Super-soft weather-resistant and fast-curing polyurethane sealant and preparation method thereof

Abstract

The application discloses a kind of super-soft weather-resistant, fast solidification type polyurethane sealant and preparation method thereof, it is related to polyurethane sealant technical field, the sealant is obtained by mixing according to proportion by A component and B component;The A component is composed of modified polyurethane prepolymer, first plasticizer, dimethylbenzene, first filler, gamma-glycidyl ether oxygen propyl trimethoxysilane, water-removing agent and isocyanate curing agent;The B component is composed of second 3 functionality polyether polyol, second filler, second plasticizer, organic tin catalyst and delay catalyst;The modified polyurethane prepolymer is prepared by tackifying resin, terminal hydroxyl polybutadiene and first 3 functionality polyether polyol;The sealant of the application can realize stable bonding to neoprene and polyurethane base material, and shows excellent high and low temperature resistance and curing-operation balance performance, effectively solve the contradiction between the curing speed and operating performance of existing polyurethane sealant, improve product application practicability.

Description

Technical Field

[0001] This invention relates to the field of polyurethane sealant technology, specifically to an ultra-flexible, weather-resistant, and fast-curing polyurethane sealant and its preparation method. Background Technology

[0002] In modern industrial manufacturing and construction, the performance of sealing and adhesive materials directly affects product quality and engineering durability. Neoprene rubber and polyurethane substrates are widely used due to their excellent physicochemical properties. Neoprene rubber possesses good weather resistance, oil resistance, and chemical corrosion resistance, playing a vital role in automotive parts, rubber products, and building seals. Polyurethane substrates, with their high elasticity, high strength, wear resistance, and good processing properties, are commonly used in the preparation of foam materials, elastomers, and coatings, finding extensive applications in aerospace, furniture manufacturing, and building insulation industries.

[0003] Traditional sealants present numerous problems when applied to neoprene and polyurethane substrates. For example, ordinary sealants cure slowly, leading to low production efficiency, increased labor and time costs, and the bonding effect is easily affected by external factors (such as vibration and displacement) before complete curing, reducing the reliability of sealing and bonding. Regarding substrate compatibility, conventional sealants struggle to form strong chemical bonds with neoprene and polyurethane substrates, especially in complex environments (such as high temperature, high humidity, and chemical corrosion), easily resulting in debonding and cracking, severely impacting sealing and bonding performance and shortening the product or project's lifespan. Furthermore, existing sealants also present a trade-off between storage stability and reactivity, failing to achieve a perfect balance between the two.

[0004] Therefore, there is an urgent need for a sealant that can cure quickly, has excellent adhesion to neoprene and polyurethane substrates, and can meet the durability requirements of sealants in complex environments. Summary of the Invention

[0005] To address the aforementioned problems, the present invention aims to provide an ultra-flexible, weather-resistant, and fast-curing polyurethane sealant and its preparation method. This sealant can solve problems such as insufficient interfacial bonding strength between chloroprene rubber and polyurethane substrate, easy adhesion failure, loss of elasticity at low temperatures, and creep at high temperatures, thus achieving a balance between the storage stability and reactivity of the sealant.

[0006] To achieve the above objectives, the present invention employs the following technical solution: An ultra-flexible, weather-resistant, and fast-curing polyurethane sealant is obtained by mixing component A and component B in a mass ratio of 5:1. Component A, by weight, consists of the following raw materials: 30-40 parts modified polyurethane prepolymer, 15-25 parts first plasticizer, 1-3 parts xylene, 30-40 parts first filler, 0.1-0.5 parts γ-glycidyl etheroxypropyltrimethoxysilane, 1-3 parts dehydrating agent, and 0.5-3 parts isocyanate curing agent. Component B, by weight, consists of the following raw materials: 2-6 parts second trifunctional polyether polyol, 12-16 parts second filler, 1-3 parts second plasticizer, 0.02-0.1 parts organotin catalyst, and 0.01-0.04 parts delayed catalyst. The modified polyurethane prepolymer is prepared from a tackifying resin, hydroxyl-terminated polybutadiene, and a first trifunctional polyether polyol.

