Rubber sealing strip as well as preparation method and application thereof
By performing surface modification treatment and specific formulation design on fly ash, the problems of poor dispersibility and compatibility of fly ash in rubber matrix have been solved, and high-performance fly ash automotive rubber sealing strips have been developed, which reduce costs and improve material performance, meeting the requirements of green and sustainable development.
Patent Information
- Application Number
- CN202511843846.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-12-09
- Publication Date
- 2026-01-09
AI Technical Summary
The poor interfacial compatibility between fly ash and rubber matrix in existing automotive sealing strip formulations leads to a decline in the mechanical properties of the material. Furthermore, traditional fillers are costly, prone to dust pollution, and highly dependent on petroleum resources, which does not meet the requirements of green and sustainable development.
By surface modification of fly ash using composite surface modifiers such as silane coupling agents, titanate coupling agents, and aluminate coupling agents, the dispersibility and compatibility of fly ash in the rubber matrix can be improved. Combined with specific formulation design, including raw materials such as EPDM rubber, carbon black, and plasticizers, the mixing and extrusion processes are optimized to ensure uniform distribution of each component.
It improves the ozone resistance, heat resistance, and aging resistance of fly ash automotive rubber sealing strips, reduces material costs, improves processing fluidity and surface smoothness, and solves the problem of poor dispersion and compatibility of fly ash in rubber matrix, which meets the requirements of green and sustainable development.
Smart Images
Figure SMS_1 
Figure SMS_2
Abstract
Description
Technical Field
[0001] This invention relates to the field of rubber products technology, specifically to a rubber sealing strip, its preparation method, and its application. Background Technology
[0002] Automotive sealing strips are important sealing components in automobiles, mainly used in doors, windows, trunks, engine compartments, and other areas, serving functions such as sealing, sound insulation, dust prevention, waterproofing, and shock absorption. With the development of the automotive industry, the performance requirements for sealing strips are becoming increasingly stringent, demanding not only excellent sealing performance but also superior weather resistance, aging resistance, low compression set, and environmental friendliness.
[0003] Currently, automotive sealing strips mainly use ethylene propylene diene monomer (EPDM) rubber as the matrix material, combined with fillers such as carbon black, calcium carbonate, and talc. However, traditional formulations have the following problems: traditional fillers such as carbon black are expensive and easily generate dust pollution during production; the aging resistance and compression set performance of sealing strips still have room for improvement; and traditional formulations are highly dependent on petroleum resources, which does not meet the requirements of green and sustainable development.
[0004] Fly ash is a major solid waste emitted by coal-fired power plants, with a huge annual emission volume. Its accumulation and disposal not only occupy a large amount of land resources but also may cause environmental pollution. How to achieve high-value resource utilization of fly ash has become a current research hotspot. Existing technologies have attempted to apply fly ash to rubber products, but due to the poor interfacial compatibility between fly ash and the rubber matrix, direct addition often leads to a decline in the mechanical properties of the material, limiting its application range. Therefore, this invention provides a rubber sealing strip, its preparation method, and its application. Summary of the Invention
[0005] The technical problem to be solved by this invention is to provide a rubber sealing strip, its preparation method, and its application. The aim is to solve the problem of poor dispersibility and compatibility of fly ash in a rubber matrix through specific surface modification techniques and formulation design, thereby developing a high-performance fly ash automotive rubber sealing strip.
[0006] The technical solution of the present invention to solve the above-mentioned technical problems is as follows: In a first aspect, a rubber sealing strip comprises the following raw materials in parts by weight: 80-100 parts of EPDM rubber, 100-140 parts of carbon black, 100-140 parts of modified fly ash, 70-100 parts of plasticizer, 5-8 parts of zinc oxide, 1-2 parts of stearic acid, 1-3 parts of flow aid, 1-2 parts of microcrystalline wax, 10-20 parts of hygroscopic agent, 1-2 parts of activator, 2-4 parts of accelerator, and 1-2 parts of vulcanizing agent.
