A semi-conductive extruded silicone rubber for OA rollers, a method for preparing the same, and use thereof
By optimizing the component formulation and process, the prepared semi-conductive extruded silicone rubber solves the problems of unstable conductivity and insufficient wear resistance of traditional silicone rubber in laser printer developing rollers, realizing a high-performance developing roller material suitable for laser printer developing rollers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XINAN TIANYU SILICONE CO LTD
- Filing Date
- 2026-04-09
- Publication Date
- 2026-06-09
AI Technical Summary
Traditional silicone rubber materials have unstable conductivity in the developing rollers of laser printers, which can easily cause printing quality problems. In addition, their wear resistance and fatigue resistance are insufficient, which cannot meet the requirements of high-speed and high-precision printing.
A semi-conductive extruded silicone rubber is prepared by using methyl vinyl silicone rubber as the main body, combined with fumed silica, structure control agent, powder treatment agent, release agent, stabilizing powder, heat resistant agent and conductive agent in an optimized formula, and through mixing and extrusion molding process, to form a conductive network to improve the overall performance of the material.
The developing roller material has stable conductivity, low noise, small permanent deformation, and good resilience, making it suitable for high-speed, high-volume printing, extending its service life, and exhibiting excellent overall performance.
Smart Images
Figure CN122168028A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of silicone rubber technology, and more specifically, to a semi-conductive extruded silicone rubber for OA rollers, its preparation method, and its application. Background Technology
[0002] In modern office automation (OA) equipment, laser printers, as core output tools, have printing performance closely related to the material properties of their key components. The developing roller, as one of the key components of a laser printer, plays a crucial role in uniformly transferring toner to the photosensitive drum. Its performance directly determines the clarity and uniformity of the printed image, as well as the overall reliability and lifespan of the equipment. Traditional developing rollers are mostly made of ordinary silicone rubber. While this material possesses certain flexibility and heat resistance, it gradually reveals several limitations during long-term operation: its conductivity is often insufficient or unstable, easily causing problems such as uneven background graying, inconsistent shades, or blurred lines in the printed parts; its wear resistance and fatigue resistance are weak, reducing the uniformity of toner coating on the roller; and its insufficient material resilience exacerbates vibration and friction during operation, not only generating significant operating noise and affecting the office environment, but also accelerating fatigue damage to the roller and surrounding components, shortening the lifespan of the developing roller and even the entire machine. To improve conductivity, conductive fillers have been introduced to prepare conductive silicone rubber. While these materials offer some improvement in the adjustability of surface resistivity, they still exhibit significant drawbacks in practical applications: conductivity is prone to drift with temperature, humidity, and long-term stress, resulting in insufficient stability and durability. Furthermore, uneven filler dispersion or poor compatibility with the matrix often leads to decreased mechanical properties, difficulty in maintaining resilience, and significant residual deformation after long-term compression, failing to meet the dynamic contact stability requirements of high-speed, high-volume printing scenarios. As laser printers evolve towards higher speeds, higher precision, longer lifespans, and lower noise levels, traditional silicone rubber materials are increasingly unable to meet these performance standards.
[0003] In view of this, the present invention is proposed. Summary of the Invention
[0004] The purpose of this invention is to provide a semi-conductive extruded silicone rubber for OA rollers, its preparation method and application, which can meet the performance requirements of laser printer accessories. The product has stable and durable conductivity, low noise, clear printing, low permanent deformation, good resilience and long service life. It is suitable for extrusion molding, with high efficiency and low cost.
[0005] This invention is implemented as follows: In a first aspect, the present invention provides a semi-conductive extruded silicone rubber for OA rollers, comprising the following components by mass parts: 120 parts of methyl vinyl silicone rubber, 10-25 parts of fumed silica, 1-5 parts of structure control agent, 1-5 parts of powder treatment agent, 0.05-0.5 parts of release agent, 21.5-80 parts of stabilizing powder, 0.2-3 parts of heat resistant agent, and 5-20 parts of conductive agent.
[0006] In some preferred embodiments, the methyl vinyl silicone rubber has a vinyl content of 0.04-0.25% and a weight-average molecular weight of 560,000-760,000.
[0007] In some preferred embodiments, the specific surface area of the fumed silica is 150-250 m². 2 / g.
