A kind of anti-aging polyurethane material and preparation method thereof

Abstract

The invention discloses an anti-aging polyurethane material and a preparation method thereof, and belongs to the technical field of polyurethane coatings. The invention uses a polyurethane resin, polypyrrole and maleic anhydride grafted polyethylene in a compounded form, which can form an entanglement effect through the linking of different active sites, which helps to enhance the network structure, thereby improving the impact resistance, and the amino group on the surface of the polypyrrole can form a hydrogen bond with the ester bond in the polyurethane, synergistically increasing the stability of the system. Combined with the interaction of a modified anti-aging auxiliary agent, an ultraviolet absorber and an anti-yellowing agent, the anti-aging performance of the polyurethane material can be significantly increased, thereby extending its service life, and the polyurethane material can be used as a powder coating, and an anti-aging coating is formed on the surface of the substrate by an electrostatic spraying process.

Description

Technical Field

[0001] The invention relates to the technical field of polyurethane coatings, and in particular to an aging-resistant polyurethane material and a preparation method thereof. Background Art

[0002] Polyurethane is a polymer with repeating structural units of carbamate segments made by the reaction of isocyanate and polyol. The hard segment of polyurethane has strong polarity. Through intermolecular hydrogen bonds, microphase regions are formed inside the polyurethane and dispersed in the soft segment matrix, forming physical or chemical crosslinking points, which make polyurethane have rubber-like elasticity. At the same time, the thermodynamic incompatibility caused by the polarity difference between the soft segment and the hard segment in the polyurethane molecular chain causes microphase separation. The unique molecular chain structure of polyurethane gives it excellent mechanical properties and processability, and it is widely used in light textile, leather processing, coating and other technical fields. Among them, polyurethane powder coating is an important category, with good adhesion and stability, but limited by the properties of polyurethane materials themselves, polyurethane will deteriorate after long-term ultraviolet light irradiation, such as yellowing of the surface, cracking, loss of gloss and other mechanical properties, etc., which causes a series of changes in its chemical composition and structure, seriously affecting its service life and protective performance. When polyurethane materials are used outdoors, they will be exposed to a large amount of ultraviolet rays, which will cause photodegradation of the materials. Even if they are not used outdoors, they will be affected by factors such as oxygen and accelerate degradation. And with the development of science and technology, the performance requirements for polyurethane materials are also constantly increasing. Although traditional polyurethane materials have excellent environmental performance, they also have the problem of insufficient aging resistance, and their performance may not meet the use requirements. For example, the Chinese patent application number CN202310731742.0 discloses a corrosion-resistant polyester powder coating and a preparation method. By using nanographene as a reinforcing material added to the coating, the flaky structure of the graphene material is used to block the tiny pores of the coating, thereby improving its corrosion resistance. For example, the Chinese patent application number CN202310313908.7 discloses a low-gloss polyurethane powder coating and a preparation method thereof, which is prepared by using 50-150 parts of high-hydroxyl polyester resin A, 300-500 parts of low-hydroxyl polyester resin B, 5-150 parts of gloss-adjusting resin C, 150-300 parts of caprolactam blocked isocyanate, 150-385 parts of pigments and fillers, 8-15 parts of leveling agents, 3-7 parts of benzoin and 3-7 parts of wetting promoters to obtain a polyurethane coating material that is resistant to boiling, solvents and wear. However, the polyurethane coating material prepared above still has the problem that the outdoor UV aging resistance needs to be improved. Summary of the invention

[0003] Based on this, in order to solve the technical problem that the polyurethane material prepared in the prior art has poor aging resistance, the present invention provides an aging-resistant polyurethane material and a preparation method thereof. The specific technical scheme is as follows:

[0004] An aging-resistant polyurethane material, comprising the following preparation raw materials in parts by weight:

[0005] 50 to 55 parts of polyurethane resin, 5 to 10 parts of polypyrrole, 7 to 12 parts of maleic anhydride grafted polyethylene, 3 to 5 parts of glass fiber, 1 to 15 parts of modified anti-aging additive, 1 to 5 parts of ultraviolet absorber, 1 to 2 parts of anti-yellowing agent, 1 to 3 parts of blocked polyisocyanate, 0.3 to 0.5 parts of curing accelerator, 0.1 to 0.5 parts of leveling agent, 1 to 3 parts of stabilizer, 0.1 to 0.5 parts of dispersant, 1 to 10 parts of filler;

[0006] The modified anti-aging additive is prepared from silicon dioxide, titanium dioxide and molybdenum disulfide in a mass ratio of (1-5):(1-3):(1-2).

