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

Abstract

The invention discloses wear-resistant anti-aging polyurethane resin and a preparation method thereof, and the wear-resistant anti-aging polyurethane resin is prepared from the following raw materials in parts by weight: 100 to 120 parts of polyether polyol, 30 to 40 parts of diisocyanate, 6 to 9 parts of chain extender, 14 to 18 parts of modified composite particles, 0.7 to 1 part of dispersing agent, 100 to 130 parts of ethyl acetate, 0.3 to 0.5 part of flatting agent, 0.5 to 0.8 part of ultraviolet absorbent, 0.2 to 0.3 part of light stabilizer 944 and 0.15 to 0.25 part of catalyst. According to the polyurethane resin, organic functionalized core-shell structure modified composite particles are prepared by introducing multi-step surface modification, and an optimized preparation process is combined, so that the technical bottlenecks that in traditional polyurethane modification, inorganic filler is poor in dispersity and insufficient in compatibility with a matrix, and micromolecular anti-aging auxiliaries are prone to migration and loss are effectively overcome; the wear resistance, weather resistance and aging resistance of the polyurethane resin are remarkably improved, and the service life and the protection effect of the polyurethane resin in the outdoor or severe environment are prolonged.

Description

Technical Field

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

[0002] As a kind of polymer material with high strength, tear resistance, wear resistance and other characteristics, 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 the main chain contains characteristic urethane groups. Because of the highly adjustable molecular structure of this kind of polymer, it 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 film-forming substance for high-performance coatings, and can prepare various coating products from hard to flexible, from solvent-based to water-based or powder-based, and is widely used in woodware, automobiles, buildings, industrial anti-corrosion and other aspects, providing excellent protection and decorative effects.

[0003] However, when traditional polyurethane resin is used to prepare coatings and applied to outdoor or harsh environments, the wear resistance and weather resistance and anti-aging performance of its coatings (especially resistance to degradation caused by ultraviolet rays) often fail to meet the increasingly high requirements. After long-term use, phenomena such as coating wear, loss of gloss, yellowing, cracking and even powdering are likely to occur, significantly shortening the service life and protection effect of the coating. To improve these deficiencies, the prior art often adds inorganic wear-resistant fillers (such as silica, alumina, etc.) or additives such as ultraviolet absorbers and hindered amine light stabilizers (HALS) to the polyurethane coating formulation. However, these methods have inherent defects: the compatibility between the inorganic filler and the polyurethane resin matrix is poor, it is difficult to achieve nano-level uniform dispersion, and it is easy to agglomerate, which may affect the transparency, gloss and mechanical properties of the coating; while small molecule anti-aging additives have problems such as easy migration, easy volatilization, and easy extraction and loss by solvents or rainwater, resulting in the attenuation of the long-term anti-aging performance of the coating.

[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 waterborne acrylic resin, 30-44 parts of modified polyurethane resin, 4-7 parts of talcum powder, 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 as follows: The polyurethane coating of this invention has excellent weather resistance, high hardness, and good anti-aging performance. However, the content of inorganic powder added in this patent is relatively high, and the compatibility between materials is poor, which may lead to insufficient mechanical properties of the polyurethane. Chinese Patent CN106118360A discloses an environmentally friendly wear-resistant and anticorrosive coating and its preparation method. The coating includes the following components: organosilicon-modified epoxy resin, acrylic acid-modified polyurethane resin, bentonite, talcum powder, rust-inhibiting pigment, nano-calcium carbonate, polyvinyl alcohol, titanate coupling agent, defoaming agent, dispersant, film-forming aid, thickening agent, leveling agent, isopropanol, and deionized water. The coating uses organosilicon-modified epoxy resin in combination with acrylic acid-modified polyurethane resin. After modification, the epoxy resin and polyurethane resin endow the coating with good gloss, good antistatic ability, better mechanical properties, anti-aging performance, and wear resistance. Adding rust-inhibiting pigments can effectively improve the anti-corrosion ability of the coating. Moreover, it also has price and environmental advantages, strong adhesion, good ductility, high temperature resistance, and long service life. When applying the coating, roller coating is used instead of spraying, which effectively improves the production environment and is beneficial to the health of workers. However, the inorganic particles in the above patent are directly added, and their dispersibility and compatibility with polyurethane are insufficient, which may lead to insufficient wear resistance of the coating.