[0008] In some preferred embodiments, the structure control agent includes at least one selected from hydroxyl silicone oil, vinyl hydroxyl silicone oil, methoxyl silicone oil, dimethyldimethoxysilane, and hexamethyldisilazane, as well as distilled water; the hydroxyl content of the hydroxyl silicone oil is 7-10%; the vinyl hydroxyl content of the vinyl silicone oil is 4-6%, and the vinyl content is 6-8%; the viscosity of the methoxyl silicone oil is 2.0-10.0 mm. 2 / s; the purity of the dimethyldimethoxysilane is not less than 98%; the purity of the hexamethyldisilazane is not less than 99%.
[0009] In some preferred embodiments, the release agent is at least one selected from zinc stearate, calcium stearate, barium stearate, magnesium stearate, zinc laurate, magnesium laurate, palmitic acid, oleic acid, lauric acid, and stearic acid.
[0010] In some preferred embodiments, the powder treatment agent is at least one of vinyltriethoxysilane, vinyl silicone oil, and methyl silicone oil; the purity of the vinyltriethoxysilane is ≥98%; the viscosity of the vinyl silicone oil is 300-10000 mPa·s, and the vinyl content is 0.15-3%; the kinematic viscosity of the methyl silicone oil is 800-1200 cs.
[0011] In some preferred embodiments, the stable powder is at least one of high specific surface area silica powder and wollastonite powder; the particle size of the high specific surface area silica powder is 1-2µm; and the particle size of the wollastonite powder is 4-60µm.
[0012] In some preferred embodiments, the heat-resistant agent is at least one selected from cerium oxide, cerium acetate, cerium oxalate, cerium sulfate, cerium nitrate, and cerium carbonate, with a purity of not less than 95%; the conductive agent is selected with a specific surface area of 50-1500 m². 2 / g of conductive carbon black.
[0013] Secondly, the present invention provides a method for preparing semiconductive extruded silicone rubber for OA rollers, comprising the following steps: Methyl vinyl silicone rubber raw material, structure control agent, powder treatment agent and release agent are put into a mixing equipment for premixing, and fumed silica is added in batches. The mixture is then continued to be mixed until uniform to obtain a mixture. After the mixture is placed at room temperature for 5 to 30 hours, the temperature is raised to 160 to 180°C and then re-kneaded under vacuum for 2 to 5 hours. After cooling, the masterbatch is obtained. Sterilize the stabilizing powder, heat resistant agent, conductive agent and masterbatch for 1-2 hours, extrude and filter out impurities, and shape to obtain silicone rubber.
[0014] Thirdly, this invention proposes the application of a semi-conductive extruded silicone rubber for OA rollers in the developing roller of a laser printer.
[0015] The present invention has the following beneficial effects: This invention significantly improves the overall performance of a material by using methyl vinyl silicone rubber as the main component and optimizing the formulation ratios of fumed silica, structure control agents, powder treatment agents, release agents, stabilizing powders, heat resistant agents, and conductive agents. In terms of mechanical properties, it exhibits excellent tensile strength, tear strength, and resilience, while also displaying low compression set and high durability. Regarding processability, extrusion molding is smooth and efficient, producing a smooth, dense product without porosity defects, and the rubber rollers exhibit good processability and high precision. In terms of electrical properties, it demonstrates stable and uniform conductivity, controllable resistance, and meets the requirements of semiconducting devices. During long-term use, the material exhibits good fatigue resistance and temperature resistance, effectively reducing operating noise and extending the service life of developing rollers and printers. Its excellent overall performance makes it a promising material for future applications. Attached Figure Description
[0016] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0017] Figure 1 This is a schematic diagram of the silicone rubber prepared according to an embodiment of the present invention; Figure 2 This is a schematic diagram of the silicone rubber tube prepared according to an embodiment of the present invention; Figure 3 This is a schematic diagram of the developing roller prepared according to an embodiment of the present invention; Figure 4 This is a diagram illustrating the operation of the printer. Detailed Implementation
[0018] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.
[0019] The following provides a detailed description of a semi-conductive extruded silicone rubber for OA rollers, its preparation method, and its application.
[0020] In a first aspect, the present invention provides a semi-conductive extruded silicone rubber for OA rollers, comprising the following components by mass parts: 120 parts of methyl vinyl silicone rubber, 10-25 parts of fumed silica, 1-5 parts of structure control agent, 1-5 parts of powder treatment agent, 0.05-0.5 parts of release agent, 21.5-80 parts of stabilizing powder, 0.2-3 parts of heat resistant agent, and 5-20 parts of conductive agent.
