JPH11236210A - Preparation of polysilane compound, photoreceptor using the same and image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polysilane compd. excellent in mechanical strength, film characteristic, solubility to an org. solvent and durability to UV by allowing a silicon alkoxide to react with a polysilane to synthesize a silica gel and treating this silica gel with an alkali metallic compd. SOLUTION: A silicon alkoxide represented by formula I or II is allowed to react with a polysilane represented by formula III to synthesize a silica gel. This silica gel is treated with an alkali metallic compd. represented by formula IV, e.g. lithium methoxide or lithium ethoxide to obtain the objective polysilane compd. The compd. of the formula I increases the strength of the polysilane compd. and enhances the physical and mechanical durability. The compd. of the formula II lowers the m.p. of the polysilane compd. and enhances the chemical durability. An optical carrier excitation layer and a carrier transferring layer of the polysilane compd. are laminated on an electrically conductive substrate to form a photosensitive layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a novel polysilane compound having a high carrier transport property, and more particularly to a photoreceptor having a film made of the polysilane compound having enhanced mechanical strength and an image forming apparatus equipped with the photoreceptor. Things.

[0002]

2. Description of the Related Art A polymer material such as poly-N-vinylcarbazole (PVK) has been used as a carrier transporting material for an electrophotographic photoreceptor. To meet this requirement, a low molecular weight resin-dispersed composite material in which a low molecular weight compound such as an arylamine derivative or a hydrazone derivative is dispersed in an inert polymer binder such as a polycarbonate resin has been proposed.

[0003] However, the recent demand for high carrier mobility in carrier transporting materials is not yet satisfactory, and higher carrier mobility, particularly higher hole mobility, is required.

For example, it has been proposed to employ a polysilane compound as a carrier transporting material for a photoreceptor for an image forming apparatus requiring a high carrier mobility. However, when polysilane is used alone, the weight of the polysilane compound is reduced. The average molecular weight is 50,000 to 2,500,000, and the hole mobility which is 10 or less of the number average molecular weight is 10
It has been proposed that the polysilane compound must be at least ^-5 cm ² / V · sec.

[0005]

However, the wurtz coupling reaction, which is the most common and practical method for synthesizing polysilane, generally has difficulty in controlling the molecular weight, exhibits a polymodal molecular weight distribution, and has a low yield. Therefore, it is difficult to provide a large amount of polysilane having a high molecular weight and a narrow molecular weight distribution at a low price. Therefore, the following means have been reported.

[0006] Polysilane and a polymer resin are mixed (see JP-A-4-178652). Polysilane / organic low-molecular-weight carrier transporting agent / polymer resin (JP-A-3-170940, JP-A-4-151669, JP-A-7-175) -2952
No. 64) Copolymer of polysilane and other polymer (JP-A-2-334)
No. 16, JP-A-2-153359).

However, according to each of these techniques, there is a problem that compatibility is poor and a uniform film cannot be obtained because the mixing is simply performed. There is a problem that the characteristics (high hole mobility) as a polysilane photoreceptor are lost, and further, a copolymerization reaction between polysilane and another polymer is not established.

Accordingly, an object of the present invention is to provide a method for producing a polysilane compound which does not impair the properties of polysilane, is excellent in mechanical strength and film properties, and is excellent in solubility in organic solvents and durability against ultraviolet light. .

Another object of the present invention is to provide a photoreceptor in which the film made of the polysilane compound of the present invention has enhanced mechanical strength.

Still another object of the present invention is to provide an image forming apparatus equipped with the photoreceptor of the present invention.

[0011]

The polysilane compound of the present invention is produced by reacting a silicon alkoxide of the formula (1) or (2) with a polysilane of the formula (3) to synthesize silica gel. It is characterized by being treated with a metal compound.

[0012]

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[0013]

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[0014]

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[0015]

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Where n is the degree of polymerization and the substituent R ¹
Is a hydrogen atom, an alkyl group, a substituent R ² is an alkyl group, an alkenyl group, a phenyl group, and a substituent R ³ is a hydrogen atom or an alkyl group (n is 1 or 2). M is an alkali metal or an alkaline earth metal (where n is a metal M
Valence). The substituent R ⁴ is a hydrogen atom or an alkyl group.

The substituents R ⁵ , R ⁶ , R ⁷ , R ⁸ , R ⁹ , R
^{10, R '5, R'} 6, R '7, R' 8, R '9, R '10 represents hydrogen,
There are an alkyl group, a substituted alkyl group, an aryl group, a substituted aryl group, an alkoxy group, a substituted alkoxy group, an amino group, a substituted amino group, and a halogen.

