JP3110184B2 - Non-magnetic one-component developer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a developer, and more particularly, to a non-magnetic one-component developer for visualizing an electrostatic latent image formed on a photosensitive member or a dielectric by an electrophotographic apparatus or an electrostatic recording apparatus. About.

[0002]

2. Description of the Related Art Fine colloidal silica (silica fine particles produced by a gas phase method) or the like is externally added as a fluidizing agent to colored fine particles comprising at least a binder resin and a coloring agent (that is, the colored fine (Independently added) is used as a "toner", and a two-component developer composed of the toner and a carrier is widely used because of good image quality.

However, on the other hand, the following disadvantages are common to two-component developers. That is

(1) Toner receives a triboelectric charge due to mutual friction between the toner and the carrier. However, if the toner is used for a long period of time, a film of the toner is formed on the surface of the carrier. It becomes impossible to obtain, and fog etc. occur.

(2) The mixing ratio of the toner and the carrier must be adjusted within a predetermined range. However, if a two-component developer is used for a long period of time, the mixing ratio fluctuates and deviates from the predetermined range. That is, the image quality is not stable. Also, it is difficult to control the mixing ratio.

(3) In general, iron powder or glass beads whose surface is oxidized are often used as a carrier, but the surface of the photoreceptor is mechanically damaged by these carriers, and the life of the photoreceptor is shortened. .

(4) After a certain period of use, the developer needs to be replaced, so that maintenance cannot be omitted.

(5) Since a large amount of carrier is indispensable in addition to the toner, the size cannot be reduced.

Therefore, in recent years, without using a carrier,
Various developing methods using a magnetic one-component developer containing a magnetic powder in a toner have been proposed (for example, US Pat. No. 3,909,258, US Pat. No. 4,121,931).
issue).

However, these known methods also have the following disadvantages. (1) Since the magnetic one-component developer contains a large amount of magnetic powder having a small electric resistance, it is difficult to increase the charge amount.
As a result, it is difficult to electrostatically transfer the image of the developer on the photoconductor to a support member such as plain paper. In particular, sufficient transfer performance cannot be obtained in a humid atmosphere.

(2) Since a large amount of black magnetic powder is contained, it is difficult to colorize the developer. (3) Since a large amount of magnetic powder is contained, the fixing power of the magnetic one-component developer is lower than that of the two-component developer. As a result, the temperature and pressure of the fuser must be increased,
Running cost increases.

Recently, attention has been paid to a developing method using a non-magnetic one-component developer having high resistance without containing magnetic powder. For example, US Pat. No. 2,895,847 and US Pat. No. 3,152,01
No. 2, Japanese Patent Publication No. 41-9475, Japanese Patent Publication No. 45-2877
And those based on touch-down or impression development described in JP-B-54-3624.

In these methods, among the developers used in the conventional two-component developing system, a toner excluding a carrier is used as a non-magnetic one-component developer. However,
In this case as well, various problems related to the non-magnetic one-component developer occur as described below.

(1) There is a phenomenon that the developer adheres to the developing roll, the developing blade, and the photosensitive member. In the conventional two-component developer, a large amount of carriers such as iron powder and glass beads are mixed in addition to the toner, so that the toner temporarily adheres to the developing roll, the developing blade, and the photoconductor. Was polished by the carrier and was not a problem.

However, when a conventional non-magnetic one-component developer is used, the developer adheres to a developing roll, a developing blade, and a photoreceptor when used for a long time, and a film of the developer is formed. There were many things. When such a film of the developer is formed, the developer to be charged and the developing roll or the developing blade cannot be brought into sufficient contact with each other, resulting in insufficient charging of the developer, thereby deteriorating the image quality. Also,
When the developer adheres to the photoreceptor, it becomes a black stain and appears on the image, which causes a problem of deterioration in image quality.

Further, if the conventional rubber developing blade has been used for a long period of time, fogging and fraying, which are considered to be caused by deterioration and bleeding of the oligomer having a low molecular weight, occur, and the life of the developing device is remarkably increased. It was shrinking, and the demand for improvement was strong. The present inventor has made various studies on this point, and it has been found that a metal blade can improve the situation.

