Inorganic particle modified waterborne polyurethane resin and preparation method thereof

Abstract

The invention relates to the field of high-molecular polymers, and discloses inorganic particle modified waterborne polyurethane resin and a preparation method thereof. Polyurethane molecules are terminated by hydroxyethyl methylacrylate containing unsaturated double bonds, so that side reaction can be avoided; after polyurethane is emulsified, a large amount of inorganic particles with different particle sizes are uniformly filled into waterborne polyurethane molecules through free radical copolymerization according to multimode grading, so that the water resistance, wear resistance and heat resistance of the waterborne polyurethane resin can be remarkably improved.

Description

Technical Field

[0001] The present invention relates to the field of polymer polymers, and in particular to an inorganic particle modified waterborne polyurethane resin and a preparation method thereof. Background Art

[0002] Polyurethane is a macromolecular compound containing urethane groups in the molecular chain. Generally, people synthesize polyurethane macromolecules through the addition polymerization of isocyanate groups and groups with active hydrogen. Polyurethane materials are widely used in airports, hotels, building materials, apartments, etc., and are widely used in various fields of the national economy. Solvent-based polyurethane has high strength, toughness and good weather resistance, but because it uses organic solvents, a large amount of volatile organic compounds will be emitted during use, inevitably causing environmental pollution. Waterborne polyurethane uses water as a solvent, which not only reduces costs, but also significantly reduces environmental pollution compared to solvent-based polyurethane, so it has received great attention from domestic and foreign experts and scholars. However, because waterborne polyurethane uses water as a solvent, the existing waterborne polyurethane lacks good wear resistance, heat resistance and water resistance during use, and new solutions are needed to overcome this.

[0003] There are many reports on waterborne polyurethane resins and their preparation methods. For example, Patent CN 103450442 A discloses that waterborne polyurethane resins can be synthesized through polyether polyols, polyester polyols and diphenylmethane diisocyanate. This resin has good low-temperature resistance, high solid content and low viscosity. However, the disadvantages of this solution are: (1) The prepolymer prepared has isocyanate groups in diphenylmethane diisocyanate as end groups, and side reactions will occur after water emulsification, which is not conducive to preservation; (2) The synthesized waterborne polyurethane resin has poor heat resistance and water resistance, and the hardness is not high. The above deficiencies have greatly limited its usability. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides an inorganic particle modified waterborne polyurethane resin and a preparation method thereof. The present invention caps the polyurethane molecules with 2-hydroxyethyl methacrylate containing unsaturated double bonds to avoid side reactions, and after emulsifying the polyurethane, inorganic particles with different particle sizes are filled into the waterborne polyurethane molecules through free radical copolymerization and a large amount of uniform filling according to multi-modal grading, so as to improve the water resistance, wear resistance and heat resistance of the waterborne polyurethane resin.

[0005] The specific technical solution of the present invention is as follows: In a first aspect, the present invention provides an inorganic particle-modified waterborne polyurethane resin, which comprises the following raw materials by mass percentage: 2-3 parts by weight of tetraethyl orthosilicate, 2.5-3 parts by weight of ammonia water, 70-75 parts by weight of ethanol, 1.5-2.5 parts by weight of diol, 1-1.5 parts by weight of silane coupling agent, 1-1.5 parts by weight of isocyanate, 0.1-0.5 parts by weight of dimethylolpropionic acid, 0.1-0.5 parts by weight of chain extender, 0.1-0.5 parts by weight of hydroxyethyl methacrylate, 0.1-0.5 parts by weight of triethylamine, 2-5 parts by weight of acrylate monomer, 2-3 parts by weight of methyl ethyl ketone, and 5-20 parts by weight of water, with a total of 100 parts by weight.

[0006] Preferably, the diol is selected from at least one of polypropylene glycol and polycarbonate diol.

[0007] More preferably, the molecular weight of the polypropylene glycol is 1000-3000; the molecular weight of the polycarbonate diol is 1000-3000.

[0008] Preferably, the isocyanate is selected from at least one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

[0009] Preferably, the acrylate monomer is selected from at least one of methyl methacrylate and butyl acrylate.

[0010] Preferably, the silane coupling agent is selected from at least one of silane coupling agent KH-570 and KH-1706.

