Binder resin composition for toner

Abstract

To provide a binder resin composition for a toner which is excellent in durability, and a toner for electrostatic charge image development containing the binder resin composition.SOLUTION: There are provided a binder resin composition for a toner which contains an amorphous polyester resin and a crystalline polyester resin, wherein the amorphous polyester resin contains an amorphous polyester resin A which is a polycondensation product of an alcohol component containing 15 mol% or more and 50 mol% or less of alicyclic diol and a carboxylic acid component containing 20 mol% or more and 45 mol% or less of a succinic acid derivative which is substituted with a hydrocarbon group having 8 or more and 15 or less carbon atoms; 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 toners used for developing latent images formed in electrophotography, electrostatic recording, electrostatic printing, etc., and to a toner for developing electrostatic images containing the binder resin composition. [Background technology]

[0002] With the recent increase in environmental awareness, there is a demand for electrophotographic printers and copiers to not only save energy by using toners that can be fixed at low temperatures, but also for developing systems with highly durable toners that can extend their lifespan in order to reduce the environmental impact. Therefore, there is a demand for binder resins, which are the main component of toners, to be highly durable in addition to having low-temperature fixability.

[0003] Patent Document 1 discloses a toner having toner particles containing a binder resin, a pigment, a crystalline resin, and an amorphous resin, wherein the adsorption rate A1 of the crystalline resin to the pigment and the adsorption rate A2 of the amorphous resin are in a specific relationship, and the predetermined compatibility is 70% or less, and the toner is said to have excellent low-temperature fixability, durability, and coloring power.

[0004] Patent Document 2 discloses an agitation device and a method for producing aggregated particles, in which a first dispersion liquid containing first resin particles is introduced into an agitation tank, and while the first dispersion liquid is being agitated with an agitator blade, a second dispersion liquid containing second resin particles is brought into contact with the inner wall of the agitation tank, thereby suppressing the formation of coarse particles.

[0005] Patent Document 3 describes a toner binder made of polyester, in which the dielectric loss tangent (tan δ) of the polyester at a measurement frequency of 100 kHz is 8×10 -3 The toner binder is disclosed as having the following characteristics, and is said to be capable of providing a toner having excellent low-temperature fixability and hot offset resistance, as well as excellent environmental stability.

[0006] Patent Document 4 discloses a color toner comprising a toner binder, a wax, and a colorant, wherein the toner binder is made of a resin containing 1 to 50% by weight of a hydrocarbon group having 8 or more carbon atoms, and wherein the haze value of the toner binder is 70 or less, and the toner is described as having excellent heat-resistant storage stability, low-temperature fixability, and hot offset resistance. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-157107 [Patent Document 2] Japanese Patent Application Publication No. 2019-28158 [Patent Document 3] Japanese Patent Application Laid-Open No. 2000-29246 [Patent Document 4] Japanese Patent Application Laid-Open No. 2000-250264 Summary of the Invention [Problem to be solved by the invention]

[0008] It is known that crystalline polyester resins are used as binder resins that are effective in improving the low-temperature fixability of toners. However, if the crystalline polyester resin does not disperse sufficiently in the toner and segregates, there is a problem that even if the low-temperature fixability is improved, the durability is significantly reduced due to the segregated crystalline polyester resin.

[0009] In the toner described in Patent Document 1, a crystalline polyester resin is used as the crystalline resin, but a styrene acrylic resin is used as the binder resin, and although an amorphous polyester resin that has high affinity with the crystalline polyester resin is used as the amorphous resin, the blending amount is small, so durability cannot be said to be sufficient. In addition, the blending amount of the crystalline polyester resin is also small, and it is thought that durability will be insufficient when the crystalline polyester resin is increased in amount for low-temperature fixability.

[0010] Although the toner described in Patent Document 2 contains a crystalline polyester resin and an amorphous polyester resin, the amorphous polyester resin has low hydrophobicity and insufficient affinity with the crystalline polyester resin, which is thought to cause durability problems.

[0011] The toner binder described in Patent Document 3 does not take into consideration the use of crystalline polyester resin, and it is thought that a problem will arise in durability when crystalline polyester resin is used.

[0012] The toner described in Patent Document 4 does not take into consideration the use of a crystalline polyester resin as a toner binder, and it is believed that a problem will arise in durability when a crystalline polyester resin is used.

[0013] The present invention relates to a binder resin composition for toners, which has excellent durability, and toners for developing electrostatic images, which contain the binder resin composition. [Means for solving the problem]

[0014] The present inventors have conducted extensive research based on the belief that the amorphous polyester resin used together with the crystalline polyester resin is important, and have found that it is effective to include an alcohol component and a carboxylic acid component having specific structures as monomer components constituting the amorphous polyester, thereby completing the present invention.

[0015] The present invention provides [1] A binder resin composition for toner containing an amorphous polyester resin and a crystalline polyester resin, wherein the amorphous polyester resin contains an amorphous polyester resin A which is a polycondensate of an alcohol component containing 15 mol % to 50 mol % of an alicyclic diol and a carboxylic acid component containing 20 mol % to 45 mol % of a succinic acid derivative substituted with a hydrocarbon group having 8 to 15 carbon atoms; and [2] A toner for developing electrostatic images, containing the binder resin composition for toners according to [1] above as a binder resin. Regarding. [Effects of the Invention]

[0016] The binder resin composition for toner of the present invention exhibits excellent effects in terms of durability. DETAILED DESCRIPTION OF THE INVENTION

[0017] The binder resin composition for toners of the present invention is characterized in that it contains an amorphous polyester resin and a crystalline polyester resin, and the amorphous polyester resin contains amorphous polyester resin A, which is a polycondensate of an alcohol component containing an alicyclic diol and a carboxylic acid component containing a succinic acid derivative substituted with a hydrocarbon group. The reason why a toner for developing electrostatic images containing the binder resin composition for toners of the present invention has excellent durability is not clear, but is presumed to be as follows. Note that the following mechanism is presumed and is not limited thereto.

