Wear-resistant and aging-resistant polyurethane resin and preparation method thereof

Abstract

The present invention discloses a wear-resistant and aging-resistant polyurethane resin and its preparation method. The resin comprises the following raw materials, by weight: polyether polyol, diisocyanate, chain extender, modified composite particles, dispersant, ethyl acetate, leveling agent, ultraviolet absorber, light stabilizer 944, and catalyst. The polyurethane resin utilizes a multi-step surface modification process to prepare organically functionalized core-shell structured modified composite particles. Combined with an optimized preparation process, this method effectively overcomes the technical bottlenecks of conventional polyurethane modification, such as poor dispersibility of inorganic fillers, insufficient compatibility with the matrix, and the easy migration and loss of small molecule anti-aging additives. This significantly enhances the wear resistance, weathering resistance, and aging resistance of the polyurethane resin, extending its service life and protective effectiveness in outdoor or harsh environments.

Description

Technical Field

[0001] The invention belongs to the technical field of polyurethane resin coatings, and particularly relates to a wear-resistant and aging-resistant polyurethane resin and a preparation method thereof. Background Art

[0002] As a polymer material with high strength, tear resistance, and wear resistance, polyurethane resin is widely used in daily life, industrial and agricultural production, medicine and other fields. Polyurethane resin is gradually polymerized from raw materials such as polyisocyanates and polyols, and contains characteristic carbamate groups in the main chain. Due to its highly adjustable molecular structure, this type of polymer exhibits excellent physical and chemical properties, such as high strength, high toughness, excellent wear resistance, chemical resistance, and good adhesion to a variety of substrates. Especially in the field of coatings, polyurethane resin has become an important type of film-forming substance for high-performance coatings. It can be used to prepare a variety of coating products ranging from hard to flexible, from solvent-based to water-based or powder-based. It is widely used in many aspects such as wood, automobiles, construction, and industrial corrosion protection, providing excellent protection and decorative effects.

[0003] However, when conventional polyurethane resins are used to prepare coatings for outdoor or harsh environments, the coatings often struggle to meet the increasingly stringent requirements for wear resistance and weathering and aging resistance (particularly resistance to UV-induced degradation). Over time, the coatings are susceptible to wear, gloss loss, yellowing, cracking, and even powdering, significantly shortening their service life and protective effectiveness. To address these deficiencies, existing technologies often incorporate inorganic wear-resistant fillers (such as silica and alumina) or additives such as UV absorbers and hindered amine light stabilizers (HALS) into polyurethane coating formulations. However, these approaches have inherent drawbacks: inorganic fillers lack compatibility with the polyurethane resin matrix, making uniform nanoscale dispersion difficult and prone to agglomeration, potentially affecting the coating's transparency, gloss, and mechanical properties. Furthermore, small molecule anti-aging additives are prone to migration, volatility, and susceptibility to extraction by solvents or rainwater, leading to a reduction in the coating's long-term anti-aging properties.

[0004] Chinese patent application CN106009852A discloses a weather-resistant polyurethane coating, which is made from the following raw materials in parts by weight: 7-10 parts of polyamide resin, 5-8 parts of colloidal graphite powder, 8-10 parts of straw powder, 4-8 parts of barium sulfate, 11-16 parts of water-based acrylic resin, 30-44 parts of modified polyurethane resin, 4-7 parts of talc, 5-10 parts of silica sol, 7-12 parts of magnesium hydroxide, 6-10 parts of medical stone powder, 1-2 parts of antibacterial agent, 2-4 parts of pH regulator, 2-4 parts of dispersant, 4-8 parts of acrylic acid, 6-12 parts of nano-montmorillonite, and 5-8 parts of muscovite powder. The beneficial effects of this invention are: the polyurethane coating of this invention has excellent weather resistance, high hardness, and good aging resistance. However, the content of inorganic powder added in this patent is high, and the compatibility between the materials is poor, which may lead to insufficient mechanical properties of the polyurethane. Chinese patent CN106118360A discloses a kind of environmentally friendly wear-resistant anticorrosive coating and preparation method thereof, described coating comprises following composition: organosilicon modified epoxy resin, acrylic acid modified polyurethane resin, bentonite, talcum powder, rust-proof pigment, nano calcium carbonate, polyvinyl alcohol, titanate coupling agent, defoamer, dispersant, film-forming aid, thickener, leveling agent, isopropyl alcohol, deionized water.Described coating adopts organosilicon modified epoxy resin to coordinate acrylic acid modified polyurethane resin, epoxy resin and polyurethane resin after modification, make coating have good glossiness, good antistatic ability, good mechanical property, aging resistance and wear resistance, add rust-proof pigment, can effectively improve coating anticorrosive ability, and also have price and environmental protection advantage, strong adhesion, good ductility, high temperature resistance, long service life, adopt roller coating instead of spraying during coating, effectively improve production environment, be beneficial to workers' health.But the inorganic particles in the above-mentioned patent are directly added, and its dispersibility in polyurethane and its compatibility with polyurethane are insufficient, and may cause coating's wear resistance to be insufficient.