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

[0006] Aiming at the deficiencies of the prior art, the purpose of the present invention is to provide a wear-resistant and anti-aging polyurethane resin and its preparation method.

[0007] To achieve the above purpose, the present invention provides the following technical solutions: A wear-resistant and anti-aging polyurethane resin, by weight, includes the following raw materials: 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 part of leveling agent, 0.5 - 0.8 part of ultraviolet absorber, 0.2 - 0.3 part of light stabilizer 944, 0.15 - 0.25 part of catalyst; The modified composite particles are prepared by coating titanium dioxide on the surface of silica, modifying with γ - glycidoxypropyltrimethoxysilane, then introducing 4 - allyloxy - 2 - hydroxybenzophenone, and finally introducing 3,4,5,6 - tetrahydro - 2 - pyrimidinethiol through thiol - ene reaction.

[0008] Preferably, a wear - resistant and anti - aging polyurethane resin, by weight, comprises the following raw materials: 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, 0.15 - 0.2 part of catalyst.

[0009] Preferably, the polyether polyol is one or two of polypropylene glycol (molecular weight 2000 - 3000) and polytetrahydrofuran ether glycol (molecular weight 2000 - 3000), the diisocyanate is one or two of isophorone diisocyanate IPDI and dicyclohexylmethane diisocyanate H12MDI, the chain extender is one or several of ethylene glycol, 1,4 - butanediol, 1,6 - hexanediol, the dispersant is BYK - 163, the leveling agent is one or several of BYK - 333, BYK - 354, BYK - 390, the ultraviolet absorber is one or several of UV - 9, UV - 531, UVP - 327, and the catalyst is dibutyltin dilaurate.

[0010] Preferably, the preparation method of the modified composite particles comprises the following steps: S1. Add silica into deionized water, then add tetrabutyl titanate and ammonia water, carry out hydrothermal reaction, after the reaction is completed, filter, wash and dry to obtain composite particles; S2. Add the composite particles in step S1 into an ethanol aqueous solution, then add γ - glycidoxypropyltrimethoxysilane, carry out stirring reaction, after the reaction is completed, filter, wash and dry to obtain pretreated composite particles; S3. Add the pretreated composite particles in step S2 into toluene, then add 4 - allyloxy - 2 - hydroxybenzophenone and triethylamine, carry out constant - temperature reaction under a nitrogen atmosphere, after the reaction is completed, filter, wash and dry to obtain organically modified composite particles; S4. Add the organic composite particles in step S3 into acetonitrile, then add 3,4,5,6-tetrahydro-2-pyrimidinethiol and photoinitiator-651, and carry out an ultraviolet light irradiation reaction under a nitrogen atmosphere. After the reaction is completed, filter, wash, and dry to obtain modified composite particles.

[0011] Preferably, in step S1, the mass fraction of the ammonia water 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 h.

[0012] In the present invention, using silicon dioxide particles as the core, SiO 2 has high hardness and good chemical stability, and can provide basic wear resistance. Subsequently, titanium dioxide is in-situ generated on the surface of silicon dioxide by the hydrothermal method to obtain silicon dioxide / titanium dioxide composite particles. The TiO on the surface 2 itself has certain ultraviolet shielding ability and weather resistance, laying a foundation for subsequent functionalization.

[0013] Preferably, in step S2, the mass ratio of the composite particles to γ-glycidoxypropyltrimethoxysilane is 70-80:8-12, the temperature of the stirring reaction is 50-60 °C, and the time is 2-3 h.

[0014] In the present invention, γ-glycidoxypropyltrimethoxysilane is used to modify the composite particles, and epoxy functional groups are introduced on the surface to improve its compatibility with subsequent organic modifiers and the final polyurethane matrix, and provide reaction sites for subsequent chemical grafting.

[0015] Preferably, in step S3, the mass ratio of the pretreated composite particles, 4-acryloxy-2-hydroxybenzophenone, and triethylamine is 70-80:8-12:0.5-0.7, the temperature of the constant temperature reaction is 70-80 °C, and the time is 2-3 h.