[0018] The amorphous polyester resin obtained using an alicyclic diol has a three-dimensionally large hydrophobic structure in the main chain derived from the alicyclic diol, whereas the amorphous polyester resin obtained using an alkenyl succinic acid has a hydrophobic structure in the side chain derived from a hydrocarbon group, resulting in a polyester resin having a hydrophobic structure in the side chain. Therefore, amorphous polyester resin A obtained using both an alicyclic diol and an alkenyl succinic acid has many hydrophobic structures in both the main chain and side chain. Therefore, by using a crystalline polyester resin in combination with amorphous polyester resin A, the crystalline polyester resin is dispersed among the many hydrophobic structural portions of amorphous polyester resin A. This prevents the crystalline polyester resin from segregating in the toner, improving durability. Furthermore, amorphous polyester resin A, which has a three-dimensionally large structure derived from an alicyclic diol in the main chain, has limited freedom of polymer movement. This, combined with the presence of ester bonds, provides rigidity, which is thought to improve the robustness of the toner and further enhance the durability improvement effect.

[0019] As described above, the amorphous polyester resin A is a polycondensation product of an alcohol component containing an alicyclic diol and a carboxylic acid component containing a succinic acid derivative substituted with a hydrocarbon group.

[0020] In the present invention, an alicyclic diol is a diol having an alicyclic hydrocarbon ring. The number of carbon atoms in the alicyclic hydrocarbon ring is preferably 4 or more, more preferably 5 or more, and preferably 10 or less, more preferably 8 or less. For fused rings, the number of carbon atoms refers to the total number of carbon atoms in the fused rings.

[0021] The alicyclic hydrocarbon ring may be a saturated hydrocarbon ring or an unsaturated hydrocarbon ring, but from the viewpoint of durability of the toner, it is preferably a saturated hydrocarbon ring.

[0022] The number of alicyclic hydrocarbon rings may be 1 or 2 or more, but from the viewpoint of durability of the toner, it is preferably 1 or 2. As for the fused ring, it is considered to be 1 ring.

[0023] Examples of alicyclic diols include hydrogenated bisphenol A, 1,4-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,4-cyclohexanediol, 1,2-cyclohexanediol, tricyclodecane dimethanol, tetramethylcyclobutanediol, etc. Among these, from the viewpoint of the hydrophobicity of the amorphous polyester resin and the durability of the toner, at least one selected from the group consisting of hydrogenated bisphenol A, 1,4-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, 1,4-cyclohexanediol, and 1,2-cyclohexanediol is preferred, and hydrogenated bisphenol A and / or 1,4-cyclohexanedimethanol is more preferred.

[0024] The content of the alicyclic diol in the alcohol component is 15 mol% or more, preferably 20 mol% or more, more preferably 25 mol% or more, and from the viewpoint of low-temperature fixability, is 50 mol% or less, preferably 45 mol% or less, more preferably 40 mol% or less.

[0025] From the viewpoint of low-temperature fixability, the alcohol component preferably further contains an aliphatic diol.

[0026] Examples of aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,5-pentanediol, 2,4-pentanediol, 3-methyl-1,5-pentanediol, 1,2-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 3,3-dimethyl-1,2-butanediol, and 2,2-dimethyl-1,3-propanediol.

[0027] The carbon number of the aliphatic diol is 2 or more, and from the viewpoint of durability of the toner, is preferably 5 or less, more preferably 4 or less, and even more preferably 3 or less.

[0028] The content of the aliphatic diol in the alcohol component is preferably 50 mol % or more, more preferably 60 mol % or more, and preferably 85 mol % or less, more preferably 80 mol % or less.

[0029] Examples of other alcohol components include alkylene oxide adducts of bisphenol A, aromatic diols such as bisphenol A, and trihydric or higher alcohols such as sorbitol, pentaerythritol, glycerin, and trimethylolpropane.

[0030] On the other hand, in the succinic acid derivative substituted with a hydrocarbon group contained in the carboxylic acid component, the number of carbon atoms in the hydrocarbon group is 8 or more, preferably 10 or more, and 15 or less, preferably 12 or less, from the viewpoint of the hydrophobicity of the amorphous polyester resin.

[0031] Examples of the hydrocarbon group include an alkyl group, an alkenyl group, an aromatic hydrocarbon group, and an alicyclic hydrocarbon group, and among these, an alkenyl group is preferred.

[0032] Specific examples of succinic acid derivatives substituted with an alkenyl group include octenylsuccinic acid, dodecenylsuccinic acid, pentadecenylsuccinic acid, acid anhydrides thereof, and alkyl esters thereof having from 1 to 3 carbon atoms. Among these, dodecenylsuccinic acid or its anhydride is preferred, and dodecenylsuccinic anhydride is more preferred.

[0033] The content of the succinic acid derivative substituted with a hydrocarbon group in the carboxylic acid component is 20 mol % or more, preferably 25 mol % or more, and from the viewpoint of toner durability, 45 mol % or less, preferably 40 mol % or less, more preferably 35 mol % or less.

[0034] From the viewpoint of durability of the toner, it is preferable that the carboxylic acid component further contains an aromatic dicarboxylic acid compound.

