A single-component polyurethane sealant system with high storage stability and controllable curing reaction and preparation method thereof

Abstract

The invention discloses a single-component polyurethane sealant system with high storage stability and a preparation method thereof, wherein the system mainly comprises a polyurethane prepolymer, carbon black, a plasticizer, a hyperbranched polymer system loaded with a catalyst / accelerator system, and the like as main components, and a single-component polyurethane sealant system with high storage stability and a controllable curing reaction is prepared. The invention aims at the problems of slow curing speed and short storage period of single-component polyurethane sealant, and synthesizes a hyperbranched polymer hybrid system loaded with a catalyst / accelerator system by utilizing the structural characteristics of the hyperbranched polymer, thereby solving the problem of short storage period of the polyurethane sealant on the one hand, and achieving the purpose of controlling the curing reaction of the single-component polyurethane by controlling the release of the catalyst / accelerator system on the other hand.

Description

Technical Field

[0001] The invention belongs to the technical field of single-component polyurethane sealant system structure and performance design, and specifically relates to a single-component polyurethane sealant system with high storage stability and controllable curing reaction and a preparation method thereof. Background Art

[0002] One-component curing polyurethane sealant is a type of polyurethane adhesive with high tensile strength, excellent elasticity, wear resistance, oil resistance and cold resistance. It is easy to use, has high bonding strength and good stacking properties. It is currently the most ideal bonding and sealing material for the bonding structure used in window glass assembly. However, as a one-component sealant, it currently has the problem of slow curing speed. The curing speed of polyurethane can be accelerated by adding catalysts and accelerators, but its storage stability will be significantly reduced, which significantly reduces the applicability of polyurethane. Therefore, the development of a controllable curing one-component polyurethane sealant with good storage stability is of great significance for expanding the application of polyurethane. Summary of the invention

[0003] The present invention aims at solving the problems of slow curing speed and short storage period of single-component polyurethane sealant. By utilizing the structural characteristics of hyperbranched polymers, a hyperbranched polymer hybrid system loaded with a catalyst / accelerator system is synthesized. On the one hand, the problem of short storage period of polyurethane sealant is solved. On the other hand, the purpose of controlling the curing reaction of single-component polyurethane is achieved by controlling the release of the catalyst / accelerator system.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is:

[0005] A single-component polyurethane sealant system with high storage stability and a controllable curing reaction and a preparation method thereof, wherein the components and mass ratio of the single-component polyurethane sealant system with high storage stability and a controllable curing reaction are as follows: polyurethane prepolymer, carbon black, plasticizer, hyperbranched polymer system loaded with a catalyst / accelerator system, epoxy resin, calcium carbonate, heavy calcium, coupling agent = (50-100): (20-60): (20-40): (5-10): (0-25): (0-5): (0-5): (0-1), when a component is 0, it means that the system does not contain the component. Among them, the preferred ratio of polyurethane prepolymer, carbon black, plasticizer, and hyperbranched polymer system loaded with a catalyst / accelerator system is 50: (20-35): (20-25): (5-6).

[0006] In the present invention, the preparation method of the above-mentioned one-component polyurethane sealant system with high storage stability and controllable curing reaction is as follows: polyurethane prepolymer, carbon black, plasticizer, hyperbranched polymer system loaded with catalyst / accelerator system, epoxy resin, calcium carbonate, heavy calcium, and coupling agent are mixed according to the mass ratio of (50-100): (20-60): (20-40): (5-10): (0-25): (0-5): (0-5): (0-1) to obtain a one-component polyurethane sealant system with high storage stability and controllable curing reaction; when a certain component is 0, it means that the system does not contain the component. Specifically, at room temperature, epoxy resin is added to the polyurethane prepolymer, and after stirring, plasticizer, carbon black, calcium carbonate and heavy calcium are added, and stirring is continued. Then, at room temperature, the hyperbranched polymer system loaded with catalyst / accelerator system is added, and vacuum stirring is performed to obtain the one-component polyurethane sealant system, which is sealed and stored for use. Before use, preheat the sealant at 80-100°C or ultrasonicate for 2-5 minutes.

[0007] In the present invention, the preparation process of the hyperbranched polymer system loaded with a catalyst / promoter system is as follows: adding the catalyst / promoter system into a hyperbranched polymer (HBP), controlling the reaction temperature to be room temperature to 80°C, stirring for 0.5 to 4 hours, and obtaining the hyperbranched polymer system loaded with the catalyst / promoter system, wherein the mass ratio of HBP to the catalyst / promoter system is 100: (1 to 25); the catalyst / promoter system is a catalyst, or a catalyst and a promoter.

[0008] In the present invention, the catalyst is an organic tin catalyst, such as dibutyltin dilaurate, stannous octoate, etc.; the promoter is a tertiary amine, such as triethylamine, diethylenetriamine, 1-methyl-4-(2-dimethylaminoethyl)piperazine, N,N-dimethylbenzylamine, piperazine, triethanolamine, etc.; wherein the mass ratio of the catalyst to the promoter is (1-4): (0-20), and when the promoter is 0, the catalyst / promoter system is a catalyst.

