JP2001281932A - Electrostatic charge image developing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner which has a good spectral reflection characteristic and has excellent hot offset resistance and OHP transmitabbility and therefore allows multicolor superposition, is good in color reproducibility and provides a full color image of bright color tones. SOLUTION: The electrostatic charge image developing toner consisting of at least a binder resin, coloring agents and wax contains pigment red 238, pigment red 147 and compound having a structure analogous therewith and exhibits the maximum endothermic peak at a region of 50 to 130 deg.C during heating up at a DSC curve measured by a differential scanning calorimeter.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magenta toner for developing an electrostatic image used in a dry toner of an electrophotographic copying machine or the like.

[0002]

2. Description of the Related Art Copiers and printers using electrophotography, especially full-color copiers and printers that reproduce full-color images by superimposing images using color toners such as cyan, magenta, and yellow, have rapidly spread. I have. With toner that reproduces full-color images, the spectral reflection characteristics of each color toner should be close to the ideal curve in order to faithfully reproduce the colors of the original image.
Further, it is important that the toners of the respective colors are sufficiently mixed in the heating and pressing fixing step. Furthermore, it is important that images on an overhead projector (hereinafter referred to as OHP) sheet have good transparency and spectral transmittance.

In order to satisfy these requirements, a binder resin used for a full-color toner is preferably a low-molecular-weight resin having a sharp melt property. However, when the sharp-melting binder resin is used, when the toner is melted in the fixing process,
Since the self-cohesive force of the binder resin is low, there is a problem that hot offset easily occurs. As an additive for improving hot offset resistance, high melting point polyethylene wax or high melting point polypropylene wax has conventionally been used in black toner. However, although the addition to these full-color toners improves hot offset resistance, the transparency of the image on the OHP sheet becomes low due to the crystallinity of these waxes, and as a result, the projected image becomes saturated or light. Is undesirably low.

In order to solve this problem, the amount of wax added to the toner is suppressed, and instead, an oil such as silicone oil or fluorine oil is applied to the heat fixing roller to prevent hot offset at the time of fixing and OHP permeability. There is a way to balance. However, the fixed image obtained in this way is unfavorable to the user because extra oil adheres to the surface. Further, since a device for uniformly applying oil to the fixing roller is required, the size of the copying machine and the printer tends to increase. Therefore, there is a need for a toner that does not generate hot offset even without an oil application step for preventing hot offset and that can provide an image with good OHP transparency.

[0005] Of the full-color toners, a coloring agent used for the magenta toner has conventionally been C.I. I. Pigment Red 48, 48: 1, 49: 1, 53: 1
Magenta pigments such as 57, 57: 1, 81, 122, 146, 149, 177, 184, and Pigment Violet 19; and magenta colored colors such as magenta dyes such as xanthene dyes Various known dyes and pigments are used. It is known that the magenta colorant contained in the general formula (I) is also used in the toner, and JP-A-11-272014 discloses C.I. I. Pigment Red 238 and 147 are disclosed.

[0006]

Embedded image (In Formula I, A, B, and C are aromatic rings that may have a substituent.)

A magenta colorant having a structure other than the general formula (I), ie, C.I. I. Pigment Red 48, 4
8: 1, 49: 1, 53: 1, 57, 57:
1, 81, 122, 146, 149, 17
7, 184, Pigment Violet 19, and the like have problems such as the spectral reflection characteristics and spectral transmission characteristics deviating from the ideal magenta color tone, and insufficient OHP transmission. In addition, there are some which are not commercially useful because the synthesis is complicated or the raw materials for the synthesis are expensive. A coloring agent having a structure represented by the general formula (I) is commercially available because it is obtained by reacting a diazonium salt with a coupler that performs a coupling reaction, and is easy to produce. Further, it is preferable that the spectral reflection characteristics and the spectral transmission characteristics are close to ideal magenta color tones.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art.
That is, an object of the present invention is to provide a magenta toner having good color reproducibility and OHP transparency and having excellent hot offset resistance.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies in view of the above problems, and have found that at least a binder resin, a colorant,
It has been found that the above problem can be solved by using a magenta colorant having a specific structure and a wax exhibiting a specific maximum endothermic peak when obtaining a toner for developing an electrostatic charge image composed of wax, and arrived at the present invention. That is, the gist of the present invention is to provide a toner for developing an electrostatic image comprising at least a binder resin, a colorant, and a wax, which contains a compound represented by the following general formula (I) as a colorant, and the wax has a differential scanning calorimetry. The toner for developing an electrostatic image is characterized in that a DSC curve measured by a meter shows a maximum endothermic peak in a range of 50 to 130 ° C. when the temperature is raised.

