Processing and preparing method of floor foaming mute film
By combining modified graphite filler with polyolefin resin and utilizing the interlayer slip properties of graphite, the problem of unstable bubbles during polymer resin foaming was solved, resulting in a more uniform cell structure and better mechanical properties.
Patent Information
- Application Number
- CN202511182719.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-22
- Publication Date
- 2025-11-14
AI Technical Summary
During the foaming process, the bubbles in polymer resins are not easily maintained stably, resulting in uneven cell structure and affecting foaming quality and mechanical strength.
Modified graphite filler is formed by mixing graphite oxide with a silane coupling agent and adding a chemical foaming agent. It is then uniformly dispersed in polyolefin resin and subjected to irradiation crosslinking and foaming treatment. The slip properties between graphite layers are used to protect bubble growth.
It effectively reduces bubble breakage and coalescence, maintains bubble stability, and improves the uniformity of the cell structure and the mechanical properties of foamed products.
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention belongs to the field of polymer foaming materials technology, and specifically relates to a method for processing and preparing a floor foaming sound-absorbing film. Background Technology
[0002] In the production and processing of foamed soundproof flooring, resin, foaming agent, filler, and additives are blended and then extruded through a screw extruder to obtain a preform. After the preform is subjected to irradiation cross-linking treatment, it is then foamed into pores in a foaming equipment. The foamed soundproof flooring is based on the pore structure distribution obtained by foaming to exert sound insulation and buffering effects, thus playing a role in soundproof protection for the floor.
[0003] Polymer resins cannot be effectively processed before reaching their melting temperature. While the resin softens sufficiently after reaching the melting temperature, its melt strength also decreases significantly. This often leads to bubbles generated during foaming being difficult to maintain stably, causing them to easily break and coalesce, resulting in an uneven cell structure in the product and affecting foaming quality and the product's mechanical strength. Although irradiation crosslinking can improve the melt strength of the preform resin, thus benefiting the stability of bubbles generated during foaming and improving the mechanical properties of the foamed product, the applicant believes that irradiation crosslinking is equivalent to macroscopically intervening in the entire foaming system to improve its internal foaming stability. If further intervention could be made at the microscopic level of the foaming agent's vaporization and pore formation, it is believed that the foaming performance of the product would also be further improved. Summary of the Invention
[0004] To solve the above-mentioned technical problems, the present invention provides a method for processing and preparing a foamed sound-absorbing film for flooring, comprising the following steps:
[0005] (1) Disperse graphite oxide and silane coupling agent in a reaction solvent composed of water and dimethyl sulfoxide at a mass ratio of 1:2 to 5. Stir and react at 50°C to 80°C for 1 to 10 hours. Then add chemical foaming agent with a mass ratio of 4 to 8:1 to graphite oxide. Continue stirring for 3 to 5 hours and then dry to obtain modified graphite filler.
[0006] (2) By weight, 100-150 parts of polyolefin resin, 6-15 parts of modified graphite filler obtained in step (1), 1-2 parts of lubricant, and 0.2-2 parts of antioxidant are mixed and plasticized by screw extruder to obtain sheet material.
[0007] (3) The sheet obtained in step (2) is subjected to irradiation crosslinking treatment with an irradiation dose of 4 to 10 Mrad;
[0008] (4) The sheet after the irradiation crosslinking treatment in step (3) is put into the foaming furnace for foaming at a temperature of 210℃~240℃.
[0009] As a preferred option: In step (1), the reaction solvent is 50 to 100 times the mass of graphite oxide, and the volume ratio between water and dimethyl sulfoxide in the reaction solvent is 1:10 to 15. The reason for choosing dimethyl sulfoxide as the organic component in the reaction solvent is mainly because the chemical foaming agent AC (azodicarbonamide) available on the market is micron-sized and cannot directly and effectively enter the graphite interlayer. Dimethyl sulfoxide is one of the few solvents that can dissolve AC foaming agent smoothly. In this scheme, after AC foaming agent is dissolved in dimethyl sulfoxide, it can enter the graphite interlayer relatively smoothly. Secondly, dimethyl sulfoxide and water, the solvent used to promote the hydrolysis of silane coupling agent, are also miscible.
