JP2023088566A - Method for manufacturing toner for electrostatic charge image development - Google Patents

Abstract

To provide a method for manufacturing a toner for electrostatic charge image development which is excellent in low temperature fixability and durability.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 release agent, wherein the crystalline polyester resin C is a polycondensate of an alcohol component containing aliphatic diol having 8 to 10 carbon atoms, and a carboxylic acid component containing an aliphatic dicarboxylic compound having 6 to 10 carbon atoms; the method includes a step of melt-kneading a mixture containing the crystalline polyester resin C, the amorphous resin A and the release 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

The present invention relates to a method for producing an electrostatic charge image developing toner used for developing a latent image formed in an electrophotography method, an electrostatic recording method, an electrostatic printing method, or the like.

As a binder resin for toner, crystalline polyester resin is known to be effective in improving the low-temperature fixability of toner, and its combined use with amorphous resin is being studied.

Patent Document 1 discloses a toner for electrostatic image development containing an amorphous polyester resin A and a crystalline polyester resin C, wherein the amorphous polyester resin A is derived from a polyester resin. and a structural site derived from a modified polyolefin polymer A having a reactive functional group, and the structural site derived from the polyester resin and the structural site derived from the modified polyolefin polymer A are bonded via a covalent bond. Disclosed is a toner for electrostatic charge image development, wherein the amount of the constituent sites linked and derived from the modified polyolefin polymer A is 5% by mass or more and 30% by mass or less with respect to the total amount of the resin components in the toner. ing.

Patent Document 2 describes a backscattered electron image of a cross section of a toner containing a crystalline resin and an amorphous resin, which is dyed with ruthenium tetroxide, and which is photographed using a scanning electron microscope. Reflected electrons of the surface of the toner dyed with ruthenium tetroxide, which is photographed using a scanning electron microscope, and wherein the area dyed with ruthenium tetroxide has a ratio of 50 area % or more and 80 area % or less. A toner is disclosed in which the ratio of the area dyed with the ruthenium tetroxide in the image is 10 area % or more and 40 area % or less.

Patent Document 3 has a crystalline resin and an amorphous resin, has a diffraction peak at least at a position of 2θ = 20 ° to 25 ° in X-ray diffraction measurement, and uses a differential scanning calorimeter (DSC). Then, the glass transition temperature observed in the final heating and cooling step after heating and cooling under the predetermined heating and cooling conditions 1 and the glass transition observed in the final heating and cooling steps after heating and cooling under the predetermined heating and cooling conditions 2 A toner is disclosed which is characterized by a temperature difference of within 10°C.

JP 2020-86459 A JP 2014-77987 A JP 2016-206632 A

However, when a pulverized toner is produced using a crystalline polyester resin, if the crystalline polyester resin is not sufficiently dispersed in the amorphous resin by melt-kneading, the dispersibility will be poor even after the toner is formed by subsequent cooling. Because of insufficient, low-temperature fixability, which is a characteristic of the crystalline polyester resin, cannot be sufficiently exhibited, and durability is also inferior, probably because the crystalline polyester resin with reduced dispersibility prevents the release agent from dispersing. .

TECHNICAL FIELD The present invention relates to a method for producing a toner for electrostatic charge image development which is excellent in low-temperature fixability and durability.

The present invention is a method for producing a toner for electrostatic charge image development containing a crystalline polyester resin C, an amorphous resin A, and a releasing agent, wherein the crystalline polyester resin C has 8 to 10 carbon atoms. It is a polycondensation product of an alcohol component containing an aliphatic diol and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 6 to 10 carbon atoms, crystalline polyester resin C, amorphous resin A, and A step of melt-kneading a mixture containing a template by using an open-roll twin-screw kneader equipped with two rolls having different peripheral speeds, and kneading the high-rotation rolls of the open-roll-type twin-screw kneader. The present invention relates to a method for producing a toner for developing an electrostatic charge image, wherein the temperature on the substance discharge side is -20°C or more and +15°C or less of the melting point of the crystalline polyester resin C.

The electrostatic charge image developing toner obtained by the method of the present invention exhibits excellent effects in improving low-temperature fixability and durability.

The present invention relates to polycondensation of raw material monomers in which the crystalline polyester resin contains a specific aliphatic monomer when producing a toner for electrostatic charge image development containing a crystalline polyester resin, an amorphous resin, and a releasing agent. It is characterized by the use of an open-roll type twin-screw kneader in which the high-rotation rolls are adjusted to a predetermined temperature in the melt-kneading process. The reason why the toner for developing an electrostatic charge image obtained by the method of the present invention is excellent in low-temperature fixability and durability is not clear, but is presumed as follows.

In the present invention, the dispersibility of the crystalline polyester resin in the amorphous resin is improved by using an open-roll type twin-screw kneader with high kneading strength and easy temperature control. 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-rotation rolls is too low, part of the crystalline polyester resin may crystallize during kneading. , the dispersibility in the amorphous resin decreases. On the other hand, if the temperature on the kneaded product discharge side of the high-rotation roll is too high, the dispersibility in the amorphous resin decreases, probably because the viscosity of the crystalline polyester resin decreases. It is not reflected in the improvement of sexuality. Furthermore, the durability is also lowered, probably because the crystalline polyester resin with lowered dispersibility prevents the release agent from dispersing.
In contrast, in the present invention, the temperature of 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, the crystalline polyester resin contains an aliphatic diol having 8 to 10 carbon atoms as an alcohol component, and an aliphatic dicarboxylic acid compound having 6 to 10 carbon atoms as a carboxylic acid component, thereby improving hydrophobicity. There are crystalline polyester resins that have increased polydispersity and improved dispersibility in amorphous resins. As a result, the dispersibility of the release agent, which is also hydrophobic, is improved, and the toner having excellent low-temperature fixability and durability is obtained.

In the present invention, the crystalline polyester resin C is polycondensation of an alcohol component containing an aliphatic diol having 8 to 10 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 6 to 10 carbon atoms. is a thing

The crystallinity of the resin is represented by the ratio of the softening point to the maximum endothermic peak temperature measured by a differential scanning calorimeter, that is, the crystallinity index defined by the value of [softening point/maximum endothermic peak temperature]. The crystalline resin is a resin having a crystallinity index of 0.6 or more, preferably 0.7 or more, more preferably 0.9 or more, and 1.4 or less, preferably 1.2 or less, more preferably 1.1 or less.
On the other hand, the amorphous resin is a resin having a crystallinity index of greater than 1.4, preferably greater than 1.5, and more preferably greater than 1.6, or less than 0.6 when no endothermic peak is observed. , preferably 0.5 or less.
The crystallinity of the resin can be adjusted by the type and ratio of raw material monomers, production conditions (eg, reaction temperature, reaction time, cooling rate), and the like. The maximum endothermic peak temperature refers to the temperature of the peak with the maximum peak area among the observed endothermic peaks. In a crystalline resin, the maximum endothermic peak temperature is defined as the melting point.

