JP2831379B2 - Electrophotographic toner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a novel toner for developing an electrostatic image in electrophotography, electrostatic recording, and the like.

[Prior Art] Toner for developer uses a dye,
Addition of a charge control substance such as a pigment has been performed.
The charge control substance may be one that imparts a positive charge to the toner or one that imparts a negative charge. Examples of the substance that imparts a negative charge include JP-B-41-20153 and JP-B-44-6397.
And metal-containing dyes such as those described in JP-A-57-141452 and metal complexes of oxycarboxylic acid shown in JP-A-53-127726 and JP-A-59-79256. is there.

These compounds have sufficient performance as toner charge control, but are not satisfactory in terms of high image quality, high durability, and stability due to environmental fluctuations.

[Problems to be Solved by the Invention] Under such circumstances, the present invention provides: (1) a toner capable of sufficiently obtaining a charge amount of toner particles and having no variation among toner particles; (2) resolution and fine line reproduction. (3) Toner which gives a stable image even when used continuously for a long period of time, and (4) Toner which gives a stable image without being affected by the environment such as temperature and humidity. It is intended for.

[Means for Solving the Problems] The present inventors have conducted intensive studies to solve the above-described problems, and as a result, have found that it is effective to use a specific metal compound, and have reached the present invention.

That is, the present invention is an electrophotographic toner containing at least one compound represented by the following general formula (I) or (II).

General formula [Wherein R ₁ represents hydrogen, a hydroxyl group, an amino group, an alkylamino group, and R ₂ represents hydrogen, a hydroxyl group, a carboxyl group, a carboxylic acid ester group having 1 to 5 carbon atoms, (R _{5 is, H, CH 3, C 2} H 5, R 6 is _{H, CH 3, C 2 H} 5, C 2 H 4 O
H), (R ₇ is H, CH ₃ OH, OCH ₃ , Cl, NO ₂ ) and R ₃ is (R ₈ is _{H, CH3, OCH 3, Cl} , And M represents chromium, cobalt, or iron, and X represents hydrogen, sodium, potassium, or ammonium ion.

The compound represented by the above general formula (I) or (II) of the present invention can be obtained by coupling a naphthoquinonediazo derivative and a naphthol derivative according to a conventional method, synthesizing a monoazo compound, and treating with a metallizing agent by a conventional method. . The synthesis examples are described below.

Synthesis Example 1 2.88 parts of β-naphthol and 1 part of sodium hydroxide were added to water 10
A solution of 5.9 parts of 4-diethylaminosulfonaphthoquinonediazo and 50 parts of dimethylformamide was added dropwise at room temperature, and the resulting mixture was stirred for 3 hours. The precipitated powder was filtered, washed thoroughly with water, and dried to obtain the following structure. To obtain purple-black crystals.

Dissolve 6.6 parts of these crystals in 30 parts of dimethylformamide, add 1 part of sodium hydroxide and heat to 120 ° C.
Add 1.85 parts, stir at 110-120 ° C for 4 hours, cool to room temperature, add a mixture of 15 parts of concentrated hydrochloric acid and 50 parts of water, stir for 30 minutes, filter, wash with water, and dry to obtain 6.8 parts of blue. A black powder was obtained.

Synthesis Example 2 4.3 parts of naphthol AS was dissolved in 50 parts of dimethylformamide, and 5-anilidesulfonaphthoquinonediazo was added thereto.
A solution of 6.4 parts and 50 parts of dimethylformamide is added dropwise, followed by stirring for 3 hours to perform coupling. The reaction solution is poured into 500 parts of water, and the precipitated crystals are filtered, sufficiently washed with water and dried, and then dried. Was obtained.

5.6 parts of this powder was dissolved in 50 parts of dimethylformamide, and 0.4 part of sodium hydroxide and 1.7 parts of ferric chloride were added thereto.
After stirring at 0 to 120 ° C for 3 hours, the mixture was cooled to room temperature, 100 parts of water was added with stirring, and the precipitated product was filtered, washed with water, and dried.
8.3 parts of a dark brown powder were obtained.

