JP2536519B2 - Electrophotographic developing carrier - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a carrier used for an electrophotographic developer,
In particular, it relates to a carrier whose surface is coated with a plasma polymerized film.

2. Description of the Related Art A developer used for developing an electrostatic latent image in electrophotography is used as a two-component system composed of toner and carrier when the developing method is a cascade method or a magnetic brush method. In such a two-component developer, the toner is transferred and fixed after development to give a copied image, and is gradually consumed. Meanwhile, the carrier is recovered, recycled and used again with the toner.

When the carrier is recovered and recycled as described above, the toner particles adhere to the carrier particles, which deteriorates the characteristics of the carrier and further deteriorates the quality of the copied image.

In order to solve such a problem, a method of coating the surface of carrier particles with a resin such as a fluororesin is disclosed in, for example, JP-A-59-53857.

The resin-coated carrier particles are blown off while heating the carrier particles, and a solution for coating in which the resin to be coated is dissolved in a solvent is sprayed to the place where it becomes a powder cloud, and the solvent is dried ( It is generally obtained by a spray drying method), or a method of immersing carrier particles in a coating solution and removing the solvent by heating. As long as the coated carrier is produced by such a conventional method, it includes the problem that carrier agglomerates are formed depending on the spraying conditions and the blowing amount, and that the coated carrier material is deteriorated by heating. There is. In particular, coating of a powder containing a low melting point substance such as a binder type carrier cannot be achieved by a conventional method involving heating.

Further, the coated carrier produced by the spray drying method has a problem that the toner adheres to the uncoated portion because the coating on the surface of the carrier is not perfect and is a deviated coating film.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention Therefore, as a means for coating the surface of carrier particles with a uniform film, the present inventor forms a uniform hydrocarbon-based plasma polymerized film on the surface by exposing carrier particles to plasma. I thought about that. In actual experiments, the carrier could be coated with a strong and uniform film.

However, when the toner was actually mixed and stirred, the charge amount of the toner was not stable, and the image density varied during running.

An object of the present invention is to provide a carrier which is uniformly and uniformly coated on the entire surface of the particle without causing the above problems.

Means for Solving the Problems That is, the present invention relates to an electrophotographic developing carrier whose surface is coated with a hydrocarbon-based plasma polymerized film containing fluorine, silicon and a metal.

A feature of the present invention is that a plasma polymerization method is applied as a means for coating a carrier for an electrophotographic developer to obtain an electrophotographic developer with less aggregation and deterioration.

The carrier of the present invention has a structure in which the surface of powder such as glass beads, steel spheres, ferrite, and fine iron powder, which are commonly used as a carrier, is coated with a plasma polymerized film of an organic compound. Carriers obtained by coating ferrite with a plasma polymerized film are particularly excellent. The size of the carrier core material is 10 μm to 100 μm, particularly preferably 30 μm to 60 μm
Is.

The thickness of the plasma polymerized film coated on the carrier is several tens of Å
~ Tens of thousands Å is enough. Particularly preferably, 500 to 7,000Å
Is. According to the present invention, such a thin film can be coated uniformly and evenly. If the film thickness is less than 80Å, it will be worn during use as a developer, and if it is more than 15,000Å, it will be charged up and cannot be used as a developer.

The plasma-polymerized film that coats the carrier is configured to contain fluorine and silicon atoms. By doing so, the chargeability, electric resistance, wear resistance, water repellency and the like of the carrier can be improved. The total content of fluorine and silicon is 5 to 60% by weight of the total amount of the plasma polymerized film, especially 10 to 40%.
Weight percent is preferred. If the content is less than 5% by weight, the environment resistance (particularly moisture resistance) and the releasability of the spent toner are inferior, the rise of the charge amount is delayed, and the saturated charge amount after the rise is low. On the other hand, if it is more than 60% by weight, the film-forming property is deteriorated, and the formed film may have too high a charge amount to be used as a carrier.

