Thermoplastic elastomer material and preparation method thereof as well as liquid cooling pipe and preparation method thereof

Abstract

The invention discloses a thermoplastic elastomer material which comprises a thermoplastic elastomer, compound heat-conducting powder and reinforced plastic. The compound heat-conducting powder is mainly composed of graphene, a small amount of modified ceramic heat-conducting powder is added, and the total filler amount is small, so that the material is excellent in heat-conducting property, and the influence on the insulating property is small; furthermore, the silane coupling agent is adopted to modify the spherical boron nitride and the spherical aluminum oxide, so that the mechanical property and the heat-conducting property of the material can be improved. The compound heat-conducting powder, the thermoplastic elastomer and the reinforced plastic have a synergistic effect, so that the heat-conducting property of the thermoplastic elastomer material is improved, and the mechanical property and the aging resistance of the thermoplastic elastomer material are improved. The thermoplastic elastomer material disclosed by the invention is relatively good in insulating property, heat-conducting property, mechanical property and aging resistance, and has a wide application prospect in the field of liquid cooling charging guns.

Description

Technical Field

[0001] The invention relates to the field of materials, and in particular to a thermoplastic elastomer material. Background Art

[0002] Thermoplastic elastomer (TPE) is a polymer material that has both rubber elasticity and plastic processing properties. It exhibits high elasticity of rubber at room temperature, and can be processed and molded like plastic at high temperature. TPE is divided into styrene, polyolefin, polyurethane, and polyester ether. Styrene mainly includes styrene-butadiene-styrene block copolymer (SBS) and hydrogenated styrene-butadiene-styrene block copolymer (SEBS). SBS is a triblock copolymer formed by anionic polymerization of styrene (Styrene, referred to as S) and butadiene (Butadiene, referred to as B), and has the structure of SBS. SEBS is the hydrogenation product of SBS. By hydrogenating and saturating the butadiene chain segment in SBS, polyethylene (E) and polybutene (B) segments are formed. Therefore, it has better aging resistance, temperature resistance and mechanical properties. However, TPE, like most polymer materials, is a poor conductor of heat, and the simplest and most direct way to improve the thermal conductivity of polymers is to fill them with thermal conductive fillers, such as metal powder, ceramic powder, graphene, etc. However, if the thermal conductive powders are isolated or agglomerated in the resin matrix, they cannot form an effective thermal conductive channel and affect the mechanical and aging properties of the resin itself. Therefore, it is very necessary to provide a thermoplastic elastomer material with good thermal conductivity, mechanical properties and aging properties. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention proposes a thermoplastic elastomer material, aiming to solve the problem that the insulation performance, thermal conductivity, mechanical properties and aging performance of the current TPE material cannot be taken into account at the same time.

[0004] The above object of the present invention is achieved through the following technical solutions:

[0005] In a first aspect of the present invention, a thermoplastic elastomer material is provided. The raw materials of the thermoplastic elastomer material are measured in parts by weight and include:

[0006] Thermoplastic elastomer 70-75 parts,

[0007] Compound thermal conductive powder 25-30 parts,

[0008] Reinforced plastic 15-20 parts,

[0009] The composite thermally conductive powder comprises graphene and modified ceramic thermally conductive powder. In terms of weight percentage, the graphene accounts for 75-80% of the sum of the weight of the graphene and the modified ceramic thermally conductive powder. The modified ceramic thermally conductive powder comprises spherical boron nitride and spherical alumina, and the spherical boron nitride and spherical alumina are modified by a silane coupling agent.

[0010] In some embodiments of the present invention, the thermoplastic elastomer is a hydrogenated styrene-butadiene block copolymer, wherein the styrene block repeating unit accounts for 30-35% and the weight average molecular weight ranges from 5×10 4 -5×10 5 , the melt index is greater than 7g / 10min at 190°C and 2.16kg.

[0011] In some embodiments of the present invention, the reinforced plastic is at least one of isotactic polypropylene with a crystallinity of 60-75% and polyphenylene ether with a weight average molecular weight less than 10,000.

[0012] In some embodiments of the present invention, the weight ratio of the spherical boron nitride to the spherical alumina is (8:1)-(12:1); the particle size range of the spherical boron nitride is 10-20 μm, and the particle size range of the spherical alumina is 80-200 μm.

[0013] In some embodiments of the present invention, the method for preparing the composite thermally conductive powder is as follows:

[0014] The spherical boron nitride and the spherical aluminum oxide powder are weighed and mixed according to the weight ratio, ultrasonically dispersed in an organic solvent 1, filtered, and dried to obtain a powder A.

[0015] The powder A, siloxane coupling agent and organic solvent 2 are mixed in a ratio of 100:(1-5):(200-500) by weight, stirred at 60-75° C. for 40-80 min, heated to 80° C., stirred for 4-8 h, filtered and dried to obtain a powder B;

[0016] Mixing the powder B and the graphene to obtain the composite thermal conductive powder;

[0017] Wherein, the organic solvent 1 is at least one of ethanol, isopropanol, n-propanol, cyclohexanone and acetone; the organic solvent 2 is at least one of ethanol, isopropanol, n-propanol, cyclohexanone and acetone; the silane coupling agent is at least one of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane.

[0018] In some embodiments of the present invention, the thermoplastic elastomer material further includes: at least one of an antioxidant, an anti-copper agent, a sensitizer, and a plasticizer; wherein, the raw materials are calculated in parts by weight, the antioxidant is 0.1-3 parts, the anti-copper agent is 0.1-5 parts, the sensitizer is 5-6 parts, and the plasticizer is 55-65 parts.

[0019] In some embodiments of the present invention, the antioxidant is at least one of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite, distearyl thiodipropionate, and dilauryl thiodipropionate; the anti-copper agent is at least one of benzotriazole and its derivatives, mercaptobenzothiazole and its derivatives, octadecylamine, and diethylamine; the sensitizer is at least one of triallyl isocyanate and trimethylolpropane triacrylate; the plasticizer is at least one of white oil, liquid paraffin, epoxidized soybean oil, and silicone oil.

[0020] In a second aspect of the present invention, there is provided a method for preparing the above-mentioned thermoplastic elastomer material, the preparation method comprising the following steps:

[0021] The raw materials are mixed evenly, the raw materials include the thermoplastic elastomer, the compound thermal conductive powder, and the reinforced plastic, and extruded, drawn, and pelletized through an extrusion device to obtain the thermoplastic elastomer material particles;

[0022] Wherein, the extrusion temperature of the extrusion equipment is 150-170°C.

[0023] According to a third aspect of the present invention, there is provided a liquid cooling tube, wherein the liquid cooling tube is made of the thermoplastic elastomer material described above.