[0010]

Embedded image (In Formula I, A, B, and C are aromatic rings that may have a substituent.)

BEST MODE FOR CARRYING OUT THE INVENTION

The toner of the present invention comprises at least a binder resin,
It is composed of a colorant and a wax, and may contain a charge control agent and other additives as necessary. The toner of the present invention
In a DSC curve measured by a differential scanning calorimeter,
50 to 130 ° C., preferably 60 to 120 ° C. when the temperature is raised,
More preferably, it shows the maximum endothermic peak in the range of 65 to 100 ° C. The source of the maximum endothermic peak in the above temperature range is usually a wax. By having the maximum endothermic peak in the above temperature range, part or all of the wax melts during fixing. As a result, the surface of the fixed image is easily smoothed, and the OHP transparency is improved. In addition, since the viscosity of the binder resin is reduced, the color mixing of each color toner is improved. Further, since part or all of the melted wax is released on the surface of the toner image, it acts as an oil to be applied to the heat fixing roller, thereby satisfying the hot offset resistance.

A wax having a maximum endothermic peak of less than 50 ° C. is not preferred because the self-cohesive force of the wax is weak, resulting in a decrease in hot offset resistance. Further, the wax having a maximum endothermic peak exceeding 130 ° C. increases the fixing temperature of the toner and makes it difficult to appropriately smooth the surface of the fixed image. In addition, the color mixing property of each color toner at the time of fixing decreases, which is not preferable. Further, those having a sharp maximum endothermic peak are preferred. Specifically, the half width is 2
Those having a temperature of 0 ° C. or lower are preferable, and those having a temperature of 15 ° C. or lower are more preferable.

Specifically, vegetable waxes such as carnauba wax and rice wax, solid silicone waxes such as alkyl-modified silicone, amide waxes such as stearamide, higher fatty alcohol waxes, higher fatty acid ester waxes, Examples include synthetic hydrocarbon waxes such as low melting point polyethylene and low melting point polypropylene, and mixtures thereof. Preferably, an ester wax having a long-chain aliphatic group, more preferably, behenyl behenate or stearyl stearate is used. Among them, compounds having 16 to 64 carbon atoms are preferable, esters of fatty acids having 16 to 64 carbon atoms are more preferable, and fatty acid esters having 24 to 52 carbon atoms are particularly preferable. The added amount of the wax is preferably in the range of 0.5 to 30 parts by weight. When the toner is manufactured by the polymerization method,
Since a large amount of 30 parts by weight can be added, a large amount may be added if necessary.

Since the toner for developing an electrostatic image of the present invention contains a compound represented by the general formula (I) as a colorant, its color tone is a magenta color having a good spectral reflection characteristic. Also,
When the colorant is dispersed in the binder resin, its OHP permeability tends to be higher than when other magenta colorants are used. By using the wax at the same time as using the compound represented by the general formula (I), high OHP permeability can be realized.

The toner for developing an electrostatic image of the present invention contains a compound represented by the general formula (I) as a colorant. Can also be used in combination. General formula (I)
The mixing ratio of the compound represented by
0: 0 to 5:95 can be selected, but color reproducibility and O
For HP permeability, the ratio of the compound represented by the general formula (I) is preferably 30% or more, and more preferably 50% or more.

[0016]

Embedded image (In Formula I, A, B, and C are aromatic rings that may have a substituent.)

The amount of the colorant added is 2 to the binder resin.
A range of 25 parts by weight is preferred. In the general formula (I),
A, B, and C each represent an aromatic ring such as a benzene ring, a naphthalene ring, an anthracene ring, or a phenanthrene ring. Of these, a benzene ring or a naphthalene ring is preferable, and A is a benzene ring; Preferably, the ring, C, is a benzene ring. Further, in the general formula (I), an aromatic ring (A, B,
Examples of the substituent in C) include a halogen atom, a nitro group, a cyano group, a hydrocarbon group, an alkoxy group, an alkylthio group, an amino group, an amino group which may be substituted on a nitrogen atom, and a substitution on a nitrogen atom. Aminocarbonyl group, an aminosulfonyl group which may be substituted on the nitrogen atom, an alkylsulfonyl group, an alkoxysulfonyl group, and the like, and usually include stable substituents. Those having 12 to 300 are preferred.

