The invention discloses a
halogen-free
epoxy adhesive for a PET protective film or an
insulation layer, which is prepared from the following raw materials in part by
mass:
halogen-free
epoxy resin of 30 to 50,
solvent of 20 to 60, flexibilizer of 20 to 35,
flame retardant of 10 to 30, curing agent of 1 to 5 and
promoter of 0.01 to 0.1. A preparation method of the
halogen-free
epoxy adhesive comprises the following steps of: adding the halogen-free epoxy resin and the
solvent into a container according to a
mass ratio of 100: 50, stirring till the
mixed materials are dissolved completely and recoding the obtained product as a component A; adding the flexibilizer and the
solvent into the container according to a
mass ratio of 100: 100, stirring till the
mixed materials are dissolved completely and recoding the obtained product as a component B; and mixing the component A, the component B, the
flame retardant, the curing agent and the
promoter according to a
mass ratio of (45-60): (40-70): (10-30): (1-5): (0.01-0.1) and uniformly stirring the mixture to obtain the halogen-free
epoxy adhesive. Tests show that the halogen-free
epoxy adhesive has the heat-resistance temperature of 288 DEG C and the
flame-resistance grade of UL94VTM-0 and meets the application requirements of flexible printed circuit (FPC) and flexible flat cable (FFC) terminals on
heat resistance, insulation and
flame resistance.