[0024] In a fourth aspect, the present invention provides a method for preparing the above-mentioned liquid cooling tube, the method comprising the following steps:

[0025] The raw materials are mixed evenly, the raw materials include the thermoplastic elastomer, the compound thermal conductive powder, and the reinforced plastic, and extruded, drawn, and pelletized through an extrusion device to obtain the thermoplastic elastomer material particles;

[0026] Extruding the thermoplastic elastomer material particles obtained above into a tube through an extruder, and irradiating and cross-linking the tube to obtain the liquid cooling tube;

[0027] Wherein, the extrusion equipment is a twin-screw extruder, the extrusion temperature of the twin-screw extruder is 150-170°C, and the twin-screw speed range is 200-220Rpm; the extruder is a single-screw extruder, the extrusion temperature of the extruder is 160-180°C; the irradiation dose is 3-8Mrad.

[0028] The thermoplastic elastomer material of the present invention includes a thermoplastic elastomer, a compound thermally conductive powder and a reinforced plastic. Since the compound thermally conductive powder is mainly composed of graphene and a small amount of modified ceramic thermally conductive powder is added, the overall filler amount is small, so that the material has excellent thermal conductivity and has little effect on the insulation performance; further, the spherical boron nitride and spherical alumina are modified by a silane coupling agent to improve the mechanical properties and thermal conductivity of the material. The compound thermally conductive powder works synergistically with the thermoplastic elastomer and reinforced plastic, which not only improves the thermal conductivity of the thermoplastic elastomer material, but also improves its mechanical properties and aging resistance. The thermoplastic elastomer material of the present invention has good insulation performance, thermal conductivity, mechanical properties and aging resistance, and has broad application prospects in the field of liquid-cooled charging guns. DETAILED DESCRIPTION

[0029] In order to make the purpose, 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. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0030] Unless defined otherwise, all technical and scientific terms used herein have the common meaning in the art to which the claimed subject matter belongs.

[0031] Thermoplastic elastomer (TPE) is a polymer material that has both rubber elasticity and plastic processing properties. It exhibits high elasticity of rubber at room temperature, and can be processed and molded like plastic at high temperature. TPE is divided into styrene, polyolefin, polyurethane, and polyester ether. Styrene mainly includes styrene-butadiene-styrene block copolymer (SBS) and hydrogenated styrene-butadiene-styrene block copolymer (SEBS). SBS is a triblock copolymer formed by anionic polymerization of styrene (Styrene, referred to as S) and butadiene (Butadiene, referred to as B), and has the structure of SBS. SEBS is the hydrogenation product of SBS. By hydrogenating and saturating the butadiene chain segment in SBS, polyethylene (E) and polybutene (B) segments are formed. Therefore, it has better aging resistance, temperature resistance and mechanical properties. However, TPE, like most polymer materials, is a poor conductor of heat, and the simplest and most direct way to improve the thermal conductivity of polymers is to fill them with thermal conductive fillers, such as metal powder, ceramic powder, graphene, etc. However, if the thermal conductive powders are isolated or agglomerated in the resin matrix, they cannot form an effective thermal conductive channel and affect the mechanical and aging properties of the resin itself. Therefore, it is very necessary to provide a thermoplastic elastomer material with good thermal conductivity, mechanical properties and aging properties.

[0032] In order to solve the above problems, the first aspect of the present invention provides a thermoplastic elastomer material, wherein the raw materials of the thermoplastic elastomer material, measured in parts by weight, include:

[0033] Thermoplastic elastomer 70-75 parts,

[0034] Compound thermal conductive powder 25-30 parts,

[0035] Reinforced plastic 15-20 parts,

[0036] The composite thermally conductive powder comprises graphene and modified ceramic thermally conductive powder. In terms of weight percentage, the graphene accounts for 75-80% of the sum of the weight of the graphene and the modified ceramic thermally conductive powder. The modified ceramic thermally conductive powder comprises spherical boron nitride and spherical alumina, and the spherical boron nitride and spherical alumina are modified by a silane coupling agent.

[0037] It can be understood that the thermoplastic elastomer is any number between 70-75 parts, such as 70 parts, 71 parts, 72 parts, 73 parts, 74 parts, 75 parts, etc.; the compound thermal conductive powder is any number between 25-30 parts, such as 25 parts, 26 parts, 27 parts, 28 parts, 29 parts, 30 parts, etc.; the reinforced plastic is any number between 15-20 parts, such as 15 parts, 16 parts, 17 parts, 18 parts, 19 parts, 20 parts, etc.

[0038] It is understandable that when graphene and ceramic thermally conductive powder are compounded, the layered structure of graphene and the spherical appearance of ceramic powder have little effect on the processing performance, which is beneficial to the plasticization and extrusion of the material. Two spherical thermally conductive powders with different particle sizes are selected. On the one hand, the effective contact area of ​​the spherical structure is the largest. On the other hand, the spherical particles are easier to disperse during processing. If the particle size of boron nitride is small, it can fill the gaps between larger particle size alumina and form a rich and efficient thermal conductive network inside the resin. If the particle size of alumina is small, the thermal conductivity of alumina is not as good as that of boron nitride. The heat transfer efficiency between smaller particle size alumina particles is not as good as that between smaller particle size boron nitride particles. The transfer efficiency of the thermal conductive network will decrease, and the thermal conductivity will decrease. After adding ceramic thermally conductive powder, the thermal conduction path inside the resin is graphene-thermal conductive powder-graphene. Due to the excellent insulation of thermal conductive powder, the influence of graphene on the insulation performance of resin material after addition can be reduced. Furthermore, boron nitride and alumina are modified by using a silane coupling agent, and the interface bonding between the inorganic filler and the organic matrix is ​​improved through the bridging effect of the silane coupling agent, thereby improving the overall properties of the composite material, such as mechanical properties, thermal stability and chemical corrosion resistance.

[0039] The thermoplastic elastomer material of the present invention includes a thermoplastic elastomer, a compound thermally conductive powder and a reinforced plastic. Since the compound thermally conductive powder is mainly composed of graphene and a small amount of modified ceramic thermally conductive powder is added, the overall filler amount is small, so that the material has excellent thermal conductivity and has little effect on the insulation performance; further, the spherical boron nitride and spherical alumina are modified by a silane coupling agent to improve the mechanical properties and thermal conductivity of the material. The compound thermally conductive powder works synergistically with the thermoplastic elastomer and reinforced plastic, which not only improves the thermal conductivity of the thermoplastic elastomer material, but also improves its mechanical properties and aging resistance. The thermoplastic elastomer material of the present invention has good insulation performance, thermal conductivity, mechanical properties and aging resistance, and has broad application prospects in the field of liquid-cooled charging guns.

[0040] In some embodiments, the thermoplastic elastomer is a hydrogenated styrene-butadiene block copolymer, wherein the styrene block repeating unit accounts for 30-35% and the weight average molecular weight ranges from 5×10 4 -5×10 5 , the melt index is greater than 7g / 10min at 190°C and 2.16kg.

[0041] It can be understood that SEBS with 30-35% styrene blocks can, on the one hand, improve the toughness and resilience of the material, and on the other hand, the larger proportion of butadiene blocks gives the material more cross-linking sites, so that a cross-linked structure can be obtained under a low radiation dose, and it is easier to obtain micro-crosslinking through the radiation dose. The micro-crosslinking of the present invention will not have a significant effect on the toughness of the material itself, and the elongation at break changes little, but improves the material's anti-cracking performance.

