JP7428001B2 - Toner for developing electrostatic images and method for producing the same - Google Patents

Description

The present invention relates to a toner for developing electrostatic images and a method for producing the same, and more specifically, the present invention relates to a toner for developing electrostatic images and a method for producing the same. This invention relates to toner for developing charged images.

In the printing field where images are formed using electrophotography, in recent years electrostatic image development has been developed which can reduce power consumption, speed up printing, diversify image forming media, improve image quality, and reduce environmental impact. There is a demand for toner for use in the printing press (hereinafter also simply referred to as "toner"). Characteristics required of such toners include so-called low-temperature fixability, in which toner images can be fixed at lower temperatures than conventional ones, and improvement in fixing strength. Furthermore, with the expansion of the light printing market beyond the traditional office market, there is a demand for toners that can not only print on existing paper but also have excellent fixation properties on films such as polypropylene and polyethylene terephthalate. There is.

Toners usually contain a binder resin (toner binder) that has a binder function, and this binder resin may be a hybrid resin such as a styrene-acrylic resin, a polyester resin, or a polyester resin having grafted acrylic polymerized segments. known to be used. In response to the above-mentioned demands, techniques are known to improve low-temperature fixability by improving these toner binders (see, for example, Patent Documents 1 to 3).

In general, compared to polyester resins, styrene/acrylic resins can be synthesized at lower temperatures and can be manufactured in an aqueous medium from monomer polymerization to toner particle formation, which is advantageous in terms of productivity. It has the advantage of being However, when a polyethylene terephthalate film with a thickness of 200 μm is used as a recording medium, for example, it has disadvantages such as poorer adhesion to the film than toner using polyester resin, and has excellent productivity. It has been difficult to produce toner with excellent low-temperature fixability.

Furthermore, many toners contain a release agent (wax) inside the toner in order to ensure releasability from the fixing roller when fixing to paper. It melts due to the heat during fixing and oozes out to the toner surface due to pressure. Due to the low surface energy of the release agent, it is possible to reduce the adhesive force between the toner and the fixing roller, and as a result, the paper It is possible to obtain an image in which the toner is fixed to the paper without getting wrapped around the fixing roller.

On the other hand, as the melt viscosity of the resin decreases with low-temperature fixing, it is necessary to add a large amount of mold release agent. There were problems related to the fixing strength, such as the fixed image being destroyed and peeled off due to stress concentration. To address this problem, efforts have been made to provide an intermediate layer between the toner and the film to prevent peeling (see, for example, Patent Document 4). However, even with this method, hot offset resistance and fixing strength were not sufficient.

Japanese Patent Application Publication No. 2007-279714 Japanese Patent Application Publication No. 2008-287229 Japanese Patent Application Publication No. 2010-15159 JP2005-258390A

The present invention was made in view of the above-mentioned problems and circumstances, and the problem to be solved is to achieve good fixing strength when using a flexible base material such as a film while satisfying hot offset resistance. It is an object of the present invention to provide a toner for developing an electrostatic image that retains moisture and a method for producing the same.

In order to solve the above problem, the present inventor discovered that in the process of studying the causes of the above problem, it was discovered that toner particles contain a polymer having a specific structural unit and a specific release agent as a binder resin. The inventors have now discovered that it is possible to obtain a toner for developing electrostatic images that satisfies hot offset resistance and can achieve good fixing strength when used on a flexible substrate such as a film.

That is, the above-mentioned problems related to the present invention are solved by the following means.

（式中Ｒ_１は、水素原子又は炭素数が１～４のアルキル基を表す。Ｒ_２及びＲ_３は、それぞれ独立に水素原子、炭素数が１～４のアルキル基又はアルコキシ基を表す。Ｒ_４は、水素原子、炭素数が１～４のアルキル基、炭素数が１～４のアルコキシ基、カルボキシ基、又は炭素数２～５のエステル基を表す。） 1. A toner for developing an electrostatic image containing toner particles,
The toner particles contain a polymer having a structural unit represented by the following general formula (1) as a binder resin, and a fatty acid ester wax as a release agent,
A toner for developing an electrostatic image , wherein the fatty acid ester wax contains a fatty acid ester wax using a fatty acid having 18 to 24 carbon atoms .

(In the formula, R ₁ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. _{R 2} and R ₃ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group. R ₄ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a carboxy group, or an ester group having 2 to 5 carbon atoms.)

(In the formula, R ₁ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. _{R 2} and R ₃ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group. R ₄ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a carboxy group, or an ester group having 2 to 5 carbon atoms.)

2. 2. The toner for developing an electrostatic image according to item 1, wherein R ₁ is a hydrogen atom or a methyl group.

3. The toner for developing an electrostatic image according to item 1 or 2, wherein R ₂ and R ₃ are methoxy groups.

4. The toner for developing an electrostatic image according to item 1 or 2, wherein one of R ₂ and R ₃ is a methoxy group and the other is a hydrogen atom.

5. The toner for developing an electrostatic image according to item 1 or 2, wherein R ₂ and R ₃ are hydrogen atoms.

6. The toner for developing an electrostatic image according to any one of Items 1 to 5, wherein R ₄ is a hydrogen atom, a carboxy group, or an ester group having 2 to 5 carbon atoms.

7. A polymer having a structural unit represented by the general formula (1) has a first polymerizable monomer represented by the following general formula (2) and a second polymerizable monomer other than the first polymerizable monomer. The toner for developing an electrostatic image according to any one of Items 1 to 6, which is a copolymer with a polymerizable monomer.

(In the formula, R ₁ to R ₄ have the same meanings as R ₁ to R ₄ in the above general formula (1).)

8. Item 7, wherein the second polymerizable monomer is at least one selected from acrylic acid, n-butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid, and methyl methacrylate. The toner for developing electrostatic images described above.

9 . 9. The toner for developing an electrostatic image according to any one of Items 1 to 8 , wherein the fatty acid ester wax contains behenyl behenate or pentaerythritol tetrabehenate.

10 . The electrostatic image forming apparatus according to any one of items 1 to 9 , wherein the content of the fatty acid ester wax in the electrostatic image developing toner is in the range of 5 to 25% by mass. Toner for developing charged images.

（式中Ｒ _１ は、水素原子又は炭素数が１～４のアルキル基を表す。Ｒ _２ 及びＲ _３ は、メトキシ基であるか、又は、Ｒ _２ 及びＲ _３ の一方がメトキシ基であり、他方が水素原子である。Ｒ _４ は、水素原子、炭素数が１～４のアルキル基、炭素数が１～４のアルコキシ基、カルボキシ基、又は炭素数２～５のエステル基を表す。）
１２．少なくとも結着樹脂と離型剤よりなるトナー粒子を含有する静電荷像現像用トナーの製造方法であって、
前記結着樹脂として、下記一般式（１）で表される構造単位を有する重合体を、下記一般式（２）で表される重合性単量体を用いてラジカル重合により合成する工程と、
前記離型剤が、炭素数１８～２４の脂肪酸を用いた脂肪酸エステル系ワックスであり、
前記脂肪酸エステル系ワックスが、ベヘン酸ベヘニル又はペンタエリスリトールテトラベヘン酸エステルを含有し、
前記結着樹脂と前記離型剤とを混合する工程と、
を有することを特徴とする静電荷像現像用トナーの製造方法。 11. A toner for developing an electrostatic image containing toner particles,
For electrostatic image development, wherein the toner particles contain a polymer having a structural unit represented by the following general formula (1) as a binder resin, and a fatty acid ester wax as a release agent. toner.

