JP2017151149A - Toner for electrophotography - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrophotographic toner excellent in low temperature fixing property and heat resistant storage property. SOLUTION: The polyester component is at least a polycondensate of an alcohol component containing an aliphatic diol having 9 to 14 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 9 to 14 carbon atoms. A binder resin containing a crystalline resin (C) and an ester wax (W) which is an aliphatic carboxylic acid ester of dipentaerythritol having 14 to 24 carbon atoms, and crystallinity to the ester wax (W) The mass ratio (C / W) of the resin (C) is 1.0 or more and 40 or less, and the content of the crystalline resin (C) is 1% by mass or more and 25% by mass or less with respect to the total amount of the binder resin. Is a toner for electrophotography. [Selection diagram] None

Description

  The present invention relates to an electrophotographic toner.

In recent years, with the speeding up and energy saving of printers and copiers, toners that can meet these demands have become necessary.
In Patent Document 1, at least a binder resin, a colorant, a release agent, and a crystalline polyester are used as a means for solving the problem of achieving both winding and low temperature offset that occur when using a high-speed machine and development stability in long-term use. In the toner containing toner, the release agent is mainly composed of a hexafunctional or higher alkyl carboxylic acid ester, and the THF-insoluble content derived from the binder resin component when the toner is subjected to Soxhlet extraction with tetrahydrofuran (THF). In which toner is 5.0 mass% or more and 50.0 mass% or less is described.

JP 2010-145550 A

Ester wax tends to exhibit excellent dispersibility in the binder resin as compared to wax such as hydrocarbon wax. However, it is known that all waxes including ester wax generally deteriorate in storage stability as the blending amount increases.
In Patent Document 1, an ester wax having dipentaerythritol as a constituent component is used. Here, the crystalline polyester contained in the toner is a polycondensation reaction of a monomer composition containing, as main components, an aliphatic diol having 2 to 22 carbon atoms and an aliphatic dicarboxylic acid having 2 to 22 carbon atoms. Specifically, a short-chain aliphatic diol such as diethylene glycol or 1,6-hexanediol and a long-chain aliphatic dicarboxylic acid such as 1,10-decanedicarboxylic acid can be obtained. Only crystalline polyesters obtained by polycondensation are disclosed. The toner has not yet been sufficiently satisfactory in terms of both low-temperature fixability and heat-resistant storage stability.
The present invention relates to an electrophotographic toner excellent in low-temperature fixability and heat-resistant storage stability.

  Therefore, as a result of diligent study by the present inventors, dipentaerythritol has been developed for a crystalline resin that is a polycondensate of an aliphatic diol having a predetermined carbon number and an aliphatic carboxylic acid having a predetermined carbon number. Containing an ester wax (W), which is an aliphatic carboxylic acid ester having 14 to 24 carbon atoms, in a specific ratio, contrary to conventional common sense, addition of ester wax (W) allows heat-resistant storage of electrophotographic toner. It has been found that an electrophotographic toner can be obtained that has both low-temperature fixability and heat-resistant storage stability.

The present invention
A crystalline resin having at least a polyester moiety that is a polycondensate of an alcohol component containing an aliphatic diol having 9 to 14 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 9 to 14 carbon atoms ( A binder resin comprising C);
An ester wax (W) that is an aliphatic carboxylic acid ester of dipentaerythritol having 14 to 24 carbon atoms,
The mass ratio (C / W) of the crystalline resin (C) to the ester wax (W) is 1.0 or more and 40 or less,
The present invention relates to an electrophotographic toner in which the content of the crystalline resin (C) is 1% by mass or more and 25% by mass or less with respect to the total amount of the binder resin.

  According to the present invention, it is possible to provide an electrophotographic toner excellent in low-temperature fixability and heat-resistant storage stability.

[Electrophotographic toner]
The toner for electrophotography of the present invention is a polycondensate of an alcohol component containing an aliphatic diol having 9 to 14 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 9 to 14 carbon atoms. A binder resin containing a crystalline resin (C) having at least a polyester moiety;
And an ester wax (W) that is an aliphatic carboxylic acid ester of dipentaerythritol having 14 to 24 carbon atoms.
Furthermore, in the electrophotographic toner of the present invention,
The mass ratio (C / W) of the crystalline resin (C) to the ester wax (W) is 1.0 or more and 40 or less,
The content of the crystalline resin (C) is 1% by mass or more and 25% by mass or less with respect to the total amount of the binder resin.
According to the electrophotographic toner of the present invention, an electrophotographic toner excellent in low-temperature fixability and heat-resistant storage stability can be obtained.

The reason why the effect of the present invention is obtained is not clear, but can be considered as follows.
When a crystalline resin is used for an electrophotographic toner, crystallization may be hindered by coexistence with the wax, and the dispersibility of the wax in the binder resin may be insufficient. It is probable that there was a problem from the viewpoint of preservability.
In the present invention, the crystalline resin (C) is a polycondensate of an aliphatic diol having a predetermined carbon number and an aliphatic carboxylic acid having a predetermined carbon number, and the ester wax (W) is carbon of dipentaerythritol. It is an aliphatic carboxylic acid ester having a number of 14 or more and 24 or less, and a combination of these is specified. Furthermore, the content of the crystalline resin (C) and the ester wax (W) is defined as a specific ratio.
The long-chain aliphatic hydrocarbon portion of each of the aliphatic diol and aliphatic carboxylic acid of the crystalline resin (C) interacts with the aliphatic carboxylic acid portion having 14 to 24 carbon atoms of the ester wax (W). It is presumed that high dispersibility was obtained, and as a result, the effect of the present invention was obtained.

[Mass ratio (C / W)]
The mass ratio (C / W) of the crystalline resin (C) to the ester wax (W) is 1.0 or more and 40 or less from the viewpoint of obtaining excellent low-temperature fixability and heat-resistant storage stability.
The mass ratio (C / W) is preferably 1.0 or more, more preferably 1.5 or more, more preferably 2.0 or more, more preferably 3.0 or more, from the viewpoint of obtaining superior low-temperature fixability and heat-resistant storage stability. From the viewpoint of obtaining superior low-temperature fixability, it is preferably 40 or less, more preferably 35 or less, more preferably 20 or less, still more preferably 15 or less, still more preferably 10 or less, and still more preferably 8 or less.

[Content of Resin C]
The content of the resin C is 1% by mass or more and 25% by mass or less based on the total amount of the binder resin from the viewpoint of obtaining excellent low-temperature fixability and heat-resistant storage stability.
The content of the resin C is preferably 1% by mass or more, more preferably 3% by mass or more, more preferably 4% by mass or more, and still more preferably from the viewpoint of low-temperature fixability with respect to the total amount of the binder resin. From the viewpoint of improving low-temperature fixability and heat-resistant storage stability, it is preferably 25% by mass or less, more preferably 23% by mass or less, more preferably 20% by mass or less, and further preferably 15% by mass. It is at most 12% by mass, more preferably at most 12% by mass.

[Binder resin]
The binder resin of the toner of the present invention contains a crystalline resin (C). In addition, other resin may contain as binder resin, for example, the amorphous resin (A) etc. which are mentioned later may be contained.

<Crystalline resin (C)>
The crystalline resin (C) (hereinafter also simply referred to as “resin C”) has an alcohol component containing an aliphatic diol having 9 to 14 carbon atoms and a carbon number from the viewpoint of obtaining excellent low-temperature fixability and heat-resistant storage stability. It has at least a polyester moiety that is a polycondensate with a carboxylic acid component containing 9 or more and 14 or less aliphatic dicarboxylic acid compound.
“Crystalline resin” is defined by the ratio of the softening point (° C.) to the maximum endothermic peak temperature (° C.) by a differential scanning calorimeter (DSC), ie, [(softening point) / (maximum endothermic peak temperature)] The resin having a crystallinity index value of 0.6 or more and less than 1.4, preferably 0.8 or more and 1.2 or less. The maximum peak temperature of endotherm refers to the temperature of the peak on the highest temperature side among the endothermic peaks observed under the conditions of the measurement methods described in the examples.

  The resin C is, for example, a polyester or a composite resin having a polyester segment, and is preferably at least one selected from a polyester having the polyester part, a polyester segment having the polyester part, and a composite resin having a styrene resin segment.

(Alcohol component)
The alcohol component is an aliphatic diol having 9 to 14 carbon atoms from the viewpoint of obtaining excellent low-temperature fixability and heat-resistant storage stability.
The number of carbon atoms of the aliphatic diol is preferably 9 or more, more preferably 10 or more, more preferably 11 or more, and preferably 14 or less, more preferably from the viewpoint of improving low-temperature fixability and heat-resistant storage stability. 12 or less, and preferably 12.
The aliphatic diol may be a linear aliphatic diol or a branched aliphatic diol, but is preferably a linear aliphatic diol from the viewpoint of improving low-temperature fixability.

  Examples of the aliphatic diol include 1,10-decanediol and 1,12-dodecanediol. Among these, the aliphatic diol is preferably 1,12-dodecanediol.

  The content of the aliphatic diol in the alcohol component is preferably 70 mol% or more, more preferably 90 mol% or more, still more preferably 95 mol% or more, and further preferably 100 mol%.

(Carboxylic acid component)
The carboxylic acid component is an aliphatic dicarboxylic acid compound having 9 to 14 carbon atoms from the viewpoint of obtaining excellent low-temperature fixability and heat-resistant storage stability.
The number of carbon atoms of the aliphatic dicarboxylic acid is preferably 9 or more, more preferably 10 or more, more preferably 11 or more, and preferably 14 or less, more preferably, from the viewpoint of improving low-temperature fixability and heat-resistant storage stability. Is 12 or less, and is preferably 12.

  Examples of the aliphatic dicarboxylic acid include sebacic acid, dodecanedioic acid, anhydrides of these acids, and alkyl (1 to 3 carbon atoms) esters of these acids. These can be used alone or in combination of two or more. Among these, sebacic acid or dodecanedioic acid is preferable, and dodecanedioic acid is more preferable.