[0021] In some preferred embodiments, the methyl vinyl silicone rubber has a vinyl content of 0.04-0.25% and a weight-average molecular weight of 560,000-760,000. The raw methyl vinyl silicone rubber serves as the crosslinking host, and the crosslinking density design provides important properties such as tensile strength, elongation, tear strength, resilience, and compression set. This range of vinyl content helps improve the thermal stability and aging resistance of the silicone rubber, facilitates the formation of a uniform crosslinking network during vulcanization, thereby improving the overall performance of the product and also enhancing its processability.
[0022] In some preferred embodiments, the fumed silica is used as a reinforcing filler to further improve mechanical properties.
[0023] In some preferred embodiments, the structuring control agent includes at least one of hydroxyl silicone oil, vinyl hydroxyl silicone oil, methoxy silicone oil, dimethyl dimethoxysilane, and hexamethyldisilazane, as well as distilled water; The hydroxyl silicone oil contains 7-10% hydroxyl groups; the vinyl hydroxyl silicone oil contains 4-6% hydroxyl groups and 6-8% vinyl groups; the dimethyldimethoxysilane has a purity of not less than 98%; and the methoxysilane has a viscosity of 2.0-10.0 mm. 2 / s; the purity of the hexamethyldisilazane is not less than 99%.
[0024] Furthermore, adding hydroxyl silicone oil, hexamethyldisilazane and other structure control agents improves the anti-structural properties and processability of silicone rubber, making the silicone rubber smooth and free of appearance defects such as pores and particles during extrusion molding.
[0025] In some preferred embodiments, the release agent is at least one selected from zinc stearate, calcium stearate, barium stearate, magnesium stearate, zinc laurate, magnesium laurate, palmitic acid, oleic acid, lauric acid, and stearic acid; the powder treatment agent is at least one selected from vinyltriethoxysilane, vinyl silicone oil, and methyl silicone oil. The vinyltriethoxysilane has a purity of ≥98%; the vinyl silicone oil has a viscosity of 300-10000 mPa·s and a vinyl content of 0.15-3%; and the methyl silicone oil has a kinematic viscosity of 800-1200 cs.
[0026] Furthermore, adding release agents and powder treatment agents improves the fluidity of silicone rubber, making it easier to process and resulting in molded products with a smooth appearance free of defects such as pores and particles.
[0027] In some preferred embodiments, the stable powder is at least one of high specific surface area silica micro powder and wollastonite powder; The high specific surface area silica powder has a particle size of 1-2µm; the wollastonite powder has a particle size of 4-60µm.
[0028] Stabilizing powders can increase the density of silicone rubber, stabilize the pressure during silicone rubber extrusion molding, increase self-venting capacity, further improve the gloss of the extruded appearance of silicone rubber, and prevent the formation of pores; at the same time, they can increase the dispersion uniformity of functional additives such as heat-resistant agents and conductive agents, and improve the overall performance and electrical conductivity stability.
[0029] In some preferred embodiments, the heat-resistant agent is at least one of cerium oxide, cerium acetate, cerium oxalate, cerium sulfate, cerium nitrate, and cerium carbonate, with a purity of not less than 95%; wherein, the heat-resistant agent is also a high-resilience additive, which improves the temperature resistance of silicone rubber and the treatment of decomposition products after vulcanization, increases the deformation resistance of silicone rubber, reduces compression set, and improves resilience.
[0030] Furthermore, when a certain amount of conductive agent is added to the above matrix, they interconnect within the matrix to form a conductive network, transforming the silicone rubber from an insulating material into a semiconductor material with specific conductivity, providing the stable resistance required for the application scenario; the conductive agent is selected with a specific surface area of 50-1500 m². 2 / g of conductive carbon black.
[0031] In an optional embodiment, a semi-conductive extruded silicone rubber for OA rollers comprises the following components by weight: 100 parts methyl vinyl silicone rubber, 10-25 parts fumed silica, 0.2-2 parts hydroxyl silicone oil, 0.2-1 parts vinyl hydroxyl silicone oil, 0.2-2 parts methoxy silicone oil, 0.3-1 parts dimethyldimethoxysilane, 0.5-3 parts hexamethyldisilazane, 0.2-2 parts vinyl silicone oil, 0.1-2 parts methyl silicone oil, 0.05-0.3 parts vinyltriethoxysilane, 0.05-0.5 parts release agent, 1-10 parts high specific surface area silica powder, 0.5-10 parts wollastonite powder, 0.2-3 parts heat resistant agent, and 5-20 parts conductive carbon black, as well as an appropriate amount of distilled water.