[0042] In some embodiments, the reinforced plastic is at least one of isotactic polypropylene with a crystallinity of 60-75% and polyphenylene ether with a weight average molecular weight of less than 10,000.

[0043] It can be understood that the synergistic effect of SEBS and isotactic polypropylene with a crystallinity of 60-75% can significantly improve the mechanical properties, processing properties and heat resistance of the material; the synergistic effect of SEBS and polyphenylene ether with a weight-average molecular weight of less than 10,000 can significantly improve the compatibility, mechanical properties, processing properties and surface properties of the composite material.

[0044] In some embodiments, the weight ratio of the spherical boron nitride to the spherical alumina is (8:1)-(12:1); the particle size of the spherical boron nitride is in the range of 10-20 μm, and the particle size of the spherical alumina is in the range of 80-200 μm.

[0045] The particle size and shape characteristics of spherical boron nitride and spherical alumina make them have good dispersibility in composite materials and reduce agglomeration. The spherical structure filler causes less wear on equipment during processing and has better fluidity. The difference in particle size ranges of spherical boron nitride with a particle size of 10-20μm and spherical alumina with a particle size of 80-200μm enables the two to form a tightly stacked three-dimensional network structure in the composite material, which can effectively reduce thermal resistance and improve heat conduction efficiency.

[0046] In some embodiments, the method for preparing the composite thermally conductive powder is as follows:

[0047] The spherical boron nitride and the spherical aluminum oxide powder are weighed and mixed according to the weight ratio, ultrasonically dispersed in an organic solvent 1, filtered, and dried to obtain a powder A.

[0048] The powder A, siloxane coupling agent and organic solvent 2 are mixed in a ratio of 100:(1-5):(200-500) by weight, stirred at 60-75° C. for 40-80 min, heated to 80° C., stirred for 4-8 h, filtered and dried to obtain a powder B;

[0049] Mixing the powder B and the graphene to obtain the composite thermal conductive powder;

[0050] Wherein, the organic solvent 1 is at least one of ethanol, isopropanol, n-propanol, cyclohexanone and acetone; the organic solvent 2 is at least one of ethanol, isopropanol, n-propanol, cyclohexanone and acetone; the silane coupling agent is at least one of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane.

[0051] It can be understood that the preparation method of the composite thermal conductive powder is as follows:

[0052] Spherical boron nitride and spherical aluminum oxide powders were weighed and mixed in a weight ratio of (8:1)-(12:1), and ultrasonically treated for 2 hours in an organic solvent 1 with a mass fraction of 20-95% to remove keratin. After the obtained dispersion was centrifuged, the supernatant was vacuum filtered, and the filtered solid was dried at 105°C for 8 hours to obtain a powder A.

[0053] Powder A, siloxane coupling agent and organic solvent 2 are mixed in a ratio of 100:(1-5):(200-500) by weight percentage, stirred and reacted at 60-75° C. for 40-80 min, and after the siloxane coupling agent is hydrolyzed, the temperature is raised to 80° C. and stirred and reacted for 4-8 h. The mixed liquid after the reaction is filtered under vacuum, and the filtered solid is dried at 100° C. for 8-12 h to obtain powder B, which is a modified ceramic thermal conductive powder;

[0054] The powder B and the graphene are placed in a high-speed mixer with a rotation speed of 1200-1600 rpm and mixed for 20-40 minutes to obtain a composite thermal conductive powder;

[0055] Among them, organic solvent 1 is at least one of ethanol, isopropanol, n-propanol, cyclohexanone, and acetone; organic solvent 2 is at least one of ethanol, isopropanol, n-propanol, cyclohexanone, and acetone; and the silane coupling agent is at least one of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane.

[0056] In some embodiments, the weight ratio of spherical boron nitride to spherical aluminum oxide is 10:1.

[0057] In some embodiments, the organic solvent 1 is isopropanol or ethanol.

[0058] In some embodiments, the organic solvent 2 is isopropanol or ethanol.

[0059] In some embodiments, the thermoplastic vulcanizate has a melt index of 15-17 g / 10 min at 230° C. and 2.16 kg.

[0060] In some embodiments, the thermoplastic elastomer material further includes: at least one of an antioxidant, an anti-copper agent, a sensitizer, and a plasticizer; wherein, the raw materials are calculated in parts by weight, the antioxidant is 0.1-3 parts, the anti-copper agent is 0.1-5 parts, the sensitizer is 5-6 parts, and the plasticizer is 55-65 parts.

[0061] In some embodiments, the antioxidant is at least one of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite, distearyl thiodipropionate, and dilauryl thiodipropionate; the anti-copper agent is at least one of benzotriazole and its derivatives, mercaptobenzothiazole and its derivatives, octadecylamine, and diethylamine; the sensitizer is at least one of triallyl isocyanate and trimethylolpropane triacrylate; and the plasticizer is at least one of white oil, liquid paraffin, epoxidized soybean oil, and silicone oil.

[0062] By adding antioxidants, the antioxidant and aging resistance of polymer materials are beneficial, and the service life of polymer materials is extended. By adding anti-copper agents, the thermal oxidation degradation caused by accelerated catalysis by copper during the processing of polymer materials can be reduced. By adding sensitizers, the crosslinking density, heat resistance and mechanical properties of materials can be improved. By adding plasticizers, the flexibility, processing performance and surface properties of materials can be improved.

[0063] In a second aspect of the present invention, there is provided a method for preparing the above-mentioned thermoplastic elastomer material, the preparation method comprising the following steps:

[0064] The raw materials are mixed evenly, the raw materials include the thermoplastic elastomer, the compound thermal conductive powder, and the reinforced plastic, and extruded, drawn, and pelletized through an extrusion device to obtain the thermoplastic elastomer material particles;

[0065] Wherein, the extrusion temperature of the extrusion equipment is 150-170°C.

[0066] It can be understood that the raw materials are mixed evenly in a high-speed mixer. The raw materials include thermoplastic elastomer, compound thermal conductive powder, reinforced plastic, and may also include at least one of antioxidant, anti-copper agent, sensitizer, and plasticizer. The high-speed mixer is set to a speed of 400Rpm, and the material temperature is controlled to be lower than 60°C. The material is extruded through an extrusion device, such as a twin-screw extruder or a single-screw extruder, at an extrusion temperature of 150-170°C, and then extruded, stretched, and pelletized to obtain thermoplastic elastomer material particles.

[0067] It can be understood that the raw materials are mixed evenly in a high-speed mixer. The specific operation is as follows: first, the thermoplastic elastomer and the plasticizer are oil-filled in a low-speed mixer, and the oil-filled thermoplastic elastomer is mixed with the remaining raw materials, such as compound thermal conductive powder, reinforced plastic, antioxidant, anti-copper agent, and sensitizer in a high-speed mixer.

[0068] According to a third aspect of the present invention, there is provided a liquid cooling tube, wherein the liquid cooling tube is made of the thermoplastic elastomer material described above.

