Modified polycarbonate coating for photosensitive drum and preparation method thereof

Abstract

The invention relates to the technical field of coatings, and discloses a modified polycarbonate coating for a photosensitive drum and a preparation method thereof.The modified polycarbonate coating for the photosensitive drum comprises the following raw materials in parts by weight: 74.95-81.99 parts of a solvent, 10-15 parts of modified polycarbonate resin, 8-10 parts of a charge transport material and 0.01-0.05 part of silicone oil, the preparation method comprises the following steps: adding the modified polycarbonate resin into a tetrahydrofuran solvent, stirring and dispersing, adding the charge transport material and the silicone oil, and stirring and mixing uniformly to obtain the modified polycarbonate coating for the photosensitive drum. The prepared modified polycarbonate coating can solve the problem of bottom ash caused by long-time charging and discharging in the prior art, and has a wide application prospect in photosensitive drums.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of coating, in particular to a modified polycarbonate coating for a photosensitive drum and a preparation method thereof. BACKGROUND

[0002] With the increasing speed of printers and multifunctional machines, the service life requirement is getting longer and longer, and the photoelectric performance requirement of the photosensitive drum (OPC) is also getting higher and higher. However, during use, the printed matter surface will appear bottom ash. This bottom ash is caused by the low charge transfer efficiency, that is, after rapid continuous printing, the charging potential of the OPC is greatly different from the original charging potential, and under a certain charging voltage, the original charging potential does not reach the predetermined value, which will cause the phenomenon of bottom ash on the printed matter surface. On the other hand, after the coating is worn, the electric charge cannot be normally released, resulting in the adsorption of residual electric charge to carbon powder, thereby causing bottom ash.

[0003] The charge transfer substance used in the traditional charge transfer layer is TPD (N,N'-diphenyl-N,N'-di(p-tolyl)phenylamine), and its transfer rate is 1.1×10 -5 cm 2 / V·S, which is relatively slow, and as the thickness increases, the original charging potential cannot meet the requirements, and the printed matter surface is prone to bottom ash, which cannot guarantee the durability while ensuring the printing quality. Polycarbonate (PC) is a commonly used resin for photosensitive drums, and its insulating property is good under continuous exposure conditions, and it is easier to maintain the surface potential, but its wear resistance is poor. SUMMARY

[0004] (I) Technical problems solved In view of the problems of low charge transfer efficiency and poor wear resistance of the coating in the prior art, which cause bottom ash after long time charging and discharging, the present application provides a modified polycarbonate coating for a photosensitive drum and a preparation method thereof. By using a charge transfer agent with faster charge transfer rate and a modified polycarbonate resin with better fatigue resistance, the surface potential can be maintained basically unchanged under the condition of continuous charging and discharging, thereby solving the problem of bottom ash.

[0005] (II) Technical solutions A modified polycarbonate coating for a photosensitive drum, the modified polycarbonate coating for a photosensitive drum comprises the following raw materials by weight: 74.95-81.99 parts by weight of tetrahydrofuran solvent, 10-15 parts by weight of modified polycarbonate resin, 8-10 parts of charge transfer material, 0.01-0.05 parts of silicone oil; The preparation method of the modified polycarbonate coating for a photosensitive drum comprises the following steps: The modified polycarbonate resin is added into tetrahydrofuran solvent, stirred and dispersed, and then a charge transport material and silicone oil are added and stirred to obtain a modified polycarbonate coating for a photosensitive drum.

[0006] The silicone oil can reduce the surface roughness of the charge transport layer of the photosensitive drum, and the modified polycarbonate prepared by the method of the present application contains a siloxane structure, which can not only have good compatibility with the silicone oil, but also can reduce the surface wear in the printing process of the photosensitive drum together with the silicone oil, thereby indirectly improving the surface potential maintenance capability.

[0007] Preferably, the charge transport material is 4-(2,2-diphenylvinyl)-N,N-di-p-tolyl aniline, which has a faster charge transport rate than traditional charge transport materials, can reduce the response time of the photosensitive layer, and further reduce the fatigue problem in the continuous charging-exposure-charging cycle process.

