A photosensitive drum containing a blocking layer and its application

Abstract

This application discloses a photosensitive drum comprising a barrier layer and its application, belonging to the field of photosensitive drum technology. The barrier layer of this application comprises titanium dioxide, waterborne polyurethane resin, and a waterborne polyurethane curing agent; the mass ratio of polyurethane in the titanium dioxide and waterborne polyurethane resin is 1:0.8-1.2; the mass of the waterborne polyurethane curing agent is 0.2-0.6% of the mass of the waterborne polyurethane resin. This application, by mixing titanium dioxide and waterborne polyurethane resin to prepare the barrier layer of the photosensitive drum, can improve the weather resistance of the photosensitive drum and maintain its performance in environments with temperatures ≤15℃ and relative humidity ≤RH15%.

Description

Technical Field

[0001] This application relates to organic photosensitive drums, and more specifically to a photosensitive drum comprising a barrier layer and its application. Background Technology

[0002] The core component of the toner cartridge—the photosensitive drum—is an aluminum tube with three coatings (blocking layer, generating layer, and conducting layer). The blocking layer is a semiconductor coating located between the organic photosensitive charge generating layer and the aluminum alloy substrate layer. Its main function is to maintain a certain resistance to ensure that the potential of the organic photosensitive drum surface does not drop rapidly in the dark area (i.e., reduce the dark decay rate).

[0003] The barrier layer is composed of titanium dioxide and nylon resin. The nylon resin commonly used is CM8000 manufactured by Toray Industries, Japan. Through thorough dispersion processes—stirring, ultrasonic dispersion, and ball milling—the nano-titanium dioxide can be uniformly dispersed in the nylon solution. On the other hand, the photosensitive drum coating is applied using an immersion coating method. In the above process, anhydrous ethanol is used as the main organic solvent for dispersion. The material is then fed into the production line coating machine for continuous production, with anhydrous ethanol needed as a diluent during the process. After immersion coating, the surface of the photosensitive drum requires baking.

[0004] The resistance of CM8000 increases in low-temperature and low-humidity environments, causing the photosensitive drum's blocking layer to affect the charge transfer speed in the exposure area. This results in light colors and negative ghosting during printing, especially at temperatures ≤15℃ and relative humidity ≤RH15%, where organic photosensitive drums using CM8000 as a binder for the blocking layer are unusable. The finished product exhibits poor weather resistance (withstanding environmental factors such as temperature and humidity), limiting its suitable working environment. Furthermore, the anhydrous ethanol and other organic solvents used in its production process evaporate into the air during baking, requiring further harmless treatment, increasing the complexity and cost of the process. Summary of the Invention

[0005] The purpose of this application is to overcome the shortcomings of the prior art and provide a photosensitive drum containing a barrier layer and its application; the barrier layer can improve the weather resistance of the photosensitive drum and maintain the performance of the photosensitive drum in an environment with a temperature ≤15℃ and relative humidity ≤RH15%.

[0006] To achieve the above objectives, the technical solution adopted in this application is as follows: a photosensitive drum comprising a barrier layer, wherein the barrier layer comprises titanium dioxide, waterborne polyurethane resin, and waterborne polyurethane curing agent; the mass ratio of polyurethane in the titanium dioxide and waterborne polyurethane resin is 1:0.8 to 1.2; and the mass of the waterborne polyurethane curing agent is 0.2-0.6% of the mass of the waterborne polyurethane resin.

[0007] In the barrier layer of this application, the waterborne polyurethane resin reacts with the polyisocyanate functional groups in the waterborne polyurethane curing agent to form a stable network structure. In the early stage of film formation after coating, physical drying is the main process. During this process, as the water evaporates, the particles in the liquid film begin to aggregate, and the polymer chain structure diffuses, gradually transitioning to chemical crosslinking. The crosslinking reaction involves the reaction between the NCO groups of the waterborne polyurethane curing agent and the hydroxyl groups, water, and carboxyl groups of the stable polymer particles, which can form an excellent stable structure. In addition, the hydroxyl groups of titanium dioxide and the carboxyl groups of polyurethane react to ensure that titanium dioxide is stably dispersed in the mixed solution, thereby improving the stability of the photosensitive drum at a temperature ≤15℃ and relative humidity ≤RH15%.

