One-component fluorine-containing silicone polyurethane waterproof coating and preparation method thereof

Abstract

The application belongs to the technical field of waterproof coating and specifically relates to a single-component fluorine-silicon polyurethane waterproof coating and a preparation method thereof. The single-component fluorine-silicon polyurethane waterproof coating is composed of the following raw materials in parts by weight: fluorine-silicon modified polymer I, 40-60 parts; fluorine-silicon modified polymer II, 60-40 parts; filler, 15-25 parts; plasticizer, 15-25 parts; catalyst, 0.05-0.08 parts; and auxiliary agent, 2-6 parts. The application improves the hydrophobic property of the waterproof material; the waterproof coating is cured by a silicon-oxy group moisture, and no bubbles are generated in the curing process. The application further provides a preparation method of the waterproof coating.

Description

Technical Field

[0001] This invention belongs to the field of waterproof coating technology, specifically relating to a single-component fluorinated silicone polyurethane waterproof coating and its preparation method. Background Technology

[0002] Traditional single-component polyurethane waterproof coatings are widely used in building waterproofing and bridge and tunnel waterproofing projects due to their excellent elasticity, abrasion resistance, and corrosion resistance. They also hold a high market share due to their ease of application and rapid development. However, because these coatings contain -NCO groups, they often generate bubbles during the curing process, which affects the overall performance of the material. In terms of existing technology, Chinese patent CN116970339A discloses a single-component self-cleaning polyurethane waterproof coating and its preparation method. This coating achieves hydrophobicity by introducing castor oil-based polyoxybutylene ether polyol and reactive fluorosilicone segments. However, the curing of this coating still mainly relies on the moisture curing mechanism of the -NCO groups, and the bubble problem during curing remains unresolved. Another Chinese patent, CN113603881A, discloses a fluorinated polytetrahydrofuran diol and its preparation method, a fluorinated polyurethane waterproof coating and its composition, preparation method and application. It improves the hydrophobicity of the material by introducing fluorinated polyol, but the preparation process requires the use of liquid nitrogen and acetone, an organic solvent that is easy to produce poison and explosive. Moreover, the contact angle of the waterproof coating is only 110°, and there is still room for improvement in the hydrophobic effect. Summary of the Invention

[0003] To address the aforementioned technical problems, this invention provides a single-component fluorosilicone polyurethane waterproof coating. Fluorosilicone segments are introduced into the polyurethane waterproof coating through a polymerization reaction, improving the hydrophobic properties of the waterproof material. The waterproof coating is cured by silicone-based moisture, with no bubbles generated during the curing process. Another objective of this invention is to provide a method for preparing a single-component fluorosilicone polyurethane waterproof coating. This method has simple preparation steps, does not involve hazardous raw materials or high-temperature, high-pressure reactions, and is easy for industrial production.

[0004] The single-component fluorosilicone polyurethane waterproof coating of the present invention is composed of the following raw materials in parts by weight: Fluorosilicone modified polymer I, 40-60 parts; Fluorosilicone modified polymer II, 60-40 parts; Filler, 15-25 parts; Plasticizer, 15-25 parts; Catalyst, 0.05-0.08 parts; Additives, 2-6 parts; Fluorosilicone modified polymer I is prepared by polymerization reaction of tetraglycerol polyether polyol, isocyanate, perfluorodecyl mercaptan, and silane coupling agent; Fluorosilicone modified polymer II is prepared by polymerization reaction of dimethylolcyclohexyl polyether, isocyanate, perfluorodecyl mercaptan, and silane coupling agent; The isocyanate is hexamethylene diisocyanate (HDI, molecular weight 168.19).

[0005] Preferably, in the fluorosilicone modified polymer I, the tetraglycerol-based polyether polyol has a number-average molecular weight of 6000 and is obtained by catalytic polymerization of propylene oxide under the action of a catalyst; the silane coupling agent is KH540.

[0006] Preferred method for preparing fluorosilicone modified polymer I: S1, tetraglycerol polyether polyol and isocyanate were reacted at 70-80℃ for 2h to obtain -NCO-terminated polyurethane prepolymer; S2. Add perfluorodecyl mercaptan to the above polyurethane prepolymer, continue the reaction for 2 hours, then add silane coupling agent and continue the reaction until -NCO is completely reacted to obtain the product.

[0007] Preferably, the molar ratio of tetraglycerol polyether to isocyanate is 1:6; and the molar ratio of perfluorodecyl mercaptan to silane coupling agent is 2:1.

