Sealing reinforcing adhesive applied to piercing and crimping terminal and preparation method of sealing reinforcing adhesive

Abstract

The invention relates to the technical field of new energy circuit boards, and particularly discloses a sealing reinforcing adhesive applied to a piercing crimping terminal and a preparation method thereof. The sealing reinforcing adhesive applied to the piercing and crimping terminal comprises ferroelectric ceramic powder, a toughening agent and tackifying resin, the ferroelectric ceramic powder is at least one of BaTiO3 and SrTiO3, and the toughening agent comprises the following raw materials in parts by weight: 30-40 parts of oligomeric polyol, 40-50 parts of isocyanate, 0.5-0.8 part of a catalyst, 0.3-0.5 part of a chain extender and 5-8 parts of a reinforcing filler; the BaTiO3 and SrTiO3 dielectric constant regulation and control particles are used, so that the breakdown voltage threshold of the sealant can be improved, local electric field distribution can be regulated on the microscopic level, the generation and development of a discharge channel can be inhibited, and the phenomenon that the sealant is damaged by a high-voltage electric field environment can be reduced.

Description

Technical Field

[0001] The present application relates to the technical field of new energy circuit boards, and in particular to a sealing reinforcing adhesive used for piercing crimping terminals and a preparation method thereof. Background Art

[0002] Piercing and crimping terminals are widely used in electrical connections, especially in the fields of automobiles, aerospace, new energy circuit boards, and industrial equipment. This type of terminal directly contacts the wire by piercing the insulation layer, ensuring good electrical performance and mechanical stability. However, in the actual application of piercing and crimping terminals in new energy circuit boards, due to environmental factors such as temperature changes, humidity, and corrosive media, the piercing and crimping points are prone to problems such as poor sealing and aging, resulting in reduced connection reliability and even safety accidents.

[0003] In order to improve the sealing and durability of puncture crimp terminals, existing technical means mainly include the use of traditional silicone sealants, hot melt adhesives, and epoxy resin-based sealants. These sealing materials are usually covered on the puncture crimping points by physical filling to form a protective film to prevent the intrusion of moisture and other harmful substances. However, in places with high voltage electricity, the dielectric strength of existing sealants is insufficient, electrical breakdown may occur, adhesion is unstable, current leakage or short circuit may occur, and the normal operation of the circuit may be affected. Summary of the invention

[0004] In order to improve the sealing effect of the puncture crimping segment, the present application provides a sealing reinforcement adhesive applied to the puncture crimping terminal and a preparation method thereof.

[0005] In a first aspect, the present application provides a sealing reinforcement adhesive for piercing crimped terminals, which adopts the following technical solution: A sealing reinforcing adhesive for puncturing crimped terminals comprises ferroelectric ceramic powder, a toughening agent and a tackifying resin, wherein the ferroelectric ceramic powder is at least one of BaTiO3 and SrTiO3, and the toughening agent comprises the following raw materials in parts by weight: 30-40 parts of oligomeric polyol, 40-50 parts of isocyanate, 0.5-0.8 parts of catalyst, 0.3-0.5 parts of chain extender and 5-8 parts of reinforcing filler.

[0006] By adopting the above technical solution, BaTiO3 and SrTiO3 are used as ferroelectric ceramic powders, and uniformly dispersed dielectric constant control particles are introduced into the sealant system, which can effectively improve the breakdown voltage threshold of the sealant. Ferroelectric ceramic powder particles can adjust the local electric field distribution at the microscopic level, inhibit the generation and development of discharge channels, and thus greatly reduce the risk of being damaged by high-voltage electric fields. Combining ferroelectric ceramic powder with toughening agents and tackifying resins can improve the flexibility, strength and impact resistance of the sealant, and ensure that the sealant can withstand certain external forces during use without being easily damaged.

[0007] Preferably, the oligomeric polyol is one of polyether diol and polyester diol.

[0008] Preferably, the reinforcing filler is at least one of calcium carbonate and halloysite nanotubes.

[0009] By adopting the above technical solution, the halloysite nanotubes have a tubular structure and a polar surface, can be well dispersed in the toughening agent system, can improve the rigidity and impact toughness of the sealant, and play a reinforcing role in the sealant system. Adding calcium carbonate to the sealant can improve the strength of the sealant, reduce the shrinkage of the sealant, and improve the stability of the sealant in a high-voltage electric field.

[0010] Preferably, the toughening agent raw material also includes 1-3 parts of a silane coupling agent.