Examples of aliphatic diols having 8 to 10 carbon atoms include 1,8-octanediol, 1,9-nonanediol, and 1,10-decanediol.

The content of the aliphatic diol having 8 to 10 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, More preferably, it is 100 mol %.

Alcohol components other than aliphatic diols having 8 to 10 carbon atoms include 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexane Diols, aliphatic diols with 7 or less carbon atoms such as 1,7-heptanediol, aliphatic diols with 11 or more carbon atoms, aromatic diols such as alkylene oxide adducts of bisphenol A, bisphenol A, hydrogenated bisphenol A, sorbitol , pentaerythritol, glycerin, trimethylolpropane, and other trivalent or higher alcohols.

Aliphatic dicarboxylic acid compounds with 6 to 10 carbon atoms include adipic acid (6 carbon atoms), suberic acid (8 carbon atoms), azelaic acid (9 carbon atoms), sebacic acid (10 carbon atoms), ), anhydrides of these acids, alkyl esters of these acids having 1 to 3 carbon atoms, and the like. When the aliphatic dicarboxylic acid-based compound is an alkyl ester, the number of carbon atoms in the alkyl group is not included in the above number of carbon atoms.

The content of the aliphatic dicarboxylic acid compound having 6 to 10 carbon atoms 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, in the carboxylic acid component. mol % or more, more preferably 100 mol %.

Carboxylic acid components other than aliphatic dicarboxylic acid compounds having 6 to 10 carbon atoms include aliphatic dicarboxylic acid compounds having 5 or less carbon atoms or 11 or more carbon atoms, aromatic dicarboxylic acid compounds, and trivalent or higher carboxylic acid compounds. compounds and the like.

The alcohol component may contain a monohydric alcohol, and the carboxylic acid component may contain a monovalent carboxylic acid-based compound, as appropriate.

The equivalent ratio of the carboxy 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 durability, and from the viewpoint of low temperature fixability. Therefore, it is preferably 1.2 or less, more preferably 1.1 or less.

The crystalline polyester resin C is prepared, for example, by mixing an alcohol component and a carboxylic acid component in an inert gas atmosphere, preferably in the presence of an esterification catalyst, and optionally in the presence of an esterification co-catalyst, a polymerization inhibitor, or the like. , preferably at a temperature of 120°C or higher and 230°C or lower.

Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and tin(II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropylate bistriethanolamine. The amount of the esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 1.5 parts by mass or less, or more, relative to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component. It is preferably 1 part by mass or less. Gallic acid etc. are mentioned as an esterification co-catalyst. The amount of the esterification promoter 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, with respect to 100 parts by mass as the total amount of the alcohol component and the carboxylic acid component. More preferably, it is 0.1 part by mass or less. Polymerization inhibitors include t-butylcatechol and the like. The amount of the 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, or more, relative to 100 parts by mass of the total amount of the alcohol component and the carboxylic acid component It is preferably 0.1 part by mass or less.

In addition, in the present invention, the polyester resin may be a polyester resin that has been modified to such an extent that its properties are not substantially impaired. Modified polyester resins include, for example, grafting or blocking 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, urethane-modified polyester resins obtained by urethane-extending a polyester resin with a polyisocyanate compound are preferred.

The softening point of the crystalline polyester resin C is preferably 50° C. or higher, more preferably 55° C. or higher, still more preferably 60° C. or higher from the viewpoint of durability, and preferably 120° C. or higher from the viewpoint of low-temperature fixability. °C or less, more preferably 110°C or less.

The melting point of the crystalline polyester resin C is preferably 60°C or higher, more preferably 65°C or higher, from the viewpoint of durability, and preferably 130°C or lower, more preferably 120°C, from the viewpoint of low-temperature fixability. It is below.

The acid value of the crystalline polyester resin C 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, or more from the viewpoint of durability. It is preferably 15 mgKOH/g or less.

The content of the crystalline polyester resin C is preferably 1% by mass or more, more preferably 3% by mass or more, more preferably 3% by mass or more, from the viewpoint of low-temperature fixability in the total amount of the crystalline polyester resin C and the amorphous resin A. is 4% by mass or more, and from the viewpoint of durability, it is preferably 45% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, and even more preferably 20% by mass or less.

Examples of the amorphous resin A include amorphous polyester resins, composite resins in which polyester resins and styrene resins are combined, polyamide resins, vinyl resins, epoxy resins, polycarbonate resins, polyurethane resins, and the like. Then, from the viewpoint of improving durability, amorphous polyester resins or composite resins are preferable, and amorphous polyester resins are more preferable.

As the amorphous polyester resin, a polycondensation product of an alcohol component containing an alkylene oxide adduct of bisphenol A and a carboxylic acid component is preferable.

The alkylene oxide adduct of bisphenol A has the formula (I):

(Wherein, OR and RO are oxyalkylene groups, R is an ethylene group and/or propylene group, x and y represent the average number of added moles of alkylene oxide, each being a positive number, and 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 still more preferably 4 or less)
A compound represented by is preferred.

From the viewpoint of low-temperature fixability, the content of the alkylene oxide adduct of bisphenol A 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, in the alcohol component. mol % or more, more preferably 100 mol %.

Other alcohol components include trihydric or higher alcohols such as aliphatic diols, bisphenol A, hydrogenated bisphenol A, sorbitol, pentaerythritol, glycerin, and trimethylolpropane.

Examples of the carboxylic acid component include aliphatic dicarboxylic acid-based compounds, aromatic dicarboxylic acid-based compounds, and trivalent or higher carboxylic acid-based compounds.

Aliphatic dicarboxylic acid compounds include fumaric acid, maleic acid, succinic acid, hydrocarbon-substituted succinic acid derivatives, glutaric acid, adipic acid, sebacic acid, anhydrides of these acids, and carbon atoms of these acids. Examples thereof include alkyl esters having a number of 1 or more and 3 or less.

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

Trivalent or higher carboxylic acid compounds include trimellitic acid, pyromellitic acid, anhydrides of these acids, alkyl esters of these acids having 1 to 3 carbon atoms, and the like.

In the present invention, the carboxylic acid component of the amorphous polyester resin preferably contains a succinic acid derivative substituted with a hydrocarbon group from the viewpoint of durability.

