Toner binder resin composition

Abstract

The present invention relates to a binder resin composition for toner that has excellent bending resistance for printed materials, and toner for electrostatic image development containing the binder resin composition. [Solution] A binder resin composition for toner containing an amorphous polyester resin A which is a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate, wherein the carboxylic acid component contains 20 mol% to 95 mol% of a 2,5-franzicarboxylic acid compound, and a toner for electrostatic image development containing the binder resin composition.

Description

Technical Field

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

Background Art

[0002] The raw material of the polyester resin used as a binder resin in an electrostatic charge image developing toner is mainly derived from petroleum, and there are problems from the perspective of environmental load. Therefore, by using polyethylene terephthalate, which is a renewable resource, it is expected to reduce the environmental load in toner production (see Patent Document 1). Polyethylene terephthalate is also being considered as a raw material for polyester resins from the perspective of reactivity and the like (see Patent Documents 2 to 4).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Summary of the Invention

Problems to be Solved by the Invention

[0004] It is known that when polyethylene terephthalate (PET) is used as a raw material for amorphous polyester resin, PET segments remain in the polymer, and these segments pack together, increasing the strength and durability of the toner. However, this packing continues even after toner manufacturing, resulting in the formation of an excessively packed structure. As a result, this packing imparts excessive rigidity to the amorphous polyester resin, preventing sufficient conformability to the paper in terms of the bending resistance of printed materials, ultimately leading to problems with the bending resistance of printed materials.

[0005] The present invention relates to a binder resin composition for toner that has excellent bending resistance for printed materials, and toner for electrostatic image development containing the binder resin composition. [Means for solving the problem]

[0006] The present invention [1] A binder resin composition for toner containing an amorphous polyester resin A which is a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate, wherein the carboxylic acid component contains 20 mol% to 95 mol% of a 2,5-franj carboxylic acid compound, and [2] A toner for developing electrostatic images containing the toner binder resin composition described in [1] above. Regarding. [Effects of the Invention]

[0007] The toner binder resin composition of the present invention exhibits excellent effects in terms of the bending resistance of printed materials. [Modes for carrying out the invention]

[0008] The toner binder resin composition of the present invention is characterized by containing an amorphous polyester resin (amorphous polyester resin A) obtained using a 2,5-franzicarboxylic acid compound and polyethylene terephthalate (PET). The reason for the effects of the present invention is not clear, but it is presumed to be as follows. Note that the following mechanism is a hypothesis and is not limited thereto.

[0009] Because 2,5-franglicarboxylic acid compounds have two carboxyl groups that are not arranged in a straight line, using them results in a polyester resin with bent molecular chains. Therefore, by using PET in combination with 2,5-franglicarboxylic acid compounds, the presence of 2,5-franglicarboxylic acid compounds between PET segments can suppress excessive packing between PET segments. As a result, the strength of printed materials can be increased while maintaining paper conformability. Furthermore, the structure in which each polymer chain is bent while forming intermolecular packing by the PET segments, and which is prone to intermolecular entanglement, is also thought to contribute to the improved strength and bending resistance of printed materials.

[0010] Amorphous polyester resin A is a polycondensate of an alcohol component, a carboxylic acid component containing a 2,5-franzicarboxylic acid compound, and PET.

[0011] From the viewpoint of low-temperature fixation, the alcohol component preferably contains an aliphatic diol.

[0012] Aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 1,5-pentanediol, 2,3-pentanediol, 2,4-pentanediol, 1,2-hexanediol, 1,3-hexanediol, and 1,4-hexanediol. Examples include ol, 1,5-hexanediol, 1,6-hexanediol, 2,3-hexanediol, 3,4-hexanediol, 2,4-hexanediol, 2,5-hexanediol, 1,4-butenediol, neopentyl glycol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,14-tetradecanediol, and the like.

[0013] From the viewpoint of durability, the carbon number of the aliphatic diol is preferably 2 or more, more preferably 3 or more, and from the viewpoint of gloss, it is preferably 6 or less, more preferably 5 or less, and even more preferably 3 or less.

[0014] Furthermore, among aliphatic diols, those having a hydroxyl group bonded to a secondary carbon atom are preferred.

[0015] The aliphatic diol having a hydroxyl group bonded to a secondary carbon atom preferably has 3 or more carbon atoms, preferably 6 or less, and more preferably 4 or less.

[0016] Aliphatic diols having a hydroxyl group bonded to a secondary carbon atom with 3 to 6 carbon atoms include 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol, 2,3-pentanediol, and 2,4-pentanediol.

[0017] The content of the aliphatic diol is preferably 20 mol% or more, more preferably 40 mol% or more, still more preferably 60 mol% or more, and 100 mol% or less in the alcohol component.

[0018] Also, the content of the aliphatic diol having a hydroxyl group bonded to a secondary carbon atom is preferably 60 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, and 100 mol% or less in the alcohol component.