However, when a metal blade is used in the non-magnetic one-component developing system, the pressure on the developing roller is likely to be partially large, and the blade is hard to be worn. As a result, the developer adheres to the metal blade. It also turned out to be easier. As described above, with the use of a metal blade, it is desired to further improve the durability of the developer.

On the other hand, conventionally, in order to improve the durability of the developer, for example, JP-B-48-8141 and JP-B-51-11-11.
No. 30, JP-A-50120631, and JP-A-52-847
No. 41, No. 60-186851, and the like have proposed methods of mixing an additive into a developer composition.

That is, Japanese Patent Publication No. 48-8141 discloses an organic polymer having a low surface energy such as polytetrafluoroethylene and polyvinylidene fluoride, and Japanese Patent Publication No. 51-1130 discloses a non-adhesive polymer having a triboelectric charging sequence smaller than that of sulfur. Japanese Patent Application Laid-Open No. 50-120631 discloses a non-adhesive polymer having a triboelectric series smaller than sulfur and an abrasive such as colloidal silica, and Japanese Patent Application Laid-Open No. 52-84741 discloses polystyrene particles. No. 60-188851, an acrylic polymer fine powder is added to a developer, and poor cleaning or cleaning of the surface of a developing roller, a developing blade, and a photoreceptor is caused by a decrease in adhesion or a polishing effect. The purpose is to prevent film generation.

Although these methods are useful to some extent in terms of preventing poor cleaning or developer film formation, according to the study of the present inventor, a metal blade is used as the developing blade and used for a long time. In this case, the above-mentioned organic fine particles as additives remained on the developing roller or the photoreceptor without being developed, and the developer was partially whitened. More specifically, the number of prints is about 5000
At ~ 10,000 sheets, a decrease in image density and an increase in fog occurred, and finally a phenomenon that printing was not possible occurred.

(2) In the non-magnetic one-component developing method, if the fluidity of the developer is low, the supply of the developer becomes insufficient, and the image is blurred or the image density is reduced. Usually, in a two-component developer, the iron powder carrier or the like can be forcibly moved by the magnetism of the magnetic roller, and therefore, the influence on the developer supply failure due to the decrease in the fluidity of the toner itself is small. Similarly, in a magnetic one-component developer, the developer itself can be forcibly moved by a magnetic roller.

As described above, it is important to improve the fluidity from the viewpoint of the supply of the developer, but according to the study of the present inventors, the layer thickness of the developer on the developing roller has a high fluidity. The thicker it becomes. Therefore, it is important to improve the fluidity in order to maintain a high image density.

(3) In the non-magnetic one-component developing method, fogging is easy if the chargeability is low. As described above, in the two-component development method or the one-component magnetic development method, the developer is easily charged by magnetic force because the developer is forcibly stirred. However, in the non-magnetic one-component developing method, the charging of the developer depends on the friction between the developing roller and the developing blade. Therefore, if the charging ability of the developer is not large, fogging easily occurs, and the charging property becomes extremely important.

[0024]

SUMMARY OF THE INVENTION An object of the present invention is to overcome the problems of the prior art and to provide sufficient fluidity and chargeability as a developer used in a contact development or a non-contact development system. High image density, low fog,
An object of the present invention is to provide a non-magnetic one-component developer which gives an image having a high image quality level.

Another object of the present invention is to prevent a film from being formed on a developing roll, a developing blade (especially a metal blade) or a photoreceptor due to adhesion of a developer even when used for a long period of time, thereby deteriorating image quality. The object of the present invention is to provide a non-magnetic one-component developer free of any problem. Still another object of the present invention is to provide a non-magnetic one-component developer having stable image quality without separation of organic fine particles as an abrasive in a developer even when used for a long time.

[0026]

Means for Solving the Problems As a result of intensive studies, the present inventor has found that, in a developer applied to a contact development or a non-contact development method using a metal developing blade, a coloring agent comprising a binder resin and a coloring agent is used. It has been found that the above object can be achieved by mixing a specific amount of organic fine particles having a small particle diameter comprising a polymer or a copolymer with a specific amount of silica fine particles.