  The content of the aliphatic dicarboxylic acid in the carboxylic acid component is preferably 60 mol% or more, more preferably 70 mol% or more, still more preferably 80 mol% or more, still more preferably 90 mol% or more. From the viewpoint of fixability, it is 100 mol% or less.

The carboxylic acid component may preferably contain a trivalent or higher carboxylic acid from the viewpoint of productivity.
In addition, a monovalent alcohol may be appropriately contained in the alcohol component, and a monovalent carboxylic acid may be appropriately contained in the carboxylic acid component from the viewpoint of molecular weight adjustment.

  The equivalent ratio of the carboxylic acid component and the alcohol component (COOH group / OH group) is preferably 0.7 or more, more preferably 0.8 or more, and preferably 1.3 or less, more preferably from the viewpoint of adjusting the terminal group. 1.2 or less.

  The polycondensation of the alcohol component and the carboxylic acid component should be performed, for example, in an inert gas atmosphere at a temperature of about 180 ° C. to 250 ° C. in the presence of an esterification catalyst, a polymerization inhibitor, etc. Can do. Examples of the esterification catalyst include tin compounds such as dibutyltin oxide and tin (II) 2-ethylhexanoate, and titanium compounds such as titanium diisopropylate bistriethanolamate. Examples of the esterification cocatalyst that can be used together with the esterification catalyst include gallic acid and the like. The amount of esterification catalyst used is preferably 0.01 parts by mass or more, more preferably 0.1 parts by mass or more, and preferably 1 part by mass or less, more preferably 100 parts by mass of the total amount of alcohol component and carboxylic acid component. Preferably it is 0.6 mass part or less. The amount of 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 of the total amount of the alcohol component and the carboxylic acid component. More preferably, it is 0.1 parts by mass or less.

[Composite resin]
The composite resin preferably has a polyester segment and a styrene resin segment.
The polyester segment is made of polyester, and preferred examples of the polyester are the same as those described above.

(Styrene resin segment)
The styrene resin segment is made of a styrene resin, and the styrene resin is preferably an addition polymer of a raw material monomer containing a styrene compound.
Examples of the styrene compound include styrene, styrene derivatives such as α-methylstyrene and vinyltoluene (hereinafter, styrene and styrene derivatives are collectively referred to as “styrene compound”).

  The content of the styrene compound is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and further preferably 75% by mass in the raw material monomer of the styrene resin, from the viewpoint of heat-resistant storage stability. It is above and is 100 mass% or less.

  As raw material monomers for styrene resins used in addition to styrene compounds, (meth) acrylic acid alkyl esters; ethylenically unsaturated monoolefins such as ethylene and propylene; diolefins such as butadiene; halovinyls such as vinyl chloride; Examples thereof include vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as vinyl methyl ether; vinylidene halides such as vinylidene chloride; N-vinyl compounds such as N-vinyl pyrrolidone and the like.

  Two or more kinds of raw material monomers for the styrene resin used in addition to the styrene compound can be used. In the present specification, “(meth) acrylic acid” means at least one selected from acrylic acid and methacrylic acid.

  Among the raw material monomers for styrene resins used other than styrene compounds, (meth) acrylic acid alkyl esters are preferred from the viewpoint of improving the low-temperature fixability of the toner. In view of the above, the carbon number of the alkyl group in the (meth) acrylic acid alkyl ester is preferably 1 or more, more preferably 2 or more, more preferably 3 or more, and preferably 22 or less, more preferably 18 or less. More preferably, it is 12 or less, more preferably 8 or less. In addition, carbon number of this alkyl ester means carbon number derived from the alcohol component which comprises ester.

  Specific examples of (meth) acrylic acid alkyl esters include methyl (meth) acrylate, ethyl (meth) acrylate, (iso) propyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, (iso or tertiary ) Butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (iso) octyl (meth) acrylate, (iso) decyl (meth) acrylate, (iso) stearyl (meth) acrylate, and the like. Here, `` (iso or tertiary) '' and `` (iso) '' mean both when these prefixes are present and when they are not, and when these prefixes are not present Indicates normal. Further, “(meth) acrylate” means at least one selected from acrylate and methacrylate.

  The content of the (meth) acrylic acid alkyl ester is preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less, from the viewpoint of low-temperature fixability in the raw material monomer of the styrene resin segment. More preferably, it is 25% by mass or less, and preferably 0% by mass or more.

  A resin obtained by addition polymerization of a raw material monomer containing a styrene compound and a (meth) acrylic acid alkyl ester is also referred to as a styrene- (meth) acrylic resin.

  The addition polymerization reaction of the raw material monomer of the styrenic resin can be carried out in a conventional manner, for example, in the presence of a polymerization initiator such as dicumyl peroxide, a crosslinking agent, etc., in the presence of an organic solvent, or in the absence of a solvent. The temperature condition is preferably 110 ° C or higher, more preferably 120 ° C or higher, more preferably 130 ° C or higher, and preferably 250 ° C or lower, more preferably 230 ° C or lower, more preferably 200 ° C or lower. .

  When an organic solvent is used in the addition polymerization reaction, xylene, toluene, methyl ethyl ketone, acetone or the like 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 of the styrene resin.

(Amotropic monomer)
From the viewpoint of improving low-temperature fixability and heat-resistant storage stability, the composite resin is used in addition to the polyester segment raw material monomer and the styrene resin segment raw material monomer, as well as the polyester segment raw material monomer and the styrene resin segment raw material monomer. It is preferably a composite resin obtained by using a bireactive monomer that can react with both. Therefore, when the raw material monomer for the polyester segment and the raw material monomer for the styrene resin segment are polymerized to obtain a composite resin, the polycondensation reaction and / or the addition polymerization reaction are preferably performed in the presence of both reactive monomers. Thereby, the composite resin becomes a composite resin in which the polyester segment and the styrenic resin segment are bonded via the structural unit derived from the both reactive monomers, and the polyester segment and the styrenic resin segment are more finely and uniformly. It will be distributed.

  That is, from the viewpoint of improving low-temperature fixability and heat-resistant storage stability, the composite resin comprises (i) an alcohol component containing an aliphatic diol having 9 to 14 carbon atoms and an aliphatic dicarboxylic acid having 9 to 14 carbon atoms. It reacts with any of the raw material monomer of the polyester segment containing the carboxylic acid component containing the compound, (ii) the raw material monomer of the styrene resin segment, and (iii) the raw material monomer of the polyester segment and the raw material monomer of the styrene resin segment. A resin obtained by polymerizing the obtained both reactive monomers is preferred.

  As the both reactive monomers, at least one functional group selected from a hydroxyl group, a carboxy group, an epoxy group, a primary amino group and a secondary amino group in the molecule, preferably at least selected from a hydroxyl group and a carboxy group. A compound having one kind of functional group, more preferably a carboxy group and an ethylenically unsaturated bond is preferred, and by using such a bireactive monomer, the dispersibility of the resin as the dispersed phase can be further improved. it can. The both reactive monomers are preferably at least one selected from acrylic acid, methacrylic acid, fumaric acid, maleic acid and maleic anhydride. From the viewpoint of the reactivity of polycondensation reaction and addition polymerization reaction, acrylic acid is preferred. Methacrylic acid or fumaric acid is more preferable, and acrylic acid or methacrylic acid is still more preferable. However, when used together with a polymerization inhibitor, a polyvalent carboxylic acid having an ethylenically unsaturated bond such as fumaric acid functions as a raw material monomer for the polyester segment. In this case, fumaric acid or the like is not a bireactive monomer but a raw material monomer for the polyester segment.

  From the viewpoint of low-temperature fixability, the amount of both reactive monomers used is preferably 1 mol or more, more preferably 2 mol or more, and still more preferably 3 mol or more with respect to a total of 100 mol of the alcohol component of the polyester segment. From the viewpoint of heat resistant storage stability of the toner, it is preferably 20 mol or less, more preferably 10 mol or less, and still more preferably 7 mol or less.

  The mass ratio of the polyester segment to the styrene resin segment (polyester segment / styrene resin segment) in the composite resin is preferably 60/40 or more, more preferably 70/30 or more, and still more preferably, from the viewpoint of low-temperature fixability. From the viewpoint of heat-resistant storage stability, it is preferably 95/5 or less, more preferably 90/10 or less, and still more preferably 85/15 or less. In the above calculation, the mass of the polyester segment is the amount obtained by subtracting the amount (calculated value) of the reaction water dehydrated by the polycondensation reaction from the mass of the raw material monomer of the polycondensation resin used. The amount of the monomer is included in the amount of the raw material monomer of the polyester segment. The amount of the styrene resin segment is the amount of the raw material monomer of the styrene resin segment, and the amount of the polymerization initiator is not included in the amount of the raw material monomer of the styrene resin segment.

[Physical properties and content of resin C]
The melting point of the resin C is preferably 65 ° C. or higher, more preferably 70 ° C. or higher, still more preferably 75 ° C. or higher, further preferably 80 ° C. or higher, from the viewpoint of low-temperature fixability. Is 150 ° C. or lower, more preferably 135 ° C. or lower, and still more preferably 120 ° C. or lower.

  The softening point of the resin C is preferably 75 ° C. or higher, more preferably 80 ° C. or higher, still more preferably 85 ° C. or higher, further preferably 90 ° C. or higher, from the viewpoint of low-temperature fixability. Preferably it is 150 degrees C or less, More preferably, it is 140 degrees C or less, More preferably, it is 120 degrees C or less, More preferably, it is 100 degrees C or less.

  The acid value of Resin C is preferably 40 mgKOH / g or less, more preferably 30 mgKOH / g or less, still more preferably 20 mgKOH / g or less, and preferably 1 mgKOH / g from the viewpoint of improving the heat-resistant storage stability of the toner. Above, more preferably 2 mgKOH / g or more.

