JP2023058063A - Method for manufacturing electrostatic charge image development toner - Google Patents

Abstract

To provide a method for manufacturing electrostatic charge image development toner excellent in low temperature fixability and durability.SOLUTION: A method for manufacturing electrostatic charge image development toner comprises the step of melting and mixing the mixture of a raw material including an amorphous resin, a crystalline polyester resin and a release agent by a twin screw extruder. In one or more material supply ports included at each of a position f1 having less than 0.3 L from the entrance side end of a barrel and a position f2 having 0.3 L or more and 0.9 L or less when setting the length of the barrel of the twin screw extruder to L. A raw material including the amorphous resin is supplied from a material supply port F1 at the position f1, and a raw material including the crystalline polyester resin and the release agent is supplied from a material supply port F2 at the second position f2.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.

In recent years, as printers and copiers have become faster, smaller, and have higher image quality, there has been a need for toners that can meet these demands.

Conventionally, in order to design arbitrary toners, various studies have been made on methods for manufacturing toners. For example, in Patent Document 1, a kneading extruder with a barrel length L having extrusion flowability is disclosed in a method of producing a toner by melt-kneading, cooling, solidifying, pulverizing, and classifying a composition comprising a resin and an additive. Continuously supply a mixed raw material with an additive concentration in the resin (hereinafter referred to as the additive concentration in the first half) of 10 to 50% by weight from at least one raw material supply port provided within 0.3 L from the inlet side of the Then, from 1 to 5 raw material supply ports provided at 0.3 L to 0.9 L from the inlet side, the resin alone or the additive concentration in the resin is 20% by weight or less and the concentration is lower than the additive concentration in the first half of raw material continuously, and the ratio of the supply flow rate between the raw material supplied to the raw material supply port at the position within 0.3 L and the raw material supplied to the raw material supply port at the position of 0.3 L to 0.9 L is 10: 1 ~ The continuous production method of the toner is characterized by a 1:5 (weight ratio) and continuous extraction of the kneaded product from the outlet of the kneading extruder. It is described that a high-quality toner with less molecular cleavage can be obtained.

Further, Patent Document 2 discloses a method for producing a toner for electrostatic charge image development in which at least a resin and a colorant are compounded and mixed, kneaded, then pulverized and classified to obtain a toner. A large amount of toner fine powder can be recycled into the manufacturing process with good productivity, and the fine powder recycled toner has little deterioration in performance and good fixing performance. It is described that a toner having stable image and image quality characteristics even in continuous use and excellent durability performance can be obtained.

JP-A-3-149567 JP-A-8-95296

However, the toners described in Patent Documents 1 and 2 are still unsatisfactory in low-temperature fixability and durability, and there is room for improvement.

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 relates to a method for producing a toner for developing an electrostatic charge image, comprising a step of melt-kneading a mixture of raw materials containing an amorphous resin, a crystalline polyester resin, and a release agent using a twin-screw extruder, When the length of the barrel of the twin screw extruder is L, one or more raw material supply ports are provided at a position f1 less than 0.3L from the entrance side end of the barrel and a position f2 at 0.3L or more and 0.9L or less. for electrostatic charge image development, wherein a raw material containing an amorphous resin is supplied from the raw material supply port F1 of the f1, and a raw material containing a crystalline polyester resin and a release agent is supplied from the raw material supply port F2 of the f2. The present invention relates to a method for manufacturing toner.

According to the method of the present invention, a toner for electrostatic charge image development having excellent low-temperature fixability and durability can be obtained.

The present invention relates to a method for producing a toner for developing an electrostatic charge image, comprising a step of melt-kneading a mixture of raw materials containing an amorphous resin, a crystalline polyester resin, and a release agent using a twin-screw extruder. When the mixture is melt-kneaded by a twin-screw extruder, the amorphous resin, the crystalline polyester resin and the release agent are supplied to the twin-screw extruder from predetermined positions, respectively, to improve low-temperature fixability and The present inventors have found that a toner for developing electrostatic images (hereinafter also simply referred to as toner) having excellent durability can be obtained, and have completed the present invention.

