A micro-crosslinked TPE composite material for airless tire and preparation method thereof

Abstract

The invention discloses a micro-crosslinked TPE composite material for a pneumatic-free tire and a preparation method thereof, and relates to the technical field of polymer material processing. The micro-crosslinked TPE composite material for a pneumatic-free tire comprises the following raw materials: 5-10 parts of block copolymerized polypropylene, 8-15 parts of PE-RT resin, 20-40 parts of high molecular weight SEBS, 20-30 parts of environmentally friendly paraffin oil, 5-10 parts of styrene-maleic anhydride copolymer, 5-15 parts of polyphenylene ether powder resin, 5-15 parts of carbon nanotubes, 0.5-1.5 parts of ultra-high molecular weight silicone masterbatch, and 0.1-0.5 parts of an anti-aging agent; the preparation method comprises the following steps: S1: high molecular weight SEBS absorbs white oil; S2, raw material mixing and kneading to prepare agglomerated semi-plasticized material; S3, extrusion granulation to prepare the micro-crosslinked TPE composite material; the TPE composite material prepared by the invention has good heat resistance and thermal conductivity, significantly improves the service life of the pneumatic-free tire, forms a heat conductive network in the material system, and improves the tear strength and heat resistance of the TPE composite material.

Description

Technical Field

[0001] The invention relates to the field of polymer material processing technology, in particular to a micro-crosslinked TPE composite material for airless tires and a preparation method thereof. Background Art

[0002] Pneumatic tires have been widely used in shared electric motorcycles, electric balance bikes, and electric sanitation vehicles in recent years because of their advantages such as simple production, puncture resistance, and shock absorption. Pneumatic tires can be divided into solid tires and open structure tires by structure. Open structure tires are made of open structure and tube-shaped staggered three-dimensional shock absorption. Compared with solid tires, they have the advantages of beautiful appearance and light weight. Because the open structure has more open tubes, the car uses the continuous deformation-recovery process of the open tube to obtain buffering and shock absorption during driving.

[0003] At present, the materials for airless tires that are directly injected are mainly thermoplastic elastomers TPE and thermoplastic polyurethane TPU. Thermoplastic elastomer TPE materials have the advantages of fast molding, wide processing window, light specific gravity, and low price. TPE materials are increasingly widely used in airless tires. Research on airless tire TPE has always focused on improving the wear resistance and heat resistance of materials. However, in actual applications and extreme damage tests on tires, we found that in the continuous driving of open tires, especially in an environment with obstacles, if the tire material has insufficient tear resistance, heat resistance, and fatigue resistance, tear lines are likely to appear in the force-bearing part of the empty tube wall support, which greatly reduces the collapse mileage of the tire. At the same time, during the simulation test, through continuous detection of the tire material and temperature in time, we found that the tire temperature will gradually increase in the initial stage, and finally reach a dynamic balance with the ambient temperature. The final dynamic equilibrium temperature of the tire is related to the ambient temperature and the thermal conductivity of the tire material. If the tire temperature is too high, for thermoplastic materials, it may cause partial softening of the tire material, and the tear strength, wear resistance, and support of the material will be significantly reduced. Because we cannot control the ambient temperature of airless tire products in actual applications, the thermal conductivity of the tire material determines the dynamic equilibrium temperature of the material in the final use. If the thermal conductivity is good, the tire material can conduct the continuously generated heat in time, and the dynamic equilibrium temperature will be significantly lower.

[0004] Research on TPE materials for airless tires has been going on for many years. The invention patent with application number 201711108310.5 only improves the wear resistance of the material by adding wear-resistant agents to the ordinary TPE formula, but does not pay attention to the fatigue resistance, heat resistance and thermal conductivity of the material in practical applications; the invention patent with application number 201510361760.X focuses on the fatigue resistance and temperature resistance of the material, and improves the fatigue resistance and temperature resistance of the material by adding ultra-high molecular weight styrene elastomer and polyphenylene ether to the formula. However, ultra-high molecular weight styrene elastomer will make the material difficult to process and difficult to injection mold. At the same time, the material has not undergone micro-crosslinking, and the tear resistance and fatigue resistance cannot be further improved. , the thermal conductivity of the material is poor; the invention patent with application number 201810964235.0 improves the wear resistance of the material by adding Lubmer and high molecular weight silicone masterbatch into the formula, but Lubmer resin is a self-lubricating resin with a low friction coefficient. Here, the friction coefficient of the material surface is reduced by adding Lubmer resin with a low friction coefficient, thereby improving the wear resistance of the entire material. However, this will lead to a decrease in the anti-skid property of the tire, especially on wet roads. Braking will increase the risk of collision accidents. At the same time, the material provided by the patent has poor heat resistance and thermal conductivity; in view of this situation, there is an urgent need to develop a micro-cross-linked TPE composite material for airless tires and a preparation method thereof to meet the needs of actual use. Summary of the invention

[0005] In view of this, the present invention aims at the deficiencies in the prior art, and its main purpose is to provide a micro-cross-linked TPE composite material for airless tires and a preparation method thereof. The TPE composite material prepared by the present invention has good heat resistance and thermal conductivity, significantly improves the service life of airless tires, forms a thermal conductive network in the material system, and improves the tear strength and heat resistance of the TPE composite material.

