A preparation method of elastic polyurethane self-leveling floor coating

Abstract

The present invention relates to the technical field of coatings, and discloses a preparation method of an elastic polyurethane self-leveling floor coating. The elastic polyurethane self-leveling floor coating of the present invention application comprises component A and component B; by weight, the component A comprises the following raw materials: 40-50 parts of polyol, 3-5 parts of modified hyperbranched polyester, 0.5-1 parts of defoamer, 0.2-0.6 parts of leveling agent, 0.1-0.5 parts of dispersant, 15-25 parts of talcum powder, and 10-15 parts of reinforcing filler; the component B comprises the following raw materials: 15-25 parts of isocyanate curing agent; the coating improves the comprehensive performance of the coating by adding an auxiliary agent; wherein, the addition of reinforcing filler gives the coating excellent wear resistance and corrosion resistance; the addition of modified hyperbranched polyester improves the wear resistance and antistatic performance of the coating.

Description

Technical Field

[0001] The invention relates to the technical field of coatings, and in particular to a method for preparing an elastic polyurethane self-leveling floor coating. Background Art

[0002] Elastic polyurethane self-leveling coating is a two-component solvent-free polyurethane elastic system. It is an elastic self-leveling floor material carefully formulated from modified polyurethane resin, pigment, filler, additives and curing agent. It generally has the advantages of good wear resistance, environmental protection, flexibility, convenient construction, corrosion resistance, high impact resistance, non-slip and easy cleaning. Solvent-free polyurethane elastic coating is applied by spraying. The two components react quickly, solidify instantly, have a large single film thickness, high construction efficiency and good coating integrity. However, the rapid reaction causes the coating to have poor wettability on the substrate, the bonding force between the cured coating and the substrate is weak, the coating adhesion is low, and under the action of external force, it is easy to fall off and other damage phenomena, which weakens the protective ability of the coating, and reduces the tolerance to corrosive substances, which leads to the shedding and cracking of the coating. With the different actual use environments, the coating also needs to have more excellent wear resistance, corrosion resistance, antistatic and other advantages to meet a wider market demand. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a method for preparing an elastic polyurethane self-leveling floor coating.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] An elastic polyurethane self-leveling floor coating comprises a component A and a component B; the component A comprises the following raw materials by weight: 40-50 parts of polyol, 3-5 parts of modified hyperbranched polyester, 0.5-1 part of defoamer, 0.2-0.6 part of leveling agent, 0.1-0.5 part of dispersant, 15-25 parts of talc, and 10-15 parts of reinforcing filler; the component B comprises the following raw materials: 15-25 parts of isocyanate curing agent;

[0006] The preparation method of the elastic polyurethane self-leveling floor coating comprises the following steps:

[0007] Weigh the raw materials by weight, add the polyol, modified hyperbranched polyester, defoamer, leveling agent, dispersant, talcum powder and reinforcing filler into the stirrer, mix and stir for 10-20 minutes to obtain the A component mixture, then add the isocyanate curing agent in the B component and mix and stir evenly to obtain the elastic polyurethane self-leveling floor coating;

[0008] The polyol is one or more of polytetramethylene glycol, polyethylene glycol and polytetramethylene glycol;

[0009] The reinforcing filler is prepared by first using N-methylpyrrolidone as an intercalating agent to ultrasonically exfoliate molybdenum disulfide powder to obtain lamellar molybdenum disulfide, then using 3-mercaptopropionic acid to modify the surface of the nanosheet to obtain carboxylated molybdenum disulfide, and finally using the carboxyl groups on the surface of the carboxylated molybdenum disulfide to react with the hydroxyl groups in curcumin to obtain the reinforcing filler;

[0010] Specifically, the reinforcing filler is prepared by the following steps:

[0011] Step A1, adding molybdenum disulfide powder to a reactor containing N-methylpyrrolidone, ultrasonically treating for 2-3 hours to form a suspension, and then centrifuging the suspension at a speed of 1300-1700 rpm for 40-60 minutes, taking the upper suspension, freeze-drying to obtain flaky molybdenum disulfide, adding the flaky molybdenum disulfide to deionized water, ultrasonically dispersing for 30 minutes, then adding 3-mercaptopropionic acid, ultrasonically treating for 48 hours, freeze-drying for 24 hours, and then washing with ethanol and drying to obtain carboxylated molybdenum disulfide;

[0012] Step A2, dispersing carboxylated molybdenum disulfide in acetonitrile, adding curcumin and stirring to mix evenly, then raising the system temperature to 70-80° C., reflux reaction for 24 hours, and after the reaction is completed, cooling to room temperature, centrifuging, washing, and drying to obtain a reinforced filler;

[0013] Furthermore, in step A1, the mass ratio of molybdenum disulfide powder to N-methylpyrrolidone is 1:50, and the amount ratio of flaky molybdenum disulfide, deionized water and 3-mercaptopropionic acid is 1 g: 200 mL: 1.5-3.5 mL;

[0014] Furthermore, in step A2, the usage ratio of carboxylated molybdenum disulfide, acetonitrile and curcumin is 0.5-2g:100mL:3-5g.

[0015] The modified hyperbranched polyester is prepared by reacting 3,5-dihydroxybenzoic acid, 1,1,1-tri(hydroxymethyl)ethane and dicarboxylic acid to synthesize a carboxyl-terminated hyperbranched polyester, then reacting the carboxyl-terminated hyperbranched polyester with N,N-dimethylethylenediamine to synthesize an amidated hyperbranched polyester, and finally reacting the amidated hyperbranched polyester with a halogenated hydrocarbon.

[0016] Specifically, the modified hyperbranched polyester is prepared by the following steps:

[0017] Step B1, under nitrogen conditions, 0.07 mol 3,5-dihydroxybenzoic acid, 0.01 mol 1,1,1-tri(hydroxymethyl)ethane and 0.03 g p-toluenesulfonic acid were added to the reactor, and then the system temperature was raised to 140°C, refluxed for 3 hours, and then 0.14 mol 3,5-dihydroxybenzoic acid and 0.18 g p-toluenesulfonic acid were added to continue the reaction for 3 hours, and then the reaction was reduced pressure distilled at 140°C for 3 hours and water was removed. After the reaction was completed, the temperature was maintained unchanged, and 0.2-0.3 mol succinic acid and 0.35-0.45 g p-toluenesulfonic acid were added to continue the reaction for 3 hours, and then the reaction was reduced pressure distilled for 2 hours. After the reaction was completed, it was cooled to room temperature, 30 mL acetone was added and stirred for 10 minutes, and then recrystallized, filtered, and dried to obtain a carboxyl-terminated hyperbranched polyester;

[0018] Step B2, adding N,N-dimethylethylenediamine and carboxyl-terminated hyperbranched polyester into a reactor, introducing nitrogen, and raising the system temperature to 180-200° C. for condensation and reflux for 5-7 hours. After the reaction is completed, the temperature is raised to 220° C. again, and the reaction is continued for 1-2 hours. After the reaction is completed, an amidated hyperbranched polyester is obtained;

[0019] Step B3, adding the amidated hyperbranched polyester and anhydrous methanol into a reactor and mixing them evenly, then raising the system temperature to 45° C., and then slowly dropping 1-chlorobutane, controlling the dropping speed to 5 s / drop, reacting for 15-25 hours, and after the reaction is completed, washing and drying to obtain the modified hyperbranched polyester;

[0020] Furthermore, in step B2, the mass ratio of N,N-dimethylethylenediamine to the carboxyl-terminated hyperbranched polyester is 2-5 g: 0.1-0.5 g;

[0021] Furthermore, in step B3, the usage ratio of amidated hyperbranched polyester, anhydrous methanol and 1-chlorobutane is 0.1-0.5 g:100 mL:2-4 g.

