A soft sound insulation coiled material for rail transit and a preparation method thereof

Abstract

This invention relates to the field of roll materials for rail transit, and discloses a soft sound insulation roll material for rail transit, comprising a styrene-based thermoplastic elastomer modified substrate, and one or more of non-woven fabric and aluminum foil; by weight, the styrene-based thermoplastic elastomer modified substrate comprises 6-10 parts of styrene-based thermoplastic elastomer resin base, 20-28 parts of plasticizer, 60-90 parts of powder filler, 80-120 parts of flame retardant modifier, 2-3 parts of lubricant, 0.3-0.6 parts of antioxidant, and 1-3 parts of tackifier; in preparation, the styrene-based thermoplastic elastomer resin base and plasticizer are first mixed and soaked to obtain a filler base; then other additives are mixed in to allow the styrene-based thermoplastic elastomer resin base to fully absorb the plasticizer, achieving more filler filling on the basis of low base content, that is, the resulting material has good sound insulation effect and low hardness.

Description

Technical Field

[0001] This invention relates to the field of roll materials for rail transit, and more specifically, to a soft sound insulation roll material for rail transit and its preparation method. Background Technology

[0002] With the rapid development of rail transit, train speeds have seen significant breakthroughs, leading to a marked increase in noise pollution. Conventional sound insulation rolls for rail transit require a thickness of at least 5mm to achieve effective sound insulation at high speeds. However, this increased thickness places stricter requirements on material flexibility during installation and transportation. Excessive rigidity results in lower flatness after unrolling, making cutting difficult and hindering fitting the rolls to the train's shell during curved installation. This leads to unstable adhesion between the rolls and the shell, creating cavities that negatively impact the overall sound insulation performance. Furthermore, the difficulty in cutting the sound insulation rolls creates challenges in material processing and on-site construction.

[0003] Currently, thin roll materials made from PVC resin-based formulations have high flexibility, making them suitable for high-speed trains. For example, patent CN103158314A discloses a multi-layer composite environmentally friendly flame-retardant sound-insulating roll material and its preparation method. Using PVC as the base material and adding DOP plasticizer to reduce the roll material's hardness, the layered technology results in higher sound insulation than normal extruded products. This allows for thinner products in high-sound-insulation applications, while also reducing filler usage to meet sound insulation requirements.

[0004] However, as the sound insulation requirements continue to increase, it is also necessary to improve the sound insulation effect by increasing the thickness. When the thickness of the roll material exceeds 5mm, its rigidity will be significantly improved. Then, a higher content of DOP plasticizer is used to improve the product's flexibility. However, this formulation system needs to be prepared and molded through processes such as pulping, calendering, and heating curing. On the one hand, the production process is complicated. On the other hand, PVC has a poor ability to adsorb DOP. When the DOP content exceeds the absorption limit of PVC, it is very easy to precipitate from the PVC resin, resulting in an increase in product hardness. Moreover, the precipitated DOP exists on the surface of the material, which will bring great risks to the adhesion of the material. In severe cases, it will cause the product to de-adhere and separate from the vehicle body.

[0005] To address the issue of plasticizer leaching, patent CN102675759A proposes a high-density, low-smoke-toxicity, flame-retardant sound insulation pad and its preparation method. It uses CPE and styrene-butadiene rubber as the base material, supplemented with heavy metal fillers, and employs a combination of open milling and internal mixing to produce the roll material. This roll material does not contain a large amount of plasticizer, thus avoiding the plasticizer leaching problem. However, the relatively high filler content still results in a higher roll material hardness. Furthermore, while the intumescent flame retardant has a certain smoke-suppressing effect, CPE contains a large amount of chlorine, which produces hydrogen chloride upon heating and combustion, resulting in high toxicity and low safety.

[0006] Therefore, there is an urgent need for a soft sound insulation roll material for rail transit that has low hardness, high safety, and good sound insulation effect. Summary of the Invention

[0007] The technical problem to be solved by this invention:

[0008] Currently, most sound insulation rolls used in rail transit are made of resin materials such as PVC, combined with plasticizers, flame retardants and other additives. However, for trains that travel at high speeds and generate excessive noise, existing sound insulation rolls have problems such as poor sound insulation effect or excessive material hardness, and cannot be efficiently applied to high-speed trains in rail transit.

