Method for manufacturing toner for electrostatic charge image development

Abstract

To provide a method for manufacturing a toner for electrostatic charge image development which is excellent in low temperature fixability and image density.SOLUTION: There is provided a method for manufacturing a toner for electrostatic charge image development containing a crystalline polyester resin C, an amorphous resin A, and a coloring agent, wherein the crystalline polyester resin C is a polycondensate of an alcohol component containing aliphatic diol having 8 to 14 carbon atoms, and a carboxylic acid component containing an aliphatic dicarboxylic compound having 4 carbon atoms; the method includes a step of melt-kneading a mixture containing the crystalline polyester resin C, the amorphous resin A and the coloring agent using an open roll type biaxial kneader having two rolls having different peripheral speeds; and the temperature on the discharge side of the kneaded product of a high rotation roll of the open roll type biaxial kneader is -20°C or higher and +15°C or lower than the melting point of the crystalline polyester resin C.SELECTED DRAWING: None

Description

Technical Field

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

Background Art

[0002] As a binder resin for toner, it is known that a crystalline polyester resin is effective in improving the low-temperature fixability of toner, and its combined use with an amorphous resin has been studied.

[0003] Patent Document 1 discloses an electrophotographic toner containing a binder resin and a predetermined amide compound, wherein the binder resin contains a crystalline polyester and an amorphous resin.

[0004] Patent Document 2 includes an amorphous polyester resin, a crystalline polyester resin, and a release agent, wherein the crystalline polyester resin and the release agent are dispersed in the amorphous polyester resin. Here, when the average dispersion diameter of the crystalline polyester resin is defined as the first average dispersion diameter and the average dispersion diameter of the release agent is defined as the second average dispersion diameter, a toner is disclosed in which the ratio of the second average dispersion diameter to the first average dispersion diameter is 6 or more and 12 or less.

[0005] Patent Document 3 has a crystalline resin and an amorphous resin, and in X-ray diffraction measurement, diffraction peaks exist at least at positions of 2θ = 20° to 25°, and when heating and cooling are performed under a predetermined heating and cooling condition 1 using a differential scanning calorimeter (DSC) and the glass transition temperature observed in the last heating step and heating and cooling are performed under a predetermined heating and cooling condition 2 and the glass transition temperature observed in the last heating step, a toner is disclosed in which the difference therebetween is within 10°C.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

[0007] However, when manufacturing a pulverized toner using a crystalline polyester resin, if the crystalline polyester resin is not sufficiently dispersed in the amorphous resin by melt kneading, the dispersibility remains insufficient even after subsequent cooling and toner formation. As a result, the low-temperature fixability, which is a characteristic of the crystalline polyester resin, is not fully exhibited. Also, it is thought that the crystalline polyester resin with reduced dispersibility hinders the color developability of the colorant, resulting in a decrease in image density.

[0008] The present invention relates to a method for manufacturing an electrostatic charge image developing toner excellent in low-temperature fixability and image density. [Means for Solving the Problems]

[0009] The present invention is a method for manufacturing an electrostatic charge image developing toner containing a crystalline polyester resin C, an amorphous resin A, and a colorant, wherein the crystalline polyester resin C is a polycondensate of an alcohol component containing an aliphatic diol having 8 to 14 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 4 carbon atoms, and includes a step of melt kneading a mixture containing the crystalline polyester resin C, the amorphous resin A, and the colorant using an open roll type twin-screw kneader equipped with two rolls having different peripheral speeds, and the temperature on the kneaded product discharge side of the high-speed rotation roll of the open roll type twin-screw kneader is -20°C or more and +15°C or less than the melting point of the crystalline polyester resin C. The present invention relates to a method for manufacturing an electrostatic charge image developing toner. [Effects of the Invention]

[0010] The toner for electrostatic charge image development obtained by the method of the present invention exhibits excellent effects in terms of low-temperature fixability and improvement of image density.

Embodiments for Carrying Out the Invention

[0011] In the present invention, when manufacturing a toner for electrostatic charge image development containing a crystalline polyester resin, an amorphous resin, and a colorant, the crystalline polyester resin is a polycondensate of raw material monomers containing a specific aliphatic monomer, and in the melt-kneading step, it has a major feature in that an open-roll type twin-screw kneader with a high-speed roll adjusted to a predetermined temperature is used. The reason why the toner for electrostatic charge image development obtained by the method of the present invention is excellent in low-temperature fixability and image density is not clear, but it is presumed as follows.

[0012] In the present invention, by using an open-roll type twin-screw kneader with high kneading strength and easy temperature control, the dispersibility of the crystalline polyester resin in the amorphous resin is improved. However, when an open-roll type twin-screw kneader is used for melt-kneading the raw material mixture, if the temperature on the kneaded product discharge side of the high-speed roll is too low, part of the crystalline polyester resin crystallizes during kneading, resulting in a decrease in dispersibility in the amorphous resin. On the other hand, if the temperature on the kneaded product discharge side of the high-speed roll is too high, the viscosity of the crystalline polyester resin decreases, resulting in a decrease in dispersibility in the amorphous resin, and in either case, it is not reflected in the improvement of low-temperature fixability. Furthermore, it is presumed that the crystalline polyester resin with decreased dispersibility hinders the color development property of the colorant, resulting in a decrease in image density. In contrast, in the present invention, the temperature on the kneaded product discharge side of the open-roll type twin-screw kneader is controlled near the melting point of the crystalline polyester resin. Furthermore, since the crystalline polyester resin can interact with the hydrophobic part of the colorant by containing an aliphatic diol having 8 to 14 carbon atoms as an alcohol component and can interact with the hydrophilic part of the colorant by containing an aliphatic dicarboxylic acid compound having 4 carbon atoms as a carboxylic acid component, there exists a crystalline polyester resin with improved dispersibility in the amorphous resin. Thus, it is considered that the dispersibility of the colorant is also improved, and a toner excellent in low-temperature fixability and image density can be obtained.

[0013] In the present invention, the crystalline polyester resin C is a polycondensate of an alcohol component containing an aliphatic diol having 8 to 14 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 4 carbon atoms.

[0014] The crystallinity of the resin is represented by a crystallinity index defined as the ratio of the softening point to the maximum peak temperature of endotherm measured by a differential scanning calorimeter, i.e., [softening point / maximum peak temperature of endotherm]. The crystalline resin has a crystallinity index of 0.6 or more, preferably 0.7 or more, more preferably 0.9 or more, and is a resin of 1.4 or less, preferably 1.2 or less, more preferably 1.1 or less. On the other hand, the amorphous resin is a resin in which no endothermic peak is observed, or when an endothermic peak is observed, the crystallinity index exceeds 1.4, preferably exceeds 1.5, more preferably is 1.6 or more, or is a resin of less than 0.6, preferably 0.5 or less. The crystallinity of the resin can be adjusted by the type and ratio of the raw material monomers, and production conditions (for example, 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 crystalline resin, the maximum peak temperature of endotherm is taken as the melting point.

[0015] Examples of the aliphatic diol having 8 to 14 carbon atoms include 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,12-dodecanediol, 1,14-tetradecanediol, etc.

[0016] From the viewpoint of hydrophobicity, the number of carbon atoms of the aliphatic diol is 8 or more, preferably 10 or more, and from the viewpoint of low-temperature fixability, it is 14 or less, preferably 12 or less.

[0017] The content of the aliphatic diol having 8 to 14 carbon atoms in the alcohol component 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, still more preferably 100 mol%.