[0016] In the present invention, through the reaction of the epoxy group with the hydroxyl group in 4-acryloxy-2-hydroxybenzophenone, 4-acryloxy-2-hydroxybenzophenone with ultraviolet absorption function is bonded to the particle surface. The benzophenone structure can efficiently absorb ultraviolet rays in a specific wavelength band, and dissipate the energy in the form of heat through intramolecular hydrogen bonding or isomerization, etc., to protect the polymer main chain from being damaged by ultraviolet rays, achieve long-term ultraviolet protection, and prevent it from being lost due to migration, volatilization, or extraction.

[0017] 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 irradiation reaction are: ultraviolet light intensity of 20-25 mW / cm 2 , temperature of 40-50 °C, and time of 1-2 h.

[0018] 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, which can capture free radicals generated by light, heat, and oxygen, interrupt the degradation chain reaction of the polymer, and play the role of a light stabilizer. It forms a complement with 4-propenyloxy-2-hydroxybenzophenone, which 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 binding force. In addition, the secondary amine group may also react with the residual -NCO in the polyurethane to form a covalent bond, improving the interfacial bonding strength between the composite particles and the resin. The strong interfacial bonding can effectively improve the wear resistance of the material.

[0019] The present invention also protects a preparation method of the wear-resistant and anti-aging polyurethane resin as described above, including the following steps: The polyether polyol is dehydrated for 1-2 h, then added to a reaction kettle, and then half of the ethyl acetate is added. Under nitrogen protection, diisocyanate is added dropwise. After the dropwise addition is completed, the temperature is raised to a certain temperature, and a catalyst is added for reaction. After reacting for a period of time, a polyurethane prepolymer is obtained. Dispersant and modified composite particles are added to the other half of the ethyl acetate and mixed evenly to obtain a particle dispersant. The polyurethane prepolymer and the particle dispersant are mixed evenly, and then a chain extender, a leveling agent, an ultraviolet absorber, and a light stabilizer 944 are added for heat preservation reaction to obtain the wear-resistant and anti-aging polyurethane resin.

[0020] 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 h; the temperature for heating up is 75-85 °C, and the reaction time is 2-3 h; the temperature for the heat preservation reaction is 50-60 °C, and the time is 2-3 h.

[0021] Compared with the prior art, the present invention has the following beneficial effects: (1)The wear-resistant and anti-aging polyurethane resin provided by the present invention effectively overcomes the technical bottlenecks of poor dispersion of inorganic fillers and insufficient compatibility with the matrix in traditional polyurethane modification, as well as the easy migration and loss of small molecule anti-aging additives by introducing multi-step surface modification to prepare organically functionalized core-shell structure modified composite particles and combining with an optimized preparation process. It significantly improves the wear resistance and weather resistance and anti-aging performance of the polyurethane resin, and extends its service life and protection effect in outdoor or harsh environments.

[0022] (2)The wear-resistant and anti-aging polyurethane resin provided by the present invention uses silica as the hard core to provide basic wear resistance, and coats titanium dioxide to increase weather resistance; through the bridging of γ-glycidoxypropyltrimethoxysilane, benzophenone derivatives with ultraviolet absorption ability (4-propenyloxy-2-hydroxybenzophenone) and pyrimidine thiol derivatives with photo-stabilizing effect (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 components and anti-aging functional groups are integrated into one, but more importantly, the migration and loss of anti-aging additives are avoided through chemical bonding, ensuring long-term effectiveness. At the same time, the introduction of organic groups improves the interfacial compatibility and dispersion uniformity between the particles and the polyurethane matrix, ensuring the mechanical properties of the polyurethane resin.

[0023] (3)The wear-resistant and anti-aging polyurethane resin provided by the present invention, through the prepolymer process, first synthesizes a polyurethane prepolymer, and at the same time prepares a uniform particle dispersion by pre-mixing the key modified composite particles with a dispersant in a solvent. Subsequently, the particle dispersion is mixed with the prepolymer, and then a chain extension reaction is carried out. This method effectively avoids the problem of uneven dispersion that may be caused by directly adding powder particles in the polyurethane system, ensures the nano-level uniform dispersion of the modified composite particles in the polyurethane matrix, and thus fully exerts their synergistic strengthening effect, ensuring the stability and excellence of the performance of the final product. Specific Embodiments

[0024] The technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative work fall within the scope of protection of the present invention.

[0025] Unless otherwise specified, the chemical reagents and materials in the present invention are purchased through market channels or synthesized from raw materials purchased through market channels.