[0007] Preferably, the modified polyurethane prepolymer is prepared according to the following steps: First trifunctional polyether polyol, hydroxyl-terminated polybutadiene, and tackifying resin are added to a reactor. The mixture is gradually heated to 105-125°C under stirring, and mixed evenly. The mixture is then evacuated to ≤-0.095 MPa and dehydrated for 1-3 hours. The temperature is then lowered to 60-70°C, and nitrogen is used to break the vacuum. The stirring speed is adjusted to 250-350 rpm, and diphenylmethane diisocyanate is added. The temperature is raised to 76-86°C and the reaction is maintained for 4-5 hours. The NCO content is measured every 30 minutes. When the NCO content is 1.8-3.2%, heating is stopped and the temperature is lowered to 20-30°C to obtain the modified polyurethane prepolymer. The mass ratio of the first trifunctional polyether polyol, hydroxyl-terminated polybutadiene, tackifying resin and diphenylmethane diisocyanate is 25~27:50~55:7~10:12~16.

[0008] Preferably, the tackifying resin is rosin glycol or phenol-modified terpene resin.

[0009] Preferably, the first plasticizer and the second plasticizer are diisodecyl phthalate, diisononyl phthalate, or di-n-octyl phthalate.

[0010] Preferably, the first filler is nano-calcium carbonate, heavy calcium carbonate, or calcium oxide; the second filler is heavy calcium carbonate or calcium oxide.

[0011] Preferably, the dehydrating agent is p-toluenesulfonyl isocyanate.

[0012] Preferably, the organotin catalyst is dibutyltin dilaurate; the delayed catalyst is the Niax organotin catalyst from Maitu. TM Catalyst LC-5629 or Umicore Valikat® DCC1410.

[0013] This invention also includes a method for preparing an ultra-flexible, weather-resistant, and fast-curing polyurethane sealant, comprising the following steps: ① Preparation of Component A: Weigh 15-25 parts by weight of the first plasticizer, 1-3 parts by weight of xylene, and 0.1-0.5 parts by weight of γ-glycidyl etheroxypropyltrimethoxysilane and add them to the glue mixing tank. Stir and mix well. Add 30-40 parts by weight of the first filler and stir well. Vacuum stir for 35-45 minutes. Add 1-3 parts by weight of the dehydrating agent and vacuum stir for 15-25 minutes. Add 30-40 parts by weight of the modified polyurethane prepolymer and 0.5-3 parts by weight of the isocyanate curing agent and vacuum stir for 15-20 minutes. Discharge the material to obtain Component A. The modified polyurethane prepolymer is prepared from a tackifying resin, hydroxyl-terminated polybutadiene, and a first trifunctional polyether polyol. ② Preparation of component B: By weight, 2-6 parts of the second trifunctional polyether polyol, 1-3 parts of the second plasticizer, 0.02-0.1 parts of the organotin catalyst and 0.01-0.04 parts of the delay catalyst are added to the glue mixing tank and stirred under normal pressure. Then, 12-16 parts of the second filler are added and stirred under vacuum for 25-35 minutes. The mixture is then discharged to obtain component B. ③ When using, mix component A and component B evenly at a mass ratio of 5:1 to obtain an ultra-flexible, weather-resistant, and fast-curing polyurethane sealant.

[0014] The present invention has the following advantages over the prior art: This invention discloses an ultra-flexible, weather-resistant, and fast-curing polyurethane sealant that can achieve stable bonding between neoprene rubber and polyurethane substrates, and exhibits excellent high and low temperature resistance and curing-handling balance performance. It effectively solves the contradiction between the curing speed and handling performance of existing polyurethane sealants, and improves the practicality of product applications.

[0015] First, modified polyurethane prepolymers were prepared using tackifying resins, hydroxyl-terminated polybutadiene, and polyether polyols as raw materials. To address the significant polarity difference between chloroprene rubber and polyurethane substrates, tackifying resins and hydroxyl-terminated polybutadiene, which exhibit excellent compatibility and tackifying effects with the chloroprene rubber substrate, were introduced and combined with polyether polyols commonly used in polyurethane substrates to prepare polyurethane prepolymers, thereby improving the interfacial adhesion strength between chloroprene rubber and the polyurethane substrate. Through the molecular structural balance of a "rigid MDI backbone + flexible polyether / HTPB segments" and the interfacial reinforcement of the high-softening-point tackifying resin, the high and low temperature resistance of the modified polyurethane prepolymers can be significantly improved.

[0016] Secondly, this application regulates the reaction rate of -NCO and -OH under the combined action of organotin catalyst and delayed catalyst, achieving the dual goal of "long open time + short curing time", thus resolving the contradiction between curing speed and operation performance of existing polyurethane sealants. Detailed Implementation

[0017] The purpose of this invention is to provide an ultra-flexible, weather-resistant, and fast-curing polyurethane sealant and its preparation method, which is achieved through the following technical solution: The rosin diol of this invention is manufactured by Xiamen Weier Chemical Co., Ltd., and its model number is WRES-085; the phenol-modified terpene resin is manufactured by Xiamen Weier Chemical Co., Ltd., and its model number is WTP-105.

