High-performance TPU for intelligent AGV wheels and preparation method of high-performance TPU

Abstract

The invention belongs to the technical field of TPU and preparation thereof, and particularly relates to high-performance TPU for intelligent AGV wheels and a preparation method of the high-performance TPU. The high-performance TPU for the intelligent AGV wheel, disclosed by the invention, is prepared from the following raw materials in parts by weight: 50 to 64.3 parts of poly epsilon-caprolactone dihydric alcohol; 28.3 to 40 parts of diisocyanate; 7.4 to 10 parts of a chain extender; 0.2 to 0.5 part of silicon carbide; 0.5-2 parts of an antistatic agent; 0.3-1 part of a hydrolysis stabilizer; 0.5-1 part of a catalyst; the number average molecular weight of the poly (epsilon-caprolactone) dihydric alcohol is 1500 to 2000. The high-performance TPU for the intelligent AGV wheel provided by the invention has the characteristics of high wear resistance, tear resistance, good elasticity, low permanent compression deformation and low internal heat generation, meanwhile, the antistatic performance is improved, and the invention further provides a preparation method of the high-performance TPU for the intelligent AGV wheel, and the preparation method is simple and easy to implement.

Description

Technical Field

[0001] The present invention belongs to the technical field of TPU and its preparation, and specifically relates to a high-performance TPU for intelligent AGV wheels and a preparation method thereof. Background Art

[0002] AGV is the abbreviation of Automated Guided Vehicle. It is a battery-powered unmanned vehicle equipped with a non-contact guidance device. Its main function is to accurately run to the designated location to perform a series of operations under computer monitoring according to path planning and operation requirements. AGV can be widely used in machinery, electronics, chemical industry, metallurgy, post and telecommunications, docks, airports and other industries. However, due to the influence of the working environment, AGV wheels have higher requirements on the material's bearing capacity, failure rate and service life.

[0003] Thermoplastic polyurethane elastomer (TPU) is a high-performance polymer synthetic material with a wide hardness range. It has the elasticity of rubber and the hardness of plastic. It also has the advantages of good resilience, easy processing, resistance to bending fatigue, wear resistance, and dimensional stability. In particular, polycaprolactone TPU has high mechanical properties and excellent solvent resistance, making it an ideal caster material. However, TPU performs poorly in terms of dynamic load-bearing capacity, heat resistance, antistatic properties, and compression deformation, which limits its further application in smart AGV wheels.

[0004] CN221250397U discloses an anti-skid and anti-static caster, comprising an inner wheel body, a transmission shaft connection, and an outer wheel body, wherein the outer wheel body with anti-static function is made of a composite material, and the composite material mainly comprises nylon and an antistatic agent. The composite material made of nylon and the antistatic agent has good anti-static performance, and nylon has high mechanical strength, is tensile and compressive resistant, and is resistant to weak acids, gasoline, and engine oil, but is not resistant to strong acids and alkalis and oxidants, has high hardness, poor elasticity, and generates loud noise during operation. Summary of the invention

[0005] The technical problem to be solved by the present invention is to overcome the above-mentioned defects of the prior art and provide a high-performance TPU for smart AGV wheels, which has the characteristics of high wear resistance, tear resistance, good elasticity, low permanent compression deformation, and low endogenous heat, while improving the antistatic performance; the present invention also provides a preparation method thereof, which is simple and easy.

[0006] The high-performance TPU for the intelligent AGV wheel of the present invention comprises the following raw materials in parts by weight: Diisocyanate: 28.3-40 parts; Poly-ε-caprolactone diol: 50-64.3 parts; Chain extender: 7.4-10 parts; Silicon carbide: 0.2-0.5 parts; Antistatic agent: 0.5-2 parts; Hydrolysis stabilizer: 0.3-1 part; Catalyst: 0.5-1 part; The poly-ε-caprolactone diol has a number average molecular weight of 1500-2000.

[0007] The diisocyanate is a mixture of one of 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate and 1,5-naphthalene diisocyanate, and the mass fraction of 1,5-naphthalene diisocyanate in the mixed diisocyanate is 20%-50%.