Of these substituents, a halogen atom, a nitro group, a cyano group, a hydrocarbon group having 5 or less carbon atoms,
The following alkoxy group, aminosulfonyl group optionally substituted on a nitrogen atom, or aminocarbonyl group optionally substituted on a nitrogen atom are more preferred. More specifically, a compound represented by the following general formula (II) can be preferably used. These compounds are advantageous in production.

[0019]

Embedded image

(In the formula II, R ¹ , R ⁴ , R ⁵ and R ⁶ each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydrocarbon group having 5 or less carbon atoms, R ² and R ³ each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydrocarbon group having 5 or less carbon atoms, an alkoxy group having 5 or less carbon atoms, a nitrogen atom Represents an optionally substituted aminosulfonyl group or an aminocarbonyl group optionally substituted on a nitrogen atom, provided that an aminosulfonyl group optionally substituted on a nitrogen atom or substituted on a nitrogen atom At least one aminocarbonyl group which may be
Have one. )

Here, as the substituent on the nitrogen in the aminosulfonyl group optionally substituted on the nitrogen atom or the aminocarbonyl group optionally substituted on the nitrogen atom, a phenyl group, a tolyl group, etc. An alkyl group such as an aryl group, a methyl group, an ethyl group, a 1-propyl group, or a 1-butyl group; an aralkyl group such as a benzyl group; an aryl group substituted with a halogen atom or an alkoxy group; a halogen atom or an alkoxy group; And an alkyl group. Further, in the general formula (II), R ¹ is a methoxy group, R ² is a hydrogen atom, R ³ is a phenylaminocarbonyl group, R ⁴ is a methoxy group, R ⁵ is a hydrogen atom, Using a compound in which R ⁶ is a chlorine atom, that is, a compound represented by the following formula (III):
It is preferable in terms of spectral reflection characteristics and spectral transmission characteristics.

[0022]

Embedded image

The binder resin used in the present invention can be selected from a wide range including those conventionally known. Preferably, a styrene-based polymer such as a styrene-acrylate copolymer, a styrene-methacrylate copolymer, or an acrylic acid copolymer of these resins, a saturated or unsaturated polyester-based polymer, and an epoxy-based polymer are exemplified. be able to. Further, the binder resin is not limited to being used alone, and may be used in combination of two or more kinds.

A charge controlling agent may be added to the electrostatic image developing toner of the present invention in order to impart a charge amount and charge stability. Known compounds are used as the charge control agent.
Examples thereof include metal complexes of hydroxycarboxylic acids, metal complexes of azo compounds, naphthol compounds, metal compounds of naphthol compounds, nigrosine dyes, quaternary ammonium salts, and mixtures thereof. Preferably, a compound represented by the following general formula (IV) or a metal salt thereof is used.

[0025]

Embedded image

(In the formula IV, D, E, F, and G each represent an aromatic ring which may have a substituent. X represents a divalent bonding group or a direct bond.) , E, F, and G include aromatic rings such as benzene ring, naphthalene ring, phenanthrene ring, and anthracene ring. Preferably, D and E are naphthalene rings, and F and G are benzene rings. . When these aromatic rings have a substituent, the substituent is preferably a halogen atom, a nitro group, a cyano group, an alkyl group having 1 to 5 carbon atoms, or an alkoxy group having 1 to 5 carbon atoms.
A halogen atom is more preferred as the substituent for F and G.

X is a divalent linking group, specifically, a methylene group, an ethylene group, a 1,3-propylene group,
Isopropylidene group, a hydrocarbon group such as an ethylidene group, a sulfur atom, an oxygen atom, a sulfonyl group, a sulfo group, a carbonyl group, and the like, and a divalent hydrocarbon group is preferable.
Methylene groups are more preferred. The addition amount of the charge control agent is preferably in the range of 0.1 to 8 parts by weight based on the binder resin.