[0019] As the alcohol component other than the aliphatic diol, the formula (I):

[0020]

Chemical formula

[0021] (In the formula, OR and RO are oxyalkylene groups, R is an ethylene group and / or a propylene group, x and y represent the average number of moles of alkylene oxide added, and are positive numbers respectively. The value of the sum of x and y is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, more preferably 6 or less, still more preferably 4 or less) Examples include alkylene oxide adducts of bisphenol A represented by the formula, aromatic diols such as bisphenol A, hydrogenated bisphenol A, alicyclic diols such as 1,4-cyclohexanedimethanol, and polyhydric alcohols with a valence of 3 or more such as sorbitol, pentaerythritol, glycerin, and trimethylolpropane.

[0022] The carboxylic acid component contains a 2,5-furandicarboxylic acid-based compound. Examples of the 2,5-furandicarboxylic acid-based compound include 2,5-furandicarboxylic acid and alkyl esters of 2,5-furandicarboxylic acid. The number of carbon atoms of the alkyl group of the alkyl ester is preferably 1 to 3.

[0023] The content of the 2,5-franzicarboxylic acid compound is 20 mol% or more of the carboxylic acid component, preferably 40 mol% or more, more preferably 60 mol% or more, even more preferably 80 mol% or more, and 95 mol% or less, preferably 94 mol% or less, more preferably 93 mol% or less, and even more preferably 92 mol% or less.

[0024] Other carboxylic acid components include aromatic dicarboxylic acids other than 2,5-franzicarboxylic acid such as phthalic acid, isophthalic acid, and terephthalic acid; fumaric acid, maleic acid, succinic acid, succinic acid derivatives substituted with hydrocarbon groups; aliphatic dicarboxylic acids such as glutaric acid, adipic acid, and sebacic acid; trivalent or higher carboxylic acids such as trimellitic acid and pyromellitic acid; anhydrides of these acids; and alkyl esters of these acids with 1 to 3 carbon atoms.

[0025] The alcohol component may appropriately contain a monohydric alcohol, and the carboxylic acid component may appropriately contain a monohydric carboxylic acid compound.

[0026] In this specification, macromonomers and hydroxycarboxylic acids are not included in the alcohol and carboxylic acid components.

[0027] PET is produced by a polycondensation reaction between an alcohol component and a carboxylic acid component, and / or by the depolymerization of a portion of PET. The resulting ethylene glycol and terephthalic acid are then used as raw material monomers in the polycondensation reaction and incorporated into the polyester resin. Since PET is an equimolar polycondensate of ethylene glycol, terephthalic acid, dimethyl terephthalate, etc., the terephthalic acid-ethylene glycol unit (Mw: 192) is considered 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.

[0028] The PET can be either new virgin PET or recycled PET. Recycled PET refers to material obtained by collecting used PET, washing it as needed, separating it from other materials, crushing it, depolymerizing the crushed material to monomer units, and then resynthesizing it using these monomers as raw materials.

[0029] In this invention, it is preferable that the PET has a relatively low IV value, i.e., a low molecular weight, compared to conventionally used PET. By introducing low IV value (low molecular weight) PET into the polyester resin, the depolymerization of PET proceeds more uniformly.

[0030] From the viewpoint of the above, the IV value of PET is preferably 0.40 or higher, more preferably 0.45 or higher, even more preferably 0.50 or higher, and still more preferably 0.55 or higher. From the viewpoint of low-temperature fixability and homogenization of depolymerization, it is preferably 0.85 or lower, more preferably 0.80 or lower, even more preferably 0.75 or lower, and still more preferably 0.70 or lower. The IV value is the intrinsic viscosity and serves as an indicator of molecular weight. The IV value of PET can be adjusted by the polycondensation time, etc.

[0031] Commercially available PET products with an IV value between 0.40 and 0.85 include RAMAPET L1 (manufactured by Indorama Ventures, IV value: 0.60), RAMAPET BF3067 (manufactured by Indorama Ventures, IV value: 0.65), RAMAPET N2G (manufactured by Indorama Ventures, IV value: 0.75), TRN-NTJ (manufactured by Teijin Limited, IV value: 0.53), TRN-RTJC (manufactured by Teijin Limited, IV value: 0.64), RAMAPET S1 (manufactured by Indorama Ventures, IV value: 0.84), and UK-31 (manufactured by Utsumi Recycle Systems Co., Ltd., IV value: 0.67).

[0032] The content of low-IV PET is preferably 90% by mass or more, more preferably 95% by mass or more, even more preferably 98% by mass or more, and 100% by mass or less, of the total amount of PET subjected to polycondensation.

[0033] The PET content is preferably 10% by mass or more, more preferably 20% by mass or more, even more preferably 30% by mass or more, and preferably 60% by mass or less, more preferably 50% by mass or less, and even more preferably 40% by mass or less, based on the total amount of alcohol component, carboxylic acid component, and PET. Furthermore, the PET content is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 20 mol% or more, and preferably 50 mol% or less, more preferably 40 mol% or less, and even more preferably 30 mol% or less, based on the total amount of alcohol component, carboxylic acid component, and PET. If amorphous polyester resin A consists of two or more resins, the weighted average value of the PET content of each resin shall be used as the PET content of amorphous polyester resin A.

