Aluminum tube coating process for OPC photosensitive drum production and preparation

Abstract

The invention discloses an aluminum tube coating process for OPC photosensitive drum production and preparation, and belongs to the technical field of OPC photosensitive drum processing and preparation, and the aluminum tube coating process comprises the following steps: S1, preparing an outsourcing aluminum alloy into an aluminum tube; s2, the aluminum pipe is cleaned; s3, the cleaned aluminum pipe is sequentially subjected to the dip-coating process for three times; s4, nanoscale silicon dioxide particles accounting for 0.5%-2% of the total weight of the mixture are added in the preparation process of the substrate coating; s5, the photosensitive coating is prepared by dissolving polyamide resin in a tetrahydrofuran solution; s6, the charge transport layer is prepared by dissolving polycarbonate resin in tetrahydrofuran, and adding iron oxide and iron oxide yellow; and S7, the horizontal sand mill inputs the solid-liquid phase mixed material into the barrel through a material pump, and the disperser rotating at a high speed makes solid particles in the material collide, rub and shear with the grinding medium. According to the invention, stronger physical crosslinking points can be formed in the coating, and the adhesive force between the coating and the surface of the aluminum pipe is obviously improved.

Description

Technical Field

[0001] The invention belongs to the technical field of OPC photosensitive drum processing and preparation, in particular to an aluminum tube coating process for producing and preparing OPC photosensitive drums. Background Art

[0002] Organic photoconductor (OPC) drums are key components used in a wide range of office equipment, including laser printers, copiers, and multifunction printers. They convert electronic images into actual printed or copied output through a photoelectric conversion process. The core of an OPC drum typically consists of a precision-machined aluminum tube coated with a functional coating.

[0003] However, traditional production processes have many shortcomings in the processing and production links, resulting in unstable product quality, low production efficiency, and certain environmental pollution. For example, due to the lack of effective reinforcing materials, the traditional base coating has poor adhesion to the surface of the aluminum tube and is prone to peeling. Ordinary base coatings are easily affected by environmental factors such as temperature changes and humidity during use, which accelerates the aging of the coating and affects its service life. Summary of the Invention

[0004] The object of the present invention is to provide an aluminum tube coating process for producing and preparing an OPC photosensitive drum, so as to solve the problems raised in the background technology.

[0005] To achieve the above object, the present invention provides the following technical solution: a coating process for aluminum tubes used in the production of OPC photosensitive drums, comprising the following steps:

[0006] S1: The purchased aluminum alloy is made into aluminum tubes through extrusion, precision drawing and precision turning;

[0007] S2: Use ultrasonic cleaning machine to clean the aluminum tube;

[0008] S3: The cleaned aluminum tube is dip-coated three times in sequence, namely the base coating layer (UCL), the photosensitive coating layer (CGL) and the charge transport layer (CTL). After each dip-coating, it is dried at 90-130℃ for about 0.5 hours;

[0009] S4: Undercoat coating (UCL) is prepared by dissolving polyamide resin in methanol solution, mixing with titanium dioxide and pigment, grinding and dispersing in a horizontal sand mill for 5-10 hours, and filtering for use. During the preparation of the undercoat coating, 0.5%-2% of nano-sized silica particles by weight of the total mixture is added.

[0010] S5: Photosensitive coating (CGL) is prepared by dissolving polyamide resin in tetrahydrofuran solution and mixing with titanium oxide powder, grinding and dispersing in a horizontal sand mill for 1-3 hours, and then filtering for use;

[0011] S6: Charge transport layer (CTL) is prepared by dissolving polycarbonate resin in tetrahydrofuran, adding iron oxide and iron yellow, and placing the mixture in a sealed container and shaking it for use;

[0012] S7: The horizontal sand mill uses a material pump to input the solid-liquid phase mixture into the cylinder, and the high-speed rotating disperser causes the solid particles in the material and the grinding media to collide, rub and shear;

[0013] S8: The entire coating process is carried out in a closed chamber to prevent coating material leakage and contamination.

[0014] In this solution, the coating liquid in the coating process is recycled in the coating cylinder tank to avoid waste liquid discharge and reduce environmental pollution.

