JP3256820B2 - Developer for developing electrostatic images - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic image for visualizing an electrostatic latent image in an image forming method such as electrophotography and electrostatic recording.

[0002]

2. Description of the Related Art Toner must have a positive or negative charge, depending on the polarity of the electrostatic latent image to be developed.

In order to cause the toner to retain electric charge, it is possible to use the frictional charging property of a resin which is a component of the toner. However, in this method, since the charging property of the toner is small, an image obtained by development is easily fogged. , Will be blurred. Accordingly, in order to impart a desired triboelectric charging property to the toner, a dye, a pigment for imparting the charging property, and a charge controlling agent have been added.

[0004] The charge control agents known in the art today include, as negative triboelectrification, metal complex salts of monoazo dyes, metal complex salts of salicylic acid, naphthoic acid, dicarboxylic acids, copper phthalocyanine pigments, and acid components. Resins and the like are known.

The toner containing an iron complex used in the present invention is disclosed in JP-B-58-41508 and JP-A-59-6.
4850, JP-A-62-178978, JP-A-2-306253, JP-A-3-113463
JP, JP-A-3-152555, JP-A-4-1
It is known in Japanese Patent Application Laid-Open No. 99061.

[0006] However, the iron complexes disclosed therein tend to have excessive charge, and it is difficult to control the charge amount to an appropriate value. In particular, when a wax or a magnetic fine powder is contained, the uniformity of charging tends to be impaired due to their charging inhibition effect. As a result, fogging occurs and fluctuations in image density increase. In addition, when these iron complexes are applied to a one-component developer (magnetic and non-magnetic), the non-uniformity of the charge is one of the causes of a ghost (a phenomenon in which a history of a previous image remains in a cycle of a developing sleeve or the like). Become.

On the other hand, the wax added to the toner is
In recent years, it has been improved in the direction of melting sharply. By melting sharply, the fixing property can be improved from a lower temperature while maintaining the blocking resistance.
However, such a wax has a low viscosity when kneaded with a resin, and it is difficult to obtain a uniform wax dispersion. Due to the influence, the carrier, the developing sleeve, the photosensitive drum and the like are easily contaminated.

In recent years, the molecular weight of the resin has been improved in order to improve the fixability and offset resistance of the toner. This maintains elasticity up to higher temperatures while allowing viscosity to come out at lower temperatures. However, toner using such a resin is difficult to be crushed,
Poor productivity. In addition, a resin having a low viscosity at a lower temperature tends to cause filming on the photosensitive drum. Filming is promoted by factors such as reduction in the diameter of the photosensitive drum, contact charging means in contact with the photosensitive drum, and a rotating body for transfer. Therefore, such a copying machine poses a serious problem.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a developing device for developing an electrostatic image which can obtain a high image density from the beginning, does not gradually increase the image density, and does not cause the density to be reduced for long-term durability. To provide an agent.

SUMMARY OF THE INVENTION An object of the present invention is to provide a developer for developing an electrostatic image in which a carrier, a developing sleeve, a photosensitive drum, and the like are hardly contaminated and the charge for long-term durability is stable.

SUMMARY OF THE INVENTION An object of the present invention is to provide a developer for developing an electrostatic image, which has both low-temperature fixing and anti-offset properties and has no adverse effects.

An object of the present invention is to provide a developer for developing an electrostatic charge image which can obtain a high image density even when left under high temperature and high humidity, and can obtain a stable image density even when continuously copied under low temperature and low humidity. Is to do.

An object of the present invention is to provide a developer for developing an electrostatic charge image capable of obtaining an image having a high image density, no fog, and no ghost.

[0014]

The above object is achieved by
This is achieved by the following configuration.

That is, the present invention relates to a developer for developing an electrostatic image comprising at least a toner and a resin-coated carrier, wherein the resin-coated carrier has a current value of 20 to 200.
μA, and the toner has an aromatic hydroxycarboxylic acid derivative, an aromatic diol derivative, or a complex compound of an aromatic dicarboxylic acid derivative and an iron atom, and an Mw of 500 to 500 μA.
The toner contains 10,000 waxes, the toner has a loss elastic modulus G ₁ ″ at 150 ° C. of 1 × 10 ⁶ dyn / cm ² or less, and the toner has a storage elastic modulus G ′ at 200 ° C. of 1/100 × G _1. The present invention relates to a developer for developing an electrostatic image, characterized by having a size of “〜9 / 10 × G ₁ ”.