[0009] In the present invention, the polyurethane prepolymer is various polyurethane prepolymers terminated with different contents of -NCO (2 to 8%), such as: polyether polyurethane prepolymer, polyester polyurethane prepolymer, polytetrahydrofuran urethane prepolymer, polycaprolactone polyurethane prepolymer and mixtures thereof.

[0010] In the present invention, the plasticizer includes dioctyl phthalate, dibutyl phthalate, dioctyl sebacate, dioctyl adipate, and diisononyl phthalate; the epoxy resin includes one or more of glycidyl ether epoxy resin (such as bisphenol A epoxy resin, bisphenol F epoxy resin, phenolic epoxy resin), glycidyl ester epoxy resin, glycidyl amine epoxy resin, alicyclic epoxy resin, and linear aliphatic epoxy compound.

[0011] In the present invention, the hyperbranched polymer (HBP) is a functional group-terminated hyperbranched polyester, a functional group-terminated hyperbranched polyether, a functional group-terminated hyperbranched polyamide ester, a functional group-terminated hyperbranched polyamide, or a functional group-terminated hyperbranched polyurethane, wherein the functional group is a carboxyl group, a hydroxyl group, or an amino group; the above hyperbranched polymers are aliphatic or aromatic hyperbranched polymers, and the number average molecular weight is 2000 to 7000. Calcium carbonate and heavy calcium carbonate can be micro-nano particles and coupling agent-modified particles thereof, wherein the coupling agent can be various silane coupling agents, such as aminosilane, epoxysilane, vinylsilane, methacryloxysilane, alkylsilane, piperazine silane, etc.

[0012] In the present invention, the hyperbranched polymer system loaded with a catalyst / promoter system can be heated and ultrasonically vibrated to release the catalyst / promoter system, thereby controlling the curing of the polyurethane system. At room temperature, the hyperbranched polymer system loaded with a catalyst / promoter system has good storage stability, and the hyperbranched structure of the system and its self-assembled vesicles can effectively avoid contact between the catalyst / promoter system and other components in the polyurethane system, thereby improving the storage stability of the single-component polyurethane sealant system and controlling the curing of the polyurethane sealant system. The high storage stability single-component polyurethane sealant system of the present invention with a controllable curing reaction has a storage period of more than 8 months at a temperature below room temperature.

[0013] The one-component polyurethane sealant prepared by the one-component polyurethane sealant system with high storage stability and controllable curing reaction has high elongation and tensile strength, wherein the elongation at break can reach 511-762%; and the tensile strength can reach 14.2-21MPa.

[0014] Compared with the prior art solutions, the present invention has the following beneficial effects:

[0015] The present invention utilizes the nano-cavity structure of the hyperbranched polymer with self-assembly behavior to store the catalyst / accelerator system, which, on the one hand, avoids direct contact between the catalyst / accelerator and the polyurethane system, thereby extending the storage period of the polyurethane sealant; on the other hand, the hyperbranched polymer hybrid system can be controlled to release the catalyst / accelerator system through ultrasonic treatment, heat treatment, etc., thereby playing the function of controlling the curing reaction of the polyurethane sealant. The addition of the hyperbranched polymer hybrid system loaded with catalyst / accelerator will not reduce the elasticity of the polyurethane system, and is more conducive to improving the strength of the polyurethane system. The polyurethane sealant system of the present invention has good tensile strength and is easy to industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 FTIR (a), optical microscopy (b) and TEM (c) images of CHBPE, DBTDL, TEA and CHBPE-DBTDL-TEA system.

[0017] Figure 2 Optical microscope pictures of CHBPE-DBTDL-TEA in polyurethane prepolymer after 0h (a) and 5h (b), as well as after heat treatment at 80°C (c) and ultrasonic treatment (d) for 2min.

[0018] Figure 3 Optical microscope pictures of the polyurethane sealant films in Example 1 (a), Comparative Example 1-1 (b) and Comparative Example 1-2 (c). DETAILED DESCRIPTION

[0019] The present invention synthesizes a hyperbranched polymer hybrid system loaded with a catalyst / promoter system to control the polyurethane reaction and extend the shelf life of the polyurethane system sealant. The microcapsule has the function of protecting the capsule core and controlling the release of the capsule core. If the microcapsule containing the capsule core catalyst / promoter system is added to the single-component curing polyurethane system, the curing reaction of the polyurethane system will be effectively regulated. The hyperbranched polymer has a significant branched structure, and there are a large number of cavity structures inside it, which provides a powerful place for storing the catalyst / promoter system. In particular, the hyperbranched polymer with an amphiphilic structure can be self-assembled to form vesicles, which also creates powerful conditions to a certain extent for protecting the catalyst / promoter system and avoiding the contact of the catalyst / promoter system with the polyurethane. In addition, the hyperbranched polymer has good fluidity and film-forming properties, and the abundant hyperbranched structure can effectively maintain and improve the effect of polyurethane toughness.