The hydrocarbon group in the succinic acid derivative substituted with a hydrocarbon group is preferably an alkyl group or an alkenyl group. Accordingly, specific examples of succinic acid derivatives substituted with a hydrocarbon group include dodecylsuccinic acid, dodecenylsuccinic acid, tetrapropenylsuccinic acid, decenylsuccinic acid, acid anhydrides thereof, and alkyl groups having 1 to 3 carbon atoms. Ester etc. are mentioned. Among these, dodecenylsuccinic acid, tetrapropenylsuccinic acid, or acid anhydrides thereof are preferred, and dodecenylsuccinic anhydride is more preferred, from the viewpoint of low-temperature fixability.

The number of carbon atoms in 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, from the viewpoint of hydrophobicity. It is more preferably 16 or less.

From the viewpoint of hydrophobicity, the succinic acid derivative is selected from the group consisting of succinic acid substituted with an alkyl group having 10 to 18 carbon atoms and succinic acid substituted by an alkenyl group having 10 to 18 carbon atoms. Those containing at least one or more are preferable, and are selected from the group consisting of succinic acid substituted with an alkyl group having 12 to 16 carbon atoms and succinic acid substituted by an alkenyl group having 12 to 16 carbon atoms. Those containing at least one or two or more are more preferable.

The content of the succinic acid derivative in the carboxylic acid component is preferably 1 mol% or more, more preferably 5 mol% or more, still more preferably 7 mol% or more from the viewpoint of hydrophobicity, and from the viewpoint of durability. Therefore, it is preferably 40 mol % or less, more preferably 35 mol % or less, still more preferably 20 mol % or less, and still more preferably 15 mol % or less.

The alcohol component may contain a monohydric alcohol, and the carboxylic acid component may contain a monovalent carboxylic acid-based compound, as appropriate.

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

Regarding the polycondensation reaction conditions of the alcohol component and the carboxylic acid component of the amorphous polyester resin, the suitable reaction temperature is preferably 130°C or higher, more preferably 170°C or higher, and preferably 250°C or lower, more preferably 240°C. ° C. or less, the reaction conditions are the same as those for the crystalline polyester resin.

In the composite resin containing the polyester resin and the styrene resin, the polyester resin is the same as the amorphous polyester resin, and the styrene resin is at least styrene or styrene such as α-methylstyrene and vinyl toluene. It is an addition polymer of raw material monomers containing derivatives (hereinafter, styrene and styrene derivatives are collectively referred to as "styrene compounds").

The content of a styrene compound, preferably styrene, is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 80% by mass or more, from the viewpoint of durability, in the raw material monomer of the styrene resin, From the viewpoint of low-temperature fixability, the content is preferably 95% by mass or less, more preferably 93% by mass or less, and even more preferably 90% by mass or less.

The styrene-based resin may also contain a (meth)acrylic acid alkyl ester having an alkyl group with 7 or more carbon atoms as a raw material monomer. Examples of (meth)acrylic acid alkyl esters include 2-ethylhexyl (meth)acrylate, (iso)octyl (meth)acrylate, (iso)decyl (meth)acrylate, and (iso)stearyl (meth)acrylate. mentioned. It is preferable to use one or more of these. In the present specification, "(iso)" means including both cases where this group exists and cases where it does not exist, and when these groups do not exist, normal indicates that Moreover, "(meth)acrylic acid" indicates acrylic acid, methacrylic acid, or both.

The number of carbon atoms in the alkyl group in the (meth)acrylic acid alkyl ester as the raw material monomer for the styrene resin is preferably 7 or more, more preferably 8 or more, from the viewpoint of improving the low-temperature fixability of the toner. is 12 or less, more preferably 10 or less. The number of carbon atoms in the alkyl ester refers to the number of carbon atoms derived from the alcohol component that constitutes the ester.

Raw material monomers for styrene resins 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; vinyl esters such as vinyl acetate and vinyl propionate; ethylenic 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 pyrrolidone may also be included.

The addition polymerization reaction of raw material monomers for styrenic resins is usually carried out in the presence of, for example, a polymerization initiator such as dibutyl peroxide or dicumyl peroxide, a polymerization inhibitor, a cross-linking agent, or the like, in the presence or absence of an organic solvent. The temperature conditions are preferably 110° C. or higher, more preferably 140° C. or higher, and preferably 200° C. or lower, more preferably 170° C. or lower.

When using an organic solvent for 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 monomer for the styrene resin.

The composite resin is preferably a resin in which a polyester resin and a styrenic resin are bonded, chemically bonding via a bi-reactive monomer that can react with both the raw material monomer of the polyester resin and the raw material monomer of the styrenic resin. It is more preferable that the resin is a

Both reactive monomers have, 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. A compound having a group, more preferably a carboxy group, and an ethylenically unsaturated bond is preferred, and at least one selected from the group consisting of acrylic acid, methacrylic acid, fumaric acid, maleic acid and maleic anhydride is more preferred, At least one selected from the group consisting of acrylic acid, methacrylic acid and fumaric acid is more preferable from the viewpoint of reactivity in polycondensation reaction and addition polymerization reaction. However, when used together with a polymerization inhibitor, polyvalent carboxylic acid compounds having an ethylenically unsaturated bond such as fumaric acid function as raw material monomers for polyester resins. In this case, fumaric acid or the like is not a bireactive monomer but a starting monomer for the polyester resin.

From the viewpoint of low-temperature fixability, the amount of the bi-reactive monomer used is preferably 1 mol or more, more preferably 2 mol or more, relative to the total 100 mol of the alcohol component of the polyester resin. From the viewpoint of enhancing the dispersibility with the polyester resin and improving the durability of the toner, the amount is preferably 30 mol or less, more preferably 20 mol or less, and even more preferably 10 mol or less.
In addition, from the viewpoint of low-temperature fixability, the amount of the bi-reactive monomer used is preferably 1 part by mass or more, more preferably 2 parts by mass or more, relative to a total of 100 parts by mass of raw material monomers for the styrene resin. From the viewpoint of increasing the dispersibility of the styrene-based resin and the polyester resin and improving the durability of the toner, the amount 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 sum of the raw material monomers for the styrene resin.

Specifically, the composite resin is preferably produced by the following method. When a bi-reactive monomer is used, the bi-reactive monomer is preferably used in the addition polymerization reaction together with the raw material monomer of the styrenic resin from the viewpoint of improving the durability and low-temperature fixability of the toner.