[0026] The particle size of the silica is 200 - 300 nm; the molecular weight of the polytetrahydrofuran ether diol is 2000; the molecular weight of the polypropylene glycol is 2000. Example 1

[0027] A wear-resistant and anti-aging polyurethane resin, by weight, comprises the following raw materials: 110 parts of polytetrahydrofuran ether glycol, 35 parts of isophorone diisocyanate, 8 parts of 1,4-butanediol, 16 parts of modified composite particles, 0.9 part of dispersant BYK-163, 120 parts of ethyl acetate, 0.4 part of BYK-333, 0.7 part of UV-531, 0.25 part of light stabilizer 944, 0.2 part of dibutyltin dilaurate.

[0028] Among them, the preparation method of the modified composite particles comprises the following steps: S1. Add 65 g of silicon dioxide into 950 g of deionized water, then add 35 g of tetrabutyl titanate and 55 g of ammonia water with a mass concentration of 15%, carry out hydrothermal reaction at 140 °C for 6 h, after the reaction is completed, filter, wash and dry to obtain composite particles; S2. Add 75 g of the composite particles in step S1 into 1 L of ethanol aqueous solution (volume ratio of ethanol to water is 3:1), then add 10 g of γ-glycidoxypropyltrimethoxysilane, stir and react at 55 °C for 2.5 h, after the reaction is completed, filter, wash and dry to obtain pretreated composite particles; S3. Add 75 g of the pretreated composite particles in step S2 into 1 L of toluene, then add 10 g of 4-propenoxy-2-hydroxybenzophenone and 0.6 g of triethylamine, carry out a constant temperature reaction at 75 °C for 2.5 h under a nitrogen atmosphere, after the reaction is completed, filter, wash and dry to obtain organically modified composite particles; S4. Add 85 g of the organically modified composite particles in step S3 into 1 L of acetonitrile, then add 5 g of 3,4,5,6-tetrahydro-2-pyrimidinethiol and 0.25 g of photoinitiator-651, carry out ultraviolet light irradiation reaction under a nitrogen atmosphere, the external light intensity is 23 mW / cm 2 , the temperature is 45 °C, and the time is 1.5 h. After the reaction is completed, filter, wash and dry to obtain modified composite particles.

[0029] A preparation method of a wear-resistant and anti-aging polyurethane resin, comprises the following steps: The polyether polyol was dehydrated at a vacuum degree of 600 Pa and a temperature of 105 °C for 1.5 h, and then added into a reaction kettle equipped with a stirrer, a thermometer, a condenser and a nitrogen protection device. Then, half of the ethyl acetate was added. Under nitrogen protection, the diisocyanate was added dropwise. After the dropwise addition was completed, the temperature was raised to 80 °C, and a catalyst was added. The reaction was carried out for 2.5 h to obtain a polyurethane prepolymer; a dispersant and modified composite particles were added to the other half of the ethyl acetate and mixed evenly to obtain a particle dispersant; the polyurethane prepolymer and the particle dispersant were mixed evenly, and then a chain extender, a leveling agent, a UV absorber and a light stabilizer 944 were added, and the reaction was carried out at 55 °C for 2.5 h to obtain the wear-resistant and anti-aging polyurethane resin. Example 2

[0030] A wear-resistant and anti-aging polyurethane resin, by weight, comprises the following raw materials: 100 parts of polypropylene glycol, 38 parts of isophorone diisocyanate, 6 parts of ethylene glycol, 14 parts of modified composite particles, 0.7 part of dispersant BYK-163, 100 parts of ethyl acetate, 0.3 part of BYK-354, 0.5 part of UV-9, 0.2 part of light stabilizer 944, 0.15 part of dibutyltin dilaurate.

