceptible to forming cyclic structures, possibly due to the influence of catalyst residues from the PET manufacturing process contained in the PET. The binder resin composition contains volatile components (VOCs) derived from polyethylene terephthalate as well as volatile components derived from low-molecular-weight cyclic compounds. It is believed that the low-molecular-weight cyclic compounds volatilize during heating (fixing) and produce an unpleasant odor. Therefore, by reducing the content of this low molecular weight cyclic compound, the odor can be reduced, and further, the decrease in the glass transition temperature of the toner due to the low molecular weight component is suppressed, thereby improving the storage stability.

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

[0012] As the alcohol component, from the viewpoint of low temperature fixability, a compound represented by the formula (I):

[0013] [ka]

[0014] (wherein 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 and are each a positive number, and the sum of x and y is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, more preferably 6 or less, and even more preferably 4 or less.) Preferred are compounds represented by the following formula (I): Examples of alkylene oxide adducts of bisphenol A represented by formula (I) include polyoxypropylene adducts of 2,2-bis(4-hydroxyphenyl)propane, polyoxyethylene adducts of 2,2-bis(4-hydroxyphenyl)propane, etc. It is preferred to use one or more of these.

[0015] The content of the alkylene oxide adduct of bisphenol A represented by formula (I) in the alcohol component is preferably 30 mol% or more, more preferably 50 mol% or more, even more preferably 70 mol% or more, and preferably 95 mol% or less, more preferably 85 mol% or less. The alcohol component also includes ethylene glycol units contained in PET.

[0016] 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 glycerin.

[0017] The carboxylic acid component contains an aliphatic dicarboxylic acid compound having 4 to 12 carbon atoms.

[0018] Examples of the aliphatic dicarboxylic acid compound having 4 to 12 carbon atoms include succinic acid (number of carbon atoms: 4), fumaric acid (number of carbon atoms: 4), adipic acid (number of carbon atoms: 6), suberic acid (number of carbon atoms: 8), azelaic acid (number of carbon atoms: 9), sebacic acid (number of carbon atoms: 10), dodecanedioic acid (number of carbon atoms: 12), succinic acid having an alkyl or alkenyl group in the side chain, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0019] The number of carbon atoms in the aliphatic dicarboxylic acid compound is 4 or more and 12 or less, preferably 10 or less, and more preferably 8 or less. The number of carbon atoms in the alkyl group of the alkyl ester moiety is not included in the number of carbon atoms in the aliphatic dicarboxylic acid compound.

[0020] The content of the aliphatic dicarboxylic acid compound having from 4 to 12 carbon atoms in the carboxylic acid component is preferably 3 mol % or more, more preferably 5 mol % or more, and preferably 90 mol % or less, more preferably 50 mol % or less, and even more preferably 25 mol % or less. The carboxylic acid component also includes terephthalic acid units contained in PET.

[0021] Examples of the carboxylic acid component other than the aliphatic dicarboxylic acid compound having 4 to 12 carbon atoms include aromatic dicarboxylic acid compounds and trivalent or higher carboxylic acid compounds.

[0022] Examples of aromatic dicarboxylic acid compounds include phthalic acid, isophthalic acid, terephthalic acid, anhydrides of these acids, and alkyl esters in which the alkyl group has a carbon number of 1 to 3. Among these, from the viewpoint of low-temperature fixability, terephthalic acid or isophthalic acid is preferred, and terephthalic acid is more preferred.

[0023] From the viewpoint of low-temperature fixability, the content of the aromatic dicarboxylic acid compound in the carboxylic acid component is preferably 5 mol % or more, more preferably 10 mol % or more, even more preferably 15 mol % or more, and is preferably 80 mol % or less, more preferably 60 mol % or less, even more preferably 50 mol % or less. The carboxylic acid component also includes terephthalic acid units contained in PET.

[0024] Examples of trivalent or higher carboxylic acid compounds include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid, anhydrides of these acids, and alkyl esters in which the alkyl group has 1 to 3 carbon atoms, and among these, trimellitic acid compounds are preferred.

[0025] From the viewpoint of hot offset resistance, the content of the trivalent or higher carboxylic acid compound in the carboxylic acid component is preferably 3 mol % or more, more preferably 10 mol % or more, and even more preferably 20 mol % or more, and is preferably 40 mol % or less, more preferably 30 mol % or less. The carboxylic acid component also includes terephthalic acid units contained in PET.

[0026] The alcohol component may contain a monohydric alcohol, and the carboxylic acid component may contain a monocarboxylic acid compound, as appropriate.