[0009] The technical solution adopted in this invention is as follows:

[0010] This invention provides a flexible sound insulation roll material for rail transit, comprising a styrene-based thermoplastic elastomer modified substrate, and one or more of nonwoven fabric and aluminum foil; by weight, the styrene-based thermoplastic elastomer modified substrate comprises 6-10 parts of styrene-based thermoplastic elastomer resin base, 20-28 parts of plasticizer, 60-90 parts of powder filler, 80-120 parts of flame retardant modifier, 2-3 parts of lubricant, 0.3-0.6 parts of antioxidant, and 1-3 parts of tackifier.

[0011] Preferably, the styrene-based thermoplastic elastomer resin base material is one or more of SBS and SEBS. SBS can be one or more of linear or star-shaped structures. Specifically, the styrene-based thermoplastic elastomer resin base material can be selected from one or more of SBS1301, SBS1401, SBS1302, and SEBS6150.

[0012] Preferably, the plasticizer comprises naphthenic oil or white oil.

[0013] Preferably, the powder filler includes one or more of the following: heavy calcium carbonate, barium sulfate, talc.

[0014] Preferably, the flame retardant modifier includes one or more of aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, zinc stannate, and silane flame retardants.

[0015] Preferably, the tackifier is an elastomer grafted with polar groups; the polar groups include one or more of maleic anhydride and glycidyl methacrylate, and the elastomer includes one or more of SBS, SEBS, POE, PP elastomer, and PE.

[0016] Preferably, the antioxidant comprises a hindered phenolic-phosphite compound system.

[0017] Preferably, the lubricant includes one or more of stearic acid, PE wax, stearate, and erucamide.

[0018] The present invention also provides a method for preparing the above-mentioned flexible sound insulation roll material for rail transit, comprising the following steps:

[0019] S1 Take styrene-based thermoplastic elastomer resin base material and plasticizer, mix and soak for more than 1 hour to obtain filler base material;

[0020] S2 takes powder filler, flame retardant modifier, lubricant, antioxidant and thickener, mixes them into filler base material, puts them into internal mixer for plasticization, and then extrudes and granulates them through screw extruder to obtain improved granules;

[0021] S3 modifies the granules through an extruder, then extrudes them through a die into rolls of uniform thickness. The rolls are then thermally bonded with nonwoven fabric and / or aluminum foil using a multi-roll calender to obtain multi-layer composite soft sound insulation rolls.

[0022] The technical mechanism and beneficial effects of this invention are as follows:

[0023] The sound insulation effect of sound insulation materials mainly depends on the bulk density and thickness of the material. In this invention, the bulk density of the material is increased by increasing the filler content, thereby improving the sound insulation effect of the sound insulation roll material, so that it can simultaneously meet the requirements of good sound insulation effect and low hardness. Specifically, styrene-based thermoplastic elastomer resin is selected as the soft base material. This resin has excellent tensile strength, flexibility and low temperature resistance, and can fully absorb plasticizers such as naphthenic oil or white oil and powder fillers, achieving a high degree of absorption and filling. At the same time, the high oil-filling system can make the resulting sound insulation roll material have low hardness and good sound insulation effect. Detailed Implementation

[0024] 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.

[0025] This invention provides a flexible sound insulation roll material for rail transit, comprising a styrene-based thermoplastic elastomer modified substrate, and one or more of nonwoven fabric and aluminum foil; by weight, the styrene-based thermoplastic elastomer modified substrate comprises 6-10 parts of styrene-based thermoplastic elastomer resin base, 20-28 parts of plasticizer, 60-90 parts of powder filler, 80-120 parts of flame retardant modifier, 2-3 parts of lubricant, 0.3-0.6 parts of antioxidant, and 1-3 parts of tackifier;

[0026] The resin is composed of one or more of styrene-based thermoplastic elastomer resins, such as SBS and SEBS. SBS can be linear or star-shaped, specifically selected from SBS1301, SBS1401, SBS1302, SEBS6150, etc. The plasticizer is naphthenic oil or white oil, etc. The powder filler includes one or more of heavy calcium carbonate, barium sulfate, talc, etc. The flame retardant modifier is one or more of aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, zinc stannate, silane flame retardant, etc. Those skilled in the art can add zinc stannate according to the actual situation to retard flame and suppress smoke. The tackifier is an elastomer grafted with polar groups, wherein the polar groups are maleic anhydride or glycidyl methacrylate, etc., and the elastomer includes SBS or SEBS or POE or PP elastomer or PE, etc. The antioxidant is a hindered phenolic-phosphite compound system. The lubricant is stearic acid or PE wax or stearate or erucamide, etc.