[0022] Beneficial effects of the present invention:

[0023] The elastic polyurethane self-leveling floor coating applied for by the present invention improves the comprehensive performance of the coating by adding additives; among them, the addition of reinforcing fillers gives the coating excellent wear resistance and corrosion resistance; the addition of modified hyperbranched polyester improves the wear resistance and antistatic performance of the coating.

[0024] The reinforcing filler is firstly prepared by using N-methylpyrrolidone as an intercalating agent to ultrasonically exfoliate molybdenum disulfide powder to obtain lamellar molybdenum disulfide, and then modifying the surface of the nanosheet with 3-mercaptopropionic acid to obtain carboxylated molybdenum disulfide; finally, the carboxyl group on the surface of the carboxylated molybdenum disulfide is reacted with the hydroxyl group in curcumin to obtain the reinforcing filler. The addition of reinforcing fillers can improve the corrosion resistance, wear resistance and adhesion of the coating; the improvement of corrosion resistance is due to the fact that the molybdenum disulfide in the reinforcing filler has excellent chemical stability and is not easy to react with chemicals such as acids and alkalis, and is therefore not easily corroded and oxidized. At the same time, its unique lamellar structure can hinder the penetration of gas and moisture, increase the barrier properties of the coating, and thereby reduce corrosion inside the coating; in addition, the reinforcing filler can also work synergistically with talcum powder to improve the wear resistance of the coating, because the layered structure of molybdenum disulfide can form a tough lubricating film on the friction surface, effectively reducing the friction coefficient of the coating surface, reducing wear, and achieving a wear-resistant effect; the introduction of curcumin improves the adhesion of the coating, because the β-diketone group contained in curcumin has the ability to chelate metal ions, and can chelate with the metal ions contained on the cement surface to form a complex, thereby enhancing the adhesion between the coating and the cement floor.

[0025] In the modified hyperbranched polyester, 3,5-dihydroxybenzoic acid, 1,1,1-tri(hydroxymethyl)ethane and succinic acid are first used as reaction raw materials to synthesize a carboxyl-terminated hyperbranched polyester; then the carboxyl group in the carboxyl-terminated hyperbranched polyester is reacted with the amino group in N,N-dimethylethylenediamine to generate an amidated hyperbranched polyester containing an amide group and a tertiary amine group; finally, the tertiary amine group in the amidated hyperbranched polyester is reacted with 1-chlorobutane to generate a modified hyperbranched polyester. The addition of modified hyperbranched polyester can significantly improve the toughness and antistatic performance of the coating. This is because the molecular structure of the hyperbranched polyester has a compact structure similar to a sphere, a small hydrodynamic gyration radius, a high degree of branching, and less molecular chain entanglement, which is beneficial to improving the toughness of the coating; the improvement of the antistatic performance is due to the introduction of a hydrophilic amide structure in the hyperbranched polyester, which can adsorb water molecules on the surface of the coating to form a layer of water film, thereby giving the coating surface a certain antistatic effect. At the same time, the cationic quaternary ammonium salt structure introduced in the hyperbranched polyester also has a certain antistatic effect; the amide bond in the hyperbranched polyester can also form a hydrogen bond interaction with the carbamate bond in the polyurethane molecular chain, so that the two form chemical bond crosslinking and hydrogen bond interaction, thereby improving the compatibility between the two; in addition, the hydroxyl group in the hyperbranched polyester can also react with the isocyanate group in the polyurethane molecular chain to increase the crosslinking density of the coating and improve the wear resistance and corrosion resistance of the coating. DETAILED DESCRIPTION

[0026] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0027] Example 1

[0028] The reinforcing filler is prepared by the following steps:

[0029] Step A1, add 1g of molybdenum disulfide powder to a reactor containing 50g of N-methylpyrrolidone, ultrasonically treat for 2h to form a suspension, and then centrifuge the suspension at a speed of 1300rpm for 40min, take the upper suspension, freeze-dry, and obtain flaky molybdenum disulfide, add 1g of flaky molybdenum disulfide to 200mL of deionized water, ultrasonically disperse for 30min, then add 1.5mL of 3-mercaptopropionic acid, ultrasonically treat for 48h, freeze-dry for 24h, and then wash with ethanol and dry to obtain carboxylated molybdenum disulfide;

[0030] Step A2, disperse 0.5g of carboxylated molybdenum disulfide in 100mL of acetonitrile, add 3g of curcumin and stir to mix evenly, then raise the system temperature to 70°C, reflux for 24h, and after the reaction is completed, cool to room temperature, centrifuge, wash and dry to obtain a reinforced filler.

