JPH08314189A - Magenta toner for heat roll fixation - Google Patents

Abstract

PURPOSE: To obtain a magenta toner having superior color characteristic, transparency to OHP and vinyl chloride resistance and excellent in secondary color reproducibility in the case of addition to other color by incorporating specified polyester resin as a bonding resin and an anthraquinone type magenta dye and a quinacridone type magenta pigment as magenta colorants. CONSTITUTION: This magenta toner contains polyester resin produced from arom. diol represented by the formula and at least one kind of acid component selected from among aliphatic dicarboxylic acids and arom. dicarboxylic acids as a bonding resin and contains an anthraquinone type magenta dye and a quinacridone type magenta pigment as magenta colorants. In the formula, R is ethylene or propylene, each of (x) and (y) is an integer of >=1 and the mean value of (x+y) is 2-7.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a negative toner for fixing a heat roll, which is used in an image forming apparatus such as an electrostatic copying machine or a laser beam printer. More specifically, it has excellent translucency. The present invention relates to magenta toner for heat roll fixing.

[0002]

2. Description of the Related Art Conventionally, the electrophotographic method has been widely used in copying machines, printers, facsimiles, etc., and in recent years, a full-color image forming method has been adopted which reproduces a multicolor image by superposing color toners of a plurality of colors. Has reached the end.

In such an electrophotographic full-color image forming method, image formation is performed by the following process, for example.

First, an electrostatic latent image is formed in dot units on an organic photosensitive member that is negatively and uniformly charged by digital writing such as irradiation with a light beam. This latent image is reverse-developed with negatively charged magenta toner, cyan toner, yellow toner, and any toner selected from black toner as necessary, and the toner image of the specific color thus obtained is formed on the intermediate transfer member. Transcribe. By carrying out the same development and transfer steps in sequence for the above-mentioned other toners, the respective toner images are superimposed on the intermediate transfer member, and the full-color toner image thus obtained is transferred and fixed on the recording paper to obtain a multicolor image. Form an image.

Alternatively, the toner images of the respective colors obtained in the same manner are successively transferred to a recording paper held on a transfer body such as a transfer drum, and the thus obtained full-color toner image is fixed on the recording paper. There is also a method of forming a multicolor image by using.

In the above-mentioned full-color image forming method, it is mainly used for reproducing pictures, photographs, graphic images and the like. Further, the above-described multicolor image reproduced by superimposing color toners of a plurality of colors is not limited to simply forming an image on a recording sheet, but is also commonly used for an overhead projector sheet (OHP sheet). Therefore, the toner has a spectral reflectance corresponding to a desired color, and has an excellent light-transmitting property without hiding the color of the lower layer toner when superposed. Since the obtained multicolor image is often stored in a clear file, etc., the resin that constitutes the toner is plasticized by the plasticizer contained in the clear file, etc. Is required to occur (having excellent vinyl chloride resistance).

In the above-described full-color image forming method, the finally obtained multicolor toner image is fixed on a transfer material such as plain paper in a fixing step. As the fixing method, a heat roll fixing method is used. It is also excellent in high-speed fixability.

The hot roll fixing system is preferable in various points as described above, but in this system, a part of the toner forming an image at the time of fixing is transferred to the surface of the heat roll,
The so-called offset phenomenon in which this re-transfers to a transfer paper or the like sent next and stains the image becomes a problem. Further, there is a possibility that toner components such as colorants may sublime during heating and melting by a hot roll to contaminate the inside of the machine.

In order to prevent the offset phenomenon, various proposals have been conventionally made. One of them is a method in which the toner itself has an offset preventing property by including an offset preventing agent such as wax in the toner or using a resin having a wide molecular weight distribution as a binder resin of the toner. Is a method of fixing while applying a release oil such as silicone oil to the surface of the heat roll.

If the toner used in the above-mentioned full-color image forming method is to have offset prevention performance, the toner itself will be a factor of lowering the translucency. On the other hand, the toner used in the oil coating type heat roll fixing method is required to have a toner component which is not dissolved in oil.