[0007] Furthermore, the glass fiber has a diameter of 20 nm to 100 nm and a length of 5 μm to 20 μm.

[0008] Furthermore, the preparation method of the modified anti-aging additive is:

[0009] After mixing silicon dioxide, titanium dioxide and molybdenum disulfide, add 2-hydroxyethyl methacrylate and pentaerythritol triacrylate, heat to 50°C~60°C, stir at 200r / min~500r / min for 20min~30min, then add toluene diisocyanate, continue stirring for 30min~60min, and obtain a modified anti-aging additive.

[0010] Furthermore, the ultraviolet absorber is at least one of benzotriazole and N-acetylpiperazine.

[0011] Furthermore, the anti-yellowing agent is at least one of triphenyl phosphite, pentaerythritol ester, pentaerythritol dioctadecyl diphosphite and dilauryl thiodipropionate.

[0012] Furthermore, the curing accelerator is at least one of 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethylethanolamine, 2-methylimidazole and 2-ethyl-4-methylimidazole.

[0013] Furthermore, the leveling agent is at least one of acrylate homopolymer, polysiloxane, hydrogenated castor oil, and polyvinyl butyral.

[0014] Furthermore, the stabilizer is calcium stearate.

[0015] Furthermore, the dispersant is at least one of sodium lignin sulfonate, lauryl alcohol polyoxyethylene ether and cetearyl alcohol polyoxyethylene ether.

[0016] In addition, the present invention also provides a method for preparing an aging-resistant polyurethane material, the preparation method comprising the following steps:

[0017] Adding polyurethane resin, polypyrrole and maleic anhydride grafted polyethylene into a mixer, heating to 100°C to 120°C, and stirring at a speed of 200 r / min to 500 r / min for 30 min to 60 min to obtain a mixture A;

[0018] Adding glass fiber, modified anti-aging additive, ultraviolet absorber, anti-yellowing agent, dispersant and filler into the mixture A, and kneading at a speed of 1000 r / min to 2000 r / min for 40 min to 60 min to obtain a mixture B;

[0019] Adding blocked polyisocyanate, curing accelerator, leveling agent and stabilizer to the mixture B, and continuing stirring for 10 min to 20 min to obtain a mixture C;

[0020] The mixture C is fed into an extruder for melt extrusion to obtain an extruded material;

[0021] The extruded material is ground and sieved to obtain an aging-resistant polyurethane material.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] 1. The present invention uses a polyurethane resin, polypyrrole and maleic anhydride grafted polyethylene in a compounded form, which can form an entanglement effect through the linking of different active sites, which helps to strengthen the network structure and thus improve the impact resistance, and the amino groups on the surface of the polypyrrole can form covalent hydrogen bonds with the ester bonds in the polyurethane, synergistically increasing the stability of the system. Combined with the interaction of the modified anti-aging additive, the ultraviolet absorber and the anti-yellowing agent, the anti-aging performance of the polyurethane material can be significantly increased, thereby extending its service life.

[0024] 2. The modified anti-aging additive of the present invention is prepared by optimizing the proportion of silicon dioxide, titanium dioxide and molybdenum disulfide, and is grafted and modified by 2-hydroxyethyl methacrylate and pentaerythritol triacrylate, and then assisted by the surface modification effect of toluene diisocyanate, which can not only increase its compatibility and dispersibility in the system, but also improve the cross-linking grafting with the tertiary amine group of the polyurethane hard segment, reduce the loss of effective ingredients during use, and thus make the polyurethane material have more significant anti-aging performance.

[0025] 3. The polyurethane material of the present invention can be used as a powder coating to form an anti-aging coating on the surface of a substrate through an electrostatic spraying process. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and do not limit the scope of protection of the present invention.

[0027] If no specific experimental steps or conditions are specified in the examples, all the experiments were carried out according to the conventional experimental steps or conditions described in the literature in the field. The reagents or instruments used without specifying the manufacturer are all conventional reagents that can be obtained commercially.