[0005] Therefore, the research and development of a polyurethane resin with excellent wear resistance and long-lasting anti-aging ability in this field to overcome the limitations of traditional modification methods in coating applications has great significance and application value. Summary of the Invention

[0006] In view of the deficiencies in the prior art, the present invention aims to provide a wear-resistant and anti-aging polyurethane resin and a preparation method thereof.

[0007] To achieve the above object, the present invention provides the following technical solutions:

[0008] A wear-resistant and anti-aging polyurethane resin, comprising the following raw materials in parts by weight:

[0009] 100-120 parts of polyether polyol, 35-45 parts of diisocyanate, 6-9 parts of chain extender, 14-18 parts of modified composite particles, 0.7-1 part of dispersant, 100-130 parts of ethyl acetate, 0.3-0.5 parts of leveling agent, 0.5-0.8 parts of UV absorber, 0.2-0.3 parts of light stabilizer 944, and 0.15-0.25 parts of catalyst;

[0010] The modified composite particles are prepared by coating titanium dioxide on the surface of silicon dioxide, modifying with γ-glycidyloxypropyltrimethoxysilane, then introducing 4-propyleneoxy-2-hydroxybenzophenone, and finally introducing 3,4,5,6-tetrahydro-2-pyrimidinethiol through a mercapto-ene reaction.

[0011] Preferably, a wear-resistant and anti-aging polyurethane resin comprises the following raw materials, by weight: 110-120 parts of polyether polyol, 35-45 parts of diisocyanate, 6-8 parts of chain extender, 16-18 parts of modified composite particles, 0.8-1 part of dispersant, 110-130 parts of ethyl acetate, 0.4-0.5 part of leveling agent, 0.5-0.7 part of ultraviolet absorber, and 0.15-0.2 part of catalyst.

[0012] Preferably, the polyether polyol is one or both of polypropylene glycol (molecular weight of 2000-3000) and polytetramethylene ether glycol (molecular weight of 2000-3000), the diisocyanate is one or both of isophorone diisocyanate IPDI and dicyclohexylmethane diisocyanate H12MDI, the chain extender is one or more of ethylene glycol, 1,4-butanediol, and 1,6-hexanediol, the dispersant is BYK-163, the leveling agent is one or more of BYK-333, BYK-354, and BYK-390, the ultraviolet absorber is one or more of UV-9, UV-531, and UVP-327, and the catalyst is dibutyltin dilaurate.

[0013] Preferably, the method for preparing the modified composite particles comprises the following steps:

[0014] S1. Adding silicon dioxide to deionized water, followed by adding tetrabutyl titanate and ammonia water, and performing a hydrothermal reaction. After the reaction is complete, filtering, washing, and drying to obtain composite particles;

[0015] S2, adding the composite particles prepared in step S1 to an ethanol aqueous solution, then adding γ-glycidyloxypropyltrimethoxysilane, stirring to react, and filtering, washing, and drying after the reaction is completed to obtain pretreated composite particles;

[0016] S3, adding the pretreated composite particles in step S2 to toluene, followed by adding 4-propyleneoxy-2-hydroxybenzophenone and triethylamine, and reacting at a constant temperature under a nitrogen atmosphere. After the reaction is completed, filtering, washing, and drying to obtain organic composite particles;

[0017] S4. Add the organized composite particles in step S3 to acetonitrile, then add 3,4,5,6-tetrahydro-2-pyrimidinethiol and photoinitiator-651, and carry out ultraviolet light reaction under a nitrogen atmosphere. After the reaction is completed, filter, wash, and dry to obtain modified composite particles.

[0018] Preferably, the mass fraction of the ammonia water in step S1 is 10-15%, the mass ratio of the silicon dioxide, deionized water, tetrabutyl titanate, and ammonia water is 60-70:900-1000:30-40:50-60, the temperature of the hydrothermal reaction is 120-150° C., and the time is 5-7 hours.

[0019] In the present invention, silica particles are used as the core. SiO2 has high hardness and good chemical stability, which can provide basic wear resistance. Titanium dioxide is then generated in situ on the silica surface by a hydrothermal method to obtain silica / titanium dioxide composite particles. The TiO2 on the surface itself has certain ultraviolet shielding ability and weather resistance, laying the foundation for subsequent functionalization.

[0020] Preferably, in step S2, the mass ratio of the composite particles to γ-glycidyloxypropyltrimethoxysilane is 70-80:8-12, the stirring reaction temperature is 50-60° C., and the time is 2-3 h.

[0021] In the present invention, the composite particles are modified with γ-glycidyloxypropyltrimethoxysilane, and epoxy functional groups are introduced into the surface to improve their compatibility with subsequent organic modifiers and the final polyurethane matrix, and provide reaction sites for subsequent chemical grafting.

