JPH0968822A - Developer for developing electrostatic charge image and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a developer having superior fixability, anti-offsetting property, blocking resistance and developing performance and not causing the fusion of the toner to a developer carrier, a developer regulating member and an electrostatic latent image carrier. SOLUTION: In this developer consisting of toner particles contg. at least a bonding resin, hydrocarbon wax and a colorant, fine resin particles whose particle diameter is smaller than that of the toner particles and inorg. fine powder, the onset temp. of the hydrocarbon wax at the time of temp. rise on its DSC curve is within the range of 65-105 deg.C and the peak temp. is within the range of 75-120 deg.C. The fine resin particles have been surface-treated with silicone oil having 50-60,000cSt viscosity and have 0.05-2.0μm average particle diameter.

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 image such as electrophotography and electrostatic printing, and an image forming method using the developer.

[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.
Although many methods are known as described in JP-B No. 43-24748 and Japanese Patent Publication No. 43-24748, generally, a photoconductive substance is used and an electric latent image is formed on a photoreceptor by various means. Then, the latent image is developed with toner to form a visible image, and the toner image is transferred to a transfer material such as paper as necessary, and then the toner image is fixed on the transfer material by heat or pressure. To obtain a copy, and the remaining toner which has not been transferred onto the photoreceptor is cleaned by various methods, and the above steps are repeated.

In recent years, such a copying apparatus is not only a general purpose copying machine for copying an original document, but also a digital printer as a computer output or a copy of a highly detailed image such as a graphic design. Started to be used.

Therefore, higher reliability has been rigorously pursued, and accordingly, the required performance has become higher, and if an improvement in the performance of the image forming method including toner cannot be achieved, a better machine is established. It's gone.

By the way, the fixing performance is the most important performance required of the toner in the digital printer and the copying of the high-definition image.

Regarding the fixing process, various methods and devices have been developed, but the most popular method at present is a pressure heating method using a heating roller.

In the pressure-bonding heating method using a heating roller, fixing is performed by allowing the toner image surface of the sheet to be fixed to pass under pressure while contacting the surface of a heat roller having a surface formed of a material having releasability for toner. It is something to do. In this method, since the surface of the heat roller and the toner image on the sheet to be fixed are brought into contact with each other under pressure, the thermal efficiency at the time of fusing the toner image on the sheet to be fixed is extremely good, and rapid fixing is possible. It is possible and very effective in a high speed electrophotographic copying machine. However, in the above method, since the surface of the heat roller and the toner image are in contact with each other in a molten state under pressure, a part of the toner image may adhere to and transfer to the surface of the fixing roller to stain the next sheet to be fixed ( Offset phenomenon). Preventing toner from adhering to the surface of the heat fixing roller is one of the essential conditions of the heat roller fixing method.

Further, recently, a fixing device has been put into practical use, which is replaced by a heat roller and is composed of a pressure member that is in pressure contact with a heating body and is in close contact with the heating body through a film, and has a thermal efficiency. However, since the toner surface is melted, the offset phenomenon is more likely to occur, and it is more necessary to prevent this.

Japanese Unexamined Patent Publication Nos. 52-3304 and 52-52
-3305, JP-A-57-52574, JP-A-61-138259, JP-A-56-8705.
No. 1, JP-A-63-188158, JP-A-6
Japanese Patent Laid-Open No. 3-113558 discloses a technique of incorporating waxes in the toner.

Waxes are used to improve the offset resistance of toner and the fixability at low temperatures. However, on the other hand, while improving these performances, the blocking resistance is deteriorated, the developability is deteriorated when exposed to heat due to the temperature rise of a copying machine, and the developability is deteriorated due to blooming of wax when left for a long time. It gets worse.

Further, these waxes are difficult to be uniformly dispersed in the toner, and the wax which is free or unevenly distributed is liable to adversely affect the developability and the like, and there is still room for improvement.

On the other hand, a corona discharger is known as a charging means in an electrophotographic apparatus or the like. However, the corona discharger needs to apply a high voltage, and thus has a problem that a large amount of ozone is generated.

Recently, it has been considered to use contact charging means without using a corona discharger. Specifically, a voltage is applied to a conductive roller, which is a charging member, to bring the roller into contact with a photosensitive member, which is a member to be charged, to charge the surface of the photosensitive member to a predetermined potential. If such a contact charging means is used, the voltage can be lowered and the ozone generation amount can be reduced as compared with the corona discharger.

For example, Japanese Patent Publication No. 50-13661 proposes to use a roller having a cored bar covered with a dielectric material made of nylon or polyurethane rubber, and apply a low voltage to the photosensitive paper to charge it. .

However, as described above, the toner of which the fixing property is improved by the waxes is likely to be plastically deformed, and therefore, in the image forming process in which the toner is pressure-contacted by the contact charging. Toner fusion and filming easily occur on the contact charging member and the photoconductor. In the extreme case, image loss is likely to occur.

Regarding the addition of resin fine particles to the developer, it is proposed to add spherical or nearly spherical polymer particles smaller than the toner particles to the developer, as described in JP-A-60-186854. There is.

When a developer was prepared and examined in the same manner as described above, the effect of preventing toner fusion on the photosensitive member was small, and in the apparatus using contact charging, the contact charging device was contaminated.
The uneven charging was likely to occur.