[0035] Examples of aromatic dicarboxylic acid compounds include phthalic acid, isophthalic acid, terephthalic acid, anhydrides of these acids, and alkyl esters of these acids having a carbon number of 1 to 3. Of these, terephthalic acid is preferred.

[0036] The content of the aromatic dicarboxylic acid compound in the carboxylic acid component is preferably 50 mol% or more, more preferably 60 mol% or more, even more preferably 65 mol% or more, and is preferably 80 mol% or less, more preferably 75 mol% or less.

[0037] Examples of other carboxylic acid components include aliphatic dicarboxylic acid compounds other than succinic acid derivatives substituted with a hydrocarbon group, and trivalent or higher carboxylic acid compounds.

[0038] Examples of the aliphatic dicarboxylic acid compound include fumaric acid, maleic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0039] Examples of the trivalent or higher carboxylic acid compound include trimellitic acid, pyromellitic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0040] The alcohol component may contain a monohydric alcohol, and the carboxylic acid component may contain a monocarboxylic acid compound, as appropriate.

[0041] In this specification, macromonomers and hydroxycarboxylic acids are not included in the alcohol component and carboxylic acid component.

[0042] 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 0.8 or more, and is preferably 1.3 or less, more preferably 1.2 or less.

[0043] The amorphous polyester resin A can be produced, for example, by polycondensing an alcohol component and a carboxylic acid component in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and optionally in the presence of a co-catalyst, a polymerization inhibitor, etc., at a temperature of preferably 130°C or higher, more preferably 170°C or higher, and preferably 250°C or lower, more preferably 240°C or lower.

[0044] Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and tin(II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropoxybis(triethanolaminate). The amount of the esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 1.5 parts by mass or less, more preferably 1 part by mass or less, per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Examples of the co-catalyst for the esterification catalyst include gallic acid. The amount of the 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, more preferably 0.1 parts by mass or less, per 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Examples of the polymerization inhibitor include tert-butylcatechol. The amount of the polymerization inhibitor used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and preferably 0.5 part by mass or less, more preferably 0.1 part by mass or less, relative to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component.

[0045] 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. Among the modified polyester resins, urethane-modified polyester resins in which polyester resins are urethane-extended with a polyisocyanate compound are preferred.

[0046] The softening point of the amorphous polyester resin A is preferably 90°C or higher, more preferably 100°C or higher, from the viewpoint of charging stability, and is preferably 150°C or lower, more preferably 140°C or lower, from the viewpoint of low-temperature fixability.

[0047] The crystallinity of a resin is expressed by a crystallinity index defined as the ratio of the softening point to the maximum endothermic peak temperature measured by a differential scanning calorimeter, that is, the value of [softening point / maximum endothermic peak temperature]. 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. On the other hand, the crystalline resin is a resin having a crystallinity index of 0.6 or more, preferably 0.7 or more, more preferably 0.9 or more, and 1.4 or less, preferably 1.2 or less, more preferably 1.1 or less. 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 40°C or higher, more preferably 50°C or higher, from the viewpoint of storage stability, and is preferably 80°C or lower, more preferably 75°C or lower, from the viewpoint of low-temperature fixability.

[0049] The acid value of the amorphous polyester resin A is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, from the viewpoint of charging stability, and is preferably 50 mgKOH / g or less, more preferably 40 mgKOH / g or less, from the viewpoint of low-temperature fixability.

[0050] The content of the amorphous polyester resin A in the amorphous polyester resin is preferably 30% by mass or more, more preferably 40% by mass or more, and 100% by mass or less, from the viewpoint of low-temperature fixability.

[0051] In the binder resin composition of the present invention, the amorphous polyester resin preferably comprises a linear polyester resin and a crosslinked polyester resin from the viewpoints of low-temperature fixability and fixation width. Here, the linear polyester resin is a polyester having a straight-chain structure. The alcohol component and carboxylic acid component of the linear polyester resin do not contain a trivalent or higher polyvalent monomer as a crosslinking component, or if they do, the content of the trivalent or higher polyvalent monomer is preferably less than 1.5 mol %, more preferably 1.0 mol % or less, and even more preferably 0.5 mol % or less of the total amount of the alcohol component and the carboxylic acid component. On the other hand, a crosslinked polyester resin is a polyester resin having a branched or network structure. The alcohol component and carboxylic acid component of the crosslinked polyester resin preferably contain a trivalent or higher valent monomer, and the content of the trivalent or higher valent monomer in the total amount of the alcohol component and the carboxylic acid component is preferably 1.5 mol% or more, more preferably 2.5 mol% or more, even more preferably 4.0 mol% or more, and preferably 20 mol% or less, more preferably 15 mol% or less, even more preferably 10 mol% or less. The trivalent or higher valent monomer refers to at least one of a trivalent or higher valent alcohol and a trivalent or higher carboxylic acid compound, and the above content is the content of the trivalent or higher valent alcohol or the trivalent or higher carboxylic acid compound, or if both are contained, the total content of both.

[0052] The mass ratio of the linear polyester resin to the crosslinked polyester resin (linear polyester resin / crosslinked polyester resin) is preferably 10 / 90 or more, more preferably 30 / 70 or more, even more preferably 40 / 60 or more, and is preferably 90 / 10 or less, more preferably 30 / 70 or less, even more preferably 60 / 40 or less.

[0053] In the binder resin composition for toner of the present invention, either one of the linear polyester resin and the crosslinked polyester resin may be the amorphous polyester resin A, or both may be the amorphous polyester resin A. However, it is preferable that at least the linear polyester resin is the amorphous polyester resin A.