[0069] In a fourth aspect, the present invention provides a method for preparing the above-mentioned liquid cooling tube, the method comprising the following steps:

[0070] The raw materials are mixed evenly, the raw materials include the thermoplastic elastomer, the compound thermal conductive powder, and the reinforced plastic, and extruded, drawn, and pelletized through an extrusion device to obtain the thermoplastic elastomer material particles;

[0071] Extruding the thermoplastic elastomer material particles obtained above into a tube through an extruder, and irradiating and cross-linking the tube to obtain the liquid cooling tube;

[0072] Wherein, the extrusion equipment is a twin-screw extruder, the extrusion temperature of the twin-screw extruder is 150-170°C, and the twin-screw speed range is 200-220Rpm; the extruder is a single-screw extruder, the extrusion temperature of the extruder is 160-180°C; the irradiation dose is 3-8Mrad.

[0073] It can be understood that the raw materials are mixed evenly in a high-speed mixer. The raw materials include thermoplastic elastomer, compound thermal conductive powder, reinforced plastic, and may also include at least one of antioxidant, anti-copper agent, sensitizer, and plasticizer. The high-speed mixer is set to a speed of 400Rpm, and the material temperature is controlled to be lower than 60°C. The material is extruded through an extrusion device, such as a twin-screw extruder or a single-screw extruder, at an extrusion temperature of 150-170°C, and then extruded, stretched, and pelletized to obtain thermoplastic elastomer material particles.

[0074] It can be understood that the raw materials are mixed evenly in a high-speed mixer. The specific operation is as follows: first, the thermoplastic elastomer and the plasticizer are oil-filled in a low-speed mixer, and the oil-filled thermoplastic elastomer is mixed with the remaining raw materials, such as compound thermal conductive powder, reinforced plastic, antioxidant, anti-copper agent, and sensitizer in a high-speed mixer.

[0075] The obtained thermoplastic elastomer material particles are extruded into a pipe through an extruder, such as a single-screw extruder, at an extrusion temperature of 160-180° C. The pipe is irradiated and cross-linked with an irradiation dose of 3-8 Mrad to obtain a liquid cooling pipe.

[0076] The content of the present invention is explained below through specific examples and data.

[0077] The information of the raw materials involved in the specific implementation is shown in Table 1:

[0078] Table 1 Information of raw materials of Examples and Comparative Examples

[0079]

[0080]

[0081] Embodiment 1:

[0082] Please refer to Table 1 and Table 2. This embodiment includes the following raw materials in parts by weight:

[0083] SEBS 70 parts,

[0084] 30 parts of compound thermal conductive powder,

[0085] Polypropylene 15 parts,

[0086] Antioxidant 10761 parts,

[0087] 0.5 parts of methylbenzotriazole,

[0088] Triallyl isocyanate 5 parts,

[0089] 55 parts of white oil

[0090] The preparation process is as follows:

[0091] Preparation of compound thermal conductive powder

[0092] Spherical boron nitride and spherical aluminum oxide powders were weighed and mixed in a weight ratio of 10:1, and ultrasonically treated in a 50% isopropanol solution for 2 hours to remove keratin. The obtained dispersion was centrifuged, and the supernatant was vacuum filtered. The filtered solid was dried at 105° C. for 8 hours to obtain powder A.

[0093] Powder A, siloxane coupling agent N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and ethanol are mixed in a ratio of 100:2:200 by weight, stirred and reacted at 65° C. for 60 min, and after the siloxane coupling agent is hydrolyzed, the temperature is raised to 80° C. and stirred and reacted for 5 h. The mixed liquid after the reaction is filtered under vacuum, and the filtered solid is dried at 100° C. for 8-12 h to obtain powder B, i.e., modified ceramic thermal conductive powder;

[0094] 25 parts by weight of the powder B and 75 parts by weight of graphene were placed in a high-speed mixer at a rotation speed of 1400 rpm and mixed for 30 minutes to obtain a composite thermal conductive powder.

[0095] Preparation of thermoplastic elastomer materials

[0096] Take 70 parts by weight of SEBS and 55 parts by weight of white oil and complete oil filling in a low-speed mixer. The oil-filled SEBS and the remaining raw materials, 30 parts by weight of the above-prepared composite thermal conductive powder, 15 parts by weight of polypropylene, 1 part by weight of antioxidant 1076, and 0.5 parts by weight of methylbenzotriazole are placed in a high-speed mixer according to the weight ratio and mixed. The high-speed mixer is set to a speed of 400 Rpm, the material temperature is controlled to be lower than 60°C, and the total mixing time is 16 minutes. The uniformly mixed raw materials are extruded and granulated by a twin-screw extruder, the extrusion temperature is set to 160°C-170°C, and the screw speed adjustment range is 200-240 Rpm to obtain thermoplastic elastomer material particles.

[0097] Preparation of liquid cooling tube

[0098] The thermoplastic elastomer material prepared as above is extruded into a tube through a single screw extruder, and the processing temperatures of the four zones are set to 135-145°C, 155-165°C, 165-175°C, and 165-175°C, respectively. The head temperature is set to 160-170°C, and the rotation speed is 24±1Rpm. The obtained tube is irradiated by an electron accelerator, and the irradiation dose is set to 4Mrad to obtain the liquid-cooled tube.

[0099] Embodiment 2:

[0100] Please refer to Table 1 and Table 2. This embodiment includes the following raw materials in parts by weight:

[0101] SEBS 75 parts,

[0102] 25 parts of compound thermal conductive powder,

[0103] Polypropylene 20 parts,

[0104] Antioxidant 10761 parts,

[0105] 0.5 parts of methylbenzotriazole,

[0106] Triallyl isocyanate 5 parts,

[0107] 55 parts of white oil

[0108] The preparation process is as follows:

[0109] Preparation of compound thermal conductive powder

[0110] Spherical boron nitride and spherical aluminum oxide powders were weighed and mixed in a weight ratio of 10:1, and ultrasonically treated in a 50% isopropanol solution for 2 hours to remove keratin. The obtained dispersion was centrifuged, and the supernatant was vacuum filtered. The filtered solid was dried at 105° C. for 8 hours to obtain powder A.

[0111] Powder A, siloxane coupling agent N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and ethanol are mixed in a ratio of 100:2:200 by weight, stirred and reacted at 65° C. for 60 min, and after the siloxane coupling agent is hydrolyzed, the temperature is raised to 80° C. and stirred and reacted for 5 h. The mixed liquid after the reaction is filtered under vacuum, and the filtered solid is dried at 100° C. for 8-12 h to obtain powder B, i.e., modified ceramic thermal conductive powder;

[0112] 25 parts by weight of the powder B and 75 parts by weight of graphene were placed in a high-speed mixer at a rotation speed of 1400 rpm and mixed for 30 minutes to obtain a composite thermal conductive powder.

