High-temperature-resistant TPU (thermoplastic polyurethane) resin as well as preparation method and application thereof

Abstract

The invention provides high-temperature-resistant TPU (thermoplastic polyurethane) resin as well as a preparation method and application thereof. The high-temperature-resistant TPU resin is prepared from the following raw materials: A-type polyester polyol, B-type polyester polyol, diisocyanate, a chain extender and ceramic powder, the A-type polyester polyol comprises at least one of poly (butylene adipate) glycol, poly (butylene adipate) glycol, polycaprolactone polyol and polycarbonate polyol, and the B-type polyester polyol is polyester polyol obtained by carrying out polycondensation on bisphenol A and aliphatic dibasic acid with the carbon atom number being more than 8. The TPU resin not only has good tensile strength and elongation at break, but also has good high temperature resistance, the retention rate of tensile strength can reach 80% or above after 168 hours at 135 DEG C, and the TPU resin can be applied to the fields of high-temperature cable sheaths and the like.

Description

Technical Field

[0001] The present invention belongs to the technical field of fine chemical production, and relates to a high-temperature resistant TPU resin, its preparation method and application, and particularly relates to a high-temperature resistant TPU resin for cable sheaths and its preparation method. Background Art

[0002] High-temperature resistant cables, also known as special cables, are connecting wires designed specifically for high-temperature environments and are applicable to household appliances, electronic devices, temperature sensors, etc. Such cables possess excellent corrosion resistance and can resist the erosion of oil, strong acids, strong alkalis, and strong oxidants. They also have outstanding electrical insulation performance, are non-hygroscopic, and have a high insulation resistance, ensuring safe power transmission under high-temperature and humid conditions.

[0003] Commercially available general electric wires and cables, although using the commonly available conventional materials polyvinyl chloride and styrene as insulation sheaths, are easy to produce on a large scale and have a relatively low cost, but obviously cannot meet the requirements of high-temperature resistance, thus unable to ensure the safe operation of electricity and signals. Although other materials such as TPE specified in current standards have a very advantageous price, their temperature resistance grade is only 90°C.

[0004] Therefore, in this field, there is a desire to develop a TPU resin that not only has good high-temperature resistance but also simultaneously has excellent heat resistance, cold resistance, wear resistance, flexibility, and cold / heat resistance to meet the requirements of high-temperature resistant cable materials. Summary of the Invention

[0005] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a high-temperature resistant TPU resin, its preparation method and application. The high-temperature resistant TPU resin of the present invention not only has good high-temperature resistance but also simultaneously has excellent heat resistance, cold resistance, wear resistance, and flexibility, and is applicable to high-temperature resistant cable materials.

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

[0007] In a first aspect, the present invention provides a high-temperature resistant TPU resin. The raw materials for preparing the high-temperature resistant TPU resin include type A polyester polyol, type B polyester polyol, diisocyanate, chain extender, and ceramic powder; the type A polyester polyol includes at least one of polybutylene adipate glycol, polyethylene glycol butylene adipate glycol, polycaprolactone polyol, and polycarbonate polyol, and the type B polyester polyol is a polyester polyol obtained by polycondensation of bisphenol A and an aliphatic dicarboxylic acid with 8 or more carbon atoms.

[0008] In the present invention, through the synergistic effect of type A polyester polyol and type B polyester polyol, in combination with ceramic powder, not only can the high-temperature resistance of the TPU resin be improved, but also the mechanical properties and chemical resistance of the TPU resin can be enhanced; in the present invention, the type A polyester polyol is a polyester polyol with better heat resistance, and the type B polyester polyol is prepared from bisphenol A and an aliphatic dicarboxylic acid with 8 or more carbon atoms, so that it contains a large number of aromatic ring groups and a relatively long carbon chain, which has a good improvement in heat resistance.

[0009] Preferably, the type A polyester polyol includes polycarbonate diol (PCD).

[0010] Preferably, the number-average molecular weight of the type A polyester polyol is 1000-2000, such as 1000, 1500 or 2000, etc., preferably 1000.

[0011] Preferably, the number-average molecular weight of the type B polyester polyol is 1000-2000, such as 1000, 1500 or 2000, etc.

[0012] Preferably, the aliphatic dicarboxylic acid with 8 or more carbon atoms is an aliphatic dicarboxylic acid with 8-12 carbon atoms.