Conventionally known organic pigments and dyes have been used as colorants used in magenta toners, but each has various drawbacks. For example, organic pigments are generally superior in heat resistance and light resistance as compared with dyes, but since they exist in a state of being dispersed in the toner in the form of particles, the hiding power becomes strong and the light transmittance decreases. Will end up. In addition, due to the light scattering by the particles dispersed in the toner, the spectral reflection characteristic for accurately reproducing the original cannot be obtained, and due to the strength of the above-mentioned concealing power, sufficient translucency cannot be obtained. When it is used for an OHP sheet because it cannot be obtained,
It has drawbacks such as a dark projected image and low saturation. Since the dye is generally present in a state of being dissolved in the binder resin of the toner, it is excellent in translucency and color saturation, but has a drawback of low heat resistance and light resistance. Since light resistance is low and color fading occurs due to light, there arises a problem that even if an image with excellent saturation is obtained, it cannot be maintained for a long period of time. Further, due to its low heat resistance, when used in the above-mentioned heat roll fixing method, the dye is liable to sublimate in the vicinity of the fixing portion to cause in-machine contamination, and is dissolved in silicone oil and finally fused to the heating roll. There was a problem of causing an offset phenomenon.

[0012]

DISCLOSURE OF THE INVENTION An object of the present invention is to provide a magenta toner having excellent color characteristics, OHP translucency and vinyl chloride resistance, and to be fixed by using a heat roll fixing device. Another object of the present invention is to provide a negatively chargeable magenta toner that does not cause contamination in the machine and, in particular, does not contaminate the fixing oil applied to the hot roll with the colorant.

A further object of the present invention is to provide a magenta toner for a full color toner which has excellent secondary color reproducibility when superposed with a yellow toner or a cyan toner.

[0014]

The present invention provides a binder resin represented by the following formula (1):

[0015]

Embedded image

(Wherein R represents an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 7), and an aliphatic diol Containing a polyester resin obtained from at least one acid component selected from the group consisting of dicarboxylic acids and aromatic dicarboxylic acids, and containing an anthraquinone magenta dye and a quinacridone magenta pigment as a magenta colorant The present invention relates to a heat roller fixing magenta toner.

In the above-mentioned full-color image forming method, it is desirable to use a negatively chargeable organic photoconductor from the viewpoint of cost and electrostatic characteristics. Magenta to be used in relation to such a negatively chargeable photoreceptor in which an electrostatic latent image is formed on the basis of image information by digital exposure using a laser beam or a shutter array and development is performed by a reversal development method. There is a demand for a negatively charged magenta toner that is excellent as a toner.

The magenta toner for heat roll fixing of the present invention is a negatively chargeable toner containing at least a specific polyester resin and two specific types of magenta colorants.

In the toner of the present invention, the polyester resin used as the binder resin has at least the following formula (1) as an alcohol component.

[0020]

[Chemical 4]

(R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 7), an aliphatic dicarboxylic acid and an aromatic diol. It is a polyester resin obtained by polycondensing at least one acid component selected from the group consisting of dicarboxylic acids.

In the present invention, the polyester resin is used as the binder resin because the polyester resin itself has a negative charge property, so that a negative charge control agent is not essential in obtaining a negative charge toner, or Even when used, it is advantageous that the addition amount can be made small, while on the other hand, when using a styrene-acrylic resin, it is difficult to satisfy both properties of light transmission and heat resistance, This is because there is a further drawback that the vinyl chloride resistance of the resin is low.

Examples of the aromatic diol represented by the above formula (1) used in the above polyester resin include polyoxypropyleneated bisphenol A and polyoxyethylenated bisphenol A.

In addition to the above aromatic diols, for example, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol,
1,3-propylene glycol, 1,4-butanediol, neopentyl glycol and other diols, sorbitol, 1,2,3,6-hexanetetrol, 1,4-
Sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butane Polyols such as triol, trimethylolethane, trimethylolpropane, and 1,3,5-trihydroxymethylbenzene may be used.