  The content of the resin C is as described above.

<Amorphous resin (A)>
The toner of the present invention preferably contains an amorphous resin (A) (hereinafter also simply referred to as “resin A”) as a binder resin.
In the present invention, the “amorphous resin” refers to a resin having a crystallinity index value of 1.4 or more or less than 0.6.

The resin A preferably has at least a polyester portion obtained by polycondensation of an alcohol component and a carboxylic acid compound.
Examples of the resin A include polyester and a composite resin having a polyester segment. Preferably, the resin A is at least one selected from polyester and a composite resin having a polyester segment and a styrene resin segment.
Hereinafter, as a preferred embodiment of the resin A, the description of portions common to the illustration in the resin C will be omitted, and only a preferred embodiment as the embodiment of the resin A will be described.

(Alcohol component)
The alcohol component may be an aromatic polyol compound or an aliphatic polyol compound.
The alcohol component of the resin A preferably contains an aromatic polyol compound from the viewpoint of improving low temperature fixability and heat resistant storage stability.
The aromatic polyol compound is preferably an alkylene oxide adduct of bisphenol A, more preferably a compound represented by formula (I):

[Wherein, RO and OR are oxyalkylene groups, R is at least one selected from an ethylene group and a propylene group, and x and y represent the average number of moles of alkylene oxide added, each being 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 4 or less. An alkylene oxide adduct of bisphenol A represented by the formula:

  Examples of the alkylene oxide adduct of bisphenol A represented by the formula (I) include 2,2-bis (4-hydroxyphenyl) propane propylene oxide adduct, 2,2-bis (4-hydroxyphenyl) propane ethylene. And oxide adducts. It is preferable to use one or more of these.

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

The alcohol component of the resin A may contain an aliphatic polyol compound.
Examples of the aliphatic polyol compound include aliphatic diols having 2 to 20 carbon atoms and trihydric or higher aliphatic alcohols such as glycerin.
Aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-butenediol 1,3-butanediol, neopentyl glycol, 1,10-decanediol, 1,12-dodecanediol and the like.

  The content of the aliphatic diol in the alcohol component is preferably 30 mol% or less, more preferably 20 mol% or less, still more preferably 10 mol% or less, still more preferably 5 mol% or less, and 0 mol%. That's it.

(Carboxylic acid component)
The carboxylic acid component of the resin A preferably contains an aromatic dicarboxylic acid from the viewpoint of heat resistant storage stability, and may further contain an aliphatic dicarboxylic acid in addition to the aromatic dicarboxylic acid.
The content of the aromatic dicarboxylic acid in the carboxylic acid component is preferably 40 mol% or more, more preferably 45 mol% or more, still more preferably 50 mol% or more, and 100 mol% or less.

The aliphatic dicarboxylic acid is preferably substituted with an alkyl group having 1 to 20 carbon atoms (preferably 10 to 16 carbon atoms) or an alkenyl group having 2 to 20 carbon atoms (preferably 10 to 16 carbon atoms). Aliphatic dicarboxylic acids such as succinic acid, or adipic acid, more preferably dodecenyl succinic acid or adipic acid.
The content of the aliphatic dicarboxylic acid is preferably 3 mol% or more, more preferably 8 mol% or more, still more preferably 10 mol% or more, and preferably 40 mol% or less, more preferably in the carboxylic acid component. Is 30 mol% or less, more preferably 25 mol% or less.

  The carboxylic acid component preferably contains a trivalent or higher carboxylic acid, and more preferably contains a trivalent carboxylic acid, from the viewpoint of heat-resistant storage stability.

  The trivalent or higher carboxylic acids include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 2,5,7-naphthalenetricarboxylic acid, pyromellitic acid or acid anhydrides thereof, lower alkyl (1 carbon number) -3) Esters and the like. Among these, trimellitic acid is preferable.

  The content of carboxylic acid having a valence of 3 or more, preferably the content of trimellitic acid is preferably 1 mol% or more, more preferably 3 mol% or more, further preferably 5 mol% or more in the carboxylic acid component, From the viewpoint of low-temperature fixability, it is preferably 30 mol% or less, more preferably 25 mol% or less, and still more preferably 20 mol% or less.

[Composite resin]
The composite resin as the resin A preferably has a polyester segment and a styrene resin segment. The polyester segment is made of polyester, and preferred examples of the polyester include those similar to the polyester of resin A.

(Styrene resin segment)
The content of the styrene compound is preferably 50% by mass or more, more preferably 60% by mass or more, still more preferably 70% by mass or more, and further preferably 75% by mass or more, in the raw material monomer of the styrene resin. From this viewpoint, it is preferably 95% by mass or less, more preferably 90% by mass or less, and still more preferably 87% by mass or less.
The content of the (meth) acrylic acid alkyl ester is preferably 5% by mass or more, more preferably 10% by mass or more, and further preferably 13% by mass or more from the viewpoint of low-temperature fixability in the raw material monomer of the styrene resin segment. From the same viewpoint, it is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, and further preferably 25% by mass or less.

[Physical properties and content of resin A]
The glass transition temperature of the resin A is preferably 45 ° C. or higher, more preferably 50 ° C. or higher, and still more preferably 55 ° C. or higher from the viewpoint of improving the heat resistant storage stability, and the viewpoint of improving the low temperature fixability of the toner. Therefore, it is preferably 80 ° C. or lower, more preferably 75 ° C. or lower, more preferably 70 ° C. or lower, and further preferably 65 ° C. or lower.

  The softening point of the resin A is preferably 80 ° C. or higher, more preferably 95 ° C. or higher, still more preferably 100 ° C. or higher, from the viewpoint of low-temperature fixability, and from the same viewpoint, preferably 160 ° C. or lower, more Preferably it is 150 degrees C or less, More preferably, it is 140 degrees C or less.

  The acid value of the resin A is preferably 40 mgKOH / g or less, more preferably 30 mgKOH / g or less, still more preferably 20 mgKOH / g or less, and preferably 1 mgKOH / g or more, from the viewpoint of improving the heat resistant storage stability. More preferably, it is 2 mgKOH / g or more.

  The content of the resin A is preferably 70% by mass or more, more preferably 75% by mass or more, and still more preferably 83% from the viewpoint of improving low-temperature fixability and heat-resistant storage stability with respect to the total amount of the binder resin. From the viewpoint of low-temperature fixability, it is preferably 99% by mass or less, more preferably 97% by mass or less, and still more preferably 93% by mass or less.

[Ester wax (W)]
The ester wax (W) is an aliphatic carboxylic acid ester of 14 to 24 carbon atoms of dipentaerythritol from the viewpoint of obtaining an electrophotographic toner excellent in low-temperature fixability and heat-resistant storage stability.
In the ester wax (W), the number of ester substitutions of dipentaerythritol with a fatty acid is preferably 4 or more, more preferably 5 or more, and 6 or less from the viewpoint of improving low-temperature fixability and heat-resistant storage stability. Yes, and 6.

The aliphatic carboxylic acid that is a constituent of the ester wax (W) may be a linear aliphatic carboxylic acid or a branched aliphatic carboxylic acid, but is preferably a linear aliphatic carboxylic acid. .
As a constituent component of the ester wax (W), the aliphatic carboxylic acid preferably has 14 or more carbon atoms, more preferably 16 or more carbon atoms, and preferably 24 or less, more preferably 20 or less.

  As the constituent component of the ester wax (W), examples of the aliphatic carboxylic acid include myristic acid, palmitic acid, stearic acid, oleic acid, icosanoic acid, behenic acid, and tetracosanoic acid. These may be one type or two or more types. Among these, at least one selected from palmitic acid, stearic acid, and behenic acid is preferable.

The melting point of the ester wax (W) is preferably 60 ° C. or higher, more preferably 65 ° C. or higher from the viewpoint of heat-resistant storage stability, and preferably 150 ° C. or lower, more preferably 135 ° C. from the viewpoint of low-temperature fixability. ° C or lower, more preferably 120 ° C or lower, more preferably 100 ° C or lower.
The melting point of the ester wax (W) is measured by the method described in the examples.

  The content of the ester wax (W) is preferably 0.3 parts by mass or more, more preferably 0.8 parts by mass or more, and still more preferably 1.0 parts by mass, from the viewpoint of low-temperature fixability with respect to 100 parts by mass of the total amount of the binder resin. Part or more, more preferably 2.0 parts by weight or more, and from the viewpoint of improving low-temperature fixability and heat-resistant storage stability, preferably 30 parts by weight or less, more preferably 20 parts by weight or less, still more preferably 10 parts by weight. Hereinafter, it is further preferably 5 parts by mass or less, and more preferably 3 parts by mass or less.

[Other release agents]
The toner of the present invention may contain a release agent in addition to the ester wax (W) as long as the effects of the present invention are not impaired.
Examples of mold release agents include polypropylene wax, polyethylene wax, polypropylene polyethylene copolymer wax; hydrocarbon wax such as microcrystalline wax, paraffin wax, Fischer-Tropsch wax, sazol wax, or oxides thereof; carnauba wax, montan Ester waxes such as fatty acid ester waxes other than waxes or their deoxidized waxes and ester waxes (W); fatty acid amides, fatty acids, higher alcohols, fatty acid metal salts, and the like. The above can be used.

  The melting point of the release agent is preferably 60 ° C. or more, more preferably 70 ° C. or more from the viewpoint of heat-resistant storage stability, and preferably 160 ° C. or less, more preferably 150 ° C. or less from the viewpoint of low-temperature fixability. More preferably, it is 140 ° C. or lower.

  The content of the other release agent is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, and still more preferably from the viewpoint of dispersibility in the binder resin with respect to 100 parts by mass of the binder resin. 3 parts by mass or less, and 0 parts by mass or more, preferably 0.5 parts by mass or more.