[0031] The modified hyperbranched polyester is prepared by the following steps:

[0032] Step B1, under nitrogen conditions, 0.07 mol 3,5-dihydroxybenzoic acid, 0.01 mol 1,1,1-tri(hydroxymethyl)ethane and 0.03 g p-toluenesulfonic acid were added to the reactor, and then the system temperature was raised to 140°C, refluxed for 3 hours, and then 0.14 mol 3,5-dihydroxybenzoic acid and 0.18 g p-toluenesulfonic acid were added to continue the reaction for 3 hours, and then the reaction was reduced pressure distilled at 140°C for 3 hours and water was removed. After the reaction was completed, the temperature was maintained unchanged, and 0.2 mol succinic acid and 0.35 g p-toluenesulfonic acid were added to continue the reaction for 3 hours, and then the reaction was reduced pressure distilled for 2 hours. After the reaction was completed, it was cooled to room temperature, 30 mL acetone was added and stirred for 10 minutes, and then recrystallized, filtered, and dried to obtain a carboxyl-terminated hyperbranched polyester;

[0033] Step B2, adding 2g N,N-dimethylethylenediamine and 0.1g carboxyl-terminated hyperbranched polyester into a reactor, introducing nitrogen, and raising the system temperature to 180°C for condensation and reflux for 5h. After the reaction is completed, the temperature is raised to 220°C again, and the reaction is continued for 1h. After the reaction is completed, an amidated hyperbranched polyester is obtained;

[0034] Step B3, 0.1 g of amidated hyperbranched polyester and 100 mL of anhydrous methanol were added to the reactor and mixed evenly, then the system temperature was raised to 45° C., and then 2 g of 1-chlorobutane was slowly added dropwise, the dropping speed was controlled to be 5 s / drop, and the reaction was carried out for 8 h. After the reaction was completed, the modified hyperbranched polyester was washed and dried to obtain the modified hyperbranched polyester.

[0035] Example 2

[0036] The reinforcing filler is prepared by the following steps:

[0037] Step A1, adding 1g of molybdenum disulfide powder to a reactor containing 50g of N-methylpyrrolidone, ultrasonically treating for 2.5h to form a suspension, and then centrifuging the suspension at a speed of 1500rpm for 50min, taking the upper suspension, freeze-drying to obtain flaky molybdenum disulfide, adding 1g of flaky molybdenum disulfide to 200mL of deionized water, ultrasonically dispersing for 30min, then adding 2.5mL of 3-mercaptopropionic acid, ultrasonically treating for 48h, freeze-drying for 24h, and then washing with ethanol and drying to obtain carboxylated molybdenum disulfide;

[0038] Step A2, disperse 1g of carboxylated molybdenum disulfide in 100mL of acetonitrile, add 4g of curcumin and stir to mix evenly, then raise the system temperature to 75°C, reflux for 24h, and after the reaction is completed, cool to room temperature, centrifuge, wash and dry to obtain a reinforced filler.

