JPH0286A - Electrophotographic copying device - Google Patents

Abstract

PURPOSE:To properly perform cleaning a photosensitive body by coating a carrier contained in a magnetic brush cleaning part with a material of low surface energy on which a conductive material is dispersed. CONSTITUTION:A magnetic brush cleaning method is employed with respect to the cleaning part 7, and a magnetic carrier is contained as a cleaning powder. Then, a magnet is contained inside a cleaning roller 71 on which a positive or a negative bias is impressed, and the cleaning agent is held on the roller. Then residual toner is electrostatically attracted to the cleaning agent, carried from pump-up rollers 72 and 73 to a residual toner recovery roller 74, and removed outside through a recovery blade 76. Then, the sticking of spent toner to the magnetic carrier can be prevented since the surface of the cleaning agent in the cleaning part 7 is coated with the material of low surface energy on which the conductive material is dispersed, that is, with the material of high peeling property.

Description

Detailed Description of the Invention [Technical Field] The present invention relates to an electrophotographic copying device (including an electrostatic copying device), and more specifically, the present invention relates to an electrophotographic copying device (including an electrostatic copying device). ) The present invention relates to an electrophotographic copying apparatus in which a magnetic brush cleaning device is disposed in a cleaning section for removing residual toner on the surface.

[Prior art]

As shown in FIG. 1, an electrophotographic copying apparatus generally includes an organic or inorganic photoreceptor 1 (this is not limited to a drum shape but may also be a belt shape), and a charger 2;
It is comprised of an optical system 3, a developing section 4, a transfer charger 5, a separation charger 6, and a cleaning section 7. The transfer charger 5 is used to transfer the toner image on the photoconductor 1 onto a transfer paper 8 such as plain paper, and the separation charger 6 is used to separate the transfer paper 8 carrying the toner image from the surface of the photoconductor 1. In the drawing,
9 indicates a separation claw.

By the way, either a dry development method or a wet development method (including a semi-dry development method) is used to visualize an electrostatic charge image, but the former is advantageous in terms of obtaining copies in a dry state. Therefore, the dry developing method is currently the mainstream.

Dry development method uses a one-component developer (consisting only of toner)
There are two main types: those that use a two-component developer (consisting of a carrier and a toner), and those that use a two-component developer (consisting of a carrier and a toner). In any case,
Ideally, all toner images made visible by such a developer would be transferred to transfer paper, but in reality, toner that could not be completely transferred remains on the photoreceptor.
This residual toner must be removed by a cleaning device.

The remaining toner (untransferred toner) is generally cleaned using (1) a fur brush, (2) a blade, or (3) a magnetic brush. However, the fur brush method requires a large cleaning device and is prone to filming on the photoreceptor. Furthermore, the blade method has drawbacks such as the fact that it tends to damage the photoreceptor. In contrast, cleaning using a magnetic brush method has been studied, for example, in Japanese Patent Application Laid-Open No. 102273/1984, but although the deficiencies of (1) and (2) above are eliminated, the conventional magnetic brush cleaning device However, this method has the disadvantage that long-term cleaning is not guaranteed.

〔the purpose〕

A first object of the present invention is to provide an electrophotographic copying apparatus that uses a two-component dry developer and is equipped with a magnetic brush cleaning section, which allows residual toner to be removed well and which can be cleaned for a long period of time. It provides: A second object of the present invention is to provide an electrophotographic copying apparatus that can produce a large number of high quality copies.

〔composition〕

In the present invention, an electrostatic charge image is formed on a photoconductor, this is made into a latent image using a two-component developer, and after this toner image is transferred to a transfer paper, the toner remaining on the surface of the photoconductor is removed by a magnetic brush cleaning section. In the electrophotographic copying apparatus, the carrier housed in the magnetic brush cleaning section is characterized in that its surface is coated with a low surface energy material in which a conductive material is dispersed.

By the way, the present inventors have discovered that when using a two-component developer, by coating the surface of the carrier (cleaning agent) in the cleaning section with a low surface energy material in which a conductive material is dispersed, residual toner can be removed by the magnetic brush. It is easier to transfer to the carrier (cleaning carrier) in the cleaning section, and residual toner once attached to this cleaning carrier is easier to separate from the cleaning carrier in the magnetic brush cleaning section, resulting in long-term cleaning. Confirmed. The present invention has been made based on this.