(i) A method in which the step (B) of the addition polymerization reaction with the raw material monomer of the styrene resin and the bi-reactive monomer is performed after the step (A) of the polycondensation reaction with the raw material monomer of the polyester resin. The step (A) is carried out under the reaction temperature conditions suitable for the reaction temperature, the reaction temperature is lowered, and the step (B) is carried out under the temperature conditions suitable for the addition polymerization reaction. It is preferable to add the raw material monomer of the styrene resin and the bi-reactive monomer into the reaction system at a temperature suitable for the addition polymerization reaction. Both reactive monomers undergo an addition polymerization reaction and also react with the polyester resin.
After the step (B), the reaction temperature is raised again, and if necessary, a raw material monomer for a polyester resin having a valence of 3 or more, which serves as a cross-linking agent, is added to the polymerization system, and the polycondensation reaction or both reactions of the step (A) are performed. Further reaction with a reactive monomer can proceed.

(ii) A method in which the step (A) of the polycondensation reaction with the raw material monomer of the polyester resin is performed after the step (B) of the addition polymerization reaction with the raw material monomer of the styrene resin and the bireactive monomer. In this method, the addition polymerization reaction is performed. The step (B) is carried out under reaction temperature conditions suitable for the above conditions, the reaction temperature is increased, and the polycondensation reaction of step (A) is carried out under temperature conditions suitable for the polycondensation reaction. Both reactive monomers participate in addition polymerization reactions as well as polycondensation reactions.
The raw material monomers for 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 controlled by adding the esterification catalyst at a temperature suitable for the polycondensation reaction.

(iii) The step (A) of the polycondensation reaction by the raw material monomer of the polyester resin and the step (B) of the addition polymerization reaction by the raw material monomer of the styrene resin and the bi-reactive monomer are carried out in parallel. In this method, step (A) and step (B) are performed in parallel under reaction temperature conditions suitable for addition polymerization reaction, the reaction temperature is raised, and under temperature conditions suitable for polycondensation reaction, It is preferable to add a raw material monomer of a polyester resin having a valence of 3 or more to the polymerization system as a cross-linking agent, if necessary, and further carry out the polycondensation reaction of the step (A). At that time, under temperature conditions suitable for the polycondensation reaction, a polymerization inhibitor may be added to allow the polycondensation reaction alone to proceed. Both reactive monomers participate in addition polymerization reactions as well as polycondensation reactions.

In the method (i) above, a prepolymerized polycondensation resin may be used instead of the step (A) of conducting the polycondensation reaction. In the above method (iii), when the reaction is carried out under conditions in which step (A) and step (B) proceed in parallel, a raw material monomer for a styrene resin is added to a mixture containing a raw material monomer for a polyester resin. can also be added dropwise to react.

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

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

The softening point of the amorphous resin A is preferably 90° C. or higher, more preferably 100° C. or higher, from the viewpoint of durability, and preferably 150° C. or lower, more preferably 140° C. or lower, from the viewpoint of low-temperature fixability. ℃ or less.

From the viewpoint of low-temperature fixability and fixation width, the amorphous resin A may be made of resins having different softening points. The difference in softening points between the two resins is preferably 10°C or higher, more preferably 12°C or higher, and preferably 60°C or lower, more preferably 30°C or lower, and even more preferably 20°C or lower.

The softening point of the amorphous resin having a higher softening point (resin AH) is preferably 100° C. or higher, more preferably 110° C. or higher, and still more preferably 120° C. or higher, from the viewpoint of fixing width. From the viewpoint of fixability, the temperature is preferably 180° C. or lower, more preferably 160° C. or lower, and even more preferably 140° C. or lower.

In addition, the softening point of the amorphous resin (resin AL) having a lower softening point is preferably 70°C or higher, more preferably 90°C or higher, further preferably 100°C or higher, from the viewpoint of durability, 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.

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.

The glass transition temperature of the amorphous resin A is preferably 40°C or higher, more preferably 50°C or higher, from the viewpoint of durability, and preferably 80°C or lower, more preferably 80°C or lower, from the viewpoint of low-temperature fixability. It is 70°C or lower, more preferably 65°C or lower.

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, or more from the viewpoint of durability. It is preferably 15 mgKOH/g or less.

The number average molecular weight of the amorphous resin A is preferably 1,000 or more, more preferably 1,500 or more, and still more preferably 2,000 or more from the viewpoint of durability, and preferably 6,000 or less from the viewpoint of low temperature fixability. It is more preferably 5,000 or less, still more preferably 4,000 or less.

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

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, from the viewpoint of low-temperature fixability. , more preferably 5/95 or more, and from the viewpoint of durability, preferably 40/60 or less, more preferably 35/65 or less, and even more preferably 30/70 or less.

The toner contains the crystalline polyester resin C and the amorphous resin A as binder resins.

Other binder resins include vinyl resins such as styrene acrylic resins, epoxy resins, polycarbonates, polyurethanes, composite resins containing two or more of these resins, and the like.

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

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

Release agents include hydrocarbon waxes such as polypropylene wax, polyethylene wax, polypropylene polyethylene copolymer wax, microcrystalline wax, paraffin wax, Fischer-Tropsch wax, oxides thereof; carnauba wax, montan wax and their Ester waxes such as deacidified waxes and fatty acid ester waxes; fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts and the like; these may be used alone or in combination of two or more.

The melting point of the release agent is preferably 60° C. or higher, more preferably 70° C. or higher from the viewpoint of durability, and preferably 160° C. or lower, more preferably 140° C. or lower from the viewpoint of low-temperature fixability. It is more preferably 120° C. or lower, still more preferably 110° C. or lower.

The content of the release agent is preferably 0.5 parts by mass or more, more preferably 0.5 parts by mass or more, based on 100 parts by mass of the binder resin, from the viewpoints of low-temperature fixability and durability of the toner and dispersibility in the binder resin. is 1 part by mass or more, more preferably 1.5 parts by mass or more, and is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, and still more preferably 7 parts by mass or less.

In addition to the binder resin and the release agent, the toner contains a colorant, a charge control agent, a magnetic powder, a fluidity improver, a conductivity modifier, a reinforcing filler such as a fibrous substance, an antioxidant, and a cleanability improver. It may contain additives such as

As the coloring agent, dyes, pigments, magnetic substances, etc., which are used as coloring agents for toners, can be used. For example, Carbon Black, Phthalocyanine Blue, Permanent Brown FG, Brilliant First Scarlet, Pigment Red 122, Pigment Green B, Rhodamine-B Base, Solvent Red 49, Solvent Red 146, Solvent Blue 35, Quinacridone, Carmine 6B, Isoindoline, Disazo Yellow. etc. In the present invention, the toner may be either black toner or color toner.