[0020] In the present invention, the preparation method of the above-mentioned one-component polyurethane sealant system with high storage stability and controllable curing reaction is as follows: polyurethane prepolymer, carbon black, plasticizer, hyperbranched polymer system loaded with catalyst / accelerator system, epoxy resin, calcium carbonate, heavy calcium and coupling agent are mixed in a mass ratio of (50-100): (20-60): (20-40): (5-10): (0-25): (0-5): (0-5): (0-1) to obtain the one-component polyurethane sealant system with high storage stability and controllable curing reaction; when a certain component is 0, it means that the system does not contain the component. Specifically, at room temperature, epoxy resin is added to the polyurethane prepolymer, stirred at room temperature to 120°C for 30 minutes, and after cooling, plasticizer, carbon black, calcium carbonate and heavy calcium are added, and vacuum stirred at room temperature for 20-50 minutes. Then, at room temperature, a hyperbranched polymer system loaded with a catalyst / accelerator system is added, and vacuum stirred for 1-5 minutes to obtain a single-component polyurethane sealant system, which is sealed and stored for later use.

[0021] A one-component polyurethane sealant is prepared from the one-component polyurethane sealant system with high storage stability and controllable curing reaction. Preferably, the one-component polyurethane sealant system with high storage stability and controllable curing reaction is preheated at 80-100°C or ultrasonicated for 2-5 minutes to obtain the one-component polyurethane sealant.

[0022] The technical scheme of the present invention is further described below in conjunction with the accompanying drawings and embodiments. All raw materials of the present invention are existing products, and the specific preparation operations and performance tests are conventional technologies. Carboxyl-terminated hyperbranched polyester (CHBPE) (hyperc20, molecular weight 5200), hydroxyl-terminated aliphatic hyperbranched polyester (OHBPE) (HyPer H20, molecular weight 2600), polytetrahydrofuran (PTMEG) type polyurethane prepolymer (HJ2185, -NCO is 3.5% or HJ2195, -NCO is 6%), MDI type polyurethane prepolymer (HC-2285N, -NCO is 6.4%).

[0023] Example 1

[0024] (1) Synthesis of hyperbranched polyester hybrid system loaded with catalyst / promoter system

[0025] The catalyst / accelerator system dibutyltin dilaurate (DBTDL) / triethylamine (TEA) system was added to 1 kg of carboxyl-terminated aromatic hyperbranched polyester (CHBPE) (hyperc20, molecular weight 5200), stirred at room temperature for 1 hour, then heated to 60°C and stirred for 1 hour to obtain a hyperbranched polyester hybrid system (CHBPE-DBTDL-TEA) loaded with the catalyst / accelerator system. The mass ratio of CHBPE, DBTDL, and TEA was 5:0.05:0.2. Figure 1 These are the infrared spectra (FTIR) of CHBPE, DBTDL, TEA and CHBPE-DBTDL-TEA, and the optical microscope and transmission electron microscope (TEM) images of CHBPE-DBTDL-TEA. Figure 2 These are optical microscope pictures of CHBPE-DBTDL-TEA in polytetrahydrofuran-based polyurethane prepolymer (HJ2185, -NCO content 3.5%) after 0h and 5h, as well as optical microscope pictures after heat treatment at 80°C and ultrasonic treatment for 2min.

[0026] Figure 1 FTIR of CHPBE in a shows -OH (3456 cm -1 ), =CH (2862 cm -1 ), C=O and COC (1725 cm -1 and 1240 cm -1) stretching vibration absorption peak, C=C in the benzene ring (1666cm -1 )、-CH(1098cm -1 ) vibration absorption peaks; FTIR of DBTDL showed CH (2917 and 2862 cm -1 ) and -C=O(1725 cm -1 ) characteristic absorption peak; FTIR of TEA shows CH (2976cm -1 , 2930 cm -1 ), CN (1557cm -1 , 1380 cm -1 , 1293 cm -1 , 1070 cm -1 ) and -OH (3387cm -1 ) characteristic absorption peak.

[0027] For CHBPE-DBTDL-TEA, its FTIR shows the characteristic absorption peaks of -OH, C=O, COC and C=C in CHBPE, as well as the characteristic absorption peaks of CH in DBTDL and the characteristic absorption peaks of CH and CN in TEA, indicating that CHBPE-DBTDL-TEA may be successfully synthesized. Figure 1 b is an optical microscope image of CHBPE-DBTDL-TEA. Figure 1 No obvious phase separation structure can be observed in b, indicating that the CHBPE-DBTDL-TEA system has a uniform structure. Figure 1 c is the TEM image of the sample after CHBPE-DBTDL-TEA was dispersed in water and then dropped on a copper grid and dried at room temperature. Figure 1 c shows that CHBPE-DBTDL-TEA is a spherical structure with obvious light-colored dotted areas inside. This is due to the placement of the oil phase DBTDL-TEA in the CHBPE cavity, which further confirms that CHBPE-DBTDL-TEA was successfully synthesized. Figure 2 (a) It can be seen that CHBPE-DBTDL-TEA is dispersed in the polyurethane prepolymer system in a spherical shape, and the spherical structure can still maintain good stability after 5 hours ( Figure 2 (b) After the above system was subjected to heat treatment at 80°C or ultrasonic treatment for 2 min, it was found that the spherical dispersed phase structure disappeared, which confirmed that heat and ultrasonic treatment can destroy the assembly structure of the CHBPE-DBTDL-TEA system, thereby releasing the DBTDL / TEA system to cure the polyurethane, thereby achieving the purpose of controlling the curing reaction of the polyurethane.