[0015] Preferably, in the present embodiment, nano-scale silica particles accounting for 0.5% to 2% by weight of the total mixture are added during the preparation of the base coating (UCL), and the mixture is uniformly dispersed at a speed of 1000 to 3000 rpm using a high-speed stirrer for at least 30 minutes to ensure that the nano-scale silica particles are fully suspended in the solution. Subsequently, the mixture is mixed with titanium dioxide and pigment in a mass ratio of 1:0.2:0.1, ground and dispersed in a horizontal sand mill for 5-10 hours, and then filtered for use.

[0016] In this solution, ultrasonic dispersion technology is used to replace the traditional mechanical stirring method during the preparation of the photosensitive coating (CGL), with a set frequency of 20-40kHz and a power density of 0.5-1.5W / cm 2 The treatment time is 1-3 hours, and the undispersed particles or impurities are removed by filtering with a pore size of 0.5-2 microns.

[0017] Preferably, in the present embodiment, a conductive polymer having a mass ratio of polycarbonate resin to conductive polymer of 1:0.1-0.3 is added during the preparation of the charge transport layer (CTL), the mixture is stirred for at least 30 minutes, and then iron oxide and iron yellow are added in a mass ratio of 1:0.05:0.02, and the mixture is placed in a sealed container and shaken for use.

[0018] This solution is preferred, and a double-layer dip coating process is used to prepare the base coating (UCL). The initial coating is dipped for 10-30 seconds, the drying temperature is 90-130 ° C, and the time is 20-40 minutes; the secondary reinforcement coating is also dipped for 10-30 seconds, and then dried under the same conditions. The thickness of each coating layer is controlled at 1-5 microns.

[0019] Preferably, a pH regulator is introduced into the ultrasonic cleaning process to adjust the pH value to within the range of 6.5-7.5, and the pH value of the subsequent water tank is monitored to ensure that the pH value is stable at 6.5-7.5 throughout the cleaning process.

[0020] Preferably, this solution is provided with a cooling step after each coating drying, the cooling rate is controlled at 5-15°C per minute, forced air cooling or water cooling is selected to cool the aluminum tube, the air flow velocity is controlled at 3-6m / s or the water flow velocity is controlled at 0.5-1.5m / s, and the water temperature is controlled at 10-20°C.

[0021] Preferably, in the process of manufacturing the charge transport layer (CTL), polycarbonate resin is dissolved in tetrahydrofuran and iron oxide and iron yellow are added to form a high-efficiency charge transport layer, thereby improving the charge transport efficiency of the OPC photosensitive drum.

[0022] The preferred solution of this invention is that the horizontal sand mill uses jacket circulating cooling water to maintain the temperature at 10-20°C to prevent safety hazards caused by high temperature.

[0023] Compared with the prior art, the technical effects and advantages of the present invention are:

[0024] This aluminum tube coating process for OPC photosensitive drum production involves adding 0.5% to 2% nano-silica particles by weight to a polyamide resin solution and evenly dispersing them using a high-speed agitator. The nano-silica particles, with their high specific surface area and excellent dispersibility, form stronger physical crosslinks within the coating, significantly improving adhesion between the coating and the aluminum tube surface. Furthermore, these particles fill minor surface defects, enhancing overall surface smoothness and uniformity, and thus increasing the coating's wear and corrosion resistance.

[0025] The coating is applied in a two-step process: a primary coating and a secondary reinforcement coating. The thickness of each layer is controlled between 1 and 5 microns. The primary coating provides a foundational support, while the secondary reinforcement coating increases the thickness and strength of the coating, forming a more stable coating structure. This precise control not only improves the consistency and performance of the coating, but also reduces the risk of coating peeling. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1This is a flow chart of an aluminum tube coating process for producing an OPC photosensitive drum according to the present invention;

[0028] Figure 2 A flow chart of the base coating of the present invention;

[0029] Figure 3 A flow chart of the photosensitive coating of the present invention;

[0030] Figure 4 Flowchart of the charge transport layer of the present invention. DETAILED DESCRIPTION

[0031] In the following description, numerous specific details are provided to provide a more thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be practiced without one or more of these details. In other instances, certain technical features well known in the art are not described to avoid confusion with the present invention.

[0032] Unless otherwise defined, the directions of up, down, left, right, front, back, inside and outside involved in this document are based on the directions of up, down, left, right, front, back, inside and outside shown in the figures of the present invention, and are explained here together.

[0033] This embodiment provides Figures 1 to 4 The illustrated process for coating an aluminum tube for producing an organic photoconductor (OPC) photosensitive drum includes the entire process from aluminum alloy processing to final product assembly.

