Normal-temperature high-strength pouring sealant as well as preparation method and application thereof

Abstract

The invention provides a normal-temperature high-strength pouring sealant. The normal-temperature high-strength pouring sealant is mainly prepared from the following components in parts by weight: 1-8 parts of a sulfydryl silane coupling agent, 1-5 parts of Desmodur RFE, 40-65 parts of dry silane, 15-40 parts of silicone oil and 5-15 parts of fumed silica. The invention also provides a preparation method of the normal-temperature high-strength pouring sealant. The invention also provides application of the normal-temperature high-strength pouring sealant as a building and road building material in the building field, road maintenance or road construction. According to the normal-temperature high-strength pouring sealant provided by the invention, an isocyanate group in Desmodur RFE can react with a sulfydryl group in a sulfydryl silane coupling agent to generate mercaptan carbamate, the isocyanate group and a hydroxyl group on dry silane can generate a carbamic acid ester structure, and due to the fact that the Desmodur RFE is of an adamantane type structure, a benzene ring and carbamic acid ester are formed, so that the normal-temperature high-strength pouring sealant has the advantages that the normal-temperature high-strength pouring sealant is formed; and a hard section and soft section three-dimensional combined structure arranged by silicon-oxygen bonds has extremely high wear resistance and impact resistance.

Description

Technical Field

[0001] The invention relates to the field of building and road materials, and in particular to a room temperature high-strength potting adhesive and a preparation method and application thereof. Background Art

[0002] Cracks often appear on the road surface during use. These cracks not only affect the appearance of the road surface, but more seriously threaten traffic safety. Therefore, it is necessary to repair the cracks in the road surface in time. Road potting glue, also known as road crack sealant or road filler, is a road repair material, mainly used for local repair and sealing cracks in concrete pavements. Since pavement crack disease is a common problem, many countries have conducted a lot of research. Potting glue, as an effective process, is of great help to the construction quality of roads. Potting glue can prevent moisture and debris from entering the pavement structure layer through cracks, thereby avoiding further damage to the base layer and maintaining the integrity of the pavement; it can be waterproof and anti-seepage; timely and effective crack repair can reduce driving bumps caused by potholes and improve the smoothness of the road surface, which is conducive to improving driving safety and comfort.

[0003] Early potting glue mainly used traditional materials such as asphalt, SBS modifier, stabilizer, anti-aging agent, etc., but these materials have some shortcomings in performance, such as poor adhesion, easy aging, impact resistance, cumbersome construction, etc. With the continuous advancement of material science and technology, potting glue technology has also developed rapidly. However, potting glue still has defects such as slow curing speed and low curing strength at room temperature.

[0004] The room temperature type high strength potting adhesive of the present invention has the characteristics of high curing strength and strong impact resistance, fast room temperature curing speed and convenient construction, and can be widely used in the fields of construction, transportation, electronics, automobiles, aerospace, etc. Summary of the invention

[0005] The purpose of the present invention is to provide a room temperature high strength potting glue and its preparation method and application in view of the deficiencies of the prior art. The present invention realizes room temperature curing of siloxane by introducing a dual system reactive curing crosslinking agent, while improving the adhesion and mechanical strength of the potting glue.

[0006] The technical solution of the present invention is achieved in this way: A normal temperature type high strength potting glue is mainly prepared from the following components in parts by weight: 1 to 8 parts of mercaptosilane coupling agent, 1 to 5 parts of Desmodur RFE, 40 to 65 parts of dry silane, 15 to 40 parts of silicone oil, and 5 to 15 parts of fumed silica. Of course, depending on the specific application environment, masterbatch, mildew inhibitor, etc. can be appropriately added. Preferably, a normal temperature type high strength potting glue is mainly prepared from the following components in parts by weight: 4 to 7 parts of mercaptosilane coupling agent, 3 to 4 parts of Desmodur RFE, 55 to 60 parts of dry silane, 18 to 25 parts of silicone oil, and 10 to 13 parts of fumed silica. Most preferably, a normal temperature type high strength potting glue is mainly prepared from the following components in parts by weight: 5 parts of mercaptosilane coupling agent, 4 parts of Desmodur RFE, 56 parts of dry silane, 24 parts of silicone oil, and 11 parts of fumed silica.

