Thermoplastic vulcanized rubber material and preparation method thereof as well as liquid cooling pipe and preparation method thereof

Abstract

The invention discloses a thermoplastic vulcanized rubber material which comprises modified thermoplastic vulcanized rubber and modified boron nitride. The silane coupling agent modified boron nitride is connected with polypropylene in the modified thermoplastic vulcanized rubber in a hydrogen bond form, so that the boron nitride is limited to be dispersed in continuous-phase polypropylene, the'island structure 'of the thermoplastic vulcanized rubber is not influenced, and the interfacial compatibility between a continuous phase and a dispersed phase of the thermoplastic vulcanized rubber is not damaged; the thermoplastic vulcanized rubber material has relatively good toughness; although the hydrogen bonds are fractured in the processing process, the processability of the thermoplastic vulcanized rubber cannot be additionally reduced, so that the thermoplastic vulcanized rubber can still keep good fluidity and plasticity in the processing process, and meanwhile, in the use process, as the boron nitride is mainly dispersed in a continuous phase and forms a heat conduction channel in the continuous phase, the heat conduction performance of the thermoplastic vulcanized rubber is improved. A heat conduction path avoids a dispersed phase, and interruption of a phonon heat transfer path is avoided, so that the addition amount of the heat conduction filler can be remarkably reduced on the premise of reaching the same heat conductivity coefficient, and the mechanical property of the material is ensured. The thermoplastic vulcanized rubber material disclosed by the invention is relatively good in heat-conducting property and mechanical property, 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 vulcanized rubber material. Background Art

[0002] Thermoplastic vulcanizate (TPV) is a thermoplastic elastomer prepared by dispersing ethylene propylene diene monomer (EPDM) into polypropylene (PP) material using a dynamic vulcanization method. It has both the high toughness of rubber and the plasticity of plastic and is widely used in the automotive, home appliance, cable and other industries. However, its thermal conductivity is low. If it is directly used as a heat pipe without adding thermal conductive fillers, the liquid cooling gun produced has poor heat dissipation and cannot support a large charging current. Filling thermal conductive powder in TPV resin improves thermal conductivity. If there is too little thermal conductive filler, the thermal conductivity of the resin will hardly be improved. If it is added excessively, the processing performance of the resin will be affected. For pipes, adding excessive fillers will not only increase the risk of cracking of the pipe, but also affect the interfacial compatibility between the dispersed phase and the continuous phase of TPV, causing the mechanical properties of TPV, such as toughness, to deteriorate sharply. Therefore, it is very necessary to develop a TPV material with good thermal conductivity and mechanical properties. Summary of the invention

[0003] In view of the above-mentioned deficiencies in the prior art, the present invention proposes a thermoplastic vulcanized rubber material, aiming to solve the problem that the thermal conductivity and mechanical properties of the current TPV 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, the present invention provides a thermoplastic vulcanized rubber material, wherein the raw materials of the thermoplastic vulcanized rubber material, measured in parts by weight, include:

[0006] Modified thermoplastic vulcanized rubber 65-70 parts,

[0007] 30-35 parts of modified boron nitride,

[0008] Wherein, the modified thermoplastic vulcanized rubber is hydroxylated thermoplastic vulcanized rubber, and the modified boron nitride is boron nitride modified by a silane coupling agent.

[0009] In some embodiments of the present invention, the method for preparing the hydroxylated thermoplastic vulcanizate comprises the following steps:

[0010] Sulfuric acid is added to the potassium permanganate aqueous solution to adjust the pH to 0.9-1.1, and then the thermoplastic vulcanized rubber powder is added, stirred, heated to 60-70° C., reacted for 2.0-4.0 hours, and filtered to obtain the hydroxylated thermoplastic vulcanized rubber.

[0011] In some embodiments of the present invention, the weight ratio of the potassium permanganate to the thermoplastic vulcanizate is (1:50)-(1:100).

[0012] In some embodiments of the present invention, the method for preparing the silane coupling agent-modified boron nitride comprises the following steps:

[0013] A silane coupling agent and an organic solvent are prepared into a silane coupling agent organic solution in a weight ratio of (0.5:100) to (5:100), the pH of the silane coupling agent organic solution is adjusted to 3-5, and stirred to obtain a hydrolyzed silane coupling agent solution;

[0014] The boron nitride and the organic solvent are prepared into a boron nitride suspension in a weight ratio of (1:10) to (1:15);

[0015] Adding the boron nitride suspension to the hydrolyzed silane coupling agent solution, stirring and reacting at 65-75° C. for 2-4 hours, filtering, washing and drying the solution after the reaction to obtain boron nitride modified with a silane coupling agent;

[0016] Wherein, the organic solvent is at least one of ethanol, isopropanol, n-propanol, cyclohexanone and acetone.

