JPH08160644A - Photoreceptor drum and manufacture thereof - Google Patents

Abstract

PURPOSE: To manufacture a photoreceptor drum capable of preventing the absorption of moisture in the air during the storage period from the anodizing process to the organic layer coating/baking process, preventing the progress of the natural sealing caused by the absorption of moisture, and preventing the reduction of the heat-proof temperature. CONSTITUTION: An anodized film is provided on the surface of an Al material, and a film made of an organic aluminum compound containing the hydrophobic group is provided on the surface layer of this film. The surface of the Al material is anodized to form the anodized film, the surface of the film is brought into contact with alcohol or a solution containing alcohol, the film made of the organic aluminum compound containing the hydrophobic group is formed on the surface layer of that film, then it is dried.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a photosensitive drum and a method for manufacturing the same, and more specifically, aluminum, that is, pure Al or Al alloy (hereinafter,
The present invention relates to a photoconductor drum having a functional film on a tube made of Al) and a method for manufacturing the photoconductor drum.

[0002]

2. Description of the Related Art As a photosensitive drum, an aluminum tube (support) having a surface on which amorphous selenium or amorphous silicon is vapor-deposited has been used. In recent years, an insulating layer has been formed on the surface of the Al tube (support). An organic photoconductor drum coated with an organic layer composed of a charge generation layer and a charge transfer layer is becoming the mainstream. Further, recently, the insulating layer in the organic layer of the organic photoconductor drum is replaced with an alumite treatment layer (that is, an anodized film) that has excellent insulation and has little dependency of temperature and humidity on printability. The number of photosensitive drums (hereinafter referred to as alumite photosensitive drums) is increasing.

In the above-mentioned alumite photosensitive drum, an anodizing treatment step of forming an alumite layer by subjecting an Al tube (conductive substrate) to anodizing treatment, and coating of a charge generation layer and a charge transfer layer (organic layer) It is manufactured through an organic layer coating and baking step of performing baking (baking of an organic coating film). At this time, the intermediate product processed in the anodizing process is stored in a storage warehouse or the like until the organic layer coating and baking process.

[0004]

By the way, the alumite film formed in the anodizing process generally has a
The coefficient of thermal expansion is smaller than that of the conductive substrate (Al tube), and the coefficient of elasticity is smaller than that of the organic coating film. Therefore, during drying after cleaning after anodizing treatment and during baking of the organic coating film, the alumite film causes the conductive substrate (Al
If the tube cannot withstand the expansion, so-called thermal cracking will occur.

The above-mentioned thermal crack is a leak point of electric charge when the photosensitive drum is used, that is, at the time of printing, and causes a printing defect. Therefore, it is important for commercializing the photosensitive drum not to generate the thermal crack. It is a condition. Therefore,
It is desired that the temperature at which thermal cracks occur in the alumite coating (hereinafter referred to as heat resistant temperature) be sufficiently higher than the baking temperature of the organic coating.

Therefore, the inventors of the present invention have conducted an investigation focusing on the relationship between the heat resistant temperature and the degree of sealing of the alumite coating, and as a result, the higher the sealing temperature at the time of sealing the alumite coating, the higher the sealing temperature. It was also found that the longer the sealing time, the higher the sealing degree, and eventually the lower the heat resistant temperature. That is, it was found that the heat resistant temperature can be increased by performing the sealing treatment while controlling the sealing degree to be small.

However, it is generally known that the alumite film absorbs moisture in the air to cause the sealing to proceed, which is a so-called natural sealing. Therefore,
By simply controlling the degree of sealing to be small during the sealing treatment, natural sealing progresses during the storage period until the organic layer coating and baking process, the heat resistant temperature decreases, and Since the heat resistant temperature is not maintained, there is a problem that the organic layer coating and baking cannot be performed at such a high heat resistant temperature.
Furthermore, there is a concern that thermal cracks may occur in the alumite film during baking of the organic coating film.

As a countermeasure against this, the present inventors controlled the temperature and humidity of the storage environment during the storage period from the sealing treatment to the organic layer coating and baking step in order to suppress the progress of natural sealing. Devised a method of doing (Japanese Patent Application No. 6-133833
issue). According to this method, the progress of natural sealing can be suppressed more than in the past, but the progress of natural sealing cannot be completely prevented (prevented), and further improvement is desired.

The present invention has been made in view of such circumstances, and its purpose is to solve the above-mentioned problems and to extend from the anodizing process to the organic layer coating and baking process. During a storage period, it is possible to prevent adsorption of moisture in the air, therefore prevent the progress of natural sealing due to absorption of moisture, and eventually to prevent a decrease in heat resistant temperature, and a method for producing the same. It is the one we are trying to provide.