[0007] In the room temperature high strength potting glue as described above, the mercaptosilane coupling agent is one or more of 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane, and 3-mercaptopropyltrimethoxysilane. Under this condition, the mercaptosilane coupling agent can react with the active dry silane to effectively improve the adhesion of the system and increase the crosslinking density, and react with the isocyanate group of Desmodur RFE to generate carbamic acid thiol ester. Preferably, the mercaptosilane coupling agent is 3-mercaptopropylmethyldimethoxysilane.

[0008] As described above, the room temperature high-strength potting glue, the Desmodur RFE isocyanate content is 7-8%. Under this condition, the isocyanate group in the Desmodur RFE can react with the mercapto group in the mercaptosilane coupling agent to form an ester-sulfur bond, and its isocyanate group can also react with the hydroxyl group on the dry silane to form a carbamate structure. Because it itself has an "adamantane" structure, it forms a benzene ring, a carbamate, a hard segment arranged with a silicon oxygen bond, and a three-dimensional combination structure of a soft segment, which has extremely strong wear resistance and impact resistance. The sulfur-phosphorus bond of Desmodur RFE has good adhesion to inorganic materials. Preferably, DesmodurRFE is purchased from Covestro Polymer (China) Co., Ltd., and its isocyanate content is 7.2±0.2 (%).

[0009] In the room temperature high strength potting adhesive as described above, the dry silane is vinyl alkoxysilane grafted polyethylene. Preferably, the dry silane is dry silane XLM70-EVA purchased from Nanjing Nengde New Material Technology Co., Ltd. Under this condition, the dry silane XLM70-EVA itself has excellent low temperature resistance and flexibility. During use, under the action of moisture, on the one hand, the cross-linking reaction between siloxane molecules is completed by removing the small molecule structure, and on the other hand, the reaction intermediate silanol can form a carbamate structure with the isocyanate group, thereby strengthening the cross-linking density and increasing the strength and impact resistance of the curing system.

[0010] In the room temperature high strength potting glue as described above, the silicone oil is one of dimethyl silicone oils with a viscosity of 50cps, 100cps or 200cps at 25°C or a mixture thereof. Under this condition, the silicone oil can not only adjust the viscosity of the sealant, improve the fluidity of the engineering construction and the lubricity to the adherend, but also improve the adhesion of the potting glue, and can react with the active groups in the potting glue to form a cross-linked network structure, thereby improving the adhesion and shear resistance of the potting glue and enhancing the sealing performance. Preferably, the silicone oil is dimethyl silicone oil with a viscosity of 200cps at 25°C.

[0011] The room temperature high strength potting glue as described above, wherein the specific surface area of ​​the fumed silica is 360 to 430 m 2 / g. Under this condition, the fumed silica can increase the strength, hardness and wear resistance of the potting compound, improve weather resistance and produce an excellent synergistic effect due to its high specific surface area and excellent reinforcement effect. Preferably, the fumed silica is purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd., and its specific surface area is 395±25 m 2 / g.

[0012] Based on the same inventive concept, the present invention provides a method for preparing a room temperature high-strength potting adhesive, which is characterized by comprising the following steps: Step 1, put silicone oil and dry silane into a vacuum kneader, set the temperature to 120-150°C, stir and disperse evenly, the dispersion time is 20-50min, and the vacuum pressure is -80-95 kPa to obtain material 1; preferably, set the temperature to 120-140°C, stir and disperse evenly, the dispersion time is 20-50min, and the vacuum pressure is -95 kPa; most preferably, set the temperature to 120°C, stir and disperse evenly, the dispersion time is 30min, and the vacuum pressure is -95 kPa; Step 2, adding fumed silica to material 1 according to a set ratio, maintaining the temperature at 120-150°C in a vacuum kneader, stirring and dispersing evenly, the dispersion time is 20-150min, and the vacuum pressure is -80-95 kPa to obtain material 2; it should be understood that in order to avoid powder agglomeration, fumed silica can be added in batches; preferably, the temperature is maintained at 120-130°C, the dispersion is stirred and dispersed evenly, the dispersion time is 30-50min, and the vacuum pressure is -95 kPa; most preferably, the temperature is maintained at 130°C, the dispersion is stirred and dispersed evenly, the dispersion time is 50min, and the vacuum pressure is -95 kPa; Step 3, cool material 2 to room temperature and transfer it to a vacuum reactor, add a mercaptosilane coupling agent according to a set ratio, stir and disperse evenly, set the temperature to 20-40°C, the stirring time to 20-150min, and the vacuum degree to -80-95kPa to obtain material 3; preferably, set the temperature to 25°C, the stirring time to 90-120min, and the vacuum degree to -95 kPa; most preferably, set the temperature to 25°C, the stirring time to 120min, and the vacuum degree to -95 kPa; Step 4: Add Desmodur RFE to material 3 in a set ratio, set the temperature to 20-40°C, stir and disperse evenly, stir for 20-40 minutes, and set the vacuum degree to -80-95 kPa. After filtering through a 60-mesh filter, vacuum pack the mixture to obtain a room temperature high-strength potting glue. Preferably, set the temperature to 25°C, stir and disperse evenly, stir for 30-40 minutes, and set the vacuum degree to -95 kPa; most preferably, set the temperature to 25°C, stir and disperse evenly, stir for 40 minutes, and set the vacuum degree to -95 kPa.