In addition, the composition contains the above-mentioned complex compound, contains B weight% of an inorganic oxide having an average particle size of A nm, and has an electronegativity (xi) of 10 to 15 for metal ions in the inorganic oxide. The above A and B are achieved by the toner for developing an electrostatic image satisfying the following relational expression (I).

0.3 ≦ B / A × 10 ³ ≦ 100 (I)

The present invention is also achieved by an electrostatic image developing toner containing the complex compound and a magnetic fine powder having a variation coefficient of particle size of 30% or less.

The present invention will be described below in detail.

The iron complex used in the present invention is represented by the following general formula (II).

[0021]

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As the counter ion, a proton, an alkali metal ion, an alkaline earth metal ion, an ammonium ion, a pyridinium ion and a derivative thereof can be applied, but an ammonium ion, a proton, and a sodium ion are preferable in terms of performance and production.

Specific examples of the iron complex of the present invention are shown below.
These are exemplifications in consideration of ease of synthesis and the like, and do not limit the present invention in any way.

[0024]

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[0025]

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Among them, those having a t-butyl group at the 7-position of the naphthalene ring of Compound Example a-1 are particularly preferable in terms of charge-providing ability and charge stability.

In the present invention, a known charge control agent as described in the prior art can be used in combination.

The toner of the present invention has a Mw of 500 to 1000.
By containing a wax having a Mw / Mn of 0, preferably 10 or less, it is possible to lower the fixing start temperature while minimizing the adverse effect on toner blocking. More preferably, Mw / Mn is 5 or less and Mw is 700.
And Mw / Mn of 2 or less and Mw of 800 to 2000 are more preferable. Mw is less than 500,
If it is larger than 10,000, it is difficult to achieve both fixing and blocking.

However, when Mn is 500 to 1000
If Mw / Mn is 0 or less, preferably 10 or less, the viscosity becomes low during kneading, and it is difficult to obtain a uniform wax dispersion. Such a wax sharply lowers the viscosity during fixing, but this property is inconvenient when kneading. This is probably because the temperature of the resin at the time of kneading is close to the temperature at the time of fixing, so that the wax has the viscosity shown at the time of fixing. On the other hand, in the present invention, by containing the above-mentioned iron complex, a wax having good dispersibility can be obtained. It is considered that the mechanism is that the compatibility between the wax and the iron complex is good, and the wax mass once dispersed is hardly re-agglomerated.
In conjunction with the good wax dispersibility, the carrier and the developing sleeve are less likely to be contaminated by the toner composition. As a result, the stability of charging in durability is also improved. In addition, a good effect is achieved on fixing, offset, and blocking.

Examples of the wax used in the present invention include an alkylene polymer obtained by radical polymerization of alkylene under high pressure, an alkylene polymer polymerized by Ziegler catalyst under low pressure, and an alkylene polymer obtained by thermally decomposing a high molecular weight alkylene polymer. Hydrocarbon waxes such as synthetic hydrocarbons obtained by hydrogenating the distillation residue of hydrocarbons obtained by the Age method from a synthesis gas consisting of carbon monoxide and hydrogen can be used. Among these waxes, a wax obtained by extracting and fractionating a specific component is particularly suitable. Pressed sweating, solvent method, fractional crystallization using vacuum distillation, etc.
It is preferable to extract a low molecular weight component and further remove a low molecular weight component therefrom.

In addition, microcrystalline wax,
Carnauba wax, sasol wax, paraffin wax, aliphatic solid alcohol and the like can also be used.

The content of these waxes depends on the binder resin 10
It is effective to use 0.5 to 10 parts by weight with respect to 0 parts by weight.

In the present invention, the loss modulus G ₁ ″ at 150 ° C. is 1 × 10 ⁶ dyn / cm ² or less,
Storage elastic modulus G ′ is 1/100 × G ₁ ″ to 9/1
0 × G ₁ ″. Preferably, the loss elastic modulus G ₁ ″ at 150 ° C. is 5 × 10 ⁵ dyn / cm ² or less, and the storage elastic modulus G ′ at 200 ° C. is 7/100.
× G ₁ ″ to 8/10 × G ₁ ″, and more preferably,
The loss modulus G ₁ ″ at 150 ° C. is 3 × 10 ⁵ dyn /
cm ² or less, and the storage elastic modulus G ′ at 200 ° C. is preferably 1/100 × G ₁ ″ to 7/10 × G ₁ ″.