[0018] Examples of alcohol components other than aliphatic diols having 8 to 14 carbon atoms include aliphatic diols having 7 or fewer carbon atoms such as 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,7-heptanediol, aliphatic diols having 15 or more carbon atoms, aromatic diols such as alkylene oxide adducts of bisphenol A, and polyhydric alcohols having 3 or more valences such as bisphenol A, hydrogenated bisphenol A, sorbitol, pentaerythritol, glycerin, and trimethylolpropane.

[0019] Examples of the carboxylic acid component as an aliphatic dicarboxylic acid-based compound having 4 carbon atoms include fumaric acid, maleic acid, succinic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms. Among these, fumaric acid, succinic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms are preferred. Note that the carbon number of the alkyl group in the case where the aliphatic dicarboxylic acid-based compound is an alkyl ester is not included in the above carbon number (4).

[0020] The content of the aliphatic dicarboxylic acid-based compound having 4 carbon atoms in the carboxylic acid component 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 still more preferably 100 mol%.

[0021] Examples of carboxylic acid components other than the aliphatic dicarboxylic acid-based compound having 4 carbon atoms include aliphatic dicarboxylic acid-based compounds having 3 or fewer carbon atoms, aliphatic dicarboxylic acid-based compounds having 5 or more carbon atoms, aromatic dicarboxylic acid-based compounds, and polyhydric carboxylic acid-based compounds having 3 or more valences.

[0022] In addition, the alcohol component may appropriately contain a monohydric alcohol, and the carboxylic acid component may appropriately contain a monohydric carboxylic acid-based compound.

[0023] The equivalent ratio of the carboxyl group of the carboxylic acid component to the hydroxyl group of the alcohol component (COOH group / OH group) is preferably 0.8 or more, more preferably 0.9 or more, from the viewpoint of image density, and is preferably 1.2 or less, more preferably 1.1 or less, from the viewpoint of low-temperature fixability.

[0024] The crystalline polyester resin C can be produced, for example, by polycondensing an alcohol component and a carboxylic acid component in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and further, if necessary, in the presence of an esterification co-catalyst, a polymerization inhibitor, etc., preferably at a temperature of 120°C or higher and 230°C or lower.

[0025] Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and tin(II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropylate bistriethanolamineate. The amount of the esterification catalyst used is preferably 0.01 part by mass or more, more preferably 0.1 part by mass or more, and preferably 1.5 parts by mass or less, more preferably 1 part by mass or less, based on 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Examples of the esterification co-catalyst include gallic acid. The amount of the esterification co-catalyst used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and preferably 0.5 part by mass or less, more preferably 0.1 part by mass or less, based on 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. Examples of the polymerization inhibitor include t-butylcatechol. The amount of the polymerization inhibitor used is preferably 0.001 part by mass or more, more preferably 0.01 part by mass or more, and preferably 0.5 part by mass or less, more preferably 0.1 part by mass or less, based on 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component.

[0026] In the present invention, the polyester resin may be a polyester resin modified to such an extent that its properties are not substantially impaired. Examples of the modified polyester resin include polyester resins grafted or blocked with phenol, urethane, epoxy, etc. by the methods described in JP-A-11-133668, JP-A-10-239903, JP-A-8-20636, etc. Among the modified polyester resins, a urethane-modified polyester resin obtained by extending a polyester resin with a polyisocyanate compound is preferred.

[0027] From the viewpoint of storage stability, the softening point of the crystalline polyester resin C is preferably 50°C or higher, more preferably 65°C or higher, still more preferably 70°C or higher, and from the viewpoint of low-temperature fixability, it is preferably 120°C or lower, more preferably 110°C or lower.

[0028] From the viewpoint of storage stability, the melting point of the crystalline polyester resin C is preferably 60°C or higher, more preferably 70°C or higher, and from the viewpoint of low-temperature fixability, it is preferably 130°C or lower, more preferably 120°C or lower.

[0029] From the viewpoint of low-temperature fixability, the acid value of the crystalline polyester resin C is preferably 1 mgKOH / g or higher, more preferably 3 mgKOH / g or higher, and from the viewpoint of image density, it is preferably 20 mgKOH / g or lower, more preferably 15 mgKOH / g or lower.

[0030] From the viewpoint of low-temperature fixability, the content of the crystalline polyester resin C is preferably 1% by mass or higher, more preferably 3% by mass or higher, still more preferably 4% by mass or higher in the total amount of the crystalline polyester resin C and the amorphous resin A, and from the viewpoint of image density, it is preferably 45% by mass or lower, more preferably 40% by mass or lower, still more preferably 30% by mass or lower, still more preferably 20% by mass or lower.

[0031] Examples of the amorphous resin A include amorphous polyester resins, composite resins in which a polyester resin and a styrene resin are bonded, polyamide resins, vinyl resins, epoxy resins, polycarbonate resins, polyurethane resins, and the like. In the present invention, from the viewpoint of improving image density, an amorphous polyester resin or a composite resin is preferable, and an amorphous polyester resin is more preferable.

[0032] As the amorphous polyester resin, a polycondensate of an alcohol component containing an alkylene oxide adduct of bisphenol A and a carboxylic acid component is preferable.

[0033] As the alkylene oxide adduct of bisphenol A, the formula (I):

[0034]

Chemical formula

[0035] (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, and even more preferably 4 or less) The compound represented by is preferable.

[0036] From the viewpoint of low-temperature fixing property, the content of the alkylene oxide adduct of bisphenol A in the alcohol component is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, even more preferably 95 mol% or more, and even more preferably 100 mol%.

[0037] Examples of other alcohol components include aliphatic diols, bisphenol A, hydrogenated bisphenol A, sorbitol, pentaerythritol, glycerin, and polyhydric alcohols such as trimethylolpropane.

[0038] Examples of the carboxylic acid component include aliphatic dicarboxylic acid compounds, aromatic dicarboxylic acid compounds, carboxylic acid compounds with a valency of 3 or more, and the like.

[0039] Examples of the aliphatic dicarboxylic acid compound include fumaric acid, maleic acid, succinic acid, succinic acid derivatives substituted with a hydrocarbon group, glutaric acid, adipic acid, sebacic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0040] Examples of the aromatic dicarboxylic acid compound include phthalic acid, isophthalic acid, terephthalic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0041] Examples of the carboxylic acid compound with a valency of 3 or more include trimellitic acid, pyromellitic acid, anhydrides of these acids, and alkyl esters of these acids having 1 to 3 carbon atoms.

[0042] In the present invention, from the viewpoints of low-temperature fixability and image density, the carboxylic acid component of the amorphous polyester resin preferably contains a succinic acid derivative substituted with a hydrocarbon group.

[0043] The hydrocarbon group in the succinic acid derivative substituted with a hydrocarbon group is preferably an alkyl group or an alkenyl group. Therefore, specific examples of the succinic acid derivative substituted with a hydrocarbon group include dodecyl succinic acid, dodecenyl succinic acid, tetrapropenyl succinic acid, decenyl succinic acid, their acid anhydrides, and alkyl esters of these acids having 1 to 3 carbon atoms. Among these, from the viewpoint of low-temperature fixability, dodecenyl succinic acid, tetrapropenyl succinic acid, or their acid anhydrides are preferable, and dodecenyl succinic anhydride is more preferable.

[0044] From the viewpoint of hydrophobicity, the number of carbon atoms of the hydrocarbon group in the succinic acid derivative is preferably 8 or more, more preferably 10 or more, still more preferably 12 or more, and preferably 20 or less, more preferably 18 or less, still more preferably 16 or less.

[0045] As the succinic acid derivative, from the viewpoint of hydrophobicity, those containing at least one or two or more selected from the group consisting of succinic acid substituted with an alkyl group having 10 to 18 carbon atoms and succinic acid substituted with an alkenyl group having 10 to 18 carbon atoms are preferred, and those containing at least one or two or more selected from the group consisting of succinic acid substituted with an alkyl group having 12 to 16 carbon atoms and succinic acid substituted with an alkenyl group having 12 to 16 carbon atoms are more preferred.

