Toner binder resin composition

Abstract

The present invention relates to a binder resin composition for toner that exhibits excellent low-temperature fixing properties and resistance to hot offset, and has a wide fixing width, and toner for electrostatic image development containing the binder resin composition. [Solution] A binder resin composition for toner containing an amorphous polyester composite resin AC in which a polyester resin segment and an addition polymerization resin segment are bonded together via covalent bonds, wherein the content of methyl ethyl ketone insoluble material not derived from the addition polymerization resin segment is 10% by mass or more and 20% by mass or less in the amorphous polyester composite resin AC, and the softening point of the amorphous polyester composite resin AC is 100°C or more and 115°C or less, and a toner for electrostatic image developing containing the binder resin composition.

Description

[Technical Field]

[0001] The present invention relates to a binder resin composition for toner used in developing latent images formed in electrophotography, electrostatic recording, electrostatic printing, and the like, and toner for developing electrostatic images containing the binder resin composition. [Background technology]

[0002] In recent years, in the field of electrophotography, the development of electrostatic image developing toners that support high image quality and high-speed printing has been required as electrophotographic systems have advanced. To meet these demands, composite resins in which a polyester resin segment with excellent low-temperature fixability is covalently bonded to an addition polymerization resin segment have been investigated (see Patent Documents 1 and 2). [Prior art documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Publication No. 2021-107920 [Patent Document 2] Japanese Patent Publication No. 2021-107894 [Overview of the project] [Problems that the invention aims to solve]

[0004] To improve low-temperature adhesion, increasing the proportion of resins with low softening points is effective. On the other hand, hot offset resistance is greatly influenced by the molecular weight of the resin, and since molecular weight is generally proportional to the softening point, increasing the proportion of resins with high softening points is effective in improving hot offset resistance. Therefore, low-temperature adhesion and hot offset resistance are in a trade-off relationship, and achieving both is a challenge.

[0005] The present invention relates to a binder resin composition for toner that has excellent low-temperature fixing properties and hot offset resistance and a wide fixing width, and toner for electrostatic image development containing the binder resin composition. [Means for solving the problem]

[0006] The present invention [1] A binder resin composition for toner containing an amorphous polyester composite resin AC in which a polyester resin segment and an addition polymerization resin segment are bonded together via covalent bonds, wherein the content of methyl ethyl ketone insoluble material not derived from the addition polymerization resin segment is 10% by mass or more and 20% by mass or less in the amorphous polyester composite resin AC, and the softening point of the amorphous polyester composite resin AC is 100°C or more and 115°C or less, and [2] A toner for developing electrostatic images containing the toner binder resin composition described in [1] above. Regarding. [Effects of the Invention]

[0007] The toner binder resin composition of the present invention exhibits excellent effects in low-temperature fixing properties, hot offset resistance, and expansion of the fixing width. [Modes for carrying out the invention]

[0008] The toner binder resin composition of the present invention (hereinafter also referred to as the binder resin composition) is a toner binder resin composition containing an amorphous polyester composite resin AC in which a polyester resin segment and an addition polymerization resin segment are bonded together via covalent bonds, and is characterized in that the amorphous polyester composite resin AC, which has a low softening point, contains a predetermined amount of methyl ethyl ketone (MEK) insoluble material that does not originate from the addition polymerization resin segment. The reason why the effects of the present invention are achieved is not clear, but it is presumed to be as follows. Note that the following mechanism is a presumption and is not limited thereto.

[0009] To obtain a toner that satisfies both low-temperature fixing and hot-offset resistance, a resin containing high molecular weight components is required while maintaining a low softening point. Generally, one way to increase the molecular weight of a resin is to crosslink it using a low-molecular-weight polyfunctional monomer as a crosslinking agent. However, because the molecular weight of the crosslinking agent is small, the crosslinking reaction proceeds throughout the entire resin, increasing both the molecular weight and the softening point. Since both the molecular weight and the softening point of the resin rise, it is not possible to achieve both low-temperature fixing and hot-offset resistance at the same time. In contrast, by using a crosslinking agent with a large molecular weight, the crosslinking reaction acts locally, making it possible to obtain a resin that contains some high molecular weight components due to the crosslinking reaction, even though the majority of the resin remains uncrosslinked. This resin has a low softening point, resulting in excellent low-temperature fixation, and further improvements in hot offset resistance due to the high molecular weight components can also be expected. Therefore, as a result of the inventors' investigation, they found that addition polymerization resins act as polymer crosslinking agents for amorphous polyester resins. In amorphous polyester composite resins in which polyester resin segments and addition polymerization resin segments are bonded together via covalent bonds, the high molecular weight component effective in improving hot offset resistance is a polymer composite obtained by a crosslinking reaction between the addition polymerization resin, which acts as a polymer crosslinking agent, and the amorphous polyester resin. Therefore, in the present invention, by adjusting the content of MEK-insoluble components not derived from the addition polymerization resin segment to a predetermined range, a composite resin that achieves both low-temperature fixability and hot-offset resistance while maintaining a low softening point can be obtained. Furthermore, as a result of achieving both low-temperature fixability and hot-offset resistance, an effect of expanding the fixation width was observed.

[0010] The crystalline or amorphous nature of a resin is determined by its crystallinity index. The crystallinity index is defined as the ratio of the resin's softening point to its 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 in which the crystallinity index is between 0.6 and 1.4. An amorphous resin is one in which no endothermic peak is observed, or if observed, the crystallinity index is less than 0.6 or greater than 1.4. The crystallinity of the resin can be adjusted by the type and ratio of raw material monomers, and manufacturing conditions (e.g., reaction temperature, reaction time, cooling rate), etc. The maximum peak temperature of endotherm refers to the temperature of the peak with the largest peak area among the observed endothermic peaks. In the case of a crystalline resin, the maximum peak temperature of endotherm is taken as the melting point.

[0011] The amorphous polyester-based composite resin AC is a composite resin in which a polyester-based resin segment and an addition polymerization-based resin segment are bonded via a covalent bond, and is a resin in which the content of methyl ethyl ketone-insoluble matter and the softening point not derived from the addition polymerization-based resin segment are adjusted to the following ranges.

[0012] The content of methyl ethyl ketone-insoluble matter not derived from the addition polymerization-based resin segment is 10% by mass or more, preferably 11% by mass or more, more preferably 14% by mass or more, still more preferably 15% by mass or more, and 20% by mass or less, preferably 18% by mass or less, more preferably 17% by mass or less, still more preferably 16.5% by mass or less in the amorphous polyester-based composite resin AC. The high molecular weight components in the resin can be detected as methyl ethyl ketone (MEK)-insoluble matter. However, in the case of a composite resin, since the addition polymerization-based resin segment is also detected as MEK-insoluble matter, the two cannot be distinguished as MEK-insoluble matter. Therefore, in order to actually obtain the amount of high molecular weight components effective for hot offset resistance, it is necessary to subtract the MEK-insoluble matter derived from the addition polymerization-based resin segment from the total amount of MEK-insoluble matter. Therefore, the methyl ethyl ketone-insoluble matter not derived from the addition polymerization-based resin segment is the value obtained by subtracting the methyl ethyl ketone-insoluble matter derived from the addition polymerization-based resin segment from the methyl ethyl ketone-insoluble matter in the composite resin.

[0013] The softening point of the amorphous polyester-based composite resin AC is 100°C or higher, preferably 103°C or higher, more preferably 108°C or higher from the viewpoint of hot offset resistance, and 115°C or lower, preferably 112°C or lower from the viewpoint of low temperature fixing property.

[0014] The polyester resin segment is formed by polycondensation of an alcohol component and a carboxylic acid component, which are raw material monomers of the polyester resin.