[0032] Secondly, the present invention provides a method for preparing semiconductive extruded silicone rubber for OA rollers, comprising the following steps: Methyl vinyl silicone rubber raw rubber, vinyl hydroxy silicone oil, hydroxy silicone oil, vinyl silicone oil, hexamethyldisilazane, dimethyldimethoxysilane, vinyltriethoxysilane and release agent are put into a mixing equipment for premixing. Fumed silica is added in batches and the mixture is continued to be mixed until uniform to obtain a mixture. After the mixture is placed at room temperature for 5 to 30 hours, the temperature is raised to 160 to 180°C and then re-kneaded under vacuum for 2 to 5 hours. After cooling, the masterbatch is obtained. The stabilizing powder, heat resistant agent, conductive agent, and masterbatch are mixed and stirred for 1-2 hours. Impurities are then filtered out by extrusion, and the mixture is shaped to obtain silicone rubber. Figure 1 As shown.
[0033] Thirdly, this invention proposes the application of a semi-conductive extruded silicone rubber for OA rollers in the developing roller of a laser printer.
[0034] The silicone rubber prepared by the above method is extruded to obtain a silicone rubber tube, such as... Figure 2 As shown, the silicone rubber tube is then threaded onto the roller shaft and processed to obtain the developing roller, as shown. Figure 3 As shown, finally install the developing roller into the printer. A schematic diagram of the printer's operation is shown below. Figure 4 As shown.
[0035] The features and performance of the present invention will be further described in detail below with reference to embodiments.
[0036] Example 1 This embodiment provides a semi-conductive extruded silicone rubber for OA (over-the-counter) rollers, comprising the following components by weight: 120 parts of methyl vinyl silicone rubber, wherein the vinyl content is 0.08% and the weight average molecular weight is 680,000; 16 parts of fumed silica, with a specific surface area of 200 m². 2 / g; 0.2 parts hydroxyl silicone oil with a hydroxyl content of 9%; 0.2 parts vinyl hydroxyl silicone oil with a hydroxyl content of 5% and a vinyl content of 6.5%; 0.2 parts methoxy silicone oil with a viscosity of 3.0 mm. 2 / s; 0.5 parts dimethyldimethoxysilane; 1.1 parts hexamethyldisilazane; 0.3 parts distilled water; 0.5 parts vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 1.13%; 2 parts methyl silicone oil with a kinematic viscosity of 900 cs; 0.1 parts vinyltriethoxysilane; 0.2 parts zinc stearate; 45 parts high specific surface area silica powder; 0.5 parts cerium acetate; conductive agent including 9 parts with a specific surface area of 100 m² 2 / g of conductive carbon black and 3.5 parts of a specific surface area of 1300m² 2 / g of conductive carbon black.
[0037] Its preparation method includes the following steps: S1, methyl vinyl silicone rubber raw rubber, vinyl hydroxy silicone oil, hydroxy silicone oil, vinyl silicone oil, hexamethyldisilazane, dimethyldimethoxysilane, vinyltriethoxysilane, and release agent are put into a mixing equipment for premixing. Fumed silica is added in batches and the mixture is continued to be mixed until uniform to obtain a mixture. S2. After the mixture is placed at room temperature for 20 hours, the temperature is raised to 165°C and re-kneaded under vacuum for 3 hours, then cooled to obtain the masterbatch. S3. Mix the stabilizing powder, heat resistant agent, conductive agent and masterbatch for 1.5 hours, extrude and filter impurities, and shape to obtain silicone rubber.
[0038] Example 2 This embodiment provides a semi-conductive extruded silicone rubber for OA rollers, and the steps are the same as in Embodiment 1, except that the silicone rubber includes the following components: 120 parts of methyl vinyl silicone rubber, wherein the vinyl content is 0.08% and the weight average molecular weight is 680,000; 15 parts of fumed silica, with a specific surface area of 200 m². 2 / g; 1 part hydroxyl silicone oil with a hydroxyl content of 9%; 0.2 parts vinyl hydroxyl silicone oil with a hydroxyl content of 5% and a vinyl content of 6.5%; 0.2 parts methoxy silicone oil with a viscosity of 3.0 mm. 2 / s; 0.5 parts dimethyldimethoxysilane; 1.1 parts hexamethyldisilazane; 0.3 parts distilled water; 0.5 parts vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 1.13%; 2 parts methyl silicone oil with a kinematic viscosity of 900 cs; 0.1 parts vinyltriethoxysilane; 0.2 parts zinc stearate; 40 parts high specific surface area silica powder; 0.5 parts cerium acetate; conductive agent including 19 parts with a specific surface area of 100 m² 2 / g of conductive carbon black and 1 part of a specific surface area of 1300m 2 / g of conductive carbon black.
