JP2001324903A - Image forming device and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device and an image forming method by which image flowing is prevented and the life of a drum is sufficiently prolonged in accordance with the service history (operating time and the number of image formed sheets or the like) of a photoreceptor having a hard coat layer. SOLUTION: In the electrophotographic image forming device, the photoreceptor is an organic photoreceptor provided with a resin layer incorporating siloxane resin having crosslinking structure, and the device is provided with a load adjusting means for adjusting the load of a blade abutting on the photoreceptor, and a control means for controlling the operation of the load adjusting means. The control means controls the load adjusting means so that the abutting load may be changed in accordance with the operating time of the photoreceptor. Thus, the image forming device having such characteristic and the image forming method using the image forming device are provided.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming apparatus and an image forming method using an electrophotographic method, such as a copying machine, a printer, and a facsimile, and more particularly, to adjusting a contact load of a cleaning member to a photosensitive member. And an image forming method.

[0002]

2. Description of the Related Art In an electrophotographic image forming apparatus, an electrostatic latent image formed on a photoreceptor is developed with toner to form a toner image, and the toner image is transferred to transfer paper to form an image. I do. The untransferred toner remains on the photoreceptor after the toner image has been transferred onto the transfer paper (residual toner). If the process for forming the next image is performed as it is, the residual toner will stain the next image. Therefore, it is necessary to clean and remove the residual toner.

Usually, as a method for cleaning the residual toner, a cleaning member called a blade is brought into contact with the surface of the photoconductor, and the cleaning is performed by scraping off the residual toner on the photoconductor. If the contact load of the blade on the photoconductor at this time is too low, the cleaning of the photoconductor surface becomes insufficient, and the edge of the image is blurred due to insufficient charge on the insufficiently cleaned portion. Flow "occurs. Conversely, if the contact load is too high, the speed of depletion of the photoreceptor surface will be increased, shortening the life of the photoreceptor (drum life), and causing the blade to be damaged.

[0004]

On the other hand, there has been proposed an organic photoreceptor provided with a resin layer containing a siloxane-based resin having a cross-linked structure in order to extend the drum life (hereinafter referred to as a hard coat photoreceptor). . This is obtained by applying a resin layer containing a siloxane-based resin (hereinafter, referred to as a hard coat layer) on the surface of the photoconductor, and the durability of the photoconductor is extremely excellent. This hard coat layer is likely to cause the above-described image deletion unless the contact load of the blade is increased. The surface of the photoreceptor wears out with time, but after the hard coat layer on the outermost surface has completely disappeared, a photosensitive layer having physical properties different from those of the hard coat layer is exposed. The rigidity of the photosensitive layer is, of course, lower than that of the hard coat layer.

Therefore, when the contact load of the blade is adjusted so that image flow does not occur in the hard coat layer, the depletion speed is accelerated in the photoreceptor layer, and the drum life cannot be sufficiently extended. found.

Accordingly, it is an object of the present invention to provide a photoreceptor having a hard coat layer which has a use history (use time, number of image formation, etc.).
The present invention relates to an image forming apparatus and an image forming method capable of preventing image deletion and sufficiently extending a drum life according to the image forming method.

[0007]

The object of the present invention has been attained by the following constitutions.

[0008] 1. A photoreceptor for forming an electrostatic latent image, developing means for developing the formed electrostatic latent image with toner in a developer, transfer means for transferring the developed toner image to transfer paper, and transfer In an image forming apparatus having a cleaning member for scraping and removing residual toner remaining on the photoreceptor later, the photoreceptor is an organic photoreceptor provided with a resin layer containing a siloxane-based resin having a crosslinked structure. A load adjusting unit that adjusts a contact load of the cleaning member to the photoconductor; and a control unit that controls an operation of the load adjusting unit.
An image forming apparatus, wherein the load adjusting unit is controlled to change the contact load according to a usage history of the photoconductor.

[0009] 2. The control means controls the load adjusting means so as to change the contact load when all of the resin layer of the photoconductor has disappeared.
An image forming apparatus according to claim 1.

[0010] 3. 2. The image forming apparatus according to claim 1, wherein the control unit controls the load adjusting unit to change the contact load when a predetermined number of images is formed.

4. 2. The image forming apparatus according to claim 1, wherein the control unit controls the load adjusting unit to change the contact load when a predetermined photoconductor usage time has been reached.

5. The image forming apparatus according to any one of claims 1 to 4, wherein the change of the contact load by the control unit controls the load adjustment unit so as to reduce the contact load.

6. Forming an electrostatic latent image on the photoreceptor, developing the electrostatic latent image to form a toner image, transferring the toner image to a transfer paper, and contacting a cleaning member with the photoreceptor to perform the transfer after the transfer In the image forming method for removing the residual toner remaining on the photoconductor, the photoconductor is an organic photoconductor provided with a resin layer containing a siloxane-based resin having a cross-linked structure, and the photoconductor of the cleaning member is provided. An image forming method comprising: a load adjusting step of adjusting a contact load on a body, wherein the load adjusting step changes the contact load according to a use history of the photoconductor.

7. The image forming method according to claim 6, wherein in the load adjusting step, the contact load is changed when all of the resin layer of the photoconductor has disappeared.

[8] 7. The image forming method according to claim 6, wherein the load adjusting step changes the contact load when a predetermined number of images is formed.

9. 7. The image forming method according to claim 6, wherein in the load adjusting step, the contact load is changed when a predetermined photoconductor usage time has been reached.

10. The image forming method according to any one of the above items 6 to 9, wherein the load adjustment step reduces the contact load.

[0018]

Embodiments of the present invention will be described below with reference to the drawings, but the present invention is not limited thereto.

FIG. 1 is a schematic configuration diagram of a copying machine as an image forming apparatus, FIG. 2 is a schematic configuration diagram of an image forming section of the copying machine, FIG. 3 is a front sectional view of a cleaning unit having a cleaning member, and FIG. 3 is a sectional view showing an IV-IV section, and FIG. 5 is a schematic view showing a part of the cleaning unit.

In FIG. 1, a copying machine 101 stores transfer papers 105 inside a main body, and feeds the transfer papers 105 to be used for an image forming operation one by one by a paper feed roller 106 having a double feed prevention mechanism. Carry in. The paper feed unit 109 is disposed immediately before the image forming unit 1 and includes a loop roller 110.
And a registration roller 111.

On the other hand, in the image forming section 1, the photosensitive drum 2
The (photoconductor) is rotated in the direction of arrow A by a driving unit described later, and a uniform potential is applied by the charging electrode 3, and the scanner unit 112 attaches a document (not shown) on the document mounting glass 113. The corresponding digital data is obtained and subjected to image processing. Based on the digital data subjected to the image processing, the scanning exposure unit 114 irradiates the surface of the rotating photosensitive drum 2 to form an electrostatic latent image corresponding to the document. Form. Next, the electrostatic latent image is visualized by a developing unit 5 (developing means), and a toner image is developed on the surface of the photosensitive drum 2.

The registration roller 111 is driven in synchronization with the rotation of the photosensitive drum 2, and the transfer paper 105 is sent to the transfer electrode 7 (transfer means). The toner image formed on the photosensitive drum 2 is transferred to the transfer paper 105 sent to the transfer electrode 7, and then the transfer paper 105 is separated from the photosensitive drum 2 by the separation electrode 8 and the separation claw 9. Then, the transport unit 117 transports to the fixing unit 118. A cleaning unit 11 disposed on the downstream side in the rotation direction of the photosensitive drum 2 with respect to the separation claw 9 cleans the surface of the photosensitive drum 2 after the transfer to remove foreign matters, residual toner, and the like. When the residual toner is removed, the charging electrode 3 charges the surface of the photosensitive drum 2 again in preparation for the next image forming operation.

