A new type of phosphorus-nitrogen series halogen-free flame-retardant nylon 6 and its preparation method

Abstract

The invention belongs to the technical field of preparation of flame-retardant composite materials through melt blending, and in particular relates to novel nitrogen-phosphorus system halogen-free flame-retardant nylon 6 and a preparation method thereof. The preparation method comprises two steps: 1, mixing diethyl aluminum phosphinate, a macromolecular charring agent, a coupling agent, an antioxidant and nylon 6 resin, and stirring uniformly; and 2, preparing the nitrogen-phosphorus system halogen-free flame-retardant nylon 6 by performing high-temperature melt blending on the mixture obtained in the step 1. According to the novel nitrogen-phosphorus system halogen-free flame-retardant nylon 6 and the preparation method thereof, an organic nitrogen-containing flame retardant is not used, the used macromolecular charring agent has high thermostability which accords with a processing condition of nylon 6, the macromolecular charring agent is added into the nylon 6 resin, and the diethyl aluminum phosphinate is compounded with the macromolecular charring agent, so that the thermostability and flame-retardant effect of the composite material are improved, the usage amount of the diethyl aluminum phosphinate is effectively reduced, and the cost is reduced.

Description

technical field [0001] The invention belongs to the technical field of preparing flame-retardant composite materials by means of melt blending, and specifically relates to a novel phosphorus-nitrogen series halogen-free flame-retardant nylon 6 and a preparation method thereof. Background technique [0002] Nylon 6 is a commonly used engineering plastic. It was developed and applied by DuPont Company of the United States in the 1930s. It has many excellent properties such as high strength, oil resistance, wear resistance, and chemical corrosion resistance. It is widely used in automobile manufacturing, electronics industry, aviation Industry and other fields; but nylon 6 itself is easy to burn as an organic polymer material, and its limiting oxygen index (LOI) is relatively low (generally lower than 24%), and it is easy to drip when burning, which is easy to cause secondary combustion, so Nylon 6 needs to be flame-retardant treated during application. [0003] In order to im...

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Problems solved by technology

[0003] In order to improve the application range of nylon 6, people have developed a variety of highly efficient and environmentally friendly halogen-free flame retardants. Among them, the halogen-free flame retardant aluminum diethylphosphinate developed by Clariant has been widely used, and the US patent (announcement No.: US7294661) introduced a method of applying aluminum diethylphosphinate to flame-retardant nylon materials. However, the production cost of this type of flame retardant is high, and it is difficult to meet the needs of the domestic market.

[0004] Subsequently, people developed a method of compounding aluminum diethylphosphinate and nitrogen-containing flame retardants. The US patent (publication number: US7449508) mentioned the preparation of a flame-retardant nylon material, using aluminum diethylphosphinate and Organic nitrogen-containing synergists are used in combination and added to nylon materials to prepare flame-retardant nylon materials. Not only because of the large amount of aluminum diethylphosphinate and high cost, but also the addition of organic nitrogen-containing flame retardants, so that Its flame retardant efficiency is insufficient, its thermal stability is not good, and it is easy to produce molten droplets when burning, which cannot meet the requirements of industrial use.

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