JPH0689044A - Electrostatic charge image developing developer - Google Patents

Abstract

PURPOSE:To provide an electrostatic charge image developing developer preventing melt sticking and filming, preventing shaving of a photosensitive body and being excellent in durability and developability. CONSTITUTION:In an electrostatic charge image developing developer containing at least a binding resin, a toner including wax and an inorg. fine powder, the electrostatic charge image developing developer contains (1) a wax of which penetration and density are <=4.0 and >=0.93 respectively and which is obtained by fractionating in respect of molecular wt., and (2) an inorg. fine powder A having <=5.0mum wt. average diameter and an inorg. fine powder B having >=30m<2>/g specific surface area.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer for developing an electrostatic charge image which is used in an image forming method such as an electrophotographic method, an electrostatic recording method and an electrostatic printing method using an organic photoreceptor.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic method, U.S. Pat. No. 2,297,691 and JP-B-42-23910 are known.
A large number of methods are known as described in Japanese Patent Publication No. 43-24748 and Japanese Patent Publication No. 43-24748. Generally, a photoconductive substance is used to form an electric latent image on a photoconductor by various means, and then the latent image is developed with a toner, and a toner image is formed on a transfer material such as paper if necessary. After transferring
The toner image is obtained by fixing with heat, pressure, heat and pressure, or solvent vapor.

In the final step of fixing the toner image on a sheet such as paper, the most common method at present is the pressure heating method.

However, in the above method, since the surface of the pressure-bonding heating member and the toner image are in contact with each other in a molten state under pressure, part of the toner image adheres to and transfers to the surface of the pressure-bonding heating member, and this is transferred to the next sheet to be fixed. Retransfer may cause a so-called offset phenomenon.

As a method of preventing such an offset phenomenon, generally, Japanese Patent Laid-Open No. 50-93647,
A method of adding a wax such as a homopolymer or a copolymer of a low molecular weight polyolefin having releasability to the toner as described in JP-B-57-52574 is generally used.

However, in the conventional method, the wax component often induces so-called toner fusion, which melts and fixes the toner on the photosensitive member.

In order to avoid this toner fusion, it is proposed in JP-A-48-47345 to add a friction reducing substance such as a lower fatty acid and an inorganic fine powder such as colloidal silica as a polishing substance. There is.

However, in this method, if the polishing substance is added to the extent that the accumulation of the friction-reducing substance having lubricity is prevented, a so-called filming phenomenon in which the polishing substance is fixed on the photosensitive member occurs, or the toner itself is removed. Combined with the polishing action, there is a problem that the photoconductor is excessively scraped and it is difficult to stably obtain a good image.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a developer for developing an electrostatic charge image, which solves the above problems.

That is, an object of the present invention is to provide a developer for developing an electrostatic charge image, which has good cleaning property and does not cause filming or fusion.

A further object of the present invention is to provide a developer for developing an electrostatic charge image which prevents abrasion of the photoconductor and gives a stable image.

A further object of the present invention is to provide a developer for developing an electrostatic charge image, which has excellent durability and developability and which can stably obtain a good image.

[0013]

According to the present invention, in a developer for developing an electrostatic charge image containing at least a binder resin, a toner containing a wax and an inorganic fine powder, the penetration of the wax is 4. A wax having a density of 0 or less, a density of 0.93 or more, and a molecular weight fractionated, wherein the inorganic fine powder is
The present invention relates to a developer for developing an electrostatic charge image, which contains an inorganic fine powder A having a weight average diameter of 5.0 μm or less and an inorganic fine powder B having a specific surface area of 30 m ² / g or more.

The present inventors have found that the use of the above wax can prevent the toner fusion on the photoreceptor.

The wax of the present invention is characterized in that it has a penetration of 4.0 or less and a density of 0.93 or more, and is fractionated by molecular weight. It imparts slipperiness to the toner and improves the cleaning property. It is possible to prevent fusion of the toner on the photoconductor and reduce abrasion of the photoconductor. Preferably, the penetration is 3.0 or less and the density is 0.94 or more. Further, the crystallinity is preferably 80% or more, more preferably 85% or more.