The loss elastic modulus G ₁ ″ at 150 ° C. is 1
If it is larger than × 10 ⁶ dyn / cm ² , the fixability will be poor.
For example, if the temperature of the fixing roller decreases after continuous paper passing, the toner adhesion to the paper tends to be insufficient. Also, 2
If the storage elastic modulus G ′ at 00 ° C. is less than 1/100 × G ₁ ″, the offset resistance is poor. For example, the fouling of the web of the fixing roller is likely to be severe. 'Is 9 / 10x
If it is larger than G ₁ ″, unevenness due to each toner tends to remain, and the toner tends to peel off.
Generally, in order to obtain the above viscoelastic properties, the molecular weight distribution of the resin is optimized. In order to lower the loss elastic modulus G ₁ ″ at 150 ° C., it is sufficient to include a relatively large number of components having a relatively small molecular weight. In addition, the storage elastic modulus G ′ at 200 ° C. is 1/100 × G ₁ ″ to 9/10. In order to adjust to × G ₁ ″, a resin having a molecular weight of hundreds of thousands or more may be contained, and the molecular weight and the content may be controlled.

However, if the storage elastic modulus G ′ at 200 ° C. is adjusted to the above range, the kneaded material becomes hard and becomes difficult to pulverize. On the other hand, in the present invention, by containing the above-mentioned iron complex, pulverizability can be improved and productivity can be improved. It is considered that this is because the iron complex particles are dispersed in the resin in an appropriate size, and the particles are apt to cause breakage. On the other hand, if the loss elastic modulus G ₁ ″ at 150 ° C. is set to 1 × 10 ⁶ dyn / cm ² or less, filming on the photosensitive drum is likely to occur and cohesiveness is increased. According to the present invention, the filming is improved by containing the above-mentioned iron complex.The filming is considered to be due to the fact that the charging characteristics of the iron complex improve the transferability and reduce the amount of toner remaining on the photosensitive drum. This is particularly effective when the transfer device is a transfer rotating body, and it is considered that the microscopic charge distribution caused by the dispersion state of the iron complex influences the cohesiveness of the toner.

In the developer containing the toner and the carrier of the present invention, the current value is adjusted to 20 to 200 μA by adjusting the degree of unevenness of the carrier surface and the amount of the resin to be coated. Preferably, 30 to 150 μA is good. Current value is 2
When a carrier having a high resistance of less than 0 μA is used, the toner is excessively charged during long-term continuous copying, and reverse fog and low image density are likely to occur. This is presumably because the iron complex has a high charge-imparting ability. In addition, a low-resistance carrier having a current value larger than 200 μA often has a resin coating insufficient portion. Therefore, when the toner is combined with a relatively low-viscosity toner as in the present invention, spent tends to occur. When the spent occurs, the iron complex is also transferred to the carrier together, and the charge-imparting ability of the carrier is greatly reduced.

As the resin for coating the carrier surface, styrene-acrylate copolymer, styrene-methacrylate copolymer, acrylate copolymer, methacrylate copolymer, silicone resin,
Fluorine-containing resin, polyamide resin, ionomer resin,
Polyphenylene sulfide resin or the like, or a mixture thereof can be used.

As the magnetic material of the carrier core, oxides such as ferrite, iron-rich ferrite, magnetite, and γ-iron oxide, metals such as iron, cobalt, and nickel, or alloys thereof can be used. The elements contained in these magnetic materials include iron, cobalt, nickel, aluminum, copper, lead, magnesium,
Tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium and the like.