The aliphatic dicarboxylic acids used in the above polyester resin include fumaric acid, maleic acid, succinic acid, aliphatic dicarboxylic acids such as C 4-18 alkyl or alkenyl succinic acids, their acid anhydrides or their lower acids. An alkyl ester or the like can be used.

As aromatic dicarboxylic acids, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, their acid anhydrides or their lower alkyl esters, and the like can be used. Further, a polyvalent carboxylic acid such as trimellitic acid may be used in a small amount in order to adjust the acid value of the resin as long as the translucency of the toner is not impaired. Examples of such a polyvalent carboxylic acid component include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid,
1,2,4-naphthalene tricarboxylic acid, 1,2,4-
Butanetricarboxylic acid, 1,2,5-hexanenetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-
Methylene carboxy propane, 1,2,4-cyclohexane tricarboxylic acid, tetra (methylene carboxylic)
Methane, 1,2,7,8-octane tetracarboxylic acid,
Pyromellitic acid, anhydrides thereof, lower alkyl esters and the like can be mentioned.

Among the various alcohol components and acid components described above, polyoxyethylenated bisphenol A and polyoxypropyleneated bisphenol A are used in combination as aromatic diols, and aromatic dicarboxylic acid and aliphatic dicarboxylic acid are used as acid components. The linear polyester resin obtained by using and is preferred.

The linear polyester resin used in the present invention has an acid value of 1.0 to 35.0 mgKOH / g, a hydroxyl value of 10.0 to 40.0 mgKOH / g, and a molecular weight by gel permeation chromatography (GPC). The number average molecular weight (Mn) measured by distribution is 3,000 to 10,000, preferably 3,000 to 7,000, and the weight average molecular weight (Mw) is 7,000 to 50,000, preferably 7,000 to 1,500.
0, molecular weight distribution (Mw / Mn) is 1.0 to 5.0, preferably 1.5 to 3.0, endothermic peak value (T by DSC)
g) is 50 to 70 ° C., the softening temperature (Tm) by a flow tester is 90 to 110 ° C., and the apparent melt viscosity at 90 ° C. is 1 × 10 ^{5 to} 5 × 10 ⁶ poise. If these characteristics are not satisfied, it becomes impossible to sufficiently satisfy the translucency of the toner, the dispersibility of the colorant and the charge control agent, the fixability and the heat resistance. Specifically, by setting the acid value in the above range, the negative chargeability of the toner can be improved, and by setting the hydroxyl value in the above range, the charging stability can be improved.
When the molecular weight distribution is within the above range, the sharp melt property of the toner can be improved during fixing and the light-transmitting property can be improved. Further, by setting the glass transition point and the softening point within the above ranges, it is possible to impart sufficient heat resistance and fixability to the toner.

The linear polyester resin used in the present invention does not substantially contain a tetrahydrofuran insoluble component and is soluble in tetrahydrofuran. It is not preferable to contain a tetrahydrofuran-insoluble component because it causes the light-transmitting property of the toner to be impaired.

As the magenta colorant used in the present invention, an anthraquinone magenta dye and a quinacridone magenta pigment are used in combination. That is, by using the anthraquinone-based magenta dye, the clarity and translucency to OHP which cannot be achieved by only the pigment-based magenta coloring agent is improved, and by using the quinacridone-based magenta pigment together, a single coloring agent can be obtained. When used, it is possible to expand the secondary color reproduction area (color reproduction area due to color mixture with yellow toner, cyan toner, and black toner) that is difficult to reproduce.

That is, in the magenta toner containing only the anthraquinone magenta dye as a colorant, there is room for improvement in the above-mentioned secondary color reproducibility, and for example, a bluish color in the secondary color reproducibility with the cyan toner. Although it is at a practical level in terms of color reproducibility and human skin color reproducibility, more excellent secondary color reproducibility is desired. On the other hand, when the quinacridone-based magenta pigment is used alone as a colorant, the positive charge of the quinacridone-based pigment adversely affects the negative chargeability of the toner, resulting in image fog and the like.
Problems such as insufficient clarity and translucency for OHP and insufficient secondary color reproducibility occur.