[0027] In this invention, the styrene-based thermoplastic elastomer resin base material refers to a styrene-butadiene-styrene block copolymer. By adsorbing plasticizers and powder fillers into the styrene-based thermoplastic elastomer resin base material, the sound insulation effect of the roll material can be enhanced, while keeping the hardness of the roll material from increasing significantly. By using powder fillers in combination with flame retardant modifiers, the oxygen index of the product can reach more than 32%, while the hardness of the product is controlled below 40A. Introducing non-woven fabric and / or aluminum foil into the roll material can increase the tensile strength of the product to 2MPa, while maintaining the material's excellent softness and resilience.

[0028] The present invention also provides a method for preparing the above-mentioned flexible sound insulation roll material for rail transit, comprising the following steps:

[0029] S1 Take styrene-based thermoplastic elastomer resin base material and plasticizer, mix and soak for more than 1 hour until the styrene-based thermoplastic elastomer resin base material fully absorbs the plasticizer to obtain the filler base material;

[0030] S2 takes powder filler, flame retardant modifier, lubricant, antioxidant and thickener, mixes them into filler base material, puts them into internal mixer for plasticization, and then extrudes and granulates them through screw extruder to obtain improved granules;

[0031] S3 modifies the granules through an extruder, then extrudes them into uniform rolls through a die, and finally thermally composites them with nonwoven fabric and / or aluminum foil through a multi-roll calender to obtain a multi-layer composite soft sound insulation roll.

[0032] In this invention, the styrene-based thermoplastic elastomer resin base material is impregnated with plasticizer, allowing the styrene-based thermoplastic elastomer resin base material to fully absorb a large amount of plasticizer, thereby achieving greater flexibility and filler filling. That is, the amount of styrene-based thermoplastic elastomer resin base material used in this invention is significantly reduced. After filling with more plasticizer and filler, the material can be guaranteed to have both good sound insulation effect and very low hardness. SBS resin contains unsaturated bonds, resulting in poor aging resistance. Exposing the side covered with aluminum foil can improve the product's UV resistance.

[0033] <Example>

[0034] Example 1

[0035] By mass fraction, measure 10 parts of SBS1301 resin base, 2 parts of SBS-g-MAH, 24 parts of white oil, 100 parts of magnesium hydroxide, 75 parts of heavy calcium carbonate, 2 parts of zinc stearate, 0.25 parts of erucamide, and 2 parts of silane flame retardant.

[0036] First, styrene-based thermoplastic elastomer resin base material and white oil plasticizer are mixed and soaked for about 1.2 hours. During soaking, the material is stirred at low speed to improve the oil filling efficiency until the styrene-based thermoplastic elastomer resin base material fully absorbs the plasticizer to obtain the filler base material. Then, powder filler, magnesium hydroxide, zinc stearate, antioxidant and maleic anhydride grafted SBS are added to the internal mixer for plasticization and granulation using a screw extruder water ring granulation system. The obtained granules are added to a single screw extruder and made into a 5mm thick polymer roll material with a width of 1400mm through a die connected to the single screw extruder. A stronger reinforced nonwoven fabric and a 0.03mm thick composite aluminum foil that combines softness and strength are selected. The polymer roll material, nonwoven fabric and aluminum foil are composited on a three-roll calender to obtain a soft sound insulation roll material.

[0037] In this embodiment, the sound insulation roll material is a 5mm double-sided laminated non-woven fabric and aluminum foil product, with a sound insulation level of up to 35dB. The substrate itself has a hardness of 26A, the non-woven fabric side has a hardness of 45A, and the aluminum foil side has a hardness of 70A. The product has an oxygen index of 33%, a smoke density rating of no more than 20, no smoke generated in the combustion chamber, a tensile strength of 2.10MPa, and a surface density of 9.5kg / m³. 2 At the same time, its soft material gives it damping and shock absorption performance far exceeding that of rigid roll materials, making it suitable for use on components requiring vibration reduction, such as train floors, ceilings, and driver's cabs.

[0038] <Experimental Example>

[0039] Using the preparation process in Example 1, soft sound insulation rolls were prepared according to the raw material formulations in Tables 1 and 2 below, respectively, to obtain sound insulation roll samples of Examples 1-3 and Comparative Examples 1-5.