[0006] To achieve the above purpose, the present invention adopts the following technical solutions:

[0007] A slightly cross-linked TPE composite material for a pneumatic-free tire comprises the following raw materials, measured by weight: 5-10 parts of block copolymer polypropylene, 8-15 parts of PE-RT resin, 20-40 parts of high molecular weight SEBS, 20-30 parts of environmentally friendly paraffin oil, 5-10 parts of styrene-maleic anhydride copolymer, 5-15 parts of polyphenylene ether powder resin, 5-15 parts of carbon nanotubes, 0.5-1.5 parts of ultra-high molecular weight silicone masterbatch, and 0.1-0.5 parts of an anti-aging agent.

[0008] As a preferred solution: the block copolymer polypropylene is a medium-high molecular weight block copolymer polypropylene, the melt index range is 1-3g / 10min, and the test conditions are 230°C and 2.16kg.

[0009] The block copolymer polypropylene with a melt index of 1-3g / 10min has a longer molecular weight and can form a good entanglement with other polymer molecular chains, thereby improving the material's resistance to fatigue cracking. The regular block structure of the molecular chain ensures the high crystallinity and heat resistance of the polypropylene material. At the same time, the block copolymer insertion of ethylene units in the molecule improves the material's fatigue resistance and impact resistance.

[0010] As a preferred solution: the melt index range of the PE-RT resin is 0.5-2g / 10min, and the test conditions are 190°C and 2.16kg.

[0011] PE-TR resin is a medium-density polyethylene produced by special molecular design and synthesis process. It adopts the method of copolymerization of ethylene and octene to obtain a unique molecular structure by controlling the number and distribution of side chains to improve the heat resistance of PE. The material has both good flexibility and good heat resistance of polyethylene. Therefore, adding some heat-resistant PE-RT resin helps to maintain the flexibility of the material while improving the heat resistance of the material.

[0012] As a preferred solution: the high molecular weight SEBS is a SEBS material with a styrene content of 35%-50% and a molecular weight of 120,000-150,000.

[0013] High molecular weight SEBS has higher heat resistance. At the same time, high styrene content can form more physical cross-linking points together with polyphenylene ether resin and styrene-maleic anhydride copolymer, thereby improving the heat resistance of the material.

[0014] As a preferred solution: the maleic anhydride content in the styrene-maleic anhydride copolymer is 5%-30%.

[0015] The structural formula of the styrene-maleic anhydride copolymer is as follows, wherein x / y is 0.7-0.95, and n is 1000-3000.

[0016]

[0017] Styrene-maleic anhydride copolymer has good compatibility with SEBS and polyphenylene ether resin. At the same time, the active maleic anhydride group can partially undergo ring-opening grafting reaction with polypropylene and polyethylene during melt processing to form chemical cross-linking points. Although the heat resistance of the formed micro-cross-linked thermoplastic elastomer TPE material cannot be comparable to that of fully vulcanized rubber, compared with linear non-cross-linked materials, the Vicat softening point and tear strength of the material are significantly improved. In practical applications, the heat resistance and fatigue resistance of the material are also significantly improved.

[0018] As a preferred solution: the polyphenylene ether powder resin is obtained by crushing PPO resin with a pulverizer and then passing it through a 150-200 mesh sieve. The model of the polyphenylene ether powder resin is one or a mixture of PPO LXR035, PPO LXR040, and PPOLXR045 of Bluestar Chemical.

[0019] Polyphenylene ether, SEBS materials and styrene-maleic anhydride copolymer all contain benzene ring structures, which can form physical cross-linking points during melt processing, thereby improving the heat resistance of the material.

[0020] As a preferred solution: the carbon nanotubes are multi-walled carbon nanotubes, the diameter of the carbon nanotubes is 10-30 nm, and the length of the carbon nanotubes is 2-10 um.

[0021] The thermal conductivity of carbon nanotubes can reach 3500W / m·K, and multi-walled carbon nanotubes are more likely to form a network structure in polymer molecules. A lower addition amount can give the composite material better thermal conductivity. At the same time, multi-walled carbon nanotubes play a reinforcing role in TPE materials, improving the heat resistance and wear resistance of the material.

[0022] As a preferred solution: the organosilicon in the ultra-high molecular weight silicone masterbatch is a linear ultra-high molecular weight hydroxyl-terminated polydimethylsiloxane, wherein the molecular weight is 600,000-1.2 million.

[0023] Ultra-high molecular weight silicone masterbatch has good internal and external lubrication, and can provide the material with good processing performance and injection molding demolding properties.

[0024] The method for preparing a micro-crosslinked TPE composite material for a pneumatic-free tire comprises the following steps:

[0025] S1: High molecular weight SEBS absorbs white oil: Weigh 5-10 parts of block copolymer polypropylene, 8-15 parts of PE-RT resin, 20-40 parts of high molecular weight SEBS, 20-30 parts of environmentally friendly paraffin oil, 5-10 parts of styrene-maleic anhydride copolymer, 5-15 parts of polyphenylene ether powder resin, 5-15 parts of carbon nanotubes, 0.5-1.5 parts of ultra-high molecular weight silicone masterbatch, and 0.1-0.5 parts of anti-aging agent respectively, add high molecular weight SEBS and white oil into a high-speed mixer to mix and form high molecular weight SEBS foaming oil material, and let it stand for more than 4 hours to allow the high molecular weight SEBS to fully absorb the white oil.