[0028] (2) Preparation of one-component polyurethane sealant

[0029] At room temperature, diisononyl phthalate and carbon black (specific surface area 75m 2 / g), nano calcium carbonate (particle size 40-60nm) and heavy calcium carbonate (particle size 6.5μm), vacuum stirring for 50min, then adding CHBPE-DBTDL-TEA at room temperature, vacuum stirring for 2min, you can get a single component polyurethane, sealed and stored for use. Before use, preheat the sealant at 100°C for 2min, inject it into the mold and cure it at room temperature for 72h to get a urethane sealant with excellent mechanical properties. Among them, the mass ratio of polyurethane prepolymer, carbon black, plasticizer, hyperbranched polymer system loaded with catalyst / accelerator system, nano calcium carbonate, and heavy calcium carbonate is 50:35:25:5.25:2:2.

[0030] Comparative Example 1-1

[0031] At room temperature, diisononyl phthalate and carbon black (specific surface area 75m 2 / g), nano calcium carbonate (particle size 40-60nm) and heavy calcium carbonate (particle size 6.5μm), vacuum stirring for 50min, then adding DBTDL, TEA and CHBPE respectively at room temperature, vacuum stirring for 2min, and sealing for storage. Among them, the mass ratio of polyurethane prepolymer, carbon black, plasticizer, CHBPE, DBTDL, TEA, nano calcium carbonate and heavy calcium carbonate is 50:35:25:5:0.05:0.2:2:2; the content of CHBPE, DBTDL and TEA in the sealant system is equivalent to the content of CHBPE, DBTDL and TEA in the CHBPE-DBTDL-TEA system in Example 1. After the polyurethane sealant is injected into the mold and cured at room temperature for 72h, its mechanical properties are measured.

[0032] Comparative Example 1-2

[0033] At room temperature, diisononyl phthalate and carbon black (specific surface area 75m 2 / g), nano calcium carbonate (particle size 40-60nm) and heavy calcium carbonate (particle size 6.5μm), vacuum stirring for 50min, then adding DBTDL and TEA respectively at room temperature, vacuum stirring for 2min, and sealing for storage. Among them, the mass ratio of polyurethane prepolymer, carbon black, plasticizer, DBTDL, TEA, nano calcium carbonate and heavy calcium carbonate is 50:35:25:0.05:0.2:2:2; the content of DBTDL and TEA in the sealant system is equivalent to the content of DBTDL and TEA in the CHBPE-DBTDL-TEA system in Example 1. After the polyurethane sealant is injected into the mold and cured at room temperature for 72h, its mechanical properties are measured.

[0034] Table 1 shows the performance parameters of the polyurethane sealant in Example 1, Comparative Example 1-1 and Comparative Example 1-2. Compared with Comparative Examples 1-1 and 1-2, Example 1 has high tensile strength, elongation at break and tear strength, which shows that Example 1 has excellent comprehensive mechanical properties. The Shore hardness of the sealant in Example 1 is slightly lower than that of Comparative Examples 1-1 and 1-2, which shows that the introduction of CHBPE-DBTDL-TEA will not increase the hardness of the polyurethane. The surface drying time of Example 1 is slightly longer than that of Comparative Examples 1-1 and 1-2, but the effect is not significant. The storage period of Example 1 is significantly extended by 127 days and 147 days compared with the storage period of Comparative Examples 1-1 and 1-2, which shows that the hyperbranched polyester system loaded with a catalyst / promoter system can significantly extend the storage period of a one-component polyurethane sealant. Compared with Comparative Examples 1-1 and 1-2, the main reason why the polyurethane sealant in Example 1 exhibits excellent mechanical properties is that the hyperbranched polyester loaded with the catalyst / promoter system can slowly release the catalyst system, which can avoid rapid gelation of the polyurethane system in local areas and fully ensure the uniform curing of the polyurethane system; the surface drying time of Example 1 is slightly longer than that of Comparative Examples 1-1 and 1-2, mainly because the hyperbranched polyester system slowly releases the catalyst / promoter system under controlled conditions; the storage period of Example 1 is significantly longer than that of Comparative Examples 1-1 and 1-2, mainly because the branched structure of the hyperbranched polyester can effectively avoid contact between the catalyst / promoter system and the polyurethane system, thereby extending the storage period of the polyurethane component. By comparing Examples 1-1 and 1-2, it can be found that the introduction of the hyperbranched polyester component can improve the mechanical properties of the polyurethane system to a certain extent, because the hyperbranched polyester system can act as a dispersed filler as a second phase, such as Figure 3 It shows that the dispersibility of the fillers in Example 1 and Comparative Example 1-1 is better than that in Comparative Example 1-2; the hyperbranched polyester component can also play a toughening or plasticizing role due to its branched structure.

[0035]

[0036] a,b : According to GB / T 528-2009 standard, the test was carried out using a universal tensile machine.

[0037] c :According to GB / T 529-2008 standard, the test was carried out using a universal tensile machine.

[0038] d :According to GB / T 531.1-2008 standard, Shore hardness tester was used for measurement.