[0010] As a preferred option: In step (1), the silane coupling agent is KH-560 or KH-570. The silane coupling agent is hydrolyzed in the reaction solvent to generate silanol groups. After the silanol groups react and graft with the groups on the graphite oxide, the hydrophilic groups on the graphite oxide are transformed into hydrophobic groups, thereby promoting the effective dispersion of the graphite oxide material in the organic resin. At the same time, it is also beneficial to expand the gap between the graphite oxide layers to a certain extent, so that more chemical foaming agents can penetrate into the interlayer of the graphite material and be loaded.
[0011] As a preferred method, the drying in step (1) involves drying the resulting stirring system at 70℃~80℃ for 12~48 hours. The entire stirring system is directly heated and dried here, mainly because the amount of chemical foaming agent added during subsequent extrusion processing should be clearly defined. However, in actual operation of step (1), it cannot be guaranteed that all the chemical foaming agent enters the graphite interlayer or is stably loaded onto the graphite. Therefore, if solid-liquid separation is used here, some of the chemical foaming agent will be separated and removed along with the solvent, resulting not only in a reduction in the amount of foaming agent but also in the inability to know the specific amount of foaming agent actually used for product foaming, inevitably leading to excessive errors and hindering analysis and summarization after production trials. Therefore, based on the non-volatile characteristic of foaming agent AC, continuous heating at an appropriate temperature is used to evaporate only the solvent.
[0012] Preferably, the polyolefin resin in step (2) is one or a combination of low-density polyethylene, linear low-density polyethylene, and high-density polyethylene.
[0013] As a preferred option, the lubricant in step (2) is zinc stearate, which not only has a lubricating effect but can also act as a foaming agent.
[0014] As a preferred option: in step (2), by weight, it also includes 15 to 25 parts of polyolefin elastomer, 1 to 5 parts of crosslinking agent, and 1 to 3 parts of antibacterial agent, or a combination of several of them.
[0015] As a preferred option: in step (3), irradiation is performed using a high-energy electron beam of 2 to 2.5 MeV generated by an electron accelerator.
[0016] As a preferred option: in step (4), the sheet is preheated in a foaming oven at 70°C to 90°C for 1 to 2 minutes, and then foamed at the foaming temperature for 3 to 6 minutes.
[0017] The beneficial effects of this invention are as follows: After dissolving the chemical foaming agent, it is mixed and impregnated with hydrophobically modified graphite oxide material, allowing the chemical foaming agent to gradually penetrate into the interlayer region of the graphite. The graphite filler is then effectively sheared and dispersed in the resin material and extruded into a foaming masterbatch. During the foaming process of the masterbatch, a considerable number of bubbles are generated from the interlayer of the graphite. The graphite surrounding the bubbles forms a barrier and protection, which helps to reduce the breakage and merging of the bubbles. At the same time, the graphite surrounding layer outside the bubbles contacts the bubbles inward and abuts against the resin matrix outward. Since the graphite layers themselves have the lubricating characteristic of relative sliding, during the bubble expansion process, the graphite can adapt to the expansion of the bubbles through the relative sliding between the layers. The graphite layers that have separated from each other still adhere to the bubble surface and can continue to serve as an isolation and protective layer for the bubbles. Therefore, the surrounding effect of the graphite layers on the bubbles does not decrease significantly during the bubble expansion process.
[0018] In summary, the measures in this solution mainly focus on the foaming growth behavior inside the product. Based on the characteristic that the interlayers of graphite can slide against each other, the intervention of graphite material forms a continuous barrier to protect the growth of bubbles inside the product, effectively reducing the rupture and merging of bubbles during the foaming process, maintaining bubble stability and making the cell structure uniform, thereby giving the foamed product better mechanical performance. Detailed Implementation
[0019] Example 1
[0020] (1) 1 part by weight of graphite oxide (GY-64, the same below) and 3.2 parts by weight of silane coupling agent KH-560 were dispersed together in 90 parts by weight of a reaction solvent made of water and dimethyl sulfoxide in a volume ratio of 1:14. After stirring at 65°C for 7 hours, the heating and heat preservation measures were removed and the temperature was allowed to drop naturally. At the beginning of the cooling, 5 parts by weight of AC foaming agent were added to the mixture. After stirring for 5 hours, the resulting stirring system was transferred to a tray and dried at 80°C for 24 hours under nitrogen protection to obtain modified graphite filler.
