Single-component fluorine-free high-hydrophobicity polyurethane waterproof coating and preparation method thereof

Abstract

The invention belongs to the technical field of polyurethane waterproof coatings, and particularly relates to a single-component fluorine-free high-hydrophobicity polyurethane waterproof coating and a preparation method thereof, and the single-component fluorine-free high-hydrophobicity polyurethane waterproof coating comprises the following raw materials by weight: 60-80 parts of composite polyether polyol; 20 to 40 parts of silane modified polyether polyol; 11 to 17 parts of diisocyanate; 2-5 parts of a chain extender; 50 to 70 parts of a plasticizer; 50 to 70 parts of filler; 0.15 to 0.2 part of a catalyst; and 3-5 parts of an auxiliary agent. A polyoxypentene ether chain segment, a castor oil-based structure and a silane group are introduced into the molecular structure of the waterproof coating through chemical modification, the intrinsic hydrophobic and mechanical properties of the material are improved, the migration defect caused by addition of a hydrophobic agent and silicone oil in a traditional preparation method is overcome, and the invention further provides a preparation method of the waterproof coating.

Description

Technical Field

[0001] The present invention belongs to the technical field of polyurethane waterproof coatings, and in particular relates to a single-component fluorine-free highly hydrophobic polyurethane waterproof coating and a preparation method thereof. Background Art

[0002] Polyurethane waterproof coatings are a key area of ​​application for polyurethane synthetic materials. Polyurethane coating films offer significant advantages: excellent elasticity and extensibility, strong adhesion, and low volume shrinkage. The resulting waterproof layer is seamless, highly adaptable to substrate cracks and expansion and contraction, and easy to apply and maintain. Based on their composition, they can be categorized as either one-component or two-component. Compared to two-component polyurethane waterproof coatings, one-component coatings are ready for on-site use, are easy to apply, and require no large mixing equipment. They also have low substrate moisture requirements and can be applied in high humidity conditions.

[0003] Chinese invention patent publication number CN116970339B discloses a one-component, self-cleaning polyurethane waterproof coating and its preparation method. The coating enhances its hydrophobicity by introducing benzene rings and fluorine-silicon segments into its molecular structure. However, the fluorine element in the raw materials may be released into the environment during use, causing environmental pollution. Chinese invention patent publication number CN116875174A discloses a silane-modified polyurethane waterproof coating and its preparation method. While these coatings improve the tensile strength, bond strength, and waterproofing properties of the polyurethane waterproof coating to some extent, they suffer from low hardness and poor friction resistance, making them ineffective in high-stress environments such as parking lots and pedestrian roofs. The waterproof layer is easily damaged within a short period of time, preventing long-term waterproofing. Chinese invention patent application publication number CN119639319A discloses a silane-modified polyether waterproof coating and a preparation method for improving its hydrophobicity. By silane-capping the polyether molecular structure and introducing siloxane segments, the hydrophobicity of the material is improved. However, if it is exposed to water or high humidity for a long time, the alkoxy groups will be converted into hydroxyl groups, reducing the hydrophobicity of the polyether and affecting the use effect of the waterproof coating. Chinese invention patent authorization announcement number CN111518255B discloses a transparent hydrophobic silicon-fluorine-containing polyurethane coating and a preparation method thereof. Silicon and fluorine elements are introduced into polyurethane through free radical polymerization to improve the hydrophobicity of the coating film. However, the actual water contact angle of the coating surface obtained is only 103°, and the hydrophobic effect is not ideal. Chinese invention patent application publication number CN115651524A discloses a high-strength self-cleaning polyurethane waterproof coating and a preparation method thereof. The hydrophobicity of the material is achieved by introducing homemade polyfluorosilicone@hydroxyl-containing nanofiller, but its compatibility with other raw materials in the formula components is poor and it is easy to cause precipitation. Chinese invention patent application publication number CN112940598A discloses a super-hydrophobic water-based polyurethane waterproof coating composed of the following ingredients: water, a pH adjuster, hydroxyethyl cellulose, a polyurethane emulsion, a preservative, a wetting and dispersing agent, a defoamer, titanium dioxide, modified barium sulfate, an antifreeze agent, and a thickener. By screening the polyurethane emulsion and additives and studying their dosage ratios, a super-absorbent water-based polyurethane waterproof coating was developed. The 30-day water absorption rate was reduced to 3.4%, resulting in poor waterproofing. Chinese invention patent application publication number CN113603881A discloses a fluorinated polytetrahydrofuran diol, its preparation method, a fluorinated polyurethane waterproof coating, and its composition, preparation method, and application. While the use of fluorinated polytetrahydrofuran diol improves the material's hydrophobicity, its preparation process requires the use of liquid nitrogen and acetone, a precursor organic solvent. Furthermore, the resulting waterproof coating has a contact angle of 110°, leaving room for improvement in its hydrophobicity. Summary of the Invention