When the density is 0.93 or more, and preferably the crystallinity is 80% or more, the toner can be dispersed in a state that effectively imparts slipperiness to the toner. That is, it is considered that they are dispersed on the toner surface with an appropriate size. Further, if the penetration is more than 4.0, the density is less than 0.93, or the crystallinity is less than 80%, it is difficult to obtain the effect and fusion occurs on the photoconductor. It is not preferable because it becomes easier to do. Furthermore,
The softening point is preferably 130 ° C. or lower, and particularly preferably 120 ° C. or lower. If it exceeds 130 ° C, the offset resistance is affected.

The wax used in the present invention is a wax whose molecular weight has been fractionated. By performing the molecular weight fractionation, the width of the molecular weight distribution of the wax can be narrowed and unnecessary low molecular weight and high molecular weight components can be removed. As a result, the molecular weight-separated wax has the following characteristics.

First, the melting point range is narrowed. That is, the wax component having a melting point near the desired temperature is extracted, and the other low-melting point and high-melting point components are removed, and when the temperature is gradually raised, the wax becomes rapidly melted near the melting point. . As a result, it is possible to exert an effect on offset resistance and fixability without deteriorating the blocking resistance of the toner using the wax whose molecular weight has been fractionated.

Further, the wax having a molecular weight fraction is characterized in that it is harder than the wax which has not been fractionated. When the wax is hard, the toner becomes slippery due to the action of the wax that appears in the surface layer of the toner when the wax is used. That is, the toner is less likely to adhere to the photoconductor, is easily cleaned, and fusion can be prevented.
Further, since the toner is slippery, the polishing action of the toner is reduced, and the toner itself does not scrape the photoreceptor too much.

The wax used in the present invention is obtained from the following waxes. Paraffin wax and its derivatives, montan wax and its derivatives,
Microcrystalline wax and its derivatives, Fischer-Tropsch wax and its derivatives, polyolefin wax and its derivatives, and the like. The derivatives include oxides, block copolymers with vinyl monomers, and graft modified products.

In addition, alcohols, fatty acids, acid amides,
Esters, ketones, hydrogenated castor oil and its derivatives, vegetable wax, animal wax, mineral wax, petrolactam and the like can also be used.

Among them, the wax which is preferably used is a low molecular weight alkylene polymer obtained by radically polymerizing alkylene under high pressure or by Ziegler catalyst under low pressure,
From the distillation residue of the hydrocarbon obtained by the Arge process from a synthesis gas consisting of an alkylene polymer obtained by thermally decomposing a high-molecular-weight alkylene polymer, carbon monoxide, and hydrogen,
Alternatively, a wax obtained from a synthetic hydrocarbon obtained by hydrogenating these is used, and an antioxidant may be added.

From these waxes, a wax obtained by fractionating the wax according to its molecular weight by using a press sweating method, a solvent method, a vacuum distillation, a supercritical gas extraction method, fractional crystallization (for example, melted liquid crystal precipitation and crystal filtration) is obtained. Used in the present invention. Further, oxidation, block copolymerization, or graft modification may be performed after the fractionation. That is, those obtained by removing the low molecular weight components, those obtained by extracting the low molecular weight components, and those obtained by further removing the low molecular weight components by these methods, etc.

The most preferable wax as a matrix uses a metal oxide catalyst (often two or more kinds of multi-component wax),
Carbon number obtained by the reaction of carbon monoxide and hydrogen, such as the gintol method, the hydrocoal method (using a fluidized catalyst bed), or the arge method (using a fixed catalyst bed) where a large amount of waxy substances can be obtained Hydrocarbons up to several hundreds (particularly preferred as hydrogenated products) and hydrocarbons obtained by polymerizing alkylenes such as ethylene with a Ziegler catalyst are small-branch, small, long-chain saturated carbon It is hydrogen. In particular, a hydrocarbon wax synthesized by a method that does not depend on the polymerization of alkylene is preferable because of its structure and molecular weight distribution that facilitates separation. Moreover, the preferable range of the molecular weight distribution is such that the number average molecular weight (Mn) is 300 to 1200, preferably 350 to 1000, and the weight average molecular weight (Mw) is 5.
00-3600, preferably 550-3000, Mw /
Mn is 3 or less, preferably 2.5 or less, and particularly preferably 2.0 or less. By imparting such a molecular weight distribution, the wax can have desirable physical properties.

The wax used in the present invention is 140 ° C.
The melt viscosity in is preferably 200 cP or less, particularly preferably 50 cP or less. If it exceeds 200 cP, the offset resistance and fixing property of the developer are deteriorated.