[0013] Preferably, the aliphatic dicarboxylic acid is selected from suberic acid or sebacic acid.

[0014] In the present invention, the type B polyester polyol is prepared by the following method:

[0015] Bisphenol A and an aliphatic dicarboxylic acid with 8 or more carbon atoms are subjected to a first esterification reaction, then the temperature is raised, and a second esterification reaction is continued. Then, a catalyst is added, the vacuum is pumped, and the temperature is raised for a polycondensation reaction to obtain the type B polyester polyol.

[0016] Preferably, the molar ratio of bisphenol A to the aliphatic dicarboxylic acid with 8 or more carbon atoms is (1.1-1.3):1, such as 1.1:1, 1.15:1, 1.18:1, 1.2:1, 1.25:1, 1.28:1 or 1.3:1.

[0017] Preferably, the temperature of the first esterification reaction is 180-190°C, such as 180°C, 183°C, 185°C, 188°C or 190°C, and the reaction time is 2.5-3.5 h, such as 2.5 h, 2.8 h, 3 h, 3.3 h or 3.5 h.

[0018] Preferably, the temperature of the second esterification reaction is 185-195°C, such as 185°C, 188°C, 190°C, 193°C or 195°C, and the reaction time is 3-5 h, such as 3 h, 3.5 h, 4 h, 4.5 h, 4.8 h or 5 h.

[0019] Preferably, the catalyst is selected from tin-based catalysts;

[0020] Preferably, the tin-based catalyst is selected from dibutyltin dilaurate or tin octoate;

[0021] Preferably, the temperature of the polycondensation reaction is 220-240 °C, such as 220 °C, 225 °C, 230 °C, 235 °C or 240 °C, and the reaction time is 3.5-4.5 h, such as 3.5 h, 3.8 h, 4 h or 4.5 h.

[0022] Preferably, the diisocyanate includes any one or a combination of at least two of 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate (HDI), 4,4'-dicyclohexylmethane diisocyanate (H12MDI), etc.

[0023] Preferably, the chain extender includes any one or a combination of at least two of ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol or hydroquinone bis(2-hydroxyethyl) ether, preferably 1,4-cyclohexanedimethanol. In the present invention, the chain extender preferably includes small molecule alcohols with a six-membered ring, which can further improve the heat resistance.

[0024] Preferably, the ceramic powder is nano-ceramic powder.

[0025] Preferably, the particle size of the nano-ceramic powder is less than 100 nm, such as 100 nm, 90 nm, 80 nm, 60 nm, 40 nm, 20 nm, 10 nm, etc.

[0026] Preferably, the raw materials for preparing the high-temperature resistant TPU resin further include additives.

[0027] Preferably, the additives include compound antioxidants.

[0028] Preferably, the compound antioxidant includes pentaerythritol tetra[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, and the mass ratio of the two is 1:1-1:2, such as 1:1, 1:1.2, 1:1.5, 1:1.8 or 1:2.

[0029] Preferably, the additives further include lubricants.

[0030] Preferably, the lubricant includes any one or a combination of at least two of stearamide, ethylene bisstearamide or polyethylene wax.

[0031] As a preferred technical solution, the raw materials for preparing the high-temperature resistant TPU resin according to the present invention include the following components by weight:

[0032]

[0033] In the present invention, in the preparation raw materials of the high-temperature resistant TPU resin, the dosage of the A-type polyester polyol can be 35 parts, 36 parts, 37 parts, 38 parts, 39 parts or 40 parts, etc.

[0034] In the present invention, in the preparation raw materials of the high-temperature resistant TPU resin, the dosage of the B-type polyester polyol can be 20 parts, 21 parts, 22 parts, 23 parts, 24 parts or 25 parts, etc.

[0035] In the present invention, in the preparation raw materials of the high-temperature resistant TPU resin, the dosage of the diisocyanate can be 30 parts, 31 parts, 32 parts, 33 parts, 34 parts or 35 parts, etc.

[0036] In the present invention, in the preparation raw materials of the high-temperature resistant TPU resin, the dosage of the chain extender can be 7 parts, 8 parts, 9 parts or 10 parts, etc.

[0037] In the present invention, in the preparation raw materials of the high-temperature resistant TPU resin, the dosage of the ceramic powder can be 2 parts, 3 parts or 4 parts, etc.