[0018] The hydroxyl values ​​of the raw materials of this invention are as follows: the hydroxyl value of the first trifunctional polyether polyol is 25~30 mgKOH / g; the hydroxyl value of the second trifunctional polyether polyol is 225~255 mgKOH / g; the hydroxyl value of the hydroxyl-terminated polybutadiene is 0.47~0.53 mmol / g; the hydroxyl value of the rosin glycol tackifying resin is 115-125 mgKOH / g; and the hydroxyl value of the phenol-modified terpene resin tackifying resin is 45-55 mgKOH / g.

[0019] The present invention will be further described below with reference to specific embodiments. Example

[0020] An ultra-flexible, weather-resistant, and fast-curing polyurethane sealant is obtained by mixing component A and component B in a mass ratio of 5:1. Component A consists of the following raw materials: 30 kg of modified polyurethane prepolymer, 15 kg of diisodecyl phthalate, 1 kg of xylene, 30 kg of nano-calcium carbonate, 0.1 kg of γ-glycidyl etheroxypropyltrimethoxysilane, 1 kg of p-toluenesulfonyl isocyanate, and 0.5 kg of isocyanate curing agent. Component B consists of the following raw materials: 2 kg of second-trifunctional polyether polyol, 12 kg of heavy calcium carbonate, 1 kg of diisodecyl phthalate, 0.02 kg of dibutyltin dilaurate, and 0.01 kg of delayed catalyst Umicore Valikat® DCC1410. The modified polyurethane prepolymer is prepared from a tackifying resin, hydroxyl-terminated polybutadiene, and a first-trifunctional polyether polyol, and the specific steps are as follows: 10 kg of the first trifunctional polyether polyol, 20 kg of hydroxyl-terminated polybutadiene, and 2.8 kg of tackifying resin were added to a reactor. The temperature was gradually increased to 105°C, and the mixture was stirred evenly. The system was then evacuated to ≤-0.095 MPa and dehydrated for 1 hour. The temperature was then reduced to 60°C, and nitrogen was used to break the vacuum. The stirring speed was adjusted to 250 rpm, and 4.8 kg of diphenylmethane diisocyanate was added. The temperature was increased to 76°C, and the reaction was maintained for 4 hours. The NCO content was measured every 30 minutes. When the NCO content was 2.0 ± 0.2%, the heating was stopped and the temperature was reduced to 20°C to obtain the modified polyurethane prepolymer. The tackifying resin is rosin diol. Example

[0021] An ultra-flexible, weather-resistant, and fast-curing polyurethane sealant is obtained by mixing component A and component B in a mass ratio of 5:1. Component A consists of the following raw materials: 40 kg of modified polyurethane prepolymer, 25 kg of diisononyl phthalate, 3 kg of xylene, 40 kg of heavy calcium carbonate, 0.5 kg of γ-glycidyl etheroxypropyltrimethoxysilane, 3 kg of p-toluenesulfonyl isocyanate, and 3 kg of isocyanate curing agent. Component B consists of the following raw materials: 6 kg of trifunctional polyether polyol, 16 kg of calcium oxide, 3 kg of diisononyl phthalate, 0.1 kg of dibutyltin dilaurate, and Niax organotin catalyst. TM Catalyst LC-5629 0.04kg; The modified polyurethane prepolymer is prepared from a tackifying resin, hydroxyl-terminated polybutadiene, and a first-trifunctional polyether polyol, and the specific steps are as follows: 10.8 kg of the first trifunctional polyether polyol, 22 kg of hydroxyl-terminated polybutadiene, and 4 kg of tackifying resin were added to a reactor. The mixture was gradually heated to 125°C under stirring and mixed evenly. The reactor was then evacuated to ≤-0.095 MPa and dehydrated for 3 hours. The mixture was then cooled to 70°C and purged with nitrogen to break the vacuum. The stirring speed was adjusted to 350 rpm, and 6.4 kg of diphenylmethane diisocyanate was added. The mixture was heated to 86°C and kept at this temperature for 5 hours. The NCO content was measured every 30 minutes. When the NCO content was 3.0 ± 0.2%, the heating was stopped and the temperature was lowered to 30°C to obtain the modified polyurethane prepolymer. The tackifying resin is a phenol-modified terpene resin. Example