[0026] S2. Mixing raw materials to prepare agglomerated semi-plasticized material: preheat an internal mixer, and then put high molecular weight SEBS foam oil material and weighed block copolymer polypropylene, PE-RT resin, environmentally friendly paraffin oil, styrene-maleic anhydride copolymer, polyphenylene ether powder resin, carbon nanotubes, ultra-high molecular weight silicone masterbatch, and antioxidant into the internal mixer and mix for 10-20 minutes to obtain agglomerated semi-plasticized material.

[0027] S3. Preparation of micro-cross-linked TPE composite material by extrusion granulation: Add the lumpy semi-plasticized material to a conical double forced feeder, feed it to a twin-screw extruder through the conical double forced feeder, extrude and granulate it through the twin-screw extruder, and then cut and dry it to obtain a micro-cross-linked TPE composite material for airless tires; the temperature of the twin-screw extruder is: 150℃-160℃ in the feeding section, 180℃-200℃ in the conveying section, 190℃-210℃ in the melting section, 160℃-200℃ in the die head, and the speed of the twin-screw main engine is 300-450r / min.

[0028] The present invention first mixes the materials through an internal mixer for pre-plasticization, which can effectively disperse the thermal conductive multi-walled carbon nanotubes therein, thereby preventing the multi-walled carbon nanotubes that have not been pre-plasticized and dispersed from directly entering the twin-screw processing, causing the carbon nanotubes to agglomerate and break under the shearing of the twin-screw, thereby losing the effect of serving as a thermal conductive network.

[0029] As a preferred solution: in step S1, high molecular weight SEBS and white oil are added into a high-speed mixer and mixed at a speed of 200-400 r / min; in step S2, the preheating temperature of the internal mixer is 140°C-170°C.

[0030] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical solution that:

[0031] First, the present invention reasonably mixes block copolymer polypropylene with higher fatigue resistance and PE-RT resin with excellent heat resistance, thereby improving the fatigue resistance and heat resistance of the material itself.

[0032] Second, the present invention reasonably mixes high molecular weight SEBS, polyphenylene ether powder resin, and styrene-maleic anhydride copolymer. High molecular weight SEBS has better heat resistance and better compatibility with PPO powder resin. At the same time, the physical cross-linking points formed by the shared benzene ring structure significantly improve the heat resistance of the material.

[0033] Third, the styrene-maleic anhydride copolymer used in the present invention can form chemical crosslinking points with other resins during the melt processing, and the formed micro-crosslinked thermoplastic elastomer TPE material has thermoplasticity, and the Vicat softening point and tear strength of the material are significantly improved. In practical applications, the heat resistance and fatigue resistance of the material are also significantly improved.

[0034] Fourthly, the multi-walled carbon nanotubes of the present invention have a thermal conductivity of up to 3500 W / mK, and have the characteristics of high thermal conductivity and relatively low price. By utilizing the characteristics of multi-walled tubular shapes, a relatively low addition amount can form a better thermal conductive network, giving the material a better thermal conductive effect.

[0035] Fifth, the present invention first disperses the multi-walled carbon nanotubes uniformly in the resin to form a semi-plasticized material by mixing in an internal mixer with low shear, and then feeds the agglomerated semi-plasticized material into a twin-screw processing through a conical double feeder, thereby avoiding the agglomeration of carbon nanotubes and the breakage of the multi-walled tube structure. DETAILED DESCRIPTION

[0036] The invention provides a micro-crosslinked TPE composite material for a pneumatic-free tire. The composite material comprises the following raw materials in parts by weight: 5-10 parts of block copolymerized polypropylene, 8-15 parts of PE-RT resin, 20-40 parts of high molecular weight SEBS, 20-30 parts of environmentally friendly paraffin oil, 5-10 parts of styrene-maleic anhydride copolymer, 5-15 parts of polyphenylene ether powder resin, 5-15 parts of carbon nanotubes, 0.5-1.5 parts of ultra-high molecular weight silicone masterbatch and 0.1-0.5 parts of an anti-aging agent.

[0037] The block copolymer polypropylene is a medium-high molecular weight block copolymer polypropylene, with a melting point range of 1-3g / 10min, and the test conditions are 230°C and 2.16kg; the melting point range of the PE-RT resin is 0.5-2g / 10min, and the test conditions are 190°C and 2.16kg; the high molecular weight SEBS is a SEBS material with a styrene content of 35%-50% and a molecular weight of 120,000-150,000; the maleic anhydride content in the styrene-maleic anhydride copolymer is 5%-30%; the polyphenylene ether powder resin is obtained by crushing the PPO resin with a pulverizer and then passing through a 150-200 mesh sieve, and the models of the polyphenylene ether powder resin are PPO LXR035, PPO LXR040, PPO One or more mixtures of LXR045; the carbon nanotubes are multi-walled carbon nanotubes, the diameter of the carbon nanotubes is 10-30nm, and the length of the carbon nanotubes is 2-10um; the organosilicon in the ultra-high molecular weight silicone masterbatch is linear ultra-high molecular weight hydroxyl-terminated polydimethylsiloxane, wherein the molecular weight is 600,000-1.2 million.