Although the details of the reason why the effect of the present invention is exhibited are unknown, it is presumed to be due to the following mechanism.
Crystalline polyester resin has excellent low-temperature fixability, but when melt-kneaded using a twin-screw extruder with excellent productivity and versatility, it separates from the amorphous binder resin, which is the main component of toner, and releases. It tends to form coarse domains together with the agent, and as the amount added increases, the durability tends to decrease in a high-temperature, high-humidity environment.
For example, in Patent Document 1, in the melt-kneading process of a kneading extruder, by kneading a dispersion target such as a pigment for a long time, the dispersion state is improved and an appropriate dispersion diameter is maintained. It is known to divide the raw material supply port so as to shorten the kneading time in order to avoid this. However, the present inventors' studies have revealed that the dispersion of the crystalline polyester resin is not limited to this. In the melt-kneading process of the twin-screw extruder, the raw material mixture is heated by rubbing against the barrel, and melt-kneading proceeds. However, when the crystalline polyester resin is added in addition to the release agent, the release agent and the crystalline polyester resin melt before the amorphous binder resin in the barrel, reducing the viscosity of the main component. The friction with the barrel necessary for melting the amorphous binder resin is insufficient. As a result, it was necessary to disperse the crystalline polyester resin and release agent in a state in which the amorphous binder resin, which is the main component and serves as a dispersion medium, was insufficiently melted. The crystalline polyester-based resin and the release agent are in a state of being dispersed at a certain concentration. As a result, sufficient kneading strength is not imparted, and coarse domains of the crystalline polyester resin and the release agent are formed.
On the other hand, in the present invention, the raw material containing the amorphous resin is supplied from the raw material supply port F1 near the entrance side end of the barrel of the twin-screw extruder, and the raw material is supplied from the entrance side end of the barrel rather than the raw material supply port F1. By supplying a raw material containing a crystalline polyester resin and a release agent from a separate raw material supply port F2 and melt-kneading the raw material, sufficient friction between the amorphous binder resin and the barrel can be ensured. As a result, the amorphous binder resin, which serves as a dispersion medium, can be sufficiently melted, and the crystalline polyester resin and the release agent can be satisfactorily dispersed. can be obtained.

Examples of amorphous resins include amorphous polyester resins, vinyl resins such as styrene resins, epoxy resins, polycarbonate resins, polyurethane resins, composite resins containing two or more of these resins, and the like. Among these, polyester-based resins are preferable from the viewpoint of low-temperature fixability. Examples of polyester-based resins include polyester resins, composite resins containing polyester resins and styrene-based resins, and the like.

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 taken as the melting point.

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.

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 (COOH group/OH group) between the carboxylic acid component and the alcohol component is preferably 0.6 or higher, more preferably 0.7 or higher, and still more preferably 0.75 or higher, from the viewpoint of adjusting the softening point of the polyester resin, and , preferably 1.2 or less, more preferably 1.16 or less.

Amorphous polyester resin, for example, an alcohol component and a carboxylic acid component in an inert gas atmosphere, preferably in the presence of an esterification catalyst, further optionally in the presence of an esterification co-catalyst, a polymerization inhibitor, etc. , preferably 160°C or higher, more preferably 200°C or higher, and preferably 250°C or lower, more preferably 240°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.

In the amorphous 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, α-methylstyrene, vinyl toluene, or the like. (Styrene and styrene derivatives are hereinafter 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 in terms of storage stability 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 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 amorphous composite resin is preferably a resin in which a polyester resin and a styrenic resin are combined. More preferably, it is a physically bonded resin.

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.

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 charging stability under high temperature and high humidity conditions. From the viewpoint of improving the dispersibility of the styrene-based resin and the polyester resin and improving the transferability 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 charging stability under high temperature and high humidity conditions, the amount of the bi-reactive monomer used is preferably 1 part by mass or more, more preferably 2 parts by mass, with respect to the total 100 parts by mass of the raw material monomers for the styrene resin. It is at least 30 parts by mass, more preferably 20 parts by mass or less, still more preferably 10 parts by mass, from the viewpoint of enhancing the dispersibility of the styrene-based resin and the polyester resin and improving the transferability of the toner. Part by mass or less. Here, the polymerization initiator is included in the sum of the raw material monomers for the styrene resin.

The amorphous composite resin can be produced, for example, by a method including a step (A) of a polycondensation reaction using raw material monomers for a polyester resin and a step (B) of an addition polymerization reaction using raw material monomers for a styrene-based resin. . (i) step (B) may be performed after step (A); (ii) step (A) may be performed after step (B); (iii) step (A) and step (B ) may be performed at the same time. The bi-reactive monomer is preferably used together with the raw material monomer for the styrenic resin.