[0027] In the polycondensation reaction, PET undergoes transesterification and depolymerization with alcohol and carboxylic acid components and is incorporated into the resin structure. As a result, the resulting polyester resin is a polyester resin in which PET components, ethylene glycol and terephthalic acid, are used as raw material monomers in the polycondensation reaction. Therefore, in the present invention, the PET preferably has a relatively low IV value, i.e., a low molecular weight, compared to conventionally used PET. In the present invention, by introducing a PET with a low IV value (low molecular weight) into the polyester resin, the depolymerization of the PET proceeds more uniformly.

[0028] From the above viewpoints, the IV value of PET is preferably 0.40 or more, more preferably 0.45 or more, even more preferably 0.50 or more, and even more preferably 0.55 or more. From the viewpoints of low-temperature fixability and uniform depolymerization, it is preferably 0.85 or less, more preferably 0.80 or less, even more preferably 0.75 or less, even more preferably 0.70 or less, and even more preferably 0.65 or less. The IV value is an intrinsic viscosity and serves as an index of molecular weight. The IV value of PET can be adjusted by the polycondensation time, etc.

[0029] Commercially available PET products with an IV value of 0.40 or more and 0.85 or less include RAMAPET L1 (manufactured by Indorama Ventures, IV value: 0.60), RAMAPET BF3067 (manufactured by Indorama Ventures, IV value: 0.65), RAMAPET N2G (manufactured by Indorama Ventures, IV value: 0.75), TRN-NTJ (manufactured by Teijin Limited, IV value: 0.53), TRN-RTJC (manufactured by Teijin Limited, IV value: 0.64), and RAMAPET S1 (manufactured by Indorama Ventures, IV value: 0.84).

[0030] The content of the low IV PET in the total amount of PET used in polycondensation is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and still more preferably 100% by mass.

[0031] From the viewpoint of fixability, the content of PET is preferably 10 mol% or more of the total amount of the alcohol component, the carboxylic acid component, and the PET, and is preferably 50 mol% or less, more preferably 40 mol% or less, and even more preferably 30 mol% or less. Since PET is a polycondensation of ethylene glycol with terephthalic acid, dimethyl terephthalate, etc., the terephthalic acid-ethylene glycol unit (Mw: 192) is counted as 1 mole. Therefore, the number of moles of PET = the number of moles of ethylene glycol units = the number of moles of terephthalic acid units.

[0032] The equivalent ratio (COOH groups / OH groups) of the carboxylic acid component (including terephthalic acid units in PET) to the alcohol component (including ethylene glycol units in PET) is preferably 0.6 or more, more preferably 0.7 or more, even more preferably 0.75 or more, and is preferably 1.2 or less, more preferably 1.15 or less.

[0033] The binder resin composition of the present invention has a content of a low-molecular-weight cyclic volatile component controlled within a predetermined range. The low-molecular-weight cyclic volatile component is a low-molecular-weight cyclic volatile component having a molecular weight of 50 to 200, which is produced by intramolecular cyclization of an aliphatic dicarboxylic acid compound.

[0034] The content of low-molecular-weight cyclic volatile components is 25% by mass or less, preferably 15% by mass or less, more preferably 5% by mass or less, and even more preferably 2% by mass or less of the volatile components (total amount of volatile components) in the binder resin composition.

[0035] On the other hand, the content of low-molecular-weight cyclic volatile components in the binder resin composition is preferably 1.0 ppm or less, more preferably 0.5 ppm or less, and even more preferably 0.3 ppm or less.

[0036] The total amount of volatile components in the binder resin composition is preferably 10 ppm or less, more preferably 7 ppm or less, and even more preferably 4 ppm or less.

[0037] The binder resin composition of the present invention, in which the content of low-molecular-weight cyclic volatile components is controlled, can be obtained by, for example, a method of removing the low-molecular-weight cyclic volatile components by steam distillation. Step 1: polycondensing an alcohol component, a carboxylic acid component including an aliphatic dicarboxylic acid compound having 4 to 12 carbon atoms, and polyethylene terephthalate; Step 2: steam distilling the reaction mixture obtained in step 1; and Step 3: After step 2, the reaction system is depressurized to remove water. A method comprising the steps of:

[0038] In step 1, the polycondensation reaction of the alcohol component, the carboxylic acid component, and PET can be carried out, for example, in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and if necessary, in the presence of an esterification promoter, a polymerization inhibitor, etc., at a temperature preferably of about 180°C or higher and 250°C or lower.