[0011] By adopting the above technical scheme, the silane coupling agent can react with the hydroxyl groups on the surface of calcium carbonate and halloysite nanotubes through the siloxane groups in the molecular structure to form chemical bonds. At the same time, the organic groups of the silane coupling agent form physical or chemical bonds with the polymer matrix, thereby enhancing the interface bonding between the inorganic filler and the toughening agent polymer matrix, and improving the strength and impact resistance of the sealant.

[0012] At the same time, the silane coupling agent can cap the polyurethane prepolymer generated by the polymerization of isocyanate and oligomeric polyols, accelerate the curing reaction of the polyurethane prepolymer, promote the curing process of the sealant, and improve the storage stability of the sealant.

[0013] Preferably, the mass ratio of the ferroelectric ceramic powder, the toughening agent and the tackifying resin is (60-70):(5-10):2.

[0014] Preferably, the tackifying resin is one of rosin resin, terpene resin and C5 petroleum resin.

[0015] By adopting the above technical scheme, rosin resin, terpene resin and C5 petroleum resin can form physical and chemical adsorption with the surface of the substrate through the polar groups in the molecular structure, thereby enhancing the adhesion between the sealing reinforcement adhesive and substrates such as terminals and wires, enabling the sealant to adhere more firmly to the substrate, forming a stable sealing layer, and reducing debonding or peeling caused by factors such as vibration, thermal expansion and contraction.

[0016] In a second aspect, the present application provides a method for preparing a sealing reinforcing adhesive for piercing crimped terminals, using the following technical solution: A method for preparing a sealing reinforcing adhesive for puncturing a crimped terminal comprises the following specific steps: After dehydrating the oligomeric polyol, react with isocyanate, catalyst, chain extender and reinforcing supplement at 80-90°C to obtain a toughening agent; The toughening agent, the tackifying resin and the ferroelectric ceramic powder are mixed and stirred evenly to prepare a sealing reinforcing adhesive used for puncturing and crimping terminals.

[0017] By adopting the above technical solution and combining ferroelectric ceramic powder with toughening agent and tackifying resin, the stability and safety of the sealant in a high voltage electric field can be improved, and the service life of the sealant can be extended.

[0018] Preferably, the method comprises the following specific steps: After dehydrating the oligomeric polyol, react with isocyanate, catalyst, chain extender and reinforcing agent at 80-90°C for 3-5h, and then add silane coupling agent to obtain a toughening agent; The toughening agent, the tackifying resin and the ferroelectric ceramic powder are mixed and stirred evenly to prepare a sealing reinforcing adhesive used for puncturing and crimping terminals.

[0019] In summary, this application has the following beneficial effects: 1. Since the present application introduces BaTiO3 and SrTiO3 as ferroelectric ceramic powders in the sealant system, the breakdown voltage threshold of the sealant is increased, the generation and development of the discharge channel is suppressed, and the stability and safety of the sealant in the high voltage field are improved. Combining the ferroelectric ceramic powder with a toughening agent and a tackifying resin can improve the flexibility, strength and impact resistance of the sealant.

[0020] 2. In this application, the polyurethane prepolymer generated by polymerization of isocyanate and oligomeric polyol is terminated with a silane coupling agent to accelerate the curing process of the sealant and improve the storage stability of the sealant. Rosin resin, terpene resin, and C5 petroleum resin are used as tackifying resins to enhance the adhesion between the sealant and substrates such as terminals and wires, and reduce the debonding or peeling of the sealant. DETAILED DESCRIPTION

[0021] The present application is further described in detail below in conjunction with embodiments.

[0022] All raw materials in the examples are commercially available. Example

[0023] Example 1 The present embodiment provides a sealing reinforcing adhesive for puncturing crimping terminals, including ferroelectric ceramic powder, toughening agent and tackifying resin, the mass ratio of ferroelectric ceramic powder, toughening agent and tackifying resin is 65:8:2, the ferroelectric ceramic powder is BaTiO3, the tackifying resin is rosin resin, and the rosin resin is DMER-95; the toughening agent includes the following raw materials in parts by weight: 35kg of oligomeric polyol, 45kg of isocyanate, 0.7kg of catalyst, 0.4kg of chain extender, and 7kg of reinforcing filler. Among them, the oligomeric polyol is polyester diol, and the polyester diol is purchased from Hunan Juren Chemical New Materials Technology Co., Ltd. PCL-2000 polycaprolactone diol, the isocyanate is toluene diisocyanate, the catalyst is dibutyltin dilaurate, the chain extender is 1,4-butanediol, the reinforcing filler is calcium carbonate, and the average particle size of the reinforcing filler is 30-50μm.