[0007] The beneficial effects of this invention are as follows: Through specific surface modification technology and formulation design, the main chain of EPDM rubber is saturated, resulting in excellent ozone resistance, heat resistance, and aging resistance; carbon black provides basic reinforcement; modified fly ash exhibits good dispersibility and compatibility in the rubber matrix; plasticizers improve processing fluidity; zinc oxide promotes vulcanization; stearic acid acts as a lubricant and activator; flow aids improve processing fluidity; microcrystalline wax improves surface smoothness and prevents aging; hygroscopic agents prevent internal bubble formation; activators enhance vulcanization speed and performance and plasticize; and accelerators control the vulcanization speed. By synergistically combining raw materials, the problem of poor dispersibility and compatibility of fly ash in the rubber matrix is solved, resulting in a high-performance fly ash automotive rubber sealing strip.
[0008] Based on the above technical solution, the present invention can be further improved as follows.
[0009] Furthermore, the modified fly ash is obtained by the following method: heating and activating fly ash with a particle size D97≥1000 mesh, and then reacting the activated fly ash with a composite surface modifier to obtain modified fly ash; the composite surface modifier includes at least one of silane coupling agent (KH-550), titanate coupling agent (NDZ-201), and aluminate coupling agent (DL-411).
[0010] The beneficial effect of adopting the above-mentioned further solution is that coating the surface of fly ash with a modifier enables the fly ash and rubber to establish a stable chemical bond, thus ensuring that the product performance meets the standards.
[0011] Furthermore, the conditions for the heating activation are: a temperature of 110~130℃ and a time of 30 min~60 min in a high-speed mixer (mixing speed 500 rpm); The conditions for the modification reaction are: a temperature of 70~85℃ and a time of 30 min~45 min in a high-speed mixer (mixing speed 500 rpm).
[0012] Furthermore, the composite surface modifier includes a silane coupling agent, a titanate coupling agent, and an aluminate coupling agent; the mass ratio of the silane coupling agent, the titanate coupling agent, and the aluminate coupling agent is 1.8~2:0.8~1:0.8~1; the total concentration of the silane coupling agent, titanate coupling agent, and aluminate coupling agent in the composite surface modifier is 15~20%; and the composite surface modifier accounts for 3~5% of the mass of the fly ash.
[0013] For example, the modified fly ash is obtained through the following specific method: raw fly ash is sorted using an air classifier, with D97 ≥ 1000 mesh to obtain ultrafine fly ash; the ultrafine fly ash is placed in a high-speed mixer and activated at 110~130℃ for 30~60 min to remove surface adsorbed water; a composite surface modifier is prepared by mixing silane coupling agent, titanate coupling agent, and aluminate coupling agent in a mass ratio of 2:1:1, and diluted with an ethanol solvent to a concentration of 15%~20%; the composite surface modifier is slowly added to the high-speed mixer, with the modifier amount being 3~5% of the fly ash mass, and mixed at high speed at 70~85℃ for 30~45 min; the modified fly ash is dried at 80~100℃ until the moisture content is ≤0.5%, obtaining the modified fly ash product.
[0014] Furthermore, the plasticizer includes white oil; The vulcanizing agent includes sulfur; The flow aid includes RL-16; The desiccant includes Cao-80; The active agent includes PEG-4000; The accelerator includes DM / TMTD.
[0015] Furthermore, the rubber sealing strip also includes the following raw materials in parts by weight: 1 to 20 parts of recycled rubber.
[0016] Secondly, a method for preparing a rubber sealing strip includes the following steps: (1) Internal mixing: First, plasticize the EPDM rubber, then add some carbon black, modified fly ash and zinc oxide for mixing, and then add the remaining carbon black, plasticizer, flow aid, microcrystalline wax, hygroscopic agent, activator and stearic acid for mixing again to obtain a mixture; (2) Final grinding and vulcanization: an accelerator and a vulcanizing agent are added to the mixture for final grinding to obtain the precursor of automotive rubber sealing strip; (3) Extrusion molding: The rubber sealing strip precursor is extruded to obtain the automotive rubber sealing strip.
[0017] Furthermore, the plasticizing conditions in step (1) are: temperature of 110~120℃ and time of 0.5 min~4 min; The mixing conditions in step (1) are: temperature 110~120℃, time 3 min~5 min; The conditions for re-mixing in step (1) are: temperature of 120~130℃ and time of 5 min~10 min.
[0018] The beneficial effects of adopting the above-mentioned further scheme are: through thorough mixing, fly ash is fully dispersed in the material, avoiding agglomeration and preventing unstable material properties.