[0008] Preferably, in the fluorosilicone modified polymer II, the dimethylolcyclohexyl polyether has a number-average molecular weight of 2000 and is prepared by the polymerization of propylene oxide catalyzed by dimethylolcyclohexane under the action of a catalyst; the silane coupling agent is KH540.

[0009] Preferred method for preparing fluorosilicone modified polymer II: S1, dihydroxymethylcyclohexyl polyether and isocyanate were reacted at 70-80℃ for 2h to obtain -NCO-terminated polyurethane prepolymer; S2. Add perfluorodecyl mercaptan to the above polyurethane prepolymer, continue the reaction for 2 hours, then add silane coupling agent and continue the reaction until -NCO is completely reacted to obtain the product.

[0010] Preferably, the molar ratio of dihydroxymethylcyclohexyl polyether to isocyanate is 1:2; and the molar ratio of perfluorodecyl mercaptan to silane coupling agent is 2:1.

[0011] Preferably, the filler is silica; the plasticizer is chlorinated paraffin and No. 150 solvent oil; the catalyst is dibutyltin dilaurate; and the additive is a silane coupling agent.

[0012] Preferably, the silane coupling agent used as an adjuvant is tridecafluorooctyltrimethoxysilane or tridecafluorooctyltriethoxysilane.

[0013] The preparation method of the single-component fluorosilicone polyurethane waterproof coating of the present invention comprises the following steps: S1: Mix the filler and plasticizer evenly and dehydrate under vacuum to control the moisture content ≤500ppm; S2: Add fluorosilicone modified polymer I and fluorosilicone modified polymer II to the above mixture, stir evenly, then add the additives and catalyst, stir evenly, and the mixture is obtained.

[0014] Compared with the prior art, the beneficial effects of the present invention are: 1. This invention introduces hydrophobic fluorinated long carbon chains and silane segments into modified polymers through the bridging effect of isocyanate, and at the same time introduces active reactive groups - siloxy groups, for the preparation of waterproof coatings. On the one hand, it can improve the hydrophobicity of the material, and on the other hand, it can achieve moisture crosslinking and curing. 2. The waterproof coating of this invention does not contain free -NCO groups, which can avoid the defect of easy bubble generation during the moisture curing process of traditional polyurethane waterproof coatings; 3. This invention uses aliphatic isocyanate, which can avoid the problem of waterproof coatings turning yellow easily under outdoor conditions. Detailed Implementation

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

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

[0017] INOVOL C220, a 2-functionality, 2000 molecular weight propylene glycol initiator polyether polyol, was purchased from Shandong Yinuowei New Materials Co., Ltd.

[0018] INOVOL F3600, a trifunctional, 6000 molecular weight glycerol initiator polyether polyol, was purchased from Shandong Yinuowei New Materials Co., Ltd.

[0019] Tetraglyceride-based polyether polyol: 314g of polyglycerol-4 was polymerized in 5940g of propylene oxide under the catalysis of 0.2g of DMC bimetallic catalyst. After the reaction was complete, unreacted monomers were removed by vacuum to obtain the polyether polyol with a number average molecular weight of 6000.

[0020] Dimethylolcyclohexyl polyether polyol: 144g of dimethylolcyclohexane was subjected to polymerization of 1880g of propylene oxide under the catalysis of 0.07g of DMC bimetallic catalyst. After the reaction was complete, unreacted monomers were removed by vacuum to obtain the polyether polyol with a number average molecular weight of 2000.

[0021] Preparation of fluorosilicone modified polymer I: S1. 6000g of tetraglycerol polyether polyol and 1009g of HDI were reacted at 75°C for 2h to obtain -NCO-terminated polyurethane prepolymer. S2. Add 1920.72g of perfluorodecyl mercaptan to the above polyurethane prepolymer, continue the reaction for 2 hours, then add 359g of KH540, and continue the reaction until -NCO is completely reacted to obtain the product.

[0022] Preparation of fluorosilicone modified polymer II: S1. 2000g of dimethylolcyclohexyl polyether polyol and 336g of HDI were reacted at 75°C for 2h to obtain -NCO-terminated polyurethane prepolymer. S2. Add 640g of perfluorodecyl mercaptan to the above polyurethane prepolymer, continue the reaction for 2 hours, then add 119.5g of KH540, and continue the reaction until -NCO is completely reacted to obtain the product.

