A sealing reinforcing glue applied to piercing crimp terminals and a preparation method thereof

Abstract

The application relates to the technical field of new energy circuit boards, and particularly discloses a sealing reinforcing glue applied to a puncture crimping terminal and a preparation method thereof; the sealing reinforcing glue applied to the puncture crimping terminal comprises ferroelectric ceramic powder, a toughening agent and tackifying resin, the ferroelectric ceramic powder is at least one of BaTiO3 and SrTiO3, 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 a catalyst, 0.3-0.5 parts of a chain extender and 5-8 parts of a reinforcing filler; the BaTiO3 and SrTiO3 dielectric constants are used to control the particles, the breakdown voltage threshold of the sealing glue can be improved, the local electric field distribution can be adjusted on a microscopic level, the generation and development of a discharge channel can be inhibited, and the phenomenon that the sealing glue is damaged by a high-voltage electric field environment can be reduced.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of new energy circuit boards, in particular to a sealing reinforcing glue applied to a piercing crimp terminal and a preparation method thereof. BACKGROUND

[0002] Piercing crimp terminals have a wide range of applications in electrical connections, especially in the fields of automobiles, aerospace, new energy circuit boards and industrial equipment. Such terminals directly contact the wires by piercing the insulation layer, ensuring good electrical performance and mechanical stability. However, in the actual application of piercing crimp terminals in new energy circuit boards, due to environmental factors such as temperature changes, humidity and corrosive media, the piercing crimp points are prone to poor sealing and aging, resulting in a decrease in connection reliability and even causing safety accidents.

[0003] In order to improve the sealing and durability of piercing crimp terminals, existing technical means mainly include the use of traditional silicone sealant, hot melt adhesive and epoxy resin-based sealant. These sealing materials usually cover the piercing crimp points through physical filling, forming a protective film to prevent the intrusion of moisture and other harmful substances. However, in high-voltage environments, the dielectric strength of existing sealants is insufficient, which may cause electrical breakdown, unstable adhesion, current leakage or short circuit, and affect the normal operation of the circuit. SUMMARY

[0004] In order to improve the sealing effect of piercing crimp terminals, the application provides a sealing reinforcing glue applied to a piercing crimp terminal and a preparation method thereof.

[0005] In the first aspect, the application provides a sealing reinforcing glue applied to a piercing crimp terminal, which adopts the following technical solution:

[0006] A sealing reinforcing glue applied to a piercing crimp terminal, comprising ferroelectric ceramic powder, toughening agent and tackifying resin, the ferroelectric ceramic powder being at least one of BaTiO3 and SrTiO3, the toughening agent comprising the following raw materials by weight: oligomeric polyol 30-40 parts, isocyanate 40-50 parts, catalyst 0.5-0.8 parts, chain extender 0.3-0.5 parts, and reinforcing filler 5-8 parts.

[0007] By adopting the technical scheme, BaTiO3 and SrTiO3 are used as ferroelectric ceramic powder, and the uniformly dispersed dielectric constant control particles are introduced into the sealing glue system, so that the breakdown voltage threshold of the sealing glue can be effectively improved, the ferroelectric ceramic powder particles can adjust the local electric field distribution at the micro level, and the generation and development of the discharge channel can be inhibited, thereby greatly reducing the risk of being damaged by high-voltage electric field. The ferroelectric ceramic powder is combined with the toughening agent and the tackifying resin, so that the flexibility, strength and impact resistance of the sealing glue can be improved, and the sealing glue can be ensured to withstand certain external force without being easily damaged during use.

[0008] Preferably, the oligomeric polyol is one of a polyether diol and a polyester diol.

[0009] Preferably, the reinforcing filler is at least one of calcium carbonate and halloysite nanotube.

[0010] By adopting the technical scheme, the halloysite nanotube has 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 sealing glue, and plays a reinforcing role in the sealing glue system. The addition of calcium carbonate to the sealing glue can improve the strength of the sealing glue, reduce the shrinkage rate of the sealing glue, and improve the stability of the sealing glue in a high-voltage electric field.

[0011] Preferably, the toughening agent raw material further includes 1-3 parts of a silane coupling agent.

