Odorless environment-friendly single-component polyurethane waterproof coating and preparation method thereof

Abstract

The present application relates to the technical field of paint, especially to a kind of odorless environment-friendly single-component polyurethane waterproof coating and preparation method thereof.The preparation raw material of single-component polyurethane waterproof coating provided by the present application does not include latent curing agent, and includes the following components by weight: polyether polyol 140-245 parts;Small molecule chain extender 0.5-1.5 parts;Diisocyanate 38-42 parts;Stabilizer 0.1-0.3 parts;Carbon dioxide absorbent 1.0-8.0 parts;Catalyst 0.5-1.0 parts;The catalyst is chelated tin catalyst.Polyether polyol includes polytetrahydrofuran polyol 20-60 parts;Single-component polyurethane waterproof coating provided by the present application has excellent environmental protection, long storage period, good workability and high tensile strength, high elongation at break and strong adhesive strength, etc.Excellent mechanical properties.

Description

Technical Field

[0001] This invention relates to the field of coating technology, and in particular to an odorless, environmentally friendly, single-component polyurethane waterproof coating and its preparation method. Background Technology

[0002] Polyurethane waterproof coatings, as an important application component of polyurethane synthetic materials, have become one of the main materials in the field of building waterproofing due to their unique performance advantages. These coatings feature good film elasticity, excellent elongation, strong adhesion, and low volume shrinkage, forming a seamless waterproof layer that exhibits strong adaptability to the expansion and contraction deformation of substrate cracks. Furthermore, they are easy to apply and maintain, can be easily applied to any complex substrate surface, and are widely used in waterproofing and leak-stopping projects in various parts of buildings.

[0003] In recent years, single-component polyurethane waterproof coatings have gained market favor due to their numerous advantages and are gradually becoming the development direction of polyurethane waterproof coatings. Compared with two-component coatings, single-component coatings eliminate measurement errors during construction, require less specialized skills from construction personnel, have lower viscosity, and are easier to apply. Furthermore, they offer advantages such as a long pot life, stable performance, ease of use, and wide applicability, leading to continuous growth in their usage and widespread user recognition.

[0004] However, the mainstream single-component polyurethane waterproof coatings on the market still face multiple technical challenges: (1) Environmental friendliness issues: Most of the commercially available single-component polyurethane waterproof coatings are solvent-based products. Although the addition of organic solvents helps to reduce the viscosity of the coating and improve its application performance, the content of volatile organic compounds (VOCs) in the coating also increases with the increase of the amount of solvents added, which is contrary to the increasingly stringent environmental regulations.

[0005] (2) Odor and health issues: Even some paints that do not contain organic solvents may release low molecular weight aldehydes, such as formaldehyde, acetaldehyde, benzaldehyde, and isobutyraldehyde, during the curing process of the paint using conventional latent curing agents. The volatilization of these aldehydes not only contributes to VOC emissions but also produces irritating odors, which can have adverse effects on the health of construction workers, especially in relatively enclosed construction spaces.

[0006] (3) Limitations of conventional latent curing agents: Although the addition of conventional latent curing agents aims to solve the problems of foaming in the construction coating and improve the poor storage stability of single-component polyurethane waterproof coatings (for example, to avoid excessive viscosity growth during storage, especially after high-temperature storage, which can lead to performance degradation, affect construction, or even curing), they also have their shortcomings. Due to their high activity, conventional latent curing agent systems are prone to hydrolysis during storage, resulting in increased product viscosity. Generally speaking, the viscosity growth rate of such products may be as high as 40% or more after 3-6 months of storage. The longer the storage time, the greater the viscosity growth, resulting in a short product shelf life that cannot meet the actual product turnover and shelf-life requirements.

[0007] Therefore, how to prepare an environmentally friendly single-component polyurethane waterproof coating that does not bubble during construction, has extremely low VOC content, good storage stability, long shelf life, and is odorless has become an urgent technical problem to be solved. Summary of the Invention

[0008] This invention provides an odorless, environmentally friendly, single-component polyurethane waterproof coating and its preparation method, which solves the problems of existing single-component polyurethane waterproof coatings, such as high VOC content, irritating odor during construction, easy blistering of the coating film, and poor product storage stability.

[0009] According to a first aspect of the present invention, the present invention provides an odorless and environmentally friendly one-component polyurethane waterproof coating, the raw materials for which do not include a latent curing agent, and include the following components: 140-245 parts by weight of polyether polyol; 0.5~1.5 parts by weight of small molecule chain extender; 38-42 parts by weight of diisocyanate; Stabilizer 0.1~0.3 parts by weight; Carbon dioxide absorbent: 1.0~8.0 parts by weight; Catalyst: 0.5~1.0 parts by weight; The catalyst is a chelated tin catalyst; The polyether polyol includes polytetrahydrofuran polyol, and the polytetrahydrofuran polyol is present in a quantity of 20-60 parts by weight.