[0022] Preferably, in step S3, the mass ratio of the pretreated composite particles, 4-propyleneoxy-2-hydroxybenzophenone, and triethylamine is 70-80:8-12:0.5-0.7, and the isothermal reaction temperature is 70-80° C. and the reaction time is 2-3 h.

[0023] In the present invention, 4-propyleneoxy-2-hydroxybenzophenone having a UV absorbing function is bonded to the particle surface by reacting an epoxy group with the hydroxyl group in 4-propyleneoxy-2-hydroxybenzophenone. The benzophenone structure can efficiently absorb UV rays in a specific wavelength band and dissipate the energy in the form of heat energy through intramolecular hydrogen bonding or isomerization, thereby protecting the polymer main chain from being destroyed by UV rays, achieving long-term UV protection, and preventing loss due to migration, volatilization, or extraction.

[0024] Preferably, the mass ratio of the organic composite particles, 3,4,5,6-tetrahydro-2-pyrimidinethiol, and photoinitiator-651 in step S4 is 80-90:4-6:0.2-0.3, and the conditions for the ultraviolet light reaction are: ultraviolet light intensity 20-25mW / cm 2 , temperature is 40-50℃, time is 1-2h.

[0025] In the present invention, 3,4,5,6-tetrahydro-2-pyrimidinethiol is introduced through a thiol-ene reaction. The nitrogen-sulfur heterocyclic structure in 3,4,5,6-tetrahydro-2-pyrimidinethiol has a function similar to that of a hindered amine light stabilizer, and can capture free radicals generated by light, heat, and oxygen, interrupt the degradation chain reaction of the polymer, and act as a light stabilizer. It complements 4-propyleneoxy-2-hydroxybenzophenone and can significantly improve the aging resistance of the polyurethane resin. At the same time, 3,4,5,6-tetrahydro-2-pyrimidinethiol contains two secondary amine groups, which can form a very strong hydrogen bond network with the polar groups of the polyurethane, achieving very good interfacial compatibility and bonding strength. In addition, the secondary amine groups may also react with residual -NCO in the polyurethane to form covalent bonds, thereby improving the interfacial bonding strength between the composite particles and the resin. Strong interfacial bonding can effectively improve the wear resistance of the material.

[0026] The present invention also protects a method for preparing the wear-resistant and aging-resistant polyurethane resin as described above, comprising the following steps:

[0027] The polyether polyol is dehydrated for 1-2 hours and then added to a reactor. Half of the ethyl acetate is then added, and under nitrogen protection, diisocyanate is added dropwise. After the addition is completed, the temperature is raised to a certain temperature, and a catalyst is added to react. After a period of reaction, a polyurethane prepolymer is obtained; a dispersant and modified composite particles are added to the other half of the ethyl acetate, and the mixture is mixed uniformly to obtain a particle dispersant; the polyurethane prepolymer and the particle dispersant are mixed uniformly, and then a chain extender, a leveling agent, an ultraviolet absorber and a light stabilizer 944 are added, and the reaction is carried out by heat preservation to obtain the wear-resistant and anti-aging polyurethane resin.

[0028] Preferably, the dehydration treatment is carried out at a vacuum degree of 500-800 Pa and a temperature of 100-110° C. for 1-2 hours; the heating temperature is 75-85° C. and the reaction time is 2-3 hours; the insulation reaction temperature is 50-60° C. and the reaction time is 2-3 hours.

[0029] Compared with the prior art, the present invention has the following beneficial effects:

[0030] (1) The wear-resistant and anti-aging polyurethane resin provided by the present invention introduces a multi-step surface modification to prepare organic functionalized core-shell structure modified composite particles, and combines it with an optimized preparation process to effectively overcome the technical bottlenecks of poor dispersibility of inorganic fillers, insufficient compatibility with the matrix, and easy migration and loss of small molecule anti-aging additives in traditional polyurethane modification, thereby significantly improving the wear resistance and weather resistance of the polyurethane resin and extending its service life and protective effect in outdoor or harsh environments.

[0031] (2) The wear-resistant and anti-aging polyurethane resin provided by the present invention uses silicon dioxide as a hard core to provide basic wear resistance and is coated with titanium dioxide to increase weather resistance; through γ-glycidyloxypropyltrimethoxysilane bridging, a benzophenone derivative with ultraviolet absorption ability (4-propyleneoxy-2-hydroxybenzophenone) and a pyrimidinethiol derivative with light stabilization (3,4,5,6-tetrahydro-2-pyrimidinethiol) are anchored on the particle surface in a chemical bonding manner. Through multi-step modification, not only the wear-resistant component and the anti-aging functional group are integrated into one, but more importantly, the migration and loss of the anti-aging additive are avoided through chemical bonding, thereby ensuring long-term effectiveness. At the same time, the introduction of organic groups improves the interface compatibility and dispersion uniformity between the particles and the polyurethane matrix, thereby ensuring the mechanical properties of the polyurethane resin.