Also, the plasma polymerized film that coats the carrier contains metal atoms. By doing so, the variation of the charge amount during printing is reduced, and a stable charge amount can be maintained at all times. Especially, the effect is remarkable at the beginning of stirring. That is, since the metal is contained, it is possible to prevent a decrease in the density during the first copy in the morning when the copying machine is mounted and the first copy after the long term use. Further, the charging property at high temperature and high humidity is stable, and uneven density is less likely to occur. The metal content is preferably 0.1 to 9% by weight, more preferably 1 to 4% by weight, based on the total amount of the plasma polymerized film. If the metal content is lower than 0.1% by weight, the above effect does not occur and 9% by weight
On the contrary, if it is higher, the charging ability is deteriorated.

The addition amount of these can be adjusted by selecting the raw material monomer or the plasma polymerization conditions.

A carrier containing a fluorine atom, a silicon atom and a metal atom in a plasma polymerized film is used as a fluorine- or silicon-based aliphatic hydrocarbon, a fluorine- or silicon-based aromatic hydrocarbon or a compound thereof and another aliphatic hydrocarbon in the plasma polymerization process. Alternatively, it can be obtained by using an aromatic hydrocarbon and a gas obtained by mixing these with at least one of a metal vapor, an organometallic gas, and a promotion gas of an organometallic compound.

Fluorine or silicon-based aliphatic hydrocarbons have a slower deposition rate than fluorine or silicon-based aromatic hydrocarbons, but are effective in forming a harder dense film. Further, the same effect can be obtained even when used for polymerization with an aromatic hydrocarbon or an aliphatic hydrocarbon containing no fluorine atom or silicon atom.

The plasma polymerized film according to the present invention is formed by plasma polymerizing a gas containing at least one organic compound containing a fluorine atom and / or a silicon atom in its structure.

This is because fluorine atoms or silicon atoms contained in the organic compound are efficiently added to the plasma polymerized film so that the film sufficiently functions.

The amount of fluorine atom silicon atoms or metal added to the plasma-polymerized film is, for example, pressure, substrate temperature, applied voltage, electrode interval, discharge frequency, gas flow rate, gas supply form, gas exhaust form, etc. It is greatly affected by plasma conditions. The feature of the present invention is that these atoms can be stably and efficiently added to the plasma polymerized film without being affected by such plasma conditions.

In the present invention, each compound for containing a fluorine atom, a silicon atom and a metal in the structure is subjected to a plasma polymerization reaction in a gas phase state, but the phase state does not necessarily have to be a gas phase at room temperature and atmospheric pressure. The liquid phase or the solid phase can be used as long as it can be vaporized through melting, evaporation, sublimation, etc. by heating, depressurization, or the like.

As the organic compound containing a fluorine atom that can be used in the present invention, vinyl fluoride, vinylidene fluoride and the like are used, and further, alkyl fluoride, aryl fluoride, fluorinated styrene, fluorohydrin, fluoroform and the like. Is used.

As the alkyl fluoride, for example, methyl fluoride, ethyl fluoride, propyl fluoride, butyl fluoride, amyl fluoride, hexyl fluoride, heptyl fluoride, octyl fluoride, nonyl fluoride, decyl fluoride, etc. are used. To be

For example, fluorostyrene is used as the aryl fluoride.

As the fluorohydrin, for example, ethylene fluorohydrin or the like is used.

