JP2001255683A - Image forming device and method for separation of transfer paper in image forming device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an image forming device having high durability in which damages of an organic photoreceptor caused by a physical effect are prevented and the overall durability of the organic photoreceptor is improved, and to provide a method of separating a transfer sheet. SOLUTION: In the image forming device equipped with an organic photoreceptor 2, developing means 5 to form a toner image on the surface of the organic photoreceptor 2, transfer means 6 to transfer the toner image to a transfer paper P, and separation pawl 101 to separate the transfer sheet P from the organic photoreceptor 2, the surface layer of the organic photoreceptor 2 contains a siloxane resin having a crosslinked structure and the separation pawl 101 consists of a metal member.

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 such as a copying machine, a printer, a facsimile, etc., which forms a toner image on the surface of an organic photoreceptor by electrophotography and transfers the toner image onto transfer paper. More particularly, the present invention relates to an image forming apparatus for satisfactorily separating transfer paper from an organic photoreceptor surface, and a transfer paper separation method therefor.

[0002]

2. Description of the Related Art In the durability of an image forming apparatus, the durability of a photosensitive member has been dramatically improved due to the improvement of the performance of the photosensitive material. Performance degradation due to chemical action has been eliminated. For this reason, the durability of the image forming apparatus, particularly the durability of the photoconductor, has a problem that the photoconductor is damaged by a physical action.

That is, the above-mentioned physical effects received by the photoreceptor include abrasion of a photoreceptor surface layer due to abrasion of a blade for cleaning the surface of the photoreceptor, and forcible separation of transfer paper from the photoreceptor surface. The main factor is damage caused by contact of the separation member, particularly the separation claw.

On the other hand, an image forming apparatus using an electrophotographic system has shifted from an analog electrophotographic system to a digital electrophotographic system. In the analog electrophotographic method, an image is formed by irradiating a non-image portion, which does not form an image, with light on a charged photoreceptor, thereby developing a charged charge in a portion to be an image by a developing unit. In this case, a regular developing method is generally used as a developing means. On the other hand, in a digital electrophotographic image forming apparatus, a portion to be an image is irradiated and written on a charged photoconductor by a laser or an LED. Is a normal development, whereas a developing means for performing a reversal development in which a bias is applied to invert a latent image is used. Thereby, a portion written by the laser or the LED is formed as an image.

[0005] In the above-described reversal development system, the state of the charged charges on the photoreceptor on which an image is formed is mostly charged. That is, since a general document is a character document, the character portion of the document is slight, and most of the other portions are in a white background. For this reason, on the surface of the photoreceptor that is irradiated with a laser or the like for forming a latent image, there is only a decrease in the charged charge in a small part of the photoreceptor, and most of the area of the photoreceptor is non-image. This means that the charge remains as it is.

[0006] The image (toner image) on the photoreceptor thus formed is transferred to transfer paper by a transfer means. At the time of this transfer, the transfer paper strongly adheres to the photoreceptor by the action of electrostatic Coulomb force due to the charge on the photoreceptor. As described above, the effect of the Coulomb force is much larger in the reversal development than in the case of the regular development, so that it is much more difficult to separate the transfer paper from the photoreceptor after the transfer. come.

[0007] For such a difficult problem in separating the transfer paper, it is conceivable that a separation method such as a separation claw may be forcibly used. Even if it can be satisfied, a new problem arises in that the surface of the organic photoreceptor is scraped off by physical action on the organic photoreceptor having a resin surface, thereby impairing durability. In particular, since the surface of the organic photoreceptor is formed of a resin, if the separating claw comes into contact with the organic photoreceptor, the surface of the organic photoreceptor is damaged, and it is difficult to improve both the durability of the organic photoreceptor and the separation property of the transfer paper. Until now it has been difficult.

[0008]

In a conventional resin separating claw, when a transfer paper jam occurs at a contact position between the surface of the organic photoreceptor and the separating claw, the leading end of the separating claw is operated by a jam removing operation. May be deformed. Due to the deformation of the tip of the separation claw, the separation performance of the transfer paper is reduced.

Further, since the metal separating claw has high hardness, there is a possibility that the surface of the organic photoreceptor may be damaged by contact with the organic photoreceptor.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems relating to the physical action of an organic photoreceptor, and an object of the present invention is to achieve an improvement in the overall durability of an organic photoreceptor. An object of the present invention is to provide an image forming apparatus having high reliability.