The recycle pipe 6 conveys the residual toner collected by the cleaning unit 11 to the developing unit 5. The transported toner is used again for development.
The developing unit 5 incorporates new toner supplied from a toner cartridge (not shown), and consumes the new toner by executing an image forming operation. The collected toner is mixed with the new toner. In the present invention, the toner in which the collected toner is mixed with the new toner is also regarded as the new toner.

In the fixing unit 118, the transfer paper 105
Is heated and pressurized to fix the toner image. In the case of one-sided copy, the sheet is nipped by the conveyance roller 119 and sent to the sheet discharge tray 123. In the case of double-sided copying, the transfer paper 105 on which the toner image has been fixed is sent to the stacker 120 via the escaping conveyance path 121 by the conveyance roller 119 and temporarily evacuated. The transfer paper 105 temporarily evacuated into the stacker 120 is sent out again, and
The toner image is transferred and fixed again into the paper feeding unit 109 via the.

Next, details of the image forming section 1 will be described with reference to FIG. In the image forming section 1 of the copying machine 101, a charging electrode 3 (charging means), a scanning exposure section 114 (exposure means), and a developing unit 5 are provided around a photoconductor drum 2 (photoconductor).
(Developing means), a transfer electrode 7 (transfer means), a separating electrode 8, a separating claw 9, a cleaning unit 11, and a pre-charge exposure section (PCL) 12 (pre-charge exposure means) are arranged in this order. . These are connected to a control means 13 built in the copying machine 101. The control unit 13 operates a photoconductor drive unit (described later), a development unit, a transfer unit, a load adjustment unit, and the like based on information input by a user from an instruction input unit (not shown), and controls the entire copying machine 101. Performs a simple sequence control.

In the image forming section 1, a uniform negative charge is applied to the surface of the photosensitive drum 2 by the action of the charging electrode 3, and then the scanning exposure section 114 is rotated based on digital data subjected to image processing. The surface of the photoreceptor drum 2 is irradiated, and the charge of the irradiated portion is attenuated to form an electrostatic latent image. The toner is agitated inside the developing unit 5, and the toner takes a negative charge due to mutual friction. The developing unit 5 includes a sleeve 5 a having a rotation axis parallel to the rotation axis of the photosensitive drum 2. When a developing bias is applied to the sleeve 5 a, the electrostatic latent image becomes a negatively charged toner in the development unit 5. (Reverse development) to form a toner image on the surface of the photosensitive drum 2.

The transfer paper 1 is synchronized with the rotation of the photosensitive drum 2.
When the transfer electrode 05 is fed, the transfer electrode 7 applies a negative charge to the back surface of the transfer paper 105, and the toner image on the surface of the photosensitive drum 2 is transferred to the transfer paper 105. The transfer paper 105 on which the toner image has been transferred is neutralized by the discharge of the separation electrode 8 and the adsorption force to the photosensitive drum 2 is reduced. Then, the transfer paper 105 is guided to the separation claw 9 while being naturally separated by its own weight, and the separation is completed. Is sent to the fixing unit 118.

On the other hand, although the toner which is not transferred remains on the photosensitive drum 2 passing through the separation claw 9, the residual toner is collected by the cleaning unit 11 and is exposed by the pre-charging exposure unit 1
2 exposes the cleaned photoreceptor drum 2 with uniform light to eliminate / uniform the residual potential and prepare for the next charging.

The recycling pipe 6 is a pipe-shaped member provided with a screw for transporting toner therein, and connects the cleaning unit 11 to the developing unit 5 to remove the toner from the surface of the photosensitive drum 2 to remove the toner. Is sent to the developing unit 5. The toner sent to the developing unit 5 by the recycling pipe 6 is used again for development.

The drum drive motor 40 (drive means) starts and stops rotation under the control of the control means 13.

Next, the structure of the cleaning unit 11 will be described in detail with reference to FIGS. FIG. 3 is a front sectional view of the cleaning unit 11, and FIG. 4 is a sectional view showing a IV-IV section of FIG.

The cleaning unit 11 has a housing 14, a brush roller 16, toner conveying means 17, and a blade 18 as a cleaning member.
Is pressed and contacted (contacted) with the surface of the photosensitive drum 2 to scrape off the residual toner, and the scraped-off residual toner once rides on the brush roller 16 and falls into the screw 17 a of the toner conveying means 17. The screw 17a is rotated by a drive mechanism (not shown) to collect the dropped toner, and the collected toner is sent to the developing unit 5 again through the recycling pipe 6, and is accumulated in the developing unit 5. The toner is mixed with the mixed toner, stirred together, and reused for image formation.

The blade 18 is sandwiched and fixed by a blade holder 18a composed of two pieces of L-shaped brackets, and the blade holder 18a is fixed to two holder side plates 22a of the holder body 22. The holder body 22
It has a holder top plate 22b and a holder back plate 22c that are continuous with the holder side plate 22a, and a rotating shaft 23 projects from both sides of the holder top plate 22b. Since the rotating shaft 23 is rotatably supported by both side plates 14 a of the housing 14, the holder main body 22 is moved in two directions as shown by an arrow C in FIG.
In the direction.

The weight plate 2 is provided on the holder back plate 22c.
4 is locked, and the weight plate 24 is
2 and the blade 18 are given a rotational moment about the rotation shaft 23, and the tip of the blade 18 is moved to the photosensitive drum 2.
The surface is adjusted so that it comes in contact with the surface at a constant pressure.

One end of the rotating shaft 23 penetrates through the side plate 14a and is connected to a cam mechanism 25 as load adjusting means. The cam mechanism 25 is fixed to an end of the rotating shaft 23 to form a follower, a cam 27 for vertically moving the arm 26 to rotate the rotating shaft 23, and a shaft 27a. A driven gear 28 for transmitting a rotational force to the cam 27; and a driving gear 3 connected to the driven gear 28 via an idle gear 29.
0, and a cam drive motor 31 that transmits a rotational force in a predetermined direction to the drive gear 30. Cam drive motor 3
1 controls the cam mechanism 25 under the control of the control means 13, and the pressure (contact load) at the time of contact between the blade 18 and the photosensitive drum 2 is determined by the degree to which the cam 27 pushes up the arm 26. Although the degree of bending of the blade 18 changes when the contact load changes, the bending of the blade 18 is omitted in FIGS. 3 and 4.

Next, adjustment of the contact load by the cam mechanism 25 will be described with reference to FIG. FIG. 5 is a schematic view showing a part of the cleaning unit 11, and FIG.
3B shows a state where the contact loads applied to the photosensitive drum 2 and the blade 18 are different. Here, as a method of switching the contact load according to the usage history of the photoconductor, a high contact load (K ₁ ) is provided while the hard coat layer is provided, and the entire hard coat layer disappears and the photosensitive layer is exposed. After that, an example of switching to a low contact load (K ₂ ) will be described.

