Preparation method of single-component moisture-cured polyurethane sealant

Abstract

The invention relates to the field of high polymer materials, in particular to a preparation method of a single-component moisture-cured polyurethane sealant, which comprises the following steps: synthesis of a hydroxyl-terminated siloxane chain extender (BK), synthesis of a polyurethane (PU) prepolymer, synthesis of side-chain silane modified polyurethane resin, synthesis of a side-chain silane modified polyurethane resin, and preparation of the single-component moisture-cured polyurethane sealant. Finally, SPU-BK, a green plasticizer, carbon black, nano calcium carbonate, p-toluenesulfonyl isocyanate, an ultraviolet light absorber, an anti-aging agent, a coupling agent and dimorpholinyl diethyl ether are mixed, and the sealant is obtained.The prepared side chain silane modified polyurethane has excellent hydrophobicity, mechanical property and curing efficiency; the requirements on high-performance polyurethane materials in the fields of coatings, adhesives and the like can be met.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, specifically to a method for preparing a single-component moisture-curing polyurethane sealant. Background Technology

[0002] In the field of polymer materials, polyurethane (PU) is widely used in coatings, adhesives, elastomers, and foam materials due to its excellent mechanical properties and flexible tunability. However, with increasingly complex application environments, improving the aging resistance of polyurethane materials has become a key technical challenge that urgently needs to be solved. Since organosilicon materials have excellent aging resistance, their use in modification can effectively adjust the overall performance of polyurethane, and therefore has become a research hotspot in recent years.

[0003] Currently, physical blending interpenetrating polymer network (IPN) modification, silane end-capping modification, and block siloxane segment insertion modification are all effective strategies for preparing silicone-modified polyurethanes. Silane-modified polyurethanes are the most widely used because they combine the basic properties of polyurethane with the excellent water resistance and chemical resistance imparted by silane. They can change the curing mechanism of polyurethane by initiating curing and crosslinking through siloxane hydrolysis, thus avoiding bubble formation. However, this technology has significant drawbacks, such as decreased mechanical properties and poor controllability over silicone content. Summary of the Invention

[0004] In view of the above situation and to overcome the defects of the prior art, the purpose of this invention is to provide a method for preparing a single-component moisture-curing polyurethane sealant.

[0005] The technical solution provided by this invention is a method for preparing a single-component moisture-curing polyurethane sealant, comprising the following steps:

[0006] 1. Synthesis of hydroxyl-terminated siloxane chain extender (BK):

[0007] First, 1,4-butanediol diglycidyl ether (BDG) and KH-590 were added to a flask at a molar ratio of 1:2. Then, triethylamine (TEA) at 1% (by weight of KH-590) was added as a catalyst. The reaction was heated at 60°C for 3 hours to obtain the product, a terminal hydroxyl siloxane chain extender (BK). The reaction process was monitored using Fourier transform infrared spectroscopy (FT-IR), and the product was characterized by ¹H NMR spectroscopy. The NMR characterization data are as follows: ¹H NMR (400... MHz, DMSO-d6) δ4.89–4.81 (m, 2H), 3.77–3.57 (m, 2H), 3.47 (s, 18H), 3.40–3.36 (m, 4H), 3.33 (m, 4H), 2.56–2.44 (m, 8H), 1.61–1.51 (m, 8H), 0.71–0.64 (m, 4H);

[0008] 2. Weigh the measured amount of polyol and place it in a four-necked flask. Heat it to 110°C using a heating mantle, then dehydrate it using a rotary vane vacuum pump for 1.5 hours. Cool the polyol to 80°C, add isocyanate at 80°C according to a ratio of R=2.4 (the ratio of -NCO groups to -OH groups), and add 0.1% of dibutyltin dilaurate (DBTDL) as a catalyst. React under nitrogen (N2) protection for 3 hours to obtain polyurethane (PU) prepolymer.