The wax of the present invention has the following characteristics, and in the DSC curve measured by a differential scanning calorimeter, the onset temperature of the peak is 50 to 110 ° C., which is the endothermic peak at the time of temperature rise.
It is preferably within the range.

At the time of temperature rise, a change when heat is applied to the wax can be seen, and an endothermic peak due to wax transition and melting is observed. Peak onset temperature is 50-1
Within the range of 10 ° C., the developability, blocking resistance, and low temperature fixability can be satisfied. If the peak onset temperature is less than 50 ° C., the wax change temperature is too low, blocking resistance tends to be poor, or the toner may have poor developability at the time of temperature increase. If it exceeds 110 ° C., The change temperature of the wax is too high, and sufficient fixability cannot be obtained.

In the DSC measurement of the present invention, the heat exchange of the wax is measured and the behavior thereof is observed. Therefore, it is preferable to measure with a highly accurate internal heat input compensation type differential scanning calorimeter from the principle of measurement. For example, DSC-7 manufactured by Perkin Elmer can be used.

The measuring method is ASTM D3418-82.
Carry out according to. The DSC curve used in the present invention has a temperature rate of 10 ° C./m after the temperature has been raised and lowered once and the previous history is taken.
The DSC curve measured when the temperature is raised in is used.

The onset temperature of the endothermic peak refers to the temperature at the intersection of the tangent to the curve and the baseline at the point where the differential value of the DSC curve at the time of temperature rise reaches its maximum.

In the present invention, the molecular weight distribution of the hydrocarbon wax is determined by gel permeation chromatography (G
PC) under the following conditions.

(GPC measurement conditions) Device: GPC-150
C (Waters Co.) Column: GMH-HT 30 cm 2 series (manufactured by Tosoh Corp.) Temperature: 135 ° C. Solvent: o-dichlorobenzene (addition of 0.1% ionol) Flow rate: 1.0 ml / min Sample: 0.15% sample 0.4 ml injection Measured under the above conditions, a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample is used to calculate the molecular weight of the sample. Further, it is calculated by performing conversion corresponding to the wax such as polyethylene conversion (for example, hydrocarbon wax is converted to polyethylene) using a conversion formula derived from the Mark-Houwink viscosity formula.

The penetration of waxes in the present invention is J
It is a value measured according to IS K-2207. Specifically, it is a numerical value representing the penetration depth in units of 0.1 mm when a needle having a conical tip with a diameter of about 1 mm and an apex angle of 9 ° is penetrated with a constant load. The test conditions in the present invention are a sample temperature of 25 ° C., a load of 100 g, and a penetration time of 5 seconds.

The melt viscosity is a value measured by using a Brookfield viscometer, and the condition is a measurement temperature of 1
40 ° C., shear rate 1.32 rpm, sample 10 ml. The softening point is a value measured according to JIS K-2207.

The crystallinity is based on the X-ray diffraction method,
The diffraction pattern due to the crystal has a sharp peak, and the scattering due to the amorphous is a very broad halo. When crystalline and amorphous are mixed, the ratio of crystalline to the entire sample is called crystallinity. The total X-ray scattering intensity (intensity of coherent scattering excluding Compton scattering) is always constant regardless of the amount ratio of crystalline and amorphous. Therefore, the crystallinity χ (%) is obtained by the following equation.

Χ (%) = Ic / (Ic + Ia) × 100 Ic: Peak area of scattering intensity of crystalline portion of unknown sample Ia: Peak area of scattering intensity of amorphous portion of unknown sample Of these hydrocarbon waxes The content is 100% binder resin.
Used within 20 parts by weight with respect to parts by weight, 0.5-10
It is effective to use it in parts by weight, and it may be used in combination with other waxes.

Further, an inorganic fine powder is added to the toner having the wax of the present invention. The inorganic fine powder is the inorganic fine powder A having a weight average diameter of 5.0 μm or less and a specific surface area of 30 m ² /
The inorganic fine powder B is g or more.