[0039] Examples of esterification catalysts include tin compounds such as dibutyltin oxide and tin(II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropylate bistriethanolamine. Among these, tin compounds such as tin(II) 2-ethylhexanoate 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 1.0 part by mass or less, per 100 parts by mass of the raw material monomers (alcohol component, carboxylic acid component, and PET). Examples of esterification promoters include gallic acid. 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, per 100 parts by mass of the raw material monomers. Examples of polymerization inhibitors include tert-butylcatechol. The amount of the polymerization inhibitor used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and preferably 0.5 part by mass or less, more preferably 0.1 part by mass or less, per 100 parts by mass of the raw material monomer.

[0040] In step 2, steam distillation is a method in which water is supplied into a heated reaction system and mixed with the reaction mixture obtained in step 1, and low-molecular-weight cyclic volatile components are azeotropically distilled together with steam.

[0041] The temperature of the reaction mixture to which water is supplied is 100° C. or higher, preferably 220° C. or lower, more preferably 210° C. or lower. By mixing water into the reaction mixture in the above temperature range, water vapor remains in the polyester resin, and together with distillation, low-molecular-weight cyclic volatile components can be removed from the reaction mixture obtained in step 1.

[0042] The amount of water vapor supplied is preferably 2 parts by mass or more, more preferably 3 parts by mass or more, and even more preferably 4 parts by mass or more, per 100 parts by mass of the raw material monomers (alcohol component, carboxylic acid component, and PET) of amorphous polyester resin A, and from the viewpoint of productivity, is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 6 parts by mass or less.

[0043] The water supply rate is preferably 0.03 mass parts / min or more, more preferably 0.05 mass parts / min or more, even more preferably 0.07 mass parts / min or more, and is preferably 0.16 mass parts / min or less, more preferably 0.13 mass parts / min or less, even more preferably 0.10 mass parts / min or less, per 100 mass parts of the raw material monomers (alcohol component, carboxylic acid component, and PET) of amorphous polyester resin A.

[0044] In step 3, the water can be removed by maintaining the reaction system at a temperature of, for example, 200° C. or higher and 250° C. or lower under reduced pressure, for example, a reduced pressure of 30 kPa or lower.

[0045] When a trivalent or higher carboxylic acid compound is used as the carboxylic acid component, it is preferable to perform a polycondensation reaction after removing water until the desired softening point is reached.

[0046] The softening point of the amorphous polyester resin A is preferably 120°C or higher, more preferably 125°C or higher, and even more preferably 130°C or higher from the viewpoint of hot offset resistance, and is preferably 160°C or lower, more preferably 150°C or lower, and even more preferably 145°C or lower from the viewpoint of low-temperature fixability.

[0047] The crystallinity of a resin is expressed by the crystallinity index, which is defined as the ratio of the softening point to the maximum endothermic peak temperature measured by a differential scanning calorimeter, i.e., the value of [softening point / maximum endothermic peak temperature]. A 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 resin has a crystallinity index of more than 1.4, preferably more than 1.5, more preferably 1.6 or more, or less than 0.6, preferably 0.5 or less. The crystallinity of a resin can be adjusted by the types and ratios of raw material monomers, and production conditions (e.g., reaction temperature, reaction time, cooling rate), etc. The maximum endothermic peak temperature refers to the temperature of the peak with the largest peak area among the observed endothermic peaks. For crystalline resins, the maximum endothermic peak temperature is the melting point.

[0048] The glass transition temperature of the amorphous polyester resin A is preferably 45°C or higher, more preferably 50°C or higher, and even more preferably 52°C or higher, from the viewpoint of heat-resistant storage stability, and is preferably 70°C or lower, more preferably 65°C or lower, and even more preferably 60°C or lower, from the viewpoint of low-temperature fixability.

[0049] From the viewpoint of charging stability, the acid value of the amorphous polyester resin A is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, and is preferably 40 mgKOH / g or less, more preferably 30 mgKOH / g or less.

[0050] In the present invention, the polyester resin may be modified to such an extent that its properties are not substantially impaired. Examples of modified polyester resins include polyester resins grafted or blocked with phenol, urethane, epoxy, or the like, by the methods described in JP-A Nos. 11-133668, 10-239903, and 8-20636.

[0051] Furthermore, the present invention provides a toner containing the binder resin composition for toner of the present invention as a binder resin, specifically a toner for developing electrostatic images containing the binder resin composition for toner of the present invention and a colorant.

[0052] The toner of the present invention may contain, as a binder resin, a resin other than the binder resin composition of the present invention, and the content of the amorphous polyester resin A in the binder resin is preferably 40% by mass or more, more preferably 50% by mass or more, and even more preferably 55% by mass or more.