[0009] 3. Under a nitrogen (N2) atmosphere, add a hydroxyl-terminated siloxane chain extender (BK) to the polyurethane (PU) prepolymer prepared above, followed by adding 0.1% of dibutyltin dilaurate (DBTDL) by mass, and react at 80°C for 3 hours to obtain a side-chain silane modified polyurethane resin (i.e., SPU-BK resin).

[0010] 4. First, dry nano-calcium carbonate and carbon black at 110℃ in a forced-air drying oven for 48 hours, then keep them dry and cooled for later use. Add side-chain silane-modified polyurethane resin SPU-BK, green plasticizer, carbon black, and nano-calcium carbonate to a double planetary mixer in sequence. Under argon protection, maintain the temperature below 45℃ and stir at high speed for 25-35 minutes. Add coupling agent, p-toluenesulfonyl isocyanate (PTSI), ultraviolet absorber, and anti-aging agent to the mixer in sequence, and continue stirring at high speed for 10-15 minutes under argon protection and below 45℃. Add bismorpholino diethyl ether (DMDEE) to the mixer and stir at high speed for 10-15 minutes under nitrogen protection and below 45℃. Then, perform vacuum degassing treatment to obtain the sealant.

[0011] In step 3, the molar ratio of the terminal hydroxyl siloxane chain extender (BK) to the polytetrahydrofuran diol (PTMEG) and isophorone diisocyanate (IPDI) in step 2 is 0.0042~0.021:0.03:0.072;

[0012] In step 4, the weight ratio of SPU-BK, green plasticizer, carbon black, nano calcium carbonate, p-toluenesulfonyl isocyanate, ultraviolet absorber, anti-aging agent, coupling agent, and bismorpholino diethyl ether is 25-40:10-23:23-25:22.5-26.5:0.5:0.5:0.5:1.2:0.2.

[0013] The polyol is polytetrahydrofuran diol with a molecular weight of 1000–3000 g / mol.

[0014] The isocyanate is a benzene-free isocyanate, including one or more of cycloisophorone diisocyanate (IPDI), hexane-1,4-diisocyanate (CHDI), and 4,4'-dicyclohexylmethane diisocyanate.

[0015] The coupling agent is one or more of γ-glycidoxypropyltrimethoxysilane (KH-560), γ-glycidoxypropyltriethoxysilane (KH-561), and β-(3,4-epoxycyclohexyl)ethyltrimethoxysilane (KH-562).

[0016] The plasticizer is a cyclohexane polyacid derivative, specifically one or more of dioctyl cyclohexane 1,2-dicarboxylate (DEHCH), diisononyl cyclohexane 1,2-dicarboxylate (DINCH), and di(2-propylheptyl) cyclohexane 1,2-carboxylate (DPHCH).

[0017] The anti-aging agent is one or both of pentaerythritol tetrakis[β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate] and octadecyl β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate.

[0018] The ultraviolet light absorber is one or both of (2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole) (UV-237) and (2-(2'-hydroxy-5'-methylphenyl)benzotriazole) (UV-P).

[0019] This invention proposes an innovative scheme centered on "novel chain extender design and side-chain modification regulation." On one hand, it utilizes the Michael addition reaction between thiols and epoxy groups, using highly reactive 1,4-butanediol diglycidyl ether (BDG) as the backbone and γ-mercaptopropyltrimethoxysilane (KH-590), which improves interfacial compatibility, as the silicon source, to prepare a novel hydroxyl-terminated siloxane chain extender via a ring-opening reaction catalyzed by triethylamine. This synthetic route features mild reaction conditions, enabling the siloxane groups to be directionally introduced into the chain extender molecule, ensuring controllable product structure. On the other hand, by adjusting the reaction ratio between this chain extender and a polyurethane prepolymer synthesized from polytetrahydrofurandiol (PTMEG) and isophorone diisocyanate (IPDI), siloxane groups are directionally grafted onto the polyurethane side chains. This modification strategy avoids the problem of poor silicon content controllability in traditional siloxane end-capping modification, providing a new approach for precise structure-property regulation of side-chain silane-modified polyurethanes. The prepared side-chain silane-modified polyurethane has excellent hydrophobicity, mechanical properties and curing efficiency, which can meet the needs of coatings, adhesives and other fields for high-performance polyurethane materials.