In the present invention, when an inorganic oxide is contained, the electronegativity (xi) of the metal ion in the oxide is 10%.
To 15 are used. Since such an inorganic oxide is neutral in charge, it has a function of suppressing toner charge. On the other hand, the iron complex has a sufficient charge-imparting ability, but tends to have excessive charge. By combining these, an appropriate charge can be obtained. If the electronegativity of the metal ion is less than 10, the toner becomes too positive, and the toner becomes partially positive instead of "charge suppression". In addition, the electronegativity of the metal ion is 15
If it is larger than this, the film becomes too negative and cannot suppress charging. When the particle size of the inorganic oxide as described above is small, an equivalent charge suppressing effect can be obtained with a small amount, and when the particle size is large, a large amount is required. In the present invention, the compound is added so as to satisfy the following relational expression (I) to obtain an appropriate charge suppressing effect.

0.3 ≦ B / A × 10 ³ ≦ 100 (I)

If the value is smaller than 0.3, the effect of suppressing the charge becomes insufficient, and if it is larger than 100, the effect of suppressing the charge is too strong.
Preferably, 0.5 to 70 is better, and more preferably,
0.6-40 is good.

The electronegativity of the metal ion (xi) is the Pauling electronegativity with x _0, the valence of the metal ions Z
Can be obtained by the following equation.

Xi = (1 + 2 × Z) x ₀

The particle size (Anm) of the inorganic oxide indicates the particle size when added to the toner. In the measurement, the average value is obtained by observing the surface of the toner particles with an electron microscope.

Among the inorganic oxides having a metal ion electronegativity of 10 to 15, titanium oxide, alumina, strontium titanate, and cerium oxide have dispersibility in toner,
It is particularly preferable in terms of the effect on charging. The electronegativity of a composite oxide such as strontium titanate is as follows:
Determined by weighted average.

Among the above inorganic oxides, the particle diameter is 100 nm.
The following fine particles are preferably subjected to a hydrophobic treatment with a silane coupling agent, silicone oil, or the like.

In the present invention, when a magnetic material is contained, a magnetic fine powder having a particle size variation coefficient of 30% or less is used. More preferably, the coefficient of variation is 25% or less. As a result, the fluidity of the toner is improved,
The sharpness of the charge distribution and the like are improved. The reason for this is
It is considered as follows. When the magnetic material has a broad particle size, a magnetic fine powder having a large particle size is likely to be exposed on a part of the toner surface. In addition, since magnetic fine powder having a too small particle diameter has strong cohesiveness, there is a possibility that the same action may be obtained as one lump. On the other hand, by using a magnetic fine powder having a sharp particle size distribution with a variation coefficient of 30% or less,
The exposed state of the magnetic fine powder on the toner surface becomes uniform. As a result, even a toner having a relatively high charge amount as in the present invention has weak cohesiveness. This is probably because the toner surface is uniform, so that contact charging between toners is suppressed.

The average particle size of the magnetic fine powder is 0.05
To 0.5 μm, more preferably 0.1 to 0.5 μm.
3 μm is good. The amount contained in the magnetic toner is preferably 40 to 120 parts by weight based on 100 parts by weight of the magnetic component.

As the magnetic material used in the present invention, for example, oxides such as magnetite, γ-iron oxide, ferrite, iron-rich ferrite and the like, metals such as iron, cobalt and nickel or alloys thereof can be used. . The elements included in these magnetic materials include iron, cobalt, nickel, aluminum, copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth,
Cadmium, calcium, manganese, selenium, titanium,
Tungsten, vanadium and the like can be mentioned.

In the present invention, a moderate leak effect is obtained by containing 0.01 to 3% by weight of an aromatic hydroxycarboxylic acid and / or a salt thereof. Preferably,
0.02 to 2% by weight is good. In particular, since excessive charging in a low-temperature and low-humidity environment can be prevented, stable charging characteristics can be obtained in combination with an iron complex.

Specific examples of the aromatic hydroxycarboxylic acid and salts thereof of the present invention are shown below, but these are exemplifications in consideration of easiness of synthesis, etc., and do not limit the present invention in any way. .

[0052]

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The kind of the binder resin used in the present invention includes, for example, a homopolymer of styrene such as polystyrene, poly-p-chlorostyrene and polyvinyltoluene and a substituted product thereof; styrene-p-chlorostyrene copolymer. Copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylate copolymer, styrene-methacrylate copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene- Acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile- Styrene copolymers such as indene copolymers Coalescence; polyvinyl chloride, phenolic resin, natural modified phenolic resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin , Polyvinyl butyral, terpene resin, cumarone indene resin, petroleum resin and the like can be used.

