High-load polyurethane microporous elastomer and preparation method and application thereof

Abstract

The invention discloses a high-load polyurethane microporous elastomer and its preparation method and application, belonging to the technical field of polyurethane resin. Its technical scheme is: composed of component A and component B, wherein: component A is composed of high-functionality high-activity polyether polyol, polyether polymer polyol, chain extender, foam leveling agent, catalyst, foaming agent, component B is polyester polyol-modified isocyanate, component A and component B are mixed in a ratio of 100: (90-110) to prepare a low-speed and durable solid tire. The high-load polyurethane microporous elastomer provided by the present invention has a higher load characteristic, is suitable for high-load low-speed engineering vehicle solid tires, and has a significant advantage of durability.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane resins, and in particular relates to a high-load polyurethane microporous elastomer and a preparation method and application thereof. Background Art

[0002] Solid tires are industrial tires that are suitable for vehicles running under harsh conditions of low speed and high load. They are significantly better than pneumatic tires in terms of safety, durability, and economy. They are widely used in various industrial vehicles, military vehicles, construction machinery, and trailer vehicles at ports and airports. Traditional solid tires are made of rubber, but they have disadvantages such as high density, low load-bearing capacity, and environmental pollution. Polyurethane solid tires have been gradually promoted due to their low product density, strong wear resistance, good grip, simple environmental protection process, and can be made into a variety of colors. However, due to the poor thermal conductivity and fast heat generation of polyurethane materials, polyurethane tires generate endogenous heat during long-term cyclic movement. At the same time, the friction between the tire and the ground causes heat, and a large amount of heat energy is dissipated inside the tire, causing melting inside the tire, and the tire is deformed and cannot be used.

[0003] Chinese invention patent CN111533868A discloses a polyurethane for low-speed solid tires, which is obtained by reacting component A reactive to isocyanate and component B containing isocyanate prepolymer, component A contains: polyether ester polyol, diol, polyol amine; component B contains: polyisocyanate, polyether ester polyol, aromatic diol and / or aromatic diamine. The polyurethane product produced has excellent mechanical properties. However, the tire produced by this patent has a high molding density and low hardness. The mechanical properties, hydrolysis resistance and compression deformation were tested, but the load-bearing and running resistance performance were not tested.

[0004] Chinese invention patent CN116102709A discloses a polyurethane composite material for tire solid core filling. The polyurethane elastomer prepared from the polyurethane composite material has high pressure and load resistance, good low temperature flexibility and aging resistance, and is suitable for use as tire solid core filling. The patent uses relatively expensive polytetramethylene ether polyol, and requires tire filling, and the non-integrated molding process is complicated.

[0005] Chinese invention patent CN114127147A discloses a polyurethane composition, a product prepared using the polyurethane composition, and a method for preparing the product. The polyurethane foam prepared by using an ether-ester copolymer polyurethane composition containing a specific structure can achieve suppressed internal heat accumulation, high thermal stability, and excellent tear strength. The tire prepared in this patent is a 24-inch diameter bicycle, which has a small tire diameter and fast heat dissipation, and has a small load and a short running time.

[0006] Therefore, there is an urgent need for a new polyurethane microporous elastomer for high-load industrial solid tires and a preparation method thereof. Summary of the invention

[0007] The invention provides a high-load polyurethane microporous elastomer and a preparation method and application thereof, which is suitable for high-load low-speed engineering vehicle solid tires and has a significant running durability advantage.