[0019] Furthermore, the specific method of final refining in step (2) is as follows: perform thin-passing 3 to 10 times and triangular wrapping 3 to 9 times. Among them, thin-passing refers to passing the rubber through the two rollers of the open mill with a very thin thickness. Triangular wrapping is an operation method that folds the rubber into triangular bundles to ensure uniform distribution of additives, improve the physical properties of rubber, increase production efficiency, facilitate storage, and ensure safe transportation.
[0020] For example, a method for preparing a rubber sealing strip includes the following specific steps: Step 1, Internal Mixing: First, put the EPDM rubber into an internal mixer and plasticize for 2 minutes. After softening, add 1 / 2 carbon black, modified fly ash, and zinc oxide, and mix for 3 to 5 minutes, controlling the temperature at 110 to 120℃. Then, add the remaining carbon black, microcrystalline wax, and other additives. The oil is added in three batches, with an interval of 10 to 30 seconds between each batch, and mix for 5 to 10 minutes, controlling the temperature at 120 to 130℃. Stearic acid is added in the final stage. Step 2, final refining and sulfur addition: On the open mill, add accelerator and sulfur, pass through the mill 3 to 10 times, and form triangular bundles 3 to 9 times to ensure that the components are evenly dispersed; Step 3, Extrusion molding: The final compound rubber is extruded into the shape of a sealing strip through a rubber extruder, and the extrusion temperature is controlled at 100℃.
[0021] Thirdly, the application of a rubber sealing strip, wherein the rubber sealing strip is used in the sealing strip of an automobile. Detailed Implementation
[0022] The principles and features of this invention are described below. The examples given are for illustrative purposes only and are not intended to limit the scope of the invention. Where specific techniques or conditions are not specified in the embodiments, they should be performed according to the techniques or conditions described in the literature in this field, or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased through legitimate channels.
[0023] Example 1 This embodiment provides a fly ash automotive rubber sealing strip, which comprises the following raw materials in parts by weight: 100 parts EPDM, 140 parts carbon black N550, 140 parts modified fly ash, 100 parts white oil, 5 parts zinc oxide, 1.5 parts stearic acid, 1.5 parts flow aid, 1 part microcrystalline wax, 15 parts hygroscopic agent, 1.5 parts activator, 3 parts accelerator, and 1.5 parts sulfur.
[0024] The preparation method of the fly ash automotive rubber sealing strip includes the following steps: Step 1, Fly Ash Pretreatment: The raw fly ash is sorted to D97=1250 mesh using an air classifier, placed in a high-speed mixer, and activated at 120℃ for 45 minutes. Then, a composite surface modifier (silane coupling agent KH-550, titanate coupling agent NDZ-201, and aluminate coupling agent DL-411 mixed at a mass ratio of 2:1:1 and diluted with ethanol to a concentration of 18%) is slowly added. The amount of modifier is 4% of the fly ash mass. The mixture is then high-speed mixed at 75℃ for 35 minutes. Finally, it is dried at 90℃ until the moisture content is ≤0.5%, resulting in modified fly ash.
[0025] Step 2, Internal mixing: First, put EPDM into an internal mixer and plasticize for 2 minutes. After softening, add 1 / 2 carbon black, modified fly ash, and zinc oxide, and mix for 3-5 minutes, with the temperature controlled at 110-120℃. Then, add the remaining carbon black, white oil, flow aid, microcrystalline wax, hygroscopic agent, activator, and stearic acid in sequence, with an interval of 20 seconds between each addition, and mix for 5-10 minutes, with the temperature controlled at 120-130℃. Step 3, final refining and sulfur addition: On the open mill, add accelerator and sulfur, pass through the mill 7 times, and make triangular wraps 6 times to ensure that the components are evenly dispersed. Step 4, Extrusion molding: The final compound rubber is extruded into the shape of a sealing strip through a rubber extruder, and the extrusion temperature is controlled at 100℃.
[0026] Example 2: (containing recycled rubber) To reduce costs and improve environmental friendliness, this embodiment uses a formulation containing reclaimed rubber. The rubber sealing strip comprises the following raw materials in parts by weight: 80 parts EPDM, 20 parts reclaimed rubber, 140 parts carbon black N550, 140 parts modified fly ash, 100 parts white oil, 5 parts zinc oxide, 1 part stearic acid, 1.5 parts flow aid (RL-16), 1 part microcrystalline wax (WAX), 12 parts hygroscopic agent (Cao-80), 1 part activator (PEG-4000), 2.5 parts accelerator (DM / TMTD), and 1.2 parts sulfur.
