Toner

Abstract

To provide a toner excellent in hot offset resistance and low temperature fixability after high temperature storage.SOLUTION: A toner includes, as binder resins: (A) a crystalline polyester resin; and an amorphous polyester resin (B), in which the crystalline polyester resin (A) is a condensation polymerized object of a raw material monomer (a) including: an alcohol component (A-al) including ethylene glycol, and a carboxylic acid component (A-ac) including aliphatic carboxylic acid, and the amorphous polyester resin (B) is a silicone modified polyester resin which is a reactant of a raw material monomer (b) including: an alcohol component (B-al) including bivalent or more alcohol, a carboxylic acid component (B-ac) including bivalent or more carboxylic acid, and both terminals-modified silicone.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a toner used for developing a latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method or the like. [Background technology]

[0002] In the field of electrophotography, with the development of electrophotographic systems, there is a demand for the development of toners for developing electrostatic images (hereinafter, simply referred to as "toners") that can meet the demands of higher image quality and higher speeds. In response to such demands, polyester resins have been proposed as binder resins for toners that have excellent low-temperature fixing properties. Generally, the minimum fixing temperature is in the range from the low-temperature offset occurrence temperature to the high-temperature offset occurrence temperature, so the usable temperature range of the binder resin contained in the toner is in the range from the minimum fixing temperature to the high-temperature offset occurrence temperature. Therefore, by lowering the minimum fixing temperature and raising the high-temperature offset occurrence temperature as much as possible, the usable fixing temperature can be lowered and the usable temperature range can be expanded, so that the demands for energy saving and high-speed fixing can be met. Therefore, there is a high demand for binder resins for toners and toners that are excellent in low-temperature fixing property and hot offset resistance. However, although polyester resins have excellent low-temperature fixing properties, they have a problem in that they are prone to offset phenomena. In order to solve this problem, it has been considered to provide a binder resin contained in a toner with a specific structure.

[0003] For example, Patent Document 1 describes a toner having toner particles with a core-shell structure in which a core containing a binder resin (A), a colorant, and a wax is surrounded by a shell phase containing a resin (B), and the toner particles contain 3.0 parts by mass or more and 15.0 parts by mass or less of the resin (B) relative to 100.0 parts by mass of the core, and the solubility parameter (SP value) of the binder resin (A) is SP(A) [(cal / cm 3 ) 1 / 2 ], and the SP value of the resin (B) is SP(B) [(cal / cm 3 ) 1 / 2], and the SP value of the repeating unit with the smallest SP value among the repeating units constituting the resin (B) is SP(C) [(cal / cm 3 ) 1 / 2 ], and the SP value of the wax is SP(W)[(cal / cm 3 ) 1 / 2 ], SP(A) is 9.00(cal / cm 3 ) 1 / 2 More than 12.00(cal / cm 3 ) 1 / 2 SP(W) is 7.50(cal / cm 3 ) 1 / 2 More than 9.50(cal / cm 3 ) 1 / 2 The toner is described below, characterized in that SP(A), SP(B), SP(C) and SP(W) satisfy a specific relationship. Patent Document 2 also describes a toner having toner particles containing a binder resin, a colorant, a first wax, and a second wax, wherein the binder resin contains a resin A having a polyester structural portion capable of forming a crystalline structure, the content of the polyester structural portion capable of forming a crystalline structure is 30.0% by mass or more of the binder resin, the first wax and the second wax are ester waxes having 4 or more functionalities, and the peak temperatures of the maximum endothermic peaks during the first heating measured by differential scanning calorimetry satisfy a specific relationship when the peak temperatures of the maximum endothermic peaks of the binder resin, the first wax, and the second wax are respectively T (°C), Tw1 (°C), and Tw2 (°C), and the contents of the first wax and the second wax relative to 100 parts by mass of the binder resin are respectively W1 (parts by mass) and W2 (parts by mass). Furthermore, Patent Document 3 discloses a toner having toner particles containing a binder resin, the binder resin containing 50% by mass or more of a polyester resin, the polyester resin containing a polyester resin A having a specific structure, and in an analysis of the toner particles using an X-ray photoelectron spectrometer, -(Si(R X ) 2 O) n-Si(R X ) 2 The toner is characterized in that X is the ratio of the number of silicon atoms belonging to a silicone moiety represented by - to the measured total number of atoms (number of silicon atoms / total number of atoms × 100), the value of X on the surface of the toner particle is X1, the value of X at a position 30 nm deep from the surface of the toner particle is X2, and in an analysis of the toner particles using an X-ray photoelectron spectroscopy device, Z is the ratio of the number of carbon atoms belonging to an ester bond of the polyester resin to the measured total number of atoms (number of carbon atoms / total number of atoms × 100), the value of Z on the surface of the toner particle is Z1, and the value of Z at a position 30 nm deep from the surface of the toner particle is Z2, X1 is 0.5 atomic % or more and 20.0 atomic % or less, and X1, X2, Z1, and Z2 satisfy a specific relationship. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2013-11884 A [Patent Document 2] JP 2014-109704 A [Patent Document 3] JP 2021-60582 A Summary of the Invention [Problem to be solved by the invention]

[0005] However, although the toners described in Patent Documents 1 to 3 are excellent in low-temperature fixability and / or hot offset resistance, there is still room for improvement in low-temperature fixability after high-temperature storage. Therefore, the present invention relates to a toner that is excellent in hot offset resistance and low-temperature fixability after high-temperature storage. [Means for solving the problem]

[0006] The present inventors conducted a study on the assumption that the factor affecting the low-temperature fixability of a toner after high-temperature storage is the mobility of the binder resin. As a result, they found that a toner containing, as a binder resin, a crystalline polyester resin which is a polycondensation product of a raw material monomer containing an alcohol component containing ethylene glycol and a carboxylic acid component containing an aliphatic carboxylic acid, and an amorphous polyester resin which is a reaction product of a raw material monomer containing an alcohol component containing a dihydric or higher alcohol, a carboxylic acid component containing a dihydric or higher carboxylic acid, and a silicone modified at both ends, has excellent hot offset resistance and low-temperature fixability after high-temperature storage.

[0007] That is, the present invention provides a toner containing a crystalline polyester resin (A) and an amorphous polyester resin (B) as a binder resin, the crystalline polyester resin (A) is a polycondensate of raw material monomers (a) containing an alcohol component (A-al) including ethylene glycol and a carboxylic acid component (A-ac) including an aliphatic carboxylic acid; The toner relates to a silicone-modified polyester resin, wherein the amorphous polyester resin (B) is a reaction product of a raw material monomer (b) containing an alcohol component (B-al) containing a divalent or higher alcohol, a carboxylic acid component (B-ac) containing a divalent or higher carboxylic acid, and a silicone modified at both ends. Effect of the Invention

[0008] According to the present invention, it is possible to provide a toner having excellent hot offset resistance and low-temperature fixability after high-temperature storage. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0009] [toner] A toner according to one embodiment of the present invention is a toner containing, as binder resins, a crystalline polyester resin (A) and an amorphous polyester resin (B), in which the crystalline polyester resin (A) is a polycondensate of raw material monomer (a) containing an alcohol component (A-al) containing ethylene glycol and a carboxylic acid component (A-ac) containing an aliphatic carboxylic acid, and the amorphous polyester resin (B) is a silicone-modified polyester resin which is a reaction product of raw material monomer (b) containing an alcohol component (B-al) containing a dihydric or higher alcohol, a carboxylic acid component (B-ac) containing a dihydric or higher carboxylic acid, and a silicone modified at both ends. According to the above-mentioned configuration, it is possible to provide a toner having excellent hot offset resistance and low-temperature fixability after high-temperature storage.