[0008] The technical solution of the present invention is:

[0009] In a first aspect, a high-load polyurethane microporous elastomer is disclosed, which is composed of a component A and a component B, wherein the mass ratio of component A to component B is 100:(90-110); wherein:

[0010] Component A is composed of the following raw materials, wherein the total mass of the polyether polyol and the polyether polymer polyol is 100%, and the remaining raw materials are calculated as a percentage of the total mass of the polyether polyol and the polyether polymer polyol;

[0011] Polyether polyol 60-90%

[0012] Polyether polymer polyol 10-40%

[0013] Chain extender 15-25%

[0014] Foam leveler 0.3-0.6%

[0015] Catalyst 0.6-1.5%

[0016] Foaming agent 3-6%;

[0017] Component B is composed of the following raw materials: the total mass of polyester polyol and isocyanate is calculated as 100%, and the inhibitor is calculated as the total mass of polyester polyol and isocyanate;

[0018] Polyester polyol 25-40%

[0019] Isocyanate 60-75%

[0020] Inhibitor 40ppm;

[0021] The polyether polyol is a polyether polyol with a functionality of 4.5-6, a number average molecular weight of 9000-12000 g / mol, and a primary hydroxyl content molar fraction of >70%, preferably 10LD8005 or CHE-628;

[0022] The solid content of the polyether polymer polyol is 23-45%, and the average hydroxyl value is 21-26 mgKOH / g; preferably one of POP36 / 28, CHP-H30, and CHP-H45;

[0023] The polyester polyol is a branched polyester prepared by polycondensation reaction of a small molecule polyol mixed with a difunctionality and a trifunctionality and a small molecule dibasic acid, and has a number average molecular weight of 2000-3500 g / mol. The preparation method of the polyester polyol is as follows: adding measured small molecule polyols, dibasic acids and a tetraisopropyl titanate catalyst in an amount of 60 ppm of the total weight of the small molecule polyols and the dibasic acids into a reaction kettle in sequence, starting stirring, starting to heat up under nitrogen protection, carrying out esterification reaction at 140-180°C, stabilizing the dehydration speed, passing through a rectification tower, maintaining the tower top temperature at 90-105°C, continuously heating up to a holding temperature of 220-240°C, carrying out ester exchange reaction, and introducing nitrogen to take away excess small molecule polyols, starting timing from the time the temperature rises to the holding temperature, taking samples for analysis every 2 hours until the final acid value and hydroxyl value are reached, cooling to room temperature, discharging and storing to obtain the polyester polyol.

[0024] Preferably, the difunctional small molecule polyol is one or two of ethylene glycol, diethylene glycol, 1,4-butanediol, and 1,6-hexanediol; the trifunctional small molecule polyol is one of propylene glycol and trimethylolpropane; the difunctional small molecule polyol and the trifunctional small molecule polyol are mixed in a molar ratio of (11-49):1; the small molecule dibasic acid is one of azelaic acid, sebacic acid, and dodecanedioic acid and one of phthalic anhydride and terephthalic acid, mixed in a molar ratio of (1-5):1.

[0025] Preferably, the chain extender is two or three of ethylene glycol, diethylene glycol, 1,4-butanediol and 1,3-propylene glycol.

[0026] Preferably, the foam leveling agent is a foam leveling agent with a brand number of DC193 or DC2525 produced by Air Products and Chemicals, Inc. of the United States.

[0027] Preferably, the catalyst is a compound of one of the tertiary amine catalysts with the brand name DXD-01C or DXD-07C produced by Shandong Yinuowei Polyurethane Co., Ltd. and dibutyltin dilaurate.

[0028] Preferably, the foaming agent is a mixture of water and 1,1,1,3,3-pentafluoropropane in a mass ratio of 1:(5-10).

[0029] Preferably, the isocyanate is a mixture of 4,4-diphenylmethane diisocyanate and carbodiimide-modified isocyanate.

[0030] Preferably, the polymerization inhibitor is phosphoric acid.

[0031] In a second aspect, a method for preparing the high-load polyurethane microporous elastomer is disclosed, comprising the following steps:

[0032] 1) Preparation of component A: put polyether polyol, polyether polymer polyol, chain extender, foam leveler, catalyst and blowing agent into a reaction kettle in proportion, stir for 1-2 hours at normal pressure 10-20°C to obtain component A; Preparation of component B: put polyester polyol into a reaction kettle, control the material temperature at 40-50°C, add inhibitor and isocyanate, react at 75-85°C for 1.5-2.5 hours to obtain component B;

[0033] 2) Inject component A and component B into the material tank of a low-pressure casting machine respectively. The temperature of component A is 25-35°C and the temperature of component B is 35-45°C. After mixing component A and component B in proportion, inject them into a mold at 50-60°C and open the mold for 3-5 minutes to obtain a high-load polyurethane microporous elastomer, which is a high-load and durable solid tire.