[0020] The method of this invention is scientific and reasonable, uses abundant raw materials, is pollution-free, and is easy to produce. The entire preparation process is easy to operate, fully demonstrating its environmental friendliness. It provides solid and powerful technical support for the sustainable development of the sealant industry and has good application prospects. It is an innovation in the preparation method of single-component moisture-curing polyurethane sealant, with significant economic and social benefits. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the synthesis mechanism of the terminal hydroxyl siloxane chain extender (BK) of the present invention;

[0022] Figure 2 This is a schematic diagram of the synthesis mechanism of the side-chain silane-modified polyurethane resin (i.e., SPU-BK resin) of the present invention.

[0023] Figure 3 Thermogravimetric analysis (TGA) curves of elastomers SPU-BK0, SPU-BK30, and SPU-BK50;

[0024] Figure 4 Derivative thermogravimetric analysis (DTG) curves of elastomers SPU-BK0, SPU-BK30, and SPU-BK50;

[0025] Figure 5 DSC curve of elastomer SPU-BK;

[0026] Figure 6 XRD curve of elastomer SPU-BK;

[0027] Figure 7Static water contact angle and water absorption rate of elastomer SPU-BK;

[0028] Figure 8 Static water contact angle image of SPU-BK elastomer;

[0029] Figure 9 Weight loss rate of elastomer SPU-BK after immersion in different solutions for 48 hours;

[0030] Figure 10 Viscosity data chart of SPU-SK elastomer resin;

[0031] Figure 11 Hardness data chart of elastomer SPU-SK;

[0032] SPU-BK0 refers to the resin prepared when the amount of terminal hydroxyl siloxane chain extender (BK) added is 0. It is prepared for the purpose of obtaining test data for graphing and is not within the scope of protection of the method in this application. Detailed Implementation

[0033] The specific implementation of the present invention will be described in detail below with reference to examples and specific circumstances.

[0034] Example 1:

[0035] A method for preparing a one-component moisture-curing polyurethane sealant includes the following steps:

[0036] 1. Synthesis of hydroxyl-terminated siloxane chain extender (BK):

[0037] First, 1,4-butanediol diglycidyl ether (BDG) and KH-590 were added to a flask at a molar ratio of 1:2, followed by the addition of 1% triethylamine (TEA) as a catalyst (based on the mass of KH-590). The reaction was heated at 60°C for 3 hours to obtain the product, a terminal hydroxyl siloxane chain extender (BK). The reaction process was monitored using Fourier transform infrared spectroscopy (FT-IR), and the product was characterized by ¹H NMR spectroscopy. The NMR characterization data are as follows: ¹H NMR (400 MHz, DMSO-d6) δ4.89–4.81 (m, 2H), 3.77–3.57 (m, 2H), 3.47 (s, 18H), 3.40–3.36 (m, 4H), 3.33 (m, 4H), 2.56–2.44 (m, 8H), 1.61–1.51 (m, 8H), 0.71–0.64 (m, 4H);

[0038] 2. Weigh 0.03 mol of polytetrahydrofuran diol (PTMEG, number average molecular weight of 2000 g / mol) and place it in a four-necked flask. Heat it to 110°C using a heating mantle, then dehydrate it for 1.5 hours using a rotary vane vacuum pump. Cool the polytetrahydrofuran diol (PTMEG) to 80°C, add 0.072 mol of isophorone diisocyanate (IPDI) at 80°C, and add 0.1% of dibutyltin dilaurate (DBTDL) as a catalyst. React under nitrogen (N2) protection for 3 hours to obtain polyurethane (PU) prepolymer.

[0039] 3. Under a nitrogen (N2) atmosphere, 0.0210 mol of terminal hydroxyl siloxane chain extender (BK) was added to the polyurethane (PU) prepolymer prepared above, followed by the addition of 0.1% of dibutyltin dilaurate (DBTDL) by mass, and the reaction was carried out at 80°C for 3 hours to obtain side-chain silane modified polyurethane resin (i.e., SPU-BK50 resin).