[0039] Example 3 This embodiment provides a semi-conductive extruded silicone rubber for OA rollers, and the steps are the same as in Embodiment 1, except that the silicone rubber includes the following components: 120 parts of methyl vinyl silicone rubber, wherein the vinyl content is 0.23% and the weight average molecular weight is 680,000; 18 parts of fumed silica, with a specific surface area of 200 m². 2 / g; 1.5 parts hydroxyl silicone oil with a hydroxyl content of 9%; 0.2 parts vinyl hydroxyl silicone oil with a hydroxyl content of 5% and a vinyl content of 6.5%; 0.2 parts methoxy silicone oil with a viscosity of 3.0 mm. 2 / s Dimethyldimethoxysilane 0.5 parts; hexamethyldisilazane 1.1 parts; distilled water 0.3 parts; vinyl silicone oil 0.5 parts, with a viscosity of 500 mPa·s and a vinyl content of 1.13%; methyl silicone oil 2 parts, with a kinematic viscosity of 900 cs; vinyltriethoxysilane 0.1 parts; zinc stearate 0.2 parts; high specific surface area silica powder 40 parts; cerium acetate 0.5 parts; conductive agent including 4 parts with a specific surface area of 850 m² 2 / g of conductive carbon black and 3 parts of a specific surface area of 1300m² 2 / g of conductive carbon black.
[0040] Example 4 This embodiment provides a semi-conductive extruded silicone rubber for OA rollers, and the steps are the same as in Embodiment 1, except that the silicone rubber includes the following components: 120 parts of methyl vinyl silicone rubber, wherein the vinyl content is 0.23% and the weight average molecular weight is 680,000; 18 parts of fumed silica, with a specific surface area of 150 m². 2 / g; 1.5 parts hydroxyl silicone oil with a hydroxyl content of 9%; 0.2 parts vinyl hydroxyl silicone oil with a hydroxyl content of 5% and a vinyl content of 6.5%; 0.2 parts methoxy silicone oil with a viscosity of 3.0 mm. 2 / s; 0.5 parts dimethyldimethoxysilane; 1.1 parts hexamethyldisilazane; 0.3 parts distilled water; 0.5 parts vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 1.13%; 2 parts methyl silicone oil with a kinematic viscosity of 900 cs; 0.1 parts vinyltriethoxysilane; 0.2 parts zinc stearate; 45 parts high specific surface area silica powder; 0.5 parts cerium acetate; conductive agent including 4 parts with a specific surface area of 850 m² 2 / g of conductive carbon black and 3 parts of a specific surface area of 1300m² 2 / g of conductive carbon black.
[0041] Example 5 This embodiment provides a semi-conductive extruded silicone rubber for OA rollers, and the steps are the same as in Embodiment 1, except that the silicone rubber includes the following components: 120 parts of methyl vinyl silicone rubber, wherein the vinyl content is 0.08% and the weight average molecular weight is 680,000; 16 parts of fumed silica, with a specific surface area of 200 m². 2 / g; 0.2 parts hydroxyl silicone oil with a hydroxyl content of 9%; 0.2 parts vinyl hydroxyl silicone oil with a hydroxyl content of 5% and a vinyl content of 6.5%; 0.2 parts methoxy silicone oil with a viscosity of 3.0 mm. 2 / s; 0.5 parts dimethyldimethoxysilane; 1.1 parts hexamethyldisilazane; 0.3 parts distilled water; 0.5 parts vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 1.13%; 2 parts methyl silicone oil with a kinematic viscosity of 900 cs; 0.1 parts vinyltriethoxysilane; 0.2 parts zinc stearate; 45 parts wollastonite powder; 0.5 parts cerium acetate; conductive agent including 9 parts with a specific surface area of 100 m² 2 / g of conductive carbon black and 3.5 parts of a specific surface area of 1300m² 2 / g of conductive carbon black.