Another object of the present invention is to provide a transfer paper separating method for an image forming apparatus.

[0012]

According to the present invention, there is provided an image forming apparatus comprising: an organic photoreceptor; developing means for forming a toner image on the surface of the organic photoreceptor; transfer means for transferring the toner image to transfer paper; In an image forming apparatus including a separation claw for separating transfer paper from the organic photoconductor, a surface layer of the organic photoconductor includes a siloxane-based resin having a cross-linking structure, and the separation claw is formed of a metal member. It is characterized by the following.

According to the transfer paper separating method of the image forming apparatus of the present invention, a separating claw made of a metal member is attached to an organic photoreceptor containing a siloxane-based resin having a cross-linked structure in a surface layer by a rake angle of -15 degrees to +15 degrees. It is characterized in that the transfer paper is separated by abutment at a time.

(Function) In the present invention, a specific resin is selected from resins constituting the surface layer of various organic photoreceptors,
In addition, by selecting a specific material and a contact condition from a variety of separation claws, the durability of the organic photoreceptor can be significantly improved, and an image forming apparatus that can achieve high durability can be provided.

Further, the present invention has found a transfer paper separating method for an image forming apparatus in which the durability of the organic photoreceptor can be significantly improved by bringing a separation claw into contact with the surface of the organic photoreceptor under specific conditions. .

Further, the present invention can provide an image forming apparatus which has good separability of the transfer paper from the organic photoreceptor and can guide the transfer paper after the separation well.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

FIG. 1 is a block diagram showing an example of an image forming apparatus according to the present invention, to which a digital electrophotographic system is applied.

In the image forming apparatus 1 shown in FIG. 1, a charging unit 3, a writing unit 4, a developing unit 5, a transferring unit 6, a discharging unit 7, a separating unit 10, and a cleaning unit are provided on the peripheral portion of the rotating organic photoreceptor 2. 8, the charging unit 3 uniformly charges the surface of the organic photoreceptor 2, and then forms a latent image by irradiating the laser of the writing unit 4 with light based on image data read from a document. The latent image is reversely developed by a developing unit 5 to which a bias is applied, and a toner image is formed on the surface of the organic photoconductor 2.

On the other hand, the transfer paper P fed from the transfer paper storage means 13 is sent to a transfer position, where the toner image is transferred onto the transfer paper P by the transfer means 6 at the transfer position.
Thereafter, the transfer paper P is erased from the back surface of the transfer paper P by the charge removing means 7, separated from the organic photoreceptor 2 by the separation means 10, conveyed by the intermediate conveyance unit 9, and subsequently heated and fixed by the fixing means 11, and discharged. 12 is discharged. On the other hand, the surface of the organic photoreceptor 2 has a cleaning blade 80 and a brush 8
The developer remaining on the surface is removed by 1 to prepare for the next image formation.

In the present invention, a specific organic photoreceptor whose surface layer contains a siloxane-based resin having a crosslinked structure (hereinafter, may be simply referred to as an organic photoreceptor 2) and a specific organic photoreceptor made of a metal member The application of the separation claw 101 (hereinafter, sometimes simply referred to as separation claw 101) has a synergistic effect of the present invention.

The separation claw 101 as the first component that exhibits the synergistic effect will be described.

FIG. 2 shows a separation claw 101 used in the present invention.
FIG. 4 is a cross-sectional view of a separating unit 10 provided with a slab.

In the separating means 10 shown in FIG.
1 is a separation claw made of a metal member, 102 is a separation claw 101
103 is a claw pressing spring for contacting the separation claw 101 with the organic photoreceptor 2, and 104 is a separation claw 10
A release plate 105 for releasing the abutment 1 is a separation claw 10.
A rotating shaft for rotating the holding member 102 to abut or release the photosensitive member 1 from the organic photoreceptor 2, a support frame 106 for supporting the members, and a release plate 104 for swinging 107. This is the rotation axis.

FIG. 3 is a bottom view of the separating means 10. The separation unit 10 includes a plurality of separation claws 101A, 101B, and 101C (hereinafter, collectively referred to as separation claws 101) arranged in parallel in the rotation axis direction of the organic photoconductor 2, and a plurality of holding members 102.
A, 102B, 102C (hereinafter collectively referred to as holding members 102), a plurality of claw pressing springs 103A, 103B, 103
C (hereinafter collectively referred to as claw pressing spring 103), release plate 10
4A, 104B and 104C (hereinafter collectively referred to as a release plate 104).