[0010] The reason why the present invention has an effect is not clear, but is thought to be as follows. The toner of the present invention contains a crystalline polyester resin (A) (hereinafter also referred to as "resin (A)") which is a polycondensate of raw material monomer (a) containing an alcohol component (A-al) containing ethylene glycol as a binder resin and a carboxylic acid component (A-ac) containing an aliphatic carboxylic acid. By containing a structure derived from ethylene glycol, the polarity of the resin (A) becomes closer to that of the amorphous polyester resin (B) (hereinafter also referred to as "resin (B)"), and the affinity is increased. Therefore, the compatibility between the resin (A) and the resin (B) is high, and even if the softening point of the resin (B) is relatively high, the toner can be softened at a low temperature, and the low-temperature fixability of the toner is improved. The present inventors have also found that when a toner containing a polyester resin modified with silicone having a group (hereinafter also referred to as a "reactive group") reactive with a hydroxyl group or a carboxyl group at one end as a binder resin, as described in Patent Documents 1 and 2, is stored at high temperature, the low-temperature fixability of the toner deteriorates. This is believed to be because in a polyester resin modified with silicone having a reactive group at one end, the silicone moiety has high mobility, and the low-polarity crystalline polyester resin aggregates and / or crystallizes from the silicone moiety, which also has low polarity, to generate coarse particles. On the other hand, the resin (B) contained in the toner of the present invention as a binder resin is a non-crystalline polyester resin modified with silicone having reactive groups at both ends. Since the silicone moiety is included in the main chain of the resin (B), it has low mobility compared to when the silicone moiety is present at the end of the polyester resin, and the frequency of contact between the silicone moiety and the resin (A) is reduced, so that the generation of coarse particles due to the crystallization of the resin (A) is more suppressed. Therefore, the toner has good low-temperature fixing properties even after high-temperature storage, and furthermore, the hydrophobic silicone portion exerts a releasing effect, improving hot offset resistance. Thus, it is believed that the toner of the present invention, which contains resin (A) and resin (B) as binder resins, is excellent in hot offset resistance and low-temperature fixability after high-temperature storage. The above-mentioned mechanism regarding the effect of the present invention is merely a presumption, and the present invention is not limited thereto.

[0011] The definitions of various terms used in this specification are given below. Whether a resin is crystalline or amorphous is determined by the crystallinity index. The crystallinity index is defined as the ratio of the softening point of the resin to the maximum endothermic peak temperature (softening point (°C) / maximum endothermic peak temperature (°C)) in the measurement method described in the examples below. A crystalline resin is one with a crystallinity index of 0.6 or more and 1.4 or less. An amorphous resin is one in which no endothermic peak is observed, or, if observed, has a crystallinity index of less than 0.6 or more than 1.4. The crystallinity index can be appropriately adjusted by the types and ratios of raw material monomers, as well as production conditions such as reaction temperature, reaction time, and cooling rate. In the specification, the carboxylic acid component of the polyester resin includes not only the compound itself, but also anhydrides that decompose during the reaction to produce an acid, and alkyl esters of each carboxylic acid (alkyl groups having 1 to 3 carbon atoms). Volume Median Particle Size (D 50 )" is the particle size at which the cumulative volume frequency calculated by volume fraction is 50% starting from the smallest particle size. "Bisphenol A" is 2,2-bis(4-hydroxyphenyl)propane.

[0012] The toner of the present invention contains the following crystalline polyester resin (A) and amorphous polyester resin (B) as binder resins. The toner also contains a colorant, and may further contain other components such as a release agent and a charge control agent. The toner of the present invention also preferably contains toner base particles (hereinafter also referred to as "toner particles") and an external additive externally added to the toner base particles.

[0013] [Crystalline polyester resin (A)] The crystalline polyester resin (A) is a polycondensate of raw material monomers (a) that contain an alcohol component (A-al) containing ethylene glycol and a carboxylic acid component (A-ac) containing an aliphatic carboxylic acid.

[0014] <Alcohol content (A-al)> The raw material monomer (a) contains ethylene glycol as the alcohol component (A-al).

[0015] The alcohol component (A-al) may contain an aliphatic diol in addition to ethylene glycol. The aliphatic diol has preferably 3 or more, more preferably 4 or more, and even more preferably 6 or more carbon atoms, and preferably 16 or less, more preferably 14 or less, and even more preferably 12 or less carbon atoms. Examples of the aliphatic diol include α,ω-aliphatic diols such as 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, and 1,14-tetradecanediol, and aliphatic diols other than α,ω-aliphatic diols such as 1,2-propanediol and neopentyl glycol.

[0016] From the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixing ability after high-temperature storage, the content of ethylene glycol in the alcohol component (A-al) is preferably 80 mol % or more, more preferably 85 mol % or more, even more preferably 90 mol % or more, still more preferably 95 mol % or more, and is preferably 100 mol % or less, more preferably 100 mol %.

[0017] The alcohol component (A-al) may contain other alcohols different from the aliphatic diol. Examples of other alcohols include alkylene oxide adducts of aromatic diols such as alkylene oxide adducts of bisphenol A; trihydric or higher alcohols such as glycerin, pentaerythritol, and trimethylolpropane; and long-chain monohydric alcohols such as stearyl alcohol. These alcohols may be used alone or in combination.

[0018] <Carboxylic acid component (A-ac)> The carboxylic acid component (A-ac) includes an aliphatic dicarboxylic acid.

[0019] The aliphatic dicarboxylic acid contained in the carboxylic acid component (A-ac) is preferably a straight-chain aliphatic dicarboxylic acid. The aliphatic dicarboxylic acid preferably has 8 or more carbon atoms and preferably has 16 or less carbon atoms. Preferred examples of the aliphatic dicarboxylic acid include sebacic acid, dodecanedioic acid, and tetradecanedioic acid. Among these, tetradecanedioic acid is more preferred.

[0020] From the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixing ability after high-temperature storage, the content of the aliphatic dicarboxylic acid in the carboxylic acid component (A-ac) is preferably 75 mol % or more, more preferably 80 mol % or more, even more preferably 85 mol % or more, and is preferably 98 mol % or less, more preferably 95 mol % or less, even more preferably 93 mol % or less.

[0021] The carboxylic acid component (A-ac) may contain other carboxylic acids different from the aliphatic dicarboxylic acids. Examples of other carboxylic acids include aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid; polycarboxylic acids having three or more valences; and aliphatic monocarboxylic acids. These carboxylic acids may be used alone or in combination.

[0022] As the aliphatic monocarboxylic acid, from the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixing property after high-temperature storage, an aliphatic monocarboxylic acid having 16 to 22 carbon atoms is preferable, and a straight-chain aliphatic monocarboxylic acid having 16 to 22 carbon atoms is more preferable. Preferred examples of the aliphatic monocarboxylic acid having 16 to 22 carbon atoms include decanoic acid, undecanoic acid, dodecanoic acid (lauric acid), tridecanoic acid, tetradecanoic acid (myristic acid), pentadecanoic acid, hexadecanoic acid (palmitic acid), heptadecanoic acid (margaric acid), octadecanoic acid (stearic acid), nonadecanoic acid, eicosanoic acid (arachidic acid), heneicosanoic acid, and docosanoic acid (behenic acid). Among these, stearic acid is more preferred.

[0023] From the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixing ability after high-temperature storage, the content of the aliphatic monocarboxylic acid in the carboxylic acid component (A-ac) is preferably 2 mol % or more, more preferably 5 mol % or more, even more preferably 7 mol % or more, and is preferably 25 mol % or less, more preferably 20 mol % or less, even more preferably 15 mol % or less.

[0024] The equivalent ratio of the carboxyl group of the carboxylic acid component (A-ac) to the hydroxyl group of the alcohol component (A-al) in the raw material monomer (a) [COOH group / OH group] is preferably 0.8 or more, more preferably 0.9 or more, and is preferably 1.2 or less, more preferably 1.1 or less.

[0025] (Method for producing resin (A)) The resin (A) is produced, for example, by a method of polycondensing a raw material monomer (a). In the polycondensation reaction, if necessary, an esterification catalyst such as tin(II) di(2-ethylhexanoate), dibutyltin oxide, or titanium diisopropylate bistriethanolamine may be used in an amount of 0.01 to 5 parts by mass per 100 parts by mass of the total amount of aliphatic diol, aliphatic dicarboxylic acid, aliphatic monoalcohol, and aliphatic monocarboxylic acid; or an esterification promoter such as gallic acid (same as 3,4,5-trihydroxybenzoic acid) may be used in an amount of 0.001 to 0.5 parts by mass per 100 parts by mass of the total amount of aliphatic diol, aliphatic dicarboxylic acid, aliphatic monoalcohol, and aliphatic monocarboxylic acid. When a monomer having an unsaturated bond such as fumaric acid is used for polycondensation, a radical polymerization inhibitor may be used, if necessary, in an amount of preferably 0.001 to 0.5 parts by mass per 100 parts by mass of the total amount of the alcohol component (A-al) and the carboxylic acid component (A-ac). An example of the radical polymerization inhibitor is 4-tert-butylcatechol. The reaction temperature is preferably 120° C. or higher, more preferably 160° C. or higher, even more preferably 180° C. or higher, and is preferably 250° C. or lower, more preferably 240° C. or lower. The reaction may be carried out in an inert gas atmosphere.