In the present invention, the inorganic fine powder A has a function of scraping off the low electric resistance substance such as paper powder and the toner adhering to the surface of the photoreceptor. It also has the effect of assisting the charging of the developer. The inorganic fine powder A has a weight average particle diameter of 0.1 to 5.0 μm, preferably 0.1 to 5.0 μm, in terms of primary particles (particles separated into individual unit particles) or secondary particles (aggregated primary particles). 5 to 5.0 μm, more preferably 1.0 to
It is 5.0 μm. If the weight average diameter is larger than the above range, it is not developed and remains in the developing device, which accumulates and causes deterioration of image quality. If the weight average diameter is smaller than the above range, the polishing effect of the inorganic fine powder A is reduced, or cleaning failure occurs, which causes image deterioration.

The inorganic fine powder B has the effect of improving the fluidity of the developer and making the charge uniform. The inorganic fine powder B has a specific surface area of 30 m ² / g or more, preferably 35~500m ² /
g, more preferably 40 to 400 m ² / g. When the specific surface area is larger than the above range, it easily aggregates,
In addition, the toner is liable to be released from the toner and float easily, and filming is apt to occur. If the specific surface area is smaller than the above range, the fluidity of the developer tends to be poor.

The inorganic fine powders A and B are used as a mixture with toner particles.

By using the above-mentioned wax and the inorganic fine powder A and the inorganic fine powder B, which are the features of the present invention, in the developer, the following effects can be obtained. First, since the wax whose molecular weight has been separated is hard and slippery, the toner using it is also hard and slippery due to the effect of the wax existing on the toner surface. Therefore, the surface of the photoconductor is easily cleaned and is not easily fused. The inorganic fine powder B also reduces the cohesive force of the toner and prevents the toner from being fused to the photoreceptor. However, the inorganic fine powder B itself floating and liberated from the toner is difficult to be cleaned, and may be fixed on the photoconductor by pressing the cleaning member to cause a filming phenomenon. Therefore, the inorganic fine powder A functions to scrape off the adhered substance on the photoconductor and prevent the filming phenomenon.

That is, by using the specific wax of the present invention, due to the lubricity of the toner particles themselves, the fusion can be almost prevented, and the inorganic fine powder A having the polishing action and the inorganic fine powder B having the fluidizing action are obtained. By combining the above, it is possible to achieve good cleaning property, toner fusion resistance, and filming resistance function without excessively pressing the cleaning member against the surface of the photoconductor, that is, while suppressing excessive abrasion of the photoconductor. It has become possible.

Further, the wax and the inorganic fine powder A of the present invention are used.
And B are effective in imparting uniform and stable chargeability to the developer. The mechanism is as follows.

First, since the molecular weight-separated wax used in the present invention is hard and slippery, it is possible to smoothly supply, convey, and replace the developer using the wax to the charge imparting member (for example, developing sleeve, carrier). , The chances of contact increase, and triboelectric charging is likely to occur. Therefore, compared to when using the wax that has been used conventionally,
It shows high chargeability. Moreover, since the inorganic fine powder B improves the fluidity of the developer, the chances of contact of the toner particles with the charging member are equalized, and the toner particles are uniformly charged. Furthermore, since the inorganic fine powder A acts as a microcarrier on the toner and has these various effects, the developer stably exhibits high chargeability, and as a result, it is stable. A good image can be obtained.

Conventionally, when the chargeability of the developer is increased, the developer is excessively charged and the image quality is deteriorated. However, in the present invention, it is possible to make the charge uniform and stable with high chargeability. It was.

The inorganic fine powder A used in the present invention includes magnesium, zinc, aluminum, cobalt,
Examples thereof include oxides such as iron, zirconium, manganese, chromium and strontium, and complex metal oxides such as calcium titanate, magnesium titanate, strontium titanate and barium titanate. Of these, zinc oxide, aluminum oxide, cobalt oxide, manganese dioxide, strontium titanate, and magnesium titanate are preferable because they can exhibit the effects of the present invention.

The inorganic fine powder A used in the present invention is, for example, produced by a sintering method, mechanically pulverized, and then classified by air classification to obtain a desired particle size and particle size distribution.

The inorganic fine powder A in the present invention is the toner 10
It is desirable to use 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight, relative to 0 parts by weight. More preferably 0.2 to 5 parts by weight is used.

The particle size distribution can be measured by various methods, but in the present invention, it was measured using a multisizer.