The holding member 102 is pivotally supported by the support frame 106 so as to be swingable. The distal end portion 101p of the separation claw 101 fixed to the holding member 102 is formed at an acute angle so as to reduce the contact area with the outer peripheral surface of the organic photoreceptor 2, and has a narrow width.

A release plate 104 is fixed to a rotating shaft 107 using the tip portion 101p of the separation claw 101 as an operating member for releasing the contact with the outer peripheral surface of the organic photoreceptor 2. The separation claw 101 is urged by a claw pressing spring 103 so that the distal end portion 101p comes into contact with the outer peripheral surface of the organic photoreceptor 2.

At one end of the rotating shaft 107, a release plate 1 is provided.
An electromagnetic solenoid 111 for operating the image forming unit 04 is provided in the image forming unit 110. Electromagnetic solenoid 111
Is normally off, and the tip 1 of the separation claw 101
01p is kept away from the outer peripheral surface of the organic photoreceptor 2. At the same time that the toner image is transferred to the leading end of the transfer paper P, the electromagnetic solenoid 111 is turned on and urged by the elastic force of the claw pressing spring 103 to move the leading end 101 p of the separation claw 101 to the organic photoconductor 2. The transfer paper P is separated by contacting the outer peripheral surface.

Driving means (not shown) provided in the image forming unit 110 rotates the cam 112 to
By pressing one end of the organic photoconductor 2, the support frame 106 is moved linearly in the direction of the rotation axis of the organic photoconductor 2. A return spring 113 presses the other end of the support frame 106.

The cam 112 rotates at an extremely low rotation speed such that one cycle of image formation of 100 sheets is formed.
1 in the direction of the rotation axis of the organic photoreceptor 2 so that the tip 1
The contact position on the outer peripheral surface of the organic photoconductor 2 of 01p is changed. By the operation of such an apparatus, the position where the tip 101p of the separation claw 101 contacts the outer peripheral surface (image forming surface) of the organic photoconductor 2 is dispersed over a wide area, so that the outer peripheral surface of the organic photoconductor 2 is dispersed. Prevents the occurrence of localized scars.

The separation claw 101 in the present invention is made of a metal member. Examples of the metal member include stainless steel, iron and steel, cemented carbide, sintered material, titanium alloy, phosphor bronze, and beryllium copper. Among these metal members, stainless steel is preferable in terms of wear resistance, corrosion resistance, spring properties, moldability, strength, and economy. Typical stainless steels include 18Cr-8Ni, 24Cr-13Ni, 25
Cr-20Ni-based, 20Cr-29Ni-based and the like.

The friction coefficient between the separation claw 101 and the organic photoreceptor 2 is reduced to reduce the wear of the separation claw 101 and the organic photoreceptor 2.
It is preferable to provide a coating of a fluororesin on the surface of the separation claw 101 in order to suppress damage due to contact with the surface. Polytetrafluoroethylene (PTFE) is suitable as the fluorine-based resin for forming the coating layer.
958-303 manufactured by DuPont (USA) and the like.
The thickness of the coating layer is preferably set to 5 to 11 μm.

Since fine projections (about 1 to 2 μm in height) may be generated on the surface of the coating layer, the surface of the coating layer is formed using a nonwoven fabric (for example, nylon mill cotton manufactured by Toray Industries, Inc.). Dry wiping (lapping) to remove the aforementioned minute projections and flatten the surface is preferable.

By providing the coating of the fluororesin, the coefficient of friction with the transfer paper P is reduced, and the guideability of the transfer paper P is improved.
It is also effective against contamination by toner particles and paper dust.

FIG. 4 shows a separation claw 101 and a holding member 102.
4A is a plan view, and FIG. 4B is a front view. FIG. 5 shows the shape of the separation claw 101, and FIG.
5A is a plan view, and FIG. 5B is a front view.

The holding member 102 has a mounting surface 102a for the separation claw 101 and a reference projection 10 for positioning the separation claw 101.
2b, side wall portion 102 for positioning the side end of separation claw 101
c, a hole 102d fitted to the rotating shaft 105, the release plate 10
4 in contact with the rear end portion 102e.