[0021] (2) By weight, 80 parts of low-density polyethylene (2602TX17, the same below), 35 parts of high-density polyethylene (DGDK-3364NT), 15 parts of POE elastomer (8999, the same below), 9 parts of modified graphite filler obtained in step (1), 1.5 parts of crosslinking aid TAIC, 2 parts of zinc stearate, 1 part of antioxidant 1010, and 1 part of antibacterial agent sodium pyrithione are mixed in a high-speed mixer and then plasticized and extruded through a screw extruder to obtain a sheet. The screw speed is 90 rpm, the extrusion temperature is 120℃~140℃, and the die temperature is 125℃.
[0022] (3) The sheet obtained in step (2) is irradiated and crosslinked by a high-energy electron beam generated by an electron accelerator. The irradiation energy is 2 MeV and the irradiation dose is 4 Mrad.
[0023] (4) The sheet after the irradiation crosslinking treatment in step (3) enters the foaming furnace. The sheet is preheated in the foaming furnace at 75°C for 1 minute, 85°C for 1 minute, 215°C for 40 seconds, 225°C for 2 minutes, and 230°C for 1 minute.
[0024] Example 2
[0025] (1) 1 part by weight of graphite oxide and 3.5 parts by weight of silane coupling agent KH-560 were dispersed together in 120 parts by weight of a reaction solvent made of water and dimethyl sulfoxide in a volume ratio of 1:11. After stirring at 70°C for 6 hours, the heating and heat preservation measures were removed and the temperature was allowed to drop naturally. At the beginning of the cooling, 5.5 parts by weight of AC foaming agent were added. After stirring for 5 hours, the resulting stirring system was transferred to a tray and dried at 80°C for 24 hours under nitrogen protection to obtain modified graphite filler.
[0026] (2) By weight, 70 parts of low-density polyethylene, 50 parts of high-density polyethylene, 20 parts of POE elastomer, 10 parts of modified graphite filler obtained in step (1), 1.8 parts of crosslinking aid TAIC, 2 parts of zinc stearate, 1 part of antioxidant 1010, and 1 part of antibacterial agent sodium pyrithione are mixed in a high-speed mixer and then plasticized and extruded through a screw extruder to obtain a sheet. The screw speed is 90 rpm, the extrusion temperature is 120℃~140℃, and the die temperature is 125℃.
[0027] (3) The sheet obtained in step (2) is irradiated and crosslinked by a high-energy electron beam generated by an electron accelerator. The irradiation energy is 2.5 MeV and the irradiation dose is 5 Mrad.
[0028] (4) The sheet after the irradiation crosslinking treatment in step (3) enters the foaming furnace. The sheet is preheated in the foaming furnace at 75°C for 1 minute, 85°C for 1 minute, 210°C for 2 minutes, 225°C for 1 minute, and 230°C for 1 minute.
[0029] Example 3
[0030] (1) 1 part by weight of graphite oxide and 3 parts by weight of silane coupling agent KH-560 were dispersed together in 90 parts by weight of a reaction solvent made of water and dimethyl sulfoxide in a volume ratio of 1:14. After stirring at 65°C for 7 hours, the heating and heat preservation measures were removed and the temperature was allowed to drop naturally. At the beginning of the cooling, 4.5 parts by weight of AC foaming agent were added. After stirring for 5 hours, the resulting stirring system was transferred to a tray and dried at 80°C for 24 hours under nitrogen protection to obtain modified graphite filler.
[0031] (2) By weight, 80 parts of low-density polyethylene, 35 parts of high-density polyethylene, 15 parts of POE elastomer, 9 parts of modified graphite filler obtained in step (1), 1 part of crosslinking aid TAIC, 2 parts of zinc stearate, 1 part of antioxidant 1010 and 1 part of antibacterial agent sodium pyrithione are mixed in a high-speed mixer and then plasticized and extruded through a screw extruder to obtain a sheet. The screw speed is 90 rpm, the extrusion temperature is 120℃~140℃, and the die temperature is 125℃.
[0032] (3) The sheet obtained in step (2) is irradiated and crosslinked by a high-energy electron beam generated by an electron accelerator. The irradiation energy is 2 MeV and the irradiation dose is 4 Mrad.