[0022] An ultra-flexible, weather-resistant, and fast-curing polyurethane sealant is obtained by mixing component A and component B in a mass ratio of 5:1. Component A consists of the following raw materials: 32 kg of modified polyurethane prepolymer, 16 kg of di-n-octyl phthalate, 1.4 kg of xylene, 32 kg of calcium oxide, 0.4 kg of γ-glycidyl etheroxypropyltrimethoxysilane, 2.2 kg of p-toluenesulfonyl isocyanate, and 0.6 kg of isocyanate curing agent. Component B consists of the following raw materials: 3 kg of second-trifunctional polyether polyol, 13 kg of calcium oxide, 1.2 kg of diisodecyl phthalate, 0.03 kg of dibutyltin dilaurate, and 0.02 kg of delayed catalyst Umicore Valikat® DCC1410. The modified polyurethane prepolymer is prepared from a tackifying resin, hydroxyl-terminated polybutadiene, and a first-trifunctional polyether polyol, and the specific steps are as follows: 10.4 kg of the first trifunctional polyether polyol, 20.8 kg of hydroxyl-terminated polybutadiene, and 3.2 kg of tackifying resin were added to a reactor. The mixture was gradually heated to 110°C under stirring and mixed evenly. The reactor was then evacuated to ≤-0.095 MPa and dehydrated for 1.5 hours. The mixture was then cooled to 62°C and purged with nitrogen to break the vacuum. The stirring speed was adjusted to 260 rpm, and 5.84 kg of diphenylmethane diisocyanate was added. The mixture was heated to 78°C and kept at this temperature for 4.5 hours. The NCO content was measured every 30 minutes. When the NCO content was 2.5 ± 0.2%, the heating was stopped and the temperature was lowered to 25°C to obtain the modified polyurethane prepolymer. The tackifying resin is rosin diol. Example

[0023] A super-flexible, weather-resistant, and fast-curing polyurethane sealant is obtained by mixing component A and component B in a mass ratio of 5:1. Component A consists of the following raw materials: 38 kg of modified polyurethane prepolymer, 22 kg of diisodecyl phthalate, 2.5 kg of xylene, 36 kg of nano-calcium carbonate, 0.2 kg of γ-glycidyl etheroxypropyltrimethoxysilane, 2.5 kg of p-toluenesulfonyl isocyanate, and 0.5 kg of isocyanate curing agent. Component B consists of the following raw materials: 3.6 kg of di-trifunctional polyether polyol, 14 kg of heavy calcium carbonate, 2.5 kg of diisononyl phthalate, 0.04 kg of dibutyltin dilaurate, and Niax organotin catalyst. TM Catalyst LC-5629 0.02kg; The modified polyurethane prepolymer is prepared from a tackifying resin, hydroxyl-terminated polybutadiene, and a first-trifunctional polyether polyol, and the specific steps are as follows: 10.2 kg of the first trifunctional polyether polyol, 21.6 kg of hydroxyl-terminated polybutadiene, and 3.6 kg of tackifying resin were added to a reactor. The mixture was gradually heated to 115°C under stirring and mixed evenly. The system was then evacuated to ≤-0.095 MPa and dehydrated for 1.5 hours. The mixture was then cooled to 64°C and the vacuum was broken by purging with nitrogen. The stirring speed was adjusted to 320 rpm, and 4.96 kg of diphenylmethane diisocyanate was added. The mixture was heated to 85°C and kept at this temperature for 4.5 hours. The NCO content was measured every 30 minutes. When the NCO content was 2.1 ± 0.2%, the heating was stopped and the temperature was lowered to 26°C to obtain the modified polyurethane prepolymer. The tackifying resin is a phenol-modified terpene resin. Example

[0024] An ultra-flexible, weather-resistant, and fast-curing polyurethane sealant is obtained by mixing component A and component B in a mass ratio of 5:1. Component A consists of the following raw materials: 36 kg of modified polyurethane prepolymer, 16 kg of diisononyl phthalate, 1.5 kg of xylene, 34 kg of heavy calcium carbonate, 0.3 kg of γ-glycidyl etheroxypropyltrimethoxysilane, 1.5 kg of p-toluenesulfonyl isocyanate, and 1 kg of isocyanate curing agent. Component B consists of the following raw materials: 4 kg of di-trifunctional polyether polyol, 15 kg of heavy calcium carbonate, 2.2 kg of di-n-octyl phthalate, 0.05 kg of dibutyltin dilaurate, and Niax organotin catalyst. TM Catalyst LC-5629 0.02kg; The modified polyurethane prepolymer is prepared from a tackifying resin, hydroxyl-terminated polybutadiene, and a first-trifunctional polyether polyol, and the specific steps are as follows: 10.6 kg of the first trifunctional polyether polyol, 20.8 kg of hydroxyl-terminated polybutadiene, and 3.6 kg of tackifying resin were added to a reactor. The mixture was gradually heated to 120°C under stirring and mixed evenly. The system was then evacuated to ≤-0.095 MPa and dehydrated for 2 hours. The temperature was then lowered to 64°C, and nitrogen was used to break the vacuum. The stirring speed was adjusted to 300 rpm, and 5.15 kg of diphenylmethane diisocyanate was added. The temperature was raised to 85°C and the reaction was maintained for 4.5 hours. The NCO content was measured every 30 minutes. When the NCO content was 2.3 ± 0.2%, heating was stopped and the temperature was lowered to 22°C to obtain the modified polyurethane prepolymer. The tackifying resin is a phenol-modified terpene resin. Example

