Method for improving yellowing resistance of PVB (polyvinyl butyral) resin

The invention discloses a method for improving the yellowing resistance of PVB (polyvinyl butyral) resin, which comprises the steps of adding an antioxidant into a reaction raw material butyraldehyde, adding an emulsifying agent into the reaction stock solution, and preparing PVB resin by a conventional method. The preparation method disclosed by the invention breaks the foreign technological monopoly, the control method is relatively easy, high-quality PVB resin for the fields of automobile windshield and construction safety glass is successfully developed, and the problem of yellowing of the PVB resin is solved.