A charge transport layer coating with low visible light transmittance and a method for preparing the same

Abstract

The application discloses a charge transport layer coating with low visible light transmittance and a preparation method thereof, and belongs to the field of organic photoconductive drums. The charge transport layer coating comprises 1-5 parts of 9-anthracene formaldehyde diphenyl hydrazone, 5-10 parts of a silicone leveling agent, 60-120 parts of N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 100-150 parts of a carbonic acid resin, 500-800 parts of a tetrahydrofuran solution and 0.2-0.5 parts of tertiary amyl binaphthylquinone. The charge transport layer coating adds tertiary amyl binaphthylquinone, which can be uniformly dispersed in the charge transport layer solution, so that the solution changes from colorless and transparent to red-brown. When the charge transport layer solution is coated on the surface of a charge generation layer of a photosensitive drum to form a charge transport layer, the visible light transmittance can be reduced under the condition of guaranteeing electrical characteristics, the risk that the surface charging potential of the photosensitive drum is attenuated under light can be effectively reduced, and the service life and printing quality of the photosensitive drum are improved.

Description

Technical Field

[0001] This application relates to the field of organic photoconductor drum technology, specifically a charge transport layer coating with low visible light transmittance and its preparation method. Background Technology

[0002] Organic photoconductors (OPCs) are organic electronic devices. Laser printing technology utilizes the charge transport characteristics of organic photoconductors to form an electrostatic latent image on the surface of OPCs, which is then "developed" to form a printed image. Meanwhile, the photosensitive drum is the most critical electrical conversion and imaging component in modern office equipment such as digital copiers, laser fax machines, and multifunction printers, directly determining the quality of image transmission such as printing and copying.

[0003] Materials commonly used in the charge generation layer of organic photoconductive drums include phthalocyanine compounds and diazo salts. The photoconductive properties of phthalocyanine compounds are closely related to their molecular structure. Their unique conjugated structure causes them to produce two strong absorption bands in the ultraviolet and visible absorption spectra: the Soret band in the near-ultraviolet region (300-400 nm) and the Q band in the visible region (650-670 nm). The Q band is the strongest and highest-resolution absorption band among phthalocyanine compounds. Meanwhile, commonly used TiOPc has strong light absorption characteristics in the 600-900 nm range. The advantages of azo compounds as organic photoconductive materials are that they are suitable for low-cost manufacturing techniques, have excellent photosensitivity, have a spectral response in a wide range of 400-800 nm, and have good photoelectric stability.

[0004] Titanium phthalocyanine (Pphthalocyanine) exhibits strong absorption in the 600–850 nm range, making it suitable for 630–670 nm LED light sources and 780 nm laser light sources. However, when an uncharged OPC is exposed to light, the charge generation layer generates charge, which is detrapped during the OPC charging process, leading to a decay in the surface charge potential. In actual OPC assembly and disassembly, the OPC surface is partially exposed to light. Due to the aforementioned reasons, the exposed portion prints a darker color with a periodic pattern, affecting the lifespan of the photosensitive drum and print quality.

[0005] Therefore, this application provides a charge transport layer coating with low visible light transmittance and a method for preparing the same, in order to solve the above-mentioned problems. Summary of the Invention

[0006] This application provides a charge transport layer coating with low visible light transmittance and its preparation method, aiming to solve the problem mentioned in the background art that when the existing photosensitive drum is exposed to light without charging, the surface charging potential decays, which easily leads to darker printed colors, affecting the service life and printing quality of the photosensitive drum.

[0007] To achieve the above objectives, in one aspect, this application provides a charge transport layer coating with low visible light transmittance, the charge transport layer coating comprising the following components in parts by mass:

[0008]

[0009] Preferably, the silicone oil leveling agent is obtained by dispersing silicone oil in a tetrahydrofuran solution.

[0010] Preferably, the silicone oil content in the silicone oil leveling agent is 1%.

[0011] Preferably, the resin is a carbonate resin.