On the other hand, in recent years, small and inexpensive personal use copying machines and laser printers have appeared, and in these small machines, from the standpoint of maintenance-free, a cartridge system in which a photoconductor, a developing device, a cleaning device, etc. are integrated. Is used, and it is desirable to use a magnetic one-component developer because the structure of the developing device can be simplified as a developer.

In the method using such a magnetic one-component developer, it is necessary for the developer to have a uniform charging property in order to obtain an image of good quality. Therefore, the layer thickness of the developer layer is regulated by pressing with a regulation blade formed of an elastic material such as silicone rubber,
A method of applying a developer on a developer carrying member such as a developing sleeve may be used.

When the above-mentioned method is used, the toner whose fixing property is particularly improved by the waxes as described above is apt to be plastically deformed, so that the toner is fused to the developing sleeve or the regulating blade. May occur,
It tends to cause image defects such as uneven image density and white spots.

In Japanese Patent Application Laid-Open No. 4-274444,
Although a proposal has been made for treating resin particles with oil, in this invention, although sufficient effect can be seen for voids in transfer, under a severe environment of use, sufficient fixing property and offset resistance and development sleeve and regulation blade can be obtained. It was difficult to satisfy all of the effects of preventing toner fusion of the above.

[0022]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a developer for developing an electrostatic charge image and an image forming method which solve the above-mentioned conventional problems.

That is, an object of the present invention is to provide a developer for developing an electrostatic charge image, which can be fixed at a low temperature and is excellent in offset resistance and blocking resistance.

Further, an object of the present invention is to develop an electrostatic charge image which does not cause toner fusion on the electrostatic image holder (photoreceptor), developer carrier (developing sleeve) and developer regulating member (regulating blade). It is to provide a developer and an image forming method.

[0025]

SUMMARY OF THE INVENTION The present invention provides an electrostatic charge composed of toner particles containing at least a binder resin, a hydrocarbon wax and a colorant, resin fine particles smaller than the particle size of the toner particles and inorganic fine powder. In the developer for image development, the onset temperature at the time of temperature rise in the DSC curve of the hydrocarbon wax is in the range of 65 to 105 ° C., the peak temperature is in the range of 75 to 120 ° C., and the resin fine particles are The present invention relates to a developer for developing an electrostatic charge image, comprising resin fine particles having a viscosity of 50 to 60,000 cSt and surface-treated with a silicone oil and having an average particle diameter of 0.05 to 2.0 μm.

Further, according to the present invention, a charging step in which a charging member externally applied with a voltage is brought into contact with the electrostatic latent image holding member to carry out charging, and an electrostatic latent image is formed on the charged electrostatic latent image holding member. In the image forming method, there is a step, and a step of developing the electrostatic latent image formed on the electrostatic latent image holding member by regulating the developer on the developer carrying member by a developer regulating member, The developer is an electrostatic charge image developing developer composed of toner particles containing at least a binder resin, a hydrocarbon wax and a colorant, and resin fine particles smaller than the particle size of the toner particles and inorganic fine powder. The onset temperature of the hydrocarbon wax in the DSC curve at the time of temperature rise is 65 to
The temperature is in the range of 105 ° C., the peak temperature is in the range of 75 to 120 ° C., and the resin fine particles have a viscosity of 50 to 60,000 c.
The present invention relates to an image forming method, characterized in that resin particles having an average particle diameter of 0.05 to 2.0 μm are surface-treated with a silicone oil of St.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION The wax used in the present invention has an onset temperature of 6 when the temperature is raised in the DSC curve of the wax.
It is characterized by being at 5 to 105 ° C. By using such a wax, a developer having excellent blocking resistance and fixability can be obtained.

When the onset temperature is less than 65 ° C., the toner particles undergo plastic change from a relatively low temperature, so that the blocking resistance is inferior and the developability is apt to deteriorate with increasing temperature. On the other hand, when the temperature exceeds 105 ° C., the rate of plastic change due to heating becomes slow and the low temperature offset resistance and fixability become poor.

Further, the wax used in the present invention is characterized in that the endothermic peak temperature at the time of temperature rise in the DSC curve is in the range of 75 to 120 ° C., whereby good fixing property and high temperature offset resistance can be obtained. . However, if the endothermic peak temperature is less than 75 ° C., the wax component is dissolved in the binder resin before the temperature becomes high, and it is difficult to obtain sufficient offset resistance at high temperature. On the other hand, 120 ° C
When it exceeds, it is difficult to obtain sufficient fixability.

That is, since the binder resin for the developer used for heat fixing enters the viscoelastic region where fixing is possible from around 100 ° C., melting of the wax component in this temperature region has a plasticizing effect on the resin. Can be increased, the fixability can be improved, the releasing effect can be sufficiently exerted, and the offset resistance can be improved. Therefore, since it does not wind around the fixing roller or the film and does not rely on the separating claws, it hardly causes nail marks, does not stain the pressure roller, and does not wind around the pressure roller.
If the above conditions are satisfied, peaks may exist in other regions.

Further, the wax used in the present invention has a number average molecular weight (Mn) of 200 to 2500 and a weight average molecular weight (M
It is more preferable that w) is 400 to 5000 and Mw / Mn is 3 or less.

By having a molecular weight in the above range, the developer can have favorable thermal characteristics. That is, when the molecular weight is smaller than the above range, it is likely to be excessively affected by heat, resulting in poor blocking resistance and developability. When the molecular weight is larger than the above range, heat from the outside cannot be effectively used, and it is difficult to obtain excellent fixing property and anti-offset property. On the other hand, when Mw / Mn is larger than 3, the melting behavior is not sharp with respect to heat due to the wide molecular weight distribution, and it becomes difficult to obtain a region satisfying both good fixability and offset resistance.