[0026] (Physical properties of resin (A)) From the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixing ability after high-temperature storage, the acid value of the resin (A) is preferably 1 mgKOH / g or more, more preferably 3 mgKOH / g or more, and is preferably 20 mgKOH / g or less, more preferably 15 mgKOH / g or less, and even more preferably 10 mgKOH / g or less.

[0027] From the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixing ability after high-temperature storage, the melting point of the resin (A) is preferably 70° C. or higher, more preferably 75° C. or higher, even more preferably 80° C. or higher, and is preferably 105° C. or lower, more preferably 100° C. or lower, even more preferably 95° C. or lower. From the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixing ability after high-temperature storage, the softening point of the resin (A) is preferably 70° C. or higher, more preferably 75° C. or higher, even more preferably 80° C. or higher, and is preferably 105° C. or lower, more preferably 100° C. or lower, even more preferably 95° C. or lower.

[0028] The acid value, melting point, and softening point of the resin (A) can be appropriately adjusted by the type and amount of the raw material monomer (a) used, as well as production conditions such as reaction temperature, reaction time, and cooling rate, and are determined by the method described in the Examples below. When two or more types of resin (A) are used in combination, the acid value, melting point, and softening point of the resin (A) obtained as a mixture thereof are preferably within the above-mentioned ranges.

[0029] In the toner, the content of the resin (A) in the binder resin is preferably 1% by mass or more, more preferably 3% by mass or more, and preferably 20% by mass or less, more preferably 10% by mass or less, from the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixability after high-temperature storage.

[0030] [Amorphous polyester resin (B)] The amorphous polyester resin (B) is a silicone-modified polyester resin which is a reaction product of raw material monomer (b) containing an alcohol component (B-al) containing a divalent or higher alcohol, a carboxylic acid component (B-ac) containing a divalent or higher carboxylic acid, and a silicone modified at both ends.

[0031] <Alcohol content (B-al)> The alcohol component (B-al) includes dihydric or higher alcohols. The content of the dihydric or higher alcohol in the alcohol component (B-al) is preferably 80 mass % or more, more preferably 90 mass % or more, and further preferably 95 mass % or more, and 100 mass % or less. Examples of the dihydric or higher alcohol include alkylene oxide adducts of aromatic diols, linear or branched aliphatic diols, alicyclic diols, and trihydric or higher polyhydric alcohols. Among these, alkylene oxide adducts of aromatic diols and linear or branched aliphatic diols are preferred, and alkylene oxide adducts of aromatic diols are more preferred.

[0032] The alkylene oxide adduct of an aromatic diol is preferably an alkylene oxide adduct of bisphenol A, more preferably an alkylene oxide adduct of formula (I):

[0033] [ka] (In the formula, OR 1 and R 2 O is an oxyalkylene group, and R 1 and R 2 are each independently an ethylene group or a propylene group, x and y are each an average number of moles of alkylene oxide added and are each a positive number, and the sum of x and y is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, and more preferably 4 or less. Examples of the alkylene oxide adduct of bisphenol A include a propylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol A. One or more of these may be used. Among these, a propylene oxide adduct of bisphenol A, an ethylene oxide adduct of bisphenol A, and a combination of a propylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol A are preferred, and a combination of a propylene oxide adduct of bisphenol A and an ethylene oxide adduct of bisphenol A is more preferred. When the alcohol component (B-al) contains an alkylene oxide adduct of bisphenol A, the amount thereof in the alcohol component (B-al) is preferably 70 mol % or more, more preferably 90 mol % or more, even more preferably 95 mol % or more, and is 100 mol % or less, even more preferably 100 mol %.

[0034] As the linear or branched aliphatic diol, an aliphatic diol having a hydroxyl group bonded to a secondary carbon atom is preferred. The aliphatic diol having a hydroxyl group bonded to a secondary carbon atom preferably has 3 or more and 4 or less carbon atoms. Examples of aliphatic diols having a hydroxyl group bonded to a secondary carbon atom include 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, and 2,3-butanediol.

[0035] Other linear or branched aliphatic diols include, for example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, and neopentyl glycol.

[0036] Examples of alicyclic diols include hydrogenated bisphenol A [2,2-bis(4-hydroxycyclohexyl)propane] and adducts of hydrogenated bisphenol A with alkylene oxides having 2 to 4 carbon atoms (average number of moles added: 2 to 12). Examples of trihydric or higher polyhydric alcohols include glycerin, pentaerythritol, trimethylolpropane, and sorbitol. These alcohols may be used alone or in combination of two or more.

[0037] <Carboxylic acid component (B-ac)> The carboxylic acid component (B-ac) includes divalent or higher carboxylic acids, such as dicarboxylic acids and trivalent or higher polyvalent carboxylic acids. The content of the divalent or higher carboxylic acid in the carboxylic acid component (B-ac) is preferably 80 mol % or more, more preferably 90 mol % or more, and further preferably 95 mol % or more, and 100 mol % or less. Examples of divalent or higher carboxylic acids include aromatic dicarboxylic acids, linear or branched aliphatic dicarboxylic acids, alicyclic dicarboxylic acids, and trivalent or higher polycarboxylic acids. Among these, aromatic dicarboxylic acids are preferred.

[0038] Examples of aromatic dicarboxylic acids include phthalic acid, isophthalic acid, and terephthalic acid. Among these, isophthalic acid and terephthalic acid are preferred, and terephthalic acid is more preferred. The amount of aromatic dicarboxylic acid in the carboxylic acid component (B-ac) is preferably 55 mol% or more, more preferably 60 mol% or more, even more preferably 65 mol% or more, and preferably 85 mol% or less, more preferably 80 mol% or less, even more preferably 75 mol% or less.

[0039] The linear or branched aliphatic dicarboxylic acid has preferably 2 or more, more preferably 4 or more, even more preferably 8 or more, even more preferably 10 or more carbon atoms, and preferably 22 or less, more preferably 16 or less. Examples of linear or branched aliphatic dicarboxylic acids include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, succinic acid, adipic acid, sebacic acid, dodecanedioic acid, tetradecanedioic acid, and succinic acid substituted with an aliphatic hydrocarbon group having 1 to 20 carbon atoms. Examples of succinic acid substituted with an aliphatic hydrocarbon group having 1 to 20 carbon atoms include dodecylsuccinic acid, dodecenylsuccinic acid, and octenylsuccinic acid. Among these, dodecenylsuccinic acid is preferred. When a linear or branched aliphatic dicarboxylic acid is contained, the amount thereof in the carboxylic acid component (B-ac) is preferably 1 mol % or more, more preferably 3 mol % or more, even more preferably 5 mol % or more, and preferably 15 mol % or less, more preferably 10 mol % or less.

[0040] The trivalent or higher polyvalent carboxylic acid is preferably a trivalent carboxylic acid, such as trimellitic acid. Of these, trimellitic acid is preferred. When a trivalent or higher polyvalent carboxylic acid is contained, the amount of the trivalent or higher polyvalent carboxylic acid in the carboxylic acid component (B-ac) is preferably 10 mol% or more, more preferably 15 mol% or more, even more preferably 20 mol% or more, and preferably 40 mol% or less, more preferably 35 mol% or less, even more preferably 30 mol% or less. These carboxylic acids may be used alone or in combination of two or more.

[0041] The ratio of the carboxyl groups of the carboxylic acid component (B-ac) to the hydroxyl groups of the alcohol component (B-al) (COOH groups / OH groups) is preferably 0.7 or more, more preferably 0.8 or more, and is preferably 1.2 or less, more preferably 1.1 or less.

[0042] <Both end-modified silicone> The silicone modified at both ends used in the resin (B) is a modified silicone having a group reactive with a hydroxyl group or a carboxyl group at both ends, preferably a modified silicone having at least one group selected from an amino group, a carboxyl group, an epoxy group, and a group containing a hydroxyl group at both ends, from the viewpoint of obtaining a toner excellent in hot offset resistance and low-temperature fixing property after high-temperature storage. The groups reactive with a hydroxyl group or a carboxyl group may be the same or different.

[0043] The both-end-modified silicone preferably has a repeating unit represented by formula (1) and a structure represented by formula (2).

[0044] [ka] [In formula (1), each R is independently a hydrocarbon group having 1 to 6 carbon atoms, and * is a bonding site.]

