Easy-to-apply one-component polyurethane waterproof coating and preparation method thereof

Abstract

The application discloses an easy-to-apply single-component polyurethane waterproof coating and a preparation method thereof, and belongs to the technical field of waterproof coatings. The raw materials of the easy-to-apply single-component polyurethane waterproof coating disclosed by the application include polyhydric alcohol, plasticizer, solid filler, isocyanate, catalyst and solvent; the polyhydric alcohol includes polyether dihydric alcohol and polyether trihydric alcohol; the plasticizer includes acetyl tributyl citrate; and the catalyst includes bismuth neodecanoate catalyst and dimorpholine diethyl ether catalyst. The easy-to-apply single-component polyurethane waterproof coating disclosed by the application replaces the traditional plasticizer chlorinated paraffin with acetyl tributyl citrate, and the bismuth neodecanoate catalyst and the dimorpholine diethyl ether (DMDEE) catalyst are compounded, so that the viscosity of the waterproof coating is effectively reduced, the construction is facilitated, and meanwhile, the drying speed of the waterproof coating is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of waterproof coating, in particular to an easy-to-apply one-component polyurethane waterproof coating and a preparation method thereof. BACKGROUND

[0002] Waterproof coating is a building material that is applied to the surface of a building structure to form a continuous and dense film that prevents water from penetrating or passing through. It is widely used in modern construction and is crucial for protecting building structures, preventing leakage, and extending the service life. Polymer waterproof coating combines the flexibility of polymers with the strength of inorganic materials and is widely used in waterproofing projects for buildings and infrastructure. Polyurethane (PU) is used in polymer waterproof coating, which can significantly improve the elasticity, weather resistance and long-term waterproof performance of the coating through chemical modification or physical blending. Compared with two-component polyurethane waterproof coating, one-component polyurethane waterproof coating does not require mixing, avoiding errors in proportioning, and is particularly suitable for home and small-scale projects. It can be directly applied in high-humidity environments (RH ≤ 95%), and has obvious advantages in basement, tunnel and other scenarios.

[0003] One-component polyurethane waterproof coating is a reactive polymer waterproof material formed by the reaction of polyol and isocyanate to produce a prepolymer containing urethane groups, and fillers and various functional additives in a reaction kettle. Before curing and forming, one-component polyurethane waterproof coating is a viscous liquid. When applied, it absorbs moisture from the air, and the isocyanate end groups in the prepolymer react with water to increase the molecular chain length, thereby crosslinking and curing the coating. One-component polyurethane waterproof coating is a high-molecular reactive coating. Due to the high viscosity of conventional one-component polyurethane waterproof coating, it is not suitable for roller coating. In order to facilitate construction, construction personnel often add diluents. However, due to the uneven quality of commercially available diluents, it can cause the one-component polyurethane waterproof coating to deteriorate, reduce waterproof performance, or even fail to cure and form a film, losing its waterproof function and seriously affecting the waterproof quality. SUMMARY

[0004] The present application aims to provide an easy-to-apply one-component polyurethane waterproof coating with low viscosity and convenient construction. The present application also aims to provide a preparation method for an easy-to-apply one-component polyurethane waterproof coating with low viscosity and convenient construction.

[0005] The present application discloses an easy-to-apply one-component polyurethane waterproof coating. The raw materials of the easy-to-apply one-component polyurethane waterproof coating include polyol, plasticizer, solid filler, isocyanate, catalyst, and solvent. The polyol includes polyether diol and polyether triol. The plasticizer includes acetyl tributyl citrate. The catalyst includes bismuth neodecanoate catalyst and dimorpholine diethyl ether catalyst (DMDEE).

[0006] The low-viscosity plasticizer acetyl tributyl citrate is used in the raw material formula, which greatly reduces the interaction between the polyurethane resin molecules in the waterproof coating and improves the curing speed of the waterproof coating. However, the addition of low-viscosity acetyl tributyl citrate alone can lead to a decrease in the mechanical properties of the waterproof coating, so an organic amine catalyst dimorpholine diethyl ether catalyst (DMDEE) needs to be added to the formula. The organic amine catalyst causes the isocyanate groups at the end of the prepolymer to undergo branching reactions during the curing process of the polyurethane, increasing the proportion of reticular cross-linked structures during the curing process of the coating film, thereby improving the mechanical properties of the coating film. The curing speed of the coating film is also improved, achieving the effect of improving the drying speed of the waterproof coating.