[0015] From the viewpoint of low-temperature fixing property, the alcohol component is of the formula (I):

[0016] [Chemical formula]

[0017] (In the formula, OR and RO are oxyalkylene groups, R is an ethylene group and / or a propylene group, x and y represent the average number of moles of alkylene oxide added, and are each a positive number. The value of the sum of x and y is 1 or more, preferably 1.5 or more, and 16 or less, preferably 8 or less, more preferably 6 or less, still more preferably 4 or less, and still more preferably 2.5 or less) It is preferably contained an alkylene oxide adduct of bisphenol A represented by the formula (I). Examples of the alkylene oxide adduct of bisphenol A represented by the formula (I) include a polyoxypropylene adduct of 2,2-bis(4-hydroxyphenyl)propane, a polyoxyethylene adduct of 2,2-bis(4-hydroxyphenyl)propane, and the like. It is preferable to use one or more of these.

[0018] The content of the alkylene oxide adduct of bisphenol A represented by the formula (I) is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, still more preferably 95 mol% or more, and 100 mol% or less in the alcohol component.

[0019] Other alcohol components include aliphatic diols such as ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, neopentyl glycol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol, as well as trivalent or higher alcohols such as bisphenol A, hydrogenated bisphenol A, sorbitol, pentaerythritol, glycerin, and trimethylolpropane.

[0020] From the viewpoint of low-temperature fixability, the carboxylic acid component preferably contains an aromatic dicarboxylic acid compound.

[0021] Examples of aromatic dicarboxylic acid compounds include phthalic acid, isophthalic acid, terephthalic acid, anhydrides of these acids, and alkyl esters with one to three carbon atoms in the alkyl group. Among these, terephthalic acid is preferred from the viewpoint of low-temperature fixability.

[0022] The content of aromatic dicarboxylic acid compounds is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and even more preferably 95 mol% or more, and 100 mol% or less, in the carboxylic acid component.

[0023] Other carboxylic acid components include oxalic acid, malonic acid, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, aliphatic dicarboxylic acids such as succinic acid, adipic acid, and sebacic acid which may be substituted with hydrocarbon groups having 1 to 20 carbon atoms, trivalent or higher carboxylic acids such as 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalentricarboxylic acid, and pyromellitic acid, anhydrides of these acids, and alkyl esters of alkyl groups having 1 to 3 carbon atoms.

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

[0025] In this specification, macromonomers and hydroxycarboxylic acids are not included in the alcohol and carboxylic acid components.

[0026] The equivalent ratio (COOH group / OH group) of the carboxyl group of the carboxylic acid component to the hydroxyl group of the alcohol component is preferably 0.6 or higher, more preferably 0.7 or higher, even more preferably 0.8 or higher, and preferably 1.3 or lower, more preferably 1.2 or lower, from the viewpoint of adjusting the softening point of the polyester resin.

[0027] Polyester resin segments can be produced, for example, by polycondensing an alcohol component and a carboxylic acid component in an inert gas atmosphere, and optionally in the presence of an esterification catalyst, co-catalyst, polymerization inhibitor, etc., at a temperature preferably 160°C or higher, more preferably 200°C or higher, and preferably 250°C or lower, more preferably 240°C or lower.

[0028] Examples of esterification catalysts include tin compounds such as dibutyltin oxide and tin(II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropoxybis(triethanolamine) and titanium dihydroxybis(triethanolamine). The amount of esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 1.5 parts by mass or less, and more preferably 1 part by mass or less, per 100 parts by mass of the total amount of alcohol and carboxylic acid components. Examples of co-catalysts for the esterification catalyst include gallic acid. The amount of co-catalyst used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.5 parts by mass or less, and more preferably 0.1 parts by mass or less, per 100 parts by mass of the total amount of alcohol and carboxylic acid components. Examples of polymerization inhibitors include tert-butylcatechol. The amount of polymerization inhibitor used is preferably 0.001 parts by mass or more, more preferably 0.01 parts by mass or more, and preferably 0.5 parts by mass or less, and more preferably 0.1 parts by mass or less, based on 100 parts by mass of the total amount of alcohol and carboxylic acid components.

[0029] The content of polyester resin segments in amorphous polyester composite resin AC is preferably 80% by mass or more, more preferably 85% by mass or more, and even more preferably 88% by mass or more, from the viewpoint of low-temperature fixability, and preferably 95% by mass or less, more preferably 93% by mass or less, and even more preferably 90% by mass or less, from the viewpoint of hot offset resistance.

[0030] It is preferable to use a pre-fabricated addition polymerization resin for the addition polymerization resin segment.

[0031] The raw material monomers for addition polymerization resins preferably contain (meth)acrylic acid from the viewpoint of reactivity with polyester resin segments. In this specification, "(meth)acrylic acid" refers to acrylic acid, methacrylic acid, or both.

[0032] The (meth)acrylic acid content is preferably 15% by mass or more, more preferably 20% by mass or more, even more preferably 25% by mass or more, and preferably 45% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less, in the raw material monomer of the addition polymerization resin.

[0033] Examples of raw material monomers for addition polymerization resins other than (meth)acrylic acid include styrene compounds, alkyl (meth)acrylates, ethylenically unsaturated monoolefins such as ethylene and propylene; diolefins such as butadiene; halovinyls such as vinyl chloride; vinyl esters such as vinyl acetate and vinyl propionate; ethylenically monocarboxylic acid esters such as dimethylaminoethyl (meth)acrylate; vinyl ethers such as methyl vinyl ether; vinylidene halides such as vinylidene chloride; and N-vinyl compounds such as N-vinylpyrrolidone. Among these, styrene compounds or alkyl (meth)acrylates are preferred.

[0034] Examples of styrene-based compounds include styrene, α-methylstyrene, vinyltoluene, and other styrene derivatives, with styrene being preferred.

[0035] The content of styrene compounds in the raw material monomers of the addition polymerization resin is preferably 55% by mass or more, more preferably 60% by mass or more, even more preferably 65% ​​by mass or more, and preferably 85% by mass or less, more preferably 80% by mass or less, and even more preferably 75% by mass or less.

[0036] Examples of alkyl (meth)acrylates include methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, (iso)octyl (meth)acrylate, (iso)decyl (meth)acrylate, and (iso)stearyl (meth)acrylate. Among these, at least one selected from the group consisting of methyl (meth)acrylate and 2-ethylhexyl (meth)acrylate is preferred. In this specification, "(iso)" means that this group may or may not be present, and when this group is not present, it indicates that the product is normal.

[0037] Addition polymerization resins are preferably produced by bulk polymerization, solution polymerization, suspension polymerization, or emulsion polymerization, and from the viewpoint of production stability, production by solution polymerization is more preferable.

[0038] In this invention, "solution polymerization" refers to a method of polymerization in which raw material monomers are heated in an organic solvent together with a polymerization initiator and a chain transfer agent.

[0039] Examples of polymerization initiators include peroxides such as di-tert-butyl peroxide, persulfates such as sodium persulfate, and azo compounds such as 2,2'-azobis(2,4-dimethylvaleronitrile) and 4,4'-azobis(4-cyanovaleric acid).

[0040] Examples of chain transfer agents include cationic chain transfer agents such as 1-amino-2-methyl-2-propanethol, and anionic chain transfer agents such as 3-mercaptopropionic acid.

[0041] In solution polymerization, the amount of polymerization initiator and chain transfer agent used is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, and preferably 10 parts by mass or less, more preferably 7 parts by mass or less, and even more preferably 5 parts by mass or less, per 100 parts by mass of raw material monomer of the addition polymerization resin.

[0042] Examples of organic solvents used in solution polymerization include xylene, toluene, methyl ethyl ketone, and acetone. The amount of organic solvent used is preferably 50 parts by mass to 150 parts by mass per 100 parts by mass of raw material monomers for the addition polymerization resin segment.

[0043] The temperature conditions for solution polymerization are preferably 60°C or higher, more preferably 70°C or higher, and preferably 100°C or lower, more preferably 90°C or lower.