[0011] Preferably, the chain extender is selected from at least one of diethylene glycol and 1,4-butanediol.

[0012] In a second aspect, the present invention provides a method for preparing an inorganic particle-modified waterborne polyurethane resin, which comprises the following steps: (1) Mix tetraethyl orthosilicate, water, and ethanol evenly, and add ammonia water under temperature control, and react to obtain a silica sol with a particle size of 60-100 nm.

[0013] (2) Mix water and ethanol evenly, add tetraethyl orthosilicate and ammonia water under temperature control, react, add tetraethyl orthosilicate additionally, and keep the temperature for reaction to obtain a silica sol with a particle size of 20-30 nm.

[0014] Step (1) adopts a one-pot cooking method, and at a relatively high reaction temperature and a relatively short reaction time, the obtained silica sol particles have a relatively larger particle size. While step (2) adopts a stepwise addition method, at a relatively low reaction temperature and a relatively long reaction time, the reaction is more controllable, the system is more uniform, and thus the obtained silica sol particles have a smaller particle size.

[0015] (3) Mix the silane coupling agent with the silica sol obtained in steps (1) and (2) respectively, stir and react, centrifuge, and dry the obtained precipitate to obtain modified silica.

[0016] In steps (1) and (2), the present invention uses tetraethyl orthosilicate to hydrolyze in ethanol, and adjusts the dosage and temperature of ammonia water to obtain silica sols with different particle sizes. In step (3), the silica sol is graft-modified with a silane coupling agent.

[0017] (4) Mix diol and isocyanate, stir and react under an inert atmosphere, add dimethylolpropionic acid and methyl ethyl ketone to react, then keep warm and add a chain extender for chain extension reaction. After the chain extension is completed, add 2-hydroxyethyl methacrylate to react, add triethylamine to react, disperse in water at room temperature after the reaction, and remove methyl ethyl ketone by vacuum distillation to obtain an aqueous polyurethane emulsion.

[0018] (5) Add the modified silica with a particle size of 60 - 100 nm to the aqueous polyurethane emulsion obtained in step (4), raise the temperature and then dropwise add acrylate monomers, then add the modified silica with a particle size of 20 - 30 nm, keep warm and continue to dropwise add acrylate monomers, and raise the temperature for reaction after the dropping is completed to obtain an inorganic particle-modified aqueous polyurethane resin.

[0019] First add the modified silica with a large particle size to fill the large pores in the system. Since small pores will be left between the contacts of the large particles, then add the modified silica with a small particle size to fill the small pores, making the compactness of the system better.

[0020] Preferably, in step (1), the temperature control temperature is 30 - 40 °C, and the reaction time is 10 - 12 hours.

[0021] Preferably, in step (2), the temperature control temperature is 20 - 30 °C, the reaction time is 5 - 8 hours; the heat preservation reaction time is 8 - 12 hours.

[0022] Preferably, in step (3), the temperature of the stirring reaction is 50 - 70 °C, the time is 4 - 6 hours; the rotation speed of the centrifugation is 8000 - 12000 rpm, the time is 30 - 40 minutes; the drying temperature is 70 - 90 °C, the time is 10 - 15 hours.

[0023] Preferably, step (4) specifically includes: mixing diol and isocyanate, stirring and reacting for 1 - 1.5 hours under an inert atmosphere at 70 - 90°C, adding dimethylolpropionic acid and methyl ethyl ketone, maintaining the reaction at 70 - 80°C for 2 - 3 hours, adding a chain extender and keeping the reaction for 0.5 - 1.5 hours. After chain extension is completed, adding hydroxyethyl methacrylate and reacting at 60 - 70°C for 2 - 3 hours, adding triethylamine and reacting at 40 - 50°C for 20 - 40 min, and then dispersing in water at room temperature for 20 - 30 minutes; then distilling off methyl ethyl ketone under a vacuum of 0.008 - 0.012 MPa for 1 - 1.5 hours at 40 - 45°C to obtain an aqueous polyurethane emulsion.

[0024] Preferably, step (5) specifically includes: adding modified silica with a particle size of 60 - 100 nm to the aqueous polyurethane emulsion obtained in step (4), heating to 70 - 80°C and then dropping an acrylate monomer. After dropping for 50 - 70 min, adding modified silica with a particle size of 20 - 30 nm, keeping the temperature and continuing to drop the acrylate monomer for 1 - 3 hours. After the dropping is completed, heating to 80 - 85°C and reacting for 1 - 2 hours to obtain an inorganic particle-modified aqueous polyurethane resin.