[0034] In a third aspect, the application of the high-load polyurethane microporous elastomer in low-speed engineering vehicle solid tires is disclosed.

[0035] Compared with the prior art, the present invention has the following beneficial effects:

[0036] 1. The high-load polyurethane microporous elastomer prepared by the present invention is suitable for high-load low-speed engineering vehicle solid tires, and has a significant running-resistance advantage. Component A is a polyether system, and component B is a polyester system. The two components are combined and complement each other. The tire takes into account the advantages of both polyester polyols and polyether polyols, and has a higher thermal conductivity and a lower thermal expansion coefficient. At the same time, the polyether polymer polyol in the formula contains a large number of benzene rings, which can help improve the heat resistance, support and open-pore properties of the tire.

[0037] 2. The component A of the present invention uses a high-functionality, high-molecular-weight, high-activity polyether polyol, whose high activity ensures that the tire can be normally matured and molded in 3-5 minutes. The high functionality produces a dense cross-linked network structure, which gives the product a high load capacity and heat resistance.

[0038] 3. A special polyester polyol is used in component B of the present invention. The polyester polyol contains a benzene ring and a branched structure, and has better thermal stability and load-bearing capacity. At the same time, the polyester polyol uses a small molecular dibasic acid with 9-12 carbon atoms. The molecular structure of the polyester polyol is more regularly arranged and has better thermal conductivity, so that heat can be conducted to the tire surface faster, avoiding the inability to dissipate heat and causing the inside of the tire to melt.

[0039] 4. The foaming agent used in the present invention is a mixture of water and 1,1,1,3,3-pentafluoropropane, which improves the gas phase thermal conductivity, facilitates the heat dissipation, makes the tire surface smooth and free of pits, is non-flammable and non-explosive, safe, and more environmentally friendly. DETAILED DESCRIPTION

[0040] In order to enable those skilled in the art to better understand the technical solutions in the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all of the embodiments.

[0041] Unless otherwise specified, the raw materials used in the examples and comparative examples are commercially available. The raw material description is as follows:

[0042] 10LD8005: polyether polyol, functionality 4.5, number average molecular weight 9000g / mol, Shandong Bluestar Dongda Chemical Co., Ltd., primary hydroxyl content molar fraction> 70%;

[0043] CHE-628: polyether polyol, functionality 6, number average molecular weight 12000 g / mol, Changhua Chemical Technology Co., Ltd., primary hydroxyl content molar fraction> 70%;

[0044] ED-28: polyether polyol, functionality 2, number average molecular weight 4000 g / mol, Shandong Bluestar Dongda Chemical Co., Ltd.;

[0045] 10LD83EK: polyether polyol, functionality 3, number average molecular weight 6000 g / mol, Shandong Bluestar Dongda Chemical Co., Ltd.;

[0046] INOVOL F330N: polyether polyol, functionality 3, number average molecular weight 5000 g / mol, Shandong INOVOL New Materials Co., Ltd.

[0047] POP36 / 28: polyether polymer polyol, solid content 23%, average hydroxyl value 26mgKOH / g, Shandong Bluestar Dongda Chemical Co., Ltd.;

[0048] CHP-H30: polyether polymer polyol, solid content 30%, average hydroxyl value 25mgKOH / g, Changhua Chemical Technology Co., Ltd.

[0049] CHP-H45: polyether polymer polyol, solid content 45%, average hydroxyl value 21mgKOH / g, Changhua Chemical Technology Co., Ltd.