[0023] Example 1 The single-component fluorosilicone polyurethane waterproof coating is composed of the following raw materials in parts by weight: Fluorosilicone modified polymer I, 50 parts; Fluorosilicone modified polymer II, 50 parts; 20 parts of silica; Plasticizer (chlorinated paraffin and No. 150 solvent oil, mass ratio 1:1), 20 parts; Dibutyltin dilaurate, 0.05 parts; Tridecafluorooctyltriethoxysilane, 2 parts.

[0024] The method for preparing the single-component fluorinated silicone polyurethane waterproof coating is characterized by the following steps: S1: Mix the filler silica and plasticizer evenly, and vacuum dehydrate to control the moisture content ≤500ppm; S2: Add fluorosilicone modified polymer I and fluorosilicone modified polymer II to the above mixture, stir evenly, then add the auxiliary agent tridecylfluorotriethoxysilane and the catalyst dibutyltin dilaurate, stir evenly, and the mixture is obtained.

[0025] Example 2 The single-component fluorosilicone polyurethane waterproof coating is composed of the following raw materials in parts by weight: Fluorosilicone modified polymer I, 40 parts; Fluorosilicone modified polymer II, 60 parts; Silica, 25 parts; Plasticizer (chlorinated paraffin and No. 150 solvent oil, mass ratio 1:1), 15 parts; Dibutyltin dilaurate, 0.08 parts; Tridecafluorooctyltrimethoxysilane, 4 parts.

[0026] The method for preparing the single-component fluorinated silicone polyurethane waterproof coating is characterized by the following steps: S1: Mix the filler silica and plasticizer evenly, and vacuum dehydrate to control the moisture content ≤500ppm; S2: Add fluorosilicone modified polymer I and fluorosilicone modified polymer II to the above mixture, stir evenly, then add the auxiliary agent tridecafluorooctyltrimethoxysilane and the catalyst dibutyltin dilaurate, stir evenly, and the mixture is obtained.

[0027] Example 3 The single-component fluorosilicone polyurethane waterproof coating is composed of the following raw materials in parts by weight: Fluorosilicone modified polymer I, 60 parts; Fluorosilicone modified polymer II, 40 parts; 15 parts of silica; Plasticizer (chlorinated paraffin and No. 150 solvent oil, mass ratio 1:1), 25 parts; Dibutyltin dilaurate, 0.06 parts; Tridecafluorooctyltriethoxysilane, 6 parts.

[0028] The method for preparing the single-component fluorinated silicone polyurethane waterproof coating is characterized by the following steps: S1: Mix the filler silica and plasticizer evenly, and vacuum dehydrate to control the moisture content ≤500ppm; S2: Add fluorosilicone modified polymer I and fluorosilicone modified polymer II to the above mixture, stir evenly, then add the auxiliary agent tridecafluorooctyltriethoxysilane and the catalyst dibutyltin dilaurate, stir evenly, and the mixture is obtained.

[0029] Comparative Example 1 The difference between Comparative Example 1 and Example 3 is that an equimolar amount of n-decyl mercaptan was used to replace perfluorodecyl mercaptan in the preparation of fluorosilicone modified polymer I and fluorosilicone modified polymer II.

[0030] Comparative Example 2 The difference between Comparative Example 2 and Example 3 is that equimolar amounts of methylphenyl diisocyanate were used to replace HDI in the preparation of fluorosilicone modified polymer I and fluorosilicone modified polymer II.

[0031] Comparative Example 3 The difference between Comparative Example 3 and Example 3 is that the fluorosilicone modified polymer II was prepared by polymerizing it by replacing dihydroxymethylcyclohexyl polyether polyol with an equimolar amount of INOVOL C220.

[0032] Comparative Example 4 The difference between Comparative Example 4 and Example 3 is that the fluorosilicone modified polymer I is polymerized from 1 mol INOVOL F3600, 3 mol HDI, 1 mol perfluorodecyl mercaptan and 2 mol KH540.

[0033] Performance testing The performance of the waterproof coatings prepared in the examples and comparative examples was tested in accordance with GB / T 19250-2013 and GB / T 30693-2014, and the test results are shown in Table 1.

[0034] Table 1 Performance Test Results

[0035] The test data above shows that the waterproof coating prepared by this invention has good hydrophobicity due to the introduction of hydrophobic elements and hydrophobic groups; at the same time, since it has no benzene ring structure, its appearance does not change significantly after ultraviolet irradiation, and since it has no free -NCO groups, there are no obvious bubbles after curing. The improvement of the above properties can enrich its application scenarios.