[0010] The single-component polyurethane waterproof coating formulation provided by this invention does not use conventional latent curing agents, fundamentally eliminating the release of irritating substances such as formaldehyde and acetaldehyde due to the decomposition of latent curing agents. This results in a truly odorless, environmentally friendly product with extremely low VOC content. This invention employs a specific material combination, with synergistic effects between the components, achieving excellent mechanical properties even without the addition of latent curing agents. The product exhibits high strength, large elongation, good stability, minimal viscosity change during long-term storage, and no bubbling after application.

[0011] According to the odorless and environmentally friendly single-component polyurethane waterproof coating of the present invention, the chelated tin catalyst includes one or more of tin acetylacetone, tin octanoyl acetone, pentaerythritol tin, trimethylolpropane tin, diethanolamine tin, and triethanolamine tin.

[0012] Chelated tin catalysts exhibit low activity during sealed storage, resulting in excellent storage stability and a significantly extended shelf life, thus solving the problem of excessive viscosity increase in traditional products. During application, the catalyst rapidly regains high activity upon contact with moisture in the air, ensuring a normal curing speed. Experiments have shown that, compared to organotin catalysts (such as dibutyltin dicerylsilicate) used in existing products, the chelated tin catalysts employed in this invention result in better film formation and storage stability in single-component polyurethane waterproof coatings after application, with a lower viscosity increase after 30 days of heat storage.

[0013] According to the odorless and environmentally friendly single-component polyurethane waterproof coating of the present invention, the stabilizer is one or more of benzoyl chloride, p-toluenesulfonyl chloride, acid anhydride and vinyltrimethoxysilane, preferably benzoyl chloride.

[0014] The single-component polyurethane waterproof coating provided by this invention incorporates a certain amount of stabilizer to absorb moisture from raw material residues during production and from external sources entering the packaging container during storage, thus addressing the issue of increased product viscosity caused by the reaction of NCO with water during storage. Experiments have demonstrated that these stabilizers significantly improve the storage stability of the coating.

[0015] According to the odorless, environmentally friendly, single-component polyurethane waterproof coating of the present invention, the polyether polyol further includes, but is not a polytetrahydrofuran polyol: 75-100 parts by weight of polyether diol and 45-85 parts by weight of polyether triol. This specific ratio achieves an effective balance between soft and hard segments, enabling the cured coating to maintain high flexibility while also possessing excellent mechanical strength.

[0016] Preferably, the polyether diol has a number-average molecular weight of 1000-2000, a functionality of 2, and a hydroxyl value of 56.1-112.2 mgKOH / g.

[0017] Preferably, the polyether diol is selected from at least one of DL-1000D and DL-2000D. In some specific embodiments, the polyether diol is selected from DL-2000D or DL-1000D purchased from Shandong Lanxing Dongda Co., Ltd.

[0018] Preferably, the polyether triol has a number-average molecular weight of 1000-5000, a functionality of 3, and a hydroxyl value of 33.66-56.1 mgKOH / g.

[0019] Preferably, the polyether triol is selected from at least one of MN1000 and EP330N.

[0020] In some specific embodiments, the polyether triol is selected from EP330N or MN1000 purchased from Shandong Lanxing Dongda Co., Ltd.

[0021] The single-component polyurethane waterproof coating provided by this invention introduces polytetrahydrofuran polyol and small molecule chain extender into polyether polyol, which solves the problems of poor tear strength and adhesive strength caused by the lack of urethane and urea bonds and poor chain segment regularity on polymer segments in the non-solidification system, so that the cured coating film has excellent mechanical properties.

[0022] According to the odorless and environmentally friendly single-component polyurethane waterproof coating of the present invention, the polytetrahydrofuran polyol is a polytetrahydrofuran diol, which can effectively enhance the coating's resistance to tearing and damage and its adhesion to the substrate without sacrificing other properties, thereby improving the overall reliability and service life of the waterproof coating.

[0023] Preferably, the number average molecular weight of the polytetrahydrofuran diol is 1000-2000.

[0024] In some specific embodiments, the polytetrahydrofuran diol is selected from PTMG-1000 or PTMG-2000 of Guangzhou Zhanhong Trading Co., Ltd.

[0025] According to the odorless and environmentally friendly single-component polyurethane waterproof coating of the present invention, the small molecule chain extender is selected from one or more of diamine chain extenders or diol chain extenders; the diamine chain extender includes one or more of isophorone diamine, ethylenediamine, dimethylthiotoluene diamine, and diethyltoluene diamine; the diol chain extender includes one or more of 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and 1,4-cyclohexanediol.

[0026] The odorless and environmentally friendly single-component polyurethane waterproof coating of the present invention is prepared by the following raw material components: 150-260 parts by weight of pigments and fillers.

[0027] According to the odorless and environmentally friendly single-component polyurethane waterproof coating of the present invention, the pigments and fillers are selected from one or more of nano-calcium carbonate, talc, fumed silica, heavy calcium carbonate, kaolin, wollastonite powder, mica powder, titanium dioxide and carbon black.