[0038] The raw materials used in Examples 1 to 5 and Comparative Examples 1 to 4 are described in detail below. The others not described are all common raw materials on the market. The block copolymer polypropylene is Maoming Petrochemical PPB M02; the PE-RT resin is Qilu Petrochemical QHM22F; the high molecular weight SEBS is Asahi Kasei Tuftec H1051; the conventional SEBS is Yuehua SEBS 604T; the environmentally friendly paraffin oil is Formosa Plastics 500N model base oil; the styrene-maleic anhydride copolymer is French Crayville SMA2000; the polyphenylene ether powder resin is Bluestar Chemical PPO LXR040; the carbon nanotube is Shandong Dazhan Nanomaterials Co., Ltd.'s multi-walled carbon nanotube CP-3003; the ultra-high molecular weight silicone masterbatch is Wacker Pellet S.

[0039] Example 1

[0040] In this embodiment, a method for preparing a micro-crosslinked TPE composite material for a pneumatic-free tire comprises the following steps:

[0041] S1: High molecular weight SEBS absorbing white oil: According to the weight parts shown in Table 1 below, weigh 8 parts of block copolymer polypropylene PPB M02, 10 parts of PE-RT resin QHM22F, 27 parts of environmentally friendly paraffin oil 500N, 32 parts of high molecular weight SEBS H1051, 7 parts of polyphenylene ether powder resin PPO LXR040, 7 parts of styrene-maleic anhydride copolymer SMA2000, 8 parts of multi-walled carbon nanotubes CP-3003, and 1 part of silicone masterbatch. Pellet S, 0.2 parts of antioxidant 1010 and 0.1 parts of antioxidant 168, high molecular weight SEBS and environmentally friendly paraffin oil are added into a high-speed mixer, mixed at 400r / min for 4 minutes to form a high molecular weight SEBS foaming oil material, and left to stand for 5 hours to allow the high molecular weight SEBS to fully absorb the white oil.

[0042] S2. Mixing the raw materials to prepare agglomerated semi-plasticized material: preheat an internal mixer to 160° C., and then put the high molecular weight SEBS foam oil material and the weighed block copolymer polypropylene, PE-RT resin, environmentally friendly paraffin oil, styrene-maleic anhydride copolymer, polyphenylene ether powder resin, carbon nanotubes, ultra-high molecular weight silicone masterbatch, and antioxidant into the internal mixer and mix for 15 minutes to obtain agglomerated semi-plasticized material.

[0043] S3. Preparation of micro-cross-linked TPE composite material by extrusion granulation: Add the lumpy semi-plasticized material to a conical double forced feeder, and feed it to a twin-screw extruder by the conical double forced feeder. The temperature of the twin-screw extruder is: 150°C in the feeding section, 190°C in the conveying section, 210°C in the melting section, 180°C in the die head, and the speed of the twin-screw main engine is 400r / min; extrude and granulate the material through a twin-screw extruder, and then cut and dry the material to obtain a micro-cross-linked TPE composite material for airless tires.

[0044] Example 2

[0045] In this embodiment, a method for preparing a micro-crosslinked TPE composite material for a pneumatic-free tire comprises the following steps:

[0046] S1: high molecular weight SEBS absorbing white oil: according to the weight parts shown in Table 1 below, weigh 10 parts of block copolymer polypropylene PPB M02, 8 parts of PE-RT resin QHM22F, 28 parts of environmentally friendly paraffin oil 500N, 31 parts of high molecular weight SEBS H1051, 8 parts of polyphenylene ether powder resin PPO LXR040, 6 parts of styrene-maleic anhydride copolymer SMA2000, 7 parts of multi-walled carbon nanotube CP-3003, and 0.8 parts of silicone masterbatch. Pellet S, 0.1 parts of antioxidant 1010 and 0.1 parts of antioxidant 168, high molecular weight SEBS and environmentally friendly paraffin oil are added into a high-speed mixer, mixed at 400r / min for 4 minutes to form a high molecular weight SEBS foaming oil material, and left to stand for 5 hours to allow the high molecular weight SEBS to fully absorb the white oil.

[0047] S2. Mixing the raw materials to prepare agglomerated semi-plasticized material: preheat an internal mixer to 160° C., and then put the high molecular weight SEBS foam oil material and the weighed block copolymer polypropylene, PE-RT resin, environmentally friendly paraffin oil, styrene-maleic anhydride copolymer, polyphenylene ether powder resin, carbon nanotubes, ultra-high molecular weight silicone masterbatch, and antioxidant into the internal mixer and mix for 15 minutes to obtain agglomerated semi-plasticized material.

[0048] S3. Preparation of micro-cross-linked TPE composite material by extrusion granulation: Add the lumpy semi-plasticized material to a conical double forced feeder, and feed it to a twin-screw extruder by the conical double forced feeder. The temperature of the twin-screw extruder is: 150°C in the feeding section, 190°C in the conveying section, 210°C in the melting section, 180°C in the die head, and the speed of the twin-screw main engine is 400r / min; extrude and granulate the material through a twin-screw extruder, and then cut and dry the material to obtain a micro-cross-linked TPE composite material for airless tires.