Particularly preferred fluorine containing compound monomers may include those of the following structural formulas: (Hereinafter, the monomer having the above structural formula is referred to as F ₈ C ₅ MA.) Further, as the organic compound containing a silicon atom that can be used in the present invention, trichlorosilane, trichloromethylsilane, trichlorovinylsilane, trichloro-β-cyanoethyl Silane, trichloro-γ, γ, γ-trifluoropropylsilane, trichlorophenylsilane trichlorochlorophenylsilane, dichloromethylsilane, dichlorodimethylsilane, dichloromethylvinylsilane, dichlorovinylsilane, dichloromethyl-γ, γ, γ-trifluoropropylsilane , Dichlorodiphenylsilane, dichloromethylphenylsilane, chlorodimethylsilane, chlorotrimethylsilane, chlorodimethyl-t-butylsilane,
Chlorotriphenylsilane, tetramethylsilane, β-
(3,4-epoxycyclohexyl) ethyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, γ-methacryloxypropyltrimethoxysilane,
γ-chloropropyltrimethoxysilane, γ-mercaptopropyltrimethoxysilane, γ-aminopropyltrimethoxysilane, N- (β-aminoethyl) -γ-aminopropyltrimethoxysilane, N- (γ-aminoethyl)- γ-aminopropylmethyldimethoxysilane,
Phenylsilatrane, tetramethyldisiloxane, hexamethyldisiloxane, tetramethyldivinyldisiloxane, hexamethyldisilazane, N-trimethylsilylacetamide, N, O-bistrimethylsilylacetamide, etc., or silane, disilane, etc., which are inorganic gases, is there.

Further, as the compound containing a metal and metal, Al: Al (Oi-C 3 H 7) 3, (CH 3) 3 Al, (C 2 H 5) 3 Al, (i
_{-C 4 H 3) 3 Al,} AlCl 3 Ba: Ba (OC 2 H 5) 3 Ca: Ca (OC 2 H 5) 3 Fe: Fe (Oi-C 3 H 7) 3, (C 2 H 5) _{2 Fe, Fe (CO) 5} Ga: Ga (Oi-C 3 H 7) 3, (CH 3) 3 Ga, (C 2 H 5) 3 Ga, GaCl
_{3, GaBr 3 Ge: GeH 4} , GeCl 4, Ge (OC 2 H 5) 4, Ge (C 2 H 4) 4 Hf: Hf (Oi-C 3 H 7) 4 In: In (Oi-C 3 H _{7) 3, (C 2 H} 5) 3 In K: KOi-C 3 H 7 Li: LiOi-C 3 H 7 La: La (Oi-C 3 H 7) 4 Mg: Mg (OC 2 H 5) 2 _{, (C 2 H 5) 2} Mg Na: NaOi-C 3 H 7 Nb: Nb (OC 2 H 5) 5 Sb: Sb (OC 2 H 5) 3, SbCl 3, SbH 3 Sr: Sr (OCH 3) _{2 Ti: Ti (Oi-C} 3 H 7) 4, Ti (OC 4 H 9) 4, TiCl 4 Si: SiH 4, Si 2 H 6, (C 2 H 5) 3 SiH,: SiF 4, SiH 2 Cl ₂ , SiCl
_{4, Si (OCH 3) 4} , Si (OC 2 H 5) 4 Ta: Ta (OC 2 H 5) 5 V: VO (OC 2 H 5) 3, VO (Ot-C 4 H 9) 3 Y: _{Y (Oi-C 3 H 7} ) 3 Zn: Zn (OC 2 H 5) 2, (CH 3) 2 Zn, (C 2 H 5) 2 Zn Zr: Zr (Oi-C 3 H 7) 4 Sn: (CH ₃ ) ₄ Sn, (C ₂ H ₅ ) ₄ Sn, SnCl ₄ , Cd: (CH ₃ ) ₂ Cd Co: Co ₂ (CO) ₅ Cr: Cr (CO) ₆ Mn: Mn ₂ (CO) ₁₀ Mo: Mo (CO) ₆ , MoF ₆ , MoCl ₆ W: W (CO) ₆ , WCl ₆ , WF _{6 and the} like are used. In addition to these, vinyl metal monomers, metal phthalocyanines and the like can also be used.

Hydrocarbons that can be used with the above compounds include, for example, methane series hydrocarbons, ethylene series hydrocarbons, acetylene series hydrocarbons, aliphatic hydrocarbons such as alicyclic hydrocarbons, and aromatic hydrocarbons. .