[0028] According to the odorless and environmentally friendly single-component polyurethane waterproof coating of the present invention, the diisocyanate is selected from one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate.

[0029] According to the odorless and environmentally friendly single-component polyurethane waterproof coating of the present invention, the carbon dioxide absorbent is selected from one or more of zeolite, activated carbon, calcium oxide, magnesium oxide, molecular sieve, diatomaceous earth and polystyrene-divinylbenzene resin.

[0030] The addition of carbon dioxide absorbent can absorb trace amounts of carbon dioxide that may be generated during the reaction, thereby effectively preventing blistering of the coating and ensuring the density and integrity of the waterproof layer. It also further reduces the VOC contribution value caused by carbon dioxide emissions.

[0031] In some specific embodiments, the carbon dioxide absorbent is selected from molecular sieves. Optionally, the molecular sieve includes one or more of type A molecular sieves, type X molecular sieves, and type Y molecular sieves. Preferably, the molecular sieve has a pore size of 0.5-1.0 nm and a specific surface area of ​​500-1000 m². 2 / g.

[0032] Type A molecular sieve: cubic crystal system, LTA-type framework structure, performance characteristics: uniform pore size, strong selectivity for small molecule adsorption, large adsorption capacity, especially outstanding adsorption capacity for water and carbon dioxide.

[0033] X and Y type molecular sieves: cubic crystal system, large pore size, extremely high specific surface energy, many adsorption and catalytic active sites, and can adsorb large molecules.

[0034] The odorless and environmentally friendly single-component polyurethane waterproof coating of the present invention is prepared by further comprising the following raw material components: 100-150 parts by weight of plasticizer.

[0035] Appropriate amounts of plasticizer can effectively reduce the viscosity of the entire formulation system, giving the finished coating good flowability and workability, while also significantly improving the flexibility of the cured coating film.

[0036] Preferably, the plasticizer is selected from one or more of vegetable oil esters, trioctyl phosphate, citrate, tributyl acetylacetate, and chlorinated paraffin plasticizers.

[0037] The odorless, environmentally friendly, single-component polyurethane waterproof coating according to the present invention is prepared from raw materials that do not include a latent curing agent, and includes the following components: 80-100 parts by weight of polyether diol; 50-85 parts by weight of polyether triol; 20-60 parts by weight of polytetrahydrofuran polyol; 0.5~1.5 parts by weight of small molecule chain extender; Plasticizer 100-150 parts by weight; Pigments and fillers: 150-260 parts by weight; 38-42 parts by weight of diisocyanate; Stabilizer 0.1~0.3 parts by weight; Carbon dioxide absorbent: 1.0~8.0 parts by weight; Catalyst 0.5~1.0 parts by weight.

[0038] Preferably, the odorless, environmentally friendly, single-component polyurethane waterproof coating according to the present invention is prepared from raw materials that do not include a latent curing agent, and includes the following components: 80-100 parts by weight of polyether diol; 50-65 parts by weight of polyether triol; 20-30 parts by weight of polytetrahydrofuran polyol; Small molecule chain extender, 0.5~1.0 parts by weight; Plasticizer 100-150 parts by weight; Pigments and fillers: 150-260 parts by weight; 38-42 parts by weight of diisocyanate; Stabilizer 0.2~0.3 parts by weight; 1-5 parts by weight of carbon dioxide absorbent; Catalyst 0.8~1.0 parts by weight.

[0039] The present invention also provides a method for preparing the above-mentioned odorless and environmentally friendly single-component polyurethane waterproof coating, comprising the following steps: Polyether polyol, polytetrahydrofuran polyol, small molecule chain extender and pigments and fillers are mixed to obtain a mixed slurry; Diisocyanate and part of the catalyst are added to the mixed slurry at 70-80°C, the temperature is raised to 75-85°C, and the reaction is carried out for 2-3 hours; then carbon dioxide absorbent is added at 75-85°C, and the reaction is continued with stirring; then the temperature is lowered to 55-65°C, and the remaining catalyst and stabilizer are added.

[0040] This invention precisely controls the reaction process, effectively avoids side reactions, and ensures that the product can be thickly coated without bubbling and has excellent storage stability, overcoming the technical bottlenecks of single-component coatings being prone to failure and having limited application.

[0041] According to the preparation method of the odorless and environmentally friendly single-component polyurethane waterproof coating of the present invention, the mixed slurry is dehydrated and then the diisocyanate and part of the catalyst are added; preferably, the dehydration is carried out at a temperature of 100 to 110°C and a relative vacuum of -0.08 to -0.1 MPa for 2 to 3 hours.

[0042] This invention employs specific conditions for efficient and thorough dehydration of the mixed slurry, maximizing the removal of free water from the system. This fundamentally eliminates the side reactions between highly reactive diisocyanate (-NCO groups) and water in subsequent processes, effectively preventing issues such as container swelling during coating storage and bubble formation during application and curing caused by carbon dioxide gas generation. Simultaneously, this step ensures the precise reaction of isocyanate with polyols to generate the target polyurethane prepolymer, avoiding ineffective raw material consumption and the formation of unstable urea bonds. This lays the foundation for obtaining a final product with excellent storage stability and uniform performance.