A crosslinked styrene copolymer is also a preferred binder resin.

Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and the like.
Such as dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. A monocarboxylic acid having a heavy bond or a substituted product thereof;
For example, dicarboxylic acids having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate and the like, and substituted products thereof; vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate;
For example, ethylene-based olefins such as ethylene, propylene, butylene; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone;
Vinyl monomers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, etc .;

Here, as the crosslinking agent, a compound having two or more polymerizable double bonds is mainly used, for example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene, etc .; Ethylene glycol dimethacrylate,
Carboxylic acid esters having two double bonds such as 1,3-butanediol dimethacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone; and compounds having three or more vinyl groups; Are used alone or as a mixture.

When the binder resin is styrene-acrylic,
The molecular weight distribution of the toner is a molecular weight distribution of the THF-soluble component by GPC, and at least one peak exists in a region having a molecular weight of 3,000 to 50,000, and at least one peak exists in a region having a molecular weight of 100,000 or more. 5 components with a distribution of 100,000 or less
A binder resin having a content of 0 to 90% is preferable.

In the case where the binder resin is a polyester resin, at least one peak exists in the molecular weight range of 3,000 to 50,000 in the same molecular weight distribution of the toner, and the component having a molecular weight of 100,000 or less has a peak of 60 to 100. % Is preferable.

By adopting such a molecular weight distribution, the dispersion of the charge control agent is improved, and good fixing properties and anti-offset properties are obtained.

As the additives for imparting various properties used in the present invention, for example, the following are used.

1) Fluidity imparting agent: metal oxide (silica,
Alumina, titanium oxide, etc.), carbon black, carbon fluoride, etc. Those subjected to a hydrophobic treatment are more preferable.

2) Abrasives: metal oxides (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide, etc.), nitrides (silicon nitride, etc.), carbides (silicon carbide, etc.), metal salts (calcium sulfate, etc.) , Barium sulfate, calcium carbonate).

3) Lubricants: fluororesin powder (vinylidene fluoride, polytetrafluoroethylene, etc.), fatty acid metal salt (zinc stearate, calcium stearate, etc.).

4) Charge controllable particles: metal oxides (tin oxide, titanium oxide, zinc oxide, silica, alumina, etc.)
Carbon black and spherical resin fine particles (average particle size 0.05
３3 μm).

These additives are used in an amount of 0.05 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of the toner particles. These additives are
They may be used alone or in combination.

Among the above-mentioned additives, silica fine powder has a preferable effect on the present invention. Particularly preferably, those having a particle size of 5 to 50 μm and made hydrophobic with a silane coupling agent, silicone oil or the like are good.

The coloring agents used in the present invention include carbon black, lamp black, iron black, ultramarine blue, nigrosine dye, aniline blue, phthalocyanine blue, phthalocyanine green, Hansa Yellow G and rhodamine 6.
Conventionally known dyes and pigments such as G, chaco oil blue, chrome yellow, quinacridone, benzidine yellow, rose bengal, triarylmethane dyes, monoazo dyes and disazo dyes can be used alone or in combination.

In the present invention, the weight average particle size is 3 to 15 μm
Of toner can be used. In particular, 12 to 60% by number of toner particles having a particle size of 5 μm or less are contained, and the particle size is 8 μm or less.
It is more preferable from the viewpoint of developing characteristics that toner particles having a particle size of 1 to 27 μm are contained in an amount of 1 to 33% by number and toner particles having a particle size of 16 μm or more are contained in an amount of 2.0% by weight or less.

In producing the toner according to the present invention, the above-mentioned toner constituent materials are sufficiently mixed by a ball mill or other mixer, and then kneaded well using a hot kneader such as a hot roll kneader or an extruder. A method of obtaining the toner by mechanical pulverization and classification after cooling and solidifying is preferable. Alternatively, a method of dispersing the constituent materials in a binder resin solution and then spray-drying to obtain the toner; A polymerized toner manufacturing method in which a predetermined material is mixed with a monomer to be constituted to form an emulsified suspension and then polymerized to obtain a toner; or in a so-called microcapsule toner comprising a core material and a shell material, a core material is used. Alternatively, a method of including a predetermined material in the shell material or both of them can be applied. Further, if necessary, the desired additive is sufficiently mixed with a mixer such as a Henschel mixer to produce the toner according to the present invention.