The alkyl, aryl, alkoxy and amino groups include, for example, methyl, ethyl, propyl, butyl, amyl, hexyl, octyl, nonyl,
Decyl, pentadecyl, stearyl, cyclohexyl,
Examples include phenyl, tolyl, xylyl, naphthyl, methoxy, ethoxy, dimethylamino, diethylamino and the like. Further, as these substituents, alkyl, aryl,
There are halogen, nitro, amino, alkoxy, cyano and the like. R ¹¹ is an alkyl group.

The photoreceptor of the present invention is characterized in that a photosensitive layer of a laminate of a photocarrier excitation layer and a carrier transporting layer comprising the polysilane compound of the present invention is formed on a conductive substrate.

The image forming apparatus of the present invention comprises a photoreceptor of the present invention, a developing means disposed on the photosensitive layer side of the photoreceptor, and a means for irradiating image exposure light from a conductive substrate having translucency. And irradiating image exposure light from the exposure means while applying a voltage between the developing means and the conductive substrate so as to form a toner image on the surface of the photoreceptor.

Another image forming apparatus of the present invention comprises the photoreceptor of the present invention, a charging unit for applying a charge to the surface of the photoreceptor, and an exposing unit for irradiating the charged area of the photoreceptor with light, Developing means for forming an electrostatic latent image on the surface of the photoreceptor by means of the charging means and exposure means and forming a toner image corresponding to the electrostatic latent image on the photoreceptor; transfer means for transferring the toner image to a material to be transferred Cleaning means for removing residual toner on the surface of the photoreceptor after the transfer, and charge removing means for removing the residual electrostatic latent image after the transfer.

[0022]

BEST MODE FOR CARRYING OUT THE INVENTION (Structure of polysilane compound) The present inventor has studied a polysilane compound having excellent mechanical strength and film characteristics without impairing the characteristics of the polysilane compound. It has been proposed that polysilane compounds doped with polysilane have excellent mechanical strength and film properties.

That is, the polysilane compound having an alkoxy group is chemically immobilized in silica gel to prevent the polysilane compound from being eluted from the silica gel, thereby improving the physical durability. It has been found that a film can be produced.

However, the polysilane compound immobilized in the silica gel may have a reduced durability. This is because the polysilane compound contains an organic substance and cannot be heat-treated at a high temperature, so that many hydroxyl groups are present in the silica gel. Therefore, the acid sites in the silica gel are considerably large, and the
3 to 4. For this reason, the doped polysilane compound is liable to be deteriorated, and the deterioration reaction is particularly accelerated by light irradiation, and oxidative deterioration and low chemical durability are remarkable.

Therefore, when applied to an electrophotographic photoreceptor, doped silica gel, which is a conventional polysilane compound, is not practically sufficient in terms of durability, and a solution to these problems has been demanded.

The present invention has been completed in view of the above circumstances. As described above, the polysilane compound of the present invention is obtained by reacting the silicon alkoxide of formula 1 or 2 with the polysilane of formula 3 to synthesize silica gel. Then, the silica gel is treated with an alkali metal compound of the formula (4).

The polysilane compound thus obtained is a composite of an organic-inorganic hybrid structure doped (doped by a chemical bond) in silica gel and has a three-dimensional complex structure.

Chemical formula 1 is for increasing the strength of the polysilane compound and improving the physical and mechanical durability. Chemical formula 2 reduces the acid point of the polysilane compound,
This is for improving the chemical durability.

Next, the production method of the present invention will be described. Since the polysilane of Chemical Formula 2 has an alkenyl group, it is polycondensed with silicon alkoxide by hydrolysis.
A -0-Si bond can be generated and chemically bonded to silica gel. Then, in the coexistence of the alkyl metal compound represented by the chemical formula 4, the silicon alkoxide represented by the chemical formula 1 or 2 and the polysilane having an alkoxy group at the terminal are co-hydrolyzed and condensed. In such a method, a known sol-gel method may be adopted.

Formula 4 includes, for example, lithium methoxide, lithium ethoxide, sodium methoxide, sodium ethoxide, potassium methoxide, potassium ethoxide, calcium methoxide, calcium ethoxide and the like.

For example, first, a siline alkoxide represented by the formula (1) or (2) and a polysilane having an alkoxy group at its terminal are dissolved in an acidic alcohol aqueous solution (ph 2 to 3, 1).
(0 molar times dilution). In this reaction, the polysilane having an alkenyl group at the terminal is generally mixed with a silicon alkoxide to cause hydrolysis, and then the silicon alkoxide and the compound are partially condensed to form an oligomer. Next, this is mixed with an alcohol solution containing an alkali metal compound in an amount of 1 to 0.01 mol based on silicon alkoxide to form a thin film.

More specifically, the oligomer state of the polysilane compound is determined by a bar coating method, a dipping method, a melt extrusion method,
When applied by a spray method or the like and then dried to form a film, a film of a polysilane compound having high polysilane characteristics having high carrier transport characteristics and excellent mechanical strength is obtained.