[0038] In the present invention, in the preparation raw materials of the high-temperature resistant TPU resin, the dosage of the auxiliary agent can be 0.3 parts, 0.35 parts, 0.4 parts, 0.45 parts or 0.5 parts.

[0039] In the present invention, the diisocyanate is slightly in excess, which can appropriately increase the crosslinking degree of the TPU resin to form a micro-network structure. In addition, a certain amount of nano-ceramic powder is added externally to further improve the heat resistance of the TPU.

[0040] Second, the present invention provides a preparation method of the high-temperature resistant TPU resin as described above, and the preparation method includes the following steps:

[0041] (1) Mix the A-type polyester polyol, the B-type polyester polyol and an optional auxiliary agent to obtain a mixed material;

[0042] (2) Inject the mixed material in step (1), the diisocyanate and the chain extender into a twin-screw extruder, extrude, pelletize and dry to obtain the high-temperature resistant TPU resin.

[0043] Preferably, the mixed materials in step (1) further include a catalyst.

[0044] Preferably, based on the total weight of the preparation raw materials of the high-temperature resistant TPU resin being 100%, the content of the catalyst is 30 - 120 ppm, such as 30 ppm, 50 ppm, 80 ppm, 100 ppm or 120 ppm, etc.

[0045] Preferably, the catalyst includes stannous octoate (T-9) or dibutyltin dilaurate.

[0046] Preferably, the temperature of the mixing in step (1) is 95 - 105 °C, such as 95 °C, 96 °C, 97 °C, 98 °C, 100 °C or 105 °C, etc.

[0047] Preferably, the temperature of the diisocyanate in step (2) is maintained at 40 - 50 °C before mixing, such as 40 °C, 45 °C or 50 °C, etc.

[0048] Preferably, the temperature of the chain extender in step (2) is maintained at 110 - 120 °C before mixing, such as 110 °C, 115 °C or 120 °C, etc.

[0049] Preferably, the screw speed of the twin-screw extruder in step (2) is 165 - 195 rpm, such as 165 rpm, 168 rpm, 170 rpm, 175 rpm, 180 rpm, 185 rpm, 190 rpm or 195 rpm, and the temperature range is 185 - 215 °C, such as 185 °C, 195 °C, 205 °C or 215 °C, etc.

[0050] In the present invention, the granulation in step (2) is underwater pelletizing.

[0051] Preferably, the drying in step (2) is carried out in a drying kettle.

[0052] Preferably, the temperature of the drying in step (2) is 80 - 100 °C, such as 80 °C, 90 °C or 100 °C, etc., and the drying time is 6 - 8 h, such as 6 h, 7 h or 8 h, etc.

[0053] In the third aspect, the present invention provides the application of the high-temperature resistant TPU resin described in the first aspect in a high-temperature resistant cable sheath.

[0054] In the present invention, the high-temperature resistance means that after high-temperature aging at 135 °C for 168 h, the tensile strength retention rate of the TPU resin can still reach more than 70%, and the loss does not exceed 30%.

[0055] Compared with the prior art, the present invention has the following beneficial effects:

[0056] In the present invention, through the synergistic effect of A-type polyester polyol and B-type hydroxyl-terminated polyester polyol, not only can the physical properties such as the elongation at break, abrasion resistance, and tensile strength of the TPU resin be improved, but also the high-temperature resistance of the TPU resin can be improved (tensile strength retention rate: 80% - 85% (135 °C, 168 h)). Detailed implementation manners

[0057] The technical solution of the present invention will be further described below through specific embodiments. Those skilled in the art should understand that the embodiments are only for helping to understand the present invention and should not be regarded as specific limitations on the present invention.

[0058] Preparation Example 1

[0059] In the present invention, the B-type polyester polyol is prepared by the following preparation method:

[0060] Bisphenol A and sebacic acid are added to a three-necked flask, and the molar ratio of the two is 1.2:1. Esterification reaction is carried out at 180 °C for 2.5 h, then the temperature is raised to 190 °C, and the esterification reaction is continued for 3 h. Then, 50 ppm of the catalyst dibutyltin dilaurate is added, the vacuum is pumped, and the temperature is slowly raised to 230 °C for polycondensation reaction for 4 h, thereby obtaining the B-type polyester polyol (number average molecular weight is 2000).