In the method (i), after the step (B), the reaction temperature is raised again, and if necessary, a raw material monomer for a trivalent or higher amorphous polyester resin as a cross-linking agent is added to the reaction system, and the step The polycondensation reaction of (A) and the reaction with the bireactive monomer may be further advanced.
Further, instead of the step (A) of conducting a polycondensation reaction, a prepolymerized polycondensation resin may be used. When the step (A) and the step (B) are carried out in parallel, the mixture containing the raw material monomers for the styrene resin may be added dropwise to the mixture containing the raw material monomers for the polyester resin to cause the reaction. .

Step (A) and step (B) are preferably carried out in the same container.

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

The softening point of the amorphous resin is preferably 90° C. or higher, more preferably 100° C. or higher, from the viewpoint of storage stability, and preferably 160° 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 fixing width, the amorphous resin may be composed of resins having different softening points. The difference in softening point between the two resins is preferably 10°C or more, more preferably 20°C or more, still more preferably 30°C or more, and preferably 60°C or less, more preferably 50°C or less.

The softening point of the amorphous resin having a higher softening point (resin AH) is preferably 110°C or higher, more preferably 120°C or higher, and still more preferably 140°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.

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, still more preferably 100°C or higher, from the viewpoint of storage stability, and , preferably 130°C or less, more preferably 125°C or less, still more preferably 120°C or less, from the viewpoint of low-temperature fixability.

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 is preferably 40°C or higher, more preferably 50°C or higher, from the viewpoint of storage stability, 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 is preferably 1 mgKOH/g or more, more preferably 3 mgKOH/g or more, from the viewpoint of low-temperature fixability, and preferably 20 mgKOH/g or less, more preferably from the viewpoint of hygroscopicity. is less than 15mgKOH/g.

From the viewpoint of transfer efficiency, the content of the amorphous resin is preferably 55% by mass or more, more preferably 60% by mass or more, and still more preferably 70% by mass in the total amount of the amorphous resin and the crystalline polyester resin. % or more, more preferably 80 mass % or more, and from the viewpoint of low-temperature fixability, preferably 99 mass % or less, more preferably 97 mass % or less, and even more preferably 96 mass % or less.

Crystalline polyester resins include crystalline polyester resins, crystalline composite resins containing polyester resins and styrene resins, and the like.

As the crystalline polyester resin, for example, a polycondensate of an alcohol component containing an aliphatic diol and a carboxylic acid component containing an aliphatic dicarboxylic acid compound is preferable.

Aliphatic diols include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,7-heptanediol , 1,8-octanediol, neopentyl glycol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, and the like. , may be used in combination of two or more.

From the viewpoint of low-temperature fixability, the aliphatic diol is preferably an α,ω-aliphatic diol having a hydroxyl group at the end of the carbon chain, more preferably an α,ω-straight-chain alkanediol. .

The number of carbon atoms in the aliphatic diol is preferably 6 or more, more preferably 10 or more, from the viewpoint of dispersibility of the colorant, and preferably 14 or less, more preferably 12 or less, from the viewpoint of storage stability. be.

The content of the aliphatic diol 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.

Other alcohol components include aromatic diols such as alkylene oxide adducts of bisphenol A, trihydric or higher alcohols such as sorbitol, pentaerythritol, glycerin and trimethylolpropane.

Aliphatic dicarboxylic acid compounds include succinic acid (4 carbon atoms), fumaric acid (4 carbon atoms), adipic acid (6 carbon atoms), suberic acid (8 carbon atoms), azelaic acid (8 carbon atoms), : 9), sebacic acid (carbon number: 10), dodecanedioic acid (carbon number: 12), tetradecanedioic acid (carbon number: 14), succinic acid having an alkyl group or alkenyl group in the side chain, these acids Examples thereof include anhydrides and alkyl esters of these acids having 1 to 3 carbon atoms.

The number of carbon atoms in the aliphatic dicarboxylic acid compound is preferably 4 or more, more preferably 8 or more, from the viewpoint of low-temperature fixability, and preferably 14 or less, more preferably 12 or less, from the viewpoint of storage stability. is.

The content of the aliphatic dicarboxylic acid compound in the carboxylic acid component is preferably 70 mol% or more, more preferably 80 mol% or more, still more preferably 90 mol% or more, still more preferably 95 mol% or more.

Other carboxylic acid components include aromatic dicarboxylic acid-based compounds, aliphatic dicarboxylic acid-based compounds, and trivalent or higher carboxylic acid-based compounds.