[0010]

In order to achieve the above object, the photoconductor drum and the method for manufacturing the same according to the present invention are constructed as follows. That is, the photosensitive drum according to claim 1 has an anodized film on the surface of the aluminum material,
A photoconductor drum having a film made of an organoaluminum compound containing a hydrophobic group on a surface layer of the film. The contact angle of the surface of the film with respect to ion-exchanged water is 60 ° or more, 180
The photosensitive drum according to claim 1, wherein the photosensitive drum has an angle of less than °.

According to a third aspect of the present invention, there is provided a method for producing a photosensitive drum, wherein the surface of an aluminum material is anodized to form an anodized film, and the surface of the film is brought into contact with alcohol or a solution containing alcohol. A method for producing a photosensitive drum is characterized in that a film made of an organoaluminum compound containing a hydrophobic group is formed on the surface layer of the film, and then dried.

[0012]

[Function] When an Al material is anodized and an anodic oxide film is formed on the surface of the Al material, aluminum hydroxyl groups (Al-OH) are formed on the surface of the anodic oxide film (they are densely dispersed) . This Al-OH is very active, and when contacted with alcohol (R-OH), it is esterified as shown in the following formula to form an aluminum ester (Al-OR). It will be covered by (Al-OR). Here, such an ester (Al-OR) can be said to be one kind of so-called organic compounds that are metal-containing organic compounds, and since the metal is Al,
It can be called an organic aluminum compound. (Al-OH) ＋ (R-OH) → (Al-OR) ＋ H ₂ O

Since R of the above alcohol is alkyl, aryl or the like and is a hydrophobic group, R of the above ester or organoaluminum compound is a hydrophobic group. Therefore, this compound is an organoaluminum compound having a hydrophobic group. Is. Therefore, the surface of the anodic oxide film after the formation of the ester by contact with the alcohol is covered with the organoaluminum compound having the hydrophobic group R, and thus is in a state of being covered with the hydrophobic group R.

When the surface of the anodic oxide film is covered with the hydrophobic group R in this way, the water in the air cannot contact the anodic oxide film of the film, and the adsorption of water can be prevented. Therefore, it is possible to prevent the natural sealing from advancing due to the absorption of water, and to prevent the lowering of the heat resistant temperature.
In addition, the contact angle of water on the surface covered with the hydrophobic group R becomes large, which reduces the wetted area, which also makes it more difficult for the natural sealing to proceed due to absorption of water.

Based on the above, the photoconductor drum according to the present invention has an anodized film on the surface of an aluminum material and a film made of an organoaluminum compound containing a hydrophobic group on the surface layer of the film. It is said that. Therefore, according to this photoconductor drum, it is possible to prevent adsorption of moisture in the air during the storage period from the anodizing treatment step to the organic layer coating and baking step, and thus to prevent natural sealing due to absorption of moisture. It becomes possible to prevent the progress, and eventually to prevent the lowering of the heat resistant temperature.

In the method for producing a photosensitive drum according to the present invention, the surface of an aluminum material is anodized to form an anodic oxide film, and then the surface of the film is contacted with alcohol or a solution containing alcohol. A film made of an organoaluminum compound containing a hydrophobic group is formed on the surface layer of the film, and then dried. Therefore, according to this manufacturing method, the photosensitive drum according to the present invention having excellent characteristics as described above can be obtained.

Here, the more the hydrophobic group (R) is, the more the natural sealing can be prevented from proceeding, and from this point, the alcohol used preferably has a long carbon chain. Since the number of (Al-OH) is limited, R having a large number of CH bonds that exhibit hydrophobicity with respect to the alcohol group (OH) to be bonded is preferable. Therefore, R is most preferably an alkyl group having a long carbon chain, and is also preferable in that the longer the carbon chain, the larger the contact angle with water. As such alcohol,
For example, hexanol, dodecanol, etc. can be mentioned.

The purity of alcohol is preferably high. This is because esterification is an equilibrium reaction and the reaction tends to be suppressed by the presence of impurities. That is, the higher the purity of the alcohol and the less the impurities, the easier the esterification reaction for forming the film made of the organoaluminum compound containing the hydrophobic group tends to proceed.

When an alcohol or a solution containing alcohol (hereinafter referred to as a reaction solution) is brought into contact with the surface of the anodized film to form a film made of an organoaluminum compound containing a hydrophobic group, this is as described above. It is produced by esterification of (Al-OH) on the surface of the oxide film, but at the same time H ₂ O is produced in the reaction solution by the esterification, and the esterification reaction gradually becomes difficult to proceed. In order to prevent this, it is desirable to add sulfuric acid, p-CH ₃ C ₆ H ₄ SO ₃ H or the like as a catalyst to the reaction solution.

When the carbon chain of the alcohol becomes long, it becomes a solid alcohol at room temperature. In this case, it may be used after dissolving it in an organic solvent (benzene, carbon tetrachloride, lower alcohol, etc.).

The method of bringing the reaction solution (alcohol or alcohol-containing solution) into contact with the surface of the anodic oxide film is not limited and may be a method of immersing the reaction solution, a method of spraying the reaction solution, or a method of vaporizing the reaction solution. The method of leaving it in place can be applied.

