JPH11102086A - Developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a developer having a stable negative charging property by improving dispersibility and compatibility with a binder resin. SOLUTION: The average diameter of particles in a kneaded material containing predetermined 2: 1 type metal complex salt compound particles and a binder resin is 0.2 μm.
m or less, or in a developer containing a predetermined 2: 1 type metal complex compound, at least a low molecular weight wax is previously contained in the binder resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer used in an electrophotographic system or an electrostatic recording system.
In particular, the present invention relates to a developer used in a two-component developing method using a mixture of a toner and a carrier.

[0002]

2. Description of the Related Art In an electrophotographic apparatus or an electrostatic recording apparatus, in order to visualize an electrostatic latent image formed on an electrostatic holding member from a photoreceptor or a dielectric, a conventional method has been used.
A two-component developing method using a toner and a carrier and a one-component developing method using a toner also having a carrier function are widely used.

[0003] Such a toner is disclosed in JP-A-5-3134.
As disclosed in Japanese Patent Publication No. 04, generally, a thermoplastic resin, a coloring agent, and other additives such as wax are melt-mixed,
After being uniformly dispersed, the solidified product is pulverized and classified to produce colored fine particles having a desired particle size. Alternatively, a method of adding a polymerization initiator to a synthetic resin monomer, further mixing a colorant, and other additives such as a wax, and suspending the mixture in water to polymerize the mixture to produce colored fine particles having a desired particle size. Can be.

[0004] Since the electrostatic holder can be charged positively or negatively, a positive or negative electrostatic latent image is obtained by exposure under the original. Developing with a positively charged toner on a negative electrostatic latent image produces a positive-positive image consistent with the original. On the other hand, when development is performed on the positive electrostatic latent image with negatively charged toner, a positive-negative image is obtained. Thus, there are two types of electrophotographic toner, positively charged toner and negatively charged toner.

[0005] The coloring material mixed with the toner plays an important role as a charge control agent in terms of its electrostatic properties as well as coloring. In particular, many dyes and pigments conventionally used as colorants are positively charged, and even if they are negatively charged, their chargeability is weak. For this reason, when used for a conventional negatively charged toner, fogging and the like occur, and it has been difficult to obtain a clear image.

Examples of such negatively chargeable dyes include nigrosine dyes, azine dyes, metal complex salts of monoazo dyes, metal complex salts of salicylic acid, metal complex salts of naphthoic acid, metal complex salts of dicarboxylic acid, and copper phthalocyanine pigment. Can be Above all, metal complex salts of monoazo dyes are widely used for black toners because of their high ability to impart electric charge by triboelectric charging.

For example, Japanese Patent Publication No. 41-6397, Japanese Patent Publication No. 41-12915, and Japanese Patent Publication No. 41-20
No. 153, JP-B-43-27596, JP-B-51-29827, JP-A-47-5637, JP-A-49-21151, and JP-A-49-27.
No. 229 discloses an example in which a negatively charged 2: 1 type metal complex dye is used for a toner.

However, these dyes not only have a low negative charge performance in essence, but also have poor compatibility with a binder resin and are not uniformly dispersed in toner particles, so that practical negative chargeability can be obtained at all. I couldn't.

On the other hand, in order to prevent an offset phenomenon in which the toner adheres to and transfers to the surface of the heat roller when the toner is fixed by the pressurizing heat roller and the toner is transferred again to the next transfer sheet, a low molecular weight wax is used in the developer. In many cases, a means for dispersing the resin into the material and imparting releasability is employed.
However, it is difficult to knead and disperse the low molecular weight wax in the toner, and often it is necessary to use a large amount of the wax,
There has been a problem that the wax in the toner particles is unevenly dispersed and dispersed, so that blocking tends to occur, and the charge amount of the toner is affected, so that it is not possible to maintain image clarity for a long time.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to improve dispersibility and compatibility with a binder resin, to have a stable negative charge property,
An object of the present invention is to provide a developer that does not cause image defects such as fog.

[0011]

According to the present invention, first, at least the following general formula (1):

Embedded image

Wherein X represents a --CONHPh group, Y represents a --SO ₂ C ₂ H ₅ group, M represents a cobalt atom, and A represents an alkali metal or ammonium ion. In a developer obtained by melting and kneading the metal complex salt compound particles and the binder resin, and pulverizing the obtained kneaded material, the average particle diameter of the particles in the kneaded material is 0.2.
Provided is a developer having a particle size of not more than μm.

