JP2001337581A - 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 of which the photoreceptor has good static charge characteristics, high sensitivity, and wear resistance and the surface electrical resistance does not lower at high humidity environment, therefore, in which a problem, such as image flowing, do not occur. SOLUTION: In the image forming device of a electrophotography mode, the photoreceptor is an organic photoreceptor provided with a resin layer containing siloxane-based resin having a cross-linked structure. The image forming device has a humidity control means to control relative humidity near the photoreceptor so as to be 50% or less.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic image forming apparatus such as a copying machine, a printer, and a facsimile, and an image forming method, and more particularly, to an image forming apparatus and an image forming apparatus characterized by controlling humidity near a photoreceptor. It relates to a 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.

[0003] Organic photoreceptors are widely used as photoreceptors from various viewpoints. However, compared to inorganic photoreceptors such as amorphous silicon and selenium photoreceptors, the mechanical strength is small.
There were problems in durability, such as the fact that image defects tend to occur due to scratches, and the charging ability and sensitivity were significantly reduced due to wear.

[0004] Various attempts have been made to solve the problem of durability of the organic photoreceptor and extend the life of the photoreceptor. For example, Japanese Unexamined Patent Publication No. 9-319130 reports a technique in which a surface layer contains a condensate of a curable organosilicon-based polymer and colloidal silica.

[0005]

Although the above-mentioned invention can be an effective means in some cases, this method does not always solve the problem sufficiently, and may cause another problem. I knew that I needed to find a solution.

According to the studies made by the present inventors, in an organosilicon-based crosslinked film, unreacted hydrolyzable groups and silanol groups are likely to remain on the film surface, and the influence of the adsorption of water molecules in a high-humidity environment is reduced. There are issues that are susceptible. If there are many unreacted groups, adsorption of water molecules and discharge products such as NOx (nitrogen oxide) and ozone generated at the time of electrification in a high humidity environment is likely to occur, and as a result, the surface resistance is reduced and the image flow ( Image blur)
Is a problem that occurs.

Accordingly, an object of the present invention is to provide a photosensitive member having good charging characteristics, high sensitivity and high abrasion resistance, and the surface resistance does not decrease even in a high humidity environment, so that problems such as image deletion do not occur. An object of the present invention is to provide an image forming apparatus and an image forming method.

[0008]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, a photoreceptor provided with a siloxane-based resin layer (hard coat layer) having a crosslinked structure (hard coat photoreceptor). It has been found that this problem can be solved by controlling the relative humidity in the vicinity to be 50% or less, and the present invention has been achieved.

That is, the object of the present invention has been achieved by the following constitutions. 1. An image comprising: a photoreceptor for forming an electrostatic latent image; developing means for developing the formed electrostatic latent image with toner in a developer; and transfer means for transferring the developed toner image to transfer paper In the forming apparatus, the photoreceptor is an organic photoreceptor provided with a resin layer containing a siloxane-based resin having a cross-linked structure, and has a relative humidity of 50 in the vicinity of the photoreceptor.
%. An image forming apparatus comprising: a humidity control unit for controlling the humidity to be equal to or less than 10%.

[0010] 2. The humidity control unit has a photoconductor temperature sensor for measuring the photoconductor temperature, a heater for heating the photoconductor, and an environment sensor for measuring the environmental humidity and the environment temperature where the image forming apparatus is placed. The heater is operated according to the environmental humidity and the environmental temperature measured by the environmental sensor to control the temperature of the photoconductor so that the relative humidity near the photoconductor becomes 50% or less. 2. The image forming apparatus according to 1 above.

3. In an image forming method of forming an electrostatic latent image on a photoconductor, developing the electrostatic latent image to form a toner image, and transferring the toner image to transfer paper, the photoconductor has a cross-linked structure An image forming method, comprising: an organic photoreceptor provided with a resin layer containing a siloxane-based resin, comprising a humidity control step of controlling a relative humidity near the photoreceptor to 50% or less.

