Microsphere foaming thermoplastic elastomer coiled material and preparation method thereof

Abstract

The invention discloses a microsphere foaming thermoplastic elastomer coiled material, which is prepared from 50 to 85 parts of styrene thermoplastic elastomer, 3 to 5 parts of styrene-butadiene-glycidyl methacrylate copolymer, 10 to 20 parts of ethylene-vinyl acetate (EVA), 3 to 5 parts of maleic anhydride grafted EVA, 0.5 to 2.0 parts of cis-oleyl primary amine, 1.5 to 7 parts of silane coupling agent treated thermal expansion microsphere foaming agent and 20 to 40 parts of talcum powder. 1-2 parts of an antioxidant and 5-10 parts of a plasticizer. The microsphere foaming thermoplastic elastomer coiled material is fine and uniform in foam hole, high in percentage of close area, and good in tensile strength, impact absorption performance and wear resistance.

Description

Technical Field

[0001] This invention belongs to the field of thermoplastic elastomer technology, specifically relating to a microsphere foamed thermoplastic elastomer roll and its preparation method. Background Technology

[0002] Thermoplastic elastomer foams, combining the elasticity of rubber with the processability of plastics, are increasingly in demand in fields such as automotive interiors, building sealing, and sports protection. Among these, styrene-based thermoplastic elastomers (such as SEBS) have become the preferred base material for foams due to their excellent aging resistance and mechanical properties. However, traditional foaming processes often use chemical foaming agents, which suffer from problems such as uneven cell structure, low closed-cell ratio, and large compression set, making it difficult to meet the precision requirements of high-end applications.

[0003] Currently, there are related technologies for microfoamed thermoplastic elastomer materials. For example, patent 202010025522.2 provides a microfoamed thermoplastic elastomer material and its preparation method, containing components such as polypropylene, styrene-based elastomers, white oil, propylene-based elastomers, and foamed microspheres. The wide extrusion temperature range of 100~300℃ in this invention may lead to insufficient expansion of the foamed microspheres at low temperatures and excessive expansion or even rupture at high temperatures. Furthermore, the blending of multiple polymer types can easily result in uneven dispersion due to compatibility differences, thus affecting the uniformity of bubble density and the stability of mechanical properties such as tensile strength and impact resistance. Patent 201811454753.4 proposes a physically foamed thermoplastic elastomer composition for floating cables and its preparation method, containing SEBS, polypropylene, etc., which is prepared by stirring and mixing at 300~600 r / min and extruding and granulating at 140~170℃. Although this material is suitable for the needs of floating cables, it uses acrylic microsphere foaming agent. If the extrusion temperature fluctuates, the foaming agent is prone to uneven expansion. In addition, it relies on maleic anhydride compatibilizer. If the dosage is not properly controlled, it may affect the compatibility of each component, thereby reducing the mechanical and electrical insulation stability of the material.

[0004] To address the aforementioned issues, the industry urgently needs to develop a microsphere-foamed thermoplastic elastomer roll material with fine and uniform pores, high closed-cell ratio, excellent tensile strength, impact absorption performance, and wear resistance, in order to meet the technical requirements of fields such as semi-prefabricated running tracks. Summary of the Invention

[0005] To address the aforementioned problems, this invention provides a microsphere-foamed thermoplastic elastomer roll material and its preparation method. This thermoplastic elastomer possesses excellent overall compatibility while exhibiting good flexibility, mechanical properties, and high resilience. Furthermore, the use of microsphere foaming technology improves the material's processability.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: A microsphere-foamed thermoplastic elastomer roll material, comprising the following components in parts by weight: 50-85 parts of styrene-based thermoplastic elastomer, 3-5 parts of styrene-butadiene-glycidyl methacrylate copolymer 10-20 parts of ethylene-vinyl acetate (EVA) 3-5 parts of maleic anhydride grafted onto EVA 0.5-2.0 parts of cis-oil-based primary amine. 1.5-7 parts of thermally expanding microsphere foaming agent treated with silane coupling agent. 20-40 parts talcum powder 1-2 parts antioxidant 5-10 parts plasticizer.