[0044] "Bulk polymerization" is a method of addition polymerization carried out under conditions where substantially no solvent is present in the reaction system, i.e., under solvent-free conditions. It is preferably carried out at high temperature under pressure above atmospheric pressure, and more preferably as continuous bulk polymerization under high temperature and high pressure. In the present invention, a pressurized state refers to a state in which the contents are heated above the boiling point at atmospheric pressure in a sealed container such as an autoclave. Under high temperature under pressure above atmospheric pressure, radicals generated by the thermal initiation reaction of the raw material monomers function as polymerization initiators, allowing addition polymerization to proceed even under conditions with relatively few radical generators, and enabling the production of an addition polymerization resin with a narrow molecular weight distribution.

[0045] Furthermore, in the case of continuous bulk polymerization under high temperature and high pressure, it is possible to control not only the molecular weight distribution but also the monomer composition distribution, thereby obtaining a more uniform addition polymerization resin with a narrow monomer composition distribution.

[0046] From the above viewpoint, the temperature for bulk polymerization is preferably 140°C or higher, more preferably 180°C or higher, even more preferably 220°C or higher, even more preferably 260°C or higher, even more preferably 280°C or higher, and preferably 350°C or lower, more preferably 320°C or lower.

[0047] The acid value of the addition polymerization resin segment is preferably 140 mg KOH / g or more, more preferably 180 mg KOH / g or more, and even more preferably 220 mg KOH / g or more, from the viewpoint of reactivity with the polyester resin segment and resistance to hot offset, and from the viewpoint of low-temperature fixation, it is preferably 280 mg KOH / g or less, more preferably 270 mg KOH / g or less, and even more preferably 260 mg KOH / g or less.

[0048] The weight-average molecular weight of the addition polymerization resin segment is preferably 10,000 or more, more preferably 12,000 or more, and even more preferably 15,000 or more, from the viewpoint of resistance to hot offset, and preferably 22,000 or less, more preferably 20,000 or less, and even more preferably 18,000 or less, from the viewpoint of low-temperature fixation.

[0049] In this invention, the acid value and weight-average molecular weight of the addition polymerization resin segment are the acid value and weight-average molecular weight of the addition polymerization resin used in the production of the composite resin.

[0050] The content of the addition polymerization resin segment in the amorphous polyester composite resin AC is preferably 5% by mass or more, more preferably 7% by mass or more, and even more preferably 10% by mass or more, from the viewpoint of hot offset resistance, and preferably 20% by mass or less, more preferably 15% by mass or less, and even more preferably 12% by mass or less, from the viewpoint of low-temperature fixation.

[0051] The composite resin is preferably a resin in which a polyester resin segment and an addition polymerization resin segment are covalently bonded together by reactive monomers that can react with both the raw material monomers of the polyester resin and the raw material monomers of the addition polymerization resin.

[0052] The two reactive monomers are preferably compounds having at least one functional group selected from the group consisting of hydroxyl groups, carboxyl groups, epoxy groups, primary amino groups, and secondary amino groups, preferably a hydroxyl group and / or a carboxyl group, more preferably a carboxyl group, and an ethylenically unsaturated bond within the molecule. More preferably, at least one selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic acid, and maleic anhydride is preferred, and even more preferably, at least one selected from the group consisting of acrylic acid, methacrylic acid, and fumaric acid is preferred from the viewpoint of reactivity in polycondensation and addition polymerization reactions. However, when used together with a polymerization inhibitor, polycarboxylic acid compounds having an ethylenically unsaturated bond, such as fumaric acid, function as raw material monomers for polyester resins. In this case, fumaric acid, etc., are not two reactive monomers, but raw material monomers for polyester resins.

[0053] In this invention, if (meth)acrylic acid is included as a raw material monomer for the addition polymerization resin, (meth)acrylic acid also acts as both reactive monomers.

[0054] Methods for producing amorphous polyester composite resin AC, which is a composite of polyester resin segments and addition polymerization resin segments, include (i) a method by polymer reaction between polyester resin and addition polymerization resin, (ii) a method in which the raw materials of polyester resin are reacted in the presence of addition polymerization resin, and (iii) a method in which a portion of the raw materials of polyester resin are reacted, and then the addition polymerization resin and the remaining raw materials of polyester resin are added and the reaction is carried out.

[0055] In method (i), it is preferable that the polymerization reactions of the polyester resin and the addition polymerization resin are carried out in independent reaction systems. If the polymerization reactions of the addition polymerization resin and the polyester resin are in independent reaction systems, the progress and completion of the two polymerization reactions do not need to be simultaneous in time; the reaction temperature and time can be appropriately selected according to the respective reaction mechanisms to allow the reactions to proceed and be completed. Furthermore, in the polymer reaction of method (i), there are no particular restrictions on the method of mixing the polyester resin and the addition polymerization resin. For example, one method is to isolate the polyester resin obtained by polycondensation of the raw material monomers (alcohol component and carboxylic acid component) of the polyester resin, and then mix the polyester resin with the addition polymerization resin. Another method is to obtain a polyester resin by polycondensation of the raw material monomers of the polyester resin, and then add and mix the obtained polyester resin with the addition polymerization resin without isolating it.

[0056] In method (iii), an example is a method in which the alcohol component is reacted with a portion of the carboxylic acid component, and then the addition polymerization resin and the remainder of the carboxylic acid component are added to carry out the reaction.

[0057] Among these methods, method (i) described above is preferred from the viewpoint of controlling molecular weight, molecular weight distribution, and copolymerizability of monomers, while maintaining excellent low-temperature fixability and broadening the fixation temperature range. In other words, amorphous polyester composite resin AC is preferably produced by a method including the following steps I and II. The addition polymerization reaction in step I and the polycondensation reaction in step II are as described above. Step I: A process to obtain an addition polymerization resin by addition polymerization of raw material monomers for an addition polymerization resin. Step II: After polycondensing the raw material monomers (alcohol component and carboxylic acid component) of the polyester resin, the addition polymerization resin obtained in Step I is added and the reaction is carried out to obtain the composite resin.

[0058] The acid value of the addition polymerization resin used for compounding is preferably 140 mg KOH / g or higher, more preferably 180 mg KOH / g or higher, and even more preferably 220 mg KOH / g or higher, from the viewpoint of reactivity with polyester resin segments and resistance to hot offset, and from the viewpoint of low-temperature fixation, it is preferably 280 mg KOH / g or lower, more preferably 270 mg KOH / g or lower, and even more preferably 260 mg KOH / g or lower.

[0059] The weight-average molecular weight of the addition polymerization resin is preferably 10,000 or more, more preferably 12,000 or more, and even more preferably 15,000 or more, from the viewpoint of resistance to hot offset, and preferably 22,000 or less, more preferably 20,000 or less, and even more preferably 18,000 or less, from the viewpoint of low-temperature fixation.

[0060] In amorphous polyester composite resin AC, the mass ratio of the addition polymerization resin segment to the polyester resin segment (addition polymerization resin segment / polyester resin segment) is preferably 5 / 95 or higher, more preferably 7 / 93 or higher, even more preferably 10 / 90 or higher, and preferably 20 / 80 or lower, more preferably 15 / 85 or lower, and even more preferably 12 / 88 or lower, from the viewpoint of improving the dispersibility of the raw materials in the toner. In the above calculation, the mass of the polyester resin segment is the amount obtained by subtracting the amount of reaction water (calculated value) dehydrated by the polycondensation reaction from the mass of the raw material monomers of the polyester resin used.

[0061] The glass transition temperature of amorphous polyester composite resin AC is preferably 50°C or higher, more preferably 55°C or higher, from the viewpoint of storage stability and durability, and preferably 70°C or lower, more preferably 65°C or lower, from the viewpoint of low-temperature fixation.

[0062] The acid value of the amorphous polyester composite resin AC is preferably 1 mg KOH / g or more, more preferably 2 mg KOH / g or more, from the viewpoint of low-temperature fixability, and preferably 10 mg KOH / g or less, more preferably 8 mg KOH / g or less, and even more preferably 6 mg KOH / g or less, from the viewpoint of hot offset resistance.

[0063] The content of amorphous polyester composite resin AC in the binder resin composition is preferably 5% by mass or more, more preferably 15% by mass or more, even more preferably 25% by mass or more, and preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 35% by mass or less.