[0034] The mass ratio of PET to the 2,5-franglicarboxylic acid compound (PET / 2,5-franglicarboxylic acid compound) is preferably 10 / 90 or more, more preferably 25 / 75 or more, even more preferably 40 / 60 or more, and preferably 90 / 10 or less, more preferably 70 / 30 or less, and even more preferably 60 / 40 or less, from the viewpoint of the bending resistance of the printed material.

[0035] The equivalent ratio (COOH group / OH group) 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 higher, more preferably 0.7 or higher, even more preferably 0.8 or higher, and preferably 1.3 or lower, more preferably 1.2 or lower.

[0036] Amorphous polyester resin A can be produced, for example, by polycondensing an alcohol component, a carboxylic acid component, and PET in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and optionally in the presence of a co-catalyst, polymerization inhibitor, etc., at a temperature preferably 160°C or higher, more preferably 200°C or higher, and preferably 250°C or lower, more preferably 240°C or lower.

[0037] Examples of esterification catalysts include tin compounds such as dibutyltin oxide and tin(II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropoxybis(triethanolamine) and titanium dihydroxybis(triethanolamine). The amount of esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 1.5 parts by mass or less, and more preferably 1 part by mass or less, per 100 parts by mass of the total amount of alcohol component, carboxylic acid component, and PET. Examples of co-catalysts for the esterification catalyst include gallic acid. The amount of co-catalyst used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.5 parts by mass or less, and more preferably 0.1 parts by mass or less, per 100 parts by mass of the total amount of alcohol component, carboxylic acid component, and PET. Examples of polymerization inhibitors include tert-butylcatechol. The amount of polymerization inhibitor used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.5 parts by mass or less, and more preferably 0.1 parts by mass or less, based on 100 parts by mass of the total amount of alcohol component, carboxylic acid component, and PET.

[0038] In this invention, the polyester resin may be a polyester resin that has been modified to such an extent that its properties are not substantially impaired. Examples of modified polyester resins include polyester resins that have been grafted or blocked with phenol, urethane, epoxy, etc., by methods described in Japanese Patent Publication No. 11-133668, Japanese Patent Publication No. 10-239903, Japanese Patent Publication No. 8-20636, etc. Among modified polyester resins, urethane-modified polyester resins obtained by urethane elongation of polyester resin with a polyisocyanate compound are preferred.

[0039] From the viewpoint of fixation, the softening point of amorphous polyester resin A is preferably 70°C or higher, more preferably 90°C or higher, even more preferably 100°C or higher, and preferably 170°C or lower, more preferably 160°C or lower, and even more preferably 150°C or lower.

[0040] The crystallinity of a resin is expressed by a crystallinity index, which is defined by 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]. The amorphous resin is one in which no endothermic peak is observed, or, if observed, a resin with a crystallinity index greater than 1.4, preferably greater than 1.5, more preferably 1.6 or higher, or less than 0.6, preferably 0.5 or lower. On the other hand, the crystalline resin is a resin having a crystallinity index of 0.6 or higher, preferably 0.7 or higher, more preferably 0.9 or higher, and 1.4 or lower, preferably 1.2 or lower, more preferably 1.1 or lower. The crystallinity of a resin can be adjusted by the type and ratio of raw material monomers, as well as the manufacturing conditions (e.g., reaction temperature, reaction time, cooling rate). The maximum endothermic peak temperature refers to the temperature of the peak with the largest peak area among the observed endothermic peaks. In crystalline resins, the maximum endothermic peak temperature is defined as the melting point.

[0041] The glass transition temperature of amorphous polyester resin A is preferably 40°C or higher, more preferably 50°C or higher, and preferably 80°C or lower, more preferably 70°C or lower, from the viewpoint of storage properties.

[0042] From the viewpoint of electrostatic properties, the acid value of amorphous polyester resin A is preferably 5 mg KOH / g or more, more preferably 10 mg KOH / g or more, and preferably 40 mg KOH / g or less, more preferably 20 mg KOH / g or less.

[0043] The hydroxyl value of amorphous polyester resin A is preferably 10 mg KOH / g or more, more preferably 20 mg KOH / g or more, and preferably 50 mg KOH / g or less, more preferably 30 mg KOH / g or less, from the viewpoint of heat resistance and storage properties.

[0044] The content of amorphous polyester resin A in the binder resin composition is preferably 70% by mass or more, more preferably 80% by mass or more, even more preferably 85% by mass or more, and 100% by mass or less, preferably 98% by mass or less, more preferably 96% by mass or less, and even more preferably 94% by mass or less.

