JP2003202706A - Dry toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide dry toners which excel in coloring power and make bright colors obtainable. <P>SOLUTION: The dry toners contain at least a binder resin, quinacridone coloring agent and monoazo coloring agent and sulfureous polymer in which the total content of the quinacridone coloring agent and monoazo coloring agent in the toners is 1 to 20 mass% and the mass ratio of the content is the quinacridone coloring agent: the monoazo coloring agent = 25:75 to 75:25. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used in a recording method using an electrophotographic method, an electrostatic recording method, a magnetic recording method, a toner jet method or the like. More specifically, the present invention relates to a copying machine, a printer, a facsimile,
The present invention relates to a magenta toner used in an image recording device that can be used in a plotter or the like.

[0002]

2. Description of the Related Art In recent years, digital full-color copying machines and printers have been put into practical use, and high-quality images having excellent color reproducibility without color unevenness as well as resolution and gradation have been obtained.

In a digital full-color copying machine, a color image original is color-separated by B (blue), G (green), and R (red) color filters, and then a dot diameter of 20 to 70 μm corresponding to the original image is obtained. A latent image
(Yellow), M (magenta), C (cyan), Bk
A large amount of toner is transferred from the photoconductor to the intermediate transfer body or not, compared to a black-and-white copying machine, which reproduces by using the subtractive color mixing action at the time of heat and pressure fixing, using each color toner of (black). It is necessary to transfer to a transfer material.

Among the color toners, the magenta toner is important for reproducing the flesh color, and since the flesh tone of a human image is a halftone, excellent developability is also required.

Conventionally, a toner obtained by kneading a pigment, which is a coloring agent, and a charge control agent together with a thermoplastic resin and pulverizing the toner has been generally used in the electrophotographic system. In this case, particularly in the magenta toner, the coloring power is not enhanced because the pigment that is the colorant is difficult to disperse, and the dispersed particles of the pigment scatter light to easily cause the problem of decreasing the transparency of the toner. . Therefore, the color reproducibility of a multicolor image formed by superimposing a plurality of color toners is poor, and the projected image of an image formed by transferring and fixing it on a transparent sheet for an overhead projector (OHP) is dark and vivid. It had the drawback of being less frequent. In particular, the problems as described above tend to occur when the toner is manufactured by the suspension polymerization method or the emulsion polymerization method.

To solve these problems, improvements in pigments and dyes, which are mainly used in magenta toners, and improvements in which pigments and dyes are used in combination have been proposed. For example, JP-A 1-222477
JP-A No. 7-75 discloses that a clear magenta toner is obtained by using a quinacridone pigment and a xanthene dye in combination, and the light resistance is improved. Further, JP-A-2-13968 discloses that by using a quinacridone pigment and a methine pigment in combination, a clear color image can be obtained without contaminating the fixing roller.

On the other hand, in JP-A-11-52625, C.I. I. Pigment Red 48 and a red pigment such as a quinacridone pigment having a b ^* value of -5 or less in the L ^* a ^* b ^* color system in a mixing ratio of 2 to 30% by mass based on all pigments. There is disclosed a method in which a toner of good magenta color is obtained, the charging property and the light resistance of the toner are improved, and the heat resistance to the fixing roller is also improved by the combined use of the above.

However, even with these proposals,
1) It has excellent spectral reflection characteristics for color reproduction and has a clear magenta color. 2) It has good dispersibility of a coloring agent in a resin and has high coloring. 3) It has stable triboelectrification characteristics in the environment. No 4) magenta toner that sufficiently satisfies all required characteristics such as good transparency.

The toner applied to the dry developing method is generally colored resin fine particles (toner particles) containing a binder resin, a colorant and a wax component as main components,
Usually, the particle diameter is about 6 to 15 μm in number average diameter. As a method for producing a toner composed of such colored resin fine particles, a binder resin, a coloring agent such as a dye / pigment and / or a magnetic material, a wax component, etc. are melted and ground, and the kneaded product is cooled.
Generally, the toner is obtained by a so-called pulverization method, in which toner particles are obtained by pulverizing and pulverizing the pulverized material.

The toner obtained by such a method is required to have a positive or negative charge depending on the charging polarity of the electrostatic image to be developed. In order to allow the toner to retain an electric charge, the triboelectric charging property of the binder resin, which is the main component of the toner, can be used, but this alone results in a low charging property of the toner. Therefore, a charge control agent is added to the toner in order to impart a desired triboelectric chargeability to the toner. A toner containing such a charge control agent may exhibit a relatively high triboelectric charge amount, but in general, the toner charge amount under high humidity and the charging speed under low humidity are observed.

One of the causes is adsorption and desorption of water in the toner particles and in the vicinity of the charge control agent existing on the surface of the toner particles. It is thought that this affects the charging characteristics of

[0012] As charge control agents known in the art, negative charge agents include metal complex salts of monoazo dyes, metal complex salts of salicylic acid, metal complex salts of naphthoic acid, metal complex salts of dicarboxylic acids, and copper. Examples include phthalocyanine pigments.

Many of the above charge control agents have a sufficiently high charge imparting ability, but the controllability is poor, so that the binder resin and other materials that can be used are limited.