[0064] From the viewpoint of low-temperature fixation properties, the toner binder resin composition of the present invention preferably further contains a crystalline polyester resin CP.

[0065] The crystalline polyester resin CP is preferably a polycondensate of an alcohol component and a carboxylic acid component, and more preferably a polycondensate of an alcohol component and a carboxylic acid component containing ethylene glycol, from the viewpoint of low-temperature fixability and storage properties.

[0066] The ethylene glycol content is preferably 70 mol% or more, more preferably 80 mol% or more, even more preferably 90 mol% or more, and even more preferably 95 mol% or more, and 100 mol% or less, in the alcohol component.

[0067] Other alcohol components include aliphatic diols other than ethylene glycol such as 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol, 1,8-octanediol, neopentyl glycol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, and 1,12-dodecanediol, alkylene oxide adducts of bisphenol A, aromatic diols such as bisphenol A, hydrogenated bisphenol A, sorbitol, pentaerythritol, glycerin, and trivalent or higher alcohols such as trimethylolpropane.

[0068] The carboxylic acid component preferably contains an aliphatic dicarboxylic acid compound.

[0069] Examples of aliphatic dicarboxylic acid compounds include sebacic acid (10 carbon atoms), dodecanediic acid (12 carbon atoms), tetradecanediic acid (14 carbon atoms), hexadecanedioic acid (16 carbon atoms), the anhydrides of these acids, and alkyl esters in which the alkyl group has 1 to 3 carbon atoms. Among these, tetradecanediic acid is preferred.

[0070] From the viewpoint of storage stability, the carbon number of the aliphatic dicarboxylic acid compound is preferably 10 or more, more preferably 12 or more, and from the viewpoint of low-temperature fixability, it is preferably 16 or less, more preferably 14 or less. Here, the carbon number of the alkyl group when the aliphatic dicarboxylic acid compound is an alkyl ester is not included in the above carbon number.

[0071] From the viewpoint of storage stability, the content of aliphatic dicarboxylic acid compounds is preferably 80 mol% or more, more preferably 85 mol% or more, even more preferably 90 mol% or more, and 100 mol% or less, and preferably 97 mol% or less, in the carboxylic acid component.

[0072] From the viewpoint of low-temperature fixability and durability, the carboxylic acid component of the crystalline polyester resin CP preferably further contains an aliphatic monocarboxylic acid compound.

[0073] Examples of aliphatic monocarboxylic acid compounds include capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, behenic acid, and alkyl esters of these acids in which the alkyl group has 1 to 3 carbon atoms.

[0074] The carbon number of the aliphatic monocarboxylic acid compound is preferably 16 or more, more preferably 18 or more, from the viewpoint of improving durability due to the high dispersion of the crystalline polyester resin CP, and preferably 24 or less, more preferably 22 or less, from the viewpoint of low-temperature fixation after long-term storage. Here, the carbon number of the alkyl group when the aliphatic monocarboxylic acid compound is an alkyl ester is not included in the above carbon number.

[0075] When the carboxylic acid component contains an aliphatic monocarboxylic acid compound, the content of the aliphatic monocarboxylic acid compound is preferably 2 mol% or more, more preferably 3 mol% or more, and preferably 15 mol% or less, and more preferably 10 mol% or less, in the carboxylic acid component.

[0076] 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.

[0077] The equivalent ratio of the carboxyl group of the carboxylic acid component to the hydroxyl group of the alcohol component (COOH group / OH group) is preferably 0.7 or higher, more preferably 0.8 or higher, from the viewpoint of electrostatic stability, and preferably 1.3 or lower, more preferably 1.2 or lower, from the viewpoint of low-temperature fixability.

[0078] The polycondensation reaction conditions between the alcohol component and the carboxylic acid component of the crystalline polyester resin CP are the same as those for the polyester resin segment of the amorphous polyester composite resin AC, except that the preferred reaction temperature is 120°C or higher, more preferably 180°C or higher, and 230°C or lower, more preferably 220°C or lower.

[0079] In this invention, the polyester resin may be a polyester resin that has been modified to such an extent that its properties are not substantially impaired. Examples of modified polyester resins include polyester resins that have been grafted or blocked with phenol, urethane, epoxy, etc., by methods described in Japanese Patent Publication No. 11-133668, Japanese Patent Publication No. 10-239903, Japanese Patent Publication No. 8-20636, etc.

[0080] The softening point of the crystalline polyester resin CP is preferably 50°C or higher, more preferably 65°C or higher, and even more preferably 70°C or higher, from the viewpoint of storage stability and durability, and preferably 120°C or lower, more preferably 110°C or lower, from the viewpoint of low-temperature fixation.

[0081] The melting point of the crystalline polyester resin CP is preferably 60°C or higher, more preferably 70°C or higher, from the viewpoint of storage stability and durability, and preferably 110°C or lower, more preferably 100°C or lower, from the viewpoint of low-temperature fixability.

[0082] The ratio of the softening point to the melting point (softening point / melting point) of the crystalline polyester resin CP is preferably 0.7 or higher, more preferably 0.9 or higher, and preferably 1.3 or lower, more preferably 1.2 or lower.

[0083] From the viewpoint of electrostatic stability, the acid value of the crystalline polyester resin CP is preferably 1 mg KOH / g or more, more preferably 3 mg KOH / g or more, and preferably 20 mg KOH / g or less, more preferably 15 mg KOH / g or less.

[0084] The content of crystalline polyester resin CP in the binder resin composition is preferably 3% by mass or more, more preferably 5% by mass or more, and even more preferably 8% by mass or more, from the viewpoint of low-temperature fixation, and preferably 30% by mass or less, more preferably 25% by mass or less, and even more preferably 20% by mass or less, from the viewpoint of electrostatic stability.

[0085] From the viewpoint of low-temperature fixation properties, the toner binder resin composition of the present invention preferably further contains an amorphous polyester resin AP.

[0086] The amorphous polyester resin AP is preferably a polycondensate of an alcohol component and a carboxylic acid component.

[0087] From the viewpoint of low-temperature fixation, the alcohol component preferably contains an alkylene oxide adduct of bisphenol A represented by formula (I). Examples of alkylene oxide adducts of bisphenol A represented by formula (I) include ethylene oxide adducts of bisphenol A and propylene oxide adducts of bisphenol A. It is preferable to use one or more of these.

[0088] The content of the bisphenol A alkylene oxide adduct represented by formula (I) is preferably 80 mol% or more, more preferably 90 mol% or more, even more preferably 95 mol% or more, and 100 mol% or less, in the alcohol component.

[0089] Other alcohol components include aliphatic diols and trivalent or higher alcohols.

[0090] 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, 1,3-butanediol, and neopentyl glycol.

[0091] Examples of alcohols with a hydride of 3 or higher include glycerin, trimethylolpropane, and pentaerythritol.

[0092] From the viewpoint of resistance to hot offsetting, the carboxylic acid component preferably includes an aromatic dicarboxylic acid compound.

[0093] Examples of aromatic dicarboxylic acid compounds include phthalic acid, isophthalic acid, terephthalic acid, anhydrides of these acids, and alkyl esters of these acids with 1 to 3 carbon atoms.

[0094] The content of aromatic dicarboxylic acid compounds is preferably 50 mol% or more, more preferably 70 mol% or more, even more preferably 80 mol% or more, even more preferably 90 mol% or more, and 100 mol% or less, of the carboxylic acid component. If the carboxylic acid component contains trivalent or higher carboxylic acid compounds, the content is preferably 90 mol% or less, and more preferably 85 mol% or less.

[0095] Other carboxylic acid components include fumaric acid, maleic acid, succinic acid, succinic acid derivatives substituted with hydrocarbon groups, aliphatic dicarboxylic acids such as glutaric acid, adipic acid, and sebacic acid, trivalent or higher carboxylic acids such as trimellitic acid and pyromellitic acid, anhydrides of these acids, and alkyl esters of these acids with 1 to 3 carbon atoms.