(In the formula, R ₁ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ₂ and R ₃ are a methoxy group, or one of R ₂ and R ₃ is a methoxy group, The other is a hydrogen atom. R ₄ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a carboxy group, or an ester group having 2 to 5 carbon atoms.)
12. A method for producing an electrostatic image developing toner containing toner particles comprising at least a binder resin and a release agent, the method comprising:
A step of synthesizing, as the binder resin, a polymer having a structural unit represented by the following general formula (1) by radical polymerization using a polymerizable monomer represented by the following general formula (2);
The mold release agent is a fatty acid ester wax using a fatty acid having 18 to 24 carbon atoms,
The fatty acid ester wax contains behenyl behenate or pentaerythritol tetrabehenate,
mixing the binder resin and the mold release agent;
A method for producing a toner for developing an electrostatic image, comprising:

(In the formula, R ₁ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. _{R 2} and R ₃ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group. R ₄ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a carboxy group, or an ester group having 2 to 5 carbon atoms.)

(In the formula, R ₁ to R ₄ have the same meanings as R ₁ to R ₄ in the above general formula (1).)

By the above-mentioned means of the present invention, there is provided a toner for developing an electrostatic image that can achieve good fixing strength when using a flexible base material such as a film while satisfying hot offset resistance, and a method for producing the same. Can be done.

Although the details of whether the toner for developing an electrostatic image of the present invention achieves the above effects are not clear, the following mechanism is considered. Note that the mechanism described below is based on speculation, and the present invention is not limited to the mechanism described below. In the following description, the polymer having the structural unit represented by the above general formula (1) is also simply referred to as "the polymer according to the present invention."

Conventional toners containing styrene/acrylic resin contain as a main component a polymer containing a styrene unit (structural unit) derived from styrene, which has relatively high hydrophobicity. Moreover, paraffin and fatty acid ester are mainly used as mold release agents. To fix toner at a low temperature, it is necessary to lower the melt viscosity of the resin component, and lowering the molecular weight is the main direction. An offset will occur.

One possible solution to this problem is to add a large amount of release agent, but adding a large amount of incompatible components causes further incompatibility, creating a large domain of release agent inside the toner. It forms. When strain is applied to such a resin-release agent interface, stress is locally concentrated, and the fixed image is easily destroyed.

On the other hand, it is presumed that stress concentration can be dispersed by reducing the domain size. Reducing the domain size is more preferable for fatty acid esters than paraffins because they have a greater interaction with the resin, but this alone is not sufficient to achieve the desired performance.

Under these circumstances, the present inventors introduced an ester structure into the styrene unit, which is the main component of the resin, to increase the interaction with the fatty acid ester of the mold release agent and thereby reduce the domain size. It has been found that it is possible to significantly reduce the size. By reducing the domain size, stress concentration is dispersed and destruction does not occur when subjected to strain, resulting in improved hot offset resistance and fixing strength to flexible substrates such as films. Guessed.

The toner for developing an electrostatic image of the present invention is a toner for developing an electrostatic image containing toner particles, wherein the toner particle has a structural unit represented by the general formula (1) as a binder resin. It is characterized by containing a polymer and a fatty acid ester wax as a mold release agent. This feature is a technical feature common to or corresponding to the embodiments described below.

In an embodiment of the present invention, from the viewpoint of achieving the effects of the present invention, R ₁ in general formula (1) is a hydrogen atom or a methyl group, and R ₂ and R ₃ are methoxy groups. In particular, one of R ₂ and R ₃ is a methoxy group and the other is a hydrogen atom, furthermore, R ₂ and R ₃ are hydrogen atoms, and R ₄ is a hydrogen atom. A preferred structure is an atom, a carboxy group, or an ester group having 2 to 5 carbon atoms, from the viewpoint of improving hot offset resistance and reducing the domain size to improve fixing strength to a flexible substrate. It is.

The polymer having the structural unit represented by the general formula (1) includes a first polymerizable monomer represented by the general formula (2) and a second polymerizable monomer other than the first polymerizable monomer. A copolymer with a polymerizable monomer is preferred.

Further, it is preferable that the second polymerizable monomer is at least one selected from acrylic acid, n-butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid, or methyl methacrylate.

Further, it is preferable that the fatty acid ester wax is a fatty acid ester wax using a fatty acid having 18 to 24 carbon atoms, and that the fatty acid ester wax contains behenyl behenate or pentaerythritol tetrabehenate ester. This is a preferred embodiment from the viewpoint of improving the fixing strength to a flexible base material by reducing the size.

The content of the fatty acid ester wax in the electrostatic image developing toner is within the range of 5 to 25% by mass from the viewpoint of functioning as a mold release agent and suppressing destruction when subjected to strain. , is within a preferable content range.

The method for producing a toner for developing an electrostatic image of the present invention includes a method for producing a toner for developing an electrostatic image by using a polymer having a structural unit represented by the general formula (1) and a polymerizable monomer represented by the general formula (2). The mold release agent is a fatty acid ester wax using a fatty acid having 18 to 24 carbon atoms, and the mold release agent is mixed with the binder resin and the mold release agent. It is characterized by

The fatty acid ester wax is preferably behenyl behenate or pentaerythritol tetrabehenate ester.

Hereinafter, the present invention, its constituent elements, and forms and aspects for carrying out the present invention will be described in detail. In this application, "~" is used to include the numerical values described before and after it as a lower limit value and an upper limit value.

≪Overview of the toner for developing electrostatic images of the present invention≫
The toner for developing an electrostatic image of the present invention is a toner for developing an electrostatic image containing toner particles, wherein the toner particle has a structural unit represented by the following general formula (1) as a binder resin. It is characterized by containing a fatty acid ester wax as a polymer and a mold release agent.

In this specification, "toner base particles" constitute the base of "toner particles." The "toner base particles" contain at least a binder resin and a release agent, and may also contain other components such as a colorant and a charge control agent, if necessary. The "toner base particles" are called "toner particles" by adding external additives. The term "toner" refers to an aggregate of "toner particles." Further, the "toner for developing an electrostatic image" of the present invention is also simply referred to as "toner".

[1] Composition of Toner [1.1] Binder Resin The binder resin according to the present invention contains a polymer having a structural unit represented by the following general formula (1).

(In the formula, R ₁ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. _{R 2} and R ₃ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group. R ₄ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a carboxy group, or an ester group having 2 to 5 carbon atoms.)
R ₁ in the above general formula (1) is a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. The alkyl group having 1 to 4 carbon atoms may be linear or branched, and specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, and isobutyl group. , sec-butyl group, tert-butyl group, etc.

R ₂ and R ₃ in the above general formula (1) are each independently a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group having 1 to 4 carbon atoms. The alkyl group having 1 to 4 carbon atoms may be linear or branched, and specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, and isobutyl group. , sec-butyl group, tert-butyl group, etc. The alkoxy group having 1 to 4 carbon atoms may be linear or branched, and specific examples thereof include methoxy group, ethoxy group, n-propyloxy group, isopropyloxy group, n-butyloxy group, Examples include sec-butyloxy group and tert-butyloxy group.

R ₄ in the above general formula (1) is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a carboxy group, or an ester group having 2 to 5 carbon atoms. The alkyl group having 1 to 4 carbon atoms may be linear or branched, and specific examples thereof include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, and isobutyl group. , sec-butyl group, tert-butyl group, etc. The alkoxy group having 1 to 4 carbon atoms may be linear or branched, and specific examples thereof include methoxy group, ethoxy group, n-propyloxy group, isopropyloxy group, n-butyloxy group, Examples include sec-butyloxy group and tert-butyloxy group. The ester group having 2 to 5 carbon atoms may be either linear or branched, and specific examples include methyloxycarbonyl group, propionyloxycarbonyl group, and the like.

The content of the structural unit represented by general formula (1) in the polymer is preferably 60 to 100% by mass, more preferably 65 to 100% by mass.

The polymer having the structural unit represented by the general formula (1) according to the present invention is a monomer represented by the following general formula (2) (hereinafter also referred to as the first polymerizable monomer). It can be synthesized by polymerization.