[0045] From the viewpoint of low-temperature fixation properties, the toner binder resin composition of the present invention preferably contains a crystalline polyester resin C.

[0046] The crystalline polyester resin C is preferably a polycondensate of an alcohol component containing an aliphatic diol and a carboxylic acid component containing an aliphatic dicarboxylic acid compound, more preferably a polycondensate of an alcohol component containing an aliphatic diol having 2 to 6 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 10 to 14 carbon atoms, and even more preferably a polycondensate of an alcohol component containing ethylene glycol and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 10 to 14 carbon atoms.

[0047] Examples of aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-butenediol, 1,7-heptanediol, 1,8-octanediol, neopentyl glycol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol.

[0048] The aliphatic diol has two or more carbon atoms, and from the viewpoint of low-temperature fixability, it is preferably 12 or less, more preferably 10 or less, even more preferably 6 or less, and even more preferably 4 or less.

[0049] From the viewpoint of improving the low-temperature fixability of the toner, aliphatic diols are preferably those having a hydroxyl group at the end of the carbon chain, and more preferably α,ω-linear alkanediols.

[0050] The content of aliphatic diols, preferably aliphatic diols having 2 to 6 carbon atoms, and more preferably ethylene glycol, is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and 100 mol% or less, in the alcohol component.

[0051] Examples of alcohol components other than aliphatic diols include alkylene oxide adducts of bisphenol A, aromatic diols such as bisphenol A, hydrogenated bisphenol A, alicyclic diols such as 1,4-cyclohexanedimethanol, and trivalent or higher alcohols such as sorbitol, pentaerythritol, glycerin, and trimethylolpropane.

[0052] Examples of aliphatic dicarboxylic acid compounds include succinic acid (4 carbon atoms), fumaric acid (4 carbon atoms), adipic acid (6 carbon atoms), suberic acid (8 carbon atoms), azelaic acid (9 carbon atoms), sebacic acid (10 carbon atoms), dodecanediic acid (12 carbon atoms), tetradecanediic acid (14 carbon atoms), anhydrides of these acids, and alkyl esters of these acids with 1 to 3 carbon atoms.

[0053] From the viewpoint of preservation, the carbon number of the aliphatic dicarboxylic acid compound is preferably 4 or more, more preferably 10 or more, and from the viewpoint of low-temperature fixability, it is preferably 14 or less, more preferably 12 or less. Here, the carbon number of the alkyl group when the aliphatic dicarboxylic acid compound is an alkyl ester is not included in the above carbon number.

[0054] The content of the aliphatic dicarboxylic acid compound is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and 100 mol% or less, of the carboxylic acid component.

[0055] Other carboxylic acid components include aromatic dicarboxylic acid compounds such as phthalic acid, isophthalic acid, and terephthalic acid, and trivalent or higher carboxylic acid compounds such as trimellitic acid and pyromellitic acid.

[0056] The alcohol component may contain a monohydric alcohol, and the carboxylic acid component may contain a monohydric carboxylic acid compound, as appropriate.

[0057] The equivalent ratio of the carboxyl group of the carboxylic acid component to the hydroxyl group of the alcohol component (COOH group / OH group) is preferably 0.8 or higher, more preferably 0.9 or higher, from the viewpoint of electrostatic stability, and preferably 1.2 or lower, more preferably 1.1 or lower, from the viewpoint of low-temperature fixability.

[0058] The polycondensation reaction conditions between the alcohol component and the carboxylic acid component of crystalline polyester resin C are the same as those for amorphous polyester resin A, except that the preferred reaction temperature is 120°C or higher, more preferably 180°C or higher, and 230°C or lower, more preferably 220°C or lower.

[0059] The softening point of the crystalline polyester resin C is preferably 50°C or higher, more preferably 65°C or higher, and even more preferably 70°C or higher, from the viewpoint of low-temperature fixability, and preferably 140°C or lower, more preferably 120°C or lower, and even more preferably 100°C or lower.

[0060] The melting point of the crystalline polyester resin C is preferably 45°C or higher, more preferably 60°C or higher, and even more preferably 65°C or higher, from the viewpoint of low-temperature fixability, and preferably 130°C or lower, more preferably 120°C or lower, and even more preferably 90°C or lower.

[0061] The acid value of the crystalline polyester resin C is preferably 2 mg KOH / g or more, more preferably 3 mg KOH / g or more, from the viewpoint of low-temperature fixability, and preferably 30 mg KOH / g or less, more preferably 20 mg KOH / g or less, from the viewpoint of durability.

[0062] The hydroxyl value of the crystalline polyester resin C is preferably 5 mg KOH / g or more, more preferably 10 mg KOH / g or more, from the viewpoint of low-temperature fixability, and preferably 30 mg KOH / g or less, more preferably 20 mg KOH / g or less, from the viewpoint of durability.