On the other hand, Japanese Patent Application Laid-Open No. 63-184762 discloses a toner containing a charge control resin having acrylamidomethylpropanesulfonic acid as a constituent monomer, and Japanese Patent Application Laid-Open No. 8-123096 specifies the charge control resin. Discloses a technique relating to a toner in which the Fe complex salt of the monoazo dye is used in combination, and the abundance ratio of the Fe complex salt of the monoazo dye in the toner is specified. However, since the charge control resin has good dispersibility in the binder resin, in the former case, it was necessary to increase the addition amount in order to efficiently exhibit the charge control ability. Further, the coloring power of the toner is not considered at all. On the other hand, in the latter case, matching with the image forming apparatus is improved to some extent by specifying the abundance ratio of the Fe complex salt of the monoazo dye in the toner, but the chargeability of the toner itself is not affected by the environment of use. Not only there is room for improvement, but it is essential to use a chromatic color charge control agent, which makes it extremely difficult to apply it to color toners.

[0015]

SUMMARY OF THE INVENTION An object of the present invention is to provide a dry toner which solves the above problems.

That is, it is an object of the present invention to provide a dry toner which is excellent in coloring power and can obtain a clear color. A further object of the present invention is to provide a dry toner having a wide color space of a projected image in a fixed image of an OHP sheet and excellent transparency. A further object of the invention is
An object of the present invention is to provide a dry toner which has excellent negative chargeability and can achieve good electrophotographic characteristics.

[0017]

The present invention provides at least a binder resin, a quinacridone colorant and a monoazo colorant,
A dry toner containing a sulfur-containing polymer, wherein the total content of the quinacridone colorant and the monoazo colorant in the toner is 1 to 20% by mass, and the mass ratio of the contents is quinacridone colorant: monoazo. Colorant = 25: 75 to 75: 2
And a dry toner.

[0018]

BEST MODE FOR CARRYING OUT THE INVENTION The dry toner of the present invention is a dry toner containing at least a binder resin, a quinacridone colorant and a monoazo colorant, and a sulfur-containing polymer, and the quinacridone colorant in the toner is used. And the total content of the monoazo colorant is 1 to 20% by mass, and the mass ratio of the contents is quinacridone colorant: monoazo colorant = 25: 75 to 7.
It is characterized by being 5:25.

As a result of earnest studies, the inventors of the present invention selected / blended the colorant in the toner as described above, and added a sulfur-containing polymer to the toner, thereby developing the toner, developing the color tone and coloring the toner. The inventors have found that it is possible to improve the balance of strength, light resistance, charging characteristics, etc., and have completed the present invention.

According to the knowledge of the present inventors, by selecting / blending the colorant in the toner as described above and incorporating the sulfur-containing polymer in the toner, the developing characteristics of the toner can be improved.
Color tone, tinting strength, light resistance, charging characteristics, etc. are improved in a well-balanced manner. Although these reasons are not necessarily clear, re-aggregation of each pigment composition itself is suppressed by mixing a quinacridone colorant and a monoazo colorant having a similar primary particle structure in the toner particles. The coexistence effect based on the interaction between the pigment compositions creates a relatively gradual re-aggregation state between both pigment compositions, thereby imparting desirable color developability, and at the time of toner production, the sulfur-containing polymer is It is considered that by further functioning as a dispersant and further improving the dispersibility of the colorant, the color tone, the coloring power, the transparency and the charging property are significantly improved. Further, reaggregation of each pigment composition itself is suppressed, and at the surface of the toner particle, the charge control effect of the sulfur-containing polymer present on the surface of the particle is used to impart charge to the toner particle and prevent retention of reverse charge. Therefore, it is presumed that the toner is provided with desirable developing characteristics and charging characteristics.

Examples of the quinacridone colorant according to the present invention include pigment compositions represented by the following structural formula [1], and these can be used alone or in combination.

[0022]

[Chemical 4] [X ₁ and X ₂ represent a hydrogen atom or a substituent selected from an alkyl group, an alkoxy group and a halogen group. ]

Among these, C.I. I. Pigment
Red 122, C.I. I. Pigment Red
202, or C.I. I. Pigment Violet
19 (each according to the name described in the Color Index Fourth Edition) is preferably used from the viewpoint of physical stability such as hue and light resistance.

On the other hand, examples of the monoazo colorant according to the present invention include pigment compositions represented by the following structural formula [2], and these can be used alone or in combination.

[0025]

[Chemical 5] [R ₁ , R ₂ and R ₃ are each a hydrogen atom, an alkyl group,
A substituent selected from an alkoxy group, a halogen atom, a nitro group, anilide, and a sulfamoyl group is shown. R ₄ is selected from the following group, and the substituents R _{5 to} R ₈ in the following group are substituents selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group and a nitro group. ]

[0026]

[Chemical 6]

Among these, C.I. I. Pigment
Red 5, C.I. I. Pigment Red 3
1, C.I. I. Pigment Red 146, C.I.
I. Pigment Red 147, C.I. I. Pig
ment Red 150, C.I. I. Pigment
Red 176, C.I. I. Pigment Red 1
84, C.I. I. Pigment Red 185, or C.I. I. PigmentRed 269 (each according to the name described in Color Index Fourth Edition) is preferably used from the viewpoints of improving dispersibility by suppressing reaggregation of the quinacridone colorant, and further improving color developability and charging characteristics.