[0017] In some embodiments of the present invention, the silane coupling agent is at least one of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane;

[0018] And / or, the boron nitride is hexagonal boron nitride with a particle size range of 3-10 μm;

[0019] And / or, the weight ratio of the silane coupling agent to the boron nitride is (0.5:100)-(1:100).

[0020] In some embodiments of the present invention, the melt index of the thermoplastic vulcanizate is 15-17 g / 10 min at 230° C. and 2.16 kg.

[0021] In some embodiments of the present invention, the thermoplastic vulcanized rubber material further comprises: at least one of an antioxidant and an anti-copper agent; wherein, based on the raw materials in parts by weight, the antioxidant comprises 0.5-2 parts, and the anti-copper agent comprises 0.1-1 parts.

[0022] In some embodiments of the present invention, the antioxidant is at least one of an amine antioxidant, an imine antioxidant, a thio antioxidant, and a phosphite antioxidant; the anti-copper agent is at least one of an azole anti-copper agent, a thiophene anti-copper agent, and a hydrazine anti-copper agent;

[0023] And / or, the antioxidant is at least one of tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate] pentaerythritol ester (antioxidant 1010) and tris(2,4-di-tert-butylphenyl) phosphite; the anti-copper agent is at least one of benzotriazole and its derivatives, mercaptobenzothiazole and its derivatives, octadecylamine, and diethylamine.

[0024] In a second aspect of the present invention, there is provided a method for preparing the above-mentioned thermoplastic vulcanized rubber material, the preparation method comprising the following steps:

[0025] The raw materials are mixed evenly, wherein the raw materials include the modified thermoplastic vulcanized rubber and the modified boron nitride, and extruded, drawn and pelletized by an extrusion device to obtain thermoplastic vulcanized rubber material particles;

[0026] Wherein, the extrusion temperature of the extrusion equipment is 160-170°C.

[0027] 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 vulcanized rubber material described above.

[0028] In a fourth aspect, the present invention provides a method for preparing the above-mentioned liquid cooling tube, the method comprising the following steps:

[0029] The raw materials are mixed evenly, wherein the raw materials include the modified thermoplastic vulcanized rubber and the modified boron nitride, and extruded, drawn and pelletized by an extrusion device to obtain thermoplastic vulcanized rubber material particles;

[0030] The thermoplastic vulcanized rubber material particles obtained above are extruded into a pipe through an extruder to obtain the liquid cooling pipe;

[0031] Wherein, the extrusion equipment is a twin-screw extruder, and the extrusion temperature of the extrusion equipment is 160-170°C; the extruder is a single-screw extruder, and the extrusion temperature of the extruder is 160-180°C.

[0032] The thermoplastic vulcanized rubber material of the present invention comprises modified thermoplastic vulcanized rubber and modified boron nitride. Since the boron nitride modified by the silane coupling agent is connected to the polypropylene in the modified thermoplastic vulcanized rubber in the form of hydrogen bonds, the boron nitride is limited to be dispersed in the continuous phase polypropylene, does not affect the "island structure" of the thermoplastic vulcanized rubber, does not destroy the interface compatibility between the continuous phase and the dispersed phase of the thermoplastic vulcanized rubber, and makes the thermoplastic vulcanized rubber material have good toughness; although the hydrogen bond will be broken during the processing, it will not additionally reduce the processing performance of the thermoplastic vulcanized rubber, so that the thermoplastic vulcanized rubber can still maintain good fluidity and plasticity during processing, and at the same time, during use, since the boron nitride is mainly dispersed in the continuous phase, the boron nitride forms a heat conduction path in the continuous phase, and the heat conduction path avoids the dispersed phase, avoiding the interruption of the phonon heat transfer path, so that under the premise of achieving the same thermal conductivity, the addition amount of the heat conductive filler can be significantly reduced, and the mechanical properties of the material are guaranteed. The thermoplastic vulcanized rubber material of the present invention has good thermal conductivity and mechanical properties and has broad application prospects in the field of liquid-cooled charging guns. DETAILED DESCRIPTION

[0033] 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.

[0034] Unless defined otherwise, all technical and scientific terms used herein have the common meaning in the art to which the claimed subject matter belongs.

[0035] Thermoplastic vulcanizate (TPV) is a thermoplastic elastomer prepared by dispersing ethylene propylene diene monomer (EPDM) into polypropylene (PP) material using a dynamic vulcanization method. It has both the high toughness of rubber and the plasticity of plastic and is widely used in the automotive, home appliance, cable and other industries. However, its thermal conductivity is low. If it is directly used as a heat pipe without adding thermal conductive fillers, the liquid cooling gun produced has poor heat dissipation and cannot support a large charging current. Filling thermal conductive powder in TPV resin improves thermal conductivity. If there is too little thermal conductive filler, the thermal conductivity of the resin will hardly be improved. If it is added excessively, the processing performance of the resin will be affected. For pipes, adding excessive fillers will not only increase the risk of cracking of the pipe, but also affect the interfacial compatibility between the dispersed phase and the continuous phase of TPV, causing the mechanical properties of TPV, such as toughness, to deteriorate sharply. Therefore, it is very necessary to develop a TPV material with good thermal conductivity and mechanical properties.