[0025] Compared with the prior art, the present invention has the following technical effects: (1) By using hydroxyethyl methacrylate containing an unsaturated double bond to cap the polyurethane molecules, the present invention can avoid side reactions.

[0026] (2) After emulsifying the polyurethane, the present invention fills inorganic particles (modified silica) with different particle sizes into the aqueous polyurethane molecules through free radical copolymerization and a large amount of uniform filling according to multimodal grading. Due to the multimodal grading, inorganic particles with different particle sizes are filled into the polyurethane internally in a large amount and uniformly and are filled in multiple levels, which not only retains the advantages of polyurethane but also can significantly improve the water resistance, wear resistance, and heat resistance of the aqueous polyurethane resin.

[0027] (3) The preparation method of the present invention is simple in process and strong in operability. By free radical copolymerization and filling inorganic particles into the aqueous polyurethane, the probability of agglomeration of inorganic particles can be reduced.

[0028] (4) The present invention uses methyl ethyl ketone as a solvent and removes it by decompression after synthesizing the aqueous polyurethane emulsion, which can greatly reduce the residue of organic solvents in the aqueous polyurethane and reduce environmental pollution. Detailed Embodiments

[0029] The present invention will be further described below with reference to embodiments.

[0030] An inorganic particle-modified waterborne polyurethane resin, calculated by mass percentage, contains the following raw materials: 2-3 parts by weight of tetraethyl orthosilicate, 2.5-3 parts by weight of ammonia water, 70-75 parts by weight of ethanol, 1.5-2.5 parts by weight of diol, 1-1.5 parts by weight of silane coupling agent, 1-1.5 parts by weight of isocyanate, 0.1-0.5 parts by weight of dimethylolpropionic acid, 0.1-0.5 parts by weight of chain extender, 0.1-0.5 parts by weight of hydroxyethyl methacrylate, 0.1-0.5 parts by weight of triethylamine, 2-5 parts by weight of acrylate monomer, 2-3 parts by weight of methyl ethyl ketone, 5-20 parts by weight of water, with a total of 100 parts by weight.

[0031] Preferably, the diol is selected from at least one of polypropylene glycol and polycarbonate diol; more preferably, the molecular weight of polypropylene glycol is 1000-3000; the molecular weight of the polycarbonate diol is 1000-3000; the isocyanate is selected from at least one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate; the acrylate monomer is selected from at least one of methyl methacrylate and butyl acrylate; the silane coupling agent is selected from at least one of silane coupling agent KH-570 and KH-1706; the chain extender is selected from at least one of diethylene glycol and 1,4-butanediol.

[0032] A preparation method of an inorganic particle-modified waterborne polyurethane resin, comprising the following steps: (1) Mix tetraethyl orthosilicate, water and ethanol evenly, add ammonia water at a controlled temperature of 30-40 °C, and react for 10-12 hours to obtain silica sol with a particle size of 60-100 nm.

[0033] (2) Mix water and ethanol evenly, add tetraethyl orthosilicate and ammonia water at a controlled temperature of 20-30 °C, react for 5-8 hours, supplement tetraethyl orthosilicate, and keep the temperature for reaction for 8-12 hours to obtain silica sol with a particle size of 20-30 nm.

[0034] (3) Mix the silane coupling agent with the silica sol obtained in steps (1) and (2) respectively, stir and react at 50-70 °C for 4-6 hours, centrifuge at 8000-12000 rpm for 30-40 minutes, and dry the obtained precipitate at 70-90 °C for 10-15 hours to obtain two kinds of modified silica.

[0035] (4) Mix the diol and isocyanate, and stir and react them under an inert atmosphere at 70 - 90 °C for 1 - 1.5 hours. Add dimethylolpropionic acid and butanone, maintain the reaction at 70 - 80 °C for 2 - 3 hours, add the chain extender and keep the reaction for 0.5 - 1.5 hours. After the chain extension is completed, add hydroxyethyl methacrylate and react at 60 - 70 °C for 2 - 3 hours. Add triethylamine and react at 40 - 50 °C for 20 - 40 min, and then disperse it in water at room temperature for 20 - 30 minutes; then distill off butanone under a vacuum of 0.008 - 0.012 MPa for 1 - 1.5 hours at 40 - 45 °C to obtain an aqueous polyurethane emulsion.