[0008] Preferably, the preparation method of the modified polycarbonate resin comprises the following steps: (1) 3,5-dihydroxybenzaldehyde and aminopropyl triethoxysilane are added into an ethanol solution, and refluxed for 5-8 hours under the protection of argon. After the reaction is completed, the product is dried to obtain phenolic hydroxyl silane. The amount ratio of 3,5-dihydroxybenzaldehyde to aminopropyl triethoxysilane is 1g:(1.6-1.8)g. In this reaction, the aldehyde group in 3,5-dihydroxybenzaldehyde reacts with the amino group in aminopropyl triethoxysilane through Schiff base reaction to obtain phenolic hydroxyl silane, and the reaction formula is as follows: ; (2) Graphene oxide and 66.7% acetic acid aqueous solution are added into a tetrahydrofuran solution, stirred and dispersed, and then phenolic hydroxyl silane is added at 70-75°C and refluxed for 20-24 hours. After the reaction is completed, the product is washed with deionized water and dried to obtain phenolic hydroxyl hyperbranched polysilane grafted graphene oxide. The amount ratio of graphene oxide to phenolic hydroxyl silane is 1g:(10-15)g.

[0009] In this reaction, the ethoxyl group in the phenolic hydroxyl silane is hydrolyzed to form silanol, which can be bonded to the hydroxyl group on the surface of graphene oxide through hydrogen bond, and then dehydrated and condensed. The remaining hydroxyl groups on the silanol are dehydrated and condensed with the silanols generated by the hydrolysis of other phenolic hydroxyl silanes, and the dehydrated and condensed reaction is repeated to form a hyperbranched structure, thereby obtaining phenolic hydroxyl hyperbranched polysilane grafted graphene oxide, i.e. a polysilane film containing terminal phenolic hydroxyl groups is formed on the surface of graphene oxide, which can reduce the agglomeration degree of graphene oxide and enhance its dispersion effect.

[0010] (3) Diphenyl carbonate, bisphenol A, lithium acetate, phenolic hydroxyl hyperbranched polysilane grafted graphene oxide are added into a flask, nitrogen is introduced, the reaction is carried out at 200 DEG C for 3-5 h, after the reaction is completed, the temperature is reduced to room temperature, dichloromethane is used for dissolution, n-hexane is used for washing, and drying is carried out, to obtain a modified polycarbonate resin; the amount ratio of diphenyl carbonate, bisphenol A, lithium acetate, phenolic hydroxyl hyperbranched polysilane grafted graphene oxide is 1g:(1-1.2)g:(0.00012-0.00015)g:(0.01-0.05)g.

[0011] In the reaction, the phenolic hydroxyl in the phenolic hydroxyl hyperbranched polysilane grafted graphene oxide is used to react with the monomer of PC, which is not simple physical blending, but embedding the structure containing graphene oxide into the polycarbonate molecular chain, reducing the precipitation of graphene oxide and improving the compatibility with polycarbonate, so that the graphene oxide is uniformly dispersed in the polycarbonate molecular chain, firstly, the graphene oxide has charge transport performance, which makes up for the defect that the polycarbonate has no charge transport performance, and in the process of preparing the modified polycarbonate coating for the photosensitive drum, it can assist other charge transport materials to form a huge charge transport path, thereby improving the charge transport efficiency, secondly, the uniformly dispersed graphene oxide can improve the mechanical properties of polycarbonate, and the hyperbranched phenolic hydroxyl structure contained on the surface of graphene oxide can react with other PC monomers to form a dense crosslinked network structure, which can also improve the mechanical properties of the material, that is, the graphene oxide can act as a stress concentration point, and the dense crosslinked network structure can act as a stress dispersion structure, both of which can absorb and disperse stress, thereby improving the mechanical properties and wear resistance of the material, that is, the surface potential can remain basically unchanged under the condition of continuous charging and discharging for a long time, thereby solving the problem of bottom ash.