In the following, the device according to the invention will be explained in more detail in connection with the copying process, with reference to the accompanying drawing (FIG. 1).

First, the surface of the photoreceptor (inorganic photoreceptor, organic photoreceptor) 1 is uniformly charged positively or negatively by the charger 2 . Whether the photoreceptor is positively charged or negatively charged is selected depending on the type (property) of the photoreceptor 1. For example, if the photoreceptor is Se-based, it will be positively charged. Image exposure is performed on this by the optical system 3 to form an electrostatic charge image, and this electrostatic charge image is visualized in the developing section 4.

The developing section 4 stores a two-component developer consisting of a carrier (magnetic carrier) and toner. The developer is magnet 4
The photoreceptor 1 is held on a developing sleeve 41 containing a photoreceptor 11.
Develop the electrostatic charge image.

Since only the developer toner is consumed each time development is performed, a sensor 42 detects the toner concentration of the developer and new developer toner is supplied so that the toner concentration is always constant. 43 is a paddle wheel for stirring the developer. Note that a bias may be applied to the developing sleeve 41 if necessary.

The visible image (toner image) is transferred to the transfer paper 8 by the transfer charger 5.
The transfer paper 8 is separated from the photoreceptor 1 by the separation charger 6 and the separation claw 9 and sent to the fixing process.

As mentioned earlier, not all of the toner forming a visible image on the photoreceptor 1 during transfer is transferred to the transfer paper 8;
A portion remains on the photoreceptor 1. Then, a means is adopted in which this residual toner is removed by a cleaning section 7.

The cleaning section 7 in the apparatus of the present invention employs a magnetic brush cleaning method, and contains a magnetic carrier (cleaning carrier) as a cleaning agent. The cleaning roller 71 with a built-in magnet (not shown) has a voltage of 100 to 500 V of positive or negative polarity.
A certain amount of bias is applied, and this cleaning roller 7
A cleaning agent is held on the magnet by the magnet. Here, the polarity of the bias applied to the cleaning roller 71 is opposite to the polarity of the toner in the two-component developer.

Remaining toner is a cleaning agent (cleaning carrier)
The liquid is electrostatically attracted to the cleaning agent and transferred to the pumping rollers 72 to 73 together with the cleaning agent. Pumping roller 73
A residual toner collecting roller 74 to which a bias of the same polarity as that of the cleaning roller 71 is applied is arranged behind the cleaning roller 71, and only residual toner is transferred to this collecting roller 74.

It is desirable that the bias applied to the collection roller 74 be relatively higher than the bias applied to the cleaning roller, and a range of 200 to 800 V is appropriate.

Immediately after residual toner is transferred from the pumping roller 73 to the collection roller 74, the cleaning carrier is scraped off by a cleaning soufflage lever 75 that is in contact with the pumping roller 73, and returned to the surface of the cleaning roller 71 again.

On the other hand, the residual toner transferred to the collection roller 74 is scraped off by a collection blade 76 that is in contact with the collection roller 74.
It is taken out of the cleaning section 7 by a discharge screw 77.

If necessary, it is used as a toner in a two-component developer. Collection roller 74 cleaned by collection blade 76
is used for the next collection of residual toner. Note that it is unavoidable that the cleaning agent (cleaning carrier) that falls onto the cleaning roller 71 and is circulated so as to contribute to the recovery of residual toner contains some residual toner; is in the range of at most 2% by weight.

In the apparatus of the present invention, such a series of cycles of copying steps and cleaning steps are repeated, but when the photoreceptor 1 is uniformly charged by the charger 2, there is no residual toner on the surface of the photoreceptor. Therefore, photoreceptor 1
Uniform charging is guaranteed.

Cleaning carrier used in cleaning section 7 (
Since the surface of the cleaning agent (cleaning agent) is coated with a low surface energy material (i.e., a material with excellent releasability) in which a conductive material is dispersed, it is possible to prevent the spent toner from adhering to the cleaning carrier. As a result, a constant charge (Q/M) can be obtained on the cleaning carrier over a long period of time, so that cleaning defects do not occur on the image and the photoreceptor 1 can be cleaned satisfactorily.