Further, in the present invention, the hydrocarbon wax is represented by the following formula (1), (2) or (3).

[0034]

[Chemical 7] [In formula, x shows an average value and is 35-150. ]

[0035]

Embedded image [In the formula, x represents an average value of 35 to 150, z represents an average value of 1 to 5, and R represents hydrogen or a carbon number of 1 to 1.
It represents 0 alkyl groups. ]

[0036]

Embedded image [In formula, y shows an average value and is 35-150. ] It is more preferable to use a compound characterized by being a long-chain hydrocarbon compound represented by

The hydrocarbon wax having the above structure is obtained by polymerizing ethylene, for example, using a Ziegler catalyst, and after the completion of the polymerization, oxidizes to produce an alkoxide of the catalyst metal and polyethylene. After that, hydrolysis is performed to obtain the hydrocarbon wax represented by the formula (1). Further, a hydrocarbon wax represented by the formula (2) was obtained by reacting this hydrocarbon wax with a substance having an epoxy group. Further, the hydrocarbon wax of the formula (3) is obtained by oxidizing the hydrocarbon wax of the formula (1).

The hydrocarbon wax thus obtained has a small amount of branching and a sharp molecular weight distribution, and does not adversely affect the image.

The hydrocarbon wax used in the present invention contains 30% by weight of a hydrocarbon compound having no functional group.
The amount may be less than (more preferably 25% by weight or less).

Further, in the present invention, it is more preferable to use the hydrocarbon wax of the above formula (1) which is excellent in dispersibility with the binder resin.

The toner particles of the present invention can satisfy the fixability and anti-offset property at a high level as described above, but on the other hand, the toner particles exhibiting excellent fixability at low temperature are easily affected by heat. Therefore, when the temperature around the developing device is increased, such as when a large number of printouts are made in a high temperature environment, a plastic change is likely to occur. When the toner particles in such a state are pressed between the developing sleeve and the regulating blade as described above, toner fusion occurs on the developing sleeve and the regulating blade, which causes a decrease in image density and white spots. .

Further, when the toner particles excellent in fixability at a low temperature as described above are used in the image forming method of charging the photoconductor using the contact charging member, the toner is fused to the photoconductor. Is likely to occur.

On the other hand, it is an essential condition for the toner of the present invention to add an inorganic fine powder as an additive. One of the purposes is to improve the fluidity of the developer by reducing the cohesive force between the toner particles, maintain a stable charging property, and improve the occurrence of toner bridging in the developing device. That's why.

Further, the inorganic fine powder used in the present invention is
It is preferably hydrophobized with a silicon compound.
By adding the hydrophobically treated inorganic fine powder to the toner particles to form a developer, the developer is stably charged even in various environments, and a good image can be obtained.

However, when an inorganic fine powder is added as an additive, when a large number of printouts are carried out, the developer is rubbed against the developer carrying member (so-called developing sleeve) and the regulating blade, so that the toner particle surface is In some cases, the release of inorganic fine powder from the product may increase.

Since this free inorganic fine powder has a small particle size and a high charge amount, it easily adheres to the developing sleeve,
In particular, in a developing method in which the regulating blade is in contact with the developing sleeve, it causes damage to the developing sleeve and the regulating blade, and is a cause of occurrence of toner fusion to the developing sleeve and the regulating blade.

Since the surface of the resin fine particles used in the present invention has a constant viscosity and is treated with silicone oil, the above-mentioned free inorganic fine powder can be adsorbed on the surface of the resin fine particles. This has the effect of making it difficult to cause toner fusion to the sleeve and the regulation blade.

Further, since a constant amount of silicone oil is supplied from the surface of the resin fine particles to the developing sleeve and the regulating blade, it is possible to provide releasability between the developing sleeve and the regulating blade and the toner particles, and wax Due to the effect, the fixing property is improved. It is easily plastically changed, and toner fusion is relatively likely to occur. Even if toner particles are used, toner fusion to the developing sleeve and the regulation blade is unlikely to occur.

In addition, by regulating the viscosity of the silicone oil, it is possible to maintain a stable image even when printing out a large number of sheets, without excessively contaminating the developing sleeve or the regulating blade with the silicone oil. is there.

In the present invention, the resin fine particles treated with silicone oil act as a spacer between the toner particles and the developing sleeve or the regulating blade, so that the toner particles do not come into contact with the developing sleeve or the regulating blade or become difficult to come into contact therewith. It is considered that the toner is less likely to be fused due to the above action.

The silicone oil used in the present invention is
The viscosity is 50 to 60,000 cSt, more preferably 1,
200 to 30,000 cSt is used.

When the viscosity is less than 50 cSt, the viscosity of the silicone oil is too low and the ability to take in the free inorganic fine powder is small. In addition, because of its low viscosity and good fluidity,
Difficult to be carried on the surface of resin particles.

If it is larger than 60,000 cSt,
Since the viscosity is too high, the silicone oil is not uniformly dispersed and a lump adheres to the developer, whereby aggregates are easily generated in the developer.

The resin fine particles used in the present invention preferably have an average particle diameter of 0.05 to 2.0 μm, more preferably 0.1 to 1.5 μm.