[0040] 4. First, dry the nano-calcium carbonate and carbon black in a forced-air drying oven at 110℃ for 48 hours, keeping them dry and cooled for later use. Then, modify the side-chain silane-modified polyurethane resin (SPU-BK50) and the green plasticizer (cyclohexane 1, ... Dioctyl 2-dicarboxylate, carbon black, and nano-calcium carbonate are sequentially added to a dual planetary mixer. Under argon protection, the mixture is stirred at high speed at a temperature below 45°C for 25–35 minutes. Coupling agent (KH-560), p-toluenesulfonyl isocyanate (PTSI), UV absorber (2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole), and anti-aging agent (β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate) are added sequentially to the mixer. The mixture is then stirred at high speed for 10–15 minutes under argon protection and at a temperature below 45°C. Finally, dimorpholino diethyl ether (DMDEE) is added to the mixer, and the mixture is stirred at high speed for 10–15 minutes under nitrogen protection and at a temperature below 45°C. Vacuum degassing is then performed to obtain the sealant.

[0041] Among them are SPU-50, green plasticizer (dioctyl cyclohexane 1,2-dicarboxylate), carbon black, nano-calcium carbonate, and p-toluene.

[0042] The weight ratios of sulfonyl isocyanate, ultraviolet absorber (2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole), anti-aging agent (β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol ester), coupling agent (KH-560), and bismorpholino diethyl ether were 25:23:23:26.5:0.5:0.5:0.5:1.2:0.2, respectively.

[0043] Example 2: The difference between this example and Example 1 is that the amount of BK added is 0.0168 mol.

[0044] Example 3: The difference between this example and Example 1 is that the amount of BK added is 0.0126 mol.

[0045] Example 4: The difference between this example and Example 1 is that the amount of BK added is 0.0084 mol.

[0046] Example 5: The difference between this example and Example 1 is that the amount of BK added is 0.0042 mol.

[0047] Example 6: This example differs from Example 3 in that the quantities of SPU-30, green plasticizer, carbon black, nano calcium carbonate, p-toluenesulfonyl isocyanate, ultraviolet absorber, anti-aging agent, coupling agent, and bismorpholino diethyl ether are different.

[0048] The ratios are 30:18:23.5:26:0.5:0.5:0.5:1.2:0.2.

[0049] Example 7: This example differs from Example 3 in that the quantities of SPU-30, green plasticizer, carbon black, nano calcium carbonate, p-toluenesulfonyl isocyanate, UV absorber, anti-aging agent, coupling agent, and bismorpholino diethyl ether are different.

[0050] The ratios are 35:13:24:25.5:0.5:0.5:0.5:1.2:0.2.

[0051] Example 8: This example differs from Example 3 in that the quantities of SPU-30, green plasticizer, carbon black, nano calcium carbonate, p-toluenesulfonyl isocyanate, ultraviolet absorber, anti-aging agent, coupling agent, and bismorpholino diethyl ether are different.

[0052] The ratios are 40:10:25:22.5:0.5:0.5:0.5:1.2:0.2.

[0053] The sealant prepared by the method of the present invention is a single-component moisture-curing type. The sealant prepared in Examples 3, 6, 7 and 8 is applied to a polytetrafluoroethylene (PTFE) mold plate, and the remainder is applied to the substrate with a scraper (the application size is 25 mm*12.5 mm*2 mm). Then, the PTFE mold plate and the substrate are cured at (23±2)℃ and (50±5)% relative humidity according to national standards and then tested.