[0012] Preferably, the solvent is a tetrahydrofuran solution.

[0013] On the other hand, this application provides a method for preparing a charge transport layer coating with low visible light transmittance. This method is used to prepare the aforementioned charge transport layer coating and includes the following steps:

[0014] 1) Slowly add 100-150 parts of resin to 500-800 parts of tetrahydrofuran solution, stir and mix evenly to obtain intermediate solution A;

[0015] 2) Slowly add 60-120 parts of N,N'-diphenyl-N,N'-bis(p-tolyl)benzidine, 1-5 parts of 9-anthracarbaldehyde diphenylhydrazone and 0.2-0.5 parts of tert-amylbinazone to solution A to prepare intermediate solution B;

[0016] 3) Add 5-10 parts of silicone oil leveling agent to solution B, stir and mix evenly, then filter the solution to obtain the charge transport layer coating.

[0017] Preferably, in step 2), the solution must be stirred during the addition of materials to ensure complete dissolution of the materials.

[0018] Preferably, in step 3), after the mixture is stirred and homogenized, the solution is filtered through a vacuum filtration device to obtain the charge transport layer coating.

[0019] This charge transport layer coating incorporates tert-amylbinazone, which disperses uniformly in the charge transport layer solution, transforming the solution from colorless and transparent to reddish-brown. Applying this solution to the charge generation layer surface of the photosensitive drum forms the charge transport layer. This reduces visible light transmittance while maintaining electrical properties, effectively mitigating the risk of surface charge potential decay under illumination, thereby improving the drum's lifespan and print quality. Detailed Implementation

[0020] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the examples. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0021] In this application, the vacuum filtration device is a vacuum negative pressure container connected to the reactor. The vacuum negative pressure container has a filter medium (filter cloth). Under its negative pressure, the effective part of the solution in the reactor is filtered through the filter cloth, while large particles and impurities are intercepted by the filter cloth, thereby achieving the filtration of the solution.

[0022] Example 1

[0023] This embodiment provides a charge transport layer coating with low visible light transmittance. The charge transport layer coating comprises 1 part of 9-anthracene formaldehyde diphenylhydrazone, 5 parts of silicone oil leveling agent, 70 parts of N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 100 parts of carbonate resin, 750 parts of tetrahydrofuran solution, and 0.2 parts of tert-amylbinaquinone.

[0024] The preparation method of this charge transport layer coating includes the following steps:

[0025] 1) Slowly add 100 parts of carbonate resin to 750 parts of tetrahydrofuran solution, stir and mix evenly to obtain intermediate solution A;

[0026] 2) Slowly add 70 parts of N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 1 part of 9-anthracarbaldehyde diphenylhydrazone, and 0.2 parts of tert-amylbinazone to solution A in sequence; wherein, when adding N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 9-anthracarbaldehyde diphenylhydrazone, and tert-amylbinazone, the solution needs to be stirred to ensure that the added N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 9-anthracarbaldehyde diphenylhydrazone, and tert-amylbinazone are completely dissolved to obtain intermediate solution B;

[0027] 3) Add 5 parts of silicone oil leveling agent to solution B, stir and mix evenly, and then filter the solution through a vacuum filter to obtain the charge transport layer coating.

[0028] Example 2

[0029] This embodiment provides a charge transport layer coating with low visible light transmittance. The charge transport layer coating comprises 1 part of 9-anthracene formaldehyde diphenylhydrazone, 5 parts of silicone oil leveling agent, 70 parts of N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 100 parts of carbonate resin, 750 parts of tetrahydrofuran solution, and 0.35 parts of tert-amylbinaquinone.