[0063] The content of crystalline polyester resin C in the binder resin composition is preferably 2% by mass or more, more preferably 4% by mass or more, and even more preferably 6% by mass or more, and from the viewpoint of durability, preferably 30% by mass or less, more preferably 20% by mass or less, and even more preferably 15% by mass or less.

[0064] The mass ratio of crystalline polyester resin C to amorphous polyester resin A (crystalline polyester resin C / amorphous polyester resin A) is preferably 2 / 98 or higher, more preferably 4 / 96 or higher, even more preferably 6 / 94 or higher, and preferably 30 / 70 or lower, more preferably 20 / 80 or lower, and even more preferably 15 / 85 or lower, from the viewpoint of low-temperature fixability.

[0065] The total content of amorphous polyester resin A and crystalline polyester resin C in the binder resin composition is preferably 80% by mass or more, more preferably 90% by mass or more, even more preferably 95% by mass or more, and 100% by mass or less.

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

[0067] Furthermore, the present invention provides a toner for electrostatic image development that contains the toner binder resin composition of the present invention as a binder resin (binding agent).

[0068] The content of the binder resin composition in the toner is preferably 60% by mass or more, more preferably 70% by mass or more, and preferably less than 100% by mass, more preferably 95% by mass or less, and even more preferably 93% by mass or less.

[0069] The toner of the present invention may contain additives other than the binder resin (binder resin composition), such as colorants, release agents, charge control agents, magnetic powders, flowability improvers, conductivity modifiers, reinforcing fillers such as fibrous materials, antioxidants, and cleaning properties improvers.

[0070] As colorants, dyes, pigments, magnetic materials, etc., used as colorants for toners can be used. Examples include carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, isoindoline, disazo yellow, etc. In this invention, the toner may be either black toner or color toner.

[0071] From the viewpoint of improving the toner's image density and low-temperature fixability, the colorant content 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, per 100 parts by mass of the binder resin composition.

[0072] Examples of mold release agents include hydrocarbon waxes and their oxides, such as polypropylene wax, polyethylene wax, ethylene propylene copolymer wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; ester waxes such as carnauba wax, montane wax and their deoxidizing waxes, and fatty acid ester waxes; and fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts, etc., which can be used individually or in combination of two or more.

[0073] The melting point of the release agent is preferably 60°C or higher, more preferably 70°C or higher, from the viewpoint of toner transferability, and preferably 160°C or lower, more preferably 140°C or lower, and even more preferably 120°C or lower, from the viewpoint of low-temperature fixation.

[0074] The release agent content is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 1.5 parts by mass or more, and preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 7 parts by mass or less, from the viewpoint of low-temperature fixation and offset resistance of the toner and dispersibility in the binder resin composition, per 100 parts by mass of the binder resin composition.

[0075] The charge control agent is not particularly limited and may contain either a positively charged charge control agent or a negatively charged charge control agent.

[0076] Positively charged charge control agents include nigrosine dyes, such as "Nigrosine Base EX," "Oil Black BS," "Oil Black SO," "Bontron N-01," "Bontron N-04," "Bontron N-07," "Bontron N-09," and "Bontron N-11" (all manufactured by Orient Chemical Industries, Ltd.); triphenylmethane-based dyes containing tertiary amines as side chains; quaternary ammonium salt compounds, such as "Bontron P-51" (manufactured by Orient Chemical Industries, Ltd.), cetyltrimethylammonium bromide, and "COPY CHARGE PX." Examples include VP435 (manufactured by Clariant), polyamine resins such as AFP-B (manufactured by Orient Chemical Industries, Ltd.), imidazole derivatives such as PLZ-2001 and PLZ-8001 (both manufactured by Shikoku Chemicals, Ltd.), and styrene-acrylic resins such as FCA-701PT and FCA-201-PS (manufactured by Fujikura Chemicals, Ltd.).

[0077] Furthermore, as negative charge control agents, metal-containing azo dyes, such as "Barifast Black 3804," "Bontron S-31," "Bontron S-32," "Bontron S-34," and "Bontron S-36" (all manufactured by Orient Chemical Industries, Ltd.), "Eisenspiron Black TRH," and "T-77" (manufactured by Hodogaya Chemical Co., Ltd.); metal compounds of benzyl acid compounds, such as "LR-147" and "LR-297" (both manufactured by Nippon Carlit Co., Ltd.); metal compounds of salicylic acid compounds, such as "Bontron E-81," "Bontron E-84," "Bontron E-88," and "Bontron E-304" (all manufactured by Orient Chemical Industries, Ltd.), and "TN-105" (manufactured by Hodogaya Chemical Co., Ltd.); copper phthalocyanine dyes; and quaternary ammonium salts, such as "COPY CHARGE NX" Examples include VP434 (manufactured by Clariant), nitroimidazole derivatives, organometallic compounds, etc.

[0078] From the viewpoint of the charge control stability of the toner, the content of the charge control agent is preferably 0.01 parts by mass or more, more preferably 0.2 parts by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, and even more preferably 2 parts by mass or less, per 100 parts by mass of the binder resin composition.

