Halogen-containing flame-retardant nylon material with ultrahigh fluidity and high CTI and preparation method thereof

Abstract

The invention relates to an ultrahigh-fluidity high-CTI halogen-containing flame-retardant nylon material and a preparation method thereof. The ultrahigh-fluidity high-CTI halogen-containing flame-retardant nylon material is prepared from, by weight, 100 parts of PA66, 30-40 parts of PA6, 15-30 parts of polybrominated styrene, 4-5 parts of antimony trioxide, 5-8 parts of nano zirconium hydrogen phosphate, 8-10 parts of cadmium oxide, 8-15 parts of glycerol acetate and 20-30 parts of glass fibers; the preparation method comprises the following steps: weighing the PA66, the PA6, the polybrominated styrene, the antimony trioxide, the zirconium hydrogen phosphate and the cadmium oxide according to the weight ratio, mixing by a high-speed mixer, and adding from a main feeding hole of a double-screw extruder; weighing glass fibers and adding the glass fibers from a fifth section of the double-screw extruder; weighing glycerol acetate, and pumping the glycerol acetate from the seventh section of the double-screw extruder; and finally, extruding and granulating the components by a twin-screw extruder to prepare the halogen-containing flame-retardant nylon material with ultrahigh flowability and high CTI. The halogen-containing flame-retardant nylon material disclosed by the invention has excellent flowing capacity and tracking resistance.

Description

technical field [0001] The invention belongs to the technical field of polymer materials, and relates to an ultra-high-flow, high-CTI halogen-containing flame-retardant nylon material and a preparation method thereof, in particular to an ultra-high-flow, high-CTI halogen-containing flame-retardant nylon material for electric vehicle connectors and its Preparation. Background technique [0002] New energy vehicles have the advantages of energy saving, environmental protection, and low noise. The state strongly supports the development of the new energy vehicle industry, which has developed rapidly. As of the end of 2016, the cumulative sales of new energy vehicles in China was about 622,000. The National Development and Reform Commission issued the "Guidelines for the Development of Electric Vehicle Charging Infrastructure 2015-2020" in 2016, pointing out that by 2020, the number of electric vehicles in the market will reach 5 million units, accounting for 15% of vehicle sale...

AI Technical Summary

Problems solved by technology

However, in the actual application process, the temperature resistance of halogen-free flame retardants is not as good as that of halogen-based flame retardants, and the injection molding process of thin-walled products requires extremely high processing temperatures, so it is not suitable for application under high-temperature molding conditions. Moreover, halogen-free flame retardants are easily precipitated by environmental factors such as temperature and humidity, which reduces the safety and stability of materials. However, the use environment of new energy vehicles is extremely complex and requires extremely high stability and safety of materials. Therefore, the application of halogen-free flame retardant system is greatly limited

However, halogen-containing flame-retardant nylon materials, due to the high-temperature or high-voltage carbonization of halogen and antimony, have generally low CTI values ​​(225-250V), which are difficult to meet the requirements of automotive connectors for CTI values ​​≥ 500V.

For the field of halogen-containing flame retardant with high CTI, the CTI value is usually increased by adding non-halogen flame retardants such as phosphorus and nitrogen, such as patent CN106751808A and patent CN104744931A, which are not suitable for high-temperature processing of thin-walled injection molding and new energy The complex environment of automotive use

For the improvement of high fluidity, more tend to add hyperbranched flow modifier, such as patent CN111040436A, patent CN111073273A and patent CN110903640A, although the application of hyperbranched flow modifier can improve the fluidity of nylon, its fluidity is still insufficient To meet the fluidity requirements of ultra-thin connectors

At the same time, the mechanical properties of materials with improved fluidity are significantly reduced due to the enhanced mobility of molecular segments, which can easily lead to the phenomenon that the connectors are not buckled tightly during the insertion and removal process.

Material fluidity can be characterized by the index of melt flow rate (MFI). The current technology can only reach MFI<40g / 10min (275°C, 5kg). extremely restrictive

Images