US 11,965,073 B2
Polyester film comprising a polymeric phosphonate flame retardant
Shane Ashby, Wilton (GB); Simon Mortlock, Dumfries (GB); William A. MacDonald, Wilton (GB); and Allan Lovatt, Wilton (GB)
Assigned to DuPont Teijin Films U.S. Limited Partnership, Wilmington, DE (US)
Filed by DuPont Teijin Films U.S. Limited Partnership, Wilmington, DE (US)
Filed on Mar. 8, 2023, as Appl. No. 18/180,436.
Application 18/180,436 is a continuation of application No. 17/050,830, granted, now 11,634,548, previously published as PCT/GB2019/051165, filed on Apr. 26, 2019.
Claims priority of application No. 1806916 (GB), filed on Apr. 27, 2018.
Prior Publication US 2023/0257538 A1, Aug. 17, 2023
This patent is subject to a terminal disclaimer.
Int. Cl. C08J 5/18 (2006.01); C08J 7/043 (2020.01); C08J 7/052 (2020.01); C08K 5/5357 (2006.01); C08L 67/02 (2006.01)
CPC C08J 5/18 (2013.01) [C08J 7/043 (2020.01); C08J 7/052 (2020.01); C08K 5/5357 (2013.01); C08L 67/02 (2013.01); C08J 2333/04 (2013.01); C08J 2367/02 (2013.01); C08L 2201/02 (2013.01)] 24 Claims
 
1. A polyester film comprising a polymeric phosphonate flame retardant in an amount of from 1 wt % to 25 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, wherein said metal cations are present in the form of a salt with a counter-anion selected from hydroxide, polyacrylate, hydrogen carbonate, carboxylate, chloride, acetate, formate and nitrate, wherein said polyester is polyethylene terephthalate, wherein the amount of said at least one metal cation is greater than 0 ppm and not more than 500 ppm relative to the amount of polyester, and wherein said phosphonate flame retardant is a phosphonate flame retardant of formula I:

OG Complex Work Unit Chemistry
wherein:
Ar is an aromatic group and —O—Ar—O— is derived from a compound having one or more, optionally substituted, aryl rings;
X is a C1-20 alkyl, C2-20 alkene, C2-20 alkene, C5-20 cycloalkyl or C6-20 aryl; and
n is an integer from 1 to 100.