4. The humidity control step includes: a photoconductor temperature measuring step of measuring the photoconductor temperature; a photoconductor heating step of heating the photoconductor; and an environment for measuring an environmental humidity and an environmental temperature in which the image forming apparatus is placed. Measuring step, wherein the photoconductor heating step is performed according to the environmental humidity and the environmental temperature measured by the environmental measuring step, and the relative humidity near the photoconductor is reduced to 50% or less. 4. The image forming method according to the above item 3, wherein the temperature is controlled.

[0013]

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

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. In this embodiment, the photoconductor drum 2 is an organic photoconductor (hard coat photoconductor) provided with a resin layer (hard coat layer) containing a siloxane-based resin having a crosslinked structure, which will be described in detail later. 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 thereafter, the transfer paper 105 is separated by the separating electrode 8 (separating means) and the separating claw 9. 2
From the fixing unit 11
To 8. 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;
However, the surface of the photosensitive drum 2 after the transfer is cleaned to remove foreign matters, residual toner, and the like. When the residual toner is removed,
Again, the charging electrode 3 charges the surface of the photosensitive drum 2 in preparation for the next image forming operation.

The recycling 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. Members having the same reference numerals as in FIG. 1 are the same as those described in 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), a photoconductor temperature sensor 4 are provided around a photoconductor drum 2 (photoconductor). , Developing unit 5 (developing means), transfer electrode 7
(Transfer means), separation electrode 8 (separation means), separation claw 9,
Cleaning unit 11 and pre-charging exposure unit (PC
L) 12 (pre-charging exposure means) are arranged in order. An environmental humidity sensor 21 and an environmental temperature sensor 22, which are environmental sensors, are provided inside the outer wall on the back side of the copying machine 101 (not shown in FIG. 1). Further, a heater 23 is provided inside the photoconductor drum 2 so that the temperature of the photoconductor can be increased. These are copier 101
Are connected to the control means 13 built in the.
The control means 13 operates the drum drive motor 40, the developing unit 5, the transfer electrode 7, the separation electrode 8, the cleaning unit 11 and the like based on the information input by the user from an instruction input unit (not shown) to copy. It controls the overall sequence of the image forming apparatus 101 and, as described later, photoconductor temperature information obtained from the photoconductor temperature sensor 4 and environmental information obtained from the environmental humidity sensors 21 and 22 (environmental humidity information and Based on the environmental temperature information), the O
By switching N / OFF and controlling the photoconductor temperature,
It has a function as humidity control means for controlling the relative humidity near the photoconductor to 50% or less.

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 sheet 05 is supplied, a positive direct current (+ DC) is applied to the transfer electrode 7 to apply a positive 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. You. Next, a negative direct current (-DC) and a positive alternating current (+ AC) are superimposedly supplied to the separation electrode 8 and the transfer paper 105 on which the toner image has been transferred is neutralized. The adsorbing force is reduced, and the separation is completed by being guided to the separation claw 9 while being naturally separated by its own weight, and then sent to the fixing unit 118.

On the other hand, the photosensitive drum 2 passing through the separation claw 9
The remaining toner is collected by the cleaning unit 11, and the pre-charging exposure unit 12 exposes the cleaned photosensitive drum 2 with uniform light to erase the residual potential. Make uniform and prepare for the next charging.

The recycle pipe 6 (see FIG. 1) is a pipe-shaped member having a screw for transporting the toner therein, and connects the cleaning unit 11 to the developing unit 5 from the surface of the photosensitive drum 2. The toner removed and collected by the cleaning unit 11 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 the rotation of the photosensitive drum 2 under the control of the control means 13,
Perform a stop.

Next, the humidity control means of the present invention will be described. The humidity control means of the present invention controls the relative humidity in the vicinity of the photoconductor so as to be 50% or less. “Near the photoconductor” refers to an atmosphere covering the surface of the photoconductor in a range that can affect the surface state of the photoconductor (such as the state of adhesion of water molecules and discharge products).