In order to adjust the contact load of the blade on the photosensitive drum 2 in the photosensitive drum 2 (time 0 to t ₁ ) in which the wear amount of the photosensitive member is small and the hard coat layer is present, the control of the control means 13 is performed. The cam drive motor 31 supplies the drive based on the rotation to rotate the cam 27, and the arm 26 and the cam 27 are brought into a non-contact state as shown in FIG. Arm 2
When the cam 6 and the cam 27 are in a non-contact state, the weight of the weight plate 24 is applied to the holder main body 22, so that the holder main body 22
Rotates about the rotation shaft 23 in a direction approaching the photosensitive drum 2 (arrow B1), and the blade 18
Contact strongly. The contact load of the blade 18 thus contacted to the photosensitive drum 2 does not cause image deletion,
The high contact load K ₁ (high contact load K ₁ ) suitable for sufficiently cleaning the hard coat layer.

Next, the blade 18 comes into contact with the photosensitive drum 2 in a state where the hard coat layer of the photosensitive drum 2 is worn out and completely disappeared, and the lower photosensitive layer is exposed (time t _{1 to} t ₂ ). The adjustment of the load will be described.

After the hard coat layer is depleted and removed,
FIG. 5B shows the state of the contact load when the blade 18 contacts the photosensitive drum 2. The cam drive motor 31 supplies a drive to rotate the cam 27, and the cam 27 rotates to push up the arm 26 against the load applied by the weight plate 24. According to the rotation of the arm 26,
The holder main body 22 rotates in a direction (arrow B <b> 2) in which the holder main body 22 is separated from the photosensitive drum 2. The rotation of the cam drive motor 31 is set to stop within a range where the contact between the blade 18 and the photosensitive drum 2 is maintained. At this time, blade 1
Although 8 is in contact with the photosensitive drum 2, contact load between the photosensitive drum 2 is adjusted to a low load K ₂ than the high contact load of above (low contact load K _2). Even with a low contact load, the photosensitive layer can be sufficiently cleaned because it has softer physical properties than the hard coat layer, and the depletion speed is reduced as compared with the case of a high contact load.

The above-mentioned cam mechanism 25 as load adjusting means
, The contact load of the blade 18 on the photosensitive drum 2 can be switched between a high contact load (FIG. 5A) and a low contact load (FIG. 5B). I can do it.

The high contact load K ₁ , the low contact load K ₂ , and the amount of wear D at the limit of use of the photoreceptor are design values that should be appropriately changed depending on the physical properties and combinations of the photoreceptor and the blade. If the high contact load K ₁ , the low contact load K ₂ , and the wear amount D at the use limit of the photoconductor are determined, the photosensitive layer exposure start point t ₁ and the time t ₂ to reach the use limit D are naturally determined. Value. By inputting these values into the control means 13 in advance as set values, it is possible to adjust the contact load by the load adjusting means.

The switching of the contact load by the load adjusting means is not limited to the case of FIG.
It is performed according to.

The "use history of the photoreceptor" is an index indicating how much the photoreceptor has been worn or deteriorated. For example, the entire hard coat layer of the photoreceptor is worn out and disappears, Whether the layer has been exposed, whether the current value has reached a predetermined number of image formations (the number of copies in a copying machine), or whether the current value has to be changed over a predetermined photoconductor usage time (total photoconductor drum). Rotation time), etc.

Regarding the physical properties of the hard coat layer and the photosensitive layer, for example, a detector capable of measuring the reflectance of light is provided near the photosensitive drum 2 and the point at which the reflectance significantly changes is determined by the hard coat layer. When it is determined that all of the layers have been worn, feedback is provided to the control means 13 to switch to a preset contact load by operating the cam mechanism 25 as a load adjusting means, or in a certain image forming apparatus, When the number of image formations in which all the coat layers disappear or the usage time of the photoconductor is substantially constant, the predetermined number of image formations or the predetermined photoconductor usage time in which all the hard coat layers obtained as an empirical rule are obtained May be set in advance, and when these are detected, the cam mechanism 25 may be operated so as to switch the contact load.

As for the counter, a means for measuring the number of image formation such as a copy counter is provided, and when the predetermined number of image formations set as the timing for switching the contact load is reached, the copy counter feeds back to the control means 13. Then, the cam mechanism 25 may be operated so as to switch to the preset contact load.

For the ON / OFF of the drum drive motor 40 (drive means), a means for measuring the rotation time of the photosensitive drum (the control means 13 may also serve as this means) applies a contact load. When the use time of the predetermined photoconductor set in advance as the switching timing is reached,
The cam mechanism 25 may be operated to switch to a preset contact load.

The blade used in the image forming apparatus of the present invention has a temperature of 25 ± 0.2 ° C. and a humidity of 50 ± 5.
% RH after leaving it in an environment of 40% RH
% Is preferable. More preferably 20% or more
40%. If it exceeds 40%, the blade is likely to be turned up, and if it is less than 20%, the cleaning performance deteriorates. The rebound resilience is a value measured based on the vulcanized rubber physical test method of JIS K6301.

By controlling the rebound resilience of the blade, the blade does not turn over for a long time,
It has become possible to maintain stable cleaning performance. As a result, it is possible to provide a highly durable electrophotographic image forming method which has less wear and excellent cleaning performance.

Urethane rubber, silicone rubber, fluorine rubber, chloropyrene rubber, butadiene rubber and the like are known as the material of the blade. Among them, urethane rubber has excellent wear characteristics as compared with other rubbers. Is particularly preferred in that For example, urethane rubber obtained by reacting and curing a polycaprolactone ester and a polyisocyanate described in JP-A-59-30574 is preferable.

Further, the blade as a cleaning member used in the present invention can further prevent the blade from turning up and abrasion by providing a coating layer having a smaller frictional resistance than the material of the blade itself, thereby improving the cleaning performance. Can also be maintained stably. Cleaning member having this coating layer,
In particular, the effect is high when combined with a hard coat photoreceptor. Examples of the coating material include fluororesin, silicone oil, zinc stearate, etc. Among them, fluororesin is most preferable. The method of providing the coating layer may be a known method, but spray coating is preferred.

Next, an organic photoreceptor provided with a resin layer containing a siloxane-based resin having a crosslinked structure used in the present invention (hereinafter referred to as a hard coat photoreceptor) will be described. The hard coat photoreceptor has a resin layer (hard coat layer) which has a structural unit having charge transport performance and contains a siloxane-based resin having a crosslinked structure. A siloxane-based resin having a structural unit having charge transport performance and having a favorable structure is produced by a known method, that is, using an organosilicon compound having a hydroxyl group or a hydrolyzable group. The organosilicon compound is represented by the following general formulas (A) to (D).

[0052]

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In the formula, R _{1 to} R ₆ represent an organic group in which carbon is directly bonded to silicon in the formula, and Z _{1 to} Z ₄ represent a hydroxyl group or a hydrolyzable group.

When Z _{1 to} Z ₄ in the above general formula are hydrolyzable groups, methoxy, ethoxy,
Examples include a methylethylketoxime group, a diethylamino group, an acetoxy group, a propenoxy group, a propoxy group, a butoxy group, and a methoxyethoxy group. Examples of the organic group in which carbon is directly bonded to silicon represented by R _{1 to} R ₆ include alkyl groups such as methyl, ethyl, propyl and butyl, aryl groups such as phenyl, tolyl, naphthyl and biphenyl, and γ-glycidyl. Epoxy-containing groups such as xypropyl and β- (3,4-epoxycyclohexyl) ethyl;
(Meth) acryloyl groups such as acryloxypropyl and γ-methacryloxypropyl, hydrous groups such as γ-hydroxypropyl and 2,3-dihydroxypropyloxypropyl, vinyl groups such as vinyl and propenyl, and γ-mercaptopropyl , Amino-containing groups such as γ-aminopropyl, N-β (aminoethyl) -γ-aminopropyl, γ-chloropropyl, 1,1,1-trifluorofluoropropyl, nonafluorohexyl, perfluoro Examples include a halogen-containing group such as octylethyl, and other nitro and cyano-substituted alkyl groups. Also, R ₁
-R ₆ may have the same or different organic groups.