The non-magnetic one-component developer of the present invention is based on the above findings. More specifically, a metal developing blade is arranged as a developing blade for regulating the layer thickness of the developer so as to be in pressure contact with the surface of the developing roll. A developer used in a method of uniformly applying a developer on the surface of a developing roll, directly contacting the developing roll with an electrostatic latent image on a photoconductor, or facing the non-contact, and developing. It consists of a binder resin and a colorant, is spherical in shape, and has a degree of sphericity of 0.8 or more, relative to 100 parts by weight of colored fine particles, and is made of a polymer or a copolymer and has a charge amount of -40 to -100 μm.
It is obtained by mixing 0.01 to 5.0 parts by weight of organic fine particles falling within the range of c / g and 0.1 to 2.0 parts by weight of silica fine particles.

According to a preferred embodiment of the present invention, the colored fine particles are spherical, the degree of sphericity is 0.8 or more, and the colored fine particles are negatively charged. A magnetic one-component developer is provided.

According to a preferred aspect of the present invention, the organic fine particles are fine particles produced by a polymerization method, and the fine particles have a spherical shape and a particle diameter in a range of 0.01 to 3 μm. A one-component developer is provided.

[0030]

Hereinafter, the developer of the present invention will be described in detail.

The non-magnetic one-component developer (developing process) The present invention, a developing blade for regulating the layer thickness of the developer (especially metal blade, i.e., at least a blade whose surface is made of a metal) developing roll surface The developer used in the method of applying the developer uniformly to the surface of the developing roll, directly contacting the developing roll with the electrostatic latent image on the photoconductor, or facing the non-contact, and developing Agent.

As the metal blade, it is preferable to use a blade made entirely of metal from the viewpoint of elasticity and cost. As the metal constituting the metal blade, stainless steel is preferably used in terms of elasticity, corrosion resistance, and cost. The thickness of the metal blade is preferably about 1 mm or less (more preferably about 0.3 mm or less).

One embodiment of a developing device and a developing method to which the developer of the present invention can be applied will be described with reference to FIG. As shown in FIG. 1, the developer 4 contained in the developer container 5
Is moved between the developing roll 2 and the developing blade 3 by the stirring bar 6, where the developer is forcibly thinned and charged.

The photoreceptor 1 is charged in advance with a charger wire 9 and irradiated with a light signal or an optical image 10 to form an electrostatic latent image. Then, the developer on the developing roll 2 is applied to the photoreceptor 1. The electrostatic latent image is developed by contact. Next, using a transfer charger line 11, the developed developer (a visualized image composed of the developer) on the photoreceptor is transferred to a support member 13 such as paper, and is passed through a fixing roll 12, where the developer is transferred. Is fixed on the support member 13.

The developer or toner on the photoreceptor after the transfer is removed by a blade method, a web method, a roll method or the like. The removed toner may be discarded, or collected and reused. As described above, the developer of the present invention is particularly effective in a system in which the developing roller is brought into direct contact with the electrostatic latent image on the photoreceptor to perform development. In such a contact development method, since a toner film is easily formed on the photoreceptor, the effect of the organic fine particles contained in the developer of the present invention as a polishing agent is easily exerted.

(Developer) The non-magnetic one-component developer of the present invention comprises colored fine particles 1 comprising at least a binder resin and a colorant.
A mixture of 0.01 to 5.0 parts by weight of organic fine particles made of a polymer or copolymer obtained by polymerizing various monomers and 0.1 to 2.0 parts by weight of silica fine particles with respect to 00 parts by weight. It is.

(Colored Fine Particles) In the present invention, fine particles containing at least a binder resin and a colorant are used as the colored fine particles.

The monomer composition of the binder resin constituting the colored fine particles is not particularly limited, and those commonly used as a binder resin for toner (for example, the same as the monomer composition for organic fine particles described later) ) Can be used. In the present invention, it is preferable to use a copolymer of styrene and an acrylic acid ester or a methacrylic acid ester from the viewpoints of charging stability and preventing detachment of organic fine particles based on this.

Dyes and pigments are used as the colorant, and those generally used as toner colorants can be used. In order to obtain good dispersion in the colored fine particles, a dispersing agent having a polar group introduced into a part of the polymer chain is dyed, and about half of the pigment is added to carry out polymerization to obtain colored fine particles. Is also good.