Synthesis Example 3 2.88 parts of α-naphthol and 1 part of sodium hydroxide were added to water 10
A solution of 6.5 g of a reaction product of naphthoquinonediazo-5-sulfonyl chloride and a novolak resin and 50 parts of dimethylformamide was added dropwise to the solution dissolved in 0 parts, and the mixture was stirred at room temperature for 3 hours. Dissolve the washed azo dye in 100 parts of dimethylformamide, add 1 part of sodium hydroxide and 2.6 g of cobalt chloride, heat to 120 ° C., stir for 4 hours, cool to room temperature, add 100 ml of water, stir for 30 minutes, The precipitated crystals are filtered, washed with water, and dried to give a black-purple powder.
7.5 g were obtained.

The compound of the general formula (I) or (II) obtained by the method described above is blended into a toner mainly containing a binder resin and a colorant, or is added to a powder surface mainly containing the resin. By blending, the toner of the present invention can be obtained.

In addition, the toner of the present invention can use a wide variety of conventionally known binder resins, for example, styrene, styrenes such as parachlorostyrene, vinyl naphthalene such as vinyl chloride, vinyl bromide, vinyl fluoride, and the like.
Vinyl acetate, pinyl propionate, vinyl benzoate,
Vinyl esters such as vinyl acetate, for example, methyl acrylate, ethyl acrylate, n-butyl acrylate,
Esters of α-methylene aliphatic monocarboxylic acids such as isobutyl acrylate, dodecyl acrylate, n-octyl acrylate, 2-chloro-ethyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate and butyl methacrylate , Acrylonitrile, methacrylonitrile, acrylamide, for example, vinyl methyl ether, vinyl isobutyl ether, vinyl ethers such as vinyl ethyl ether, such as vinyl methyl ketone, vinyl ketones such as vinyl hexyl ketone,
For example, polymers of monomers such as N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole and N-vinylpyrrolidone;
Copolymers or mixtures thereof which are copolymerized by combining at least two or more species, or non-vinyl such as non-vinyl-based thermoplastic resins such as rosin-modified phenol-formalin resin, oil-modified epoxy resin, polyurethane resin, cellulose resin and polyether resin Base resin or a mixture thereof with the vinyl resin as described above.

In addition, there are the following products which are particularly limited to those for pressure fixing.

Polyolefin (low molecular weight polyethylene, low molecular weight polypropylene, polyethylene oxide, polyfluoroethylene, etc.), epoxy resin, polyester resin (acid value 10 or less), styrene-butadiene copolymer (monomer ratio 5 to 5)
30: 35-70), olefin copolymer (ethylene-acrylic acid copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid copolymer, ethylene-methacrylic acid ester copolymer, ethylene-vinyl chloride Copolymer, ethylene-vinyl acetate copolymer, ionomer resin), polyvinyl pyrrolidone, methyl vinyl ether
Maleic anhydride copolymer, maleic acid-modified phenolic resin, phenol-modified terpene resin.

Further, in addition to the resin, an optional coloring agent such as a pigment or a dye can be added to the toner of the present invention, if necessary.
These colorants are known ones, for example, carbon black, nigrosine dye, aniline blue, calco oil blue, chrome yellow, ultramarine blue,
Dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, lamp black, oil black,
Azo oil black, rose bengal and mixtures thereof.

The toner of the present invention may further contain a magnetic material and be used as a magnetic toner.

Magnetite (iron sesquioxide) is most preferable because it is desirable that the magnetic material contained in the magnetic toner of the present invention is chemically stable and that a fine particle having a particle size of 1 μm or less can be easily obtained. . Representative magnetic or magnetizable materials include metals such as cobalt, iron, nickel; aluminum, cobalt, copper, iron, lead, magnesium, nickel, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, Alloys of metals such as manganese, selenium, titanium, tungsten, vanadium and mixtures thereof; aluminum oxide, iron oxide,
Metal compounds including metal oxides such as copper oxide, nickel oxide, zinc oxide, titanium oxide and magnesium oxide; refractory nitrides such as vanadium nitride and chromium nitride; carbides such as tungsten carbide and silica carbide Ferrite and mixtures thereof. These ferromagnetic substances preferably have an average particle size of about 0.1 to 1 μm, and the amount contained in the toner is about 50 to 300 parts by weight, particularly preferably 100 parts by weight, based on 100 parts by weight of the resin component. 90 to 200 parts by weight.

To use the toner of the present invention as a one-component developer, the toner may be used alone. However, when used as a two-component developer such as a non-magnetic toner, the toner is mixed with a known carrier.
The toner of the present invention can be used together with a fluidizing agent if necessary. As the fluidizing agent, fine powders of hydrophobic silica, titanium oxide, and aluminum oxide are preferable. On the other hand, 0.1 to 1 part by weight is preferable.