[0049] Example 3

[0050] In this embodiment, a method for preparing a micro-crosslinked TPE composite material for a pneumatic-free tire comprises the following steps:

[0051] S1: high molecular weight SEBS absorbing white oil: according to the weight parts shown in Table 1 below, weigh 9 parts of block copolymer polypropylene PPB M02, 9 parts of PE-RT resin QHM22F, 28 parts of environmentally friendly paraffin oil 500N, 33 parts of high molecular weight SEBS H1051, 7 parts of polyphenylene ether powder resin PPO LXR040, 7 parts of styrene-maleic anhydride copolymer SMA2000, 7 parts of multi-walled carbon nanotube CP-3003, and 0.9 parts of silicone masterbatch. Pellet S, 0.2 parts of antioxidant 1010 and 0.1 parts of antioxidant 168, high molecular weight SEBS and environmentally friendly paraffin oil are added into a high-speed mixer, mixed at 400r / min for 4 minutes to form a high molecular weight SEBS foaming oil material, and left to stand for 5 hours to allow the high molecular weight SEBS to fully absorb the white oil.

[0052] S2. Mixing the raw materials to prepare agglomerated semi-plasticized material: preheat an internal mixer to 160° C., and then put the high molecular weight SEBS foam oil material and the weighed block copolymer polypropylene, PE-RT resin, environmentally friendly paraffin oil, styrene-maleic anhydride copolymer, polyphenylene ether powder resin, carbon nanotubes, ultra-high molecular weight silicone masterbatch, and antioxidant into the internal mixer and mix for 15 minutes to obtain agglomerated semi-plasticized material.

[0053] S3. Preparation of micro-cross-linked TPE composite material by extrusion granulation: Add the lumpy semi-plasticized material to a conical double forced feeder, and feed it to a twin-screw extruder by the conical double forced feeder. The temperature of the twin-screw extruder is: 150°C in the feeding section, 190°C in the conveying section, 210°C in the melting section, 180°C in the die head, and the speed of the twin-screw main engine is 400r / min; extrude and granulate the material through a twin-screw extruder, and then cut and dry the material to obtain a micro-cross-linked TPE composite material for airless tires.

[0054] Example 4

[0055] In this embodiment, a method for preparing a micro-crosslinked TPE composite material for a pneumatic-free tire comprises the following steps:

[0056] S1: high molecular weight SEBS absorbing white oil: according to the weight parts shown in Table 1 below, weigh 8 parts of block copolymer polypropylene PPB M02, 8 parts of PE-RT resin QHM22F, 27 parts of environmentally friendly paraffin oil 500N, 33 parts of high molecular weight SEBS H1051, 8 parts of polyphenylene ether powder resin PPO LXR040, 7 parts of styrene-maleic anhydride copolymer SMA2000, 7 parts of multi-walled carbon nanotubes CP-3003, and 1.2 parts of silicone masterbatch. Pellet S, 0.15 parts of antioxidant 1010 and 0.15 parts of antioxidant 168, high molecular weight SEBS and environmentally friendly paraffin oil are added into a high-speed mixer, mixed at 400r / min for 4 minutes to form a high molecular weight SEBS foam oil material, and left to stand for 5 hours to allow the high molecular weight SEBS to fully absorb the white oil.

[0057] S2. Mixing the raw materials to prepare agglomerated semi-plasticized material: preheat an internal mixer to 160° C., and then put the high molecular weight SEBS foam oil material and the weighed block copolymer polypropylene, PE-RT resin, environmentally friendly paraffin oil, styrene-maleic anhydride copolymer, polyphenylene ether powder resin, carbon nanotubes, ultra-high molecular weight silicone masterbatch, and antioxidant into the internal mixer and mix for 15 minutes to obtain agglomerated semi-plasticized material.

[0058] S3. Preparation of micro-cross-linked TPE composite material by extrusion granulation: Add the lumpy semi-plasticized material to a conical double forced feeder, and feed it to a twin-screw extruder by the conical double forced feeder. The temperature of the twin-screw extruder is: 150°C in the feeding section, 190°C in the conveying section, 210°C in the melting section, 180°C in the die head, and the speed of the twin-screw main engine is 400r / min; extrude and granulate the material through a twin-screw extruder, and then cut and dry the material to obtain a micro-cross-linked TPE composite material for airless tires.

[0059] Example 5

[0060] In this embodiment, a method for preparing a micro-crosslinked TPE composite material for a pneumatic-free tire comprises the following steps:

[0061] S1: high molecular weight SEBS absorbing white oil: according to the weight parts shown in Table 1 below, weigh 8 parts of block copolymer polypropylene PPB M02, 12 parts of PE-RT resin QHM22F, 29 parts of environmentally friendly paraffin oil 500N, 31 parts of high molecular weight SEBS H1051, 6 parts of polyphenylene ether powder resin PPO LXR040, 7 parts of styrene-maleic anhydride copolymer SMA2000, 7 parts of multi-walled carbon nanotube CP-3003, and 1.1 parts of silicone masterbatch. Pellet S, 0.2 parts of antioxidant 1010 and 0.1 parts of antioxidant 168, high molecular weight SEBS and environmentally friendly paraffin oil are added into a high-speed mixer, mixed at 400r / min for 4 minutes to form a high molecular weight SEBS foaming oil material, and left to stand for 5 hours to allow the high molecular weight SEBS to fully absorb the white oil.

[0062] S2. Mixing the raw materials to prepare agglomerated semi-plasticized material: preheat an internal mixer to 160° C., and then put the high molecular weight SEBS foam oil material and the weighed block copolymer polypropylene, PE-RT resin, environmentally friendly paraffin oil, styrene-maleic anhydride copolymer, polyphenylene ether powder resin, carbon nanotubes, ultra-high molecular weight silicone masterbatch, and antioxidant into the internal mixer and mix for 15 minutes to obtain agglomerated semi-plasticized material.