The tip 101p of the separation claw 101 has a flat tip when viewed from the upper and lower surfaces, and is in line contact with the organic photoreceptor 2. The tip 101p is
When viewed from the front, the tip forms a projection, and the organic photoreceptor 2
Is in a state almost close to point contact, and also makes line contact with the transfer paper P.

Reference hole 101 formed in separation claw 101
a is fitted into the reference projection 102b of the holding member 102 and positioned. A screw 108 penetrates the oval hole 101b formed in the separation claw 101, and fixes the separation claw 101 to the holding member 102.

FIG. 6 is a diagram for explaining the contact conditions when the separation claw 101 is brought into contact with the organic photoreceptor 2.

In FIG. 6, the separation claw 101 has an abutting portion (upper side view in FIG. 3) for abutting on the organic photoreceptor 2, and
The guide portion (the lower side in the side view in FIG. 3) is configured to guide the separated transfer paper P on the opposite side to the contact portion. a
Is the angle between the tangent of the organic photoconductor 2 at the contact point where the tip of the separation claw 101 is in contact with the organic photoconductor 2 and the contact portion of the separation claw 101. b indicates that the organic photoconductor 2 at the contact point where the tip of the separation claw 101 is in contact with the organic photoconductor 2
And the angle formed by the tangent of the separation claw and the guide portion of the separation claw 101.
c is a vertical line that is lowered from the center of the organic photoconductor 2 to the conveyance path of the transfer paper P with respect to the organic photoconductor 2 and a straight line that passes through the organic photoconductor 2 from the position where the tip of the separation claw 101 is in contact. The angle to make. d is a straight line passing through the center of the organic photoconductor 2 parallel to the transport path of the transfer paper P with respect to the organic photoconductor 2;
The angle between the contact point where the tip of the separation claw 101 is in contact with the organic photoconductor 2 and the tangent line of the organic photoconductor 2, which is below the straight line passing through the center of the organic photoconductor 2 parallel to the transport path. The angle formed is positive, and the angle formed above is negative. D can also be obtained from the expression "bc". In the present invention, a is also referred to as a contact angle, and d is also referred to as a rake angle.

The contact angle a of the separation claw 101 to the organic photoreceptor 2 of the present invention is preferably 5 to 25 degrees, because the separation of the transfer paper P can be further improved. If it is less than 5 degrees, the separation failure of the transfer paper P is likely to occur, and if it exceeds 25 degrees, the damage due to abrasion of the surface of the organic photoreceptor 2 tends to be promoted, and the durability of the organic photoreceptor 2 tends to decrease. Become.

When the rake angle d of the separation claw 101 to the organic photoreceptor 2 of the present invention is in the range of -15 degrees to +15 degrees, deformation of the separation claw 101 due to the end of the transfer paper P is prevented.
It is preferable from the viewpoint of improving the separability. When the angle exceeds +15 degrees, the force of the transfer paper P abutting against the separation claw 101 causes an increase in the force, so that the separation claw 101 is easily deformed. If the angle is less than −15 degrees, a conveyance failure of the separated transfer paper P is likely to occur.
As described above, by setting the rake angle d to -15 degrees to +15 degrees with the quadrangular pyramid-shaped separation claw 101 made of a metal member, the rake angle d can be preferably applied to the specific organic photoreceptor of the present invention. It has been found that the separation claw 101 has good separation properties and is effective in preventing deformation.

It is preferable that the separation claw 101 is brought into contact with the organic photosensitive member 2 by applying a load to the separation claw 101 by an elastic member. Due to a slight difference in the coefficient of friction of the surface of the organic photoconductor 2, the separation claw 101
When the transfer paper P comes by chance at this time, the transfer paper P may enter below the separation claw 101 and cause a separation failure. The above-mentioned bouncing phenomenon can be eliminated by the elastic member. As the elastic member, a metal spring is preferable.
03 corresponds. The contact of the separation claw 101 with the organic photoreceptor 2 is made only when the transfer paper P is sent.
When the transfer paper P does not need to be separated, the provision of a release member so that the contact of the separation claw 101 can be released can minimize damage to the organic photoreceptor 2 and significantly improve durability. Is preferred. In the present embodiment, the release plate 104 corresponds to the release member.