[0096] The alcohol component may appropriately contain a monohydric alcohol, and the carboxylic acid component may appropriately contain a monohydric carboxylic acid compound.

[0097] The polycondensation reaction conditions between the alcohol component and the carboxylic acid component of amorphous polyester resin AP are the same as those for the polyester resin segment of amorphous polyester composite resin AC.

[0098] The softening point of amorphous polyester resin AP is preferably 70°C or higher, more preferably 90°C or higher, even more preferably 100°C or higher, and preferably 170°C or lower, more preferably 160°C or lower, and even more preferably 150°C or lower, from the viewpoint of resistance to hot offset and gloss.

[0099] Furthermore, the amorphous polyester resin AP preferably contains two resins with different softening points, from the viewpoint of low-temperature fixability and fixation width. The difference in softening points between the two resins is preferably 10°C or more, more preferably 20°C or more, and preferably 60°C or less, more preferably 50°C or less.

[0100] The softening point of the resin with the higher softening point (resin AH) is preferably 100°C or higher, more preferably 110°C or higher, even more preferably 120°C or higher, and preferably 170°C or lower, more preferably 160°C or lower, and even more preferably 150°C or lower, from the viewpoint of resistance to hot offset and gloss.

[0101] The MEK-insoluble content of resin AH in amorphous polyester resin AP is preferably 15% by mass or more, more preferably 20% by mass or more, and preferably 35% by mass or less, more preferably 30% by mass or less, from the viewpoint of hot offset resistance.

[0102] Furthermore, the softening point of the resin with the lower softening point (resin AL) is preferably 70°C or higher, more preferably 90°C or higher, and more preferably 130°C or lower, more preferably 125°C or lower, and even more preferably 120°C or lower, from the viewpoint of resistance to hot offset and gloss.

[0103] The MEK-insoluble portion of resin AL in amorphous polyester resin AP is preferably 3% by mass or less, more preferably 1% by mass or less, from the viewpoint of low-temperature fixation.

[0104] 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, and even more preferably 60 / 40 or less.

[0105] The glass transition temperature of amorphous polyester resin AP is preferably 40°C or higher, more preferably 50°C or higher, and preferably 80°C or lower, more preferably 70°C or lower, from the viewpoint of resistance to hot offset and gloss.

[0106] The acid value of the amorphous polyester resin AP is preferably 1 mg KOH / g or more, more preferably 2 mg KOH / g or more, and more preferably 20 mg KOH / g or less, and more preferably 18 mg KOH / g or less, from the viewpoint of hot offset resistance and gloss.

[0107] The MEK-insoluble content of amorphous polyester resin AP is preferably 5% by mass or more, more preferably 10% by mass or more, and preferably 20% by mass or less, and more preferably 15% by mass or less, from the viewpoint of hot offset resistance. If the amorphous polyester resin AP consists of two or more resins, it is the weighted average value of each resin.

[0108] The content of amorphous polyester resin AP in the binder resin composition is preferably 30% by mass or more, more preferably 40% by mass or more, even more preferably 50% by mass or more, and preferably 80% by mass or less, more preferably 75% by mass or less, and even more preferably 70% by mass or less.

[0109] Other resins that may be contained in the binder resin composition 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.

[0110] Furthermore, the present invention provides a toner for electrostatic image development that contains the toner binder resin composition of the present invention as a binder resin (binding agent).

[0111] The content of the binder resin composition in the toner is preferably 60% by mass or more, more preferably 70% by mass or more, and preferably less than 100% by mass, more preferably 95% by mass or less, and even more preferably 93% by mass or less.

[0112] The toner of the present invention may contain additives other than the binder resin composition, such as colorants, release agents, charge control agents, magnetic powders, flowability improvers, conductivity modifiers, reinforcing fillers such as fibrous materials, antioxidants, and cleaning properties improvers.

[0113] As colorants, dyes, pigments, magnetic materials, etc., used as colorants for toners can be used. Examples include carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, isoindoline, disazo yellow, etc. In this invention, the toner may be either black toner or color toner.

[0114] From the viewpoint of improving the toner's image density and low-temperature fixability, the colorant content is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 40 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of the binder resin composition.

[0115] Examples of mold release agents include hydrocarbon waxes and their oxides, such as polypropylene wax, polyethylene wax, ethylene propylene copolymer wax, microcrystalline wax, paraffin wax, and Fischer-Tropsch wax; ester waxes such as carnauba wax, montane wax and their deoxidizing waxes, and fatty acid ester waxes; and fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts, etc., which can be used individually or in combination of two or more.

[0116] The melting point of the release agent is preferably 60°C or higher, more preferably 70°C or higher, from the viewpoint of toner transferability, and preferably 160°C or lower, more preferably 140°C or lower, and even more preferably 120°C or lower, from the viewpoint of low-temperature fixation.

[0117] The release agent content is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, even more preferably 1.5 parts by mass or more, and preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and even more preferably 7 parts by mass or less, from the viewpoint of low-temperature fixation and offset resistance of the toner and dispersibility in the binder resin composition, per 100 parts by mass of the binder resin composition.

[0118] The charge control agent is not particularly limited and may contain either a positively charged charge control agent or a negatively charged charge control agent.

[0119] Positively charged charge control agents include nigrosine dyes, such as "Nigrosine Base EX," "Oil Black BS," "Oil Black SO," "Bontron N-01," "Bontron N-04," "Bontron N-07," "Bontron N-09," "Bontron N-11," and "Bontron N-79" (all manufactured by Orient Chemical Industries, Ltd.); triphenylmethane-based dyes containing tertiary amines as side chains; quaternary ammonium salt compounds, such as "Bontron P-51" (manufactured by Orient Chemical Industries, Ltd.), cetyltrimethylammonium bromide, and "COPY CHARGE PX." Examples include VP435 (manufactured by Clariant), polyamine resins such as AFP-B (manufactured by Orient Chemical Industries, Ltd.), imidazole derivatives such as PLZ-2001 and PLZ-8001 (both manufactured by Shikoku Chemicals, Ltd.), and styrene-acrylic resins such as FCA-701PT and FCA-201-PS (manufactured by Fujikura Chemicals, Ltd.).

[0120] Furthermore, as negative charge control agents, metal-containing azo dyes, such as "Barifast Black 3804," "Bontron S-31," "Bontron S-32," "Bontron S-34," and "Bontron S-36" (all manufactured by Orient Chemical Industries, Ltd.), "Eisenspiron Black TRH," and "T-77" (manufactured by Hodogaya Chemical Co., Ltd.); metal compounds of benzyl acid compounds, such as "LR-147" and "LR-297" (both manufactured by Nippon Carlit Co., Ltd.); metal compounds of salicylic acid compounds, such as "Bontron E-81," "Bontron E-84," "Bontron E-88," and "Bontron E-304" (all manufactured by Orient Chemical Industries, Ltd.), and "TN-105" (manufactured by Hodogaya Chemical Co., Ltd.); copper phthalocyanine dyes; and quaternary ammonium salts, such as "COPY CHARGE NX" Examples include VP434 (manufactured by Clariant), nitroimidazole derivatives, organometallic compounds, etc.

[0121] From the viewpoint of the charge stability of the toner, the content of the charge control agent is preferably 0.01 parts by mass or more, more preferably 0.2 parts by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, even more preferably 3 parts by mass or less, and even more preferably 2 parts by mass or less, per 100 parts by mass of the binder resin composition. If the charge control agent is a resin (polymer type), it is preferably 3 parts by mass or more, more preferably 5 parts by mass or more, and preferably 20 parts by mass or less, and even more preferably 15 parts by mass or less, per 100 parts by mass of the binder resin.