The method for producing the toner for developing an electrostatic image of the present invention may be any of a pulverization method and a polymerization method. In the pulverization method, first, the binder resin, the compound represented by the formula (I), the wax, the charge control agent, and the like are uniformly dispersed by a ball mill, a V-type mixer, an S-type mixer, a Henschel mixer, or the like. Formula (I)
Any of the compounds represented by the formula, the wax, the charge control agent, and the like may be added to the binder resin in advance. Next, the dispersion is melt-kneaded with a kneader or the like. Next, after cooling, the mixture is pulverized by a pulverizer such as a hammer mill, a jet mill, and a ball mill, and the obtained powder is classified by an air classifier or the like to obtain a toner.

The toner for developing an electrostatic charge image of the present invention has good spectral reflection characteristics, OHP transmission properties and hot offset resistance by using the above-mentioned coloring agent and the wax, but further has good OHP transmission properties. To achieve this, it is necessary to uniformly disperse the above-mentioned colorant in the toner with a smaller particle size. For this purpose, the polymerization method is preferred in the present invention. The reason is as follows. In the suspension polymerization method, a colorant, a charge controlling agent, a wax, and the like are mixed with a polymerizable monomer, and then the polymerizable monomer is subjected to suspension polymerization to produce a toner. Therefore, in order to uniformly disperse the colorant having a small particle diameter in the toner, it is necessary that the colorant has high dispersibility in the polymerizable monomer.

When producing a toner by the emulsion polymerization aggregation method,
Since the colorant, charge control agent, wax, etc. are mixed in the form of a dispersion, the first condition in these selections is that processing into a dispersion with little change over time is the first condition. In order to obtain high OHP permeability, it is necessary to be able to process a colorant dispersion having a small particle size and a narrow particle size distribution, which gives a toner in which a colorant having a small particle size is uniformly dispersed.

The compound represented by the formula (I) can be easily dispersed to a small particle size in the step of dispersing the polymerizable monomer in the suspension polymerization method. Also in the emulsion polymerization aggregation method, a dispersion having a small particle size and a narrow particle size distribution can be easily prepared. Therefore, when the polymerization method is used, the compound represented by the formula (I) can be uniformly dispersed with a small particle diameter in the toner.
Further, in order to obtain a high-definition image, it is advantageous that the particle size distribution of the toner is uniform. For this purpose, an emulsion polymerization aggregation method which can easily obtain a toner having a narrow particle size distribution is preferable.

When the toner for developing an electrostatic image of the present invention is obtained by the emulsion polymerization aggregation method, the binder resin is used in the form of an emulsion. Examples of the method of preparing the binder resin emulsion include a method of preparing the emulsion by emulsion polymerization, and a method of dissolving the binder resin in a water-soluble or water-insoluble organic solvent, and then adding the resulting solution to water to emulsify. Further, a binder resin emulsion containing wax can also be used.

When the toner for developing an electrostatic image of the present invention is obtained by the emulsion polymerization aggregation method, the compound represented by the formula (I), the wax and the charge control agent are used in the form of a dispersion. This dispersion can be easily prepared by adding each of the compounds together with a surfactant to water and using a mechanical pulverization method containing a medium or the like. Surfactants include nonionic surfactants represented by polyoxyethylene alkyl phenyl ethers, anionic surfactants represented by alkylbenzene sulfonates, and cationic surfactants represented by quaternary ammonium salts. However, it is preferable to use polyoxyethylene styryl ether or dodecylbenzene sulfonate. Further, a water-soluble organic solvent may be added as needed. The dispersion diameter is in the range of 0.001 to 1.5 μm, preferably 0.01 to 1 μm.

In the emulsion polymerization aggregation method, a colorant dispersion, a charge control agent dispersion, a wax dispersion, and the like are mixed with a polymer emulsion, and the mixture is aggregated by appropriately controlling the temperature, salt concentration, pH, and the like to form a toner. To manufacture. The toner particle size is usually in the range of 2 to 10 μm, preferably 3 to 8 μm, and more preferably 4 to 7 μm. The obtained toner is usually
Since the surface active agent and the like remain on the surface, acid washing, alkali washing, water washing and the like are appropriately performed in order to remove the surfactant, and the toner for developing an electrostatic image of the present invention is obtained by filtering and drying.

In the suspension polymerization method, a colorant,
A charge controlling agent, wax and the like are mixed and subjected to a dispersion treatment using a disperser such as a disperser, and the monomer composition after the dispersion treatment is dispersed in a water-miscible medium using an appropriate stirrer. After granulating to a diameter, the polymerizable monomer is polymerized to produce a toner. The compound represented by the formula (I) can be easily and uniformly dispersed in the polymerizable monomer by a dispersion treatment. The toner particle size is usually in the range of 2 to 10 μm, preferably 3 to 8 μm, and more preferably 4 to 7 μm.