(Structure of Photoconductor) FIGS. 1 and 2 show a basic layer structure of the photoconductor of the present invention. FIG. 1 shows an example in which a laminated photosensitive layer 2 is formed on a conductive substrate 1. The photosensitive layer comprises a photoexcitation layer 3 and a carrier transport layer made of a polysilane compound, and these layers 3, 4 may be arranged in a different order. FIG. 2 shows an example in which a photosensitive layer 7 containing a particulate photoexciter 6 in a carrier transporter 5 made of a polysilane compound is formed on a conductive substrate 1.

The conductive substrate 1 is made of copper, brass, SUS,
There is a metal conductor such as Al or Ni, or an insulating layer such as glass or ceramic coated with a conductive thin film. The substrate 1 may be a sheet-shaped, belt-shaped or web-shaped flexible conductive sheet. Such a sheet has a metal sheet such as SUS, Al, Ni, or a polymer resin film such as polyester or nylon polyimide, or a metal such as Al, Ni, tin oxide, indium tin oxide (ITO), or the like. A transparent conductive material or an organic conductive material coated by vapor deposition or the like and subjected to a conductive treatment is used.

As a constituent material of the photoexcitation layer 3 or the photoexcitation body 6, an organic or inorganic photoconductive material known per se is used. Organic semiconductor with high carrier generation efficiency using titanyl phthalocyanine, metal phthalocyanine pigment, metal-free phthalocyanine, perylene pigment, polycyclic quinoline pigment, squarylium dye, azulenium dye, thiapyrylium dye, trisazo pigment, etc. Is selected.

The inorganic semiconductor includes amorphous Se or Se.
As, SeTe or Si (a-Se, a-SeAs,
a-SeTe, a-Si), CdS, ZnO and the like. If the photoexcitation layer 3 is to be formed, a vacuum deposition method, an active reactive deposition method, an ion plating method,
The sputtering is performed by an F sputtering method, a DC sputtering method, an RF negtron sputtering method, a DC negtron sputtering method, a thermal CVD method, a plasma CVD method, or the like.

When the carrier excitation layer 3 is formed of a-Si, carbon, nitrogen, oxygen, and germanium are added thereto to form amorphous SiC, SiN,
It may be a layer of SiO or SiGe. If a layer containing an element such as B or P as an impurity element for controlling conductivity is formed in these layers, a function such as carrier injection prevention can be provided.

When an a-Si-based powder is used as the particulate photoexcitator 6 of the photosensitive layer 7, the powder is a-Si-based.
It can be produced in the same manner as the system photoexcitation layer 2, and such a powder forms a granular shape, a column shape, and a flake shape. Its diameter is 0.15-5μ
m, preferably 0.1 to 3 μm, and the powder may be contained in the layer in an amount of 1 to 80% by weight, preferably 5 to 60% by weight. , By an ultrasonic dispersion method or the like.

In addition, titanyl phthalocyanine (TiO)
The photosensitive layer may be prepared by dispersing Pc (abbreviated as Pc) in a polysilane compound, and the sensitivity can be increased particularly for image exposure on the long wavelength side. This TiOPc is the raw material TiOP
The pigment c is subjected to purification treatment such as sublimation purification or purification with an acid or alkali, and is kneaded with a grinding aid or a solvent using various dispersers, or is collected in fine particles by a vapor deposition method and collected. , And then dispersed in polysilane using various solvents. Ti
The OPc content is from 1 to 80% by weight, preferably from 10 to
It may be contained at 60% by weight.

The photoreceptor of the present invention may be further improved or changed in accordance with the required electrophotographic characteristics based on the above basic constitution. For example, by providing an intermediate layer between the substrate 1 and the photosensitive layers 2 and 7 thereon, the chargeability can be increased and the residual potential can be reduced. Alternatively, a surface layer can be provided on these photosensitive layers 2 and 7 to enhance the chargeability and the durability thereof.

(Method of Forming Polysilane Compound Layer) The carrier transporting layer 4 and the photosensitive layer 7, which are polysilane compound layers, can be formed by various methods which have been known in the art. It is formed by dissolving in a solvent, applying by a coating method such as a bar coating method, a dipping method, a melt extrusion method, a spray method, and the like, and then drying. Such organic solvents include aromatic hydrocarbons such as benzene and toluene; alcohols such as methyl alcohol, ethyl alcohol and IPA; ethers such as tetrahydrofuran and dimethyl ether; ketones such as acetone and methyl ethyl ketone; esters; , Halogenated hydrocarbons, etc. are used,
These may be used alone or in combination of two or more.

