Polyester film comprising a polymeric phosphonate flame retardant
AssigneeDuPont Teijin Films U.S. Limited Partnership
InventorsShane Ashby, Simon Mortlock, William A. MacDonald, Allan Lovatt
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Abstract
A polyester film comprising a polymeric phosphonate flame retardant in an amount of from about 1.0 to about 25.0 wt % by total weight of the film and further comprising at least one metal cation selected from the group consisting of Group I and Group II metal cations.
Claims25
A polyester film comprising a polymeric phosphonate flame retardant in an amount of from about 1 wt % to about 25 wt %, by total weight of the film, and further comprising at least one metal cation, wherein said at least one metal cation comprises sodium cation, wherein said at least one metal cation is present in the form of a salt with a counter-anion, wherein said counter-anion comprises polyacrylate, wherein the polyester is polyethylene terephthalate, wherein the polyester makes up at least 70% by weight of the total weight of a given layer in the polyester film, wherein the amount of said at least one metal cation is greater than 0 ppm and not more than about 150 ppm relative to the amount of polyester, and wherein the phosphonate flame retardant comprises the formula:
- wherein n is an integer from 1 to about 100, or any integer between this range.
A method for imparting flame retardancy to or improving the flame retardancy of a polyester film, the method comprising the step of providing in the film a combination of a polymeric phosphonate flame retardant, in an amount of from about 1.0 wt % to about 25.0 wt % by total weight of the film, and at least one metal cation, wherein said at least one metal cation comprises sodium cation, wherein said at least one metal cation is present in the form of a salt with a counter-anion, wherein said counter-anion comprises polyacrylate, wherein the polyester is polyethylene terephthalate, wherein the polyester makes up at least 70% by weight of the total weight of a given layer in the polyester film, wherein the amount of said at least one metal cation is greater than 0 ppm and not more than about 150 ppm relative to the amount of polyester, and wherein the phosphonate flame retardant comprises the formula:
- wherein n is an integer from 1 to about 100, or any integer between this range.
Dependencies are inferred from the claim text.