[0012] By adopting the technical scheme, the silane coupling agent can react with the hydroxyl groups on the surfaces of calcium carbonate and halloysite nanotube through the siloxane groups in the molecular structure to form chemical bonds, and the organic groups of the silane coupling agent can form physical or chemical bonds with the polymer matrix, thereby enhancing the interfacial bonding between the inorganic filler and the toughening agent polymer matrix, improving the strength and impact resistance of the sealing glue.

[0013] Meanwhile, the silane coupling agent can end-cap the polyurethane prepolymer generated by the polymerization of isocyanate and oligomeric polyol, accelerate the curing reaction of the polyurethane prepolymer, promote the curing process of the sealing glue, and improve the storage stability of the sealing glue.

[0014] Preferably, the mass ratio of the ferroelectric ceramic powder, the toughening agent and the tackifying resin is (60-70) :(5-10) :2.

[0015] Preferably, the tackifying resin is one of rosin resin, terpene resin and C5 petroleum resin.

[0016] By adopting the technical scheme, the rosin resin, the terpene resin and the C5 petroleum resin can form physical and chemical adsorption with the surface of the base material through the polar groups in the molecular structure, the adhesion between the sealing reinforcing glue and the base material such as the terminal and the wire is enhanced, the sealing glue can be more firmly attached to the base material, a stable sealing layer is formed, and the debonding or peeling caused by factors such as vibration, thermal expansion and cold contraction is reduced.

[0017] In the second aspect, the application provides a preparation method of sealing reinforcing glue applied to a piercing crimp terminal.

[0018] The preparation method of the sealing reinforcing glue applied to the piercing crimp terminal comprises the following specific steps:

[0019] The oligomeric polyol is dehydrated, and then reacts with isocyanate, a catalyst, a chain extender and a reinforcing supplement at 80-90 DEG C to obtain a toughening agent.

[0020] The toughening agent, the tackifying resin and the ferroelectric ceramic powder are mixed and uniformly stirred to prepare the sealing reinforcing glue applied to the piercing crimp terminal.

[0021] By adopting the technical scheme, the ferroelectric ceramic powder is combined with the toughening agent and the tackifying resin, the stability and safety of the sealing glue in a high-voltage electric field are improved, and the service life of the sealing glue is prolonged.

[0022] Preferably, the preparation method comprises the following specific steps:

[0023] The oligomeric polyol is dehydrated, and then reacts with isocyanate, a catalyst, a chain extender and a reinforcing supplement at 80-90 DEG C for 3-5 hours, and then a silane coupling agent is added to obtain a toughening agent.

[0024] The toughening agent, the tackifying resin and the ferroelectric ceramic powder are mixed and uniformly stirred to prepare the sealing reinforcing glue applied to the piercing crimp terminal.

[0025] In summary, the application has the following beneficial effects:

[0026] 1. Since the application introduces BaTiO3 and SrTiO3 as ferroelectric ceramic powder in the sealing glue system, the breakdown voltage threshold of the sealing glue is improved, the generation and development of the discharge channel are inhibited, and the stability and safety of the sealing glue in a high-voltage electric field are improved. The ferroelectric ceramic powder is combined with the toughening agent and the tackifying resin, the flexibility, strength and impact resistance of the sealing glue are improved.

[0027] 2、In the application, the polyurethane prepolymer generated by polymerization of isocyanate and oligomeric polyol is capped with silane coupling agent to accelerate the curing process of the sealant and improve the storage stability of the sealant. Using rosin resin, terpene resin, and C5 petroleum resin as tackifying resin can enhance the adhesion between the sealant and the terminal, wire, and other substrates, and reduce the debonding or peeling of the sealant. DETAILED DESCRIPTION

[0028] The application will be further described in detail below in conjunction with the examples.

[0029] All raw materials in the examples can be obtained by market purchase.