On the other hand, in the present invention, by using the anthraquinone-based magenta dye and the quinacridone-based magenta pigment in combination, the sharpness with respect to OHP and the
It has been found that the reproducibility of the next color can be improved, and that the anthraquinone-based magenta dye having a negative charge to the positive charge of the quinacridone-based pigment can eliminate the adverse effect on the chargeability of the toner. is there.

As the anthraquinone type magenta dye used in the present invention, known ones can be used, but it is preferable to use the compound represented by the following general formula (2).

[0034]

Embedded image

In the above formula (2), R'represents a hydroxyalkyl group, an alkoxyalkyl group, an alkylaminosulfonyl group, an alkoxyalkylaminosulfonyl group, an alkylcarboxyalkyl group, and A represents an oxygen atom or a sulfur atom.

Usually, the 1-amino group in the structure controlling color development of anthraquinone dye is thermally unstable,
The decomposition of this group causes deterioration in color resistance, but in the anthraquinone dye represented by the above formula (2),
It is considered that the nitrogen atom of the 1-amino group is chemically stabilized by the presence of the 2-phenoxy group, and the heat resistance is improved. Further, it is considered that the presence of the substituent R ′ hinders the solubility in silicone oil and can increase the entire molecular weight, so that it has excellent sublimation resistance. Therefore, the toner using the above-mentioned anthraquinone dye is excellent in sublimation resistance at the time of heating in heat roll fixing and resistance to dissolution in silicon oil, and also excellent in light resistance, so that image formation without contamination inside or outside the machine is possible. Can be realized. Further, by combining the anthraquinone dye and a specific linear polyester resin, a magenta toner having excellent dispersibility (solubility) of the colorant, excellent clarity and light transmission, and excellent fixability and heat resistance can be obtained. Obtainable.

Examples of the anthraquinone dye represented by the above formula (2) include, but are not limited to, those shown in the following (a) to (f).

[0038]

[Chemical 6]

Among the anthraquinone dyes represented by the above formula (2), it is preferable to use one having a molecular weight of 400 or more from the viewpoint of solubility in silicone oil and resistance to sublimation. EX-59 (manufactured by Mitsui Toatsu Dye Co., Ltd.) can be used as such an anthraquinone dye.

Further, 150 of the above-mentioned anthraquinone dyes
The blow-off triboelectric charge amount for iron powder particles of mesh pass, 250 mesh on is -1 to -20 μc / g,
In combination with the above polyester resin, it imparts good negative chargeability to the toner.

As the quinacridone-based magenta pigment used in the present invention, known pigments can be used, but especially C.I. I. Pigment Red 122 is preferably used, for example, Hostaperm Pink
EB Tonergrade VP2301 (manufactured by Hoechst Industry Co., Ltd.) and the like can be mentioned.

In the present invention, the magenta colorant is used in an amount of 0.5 to 10 parts by weight, preferably 1.0 to 4.0 parts by weight, based on 100 parts by weight of the binder resin. When the amount of the magenta colorant used is less than 0.5 part by weight, a sufficient image density cannot be obtained, and when it is more than 10 parts by weight, the light transmissivity of the toner is lowered and the color tone and the charging property are affected. Therefore, it is not preferable.

The anthraquinone dye and the quinacridone pigment are preferably used in a weight ratio of 9: 1 to 1: 3, preferably 4: 1 to 1: 1.

In addition to the above colorants, desired additives such as a charge control agent may be added to the toner of the present invention.