(Image Forming Apparatus) The image forming apparatus equipped with the photoreceptor of the present invention employs an electrophotographic process in which an electrostatic latent image is formed on the surface of the photoreceptor by charging or applying a voltage and exposing to light. There are various types of devices,
For example, there are a Carlson method and a capacitance image method (NP method, KIP method) which are an optical backside exposure method and an external charge latent image method. In these electrophotographic image forming apparatuses, a carrier transport layer having a high mobility can be formed on the photoreceptor of the present invention equipped with the electrophotographic process, whereby carriers generated inside the photosensitive layer have a high level inside the layer. Since it moves at a speed, the time until an electrostatic latent image is formed is shortened, and as a result, the rotation speed of the drum-shaped photoconductor can be increased,
High speed image formation. In addition, even in the charge removal by exposure after transfer, the carrier generated inside the photosensitive layer quickly contributes to charge removal, so the area of the photosensitive layer required for charge removal is narrowed, and the speed of the photosensitive drum is increased. The body diameter can be reduced, and the size of the image forming apparatus can be reduced.

Each of these various types of image forming apparatuses can be configured as a copier or a printer.
Here, the copier has a configuration in which the light reflected from the original is exposed on the surface of the photoreceptor using an optical system such as a lens or a mirror, and the other printer emits light controlled by an electric signal. It has a structure in which the surface of the photoconductor is exposed using a light source (laser, LED, liquid crystal shutter, EL, etc.).

Light Back Exposure Method Next, an image forming apparatus (printer) of the light back exposure method will be described in detail. FIG. 3 is a schematic diagram showing an image forming apparatus 8 of this type, which is an electrophotographic image forming apparatus in which corona charging is unnecessary and exposure and development can be performed almost simultaneously. In the figure, 9 is the permeable support 1
0, the light-transmitting conductive layer 11, the photoexcitation layer 12, and 10 ^-5 c
Carrier transport layer 13 having a mobility of at least m ² / V · sec
And 14 are LEDs as exposure means
The head, 15 is a developing machine as a developing means, and 16 is a transfer roller as a transferring means. The LED head 14 and the developing device 15 are arranged substantially symmetrically via a part of the photoconductor. As such an LED head 14, a small and low power consumption dynamic drive type LED head is preferably used. Reference numeral 17 denotes an LED array as an erase light source serving as a charge removing unit, and may be arranged outside the photoconductor 9. Also, 17 is not always required.

The developing device 15 comprises, for example, a columnar magnetic pole roller 18 having eight poles and a cylindrical sleeve arranged around the outer periphery thereof. The two-component developer composed of the conductive magnetic carrier and the insulating toner is delivered to the outer periphery of the sleeve 19 to form the magnetic brush 21.

A bias power source 22 is provided between the sleeve 19 and the light-transmitting conductive layer 11.
During the period 2, a voltage of + or-(500 V or less) is applied according to the potential characteristics of the photoconductor 9.

Reference numeral 23 denotes a toner image formed on the surface of the photoreceptor, reference numeral 24 denotes a recording sheet as a material to be transferred, and reference numeral 25 denotes residual toner after transfer. In addition, a rotation driving unit for the developing machine and a rotation unit for the photoconductor 9 are provided.

Although an LED head is used here as the exposure means 14, a laser, a liquid crystal shutter, an EL head, or the like may be used. As the erase power supply 17, a light source such as a halogen lamp, a fluorescent lamp, and an EL array can be used in addition to the LED array.

Thus, according to the image forming apparatus 8 having the above-described configuration, light for image exposure is emitted from the translucent support 10 of the rotating photoreceptor 9 from the LED head 14, so that holes and electrons are When a negative bias voltage is applied to the developing device side, the holes move to the surface side of the carrier transport layer 13 by the bias voltage and cancel out the negative charges at the end of the magnetic brush 21, The toner adheres to the surface of the photoconductor 9. Then, the toner is transferred onto the recording paper 24 by the transfer roller 16 and then fixed.

In the present invention, the photoexcitation layer 12 and the carrier transport layer 13 made of a polysilane compound are combined, and the mobility of the carrier transport layer 13 is set to 10 ⁻⁵ c.
m ² / V · sec or more to provide high carrier transport characteristics, whereby the carriers generated in the photoexcitation layer 12 are efficiently transported to the surface of the carrier transport layer 13, so that a high image forming apparatus Is obtained.

Next, the specific structure of the image forming apparatus will be described in more detail with reference to FIG. FIG. 4 is an explanatory view showing a part of the photoreceptor and a developing pool 26 formed by a developing machine. The developing device 15 for supporting the developer includes a conductive sleeve 19 and a magnetic roller 18 disposed therein, and the developer is conveyed by fixing the magnetic roller 18 and rotating the sleeve 19. Alternatively, the inner magnetic roller 18 may be rotated with the sleeve 19 fixed. Here, when the developer is conveyed in the direction opposite to the photosensitive member 9, a development pool 26 is formed downstream of the closest part between the developing device 15 and the photosensitive member 9 (the side where the photosensitive member is separated from the developer) due to friction between the two. . In other words, the portion of the developer protruding beyond the original height is the developer reservoir 26, and the transport speed of the developer, the height of the developer,
The gap between the sleeve 19 and the surface of the photoconductor 9 is appropriately set according to the rotation speed of the photoconductor 9 and the required size of the developer reservoir 26.