[0061] Preparation Example 2

[0062] The difference from Preparation Example 1 is that sebacic acid is replaced by suberic acid to prepare a B-type polyester polyol (number average molecular weight is 2000).

[0063] Comparative Preparation Example 1

[0064] The difference from Preparation Example 1 is that bisphenol A is replaced by bisphenol F, and the rest are the same as Preparation Example 1, to prepare a polyester polyol (number average molecular weight is 2000).

[0065] Comparative Preparation Example 2

[0066] The difference from Preparation Example 1 is that sebacic acid is replaced by adipic acid, and the rest are the same as Preparation Example 1, to prepare a polyester polyol (number average molecular weight is 2000).

[0067] Example 1

[0068] In this example, a high-temperature resistant TPU resin is provided. The raw materials for preparing the high-temperature resistant TPU resin include the following components by weight:

[0069]

[0070] Among them, the A-type polyester polyol is PCD, with a number average molecular weight of 1000 (Ube, Japan, UH100); the diisocyanate is MDI, the chain extender is CHDM; the antioxidant is a mixture of antioxidant 1010 and 1098 (the mass ratio of the two is 1:1).

[0071] The preparation method includes the following steps:

[0072] (1) Mix the formulated amount of polyester polyol of type A, polyester polyol of type B, compound antioxidant, and stannous octoate (the dosage of stannous octoate is 50 ppm based on the total weight of the raw materials for preparing the high-temperature resistant TPU resin being 100%) to obtain a mixed material;

[0073] (2) The B material tank is for diisocyanate, and the temperature is maintained at 50 °C; the C material tank is for chain extender, and the temperature is maintained at 50 °C; inject the mixed material in step (1), diisocyanate, and chain extender into the front end (casting machine port) of the twin-screw extruder, set the screw rotation speed of the extruder to 185 rpm, and the temperature to 200 °C. After underwater pelletization, dry in a drying kettle at 100 °C for 6 h to obtain the high-temperature resistant TPU resin.

[0074] Example 2

[0075] In this example, a high-temperature resistant TPU resin is provided. The raw materials for preparing the high-temperature resistant TPU resin, by weight, include the following components:

[0076]

[0077] Among them, the preparation method of the polyester polyol of type B is the same as that in Example 1; the polyester polyol of type A is PCD with a molecular weight of 1000; the diisocyanate is MDI, the chain extender is CHDM; the antioxidant is a mixture of antioxidant 1010 and 1098;

[0078] The preparation method includes the following steps:

[0079] (1) Mix the formulated amount of polyester polyol of type A, polyester polyol of type B, compound antioxidant, and stannous octoate (the dosage of stannous octoate is 30 ppm based on the total weight of the raw materials for preparing the high-temperature resistant TPU resin being 100%) to obtain a mixed material;

[0080] (2) The B material tank is for diisocyanate, and the temperature is maintained at 50 °C; the C material tank is for chain extender, and the temperature is maintained at 50 °C; inject the mixed material in step (1), diisocyanate, and chain extender into the front end (casting machine port) of the twin-screw extruder, set the screw rotation speed of the extruder to 185 rpm, and the temperature to 200 °C. After underwater pelletization, dry in a drying kettle at 100 °C for 6 h to obtain the high-temperature resistant TPU resin.

[0081] Example 3

[0082] In this example, a high-temperature resistant TPU resin is provided. The raw materials for preparing the high-temperature resistant TPU resin, by weight, include the following components:

[0083]

[0084] Among them, the preparation method of the B-type polyester polyol is the same as that in Example 1; the A-type polyester polyol is PCD with a molecular weight of 1000; the diisocyanate is MDI, the chain extender is CHDM; the antioxidant is a mixture of antioxidant 1010 and 1098;

[0085] The preparation method includes the following steps:

[0086] (1) Mix the formulated amounts of the A-type polyester polyol, B-type polyester polyol, compound antioxidant, and stannous octoate (the amount of stannous octoate is 100 ppm based on the total weight of the raw materials for preparing the high-temperature resistant TPU resin being 100%) to obtain a mixed material;

[0087] (2) The B material tank is for the diisocyanate, and the temperature is maintained at 50°C; the C material tank is for the chain extender, and the temperature is maintained at 50°C; inject the mixed material in step (1), the diisocyanate, and the chain extender into the front end (casting machine port) of the twin-screw extruder, set the screw speed of the extruder to 185 rpm, and the temperature to 200°C. After underwater pelletizing, dry in a drying kettle at 100°C for 6 h to obtain the high-temperature resistant TPU resin.