[0046] The content of the succinic acid derivative is preferably 1 mol% or more, more preferably 5 mol% or more, still more preferably 7 mol% or more from the viewpoint of hydrophobicity in the carboxylic acid component, and preferably 40 mol% or less, more preferably 35 mol% or less, still more preferably 20 mol% or less, still more preferably 15 mol% or less from the viewpoint of image density.

[0047] In addition, the alcohol component may appropriately contain a monohydric alcohol, and the carboxylic acid component may appropriately contain a monohydric carboxylic acid compound.

[0048] The equivalent ratio (COOH group / OH group) of the carboxy group of the carboxylic acid component to the hydroxyl group of the alcohol component is preferably 0.6 or more, more preferably 0.7 or more, still more preferably 0.75 or more, and preferably 1.2 or less, more preferably 1.15 or less from the viewpoint of adjusting the softening point of the polyester resin.

[0049] The polycondensation reaction conditions of the alcohol component and the carboxylic acid component of the amorphous polyester resin are the same as those of the crystalline polyester resin except that the suitable reaction temperature is preferably 130°C or more, more preferably 170°C or more, and preferably 250°C or less, more preferably 240°C or less.

[0050] In the composite resin containing the polyester resin and the styrene resin, the polyester resin is the same as the amorphous polyester resin described above, and the styrene resin is an addition polymer of a raw material monomer containing at least styrene or a styrene derivative such as α-methylstyrene or vinyltoluene (hereinafter, styrene and styrene derivatives are collectively referred to as "styrene compounds").

[0051] The content of the styrene compound, preferably styrene, in the raw material monomer of the styrene resin is preferably 50% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more from the viewpoint of image density, and preferably 95% by mass or less, more preferably 93% by mass or less, still more preferably 90% by mass or less from the viewpoint of low-temperature fixability.

[0052] Further, the styrene resin may contain an alkyl (meth)acrylate having 7 or more carbon atoms in the alkyl group as a raw material monomer. Examples of the alkyl (meth)acrylate include 2-ethylhexyl (meth)acrylate, (iso)octyl (meth)acrylate, (iso)decyl (meth)acrylate, and (iso)stearyl (meth)acrylate. It is preferable to use one or more of these. In the present specification, "(iso)" means including both the case where this group is present and the case where it is not, and when these groups are not present, it indicates normal. Further, "(meth)acrylic acid" means acrylic acid, methacrylic acid, or both of them.

[0053] The number of carbon atoms in the alkyl group of the alkyl (meth)acrylate as a raw material monomer of the styrene resin is preferably 7 or more, more preferably 8 or more, and preferably 12 or less, more preferably 10 or less from the viewpoint of improving the low-temperature fixability of the toner. The number of carbon atoms of the alkyl ester refers to the number of carbon atoms derived from the alcohol component constituting the ester.

[0054] The raw material monomers of the styrene resin may include raw material monomers other than styrene compounds and (meth)acrylic acid alkyl esters, such as 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; N-vinyl compounds such as N-vinyl pyrrolidone, etc.

[0055] The addition polymerization reaction of the raw material monomers of the styrene resin can be carried out by a conventional method, for example, in the presence of a polymerization initiator such as dibutyl peroxide and dicumyl peroxide, a polymerization inhibitor, a crosslinking agent, etc., in the presence of an organic solvent or without a solvent. As the temperature condition, it is preferably 110°C or higher, more preferably 140°C or higher, and preferably 200°C or lower, more preferably 170°C or lower.

[0056] When an organic solvent is used in the addition polymerization reaction, xylene, toluene, methyl ethyl ketone, acetone, etc. can be used. The amount of the organic solvent used is preferably 10 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the raw material monomers of the styrene resin.

[0057] The composite resin is preferably a resin in which a polyester resin and a styrene resin are bonded, and more preferably a resin chemically bonded through a bifunctional monomer capable of reacting with both the raw material monomers of the polyester resin and the raw material monomers of the styrene resin.

[0058] The bifunctional monomer preferably has, in the molecule, at least one functional group selected from the group consisting of a hydroxyl group, a carboxyl group, an epoxy group, a primary amino group, and a secondary amino group, preferably a hydroxyl group and / or a carboxyl group, more preferably a carboxyl group, and an ethylenically unsaturated bond. At least one selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic acid, and maleic anhydride is more preferable, and at least one selected from the group consisting of acrylic acid, methacrylic acid, and fumaric acid is even more preferable from the viewpoint of the reactivity of the polycondensation reaction and the addition polymerization reaction. However, when used together with a polymerization inhibitor, a polycarboxylic acid compound having an ethylenically unsaturated bond such as fumaric acid functions as a raw material monomer of the polyester resin. In this case, fumaric acid and the like are not bifunctional monomers but raw material monomers of the polyester resin.

[0059] From the viewpoint of low-temperature fixability, the amount of the bifunctional monomer used is preferably 1 mol or more, more preferably 2 mol or more, per 100 mol of the total alcohol components of the polyester resin, and from the viewpoint of enhancing the dispersibility between the styrene resin and the polyester resin and improving the image density of the toner, it is preferably 30 mol or less, more preferably 20 mol or less, and even more preferably 10 mol or less. Also, from the viewpoint of low-temperature fixability, the amount of the bifunctional monomer used is preferably 1 part by mass or more, more preferably 2 parts by mass or more, per 100 parts by mass of the total raw material monomers of the styrene resin, and from the viewpoint of enhancing the dispersibility between the styrene resin and the polyester resin and improving the image density of the toner, it is preferably 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less. Here, the polymerization initiator is included in the total of the raw material monomers of the styrene resin.

[0060] Specifically, the composite resin is preferably produced by the following method. When using a bifunctional monomer, from the viewpoint of improving the image density and low-temperature fixability of the toner, the bifunctional monomer is preferably used in the addition polymerization reaction together with the raw material monomers of the styrene resin.

[0061] (i) A method in which after step (A) of the polycondensation reaction with the raw material monomers of the polyester resin, step (B) of the addition polymerization reaction with the raw material monomers of the styrene resin and the both-reactive monomers is carried out In this method, step (A) is carried out under reaction temperature conditions suitable for the polycondensation reaction, the reaction temperature is lowered, and step (B) is carried out under temperature conditions suitable for the addition polymerization reaction. The raw material monomers of the styrene resin and the both-reactive monomers are preferably added into the reaction system at a temperature suitable for the addition polymerization reaction. The both-reactive monomers carry out the addition polymerization reaction and also react with the polyester resin After step (B), the reaction temperature is raised again, and if necessary, raw material monomers of a polyester resin having a trivalent or higher valence that serves as a crosslinking agent are added to the polymerization system, and the polycondensation reaction in step (A) and the reaction with the both-reactive monomers can be further advanced

[0062] (ii) A method in which after step (B) of the addition polymerization reaction with the raw material monomers of the styrene resin and the both-reactive monomers, step (A) of the polycondensation reaction with the raw material monomers of the polyester resin is carried out In this method, step (B) is carried out under reaction temperature conditions suitable for the addition polymerization reaction, the reaction temperature is raised, and the polycondensation reaction of step (A) is carried out under temperature conditions suitable for the polycondensation reaction. The both-reactive monomers are also involved in the polycondensation reaction together with the addition polymerization reaction The raw material monomers of the polyester resin may be present in the reaction system during the addition polymerization reaction, or may be added to the reaction system under temperature conditions suitable for the polycondensation reaction. In the former case, the progress of the polycondensation reaction can be adjusted by adding an esterification catalyst at a temperature suitable for the polycondensation reaction

[0063] (iii) A method in which the reaction is carried out under conditions where step (A) of the polycondensation reaction with the raw material monomers of the polyester resin and step (B) of the addition polymerization reaction with the raw material monomers of the styrene resin and the both-reactive monomers proceed in parallel In this method, step (A) and step (B) are carried out in parallel under reaction temperature conditions suitable for the addition polymerization reaction, the reaction temperature is raised, and under temperature conditions suitable for the polycondensation reaction, if necessary, a raw material monomer of a polyester resin having a trivalent or higher valency serving as a crosslinking agent is added to the polymerization system, and the polycondensation reaction in step (A) is further carried out, which is preferable. At that time, under temperature conditions suitable for the polycondensation reaction, a polymerization inhibitor can also be added to proceed only the polycondensation reaction. Both reactive monomers are involved in the polycondensation reaction as well as the addition polymerization reaction.