It is preferable that the separation claw 101 be swung with respect to the organic photoreceptor 2. By swinging the separation claw 101 on the organic photoconductor 2, the separation claw 101 is prevented from contacting only at the same position in the circumferential direction of the organic photoconductor 2, and the organic photoconductor is caused by friction between the organic photoconductor 2 and the separation claw 101. Local damage on the surface of the organic photoreceptor 2 can be eliminated, and the durability of the organic photoreceptor 2 can be further improved.

Next, a specific organic photoreceptor as a second component which exhibits the synergistic effect will be described.

The specific organic photoreceptor 2 used in the present invention is characterized in that the surface layer contains a siloxane-based resin having a crosslinked structure. Since the surface layer contains a siloxane-based resin having a crosslinked structure, hardening and reduction of the friction coefficient can be achieved, and damage to the surface of the organic photoreceptor 2 caused by contact of the separation claw 101 and the cleaning blade 80 is prevented. This significantly improves the durability of the organic photoreceptor 2.

The specific structure of the organic photoreceptor used in the present invention is such that an undercoat layer, a charge generation layer,
And a charge transport layer as a surface layer containing a siloxane-based resin having a crosslinked structure.
Further, the charge transport layer preferably has a two-layer structure of a lower layer containing a charge transport material and a binder resin and an upper layer containing a siloxane-based resin having a cross-linking structure with the charge transport material. In this case, the upper layer Becomes a surface layer. It is preferable that the siloxane-based resin having a crosslinked structure has a structural unit having charge transport performance.

The siloxane-based resin having a structural unit having charge transporting ability and having a crosslinked 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).

[0049]

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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 formula are hydrolyzable groups, the hydrolyzable groups are 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 hydrolysis-condensation product obtained by hydrolyzing the organosilicon compound under an acidic condition or a basic condition to oligomerize or polymerize can be used.

As described above, a 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.

In the present invention, the siloxane-based resin having a structural unit having a charge transporting property and having a crosslinked structure 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. 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-transport 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 organic silicon compound will be described below.

For example, hole transport type CTM: xazole, oxadiazole, thiazole, triazole, imidazole, imidazolone, imidazoline, bisimidazolidin, 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 charge transporting compound which is usually used as described above, and the following unit is bonded 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.

[0062]

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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, that is, the atoms of O, S, and N are hydroxyl groups introduced into the compound having the charge transporting performance, respectively.
A linking group formed by the reaction of a mercapto group or an amine group with an organic silicon compound having a hydroxyl group or a hydrolyzable group, and incorporating a structural unit having a charge transporting property into a 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 as follows:
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 may be used as long as it has charge transport performance and has a hydroxyl group.

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

[0072]

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2. Hydrazine compounds

[0074]

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3. Stilbene compounds

[0076]

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4. Benzidine compound

[0078]

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5. Butadiene compound

[0080]

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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 that can form a resin layer include, but are not limited to, the following structure, having charge transporting performance, and having a mercapto group. Any compound may be used.

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

[0083]

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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 performance 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.

[0086]

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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.

[0089] 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 material for forming the siloxane-based resin: The composition ratio of the above-mentioned general formulas (A) to (D) (hereinafter referred to as (A) to (D)) is as follows: organosilicon compound: 1 mole of component (A) + (B) , (C) + (D) component 0.05 to 1 mol is preferably used.

When 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 amount of the reactive charge transporting compound (F) capable of forming a resin layer by reacting with the organosilicon compound or colloidal silica is the same as that of (A) +
It is preferable to use 1 to 500 parts by mass of (F) based on 100 parts by mass of the components (B) + (C) + (D). When the component (A) + (B) is used beyond the above range, when the component (A) + (B) is small, the siloxane resin layer has a too low 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 transport performance of the siloxane resin layer is low, and the sensitivity and the residual charge increase. 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 obtained by adding a catalyst or a crosslinker 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.

Generally, a three-dimensional network structure can be formed by a condensation reaction of a composition having an alkoxysilane or a composition having an 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.

The layer constitution of the organic photoreceptor of the present invention is not particularly limited, but may be a charge generation layer, a charge transport layer, or a charge generation layer.
It is preferable to adopt a configuration in which a photosensitive layer such as a charge transport layer (single-layer type photosensitive layer having both functions of charge generation and charge transport) and a surface 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 charge generation layer of the present invention include phthalocyanine pigments
Polycyclic quinone pigments, azo pigments, perylene pigments, indigo pigments, quinacridone pigments, azurenium pigments, squalilium dyes, cyanine dyes, pyrylium dyes, thiopyrylium dyes, xanthene dyes, triphenylmethane dyes,
Styryl dyes and the like, and these charge generating substances (C
GM) forms a layer alone or together with a suitable binder resin.