[0013] Preferably, the above silicone oil, dry silane, fumed silica, mercaptosilane coupling agent, and Desmodur RFE are all dried to remove water.

[0014] Based on the same inventive concept, the present invention provides the use of the room temperature high-strength potting glue as described above or the room temperature high-strength potting glue prepared by the preparation method as described above as a building or road building material in the construction field, road maintenance or road construction.

[0015] The working principle of the present invention is as follows: the isocyanate group in Desmodur RFE can react with the mercapto group in the mercaptosilane coupling agent to generate carbamate thiol ester, and the isocyanate group can also react with the hydroxyl group on the dry silane to form a carbamate structure. Because it has an "adamantane" structure, it forms a three-dimensional combination structure of hard segments and soft segments arranged with benzene rings, carbamates, and silicon oxygen bonds, and has extremely strong wear resistance and impact resistance. The sulfur-phosphorus bond of Desmodur RFE has good adhesion to the surface of inorganic materials and aggregates, and the mercaptosilane coupling agent can react with the active dry silane to effectively improve the adhesion of the system and increase the crosslinking density. Silicone oil can not only adjust the viscosity of the sealant, improve the fluidity of engineering construction and the lubricity to the adherend, but also improve the adhesion of the potting glue, and can react with the active groups in the potting glue to form a crosslinked network structure, thereby improving the adhesion and shear resistance of the potting glue and enhancing the sealing performance. Moreover, the silicone oil molecular chain contains a silicon oxygen bond, which has hydrophobic properties, thereby improving the water resistance of the potting compound and protecting cracks from moisture erosion. The fumed silica selected by the present invention can increase the strength, hardness and wear resistance of the potting compound due to its high specific surface area and excellent reinforcement effect, improve weather resistance and produce excellent synergistic effects. Dry silane XLM70 itself has excellent low temperature resistance and flexibility. Under the action of moisture during use, on the one hand, by removing the small molecule structure, the cross-linking reaction between siloxane molecules is completed, and on the other hand, its reaction intermediate silanol can form a carbamate structure with an isocyanate group, strengthen the cross-linking density, and increase the strength and impact resistance of the curing system. At the same time, moisture can also directly react with the isocyanate group of Desmodur RFE to achieve the effect of chain extension, further increase the cohesive energy of the system, improve the bonding strength, and under the synergistic effect of the above several materials, finally form a potting compound with a molecular network structure and a high curing efficiency.

[0016] The beneficial effects of the present invention are: 1. The present invention provides a room temperature high-strength potting adhesive. The isocyanate group in Desmodur RFE can react with the mercapto group in the mercaptosilane coupling agent to form carbamate thiol ester. The isocyanate group can also react with the hydroxyl group on the dry silane to form a carbamate structure. Because it has an "adamantane" structure, it forms a three-dimensional combination structure of hard segments and soft segments arranged with benzene rings, carbamates, and silicon-oxygen bonds, and has extremely strong wear resistance and impact resistance.

[0017] 2. The present invention provides a room temperature high strength potting adhesive. The dry silane XLM70 itself has excellent low temperature resistance and flexibility. Under the action of moisture during use, on the one hand, the cross-linking reaction between siloxane molecules is completed by removing the small molecular structure. On the other hand, its reaction intermediate silanol can form a carbamate structure with the isocyanate group to strengthen the cross-linking density and increase the strength and impact resistance of the curing system. At the same time, moisture can also directly react with the isocyanate group of Desmodur RFE to achieve the effect of chain extension, further increase the cohesive energy of the system, and improve the bonding strength. The room temperature high strength potting adhesive provided by the present invention has the characteristics of multi-system curing and high curing efficiency.