[0036] In order to solve the above problems, the first aspect of the present invention provides a thermoplastic vulcanized rubber material. The raw materials of the thermoplastic vulcanized rubber material, measured by weight, include:

[0037] Modified thermoplastic vulcanized rubber 65-70 parts,

[0038] 30-35 parts of modified boron nitride,

[0039] Wherein, the modified thermoplastic vulcanized rubber is hydroxylated thermoplastic vulcanized rubber, and the modified boron nitride is boron nitride modified by a silane coupling agent.

[0040] It can be understood that the modified thermoplastic vulcanizate is any number between 65-70 parts, such as 65 parts, 66 parts, 67 parts, 68 parts, 69 parts, 70 parts, etc.; the modified boron nitride is any number between 30-35 parts, such as 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, etc.

[0041] The thermoplastic vulcanized rubber material of the present invention comprises modified thermoplastic vulcanized rubber and modified boron nitride. Since the boron nitride modified by the silane coupling agent is connected to the polypropylene in the modified thermoplastic vulcanized rubber in the form of hydrogen bonds, the boron nitride is limited to be dispersed in the continuous phase polypropylene, does not affect the "island structure" of the thermoplastic vulcanized rubber, does not destroy the interface compatibility between the continuous phase and the dispersed phase of the thermoplastic vulcanized rubber, and makes the thermoplastic vulcanized rubber material have good toughness; although the hydrogen bond will be broken during the processing, it will not additionally reduce the processing performance of the thermoplastic vulcanized rubber, so that the thermoplastic vulcanized rubber can still maintain good fluidity and plasticity during processing, and at the same time, during use, since the boron nitride is mainly dispersed in the continuous phase, the boron nitride forms a heat conduction path in the continuous phase, and the heat conduction path avoids the dispersed phase, avoiding the interruption of the phonon heat transfer path, so that under the premise of achieving the same thermal conductivity, the addition amount of the heat conductive filler can be significantly reduced, and the mechanical properties of the material are guaranteed. The thermoplastic vulcanized rubber material of the present invention has good thermal conductivity and mechanical properties and has broad application prospects in the field of liquid-cooled charging guns.

[0042] In some embodiments, the method for preparing the hydroxylated thermoplastic vulcanizate comprises the following steps:

[0043] Sulfuric acid is added to the potassium permanganate aqueous solution to adjust the pH to 0.9-1.1, and then the thermoplastic vulcanized rubber powder is added, stirred, heated to 60-70° C., reacted for 2.0-4.0 hours, and filtered to obtain the hydroxylated thermoplastic vulcanized rubber.

[0044] It can be understood that in a reactor, a certain amount of potassium permanganate is dissolved in deionized water, stirred evenly, sulfuric acid is added to adjust the pH of the solution to 0.9-1.1, the thermoplastic vulcanized rubber powder is added to the prepared potassium permanganate solution, the stirrer is turned on, and the mixture is heated to 60-70°C, and the temperature is maintained for 2.0-4.0 hours. The modified thermoplastic vulcanized rubber is separated from the liquid by filtration, rinsed with deionized water until no potassium permanganate residue is detected in the washing liquid, and dried in an oven to obtain a hydroxylated thermoplastic vulcanized rubber.

[0045] In some embodiments, the heating temperature is 65° C. and the reaction time is 3.5 h.

[0046] In some embodiments, the weight ratio of the potassium permanganate to the thermoplastic vulcanizate is (1:50) to (1:100).

[0047] In some embodiments, the method for preparing the silane coupling agent-modified boron nitride comprises the following steps:

[0048] A silane coupling agent and an organic solvent are prepared into a silane coupling agent organic solution in a weight ratio of (0.5:100) to (5:100), the pH of the silane coupling agent organic solution is adjusted to 3-5, and stirred to obtain a hydrolyzed silane coupling agent solution;

[0049] The boron nitride and the organic solvent are prepared into a boron nitride suspension in a weight ratio of (1:10) to (1:15);

[0050] Adding the boron nitride suspension to the hydrolyzed silane coupling agent solution, stirring and reacting at 65-75° C. for 2-4 hours, filtering, washing and drying the solution after the reaction to obtain boron nitride modified with a silane coupling agent;

[0051] Wherein, the organic solvent is at least one of ethanol, isopropanol, n-propanol, cyclohexanone and acetone.