[0004] In order to solve the above technical problems, the present invention provides a one-component fluorine-free highly hydrophobic polyurethane waterproof coating. By chemically modifying the molecular structure of the waterproof coating, polyoxypentylene ether segments, castor oil-based structures, and silane groups are introduced to improve the intrinsic hydrophobicity and mechanical properties of the material, and solve the migration problem caused by the addition of hydrophobic agents and silicone oils in traditional preparation methods. The present invention also provides a preparation method thereof.

[0005] The one-component fluorine-free highly hydrophobic polyurethane waterproof coating of the present invention is composed of the following raw materials in parts by weight: Composite polyether polyol: 60-80 parts; Silane-modified polyether polyol: 20-40 parts; Diisocyanate: 11-17 parts; Chain extender: 2~5 parts; Plasticizer: 50~70 parts; Filler: 50~70 parts; Catalyst: 0.15~0.2 parts; Additives: 3~5 parts; Composite polyether polyol is obtained by polymerizing propylene oxide and 1,2-epoxyhexane with castor oil and pentaerythritol polyether polyol as initiators under the action of DMC catalyst. 1,2-epoxyhexane accounts for 50%-70% of the total mass of castor oil, pentaerythritol polyether polyol, propylene oxide and 1,2-epoxyhexane, and has a number average molecular weight of 5000g•mol -1 , functionality is 3; among them, castor oil functionality is 2.7, hydroxyl value is 162mgKOH / g; pentaerythritol polyether polyol is obtained by polymerizing propylene oxide with pentaerythritol as the initiator under the action of KOH catalyst, with a number average molecular weight of 800g•mol -1 , functionality is 4; The preparation steps of silane-modified polyether polyol are as follows: sorbitol polyether polyol and oleic acid are subjected to esterification reaction, and after the reaction, alkyl hydrogen silane is added for addition reaction to obtain the obtained product. Sorbitol polyether polyol is obtained by polymerization of propylene oxide with sorbitol as the initiator under the action of KOH catalyst, and has a number average molecular weight of 1500 g·mol -1 , functionality is 6; the alkyl hydrogen silane is one of diethylmethyl hydrogen silane and triethyl hydrogen silane.

[0006] Preferably, the preparation steps of the silane-modified polyether polyol are as follows: sorbitol polyether polyol, oleic acid and p-toluenesulfonic acid are added to a reactor with a condenser, nitrogen is introduced for replacement three times, the temperature is raised to 150-170°C, stirred for reaction, by-products are continuously separated and evaporated through a distillation column during the reaction, and the reaction is carried out for 6-8 hours; the temperature is lowered to 80-100°C, alkyl hydrogen silane and chloroplatinic acid catalyst are added, the reaction is carried out for 4-6 hours, and the infrared test wave number is 1640 cm-1 After the carbon-carbon double bond peak disappears, the addition reaction is completed to obtain the silane-modified polyether polyol; the molar ratio of sorbitol polyether polyol, oleic acid and alkyl hydrogen silane is 1:4.08:4; the amount of chloroplatinic acid catalyst is 70-100 ppm of the total amount of sorbitol polyether polyol, oleic acid and alkyl hydrogen silane.