Examples of the charge transport material (CTM) contained in the charge transport layer include oxazole derivatives, oxadiazole derivatives, thiazole derivatives, thiadiazole derivatives, triazole derivatives, imidazole derivatives,
Imidazolone derivatives, imidazoline derivatives, bisimidazolidine derivatives, styryl compounds, hydrazone compounds,
Benzidine compound, pyrazoline derivative, stilbene compound, amine derivative, oxazolone derivative, benzothiazole derivative, benzimidazole derivative, quinazoline derivative, benzofuran derivative, acridine derivative, phenazine derivative, aminostilbene derivative, poly-N-vinylcarbazole, poly-1- Vinylpyrene, poly-9-
Vinyl anthracene and the like can be mentioned, and these charge transporting substances (CTM) are usually formed into a layer together with a binder.

The charge generation layer (CGL) and the charge transport layer (CT
As the binder resin contained in L), polycarbonate resin, polyester resin, polystyrene resin, 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,
Examples include a silicone resin, an epoxy resin, a silicone-alkyd resin, a phenol resin, a polysilane resin, and polyvinyl carbazole.

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 weight.
0: 1 is preferred. Further, the thickness of the charge generation layer is preferably 5 μm or less, particularly preferably 0.05 to 2 μm.

The charge transport layer is formed by dissolving the charge transport material and the binder resin in a suitable solvent, and applying and drying the solution. The mixing ratio of the charge transport material and the binder resin is 10: 1 to 1:10 by mass.
Is preferred.

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.

When the surface layer containing the siloxane-based resin of the organic photoreceptor used in the present invention is a charge transport layer, the surface layer may serve also as the charge transport layer. Preferably, the charge transport layer or the charge generation layer is used. It is preferable to provide it as a separate surface layer. In this case, an adhesive layer may be provided between the photosensitive layer and the surface layer of the present invention. Further, a thinner protective layer may be provided on the surface layer for the purpose of improving the surface characteristics of the organic photoreceptor for electrophotography.

Next, the conductive support of the organic 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
Conductive polymers, indium oxide, those provided with a layer of a conductive compound such as tin oxide by coating or vapor deposition, and the like. As a material of the conductive support used in the present invention, mainly aluminum, copper, brass, steel A belt-shaped or drum-shaped metal material such as stainless steel or other 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.

Further, the conductive support may have a surface on which a sealed alumite film is formed.

Next, as a coating method for producing the organic photoreceptor used in the present invention, a coating method such as dip coating, spray coating, circular amount control type coating is used. The coating process on the side uses a coating process such as spray coating or circular volume control type (a typical example is a circular slide hopper type) to minimize the dissolution of the lower layer film and to achieve uniform coating. preferable.
The spray coating is described in, for example, JP-A-3-90.
No. 250 and JP-A-3-269238, and the circular amount-control type coating is described in detail, for example, in JP-A-58-189061.

The organic photoreceptor used in the present invention, after the resin layer is coated and formed, has a temperature of 50 ° C. or higher, preferably 60 ° C.
It is preferable to heat and dry at a temperature of 200C. By this heating and drying, the remaining coating solvent can be reduced, and the curable resin layer can be sufficiently cured.

(Example) (Preparation of Organic Photoconductor 2) Polyamide resin (Amilan CM)
-8000: manufactured by Toray Industries, Inc.) Dissolve and disperse 60 g in 1600 ml of methanol to prepare an intermediate layer composition solution, apply it to a washed cylindrical aluminum substrate by dip coating, and apply a 0.3 μm thick intermediate 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 containing 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 charge transport material and 300 g of bisphenol Z-type polycarbonate (Iupilon Z30)
0: manufactured by Mitsubishi Gas Chemical Co., Ltd.) 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.

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. The composition was cured by heating to produce the organic photoreceptor 2 of the present invention.

[0112]

Embedded image

(Image Forming Test) The organic photoreceptor 2 and the separation claw 101 shown in FIG. 5 were mounted on the image forming apparatus shown in FIG. 1, and an image forming test of one million sheets was performed.