[Charge control agent]
The toner of the present invention may contain a charge control agent.
The charge control agent is not particularly limited, and may contain either a positively chargeable charge control agent or a negatively chargeable charge control agent.
Examples of positively chargeable charge control agents include nigrosine dyes such as “Nigrosine Base EX”, “Oil Black BS”, “Oil Black SO”, “Bontron N-01”, “Bontron N-04”, “Bontron N-07 ”,“ Bontron N-09 ”,“ Bontron N-11 ”(manufactured by Orient Chemical Co., Ltd.) and the like; 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), etc .; polyamine resin such as" AFP-B "(manufactured by Orient Chemical Industry Co., Ltd.) Imidazole derivatives such as “PLZ-2001” and “PLZ-8001” (manufactured by Shikoku Kasei Kogyo Co., Ltd.); styrene-acrylic resins such as “FCA-701PT” (Fujikura Chemical) Etc., Ltd.) Co., Ltd., and the like.

In addition, as the negatively chargeable charge control agent, metal-containing azo dyes such as “Varifast Black 3804”, “Bontron S-31”, “Bontron S-32”, “Bontron S-34”, “Bontron S-36” (Above, made by Orient Chemical Co., Ltd.), “Eisenspiron Black TRH”, “T-77” (made by Hodogaya Chemical Co., Ltd.), etc .; metal compounds of benzylic 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" (made by Orient Chemical Co., Ltd.), "TN-105" (made by Hodogaya Chemical Co., Ltd.), etc .; copper phthalocyanine dyes; quaternary ammonium salts such as "COPY CHARGE NX VP434" (made by Clariant) Nitroimidazole derivatives Etc .; organometallic compounds and the like.
Among charge control agents, negatively chargeable charge control agents are preferable, and metal compounds of salicylic acid compounds are more preferable.

  The content of the charge control agent is preferably 0.01 parts by mass or more, more preferably 0.2 parts by mass or more, and preferably 10 parts by mass or less, more preferably 5 parts by mass with respect to 100 parts by mass of the binder resin. Hereinafter, it is more preferably 3 parts by mass or less, and further preferably 2 parts by mass or less.

[Colorant]
The toner of the present invention may contain a colorant.
As the colorant, all of dyes and pigments used as toner colorants can be used, such as carbon black, phthalocyanine blue, permanent brown FG, brilliant first scarlet, pigment green B, rhodamine-B base, Solvent Red 49, Solvent Red 146, Solvent Blue 35, Quinacridone, Carmine 6B, Disazo Yellow and the like can be used, and the toner of the present invention may be either a black toner or a color toner.

  The content of the colorant is preferably 1 part by mass or more, more preferably 2 parts by mass or more, and preferably 40 parts by mass with respect to 100 parts by mass of the binder resin from the viewpoint of improving the image density of the toner. Part or less, more preferably 20 parts by weight or less, still more preferably 10 parts by weight or less.

  In the toner of the present invention, additives such as magnetic powders, fluidity improvers, conductivity modifiers, reinforcing fillers such as fibrous substances, antioxidants, anti-aging agents, and cleaning improvers are appropriately used. It may be.

(External additive)
The toner of the present invention may be subjected to surface treatment of toner base particles using an external additive.
Examples of the external additive include hydrophobic silica, titanium oxide fine particles, alumina fine particles, cerium oxide fine particles, inorganic fine particles such as carbon black, and polymer fine particles such as polycarbonate, polymethyl methacrylate, and silicone resin. Among these, Hydrophobic silica is preferred.
When the surface treatment of the toner base particles is performed using an external additive, the amount of the external additive added is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, and more preferably 100 parts by mass of the toner base particles. The amount is preferably 1.0 part by mass or more, and preferably 5 parts by mass or less, more preferably 4 parts by mass or less, and further preferably 3 parts by mass or less.

[Production method]
As a method for producing the electrophotographic toner of the present invention,
(1) A method for producing a toner by melt-kneading a mixture containing a binder resin and pulverizing the obtained melt-kneaded product (hereinafter also referred to as “melt-kneading method”),
(2) A method for producing a toner by obtaining toner particles by aggregating and fusing the binder resin particles in a mixture containing a dispersion in which the binder resin is dispersed in an aqueous medium (hereinafter referred to as “aggregation”). And fusion method)),
(3) A method for producing toner by, for example, obtaining toner particles by rapidly stirring a dispersion obtained by dispersing a binder resin in a water-soluble medium and a raw material for toner.
From the viewpoint of improving the productivity of the toner and the viewpoint of improving the fixing property of the toner, the melt kneading method (1) is preferable. Further, the toner may be obtained by the aggregation and fusion method (2).

  In the case of producing the toner by any of the above methods, the amount of the binder resin used is preferably 5% by mass or more from the viewpoint of improving low-temperature fixability and heat-resistant storage stability with respect to the toner base particles. More preferably 30% by mass or more, more preferably 50% by mass or more, more preferably 70% by mass or more, more preferably 80% by mass or more, more preferably 90% by mass or more, and 100% by mass or less. More preferably, it is 99 mass% or less.

(1) Melt-kneading method The method of (1) preferably includes the following steps 1-1 and 1-2.
Step 1-1: Step of melt-kneading a mixture containing the crystalline resin (C) and ester wax (W) Step 1-2: Grind and classify the melt-kneaded product obtained in Step 1-1 Process

<Process 1-1>
In Step 1-1, it is preferable that the colorant is further melt-kneaded, and other additives such as a release agent and a charge control agent are preferably melt-kneaded together.

  The melt-kneading can be performed using a known kneader such as a closed kneader, a single-screw extruder, a twin-screw extruder, or an open roll kneader. From the viewpoint of melting and mixing the crystals, a twin screw extruder that can be set to high temperature conditions is preferable.

  The toner raw materials such as the binder resin, the colorant, the charge control agent, and the release agent are preferably mixed in advance with a mixer such as a Henschel mixer or a ball mill and then supplied to the kneader.

  The twin-screw extruder has a kneading part sealed, and can easily melt each material by kneading heat generated during kneading.

The set temperature of the twin-screw extruder is not affected by the melting characteristics of the material due to the structure of the extruder, and can be easily melt-mixed at the intended temperature.
The set temperature (barrel set temperature) of the twin-screw extruder is appropriately set so that the temperature _Kt falls within a predetermined range, for example, preferably 80 ° C or higher, more preferably 90 ° C or higher, and Preferably it is 160 degrees C or less, More preferably, it is 140 degrees C or less.

  Rotational peripheral speed is the same direction from the viewpoint of improving the dispersibility of additives such as colorants, charge control agents, and release agents in the toner, reducing the mechanical force during melt kneading, and suppressing heat generation. In the case of a rotary twin screw extruder, it is preferably 5 m / min or more, more preferably 10 m / min or more, more preferably 15 m / min or more, and preferably 50 m / min or less, more preferably 40 m / min or less. More preferably, it is 30 m / min or less.

  The melt-kneaded product obtained in step 1-1 is cooled to such an extent that it can be pulverized, and then subjected to subsequent step 1-2.

<Process 1-2>
In step 1-2, the melt-kneaded product obtained in step 1-1 is pulverized and classified.

  The pulverization process may be performed in multiple stages. For example, a resin kneaded product obtained by curing a melt-kneaded product may be coarsely pulverized to about 1 to 5 mm and further pulverized to a desired particle size.

  The pulverizer used in the pulverization step is not particularly limited, and examples of the pulverizer suitably used for coarse pulverization include a hammer mill, an atomizer, and a rotplex. Further, examples of the pulverizer suitably used for fine pulverization include a fluidized bed jet mill, a collision plate jet mill, and a rotary mechanical mill. From the viewpoint of pulverization efficiency, it is preferable to use a fluidized bed jet mill and a collision plate jet mill, and more preferably a fluidized bed jet mill.

  Examples of the classifier used in the classification process include a rotor classifier, an airflow classifier, an inertia classifier, and a sieve classifier. In the classification step, the pulverized product that has been 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.

The volume median particle size (D ₅₀ ) of the toner base particles obtained by this step is preferably 2 μm or more, more preferably 3 μm or more, more preferably 4 μm or more, and preferably 20 μm or less, more preferably It is 15 μm or less, more preferably 10 μm or less.

(2) Aggregation and fusion method (2)
Step 2-1: Step of obtaining an aqueous dispersion containing the crystalline resin (C),
Step 2-2: A step of obtaining an aqueous dispersion containing ester wax (W), and Step 2-3: An aqueous dispersion obtained in Step 2-1, and an aqueous dispersion obtained in Step 2-2. And mixing and fusing the binder resin in the resulting mixed liquid.

  In the present invention, the term “aqueous” may contain a solvent such as an organic solvent, but water is preferably 50% by mass or more, more preferably 70% by mass or more, and still more preferably 90% by mass in the solvent. The content above is preferably 100% by mass or less.

<Process 2-1>
In Step 2-1, an aqueous dispersion containing a crystalline resin (C) is obtained. When the electrophotographic toner contains an amorphous resin (A) as a binder resin, an amorphous resin is obtained by the following method. An aqueous dispersion containing a porous resin (A) is prepared.
Hereinafter, “crystalline resin (C)” and “amorphous resin (A)” are collectively referred to as “binder resin”, and this step will be described.

  The aqueous dispersion containing the binder resin is mixed with each binder resin, an organic solvent and water, and further, if necessary, a neutralizing agent and a surfactant, and after stirring, the organic solvent is removed by distillation or the like. Can be obtained. In addition, when stirring the mixture, commonly used mixing and stirring devices such as anchor blades, Despa (manufactured by Asada Tekko Co., Ltd.), TK homomixer, TK homodisper, TK Robomix (all of which are Primix Co., Ltd.) ), CLEARMIX (M Technique Co., Ltd.), KD Mill (KAD International Co., Ltd.), and the like.