[0053] From the viewpoint of low-temperature fixability, the toner of the present invention preferably further contains an amorphous polyester resin (hereinafter also referred to as amorphous polyester resin AL) having a softening point lower than that of amorphous polyester resin A.

[0054] The difference in softening point between amorphous polyester resin A (hereinafter also referred to as amorphous polyester resin AH) and amorphous polyester resin AL is preferably 20°C or more, more preferably 30°C or more, even more preferably 38°C or more, and is preferably 60°C or less, more preferably 55°C or less, even more preferably 45°C or less.

[0055] The amorphous polyester resin AL is preferably a polycondensate of an alcohol component containing an alkylene oxide adduct of bisphenol A represented by the formula (I) and a carboxylic acid component containing an aromatic dicarboxylic acid compound.

[0056] 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, even more preferably 95 mol% or more, and even more preferably 100 mol%.

[0057] Examples of the aromatic dicarboxylic acid compound include the same compounds as those mentioned above, with terephthalic acid being preferred.

[0058] The content of the aromatic dicarboxylic acid compound in the carboxylic acid component is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably 100 mol%.

[0059] Examples of the carboxylic acid component other than the aromatic dicarboxylic acid compound include an aliphatic dicarboxylic acid compound and a trivalent or higher carboxylic acid compound.

[0060] The alcohol component may contain a monohydric alcohol, and the carboxylic acid component may contain a monocarboxylic acid compound, as appropriate.

[0061] The equivalent ratio of the carboxyl groups of the carboxylic acid component to the hydroxyl groups of the alcohol component (COOH groups / OH groups) 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.

[0062] The amorphous polyester resin AL can be produced by polycondensing an alcohol component and a carboxylic acid component in the same manner as the amorphous polyester resin AH.

[0063] The softening point of the amorphous polyester resin AL is preferably 80°C or higher, more preferably 83°C or higher, and even more preferably 90°C or higher, from the viewpoint of heat-resistant storage stability, and is 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 fixability.

[0064] The glass transition temperature of the amorphous polyester resin AL is preferably 45°C or higher, more preferably 50°C or higher, and even more preferably 53°C or higher, from the viewpoint of heat-resistant storage stability, and is preferably 70°C or lower, more preferably 65°C or lower, and even more preferably 60°C or lower, from the viewpoint of low-temperature fixability.

[0065] From the viewpoint of charging stability, the acid value of the amorphous polyester resin AL is preferably 2 mgKOH / g or more, more preferably 4 mgKOH / g or more, and preferably 20 mgKOH / g or less, more preferably 15 mgKOH / g or less.

[0066] The mass ratio of the amorphous polyester resin AL to the amorphous polyester resin AH (amorphous polyester resin AL / amorphous polyester resin AH) is preferably 30 / 70 or more, more preferably 40 / 60 or more, and is preferably 80 / 20 or less, more preferably 60 / 40 or less.

[0067] The total content of the amorphous polyester resin in the binder resin is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and still more preferably 100% by mass.

[0068] Other binder resins include polyester resins other than the amorphous polyester resins, vinyl resins such as styrene-acrylic resins, epoxy resins, polycarbonates, polyurethanes, and composite resins containing two or more of these resins.

[0069] The content of the binder resin in the toner is preferably 50% by mass or more, more preferably 60% by mass or more, even more preferably 70% by mass or more, and even more preferably 80% by mass or more, and is preferably 99% by mass or less, more preferably 98% by mass or less, and even more preferably 95% by mass or less.

[0070] As the colorant, dyes, pigments, magnetic materials, etc., which are used as colorants for toners, can be used. In the present invention, the toner may be either a black toner or a color toner.

[0071] As the colorant, dyes, pigments, magnetic materials, etc. used as toner colorants can be used. Examples include carbon black, phthalocyanine blue, permanent brown FG, brilliant fast scarlet, pigment red 122, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, isoindoline, disazo yellow, etc. In the present invention, the toner may be either a black toner or a color toner.

[0072] 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 preferably 40 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, relative to 100 parts by mass of the binder resin.

[0073] The toner for developing electrostatic images of the present invention may contain additives such as a release agent, a charge control agent, a magnetic powder, a flowability improver, a conductivity adjuster, a reinforcing filler such as a fibrous substance, an antioxidant, and a cleaning property improver, in addition to the binder resin and the colorant.

[0074] 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, and these may be used alone or in combination of two or more.