[0025] An ultra-flexible, weather-resistant, and fast-curing polyurethane sealant is obtained by mixing component A and component B in a mass ratio of 5:1. Component A consists of the following raw materials: 35 kg of modified polyurethane prepolymer, 20 kg of di-n-octyl phthalate, 2 kg of xylene, 35 kg of calcium oxide, 0.3 kg of γ-glycidyl etheroxypropyltrimethoxysilane, 2 kg of p-toluenesulfonyl isocyanate, and 2 kg of isocyanate curing agent. Component B consists of the following raw materials: 5.3 kg of di-trifunctional polyether polyol, 15 kg of heavy calcium carbonate, 2 kg of diisodecyl phthalate, 0.06 kg of dibutyltin dilaurate, and 0.02 kg of delayed catalyst Umicore Valikat® DCC1410. The modified polyurethane prepolymer is prepared from a tackifying resin, hydroxyl-terminated polybutadiene, and a first-trifunctional polyether polyol, and the specific steps are as follows: 10.4 kg of the first trifunctional polyether polyol, 21.6 kg of hydroxyl-terminated polybutadiene, and 3.2 kg of tackifying resin were added to a reactor. The mixture was gradually heated to 108°C under stirring and mixed evenly. The system was then evacuated to ≤-0.095 MPa and dehydrated for 2 hours. The temperature was then lowered to 65°C, and nitrogen was used to break the vacuum. The stirring speed was adjusted to 300 rpm, and 6.23 kg of diphenylmethane diisocyanate was added. The temperature was raised to 80°C and the reaction was maintained for 4.5 hours. The NCO content was measured every 30 minutes. When the NCO content was 2.7 ± 0.2%, heating was stopped and the temperature was lowered to 25°C to obtain the modified polyurethane prepolymer. The tackifying resin is rosin diol. Example

[0026] The preparation method of the ultra-flexible, weather-resistant, and fast-curing polyurethane sealant described in Example 1 includes the following steps: ① Preparation of component A: Weigh 15 kg of diisodecyl phthalate, 1 kg of xylene, and 0.1 kg of γ-glycidyl etheroxypropyltrimethoxysilane and add them to the glue mixing tank. Stir and mix well. Add 30 kg of nano-calcium carbonate, stir and mix well, and then vacuum stir for 35 minutes. Add 1 kg of p-toluenesulfonyl isocyanate and vacuum stir for 15 minutes. Add 30 kg of modified polyurethane prepolymer and 0.5 kg of isocyanate curing agent, and vacuum stir for 15 minutes. Discharge the material to obtain component A. ② Preparation of Component B: 2 kg of second trifunctional polyether polyol, 1 kg of diisodecyl phthalate, 0.02 kg of dibutyltin dilaurate and 0.01 kg of delayed catalyst Umicore Valikat® DCC1410 were added to the gel mixing tank and stirred under normal pressure. 12 kg of heavy calcium carbonate was added and the mixture was stirred under vacuum for 25 minutes. The product was then discharged to obtain Component B. ③ When using, take 75kg of component A and 15kg of component B and mix them evenly to obtain an ultra-flexible, weather-resistant, and fast-curing polyurethane sealant. Example