[0039] e: Test the surface drying time according to GB / T 13477.5-2002 standard.

[0040] f :The storage period is determined according to GB / T 7123.2-2002 standard.

[0041] Example 2

[0042] (1) Synthesis of hyperbranched polyester hybrid system loaded with catalyst / promoter system

[0043] Add the catalyst / accelerator system DBTDL / diethylenetriamine (DETA) to 1 kg of hydroxyl-terminated aliphatic hyperbranched polyester (OHBPE) (HyPer H20, molecular weight 2600), stir at room temperature for 0.5 h, then heat to 50°C and stir for 1 h to obtain the OHBPE system loaded with DBTDL / DETA system (OHBPE-DBTDL-DETA). The mass ratio of OHBPE, DBTDL and DETA is 8.2:0.2:1.6.

[0044] (2) Preparation of one-component polyurethane sealant

[0045] At room temperature, epoxy resin (E-51) was added to MDI polyurethane prepolymer (HC-2285N, -NCO content 6.4%), and the mixture was reacted at 120°C for 30 min. Then, diisononyl phthalate and carbon black (specific surface area 75 m 2 / g), calcium carbonate (particle size: 40-60nm), heavy calcium carbonate (particle size 6.5μm) and coupling agent γ-aminopropyl triethoxysilane, vacuum stirred at room temperature for 40min, then added OHBPE-DBTDL-DETA at room temperature, vacuum stirred for 1min, and a single-component polyurethane sealant system was obtained, which was sealed and stored for use. Before use, the sealant was preheated at 80°C for 2min, injected into the mold, and cured at room temperature for 72h to obtain a polyurethane sealant with excellent mechanical properties. The mass ratio of polyurethane prepolymer, carbon black, plasticizer, OHBPE-DBTDL-DETA, epoxy resin, calcium carbonate, heavy calcium carbonate and coupling agent is 100:60:40:10:25:5:5:1.

[0046] Comparative Example 2-1

[0047] At room temperature, epoxy resin (E-51) was added to MDI polyurethane prepolymer (HC-2285N, -NCO content 6.4%), and the mixture was reacted at 120°C for 30 min. Then, diisononyl phthalate and carbon black (specific surface area 75 m 2 / g), calcium carbonate (particle size: 40-60nm), heavy calcium (particle size 6.5μm) and coupling agent γ-aminopropyl triethoxysilane, vacuum stirred at room temperature for 40min, then added OHBPE, DBTDL, DETA at room temperature, vacuum stirred for 1min, and a single-component polyurethane sealant system was obtained, which was sealed and stored for use. Among them, the polyurethane prepolymer, carbon black, plasticizer, OHBPE, DBTDL, DETA, epoxy resin, calcium carbonate, heavy calcium and coupling agent = 100:60:40:8.2:0.2:1.6:25:5:5:1. The content of OHBPE, DBTDL and DTEA in the sealant system is equivalent to the content of OHBPE, DBTDL and DETA in the OHBPE-DBTDL-DETA system in Example 2. After the polyurethane sealant is injected into the mold and cured at room temperature for 72h, its mechanical properties are measured.

[0048] Comparative Example 2-2

[0049] At room temperature, epoxy resin (E-51) was added to MDI polyurethane prepolymer (HC-2285N, -NCO content 6.4%), and the mixture was reacted at 120°C for 30 min. Then, diisononyl phthalate and carbon black (specific surface area 75 m 2 / g), calcium carbonate (particle size: 40-60nm), heavy calcium (particle size 6.5μm) and coupling agent γ-aminopropyltriethoxysilane, vacuum stirred at room temperature for 40min, then DBTDL and DETA were added at room temperature, vacuum stirred for 1min, and a single-component polyurethane sealant system was obtained, which was sealed and stored for use. Among them, polyurethane prepolymer, carbon black, plasticizer, DBTDL, DETA, epoxy resin, calcium carbonate, heavy calcium and coupling agent = 100:60:40:0.2:1.6:25:5:5:1. The content of DBTDL and DTEA in the sealant system is equivalent to the content of DBTDL and DETA in the OHBPE-DBTDL-DETA system in Example 2. After the polyurethane sealant is injected into the mold and cured at room temperature for 72h, its mechanical properties are measured.