[0043] According to the preparation method of the odorless and environmentally friendly single-component polyurethane waterproof coating of the present invention, after adding the carbon dioxide absorbent, the reaction is continued with stirring for 0.5 to 1 hour. This ensures that the carbon dioxide absorbent is fully and uniformly dispersed throughout the high-viscosity prepolymer system, thereby capturing residual trace moisture and carbon dioxide gas that may be generated during subsequent storage or moisture curing without any dead zones.

[0044] According to the preparation method of the odorless and environmentally friendly single-component polyurethane waterproof coating of the present invention, after adding the remaining portion of the catalyst and the stabilizer, the mixture is stirred for 0.5 to 1 hour. This ensures that the stabilizer and catalyst are thoroughly and uniformly dispersed in the high-viscosity prepolymer system.

[0045] The beneficial effects of this invention are: The odorless, environmentally friendly, single-component polyurethane waterproof coating provided by this invention does not use conventional latent curing agents, fundamentally eliminating the release of irritating odorous substances such as aldehydes during the curing process, achieving a truly odorless product with extremely low VOC emissions. Simultaneously, this invention innovatively employs a combination of chelated tin catalyst, stabilizer, carbon dioxide absorbent, and a specific polyol. The synergistic effect of these components not only solves the technical pain points of poor storage stability and short shelf life in traditional products, resulting in minimal viscosity increase after heat storage, but also effectively avoids blistering during application. The resulting waterproof coating possesses excellent environmental friendliness, long shelf life, good workability, and superior mechanical properties such as high tensile strength, high elongation at break, and strong adhesive strength. Detailed Implementation

[0046] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this invention, not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0047] The raw materials used in the following examples and comparative examples are sourced from the following sources: Polyether diols: DL-2000D, purchased from Shandong Lanxing Dongda Co., Ltd., with a functionality of 2 and a number-average molecular weight of 2000; DL-1000D, purchased from Shandong Lanxing Dongda Co., Ltd., with a functionality of 2 and a number-average molecular weight of 1000.

[0048] Polyether triols: EP330N, purchased from Shandong Lanxing Dongda Co., Ltd., with a functionality of 3 and a number-average molecular weight of 5000; MN1000, purchased from Shandong Lanxing Dongda Co., Ltd., with a functionality of 3 and a number-average molecular weight of 1000.

[0049] Polytetrahydrofuran diols: PTMG-2000, purchased from Guangzhou Zhanhong Trading Co., Ltd., with a functionality of 2 and a molecular weight of 2000; PTMG1000, purchased from Guangzhou Zhanhong Trading Co., Ltd., with a functionality of 2 and a molecular weight of 1000.

[0050] The catalyst, octanoyl acetone tin, was purchased from Shanghai Maclean Biochemical Technology Co., Ltd.

[0051] The molecular sieve was purchased from Jiangxi Xintao Technology Co., Ltd., and its model is 5A molecular sieve activated powder.

[0052] All other raw materials not specifically mentioned are ordinary commercially available products.

[0053] The preparation method of the single-component polyurethane waterproof coating in the following embodiments includes the following steps: (1) Add polyether diol, polyether triol, polytetrahydrofuran polyol, small molecule chain extender, plasticizer, talc powder and heavy calcium carbonate to a strong disperser and disperse evenly.

[0054] (2) Transfer the dispersed slurry to the reactor, stir and heat to 100-110℃, and dehydrate for 2-3 hours under a relative vacuum of -0.08--0.1MPa.

[0055] (3) Lower the temperature to 70-80℃, then gradually add diisocyanate, stir, then add 1 / 4 to 1 / 2 of the formulation amount of catalyst, raise the temperature to 75-85℃, and react for 2-3 hours.

[0056] (4) Keep the temperature at 75-85℃, add carbon dioxide absorbent, and continue stirring for 0.5-1 hour.

[0057] (5) Cool down to 55-65°C, add the remaining amount of catalyst and stabilizer, and stir for 0.5-1 hour.

[0058] (6) Cool down to below 55°C, purge with nitrogen for protection, and discharge.

[0059] Example 1 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating, prepared from the following raw materials: DL-2000D 100 parts by weight; PTMG-2000 23 parts by weight; 0.6 parts by weight of 1,4-Butanediol; EP330N 58 parts by weight; 145 parts by weight of acetylacetonate tributyl citrate; 150 parts by weight of talc powder; 105 parts by weight of triple calcium carbonate; 40.5 parts by weight of TDI; 1.2 parts by weight of molecular sieve; Benzoyl chloride 0.1 parts by weight; 0.8 parts by weight of octanoyl acetone tin.

[0060] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, including the following steps: (1) Add polyether polyol DL-2000D, PTMG-2000, EP330N, 1,4-butanediol, plasticizer acetylic acid tributyl ester, talc powder and heavy calcium carbonate to a strong disperser and disperse evenly.