[0063] S3. Preparation of micro-cross-linked TPE composite material by extrusion granulation: Add the lumpy semi-plasticized material to a conical double forced feeder, and feed it to a twin-screw extruder by the conical double forced feeder. The temperature of the twin-screw extruder is: 150°C in the feeding section, 190°C in the conveying section, 210°C in the melting section, 180°C in the die head, and the speed of the twin-screw main engine is 400r / min; extrude and granulate the material through a twin-screw extruder, and then cut and dry the material to obtain a micro-cross-linked TPE composite material for airless tires.

[0064] Comparative Example 1

[0065] A method for preparing a composite material in this comparative example comprises the following steps:

[0066] S1: Conventional SEBS absorbing white oil: According to the weight parts shown in Table 1 below, 8 parts of block copolymer polypropylene PPB M02, 10 parts of PE-RT resin QHM22F, 27 parts of environmentally friendly paraffin oil 500N, 32 parts of conventional SEBS H1051, 7 parts of polyphenylene ether powder resin PPO LXR040, 7 parts of styrene-maleic anhydride copolymer SMA2000, 8 parts of multi-walled carbon nanotubes CP-3003, and 1 part of silicone masterbatch were weighed. Pellet S, 0.2 parts of antioxidant 1010 and 0.1 parts of antioxidant 168, conventional SEBS and environmentally friendly paraffin oil are added into a high-speed mixer, mixed at 400r / min for 4 minutes to form a conventional SEBS foaming oil material, and left to stand for 5 hours to allow the conventional SEBS to fully absorb the white oil.

[0067] S2. Mixing the raw materials to prepare agglomerated semi-plasticized material: preheat an internal mixer to 160° C., and then put conventional SEBS foam oil material and weighed block copolymer polypropylene, PE-RT resin, environmentally friendly paraffin oil, styrene-maleic anhydride copolymer, polyphenylene ether powder resin, carbon nanotubes, ultra-high molecular weight silicone masterbatch, and antioxidant into an internal mixer and mix for 15 minutes to obtain agglomerated semi-plasticized material.

[0068] S3. Preparation of micro-cross-linked TPE composite materials by extrusion granulation: add the lumpy semi-plasticized material to a conical double forced feeder, which feeds the material to a twin-screw extruder. The temperature of the twin-screw extruder is: 150°C in the feeding section, 190°C in the conveying section, 210°C in the melting section, 180°C in the die head, and the speed of the twin-screw main engine is 400r / min. The composite material is obtained by extrusion granulation through a twin-screw extruder, and then pelletizing and drying.

[0069] Comparative Example 2

[0070] A method for preparing a composite material in this comparative example comprises the following steps:

[0071] S1: High molecular weight SEBS absorbing white oil: According to the weight parts shown in Table 1 below, weigh 10 parts of block copolymer polypropylene PPB M02, 11 parts of PE-RT resin QHM22F, 29 parts of environmentally friendly paraffin oil 500N, 33 parts of high molecular weight SEBS H1051, 8 parts of polyphenylene ether powder resin PPO LXR040, 7 parts of multi-walled carbon nanotube CP-3003, and 0.8 parts of silicone masterbatch. Pellet S, 0.1 parts of antioxidant 1010 and 0.1 parts of antioxidant 168, high molecular weight SEBS and environmentally friendly paraffin oil are added into a high-speed mixer, mixed at 400r / min for 4 minutes to form a high molecular weight SEBS foaming oil material, and left to stand for 5 hours to allow the high molecular weight SEBS to fully absorb the white oil.

[0072] S2. Mixing the raw materials to prepare agglomerated semi-plasticized material: preheat an internal mixer to 160° C., and then put the high molecular weight SEBS foam oil material and the weighed block copolymer polypropylene, PE-RT resin, environmentally friendly paraffin oil, polyphenylene ether powder resin, carbon nanotubes, ultra-high molecular weight silicone masterbatch, and antioxidant into the internal mixer and mix for 15 minutes to obtain agglomerated semi-plasticized material.

[0073] S3. Preparation of micro-cross-linked TPE composite materials by extrusion granulation: add the lumpy semi-plasticized material to a conical double forced feeder, which feeds the material to a twin-screw extruder. The temperature of the twin-screw extruder is: 150°C in the feeding section, 190°C in the conveying section, 210°C in the melting section, 180°C in the die head, and the speed of the twin-screw main engine is 400r / min. The composite material is obtained by extrusion granulation through a twin-screw extruder, and then pelletizing and drying.

[0074] Comparative Example 3

[0075] A method for preparing a composite material in this comparative example comprises the following steps:

[0076] S1: High molecular weight SEBS absorbing white oil: According to the weight parts shown in Table 1 below, weigh 10 parts of block copolymer polypropylene PPB M02, 10 parts of PE-RT resin QHM22F, 30 parts of environmentally friendly paraffin oil 500N, 35 parts of high molecular weight SEBS H1051, 8 parts of polyphenylene ether powder resin PPO LXR040, 7 parts of styrene-maleic anhydride copolymer SMA2000, and 0.9 parts of silicone masterbatch. Pellet S, 0.2 parts of antioxidant 1010 and 0.1 parts of antioxidant 168, high molecular weight SEBS and environmentally friendly paraffin oil are added into a high-speed mixer, mixed at 400r / min for 4 minutes to form a high molecular weight SEBS foaming oil material, and left to stand for 5 hours to allow the high molecular weight SEBS to fully absorb the white oil.