[0008] In this application, the mass ratio of titanium dioxide to polyurethane in the waterborne polyurethane resin can be 1:0.8, 1:0.85, 1:0.9, 1:0.95, 1:1, 1:1.05, 1:1.1, 1:1.15, or 1:1.2; or it can be a range consisting of any two of the above values. Preferably, the mass ratio of titanium dioxide to polyurethane in the waterborne polyurethane resin is 1:0.9-1.15.

[0009] The mass ratio of titanium dioxide to polyurethane in waterborne polyurethane resin is a key factor affecting the performance of the photosensitive drum. When the mass ratio of titanium dioxide to polyurethane in waterborne polyurethane resin is 1:0.8 to 1.2, the photosensitive drum also has excellent stability at temperatures ≤15℃ and relative humidity ≤RH15%.

[0010] In this application, the mass of the waterborne polyurethane curing agent can be 0.2%, 0.25%, 0.3%, 0.35%, 0.4%, 0.45%, 0.5%, 0.55%, or 0.6% of the mass of the waterborne polyurethane resin, or a range consisting of any two of the above values. Preferably, the mass of the waterborne polyurethane curing agent is 0.25-0.45% of the mass of the waterborne polyurethane resin. Using the waterborne polyurethane curing agent within the above range can further increase the stability of the barrier layer and improve the performance of the photosensitive drum.

[0011] Preferably, the thickness of the barrier layer is 1.5-4 μm.

[0012] The inventors discovered that the thickness of the barrier layer also affects the performance of the photosensitive drum, and the performance of the photosensitive drum is better within the above-mentioned thickness range.

[0013] Preferably, the barrier layer is prepared by: placing titanium dioxide and waterborne polyurethane resin in a ball mill for ball milling, adding waterborne polyurethane curing agent, mixing the resulting solution and coating it onto the substrate, and curing it to obtain the barrier layer.

[0014] Specifically, ball milling titanium dioxide and waterborne polyurethane resin can improve the dispersibility of titanium dioxide in the waterborne polyurethane resin, which is beneficial for the subsequent curing reaction. The mixture obtained from ball milling can be further milled to improve the dispersibility of titanium dioxide.

[0015] Preferably, the photosensitive drum further includes a generating layer and a protective layer.

[0016] Preferably, the generating layer comprises the following components in parts by weight: titanium phthalocyanine: polyvinyl butyral = 1: 0.2-0.6.

[0017] Preferably, the protective layer comprises the following components in parts by weight: N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine: polycarbonate = 1: 0.8-1.6.

[0018] Another objective of this application is to provide a method for preparing a photosensitive drum, comprising the following steps:

[0019] Preparation of the barrier layer: A barrier layer coating is applied to the substrate to form a barrier layer; the barrier layer comprises titanium dioxide, waterborne polyurethane resin and waterborne polyurethane curing agent; the mass ratio of polyurethane in the titanium dioxide and waterborne polyurethane resin is 1:0.8-1.2; the mass of the waterborne polyurethane curing agent is 0.2-0.6% of the mass of the waterborne polyurethane resin;

[0020] Preparation of the generating layer: A generating layer coating is applied to the barrier layer to form the generating layer; the generating layer coating comprises the following components: oxytitanium phthalocyanine and polyvinyl butyral, wherein the mass ratio of oxytitanium phthalocyanine to polyvinyl butyral is 1:0.2-0.6;

[0021] Preparation of protective layer: A protective coating is applied to the generating layer to form a protective layer, thus obtaining the photosensitive drum; the protective coating comprises N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine and polycarbonate; the mass ratio of N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine to polycarbonate is 1:0.8-1.6.

[0022] In this application, the mass ratio of titanium phthalocyanine to polyvinyl butyral can be 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45, 1:0.5, 1:0.55, or 1:0.6, or a range of any two of the above values. Preferably, the mass ratio of titanium phthalocyanine to polyvinyl butyral is 1:0.3-0.55.

[0023] In this application, the mass ratio of N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine to polycarbonate is 1:0.8, 1:0.85, 1:0.9, 1:0.95, 1:1, 1:1.05, 1:1.1, 1:1.15, 1:1.2, 1:1.25, 1:1.3, 1:1.35, 1:1.4, 1:1.45, 1:1.5, 1:1.55, or 1:1.6, and can be any range of two of the above values. Preferably, the mass ratio of N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine to polycarbonate is 1:0.95 to 1.5.

[0024] Another objective of this application is to provide the application of the photosensitive drum in electrophotographic printing.