The colored fine particles contain at least a binder resin and a colorant as described above. In addition, for example, a charge controlling agent or an anti-offset agent made of a low molecular weight substance such as wax, polyethylene, or polypropylene may be used, if necessary. Can be used (for example, internally added).

The above-mentioned colored fine particles may be obtained by a polymerization method, a granulation method such as a spray drying method, or a pulverization method.

When the colored fine particles are obtained by a polymerization method, fine particles polymerized by various polymerization methods can be used.
For example, the polymerization may be performed by emulsion polymerization, soap-free emulsion polymerization, suspension polymerization, or the like while maintaining the liquid monomer component in a spherical state as droplets.

In the present invention, the polymer obtained by the above-described polymerization method, solution polymerization, bulk polymerization, etc.
Colored fine particles may be obtained by granulation by a granulation method such as a spray drying method.

In the case of obtaining colored fine particles by a pulverizing method, for example, an ordinary toner formulation is blended, and the mixture is melted and mixed by a kneader.
After cooling, it may be roughly crushed, finely crushed, and classified.

In the present invention, the average particle size of the colored fine particles is preferably from 2 to 20 μm, more preferably from 6 to 12 μm.

The colored fine particles produced by the above-described polymerization method, granulation method, pulverization method and the like are preferably formed into spheres by mechanical or thermal treatment, if necessary.

To make the shape spherical, (1) in order to increase the fluidity of the developer, (2) the toner obtained by developing the electrostatic latent image on the photoreceptor is electrostatically applied to an image holding material such as paper. In order to increase the transfer rate at the time of transfer, (3) further, when used for a long period of time, the formation of the developer film on the developing roller, the developing blade and the photoconductor by the adhesion of the developer is performed. It is preferable from the viewpoint of obtaining a small amount of developer.

The degree of spheroidization of the colored fine particles is preferably 0.8 or more (more preferably 0.9 or more) in sphericity as described later.

(Organic Fine Particles) As the organic fine particles used in the present invention, those obtained by polymerization using various polymerization methods can be used. That is, organic fine particles formed into particles by emulsion polymerization, soap-free emulsion polymerization, suspension polymerization, or the like, or each of the above polymerization methods or solution polymerization,
After dissolving a polymer obtained by bulk polymerization or the like in a solvent, organic fine particles granulated by a spray drying method or the like or organic fine particles obtained by a method such as mechanical pulverization can be used.

The molecular weight of the polymer or copolymer constituting the organic fine particles according to the present invention is not particularly limited, and a polymer having an arbitrary molecular weight can be used without departing from the object of the present invention.

The glass transition point of the polymer or copolymer constituting the organic fine particles is preferably room temperature (25 ° C.) or higher, more preferably 50 ° C. or higher.

Specific examples of the monomers constituting the organic fine particles according to the present invention include the following compounds.

That is, styrene, o-methylstyrene, m
-Methylstyrene, p-methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene,
2,4-dimethylstyrene, pn-butylstyrene,
Styrene such as p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene and derivatives thereof; ethylene, Ethylene unsaturated monoolefins such as propylene, butylene and isobutylene; vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride; vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate; Methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate,
Isobutyl methacrylate, n-octyl methacrylate,
Α-methylene aliphatic monocarboxylic esters such as dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, and diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, Acrylic esters such as propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate and phenyl acrylate; vinyl methyl ether, vinyl Vinyl ethers such as ethyl ether and vinyl isobutyl ether;
Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, vinyl methyl isopropenyl ketone; N-vinyl compounds such as N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole, N-vinyl pyrrolidone; vinyl naphthalenes; acrylonitrile; There are vinyl monomers such as acrylic acid or methacrylic acid derivatives such as methacrylonitrile and acrylamide.

As the organic fine particles according to the present invention, a polymer or copolymer obtained by polymerizing one or more of these monomers can be used. The composition of the resin obtained by polymerization is not limited, but a styrene-based copolymer,
Methyl methacrylate-based copolymers, vinyl chloride-based copolymers and the like are preferably used from the viewpoint of high hardness and polishing effect.