[0054] Table 1: Test performance of sealants in Examples 3, 6, 7, and 8:

[0055]

[0056] This invention utilizes a novel hydroxyl-terminated siloxane chain extender to significantly improve the thermal stability of polyurethane. Thermogravimetric analysis (TGA) shows that with increasing chain extender content, the thermal initiation decomposition temperature of SPU-BK elastomer increases due to the high bond energy of Si-O bonds and the increased proportion of hard segments in the siloxane structure. This allows it to maintain stability over a wider temperature range, broadening its application range at high temperatures. The elastomer char content increased from 0.27% in SPU-BK10 to 4.97% in SPU-BK50 and is positively correlated with the amount of silane added, demonstrating that the siloxane group actively improves thermal stability. Differential thermogravimetric analysis (DTG) curves show that increasing the chain extender increases the proportion of hard segments in the polymer, raises the decomposition temperature, optimizes decomposition characteristics, precisely controls decomposition behavior at different temperature stages, and improves the reliability and stability of the material under complex temperature environments.

[0057] This invention employs a novel hydroxyl-terminated siloxane chain extender, significantly improving the properties of SPU-BK elastomer in terms of glass transition temperature and crystal structure. Differential scanning calorimetry (DSC) analysis shows that existing silane-free SPU-BK0 exhibits two glass transition temperatures (Tg) corresponding to soft and hard segments, while SPU-BK30 and SPU-BK50, after adding the chain extender in this invention, have only one Tg. This is because the chain extender homogenizes the polymer structure, reducing regional differences in thermal transition, thereby improving the material's performance stability at different temperatures and avoiding performance fluctuations caused by multiple Tg values. X-ray diffraction (XRD) analysis shows that existing SPU-BK0 exhibits unique peaks in its XRD pattern due to the crystallization of polytetrahydrofuran diol and isophorone diisocyanate. After adding the chain extender in this invention, the 10° peak disappears and the 20° shoulder peak changes, indicating that it disrupts the ordered structure of the prepolymer and inhibits soft segment crystallization. Simultaneously, the enhanced siloxane crosslinking network interacts with the soft segments, reducing crystallinity and optimizing the material's flexibility and plasticity.

[0058] This invention utilizes a novel hydroxyl-terminated siloxane chain extender to significantly improve the hydrophobicity of SPU-BK elastomer. Static water contact angle measurements show that the existing silane-free SPU-BK0 has a static water contact angle of 75°, while in this invention, as the content of the organosilicon chain extender increases, the water contact angle first increases from 75° to 108.1° for SPU-BK10. Although it then decreases slightly to 90.1°, it remains above 90°, indicating good hydrophobicity. The initial increase in contact angle is due to the improved surface hydrophobicity caused by low chain extender content; however, when the chain extender content reaches a certain level, its uneven distribution within the polyurethane chain or changes in intermolecular interactions lead to changes in surface properties, resulting in a decrease in the water contact angle. This characteristic allows for effective control of hydrophobicity within a certain range. Compared to existing technologies, it better meets the hydrophobicity requirements of different application scenarios. For example, in special environments requiring waterproofing but also some hydrophilicity, the material of this invention can achieve precise control of hydrophobic properties by adjusting the chain extender content, exhibiting superior adaptability.

[0059] This invention utilizes a novel hydroxyl-terminated siloxane chain extender to achieve a lower water absorption rate in SPU-BK elastomers. The water absorption rate of SPU-SK elastomer without organosilicon chain extenders is 1.58%, while the water absorption rate of SPU-BK0 elastomer with the novel hydroxyl-terminated siloxane chain extender decreases to 0.3%. As the organosilicon content continuously increases, the side-chain siloxanes hinder their migration to the surface, reducing surface siloxanes and weakening the water barrier effect, resulting in slightly higher water absorption than SPU-BK10 elastomer. This aligns with previous observations of these samples exhibiting lower water contact angles and weaker surface hydrophobicity. This invention effectively regulates the water absorption of SPU-BK elastomers by controlling the content of the organosilicon chain extender.

[0060] The SPU-BK elastomer prepared using a novel hydroxyl-terminated siloxane chain extender exhibits excellent resistance to acid, alkali, and salt solutions. The elastomer was immersed in 5% copper chloride (CuCl2) aqueous solution, 5% sodium hydroxide (NaOH) aqueous solution, and 5% sulfuric acid (H2SO4) solution for 48 hours, and the weight changes before and after immersion were compared. The SPU-BK elastomer exhibited a low weight loss rate in these solvents. This is because the SPU-BK elastomer formed by this invention possesses a denser network structure, which better blocks the intrusion of solvent molecules, thus demonstrating excellent solvent resistance.