[0113] Preparation of thermoplastic elastomer materials

[0114] Take 75 parts by weight of SEBS and 55 parts by weight of white oil and complete oil filling in a low-speed mixer. The oil-filled SEBS and the remaining raw materials, 25 parts by weight of the above-prepared composite thermal conductive powder, 20 parts by weight of polypropylene, 1 part by weight of antioxidant 1076, and 0.5 parts by weight of methylbenzotriazole are placed in a high-speed mixer according to the weight ratio and mixed. The high-speed mixer is set to a speed of 400Rpm, the material temperature is controlled to be lower than 60°C, and the total mixing time is 16min. The uniformly mixed raw materials are extruded and granulated by a twin-screw extruder, the extrusion temperature is set to 160°C-170°C, and the screw speed adjustment range is 200-240Rpm to obtain thermoplastic elastomer material particles.

[0115] Preparation of liquid cooling tube

[0116] The thermoplastic elastomer material prepared as above is extruded into a tube through a single screw extruder, and the processing temperatures of the four zones are set to 135-145°C, 155-165°C, 165-175°C, and 165-175°C, respectively. The head temperature is set to 160-170°C, and the rotation speed is 24±1Rpm. The obtained tube is irradiated by an electron accelerator, and the irradiation dose is set to 4Mrad to obtain the liquid-cooled tube.

[0117] Embodiment 3:

[0118] Please refer to Table 1 and Table 2. This embodiment includes the following raw materials in parts by weight:

[0119] SEBS 75 parts,

[0120] 25 parts of compound thermal conductive powder,

[0121] 20 parts of polyphenylene ether,

[0122] Antioxidant 10761 parts,

[0123] 0.5 parts of methylbenzotriazole,

[0124] Triallyl isocyanate 5 parts,

[0125] 55 parts of white oil

[0126] The preparation process is as follows:

[0127] Preparation of compound thermal conductive powder

[0128] Spherical boron nitride and spherical aluminum oxide powders were weighed and mixed in a weight ratio of 10:1, and ultrasonically treated in a 50% isopropanol solution for 2 hours to remove keratin. The obtained dispersion was centrifuged, and the supernatant was vacuum filtered. The filtered solid was dried at 105° C. for 8 hours to obtain powder A.

[0129] Powder A, siloxane coupling agent N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and ethanol are mixed in a ratio of 100:2:200 by weight, stirred and reacted at 65° C. for 60 min, and after the siloxane coupling agent is hydrolyzed, the temperature is raised to 80° C. and stirred and reacted for 5 h. The mixed liquid after the reaction is filtered under vacuum, and the filtered solid is dried at 100° C. for 8-12 h to obtain powder B, i.e., modified ceramic thermal conductive powder;

[0130] 25 parts by weight of the powder B and 75 parts by weight of graphene were placed in a high-speed mixer at a rotation speed of 1400 rpm and mixed for 30 minutes to obtain a composite thermal conductive powder.

[0131] Preparation of thermoplastic elastomer materials

[0132] Take 75 parts by weight of SEBS and 55 parts by weight of white oil and complete oil filling in a low-speed mixer. The oil-filled SEBS and the remaining raw materials, 25 parts by weight of the above-prepared composite thermal conductive powder, 20 parts by weight of polyphenylene ether, 1 part by weight of antioxidant 1076, and 0.5 parts by weight of methylbenzotriazole are placed in a high-speed mixer according to the weight ratio and mixed. The high-speed mixer is set to a speed of 400 Rpm, the material temperature is controlled to be lower than 60°C, and the total mixing time is 16 minutes. The uniformly mixed raw materials are extruded and granulated by a twin-screw, the extrusion temperature is set to 160°C-170°C, and the screw speed adjustment range is 200-240 Rpm to obtain thermoplastic elastomer material particles.

[0133] Preparation of liquid cooling tube

[0134] The thermoplastic elastomer material prepared as above is extruded into a tube through a single screw extruder, and the processing temperatures of the four zones are set to 135-145°C, 155-165°C, 165-175°C, and 165-175°C, respectively. The head temperature is set to 160-170°C, and the rotation speed is 24±1Rpm. The obtained tube is irradiated by an electron accelerator, and the irradiation dose is set to 4Mrad to obtain the liquid-cooled tube.

[0135] Embodiment 4:

[0136] Please refer to Table 1 and Table 2. This embodiment includes the following raw materials in parts by weight:

[0137] SEBS 75 parts,

[0138] 25 parts of compound thermal conductive powder,

[0139] Polypropylene 20 parts,

[0140] Antioxidant 10761 parts,

[0141] 0.5 parts of methylbenzotriazole,

[0142] Triallyl isocyanate 5 parts,

[0143] 55 parts of white oil

[0144] The preparation process is as follows:

[0145] Preparation of compound thermal conductive powder

[0146] Spherical boron nitride and spherical aluminum oxide powders were weighed and mixed in a weight ratio of 10:1, and ultrasonically treated in a 50% isopropanol solution for 2 hours to remove keratin. The obtained dispersion was centrifuged, and the supernatant was vacuum filtered. The filtered solid was dried at 105° C. for 8 hours to obtain powder A.

[0147] Powder A, siloxane coupling agent N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and ethanol are mixed in a ratio of 100:2:200 by weight, stirred and reacted at 65° C. for 60 min, and after the siloxane coupling agent is hydrolyzed, the temperature is raised to 80° C. and stirred and reacted for 5 h. The mixed liquid after the reaction is filtered under vacuum, and the filtered solid is dried at 100° C. for 8-12 h to obtain powder B, i.e., modified ceramic thermal conductive powder;

[0148] 20 parts by weight of the powder B and 80 parts by weight of graphene were placed in a high-speed mixer at a rotation speed of 1400 rpm and mixed for 30 minutes to obtain a composite thermal conductive powder.

[0149] Preparation of thermoplastic elastomer materials

[0150] Take 75 parts by weight of SEBS and 55 parts by weight of white oil and complete oil filling in a low-speed mixer. The oil-filled SEBS and the remaining raw materials, 25 parts by weight of the above-prepared composite thermal conductive powder, 20 parts by weight of polypropylene, 1 part by weight of antioxidant 1076, and 0.5 parts by weight of methylbenzotriazole are placed in a high-speed mixer according to the weight ratio and mixed. The high-speed mixer is set to a speed of 400Rpm, the material temperature is controlled to be lower than 60°C, and the total mixing time is 16min. The uniformly mixed raw materials are extruded and granulated by a twin-screw extruder, the extrusion temperature is set to 160°C-170°C, and the screw speed adjustment range is 200-240Rpm to obtain thermoplastic elastomer material particles.

[0151] Preparation of liquid cooling tube

[0152] The thermoplastic elastomer material prepared as above is extruded into a tube through a single screw extruder, and the processing temperatures of the four zones are set to 135-145°C, 155-165°C, 165-175°C, and 165-175°C, respectively. The head temperature is set to 160-170°C, and the rotation speed is 24±1Rpm. The obtained tube is irradiated by an electron accelerator, and the irradiation dose is set to 4Mrad to obtain the liquid-cooled tube.