Generally, the cleaning carrier has a lower residual toner concentration than the developing carrier, and as mentioned above, it is used at most 2% by weight, but usually about 1% by weight (the toner concentration in the developing section 4 is 2 to 7% by weight). Therefore, in the cleaning section 7, there are many opportunities for cleaning carriers to rub against each other, and in particular, toner tends to fuse easily, and spent toner tends to adhere to cleaning carriers. Therefore, in the case of a non-coated cleaning carrier, spent toner adheres to the carrier at an early stage, resulting in a decrease in Q/M and a significant deterioration in image quality due to insufficient cleaning.

On the other hand, the cleaning carrier according to the present invention is
Because its surface is coated with a material that has good releasability,
Not only does it not have the disadvantages of the non-coated cleaning carrier, but also the cleaning carrier itself has good fluidity, and the cleaning agent is pumped up from the cleaning roller 71 to the rollers 72 and 73.
You can move smoothly to Then, it is guaranteed that the toner is completely fed to the toner collection roller 74, and good leaning performance can be maintained at all times.

The cleaning agent (cleaning carrier) in the present invention consists of a carrier core material coated with a low surface energy material in which a conductive material is dispersed on the surface.
As the core material here, conventionally known iron, magnetite, ferrite, etc. can be used. The particle size of this core material is suitably 10 to 1000 .mu.m, preferably 30 to 500 .mu.m.

In addition, low surface energy substances that coat the surface of this core material include thermoplastic resins containing polyolefins, such as polyethylene, polypropylene, chlorinated polyethylene, and chlorosulfonated polyethylene; polyvinyl and polyvinylidene, such as polystyrene, polymethyl methacrylate, and polyacrylonitrile. , polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether and polyvinyl ketone; vinyl chloride-vinyl acetate copolymer, styrene-acrylic acid copolymer; silicone resin;
Fluorocarbon, polytetrafluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, polychlorotrifluoroethylene; polyamide resin; polyester (e.g. polyethylene terephthalate); polyurethane; polycarbonate, amino resin (e.g. urea-formaldehyde resin); epoxy resin, etc. Can be mentioned. Particularly preferred are silicone resins and fluororesins.

The silicone resin here may be any conventionally known silicone resin, including straight silicone and alkyd resins consisting only of organosiloxane bonds,
Examples include silicone resins modified with polyester, epoxy, urethane, etc.

(In the formula, R1 is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a phenyl group, R2 and R3 are a hydroxyl group,
Alkyl group having 1 to 4 carbon atoms, alkoxyl group having 1 to 4 carbon atoms, phenyl group, phenoxy group, 2 carbon atoms
-4 alkenyl group, alkenyloxy group having 2 to 4 carbon atoms, hydroxyl group, carboxyl group, ethylene oxide group, glycidyl group or Te15 group, carboxyl group, alkyl group having 1 to 4 carbon atoms,
Alkoxyl group having 1 to 4 carbon atoms, 2 to 4 carbon atoms
alkenyl groups, alkenyloxy groups having 2 to 4 carbon atoms, phenyl groups, and phenoxy groups. k, Q, m, n
, o, and p represent integers of 1 or more. ) In addition to unsubstituted substituents, each of the above substituents includes, for example, an amino group,
Hydroxyl group, carboxyl group.

It may have a substituent such as a mercapto group, an alkyl group, a phenyl group, an ethylene oxide group, a glycidyl group, or a halogen atom.

For example, commercially available straight silicone resins include KR271, KR255, and KR251 manufactured by Shin-Etsu Chemical Co., Ltd., and 5R2400 and 5R2406 manufactured by Toray Silicone Co., Ltd., and modified silicone resins include KR206 (alkyd modified) and KR3093 (manufactured by Shin-Etsu Chemical Co., Ltd.). acrylic modification),
E 5100IN (epoxy modified), Toray Silicone S R2115 (epoxy modified), 5R2110
(alkyd modification), etc.

In addition, the fluororesins used here include polytetrafluoroethylene (PTFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVDF), and tetrafluoroethylene. Examples include nytylene-perfluoroalkyl vinyl ether copolymer (PFA), and in addition to these, it is also possible to use a fluororesin in which a filler is dispersed.

In the present invention, the surface layer of the cleaning agent (the above-mentioned silicone resin,
An appropriate amount of conductive material is dispersed in the surface layer made of a low surface energy material such as fluororesin.

Examples of typical conductive substances (conductive materials) - white ones and carbon - are as shown in (a) and (b) below.