In general, when the number n of hydrolyzable groups bonded to silicon atoms of the organosilicon compound used as a raw material of the siloxane-based resin is 1, the polymerization reaction of the organosilicon compound is suppressed. You. n is 2, 3 or 4
In the case of (3), the polymerization reaction is likely to occur.
It is possible to advance the crosslinking reaction to a high degree. Therefore, by controlling these, it is possible to control the preservability of the obtained coating layer liquid, the hardness of the coating layer, and the like.

As a raw material of the siloxane-based resin, a hydrolyzed condensate obtained by hydrolyzing the organosilicon compound under acidic conditions or basic conditions and oligomerizing or polymerizing the same can also be used.

As described above, the siloxane-based resin is obtained by reacting a monomer, oligomer or polymer having a siloxane bond in a chemical structural unit in advance (including a hydrolysis reaction, a reaction in which a catalyst or a cross-linking agent is added). It means a resin that has formed and cured a three-dimensional network structure. That is, it means a siloxane-based resin having a cross-linked structure formed by promoting a siloxane bond by a hydrolysis reaction and subsequent dehydration condensation of an organosilicon compound having a siloxane bond to form a three-dimensional network structure.

The siloxane-based resin may be a resin in which colloidal silica having a hydroxyl group or a hydrolyzable group is contained, and silica particles are incorporated in a part of the crosslinked structure.

The siloxane-based resin having a structural unit having a charge transporting property and having a crosslinked structure according to the present invention is a chemical structure having a characteristic of exhibiting electron or hole drift mobility (= a structure having a charge transporting property). (Unit) in a siloxane-based resin as a partial structure.
Specifically, the siloxane-based resin having a structural unit having a charge transporting property of the present invention and having a crosslinked structure includes a compound generally used as a charge transporting substance (hereinafter, also referred to as a charge transporting compound or CTM). It has a partial structure in the siloxane-based resin.

The above-mentioned structural unit having charge transport performance is a structural unit exhibiting the property of having electron or hole drift mobility, or a charge transporting compound residue. Another definition is Time- It can also be expressed as a structural unit or a charge-transporting compound residue from which a detection current due to charge transport can be obtained by a known method capable of detecting charge-transporting performance such as the Of-Flight method.

A charge transporting compound capable of forming a structural unit having charge transporting ability in a siloxane-based resin by reaction with an organosilicon compound will be described below.

For example, hole transport type CTM: xazole, oxadiazole, thiazole, triazole, imidazole, imidazolone, imidazoline, bisimidazolidine, styryl, hydrazone, benzidine, pyrazoline,
Stilbene compound, amine, oxazolone, benzothiazole, benzimidazole, quinazoline, benzofuran, acridine, phenazine, aminostilbene, poly-N-vinylcarbazole, poly-1-vinylpyrene,
A chemical structure such as poly-9-vinylanthracene is contained as a partial structure of the siloxane-based resin.

On the other hand, electron transport type CTMs include succinic anhydride, maleic anhydride, phthalic anhydride, pyromellitic anhydride, melitic anhydride, tetracyanoethylene, tetracyanoquinodimethane, nitrobenzene, dinitrobenzene, trinitrobenzene, Tetranitrobenzene, nitrobenzonitrile, picryl chloride, quinone chlorimide, chloranil, bromanyl, benzoquinone, naphthoquinone, diphenoquinone, tropoquinone, anthraquinone, 1-chloroanthraquinone, dinitroanthraquinone, 4-nitrobenzophenone, 4,4'-dinitrobenzophenone, 4-nitrobenzalmalonedinitrile, α-cyano-β- (p-cyanophenyl) -2-
(P-chlorophenyl) ethylene, 2,7-dinitrofluorene, 2,4,7-trinitrofluorenone, 2,
4,5,7-tetranitrofluorenone, 9-fluorenylidenedicyanomethylenemalononitrile, polynitro-9-fluoronylidenedicyanomethylenemalonodinitrile, picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, 3, Chemical structures such as 5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitrosalicylic acid, phthalic acid and melitic acid are contained as partial structures of the siloxane-based resin.

In the present invention, the structural unit having a preferable charge transporting property is a residue of a commonly used charge transporting compound as described above, and has the following structure via a carbon atom or a silicon atom constituting the charge transporting compound. It is bonded to the linking atom or linking group represented by Y in the formula, and is contained in the siloxane-based resin via Y.

[0065]

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In the formula, X is a structural unit having charge transporting ability, a group bonding to Y in the formula via a carbon atom or a silicon atom constituting the imparting group, and Y is an adjacent bonding atom (Si And divalent or higher atoms or groups excluding C).

However, when Y is an atom having three or more valences, S in the formula
The bond of Y other than i and C is bonded to any constituent atom in the curable resin capable of bonding or has a structure (group) connected to another atom or molecular group.

In the above formula, an oxygen atom (O), a sulfur atom (S), and a nitrogen atom (N) are particularly preferable as the Y atom.

Here, when Y is a nitrogen atom (N), the linking group is represented by -NR-. (R is a hydrogen atom or a monovalent organic group.) The structural unit X having charge transporting performance is shown as a monovalent group in the formula, but the charge transporting compound to be reacted with the siloxane-based resin is 2 When it has two or more reactive functional groups, it may be bonded as a divalent or higher valent crosslink group in the curable resin, or may be bonded simply as a pendant group.

The above-mentioned atoms, ie, the atoms of O, S, and N, are formed by the reaction of a hydroxyl group, a mercapto group, or an amine group introduced into a compound having a charge transporting ability with an organic silicon compound having a hydroxyl group or a hydrolyzable group. It is a linking group that is formed and incorporates a structural unit having charge transport performance into the siloxane-based resin as a partial structure.

Next, the charge transporting compound having a hydroxyl group, a mercapto group, an amine group, and an organic silicon-containing group in the present invention will be described.

The charge transporting compound having a hydroxyl group is
It is a charge transport substance having a commonly used structure and a compound having a hydroxyl group. That is, typically, a charge transporting compound represented by the following general formula that can form a resin layer by bonding to a curable organosilicon compound can be exemplified, but is not limited to the following structure. Any compound having a charge transporting ability and a hydroxyl group may be used.

X- (R ₇ -OH) _m wherein X: Structural unit having charge transport performance R ₇ : Single bond, substituted or unsubstituted alkylene group, arylene group m: Integer of 1 to 5 Among them, the following are typical ones. For example, a triarylamine-based compound has a triarylamine structure such as triphenylamine as a structural unit having charge-transporting property = X, and alkylene extended through a carbon atom constituting X or extended from X; A compound having a hydroxyl group via an arylene group is preferably used.

1. Triarylamine compounds

[0075]

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2. Hydrazine compounds

[0077]

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3. Stilbene compounds

[0079]

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4. Benzidine compound

[0081]

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5. Butadiene compound

[0083]

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6. Other compounds

[0085]

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Next, a synthesis example of a charge transporting compound having a hydroxyl group will be described. Synthesis of Exemplified Compound T-1

[0087]

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Step A In a four-headed kolben equipped with a thermometer, a condenser, a stirrer, and a dropping funnel, 49 g of the compound (1) and 184 phosphorus oxychloride were added.
g was added and dissolved by heating. 117 g of dimethylformamide was gradually added dropwise from the dropping funnel.
The mixture was kept at ９５95 ° C. and stirred for about 15 hours. Next, the reaction solution was gradually poured into a large excess of warm water, and then slowly cooled while stirring.