[0007] Preferably, the diisocyanate is one of hexamethylene diisocyanate and diphenylmethane diisocyanate.

[0008] Preferably, the filler is one or more of kaolin, fumed silica or calcium carbonate.

[0009] Preferably, the chain extender is bisphenol A dihydroxypropyl ether, with the molecular formula C 21 H 28 O4, CAS number is 116-37-0, the benzene ring structure in the molecule can improve the hydrophobicity and adhesion of the material.

[0010] Preferably, the plasticizer is one of chlorinated paraffin, epoxidized soybean oil, and triethyl phosphate.

[0011] Preferably, the catalyst is dibutyltin dilaurate.

[0012] Preferably, the auxiliary agent is an organosilicon defoamer.

[0013] The preparation method of the one-component fluorine-free highly hydrophobic polyurethane waterproof coating of the present invention comprises the following steps: S1. Add the composite polyether polyol, silane-modified polyether polyol, filler, and plasticizer into a reaction kettle, heat to 100-110°C, and vacuum dehydrate until the moisture content is below 0.04%; S2: Cool down to 60~70℃, add diisocyanate, react at 70~80℃ for 3~4h, then add chain extender and continue to react for 2~3h; S3: After the -NCO% reaches 0.93%-1.15%, cool to 20~40℃, add catalyst and additives, and stir evenly to obtain a one-component fluorine-free highly hydrophobic polyurethane waterproof coating.

[0014] Compared with the prior art, the present invention has the following beneficial effects: 1. The composite polyether polyol of the present invention, by introducing castor oil groups and epoxidized hexyl ether chain segments into the polyether polyol structure, can play a hydrophobic and internal plasticizing role, thereby improving the intrinsic waterproof performance. At the same time, by designing the functionality of the composite polyether polyol, the crosslinking density of the system is increased, significantly improving the mechanical properties of the waterproof coating; 2. The silane-modified polyether polyol of the present invention introduces hydrophobic silicon-containing segments into the high-functionality polyether polyol structure through oleic acid bridging. The high-functionality polyether polyol can introduce more oleic acid long chains and silicon-containing segments to construct a hydrophobic surface, effectively reducing the surface energy of the coating, further improving the intrinsic hydrophobicity of the material, and improving the stability and service life of the waterproof coating. 3. The single-component fluorine-free highly hydrophobic polyurethane waterproof coating of the present invention abandons fluorine-containing compounds, eliminates the risk of fluoride emissions from the source, and is both environmentally friendly and health-safe during use. DETAILED DESCRIPTION

[0015] The technical solution of the present invention will be clearly and completely described below in conjunction with embodiments.

[0016] Unless otherwise specified, all raw materials used in the examples are commercially available.

[0017] Some of the raw materials used in the examples and comparative examples are described as follows: INOVOLF330N (glyceryl polyether, functionality 3, number average molecular weight 5000g·mol -1 ), Shandong Yinuowei New Materials Co., Ltd.

[0018] INOVOLC230 (propylene glycol polyether, functionality 2, number average molecular weight 3000g•mol -1 ), Shandong Yinuowei New Materials Co., Ltd.

[0019] Silicone defoamer, model: TEGOFomaex800, purchased from Evonik Industries AG.

[0020] The preparation method of pentaerythritol polyether polyol is as follows: 272g of pentaerythritol and 4.95g of potassium hydroxide catalyst are added to a high-pressure reactor, the atmosphere is replaced with nitrogen three times, the temperature is raised to 110°C, and dehydration is carried out for 2 hours. 1378g of propylene oxide is continuously added to the reactor, the reaction temperature is controlled to be 110°C, and the pressure in the reactor is ≤0.3MPa. After the reaction is completed, the reaction is aged for 4h, the monomer is removed for 0.5h, and the pentaerythritol polyether polyol is prepared after acid water refining treatment. The hydroxyl value is 280.5mgKOH / g and the number average molecular weight is 800g•mol -1 .