[0025] Compared with the prior art, the beneficial effects of this application are as follows: by mixing titanium dioxide, waterborne polyurethane resin and waterborne polyurethane curing agent to prepare the blocking layer of the photosensitive drum, the weather resistance of the photosensitive drum can be improved, and the performance of the photosensitive drum can be maintained in an environment with temperature ≤15℃ and relative humidity ≤RH15%. Attached Figure Description

[0026] Figure 1 The actual printed images of the photosensitive drums obtained in Example 1 and Comparative Example 1 at a temperature of 26°C and a relative humidity of RH45% are shown.

[0027] Figure 2 The potential test diagram of the photosensitive drum of Example 1 at a temperature of 26°C and a relative humidity of 45% RH is shown.

[0028] Figure 3 The potential test diagram of the photosensitive drum of Comparative Example 1 at a temperature of 26℃ and a relative humidity of RH45% is shown.

[0029] Figure 4 The potential test diagram of the photosensitive drum of Example 1 at a temperature of 15°C and a relative humidity of RH15% is shown.

[0030] Figure 5 The PIDC test graph of the photosensitive drum of Example 1 at a temperature of 26°C and RH of 45% is shown.

[0031] Figure 6 The PIDC test results for the photosensitive drum of Comparative Example 1 are shown at a temperature of 26°C and a relative humidity of 45% RH.

[0032] Figure 7 The PIDC test diagram of the photosensitive drum of Example 1 at a temperature of 15°C and a relative humidity of RH15% is shown.

[0033] Figure 8The images shown are actual prints of the photosensitive drums obtained in Example 1 and Comparative Example 1 at a temperature of 15°C and a relative humidity of RH15%. Detailed Implementation

[0034] To better illustrate the purpose, technical solution, and advantages of this application, the following description, in conjunction with specific embodiments and comparative examples, aims to provide a detailed understanding of the content of this application, rather than limiting it. All other embodiments obtained by those skilled in the art without inventive effort are within the protection scope of this application. Unless otherwise specified, the experimental reagents and instruments involved in the implementation of this application are all commonly used reagents and instruments.

[0035] The raw materials used in the embodiments and comparative examples are described below, but are not limited to these materials:

[0036] Waterborne polyurethane resin: Manufacturer is Anhui Anda Huatai New Materials Co., Ltd., model number is AH-2209;

[0037] Waterborne polyurethane curing agent: Manufacturer is Anhui Anda Huatai New Materials Co., Ltd., model number is A01;

[0038] Other raw materials are commercially available products.

[0039] Example 1

[0040] This application discloses an embodiment of a photosensitive drum including a blocking layer, the photosensitive drum comprising a blocking layer, a generating layer, and a protective layer.

[0041] The barrier layer comprises the following raw materials: titanium dioxide, waterborne polyurethane resin, and waterborne polyurethane curing agent. The solid content of the waterborne polyurethane resin is 35%, wherein the mass ratio of polyurethane in the titanium dioxide and waterborne polyurethane resin is 1:1.15; and the mass of the waterborne polyurethane curing agent is 0.35% of the mass of the waterborne polyurethane resin.

[0042] The generating layer comprises the following raw materials: oxytitanium phthalocyanine and polyvinyl butyral, wherein the mass ratio of oxytitanium phthalocyanine to polyvinyl butyral is 1:0.55.

[0043] The protective layer comprises the following raw materials: N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine and polycarbonate; the mass ratio of N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine to polycarbonate is 1:1.35.

[0044] The method for preparing a photosensitive drum includes the following steps:

[0045] Barrier coating: Weigh titanium dioxide and waterborne polyurethane resin, place them in a ball mill at a ball-to-material ratio of 1:0.96, and ball mill at 45 r / min for 50 h. The resulting ball milling slurry and 13 kg of zirconium beads are placed in a sand mill and sand milled at 1300 r / min for 2 h. Nitrogen gas is used to pressurize the solution from the ball mill. Waterborne polyurethane curing agent is added to the resulting solution and stirred until homogeneous to obtain the barrier coating. The barrier coating is applied to an aluminum tube. After coating, the coated aluminum tube is placed in an oven and baked at 100℃ for 1 h to obtain a 3 μm thick barrier layer.

[0046] Generative layer coating: Oxytitanium phthalocyanine and polyvinyl butyral are mixed evenly to obtain a generative layer coating. The generative layer coating is applied to an aluminum tube. After coating, the aluminum tube containing the coating is placed in an oven and baked at 100°C for 1 hour. After testing the absorbance of the obtained film and finding it to be 0.2, the generative layer coating is applied to the barrier layer using a coating machine with the same coating parameters to obtain the generative layer.