As the charge control agent, a colorless, white or pale color negative charge control agent can be used. For example, a salicylic acid metal complex such as a zinc complex of a salicylic acid derivative, a calixarene compound, a fluorine-containing quaternary ammonium salt compound can be used. It is preferable to use a negative charge control agent such as. Examples of the salicylic acid metal complex include, for example, JP-A-53-127.
No. 726, JP-A No. 62-145255, and the like, and examples of the calixarene compound include those described in, for example, JP-A No. 2-201378, and fluorine-containing quaternary ammonium salt compounds. For example, those described in JP-A-3-1162 can be used.

Further, in order to control the charge amount of the toner and improve the rising property of the charge, a charge control agent such as a salicylic acid metal complex or a calixarene compound is used.
A fluorinated quaternary ammonium salt compound may be used in combination.

When such a negative charge control agent is added, it is preferably used in an amount of 0.1 to 10 parts by weight, preferably 0.5 to 4.0 parts by weight, based on 100 parts by weight of the binder resin. In the toner of the present invention, it is preferable to add and mix a post-treatment agent from the viewpoint of improving the fluidity of the toner.

As such a post-treatment agent, for example, silica, alumina, titania, tin oxide, zirconium oxide and the like can be used alone or in admixture of two or more.

The above post-treatment agent is preferably subjected to a hydrophobizing treatment from the viewpoint of environmental stability. As the hydrophobizing agent, various coupling agents such as silane-based, titanate-based, aluminum-based and zircoaluminate-based coupling agents and Silicone oil or the like is used.

As the above-mentioned post-treatment agent, it is preferable to use hydrophobic silica and hydrophobic titania, or hydrophobic silica and hydrophobic alumina, from the viewpoints of fluidity and environmental stability of charging. The amount of post-treatment agent added is 0.3 to
It is preferable to add 2.0% by weight.

In the toner of the present invention, it is preferable from the viewpoints of production cost and production stability that the above-mentioned polyester resin and colorant and, if desired, other components are produced by a kneading / pulverizing method. The kneading / pulverizing method includes a step of mixing toner components such as a resin and a colorant with a mixer such as a Henschel mixer, a step of melting / kneading the mixture, a step of coarsely pulverizing the kneaded material after cooling, and a coarsely pulverized particle. The toner is manufactured by a step of finely pulverizing and finely pulverizing the obtained finely pulverized particles.

The volume average particle diameter of the toner of the present invention is preferably adjusted to 4 to 9 μm from the viewpoint of high-definition image reproducibility.

The toner of the present invention can be used as a two-component developer which is used by mixing with a carrier or a one-component developer which does not use a carrier.

As the carrier used in combination with the toner of the present invention, those conventionally known as carriers for two-component developers can be used. For example, carriers composed of magnetic particles such as iron and ferrite, A resin-coated carrier obtained by coating such magnetic particles with a resin,
Alternatively, it is possible to use a binder type carrier or the like formed by dispersing magnetic fine powder in a binder resin. Among these carriers, silicone resin as the coating resin,
It is possible to use a resin coated carrier using a copolymer resin (graft resin) of an organopolysiloxane and a vinyl monomer or a polyester resin, or a binder type carrier using a polyester resin as a binder resin. From the viewpoint of the above, it is preferable to use a carrier having an average particle diameter of 30 to 60 μm.

In the present invention, the above-mentioned toner can be fixed on a transfer material such as recording paper by using an oil coating type heat roll fixing device. As such a heat roll fixing device, a known one can be used and is not particularly limited, but for example, a silicone rubber coating layer is provided on a core metal such as aluminum having a built-in heater via a primer layer. Fixing provided with a heating roll provided, a pressure roll in which a silicone rubber coating layer is provided on a core metal of aluminum or the like having a built-in heater via a primer layer, and an oil application unit for applying silicone oil to the heating roll The container can be preferably used. A filler such as silica may be added to the silicone rubber layer, and the layer structure is not limited to a single layer structure but may be a two layer structure or a three layer structure.

[0056]

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited to the following examples, and various modifications can be made.