[0034] In this embodiment, aluminum alloy processing: First, the purchased aluminum alloy is made into an aluminum tube through processes such as extrusion, precision drawing and precision turning. These steps ensure that the aluminum tube has high precision and good surface quality.

[0035] In this example, ultrasonic cleaning involves performing five cleaning steps on the aluminum tube using an ultrasonic cleaning machine. The first tank contains a mixture of surfactant and pure water, while the remaining four tanks contain ultrapure water. This gradual cleaning effectively removes dust and other contaminants from the aluminum tube's surface.

[0036] In this example, a base coating layer (UCL) is prepared as follows: a polyamide resin is dissolved in a methanol solution, and 0.5% to 2% by weight of nano-scale silica particles are added to the total mixture. The mixture is uniformly dispersed using a high-speed stirrer at 1000-3000 rpm for at least 30 minutes. The mixture is then mixed with titanium dioxide and pigment in a mass ratio of 1:0.2:0.1. The mixture is ground and dispersed in a horizontal sand mill for 5-10 hours, and then filtered for use. The addition of nano-scale silica particles not only improves the physical properties of the base coating, but also enhances its wear resistance and corrosion resistance. This enhancement exceeds the level achieved by traditional materials. The presence of nano-scale particles helps fill minor defects on the coating surface, thereby improving the overall surface smoothness and uniformity, which has a significant positive impact on the adhesion of subsequent coatings. Due to the high specific surface area and good dispersibility of the nano-scale silica particles, they can form stronger physical crosslinks in the coating, thereby improving the adhesion of the coating to the aluminum tube surface. Nanoscale particles can effectively disperse stress and reduce crack propagation within the coating, thereby enhancing the overall mechanical strength of the coating.

[0037] In this embodiment, a photosensitive coating (CGL) is prepared as follows: a polyamide resin is dissolved in a tetrahydrofuran solution and mixed with titanium oxide powder in a mass ratio of 1:0.3. Ultrasonic dispersion equipment is used with a frequency of 20-40 kHz and a power density of 0.5-1.5 W / cm2 set for a treatment time of 1-3 hours. After treatment, the mixture is filtered through a filter with a pore size of 0.5-2 microns to remove undispersed particles or impurities. Ultrasonic dispersion technology not only improves the uniformity of particle dispersion but also makes the titanium oxide powder finer, thereby significantly improving the photoelectric conversion efficiency of the photosensitive coating. The high-frequency vibration generated during the ultrasonic treatment helps remove small particles and impurities that have not been completely dissolved, further improving the quality of the coating. Ultrasonic dispersion technology ensures that the titanium oxide powder is evenly distributed in the solution, avoiding the problem of localized excessive concentration, thereby improving the optical uniformity of the coating. The removal of undispersed particles and impurities through high-frequency vibration can prevent these impurities from causing aging or failure of the coating during subsequent use.

[0038] In this embodiment, the charge transport layer is prepared by dissolving a polycarbonate resin in tetrahydrofuran, adding a conductive polymer in a mass ratio of 1:0.1-0.3 of polycarbonate resin to conductive polymer, stirring the mixture for at least 30 minutes, then adding iron oxide and iron yellow in a mass ratio of 1:0.05:0.02, placing the mixture in a sealed container and shaking it well for use. The addition of the conductive polymer not only optimizes the conductivity of the charge transport layer, but also improves the charge transport efficiency and response speed of the entire OPC photosensitive drum. The conductive polymer has good thermal stability and chemical stability, which helps to extend the service life of the charge transport layer and even the entire OPC photosensitive drum. The addition of the conductive polymer significantly reduces the resistivity of the charge transport layer, allowing electrons to be efficiently transmitted at a lower voltage, thereby improving the working efficiency of the overall device. The conductive polymer has good adaptability to changes in temperature and humidity and can maintain stable charge transport performance under a wide range of environmental conditions.

[0039] In this embodiment, three dip coating and drying are performed: the aluminum tube is dipped three times in sequence, forming the base coating layer (UCL), the photosensitive coating layer (CGL), and the charge transport layer (CTL). After each dip coating, the tube is dried at 90-130°C for about 0.5 hours. The specific steps are as follows:

[0040] Preliminary coating: dipping time 10-30 seconds, drying temperature 90-130℃, time 20-40 minutes.