[0007] Further, the raw materials of the easy-to-apply single-component polyurethane waterproof coating include the following components by weight: polyether diol 10-30 parts; polyether triol 1-10 parts; acetyl tributyl citrate 10-15 parts; solid filler 30-50 parts; isocyanate 1-10 parts; bismuth neodecanoate catalyst 0.1-1 part; dimorpholine diethyl ether catalyst 1-2 parts; solvent 5-15 parts.

[0008] Controlling the proportion of solid fillers in the formula within this range can reduce the viscosity of the waterproof coating.

[0009] Further, the raw materials of the easy-to-apply single-component polyurethane waterproof coating include the following components by weight: polyether diol 20-30 parts; polyether triol 2-8 parts; acetyl tributyl citrate 10-15 parts; solid filler 35-45 parts; isocyanate 2-6 parts; bismuth neodecanoate catalyst 0.2-0.8 parts; dimorpholine diethyl ether (DMDEE) catalyst 1-1.6 parts; solvent 5-15 parts.

[0010] Further, the solid filler includes heavy calcium carbonate and kaolin; the mesh size of the heavy calcium carbonate and the kaolin is 1100-1300.

[0011] The kaolin sheet layer has stronger hydrogen bonding with polyurethane, the rigid kaolin sheet layer provides more significant support, and the sheet layer arrangement is more compact, making it more suitable for building waterproofing.

[0012] Further, the mass ratio of the heavy calcium carbonate to the kaolin in the raw materials of the easy-to-apply single-component polyurethane waterproof coating is 2.5-3.1:1.

[0013] Further, the solvent is solvent oil.

[0014] Further, the raw materials of the easy-to-apply single-component polyurethane waterproof coating are as follows: 25wt% of polyether diol; 5wt% of polyether triol; 14wt% of acetyl tributyl citrate; 29.1wt% of heavy calcium carbonate; 10.1wt% of kaolin; 5.2wt% of isocyanate; 0.4wt% of bismuth neodecanoate catalyst; 1.4wt% of dimorpholine diethyl ether catalyst; and 9.8wt% of solvent oil.

[0015] Further, the isocyanate is toluene diisocyanate (TDI).

[0016] The application further discloses a preparation method of the easy-to-apply single-component polyurethane waterproof coating.

[0017] S1: polyol and plasticizer are placed in a reaction container, and stirring and heating are performed;

[0018] S2: when the temperature is increased to 45-55 DEG C, solid fillers are added, and stirring and heating are continuously performed;

[0019] S3: when the temperature is increased to 100-110 DEG C, dehydration treatment is performed under vacuum conditions;

[0020] S4: the temperature is increased to 65-75 DEG C, solvent and isocyanate are added, and after uniform stirring, the temperature is increased to 80-90 DEG C, and reaction is performed for 1.5-2.5 hours;

[0021] S5: the temperature is decreased to 65-75 DEG C, bismuth neodecanoate catalyst is added, and after uniform stirring, incubation reaction is performed for 0.5-1.5 hours; then the temperature is decreased to 45-55 DEG C, dimorpholine diethyl ether catalyst is added, and uniform stirring is performed;

[0022] S6: the temperature of the material liquid is kept at 45-55 DEG C, and bubble removal is performed under vacuum conditions, so that the easy-to-apply single-component polyurethane waterproof coating is obtained.

[0023] The organic amine catalyst has high activity, and strong gelation occurs in the synthesis stage of polyether polyol and isocyanate, so that the coating has high viscosity. Therefore, the organic amine catalyst cannot be added in the synthesis of the prepolymer of polyether polyol and isocyanate, and the organic metal catalyst with relatively low activity is added; and the organic amine catalyst is added after the prepolymer is synthesized and the temperature is decreased.

[0024] Further, in the step S3 and the step S6, the vacuum condition is -0.08 to -0.12 Mpa, and the dehydration treatment time is 3.5-4.5 hours.

[0025] The application discloses an easy-to-apply single-component polyurethane waterproof coating, which replaces traditional plasticizer chlorinated paraffin with acetyl tributyl citrate, and is compounded with bismuth neodecanoate catalyst and dimorpholine diethyl ether (DMDEE) catalyst, so that the viscosity of the waterproof coating is effectively reduced, and the waterproof coating is convenient to apply; meanwhile, the drying speed of the waterproof coating is improved. DETAILED DESCRIPTION

[0026] In order to make the technical scheme of the application clearer, the application will be further described in detail below in combination with specific examples.