The total content of the quinacridone colorant and the monoazo colorant in the dry toner of the present invention is 1 to 20% by mass,
It is preferably 3 to 10% by mass, and the mass ratio of the contents of the two is blended so as to satisfy the quinacridone colorant: monoazo colorant = 25: 75 to 75:25.

When the total content of the quinacridone colorant and the monoazo colorant in the toner is less than 1% by mass, the function as the colorant cannot be sufficiently achieved. Also, 2
If it exceeds 0% by mass, the existing state of the colorant in the toner particles becomes excessive, the coexisting effect of the quinacridone colorant and the monoazo colorant disappears, and the reaggregation of the colorant progresses, resulting in a transparent state. Properties and charging characteristics are adversely affected.

The mass ratio of the content of the quinacridone colorant to the content of the monoazo colorant is quinacridone colorant:
When the monoazo colorant is out of the range of 25:75 to 75:25, the coexistence effect disappears, and when the content ratio of the monoazo colorant is less than 25% by mass, sufficient coloring power is obtained. However, if it exceeds 75% by mass, a new problem occurs in light resistance and the like.

Further, the monoazo colorant according to the present invention comprises
The surface can be treated by a conventionally known method, but the treatment with a rosin compound particularly prevents reaggregation of the colorant, improves the dispersibility of the colorant in the toner particles, and further improves the charging of the toner. Since the characteristics can be brought to a preferable state, the characteristics as described above are further improved.

Examples of the rosin compound which can be preferably treated with the monoazo colorant according to the present invention include natural rosin (tall oil rosin, gum rosin, rod rosin, etc.) or purified rosin (abietic acid, etc.) obtained by extraction from natural rosin, Modified rosin (hydrogenated rosin, disproportionated rosin,
Polymerized rosin), synthetic rosin (styrene acrylic rosin acid, etc.), and the above-mentioned alkali metal salts and ester compounds of rosin can be mentioned.

As a method for treating the colorant with the rosin compound as described above, (1) a dry mixing method in which the rosin compound and the colorant are dry-mixed and, if necessary, a heat treatment such as melt-kneading is carried out, (2 ) After adding an alkaline aqueous solution of rosin to the colorant synthesis solution at the time of producing the colorant, calcium,
Examples thereof include a wet treatment method in which a lake metal salt such as barium, strontium, or manganese is added to insolubilize the rosin to coat the surface of the colorant.

The rosin compound is contained in the colorant in an amount of 1 to 40% by mass, preferably 5 to 30% by mass, more preferably 10 to 30% by mass.
By containing 20% by mass, the above characteristics can be further improved.

Examples of the sulfur-containing polymer used in the present invention include polymer type compounds having a sulfonic acid group in the side chain. Particularly, a sulfonic acid group-containing (meth) acrylamide-based monomer having a copolymerization ratio of 2% by mass is used. % Or more, preferably 5% by mass or more, and has a glass transition temperature (Tg) of 40 to
90 ° C, weight average molecular weight 10,000 to 15,000
In the case of using the polymer type compound consisting of styrene and / or styrene (meth) acrylic acid copolymer which is, it is possible to enjoy preferable charging characteristics without affecting the thermal characteristics required for the toner particles, Further, the dispersibility of the colorant becomes sufficient.

As the sulfonic acid group-containing (meth) acrylamide-based monomer, those represented by the following general formula [3] are preferable, and specifically, 2-acrylamide-
Examples thereof include 2-methylpropanoic acid and 2-methacrylamido-2-methylpropanoic acid.

[0037]

[Chemical 7] [In the above general formula [3], R ₉ represents a hydrogen atom or a methyl group, R ₁₀ and R ₁₁ represent a hydrogen atom and C _{1 to} C ₁₀ respectively.
Represents an alkyl group, an alkenyl group, an aryl group, or an alkoxy group, and n represents an integer of 1 to 10. ]

When the sulfur-containing polymer according to the present invention is contained in the toner particles in an amount of 2 to 10 parts by mass with respect to 100 parts by mass of the binder resin, it becomes difficult for the toner particles to hold an opposite charge, and the charged state is changed. It can be made even better.

As a method for producing the toner according to the present invention, a binder resin, a colorant according to the present invention, a wax component, etc. are melt-kneaded by a pressure kneader or the like, and then the kneaded product is cooled to a desired toner particle size. Finely pulverized into fine particles, and the finely pulverized material is classified to adjust the particle size distribution to obtain a toner;
-10231, JP-A-59-53856 and JP-A-59-61842, a method for directly producing a toner by using a suspension polymerization method;
A method for producing a spherical toner by atomizing a melt-kneaded product in air using a disk or a multi-fluid nozzle described in JP-A-13945, etc .; and a known method such as an emulsion polymerization method typified by a soap-free polymerization method. It is possible to use
It is preferable to manufacture the toner by a suspension polymerization method.