[0042] Example 6 This embodiment provides a semi-conductive extruded silicone rubber for OA rollers, and the steps are the same as in Embodiment 1, except that the silicone rubber includes the following components: 120 parts of methyl vinyl silicone rubber, wherein the vinyl content is 0.08% and the weight average molecular weight is 680,000; 15 parts of fumed silica, with a specific surface area of 250 m². 2 / g; 1.2 parts hydroxyl silicone oil with a hydroxyl content of 9%; 0.2 parts vinyl hydroxyl silicone oil with a hydroxyl content of 5% and a vinyl content of 6.5%; 0.2 parts methoxy silicone oil with a viscosity of 3.0 mm. 2 / s; 0.5 parts dimethyldimethoxysilane; 1.1 parts hexamethyldisilazane; 0.3 parts distilled water; 0.5 parts vinyl silicone oil with a viscosity of 500 mPa·s and a vinyl content of 1.13%; 4.5 parts methyl silicone oil with a kinematic viscosity of 900 cs; 0.1 parts vinyltriethoxysilane; 0.2 parts zinc stearate; 45 parts high specific surface area silica powder; 0.5 parts cerium acetate; conductive agent including 9 parts with a specific surface area of 100 m² 2 / g of conductive carbon black and 3.5 parts of a specific surface area of 1300m² 2 / g of conductive carbon black.
[0043] Comparative Example 1 This comparative example provides a semi-conductive extruded silicone rubber for OA rollers, and the steps are the same as in Example 1, except that no heat resistant agent is added to the silicone rubber.
[0044] Comparative Example 2 This comparative example provides a semi-conductive extruded silicone rubber for OA rollers, and the steps are the same as in Example 1, except that the conductive agent in the silicone rubber includes 3 parts with a specific surface area of 100m². 2 / g of conductive carbon black and 2 parts of a specific surface area of 1300m² 2 / g of conductive carbon black.
[0045] Comparative Example 3 This comparative example provides a semi-conductive extruded silicone rubber for OA rollers, with the same steps as in Example 1, except that the silicone rubber contains 16 parts of fumed silica, and its specific surface area is 300 m². 2 / g.
[0046] Comparative Example 4 This comparative example provides a semi-conductive extruded silicone rubber for OA rollers, and the steps are the same as in Example 1, except that no stabilizing powder is added to the silicone rubber.
[0047] Experimental Example 1 The silicone rubbers prepared in Examples 1-6 and Comparative Examples 1-4 were tested for physical and electrical properties. The testing methods are shown in Table 1, and the results are shown in Table 2.
[0048] Table 1. Performance Testing Methods
[0049] Table 2. Performance Test Results
[0050] Based on the above test results, it can be seen that in terms of physical properties, the plasticity, hardness, density, tensile strength, elongation, tear strength, resilience, and compression set of Examples 1-6 basically meet the standard requirements in Table 1, indicating that the formulation design of each example maintains the good mechanical properties and resilience of silicone rubber. Among them, Examples 1, 4, and 5 show excellent performance in compression set (≤1.2%), demonstrating good deformation recovery ability; while Comparative Example 1 (without heat resistant agent) has a compression set as high as 6.2%, significantly higher than the standard requirement. Excessive compression set value will cause significant deformation of the rubber roller in actual operation, which will lead to unstable printing pressure and shorten service life. Therefore, the rubber roller with excessive deformation cannot meet the requirements of actual application. Thus, the lack of heat resistant agent leads to increased permanent deformation of the material under hot compression conditions and decreased durability. In addition, the plasticity of Comparative Example 3 (using fumed silica with a specific surface area of 300 m² / g) was too high (195), which was due to the increased specific surface area of the filler leading to a decrease in the processing fluidity of the rubber compound and a lower than required resilience. The plasticity of Comparative Example 4 (without added stabilizing powder) was too low (125), and the density decreased. Insufficient venting during the extrusion process affected the compactness and performance stability of the material, and the resilience decreased.
[0051] In terms of electrical properties, volume resistivity and overall roller resistance are key indicators for evaluating the performance of semiconductive rubber rollers. Examples 1-6 all exhibited low volume resistivity and relatively low overall roller resistance, demonstrating good conductivity, which is closely related to the proportion and type of conductive carbon black used. In contrast, Comparative Example 2, due to a significantly insufficient amount of conductive agent, experienced a sharp increase in volume resistivity to 2510 Ω·cm and a roller resistance as high as 7.9 × 10⁻⁶. 6 Ω, the conductivity is severely reduced and cannot meet the requirements; Comparative Example 4, without the addition of stabilizing powder, has a significantly increased resistivity, indicating that the lack of stabilizing powder will cause defects such as bubbles inside the silicone rubber to directly block the formation of conductive pathways.