If the average particle size is smaller than 0.05 μm,
The tribo of the developer is high, charge-up tends to occur, and the image density tends to decrease. Further, since the particle size is too small, it is difficult to obtain the effect as a spacer. When the average particle size is larger than 2.0 μm, the difference between the particle size of the toner particles is small and the adhesion to the surface of the toner particles is weak. In the developing sleeve, the regulating blade, and the effect of preventing the toner from being fused to the photosensitive member.

The resin fine particles used in the present invention preferably have a surface area shape sphericity of 0.50 to 0.90. When compared with a true sphere, as shown schematically in FIG. Since it has the property of holding the silicone oil on the surface of the resin fine particles, it is possible to improve the fusion of the toner to the developing sleeve and the regulation blade even under severe conditions such as generation of free inorganic fine powder. .

Surface area shape When the sphericity is larger than 0.90, a large amount of silicone oil cannot be carried on the surface because the specific surface area of the resin fine particles is small, and under severe conditions, it cannot be applied to the developing sleeve or the regulating blade. In some cases, sufficient effect for preventing toner fusion may not be obtained. 0.50
If it is smaller, the resin fine particle surface has a large number of irregularities, and therefore the convex portion of the resin fine particle surface is easily chipped during mixing with the toner particles or during the development process, and many resin fine particle fragments are present in the developer. This may cause image defects.

The Vickers hardness of the resin fine particles used in the present invention is preferably 5.0 to 30.0 kg / mm ² . If the Vickers hardness is greater than 30.0 kg / mm ² , the resin fine particles have a high hardness, and therefore the resin fine particles themselves may damage the developing sleeve or the charging member. Furthermore, the inorganic fine powder incorporated in the silicone oil on the surface is used as a resin. In some cases, it is difficult to take in the particles, and the effect of preventing toner fusion with the developing sleeve or the regulating blade may be small. Vickers hardness of 5.0 kg / mm ²
If it is smaller, the hardness of the resin fine particles is too low, and the deformation between the developing sleeve and the regulation blade or between the contact charging member and the photoconductor is large, and the resin particles are thinly extended, so that the silicone oil can be stably held. In some cases, it may not be possible, and the ability to take up the inorganic fine particles in a free state becomes low, and the effect may be small.

The resin fine particles used in the present invention are produced by a soap-free polymerization method, an emulsion polymerization method or the like. Preferably, resin fine particles obtained by polymerizing monomers such as styrene, acrylic acid, methyl methacrylate, butyl acrylate, and 2-ethylhexyl acrylate alone or in combination of two or more kinds show good effects. Further, it may be crosslinked with divinylbenzene or the like.

The particle size of the resin fine particles in the present invention can be measured by various methods. In the present invention, the particle size was measured by using an electron micrograph. That is, the electron microscope S-
800 (Hitachi, Ltd.) was used to take a photograph at a magnification of 10,000 to 20,000 times, and 1 was randomly selected from the photographed resin fine particles.
From 0 to 200 pieces were extracted, the diameter from each convex portion was measured using a device such as a caliper, and the averaged diameter was used as the particle diameter of the resin fine particles.

The silicone oil which can be used for treating the resin fine particles used in the present invention is generally represented by the following formula:

[0062]

Embedded image R: C _1-3 alkyl group R ′: Silicone oil modifying group such as alkyl, halogen-modified alkyl, phenyl, modified phenyl R ″: C _1-3 alkyl group or alkoxy group

Examples thereof include dimethyl silicone oil, alkyl-modified silicone oil, α-methylstyrene-modified silicone oil, chlorophenyl silicone oil, fluorine-modified silicone oil and the like. The silicone oil preferably has a viscosity at 25 ° C. of about 50 to 60,000 cSt.

As a method for treating the silicone oil, a known technique is used. For example, the resin fine particles and the silicone oil may be directly mixed by using a mixer such as a Henschel mixer, or the resin fine particles may be sprayed with the silicone oil. It depends on the method.

When the viscosity of the silicone oil is high, the silicone oil is finely dispersed or dissolved in a dispersant such as ethanol or a solvent using a homogenizer or the like, and then the known technique as described above. It is preferable to use a method in which the treatment is carried out by using, and then the resin fine particles are dried at a temperature not higher than Tg.

The amount of silicone oil treated is preferably 1 to 40% by weight, more preferably 3 to 25% by weight, based on the resin fine particles.

The Vickers hardness (Hv) of the resin fine particles is measured as follows.

First, about 0.3 g of resin fine particles are weighed and molded with a tablet molding machine at a pressure of 400 (kg / cm ² ) for 5 minutes to have a diameter of 10 to 15 mm and a thickness of 2 to 2.5 mm.
Mold resin fine particles. The Vickers hardness (Hv) of the molded resin fine particles is measured using a micro hardness meter (manufactured by Akashi Seisakusho Co., Ltd.) under the conditions of a load of 25 g and a holding time of 20 seconds.

The molded resin fine particles are allowed to stand in an environment of room temperature of 25 ° C. and humidity of 60% RH for 24 hours and then measured in the same environment.

The surface area shape sphericity (Ψ) of the resin fine particles is defined as follows.

[0071]

[Equation 1]

The BET specific surface area can be measured by, for example, QUAN.
When the specific surface area meter Autosorb 1 manufactured by TACHROME is used, examples of the measuring method include the following.