That is, as a measuring device, a Multisizer II type (manufactured by Coulter) is used, and an interface (manufactured by Nikkaki) for outputting number distribution and volume distribution and CX-
1 Connect a personal computer (made by Canon),
Electrolyte is 1% using special grade or first grade sodium chloride
An aqueous NaCl solution is prepared. As a measuring method, a surfactant as a dispersant in 100 to 150 ml of the electrolytic aqueous solution,
Preferably, the alkylbenzene sulfonate is 0.1 to 5
ml, and 2 to 20 mg of the measurement sample is further added. The electrolytic solution in which the sample was suspended was subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, and the multisizer type II was used as an aperture, and when measuring the particle size of the inorganic fine powder, the aperture was measured using a 13 μm aperture. The volume and number of the inorganic fine powder were measured, and the volume distribution and the number distribution were calculated. Then, the weight-based weight average diameter obtained from the volume distribution according to the present invention was obtained from the volume distribution.

As the inorganic fine powder B used in the present invention, any one can be used as long as it works as a fluidity imparting substance when added to the toner. For example, finely powdered silica such as wet process silica and dry process silica, treated silica obtained by subjecting these silicas to a surface treatment with a silane coupling agent, a titanium coupling agent, silicon oil, alumina, titania, germanium oxide, zirconium oxide, etc. Metal oxides, silicon carbide,
There are carbides such as titanium carbide and nitrides such as silicon nitride and germanium nitride.

The inorganic fine powder B used in the present invention is used in an amount of 0.01 to 8 parts by weight, preferably 0.1 to 4 parts by weight, based on 100 parts by weight of the toner.

A fine powder produced by vapor-phase oxidation of a silicon halogen compound is preferable, so-called dry process silica or fumed silica, which is produced by a conventionally known technique. For example, the thermal decomposition oxidation reaction of silicon tetrachloride gas in oxyhydrogen flame is utilized, and the basic reaction formula is as follows.

SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl Further, in this manufacturing process, by using another metal halogen compound such as aluminum chloride or titanium chloride together with a silicon halogen compound, a fine composite powder of silica and another metal oxide is obtained. It is also possible to obtain the body, including them.

On the other hand, as the method of manufacturing by the wet method, various conventionally known methods can be applied. For example, decomposition of sodium silicate with an acid, Na ₂ O · XSiO ₂ + HCl + H ₂ O → SiO ₂ · nH ₂ O + NaCl, other decomposition of sodium silicate with ammonia salt or alkali salt, sodium silicate There is a method of producing alkaline earth metal silicate and then decomposing it with acid to obtain silicic acid, a method of utilizing natural silicic acid or silicate, and the like.

The weight average diameter of these particles is preferably in the range of 0.001 to 2.0 μm on average of the primary particles,
It is particularly preferable to use fine silica powder having a particle size of 0.002 to 0.2 μm.

Further, it is more preferable to use a treated silica fine powder obtained by subjecting the produced silica fine powder to a hydrophobic treatment. Among the treated silica fine powders, those obtained by treating the silica fine powder so that the degree of hydrophobicity measured by the methanol titration test is in the range of 30 to 90 are particularly preferable.

As a method of hydrophobizing, it is imparted by chemically treating with an organic silicon compound or the like which reacts with or physically adsorbs on silica fine powder. As a preferred method, silica fine powder produced by vapor phase oxidation of a silicon halogen compound is treated with an organosilicon compound.

Examples of such organosilicon compounds are hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allylphenyldichlorosilane, benzyl. Dimethylchlorosilane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, ρ-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxy Silane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyl Disiloxane, 1,3-diphenyltetramethyldisiloxane and 2 to 12 per molecule
For example, there is dimethylpolysiloxane having siloxane units and each terminal unit having a hydroxyl group bonded to Si.

Alternatively, untreated silica fine powder treated with a nitrogen-containing silane coupling agent may be used.

Examples of such treating agents include aminopropyltrimethoxysilane, aminopropyltriethoxysilane, dimethylaminopropyltrimethoxysilane,
Diethylaminopropyltrimethoxysilane, dipropylaminopropyltrimethoxysilane, dibutylaminopropyltrimethoxysilane, monobutylaminopropyltrimethoxysilane, dioctylaminopropyltrimethoxysilane, dibutylaminopropyldimethoxysilane, dibutylaminopropylmonomethoxysilane, dimethyl Aminophenyltriethoxysilane, trimethoxysilyl-γ-propylphenylamine, trimethoxysilyl-γ-propylbenzylamine, trimethoxysilyl-γ-propylpiperidine, trimethoxysilyl-
γ-propylmorpholine, trimethoxysilyl-γ-propylimidazole and the like.