[0079] The toner of the present invention may be obtained by any of the conventionally known methods, such as the melt-kneading method, the emulsification-coagulation method, or the suspension polymerization method, and may also be a toner having a core-shell structure. However, from the viewpoint of the mixability of the toner raw materials, pulverized toner is preferred, and pulverized toner obtained by the melt-kneading method, that is, pulverized toner obtained by a method including the steps of melt-kneading the raw materials and pulverizing the resulting mixture, is more preferred. Specifically, for example, raw materials such as a binder resin composition, a colorant, a release agent, and a charge control agent can be uniformly mixed in a mixer such as a Henschel mixer, then melt-kneaded in a closed-type kneader, a single-screw or twin-screw extruder, an open-roll type kneader, etc., and then cooled, pulverized, and classified to produce the toner. In the production of the toner, a binder resin composition in which amorphous polyester resin A and crystalline polyester resin C are pre-mixed may be used, or these resins may be directly used in the mixing of raw materials when producing the toner.

[0080] In the toner of the present invention, it is preferable to use an external additive to improve fluidity. Examples of external additives include inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide, and zinc oxide, and organic fine particles such as melamine resin fine particles and polytetrafluoroethylene resin fine particles, and two or more may be used in combination. Among these, silica is preferred, and from the viewpoint of toner fluidity, hydrophobic silica that has been hydrophobicized is more preferred.

[0081] Examples of hydrophobic agents for hydrophobicizing the surface of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), cyclic silazane, silicone oil, aminosilane, octyltriethoxysilane (OTES), and methyltriethoxysilane.

[0082] The average particle size of the external additive is preferably 10 nm or larger, more preferably 250 nm or smaller, more preferably 200 nm or smaller, and even more preferably 90 nm or smaller, from the viewpoint of the toner's chargeability, fluidity, and transferability.

[0083] External additive treatment, which involves mixing toner particles with external additives, can be carried out according to conventional methods, and a mixer such as a Henschel mixer can be used.

[0084] From the viewpoint of the toner's electrostatic properties, fluidity, and transferability, the content of the external additive is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.3 parts by mass or more, and preferably 5 parts by mass or less, and more preferably 4 parts by mass or less, per 100 parts by mass of toner particles before treatment with the external additive.

[0085] The volume-intermediate particle size (D) of the toner of the present invention 50 The volume median particle size (D) is preferably 3 μm or more, more preferably 4 μm or more, and preferably 15 μm or less, more preferably 10 μm or less. 50 ) refers to the particle size at which the cumulative volume frequency calculated using volume fractions accounts for 50% when calculated from the smallest particle size. Furthermore, if the toner is treated with an external additive, the volume median particle size of the toner particles before treatment with the external additive is taken as the volume median particle size of the toner.

[0086] The toner of the present invention can be used as is as a one-component developing toner, or as a two-component developing toner used in combination with a carrier, in image forming apparatuses using either a one-component developing method or a two-component developing method, respectively. [Examples]

[0087] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way by these examples. The physical properties of resins, etc., can be measured by the following methods.

[0088] [PET IV value] The phenol / tetrachloroethane is dissolved at a concentration of 4 g / L in a 60 / 40 (mass ratio) mixed solvent, and the viscosity is measured using an Ubbelohde viscometer and calculated using the following formula. IV = (-1 + √(1 + 4kη)) / (2kC) [In the formula, k = 0.33, C = 0.004 g / mL, and η = (t1 / t0) - 1 (t0: number of seconds for the solvent to fall, t1: number of seconds for the sample solution to fall).]

[0089] [Softening point of resin] Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), 1 g of sample is heated at a heating rate of 6°C / min while a load of 1.96 MPa is applied by a plunger, and the sample is extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. The amount of plunger descent of the flow tester is plotted against temperature, and the temperature at which half of the sample has flowed out is defined as the softening point.

[0090] [Maximum peak temperature of endothermic resin] Using a differential scanning calorimeter "Q-100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.01 to 0.02 g of the sample is weighed into an aluminum pan and cooled from room temperature (25°C) to 0°C at a rate of 10°C / min, and maintained at 0°C for 1 minute. Then, measurements are taken at a rate of 10°C / min. Among the observed endothermic peaks, the temperature of the peak with the largest peak area is defined as the maximum endothermic peak temperature. For crystalline resins, the maximum endothermic peak temperature is defined as the melting point.

[0091] [Glass transition temperature of resins] Using a differential scanning calorimeter "Q-100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.01 to 0.02 g of the sample is weighed into an aluminum pan and heated from room temperature (20°C) to 200°C at a heating rate of 10°C / min, and then cooled to 0°C at a cooling rate of 10°C / min. Next, the sample is heated at a heating rate of 10°C / min and the endothermic peak is measured. The temperature at the intersection of the extension of the baseline below the maximum endothermic peak temperature and the tangent line showing the maximum slope from the rising part of the peak to the peak apex is defined as the glass transition temperature.