[0045] *-SiR 3-a (R'-X) a (2) [In formula (2), R is each independently a hydrocarbon group having 1 to 6 carbon atoms, R' is each independently an alkylene group having 1 to 10 carbon atoms, a is an integer of 1 to 3, X is each independently a group containing an amino group, a carboxy group, an epoxy group, or a hydroxy group, and * is a bonding site with the repeating unit represented by formula (1)]

[0046] In formula (1) and formula (2), the hydrocarbon group of R has 6 or less carbon atoms, preferably 4 or less, more preferably 3 or less, even more preferably 2 or less, and even more preferably 1 carbon atom. Examples of the hydrocarbon group for R include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a tert-butyl group, a pentyl group, and a phenyl group. Among these, a methyl group is preferable.

[0047] In formula (2), the alkylene group of R' has 10 or less carbon atoms, preferably 8 or less, more preferably 5 or less, even more preferably 4 or less, still more preferably 3 or less, and preferably 1 or more. Examples of the alkylene group of R' include methanediyl, ethane-1,2-diyl, ethane-1,1-diyl, n-propane-1,3-diyl, and n-propane-1,2-diyl. Among these, methanediyl, ethane-1,2-diyl, n-propane-1,3-diyl, and n-propane-1,2-diyl are preferred.

[0048] Each X is independently a group containing an amino group, a carboxy group, an epoxy group, or a hydroxy group, and is preferably an amino group, a hydroxy group, a hydroxyalkyloxy group, a carboxy group, a carboxyalkyloxy group, an epoxy group, a glycidyl group, a glycidyloxy group, or an alicyclic epoxy group. The hydroxyalkyloxy group may have a plurality of hydroxy groups, and the carboxyalkyloxy group may have a plurality of carboxy groups. Among them, from the viewpoint of reactivity with the carboxy group of a divalent or higher carboxylic acid, X is preferably a group containing an amino group.

[0049] The functional group equivalent of the both-end-modified silicone is preferably 300 g / mol or more, more preferably 500 g / mol or more, even more preferably 800 g / mol or more, and preferably 10,000 g / mol or less, more preferably 8,000 g / mol or less, even more preferably 6,000 g / mol or less, even more preferably 4,000 g / mol or less. The functional group equivalent weight means the mass of the silicone modified at both ends per mol of functional group.

[0050] The kinetic viscosity of the double-end modified silicone is preferably 10 mm at 25°C. 2 / s or more, preferably 30 mm 2 / s or more, more preferably 40 mm 2 / s or more, and preferably 1,000 mm 2 / s or less, preferably 800 mm2 / s or less, more preferably 600 mm 2 / s or less. The kinetic viscosity of the both end-modified silicone can be measured, for example, using a fully automatic microkinetic viscometer (manufactured by Viscotec Co., Ltd.).

[0051] Examples of the above-mentioned double-end modified silicone include modified silicones having amino groups at both ends (commercially available products include, for example, "KF-8008", "KF-8010", "KF-8012", "X-22-161A", and "X-22-161B" (manufactured by Shin-Etsu Chemical Co., Ltd.)), modified silicones having carboxy groups at both ends (commercially available products include, for example, "X-22-162C" (manufactured by Shin-Etsu Chemical Co., Ltd.)), modified silicones having epoxy groups at both ends (commercially available products include, for example, "X-22-163A", "X-22-163B", "X-22-163C", "X-22-169AS", and "X-22-169B" (manufactured by Shin-Etsu Chemical Co., Ltd.)), and modified silicones having hydroxy groups at both ends (commercially available products include, for example, "KF-6001", "KF-6002", and "KF-6003" (manufactured by Shin-Etsu Chemical Co., Ltd.)).

[0052] When the both-end-modified silicone is a modified silicone having groups containing amino groups at both ends, examples of the group represented by -(R'-X) in the structure represented by formula (2) include the following substituents 1a-1 to 1a-3.

[0053] [ka]

[0054] When the double-end-modified silicone is a modified silicone having groups containing hydroxy groups at both ends, examples of the group represented by -(R'-X) in the structure represented by formula (2) include the following substituents 1b-1 to 1b-3. Among these, the substituent 1b-1 or the substituent 1b-2 is preferred, and the substituent 1b-1 is more preferred.

[0055] [ka]

[0056] When the double-end-modified silicone is a modified silicone having groups containing epoxy groups at both ends, in the structure represented by formula (2), X is preferably a glycidyl group, a glycidyloxy group, or an alicyclic epoxy group, and examples of the group represented by -(R'-X) include the following substituents 1c-1 to 1c-3. Among these, the substituent 1c-1 is preferred.

[0057] [ka]

[0058] When the both-end-modified silicone is a modified silicone having groups containing a carboxy group at both ends, in the structure represented by formula (2), X is preferably a carboxy group or a carboxyalkyloxy group, and examples of the group represented by -(R'-X) include the following substituent 1d-1.

[0059] [ka]

[0060] (Method for producing resin (B)) Resin (B) is produced, for example, by a method of polycondensing an alcohol component (B-al), a carboxylic acid component (B-ac), and a silicone modified at both ends. The alcohol component (B-al), the carboxylic acid component (B-ac), and the silicone modified at both ends may be reacted all at once, or the alcohol component (B-al) may be reacted with the carboxylic acid component (B-ac) and then reacted with the silicone modified at both ends, and there is no particular limitation. The esterification catalyst, esterification promoter, and radical polymerization inhibitor used in the reaction may be the same as those described in the method for producing resin (A). The reaction conditions may also be the same as those described in the method for producing resin (A).

[0061] From the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixing property after high-temperature storage, the amount of the silicone modified at both ends in the resin (B) is preferably 1 part by mass or more, more preferably 2 parts by mass or more, even more preferably 3 parts by mass or more, relative to 100 parts by mass in total of the alcohol component (B-al) and the carboxylic acid component (B-ac) in the raw material monomer (b), and is preferably 20 parts by mass or less, more preferably 16 parts by mass or less, and even more preferably 14 parts by mass or less.

[0062] In addition, when the silicone modified at both ends has a hydroxy group or a carboxy group, it can be understood as an alcohol component (B-al) or a carboxylic acid component (B-ac), but when a compound having a hydroxy group or a carboxy group at both ends contains a silicone skeleton, it is called a silicone modified at both ends. For example, when calculating the total amount of the alcohol component (B-al) and the carboxylic acid component (B-ac), the modified silicone having a hydroxy group or a carboxy group at both ends is not included in these total amounts.

[0063] (Physical properties of resin (B)) The acid value of the resin (B) is preferably 1 mgKOH / g or more, more preferably 5 mgKOH / g or more, even more preferably 10 mgKOH / g or more, and is preferably 40 mgKOH / g or less, more preferably 30 mgKOH / g or less, even more preferably 20 mgKOH / g or less.

[0064] The glass transition temperature of resin (B) is preferably 50° C. or higher, more preferably 55° C. or higher, and even more preferably 60° C. or higher, and from the viewpoint of further improving low-temperature fixability, is preferably 80° C. or lower, more preferably 75° C. or lower, and even more preferably 70° C. or lower. From the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixing ability after high-temperature storage, the softening point of resin (B) is preferably 110° C. or higher, more preferably 115° C. or higher, even more preferably 120° C. or higher, and is preferably 140° C. or lower, more preferably 135° C. or lower, even more preferably 130° C. or lower.

[0065] The acid value, glass transition temperature, and softening point of the resin (B) can be appropriately adjusted by the type and amount of the raw material monomer, as well as production conditions such as reaction temperature, reaction time, cooling rate, etc., and are determined by the method described in the Examples below. When two or more types of resin (B) are used in combination, it is preferable that the acid value, glass transition temperature, and softening point of the resin (B) obtained as a mixture thereof are each within the above-mentioned ranges.

[0066] In the toner, the content of resin (B) in the binder resin is preferably 30% by mass or more, more preferably 35% by mass or more, from the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixing property after high-temperature storage, and is preferably 99% by mass or less, more preferably 97% by mass or less.

[0067] The toner of the present invention may further contain other resins such as crystalline polyester resins and non-crystalline polyester resins as binder resins. The crystalline polyester resins include crystalline polyester resins other than the resin (A). The non-crystalline polyester resins include non-crystalline polyester resins (C) other than the resin (B).