[0061] (2) Transfer the dispersed slurry to the reactor, stir and heat to 110°C, and dehydrate for 3 hours under a relative vacuum of -0.09MPa.

[0062] (3) Lower the temperature to 75°C, then gradually add diisocyanate TDI, stir, then add 1 / 3 of the formulation amount of catalyst, raise the temperature to 80°C, and react for 2 hours.

[0063] (4) Keep the temperature at 80°C, add molecular sieve, and continue stirring for 1 hour.

[0064] (5) Cool down to 60°C, add the remaining amount of catalyst and benzoyl chloride, and stir for 0.5 hours.

[0065] (6) Cool down to below 55°C, purge with nitrogen for protection, and discharge.

[0066] Example 2 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating, prepared from the following raw materials: DL-2000D 80 parts by weight; PTMG2000 43 parts by weight; 0.6 parts by weight of 1,4-Butanediol; EP330N 58 parts by weight; 145 parts by weight of acetylacetonate tributyl citrate; 150 parts by weight of talc powder; 105 parts by weight of triple calcium carbonate; 40.5 parts by weight of TDI; 1.2 parts by weight of molecular sieve; Benzoyl chloride 0.1 parts by weight; 0.8 parts by weight of octanoyl acetone tin.

[0067] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, including the following steps: (1) Add polyether polyol DL-2000D, PTMG-2000, EP330N, 1,4-butanediol, plasticizer acetylic acid tributyl ester, talc powder and heavy calcium carbonate to a strong disperser and disperse evenly.

[0068] (2) Transfer the dispersed slurry to the reactor, stir and heat to 110°C, and dehydrate for 3 hours under a relative vacuum of -0.09MPa.

[0069] (3) Lower the temperature to 75°C, then gradually add diisocyanate TDI, stir, then add 1 / 3 of the formulation amount of catalyst, raise the temperature to 80°C, and react for 2 hours.

[0070] (4) Keep the temperature at 80°C, add molecular sieve, and continue stirring for 1 hour.

[0071] (5) Cool down to 60°C, add the remaining amount of catalyst and benzoyl chloride, and stir for 0.5 hours.

[0072] (6) Cool down to below 55°C, purge with nitrogen for protection, and discharge.

[0073] Example 3 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating, prepared from the following raw materials: DL-2000D 80 parts by weight; PTMG2000 23 parts by weight; 0.6 parts by weight of 1,4-Butanediol; EP330N 78 parts by weight; 145 parts by weight of acetylacetonate tributyl citrate; 150 parts by weight of talc powder; 105 parts by weight of triple calcium carbonate; 40.5 parts by weight of TDI; 1.2 parts by weight of molecular sieve; Benzoyl chloride 0.1 parts by weight; 0.8 parts by weight of octanoyl acetone tin.

[0074] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, including the following steps: (1) Add polyether polyol DL-2000D, PTMG-2000, EP330N, 1,4-butanediol, plasticizer acetylic acid tributyl ester, talc powder and heavy calcium carbonate to a strong disperser and disperse evenly.

[0075] (2) Transfer the dispersed slurry to the reactor, stir and heat to 110°C, and dehydrate for 3 hours under a relative vacuum of -0.09MPa.

[0076] (3) Lower the temperature to 75°C, then gradually add diisocyanate TDI, stir, then add 1 / 3 of the formulation amount of catalyst, raise the temperature to 80°C, and react for 2 hours.

[0077] (4) Keep the temperature at 80°C, add molecular sieve, and continue stirring for 1 hour.

[0078] (5) Cool down to 60°C, add the remaining amount of catalyst and benzoyl chloride, and stir for 0.5 hours.

[0079] (6) Cool down to below 55°C, purge with nitrogen for protection, and discharge.

[0080] Example 4 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Example 1 is that the amount of PTMG2000 is 60 parts.

[0081] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0082] Example 5 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Embodiment 1 is that an equal amount of PTMG1000 is used instead of PTMG2000.

[0083] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0084] Example 6 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Example 1 is that an equal amount of DL-1000D is used instead of DL-2000D.

[0085] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0086] Example 7 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Example 1 is that an equal amount of MN1000 is used instead of EP330N.

[0087] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0088] Example 8 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Example 1 is that the 1,4-butanediol content is 0.5 parts.

[0089] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0090] Example 9 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and Example 1 is that 1,4-butanediol is 1 part.

[0091] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0092] Example 10 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Example 1 is that the amount of 1,4-butanediol is 1.5 parts.

[0093] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0094] Example 11 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Example 1 is that the benzoyl chloride content is 0.2 parts.

[0095] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0096] Example 12 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Example 1 is that the benzoyl chloride content is 0.3 parts.

[0097] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0098] Example 13 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Example 1 is that acetic anhydride is used instead of an equal amount of benzoyl chloride.

[0099] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0100] Example 14 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and Example 1 is that vinyltrimethoxysilane is used instead of an equal amount of benzoyl chloride.