[0039] The modified hyperbranched polyester is prepared by the following steps:

[0040] Step B1, under nitrogen conditions, 0.07 mol 3,5-dihydroxybenzoic acid, 0.01 mol 1,1,1-tri(hydroxymethyl)ethane and 0.03 g p-toluenesulfonic acid were added to the reactor, and then the system temperature was raised to 140°C, refluxed for 3 hours, and then 0.14 mol 3,5-dihydroxybenzoic acid and 0.18 g p-toluenesulfonic acid were added to continue the reaction for 3 hours, and then the reaction was reduced pressure distilled at 140°C for 3 hours and water was removed. After the reaction was completed, the temperature was maintained unchanged, and 0.25 mol succinic acid and 0.4 g p-toluenesulfonic acid were added to continue the reaction for 3 hours, and then the reaction was reduced pressure distilled for 2 hours. After the reaction was completed, it was cooled to room temperature, 30 mL acetone was added and stirred for 10 minutes, and then recrystallized, filtered, and dried to obtain a carboxyl-terminated hyperbranched polyester;

[0041] Step B2, 3.5 g of N, N-dimethylethylenediamine and 0.3 g of carboxyl-terminated hyperbranched polyester were added to a reactor, nitrogen was introduced, and the system temperature was raised to 190° C. for condensation and reflux for 6 h. After the reaction was completed, the temperature was raised to 220° C. again, and the reaction was continued for 1.5 h. After the reaction was completed, an amidated hyperbranched polyester was obtained;

[0042] Step B3, 0.3 g of amidated hyperbranched polyester and 100 mL of anhydrous methanol were added to the reactor and mixed evenly, then the system temperature was raised to 45 ° C, and 3 g of 1-chlorobutane was slowly added dropwise, the dropping speed was controlled to 5 s / drop, and the reaction was carried out for 10 hours. After the reaction was completed, the modified hyperbranched polyester was washed and dried to obtain the modified hyperbranched polyester.

[0043] Example 3

[0044] The reinforcing filler is prepared by the following steps:

[0045] Step A1, adding 1g of molybdenum disulfide powder to a reactor containing 50g of N-methylpyrrolidone, ultrasonically treating for 3h to form a suspension, and then centrifuging the suspension at a speed of 1700rpm for 60min, taking the upper suspension, freeze-drying to obtain flaky molybdenum disulfide, adding 1g of flaky molybdenum disulfide to 200mL of deionized water, ultrasonically dispersing for 30min, then adding 3.5mL of 3-mercaptopropionic acid, ultrasonically treating for 48h, freeze-drying for 24h, and then washing with ethanol and drying to obtain carboxylated molybdenum disulfide;

[0046] Step A2, disperse 2g of carboxylated molybdenum disulfide in 100mL of acetonitrile, add 5g of curcumin and stir to mix evenly, then raise the system temperature to 80°C, reflux for 24h, and after the reaction is completed, cool to room temperature, centrifuge, wash, and dry to obtain a reinforced filler.

[0047] The modified hyperbranched polyester is prepared by the following steps:

[0048] Step B1, under nitrogen conditions, 0.07 mol 3,5-dihydroxybenzoic acid, 0.01 mol 1,1,1-tri(hydroxymethyl)ethane and 0.03 g p-toluenesulfonic acid were added to the reactor, and then the system temperature was raised to 140°C, refluxed for 3 hours, and then 0.14 mol 3,5-dihydroxybenzoic acid and 0.18 g p-toluenesulfonic acid were added to continue the reaction for 3 hours, and then the reaction was reduced pressure distilled at 140°C for 3 hours and water was removed. After the reaction was completed, the temperature was maintained unchanged, and 0.3 mol succinic acid and 0.45 g p-toluenesulfonic acid were added to continue the reaction for 3 hours, and then the reaction was reduced pressure distilled for 2 hours. After the reaction was completed, it was cooled to room temperature, 30 mL acetone was added and stirred for 10 minutes, and then recrystallized, filtered, and dried to obtain a carboxyl-terminated hyperbranched polyester;

[0049] Step B2, adding 5g of N,N-dimethylethylenediamine and 0.5g of terminal carboxyl hyperbranched polyester into a reactor, introducing nitrogen, and raising the system temperature to 200°C for condensation and reflux for 7h. After the reaction is completed, the temperature is raised to 220°C again, and the reaction is continued for 2h. After the reaction is completed, an amidated hyperbranched polyester is obtained;

[0050] Step B3, 0.5 g of amidated hyperbranched polyester and 100 mL of anhydrous methanol were added to the reactor and mixed evenly, then the system temperature was raised to 45 ° C, and 4 g of 1-chlorobutane was slowly added dropwise, the dropping speed was controlled to 5 s / drop, and the reaction was carried out for 12 hours. After the reaction was completed, the modified hyperbranched polyester was washed and dried to obtain the modified hyperbranched polyester.