About 0.3 g of resin fine particles were weighed in a cell,
Deaeration is performed at a temperature of 40 ° C. and a degree of vacuum of 1.0 × 10 ⁻³ mmHg for 1 hour or more. Thereafter, nitrogen gas is adsorbed in a state of being cooled by liquid nitrogen, and a value is obtained by a multipoint method.

The surface area when the resin fine particles are assumed to be true spheres is, for example, an electron micrograph (× 1000) of the resin fine particles.
From 0), 100 resin fine particle images are randomly selected, their major diameters are measured, and the average diameter value is defined as the diameter when the resin fine particles are assumed to be true spheres. Based on this diameter, the radius γ of the resin fine particles is determined, and further, the surface area (4πγ ² ) of the resin fine particles is determined. In addition, the volume of resin particles

[0075]

[Equation 2] And the weight of the resin fine particles is determined from the density of the resin fine particles and the volume. From the obtained surface area and the weight, the surface area (m ² / g) assuming that the resin fine particles are spherical is determined.

The onset temperature and peak temperature in the DSC curve of the hydrocarbon wax used in the present invention are
It can be obtained from the DSC curve measured by a differential scanning calorimeter. For example, as the measuring device, DSC-7 manufactured by Perkin Elmer can be used.

The measuring method is ASTM D3418-82.
Perform according to. The DSC curve used in the present invention has a temperature of 10 ° C./min after the temperature is raised once and the previous history is taken.
After the temperature is lowered in the range of 0 to 200 ° C., the DSC curve measured when the temperature is raised is used. The definition of each temperature is defined as follows.

(Onset temperature when the wax is heated) See FIG. 2. Minimum temperature at which the curve differential value becomes maximum (peak temperature when the wax is heated) See FIG. 3 Endothermic peak top temperature

The content of these hydrocarbon waxes is 20 parts by weight or less with respect to 100 parts by weight of the binder resin.
It is effective to use it in an amount of 0.5 to 10 parts by weight, and it may be used in combination with other waxes as long as it does not adversely affect.

The molecular weight of the hydrocarbon wax used in the present invention can be measured by the following method.

(GPC measurement conditions) Apparatus: GPC-150C (Waters Co.) Column: GMH-HT 30 cm 2 series (manufactured by Tosoh Corporation) Temperature: 135 ° C. Solvent: o-dichlorobenzene (addition of 0.1% ionol) Flow rate: 1. 0 ml / min sample: 0.4 ml injection of 0.15% sample

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

Among the inorganic fine powders used in the present invention, particularly preferable ones are produced from dry silica produced by vapor phase oxidation of a silicon halogen compound, which is so-called dry method or fumed silica, and water glass. Both of the so-called wet silicas mentioned can be used. Of these, dry silica having less silanol groups on the surface and inside the fine silica powder and having no production residue such as Na ₂ O or SO ₃ ²⁻ is preferable. In the case of dry silica, it is possible to obtain a composite fine powder of silica and another metal oxide by using another metal halogen compound such as aluminum chloride or titanium chloride together with a silicon halogen compound in the manufacturing process. In the present invention, the inorganic fine powder also includes them.

The particle size of the inorganic fine powder is preferably in the range of 0.001 to 2 μm as the average primary particle size,
It is particularly preferable to use a fine silica powder having a particle size within the range of 0.002 to 0.2 μm.

The inorganic fine powder used in the present invention is preferably hydrophobic.

For the hydrophobizing treatment, conventionally known hydrophobizing agents and methods such as silane coupling agents are used. As a more preferable hydrophobizing agent, a silicon compound having an organosiloxane unit such as silicone oil or silicone varnish can be used.

The developer of the present invention is preferably a one-component developer having a magnetic toner containing a magnetic material in toner particles. In this case, the magnetic material also serves as a coloring agent. The magnetic substance contained in the magnetic toner includes iron oxides such as magnetite, hematite and ferrite; metals such as iron, cobalt and nickel, or these metals and aluminum, cobalt, copper, lead, magnesium and tin,
Examples include alloys with metals such as zinc, antimony, beryllium, bismuth, cadmium, calcium, manganese, selenium, titanium, tungsten, vanadium, and mixtures thereof.

[0088] magnetic material preferably has a BET specific surface area by the nitrogen adsorption method 1-20 m ² / g, especially 2.5~12m ² /
g is good. Further, magnetic powder having a Mohs hardness of 5 to 7 is preferable. The content of the magnetic powder is 10 to 7 relative to the weight of the toner.
0% by weight is good.

These magnetic materials have an average particle size of 0.1 to 2
The amount contained in the toner is preferably 20 to 200 parts by weight, and particularly preferably 40 to 100 parts by weight, based on 100 parts by weight of the resin component. 150 parts by weight is even better.

Other colorants that may be used in the developer include any suitable pigment or dye.

Examples of pigments include carbon black, aniline black, acetylene black, naphthol yellow, hansa yellow, rhodamine lake, alizarin lake, red iron oxide, phthalocyanine blue, and indanthrene blue. These are used in an amount sufficient to maintain the optical density of the fixed image. It is preferable to use 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight of the pigment, relative to 100 parts by weight of the resin. Further dyes are used for the same purpose. For example, there are azo dyes, anthraquinone dyes, xanthene dyes, methine dyes,
It is preferable to use 0.1 to 20 parts by weight, preferably 0.3 to 10 parts by weight of the dye, based on 100 parts by weight of the resin.

As the binder resin used in the developer of the present invention, the following binder resins can be used.