[0064] In the method of (i) above, instead of step (A) of carrying out the polycondensation reaction, a pre-polymerized polycondensation resin may be used. In the method of (iii) above, when the reaction is carried out under conditions where step (A) and step (B) proceed in parallel, a mixture containing a raw material monomer of a styrene resin may be dropped into a mixture containing a raw material monomer of a polyester resin and reacted.

[0065] The methods of (i) to (iii) above are preferably carried out in the same container.

[0066] The mass ratio (polyester resin / styrene resin) of the polyester resin and the styrene resin in the composite resin is preferably 98 / 2 or less, more preferably 95 / 5 or less, still more preferably 90 / 10 or less from the viewpoint of image density, and preferably 60 / 40 or more, more preferably 70 / 30 or more, still more preferably 75 / 25 or more from the viewpoint of low-temperature fixability. In the above calculation, the mass of the polyester resin is the amount obtained by excluding the amount of reaction water (calculated value) dehydrated by the polycondensation reaction from the mass of the raw material monomer of the polyester resin used, and the amount of both reactive monomers is included in the amount of the raw material monomer of the polyester resin. Further, the amount of the styrene resin is the total amount of the raw material monomer of the styrene resin and the polymerization initiator.

[0067] The softening point of the amorphous resin A is preferably 90°C or higher, more preferably 100°C or higher from the viewpoint of storage stability, and preferably 150°C or lower, more preferably 140°C or lower from the viewpoints of low-temperature fixability and image density.

[0068] Note that the amorphous resin A may be composed of resins having different softening points from the viewpoints of low-temperature fixability and fixing width. The difference in the softening points of the two resins is preferably 10 °C or more, more preferably 12 °C or more, and preferably 60 °C or less, more preferably 30 °C or less, still more preferably 20 °C or less.

[0069] The softening point of the amorphous resin with a higher softening point (resin AH) is preferably 100 °C or more, more preferably 110 °C or more, still more preferably 120 °C or more from the viewpoint of fixing width, and preferably 180 °C or less, more preferably 160 °C or less, still more preferably 140 °C or less from the viewpoint of low-temperature fixability.

[0070] Also, the softening point of the amorphous resin with a lower softening point (resin AL) is preferably 70 °C or more, more preferably 90 °C or more, still more preferably 100 °C or more from the viewpoint of storage stability, and preferably 130 °C or less, more preferably 125 °C or less, still more preferably 120 °C or less from the viewpoint of low-temperature fixability.

[0071] The mass ratio of resin AH to resin AL (resin AH / resin AL) is preferably 10 / 90 or more, more preferably 20 / 80 or more, still more preferably 30 / 70 or more, and preferably 90 / 10 or less, more preferably 80 / 20 or less, still more preferably 70 / 30 or less.

[0072] The glass transition temperature of the amorphous resin A is preferably 40 °C or more, more preferably 50 °C or more from the viewpoint of storage stability, and preferably 80 °C or less, more preferably 70 °C or less, still more preferably 65 °C or less from the viewpoint of low-temperature fixability.

[0073] The acid value of the amorphous resin A is preferably 1 mgKOH / g or more, more preferably 3 mgKOH / g or more from the viewpoint of low-temperature fixability, and preferably 20 mgKOH / g or less, more preferably 15 mgKOH / g or less from the viewpoint of image density.

[0074] The number average molecular weight of the amorphous resin A is preferably 1,000 or more, more preferably 1,500 or more, still more preferably 2,000 or more from the viewpoint of image density, and is preferably 6,000 or less, more preferably 5,000 or less, still more preferably 4,000 or less from the viewpoint of low-temperature fixability.

[0075] The weight average molecular weight of the amorphous resin A is preferably 5,000 or more, more preferably 6,000 or more, still more preferably 8,000 or more from the viewpoint of image density, and is preferably 500,000 or less, more preferably 200,000 or less, still more preferably 150,000 or less from the viewpoint of low-temperature fixability.

[0076] The mass ratio of the crystalline polyester resin C to the amorphous resin A (crystalline polyester resin C / amorphous resin A) is preferably 1 / 99 or more, more preferably 3 / 97 or more, still more preferably 5 / 95 or more from the viewpoint of low-temperature fixability, and is preferably 40 / 60 or less, more preferably 35 / 65 or less, still more preferably 30 / 70 or less from the viewpoint of image density.

[0077] In the toner, the crystalline polyester resin C and the amorphous resin A are contained as a binder resin.

[0078] Examples of other binder resins include vinyl resins such as styrene acrylic resins, epoxy resins, polycarbonates, polyurethanes, and composite resins containing two or more of these resins.

[0079] The total content of the crystalline polyester resin C and the amorphous resin A is preferably 70% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 100% by mass in the binder resin.

[0080] Also, the content of the binder resin is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more in the toner, and is preferably less than 100% by mass, more preferably 98% by mass or less, still more preferably 95% by mass or less.

[0081] As the colorant, dyes, pigments, magnetic materials, etc. that are used as colorants for toners can be used. For example, carbon black, phthalocyanine blue, permanent brown FG, brilliant fast scarlet, pigment red 122, pigment green B, rhodamine - B base, solvent red 49, solvent red 146, solvent blue 35, quinacridone, carmine 6B, isoindoline, disazo yellow, etc. can be mentioned. In the present invention, the toner may be either a black toner or a color toner.

[0082] From the viewpoint of improving the image density and low - temperature fixability of the toner, the content of the colorant is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and is preferably 40 parts by mass or less, more preferably 20 parts by mass or less, still more preferably 10 parts by mass or less with respect to 100 parts by mass of the binder resin.

[0083] In addition to the binder resin and the colorant, the toner may contain additives such as a release agent, a charge control agent, magnetic powder, a fluidity improver, a conductivity adjuster, a reinforcing filler such as a fibrous substance, an antioxidant, and a cleaning property improver.

[0084] Examples of the release agent include hydrocarbon waxes such as polypropylene wax, polyethylene wax, polypropylene - polyethylene copolymer wax, microcrystalline wax, paraffin wax, Fischer - Tropsch wax and their oxides; ester waxes such as carnauba wax, montan wax and their deacidified waxes, fatty acid ester waxes; fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts, etc. These can be used alone or in combination of two or more.

[0085] From the perspective of storage stability, the melting point of the release agent is preferably 60°C or higher, more preferably 70°C or higher, and from the perspective of low-temperature fixability, it is preferably 160°C or lower, more preferably 140°C or lower, still more preferably 120°C or lower, and even more preferably 110°C or lower.

[0086] From the perspectives of the low-temperature fixability and image density of the toner and the dispersibility in the binder resin, the content of the release agent is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, still 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, still more preferably 7 parts by mass or less, based on 100 parts by mass of the binder resin.

