US 11,746,220 B2
High flow rotomolding compositions, processes thereof, and articles therefrom
Eliomar Ricardo Pimenta, São Paulo (BR)
Assigned to Braskem S.A., Camaçari (BR)
Filed by Braskem S.A., Camaçari (BR)
Filed on Jun. 12, 2020, as Appl. No. 16/900,223.
Prior Publication US 2021/0388190 A1, Dec. 16, 2021
Int. Cl. B29C 41/00 (2006.01); B29C 41/04 (2006.01); C08L 23/08 (2006.01); B29L 31/00 (2006.01); B29L 31/30 (2006.01); B29K 23/00 (2006.01); B29L 31/44 (2006.01)
CPC C08L 23/0815 (2013.01) [B29C 41/003 (2013.01); B29C 41/04 (2013.01); B29K 2023/08 (2013.01); B29L 2031/3011 (2013.01); B29L 2031/44 (2013.01); B29L 2031/7172 (2013.01); C08L 2205/025 (2013.01); C08L 2207/062 (2013.01); C08L 2207/066 (2013.01); C08L 2314/02 (2013.01)] 18 Claims
 
1. A rotomolding polymer melt blend composition comprising:
a first polyethylene copolymer having a density, measured according to ASTM D792, of from about 0.935 g/cm3 to about 0.940 g/cm3, a melt flow index, measured according to ASTM D1238 at 190° C./2.16 kg, of from about 3 g/10 min to about 8 g/10 min, and a molecular weight distribution Mw/Mn greater than 4, wherein the first polyethylene copolymer is present at a concentration of from about 70% by weight to about 95% by weight of the polymer melt blend composition; and
a second polyethylene copolymer having a density, measured according to ASTM D792, of from about 0.924 g/cm3 to about 0.934 g/cm3, a melt flow index, measured according to ASTM D1238 at 190° C./2.16 kg, of at least about 17 g/10 min, and a molecular weight distribution Mw/Mn greater than 3.5, wherein the second polyethylene copolymer is present at a concentration of from about 5% by weight to about 30% by weight of the polymer melt blend composition,
wherein the polymer melt blend composition has a density, measured according to ASTM D792, of from about 0.934 g/cm3 to 0.948 g/cm3, a melt flow index, measured according to ASTM D1238 at 190° C./2.16kg, of at least about 6.0 g/10 min, and an ARM impact of at least 55 J measured according to Low Temperature Impact Test Standard from the Association of Rotational Molders International version 4.0 (2003) on a 3.17 mm thickness sample at −40° C.