[0021] The preparation method of the composite polyether polyol is as follows: 715g of castor oil, 188g of pentaerythritol polyether polyol and 0.2g of DMC catalyst are added to a high-pressure reactor, the temperature is raised to 130°C, 45g of propylene oxide is added dropwise to initiate the reaction, and after the pressure drops to -0.08MPa, the remaining 570g of propylene oxide and 3542g of 1,2-epoxyhexane are gradually added dropwise to the reactor, and the pressure in the reactor is controlled to be ≤0.3MPa. After the reaction is completed, the monomer is removed for 0.5h to prepare the composite polyether polyol with a functionality of 3, a hydroxyl value of 33.66mgKOH / g, and a number average molecular weight of 5000g•mol -1 .

[0022] The preparation method of sorbitol polyether polyol is as follows: 182g of sorbitol and 4.65g of potassium hydroxide catalyst are added to a high-pressure reactor, the atmosphere is replaced with nitrogen three times, the temperature is raised to 110°C, and dehydration is carried out for 2h. 1368g of propylene oxide is continuously added to the reactor, the reaction temperature is controlled to be 110°C, and the pressure in the reactor is ≤0.3MPa. After the reaction is completed, the reaction is aged for 4h, the monomer is removed for 0.5h, and the sorbitol polyether polyol is prepared after acid and water refining treatment. The hydroxyl value is 112.2mgKOH / g and the number average molecular weight is 1500g•mol -1 .

[0023] Example 1 The preparation steps of the silane-modified polyether polyol in Example 1 are as follows: 500 g of sorbitol polyether polyol, 383.52 g of oleic acid and 8.84 g of p-toluenesulfonic acid are added to a reactor equipped with a condenser, nitrogen is introduced for replacement three times, the temperature is raised to 160° C., and the reaction is stirred. During the reaction, by-products are continuously separated and evaporated through a distillation column, and the reaction is carried out for 8 h; the temperature is lowered to 80° C., 136 g of diethylmethylsilane and 0.08 g of chloroplatinic acid catalyst are added, and the reaction is carried out for 5 h. The infrared measurement wave number is 1640 cm -1 After the carbon-carbon double bond peak disappears, the addition reaction is completed and silane-modified polyether polyol is obtained.

[0024] The one-component fluorine-free highly hydrophobic polyurethane waterproof coating is composed of the following raw materials in parts by weight: Composite polyether polyol: 70 parts; Silane modified polyether polyol (Mn is 3036g•mol -1 ): 30 servings; Hexamethylene diisocyanate: 11 parts; Bisphenol A dihydroxypropyl ether: 3 parts; Kaolin: 40 parts; Fumed silica: 30 parts; Chlorinated paraffin: 50 parts; Dibutyltin dilaurate: 0.15 parts; Silicone defoamer TEGOFomaex800: 5 parts.

[0025] The preparation method of the one-component fluorine-free highly hydrophobic polyurethane waterproof coating comprises the following steps: S1. Add the composite polyether polyol, silane-modified polyether polyol, filler kaolin, fumed silica and plasticizer chlorinated paraffin into a reaction kettle, heat to 110° C., and vacuum dehydrate for 1.5 hours until the moisture content is below 0.04%; S2: Cool to 60°C, add hexamethylene diisocyanate, react at 75°C for 4 hours, then add bisphenol A dihydroxypropyl ether and continue to react for 3 hours; S3: After the -NCO% reaches 0.93%, cool to 30°C, add catalyst dibutyltin dilaurate and silicone defoamer TEGOFomaex800, and stir evenly to obtain a one-component fluorine-free highly hydrophobic polyurethane waterproof coating.