Reference numeral 27 denotes a control electrode.
Is provided on the sleeve 19 at a position closest to the photosensitive member 9, and is insulated from the sleeve 19 by the insulator 28. The control electrode 27 has a band shape along the length of the sleeve 19 so that a uniform electric field is applied to the photoconductor 9 and the developer. This control electrode 27
Is not indispensable and is adopted as appropriate.

As the developer, for example, a conductive magnetic toner is used. This forms the magnetic brush 21 and the developing reservoir 26, and may be a one-component developer as long as it has the necessary conductivity. It is also possible to use a two-component developer having a required conductivity by mixing a conductive carrier and an insulating toner at a predetermined mixing ratio.

The position where the image exposure is performed is not the closest position A between the surface of the photosensitive member 9 and the developing three portion 19, but the developer pool 26 formed on the downstream side of the photosensitive member 9 in the reverse rotation direction.
, And preferably the latter half of the developer reservoir 26 on the downstream side. By performing the exposure at the position of the developer reservoir 26, the photoconductor 9 is sufficiently charged before the exposure, and the influence of the history of the potential of the photoconductor 9 before charging is suppressed. The toner remaining on the surface and the toner in the image background are sufficiently collected. Further, since the photosensitive member 9 is sufficiently charged and exposed to light to eliminate the charge, the electric attraction between the developer and the photosensitive member 9 is strong, and a good toner image 23 is formed. After the formation of the toner image 23, the photoconductor 9 is quickly separated from the developer reservoir 26, so that the toner 23 on the surface of the photoconductor 9 is not disturbed by mechanical force such as collision or friction of the developer. Thus, the toner 23 having good resolution can be obtained.

At the position of the developer reservoir 26, the distance between the surface of the photosensitive member 9 and the magnetic roller 18 is larger than at the position A where the surface of the photosensitive member 9 and the developing sleeve 19 are closest.
For this reason, the magnetic force for attracting the developer toward the magnetic pole roller 18 is weak, and a part of the toner image formed on the surface of the photoreceptor 9 is collected by the magnetic force at the developing unit side to reduce the image density. It is possible to prevent the resolution from being lowered due to the magnetic force.

Further, the belt-like control electrode 27 is grounded to have a common potential with the light-transmitting conductive layer 11. Or sleeve 19
The potential is set lower or higher than the potential of.
When the control electrode 27 to which a potential can be applied independently of the sleeve 19 is provided, the surface potential of the photoconductor 9 is neutralized through the developer, or the potential of the surface of the photoconductor 9 is made uniform.
The influence of the history of the photoconductor 9 due to the presence or absence of charging or exposure in the previous process can be canceled. As a result, when repeatedly used, for example, when the photoconductor 9 is rotated several times to obtain one image, a stable developed state and a recorded image can be obtained. Here, by adjusting the potential of the control electrode 27, it is possible to adjust and obtain the optimum image forming conditions for the image density, the background fog, and the like. In addition, by raising the potential of the control electrode 27 and lowering the potential of the sleeve 19, the toner adheres to the non-exposed portion and the toner does not adhere to the exposed portion, so-called reversal development has become possible.

The toner image 23 formed on the surface of the photosensitive member 9
In response to the above, the residual toner 25 transferred to the recording paper 24 and fixed to form a recorded image, and remaining on the surface of the photoreceptor 9 without being transferred is transferred to the developing device 1 in the next image forming process.
5 and reused.

Further, by irradiating the photoreceptor 9 after the transfer with static elimination light by the erasing light source 17, the influence of the history of the photoreceptor 9 due to the charging in the previous process or the presence or absence of the exposure is more effectively canceled. This makes it possible to control image problems such as an afterimage phenomenon during repeated use. In addition, the charge trapped on the surface of the carrier transport layer 13 of the photoconductor 9 is erased to eliminate the electric attraction between the photoconductor 9 and the afterimage toner, thereby removing the afterimage toner from the developing device 1.
5, it is easy to be collected.

This carrier transport layer 13 is
Good surface characteristics can be provided even when the surface layer also serves as the surface layer.

External charge fusion method The external charge latent image method includes the Carlson method and the capacitance image method (
The NP method and the KIP method are typical examples. The Carlson method will be described with reference to FIG.