[0031] Among them, the preparation method of the modified composite particles comprises the following steps: S1. Add 60 g of silicon dioxide into 900 g of deionized water, then add 30 g of tetrabutyl titanate and 50 g of ammonia water with a mass concentration of 10%. Carry out hydrothermal reaction at 120 °C for 7 h. After the reaction is completed, filter, wash and dry to obtain composite particles; S2. Add 70 g of the composite particles in step S1 into 1 L of an ethanol aqueous solution (the volume ratio of ethanol to water is 3:1), then add 8 g of γ-glycidoxypropyltrimethoxysilane, and carry out stirring reaction at 50 °C for 3 h. After the reaction is completed, filter, wash and dry to obtain pretreated composite particles; S3. Add 70 g of the pretreated composite particles in step S2 into 1 L of toluene, then add 8 g of 4-propenoxy-2-hydroxybenzophenone and 0.5 g of triethylamine. Carry out a constant temperature reaction at 70 °C for 3 h under a nitrogen atmosphere. After the reaction is completed, filter, wash and dry to obtain organically modified composite particles; S4. Add 80 g of the organically modified composite particles in step S3 into 1 L of acetonitrile, then add 4 g of 3,4,5,6-tetrahydro-2-pyrimidinethiol and 0.2 g of photoinitiator-651. Carry out an ultraviolet light irradiation reaction under a nitrogen atmosphere, with an external light intensity of 20 mW / cm 2 , a temperature of 40 °C, and a time of 2 h. After the reaction is completed, filter, wash and dry to obtain modified composite particles.

[0032] A preparation method of wear-resistant and anti-aging polyurethane resin, comprising the following steps: The polyether polyol is dehydrated at a vacuum degree of 800 Pa and a temperature of 100 °C for 2 h, and then added into a reaction kettle equipped with a stirrer, a thermometer, a condenser and a nitrogen protection device. Then, half of the ethyl acetate is added. Under nitrogen protection, the diisocyanate is added dropwise. After the dropwise addition is completed, the temperature is raised to 75 °C, and a catalyst is added, and the reaction is carried out for 3 h to obtain a polyurethane prepolymer; a dispersant and modified composite particles are added to the other half of the ethyl acetate, and mixed evenly to obtain a particle dispersant; the polyurethane prepolymer and the particle dispersant are mixed evenly, and then a chain extender, a leveling agent, an ultraviolet absorber and a light stabilizer 944 are added, and the reaction is carried out at 50 °C for 3 h to obtain the wear-resistant and anti-aging polyurethane resin. Example 3

[0033] A wear-resistant and anti-aging polyurethane resin, by weight, comprising the following raw materials: 120 parts of polytetrahydrofuran ether diol, 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 part of BYK-390, 0.8 part of UVP-327, 0.3 part of light stabilizer 944, 0.25 part of dibutyltin dilaurate.

[0034] Among them, the preparation method of the modified composite particles comprises the following steps: S1. Add 70 g of silica into 1000 g of deionized water, then add 40 g of tetrabutyl titanate and 60 g of ammonia water with a mass concentration of 15%, and carry out a hydrothermal reaction at 150 °C for 5 h. After the reaction is completed, filter, wash and dry to obtain composite particles; S2. Add 80 g of the composite particles in step S1 into 1 L of an ethanol aqueous solution (the volume ratio of ethanol to water is 3:1), then add 12 g of γ-glycidoxypropyltrimethoxysilane, and carry out a stirring reaction at 60 °C for 2 h. After the reaction is completed, filter, wash and dry to obtain pretreated composite particles; S3. Add 80 g of the pretreated composite particles in step S2 into 1 L of toluene, then add 12 g of 4-propenoxy-2-hydroxybenzophenone and 0.7 g of triethylamine, and carry out a constant temperature reaction at 80 °C for 2 h under a nitrogen atmosphere. After the reaction is completed, filter, wash and dry to obtain organic composite particles; S4. Add 90 g of the organic composite particles in step S3 into 1 L of acetonitrile, then add 6 g of 3,4,5,6-tetrahydro-2-pyrimidinethiol and 0.3 g of photoinitiator-651, and carry out an ultraviolet light irradiation reaction under a nitrogen atmosphere, and the ultraviolet light intensity is 25 mW / cm 2, at a temperature of 50 °C and a time of 1 h, after the reaction is completed, filter, wash, and dry to obtain the modified composite particles.