[0026] Example 2 The preparation steps of the silane-modified polyether polyol in Example 2 are as follows: 500 g of sorbitol polyether polyol, 383.52 g of oleic acid and 7.07 g of p-toluenesulfonic acid are added to a reactor with a condenser, nitrogen is introduced for replacement three times, the temperature is raised to 150° C., and the reaction is stirred. During the reaction, by-products are continuously separated and evaporated through a distillation column, and the reaction is carried out for 7 h; the temperature is lowered to 90° C., 136 g of diethylmethylsilane and 0.071 g of chloroplatinic acid catalyst are added, and the reaction is carried out for 6 h. The infrared measurement wave number is 1640 cm -1 After the carbon-carbon double bond peak disappears, the addition reaction is completed and silane-modified polyether polyol is obtained.

[0027] The one-component fluorine-free highly hydrophobic polyurethane waterproof coating is composed of the following raw materials in parts by weight: Composite polyether polyol: 60 parts; Silane modified polyether polyol (Mn is 3036g•mol -1 ): 40 servings; Diphenylmethane diisocyanate: 17 parts; Bisphenol A dihydroxypropyl ether: 2 parts; Fumed silica: 20 parts; Calcium carbonate: 30 parts; Epoxidized soybean oil: 70 parts; Dibutyltin dilaurate: 0.2 parts; Silicone defoamer TEGOFomaex800: 4 parts.

[0028] The preparation method of the one-component fluorine-free highly hydrophobic polyurethane waterproof coating comprises the following steps: S1. Add composite polyether polyol, silane-modified polyether polyol, filler fumed silica, calcium carbonate and plasticizer epoxidized soybean oil into a reactor, heat to 100° C., and vacuum dehydrate for 2.5 hours until the moisture content is below 0.04%; S2: Cool to 70°C, add diphenylmethane diisocyanate, react at 70°C for 4 hours, then add bisphenol A dihydroxypropyl ether and continue to react for 2 hours; S3: After the -NCO% reaches 1.1%, cool to 20°C, add catalyst dibutyltin dilaurate and silicone defoamer TEGOFomaex800, and stir evenly to obtain a one-component fluorine-free highly hydrophobic polyurethane waterproof coating.

[0029] Example 3 The preparation steps of the silane-modified polyether polyol in Example 3 are as follows: 500 g of sorbitol polyether polyol, 383.52 g of oleic acid and 13.25 g of p-toluenesulfonic acid are added to a reactor equipped with a condenser, nitrogen is introduced for replacement three times, the temperature is raised to 170° C., and the reaction is stirred. During the reaction, by-products are continuously separated and evaporated through a distillation column, and the reaction is carried out for 6 h; the temperature is lowered to 100° C., 154.67 g of triethylsilane and 0.10 g of chloroplatinic acid catalyst are added, and the reaction is carried out for 4 h. The infrared measurement wave number is 1640 cm -1 After the carbon-carbon double bond peak disappears, the addition reaction is completed and silane-modified polyether polyol is obtained.

[0030] The one-component fluorine-free highly hydrophobic polyurethane waterproof coating is composed of the following raw materials in parts by weight: Composite polyether polyol: 80 parts; Silane modified polyether polyol (Mn is 3092g•mol -1 ): 20 servings; Hexamethylene diisocyanate: 13 parts; Bisphenol A dihydroxypropyl ether: 5 parts; Kaolin: 25 parts; Calcium carbonate: 35 parts; Triethyl phosphate: 60 parts; Dibutyltin dilaurate: 0.18 parts; Silicone defoamer TEGOFomaex800: 3 parts.

[0031] The preparation method of the one-component fluorine-free highly hydrophobic polyurethane waterproof coating comprises the following steps: S1. Add composite polyether polyol, silane-modified polyether polyol, filler kaolin, calcium carbonate and plasticizer triethyl phosphate into a reaction kettle, heat to 110° C., and vacuum dehydrate for 1.5 hours until the moisture content is below 0.04%; S2: Cool to 70°C, add hexamethylene diisocyanate, react at 80°C for 3 hours, then add bisphenol A dihydroxypropyl ether and continue to react for 2 hours; S3: After the -NCO% reaches 1.15%, cool to 40°C, add catalyst dibutyltin dilaurate and silicone defoamer TEGOFomaex800, and stir evenly to obtain a one-component fluorine-free highly hydrophobic polyurethane waterproof coating.