For example, polystyrene, homopolymers of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene and the like, and substitution products thereof; styrene-p-chlorostyrene copolymers, styrene-vinyltoluene copolymers, 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 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, etc. can be used. Preferred binders include styrene copolymers or polyester resins.

Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate,
Duplex 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 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 substituted compounds thereof; for example, vinyl chloride,
Vinyl esters such as vinyl acetate, vinyl benzoate, etc .; ethylene-based olefins such as ethylene, propylene, butylene, etc .; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, etc .; for example vinyl methyl ether, vinyl Vinyl monomers such as ethyl ether, vinyl isobutyl ether, and other vinyl ethers; and the like are used alone or in combination of two or more.

The styrene-based polymer or styrene-based copolymer may be crosslinked or may be a mixed resin thereof.

Among the charge control agents used in the developer of the present invention, examples of the negative charge control agent include azo metal complexes represented by the following general formula (I).

[0097]

Embedded image

Specific examples of the complex are shown below.

[0099]

[Chemical 12]

[0100]

Embedded image

On the other hand, there are the following substances as the positive charge control agent.

Modified products of nigrosine and fatty acid metal salts; quaternary ammonium acids such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate and tetrabutylammonium tetrafluoroborate;
And their analogs, such as onium salts such as phosphonium salts, lake pigments thereof, triphenylmethane dyes and lake pigments thereof (as the laker, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannin Acids, lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.) Metal salts of higher fatty acids; dibutyltin oxide, dioctyltin oxide, diorganotin oxide such as dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate, dicyclohexyltin borate Such as diorgano tin borate; guanidine compound, imidazole compound. These can be used alone or in combination of two or more. Among these, a triphenylmethane compound and a quaternary ammonium salt whose counter ion is not halogen are preferably used. The general formula (1)

[0103]

Embedded image [R ₁ : H, CH ₃ R ₂ , R ₃ : a substituted or unsubstituted alkyl group (preferably C _{1 to} C ₄ )], a monomer homopolymer represented by the above-mentioned styrene, acrylate, A copolymer with a polymerizable monomer such as 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.

A compound represented by the following general formula (2) can also be used in the constitution of the present invention.

[0105]

[Chemical 15] [Wherein R ¹ , R ² , R ^3, R ⁴ , R ⁵ , and R ⁶ are the same or different from each other, a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group] Represents a group. R ⁷ , R ⁸ and R ⁹ each represent a hydrogen atom, a halogen atom, an alkyl group or an alkoxy group, which may be the same or different. A ⁻ is an anion such as sulfate ion, nitrate ion, borate ion, phosphate ion, hydroxide ion, organic sulfate ion, organic sulfonate ion, organic phosphate ion, arbonic acid ion, organic borate ion, or tetrafluoroborate ion. Show. ]

External additives may be added to the developer of the present invention if necessary.

For example, a charging auxiliary agent, a conductivity-imparting agent, a fluidity-imparting agent, an anti-caking agent, a releasing agent at the time of heat roll fixing,
Inorganic fine particles that act as lubricants and abrasives.

Lubricants such as Teflon, zinc stearate and polyvinylidene fluoride, among which polyvinylidene fluoride is preferred. Alternatively, abrasives such as cerium oxide, silicon carbide, and strontium titanate are preferable, and strontium titanate is particularly preferable. Alternatively, for example, a fluidity-imparting agent such as titanium oxide or aluminum oxide, among which a hydrophobic agent is particularly preferable. A small amount of an anti-caking agent or a conductivity-imparting agent such as carbon black, zinc oxide, antimony oxide, tin oxide, etc., or white particles and black particles having opposite polarities can be used as a developing property improver.

[0109]

Although the basic structure and features of the present invention have been described above, the present invention will be specifically described based on the following examples. However, this does not limit the embodiment of the present invention at all. The numbers of parts in the examples are parts by weight.

Table 1 shows the physical properties of the resin fine particles used in Examples and Comparative Examples, and Table 2 shows the physical properties of the wax.

[0111]

[Table 1]

[0112]

[Table 2]

Example 1 Styrene-butyl acrylate-monobutyl maleate copolymer 100 parts (copolymerization ratio 75/20/5, 2 peaks P ₁ / P ₂ = 10,000 / 1,000,000, Mw / Mn = 50)・ Magnetic fine powder (BET 7.5 m ² / g) 100 parts ・ Negative charge control agent (monoazo iron complex) 2 parts ・ Hydrocarbon wax A 4 parts

After the above materials were premixed, they were melt-kneaded by a twin-screw kneading extruder set at 130 ° C.
The kneaded product was cooled, coarsely pulverized, finely pulverized by a pulverizer using a jet stream, and further classified by an air classifier to obtain toner particles having a weight average particle diameter of 6.5 μm. 100 parts of this toner particle and 1.0 powder of negatively charged hydrophobic silica
Parts and 0.2 parts of the resin fine particles a treated with silicone oil were mixed with a Henschel mixer to obtain a developer.

(Preparation of Developing Sleeve-1) -Graphite 70 parts (Nippon Graphite Co., Ltd., major axis diameter 80 μm) -Carbon black 30 parts (Columbia Chemical Co., Conducttex 900, oil absorption 120 cc / 100 g) -Resol type phenol resin 100 parts-Cured spherical resol type phenolic resin particles 4 parts (Positive charging, particle size 4 μm)

The above coating material was added to 76 parts of butyl alcohol, mixed, and then dispersed for 10 hours in a ball mill containing balls having a diameter of 200 μm as media particles. Thereafter, the balls were separated using a 64 mesh sieve to obtain a stock solution (solid content: 24% by weight).