In the present invention, when polymerizing the monomer composition, a cross-linking agent such as described below may be used to perform polymerization to form a cross-linked polymer.

As the crosslinking agent, divinylbenzene,
Divinyl naphthalene, divinyl ether, divinyl sulfone, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, ethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, 1, 6-hexane glycol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, propylene glycol dimethacrylate, 2,2 '
-Bis (4-methacryloxydiethoxyphenyl) propane, 2,2'-bis (4-acryloxydiethoxyphenyl) propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate,
Tetramethane tetraacrylate, dibromoneopentyl glycol dimethacrylate, diallyl phthalate, etc.
A general crosslinking agent can be appropriately used.

As the organic fine particles according to the present invention, a polymer or copolymer obtained by polymerizing one or more of these crosslinking agents can be used.

The amount of the crosslinking agent used is 0.001 to 15% by weight, more preferably 0.1 to 15% by weight, based on the total amount of the monomers.
Preferably it is used at 10% by weight.

When the organic fine particles themselves (single product) are negatively charged, the charge amount is preferably in the range of -40 to -100 μc / g. Absolute value of charge amount is -40μ
When it is smaller than c / g, the organic fine particles are easily separated from the colored fine particles, and when the absolute value is larger than -100 μc / g, the image quality is apt to be fogged.

When the range of the charge amount is inappropriate (out of the above range), it is preferable that the organic fine particles contain a charge control agent. When a charge control agent is contained, for example, a method of dissolving the charge control agent in a monomer before polymerization to give organic fine particles and then polymerizing the monomer is preferably used.

As the organic fine particles, those produced by a polymerization method are preferably used, and the shape is preferably spherical. It is preferable that the organic fine particles have a spherical shape, since the fluidity of the developer is hardly reduced.

The organic fine particles have an average particle size (B).
Is smaller than the average particle size (A) of the colored fine particles, and the average particle size of the organic fine particles is preferably 0.01 to 3 μm. If the particle size is smaller than 0.01 μm, it is difficult to exhibit a polishing effect, and if the particle size is larger than 3 μm, the fluidity is reduced and the image quality is apt to be reduced. The ratio of these average particle sizes (B
/ A) is preferably from 1/200 to 1/2.
When B / A is less than 1/200, the polishing effect tends to be insufficient, and when B / A exceeds 1/2, the fluidity as a developer tends to be insufficient.

As the organic fine particles, those obtained by polymerization using various polymerization methods can be used. That is, the polymerization may be carried out by emulsion polymerization, soap-free emulsion polymerization, suspension polymerization, or the like while maintaining the liquid monomer component in a spherical state as droplets. The polymer granulated as described above is preferably used in the present invention, but the polymer obtained by the above polymerization method or solution polymerization, bulk polymerization, etc., is dried and granulated by using a spray drying method or the like. Can also be used as organic fine particles.

The amount of the organic fine particles used is 100
The amount is 0.01 to 5.0 parts by weight, preferably 0.1 to 1.0 part by weight based on parts by weight. If the amount is less than 0.01 part by weight, the polishing effect is insufficient, and if it is more than 5 parts by weight, the fluidity is reduced and the image quality is reduced.

(External Additive) In addition to the above-mentioned colored fine particles and organic fine particles, the developer of the present invention may contain silica fine particles as an external additive in an amount of 0.1 to 2.0 parts per 100 parts by weight of the colored fine particles.
Contains parts by weight. The addition amount of the silica fine particles is preferably 0.2 to 0.5 parts by weight. When the amount is less than 0.1 parts by weight, the fluidity and transferability are reduced, and when the amount is more than 2.0 parts by weight, fogging occurs.

As the silica fine particles, colloidal silica (silica fine particles produced by a gas phase method) is preferably used. As the colloidal silica, it is particularly preferable to use colloidal silica treated with a hydrophobizing agent such as silicone oil or hexamethyldisilazane.

Hereinafter, the present invention will be described more specifically with reference to Examples and Comparative Examples, but the present invention is not limited to only these Examples. In addition, evaluation of the physical property in this invention was performed by the following method.