  Examples of the organic solvent include alcohol solvents such as ethanol, isopropanol and isobutanol; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone and diethyl ketone; ether solvents such as dibutyl ether, tetrahydrofuran and dioxane; ethyl acetate, chloroform, Examples include dichloroethane. Among these, chloroform and ethyl acetate are preferable from the viewpoint of improving the dispersibility of the binder resin.

  Examples of the neutralizing agent include alkali metals such as lithium hydroxide, sodium hydroxide and potassium hydroxide; organic bases such as ammonia, trimethylamine, ethylamine, diethylamine, triethylamine, triethanolamine and tributylamine.

  Examples of the surfactant include an anionic surfactant, a cationic surfactant, a nonionic surfactant, and the like, and an anionic surfactant is preferable.

  Examples of the anionic surfactant include alkylbenzene sulfonate, alkyl sulfate, alkyl ether sulfate, and polyoxyalkylene alkyl ether sulfate. From the viewpoint of improving the dispersion stability of the dispersion of resin particles, alkylbenzene is used. Sulfonates and alkyl ether sulfates are preferred. Specifically, sodium dodecylbenzenesulfonate, sodium dodecyl sulfate, sodium dodecyl ether sulfate and sodium polyoxyethylene lauryl ether sulfate are more preferable.

  Examples of the cationic surfactant include alkylbenzene trimethylammonium chloride, alkyltrimethylammonium chloride, and dialkyldimethylammonium chloride.

  Examples of nonionic surfactants include polyoxyethylene aryl ethers, polyoxyethylene alkyl ethers, polyoxyethylene sorbbutane esters, polyoxyethylene fatty acid esters, oxyethylene / oxypropylene block copolymers, and the like.

  When using a surfactant, the amount used is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass or more, with respect to 100 parts by mass of the binder resin in the case of preparing an aqueous dispersion of the binder resin. And preferably 30 parts by mass or less, more preferably 20 parts by mass or less.

  In the case of preparing an aqueous dispersion of the binder resin, the amount of the organic solvent used when mixing with the binder resin is preferably 30 parts by mass or more, more preferably 50 parts by mass with respect to 100 parts by mass of the binder resin. Part or more, and preferably 1500 parts by weight or less, more preferably 1000 parts by weight or less.

  The temperature when mixing (dissolving) the binder resin with the organic solvent depends on the boiling point of the organic solvent used, but is preferably 10 ° C or higher, more preferably 20 ° C or higher, and preferably 90 ° C or lower. More preferably, it is 80 ° C. or lower.

  The solid concentration of the aqueous dispersion containing the binder resin can be adjusted by appropriately adding water, but is preferably 3% by mass or more, more preferably 5% by mass or more, and further preferably 10% by mass or more. And, it is preferably 30% by mass or less, more preferably 25% by mass or less.

  Moreover, it can also be set as a dispersion liquid by mixing with a nonionic surfactant, without using the said organic solvent.

  Examples of the nonionic surfactant include polyoxyethylene alkyl aryl ethers such as polyoxyethylene nonylphenyl ether; polyoxyethylene alkyl ethers such as polyoxyethylene oleyl ether and polyoxyethylene lauryl ether; polyoxyethylene Sorbitan laurate and polyoxyethylene sorbitan esters such as polyoxyethylene sorbitan monostearate; polyoxyethylene fatty acid esters such as polyethylene glycol monolaurate, polyethylene glycol monostearate and polyethylene glycol monooleate; oxy Examples include ethylene / oxypropylene block copolymers. In addition, an anionic surfactant or a cationic surfactant may be used in combination with the nonionic surfactant.

  The clouding point of the nonionic surfactant is preferably 70 ° C. or higher, more preferably 80 ° C. or higher, and preferably 105 ° C. or lower, more preferably when the resin is atomized under normal pressure and water. Is below 100 ° C.

  The amount of the nonionic surfactant used is preferably 5 parts by mass or more, more preferably from 100 parts by mass of the binder resin, from the viewpoint of improving the dispersion stability of the binder resin particles in the aqueous dispersion. It is 10 parts by mass or more, more preferably 20 parts by mass or more, and preferably 80 parts by mass or less, more preferably 70 parts by mass or less, and further preferably 60 parts by mass or less.

The volume median particle size (D ₅₀ ) of the binder resin particles in the aqueous dispersion containing the binder resin is preferably 50 nm or more, more preferably 80 nm or more, from the viewpoint of uniformly agglomerating in the next step 2-2. And preferably 1000 nm or less, more preferably 500 nm or less, and still more preferably 300 nm or less. The volume median particle size (D ₅₀ ) of each particle can be measured with a laser diffraction type particle size measuring machine or the like.

<Process 2-2>
The aqueous dispersion containing the ester wax (W) disperses the ester wax (W) and the aqueous medium using a disperser at a temperature equal to or higher than the melting point of the ester wax (W) in the presence of a surfactant or the like. It is preferable to obtain by this. As the disperser, a homogenizer, an ultrasonic disperser or the like is preferable.
Examples of the ultrasonic disperser include an ultrasonic homogenizer. Commercially available products include “US-150T”, “US-300T”, “US-600T” (manufactured by Nippon Seiki Seisakusho Co., Ltd.), “SONIFIER 4020-400”, “SONIFIER 4020-800” (manufactured by Branson) Etc.
The preferred embodiment of the aqueous medium used in the production is the same as that used when obtaining the aqueous dispersion of the crystalline resin (C).

A dispersant may be used for dispersing the ester wax (W).
Examples of the dispersant include nonionic surfactants, anionic surfactants, cationic surfactants, and the like, and those similar to those used for the production of the crystalline resin (C) can be used.
As the dispersant for the ester wax (W), an anionic surfactant is preferable, and a polycarboxylate is more preferable.
Examples of the polycarboxylate include polyacrylate, salt of acrylic acid-maleic acid copolymer, polymaleate, and the like. Among these, an acrylic acid-maleic acid copolymer salt is preferable.
As the salt, an alkali metal salt is preferable, and a sodium salt is more preferable.
The weight average molecular weight of the polycarboxylate is preferably 90,000 or less, more preferably 50,000 or less, and preferably 3,000 or more, more preferably 10,000 or more.
As commercially available products of polycarboxylates, “Poise 530” (sodium polyacrylate aqueous solution, weight average molecular weight 38,000) manufactured by Kao Corporation, “Poise 521” (sodium acrylate-sodium maleate copolymer aqueous solution, weight) Average molecular weight 20,000).

The content of the dispersant in the aqueous dispersion is preferably 15 parts by mass or less, more preferably 10 parts by mass or less, still more preferably 5.0 parts by mass or less with respect to 100 parts by mass of the ester wax (W). Preferably it is 0.2 mass part or more, More preferably, it is 1.0 mass part or more, More preferably, it is 2.0 mass part or more.
The volume median particle size (D ₅₀ ) of the ester wax (W) is preferably 100 nm or more, more preferably 200 nm or more, and preferably 1 μm or less, more preferably 700 nm or less, and even more preferably 600 nm or less. .

<Process 2-3>
Step 2-3 is the addition of the aqueous dispersion obtained in Step 2-1, the aqueous dispersion obtained in Step 2-2, and additives such as colorants, other release agents, and charge control agents. Then, you may attach | subject to an aggregation process. The additive can also be used as an aqueous dispersion.

  In step 2-3, the softening point of the polyester having the lowest softening point is preferable from the viewpoint of uniformly dispersing the mixture of the aqueous dispersion containing the binder resin and various additives used as necessary. The dispersion treatment is carried out at a temperature lower than or equal to the temperature below, more preferably “the softening point−20 ° C.” (meaning a temperature 20 ° C. lower than the softening point, the same applies hereinafter). Specifically, it is preferably 60 ° C. or lower, more preferably 55 ° C. or lower, and the dispersion treatment should be performed at a temperature higher than 0 ° C. from the viewpoint of fluidity of the medium and production energy of the aqueous dispersion of the resin. It is preferable to carry out at 10 ° C. or higher.

  From these viewpoints, it is preferably 0 ° C. or higher, more preferably 10 ° C. or higher, and preferably 60 ° C. or lower, more preferably 55 ° C. or lower by a usual method such as stirring and dispersing. A uniform resin dispersion can be prepared.

  As a dispersion treatment method, it is preferable to disperse using a disperser. As a disperser to be used, a commonly used mixing and stirring device such as an anchor blade, Despa (manufactured by Asada Tekko Co., Ltd.), TK homomixer, TK homodispers, TK Robomix (all of which are manufactured by PRIMIX Co., Ltd.), CLEARMIX (manufactured by M Technique Co., Ltd.), KD Mill (manufactured by KD International Co., Ltd.), etc., ultrasonic dispersers, etc. Can be mentioned.

  The pH in the system in the aggregation step is preferably 2 or more, more preferably 3 or more, and preferably 10 or less, more preferably, from the viewpoint of achieving both the dispersion stability of the mixed solution and the aggregation properties of the resin particles. Is 9 or less, more preferably 8 or less.

  The temperature in the system in the agglomeration process is equal to or higher than “softening point of polyester having the lowest softening point—70 ° C.” or more from the viewpoint of achieving both the dispersion stability of the mixed solution and the cohesiveness of the resin particles. It is preferable that it is below the softening point of polyester with a point.

  In the aggregation process, an aggregating agent can be added in order to effectively perform aggregation. As an aggregating agent, a quaternary salt cationic surfactant, polyethyleneimine, or the like is used in an organic system, and an inorganic metal salt, an inorganic ammonium salt, a divalent or higher-valent metal complex, or the like is used in an inorganic system.

  Examples of the inorganic metal salt include metal salts such as sodium sulfate, sodium chloride, calcium chloride, calcium nitrate, barium chloride, magnesium chloride, zinc chloride, aluminum chloride, and aluminum sulfate; polyaluminum chloride, polyaluminum hydroxide, and Examples thereof include inorganic metal salt polymers such as calcium polysulfide. Examples of the inorganic ammonium salt include ammonium sulfate, ammonium chloride, and ammonium nitrate. Among these, calcium chloride is preferable from the viewpoint of achieving both the dispersion stability of the mixed solution and the cohesiveness of the resin particles.