[0007] Preferably, the styrene-based thermoplastic elastomer is one of the SEBS elastomers YH-503, YH-506, and YH-511.

[0008] Preferably, the VA content of the ethylene-vinyl acetate is 5% to 10% by mass.

[0009] Preferably, the maleic anhydride grafting rate in the maleic anhydride-grafted EVA is 1.2%.

[0010] Preferably, the styrene-butadiene-glycidyl methacrylate copolymer is Jia Yi Rong SBG-001.

[0011] Preferably, the particle size of the silane coupling agent-treated thermal expansion microsphere foaming agent is 25~31μm, and the foaming temperature is 155~165℃.

[0012] Preferably, in the silane coupling agent treated thermal expansion microsphere foaming agent, the weight ratio of silane coupling agent to thermal expansion microsphere foaming agent is (0.5~2):(1~5).

[0013] Preferably, the particle size of the talc powder is between 800 and 2000 mesh.

[0014] Preferably, the plasticizer is epoxidized soybean oil.

[0015] Preferably, the silane coupling agent is 3-diethylenetriaminepropyltrimethoxysilane.

[0016] Preferably, the antioxidant is a compound of AO1010 and AO168, wherein the weight ratio of AO1010 to AO168 is 1:1 to 2:1.

[0017] This invention also provides a method for preparing the above-mentioned microsphere foamed thermoplastic elastomer roll material, comprising the following steps: (1) Styrene-based thermoplastic elastomer, styrene-butadiene-glycidyl methacrylate copolymer, ethylene-vinyl acetate (EVA), maleic anhydride-grafted EVA, talc, antioxidant, and plasticizer are uniformly mixed and referred to as mixture 1; (2) The thermal expansion microsphere foaming agent and the silane coupling agent are mixed and reacted to obtain mixture 2; (3) Mixture 1, mixture 2 and cis-oil-based primary amine are mixed and then extruded. The extrusion temperature is 130~150℃ in the first section and 170~200℃ in the second section to obtain a uniform pore melt. (4) The foam melt is extruded and cooled to obtain the microsphere foamed thermoplastic elastomer roll.

[0018] Preferably, the mixing described in step (1) or step (2) is carried out in a high-speed mixer.

[0019] Preferably, the reaction described in step (2) is carried out at room temperature.

[0020] Preferably, the extrusion in step (3) is performed using a twin-screw extruder with a screw speed of 100~300 rpm. The initial temperature of 130~150°C in the front section of the extrusion can suppress pre-foaming, while the final temperature of 170~200°C can trigger expansion.

[0021] Preferably, the shaping in step (4) is calendering shaping. More preferably, the calendering is carried out in a roll press.

[0022] Preferably, the thickness of the roll material in step (4) is 3~5mm.

[0023] The beneficial effects of this invention are as follows: (1) In this invention, a styrene-butadiene-glycidyl methacrylate copolymer (preferred brand name is Jia Yi Rong SBG-001) is added. It is a toughening compatibilizer with a core-shell structure. The core layer introduces butadiene elastomer, and the shell layer contains highly active epoxy groups. On the one hand, it ensures good flexibility. On the other hand, the highly active epoxy groups of the shell layer can react with cis-oil-based primary amine and the surface amino groups of thermal expansion microsphere foaming agent treated with coupling agent. The compatibility between components is improved through the formation of covalent bonds, which helps to improve the tensile strength, impact absorption performance and wear resistance of the material.

[0024] (2) In this invention, the thermally expandable microspheres are surface-treated with a coupling agent. Multifunctional active amino groups are attached to the surface of the thermally expandable microspheres through silane hydrolysis. These multifunctional active amino groups can react with the epoxy groups of the styrene-butadiene-glycidyl methacrylate copolymer, the maleic anhydride groups of maleic anhydride-grafted EVA, and the epoxy groups of the plasticizer epoxidized soybean oil in the elastomer composition. This ensures the compatibility and dispersibility of the thermally expandable microspheres in the system, resulting in a roll material with fine and uniform pores and a high closed-cell rate. Simultaneously, the added cis-oil-based primary amine can also react with the aforementioned groups, forming strong covalent interactions at the interface. Furthermore, the long carbon chain groups of the cis-oil-based primary amine have similar polarity to the low-polarity segments of styrene-based thermoplastic elastomers, promoting overall component compatibility.