[0050] Table 2 shows the performance parameters of the polyurethane sealant in Example 2, Comparative Example 2-1 and Comparative Example 2-2. Compared with Comparative Examples 2-1 and 2-2, Example 2 has higher tensile strength, elongation at break and tear strength, which shows that Example 2 has excellent comprehensive mechanical properties. The Shore hardness of Example 2 is close to that of Comparative Examples 2-1 and 2-2, which shows that the introduction of the hyperbranched polymer system of the catalyst / promoter system will not significantly affect the hardness of the polyurethane. However, the surface drying time of Example 2 is longer than that of Comparative Examples 2-1 and 2-2, which may be due to the slow release of the catalyst / promoter system. The storage period of Example 2 is significantly extended by 145 days and 159 days compared with the storage period of Comparative Examples 2-1 and 2-2, which shows that the hyperbranched polymer system of the catalyst / promoter system can significantly extend the storage period of the single-component polyurethane sealant. Compared with Comparative Examples 2-1 and 2-2, the main reason why the polyurethane sealant in Example 2 exhibits excellent mechanical properties is that the hyperbranched polymer loaded with the catalyst / accelerator system can slowly release the catalyst / accelerator system, which can avoid rapid gelation in local areas of the polyurethane system and fully ensure uniform curing of the polyurethane system; the storage time of Example 2 is longer than that of Comparative Examples 2-1 and 2-2 mainly because the branched structure of the hyperbranched polyester can effectively avoid contact between the catalyst / accelerator system and the polyurethane system, thereby playing a role in extending the storage period of the polyurethane component and playing a role in controlling the release of the catalyst system and controlling the curing reaction of the polyurethane system. By comparing Examples 2-1 and 2-2, it can be found that the introduction of the hyperbranched polyester component can improve the mechanical properties of the polyurethane system to a certain extent, because the hyperbranched polyester system can act as a second phase to disperse fillers and plasticizers.

[0051]

[0052] Example 3

[0053] (1) Synthesis of hyperbranched polyester hybrid system supported by catalyst system

[0054] Catalyst DBTDL was added to 1 kg of carboxyl terminated aromatic hyperbranched polyester (CHBPE) (hyperc20, molecular weight 5200), and stirred at 60°C for 0.5 h to obtain a carboxyl terminated aromatic hyperbranched polyester system loaded with DBTDL (CHBPE-DBTDL), wherein the mass ratio of carboxyl terminated hyperbranched polyester to DBTDL was 5:0.2.

[0055] (2) Preparation of one-component polyurethane sealant

[0056] At room temperature, dioctyl adipate and carbon black (specific surface area 75m 2 / g), vacuum stirred for 50min at room temperature, then CHBPE-DBTDL was added at room temperature and vacuum stirred for 1min to obtain a single-component polyurethane sealant, which was sealed and stored for later use. Before use, the sealant was ultrasonicated at 200W for 5min, injected into the mold and cured at room temperature for 72h to obtain a urethane sealant with excellent mechanical properties. Among them, the mass ratio of polyurethane prepolymer, carbon black, plasticizer and CHBPE-DBTDL is 50:20:20:5.

[0057] Comparative Example 3-1

[0058] At room temperature, dioctyl adipate and carbon black (specific surface area 75m 2 / g), vacuum stirred for 50min at room temperature, then DBTDL and CHBPE were added at room temperature, vacuum stirred for 1min, and a single-component polyurethane was obtained, which was sealed and stored for later use. Among them, the mass ratio of polyurethane prepolymer, carbon black, plasticizer, CHBPE, and DBTDL was 50:20:20:4.81:0.19. The contents of CHBPE and DBTDL in the sealant corresponded to the contents of CHBPE and DBTDL in CHBPE-DBTDL in Example 3, respectively. After the polyurethane sealant was injected into the mold and cured at room temperature for 72h, its mechanical properties were measured.

[0059] Comparative Example 3-2

[0060] At room temperature, dioctyl adipate and carbon black (specific surface area 75m 2 / g), vacuum stirred for 50min at room temperature, then DBTDL was added at room temperature and vacuum stirred for 1min to obtain a single-component polyurethane, which was sealed and stored for later use. The mass ratio of polyurethane prepolymer, carbon black, plasticizer and DBTDL was 50:20:20:0.19. The content of DBTDL in the sealant corresponds to the content of DBTDL in CHBPE-DBTDL in Example 3. After the polyurethane sealant was injected into the mold and cured at room temperature for 72h, its mechanical properties were measured.

[0061] Table 3 shows the performance parameters of the polyurethane sealant in Example 3, Comparative Example 3-1 and Comparative Example 3-2. Compared with Comparative Examples 3-1 and 3-2, Example 3 has higher tensile strength, elongation at break and tear strength, which shows that Example 3 has excellent comprehensive mechanical properties. The Shore hardness of Example 3 is close to that of Comparative Examples 3-1 and 3-2, which shows that the introduction of the hyperbranched polymer system of the supported catalyst system will not significantly affect the hardness of the polyurethane. However, the surface drying time of Example 3 is longer than that of Comparative Examples 3-1 and 3-2, especially the storage period of Example 3 is significantly extended by 197 days and 209 days compared with the storage period of Comparative Examples 3-1 and 3-2, which shows that the hyperbranched polymer system of the supported catalyst system can significantly extend the storage period of the single-component polyurethane sealant. Compared with Comparative Examples 3-1 and 3-2, the main reason why the polyurethane sealant in Example 3 exhibits excellent mechanical properties is that the hyperbranched polymer loaded with the catalyst system can slowly release the catalyst system, which can avoid rapid gelation in local areas of the polyurethane system and fully ensure uniform curing of the polyurethane system; the main reason why the storage time of Example 3 is longer than that of Comparative Examples 3-1 and 3-2 is that the branched structure of the hyperbranched polyester can effectively avoid contact between the catalyst and the polyurethane system, thereby extending the storage period of the polyurethane component, and achieving the purpose of slow release of the catalyst system and controlling the curing reaction of the polyurethane system. By comparing Examples 3-1 and 3-2, it can be found that the introduction of the hyperbranched polyester component can improve the mechanical properties of the polyurethane system to a certain extent, because the hyperbranched polyester system can serve as a second phase to disperse fillers and plasticize polyurethane.