Examples of methane hydrocarbons include methane, ethane, propane, butane, pentane, hexane, heptane, octane, nonane, decane, undecane, dodecane, tridecane, tetradecane, pentadecane, hexadecane, heptadecane, octadecane, nonadecane, eicosane, heneicosane. , Normal paraffin such as docosane, tricosane, tetracosane, pentacosane, hexacosane, heptacosane, octacosane, nonacosan, triacontane, dotriacontane, pentatriacontane, and isobutane, isopentane, neopentane, isohexane, neohexane, 2,3-dimethyl Butane, 2-methylhexane, 3-ethylpentane, 2,2
-Dimethylpentane, 2,4-dimethylpentane, 3,3-dimethylpentane, tributane, 2-methylheptane, 3
-Methylheptane, 2,2-dimethylhexane, 2,2,5-dimethylhexane, 2,2,3-trimethylpentane, 2,2,4-
Trimethylpentane, 2,3,3-trimethylpentane, 2,
Isoparaffins such as 3,4-trimethylpentane and isononane are used.

Examples of the ethylene chain hydrocarbon include ethylene, propylene, isobutylene, 1-butene, 2-butene, 1
-Pentene, 2-pentene, 2-methyl-1-butene,
3-methyl-1-butene, 2-methyl-2-butene, 1
-Hexene, tetramethylethylene, 1-heptene, 1
Olefins such as octene, 1-nonene, 1-decene, and diolefins such as allene, methylarene, butadiene, pentadiene, hexadiene, cyclopentadiene, and triolefins such as ocimene, alloocimene, myrcene, hexatriene, Etc. are used.

As the acetylene series hydrocarbon, for example, acetylene, methylacetylene, 1-butyne, 2-butyne, 1-
Pentin, 1-hexyne, 1-heptin, 1-octyne, 1-nonine, 1-decine and the like are used.

Examples of the alicyclic hydrocarbon include cyclopropane,
Cycloparaffins such as cyclobutane, cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, cyclodecane, cycloundecane, cyclododecane, cyclotridecane, cyclotetradecane, cyclopentadecane, cyclohexadecane, and cyclopropene, cyclobutene, cyclopentene, cyclohexene. , Cycloheptene, cyclooctene, cyclononene, cyclodecene, and other cycloolefins, and limonene, terbinolene, ferrandrene, silvestrene, zen, carene, pinene, bornylene, camphene, fenchen, cyclofenchen, tricyclene, bisabolen, zingiberen, curcumene , Humulene, kazinen sesquibenhen, selinen, cariophyllene, santalen, sedren Camphorene, Firokuraden, Podokarupuren, Millen, terpenes etc. and, steroids and the like are used.

Examples of aromatic hydrocarbons include benzene, toluene, xylene, hemimelitene, pseudocumene, mesitylene, prenitene, isodulene, durene, pentamethylbenzene, hexamethylbenzene, ethylbenzene, propylbenzene, cumene, styrene, biphenyl, terphenyl, diphenylmethane. , Triphenylmethane, dibenzyl, stilbene, indene, naphthalene, tetralin, anthracene, phenanthrene and the like are used.

The plasma-polymerized film-coated carrier of the present invention can be obtained by applying a plasma polymerization method using the above-mentioned fluorine-, silicon-, and metal-containing compound as a raw material. The plasma polymerization method is roughly classified into an internal electrode method (parallel plate type capacitive coupling) having a discharge electrode in a bell jar or a reaction tube and a method by inductive coupling by winding an electrode in a coil shape outside the bell jar. The coating method may be selected depending on the mode of the coating method. The specific polymerization apparatus is shown in FIG. In FIG. 1, both the parallel plate type plasma polymerization apparatus (the apparatus on the left in the figure) and the inductively coupled plasma polymerization apparatus (the apparatus on the right in the figure) are shown on the same stand (10), but in reality they are independent of each other. are doing.