[0025] (3) The styrene-based thermoplastic elastomer SEBS of the present invention has a triblock saturated structure, which has excellent weather resistance and flexibility, making it suitable as a roll material. At the same time, the addition of ethylene-vinyl acetate (EVA) helps to improve the tear resistance of the roll material, and its polar groups also help to disperse inorganic fillers, further improving the elasticity of the roll material. In the extrusion stage of the present invention, the temperature is controlled in stages. The first stage of 130~150℃ can suppress pre-foaming, so that the components are fully sheared and mixed evenly. The second stage of 170~200℃ can trigger expansion. This staged temperature control method can further ensure the uniform foaming of the thermal expansion microsphere foaming agent, so that the roll material has excellent tensile strength, impact absorption performance and wear resistance, and is suitable for semi-prefabricated running tracks, with both lightweight and high resilience characteristics. Detailed Implementation

[0026] The present invention will be further illustrated and explained below with reference to preferred embodiments and experimental data.

[0027] Example 1 (1) Mix 65 parts of SEBS (YH-503), 4 parts of Jia Yi Rong SBG-001, 15 parts of EVA with 7% VA content, 4 parts of maleic anhydride-grafted EVA, 30 parts of 1250 mesh talc powder, 1.5 parts of antioxidant (1010 and 168 are compounded in a mass ratio of 1:1) and 7 parts of epoxidized soybean oil in a high-speed mixer to obtain mixture 1.

[0028] (2) Three parts of thermal expansion microsphere foaming agent with a particle size of 25~31μm and an initiation temperature of 155~165℃ were mixed with 1.2 parts of coupling agent 3-diethylenetriaminepropyltrimethoxysilane for surface treatment to obtain mixture 2.

[0029] (3) Mixture 1, mixture 2 and 1.2 parts of cis-oil-based primary amine were added to a twin-screw extruder for melt blending and extrusion. The front section temperature was 140℃, the back section temperature was 180℃, and the speed was 200rpm. The melt was cooled and shaped by calendering rollers to obtain microsphere foamed thermoplastic elastomer rolls.

[0030] Example 2 (1) Mix 50 parts of SEBS (YH-506), 3 parts of Jia Yi Rong SBG-001, 10 parts of EVA with 5% VA content, 3 parts of maleic anhydride grafted EVA, 20 parts of 800 mesh talc powder, 1 part of antioxidant (1010 and 168 are compounded in a mass ratio of 2:1), and 5 parts of epoxidized soybean oil in a high-speed mixer to obtain mixture 1.

[0031] (2) 1 part of thermal expansion microsphere foaming agent with a particle size of 25~31μm and an initiation temperature of 155~165℃ was mixed with 0.5 part of coupling agent 3-diethylenetriaminepropyltrimethoxysilane for surface treatment to obtain mixture 2.

[0032] (3) Mixture 1, mixture 2 and 0.5 parts of cis-oil-based primary amine were added to a twin-screw extruder for melt blending and extrusion. The front section temperature was 130°C, the back section temperature was 170°C, and the speed was 100 rpm. The melt was cooled and shaped by calendering rollers to obtain microsphere foamed thermoplastic elastomer rolls. Example 3

[0033] (1) Mix 85 parts of SEBS (YH-511), 5 parts of Jia Yi Rong SBG-001, 20 parts of EVA with VA content of 10%, 5 parts of maleic anhydride grafted EVA, 40 parts of 2000 mesh talc powder, 2 parts of antioxidant (1010 and 168 are compounded in a mass ratio of 2:1) and 10 parts of epoxidized soybean oil in a high-speed mixer to obtain mixture 1.