[0027] The preparation method of the ultra-flexible, weather-resistant, and fast-curing polyurethane sealant described in Example 2 includes the following steps: ① Preparation of component A: Weigh 25 kg of diisononyl phthalate, 3 kg of xylene, and 0.5 kg of γ-glycidyl etheroxypropyltrimethoxysilane, add them to the glue mixing tank, stir and mix well, add 40 kg of heavy calcium carbonate, stir and mix well, then vacuum stir for 45 minutes, add 3 kg of p-toluenesulfonyl isocyanate, vacuum stir for 25 minutes, add 40 kg of modified polyurethane prepolymer and 3 kg of isocyanate curing agent, vacuum stir for 20 minutes, discharge the material to obtain component A; ② Preparation of Component B: 6 kg of the second trifunctional polyether polyol, 3 kg of diisononyl phthalate, 0.1 kg of dibutyltin dilaurate, and the Niax organotin catalyst from Maitu were prepared. TM Add 0.04 kg of Catalyst LC-5629 to the gel mixing tank, stir and mix under normal pressure, add 16 kg of calcium oxide, stir under vacuum for 35 minutes, and discharge to obtain component B; ③ When using, mix 110kg of component A and 22kg of component B evenly to obtain an ultra-flexible, weather-resistant, and fast-curing polyurethane sealant. Example

[0028] The preparation method of the ultra-flexible, weather-resistant, and fast-curing polyurethane sealant described in Example 3 includes the following steps: ① Preparation of component A: Weigh 16 kg of di-n-octyl phthalate, 1.4 kg of xylene, and 0.4 kg of γ-glycidyl etheroxypropyltrimethoxysilane and add them to the glue mixing tank. Stir and mix well. Add 32 kg of calcium oxide and stir under vacuum for 38 minutes. Add 2.2 kg of p-toluenesulfonyl isocyanate and stir under vacuum for 16 minutes. Add 32 kg of modified polyurethane prepolymer and 0.6 kg of isocyanate curing agent and stir under vacuum for 18 minutes. Discharge the material to obtain component A. ② Preparation of component B: 3 kg of second trifunctional polyether polyol, 1.2 kg of diisodecyl phthalate, 0.03 kg of dibutyltin dilaurate and 0.02 kg of delayed catalyst Umicore Valikat® DCC1410 were added to the gel mixing tank and stirred under normal pressure. 13 kg of calcium oxide was added and the mixture was stirred under vacuum for 28 minutes. The product was then discharged to obtain component B. ③ When using, mix 80kg of component A and 16kg of component B evenly to obtain an ultra-flexible, weather-resistant, and fast-curing polyurethane sealant. Example

[0029] The preparation method of the ultra-flexible, weather-resistant, and fast-curing polyurethane sealant described in Example 4 includes the following steps: ① Preparation of component A: Weigh 22 kg of diisodecyl phthalate, 2.5 kg of xylene, and 0.2 kg of γ-glycidyl etheroxypropyltrimethoxysilane and add them to the glue mixing tank. Stir and mix well. Add 36 kg of nano-calcium carbonate and stir under vacuum for 38 minutes. Add 2.5 kg of p-toluenesulfonyl isocyanate and stir under vacuum for 22 minutes. Add 38 kg of modified polyurethane prepolymer and 0.5 kg of isocyanate curing agent and stir under vacuum for 16 minutes. Discharge to obtain component A. ② Preparation of Component B: 3.6 kg of the second trifunctional polyether polyol, 2.5 kg of diisononyl phthalate, 0.04 kg of dibutyltin dilaurate, and the Niax organotin catalyst from Maitu were prepared. TM 0.02 kg of Catalyst LC-5629 was added to the glue mixing tank and stirred under normal pressure. 14 kg of heavy calcium carbonate was added and stirred under vacuum for 28 minutes. The product was then discharged to obtain component B. ③ When using, mix 100kg of component A and 20kg of component B evenly to obtain an ultra-flexible, weather-resistant, and fast-curing polyurethane sealant. Example

[0030] The preparation method of the ultra-flexible, weather-resistant, and fast-curing polyurethane sealant described in Example 5 includes the following steps: ① Preparation of component A: Weigh 16 kg of diisononyl phthalate, 1.5 kg of xylene, and 0.3 kg of γ-glycidyl etheroxypropyltrimethoxysilane and add them to the glue mixing tank. Stir and mix well. Add 34 kg of heavy calcium carbonate and stir well. Vacuum stir for 42 minutes. Add 1.5 kg of p-toluenesulfonyl isocyanate and vacuum stir for 24 minutes. Add 36 kg of modified polyurethane prepolymer and 1 kg of isocyanate curing agent and vacuum stir for 18 minutes. Discharge to obtain component A. ② Preparation of Component B: 4 kg of the second trifunctional polyether polyol, 2.2 kg of di-n-octyl phthalate, 0.05 kg of dibutyltin dilaurate, and the Niax organotin catalyst from Maitu were prepared. TM 0.02 kg of Catalyst LC-5629 was added to the glue mixing tank and stirred under normal pressure. 15 kg of heavy calcium carbonate was added and stirred under vacuum for 30 minutes. The product was then discharged to obtain component B. ③ When using, mix 85kg of component A and 17kg of component B evenly to obtain an ultra-flexible, weather-resistant, and fast-curing polyurethane sealant. Example