[0041] Secondary reinforcement coating: The same dipping time of 10-30 seconds is followed by drying under the same conditions, with each layer controlled to a thickness of 1-5 microns. Traditional processes lack precise control over the temperature and time of coating drying, which can result in uneven coating, poor flow, or poor mixing. This solution, by drying at 90-130°C for approximately 0.5 hours after each dipping step, ensures that each layer dries quickly without flowing or mixing, ensuring consistent and stable coating and improving the quality and performance of the final product.

[0042] The dual-layer dip coating process allows for a secondary reinforcement layer on top of the primary coating, enabling more precise control of coating thickness. This fine control is crucial for ensuring coating consistency and performance. The primary coating provides a foundational support, while the secondary reinforcement layer increases the coating's thickness and strength, creating a more stable coating structure. The primary coating provides a better adhesion foundation for subsequent coatings, reducing the risk of coating peeling. The secondary reinforcement layer can be added with different functional ingredients, such as anti-scratch agents or antistatic agents, as needed to further enhance the coating's overall performance.

[0043] In this embodiment, the horizontal sand mill operates by using a pump to pump a solid-liquid mixture into a cylinder. A high-speed rotating disperser causes collision, friction, and shearing of the solid particles in the material with the grinding media. Cooling water circulating through the jacket maintains the temperature between 10-20°C to prevent safety hazards caused by high temperatures. Both the undercoat layer (UCL) and the photosensitive coating (CGL) are ground and dispersed using a horizontal sand mill. The high-speed rotating disperser causes collision, friction, and shearing of the solid particles in the material with the grinding media, accelerating particle refinement and dispersion. This results in a high-purity, uniformly distributed coating material, enhancing the coating's physical properties and photoelectric conversion efficiency.

[0044] In this embodiment, the cooling step is as follows: after each coating is dried, a cooling step is added: the cooling rate is controlled to drop by 5-15°C per minute, and forced air cooling or water cooling is selected to quickly cool the aluminum tube. For air cooling, a fan array is set to provide uniform airflow, and the airflow speed is controlled at 3-6m / s; for water cooling, the water flow speed needs to be controlled at 0.5-1.5m / s, and the water temperature is controlled at 10-20°C. The rapid cooling step not only shortens the production cycle, but also reduces the stress accumulation inside the coating by controlling the cooling rate, thereby reducing the risk of cracking or falling off of the coating. The uniform cooling process helps to maintain the thickness consistency and surface flatness of the coating, which is crucial to ensuring the quality of the coating. Rapid cooling by forced air cooling or water cooling can significantly shorten the waiting time after the coating is dried, improve production efficiency, and the appropriate cooling rate helps to eliminate the thermal stress inside the coating, thereby enhancing the long-term stability and reliability of the coating.

[0045] In this embodiment, a pH regulator is introduced into the ultrasonic cleaning process to adjust the pH value to within the range of 6.5-7.5, and the pH values of the subsequent four water tanks filled with ultrapure water are monitored to ensure that the pH value is stable between 6.5-7.5 during the entire cleaning process. Conventional cleaning and coating processes may not be able to completely remove tiny particles and pollutants on the surface of the aluminum tube, resulting in insufficient adhesion or defects in the coating. This solution uses an ultrasonic cleaning machine to perform five cleaning processes, and introduces a pH regulator into the first water tank to adjust the pH value of the cleaning solution to within the range of 6.5-7.5 to ensure the best cleaning effect. This multi-level cleaning method can effectively remove dust and other impurities on the surface of the aluminum tube, providing a clean foundation for the subsequent coating process, improving the adhesion and uniformity of the coating, and reducing product quality problems caused by surface contamination.

[0046] In this embodiment, the coating liquid is circulated in the coating cylinder tank during the entire coating process, avoiding waste liquid discharge and reducing environmental pollution. In addition, the horizontal sand mill uses jacket circulating cooling water to maintain the temperature at 10-20°C to prevent safety hazards caused by high temperature.

[0047] It should be noted that, in this article, relational terms such as one and two are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device that includes a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions. The sentence "including an element defined by ... does not exclude the presence of other identical elements in the process, method, article or device that includes the element."