[0087] The charge control agent is not particularly limited, and may contain either a positive-charge control agent or a negative-charge control agent.

[0088] Examples of the positive-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" (manufactured by Orient Chemical Industries, Ltd.); triphenylmethane dyes containing a tertiary amine in the side chain; quaternary ammonium salt compounds such as "Bontron P-51" (manufactured by Orient Chemical Industries, Ltd.), cetyltrimethylammonium bromide, "COPY CHARGE PX VP435" (manufactured by Clariant); polyamine resins such as "AFP-B" (manufactured by Orient Chemical Industries, Ltd.); imidazole derivatives such as "PLZ-2001", "PLZ-8001" (manufactured by Shikoku Kasei Kogyo Co., Ltd.); styrene-acrylic resins such as "FCA-701PT", "FCA-201-PS" (manufactured by Fujikura Kasei Co., Ltd.).

[0089] In addition, examples of the negatively charged charge control agent include metal-containing azo dyes such as "Vari Fast Black 3804", "Bontron S-31", "Bontron S-32", "Bontron S-34", "Bontron S-36" (manufactured by Orient Chemical Industries, Ltd.), "Izen Spiron Black TRH", "T-77" (manufactured by Hodogaya Chemical Co., Ltd.), etc.; metal compounds of benzoic acid compounds such as "LR-147", "LR-297" (manufactured by Nippon Carlit Co., Ltd.), etc.; metal compounds of salicylic acid compounds such as "Bontron E-81", "Bontron E-84", "Bontron E-88", "Bontron E-304" (manufactured by Orient Chemical Industries, Ltd.), "TN-105" (manufactured by Hodogaya Chemical Co., Ltd.), etc.; copper phthalocyanine dyes; quaternary ammonium salts such as "COPY CHARGE NX VP434" (manufactured by Clariant), nitroimidazole derivatives, etc.; and organometallic compounds, etc.

[0090] From the viewpoint of the charging stability of the toner, the content of the charge control agent is preferably 0.01 part by mass or more, more preferably 0.2 part by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 3 parts by mass or less, and still more preferably 2 parts by mass or less with respect to 100 parts by mass of the binder resin.

[0091] In the present invention, a mixture containing the crystalline polyester resin C, the amorphous resin A, and the colorant, and further, if necessary, additives such as a release agent and a charge control agent is subjected to a step of melt-kneading using an open-roll type twin-screw kneader.

[0092] The mixture to be subjected to melt-kneading may be kneaded at once or divided and kneaded, but it is preferable to mix it in a mixer such as a Henschel mixer or a ball mill in advance and then supply it to an open-roll type twin-screw kneader.

[0093] An open roll type twin-screw kneader is a kneader equipped with two rolls, and the melting and kneading section is not sealed but open, enabling easy heat dissipation of the kneading heat generated during melting and kneading. The open roll type twin-screw kneader used in the present invention is provided with a plurality of raw material supply ports and kneaded product discharge ports provided along the axial direction of the rolls, and from the perspective of production efficiency, it is preferably a continuous open roll type twin-screw kneader.

[0094] The open roll type twin-screw kneader used in the present invention is a kneader equipped with two rolls having different peripheral speeds, that is, two rolls, a high-speed rotating roll with a high peripheral speed and a low-speed rotating roll with a low peripheral speed. In the present invention, from the perspective of improving the dispersibility of the crystalline polyester resin, it is preferable that the high-speed rotating roll is a heating roll and the low-speed rotating roll is a cooling roll.

[0095] The temperature of the roll can be adjusted, for example, by the temperature of the heat medium passed through the inside of the roll, and each roll may have the inside of the roll divided into two or more parts and pass heat media with different temperatures.

[0096] From the perspective of improving the dispersibility of the crystalline polyester resin, the temperature on the kneaded product discharge side of the high-speed rotating roll is -20°C or higher, preferably -15°C or higher, more preferably -10°C or higher, still more preferably -5°C or higher, and still more preferably at or above the melting point of the crystalline polyester resin C, and is +15°C or lower, preferably +13°C or lower, more preferably +12°C or lower, of the melting point of the crystalline polyester resin C.

[0097] On the other hand, from the perspective of melting the crystalline polyester resin, the temperature on the raw material input side of the high-speed rotating roll is preferably +5°C or higher, more preferably +15°C or higher, still more preferably +25°C or higher, of the melting point of the crystalline polyester resin C, and is preferably +65°C or lower, more preferably +60°C or lower, still more preferably +55°C or lower, and still more preferably +45°C or lower, of the melting point of the crystalline polyester resin C.

[0098] The temperature on the discharge side of the kneaded product of the low-speed roll is preferably 25°C or higher, more preferably 30°C or higher, and preferably 80°C or lower, more preferably 50°C or lower, from the viewpoint of improving the dispersibility of the crystalline polyester resin.

[0099] The temperature on the raw material input side of the low-speed roll is preferably 25°C or higher, more preferably 40°C or higher, and preferably 80°C or lower, more preferably 70°C or lower, from the viewpoint of reducing the mechanical force during melt kneading and suppressing heat generation.

[0100] It is preferable that the temperature of both the high-speed roll and the low-speed roll is higher on the raw material input side than on the discharge side of the kneaded product. The temperature difference between the raw material input side and the discharge side of the kneaded product of the high-speed roll is preferably 5°C or higher, more preferably 20°C or higher, and preferably 60°C or lower, more preferably 50°C or lower, still more preferably 35°C or lower, from the viewpoints of preventing the kneaded product from detaching from the roll and reducing the mechanical force and suppressing heat generation during melt kneading. The temperature difference between the raw material input side and the discharge side of the kneaded product of the low-speed roll is preferably 5°C or higher and preferably 50°C or lower, from the viewpoints of improving the dispersibility of the crystalline polyester resin and reducing the mechanical force and suppressing heat generation during melt kneading.

[0101] The temperature on the raw material input side of the high-speed roll and the low-speed roll refers to the set temperature at the end of the raw material input side, and the temperature on the discharge side of the kneaded product refers to the set temperature at the end of the discharge side of the kneaded product, respectively.

[0102] From the perspective of improving the dispersibility of the crystalline polyester resin and reducing the mechanical force during melt-kneading to suppress heat generation, the peripheral speed of the high-speed roll is preferably 2 m / min or more, more preferably 10 m / min or more, still more preferably 25 m / min or more, and preferably 100 m / min or less, more preferably 75 m / min or less, still more preferably 50 m / min or less. From the same perspective, the peripheral speed of the low-speed roll is preferably 1 m / min or more, more preferably 5 m / min or more, still more preferably 15 m / min or more, and preferably 90 m / min or less, more preferably 60 m / min or less, still more preferably 30 m / min or less. Also, the ratio of the peripheral speeds of the two rolls (low-speed roll / high-speed roll) is preferably 1 / 10 or more, more preferably 3 / 10 or more, and preferably 9.9 / 10 or less, more preferably 8 / 10 or less.

[0103] Also, there are no particular limitations on the structure, size, material, etc. of each roll. The roll surface has grooves used for kneading, and examples of this shape include linear, spiral, wavy, concave-convex, etc.

[0104] After melt-kneading, it is preferable to appropriately cool the kneaded product until it reaches a hardness that can be pulverized, and if necessary, perform a pulverization process and a classification process to obtain toner particles. Here, cooling means cooling the kneaded product to 0°C or more and 50°C or less, or cooling it to below the glass transition temperature of the binder resin in the kneaded product.

