Charge transport layer coating with low visible light transmittance and preparation method thereof

Abstract

The invention discloses a charge transport layer coating with low visible light transmittance and a preparation method thereof, and belongs to the field of organic photoconductor drums, the charge transport layer coating comprises 1-5 parts of 9-anthracene formaldehyde diphenyl hydrazone, 5-10 parts of a silicone oil leveling agent, 60-120 parts of N, N '-diphenyl-N, N'-di (p-tolyl) benzidine, 100-150 parts of carbonic acid resin, 500-800 parts of a tetrahydrofuran solution and 0.2-0.5 part of tert-amyl dinaphthoquinone. According to the charge transport layer coating, tert-amyl dinaphthoquinone is added, tert-amyl dinaphthoquinone can be uniformly dispersed in a charge transport layer solution, so that the solution is changed into reddish brown from colorless and transparent, the charge transport layer coating is used as the charge transport layer solution to be coated on the surface of a charge generation layer of a photosensitive drum to form a charge transport layer, and the charge transport layer can be formed under the condition of ensuring electrical characteristics. The risk of surface charging potential attenuation of the photosensitive drum under illumination can be effectively reduced, so that the service life of the photosensitive drum is prolonged, and the printing quality of the photosensitive drum is improved.

Description

Technical Field

[0001] The present application relates to the technical field of organic photoconductive drums, and in particular to a charge transport layer coating with low visible light transmittance and a preparation method thereof. Background Art

[0002] Organic photoconductor (OPC) is an organic electronic device. Laser printing technology uses the charge transfer characteristics of organic photoelectric semiconductors to form an electrostatic latent image on the OPC surface, which is then "developed" to form a printed image. At the same time, the photosensitive drum is the core electrical conversion and imaging component in modern office equipment such as digital copiers, laser fax machines and multifunction printers, which directly determines the quality of image transmission such as printing and copying.

[0003] The materials generally used in the charge generation layer of the organic photosensitive drum include phthalocyanine compounds, disazo salts and other substances. The photoconductivity of phthalocyanine compounds is closely related to their molecular structure. Their special conjugated structure causes them to produce two strong absorption bands in the ultraviolet and visible absorption spectra, namely the Soret band of 300-400nm in the near-ultraviolet region and the Q band of 650-670nm in the visible light region. The Q band is the strongest and highest-resolution absorption band in phthalocyanine compounds. At the same time, the commonly used TiOPc has strong light absorption characteristics in the range of 600-900nm. The advantage of azo compounds as organic photoconductive materials is that they are suitable for low-cost manufacturing technology, have very good photosensitivity, have spectral response in a wide range of 400-800nm, and have good photoelectric stability.

[0004] Phthalocyanine titanium has strong absorption at 600-850nm, and is suitable for 630-670nm LED light source and 780nm laser light source; however, when the uncharged OPC is exposed to light, the charge generation layer will generate charge, and will be de-trapped during the OPC charging process, resulting in the decay of the surface charge potential. During the actual disassembly and assembly of the OPC, the OPC surface will be partially exposed to light. Due to the above reasons, the print color of the exposed part is darker and periodic, which affects the service life of the photosensitive drum and the printing quality.

[0005] Therefore, the present application provides a charge transport layer coating with low visible light transmittance and a preparation method thereof to solve the above problems. Summary of the invention

[0006] The present application provides a charge transport layer coating with low visible light transmittance and a preparation method thereof, aiming to solve the problem in the background technology that when the existing photosensitive drum is exposed to light when not charged, the surface charging potential decays, which easily leads to dark printing colors, affecting the service life and printing quality of the photosensitive drum.

[0007] To achieve the above objectives, on the one hand, the present 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 content of silicone oil in the silicone oil leveling agent is 1%.

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

[0012] Preferably, the solvent is tetrahydrofuran solution.

[0013] On the other hand, the present application provides a method for preparing a charge transport layer coating with low visible light transmittance, the preparation method is used to prepare the above-mentioned charge transport layer coating, and the preparation method comprises the following steps:

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

[0015] 2) Slowly adding 60-120 parts of N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 1-5 parts of 9-anthracenecarboxaldehyde diphenylhydrazone and 0.2-0.5 parts of tert-amylbinaphthoquinone to solution A in sequence to prepare an intermediate solution B;

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

[0017] Preferably, in step 2), when adding materials, the solution needs to be stirred to completely dissolve the materials.