(In the formula, R ₁ to R ₄ have the same meanings as R ₁ to R ₄ in the above general formula (1).)
This first polymerizable monomer can be used alone or in combination of two or more. Specific examples of the first polymerizable monomer include the following exemplary compounds M1 to M11.

The first polymerizable monomer may be a commercially available product or a synthetic product. As an example of the synthesis method, the first polymerizable monomer having various functional groups can be synthesized by using phenol, 4-hydroxybenzoic acid, etc. as a starting material and carrying out an esterification reaction.

The method of polymerizing the first polymerizable monomer is not particularly limited, but from the viewpoint of easy synthesis, a method of radically polymerizing the monomer using a known oil-soluble or water-soluble radical polymerization initiator is preferred. That is, the manufacturing method according to a preferred embodiment of the present invention includes a binder resin containing a polymer having a structural unit represented by the above general formula (1), and a static resin containing a mold release agent containing a fatty acid ester wax. A method for producing a toner for developing a charge image, comprising the steps of performing radical polymerization of a polymerizable monomer represented by the above general formula (2) to synthesize the polymer, and the binder resin and the mold release. and a step of mixing with the agent.

Specific examples of oil-soluble polymerization initiators used in radical polymerization include azo or diazo polymerization initiators and peroxide polymerization initiators shown below. If necessary, for example, known chain transfer agents such as n-octylmercaptan and n-octyl-3-mercaptopropionate may be used.

Examples of azo or diazo polymerization initiators include 2,2'-azobis-(2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, and 1,1'-azobis(cyclohexane). -1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, and azobisisobutyronitrile.

Examples of peroxide polymerization initiators include benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxy carbonate, cumene hydroperoxide, t-butyl hydroperoxide, di-t-butyl peroxide, dicumyl peroxide, Examples include 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, 2,2-bis-(4,4-t-butylperoxycyclohexyl)propane, and tris-(t-butylperoxy)triazine.

Furthermore, when forming the polymer according to the present invention by emulsion polymerization, a water-soluble radical polymerization initiator can be used. Examples of the water-soluble radical polymerization initiator include persulfates such as potassium persulfate and ammonium persulfate, azobisminodipropane acetate, azobiscyanovaleric acid and its salts, and hydrogen peroxide.

The polymerization temperature varies depending on the type of monomer and polymerization initiator used, but is preferably 50 to 100°C, more preferably 55 to 90°C. Further, the polymerization time varies depending on the type of monomer and polymerization initiator used, but is preferably 1 to 12 hours, for example.

<Other structural units>
The polymer according to the present invention may be a polymer obtained only from a polymerizable monomer (first polymerizable monomer) having a structural unit represented by the above general formula (1), but the polymer according to the present invention From the viewpoint of exhibiting the effect even more efficiently, the following polymerizable monomers are copolymerizable with other polymerizable monomers (also referred to as second polymerizable monomers). A copolymer is preferred.

Examples of the second polymerizable monomer include styrene, α-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, o-ethylstyrene, m-ethylstyrene, p-ethylstyrene, Styrenic monomers other than the first polymerizable monomer such as o-acetoxystyrene, m-acetoxystyrene, p-acetoxystyrene; methyl acrylate, ethyl acrylate, isopropyl acrylate, n-butyl acrylate, Acrylic acid esters such as tert-butyl acrylate, isobutyl acrylate, n-octyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, phenyl acrylate; methyl methacrylate, ethyl methacrylate, methacrylic acid n-butyl, isopropyl methacrylate, isobutyl methacrylate, tert-butyl methacrylate, n-octyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, methacrylic acid Methacrylic acid esters such as diethylaminoethyl; and the like. Among these, from the viewpoint of facilitating adjustment of the glass transition temperature of the polymer, at least one selected from the group consisting of acrylic esters and methacrylic esters is preferable, and n-butyl acrylate, 2-acrylic acid At least one selected from the group consisting of ethylhexyl and methyl methacrylate is more preferred, and at least one of n-butyl acrylate and 2-ethylhexyl acrylate is even more preferred.

Furthermore, a polymerizable monomer having an ionic dissociative group may be used as the second polymerizable monomer. The polymerizable monomer having an ionic dissociative group includes, for example, a carboxy group, a sulfonic acid group, a phosphoric acid group, or the like. Specific examples include acrylic acid, methacrylic acid, maleic acid, itaconic acid, and fumaric acid. Among these, acrylic acid or methacrylic acid is preferred.

These second polymerizable monomers can be used alone or in combination of two or more.

In the polymer according to the present invention, the content of the structural unit derived from the second polymerizable monomer is not particularly limited, and can be appropriately adjusted depending on the type of the structural unit. For example, when the second polymerizable monomer is the above-mentioned styrene monomer, the content of structural units derived from the styrene monomer in the polymer is 100% by mass of all structural units of the polymer. The content is preferably 0 to 50% by mass, more preferably 0 to 40% by mass.

When the second polymerizable monomer is an acrylic ester or a methacrylic ester, the content of structural units derived from the acrylic ester or methacrylic ester in the polymer is 100% by mass of all structural units of the polymer. The amount is preferably 10 to 50% by weight, more preferably 20 to 40% by weight.

When using a polymerizable monomer having an ionic dissociative group, the content of its structural units is preferably 3 to 8% by mass, based on 100% by mass of all structural units of the polymer.

The method for synthesizing the polymer according to the present invention using the first polymerizable monomer and the second polymerizable monomer is the same as the method for polymerizing the first polymerizable monomer explained above. Therefore, the explanation is omitted here.

The polymer according to the present invention preferably has a peak molecular weight of 3,500 to 35,000, preferably 10,000 to 30 ,000 is more preferable. A peak molecular weight within such a range is preferable because the polymer has an appropriate melt viscosity during fixing, making it possible to achieve both good fixing properties and anti-offset properties.

Note that the peak molecular weight is a molecular weight corresponding to the elution time of the peak top in the molecular weight distribution. When multiple peaks exist in the molecular weight distribution, it refers to the molecular weight corresponding to the elution time of the peak top with the largest peak area ratio.

The peak molecular weight of a polymer can be measured by the following method. Specifically, an apparatus "HLC-8220" (manufactured by Tosoh Corporation) and a column "TSKguardcolumn+TSKgelSuperHZM-M triple series" (manufactured by Tosoh Corporation) were used, and while the column temperature was maintained at 40°C, tetrahydrofuran (THF) was used as a carrier solvent. ) at a flow rate of 0.2 ml/min, and the measurement sample is dissolved in tetrahydrofuran at a concentration of 1 mg/ml under dissolution conditions of 5 minutes treatment using an ultrasonic disperser at room temperature (25° C.). Next, a sample solution was obtained by processing with a membrane filter with a pore size of 0.2 μm, and 10 μl of this sample solution was injected into the device together with the above carrier solvent, and detected using a refractive index detector (RI detector), and measured. It is measured from the molecular weight distribution of the sample.

The content ratio of the polymer according to the present invention is 65% by mass based on the total mass of the polymer according to the present invention and the mold release agent as 100% from the viewpoint of the balance of crease fixing properties, anti-offset properties, and varnish adhesion. It is preferably in the range of ~99% by weight, more preferably in the range of 70-97% by weight, even more preferably in the range of 75-95% by weight.

<Other resins>
The binder resin may contain other resins than the polymer according to the present invention, and resins that are generally used as binder resins constituting toners can be used without limitation. Specific examples include polyester resin, silicone resin, polyolefin resin, polyamide resin, and epoxy resin. These other resins can be used alone or in combination of two or more.

Below, a polyester resin that can be used as a binder resin will be explained.