[0088] Example 4

[0089] The difference from Example 1 is only that the B-type polyester polyol is replaced with the B-type polyester polyol prepared in Preparation Example 2.

[0090] Comparative Example 1

[0091] The difference between this comparative example and Example 1 is only that the B-type polyester polyol is not included in the preparation raw materials, and the weight fraction of the A-type polyester polyol is 55 parts, and other conditions are the same as those in Example 1.

[0092] Comparative Example 2

[0093] The difference between this comparative example and Example 1 is only that the A-type polyester polyol is not included in the preparation raw materials, and the weight fraction of the B-type polyester polyol is 65 parts, and other conditions are the same as those in Example 1.

[0094] Comparative Example 3

[0095] The difference between this comparative example and Example 1 is only that the B-type polyester polyol in the preparation raw materials is replaced with the polyester polyol obtained in Comparative Preparation Example 1.

[0096] Comparative Example 4

[0097] The difference between this comparative example and Example 1 is only that the B-type polyester polyol in the preparation raw materials is replaced with the polyester polyol obtained in Comparative Preparation Example 2.

[0098] Perform performance tests on the high-temperature resistant TPU resins of Examples 1-8 and Comparative Examples 1-5, and the test methods are as follows:

[0099] (1) The hardness test was carried out according to the standard of GB / T531-2009;

[0100] (2) The mechanical property test was carried out according to the standard of GB / T528-2009;

[0101] (3) The high-temperature resistance test conditions were as follows: The injection molded specimen was placed in an oven at 135 °C and baked for 168 h, then placed at room temperature (25 °C) for 4 h, and then the tensile strength was tested. The calculation formula of the tensile strength retention rate is as follows, and the tensile strength retention rate was used as the evaluation standard for high-temperature resistance;

[0102]

[0103] The performance test results are shown in Table 1.

[0104] Table 1

[0105]

[0106] As can be seen from Table 1, the high-temperature resistant TPU resins prepared in Examples 1-2 of the present invention all have excellent high-temperature resistance (the tensile strength retention rate reaches more than 80%), the hardness is 86-87 ShA, and they have good mechanical properties.

[0107] Compared with Example 1, since the B-type polyester polyol was not added, the high-temperature resistance of the TPU resin provided by Comparative Example 1 was significantly reduced. This is because the B-type polyester polyol contains a large number of aromatic rings, which can provide a certain degree of heat resistance.

[0108] Compared with Example 1, since the A-type polyester polyol was not added, the high-temperature resistance of the TPU resin provided by Comparative Example 1 was significantly reduced. This is because the B-type polyester polyol contains a large number of ester groups, which can improve the crystallinity of TPU, and thus improve the heat resistance of TPU. In Comparative Example 2, since the A-type polyester polyol was not added, the crystallinity of the overall system was reduced, and thus the heat resistance was affected. In Comparative Example 3, since the polyester polyol obtained from Comparative Preparation Example 1 was used, and bisphenol F has an asymmetric structure, which affects the overall regularity of the polyester polyol, resulting in a decrease in the heat resistance of the synthesized TPU. In Comparative Example 4, since the polyester polyol obtained from Comparative Preparation Example 2 was used, and adipic acid with a shorter carbon chain was used as the raw material when synthesizing the polyol, it would lead to a decrease in the heat resistance of the polyester polyol, thus affecting the heat resistance of TPU.

[0109] The applicant declares that the present invention uses the above embodiments to illustrate the high-temperature resistant TPU resin, its preparation method and application, but the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvement to the present invention, the equivalent substitution of each raw material of the present invention's products, the addition of auxiliary components, the selection of specific methods, etc. all fall within the protection scope and the disclosure scope of the present invention.

Claims

1. A heat-resistant TPU resin, characterized in that, The raw materials for preparing the high temperature resistant TPU resin include type A polyester polyol, type B polyester polyol, diisocyanate, chain extender and ceramic powder; the type A polyester polyol includes at least one of polybutylene adipate diol, polyethylene adipate diol, polycaprolactone polyol and polycarbonate polyol, and the type B polyester polyol is a polyester polyol obtained by condensation polymerization of bisphenol A and an aliphatic dibasic acid having 8 or more carbon atoms.

