METHOD OF MAKING POLYCARBONATE MOULDS WITH TWO-LAYER COATING Russian patent published in 2013 - IPC B32B27/30 B32B27/08 C08J7/04 

FIELD: process engineering.

SUBSTANCE: invention relates to production of moulds from polycarbonate with protective coating to be used in construction, aircraft building, instrument making, automotive industry etc using articles of polycarbonates including translucent articles, wear-proof articles, those with high hardness and resistance to ambient effects. Proposed method comprises forming the undercoat on polycarbonate substrate surface. Said undercoat is based on polymethyl methacrylate in the mix of two solvents, i.e. ethyl cellulosolve and chloroform. Besides it includes air drying, finish drying at 120°C to complete removal of solvent to undercoat film thickness of 10-30 mcm. Thereafter substrate with undercoat is heat-treated at 155-175°C and 50-100 MPa for 3-5 seconds and cooled to 70-75 °C at the same pressure. Then, coating of aqueous-alcoholic siloxane composition based on condensation of the mix of two three-functional alkoxysilanes is applied thereon and hardened at 80-85°C.

EFFECT: higher wear resistance and surface hardness.

3 cl, 1 tbl, 10 ex