The precipitated crystals were filtered and dried, and then purified by adsorption of impurities using silica gel or the like and recrystallization with acetonitrile to obtain Compound (2). Yield 30
g.

Step B 30 g of compound (2) and 100 ml of ethanol were charged into a kolben and stirred. After gradually adding 1.9 g of sodium borohydride, the solution was kept at 40 to 60 ° C. and stirred for about 2 hours. Next, the reaction solution was gradually poured into about 300 ml of water, and stirred to precipitate crystals. After filtration, the resultant was sufficiently washed with water and dried to obtain a compound (3). The yield was 30 g.

Synthesis of Exemplified Compound S-1

[0092]

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Step A In a 300 ml kolben equipped with a thermometer and a stirrer, add C
Then, 30 g of u, 60 g of K ₂ CO ₃ , 8 g of compound (1) and 100 g of compound (2) were added, and the mixture was heated to about 180 ° C. and stirred for 20 hours. After cooling, the mixture was filtered and purified by column to obtain 7 g of compound (3).

Step B A 100 ml Kolben equipped with a thermometer, a dropping funnel, an argon gas introducing device and a stirrer was set to an argon gas atmosphere, and 7 g of the compound (3), 50 ml of toluene, and 3 g of phosphoryl chloride were added thereto. While stirring at room temperature, D
2 g of MF was slowly added dropwise, and then the temperature was raised to about 80 ° C. and the mixture was stirred for 16 hours. The mixture was poured into warm water of about 70 ° C. and cooled. This was extracted with toluene, and the extract was washed with water until the pH of the water reached 7. After drying over sodium sulfate, the mixture was concentrated and purified by column to obtain 5 g of compound (4).

Step C 100 ml with an argon gas introducing device and a stirring device
1.0 g of t-BuOK and 60 ml of DMF were charged into the Kolben, and the atmosphere was changed to an argon gas atmosphere. Compound (4)
2.0 g and 2.2 g of the compound (5) were added, and the mixture was stirred at room temperature for 1 hour. This was poured into a large excess of water, extracted with toluene, the extract was washed with water, dried over sodium sulfate,
After concentration, column purification was performed, and 2.44 g of compound (6) was obtained.
I got

Step D Toluene was charged into a 100 ml kolben equipped with a thermometer, a dropping funnel, an argon gas introduction device, and a stirring device, and an argon gas atmosphere was established. To this, 15 ml of a hexane solution of n-BuLi (1.72 M) was added, and the mixture was heated to 50 ° C. To this, 2.44 g of compound (6) was added in 30 ml of toluene.
The dissolved liquid was added dropwise, and the mixture was stirred at 50 ° C. for 3 hours. After cooling to −40 ° C., 8 ml of ethylene oxide was added, the temperature was raised to −15 ° C., and the mixture was stirred for 1 hour.
Thereafter, the temperature was raised to room temperature, 5 ml of water was added, and ether 2 was added.
After extraction with 00 ml, the extract was washed with saturated saline.
After washing the washing solution to pH, it was dried over sodium sulfate, concentrated and purified by column to obtain 1.0 g of compound (7).

Next, specific examples of the charge transporting compound having a mercapto group are shown below. The charge transporting compound having a mercapto group is a charge transporting substance having a commonly used structure and a compound having a mercapto group.
That is, typically combined with a curable organosilicon compound,
Examples of the charge-transporting compound represented by the following general formula capable of forming a resin layer include, but are not limited to, the following structure, having a charge-transporting ability, and having a mercapto group. Any compound may be used.

X- (R ₈ -SH) _m wherein X: Structural unit having charge transporting ability R ₈ : Single bond, substituted or unsubstituted alkylene, arylene group m: an integer of 1 to 5 The typical ones are as follows.

[0099]

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Further, the charge transporting compound having an amino group will be described. The charge transporting compound having an amino group is a charge transporting substance having a commonly used structure and a compound having an amino group. That is, typically, a charge transporting compound represented by the following general formula that can form a resin layer by bonding to a curable organosilicon compound can be exemplified, but is not limited to the following structure. ,
Any compound having charge transporting ability and having an amino group may be used.

X- (R ₉ -NR ₁₀ H) _m wherein X: Structural unit having charge transporting ability R ₉ : Single bond, substituted or unsubstituted alkylene, substituted or unsubstituted arylene group R ₁₀ : hydrogen Atom, substituted or unsubstituted alkyl group, substituted or unsubstituted aryl group m: an integer of 1 to 5 Among them, the following are typical examples.

[0102]

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Among the charge transporting compounds having an amino group, in the case of a primary amine compound (—NH ₂ ), two hydrogen atoms may react with an organosilicon compound and be linked to a siloxane structure. In the case of a secondary amine compound (—NHR ₁₀ ), one hydrogen atom reacts with the organosilicon compound, and R ₁₀ may be a group that remains as a branch or a group that causes a cross-linking reaction, and includes a charge transport material. It may be a compound residue.

Further, the charge transporting compound having a silicon atom-containing group will be described. The charge transporting compound having a silicon atom-containing group is a charge transporting substance having the following structure. This compound can also combine with the curable organosilicon compound to form a resin layer.

[0105] X - in _{- (Y-Si (R 11} ) 3-a (R 12) a) n -type, X is a group containing a structural unit having charge transportability, R ₁₁ is a hydrogen atom, a substituted or R ₁₂ represents a hydrolyzable group or a hydroxyl group; Y represents a substituted or unsubstituted alkylene group or an arylene group; a represents an integer of 1 to 3, and n represents an integer.

Among them, the following are typical ones. Raw materials for forming the siloxane-based resin:
From the general formulas (A) to (D) (hereinafter referred to as (A) to (D)), the composition ratio is: organosilicon compound: (A) + (B)
It is preferable to use 0.05 to 1 mol of the component (C) + (D) based on 1 mol of the component.

When the colloidal silica (E) is added, 1 to 30 parts by mass of (E) is used based on 100 parts by mass of the components (A) + (B) + (C) + (D). Is preferred.

The addition amount of the reactive charge transporting compound (F) capable of forming a resin layer by reacting with the above-mentioned organosilicon compound or colloidal silica is the above (A) + (B)
It is preferable to use 1 to 500 parts by mass of (F) based on 100 parts by mass of the total of + (C) + (D) components. (A)
When the + (B) component is used outside the above range,
When the amount of the components (A) and (B) is small, the siloxane resin layer has too low a crosslinking density and insufficient hardness. Also, (A) +
If the component (B) is too large, the crosslink density is too high and the hardness is sufficient, but a brittle resin layer is formed. Excess or deficiency of the colloidal silica component of the component (E) has the same tendency as that of the component (A) + (B). On the other hand, when the amount of the component (F) is small, the charge transporting ability of the siloxane resin layer is small, causing a decrease in sensitivity and an increase in residual charge. When the amount of the component (F) is large, the film strength of the siloxane resin layer tends to be weak. Be looked at.

The siloxane-based resin having a structural unit having charge transporting ability and having a crosslinked structure according to the present invention is prepared by adding a catalyst or a crosslinking agent to a monomer, oligomer or polymer having a siloxane bond in the structural unit in advance. A bond may be formed to form a three-dimensional network structure, or a siloxane bond may be promoted by a hydrolysis reaction and subsequent dehydration condensation to form a three-dimensional network structure from monomers, oligomers, and polymers.