FIG. 3 shows an image forming apparatus 30 having a printer configuration.
And 31 is a drum-shaped photoconductor according to the present invention,
A corona charger 3 as charging means is provided on the peripheral surface of the photoreceptor 31.
2 and an exposure device 3 as an exposure means for irradiating light after the charging.
3, a developing unit 35 as a developing unit having a toner 34 for forming a toner image on the surface of the photoreceptor 31, a transfer unit 37 as a transferring unit for transferring the toner image to a transfer material 36, After the transfer, a static eliminator 39 for removing residual toner on the surface of the photoconductor is arranged. Reference numeral 40 denotes a fixing device for fixing the toner image transferred to the transfer material 36 by heat or pressure.

In the Carlson method, the following processes are repeated. The peripheral surface of the photoconductor 31 is charged by the corona charger 32. By exposing the image with the exposure device 33, an electrostatic latent image as a potential contrast is formed on the surface of the photoconductor 31. This electrostatic latent image is developed by the developing device 35. By this development, the black toner adheres to the surface of the photoreceptor by electrostatic attraction with the electrostatic latent image and is visualized. The toner image on the surface of the photoreceptor is electrostatically transferred from the back surface of the transfer material 36 such as paper by applying an electric field having a polarity opposite to that of the toner, thereby obtaining an image on the transfer material 36. The cleaning unit 38 mechanically removes residual toner on the surface of the photoconductor. The entire surface of the photoreceptor is exposed to intense light, and the remaining electrostatic latent image is removed by the charge removing means 39.

Thus, according to the image forming apparatus 30 having the above-described structure, the carriers generated inside the photosensitive layer by the irradiation of the light from the exposure unit 33 move inside the layer at a high speed.
The time for forming the electrostatic latent image is shortened, the rotation speed of the drum-shaped photoconductor 31 can be increased, and the image formation can be performed at a high speed. In addition, even in the charge removal by exposure after transfer, the carrier generated inside the photosensitive layer quickly contributes to charge removal, so the area of the photosensitive layer required for charge removal is narrowed, and the drum shape is increased in conjunction with the higher speed of the photosensitive drum. The diameter of the photoconductor can be reduced, and the size of the image forming apparatus can be reduced.

The image forming apparatus 30 has a printer configuration. However, if an optical system such as a lens or a mirror that transmits reflected light from a document is used instead of the exposure unit 33, the image forming apparatus 30 can be used as a copier. Become.

[0065]

EXAMPLES (Example 1) In this example, toluene, which is a solvent, was added to
At a reaction temperature of 110 ° C., a dechlorination-condensation reaction with sodium was carried out to synthesize polysilanes represented by Chemical formulas 6 to 9.

[0066]

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[0067]

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[0068]

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[0069]

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The weight average molecular weight Mw and the number average molecular weight Mn of these polysilanes were measured using gel permeation chromatography, and Mw and Mw / Mn were obtained. The results shown in Table 1 were obtained. Was. The table also shows the hole drift mobility of each polysilane obtained by the TOF method.

[0071]

[Table 1]

In Chemical Formula 6, X = 1, Y = Z = 0, and a polysilane compound (a) was synthesized in which R ⁵ is a methyl group and R ⁶ is a phenyl group. In the chemical formula 7, X = 1,
A polysilane compound (b) in which Y = Z = 0, R ⁵ is a methyl group, and R ⁶ is an isopropyl group was synthesized. In formula 8, X = Y = 1, Z = 0, and R ⁵ , R ⁶ , R
^A polysilane compound (c) in which ⁷ is a methyl group and R ⁸ is a phenyl group was synthesized. In the chemical formula 9, X = 1,
Y = Z = 0, X ′ = 1, Y ′ = Z ′ = 0, and R ⁵ ,
R ^6, R ^'5 is a methyl group, R' ⁶ were synthesized polysilane compound (d) is a phenyl group.

(Example 2) Four kinds of polysilanes (a) to (d) synthesized in (Example 1) were selectively alkoxylated in THF in THF to obtain a polysilane compound (a) having an alkoxy group. -1) to (d-1) were synthesized. Such alkoxylation can be easily performed by converting a terminal chloro group into an alkoxy group as shown in Chemical formula 5. In addition, terminal alkoxylation is ¹ H-N
It was identified using MR, ¹³ C-NMR, ²⁸ Si-NMR, ultraviolet-visible spectrophotometer, and infrared spectrophotometer.

[0074]

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Next, the solution obtained by dissolving the above polysilane (a-1) and tetramethoxysilane in ethanol was added with PH.
Hydrochloric acid-ethanol aqueous solution of No. 3 was added, and the mixture was stirred at a temperature of 25 ° C for 5 hours. This reaction solution was dip-coated on a clean glass substrate. After the solvent evaporates, 12
After heat treatment at 0 ° C. for 10 minutes, after cooling, dip coating was performed again, this operation was repeated 10 times, and finally heat treatment was performed at 120 ° C. for 4 hours to obtain a polysilane compound of the present invention in the form of a film.