When a suspension stabilizer is used, it is preferred to select a neutral or alkaline one which can be easily removed by washing the toner after the polymerization with acid. Further, it is preferable to select a toner capable of obtaining a toner having a narrow particle size distribution. Suspension stabilizers that satisfy these requirements include calcium phosphate, tricalcium phosphate, magnesium phosphate, calcium hydroxide, magnesium hydroxide and the like. Each can be used alone or in combination of two or more. These suspension stabilizers can be used in an amount of 1 to 10 parts by weight based on the radical polymerizable monomer. As the polymerization initiator, known polymerization initiators can be used alone or in combination of two or more. For example,
Use potassium persulfate, 2,2'-azobisisobutyronitrile, 2,2'-azobisiso (2,4-dimethyl) valeronitrile, benzoyl peroxide, lauroyl peroxide, or redox initiator Can be.

After producing the toner by the above method, a toner having a capsule structure is produced by adding a polymer emulsion, a colorant dispersion, a charge control agent dispersion, a wax dispersion and the like to coat the toner surface. be able to. A known external additive may be added to the toner for developing an electrostatic image of the present invention in order to control fluidity and developability. As the external additive, various kinds of inorganic oxide particles such as silica, alumina, titania and the like (which may be subjected to a hydrophobic treatment if necessary), vinyl polymer particles and the like can be used. The amount of the external additive is preferably in the range of 0.05 to 5 parts by weight based on the toner particles. The electrostatic image developing toner of the present invention can be developed by a known developing method. For example, cascade method, magnetic brush method, two-component developing method such as microtoning method, conductivity,
It can be used for any of the insulating one-component developing method and the non-magnetic one-component developing method.

The reason why the toner of the present invention exhibits excellent effects is not necessarily clear, but first, the compound represented by the formula (I) can be easily dispersed by the above method. Having a hydroxyl group in the ring, this can be dispersed with a small particle size and narrow particle size distribution even with a small amount of dispersant,
It is also presumed that this contributes to obtaining a dispersion liquid with little change over time. Further, the compound represented by the formula (I) is used as a coloring agent, and the DSC curve measured by a differential scanning calorimeter shows that the toner shows a maximum endothermic peak in a region of 50 to 130 ° C. when the temperature is raised. By containing a specific wax to achieve the above, the hot offset resistance and the OHP transmission can be further realized without impairing the original spectral reflection characteristics of the colorant.

[0039]

EXAMPLES The present invention will be described in more detail with reference to the following Examples, but it should not be construed that the present invention is limited to the following Examples without departing from the scope of the invention. In the following examples, the maximum endothermic peak was determined by DSC (Seiko Electronic Industry Co., Ltd.)
DSC-20).

(Preparation of Colorant Dispersion) a) Colorant Dispersion A 160 g of demineralized water and 5 g of an alkylbenzene sulfonate as a dispersant were added to 40 g of the compound of the above formula (III) and dispersed for 5 hours by a sand grinder mill. As a result, a colorant dispersion A having an average particle size of 0.18 μm was obtained. B) Colorant Dispersion B (Comparative Colorant Dispersion) Pigment Red 48: 250 g in 150 g of demineralized water,
7.6 g of an alkylbenzene sulfonate was added as a dispersant, and the mixture was subjected to a dispersion treatment with a sand grinder mill for 5 hours to obtain a comparative colorant dispersion B having an average particle size of 0.20 μm.

(Synthesis of Binder Resin Emulsion) a) Binder Resin Emulsion A 2.2 kg of an ester wax emulsion having a solid content of 30% (maximum endothermic peak 70.3 ° C.), 26
and heated to 90 ° C., and 6 g of dodecylbenzenesulfonate, 5 kg of styrene, 1.3 kg of n-butyl acrylate, 186 g of acrylic acid, and 2 parts of divinylbenzene 2
5 g, trichlorobromomethane 31 g, 8% hydrogen peroxide aqueous solution 656 g, and 8% ascorbic acid aqueous solution 656 g were added. The reaction was continued at 90 ° C. for 7 hours to obtain a binder resin emulsion A composed of a styrene acrylic polymer.