[0032] Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that INOVOLF330N of equal quality is used instead of the complex polyether polyol.

[0033] Comparative Example 2 The difference between this comparative example 2 and example 1 is that INOVOLC230 of equal quality is used instead of silane-modified polyether polyol.

[0034] Comparative Example 3 The difference between this comparative example 3 and example 1 is that INOVOLF330N of the same quality is used instead of the composite polyether polyol; and INOVOLC230 of the same quality is used instead of the silane-modified polyether polyol.

[0035] Comparative Example 4 The difference between this comparative example 4 and example 1 is that propylene glycol-based polyoxypropylene ether diol (Mn is 344 g·mol -1 ) can replace bisphenol A dihydroxypropyl ether with equal quality.

[0036] Comparative Example 5 The difference between this comparative example 5 and example 1 is that the number average molecular weight of the -1 Castor oil-based polyether polyols (made by polymerizing propylene oxide and 1,2-epoxyhexane with castor oil as the initiator under the action of DMC catalyst, of which 1,2-epoxyhexane accounts for 60% of the total mass of castor oil, propylene oxide and 1,2-epoxyhexane) can replace composite polyether polyols by equal mass.

[0037] The polyurethane waterproof coatings obtained in the examples and comparative examples were tested according to the test standards in GB / T 19250-2013 and GB / T 30693-2014. The test results are shown in Table 1.

[0038] Table 1 Performance test results of examples and comparative examples

[0039] As shown in Table 1, the single-component, fluorine-free, highly hydrophobic waterproof coatings of Examples 1-3 exhibit both good mechanical properties and excellent hydrophobicity. The composite polyether polyols synthesized by copolymerizing propylene oxide and 1,2-epoxyhexane as a composite initiator are used to prepare waterproof coatings. The water absorption rate is significantly lower than that of finished waterproof coatings prepared from conventional polyethers. This is because the long carbon chains in castor oil molecules and the side chains of 1,2-epoxyhexane align on the coating surface, forming a hydrophobic layer. Furthermore, by designing the functionality of the composite polyether polyols, more crosslinking points can be formed during the reaction, improving the mechanical properties of the waterproof coating. By esterifying the high-functionality polyether polyols with oleic acid and then introducing silicon-containing segments, the ester bonds formed can greatly enhance the adhesion of the coating to the substrate. The silicon-containing segments and the long carbon chains in the oleic acid structure form a low-surface-energy silane network on the coating surface, significantly reducing the coating's affinity for water, increasing the water contact angle, and reducing water penetration. Furthermore, the benzene ring structure contained in the chain extender further enhances the material's hydrophobicity. These improvements in performance can significantly enhance the application scenarios of polyurethane waterproof coatings in outdoor or harsh environments. In Comparative Example 5, compared to Example 1, replacing the composite polyether polyol with a castor oil polyether polyol using only castor oil as an initiator reduces functionality, leading to an increase in elongation at break. Furthermore, since castor oil is more hydrophobic, the hydrophobic effect is slightly better, but mechanical strengths such as tensile and tear properties are significantly reduced. Therefore, the present invention can achieve both mechanical strength and hydrophobic properties.