(a) White conductive material ECT 52 (TiOx type) KV400
(TiO2-based) E CR-72 (T x OZ
system) ECTR-82 (TiO2 system) 500W (TiO2 system) 300W (TiO2 system) S-1 (Ti02 system) W-1 (Sn○2 system) 23 K (ZnO) Conductive zinc white Nα1 (ZnO) Conductive Zinc white Nα2 (ZnO) W-10 (TiO2-based) Dentol WK-100 (conductive fiber) Dentol Reni-200 (conductive fiber) Dentol 1llK-300 (
Conductive fiber) MEC300 (Sn○2 type) MEC500 (Sn○2 type) (b) Carbon Biack Pearls 2000. VIJLCA
NXC-72 Titanium Industries Co., Ltd. Titanium Industries Co., Ltd. Tamaki Titanium Industries Co., Ltd. Titanium Industries Co., Ltd. Manufactured by 6 Hara Sangyo Co., Ltd. Made by Mitsubishi Metals Co., Ltd. Hibaku Kagaku Co., Ltd. Hibaku Kagaku Co., Ltd. Teikoku Kako Co., Ltd. Teikoku Kako Co. (manufactured by Cabot) Denka black granules, Denka black powder (Deki Kagaku Kogyo Co., Ltd.) C0NDUCTEX975. C0NDU
CTEX SC (manufactured by: lO Nvia Carbon) These conductive materials (conductive substances) have a particle size of 0. Old ~ 3 μm preferably 0
．． 0.05 to 2.0 μm is suitable, and the amount added is 0.05 to 2.0 μm per 100 parts by weight of the low surface energy material.
A suitable amount is 1 to 100 parts by weight, preferably 0.5 to 80 parts by weight. Note that these conductive materials may be used alone or in combination of two or more.

In the present invention, the Q/M value of the cleaning agent is increased as soon as the cleaning agent and the toner come into contact (i.e., the residual toner is easily transferred to the cleaning agent as soon as the cleaning agent comes into contact with the toner). ) with the intention of providing good cleaning properties.
A low surface energy material layer (covered with r
It is desirable to contain an appropriate amount of a triboelectric charge imparting substance dispersed in layer II).

For example, for negatively charged toner, a substance that shows positive chargeability is dispersed in the cleaning carrier coating layer, and for positively charged toner, a substance that shows negative chargeability is dispersed in the cleaning carrier coating layer. to be dispersed.

Such triboelectric charging substances include various dyes and pigments, as well as functional groups such as halogen, epoxy group, hydroxyl group, etc.
Examples include resins containing amino groups, phenyl groups, carboxyl groups, etc.; aliphatic metal salts; complex compounds; complex salts; metal salts of salicylic acid or salicylic acid derivatives; some of them are as follows.

(1) Nigrosine dye (especially azine oil-soluble dye with C, 1
, 5olvent Black 5. C,1,5olv
(preferably the one included in ent Black 7). As an example of C,1,5o1vent Black 5, Orient 5pirit Black AB (manufactured by Orient Chemical Co., Ltd.) Orient 5pirit Bla
ck SB (manufactured by Orient Chemical Co., Ltd.) Spirit Bl
ack No350 (manufactured by Jumin Kagakusha) Spiri
t Black No900 (manufactured by Sumima Kagaku Co., Ltd.) C
,1,5olvent Black 7 as an example of N
igrosine Ba5e GB (Bayer
) Nigrosine Ba5e LK (B
(manufactured by ASF), etc.

(2) Xanthene dyes (especially C, 1, Pigment
Red 81°C, 1,5olvent Red 49
).

This includes C, 1, 0a as an example of PiHment Red 81.
inichi Fast Pink GX Toner
(Manufactured by Dainichiseika Co., Ltd.) Symulex Rhodamine
Y, Toner F (manufactured by Dainippon Ink Co., Ltd.) Rhoda
mine Y Toner (manufactured by Dainippon Ink Co., Ltd.) R
ose Toner (manufactured by Tokyo Shikizai Co., Ltd.) Ul
tra Rose R (manufactured by Toyo Ink Co., Ltd.) Sanyo
Fanal Rose (manufactured by Yamaba Color Co., Ltd.) Fast
Rose Lake FG (manufactured by Tokyo Ink Co., Ltd.) F
anal Pink B (manufactured by BASF) Halopont Pink 2BM (D u
p company) Fastel Pink B 5upra
(Manufactured by ICI) C,1,5olvent Red 4
9 as an example of Rhodamine B Ba5e
(Manufactured by Susumu Kagakusha) Solvent Rhodami
ne B Cone (manufactured by Ikeda Chemical Co., Ltd.).