The hole drift mobility of the film-form polysilane compound was measured by the TOF method.
It is 3 × 10 ⁻⁴ cm ² / V · sec, and the present inventor considers that there is no breakage of the molecular chain and that the silica gel is doped. Further, polysilanes (b-1), (c-1),
Also in (d-1), the hole mobility was hardly changed as compared with the polysilane before crosslinking. Thus, it can be seen that according to the polysilane compound of the present invention, the silica gel was doped into the silica gel without being decomposed and capable of moving holes.

However, it was found that the above four types of polysilane compounds exhibited sufficient characteristics at the initial stage, but as shown in Table 2, the characteristics decreased over time.

[0078]

[Table 2]

As is clear from this table, the hole drift mobility was lower by one digit or more than the initial value after 2,000 hours. The present inventor believes that the doped polysilane compound decomposes with the passage of time, and the degree of polymerization decreases, thereby decreasing the hole mobility.
(Example 3) Next, the same reaction as in (Example 2) was carried out in the presence of an alkali metal compound to prepare a polysilane compound.

That is, the solution obtained by dissolving polysilane (a-1) and tetramethoxysilane in ethanol was added with Ph
Hydrochloric acid-ethanol aqueous solution of No. 3 was added and stirred at 25 ° C. for 5 hours. Then, sodium methoxide was added to polysilane (a
-1) was added in an amount of 0.1 mol to prepare a silica gel containing a polysilane compound.

Thereafter, the reaction solution was dip-coated on a clean glass substrate. After the solvent evaporates, 1
Heat treatment was performed at 20 ° C. for 10 minutes, and after cooling, dip coating was performed again, and this process was repeated 10 times. Finally, heat treatment was performed at 120 ° C. for 4 hours to obtain a target polysilane compound film.

The film has a hole drift mobility of T
When measured by the OF method, 1.4 × 10 ⁻⁴ cm ² /
A value of V seconds was obtained. The hole drift mobility of the used polysilane compound film is 1.6 × 10 ⁻⁴ cm.
² / V · sec, it is considered that the polysilane compound of the present invention is doped into silica gel without breaking the molecular chain.

Further, (b-1), (c-1), (d-
Regarding 1), a value almost the same as the hole drift mobility of the polysilane compound used was obtained.

When the hole drift mobility of the polysilane compound film after 2000 hours was measured in the same manner as in (Example 2), the results shown in Table 3 were obtained.

[0085]

[Table 3]

As is clear from this table, no decrease in mobility was observed in any of the polysilane compound films, indicating that the films had high hole transport characteristics. The present inventor believes that by reducing the acid sites in the silica gel, the decomposition of the polysilane compound in the film could be suppressed.

(Example 4) On a peripheral surface of a transparent cylindrical glass substrate or a plastic substrate, an IT
O is formed to a thickness of 1000 ° by active reactive vapor deposition, and then immersed in a liquid obtained by dispersing and mixing titanyl phthalocyanine and a polyester resin in chloroform, and then dried to form a 1 μm thick layer of titanyl phthalocyanine.
A thick photoexcitation layer 12 was formed. Next, the four types of polysilane compounds (a) to (Example 1)
Using (d), 20 μm of the polysilane compound
An m-thick carrier transporting layer 13 was formed to prepare a photoreceptor. As a result, with respect to the polysilane compounds (a) and (b), film peeling occurred after drying, and it was not possible to evaluate the photoconductor characteristics. With respect to other photoconductors containing polysilane compounds (c) and (d), the photoconductor characteristics could be evaluated.

The above evaluation was performed using the photoreceptor of the present invention using an image forming apparatus as shown in FIG. That is,
A photoreceptor is mounted on the image forming apparatus, and a two-component developer including a conductive magnetic carrier and an insulating toner is used as a developer.
A LED head of dpi is arranged, a voltage of Vs = −400 V is applied between the sleeve 19 and the transparent conductive layer 11, image exposure is performed at a wavelength of 660 nm, a toner image is formed on a photoconductor, and the toner image is formed. Was transferred onto plain paper by a transfer roller to which a transfer bias voltage of 400 V was applied, and was thermally fixed to obtain an image. The developer was rotated in a direction opposite to that of the photosensitive member 9 to form a developing pool 26, and the portion was exposed.

Thus, when the image of each photosensitive member was evaluated, all of the photosensitive members had an image density of 1.4 or more, no fogging of the background, and a good image having a resolution of 300 dpi. However, when the durability test of the photoreceptor was carried out, an image was obtained which was not different from the initial image up to about 2,000 continuous sheets, but the image density became 1.0 or less when the number exceeded 5,000 sheets. It was also found that these polysilanes had low durability.

(Example 5) Next, a photoreceptor was prepared using the polysilane compounds (a-1) to (d-1) obtained in (Example 3).