The content of the colorant is preferably 1 part by mass or more, more preferably 2 parts by mass or more with respect to 100 parts by mass of the binder resin, from the viewpoint of improving the image density and low-temperature fixability of the toner, and It is 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.

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

Examples of positive charge control agents include nigrosine dyes such as "Nigrosine Base EX", "Oil Black BS", "Oil Black SO", "Bontron N-01", "Bontron N-04", and "Bontron N-07". , "Bontron N-09", "Bontron N-11" (manufactured by Orient Chemical Industry Co., Ltd.), etc.; triphenylmethane dyes containing tertiary amines as side chains; quaternary ammonium salt compounds, such as "Bontron P-51" (manufactured by Orient Chemical Industry Co., Ltd.), cetyltrimethylammonium bromide, "COPY CHARGE PX VP435" (manufactured by Clariant Co., Ltd.), etc.; ), etc.; imidazole derivatives, such as “PLZ-2001” and “PLZ-8001” (manufactured by Shikoku Kasei Co., Ltd.), etc.; styrene-acrylic resins, such as “FCA-701PT” and “FCA-201- PS" (manufactured by Fujikura Kasei Co., Ltd.) and the like.

In addition, as a negative charge control agent, a metal-containing azo dye such as "Barifast Black 3804", "Bontron S-31", "Bontron S-32", "Bontron S-34", "Bontron S-36" ” (manufactured by Orient Chemical Industry Co., Ltd.), “Aizenspiron Black TRH”, “T-77” (manufactured by Hodogaya Chemical Industry Co., Ltd.), etc.; metal compounds of benzilic 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 Industry Co., Ltd.), "TN-105" (manufactured by Hodogaya Chemical Industry Co., Ltd.), etc.; copper phthalocyanine dye; quaternary ammonium salt, such as "COPY CHARGE NX VP434" (manufactured by Clariant), nitroimidazole derivatives and the like; organometallic compounds and the like.

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

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

The mixture to be melt-kneaded may be kneaded all at once or divided and kneaded. After mixing in advance with a mixer such as a Henschel mixer or ball mill, the mixture is fed to an open-roll type twin-screw kneader. is preferred.

An open-roll type twin-screw kneader is equipped with two rolls and the melt-kneading section is open rather than sealed, so that the kneading heat generated during melt-kneading can be easily dissipated. can. The open roll type twin screw kneader used in the present invention is equipped with a plurality of raw material supply ports and a kneaded product discharge port provided along the axial direction of the rolls, and from the viewpoint of production efficiency, a continuous open roll A type twin-screw kneader is preferred.

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, a high-rotation roll with a high peripheral speed and a low-rotation roll with a low peripheral speed. is. In the present invention, from the viewpoint of improving the dispersibility of the crystalline polyester resin, it is preferable that the high rotation roll is a heating roll and the low rotation roll is a cooling roll.

The temperature of the rolls can be adjusted, for example, by the temperature of the heat medium passing through the rolls, and heat mediums having different temperatures may be passed through each roll by dividing the inside of the rolls into two or more.

From the viewpoint of improving the dispersibility of the crystalline polyester resin, the temperature on the kneaded product discharge side of the high rotation roll is -20°C or higher, preferably -15°C or higher, more preferably -15°C or higher, which is the melting point of the crystalline polyester resin C. is -10°C or higher, more preferably -5°C or higher, more preferably the melting point or higher, and is +15°C or lower, preferably +13°C or lower, more preferably +13°C or lower than the melting point of the crystalline polyester resin C. +12°C or less.

On the other hand, from the viewpoint of melting the crystalline polyester resin, the temperature on the raw material input side of the high-rotation roll is preferably +5°C or higher, more preferably +15°C or higher, and even more preferably +15°C or higher than the melting point of the crystalline polyester resin C. +25°C or higher, more preferably +40°C or higher, and preferably +65°C or lower, more preferably +60°C or lower, still more preferably +55°C or lower than the melting point of the crystalline polyester resin C .

From the viewpoint of improving the dispersibility of the crystalline polyester resin, the temperature on the kneaded product discharge side of the low-rotation roll is preferably 25°C or higher, more preferably 30°C or higher, and preferably 80°C or lower, more preferably 80°C or lower. is below 50°C.

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

Both the high rotation roll and the low rotation roll preferably have a higher temperature on the raw material input side than the kneaded material discharge side, and the temperature difference between the raw material input side and the kneaded material discharge side of the high rotation roll is the kneading From the viewpoint of preventing the product from coming off the rolls, reducing the mechanical force during melt-kneading, and suppressing heat generation, the temperature is preferably 5°C or higher, more preferably 20°C or higher, and still more preferably 25°C or higher. , and preferably 60° C. or less, more preferably 55° C. or less. The temperature difference between the raw material input side and the kneaded product output side of the low rotation roll is preferable from the viewpoint of improving the dispersibility of the crystalline polyester resin, reducing the mechanical force during melt kneading, and suppressing heat generation. is greater than or equal to 5°C and preferably less than or equal to 50°C

The temperature on the raw material input side of the high rotation roll and the low rotation roll indicates the set temperature of the raw material input side end, and the temperature on the kneaded product discharge side indicates the set temperature on the kneaded product discharge side.

The peripheral speed of the high-rotation roll is preferably 2 m/min or more, more preferably 10 m/min, from the viewpoints of improving the dispersibility of the crystalline polyester resin, reducing the mechanical force during melt-kneading, and suppressing heat generation. min or more, more preferably 25 m/min or more, and preferably 100 m/min or less, more preferably 75 m/min or less, and even more preferably 50 m/min or less. From the same viewpoint, the peripheral speed of the low rotation 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 It is 60 m/min or less, more preferably 30 m/min or less. In addition, the ratio of the peripheral speeds of the two rolls (low rotation roll/high rotation roll) is preferably 1/10 or more, more preferably 3/10 or more, and preferably 9.9/10 or less, more preferably is less than 8/10.

Moreover, there are no particular restrictions on the structure, size, material, etc. of each roll. The roll surface has grooves used for kneading, and the shape thereof may be linear, spiral, corrugated, uneven, or the like.

After melt-kneading, it is preferable to appropriately cool the kneaded material until it reaches a pulverizable hardness, and if necessary, perform a pulverization step and classification to obtain toner particles. Here, cooling means cooling the kneaded material to 0° C. or more and 50° C. or less, or cooling it to the glass transition temperature or less of the binder resin in the kneaded material.