[0054] In the binder resin composition of the present invention, the amorphous polyester resin preferably comprises resins having different softening points from the viewpoints of low-temperature fixability and fixation width. The difference in softening point between the two resins is preferably 3° C. or more, more preferably 10° C. or more, and is preferably 30° C. or less, more preferably 25° C. or less.

[0055] The softening point of the amorphous polyester resin having a higher softening point (resin AH) is preferably 110°C or higher, more preferably 120°C or higher, from the viewpoint of fixing width, and is preferably 150°C or lower, more preferably 140°C or lower, from the viewpoint of low-temperature fixability.

[0056] Furthermore, the softening point of the amorphous polyester resin (resin AL) having a lower softening point is preferably 90°C or higher, more preferably 100°C or higher, from the viewpoint of charging stability, and is preferably 130°C or lower, more preferably 120°C or lower, from the viewpoint of low-temperature fixability.

[0057] The mass ratio of resin AH to resin AL (resin AH / resin AL) is preferably 20 / 80 or more, more preferably 30 / 70 or more, even more preferably 40 / 60 or more, and preferably 80 / 20 or less, more preferably 70 / 30 or less, even more preferably 60 / 40 or less.

[0058] In the binder resin composition for toner of the present invention, either one of resin AH and resin AL may be the amorphous polyester resin A, or both may be the amorphous polyester resin A. However, it is preferable that at least resin AL is the amorphous polyester resin A.

[0059] When the binder resin composition for toner of the present invention contains an amorphous polyester resin other than the amorphous polyester resin A (hereinafter referred to as amorphous polyester resin B), (1) A combination of an amorphous polyester resin A, which is a linear polyester resin and corresponds to resin AL, and an amorphous polyester resin B, which is a crosslinked polyester resin and corresponds to resin AH, (2) A combination of amorphous polyester resin A, which is a linear polyester resin and corresponds to resin AH, and amorphous polyester resin B, which is a cross-linked polyester resin and corresponds to resin AL. (3) A combination of an amorphous polyester resin A, which is a crosslinked polyester resin and corresponds to resin AL, and an amorphous polyester resin B, which is a linear polyester resin and corresponds to resin AH; and (4) A combination of amorphous polyester resin A, which is a cross-linked polyester resin and corresponds to resin AH, and amorphous polyester resin B, which is a linear polyester resin and corresponds to resin AL. However, the embodiment (1) or the embodiment (2) is preferred, and the embodiment (1) is more preferred.

[0060] From the viewpoint of low-temperature fixability and durability, the amorphous polyester resin B is preferably a polycondensate of an alcohol component containing an aliphatic diol and a carboxylic acid component containing an aromatic dicarboxylic acid compound.

[0061] The aliphatic diol is the same as the example of the amorphous polyester resin A.

[0062] The content of the aliphatic diol in the alcohol component is preferably 80 mol % or more, more preferably 90 mol % or more, and even more preferably 95 mol % or more, and 100 mol % or less.

[0063] Examples of other alcohol components include aromatic diols and trihydric or higher alcohols.

[0064] The aromatic dicarboxylic acid compound is the same as the examples of the amorphous polyester resin A, and terephthalic acid is preferred.

[0065] 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, and preferably 100 mol % or less, more preferably 90 mol % or less.

[0066] Examples of other carboxylic acid components include aliphatic dicarboxylic acid compounds and trivalent or higher carboxylic acid compounds.

[0067] Like the amorphous polyester resin A, the amorphous polyester resin B is also obtained by polycondensation of an alcohol component and a carboxylic acid component.

[0068] The glass transition temperature of the amorphous polyester resin B is preferably 50° C. or higher from the viewpoint of storage stability and pulverizability, and is preferably 65° C. or lower from the viewpoint of low-temperature fixability.

[0069] The acid value of the amorphous polyester resin B is preferably 10 mgKOH / g or more, more preferably 15 mgKOH / g or more, from the viewpoint of low-temperature fixability, and is preferably 35 mgKOH / g or less, more preferably 25 mgKOH / g or less, from the viewpoint of charging stability.

[0070] The content of the amorphous polyester resin B in the amorphous polyester resin is preferably 70% by mass or less, and more preferably 60% by mass or less.

[0071] The content of the amorphous polyester resin in the binder resin composition is preferably 80% by mass or more, more preferably 85% by mass or more, and preferably 99% by mass or less, more preferably 95% by mass or less, and even more preferably 90% by mass or less.

[0072] The crystalline polyester resin is preferably a polycondensate of an alcohol component containing an aliphatic diol and a carboxylic acid component containing an aliphatic dicarboxylic acid compound.

[0073] 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.

[0074] The aliphatic diol has 2 or more carbon atoms, preferably 4 or more, more preferably 6 or more carbon atoms, and from the viewpoint of low-temperature fixability, preferably 12 or less, more preferably 10 or less carbon atoms.

[0075] From the viewpoint of improving the low-temperature fixability of the toner, the aliphatic diol preferably has a hydroxyl group at the end of the carbon chain, and is more preferably an α,ω-straight-chain alkanediol.

[0076] The content of the aliphatic diol in the alcohol component is preferably 80 mol % or more, more preferably 90 mol % or more, and even more preferably 95 mol % or more, and 100 mol % or less.

[0077] 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, trihydric or higher alcohols such as sorbitol, pentaerythritol, glycerin, and trimethylolpropane.