The toner produced by the suspension polymerization method is a polymerizable monomer composition prepared by mixing a binder resin, a colorant according to the present invention, a polar resin, a wax component, a charge control resin and a polymerization initiator. To prepare particles of the polymerizable monomer composition by dispersing the polymerizable monomer composition in an aqueous medium, and removing the styrene monomer in the particles of the polymerizable monomer composition in the aqueous medium. It is produced by polymerization. Since the quinacridone colorant and the monoazo colorant used in the present invention have many hydrophilic functional groups, the toner is obtained by polymerizing granulated particles of the polymerizable monomer composition in an aqueous dispersion medium. When forming the particles, when the quinacridone colorant or the monoazo colorant is present alone, it migrates toward the interface between the polymerizable monomer composition which is a dispersoid and the aqueous medium, and as a result, the toner particle surface. Reaggregation occurs in the vicinity. Such a re-aggregate of the quinacridone colorant or the monoazo colorant adversely affects the charge amount and charge speed of the obtained toner particles as described above.

On the other hand, the quinacridone colorant and the monoazo colorant are appropriately adjusted within the range of the compounding amount satisfying the above-mentioned relation, and previously dispersed / mixed with a part of the polymerizable monomer composition. By later producing a toner by the suspension polymerization method, re-aggregation of the quinacridone colorant or the monoazo colorant alone is prevented, and the interaction between the quinacridone colorant and the monoazo colorant in the toner particles is prevented. It is possible to encapsulate the toner while maintaining the above, and it is possible to impart desired charging characteristics and color developability to the obtained toner.

In particular, when the toner of the present invention is produced by a suspension polymerization method or an emulsion polymerization method, not only can the problems caused by poor dispersion of the colorant be prevented, but the sulfur-containing polymer of the present invention can be used as described above. Since it has such a structure as described above, it is oriented near the surface of the toner particles and imparts excellent charging characteristics, and when the colorant as described above is used, the migration of the colorant near the surface of the toner particles is also prevented. Therefore, the charging characteristics are further improved. Further, in the suspension polymerization method, the charge control resin is uniformly oriented in the vicinity of the surface of the toner particles and attracts the dispersant in water to uniformly cover the surface of the particles with the dispersant, whereby the particles are integrated with each other. And shows excellent granulation stability and brings about a preferable effect in terms of production.

Examples of the binder resin for the toner used in the present invention include commonly used styrene- (meth) acrylic copolymers, polyester resins, epoxy resins, and styrene-butadiene copolymers. In the method of directly obtaining toner particles by a polymerization method, a monomer for forming them is used. Specifically, styrene; o
Styrene-based monomers such as-(m-, p-) methylstyrene and m- (p-) ethylstyrene; methyl (meth) acrylate, ethyl (meth) acrylate, propyl acrylate, (meth) acrylic acid Butyl, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, behenyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, dimethylaminoethyl (meth) acrylate, (meth ) A (meth) acrylic acid ester-based monomer such as diethylaminoethyl acrylate; an ene-based monomer such as butadiene, isoprene, cyclohexene, (meth) acrylonitrile or acrylic acid amide is preferably used. These may be used alone or generally in the publication Polymer Handbook, Second Edition II.
I-p139-192 (John Wiley & Son
The product has a theoretical glass transition temperature (Tg) of 40
It is used by appropriately mixing the monomers so that the temperature is up to 75 ° C. If the theoretical glass transition temperature is lower than 40 ° C, problems easily occur from the viewpoint of storage stability and durability stability of the toner,
On the other hand, when the temperature exceeds 75 ° C., the transparency of the OHP image is lowered in the case of forming a full-color image of the toner.

In the present invention, a polar resin such as a polyester resin or a polycarbonate resin may be used together with the above-mentioned binder resin.

For example, in the case of directly producing a toner by a suspension polymerization method or the like, when a polar resin is added during the polymerization reaction from the dispersion step to the polymerization step, the polymerizable monomer composition to be toner particles and the aqueous dispersion are added. Depending on the balance of polarities exhibited by the medium, it is possible to control the added polar resin so as to form a thin layer on the surface of the toner particles or to have a gradient from the surface of the toner particles toward the center. At this time, by using a polar resin that interacts with the coloring agent or the sulfur-containing polymer according to the present invention, the existing state of the coloring agent in the toner can be made into a desired form.

The amount of the polar resin added is 100% by weight of the binder resin 100.
It is preferable to use 1 to 25 parts by weight with respect to parts by weight,
It is more preferably 2 to 15 parts by mass. If it is less than 1 part by mass, the state of existence of the polar resin in the toner particles will be non-uniform, and if it exceeds 25 parts by mass, the thin layer of the polar resin formed on the surface of the toner particles will be thick, which is not preferable.

Specific examples of the polar resin used in the present invention include polyester resins, epoxy resins, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers and styrene-maleic acid copolymers. . In particular, a polyester resin having a peak molecular weight of 3,000 to 10,000 is preferable because it can improve the fluidity of toner particles, negative triboelectric charging characteristics, and transparency.

Specific examples of the wax component usable in the present invention include paraffin wax, microcrystalline wax, petroleum wax such as petrolactam and its derivatives, montan wax and its derivatives, and hydrocarbon wax by the Fischer-Tropsch method. And derivatives thereof, polyolefin waxes represented by polyethylene and derivatives thereof, carnauba wax, natural waxes such as candelilla wax and derivatives thereof, and the like. The derivatives include oxides, block copolymers with vinyl monomers, Graft modified products are also included. Further, alcohols such as higher aliphatic alcohols; aliphatics such as stearic acid and palmitic acid or compounds thereof; acid amides, esters, ketones, hydrogenated castor oil and its derivatives, vegetable waxes, animal waxes can be mentioned. These can be used alone or in combination.