[0050] PE-3322: polyester polyol, functionality 2, number average molecular weight 2000 g / mol, obtained by polymerization of adipic acid, terephthalic acid, ethylene glycol, butanediol, Shandong Yinuowei Polyurethane Co., Ltd.;

[0051] PE-2325: polyester polyol, functionality 2-3, number average molecular weight 2000g / mol, obtained by polymerization of adipic acid, ethylene glycol, diethylene glycol, and trimethylolpropane, Shandong Yinuowei Polyurethane Co., Ltd.;

[0052] DC2525: Foam leveler, Air Products & Chemicals, Inc., USA;

[0053] DC193: Foam leveler, Air Products & Chemicals, Inc., USA;

[0054] DXD-01C: tertiary amine catalyst, Shandong Yinuowei Polyurethane Co., Ltd.;

[0055] DXD-07C: tertiary amine catalyst, Shandong Yinuowei Polyurethane Co., Ltd.;

[0056] HFC-245fa: blowing agent, 1,1,1,3,3-pentafluoropropane, Sinochem Blue Sky Group Co., Ltd.;

[0057] MDI-100: 4,4-diphenylmethane diisocyanate, Wanhua Chemical Group Co., Ltd.

[0058] CDMDI-100L: carbodiimide-modified isocyanate, Wanhua Chemical Group Co., Ltd.

[0059] Polyester polyols used in the preparation examples and comparative examples:

[0060] Polyester polyol a: 11.8 kg ethylene glycol, 19.8 kg 1,6-hexanediol, 3.1 kg trimethylolpropane, 54.2 kg sebacic acid, 11.1 kg terephthalic acid and 6 g tetraisopropyl titanate catalyst were added to the reactor in sequence, stirring was started, and the temperature was raised under nitrogen protection. The esterification reaction was carried out at 140°C-180°C, and the dehydration rate was stabilized. The temperature was passed through a distillation tower, and the top temperature was maintained at 90°C-105°C. The temperature was continuously raised to 235°C for ester exchange reaction, and nitrogen was introduced to take away excess small molecule polyols. The timing was started from the temperature rising to 235°C. Samples were taken every 2 hours for analysis until the final acid value and hydroxyl value were reached, and the temperature was cooled to room temperature. The material was discharged and stored to obtain polyester polyol a with a number average molecular weight of 2500 g / mol.

[0061] Polyester polyol b: 35 kg of diethylene glycol, 1.3 kg of propylene glycol, 52.4 kg of dodecanedioic acid, 11.3 kg of phthalic anhydride and 6 g of tetraisopropyl titanate catalyst were added to the reactor in sequence, stirring was turned on, and the temperature was raised under nitrogen protection. The esterification reaction was carried out at 140°C-180°C, and the dehydration rate was stabilized. The temperature was passed through a distillation tower, and the top temperature was maintained at 90°C-105°C. The temperature was continuously raised to 225°C for ester exchange reaction, and nitrogen was introduced to take away excess small molecule polyols. The timing was started from the time the temperature rose to 225°C. Samples were taken every 2 hours for analysis until the final acid value and hydroxyl value were reached, and the samples were cooled to room temperature. The material was discharged and stored to obtain polyester polyol b with a number average molecular weight of 3000 g / mol.

[0062] Polyester polyol c: 10.7 kg ethylene glycol, 15.5 kg 1,4-butanediol, 4.2 kg trimethylolpropane, 40.4 kg dodecanedioic acid, 29.2 kg terephthalic acid and 6 g tetrapropyl titanate catalyst were added to the reactor in sequence, stirring was started, and the temperature was raised under nitrogen protection. The esterification reaction was carried out at 140°C-180°C, and the dehydration rate was stabilized. The temperature was passed through a distillation tower, and the top temperature was maintained at 90°C-105°C. The temperature was continuously raised to 240°C for ester exchange reaction, and nitrogen was introduced to take away excess small molecule polyols. The timing was started from the time the temperature rose to 240°C. Samples were taken every 2 hours for analysis until the final acid value and hydroxyl value were reached. The samples were cooled to room temperature, and the material was discharged and stored to obtain polyester polyol c with a number average molecular weight of 3500 g / mol.