[0018] 3. The present invention provides a room temperature high strength potting glue, the surface drying time of which is 41 to 50 minutes. The tensile bond strength (23°C) is 3.2-3.7 MPa, the Shore hardness is 42-49 HA, and the tensile bond strength elongation at 23°C is 411-489%. It has a faster surface drying time and better tensile bond strength and tensile bond elongation, indicating that the potting glue provided by the present invention has the characteristics of fast curing speed at room temperature and high bonding strength. DETAILED DESCRIPTION

[0019] The following will combine the contents in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0020] Unless otherwise defined, all technical and scientific terms used in this specification have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used in this specification includes any and all combinations of one or more of the related listed items.

[0021] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0022] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0023] In the following examples and comparative examples, 3-mercaptopropylmethyldimethoxysilane was purchased from Nanjing Nengde New Material Technology Co., Ltd., and its CAS number is 31001-77-1. 3-Mercaptopropyltriethoxysilane was purchased from Nanjing Nengde New Material Technology Co., Ltd., and its CAS number is 14814-09-6. 3-Mercaptopropyltrimethoxysilane was purchased from Nanjing Nengde New Material Technology Co., Ltd., and its CAS number is 4420-74-0. Dry silane was purchased from Nanjing Nengde New Material Technology Co., Ltd., and its model number is XLM70-EVA, hereinafter referred to as "dry silane XLM70". Silicone oil was purchased from Dow Corning (China) Silicones Co., Ltd.'s dimethyl silicone oil, and its CAS number is 63148-62-9. Fumed silica was purchased from Sigma-Aldrich (Shanghai) Trading Co., Ltd., and its CAS number is 112945-52-5, with a specific surface area of ​​395±25 m 2 / g. Desmodur RFE was purchased from Covestro Polymers (China) Co., Ltd., and its isocyanate content was 7.2±0.2 (%).

[0024] Embodiment 1: A room temperature high-strength potting adhesive is mainly prepared from the following components in parts by weight: 5 parts of 3-mercaptopropylmethyldimethoxysilane, 4 parts of Desmodur RFE, 56 parts of dry silane XLM70, 24 parts of 200cps dimethyl silicone oil, and 11 parts of fumed silica.

[0025] The preparation method of the above-mentioned room temperature high-strength potting glue is as follows: Step 1: put the dried and dehydrated dimethyl silicone oil and the dried and dehydrated dry silane XLM70 into a vacuum kneader, set the temperature to 120°C, stir and disperse evenly, the dispersion time is 30 minutes, and the vacuum pressure is -95 kPa to obtain material 1; Step 2: Add the dried and dehydrated fumed silica to material 1 in a set ratio, maintain the temperature at 130°C in a vacuum kneader, stir and disperse evenly, the dispersion time is 50 minutes, and the vacuum pressure is -95 kPa to obtain material 2. It should be understood that in order to avoid powder agglomeration, the fumed silica can be added in batches; Step 3, cool material 2 to room temperature and transfer it to a vacuum reactor, add dried and dehydrated 3-mercaptopropylmethyldimethoxysilane according to the set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 120 minutes, and the vacuum degree is -95 kPa to obtain material 3; Step 4: Add the dried and dehydrated Desmodur RFE to material 3 in a set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 40 minutes, and set the vacuum degree to -95 kPa. After filtering through a 60-mesh filter, vacuum pack and obtain a room temperature high-strength potting adhesive.

[0026] Embodiment 2: A room temperature high-strength potting adhesive is mainly prepared from the following components in parts by weight: 7 parts of 3-mercaptopropyltriethoxysilane, 3 parts of Desmodur RFE, 58 parts of dry silane XLM70, 20 parts of 100cps dimethyl silicone oil, and 12 parts of fumed silica.