[0047] Protective coating: N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine and polycarbonate are mixed evenly to obtain a protective coating. The protective coating is applied to the generating layer using a coating machine, and then baked at 120°C for 1 hour to obtain a 20 μm thick protective layer, which is the photosensitive drum E1.

[0048] Example 2

[0049] This application discloses an embodiment of a photosensitive drum containing a barrier layer. The only difference between this embodiment and Embodiment 1 is that the mass ratio of titanium dioxide in the barrier layer coating to polyurethane in the waterborne polyurethane resin is 1:0.8.

[0050] Example 3

[0051] This application discloses an embodiment of a photosensitive drum containing a barrier layer. The only difference between this embodiment and Embodiment 1 is that the mass ratio of titanium dioxide in the barrier layer coating to polyurethane in the waterborne polyurethane resin is 1:1.2.

[0052] Example 4

[0053] This application discloses an embodiment of a photosensitive drum including a blocking layer, the photosensitive drum comprising a blocking layer, a generating layer, and a protective layer.

[0054] The barrier layer comprises the following raw materials: titanium dioxide, waterborne polyurethane resin, and waterborne polyurethane curing agent. The solid content of the waterborne polyurethane resin is 35%, wherein the mass ratio of polyurethane in the titanium dioxide and waterborne polyurethane resin is 1:1.15, and the mass of the waterborne polyurethane curing agent is 0.2% of the mass of the waterborne polyurethane resin.

[0055] The generating layer comprises the following raw materials: oxytitanium phthalocyanine and polyvinyl butyral, wherein the mass ratio of oxytitanium phthalocyanine to polyvinyl butyral is 1:0.2.

[0056] The protective layer comprises the following raw materials: N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine and polycarbonate; the mass ratio of N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine to polycarbonate is 1:0.8.

[0057] The method for preparing the photosensitive drum in this embodiment includes the following steps:

[0058] Barrier coating: Titanium dioxide and waterborne polyurethane resin were weighed and placed in a ball mill at a ball-to-material ratio of 1:0.96 for ball milling at 45 r / min for 50 h. The resulting ball milling slurry and 13 kg of zirconium beads were placed in a sand mill for sand milling at 1300 r / min for 2 h. The solution was then extracted from the ball mill using nitrogen gas to obtain the barrier coating. The barrier coating was applied to an aluminum tube. After coating, the coated aluminum tube was placed in an oven and baked at 100 °C for 1 h to obtain a 1.5 μm thick barrier layer.

[0059] Generative layer coating: Oxytitanium phthalocyanine and polyvinyl butyral are mixed evenly to obtain the generative layer coating.

[0060] The generating layer coating is applied to the aluminum tube. After the coating is completed, the aluminum tube containing the coating is placed in an oven and baked at 100°C for 1 hour. After testing the absorbance of the obtained film and finding it to be 0.2, the generating layer coating is applied to the barrier layer using a coating machine with the same coating parameters to obtain the generating layer.

[0061] Protective coating: N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine and polycarbonate are mixed evenly to obtain a protective coating. The protective coating is applied to the generating layer using a coating machine, and then baked at 140°C for 1 hour to obtain a 30 μm thick protective layer, which is the photosensitive drum E1.

[0062] Example 5

[0063] This application discloses an embodiment of a photosensitive drum including a blocking layer, the photosensitive drum comprising a blocking layer, a generating layer, and a protective layer.

[0064] The barrier layer comprises the following raw materials: titanium dioxide, waterborne polyurethane resin and waterborne polyurethane curing agent, wherein the solid content of the waterborne polyurethane resin is 35%, the mass ratio of polyurethane in the titanium dioxide and waterborne polyurethane resin is 1:1.15, and the mass of the waterborne polyurethane curing agent is 0.6% of the mass of the waterborne polyurethane resin.

[0065] The generating layer comprises the following raw materials: titanium phthalocyanine and polyvinyl butyral, with a mass ratio of titanium phthalocyanine to polyvinyl butyral of 1:0.6.

[0066] The protective layer comprises the following raw materials: N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine and polycarbonate; the mass ratio of N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine to polycarbonate is 1:1.6.