[0063] Polyester polyol d: 19.3 kg of diethylene glycol, 16.4 kg of 1,4-butanediol, 0.7 kg of propylene glycol, 45 kg of sebacic acid, 18.6 kg of terephthalic acid and 6 g of tetraisopropyl titanate catalyst were added to the reactor in sequence, stirring was started, and the temperature was raised under nitrogen protection. The esterification reaction was carried out at 140°C-180°C, and the dehydration rate was stabilized. The temperature was passed through a distillation tower, and the top temperature was maintained at 90°C-105°C. The temperature was continuously raised to 240°C for ester exchange reaction, and nitrogen was introduced to take away excess small molecule polyols. The timing was started from the time the temperature rose to 240°C. Samples were taken every 2 hours for analysis until the final acid value and hydroxyl value were reached. The sample was cooled to room temperature, and the material was discharged and stored to obtain polyester polyol d with a number average molecular weight of 3500 g / mol.

[0064] Polyester polyol e: 11.7 kg ethylene glycol, 19.9 kg diethylene glycol, 4.4 kg trimethylolpropane, 55.3 kg azelaic acid, 8.7 kg phthalic anhydride and 6 g tetraisopropyl titanate catalyst were added to the reactor in sequence, stirring was turned on, and the temperature was raised under nitrogen protection. The esterification reaction was carried out at 140°C-180°C, and the dehydration rate was stabilized. The temperature was passed through a distillation tower, and the top temperature was maintained at 90°C-105°C. The temperature was continuously raised to 220°C for ester exchange reaction, and nitrogen was introduced to remove excess small molecule polyols. The timing was started from the time the temperature reached 220°C. Samples were taken every 2 hours for analysis until the final acid value and hydroxyl value were reached, and the samples were cooled to room temperature. The material was discharged and stored to obtain polyester polyol e with a number average molecular weight of 2000 g / mol.

[0065] Example 1

[0066] The preparation method of a high-load polyurethane microporous elastomer comprises the following steps:

[0067] Preparation of component A: 90 kg of polyether polyol 10LD8005, 10 kg of polyether polymer polyol CHP-H45, 8 kg of chain extender ethylene glycol, 4 kg of chain extender diethylene glycol, 13 kg of chain extender 1,4-butanediol, 0.3 kg of foaming agent DC193, 0.06 kg of catalyst T-12, 0.54 kg of catalyst DXD-01C, 0.5 kg of foaming agent water and 2.5 kg of foaming agent HFC-245fa were put into a reaction kettle, and stirred for 2 hours at normal pressure and 10°C to obtain component A;

[0068] Preparation of component B: 30 kg of polyester polyol a was put into a reactor, the material temperature was controlled at 45°C, 4 g of inhibitor phosphoric acid, 60 kg of MDI-100 and 10 kg of CDMDI-100L were added, and the reaction was carried out at 75°C for 1.5 hours to obtain component B;

[0069] The high-load polyurethane microporous elastomer is used as follows: component A and component B are respectively injected into a material tank of a low-pressure casting machine, the temperature of component A is 25°C, and the temperature of component B is 45°C. Component A and component B are mixed at a mass ratio of 100:110, and then injected into a 50°C mold. The mold is opened for 5 minutes to obtain a high-load and durable solid tire.

[0070] Example 2

[0071] The preparation method of the high-load polyurethane microporous elastomer of this embodiment is as follows:

[0072] Preparation of component A: 80 kg of polyether polyol 10LD8005, 20 kg of polyether polymer polyol POP36 / 28, 7 kg of chain extender diethylene glycol, 13 kg of chain extender 1,4-butanediol, 0.4 kg of foaming agent DC193, 0.05 kg of catalyst T-12, 0.8 kg of catalyst DXD-01C, 0.6 kg of foaming agent water and 3.6 kg of foaming agent HFC-245fa were put into a reaction kettle, and stirred for 1.5 hours at normal pressure and 15°C to obtain component A;

[0073] Preparation of component B: 35 kg of polyester polyol b was put into a reactor, the material temperature was controlled at 45°C, 4 g of inhibitor phosphoric acid, 53 kg of MDI-100 and 12 kg of CDMDI-100L were added, and the reaction was carried out at 80°C for 2 hours to obtain component B;

[0074] The high-load polyurethane microporous elastomer is used as follows: component A and component B are respectively injected into a material tank of a low-pressure casting machine, the temperature of component A is 30°C, and the temperature of component B is 40°C. Component A and component B are mixed in a mass ratio of 100:90, and then injected into a 55°C mold. The mold is opened for 4 minutes to obtain a high-load and durable solid tire.