[0051] Example 4

[0052] A method for preparing an elastic polyurethane self-leveling floor coating comprises a component A and a component B; the component A comprises the following raw materials in parts by weight: 40 parts of polytetramethylene ether diol (number average molecular weight Mn=1000), 3 parts of modified hyperbranched polyester prepared in Example 1, 0.5 parts of a defoamer (KSZ-108), 0.2 parts of a leveling agent (BYK346), 0.1 parts of a dispersant (BYK-2155), 15 parts of talc, and 10 parts of a reinforcing filler prepared in Example 1; the component B comprises the following raw materials: 15 parts of diphenylmethane diisocyanate; and the method specifically comprises the following steps:

[0053] Weigh the raw materials by weight, add polytetramethylene glycol, the modified hyperbranched polyester prepared in Example 1, defoamer KSZ-108, leveling agent BYK346, dispersant BYK-2155, talcum powder and the reinforcing filler prepared in Example 1 into a stirrer, mix and stir for 10 minutes to obtain a mixture of component A, then add diphenylmethane diisocyanate in component B and mix and stir evenly to obtain an elastic polyurethane self-leveling floor coating.

[0054] Example 5

[0055] A method for preparing an elastic polyurethane self-leveling floor coating comprises a component A and a component B; the component A comprises the following raw materials in parts by weight: 45 parts of polytetramethylene ether diol (number average molecular weight Mn=1000), 4 parts of modified hyperbranched polyester prepared in Example 2, 0.7 parts of a defoamer (KSZ-108), 0.4 parts of a leveling agent (BYK346), 0.3 parts of a dispersant (BYK-2155), 20 parts of talcum powder, and 12 parts of a reinforcing filler prepared in Example 1; the component B comprises the following raw materials: 20 parts of diphenylmethane diisocyanate; and specifically comprises the following steps:

[0056] Weigh the raw materials by weight, add polytetramethylene glycol, modified hyperbranched polyester prepared in Example 2, defoamer KSZ-108, leveling agent BYK346, dispersant BYK-2155, talcum powder and reinforcing filler prepared in Example 2 into a stirrer, mix and stir for 15 minutes to obtain a mixture of component A, then add diphenylmethane diisocyanate in component B and mix and stir evenly to obtain an elastic polyurethane self-leveling floor coating.

[0057] Example 6

[0058] A method for preparing an elastic polyurethane self-leveling floor coating comprises a component A and a component B; the component A comprises the following raw materials in parts by weight: 50 parts of polytetramethylene ether diol (number average molecular weight Mn=1000), 5 parts of modified hyperbranched polyester prepared in Example 3, 1 part of a defoamer (KSZ-108), 0.6 parts of a leveling agent (BYK346), 0.5 parts of a dispersant (BYK-2155), 25 parts of talc, and 15 parts of a reinforcing filler prepared in Example 3; the component B comprises the following raw materials: 25 parts of diphenylmethane diisocyanate; and the method specifically comprises the following steps:

[0059] Weigh the raw materials by weight, add polytetramethylene glycol, the modified hyperbranched polyester prepared in Example 3, defoamer KSZ-108, leveling agent BYK346, dispersant BYK-2155, talcum powder and the reinforcing filler prepared in Example 3 into a stirrer, mix and stir for 20 minutes to obtain a mixture of component A, then add diphenylmethane diisocyanate in component B and mix and stir evenly to obtain an elastic polyurethane self-leveling floor coating.

[0060] Comparative Example 1

[0061] This comparative example is a polyurethane floor coating, which differs from Example 6 in that an equal amount of molybdenum disulfide nanosheets is used to replace the reinforcing filler prepared in Example 3, and the rest are the same.