These treatment agents may be used alone or as a mixture of two or more.

The silicone oil is generally represented by the following formula.

[0064]

[Chemical 1] As a preferred silicone oil, one having a viscosity of about 5 × 10 ^{2 to} 5 × 10 ⁵ cm ² / s at 25 ° C. is used. For example, methyl silicone oil, dimethyl silicone oil, phenylmethyl silicone oil, chlorophenylmethyl silicone oil. , Alkyl-modified silicone oil, fatty acid-modified silicone oil, polyoxyalkylene-modified silicone oil and the like are preferable.

Further, silicone oil having a nitrogen atom in its side chain may be used. As such silicone oil, silicone oil having at least a partial structure represented by the following formula can be used.

[0066]

[Chemical 2] (In the formula, R ₁ represents hydrogen, an alkyl group, an aryl group or an alkoxy group, R ₂ represents an alkylene group or a phenylene group, R ₃ and R ₄ represent hydrogen, an alkyl group or an aryl group, and R ₅ Represents a nitrogen-containing heterocyclic group)
The alkyl group, aryl group, alkylene group and phenylene group may have an organo group having a nitrogen atom, or may have a substituent such as halogen within a range not impairing the charging property.

These silicone oils may be used alone or in combination.
Used in mixtures of more than one species.

The specific surface area is BE using nitrogen as an adsorption gas.
It can be determined by the T multipoint method, and degassing is performed at 100 ° C. for 1 hour as a sample pretreatment. (For example, a fully automatic gas adsorption amount measuring device, Autosorb 1, manufactured by Yuasa Ionics, Inc. can be used.) Examples of the binder resin used in the present invention include polystyrene, poly-p-chlorostyrene, and polyvinyltoluene. Of styrene and its substitution products; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid Ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-
Styrene such as vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer -Based copolymer; polyvinyl chloride, phenol resin, natural modified phenol 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, coumarone indene resin, petroleum resin and the like can be used.

A cross-linked styrene copolymer is also a preferable binder resin.

Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate,
Didecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. A monocarboxylic acid having a heavy bond or a substituted product thereof;
For example, a dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate and the like, and its substitution products; for example, vinyl esters such as vinyl chloride, vinyl acetate, vinyl benzoate and the like;
Ethylenic olefins such as ethylene, propylene, butylene, etc .; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, etc .; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, etc .; These vinyl monomers are used alone or in combination of two or more.

As the cross-linking agent, a compound having two or more polymerizable double bonds is mainly used. For example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene, etc .; for example, ethylene glycol diacrylate, Ethylene glycol dimethacrylate,
A carboxylic acid ester having two double bonds such as 1,3-butanediol dimethacrylate; a divinyl compound such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone; and a compound having three or more vinyl groups; Are used alone or as a mixture.

A colorant may be used in the toner of the present invention if necessary.

The colorants 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, rhodamine 6
Conventionally known dyes and pigments such as G, chalco oil blue, chrome yellow, quinacridone, benzidine yellow, rose bengal, triarylmethane dyes, monoazo dyes and disazo dyes may be used alone or in combination.

Further, the toner of the present invention may use a magnetic material if necessary.

Examples of the magnetic material used in the present invention include iron oxides such as magnetite, γ-iron oxide, ferrite and iron-excessive ferrite; metals such as iron, cobalt and nickel; or metals such as these and aluminum and cobalt;
Examples thereof include alloys with metals such as copper, lead, magnesium, tin, zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten and vanadium, and mixtures thereof.

These ferromagnetic materials have an average particle size of 0.1 to 0.1.
1 μm, preferably 0.1 to 0.5 μm, is desirable. The amount contained in the magnetic toner is about 40 to 150 parts by weight with respect to 100 parts by weight of the resin component, and particularly preferably 100 parts by weight of the resin component. 60 to 120 parts by weight.

The developer in the invention may be mixed with a carrier and used as a two-component developer. Carriers that can be used in the present invention include, for example, iron powder, ferrite powder, magnetic powder such as nickel powder, glass beads, and the like, and the surfaces of these resins (for example, fluororesin, silicone resin, styrene-acrylic resin). ) And the like.