[0153] Comparative Example 1:

[0154] Please refer to Table 1 and Table 2. This comparative example includes the following raw materials in parts by weight:

[0155] SEBS 95 parts,

[0156] 25 parts of compound thermal conductive powder,

[0157] Antioxidant 10761 parts,

[0158] 0.5 parts of methylbenzotriazole,

[0159] Triallyl isocyanate 5 parts,

[0160] 55 parts of white oil

[0161] The preparation process is similar to that of Example 2, except that the weight proportions of SEBS, compound thermal conductive powder, and polypropylene are different.

[0162] Comparative Example 2:

[0163] Please refer to Table 1 and Table 2. This comparative example includes the following raw materials in parts by weight:

[0164] 25 parts of compound thermal conductive powder,

[0165] Polypropylene 95 parts,

[0166] Antioxidant 10761 parts,

[0167] 0.5 parts of methylbenzotriazole,

[0168] Triallyl isocyanate 5 parts,

[0169] 55 parts of white oil

[0170] The preparation process is similar to that of Example 2. The preparation of the compound thermal conductive powder and the preparation of the liquid cooling tube are similar to those of Example 2. The only difference is that the weight proportions of SEBS, compound thermal conductive powder, and polypropylene are different. The preparation process of the thermoplastic elastomer material is as follows:

[0171] Take 95 parts by weight of polypropylene and 55 parts by weight of white oil and complete the oil filling in a low-speed mixer. The oil-filled SEBS and the remaining raw materials, 25 parts by weight of the above-prepared composite thermal conductive powder, 1 part by weight of antioxidant 1076, and 0.5 parts by weight of methylbenzotriazole are placed in a high-speed mixer according to the weight ratio and mixed. The speed of the high-speed mixer is set to 400Rpm, the material temperature is controlled to be lower than 60°C, and the total mixing time is 16min. The evenly mixed raw materials are extruded and granulated by a twin-screw extruder, the extrusion temperature is set to 160°C-170°C, and the screw speed adjustment range is 200-240Rpm to obtain thermoplastic elastomer material particles. The rest of the preparation process is similar. Comparative Example 3:

[0172] Please refer to Table 1 and Table 2. This comparative example includes the following raw materials in parts by weight:

[0173] SEBS 80 parts,

[0174] Polypropylene 40 parts,

[0175] Antioxidant 10761 parts,

[0176] 0.5 parts of methylbenzotriazole,

[0177] Triallyl isocyanate 5 parts,

[0178] 55 parts of white oil

[0179] The preparation process is similar to that of Example 2, except that the weight proportions of SEBS, compound thermal conductive powder, and polypropylene are different.

[0180] Comparative Example 4:

[0181] Please refer to Table 1 and Table 2. This comparative example includes the following raw materials in parts by weight:

[0182] SEBS 75 parts,

[0183] 35 parts of compound thermal conductive powder,

[0184] Polypropylene 10 parts,

[0185] Antioxidant 10761 parts,

[0186] 0.5 parts of methylbenzotriazole,

[0187] Triallyl isocyanate 5 parts,

[0188] 55 parts of white oil

[0189] The preparation process is similar to that of Example 2, except that the weight proportions of SEBS, compound thermal conductive powder, and polypropylene are different.

[0190] Comparative Example 5:

[0191] This comparative example is similar to Example 2, except that the liquid cooling tube is not irradiated during the preparation process.

[0192] This comparative example is similar to Example 2, except that the ceramic thermally conductive powder is not modified with a silane coupling agent during the preparation of the composite thermally conductive powder.

[0193] Comparative Example 7

[0194] This comparative example is similar to Example 2, except that the weight ratio of graphene to modified ceramic thermally conductive powder is different during the preparation of the composite thermally conductive powder, as follows:

[0195] Spherical boron nitride and spherical aluminum oxide powders were weighed and mixed in a weight ratio of 10:1, and ultrasonically treated in a 50% isopropanol solution for 2 hours to remove keratin. The obtained dispersion was centrifuged, and the supernatant was vacuum filtered. The filtered solid was dried at 105° C. for 8 hours to obtain powder A.

[0196] Powder A, siloxane coupling agent N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and ethanol are mixed in a ratio of 100:2:200 by weight, stirred and reacted at 65° C. for 60 min, and after the siloxane coupling agent is hydrolyzed, the temperature is raised to 80° C. and stirred and reacted for 5 h. The mixed liquid after the reaction is filtered under vacuum, and the filtered solid is dried at 100° C. for 8-12 h to obtain powder B, i.e., modified ceramic thermal conductive powder;

[0197] 10 parts by weight of the powder B and 90 parts by weight of graphene were placed in a high-speed mixer at a rotation speed of 1400 rpm and mixed for 30 minutes to obtain a composite thermal conductive powder.

[0198] Comparative Example 8

[0199] This comparative example is similar to Example 2, except that the weight ratio of graphene to modified ceramic thermally conductive powder is different during the preparation of the composite thermally conductive powder, as follows:

[0200] Spherical boron nitride and spherical aluminum oxide powders were weighed and mixed in a weight ratio of 10:1, and ultrasonically treated in a 50% isopropanol solution for 2 hours to remove keratin. The obtained dispersion was centrifuged, and the supernatant was vacuum filtered. The filtered solid was dried at 105° C. for 8 hours to obtain powder A.

[0201] Powder A, siloxane coupling agent N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and ethanol are mixed in a ratio of 100:2:200 by weight, stirred and reacted at 65° C. for 60 min, and after the siloxane coupling agent is hydrolyzed, the temperature is raised to 80° C. and stirred and reacted for 5 h. The mixed liquid after the reaction is filtered under vacuum, and the filtered solid is dried at 100° C. for 8-12 h to obtain powder B, i.e., modified ceramic thermal conductive powder;

[0202] 35 parts by weight of the powder B and 65 parts by weight of graphene were placed in a high-speed mixer at a rotation speed of 1400 rpm and mixed for 30 minutes to obtain a composite thermal conductive powder.

[0203] The liquid cooling tubes prepared in the above embodiments and comparative examples were tested for thermal conductivity, volume resistivity, trouser tear, tensile strength, elongation at break, heat aging resistance, silicone oil aging resistance, E4 oil aging resistance, and water + ethylene glycol aging resistance. The test standards are as follows:

[0204] (1) Thermal conductivity

[0205] According to GB / T 3399-1982, use the IMDRY600-II intelligent flat-plate thermal conductivity tester. The sample is round or square, with a diameter or side length equal to the protective heating plate, a thickness of 5mm, and a maximum thickness not exceeding 1 / 8 of its diameter or side length. Install the sample between the heating plate and the cold plate to ensure that the sample is in close contact with the heating plate and the cold plate. Measure the heat flow through the effective heat transfer area of ​​the sample, the temperature difference between the two surfaces of the sample, and the thickness. Based on the measured data, calculate the thermal conductivity of the plastic according to the formula. The formula is: λ=Qd / AΔT, where λ is the thermal conductivity (W / (m·K)), Q is the heat flow through the sample (W), d is the sample thickness (m), and A is the effective heat transfer area of ​​the sample (m 2), ΔT is the temperature difference between the two surfaces of the sample (K), three samples were tested and the results were averaged.