[0032] (3) The wear-resistant and anti-aging polyurethane resin provided by the present invention is prepared by a prepolymer process. The polyurethane prepolymer is first synthesized, and the key modified composite particles are pre-mixed with a dispersant in a solvent to prepare a uniform particle dispersion. The particle dispersion is then mixed with the prepolymer and a chain extension reaction is performed. This method effectively avoids the uneven dispersion problem that may be caused by directly adding powder particles to the polyurethane system, ensures that the modified composite particles are evenly dispersed at the nanometer level in the polyurethane matrix, thereby giving full play to their synergistic enhancement effect and ensuring the stability and excellence of the performance of the final product. DETAILED DESCRIPTION

[0033] The following will clearly and completely describe the technical solutions of the present invention in conjunction with the embodiments of the present invention. Obviously, the embodiments described are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0034] Unless otherwise specified, the chemical reagents and materials in the present invention are purchased from commercial sources or synthesized from commercially purchased raw materials.

[0035] The particle size of the silicon dioxide is 200-300 nm; the molecular weight of the polytetramethylene ether glycol is 2000; and the molecular weight of the polypropylene glycol is 2000. Example 1

[0036] A wear-resistant and anti-aging polyurethane resin, comprising the following raw materials in parts by weight:

[0037] 110 parts of polytetramethylene ether glycol, 35 parts of isophorone diisocyanate, 8 parts of 1,4-butanediol, 16 parts of modified composite particles, 0.9 parts of dispersant BYK-163, 120 parts of ethyl acetate, 0.4 parts of BYK-333, 0.7 parts of UV-531, 0.25 parts of light stabilizer 944, and 0.2 parts of dibutyltin dilaurate.

[0038] The method for preparing the modified composite particles comprises the following steps:

[0039] S1. Add 65 g of silicon dioxide to 950 g of deionized water, then add 35 g of tetrabutyl titanate and 55 g of 15% ammonia water, and hydrothermally react at 140° C. for 6 h. After the reaction is completed, filter, wash, and dry to obtain composite particles;

[0040] S2. Add 75 g of the composite particles prepared in step S1 to 1 L of an ethanol-water solution (the volume ratio of ethanol to water is 3:1), then add 10 g of γ-glycidyloxypropyltrimethoxysilane, and stir at 55° C. for 2.5 h. After the reaction is complete, filter, wash, and dry to obtain pretreated composite particles.

[0041] S3, adding 75g of the pretreated composite particles from step S2 to 1L of toluene, followed by adding 10g of 4-propyleneoxy-2-hydroxybenzophenone and 0.6g of triethylamine, and reacting at 75°C under a nitrogen atmosphere for 2.5h. After the reaction is complete, filtering, washing, and drying to obtain organic composite particles;

[0042] S4: Add 85g of the organic composite particles from step S3 to 1L of acetonitrile, then add 5g of 3,4,5,6-tetrahydro-2-pyrimidinethiol and 0.25g of photoinitiator-651, and perform ultraviolet light reaction under nitrogen atmosphere with an external light intensity of 23mW / cm 2 , temperature is 45℃, time is 1.5h, after the reaction is completed, filter, wash and dry to obtain modified composite particles.

[0043] A method for preparing a wear-resistant and aging-resistant polyurethane resin comprises the following steps:

[0044] The polyether polyol was dehydrated at a vacuum degree of 600 Pa and a temperature of 105°C for 1.5 hours, and then added to a reactor equipped with a stirrer, a thermometer, a condenser and a nitrogen protection device. Then, half of the ethyl acetate was added, and under nitrogen protection, diisocyanate was added dropwise. After the addition was completed, the temperature was raised to 80°C, and a catalyst was added and reacted for 2.5 hours to obtain a polyurethane prepolymer; a dispersant and modified composite particles were added to the other half of the ethyl acetate, and mixed uniformly to obtain a particle dispersant; the polyurethane prepolymer and the particle dispersant were mixed uniformly, and then a chain extender, a leveling agent, an ultraviolet absorber and a light stabilizer 944 were added, and the mixture was kept warm at 55°C for 2.5 hours to obtain the wear-resistant and anti-aging polyurethane resin. Example 2

[0045] A wear-resistant and anti-aging polyurethane resin, comprising the following raw materials in parts by weight:

[0046] 100 parts of polypropylene glycol, 38 parts of isophorone diisocyanate, 6 parts of ethylene glycol, 14 parts of modified composite particles, 0.7 parts of dispersant BYK-163, 100 parts of ethyl acetate, 0.3 parts of BYK-354, 0.5 parts of UV-9, 0.2 parts of light stabilizer 944, and 0.15 parts of dibutyltin dilaurate.