(polyester resin)
The polyester resin is a known polyester resin obtained by a polycondensation reaction between a dihydric or higher carboxylic acid (polyhydric carboxylic acid component) and a divalent or higher alcohol (polyhydric alcohol component). Note that the polyester resin may be amorphous or crystalline.

The valences of the polyhydric carboxylic acid component and the polyhydric alcohol component are preferably 2 to 3, and particularly preferably 2. Therefore, a particularly preferred form is when the valence is 2 (i.e., dicarboxylic acid component and polyhydric alcohol component). (acid component, diol component) will be explained.

Examples of dicarboxylic acid components include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, 1,9-nonanedicarboxylic acid, and 1,10-decanedicarboxylic acid. (dodecanedioic acid), 1,11-undecanedicarboxylic acid, 1,12-dodecanedicarboxylic acid, 1,13-tridecanedicarboxylic acid, 1,14-tetradecanedicarboxylic acid, 1,16-hexadecanedicarboxylic acid, 1,18 - Saturated aliphatic dicarboxylic acids such as octadecanedicarboxylic acid; unsaturated aliphatic dicarboxylic acids such as methylenesuccinic acid, fumaric acid, maleic acid, 3-hexenedioic acid, 3-octenedioic acid, dodecenylsuccinic acid; phthalic acid, Terephthalic acid, isophthalic acid, t-butyl isophthalic acid, tetrachlorophthalic acid, chlorophthalic acid, nitrophthalic acid, p-phenylene diacetic acid, 2,6-naphthalene dicarboxylic acid, 4,4'-biphenyl dicarboxylic acid, anthracene dicarboxylic acid, etc. unsaturated aromatic dicarboxylic acids; and the like, and lower alkyl esters and acid anhydrides thereof can also be used. The dicarboxylic acid components may be used alone or in combination of two or more.

In addition, trivalent or higher polycarboxylic acids such as trimellitic acid and pyromellitic acid, anhydrides of the above-mentioned carboxylic acid compounds, or alkyl esters having 1 to 3 carbon atoms can also be used.

Examples of the diol component include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,7-heptanediol. Diol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,13-tridecanediol, 1,14-tetradecane Saturated aliphatic diols such as diol, 1,18-octadecanediol, 1,20-eicosandiol, neopentyl glycol; 2-butene-1,4-diol, 3-butene-1,4-diol, 2-butyne -Unsaturated aliphatic diols such as -1,4-diol, 3-butyne-1,4-diol, and 9-octadecene-7,12-diol; bisphenols such as bisphenol A and bisphenol F, and their addition with ethylene oxide Examples include aromatic diols such as alkylene oxide adducts of bisphenols, such as bisphenols and propylene oxide adducts, and derivatives thereof can also be used. The diol components may be used alone or in combination of two or more.

The method for producing the polyester resin is not particularly limited, and it can be produced by polycondensing (esterifying) the polyhydric carboxylic acid component and the polyhydric alcohol component using a known esterification catalyst.

Catalysts that can be used in the production of polyester resin include alkali metal compounds such as sodium and lithium; compounds containing Group 2 elements such as magnesium and calcium; aluminum, zinc, manganese, antimony, titanium, tin, zirconium, Examples include metal compounds such as germanium; phosphorous acid compounds; phosphoric acid compounds; and amine compounds. Specifically, examples of the tin compound include dibutyltin oxide (dibutyltin oxide), tin octylate, tin dioctylate, and salts thereof. Examples of titanium compounds include titanium alkoxides such as tetra-n-butyl titanate (Ti(O-n-Bu) ₄ ), tetraisopropyl titanate, tetramethyl titanate, and tetrastearyl titanate; titanium acylates such as polyhydroxy titanium stearate; titanium tetra Examples include titanium chelates such as acetylacetonate, titanium lactate, and titanium triethanolaminate. Examples of germanium compounds include germanium dioxide and the like. Furthermore, examples of the aluminum compound include polyaluminum hydroxide, aluminum alkoxide, and tributyl aluminate. These may be used alone or in combination of two or more.

The polymerization temperature is not particularly limited, but is preferably 70 to 250°C. Further, the polymerization time is not particularly limited, but it is preferably 0.5 to 10 hours. During the polymerization, the pressure inside the reaction system may be reduced if necessary.

The polyester resin may be a hybrid polyester resin having a graft copolymer structure of a polyester polymerized segment and a styrene/acrylic polymerized segment graft.

The content of the polymer according to the present invention in the binder resin is preferably more than 50% by mass and 100% by mass or less, more preferably 70 to 100% by mass, with the total mass of the binder resin being 100% by mass.

[1.2] Release Agent The toner of the present invention contains a release agent, and the release agent includes fatty acid ester wax.

Examples of fatty acid ester waxes contained in mold release agents include behenyl behenate (behenyl behenate), stearyl stearate (stearyl stearate), behenyl stearate, stearyl behenate, butyl stearate, propyl oleate, etc. ate, hexadecyl palmitate (hexadecyl palmitate), methyl lignocerate (methyl lignocerate), glycerin monostearate (glyceryl stearate), diglyceryl distearate (diglyceryl distearate), pentaerythritol tetrabehenate (pentaerythritol tetrabehenate), diethylene glycol monostearate, dipropylene glycol distearate, sorbitan monostearate, cholesteryl stearate, trimethylolpropane tribehenate, pentaerythritol diacetate dibehenate, glycerin tribehenate ester, tristearyl trimellitate (tristearyl trimellitate), distearyl maleate, methyl triacontanate (methyl triacontanate), and the like. These fatty acid ester waxes can be used alone or in combination of two or more. Furthermore, these fatty acid ester waxes may be commercially available products or synthetic products.

From the viewpoint of interaction with the polymer according to the present invention and balance of release agent viscosity, the fatty acid ester wax preferably contains a fatty acid ester wax having 18 to 24 carbon atoms. Such fatty acids include stearic acid, arachidic acid, behenic acid, lignoceric acid, and the like.

A more preferred mold release agent is at least one of behenyl behenate (behenyl behenate) and pentaerythritol tetrabehenate (pentaerythritol tetrabehenate ester).

As long as the mold release agent contains fatty acid ester wax, it may contain other waxes other than fatty acid ester wax. Examples of such other waxes include polyolefin waxes such as low molecular weight polyethylene and low molecular weight polypropylene, branched chain hydrocarbon waxes such as microcrystalline wax, long chain hydrocarbon waxes such as paraffin wax, and Sasol wax. waxes, dialkyl ketone waxes such as distearyl ketone, and fatty acid amide waxes such as ethylenediamine behenylamide and trimellitic acid tristearylamide.

The content ratio of the release agent is 1 to 35% by mass, based on the total mass of the polymer according to the present invention and the release agent as 100% from the viewpoint of the balance of crease fixing properties, anti-offset properties, and varnish adhesion. %, more preferably 5 to 25% by weight.

[1.3] Other Components The toner base particles used in the present invention may contain a colorant and a charge control agent, if necessary.

<Colorant>
The toner of the present invention may also contain a colorant. As the colorant, commonly known dyes and pigments can be used.

Coloring agents for obtaining black toner include carbon black, magnetic materials, iron/titanium composite oxide black, etc. Examples of carbon black include channel black, furnace black, acetylene black, thermal black, lamp black, etc. Can be mentioned. Furthermore, examples of the magnetic material include ferrite and magnetite.

As a coloring agent for obtaining a yellow toner, C.I. I. Dyes such as Solvent Yellow 19, Solvent Yellow 44, Solvent Yellow 77, Solvent Yellow 79, Solvent Yellow 81, Solvent Yellow 82, Solvent Yellow 93, Solvent Yellow 98, Solvent Yellow 103, Solvent Yellow 104, Solvent Yellow 112, Solvent Yellow 162; I. Examples include pigments such as Pigment Yellow 14, Pigment Yellow 17, Pigment Yellow 74, Pigment Yellow 93, Pigment Yellow 94, Pigment Yellow 138, Pigment Yellow 155, Pigment Yellow 180, and Pigment Yellow 185.