The present invention secondly provides at least the following general formula (2)

Embedded image

(Where X represents a nitro group or a halogen atom, Y represents a hydrogen atom, a halogen atom, or a nitro group, M represents a cobalt atom, and A represents an alkali metal or ammonium ion). In the developer obtained by melting and kneading the metal complex salt compound particles and the binder resin, and pulverizing the obtained kneaded material, the average particle diameter of the particles in the kneaded material is 0.2 μm or less. Provide a developer.

[0015] Third, the present invention provides a binder resin containing 0.5 to 5 parts by weight of a low molecular weight wax based on the resin solid content, and a 2: 1 type metal represented by the above general formula (1). Provided is a developer obtained by pulverizing a kneaded product obtained by melt-kneading a complex salt compound.

Fourth, the present invention relates to a binder resin containing 0.5 to 5 parts by weight of a low molecular weight wax based on the resin solid content, and a 2: 1 type metal represented by the general formula (2). Provided is a developer obtained by pulverizing a kneaded product obtained by melt-kneading a complex salt compound.

Fifthly, the present invention relates to a 5: 1 part by weight of low molecular weight wax and 0.5 to 5 parts by weight of a 2: 1 type compound represented by the above general formula (1) based on the resin solid content. Provided is a developer comprising a binder resin containing a metal complex salt compound.

Sixth, the present invention relates to a 6: 1 type of 2: 1 type compound represented by the above general formula (2), wherein 0.5 to 5 parts by weight of a low molecular weight wax and 0.5 to 5 parts by weight of the resin solid content are previously determined. Provided is a developer comprising a binder resin containing a metal complex salt compound.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present inventors have paid attention to the charging characteristics of a coloring material used in a developer, and have a negative charging characteristic. In particular, the dispersibility and compatibility with a binder resin used are considered. By finding very good dyes and further improving their compatibility and dispersibility, a developer having better negative chargeability has been obtained. As a result, it is possible to obtain a developer having excellent charging characteristics, in which all the disadvantages of the conventionally used coloring materials are improved.

According to the first invention, at least the following general formula (1)

Embedded image

(Wherein, X represents a -CONHPh group, Y represents a -SO ₂ C ₂ H ₅ group, M represents a cobalt atom, and A represents an alkali metal or ammonium ion). In a developer obtained by melt-kneading the metal complex salt compound particles and the binder resin and pulverizing the obtained kneaded material, a developer characterized in that the average particle size in the kneaded material is 0.2 μm or less. can get.

According to the second invention, at least the following general formula (2)

Embedded image

Wherein X is a nitro group or a halogen atom, Y is a hydrogen atom, a halogen atom, or a nitro group, M is a cobalt atom, and A is an alkali metal or ammonium ion. Wherein the average particle size in the kneaded product is 0.2 μm or less in a developer obtained by melting and kneading the type metal complex salt compound particles and the binder resin, and pulverizing the obtained kneaded material. Is obtained.

The average particle size is preferably not more than 0.15 μm.

This developer provides a charge amount suitable for developing an electrostatic image by regulating the average particle diameter of particles contained in the melt-kneaded product of the developer material to 0.2 μm or less. The charge amount is kept constant and the charge amount distribution is kept uniform and constant even in the repetition of development in an environment where fluctuations in triboelectric charging greatly affect such as humidity and low temperature / low humidity. Therefore, when this developer is used, it has a uniform and constant density, and it is possible to obtain a clear image that is environmentally stable over a long period of time as compared with a conventional negatively charged developer. .

In the developer according to the first and second aspects of the invention, the dye of the above formula (1) or (2) is added to the synthetic resin in a weight ratio of 0.5 to 5% by weight, and the mixture is melt-kneaded. , Crush,
And a polymerization method such as suspension polymerization and emulsion polymerization. At this time, the average particle size of the compound is 0.2 μm or less, preferably 0.15 μm.
It is preferable to prepare so as to be m or less.

If the amount of the dye is less than 0.5% by weight, the effect of controlling the charge when the dye is added tends to be insufficient. If the amount is more than 5% by weight, the excess dye bleeds, The charging tends to increase or decrease, making it difficult to stabilize. Furthermore, kneading and dispersion become difficult, and the dye tends to aggregate, so that the average particle size of the compound tends not to be 0.2 μm or less.

According to the third aspect of the present invention, a binder resin containing 0.5 to 5 parts by weight of a low-molecular-weight wax in advance with respect to the resin solid content, and 2: 1 represented by the above general formula (1) are used. The present invention provides a developer obtained by pulverizing a kneaded product obtained by melt-kneading a type metal complex salt compound.

Further, according to the fourth invention, a binder resin containing 0.5 to 5 parts by weight of a low molecular weight wax in advance with respect to the resin solid content, and 2: 1 represented by the above general formula (2) The present invention provides a developer obtained by pulverizing a kneaded product obtained by melt-kneading a type metal complex salt compound.