In the present embodiment, “controlling the relative humidity in the vicinity of the photoconductor to 50% or less” means the environmental humidity sensor 21 and the environmental temperature sensor 2 which are environmental sensors.
2, the environmental humidity and the environmental temperature where the copying machine 101 is placed are measured, and when the environmental humidity exceeds 50%, the photoconductor temperature (in this case, the ambient temperature in the vicinity of the photoconductor) is measured. It is determined whether the relative humidity in the vicinity of the photoconductor becomes 50% or less when the temperature is increased to about 50%. When the heater 23 is turned on, the photoconductor temperature obtained from the photoconductor temperature sensor 4 reaches a desired temperature. The control means 13 controls the heater 23 to be turned off. As a method of determining the temperature of the photoconductor at which the relative humidity near the photoconductor becomes 50% or less, the environmental humidity, the environmental temperature, and the desired humidity near the photoconductor (appropriately set at 50% or less) from the saturated water pressure curve.
A method is considered in which the relationship between the heater 23 and ON / OFF of the heater 23 is determined based on the relationship between the current temperature of the photoconductor and the current photoconductor temperature information obtained from the photoconductor temperature sensor. .

In the present embodiment, the environmental humidity sensor 21 and the environmental temperature sensor 22 are installed inside the exterior wall on the back side of the copying machine 101. By providing an air hole for taking in outside air on the exterior wall, it can be regarded as environmental information (environmental humidity information and environmental temperature information) in which the copying machine 101 is installed. Since the error increases from the environmental information, it is preferable to make a determination by appropriately adding a correction value. Alternatively, the environmental humidity sensor and the environmental temperature sensor may be provided outside the copying machine 101.

The heater 23 is not particularly limited as long as the temperature of the photosensitive drum 2 can be raised. The heater 23 has a nichrome wire wrapped around the inner wall of the photosensitive drum 2 or a ceramic heater is provided inside. You may. In order to raise the temperature of the entire photosensitive drum 2 uniformly, it is preferable that the nichrome wire is spread over the entire inner wall. The temperature of the photosensitive drum 2 is 50
If the temperature exceeds the temperature, the toner may be blocked in the developing unit 5 or the cleaning unit 11, or the physical properties of the cleaning blade in contact with the photosensitive drum 2 may be changed to deteriorate the cleaning characteristics. Therefore, it is preferable to control the temperature of the photosensitive drum 2 at 50 ° C. or less.

The photoreceptor temperature sensor 4 is for measuring the temperature of the surface of the photoreceptor drum 2.
Contact type to contact the non-image forming portion at the end of the
It may be a non-contact type.

In the present embodiment, as an example of controlling the relative humidity in the vicinity of the photoconductor to 50% or less, the control unit 13 serving as a humidity control unit controls the photoconductor temperature sensor 4.
, The heater 23, the environmental humidity sensor 21, and the environmental temperature sensor 22 were appropriately controlled, but the relative humidity of the atmosphere near the photoconductor was directly measured by the humidity sensor, and the dehumidifier provided in the apparatus was used. Alternatively, the control unit 13 may control the relative humidity near the photoconductor by controlling the heat exchanger or the heater of the photoconductor.

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 transporting 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).

[0038]

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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 An amino-containing group such as mercapto group, γ-aminopropyl, N-β (aminoethyl) -γ-aminopropyl, γ-chloropropyl, 1,1,1-trifluoropropyl, nonafluorohexyl, perfluorooctyl Examples include a halogen-containing group such as ethyl, 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 crosslinking agent is added, etc.). 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 contain colloidal silica having a hydroxyl group or a hydrolyzable group, and may be a resin having silica particles incorporated in a part of a 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 transporting ability 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-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 performance 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.

[0051]

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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 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 having a charge transporting ability and a hydroxyl group may be used.

X- (R ₇ -OH) _m wherein X: Structural unit having charge transport ability 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

[0061]

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[0062] 2. Hydrazine compounds

[0063]

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3. Stilbene compounds

[0065]

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4. Benzidine compound

[0067]

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5. Butadiene compound

[0069]

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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 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 where X: Structural unit having charge transport performance R ₈ : Single bond, substituted or unsubstituted alkylene group, arylene group m: Integer of 1 to 5 Among them, the following are typical ones.

[0072]

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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 group, substituted or unsubstituted arylene group R ₁₀ : A hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, m: an integer of from 1 to 5;

[0075]

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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.

[0078] 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 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 the above (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 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 charge-transporting structural unit and a cross-linked structure according to the present invention is prepared by adding a catalyst or a cross-linking 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 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). 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.