[0122] The toner of the present invention may be obtained by any of the conventionally known methods, such as the melt-kneading method, the emulsification-coagulation method, or the suspension polymerization method, and may also be a toner having a core-shell structure. However, from the viewpoint of the mixability of the toner raw materials, pulverized toner is preferred, and pulverized toner obtained by the melt-kneading method, that is, pulverized toner obtained by a method including the steps of melt-kneading the raw materials and pulverizing the resulting mixture, is more preferred. Specifically, for example, raw materials such as a binder resin composition, a colorant, a release agent, and a charge control agent can be uniformly mixed in a mixer such as a Henschel mixer, then melt-kneaded in a closed-type kneader, a single-screw or twin-screw extruder, an open-roll type kneader, etc., and then cooled, pulverized, and classified to produce the toner. In the production of toner, if the binder resin composition consists of two or more resins, a binder resin composition with the resins mixed in advance may be used, or those resins may be directly added to the raw materials when producing the toner.

[0123] In order to improve the fluidity of the toner of the present invention, it is preferable to use external additives. Examples of external additives include inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide, and zinc oxide, and organic fine particles such as melamine resin fine particles and polytetrafluoroethylene resin fine particles, and two or more types may be used in combination.

[0124] Examples of hydrophobic agents used to hydrophobize the surface of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), cyclic silazane, silicone oil, aminosilane, octyltriethoxysilane (OTES), and methyltriethoxysilane.

[0125] From the viewpoint of the toner's chargeability, fluidity, and transferability, the average particle size of the external additive is preferably 5 nm or larger in the case of inorganic fine particles, preferably 250 nm or smaller, more preferably 200 nm or smaller, and even more preferably 90 nm or smaller. In the case of organic fine particles, it is preferably 5 nm or larger, more preferably 300 nm or larger, even more preferably 400 nm or larger, and preferably 800 nm or smaller, more preferably 700 nm or smaller, and even more preferably 600 nm or smaller.

[0126] External additive treatment, which involves mixing toner particles with external additives, can be carried out according to conventional methods, and a mixer such as a Henschel mixer can be used.

[0127] From the viewpoint of the toner's electrostatic properties, fluidity, and transferability, the content of the external additive is preferably 0.05 parts by mass or more, more preferably 0.1 parts by mass or more, even more preferably 0.3 parts by mass or more, and preferably 5 parts by mass or less, and more preferably 4 parts by mass or less, per 100 parts by mass of toner particles before treatment with the external additive.

[0128] The volume-intermediate particle size (D) of the toner of the present invention 50 The volume median particle size (D) is preferably 3 μm or more, more preferably 4 μm or more, and preferably 15 μm or less, more preferably 10 μm or less. 50 ) refers to the particle size at which the cumulative volume frequency calculated using volume fractions accounts for 50% when calculated from the smallest particle size. Furthermore, if the toner is treated with an external additive, the volume median particle size of the toner particles before treatment with the external additive is taken as the volume median particle size of the toner.

[0129] The toner of the present invention can be used as is as a one-component developing toner, or as a two-component developing toner used in combination with a carrier, in image forming apparatuses using either a one-component developing method or a two-component developing method, respectively. [Examples]

[0130] The present invention will be specifically described below with reference to examples, but the present invention is not limited in any way by these examples. The physical properties of resins, etc., can be measured by the following methods.

[0131] [Methyl ethyl ketone (MEK) insoluble components of composite resins] (1) Sample preparation Using JIS Z8801 sieves, collect a powdered sample that passes through a 22-mesh sieve but not a 30-mesh sieve. If the sample is in the form of lumps, crush it using a commercially available hammer or coffee grinder, and then sift the resulting powder.

[0132] (2) Dissolution of the sample 2-1. Weigh 2,000 g of the sample into a glass bottle (manufactured by Kashiwayo Glass Co., Ltd., M-140), add 95 g of MEK, and attach the inner and outer lids. 2-2. Stir in a ball mill for 5 hours (peripheral speed: 200 mm / sec). 2-3. Let it stand for 10 hours.

[0133] (3) Filtration 3-1. Prepare a glass filter (mesh size 11G-3) attached to a pre-weighed (to the nearest 1 / 1000 g) round-bottom flask (mass A (g)). Use a rubber stopper that allows for reduced pressure to seal the glass filter. 3-2. Take 20 mL of the supernatant from the solution that has been allowed to stand for 10 hours in 2-3 using a measuring pipette, and filter it under reduced pressure using the glass filter prepared in 3-1. The supernatant should be the liquid up to 2 cm below the surface. Adjust the pressure inside the round-bottom flask to 40 kPa before filtering the solution. 3-3. Draw up 20 mL of unused MEK using a measuring pipette and filter the soluble components adhering to the glass filter under reduced pressure.

[0134] (4) Drying 4-1. Remove MEK from the round-bottom flask using an evaporator. Water bath temperature: 70℃ Round-bottom flask rotation speed: 200 r / min Reduced pressure inside the round-bottom flask during MEK removal: Adjusted to 40-20kPa Time: 10 minutes 4-2. After drying at 50°C for 1 torr for 12 hours, weigh the mass B (g) of the round-bottom flask.

[0135] (5) Calculation of MEK-insoluble content in composite resins 5-1. Calculate the soluble portion X (g) of MEK dissolved in 20 mL of MEK. X=BA 5-2. Calculate the soluble content Y (g) of MEK dissolved in 95g of MEK, assuming a specific gravity of 0.805 for MEK. Y = X × 95 / (20 × 0.805) 5-3. MEK insoluble content (g)=2.000-Y The MEK-insoluble content (g) is calculated as the average of three measurements.

[0136] [Methyl ethyl ketone (MEK) insoluble content in amorphous polyester resins] The sample preparation and drying are carried out in the same manner as in (1) to (4) above for the methyl ethyl ketone (MEK) insoluble portion of the composite resin. (5) Calculation of MEK-insoluble content in resin 5-1. Calculate the soluble portion X (g) of MEK dissolved in 20 mL of MEK. X=BA 5-2. Calculate the soluble content Y (g) of MEK dissolved in 95g of MEK, assuming a specific gravity of 0.805 for MEK. Y = X × 95 / (20 × 0.805) 5-3. Calculate the soluble content Z (mass%) per gram of sample. Z = Y / 2 × 100 5-4. MEK insoluble content (mass%) = 100-Z The MEK-insoluble content (mass%) is the average of three measurements.

[0137] [Mass of addition polymerization resin segments in composite resins] 2,000 g of composite resin is dissolved in tetrahydrofuran to a concentration of 5 g / 100 mL, and 10 g of 5% by mass sodium hydroxide aqueous solution is added and mixed to hydrolyze the polyester resin segment. Then, ethanol is added in small amounts to reprecipitation, and only the addition polymerization resin segment is separated and its mass is measured.

[0138] [Methyl ethyl ketone (MEK) insoluble content in addition polymerization resin segments] Using an addition polymerization resin segment (mass Sg) as the sample, the sample preparation and drying are carried out in the same manner as (1) to (4) above for [methyl ethyl ketone (MEK) insoluble portion of composite resin]. (5) Calculation of MEK-insoluble content in addition polymerization resin segments 5-1. Calculate the soluble portion X (g) of MEK dissolved in 20 mL of MEK. X=BA 5-2. Calculate the soluble content Y (g) of MEK dissolved in 95g of MEK, assuming a specific gravity of 0.805 for MEK. Y = X × 95 / (20 × 0.805) 5-3. MEK insoluble content (g) = SY The MEK-insoluble content (g) is calculated as the average of three measurements.

[0139] [Softening point of resin] Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), 1 g of sample is heated at a heating rate of 6°C / min while a load of 1.96 MPa is applied by a plunger, and the sample is extruded from a nozzle with a diameter of 1 mm and a length of 1 mm. The amount of plunger descent of the flow tester is plotted against temperature, and the temperature at which half of the sample has flowed out is defined as the softening point.

[0140] [Maximum peak temperature of endothermic resin] Using a differential scanning calorimeter "Q-100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.01 to 0.02 g of the sample is weighed into an aluminum pan and cooled from room temperature (25°C) to 0°C at a rate of 10°C / min, and maintained at 0°C for 1 minute. Then, measurements are taken at a rate of 10°C / min. Among the observed endothermic peaks, the temperature of the peak with the largest peak area is defined as the maximum endothermic peak temperature. For crystalline resins, the maximum endothermic peak temperature is defined as the melting point.