[0061] This invention utilizes a novel hydroxyl-terminated siloxane chain extender to achieve adjustable viscosity of SPU-BK resin. Measured at 25°C, the viscosity of SPU-BK resin showed a continuous upward trend with increasing chain extender content, increasing from 3300 mPa·s to 12000 mPa·s. This effective viscosity control allows for precise control of material viscosity in practical applications, such as coatings and adhesives, by adjusting the chain extender content according to different construction process requirements. This improves the application performance and quality stability of the product, offering greater flexibility and practicality compared to existing technologies.

[0062] This invention exhibits a unique and positive impact on the hardness of SPU-SK elastomers. The hardness of SPU-SK elastomers after moisture curing of SPU-SK resin was studied. The results showed that the hardness of the silane-free SPU-BK0 sample was approximately 57 Shore A. With increasing chain extender content, the hardness of the SPU-SK elastomer gradually decreased. Although the crosslinking density in the molecular structure increased, the siloxane groups in the chain extender possessed a certain degree of flexibility, and their introduction weakened the rigidity of the polymer chain to some extent. Under the combined effect of these two factors, the material hardness ultimately decreased. This adjustability of hardness allows the material to better adapt to the hardness requirements of different application scenarios.

[0063] The polyurethane sealant of this invention has excellent mechanical properties. Its tensile strength can reach over 10 MPa, and its elongation can reach over 390%.

[0064] The polyurethane sealant of this invention uses cyclohexane polyacid derivatives as environmentally friendly plasticizers, and the prepared sealant does not contain phthalic acid plasticizers, which meets the strict requirements of modern society for green and environmentally friendly materials.

Claims

1. A method for preparing a one-component moisture-curing polyurethane sealant, characterized in that: Includes the following steps: (1) Synthesis of hydroxyl-terminated siloxane chain extender (BK): First, 1,4-butanediol diglycidyl ether (BDG) and KH-590 were added to a flask at a molar ratio of 1:

2. Then, triethylamine (TEA) at 1% (by weight of KH-590) was added as a catalyst. The reaction was heated at 60°C for 3 hours to obtain the product, a terminal hydroxyl siloxane chain extender (BK). The reaction process was monitored using Fourier transform infrared spectroscopy (FT-IR), and the product was characterized by ¹H NMR spectroscopy. The NMR characterization data are as follows: ¹H NMR (400... MHz, DMSO-d6) δ4.89–4.81 (m, 2H), 3.77–3.57 (m, 2H), 3.47 (s, 18H), 3.40–3.36 (m, 4H), 3.33 (m, 4H), 2.56–2.44 (m, 8H), 1.61–1.51 (m, 8H), 0.71–0.64 (m, 4H); (2) Weigh the measured amount of polyol and place it in a four-necked flask. Heat it to 110°C using a heating mantle. Then dehydrate it for 1.5 hours using a rotary vane vacuum pump. Cool the polyol to 80°C and add isocyanate at 80°C according to the ratio of R=2.4 (the ratio of -NCO groups to -OH groups). Add 0.1% of dibutyltin dilaurate (DBTDL) as a catalyst and react for 3 hours under nitrogen (N2) protection to obtain polyurethane (PU) prepolymer. (3) In a nitrogen (N2) atmosphere, add hydroxyl-terminated siloxane chain extender (BK) to the polyurethane (PU) prepolymer prepared above, and then add 0.1% of dibutyltin dilaurate (DBTDL) by mass. React at 80°C for 3 hours to obtain side-chain silane modified polyurethane resin (i.e. SPU-BK resin). (4) First, dry nano-calcium carbonate and carbon black at 110°C for 48 hours in a forced-air drying oven, and keep them dry and cooled for later use. Add side-chain silane modified polyurethane resin SPU-BK, green plasticizer, carbon black and nano-calcium carbonate to a double planetary mixer in sequence. Under argon protection, keep the temperature below 45°C and stir at high speed for 25-35 minutes. Add coupling agent, p-toluenesulfonyl isocyanate (PTSI), ultraviolet light absorber and anti-aging agent to the mixer in sequence, and continue to stir at high speed for 10-15 minutes under argon protection and below 45°C. Add bismorpholino diethyl ether (DMDEE) to the mixer and stir at high speed for 10-15 minutes under nitrogen protection and below 45°C. Then perform vacuum degassing treatment to obtain the sealant. In step 3, the molar ratio of the terminal hydroxyl siloxane chain extender (BK) to the polytetrahydrofuran diol (PTMEG) and isophorone diisocyanate (IPDI) in step 2 is 0.0042~0.021:0.03:0.072; In step 4, the weight ratio of SPU-BK, green plasticizer, carbon black, nano calcium carbonate, p-toluenesulfonyl isocyanate, ultraviolet absorber, anti-aging agent, coupling agent, and bismorpholino diethyl ether is 25-40:10-23:23-25:22.5-26.5:0.5:0.5:0.5:1.2:0.