In general, a three-dimensional network structure can be formed by a condensation reaction of a composition containing alkoxysilane or a composition containing alkoxysilane and colloidal silica.

Examples of the catalyst for forming the three-dimensional network structure include alkali metal salts of organic carboxylic acids, nitrous acid, sulfurous acid, aluminate, carbonic acid and thiocyanic acid, and organic amine salts (tetramethylammonium hydroxide, tetramethylammonium hydroxide). Ammonium acetate), tin organic acid salts (stannas octoate, dibutyltin diacetate, dibutyltin dilaurate, dibutyltin mercaptide, dibutyltin thiocarboxylate, dibutyltin malate), aluminum, zinc octenoic acid, naphthenate, An acetylacetone complex compound is exemplified.

Further, it is preferable to add an antioxidant to the resin layer in the present invention. Antioxidants have a function of inhibiting a radical chain that traps radicals generated by heat, light, etc., for example, a compound having a chemical structure of hindered phenol or hindered amine or a chemical structure having a function of decomposing peroxides. And a compound group having a chemical structure such as thioether and phosphite. Of these, hindered phenols,
Hindered amine antioxidants are highly effective in preventing fogging and image blurring at high temperature and high humidity.

The content of the hindered phenol or hindered amine antioxidant in the resin layer is 0.01 to 1
% By mass is preferred. When the content is less than 0.01% by mass, there is no effect on fogging and image blur at high temperature and high humidity, and when the content is more than 10% by mass, the charge transport ability in the resin layer is reduced, and the residual potential tends to increase, In addition, a decrease in film strength occurs.

The antioxidant may be contained in the lower charge generation layer, charge transport layer, intermediate layer and the like, if necessary. The amount of the antioxidant added to these layers is preferably 0.01 to 10% by mass with respect to each layer.

Here, hindered phenol refers to compounds having a branched alkyl group at the ortho position to the hydroxyl group of the phenol compound and derivatives thereof (however, the hydroxyl group may be modified to alkoxy).

Examples of the hindered amine include compounds having an organic group represented by the following structural formula.

[0117]

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In the formula, R ₁₃ is a hydrogen atom or a monovalent organic group,
R ₁₄ , R ₁₅ , R ₁₆ and R _{17 each} represent an alkyl group, and R ₁₈ represents a hydrogen atom, a hydroxyl group or a monovalent organic group.

As the antioxidant having a hindered phenol partial structure, for example, JP-A-1-118137 (P.
7 to P14), but the present invention is not limited thereto.

Examples of the antioxidant having a hindered amine partial structure include, for example, JP-A-1-118138 (P7-
The compounds described in P9) may also be mentioned, but the present invention is not limited thereto.

As the organic phosphorus compound, for example, there are the following compounds represented by the general formula RO-P (OR) -OR. Here, R represents a hydrogen atom, a substituted or unsubstituted alkyl group, alkenyl group or aryl group.

Examples of the organic sulfur compounds include, for example, the following compounds represented by the general formula RSR. Here, R represents a hydrogen atom, a substituted or unsubstituted alkyl group, alkenyl group or aryl group.

The following are various typical compounds.

[0124]

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[0125]

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[0126]

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[0127]

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[0128]

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[0129]

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Examples of the antioxidants that have been commercialized include the following compounds, for example, “Irganox 107
6, Irganox 1010, Irganox 1098, Irganox 245, Irganox 1330, Irganox 3114, Irganox 1076, 3,5-di-t-butyl-4 −
Hydroxybiphenyl or more hindered phenols,
"Sanol LS2626", "Sanol LS765"
"Sanol LS2626", "Sanol LS770",
“Sanol LS744”, “Tinuvin 144”, “Tinuvin 622LD”, “Mark LA57”, “Mark LA”
67 "," Mark LA62 "," Mark LA68 ",
"Mark LA63" or more is a hindered amine type.

<Organic Fine Particles> The organic fine particles have a volume average particle diameter of 0.05 to 10 μm, preferably 0.1 to 5 μm.
And 0.01 to 50% by mass is added to the outermost resin layer of the photoconductor. Examples of the organic fine particles include polytetrafluoroethylene, polychlorotrifluoroethylene, polyvinylidene fluoride, polyfluoroethylene, polydichlorodifluoroethylene, tetrafluoroethylene-perfluoroalkylvinyl ether copolymer, and tetrafluoroethylene-hexafluoropropylene copolymer. Coalescing,
Fine particles of resin such as tetrafluoroethylene-ethylene copolymer, tetrafluoroethylene-hexafluoropropylene-perfluoroalkylvinyl ether copolymer or silicone resin, polyethylene, polypropylene, melamine, etc. Is preferred. The content of these organic fine particles in the resin layer is preferably set so that the coefficient of static friction of the elastic rubber blade applied to the present invention with respect to the photoreceptor is 1.0 or less. The coefficient of static friction is 1.0
By doing so, the turning of the cleaning blade is prevented, and the cleaning of the residual toner becomes easy.

The coefficient of static friction μ is usually HEI when the photosensitive member is in the form of a sheet, a flat plate or an endless belt.
Surface property tester (model HEIDON-1 manufactured by DON)
4).

However, the photosensitive drum incorporated in the electrophotographic image forming apparatus is mainly a photosensitive drum. In this case, the static friction coefficient μ is measured by measuring the rotational torque T (kg · cm) of the photosensitive drum. Required by

That is, the rotational torque T of the photosensitive drum itself
₁ (kg · cm) and the rotation torque T ₂ of the photosensitive drum with the blade cleaning member pressed against the load F (kg).
(Kg · cm) is measured and calculated by the following equation.

Static friction coefficient μ = (T ₂ −T ₁ ) / (F · γ) where γ is the radius (cm) of the photosensitive drum.

The layer structure of the electrophotographic photoreceptor of the present invention is not particularly limited, but may be a charge generation layer, a charge transport layer, or a charge generation / charge transport layer (a single layer having both functions of charge generation and charge transport). It is preferable to adopt a structure in which a photosensitive layer such as a photosensitive layer) and a resin layer of the present invention are coated thereon. Further, each of the charge generation layer, the charge transport layer, or the charge generation / charge transport layer may be composed of a plurality of layers.

Examples of the charge generation material (CGM) contained in the photosensitive layer of the present invention include phthalocyanine pigments, polycyclic quinone pigments, azo pigments, perylene pigments, indigo pigments, and the like.
Quinacridone pigments, azurenium pigments, squarylium dyes, cyanine dyes, pyrylium dyes, thiopyrylium dyes, xanthene dyes, triphenylmethane dyes, styryl dyes, and the like.
In M), a layer is formed alone or together with a suitable binder resin.

The charge transport material (C) contained in the photosensitive layer
TM) includes, for example, oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives, imidazolone derivatives, imidazoline derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds, benzidine compounds, pyrazoline derivatives, stilbenes Compound,
Amine derivatives, oxazolone derivatives, benzothiazole derivatives, benzimidazole derivatives, quinazoline derivatives, benzofuran derivatives, acridine derivatives, phenazine derivatives, aminostilbene derivatives, poly-N-vinylcarbazole, poly-1-vinylpyrene, poly-9-vinylanthracene, etc. These charge transport materials (CTM) are usually used to form a layer together with a binder.