[0027] The preparation method of the above-mentioned room temperature high-strength potting glue is as follows: Step 1: put the dry dehydrated dimethyl silicone oil and the dry dehydrated dry silane XLM70 into a vacuum kneader, set the temperature to 120°C, stir and disperse evenly, the dispersion time is 40 minutes, and the vacuum pressure is -95 kPa to obtain material 1; Step 2: Add the dried and dehydrated fumed silica to material 1 in a set ratio, maintain the temperature at 120°C in a vacuum kneader, stir and disperse evenly, the dispersion time is 30 minutes, and the vacuum pressure is -95 kPa to obtain material 2. It should be understood that the fumed silica can be added in batches to avoid powder agglomeration.

[0028] Step 3: Cool material 2 to room temperature and transfer it to a vacuum reactor. Add dried and dehydrated 3-mercaptopropyltriethoxysilane according to the set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 100 minutes, and set the vacuum degree to -95 kPa to obtain material 3.

[0029] Step 4: Add the dried and dehydrated Desmodur RFE to material 3 according to the set ratio, and set the temperature to 25°C. Stir and disperse evenly for 40 minutes, with a vacuum degree of -95 kPa. After filtering through a 60-mesh filter, vacuum pack and obtain a room temperature high-strength potting glue.

[0030] Embodiment 3: A room temperature high-strength potting adhesive is mainly prepared from the following components in parts by weight: 5 parts of 3-mercaptopropyltrimethoxysilane, 4 parts of Desmodur RFE, 60 parts of dry silane XLM70, 18 parts of 200cps dimethyl silicone oil, and 13 parts of fumed silica.

[0031] The preparation method of the above-mentioned room temperature high-strength potting glue is as follows: Step 1: put the dried and dehydrated dimethyl silicone oil and the dried and dehydrated dry silane XLM70 into a vacuum kneader, set the temperature to 140°C, stir and disperse evenly, the dispersion time is 30 minutes, and the vacuum pressure is -95 kPa to obtain material 1; Step 2: Add the dried and dehydrated fumed silica to material 1 in a set ratio, maintain the temperature at 130° C. in a vacuum kneader, stir and disperse evenly, the dispersion time is 30 min, and the vacuum pressure is -95 kPa to obtain material 2. It should be understood that the fumed silica can be added in batches to avoid powder agglomeration.

[0032] Step 3: Cool material 2 to room temperature and transfer it to a vacuum reactor. Add dried and dehydrated 3-mercaptopropyltrimethoxysilane according to the set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 120 minutes, and set the vacuum degree to -95 kPa to obtain material 3.

[0033] Step 4: Add the dried and dehydrated Desmodur RFE to material 3 in a set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 40 minutes, and set the vacuum degree to -95 kPa. After filtering through a 60-mesh filter, vacuum pack and obtain a room temperature high-strength potting adhesive.

[0034] Embodiment 4: A room temperature high-strength potting adhesive is mainly prepared from the following components in parts by weight: 4 parts of 3-mercaptopropylmethyldimethoxysilane, 4 parts of Desmodur RFE, 55 parts of dry silane XLM70, 25 parts of 200cps dimethyl silicone oil, and 12 parts of fumed silica.

[0035] The preparation method of the above-mentioned room temperature high-strength potting glue is as follows: Step 1: put the dried and dehydrated dimethyl silicone oil and the dried and dehydrated dry silane XLM70 into a vacuum kneader, set the temperature to 120°C, stir and disperse evenly, the dispersion time is 20 minutes, and the vacuum pressure is -95 kPa to obtain material 1; Step 2: Add the dried and dehydrated fumed silica to material 1 in a set ratio, maintain the temperature at 130° C. in a vacuum kneader, stir and disperse evenly, the dispersion time is 30 min, and the vacuum pressure is -95 kPa to obtain material 2. It should be understood that the fumed silica can be added in batches to avoid powder agglomeration.

[0036] Step 3: Cool material 2 to room temperature and transfer it to a vacuum reactor. Add dried and dehydrated 3-mercaptopropylmethyldimethoxysilane according to the set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 120 minutes, and set the vacuum degree to -95 kPa to obtain material 3.

[0037] Step 4: Add the dried and dehydrated Desmodur RFE to material 3 in a set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 40 minutes, and set the vacuum degree to -95 kPa. After filtering through a 60-mesh filter, vacuum pack and obtain a room temperature high-strength potting adhesive.