In the pulverization of the kneaded material, the kneaded material may be pulverized to a desired particle size at once or in stages. It is preferable to carry out in two steps.

Pulverizers used for coarse pulverization include hammer mills, cutter mills, atomizers, Rotoplex and the like.

In coarse pulverization, it is preferable to pulverize until the maximum diameter becomes 3 mm or less. For example, pulverized material with a maximum diameter of 3 mm or less is 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 opening of 3 mm. Obtainable.

Pulverizers used for fine pulverization include jet mills such as fluidized bed jet mills and impingement plate jet mills, and mechanical mills.

The degree of fine pulverization is preferably adjusted appropriately according to the desired particle size of the toner particles.

Classifiers used for classification include air classifiers, inertial classifiers, sieve classifiers, and the like. In the classification step, the pulverized material removed due to insufficient pulverization may be subjected to the pulverization step again, and the pulverization step and the classification step may be repeated as necessary.

In the present invention, it is preferable to further include an external addition step of mixing the obtained toner particles with an external additive.

External additives include inorganic fine particles such as silica, alumina, titania, zirconia, tin oxide and zinc oxide, and organic fine particles such as resin particles such as melamine resin fine particles and polytetrafluoroethylene resin fine particles. The above may be used in combination. Among these, silica is preferable, and from the viewpoint of durability of the toner, hydrophobic silica subjected to a hydrophobic treatment is more preferable.

Examples of hydrophobizing agents for hydrophobizing the surface of silica particles include hexamethyldisilazane (HMDS), dimethyldichlorosilane (DMDS), cyclic silazane, silicone oil, aminosilane, octyltriethoxysilane (OTES), and methyltriethoxysilane (OTES). ethoxysilane and the like.

The average particle size of the external additive is preferably 5 nm or more, more preferably 10 nm or more, still more preferably 15 nm or more, and is preferably 250 nm or less, more preferably 200 nm, from the viewpoint of toner chargeability and fluidity. Below, more preferably 90 nm or less.

The content of the external additive is preferably 0.05 parts by mass or more, more preferably 0.1 part by mass or more, with respect to 100 parts by mass of the toner particles before being treated with the external additive, from the viewpoint of charging property and fluidity of the toner. , more preferably 0.3 parts by mass or more, and preferably 5 parts by mass or less, more preferably 3 parts by mass or less.

The volume median particle size ( _D50 ) 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 particle size (D ₅₀ ) means a particle size at which the cumulative volume frequency calculated as a volume fraction is 50% from the smaller particle size. When the toner is treated with an external additive, the volume median particle size of the toner particles before being treated with the external additive is taken as the volume median particle size of the toner.

The toner obtained by the method of the present invention is used as a one-component developing toner as it is or as a two-component developing toner mixed with a carrier in an image forming apparatus of a one-component developing system or a two-component developing system, respectively. be able to.

EXAMPLES The present invention will be specifically described below with reference to Examples, but the present invention is not limited to these Examples. Physical properties of resins and the like can be measured by the following methods.

[Resin softening point]
Using a flow tester "CFT-500D" (manufactured by Shimadzu Corporation), while heating a 1 g sample at a temperature increase rate of 6 ° C / min, a load of 1.96 MPa was applied with a plunger, and the diameter was 1 mm and the length was 1 mm. extruded from the nozzle of Plot the amount of plunger descent of the flow tester against the temperature, and let the softening point be the temperature at which half of the sample flows out.

[Maximum peak temperature of resin absorption]
Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan Co., Ltd.), weigh 0.01 to 0.02 g of the sample in an aluminum pan and cool it from room temperature (25 ° C) to a cooling rate of 10 ° C. /min to 0°C and hold at 0°C for 1 minute. After that, measure at a heating rate of 10°C/min. Among the observed endothermic peaks, the temperature of the peak having the maximum peak area is defined as the maximum endothermic peak temperature.

[Glass transition temperature of amorphous resin]
Using a differential scanning calorimeter "Q-100" (manufactured by TA Instruments Japan), weigh 0.01 to 0.02 g of the sample in an aluminum pan, raise the temperature to 200 ° C, and then decrease the cooling rate from that temperature. Cool to 0°C at 10°C/min. Next, the sample is heated at a heating rate of 10°C/min, and the endothermic peak is measured. The glass transition temperature is defined as the temperature at the intersection of the extended line of the baseline below the maximum endothermic peak temperature and the tangent line showing the maximum slope from the rising portion of the peak to the apex of the peak.

[Acid value of resin]
Measured based on the method of JIS K 0070:1992. However, JIS K 0070 specified mixed solvent of ethanol and ether for the measurement solvent, mixed solvent of acetone and toluene (acetone:toluene = 1:1 (volume ratio)) for amorphous resin, and chloroform for crystalline resin. and dimethylformamide (chloroform:dimethylformamide = 7:3 (volume ratio)).

[Number average molecular weight and weight average molecular weight of resin]
The number average molecular weight and weight average molecular weight are obtained by gel permeation chromatography (GPC) by the following method.
(1) Preparation of sample solution A resin was dissolved in tetrahydrofuran so that the concentration was 0.5 g/100 mL. Then, this solution is 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 to obtain a sample solution.
(2) Molecular weight measurement Using the following measuring apparatus and analytical column, tetrahydrofuran is passed as an eluent at a flow rate of 1 mL per minute, and the column is stabilized in a constant temperature bath at 40°C. 100 μL of the sample solution was injected there and measured. The molecular weight of the sample is calculated based on a previously prepared calibration curve. The calibration curve at this time includes several types of monodisperse polystyrene with known molecular weights (manufactured by Tosoh Corporation; ^2.63 × 10 ³ , 2.06 × 10 ⁴ , 1.02 × 10 ⁵ ; , 7.00×10 ³ , 5.04×10 ⁴ ) as standard samples.
Measuring device: CO-8010 (trade name, manufactured by Tosoh Corporation)
Analysis column: GMH _XL + G3000H _XL (both trade names, manufactured by Tosoh Corporation)

[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 to 200 ° C, and then cooled at a rate of 10 ° C from 200 ° C. /min to 0°C. Next, the temperature of the sample is increased at a temperature increase rate of 10°C/min, the calorie is measured, and the maximum endothermic peak temperature is defined as the melting point.

[Average particle size of external additive]
The average particle size refers to the number average particle size, and the particle size (average value of major and minor axes) of 500 particles is measured from a scanning electron microscope (SEM) photograph, and the number average value thereof is taken.