[0062]

[0063] Example 4

[0064] (1) Synthesis of hyperbranched polyester hybrid system loaded with catalyst / promoter system

[0065] The catalyst system dibutyltin dilaurate (DBTDL) / piperazine (PIP) was added to 1 kg of carboxyl-terminated aromatic hyperbranched polyester (CHBPE) (hyperc20, molecular weight 5200), stirred at room temperature for 0.5 h, then heated to 80°C and stirred for 1 h to obtain a catalyst / promoter-loaded hyperbranched polyester hybrid system (CPHBPE-DBTDL-PIP). The mass ratio of CHBPE, DBTDL, and PIP was 9.4:0.1:0.5.

[0066] (2) Preparation of one-component polyurethane sealant

[0067] At room temperature, epoxy resin (E-44) was added to polytetrahydrofuran polyurethane prepolymer (HJ2195, -NCO content 6%), stirred at 100°C for 30 min, and then diisononyl phthalate and carbon black (specific surface area 75 m 2 / g), calcium carbonate (particle size: 40-60nm) and heavy calcium carbonate (particle size 6.5μm), vacuum stirring for about 20min, then adding CHBPE-DBTDL-PIP at room temperature, vacuum stirring for 5min, sealing and storing for later use. Before use, the sealant is preheated at 100°C for 5min, injected into the mold and cured at room temperature for 72h to obtain a polyurethane sealant with excellent mechanical properties. The mass ratio of polyurethane prepolymer, carbon black, plasticizer, CHBPE-DBTDL-PIP, epoxy resin, calcium carbonate and heavy calcium carbonate is 100:45:20:10:15:4:4.

[0068] Comparative Example 4-1

[0069] At room temperature, epoxy resin (E-44) was added to polytetrahydrofuran polyurethane prepolymer (HJ2195, -NCO content 6%), stirred at 100°C for 30 min, and then diisononyl phthalate and carbon black (specific surface area 75 m 2 / g), calcium carbonate (particle size: 40-60nm) and heavy calcium (particle size 6.5μm), vacuum stirring for about 20min, then adding CHBPE, DBTDL, PIP at room temperature, vacuum stirring for 5min, sealing and storing for standby use. Among them, the mass ratio of polyurethane prepolymer, carbon black, plasticizer, CHBPE, DBTDL, PIP, epoxy resin, calcium carbonate, and heavy calcium is 100:45:20:9.4:0.1:0.5:15:4:4. The contents of CHBPE, DBTDL, and PIP in the sealant correspond to the contents of CHBPE, DBTDL, and PIP in CHBPE-DBTDL in Example 4, respectively. After the polyurethane sealant is injected into the mold and cured at room temperature for 72h, its mechanical properties are measured.

[0070] Comparative Example 4-2

[0071] At room temperature, epoxy resin (E-44) was added to polytetrahydrofuran polyurethane prepolymer (HJ2195, -NCO content 6%), stirred at 100°C for 30 min, and then diisononyl phthalate and carbon black (specific surface area 75 m 2 / g), calcium carbonate (particle size: 40-60nm) and heavy calcium (particle size 6.5μm), vacuum stirring for about 20min, then adding DBTDL and PIP at room temperature, vacuum stirring for 5min, sealing and storing for standby use. Among them, the mass ratio of polyurethane prepolymer, carbon black, plasticizer, DBTDL, PIP, epoxy resin, calcium carbonate, and heavy calcium is 100:45:20:0.1:0.5:15:4:4. The contents of DBTDL and PIP in the sealant correspond to the contents of DBTDL and PIP of CHBPE-DBTDL in Example 4, respectively. After the polyurethane sealant is injected into the mold and cured at room temperature for 72h, its mechanical properties are measured.

[0072] Table 4 shows the performance parameters of the polyurethane sealant in Example 4, Comparative Example 4-1 and Comparative Example 4-2. Compared with Comparative Examples 4-1 and 4-2, Example 4 has higher tensile strength, elongation at break and tear strength, which shows that Example 4 has excellent comprehensive mechanical properties. The Shore hardness of Example 4 is close to that of Comparative Examples 4-1 and 4-2, which shows that the introduction of the hyperbranched polymer system of the catalyst / promoter system will not significantly affect the hardness of the polyurethane. However, the surface drying time of Example 4 is longer than that of Comparative Examples 4-1 and 4-2, especially the storage period of Example 4 is significantly extended by 168 days and 181 days compared with the storage period of Comparative Examples 4-1 and 4-2, which shows that the hyperbranched polymer system of the catalyst / promoter system can significantly extend the storage period of the single-component polyurethane sealant. Compared with Comparative Examples 4-1 and 4-2, the main reason why the polyurethane sealant in Example 4 exhibits excellent mechanical properties is that the hyperbranched polymer loaded with the catalyst / accelerator system can slowly release the catalyst / accelerator system, which can avoid rapid gelation in local areas of the polyurethane system and fully ensure uniform curing of the polyurethane system; the main reason why the storage period of Example 4 is significantly longer than that of Comparative Examples 4-1 and 4-2 is that the branched structure of the hyperbranched polyester can effectively avoid contact between the catalyst / accelerator system and the polyurethane system, thereby extending the storage period of the polyurethane component and achieving the purpose of controlling the release of the catalyst / accelerator system and controlling the curing reaction of the polyurethane system. By comparing Examples 4-1 and 4-2, it can be found that the introduction of the hyperbranched polyester component can improve the mechanical properties of the polyurethane system to a certain extent, because the hyperbranched polyester system can serve as a second phase to disperse fillers and plasticize.