[0038] Embodiment 5: A room temperature high-strength potting adhesive is mainly prepared from the following components in parts by weight: 6 parts of 3-mercaptopropylmethyldimethoxysilane, 3 parts of Desmodur RFE, 59 parts of dry silane XLM70, 22 parts of 200cps dimethyl silicone oil, and 10 parts of fumed silica.

[0039] The preparation method of the above-mentioned room temperature high-strength potting glue is as follows: Step 1: put the dried and dehydrated dimethyl silicone oil and the dried and dehydrated dry silane XLM70 into a vacuum kneader, set the temperature to 130°C, stir and disperse evenly, the dispersion time is 50 minutes, and the vacuum pressure is -95 kPa to obtain material 1; Step 2: Add the dried and dehydrated fumed silica to material 1 in a set ratio, maintain the temperature at 130° C. in a vacuum kneader, stir and disperse evenly, the dispersion time is 30 min, and the vacuum pressure is -95 kPa to obtain material 2. It should be understood that the fumed silica can be added in batches to avoid powder agglomeration.

[0040] Step 3: Cool material 2 to room temperature and transfer it to a vacuum reactor. Add dried and dehydrated 3-mercaptopropylmethyldimethoxysilane according to the set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 90 minutes, and set the vacuum degree to -95 kPa to obtain material 3.

[0041] Step 4: Add the dried and dehydrated Desmodur RFE to material 3 in a set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 30 minutes, and set the vacuum degree to -95 kPa. After filtering through a 60-mesh filter, vacuum pack and obtain a room temperature high-strength potting adhesive.

[0042] Comparative Example 1: A potting compound is prepared mainly from the following components in parts by weight: 5 parts of N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane, 4 parts of Desmodur RFE, 56 parts of dry silane XLM70, 24 parts of 200cps dimethyl silicone oil, and 11 parts of fumed silica. N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane is purchased from Dow Corning. The same Desmodur RFE, dry silane XLM70, 200cps dimethyl silicone oil, and fumed silica are used as in Example 1.

[0043] The preparation method of the above-mentioned potting glue is as follows: Step 1: put the dried and dehydrated dimethyl silicone oil and the dried and dehydrated dry silane XLM70 into a vacuum kneader, set the temperature to 120°C, stir and disperse evenly, the dispersion time is 30 minutes, and the vacuum pressure is -95 kPa to obtain material 1; Step 2: Add the dried and dehydrated fumed silica to material 1 in a set ratio, maintain the temperature at 130° C. in a vacuum kneader, stir and disperse evenly, the dispersion time is 50 min, and the vacuum pressure is -95 kPa to obtain material 2. It should be understood that the fumed silica can be added in batches to avoid powder agglomeration.

[0044] Step 3: Cool material 2 to room temperature and transfer it to a vacuum reactor. Add dried and dehydrated N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane according to the set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 120 min, and set the vacuum degree to -95 kPa to obtain material 3.

[0045] Step 4: Add the dried and dehydrated Desmodur RFE to material 3 in a set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 40 minutes, and set the vacuum degree to -95 kPa. After filtering through a 60-mesh filter, vacuum pack and obtain the potting glue.

[0046] Comparative Example 2: A potting compound is mainly prepared from the following components in parts by weight: 5 parts of 3-mercaptopropylmethyldimethoxysilane, 4 parts of hexamethylene diisocyanate (hereinafter referred to as "HDI"), 56 parts of dry silane XLM70, 24 parts of 200cps dimethyl silicone oil, and 11 parts of fumed silica. HDI is purchased from Wanhua Chemical Group Co., Ltd., and its CAS number is 822-06-0; the same 3-mercaptopropylmethyldimethoxysilane, dry silane XLM70, 200cps dimethyl silicone oil, and fumed silica are used as in Example 1.

[0047] The preparation method of the above-mentioned potting glue is as follows: Step 1: put the dried and dehydrated dimethyl silicone oil and the dried and dehydrated dry silane XLM70 into a vacuum kneader, set the temperature to 120°C, stir and disperse evenly, the dispersion time is 30 minutes, and the vacuum pressure is -95 kPa to obtain material 1; Step 2: Add the dried and dehydrated fumed silica to material 1 in a set ratio, maintain the temperature at 130° C. in a vacuum kneader, stir and disperse evenly, the dispersion time is 50 min, and the vacuum pressure is -95 kPa to obtain material 2. It should be understood that the fumed silica can be added in batches to avoid powder agglomeration.