[0068] [Amorphous polyester resin (C)] From the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixability after high-temperature storage, the toner of the present invention preferably contains an amorphous polyester resin (C) (hereinafter also referred to as "resin (C)") as a binder resin. From the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixing ability after high-temperature storage, it is preferable that resin C is a resin having a softening point different from that of resin B, and it is more preferable to use resin B having a high softening point in combination with resin C having a low softening point that is 5° C. or more lower than that of resin B. From the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixing ability after high-temperature storage, the difference in softening point between resin B and resin C is preferably 5° C. or more, more preferably 10° C. or more, and is preferably 50° C. or less, more preferably 30° C. or less, and even more preferably 20° C. or less. When resin B and resin C are used in combination, the mass ratio of resin C to resin B (resin C / resin B) is, from the viewpoint of obtaining a toner having excellent hot offset resistance and low-temperature fixing ability after high-temperature storage, preferably 1 / 99 or more, more preferably 5 / 95 or more, even more preferably 10 / 90 or more, and is preferably 70 / 30 or less, more preferably 60 / 40 or less, even more preferably 50 / 50 or less, even more preferably 40 / 60 or less.

[0069] Examples of the resin (C) include polyester resins having a softening point 5°C or more lower than that of the resin (B), modified polyester resins, etc. Examples of the polyester resin include polyester resins that are polycondensates of the alcohol component (B-al) and the carboxylic acid component (B-ac) listed in the resin (B). Examples of the modified polyester resin include urethane modified polyester resins, epoxy modified polyester resins, and composite resins containing polyester resin segments and addition polymerization resin segments. Among these, composite resins (C1) containing polyester resin segments and addition polymerization resin segments are preferred.

[0070] (Composite resin (C1)) Examples of the alcohol component of the polyester resin segment of the composite resin (C1) include alkylene oxide adducts of aromatic diols, linear or branched aliphatic diols, alicyclic diols, and trihydric or higher polyhydric alcohols.

[0071] Examples of the alkylene oxide adduct of an aromatic diol include the alkylene oxide adduct of bisphenol A represented by formula (I) in the above-mentioned resin (B), and the preferred range is also the same. The content of the alkylene oxide adduct of bisphenol A in the alcohol component is preferably 80 mol % or more, more preferably 90 mol % or more, even more preferably 95 mol % or more, and is 100 mol % or less, more preferably 100 mol %.

[0072] Examples of the linear or branched aliphatic diol, alicyclic diol, and trihydric or higher polyhydric alcohol include the linear or branched aliphatic diol, alicyclic diol, and trihydric or higher polyhydric alcohol described above for resin (B), and the preferred ranges are also the same.

[0073] Examples of the carboxylic acid component of the polyester resin segment of the composite resin (C1) include the carboxylic acid component (B-ac) exemplified in the resin (B) described above. Specific examples include aromatic dicarboxylic acid compounds, aliphatic dicarboxylic acid compounds, and tri- or higher carboxylic acid compounds. The amount of aromatic dicarboxylic acid in the carboxylic acid component is preferably 35 mol% or more, more preferably 40 mol% or more, even more preferably 45 mol% or more, and preferably 70 mol% or less, more preferably 65 mol% or less, even more preferably 60 mol% or less.

[0074] The amount of aliphatic dicarboxylic acid in the carboxylic acid component is preferably 5 mol% or more, more preferably 10 mol% or more, even more preferably 15 mol% or more, and preferably 35 mol% or less, more preferably 30 mol% or less, even more preferably 25 mol% or less.

[0075] When a trivalent or higher polycarboxylic acid is contained, the amount of the trivalent or higher polycarboxylic acid in the carboxylic acid component is preferably 10 mol% or more, more preferably 15 mol% or more, even more preferably 20 mol% or more, and is preferably 40 mol% or less, more preferably 35 mol% or less, even more preferably 30 mol% or less. These carboxylic acid components may be used alone or in combination of two or more.

[0076] 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, and is preferably 1.2 or less, more preferably 1.1 or less.

[0077] An example of the addition polymerized resin segment of the composite resin (C1) is an addition polymer of raw material monomers containing a styrene-based compound. Examples of the styrene-based compound include unsubstituted or substituted styrene. Examples of the substituent substituted on styrene include an alkyl group having 1 to 5 carbon atoms, a halogen atom, an alkoxy group having 1 to 5 carbon atoms, a sulfonic acid group, or a salt thereof. Examples of styrene-based compounds include styrene, methylstyrene, α-methylstyrene, β-methylstyrene, tert-butylstyrene, chlorostyrene, chloromethylstyrene, methoxystyrene, styrenesulfonic acid, and salts thereof. Among these, styrene is preferred. In the raw material monomers of the addition polymerization resin segment, the content of the styrene-based compound is preferably 70 mass% or more, more preferably 75 mass% or more, even more preferably 80 mass% or more, and preferably 95 mass% or less, more preferably 90 mass% or less, even more preferably 88 mass% or less.

[0078] Examples of raw material monomers other than styrene-based compounds include (meth)acrylic acid esters such as alkyl (meth)acrylate, benzyl (meth)acrylate, and dimethylaminoethyl (meth)acrylate; olefins such as ethylene, propylene, and butadiene; halovinyls such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as methyl vinyl ether; vinylidene halides such as vinylidene chloride; and N-vinyl compounds such as N-vinylpyrrolidone. Among these, (meth)acrylic acid esters are preferred, and alkyl (meth)acrylates are more preferred. The number of carbon atoms in the alkyl group in the alkyl (meth)acrylate is preferably 1 or more, more preferably 4 or more, even more preferably 6 or more, and is preferably 24 or less, more preferably 22 or less, even more preferably 20 or less. Examples of the alkyl (meth)acrylate include methyl (meth)acrylate, ethyl (meth)acrylate, (iso)propyl (meth)acrylate, (iso or tertiary)butyl (meth)acrylate, (iso)amyl (meth)acrylate, cyclohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (iso)octyl (meth)acrylate, (iso)decyl (meth)acrylate, (iso)dodecyl (meth)acrylate, (iso)palmityl (meth)acrylate, (iso)stearyl (meth)acrylate, and (iso)behenyl (meth)acrylate. Of these, 2-ethylhexyl (meth)acrylate or stearyl (meth)acrylate is preferred, 2-ethylhexyl (meth)acrylate is more preferred, and 2-ethylhexyl acrylate is even more preferred.

[0079] In the raw material monomers of the addition polymerization resin segment, the content of the (meth)acrylic acid ester is preferably 5 mass% or more, more preferably 10 mass% or more, even more preferably 12 mass% or more, and preferably 30 mass% or less, more preferably 25 mass% or less, even more preferably 20 mass% or less. The total amount of the styrene-based compound and the (meth)acrylic acid ester in the raw material monomers of the addition polymerization resin segment is preferably 80 mass % or more, more preferably 90 mass % or more, even more preferably 95 mass % or more, and even more preferably 100 mass %.

[0080] The composite resin (C1) preferably has a constitutional unit derived from a bireactive monomer bonded via a covalent bond to a polyester resin segment and an addition polymerization resin segment. The term "structural unit derived from a bireactive monomer" refers to a unit formed by reaction of a functional group and an addition polymerizable group of a bireactive monomer. An example of the addition polymerizable group is a carbon-carbon unsaturated bond (ethylenically unsaturated bond). Examples of the bireactive monomer include addition polymerizable monomers having at least one functional group selected from a hydroxyl group, a carboxyl group, an epoxy group, a primary amino group, and a secondary amino group in the molecule. Among these, from the viewpoint of reactivity, addition polymerizable monomers having at least one functional group selected from a hydroxyl group and a carboxyl group are preferred, and addition polymerizable monomers having a carboxyl group are more preferred. Examples of the addition polymerizable monomer having a carboxy group include acrylic acid, methacrylic acid, fumaric acid, and maleic acid. Among these, from the viewpoint of reactivity in both the polycondensation reaction and the addition polymerization reaction, acrylic acid and methacrylic acid are preferred, and acrylic acid is more preferred. When the bireactive monomer is an addition polymerizable monomer having a carboxy group, the amount of the constitutional units derived from the bireactive monomer is preferably 1 mol part or more, more preferably 1.5 mol parts or more, even more preferably 2 mol parts or more, and preferably 10 mol parts or less, more preferably 8 mol parts or less, even more preferably 5 mol parts or less, relative to 100 mol parts of the alcohol component of the polyester resin segment of Resin B1.

[0081] The content of the polyester resin segment in the composite resin (C1) is preferably 70 mass% or more, more preferably 75 mass% or more, even more preferably 80 mass% or more, and preferably 95 mass% or less, more preferably 90 mass% or less, even more preferably 88 mass% or less.

[0082] The content of the addition polymerization resin segment in the composite resin (C1) is preferably 5 mass% or more, more preferably 10 mass% or more, even more preferably 12 mass% or more, and preferably 30 mass% or less, more preferably 25 mass% or less, even more preferably 20 mass% or less.