[0092] [Acid value of resins] Measurements will be performed according to the method of JIS K 0070:1992. However, the measurement solvent will be changed from the ethanol and ether mixed solvent specified in JIS K 0070 to an acetone and toluene mixed solvent (acetone:toluene = 1:1 (volume ratio)) for amorphous resins, and to tetrahydrofuran for crystalline resins.

[0093] [Hydroxyl value of resins] The measurement will be performed according to the method of JIS K 0070:1992. However, the measurement solvent will be changed from the mixed solvent of ethanol and ether specified in JIS K 0070 to tetrahydrofuran.

[0094] [Melting point of release agent] Using a differential scanning calorimeter "Q-100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.02 g of the sample is weighed into an aluminum pan, heated to 200°C, and then cooled from 200°C to 0°C at a rate of 10°C / min. Next, the sample is heated at a rate of 10°C / min and the heat quantity is measured, with the maximum endothermic peak temperature being defined as the melting point.

[0095] [Average particle size of external additives] The average particle diameter refers to the number-average particle diameter, which is calculated by measuring the particle size (average of the major and minor axes) of 500 particles from scanning electron microscope (SEM) images and using the number-average value of these measurements.

[0096] [Medium particle size in toner volume] • Measuring instrument: "Coulter Multisizer (Registered Trademark) III" (manufactured by Beckman Coulter, Inc.) • Aperture diameter: 100 μm • Analysis software: "Multisizer III (registered trademark) Version 3.51" (manufactured by Beckman Coulter, Inc.) • Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) • Dispersion: Prepared by dissolving polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" [manufactured by Kao Corporation, HLB (Griffin) = 13.6] in the electrolyte to adjust the concentration to 5% by mass. • Dispersion conditions: Add 10 mg of the sample to 5 mL of the dispersion and disperse for 1 minute using an ultrasonic disperser (machine name: US-1 manufactured by SND Corporation, output: 80W). Then, add 25 mL of electrolyte and disperse for another minute using the ultrasonic disperser to prepare the sample dispersion. • Measurement conditions: The sample dispersion is added to 100 mL of the electrolyte to adjust the concentration so that the particle size of 30,000 particles can be measured in 20 seconds. Then, the 30,000 particles are measured, and the volume median particle size (D) is determined from the particle size distribution. 50 )

[0097] Resin manufacturing example 1 As shown in Table 1, the alcohol component, carboxylic acid components other than trimellitic anhydride, PET, and esterification catalyst were placed in a 10-liter four-necked flask equipped with a thermometer, stainless steel stirring rod, a drop-flow condenser with a dehydration tube, and a nitrogen inlet tube. The mixture was heated in a mantle heater under a nitrogen atmosphere from 180 to 230°C over 6 hours, and the reaction was carried out at 230°C for 3 hours. After that, trimellitic anhydride was added, the temperature was raised to 220°C, and the reaction was carried out at 8 kPa until the softening point shown in Table 1 was reached, yielding amorphous polyester resins (resins A1, A3-A6).

[0098] Resin manufacturing example 2 The alcohol components, carboxylic acid components other than trimellitic anhydride, PET, and esterification catalyst shown in Table 1 were placed in a 10-liter four-necked flask equipped with a thermometer, stainless steel stirring rod, a drop-flow condenser with a dehydration tube, and a nitrogen inlet tube. The mixture was reacted at 230°C for 5 hours in a mantle heater under a nitrogen atmosphere. After that, trimellitic anhydride was added, the temperature was raised to 220°C, and the reaction was carried out at 8 kPa until the softening point shown in Table 1 was reached, yielding amorphous polyester resin (resin A2).

[0099] Resin manufacturing example 3 The alcohol components, carboxylic acid components other than trimellitic anhydride, and esterification catalyst shown in Table 1 were placed in a 10-liter four-necked flask equipped with a thermometer, stainless steel stirring rod, a drop-flow condenser with a dehydration tube, and a nitrogen inlet tube. The mixture was heated in a mantle heater under a nitrogen atmosphere from 180 to 230°C over 6 hours, and the reaction was carried out at 230°C for 3 hours. After that, trimellitic anhydride was added, the temperature was raised to 220°C, and the reaction was carried out at 8 kPa until the softening point shown in Table 1 was reached, yielding an amorphous polyester resin (resin A7).

[0100] [Table 1]

[0101] Resin manufacturing example 4 Crystalline polyester resin C1 The alcohol and carboxylic acid components shown in Table 2 were placed in a 10-liter four-necked flask equipped with a thermometer, stainless steel stirring rod, a fall-flow condenser, and a nitrogen inlet tube. The mixture was then heated to 200°C over 8 hours in a mantle heater under a nitrogen atmosphere. Subsequently, the esterification catalyst shown in Table 2 was added, and the reaction was carried out at 8 kPa until the softening point shown in Table 2 was reached, yielding a crystalline polyester resin (resin C1).