  When adding a flocculant, the amount added is preferably 0.1 parts by mass or more, more preferably 100 parts by mass with respect to 100 parts by mass of the binder resin from the viewpoint of controlling the cohesiveness of the resin particles to obtain a desired particle size. It is 0.2 parts by mass or more, preferably 60 parts by mass or less, more preferably 55 parts by mass or less, and still more preferably 50 parts by mass or less.

  The flocculant is preferably added after being dissolved in an aqueous medium, and it is preferable that the flocculant is sufficiently stirred at the time of addition of the flocculant and after completion of the addition.

The volume median particle size (D ₅₀ ) of the aggregated particles obtained in the aggregation process is preferably 1 μm or more, more preferably 2 μm or more, and even more preferably 3 μm or more, from the viewpoint of producing toner particles by uniformly fusing. And preferably 15 μm or less, more preferably 10 μm or less.

  In the aggregation step, an aggregation stopper is added as necessary, and then subjected to the fusion step to obtain an aqueous dispersion of fused particles. As the aggregation terminator, a surfactant is preferably used, and an anionic surfactant is more preferably used. As the anionic surfactant, it is preferable to use at least one selected from alkyl ether sulfates, alkyl sulfates, and linear alkylbenzene sulfonates.

  The fusing step can be performed, for example, by heating the aggregated particles. This fusion step is preferably performed while stirring at a speed at which the aggregated particles do not settle.

  The temperature in the system in the fusing process is determined from the viewpoint of controlling the target toner particle size, particle size distribution, shape control and particle fusing property, “the softening point of the polyester having the lowest softening point−50 ° C. ”Or more,“ the softening point + 50 ° C. ”or less is preferable,“ the softening point −35 ° C. ”or more,“ the softening point + 35 ° C. ”or less is more preferable,“ the softening point−20 ° C. ”or more,“ the softening point ” + 20 ° C "or less is more preferable. The specific temperature in the system is preferably 60 ° C. or higher, more preferably 70 ° C. or higher, and preferably 140 ° C. or lower, more preferably 120 ° C. or lower.

  Toner particles can be obtained by subjecting the fused particles obtained in step 2-3 to a solid-liquid separation step such as filtration, a washing step, and a drying step as appropriate.

  In the washing step, it is preferable to use an acid in order to remove metal ions on the toner surface from the viewpoint of securing sufficient charging characteristics and reliability as the toner. Further, it is preferable to completely remove the added nonionic surfactant by washing, and washing with an aqueous solution below the cloud point of the nonionic surfactant is preferred. The washing is preferably performed a plurality of times.

  In the drying step, any method such as a vibration type fluidized drying method, a spray drying method, a freeze drying method, a flash jet method, or the like can be employed. The water content after drying the toner particles is preferably adjusted to 1.5% by mass or less, more preferably 1.0% by mass or less, from the viewpoint of improving the chargeability of the toner.

  In the method for producing an electrophotographic toner, from the viewpoint of improving the chargeability, fluidity, and transferability of the toner, the obtained toner particles (toner base particles) or agglomeration after the melt-kneading, pulverization, and classification steps are performed. It is preferable that after the washing step and the drying step, the obtained fused particles (toner base particles) are further mixed with an external additive.

  The content of the external additive is preferably 0.05 parts by mass or more with respect to 100 parts by mass of the toner base particles before being processed with the external additive, from the viewpoint of improving the chargeability, fluidity, and transferability of the toner. More preferably, it is 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, and preferably 5 parts by mass or less, more preferably 4 parts by mass or less, still more preferably 3 parts by mass or less.

  For mixing the toner base particles and the external additive, it is preferable to use a mixer equipped with a stirring tool such as a rotary blade, a high speed mixer such as a Henschel mixer or a super mixer is preferable, and a Henschel mixer is more preferable.

The volume median particle size (D ₅₀ ) of the electrophotographic toner of the present invention is preferably 3 μm or more, more preferably 4 μm or more, and even more preferably 6 μm or more, from the viewpoint of improving the image quality of the toner. The thickness is preferably 15 μm or less, more preferably 12 μm or less, and still more preferably 9 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 by the volume fraction is 50% when calculated from the smaller particle size. When the toner is treated with an external additive, the volume median particle size of the toner base particles is set as the volume median particle size of the toner.

  The electrophotographic toner obtained by the method of the present invention can be used as a one-component developing toner as it is, or as a two-component developing toner used by mixing with a carrier, as an image forming apparatus of a one-component developing system or a two-component developing system, respectively. Can be used.

In relation to the above-described embodiment, the present invention further discloses the following method for producing an electrophotographic toner.
<1> A crystal having at least a polyester moiety which is a polycondensate of an alcohol component containing an aliphatic diol having 9 to 14 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 9 to 14 carbon atoms A binder resin containing a conductive resin (C);
An ester wax (W) that is an aliphatic carboxylic acid ester of dipentaerythritol having 14 to 24 carbon atoms,
The mass ratio (C / W) of the crystalline resin (C) to the ester wax (W) is 1.0 or more and 40 or less,
An electrophotographic toner in which the content of the crystalline resin (C) is 1% by mass or more and 25% by mass or less with respect to the total amount of the binder resin.
<2> The electrophotographic toner according to <1>, wherein the ester wax (W) has an ester substitution number of dipentaerythritol with an aliphatic monocarboxylic acid of 5 or more and 6 or less.
<3> The mass ratio (C / W) of the crystalline resin (C) to the ester wax (W) is 1.0 or more, preferably 1.5 or more, more preferably 2.0 or more, more preferably 3.0 or more, and 40 The electrophotographic toner according to <1> or <2>, preferably 35 or less, more preferably 20 or less, still more preferably 15 or less, still more preferably 10 or less, and still more preferably 8 or less.
<4> The content of the crystalline resin (C) is 1% by mass or more, preferably 3% by mass or more, more preferably 4% by mass or more, and further preferably 7% by mass with respect to the total amount of the binder resin. And not more than 25% by mass, preferably not more than 23% by mass, more preferably not more than 20% by mass, still more preferably not more than 15% by mass, still more preferably not more than 12% by mass, <1> to <3 > The toner for electrophotography according to any one of the above.
<5> The toner for electrophotography according to any one of <1> to <4>, wherein the crystalline resin (C) is at least one selected from polyester and a composite resin having a polyester segment and a styrene resin segment. .
<6> A polyester segment in which the composite resin includes (i) an alcohol component containing an aliphatic diol having 9 to 14 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 9 to 14 carbon atoms A raw material monomer of (ii), a raw material monomer of a styrene resin segment, and (iii) a resin obtained by polymerizing a bireactive monomer capable of reacting with any of the raw material monomer of a polyester segment and the raw material monomer of a styrene resin segment The toner for electrophotography according to <5>.
<7> Both reactive monomers are compounds having in the molecule at least one functional group selected from a hydroxyl group, a carboxy group, an epoxy group, a primary amino group, and a secondary amino group, <6> The toner for electrophotography described in 1.
<8> The melting point of the crystalline resin (C) is 65 ° C. or higher, preferably 70 ° C. or higher, more preferably 75 ° C. or higher, still more preferably 80 ° C. or higher, and 150 ° C. or lower, preferably 135 ° C. or lower. The toner for electrophotography according to any one of <1> to <7>, which is more preferably 120 ° C. or lower.
<9> The softening point of the crystalline resin (C) is 75 ° C. or higher, preferably 80 ° C. or higher, more preferably 85 ° C. or higher, still more preferably 90 ° C. or higher, and 150 ° C. or lower, preferably 140 ° C. The toner for electrophotography according to any one of <1> to <8>, which is more preferably 120 ° C. or lower, and still more preferably 100 ° C. or lower.
<10> The acid value of the crystalline resin (C) is 40 mgKOH / g or less, preferably 30 mgKOH / g or less, more preferably 20 mgKOH / g or less, and 1 mgKOH / g or more, preferably 2 mgKOH / g or more. The toner for electrophotography according to any one of <1> to <9>.
<11> The melting point of the ester wax (W) is 60 ° C. or higher, preferably 65 ° C. or higher, and 150 ° C. or lower, preferably 135 ° C. or lower, more preferably 120 ° C. or lower, more preferably 100 ° C. or lower. The toner for electrophotography according to any one of <1> to <10>.
The content of <12> ester wax (W) is 0.3 parts by mass or more, preferably 0.8 parts by mass or more, more preferably 1.0 parts by mass or more, and still more preferably 2.0 with respect to 100 parts by mass of the total amount of the binder resin. <1> to 30 parts by mass, preferably 20 parts by mass or less, more preferably 10 parts by mass or less, still more preferably 5 parts by mass or less, and further preferably 3 parts by mass or less. <11> The electrophotographic toner according to any one of <11>.
<13> The toner for electrophotography according to any one of <1> to <12>, wherein the binder resin further contains an amorphous resin (A).
<14> The glass transition temperature of the amorphous resin (A) is 45 ° C. or higher, preferably 50 ° C. or higher, more preferably 55 ° C. or higher, and 80 ° C. or lower, preferably 75 ° C. or lower, more preferably The electrophotographic toner according to any one of <1> to <13>, which is 70 ° C. or lower, more preferably 65 ° C. or lower.
<15> The softening point of the amorphous resin (A) is 80 ° C or higher, preferably 95 ° C or higher, more preferably 100 ° C or higher, and 160 ° C or lower, preferably 150 ° C or lower, more preferably 140 ° C. ℃ or less,
<1>-<14> The electrophotographic toner according to any one of <14>.
<16> The acid value of the amorphous resin (A) is 40 mgKOH / g or less, preferably 30 mgKOH / g or less, more preferably 20 mgKOH / g or less, and 1 mgKOH / g or more, preferably 2 mgKOH / g or more. The toner for electrophotography according to any one of <1> to <15>.