In the parallel plate type plasma polymerization apparatus (left in FIG. 1), parallel plate type electrodes (3) are arranged opposite to each other in a reaction vessel (1). The electrodes are connected by a high frequency or low frequency power supply. Gaseous monomer is fed from the monomer inlet pipe (2)
It is introduced together with the carrier gas flowing from the carrier gas introduction pipe (23). Further, the liquid monomer is vaporized by a liquid vaporizer (not shown) and then similarly introduced through the monomer introduction pipe (2). The reaction is carried out in the reaction vessel (1) while the valve (9) is opened and closed and the pressure is reduced by the oil rotary pump (4). The degree of vacuum is read by the vacuum gauge (32). At that time, the gas discharged to the outside of the reaction system through the exhaust port (45) is removed by the cold trap (7) and the mechanical booster pump (5), and the powder is collected by the fine powder filter (6). Besides, a method of collecting by using magnetic force is also conceivable. Providing plasma polymerization on the surface of a carrier using this device is suitable for placing in a suitable container on the lower electrode (3) provided below the upper electrode (3) with the connecting wire (33) to the power supply. It is possible to carry out plasma polymerization while placing another carrier and vibrating or rolling the carrier by an appropriate method.

The inductively coupled plasma polymerization apparatus (right in FIG. 1) is different from the reaction vessel (1) in that the electrode part (3) is outside the reaction vessel (1) and the shape of the reaction vessel (1) is different due to the difference in the configuration. The configuration is basically the same as that of the parallel plate type plasma polymerization apparatus (left in FIG. 1). The inductively coupled plasma polymerization apparatus is particularly effective when applied to an aspect in which a plasma polymerization coating film is provided on the surface of a carrier while it is being dropped.

2 to 10 show further specific embodiments in which the plasma-polymerized film is provided on the carrier by using the above-mentioned apparatus. 3 to 10, the discharge electrode portion and the powder deposition portion are mainly shown for simplicity.

FIG. 2 shows that a plastic container (14) containing a carrier powder (13) is placed under a parallel plate electrode (12) provided in a bell jar (11) and brought into contact with a vibrating rod (15). ) Vibration is transmitted to the whole by a vibrator (16). This vibration causes the powder (13) in the plastic container (14) to start convection. The carrier powder (13) for generating plasma by supplying high-frequency power to the electrode (12) and polymerizing the monomer (organic compound) introduced into the bell jar (11) is constantly convected, so that the carrier powder (13) is degassed for a certain period of time. When placed in position, it is possible to coat the plasma polymerized film evenly on each of the powder particles (Development of low temperature plasma technology and surface treatment-application course for film coating, May 1985, 28.
Day).

FIG. 3 shows the vapor-deposited carrier powder (13) and the hopper (17).
A method of coating the surface of the carrier while moving it in the plasma obtained by the parallel plate type electrode (12) that is long in the vertical direction, and collecting the obtained coated carrier in the recovery dish (18) .

FIG. 4 shows a method in which carrier powder (13) is supplied from a hopper (17) to a transport belt (22) which also serves as an electrode, and plasma polymerization is performed on the belt while the belt is moving. The belt is vibrated by vibrators (21) attached to various places, and the carrier powder on the belt is coated while rotating on its own axis, so that the carrier powder is uniformly coated. The carrier coated in the discharge area is scraped by the blade (20) and collected in the collection dish (18). The method is particularly suitable for mass production.

FIG. 5 shows a method using an inductive coupling method in which a high frequency (13.56 MHz) is applied from the external electrode (12), and the principle is almost the same as in FIG. In this method, an inert gas is supplied from an inert gas supply pipe (23), and the inert gas is excited by applying high frequency to the external electrode (12), and the excited species are supplied from the monomer supply pipe (24). This is a method of supplying energy to the supplied monomers to coat carrier particles (13) falling from a hopper (17). According to this method, since plasma energy can be indirectly applied, there is an advantage that plasma damage is small,
Further, since the plasma generation part and the deposition part are separated, there is an advantage that a stable supply of plasma can be measured.