[0024] The preparation method of the sealing reinforcing adhesive used for piercing crimping terminals comprises the following specific steps: S1: After dehydrating the oligomeric polyol, react with isocyanate, catalyst and reinforcing agent at 85°C for 3h, then add chain extender and react for 2h to obtain toughening agent.

[0025] S2: The toughening agent, the tackifying resin and the ferroelectric ceramic powder are mixed and stirred evenly to form a sealing reinforcing adhesive for puncturing and crimping terminals, with a viscosity of 25000 mPa.s.

[0026] Example 2 The difference between Example 2 and Example 1 is that the mass ratio of the ferroelectric ceramic powder, the toughening agent and the tackifying resin in the raw material of the sealing reinforcement glue used for the puncture crimping terminal is 60:10:2.

[0027] Example 3 The difference between Example 3 and Example 1 is that the mass ratio of the ferroelectric ceramic powder, the toughening agent and the tackifying resin in the raw material of the sealing reinforcement glue used for the puncture crimping terminal is 70:5:2.

[0028] Example 4 The difference between Example 4 and Example 1 is that the usage of the oligomeric polyol in the toughening agent raw material is 30 kg, the usage of the isocyanate is 40 kg, the usage of the catalyst is 0.5 kg, the usage of the chain extender is 0.3 kg, and the usage of the reinforcing filler is 5 kg.

[0029] Example 5 The difference between Example 5 and Example 1 is that the usage of the oligomeric polyol in the toughening agent raw material is 40 kg, the usage of the isocyanate is 50 kg, the usage of the catalyst is 0.8 kg, the usage of the chain extender is 0.5 kg, and the usage of the reinforcing filler is 8 kg.

[0030] Example 6 The difference between Example 6 and Example 1 is that the reinforcing filler in the toughening agent raw material is a mixture of calcium carbonate and halloysite nanotubes, and the mass ratio of calcium carbonate to halloysite nanotubes is 1: 1. The average diameter of the halloysite nanotubes is 50 nm, and the average tube length is 400 nm.

[0031] Example 7 The difference between Example 7 and Example 6 is that the toughening agent raw material further includes 2 kg of silane coupling agent, wherein the silane coupling agent is KH-590.

[0032] The preparation method of the sealing reinforcing adhesive used for piercing crimping terminals comprises the following specific steps: S1: After dehydrating the oligomeric polyol, react with isocyanate, catalyst and reinforcing agent at 85°C for 3h, then add chain extender and react for 2h, and finally add silane coupling agent and react for 1h to obtain toughening agent.

[0033] S2: The toughening agent, the tackifying resin and the ferroelectric ceramic powder are mixed and stirred evenly to form a sealing reinforcing adhesive for puncturing and crimping terminals, with a viscosity of 26000 mPa.s.

[0034] Example 8 The difference between Example 8 and Example 7 is that the amount of silane coupling agent used in the toughening agent raw material is 1 kg.

[0035] Example 9 The difference between Example 9 and Example 7 is that the amount of silane coupling agent used in the toughening agent raw material is 3 kg.

[0036] Example 10 The difference between Example 10 and Example 7 is that the silane coupling agent in the toughening agent raw material is KH-792.

[0037] Embodiment 11 The difference between Example 11 and Example 7 is that the tackifying resin in the raw material of the sealing reinforcing adhesive used for the puncture crimping terminal is C5 petroleum resin.

[0038] Example 12 The difference between Example 12 and Example 7 is that the ferroelectric ceramic powder in the raw material of the sealing reinforcement glue used for piercing and crimping terminals is SrTiO3.

[0039] Comparative Example Comparative Example 1 The difference between Comparative Example 1 and Example 1 is that no toughening agent is used in the raw material of the sealing reinforcing glue used for piercing and crimping terminals.

[0040] Comparative Example 2 The difference between Comparative Example 2 and Example 1 is that no toughening agent and tackifying resin are used in the raw material of the sealing reinforcing adhesive used for the puncture crimping terminal.