[0075] Example 3

[0076] The preparation method of the high-load polyurethane microporous elastomer of this embodiment is as follows:

[0077] Preparation of component A: 70 kg of polyether polyol CHE-628, 30 kg of polyether polymer polyol POP36 / 28, 12 kg of chain extender ethylene glycol, 3 kg of chain extender 1,4-butanediol, 0.6 kg of foaming agent DC2525, 0.04 kg of catalyst T-12, 1 kg of catalyst DXD-01C, 0.5 kg of foaming agent water and 4.5 kg of foaming agent HFC-245fa were put into a reaction kettle, and stirred at normal pressure and 20°C for 1 hour to obtain component A;

[0078] Preparation of component B: 40 kg of polyester polyol c was put into a reactor, the material temperature was controlled at 50°C, 4 g of inhibitor phosphoric acid, 56 kg of MDI-100 and 4 kg of CDMDI-100L were added, and the reaction was carried out at 85°C for 2.5 hours to obtain component B;

[0079] The high-load polyurethane microporous elastomer is used as follows: component A and component B are respectively injected into a material tank of a low-pressure casting machine, the temperature of component A is 35°C, and the temperature of component B is 45°C. Component A and component B are mixed in a ratio of 100:105, and then injected into a 55°C mold. The mold is opened for 4 minutes to obtain a high-load and durable solid tire.

[0080] Example 4

[0081] The preparation method of the high-load polyurethane microporous elastomer of this embodiment is as follows:

[0082] Preparation of component A: 60 kg of polyether polyol CHE-628, 40 kg of polyether polymer polyol CHP-H30, 7 kg of chain extender ethylene glycol, 6 kg of chain extender propylene glycol, 5 kg of chain extender 1,4-butanediol, 0.5 kg of foaming agent DC2525, 0.03 kg of catalyst T-12, 1.2 kg of catalyst DXD-01C, 0.55 kg of foaming agent water and 5.45 kg of foaming agent HFC-245fa were put into a reaction kettle, and stirred at normal pressure and 10°C for 2 hours to obtain component A;

[0083] Preparation of component B: 35 kg of polyester polyol d was put into a reactor, the material temperature was controlled at 50°C, 4 g of inhibitor phosphoric acid, 59 kg of MDI-100 and 6 kg of CDMDI-100L were added, and the reaction was carried out at 85°C for 2 hours to obtain component B;

[0084] The high-load polyurethane microporous elastomer is used as follows: component A and component B are respectively injected into a material tank of a low-pressure casting machine, the temperature of component A is 30°C, and the temperature of component B is 40°C. Component A and component B are mixed in a mass ratio of 100:101, and then injected into a 60°C mold. The mold is opened for 3 minutes to obtain a high-load and durable solid tire.

[0085] Example 5

[0086] The preparation method of the high-load polyurethane microporous elastomer of this embodiment is as follows:

[0087] Preparation of component A: 80 kg of polyether polyol CHE-628, 20 kg of polyether polymer polyol POP36 / 28, 24 kg of chain extender 1,4-butanediol, 0.3 kg of foaming agent DC2525, 0.2 kg of foaming agent DC193, 0.02 kg of catalyst T-12, 1.48 kg of catalyst DXD-07C, 0.65 kg of foaming agent water and 5.2 kg of foaming agent HFC-245fa were put into a reaction kettle, and stirred at normal pressure and 10°C for 1.5 hours to obtain component A;

[0088] Preparation of component B: 25 kg of polyester polyol e was put into a reactor, the material temperature was controlled at 40°C, 4 g of inhibitor phosphoric acid, 60 kg of MDI-100 and 15 kg of CDMDI-100L were added, and the reaction was carried out at 75°C for 1.5 hours to obtain component B;

[0089] The high-load polyurethane microporous elastomer is used as follows: component A and component B are respectively injected into a material tank of a low-pressure casting machine, the temperature of component A is 30°C, and the temperature of component B is 35°C. Component A and component B are mixed in a mass ratio of 100:93, and then injected into a 60°C mold. The mold is opened for 4 minutes to obtain a high-load and durable solid tire.