[0075] The melting point of the release agent is preferably 60° C. or higher, more preferably 70° C. or higher, from the viewpoint of toner transferability, and is preferably 160° C. or lower, from the viewpoint of low-temperature fixability.

[0076] The content of the release agent is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 1.5 parts by mass or more, relative to 100 parts by mass of the binder resin, from the viewpoints of the low-temperature fixability and offset resistance of the toner and the dispersibility in the binder resin, and is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 7 parts by mass or less.

[0077] 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.

[0078] Positively chargeable charge control agents include nigrosine dyes such as "Nigrosine Base EX," "Oil Black BS," "Oil Black SO," "Bontron N-01," "Bontron N-04," "Bontron N-07," "Bontron N-09," and "Bontron N-11" (all manufactured by Orient Chemical Industries Co., Ltd.); triphenylmethane dyes containing a tertiary amine as a side chain; quaternary ammonium salt compounds such as "Bontron P-51" (manufactured by Orient Chemical Industries Co., Ltd.), cetyltrimethylammonium bromide, and "COPY CHARGE PX Examples of suitable resins include polyamine resins such as "AFP-B" (manufactured by Orient Chemical Industries Co., Ltd.); imidazole derivatives such as "PLZ-2001" and "PLZ-8001" (both manufactured by Shikoku Chemical Industry Co., Ltd.); and styrene-acrylic resins such as "FCA-701PT" and "FCA-201-PS" (manufactured by Fujikura Chemical Industries Co., Ltd.).

[0079] Examples of negatively chargeable charge control agents include metal-containing azo dyes such as "Balifast 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 benzilic acid compounds such as "LR-147" and "LR-297" (manufactured by Nippon Carlit Co., Ltd.); metal compounds of salicylic acid compounds such as "Bontron E-81," "Bontron E-84," "Bontron E-88," and "Bontron E-304" (all manufactured by Orient Chemical Industries, Ltd.), and "TN-105" (manufactured by Hodogaya Chemical Co., Ltd.); copper phthalocyanine dyes; and quaternary ammonium salts such as "COPY CHARGE NX VP434 (manufactured by Clariant), nitroimidazole derivatives, etc.; organometallic compounds, etc.

[0080] 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 preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, and even more preferably 2 parts by mass or less, relative to 100 parts by mass of the binder resin.

[0081] 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, but from the viewpoint of productivity and dispersibility of the colorant, a pulverized toner obtained by a melt-kneading method is preferred. In the case of a pulverized toner obtained by a melt-kneading method, for example, raw materials such as a binder resin, a colorant, and, if necessary, a release agent and a charge control agent are uniformly mixed in a mixer such as a Henschel mixer, and then the mixture is melt-kneaded in an internal kneader, a single-screw or twin-screw extruder, an open-roll kneader, or the like, followed by cooling, pulverization, and classification to produce the toner.

[0082] In the production of toner, when the binder resin is made of a plurality of resins, a binder resin in which the plurality of resins are mixed in advance may be used, or when the toner is produced, each resin may be directly mixed with the raw materials.

[0083] In order to improve the transferability of the toner of the present invention, it is preferable to use an external additive. Examples of the external additive include inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide, and zinc oxide, and organic fine particles such as resin particles such as melamine-based resin fine particles and polytetrafluoroethylene resin fine particles, and two or more of these may be used in combination. Among these, silica is preferred, and from the viewpoint of the transferability of the toner, hydrophobic silica that has been subjected to a hydrophobic treatment is more preferred.

[0084] Examples of hydrophobic treatment agents for hydrophobizing the surfaces of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), silicone oil, octyltriethoxysilane (OTES), and methyltriethoxysilane.

[0085] From the viewpoint of the chargeability, fluidity, and transferability of the toner, the average particle diameter 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.

[0086] From the viewpoint of the chargeability, fluidity, and transferability of the toner, the content of the external additive is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, and even more preferably 0.3 parts by mass or more, relative to 100 parts by mass of the toner particles before treatment with the external additive, and is preferably 5 parts by mass or less, and more preferably 3 parts by mass or less.

[0087] The volume median particle size (D 50 ) is preferably 3 μm or more, more preferably 4 μm or more, and is preferably 15 μm or less, more preferably 10 μm or less. 50 ) means the particle size at which the cumulative volume frequency calculated by volume fraction is 50% starting from the smallest particle size. In addition, when the toner is treated with an external additive, the volume median particle size of the toner particles before treatment with the external additive is taken as the volume median particle size of the toner.

[0088] The toner of the present invention can be used as a toner for one-component development as it is, or as a toner for two-component development mixed with a carrier, in an image forming apparatus of a one-component development system or a two-component development system, respectively. [Example]

[0089] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. Physical properties of resins and the like can be measured by the following methods.