FIG. 6 shows an insulating dish (25) having a hemispherical recess.
The carrier powder (13) is supplied to the
A method of coating carrier powder by generating plasma between the electrodes (12) while vibrating by a vibrator composed of 7) and a permanent magnet (26) is shown. With this method, the powder (13) rolls up, down, left, and right while measuring the matching with the natural frequency of the dish (25) by the vibrator attached under the dish (25).
When the mode in which the powder convection is the strongest is set, the surface of the carrier powder can be evenly coated more effectively.

FIG. 7 shows the cascade method. The principle is the same as in FIG. The carrier powder (13) can be repeatedly coated by the cascade (28), and the coating film thickness can be controlled by the number of repetitions. This method is suitable for mass production.

FIG. 8 shows that a frying pan-shaped insulating dish (25) installed on the leaf spring (28) vibrates the leaf spring by an electromagnet (27) provided below the leaf spring (28). Here's how. The carrier powder (13) in the dish (25) is repelled by vibration. This method is to perform plasma polymerization coating on the powder surface while splashing the powder,
This method can also uniformly coat the surface of the carrier powder.

FIG. 9 shows a plasma polymerization coating method applying the principle of a mixer. In this method, a rotor (30) is rotated at a high speed by a motor (29), and carrier powder in a container (31) is rolled and floated while being uniformly coated.

FIG. 10 shows a plasma polymerization coating method using a speaker diaphragm. This method attaches the dish (25) to the speaker oscillator (21) and vibrates the speaker oscillator (21) according to the principle of the speaker, so that the carrier powder (13) in the dish (25) rotates. , Which promotes convection and vibration to uniformly coat the carrier powder with the plasma polymerized film.

Since the plasma polymerization coating method in the present invention is a low temperature and dry process, there is no concern that the substance to be coated will be deteriorated by heat or a solvent, or that it will aggregate.

When a thin film is uniformly coated on a carrier having a high glass transition point or melting point, for example, as shown in FIG.
A heater may be attached to the electrode having the shape shown in FIG. 6, FIG. 8, FIG. 9 or FIG. 10, and plasma polymerization may be performed while heating. When plasma polymerization is performed while rolling or floating the carrier with a vibrator or a splash plate, it is preferable to sufficiently heat the entire system in advance.

By coating a carrier with a plasma-polymerized film according to the present invention, the carrier itself can be improved in chargeability, charge stability, electric resistance, abrasion (spent toner) releasability, water repellency, and the like, and the carrier itself can be charged. Can be controlled.

The plasma-polymerized film-coated carrier of the present invention can be used together with a known toner and can be used in a known manner as a developer for electrophotography.

The developer using the plasma-polymerized film-coated carrier of the present invention has improved fluidity, and its chargeability, charge rising time, and repeated stability can be controlled.

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

Example 1 As a powder material, a ferrite carrier (particle size: 40 to 60 μm)
m), as coating material, isoprene ^* …… 30sccm Carbon tetrafluoride (CF ₄ ) …… 83sccm Silane (SiH ₄ ) …… 40sccm Titanium tetrachloride (TiCl ₄ ) ^＊ …… 21sccm (* ... vaporize liquid raw material Used) is introduced into the reaction vessel from each gas inlet,
A plasma polymerized film was deposited under the following conditions using the plasma polymerization apparatus shown in FIG. The obtained carrier is called carrier A.

Deposition time; 98 minutes Frequency; 13.56MHz power; 85W gas pressure; total 1.8Torr substrate; start at room temperature The thickness of the obtained carrier A is about 0.3μm and the size of the carrier core is about 48μm in average particle size. It was Using the obtained carrier A, (+) polar toner (average particle size) having the following composition
12.8 μm) was added to each of the polybins at a mixing ratio of 8%, and stirred to obtain a developer.