[0073]

[0074] The invention utilizes the structural characteristics of a hyperbranched polymer. On the one hand, the cavity structure formed by the hyperbranched structure of the polymer and the self-assembled vesicle structure are utilized to store and protect the catalyst / accelerator system. On the other hand, the structure of the hyperbranched polymer is utilized to control the release of the catalyst / accelerator, thereby extending the storage period of the polyurethane sealant and controlling the reaction of the polyurethane system, and finally obtaining a single-component polyurethane sealant system with high storage stability and controllable curing reaction.

Claims

1. A one-component polyurethane sealant system with controlled curing reaction and high storage stability, characterized in that: The components and mass ratio of the one-component polyurethane sealant system with high storage stability and controllable curing reaction are as follows: polyurethane prepolymer, carbon black, plasticizer, hyperbranched polymer system loaded with catalyst / accelerator system, epoxy resin, calcium carbonate, heavy calcium, coupling agent = (50-100): (20-60): (20-40): (5-10): (0-25): (0-5): (0-5): (0-1); the mass ratio of catalyst to accelerator is (1-4): (0-20); the polyurethane prepolymer is a polyurethane prepolymer with different contents of -NCO end-capping; the preparation process of the hyperbranched polymer system loaded with catalyst / accelerator system is as follows: adding the catalyst / accelerator system to the hyperbranched polymer, controlling the reaction temperature to be room temperature to 80°C, stirring for 0.5 to 4 hours, and obtaining the hyperbranched polymer system loaded with catalyst / accelerator system.

2. The one-component polyurethane sealant system with controlled curing reaction and high storage stability according to claim 1, characterized in that: The mass ratio of the hyperbranched polymer and the catalyst / accelerator system is 100:(1-25); the catalyst is an organic tin catalyst; and the accelerator is a tertiary amine.

3. The one-component polyurethane sealant system with controlled curing reaction and high storage stability according to claim 1, characterized in that: The plasticizer includes dioctyl phthalate, dibutyl phthalate, dioctyl sebacate, dioctyl adipate, and diisononyl phthalate; the epoxy resin includes one or more of glycidyl ether epoxy resin, glycidyl ester epoxy resin, glycidyl amine epoxy resin, alicyclic epoxy resin, and linear aliphatic epoxy compound; and the coupling agent is a silane coupling agent.

4. The one-component polyurethane sealant system with controlled curing reaction and high storage stability according to claim 1, characterized in that: The hyperbranched polymer is a functional group-terminated hyperbranched polyester, a functional group-terminated hyperbranched polyether, a functional group-terminated hyperbranched polyamide ester, a functional group-terminated hyperbranched polyamide, or a functional group-terminated hyperbranched polyurethane; the functional group is a carboxyl group, a hydroxyl group or an amino group.

5. The method for preparing a one-component polyurethane sealant system with controlled curing reaction and high storage stability according to claim 1, characterized in that: The polyurethane prepolymer, carbon black, plasticizer, hyperbranched polymer system loaded with catalyst / accelerator system, epoxy resin, calcium carbonate, heavy calcium and coupling agent are mixed to obtain a single-component polyurethane sealant system with high storage stability and controllable curing reaction.

6. The method for preparing the one-component polyurethane sealant system with controlled curing reaction and high storage stability according to claim 5, characterized in that: At room temperature, epoxy resin is added to the polyurethane prepolymer, and after stirring, plasticizer, carbon black, calcium carbonate and heavy calcium are added, and stirring is continued. Then, at room temperature, a hyperbranched polymer system loaded with a catalyst / accelerator system is added, and vacuum stirring is performed to obtain a single-component polyurethane sealant system with a controllable curing reaction and high storage stability.

7. Use of the one-component polyurethane sealant system with controlled curing reaction and high storage stability according to claim 1 in the preparation of polyurethane sealants.

8. A polyurethane sealant, characterized in that: The high storage stability single-component polyurethane sealant system with controllable curing reaction as claimed in claim 1 is cured at room temperature.

9. Use of a hyperbranched polymer system loaded with a catalyst / accelerator system in the preparation of a one-component polyurethane sealant system with high storage stability and controllable curing reaction as claimed in claim 1, characterized in that: The preparation process of the hyperbranched polymer system loaded with a catalyst / promoter system is as follows: adding the catalyst / promoter system to the hyperbranched polymer, controlling the reaction temperature to be room temperature to 80° C., stirring for 0.5 to 4 hours, and obtaining the hyperbranched polymer system loaded with a catalyst / promoter system.

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