B) Binder resin emulsion B In a reactor, 38 kg of demineralized water was added, and the temperature was raised to 90 ° C., and 28 g of dodecylbenzenesulfonate, 7.5 kg of styrene,
2 kg of n-butyl acrylate, 280 g of acrylic acid,
40 g of divinylbenzene, 48 of trichlorobromomethane
g of an 8% aqueous hydrogen peroxide solution and 1,000 g of an 8% aqueous ascorbic acid solution were added. The reaction was continued at 90 ° C. for 7 hours to obtain a binder resin emulsion B composed of a styrene acrylic polymer.

(Preparation of Charge Control Agent Dispersion) 40 g of 4,4'-methylenebis [2- [N- (4-chlorophenyl) amide] -3-hydroxynaphthalene] was added to deionized water 16 g.
0 g and 8 g of an alkylnaphthalene sulfonate as a dispersant were added, and the mixture was subjected to dispersion treatment with a sand grinder mill for 3 hours to obtain a charge control agent dispersion.

(Production of magenta toner) a) Toner A for development A 19 g of the colorant dispersion A and 1.8 g of the charge control agent dispersion were mixed and stirred with 300 g of the binder resin emulsion A. While stirring, 79 g of 0.5% Al ₂ (SO ₄ ) ₃ was added thereto, the temperature was raised to 60 ° C., and stirring was continued. 2 g of dodecylbenzenesulfonate was added, the temperature was raised to 98 ° C., and stirring was continued for 7 hours. The obtained particles were repeatedly subjected to suction filtration and washing with water, followed by air-drying to obtain 60 g of a magenta toner. When the particle diameter of the obtained particles was measured using a Coulter counter, the volume average diameter was 7.5 μm. For 100 parts of toner, add hydrophobic surface-treated silica to 1 part.
The resulting mixture was mixed and stirred to obtain a developing toner A.

B) Toner B for Development B 300 g of binder resin emulsion A, 15 g of colorant dispersion B and 1.8 g of charge control agent dispersion were mixed and stirred. While stirring, 91 g of 0.5% Al ₂ (SO ₄ ) ₃ was added thereto, the temperature was raised to 60 ° C., and stirring was continued. 2 g of dodecylbenzenesulfonate was added, the temperature was raised to 98 ° C., and stirring was continued for 7 hours. The obtained particles were repeatedly subjected to suction filtration and washing with water, followed by air-drying to obtain 60 g of a magenta toner. When the particle diameter of the obtained particles was measured using a Coulter counter, the volume average diameter was 8.5 μm. 100 parts of toner is treated with 1 part of hydrophobically treated silica
The resulting mixture was mixed and stirred to obtain a developing toner B.

C) Toner C for development C 20 g of the colorant dispersion A and 2 g of the charge control agent dispersion were mixed and stirred with 300 g of the binder resin emulsion B. While continuing the stirring, 108 g of 0.5% Al ₂ (SO ₄ ) ₃ was added thereto, the temperature was raised to 60 ° C., and the stirring was continued. 2 g of dodecylbenzenesulfonate was added, the temperature was raised to 98 ° C., and stirring was continued for 7 hours. The obtained particles were repeatedly subjected to suction filtration and washing with water, followed by air-drying to obtain 60 g of a magenta toner. When the particle diameter of the obtained particles was measured using a Coulter counter, the volume average diameter was 7.5 μm. Toner 1
With respect to 00 parts, 1 part of silica subjected to hydrophobic surface treatment was mixed and stirred to obtain a developing toner C.

Example An unfixed image was formed using an electrophotographic copying machine using a developing toner A as a photosensitive member with an organic photoconductor. This unfixed image is transferred to paper, and the surface thereof is heated using a heating roller fixing machine made of FEP (tetrafluoroethylene-hexafluoropropylene copolymer).
Fixing was performed at a nip width of 5 mm and a fixing speed of 120 mm / sec. At the time of fixing, an anti-offset liquid such as silicone oil was not supplied to the roller. Hot offset did not occur until the fixing roller surface temperature reached 200 ° C.
When the obtained image was visually observed, it was a magenta color with a clear color tone. When the above-mentioned paper was replaced with an OHP sheet, the image was transferred and fixed in the same manner, and when the transmitted image was visually observed, it was clear that the color was magenta. Table 1 shows the evaluation results.