[0052] It can be understood that the silane coupling agent and the organic solvent are configured to form a silane coupling agent organic solution according to a weight ratio of (0.5:100)-(5:100), and the solution pH is adjusted to 3-5 with hydrochloric acid, and stirred until the silane coupling agent is completely hydrolyzed; boron nitride and the organic solvent are configured to form a boron nitride suspension according to a weight ratio of (1:10)-(1:15), and the suspension is placed in an ultrasonic cleaner and dispersed for at least 20 minutes until there is no obvious agglomerated powder; the boron nitride suspension is added to the hydrolyzed silane coupling agent solution, and the reaction is stirred at 65-75°C for 2-4h, and the stirring speed is 300-500Rpm. The solution after the reaction is filtered, washed, and dried to obtain boron nitride modified with a silane coupling agent.

[0053] In some embodiments, the weight ratio of the silane coupling agent to the organic solvent is 1:100.

[0054] In some embodiments, the reaction temperature is 70°C.

[0055] In some embodiments, the reaction time is 3 h.

[0056] In some embodiments, the organic solvent is ethanol.

[0057] In some embodiments, the solvent is ethanol.

[0058] In some embodiments, the silane coupling agent is at least one of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane;

[0059] And / or, the boron nitride is hexagonal boron nitride with a particle size range of 3-10 μm;

[0060] And / or, the weight ratio of the silane coupling agent to the boron nitride is (0.5:100)-(1:100).

[0061] In some embodiments, the thermoplastic vulcanizate has a melt index of 15-17 g / 10 min at 230° C. and 2.16 kg.

[0062] In some embodiments, the thermoplastic vulcanized rubber material further comprises: at least one of an antioxidant and an anti-copper agent; wherein, based on the raw materials in parts by weight, the antioxidant comprises 0.5-2 parts, and the anti-copper agent comprises 0.1-1 parts.

[0063] In some embodiments, the antioxidant is at least one of an amine antioxidant, an imine antioxidant, a thio antioxidant, and a phosphite antioxidant; the anti-copper agent is at least one of an azole anti-copper agent, a thiophene anti-copper agent, and a hydrazine anti-copper agent;

[0064] And / or, the antioxidant is at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and tris(2,4-di-tert-butylphenyl) phosphite; the anti-copper agent is at least one of benzotriazole and its derivatives, mercaptobenzothiazole and its derivatives, octadecylamine, and diethylamine.

[0065] By adding antioxidants, the anti-oxidation and anti-aging properties 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.

[0066] In a second aspect of the present invention, there is provided a method for preparing the above-mentioned thermoplastic vulcanized rubber material, the preparation method comprising the following steps:

[0067] The raw materials are mixed evenly, wherein the raw materials include the modified thermoplastic vulcanized rubber and the modified boron nitride, and extruded, drawn and pelletized by an extrusion device to obtain thermoplastic vulcanized rubber material particles;

[0068] Wherein, the extrusion temperature of the extrusion equipment is 160-170°C.

[0069] It can be understood that the raw materials are mixed evenly in a high-speed mixer, the raw materials include modified thermoplastic vulcanized rubber, modified boron nitride, and may also include at least one of an antioxidant and an anti-copper agent, the high-speed mixer is set to a speed of <600Rpm, the material temperature is controlled to be lower than 60°C, and the material is extruded through an extrusion device, such as a twin-screw extruder or a single-screw extruder, at an extrusion temperature of 160-170°C, extruded, stretched, and pelletized to obtain thermoplastic vulcanized rubber material particles.

[0070] 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 vulcanized rubber material described above.

[0071] In a fourth aspect, the present invention provides a method for preparing the above-mentioned liquid cooling tube, the method comprising the following steps:

[0072] The raw materials are mixed evenly, wherein the raw materials include the modified thermoplastic vulcanized rubber and the modified boron nitride, and extruded, drawn and pelletized by an extrusion device to obtain thermoplastic vulcanized rubber material particles;

[0073] The thermoplastic vulcanized rubber material particles obtained above are extruded into a pipe through an extruder to obtain the liquid cooling pipe;

[0074] Wherein, the extrusion equipment is a twin-screw extruder, and the extrusion temperature of the extrusion equipment is 160-170°C; the extruder is a single-screw extruder, and the extrusion temperature of the extruder is 160-180°C.

[0075] It can be understood that the raw materials are mixed evenly in a high-speed mixer, the raw materials include modified thermoplastic vulcanized rubber, modified boron nitride, and may also include at least one of an antioxidant and an anti-copper agent, the high-speed mixer is set to a speed of <600Rpm, the material temperature is controlled to be lower than 60°C, and the thermoplastic vulcanized rubber material particles are obtained by extrusion, drawing, and pelletizing through an extruder, such as a twin-screw extruder, a single-screw extruder, and an extrusion temperature of 160-170°C. The obtained thermoplastic vulcanized rubber material particles are extruded through an extruder, such as a single-screw extruder, at an extrusion temperature of 160-180°C, and a pipe is extruded to obtain the 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, this embodiment includes the following raw materials in parts by weight:

[0083] Modified thermoplastic vulcanized rubber 70 parts,

[0084] 30 parts of modified boron nitride,

[0085] Antioxidant 10101 parts,

[0086] 0.2 parts of diethylamine,

[0087] The preparation process is as follows:

[0088] Preparation of modified thermoplastic vulcanizate

[0089] Prepare 1 part by weight of potassium permanganate and 100 parts by weight of TPV raw materials. In a reactor, dissolve potassium permanganate in deionized water to prepare a 0.5wt% solution. Add sulfuric acid to adjust the solution pH to 1. Add TPV to the potassium permanganate solution, turn on the agitator, and heat to 65°C. React for 3.5 hours. Separate the modified TPV from the liquid by filtration, rinse with deionized water until no potassium permanganate residue is detected in the washing liquid. Dry the modified TPV in a hot air oven at 105°C for 2 hours to obtain hydroxylated TPV, i.e., modified thermoplastic vulcanizate.

[0090] Preparation of modified boron nitride

[0091] Prepare 1 part by weight of a silane coupling agent N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane and 100 parts by weight of boron nitride powder, prepare the silane coupling agent into an ethanol solution with a mass fraction of 1%, use hydrochloric acid to adjust the pH of the solution to 5, and wait for the silane coupling agent to be completely hydrolyzed; add the boron nitride powder to anhydrous ethanol to form a suspension with a solid-liquid ratio of 1:10, place the suspension in an ultrasonic cleaner and disperse it for 25 minutes until there is no obvious agglomerated powder; add the boron nitride suspension to the hydrolyzed silane coupling agent solution, stir continuously at 70°C for 3 hours at a stirring speed of 400Rpm, filter, wash and dry the reacted solution to obtain boron nitride modified with a silane coupling agent.

[0092] Preparation of Thermoplastic Vulcanized Rubber Materials

[0093] 70 parts by weight of the modified thermoplastic vulcanized rubber, 30 parts by weight of modified boron nitride, 1 part by weight of antioxidant 1010, and 0.2 parts by weight of diethylamine prepared above were placed in a high-speed mixer according to a weight ratio and mixed evenly. The speed of the high-speed mixer was set to 550 Rpm, the material temperature was controlled to be lower than 60°C, and the total mixing time was 12 minutes. The uniformly mixed raw materials were extruded and granulated by a twin-screw extruder, the extrusion temperature was set to 160°C-170°C, and the screw speed adjustment range was 160-200 Rpm to obtain thermoplastic vulcanized rubber material particles.

[0094] Preparation of liquid cooling tube

[0095] The thermoplastic vulcanized rubber 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 water-cooled and shaped to obtain the liquid-cooled tube. The tube has a good appearance and is free from surface defects such as fish scales, particles, and collapse.

[0096] Embodiment 2:

[0097] Please refer to Table 1, this embodiment includes the following raw materials in parts by weight:

[0098] Modified thermoplastic vulcanized rubber 65 parts,

[0099] 35 parts of modified boron nitride,

[0100] Antioxidant 10101 parts,

[0101] 0.2 parts of diethylamine,

[0102] The preparation process is as follows:

[0103] Preparation of modified thermoplastic vulcanizate

[0104] Prepare 1 part by weight of potassium permanganate and 100 parts by weight of TPV raw materials. In a reactor, dissolve potassium permanganate in deionized water to prepare a 0.5wt% solution. Add sulfuric acid to adjust the solution pH to 1. Add TPV to the potassium permanganate solution, turn on the agitator, and heat to 65°C. React for 3.5 hours. Separate the modified TPV from the liquid by filtration, rinse with deionized water until no potassium permanganate residue is detected in the washing liquid. Dry the modified TPV in a hot air oven at 105°C for 2 hours to obtain hydroxylated TPV, i.e., modified thermoplastic vulcanizate.

[0105] Preparation of modified boron nitride

[0106] Prepare 1 part by weight of a silane coupling agent N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane and 100 parts by weight of boron nitride powder, prepare the silane coupling agent into an ethanol solution with a mass fraction of 1%, use hydrochloric acid to adjust the pH of the solution to 5, and wait for the silane coupling agent to be completely hydrolyzed; add the boron nitride powder to anhydrous ethanol to form a suspension with a solid-liquid ratio of 1:10, place the suspension in an ultrasonic cleaner and disperse it for 25 minutes until there is no obvious agglomerated powder; add the boron nitride suspension to the hydrolyzed silane coupling agent solution, stir continuously at 70°C for 3 hours at a stirring speed of 400Rpm, filter, wash and dry the reacted solution to obtain boron nitride modified with a silane coupling agent.

[0107] Preparation of Thermoplastic Vulcanized Rubber Materials

[0108] 65 parts by weight of the modified thermoplastic vulcanized rubber, 35 parts by weight of modified boron nitride, 1 part by weight of antioxidant 1010, and 0.2 parts by weight of diethylamine prepared above were placed in a high-speed mixer according to a weight ratio and mixed evenly. The speed of the high-speed mixer was set to 550 Rpm, the material temperature was controlled to be lower than 60°C, and the total mixing time was 12 minutes. The uniformly mixed raw materials were extruded and granulated by a twin-screw extruder, the extrusion temperature was set to 160°C-170°C, and the screw speed adjustment range was 160-200 Rpm to obtain thermoplastic vulcanized rubber material particles.