[0012] (Three) beneficial technical effects The modified polycarbonate resin prepared by the application can reduce the agglomeration degree of graphene oxide, improve the compatibility of graphene oxide with the coating in the process of preparing the coating, utilize the charge transport effect of graphene oxide and the charge transport material to form a uniformly dispersed charge transport network structure in the coating, and synergistically improve the charge transport efficiency, and the phenolic hydroxyl hyperbranched polysilane grafted graphene oxide prepared by the application can produce a large dense crosslinked network structure when polymerized with PC monomers, which can synergistically improve the mechanical properties of the coating with graphene oxide, thereby improving the wear resistance of the coating.

[0013] The application promotes the charge transport efficiency of the paint by using the charge transport network structure formed by graphene oxide and charge transport materials, promotes the wear resistance of the paint by the crosslinking network structure, graphene oxide structure and silicone oil, that is, the application can maintain the surface potential basically unchanged under the condition of continuous charging and discharging by using the charge transport network knot with faster charge transport rate and the modified polycarbonate resin with better fatigue resistance, thereby solving the problem of bottom ash. DETAILED DESCRIPTION

[0014] The technical solutions in the embodiments of the application will be clearly and completely described below in combination with the embodiments of the application. Obviously, the described embodiments are some of the embodiments of the application, rather than all the embodiments of the application. Based on the embodiments in the application, all other embodiments obtained by those skilled in the art without creative work fall within the protection scope of the application.

[0015] The preparation method of the graphene oxide is as follows: 1.5 g of graphite, 9 g of potassium permanganate are added into a flask, then a mixed solution of 180 mL of H2SO4 and 20 mL of H3PO4 is added into the flask, stirring is conducted at 50 DEG C for 12 h, after the reaction is completed, the temperature is cooled to room temperature, a mixed solution of 200 g of ice water and 1.5 g of H2O2 is added into the flask, stirring is conducted, centrifugation is conducted, deionized water, 30% hydrochloric acid aqueous solution and ethanol are used in sequence for mixing, centrifugation is conducted, the filtrate is filtered, the filter residue is reserved, then the filter residue is mixed with diethyl ether, filtration is conducted, and drying is conducted, thereby obtaining the graphene oxide.

[0016] Embodiment 1 (1) 1 g of 3,5-dihydroxybenzaldehyde and 1.6 g of aminopropyl triethoxysilane are added into an ethanol solution, reflux reaction is conducted under the protection of argon for 8 h, after the reaction is completed, drying is conducted, thereby obtaining Phenolic hydroxy silane ; (2) 0.1 g of graphene oxide and 0.6 g of 66.7% acetic acid aqueous solution are added into a tetrahydrofuran solution, stirring and dispersion are conducted, 1 g of phenolic hydroxyl silane is added into the solution at 75 DEG C, reflux reaction is conducted for 22 h, after the reaction is completed, deionized water washing and drying are conducted, thereby obtaining phenolic hydroxyl hyperbranched polysilane grafted graphene oxide; (3) 10 g of diphenyl carbonate, 10 g of bisphenol A, 0.0012 g of lithium acetate, 0.1 g of phenolic hydroxyl hyperbranched polysilane grafted graphene oxide are added into a flask, nitrogen is introduced, reaction is conducted at 200 DEG C for 3 h, after the reaction is completed, the temperature is reduced to room temperature, dissolution is conducted by using dichloromethane, washing is conducted by using n-hexane, and drying is conducted, thereby obtaining the modified polycarbonate resin; (4) 10 parts by weight of the modified polycarbonate resin is added to 81.99 parts by weight of tetrahydrofuran solvent, stirred and dispersed, 8 parts of 4-(2,2-diphenylvinyl)-N,N-di-p-tolyl aniline and 0.01 part of silicone oil are added and stirred to obtain a modified polycarbonate coating for a photosensitive drum.