(3) Resin a containing an amino group (in the formula, R', R7, and R8 are hydrogen or have 1 to 5 carbon atoms)
These alkyl groups may be the same or different. D is carbon or an alkylene group having 1 to 5 hydrogen atoms. ) or copolymer with styrene [dimethylaminoethyl methacrylate-styrene copolymer (polymerization molar ratio:
10/90 or 15/85)] (4) Quaternary ammonium salt ~ 17 aromatic hydrocarbon or aliphatic hydrocarbon,
o represents an anion. Examples of anions include halides, phosphates, sulfonic acid groups, nitrates, etc., particularly halides, and Xo represents an anion. Examples of anions include halides, phosphates, sulfonic acid groups, and nitrates, with halides being particularly preferred. ) Examples of this include tetramethylphenylammonium chloride, tetrabutylammonium chloride, tetrabutylammonium bromide, and the like.

(5) Total complex salt dye represented by the following general formula (in the formula R'
, R'', R11 and R12 are 3 carbon atoms (however, x, y
, z represents hydrogen, halogen, carboxyl group, hydroxyl group, nitrilo group, sulfone group, or sulfamide group, and A9 represents H, Na or an aliphatic ammonium cation. ) Specific examples of this are the following structural formulas (5-1) to (5-6
) can be given.

Structural formula (5-1) Structural formula (5-3) (blank below) Structural formula (5-2) Structural formula (S-a) Structural formula (5-'6) Hυ (6) Salicylic acid metal salt or salicylic acid derivative metal salt (wherein Rld, RL4 and Rlg are hydrogen or an alkyl group having 1 to 10 carbon atoms is preferably an allyl group).

R13, R14 and RIS may be the same or different at the same time. M is Zn, Ni, Co, Pb and Cr
Any metal selected from ) The metal salt represented by this general formula is CLARK.

J, L., KaO, H. (1948) J., Amer, Che.
m, Sac 70, 2151. For example, zinc is obtained by adding 2 moles of sodium salicylic acid salt (including sodium salts of salicylic acid derivatives) and 1 mole of zinc chloride to a solvent, mixing, heating and stirring. Metal salts other than zinc salts can also be produced according to the above method.

The appropriate amount of these triboelectric charging substances added is 0.1 to 60 parts by weight, preferably 0.5 to 40 parts by weight, per 100 parts by weight of the coating resin (low surface energy substance). In addition,
These triboelectric charge imparting substances may be used alone or in combination of two or more.

When the above-mentioned conductive material and triboelectric charge imparting substance are used together, the cleaning agent (cleaning carrier) increases the cleaning electric field and immediately raises LQ/M, allowing good cleaning to be carried out. The total amount of the conductive material and the triboelectric charging substance is suitably 0.1 to 100 parts by weight, preferably 0.5 to 80 parts by weight, based on 100 parts by weight of the coating resin (low surface energy material).

Although the description so far has been made regarding an apparatus using an electrophotographic photoreceptor, it goes without saying that an electrostatic recording member may be used instead of the photoreceptor.

Next, examples and comparative examples will be shown. Parts here are by weight.

In the example, an average particle diameter of about 100 μI was used as a carrier for a component-based developer.
Steel beads (Microshot 5F manufactured by Shinra Plater)
-100) was prepared.

Further, a mixture of the following formulation was kneaded under heating on two rolls, cooled, and then crushed and classified to produce a toner for a two-component developer having a particle size of 5 to 20 μm.

Polystyrene (Esso D-125)
100 parts carbon black (Mitsubishi Kasei #44)
10 parts of these carriers and 3 parts of toner
．． A two-component developer was prepared by mixing 0 parts. Note that the toner charge M due to the blow-off method in this developer
(Q/M) was -24 μc/g.