[0047] The method for preparing the modified composite particles comprises the following steps:

[0048] S1. Add 60 g of silicon dioxide to 900 g of deionized water, then add 30 g of tetrabutyl titanate and 50 g of 10% ammonia water, and hydrothermally react at 120° C. for 7 h. After the reaction is completed, filter, wash, and dry to obtain composite particles;

[0049] S2. Add 70 g of the composite particles prepared in step S1 to 1 L of an ethanol-water solution (the volume ratio of ethanol to water is 3:1), then add 8 g of γ-glycidyloxypropyltrimethoxysilane, and stir at 50° C. for 3 h. After the reaction is complete, filter, wash, and dry to obtain pretreated composite particles.

[0050] S3, adding 70g of the pretreated composite particles in step S2 to 1L of toluene, followed by adding 8g of 4-propyleneoxy-2-hydroxybenzophenone and 0.5g of triethylamine, and reacting at 70°C under a nitrogen atmosphere for 3h. After the reaction is complete, filtering, washing, and drying to obtain organic composite particles;

[0051] S4: Add 80 g of the organic composite particles from step S3 to 1 L of acetonitrile, then add 4 g of 3,4,5,6-tetrahydro-2-pyrimidinethiol and 0.2 g of photoinitiator-651, and perform ultraviolet light reaction under nitrogen atmosphere with an external light intensity of 20 mW / cm 2, temperature is 40℃, time is 2h, after the reaction is completed, filter, wash and dry to obtain modified composite particles.

[0052] A method for preparing a wear-resistant and aging-resistant polyurethane resin comprises the following steps:

[0053] The polyether polyol is dehydrated at a vacuum degree of 800 Pa and a temperature of 100°C for 2 hours, and then added to a reactor equipped with a stirrer, a thermometer, a condenser and a nitrogen protection device, followed by adding half of the ethyl acetate. Under nitrogen protection, diisocyanate is added dropwise. After the addition is completed, the temperature is raised to 75°C, and a catalyst is added and reacted for 3 hours to obtain a polyurethane prepolymer; a dispersant and modified composite particles are added to the other half of the ethyl acetate, and mixed uniformly to obtain a particle dispersant; the polyurethane prepolymer and the particle dispersant are mixed uniformly, and then a chain extender, a leveling agent, an ultraviolet absorber and a light stabilizer 944 are added, and the mixture is kept warm at 50°C for 3 hours to obtain the wear-resistant and anti-aging polyurethane resin. Example 3

[0054] A wear-resistant and anti-aging polyurethane resin, comprising the following raw materials in parts by weight:

[0055] 120 parts of polytetramethylene ether glycol, 45 parts of dicyclohexylmethane diisocyanate, 9 parts of 1,6-hexanediol, 18 parts of modified composite particles, 1 part of dispersant BYK-163, 130 parts of ethyl acetate, 0.5 parts of BYK-390, 0.8 parts of UVP-327, 0.3 parts of light stabilizer 944, and 0.25 parts of dibutyltin dilaurate.

[0056] The method for preparing the modified composite particles comprises the following steps:

[0057] S1. Add 70 g of silicon dioxide to 1000 g of deionized water, then add 40 g of tetrabutyl titanate and 60 g of 15% ammonia water, and hydrothermally react at 150° C. for 5 h. After the reaction is completed, filter, wash, and dry to obtain composite particles;

[0058] S2. Add 80 g of the composite particles prepared in step S1 to 1 L of an ethanol-water solution (the volume ratio of ethanol to water is 3:1), then add 12 g of γ-glycidyloxypropyltrimethoxysilane, and stir at 60° C. for 2 h. After the reaction is complete, filter, wash, and dry to obtain pretreated composite particles.

[0059] S3, adding 80 g of the pretreated composite particles from step S2 to 1 L of toluene, followed by adding 12 g of 4-propyleneoxy-2-hydroxybenzophenone and 0.7 g of triethylamine, and reacting at 80° C. under a nitrogen atmosphere for 2 h. After the reaction is complete, filtering, washing, and drying to obtain organic composite particles;

[0060] S4: Add 90 g of the organic composite particles from step S3 to 1 L of acetonitrile, followed by 6 g of 3,4,5,6-tetrahydro-2-pyrimidinethiol and 0.3 g of photoinitiator-651, and perform ultraviolet light reaction under nitrogen atmosphere with an ultraviolet light intensity of 25 mW / cm 2 , temperature is 50℃, time is 1h, after the reaction is completed, filter, wash and dry to obtain modified composite particles.