(Fluidity) The fluidity of the developer was measured and evaluated using a powder tester manufactured by Hosokawa Micron Corporation. That is, a certain amount of the developer is weighed, and 6
The sample was placed on a 0-mesh sieve and vibrated for 15 seconds at a constant amplitude (Slidac scale = 2.5), and the amount of passing toner was converted to the weight per minute and displayed.

(Blow-off charge amount) The charge amount of the organic fine particles was determined by the following method. That is, Powder Tech Co., Ltd.
59.7 g of carrier TEFV150 / 250 and 0.3 g of organic fine particles were weighed, placed in a 200 cc SUS pot, and triboelectrically charged by rotating at 150 rpm for 30 minutes, using a blow-off meter manufactured by Toshiba Chemical Corporation.
The organic fine particles were blown off at a pressure of 1 kg / cm ² of nitrogen gas, and the charge amount was measured.

(Degree of Sphericalization) In the measurement of the degree of sphericity of the colored fine particles, several electron micrographs of the fine particles were taken, and a place where the entire volume of one powder became clear was selected. From inside, the longest diameter (long diameter) and the shortest diameter (short diameter)
Was selected and measured, and 100 values obtained by dividing the minor axis by the major axis were determined. The average value was determined, and this value was defined as the degree of sphericity.

(Image Characteristics) As a durability test, 20,000 sheets were printed using the developing device shown in FIG. 1, and the image density, the presence or absence of fog, and the presence or absence of a film due to the adhesion of the developer to the metal developing blade were visually observed. Was evaluated.

The image density (ID) was evaluated by using a Macbeth reflection densitometer and measuring the "black solid portion". The image characteristics were evaluated in the following three stages.

(Image density) ：: Image density is high (image density exceeds 1.3) Δ: Image density is slightly low (image density = 1.1 to 1.3) ×: Image density is low (image density) (Density less than 1.1) (fogging) 無 い: no fogging Δ: some fogging is observed ×: fogging occurs (durability) ○: no blurring even after printing 20,000 sheets △: slight fogging after printing 20,000 sheets Fuzzy ×: Fuzzy on the way when 20,000 sheets are printed

Example 1 (Production of Colored Fine Particles by Polymerization Method) First, a dispersion aid used for producing colored fine particles was produced.

(Production of Dispersing Aid) A dispersing aid was produced by introducing a compound having> C ＝ N ⁺ <bond into a polymer having an unsaturated bond. Styrene / butadiene = 9
100 g of a styrene-butadiene random copolymer having a molecular weight of MW = 50,000 at 0/10 is dissolved in 500 mL of benzene, put into a reaction vessel equipped with a stirrer, a thermometer reflux condenser and a reagent inlet, and then stirred. While heating to 60 ° C.

Benzylidenebutylamine (Ph-CH =
N—C ₄ H ₉ ) and acetyl chloride (CH ₃ COC)
l) and tin tetrachloride in an amount of 0.1 mol each were added to the above reaction vessel and reacted for 1 hour. After the completion of the reaction, the reaction product was poured into 1 liter of methanol and completely coagulated. Next, this product was dried in a vacuum dryer to obtain a dispersing aid.

(Production of colored fine particles) 70 parts by weight of styrene, 30 parts by weight of butyl methacrylate, 4 parts by weight of the dispersion aid obtained above, 8 parts by weight of carbon black (trade name: PRINTEX 150T, manufactured by Degussa), Cr Dye (trade name: Bontron S-34, manufactured by Orient Chemical Industries) 0.5
2 parts by weight of 2,2'-azobis (2,4-dimethylvaleronitrile) were dispersed in a ball mill at room temperature to obtain a uniform mixed solution.

Next, the above mixed solution was mixed with calcium phosphate 5
It was added to 350 parts by weight of distilled water in which the parts by weight were finely dispersed to obtain a dispersion. The dispersion was subjected to high-shear stirring with a rotor-stator-type homomixer under the condition of pH 9 or more, and the mixture was pulverized and dispersed in water.

Next, this aqueous dispersion of the monomer was placed in a 1 L (liter) four-necked flask equipped with a stirrer, thermometer, nitrogen inlet tube and reflux condenser, and stirred at 65 ° C. for 4 hours. Was polymerized.