[0027] Preparation method: The preparation method is basically the same as in Example 1, except that: in step two, EPDM and reclaimed rubber are plasticized together; in step three, the vulcanization time is extended to ensure that the reclaimed rubber is fully vulcanized.
[0028] Example 3 This embodiment provides a fly ash automotive rubber sealing strip, which comprises the following raw materials in parts by weight: 80 parts EPDM, 100 parts carbon black, 100 parts modified fly ash, 70 parts white oil, 5 parts zinc oxide, 1 part stearic acid, 1 part flow aid, 1 part microcrystalline wax, 10 parts hygroscopic agent, 1 part activator, 2 parts accelerator, and 1 part sulfur.
[0029] The preparation method is the same as in Example 1.
[0030] Example 4 This embodiment provides a fly ash automotive rubber sealing strip, which comprises the following raw materials in parts by weight: 90 parts EPDM, 120 parts carbon black, 120 parts modified fly ash, 85 parts white oil, 6.5 parts zinc oxide, 1.5 parts stearic acid, 1.5 parts flow aid, 1.5 parts microcrystalline wax, 15 parts hygroscopic agent, 1.5 parts activator, 3 parts accelerator, and 1.5 parts sulfur.
[0031] The preparation method is the same as in Example 1.
[0032] Example 5 (Modified Fly Ash) This embodiment provides a fly ash automotive rubber sealing strip, which comprises the following raw materials in parts by weight: 100 parts EPDM, 140 parts carbon black N550, 140 parts modified fly ash, 100 parts white oil, 5 parts zinc oxide, 1.5 parts stearic acid, 1.5 parts flow aid (RL-16), 1 part microcrystalline wax (WAX), 15 parts hygroscopic agent (Cao-80), 1.5 parts activator (PEG-4000), 3 parts accelerator (DM / TMTD), and 1.5 parts sulfur.
[0033] Preparation method: The preparation method is basically the same as in Example 1. The fly ash is modified by a composite of silane coupling agent and titanate coupling agent, and the original fly ash is used directly.
[0034] Comparative Example 1 (Traditional Formula) This comparative example uses traditional automotive sealing strips without adding fly ash. The rubber sealing strip comprises the following raw materials in parts by weight: 100 parts EPDM, 150 parts carbon black N550, 100 parts white oil, 5 parts zinc oxide, 1.5 parts stearic acid, 1.5 parts flow aid (RL-16), 1 part microcrystalline wax (WAX), 15 parts hygroscopic agent (Cao-80), 1.5 parts activator (PEG-4000), 3 parts accelerator (DM / TMTD), and 1.5 parts sulfur.
[0035] Preparation method: The preparation method is basically the same as in Example 1, but does not involve the pretreatment steps of fly ash.
[0036] Comparative Example 2 (Unmodified fly ash) This comparative example uses unmodified fly ash, and the other formulations are the same as in Example 1: EPDM 100 parts, Carbon Black N550 140 parts, Fly Ash 140 parts, White Oil 100 parts, Zinc Oxide 5 parts, Stearic Acid 1.5 parts, Flow Aid (RL-16) 1.5 parts, Microcrystalline Wax (WAX) 1 part, Hygroscopic Agent (Cao-80) 15 parts, Activator (PEG-4000) 1.5 parts, Accelerator (DM / TMTD) 3 parts, Sulfur 1.5 parts.
[0037] Preparation method: The preparation method is basically the same as in Example 1, but the fly ash is not subjected to surface modification treatment and is used directly in its original state.
[0038] Test case Performance tests and effect analyses were conducted on the above-described embodiments and comparative examples.
[0039] 1. Mechanical properties Hardness testing standard: GB / T531.1-2008 Tensile strength and elongation at break test standard: GB / T528-2009 Tear strength test standard: GB / T528-2008 Table 1. Mechanical property test results 2. Comparison of vulcanization characteristics Mooney viscosity test standard: GB / T123.1-2016 Based on the provided performance test results, the fly ash rubber sealing strip of the present invention has the following vulcanization characteristics.