[0090] [PET IV value] The viscosity can be determined by dissolving the material in a mixed solvent of phenol / tetrachloroethane (mass ratio) 60 / 40 at a concentration of 4 g / L, measuring with an Ubbelohde viscometer, and calculating according to the following formula. IV=(-1+√(1+4kη)) / (2kC) (where k = 0.33, C = 0.004 g / mL, and η = (t1 / t0)-1 (t0: number of seconds it takes for the solvent alone to fall, t1: number of seconds it takes for the sample solution to fall).)

[0091] [Content of low molecular weight cyclic volatile components in resin] (1) Measurement of standard toluene solution Weigh 100 mg of toluene into a 100 mL volumetric flask and dilute to volume with methanol. This solution is further diluted 100 times to make the standard toluene solution. Add 10 μL of the standard toluene solution to a 20 mL headspace vial and quickly seal it with an aluminum cap. Measure the headspace gas under the conditions shown below. (2) Sample measurement 30 to 40 g of the sample is ground for 15 seconds in a coffee mill, and 500 mg of the resulting finely ground product is weighed into a 20 mL headspace vial and sealed with an aluminum cap. The vial containing the sample was placed in a headspace sampler "Agilent 7697" (Agilent Technologies) and heated at 70°C for 25 minutes. The headspace gas was then introduced into a gas chromatograph "Agilent 7890B" (Agilent Technologies) and measured under the conditions shown below. From the peak area obtained by the measurement and the toluene peak area measured above, the total amount of volatile components (TVOC) and the amount of cyclic volatile components (CVOC) with a molecular weight of 50 to 200 in the sample resin are calculated in toluene terms, and the CVOC (mass%) in the TVOC is then calculated. [Measurement conditions] Headspace sampler conditions Oven temperature: 70°C Loop temperature: 170℃ Line temperature: 200℃ Vial equilibration time: 25 minutes ·GC measurement conditions Column: DB-624 (60 m x 320 μm x 1.8 μm: Agilent Technologies) Detector: MSD Oven temperature rise conditions: Initial temperature 40°C (hold for 2 minutes) First stage temperature rise rate: 7°C / min Final temperature: 220℃ (held for 8 minutes) Inlet temperature: 200℃ Detector temperature: 300℃ Split ratio: 20:1 Column flow rate: 1.2 mL / min (He)

[0092] [Softening point of resin] Using a flow tester "CFT-500D" (Shimadzu Corporation), 1 g of sample is heated at a temperature increase rate of 6°C / min while applying a load of 1.96 MPa with the plunger, and extruding it from a nozzle 1 mm in diameter and 1 mm in length. The plunger depression distance of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is taken as the softening point.

[0093] [Maximum endothermic peak temperature of resin] Using a differential scanning calorimeter "Q-100" (TA Instruments Japan Co., Ltd.), weigh 0.01-0.02 g of sample into an aluminum pan, cool the sample from room temperature (20°C) to 0°C at a rate of 10°C / min, and maintain the sample at that temperature for 1 minute. Then, measure the endothermic peak while increasing the temperature to 180°C at a rate of 10°C / min. The temperature of the peak with the largest area among the observed endothermic peaks is taken as the maximum endothermic peak temperature.

[0094] [Glass transition temperature of resin] Using a differential scanning calorimeter "Q-20" (TA Instruments Japan), 0.01-0.02 g of sample was weighed into an aluminum pan, heated to 200°C, and cooled to 0°C at a rate of 10°C / min. The sample was then heated at a rate of 10°C / min, and the glass transition temperature was 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 peak apex.

[0095] [Acid value of resin] Measurement is performed based on the method of JIS K 0070:1992, except that the measurement solvent is changed from the ethanol and ether mixture specified in JIS K 0070 to a mixture of acetone and toluene (acetone:toluene = 1:1 (volume ratio)).

[0096] [Melting point of release agent] Using a differential scanning calorimeter "DSC 210" (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 from that temperature to -10°C at a cooling rate of 5°C / min. Next, the sample is heated to 180°C at a heating rate of 10°C / min and measured. The maximum endothermic peak temperature observed in the resulting melting endothermic curve is taken as the melting point of the release agent.

[0097] [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 values of major and minor axes) of 500 particles in a scanning electron microscope (SEM) photograph and averaging these values by number.