[0067] The method for preparing the photosensitive drum in this embodiment includes the following steps:

[0068] Barrier coating: Titanium dioxide and waterborne polyurethane resin were weighed and placed in a ball mill at a ball-to-material ratio of 1:0.96 for ball milling at 45 r / min for 50 h. The resulting ball milling slurry and 13 kg of zirconium beads were then placed in a sand mill for sand milling at 1300 r / min for 2 h to obtain the barrier coating. The barrier coating was then applied to an aluminum tube. After coating, the coated aluminum tube was placed in an oven and baked at 100 °C for 1 h to obtain a 4 μm thick barrier layer.

[0069] Generative layer coating: Oxytitanium phthalocyanine and polyvinyl butyral are mixed evenly to obtain a generative layer coating. The generative layer coating is applied to an aluminum tube. After coating, the aluminum tube containing the coating is placed in an oven and baked at 100°C for 1 hour. After testing the absorbance of the obtained film and finding it to be 0.2, the generative layer coating is applied to the barrier layer using a coating machine with the same coating parameters to obtain the generative layer.

[0070] Protective coating: N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine and polycarbonate are mixed evenly to obtain a protective coating. The protective coating is applied to the generating layer using a coating machine, and then baked at 120°C for 1 hour to obtain a 15 μm thick protective layer, which is the photosensitive drum E1.

[0071] Comparative Example 1

[0072] This application provides a comparative example of a photosensitive drum containing a barrier layer. The only difference between this comparative example and Example 1 is that the barrier layer coating comprises titanium dioxide and CM8000, with a titanium dioxide to CM8000 ratio of 1:1.

[0073] Comparative Example 2

[0074] This application discloses a comparative example of a photosensitive drum containing a barrier layer. The only difference between this comparative example and Example 1 is that the mass ratio of titanium dioxide in the barrier layer coating to polyurethane in the waterborne polyurethane resin is 1:0.7.

[0075] Comparative Example 3

[0076] This application discloses a comparative example of a photosensitive drum containing a barrier layer. The only difference between this comparative example and Example 1 is that the mass ratio of titanium dioxide in the barrier layer coating to polyurethane in the waterborne polyurethane resin is 1:1.3.

[0077] Example 1

[0078] The performance of the photosensitive drums obtained in Examples 1-3 and Comparative Examples 1-3 of this application was tested.

[0079] (1) Printing test and blackness: The obtained photosensitive drum was actually printed under different conditions; the blackness of the obtained printing paper was tested with a blackness tester.

[0080] (2) Potential dark decay test: Using an OPC tester, a negative voltage of 700 volts is applied to the surface of the organic photosensitive drum in the form of corona charging; maintain this for 30 seconds without exposure to obtain the potential dark decay test pattern.

[0081] (3) PIDC test: Using an OPC tester, a negative voltage of 700 volts is applied to the surface of the organic photosensitive drum by corona charging. Under 780nm illumination, the exposure required to reduce the surface voltage of the organic photosensitive drum to 1 / 2, 1 / 5, and 100 volts of the original voltage is tested, and the PIDC test chart is obtained.

[0082] Figure 1 The left side of the image shows the printing effect of the photosensitive drum of Example 1, and the right side shows the printing effect of the photosensitive drum of Comparative Example 1. As can be seen from the images, the resolution and blackness of the photosensitive drums of Example 1 and Comparative Example 1 are similar. The blackness tester also confirmed that the blackness values ​​of the two are almost identical.

[0083] Figure 2 This is a potential test diagram of the photosensitive drum in Example 1 at a temperature of 26°C and a relative humidity of 45% RH. Figure 3 The image shows the potential test results of the photosensitive drum of Comparative Example 1 at a temperature of 26°C and a relative humidity of 45% RH. Figure 4 This is a potential test diagram of the photosensitive drum in Example 1 at a temperature of 15°C and a relative humidity of 15% RH. From... Figure 2-3It can be seen that at a temperature of 26℃ and a relative humidity of RH45%, the potential changes of the photosensitive drums in Example 1 and the comparative example are similar, indicating that the photosensitive drum of this application ensures that background gray (background gray: extremely fine and irregular black dots on the paper) will not appear on the printed paper during actual printing. From Figure 4 It can be seen that the decrease in drum surface voltage of the photosensitive drum obtained in Example 1 at a temperature of 15°C and a relative humidity of RH15% is the same as the decrease in drum surface voltage at a temperature of 26°C and a relative humidity of RH45%. This indicates that the photosensitive drum obtained in Example 1 can print at a temperature of 15°C and a relative humidity of RH15%, and the printing effect is comparable to that at room temperature.