(+) Polar toner composition Styrene acrylic resin: 100 parts by weight (n; 12,400, w: 43,300, Tg: 62 ° C, softening point: 124 ° C) Carbon black: 5 parts by weight (MA # 8; manufactured by Mitsubishi Kasei) Antistatic preparation: 3 parts by weight (Bontron N-01; manufactured by Orient Chemical Industry Co., Ltd.) The developer obtained as described above is charged with a charge amount (Qf (μc / g)) and a charge rising time by a development process measuring instrument. Was measured. The schematic structure of the measuring instrument is shown in FIG. 14th
As shown in the figure, the developing device (3
5), a toner tester equipped with a charger (36) and a surface electrometer (37). First, a Mylar film (38) (having a known electrostatic capacity) is closely attached to a drum and attached, and after being uniformly charged by a charger, the surface potential V ₀ is measured. Next, the film is developed by rotating in reverse, and the surface potential V ₁ after development is measured. This potential difference (V ₀ −V ₁ ) corresponds to the charge amount of the developed toner. Next is the amount of toner deposited on the film (Dv mg / c
m ² ) is weighed, and the toner charge amount (Qfμc /
g) was asked. The results are shown in Fig. 11 and after 1 minute and 1
The charge amount of the toner after 0 minutes is summarized in Table 2.

Further, the obtained developer was used in actual copying, and the repeating characteristics of the toner charge amount were measured. The results are shown in FIG.

Next, the abrasion resistance was evaluated by an abrasion tester. A schematic configuration diagram of the wear tester is shown in FIG. That is, the same substance as in Example 1 was plasma-polymerized on an aluminum drum (80φ) (39) under the same conditions, and then a ferrite carrier having a particle diameter of 48 μm was added to the same styrene-acrylic resin used for toner preparation. Dispersed in 100 parts by weight to 20 parts by weight, plate-like (thickness 1
Using a weight (42), a sintered body (43) fired to 0 mm) is contacted at a contact angle (44) of 45 ° and a contact pressure (linear pressure) of about 5 g / mm, and a drum drive motor (40) is used. Drum at about 100 rpm
It was rotated for 10 hours. Table 2 shows the results of observing the degree of scratches on the film on the drum surface after the test and comparing with the Minolta limit sample (Minolta original).

In Table 2, the wearability is represented by ◯ (good), Δ (no problem), and × (bad).

Further, the same substance as the coating material used in Example 1 was plasma-polymerized on a glass plate under the same conditions to give a film thickness of about 11 μm. Table 2 shows the results of judgment by a JIS-standard pencil hardness tester.

In addition, changes with time of the charge amount of the toner and moisture resistance were examined, and the results are shown in Table 2 as ◯ (extremely good), Δ (normal), and x (bad). The results of measuring the electric resistance of the carrier under a constant load are also summarized in Table 2.

Comparative Example 1 A ferrite carrier was used as the powder material, and the surface of the ferrite carrier was coated with styrene acrylic and vinylidene fluoride to obtain a carrier. This carrier is called carrier C. The obtained characteristics are shown in Table 2 as in Example 1.

Comparative Example 2 Carrier B was prepared in the same manner as in Example 1 and its characteristics were evaluated. The same ferrite carrier as in Example 1 was used as the powder material, and the coating material was produced under the conditions shown in Table 1. The properties obtained were measured as in Example 1 and summarized in Table 2.

Comparative Example 3 An uncoated ferrite carrier was used as carrier D.
The characteristics were measured in the same manner as in Example 1 and summarized in Table 2.

The electric resistance of the carrier A of this example is higher than that of the non-coated carrier D of Comparative Example 3 by two to three orders of magnitude, so that
The problem of carrier development due to bias charge injection from the sleeve during development was also solved.

Further, the hardness of the carrier A of this example is higher than that of the carrier C of the comparative example 1, the film quality is smooth and there are no pinholes.
The adhesion to the core material was also good. Furthermore, Tg and Tm also increased because they were insoluble in the molten material.