  About each physical-property value of resin etc., it measured and evaluated by the following method.

[Measurement method of physical properties]
[Softening point of resin]
Using a flow tester “CFT-500D” (manufactured by Shimadzu Corporation), a 1 g sample was heated at a heating rate of 6 ° C./min, and a load of 1.96 MPa was applied by a plunger, with a diameter of 1 mm and a length of 1 mm. Extrude from nozzle. The amount of plunger drop of the flow tester is plotted against the temperature, and the temperature at which half of the sample flows out is taken as the softening point.

[Glass transition temperature of resin]
Using a differential scanning calorimeter “Q-20” (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of sample is weighed into an aluminum pan, heated to 200 ° C., and the temperature drop rate from that temperature is 10 ° C. Cool to 0 ° C at / min. Next, the sample is heated and measured at a heating rate of 10 ° C./min.
The glass transition temperature is defined as the temperature at the intersection of the base line extension below the maximum peak temperature of endotherm and the tangent line indicating the maximum slope from the peak rising portion to the peak apex.

[Maximum peak temperature and melting point of resin endotherm]
Using a differential scanning calorimeter “Q-100” (manufactured by TA Instruments Japan Co., Ltd.), 0.01 to 0.02 g of sample is weighed into an aluminum pan and cooled from room temperature to 0 ° C. at a rate of 10 ° C./min. It was left still for 1 minute. Thereafter, the measurement was carried out at a heating rate of 50 ° C./min. Of the endothermic peaks observed, the peak temperature appearing on the highest temperature side is defined as the highest endothermic peak temperature of the resin. If the maximum peak temperature is within 20 ° C of the softening point, the melting point is assumed.

[Acid value and hydroxyl value of resin]
The acid value and hydroxyl value of the resin are measured based on the method of JIS K0070. However, only the measurement solvent was changed from the mixed solvent of ethanol and ether specified in JIS K0070 to a mixed solvent of acetone and toluene (acetone: toluene = 1: 1 (volume ratio)).

[Melting point of release agent (wax)]
Using a differential scanning calorimeter “DSC Q20” (manufactured by TA Instruments Japan Co., Ltd.), the temperature was increased to 200 ° C. at a rate of temperature increase of 10 ° C./min, and the endotherm observed from the melting endotherm curve obtained there. Let the maximum peak temperature be the melting point of the release agent (wax).

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

[Volume Median Particle Size (D ₅₀ ) of Toner Base Particles]
The volume median particle size (D ₅₀ ) of the toner base particles was measured by the following method.
Measuring machine: Coulter Multisizer II (Beckman Coulter, Inc.)
Aperture diameter: 100μm
Analysis software: Coulter Multisizer AccuComp version 1.19 (Beckman Coulter)
Electrolyte: Isoton II (Beckman Coulter, Inc.)
Dispersion: Emulgen 109P (manufactured by Kao Corporation, polyoxyethylene lauryl ether, HLB: 13.6) is dissolved in the electrolyte so as to have a concentration of 5% by mass.
Dispersion conditions: 10 mg of a measurement sample was added to 5 ml of the dispersion, and dispersed for 1 minute with an ultrasonic disperser, then 25 ml of the electrolyte was added, and further dispersed for 1 minute with an ultrasonic disperser. Prepare sample dispersion.
Measurement conditions: The sample dispersion is added to 100 ml of the electrolytic solution so that the particle size of 30,000 particles can be measured in 20 seconds, and 30,000 particles are measured. Determine the median particle size (D ₅₀ ).

[Test method]
(Low temperature fixability)
The printer “OKI MICROLINE 5400” (made by Oki Data Co., Ltd.), modified to take unfixed images, was filled with toner, and a 2cm square solid unfixed image was printed. Using an external fixing device modified from OKI MICROLINE 3010 (manufactured by Oki Data Co., Ltd.), increasing the fixing roll temperature from 100 ° C to 230 ° C in 5 ° C increments at a fixing roll rotation speed of 150mm / sec. However, this unfixed image was fixed at each temperature to obtain a fixed image. After attaching a mending tape (manufactured by Sumitomo 3M Co., Ltd.) to the image obtained at each fixing temperature, the tape was sufficiently attached to the fixed image by placing a weight on a 500 g cylinder (diameter 3 cm). . Thereafter, the mending tape was slowly peeled off from the fixed image. Measure the image density of the fixed image before and after applying the tape using the image density measuring instrument “Gretag SPM50” (GretagMacbeth), and the image density ratio before and after application ([Image density after peeling / Affixing] The temperature at which the previous image density] × 100) first exceeded 85% was defined as the minimum fixing temperature, and was used as an index of low-temperature fixing property. The smaller the value, the better the low-temperature fixability. Specifically, 135 ° C. or lower is preferable, and 130 ° C. or lower is more preferable. The results are shown in Table 5.

[Heat resistant storage stability]
10 g of toner was placed in a 20 ml polybin. The polybin containing the toner was placed in a constant temperature and humidity chamber at 60 ° C. and a relative humidity of 30%, and left for 100 hours with the polybin open. The degree of aggregation of the toner after standing was measured and used as an index of heat resistant storage stability.
The degree of aggregation is measured using a powder tester (manufactured by Hosokawa Micron Corporation).
Overlay sieves with 150, 75, and 45 μm openings, place 5 g of toner on top, and vibrate for 60 seconds at a vibration width of 1 mm and a vibration frequency of 1 Hz. After the vibration, the amount of toner remaining on the sieve is measured, and the degree of aggregation is calculated using the following formula.

The smaller the degree of aggregation, the better the heat resistant storage stability. Specifically, it is preferably 40 or less, more preferably 35 or less, further preferably 30 or less, further preferably 26 or less, and further preferably 22 or less. The results are shown in Table 5.

[Production example of amorphous polyester resin]
Production Examples A1, A2 (Resin A-1, A-2)
Raw material monomers and esterification catalyst other than trimellitic anhydride shown in Table 1 were put into a 10 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple. The temperature was raised and reacted for 6 hours. After heating to 210 ° C, trimellitic anhydride is added, reacted at normal pressure (101.3 kPa) for 1 hour, and further reacted at 40 kPa until the desired softening point is reached. A-1 and A-2 were obtained. Table 1 shows the physical properties of the obtained resin.

[Production example of amorphous composite resin]
Production Example A3 (Resin A-3)
The raw material monomer of the polyester component other than trimellitic anhydride shown in Table 2 and the esterification catalyst were placed in a 10 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer, and a thermocouple. After carrying out the reaction for 1 hour, the reaction was carried out at 8.3 kPa for 1 hour. The temperature was lowered to 160 ° C., and the raw material monomer of styrene resin, the bireactive monomer, and dicumyl peroxide were added dropwise over 1 hour using a dropping funnel. After aging the addition polymerization reaction for 1 hour while maintaining at 160 ° C., the temperature was raised to 210 ° C., and the raw material monomer of the styrene resin was removed at 8.3 kPa for 1 hour.
Further, trimellitic anhydride was added at 210 ° C. and reacted until the desired softening point was reached to obtain amorphous composite resin A-3. Table 2 shows the physical properties of the obtained resin.

[Production example of crystalline resin (C)]
Production Examples C1 to C3, C5 (Resin C-1 to C-3, C-5)
The raw material monomer of the polyester component shown in Table 3 and the esterification catalyst are put into a 10 L four-necked flask equipped with a nitrogen introduction tube, a dehydration tube, a stirrer and a thermocouple, heated to 160 ° C. and reacted for 6 hours. It was.
Then, the raw material monomer of styrene resin shown in Table 3, an amphoteric monomer, and dicumyl peroxide were dripped over 1 hour with the dropping funnel. After aging the addition polymerization reaction for 1 hour while maintaining at 160 ° C., the raw material monomer of the styrene resin was removed at 8.3 kPa for 1 hour. Further, the temperature was raised to 200 ° C. over 8 hours and reacted at 8.3 kPa for 2 hours to obtain crystalline resins C1 to 3 and 5. Table 3 shows the physical properties of the obtained resin.

Production Examples C4, C6 (Resin C-4, C-6)
The raw material monomers shown in Table 3 and the esterification catalyst were placed in a 10-liter four-necked flask equipped with a nitrogen introduction tube, dehydration tube, stirrer and thermocouple, and from nitrogen to 130 ° C for 10 hours under a nitrogen atmosphere. The mixture was heated up and reacted at 200 ° C. and 8 kPa for 1 hour to obtain crystalline resins C-4 and C-6. Table 3 shows the physical properties of the obtained resin.

Production Examples W1 to W4 (Wax W-1 to W-4)
As an alcohol component, dipentaerythritol 254 g (1.0 mol), as a monocarboxylic acid component, stearic acid 1707 g (6.0 mol) was placed in a 5 L four-necked flask, and while distilling off the generated water under a nitrogen stream, 220 The reaction was carried out at ° C for 10 hours. The acid value of the product was 7.2 mg KOH / g.
Toluene 500 g, 2-propanol 330 g, and 10 mass% potassium hydroxide aqueous solution 267 g were added, stirred at 70 ° C. for 1 hour, allowed to stand for 30 minutes, and then the aqueous layer was removed. Washed with ion exchanged water at 70 ° C. until pH was 7. The solvent was distilled off from the obtained wax-containing solution under reduced pressure, and after filtration, solidification and pulverization, wax W-1 was obtained.
Waxes W-2 to W-4 were obtained in the same manner as in Production Example W1, except that the monocarboxylic acid component was replaced with the components listed in Table 4.
The hydroxyl value of the obtained wax was measured and shown in Table 4.
Table 4 below shows information on the waxes obtained in the production examples and the commercially available waxes used in the examples.