[0008] The chain extender is a mixture of 1,4-butanediol and trimethylolpropane, and the mass fraction of trimethylolpropane in the mixed chain extender is 5%-10%.

[0009] The silicon carbide has an average particle size of 20-50 μm, a purity of ≥99wt%, and is in powder form.

[0010] The antistatic agent is propyl trimethyl ammonium methyl sulfate (3-laurylamide), preferably Cyastat ® -LS.

[0011] The hydrolysis stabilizer is one of monomeric carbodiimide or polycarbodiimide, and the monomeric carbodiimide is preferably HyMax ® 1010, polycarbodiimide is preferably Stabaxol P 200.

[0012] The catalyst is one of dibutyltin dilaurate and stannous octoate.

[0013] The method for preparing the high-performance TPU for the intelligent AGV wheel comprises the following steps: (1) Mixing poly-ε-caprolactone diol and a chain extender, then adding an antistatic agent and a hydrolysis stabilizer and stirring at 80-110° C. to obtain a premix; (2) adding diisocyanate and catalyst into storage tank A, adding the premix of step (1) into storage tank B, mixing the materials in storage tank A and storage tank B, dehydrating under vacuum under stirring conditions, and pumping into a twin-screw extruder; (3) Add silicon carbide to the second zone of the screw, react in a twin-screw extruder at 110-180°C, and granulate to obtain high-performance TPU for smart AGV wheels.

[0014] In the step (2), the stirring rate is 400-800 r / min, and the vacuum dehydration temperature is 90-120°C.

[0015] In the step (3), the feeding section temperature of the twin-screw extruder is 110-120°C, the mixing section temperature is 130-150°C, the extrusion section temperature is 170-180°C, and the die head temperature is 150-160°C.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) The high-performance TPU for the intelligent AGV wheel of the present invention mixes 1,5-naphthalene diisocyanate and other diisocyanates, giving TPU excellent mechanical properties, with a tensile strength of more than 49 MPa and a tear strength of more than 128 kN / m. The tensile strength is significantly improved compared to the traditional TPU strength, and the DIN abrasion is reduced to 20 mm. 3 the following.

[0017] (2) The high-performance TPU for the intelligent AGV wheel of the present invention adopts a mixed method of multiple chain extenders, and introduces branched alcohols on the basis of small molecule alcohols to improve the crosslinking degree of TPU, so that it has lower permanent compression deformation and heat resistance.

[0018] (3) The high-performance TPU for the intelligent AGV wheel of the present invention further improves the heat resistance and antistatic properties of the product by introducing high thermal conductivity material silicon carbide and antistatic agent. By mixing isocyanate and chain extender, the final fatigue temperature rise of the product is reduced by more than 70%, and the surface resistance is increased to 4×10 8 Ω.

[0019] (4) The preparation method of the high-performance TPU for the intelligent AGV wheel of the present invention has simple process and convenient operation. DETAILED DESCRIPTION

[0020] The present invention is further described below in conjunction with specific examples and comparative examples. The raw materials used in the examples and comparative examples are conventional commercially available raw materials unless otherwise specified, and the process methods used in the examples and comparative examples are conventional methods in the art unless otherwise specified.

[0021] The raw materials used in the embodiments and comparative examples are described as follows: Silicon carbide: average particle size 20-50 μm, purity ≥ 99 wt%, commercially available from Shanghai Baishun Biotechnology Co., Ltd. Antistatic agent Cyastat ® -LS: American ACC Company; Monomeric carbodiimide HyMax ® 1010: Shanghai Langyi Functional Materials Co., Ltd.; Polycarbodiimide Stabaxol P 200: LANXESS Chemical (China) Co., Ltd.

[0022] The following weight parts are all calculated according to the same mass unit.