[0033] (4) The sheet after the irradiation crosslinking treatment in step (3) enters the foaming furnace. The sheet is preheated in the foaming furnace at 80°C for 1 minute, 90°C for 1 minute, 220°C for 1.5 minutes, 225°C for 2 minutes, and 230°C for 1 minute.
[0034] Comparative Example 1
[0035] The AC foaming agent and silane coupling agent grafted modified graphite oxide were added separately to the screw extruder in step (2), and the remaining components and operations were the same as in Example 1:
[0036] (1) 1 part by weight of graphite oxide and 3.2 parts by weight of silane coupling agent KH-560 were dispersed together in 90 parts by weight of a reaction solvent made of water and dimethyl sulfoxide in a volume ratio of 1:14. After stirring at 65°C for 7 hours, the heating and heat preservation measures were removed and the temperature was allowed to drop naturally. Stirring was continued for 5 hours as the temperature dropped. The resulting stirring system was then transferred to a tray and dried at 80°C for 24 hours under nitrogen protection to obtain hydrophobic grafted graphite filler.
[0037] (2) By weight, 80 parts of low-density polyethylene, 35 parts of high-density polyethylene, 15 parts of POE elastomer, 4.1 parts of hydrophobic grafted graphite filler obtained in step (1), 4.9 parts of AC foaming agent, 1.5 parts of crosslinking aid TAIC, 2 parts of zinc stearate, 1 part of antioxidant 1010, and 1 part of antibacterial agent sodium pyrithione are mixed in a high-speed mixer and then plasticized and extruded through a screw extruder to obtain a sheet. The screw speed is 90 rpm, the extrusion temperature is 120℃~140℃, and the die temperature is 125℃.
[0038] (3) The sheet obtained in step (2) is irradiated and crosslinked by a high-energy electron beam generated by an electron accelerator. The irradiation energy is 2 MeV and the irradiation dose is 4 Mrad.
[0039] (4) The sheet after the irradiation crosslinking treatment in step (3) enters the foaming furnace. The sheet is preheated in the foaming furnace at 75°C for 1 minute, 85°C for 1 minute, 215°C for 40 seconds, 225°C for 2 minutes, and 230°C for 1 minute.
[0040] Comparative Example 2
[0041] After ultrasonically exfoliating graphite oxide into graphene oxide, modified graphite filler was prepared according to the process of Example 1. The remaining components and operations were the same as in Example 1.
[0042] (1) Disperse 1 part by weight of graphite oxide in 90 parts by weight of a reaction solvent composed of water and dimethyl sulfoxide in a volume ratio of 1:14 and sonicate (frequency 60 kHz, power 60 W, time 10 minutes). Then add 3.2 parts by weight of silane coupling agent KH-560 and stir at 65°C for 7 hours. Remove the heating and heat preservation measures and start natural cooling. At the beginning of cooling, add 5 parts by weight of AC foaming agent and continue stirring for 5 hours. Transfer the resulting stirring system to a tray and dry at 80°C for 24 hours under nitrogen protection to obtain modified graphite filler.
[0043] (2) By weight, 80 parts of low-density polyethylene, 35 parts of high-density polyethylene, 15 parts of POE elastomer, 9 parts of modified graphite filler obtained in step (1), 1.5 parts of crosslinking aid TAIC, 2 parts of zinc stearate, 1 part of antioxidant 1010, and 1 part of antibacterial agent sodium pyrithione are mixed in a high-speed mixer and then plasticized and extruded through a screw extruder to obtain a sheet. The screw speed is 90 rpm, the extrusion temperature is 120℃~140℃, and the die temperature is 125℃.
[0044] (3) The sheet obtained in step (2) is irradiated and crosslinked by a high-energy electron beam generated by an electron accelerator. The irradiation energy is 2 MeV and the irradiation dose is 4 Mrad.
[0045] (4) The sheet after the irradiation crosslinking treatment in step (3) enters the foaming furnace. The sheet is preheated in the foaming furnace at 75°C for 1 minute, 85°C for 1 minute, 215°C for 40 seconds, 225°C for 2 minutes, and 230°C for 1 minute.