[Example of toner production]
Examples 1-15, 18, 19 and Comparative Examples 1-6
Table 5 shows a predetermined amount of binder resin 100 parts by mass and release agent, charge control agent “Bontron E-304” (manufactured by Orient Chemical Co., Ltd.) 1.0 part by mass, and colorant “ECB-301” (large 3.0 parts by mass of Nissei Kagaku Kogyo phthalocyanine blue (PB15: 3) were mixed for 1 minute using a Henschel mixer, and then melt-kneaded under the conditions shown below.

A co-rotating twin screw extruder “PCM-30” (manufactured by Ikegai Co., Ltd., shaft diameter 2.9 cm, shaft cross section 7.06 cm ² ) was used. Operating conditions are: barrel set temperature 110 ° C, shaft rotation speed 200r / min (shaft rotation peripheral speed 0.30m / sec), mixture supply speed 10kg / h (mixture supply rate per unit cross section of shaft 1.42kg / h)・ Cm ² ).

The obtained resin kneaded product is cooled and coarsely pulverized by a pulverizer “ROTOPLEX” (manufactured by Hosokawa Micron Co., Ltd.) to obtain a coarsely pulverized product having a volume median particle diameter of 2 mm or less using a sieve having an opening of 2 mm. It was. The obtained coarsely pulverized product was finely pulverized using a DS2 type air classifier (impact plate type, manufactured by Nippon Pneumatic Co., Ltd.) so that the volume median particle size was adjusted to 8.0 μm. Adjust the static pressure (internal pressure) of the resulting finely pulverized product using a DSX2 type airflow classifier (manufactured by Nippon Pneumatic Co., Ltd.) so that the volume median particle size (D ₅₀ ) is 8.5 μm. Classification was performed to obtain toner particles.

  100 parts by mass of the obtained toner particles, 0.8 part by mass of hydrophobic silica “R972” (manufactured by Nippon Aerosil Co., Ltd., hydrophobizing agent: DMDS, average particle size: 16 nm), and hydrophobic silica “RY50 (Nippon Aerosil Co., Ltd., Hydrophobizing agent: Silicone oil, average particle size: 40 nm) 1.0 part by mass using a Henschel mixer (Nihon Coke Industries Co., Ltd.) 2100 r / min (circumferential speed 29 m / sec) Was mixed for 3 minutes to obtain a toner.

[Manufacture of emulsified toner]
Example 16 Production of Toner 16 (Production of Aqueous Dispersion A)
In a 3 L container equipped with a stirrer, reflux condenser, dropping funnel, thermometer and nitrogen introduction tube, 150 g of Resin A-1 and 75 g of ethyl acetate were charged and dissolved at 70 ° C. over 2 hours. A 20% by mass aqueous ammonia solution (pKa: 9.3) was added to the obtained solution so that the degree of neutralization was 100 mol% with respect to the acid value of the resin, and the mixture was stirred for 30 minutes to obtain a mixture. While maintaining at 70 ° C., 675 g of ion-exchanged water was added over 77 minutes while stirring at 280 r / min (peripheral speed 88 m / min), and phase inversion emulsification was performed to obtain a crude dispersion of resin particles. While maintaining at 70 ° C., ethyl acetate was distilled off under reduced pressure to obtain an aqueous dispersion of resin particles.
Thereafter, the aqueous dispersion was cooled to 30 ° C. while stirring at 280 r / min (peripheral speed 88 m / min), and then the anionic surfactant “Emar E27C” (polyoxyethylene lauryl ether sodium sulfate, manufactured by Kao Corporation) 16.7 g of a solid content of 28% by mass) was mixed and completely dissolved. Thereafter, the solid concentration of the aqueous dispersion was measured, and ion exchange water was added to adjust the solid concentration of the aqueous dispersion to 20% by mass. The volume median particle size (D ₅₀ ) of the resin particles in the obtained aqueous dispersion was 203 nm.

(Production of aqueous dispersion C)
In a 1-L beaker, 30 g of crystalline resin C-1 and 270 g of chloroform were stirred and mixed at 25 ° C. to dissolve crystalline resin C-1, and 100 g of Neoperex G-15 (manufactured by Kao Corporation) was added. Then, with “TK Robomix” (manufactured by Primix Co., Ltd.), the mixture was stirred for 30 minutes at a rotation speed of 8000 r / min to prepare an emulsion. Chloroform was distilled off from the obtained emulsion under reduced pressure to obtain an aqueous dispersion C. The volume median particle size (D ₅₀ ) of the particles in the aqueous dispersion C was 287 nm, and the solid content concentration was 23% by mass.

(Manufacture of colorant dispersion)
Copper phthalocyanine "ECB-301" (Daiichi Seika Kogyo Co., Ltd.) 50g, nonionic surfactant "Emulgen 150" (polyoxyethylene lauryl ether, Kao Corporation) 5g and ion-exchanged water 200g are mixed. A colorant dispersion containing colorant particles was obtained by dispersing for 10 minutes using a homogenizer. The volume median particle size (D ₅₀ ) of the colorant particles was 120 nm, and the solid content concentration was 22% by mass.

(Manufacture of charge control agent dispersion)
50 g of salicylic acid compound “Bontron E-304” (manufactured by Orient Chemical Co., Ltd.) as a charge control agent, 5 g of “Emulgen 150” (manufactured by Kao Corporation) as nonionic surfactant, and 200 g of ion-exchanged water are mixed. Glass beads were used and dispersed for 10 minutes using a sand grinder to obtain a charge control agent dispersion containing charge control agent particles. The volume median particle size (D ₅₀ ) of the charge control agent particles was 400 nm, and the solid content concentration was 22% by mass.

(Manufacture of release agent dispersion)
Dissolve 3.8 g of sodium acrylate-sodium maleate copolymer aqueous solution (trade name: Poise 521, effective concentration 40 mass%) as a sodium polycarboxylate aqueous solution in 200 g of deionized water in a 1 liter beaker. After that, 50 g of release agent W-1 (see the description below) was added thereto, and the mixture was stirred while stirring at a temperature of 90 to 95 ° C., and an ultrasonic homogenizer (manufactured by Nippon Seiki Co., Ltd., (Product name: US-600T) was dispersed for 30 minutes and then cooled to room temperature, and ion-exchanged water was added thereto to adjust the release agent solid content to 20% by mass to obtain release agent particle dispersion A It was.
The volume median particle size (D ₅₀ ) of the release agent particles in the release agent particle dispersion was 423 nm.

(Manufacture of toner)
Place 315.0 g of aqueous dispersion A, 42.0 g of aqueous dispersion C, 9.5 g of colorant dispersion, 8.8 g of release agent dispersion, 3.2 g of charge control agent dispersion, and 60 g of deionized water in a 3 L container. While stirring at 100 r / min (peripheral speed 31 m / min) with an anchor-type stirrer, 150 g of a 0.1 mass% calcium chloride aqueous solution was added dropwise at 20 ° C. over 30 minutes. Then, it heated up to 50 degreeC, stirring. After the volume median particle size (D ₅₀ ) reaches 8.0 μm, 4.2 g of anionic surfactant “Emar E27C” (manufactured by Kao Corporation, solid content 28% by mass) as a coagulation terminator with 37 g of deionized water The diluted diluent was added to obtain an aggregate X. Next, the temperature was raised to 75 ° C. After 75 ° C. was maintained for 1 hour, heating was terminated. Thus, fused particles were formed, and then gradually cooled to 20 ° C., filtered through a wire mesh of 150 mesh (aperture 150 μm), suction filtered, washed and dried to obtain toner particles.
An external addition process was performed in the same manner as in Example 1 to obtain a toner.

Example 17: Production of Toner 17 A toner was obtained in the same manner as in Example 1 except that the release agent dispersion A used was changed to the following release agent dispersion B.

Release agent dispersion B
A release agent particle dispersion B was prepared in the same manner as the release agent particle dispersion A except that the release agent used was W2 (Table 4). The volume median particle size (D ₅₀ ) of the release agent particles in the release agent particle dispersion B was 418 nm.

  From the above results, it can be seen that the toners of Examples 1 to 19 are superior in low-temperature fixability and heat-resistant storage stability as compared with Comparative Examples 1 to 6.

Claims (6)

A crystalline resin having at least a polyester moiety that is a polycondensate of an alcohol component containing an aliphatic diol having 9 to 14 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 9 to 14 carbon atoms ( A binder resin comprising C);
An ester wax (W) that is an aliphatic carboxylic acid ester of dipentaerythritol having 14 to 24 carbon atoms,
The mass ratio (C / W) of the crystalline resin (C) to the ester wax (W) is 1.0 or more and 40 or less,
An electrophotographic toner in which the content of the crystalline resin (C) is 1% by mass or more and 25% by mass or less with respect to the total amount of the binder resin.   The electrophotographic toner according to claim 1, wherein the ester wax (W) has an ester substitution number of dipentaerythritol with an aliphatic monocarboxylic acid of 5 or more and 6 or less.   3. The electron according to claim 1, wherein the crystalline resin (C) is at least one selected from a polyester comprising the polyester moiety, and a composite resin having a polyester segment comprising the polyester moiety and a styrene resin segment. Toner for photography.   The composite resin comprises: (i) an alcohol component containing an aliphatic diol having 9 to 14 carbon atoms and a carboxylic acid component containing an aliphatic dicarboxylic acid compound having 9 to 14 carbon atoms. , (Ii) a raw material monomer of a styrene resin segment, and (iii) a resin obtained by polymerizing both reactive monomers capable of reacting with either a raw material monomer of a polyester segment and a raw material monomer of a styrene resin segment, The electrophotographic toner according to claim 3.   The both reactive monomers are compounds which have at least 1 sort (s) of functional group chosen from a hydroxyl group, a carboxy group, an epoxy group, a primary amino group, and a secondary amino group in a molecule | numerator. Toner for electrophotography.   The toner for electrophotography according to claim 1, wherein the binder resin further contains an amorphous resin (A).