<Production Example of Magenta Toner A> Bisphenol A propylene oxide (P
O) and bisphenol A ethylene oxide (E
O), fumaric acid (FA) and terephthalic acid (TPA) as acid components (PO) :( EO) :( FA):
Polyester resin obtained by condensation at a molar ratio of (TPA) = 5: 5: 5: 4 (acid value: 3.1 mg KOH / g, O
H value: 32.0 mgKOH / g, number average molecular weight (M
n): 6600, weight average molecular weight (Mw): 1500
0, glass transition point: 59.0 ° C, softening point: 95.2 ° C,
Apparent melt viscosity at 90 ° C .: 4.0 × 10 ⁵ poi
se) 100 parts by weight of anthraquinone dye (TON. Red. EX-59: manufactured by Mitsui Toatsu Dyes Co., Ltd.) 3
By weight, 2.0 parts by weight of a zinc complex of a salicylic acid derivative (E-84: manufactured by Orient Chemical Industry Co., Ltd.) as a charge control agent were sufficiently mixed with a Henschel mixer, kneaded with an extruder, and then cooled. The obtained kneaded product was roughly pulverized with a feather mill and then finely pulverized with a jet pulverizer. The obtained finely pulverized product was classified to obtain toner particles having a volume average particle diameter of 8.0 μm.

Magnesium toner A was obtained by adding 0.5% by weight of silica fine powder (H2000: Hoechst Co.) to the toner particles and mixing them with a Henschel mixer.

The acid value of the resin was determined as follows. First, 2 to 10 g of resin is weighed and dissolved in 50 ml of toluene. Using a mixed indicator of 0.1% bromthymol blue and phenol red, titration was performed with a pre-standardized N / 10 potassium hydroxide / alcohol solution, and the acid value was calculated from the consumption amount of the N / 10 potassium hydroxide / alcohol solution. calculate.

Acid value = 5.61 (mg) × KOH (ml)
× N / resin amount (mg) The molecular weight distribution was measured using gel permeation chromatography 807-IT type (Nippon Bunko Kogyo).
The non-aqueous column was kept at 40 ° C by a column oven, and tetrahydrofuran was used as a carrier solvent at 1 kg / cm ²
I'll throw it away. 30 mg of resin is replaced with 20 of tetrahydrofuran
0.5 ml of this solution was introduced into the apparatus together with a carrier solvent, and the molecular weight was determined by polystyrene conversion.

The glass transition point is a differential scanning calorimeter DS
It measured using C-200 (made by Seiko Instruments Inc.). Precisely weigh 5 to 20 mg of toner, preferably 10 mg, and put it in an aluminum pan. As a reference, alumina was put in an aluminum pan.
The temperature was raised from room temperature to 200 ° C. at 0 ° C./min to perform melt quenching, followed by cooling and heating at a heating rate of 10 ° C./min for 20
The measurement is performed between 120 ° C. During this heating process, 30 ~
The temperature at which the main endothermic peak in the range of 80 ° C. was obtained was taken as the endothermic peak value (glass transition point).

The softening temperature and apparent melt viscosity were measured using a flow tester CFT-500 (manufactured by Shimadzu Corporation). 1.0 to 1.5 g of the toner is weighed, and a molding machine is used to apply pressure of 180 kg / cm ² for 1 minute.
This pressurized sample was subjected to flow tester measurement under the conditions shown in Table 1 below, and the temperature at which the sample flowed out in an amount of 1/2 was taken as the softening temperature, and the apparent melt viscosity at 90 ° C. was determined from the temperature-apparent viscosity curve. .

[0063]

[Table 1]

<Production Example of Magenta Toner B> In the production example of Magenta Toner A, 2.25 parts by weight of anthraquinone dye (TON. Red. EX-59: manufactured by Mitsui Toatsu Dyes Co., Ltd.) and a quinacridone pigment ( Hos
tapem Pink EB Tonergrade
VP2301: Hoechst Industry Co., Ltd.) 0.75
Magenta Toner B was obtained in the same manner except that 1 part by weight was used.