[0052] In summary, the performance of semiconductive silicone rubber is highly dependent on the synergy and balance among its components. The absence or improper proportioning of any key component can have a significant negative impact on electrical properties and long-term durability, thereby affecting the actual application of the rubber roller.
[0053] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.
Claims
1. A semi-conductive extruded silicone rubber for OA (off-gas) rollers, characterized in that, The product comprises the following components by weight: 120 parts methyl vinyl silicone rubber, 10-25 parts fumed silica, 1-5 parts structure control agent, 1-5 parts powder treatment agent, 0.05-0.5 parts release agent, 21.5-80 parts stabilizing powder, 0.2-3 parts heat resistant agent, and 5-20 parts conductive agent.
2. The semi-conductive extruded silicone rubber for OA rollers according to claim 1, characterized in that, The methyl vinyl silicone rubber has a vinyl content of 0.04-0.25% and a weight-average molecular weight of 560,000-760,000.
3. The semi-conductive extruded silicone rubber for OA rollers according to claim 1, characterized in that, The specific surface area of the fumed silica is 150-250 m². 2 / g.
4. The semi-conductive extruded silicone rubber for OA rollers according to claim 1, characterized in that, The structure control agent comprises at least one selected from hydroxyl silicone oil, vinyl hydroxyl silicone oil, methoxyl silicone oil, dimethyldimethoxysilane, and hexamethyldisilazane, as well as distilled water; the hydroxyl content in the hydroxyl silicone oil is 7-10%; the vinyl hydroxyl content in the vinyl hydroxyl silicone oil is 4-6%, and the vinyl content is 6-8%; the viscosity of the methoxyl silicone oil is 2.0-10.0 mm. 2 / s; the purity of the dimethyldimethoxysilane is not less than 98%; the purity of the hexamethyldisilazane is not less than 99%.
5. The semi-conductive extruded silicone rubber for OA rollers according to claim 1, characterized in that, The release agent is at least one of zinc stearate, calcium stearate, barium stearate, magnesium stearate, zinc laurate, magnesium laurate, palmitic acid, oleic acid, lauric acid, and stearic acid.
6. The semi-conductive extruded silicone rubber for OA rollers according to claim 1, characterized in that, The powder treatment agent is at least one of vinyltriethoxysilane, vinyl silicone oil, and methyl silicone oil; the purity of the vinyltriethoxysilane is ≥98%; the viscosity of the vinyl silicone oil is 300-10000 mPa·s, and the vinyl content is 0.15-3%; the kinematic viscosity of the methyl silicone oil is 800-1200 cs.
7. The semi-conductive extruded silicone rubber for OA rollers according to claim 1, characterized in that, The stable powder is at least one of high specific surface area silica powder and wollastonite powder; the particle size of the high specific surface area silica powder is 1-2µm; the particle size of the wollastonite powder is 4-60µm.
8. The semi-conductive extruded silicone rubber for OA rollers according to claim 1, characterized in that, The heat-resistant agent is at least one selected from cerium oxide, cerium acetate, cerium oxalate, cerium sulfate, cerium nitrate, and cerium carbonate, with a purity of not less than 95%; the conductive agent is selected with a specific surface area of 50-1500 m². 2 / g of conductive carbon black.
9. A method for preparing semi-conductive extruded silicone rubber for OA rollers as described in any one of claims 1-8, characterized in that, Includes the following steps: Methyl vinyl silicone rubber raw material, structure control agent, powder treatment agent and release agent are put into a mixing equipment for premixing, and fumed silica is added in batches. The mixture is then continued to be mixed until homogeneous to obtain a mixture. After the mixture is placed at room temperature for 5 to 30 hours, the temperature is raised to 160 to 180°C and then re-kneaded under vacuum for 2 to 5 hours. After cooling, the masterbatch is obtained. Sterilize the stabilizing powder, heat resistant agent, conductive agent and masterbatch for 1-2 hours, extrude and filter out impurities, and shape to obtain silicone rubber.
10. The application of a semiconductive extruded silicone rubber for OA rollers as described in any one of claims 1-8 in the developing roller of a laser printer.