[0061] A method for preparing a wear-resistant and aging-resistant polyurethane resin comprises the following steps:

[0062] The polyether polyol is dehydrated at a vacuum degree of 500 Pa and a temperature of 110°C for 1 hour, and then added to a reactor equipped with a stirrer, a thermometer, a condenser and a nitrogen protection device, followed by adding half of the ethyl acetate. Under nitrogen protection, diisocyanate is added dropwise. After the addition is completed, the temperature is raised to 85°C, and a catalyst is added and reacted for 2 hours to obtain a polyurethane prepolymer; a dispersant and modified composite particles are added to the other half of the ethyl acetate, and mixed uniformly to obtain a particle dispersant; the polyurethane prepolymer and the particle dispersant are mixed uniformly, and then a chain extender, a leveling agent, an ultraviolet absorber and a light stabilizer 944 are added, and the mixture is kept warm at 60°C for 2 hours to obtain the wear-resistant and anti-aging polyurethane resin. Comparative Example 1

[0063] A wear-resistant and anti-aging polyurethane resin, comprising the following raw materials in parts by weight:

[0064] 110 parts of polytetramethylene ether glycol, 35 parts of isophorone diisocyanate, 8 parts of 1,4-butanediol, 16 parts of modified composite particles, 0.9 parts of dispersant BYK-163, 120 parts of ethyl acetate, 0.4 parts of BYK-333, 0.7 parts of UV-531, 0.25 parts of light stabilizer 944, and 0.2 parts of dibutyltin dilaurate.

[0065] The method for preparing the modified composite particles comprises the following steps:

[0066] S1. Add 65 g of silicon dioxide to 950 g of deionized water, then add 35 g of tetrabutyl titanate and 55 g of 15% ammonia water, and hydrothermally react at 140° C. for 6 h. After the reaction is completed, filter, wash, and dry to obtain composite particles;

[0067] S2. Add 75 g of the composite particles prepared in step S1 to 1 L of an ethanol-water solution (the volume ratio of ethanol to water is 3:1), then add 10 g of γ-glycidyloxypropyltrimethoxysilane, and stir at 55° C. for 2.5 h. After the reaction is complete, filter, wash, and dry to obtain pretreated composite particles.

[0068] S3. Add 75 g of the pretreated composite particles in step S2 to 1 L of toluene, followed by adding 10 g of 4-propyleneoxy-2-hydroxybenzophenone and 0.6 g of triethylamine. The mixture is reacted at 75° C. under a nitrogen atmosphere for 2.5 h. After the reaction is completed, the mixture is filtered, washed, and dried to obtain modified composite particles.

[0069] A method for preparing a wear-resistant and aging-resistant polyurethane resin comprises the following steps:

[0070] The polyether polyol was dehydrated at a vacuum degree of 600 Pa and a temperature of 105°C for 1.5 hours, and then added to a reactor equipped with a stirrer, a thermometer, a condenser and a nitrogen protection device. Then, half of the ethyl acetate was added, and under nitrogen protection, diisocyanate was added dropwise. After the addition was completed, the temperature was raised to 80°C, and a catalyst was added and reacted for 2.5 hours to obtain a polyurethane prepolymer; a dispersant and modified composite particles were added to the other half of the ethyl acetate, and mixed uniformly to obtain a particle dispersant; the polyurethane prepolymer and the particle dispersant were mixed uniformly, and then a chain extender, a leveling agent, an ultraviolet absorber and a light stabilizer 944 were added, and the mixture was kept warm at 55°C for 2.5 hours to obtain the wear-resistant and anti-aging polyurethane resin.

[0071] Compared with Example 1, in this comparative example, 3,4,5,6-tetrahydro-2-pyrimidinethiol was not introduced into the modified composite particles. Comparative Example 2

[0072] A wear-resistant and anti-aging polyurethane resin, comprising the following raw materials in parts by weight:

[0073] 110 parts of polytetramethylene ether glycol, 35 parts of isophorone diisocyanate, 8 parts of 1,4-butanediol, 16 parts of modified composite particles, 0.9 parts of dispersant BYK-163, 120 parts of ethyl acetate, 0.4 parts of BYK-333, 0.7 parts of UV-531, 0.25 parts of light stabilizer 944, and 0.2 parts of dibutyltin dilaurate.

[0074] The method for preparing the modified composite particles comprises the following steps:

[0075] S1. Add 65 g of silicon dioxide to 950 g of deionized water, then add 35 g of tetrabutyl titanate and 55 g of 15% ammonia water, and hydrothermally react at 140° C. for 6 h. After the reaction is completed, filter, wash, and dry to obtain composite particles;

[0076] S2. Add 75 g of the composite particles prepared in step S1 to 1 L of an ethanol-water solution (the volume ratio of ethanol to water is 3:1), then add 10 g of γ-glycidyloxypropyltrimethoxysilane, and stir at 55° C. for 2.5 h. After the reaction is complete, filter, wash, and dry to obtain pretreated composite particles.

[0077] S3. Add 75 g of the pretreated composite particles in step S2 to 1 L of toluene, then add 5 g of 3,4,5,6-tetrahydro-2-pyrimidinethiol and 0.6 g of triethylamine, and react at 75° C. under a nitrogen atmosphere for 2.5 h. After the reaction is completed, filter, wash, and dry to obtain modified composite particles.