[0022]

Example An Al alloy tube (conductive support) was manufactured by extruding an Al alloy into an extruded pipe, drawing it, and then mirror-finishing it by cutting. This Al alloy tube was subjected to anodizing treatment in a sulfuric acid aqueous solution having a sulfuric acid concentration of 10 wt% and a liquid temperature of 20 ± 1 ° C. to form an anodized film. At this time, the current density in the anodizing treatment was 70 amperes per square meter of the treated area of the product. Also, the film thickness was measured using an eddy current type film thickness meter (manufactured by Fischer) and was 10 ± 1 μm.
The processing time was adjusted so that

Immediately after the above anodic oxidation treatment, an immersion treatment in alcohol shown in Table 1 was carried out at 30 ° C. for 20 minutes, followed by drying to obtain a photosensitive drum according to an example of the present invention. At this time, for alcohol that was solid at 30 ° C., this was dissolved in ethanol and used in a saturated state. On the other hand, for comparison, the above anodized product was subjected to a 15-minute immersion treatment using a commercially available sealing agent to perform a sealing treatment to obtain a photosensitive drum according to a comparative example.

The photosensitive drum thus obtained is
Then, it was stored for 15 days, and thereafter, the sealing degree, the contact angle with water, and the heat resistant temperature (the temperature until the thermal cracking occurred in the anodized film) were measured. At this time, the degree of sealing was measured by an admittance measurement test specified in JIS H 8683. In this measuring method, the smaller the value, the greater the degree of sealing, indicating that the natural sealing is progressing. The contact angle is an angle Θ1 formed by the tangent line of the water droplet 1 and the film surface, as shown in FIG. Ion-exchanged water was used as water to improve the measurement accuracy of contact angle (improvement of reproducibility). Regarding heat resistant temperature, high temperature holding 30 minutes → room temperature holding (including air cooling time) 30 minutes → high temperature holding 30 minutes → room temperature holding (including air cooling time) 30 minutes → high temperature holding 30 minutes → room temperature holding (including air cooling time)
A heating / cooling cycle test was performed for 30 minutes, and the presence / absence of thermal cracks was visually and microscopically confirmed. Here, the temperature at which one or more thermal cracks were observed per square meter of the sample surface area was defined as the heat resistant temperature.

The results of the above measurements are shown in Table 1. The photoconductor drum according to the comparative example was obtained by performing a normal sealing treatment without an immersion treatment in alcohol after the anodizing treatment,
Admittance value is as small as 9μS, natural sealing is considerably advanced, contact angle is as small as 40 °, and heat resistance temperature is 100.
℃ is low.

On the other hand, the photoconductor drum according to the embodiment of the present invention has a large admittance value, a small degree of progress of natural sealing, a large contact angle of 60 to 130 °, and a high heat resistance temperature. . That is, when ethanol or 1-propanol was used as the alcohol for the alcohol immersion treatment, the contact angle was increased to 60 °, and at the same time, the heat resistant temperature was increased by 20 to 30 ° C as compared with the comparative example. When 1-hexanol, 1-octanol, 1-decanol, and 1-dodecanol are used, the contact angle is increased to 90 ° or more, and at the same time, the heat resistance temperature is increased by 40 ° C or more as compared with the comparative example, which is more preferable. It is in a state.

From the above, it can be seen that the heat resistant temperature can be made higher than that of the comparative example by setting the contact angle of the film surface with respect to ion-exchanged water to be 60 ° or more (less than 180 °) (claim 2 Photoconductor drum). Further, it is understood that the alcohol having a larger number of carbon atoms is preferable because the contact angle becomes larger and the heat resistant temperature is remarkably improved.

[0028]

[Table 1]

[0029]

The photosensitive drum according to the present invention can prevent the adsorption of moisture in the air during the storage period from the anodizing treatment step to the organic layer coating and baking step, and therefore, the absorption of moisture can be prevented. There is an effect that the natural sealing can be prevented from progressing, and eventually the lowering of the heat resistant temperature can be prevented. According to the method of manufacturing the photoconductor drum of the present invention, the photoconductor drum having excellent characteristics as described above can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram illustrating a contact angle of a film surface with water.

[Explanation of symbols]

 1-drop of water.

Claims (3)

[Claims] 1. A photoconductor drum having an anodized film on the surface of an aluminum material and a film made of an organic aluminum compound containing a hydrophobic group on the surface layer of the film. 2. The photosensitive drum according to claim 1, wherein the contact angle of the surface of the film with respect to ion-exchanged water is 60 ° or more and less than 180 °. 3. A surface of an aluminum material is anodized to form an anodized film, and then the surface of the film is brought into contact with alcohol or a solution containing alcohol to contain a hydrophobic group in the surface layer of the film. A method for producing a photosensitive drum, which comprises forming a film made of an organoaluminum compound and then drying.