For 10 parts by weight of toner, 10 parts of carrier are used.
It is preferable to use ˜1000 parts by weight (preferably 30 to 500 parts by weight). The average particle size of the carrier is 4 to 10
0 μm (preferably 10 to 80 μm, more preferably 2
It is preferably 0 to 60 μm) in matching with the toner according to the present invention.

In the developer of the present invention, it is preferred to use a charge control agent in the developer particles (internal addition) or to mix with the developer particles (external addition). The charge control agent makes it possible to optimally control the charge amount according to the developing system, and particularly in the present invention, it is possible to further stabilize the balance between the particle size distribution and the charge. Examples of the positive charge control agent include modified products of nigrosine and fatty acid metal salts; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonic acid, tetrabutylammonium tetrafluoroborate, and analogs thereof. Onium salts such as certain phosphonium salts and lake pigments thereof, triphenylmethane dyes and lake pigments thereof (as a laker, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid) Acids, ferricyanides, ferrocyanides, etc.) Metal salts of higher fatty acids; diorganotin oxides such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate DOO, diorgano tin borate such as dicyclohexyl tin borate; can be used in combination singly or two or more kinds. Among these, charge control agents such as nigrosine, quaternary ammonium salts and triphenylmethane pigments are particularly preferably used.

In addition, the general formula

[0081]

[Chemical 3] A monomer homopolymer represented by: styrene described above,
A copolymer with a polymerizable monomer such as acrylic acid ester and methacrylic acid ester can be used as a positive charge control agent. In this case, these charge control agents also function as (all or part of) the binder resin.

The following substances control the toner to be negatively charged.

Organic metal complexes and chelate compounds are effective, for example, monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid metal complexes. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

The above charge control agent (which does not act as a binder resin) is preferably used in the form of fine particles. In this case, the number average particle size of this charge control agent is
Specifically, it is preferably 4 μm or less (further, 3 μm or less).

When internally added to the developer, such a charge control agent is preferably used in an amount of 0.1 to 20 parts by weight (more preferably 0.2 to 10 parts by weight) per 100 parts by weight of the binder resin. .

Further, in the present invention, fine powder of the fluorine-containing polymer may be internally or externally mixed. Examples of the fluorine-containing polymer fine powder include, for example, polytetrafluoroethylene, polyvinylidene fluoride and the like and tetrafluoroethylene-vinylidene fluoride copolymer fine powder, and in particular, polyvinylidene fluoride fine powder flows. It is preferable from the viewpoints of the polishing property and the polishing property. The amount added to the toner is 0.01 to 2.0 wt%, especially 0.02 to
1.0 wt% is preferable.

[0087]

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

Wax A was obtained by fractional crystallization from the wax synthesized by the Arge process. Using a Ziegler catalyst, ethylene was low-pressure polymerized to obtain a wax having a relatively low molecular weight, and the low molecular weight fraction was removed by molecular weight fractionation to obtain waxes B and C. Wax D was obtained by thermal decomposition of polyalkylene. These physical properties are shown in Table 1.

[0089]

[Table 1] Example 1 Styrene-butyl acrylate copolymer 100 parts by weight Magnetite 80 parts by weight Nigrosine 2 parts by weight Wax A 4 parts by weight The above materials were premixed and then melt-kneaded by a twin-screw kneading extruder set to 130 ° C. . After cooling the kneaded material, it is roughly pulverized, finely pulverized by a pulverizer using a jet stream, and further classified by an air classifier to obtain a weight average diameter of 8
μm toner was obtained. With respect to 100 parts by weight of the above toner, 1.0 part by weight of strontium titanate having a weight average diameter of 1.1 μm and a hydrophobized specific surface area of 200 m ² /
0.6 part by weight of dry silica was externally added to obtain a developer.

Various evaluations were carried out using a commercially available electrophotographic copying machine NP-1215 (manufactured by Canon Inc.). The results are shown in Table 2.

Example 2 Styrene-butyl acrylate copolymer 100 parts by weight Magnetite 80 parts by weight Nigrosine 2 parts by weight Wax B 4 parts by weight A developer was prepared and evaluated in the same manner as in Example 1 using the above materials. The results are shown in Table 2.

Example 3 Cross-linked polyester resin 100 parts by weight Magnetite 80 parts by weight Quaternary ammonium salt 2 parts by weight Wax C 4 parts by weight Using the above materials, a developer was prepared and evaluated in the same manner as in Example 1. The results are shown in Table 2.

