Positive charging type high-wear-resistance organic photoconductor drum and preparation method thereof

Abstract

The invention belongs to the technical field of organic photoconductor drums, and particularly relates to a positive charging type high-wear-resistance organic photoconductor drum and a preparation method thereof. The preparation method comprises the following steps: (1) adding polycarbonate, an electron transport material, a charge generation material and a dispersing agent into a first solvent, and obtaining a coating liquid A after the materials are completely dissolved and uniformly mixed; (2) adding a metal compound and polycarbonate into a second solvent to obtain a metal compound dispersion liquid; and (3) uniformly mixing the metal compound dispersion liquid with the coating liquid A to obtain a coating liquid B, coating the aluminum base with the coating liquid B, and drying to obtain the aluminum-based coating. Compared with a common positive charging type organic photoconductor drum, the positive charging type high-wear-resistance organic photoconductor drum has the advantages that the printing service life is obviously prolonged, image layers are uniform, the color density is excellent, and the positive charging type high-wear-resistance organic photoconductor drum has a wide market prospect.

Description

Technical Field

[0001] The invention belongs to the technical field of organic photoconductor drums, and in particular relates to a positively charged highly wear-resistant organic photoconductor drum and a preparation method thereof. Background Art

[0002] Organic photoconductive drum (OPC) is the most important core component of office automation equipment (laser printers, electrostatic copiers, etc.) and new digital printing equipment. It is also a high-tech product that uses the photoelectric conversion effect to achieve electrostatic imaging. Early photoconductive materials were inorganic substances such as selenium and cadmium sulfide. Compared with the toner cartridges produced with inorganic photosensitive materials in the past, organic photoconductive drums have high production capacity, low production costs, and adaptability to common light waves and laser light sources with a wavelength of 600 to 900nm. They have quickly replaced the original inorganic photoconductive drums and have a very large sales market and demand.

[0003] Currently, most commercialized organic photoconductor drums are of the function-separated type and the single-layer structure type. The function-separated type is mostly divided into two-layer structures, namely the charge generation layer (CGL) and the charge transport layer (CTL). Different functional layers need to be coated on the aluminum substrate separately, first the charge generation layer is coated, and then the charge transport layer is coated.

[0004] The single-layer OPC has only one layer of structure, and the charge generation material (CGM), hole transport material (HTM), electron transport material (ETM) and the like need to be gradually dispersed or dissolved in a solvent in a certain order, and then ball-milled and stirred to form a uniform multi-component system, and then coated on an aluminum substrate with a suitable surface roughness at a certain coating speed to form a photoconductive film with a suitable thickness. At present, due to the improvement of the printing quality of manuscripts by customer groups, the corresponding requirements and standards for organic photoconductive drums have also been improved accordingly. The pursuit of longer service life and clearer and more defined printing levels has become the current trend. Therefore, the development of a long-life and highly wear-resistant organic photoconductive drum has broad demand under the current market prospects, and has high value and important significance. Summary of the invention

[0005] In view of the shortcomings of the prior art, the present invention provides a positively charged highly wear-resistant organic photoconductive drum and a preparation method thereof. The service life of the drum core is significantly prolonged, the image layers are uniform, and the color density is excellent. It has broad demand and advantages under the current market prospects.

[0006] Specifically, the present invention provides the following technical solutions:

[0007] A method for preparing a positively charged highly wear-resistant organic photoconductive drum comprises the following steps:

[0008] (1) adding polycarbonate, electron transport material, charge generating material and dispersant into a first solvent, and after all the materials are dissolved and mixed uniformly, a coating solution A is obtained;

[0009] (2) adding a metal compound and a polycarbonate into a second solvent to obtain a metal compound dispersion;

[0010] (3) The metal compound dispersion and the coating liquid A are mixed evenly to obtain a coating liquid B, and the coating liquid B is coated on an aluminum substrate. After drying, a positively charged, highly wear-resistant organic photoconductive drum is obtained.

[0011] Preferably, in step (1), the dispersant is selected from at least one of paraffin, polyethylene glycol and silicone oil; more preferably silicone oil. Studies have shown that silicone oil is particularly suitable for the present invention, and is more conducive to the dispersion of materials, reduces local aggregation, and ensures the uniformity of the coating of the product during the production process.

[0012] Preferably, in step (1), the first solvent comprises tetrahydrofuran, cyclohexanone and chlorobenzene in a mass ratio of 100:(50-70):(30-50). Studies have found that the use of the above-mentioned specific mixed solvent is more conducive to maintaining the stability of the production solution and controlling the product quality.

[0013] Preferably, in step (1), the mass ratio of the polycarbonate, the electron transport material, the charge generating material, the dispersant and the first solvent is 100:(10-80):(20-70):(5-30):(1000-7000).

[0014] Preferably, the metal compound is selected from at least one of titanium oxide, zinc oxide, barium sulfate and iron oxide;

[0015] And / or, the particle size of the metal compound dispersion is 900 nm or less.