60 parts of butyl alcohol was added to the stock solution to prepare a coating solution (solid content: 15% by weight). A coating film of 10 μm was formed from the coating liquid on the Al carrier substrate (aluminum cylinder) having a diameter of 20 mm by the dipping method, and then the coating liquid was heated and cured in a hot air drying oven at 150 ° C./30 minutes to prepare a developing sleeve.

The surface roughness (Ra) of the coating layer formed on the aluminum substrate was 2.5 μm.

Next, the developer thus prepared was evaluated by the following method.

As the electrophotographic apparatus, a commercially available Canon LBP-A309GII, as shown in FIG. 1, was used by improving the printing speed to 1.5 times. The cartridge is a Canon EP-B cartridge modified to a structure that allows toner replenishment, and the developing sleeve is prepared-
Replace with the one obtained in 1 and print 15,000 sheets under high temperature and high humidity environment (30.0 ° C / 80% RH) while replenishing the developer, developing sleeve, regulating blade, photosensitive The toner fusion state to the body and the image density were evaluated. Table 3 shows the evaluation results.

(1) Developability The image density was evaluated by maintaining the image density at the end of printing 15,000 sheets on ordinary plain paper for copiers (75 g / m ² ).
The image density was measured by using a "Macbeth reflection densitometer" (manufactured by Macbeth Co., Ltd.) with respect to a printout image of a white background portion having a document density of 0.00.

◯: 1.40 or more Δ: 1.30 or more and less than 1.40 X: less than 1.30

(2) Fusion of Developing Sleeve After completion of the printout test, the occurrence of scratches on the surface of the developing sleeve, the state of toner fusion and the influence on the printout image were visually evaluated.

⊚: Very good (not generated) ○: Good (almost no occurrence) Δ: Practical (possible fusion, but little influence on image) X: Not practical (large fusion, image) It causes unevenness)

(3) Toner fusion of the regulating blade After the printing out, scratches on the surface of the regulating blade and the toner fusion state were visually confirmed.

⊚: Very good ∘: Good (almost no occurrence) Δ: Practical use possible (toner fusion occurs, but does not affect the image) ×: No (image defect)

(4) Fusion of Photoreceptor The state of occurrence of scratches on the surface of the photoconductor drum and toner fusion and the influence on the printout image were visually evaluated.

◯: Good (not generated) Δ: Practical (possible fusion and scratches, but little influence on the image) X: Not practical (many fusion caused vertical stripe-shaped image defects)

(5) Fixability The fixability was evaluated by rubbing the fixed image with a soft thin paper by applying a load of 50 g / cm ² , and the reduction rate (%) of the image density before and after the rubbing.

Good (good): less than 10% Fair (good): 10% or more, less than 20% Poor (not possible): 20% or more

(6) Anti-Offset Property The anti-offset property was evaluated by printing out a sample image having an image area ratio of about 5% and measuring the degree of stain on the image after 3000 sheets.

◯: Good Δ: Practical use ×: Practical use not possible

(7) Blocking test Approximately 20 g of the developer was put in a 100 cc poly cup and the amount of the developer was 50.
After leaving it at 3 ° C. for 3 days, it was visually evaluated.

A: No aggregate is observed. Δ: Aggregates can be seen but easily collapse. X: Aggregates can be grabbed and are not easily broken.

Similarly, the following Examples 2 to 8 and Comparative Example 1 were performed.
The same evaluations as in Example 1 were performed on the developers shown in FIGS. Table 3 shows the evaluation results.

Example 2 A developer was prepared in the same manner as in Example 1 except that wax B was used instead of wax A and resin particles c were used instead of resin particles a.

Example 3 A developer was prepared in the same manner as in Example 1 except that the resin particles b were used instead of the resin particles a.

Example 4 A developer was prepared in the same manner as in Example 1 except that wax C was used instead of wax A.

Example 5 A developer was prepared in the same manner as in Example 1 except that wax D was used instead of wax A.

Example 6 A developer was prepared in the same manner as in Example 1 except that wax B was used instead of wax A and resin particles d were used instead of resin particles a.

Example 7 A developer was prepared in the same manner as in Example 1 except that wax E was used instead of wax A.

Example 8 A developer was prepared in the same manner as in Example 1 except that the resin particles e were used instead of the resin particles a.

Comparative Example 1 A developer was prepared in the same manner as in Example 1 except that wax F was used instead of wax A and resin particles f were used instead of resin particles a.

Comparative Example 2 A developer was prepared in the same manner as in Example 1 except that the wax G was used instead of the wax A and the resin fine particles were not added.

Comparative Example 3 A developer was prepared in the same manner as in Example 1 except that wax H was used instead of wax A and resin particles g were used instead of resin particles a.

[0146]

[Table 3]

[0147]

EFFECTS OF THE INVENTION According to the present invention, the use of the above-mentioned hydrocarbon wax and resin fine particles has excellent fixing properties, anti-offset properties, anti-blocking properties, and developability, and can be used as a developer carrier and a developer control agent. It is possible to provide a developer for developing an electrostatic charge image that does not cause toner fusion to the member and the electrostatic latent image carrier.

[Brief description of drawings]

FIG. 1 shows an example of the appearance of resin fine particles used in the present invention.