Further, according to the fifth invention, 0.5 to 5 parts by weight of a low-molecular-weight wax and 0.5 to 5 parts by weight of the above-mentioned general formula (1) represented by the above general formula (1) based on the resin solids content:
A developer comprising a binder resin containing a type 1 metal complex salt compound is provided.

According to the sixth aspect of the present invention, 0.5 to 5 parts by weight of the low molecular weight wax and 0.5 to 5 parts by weight are
There is provided a developer containing a binder resin containing 2 parts by weight of a 2: 1 type metal complex compound represented by the above general formula (2).

In the third and fourth inventions, the low-molecular-weight wax is previously contained in the binder resin, and the 2: 1 type metal complex salt compound represented by the general formula (1) or (2) is melted. Although mixed at the time of kneading, in the fifth and sixth inventions, the 2: 1 type metal complex salt compound represented by the general formula (1) or the general formula (2) is previously contained in the binder resin.

Here, in order to incorporate the low molecular weight wax in the binder resin in advance, for example, the low molecular weight wax is added during the polymerization of the copolymer resin and polymerized together with the resin, or added to the polymerized resin solution. Obtained by removing the solvent. The same applies to the case where the 2: 1 type metal complex salt compound represented by the general formula (1) or the general formula (2) is contained in advance.

As the low molecular weight wax, gel permeation chromatography (G
Polyolefin having a weight-average molecular weight of about 500 to 30,000, particularly about 1,000 to 1,000.
A polyolefin of about 10,000 to 10,000 is preferable. Further, these polyolefins have a softening point of 100 to 180.
C, preferably 130 to 160 C is suitably used. Specific examples of such a polyolefin include polyethylene, polypropylene, polybutylene and the like.

The binder resin contains 0.1 to 5 parts by weight of a low-molecular weight wax in advance. If the amount is less than 0.1 part by weight, the anti-offset effect when added is sufficiently obtained. Absent. If the amount is more than 5 parts by weight, excess wax bleeds, blocking easily occurs, and image quality deteriorates.

In this developer, at least a dye represented by the general formula (1) or the general formula (2) is added together with a coloring agent in a weight ratio of 0.1 to 5 parts by weight with respect to the binder resin. Can be produced by the above-described melt-kneading, pulverizing and classifying methods.

If the amount is less than 0.1 part by weight, the effect of controlling the charge when added is not sufficiently obtained. If the amount is more than 5 parts by weight, excess dye bleeds and the charge tends to increase or decrease. Becomes unstable.

The above general formula (1) or the above general formula (2)
The dye consisting of the 2: 1 type metal complex compound represented by
Compared with known dyes, the compatibility with the binder resin is good, and therefore, it is uniformly dispersed in the toner fine particles,
Demonstrate good charging performance. Further, the dye used in the present invention has an extremely large negative charge of itself.

According to the third and fourth aspects of the present invention, the use of the binder resin containing the wax in advance makes it possible to uniformly disperse the wax in the resin without layer separation. It is possible to obtain a toner having excellent release performance and eliminating the offset phenomenon at the time of fixing. Further, necessary wax can be added and kneaded at the time of toner production, and more uniform dispersion can be achieved. Furthermore, a stable negative charging property can be obtained by mixing the above-mentioned dye.

According to the fifth and sixth aspects of the present invention, a binder containing in advance a low molecular weight wax and a dye consisting of a 2: 1 type metal complex compound represented by the general formula (1) or (2). By using a resin, the dye can be uniformly dispersed in the resin without agglomeration, and good negative charging performance is exhibited. In addition, the wax can be uniformly dispersed in the resin without layer separation, so that the toner can have optimal release performance and a developer free from offset phenomenon at the time of fixing can be obtained. Further, even if a necessary wax is further added and kneaded at the time of toner production, uniform dispersion can be achieved.

When the developer according to the third to sixth aspects of the present invention is used, an amount of charge suitable for developing an electrostatic image is provided by friction with a carrier or the like, and a triboelectric charge such as high-temperature high-humidity or low-temperature low humidity is provided. The charge amount is kept constant and the charge amount distribution is kept uniform and constant even in the repetition of development in an environment where the fluctuation greatly affects. Therefore, an image using this toner has a uniform and constant density, and it is possible to obtain a clear image that is environmentally stable over a long period of time as compared with a conventional negatively charged developer. Becomes In addition, since a binder resin having a uniform wax dispersion is used, the anti-offset property at high temperatures can be improved with a smaller amount of use than in the past, and even dispersion can be achieved even when additional necessary wax is added. Therefore, the uneven distribution of the wax in the toner particles is eliminated, the adverse effect on the triboelectric charging of the toner is also eliminated, and the above effect can be further improved.