[0062] Comparative Example 2

[0063] This comparative example is a polyurethane floor coating, which differs from Example 6 in that an equal amount of polycarbonate diol is used to replace the modified hyperbranched polyester prepared in Example 3, and the rest is the same.

[0064] The polyurethane floor coatings prepared in Examples 4-6 and Comparative Examples 1-2 were mixed evenly, poured into a mold, the surface of the mixture was scraped flat with a scraper, and cured at 60° C. for 12 h to obtain a polyurethane floor coating, and then the coating was tested for performance:

[0065] Impact resistance test: Tested in accordance with GB / T 1732-2020 standard;

[0066] Corrosion resistance test: Tested in accordance with Method A of GB / T 9274 standard;

[0067] Wear resistance test: The wear resistance of polyurethane was tested according to the method of GB / T 1768 2006, with a load of 1000, a speed of 70r / min, and a wear number of 1000 times;

[0068] Antistatic performance test: Tested in accordance with GB / T 22374-2018.

[0069] The test results are shown in the following table:

[0070]

[0071] It can be seen from the above table that the elastic polyurethane self-leveling floor coating prepared by the present invention has excellent impact resistance, corrosion resistance, wear resistance and antistatic performance, and can be widely used in factories, enterprises, laboratories and the like.

[0072] The above contents are merely examples and explanations of the concept of the present invention. The technicians in this technical field may make various modifications or additions to the specific embodiments described or replace them in a similar manner. As long as they do not deviate from the scope defined by the concept of the invention, they should all fall within the protection scope of the present invention.

Claims

1. A method for preparing an elastic polyurethane self-leveling floor coating, characterized in that: It includes component A and component B; The component A comprises the following raw materials by weight: 40-50 parts of polyol, 3-5 parts of modified hyperbranched polyester, 0.5-1 parts of defoamer, 0.2-0.6 parts of leveling agent, 0.1-0.5 parts of dispersant, 15-25 parts of talc, 10-15 parts of reinforcing filler; the B component includes the following raw materials: 15-25 parts of isocyanate curing agent; The preparation method of the elastic polyurethane self-leveling floor coating comprises the following steps: Weigh the raw materials by weight, add the polyol, modified hyperbranched polyester, defoamer, leveling agent, dispersant, talcum powder and reinforcing filler into the stirrer, mix and stir for 10-20 minutes to obtain the A component mixture, then add the isocyanate curing agent in the B component and mix and stir evenly to obtain the elastic polyurethane self-leveling floor coating; The reinforcing filler is prepared by first using N-methylpyrrolidone as an intercalating agent to ultrasonically exfoliate molybdenum disulfide powder to obtain lamellar molybdenum disulfide, then using 3-mercaptopropionic acid to modify the surface of the nanosheet to obtain carboxylated molybdenum disulfide, and finally using the carboxyl groups on the surface of the carboxylated molybdenum disulfide to react with the hydroxyl groups in curcumin to obtain the reinforcing filler; The modified hyperbranched polyester is prepared by reacting 3,5-dihydroxybenzoic acid, 1,1,1-tri(hydroxymethyl)ethane and dicarboxylic acid to synthesize a carboxyl-terminated hyperbranched polyester, then reacting the carboxyl-terminated hyperbranched polyester with N,N-dimethylethylenediamine to synthesize an amidated hyperbranched polyester, and finally reacting the amidated hyperbranched polyester with a halogenated hydrocarbon to obtain the modified hyperbranched polyester.