Comparative Example 1 The same operation was performed under the same conditions as in the example, except that the developing toner B was used instead of the developing toner A. Hot offset did not occur until the fixing roller surface temperature reached 200 ° C. When the obtained image was visually observed, the color was much redder than the magenta color. Also, when the transmission image of the OHP sheet was visually observed,
The lightness and chroma were poor and the coloring was poor. First evaluation result
It is shown in the table.

Comparative Example 2 The same operation was performed under the same conditions as in the example, except that the developing toner C was used instead of the developing toner A. Hot offset did not occur until the fixing roller surface temperature reached 180 ° C. When the obtained image was visually observed, it was a magenta color with a clear color tone. Also, O
Visual observation of the transmission image of the HP sheet revealed that the lightness and chroma were inferior and that the magenta color was poor. Table 1 shows the evaluation results.

[0050]

[Table 1]

Spectral reflectance: Measured value with X-Rite938 OHP transmittance: Hitachi spectrophotometer SPECTROHOT
Measure 400nm-700nm with OMETERU-3120 and measure its maximum transmittance-minimum transmittance

[0052]

The magenta toner of the present invention has good spectral reflection characteristics, and is excellent in hot offset resistance and OHP transmittance, so that multicolor superposition is possible, and color reproducibility is good and clear. Gives full-color images of various colors.

 ──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hideko Akai 1000 term of Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Chemical Corporation Yokohama Research Laboratory F-term (reference) 2H005 AA06 AA21 AB06 CA14 CA21 EA03

Claims (9)

[Claims] 1. An electrostatic image developing toner comprising at least a binder resin, a colorant and a wax, wherein the toner comprises a compound represented by the following general formula (I) as a colorant,
In a DSC curve measured by a differential scanning calorimeter,
A toner for developing an electrostatic charge image, which shows a maximum endothermic peak in a range of 50 to 130 ° C. when the temperature is raised. Embedded image (In Formula I, A, B, and C are aromatic rings that may have a substituent.) 2. An electrostatic image developing toner comprising at least a binder resin, a colorant and a wax, containing a compound represented by the following general formula (II) as a colorant, and measuring the toner with a differential scanning calorimeter. A toner curve for developing an electrostatic image, wherein the DSC curve shows a maximum endothermic peak in a range of 50 to 130 ° C. when the temperature is raised. Embedded image (In Formula II, R ¹ , R ⁴ , R ⁵ , and R ⁶ each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydrocarbon group having 5 or less carbon atoms, or a hydrocarbon group having 5 or less carbon atoms. R ² and R ³ each independently represent a hydrogen atom, a halogen atom, a nitro group, a cyano group, a hydrocarbon group having 5 or less carbon atoms, an alkoxy group having 5 or less carbon atoms, and a substituent on the nitrogen atom Represents an aminosulfonyl group which may be substituted or an aminocarbonyl group which may be substituted on a nitrogen atom, provided that an aminosulfonyl group or a nitrogen atom which may be substituted on a nitrogen atom Has at least one aminocarbonyl group in the molecule.) 3. In the general formula (II), R ¹ is a methoxy group, R ² is a hydrogen atom, R ³ is a phenylaminocarbonyl group, R ⁴ is a methoxy group,
3. The toner according to claim 2, wherein R ⁵ is a hydrogen atom and R ⁶ is a chlorine atom. 4. The electrostatic image developing toner according to claim 1, wherein the toner is a polymerized toner. 5. The electrostatic image developing toner according to claim 4, wherein the toner is obtained by mixing and coagulating at least a polymer emulsion, a colorant dispersion, and a wax dispersion. 6. The electrostatic image developing toner according to claim 5, wherein the toner is obtained by mixing and aggregating at least a wax-containing polymer emulsion and a colorant dispersion. 7. The toner according to claim 1, wherein the toner shows a maximum endothermic peak in a range of 60 to 120 ° C. when the temperature is raised, in a DSC curve measured by a differential scanning calorimeter. For developing electrostatic images. 8. The electrostatic image developing toner according to claim 1, wherein the wax is a compound having 16 to 64 carbon atoms. 9. The toner for developing an electrostatic charge image according to claim 8, wherein the wax exhibits a maximum endothermic peak in a region of 50 to 130 ° C. when the temperature is raised, in a DSC curve measured by a differential scanning calorimeter.