[0078] Examples of the aliphatic dicarboxylic acid compound include succinic acid (number of carbon atoms: 4), fumaric acid (number of carbon atoms: 4), adipic acid (number of carbon atoms: 6), suberic acid (number of carbon atoms: 8), azelaic acid (number of carbon atoms: 9), sebacic acid (number of carbon atoms: 10), dodecanedioic acid (number of carbon atoms: 12), tetradecanedioic acid (number of carbon atoms: 14), anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0079] From the viewpoint of storage stability, the number of carbon atoms in the aliphatic dicarboxylic acid compound is preferably 10 or more, and from the viewpoint of low-temperature fixability, it is preferably 14 or less, more preferably 12 or less. When the aliphatic dicarboxylic acid compound is an alkyl ester, the number of carbon atoms in the alkyl group is not included in the above carbon number.

[0080] The content of the aliphatic dicarboxylic acid compound in the carboxylic acid component is preferably 80 mol % or more, more preferably 90 mol % or more, and even more preferably 95 mol % or more, and 100 mol % or less.

[0081] Examples of other carboxylic acid components include aromatic dicarboxylic acid compounds such as phthalic acid, isophthalic acid, and terephthalic acid, and trivalent or higher carboxylic acid compounds such as trimellitic acid and pyromellitic acid.

[0082] The alcohol component may contain a monohydric alcohol, and the carboxylic acid component may contain a monocarboxylic acid compound, as appropriate.

[0083] 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 0.8 or more, more preferably 0.9 or more, from the viewpoint of charging stability, and is preferably 1.2 or less, more preferably 1.1 or less, from the viewpoint of low-temperature fixability.

[0084] The polycondensation reaction conditions of the alcohol component and the carboxylic acid component of the crystalline polyester resin are the same as those of the amorphous polyester resin A, except that the suitable reaction temperature is 120°C or higher, more preferably 180°C or higher, and 230°C or lower, more preferably 220°C or lower.

[0085] From the viewpoint of durability, the softening point of the crystalline polyester resin is preferably 50°C or higher, more preferably 65°C or higher, and even more preferably 70°C or higher, and from the viewpoint of low-temperature fixability, it is preferably 140°C or lower, more preferably 120°C or lower, and even more preferably 100°C or lower.

[0086] From the viewpoint of durability, the melting point of the crystalline polyester resin is preferably 45°C or higher, more preferably 60°C or higher, and even more preferably 65°C or higher, and from the viewpoint of low-temperature fixability, it is preferably 130°C or lower, more preferably 120°C or lower, and even more preferably 90°C or lower.

[0087] The acid value of the crystalline polyester resin is preferably 5 mgKOH / g or more, more preferably 10 mgKOH / g or more, from the viewpoint of low-temperature fixability, and is preferably 30 mgKOH / g or less, more preferably 20 mgKOH / g or less, from the viewpoint of durability.

[0088] The content of the crystalline polyester resin in the binder resin composition is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, from the viewpoint of low-temperature fixability, and is preferably 20% by mass or less, more preferably 15% by mass or less, from the viewpoint of durability.

[0089] From the viewpoint of low-temperature fixability, the mass ratio of the crystalline polyester resin to the amorphous polyester resin (crystalline polyester resin / amorphous polyester resin) is preferably 1 / 99 or more, more preferably 5 / 95 or more, even more preferably 10 / 90 or more, and is preferably 20 / 80 or less, more preferably 15 / 85 or less.

[0090] The total content of the amorphous polyester resin and the crystalline polyester resin in the binder resin composition is preferably 80% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, and 100% by mass or less.

[0091] Examples of other resins include vinyl resins such as styrene acrylic resin, polyamide resin, epoxy resin, polycarbonate resin, polyurethane resin, and composite resins containing two or more of these resins.

[0092] Furthermore, the present invention provides a toner for developing electrostatic images, which contains the binder resin composition for toners of the present invention as a binder resin.

[0093] 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 is preferably less than 100% by mass, more preferably 95% by mass or less, and even more preferably 93% by mass or less.

[0094] The toner of the present invention may contain additives such as a colorant, 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 (binder resin composition).

[0095] 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.

[0096] 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 composition.

[0097] Examples of the release agent include hydrocarbon waxes such as polypropylene wax, polyethylene wax, ethylene-propylene copolymer wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax, and oxides thereof; ester waxes such as carnauba wax, montan wax, and deacidified waxes thereof, and fatty acid ester wax; fatty acid amides, fatty acids, higher alcohols, and fatty acid metal salts, and these may be used alone or in combination of two or more.

[0098] The melting point of the release agent is preferably 60°C or higher, more preferably 70°C or higher, from the viewpoint of toner transferability, and is preferably 160°C or lower, more preferably 140°C or lower, even more preferably 120°C or lower, and even more preferably 110°C or lower, from the viewpoint of low-temperature fixability.

[0099] 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 composition, from the viewpoints of the low-temperature fixability and offset resistance of the toner and the dispersibility in the binder resin composition, 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.

[0100] 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.

[0101] 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 "VP435" (manufactured by Clariant), etc.; 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 Co., Ltd.).

[0102] 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.

[0103] 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 composition.

[0104] The toner of the present invention may be a toner obtained by any known method such as a melt-kneading pulverization method, a suspension polymerization method, a solution suspension method, an emulsion polymerization method, or an emulsion aggregation method, but from the viewpoint of low-temperature fixability and durability, a toner obtained by an emulsion aggregation method is preferred. In the case of a toner obtained by an emulsion aggregation method, for example, a binder resin composition and, if necessary, raw materials such as a colorant and a release agent are each dispersed in an aqueous medium to obtain a resin particle dispersion, a colorant particle dispersion, a release agent particle dispersion, etc., and then these are mixed, aggregated, and fused to obtain toner particles. In preparing the resin particle dispersion, the resins constituting the binder resin composition may be kneaded in advance and then dispersed in an aqueous medium, or the resins may be dispersed in the same aqueous medium, or a resin particle dispersion may be prepared for each resin and the resulting dispersions may be mixed.