[0030] Examples

[0031] Example 1

[0032] The present example provides a sealant and reinforcing adhesive applied to a piercing crimp terminal, which includes ferroelectric ceramic powder, toughening agent, and tackifying resin, and the mass ratio of the 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 by weight: oligomeric polyol 35 kg, isocyanate 45 kg, catalyst 0.7 kg, chain extender 0.4 kg, and reinforcing filler 7 kg. The oligomeric polyol is polyester diol, which is selected from PCL-2000 polycaprolactone diol purchased from Hunan Polyren New Material Technology Co., Ltd., the isocyanate is toluene diisocyanate, the catalyst is dibutyltin dilaurate, the chain extender is 1,4-butanediol, and the reinforcing filler is calcium carbonate with an average particle size of 30-50 μm.

[0033] The preparation method of the sealant and reinforcing adhesive applied to the piercing crimp terminal includes the following specific steps:

[0034] S1: After the oligomeric polyol is dehydrated, it is reacted with isocyanate, catalyst, and reinforcing supplement at 85°C for 3 h, and then chain extender is added and reacted for 2 h to obtain a toughening agent.

[0035] S2: The toughening agent, tackifying resin, and ferroelectric ceramic powder are mixed and stirred uniformly to prepare the sealant and reinforcing adhesive applied to the piercing crimp terminal, with a viscosity of 25000 mPa.s.

[0036] Example 2

[0037] The difference between Example 2 and Example 1 is that the mass ratio of ferroelectric ceramic powder, toughening agent, and tackifying resin in the raw materials of the sealant and reinforcing adhesive applied to the piercing crimp terminal is 60:10:2.

[0038] Example 3

[0039] Example 3 differs from Example 1 in that the mass ratio of ferroelectric ceramic powder, toughening agent and tackifying resin in the raw material of the sealing and reinforcing glue applied to the piercing crimp terminal is 70:5:2.

[0040] Example 4

[0041] Example 4 differs from Example 1 in that the use amount of oligomeric polyol in the raw material of the toughening agent is 30 kg, the use amount of isocyanate is 40 kg, the use amount of catalyst is 0.5 kg, the use amount of chain extender is 0.3 kg, and the use amount of reinforcing filler is 5 kg.

[0042] Example 5

[0043] Example 5 differs from Example 1 in that the use amount of oligomeric polyol in the raw material of the toughening agent is 40 kg, the use amount of isocyanate is 50 kg, the use amount of catalyst is 0.8 kg, the use amount of chain extender is 0.5 kg, and the use amount of reinforcing filler is 8 kg.

[0044] Example 6

[0045] Example 6 differs from Example 1 in that the reinforcing filler in the raw material of the toughening agent 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.

[0046] Example 7

[0047] Example 7 differs from Example 6 in that the raw material of the toughening agent further includes 2 kg of silane coupling agent, wherein the silane coupling agent is KH-590.

[0048] The preparation method of the sealing and reinforcing glue applied to the piercing crimp terminal includes the following specific steps:

[0049] S1: After the oligomeric polyol is dehydrated, it is reacted with isocyanate, catalyst and reinforcing supplement at 85°C for 3h, then chain extender is added and reacted for 2h, and finally silane coupling agent is added and reacted for 1h to obtain a toughening agent.

[0050] S2: The toughening agent, tackifying resin and ferroelectric ceramic powder are mixed and stirred uniformly to prepare a sealing and reinforcing glue applied to the piercing crimp terminal, and the viscosity is 26000 mPa.s.

[0051] Example 8

[0052] Example 8 differs from Example 7 in that the use amount of silane coupling agent in the raw material of the toughening agent is 1 kg.

[0053] Example 9

[0054] Example 9 differs from Example 7 in that the amount of silane coupling agent used in the toughener raw material is 3 kg.

[0055] Example 10

[0056] Example 10 differs from Example 7 in that the silane coupling agent used in the toughener raw material is KH-792.

[0057] Example 11

[0058] Example 11 differs from Example 7 in that the tackifying resin used in the raw material of the sealing and reinforcing adhesive applied to the piercing crimp terminal is C5 petroleum resin.

[0059] Example 12

[0060] Example 12 differs from Example 7 in that the ferroelectric ceramic powder used in the raw material of the sealing and reinforcing adhesive applied to the piercing crimp terminal is SrTiO3.

