JPH07219398A - Image forming device - Google Patents

Abstract

PURPOSE:To prevent irregular shaving of an image carrier body and to prolong its life by forming a specified surface protective layer on an image carrier photosensitive layer and rotating a cleaning blade having a nylon layer on the surface around a specified axial li ne. CONSTITUTION:A surface protective layer containing conductive particles and fluorine atom-contg. resin fine particles is formed on the photosensitive layer of an image carrier body 10. The protective layer consists of polyester or the like having 0.05-15mum thickness, preferably 1-10mum thickness. The fluorine atom- contg. resin fine particles consist of polytetrafluoroethylene or the like. The surface of the cleaning blade 26 is coated with nylon containing dispersion of fluorocarbon. The blade is made to rotate around the axial line perpendicular to the axial line of the image carrier body 10 rotating. Namely, the cleaning blade 26 is held by an axis 29 and brought into contact with the image carrier body 10 by a spring 28. Thereby, even when strength of the surface protective layer is decreased, the carrier body is hardly damaged and its life can be prolonged.

Description

Detailed Description of the Invention

[0001]

[Object of the Invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus using an electrostatic transfer process, such as an electrostatic copying machine and a printer.

In the well-known image forming apparatus as described above, a laser beam printer or the like which forms an image by a digital signal in recent years can convert the image signal into an electric signal and process it. Since it becomes easier, etc., it is being used more and more.

In an image forming apparatus using a digital signal, if the particle size of the toner that visualizes the electrostatic latent image is large, the image becomes thick and the aging deteriorates. From this point, the smaller the particle size of the toner is. It is advantageous.

At the same time, when the toner particle size becomes smaller,
In order to obtain the same image density, it is necessary to increase the amount of toner attached, which results in the necessity of improving the transfer efficiency.

In order to solve this point, it is possible to reduce the charge amount of the toner, increase the transfer current, increase the amount of the colorant in the toner, and the like, but increase the scattering amount of the toner and the transfer material. This is not preferable because problems such as toner scattering to the top and generation of charging memory occur.

Further, when the particle size of the toner becomes small, the amount of toner that slips through the cleaning blade at the cleaning portion increases. Therefore, in order to prevent this, it is necessary to increase the pressing force of the blade to the image bearing member. The amount of abrasion of the photosensitive layer of the body is increased, and the blade is easily turned up.

In order to avoid such a problem, it has been proposed to coat the blade with a fluororesin in a proper place or to coat the surface of the blade so that it smoothly slides on the surface of the image carrier, but the former is used. The resin peels off due to long-term use, and in the latter case the coating layer does not easily follow the urethane rubber that is the blade material, so it is necessary to press the blade more strongly to prevent the toner from passing through. The amount of scraping is unavoidable.

In order to solve these problems at the same time, it has been proposed to disperse the surface of the image bearing member by using a material having a high releasability or a substance having a high releasability. When the releasability of the surface becomes high, the amount of scraping becomes small, and the ozone adhered to the image carrier, which was removed along with the deviation,
Removal of nitrogen oxides, the filler added to the developer, etc. becomes insufficient, and a state with apparently low releasability is formed, and blade curling is likely to occur.

However, with such means, there remains a problem that the cleaning blade is unevenly scraped due to a delicate pressure difference in a portion in contact with the image bearing member. In order to deal with such a problem, a cleaning blade that abuts like an image carrier, a holder that supports the cleaning blade, is a fulcrum that holds the holder swingably, and a pressing mechanism that presses the blade edge against the image carrier. In the cleaning device, the contact with the image carrier at the position where the blade contacts the image carrier at the blade edge portion, and the angle α between the contact direction of the blade, and the line connecting the blade edge and the fulcrum The angle β formed is made larger and the blade edge recedes toward the delivery side and the bending of the blade becomes larger as the applied stress becomes larger. However, there is a problem that the toner slips through when the image is turned over.

The present invention has been made in view of the above circumstances, in which a protective layer is formed on the surface of an image bearing member, a cleaning blade is provided with a coating, and the cleaning blade is made into small particles by using the equalizing mechanism. It is an object of the present invention to reduce the use of an image forming apparatus that enables the use of toner having a diameter, prevents the occurrence of abrasion unevenness of the image carrier and achieves a long life.

[0010]

[Constitution of the invention]

In order to achieve the above object, the present invention provides an image forming apparatus comprising a surface protective layer containing conductive particles and fluororesin particles on a photosensitive layer of an image carrier. A cleaning device is provided, which has a nylon layer on the surface thereof and has a cleaning blade which rotates about an axis perpendicular to the axis of the image carrier.

With this structure, the image carrier is less likely to be damaged and the life can be extended.

[0012]

Description of Embodiments An image carrier used in the present invention will be described. As the conductive substrate of the image carrier, iron, copper, gold,
Metals and alloys such as silver, aluminum, titanium, lead, nickel, tin, antimony, and indium, oxides of these, carbon, and conductive polymer may be used.

The above-mentioned conductive material is molded as it is, and a layer is formed by a suitable method such as coating, vapor deposition, etching and plasma treatment.