In the first to sixth inventions, the following general formula (3) (MO) _x (Fe ₂ O ₃ ) _Y (3) (where M is Li, Mg, Mn, Fe (II), C
o, one or two or more metals selected from the group consisting of Ni, Cu, Zn, Cd, Sr, and Ba, and the molar ratio X / Y between X and Y is 1.0 or less. It is preferable to further include a carrier to be used.

By using these carriers,
The property of the developer being electrostatically negatively charged is further improved.

The carrier particles preferably used in the present invention are ferrite-based and have a Fe ₂ O ₃ content of at least 40 mol%.
Is preferable. (MO) _X is, for example, NiO, CuO, MgO, ZnO, MnCO ₃ , Ba
CO ₃ , SrCO ₃ , Li ₂ (CO ₃ ), CdO and the like can be mentioned.

The carrier particles of the present invention may contain SiO ₂ , CaCO ₃ , TiO ₂ , SnO ₂ ,
PbO, V ₂ O ₅ , Bi ₂ O ₃ , Al ₂ O _{3 and the} like can be used.

The surface of the carrier is preferably coated with a resin composition comprising a silicone resin.

As the silicone resin, a silicone resin having a low surface tension is preferable, and a resin whose substituent is a methyl group, a phenyl group or an ethyl group is preferable. Further, as the modified silicone resin, for example, alkyd modified,
Modified silicone resins such as epoxy-modified, acrylic-modified, polyester-modified, phenol-modified, melanin-modified, and urethane-modified can be used.

The silicone-coated carrier has sufficient durability and stable triboelectricity, so that a developer with little environmental dependency and a long service life can be obtained.

Formula (1) used in the developer of the present invention
The dye represented by, for example, the following structural formula (4)

Embedded image

A 2-aminophenol derivative represented by the formula:
The following structural formula (5)

Embedded image

A 2-aminomethoxy derivative represented by the following structural formula (6):

Embedded image

A monoazo dye obtained from the amine derivative represented by the formula and β-naphthol is treated with a cobalt-imparting agent by a known method.

A 2: 1 type metal complex dye represented by the above formula (1) is dispersed in aqueous alcohol, and a stoichiometric excess of hydrochloric acid or sulfuric acid is added to make the counter ion H +. Equation (7)

Embedded image

(Where X represents a -CONHPh group, Y represents a -SO ₂ C ₂ H ₅ group, and M represents a cobalt atom). At this time, it is desirable that the ratio of the compound whose counter ion is H + is 50% or more.

In this case, as the alcohol, lower alcohols such as methanol, ethanol, propanol and butanol can be used, and the range of the alcohol concentration is preferably 30 to 50%.

The dye represented by the general formula (2) is represented by the following structural formula (8)

Embedded image

(Wherein, X represents a nitro group or a halogen atom, Y represents a hydrogen atom, a halogen atom or a nitro group) or a 2-aminophenol derivative represented by the following structural formula (9)

Embedded image

(Wherein, X represents a nitro group or a halogen atom, Y represents a hydrogen atom, a halogen atom or a nitro group) or a 2-aminomethoxy derivative represented by the structural formula (10)

Embedded image

(Wherein, X represents a nitro group or a halogen atom, Y represents a hydrogen atom, a halogen atom or a nitro group) and a monoazo dye obtained from β-naphthol is known. It is obtained by treating with a cobalt imparting agent by the method.

The 2: 1 type metal complex dye represented by the general formula (2) is dispersed in aqueous alcohol, and a stoichiometric excess of hydrochloric acid or sulfuric acid is added to change the counter ion to H ⁺ . The following general formula (11)

Embedded image

(Where X is a nitro group or a halogen atom, Y is a hydrogen atom, a halogen atom or a nitro group,
M represents a cobalt atom). At this time, the ratio of the compound whose counter ion is H ⁺ is 5
Desirably, it is 0% or more.

In this case, lower alcohols such as methanol, ethanol, propanol and butanol can be used as the alcohol, and the range of the alcohol concentration is preferably 30 to 50%.

Further, other colorants,
Alternatively, carbon black or the like may be added.

Further, inorganic oxide fine particles can be further added to the developer of the present invention.

Examples of such inorganic oxide fine particles include silica fine particles such as silicon dioxide, aluminum silicate, sodium silicate, zinc silicate, and magnesium silicate, zinc oxide, titanium oxide, aluminum oxide, zirconium oxide, and titanium oxide. Strontium acid, barium titanate and the like. In addition, resin fine powder such as polymethyl methacrylate, polyvinylidene fluoride, and polytetrafluoroethylene may be used as a cleaning aid. These external additives may have been subjected to a surface treatment such as hydrophobicity.