[0040] Table 1. Raw material formulations of sound insulation roll samples from Examples 1-3

[0041]

[0042]

[0043] Table 2 shows the raw material formulations of the sound insulation roll samples from Comparative Examples 1-5.

[0044]

[0045] Samples from Examples 1-3 and Comparative Examples 1-5 were randomly sampled, and their density, hardness, and other performance parameters were measured. The results are summarized in Table 3 below:

[0046] Table 3 Material properties of different samples

[0047]

[0048]

[0049] As shown in Table 3 above, by comparing Examples 1-3 with Comparative Examples 1-5, it can be seen that in the material system of Examples 1-3, even if the amount of substrate is small, it has significantly lower hardness, which can improve the softness of the material, so that it can be made into sound insulation rolls of the required size by cutting and other methods. Moreover, the low proportion of substrate can control the material density, so that it has higher sound insulation.

[0050] Furthermore, a comparison between Examples 1-3 and Comparative Example 5 shows that PP elastomer has a significantly poor adsorption capacity for plasticizers. Under high filling conditions, the surface adhesion of the modified substrate is greater, making the product prone to clumping after granulation, resulting in a difficult production process and a risk of plasticizer precipitation. In other words, the roll material proposed in this invention achieves a significantly better overall effect based on the holistic material system, resulting in better sound insulation and lower processing difficulty.

[0051] Overall, compared to Comparative Examples 1-5, the sound insulation rolls prepared using Examples 1-3 can simultaneously have lower hardness and sound insulation effect. That is, with comparable sound insulation effect, the material has better processing performance, which can solve the problems of difficult cutting and material processing of existing high-efficiency or high-thickness sound insulation rolls, making them applicable to more usage scenarios.

[0052] 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 flexible sound insulation roll material for rail transit, characterized in that, It includes styrene-based thermoplastic elastomer modified substrates, and also includes one or more of nonwoven fabrics and aluminum foil; By weight, the styrene-based thermoplastic elastomer modified substrate comprises 6-10 parts of styrene-based thermoplastic elastomer resin base, 20-28 parts of plasticizer, 60-90 parts of powder filler, 80-120 parts of flame retardant modifier, 2-3 parts of lubricant, 0.3-0.6 parts of antioxidant and 1-3 parts of tackifier.

2. The flexible sound insulation roll material for rail transit according to claim 1, characterized in that, The styrene-based thermoplastic elastomer resin base material is one or more of SBS and SEBS.

3. The flexible sound insulation roll material for rail transit according to claim 1, characterized in that, The plasticizer includes naphthenic oil or white oil.

4. The flexible sound insulation roll material for rail transit according to claim 1, characterized in that, The powder filler includes one or more of the following: heavy calcium carbonate, barium sulfate, talc, etc.

5. The flexible sound insulation roll material for rail transit according to claim 1, characterized in that, The flame retardant modifier includes one or more of aluminum hydroxide, magnesium hydroxide, ammonium polyphosphate, zinc stannate, and silane flame retardants.

6. The flexible sound insulation roll material for rail transit according to claim 1, characterized in that, The tackifier is an elastomer grafted with polar groups; The polar groups include one or more of maleic anhydride and glycidyl methacrylate, and the elastomer includes one or more of SBS, SEBS, POE, PP elastomer, and PE.

7. The flexible sound insulation roll material for rail transit according to claim 1, characterized in that, The antioxidants include a hindered phenolic-phosphite complex system.

8. The flexible sound insulation roll material for rail transit according to claim 1, characterized in that, The lubricant includes one or more of stearic acid, PE wax, stearate, and erucamide.

9. A method for preparing a flexible sound-insulating roll material for rail transit as described in any one of claims 1 to 8, characterized in that, Includes the following steps: S1 Take styrene-based thermoplastic elastomer resin base material and plasticizer, mix and soak for more than 1 hour to obtain filler base material; S2 Take powder filler, flame retardant modifier, lubricant, antioxidant and thickener, mix them into filler base material, put them into internal mixer for plasticization, and then extrude and granulate them through screw extruder to obtain improved granules; S3 improves the granules by plasticizing them in an extruder, then extrudes them into rolls of uniform thickness through a die, and then thermally composites them with nonwoven fabric and / or aluminum foil through a multi-roll calender to obtain a multi-layer composite soft sound insulation roll.

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