[0016] Preferably, in step (2), the second solvent comprises chlorobenzene and tetrahydrofuran in a mass ratio of 100:(300-800). The present invention adopts the above-mentioned specific mixed solvent, which makes the stability of the production solution and the change of saturated vapor pressure caused by the volatilization of the solvent in the production process more stable than other solvents, and the product quality is easier to control.

[0017] Preferably, in step (2), the mass ratio of the metal compound to the polycarbonate is 60:(30-120);

[0018] The added amount of the metal compound is 10 wt % to 40 wt % based on the mass of the second solvent.

[0019] Preferably, in step (3), the mass ratio of the metal compound dispersion to the coating liquid A is 10:(1000-7000).

[0020] Preferably, in step (3), the coating liquid B has a solid content of 10 wt% to 40 wt% and a viscosity of 800 mPa·s or more.

[0021] Preferably, in step (3), the coating liquid B is coated on the aluminum substrate to a thickness of 20 to 40 μm.

[0022] The present invention also provides a positive charging type highly wear-resistant organic photoconductive drum, which is prepared by the above preparation method.

[0023] Beneficial effects achieved by the present invention:

[0024] (1) The preparation method of the positive charging type highly wear-resistant organic photoconductive drum provided by the present invention significantly prolongs the service life of the drum core, has uniform image layers, and has excellent color density, which has broad demand and advantages in the current market prospects;

[0025] (2) In the method for preparing a positively charged highly wear-resistant organic photoconductive drum provided by the present invention, the metal compound is preferably selected from at least one of titanium oxide, zinc oxide, barium sulfate and iron oxide, and the addition amount is 10wt% to 40wt%. The present invention further increases the service life of the drum core by adjusting the above-mentioned types of metal compounds in corresponding proportions to prepare a coating liquid and applying it to a positively charged single-layer organic photoconductive drum;

[0026] (3) In the method for preparing the positively charged highly wear-resistant organic photoconductive drum provided by the present invention, the first solvent preferably comprises tetrahydrofuran, cyclohexanone and chlorobenzene in a mass ratio of 100:(50-70):(30-50). The use of the above-mentioned specific mixed solvent is more conducive to maintaining the stability of the production solution and controlling the product quality;

[0027] (4) In the method for preparing the positively charged highly wear-resistant organic photoconductive drum provided by the present invention, the second solvent preferably comprises chlorobenzene and tetrahydrofuran in a mass ratio of 100:(300-800). By adopting the above-mentioned specific mixed solvent, the stability of the production solution and the change in saturated vapor pressure caused by the volatilization of the solvent during the production process are more stable than other solvents, and the product quality is easier to control;

[0028] (5) In the preparation method of the positively charged highly wear-resistant organic photoconductive drum provided by the present invention, the dispersant is preferably silicone oil. Studies have found that silicone oil is particularly suitable for the present invention, and is more conducive to the dispersion of materials, reducing local aggregation, and ensuring the coating uniformity of the product during the production process. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical scheme and advantages of the embodiments of the present invention clearer, the technical scheme in the embodiments of the present invention is described clearly and completely below. The following embodiments are used to illustrate the present invention, but are not used to limit the scope of the present invention. If no specific technology or conditions are specified in the embodiments, the technology or conditions described in the literature in the field or the product instructions are used.

[0030] In the following examples, information of each reagent used is shown in Table 1.

[0031] Table 1 Information of reagents used in the examples

[0032] Reagents model factory Polycarbonate Bisphenol A Mitsubishi Chemical Corporation Electron transport materials m-TPD Mitsubishi Chemical Corporation Charge generation materials Titanium Phthalocyanine LG Chem Dispersants Dimethicone Mitsubishi Chemical Corporation

[0033] Example 1

[0034] Step A, adding polycarbonate, electron transport material, charge generating material, and dispersant to a first mixed solution of tetrahydrofuran, cyclohexanone, and chlorobenzene in a mass ratio of 100:50:45 in sequence, and obtaining a coating solution A after sufficient high-speed dispersion, dissolution, and uniform mixing; the mass ratio of polycarbonate, electron transport material, charge generating material, dispersant, and first mixed solvent is 100:60:20:5:3000;

[0035] Step B, adding a metal compound and a polycarbonate to a second mixed solution of chlorobenzene and tetrahydrofuran in a mass ratio of 100:500 in sequence, and obtaining a metal compound dispersion after high-speed dispersion; the metal compound is titanium dioxide, the mass ratio of the metal compound to the polycarbonate is 60:60, and the addition amount of the metal compound is 10wt% based on the mass of the second mixed solvent;

[0036] Step C: adding the metal compound dispersion to the coating solution A (the mass ratio of the metal compound dispersion to the coating solution A is 10:5000, and after stirring and mixing for 20 hours, a final coating solution B is obtained, and the coating solution B is coated on the aluminum substrate with a coating thickness of 35 μm. After drying at 150° C. for 90 minutes, a highly wear-resistant organic photoconductive drum is finally obtained.