[0017] Example 2 (1) 1 g of 3,5-dihydroxybenzaldehyde and 1.6 g of aminopropyl triethoxysilane are added to an ethanol solution, refluxed for 7 h under the protection of argon, dried after the reaction is completed, and a phenolic hydroxyl silane is obtained; (2) 0.1 g of graphene oxide and 0.6 g of 66.7% acetic acid aqueous solution are added to a tetrahydrofuran solution, stirred and dispersed, 1.2 g of the phenolic hydroxyl silane is added at 75°C, refluxed for 20 h, washed with deionized water after the reaction is completed, and dried to obtain a phenolic hydroxyl hyperbranched polysilane grafted graphene oxide; (3) 10 g of diphenyl carbonate, 12 g of bisphenol A, 0.0014 g of lithium acetate, and 0.3 g of the phenolic hydroxyl hyperbranched polysilane grafted graphene oxide are added to a flask, nitrogen is introduced, reacted at 200°C for 5 h, cooled to room temperature after the reaction is completed, dissolved with dichloromethane, washed with n-hexane, and dried to obtain a modified polycarbonate resin; (4) 13 parts by weight of the modified polycarbonate resin is added to 77.96 parts by weight of tetrahydrofuran solvent, stirred and dispersed, 9 parts of 4-(2,2-diphenylvinyl)-N,N-di-p-tolyl aniline and 0.04 parts of silicone oil are added and stirred to obtain a modified polycarbonate coating for a photosensitive drum.

[0018] Example 3 (1) 1 g of 3,5-dihydroxybenzaldehyde and 1.8 g of aminopropyl triethoxysilane are added to an ethanol solution, refluxed for 5 h under the protection of argon, dried after the reaction is completed, and a phenolic hydroxyl silane is obtained; (2) 0.1 g of graphene oxide and 0.6 g of 66.7% acetic acid aqueous solution are added to a tetrahydrofuran solution, stirred and dispersed, 1.5 g of the phenolic hydroxyl silane is added at 70°C, refluxed for 24 h, washed with deionized water after the reaction is completed, and dried to obtain a phenolic hydroxyl hyperbranched polysilane grafted graphene oxide; (3) 10 g of diphenyl carbonate, 11 g of bisphenol A, 0.0015 g of lithium acetate, and 0.5 g of the phenolic hydroxyl hyperbranched polysilane grafted graphene oxide are added to a flask, nitrogen is introduced, reacted at 200°C for 4 h, cooled to room temperature after the reaction is completed, dissolved with dichloromethane, washed with n-hexane, and dried to obtain a modified polycarbonate resin; (4) Add 15 parts by weight of modified polycarbonate resin to 74.995 parts by weight of tetrahydrofuran solvent, stir and disperse, then add 10 parts of 4-(2,2-diphenylvinyl)-N,N-di-p-tolylaniline and 0.05 parts of silicone oil, stir and mix evenly to obtain a modified polycarbonate coating for photosensitive drums.

[0019] Comparative Example 1 The difference between this comparative example and Example 1 is that in step (4), N,N'-diphenyl-N,N'-bis(4-methylphenyl)-4,4'-diphenylenediamine is used instead of 4-(2,2-diphenylvinyl)-N,N-di-p-tolylaniline.

[0020] Comparative Example 2 The difference between this comparative example and Example 1 is that in step (4), 3,3'-di[p-tolyl]amino]biphenyl is used instead of 4-(2,2-diphenylvinyl)-N,N-di-p-tolylaniline.

[0021] Comparative Example 3 The difference between this comparative example and Example 1 is that in step (4), polycarbonate PCZ400 is used instead of modified polycarbonate resin.

[0022] The coating was applied to a 30*357cm long aluminum tube. The resulting photosensitive drum was cured at 110°C for 2 hours and then stored in a room with a temperature of 20±2°C and a humidity of 50±10% in the dark for 24 hours. A PDT-2000 electrical performance tester was used with a charging voltage of 6.9kV and a pressure of 800±10v, with VO being the original charging potential. 0.12uJ / cm 2 , 0.3uj / cm 2 , 0.6uj / cm 2 Three exposure energies are used to measure the residual potential VL value of the photosensitive drum.