[Volume Median Particle Diameter of Toner ( _D50 )]
・Measuring machine: “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: Polyoxyethylene lauryl ether "Emulgen (registered trademark) 109P" [manufactured by Kao Corporation, HLB (Griffin) = 13.6] was dissolved in the electrolytic solution to adjust it to 5% by mass. ・Dispersion conditions: Add 10 mg of the measurement sample to 5 mL of the dispersion liquid, disperse 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 electrolytic solution, Furthermore, it is dispersed for 1 minute with an ultrasonic disperser to prepare a sample dispersion.
・Measurement conditions: By adding the sample dispersion to 100 mL of the electrolytic solution, the particle size of 30,000 particles is adjusted to a concentration that can be measured in 20 seconds, and then 30,000 particles are measured. The volume median particle size ( _D50 ) is determined from the distribution.

Alkenyl succinic anhydride production example 1
(1) Using propylene tetramer (manufactured by Nippon Oil Co., Ltd., trade name: "Light Tetramer"), fractional distillation was performed under heating conditions of 183 to 208°C to obtain an alkylene compound (a). The obtained alkylene compound (a) had 40 peaks in gas chromatography mass spectrometry, which will be described later. The distribution of the alkylene compounds was measured according to the analysis by mass spectrometry gas chromatography of alkylene compound A in JP-A-2014-013384, and C ₉ H ₁₈ : 0.5% by mass, C ₁₀ H ₂₀ : 4% by mass, C ₁₁ H ₂₂ : 20% by mass, _C12H24 : 66% _{by mass} , _C13H26 : 9% by mass, _C14H28 : _0.5 % by mass (6 peaks corresponding to alkylene compounds having 9 to 14 carbon atoms). rice field.

(2) 542.4 g of alkylene compound (a), 157.2 g of maleic anhydride, and 0.4 g of antioxidant "Chelex-O" (Triisooctyl phosphite, manufactured by SC Organic Chemical Co., Ltd.) in a 1-liter autoclave manufactured by Nitto Koatsu Co., Ltd. , and 0.1 g of butyl hydroquinone as a polymerization inhibitor were charged, and pressurized nitrogen substitution (0.2 MPaG) was repeated three times. After stirring was started at 60°C, the temperature was raised to 230°C over 1 hour and the reaction was carried out for 6 hours. The pressure when reaching the reaction temperature was 0.3 MPaG. After completion of the reaction, the reaction mixture 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 residual alkylene compound was distilled off at 1.3 kPa in 1 hour. Subsequently, after cooling to room temperature (25°C), the pressure was returned to normal pressure (101.3 kPa) to obtain 406.1 g of the desired product, alkenyl succinic anhydride A. The average molecular weight of alkenyl succinic anhydride A determined from the acid value was 268.

Resin production example 1
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 flow-down condenser and a nitrogen inlet tube, and placed in a mantle heater in a nitrogen atmosphere. The temperature was raised to 200°C over 8 hours. After that, 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 crystalline polyester resins (resins C1 to C7). Physical properties are shown in Table 1.

Resin production example 2
The polyester resin raw material monomers other than trimellitic anhydride, the esterification catalyst and the esterification co-catalyst shown in Table 2 are placed in a 5-liter four-necked flask equipped with a nitrogen inlet tube, a stirrer and a thermocouple. After heating to 235°C in a nitrogen atmosphere, polycondensation was carried out at 235°C for 6 hours. After that, the temperature was lowered to 210°C, trimellitic anhydride was added, and the mixture was reacted at 210°C for 1 hour, and further reacted at 210°C under a reduced pressure of 10 kPa until the softening point shown in Table 2 was reached. An amorphous polyester resin (resin AH1) was obtained. Physical properties are shown in Table 2.

Resin production example 3
Raw material monomers for polyester resins other than trimellitic anhydride and fumaric acid shown in Table 2, an esterification catalyst and an esterification co-catalyst were added to a 5-liter container equipped with a dehydration tube equipped with a nitrogen inlet tube, a stirrer and a thermocouple. It was placed in a four-necked flask, heated to 235°C under a nitrogen atmosphere, and then polycondensed at 235°C for 6 hours. After that, the temperature was lowered to 160° C., and a mixture of both reactive monomers, raw material monomers for styrenic resin, and a polymerization initiator was added dropwise from a dropping funnel over 1 hour. After the dropwise addition, the addition polymerization reaction was aged for 1 hour while the temperature was maintained at 160°C, then the temperature was raised to 200°C and the pressure was reduced at 10 kPa for 1 hour. After the pressure is released, the temperature is lowered to 180°C, trimellitic anhydride, fumaric acid, and a polymerization inhibitor shown in Table 2 are added, and the temperature is maintained at 180°C for 1 hour, and then the temperature is raised from 180°C to 210°C at a rate of 10°C/h. It was warmed and reacted at 210° C. for 1 hour. Furthermore, the reaction was carried out at 210° C. under a reduced pressure of 10 kPa until the softening point shown in Table 2 was reached to obtain an amorphous composite resin (resin AH2). Physical properties are shown in Table 2.

Resin production example 4
Raw material monomers for polyester resins other than trimellitic anhydride and fumaric acid, esterification catalysts and esterification co-catalysts shown in Table 2 were added to a 5-liter four-necked flask equipped with a nitrogen inlet tube, a stirrer and a thermocouple. After the temperature was raised to 235°C in a nitrogen atmosphere, polycondensation was carried out at 235°C for 6 hours. After that, the temperature was lowered to 180°C, trimellitic anhydride, fumaric acid, and a polymerization inhibitor were added, and after keeping the temperature at 180°C for 1 hour, the temperature was raised from 180°C to 210°C at a rate of 10°C/h, and the temperature was raised to 210°C. React for 1 hour. Furthermore, the reaction was carried out at 210° C. under a reduced pressure of 10 kPa until the softening point shown in Table 2 was reached to obtain an amorphous polyester resin (resin AH3). Physical properties are shown in Table 2.

Resin production example 5
The polyester resin raw material monomer, esterification catalyst and esterification co-catalyst shown in Table 2 were placed in a 5-liter four-necked flask equipped with a nitrogen inlet tube, a stirrer and a thermocouple, and heated to 235°C under a nitrogen atmosphere. After the temperature was raised to 235° C., polycondensation was performed for 6 hours. After that, 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 amorphous polyester resins (resins AL1 and AL3). Physical properties are shown in the table.

