US 12,221,530 B2
Polypropylene copolymer composition having subzero impact resistance
John Kalevi Kaarto, Columbia, MD (US); Jing Zhong, Columbia, MD (US); and Amaia Montoya-Goni, Columbia, MD (US)
Assigned to W. R. Grace & Co.-Conn., Columbia, MD (US)
Appl. No. 17/594,140
Filed by W. R. Grace & Co.-Conn., Columbia, MD (US)
PCT Filed Apr. 3, 2020, PCT No. PCT/US2020/026542
§ 371(c)(1), (2) Date Oct. 4, 2021,
PCT Pub. No. WO2020/206225, PCT Pub. Date Oct. 8, 2020.
Claims priority of provisional application 62/829,932, filed on Apr. 5, 2019.
Prior Publication US 2022/0169843 A1, Jun. 2, 2022
Int. Cl. C08L 23/10 (2006.01)
CPC C08L 23/10 (2013.01) [C08L 2201/10 (2013.01); C08L 2205/025 (2013.01)] 20 Claims
 
1. A polypropylene composition comprising:
a first polymer phase comprising a polypropylene polymer, the polypropylene polymer having a xylene soluble content of less than about 10% by weight and having a melt flow rate of from about 20 g/10 min to about 50 g/10 min;
a second polymer phase combined with the first polymer phase, the second polymer phase comprising a propylene and alpha olefin copolymer; and
wherein the polypropylene composition has a melt flow rate of 3 g/10 min or greater, and wherein the ratio of the melt flow rate of the first polymer phase to the melt flow rate of the polypropylene composition is greater than or equal to 1, the polypropylene composition having a xylene soluble portion and a xylene insoluble portion, the polypropylene composition having a total xylene soluble content of from about 12% to about 25% by weight, the xylene soluble portion containing the alpha olefin in an amount from about 55% to about 70% by weight, the xylene insoluble portion containing the alpha olefin in an amount from about 15% to about 40% by weight, the polypropylene composition having a Gardner impact strength at −20° C. of greater than about 200 inch-lbs.