[0030] The preparation method of this charge transport layer coating includes the following steps:

[0031] 1) Slowly add 100 parts of carbonate resin to 750 parts of tetrahydrofuran solution, stir and mix evenly to obtain intermediate solution A;

[0032] 2) Slowly add 70 parts of N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 1 part of 9-anthracarbaldehyde diphenylhydrazone, and 0.35 parts of tert-amylbinazone to solution A in sequence; wherein, when adding N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 9-anthracarbaldehyde diphenylhydrazone, and tert-amylbinazone, the solution needs to be stirred to ensure that the added N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 9-anthracarbaldehyde diphenylhydrazone, and tert-amylbinazone are completely dissolved to obtain intermediate solution B;

[0033] 3) Add 5 parts of silicone oil leveling agent to solution B, stir and mix evenly, and then filter the solution through a vacuum filter to obtain the charge transport layer coating.

[0034] Example 3

[0035] This embodiment provides a charge transport layer coating with low visible light transmittance. The charge transport layer coating comprises 1 part 9-anthracene formaldehyde diphenylhydrazone, 5 parts silicone oil leveling agent, 70 parts N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 100 parts carbonate resin, 750 parts tetrahydrofuran solution, and 0.5 parts tert-amylbinaquinone.

[0036] The preparation method of this charge transport layer coating includes the following steps:

[0037] 1) Slowly add 100 parts of carbonate resin to 750 parts of tetrahydrofuran solution, stir and mix evenly to obtain intermediate solution A;

[0038] 2) Slowly add 70 parts of N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 1 part of 9-anthracarbaldehyde diphenylhydrazone, and 0.5 parts of tert-pentylbinazone to solution A in sequence; wherein, when adding N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 9-anthracarbaldehyde diphenylhydrazone, and tert-pentylbinazone, the solution needs to be stirred to ensure that the added N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 9-anthracarbaldehyde diphenylhydrazone, and tert-pentylbinazone are completely dissolved to obtain intermediate solution B;

[0039] 3) Add 5 parts of silicone oil leveling agent to solution B, stir and mix evenly, and then filter the solution through a vacuum filter to obtain the charge transport layer coating.

[0040] Examples 1, 2, and 3 were coated onto the surface of an aluminum substrate tube that already had a charge blocking layer and a charge generating layer by dip coating, and then dried in an oven at 120°C for 40 minutes to form a 28µm thick charge transport layer coating, thus obtaining a photosensitive drum.

[0041] Comparative Example 1

[0042] The difference between this comparative example and Examples 1, 2 and 3 is that the amount of tert-amylbinaphthoquinone added is 0.

[0043] Comparative Example 2

[0044] The composition of the charge transport layer coating in this comparative example is the same as that in Comparative Example 1.

[0045] Comparative Example 3

[0046] The difference between this comparative example and Comparative Example 1, Example 1, Example 2 and Example 3 is that the amount of tert-amylbinaphthoquinone added is 0.65 parts.

[0047] Experimental data

[0048] 1) The surface potential and residual potential of the photosensitive drums prepared in Examples 1, 2, 3, Comparative Example 1, and Comparative Example 3 were compared after being fully exposed to a fluorescent lamp for 30 minutes. The results were measured using a PDT-2000 at an exposure energy of 0.12. The results are shown in the table below.

[0049]

[0050] As shown in the table above, after adding a certain amount of tert-amylbinaphthylquinone, the photosensitive drum has a speed of 0.12 uJ / cm. 2 The surface potential and residual potential under exposure energy are higher than those of the photosensitive drum without tert-amylbinazone, and the higher the amount of tert-amylbinazone added, the higher the values ​​of both. Therefore, adding a certain amount of tert-amylbinazone can effectively reduce the influence of sunlight on the electrical performance of the photosensitive drum; and within a certain range, the effect of reducing the influence of sunlight on the electrical performance of the photosensitive drum becomes more obvious with the increase of the amount of tert-amylbinazone added.