[0028] An aging-resistant polyurethane material in one embodiment of the present invention comprises the following raw materials in parts by weight:

[0029] 50 to 55 parts of polyurethane resin, 5 to 10 parts of polypyrrole, 7 to 12 parts of maleic anhydride grafted polyethylene, 3 to 5 parts of glass fiber, 1 to 15 parts of modified anti-aging additive, 1 to 5 parts of ultraviolet absorber, 1 to 2 parts of anti-yellowing agent, 1 to 3 parts of blocked polyisocyanate, 0.3 to 0.5 parts of curing accelerator, 0.1 to 0.5 parts of leveling agent, 1 to 3 parts of stabilizer, 0.1 to 0.5 parts of dispersant, 1 to 10 parts of filler;

[0030] The modified anti-aging additive is prepared from silicon dioxide, titanium dioxide and molybdenum disulfide in a mass ratio of (1-5):(1-3):(1-2).

[0031] In one embodiment, the glass fiber has a diameter of 20 nm to 100 nm and a length of 5 μm to 20 μm.

[0032] In one embodiment, the preparation method of the modified anti-aging additive is:

[0033] After mixing silicon dioxide, titanium dioxide and molybdenum disulfide, add 2-hydroxyethyl methacrylate and pentaerythritol triacrylate, heat to 50°C~60°C, stir at 200r / min~500r / min for 20min~30min, then add toluene diisocyanate, continue stirring for 30min~60min, and obtain a modified anti-aging additive.

[0034] In one embodiment, the added amount of 2-hydroxyethyl methacrylate accounts for 5% to 10% of the mass of the modified anti-aging additive.

[0035] In one embodiment, the added amount of the pentaerythritol triacrylate accounts for 5% to 10% of the mass of the modified anti-aging additive.

[0036] In one embodiment, the added amount of the toluene diisocyanate accounts for 12% to 20% of the mass of the modified anti-aging additive.

[0037] In one embodiment, the ultraviolet absorber is at least one of benzotriazole and N-acetylpiperazine.

[0038] In one embodiment, the anti-yellowing agent is at least one of triphenyl phosphite, pentaerythritol ester, pentaerythritol dioctadecyl diphosphite and dilauryl thiodipropionate.

[0039] In one embodiment, the curing accelerator is at least one of 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethylethanolamine, 2-methylimidazole and 2-ethyl-4-methylimidazole.

[0040] In one embodiment, the leveling agent is at least one of acrylate homopolymer, polysiloxane, hydrogenated castor oil, and polyvinyl butyral.

[0041] In one embodiment, the stabilizer is calcium stearate.

[0042] In one embodiment, the dispersant is at least one of sodium lignin sulfonate, lauryl alcohol polyoxyethylene ether and cetearyl alcohol polyoxyethylene ether.

[0043] In one embodiment, the filler is at least one of barium sulfate, silicon powder, talcum powder, mica powder and quartz powder.

[0044] In addition, the present invention also provides a method for preparing an aging-resistant polyurethane material, the preparation method comprising the following steps:

[0045] Adding polyurethane resin, polypyrrole and maleic anhydride grafted polyethylene into a mixer, heating to 100°C to 120°C, and stirring at a speed of 200 r / min to 500 r / min for 30 min to 60 min to obtain a mixture A;

[0046] Adding glass fiber, modified anti-aging additive, ultraviolet absorber, anti-yellowing agent, dispersant and filler into the mixture A, and kneading at a speed of 1000 r / min to 2000 r / min for 40 min to 60 min to obtain a mixture B;

[0047] Adding blocked polyisocyanate, curing accelerator, leveling agent and stabilizer to the mixture B, and continuing stirring for 10 min to 20 min to obtain a mixture C;

[0048] The mixture C is fed into an extruder for melt extrusion to obtain an extruded material;

[0049] The extruded material is ground and sieved to obtain an aging-resistant polyurethane material.

[0050] In one embodiment, the temperature of the melt extrusion zone I is 105°C to 125°C, and the temperature of the extruder zone II is 95°C to 115°C.

[0051] The polyurethane material prepared by the above scheme can form a coating with remarkable aging resistance.