[0023] Table 1:

[0024] Refer to the testing standard for base gray in GB / T 10073-2021 and use a whiteness meter for testing. The lower the test value of the whiteness meter, the higher the base gray level of the printed surface. Level 0 is the best and level 2 is poor.

[0025] Table 2:

[0026] As shown in Table 1 and Table 2, the modified polycarbonate coating prepared by the application has good charge transmission effect when applied in a photosensitive drum, and the excellent charge transmission effect and the improvement of the wear resistance of the coating can improve the print surface ground ash grade, and solve the problem of ground ash caused by long time charging and discharging in the prior art. The greater the V0 change value in Table 2, the weaker the surface voltage maintenance ability after the printing test, and the more serious the printing ground ash. Therefore, the modified polycarbonate coating prepared by the application has a wide application prospect in the photosensitive drum.

[0027] The above describes the embodiments of the application, but the application is not limited to the above specific embodiments, and the above specific embodiments are only illustrative but not restrictive, and those skilled in the art can make many forms without departing from the purpose of the application and the scope protected by the claims under the inspiration of the application, which all belong to the protection of the application.

Claims

1. A modified polycarbonate coating for a photosensitive drum, characterized in that: The modified polycarbonate coating for the photosensitive drum comprises the following raw materials by weight: 74.95-81.99 parts by weight of tetrahydrofuran solvent, 10-15 parts by weight of modified polycarbonate resin, 8-10 parts of charge transport material, and 0.01-0.05 parts of silicone oil; The preparation method of the modified polycarbonate coating for the photosensitive drum comprises the following steps: The modified polycarbonate resin is added to a tetrahydrofuran solvent, stirred and dispersed, and then a charge transport material and silicone oil are added thereto, and stirred and mixed uniformly to obtain a modified polycarbonate coating for a photosensitive drum; The charge transport material is 4-(2,2-diphenylvinyl)-N,N-di-p-tolylaniline; The preparation method of the modified polycarbonate resin comprises the following steps: (1) Add 3,5-dihydroxybenzaldehyde and aminopropyltriethoxysilane to an ethanol solution, and carry out a reflux reaction under the protection of argon. After the reaction is completed, dry the solution to obtain phenolic hydroxysilane; (2) adding graphene oxide and acetic acid aqueous solution to tetrahydrofuran solution, stirring and dispersing, adding phenolic hydroxyl silane thereto at 70-75°C, reflux reaction for 20-24 hours, washing with deionized water after the reaction, and drying to obtain phenolic hydroxyl hyperbranched polysilane grafted graphene oxide; (3) Add diphenyl carbonate, bisphenol A, lithium acetate, and phenolic hydroxyl hyperbranched polysilane grafted graphene oxide into a flask, introduce nitrogen, and react at 200°C for 3-5 hours. After the reaction is completed, cool to room temperature, dissolve in dichloromethane, wash with n-hexane, and dry to obtain a modified polycarbonate resin.

2. The modified polycarbonate coating for photosensitive drum according to claim 1, characterized in that: In the above (1), the usage ratio of 3,5-dihydroxybenzaldehyde and aminopropyltriethoxysilane is 1 g:(1.6-1.8) g.

3. The modified polycarbonate coating for a photosensitive drum according to claim 1, wherein: In the above (1), the reflux reaction time is 5-8h.

4. The modified polycarbonate coating for photosensitive drum according to claim 1, wherein In the above (2), the usage ratio of graphene oxide and phenolic hydroxyl silane is 1 g: (10-15) g.

5. The modified polycarbonate coating for photosensitive drum according to claim 1, wherein: In (2), the mass fraction of the acetic acid aqueous solution is 66.7%.

6. The modified polycarbonate coating for photosensitive drum according to claim 1, characterized in that: In the above (3), the usage ratio of diphenyl carbonate, bisphenol A, lithium acetate, and phenolic hydroxyl hyperbranched polysilane grafted graphene oxide is 1g: (1-1.2)g: (0.00012-0.00015)g: (0.01-0.05)g.

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