[0098] [Volume Median Particle Size of Toner] Measuring instrument: Coulter Multisizer II (manufactured by Beckman Coulter, Inc.) Aperture diameter: 50 μm Analysis software: Coulter Multisizer AccuComp version 1.19 (Beckman Coulter, Inc.) Electrolyte: Isoton II (Beckman Coulter, Inc.) Dispersion liquid: Emulgen 109P (Kao Corporation, polyoxyethylene lauryl ether, HLB (Griffin): 13.6) dissolved in the electrolyte to adjust the concentration to 5% by mass Dispersion conditions: 10 mg of the measurement sample was added to 5 mL of the dispersion, and the mixture was dispersed for 1 minute using an ultrasonic disperser (machine name: US-1 manufactured by SND Co., Ltd., output: 80 W). Then, 25 mL of the electrolyte solution was added, and the mixture was further dispersed for 1 minute using the ultrasonic disperser to prepare a sample dispersion. Measurement conditions: The sample dispersion was added to 100 mL of the electrolyte solution so that the particle size of 30,000 particles could be measured in 20 seconds. 30,000 particles were measured, and the volume median particle size (D 50 ) is found.

[0099] Resin manufacturing example 1 The alcohol component, terephthalic acid, PET, esterification catalyst, and esterification cocatalyst shown in Table 1 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. The mixture was heated to 235°C in a nitrogen atmosphere in a mantle heater. After confirming that the reaction rate reached 95% or more at 235°C, the mixture was cooled to 190°C. The aliphatic dicarboxylic acid compound shown in Table 1 was then added, and the mixture was heated to 230°C over two hours and then reacted at 26.7 kPa for one hour. Next, 350 g of ion-exchanged water (5 parts by mass per 100 parts by mass of raw material monomers, feed rate 0.08 parts by mass / min) was added to the resin over one hour while stirring the reaction mixture at 200°C. The mixture was then heated to 230°C, reduced pressure at 26.7 kPa for 0.5 hours, and steam distillation was performed. After that, the mixture was cooled to 190°C, and then trimellitic anhydride was added, and the mixture was maintained at 210°C for 30 minutes, and the reaction was continued under reduced pressure of 80 kPa until the softening point shown in Table 1 was reached, thereby obtaining amorphous polyester resins (resins AH1 to AH5). Note that the conversion in the present invention refers to the value of the amount of reaction water produced (mol) / theoretical amount of water produced (mol)×100.

[0100] Resin manufacturing example 2 The alcohol component, terephthalic acid, esterification catalyst, and esterification co-catalyst shown in Table 1 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 flask was heated to 235°C in a nitrogen atmosphere in a mantle heater. After confirming that the reaction rate had reached 95% or more at 235°C, the flask was cooled to 190°C. The aliphatic dicarboxylic acid shown in Table 1 was then added, and the mixture was heated to 230°C over 2 hours, followed by a reaction at 26.7 kPa for 1 hour. After cooling to 190°C, trimellitic anhydride was added, the mixture was maintained at 210°C for 30 minutes, and the reaction was continued under a reduced pressure of 80 kPa until the softening point shown in Table 1 was reached, yielding an amorphous polyester resin (Resin AH6).

[0101] Resin manufacturing example 3 The alcohol component, terephthalic acid, PET, esterification catalyst, and esterification co-catalyst shown in Table 1 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. The mixture was heated to 235°C in a nitrogen atmosphere in a mantle heater. After confirming that the reaction rate had reached 95% or more at 235°C, the mixture was cooled to 190°C. The aliphatic dicarboxylic acid shown in Table 1 was then added, and the mixture was heated to 230°C over 2 hours, followed by a reaction at 26.7 kPa for 1 hour. After cooling to 190°C, trimellitic anhydride was added, the mixture was held at 210°C for 30 minutes, and the reaction was continued under a reduced pressure of 80 kPa until the softening point shown in Table 1 was reached, yielding an amorphous polyester resin (Resin AH7).

[0102] Resin manufacturing example 4 The raw material monomers, esterification catalyst, and esterification co-catalyst shown in Table 1 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 temperature was raised to 235°C in a mantle heater under a nitrogen atmosphere. After that, it was confirmed that the reaction rate had reached 95% or more at 235°C. Thereafter, the reaction was continued under a reduced pressure of 8 kPa until the softening point shown in Table 1 was reached, yielding an amorphous polyester resin (resin AL1).

[0103] The physical properties of the obtained resins are shown in Table 1. Measurement of the maximum endothermic peak temperature was also attempted, but no endothermic peak was observed for any of the resins.