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 carboxylic acid component to the alcohol component (COOH group/OH group) is preferably 0.8 or more, more preferably 0.9 or more from the viewpoint of storage stability, and preferably 1.2 or less from the viewpoint of low temperature fixability. , more preferably 1.1 or less.

The polycondensation reaction conditions of the alcohol component and the carboxylic acid component of the crystalline polyester resin are the same as those of the amorphous polyester resin except that the preferred reaction temperature is different. The reaction temperature is preferably 120° C. or higher, more preferably 180° C. or higher, and preferably 230° C. or lower, more preferably 220° C. or lower.

In the crystalline composite resin containing the polyester resin and the styrene resin, the polyester resin is the same as the crystalline polyester resin, and the styrene resin is at least styrene or styrene such as α-methylstyrene and vinyltoluene. 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 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more, still more preferably 95% by mass or more, from the viewpoint of storage stability in the raw material monomer of the styrene resin. is 100% by mass.

Raw material monomers for styrene resins include raw material monomers other than styrene compounds, such as (meth)acrylic acid alkyl esters, 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 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 crystalline composite resin is preferably a resin in which a polyester resin and a styrenic resin are bonded together. More preferably, it is a resin bonded to

The manufacturing method of the bi-reactive monomer and the crystalline composite resin is the same as that of the composite resin described as the amorphous resin.

The mass ratio of the polyester resin to the styrene resin (polyester resin/styrene resin) in the crystalline composite resin is preferably 98/2 or less, more preferably 95/5, from the viewpoint of charging stability under high temperature and high humidity conditions. Below, it is more preferably 90/10 or less, and from the viewpoint of low-temperature fixability, it is preferably 60/40 or more, more preferably 70/30 or more, and still more preferably 75/25 or more. In the above calculation, the mass of the polyester resin 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 polyester resin to be used. The amount of is included in the raw material monomer amount of the polyester resin. Moreover, the amount of styrene resin is the total amount of raw material monomers of the styrene resin.

The softening point of the crystalline polyester resin is preferably 50°C or higher, more preferably 65°C or higher, and still more preferably 70°C or higher from the viewpoint of storage stability, and preferably 120°C from the viewpoint of low-temperature fixability. °C or less, more preferably 110°C or less.

The melting point of the crystalline polyester resin is preferably 60°C or higher, more preferably 70°C or higher, from the viewpoint of storage stability, and preferably 130°C or lower, more preferably 120°C, from the viewpoint of low-temperature fixability. It is below.

The content of the crystalline polyester resin is preferably 1% by mass or more, more preferably 3% by mass or more, and still more preferably It is 4% by mass or more, and from the viewpoint of transfer efficiency, 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.

The mass ratio of the amorphous resin to the crystalline polyester resin (amorphous resin/crystalline polyester resin) is preferably 60/40 or more, more preferably 65/35 or more, and more preferably 65/35 or more, from the viewpoint of low-temperature fixability. It is preferably 70/30 or more, and from the viewpoint of transfer efficiency, preferably 99/1 or less, more preferably 97/3 or less, and even more preferably 95/5 or less.

The toner contains an amorphous resin and a crystalline polyester resin as a binder resin.

The total content of the amorphous resin and the crystalline polyester resin 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. Above, 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 transferability, 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, more preferably 100° 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 transferability of the toner and dispersibility in the binder resin. is 1 part by mass or more, more preferably 2 parts by mass or more, and is preferably 10 parts by mass or less, more preferably 8 parts by mass or less, still more preferably 7 parts by mass or less, still more preferably 4 parts by mass or less .

The total amount of the crystalline polyester resin and the release agent is preferably 5 parts by mass or more, more preferably 7 parts by mass or more, and even more preferably It is 9 parts by mass or more, and preferably 40 parts by mass or less, more preferably 30 parts by mass or less, and even more preferably 20 parts by mass or less.

As toner raw materials, in addition to amorphous resins and crystalline polyester resins that are binding resins and release agents, colorants, charge control agents, magnetic powders, fluidity improvers, conductivity modifiers, fibrous substances, etc. Additives such as reinforcing fillers, antioxidants and cleaning improvers may also be used.

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.; polyamine resins such as "AFP-B" (Orient Chemical Industry Co., Ltd.) ), 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.), “Eizenspiron 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, an amorphous resin, a crystalline polyester resin, a release agent, and, if necessary, additives such as a coloring agent and a charge control agent are subjected to a step of melt-kneading using a twin-screw kneader. .