As a coloring agent for obtaining magenta toner, C.I. I. Dyes such as Solvent Red 1, Solvent Red 49, Solvent Red 52, Solvent Red 58, Solvent Red 63, Solvent Red 111, Solvent Red 122; C.I. I. Examples include pigments such as Pigment Red 5, Pigment Red 48:1, Pigment Red 53:1, Pigment Red 57:1, Pigment Red 122, Pigment Red 139, Pigment Red 144, Pigment Red 149, Pigment Red 166, Pigment Red 177, Pigment Red 178, and Pigment Red 222.

As a coloring agent for obtaining a cyan toner, C.I. I. Dyes such as Solvent Blue 25, Solvent Blue 36, Solvent Blue 60, Solvent Blue 70, Solvent Blue 93, and Solvent Blue 95; C.I. I. Examples include pigments such as Pigment Blue 1, Pigment Blue 7, Pigment Blue 15, Pigment Blue 60, Pigment Blue 62, Pigment Blue 66, and Pigment Blue 76.

Coloring agents for obtaining toners of each color can be used alone or in combination of two or more.

The content of the colorant is preferably 0.5 to 20% by weight, more preferably 2 to 10% by weight, based on the total weight of the toner as 100% by weight.

<Electrical control agent>
The toner according to the present invention may contain a charge control agent. The charge control agent to be used is not particularly limited as long as it is a colorless substance that can impart positive or negative charge through triboelectrification, and various known positive charge control agents and negative charge control agents may be used. A charge control agent having electrostatic properties can be used.

Specifically, examples of positively chargeable charge control agents include nigrosine dyes such as "Nigrosine Base EX" (manufactured by Orient Chemical Industry Co., Ltd.), and "quaternary ammonium salt P-51" (manufactured by Orient Chemical Industry Co., Ltd.). company), quaternary ammonium salts such as "Copy Charge PX VP435" (manufactured by Hoechst Japan), alkoxylated amines, alkylamides, molybdate chelate pigments, and "PLZ1001" (manufactured by Shikoku Kasei Kogyo Co., Ltd.). Examples include imidazole compounds.

In addition, examples of negatively chargeable charge control agents include "Bontron (registered trademark) S-22", "Bontron (registered trademark) S-34", "Bontron (registered trademark) E-81", and "Bontron (registered trademark)". Metal complexes such as "Registered Trademark) E-84" (manufactured by Orient Chemical Industry Co., Ltd.), "Spiron Black TRH" (manufactured by Hodogaya Chemical Industry Co., Ltd.), thioindigo pigments, "Copy Charge NX VP434" ( Quaternary ammonium salts such as "Bontron (registered trademark) E-89" (manufactured by Orient Chemical Industry Co., Ltd.), boron such as "LR147" (manufactured by Nippon Carlit Co., Ltd.) compounds, fluorine compounds such as magnesium fluoride, carbon fluoride, and the like.

In addition to those shown above, metal complexes used as negatively chargeable charge control agents include oxycarboxylic acid metal complexes, dicarboxylic acid metal complexes, amino acid metal complexes, diketone metal complexes, diamine metal complexes, and azo group-containing metal complexes. Those having various structures such as a benzene-benzene derivative skeleton metal complex and an azo group-containing benzene-naphthalene derivative skeleton metal complex can be used.

By configuring the toner particles to contain a charge control agent in this manner, the chargeability of the toner is improved.

The content of the charge control agent in the toner is preferably 0.01 to 30% by mass, more preferably 0.1 to 10% by mass.

The form of the toner base particles according to the present invention is not particularly limited, and examples thereof include a so-called single-layer structure (a homogeneous structure that is not a core-shell type), a core-shell structure, a multilayer structure of three or more layers, a domain-matrix structure, etc. It can take the form of

[2] External additives In order to improve the fluidity, charging properties, cleaning properties, etc. of the toner, external additives such as fluidizing agents and cleaning aids, which are so-called post-processing agents, are added to the toner particles. The toner of the present invention may also be configured as follows.

Examples of external additives include inorganic oxide particles such as silica particles, alumina particles, and titanium oxide particles, inorganic stearate compound particles such as aluminum stearate particles and zinc stearate particles, strontium titanate particles, and zinc titanate particles. Examples include inorganic particles such as inorganic titanic acid compound particles such as. These can be used alone or in combination of two or more.

These inorganic particles may be surface-treated with a silane coupling agent, a titanium coupling agent, a higher fatty acid, a silicone oil, etc. in order to improve heat-resistant storage properties and environmental stability.

The amount of these external additives added is preferably 0.05 to 5 parts by weight, more preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the toner base particles.

[3] Physical properties of toner <Average particle size of toner>
The average particle diameter of the toner is preferably 4 to 10 μm, more preferably 5 to 9 μm, in terms of volume-based median diameter (D50). When the volume-based median diameter (D50) is within the above range, the transfer efficiency is increased, the image quality of halftones is improved, and the image quality of thin lines, dots, etc. is improved.

In the present invention, the volume-based median diameter (D50) of the toner is calculated using a computer system (Beckman Coulter Co., Ltd.) equipped with "Coulter Counter 3" (manufactured by Beckman Coulter Inc.) and data processing software "Software V3.51". It is measured and calculated using a measuring device connected to the

Specifically, 0.02 g of the measurement sample (toner) was mixed with 20 mL of a surfactant solution (for the purpose of dispersing toner particles, for example, a surfactant solution prepared by diluting a neutral detergent containing a surfactant component 10 times with pure water) was used. agent solution) and blended in, ultrasonic dispersion was performed for 1 minute to prepare a toner dispersion liquid, and this toner dispersion liquid was added to the "ISOTON II" (manufactured by Beckman Coulter Co., Ltd.) in the sample stand. Pipette into a beaker with a pipette until the concentration indicated on the measuring device reaches 8%.

By setting the concentration within this range, reproducible measurement values can be obtained. Then, in the measuring device, the number of measured particles is set to 25,000, the aperture diameter is set to 50 μm, the measurement range of 1 to 30 μm is divided into 256, and the frequency value is calculated, and the frequency value is calculated by dividing the measurement range into 256. % particle diameter is defined as the volume-based median diameter (D50).

[4] Method for manufacturing toner The method for manufacturing the toner of the present invention is not particularly limited. For example, a toner can be obtained by melt-kneading the polymer according to the present invention, a mold release agent, and, if necessary, a coloring agent, etc., and then performing pulverization, classification, etc.

In addition, polymer particles are prepared by emulsion polymerization, mini-emulsion polymerization, etc. of the polymerizable monomer in an aqueous medium, and the dispersed particles such as the polymer particles, release agent particles, and colorant particles as necessary are aggregated. The toner can be obtained by an emulsion aggregation method in which the toner is fused. As the emulsion aggregation method, methods described in JP-A-5-265252, JP-A-6-329947, JP-A-9-15904, etc. can be adopted.

Furthermore, a production method using the suspension polymerization method described in JP-A No. 2010-191043 may be used.

Among these, a manufacturing method using an emulsion aggregation method is preferred from the viewpoints that particle size and shape can be easily controlled and energy costs during production can be reduced.

The manufacturing method using such emulsion aggregation method is
(1A) Binder particle dispersion preparation step of preparing a dispersion of binder resin particles (1B) Colorant particle dispersion preparation step of preparing a dispersion of colorant particles (1C) Dispersion of release agent particles (2) A coagulant is added to an aqueous medium in which binder resin particles, colorant particles, and release agent particles are present, and at the same time salting out is progressed. (3) A ripening process to form toner particles by controlling the shape of the aggregated particles (4) Toner particles are filtered from the aqueous medium and separated from the toner particles. Filtration and washing steps to remove surfactants, etc. (5) Drying step to dry the washed toner particles (6) External additive addition step to add external additives to the dried toner particles It is preferable to include. The steps (1A) to (1C) will be explained below.

