Process for treating dyed and undyed polyester materials with an agent to overcome or inhibit the destructive effects of ultraviolet light

A process for treating dyed or undyed polyester materials for rendering the same resistant to attack by ultraviolet light comprising;

• contacting the surface of the polyester material for a period of from 2 to 30 seconds with a heated bath maintained at a temperature of from 250.degree. to 430.degree.F. to heat the polyester material to a temperature of less than 430.degree.F., said bath containing a non-volatile polyhydric alcohol as a carrier and an ultraviolet light absorber which is soluble in the polyhydric alcohol and compatible with the polyester material in effective concentrations such that effective amounts of the ultraviolet light absorber are incorporated into the polyester material together with polyhydric alcohol to ensure substantially complete penetration of the bath solution, washing the treated polyester material to remove excess bath solution from the surfaces of the polyester material in an aqueous solution at a temperature less than the treatment temperature;
• then subjecting the washed polyester material to heat so as to raise the temperature of the material to between 350.degree. and 430.degree.F. for a period of time of from 3 to 30 seconds to remove the remaining polyhydric alcohol entrapped in the polyester material whereby the ultraviolet absorber remains intimately combined with the heat treated polyester material to render it resistant to ultraviolet light.