[0052] The embodiments of the present invention will be described in detail below with reference to specific examples. Example 1

[0053] A method for preparing an aging-resistant polyurethane material, the preparation method comprising the following steps:

[0054] After mixing silicon dioxide, titanium dioxide and molybdenum disulfide in a mass ratio of 5:3:2, 2-hydroxyethyl methacrylate accounting for 5% of the mass of the modified anti-aging additive and pentaerythritol triacrylate accounting for 8% of the mass of the modified anti-aging additive are added, heated to 60°C, stirred at 250r / min for 25min, and then toluene diisocyanate accounting for 12% of the mass of the modified anti-aging additive is added, and stirring is continued for 35min to obtain a modified anti-aging additive for standby use;

[0055] 52 parts of polyurethane resin, 8 parts of polypyrrole and 10 parts of maleic anhydride grafted polyethylene were added into a mixer by weight, heated to 100° C., and stirred at a speed of 200 r / min for 30 minutes to obtain a mixture A;

[0056] Add 3 parts of glass fiber, 10 parts of modified anti-aging additive, 3 parts of N-acetylpiperazine, 2 parts of pentaerythritol ester, 0.3 parts of lauryl alcohol polyoxyethylene ether and 9 parts of barium sulfate to the mixture A by weight, and mix at a speed of 1000 r / min for 40 minutes to obtain a mixture B;

[0057] Add 2 parts of blocked polyisocyanate, 0.5 parts of N,N-dimethylethanolamine, 0.5 parts of polysiloxane and 2 parts of calcium stearate to the mixture B by weight, and continue stirring for 10 minutes to obtain a mixture C;

[0058] The mixture C is sent to an extruder for melt extrusion with the temperature of zone I being 120° C. and the temperature of zone II being 110° C. to obtain an extruded material;

[0059] The extruded material is ground and sieved to obtain an aging-resistant polyurethane material. Example 2

[0060] A method for preparing an aging-resistant polyurethane material, the preparation method comprising the following steps:

[0061] After mixing silicon dioxide, titanium dioxide and molybdenum disulfide in a mass ratio of 5:3:2, 2-hydroxyethyl methacrylate accounting for 8% of the mass of the modified anti-aging additive and pentaerythritol triacrylate accounting for 6% of the mass of the modified anti-aging additive are added, heating to 60°C, stirring at 200r / min for 30min, then adding toluene diisocyanate accounting for 15% of the mass of the modified anti-aging additive, and continuing to stir for 40min to obtain a modified anti-aging additive for standby use;

[0062] 54 parts of polyurethane resin, 9 parts of polypyrrole and 9 parts of maleic anhydride grafted polyethylene were added into a mixer by weight, heated to 120° C., and stirred at a speed of 200 r / min for 30 minutes to obtain a mixture A;

[0063] Add 5 parts of glass fiber, 10 parts of modified anti-aging additive, 5 parts of N-acetylpiperazine, 2 parts of triphenyl phosphite, 0.5 parts of lauryl alcohol polyoxyethylene ether and 10 parts of barium sulfate to the mixture A by weight, and mix at a speed of 1000 r / min for 40 minutes to obtain a mixture B;

[0064] Add 3 parts of blocked polyisocyanate, 0.5 parts of N,N-dimethylethanolamine, 0.3 parts of polysiloxane and 3 parts of calcium stearate to the mixture B by weight, and continue stirring for 15 minutes to obtain a mixture C;

[0065] The mixture C is sent to an extruder for melt extrusion with the temperature of zone I being 120° C. and the temperature of zone II being 110° C. to obtain an extruded material;

[0066] The extruded material is ground and sieved to obtain an aging-resistant polyurethane material. Example 3

[0067] A method for preparing an aging-resistant polyurethane material, the preparation method comprising the following steps:

[0068] After mixing silicon dioxide, titanium dioxide and molybdenum disulfide in a mass ratio of 4:3:1, add 7% of the mass of the modified anti-aging additive, 2-hydroxyethyl methacrylate and 8% of the mass of the modified anti-aging additive, heat to 55°C, stir at 200r / min for 25min, then add 15% of the mass of the modified anti-aging additive, stir for 30min, and obtain a modified anti-aging additive for standby use;

[0069] 55 parts of polyurethane resin, 10 parts of polypyrrole and 10 parts of maleic anhydride grafted polyethylene were added into a mixer by weight, heated to 110° C., and stirred at a speed of 200 r / min for 30 minutes to obtain a mixture A;