[0090] Comparative Example 1

[0091] The difference between Comparative Example 1 and Example 2 is that, instead of using polyether polyol 10LD8005, component A uses polyether polyol 10LD83EK of equal mass.

[0092] Comparative Example 2

[0093] The difference between Comparative Example 2 and Example 2 is that, instead of using the polyether polymer polyol POP36 / 28 in component A, an equal mass of polyether polyol INOVOL F330N is used instead.

[0094] Comparative Example 3

[0095] The difference between Comparative Example 3 and Example 2 is that, instead of using polyester polyol b as component B, an equal mass of polyether polyol ED-28 is used instead.

[0096] Comparative Example 4

[0097] The difference between Comparative Example 4 and Example 2 is that, instead of using polyester polyol b as component B, polyester polyol PE-3322 of equal mass is used instead.

[0098] Comparative Example 5

[0099] The difference between Comparative Example 5 and Example 2 is that, instead of using polyester polyol b as component B, polyester polyol PE-2325 of equal mass is used instead.

[0100] The high-load and durable solid tires prepared in Examples 1-5 and Comparative Examples 1-5 were tested for performance. The size of the solid tires was 4 inches wide and 5 inches in diameter. The test results are shown in Table 1-2, where the product density was tested with reference to GB / T 6343-2009 "Determination of apparent density of foam plastics and rubber", the hardness was tested with reference to GB / T 3903.4-2017 "Footwear test method hardness", the tensile strength and elongation were tested with reference to GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber", and the right-angle tear strength was tested with reference to GB / T 529-2009 "Determination of tear strength of vulcanized rubber or thermoplastic rubber". The tire was loaded with 200 kg and the speed was 10 km / h. The load-bearing and durable running test was carried out at room temperature.

[0101] Table 1 Performance test results of polyurethane foam tires of Examples 1-5

[0102]

[0103] Table 2 Performance test results of polyurethane foam tires of comparative examples 1-5

[0104]

[0105] It can be seen from Table 1-2 that the tires prepared in Examples 1-5 of the present invention have excellent mechanical properties and a density of 340-355 kg / m 3 In the running test with a load of 200kg and a speed of 10km / h, it can last for 120 minutes without deformation or melting.

[0106] Compared with Example 2, the mechanical properties of Comparative Example 1 decreased to varying degrees, and the tire was deformed and melted after 85 minutes of running test, because the functionality of component A was low and the heat resistance was poor; the tensile strength and right-angle tear strength of Comparative Example 2 were reduced, and the tire was deformed after 105 minutes of running test, but the core was not melted, because components A and B used high-functionality and high-activity polyether polyols and special-structured polyester polyols, respectively, but did not use auxiliary polyether polymers POP, and had weak load capacity, resulting in tire deformation but no melting; the mechanical properties of Comparative Example 3 decreased significantly, and the tire was seriously deformed after 70 minutes of running test The mechanical properties of Comparative Example 4 decreased, and the tire was deformed and melted after a 90-minute running test. The reason is that the polyester structure used in its B component is different from that of the present invention. Although the polyester polyol used contains benzene rings and has a suitable molecular weight, its functionality is low and the specified small molecule dibasic acid is not used. The mechanical properties of Comparative Example 5 decreased, and the tire was deformed and melted after a 95-minute running test. The reason is that the functionality and molecular weight of the polyester polyol in component B of Comparative Example 5 are within the required range, but it does not contain benzene rings and the specified small molecule dibasic acid is not used.