[0037] Example 2

[0038] The only difference between Example 2 and Example 1 is that in step B, the amount of the metal compound added is 20 wt % based on the mass of the second mixed solvent.

[0039] Example 3

[0040] The only difference between Example 3 and Example 1 is that in step B, the amount of the metal compound added is 40 wt % based on the mass of the second mixed solvent.

[0041] Example 4

[0042] The only difference between Example 4 and Example 1 is that in step C, the coating thickness is 40 μm.

[0043] Comparative Example 1

[0044] The difference between Comparative Example 1 and Example 1 is that step B is omitted, and step C is to coat the coating liquid A on the aluminum substrate with a coating thickness of 35 μm, and dry at 150° C. for 90 minutes to finally obtain the organic photoconductive drum of Comparative Example 1.

[0045] Performance Characterization

[0046] The electrical performance of the organic photoconductive drums of Example 1, Example 2, Example 3 and Comparative Example 1 was tested by using a GENTEC electrical performance tester, and the results are shown in Table 2. The organic photoconductive drums of Example 1, Example 2, Example 3 and Comparative Example 1 were applied to a Lenovo LJ5000DN laser printer to perform a normal temperature life printing test, and the test results are shown in Table 3.

[0047] Photoelectric performance test: The OPC drums of the embodiments were tested using a GENTEC photoelectric performance tester; test conditions: temperature 20-30°C, relative humidity RH% 30-70; the sensitivity (E1 / 2), charging potential (V0), exposure potential (VR) and dark decay (DD) data obtained after the test were analyzed to evaluate the performance of the prepared positively charged OPC drum.

[0048] Actual machine printing test: The embodiment and comparative example were applied to the LJ5000DN laser printer for life printing test, and 50,000 pages were printed continuously to test the density change and film thickness change during the life of the OPC drum; test conditions: temperature / humidity (23±3)℃ / RH 50~60%.

[0049] Table 2

[0050]

[0051] Table 3

[0052] OPC Homepage density 50000 pages density Printing quality Coating wear Example 1 1.36 1.34 OK qualified Example 2 1.34 1.31 OK qualified Example 3 1.35 1.34 OK qualified Example 4 1.38 1.36 OK qualified Comparative Example 1 1.34 / NG Failure

[0053] Although the present invention has been described in detail above by general description, specific implementation methods and experiments, it is obvious to those skilled in the art that some modifications or improvements can be made to the present invention. Therefore, these modifications or improvements made without departing from the spirit of the present invention all belong to the scope of protection claimed by the present invention.

Claims

1. A method for preparing a positively charged highly wear-resistant organic photoconductive drum, characterized in that: The following steps are involved: (1) adding polycarbonate, electron transport material, charge generating material and dispersant into a first solvent, and after all the materials are dissolved and mixed uniformly, a coating solution A is obtained; (2) adding a metal compound and a polycarbonate into a second solvent to obtain a metal compound dispersion; (3) The metal compound dispersion and the coating liquid A are mixed evenly to obtain a coating liquid B, and the coating liquid B is coated on an aluminum substrate. After drying, a positively charged, highly wear-resistant organic photoconductive drum is obtained.

2. The preparation method according to claim 1, characterized in that: In step (1), the dispersant is selected from at least one of paraffin, silicone oil and polyethylene glycol.

3. The preparation method according to claim 1 or 2, characterized in that: In step (1), the first solvent comprises tetrahydrofuran, cyclohexanone and chlorobenzene in a mass ratio of 100:(50-70):(30-50); And / or, the mass ratio of the polycarbonate, the electron transport material, the charge generating material, the dispersant and the first solvent is 100:(10-80):(20-70):(5-30):(1000-7000).

4. The preparation method according to claim 1 or 2, characterized in that: In step (2), the metal compound is selected from at least one of titanium oxide, zinc oxide, barium sulfate and iron oxide; And / or, the particle size of the metal compound dispersion is 900 nm or less.

5. The preparation method according to claim 1 or 2, characterized in that: In step (2), the second solvent comprises chlorobenzene and tetrahydrofuran in a mass ratio of 100:(300-800).

6. The preparation method according to claim 1 or 2, characterized in that: In step (2), the mass ratio of the metal compound to the polycarbonate is 60:(30-120); The added amount of the metal compound is 10 wt % to 40 wt % based on the mass of the second solvent.

7. The preparation method according to claim 1 or 2, characterized in that: The mass ratio of the metal compound dispersion to the coating liquid A is 10:(1000-7000).

8. The preparation method according to claim 1 or 2, characterized in that: In step (3), the coating liquid B has a solid content of 10 wt% to 40 wt% and a viscosity of 800 mPa·s or more.

9. The preparation method according to claim 1 or 2, characterized in that: In step (3), the coating liquid B is coated on the aluminum substrate to a thickness of 20 to 40 μm.

10. A positively charged highly wear-resistant organic photoconductive drum, characterized in that: It is prepared by the preparation method according to any one of claims 1 to 9.

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