Further, as other conventionally known charge control agents,
For example, the metal chelate of alkyl salicylic acid, chlorinated polyester, polyester having an excess acid group, chlorinated polyolefin, metal salt of fatty acid, fatty acid soap, etc. can be prepared by converting the above general formula (1), general formula (2) or general formula (3). Can be used in combination so as not to affect the charge control agent of the compound represented by

Further, as the binder resin used in the present invention, a copolymer of styrene and its substitute, an acrylic resin and a methacrylic resin which can be used as a binder resin for a developer can be used.

Examples of the copolymer of styrene and its substituted product include polystyrene homopolymer, hydrogenated styrene resin, styrene-isobutylene copolymer, styrene-butadiene copolymer, acrylonitrile-butadiene-styrene terpolymer. Polymer, acrylonitrile-styrene-acrylate terpolymer, styrene-
Acrylonitrile copolymer, acrylonitrile-acrylic rubber-styrene terpolymer, acrylonitrile-chlorinated polystyrene-styrene terpolymer, acrylonitrile-EVA-styrene terpolymer, styrene-p
-Chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene rubber, styrene-maleic acid ester copolymer, styrene-isobutylene copolymer, styrene-maleic anhydride copolymer, and the like.

As the acrylic resin, for example,
Polyacrylate, polymethyl methacrylate, polyethyl methacrylate, poly-n-butyl methacrylate, polyglycidyl methacrylate, polyfluorinated acrylate, styrene-methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-ethyl acrylate copolymer And the like.

In addition, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, phenol resin, urea resin, polyvinyl butyral, polyacrylic resin, rosin, modified rosin, terpene resin, fatty acid or Alicyclic hydrocarbon resins, aromatic petroleum resins, chlorinated paraffins, paraffin waxes and the like can be used alone or as a mixture.

Examples of the coloring agent usable in the present invention include carbon black and organic or inorganic pigments and dyes. Although there are no special restrictions, carbon black includes acetylene black, furnace black, thermal black, channel black, Ketjen black, and the like, and face dyes such as First Yellow G, Benzidine Yellow, Indofast Orange,
Irgazine Red, Carmine FB, Permanent Bordeaux FRR, Pigment Orange R, Lisor Red 2
G, lake C, rhodamine FB, rhodamine B lake, phthalocyanine blue, pigment blue, brilliant green B, phthalocyanine green, quinacridone and the like can be used alone or in combination.

A wax can be used for the toner particles used in the present invention. As such a wax, a paraffin having 8 or more carbon atoms, a polyolefin or the like is preferable. For example, low molecular weight polypropylene, low molecular weight polyethylene, liquid paraffin, acid amide, stearic acid wax, montan wax, sasol wax, caster wax, Chlorinated paraffins and the like are preferred. The wax may be mixed and dispersed in advance during the production of the binder resin.

The developer of the present invention can be applied to the following developing devices.

FIG. 1 is a diagram showing an example of a developing device to which the developer of the present invention can be applied.

In FIG. 1, an electrostatic charge image is formed on the photosensitive drum 1. A toner container 2 near the photosensitive drum 1 contains a toner and a carrier (developer) 3.
A multi-pole magnet roll 4 and a developing sleeve 5 mounted on the outer periphery of the multi-pole magnet roll 4 are provided on the photosensitive drum 1 side.
The carrier of the developer 3 adheres to the surface of the developing sleeve 5 by the magnetic force of the multi-pole magnet roller 4, and the toner particles adhere to the surface of the carrier to form a toner layer. still,
The toner / carrier concentration ratio of developer 3 was 6.0%.
In FIG. 1, the multipolar magnet roller is fixed, the developing sleeve is rotated counterclockwise, and the developer 3 is conveyed as needed.
The transport amount of the developer 3 is regulated by the regulating blade 6. At the same time, the photosensitive drum 1 is rotated clockwise, and a bias is applied from the power source 7 at a position where the developing sleeve 5 and the photosensitive drum 1 approach each other, so that the electrostatic attraction causes the developing sleeve 5 to move onto the photosensitive drum 1. The toner 3 adheres to the electrostatic image, and development is performed.

[0076]

The present invention will be described below in detail with reference to examples.