[0051] 2) The photosensitive drums prepared in Examples 1, 2, 3, Comparative Example 1, and Comparative Example 3 were packaged with light-shielding paper. The same size and pattern were cut from the same location on the packaging paper, and the drums were exposed to a fluorescent lamp for 5 minutes to simulate partial exposure of the photosensitive drum. The photosensitive drums were then placed in a printer to print 100% black pages. The print density of the exposed and unexposed areas was compared, as shown in the table below:

[0052]

[0053]

[0054] As shown in the table above, the printing concentration in the exposed area is lower than that without the addition of this substance after adding a certain amount of tert-amylbinaphthylquinone. The greater the amount added, the closer the printing concentration in the exposed area is to that in the unexposed area. Therefore, adding a certain amount of tert-amylbinaphthylquinone can effectively reduce the printing concentration in the exposed area; and within a certain range, the effect of reducing the printing concentration is more obvious as the amount of tert-amylbinaphthylquinone added increases.

[0055] In summary, when the amount of tert-amyl-binaphthylquinone added reaches 0.2 parts or more, the photosensitive drum's efficiency (0.12 uJ / cm) increases with the amount of tert-amyl-binaphthylquinone added. 2 The surface potential and residual potential increase under exposure energy, and the printing density in the exposed area tends to be closer to that in the unexposed area. When the amount of tert-amylbinaphthylquinone added reaches 0.5 parts or more, the photosensitive drum has a density of 0.12 uJ / cm. 2 The surface potential and residual potential under exposure energy are similar, and the printing density in the exposed area tends to be consistent with that in the unexposed area. Therefore, adding 0.2–0.5 parts of tert-amylbinaphthoquinone can effectively reduce the impact of fluorescent lamp exposure on the electrical and printing performance of the photosensitive drum, effectively improve the exposure resistance of the photosensitive drum, and improve the quality of the photosensitive drum.

[0056] The above description is merely a preferred embodiment of this application, but the scope of protection of this application is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this application, based on the technical solution and concept of this application, should be included within the scope of protection of this application.

Claims

1. A charge transport layer coating with low visible light transmittance, characterized in that, The charge transport layer coating comprises the following components in parts by mass: 1-5 parts of 9-anthracarbaldehyde diphenylhydrazone; 5-10 parts of silicone oil leveling agent; 60-120 parts of N,N'-diphenyl-N,N'-di(p-tolyl)benzidine; 100-150 parts of carbonate resin; Solvent 500-800 parts; 0.2–0.5 parts of tert-amyl binaphthone.

2. The charge transport layer coating with low visible light transmittance according to claim 1, characterized in that, The silicone oil leveling agent is obtained by dispersing silicone oil in a tetrahydrofuran solution.

3. The charge transport layer coating with low visible light transmittance according to claim 2, characterized in that, The silicone oil leveling agent contains 1% silicone oil.

4. The charge transport layer coating with low visible light transmittance according to claim 1, characterized in that, The solvent is a tetrahydrofuran solution.

5. A method for preparing a charge transport layer coating with low visible light transmittance, characterized in that: The preparation method is used to prepare the charge transport layer coating according to any one of claims 1-4, and the preparation method includes the following steps: 1) Slowly add 100-150 parts of resin to 500-800 parts of tetrahydrofuran solution, stir and mix evenly to obtain intermediate solution A; 2) Slowly add 60-120 parts of N,N'-diphenyl-N,N'-bis(p-tolyl)benzidine, 1-5 parts of 9-anthracarbaldehyde diphenylhydrazone, and 0.2-0.5 parts of tert-amylbinazone to solution A to prepare intermediate solution B; 3) Add 5-10 parts of silicone oil leveling agent to solution B, stir and mix evenly, then filter the solution to obtain the charge transport layer coating.

6. The method for preparing the charge transport layer coating with low visible light transmittance according to claim 5, characterized in that: In step 2), the solution must be stirred during the addition of materials to ensure complete dissolution.

7. The method for preparing the charge transport layer coating with low visible light transmittance according to claim 5, characterized in that: In step 3), after stirring and mixing evenly, the solution is filtered through a vacuum filtration device to obtain the charge transport layer coating.

Images