[0070] Add 4 parts of glass fiber, 10 parts of modified anti-aging additive, 4 parts of N-acetylpiperazine, 2 parts of triphenyl phosphite, 0.5 parts of lauryl alcohol polyoxyethylene ether and 9 parts of barium sulfate to the mixture A by weight, and mix at a speed of 1000 r / min for 40 minutes to obtain a mixture B;

[0071] Add 3 parts of blocked polyisocyanate, 0.5 parts of N,N-dimethylethanolamine, 0.3 parts of polysiloxane and 3 parts of calcium stearate to the mixture B by weight, and continue stirring for 15 minutes to obtain a mixture C;

[0072] The mixture C is sent to an extruder for melt extrusion with the temperature of zone I being 120° C. and the temperature of zone II being 110° C. to obtain an extruded material;

[0073] The extruded material is ground and sieved to obtain an aging-resistant polyurethane material.

[0074] Comparative Example 1:

[0075] Compared with Example 3, Comparative Example 1 does not add polypyrrole, and the other parts are the same as Example 3.

[0076] Comparative Example 2:

[0077] Compared with Example 3, Comparative Example 2 does not add maleic anhydride grafted polyethylene, and the rest is the same as Example 3.

[0078] Comparative Example 3:

[0079] Comparative Example 3 Compared with Example 3, the preparation method of the modified anti-aging additive in Comparative Example 3 is as follows, and the rest is the same as Example 3;

[0080] Add silica to 7% of 2-hydroxyethyl methacrylate and 6% of pentaerythritol triacrylate of the modified anti-aging additive, heat to 55°C, stir at 200r / min for 25min, then add 15% of toluene diisocyanate of the modified anti-aging additive, continue stirring for 30min to obtain the modified anti-aging additive.

[0081] Comparative Example 4:

[0082] Comparative Example 4 Compared with Example 3, the preparation method of the modified anti-aging additive in Comparative Example 4 is as follows, and the rest is the same as Example 3;

[0083] Titanium dioxide was added to 7% of 2-hydroxyethyl methacrylate and 6% of pentaerythritol triacrylate of the modified anti-aging agent, heated to 55°C, stirred at 200 r / min for 25 minutes, and then 15% of toluene diisocyanate of the modified anti-aging agent was added, and stirring was continued for 30 minutes to obtain a modified anti-aging agent.

[0084] Comparative Example 5:

[0085] Comparative Example 5 Compared with Example 3, the preparation method of the modified anti-aging additive in Comparative Example 5 is as follows, and the rest is the same as Example 3;

[0086] Molybdenum disulfide was added to 7% of 2-hydroxyethyl methacrylate and 6% of pentaerythritol triacrylate of the modified anti-aging agent, heated to 55°C, stirred at 200 r / min for 25 min, and then 15% of toluene diisocyanate of the modified anti-aging agent was added, and stirring was continued for 30 min to obtain a modified anti-aging agent.

[0087] Comparative Example 6:

[0088] Comparative Example 6 Compared with Example 3, the preparation method of the modified anti-aging additive in Comparative Example 6 is as follows, and the rest is the same as Example 3;

[0089] After mixing silicon dioxide, titanium dioxide and molybdenum disulfide in a mass ratio of 3:1:1, add 7% of 2-hydroxyethyl methacrylate by mass of the modified anti-aging additive, stir at a speed of 200r / min for 25min, then add 15% of toluene diisocyanate by mass of the modified anti-aging additive, and continue stirring for 30min to obtain a modified anti-aging additive.

[0090] Comparative Example 7:

[0091] Comparative Example 7 Compared with Example 3, the preparation method of the modified anti-aging additive in Comparative Example 7 is as follows, and the rest is the same as Example 3;

[0092] After mixing silicon dioxide, titanium dioxide and molybdenum disulfide in a mass ratio of 3:1:1, add pentaerythritol triacrylate accounting for 6% of the mass of the modified anti-aging additive, heat to 55°C, stir at 200r / min for 25min, then add toluene diisocyanate accounting for 15% of the mass of the modified anti-aging additive, continue stirring for 30min, and obtain a modified anti-aging additive.