The charge transport material (CTM) contained in the charge transport layer 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 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 an appropriate 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, 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 charge transport layer may also serve 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, for the purpose of improving the surface characteristics of the electrophotographic photosensitive member, a thinner protective layer may be provided on the surface layer.

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,
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 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.

[0097]

EXAMPLES (Preparation of Organic Photoconductor-1) 60 g of a polyamide resin (Amilan CM-8000: manufactured by Toray Industries, Inc.) was added to 16
An intermediate layer composition solution was prepared by dissolving and dispersing in 00 ml of methanol, and was applied by dip coating onto a washed cylindrical aluminum substrate to form an intermediate layer having a thickness of 0.3 μm.

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) and 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.

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.

[0101]

Embedded image

(Embodiment of the Present Invention) The above-described organic photoreceptor-1 was mounted on the image forming apparatus shown in FIGS. 1 and 2, and each of the environmental conditions (1) to (1) detected by the environmental humidity sensor 21 and the environmental temperature sensor 22. 12) In (Table 1), the photoconductor temperature is controlled to the temperature shown in the column of the photoconductor control temperature in Table 2, and the relative humidity near the photoconductor is changed as shown in Table 2 to evaluate the image deletion. went. Table 2 also shows the evaluation results.

Regarding the image flow, under each environmental condition, the main switch of the image forming apparatus is turned off.
After standing for a period of time, 5000 images were formed, and the obtained images were visually evaluated for the presence or absence of image deletion.

：: Not generated X: Generated XX: Notably generated

[0105]

[Table 1]

[0106]

[Table 2]

(Comparison) In the above-mentioned embodiment of the present invention, Table 2
The image deletion was evaluated in the same manner without controlling the relative humidity by the above control. Table 3 shows the results.

[0108]

[Table 3]

As is clear from the above, according to the image forming apparatus having the organic photoreceptor and the humidity control means of the present invention, no image deletion occurs even in a high humidity environment, and stable image formation can be achieved. I understand.

[0110]

According to the present invention, there is provided an image forming apparatus and an image forming method in which a photosensitive member has good charging characteristics, high sensitivity and high abrasion resistance, and the surface resistance does not decrease even in a high humidity environment, so that problems such as image deletion do not occur. A method could be provided.

[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.

[Description of Signs] 2 Photoconductor drum 4 Photoconductor temperature sensor 5 Developing unit 6 Recycle pipe 7 Transfer electrode 8 Separation electrode 11 Cleaning unit 13 Control means 21 Environmental humidity sensor 22 Environmental temperature sensor 23 Heater 40 Drum drive motor 101 Copy Machine 105 transfer paper

Claims (4)

[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 Wherein the photosensitive member is an organic photosensitive member provided with a resin layer containing a siloxane-based resin having a crosslinked structure, and the relative humidity in the vicinity of the photosensitive member is 50% or less. An image forming apparatus comprising a humidity control unit for controlling. 2. The humidity control section measures a photoconductor temperature sensor for measuring the photoconductor temperature, a heater for heating the photoconductor, and an environmental humidity and environment temperature where the image forming apparatus is placed. An environmental sensor, wherein the heater is operated according to the environmental humidity and the environmental temperature measured by the environmental sensor to control the temperature of the photoconductor so that the relative humidity near the photoconductor becomes 50% or less. The image forming apparatus according to claim 1, wherein: 3. An image forming method for forming an electrostatic latent image on a photosensitive member, developing the electrostatic latent image to form a toner image, and transferring the toner image to transfer paper, wherein the photosensitive member is An organic photoreceptor provided with a resin layer containing a siloxane-based resin having a cross-linking structure, comprising: a humidity control step of controlling a relative humidity near the photoreceptor to 50% or less. Forming method. 4. The humidity control step includes: a photoconductor temperature measuring step of measuring the photoconductor temperature; a photoconductor heating step of heating the photoconductor; and an environmental humidity and environment in which the image forming apparatus is placed. An environment measuring step of measuring a temperature, wherein the photoconductor heating step is performed according to the environmental humidity and the environmental temperature measured in the environment measuring step, and the relative humidity near the photoconductor becomes 50% or less. 4. The image forming method according to claim 3, wherein the temperature of the photoconductor is controlled as described above.