The binder resin contained in the charge-generating layer (CGL) and the charge-transporting layer (CTL) in the case of the single-layered photosensitive layer and the laminated structure is a polycarbonate resin, a polyester resin, a polystyrene resin, a methacrylic resin,
Acrylic resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl butyral resin, polyvinyl acetate resin, styrene-butadiene resin, vinylidene chloride-acrylonitrile copolymer resin, vinyl chloride-maleic anhydride copolymer resin, urethane resin, silicon resin,
Epoxy resin, silicon-alkyd resin, phenol resin, polysilane resin, polyvinyl carbazole and the like can be mentioned.

In the present invention, the ratio between the charge generating substance and the binder resin in the charge generating layer is from 1:10 to 1 by mass.
0: 1 is preferred. The thickness of the charge generation layer is preferably 5 μm or less, and particularly preferably 0.05 to 2 μm.

The charge transport layer is formed by dissolving the charge transport material and the binder resin in an appropriate solvent, and applying and drying the solution. The mixing ratio of the charge transport material and the binder resin is preferably from 10: 1 to 1:10 by mass.

The thickness of the charge transport layer is usually from 5 to 50 μm, particularly preferably from 10 to 40 μm. When a plurality of charge transport layers are provided, the thickness of the upper layer of the charge transport layer is 10
μm or less, and preferably smaller than the total thickness of the charge transport layer provided below the charge transport layer.

The siloxane-based resin layer of the hard coat photoreceptor used in the present invention may serve also as the charge transport layer when the resin layer is a charge transport layer. Although it may be a layer, it is preferably provided as a resin layer separate from these on a photosensitive layer such as a charge transport layer, a charge generation layer, or a single-layer type charge generation / transport layer. In this case, an adhesive layer may be provided between the photosensitive layer and the resin layer of the present invention. Further, a thinner surface layer may be provided on the resin layer for the purpose of improving the surface characteristics of the electrophotographic photosensitive member.

Next, the conductive support of the photoreceptor used in the present invention includes: 1) a metal plate such as an aluminum plate or a stainless plate; 2) a support such as paper or a plastic film.
A thin metal layer such as aluminum, palladium, or gold provided by lamination or vapor deposition. 3) On a support such as paper or plastic film,
Examples thereof include those in which a layer of a conductive compound such as a conductive polymer, indium oxide, or tin oxide is provided by coating or vapor deposition.

The material of the conductive support used in the present invention is mainly aluminum, copper, brass, steel,
A belt-shaped or drum-shaped metal material such as stainless steel or another plastic material is used. Among them, aluminum excellent in cost, workability and the like is preferably used, and a thin-walled cylindrical aluminum tube usually formed by extrusion or drawing is often used.

The conductive support may have a surface on which a sealed alumite film is formed.

The shape of the support may be a drum shape, a sheet shape, or a belt shape, and is preferably a shape optimized for the applied electrophotographic apparatus.

The solvent or dispersion medium used for producing the photoreceptor of the present invention includes n-butylamine, diethylamine, ethylenediamine, isopropanolamine, triethanolamine, triethylenediamine, N, N-dimethylformamide, acetone, methylethylketone,
Methyl isopropyl ketone, cyclohexanone, benzene, toluene, xylene, chloroform, dichloromethane, 1,2-dichloroethane, 1,2-dichloropropane, 1,1,2-trichloroethane, 1,1,1-trichloroethane, trichloroethylene, tetrachloroethane, Tetrahydrofuran, dioxolan, dioxane,
Methanol, ethanol, butanol, isopropanol, ethyl acetate, butyl acetate, dimethyl sulfoxide,
Methyl cellosolve and the like. Although the present invention is not limited to these, dichloromethane, 1,2-dichloroethane, methyl ethyl ketone and the like are preferably used. In addition, these solvents can be used alone or as a mixed solvent of two or more kinds.

Next, as a coating method for producing the photoreceptor used in the present invention, coating methods such as dip coating, spray coating, and circular amount control type coating are used.
The coating process on the resin layer side of the photosensitive layer does not dissolve the lower layer film as much as possible, and in order to achieve uniform coating process, coating process such as spray coating or circular volume control type (a typical example is a circular slide hopper type). Preferably, a method is used. The spray coating is described in, for example, JP-A-3-9025.
No. 0 and JP-A-3-269238, and the circular amount control type coating is described in, for example, JP-A-58-1983.
It is described in detail in JP-A-189061.

The photoreceptor used in the present invention has a temperature of 50.degree.
It is preferable to heat and dry at a temperature of 0 ° C. By this heating and drying, the remaining coating solvent can be reduced, and the curable resin layer can be sufficiently cured.

In the photoreceptor used in the present invention, an intermediate layer having a barrier function is preferably provided between the conductive support and the photosensitive layer.

Examples of the material for the intermediate layer include casein, polyvinyl alcohol, nitrocellulose, ethylene-acrylic acid copolymer, polyvinyl butyral, and phenol resin polyamides (nylon 6, nylon 66, nylon 610, copolymer nylon, alkoxymethyl). And an intermediate layer using polyurethane, gelatin, and aluminum oxide, or a curable intermediate layer using a metal alkoxide, an organic metal chelate, or a silane coupling agent as disclosed in JP-A-9-68870. The thickness of the intermediate layer is preferably from 0.1 to 10 μm, particularly preferably from 0.1 to 10 μm.
5 μm is preferred.

In the photoreceptor used in the present invention, a coating may be further provided between the support and the intermediate layer so as to compensate for surface defects of the support. A conductive layer can be provided for the purpose of preventing the occurrence of interference fringes. This conductive layer,
It can be formed by applying and drying a solution in which conductive powder such as carbon black, metal particles or metal oxide particles is dispersed in a suitable binder resin. The thickness of the conductive layer is 5
40 μm is preferable, and particularly preferably 10 to 30 μm.

The photoreceptor used in the present invention can be applied to general electrophotographic devices such as copiers, laser printers, LED printers, and liquid crystal shutter printers.
It can be widely applied to devices such as recording, light printing, plate making, and facsimile.

[0155]

EXAMPLES (Example 1) (Preparation of Organic Photoconductor-1) Polyamide resin (Amilan C)
(M-8000: manufactured by Toray Industries, Inc.) 60 g was dissolved and dispersed in 1600 ml of methanol to prepare an intermediate layer composition solution, which was applied by dip coating onto a washed cylindrical aluminum substrate. A layer was formed.

60 g of Y-type titanyl phthalocyanine;
700 g of a silicone resin solution (KR5240, 15%
Xylene-butanol solution: manufactured by Shin-Etsu Chemical Co., Ltd.)
A coating composition solution composed of 0 ml of 2-butanone was mixed and dispersed for 10 hours using a sand mill to prepare a charge generation layer coating solution. This charge generation layer coating solution was applied onto the intermediate layer by dip coating to form a charge generation layer having a thickness of 0.2 μm.

200 g of the charge transport material (D1), 30
0 g of bisphenol Z-type polycarbonate (Iupilon Z300: manufactured by Mitsubishi Gas Chemical Company) and 2000 ml of 1,2-dichloroethane were mixed and dissolved to prepare a charge transport layer coating solution. The charge transport coating solution was applied on the charge generation layer by a dip coating method to form a charge transport layer having a thickness of 20 μm.