[0101] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0102] Example 15 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and Example 1 is that p-toluenesulfonyl chloride is used instead of an equal amount of benzoyl chloride.

[0103] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0104] Example 16 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Example 1 is that the octanoyl acetone tin content is 0.5 parts.

[0105] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0106] Example 17 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Example 1 is that the octanoyl acetone tin is 1.0 part.

[0107] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0108] Example 18 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and Example 1 is that it uses an equal amount of tin acetylacetone instead of tin octanoyl acetylacetone.

[0109] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0110] Example 19 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Example 1 is that the molecular sieve is 1 part.

[0111] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0112] Example 20 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Example 1 is that the molecular sieve is 2 parts.

[0113] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0114] Example 21 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Example 1 is that the molecular sieve is 5 parts.

[0115] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0116] Example 22 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and the one in Example 1 is that the molecular sieve is 8 parts.

[0117] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0118] Example 23 This embodiment provides an odorless, environmentally friendly, single-component polyurethane waterproof coating. The only difference between this coating and Example 1 is that it uses an equal amount of diatomaceous earth (manufactured by Hebei Huishun Mining Co., Ltd., 600 mesh) instead of molecular sieve.

[0119] This embodiment also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0120] Comparative Example 1 This comparative example provides a single-component polyurethane waterproof coating, which differs from Example 1 in that PTMG2000 is replaced with an equal amount of DL-2000D.

[0121] This comparative example also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0122] Comparative Example 2 This comparative example provides a single-component polyurethane waterproof coating, which differs from Example 1 in that the molecular sieve in Example 1 is removed.

[0123] This comparative example also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0124] Comparative Example 3 This comparative example provides a one-component polyurethane waterproof coating, which differs from Example 1 in that: the octanoyl acetone tin in Example 1 is replaced in equal amounts with the conventional organotin catalyst dibutyltin disilicate.

[0125] This comparative example also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0126] Comparative Example 4 This comparative example provides a one-component polyurethane waterproof coating, which differs from Example 1 in that benzoyl chloride is removed from Example 1.

[0127] Comparative Example 5 This comparative example provides a single-component polyurethane waterproof coating, which differs from Example 1 in that the amount of PTMG2000 used is 65 parts by weight.

[0128] This comparative example also provides a method for preparing the single-component polyurethane waterproof coating, which is the same as in Example 1.

[0129] The performance of the single-component polyurethane waterproof coatings prepared in Examples 1 to 23 and Comparative Examples 1 to 5 was tested. The test methods were in accordance with the standards GB / T19250-2013 and GB / T16777-2008. The test performance is shown in Tables 1 to 3.

[0130] Test method: Construction odor: Apply 200g of paint sample to a 30cm*50cm glass plate, then transfer it to a sealed fume hood for curing. After curing for 24 hours at a temperature of (23±2)℃ and a humidity of (50±10)%, open the fume hood and smell the air inside.

[0131] Surface drying time, complete drying time, tensile strength, elongation at break, tear strength, bond strength, and volatile organic compound content shall be determined in accordance with GB / T19250-2013.

[0132] The foaming property test for thick coatings shall be conducted in accordance with section 7.14 of JC / T2435-2018.

[0133] Storage stability test method: After the sample is placed under standard test conditions (23±2℃, relative humidity 50±10%) for 24 hours, the initial viscosity of the sample is measured. Then, the sample is placed in a 50℃ forced-air drying oven for accelerated thermal storage. After the predetermined time, the sample is removed and placed under standard test conditions for 24 hours, and the viscosity after thermal storage is measured. Viscosity increase value = (viscosity after thermal storage - initial viscosity) * 100% / initial viscosity.