Hereinafter, a method for measuring each characteristic value used in the present invention will be described.

(1) Measurement of molecular weight distribution of wax Measured by GPC under the following conditions.

Apparatus: GPC-150C (Waters) Column: GMH-HT 30 cm 2 columns (manufactured by Tosoh Corporation) Temperature: 135 ° C. Solvent: o-dichlorobenzene (0.1% ionol added) Flow rate: 1.0 ml / min Sample: 0.4 ml of about 0.15% sample is injected

Measurement is performed under the above conditions, and a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample is used for calculating the molecular weight of the sample. In addition, Mark-Hou
It is calculated by converting to polyethylene using a conversion formula derived from the wink viscosity formula.

(2) Dynamic Viscoelasticity Measurement A dynamic viscoelasticity measuring device such as RMS-800 manufactured by Rheometrics Co., Ltd. is used. Approximately 1 g of a sample is fixed between the plates on a parallel plate test fixture (heated at about 150 ° C. for several minutes), and a strain of 62.8 rad / sec reciprocating torsional vibration is applied from one side, and the stress for this strain is detected on the other side. . The distortion rate was automatic (up to 10%). In this state, the temperature was increased, and the temperature dependence of the viscoelasticity was measured. From these results, values at 150 ° C. and 200 ° C. were determined.

(3) Measurement of Current Value of Carrier An electrode is provided at a distance of 1 mm in opposition to a conductive sleeve having a built-in magnet roll and provided with a spike regulating blade. A magnetic brush of the carrier is formed between the electrodes,
Rotate while applying a DC voltage of 500 V between the sleeve and the counter electrode (110 rpm). A 1MΩ, 10KΩ resistor is placed in series between the DC power supply and the electrode, and a 10KΩ
Measure the voltage drop across the resistor. A current flowing through the circuit is obtained from this voltage, and the obtained current is used as a carrier current value.

(4) Measurement of Coefficient of Variation of Particle Size of Magnetic Fine Powder The fine magnetic powder is well dispersed so that the overlap between the magnetic fine powders is reduced as much as possible, and a transmission electron micrograph of 30,000 times is taken in several fields so as not to be biased. take. From this, 1,000 or more magnetic fine powders are randomly selected, and their horizontal Feret diameter is measured. The coefficient of variation is the ratio of the standard deviation to the average diameter expressed in%.

(5) Measurement of Particle Size Distribution of Toner A Coulter Multisizer II (manufactured by Coulter, Inc.) was used as a measuring device, and a 100 μm aperture was used as an aperture.
The volume distribution and the number distribution of the 40 μm particles were calculated. Then, the weight-based weight average diameter (D4) obtained from the volume distribution according to the present invention, the number-based ratio (5 μm or less, etc.) obtained from the number distribution, and the like were obtained.

[0078]

EXAMPLES The present invention will be described below in more detail with reference to Examples, which should not be construed as limiting the present invention.
All parts in the following formulations are parts by weight.

Example 1 Styrene / n-butyl methacrylate / 100 parts Monobutyl maleate copolymer Low molecular weight polypropylene wax 2 parts (Mn = 780, Mw = 1280) Carbon black 3 parts Compound example (a-1) (t- (Bu is in the 7th position) 3 parts Compound example (b-1) (t-Bu is in the 7th position) 0.1 part

After thoroughly mixing the above materials with a blender,
The mixture was kneaded with a twin-screw kneading extruder set at 130 ° C. After cooling the obtained kneaded material and coarsely pulverizing with a cutter mill,
Finely pulverize using a fine pulverizer using a jet stream, and divide the obtained fine powders simultaneously and strictly with a multi-segmentation classifier using the Coanda effect (Nippon Mining Co., Ltd. elbow jet classifier). After classification and removal, the weight average particle size is 8.8 μm.
Was obtained.

0.1 parts of titanium oxide fine powder (particle size: 20 nm) treated with n-butylmethoxysilane and silica fine powder (particle size: 15 nm) treated with hexamethyldisilazane
0.5 parts and 100 parts of the black fine powder were mixed with a Henschel mixer to obtain a toner. 150 ° C of this toner
Loss elastic modulus G ₁ "is, 1.8 × 10 ⁵ dyn / c
m ² and the storage modulus G ′ at 200 ° C. is 4 ×
It was 10 ⁴ dyn / cm ² .