[0109] Preparation of liquid cooling tube

[0110] The thermoplastic vulcanized rubber 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 water-cooled and shaped to obtain the liquid-cooled tube. The tube has a good appearance and is free from surface defects such as fish scales, particles, and collapse.

[0111] Embodiment 3:

[0112] Please refer to Table 1, this embodiment includes the following raw materials in parts by weight:

[0113] Modified thermoplastic vulcanized rubber 68 parts,

[0114] 32 parts of modified boron nitride,

[0115] Antioxidant 10101 parts,

[0116] 0.2 parts of diethylamine,

[0117] The preparation process is as follows:

[0118] Preparation of modified thermoplastic vulcanizate

[0119] Prepare 1 part by weight of potassium permanganate and 100 parts by weight of TPV raw materials. In a reactor, dissolve potassium permanganate in deionized water to prepare a 0.5wt% solution. Add sulfuric acid to adjust the solution pH to 1. Add TPV to the potassium permanganate solution, turn on the agitator, and heat to 65°C. React for 3.5 hours. Separate the modified TPV from the liquid by filtration, rinse with deionized water until no potassium permanganate residue is detected in the washing liquid. Dry the modified TPV in a hot air oven at 105°C for 2 hours to obtain hydroxylated TPV, i.e., modified thermoplastic vulcanizate.

[0120] Preparation of modified boron nitride

[0121] Prepare 1 part by weight of a silane coupling agent N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane and 100 parts by weight of boron nitride powder, prepare the silane coupling agent into an ethanol solution with a mass fraction of 1%, use hydrochloric acid to adjust the pH of the solution to 5, and wait for the silane coupling agent to be completely hydrolyzed; add the boron nitride powder to anhydrous ethanol to form a suspension with a solid-liquid ratio of 1:10, place the suspension in an ultrasonic cleaner and disperse it for 25 minutes until there is no obvious agglomerated powder; add the boron nitride suspension to the hydrolyzed silane coupling agent solution, stir continuously at 70°C for 3 hours at a stirring speed of 400Rpm, filter, wash and dry the reacted solution to obtain boron nitride modified with a silane coupling agent.

[0122] Preparation of Thermoplastic Vulcanized Rubber Materials

[0123] 68 parts by weight of the modified thermoplastic vulcanized rubber, 32 parts by weight of modified boron nitride, 1 part by weight of antioxidant 1010, and 0.2 parts by weight of diethylamine prepared above were placed in a high-speed mixer according to a weight ratio and mixed evenly. The speed of the high-speed mixer was set to 550 Rpm, the material temperature was controlled to be lower than 60°C, and the total mixing time was 12 minutes. The uniformly mixed raw materials were extruded and granulated by a twin-screw extruder, the extrusion temperature was set to 160°C-170°C, and the screw speed adjustment range was 160-200 Rpm to obtain thermoplastic vulcanized rubber material particles.

[0124] Preparation of liquid cooling tube

[0125] The thermoplastic vulcanized rubber 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 water-cooled and shaped to obtain the liquid-cooled tube. The tube has a good appearance and is free from surface defects such as fish scales, particles, and collapse.

[0126] Comparative Example 1:

[0127] Please refer to Table 1. This comparative example is similar to Example 1, except that the thermoplastic vulcanized rubber is not modified. The prepared liquid cooling tube has a good appearance and has no surface defects such as fish scales, particles, and collapse. Comparative Example 2:

[0128] Please refer to Table 1. This comparative example is similar to Example 1, except that the boron nitride is not modified.

[0129] The inner surface of the prepared liquid cooling tube is smooth and flat, and the outer surface is smooth but undulating.

[0130] Comparative Example 3:

[0131] Please refer to Table 1, this comparative example includes the following raw materials in parts by weight:

[0132] Modified thermoplastic vulcanized rubber 55 parts, (65-70)

[0133] Modified boron nitride 45 parts, (30-35)

[0134] Antioxidant 10101 parts, (0.5-2)

[0135] 0.2 parts of diethylamine, (0.1-1)

[0136] The preparation process is the same as that of Example 1, except that the weight fractions of the components are different.

[0137] The inner surface of the prepared liquid cooling tube is rough and the outer surface has fish scale patterns.

[0138] Comparative Example 4:

[0139] Please refer to Table 1, this comparative example includes the following raw materials in parts by weight:

[0140] Modified thermoplastic vulcanized rubber 80 parts, (65-70)

[0141] Modified boron nitride 20 parts, (30-35)

[0142] Antioxidant 10101 parts, (0.5-2)

[0143] 0.2 parts of diethylamine, (0.1-1)

[0144] The preparation process is the same as that of Example 1, except that the weight fractions of the components are different.