The polymer dispersion thus obtained was sufficiently washed with acid and water, then separated and dried to obtain a toner material as colored fine particles. The particle size of the obtained colored fine particles was 11.8 μm in volume average particle size, and the sphericity was 0.97.

(Production of Organic Fine Particles) In a 1 L four-necked flask equipped with a stirrer, a thermometer, a nitrogen inlet tube and a reflux condenser, 80 parts by weight of styrene monomer, 20 parts by weight of acrylonitrile, 0.5 part by weight of divinylbenzene Parts by weight, 200 parts by weight of distilled water, 0.6 parts by weight of potassium persulfate, 4 parts by weight of polyoxyethylene nonylphenol, and 1 part by weight of sodium lauryl sulfate were subjected to emulsion polymerization at 80 ° C. for 4 hours in a nitrogen stream.

After completion of the polymerization, the reaction solution was cooled to 20 ° C., and the average particle size was 0.3 μm using an ultrafiltration apparatus and a hot air drier.
m spherical organic fine particles were obtained. The charge amount of the obtained organic fine particles was -62 μc / g.

(Preparation of developer) 100 parts by weight of the colored fine particles obtained above were mixed with 0.5 parts by weight of the above organic fine particles and 0.3 parts of colloidal silica hydrophobized with silicone oil.
Parts by weight, and mixed with a Henschel mixer to obtain a developer. The fluidity of the obtained developer was as good as 52 g / min.

(Evaluation) Opening the developing section of a commercially available laser beam printer (OL-800, manufactured by Oki Electric Industry Co., Ltd.)
Instead of a rubber developing blade, a metal developing blade 3 (stainless steel, thickness 0.1 mm) as shown in FIG. 1
Was attached, and the developer obtained above was added and evaluated. As a result, the initial print quality was maintained even after printing 20,000 sheets.
Good results were obtained.

Comparative Example 1 A developer was prepared and evaluated in the same manner as in Example 1 except that no organic fine particles were added. As a result, the image density was reduced after printing 3,000 sheets, the occurrence of blurring was observed, and a film due to the adhesion of the developer to the metal developing blade was observed.

Comparative Example 2 A developer was produced in the same manner as in Example 1 except that colloidal silica hydrophobized with silicone oil was not mixed in the production of the developer of Example 1. The fluidity of the developer thus obtained was a low value of 25 g / min. When the above developer was evaluated in the same manner as in Example 1, the image density was low from the beginning, and the developer was not usable.

Example 2 80 parts by weight of methyl methacrylate and 20 parts by weight of acrylic acid were polymerized in the same manner as in the preparation of the organic fine particles of Example 1. The particle size of the obtained organic fine particles is 0.4 μm, and the charge amount is −6.
It was 4 μc / g.

The organic fine particles of 0.3 part by weight were used in Example 1
Was added together with 0.3 parts by weight of colloidal silica to 100 parts by weight of the colored fine particles used in the above to prepare a developer. The fluidity of the developer thus obtained was 55 g / min.
When this developer was evaluated in the same manner as in Example 1, good results were obtained as in the case of Example 1.

Example 3 Organic fine particles were produced as follows. An autoclave equipped with a stirrer was charged with 180 parts by weight of distilled water, 0.17 parts by weight of lauroyl peroxide, 1.0 part by weight of sodium dodecylbenzenesulfonate, 1.9 parts by weight of chlorinated paraffin, and 20 parts by weight of methyl methacrylate. After the space was replaced with nitrogen, 80 parts by weight of a vinyl chloride monomer was introduced and mixed.

Next, the mixed dispersion was homogenized with a homogenizer, and then stirred and stirred at 50 ° C. under a can pressure of 4.0 kg.
/ Cm ² . After the polymerization is completed,
The mixture was cooled to 0 ° C., and spherical organic fine particles having an average particle diameter of 0.3 μm were obtained by using an ultrafiltration device and a hot-air dryer.