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

[0019] The charge transport layer coating is prepared by adding tert-amyl binaphthoquinone, which can be evenly dispersed in the charge transport layer solution, so that the solution changes from colorless and transparent to reddish brown. The charge transport layer solution is coated on the surface of the charge generation layer of the photosensitive drum to form a charge transport layer. The charge transport layer can reduce the transmittance of visible light while ensuring the electrical properties, and can effectively reduce the risk of surface charging potential decay of the photosensitive drum under light, thereby improving the service life and printing quality of the photosensitive drum. DETAILED DESCRIPTION

[0020] The following will be combined with the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

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

[0022] Example 1

[0023] The present embodiment provides a charge transport layer coating with low visible light transmittance, which includes 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-amyl dinaphthoquinone.

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

[0025] 1) Slowly adding 100 parts of carbonate resin to 750 parts of tetrahydrofuran solution, stirring and mixing to obtain intermediate solution A;

[0026] 2) slowly adding 70 parts of N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 1 part of 9-anthracenecarboxaldehyde diphenylhydrazone and 0.2 parts of tert-amylbinaphthoquinone to solution A in sequence; wherein, when adding N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 9-anthracenecarboxaldehyde diphenylhydrazone and tert-amylbinaphthoquinone, the solution needs to be stirred to completely dissolve the added N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 9-anthracenecarboxaldehyde diphenylhydrazone and tert-amylbinaphthoquinone, to obtain an 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 filtration device to obtain a charge transport layer coating.

[0028] Example 2

[0029] The present embodiment provides a charge transport layer coating with low visible light transmittance, which includes 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-amyl dinaphthoquinone.

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

[0031] 1) Slowly adding 100 parts of carbonate resin to 750 parts of tetrahydrofuran solution, stirring and mixing to obtain intermediate solution A;

[0032] 2) slowly adding 70 parts of N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 1 part of 9-anthracenecarboxaldehyde diphenylhydrazone and 0.35 parts of tert-amylbinaphthoquinone to solution A in sequence; wherein, when adding N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 9-anthracenecarboxaldehyde diphenylhydrazone and tert-amylbinaphthoquinone, the solution needs to be stirred to completely dissolve the added N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 9-anthracenecarboxaldehyde diphenylhydrazone and tert-amylbinaphthoquinone, to obtain an 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 filtration device to obtain a charge transport layer coating.

[0034] Example 3

[0035] The present embodiment provides a charge transport layer coating with low visible light transmittance, the charge transport layer coating comprising 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 0.5 parts of tert-amyl dinaphthoquinone

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

[0037] 1) Slowly adding 100 parts of carbonate resin to 750 parts of tetrahydrofuran solution, stirring and mixing to obtain intermediate solution A;

[0038] 2) slowly adding 70 parts of N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 1 part of 9-anthracenecarboxaldehyde diphenylhydrazone and 0.5 parts of tert-amylbinaphthoquinone to solution A in sequence; wherein, when adding N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 9-anthracenecarboxaldehyde diphenylhydrazone and tert-amylbinaphthoquinone, the solution needs to be stirred to completely dissolve the added N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 9-anthracenecarboxaldehyde diphenylhydrazone and tert-amylbinaphthoquinone, to obtain an 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 filtration device to obtain a charge transport layer coating.

[0040] Example 1, Example 2 and Example 3 were respectively coated on the surface of the aluminum substrate tube coated with the charge blocking layer and the charge generating layer by dip coating, and dried in an oven at 120° C. for 40 min to form a 28 μm thick charge transport layer coating to prepare a photosensitive drum.

[0041] Comparative Example 1

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

[0043] Comparative Example 2

[0044] The components of the charge transport layer coating in this comparative example are the same as those 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 added amount of tert-amyl binaphthoquinone is 0.65 parts.