[0023] The method for preparing the high-performance TPU for the intelligent AGV wheel comprises the following steps: (1) Mixing poly-ε-caprolactone diol and two chain extenders, then adding an electrostatic agent and a hydrolysis stabilizer and stirring at 80-110° C. to obtain a premix; (2) adding diisocyanate and catalyst into storage tank A, adding the premix of step (1) into storage tank B, mixing the materials in storage tank A and storage tank B, dehydrating under vacuum at 90-120° C. under stirring conditions of 400-800 r / min, and injecting into a twin-screw extruder; (3) Silicon carbide is added to the second zone of the screw through an external device and reacted in a twin-screw extruder. The feeding section temperature of the twin-screw extruder is 110-120°C, the mixing section temperature is 130-150°C, the extrusion section temperature is 170-180°C, and the head temperature is 150-160°C. The high-performance TPU for smart AGV wheels is obtained by granulation.

[0024] Example 1 The high-performance TPU for the intelligent AGV wheel includes the following raw materials in parts by weight: 4,4'-diphenylmethane diisocyanate: 20 parts; 1,5-naphthalene diisocyanate: 15.5 parts; Poly-ε-caprolactone diol: 55 parts; 1,4-Butanediol: 9 parts; Trimethylolpropane: 0.5 parts; Silicon carbide: 0.4 parts; Cyastat ® -LS: 1; HyMax ® 1010: 0.5 parts; Stannous octoate: 0.8 parts; The poly-ε-caprolactone diol has a number average molecular weight of 1500; the average particle size of the silicon carbide powder particles is 30 μm; The method for preparing the high-performance TPU for the intelligent AGV wheel comprises the following steps: (1) Mix poly-ε-caprolactone diol, trimethylolpropane and 1,4-butanediol, and then add Cyastat ® -LS, HyMax ® 1010, stirring thoroughly at 80° C. to obtain a premix; (2) adding two diisocyanates and stannous octoate into storage tank A, adding the premix of step (1) into storage tank B, mixing the materials in storage tank A and storage tank B, stirring at a speed of 400 r / min, vacuum dehydrating at 120° C., and pumping into a twin-screw extruder; (3) Silicon carbide powder is added to the second zone of the screw through an external device and reacted in a twin-screw extruder. The feeding section temperature of the twin-screw extruder is 120°C, the mixing section temperature is 150°C, the extrusion section temperature is 180°C, and the head temperature is 160°C. The high-performance TPU for smart AGV wheels is obtained by granulation.

[0025] Example 2 The high-performance TPU for the intelligent AGV wheel includes the following raw materials in parts by weight: Hexamethylene diisocyanate: 14.15 parts; 1,5-naphthalene diisocyanate: 14.15 parts; Poly-ε-caprolactone diol: 64.3 parts; 1,4-Butanediol: 6.8 parts; Trimethylolpropane: 0.6 parts; Silicon carbide: 0.2 parts; Cyastat ® -LS: 0.5 parts; Stabaxol P 200: 1 part; Stannous octoate: 1 part; The number average molecular weight of the poly-ε-caprolactone diol is 2000; the average particle size of the silicon carbide powder particles is 20 μm; The method for preparing the high-performance TPU for the intelligent AGV wheel comprises the following steps: (1) Mix poly-ε-caprolactone diol, trimethylolpropane and 1,4-butanediol, and then add Cyastat ® -LS, Stabaxol P 200, fully stirred at 100°C to obtain a premix; (2) Add two diisocyanates and stannous octoate into storage tank A, add the premix of step (1) into storage tank B, mix the materials in storage tank A and storage tank B, stir at a speed of 600 r / min, vacuum dehydrate at 120° C., and inject into a twin-screw extruder; (3) Silicon carbide powder is added to the second zone of the screw through an external device and reacted in a twin-screw extruder. The feeding section temperature of the twin-screw extruder is 110°C, the mixing section temperature is 130°C, the extrusion section temperature is 170°C, and the head temperature is 150°C. The granulation is performed to obtain high-performance TPU for smart AGV wheels.