The twin-screw kneader is a kneader that kneads and discharges the supplied raw material while extruding it by rotating two screw shafts in a cylinder (barrel). It has two or more openings. When the length of the barrel of the twin-screw extruder is L, one or more raw material supply ports are provided at position f1 less than 0.3L from the entrance side end of the barrel and position f2 at 0.3L or more and 0.9L or less. . The number of raw material supply ports is not particularly limited, but the standard specification is that there is usually one raw material supply port for a twin-screw kneader. , f2 are preferably two or less.

f1 is preferably 0.01 L or more, more preferably 0.02 L or more, still more preferably 0.03 L or more, and preferably 0.3 L or less, more preferably 0.2 L or less, still more preferably 0.1 L or less.

f2 is preferably 0.3 L or more, more preferably 0.35 L or more, still more preferably 0.4 L or more, and is preferably 0.9 L or less, more preferably 0.8 L or less, still more preferably 0.7 L or less.

The distance between the raw material supply port F1 of f1 and the raw material supply port F2 of f2 is preferably 0.1 L or more, more preferably 0.2 L or more, still more preferably 0.3 L or more, and preferably 0.9 L or less, more preferably It is 0.7L or less, more preferably 0.5L or less. When there are a plurality of raw material supply ports F1 and F2, the distance between the closest raw material supply port F1 and raw material supply port F2 is preferably within the above range.

A raw material containing an amorphous resin is supplied from the raw material supply port F1 of f1.

The amorphous resin supplied from the raw material supply port F1 is preferably 60% 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 of the amorphous resin contained in the toner. % by mass or more, more preferably 100% by mass. Here, the amount of the amorphous resin supplied from the raw material supply port F1 means the total amount of the amorphous resin supplied from the raw material supply ports when the raw material supply port F1 is provided with two or more raw material supply ports. do.

The content of the amorphous resin in the raw material supplied from the raw material supply port F1 is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and 100% by mass or less. , preferably 98% by mass or less, more preferably 96% by mass or less.

A raw material containing a crystalline polyester resin and a release agent is supplied from the raw material supply port F2 of f2.

The crystalline polyester resin supplied from the raw material supply port F2 is preferably 60% by mass or more, more preferably 80% by mass or more, still more preferably 90% by mass or more, still more preferably 90% by mass or more of the crystalline polyester resin contained in the toner. is 95% by mass or more, more preferably 100% by mass. Here, when the raw material supply port F2 is provided with two or more raw material supply ports, the amount of the crystalline polyester resin supplied from the raw material supply port F2 is the total amount of the crystalline polyester resin supplied from those raw material supply ports. means

The release agent supplied from the raw material supply port F2 is preferably 60% 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 of the release agent contained in the toner. Above, more preferably 100% by mass. Here, the amount of the release agent supplied from the raw material supply port F2 means the total amount of the release agent supplied from the raw material supply ports when the raw material supply port F2 is provided with two or more raw material supply ports.

Additives such as colorants and charge control agents may be supplied from either one of the raw material supply ports F1 and F2, or may be separately supplied. It is preferable to supply from

The total amount of the amorphous resin and the crystalline polyester resin supplied from the raw material supply port F2 is preferably less than 50% by mass, more preferably less than 50% by mass of the total amount of the amorphous resin and the crystalline polyester resin contained in the toner. is 40% by mass or less, more preferably 30% by mass or less, more preferably 15% by mass or less, and preferably 3% by mass or more, more preferably 5% by mass or more, and still more preferably 7% by mass or more. .

The raw materials to be supplied to each raw material supply port are preferably mixed in advance with a mixer such as a Henschel mixer or a ball mill before being supplied.

The set temperature of the barrel is preferably 70° C. or higher, more preferably 80° C. or higher, still more preferably 90° C. or higher from the viewpoint of fixing width, and preferably 160° C. or lower, more preferably 160° C. or lower from the viewpoint of durability. is 150°C or less, more preferably 140°C or less.

The twin-screw extruder is classified into a co-rotating type and a counter-rotating type depending on the direction of rotation of the screw shafts.

After melt-kneading with a twin-screw extruder, the kneaded product is preferably cooled until it reaches a hardness that allows pulverization, and if necessary, a pulverization step and a classification step are performed 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 step, the kneaded material may be pulverized to a desired particle size at once or in stages. It is preferable to carry out in stages.

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

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 in the classification process 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.