[0041] Performance testing According to the sealing reinforcement glue applied to the puncture crimping terminal provided in Examples 1-12 and Comparative Examples 1-2 of the present application, the puncture crimping point is filled and sealed for protection. The thickness of the sealant is 5 mm and it is cured at 150°C for 5 minutes. The following performance tests are performed. The specific test results are shown in Table 1.

[0042] Detection Methods 1. Apply a 200kV voltage test on the surface of the sealant to detect whether the sample is broken down.

[0043] 2. Refer to GB / T528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber" to test the tensile strength and elongation at break of the sample. Place the sample in an environment of 80±0.5℃ and 85±1% humidity for 320 hours, and then test the tensile strength of the sample.

[0044] Table 1: Performance test results data table It can be seen from the performance test results that the present application can have good stability in a high voltage electrical environment, reduce the risk of being destroyed and punctured, and simultaneously combine ferroelectric ceramic powder with toughening agent and tackifying resin, so that the sealing reinforcement glue has a higher elongation at break and tensile strength, and can withstand a certain external force without being destroyed. It can be seen from Examples 7-9 that by adding an appropriate amount of silane coupling agent to the tackifying resin raw material, on the one hand, the interface bonding between the inorganic filler and the toughening agent polymer matrix can be enhanced, and the strength and toughness of the sealant can be improved, and on the other hand, the polyurethane prepolymer generated by the polymerization of isocyanate and oligomeric polyols can be capped, and the curing process of the sealant can be accelerated. It can be seen from Example 10 compared with Example 7 that the comprehensive performance of the silane coupling agent used in Example 7 is better.

[0045] By comparing Comparative Examples 1-2 with Example 1, it can be seen that Comparative Example 1 does not use a toughening agent, and Comparative Example 2 does not use a toughening agent and a tackifying resin. From the performance test results, it can be seen that the comprehensive performance of the prepared sealing reinforcement adhesive is significantly reduced, which further illustrates that the sealant material composed of a single ferroelectric ceramic powder and resin has low strength and toughness and is easily damaged by external forces.

[0046] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed, but such modifications are protected by the patent law as long as they are within the scope of the claims of the present application.

Claims

1. A sealing reinforcing adhesive used for puncturing crimped terminals, characterized in that: The invention comprises ferroelectric ceramic powder, toughening agent and tackifying resin, wherein the ferroelectric ceramic powder is at least one of BaTiO3 and SrTiO3, and the toughening agent comprises the following raw materials in parts by weight: 30-40 parts of oligomeric polyol, 40-50 parts of isocyanate, 0.5-0.8 parts of catalyst, 0.3-0.5 parts of chain extender and 5-8 parts of reinforcing filler.

2. The sealing reinforcing adhesive for piercing and crimping terminals according to claim 1, characterized in that: The oligomeric polyol is one of polyether diol and polyester diol.

3. The sealing reinforcing adhesive for piercing and crimping terminals according to claim 1, characterized in that: The reinforcing filler is at least one of calcium carbonate and halloysite nanotubes.

4. The sealing reinforcing adhesive for piercing and crimping terminals according to claim 3, characterized in that: The toughening agent raw material also includes 1-3 parts of silane coupling agent.

5. The sealing reinforcing adhesive for puncturing and crimping terminals according to claim 1, characterized in that: The mass ratio of the ferroelectric ceramic powder, toughening agent and tackifying resin is (60-70):(5-10):

2.

6. The sealing reinforcing adhesive for piercing and crimping terminals according to claim 5, characterized in that: The tackifying resin is one of rosin resin, terpene resin and C5 petroleum resin.

7. A method for preparing a sealing reinforcing adhesive for piercing crimping terminals according to any one of claims 1 to 6, characterized in that: The specific steps include: After dehydrating the oligomeric polyol, react with isocyanate, catalyst, chain extender and reinforcing supplement at 80-90°C to obtain a toughening agent; The toughening agent, the tackifying resin and the ferroelectric ceramic powder are mixed and stirred evenly to prepare a sealing reinforcing adhesive used for puncturing and crimping terminals.

8. The method for preparing the sealing reinforcing adhesive for puncturing and crimping terminals according to claim 7, characterized in that: The specific steps include: After dehydrating the oligomeric polyol, react with isocyanate, catalyst, chain extender and reinforcing agent at 80-90°C for 3-5h, and then add silane coupling agent to obtain a toughening agent; The toughening agent, the tackifying resin and the ferroelectric ceramic powder are mixed and stirred evenly to prepare a sealing reinforcing adhesive used for puncturing and crimping terminals.

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