[0026] Example 3 The high-performance TPU for the intelligent AGV wheel includes the following raw materials in parts by weight: Isophorone diisocyanate: 32 parts; 1,5-naphthalene diisocyanate: 8 parts; Poly-ε-caprolactone diol: 50 parts; 1,4-Butanediol: 9 parts; Trimethylolpropane: 1 part; Silicon carbide: 0.5 parts; Cyastat ® -LS: 2 parts; Stabaxol P 200: 0.3 parts; Dibutyltin dilaurate: 0.5 parts; The number average molecular weight of the poly-ε-caprolactone diol is 1000; the average particle size of the silicon carbide powder particles is 50 μm; The method for preparing the high-performance TPU for the intelligent AGV wheel comprises the following steps: (1) Mix poly-ε-caprolactone diol, trimethylolpropane and 1,4-butanediol, and then add Cyastat ® -LS, Stabaxol P 200, fully stirred at 110°C to obtain a premix; (2) Add two isocyanates and dibutyltin dilaurate into storage tank A, add the premix of step (1) into storage tank B, mix the materials in storage tank A and storage tank B, stir at a speed of 800 r / min, vacuum dehydrate at 120° C., and inject into a twin-screw extruder; (3) Silicon carbide powder is added to the second zone of the screw through an external device and reacted in a twin-screw extruder. The feeding section temperature of the twin-screw extruder is 120°C, the mixing section temperature is 150°C, the extrusion section temperature is 180°C, and the head temperature is 160°C. The high-performance TPU for smart AGV wheels is obtained by granulation.

[0027] Comparative Example 1 This comparative example is the same as Example 1, except that it includes the following raw materials in parts by weight: 4,4'-diphenylmethane diisocyanate: 35.5 parts; Poly-ε-caprolactone diol: 55 parts; 1,4-Butanediol: 9 parts; Trimethylolpropane: 0.5 parts; Silicon carbide: 0.4 parts; Cyastat ® -LS: 1; HyMax ®1010: 0.5 parts; Stannous octoate: 0.8 parts; The number average molecular weight of the poly-ε-caprolactone diol is 1500, the average particle size of the silicon carbide powder particles is 30 μm, and the remaining steps are the same as those in Example 1.

[0028] Comparative Example 2 This comparative example is the same as Example 1, except that the poly-ε-caprolactone diol is replaced by an equal weight portion of polybutylene adipate, the number average molecular weight of the polybutylene adipate is 1500, and the remaining raw materials and specific steps are the same as Example 1.

[0029] Comparative Example 3 This comparative example is the same as Example 1, except that silicon carbide is removed from the raw materials, and the remaining raw materials, weight proportions of the raw materials, and specific steps are the same as those in Example 1.

[0030] Comparative Example 4 This comparative example is the same as Example 1, except that the antistatic agent Cyastat in the raw material ® -LS was removed, and the remaining raw materials, weight proportions of raw materials, and specific steps were the same as those in Example 1.

[0031] Comparative Example 5 This comparative example is the same as Example 1, except that it includes the following raw materials in parts by weight: 4,4'-diphenylmethane diisocyanate: 20 parts; 1,5-naphthalene diisocyanate: 15.5 parts; Poly-ε-caprolactone diol: 55 parts; 1,4-Butanediol: 9.5 parts; Silicon carbide: 0.4 parts; Cyastat ® -LS: 1; HyMax ® 1010: 0.5 parts; Stannous octoate: 0.8 parts; The number average molecular weight of the poly-ε-caprolactone diol is 1500, the average particle size of the silicon carbide powder particles is 30 μm, and the remaining steps are the same as those in Example 1.

[0032] The high-performance TPU for the intelligent AGV wheels obtained in the above embodiments and comparative examples was converted into test samples by injection molding, and the Shore hardness, tensile strength, tear strength, abrasion, endogenous heat, surface resistance, and permanent compression deformation properties thereof were measured. The test results are shown in Tables 1 and 2.

[0033] The tensile strength and tear strength are tested according to ASTM-D412; the hardness and abrasion are tested according to ASTM-D2240 and ISO4649:2024; the endogenous heat is measured by a compression thermometer to record the final fatigue temperature rise of the sample under a test pressure of 55°C, 25min and 1MPa; the antistatic property is tested according to GB / T1410-2006 for surface resistance; the permanent compression deformation is tested according to GB / T7759.1-2015, at a temperature of 70°C and 22h.