[0027] The polyether diol used in the example and the comparative example is Wanhua Chemical C2020; the polyether triol is Wanhua Chemical F3135; the plasticizer 1 is commercially available chlorinated paraffin; the plasticizer 2 is commercially available acetyl tributyl citrate plasticizer; the solid filler is 1250-mesh heavy calcium carbonate and 1250-mesh kaolin; the isocyanate is Wanhua Chemical toluene diisocyanate (TDI); the catalyst 1 is bismuth neodecanoate of Yantai Yangguang Plastic Co., Ltd.; the catalyst 2 is Hengmei DMDEE; and the solvent oil is commercially available solvent oil S150.

[0028] Table 1 shows the specific formula table.

[0029] Raw material type Raw material Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Example 3 Example 4 Polyether diol Wanhua C2020 25 25 25 25 25 25 25 Polyether triol Wanhua F3135 5 5 5 5 5 5 5 Plasticizer 1 Chlorinated paraffin 12.9 0 0 0 0 0 0 Plasticizer 2 Acetyl tributyl citrate 0 12.9 12.9 12.9 12.9 12.9 14 Solid filler Heavy calcium carbonate 30.2 30.2 30.2 30.2 30.2 30.2 29.1 Solid filler Kaolin 10.1 10.1 10.1 10.1 10.1 10.1 10.1 Isocyanate TDI 5.2 5.2 5.2 5.2 5.2 5.2 5.2 Catalyst 1 Bismuth neodecanoate catalyst 1.8 1.8 0 0.4 0.2 0.8 0.4 Catalyst 2 DMDEE 0 0 1.8 1.4 1.6 1 1.4 Solvent Solvent oil S150 9.8 9.8 9.8 9.8 9.8 9.8 9.8 Total 100 100 100 100 100 100 100 Example 1

[0030] According to the formula shown in Table 1, the easy-to-apply single-component polyurethane waterproof coating is prepared.

[0031] S1: 25g of polyether diol, 5g of polyether triol and 12.9g of plasticizer (acetyl tributyl citrate) are added into a four-necked flask provided with a thermometer, a vacuum system and a stirring system, after the addition is completed, the stirring is started and the temperature is increased, and the rotating speed is 300 r / min.

[0032] S2: when the temperature in the four-necked flask is heated to 50 DEG C, 30.2g of solid filler heavy calcium carbonate and 10.1g of kaolin are weighed and added, and the stirring and temperature increasing are continued.

[0033] S3: when the temperature is increased to 105 DEG C, the vacuum system is started, and dehydration is carried out under the vacuum of-0.1MPa, the temperature is controlled at 105-110 DEG C, and the dehydration is carried out for 4h.

[0034] S4: the temperature is decreased to 70 DEG C, 9.8g of solvent oil and 5.2g of TDI are added, the temperature is kept and stirred for 10min, and then the temperature is increased to 85 DEG C, and the reaction is carried out at 85 DEG C for 2h.

[0035] S5: The temperature was lowered to 70°C, catalyst 1 (bismuth neodecanoate catalyst 0.4 g) was added, and after stirring for 5 min, the temperature was raised to 75°C, and reaction was carried out at 75°C for 1 h. The temperature was then lowered to 50°C, catalyst 2 (DMDEE catalyst 1.4 g) was added, and stirring was carried out for 10 min.

[0036] S6: The temperature was maintained at 50°C, and bubbles were removed under vacuum at -0.1 MPa for 20 min to obtain the finished product. Example 2

[0037] A single-component polyurethane waterproof coating of easy-to-apply type was prepared according to the formulation shown in Table 1:

[0038] S1: A four-necked flask equipped with a thermometer, a vacuum system, and a stirring system was charged with 25 g of polyether diol, 5 g of polyether triol, and 12.9 g of plasticizer (acetyl tributyl citrate), after which stirring was started and the temperature was raised, at a speed of 300 r / min.

[0039] S2: When the temperature in the four-necked flask was raised to 50°C, 30.2 g of solid filler, calcium carbonate, and 10.1 g of kaolin were weighed and added, and stirring and temperature raising were continued.

[0040] S3: When the temperature was raised to 105°C, the vacuum system was started, and dehydration was carried out under vacuum at -0.1 MPa, with the temperature being controlled at 105-110°C, for 4 h.

[0041] S4: The temperature was lowered to 70°C, 9.8 g of solvent oil and 5.2 g of TDI were added, and after stirring for 10 min at the same temperature, the temperature was raised to 85°C, and reaction was carried out at 85°C for 2 h.