[0102] [Table 2]

[0103] Examples 1-6 and Comparative Examples 1 and 2 100 parts by mass of the binder resin composition shown in Table 3, 5 parts by mass of the coloring agent "ECB-301" (manufactured by Dainichi Seika Kogyo Co., Ltd., phthalocyanine blue), 1 part by mass of the charge control agent "LR-147" (manufactured by Nippon Carlit Co., Ltd.), 2 parts by mass of the release agent "Carnauba Wax C1" (manufactured by Kato Yoko Co., Ltd., melting point: 80°C), and 2 parts by mass of the release agent "Paraflint H105" (manufactured by Kato Yoko Co., Ltd., Fischer-Tropsch wax, melting point: 110°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 in the kneading section, a screw diameter of 42 mm, and a barrel inner diameter of 43 mm. The screw rotation speed was 200 r / min, the heating setting temperature in the roll was 100°C, the temperature of the kneaded material was 160°C, the feed rate of the kneaded material was 10 kg / h, and the average residence time was approximately 18 seconds.

[0104] The resulting mixture was cooled and then coarsely ground to a size of 2 mm or less using a Rotoplex pulverizer (manufactured by Hosokawa Micron Corporation) with a sieve with a mesh size of 2 mm.

[0105] The obtained coarse pulverized material was finely pulverized using an IDS2 type pulverizer manufactured by Nippon Pneumatic Mfg. Co., Ltd. The pulverizer conditions were as follows: the impact member was replaced with a semi-cylindrical impact member obtained by cutting a cylinder with a radius of 10 mm as its base perpendicular to the base and then halving it; the pulverizing air pressure was adjusted to 0.5 MPa; and the distance between the impact plate and the nozzle was adjusted to 20 mm. The resulting toner particle size (D) was the median particle size (D) by volume. 50 The raw material feed amount was adjusted and the material was ground so that the particle size was 6 μm and the CV value was 22.

[0106] Toner was obtained by adding 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) as an external additive to 100 parts by mass of the obtained toner particles and mixing them in a Henschel mixer.

[0107] Test example [Bending resistance of printed materials] A modified fuser unit of the "AR-505" copier (manufactured by Sharp Corporation) was modified to allow for external fixing, and toner was installed in this modified unit. A printed document was obtained in an unfixed state (print area: 20cm x 20cm, adhesion amount: 0.5mg / cm²). 2 ). Subsequently, the image was fixed using a fuser (fixing speed 300 mm / sec) adjusted to achieve a total fixing pressure of 40 kgf, with the fixing roll temperature set to 150°C. This image was then fixed at 50 g / cm². 2 The print was folded inward for 30 seconds, then unfolded, and the damaged image was wiped with a soft cloth. The maximum width of the image defect was used as an indicator of the print's bending resistance. The results are shown in the table. A smaller value indicates better bending resistance of the print. The fixing paper used was "Copy Bond SF-70NA" (manufactured by Sharp Corporation, 75g / m²). 2 ) was used.

[0108] [Table 3]

[0109] From the above results, it can be seen that the toners of Examples 1 to 6 have better bending resistance compared to the toner of Comparative Example 1, in which a 2,5-franjicarboxylic acid compound was not used in the amorphous polyester resin, and the toner of Comparative Example 2, which contained an amorphous polyester resin using ethylene glycol and terephthalic acid instead of PET. [Industrial applicability]

[0110] The toner for electrostatic image development containing the toner binder resin composition of the present invention is suitably used for developing latent images formed in electrostatic image development methods, electrostatic recording methods, electrostatic printing methods, and the like.

Claims

1. A binder resin composition for toner containing an amorphous polyester resin A which is a polycondensate of an alcohol component, a carboxylic acid component, and polyethylene terephthalate, wherein the carboxylic acid component contains 20 mol% to 95 mol% of a 2,5-franj carboxylic acid compound.

2. The toner binder resin composition according to claim 1, wherein the polyethylene terephthalate content is 10% by mass or more and 60% by mass or less of the total amount of the alcohol component, the carboxylic acid component, and polyethylene terephthalate.

3. The toner binder resin composition according to claim 1 or 2, wherein the mass ratio of polyethylene terephthalate to a 2,5-franzicarboxylic acid compound is 10 / 90 or more and 90 / 10 or less.

4. Furthermore, the toner binder resin composition according to claim 1 or 2, wherein it contains a crystalline polyester resin C, and the content of the crystalline polyester resin C is 2% by mass or more and 30% by mass or less of the total amount of amorphous polyester resin A and crystalline polyester resin C.

5. The binder resin composition for toner according to claim 4, wherein the crystalline polyester resin C is a polycondensate of an alcohol component containing an aliphatic diol having 2 to 6 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 10 to 14 carbon atoms.

6. A toner for developing electrostatic images, comprising the toner binder resin composition described in claim 1 or 2.

Images