[0158] Molecular sieve 4A was added to 10 parts by mass of a polysiloxane resin composed of 80 mol% of methylsiloxane units and 20 mol% of methyl-phenylsiloxane units, and left to stand for 15 hours to dehydrate. This resin was dissolved in 10 parts by mass of toluene, and 5 parts by mass of methyltrimethoxysilane and 0.2 parts by mass of dibutyltin acetate were added thereto to form a uniform solution. 6 parts by mass of dihydroxymethyltriphenylamine (Exemplified Compound T-1) was added thereto and mixed, and this solution was applied as a surface layer having a dry film thickness of 2 μm on the charge transport layer, and the solution was treated at 120 ° C. for 1 hour. The resultant was cured by heating to produce Organic Photoconductor 1 of the present invention.

[0159]

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(Image Forming Test) The above-mentioned organic photoreceptor-1 was mounted on the image forming apparatus shown in FIG. 1, and an endurance test of the photoreceptor (comparative experiment of a time to reach the use limit D) was performed. The graph of FIG. 6 shows the case of the present invention in which the contact load was switched according to the usage time of the photoconductor, and the graph of FIG. 7 shows the conventional case in which the contact load was not adjusted from the beginning to the end. .

First, FIG. 6 (the present invention) will be described. FIG. 6A shows the wear amount (vertical axis) of the photoconductor with respect to the usage time (horizontal axis) of the photoconductor, and FIG. 6B shows the relationship between the usage time of the photoconductor and the blade photoconductor with respect to the usage time (horizontal axis). Shows the contact load.

In the image forming apparatus of the present invention, the contact load at which no image flow occurs when the hard coat layer is exposed is set as a high contact load K _1, and the time t ₁ from the start of use of the photosensitive member. until maintained at this high contact load K ₁ (FIG. 6
(B)). The time t ₁ is a value designed in advance from various conditions of the photoconductor and the blade, and is a time at which the hard coat layer is expected to disappear and the photosensitive layer starts to be exposed (photosensitive layer exposure start point).

Next, when the use time of the photosensitive member reaches the photosensitive layer exposure start point t ₁ , the load adjusting means is operated by the control means as described above, and the contact load of the blade to the photosensitive member is reduced. switching to low contact load K _2. By switching to the low contact load K _2, is suppressed depletion speed of the photosensitive layer is exposed photosensitive member became loose depletion of inclination with respect to operating time. As a result, the amount of wear D at the limit of use of the photoconductor is obtained.
Time t ₂ to reach is directly compared with the case to maintain a high contact load K ₁ (see FIG. 7 of the prior art), it could be extended sufficiently.

[0164] Incidentally, as in FIG. 6, the start of use of the photosensitive member depletion speed (inclination) from (time zero) until use limit time t ₂ of the photosensitive member showed a graph becomes constant, limited to this Instead, it can be appropriately changed depending on the conditions of the photoconductor and the blade.

Next, FIG. 7 (conventional) will be described. Similarly, FIG. 7A shows the amount of wear of the photoconductor (vertical axis) with respect to the usage time (horizontal axis) of the photoconductor, and FIG. 7B shows the blade time with respect to the usage time of the photoconductor (horizontal axis). The abutment load on the photoconductor is shown.

When the photoreceptor is not worn out and the hard coat layer is exposed, an abutting load that does not cause image deletion when K is applied
₀ , which was not changed from the beginning to the end (FIG. 7)
(B)).

The photoreceptor depletes from its surface with the use time of the photoreceptor (time during which the photoreceptor drum rotates and rubs against the blade). This is the limit and must be replaced with a new photoconductor (FIG. 7A).

In FIG. 7 (a), the hard coat layer is present until the use time t ₁ , and the wear proceeds at a constant inclination. However, after the use time t ₁ , the hard coat layer is not completely worn out. After the lower photosensitive layer was exposed, the slope of the depletion became steep, reaching the depletion amount D at a stretch, and the limit of use was reached.

[0169]

According to the present invention, an image forming apparatus capable of preventing image deletion and sufficiently extending the drum life according to the use history (use time, number of image formation, etc.) of a photoreceptor having a hard coat layer. And an image forming method.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a copying machine that is an image forming apparatus.

FIG. 2 is a schematic configuration diagram of an image forming unit of the copying machine of FIG.

FIG. 3 is a front sectional view of a cleaning unit having a cleaning member of the copying machine of FIG. 1;

FIG. 4 is a sectional view showing a section taken along line IV-IV of FIG. 3;

FIG. 5 is a schematic view showing a part of a cleaning unit of the copying machine of FIG. 1;

FIG. 6 is a graph showing the relationship between the usage time of the photoconductor and the amount of wear when the contact load of the blade on the photoconductor is adjusted according to the present invention.

FIG. 7 is a graph showing the relationship between the usage time of the photoconductor and the amount of wear when the contact load of the blade to the photoconductor is maintained in a conventional non-adjusted state.

[Explanation of symbols]

2 Photoreceptor drum 5 Developing unit 6 Recycle pipe 11 Cleaning unit 13 Control means 18 Blade 25 Cam mechanism 26 Arm 27 Cam 31 Cam drive motor 40 Drum drive motor 101 Copier 105 Transfer paper D Depletion at the limit of use of photoreceptor K ₁ use limit time of the high contact load K ₂ low contact load t ₁ the photosensitive layer exposed starting t ₂ photoconductor

Claims (10)

[Claims] 1. A photoreceptor for forming an electrostatic latent image, a developing unit for developing the formed electrostatic latent image with toner in a developer, and a transfer for transferring the developed toner image to a transfer paper Means, and a cleaning member that scrapes and removes residual toner remaining on the photoconductor after the transfer, wherein the photoconductor is provided with a resin layer containing a siloxane-based resin having a crosslinked structure. An organic photoconductor, comprising: a load adjustment unit configured to adjust a contact load of the cleaning member to the photoconductor; and a control unit configured to control an operation of the load adjustment unit. An image forming apparatus, wherein the load adjusting unit is controlled so as to change the contact load according to a use history of a body. 2. The apparatus according to claim 1, wherein the control unit controls the load adjusting unit to change the contact load when all of the resin layer of the photoconductor has disappeared.
An image forming apparatus according to claim 1. 3. The image forming apparatus according to claim 1, wherein the control unit controls the load adjusting unit to change the contact load when a predetermined number of images is formed. . 4. The image forming apparatus according to claim 1, wherein said control means controls said load adjusting means so as to change said contact load when a predetermined photosensitive member usage time has been reached. apparatus. 5. The method according to claim 1, wherein the change of the contact load by the control means controls the load adjusting means so as to reduce the contact load. Image forming device. 6. An electrostatic latent image is formed on a photoconductor, a toner image is formed by developing the electrostatic latent image, the toner image is transferred to transfer paper, and a cleaning member is applied to the photoconductor. In the image forming method for removing the residual toner remaining on the photoconductor after the transfer in contact with the photoconductor, the photoconductor is an organic photoconductor provided with a resin layer containing a siloxane-based resin having a crosslinked structure, An image having a load adjusting step of adjusting a contact load of the cleaning member to the photosensitive member, wherein the load adjusting step changes the contact load according to a use history of the photosensitive member. Forming method. 7. The image forming method according to claim 6, wherein in the load adjusting step, the contact load is changed when all of the resin layer of the photoconductor has disappeared. 8. The image forming method according to claim 6, wherein the load adjusting step changes the contact load when a predetermined number of images is formed. 9. The image forming method according to claim 6, wherein in the load adjusting step, the contact load is changed when a predetermined photoconductor usage time has been reached. 10. The image forming method according to claim 6, wherein the load adjusting step reduces the contact load.