Claims

1. High-load polyurethane microcellular elastomer, characterized in that: It is composed of component A and component B, and the mass ratio of component A to component B is 100: (90-110); wherein: Component A is composed of the following raw materials, wherein the total mass of the polyether polyol and the polyether polymer polyol is 100%, and the remaining raw materials are calculated as a percentage of the total mass of the polyether polyol and the polyether polymer polyol; Polyether polyol 60-90% Polyether polymer polyol 10-40% Chain extender 15-25% Foam leveler 0.3-0.6% Catalyst 0.6-1.5% Foaming agent 3-6%; Component B is composed of the following raw materials: the total mass of polyester polyol and isocyanate is calculated as 100%, and the inhibitor is calculated as the total mass of polyester polyol and isocyanate; Polyester polyol 25-40% Isocyanate 60-75% Inhibitor 40ppm; The polyether polyol is a polyether polyol with a functionality of 4.5-6, a number average molecular weight of 9000-12000 g / mol, and a primary hydroxyl content molar fraction of >70%; The solid content of the polyether polymer polyol is 23-45%, the average hydroxyl value is 21-26 mgKOH / g, and the polyether polymer polyol is one of POP36 / 28, CHP-H30, and CHP-H45; The polyester polyol is a branched polyester prepared by a condensation reaction of a small molecule polyol mixed with difunctionality and trifunctionality and a small molecule dibasic acid, and has a number average molecular weight of 2000-3500 g / mol; the difunctional small molecule polyol and the trifunctional small molecule polyol are mixed in a molar ratio of (11-49):1; the small molecule dibasic acid is a mixture of one of azelaic acid, sebacic acid, and dodecanedioic acid and one of phthalic anhydride and terephthalic acid in a molar ratio of (1-5):

1.

2. The high-load polyurethane microcellular elastomer according to claim 1, characterized in that: The difunctional small molecule polyol is one or two of ethylene glycol, diethylene glycol, 1,4-butanediol, and 1,6-hexanediol; the trifunctional small molecule polyol is one of propylene glycol and trimethylolpropane.

3. The high-load polyurethane microcellular elastomer according to claim 1, characterized in that: The chain extender is two or three of ethylene glycol, diethylene glycol, 1,4-butanediol and 1,3-propylene glycol.

4. The high-load polyurethane microcellular elastomer according to claim 1, characterized in that: The foam leveling agent is DC193 or DC2525.

5. The high-load polyurethane microcellular elastomer according to claim 1, characterized in that: The catalyst is a compound of one of DXD-01C or DXD-07C and dibutyltin dilaurate.

6. The high-load polyurethane microcellular elastomer according to claim 1, characterized in that: The foaming agent is a mixture of water and 1,1,1,3,3-pentafluoropropane in a mass ratio of 1:(5-10).

7. The high-load polyurethane microcellular elastomer according to claim 1, characterized in that: The isocyanate is a compound of 4,4-diphenylmethane diisocyanate and carbodiimide-modified isocyanate.

8. The high-load polyurethane microcellular elastomer according to claim 1, characterized in that: The polymerization inhibitor is phosphoric acid.

9. The method for preparing a high-load polyurethane microporous elastomer according to any one of claims 1 to 8, characterized in that: The following steps are involved: 1) Preparation of component A: put polyether polyol, polyether polymer polyol, chain extender, foam leveler, catalyst and blowing agent into a reaction kettle in proportion, stir for 1-2 hours at normal pressure 10-20°C to obtain component A; Preparation of component B: put polyester polyol into a reaction kettle, control the material temperature at 40-50°C, add inhibitor and isocyanate, react at 75-85°C for 1.5-2.5 hours to obtain component B; 2) Inject component A and component B into the material tank of a low-pressure casting machine respectively. The temperature of component A is 25-35°C and the temperature of component B is 35-45°C. After mixing component A and component B in proportion, inject them into a mold at 50-60°C and open the mold for 3-5 minutes to obtain a high-load polyurethane microporous elastomer.

10. Use of the high-load polyurethane microcellular elastomer according to any one of claims 1 to 8 in a solid tire for a low-speed engineering vehicle.

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