Example 1 The following structural formula (12)

Embedded image

10 parts of the dye particles represented by the following formula were dispersed in 75 parts of a 50% aqueous ethanol solution, and after stirring, 1.5 parts of 36% hydrochloric acid was added. The mixture was stirred for 5 hours, then poured into 100 parts of water and filtered. The dye cake is washed with 50 parts of water and dried, and the following structural formula (13)

Embedded image

9.5 parts of dye particles represented by the following formula were obtained.

Next, 7 parts of carbon black and 2 parts of the dye of the above formula (13) were added to 100 parts of the styrene-acrylic copolymer resin, mixed with a blender, and then heated with a screw extruder heated to 180 ° C. It was melt-kneaded.

The average particle size of the dye particles in the melt-kneaded product was observed with a transmission electron microscope to find that the average particle size was 0.15 μm.
Met.

After cooling this kneaded material on a cooling belt, it is roughly pulverized, further pulverized using a fine pulverizer using a jet stream, further classified using an air classifier, and then mixed with hydrophobic silica. 0.3 parts of the fine particles were mixed by a high-speed fluid type blender to obtain a negatively charged fine powder having a particle size of 5 to 15 μm.

6% by weight of the toner particles was mixed with 94% by weight of a carrier obtained by coating a silicone resin on a ferrite core having an average particle diameter of 43 to 100 μm to prepare an electrophotographic developer composition.

The ferrite core was obtained by pulverizing and mixing 14 mol% of CuO, 16 mol% of ZnO, and 70 mol% of Fe ₂ O ₃ in a wet ball mill for 10 hours, and dried.
It was kept at 50 ° C. for 4 hours. This is a wet ball mill 24
It was ground for 5 hours or less. The slurry was granulated, dried, and kept at 1140 ° C. for 6 hours, and then pulverized and classified to have an average particle size of 43 to 100 μm. The composition of this carrier was 14 mol% of CuO, 15 mol% of ZnO, Fe ₂ O ₃
At 71 mol%, X / Y was 0.45. The carrier was coated with 5% by weight of a methyl group-substituted silicone resin using a fluidized bed, and further coated with 19%.
Baking was performed at 0 ° C. for 3 hours to obtain a resin-coated carrier.

Commercial copying machine (ED-6550, manufactured by Toshiba)
At 100 ° C humidity 20%, 20 ° C humidity 50%, and 30 ° C humidity 85%, a 100,000 copy test was performed.
Under measurement of image density and charge amount. Table 1 shows the results.
As shown in Table 1, when the developer of the present invention was used, a clear image having a high density was obtained even in each environment. And a clear image could be maintained.

Example 2 The following structural formula (14)

Embedded image

The dye particles represented by the following formula (15) were treated in the same manner as in Example 1 to give the following structural formula (15)

Embedded image

The dye particles represented by the following formula were obtained.

Next, a melt-kneaded product was obtained in the same manner as in Example 1 except that the dye particles of the above formula (15) were used. still,
The average dispersed particle size of the dye particles in the melt-kneaded product was observed with a transmission electron microscope and found to be 0.20 μm. Using this kneaded material, negatively charged fine powder having a particle size of 5 to 15 μm was obtained in the same manner as in Example 1.

Next, 6% by weight of the above toner particles were mixed with 94% by weight of the same carrier as in Example 1 to prepare an electrophotographic developer composition.

A copy test was performed on the obtained developer in the same manner as in Example 1. Table 1 shows the results.
As shown in Table 1, a high-density clear image was obtained even in each environment, and even after a 100,000-sheet copy test, there was no change in the charge amount, and a high-density clear image could be maintained. did it.

Comparative Example 1 The dye represented by Structural Formula (12) was converted to the following Structural Formula (16)

Embedded image

Example 1 except that the dye was changed to
A melt-kneaded product was obtained in the same manner as described above. The average particle size of the dye in the melt-kneaded product was observed with a transmission electron microscope and found to be 0.25 μm.

Further, a negatively charged fine powder having a particle size of 5 to 15 μm was obtained using the obtained melt-kneaded material.

Using the fluidized bed, a styrene-methyl methacrylate resin having a monomer composition ratio of styrene and methyl methacrylate of 45:55 in a ferrite core similar to that of Example 1 was obtained. The resin was coated and baked in the same manner as in Example 1, and the obtained resin-coated carrier was mixed with 94% by weight of the carrier and 6% by weight of the toner particles to obtain a developer.

A copy test was performed in the same manner as in Example 1 using the obtained developer. Table 1 shows the results. As shown in Table 1, a clear image was obtained at a high density at the initial stage, but the charge amount was significantly changed by a continuous copying test, and a clear image at a high density could not be maintained.