[0036] (5) Add modified silica with a particle size of 60 - 100 nm to the aqueous polyurethane emulsion obtained in step (4), heat up to 70 - 80 °C, and then dropwise add acrylate monomer. After dropping for 50 - 70 min, add modified silica with a particle size of 20 - 30 nm, keep the temperature and continue to dropwise add acrylate monomer for 1 - 3 hours. After the dropping is completed, heat up to 80 - 85 °C and react for 1 - 2 hours to obtain an inorganic particle-modified aqueous polyurethane resin. Specific examples Example 1 Formulation of inorganic particle-modified aqueous polyurethane resin: 21 g of tetraethyl orthosilicate, 665 g of ethanol, 24.7 g of ammonia water (28%), 22 g of polypropylene glycol (number average molecular weight 2000), 10.5 g of KH-570, 10.44 g of toluene diisocyanate, 2.6 g of dimethylolpropionic acid, 1.76 g of 1,4-butanediol, 2.6 g of hydroxyethyl methacrylate, 2 g of triethylamine, 118.2 g of water, 42.3 g of methyl methacrylate, 25 g of butanone.

[0038] Preparation process of inorganic particle-modified aqueous polyurethane resin: (1) Add 10.5 g of tetraethyl orthosilicate, 16.6 g of water and 332.5 g of ethanol to a flask, raise the temperature to 40 °C, add 12.35 g of ammonia water, and react for 11 hours to obtain a silica sol with a particle size of 60 - 100 nm.

[0039] (2) Place 16.6 g of water and 332.5 g of ethanol in a flask, keep the temperature at 20 °C, mix evenly, add 5.25 g of tetraethyl orthosilicate and 12.35 g of ammonia water, react for 6 hours, and then add the remaining 5.25 g of tetraethyl orthosilicate, keep the temperature unchanged, and continue to react for 12 hours to obtain a silica sol with a particle size of 20 - 30 nm.

[0040] (3) 10.5 g of KH-570 was respectively stirred with the silica sols obtained in steps (1) and (2) in a flask at 60 °C for 6 hours, and then centrifuged at 10,000 rpm for 35 minutes to obtain a precipitate. The precipitate was placed in a drying oven and dried at 80 °C for 12 hours to obtain two kinds of modified silica.

[0041] (4) 22 g of polypropylene glycol and 10.44 g of toluene diisocyanate were added to a flask equipped with a stirrer, a reflux condenser and a nitrogen inlet device, and the temperature was raised to 85 °C and reacted for 1 hour. Then 2.6 g of dimethylolpropionic acid and 25 g of methyl ethyl ketone were added, and the reaction was maintained at 70 °C for 3 hours. Then, without changing the temperature, 1.76 g of 1,4-butanediol was added and reacted for 1 hour. After the reaction was completed, 2.6 g of 2-hydroxyethyl methacrylate was added, and the temperature was 70 °C and reacted for about 2 hours. Then 2 g of triethylamine was reacted at 45 °C for about 0.5 hour, and then dispersed in the remaining water at room temperature for 30 minutes. Then methyl ethyl ketone was removed by vacuum distillation at a vacuum degree of 0.01 MPa, at a temperature of 42 °C for 1.5 hours. An aqueous polyurethane emulsion was obtained.

[0042] (5) 3.2 g of modified silica with a particle size of 60 - 100 nm was added to the aqueous polyurethane emulsion. After the temperature was raised to 75 °C, 14.1 g of methyl methacrylate was added dropwise. After 1 hour of dropwise addition, 3 g of modified silica with a particle size of 20 - 30 nm was added, and 28.2 g of methyl methacrylate was continuously added dropwise. After 2 hours, the dropwise addition was stopped, and then the temperature was raised to 85 °C and reacted for 1 hour.