[0036] Compared with Example 3, Comparative Example 1, which contains no hydrophobic fluorine, exhibits the smallest contact angle, high water absorption, and the worst hydrophobicity. The main difference in Comparative Example 2 is that it contains a benzene ring structure, which causes the product to turn yellow when exposed to ultraviolet light. The fluorosilicone modified polymer II used in Comparative Example 3 does not contain a cyclohexane structure, resulting in a slight decrease in hydrophobicity. The fluorosilicone modified polymer I in Comparative Example 4 uses a conventional glycerol-based polyether, which introduces limited fluorine, and its hydrophobicity also decreases significantly.

Claims

1. A single-component fluorosilicone polyurethane waterproof coating, characterized in that, It consists of the following raw materials in parts by weight: Fluorosilicone modified polymer I, 40-60 parts; Fluorosilicone modified polymer II, 60-40 parts; Filler, 15-25 parts; Plasticizer, 15-25 parts; Catalyst, 0.05-0.08 parts; Additives, 2-6 parts; Fluorosilicone modified polymer I is prepared by polymerization reaction of tetraglycerol polyether polyol, isocyanate, perfluorodecyl mercaptan, and silane coupling agent; Fluorosilicone modified polymer II is prepared by polymerization reaction of dimethylolcyclohexyl polyether, isocyanate, perfluorodecyl mercaptan, and silane coupling agent; The isocyanate is hexamethylene diisocyanate.

2. The single-component fluorosilicone polyurethane waterproof coating according to claim 1, characterized in that, In fluorosilicone modified polymer I, the number-average molecular weight of the tetraglycerol-based polyether polyol is 6000, which is obtained by catalytic polymerization of propylene oxide under the action of a catalyst; the silane coupling agent is KH540.

3. The single-component fluorosilicone polyurethane waterproof coating according to claim 2, characterized in that, Preparation method of fluorosilicone modified polymer I: S1, tetraglycerol polyether polyol and isocyanate were reacted at 70-80℃ for 2h to obtain -NCO-terminated polyurethane prepolymer; S2. Add perfluorodecyl mercaptan to the above polyurethane prepolymer, continue the reaction for 2 hours, then add silane coupling agent and continue the reaction until -NCO is completely reacted to obtain the product.

4. The single-component fluorosilicone polyurethane waterproof coating according to claim 3, characterized in that, The molar ratio of tetraglycerol polyether to isocyanate is 1:6; the molar ratio of perfluorodecyl mercaptan to silane coupling agent is 2:

1.

5. The single-component fluorosilicone polyurethane waterproof coating according to claim 1, characterized in that, In the fluorosilicone modified polymer II, the dimethylolcyclohexyl polyether has a number-average molecular weight of 2000 and is prepared by the polymerization of propylene oxide catalyzed by dimethylolcyclohexane under the action of a catalyst; the silane coupling agent is KH540.

6. The single-component fluorosilicone polyurethane waterproof coating according to claim 5, characterized in that, Preparation method of fluorosilicone modified polymer II: S1, dihydroxymethylcyclohexyl polyether and isocyanate were reacted at 70-80℃ for 2h to obtain -NCO-terminated polyurethane prepolymer; S2. Add perfluorodecyl mercaptan to the above polyurethane prepolymer, continue the reaction for 2 hours, then add silane coupling agent and continue the reaction until -NCO is completely reacted to obtain the product.

7. The single-component fluorosilicone polyurethane waterproof coating according to claim 6, characterized in that, The molar ratio of dimethylolcyclohexyl polyether to isocyanate is 1:2; the molar ratio of perfluorodecyl mercaptan to silane coupling agent is 2:

1.

8. The single-component fluorosilicone polyurethane waterproof coating according to claim 1, characterized in that, The filler is silica; the plasticizer is chlorinated paraffin and No. 150 solvent oil; the catalyst is dibutyltin dilaurate; and the additive is silane coupling agent.

9. The single-component fluorosilicone polyurethane waterproof coating according to claim 8, characterized in that, The silane coupling agent used as an adjuvant is tridecafluorooctyltrimethoxysilane or tridecafluorooctyltriethoxysilane.

10. A method for preparing a single-component fluorosilicone polyurethane waterproof coating according to any one of claims 1-9, characterized in that, The steps are as follows: S1: Mix the filler and plasticizer evenly and dehydrate under vacuum to control the moisture content ≤500ppm; S2: Add fluorosilicone modified polymer I and fluorosilicone modified polymer II to the above mixture, stir evenly, then add the additives and catalyst, stir evenly, and the mixture is obtained.

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