The present invention preferably further includes an external addition step of mixing the obtained toner particles with an external additive. A mixer such as a Henschel mixer can be used to mix the toner particles and the 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 toner transferability, hydrophobic silica subjected to 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 preferably 250 nm or less, from the viewpoint of toner chargeability, fluidity, and transferability. It is preferably 200 nm or less, 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, with respect to 100 parts by mass of the toner particles before being treated with the external additive, from the viewpoints of chargeability, fluidity, and transferability of the toner. It is at least 0.3 parts by mass, preferably at least 0.3 parts by mass, and preferably at most 5 parts by mass, more preferably at most 3 parts by mass.

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. 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 Co., Ltd.), weigh 0.01 to 0.02 g of the sample in an aluminum pan, heat it up to 200 ° C, and from that temperature Cool to 0°C at a cooling rate of 10°C/min. Next, the sample is heated at a heating rate of 10°C/min, and the endothermic peak is measured. The 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 K0070:1992. However, only the measurement solvent is 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]
Using a differential scanning calorimeter "DSC Q20" (manufactured by TA Instruments Japan Co., Ltd.), weigh 0.01 to 0.02 g of the sample in an aluminum pan and heat it up to 200 ° C at a heating rate of 10 ° C / min. The temperature is raised and then cooled to -10°C at a cooling rate of 5°C/min. Next, the sample is heated up to 180°C at a heating rate of 10°C/min and measured. The maximum endothermic peak temperature observed from the melting endothermic curve thus obtained is taken as the melting point of the release agent.

[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 II (manufactured by Beckman Coulter, Inc.)
Aperture diameter: 100 μm
Analysis software: Coulter Multisizer AccuComp version 1.19 (manufactured by Beckman Coulter, Inc.)
Electrolyte: Isoton II (manufactured by Beckman Coulter, Inc.)
Dispersion: Emulgen 109P (manufactured by Kao Corporation, polyoxyethylene lauryl ether, HLB (griffin): 13.6) was dissolved in the electrolytic solution to adjust it to 5% by mass Dispersion conditions: 10 mg of measurement sample in 5 mL of the dispersion and dispersed for 1 minute with an ultrasonic dispersion machine (machine name: US-1 manufactured by SND Co., Ltd., output: 80 W), then 25 mL of the electrolytic solution is added, and furthermore, the ultrasonic dispersion machine Disperse for 1 minute to prepare a sample dispersion.
Measurement conditions: Add the sample dispersion to 100 mL of the electrolytic solution so that the particle size of 30,000 particles can be measured in 20 seconds, measure 30,000 particles, and determine the volume from the particle size distribution. Determine the median particle size ( _D50 ).

Resin production example 1
Raw material monomers for amorphous polyester resin other than trimellitic anhydride and an esterification catalyst shown in Table 1 were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer and a thermocouple, and After reacting at ℃ for 12 hours, the mixture was reacted at 8.3 kPa for 1 hour. The temperature was lowered to 160° C., and the raw material monomer for the styrene resin, the bi-reactive monomer and dicumyl peroxide were added dropwise from the dropping funnel over 1 hour. After aging the addition polymerization reaction for 1 hour while maintaining the temperature at 160° C., the temperature was raised to 210° C. and the raw material monomer of the styrene resin was removed for 1 hour at 8.3 kPa. Furthermore, trimellitic anhydride was added at 210° C. and reacted until a desired softening point was reached to obtain amorphous composite resins (resins H1 and H2). Table 1 shows the physical properties of the obtained resin.

Resin production example 2
An alcohol component, a carboxylic acid component other than trimellitic anhydride, and an esterification catalyst shown in Table 2 were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer and a thermocouple, and placed in a nitrogen atmosphere. Then, the temperature was raised to 200° C. and the reaction was carried out for 6 hours. After further raising the temperature to 210°C, trimellitic anhydride was added, reacted at normal pressure (101.3 kPa) for 1 hour, and further reacted at 40 kPa until the desired softening point was reached to obtain an amorphous polyester resin. (Resins A1 to A3) were obtained. Table 2 shows the physical properties of the obtained resin.

Resin production example 3
An alcohol component, a carboxylic acid component other than trimellitic anhydride, an esterification catalyst, and a polymerization inhibitor shown in Table 2 were added to a 10-liter four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple. The temperature was raised to 200° C. under a nitrogen atmosphere, and the reaction was allowed to proceed for 6 hours. After further raising the temperature to 210°C, trimellitic anhydride was added, reacted at normal pressure (101.3 kPa) for 1 hour, and further reacted at 40 kPa until the desired softening point was reached to obtain an amorphous polyester resin. (Resin A4) was obtained. Table 2 shows the physical properties of the obtained resin.