[0078] A method for preparing a wear-resistant and aging-resistant polyurethane resin comprises the following steps:

[0079] The polyether polyol was dehydrated at a vacuum degree of 600 Pa and a temperature of 105°C for 1.5 hours, and then added to a reactor equipped with a stirrer, a thermometer, a condenser and a nitrogen protection device. Then, half of the ethyl acetate was added, and under nitrogen protection, diisocyanate was added dropwise. After the addition was completed, the temperature was raised to 80°C, and a catalyst was added and reacted for 2.5 hours to obtain a polyurethane prepolymer; a dispersant and modified composite particles were added to the other half of the ethyl acetate, and mixed uniformly to obtain a particle dispersant; the polyurethane prepolymer and the particle dispersant were mixed uniformly, and then a chain extender, a leveling agent, an ultraviolet absorber and a light stabilizer 944 were added, and the mixture was kept warm at 55°C for 2.5 hours to obtain the wear-resistant and anti-aging polyurethane resin.

[0080] Compared with Example 1, this comparative example does not introduce 4-propyleneoxy-2-hydroxybenzophenone into the modified composite particles. Comparative Example 3

[0081] A wear-resistant and anti-aging polyurethane resin, comprising the following raw materials in parts by weight:

[0082] 110 parts of polytetramethylene ether glycol, 35 parts of isophorone diisocyanate, 8 parts of 1,4-butanediol, 16 parts of modified composite particles, 0.9 parts of dispersant BYK-163, 120 parts of ethyl acetate, 0.4 parts of BYK-333, 0.7 parts of UV-531, 0.25 parts of light stabilizer 944, and 0.2 parts of dibutyltin dilaurate.

[0083] The method for preparing the modified composite particles comprises the following steps:

[0084] S1. Add 65 g of silicon dioxide to 950 g of deionized water, then add 35 g of tetrabutyl titanate and 55 g of 15% ammonia water, and hydrothermally react at 140° C. for 6 h. After the reaction is completed, filter, wash, and dry to obtain composite particles;

[0085] S2. Evenly mix 75 g of the composite particles prepared in step S1 with 10 g of 4-propyleneoxy-2-hydroxybenzophenone and 5 g of 3,4,5,6-tetrahydro-2-pyrimidinethiol to obtain modified composite particles.

[0086] A method for preparing a wear-resistant and aging-resistant polyurethane resin comprises the following steps:

[0087] The polyether polyol was dehydrated at a vacuum degree of 600 Pa and a temperature of 105°C for 1.5 hours, and then added to a reactor equipped with a stirrer, a thermometer, a condenser and a nitrogen protection device. Then, half of the ethyl acetate was added, and under nitrogen protection, diisocyanate was added dropwise. After the addition was completed, the temperature was raised to 80°C, and a catalyst was added and reacted for 2.5 hours to obtain a polyurethane prepolymer; a dispersant and modified composite particles were added to the other half of the ethyl acetate, and mixed uniformly to obtain a particle dispersant; the polyurethane prepolymer and the particle dispersant were mixed uniformly, and then a chain extender, a leveling agent, an ultraviolet absorber and a light stabilizer 944 were added, and the mixture was kept warm at 55°C for 2.5 hours to obtain the wear-resistant and anti-aging polyurethane resin.

[0088] Compared with Example 1, in this comparative example, 4-propyleneoxy-2-hydroxybenzophenone and 3,4,5,6-tetrahydro-2-pyrimidinethiol were modified with the composite particles by physical blending.

[0089] The wear-resistant and aging-resistant polyurethane resins prepared in Examples 1-3 and Comparative Examples 1-3 were added to a mold and vacuum-dried at 80° C. to form a film 1.5 mm thick. Performance tests were performed, wherein the tensile strength and elongation at break were tested according to the standard GB / T 1040.3-2006 "Determination of tensile properties of plastics - Part 3: Test conditions for films and sheets", with a tensile rate of 50 mm / min. The wear resistance was tested according to the standard GB / T 1768-2006 "Paints and varnishes - Determination of abrasion resistance - Rotating rubber grinding wheel method", with a CS-10 wheel used for the abrasion resistance test. The UV aging resistance test was performed according to the standard GB / T 23987-2009, with an irradiation wavelength of 340 nm, a temperature of 50° C., and a time of 240 h. The tensile strength retention rate and elongation at break retention rate of the aged samples were tested. The test results are shown in Table 1 below.

[0090] Table 1

[0091]

[0092] As can be seen from Table 1 above, the wear-resistant and aging-resistant polyurethane resin prepared in the present invention has good wear resistance and excellent aging resistance, as well as good mechanical properties, and has good application prospects.

[0093] The above content is a further detailed description of the present invention in combination with specific implementation examples. It cannot be determined that the specific implementation of the present invention is limited to these descriptions. For ordinary technicians in the technical field to which the present invention belongs, they can make several simple deductions or substitutions without departing from the concept of the present invention, which should be regarded as falling within the scope of protection of the present invention.