(1A) Binder resin particle dispersion preparation step In this step, resin particles are formed by conventionally known emulsion polymerization or the like, and the resin particles are agglomerated and fused to form binder resin particles. As an example, a dispersion of binder resin particles is prepared by introducing and dispersing polymerizable monomers constituting the binder resin into an aqueous medium, and polymerizing these polymerizable monomers with a polymerization initiator. .

In addition to the method of polymerizing a polymerizable monomer with a polymerization initiator in an aqueous medium as described above, methods for obtaining a binder resin particle dispersion include, for example, dispersion treatment in an aqueous medium without using a solvent. or a method in which the polymer is dissolved in an organic solvent such as ethyl acetate to form a solution, the solution is emulsified and dispersed in an aqueous medium using a disperser, and then the solvent is removed.

At this time, if necessary, the binder resin may contain a release agent in advance. In addition, for dispersion, polymerization is carried out in the presence of a known surfactant (for example, an anionic surfactant such as polyoxyethylene (2) sodium dodecyl ether sulfate, sodium dodecyl sulfate, sodium dodecylbenzene sulfonate, etc.). It is also preferable.

The volume-based median diameter of the binder resin particles in the dispersion is preferably 50 to 300 nm. The volume-based median diameter of the binder resin particles in the dispersion can be measured by a dynamic light scattering method using "Microtrack UPA-150" (manufactured by Nikkiso Co., Ltd.).

(1B) Colorant particle dispersion preparation step This colorant particle dispersion preparation step is a step in which a colorant is dispersed in the form of fine particles in an aqueous medium to prepare a dispersion of colorant particles.

Dispersion of the colorant can be performed using mechanical energy. The volume-based median diameter of the colorant particles in the dispersion is preferably 10 to 300 nm, more preferably 50 to 200 nm.

The volume-based median diameter of the colorant particles in the dispersion can be measured by the dynamic light scattering method using "Microtrac UPA-150" (manufactured by Nikkiso Co., Ltd.) in the same manner as described above.

(1C) Release agent particle dispersion preparation step This release agent particle dispersion preparation step is a step in which a release agent is dispersed in the form of fine particles in an aqueous medium to prepare a dispersion of release agent particles.

The release agent can be dispersed using mechanical energy. The volume-based median diameter of the release agent particles in the dispersion is preferably 100 to 1000 nm, more preferably 200 to 700 nm.

The volume-based median diameter of the release agent particles in the dispersion can be measured, for example, using a laser diffraction particle size distribution analyzer LA-750 (manufactured by Horiba, Ltd.).

<Aqueous medium>
The aqueous medium used in the steps (1A) to (1C) is water, or has water as the main component (50% by mass or more), water-soluble solvents such as alcohols and glycols, surfactants, dispersants, etc. Examples include aqueous media containing optional components. As the aqueous medium, preferably a mixture of water and a surfactant is used.

Examples of the water-soluble solvent include methanol, ethanol, isopropanol, butanol, acetone, methyl ethyl ketone, and tetrahydrofuran. Among these, alcohols such as methanol, ethanol, isopropanol, and butanol, which are organic solvents that do not dissolve the polymer, are preferred.

Examples of the surfactant include cationic surfactants, anionic surfactants, and nonionic surfactants. Examples of the cationic surfactant include dodecyl ammonium chloride, dodecylammonium bromide, dodecyltrimethylammonium bromide, dodecylpyridinium chloride, dodecylpyridinium bromide, hexadecyltrimethylammonium bromide, and the like. Examples of the anionic surfactant include fatty acid soaps such as sodium stearate and sodium dodecanoate, sodium dodecylbenzenesulfonate, and sodium dodecyl sulfate. Examples of nonionic surfactants include polyoxyethylene dodecyl ether, polyoxyethylene hexadecyl ether, polyoxyethylene nonylphenyl ether, polyoxyethylene lauryl ether, polyoxyethylene sorbitan monooleate ether, and monodecanoyl ether. Examples include sucrose.

Such surfactants can be used alone or in combination of two or more. Among the surfactants, preferably anionic surfactants are used, more preferably sodium dodecylbenzenesulfonate and sodium dodecyl sulfate.

The amount of surfactant added is preferably 0.01 parts by mass or more and 10 parts by mass or less, more preferably 0.04 parts by mass or more and 2 parts by mass or less, per 100 parts by mass of the aqueous medium.

The steps from (2) association step to (6) external additive addition step can be performed according to various conventionally known methods.

The flocculant used in the (2) association step is not particularly limited, but those selected from metal salts are preferably used. Examples of metal salts include monovalent metal salts such as alkali metal salts such as sodium, potassium, and lithium; divalent metal salts such as calcium, magnesium, manganese, and copper; and trivalent metal salts such as iron and aluminum. Examples include salt. Specific metal salts include sodium chloride, potassium chloride, lithium chloride, calcium chloride, magnesium chloride, zinc chloride, copper sulfate, magnesium sulfate, manganese sulfate, polyaluminum chloride, etc. It is particularly preferable to use a divalent or trivalent metal salt since aggregation can proceed with a smaller amount. These can be used alone or in combination of two or more.

[5] Developer When the toner of the present invention contains a magnetic material and is used as a one-component magnetic toner, for example, when mixed with a so-called carrier and used as a two-component developer, a non-magnetic toner may be used alone. Various cases can be considered, and any of them can be suitably used.

As the magnetic material, for example, magnetite, γ-hematite, various ferrites, etc. can be used.

As the carrier constituting the two-component developer, magnetic particles made of conventionally known materials such as metals such as iron, steel, nickel, cobalt, ferrite, and magnetite, and alloys of these metals with metals such as aluminum and lead are used. Can be used.

As the carrier, it is preferable to use a coated carrier in which the surface of magnetic particles is coated with a coating agent such as a resin, or a so-called resin-dispersed carrier in which magnetic powder is dispersed in a binder resin. The coating resin is not particularly limited, but for example, olefin resin, styrene resin, styrene/acrylic resin, silicone resin, polyester resin, or fluororesin can be used. In addition, the resin for forming the resin-dispersed carrier is not particularly limited, and any known resin can be used, such as acrylic resin, styrene/acrylic resin, polyester resin, fluororesin, phenol resin, etc. can do.

The volume-based median diameter of the carrier is preferably 20 to 100 μm, more preferably 25 to 60 μm. The volume-based median diameter of the carrier can typically be measured using a laser diffraction particle size distribution analyzer "HELOS" (manufactured by SYMPATEC) equipped with a wet dispersion machine.

The amount of toner to be mixed with the carrier is preferably 2 to 10% by mass, based on the total mass of toner and carrier as 100% by mass.

[6] Image Forming Method The toner of the present invention can be suitably used in an image forming method including a fixing step using a heat-pressure fixing method that can apply pressure and heat. Particularly suitable for image forming methods in which the fixing temperature in the fixing step is relatively low, such that the surface temperature of the heating member in the fixing nip is 80 to 110°C, preferably 80 to 95°C. It can be used for.

Furthermore, it can be suitably used in a high-speed fixing image forming method in which the fixing linear velocity is 200 to 600 mm/sec.

Specifically, in this image forming method, the toner of the present invention as described above is used to develop an electrostatic charge image formed on a photoconductor to obtain a toner image. Transfer to image support. Thereafter, the toner image transferred onto the image support is fixed to the image support by a heat-pressure fixing process, thereby obtaining a printed matter on which a visible image is formed.