[0083] The amount of the structural units derived from the bireactive monomer in the composite resin (C1) is preferably 0.1 mass% or more, more preferably 0.2 mass% or more, even more preferably 0.25 mass% or more, and preferably 5 mass% or less, more preferably 3 mass% or less, even more preferably 1 mass% or less.

[0084] In the composite resin (C1), the total amount of the polyester resin segment, the addition polymerization resin segment, and the structural units derived from the bireactive monomer is preferably 80 mass% or more, more preferably 90 mass% or more, even more preferably 95 mass% or more, and is 100 mass% or less, even more preferably 100 mass%.

[0085] In the composite resin (C1), the mass ratio of the polyester resin segment to the addition polymerization resin segment (polyester resin segment / addition polymerization resin segment) is preferably 2 or more, more preferably 3 or more, even more preferably 4 or more, and is preferably 20 or less, more preferably 10 or less, even more preferably 7 or less.

[0086] The above amount is calculated based on the ratio of the amounts of the polyester resin segment, the raw material monomer for the addition polymerization resin segment, the bireactive monomer, and the radical polymerization initiator, and the mass of the polyester resin segment, etc. is based on the mass excluding the mass of water generated by polycondensation. When a radical polymerization initiator is used, the mass of the radical polymerization initiator is calculated by including it in the addition polymerization resin segment.

[0087] (Production method of composite resin (C1)) The composite resin (C1) may be produced, for example, by a method including a step A of polycondensing an alcohol component and a carboxylic acid component, and a step B of addition polymerizing raw material monomers of the addition polymerization resin segment and a bireactive monomer. Step B may be carried out after step A, step B may be carried out after step A, or step A and step B may be carried out simultaneously. A method is preferred in which a part of the carboxylic acid component is subjected to a polycondensation reaction in step A, and then step B is carried out, and thereafter the remainder of the carboxylic acid component is added to the polymerization system to further proceed with the polycondensation reaction in step A and the polycondensation reaction with the carboxy group of the bireactive monomer or the constituent moiety derived from the bireactive monomer.

[0088] In the step A, if necessary, the esterification catalyst and the esterification promoter described in the above production method for the resin (B) may be used in the same amounts to carry out polycondensation. When a monomer having an unsaturated bond such as fumaric acid is used in the polycondensation, the polymerization inhibitor described in the production method of the resin (B) may be used in the same amount as above, if necessary. The temperature of the polycondensation reaction is preferably 120° C. or higher, more preferably 160° C. or higher, and even more preferably 180° C. or higher, and is preferably 250° C. or lower, more preferably 240° C. or lower. The polycondensation may be carried out in an inert gas atmosphere.

[0089] Examples of the radical polymerization initiator for the addition polymerization in step B include peroxides such as di-tert-butyl peroxide, persulfates such as sodium persulfate, and azo compounds such as 2,2'-azobis(2,4-dimethylvaleronitrile). The amount of the radical polymerization initiator used is preferably 1 part by mass or more and 20 parts by mass or less based on 100 parts by mass of the raw material monomer of the addition polymerization resin segment. The temperature of the addition polymerization is preferably 110° C. or higher, more preferably 130° C. or higher, and preferably 230° C. or lower, more preferably 220° C. or lower, and further preferably 210° C. or lower.

[0090] (Physical properties of composite resin (C1)) The softening point of the composite resin (C1) is at least 5°C lower than the softening point of the resin (B), and is preferably at least 80°C, more preferably at least 90°C, and even more preferably at least 95°C. From the viewpoint of further improving low-temperature fixability, it is preferably at most 130°C, more preferably at most 125°C, and even more preferably at most 120°C. The glass transition temperature and acid value of the composite resin (C1) may be in the same range as those of the resin (B).

[0091] The softening point, glass transition temperature, and acid value of the composite resin (C1) can be appropriately adjusted by the type and amount of the raw material monomer, as well as production conditions such as reaction temperature, reaction time, and cooling rate, and these values ​​can be determined by the method described in the examples. When two or more types of composite resins (C1) are used in combination, the softening point, glass transition temperature, and acid value of the mixture thereof preferably fall within the above-mentioned ranges.

[0092] <Coloring agent> As the colorant, any of the dyes, pigments, etc. used as colorants for toners can be used, such as carbon black, phthalocyanine blue, permanent brown FG, brilliant fast scarlet, pigment green B, rhodamine B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, disazo yellow, etc. can be used, and the toner of the present invention may be either a black toner or another color toner.

[0093] From the viewpoint of improving the image density of the toner, the content of the colorant is preferably 0.3 parts by mass or more, more preferably 1 part by mass or more, and even more preferably 2 parts by mass or more, relative to 100 parts by mass of the total amount of the binder resin, and is preferably 20 parts by mass or less, more preferably 10 parts by mass or less, and even more preferably 5 parts by mass or less.

[0094] <Release agent> Examples of the release agent include hydrocarbon wax, ester wax, silicone wax, and fatty acid amide wax.

[0095] The melting point of the release agent is preferably 60° C. or higher, more preferably 70° C. or higher, and preferably 160° C. or lower, more preferably 150° C. or lower, and further preferably 140° C. or lower. When two or more types of release agents are used in combination, it is preferable that the melting points of the respective release agents are within the above-mentioned range.

[0096] The content of the release agent is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and even more preferably 0.5 parts by mass or more, relative to 100 parts by mass of the total amount of the binder resin, and is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and even more preferably 3 parts by mass or less.

[0097] <Charge control agent> The charge control agent may contain either a positively chargeable charge control agent or a negatively chargeable charge control agent. Examples of the positively charged charge control agent include nigrosine dyes such as "Nigrosine Base EX", "Oil Black BS", "Oil Black SO", "Bontron N-01", "Bontron N-04", "Bontron N-07", "Bontron N-09", "Bontron N-11", and "Bontron N-79" (all manufactured by Orient Chemical Industry Co., Ltd.); triphenylmethane dyes containing tertiary amines as side chains, quaternary ammonium salt compounds such as "Bontron P-51" (manufactured by Orient Chemical Industry Co., Ltd.), cetyltrimethylammonium bromide, "COPY CHARGE PX VP435" (manufactured by Clariant); polyamine resins such as "AFP-B" (manufactured by Orient Chemical Industry Co., Ltd.); imidazole derivatives such as "PLZ-2001" and "PLZ-8001" (manufactured by Shikoku Chemical Industry Co., Ltd.); and styrene-acrylic resins such as "FCA-701PT" (manufactured by Fujikura Chemical Industry Co., Ltd.).

[0098] Examples of negatively chargeable charge control agents include metal-containing azo dyes such as "Varifast Black 3804", "Bontron S-31", "Bontron S-32", "Bontron S-34", and "Bontron S-36" (all manufactured by Orient Chemical Industry Co., Ltd.), "Aizen Spiron Black TRH", and "T-77" (manufactured by Hodogaya Chemical Industry Co., Ltd.); metal compounds of benzilic acid compounds such as "LR-147" and "LR-297" (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 Industry Co., Ltd.), and "TN-105" (manufactured by Hodogaya Chemical Industry Co., Ltd.); copper phthalocyanine dyes; quaternary ammonium salts such as "COPY CHARGE NX VP434" (manufactured by Clariant), nitroimidazole derivatives, and organometallic compounds. The charge control agent to be used may be appropriately selected depending on the characteristics of the printer in which the toner is used, the type of colorant, and the like.

[0099] 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, even more preferably 0.5 parts by mass or more, and is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, relative to 100 parts by mass of the total amount of the binder resin.

[0100] [Toner manufacturing method] The toner may be obtained by any known method such as a melt-kneading method, an emulsion phase inversion method, a polymerization method, or an emulsion aggregation method. From the viewpoint of productivity, however, a pulverized toner obtained by a melt-kneading method is preferred. In the case of a pulverized toner by a melt kneading method, for example, raw materials such as resin (A) and resin (B), and optionally a colorant, a release agent, and a charge control agent, are uniformly mixed in a mixer such as a Henschel mixer, and then melt-kneaded in an internal kneader, a single-screw or twin-screw extruder, an open roll kneader, or the like, followed by cooling, pulverization, and classification to produce the toner. The toner production method preferably includes a step of melt-kneading a mixture containing resin (A), resin (B), a colorant, etc. at a temperature in the range of 80° C. or more and 200° C. or less. The melt-kneading temperature is preferably 80° C. or more, more preferably 90° C. or more, and preferably 200° C. or less, more preferably 180° C. or less. The toner production method preferably includes a step of pulverizing and classifying the mixture obtained by melt kneading to obtain toner particles. The pulverization and classification can be performed by a known method.