The wax component used in the present invention has a main endothermic peak temperature (melting point) of 3 in the DSC curve measured according to "ASTM D3418-82".
A compound in the range of 0 to 120 ° C., and more preferably 40 to 90 ° C. is preferable because it can improve the fixability and transparency.

Further, in the present invention, it is preferable to use a crosslinking agent at the time of synthesizing the binder resin in order to increase the mechanical strength of the toner particles and control the molecular weight of the toner particles.

As the cross-linking agent used in the toner of the present invention, as a bifunctional cross-linking agent, divinylbenzene, bis (4-acryloxypolyethoxyphenyl) propane,
Ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate , Triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 200, # 400, # 600 diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester type diacrylate (MANDA Nippon Kayaku), And those in which the above diacrylate is replaced with dimethacrylate.

As the polyfunctional crosslinking agent, pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate and its methacrylate, 2,
Examples include 2-bis (4-methacryloxy, polyethoxyphenyl) propane, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate and triallyl trimellitate.

These crosslinking agents are preferably used in an amount of 0.05 to 10 parts by weight, more preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the monomer.

When the toner of the present invention is produced by the suspension polymerization method, the polymerization initiator is specifically 2,2'-
Azobis- (2,4-dimethylvaleronitrile), 2,
2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2 '
-Azobis-4-methoxy-2,4-dimethylvaleronitrile, azo-based or diazo-based polymerization initiators such as azobisisobutyronitrile; benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4- Peroxide type polymerization initiators such as dichlorobenzoyl peroxide and lauroyl peroxide are used. The amount of these polymerization initiators used varies depending on the intended degree of polymerization, but is generally 5 to 20 parts by mass with respect to 100 parts by mass of the polymerizable vinyl-based monomer. Although the type of the polymerization initiator varies slightly depending on the polymerization method, it may be used alone or in combination with reference to the 10 hour half-life temperature.

When the toner of the present invention is produced by the suspension polymerization method, as the dispersant used when preparing the aqueous dispersion medium, known inorganic and organic dispersants can be used. Specifically, as the inorganic dispersant, for example,
Tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, magnesium carbonate, calcium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina Is mentioned. Further, as the organic dispersant, for example,
Polyvinyl alcohol, gelatin, methyl cellulose,
Methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, and starch can be used.

It is also possible to use commercially available nonionic, anionic or cationic surfactants. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, and calcium oleate can be used.

When the toner of the present invention is produced by the suspension polymerization method, the dispersant used when preparing the aqueous dispersion medium is preferably an inorganic sparingly water-soluble dispersant, and moreover, a sparingly water-soluble dispersible acid. It is preferable to use an inorganic dispersant. Further, in the present invention, when a water-based dispersion medium is prepared using a poorly water-soluble inorganic dispersant, these dispersants are used in an amount of 0.2 to 2. 0
It is preferable to use it in such a proportion that it becomes part by mass. Further, in the present invention, it is preferable to prepare an aqueous dispersion medium using 300 to 3,000 parts by mass of water with respect to 100 parts by mass of the polymerizable monomer composition.

In the present invention, when an aqueous dispersion medium in which the poorly water-soluble inorganic dispersant as described above is dispersed is prepared, a commercially available dispersant may be used as it is. In order to obtain the dispersant particles having the above, the poorly water-soluble inorganic dispersant as described above may be prepared in a liquid medium such as water under high speed stirring. For example, when using tricalcium phosphate as a dispersant,
A preferable dispersant can be obtained by mixing an aqueous sodium phosphate solution and an aqueous calcium chloride solution under high-speed stirring to form fine particles of tricalcium phosphate.

[0059]

EXAMPLES The present invention will be described below with reference to specific examples, but the present invention is not limited thereto.

Specific examples of the sulfur-containing polymer used in the examples are shown in Table 1.

[0061]

[Table 1]

(Toner Production Example 1) 700 parts by mass of ion-exchanged water and 0.1 mol / liter were placed in a 2-liter four-necked flask equipped with a high-speed stirring apparatus TK type homomixer (made by Tokushu Kika Kogyo Co., Ltd.). -na ₃ PO ₄ aqueous solution 800 parts by weight were charged, 12000 rpm rotational speed of the high-speed stirrer
And was heated to 65 ° C. 1.0 mol here
/ L-CaCl ₂ aqueous solution (70 parts by mass) was added to prepare an aqueous dispersion medium containing a minute sparingly water-soluble dispersion stabilizer Ca ₃ (PO ₄ ) ₂ .

On the other hand, 4 parts by mass of quinacridone colorant (CI Pigment Red 122) 1 part by mass of quinacridone colorant (CI Pigment Violet 19) 3 parts by mass of monoazo colorant [C. I. Pigment Red 150 2.9 parts by mass Calcium salt of rosin compound (calcium abietic acid) 0.1 parts by mass] -Styrene monomer 47 parts by mass-Sulfur-containing polymer (R-1) 3 parts by mass-Polyester resin ( Peak molecular weight = 7000) A mixture of 5 parts by mass was dispersed for 3 hours using an attritor (manufactured by Mitsui Kinzoku Co., Ltd.) to prepare a pigment dispersion composition.