2.

2. The method for preparing a single-component moisture-curing polyurethane sealant according to claim 1, characterized in that: The amount of BK added was 0.0210 mol.

3. The method for preparing a single-component moisture-curing polyurethane sealant according to claim 1, characterized in that: The amount of BK added was 0.0168 mol.

4. The method for preparing a single-component moisture-curing polyurethane sealant according to claim 1, characterized in that: The amount of BK added was 0.0126 mol.

5. The method for preparing a single-component moisture-curing polyurethane sealant according to claim 1, characterized in that: The amount of BK added was 0.0084 mol.

6. The method for preparing a single-component moisture-curing polyurethane sealant according to claim 1, characterized in that: The amount of BK added was 0.0042 mol.

7. The method for preparing a single-component moisture-curing polyurethane sealant according to claim 4, characterized in that: The weight ratios of SPU-30, green plasticizer (dioctyl cyclohexane 1,2-dicarboxylate), carbon black, nano calcium carbonate, p-toluenesulfonyl isocyanate, ultraviolet absorber (2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole), anti-aging agent (β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol), coupling agent (KH-560), and bismorpholino diethyl ether are 25:23:23:26.5:0.5:0.5:0.5:1.2:0.

2.

8. The method for preparing a single-component moisture-curing polyurethane sealant according to claim 4, characterized in that: The weight ratios of SPU-30, green plasticizer (dioctyl cyclohexane 1,2-dicarboxylate), carbon black, nano calcium carbonate, p-toluenesulfonyl isocyanate, ultraviolet absorber (2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole), anti-aging agent (β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol), coupling agent (KH-560), and bismorpholino diethyl ether are 30:18:23.5:26:0.5:0.5:0.5:1.2:0.

2.

9. The method for preparing a single-component moisture-curing polyurethane sealant according to claim 4, characterized in that: The weight ratios of SPU-30, green plasticizer (dioctyl cyclohexane 1,2-dicarboxylate), carbon black, nano calcium carbonate, p-toluenesulfonyl isocyanate, ultraviolet absorber (2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole), anti-aging agent (β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol), coupling agent (KH-560), and bismorpholino diethyl ether are 35:13:24:25.5:0.5:0.5:0.5:1.2:0.

2.

10. The method for preparing a single-component moisture-curing polyurethane sealant according to claim 4, characterized in that: The weight ratios of SPU-30, green plasticizer (dioctyl cyclohexane 1,2-dicarboxylate), carbon black, nano calcium carbonate, p-toluenesulfonyl isocyanate, ultraviolet absorber (2-(2'-hydroxy-3',5'-di-tert-butylphenyl)-5-chlorobenzotriazole), anti-aging agent (β-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate n-octadecyl alcohol), coupling agent (KH-560), and bismorpholino diethyl ether are 40:10:25:22.5:0.5:0.5:0.5:1.2:0.2.

Images