[0101] The volume median particle size of toner particles (D 50 From the viewpoint of low-temperature fixability, the thickness is preferably 2 μm or more, more preferably 3 μm or more, and even more preferably 4 μm or more, and from the viewpoint of hot offset resistance, the thickness is preferably 10 μm or less, more preferably 8 μm or less, and even more preferably 7.5 μm or less.

[0102] The toner is preferably treated by adding a fluidizing agent or the like as an external additive to the surface of the toner particles. Examples of the external additive include inorganic material particles such as hydrophobic silica, titanium oxide particles, alumina particles, cerium oxide particles, and carbon black, and polymer particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Among these, hydrophobic silica is preferred. When an external additive is used, the amount of the external additive added 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 is preferably 5 parts by mass or less, more preferably 4.5 parts by mass or less, and even more preferably 4 parts by mass or less, relative to 100 parts by mass of the toner particles.

[0103] Toners are used, for example, to develop latent images formed in electrophotography, electrostatic recording, electrostatic printing, etc. Toners can be used as one-component developers, or mixed with a carrier to form two-component developers. EXAMPLES

[0104] The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. Physical properties of resins and the like were measured by the following methods. In the notation "alkylene oxide (X)" and the like, the number X in parentheses means the average number of moles of alkylene oxide added.

[0105] [Measurement method] [Softening point of resin] Using a flow tester "CFT-500D" (Shimadzu Corporation), 1 g of sample was heated at a temperature increase rate of 6°C / min, while applying a load of 1.96 MPa with the plunger, and extruding the sample from a nozzle with a diameter of 1 mm and a length of 1 mm. The plunger descent amount of the flow tester was plotted against the temperature, and the temperature at which half of the sample flowed out was taken as the softening point.

[0106] [Maximum endothermic peak temperature of resin] Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of sample was weighed into an aluminum pan, 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 were performed at a rate of 10°C / min. The temperature of the peak with the largest peak area among the observed endothermic peaks was taken as the maximum endothermic peak temperature. Note that for crystalline polyester resins, the maximum endothermic peak temperature is the melting point.

[0107] [Glass transition temperature of resin] Using a differential scanning calorimeter "Q-20" (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of sample was weighed into an aluminum pan, heated to 200°C, and cooled to 0°C at a rate of 10°C / min. The sample was then heated at a rate of 10°C / min, and the endothermic peak was measured. The glass transition temperature was determined as the temperature at the intersection of the extension of the baseline below the maximum endothermic peak temperature and the tangent line showing the maximum slope from the rising part of the peak to the top of the peak.

[0108] [Acid value of resin] The acid value of the resin was measured according to the method of JIS K 0070: 1992. However, only the measurement solvent was changed from the mixed solvent of ethanol and ether specified in JIS K 0070: 1992 to a mixed solvent of acetone and toluene [acetone:toluene = 1:1 (volume ratio)] for amorphous resins, and to a mixed solvent of chloroform and dimethylformamide [chloroform:dimethylformamide = 1:1 (volume ratio)] for crystalline resins.

[0109] [Melting point of release agent] Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of sample was weighed into an aluminum pan, heated to 200°C at a heating rate of 10°C / min, and cooled to -10°C at a heating rate of 5°C / min. The sample was then heated to 180°C at a heating rate of 10°C / min and measured, and the maximum endothermic peak temperature was taken as the melting point.

[0110] [Average particle size of external additives] The average particle size of the external additive refers to the number-average particle size, and was calculated by measuring the particle sizes (average values ​​of major and minor axes) of 500 particles from a scanning electron microscope (SEM) photograph and averaging these by the number.

[0111] [Volume median particle size of toner particles (D 50 )〕 Measuring instrument: Coulter Multisizer III (manufactured by Beckman Coulter, Inc.) Aperture diameter: 100μm Analysis software: Coulter Multisizer AccuComp version 1.19 (Beckman Coulter, Inc.) Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) Dispersion liquid: Polyoxyethylene lauryl ether "EMULGEN (registered trademark) 109P" (manufactured by Kao Corporation, HLB (Griffin) = 13.6) was dissolved in the electrolyte to adjust the concentration to 5 mass %. Dispersion conditions: 10 mg of the measurement sample was added to 5 mL of the dispersion liquid, and dispersed for 1 minute using an ultrasonic disperser (machine name "US-1": manufactured by SND Co., Ltd., output: 80 W). Then, 25 mL of electrolyte was added, and the mixture was further dispersed for 1 minute using the ultrasonic disperser to prepare a sample dispersion liquid. Measurement conditions: The sample dispersion was added to 100 mL of the electrolyte to adjust the concentration so that the particle size of 30,000 particles could be measured in 20 seconds. Then, 30,000 particles were measured, and the volume median particle size (D 50 ) was sought.

[0112] [Toner Evaluation] [Hot offset resistance] Toner was filled into a printer "B432dnw" (manufactured by Oki Electric Industry Co., Ltd.) that had been modified to be able to take unfixed images, and an unfixed image (image on the printing medium before being transferred and passing through the fixing roll) of a 2 cm square solid image was printed on a printing medium "J paper A4 size, high-quality paper" (manufactured by Fujifilm Business Innovation Co., Ltd.) Using an external fixing device modified from "B432dnw" (manufactured by Oki Electric Industry Co., Ltd.), the rotation speed of the fixing roll was adjusted at a speed equivalent to an 18-sheet machine, and the temperature of the fixing roll was raised from 100°C to 225°C in increments of 5°C, and the unfixed image was fixed at each temperature to obtain a fixed image. The printed unfixed image was passed through an external fixing device, and the images obtained at each fixing temperature were visually observed. If the toner adhered to the fixing roll and toner adhered to areas on the print medium where no unfixed image was formed, it was determined that hot offset had occurred. The temperature 5°C lower than the lowest fixing temperature at which hot offset occurred was used as an index of hot offset resistance. The higher the value, the better the hot offset resistance.

[0113] [Low temperature fixability after high temperature storage] 40 g of toner was placed in a 220 mL container and left in a high temperature (60° C.) environment for 48 hours. After that, a fixed image was obtained in the same manner as in [Hot offset resistance] above. However, the rotation speed of the fixing roll was adjusted to a speed equivalent to a 40-sheet machine. The images obtained at each fixing temperature were rubbed five times with a sand eraser "ER-502R" (manufactured by Lion Office Equipment Co., Ltd.) with a load of 400g, and the image density before and after rubbing was measured using a reflection densitometer "exact" (manufactured by X-Rite Co., Ltd.). The temperature at which the image density ratio before and after rubbing ([image density after rubbing / image density before rubbing] x 100) first exceeded 90% was taken as the minimum fixing temperature, which was used as an index of low-temperature fixing ability. The smaller the value, the better the low-temperature fixing ability.

[0114] [Resin manufacturing] [Production of crystalline polyester resin (A)] Production Example A1 (Crystalline Polyester Resin A1) The alcohol component (A-al), carboxylic acid component (A-ac) and esterification catalyst shown in Table 1 were placed in a 10-liter four-neck flask equipped with a dehydration tube equipped with a nitrogen inlet tube, a stirrer and a thermocouple, and the temperature was raised to 200°C over 8 hours in a mantle heater under a nitrogen atmosphere. Thereafter, the reaction was continued at 8.0 kPa until the softening point reached the temperature shown in Table 1, to obtain crystalline polyester resin A1. The physical properties are shown in Table 1.

[0115] Comparative Preparation Examples A1 and A2 (Crystalline Polyester Resins A11 and A12) Crystalline polyester resins A11 and A12 were obtained in the same manner as in Production Example A1, except that the alcohol component (A-al) and the carboxylic acid component (A-ac) and their amounts were changed as shown in Table 1. The physical properties are shown in Table 1.

[0116] [Table 1]

[0117] [Production of amorphous polyester resin (B)] Manufacturing Example B1 (Amorphous Polyester Resin B1) The alcohol component (B-al) and the carboxylic acid component (B-ac) other than trimellitic anhydride shown in Table 2, the esterification catalyst, and the modified silicone were placed in a 10-liter four-neck flask equipped with a dehydration tube equipped with a nitrogen inlet tube, a stirrer, and a thermocouple, and the temperature was raised to 235°C in a mantle heater under a nitrogen atmosphere and maintained for 6 hours. Thereafter, the pressure in the flask was reduced, and the mixture was reacted at 8 kPa for 1 hour, then the temperature was lowered to 220°C, and trimellitic anhydride was added, followed by reaction until the softening point reached the temperature shown in Table 2, to obtain amorphous polyester B1. The physical properties are shown in Table 2.