[0043] Example 2 Formulation of inorganic particle modified aqueous polyurethane resin: 27.5 g of tetraethyl orthosilicate, 864.5 g of ethanol, 32.11 g of ammonia water, 23.33 g of polycarbonate diol (number average molecular weight 2000), 13.75 g of KH-570, 15 g of diphenylmethane diisocyanate, 2.85 g of dimethylolpropionic acid, 2 g of 1,4-butanediol, 3.85 g of 2-hydroxyethyl methacrylate, 2.15 g of triethylamine, 118.2 g of water, 44 g of methyl methacrylate, 25 g of methyl ethyl ketone.

[0044] Preparation process of inorganic particle modified aqueous polyurethane resin: (1) 13.75 g of tetraethyl orthosilicate, 21.58 g of water and 432.25 g of ethanol were added to a flask. The temperature was raised to 35 °C, and 16.05 g of ammonia water was added and reacted for 12 hours to obtain a silica sol with a particle size of 60 - 100 nm.

[0045] (2) Place 21.58 g of water and 432.25 g of ethanol in a flask, keep the temperature at 20 °C, mix evenly, then add 6.88 g of tetraethyl orthosilicate and 16.05 g of ammonia water, react for 6 hours, and then add the remaining tetraethyl orthosilicate. Without changing the temperature, continue the reaction for 12 hours to obtain a silica sol with a particle size of 20 - 30 nm.

[0046] (3) Stir 13.75 g of KH-570 and the silica sols obtained in steps (1) and (2) in a flask at 60 °C for 6 hours, then centrifuge at 10000 rpm for 30 minutes to obtain a precipitate. Place the precipitate in an oven and dry it at 80 °C for 12 hours to obtain two kinds of modified silica.

[0047] (4) Add 23.33 g of polycarbonate diol and 15 g of diphenylmethane diisocyanate to a flask equipped with a stirrer, a reflux condenser and a nitrogen inlet device. After heating to 70 °C, react for 1.5 hours, then add 2.85 g of dimethylolpropionic acid and 25 g of methyl ethyl ketone, react at 80 °C for 2 hours, then without changing the temperature, add 2 g of 1,4-butanediol and react for 1 hour. After the reaction is completed, add 3.85 g of 2-hydroxyethyl methacrylate and react at 60 °C for about 3 hours, then react with 2.15 g of triethylamine at 45 °C for about 0.5 hours, and then disperse in the remaining water at room temperature for 30 minutes. Then remove methyl ethyl ketone by vacuum distillation under a vacuum of 0.01 MPa and continue at 45 °C for 1.5 hours to obtain an aqueous polyurethane emulsion.

[0048] (5) Add 4.2 g of modified silica with a particle size of 60 - 100 nm to the aqueous polyurethane emulsion. After heating the temperature to 80 °C, add 17.6 g of methyl methacrylate dropwise. After 1 hour of dropping, add 4 g of modified silica with a particle size of 20 - 30 nm, continue to add 26.4 g of methyl methacrylate dropwise, stop dropping after 1.5 hours, and then raise the temperature to 85 °C and continue to react for 1 hour.

[0049] Example 3 Formulation of inorganic particle modified aqueous polyurethane resin: 22.6 g of tetraethyl orthosilicate, 714.8 g of ethanol, 26.55 g of ammonia water, 15 g of polypropylene glycol (number average molecular weight 1500), 11.3 g of KH-1706, 13.32 g of isophorone diisocyanate, 2.46 g of dimethylolpropionic acid, 1.8 g of diethylene glycol, 3.8 g of 2-hydroxyethyl methacrylate, 1.86 g of triethylamine, 96.65 g of water, 38.24 g of butyl acrylate, 25 g of methyl ethyl ketone.

[0050] Preparation process of inorganic particle modified aqueous polyurethane resin: (1) Add 11.3 g of tetraethyl orthosilicate, 17.85 g of water, and 357.4 g of ethanol to a flask. Raise the temperature to 35 °C, add 13.28 g of ammonia water, and react for 12 hours to obtain a silica sol with a particle size of 60 - 100 nm.

[0051] (2) Place 17.85 g of water and 357.4 g of ethanol in a flask, keep the temperature at 20 °C, mix evenly, then add 5.65 g of tetraethyl orthosilicate and 13.27 g of ammonia water, and react for 6 hours. Then add the remaining tetraethyl orthosilicate while keeping the temperature unchanged, and continue to react for 12 hours to obtain a silica sol with a particle size of 20 - 30 nm.

