Halogen-free flame-retardant PBT/PC alloy composition and method of preparing the same

Abstract

The invention discloses a halogen-free fire-retardant PTB / PC alloy composition and a preparation method thereof. The formula of the composition comprises the following components in mass percentage: 40 to 50 percent of PBT, 10 to 20 percent of PC, 23 to 33 percent of active magnesium hydrate, 3 to 7 percent of organic phosphate oligomer, 3 to 7 percent of polysiloxane / acrylic ester grafting copolymer, 3 to 7 percent of novolac epoxy, 0.2 to 0.4 percent of antioxidant and 0.4 to 0.8 percent of processing aid. In the formula of the method, all components are dispersed to be mixed and are subject to melting by a double screw extruder, mixing, extrusion, cooling, drying, granulating and packaging. In the invention, the fire-retardant char-forming actions of all added components are combined with the interaction of interfaces of a substrate, which makes the components of the system form an indispensable organic whole, so that the higher fire retardant performance is achieved under the lower consumption of the magnesium hydrate, and the mechanical property, the thermal property and the processability of the system are also good.

Description

technical field [0001] The invention relates to a flame retardant, in particular to a halogen-free flame-retardant PBT / PC alloy composition and a preparation method thereof. Background technique [0002] Polybutylene terephthalate (PBT) is a thermoplastic engineering material with fast crystallization speed, which is easy to realize high-speed molding, has good rigidity and hardness, good creep and solvent resistance, anti-aging performance and can be Processability, low water absorption, but the use of PBT alone has defects such as easy shrinkage and deflection of the part, low heat distortion temperature, and flammability. The polycarbonate (PC) molecular chain contains a large number of benzene rings, which has a large steric hindrance, good rigidity and toughness, high char formation rate, and self-extinguishing. Blending a small amount of PC to modify PBT (that is, to form a PBT / PC alloy) can improve the self-extinguishing property and carbon-forming ability of PBT to ...

AI Technical Summary

Problems solved by technology

The alloy matrix is ​​mainly PC, and its flame retardancy is relatively easy to achieve, and compared with PC, PBT has an obvious price advantage. Therefore, compared with PC / PBT alloy, PBT / PC alloy with PBT as the main body realizes halogen-free resistance In addition, the flame retardant synergist phenylmethyl silicone used in this invention has a small interaction force with the PC and PBT substrates, so it is difficult to form a strong interface bond, and a large amount of MBS and SMAH are required in the system Compatibilizer; moreover, all components of the system are organic polymer materials, which are not beneficial to the shrinkage and deflection of the parts and the improvement of the heat distortion temperature