Next, Fe: Cu: Z having an average particle size of 45 μm
A developer is prepared by mixing n ferrite with a carrier coated with a silicone resin. The current value of this carrier was 110 μA. The mixing ratio was 93 parts of the carrier and 7 parts of the toner.

When the above toner was subjected to a blocking test, there was no problem if the toner was left at 50 ° C. for 3 days. When a fixing test was performed, the fixing start temperature was 1
The temperature at 50 ° C. and the hot offset occurrence temperature were 210 ° C.

For the above toner and developer, using a modified machine of a commercially available electrophotographic copying machine NP-6550 (manufactured by Canon Inc.), 10,000 sheets in an environment of 23 ° C./10% RH, and then
A copy test (including overnight standing) of 20,000 sheets was performed in an environment of 0 ° C./80% RH. As a result, 23 ° C./10% RH
In the environment (1), the image density changed to a level of 1.40 ± 0.03, and a clear image without fog was obtained. Even in the subsequent environment of 30 ° C./80% RH, the image density is 1.30 ± 1.
The image was shifted to the level of 0.10, and an image without fog was obtained.

After copying 30,000 sheets, the surface of the carrier is
Upon observation, the level of spent was mild. Further, when the surface of the photosensitive drum was observed, no adhesion of foreign matter such as filming was observed.

[0086]

[0087]

[0088]

[0089]

[0090]

Comparative Example 1 A toner (weight average particle size: 9.0 μm) was prepared in the same manner as in Example 1 except that 3 parts of Compound Example (a-1) was changed to 4 parts of a compound represented by the following structural formula (III). And a developer. Since the pulverizability was poor as compared with Example 1, pulverization was performed by increasing the pulverization pressure.

[0092]

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For this toner, a copy test of a total of 30,000 sheets was performed in the same manner as in Example 1. As a result, 30
C./80% RH, left overnight at 15,000 sheets (25,000 sheets in total), and toner scattering occurred when copying was resumed. At this time, fog also deteriorated considerably.

After copying 30,000 sheets, the surface of the carrier is
Upon observation, the spent was conspicuous.

Example 2 In Example 1, compound example (a-1) was replaced with compound example (a
A toner (weight-average particle size: 8.7 μm) and a developer were obtained in the same manner except that the composition was changed to -3).

For this toner, a copy test of 30,000 sheets was performed in the same manner as in Example 1. As a result, 23
The concentration level was 1.40 ± 0.04 in an environment of 30 ° C./10% RH, but was 1.2 in an environment of 30 ° C./80% RH.
The fluctuation range was as large as 5 ± 0.15. This is because the concentration after standing overnight was lower than that in Example 1.

Example 3 A toner (weight average particle size: 8.7 μm) was prepared in the same manner as in Example 1 except that Compound Example (b-1) was not added.
And a developer.

For this toner, a copy test of a total of 30,000 sheets was performed in the same manner as in Example 1. As a result, 23
In an environment of ° C./10% RH, the density level changed to 1.40 ± 0.04, and a clear image without fog was obtained. However, the initial concentration was lower than in Example 1, and the concentration was 1.3.
It took 150 sheets to exceed 5. On the other hand, 30 ° C
In an environment of / 80% RH, the image density is 1.30 ± 0.0
7 and the concentration was more stable than in Example 1.

Example 4 In Example 1, a low molecular weight polypropylene wax 2 was used.
A toner (weight average particle size: 9.1 μm) and a developer were obtained in the same manner except that the parts were changed to 2 parts of a polypropylene wax having Mn = 510 and Mw = 1520.

When a blocking test was performed on this toner, when left at 50 ° C. for 3 days, agglomerates were generated at a level that could be broken by applying force. There was no problem at 45 ° C. for 3 days. When a fixing test was performed, the fixing start temperature was 150 ° C., and the hot offset occurrence temperature was 210 ° C.
And the same as Example 1.

For this toner, a copy test of a total of 30,000 sheets was performed in the same manner as in Example 1. As a result, a result equivalent to that of Example 1 was obtained, but the spent amount of the carrier was larger than that of Example 1.