[0134] Table 1 project Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Viscosity 9300 10100 10800 14800 8100 8900 9000 9200 9700 10300 9200 9350 Viscosity increase value / % (heat storage 30 days) 2 3 2 9 3 2 3 2 4 5 2 2 Construction odor Odorless Odorless Odorless Odorless Odorless Odorless Odorless Odorless Odorless Odorless Odorless Odorless Foaming properties of thick coating (50℃, 80% humidity) No foaming No foaming No foaming No foaming No foaming No foaming No foaming No foaming No foaming No foaming No foaming No foaming Volatile organic compound content / g / L (VOC) 5 5 6 4 4 5 4 6 5 4 5 6 Surface drying time / h 3 3 3 4 3 3.5 3 3 3 3 4 5 Practical time / h 6 6 6 8 6 7 6 6 5 5 9 10 Tensile strength / MPa 3.01 3.22 3.07 4.36 3.52 3.13 3.08 2.89 3.09 3.15 2.78 2.51 Elongation at break / % 778 662 712 871 621 652 579 793 756 713 834 892 Tear strength (N / mm) 17 19 17 15 18 18 18 17 18 18 16 16 Bond strength / MPa 1.20 1.31 1.22 1.64 1.43 1.24 1.21 1.18 1.21 1.23 1.12 1.04 Table 2 project Example 13 Example 14 Example 15 Example 16 Example 17 Example 18 Example 19 Example 20 Example 21 Example 22 Example 23 Viscosity 9200 9700 9310 9000 9500 9400 9300 9430 9600 9800 9100 Viscosity increase value / % (heat storage 30 days) 2 2 2 4 3 2 2 3 5 7 6 Construction odor Odorless Odorless Odorless Odorless Odorless Odorless Odorless Odorless Odorless Odorless Odorless Foaming properties of thick coating (50℃, 80% humidity) No foaming No foaming No foaming No foaming No foaming No foaming No foaming No foaming No foaming No foaming No foaming Volatile organic compound content / g / L (VOC) 5 5 5 6 5 5 5 4 4 3 8 Surface drying time / h 3 3 3 4 3 3 3 3 3 3 3 Practical time / h 6 6 6 8 6 6 6 6 6 6 6 Tensile strength / MPa 3.03 2.33 2.83 2.53 3.15 3.04 2.91 2.86 2.73 2.65 2.93 Elongation at break / % 758 898 718 875 708 771 793 817 831 846 798 Tear strength (N / mm) 17 15 17 16 17 17 17 17 17 17 17 Bond strength / MPa 1.21 1.08 1.05 1.02 1.26 1.14 1.17 1.15 1.12 1.08 1.16 Table 3 project Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Comparative Example 5 Viscosity 8800 9000 11000 9200 16800 Viscosity increase value / % (heat storage 30 days) 3 12 Solidified 38 21 Construction odor Odorless Odorless Odorless Odorless Odorless Foaming properties of thick coating (50℃, 80% humidity) No foaming Slight bubbling Slight bubbling No foaming No foaming Volatile organic compound content / g / L (VOC) 7 13 15 4 3 Surface drying time / h 4 5 4 3.5 3 Practical time / h 8 9 8 7 6 Tensile strength / MPa 2.54 2.86 2.95 2.93 4.04 Elongation at break / % 880 723 651 640 467 Tear strength (N / mm) 12 17 17 17 22 Bond strength / MPa 0.81 1.06 1.02 1.17 1.57 As can be seen from the comparison in the table above, the single-component polyurethane waterproof coatings of Examples 1-23 limit the raw materials and dosages of components such as polyether, PTMG, chain extender, and stabilizer within a specific range, which can produce a synergistic effect. The resulting single-component polyurethane waterproof coatings have no abnormalities in various aspects, low volatile organic compound content / g / L (VOC) value, no odor during construction, no blistering when applied thickly, and no significant change in viscosity increase after heat storage.

[0135] The comparison between Example 1 and Comparative Example 1 shows that replacing PTMG2000 in Example 1 with an equal amount of DL-2000D has a significant impact on tear performance and bond strength, resulting in unsatisfactory tear strength and bond strength. Furthermore, Example 1 performs better in terms of tensile strength, drying time, storage stability (lower viscosity growth rate after 30 days of heat storage), and VOC content.

[0136] The comparison between Example 1 and Comparative Example 2 shows that molecular sieves are crucial for preventing coating blistering, reducing VOCs, improving storage stability, and ensuring excellent mechanical properties. Comparative Example 2, which omitted molecular sieves, exhibited slight blistering during thick coating application and had a relatively high VOC content, indicating that the molecular sieves can absorb carbon dioxide gas released during coating curing. Furthermore, compared to Example 1, Comparative Example 2 showed a viscosity increase of up to 12%, indicating significantly worse storage stability. Comparative Example 2 also had a longer drying time, and key mechanical properties such as tensile strength, elongation at break, and bond strength all decreased to varying degrees.

[0137] A comparison of Example 1 and Comparative Example 3 shows that, compared to Example 1 which used a chelated tin catalyst (tin octanoyl acetone), Comparative Example 3, which replaced the catalyst with a conventional organotin catalyst (dibutyltin dimethyl tin silicate), exhibited extremely poor storage stability, completely curing after 30 days of heat storage, and exhibiting slight bubbling during thick coating application. In contrast, Example 1 showed a viscosity increase of only 2% after heat storage, with no bubbling observed during thick coating application. This clearly demonstrates that the chelated tin catalyst used in this invention is key to achieving excellent storage stability and good application performance.

[0138] A comparison of Example 1 and Comparative Example 4 shows that Comparative Example 4, which removed the stabilizer (benzoyl chloride) from the formulation of Example 1, exhibited a viscosity increase of 38% after 30 days of heat storage, significantly higher than the 2% increase in Example 1. This substantial viscosity increase after heat storage indicates a significant decrease in its storage stability. This result demonstrates that the stabilizer in this invention is beneficial in suppressing viscosity growth in coatings during storage and ensuring long-term product storage stability.

[0139] A comparison between Example 1 and Comparative Example 5 shows that the amount of polytetrahydrofuran polyol (PTMG2000) in Comparative Example 5 exceeded the limits specified in this invention, resulting in excessively high initial viscosity of the product and reduced ease of application; simultaneously, the elongation at break of the product also decreased significantly. This indicates that controlling the amount of each component within the specific range required by the invention is a necessary condition for achieving a balance between good workability and excellent mechanical properties of the product.