[0094] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A wear-resistant and anti-aging polyurethane resin, characterized in that: Calculated by weight, it includes the following raw materials: 100-120 parts of polyether polyol, 30-40 parts of diisocyanate, 6-9 parts of chain extender, 14-18 parts of modified composite particles, 0.7-1 part of dispersant, 100-130 parts of ethyl acetate, 0.3-0.5 parts of leveling agent, 0.5-0.8 parts of UV absorber, 0.2-0.3 parts of light stabilizer 944, and 0.15-0.25 parts of catalyst; The preparation method of the modified composite particles comprises the following steps: S1. Adding silicon dioxide to deionized water, followed by adding tetrabutyl titanate and ammonia water, and performing a hydrothermal reaction to obtain composite particles; S2, adding the composite particles to an ethanol aqueous solution, and then adding γ-glycidyloxypropyltrimethoxysilane, stirring and reacting to obtain pretreated composite particles; S3, adding the pretreated composite particles to toluene, followed by adding 4-propyleneoxy-2-hydroxybenzophenone and triethylamine, and reacting at a constant temperature under a nitrogen atmosphere to obtain organic composite particles; S4. Add the organized composite particles to acetonitrile, then add 3,4,5,6-tetrahydro-2-pyrimidinethiol and photoinitiator-651, and perform ultraviolet light reaction under a nitrogen atmosphere to obtain modified composite particles.

2. The wear-resistant and aging-resistant polyurethane resin according to claim 1, characterized in that: The polyether polyol is one or both of polypropylene glycol and polytetramethylene glycol, the diisocyanate is one or both of isophorone diisocyanate IPDI and dicyclohexylmethane diisocyanate H12MDI, the chain extender is one or more of ethylene glycol, 1,4-butanediol, and 1,6-hexanediol, the dispersant is BYK-163, the leveling agent is one or more of BYK-333, BYK-354, and BYK-390, the ultraviolet absorber is one or more of UV-9, UV-531, and UVP-327, and the catalyst is dibutyltin dilaurate.

3. The wear-resistant and aging-resistant polyurethane resin according to claim 1, characterized in that: The mass fraction of the ammonia water in step S1 is 10-15%, the mass ratio of the silicon dioxide, deionized water, tetrabutyl titanate, and ammonia water is 60-70:900-1000:30-40:50-60, the temperature of the hydrothermal reaction is 120-150° C., and the time is 5-7 hours.

4. The wear-resistant and aging-resistant polyurethane resin according to claim 1, characterized in that: In step S2, the mass ratio of the composite particles to γ-glycidyloxypropyltrimethoxysilane is 70-80:8-12, the stirring reaction temperature is 50-60° C., and the time is 2-3 hours.

5. The wear-resistant and aging-resistant polyurethane resin according to claim 1, characterized in that: In step S3, the mass ratio of the pretreated composite particles, 4-propyleneoxy-2-hydroxybenzophenone, and triethylamine is 70-80:8-12:0.5-0.7, and the isothermal reaction temperature is 70-80° C. and the reaction time is 2-3 hours.

6. The wear-resistant and aging-resistant polyurethane resin according to claim 1, characterized in that: The mass ratio of the organic composite particles, 3,4,5,6-tetrahydro-2-pyrimidinethiol, and photoinitiator-651 in step S4 is 80-90:4-6:0.2-0.3, and the conditions for the ultraviolet light reaction are: ultraviolet light intensity 20-25mW / cm 2 , temperature is 40-50℃, time is 1-2h.

7. A method for preparing a wear-resistant and aging-resistant polyurethane resin, for preparing the wear-resistant and aging-resistant polyurethane resin according to any one of claims 1 to 6, characterized in that: The following steps are involved: The polyether polyol is dehydrated for 1-2 hours and then added to a reactor. Half of the ethyl acetate is then added, and under nitrogen protection, diisocyanate is added dropwise. After the addition is completed, the temperature is increased, and a catalyst is added to react. After a period of reaction, a polyurethane prepolymer is obtained; a dispersant and modified composite particles are added to the other half of the ethyl acetate and mixed uniformly to obtain a particle dispersant; the polyurethane prepolymer and the particle dispersant are mixed uniformly, and then a chain extender, a leveling agent, an ultraviolet absorber and a light stabilizer 944 are added and the reaction is carried out by heat preservation to obtain the wear-resistant and anti-aging polyurethane resin.

8. The method for preparing the wear-resistant and aging-resistant polyurethane resin according to claim 7, characterized in that: The dehydration treatment is carried out at a vacuum degree of 500-800 Pa and a temperature of 100-110° C. for 1-2 hours; the heating temperature is 75-85° C. and the reaction time is 2-3 hours; the insulation reaction temperature is 50-60° C. and the reaction time is 2-3 hours.

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