[0034] (2) Five parts of thermal expansion microsphere foaming agent with a particle size of 25~31μm and an initiation temperature of 155~165℃ were mixed with two parts of coupling agent 3-diethylenetriaminepropyltrimethoxysilane for surface treatment to obtain mixture 2.

[0035] (3) Mixture 1, mixture 2 and 2.0 parts of cis-oil-based primary amine were added to a twin-screw extruder for melt blending and extrusion. The front section temperature was 150℃, the back section temperature was 200℃, and the speed was 300rpm. The melt was cooled and shaped by calendering rollers to obtain microsphere foamed thermoplastic elastomer rolls.

[0036] Comparative Example 1 This comparative example provides a method for preparing a microsphere-foamed thermoplastic elastomer roll material: (1) Mix 65 parts SEBS (YH-503), 15 parts EVA, 4 parts maleic anhydride-grafted EVA, 35 parts naphthenic oil, 30 parts 1250 mesh talc powder, 1.5 parts antioxidant (1010 and 168 are compounded in a mass ratio of 1:1) and 7 parts epoxidized soybean oil in a high-speed mixer to obtain a mixture.

[0037] (2) Add 3 parts of thermal expansion microsphere foaming agent with particle size of 25~31μm and foaming temperature of 155~165℃ directly to the mixture, stir evenly, and then add it to the twin screw extruder for melt blending and extrusion. The temperature is 170℃ throughout the process and the speed is 200rpm. The melt is cooled and shaped by calendering rollers to obtain thermoplastic elastomer roll material.

[0038] Note: Naphthenic oil was added as a plasticizer in this comparative example. It does not contain Jia Yi Rong SBG-001 or cis-oil-based primary amine. To ensure the processability of SEBS, 35 parts of naphthenic oil were added as a plasticizer.

[0039] Comparative Example 2 The only difference between this embodiment and Example 1 is that cis-oleoyl primary amine is not added.

[0040] Comparative Example 3 The only difference between this embodiment and Embodiment 1 is that silane modification is not used.

[0041] Comparative Example 4 The only difference between this embodiment and Embodiment 1 is that the entire process is extruded at 170°C.

[0042] The thermoplastic elastomers obtained in Examples 1-3 and Comparative Example 1 were tested for Shore A hardness, tensile strength, resilience, impact absorption, abrasion resistance, and processing torque. The test results are shown in Table 1. Tensile strength was tested according to GB / T1040.3-2006 standard at room temperature. Abrasion resistance was tested according to GB / T17657 standard, using a CS-10 grinding wheel at 1000 rpm, with a mass loss (g); a smaller value indicates better abrasion resistance. Processing torque was obtained using a torque rheometer.

[0043] sample Shore A hardness Tensile strength (MPa) Rebound rate (%) Shock absorption (%) Abrasion resistance (g) Machining torque (N·m) Example 1 65 12.5 68 48 0.6 73 Example 2 62 11.8 65 47 0.6 72 Example 3 68 13.2 70 46 0.5 75 Comparative Example 1 50 7.8 45 28 3.3 60 Comparative Example 2 55 8.3 51 32 2.1 67 Comparative Example 3 57 8.5 55 34 1.5 70 Comparative Example 4 60 9.5 58 41 1.2 71 Standard specified value ≥0.70 35~50 * The values ​​specified in the table are the test index values ​​for runway physical performance under the GB / T 22517.6-2020 standard.

[0044] As can be seen from the data in Table 1, the samples in Examples 1-3 exhibited better Shore A hardness, tensile strength, resilience, impact absorption, and abrasion resistance. It is evident that the addition of cis-oil-based primary amines facilitated the crosslinking of the styrene-butadiene-glycidyl methacrylate copolymer, the thermally expandable microsphere foaming agent, and maleic anhydride-grafted EVA, contributing to improved tensile strength, resilience, impact absorption, and abrasion resistance. Furthermore, the thermally expandable microsphere foaming agent, surface-treated with the coupling agent 3-diethylenetriaminepropyltrimethoxysilane, formed covalent bonds with the epoxy groups in the system while retaining the surface-active amino groups. Simultaneously, the uniform dispersion of the microspheres created a dense cellular structure with high closed-cell ratio, reducing cell collapse under external forces and further improving the material's tensile strength, resilience, and impact absorption. Compared to ordinary foamed products, the increased Shore A hardness indicates that the synergistic effect of the components in this invention resulted in a more stable network structure, reducing the migration and exudation of plasticizers, thereby improving the material's hardness and enhancing its abrasion resistance. The processing torque of Examples 1-3 is higher than that of Comparative Example 1. This is because the amount of plasticizer used in this invention is reduced and a partially cross-linked structure is formed, but it is still within a reasonable processing range. This indicates that while ensuring the improvement of material performance, the added components do not excessively affect its processing performance.