[0105] In order to improve the fluidity of the toner of the present invention, it is preferable to use an external additive. Examples of the external additive include inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide, and zinc oxide, and organic fine particles such as melamine-based resin fine particles and polytetrafluoroethylene resin fine particles, and two or more of these may be used in combination. Among these, silica is preferred, and from the viewpoint of the fluidity of the toner, hydrophobic silica that has been subjected to a hydrophobic treatment is more preferred.

[0106] Examples of hydrophobic treatment agents for hydrophobizing the surfaces of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), cyclic silazanes, silicone oils, aminosilanes, octyltriethoxysilane (OTES), and methyltriethoxysilane.

[0107] From the viewpoint of the chargeability, fluidity and transferability of the toner, the average particle size of the external additive is preferably 10 nm or more, and preferably 250 nm or less, more preferably 200 nm or less, and even more preferably 90 nm or less.

[0108] The external addition treatment by mixing the toner particles with the external additives can be carried out in accordance with a conventional method, and a mixer such as a Henschel mixer can be used.

[0109] 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 4 parts by mass or less.

[0110] 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.

[0111] 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]

[0112] 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.

[0113] [Softening point of resin] Using a flow tester "CFT-500EX" (Shimadzu Corporation), 1 g of sample is heated at a temperature increase rate of 6°C / min, while a load of 1.96 MPa is applied by the plunger, and the sample is extruded from a nozzle 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.

[0114] [Resin Crystallinity Index] Using a differential scanning calorimeter "Q-20" (TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of sample is weighed into an aluminum pan and cooled to 0°C at a rate of 10°C / min. The sample is then left to stand for 1 minute, after which it is heated to 180°C at a rate of 10°C / min and the calorific value is measured. The temperature of the peak with the largest peak area among the observed endothermic peaks is taken as the endothermic maximum peak temperature, and the crystallinity index is calculated by dividing the softening point (°C) by the endothermic maximum peak temperature (°C).

[0115] [Glass transition temperature and melting point of resin] Using a differential scanning calorimeter "Q-20" (TA Instruments Japan), 0.01-0.02 g of sample is weighed into an aluminum pan, heated to 200°C at a rate of 10°C / min, and cooled to 0°C at a rate of 10°C / min. The sample is then heated at a rate of 10°C / min, and the calorific value is measured. The peak temperature with the largest peak area among the observed endothermic peaks is taken as the endothermic maximum peak temperature. For crystalline resins, this peak temperature is taken as the melting point. For amorphous resins, the glass transition temperature is taken as the temperature at the intersection of an extension of the baseline below the endothermic maximum peak temperature and a tangent line showing the maximum slope from the rising part of the peak to the peak apex.

[0116] [Acid value of resin] Measurements are made 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)) for amorphous resins, and to a mixture of chloroform and dimethylformamide (chloroform:dimethylformamide = 7:3 (volume ratio)) for crystalline resins.

[0117] [Melting point of release agent] Using a differential scanning calorimeter "Q-20" (TA Instruments Japan), 0.02 g of 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. The sample is then heated at a rate of 10°C / min, and the calorific value is measured. The maximum endothermic peak temperature is taken as the melting point.

[0118] [Volume Median Particle Diameter of Resin Particles, Colorant Particles, and Release Agent Particles] (1) Measuring device: Laser diffraction particle size measuring instrument "LA-960V2" (manufactured by Horiba, Ltd.) (2) Measurement conditions: A flow cell is used as the measurement cell, ion-exchanged water is used as the dispersion medium, and the measurement sample is added so that the absorbance is within the appropriate range. 50 ) is measured.

[0119] [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.

[0120] [Volume Median Particle Size of Toner] 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" (Beckman Coulter, Inc.) Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) Dispersion: Polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" (manufactured by Kao Corporation, 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 Corporation, output: 80 W). 25 mL of electrolyte was then added, and the mixture was further dispersed for 1 minute using the ultrasonic disperser to prepare a sample dispersion. Measurement conditions: The sample dispersion was added to 100 mL of the electrolyte to adjust the concentration so that the particle size of 30,000 particles could be measured in 20 seconds. Then, 30,000 particles were measured, and the volume median particle size (D 50 ) is found.

[0121] Resin manufacturing example 1 A 10-L four-neck flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple was purged with nitrogen. The alcohol component, terephthalic acid, esterification catalyst, and cocatalyst shown in Tables 1 and 2 were added. Under a nitrogen atmosphere, the mixture was heated to 180°C with stirring, held for 1 hour, and then heated to 220°C over 6 hours. After holding at 220°C for 1 hour, the pressure inside the flask was further reduced and held at 8.3 kPa for 0.5 hours. The pressure was then returned to atmospheric pressure, and the dodecenyl succinic anhydride shown in Tables 1 and 2 was added. The temperature was then held at 220°C for 2 hours. The pressure inside the flask was then further reduced and held at 8.3 kPa until the softening point reached the temperature shown in Tables 1 and 2. The amorphous polyester resins (Resins A1 to A3, A5 to A9) were obtained. The physical properties of the resins are shown in Tables 1 and 2.