Example 4 Styrene-butyl acrylate copolymer 100 parts by weight Magnetite 80 parts by weight Nigrosine 2 parts by weight Wax A 4 parts by weight To 100 parts by weight of a toner obtained in the same manner as in Example 1 using the above materials. , 1.0 part by weight of cerium oxide having a weight average diameter of 2.3 μm and a specific surface area 130 subjected to a hydrophobic treatment
The dry silica 0.6 parts by weight of m ² / g added externally a developer were prepared and evaluated in the same manner as in Example 1. The results are shown in Table 2.

Example 5 Styrene-butyl acrylate copolymer 100 parts by weight Magnetite 80 parts by weight Nigrosine 2 parts by weight Wax B 4 parts by weight With respect to 100 parts by weight of a toner obtained in the same manner as in Example 1 using the above materials. A developer was prepared by externally adding 1.0 part by weight of aluminum oxide having a weight average diameter of 3.7 μm and 0.6 part by weight of wet silica having a specific surface area of 300 m ² / g and not subjected to a hydrophobizing treatment. Evaluation was performed in the same manner as in Example 1, and the results are shown in Table 2.

Example 6 Styrene-butyl acrylate copolymer 100 parts by weight Quaternary ammonium salt 2 parts by weight Wax A 4 parts by weight Carbon black 4 parts by weight A developer was prepared in the same manner as in Example 1 using the above materials. .

10 parts by weight of this developer and 90 parts by weight of a ferrite carrier (volume average particle size: 35 μm) were mixed,
A two-component toner was evaluated in the same manner as in Example 1, and the results are shown in Table 2.

Comparative Example 1 Styrene-butyl acrylate copolymer 100 parts by weight Magnetite 80 parts by weight Nigrosine 2 parts by weight Wax D 4 parts by weight A developer was prepared and evaluated in the same manner as in Example 1 using the above materials. The results are shown in Table 2.

Comparative Example 2 With respect to 100 parts by weight of the toner obtained in the same manner as in Example 1, 2.0 parts by weight of strontium titanate having a weight average diameter of 5.5 μm and a hydrophobized specific surface area of 200 m ^{2 were used.}
0.6 g by weight of dry silica was added externally to prepare a developer, and the developer was evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 3 To 100 parts by weight of the toner obtained in the same manner as in Example 1, 1.0 part by weight of strontium titanate having a weight average diameter of 1.1 μm and a hydrophobized specific surface area of 20 m ² /
A developer was prepared by externally adding 0.6 part by weight of dry silica (g) and evaluated in the same manner as in Example 1. The results are shown in Table 2.

Comparative Example 4 A developer was prepared in the same manner as in Example 1 except that strontium titanate was not used, and evaluated in the same manner as in Example 1,
The results are shown in Table 2.

Comparative Example 5 A developer was prepared in the same manner as in Example 1 except that dry silica was not used and evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0102]

[Table 2] (Durability test) 20% in an environment of 10% humidity and 15 ° C temperature
Durability test was performed on 000 sheets, and image density, fog, filming of external additives, fusion bonding, and abrasion amount of photosensitive drum (2000
The film thickness difference per 0 sheets and the film thickness difference of 4.0 μm or less were practically usable) were evaluated.

(Blocking Test) Approximately 20 g of the developer was put in a 100 cc poly cup and left standing at 50 ° C. for 3 days, and then visually evaluated.

Excellent: No agglomerates are seen Good: Agglomerates are seen but easily collapsed Yes: Agglomerates are seen but collapsed when shaken No: Aggregates can be grabbed and cannot be easily collapsed

[0105]

According to the present invention, it is a developer which prevents fusing and filming and prevents the photoconductor from being scraped off. It has excellent durability and developability, and a stable and good image is obtained. To be

Front page continuation (72) Inventor Hiroaki Kawakami 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Masatsugu Fujiwara 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. Within

Claims (1)

[Claims] 1. A developer for electrostatic charge image development comprising at least a binder resin, a toner containing a wax and an inorganic fine powder, wherein the wax has a penetration of 4.0 or less and a density of 0.93 or more. A wax which is fractionated by molecular weight, wherein the inorganic fine powder contains an inorganic fine powder A having a weight average diameter of 5.0 μm or less and an inorganic fine powder B having a specific surface area of 30 m ² / g or more. A developer for developing an electrostatic image.