[0048] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A coating process for aluminum tubes used in the production of OPC photosensitive drums, characterized in that: The following steps are involved: S1: The purchased aluminum alloy is made into aluminum tubes through extrusion, precision drawing and precision turning; S2: Use ultrasonic cleaning machine to clean the aluminum tube; S3: The cleaned aluminum tube is dip-coated three times in sequence, namely the base coating, the photosensitive coating and the charge transport layer. After each dip-coating, it is dried at 90-130°C for about 0.5 hours; S4: The base coating is prepared by dissolving a polyamide resin in a methanol solution, mixing it with titanium dioxide and pigment, grinding and dispersing it in a horizontal sand mill for 5-10 hours, and then filtering it for use. During the preparation of the base coating, 0.5%-2% of nano-sized silica particles by weight of the total mixture are added; S5: The photosensitive coating is prepared by dissolving a polyamide resin in a tetrahydrofuran solution and mixing it with titanium oxide powder. The mixture is ground and dispersed in a horizontal sand mill for 1-3 hours and then filtered for use. S6: The charge transport layer is prepared by dissolving polycarbonate resin in tetrahydrofuran, adding iron oxide and iron yellow, and placing the mixture in a sealed container and shaking it for use; S7: The horizontal sand mill uses a material pump to input the solid-liquid phase mixture into the cylinder, and the high-speed rotating disperser causes the solid particles in the material and the grinding media to collide, rub and shear; S8: The entire coating process is carried out in a closed chamber to prevent coating material leakage and contamination.

2. The aluminum tube coating process for producing an OPC photosensitive drum according to claim 1, characterized in that: The coating liquid in the coating process is circulated in the coating cylinder groove, thereby avoiding waste liquid discharge and reducing environmental pollution.

3. The aluminum tube coating process for producing an OPC photosensitive drum according to claim 1, characterized in that: During the preparation process of the base coating, nano-scale silica particles are added and the mixture is uniformly dispersed at a speed of 1000-3000 rpm using a high-speed stirrer for at least 30 minutes to ensure that the nano-scale silica particles are fully suspended in the solution. The mixture is then mixed with titanium dioxide and pigment in a mass ratio of 1:0.2:0.1, ground and dispersed in a horizontal sand mill for 5-10 hours, and then filtered for use.

4. The aluminum tube coating process for producing an OPC photosensitive drum according to claim 1, characterized in that: During the preparation of the photosensitive coating, ultrasonic dispersion stirring was used, with a set frequency of 20-40 kHz and a power density of 0.5-1.5 W / cm 2 The treatment time is 1-3 hours, and the undispersed particles or impurities are removed by filtering with a pore size of 0.5-2 microns.

5. The aluminum tube coating process for producing an OPC photosensitive drum according to claim 1, characterized in that: During the preparation of the charge transport layer, a conductive polymer is added at a mass ratio of polycarbonate resin to conductive polymer of 1:0.1-0.3, and the mixture is fully stirred for at least 30 minutes. Subsequently, iron oxide and iron yellow are added at a mass ratio of 1:0.05:0.02, and the mixture is placed in a sealed container and shaken for use.

6. The aluminum tube coating process for producing an OPC photosensitive drum according to claim 1, characterized in that: The base coating is prepared by a double-layer dip coating process. The initial coating is dipped for 10-30 seconds, dried at 90-130°C for 20-40 minutes; the secondary reinforcement coating is also dipped for 10-30 seconds and then dried under the same conditions. The thickness of each coating layer is controlled at 1-5 microns.

7. The aluminum tube coating process for producing an OPC photosensitive drum according to claim 1, characterized in that: A pH regulator is introduced into the ultrasonic cleaning process to adjust the pH value to within the range of 6.5-7.5, and the pH value of the subsequent water tank is monitored to ensure that the pH value is stable at 6.5-7.5 throughout the cleaning process.

8. The aluminum tube coating process for producing an OPC photosensitive drum according to claim 1, characterized in that: After each coating is dried, a cooling step is set up, and the cooling rate is controlled at 5-15°C per minute. Forced air cooling or water cooling is selected to cool the aluminum tube. The air flow speed is controlled at 3-6m / s or the water flow speed is controlled at 0.5-1.5m / s, and the water temperature is controlled at 10-20°C.

9. The aluminum tube coating process for producing an OPC photosensitive drum according to claim 1, characterized in that: During the preparation of the charge transport layer, polycarbonate resin is dissolved in tetrahydrofuran and iron oxide and iron yellow are added to form a high-efficiency charge transport layer.

10. The aluminum tube coating process for producing an OPC photosensitive drum according to claim 1, characterized in that: The horizontal sand mill uses jacket circulating cooling water to maintain the temperature at 10-20° C. to prevent safety hazards caused by high temperature.

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