Example 5 A carrier having a current value of 170 μA was obtained by reducing the amount of resin coated on the carrier as compared with Example 1. A developer was obtained in the same manner except that this carrier was used.

For this developer, a copy test of 30,000 sheets was performed in the same manner as in Example 1. As a result, a result equivalent to that of Example 1 was obtained, but the spent amount of the carrier was larger than that of Example 1.

Comparative Example 2 A carrier having a current value of 240 μA was obtained by reducing the amount of resin coated on the carrier as compared with Example 1. A developer was obtained in the same manner except that this carrier was used.

For this developer, a copy test of a total of 30,000 sheets was performed in the same manner as in Example 1. As a result, the density was reduced from the place where the number of sheets exceeded 20,000 sheets. In addition, the spent amount of the carrier was larger than that of Example 1.

Example 6 A toner and a developer were obtained in the same manner as in Example 1 except that 0.1 part of titanium oxide was not added and 0.5 part of silica was changed to 0.6 part.

For this toner, a copy test of a total of 30,000 sheets was performed in the same manner as in Example 1. As a result, 23
In an environment of ° C./10% RH, the density level was changed to 1.35 ± 0.04, and a clear image without fog was obtained. However, the initial concentration was lower than in Example 1, and the concentration was 1.3.
It took 200 sheets to go over 0. On the other hand, 30 ° C
In an environment of / 80% RH, the image density is 1.32 ± 0.1
The level remained at 0 and was stable.

[0108]

[0109]

[0110]

As described above, according to the present invention, a high image density can be obtained from the beginning, the image density does not gradually increase, and there is no long-term durability for developing an electrostatic image. A toner can be obtained.

Further, it is possible to obtain a toner for developing an electrostatic image which is less likely to contaminate the carrier, the developing sleeve, the photosensitive drum, etc., and has stable charge for a long period of time.

Furthermore, while achieving both low-temperature fixing and offset resistance, there is no adverse effect, and a high image density can be obtained even when left at high temperature and high humidity, and a stable image can be obtained even when continuous copying is performed at low temperature and low humidity. It is possible to obtain a toner for developing an electrostatic image capable of obtaining an image having a high density, a high image density, no fog, and a ghost-free image.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-3-152554 (JP, A) JP-A-3-219262 (JP, A) JP-A-5-100477 (JP, A) JP-A-4- 353866 (JP, A) JP-A-5-249735 (JP, A) JP-A-2-110576 (JP, A) JP-A-63-2073 (JP, A) JP-A-5-19529 (JP, A) JP-A-6-95499 (JP, A) JP-A-5-65361 (JP, A) JP-A-5-325901 (JP, A) JP-A-3-121464 (JP, A) JP-A-5-45924 (JP, A) JP-A-4-3076 (JP, A) JP-A-56-6247 (JP, A) JP-A-3-119363 (JP, A) JP-A-3-213879 (JP, A) ( 58) Field surveyed (Int.Cl. ⁷ , DB name) G03G 9/08

Claims (4)

(57) [Claims] At least a toner and a resin-coated carrier
In electrostatic image developer consisting of the resin coated carrier, the current value at 20~200μA
There, the toner is an aromatic hydroxycarboxylic acid derivative, an aromatic diol derivative or complex compounds of aromatic dicarboxylic acid derivatives and iron atoms, and Mw of using the wax of 500 to 10,000, at 0.99 ° C. of the toner, The loss elastic modulus G ₁ ″ is 1 × 10 ⁶ dyn / cm ² or less ;
Storage modulus G ′ at 200 ° C. is 1/100 ×
Developer for electrostatic image development, which is a _{G 1 "~9 / 10 × G} 1". 2. The electrostatic image developing device according to claim 1, wherein the complex compound has the following structural formula.
Developer . Embedded image Wherein the aromatic hydroxycarboxylic acid and / or electrostatic image developer according to claim 1 or 2, characterized in that the salt contains 0.01 to 3 wt%. 4. A toner comprising an aromatic hydroxycarboxylic acid
Complex compounds of derivatives and iron atoms and aromatic hydroxycars
2. The composition according to claim 1, further comprising a boronic acid derivative.
4. The developer for developing an electrostatic image according to any one of items 1 to 3 .