[0084] Figure 5 The PIDC test diagram is shown for the photosensitive drum of Example 1 at a temperature of 26°C and RH of 45%. Figure 6 The image shows the PIDC test results of the photosensitive drum of Comparative Example 1 at a temperature of 26°C and a relative humidity of 45% RH. Figure 7 This is a PIDC test chart of the photosensitive drum of Example 1 at a temperature of 15°C and a relative humidity of 15% RH. From... Figure 5-7 As can be seen, in an environment with a temperature of 26℃ and a relative humidity of RH45%, the voltage of the photosensitive drums of Example 1 and Comparative Example 1 differs slightly under different exposure energies, which may lead to slight differences in blackness at different levels of actual printing. This is related to the performance of the materials and is within the standard. In an environment with a temperature of 15℃ and a relative humidity of RH15%, when the same exposure energy density is given, the voltage value of the photosensitive drum of Example 1 is higher than that at room temperature, which is reflected in a slightly lighter printing effect, which is at the lower limit of the standard and performs better than OPC with nylon resin as the matrix. Figure 8 The images show the printing results of the photosensitive drums obtained in Example 1 and Comparative Example 1 in an environment with a temperature of 15°C and a relative humidity of 15% RH. The photosensitive drum in Comparative Example 1 exhibits light color and negative ghosting after printing. Example 1 is closer to the printing effect at room temperature than Comparative Example 1. Figure 8 The left side shows the printing effect of the photosensitive drum of Example 1, and the right side shows the printing effect of the photosensitive drum of Comparative Example 1. Both were printed on test paper with a noticeable ghosting effect.

[0085] Finally, it should be noted that the above embodiments are used to illustrate the technical solutions of this application and not to limit the scope of protection of this application. Although this application has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of this application without departing from the substance and scope of the technical solutions of this application.

Claims

1. A photosensitive drum comprising a blocking layer, characterized in that, The barrier layer comprises titanium dioxide, waterborne polyurethane resin, and waterborne polyurethane curing agent; the mass ratio of polyurethane in the titanium dioxide and waterborne polyurethane resin is 1:0.8-1.2; the mass of the waterborne polyurethane curing agent is 0.2-0.6% of the mass of the waterborne polyurethane resin. The thickness of the barrier layer is 1.5-4 μm.

2. The photosensitive drum as described in claim 1, characterized in that, The barrier layer is prepared by: placing titanium dioxide and waterborne polyurethane resin in a ball mill and ball milling them, then adding a waterborne polyurethane curing agent and mixing.

3. The photosensitive drum as described in claim 1, characterized in that, The photosensitive drum also includes a generating layer and a protective layer.

4. The photosensitive drum as described in claim 3, characterized in that, The generating layer comprises the following components: oxytitanium phthalocyanine and polyvinyl butyral, wherein the mass ratio of oxytitanium phthalocyanine to polyvinyl butyral is 1:0.2 to 0.

6.

5. The photosensitive drum as described in claim 3, characterized in that, The protective layer comprises the following components: N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine and polycarbonate; the mass ratio of N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine to polycarbonate is 1:0.8 to 1.

6.

6. A method for preparing a photosensitive drum, characterized in that, Includes the following steps: Preparation of the barrier layer: A barrier layer coating is applied to the substrate to form a barrier layer; the barrier layer comprises titanium dioxide, waterborne polyurethane resin and waterborne polyurethane curing agent; the mass ratio of polyurethane in the titanium dioxide and waterborne polyurethane resin is 1:0.8-1.2; the mass of the waterborne polyurethane curing agent is 0.2-0.6% of the mass of the waterborne polyurethane resin; Preparation of the generating layer: A generating layer coating is applied to the barrier layer to form the generating layer; The generating layer coating comprises the following components: titanium phthalocyanine and polyvinyl butyral, wherein the mass ratio of titanium phthalocyanine to polyvinyl butyral is 1:0.2 to 0.

6. Preparation of protective layer: A protective coating is applied to the generating layer to form a protective layer, thus obtaining the photosensitive drum; the protective coating comprises N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine and polycarbonate; the mass ratio of N,N'-diphenyl-N,N'-di(3-methylphenyl)-1,1'-biphenyl-4,4'-diamine to polycarbonate is 1:0.8-1.

6.

7. The application of the photosensitive drum as described in any one of claims 1-5 in electrophotographic printing.

Images