The photosensitive layer may be a single layer or multiple layers, and the layer thickness is 10 to 35 μm, preferably about 15 to 30 μm.
In the case of a laminated structure, it is composed of at least a charge generation layer and a charge transport layer, but there are cases where a charge generation layer is provided on the side of the conductive substrate and where a sleep charge transport layer is provided. Is different.

As the charge generating material, phthalocyanine pigment, polycyclic quinone pigment, trisazo pigment, disazo pigment,
Examples thereof include azo pigments, perylene pigments, indigo pigments, quinacridone pigments, azurenium salt dyes, squalium dyes, siayun dyes, pyrylium dyes, thiopyrylium dyes, xanthene dyes, quinoimine dyes, triphenylmethane dyes and styryl dyes.

The thickness of the charge generation layer is 0.001 to 6 μ, preferably 0.01 to 2 μ. The content of the charge generating material contained in the charge generating layer is 10 to 100% by weight, preferably 50 to 100% by weight.

As the charge transport material, a bilene compound, an N-alkylcarbazole compound, a hydrazone compound, N,
Examples thereof include N-dialkylaniline compounds, diphenylamine compounds, triphenylamine compounds, triphenylmethane compounds, polycyano compounds, mixtures of these compounds, and pendant polymers having these compounds fixed on a polymer.

The thickness of the charge transport layer is the thickness of the photosensitive layer minus the thickness of the charge generation layer. The content of the charge transport material contained in the charge transport layer is 20-80% by weight, preferably 30-70% by weight.

The charge transport material is often dispersed in a binder resin binder having film forming properties to form a photosensitive layer.
As the binder resin binder, polyester, polyurethane, polyarylate, polyethylene, polybutadiene,
Polycarbonate, polyamide, polypropylene, polyimide, phenol resin, silicon resin, epoxy resin, urea resin, allyl resin, alkyd resin, polyamide-imide, nylon, polysulfone, polyallyl ether, polyallyl acetal, butyral oil and the like can be mentioned.

An undercoat layer may be provided between the sleeping conductive gas and the photosensitive layer. The undercoat layer is mainly composed of a binder resin, and functions as a charge injection control at the interface and as an adhesive layer. As the binder resin, polyester, polyurethane,
Polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, phenol resin, acrylic resin, silicone resin, epoxy resin, area resin, allyl resin,
Examples include alkyd resin, polyamide-imide, nylon-based polysulfone, polyallyl ether, butyral resin and the like. The thickness of the undercoat layer is 0.05 to 7 µ, preferably 0.1 to 2 µ.

A protective layer is formed on the photosensitive layer. As the protective layer, polyester, polyurethane, polyarylate, polyethylene, polystyrene, polybutadiene, polycarbonate, polyamide, polypropylene, polyimide, phenol resin, acrylic resin, silicone resin,
Epoxy resin, area resin, allyl resin, alkyd resin, polyamide-imide, nylon, polysalphone,
Examples include polyallyl ether and butyral resin. The thickness of the protective layer is 0.05 to 15 μ, preferably 1 to 10 μ.

Further, in order to maintain the charge transport property in the protective layer and to make the frictional resistance of the surface of the charge transport layer constant,
Fluorine atom-containing resin fine particles are added. Further, in order to control the resistance value of the layer, it is preferable to add inorganic conductive particles.

The fluorine atom-containing resin fine particles include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polydichlorodifluoroethylene, tetilafluoroethylene-perfluoroalkylvinylether copolymer, tetrafluoroethylene-hexafluoropropylene. One or more selected from copolymers, tetrafluoroethylene-hexafluoropropylene copolymers, tetrafluoroethylene-ethylene copolymers, tetrafluoroethylene-hexafluoropropylene-perfluoroalkyl vinyl ether copolymers, etc. It consists of.

[Example 1] 50 parts by weight of conductive titanium oxide powder coated with tin oxide containing 10% antimony oxide, 25 parts by weight of fat and oil in phenol, 20 parts by weight of methyl cellosolve, 5 parts by weight of methanol and silicon Oily polydimethylshaxane polyoxyalkylene copolymer (number average molecular weight of 30,000) 0.002 parts by weight of φ1
The conductive paint was prepared by dispersing for 2 hours in a sand mill using glass beads of mm. Aluminum cylinder (φ80
X 360) and apply this paint by dipping onto 140. It was dried at C for 30 minutes to form a conductive layer having a film thickness of 20 μm.

Next, 30 parts by weight of methoxymethylated nylon resin (number average molecular weight 32000) and 10 parts of alcohol-soluble copolymerized nylon resin (number average molecular weight 29000) 10
By weight, a liquid dissolved in a mixed solvent of 260 parts by weight of methanol and butanol 40 was applied on the conductive layer by dipping coating to form an undercoat layer having a film thickness after drying of 1 μm.

The following disazo pigment of the following structural formula [1] 4 parts by weight, 2 parts by weight of benzal resin, and 40 parts by weight of tetrahydrofuran were dispersed for 60 hours in a sand mill using glass beads having a diameter of 1 mm, and then diluted with a mixed solvent of cyclohexanone and tetrahydrofuran to obtain a charge generation layer coating material. This solution was applied onto the undercoat layer by dipping coating to obtain a charge generation layer having a thickness of 0.1 μm after drying.