[0145] The prepared liquid cooling tube is in the shape of a bamboo joint.

[0146] The thermoplastic vulcanized rubber materials obtained in the above examples and comparative examples were injection molded or molded, and thermal conductivity, trouser tear, breaking strength, elongation at break, flexural modulus, and melt index were measured. The test standards are as follows:

[0147] (1) Thermal conductivity

[0148] 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). The thermal conductivity of three samples was tested and the results were averaged.

[0149] (2) Pants-shaped tear

[0150] 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.

[0151] (3) Breaking strength and breaking elongation

[0152] 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 micro-controlled electronic universal material tensile machine of Dongguan High-speed Railway Testing Co., Ltd. was used to test the fracture strength and elongation of three specimens, and the results were averaged.

[0153] (4) Flexural modulus

[0154] According to GB / T 9341-2008, rectangular specimens with length, width and thickness of 100×15×5mm are prepared from the plastic material to be tested according to the standard requirements. The surface of the specimen is flat, free of bubbles, cracks and other defects, and the two end faces should be parallel and perpendicular to the side. The specimen is placed on the bending test fixture to ensure that the center of the specimen is aligned with the center of the loading pressure head or the support roller. The loading speed is 5mm / min. The micro-controlled electronic universal material tensile machine of Dongguan High-speed Railway Testing Co., Ltd. is used for testing. The arithmetic mean of the bending modulus of a group of specimens is taken as the test result. A group contains at least three groups of valid test results.

[0155] (5) Melt index

[0156] According to GB / T 3682.1-2018, a Goettfert Mi2 melt flow rate meter was used for the test. The heating furnace of the melt flow rate meter was heated to the set temperature (230°C). When the temperature reached the set value and stabilized, the pre-dried sample was quickly loaded into the barrel with a sample weight of 6 grams. Then the piston rod was placed and preheated for 5 minutes without load to allow the sample to be evenly heated and melted in the barrel. After the preheating was completed, the specified load (2.16 kg) was quickly added. The sample began to extrude from the die under the load. When the extrudate was a continuous and uniform thin stream, the extrudate was cut off with a cutter and the extrudate was collected. The extrudate was collected at a certain time interval (such as 30 seconds or 60 seconds). At least three consecutive segments were collected and the mass of each segment was accurately weighed with a balance. Melt mass flow rate (MFR): The calculation formula is MFR = m / t × 600, where m is the average value of the cut mass (g), t is the time interval for collecting the cuts (s), and the result unit is g / 10min. Test the melt index of 3 samples and take the average value of the results.

[0157] The test results are shown in Table 2.

[0158] Table 2 Performance test table of the embodiments of the present invention and comparative examples

[0159]

[0160] According to Table 2, the thermal conductivity of the TPV injection molded sheets of Examples 1-3 is greater than 1W / (m K), the thermal conductivity is good, the trouser tear is greater than 50kN / m, the tear resistance is excellent, the breaking strength is greater than 10MPa, the elongation at break is greater than 450%, the resistance to fracture and plasticity are excellent, the bending modulus is greater than 200MPa, the resistance to deformation is excellent, the overall mechanical properties are excellent, the melt index is between 10-15g / 10min, the extruded pipe has a good appearance, and there are no fish scales, particles, collapse and other surface defects, which shows that the thermoplastic vulcanized rubber material of the present invention has both good thermal conductivity and excellent mechanical properties, is suitable for preparation into liquid cooling pipes, and has broad application prospects in the field of liquid cooling charging guns. It can be seen from Example 1 and Comparative Example 1 that the thermal conductivity, trouser tear, breaking strength, elongation at break, and bending modulus of the TPV injection molded sheet are greatly reduced without modifying the thermoplastic vulcanized rubber, indicating that the thermal conductivity and mechanical properties of the material are both reduced. It can be seen from Example 1 and Comparative Example 2 that the thermal conductivity, trouser tear, breaking strength, elongation at break, bending modulus, and melt index of the TPV injection molded sheet are greatly reduced without modification of boron nitride, indicating that the thermal conductivity and mechanical properties of the material are both reduced, and the material extruded pipe has certain apparent defects. It can be seen from Example 1 and Comparative Example 3 that the amount of modified thermoplastic vulcanized rubber is too low and the amount of modified boron nitride is too high. Although the thermal conductivity of the TPV injection molded sheet is improved, the trouser tear, breaking strength, elongation at break, bending modulus, and melt index are all reduced, indicating that although the thermal conductivity of the material is improved, the mechanical properties are reduced, and the material extruded pipe has certain apparent defects. It can be seen from Example 1 and Comparative Example 4 that the amount of modified thermoplastic vulcanized rubber is too high, the amount of modified boron nitride is too low, the thermal conductivity of the TPV injection molded sheet is greatly reduced, the trouser tear and bending modulus are reduced, the breaking strength, elongation at break, and melt index are all increased, indicating that the thermal conductivity of the material is greatly reduced, the tear resistance and deformation resistance are reduced, the fracture resistance and plasticity are increased, and the extruded pipe of the material has certain apparent defects.