[0048] Step 3: Cool material 2 to room temperature and transfer it to a vacuum reactor. Add dried and dehydrated 3-mercaptopropylmethyldimethoxysilane according to the set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 120 minutes, and set the vacuum degree to -95 kPa to obtain material 3.

[0049] Step 4: Add the dried and dehydrated HDI to material 3 according to the set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 40 minutes, and set the vacuum degree to -95 kPa. After filtering through a 60-mesh filter, vacuum pack and obtain the potting glue.

[0050] Comparative Example 3: A potting compound is mainly prepared from the following components in parts by weight: 5 parts of 3-mercaptopropylmethyldimethoxysilane, 4 parts of Desmodur RFE, 56 parts of α-hydrogen-ω-hydroxy-polydimethylsiloxane, 24 parts of 200cps dimethyl silicone oil, and 11 parts of fumed silica. Among them, α-hydrogen-ω-hydroxy-polydimethylsiloxane is purchased from Hubei Chengfeng Chemical Co., Ltd., and its CAS number is 70131-67-8; the same 3-mercaptopropylmethyldimethoxysilane, Desmodur RFE, dimethyl silicone oil, and fumed silica are used as in Example 1.

[0051] The preparation method of the above-mentioned potting glue is as follows: Step 1, put the dried and dehydrated dimethyl silicone oil and the dried and dehydrated α-hydrogen-ω-hydroxy-polydimethylsiloxane into a vacuum kneader, set the temperature to 120° C., stir and disperse evenly, the dispersion time is 30 min, and the vacuum pressure is -95 kPa to obtain material 1; Step 2: Add the dried and dehydrated fumed silica to material 1 in a set ratio, maintain the temperature at 130° C. in a vacuum kneader, stir and disperse evenly, the dispersion time is 50 min, and the vacuum pressure is -95 kPa to obtain material 2. It should be understood that the fumed silica can be added in batches to avoid powder agglomeration.

[0052] Step 3: Cool material 2 to room temperature and transfer it to a vacuum reactor. Add dried and dehydrated 3-mercaptopropylmethyldimethoxysilane according to the set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 120 minutes, and set the vacuum degree to -95 kPa to obtain material 3.

[0053] Step 4: Add the dried and dehydrated Desmodur RFE to material 3 in a set ratio, set the temperature to 25°C, stir and disperse evenly, stir for 40 minutes, and set the vacuum degree to -95 kPa. After filtering through a 60-mesh filter, vacuum pack and obtain a room temperature high-strength potting adhesive.

[0054] Comparative Example 4: A commercially available room temperature potting adhesive.

[0055] Tests of the room temperature high strength potting adhesives of Examples 1 to 5 of the present invention and the potting adhesives of Comparative Examples 1 to 4: Performance tests were conducted in accordance with "HG∕T 5053-2016 Organic Silicone Potting Adhesive Chemical Industry Standard" and "GB 16776-2005 Silicone Structural Sealant for Buildings". The results are shown in Table 1.

[0056] Table 1 Performance test results of room temperature high strength potting adhesives of Examples 1 to 5 and potting adhesives of Comparative Examples 1 to 4

[0057] As can be seen from Table 1, compared with Example 1, the tensile bonding strength of Example 1 is 3.7 MPa, and the tensile bonding strength of Comparative Example 1 is 1.3 MPa. The tensile bonding strength of the potting glue obtained by replacing 3-mercaptopropylmethyldimethoxysilane with N-β-(aminoethyl)-γ-aminopropyltrimethoxysilane is significantly reduced, which shows that the use of mercaptosilane coupling agent effectively improves the adhesion of the system, increases the crosslinking density, and improves the bonding strength of the potting glue. Compared with Example 1, the surface drying time of Example 1 is 41 min, and the surface drying time of Comparative Example 2 is 123 min. The surface drying time of the potting glue obtained by replacing Desmodur RFE with HDI is longer, indicating that Desmodur RFE has a significant effect on improving the surface drying time. Comparative Example 3 Compared with Example 1, the tensile bonding strength and elongation at 23°C of Example 1 are 462%, and the tensile bonding strength and elongation at 23°C of Comparative Example 3 are 306%, and the tensile bonding strength of Comparative Example 3 is 1.5 MPa. The tensile bonding strength and elongation of the potting glue obtained by replacing the dry silane XLM70 with α-hydrogen-ω-hydroxy-polydimethylsiloxane also have a relatively obvious decrease, indicating that the dry silane XLM70 has a good effect on improving the strength of the curing system. The potting glue prepared in Examples 1 to 5 has a surface drying time of 41 to 50 min, a tensile bonding strength (23°C) of 3.2 to 3.7 MPa, a Shore hardness of 42 to 49 HA, and a tensile bonding strength and elongation at 23°C of 411 to 489%. Compared with the potting glue in Comparative Examples 1 to 4, it has a faster surface drying time, better tensile bonding strength and tensile bonding elongation, indicating that the potting glue provided by the present invention has the characteristics of fast curing speed at room temperature and high bonding strength.