[0042] S5: The temperature was lowered to 70°C, catalyst 1 (bismuth neodecanoate catalyst 0.2 g) was added, and after stirring for 5 min, the temperature was raised to 75°C, and reaction was carried out at 75°C for 1 h. The temperature was then lowered to 50°C, catalyst 2 (DMDEE catalyst 1.6 g) was added, and stirring was carried out for 10 min.

[0043] S6: The temperature was maintained at 50°C, and bubbles were removed under vacuum at -0.1 MPa for 20 min to obtain the finished product. Example 3

[0044] A single-component polyurethane waterproof coating of easy-to-apply type was prepared according to the formulation shown in Table 1:

[0045] S1: A four-necked flask equipped with a thermometer, a vacuum system, and a stirring system was charged with 25 g of polyether diol, 5 g of polyether triol, and 12.9 g of plasticizer (acetyl tributyl citrate), after which stirring was started and the temperature was raised, at a speed of 300 r / min.

[0046] S2: When the temperature in the four-necked flask is heated to 50°C, weigh and add the solid filler calcium carbonate 30.2 g, kaolin 10.1 g, continue to stir and heat.

[0047] S3: When the temperature is raised to 105°C, open the vacuum system, dehydrate under a vacuum of -0.1 MPa, control the temperature at 105-110°C, and dehydrate for 4 h.

[0048] S4: Reduce the temperature to 70°C, add solvent oil 9.8 g, TDI 5.2 g, stir at the temperature for 10 min, then raise the temperature to 85°C, and react at 85°C for 2 h.

[0049] S5: Reduce the temperature to 70°C, add catalyst 1 (bismuth neodecanoate catalyst 0.8 g), stir for 5 min, raise the temperature to 75°C, and react at 75°C for 1 h. Then reduce the temperature to 50°C, add catalyst 2 (DMDEE catalyst 1 g), and stir for 10 min.

[0050] S6: Maintain the temperature at 50°C, remove bubbles under a vacuum of -0.1 MPa for 20 min, and obtain the finished product. Example 4

[0051] Prepare the easy-to-apply one-component polyurethane waterproof coating according to the formulation shown in Table 1:

[0052] S1: In a four-necked flask equipped with a thermometer, a vacuum system, and a stirring system, add 25 g of polyether diol, 5 g of polyether triol, and 14 g of plasticizer (acetyl citric acid tributyl ester). After adding, start stirring and heat, and the rotation speed is 300 r / min.

[0053] S2: When the temperature in the four-necked flask is heated to 50°C, weigh and add the solid filler calcium carbonate 30.2 g, kaolin 10.1 g, continue to stir and heat.

[0054] S3: When the temperature is raised to 105°C, open the vacuum system, dehydrate under a vacuum of -0.1 MPa, control the temperature at 105-110°C, and dehydrate for 4 h.

[0055] S4: Reduce the temperature to 70°C, add solvent oil 9.8 g, TDI 5.2 g, stir at the temperature for 10 min, then raise the temperature to 85°C, and react at 85°C for 2 h.

[0056] S5: Reduce the temperature to 70°C, add catalyst 1 (bismuth neodecanoate catalyst 0.4 g), stir for 5 min, raise the temperature to 75°C, and react at 75°C for 1 h. Then reduce the temperature to 50°C, add catalyst 2 (DMDEE catalyst 1.4 g), and stir for 10 min.

[0057] S6: maintain the temperature at 50℃, remove the bubbles under vacuum at -0.1 MPa for 20 min, to obtain the finished product. Comparative Example 1

[0058] According to the formulation shown in Table 1, a single-component polyurethane waterproof coating was prepared:

[0059] S1: In a four-necked flask equipped with a thermometer, a vacuum system and a stirring system, 25 g of polyether diol, 5 g of polyether triol and 12.9 g of plasticizer (chlorinated paraffin) were added. After addition, the stirring was started and the temperature was raised, and the stirring speed was 300 r / min.

[0060] S2: When the temperature in the four-necked flask was heated to 50℃, 30.2 g of solid filler calcium carbonate and 10.1 g of kaolin were weighed and added, and the stirring and heating were continued.

[0061] S3: When the temperature rose to 105℃, the vacuum system was started, and the dehydration was carried out under vacuum at -0.1 MPa, with the temperature controlled at 105-110℃, and the dehydration was carried out for 4 h.