That is, a transparent conductive layer 11 is formed on the peripheral surface of a transparent cylindrical glass substrate or plastic substrate.
TO is formed to a thickness of 1000 ° by active reactive evaporation,
Then, it was immersed in a liquid obtained by dispersing and mixing titanyl phthalocyanine and a polyester resin in chloroform, and then dried to obtain a 1 μm-thick titanyl phthalocyanine.
A thick photoexcitation layer 12 was formed. Next, the polysilane compounds (a-1) to (d) of (Example 3) were
1) A polysilane-containing carrier transporting layer 13 having a thickness of 20 μm was formed to prepare a photoreceptor.

The photosensitive member was mounted on an image forming apparatus as shown in FIG. 3, and a two-component developer composed of a conductive magnetic carrier and an insulating toner was used as a developer. The LED head of dpi is disposed, and Vs = − between the sleeve 19 and the transparent conductive layer 11.
A voltage of 400 V was applied, image exposure was performed at a wavelength of 660 nm, a toner image was formed on the photoreceptor, and the toner image was transferred to plain paper by a transfer roller to which a transfer bias voltage of 400 V was applied, and heat-fixed. Image obtained. In addition,
The developer was rotated in the opposite direction to the photoreceptor 9 to form a developing pool 26, and the portion was exposed.

When the images obtained by the two photosensitive members were evaluated, all of them had an image density of 1.4 or more, no fogging of the background, and a resolution of 300.
An image having a good dpi was obtained. Regarding the durability test as a photoreceptor, even when 100,000 or more images were continuously formed, no change in image quality such as a decrease in image density and an increase in back fog was observed. Had the nature.

[0094]

As described above, according to the polysilane compound of the present invention prepared by reducing the acid point in silica gel, the hole transporting property is excellent, and the solubility in an organic solvent and the mechanical strength are excellent. The photoreceptor using the photoreceptor has excellent photoreceptor characteristics and durability, and is about 10 times more durable than a conventional polysilane-containing photoreceptor. As a result, the photoreceptor of the present invention has a high carrier. It could be suitably mounted on an image forming apparatus requiring mobility, for example, an image forming apparatus of a light back exposure type.

According to the image forming apparatus of the present invention, the carrier generated inside the photosensitive layer by the light irradiation of the exposure means moves at a high speed inside the layer, so that the time required for forming the electrostatic latent image is reduced. As a result, the rotation speed of the drum can be increased with a drum-shaped photosensitive member, and the image formation can be performed at a high speed. In addition, even in the charge removal by exposure after transfer, the carrier generated inside the photosensitive layer quickly contributes to charge removal, so the area of the photosensitive layer required for charge removal is narrowed, and the speed of the photosensitive drum is increased. The diameter of the photoconductor can be reduced, and the size of the image forming apparatus can be reduced.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of a photoconductor of the present invention.

FIG. 2 is a cross-sectional view of the photoconductor of the present invention.

FIG. 3 is a schematic diagram illustrating an electrophotographic method used in the image forming apparatus of the present invention.

FIG. 4 is a main part configuration diagram of the image forming apparatus of the present invention.

FIG. 5 is a schematic configuration diagram of an image forming apparatus of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductive substrate 2 Laminated photosensitive layer 3 Photoexcitation layer 4 Carrier transport layer 5 Carrier transporter 6 Photoexciter 7 Photosensitive layer

Claims (4)

[Claims] 1. A polysilane comprising reacting a silicon alkoxide of the following chemical formula (1) or (2) with a polysilane of the chemical formula (3) to synthesize silica gel, and then treating the silica gel with an alkali metal compound of the chemical formula (4). Preparation of the compound. Embedded image Embedded image Embedded image Embedded image 2. A photoreceptor comprising a conductive substrate and a photosensitive layer formed by laminating a photocarrier excitation layer and a carrier transporting layer comprising the polysilane compound according to claim 1. 3. The photoreceptor of claim 2, a developing means disposed on the photosensitive layer side of the photoreceptor, and a means for irradiating image exposure light from a light-transmitting conductive substrate side. An image forming apparatus, wherein an image exposure light is irradiated from an exposure unit while applying a voltage between the developing unit and a conductive substrate so as to form a toner image on a surface of the photoreceptor. 4. The photoreceptor of claim 2, a charging means for applying a charge to the surface of the photoreceptor, and an exposure means for irradiating the charged area of the photoreceptor with light. Developing means for forming an electrostatic latent image on the surface of the photoreceptor and forming a toner image corresponding to the electrostatic latent image on the photoreceptor; transfer means for transferring the toner image to a material to be transferred; A formed image forming apparatus, comprising: a cleaning unit for removing residual toner on a body surface; and a charge removing unit for removing a residual electrostatic latent image after the transfer.