[0077] S2. Mixing the raw materials to prepare agglomerated semi-plasticized material: preheat an internal mixer to 160° C., and then put the high molecular weight SEBS foam oil material and the weighed block copolymer polypropylene, PE-RT resin, environmentally friendly paraffin oil, styrene-maleic anhydride copolymer, polyphenylene ether powder resin, ultra-high molecular weight silicone masterbatch, and antioxidant into the internal mixer and mix for 15 minutes to obtain agglomerated semi-plasticized material.

[0078] S3. Preparation of micro-cross-linked TPE composite materials by extrusion granulation: add the lumpy semi-plasticized material to a conical double forced feeder, which feeds the material to a twin-screw extruder. The temperature of the twin-screw extruder is: 150°C in the feeding section, 190°C in the conveying section, 210°C in the melting section, 180°C in the die head, and the speed of the twin-screw main engine is 400r / min. The composite material is obtained by extrusion granulation through a twin-screw extruder, and then pelletizing and drying.

[0079] Comparative Example 4

[0080] A method for preparing a composite material in this comparative example comprises the following steps:

[0081] S1: High molecular weight SEBS absorbing white oil: According to the weight parts shown in Table 1 below, weigh 9 parts of block copolymer polypropylene PPB M02, 9 parts of PE-RT resin QHM22F, 30 parts of environmentally friendly paraffin oil 500N, 35 parts of high molecular weight SEBS H1051, 8 parts of styrene-maleic anhydride copolymer SMA2000, 8 parts of multi-walled carbon nanotubes CP-3003, and 1.2 parts of silicone masterbatch. Pellet S, 0.15 parts of antioxidant 1010 and 0.15 parts of antioxidant 168, high molecular weight SEBS and environmentally friendly paraffin oil are added into a high-speed mixer, mixed at 400r / min for 4 minutes to form a high molecular weight SEBS foam oil material, and left to stand for 5 hours to allow the high molecular weight SEBS to fully absorb the white oil.

[0082] S2. Mixing the raw materials to prepare agglomerated semi-plasticized material: preheat an internal mixer to 160° C., and then put the high molecular weight SEBS foam oil material and the weighed block copolymer polypropylene, PE-RT resin, environmentally friendly paraffin oil, styrene-maleic anhydride copolymer, carbon nanotubes, ultra-high molecular weight silicone masterbatch, and antioxidant into the internal mixer and mix for 15 minutes to obtain agglomerated semi-plasticized material.

[0083] S3. Preparation of micro-cross-linked TPE composite materials by extrusion granulation: add the lumpy semi-plasticized material to a conical double forced feeder, which feeds the material to a twin-screw extruder. The temperature of the twin-screw extruder is: 150°C in the feeding section, 190°C in the conveying section, 210°C in the melting section, 180°C in the die head, and the speed of the twin-screw main engine is 400r / min. The composite material is obtained by extrusion granulation through a twin-screw extruder, and then pelletizing and drying.

[0084] The contents of the components in Examples 2-5 and Comparative Examples 1-4 are shown in Table 1. Except for the differences in the types and ratios of raw materials, the preparation methods are the same as those in Example 1. Comparative Example 1 replaces the high molecular weight SEBS with conventional SEBS on the basis of Example 1, Comparative Example 2 does not add styrene-maleic anhydride copolymer, Comparative Example 3 does not add carbon nanotubes, and Comparative Example 4 does not add polyphenylene ether powder resin.

[0085] Table 1: Raw material compositions of Examples 1-5 and Comparative Examples 1-4.

[0086]

[0087]

[0088] Effect Example

[0089] Various performance tests were performed on the slightly cross-linked TPE composite materials for airless tires prepared in Examples 1-5 and Comparative Examples 1-4. The materials prepared in Examples 1-5 and Comparative Examples 1-4 were injection molded into finished airless tires, and tire destruction tests were performed according to GB / T 31548-2015 and HG / T2906-2017 standards. The specific test conditions were: the tire was loaded with 200 kg, the running speed was 30 km / h, and the tire passed through two obstacles with a width of 5 mm and a height of 10 mm per lap. The results are shown in Table 2.

[0090] Table 2: Performance test results of Examples 1-5 and Comparative Examples 1-4:

[0091]

[0092]

[0093] Through the test results of the above embodiments and comparative examples, it can be seen that the micro-crosslinked TPE composite materials for airless tires prepared in embodiments 1-5 have high tear strength, good heat resistance and thermal conductivity, and various comprehensive properties meet the requirements of airless tires; Comparative Example 1 replaces the high molecular weight SEBS with conventional SEBS on the basis of Example 1, and the SEBS with low styrene content has low heat resistance, and the physical crosslinking points with polyphenylene ether resin and styrene-maleic anhydride copolymer are weak, the Vicat softening point and tear strength of the TPE composite material are slightly reduced, and the tire damage test mileage is reduced; Comparative Example 2 No styrene-maleic anhydride copolymer was added, and the material could not form chemical micro-crosslinking during the processing, the heat resistance and tear strength of the material were significantly reduced, and the tire destruction test mileage was significantly reduced; Comparative Example 3 did not add carbon nanotubes, due to the loss of thermal conductivity and reinforcement of carbon nanotubes, the tear strength and Vicat softening point of the material were partially reduced, the thermal conductivity of the material was greatly reduced, the tire destruction test mileage decreased the most, and the temperature increased significantly when it collapsed; Comparative Example 4 did not add polyphenylene ether powder resin, the material could not form an effective physical crosslinking point effect, the Vicat softening point decreased significantly, and the tire destruction test mileage also decreased significantly.