[0047] Experimental data

[0048] 1) After the surfaces of the photosensitive drums prepared in the above-mentioned Examples 1, 2, 3, Comparative Examples 1 and 3 were fully exposed to fluorescent lamps for 30 minutes, the surface potential and residual potential at 0.12 exposure energy were measured by PDT-2000 and compared, as shown in the following table:

[0049]

[0050] From the table above, we can see that after adding a certain amount of tert-amyl binaphthoquinone, the photosensitive drum is 0.12uj / cm 2 The surface potential and residual potential under exposure energy are higher than those of the photosensitive drum without tert-amyl binaphthoquinone, and the greater the amount of addition, the higher the values ​​of the two. Therefore, adding a certain amount of tert-amyl binaphthoquinone can effectively reduce the influence of sunlight on the electrical properties of the photosensitive drum; and within a certain range, as the amount of tert-amyl binaphthoquinone added increases, the effect of reducing the influence of sunlight on the electrical properties of the photosensitive drum becomes more obvious.

[0051] 2) The photosensitive drums prepared in the above-mentioned Example 1, Example 2, Example 3, Comparative Example 1 and Comparative Example 3 were wrapped with light-shielding paper, the same size and pattern were cut at the same position of the wrapping paper, and exposed under a fluorescent lamp for 5 minutes to simulate partial exposure of the photosensitive drum. The photosensitive drum was placed in a printer to print a 100% black page, and the print density of the exposed area and the unexposed area was compared, as shown in the following table:

[0052]

[0053]

[0054] As can be seen from the table above, after adding a certain amount of tert-amyl binaphthoquinone, the print density of the exposed area is lower than that of the area without adding the substance. The greater the amount added, the closer the print density of the exposed area is to the print density of the unexposed area. Therefore, adding a certain amount of tert-amyl binaphthoquinone can effectively reduce the print density of the exposed area; and within a certain range, as the amount of tert-amyl binaphthoquinone added increases, the effect of reducing the print density is more obvious.

[0055] In summary, when the amount of tert-amyl binaphthoquinone added reaches more than 0.2 parts, as the amount of tert-amyl binaphthoquinone added increases, the photosensitive drum 0.12uj / cm 2 The surface potential and residual potential under exposure energy increase, and the printing density of the exposed area tends to be closer to the printing density of the unexposed area. When the addition amount of tert-amyl dinaphthoquinone reaches more than 0.5 parts, the photosensitive drum is 0.12uj / cm 2 The surface potential and residual potential under exposure energy, and the printing density of the exposed area is consistent with the printing density of the unexposed area. Therefore, after adding 0.2 to 0.5 parts of tert-amyl binaphthoquinone, the influence of fluorescent lamp exposure on the electrical properties and printing performance of the photosensitive drum can be effectively reduced, and the anti-exposure ability of the photosensitive drum can be effectively improved, thereby improving the quality of the photosensitive drum.

[0056] The above is only a preferred specific implementation manner of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can make equivalent substitutions or changes according to the technical solution and concept of the present application within the technical scope disclosed in the present application, which should be covered by the protection scope of the present 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:

2. The charge transport layer coating material 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 material with low visible light transmittance according to claim 2, characterized in that: The content of silicone oil in the silicone oil leveling agent is 1%.

4. The charge transport layer coating material with low visible light transmittance according to claim 1, characterized in that: The resin is a carbonate resin.

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

6. 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 to 5, and the preparation method comprises the following steps: 1) Slowly add 100 to 150 parts of resin to 500 to 800 parts of tetrahydrofuran solution, stir and mix evenly to prepare intermediate solution A; 2) Slowly adding 60-120 parts of N,N'-diphenyl-N,N'-di(p-tolyl)benzidine, 1-5 parts of 9-anthracenecarboxaldehyde diphenylhydrazone and 0.2-0.5 parts of tert-amylbinaphthoquinone to solution A in sequence to prepare an intermediate solution B; 3) Add 5 to 10 parts of silicone oil leveling agent to solution B, stir and mix evenly, and then filter the solution to obtain a charge transport layer coating.

7. The method for preparing a charge transport layer coating with low visible light transmittance according to claim 6, characterized in that: In step 2), when adding materials, the solution needs to be stirred to completely dissolve the materials.

8. The method for preparing a charge transport layer coating with low visible light transmittance according to claim 6, characterized in that: In step 3), after stirring and mixing evenly, the solution is filtered through a vacuum filtration device to obtain a charge transport layer coating.

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