[0031] The preparation method of the ultra-flexible, weather-resistant, and fast-curing polyurethane sealant described in Example 6 includes the following steps: ① Preparation of component A: Weigh 20 kg of di-n-octyl phthalate, 2 kg of xylene, and 0.3 kg of γ-glycidyl etheroxypropyltrimethoxysilane and add them to the glue mixing tank. Stir and mix well. Add 35 kg of calcium oxide and stir well. Vacuum stir for 40 minutes. Add 2 kg of p-toluenesulfonyl isocyanate and vacuum stir for 20 minutes. Add 35 kg of modified polyurethane prepolymer and 2 kg of isocyanate curing agent and vacuum stir for 16 minutes. Discharge to obtain component A. ② Preparation of component B: 5.3 kg of second trifunctional polyether polyol, 2 kg of diisodecyl phthalate, 0.06 kg of dibutyltin dilaurate and 0.02 kg of delayed catalyst Umicore Valikat® DCC1410 were added to the gelation tank and stirred under normal pressure. 15 kg of heavy calcium carbonate was added and stirred under vacuum for 30 minutes. The mixture was then discharged to obtain component B. ③ When using, mix 95kg of component A and 19kg of component B evenly to obtain an ultra-flexible, weather-resistant, and fast-curing polyurethane sealant.

[0032] The mechanical properties of the ultra-flexible, weather-resistant, and fast-curing polyurethane sealants obtained in Examples 7-12 were tested. Shore A hardness was tested according to GB / T 531.1-2008, tensile strength according to GB / T 528-2009, elongation at break according to GB / T 528-2009, and peel strength according to GB / T 2791-1995. The results are shown in Table 1.

[0033] Table 1. Mechanical properties of the ultra-flexible, weather-resistant, and fast-curing polyurethane sealants obtained in Examples 7-12

[0034] The ultra-flexible, weather-resistant, and fast-curing polyurethane sealants obtained in Examples 7-12 were tested for their heat resistance, damp heat resistance, and low-temperature resistance when bonded between chlorinated butyl rubber and a polyurethane substrate. The heat resistance was tested at 100°C for 24 hours, the damp heat resistance was tested at 70°C and 95%RH for 300 hours, and the low-temperature resistance was tested at -40°C for 24 hours. The results are shown in Table 2.

[0035] Table 2 Results of heat resistance, damp heat resistance and low temperature resistance

[0036] The open time and surface drying time of the ultra-flexible, weather-resistant, and fast-curing polyurethane sealants obtained in Examples 7-12 under standard conditions (23°C, 50%RH) are shown in Table 3.

[0037] Table 3. Results of Opening Hours and Stem Time

[0038] As shown in Tables 2 and 3, the ultra-flexible, weather-resistant, and fast-curing polyurethane sealant of this invention can achieve high-strength bonding between neoprene rubber and polyurethane substrates. Under high temperature and humidity, and high and low temperature conditions, the peel strength of the bonded samples is ≥2.0 KN / m, exhibiting aging resistance and achieving the curing control target of "long open time + short curing time". The open time of each embodiment of the polyurethane sealant of this invention is 3~12 min, with a maximum of 12 min, providing sufficient adjustable window for various working conditions (mechanical construction or manual operation) to meet the construction requirements of "long open time". At the same time, the surface drying time of each embodiment is 4~20 min, and the difference between the surface drying time and the open time is only 1~8 min, indicating that the adhesive can quickly enter the curing stage after the open time, achieving the control target of "short curing time". In summary, the sealant of this invention, through formulation design, successfully achieves the control of curing performance of "long open time + short curing time", ensuring both construction convenience and improving curing efficiency. This is because the ultra-flexible, weather-resistant, and fast-curing polyurethane sealant structure of the present invention is prepared by compounding tackifying resin, hydroxyl-terminated polybutadiene and polyether polyol to prepare modified polyurethane prepolymer, and at the same time compounded with organometallic and delayed catalyst, to construct a synergistic catalytic mechanism in the system to regulate the reaction rate.