The separating claw 101 at this time is made of a metal member, has the shape shown in FIG. 5, and has a tip portion coated with a fluororesin. The contact condition of the separation claw 101 is as follows:
The contact angle a was 9 degrees, the rake angle d was -3 degrees, and c was 40 degrees. The image forming apparatus is of a digital electrophotographic type, and the developing means is of a reversal developing type. Separation claw 10
1 is oscillated, a spring load of 300 mgf is applied, and the contact is released except when the transfer paper P is separated.

As a result of the image forming test for one million sheets, no damage to the organic photoreceptor 2 was observed, and no deformation of the separation claw 101 occurred. The resulting image forming apparatus had a durability of one million sheets.

[0116]

As described above, according to the present invention, the organic photoreceptor, developing means for forming a toner image on the surface of the organic photoreceptor, transfer means for transferring the toner image to transfer paper, and transfer paper In an image forming apparatus provided with a separation claw for separating from the organic photoreceptor, the surface layer of the organic photoreceptor contains a siloxane-based resin having a crosslinked structure, and the separation claw is formed of a metal member. The image forming apparatus has good separation performance and transportability of the transfer paper, does not cause separation failure due to deformation of the separation claw, prevents damage to the organic photoreceptor, significantly improves durability, and thus has high durability An image forming apparatus capable of realizing image formation can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an example of an image forming apparatus of the present invention.

FIG. 2 is a sectional view of a separating unit provided with a separating claw used in the present invention.

FIG. 3 is a bottom view of the separating means.

FIG. 4 is a plan view and a front view showing shapes of a separation claw and a holding member.

5A and 5B are a plan view and a front view showing the shape of the separation claw.

FIG. 6 is a diagram illustrating contact conditions when the separation claw is brought into contact with an organic photoreceptor.

DESCRIPTION OF SYMBOLS 1 Image forming apparatus 2 Organic photoreceptor 6 Transfer means 7 Static elimination means 8 Cleaning means 10 Separation means 101, 101A, 101B, 101C Separation claw 101p Tip 102, 102A, 102B, 102C Holding member 103, 103A, 103B, 103C Claw pressing springs 104, 104A, 104B, 104C Release plate 105 Rotating shaft 106 Support frame 107 Rotating shaft 108 Screw 110 Image forming unit P Transfer paper

 ──────────────────────────────────────────────────続 き Continued on the front page F-term (reference) 2H032 DA12 DA21 2H068 AA03 BB32 BB57 FC11 FC20 2H077 AD35 GA17

Claims (11)

[Claims] An organic photoreceptor, developing means for forming a toner image on the surface of the organic photoreceptor, transfer means for transferring the toner image to transfer paper, and a separation claw for separating the transfer paper from the organic photoreceptor The surface layer of the organic photoreceptor contains a siloxane-based resin having a crosslinked structure, and the separation claw is made of a metal member. 2. The image forming apparatus according to claim 1, wherein a tip portion of the separation claw that contacts the surface of the organic photoconductor is coated with a fluorine resin. 3. The image forming apparatus according to claim 1, wherein the separation claw is supported so as to be able to contact and separate from an outer peripheral surface of the organic photoreceptor. 4. The image forming apparatus according to claim 1, wherein the separation claw is supported so as to reciprocate in a generatrix direction of an outer peripheral surface of the organic photoconductor. 5. The image forming apparatus according to claim 1, wherein the developing unit is a developing unit that performs reversal development. 6. The image forming apparatus according to claim 1, wherein the image forming apparatus is a digital electrophotographic image forming apparatus. 7. The image forming apparatus according to claim 1, wherein a contact angle of the separation claw contacting the organic photoreceptor is 5 to 25 degrees. 8. The image forming apparatus according to claim 1, wherein the contact of the separation claw is performed by applying a load to the separation claw by an elastic member. 9. A transfer sheet is separated by bringing a separation claw made of a metal member into contact with an organic photoreceptor containing a siloxane-based resin having a crosslinked structure in a surface layer at a rake angle of -15 to +15 degrees. A transfer paper separating method for an image forming apparatus. 10. The method according to claim 9, wherein the image forming apparatus is a digital electrophotographic image forming apparatus. 11. The transfer sheet separating method according to claim 9, wherein a developing unit is provided in the image forming apparatus, and the developing unit is a developing unit that performs reversal development.