[0034] Table 1 Mechanical properties and wear test results

[0035] Table 2 Final fatigue temperature rise, surface resistance, and permanent compression deformation test results

[0036] As shown in Table 1 and Table 2, the mechanical strength and wear data of Example 1 and Comparative Example 1 are compared to show that the present invention adopts 1,5-naphthalene diisocyanate mixed with other diisocyanates to give TPU rigidity and better mechanical strength, and increase its dynamic bearing capacity; compared with Example 1, Comparative Example 5 adopts a single chain extender 1,4-butanediol, and its final fatigue temperature rise and permanent compression deformation are significantly increased, which shows that mixing the multifunctional chain extender trimethylolpropane into the chain extender can increase the crosslinking degree of TPU, thereby improving the heat resistance of TPU and reducing the permanent compression deformation of TPU; the data of Comparative Example 2 and Example 1 show that the mechanical properties and heat resistance of polycaprolactone TPU are better than those of ordinary polyester TPU; the data of Comparative Examples 3 and 4 further illustrate that the addition of high thermal conductivity material silicon carbide is more conducive to the heat dissipation of the material, and the combination of 1,5-naphthalene diisocyanate and trimethylolpropane further improves the heat resistance of the product and prolongs the service life of the material, and the addition of antistatic agent makes the material better suitable for various working scenarios.

Claims

1. A high-performance TPU for intelligent AGV wheels, characterized by: The invention comprises the following raw materials in parts by weight: Diisocyanate: 28.3-40 parts; Poly-ε-caprolactone diol: 50-64.3 parts; Chain extender: 7.4-10 parts; Silicon carbide: 0.2-0.5 parts; Antistatic agent: 0.5-2 parts; Hydrolysis stabilizer: 0.3-1 part; Catalyst: 0.5-1 part; The number average molecular weight of the poly-ε-caprolactone diol is 1500-2000; The diisocyanate is a mixture of one of 4,4'-diphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate and 1,5-naphthalene diisocyanate; The chain extender is a mixture of 1,4-butanediol and trimethylolpropane.

2. The high-performance TPU for intelligent AGV wheels according to claim 1, characterized in that: The mass fraction of 1,5-naphthalene diisocyanate in the diisocyanate mixed diisocyanate is 20%-50%.

3. The high-performance TPU for intelligent AGV wheels according to claim 1, characterized in that: The mass fraction of trimethylolpropane in the chain extender is 5%-10% of the mixed chain extender.

4. The high-performance TPU for intelligent AGV wheels according to claim 1, characterized in that: The average particle size of the silicon carbide is 20-50 μm.

5. The high-performance TPU for intelligent AGV wheels according to claim 1, characterized in that: The antistatic agent is propyltrimethylammonium methyl sulfate (3-laurylamide).

6. The high-performance TPU for intelligent AGV wheels according to claim 1, characterized in that: The hydrolysis stabilizer is one of monomeric carbodiimide and polycarbodiimide.

7. The high-performance TPU for intelligent AGV wheels according to claim 1, characterized in that: The catalyst is one of dibutyltin dilaurate and stannous octoate.

8. A method for preparing the high-performance TPU for smart AGV wheels according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) Mixing poly-ε-caprolactone diol and a chain extender, then adding an antistatic agent and a hydrolysis stabilizer and stirring at 80-110° C. to obtain a premix; (2) adding diisocyanate and catalyst into storage tank A, adding the premix of step (1) into storage tank B, mixing the materials in storage tank A and storage tank B, dehydrating under vacuum under stirring conditions, and pumping into a twin-screw extruder; (3) Add silicon carbide to the second zone of the screw, react in a twin-screw extruder at 110-180°C, and granulate to obtain high-performance TPU for smart AGV wheels.

9. The method for preparing high-performance TPU for intelligent AGV wheels according to claim 8, characterized in that: In the step (2), the stirring rate is 400-800 r / min, and the vacuum dehydration temperature is 90-120°C.

10. The method for preparing high-performance TPU for intelligent AGV wheels according to claim 8, characterized in that: In the step (3), the feeding section temperature of the twin-screw extruder is 110-120°C, the mixing section temperature is 130-150°C, the extrusion section temperature is 170-180°C, and the die head temperature is 150-160°C.

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