[0141] [Glass transition temperature of resins] Using a differential scanning calorimeter "Q-100" (manufactured by T.A. Instruments Japan Co., Ltd.), 0.01 to 0.02 g of the sample is weighed into an aluminum pan and heated from room temperature (20°C) to 200°C at a heating rate of 10°C / min, and then cooled to 0°C at a cooling rate of 10°C / min. Next, the sample is heated at a heating rate of 10°C / min and the endothermic peak is measured. The temperature at the intersection of the extension of the baseline below the maximum endothermic peak temperature and the tangent line showing the maximum slope from the rising part of the peak to the peak apex is defined as the glass transition temperature.

[0142] [Acid value of resins] Measurements will be performed according to the method of JIS K 0070:1992. However, the measurement solvent will be changed from the ethanol and ether mixed solvent specified in JIS K 0070 to an acetone and toluene mixed solvent (acetone:toluene = 1:1 (volume ratio)) for amorphous resins, and to tetrahydrofuran for crystalline resins.

[0143] [Weight-average molecular weight of resins] The molecular weight distribution is measured by gel permeation chromatography (GPC) using the following method, and the weight-average molecular weight is determined. (1) Preparation of sample solution Dissolve the sample in tetrahydrofuran at 40 °C so that the concentration becomes 0.5 g / 100 mL. Then, filter this solution using a PTFE type membrane filter "DISMIC-25JP" (manufactured by ADVANTEC) with a pore size of 0.20 μm to remove insoluble components, and obtain a sample solution. (2) Molecular weight measurement Using the following measuring device and analytical column, flow tetrahydrofuran as an eluent at a flow rate of 1 mL per minute to stabilize the column in a thermostat at 40 °C. Inject 100 μL of the sample solution there and perform the measurement. The molecular weight of the sample is calculated based on a calibration curve prepared in advance. For the calibration curve at this time, several types of monodisperse polystyrenes (A-500 (5.0×10 2 ), A-1000 (1.01×10 3 ), A-2500 (2.63×10 3 ), A-5000 (5.97×10 3 ), F-1 (1.02×10 4 ), F-2 (1.81×10 4 ), F-4 (3.97×10 4 ), F- - 10 (9.64×10 4 ), F-20 (1.90×10 5 ), F-40 (4.27×10 5 ), F-80 (7.06×10 5 ), F-128 (1.09×10 6 )) manufactured by Tosoh Corporation are used as standard samples. The values in parentheses indicate the molecular weights. Measuring device: HLC-8220GPC (manufactured by Tosoh Corporation) Analytical column: TSKgel GMH XL +TSKgel G3000H XL (manufactured by Tosoh Corporation)

[0144] [Melting point of the release agent] Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), weigh 0.02 g of the sample into an aluminum pan, heat it up to 200 °C, then cool it from 200 °C to 0 °C at a cooling rate of 10 °C / min. Then, heat the sample at a heating rate of 10 °C / min and measure the heat quantity, and take the maximum peak temperature of the endotherm as the melting point.

[0145] [Average particle size of external additives] The average particle diameter refers to the number-average particle diameter, which is calculated by measuring the particle size (average of the major and minor axes) of 500 particles (primary particles) from scanning electron microscope (SEM) images and using the number-average value of these measurements.

[0146] [Medium particle size in toner volume] • Measuring instrument: "Coulter Multisizer (Registered Trademark) III" (manufactured by Beckman Coulter, Inc.) • Aperture diameter: 100 μm • Analysis software: "Multisizer III (registered trademark) Version 3.51" (manufactured by Beckman Coulter, Inc.) • Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) • Dispersion: Prepared by dissolving polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" [manufactured by Kao Corporation, HLB (Griffin) = 13.6] in the electrolyte to adjust the concentration to 5% by mass. • Dispersion conditions: Add 10 mg of the sample to 5 mL of the dispersion and disperse for 1 minute using an ultrasonic disperser (machine name: US-1 manufactured by SND Corporation, output: 80W). Then, add 25 mL of electrolyte and disperse for another minute using the ultrasonic disperser to prepare the sample dispersion. • Measurement conditions: The sample dispersion is added to 100 mL of the electrolyte to adjust the concentration so that the particle size of 30,000 particles can be measured in 20 seconds. Then, the 30,000 particles are measured, and the volume median particle size (D) is determined from the particle size distribution. 50 )

[0147] Production Example 1 of Addition Polymerization Resins 10% of each raw material monomer shown in Table 1, along with an equal amount of methyl ethyl ketone, the chain transfer agent, and the polymerization initiator shown in Table 1, were placed in a 2-liter four-necked flask equipped with a dehydration tube with a nitrogen inlet, a stirrer, and a thermocouple, and the temperature was raised to 80°C. Then, a mixture of the remaining raw material monomers and an equal amount of methyl ethyl ketone was prepared and added dropwise at a rate of 4.2 g / min. The mixture was then reduced under 20 kPa for 4 hours to remove the methyl ethyl ketone from the system, yielding addition polymerization resins (resins B1-B10). A total of 700 g of raw material monomers was used.

[0148] Production Example 2 of Addition Polymerization Resins 700 g of the raw material monomers shown in Table 1 were placed in an autoclave equipped with a stainless steel stirring rod, and the raw material monomers were polymerized under pressurized heating conditions (300°C) for 2 hours. The precipitated resin was recovered by returning to atmospheric pressure and room temperature to obtain an addition polymerization resin (resin B11).

[0149] [Table 1]

[0150] Manufacturing Example 1 of Amorphous Polyester Composite Resin The alcohol component, carboxylic acid component, and esterification catalyst shown in Tables 2-4 were placed in a 10-liter four-necked flask equipped with a dehydration tube with a nitrogen inlet, a stirrer, and a thermocouple. The mixture was heated to 235°C and reacted at 235°C for 8 hours. After that, the pressure in the flask was reduced, and a vacuum reaction was carried out at 8 kPa for 1 hour. The mixture was then cooled to 210°C, the addition polymerization resin was added, and the mixture was heated to 235°C and reacted at 235°C for 1 hour. After that, the pressure in the flask was reduced to 8 kPa, and it was confirmed that the softening point shown in Tables 2-4 was reached to obtain amorphous polyester composite resins (resins AC1-AC13).

[0151] Manufacturing Example 2 of Amorphous Polyester Composite Resin The alcohol component, carboxylic acid component, and esterification catalyst shown in Table 4 were placed in a 10-liter four-necked flask equipped with a dehydration tube with a nitrogen inlet tube, a stirrer, and a thermocouple. The mixture was heated to 235°C and reacted at 235°C for 8 hours. After that, the pressure in the flask was reduced, and a vacuum reaction was carried out at 8 kPa for 1 hour. The mixture was then cooled to 180°C, the addition polymerization resin was added, and the mixture was heated to 180°C and reacted at 180°C for 4 hours. After that, the temperature was raised to 230°C and the mixture was reacted for 1 hour. The pressure in the flask was then reduced to 8 kPa, and it was confirmed that the softening point shown in Table 4 had been reached to obtain an amorphous polyester composite resin (resin AC14).

[0152] [Table 2]

[0153] [Table 3]

[0154] [Table 4]

[0155] Manufacturing Example 1 of Crystalline Polyester Resin As shown in Table 5, the alcohol and carboxylic acid components were placed in a 10-liter four-necked flask equipped with a dehydration tube with a nitrogen inlet, a stirrer, and a thermocouple. The mixture was heated to 140°C and reacted at 140°C for 1 hour. Subsequently, the temperature was gradually increased to 200°C at 10°C / h and the mixture was reacted at 200°C for 1 hour. After that, the esterification catalyst was added and the mixture was reacted for 1 hour. Then, the pressure in the flask was reduced, and a vacuum reaction was carried out at 8 kPa for 2 hours to obtain a crystalline polyester resin (resin CP1).