[0058] The test results of Examples 1 to 5 and Comparative Examples 1 to 4 show that the room temperature high strength potting adhesive of the present invention has good room temperature curing speed and mechanical strength. That is to say, the various components of the present invention, namely, the mercaptosilane coupling agent, Desmodur RFE, dry silane XLM70, silicone oil, and fumed silica must be used in combination to achieve the overall comprehensive performance of the material. Replacing similar components cannot achieve the excellent effect of the present invention.

[0059] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A room temperature high strength potting adhesive, characterized in that: The invention is mainly prepared from the following components in parts by weight: 1 to 8 parts of mercaptosilane coupling agent, 1 to 5 parts of Desmodur RFE, 40 to 65 parts of dry silane, 15 to 40 parts of silicone oil and 5 to 15 parts of fumed silica.

2. The room temperature high strength potting adhesive according to claim 1, characterized in that: The invention is mainly prepared from the following components in parts by weight: 4-7 parts of mercaptosilane coupling agent, 3-4 parts of Desmodur RFE, 55-60 parts of dry silane, 18-25 parts of silicone oil and 10-13 parts of fumed silica.

3. The room temperature high strength potting adhesive according to claim 1, characterized in that: The mercaptosilane coupling agent is one or more of 3-mercaptopropylmethyldimethoxysilane, 3-mercaptopropyltriethoxysilane and 3-mercaptopropyltrimethoxysilane.

4. The room temperature high strength potting adhesive according to claim 1, characterized in that: The content of the Desmodur RFE isocyanate is 7-8%.

5. The room temperature high strength potting adhesive according to claim 1, characterized in that: The dry silane is vinyl alkoxysilane grafted polyethylene.

6. The room temperature high strength potting adhesive according to claim 1, characterized in that: The silicone oil is one of dimethyl silicone oils with a viscosity of 50 cps, 100 cps or 200 cps at 25° C., or a mixture thereof.

7. The room temperature high strength potting adhesive according to claim 1, characterized in that: The specific surface area of ​​the fumed silica is 360 to 430 m 2 / g.

8. The method for preparing the room temperature high strength potting adhesive according to any one of claims 1 to 7, characterized in that: The steps include: Step 1: Put silicone oil and dry silane into a vacuum kneader, set the temperature to 120-150° C., stir and disperse evenly, the dispersion time is 20-50 min, and the vacuum pressure is -80--95 kPa to obtain material 1; Step 2: Add fumed silica to material 1 in a set ratio, maintain the temperature at 120-150° C. in a vacuum kneader, stir and disperse evenly, the dispersion time is 20-150 min, and the vacuum pressure is -80--95 kPa to obtain material 2; Step 3, cool material 2 to room temperature and transfer it to a vacuum reactor, add mercaptosilane coupling agent according to the set ratio, set the temperature to 20-40°C, stir and disperse evenly, stir for 20-150 minutes, and set the vacuum degree to -80-95 kPa to obtain material 3; Step 4: Add Desmodur RFE to material 3 in a set ratio, set the temperature to 20-40°C, stir and disperse evenly, stir for 20-40 minutes, set the vacuum degree to -80-95 kPa, filter through a 60-mesh filter, and vacuum package to obtain a room temperature high-strength potting adhesive.

9. The method for preparing the room temperature high strength potting adhesive according to claim 8, characterized in that: The fumed silica in step 2 can be added in batches.

10. Use of the room temperature high strength potting adhesive according to any one of claims 1 to 7 or the room temperature high strength potting adhesive prepared by the preparation method according to claims 8 to 9 as a building or road building material in the construction field, road maintenance or road construction.

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