This invention relates to a method for preparing halogen-free flame retardant for acrylic acid pressure-sensitive adhesive tape. The halogen-free flame retardant comprises: organic halogen-free flame phosphate 0-50 wt.%, inorganic matters 20-90 wt.%, and nitrogen-containing compounds 5-50 wt.%. The method comprises: (1) mixing the components with organic solvent at a weight ratio of 1: 1 to obtain a slurry, and milling in a ball mill for 2-4 h; (2) sieving by 120 mesh sieve, pouring the liquid into acrylic acid pressure-sensitive adhesive, and stirring evenly to obtain acrylic acid pressure-sensitive adhesive containing the halogen-free flame retardant; (3) coating onto a matrix material to obtain acrylic acid pressure-sensitive adhesive tape. The acrylic acid pressure-sensitive adhesive tape added with the halogen-free flame retardant has good flame retardancy without damage to its adhesiveness and electric properties. |