Next, the following structural formula [2] 10 parts by weight of the charge transport material and 10 parts by weight of a polycarbonate resin (number average molecular weight 25,000) are added to dichloromethane.
It is dissolved in a mixed solvent of 0 parts by weight and 40 parts by weight of monochlorobenzene, and this solution is dip-coated on the charge generation layer, 120. It was dried at C for 60 minutes to form a charge transport layer having a film thickness of 20 μm.

Next, 2 parts by weight of polytetrafluoroethylene fine particles (Lubrone-5: manufactured by Daikin Industries, Ltd.) and a polycarbonate resin (bispheno type; number average molecular weight 4)
0000) 4 parts by weight, the charge transport material of the structural formula [2],
250 parts by weight of monochlorobenzene, 250 of dichloromethane
Parts by weight were dispersed by a sand mill to obtain a protective layer coating material. Apply this paint by spraying 120. It was dried at C for 60 minutes to form a protective layer having a film thickness of 3.0 μm.

The present invention was applied to an image forming apparatus having a well-known structure using the image carrier thus constructed, and a paper passing test was conducted using a cleaning device having a structure as shown in the accompanying drawings.

The cleaning device at this time is shown in the accompanying drawings. The blade edge of the cleaning blade 26 is in contact with the image carrier 10 which is formed in the shape of a rotating cylinder and rotates in the direction of the arrow in the figure. The image carrier 10 is axially supported by a shaft 29, and is given a turning tendency in the clockwise direction in the drawing by a spring 28 so that the blade edge comes into contact with the image carrier at a total pressure of 1000 gf. The contact angle α of the cleaning blade 26 with respect to the image carrier 10 is 24.
The blade tip and β of the shaft 29 are set to 32 degrees.

The above-mentioned portion is swingable about the axis of the holder 30 which is parallel to the sleeping sheet as a whole, and has an equalizing mechanism in which the blade edge uniformly abuts the image carrier over the entire length.

The cleaning blade was coated with nylon in which 20% by weight of carbon fluoride was dispersed. The toner used had a particle size of 8 μm and had ClO ₂ added thereto.

The results of paper passing with the above are shown below. As the transfer material, A4 size, 80 gr paper is used, the durable number is 20,000, the rubber thickness of the cleaning blade is 2 mm,
Free length l = 7 mm (see the drawing), blade edge penetration into the image carrier surface 1.0 mm, linear pressure 33 gr / cm
The toner density was set to 5.0%. Addition amount Scraped amount image (Wt%) (mm) 0 0.8 × 0.1 1.0 〇 0.3 1.1 1.1 〇 0.7 1.6 〇 1.0 2.0 〇 〇 1.5 2. 7 〇 2.0 3.0 〇 2.5 3.5 × 〇 Good, △ No practical problems, × Image defects,

Example 2 A cleaning blade was coated under the same conditions as in Example 1 except that 30% by weight of polydichlorofluoroethylene was dispersed as a lubricating component and applied. Similar results were obtained.

Example 3 An experiment was conducted under the same conditions as in Example 1 except that zirconium-alumina was externally added to the toner. The results are shown below. Addition amount Shaving amount Image Remark (Wt%) (mm) 0.1 1.1 〇 0.2 1.2 〇 0.5 1.4 1.4 〇 0.8 1.8 〇 1.2 2.2 〇 1. 5 2.8 △ Toner slip-through scattered 2.0 × Overall toner slip-through

Example 4 An experiment was conducted under the same conditions as in Example 1 except that the toner particle size was 7 μm and the cleaning blade was initially coated with 2 μ of fluorocarbon. The results are shown below. Addition amount Scraped amount image (Wt%) (mm) 0 1.0 × 0.1 1.1 〇 0.2 1.3 1.3 〇 0.5 1.6 1.6 〇 0.7 2.0 〇 1.0 2. 3 ○ 1.2 2.5 ○ 1.5 3.2 3.2 △

In all of the above cases, the cleaning blade is made of urethane rubber, silicon rubber, fluororubber, N
BR, SBR, etc. can be used.

[0038]

As described above, the upper layer of the image carrier of the image forming apparatus is provided with the surface protective layer containing the conductive particles and the fluororesin particles, the cost is provided with the nylon layer, and the axis line of the image carrier is similar to that of the image carrier. By having the cleaning blade that rotates around the vertical axis, even if the strength of the cost protection layer is reduced, it is less likely to be damaged, and the characteristics of the image bearing member are effectively utilized to contribute to the extension of the durable life.

[Brief description of drawings]

FIG. 1 is a side view of a main part of a cleaning device suitable for being applied to the present invention.

[Explanation of symbols]

 10 image carrier 26 cleaning blade 28 spring 29 shaft 30 holder

Claims (1)

[Claims] 1. A surface protective layer containing conductive particles and fluororesin particles is provided on a photosensitive layer of an image carrier, a nylon layer is provided on the surface, and the surface is rotated about an axis perpendicular to the axis of the image carrier. An image forming apparatus having a cleaning device having a cleaning blade.