[0061] Comparative Example

[0062] Comparative Example 1

[0063] Comparative Example 1 differs from Example 1 in that no toughener is used in the raw material of the sealing and reinforcing adhesive applied to the piercing crimp terminal.

[0064] Comparative Example 2

[0065] Comparative Example 2 differs from Example 1 in that no toughener and no tackifying resin are used in the raw material of the sealing and reinforcing adhesive applied to the piercing crimp terminal.

[0066] Performance detection test

[0067] The sealing and reinforcing adhesive applied to the piercing crimp terminal provided by Examples 1-12 and Comparative Examples 1-2 of the present application is used to fill and seal the piercing crimp point, and the sealing adhesive has a thickness of 5 mm, is cured at 150°C for 5 min, and is subjected to the following performance detection. The specific detection results are shown in Table 1.

[0068] Detection method

[0069] 1. A voltage test of 200 kV is applied to the surface of the sealing adhesive to detect whether the test sample is broken down.

[0070] 2. The tensile strength and elongation at break of the test sample are detected according to the standard of GB / T 528-2009 “Determination of tensile stress-strain properties of vulcanized or thermoplastic rubber”. The tensile strength of the test sample is detected after the sample is placed in an environment of 80±0.5°C and 85±1% humidity for 320 h.

[0071] Table 1: Performance detection result data table

[0072]

[0073]

[0074] From the performance test results, the prepared sealing reinforcing glue has good stability in a high voltage environment, reduces the risk of being damaged and broken down, and combines ferroelectric ceramic powder with toughening agent and tackifying resin, so as to promote the sealing reinforcing glue to have high elongation at break and tensile strength, and to be able to withstand certain external force without being damaged. From Examples 7-9, by adding an appropriate amount of silane coupling agent in the tackifying resin raw material, on the one hand, the interface between the inorganic filler and the toughening agent polymer matrix can be enhanced, and the strength and toughness of the sealing glue can be improved, and on the other hand, the silane coupling agent can end-cap the polyurethane prepolymer generated by the polymerization of isocyanate and oligomeric polyol, and accelerate the curing process of the sealing glue. From the comparison between Example 10 and Example 7, the comprehensive performance of the silane coupling agent used in Example 7 is more optimal.

[0075] From the comparison between Comparative Examples 1-2 and Example 1, 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, the comprehensive performance of the prepared sealing reinforcing glue is significantly decreased, which further indicates that the sealing glue material composed of single ferroelectric ceramic powder and resin has low strength and toughness, and is easily damaged by external force.

[0076] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, and the 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 and reinforcing adhesive for use in puncturing crimped terminals, characterized in that, The product comprises ferroelectric ceramic powder, toughening agent, and tackifying resin. The ferroelectric ceramic powder is at least one of BaTiO3 and SrTiO3. 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. The reinforcing filler is at least one of calcium carbonate and halloysite nanotubes; The toughening agent raw material also includes 1-3 parts of silane coupling agent; The tackifying resin is one of rosin resin, terpene resin, or C5 petroleum resin.

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

3. The sealing and reinforcing adhesive for puncturing crimped 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.

4. A method for preparing a sealing and reinforcing adhesive for use in puncturing crimped terminals as described in any one of claims 1-3, characterized in that, The specific steps include the following: After dehydration, oligomeric polyols are reacted with isocyanates, catalysts, chain extenders, and reinforcing agents at 80-90℃ to obtain toughening agents; Toughening agent, tackifying resin and ferroelectric ceramic powder are mixed and stirred evenly to prepare a sealing and reinforcing adhesive for use in punctured crimp terminals.

5. The method for preparing the sealing and reinforcing adhesive for puncturing crimped terminals according to claim 4, characterized in that, The specific steps include the following: After dehydrating the oligomeric polyol, it is reacted with isocyanate, catalyst, chain extender and reinforcing agent at 80-90℃ for 3-5 hours, and then a silane coupling agent is added to obtain the toughening agent. Toughening agent, tackifying resin and ferroelectric ceramic powder are mixed and stirred evenly to prepare a sealing and reinforcing adhesive for use in punctured crimp terminals.

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