[0062] S4: The temperature was lowered to 70℃, 9.8 g of solvent oil and 5.2 g of TDI were added, and after the temperature was raised to 85℃ and stirred for 10 min, the reaction was carried out at 85℃ for 2 h.

[0063] S5: The temperature was lowered to 70℃, 1.8 g of catalyst 1 (bismuth neodecanoate catalyst) was added, and after stirring for 5 min, the temperature was raised to 75℃, and the reaction was carried out at 75℃ for 1 h.

[0064] S6: Maintain the temperature at 50℃, remove the bubbles under vacuum at -0.1 MPa for 20 min, to obtain the finished product. Comparative Example 2

[0065] According to the formulation shown in Table 1, a single-component polyurethane waterproof coating was prepared:

[0066] S1: In a four-necked flask equipped with a thermometer, a vacuum system and a stirring system, 25 g of polyether diol, 5 g of polyether triol and 12.9 g of plasticizer (chlorinated paraffin) were added. After addition, the stirring was started and the temperature was raised, and the stirring speed was 300 r / min.

[0067] S2: When the temperature in the four-necked flask was heated to 50℃, 30.2 g of solid filler calcium carbonate and 10.1 g of kaolin were weighed and added, and the stirring and heating were continued.

[0068] S3: When the temperature rose to 105℃, the vacuum system was started, and the dehydration was carried out under vacuum at -0.1 MPa, with the temperature controlled at 105-110℃, and the dehydration was carried out for 4 h.

[0069] S4: The temperature was reduced to 70°C, solvent oil 9.8 g, TDI 5.2 g was added, and after stirring for 10 min at the temperature, the temperature was increased to 85°C, and reacted at 85°C for 2 h.

[0070] S5: The temperature was reduced to 70°C, catalyst 1 (bismuth neodecanoate catalyst 1.8 g) was added, and after stirring for 5 min, the temperature was increased to 75°C, and reacted at 75°C for 1 h.

[0071] S6: The temperature was maintained at 50°C, and the bubbles were removed under a vacuum of -0.1 MPa for 20 min to obtain the finished product. Comparative Example 3

[0072] According to the formula shown in Table 1, a single-component polyurethane waterproof coating was prepared:

[0073] S1: In a four-necked flask equipped with a thermometer, a vacuum system, and a stirring system, 25 g of polyether diol, 5 g of polyether triol, and 12.9 g of plasticizer (acetyl citrate tributyl ester) were added. After addition, stirring was started and the temperature was increased at a speed of 300 r / min.

[0074] S2: When the temperature in the four-necked flask was heated to 50°C, 30.2 g of solid filler calcium carbonate and 10.1 g of kaolin were weighed and added, and stirring was continued while the temperature was increased.

[0075] S3: When the temperature increased to 105°C, the vacuum system was started, and dehydration was carried out under a vacuum of -0.1 MPa, with the temperature controlled at 105-110°C, for 4 h.

[0076] S4: The temperature was reduced to 70°C, solvent oil 9.8 g, TDI 5.2 g was added, and after stirring for 10 min at the temperature, the temperature was increased to 85°C, and reacted at 85°C for 2 h.

[0077] S5: The temperature was reduced to 70°C, catalyst 2 (DMDEE catalyst 1.8 g) was added, and after stirring for 5 min, the temperature was increased to 75°C, and reacted at 75°C for 1 h.

[0078] Stirring for 1 h.

[0079] S6: The temperature was reduced to 50°C, and the bubbles were removed under a vacuum of -0.1 MPa for 20 min to obtain the finished product.

[0080] Performance Test

[0081] The performance indicators were tested according to the standard GB / T 19250-2013 "Polyurethane Waterproof Coating", and the test conditions were standard environment, temperature: 23±2°C, relative humidity: 50±10%.

[0082] Table 2 Test Results

[0083] Standard Comparative Example 1 Comparative Example 2 Comparative Example 3 Example 1 Example 2 Example 3 Example 4 Viscosity, 25°C, mPa.s --- 7320 3570 8340 4160 3730 4050 3820 Tack-free time, h ≤12 6 6 2 4 3 5 4 Through-dry time, h ≤24 9 9 4 6 5 7 6 Tensile strength, MPa ≥2.00 2.43 1.73 2.76 2.53 2.04 2.33 2.67 Elongation at break, % ≥500 719 961 519 753 895 814 796 Tear strength, N / mm ≥15 20 17 22 21 19 21 22

[0084] As shown in Table 2, the comparative example 1 is a control group, and the rest of the examples and comparative examples are compared with it. The comparative example 2 is based on the comparative example 1, and the chlorinated paraffin is replaced by acetyl tributyl citrate plasticizer. According to the test data, after using the low viscosity acetyl tributyl citrate plasticizer, the viscosity is reduced by 3750 mpa.s, but the tensile strength of the cured coating film is reduced by 0.7 MPa, which does not meet the national standard requirements. The main reason is that acetyl tributyl citrate has strong plasticizing effect, which greatly reduces the intermolecular force of polyurethane resin, resulting in a decrease in tensile strength and an increase in softness.