<Production Example of Magenta Toner C> Magenta Toner C was obtained in the same manner as in Production Example of Magenta Toner B, except that 1.5 parts by weight of the anthraquinone dye and 1.5 parts by weight of the quinacridone pigment were used. .

<Production Example of Magenta Toner D> Magenta Toner C was obtained in the same manner as in Production Example of Magenta Toner B, except that 0.75 parts by weight of the anthraquinone dye and 2.25 parts by weight of the quinacridone pigment were used. .

<Production Example of Magenta Toner E> In the production example of magenta toner A, a quinacridone type pigment (Hostaperm Pink EB To) is used as a magenta colorant.
magenta toner E was obtained in the same manner except that only 3 parts by weight of Nergrade VP2301: Hoechst Industry Co., Ltd.) was used.

<Production Example of Magenta Toner F> In the production example of magenta toner A, C.I. I.
Pigment Red 57: 1 (SEIKAFAS
Magenta Toner F was obtained in the same manner except that only 3 parts by weight of T CARMINE 6B 1476T-7 (manufactured by Dainichiseika Co., Ltd.) was used.

<Production Example of Yellow Toner> In the production example of magenta toner A, C.I. I. Pigme
A yellow toner was obtained in the same manner except that 3 parts by weight of ntY-17 (KET Yellow 403: manufactured by Dainippon Ink and Chemicals, Inc.) was used.

<Cyan Toner Production Example> Magenta Toner A
In the production example, C.I. I. Pigmen
A cyan toner was obtained in the same manner except that 3 parts by weight of tBlue 15-3 (KET Blue 104: manufactured by Dainippon Ink and Chemicals, Inc.) was used.

<Production Example of Black Toner> In the production example of magenta toner A, carbon black (M
A-8: manufactured by Mitsubishi Chemical Co., Ltd.) A black toner was obtained in the same manner except that 3 parts by weight was used.

As the carrier, the polyester resin-coated ferrite carrier obtained by the following production example was used and mixed with each toner so that the toner concentration was 6% by weight to prepare a two-component developer.

<Example of carrier production> C having an average particle diameter of 45 μm
The u-Zn ferrite particles were coated with a polyester resin solution containing ethylene glycol and neopentyl glycol as alcohol components and isophthalic acid and terephthalic acid as acid components so that the coating amount after drying was 0.4% by weight. After drying, it was crushed to obtain a polyester resin-coated ferrite carrier.

The following evaluations were performed using the above two-component developer.

<Evaluation of Mixed Color Reproduction Range with Yellow Toner and Mixed Color Reproduction Range with Cyan Toner> Using the above-mentioned developers, a reversal development system equipped with a negatively chargeable organic photoconductor and a silicone oil coating type fixing device is used. Full color copier (CF-
80: manufactured by Minolta Co., Ltd., and the development amount of each of magenta toner, yellow toner and cyan toner is 0.7 mg.
/ Cm ² and so as to adjust, to form a mixed color image with color mixing image and the magenta toner and the cyan toner of the magenta toner and the yellow toner.

For the obtained image, a spectrocolorimeter CM-
The color coordinates of the La ^* b ^* coordinate space were measured with 1000 (manufactured by Minolta), and the saturation c ^* was calculated by the following formula.

[0077]

[Equation 1]

Color mixing with yellow toner (saturation of red)
Is particularly excellent (c ^* is 70 or more) is "◎",
Excellent (c ^* is 65 or more and less than 70) is "○",
Practical range (c ^* of 60 or more and less than 65) was evaluated as “Δ”, and practical problem (c ^* of less than 60) was evaluated as “x”. Table 2 shows the results.

Color mixing property with cyan toner (saturation of blue)
Is especially excellent (c ^* is 60 or more), "◎",
"Excellent" (c ^* is 55 or more and less than 60) is excellent,
A practical range (c ^* of 50 or more and less than 55) was evaluated as “Δ”, and a practical problem (c ^* of less than 50) was evaluated as “x”. Table 2 shows the results.