[0140] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An odorless, environmentally friendly, single-component polyurethane waterproof coating, characterized in that, Its preparation materials do not include latent curing agents, and include the following raw material components: 140-245 parts by weight of polyether polyol; 0.5~1.5 parts by weight of small molecule chain extender; 38-42 parts by weight of diisocyanate; Stabilizer 0.1~0.3 parts by weight; Carbon dioxide absorbent: 1.0~8.0 parts by weight; Catalyst: 0.5~1.0 parts by weight; The catalyst is a chelated tin catalyst; the chelated tin catalyst is tin acetylacetonate; the stabilizer is one or more of benzoyl chloride, p-toluenesulfonyl chloride, acid anhydride, and vinyltrimethoxysilane; the carbon dioxide absorbent is selected from molecular sieves; the molecular sieve includes one or more of type A molecular sieves, type X molecular sieves, and type Y molecular sieves; the pore size of the molecular sieve is 0.5-1.0 nm, and the specific surface area is 500-1000 m². 2 / g; The polyether polyol includes polytetrahydrofuran polyol, which is 20-60 parts by weight; the polyether polyol also includes non-polytetrahydrofuran polyols: 75-100 parts by weight of polyether diol and 45-85 parts by weight of polyether triol; the polyether diol has a number average molecular weight of 1000-2000, a functionality of 2, and a hydroxyl value of 56.1-112.2 mgKOH / g; the polyether triol has a number average molecular weight of 1000-5000, a functionality of 3, and a hydroxyl value of 33.66-56.1 mgKOH / g.

2. The odorless, environmentally friendly, single-component polyurethane waterproof coating according to claim 1, characterized in that, The stabilizer is benzoyl chloride.

3. The odorless, environmentally friendly, single-component polyurethane waterproof coating according to claim 1, characterized in that, The polytetrahydrofuran polyol is a polytetrahydrofuran diol.

4. The odorless, environmentally friendly, single-component polyurethane waterproof coating according to claim 3, characterized in that, The number-average molecular weight of the polytetrahydrofuran diol is 1000-2000.

5. The odorless, environmentally friendly, single-component polyurethane waterproof coating according to claim 1, characterized in that, The small molecule chain extender is selected from one or more of diamine chain extenders or diol chain extenders; the diamine chain extender includes one or more of isophorone diamine, ethylenediamine, dimethylthiotoluene diamine, and diethyltoluene diamine; the diol chain extender includes one or more of 1,4-butanediol, 1,6-hexanediol, diethylene glycol, and 1,4-cyclohexanediol.

6. The odorless, environmentally friendly, single-component polyurethane waterproof coating according to claim 1, characterized in that, The raw materials for its preparation also include the following raw material components: 150-260 parts by weight of pigments and fillers; the pigments and fillers are selected from one or more of nano-calcium carbonate, talc powder, fumed silica, heavy calcium carbonate, kaolin, wollastonite powder, mica powder, titanium dioxide and carbon black; And / or, the diisocyanate is selected from one or more of toluene diisocyanate, diphenylmethane diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate.

7. The odorless, environmentally friendly, single-component polyurethane waterproof coating according to claim 1, characterized in that, The raw materials used in its preparation also include the following components: 100-150 parts by weight of plasticizer.

8. The odorless, environmentally friendly, single-component polyurethane waterproof coating according to claim 7, characterized in that, The plasticizer is selected from one or more of vegetable oil esters, trioctyl phosphate, citrate, tributyl acetylcitrate, and chlorinated paraffin plasticizers.

9. The method for preparing the odorless, environmentally friendly, single-component polyurethane waterproof coating according to any one of claims 1-8, characterized in that, Includes the following steps: Polyether polyol, small molecule chain extender and pigments and fillers are mixed to obtain a mixed slurry; Diisocyanate and part of the catalyst are added to the mixed slurry at 70-80°C, the temperature is raised to 75-85°C, and the reaction is carried out for 2-3 hours; then carbon dioxide absorbent is added at 75-85°C, and the reaction is continued with stirring; then the temperature is lowered to 55-65°C, and the remaining catalyst and stabilizer are added.

10. The preparation method of the odorless, environmentally friendly, single-component polyurethane waterproof coating according to claim 9, characterized in that, The mixed slurry is dehydrated before the diisocyanate and part of the catalyst are added; And / or, after adding the carbon dioxide absorbent, continue stirring the reaction for 0.5 to 1 hour; And / or, after adding the remaining portion of the catalyst and the stabilizer, stir for 0.5 to 1 hour.

11. The preparation method of the odorless, environmentally friendly, single-component polyurethane waterproof coating according to claim 10, characterized in that, The dehydration is carried out at a temperature of 100-110℃ and a relative vacuum of -0.08--0.1MPa for 2-3 hours.