[0097]

[Table 1]

Example 3 10 parts of the dye represented by the above structural formula (12) was dispersed in 75 parts of a 50% aqueous ethanol solution, stirred, 1.5 parts of 36% hydrochloric acid was added, and the mixture was stirred for 5 hours. Drained and filtered. The dye cake was washed with 50 parts of water and dried to obtain 9.5 parts of the dye represented by the above structural formula (13).

Next, 70 parts of styrene and 30 parts of n-butyl methacrylate were subjected to bulk polymerization at 100 ° C. in a nitrogen stream, and when the conversion reached 80%, xylol 50
Parts, 45 parts of styrene and 5 parts of n-butyl methacrylate were charged and uniformly stirred. Furthermore, xylol 15
0 parts, and the above-mentioned resin-monomer solution 150
, A mixture of 10 parts of azobisisobutyronitrile and 3 parts of a low-molecular-weight polyolefin wax was dropped by using a continuous dropping apparatus over 4 hours to carry out polymerization. 2.3 × molecular weight
A styrene- (meth) acrylic acid copolymer resin having 10 ⁴ and Tg of 58 ° C. was obtained.

Thus, carbon black 7 was added to 100 parts of the binder resin containing the low molecular weight wax in advance.
And 2 parts of the dye of the above formula (13) were added, mixed by a blender, and then melt-kneaded by a screw extruder heated to 180 ° C.

The obtained kneaded material was cooled on a cooling belt, coarsely pulverized, further pulverized using a fine pulverizer using a jet stream, and further classified using an air classifier. 0.3 parts of the silica particles were mixed with a high-speed fluidizing blender to obtain negatively charged fine powder having a particle size of 5 to 15 μm.

To 94 parts of the same carrier as in Example 1, 6 parts of the toner particles were mixed to prepare an electrophotographic developer composition.

A copying test was carried out on the obtained developer in the same manner as in Example 1, and the results are shown in Table 2.
As shown in Table 2, a clear image of high density was obtained even in each environment, and even after a 100,000-sheet copy test, there was no change in the charge amount, and a clear image of high density could be maintained. did it.

No generation of high-temperature offset was observed even at a fixing temperature of 220 ° C., and there was no toner blocking after leaving at 55 ° C. for 8 hours.

Example 4 The dye represented by the above formula (14) was treated in the same manner as in Example 1 to obtain the dye represented by the above formula (15). Further, in the binder resin, the timing of adding the low-molecular-weight polyolefin wax was changed immediately before the removal of the solvent, so that the weight-average molecular weight of the binder resin previously containing the low-molecular-weight wax was 2.
A styrene- (meth) acrylic acid copolymer resin having 2 × 10 ⁴ and Tg of 60 ° C. was obtained.

Next, a developer was obtained in the same manner as in Example 3 except that the obtained acrylic acid copolymer resin was used and the dye of the above formula (13) was changed to the dye of the formula (15). .

A copying test was performed on the obtained developer in the same manner as in Example 1, and the results are shown in Table 2.
As shown in Table 2, a clear image of high density was obtained even in each environment, and even after a 100,000-sheet copy test, there was no change in the charge amount, and a clear image of high density could be maintained. did it.

No generation of high-temperature offset was observed even at a fixing temperature of 220 ° C., and there was no toner blocking after standing at 55 ° C. for 8 hours.

Comparative Example 2 The dye represented by the structural formula (13) was changed to the dye represented by the formula (16), and a weight average molecular weight of 2.0 × 10 ⁴ , Tg58 not added with a low molecular weight wax in advance. ° C
Styrene- (meth) acrylic acid copolymer resin was used as a binder resin, and the same low molecular weight wax as in Example 1 was added at the time of kneading. A fine powder having a particle size of 5 to 15 μm to be charged was obtained.

Next, a developer was obtained using the obtained fine powder in the same manner as in Comparative Example 1.

A copying test was performed on the obtained developer in the same manner as in Example 1. Table 2 shows the obtained results. As shown in Table 2, a clear image was obtained at a high density at the initial stage, but the charge amount was significantly changed by a continuous copying test, and a clear image at a high density could not be maintained.

At a fixing temperature of 220 ° C., a high-temperature offset occurred, and toner blocking occurred after being left at 55 ° C. for 8 hours.

Example 5 A dye represented by the structural formula (13) and a low molecular weight wax were prepared in the same manner as in Example 3 except that 2 parts of the dye represented by the structural formula (13) and 3 parts of the low molecular weight wax were used. A styrene- (meth) acrylic acid copolymer resin having a weight average molecular weight of 2.3 × 10 ⁴ and a Tg of 62 ° C. contained in advance was obtained.

Using 100 parts of the obtained binder resin and 7 parts of carbon black, a developer was obtained in the same manner as in Example 3.