[0122] Resin manufacturing example 2 A 10 L four-neck flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple was purged with nitrogen. The alcohol component, terephthalic acid, esterification catalyst, and cocatalyst shown in Tables 1 and 2 were added. Under a nitrogen atmosphere, the mixture was heated to 180°C with stirring, held for 1 hour, and then heated to 220°C over 6 hours. After holding at 220°C for 1 hour, the pressure inside the flask was further reduced and held at 8.3 kPa for 0.5 hours. After returning to atmospheric pressure, dodecenyl succinic anhydride shown in Tables 1 and 2 was added, and the temperature was held at 220°C for 2 hours. The temperature inside the flask was then cooled to 210°C, and trimellitic anhydride shown in Tables 1 and 2 was added, and the temperature was held at 210°C for 1 hour. The pressure inside the flask was then further reduced and held at 8.3 kPa, and the reaction was continued until the softening point reached the temperature shown in Tables 1 and 2, yielding amorphous polyester resins (Resins A4 and A10). The physical properties of the resin are shown in Tables 1 and 2.

[0123] Resin manufacturing example 3 A 10 L four-neck flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple was purged with nitrogen. The alcohol component, terephthalic acid, esterification catalyst, and cocatalyst shown in Table 2 were added. Under a nitrogen atmosphere, the mixture was heated to 180°C with stirring, held for 1 hour, and then heated to 220°C over 6 hours. After holding at 220°C for 2 hours, the pressure inside the flask was further reduced and held at 8.3 kPa for 0.5 hours. After returning to atmospheric pressure, the flask was cooled to 180°C. Fumaric acid and a polymerization inhibitor shown in Table 2 were added, and the mixture was heated to 210°C over 3 hours. After holding at 210°C for 1 hour, the pressure inside the flask was further reduced and held at 8.3 kPa until the softening point reached the temperature shown in Table 2. This gave an amorphous polyester resin (Resin A11). The physical properties of the resin are shown in Table 2.

[0124] [Table 1]

[0125] [Table 2]

[0126] Resin manufacturing example 4 A 10-liter four-neck flask equipped with a nitrogen inlet tube, dehydration tube, stirrer, and thermocouple was purged with nitrogen, and the alcohol and carboxylic acid components shown in Table 3 were added. While stirring, the temperature was raised to 135°C and maintained at 135°C for 3 hours, after which the temperature was raised from 135°C to 200°C over 10 hours. The esterification catalyst shown in Table 3 was then added, and the temperature was maintained at 200°C for another 1 hour. The pressure inside the flask was then reduced and maintained at 8.3 kPa, and the reaction was continued until the acid value reached the value shown in Table 3, yielding crystalline polyester resins (Resins C1 and C2). The physical properties of the resins are shown in Table 3.

[0127] [Table 3]

[0128] Resin particle dispersion production example 1 A 2-L four-neck flask equipped with a reflux condenser, a stirrer, and a thermocouple was charged with 200 g of Resin A shown in Table 4 and mixed with 400 g of methyl ethyl ketone (hereinafter referred to as "MEK") at room temperature to dissolve the resin. Next, a 5% by mass aqueous solution of sodium hydroxide was added so that the equivalent amount of sodium hydroxide relative to the acid value of Resin A was 65 mol %, and the mixture was stirred for 60 minutes. Next, 540 g of deionized water was added dropwise at a rate of 9 mL / min while stirring at room temperature to induce phase inversion emulsification. The temperature was then raised to 65°C, and while maintaining the temperature at 65°C, the pressure was gradually reduced from 80 kPa to 30 kPa to distill off the MEK, and some of the water was also distilled off. After cooling to room temperature, the mixture was filtered through a 150-mesh wire screen and the solids concentration was adjusted to 30% by mass with deionized water to obtain resin particle dispersions (Dispersions AE1 to AE11). The volume median particle diameter (D 50 ) are shown in Table 4.

[0129] Resin particle dispersion production example 2 A 2-L four-neck flask equipped with a reflux condenser, stirrer, and thermocouple was charged with 200 g of Resin C shown in Table 4, mixed with 400 g of MEK, and heated to 65°C with stirring to dissolve the resin. Next, while maintaining the temperature at 65°C, a 5% by mass aqueous solution of sodium hydroxide was added so that the equivalent amount of sodium hydroxide relative to the acid value of Resin C was 65 mol%, and the mixture was stirred for 60 minutes. Next, while maintaining the temperature at 65°C, 540 g of deionized water was added dropwise at a rate of 9 mL / min with stirring to cause phase inversion emulsification. Then, while maintaining the temperature at 65°C, the pressure was gradually reduced from 80 kPa to 30 kPa to distill off the MEK, and some of the water was also distilled off. After cooling to room temperature, the mixture was filtered through a 150-mesh wire net and the solids concentration was adjusted to 30% by mass with deionized water to obtain resin particle dispersions (Dispersions CE1 and CE2). The volume median particle diameter (D 50 ) are shown in Table 4.

[0130] [Table 4]

[0131] Example of manufacturing colorant particle dispersion In a 1 L beaker, 50 g of copper phthalocyanine pigment "ECB-301" (manufactured by Dainichiseika Color & Chemicals Mfg. Co., Ltd.), 66.7 g of anionic surfactant "Neopelex G-15" (manufactured by Kao Corporation, 15 mass % sodium dodecylbenzenesulfonate aqueous solution), and 184 g of deionized water were mixed and dispersed at room temperature for 3 hours using an ultrasonic homogenizer "US-600AT" (manufactured by Nippon Seiki Seisakusho Co., Ltd.), and then deionized water was added to obtain a colorant particle dispersion liquid. The volume median particle diameter (D 50 ) was 116 nm.