The toner mixed with the carrier C of Comparative Example 1 showed a poor charging rise, and the charge amount decreased after running 30K sheets, but in this embodiment, the charging rise was good, and even if 60K sheets were raised, good charging was obtained. I was able to maintain the quantity.

Further, the charge amount of the toner mixed with the carrier A of this embodiment is more stable than that of the toner mixed with the carrier B of the comparative example 2 as shown in FIGS. The image density at the time of the running test conducted using the carrier A of the example was always stable.

The reason for this is not clear, but it is considered that the carrier itself can be prevented from being overcharged by containing a metal. That is, by coating the plasma polymerized film,
Even if the film thickness is thin, the carrier has high resistance. Therefore, it is considered that in the short term, the carrier repeats the charging process due to friction and the discharging process to the developing sleeve or the like due to overcharge, and the charge amount of the toner also fluctuates accordingly.
Therefore, by adding an appropriate amount of metal as in the present invention, charge-up of the carrier itself is prevented,
It is considered that the toner charge amount is also stable.

It should be noted that the present invention should not be limited to the above-mentioned embodiment, and was effective even when plasma irradiation was performed for an extremely short time. In this case, it is considered that the coating film uniformly and evenly coats the carrier particles in a discontinuous state, for example, as if the carrier particles were covered with a rope.

EFFECTS OF THE INVENTION The carrier of the present invention can not only improve the chargeability and abrasion resistance of the carrier itself, but also improve the water repellency and charge stability, and obtain a stable image density during start-up and running. You can

[Brief description of drawings]

FIG. 1 shows a plasma polymerization apparatus. 2 to 10 show one embodiment of manufacturing the carrier of the present invention. FIG. 11 shows the rising characteristics of the toner charge amount. FIG. 12 shows the repeated use characteristics of the toner charge amount. FIG. 13 shows a schematic structure of a wear tester. FIG. 14 shows a schematic configuration of the charge amount measuring device. The symbols in the figure are as follows. 1 ... Reaction container, 2 ... Monomer introduction tube, 3 ... Parallel plate type electrode, 4 ... Oil rotary pump, 5 ... Mechanical booster pump, 6 ... Fine powder filter, 7 ... Cold trap, 8 ... Refrigerant (eg, liquid nitrogen), 9 ... Valve, 10 ... Stand, 11 ... Bell jar, 12 ... Electrode, 13 ... Carrier powder, 14 ... Plastic container, 15 ... Vibration rod, 16 ... Vibrator, 17 ... Hopper, 18 ... Recovery tray, 19 ... RF power supply, 19 '... Counter electrode (belt-shaped) 20 ... Blade, 21 ... Transducer, 22 ... Transport belt, 23 ... Carrier gas (for example, inert gas) supply pipe, 24 ... Monomer supply pipe, 25 ... Plate, 26 ... Permanent magnet, 27 ... Electromagnet, 28 ... Leaf spring, 29 ... Motor, 30 ... Rotation Child, 31 ... Container, 32 ... Vacuum gauge, 33 ... Connecting line to power supply, 34 ... Drum, 35 ... Developer Position, 36 …… Charger, 37 …… Surface potential meter, 38 …… Mylar film, 39 …… Drum, 40 …… Drum drive motor, 41 …… Table, 42 …… Weight, 43 …… Sintered body, 44 ... Contact angle.

Claims (3)

(57) [Claims] 1. A carrier for electrophotographic development, the surface of which is coated with a hydrocarbon-based plasma polymerized film containing fluorine, silicon and a metal. 2. The carrier for electrophotographic development according to claim 1, wherein the total amount of fluorine and silicon contained in the hydrocarbon-based plasma polymerized film is 5 to 60% by weight. 3. The carrier for electrophotographic development according to claim 1, wherein the amount of metal contained in the hydrocarbon-based plasma polymerized film is 0.1 to 20% by weight.