[0045] Although the present invention has been illustrated and described with specific embodiments, it should be understood that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; those skilled in the art should understand that modifications can be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein, without departing from the spirit and scope of the present invention; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention; therefore, this means that all such substitutions and modifications that fall within the scope of the present invention are included in the appended claims.

Claims

1. A microsphere-foamed thermoplastic elastomer roll material, characterized in that, The components include the following parts by weight: 50-85 parts of styrene-based thermoplastic elastomer, 3-5 parts of styrene-butadiene-glycidyl methacrylate copolymer 10-20 parts of ethylene-vinyl acetate 3-5 parts of maleic anhydride grafted onto EVA 0.5-2.0 parts of cis-oil-based primary amine. 1.5-7 parts of thermally expanding microsphere foaming agent treated with silane coupling agent. 20-40 parts talcum powder 1-2 parts antioxidant 5-10 parts plasticizer.

2. The microsphere foamed thermoplastic elastomer roll material according to claim 1, characterized in that, The styrene-based thermoplastic elastomer is one of the SEBS elastomers YH-503, YH-506, and YH-511.

3. The microsphere-foamed thermoplastic elastomer roll material according to claim 1, characterized in that, The styrene-butadiene-glycidyl methacrylate copolymer is Jia Yi Rong SBG-001.

4. The microsphere-foamed thermoplastic elastomer roll material according to claim 1, characterized in that, The silane coupling agent-treated thermal expansion microsphere foaming agent has a particle size of 25~31μm and an initiation temperature of 155~165℃.

5. The microsphere-foamed thermoplastic elastomer roll material according to claim 1, characterized in that, In the silane coupling agent treated thermal expansion microsphere foaming agent, the weight ratio of silane coupling agent to thermal expansion microsphere foaming agent is (0.5~2):(1~5).

6. The microsphere-foamed thermoplastic elastomer roll material according to claim 1, characterized in that, The talc powder has a particle size between 800 and 2000 mesh.

7. The microsphere-foamed thermoplastic elastomer roll material according to claim 1, characterized in that, The plasticizer mentioned is epoxidized soybean oil.

8. The microsphere-foamed thermoplastic elastomer roll material according to claim 1, characterized in that, The silane coupling agent is 3-diethylenetriaminepropyltrimethoxysilane.

9. The microsphere-foamed thermoplastic elastomer roll material according to claim 1, characterized in that, The antioxidant is a compound of AO1010 and AO168, wherein the weight ratio of AO1010 to AO168 is 1:1 to 2:

1.

10. A method for preparing a microsphere-foamed thermoplastic elastomer roll material as described in any one of claims 1-9, characterized in that, Includes the following steps: (1) Styrene-based thermoplastic elastomer, styrene-butadiene-glycidyl methacrylate copolymer, ethylene-vinyl acetate, maleic anhydride-grafted EVA, talc, antioxidant and plasticizer are mixed evenly and recorded as mixture 1; (2) The thermal expansion microsphere foaming agent and the silane coupling agent are mixed and reacted to obtain mixture 2; (3) Mixture 1, mixture 2 and cis-oil-based primary amine are mixed and then extruded. The extrusion temperature is 130~150℃ in the first section and 170~200℃ in the second section to obtain a uniform pore melt. (4) The foam melt is extruded and cooled to obtain the microsphere foamed thermoplastic elastomer roll.