[0040] Table 2 The test results in Tables 1 and 2 show that the mechanical properties of Comparative Example 2 with added unmodified fly ash decreased significantly, indicating that the untreated fly ash has poor compatibility with the rubber matrix and cannot provide effective reinforcement. The mechanical properties of Examples 1 and 2 are comparable to the traditional formulation of Comparative Example 1, with some properties slightly reduced but within acceptable limits, while the material cost is significantly reduced. Example 2, containing reclaimed rubber, has a significant cost advantage. Although the mechanical properties are somewhat reduced, it still meets the basic requirements for automotive sealing strips. Examples 1, 3, and 4 achieve the best balance between cost and performance.
[0041] In summary, this invention, through specific surface modification techniques and formulation design, solves the problem of poor dispersibility and compatibility of fly ash in a rubber matrix through the synergistic effect of raw materials, and develops a high-performance fly ash automotive rubber sealing strip.
[0042] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A rubber sealing strip, characterized in that, The rubber sealing strip comprises the following raw materials in parts by weight: 80-100 parts of EPDM rubber, 100-140 parts of carbon black, 100-140 parts of modified fly ash, 70-100 parts of plasticizer, 5-8 parts of zinc oxide, 1-2 parts of stearic acid, 1-3 parts of flow aid, 1-2 parts of microcrystalline wax, 10-20 parts of hygroscopic agent, 1-2 parts of activator, 2-4 parts of accelerator, and 1-2 parts of vulcanizing agent.
2. The rubber sealing strip according to claim 1, characterized in that, The modified fly ash is obtained by heating and activating fly ash with a particle size D97≥1000 mesh, and then reacting the activated fly ash with a composite surface modifier to obtain modified fly ash; the composite surface modifier includes at least one of silane coupling agent, titanate coupling agent and aluminate coupling agent.
3. The rubber sealing strip according to claim 2, characterized in that, The conditions for the heating activation are: temperature of 110~130℃ and time of 30 min~60 min; The conditions for the modification reaction are: temperature 70~85℃, time 30 min~45 min.
4. The rubber sealing strip according to claim 2, characterized in that, The composite surface modifier includes a silane coupling agent, a titanate coupling agent, and an aluminate coupling agent; the mass ratio of the silane coupling agent, the titanate coupling agent, and the aluminate coupling agent is 1.8~2:0.8~1:0.8~1; the total concentration of the silane coupling agent, titanate coupling agent, and aluminate coupling agent in the composite surface modifier is 15~20%; the composite surface modifier accounts for 3~5% of the mass of the fly ash.
5. A rubber sealing strip according to any one of claims 1 to 4, characterized in that, The plasticizer includes white oil; The vulcanizing agent includes sulfur; The flow aid includes RL-16; The desiccant includes Cao-80; The active agent includes PEG-4000; The accelerator includes DM / TMTD.
6. A rubber sealing strip according to any one of claims 1 to 4, characterized in that, The rubber sealing strip also includes the following raw materials in parts by weight: 1 to 20 parts of reclaimed rubber.
7. A method for preparing a rubber sealing strip according to any one of claims 1 to 6, characterized in that, Includes the following steps: (1) Internal mixing: First, plasticize the EPDM rubber, then add some carbon black, modified fly ash and zinc oxide for mixing, and then add the remaining carbon black, plasticizer, flow aid, microcrystalline wax, hygroscopic agent, activator and stearic acid for mixing again to obtain a mixture; (2) Final grinding and vulcanization: an accelerator and a vulcanizing agent are added to the mixture for final grinding to obtain the precursor of automotive rubber sealing strip; (3) Extrusion molding: The rubber sealing strip precursor is extruded to obtain the automotive rubber sealing strip.
8. The method for preparing a rubber sealing strip according to claim 7, characterized in that, The plasticizing conditions in step (1) are: temperature of 110~120℃ and time of 0.5 min~4 min; The mixing conditions in step (1) are: temperature 110~120℃, time 3 min~5 min; The conditions for re-mixing in step (1) are: temperature of 120~130℃ and time of 5 min~10 min.
9. The method for preparing a rubber sealing strip according to claim 7, characterized in that, The specific method for final refining in step (2) is as follows: perform thin-pass 3 to 10 times and triangular pack 3 to 9 times.
10. An application of a rubber sealing strip, characterized in that, The rubber sealing strip according to any one of claims 1 to 6 is used in the sealing strip of an automobile.