Resin production example 6
The polyester resin raw material monomers other than fumaric acid, the esterification catalyst, and the esterification co-catalyst shown in Table 2 were added to a 5-liter four-necked flask equipped with a dehydration tube equipped with a nitrogen inlet tube, a stirrer, and a thermocouple. After the temperature was raised to 235°C in a nitrogen atmosphere, polycondensation was carried out at 235°C for 6 hours. After that, the temperature was lowered to 160° C., and a mixture of both reactive monomers, raw material monomers for styrenic resin, and a polymerization initiator was added dropwise from a dropping funnel over 1 hour. After the dropwise addition, the addition polymerization reaction was aged for 1 hour while the temperature was maintained at 160°C, then the temperature was raised to 200°C and the pressure was reduced at 10 kPa for 1 hour. After the pressure was released, the temperature was lowered to 180°C, fumaric acid and a polymerization inhibitor shown in Table 2 were added, the temperature was maintained at 180°C for 1 hour, the temperature was raised from 180°C to 210°C at a rate of 10°C/h, and the temperature was increased to 210°C. React for 1 hour. Furthermore, the reaction was carried out at 210° C. under a reduced pressure of 10 kPa until the softening point shown in Table 2 was reached to obtain an amorphous composite resin (resin AL2). Physical properties are shown in Table 2.

Examples 1-10 and Comparative Examples 1-5
100 parts by mass of binder resin shown in Table 3, 5 parts by mass of colorant "ECB-301" (manufactured by Dainichiseika Co., Ltd., phthalocyanine blue (PB15:3)), mold release agent "Carnauba Wax C1" (Kato Yoko Co., Ltd.) Melting point: 83°C) 3 parts by mass, release agent “HNP-9” (manufactured by Nippon Seiro Co., Ltd., paraffin wax, melting point: 75°C) 3 parts by mass, and charge control agent “Bontron E-304” (Orient Kagaku Co., Ltd.) was mixed with a Henschel mixer.

The obtained raw material mixture was supplied to a continuous open-roll type twin-screw kneader “Kneedex” (manufactured by Mitsui Mining Co., Ltd.) using a table feeder and kneaded 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. /min (peripheral speed 33 m/min), the rotation speed of the low-rotation roll (rear roll) was 50 r/min (peripheral speed 22 m/min), and the roll gap was 0.1 mm. Regarding the heating and cooling medium temperatures in the rolls, the temperature of the raw material input side (IN) and the kneaded product output side (OUT) of the high rotation rolls were set to the temperatures shown in Table 3, and the temperature of the raw material input side of the low rotation rolls was set to the temperature shown in Table 3. The temperature of 65°C and the temperature of the kneaded product discharge side were set to 30°C. The feed rate of the raw material mixture was 10 kg/h, and the average residence time was about 5 minutes.

The resulting kneaded product was cooled to 25°C and coarsely pulverized with a pulverizer "Rotoplex" (manufactured by Toa Kikai Co., Ltd.) to obtain a coarsely 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 (coarse powder removal) were performed with a counter jet mill "400AFG" (manufactured by Hosokawa Alpine Co., Ltd.). Furthermore, lower limit classification (fine powder removal) was performed using a classifier "TTSP" (manufactured by Hosokawa Alpine Co., Ltd.) to obtain toner particles having a volume median particle diameter of 6.5 µm.

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

Test Example 1 [Low Temperature Fixability of Toner]
Toner was installed in a copier "AR-505" (manufactured by Sharp Corporation) whose fixing unit was improved so that it could be fixed outside the device, and printed matter was obtained in an unfixed state (printing area: 2 cm x 12 cm, coating weight: 0.5 mg/cm ² ). After that, using a fixing machine (fixing speed of 300 mm/sec) adjusted so that the total fixing pressure is 40 kgf, the temperature of the fixing roll is increased from 100°C to 200°C in increments of 5°C, and unfixed at each temperature. A fixing test of the printed matter in the state was performed. Adhesive cellophane tape "Unicef Cellophane" (manufactured by Mitsubishi Pencil Co., Ltd., width: 18mm, JIS Z1522:2009) was pasted on the image portion of the printed matter, and the temperature was set to 30°C, separate from the fixing roll of the fixing machine. After passing through a fixed fixing roller, the tape was peeled off. The optical reflection density before the tape was applied and after it was removed was measured using a reflection densitometer "RD-915" (manufactured by Gretag Macbeth). was taken as the lowest fixing temperature. Table 3 shows the results. The lower the minimum fixing temperature, the better the low-temperature fixability. As the fixing paper, "CopyBond SF-70NA" (manufactured by Sharp Corporation, 75 g/m ² ) was used.

Test Example 2 [Durability of Toner]
Toner was mounted on a printing machine "Page Presto N-4" (manufactured by Casio Computer Co., Ltd., fixing: contact fixing method, development: non-magnetic one-component development method, development roll diameter: 2.3 cm), temperature 32°C, humidity A diagonal stripe pattern with a blackening rate of 5.5% was continuously printed under an environment of 85%. On the way, a solid black image was printed every 500 sheets, and the presence or absence of streaks on the image was checked. Printing was stopped when streaks appeared on the image, and printing was carried out up to 9000 sheets. The number of printed sheets until streaks were visually observed on the image was regarded as the number of sheets on which streaks were generated due to fusion and adhesion of the toner to the developing roll, and the durability was evaluated. Table 3 shows the results. It can be determined that the greater the number of printed sheets until streaks occur, that is, the greater the number of printed sheets without streaks, the higher the durability of the toner. In the table, ">9000" means that no streak was observed after printing 9000 sheets.

From the above results, Comparative Examples 1 and 2 in which the temperature on the discharge side of the kneaded product of the high-rotation rolls of the open-roll type twin-screw kneader was outside the predetermined range and crystalline polyester resins not using the predetermined raw material monomers were used. As compared with Comparative Examples 3 to 5, the toners of Examples 1 to 10 are excellent in both low-temperature fixability and durability.

The electrostatic charge image developing toner obtained by the method of the present invention is suitably used for developing latent images formed by electrophotography, electrostatic recording, electrostatic printing and the like.

Claims (2)

A method for producing a toner for electrostatic charge image development containing a crystalline polyester resin C, an amorphous resin A, and a release agent, wherein the crystalline polyester resin C contains an aliphatic diol having 8 to 10 carbon atoms. A polycondensation product of an alcohol component and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 6 to 10 carbon atoms, containing a crystalline polyester resin C, an amorphous resin A, and a release agent. The mixture is melt-kneaded using an open-roll twin-screw kneader equipped with two rolls with different peripheral speeds, and the kneaded product discharge side of the high-rotation roll of the open-roll-type twin-screw kneader A method for producing a toner for developing an electrostatic charge image, wherein the temperature is -20°C or higher and +15°C or lower than the melting point of the crystalline polyester resin C. 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.