In a separate container, 30 parts by mass of styrene monomer, 23 parts by mass of 2-ethylhexyl acrylate monomer, 0.3 parts by mass of divinylbenzene monomer, and ester wax (melting point = 60 ° C.) 10 63 parts by mass of the pigment dispersion composition was added to a mixture of parts by mass, and the mixture was dispersed and dissolved while heating at 65 ° C.
2'-azobis (2,4-dimethylvaleronitrile) 5
By mass part, a polymerizable vinyl-based monomer composition as a dispersoid was prepared.

Next, the polymerizable monomer is added to the aqueous dispersion medium.
The body composition is added and the internal temperature is 65 ° C. ₂Fast in the atmosphere
While maintaining the rotation speed of the stirring device at 15000 rpm, 5
After stirring for a minute, the polymerizable monomer composition was granulated. That
After that, change the stirring device to one equipped with paddle stirring blades,
While maintaining the same temperature while stirring at 200 rpm,
The polymerization conversion rate of the nil-based monomer has reached almost 100%.
The polymerization reaction was completed by filtration.

After completion of the polymerization, the residual monomer was distilled off under heating and reduced pressure, and after cooling, dilute hydrochloric acid was added to dissolve the hardly water-soluble dispersant. After repeating water washing several times,
Using a cone-shaped ribbon dryer (manufactured by Okawara Seisakusho), a drying treatment was performed to obtain polymer particles (A).

100 parts by mass of the polymer particles (A) and silica fine powder treated with silicone oil (BET; 200 m ² /
g) Toner (A) was obtained by dry mixing 1.5 parts by mass with a Henschel mixer (manufactured by Mitsui Kinzoku Co., Ltd.). The circle-equivalent number average diameter of the toner (A) was 5.7 μm.

Production Examples 2 to 5 of Toner Production Example 1 of the toner described above except that the type and amount of the quinacridone colorant and the monoazo type colorant and the type and amount of the sulfur-containing polymer were changed. Similarly, after obtaining polymer particles (B) to (E), toners (B) to (E) were prepared.

(Production Example 6 of Toner) The following materials were mixed in advance, melt-kneaded with a twin-screw extruder, the cooled kneaded material was coarsely pulverized with a hammer mill, and the coarsely pulverized material was finely pulverized with a jet mill to obtain: The finely pulverized product thus obtained was classified to obtain classified powder (F). Binder resin 100 parts by mass [styrene-2-ethylhexyl acrylate-divinylbenzene copolymer peak molecular weight = 16,000, Mw / Mn = 5.0, Tg = 60 ° C.] Quinacridone colorant 8 parts by mass ( CI Pigment Red 122) Monoazo colorant 4 parts by mass (CI Pigment Red 146) Sulfur-containing polymer (R-2) 3 parts by mass Paraffin wax (melting point = 65 ° C.) 10 parts by mass

A comparative toner (F) was prepared in the same manner as in the toner production example 1 using the classified powder (F).

(Production Example 1 of Comparative Toner) A quinacridone-based coloring agent “C.I.
Pigment Red 122 "8 parts by mass except that Comparative Polymer Particles (a) were obtained in the same manner as in the above Production Example 1 of Toner, and then Comparative Toner (a) was prepared.

(Production Example 2 of Comparative Toner) A quinacridone colorant was not used, and a monoazo colorant “CI.
Pigment Red 184 ”and 5 parts by mass of Pigment Red 184, and 1 part by mass of“ R-3 ”as the sulfur-containing polymer. After obtaining, a comparative toner (b) was prepared.

(Production Example 3 of Comparative Toner) As a quinacridone colorant, “CI Pigment Red 2” was used.
02 "4 parts by mass, and as a monoazo colorant" C.
I. Pigment Red 146 ”and 4 parts by mass of the pigment, and except that the sulfur-containing polymer is changed to calixarene, the comparative polymer particles (c) are obtained in the same manner as in the production example 1 of the toner, and then the comparative toner ( c) was prepared.

Preparation Example 4 of Comparative Toner Preparation Example of the above toner except that 5 parts by mass of "CI Pigment Red 57: 1" was used as a colorant and the sulfur-containing polymer was changed to calixarene. After obtaining a classified product (d) in the same manner as in 6, a comparative toner (d) was prepared.

(Production Example 5 of Comparative Toner) As a quinacridone colorant, “CI Pigment Red 1” was used.
9 "2 parts by mass, and as a monoazo colorant" C.I.
Pigment Red 184 ”in an amount of 7 parts by mass and the sulfur-containing polymer is changed to 2 parts by mass of calixarene in the same manner as in the production example 6 of the toner.
After obtaining, a comparative toner (e) was prepared.

Table 2 shows the main prescription contents of the above-mentioned toner production examples and comparative toner production examples.

(Production Example 7 of Toner) As a colorant, "C.
I. Pigment Blue 15: 3 "5 parts by mass except that the polymer particles were obtained in the same manner as in the above toner production example 1 to prepare a cyan toner.