[0093] Comparative Example 8:

[0094] Comparative Example 8 Compared with Example 3, the preparation method of the modified anti-aging additive in Comparative Example 8 is as follows, and the rest is the same as Example 3;

[0095] After mixing silicon dioxide, titanium dioxide and molybdenum disulfide in a mass ratio of 3:1:1, 7% of the mass of the modified anti-aging additive, 2-hydroxyethyl methacrylate and 6% of the mass of the modified anti-aging additive were added, heated to 55°C, and stirred at a speed of 200 r / min for 35 minutes to obtain a modified anti-aging additive.

[0096] Comparative Example 9:

[0097] Compared with Example 3, Comparative Example 9 does not add modified anti-aging additive, and the rest is the same as Example 3.

[0098] Comparative Example 10:

[0099] Compared with Example 3, Comparative Example 10 does not add an ultraviolet absorber, and the rest is the same as Example 3.

[0100] Comparative Example 11:

[0101] Compared with Example 3, Comparative Example 11 does not add an anti-yellowing agent, and the rest is the same as Example 3.

[0102] The polyurethane material samples prepared in Examples 1 to 3 and the polyurethane material comparison samples prepared in Comparative Examples 1 to 11 are used as powder coatings. The specific application method is: the polyurethane material samples and the polyurethane comparison samples are used to electrostatically spray the surface of the metal plate, respectively. The specific electrostatic spraying process is: first, the surface of the metal plate to be sprayed is cleaned, and then it is heated to 200°C by a high-frequency induction coil and then enters the powder spraying workshop. The powder supply pressure is 0.06MPa, the spraying voltage is 65kV, the powder spraying amount is 150g / min, and the spraying distance is 200mm. After completing the electrostatic spraying process, a coating with a thickness of 200 microns is formed.

[0103] Among them, the appearance is recorded by visual inspection; the hardness refers to GB / T6739; the aging resistance test is: placed in a UV aging weathering box, equipped with UVA ultraviolet lamp, temperature 25°C, relative humidity 50±5%, and observe and photograph the coating performance every 48 hours; the impact resistance refers to GB / T1732; the results are shown in Table 1.

[0104] Table 1: Performance test results

[0105]

[0106] From the data analysis of Table 1, it can be seen that the polyurethane material prepared by the present invention has excellent aging resistance, and can form a coating appearance with a smooth surface and no pinholes, and the hardness and impact resistance can meet the use requirements. Specifically, compared with Example 3, no polypyrrole was added in Comparative Example 1, and the hardness and impact resistance were significantly worse than those in Example 3, indicating that the addition of polypyrrole in the present invention can increase the cross-linking structure in the system, which has a positive effect on the hardness and impact resistance; Comparative Example 2 did not add maleic anhydride grafted polyethylene, but the hardness and impact resistance were also significantly worse than those in Example 3, indicating that the addition of maleic anhydride grafted polyethylene can increase the entanglement of the system, help to enhance the network structure, and thus improve the impact resistance; Comparative Examples 3 to 5 have different preparation methods for the modified anti-aging additives, but The aging resistance and impact resistance are significantly reduced, indicating that the use of silicon dioxide, titanium dioxide and molybdenum disulfide after compounding can play a synergistic role, not only can significantly improve the aging resistance, but also promote the impact resistance of the coating surface; in Comparative Example 6, pentaerythritol triacrylate is not added, the aging resistance is reduced and the impact resistance is also worse than that of Example 3; in Comparative Example 7, 2-hydroxyethyl methacrylate is not added, the aging resistance is reduced and the impact resistance is also worse than that of Example 3, indicating that the use of 2-hydroxyethyl methacrylate and pentaerythritol The combined effect of triacrylate has a positive effect on the performance of polyurethane materials; in Comparative Example 8, no toluene diisocyanate is added, the dispersion performance of the modified anti-aging additive is poor, the appearance quality is poor, a small amount of pinholes appear, and the aging resistance and impact resistance are significantly worse than those in Example 3, indicating that toluene diisocyanate can act on the surfaces of silicon dioxide, titanium dioxide and molybdenum disulfide, promote compatibility with polyurethane resin, and improve the cross-linking and grafting of tertiary amine groups with polyurethane hard segments, thereby having a positive effect on aging resistance and impact resistance; in Comparative Example 9, no modified anti-aging additive is added, but the surface hardness, aging resistance and impact resistance are significantly worse than those in Example 3, indicating that adding modified anti-aging additives helps to improve the hardness, aging resistance and impact resistance of the coating surface formed by the polyurethane material; in Comparative Example 10, no ultraviolet absorber is added, but the aging resistance is significantly worse than that in Example 3, indicating that adding ultraviolet absorber can play a role in synergistically increasing the aging resistance in the system; in Comparative Example 11, no anti-yellowing agent is added, but the aging resistance is significantly reduced, indicating that adding anti-yellowing agent can also play a role in synergistically increasing the aging resistance. Therefore, the present invention can obtain a product with excellent surface quality, significant aging resistance and impact resistance through the optimization of ingredients and processes, which can meet market application needs.