[0052] (3) Add 11.3 g of KH - 1706 and the silica sols obtained in steps (1) and (2) to a flask and stir at 60 °C for 6 hours. Then centrifuge at 10000 rpm for 40 minutes to obtain a precipitate. Place the precipitate in a drying oven and dry at 80 °C for 12 hours to obtain two kinds of modified silica.

[0053] (4) Add 15 g of polypropylene glycol and 13.32 g of isophorone diisocyanate to a flask equipped with a stirrer, a reflux condenser, and a nitrogen inlet device. Raise the temperature to 75 °C and react for 1.5 hours. Then add 2.46 g of dimethylolpropionic acid and 25 g of methyl ethyl ketone, keep the temperature at 75 °C and react for 2.5 hours. Then, without changing the temperature, add 1.8 g of diethylene glycol and react for 1 hour. After the reaction is completed, add 3.8 g of 2 - hydroxyethyl methacrylate and react at 65 °C for about 2.5 hours. React with 1.86 g of triethylamine at 45 °C for about 0.5 hours. Then disperse in the remaining water at room temperature for 30 minutes. Then remove methyl ethyl ketone by vacuum distillation under a vacuum of 0.01 MPa and continue at 45 °C for 1.5 hours to obtain an aqueous polyurethane emulsion.

[0054] (5) Add 4.2 g of modified silica with a particle size of 60 - 100 nm to the aqueous polyurethane emulsion. Raise the temperature to 70 - 80 °C and then dropwise add 10.92 g of butyl acrylate. After 1 hour of dropping, add 4 g of modified silica with a particle size of 20 - 30 nm, continue to dropwise add 27.32 g of butyl acrylate, stop dropping after 2.5 hours, and then raise the temperature to 80 °C and continue to react for 1.5 hours.

[0055] Performance Test Conduct various performance tests on the inorganic - particle - modified aqueous polyurethane resins obtained in the above - mentioned examples. The results are shown in Table 1: Table 1: Performance Indexes of Inorganic - Particle - Modified Aqueous Polyurethane Resins in Each Example Case Stability Coating contact angle Coating hardness Pyrolysis temperature Example 1 Good 123° 3H 265℃ Example 2 Good 128° 2H 262℃ Example 3 Good 125° 3H 270℃ As can be seen from the data in Table 1, the inorganic particle-modified waterborne polyurethane resins prepared through the above embodiments all have good stability and emit blue light, and the stable period reaches more than 6 months. Moreover, the inorganic particle-modified waterborne polyurethane resins have good film-forming properties, the contact angle of the coating film is greater than 120°, showing good water resistance; the hardness of the coating film is greater than 2H, and the abrasion resistance is good; the thermal decomposition temperature is higher than 260 °C, and the heat resistance is good.

[0056] In the present invention, the raw materials and equipment used, unless otherwise specified, are all common raw materials and equipment in the art; the methods used in the present invention, unless otherwise specified, are all conventional methods in the art.

[0057] The above are only the preferred embodiments of the present invention, and do not impose any limitations on the present invention. Any simple modifications, changes, and equivalent transformations made to the above embodiments according to the technical essence of the present invention still belong to the protection scope of the technical solution of the present invention.

Claims

1. An inorganic particle-modified waterborne polyurethane resin, characterized in that: By weight percentage, it contains the following raw materials: 2-3 parts by weight of tetraethyl orthosilicate, 2.5-3 parts by weight of ammonia water, 70-75 parts by weight of ethanol, 1.5-2.5 parts by weight of diol, 1-1.5 parts by weight of silane coupling agent, 1-1.5 parts by weight of isocyanate, 0.1-0.5 parts by weight of dimethylolpropionic acid, 0.1-0.5 parts by weight of chain extender, 0.1-0.5 parts by weight of hydroxyethyl methacrylate, 0.1-0.5 parts by weight of triethylamine, 2-5 parts by weight of acrylate monomer, 2-3 parts by weight of methyl ethyl ketone, 5-20 parts by weight of water, with a total of 100 parts by weight.

2. The inorganic particle-modified waterborne polyurethane resin according to claim 1, wherein: The diol is selected from at least one of polypropylene glycol and polycarbonate diol; The isocyanate is selected from at least one of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

3. The inorganic particle-modified aqueous polyurethane resin according to claim 2, wherein: The molecular weight of the polypropylene glycol is 1000-3000; the molecular weight of the polycarbonate diol is 1000-3000.