Further, the toner of the present invention can be used in a monochrome image forming method or a full color image forming method. Full-color image forming methods include a four-cycle image forming method consisting of four types of color developing devices for each of yellow, magenta, cyan, and black and one photoreceptor, and a color developing method for each color. The invention can be applied to any image forming method, such as a tandem image forming method in which image forming units each having a device and a photoreceptor are mounted for each color.

EXAMPLES Hereinafter, the present invention will be specifically explained with reference to Examples, but the present invention is not limited thereto. In the examples, "parts" or "%" are used, but unless otherwise specified, "parts by mass" or "% by mass" are expressed.

<Measurement of peak molecular weight of polymer>
The peak molecular weight of the polymer contained in the binder resin was measured as follows.

Using an apparatus "HLC-8220" (manufactured by Tosoh Corporation) and a column "TSKguard column + TSK gel Super HZM-M triple series" (manufactured by Tosoh Corporation), tetrahydrofuran (THF) was used as a carrier solvent at a flow rate of 0.05°C while maintaining the column temperature at 40°C. The measurement sample was dissolved in tetrahydrofuran at a flow rate of 2 ml/min to a concentration of 1 mg/ml under dissolution conditions of 5 minutes treatment using an ultrasonic disperser at room temperature (25° C.). Next, a sample solution was obtained by processing with a membrane filter with a pore size of 0.2 μm, and 10 μl of this sample solution was injected into the device together with the above carrier solvent, and detected using a refractive index detector (RI detector), and measured. It was determined from the molecular weight distribution of the sample.

[Example 1]
(Preparation of toner 1)
(Preparation of binder resin particle dispersion 1)
A surfactant solution prepared by dissolving 8 g of sodium dodecyl sulfate in 3 L of ion-exchanged water was charged into a 5 L stainless steel pot (SUS pot) equipped with a stirring device, temperature sensor, cooling tube, and nitrogen introducing device, and the mixture was heated at 230 rpm under a nitrogen stream. The liquid temperature was raised to 80°C while stirring at a stirring speed of .

To this surfactant solution, an initiator solution in which 10 g of potassium persulfate was dissolved in 200 g of ion-exchanged water was added, and the temperature was brought to 80°C. Then, the following monomer mixture was added dropwise over 100 minutes. Polymerization was performed by heating and stirring the system at 80° C. for 2 hours to prepare binder resin particle dispersion 1:
- Monomer mixture -
Exemplary compound M1 (see chemical formula above) 644 parts by mass n-butyl acrylate (BA) 76.5 parts by mass 2-ethylhexyl acrylate (2EHA) 32.2 parts by mass Methacrylic acid (MAA) 52.3 parts by mass n-octyl -3-Mercaptopropionate 5.5 parts by mass The volume-based median diameter of the binder resin particles in the obtained binder resin particle dispersion 1 was measured using "Microtrack UPA-150" (manufactured by Nikkiso Co., Ltd.). When measured using a dynamic light scattering method, the wavelength was 115 nm.

(Preparation of colorant dispersion 1)
Colorant: Carbon black (Mogul (registered trademark) L manufactured by Cabot)
10 parts by mass anionic surfactant (20% aqueous solution of sodium dodecylbenzenesulfonate)
1.5 parts by mass Ion-exchanged water 90 parts by mass The above components were mixed and dispersed in an SC mill to obtain Colorant Dispersion 1. The volume-based median diameter of the colorant particles in the dispersion was measured by dynamic light scattering using "Microtrac UPA-150" (manufactured by Nikkiso Co., Ltd.) and was found to be 152 nm.

(Preparation of release agent dispersion 1)
Behenyl behenate 100 parts by mass Sodium dodecyl sulfate 5 parts by mass Ion-exchanged water 240 parts by mass The above ingredients were mixed in a round stainless steel flask using a homogenizer "Ultra Turrax (registered trademark) T50" (manufactured by IKA Corporation). After dispersing for 10 minutes, dispersion treatment was performed using a pressure discharge type homogenizer to obtain mold release agent dispersion 1. The volume-based median diameter of the release agent particles in the dispersion was measured using a laser diffraction particle size distribution analyzer LA-750 (manufactured by Horiba, Ltd.) and was found to be 540 nm.

(Preparation of toner base particle dispersion liquid 1)
Binder particle dispersion 1 237 parts by mass Colorant dispersion 1 42 parts by mass Release agent dispersion 1 18 parts by mass Polyaluminum chloride 1.8 parts by mass Ion exchange water 600 parts by mass The above ingredients were mixed into a round stainless steel flask. After mixing and dispersing the mixture using a homogenizer "Ultra Turrax (registered trademark) T50" (manufactured by IKA) in a heating oil bath, the flask was heated to 55° C. while stirring inside the flask. After holding the solution at 55° C. for 30 minutes, it was confirmed that aggregated particles having a volume-based median diameter (D50) of 4.8 μm were formed in the solution.

When the temperature of the heating oil bath was further raised and held at 56° C. for 2 hours, the volume-based median diameter (D50) became 5.9 μm.

After that, 1 mol/L of sodium hydroxide was added to the system to adjust the pH of the system to 5.0, and then the stainless steel flask was sealed using a magnetic seal and heated to 98°C while continuing to stir. did. By continuing stirring for 6 hours, fusion (fusion) between the binder resin particles was completed, and toner base particle dispersion 1 was prepared. The volume-based median diameter (D50) of the toner base particles in the dispersion was 6.0 μm.

(Washing/drying process)
Toner base particle dispersion 1 was subjected to solid-liquid separation using a basket-type centrifugal separator "MARK III model number 60x40" (manufactured by Matsumoto Kikai Sales Co., Ltd.) to form a wet cake of toner base particles.

The wet cake was washed with ion-exchanged water at 45°C in the above-mentioned basket centrifuge until the electrical conductivity of the filtrate reached 5 μS/cm, and then transferred to a "flash jet dryer" (manufactured by Seishin Enterprise Co., Ltd.). , and dried until the moisture content became 0.5% by mass to obtain toner base particles.

(External additive treatment of toner base particles)
For 100 parts by mass of the toner base particles obtained above, 1 part by mass of hydrophobic silica (number average primary particle diameter = 12 nm) and 0.3 mass part of hydrophobic titania (number average primary particle diameter = 20 nm). Toner 1 was manufactured by adding 100% of the total amount of the toner and mixing with a Henschel mixer (registered trademark) to perform external additive treatment.

[Examples 2 to 20, Comparative Examples 21 to 23]
(Production of toner 2 to toner 23)
A binder resin particle dispersion was prepared using the monomer combinations and amounts added in Table 2 below, a release agent dispersion was prepared using the release agents listed in Table 2 below, and Table I below. Toners 2 to 23 were produced in the same manner as in Example 1, except that toner base particles were prepared using a binder resin particle dispersion and a release agent dispersion so as to have the contents described in . did.

The volume-based median diameter of the binder resin particles in each binder resin particle dispersion prepared using the monomer combinations and addition amounts shown in Tables I and II below was 120 nm.

Furthermore, the volume-based median diameters of the release agent particles in each release agent dispersion prepared using the release agents listed in Tables I and II below were as follows:
・Pentaerythritol tetrabehenate: 480nm
・Stearyl stearate: 450nm
・Methyl lignocerate: 420nm
・Hexadecyl palmitate: 430nm
・Methyl triacontanoate: 440nm
・Paraffin (paraffin wax, HNP-51, manufactured by Nippon Seiro Co., Ltd.): 600 nm
- Oleic acid monoamide (fatty acid amide wax, Alflow (registered trademark) E10, manufactured by NOF Corporation): 400 nm.