[0206] (2) Volume resistivity

[0207] According to GB / T 15662-1995, use HIOKI SM7110 high resistance meter to test, place 1mm thick flat sheet sample in the electrode device, and ensure that the sample is in good contact with the electrode. Select 1000V voltage gear test, apply the test voltage, and read the resistance value displayed by the high resistance meter after the current stabilizes. Measure each sample at least 3 times at different positions and calculate the average value. According to the measured resistance value and sample size, calculate the volume resistivity according to the formula given in the standard. Test 3 samples and take the average value of the results.

[0208] (3) Pants-shaped tear

[0209] According to GB / T 16578.1-2008, the trouser-shaped tear test is carried out. A trouser-shaped specimen of specified size is cut from the plastic sheet to be tested. Generally, the specimen width is (100±0.5) mm and the length is not less than 200 mm. A cut of (20±0.5) mm is made perpendicular to the longitudinal axis direction at a distance of (100±0.5) mm from one end of the specimen. The specimen is clamped in the fixture of the tensile testing machine so that the longitudinal axis of the specimen coincides with the center line of the fixture. The cut is located in the middle of the fixture. The specimen is stretched at a speed of (100±10) mm / min until the specimen is torn. The maximum force value during the tearing process of the specimen is recorded, which is the trouser-shaped tear force. The trouser-shaped tear strength of each specimen is calculated using the formula: T=F / d, where T is the trouser-shaped tear strength (N / mm), F is the trouser-shaped tear force (N), and d is the specimen thickness (mm). The test was conducted using the micro-controlled electronic universal material tensile testing machine of Dongguan High-speed Railway Testing Co., Ltd., and the arithmetic mean of the trouser-shaped tear strength of a group of specimens was taken as the test result. A group shall contain at least three groups of valid test results.

[0210] (4) Tensile strength and elongation at break

[0211] The test was conducted in accordance with Article 9 of GB 1040-2008, the test temperature was 23±2℃, and the tensile test used a standard dumbbell-shaped specimen with a tensile speed of 250mm / min. The tensile strength and elongation at break of three specimens were tested using a micro-controlled electronic universal material tensile machine from Dongguan High-speed Railway Testing Co., Ltd., and the results were averaged.

[0212] (5) Aging performance

[0213]

[0214] Place the sample in an aging box and test the aging of the sample in air, silicone oil, E4 oil, and water coolant. The test conditions are set as shown in the table. The aging performance is characterized by the change rate of tensile strength and the change rate of elongation at break. Three samples are tested for each aging condition, and the results are averaged.

[0215] The test results are shown in Table 3.

[0216] Table 2 Examples of the present invention and comparative examples

[0217]

[0218]

[0219]

[0220] Table 3 Performance test table of the embodiments of the present invention and comparative examples

[0221]

[0222]

[0223]

[0224] It can be seen from Table 3 that the thermal conductivity of the liquid cooling tubes in Examples 1-4 is greater than 0.8 W / (m K), the thermal conductivity is good, and the volume resistivity is greater than 5.0×10 12 , good insulation performance, trouser tear greater than 30kN / m, good tear resistance, tensile strength greater than 18MPa, elongation at break greater than 200%, high strength, good toughness, good overall mechanical properties, heat aging resistance, silicone oil aging resistance, E4 oil aging resistance, water cooling liquid aging resistance, tensile strength change rate and elongation at break change rate are less than 20%, and aging resistance is good. This shows that the thermoplastic elastomer material of the present invention has good insulation performance, thermal conductivity, mechanical properties and aging resistance at the same time, and has broad application prospects in the field of liquid-cooled charging guns.

[0225] Example 2 and Comparative Example 1 show that the amount of SEBS in the material is too high, the amount of compounded thermal conductive powder remains unchanged, and polypropylene is not added. The thermal conductivity of the liquid cooling tube is reduced, the thermal conductivity is reduced, the volume resistivity and elongation at break are increased, the insulation performance and toughness are improved, the trouser-shaped tear and tensile strength are reduced, the tear resistance and strength are reduced, the tensile strength change rate of heat aging is greater than 20%, the tensile strength change rate and elongation at break change rate of E4 oil aging are both greater than 20%, and the aging resistance is reduced; Example 2 and Comparative Example 2 show that the amount of SEBS in the material is too low, the amount of compounded thermal conductive powder remains unchanged, and the polypropylene content is If the temperature is too high, the thermal conductivity of the liquid cooling tube will increase, the thermal conductivity will be improved, the volume resistivity will increase, the insulation performance will increase, the trouser tear, tensile strength, and elongation at break will decrease, the tear resistance, strength, and toughness will all decrease, the change rate of tensile strength and elongation at break after heat aging will be greater than 20%, the change rate of tensile strength after silicone oil heat aging will be greater than 20%, the change rate of tensile strength and elongation at break after E4 oil aging will be greater than 20%, and the aging resistance will decrease. This is because polypropylene is not resistant to radiation. If the amount is too high, the chain will break after irradiation, which will cause the aging performance of the liquid cooling tube to deteriorate. It can be seen from Example 2 and Comparative Example 3 that It is found that when the amount of SEBS is increased in the material, the compound thermal conductive powder is not added, the amount of polypropylene is increased, the thermal conductivity of the liquid cooling tube is reduced, the thermal conductivity is reduced, the volume resistivity and elongation at break are increased, the insulation performance and toughness are increased, the trouser-shaped tear and tensile strength are reduced, the tear resistance and strength are reduced, the tensile strength change rate and elongation at break of heat aging resistance are both greater than 20%, the tensile strength change rate and elongation at break of silicone oil heat aging resistance are both greater than 20%, the tensile strength change rate and elongation at break of E4 oil aging resistance are both greater than 20%, and the aging resistance is reduced; Example 2 and Comparative Example 4 can be seen The results show that when the amount of SEBS in the material remains unchanged, the amount of the compounded thermal conductive powder is increased, and the amount of polypropylene is reduced, the thermal conductivity of the liquid cooling tube is increased, the thermal conductivity performance is improved, the volume resistivity, trouser tear, tensile strength, and elongation at break are all reduced, the insulation performance, tear resistance, strength, and toughness are all reduced, the change rate of the tensile strength after heat aging is greater than 20%, the change rate of the tensile strength after E4 oil aging is greater than 20%, and the aging resistance performance is reduced; thus, it is explained that the compounded thermal conductive powder of the present invention synergizes with the thermoplastic elastomer and the reinforced plastic to not only improve the thermal conductivity of the thermoplastic elastomer material, but also improve its mechanical properties and aging resistance.

[0226] It can be seen from Example 2 and Comparative Example 5 that the liquid cooling tube is not irradiated and cross-linked, the elongation at break of the liquid cooling tube increases, and the other thermal conductivity, volume resistivity, trouser tear and tensile strength are all reduced, and the aging performance deteriorates. Irradiation cross-linking limits the random thermal motion of the polymer chain of SEBS to a certain extent, and at the same time limits the movement of the compound thermal conductive powder in the resin matrix, reducing the risk of powder agglomeration and precipitation. Irradiation cross-linking optimizes the thermal conductivity, mechanical properties and aging resistance of the material.