[0105] In the pulverization of the kneaded product, the kneaded product may be pulverized at once to the desired particle size or pulverized step by step, but from the perspective of efficient and more uniform pulverization, it is preferable to perform it in two stages: coarse pulverization and fine pulverization.

[0106] Examples of the pulverizer used for coarse pulverization include hammer mills, cutter mills, atomizers, rotor plexers, etc.

[0107] In coarse pulverization, it is preferable to pulverize until the maximum diameter becomes 3 mm or less. For example, the pulverized material with a maximum diameter of 3 mm or less can be obtained by appropriately coarsely pulverizing the kneaded material until the particle size becomes about 0.05 mm or more and 3 mm or less, and then passing it through a sieve with an aperture of 3 mm.

[0108] Examples of the pulverizer used for fine pulverization include jet mills such as fluidized bed jet mills and impact plate jet mills, and mechanical mills.

[0109] The degree of fine pulverization is preferably adjusted as appropriate according to the particle size of the target toner particles.

[0110] Examples of the classifier used for classification include air classifiers, inertial classifiers, and sieve classifiers. During the classification process, the pulverized material that was not sufficiently pulverized and removed may be returned to the pulverization process, or the pulverization process and the classification process may be repeated as necessary.

[0111] In the present invention, it is preferable that the obtained toner particles further have an external addition step of mixing with an external additive.

[0112] Examples of the external additive include inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide, and zinc oxide, and organic fine particles such as melamine resin fine particles and polytetrafluoroethylene resin fine particles. Two or more kinds may be used in combination. Among these, silica is preferable, and more preferably hydrophobic silica that has been hydrophobically treated from the viewpoint of the fluidity of the toner.

[0113] Examples of the hydrophobizing agent for hydrophobizing the surface of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), cyclic silazane, silicone oil, aminosilane, octyltriethoxysilane (OTES), and methyltriethoxysilane.

[0114] The average particle diameter of the external additive is preferably 5 nm or more, more preferably 10 nm or more, still more preferably 15 nm or more, and preferably 250 nm or less, more preferably 200 nm or less, still more preferably 90 nm or less, from the viewpoints of the chargeability and fluidity of the toner.

[0115] The content of the external additive is preferably 0.05 part by mass or more, more preferably 0.1 part by mass or more, still more preferably 0.3 part by mass or more, and preferably 5 parts by mass or less, more preferably 3 parts by mass or less, with respect to 100 parts by mass of the toner particles before being treated with the external additive, from the viewpoints of the chargeability and fluidity of the toner.

[0116] The volume median diameter (D 50 ) of the toner obtained by the method of the present invention is preferably 3 μm or more, more preferably 4 μm or more, and preferably 15 μm or less, more preferably 10 μm or less. In the present specification, the volume median diameter (D 50 ) means the particle diameter at which the cumulative volume frequency calculated by the volume fraction becomes 50% when calculated from the smaller particle diameter. Further, when the toner is treated with an external additive, the volume median diameter of the toner particles before being treated with the external additive is defined as the volume median diameter of the toner.

[0117] The toner obtained by the method of the present invention can be used as a one-component developer toner as it is, or as a two-component developer toner mixed with a carrier, in an image forming apparatus using a one-component development system or a two-component development system, respectively.

Examples

[0118] Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited by these examples. Physical properties such as those of the resin can be measured by the following methods.

[0119] 〔Softening point of resin〕 Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), while heating a 1 g sample at a heating rate of 6 °C / min, apply a load of 1.96 MPa to the plunger and extrude it from a nozzle with a diameter of 1 mm and a length of 1 mm. Plot the plunger descent amount of the flow tester against the temperature, and take the temperature at which half of the sample has flowed out as the softening point.

[0120] 〔Maximum peak temperature of resin endotherm〕 Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), weigh 0.01 - 0.02 g of the sample into an aluminum pan, cool it from room temperature (25 °C) to 0 °C at a cooling rate of 10 °C / min, and maintain it at 0 °C for 1 minute. Then, measure it at a heating rate of 10 °C / min. Among the observed endothermic peaks, take the temperature of the peak with the largest peak area as the maximum peak temperature of the endotherm.

[0121] 〔Glass transition temperature of amorphous resin〕 Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan), weigh 0.01 - 0.02 g of the sample into an aluminum pan, heat it up to 200 °C, and then cool it from that temperature to 0 °C at a cooling rate of 10 °C / min. Next, heat the sample at a heating rate of 10 °C / min and measure the endothermic peak. Take the temperature at the intersection of the extension of the baseline below the maximum peak temperature of the endotherm and the tangent line indicating the maximum slope from the rising part of the peak to the peak apex as the glass transition temperature.

[0122] 〔Acid value of resin〕 Measure based on the method of JIS K 0070:1992. However, change the measurement solvent only from the mixed solvent of ethanol and ether specified in JIS K 0070 to a mixed solvent of acetone and toluene (acetone:toluene = 1:1 (volume ratio)) for amorphous resins, and a mixed solvent of chloroform and dimethylformamide (chloroform:dimethylformamide = 7:3 (volume ratio)) for crystalline resins, respectively.

[0123] 〔Number average molecular weight and weight average molecular weight of resin〕 The number average molecular weight and weight average molecular weight are determined by gel permeation chromatography (GPC) method according to the following method. (1) Preparation of sample solution The resin was dissolved in tetrahydrofuran so that the concentration became 0.5 g / 100 mL. Then, this solution was filtered using a fluororesin filter with a pore size of 2 μm (manufactured by Sumitomo Electric Industries, Ltd., trade name: FP-200) to remove insoluble components, and used as a sample solution. (2) Molecular weight measurement Using the following measuring device and analytical column, tetrahydrofuran was used as an eluent and flowed at a flow rate of 1 mL per minute to stabilize the column in a constant temperature bath at 40°C. 100 μL of the sample solution was injected therein for measurement. The molecular weight of the sample was calculated based on a calibration curve prepared in advance. For the calibration curve at this time, several monodisperse polystyrenes with known molecular weights (manufactured by Tosoh Corporation; 2.63×10 3 , 2.06×10 4 , 1.02×10 5 , manufactured by GL Sciences Inc.; 2.10×10 3 , 7.00×10 3 , 5.04×10 4 ) were used as standard samples. Measuring device: CO-8010 (trade name, manufactured by Tosoh Corporation) Analytical column: GMH XL +G3000H XL (Both are trade names, manufactured by Tosoh Corporation)

[0124] [Melting point of release agent] Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), 0.02 g of the sample was weighed into an aluminum pan, heated up to 200°C, and then cooled from 200°C to 0°C at a cooling rate of 10°C / min. Next, the sample was heated at a heating rate of 10°C / min, and the heat quantity was measured. The maximum peak temperature of endotherm was taken as the melting point.

[0125] [Average particle diameter of external additive] The average particle diameter refers to the number-average particle diameter. The particle diameters (average value of the major axis and minor axis) of 500 particles are measured from a scanning electron microscope (SEM) photograph, and their number-average value is used.

[0126] 〔Volume median particle diameter (D 50 ) of toner〕 · Measuring instrument: "Coulter Multisizer (registered trademark) III" (manufactured by Beckman Coulter, Inc.) · Aperture diameter: 50 μm · Analysis software: "Multisizer (registered trademark) III version 3.51" (manufactured by Beckman Coulter, Inc.) · Electrolyte: "Isoton (registered trademark) II" (manufactured by Beckman Coulter, Inc.) · Dispersion liquid: Prepared by dissolving polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" (manufactured by Kao Corporation, HLB (Griffin) = 13.6) in the electrolyte to a concentration of 5% by mass. · Dispersion conditions: Add 10 mg of the measurement sample to 5 mL of the above dispersion liquid, disperse it for 1 minute with an ultrasonic disperser (machine name: US-1 manufactured by SND Co., Ltd., output: 80 W), then add 25 mL of the electrolyte, and further disperse it for 1 minute with the ultrasonic disperser to prepare a sample dispersion liquid. · Measurement conditions: After adjusting the concentration of the sample dispersion liquid added to 100 mL of the electrolyte so that the particle diameters of 30,000 particles can be measured in 20 seconds, measure 30,000 particles, and determine the volume median particle diameter (D 50 ) from the particle size distribution.