Resin production example 4
The raw material monomers for the crystalline polyester resin shown in Table 3 and the esterification catalyst were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer and a thermocouple, and heated to 160°C. reacted over time. After that, the raw material monomer for the styrenic resin and the bi-reactive monomer shown in Table 3 were added dropwise from the dropping funnel over 1 hour. After aging the addition polymerization reaction for 1 hour while maintaining the temperature at 160° C., the raw material monomer of the styrene resin was removed for 1 hour at 8.3 kPa. Further, the temperature was raised to 200° C. over 8 hours, and the mixture was reacted at 8.3 kPa for 2 hours to obtain crystalline composite resins (resins C1 and C2). Table 3 shows the physical properties of the obtained resin.

Resin production example 5
The raw material monomers for the crystalline polyester resin, the esterification catalyst, and the polymerization inhibitor shown in Table 3 were placed in a 10-liter four-necked flask equipped with a nitrogen inlet tube, a dehydration tube, a stirrer, and a thermocouple, and placed under a nitrogen atmosphere. , the temperature was raised from 130°C to 200°C over 10 hours, and the mixture was reacted at 200°C at 8 kPa for 1 hour to obtain a crystalline polyester resin (resin C3). Table 3 shows the physical properties of the obtained resin.

Examples 1-18
Amorphous resin and release agent (Example 15 only) supplied from raw material supply port F1 shown in Tables 4 and 5, and negative charge control agent "Bontron E-304" (manufactured by Orient Chemical Industry Co., Ltd.) 1.0 mass and 6.0 parts by mass of a coloring agent "REGAL330R" (manufactured by Cabot Specialty Chemicals, Inc.) were mixed for 2 minutes using a Henschel mixer to obtain a raw material mixture supplied from the raw material supply port F1.

The amorphous resin (only Example 6), the crystalline polyester resin, and the release agent supplied from the raw material supply port F2 shown in Tables 4 and 5 were mixed for 2 minutes using a Henschel mixer, and the raw material supply port F2 was mixed. A raw material mixture supplied from

The raw material mixture thus obtained was supplied to a co-rotating twin-screw extruder "PCM-43" (manufactured by Ikegai Iron Works Co., Ltd., shaft diameter 4.2 cm) through raw material supply ports F1 and F2, respectively, and melt-kneaded.
The length L of the barrel of the secondary extruder is 1600 mm, the raw material supply port F1 is located at a position of 75 mm (0.05 L) from the entrance side end of the barrel, the raw material supply port F2 is located at a position of 695 mm (0.43 L), The kneaded material discharge port was installed at a position of 1560 mm (0.98 L).
The operating conditions of the twin-screw extruder are as follows: barrel setting temperature 120°C, shaft rotation speed 150 r/min, mixture supply speed from raw material supply ports F1 and F2, raw material with desired composition ratio kneaded product discharge speed 20 kg Adjusted to be /h.

The resulting kneaded product was cooled and coarsely pulverized using a pulverizer “Rotoplex” (manufactured by Hosokawa Micron Corporation) to obtain a coarsely pulverized product having a volume particle size of 2 mm or less using a sieve with an opening of 2 mm. The obtained coarsely pulverized material was finely pulverized by adjusting the pulverization pressure so that the volume-median particle diameter was 7.0 μm using a DS2 type air classifier (collision plate type, manufactured by Nippon Pneumatic Co., Ltd.). The resulting finely pulverized product was classified using a DSX2 type air classifier (manufactured by Nippon Pneumatic Co., Ltd.) by adjusting the static pressure (internal pressure) so that the volume median particle size was 7.5 μm. got

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) and hydrophobic silica "RY- 50" (Nippon Aerosil Co., Ltd., hydrophobizing agent: silicone oil, average particle size: 40 nm) is mixed for 3 minutes at 2100 r/min (peripheral speed: 29 m/sec) in a Henschel mixer (manufactured by Mitsui Mining Co., Ltd.). and got the toner.