[0227] It can be seen from Example 2 and Comparative Example 6 that the thermal conductivity of the liquid cooling tube is reduced without modification of the ceramic thermally conductive powder, the thermal conductivity is reduced, the volume resistivity, trouser tear, tensile strength, and elongation at break are all reduced, the insulation performance, tear resistance, strength, and toughness are all reduced, the change rate of tensile strength and elongation at break under heat aging are both greater than 20%, the change rate of tensile strength under silicone oil aging is greater than 20%, the change rate of tensile strength and elongation at break under E4 oil aging are both greater than 20%, and the aging resistance is reduced. This is because the ceramic thermally conductive powder improves its dispersion in the polymer after modification, and therefore, the thermal conductivity, insulation performance, mechanical properties, and aging resistance of the material can be improved.

[0228] It can be seen from Example 2 and Comparative Example 7 that the content of graphene in the compound thermally conductive powder increases, the content of thermally conductive powder decreases, the thermal conductivity of the liquid cooling tube increases, the thermal conductivity is improved, the volume resistivity, trouser tear, tensile strength, and elongation at break are all reduced, the insulation performance, tear resistance, strength, and toughness are all reduced, and the change rate of tensile strength resistant to E4 oil aging is greater than 20%, and the aging resistance is reduced; It can be seen from Example 2 and Comparative Example 8 that the content of graphene in the compound thermally conductive powder decreases, the content of thermally conductive powder increases, the thermal conductivity of the liquid cooling tube decreases, the thermal conductivity decreases, the volume resistivity increases, the insulation performance increases, the trouser tear, tensile strength, and elongation at break are all reduced, the tear resistance, strength, and toughness are all reduced, the change rate of tensile strength resistant to heat aging is greater than 20%, the change rate of tensile strength resistant to E4 oil aging and the change rate of elongation at break are both greater than 20%, and the aging resistance is reduced, which shows that the content of graphene in the compound thermally conductive powder cannot be too high or too low, otherwise it will affect the thermal conductivity, insulation performance, mechanical properties and aging resistance.

[0229] The above are only preferred embodiments of the present invention, and do not limit the patent scope of the present invention. For those skilled in the art, the present invention may have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the patent protection scope of the present invention.

Claims

1. A thermoplastic elastomer material, characterized in that: The raw materials of the thermoplastic elastomer material include, by weight: Thermoplastic elastomer 70-75 parts, Compound thermal conductive powder 25-30 parts, Reinforced plastic 15-20 parts, The composite thermally conductive powder comprises graphene and modified ceramic thermally conductive powder. In terms of weight percentage, the graphene accounts for 75-80% of the sum of the weight of the graphene and the modified ceramic thermally conductive powder. The modified ceramic thermally conductive powder comprises spherical boron nitride and spherical alumina. The particle size of the boron nitride is smaller than that of the alumina. The spherical boron nitride and the spherical alumina are modified by a silane coupling agent.

2. The thermoplastic elastomer material according to claim 1, wherein the thermoplastic elastomer is a hydrogenated styrene-butadiene block copolymer, wherein the styrene block repeating unit accounts for 30-35% and the weight average molecular weight ranges from 5×10 4 -5×10 5 , the melt index is greater than 7g / 10min at 190°C and 2.16kg.

3. The thermoplastic elastomer material according to claim 1, wherein the reinforced plastic is at least one of isotactic polypropylene with a crystallinity of 60-75% and polyphenylene ether with a weight average molecular weight of less than 10,000.

4. The thermoplastic elastomer material according to claim 1, characterized in that The weight ratio of the spherical boron nitride to the spherical alumina is (8:1)-(12:1); the particle size range of the spherical boron nitride is 10-20 μm, and the particle size range of the spherical alumina is 80-200 μm.

5. The thermoplastic elastomer material according to claim 4, characterized in that The preparation method of the composite thermal conductive powder is as follows: The spherical boron nitride and the spherical aluminum oxide powder are weighed and mixed according to the weight ratio, ultrasonically dispersed in an organic solvent 1, filtered, and dried to obtain a powder A. The powder A, siloxane coupling agent and organic solvent 2 are mixed in a ratio of 100:(1-5):(200-500) by weight, stirred at 60-75° C. for 40-80 min, heated to 80° C., stirred for 4-8 h, filtered and dried to obtain a powder B; Mixing the powder B and the graphene to obtain the composite thermal conductive powder; Wherein, the organic solvent 1 is at least one of ethanol, isopropanol, n-propanol, cyclohexanone and acetone; the organic solvent 2 is at least one of ethanol, isopropanol, n-propanol, cyclohexanone and acetone; the silane coupling agent is at least one of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane.

6. The thermoplastic elastomer material according to claim 1, characterized in that The thermoplastic elastomer material also includes: at least one of an antioxidant, an anti-copper agent, a sensitizer, and a plasticizer; wherein, the raw materials are calculated by weight, the antioxidant is 0.1-3 parts, the anti-copper agent is 0.1-5 parts, the sensitizer is 5-6 parts, and the plasticizer is 55-65 parts.

7. The thermoplastic elastomer material according to claim 6, characterized in that The antioxidant is at least one of β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate, bis(2,4-di-tert-butylphenol) pentaerythritol diphosphite, distearyl thiodipropionate, and dilauryl thiodipropionate; the anti-copper agent is at least one of benzotriazole and its derivatives, mercaptobenzothiazole and its derivatives, octadecylamine, and diethylamine; the sensitizer is at least one of triallyl isocyanate and trimethylolpropane triacrylate; and the plasticizer is at least one of white oil, liquid paraffin, epoxidized soybean oil, and silicone oil.

8. A method for preparing a thermoplastic elastomer material according to any one of claims 1 to 7, characterized in that: The preparation method comprises the following steps: The raw materials are mixed evenly, the raw materials include the thermoplastic elastomer, the compound thermal conductive powder, and the reinforced plastic, and extruded, drawn, and pelletized through an extrusion device to obtain the thermoplastic elastomer material particles; Wherein, the extrusion temperature of the extrusion equipment is 150-170°C.

9. A liquid cooling tube, characterized in that: The liquid cooling tube is made of the thermoplastic vulcanized rubber material according to any one of claims 1 to 7.

10. A method for preparing a liquid cooling tube as claimed in claim 9, characterized in that: The preparation method comprises the following steps: The raw materials are mixed evenly, the raw materials include the thermoplastic elastomer, the compound thermal conductive powder, and the reinforced plastic, and extruded, drawn, and pelletized through an extrusion device to obtain the thermoplastic elastomer material particles; Extruding the thermoplastic elastomer material particles obtained above into a tube through an extruder, and irradiating and cross-linking the tube to obtain the liquid cooling tube; Wherein, the extrusion equipment is a twin-screw extruder, the extrusion temperature of the twin-screw extruder is 150-170°C, and the twin-screw speed range is 200-220Rpm; the extruder is a single-screw extruder, the extrusion temperature of the extruder is 160-180°C; the irradiation dose is 3-8Mrad.

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