[0094] The above description is only a preferred embodiment of the present invention and does not limit the technical scope of the present invention. Therefore, any slight modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A micro-crosslinked TPE composite material for a pneumatic tire, characterized in that; Calculated by weight, the raw materials include: 5-10 parts of block copolymer polypropylene, 8-15 parts of PE-RT resin, 20-40 parts of high molecular weight SEBS, 20-30 parts of environmentally friendly paraffin oil, 5-10 parts of styrene-maleic anhydride copolymer, 5-15 parts of polyphenylene ether powder resin, 5-15 parts of carbon nanotubes, 0.5-1.5 parts of ultra-high molecular weight silicone masterbatch, and 0.1-0.5 parts of anti-aging agent; the high molecular weight SEBS has a molecular weight of 120,000-150,000.

2. A slightly cross-linked TPE composite material for a pneumatic tire according to claim 1, characterized in that: The block copolymer polypropylene is a medium-high molecular weight block copolymer polypropylene, with a melt index range of 1-3 g / 10 min and a test condition of 230° C. and 2.16 kg.

3. The slightly cross-linked TPE composite material for a pneumatic tire according to claim 1, characterized in that: The melt index range of the PE-RT resin is 0.5-2 g / 10 min, and the test conditions are 190° C. and 2.16 kg.

4. The slightly cross-linked TPE composite material for a pneumatic tire according to claim 1, characterized in that: The high molecular weight SEBS is a SEBS material with a styrene content of 35%-50% and a molecular weight of 120,000-150,000.

5. The slightly cross-linked TPE composite material for a pneumatic tire according to claim 1, characterized in that: The content of maleic anhydride in the styrene-maleic anhydride copolymer is 5%-30%.

6. The slightly cross-linked TPE composite material for a pneumatic tire according to claim 1, characterized in that: The polyphenylene ether powder resin is obtained by crushing PPO resin with a crusher and then passing through a 150-200 mesh sieve. The model of the polyphenylene ether powder resin is one of PPO LXR035, PPO LXR040, and PPO LXR045 of Bluestar Chemical or a mixture of several thereof.

7. The slightly cross-linked TPE composite material for a pneumatic tire according to claim 1, characterized in that: The carbon nanotubes are multi-walled carbon nanotubes, the diameter of the carbon nanotubes is 10-30 nm, and the length of the carbon nanotubes is 2-10 um.

8. The slightly cross-linked TPE composite material for a pneumatic tire according to claim 1, characterized in that: The organosilicon in the ultra-high molecular weight silicone masterbatch is linear ultra-high molecular weight hydroxyl-terminated polydimethylsiloxane, wherein the molecular weight is 600,000-1.2 million.

9. A method for preparing a slightly cross-linked TPE composite material for a pneumatic tire according to any one of claims 1 to 8, characterized in that: The steps include: S1: High molecular weight SEBS absorbs white oil: Weigh 5-10 parts of block copolymer polypropylene, 8-15 parts of PE-RT resin, 20-40 parts of high molecular weight SEBS, 20-30 parts of environmentally friendly paraffin oil, 5-10 parts of styrene-maleic anhydride copolymer, 5-15 parts of polyphenylene ether powder resin, 5-15 parts of carbon nanotubes, 0.5-1.5 parts of ultra-high molecular weight silicone masterbatch, and 0.1-0.5 parts of anti-aging agent respectively, add high molecular weight SEBS and white oil into a high-speed mixer to mix and form high molecular weight SEBS foam oil material, and let it stand for more than 4 hours to allow the high molecular weight SEBS to fully absorb the white oil; S2, mixing raw materials to prepare agglomerated semi-plasticized material: preheating an internal mixer, and then putting high molecular weight SEBS foam oil material and weighed block copolymer polypropylene, PE-RT resin, environmentally friendly paraffin oil, styrene-maleic anhydride copolymer, polyphenylene ether powder resin, carbon nanotubes, ultra-high molecular weight silicone masterbatch, and anti-aging agent into an internal mixer and mixing for 10-20 minutes to obtain agglomerated semi-plasticized material; S3. Preparation of micro-cross-linked TPE composite material by extrusion granulation: Add the lumpy semi-plasticized material to a conical double forced feeder, feed it to a twin-screw extruder through the conical double forced feeder, extrude and granulate it through the twin-screw extruder, and then cut and dry it to obtain a micro-cross-linked TPE composite material for airless tires; the temperature of the twin-screw extruder is: 150℃-160℃ in the feeding section, 180℃-200℃ in the conveying section, 190℃-210℃ in the melting section, 160℃-200℃ in the die head, and the speed of the twin-screw main engine is 300-450r / min.

10. The method for preparing a slightly cross-linked TPE composite material for a pneumatic tire according to claim 9, characterized in that: In step S1, high molecular weight SEBS and white oil are added into a high-speed mixer and mixed at a speed of 200-400 r / min. In step S2, the preheating temperature of the internal mixer is 140° C.-170° C.

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