To prepare the electrostatic image developing toner according to the present invention,
After thoroughly mixing the compound represented by the general formula [I] or [II] with the above-mentioned resin and colorant, if necessary, a magnetic material, additives and the like by a ball mill or other mixer, a heating roll, a kneader, The colorant is dispersed or dissolved in the resin by melting and kneading using a heat kneading machine such as an extruder to dissolve or dissolve each other.After cooling and solidifying, the toner is pulverized and classified to obtain a toner having an average particle diameter of 5 to 20 μm. Obtainable.

Alternatively, a method in which a material is dispersed in a binder resin solution and then spray-dried, or a predetermined material is mixed with a monomer to constitute the binder resin to form an emulsified suspension and then polymerized to form a toner In addition to, for example, a method for producing a polymerization toner for obtaining a compound represented by the following general formula [I] or [II], The toner of the present invention can be obtained by mixing the compounds and applying them to the surface by mechanical impact.

The toners produced by these methods can be used for development for visualizing an electrostatic image in electrophotographic electrostatic recording or the like by a conventionally known means.

EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples.

Example 1 100 parts by weight of polystyrene 10 parts by weight of carbon black 2 parts by weight of the compound of Synthesis Example 1 A mixture consisting of 100 parts by weight of magnetite (0.1 μm) was heated and kneaded with a hot roll, cooled, pulverized, and classified to obtain a volume average particle size. 12μ, electrical resistance 3 × 10 ¹² Ωcm
Was obtained.

Next, the electrostatic latent image formed on the selenium photoreceptor by a normal electrophotographic method is developed by a developing device, and is transferred and heat-fixed to plain paper while applying a corona discharge. Obtained.

Example 2 A mixture composed of 100 parts by weight of a polyester resin, 10 parts by weight of carbon black, and 2 parts by weight of the compound of Synthesis Example 2 was heated and kneaded with a hot roll to obtain a nonmagnetic toner having a volume average particle diameter of 11 μm.

3 parts by weight of this toner was mixed with 100 parts by weight of the iron powder carrier to obtain a developer.

This developer was placed in a magnetic brush developing device to develop an electrostatic latent image formed on a selenium photosensitive member by a usual electrophotographic method. After repeating this process in a 100,000-sheet continuous test, a clear copy image was maintained.

Example 3 A mixture composed of 100 parts by weight of a copolymer of styrene-n-butyl methacrylate (copolymerization ratio 7: 3) and 10 parts by weight of carbon black was heated and kneaded with a hot roll to obtain particles having a volume average particle diameter of 10 μm. .

To the powder particles, 2 parts by weight of the compound of Synthesis Example 3 was added and mixed so as to be uniform.

This mixture is used as a hybridizer (Nara Machinery Co., Ltd.)
Then, the mixture was treated at 8,000 rpm for 5 minutes, and the compound of Synthesis Example 3 was injected into the surface of the mixed particles of carbon and resin and held to obtain a non-magnetic toner. 3 parts by weight of this toner was mixed with 100 parts by weight of the iron powder carrier to obtain a developer.

Copying was performed using the same developer as in Example 2 and a clear image was obtained.

[Effects of the Invention] As described above, in the toner of the present invention, the amount of triboelectric charge between toner particles is uniform, and control of the amount of charge is easy. Further, it is extremely stable without being deteriorated during use, so that problems such as development fog and toner scattering are improved. Furthermore, it has excellent resolution and fine line reproducibility.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G03G 9/097 CA (STN)

Claims (1)

(57) [Claims] 1. An electrophotographic toner containing at least one compound represented by the following general formula (I) or (II). General formula [Wherein R ₁ represents hydrogen, a hydroxyl group, an amino group, an alkylamino group, and R ₂ represents hydrogen, a hydroxyl group, a carboxyl group, a carboxylic acid ester group having 1 to 5 carbon atoms, (R _{5 is, H, CH 3, C 2} H 5, R 6 is _{H, CH 3, C 2 H} 5, C 2 H 4 O
H), (R ₇ is H, CH ₃ OH, OCH ₃ , Cl, NO ₂ ), and R ₃ is (R ₈ is H, CH ₃ , OCH ₃ , Cl, And M represents chromium, cobalt, or iron, and X represents hydrogen, sodium, potassium, or ammonium ion.