[0035] A preparation method of a wear-resistant and anti-aging polyurethane resin, comprising the following steps: Dehydrate the polyether polyol under a vacuum of 500 Pa and a temperature of 110 °C for 1 h, then add it to a reaction kettle equipped with a stirrer, a thermometer, a condenser, and a nitrogen protection device. Then add half of the ethyl acetate. Under nitrogen protection, dropwise add the diisocyanate. After the dropwise addition is completed, raise the temperature to 85 °C and add a catalyst, and react for 2 h to obtain a polyurethane prepolymer; add a dispersant and the modified composite particles to the other half of the ethyl acetate, mix evenly to obtain a particle dispersant; mix the polyurethane prepolymer and the particle dispersant evenly, then add a chain extender, a leveling agent, a UV absorber, and a light stabilizer 944, and keep the temperature at 60 °C for 2 h to obtain the wear-resistant and anti-aging polyurethane resin. Comparative Example 1

[0036] A wear-resistant and anti-aging polyurethane resin, by weight, comprising the following raw materials: 110 parts of polytetrahydrofuran ether glycol, 35 parts of isophorone diisocyanate, 8 parts of 1,4-butanediol, 16 parts of modified composite particles, 0.9 part of dispersant BYK-163, 120 parts of ethyl acetate, 0.4 part of BYK-333, 0.7 part of UV-531, 0.25 part of light stabilizer 944, 0.2 part of dibutyltin dilaurate.

[0037] Among them, the preparation method of the modified composite particles comprises the following steps: S1. Add 65 g of silica to 950 g of deionized water, then add 35 g of tetrabutyl titanate and 55 g of ammonia water with a mass concentration of 15%, and carry out a hydrothermal reaction at 140 °C for 6 h. After the reaction is completed, filter, wash, and dry to obtain composite particles; S2. Add 75 g of the composite particles in step S1 to 1 L of an ethanol aqueous solution (the volume ratio of ethanol to water is 3:1), then add 10 g of γ-glycidoxypropyltrimethoxysilane, and stir and react at 55 °C for 2.5 h. After the reaction is completed, filter, wash, and dry to obtain pretreated composite particles; S3. Add 75 g of the pretreated composite particles in step S2 to 1 L of toluene, then add 10 g of 4-propenoxy-2-hydroxybenzophenone and 0.6 g of triethylamine, and carry out a constant temperature reaction at 75 °C for 2.5 h under a nitrogen atmosphere. After the reaction is completed, filter, wash, and dry to obtain the modified composite particles.

[0038] A preparation method of a wear-resistant and anti-aging polyurethane resin, comprising the following steps: The polyether polyol was dehydrated at a vacuum of 600 Pa and a temperature of 105 °C for 1.5 h, and then added into a reaction kettle equipped with a stirrer, a thermometer, a condenser and a nitrogen protection device. Then, half of the ethyl acetate was added. Under nitrogen protection, the diisocyanate was added dropwise. After the dropwise addition was completed, the temperature was raised to 80 °C, and a catalyst was added, and the reaction was carried out for 2.5 h to obtain a polyurethane prepolymer; a dispersant and modified composite particles were added to the other half of the ethyl acetate, and mixed evenly to obtain a particle dispersant; the polyurethane prepolymer and the particle dispersant were mixed evenly, and then a chain extender, a leveling agent, an ultraviolet absorber and a light stabilizer 944 were added, and the reaction was carried out at 55 °C for 2.5 h to obtain the wear-resistant and anti-aging polyurethane resin.

[0039] Compared with Example 1, 3,4,5,6-tetrahydro-2-pyrimidinethiol was not introduced onto the modified composite particles in this comparative example. Comparative Example 2

[0040] A wear-resistant and anti-aging polyurethane resin, by weight, comprises the following raw materials: 110 parts of polytetrahydrofuran ether glycol, 35 parts of isophorone diisocyanate, 8 parts of 1,4-butanediol, 16 parts of modified composite particles, 0.9 part of dispersant BYK-163, 120 parts of ethyl acetate, 0.4 part of BYK-333, 0.7 part of UV-531, 0.25 part of light stabilizer 944, 0.2 part of dibutyltin dilaurate.

[0041] Among them, the preparation method of the modified composite particles comprises the following steps: S1. 65 g of silica was added to 950 g of deionized water, then 35 g of tetrabutyl titanate and 55 g of ammonia water with a mass concentration of 15% were added, and hydrothermal reaction was carried out at 140 °C for 6 h. After the reaction was completed, filtration, washing and drying were carried out to obtain composite particles; S2. 75 g of the composite particles in step S1 were added to 1 L of an ethanol aqueous solution (the volume ratio of ethanol to water is 3:1), then 10 g of γ-glycidoxypropyltrimethoxysilane was added, and stirring reaction was carried out at 55 °C for 2.5 h. After the reaction was completed, filtration, washing and drying were carried out to obtain pretreated composite particles; S3. 75 g of the pretreated composite particles in step S2 were added to 1 L of toluene, then 5 g of 3,4,5,6-tetrahydro-2-pyrimidinethiol and 0.6 g of triethylamine were added, and the reaction was carried out at a constant temperature of 75 °C for 2.5 h under a nitrogen atmosphere. After the reaction was completed, filtration, washing and drying were carried out to obtain modified composite particles.