Comparative Examples 1-3
Using the binder resins and release agents shown in Tables 4 and 5, these were mixed with 1.0 parts by mass of a negative charge control agent "Bontron E-304" (manufactured by Orient Chemical Industry Co., Ltd.) and a coloring agent "REGAL330R" (Cabot Specialty). A toner was obtained in the same manner as in Example 1, except that the mixture was mixed with 6.0 parts by mass of T. Chemicals, Inc. using a Henschel mixer for 2 minutes and supplied to the twin-screw extruder through the raw material supply port F1. .

Test Example 1 [low-temperature fixability]
A printer "OKI MICROLINE 5400" (manufactured by Oki Data Co., Ltd.) modified to print unfixed images was filled with toner, and unfixed solid images of 2 cm square were printed. Using an external fixing device modified from a printer "OKI MICROLINE 3010" (manufactured by Oki Data Co., Ltd.), the temperature of the fixing roll was changed from 100°C to 200°C by 5°C at a rotation speed of 180 mm/sec. This unfixed image was subjected to fixing treatment at each temperature while increasing the temperature to obtain a fixed image. The image obtained at each fixing temperature is rubbed 5 times back and forth with a sand eraser (ER-502R, manufactured by LION) with a load of 500g. company), and the temperature at which the image density ratio before and after rubbing ([image density after rubbing / image density before rubbing] x 100) first exceeds 85% is taken as the lowest fixing temperature. used as an index. The lower the minimum fixing temperature, the better the low-temperature fixability. Tables 4 and 5 show the results.

Test Example 2 [Hot offset (HO) resistance]
In the same manner as in Test Example 1, an unfixed solid image of 2 cm square was printed. Using an external fixing device modified from a printer "OKI MICROLINE 3010" (manufactured by Oki Data Co., Ltd.), the temperature of the fixing roll was changed from 100°C to 200°C by 5°C at a rotation speed of 90 mm/sec. This unfixed image was subjected to fixing treatment at each temperature while increasing the temperature to obtain a fixed image. The resulting fixed image was visually observed, and the maximum temperature of the fixing roll at which hot offset was not observed was defined as the maximum fixing temperature. The higher the temperature, the better the hot offset resistance. Tables 4 and 5 show the results.

Test Example 3 [Durability]
120 g of toner was mounted in a non-magnetic one-component developing device "MICROLINE 5400" (manufactured by Oki Data Co., Ltd.), and a durability test was conducted at 30°C and 80% humidity at a printing rate of 3%. A solid image was printed every 500 sheets, and it was observed whether there were any printing defects, specifically white streaks or fading that made the white background of the paper visible. The test was stopped when printing defects were confirmed. . The greater the number of printed sheets until the occurrence of printing defects, the better the durability. Tables 4 and 5 show the results.

From the above results, in comparison with Comparative Examples 1 to 3 in which all the raw materials were supplied to the twin-screw kneader at once, the toners of Examples 1 to 18 exhibited excellent low temperature fixability, hot offset resistance, and durability. It can be seen that it is also excellent in

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

Claims (6)

A method for producing a toner for electrostatic charge image development, comprising a step of melt-kneading a mixture of raw materials containing an amorphous resin, a crystalline polyester resin, and a release agent using a twin-screw extruder, wherein the twin-screw extrusion When the length of the barrel of the machine is L, one or more raw material supply ports are provided at a position f1 less than 0.3L from the inlet side end of the barrel and at a position f2 at 0.3L or more and 0.9L or less, said f1 a raw material containing an amorphous resin is supplied from the raw material supply port F1 of f2, and a raw material containing a crystalline polyester resin and a release agent is supplied from the raw material supply port F2 of f2. . 2. The production method according to claim 1, wherein the crystalline polyester resin supplied from the raw material supply port F2 accounts for 60 mass % or more of the crystalline polyester resin contained in the toner. 3. The manufacturing method according to claim 1, wherein the amorphous resin supplied from the raw material supply port F1 accounts for 60 mass % or more of the amorphous resin contained in the toner. 4. The production method according to any one of claims 1 to 3, wherein the release agent supplied from the raw material supply port F2 accounts for 60% by mass or more of the release agent contained in the toner. Claim 1, wherein the total amount of the amorphous resin and the crystalline polyester resin supplied from the raw material supply port F2 is less than 50% by mass of the total amount of the amorphous resin and the crystalline polyester resin contained in the toner. 4. The production method according to any one of 4. The production method according to any one of claims 1 to 5, wherein the total amount of the crystalline polyester resin and the release agent is 5 parts by mass or more and 40 parts by mass or less with respect to 100 parts by mass of the amorphous resin.