(Production Example 8 of Toner) As a colorant, “C.
I. Pigment Yellow 93 "7 parts by mass, except that polymer particles were obtained in the same manner as in the above toner production example 1 and then a yellow toner was prepared.

[Example 1] As an image forming apparatus, a laser beam printer (Canon: LBP-2160)
Was modified and used. The toner (A) obtained in the toner manufacturing example 1 is charged into this process cartridge, plain paper (75 g / m ² ) for a copying machine is used as a transfer material, and a character image with a printing area ratio of 4% in a monochrome mode. After printing out 5,000 sheets at a printout speed of 28 sheets (A4 size) / minute, the printout image was evaluated, and the image density and image fog suppression were good, and both were equivalent to the initial stage of printing. Met.

Also, 0.1 mg / cm ² to 1.0 mg
When several solid images with different toner amounts on the transfer paper were created in the range of / cm ² and the relationship between the toner amount on the transfer paper and the image density was evaluated, even if the toner amount on the transfer paper was relatively small, it was sufficient. Images with various image densities were obtained, and the high coloring power was confirmed.

The amount of toner on the transfer paper is 0.6 mg /
When a solid image of about cm ² was formed and the image light resistance was evaluated, excellent light resistance was shown.

Further, in addition to the magenta toner (A), the cyan toner obtained in Toner Production Example 7 and the yellow toner obtained in Toner Production Example 8 were used in the same manner as above, and plain paper for a copying machine was used. When a full color image was printed out at (75 g / m ² ), it was good even in the superposition of secondary colors or more, and an image with excellent color reproducibility was obtained. In addition, OHP sheet "CG3700" (made by 3M)
When an OHP projected image was printed out on the above and evaluated, it was excellent in transparency and good in superimposing secondary colors or more, and a projected image excellent in a wide color space was obtained.

The results of these evaluations are summarized in Table 3.

The evaluation method and its evaluation criteria are as follows, and Examples 2 to 6 and Comparative Examples 1 to 5 described later also follow these.

(Evaluation Method) (1) Image Density 5 mm on a side of ordinary paper for regular copying machines (75 g / m ² ).
Print out the solid image of the square of "X-Rit
"e504" (manufactured by X-Rite) was used to measure the relative density of the white background portion having a document density of 0.00 with respect to the printout image. A: 1.40 or more B: 1.30 or more, less than 1.40 C: 1.20 or more, less than 1.30 D: less than 1.20

(2) Image Strength A transfer residual toner on the photoconductor at the time of forming a solid white image is taped off with a Mylar tape and peeled off, and the reflection density of the toner adhered on paper is "X-Rite 50".
4 ". Evaluation was performed using the numerical value obtained by subtracting the reflection density when the Mylar tape was directly attached to the paper from the obtained reflection density. The smaller the value, the more the image fogging is suppressed. A: less than 0.03 B: 0.03 or more, less than 0.07 C: 0.07 or more, less than 0.15 D: 0.15 or more

(3) Several kinds of solid images having different toner amounts were prepared on the transfer paper within the range of the coloring power of 0.1 mg / cm ² to 1.0 mg / cm ² , and the image densities of the solid images were set to "X-Rite 504". After measuring using and determining the relationship between the toner amount on the transfer paper and the image density,
In particular, the tinting strength was relatively evaluated with the image density corresponding to the case where the amount of toner on the transfer paper was 0.5 mg / cm ² . A: Toner amount on transfer paper is 0.5 mg / cm ² , image density is 1.4 or more B: Toner amount on transfer paper is 0.5 mg / cm ² , image density is 1.35 or more, 1.40 Less than C: toner amount on transfer paper is 0.5 mg / cm ² , image density is 1.20 or more, less than 1.35 D: toner amount on transfer paper is 0.5 mg / cm ² , image density is 1. Less than 20

(4) Image resistance A solid image having a toner amount of about 0.6 mg / cm ² on a light-resistant transfer paper was prepared, and an ultraviolet auto fade meter "FAL-AU" (Suga Test Instruments Co., Ltd.) using a carbon arc lamp as a light source was used. Manufactured by K.K.) and evaluated according to “JIS K 7102”. The maximum irradiation time was set to 240 hours, the maintenance ratio of the image density before and after the light irradiation was calculated, and the light resistance of the image was evaluated. The closer the image density maintenance ratio (%) is to 100%, the better the image light resistance. A: 90% or more B: 80% or more, less than 90% C: 70% or more, less than 80% D: less than 70%

(5) Color reproducibility on plain paper A full-color image on a plain paper (75 g / m ² ) for a copying machine was visually evaluated, and "X-Rite SP68" (X
Measured by -Rite Co., Ltd.), the L ^* a ^* b ^* color system, which is standard in the International Commission on Illumination brightness L ^*, a representative of the degree of red or green ^*, b representing the degree of yellow or blue The volume of the color space solid determined by ^* was calculated. The larger the number, the wider the color space, and the smaller the number, the poorer the color reproducibility.