[0104] [Table 1]

[0105] Examples 1 to 5, Comparative Example 1 and Reference Example 1 100 parts by mass of the binder resin shown in Table 2, 1 part by mass of a negatively chargeable charge control agent "Bontron E-81" (manufactured by Orient Chemical Industries, Ltd.), 5 parts by mass of a colorant "Regal 330R" (manufactured by Cabot Corporation, carbon black), and 3 parts by mass of a release agent "NP-055" (manufactured by Mitsui Chemicals, Inc., polypropylene wax, melting points: 136°C, 145°C) were thoroughly mixed in a Henschel mixer, and 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 inside the roll of 100°C. The resulting melt-kneaded product was cooled and coarsely crushed, then finely crushed using an I-2 type crusher (manufactured by Nippon Pneumatic Co., Ltd.), and classified to determine the volume median particle size (D 50 ) yielded toner particles of 6.5 μm.

[0106] To 100 parts by mass of the obtained toner particles, 2.0 parts by mass of the external additive "Aerosil R-972" (hydrophobic silica, manufactured by Nippon Aerosil Co., Ltd., hydrophobic treatment agent: DMDS, average particle diameter: 16 nm) was added, and the mixture was mixed for 5 minutes at 3600 r / min using a Henschel mixer to perform external addition treatment, thereby obtaining a toner.

[0107] Test Example 1 [Odor] 10 g of toner was weighed into an aluminum cup, covered with a lid, and left to stand on a hot plate heated to 160°C for 15 minutes, and the odor emitted from the toner was evaluated according to the following evaluation criteria. The results are shown in Table 2. <Evaluation criteria> A: There is no odor at all. B: There is almost no odor. C: A slight odor is detected. D: The odor is strong.

[0108] Test Example 2 [Storage] 4 g of toner was left for 72 hours in an environment of 50°C temperature and 45% humidity. After leaving it for 48 hours and 72 hours, the degree of toner aggregation was visually observed and the storage stability was evaluated according to the following evaluation criteria. The results are shown in Table 2. <Evaluation criteria> A: No aggregation was observed even after 48 and 72 hours. B: No aggregation is observed after 48 hours, but slight aggregation is observed after 72 hours. C: No aggregation is observed after 48 hours, but aggregation is clearly observed after 72 hours.

[0109] [Table 2]

[0110] From the above results, it can be seen that in all of Examples 1 to 5, the odor was reduced and the storage stability was also good. In contrast, Resin AH7, which was not subjected to steam distillation during production, contained a higher amount of low molecular weight cyclic volatile components than Resin AH2, and Comparative Example 1, which used Resin AH7, emitted an odor and lacked shelf life. Furthermore, in Reference Example 1, in which ethylene glycol and terephthalic acid, which are components of PET, were used instead of PET, no odor was generated and the storage stability was good, which shows that the issue of odor due to low molecular weight components is not due to the type of monomer, but is due to the use of PET. [Industrial Applicability]

[0111] The toner for developing electrostatic images containing the binder resin composition for 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. Step 1: A step of polycondensing an alcohol component, a carboxylic acid component including an aliphatic dicarboxylic acid compound having from 4 to 12 carbon atoms (but not including a trivalent or higher carboxylic acid compound), and polyethylene terephthalate; Step 2: steam distilling the reaction mixture obtained in step 1; Step 3: A step of reducing the pressure in the reaction system after Step 2 to remove water; and Step 4: After Step 3, a trivalent or higher carboxylic acid compound is added and a polycondensation reaction is carried out. wherein the binder resin composition contains 10 ppm or less of volatile components, and the content of low-molecular-weight cyclic volatile components having a molecular weight of 50 or more and 200 or less among the volatile components is 25 mass % or less.

2. Step 1: A step of polycondensing an alcohol component, a carboxylic acid component including an aliphatic dicarboxylic acid compound having 4 to 12 carbon atoms (but not including a trivalent or higher carboxylic acid compound), and polyethylene terephthalate; Step 2: steam distilling the reaction mixture obtained in step 1; Step 3: A step of reducing the pressure in the reaction system after Step 2 to remove water; and Step 4: After Step 3, a trivalent or higher carboxylic acid compound is added and a polycondensation reaction is carried out. a step I for producing a binder resin composition for toner, the binder resin composition having a volatile component content of 10 ppm or less and a low-molecular-weight cyclic volatile component content of 50 to 200 of the volatile components of 25 mass % or less by a method comprising the steps of: Step II: mixing the obtained raw materials including the binder resin composition for toner, melt-kneading the mixture, cooling, pulverizing, and classifying the mixture. A method for producing a toner for developing electrostatic images, comprising:

Images