[0107] The above-mentioned embodiments only express several implementation methods of the present invention, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. An aging-resistant polyurethane material, characterized in that: The anti-aging polyurethane material comprises the following raw materials by weight: 50 to 55 parts of polyurethane resin, 5 to 10 parts of polypyrrole, 7 to 12 parts of maleic anhydride grafted polyethylene, 3 to 5 parts of glass fiber, 1 to 15 parts of modified anti-aging additive, 1 to 5 parts of ultraviolet absorber, 1 to 2 parts of anti-yellowing agent, 1 to 3 parts of blocked polyisocyanate, 0.3 to 0.5 parts of curing accelerator, 0.1 to 0.5 parts of leveling agent, 1 to 3 parts of stabilizer, 0.1 to 0.5 parts of dispersant, 1 to 10 parts of filler; The modified anti-aging additive is prepared from silicon dioxide, titanium dioxide and molybdenum disulfide in a mass ratio of (1-5):(1-3):(1-2); The preparation method of the modified anti-aging additive is: After mixing silicon dioxide, titanium dioxide and molybdenum disulfide, add 2-hydroxyethyl methacrylate and pentaerythritol triacrylate, heat to 50°C~60°C, stir at 200r / min~500r / min for 20min~30min, then add toluene diisocyanate, continue stirring for 30min~60min to obtain a modified anti-aging additive.

2. The aging-resistant polyurethane material according to claim 1, characterized in that: The glass fiber has a diameter of 20 nm to 100 nm and a length of 5 μm to 20 μm.

3. The aging-resistant polyurethane material according to claim 1, characterized in that: The ultraviolet absorber is at least one of benzotriazole and N-acetylpiperazine.

4. The aging-resistant polyurethane material according to claim 1, characterized in that: The anti-yellowing agent is at least one of triphenyl phosphite, pentaerythritol ester, pentaerythritol dioctadecyl diphosphite and dilauryl thiodipropionate.

5. The aging-resistant polyurethane material according to claim 1, characterized in that: The curing accelerator is at least one of 2,4,6-tris(dimethylaminomethyl)phenol, N,N-dimethylethanolamine, 2-methylimidazole and 2-ethyl-4-methylimidazole.

6. The aging-resistant polyurethane material according to claim 1, characterized in that: The leveling agent is at least one of acrylate homopolymer, polysiloxane, hydrogenated castor oil and polyvinyl butyral.

7. The aging-resistant polyurethane material according to claim 1, characterized in that: The stabilizer is calcium stearate.

8. The aging-resistant polyurethane material according to claim 1, characterized in that: The dispersant is at least one of sodium lignin sulfonate, lauryl alcohol polyoxyethylene ether and cetearyl alcohol polyoxyethylene ether.

9. A method for preparing an aging-resistant polyurethane material, characterized in that: The preparation method is used to prepare the aging-resistant polyurethane material according to any one of claims 1 to 8, and the preparation method comprises the following steps: Adding polyurethane resin, polypyrrole and maleic anhydride grafted polyethylene into a mixer, heating to 100°C to 120°C, and stirring at a speed of 200 r / min to 500 r / min for 30 min to 60 min to obtain a mixture A; Adding glass fiber, modified anti-aging additive, ultraviolet absorber, anti-yellowing agent, dispersant and filler into the mixture A, and kneading at a speed of 1000 r / min to 2000 r / min for 40 min to 60 min to obtain a mixture B; Adding blocked polyisocyanate, curing accelerator, leveling agent and stabilizer to the mixture B, and continuing stirring for 10 min to 20 min to obtain a mixture C; The mixture C is fed into an extruder for melt extrusion to obtain an extruded material; The extruded material is ground and sieved to obtain an aging-resistant polyurethane material.

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