2. The method for preparing an elastic polyurethane self-leveling floor coating according to claim 1, characterized in that: The reinforcing filler is specifically prepared by the following steps: Step A1, adding molybdenum disulfide powder to a reactor containing N-methylpyrrolidone, ultrasonically treating for 2-3 hours to form a suspension, and then centrifuging the suspension at a speed of 1300-1700 rpm for 40-60 minutes, taking the upper suspension, freeze-drying to obtain flaky molybdenum disulfide, adding the flaky molybdenum disulfide to deionized water, ultrasonically dispersing for 30 minutes, then adding 3-mercaptopropionic acid, ultrasonically treating for 48 hours, freeze-drying for 24 hours, and then washing with ethanol and drying to obtain carboxylated molybdenum disulfide; Step A2, dispersing carboxylated molybdenum disulfide in acetonitrile, adding curcumin and stirring to mix evenly, then raising the system temperature to 70-80° C., reflux reaction for 24 hours, and after the reaction is completed, cooling to room temperature, centrifuging, washing, and drying to obtain a reinforced filler.

3. The method for preparing an elastic polyurethane self-leveling floor coating according to claim 2, characterized in that: In step A1, the mass ratio of molybdenum disulfide powder to N-methylpyrrolidone is 1:50, and the amount ratio of flaky molybdenum disulfide, deionized water and 3-mercaptopropionic acid is 1 g: 200 mL: 1.5-3.5 mL.

4. The method for preparing an elastic polyurethane self-leveling floor coating according to claim 2, characterized in that: In step A2, the usage ratio of carboxylated molybdenum disulfide, acetonitrile and curcumin is 0.5-2 g:100 mL:3-5 g.

5. The method for preparing an elastic polyurethane self-leveling floor coating according to claim 1, characterized in that: The polyol is one or more of polytetramethylene glycol, polyethylene glycol and polytetramethylene glycol.

6. The method for preparing an elastic polyurethane self-leveling floor coating according to claim 1, characterized in that: The dicarboxylic acid is one of succinic acid, oxalic acid and glutaric acid.

7. The method for preparing an elastic polyurethane self-leveling floor coating according to claim 1, characterized in that: The modified hyperbranched polyester is specifically prepared by the following steps: Step B1, under nitrogen conditions, 0.07 mol 3,5-dihydroxybenzoic acid, 0.01 mol 1,1,1-tri(hydroxymethyl)ethane and 0.03 g p-toluenesulfonic acid are added to a reactor, then the system temperature is raised to 140° C., reflux reaction is carried out for 3 hours, 0.14 mol 3,5-dihydroxybenzoic acid and 0.18 g p-toluenesulfonic acid are added, and the reaction is continued for 3 hours, and then vacuum distillation is carried out at 140° C. for 3 hours and water is removed. After the reaction is completed, the temperature is maintained unchanged, and 0.2-0.3 mol succinic acid and 0.35-0.45 g p-toluenesulfonic acid are added, and the reaction is continued for 3 hours, and then vacuum distillation is carried out for 2 hours. After the reaction is completed, it is cooled to room temperature, 30 mL acetone is added, and stirred for 10 minutes, and then recrystallized, filtered, and dried to obtain a carboxyl-terminated hyperbranched polyester; Step B2, adding N,N-dimethylethylenediamine and carboxyl-terminated hyperbranched polyester into a reactor, introducing nitrogen, and raising the system temperature to 180-200° C. for condensation and reflux for 5-7 hours. After the reaction is completed, the temperature is raised to 220° C. again, and the reaction is continued for 1-2 hours. After the reaction is completed, an amidated hyperbranched polyester is obtained; Step B3, adding the amidated hyperbranched polyester and anhydrous methanol into a reactor and mixing them evenly, then raising the system temperature to 45°C, and then slowly adding 1-chlorobutane dropwise, controlling the dropping speed to 5s / drop, reacting for 15-25h, and after the reaction is completed, washing and drying to obtain the modified hyperbranched polyester.

8. The method for preparing an elastic polyurethane self-leveling floor coating according to claim 7, characterized in that: In step B2, the mass ratio of N,N-dimethylethylenediamine to the carboxyl-terminated hyperbranched polyester is 2-5 g:0.1-0.5 g.

9. The method for preparing an elastic polyurethane self-leveling floor coating according to claim 7, characterized in that: In step B3, the amount ratio of amidated hyperbranched polyester, anhydrous methanol and 1-chlorobutane is 0.1-0.5 g:100 mL:2-4 g.

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