[0085] The comparative example 3 is compared with the comparative example 2, and the bismuth neodecanoate catalyst is replaced by the organic amine catalyst DMDEE. When the organic amine catalyst is applied in the synthesis stage of the polyurethane prepolymer, the strong catalytic effect produces a gel effect, which leads to an increase in the viscosity of the coating and an increase in the tensile strength of the coating film and a decrease in the elongation.

[0086] The example 1 is compared with the comparative examples 2 and 3, and the bismuth neodecanoate catalyst and the organic amine catalyst are used in combination. The drying speed, viscosity and mechanical properties achieve a relatively optimal effect.

[0087] The example 2 is compared with the comparative example 3 and the example 1, and the optimal catalyst combination ratio is explored. The viscosity meets the requirements, the drying speed is between the comparative example 3 and the example 1, but the tensile strength is too low. The main reason is that the content of the catalyst 1 bismuth neodecanoate is too low, and the prepolymer reaction is not complete, resulting in low mechanical properties.

[0088] The example 3 is compared with the comparative example 2 and the example 1, and the viscosity and mechanical properties meet the requirements, but the drying speed is not as good as the example 1. The example 4 is compared with the example 1, and the amount of heavy calcium carbonate is reduced and the amount of bismuth neodecanoate catalyst is increased. The viscosity is further reduced, and the drying speed and mechanical properties are well balanced, which is the optimal example.

[0089] The above examples only express several embodiments of the present application, and the description is more specific and detailed, but it cannot be understood as a limitation on the scope of the patent of the present application. It should be noted that for ordinary skilled persons in the art, without departing from the concept of the present application, a number of modifications and improvements can be made, which are within the scope of protection of the present application. Therefore, the protection scope of the patent of the present application should be subject to the appended claims.

Claims

1. An easy-to-apply, one-component polyurethane waterproof coating, characterized in that, The raw materials of the easy-to-apply single-component polyurethane waterproof coating are: 25wt% polyether diol; 5wt% polyether triol; 14wt% tributyl acetylacetonate; 29.1wt% heavy calcium carbonate; 10.1wt% kaolin; 5.2wt% isocyanate; 0.4wt% bismuth neodecanoate catalyst; 1.4wt% dimorpholine diethyl ether catalyst; and 9.8wt% solvent oil.

2. The easy-to-apply, single-component polyurethane waterproof coating according to claim 1, characterized in that, The mesh size of the heavy calcium carbonate and the kaolin is 1100-1300.

3. The easy-to-apply, single-component polyurethane waterproof coating according to claim 1, characterized in that, The isocyanate is toluene diisocyanate.

4. A method for preparing an easy-to-apply, one-component polyurethane waterproof coating as described in any one of claims 1 to 3, characterized in that, Includes the following steps: S1: Place polyether diol, polyether triol, and acetylacetic acid tributyl ester in a reaction vessel, stir and heat. S2: When the temperature rises to 45-55℃, add heavy calcium carbonate and kaolin, stir and continue heating. S3: When the temperature rises to 100-110℃, dehydration is carried out under vacuum conditions; S4: Lower the temperature to 65-75℃, add solvent oil and isocyanate, stir evenly, then raise the temperature to 80-90℃ and react for 1.5-2.5h; S5: Lower the temperature to 65-75℃, add bismuth neodecanoate catalyst, stir evenly, and keep the reaction at this temperature for 0.5-1.5h; then lower the temperature to 45-55℃, add dimorpholine diethyl ether catalyst, and stir evenly. S6: Maintain the liquid temperature at 45-55℃, remove air bubbles under vacuum conditions, and obtain an easy-to-apply single-component polyurethane waterproof coating.

5. The method for preparing an easy-to-apply one-component polyurethane waterproof coating according to claim 4, characterized in that, In steps S3 and S6, the vacuum condition is -0.08 to -0.12 MPa; the dehydration time is 3.5 to 4.5 hours.