On the other hand, the cleaning carrier (cleaning agent) is
First, toluene 150
A coating liquid consisting of 0 parts was prepared, and 5 kg of oxidized iron powder with an average particle size of 100 μI was placed in a rotating disc type fluidized bed particle coating device, and the coating liquid was sprayed on a fluidized object while heating at 80 ° C. The coated material was taken out from the coating device and placed in a constant temperature bath for 20 minutes.
It was made by heating at 0° C. for 2 hours to cure the silicone film.

These two-component developer and cleaning agent are applied to the copying machine shown in FIG. +250v bias for 71,
A bias of +300V was applied to the collection roller 74)
was set to obtain copies at a rate of 30 sheets per minute, and the toner consumed in the developing section 4 was replenished. The results of this running test are summarized in Table 1.

Examples 2 to 6 Silicone resin of Example 1 (Toray Silicone 5R24
06) with other silicone resin [(Example 2: KR2
71, Example 3: KR251 (all manufactured by Shin-Etsu Chemical), Example 4: 5R2115, Example 5: 5
A cleaning agent was prepared in exactly the same manner as in Example 1, except that R2400 (both manufactured by Toray Silicone Co., Ltd.) and Example 6: KR3093 (manufactured by Shin-Etsu Chemical Co., Ltd.) were used.
We also created a two-component developer. Using these, the same running test as in Example 1 was conducted and the results are summarized in Table 1.

Table 1 (Note 1) Measure the density of the image using a Macbeth densitometer (RD-514) A tape was pasted onto white paper of Type 6200 (Ricoh Co., Ltd. copy paper) and the density was measured using a Macbeth densitometer. same as below.

Example 7 The carrier of Example 1 (steel beads with an average particle diameter of about 100 μm) was prepared as a carrier for a two-component developer.

On the other hand, a mixture of the following formulation was kneaded under heat on two roll mills, cooled, and then pulverized and classified to produce a toner for a two-component developer having a particle size of 5 to 20 μm.

Polystyrene (Esso D-125)
100 parts Dye (Special Black SB manufactured by Orient Chemical Co., Ltd.) 5 parts Carbon black (#44 manufactured by Mitsubishi Chemical Corporation) 1
A two-component developer was prepared by mixing 100 parts of these carriers and 3.0 parts of toner. The Q/M in this developer was measured to be 20 μc/g.

On the other hand, the cleaning carrier (cleaning agent) is
First, 250 parts of polytetrafluoroethylene (solid content 60%: D-1, manufactured by Daikin Industries, Ltd.) Ketchen Black EC-DJ500 (manufactured by Lion Akzo) 5
1% aqueous solution of partially fluorinated surfactant (FC-134, manufactured by 3M Corporation)
A coating solution consisting of 1500 parts was prepared, and the average particle size was 100μ in a rotating disk type fluidized bed particle coating device.
The above coating solution was sprayed onto a fluidized object containing 5 kg of oxidized iron powder of I, heated at 80°C, and the coated material was taken out of the coating equipment and placed in a constant temperature bath at 350°C for 2 hours. It was made by heating to harden the fluorine film.

These two-component developer and cleaning carrier (cleaning agent) are applied to the copying machine shown in Fig. 1 (an organic photoreceptor is used as the photoreceptor, and the surface potential of the photoreceptor 1 is uniformly charged to 1600 V). A bias of -250 V was applied to the cleaning roller 71 and a bias of -300 V was applied to the collection roller 74), and copies were made at a rate of 30 sheets per minute, and the toner consumed in the developing section 4 was reduced. Replenishment was carried out. The results of this running test are summarized in Table 2.

Examples 8 to 13 The fluororesin (D-1, manufactured by Daikin Industries, Ltd.) of Example 7 was mixed with other fluororesins [Example 8: TEF (851-214°, manufactured by DuPont), Example 9: TEF and bronze. (MG-3060, manufactured by Daikin Industries, Ltd.), Example 10
: TEF (856-204, manufactured by DuPont), Example 11: Epoxy modified Teflon enamel (S 954-
Example 12: Teflon S (manufactured by DuPont), Example 13: Tetrafluoroethylene-hexafluoropropylene copolymer (NO-1, manufactured by Daikin)] A cleaning agent was prepared in exactly the same manner as in Example 7, and a two-component developer was also produced. Using these, the same running test as in Example 7 was conducted and the results are summarized in Table 2.