Claims

1. A one-component fluorine-free highly hydrophobic polyurethane waterproof coating, characterized in that: It is composed of the following raw materials in parts by weight: Composite polyether polyol: 60-80 parts; Silane-modified polyether polyol: 20-40 parts; Diisocyanate: 11-17 parts; Chain extender: 2~5 parts; Plasticizer: 50~70 parts; Filler: 50~70 parts; Catalyst: 0.15~0.2 parts; Additives: 3~5 parts; Composite polyether polyol is obtained by polymerizing propylene oxide and 1,2-epoxyhexane with castor oil and pentaerythritol polyether polyol as initiators under the action of DMC catalyst. 1,2-epoxyhexane accounts for 50%-70% of the total mass of castor oil, pentaerythritol polyether polyol, propylene oxide and 1,2-epoxyhexane, and has a number average molecular weight of 5000g•mol -1 , functionality is 3; wherein; Pentaerythritol polyether polyol is obtained by polymerizing propylene oxide with pentaerythritol as the initiator under the action of KOH catalyst, with a number average molecular weight of 800g•mol -1 , functionality is 4; The preparation steps of silane-modified polyether polyol are as follows: sorbitol polyether polyol and oleic acid are subjected to esterification reaction, and after the reaction, alkyl hydrogen silane is added for addition reaction to obtain the obtained product. Sorbitol polyether polyol is obtained by polymerization of propylene oxide with sorbitol as the initiator under the action of KOH catalyst, and has a number average molecular weight of 1500 g·mol -1 , functionality is 6; the alkyl hydrogen silane is one of diethylmethyl hydrogen silane and triethyl hydrogen silane.

2. The one-component fluorine-free highly hydrophobic polyurethane waterproof coating according to claim 1, characterized in that: The preparation steps of silane-modified polyether polyol are as follows: sorbitol polyether polyol, oleic acid and p-toluenesulfonic acid are added to a reactor equipped with a condenser, nitrogen is introduced for replacement three times, the temperature is raised to 150-170°C, and the reaction is stirred. During the reaction, by-products are continuously separated and evaporated through a distillation column, and the reaction is carried out for 6-8 hours; the temperature is lowered to 80-100°C, alkyl hydrogen silane and chloroplatinic acid catalyst are added, and the reaction is carried out for 4-6 hours. The infrared measurement wave number is 1640 cm -1 After the carbon-carbon double bond peak disappears, the addition reaction is completed to obtain the silane-modified polyether polyol; the molar ratio of sorbitol polyether polyol, oleic acid and alkyl hydrogen silane is 1:4.08:4; the amount of chloroplatinic acid catalyst is 70-100 ppm of the total amount of sorbitol polyether polyol, oleic acid and alkyl hydrogen silane.

3. The one-component fluorine-free highly hydrophobic polyurethane waterproof coating according to claim 1, characterized in that: The diisocyanate is one of hexamethylene diisocyanate and diphenylmethane diisocyanate.

4. The one-component fluorine-free highly hydrophobic polyurethane waterproof coating according to claim 1, characterized in that: The filler is one or more of kaolin, fumed silica or calcium carbonate.

5. The one-component fluorine-free highly hydrophobic polyurethane waterproof coating according to claim 1, characterized in that: The chain extender is bisphenol A dihydroxypropyl ether.

6. The one-component fluorine-free highly hydrophobic polyurethane waterproof coating according to claim 1, characterized in that: The plasticizer is one of chlorinated paraffin, epoxidized soybean oil and triethyl phosphate.

7. The one-component fluorine-free highly hydrophobic polyurethane waterproof coating according to claim 1, characterized in that: The catalyst is dibutyltin dilaurate.

8. The one-component fluorine-free highly hydrophobic polyurethane waterproof coating according to claim 1, characterized in that: The auxiliary agent is a silicone defoamer.

9. A method for preparing the one-component fluorine-free highly hydrophobic polyurethane waterproof coating according to any one of claims 1 to 8, characterized in that: Here are the steps: S1. Add the composite polyether polyol, silane-modified polyether polyol, filler, and plasticizer into a reaction kettle, heat to 100-110°C, and vacuum dehydrate until the moisture content is below 0.04%; S2: Cool down to 60~70℃, add diisocyanate, react at 70~80℃ for 3~4h, then add chain extender and continue to react for 2~3h; S3: After the -NCO% reaches 0.93%-1.15%, cool to 20~40℃, add catalyst and additives, and stir evenly to obtain a one-component fluorine-free highly hydrophobic polyurethane waterproof coating.

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