[0156] [Table 5]

[0157] Manufacturing Example 1 of Amorphous Polyester Resin As shown in Table 6, the alcohol component, terephthalic acid, and esterification catalyst were placed in a 10-liter four-necked flask equipped with a dehydration tube with a nitrogen inlet, a stirrer, and a thermocouple. The mixture was heated to 235°C and reacted at 235°C for 5 hours. The pressure in the flask was then reduced, and a vacuum reaction was carried out at 8 kPa for 1 hour. After that, the mixture was cooled to 210°C, trimellitic acid and dodecenyl succinic anhydride were added, the temperature was raised to 210°C, and the mixture was reacted at 210°C for 1 hour. The pressure in the flask was then reduced to 8 kPa, and it was confirmed that the softening point shown in Table 6 had been reached to obtain amorphous polyester resin (resin AP1).

[0158] Manufacturing Example 2 of Amorphous Polyester Resin The alcohol component, carboxylic acid component, and esterification catalyst shown in Table 6 were placed in a 10-liter four-necked flask equipped with a dehydration tube with a nitrogen inlet tube, a stirrer, and a thermocouple. The mixture was heated to 235°C and reacted at 235°C for 8 hours. After that, the pressure in the flask was reduced to 8 kPa, and it was confirmed that the softening point shown in Table 6 had been reached to obtain amorphous polyester resin (resin AP2).

[0159] [Table 6]

[0160] Examples 1-10 and Comparative Examples 1-5 Mix 100 parts by mass of the binder resin composition shown in Table 7, 8 parts by mass of the coloring agent "ECB-301" (manufactured by Dainichi Seika Kogyo Co., Ltd., phthalocyanine blue), 2 parts by mass of the release agent "HNP-9" (manufactured by Nippon Seiro Co., Ltd., paraffin wax, melting point: 79℃), and 5 parts by mass of the positively charged charge control agent "FCA-201-PS" (manufactured by Fujikura Kasei Co., Ltd.). Stir the mixture using a Henschel mixer at a rotation speed of 1500 r / min (peripheral speed 21.6 m / sec) for 3 minutes, and then extrude it in a co-rotating twin-screw extruder (manufactured by Ikegai Co., Ltd., product name: PCM-30, shaft diameter 2.9 cm, shaft cross-sectional area 7.06 cm²). 2The mixture was melt-kneaded using a roller. The roller rotation speed was 200 r / min (peripheral speed 0.30 m / sec), the barrel temperature was set to 1000°C, and the feed rate of the mixture was 10 kg / h (mixture feed rate per unit cross-sectional area of ​​the shaft 1.42 kg / h·cm). 2 ) was.

[0161] The resulting mixture was rolled and cooled using cooling rolls, and then coarsely ground to approximately 1 mm using a hammer mill. The resulting coarsely ground material was finely ground and classified using an air-jet mill (manufactured by Nippon Pneumatic Co., Ltd., product name: IDS), and the medium volume particle size (D 50 ) yielded toner particles with a size of 7.0 μm.

[0162] 100 parts by mass of the obtained toner particles were mixed with 0.5 parts by mass of hydrophobic silica "TG-820F" (manufactured by Cabot Specialty Chemicals Inc., hydrophobic treatment agent: hexamethyldisilazane, average particle size: 8 nm), 2.0 parts by mass of hydrophobic silica "NA-50Y" (manufactured by Nippon Aerosil Co., Ltd., hydrophobic treatment agent: silicone oil, average particle size: 30 nm), and 0.4 parts by mass of polytetrafluoroethylene fine particles "KTL-500F" (manufactured by Kitamura Co., Ltd., average particle size: 500 nm) in a Henschel mixer at 2100 r / min (peripheral speed 29 m / sec) for 3 minutes to obtain toner.

[0163] Test Example 1 [Low Temperature Fixation] A commercially available non-magnetic single-component color printer (Brother Industries, Ltd., HL-3240CDW) was modified to allow the extraction of unfixed images, and a solid image (toner load 0.30 mg / cm²) was created. 2An unfixed image was obtained by printing ) onto the printed material. Then, using a fuser (fixing speed 400 mm / sec), the fixing test of the unfixed printed material was performed at each temperature while sequentially increasing the temperature of the fuser roll from 150°C to 220°C in 5°C increments. Cellophane adhesive tape "UNICEF Cellophane" (manufactured by Mitsubishi Pencil Co., Ltd., width: 18 mm, JIS Z1522:2009) was attached to the image portion of the obtained printed material, and it was passed through a fuser roller set to 30°C, separate from the fuser roll of the fuser, and then the tape was peeled off. The optical reflectance density before and after the tape was applied was measured using a reflectance densitometer "RD-915" (manufactured by Gretag Macbeth Co., Ltd.), and the temperature of the fuser roll at which the ratio of the two (after peeling / before application × 100) first exceeded 90% was defined as the minimum fixing temperature. The results are shown in Table 7. The lower the minimum fixing temperature, the better the low-temperature fixing performance. The fuser paper used is "CopyBond SF-70NA" (manufactured by Sharp Corporation, 75g / m²). 2 ) was used.

[0164] Test Example 2 [Hot Offset Resistance] A commercially available non-magnetic single-component color printer (Brother Industries, Ltd., HL-3240CDW) was modified to allow the extraction of unfixed images, and a solid image (toner load 0.30 mg / cm²) was created. 2 An unfixed image was obtained by printing ). Next, the same printer was prepared with a fuser modified to have variable temperature and variable printing speed. The fuser temperature was gradually increased from 160°C to 240°C in 5°C increments at a rate of 2.0 seconds per sheet in the A4 portrait direction, and fixing tests were performed on unfixed printed materials at each temperature. The images of the obtained printed materials were visually observed to confirm the temperature at which hot offset occurred, and the hot offset resistance was evaluated. The results are shown in Table 7. The higher the temperature at which hot offset occurs, the better the hot offset resistance.

[0165] The difference between the minimum fixing temperature obtained in Test Example 1 and the hot offset occurrence temperature obtained in Test Example 2 was calculated and evaluated as the fixing width. The results are shown in Table 7.

[0166] [Table 7]

[0167] From the above results, it can be seen that the toners of Examples 1 to 10 have good low-temperature fixability, hot offset resistance, and image gloss, compared to Comparative Examples 1 to 5, which do not contain amorphous polyester composite resins with adjusted softening point and predetermined MEK insoluble content. [Industrial applicability]

[0168] The toner for electrostatic image development containing the toner binder resin composition of the present invention is suitably used for developing latent images formed in electrostatic image development methods, electrostatic recording methods, electrostatic printing methods, and the like.

Claims

1. A binder resin composition for toner containing an amorphous polyester composite resin AC in which a polyester resin segment and an addition polymerization resin segment are bonded together via covalent bonds, wherein the content of methyl ethyl ketone insoluble material not derived from the addition polymerization resin segment is 10% by mass or more and 20% by mass or less in the amorphous polyester composite resin AC, and the softening point of the amorphous polyester composite resin AC is 100°C or more and 115°C or less.

2. The toner binder resin composition according to claim 1, wherein the weight-average molecular weight of the addition polymerization resin segment is 10,000 or more and 22,000 or less.

3. The toner binder resin composition according to claim 1 or 2, wherein the acid value of the addition polymerization resin segment is 140 mg KOH / g or more and 280 mg KOH / g or less.

4. The toner binder resin composition according to claim 1 or 2, wherein the content of the addition polymerization resin segment is 5% by mass or more and 20% by mass or less in the amorphous polyester composite resin AC.

5. The toner binder resin composition according to claim 1 or 2, wherein the acid value of the amorphous polyester composite resin AC is 10 mg KOH / g or less.

6. Furthermore, the toner binder resin composition according to claim 1 or 2 contains a crystalline polyester resin CP.

7. The toner binder resin composition according to claim 6, wherein the crystalline polyester resin CP is a polycondensate of an alcohol component containing ethylene glycol and a carboxylic acid component.

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

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