[0118] Production Examples B2 to B6 and Comparative Production Example B1 (Amorphous Polyester Resins B2 to B6 and B11) Amorphous polyester resins B2 to B6 and B11 were obtained in the same manner as in Production Example B1, except that the amount or type of modified silicone was changed as shown in Table 2. Table 2 shows the physical properties.

[0119] Comparative Production Example B2 (Amorphous Polyester Resin B12) Amorphous polyester resin B12 was obtained in the same manner as in Production Example B1, except that no modified silicone was used. The physical properties are shown in Table 2.

[0120] [Table 2]

[0121] The modified silicones used in Production Examples B1 to B6 and Comparative Production Example 1 are as follows. KF-8012: Modified silicone oil "KF-8012" (in formulas (1) and (2), R is a methyl group and the silicone has amino groups at both ends, kinematic viscosity (25°C) = 90 mm 2 / s, functional group equivalent weight = 2,200g / mol, Shin-Etsu Chemical Co., Ltd.) KF-6001: Modified silicone "KF-6001" (in formulas (1) and (2), R is a methyl group and the silicone has hydroxyl groups at both ends, kinematic viscosity (25°C) = 110 mm 2 / s, functional group equivalent = 903g / mol, Shin-Etsu Chemical Co., Ltd.) X-22-162C: Modified silicone oil "X-22-162C" (in the formulas (1) and (2), R is a methyl group and the silicone has carboxy groups at both ends, kinematic viscosity (25°C) 220 mm 2 / s, functional group equivalent 2,300g / mol, Shin-Etsu Chemical Co., Ltd.) X-22-170BX: Modified silicone "X-22-170BX" (in the formulas (1) and (2), R is a methyl group and the silicone has a carbinol group at one end, kinematic viscosity (25°C) = 40 mm 2 / s, functional group equivalent weight = 2800g / mol, Shin-Etsu Chemical Co., Ltd.)

[0122] [Production of composite resin (C1)] Production example C1 (composite resin C1) The raw material monomers and esterification catalyst of the polyester resin segment except trimellitic anhydride shown in Table 3 were placed in a 10-liter four-neck flask equipped with a dehydration tube equipped with a nitrogen inlet tube, a stirrer, and a thermocouple, and heated to 160 ° C in a mantle heater under a nitrogen atmosphere. Then, a mixture of the raw material monomers and polymerization initiator of the bireactive monomers and addition polymerization resin segment shown in Table 3 was dropped over 1 hour to perform a polymerization reaction. Then, the temperature was raised to 200 ° C and the reaction was allowed to mature for 1 hour to generate an addition polymerization resin in the reaction system. Then, the temperature was raised to 230 ° C over 1 hour, the pressure was reduced to 8.0 kPa, and dehydration condensation was allowed to occur for 1 hour, after which trimellitic anhydride was added, and the dehydration condensation reaction was continued at 230 ° C. until the softening point reached the temperature shown in Table 3, to obtain a composite resin C1. The physical properties are shown in Table 3.

[0123] [Table 3]

[0124] [Toner manufacturing] Example 1 (Toner 1) 100 parts by mass of binder resin consisting of resin (A), resin (B), and resin (C) in the amounts shown in Table 4, 0.2 parts by mass of colorant "Cyanine Blue 4927" (manufactured by Dainichiseika Chemical Industry Co., Ltd.), 4 parts by mass of colorant "Mogul-L" (manufactured by Cabot Corporation), 1 part by mass of charge control agent "T-77" (manufactured by Hodogaya Chemical Industry Co., Ltd.), and 1 part by mass of release agent "Carnauba Wax C1" (manufactured by Kato Yoko Co., Ltd., melting point: 83 ° C.) were thoroughly stirred with a Henschel mixer, and then a co-rotating twin screw extruder "PCM-30" (manufactured by Ikegai Co., Ltd.) was used. The operating conditions of the co-rotating twin screw extruder were barrel setting temperature 100 ° C, shaft rotation speed 200 r / min (circumferential speed of shaft rotation 0.30 m / sec), and mixture supply rate 10 kg / h. The resulting molten mixture was cooled and sized to have a volume median particle size (D 50 The particles were pulverized and classified so that the particle size became 7.0 μm, thereby obtaining toner particles.

[0125] To 100 parts by mass of the obtained toner particles, 1 part by mass of "Aerosil R-972" (hydrophobic silica, manufactured by Nippon Aerosil Co., Ltd., hydrophobic treatment agent: DMDS, average particle size: 16 nm) and 2 parts by mass of "RY-50" (hydrophobic silica, manufactured by Nippon Aerosil Co., Ltd., hydrophobic treatment agent: silicone oil, average particle size: 40 nm) were added as external additives, and the mixture was mixed in a Henschel mixer at 2300 r / min for 3 minutes to perform external additive treatment, thereby obtaining Toner 1. The hot offset resistance and low-temperature fixability after high-temperature storage were evaluated using the method described in [Toner Evaluation] above. The evaluation results are shown in Table 4.

[0126] Examples 2 to 8 and Comparative Examples 1 to 4 (Toners 2 to 12) Toners 2 to 12 of Examples 2 to 8 and Comparative Examples 1 to 4 were obtained in the same manner as in Example 1, except that resin (A), resin (B), and resin (C) were changed to the resins and amounts shown in Table 4. The evaluation results of hot offset resistance and low-temperature fixing temperature after high-temperature storage are shown in Table 4.

[0127] [Table 4]

[0128] As shown in Table 4, from the results of the Examples and Comparative Examples, the toners 1 to 8 of the present invention exhibited excellent hot offset resistance and low-temperature fixability after high-temperature storage. On the other hand, toner 9 of Comparative Example 1, which contains resin B11 using modified silicone having a reactive group at one end as the modified silicone instead of resin (B), is excellent in hot offset resistance, but requires a high temperature for fixing the toner after high-temperature storage. Also, toner 10 of Comparative Example 2, which uses amorphous polyester resin B12, which is not a silicone modified resin, instead of resin (B), is excellent in low-temperature fixing property after high-temperature storage, but no improvement in hot offset resistance was observed. Furthermore, toner 11 of Comparative Example 3, which contains resin A11 in which 1,4-butanediol is used instead of ethylene glycol as the alcohol component (A-al) instead of resin (A), and toner 12 of Comparative Example 4, which contains resin A12 in which 1,6-hexanediol is used instead of ethylene glycol, were excellent in hot offset resistance, but required a high temperature to fix the toner after high-temperature storage.

Claims

1. A toner containing a crystalline polyester resin (A) and an amorphous polyester resin (B) as binder resins, the crystalline polyester resin (A) is a polycondensate of raw material monomers (a) containing an alcohol component (A-al) containing ethylene glycol and a carboxylic acid component (A-ac) containing an aliphatic carboxylic acid; the amorphous polyester resin (B) is a silicone-modified polyester resin that is a reaction product of a raw material monomer (b) that contains an alcohol component (B-al) containing a divalent or higher alcohol, a carboxylic acid component (B-ac) containing a divalent or higher carboxylic acid, and a both-end-modified silicone.

2. 2. The toner according to claim 1, wherein the alcohol component (A-al) contains 80 mol % or more of ethylene glycol.

3. 2. The toner according to claim 1, wherein the carboxylic acid component (A-ac) contains an aliphatic monocarboxylic acid in an amount of 2 mol % or more and 20 mol % or less.

4. 2. The toner according to claim 1, wherein the both-end-modified silicone has a repeating unit represented by formula (1) and a structure represented by formula (2). 【Chemical 1】 In formula (1), each R is independently a hydrocarbon group having 1 to 6 carbon atoms, and * represents a bonding site. *-SiR ３－ａ (R’-X) ａ (2) [In formula (2), each R is independently a hydrocarbon group having from 1 to 6 carbon atoms, each R' is independently an alkylene group having from 1 to 10 carbon atoms, a is an integer of from 1 to 3, each X is independently a group containing an amino group, a carboxy group, an epoxy group, or a hydroxy group, and * is a bonding site.]

5. 2. The toner according to claim 1, wherein the amount of the both-end-modified silicone charged in the raw material monomer (b) is 1 part by mass or more and 20 parts by mass or less per 100 parts by mass of the total of the alcohol component (B-al) and the carboxylic acid component (B-ac).

6. 6. The toner according to claim 1, further comprising a non-silicone-modified amorphous polyester resin (C).

7. The toner according to claim 6, wherein the amorphous polyester resin (C) is a composite resin (C1).

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