4. The inorganic particle-modified aqueous polyurethane resin according to any one of claims 1 to 3, characterized in that: The acrylate monomer is selected from at least one of methyl methacrylate and butyl acrylate.

5. The inorganic particle-modified waterborne polyurethane resin according to claim 1, wherein: The silane coupling agent is selected from at least one of silane coupling agent KH-570 and KH-1706; The chain extender is selected from at least one of diethylene glycol and 1,4-butanediol.

6. A method for preparing an inorganic particle-modified aqueous polyurethane resin according to any one of claims 1-5, characterized in that It includes the following steps: (1) Mix tetraethyl orthosilicate, water and ethanol evenly, add ammonia water under temperature control, react to obtain silica sol with a particle size of 60-100 nm; (2) Mix water and ethanol evenly, add tetraethyl orthosilicate and ammonia water under temperature control, react, supplement tetraethyl orthosilicate, and keep the temperature for reaction to obtain silica sol with a particle size of 20-30 nm; (3) Mix the silane coupling agent with the silica sol obtained in steps (1) and (2) respectively, stir and react, centrifuge, and dry the obtained precipitate to obtain modified silica; (4) Mix the diol and isocyanate, stir and react under an inert atmosphere, add dimethylolpropionic acid and methyl ethyl ketone to react, then keep the temperature and add the chain extender for chain extension reaction. After the chain extension is completed, add hydroxyethyl methacrylate to react, add triethylamine to react, and after the reaction, disperse in water at room temperature and distill off methyl ethyl ketone under reduced pressure to obtain a waterborne polyurethane emulsion; (5) Add the modified silica with a particle size of 60-100 nm to the waterborne polyurethane emulsion obtained in step (4), raise the temperature and dropwise add the acrylate monomer, then add the modified silica with a particle size of 20-30 nm, keep the temperature and continue to dropwise add the acrylate monomer. After the dropping is completed, raise the temperature for reaction to obtain an inorganic particle-modified waterborne polyurethane resin.

7. The preparation method according to claim 6, wherein: In step (1), the temperature control temperature is 30-40 °C, and the reaction time is 10-12 hours; In step (2), the temperature control temperature is 20-30 °C, the reaction time is 5-8 hours; the temperature-keeping reaction time is 8-12 hours.

8. The preparation method according to claim 6, characterized in that: In step (3), The temperature of the stirring reaction is 50 - 70 °C, and the time is 4 - 6 hours; The rotation speed of the centrifugation is 8000 - 12000 rpm, and the time is 30 - 40 minutes; The temperature of the drying is 70 - 90 °C, and the time is 10 - 15 hours.

9. The preparation method according to claim 6, characterized in that: Step (4) specifically includes: mixing diol and isocyanate, stirring and reacting for 1 - 1.5 hours in an inert atmosphere at 70 - 90 °C, adding dimethylolpropionic acid and butanone, maintaining the reaction at 70 - 80 °C for 2 - 3 hours, adding a chain extender and keeping the reaction at a certain temperature for 0.5 - 1.5 hours. After the chain extension is completed, adding hydroxyethyl methacrylate and reacting at 60 - 70 °C for 2 - 3 hours, adding triethylamine and reacting at 40 - 50 °C for 20 - 40 min, and then dispersing in water at room temperature for 20 - 30 minutes; then distilling off butanone under reduced pressure at a vacuum degree of 0.008 - 0.012 MPa for 1 - 1.5 hours at 40 - 45 °C to obtain an aqueous polyurethane emulsion.

10. The preparation method according to claim 6, characterized in that: Step (5) specifically includes: adding modified silica with a particle size of 60 - 100 nm to the aqueous polyurethane emulsion obtained in step (4), heating to 70 - 80 °C and then dropping acrylate monomer. After dropping for 50 - 70 min, adding modified silica with a particle size of 20 - 30 nm, keeping the temperature and continuing to drop acrylate monomer for 1 - 3 hours. After the dropping is completed, heating to 80 - 85 °C and reacting for 1 - 2 hours to obtain an inorganic particle-modified aqueous polyurethane resin.