[0132] Example of manufacturing a release agent particle dispersion In a 1 L beaker, 3.8 g of anionic surfactant "Poise 521" (Kao Corporation, effective concentration 40% by mass, sodium acrylate-sodium maleate copolymer aqueous solution) was dissolved in 200 g of deionized water, and then 5 g of carnauba wax "Carnauba Wax No. 1" (Kato Yoko Co., Ltd., melting point 83°C) and 45 g of paraffin wax "HNP-9" (Nippon Seiro Co., Ltd., melting point 75°C) were added and melted by maintaining the temperature at 90-95°C. Next, while maintaining the temperature at 90-95°C, the mixture was dispersed for 30 minutes using an ultrasonic homogenizer "US-600AT" (Nippon Seiki Seisakusho Co., Ltd.) and then cooled to room temperature (25°C). Deionized water was added to adjust the solids concentration to 20% by mass, thereby obtaining a release agent particle dispersion. The volume median particle diameter (D 50 ) was 450 nm.

[0133] Examples 1 to 8 and Comparative Examples 1 to 3 In a 2-L four-neck flask equipped with a reflux condenser, a stirrer, and a thermocouple, 112.5 g each of the two dispersions AE and 25 g of dispersion CE shown in Table 5, 19.3 g of release agent dispersion, 22.5 g of colorant dispersion, 5.0 g of the anionic surfactant "Neopelex G-15," and 7.5 g of a 10% by mass aqueous solution of the nonionic surfactant "Emulgen (registered trademark) 150" (Kao Corporation, polyoxyethylene (50 mol) lauryl ether) were mixed at room temperature. Next, while stirring the mixture, an aqueous solution prepared by dissolving 17.2 g of ammonium sulfate in 242 g of deionized water was added dropwise over 15 minutes, and the mixture was then heated to 65°C over 2 hours and maintained at 65°C to obtain a dispersion of aggregated particles. To the resulting dispersion of aggregated particles, an aqueous solution prepared by mixing 12.1 g of anionic surfactant "EMAL E-27C" (Kao Corporation, polyoxyethylene lauryl ether sodium sulfate, effective concentration 27% by mass) and 952 g of deionized water was added. The temperature was then raised to 80°C over one hour and maintained at 80°C for one hour, thereby obtaining a dispersion of toner particles (fused particles) in which the aggregated particles were fused together.

[0134] The resulting dispersion of toner particles was cooled to room temperature, and then the dispersion was subjected to suction filtration to separate the solid content, which was then washed with deionized water and subjected to suction filtration at room temperature for 2 hours. The solid content was then vacuum dried at 40°C for 48 hours using a vacuum constant temperature dryer to determine the volume median particle diameter (D 50 ) toner particles of 5 μm were obtained.

[0135] 100 parts by mass of the obtained toner particles, 2.5 parts by mass of hydrophobic silica "RY50" (manufactured by Nippon Aerosil Co., Ltd., hydrophobic treatment agent: silicone oil, average particle size: 40 nm), and 1 part by mass of hydrophobic silica "Cabosil (registered trademark) TS720" (manufactured by Cabot Japan Co., Ltd., hydrophobic treatment agent: silicone oil, average particle size: 12 nm) were placed in a Henschel mixer, stirred, and passed through a 150-mesh sieve to obtain a toner.

[0136] [Table 5]

[0137] Test Example Toner was placed in the developing cartridge of a non-magnetic single-component developing device "Microline 5400" (manufactured by Oki Electric Industry Co., Ltd.), and the device was run at 70 r / min (equivalent to a 36-sheet machine) under conditions of a temperature of 25°C and a relative humidity of 65%, and the occurrence of streaks on the developing roll surface was visually observed every 0.5 hours, and the time until streaks occurred was measured to evaluate durability. The results are shown in Table 6. In a one-component developing device, the toner is charged by passing through the blade, but if there is a mechanically or physically weak part inside or outside the toner, the toner will stick to the blade or the developing roll, and this will cause unevenness to be observed. Therefore, the longer it takes for unevenness to appear, the more durable the toner is.

[0138] [Table 6]

[0139] From the above results, it can be seen that the toners of Examples 1 to 8 have good durability compared to the toners of Comparative Examples 1 to 3, which do not contain amorphous polyester resins using a predetermined amount of alicyclic diol and alkenyl succinic acid. [Industrial Applicability]

[0140] 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. A binder resin composition for toners containing an amorphous polyester resin and a crystalline polyester resin, wherein the amorphous polyester resin contains amorphous polyester resin A which is a polycondensate of an alcohol component containing 15 mol % to 50 mol % of an alicyclic diol and a carboxylic acid component containing 20 mol % to 45 mol % of a succinic acid derivative substituted with a hydrocarbon group having from 8 to 15 carbon atoms.

2. 2. The binder resin composition for toner according to claim 1, wherein the alcohol component of the amorphous polyester resin A further contains 50 mol % to 85 mol % of an aliphatic diol.

3. 3. The binder resin composition for toner according to claim 1, wherein the carboxylic acid component of the amorphous polyester resin A further contains 50 mol % to 80 mol % of an aromatic dicarboxylic acid compound.

4. 3. The binder resin composition for toner according to claim 1, wherein the alicyclic diol is hydrogenated bisphenol A and / or 1,4-cyclohexanedimethanol.

5. 3. The binder resin composition for toner according to claim 1, wherein the total content of the amorphous polyester resin and the crystalline polyester resin is 80% by mass or more.

6. 3. A toner for developing electrostatic images, comprising the binder resin composition for toners according to claim 1 or 2 as a binder resin.

7. 7. The toner for developing electrostatic images according to claim 6, wherein the total content of the amorphous polyester resin and the crystalline polyester resin in the binder resin composition for toner is 80% by mass or more.

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