<Evaluation of Image Fog> An image development test was conducted on the developer using each of the magenta toners described above using a full-color copying machine (CF-80: manufactured by Minolta Co., Ltd.), and the image fog of the obtained image was visually evaluated. . If there is no fog in the image, it is "A", if there is a slight fog but it is not a problem level, it is "○", if it is a little fogging, but it is in the practical range, "△", there is fog. Those that occurred and were practically problematic were evaluated as "x". Table 2 shows the results.

<Evaluation of light resistance> A developer using each of the magenta toners described above was subjected to an image output test with a full-color copying machine (CF-80: manufactured by Minolta Co., Ltd.) to evaluate the light resistance of the obtained image. Therefore, a forced irradiation test was conducted for 6 hours using a feed meter. Those that were not discolored at all were evaluated as “⊚”, those that were slightly faded but had no practical problems were evaluated as “◯”, and those that were discolored and had practical problems were evaluated as “x”. Table 2 shows the results.

<Evaluation of sublimability (contamination property in machine)> 0.2 g of the coloring agent used for each magenta toner was put in a crucible, CF paper was sandwiched inside the lid of the crucible, and the lid was closed at 180 ° C.
Heated for 6 hours. In addition, a full-color copying machine (CF-8
0: manufactured by Minolta Co., Ltd.) was used to observe the contamination in the actual machine when 100,000 sheets were printed. Those that have not sublimated to paper at all are "◎", those that are slightly reddish but have a level that does not pose a problem in the actual machine are "○", and paper is reddish and even in the actual machine The case where contamination was recognized was evaluated as “△”, and the case where the paper was dyed red and severely contaminated in the actual machine was evaluated as “x”. Table 2 shows the results
Shown in

<Evaluation of skin color reproducibility> A full-color copying machine (CF-8) was used using the above-mentioned four color developers (magenta toner, yellow toner, cyan toner and black toner).
0: manufactured by Minolta Co., Ltd., and the skin color reproducibility of the copied image of the test chart (Electrophotographic Society Test Chart No. 5-1) was visually evaluated. "Excellent" for all of hue, saturation, and brightness, "○", although the hue is slightly biased to bluish or reddish, but there is no problem as skin color is "○", hue, saturation, At least one of the brightness has a drawback,
Those having a slightly problematic skin color were evaluated as “Δ”, and those far from the skin color were evaluated as “x”. Table 2 shows the results.

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[Table 2]

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The magenta toner of the present invention has excellent color characteristics, translucency and vinyl chloride resistance, is excellent in sublimation resistance and solubility in fixing oil, and further,
Excellent secondary color reproducibility when used in combination with yellow toner, cyan toner or black toner.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Junichi Tamaki 2-3-13 Azuchi-cho, Chuo-ku, Osaka, Osaka International Building Minolta Co., Ltd. (72) Inventor Hiroyuki Fukuda 2-3-3 Azuchi-cho, Chuo-ku, Osaka No. 13 Osaka International Building Minolta Co., Ltd.

Claims (3)

[Claims] 1. A binder resin having the following formula (1): (Wherein R represents an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 7), an aliphatic dicarboxylic acid, and Containing a polyester resin obtained from at least one acid component selected from the group consisting of aromatic dicarboxylic acids, and containing an anthraquinone magenta dye and a quinacridone magenta pigment as a magenta colorant. Characteristic magenta toner for heat roll fixing. 2. The anthraquinone-based magenta dye is represented by the following formula (2): (Wherein R'represents a hydroxyalkyl group, an alkoxyalkyl group, an alkylaminosulfonyl group, an alkoxyalkylaminosulfonyl group, an alkylcarboxyalkyl group, and A represents an oxygen atom or a sulfur atom). The magenta toner for heat roll fixing according to claim 1. 3. The quinacridone-based magenta pigment is C.I.
I. The magenta toner for heat roll fixing according to claim 1, wherein the magenta toner is a compound classified as Pigment Red 122.