Claims

1. A super-flexible, weather-resistant, and fast-curing polyurethane sealant, characterized in that: The mixture is obtained by mixing component A and component B in a mass ratio of 5:

1. Component A, by weight, consists of the following raw materials: 30-40 parts modified polyurethane prepolymer, 15-25 parts first plasticizer, 1-3 parts xylene, 30-40 parts first filler, 0.1-0.5 parts γ-glycidyl etheroxypropyltrimethoxysilane, 1-3 parts dehydrating agent, and 0.5-3 parts isocyanate curing agent. Component B, by weight, consists of the following raw materials: 2-6 parts second trifunctional polyether polyol, 12-16 parts second filler, 1-3 parts second plasticizer, 0.02-0.1 parts organotin catalyst, and 0.01-0.04 parts delayed catalyst. The modified polyurethane prepolymer is prepared from a tackifying resin, hydroxyl-terminated polybutadiene, and a first trifunctional polyether polyol.

2. The ultra-flexible, weather-resistant, and fast-curing polyurethane sealant according to claim 1, characterized in that: The modified polyurethane prepolymer was prepared according to the following steps: First trifunctional polyether polyol, hydroxyl-terminated polybutadiene, and tackifying resin are added to a reactor. The mixture is gradually heated to 105-125°C under stirring, and mixed evenly. The mixture is then evacuated to ≤-0.095 MPa and dehydrated for 1-3 hours. The temperature is then lowered to 60-70°C, and nitrogen is used to break the vacuum. The stirring speed is adjusted to 250-350 rpm, and diphenylmethane diisocyanate is added. The temperature is raised to 76-86°C and the reaction is maintained for 4-5 hours. The NCO content is measured every 30 minutes. When the NCO content is 1.8-3.2%, heating is stopped and the temperature is lowered to 20-30°C to obtain the modified polyurethane prepolymer. The mass ratio of the first trifunctional polyether polyol, hydroxyl-terminated polybutadiene, tackifying resin and diphenylmethane diisocyanate is 25~27:50~55:7~10:12~16.

3. The ultra-flexible, weather-resistant, and fast-curing polyurethane sealant according to claim 1 or 2, characterized in that: The tackifying resin is rosin glycol or phenol-modified terpene resin.

4. The ultra-flexible, weather-resistant, and fast-curing polyurethane sealant according to claim 1, characterized in that: The first plasticizer and the second plasticizer are diisodecyl phthalate, diisononyl phthalate or di-n-octyl phthalate.

5. The ultra-flexible, weather-resistant, and fast-curing polyurethane sealant according to claim 1, characterized in that: The first filler is nano-calcium carbonate, heavy calcium carbonate, or calcium oxide; the second filler is heavy calcium carbonate or calcium oxide.

6. The ultra-flexible, weather-resistant, and fast-curing polyurethane sealant according to claim 1, characterized in that: The dehydrating agent is p-toluenesulfonyl isocyanate.

7. The ultra-flexible, weather-resistant, and fast-curing polyurethane sealant according to claim 1, characterized in that: The organotin catalyst is dibutyltin dilaurate; the delayed catalyst is the Niax organotin catalyst from Maitu. TM Catalyst LC-5629 or Umicore Valikat® DCC1410.

8. The preparation method of the ultra-flexible, weather-resistant, and fast-curing polyurethane sealant according to claim 1, characterized in that: Includes the following steps: ① Preparation of Component A: Weigh 15-25 parts by weight of the first plasticizer, 1-3 parts by weight of xylene, and 0.1-0.5 parts by weight of γ-glycidyl etheroxypropyltrimethoxysilane and add them to the glue mixing tank. Stir and mix well. Add 30-40 parts by weight of the first filler and stir well. Vacuum stir for 35-45 minutes. Add 1-3 parts by weight of the dehydrating agent and vacuum stir for 15-25 minutes. Add 30-40 parts by weight of the modified polyurethane prepolymer and 0.5-3 parts by weight of the isocyanate curing agent and vacuum stir for 15-20 minutes. Discharge the material to obtain Component A. The modified polyurethane prepolymer is prepared from a tackifying resin, hydroxyl-terminated polybutadiene, and a first trifunctional polyether polyol. ② Preparation of component B: By weight, 2-6 parts of the second trifunctional polyether polyol, 1-3 parts of the second plasticizer, 0.02-0.1 parts of the organotin catalyst and 0.01-0.04 parts of the delay catalyst are added to the glue mixing tank and stirred under normal pressure. Then, 12-16 parts of the second filler are added and stirred under vacuum for 25-35 minutes. The mixture is then discharged to obtain component B. ③ When using, mix component A and component B evenly at a mass ratio of 5:1 to obtain an ultra-flexible, weather-resistant, and fast-curing polyurethane sealant.

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