A copying test was carried out on the obtained developer in the same manner as in Example 1, and the results are shown in Table 2.
As shown in Table 2, a high-density clear image can be obtained in each environment, and even after a 100,000-sheet copy test, the charge amount does not change and a high-density clear image is maintained. Was completed.

No generation of high-temperature offset was observed even at a fixing temperature of 220 ° C., and there was no toner blocking after leaving at 55 ° C. for 8 hours.

Example 6 In a binder resin previously prepared containing a dye and a low-molecular-weight wax produced in the same manner as in Example 1, the timing of adding the dye and the low-molecular-weight wax was changed immediately before the desolvation, and 15) a weight average molecular weight of 2.2 × 1 previously containing the dye and low molecular weight wax
It was obtained (meth) acrylic acid copolymer resin - 0 ^4, Tg59 ℃ styrene.

Next, using 100 parts of the obtained resin and 7 parts of carbon black, a developer was obtained in the same manner as in Example 3.

A copying test was carried out on the obtained developer in the same manner as in Example 1, and the results are shown in Table 2.
As shown in Table 2, a clear image of high density was obtained even in each environment, and even after a 100,000-sheet copy test, there was no change in the charge amount, and a clear image of high density could be maintained. did it.

No generation of high-temperature offset was observed even at a fixing temperature of 220 ° C., and there was no toner blocking after leaving at 55 ° C. for 8 hours.

[0121]

[Table 2]

[0122]

According to the present invention, by improving the dispersibility and compatibility with the binder resin, it is possible to obtain a developer having stable negative chargeability and free from image defects such as fogging.

[Brief description of the drawings]

FIG. 1 is a diagram showing an example of a developing device for applying a method of the present invention.

Claims (9)

[Claims] At least the following general formula (1): (Where X is a —CONHPh group, Y is —SO ₂ C ₂
Represents an H ₅ group, M represents a cobalt atom, and A represents an alkali metal or ammonium ion).
In the developer obtained by melting and kneading the type metal complex salt compound particles and the binder resin, and pulverizing the obtained kneaded material, the average particle diameter of the particles in the kneaded material is 0.2 μm or less. Developer. 2. At least the following general formula (2): Wherein X is a nitro group or a halogen atom, Y is a hydrogen atom, a halogen atom, or a nitro group, M is a cobalt atom, and A is an alkali metal or ammonium ion. A developer obtained by melt-kneading compound particles and a binder resin and pulverizing the obtained kneaded material, wherein the average particle diameter of particles in the kneaded material is 0.2 μm or less. 3. The developer according to claim 1, wherein the average particle size is 0.15 μm or less. 4. A binder resin containing low-molecular-weight wax in an amount of 0.1 to 5 parts by weight based on the solid content of the resin, and the following general formula (1): (Where X is a —CONHPh group, Y is —SO ₂ C ₂
Represents an H ₅ group, M represents a cobalt atom, and A represents an alkali metal or ammonium ion).
A developer obtained by pulverizing a kneaded product obtained by melting and kneading a type metal complex compound. 5. A binder resin containing low-molecular-weight wax in an amount of 0.1 to 5 parts by weight based on the solid content of the resin, and the following general formula (2): Wherein X is a nitro group or a halogen atom, Y is a hydrogen atom, a halogen atom, or a nitro group, M is a cobalt atom, and A is an alkali metal or ammonium ion. A developer obtained by pulverizing a kneaded product obtained by melt-kneading a compound. 6. A low molecular weight wax of 0.1 to 5 parts by weight and 0.1 to 5 parts by weight of the following general formula (1): (Where X is a —CONHPh group, Y is —SO ₂ C ₂
Represents an H ₅ group, M represents a cobalt atom, and A represents an alkali metal or ammonium ion).
A developer containing a binder resin containing a metal complex salt compound. 7. A low molecular weight wax of 0.1 to 5 parts by weight and a general formula (2) of 0.1 to 5 parts by weight based on the resin solid content in advance. Wherein X is a nitro group or a halogen atom, Y is a hydrogen atom, a halogen atom, or a nitro group, M is a cobalt atom, and A is an alkali metal or ammonium ion. A developer containing a binder resin containing a compound. 8. The following general formula (3): (MO) _x (Fe ₂ O ₃ ) _Y (3) (where M is Li, Mg, Mn, Fe (II), C
o, represents one or more metals selected from the group consisting of Ni, Cu, Zn, Cd, Sr, and Ba, and the molar ratio X / Y between X and Y is 1.0 or less. The developer according to any one of claims 1 to 7, further comprising a carrier to be used. 9. The developer according to claim 8, wherein the carrier is coated with a silicone resin.