[0127] Production Example 1 of Alkenyl Succinic Anhydride (1) Using propylene tetramer (manufactured by Nippon Oil Corporation, trade name: "Light Tetramer"), it was fractionated under heating conditions of 183 to 208 °C to obtain an alkylene compound (a). The obtained alkylene compound (a) had 40 peaks in the gas chromatography-mass spectrometry described later. The distribution of the alkylene compound was measured according to the analysis by gas chromatography-mass spectrometry of alkylene compound A in JP-A-2014-013384, and C 9 H 18 : 0.5% by mass, C10 H 20 : 4 mass%, C 11 H 22 : 20 mass%, C 12 H 24 : 66 mass%, C 13 H 26 : 9 mass%, C 14 H 28 : 0.5 mass% (the number of peaks corresponding to an alkylene compound having 9 to 14 carbon atoms was 6).

[0128] (2) 542.4 g of alkylene compound (a), 157.2 g of maleic anhydride, 0.4 g of antioxidant "Chelex - O" (manufactured by SC Organic Chemical Co., Ltd., Triisooctyl phosphite), and 0.1 g of butylhydroquinone as a polymerization inhibitor were charged into a 1 - L autoclave manufactured by Nitto Koki Co., Ltd. The pressurized nitrogen substitution (0.2 MPaG) was repeated 3 times. After starting stirring at 60°C, the temperature was raised to 230°C over 1 hour and the reaction was carried out for 6 hours. The pressure at the time of reaching the reaction temperature was 0.3 MPaG. After the reaction was completed, it was cooled to 80°C, returned to normal pressure (101.3 kPa), and transferred to a 1 - liter four - necked flask. The temperature was raised to 180°C with stirring, and the remaining alkylene compound was distilled off at 1.3 kPa over 1 hour. Subsequently, after cooling to room temperature (25°C) and returning to normal pressure (101.3 kPa), 406.1 g of the target alkenyl succinic anhydride A was obtained. The average molecular weight of alkenyl succinic anhydride A determined from the acid value was 268.

[0129] Resin Production Example 1 The alcohol component, carboxylic acid component, and polymerization inhibitor shown in Table 1 were placed in a 5 - liter four - necked flask equipped with a thermometer, a stainless - steel stirring rod, a reflux condenser, and a nitrogen inlet tube, and the temperature was raised to 200°C over 8 hours in a mantle heater under a nitrogen atmosphere. Then, an esterification catalyst was added, and the reaction was carried out at 8.0 kPa until the softening point shown in Table 1 was reached, and crystalline polyester resins (Resins C1 - C4) were obtained. The physical properties are shown in Table 1.

[0130] Resin Production Example 2 The alcohol component and carboxylic acid component shown in Table 1 were placed in a 5-liter four-necked flask equipped with a thermometer, a stainless steel stirring rod, a reflux condenser, and a nitrogen inlet tube, and heated in a mantle heater under a nitrogen atmosphere to 200°C over 8 hours. Thereafter, an esterification catalyst was added, and the reaction was carried out at 8.0 kPa until the softening point shown in Table 1 was reached, to obtain a crystalline polyester resin (Resins C5 - C8). The physical properties are shown in Table 1.

[0131]

Table 1

[0132] Resin Production Example 3 The raw material monomers, esterification catalyst, and esterification co-catalyst of the polyester resin other than trimellitic anhydride shown in Table 2 were placed in a 5-liter four-necked flask equipped with a nitrogen inlet tube, a stirrer, and a thermocouple. After heating to 235°C under a nitrogen atmosphere, polycondensation was carried out at 235°C for 6 hours. Thereafter, the temperature was lowered to 210°C, trimellitic anhydride was added, and after reacting at 210°C for 1 hour, the reaction was further carried out at 210°C under a reduced pressure of 10 kPa until the softening point described in Table 2 was reached, to obtain an amorphous polyester resin (Resin AH1). The physical properties are shown in Table 2.

[0133] Resin Production Example 4 The raw material monomers, esterification catalyst, and esterification co-catalyst of the polyester resin other than trimellitic anhydride and fumaric acid shown in Table 2 were placed in a 5-liter four-necked flask equipped with a nitrogen inlet tube, a stirrer, and a thermocouple. After heating to 235°C under a nitrogen atmosphere, polycondensation was carried out at 235°C for 6 hours. Then, the temperature was lowered to 160°C, and a mixture of both reactive monomers, the raw material monomers of the styrene resin, and a polymerization initiator was added dropwise over 1 hour using a dropping funnel. After the dropwise addition, while maintaining the temperature at 160°C, the addition polymerization reaction was aged for 1 hour, then raised to 200°C, and the pressure was reduced to 10 kPa for 1 hour. After releasing the pressure, the temperature was lowered to 180°C, trimellitic anhydride, fumaric acid, and a polymerization inhibitor shown in Table 2 were added, and after holding at 180°C for 1 hour, the temperature was raised from 180°C to 210°C at 10°C / h and reacted at 210°C for 1 hour. Further, the reaction was carried out under a reduced pressure of 10 kPa at 210°C until the softening point shown in Table 2 was reached to obtain an amorphous composite resin (resin AH2). The physical properties are shown in Table 2.

[0134] Resin Production Example 5 The raw material monomers, esterification catalyst, and esterification co-catalyst of the polyester resin other than trimellitic anhydride and fumaric acid shown in Table 2 were placed in a 5-liter four-necked flask equipped with a nitrogen inlet tube, a stirrer, and a thermocouple. After heating to 235°C under a nitrogen atmosphere, polycondensation was carried out at 235°C for 6 hours. Then, the temperature was lowered to 180°C, trimellitic anhydride, fumaric acid, and a polymerization inhibitor were added, and after holding at 180°C for 1 hour, the temperature was raised from 180°C to 210°C at 10°C / h and reacted at 210°C for 1 hour. Further, the reaction was carried out under a reduced pressure of 10 kPa at 210°C until the softening point shown in Table 2 was reached to obtain an amorphous polyester resin (resin AH3). The physical properties are shown in Table 2.

[0135] Resin Production Example 6 The raw material monomers, esterification catalyst, and esterification co-catalyst of the polyester resin shown in Table 2 were placed in a 5-liter four-necked flask equipped with a nitrogen inlet tube, a stirrer, and a thermocouple. After heating to 235°C under a nitrogen atmosphere, polycondensation was carried out at 235°C for 6 hours. Then, the temperature was lowered to 210°C, and the reaction was carried out under a reduced pressure of 10 kPa until the softening point shown in Table 2 was reached, to obtain an amorphous polyester resin (resins AL1 and AL3). The physical properties are shown in the table.