FIG. 2 is a schematic explanatory diagram of a DSC curve of the hydrocarbon wax used in the present invention when the temperature is raised.

FIG. 3 is a schematic explanatory diagram of an image forming apparatus used in an embodiment of the present invention.

[Explanation of symbols]

 1 developing device 2 developer container 3 latent image carrier 4 transfer means 5 laser light or analog light 6 developing sleeve 7 cleaning blade 8 regulating blade 11 charging means 12 bias applying means 13 developer 14 cleaning means 15 magnetic field generating means 20 heating body 21 fixing roller 22 pressure roller

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Shunji Suzuki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (15)

[Claims] 1. A developer for electrostatic charge image development comprising toner particles containing at least a binder resin, a hydrocarbon wax and a colorant, and resin fine particles smaller than the particle size of the toner particles and inorganic fine powder. The onset temperature at the time of heating in the DSC curve of the hydrocarbon wax is in the range of 65 to 105 ° C., the peak temperature is in the range of 75 to 120 ° C., and the resin fine particles are silicone oil having a viscosity of 50 to 60,000 cSt. The surface-treated average particle size is 0.05 to 2.
A developer for developing an electrostatic charge image, which is resin fine particles having a size of 0 μm. 2. The resin fine particles have a viscosity of 1200 to 300.
The developer for developing an electrostatic charge image according to claim 1, wherein the developer is resin fine particles treated with silicone oil of 00 cSt. 3. The hydrocarbon wax has a number average molecular weight (Mn) of 200 to 2500 and a weight average molecular weight (Mw).
Is 400-5000, and its molecular weight distribution Mw /
Mn is 3 or less, The electrostatic image developing developer of Claim 1 or 2 characterized by the above-mentioned. 4. The hydrocarbon wax is represented by the following formula (1), (2) or (3): [In formula, x shows an average value and is 35-150. ] [Chemical 2] [In the formula, x represents an average value of 35 to 150, z represents an average value of 1 to 5, and R represents hydrogen or a carbon number of 1 to 1.
It represents 0 alkyl groups. ] [In formula, y shows an average value and is 35-150. ] The developer for electrostatic charge image development according to any one of claims 1 to 3, which is a long-chain hydrocarbon compound represented by the formula [4]. 5. The resin fine particles have a particle diameter of 0.1 to 1.5 μm.
5. The developer for developing an electrostatic charge image according to claim 1, wherein the developer is m. 6. The surface area shape sphericity (Ψ) of the resin fine particles
Is 0.5 to 0.9 and Vickers hardness is 5.0 to 3
The developer for developing an electrostatic charge image according to claim 1, wherein the developer is 0.0 kg / mm ² . 7. The inorganic fine powder is silica fine powder hydrophobized with a silicon compound.
7. The developer for developing an electrostatic charge image according to any one of 1 to 6. 8. A charging step of charging by charging an electrostatic latent image holding member with a charging member to which a voltage is applied from the outside, and a step of forming an electrostatic latent image on the charged electrostatic latent image holding member,
And an electrostatic latent image formed on the electrostatic latent image bearing member, wherein the developer is regulated by a developer regulating member on the developer carrying member to develop the image. Is a developer for electrostatic charge image development composed of toner particles containing at least a binder resin, a hydrocarbon wax and a colorant, and resin fine particles smaller than the particle size of the toner particles and inorganic fine powder. The on-set temperature at the time of temperature rise in the DSC curve of the system wax is in the range of 65 to 105 ° C., the peak temperature is in the range of 75 to 120 ° C., and the resin fine particles are surface-treated with a silicone oil having a viscosity of 50 to 60,000 cSt. The average particle size is 0.05-2.
An image forming method, wherein the resin fine particles are 0 μm. 9. The developer carrying member and the developer regulating member are in contact with each other, and the developer carrying member contains graphite, carbon black or a mixture of graphite and carbon black, and a number average particle diameter of 0.03 to 30 μm. Spherical particles of
The image forming method according to claim 8, wherein the image forming method is coated with a coating agent containing a binder resin. 10. The resin fine particles have a viscosity of 1200 to 30.
The image forming method according to claim 8 or 9, which is resin fine particles treated with silicone oil of 000 cSt. 11. The hydrocarbon wax has a number average molecular weight (Mn) of 200 to 2500 and a weight average molecular weight (Mw).
Is 400-5000, and its molecular weight distribution Mw /
The Mn is 3 or less, and the Mn is 3 or less.
The image forming method according to any one of the above. 12. The hydrocarbon wax has the following formula (1), (2) or (3): [In formula, x shows an average value and is 35-150. ] [In the formula, x represents an average value of 35 to 150, z represents an average value of 1 to 5, and R represents hydrogen or a carbon number of 1 to 1.
It represents 0 alkyl groups. ] [In formula, y shows an average value and is 35-150. ] The image forming method according to any one of claims 8 to 11, which is a long-chain hydrocarbon compound represented by 13. The resin fine particles have a particle size of 0.1 to 1.5.
13. The image forming method according to claim 8, wherein the image forming method is μm. 14. The resin fine particles have a surface area shape sphericity (Ψ) of 0.5 to 0.9 and a Vickers hardness of 5.
The image forming method according to claim 8, wherein the image forming method is 0 to 30.0 kg / mm ² . 15. The image forming method according to claim 8, wherein the inorganic fine powder is silica fine powder that has been hydrophobized with a silicon compound.