Heat-resistant flame-retardant PET composite material, preparation method thereof and application thereof in preparation of patch board

The invention discloses a heat-resistant flame-retardant PET composite material, a preparation method thereof and application thereof in preparation of a patch board. The material is prepared from thefollowing raw materials in parts by weight: 40-70 parts of PET; 10 to 35 parts of a PET derivative; 2-15 parts of a compatilizer; 2-15 parts of a toughening agent; 2-10 parts of a flame retardant; 0.1 to 5 parts of an auxiliary agent; and 0-8 parts of a hydroxyl addition type chain extender. In the composite material, the PET derivative has good toughness and has good compatibility with PET, so that the excellent impact property of the composite material is guaranteed, particularly, after the chain extender is added, the chain extender can reactively increase the capacity of the PET and the PET derivative and improve the binding force between the components, so that the material has more excellent high-temperature resistance and is suitable for patch boards. The method is simple in preparation, easy to implement,