[0046] The foamed sheets from the above embodiments and comparative embodiments were tested (GB / T 6344-2008, three samples were tested and the average was taken). The test results are as follows:
[0047]
[0048] As can be seen from the table above, the mechanical properties of the foamed product of Example 1 are significantly better than those of Comparative Example 1 and Comparative Example 2. This is because in the process of Example 1, a considerable portion of the chemical foaming agent is incorporated into the spaces between the graphite material layers beforehand. During the foaming and growth process of this foaming agent, it is surrounded by the graphite material to form a continuous isolation and protection for the bubbles, thereby effectively reducing the merging and rupture of bubbles during the growth process of the product. This results in the foamed product of Example 1 having a more uniform cell structure compared to Comparative Example 1 and Comparative Example 2.
[0049] In Comparative Example 2, after ultrasonic exfoliation of the graphite oxide, a large number of graphite flakes were irreversibly separated from each other. As a result, the added chemical foaming agent could not enter between the graphite flakes, and the generated bubbles could not grow in the continuous surrounding of the graphite flakes, thus failing to effectively reduce the merging and rupture of bubbles.
[0050] Furthermore, the applicant believes that although the lack of ultrasonic exfoliation of the graphite oxide in Example 1, which represents this solution, results in less ideal graphite dispersibility compared to Example 2, and may even lead to insufficient dispersion among the bubbles grown in these graphite sheets, the continued surrounding and blocking effect of the graphite sheets on the bubbles in this solution effectively prevents the bubbles from merging, even if they are not sufficiently dispersed. In summary, using unexfoliated graphite oxide is significantly more beneficial for the stability of bubble growth.
Claims
1. A method for processing and preparing a foamed sound-absorbing membrane for flooring, characterized in that: The preparation method includes the following steps: (1) Disperse graphite oxide and silane coupling agent in a reaction solvent composed of water and dimethyl sulfoxide at a mass ratio of 1:2 to 5, stir and react at 50°C to 80°C for 1 to 10 hours, then add chemical foaming agent with a mass ratio of 4 to 8:1 to the graphite oxide, continue stirring for 3 to 5 hours, and then dry to obtain modified graphite filler; (2) By weight, 100-150 parts of polyolefin resin, 6-15 parts of the modified graphite filler obtained in step (1), 1-2 parts of lubricant, and 0.2-2 parts of antioxidant are mixed and plasticized by screw extruder to obtain sheet material. (3) The sheet obtained in step (2) is subjected to irradiation crosslinking treatment with an irradiation dose of 4 to 10 Mrad; (4) The sheet after the irradiation crosslinking treatment in step (3) is put into a foaming furnace for foaming at a foaming temperature of 210℃~240℃.
2. The method for processing and preparing the floor foam sound-absorbing membrane as described in claim 1, characterized in that: In step (1), the reaction solvent is 50 to 100 times the mass of the graphite oxide.
3. The method for processing and preparing the floor foam sound-absorbing membrane as described in claim 1, characterized in that: In step (1), the volume ratio between water and dimethyl sulfoxide in the reaction solvent is 1:10-15.
4. The method for processing and preparing the floor foam sound-absorbing membrane as described in claim 1, characterized in that: In step (1), the silane coupling agent is KH-560 or KH-570.
5. The method for processing and preparing the floor foam sound-absorbing membrane as described in claim 1, characterized in that: The drying process described in step (1) involves drying the resulting stirred system at 70°C to 80°C for 12 to 48 hours.
6. The method for processing and preparing the floor foam sound-absorbing membrane as described in claim 1, characterized in that: In step (2), the polyolefin resin is one or a combination of several of low-density polyethylene, linear low-density polyethylene, and high-density polyethylene.
7. The method for processing and preparing the floor foam sound-absorbing film as described in claim 1, characterized in that: The lubricant mentioned in step (2) is zinc stearate.
8. The method for processing and preparing the floor foam sound-absorbing membrane as described in claim 1, characterized in that: In step (2), by weight, it also includes 15 to 25 parts of polyolefin elastomer, 1 to 5 parts of crosslinking agent, and 1 to 3 parts of antibacterial agent, or a combination of several of them.
9. The method for processing and preparing the floor foam sound-absorbing membrane as described in claim 1, characterized in that: In step (3), the irradiation is performed using a high-energy electron beam of 2 to 2.5 MeV generated by an electron accelerator.
10. The method for processing and preparing the floor foam sound-absorbing membrane as described in claim 1, characterized in that: In step (4), the sheet is preheated in the foaming oven at 70°C to 90°C for 1 to 2 minutes, and then foamed at the foaming temperature for 3 to 6 minutes.