[0042] A preparation method of a wear-resistant and anti-aging polyurethane resin comprises the following steps: The polyether polyol was dehydrated at a vacuum degree of 600 Pa and a temperature of 105 °C for 1.5 h, and then added into a reaction kettle equipped with a stirrer, a thermometer, a condenser and a nitrogen protection device. Then, half of the ethyl acetate was added. Under nitrogen protection, the diisocyanate was added dropwise. After the dropwise addition was completed, the temperature was raised to 80 °C, and a catalyst was added. The reaction was carried out for 2.5 h to obtain a polyurethane prepolymer; a dispersant and modified composite particles were added to the other half of the ethyl acetate and mixed evenly to obtain a particle dispersant; the polyurethane prepolymer and the particle dispersant were mixed evenly, and then a chain extender, a leveling agent, a UV absorber and a light stabilizer 944 were added. The reaction was carried out at 55 °C for 2.5 h to obtain the wear-resistant and anti-aging polyurethane resin.

[0043] Compared with Example 1, 4-propenyloxy-2-hydroxybenzophenone was not introduced onto the modified composite particles in this comparative example. Comparative Example 3

[0044] A wear-resistant and anti-aging polyurethane resin, by weight, comprises the following raw materials: 110 parts of polytetrahydrofuran ether glycol, 35 parts of isophorone diisocyanate, 8 parts of 1,4-butanediol, 16 parts of modified composite particles, 0.9 part of dispersant BYK-163, 120 parts of ethyl acetate, 0.4 part of BYK-333, 0.7 part of UV-531, 0.25 part of light stabilizer 944, 0.2 part of dibutyltin dilaurate.

[0045] Among them, the preparation method of the modified composite particles comprises the following steps: S1. 65 g of silica was added to 950 g of deionized water, then 35 g of tetrabutyl titanate and 55 g of ammonia water with a mass concentration of 15% were added. The hydrothermal reaction was carried out at 140 °C for 6 h. After the reaction was completed, filtration, washing and drying were carried out to obtain composite particles; S2. 75 g of the composite particles in step S1 were mixed evenly with 10 g of 4-propenyloxy-2-hydroxybenzophenone and 5 g of 3,4,5,6-tetrahydro-2-pyrimidinethiol to obtain modified composite particles.

[0046] A preparation method of a wear-resistant and anti-aging polyurethane resin comprises the following steps: The polyether polyol was dehydrated at a vacuum degree of 600 Pa and a temperature of 105 °C for 1.5 h, and then added into a reaction kettle equipped with a stirrer, a thermometer, a condenser and a nitrogen protection device. Then, half of the ethyl acetate was added. Under nitrogen protection, the diisocyanate was added dropwise. After the dropwise addition was completed, the temperature was raised to 80 °C, and a catalyst was added, and the reaction was carried out for 2.5 h to obtain a polyurethane prepolymer; a dispersant and modified composite particles were added to the other half of the ethyl acetate and mixed evenly to obtain a particle dispersant; the polyurethane prepolymer and the particle dispersant were mixed evenly, and then a chain extender, a leveling agent, an ultraviolet absorber and a light stabilizer 944 were added, and the reaction was carried out at 55 °C for 2.5 h to obtain the wear-resistant and anti-aging polyurethane resin.

[0047] Compared with Example 1, in this comparative example, 4-propenyloxy-2-hydroxybenzophenone and 3,4,5,6-tetrahydro-2-pyrimidinethiol were modified with the composite particles by physical blending.

[0048] The wear-resistant and anti-aging polyurethane resins prepared in Examples 1-3 and Comparative Examples 1-3 were added into a mold and vacuum dried into a film at 80 °C to form a coating film with a thickness of 1.5 mm, and performance tests were carried out. Among them, 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", and the tensile rate was 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 Wheel Method", and the CS-10 wheel was used for the abrasion resistance test; the ultraviolet aging resistance was tested by the ultraviolet lamp weathering artificial aging test according to the GB / T 23987-2009 standard, the irradiation wavelength was 340 nm, the temperature was 50 °C, and the time was 240 h. The tensile strength retention rate and elongation at break retention rate of the samples after aging were tested, and the test results are shown in Table 1 below.