The composition of each toner is shown in Tables I and II below. In Tables I and II below, "H" represents a hydrogen atom, "OH" represents a hydroxy group, "Me" represents a methyl group, "OMe" represents a methoxy group, "OEt" represents an ethoxy group, "O-nBu" represents an n-butyloxy group, "n-Bu" represents an n-butyl group, and "t-Bu" represents a tert-butyl group.
Further, "BA" represents n-butyl acrylate, "2EHA" represents 2-ethylhexyl, "MMA" represents methyl methacrylate, and "MAA" represents methacrylic acid.

Furthermore, "amount of polymer added (mass %)" in Tables I and II is the content ratio of each monomer to the total mass of the first monomer and the second monomer. "Content of mold release agent (mass %)" in Tables I and II is the content ratio of the mold release agent to the total mass of the polymer and the mold release agent, which is 100 mass % in total.
Furthermore, the notation "(number of carbon atoms in parentheses)" for the release agent in Tables I and II refers to the number of carbon atoms in the fatty acid moiety of the release agent.

≪Evaluation≫
(Preparation of two-component developer)
100 parts by mass of ferrite particles (median diameter based on volume: 50 μm (manufactured by Powder Tech Co., Ltd.)) and 4 parts by mass of methyl methacrylate-cyclohexyl methacrylate copolymer resin (median diameter based on volume of primary particles: 85 nm), The mixture was placed in a horizontal stirring blade type high speed stirring device and mixed for 15 minutes at a stirring blade circumferential speed of 8 m/s and a temperature of 30°C, and then the temperature was raised to 120°C and stirring was continued for 4 hours. Thereafter, a resin-coated carrier was prepared by cooling and removing fragments of the methyl methacrylate-cyclohexyl methacrylate copolymer resin using a 200 mesh sieve.

This resin-coated carrier was mixed with each of the above-mentioned toners 1 to 23 so that the toner concentration was 7% by mass based on the total mass of toner and carrier to prepare two-component developers 1 to 23.

The following evaluation items (1) to (2) were evaluated using the produced two-component developers 1 to 23.

(1) Hot offset resistance A commercially available multifunction device "bizhub PRO C6500" (manufactured by Konica Minolta Business Technologies, Inc.) was used as an image forming device, the above two-component developer was installed as a developer in this device, and a hot roll was used. The surface temperature of the fixing heating member in the fixing means of the fixing method was changed in the range of 80 to 150 degrees Celsius in 10 degrees Celsius increments, and for each temperature, in an environment of normal temperature and normal humidity (temperature 20 degrees Celsius, humidity 50% RH), Image formation was performed using cardboard with a basis weight of 64 g/m ² as an image support, and a solid image with an image density of 0.8 was obtained as a visible image. The degree of hot offset occurrence at that time was evaluated in five stages.

Rank 5: No hot offset occurs Rank 4: Hot offset occurs at 150℃ Rank 3: Hot offset occurs at 140℃ Rank 2: Hot offset occurs at 130℃ Rank 1: Hot offset occurs below 130℃

(2) Film adhesion (fixing strength)
A commercially available multifunction device "bizhub PRO C6500" (manufactured by Konica Minolta Business Technologies, Inc.) was used as an image forming device, and the above two-component developer was installed in this device as a developer, and the image was fixed in a fixing means using a heat roll fixing method. The surface temperature of the heating member was changed in the range of 80 to 150°C in 10°C increments, and for each temperature, the thickness Image formation was performed using a 25 μm polypropylene film, and a solid image with an image density of 0.8 was obtained as a visible image. Thereafter, it was folded using a folding machine, air of 0.35 MPa was blown onto it, and the condition of the fold was evaluated on a five-point scale with reference to a limit sample.

Rank 5: No peeling at all along the crease Rank 4: Partial peeling along the crease Rank 3: Thin linear peeling along the crease Rank 2: Thick peeling along the crease Rank 1: Large peeling on the image Above (1) ~ The evaluation results of (2) are shown in Table III below.

As is clear from the above Table III, toners 1 to 20 of the present invention containing a polymer having a structural unit represented by the above general formula (1) and using a fatty acid ester wax as a release agent have high durability. It was found that the film exhibited excellent performance in terms of offset properties and film adhesion (fixing strength). On the other hand, toner 21 containing a polymer having a styrene structural unit and toners 22 and 23 using paraffin wax or fatty acid amide wax as a release agent other than fatty acid ester have hot offset resistance and good film adhesion. It turned out that it is difficult to achieve both.

Claims (12)

A toner for developing an electrostatic image containing toner particles,
The toner particles contain a polymer having a structural unit represented by the following general formula (1) as a binder resin, and a fatty acid ester wax as a release agent,
A toner for developing an electrostatic image , wherein the fatty acid ester wax contains a fatty acid ester wax using a fatty acid having 18 to 24 carbon atoms .

(In the formula, R ₁ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. _{R 2} and R ₃ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group. R ₄ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a carboxy group, or an ester group having 2 to 5 carbon atoms.) The toner for developing an electrostatic image according to claim 1, wherein the R ₁ is a hydrogen atom or a methyl group. The toner for developing an electrostatic image according to claim 1 or 2, wherein the R ₂ and R ₃ are methoxy groups. The toner for developing an electrostatic image according to claim 1 or 2, wherein one of R ₂ and R ₃ is a methoxy group and the other is a hydrogen atom. The toner for developing an electrostatic image according to claim 1 or 2, wherein the R ₂ and R ₃ are hydrogen atoms. The toner for developing an electrostatic image according to any one of claims 1 to 5, wherein the R ₄ is a hydrogen atom, a carboxy group, or an ester group having 2 to 5 carbon atoms. A polymer having a structural unit represented by the general formula (1) has a first polymerizable monomer represented by the following general formula (2) and a second polymerizable monomer other than the first polymerizable monomer. 7. The toner for developing an electrostatic image according to claim 1, wherein the toner is a copolymer with a polymerizable monomer.

(In the formula, R ₁ to R ₄ have the same meanings as R ₁ to R ₄ in the above general formula (1).) 8. The second polymerizable monomer is at least one selected from acrylic acid, n-butyl acrylate, 2-ethylhexyl acrylate, methacrylic acid, and methyl methacrylate. The electrostatic image developing toner described above. 9. The toner for developing an electrostatic image according to claim 1, wherein the fatty acid ester wax contains behenyl behenate or pentaerythritol tetrabehenate. The electrostatic image forming apparatus according to any one of claims 1 to 9 , wherein the content of the fatty acid ester wax in the electrostatic image developing toner is within a range of 5 to 25% by mass. Toner for developing charge images. A toner for developing an electrostatic image containing toner particles,
For electrostatic image development, wherein the toner particles contain a polymer having a structural unit represented by the following general formula (1) as a binder resin, and a fatty acid ester wax as a release agent. toner.

(In the formula R ₁ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. R ₂ and R ₃ is a methoxy group, or R ₂ and R ₃ One of them is a methoxy group and the other is a hydrogen atom. R ₄ represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a carboxy group, or an ester group having 2 to 5 carbon atoms. ) A method for producing an electrostatic image developing toner containing toner particles comprising at least a binder resin and a release agent, the method comprising:
Synthesizing a polymer having a structural unit represented by the following general formula (1) as the binder resin by radical polymerization using a polymerizable monomer represented by the following general formula (2);
The mold release agent is a fatty acid ester wax using a fatty acid having 18 to 24 carbon atoms,
The fatty acid ester wax contains behenyl behenate or pentaerythritol tetrabehenate,
mixing the binder resin and the mold release agent;
A method for producing a toner for developing an electrostatic image, comprising:

(In the formula, R ₁ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms. _{R 2} and R ₃ each independently represent a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or an alkoxy group. R ₄ is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, an alkoxy group having 1 to 4 carbon atoms, a carboxy group,
Or represents an ester group having 2 to 5 carbon atoms. )

(In the formula, R ₁ to R ₄ have the same meanings as R ₁ to R ₄ in the above general formula (1).)