<Color space volume> A: 2.5 million or more B: 2 million or more and less than 2.5 million C: 1.5 million or more and less than 2 million D: less than 1.5 million

<Visual Evaluation> A: Magenta, excellent in color reproducibility of secondary colors (red and blue) B: Excellent in color reproducibility of magenta, but slightly inferior in secondary colors (red, blue) C: Magenta, secondary color (red, blue) color reproducibility is slightly inferior D: Magenta, secondary color (red, blue) color reproducibility is poor

(6) Full Color Projected Image Color Reproducibility and Transparency The full color image on the OHP sheet "CG3700" (manufactured by 3M) was made into a transparent image by OHP "9550" (manufactured by 3M) and projected on a white wall surface. The image was visually evaluated and measured with a spectral radiance meter "PR650" (manufactured by Photo Research Co.) to obtain L ^* a ^* b standardized by the International Commission on Illumination.
^* The volume of the color space solid determined by the lightness L ^{* of the} color system, a ^* indicating the degree of red or green, and b ^* indicating the degree of yellow or blue was determined. The larger the number, the wider the color space, and the smaller the number, the poorer the color reproducibility.

<Color space volume> A: 2.5 million or more B: 2 million or more and less than 2.5 million C: 1.5 million or more and less than 2 million D: less than 1.5 million

<Visual Evaluation> A: Vivid and excellent in transparency B: Good in transparency and excellent in color reproducibility of magenta,
Secondary colors (red, blue) are slightly inferior C: Transparency is slightly inferior, magenta, secondary colors (red, blue) are slightly inferior in color reproducibility D: Dull, magenta, secondary colors (red) , Blue) Both are poor in color reproducibility

[Examples 2 to 6 and Comparative Examples 1 to 5] The same as Example 1 except that Toners (B) to (F) and Comparative Toners (a) to (e) were used as toners. Evaluated. The results are shown in Table 3.

[0096]

[Table 2]

[0097]

[Table 3]

[0098]

As described above, according to the present invention,
In a dry toner containing at least a quinacridone colorant and a monoazo colorant, the toner is preferably selected / blended with the quinacridone colorant and the monoazo colorant in the toner, and further contains a sulfur-containing polymer. It is possible to improve the coloring property and dispersibility in the particles, to have a good coloring power and charging characteristics, to obtain an extremely vivid color excellent in light resistance, and to provide a toner excellent in OHP transparency. To be done.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Yasushi Katsuta             3-30-2 Shimomaruko, Ota-ku, Tokyo             Non non corporation F-term (reference) 2H005 AA01 AA06 AA21 AB06 CA04                       CA21 CA30 DA02 EA03 EA07

Claims (10)

[Claims] 1. A dry toner containing at least a binder resin, a quinacridone colorant, a monoazo colorant, and a sulfur-containing polymer, and the total content of the quinacridone colorant and the monoazo colorant in the toner. Is 1 to 20% by mass and the mass ratio of the contents is quinacridone colorant: monoazo colorant = 25: 75 to 75:25. 2. The dry toner according to claim 1, wherein the sulfur-containing polymer is a polymer having a sulfonic acid group. 3. The dry toner according to claim 1, wherein the quinacridone colorant is a pigment composition represented by the following structural formula [1]. [Chemical 1] [X ₁ and X ₂ represent a hydrogen atom or a substituent selected from an alkyl group, an alkoxy group and a halogen group. ] 4. The dry toner according to claim 1, wherein the monoazo colorant is a pigment composition represented by the following structural formula [2]. [Chemical 2] [R ₁ , R ₂ and R ₃ are each a hydrogen atom, an alkyl group,
A substituent selected from an alkoxy group, a halogen atom, a nitro group, anilide, and a sulfamoyl group is shown. R ₄ is selected from the following group, and the substituents R _{5 to} R ₈ in the following group are substituents selected from a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group and a nitro group. ] [Chemical 3] 5. The quinacridone colorant is C.I. I. Pi
gment Red122, C.I. I. Pigment
Red 202, or C.I. I. PigmentViol
5. The dry toner according to claim 1, wherein the dry toner is any one selected from the group of et 19 (each named according to the fourth version of Color Index). 6. The monoazo colorant is C.I. I. Pigm
ent Red 5, C.I. I. Pigment Red
31, C.I. I. Pigment Red 146, C.I.
I. Pigment Red 147, C.I. I. Pig
mentRed 150, C.I. I. Pigment R
ed 176, C.I. I. Pigment Red 18
4, C.I. I. Pigment Red 185, or C.I. I. Pigment Red 269 (each of which is based on the name described in Color Index Fourth Edition).
The dry toner according to any one of 1. 7. The dry toner according to claim 1, wherein the monoazo colorant is treated with a rosin compound. 8. The styrene and / or styrene having a glass transition temperature (Tg) of 40 to 90 ° C., wherein the sulfur-containing polymer contains a sulfonic acid group-containing (meth) acrylamide-based monomer in a copolymerization ratio of 2% by mass or more. The dry toner according to any one of claims 1 to 7, which is a high-molecular compound composed of a (meth) acrylic acid copolymer. 9. The method according to claim 1, which is obtained by a production method including a step of suspension-polymerizing a polymerizable monomer composition containing at least a binder resin and a colorant in an aqueous medium. The dry toner according to any one of 1. 10. The dry toner according to claim 1, wherein the dry toner is a magenta toner used for forming a magenta toner image when a full-color image is formed.