(Leaving space below) Table 2 Examples 14 to 19 The conductive substances in the composition of the cleaning carrier liquid used in Example 1 were respectively [Example 14: 30 parts of ECT52 (manufactured by Titanium Kogyo Co., Ltd.), Example 15: KET52]. Chain Black EC-DJ600 (manufactured by Lion Akzo) 5 parts, Example 16: W-1 (manufactured by Mitsubishi Metals) 30 parts, Example 17
: 30 parts of 23K (manufactured by Hakusui Chemical Co., Ltd.), Example 18: 30 parts of conductive zinc white Nα1 (manufactured by Honjo Chemical Co., Ltd.), Example 1
9: VULCAN XC-72 (manufactured by Cabot)
A cleaning agent was prepared in exactly the same manner as in Example 1, except that 5 parts were changed, and the same two-component developer as in Example 7 was also prepared. Using this, the same running test as in Example 1 was conducted and the results are summarized in Table 3.

In Examples 14 to 19, 250 parts of polytetrafluoroethylene (D-1) was used as the cleaning carrier liquid instead of 100 parts of silicone resin (Toray Silicone 5R2405), and the toner of Example 7 was used. When a running test similar to that of Example 7 was conducted using the following, results similar to those of Examples 12 to 17 were observed.

(Leaving space below) Table 3 Examples 20 to 23 In addition to the composition of the cleaning carrier liquid used in Example 1, a triboelectrically charged (plus) substance [Example 20: Polyamide S-4011A (resin containing an amino group, Sanyo (manufactured by Kasei Co., Ltd.), Example 21: Rhodamine yellow toner (xanthene dye, manufactured by Dainippon Ink & Chemicals Co., Ltd.), Example 2
2: Styrene-dimethylaminoethyl methacrylate copolymer (polymerization molar ratio 90/10), Example 23: H
alopont Pink28M (xanthene dye,
DuPont), Example 24: Special Black SB
Glossine dye, manufactured by Orient Chemical Co., Ltd.), Example 25
: Nigrosine base LK with grosine dye, BASF
A cleaning carrier liquid was prepared in exactly the same manner as in Example 1, except that 10 parts of the cleaning carrier liquid was added (manufactured by Co., Ltd.), and a two-component developer was also prepared. Using this, the same running test as in Example 1 was conducted and the results are summarized in Table 4.

Examples 26 to 31 In addition to the composition of the cleaning carrier liquid used in Example 7, a triboelectrically charged (negative) substance was added [Example 26: Enpara 70 (chlorinated paraffin, manufactured by Ajinomoto Co., Ltd.), Example 27:
Polyester resin (382A, manufactured by Kao Soap Co., Ltd.), Example 28: BONTRON-E82 (3,5-ditertiary-butyl Cr complex, manufactured by Orient Chemical Co., Ltd.), Example 29: N1honthrene Red Viol
et RHD/P (thioindigo dye, manufactured by Sumima Kagaku Co., Ltd.), Example 30: Deep Red Viole
t (thioindigo pigment.

(manufactured by Toyo Ink Co., Ltd.), Example 31: Sumitone
A cleaning carrier liquid was prepared in exactly the same manner as in Example 7, except that 10 parts of Fast Red Violet RH (thioindigo pigment, manufactured by Sumima Kagaku Co., Ltd.) was added.

We created a cleaning agent and a two-component developer. Using this, the same running test as in Example 7 was conducted and the results are summarized in Table 4.

(Leaving space below) Table 4 Examples 32 to 44 The conductive substances in the composition of the cleaning carrier liquid used in Example 7 were respectively [Example 32: 30 parts of ECT52 (manufactured by Titanium Kogyo Co., Ltd.), Example 33: KET52]. Chain Black EC-DJ600 (manufactured by Lion Akzo) 5 parts, Example 34: W-1 (manufactured by Mitsubishi Metals) 30 parts, Example 35: 23K (manufactured by Hakusui Chemical Co., Ltd.) 30 parts, Example 36: Conductive Zinc White No. 1 (manufactured by Honjo Chemical Co., Ltd.) 30 parts, Example 37: VULCAN Black SB, Orient Chemical Co., Ltd.) 5 parts, Example 39: Nigrosine dye (Spirit Black Nα850, Sumima Kagaku Co., Ltd.) 5 parts, Example 40: Basic dye (Simulex Rhodamine'l Toner F, Dainippon Ink Chemical) ) 5 parts, Example 41: Basic dye (rose toner, manufactured by Tokyo Shikizai Co., Ltd.) 5 parts, Example 42: 5 parts of tetrabutylammonium chloride, Example 43: 5 parts of tetramethylphenylammonium chloride, Implementation Example 44: Styrene-dimethylaminoethyl methacrylate copolymer 5 A cleaning carrier was prepared in exactly the same manner as in Example 7, except that the above steps were added, and a two-component developer was also prepared. Using these, the same running test as in Example 7 was conducted and the results are summarized in Table 5.