[0161] 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 vulcanized rubber material, characterized in that: The raw materials of the thermoplastic vulcanized rubber material include, by weight: Modified thermoplastic vulcanized rubber 65-70 parts, 30-35 parts of modified boron nitride, Wherein, the modified thermoplastic vulcanized rubber is hydroxylated thermoplastic vulcanized rubber, and the modified boron nitride is boron nitride modified by a silane coupling agent.

2. The thermoplastic vulcanized rubber material according to claim 1, characterized in that The preparation method of the hydroxylated thermoplastic vulcanizate comprises the following steps: Sulfuric acid is added to the potassium permanganate aqueous solution to adjust the pH to 0.9-1.1, and then the thermoplastic vulcanized rubber powder is added, stirred, heated to 60-70° C., reacted for 2.0-4.0 hours, and filtered to obtain the hydroxylated thermoplastic vulcanized rubber.

3. The thermoplastic vulcanized rubber material according to claim 2, characterized in that: The weight ratio of the potassium permanganate to the thermoplastic vulcanized rubber is (1:50)-(1:100).

4. The thermoplastic vulcanized rubber material according to claim 1, characterized in that: The preparation method of the silane coupling agent modified boron nitride comprises the following steps: A silane coupling agent and an organic solvent are prepared into a silane coupling agent organic solution in a weight ratio of (0.5:100) to (5:100), the pH of the silane coupling agent organic solution is adjusted to 3-5, and stirred to obtain a hydrolyzed silane coupling agent solution; The boron nitride and the organic solvent are prepared into a boron nitride suspension in a weight ratio of (1:10) to (1:15); Adding the boron nitride suspension to the hydrolyzed silane coupling agent solution, stirring and reacting at 65-75° C. for 2-4 hours, filtering, washing and drying the solution after the reaction to obtain boron nitride modified with a silane coupling agent; Wherein, the organic solvent is at least one of ethanol, isopropanol, n-propanol, cyclohexanone and acetone.

5. The thermoplastic vulcanized rubber material according to claim 1, characterized in that: The silane coupling agent is at least one of N-(β-aminoethyl)-γ-aminopropyltrimethoxysilane and N-(β-aminoethyl)-γ-aminopropylmethyldimethoxysilane; And / or, the boron nitride is hexagonal boron nitride with a particle size range of 3-10 μm; And / or, the weight ratio of the silane coupling agent to the boron nitride is (0.5:100)-(1:100).

6. The thermoplastic vulcanizate according to claim 1, characterized in that: The melt index of the thermoplastic vulcanized rubber is 15-17 g / 10 min at 230° C. and 2.16 kg.

7. The thermoplastic vulcanizate according to claim 1, characterized in that: The thermoplastic vulcanized rubber material further comprises: at least one of an antioxidant and an anti-copper agent; wherein, based on the weight of the raw materials, the antioxidant comprises 0.5-2 parts, and the anti-copper agent comprises 0.1-1 parts.

8. The thermoplastic vulcanizate according to claim 7, characterized in that The antioxidant is at least one of an amine antioxidant, an imine antioxidant, a thio antioxidant, and a phosphite antioxidant; the anti-copper agent is at least one of an azole anti-copper agent, a thiophene anti-copper agent, and a hydrazine anti-copper agent; And / or, the antioxidant is at least one of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl) propionate and tris(2,4-di-tert-butylphenyl) phosphite; the anti-copper agent is at least one of benzotriazole and its derivatives, mercaptobenzothiazole and its derivatives, octadecylamine, and diethylamine.

9. A method for preparing a thermoplastic vulcanized rubber material according to any one of claims 1 to 8, characterized in that: The preparation method comprises the following steps: The raw materials are mixed evenly, wherein the raw materials include the modified thermoplastic vulcanized rubber and the modified boron nitride, and extruded, drawn and pelletized by an extrusion device to obtain thermoplastic vulcanized rubber material particles; Wherein, the extrusion temperature of the extrusion equipment is 160-170°C.

10. 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.

11. A method for preparing a liquid cooling tube as claimed in claim 10, characterized in that: The preparation method comprises the following steps: The raw materials are mixed evenly, wherein the raw materials include the modified thermoplastic vulcanized rubber and the modified boron nitride, and extruded, drawn and pelletized by an extrusion device to obtain thermoplastic vulcanized rubber material particles; The thermoplastic vulcanized rubber material particles obtained above are extruded into a pipe through an extruder to obtain the liquid cooling pipe; Wherein, the extrusion equipment is a twin-screw extruder, and the extrusion temperature of the extrusion equipment is 160-170°C; the extruder is a single-screw extruder, and the extrusion temperature of the extruder is 160-180°C.

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