The charge amount of the organic fine particles thus obtained was -68 μc / g. 0.5 parts by weight of the organic fine particles and 0.3 parts by weight of colloidal silica were added to and mixed with 100 parts by weight of the colored fine particles used in Example 1 to prepare a developer. The fluidity of the developer thus obtained is 58 g.
/ Min. When the developer was evaluated in the same manner as in Example 1, good results were obtained as in Example 1.

Example 4 100 parts by weight of styrene, 0.5 part by weight of ethylene glycol dimethacrylate, and 0.5 part by weight of a charge controlling agent (TN-1001 manufactured by Hodogaya Chemical Co., Ltd.) Polymerization was carried out as in the production. The particle size of the obtained organic fine particles was 0.3 μm, and the charge amount was −54 μc / g. 0.3 parts by weight of the organic fine particles were added to 100 parts by weight of the colored fine particles used in Example 1 together with 0.3 parts by weight of colloidal silica to prepare a developer. The fluidity of the developer thus obtained was 60 g / min. When this developer was evaluated in the same manner as in Example 1, good results were obtained as in the case of Example 1. The results obtained as described above are collectively shown in Table 1.

[0094]

[Table 1]

The meanings of the abbreviations used in Table 1 are as follows. Abbreviation: ST: Styrene MMA: Methyl methacrylate BMA: Butyl methacrylate AA: Acrylic acid AN: Acrylonitrile VC: Vinyl chloride DVB: Divinylbenzene EGDMA: Ethylene glycol dimethacrylate

[0096]

As described above, according to the present invention, as a developer used in a contact developing method or a non-contact developing method using a metal developing blade, the developer has sufficient fluidity and chargeability, and has a high image density. The present invention provides a non-magnetic one-component developer which gives an image having a low image fog and a high image quality level.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view showing one embodiment of a developing device and a developing method to which a non-magnetic one-component developer can be applied.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Photoconductor 2 Developing roll 3 Developing blade (made of metal) 4 Developing agent 5 Developing agent container 6 Stirring bar 7 Cleaning blade 8 Waste toner box 9 Charger wire 10 Optical signal, optical image 11 Transfer charger wire 12 Fixing roll 13 Developer support Materials (paper, etc.)

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Tomio Yamada 1-2-1, Yakko, Kawasaki-ku, Kawasaki-shi, Kanagawa Prefecture Inside the Research and Development Center of Zeon Corporation (72) Inventor Kazunori Shigemori Kawasaki-ku, Kawasaki-shi, Kanagawa 1-1-2 Nikko Zeon Co., Ltd. Research and Development Center, Japan (72) Inventor Katsuhiro Hasegawa 1-1-2 Yakko, Kawasaki-ku, Kawasaki-shi, Kanagawa Japan Zeon Co., Ltd. Research and Development Center (72) Inventor Jun Saito 1-2-1 Yoko, Kawasaki-ku, Kawasaki City, Kanagawa Prefecture Inside the Research and Development Center of Zeon Corporation (56) References JP-A-64-77075 (JP, A) JP-A-59-218460 (JP, A JP-A-61-273556 (JP, A) JP-A-4-143767 (JP, A) JP-A-1-302271 (JP, A)

Claims (4)

(57) [Claims] A metal developing blade is disposed as a developing blade for regulating the layer thickness of the developer so as to be in pressure contact with the surface of the developing roll. A developer used in a method in which a developing roll is brought into direct contact with or non-contact with an image, and is used in a developing method. The developer comprises at least a binder resin and a coloring agent, and has a spherical shape, and has a degree of sphericity. 0.8 to 100 parts by weight of colored fine particles, 0.01 to 5.0 parts by weight of organic fine particles comprising a polymer or a copolymer and having a charge amount in the range of -40 to -100 μc / g; A non-magnetic one-component developer obtained by mixing 0.1 to 2.0 parts by weight of fine particles. 2. The non-magnetic one-component developer according to claim 1, wherein said colored fine particles have a negative polarity. 3. The non-magnetic one-component developer according to claim 1, wherein the colored fine particles are produced by a polymerization method. 4. The organic fine particles are fine particles produced by a polymerization method, and the fine particles have a spherical shape and a particle diameter of 0.01.
The non-magnetic one-component developer according to any one of claims 1 to 3, which falls within a range of from 3 to 3 µm.