(Margins below) Table Examples 45 to 50 Same as Example 1 except that the conductive substance in the composition of the cleaning carrier liquid used in Example 1 was changed and a triboelectric charging (plus) substance was added as shown below. In exactly the same manner, a cleaning carrier liquid was prepared, a cleaning agent was prepared, and a two-component developer was also prepared. Using this, the same running test as in Example 1 was conducted and the results are summarized in Table 6.

Examples 51 to 68 A cleaning carrier liquid was prepared in exactly the same manner as in Example 7, except that a conductive substance and a triboelectrically charged (negative) substance were added to the composition of the cleaning carrier liquid used in Example 7 as shown below. We also created a cleaning agent and a two-component developer.

Table 6 shows the results of a running test conducted exactly the same as in Example 7 using these materials.

Comparative Example A running test was conducted in the same manner as in Example 1 or 7, except that the cleaning carrier was not coated with a low surface energy material in which a conductive material was dispersed.
The copy image density at the start is 1.28,500th copy 0.
7, no image was obtained on the 100,000th sheet, and the density of the cleaning image on the photoreceptor was 0.07.5 at the start.
It was 1.20 at the 00th sheet, and the stain on the surface of the photoreceptor was significant at the 100,000th sheet.

〔effect〕

As is clear from the description of the embodiments, according to the photographing apparatus of the present invention, even when copying 100,000 sheets, there is no image stain and high-quality copies can be obtained. Furthermore, the surface of the photoreceptor after cleaning was visually observed to be extremely clean.

On the other hand, when using a copying machine (comparative example) in which the electrical resistance value of the cleaning carrier was larger than that of the two-component developer carrier, dirt was observed on the photoreceptor surface after about 1,000 copies were made. Occurrence of poor cleaning was observed.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram of an electrophotographic copying apparatus according to the present invention. 1... Photoreceptor 3... Optical system 5... Transfer charger 7... Cleaning section 9... Separation claw 41... Magnet 43... Paddle wheel 72.73... Pumping roller 75 ... Cleaning souffle lever 76 ... Collection blade 77 ... Ejection screw 2 ... Charger 4 ... Developing section 6 ... Separation charger 8 ... Transfer paper 41 ... Developing sleeve 42 ...・Sensor 71...Cleaning roller 74...Recovery roller

Claims (1)

[Scope of Claims] 1. After forming an electrostatic charge image on a photoreceptor, converting it into a latent image using a two-component developer, and transferring this toner image to transfer paper, toner remaining on the surface of the photoreceptor In an electrophotographic copying machine in which a magnetic brush cleaning unit removes
An electrophotographic copying apparatus characterized in that a carrier housed in the magnetic brush cleaning section is coated with a low surface energy material in which a conductive material is dispersed. 2. The copying apparatus according to claim 1, wherein the low surface energy material is a silicone resin. 3. The copying apparatus according to claim 1, wherein the low surface energy material is a fluororesin. 4. The copying apparatus according to claim 1, wherein a triboelectric charge imparting substance is dispersed and contained in the coating layer. 5. The conductive material is TiO_2, SnO_2, ZnO
2. The copying apparatus according to claim 1, wherein the material is at least one selected from the group consisting of conductive fibers, carbon black, and conductive fibers. 6. The copying apparatus according to claim 1, wherein the conductive substance is added in a proportion of 0.1 to 100 parts by weight per 100 parts by weight of the low surface energy substance. 7. The copy according to claim 4, wherein the triboelectric charging substance is at least one selected from nigrosine dyes, xanthene dyes, compounds having amino groups, metal complex dyes, salicylic acid metal salts, and salicylic acid derivative metal salts. Device. 8. The triboelectric charging material is a low surface energy material 10
8. The copying apparatus according to claim 4, wherein the amount is added in a ratio of 0.05 to 80 parts by weight relative to 0 parts by weight.