[0136] Resin Production Example 7 The raw material monomers, esterification catalyst, and esterification co-catalyst of the polyester resin other than fumaric acid shown in Table 2 were placed in a 5-liter four-necked flask equipped with a dehydration tube equipped with a nitrogen inlet tube, a stirrer, and a thermocouple. After heating to 235°C under a nitrogen atmosphere, polycondensation was carried out at 235°C for 6 hours. Then, the temperature was lowered to 160°C, and a mixture of both reactive monomers, the raw material monomers of the styrene resin, and a polymerization initiator was added dropwise over 1 hour using a dropping funnel. After the addition, while maintaining the temperature at 160°C, the addition polymerization reaction was aged for 1 hour, then the temperature was raised to 200°C, and the pressure was reduced to 10 kPa for 1 hour. After releasing the pressure, the temperature was lowered to 180°C, fumaric acid and a polymerization inhibitor shown in Table 2 were added, and after maintaining the temperature at 180°C for 1 hour, the temperature was raised from 180°C to 210°C at 10°C / h, and the reaction was carried out at 210°C for 1 hour. Further, the reaction was carried out under a reduced pressure of 10 kPa at 210°C until the softening point shown in Table 2 was reached, to obtain an amorphous composite resin (resin AL2). The physical properties are shown in Table 2.

[0137]

Table 2

[0138] Examples 1 to 12 and Comparative Examples 1 to 4 100 parts by mass of the binder resin shown in Table 3, 5 parts by mass of the colorant "ECB-301" (manufactured by Dainichi Seika Co., Ltd., phthalocyanine blue (P.B.15:3)), 3 parts by mass of the release agent "Carnuba wax C1" (manufactured by Kato Yoko Co., Ltd., melting point: 83°C), 3 parts by mass of the release agent "HNP-9" (manufactured by Nippon Seiro Co., Ltd., paraffin wax, melting point: 75°C), and 0.5 parts by mass of the charge control agent "Bontron E-304" (manufactured by Orient Chemical Co., Ltd.) were mixed with a Henschel mixer.

[0139] The obtained raw material mixture was fed by a table feeder to a continuous open roll type twin-screw kneader "Neidex" (manufactured by Mitsui Mining Co., Ltd.) for kneading to obtain a kneaded product. The continuous open roll type twin-screw kneader used at this time had a roll outer diameter of 0.14 m and an effective roll length of 0.8 m. The operating conditions were that the rotational speed of the high-speed roll (front roll) was 75 r / min (circumferential speed 33 m / min), the rotational speed of the low-speed roll (rear roll) was 50 r / min (circumferential speed 22 m / min), and the roll gap was 0.1 mm. The temperatures of the heating and cooling media inside the rolls were set to the temperatures shown in Table 3 for the raw material input side (IN) and the kneaded product discharge side (OUT) of the high-speed roll, and the temperature of the raw material input side of the low-speed roll was set to 65°C and the temperature of the kneaded product discharge side was set to 30°C. Also, the supply rate of the raw material mixture was 10 kg / h and the average residence time was about 5 minutes.

[0140] The obtained kneaded product was cooled to 25°C and roughly pulverized by a pulverizer "Rotoplex" (manufactured by Toa Machinery Co., Ltd.) to obtain a roughly pulverized product with a particle size of 2 mm or less using a sieve with an opening of 2 mm. Fine pulverization and upper limit classification (removal of coarse powder) were performed with a counter jet mill "400AFG" (manufactured by Hosokawa Alpine Co., Ltd.). Further, lower limit classification (removal of fine powder) was performed with a classifier "TTSP" (manufactured by Hosokawa Alpine Co., Ltd.) to obtain toner particles with a volume median particle size of 6.5 μm.

[0141] 100 parts by mass of the obtained toner particles, 1.0 part by mass of hydrophobic silica "R972" (manufactured by Nippon Aerosil Co., Ltd., hydrophobizing agent: DMDS, average particle diameter: 16 nm), and 1.0 part by mass of hydrophobic silica "RY-50" (manufactured by Nippon Aerosil Co., Ltd., hydrophobizing agent: silicone oil, average particle diameter: 40 nm) were mixed in a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.) at a rotation speed of 3000 r / min (peripheral speed: 32 m / sec) for 3 minutes to obtain a toner.

[0142] Test Example 1 [Low-temperature fixability of toner] The toner was mounted on a device obtained by improving the fixing device of a copying machine "AR-505" (manufactured by Sharp Corporation) so that fixing outside the device was possible, and a printed matter was obtained in an unfixed state (printing area: 2 cm × 12 cm, adhesion amount: 0.5 mg / cm 2 ). Then, using a fixing machine (fixing speed: 300 mm / sec) adjusted so that the total fixing pressure was 40 kgf, while sequentially increasing the temperature of the fixing roll from 100 °C to 200 °C in 5 °C increments, a fixing test of the unfixed printed matter was performed at each temperature. A 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 matter and passed through a fixing roller set at 30 °C, which was different from the fixing roll of the fixing machine, and then the tape was peeled off. The optical reflection density before and after peeling the tape was measured using a reflection densitometer "RD-915" (manufactured by GretagMacbeth), and the temperature of the fixing roll at which the ratio of the two (after peeling / before attachment × 100) first exceeded 90% was defined as the minimum fixing temperature. The results are shown in Table 3. A lower minimum fixing temperature indicates better low-temperature fixability. Note that "CopyBond SF-70NA" (manufactured by Sharp Corporation, 75 g / m 2 ) was used as the fixing paper.

[0143] Test Example 2 [Image density] The toner was mounted on a device obtained by improving the fixing device of a commercially available printer "Microline (registered trademark) 5400" (manufactured by Oki Data Corporation) to a device that enabled fixing outside the device on high-quality paper "J paper A4 size" (manufactured by Fuji Xerox Co., Ltd.), and the adhesion amount of the toner on the paper was 0.38 to 0.42 mg / cm 2An output solid image was obtained, and a printed matter was obtained in an unfixed state. Next, the temperature of the fixing device was set to 150 °C, and the toner was fixed at a speed of 1.5 seconds per sheet in the vertical A4 direction to obtain a printed matter. The reflection image density of the fixed image portion of the output printed matter was measured using a colorimeter "SpectroEye" (manufactured by GretagMacbeth, light irradiation conditions; standard light source D 50 , observation field of view 2°, density standard DINNB, absolute white standard). The results are shown in Table 3. The larger the value of the reflection image density, the better the image density. The results are shown in Table 3.

[0144]

Table 3

[0145] From the above results, compared with Comparative Examples 1 and 2 in which the temperature on the kneaded material discharge side of the high-speed rotating roll of the open roll type biaxial kneader is outside the predetermined range, and Comparative Examples 3 and 4 using a crystalline polyester resin containing an aliphatic diol having 4 or 6 carbon atoms, it can be seen that the toners of Examples 1 to 12 have good low-temperature fixability and good image density.

Industrial Applicability

[0146] The toner for developing an electrostatic charge image obtained by the method of the present invention is suitably used for developing a latent image formed in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, or the like.

Claims

1. A method for producing a toner for electrostatic charge image development containing a crystalline polyester resin C, an amorphous resin A, and a colorant, wherein the crystalline polyester resin C is a polycondensate of an alcohol component containing an aliphatic diol having 8 to 14 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 4 carbon atoms, and the method includes a step of melt-kneading a mixture containing the crystalline polyester resin C, the amorphous resin A, and the colorant using an open-roll type twin-screw kneader equipped with two rolls having different peripheral speeds, and the temperature on the kneaded product discharge side of the high-speed roll of the open-roll type twin-screw kneader is -20°C or higher and +15°C or lower than the melting point of the crystalline polyester resin C. A method for producing a toner for electrostatic charge image development.

2. The production method according to claim 1, wherein the content of the crystalline polyester resin C is 3% by mass or more and 40% by mass or less in the total amount of the crystalline polyester resin C and the amorphous resin A.

3. The production method according to claim 1 or 2, wherein the aliphatic diol has 8 to 12 carbon atoms.

4. The production method according to any one of claims 1 to 3, wherein the aliphatic dicarboxylic acid compound having 4 carbon atoms is fumaric acid or succinic acid.

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