[0049] Table 1

[0050] As can be seen from Table 1 above, the wear-resistant and anti-aging polyurethane resin prepared by the present invention has good wear resistance and excellent anti-aging performance, and at the same time has good mechanical properties, and has good application prospects.

[0051] 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 only limited to these descriptions. For those of ordinary skill in the technical field to which the present invention belongs, without departing from the concept of the present invention, several simple deductions or substitutions can still be made, which should all be regarded as belonging to the protection scope of the present invention.

[0052] Those skilled in the art can easily understand that the above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A wear-resistant and anti-aging polyurethane resin, characterized in that: 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 parts of dispersant, 100-130 parts of ethyl acetate, 0.3-0.5 parts of leveling agent, 0.5-0.8 parts of ultraviolet absorber, 0.2-0.3 parts of light stabilizer 944, and 0.15-0.25 parts of catalyst.

2. The wear-resistant and anti-aging polyurethane resin according to claim 1, characterized in that: The raw materials are as follows, measured by weight: 110-120 parts of polyether polyol, 32-37 parts of diisocyanate, 6-8 parts of chain extender, 16-18 parts of modified composite particles, 0.8-1 parts of dispersant, 110-130 parts of ethyl acetate, 0.4-0.5 parts of leveling agent, 0.5-0.7 parts of ultraviolet absorber and 0.15-0.2 parts of catalyst.

3. The wear-resistant and anti-aging polyurethane resin according to claim 1, characterized in that: The polyether polyol is one or two of polypropylene glycol and polytetramethylene glycol, the diisocyanate is one or two 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.

4. The wear-resistant and anti-aging polyurethane resin according to claim 1, characterized in that: The method for preparing the modified composite particles comprises the following steps: S1, adding silicon dioxide into deionized water, and then adding tetrabutyl titanate and ammonia water, and performing a hydrothermal reaction to obtain composite particles; S2, adding the composite particles into an ethanol aqueous solution, and then adding γ-glycidyloxypropyltrimethoxysilane, stirring and reacting to obtain pretreated composite particles; S3, adding the pretreated composite particles into toluene, and then adding 4-propyleneoxy-2-hydroxybenzophenone and triethylamine, and reacting at a constant temperature under a nitrogen atmosphere to obtain organic composite particles; S4, adding the organic composite particles into acetonitrile, and then adding 3,4,5,6-tetrahydro-2-pyrimidinethiol and photoinitiator-651, and performing ultraviolet light reaction under a nitrogen atmosphere to obtain modified composite particles.

5. The wear-resistant and anti-aging polyurethane resin according to claim 4, 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 5-7h.

6. The wear-resistant and anti-aging polyurethane resin according to claim 4, 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 reaction time is 2-3 h.

7. The wear-resistant and anti-aging polyurethane resin according to claim 4, 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, the temperature of the isothermal reaction is 70-80° C., and the time is 2-3 hours.

8. The wear-resistant and anti-aging polyurethane resin according to claim 4, 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.

9. A method for preparing a wear-resistant and anti-aging polyurethane resin, for implementing the wear-resistant and anti-aging polyurethane resin according to any one of claims 1 to 8, characterized in that: The following steps are involved: The polyether polyol is dehydrated for 1-2 hours and then added to the reactor. Then half of the ethyl acetate is added. 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. Dispersant and modified composite particles are added to the other half of the ethyl acetate and mixed evenly to obtain a particle dispersant. The polyurethane prepolymer and the particle dispersant are mixed evenly, and then a chain extender, a leveling agent, an ultraviolet absorber and a light stabilizer 944 are added to carry out a heat preservation reaction to obtain the wear-resistant and anti-aging polyurethane resin.

10. The method for preparing the wear-resistant and anti-aging polyurethane resin according to claim 9, characterized in that: The dehydration treatment is carried out at a vacuum degree of 500-800Pa and a temperature of 100-110°C for 1-2h; the heating temperature is 75-85°C and the reaction time is 2-3h; the insulation reaction temperature is 50-60°C and the reaction time is 2-3h.

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