2. The high-temperature resistant TPU resin according to claim 1, characterized in that, The type A polyester polyol is polycarbonate diol; Preferably, the number average molecular weight of the type A polyester polyol is 1000-2000.

3. The high-temperature resistant TPU resin according to claim 1 or 2, characterized in that, The number average molecular weight of the B-type polyester polyol is 1000-2000; Preferably, the aliphatic dibasic acid having 8 or more carbon atoms is an aliphatic dibasic acid having 8-12 carbon atoms; Preferably, the aliphatic dibasic acid is selected from suberic acid or sebacic acid; Preferably, the B-type polyester polyol is prepared by the following method: Preferably, bisphenol A is subjected to a first esterification reaction with an aliphatic dibasic acid having 8 or more carbon atoms, and then the temperature is raised to continue the second esterification reaction, and then a catalyst is added, vacuum is drawn, and the temperature is raised to carry out a polycondensation reaction to obtain the type B polyester polyol; Preferably, the molar ratio of bisphenol A to the aliphatic dibasic acid having 8 or more carbon atoms is (1.1-1.3):1; Preferably, the temperature of the first esterification reaction is 180-190° C., and the reaction time is 2.5-3.5 h. Preferably, the temperature of the second esterification reaction is 185-195°C, and the reaction time is 3-5h; Preferably, the catalyst is selected from tin catalysts; Preferably, the tin catalyst is selected from dibutyltin dilaurate or tin isooctanoate; Preferably, the temperature of the polycondensation reaction is 220-240° C., and the reaction time is 3.5-4.5 hours.

4. The high-temperature resistant TPU resin according to any one of claims 1-3, characterized in that, The diisocyanate includes any one of 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate or 4,4'-dicyclohexylmethane diisocyanate or a combination of at least two thereof; Preferably, the chain extender includes any one of ethylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol or hydroquinone dihydroxyethyl ether, or a combination of at least two thereof, preferably 1,4-cyclohexanedimethanol. Preferably, the ceramic powder is nano ceramic powder; Preferably, the particle size of the nano-ceramic powder is less than 100 nm; Preferably, the raw materials for preparing the high temperature resistant TPU resin further include auxiliary agents; Preferably, the auxiliary agent includes a compound antioxidant; Preferably, the composite antioxidant comprises pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and N,N'-bis-(3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionyl)hexanediamine, and the mass ratio of the two is 1:1 to 1:2; Preferably, the auxiliary agent also includes a lubricant; Preferably, the lubricant includes any one of stearamide, ethylene bisstearamide or polyethylene wax, or a combination of at least two thereof.

5. The high-temperature resistant TPU resin according to any one of claims 1-4, characterized in that, The raw materials for preparing the high temperature resistant TPU resin include the following components in parts by weight:

6. The preparation method of the high-temperature resistant TPU resin according to any one of claims 1-5, characterized in that, The preparation method comprises the following steps: (1) Mix an A-type polyester polyol, a B-type polyester polyol and an optional auxiliary agent to obtain a mixed material; (2) Inject the mixed material obtained in step (1), a diisocyanate and a chain extender into a twin-screw extruder, extrude, pelletize and dry to obtain the high-temperature resistant TPU resin.

7. The preparation method according to claim 6, characterized in that, The materials mixed in step (1) further include a catalyst; Preferably, based on the total weight of the raw materials for preparing the high-temperature resistant TPU resin being 100%, the content of the catalyst is 30-120 ppm; Preferably, the catalyst includes stannous octoate or dibutyltin dilaurate; Preferably, the temperature of the mixing in step (1) is 95-105 °C.

8. The preparation method according to claim 6, wherein The temperature of the diisocyanate in step (2) is maintained at 40-50 °C before mixing; Preferably, the temperature of the chain extender in step (2) is maintained at 110-120 °C before mixing.

9. The preparation method according to claim 6, characterized in that, The screw speed of the twin-screw extruder in step (2) is 165-195 rpm, and the temperature range is 185-215 °C; Preferably, the drying in step (2) is carried out in a drying kettle; Preferably, the temperature of the drying in step (2) is 80-100 °C.

10. Application of the high-temperature resistant TPU resin according to claims 1 - in a high-temperature resistant cable sheath.

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