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US 11,629,247 B2Granted
Polymer blends with improved processability for TPO roofing membranes and methods for making same
AssigneeExxonMobil Chemicals Patents Inc.
InventorsChen Qian, Dayana M. Cevallos, Felix M. Zacarias
Life of this patent
Estimating the term…
Abstract
A polymer blend includes 35 to 50 wt % of at least one propylene-based elastomer, 25 to 50 wt % of at least one impact copolymer; and 15 to 25 wt % of at least one low density polyethylene component. The propylene-based elastomer has a heat of fusion less than about 80 J/g, greater than 50 wt % propylene and from about 3 wt % to about 25 wt % units derived from one or more C2 or C4-C12 α-olefins, based on a total weight of the propylene-based elastomer. The low density polyethylene has a density of about 0.90 g/cm3 to about 0.94 g/cm3. The polymer blend is useful for making a roofing membrane.
Claims20
A roofing membrane, comprising:
- 60 wt % to 70 wt % of a polymer blend comprising:
- 35 wt % to 50 wt % of at least one propylene-based elastomer, based on the total weight of the polymer blend, the at least one propylene-based elastomer having a heat of fusion less than about 80 J/g as determined by DSC, a density of 0.850 g/cm3 to 0.920 g/cm3 per ASTM D-1505, crystallinity of 2% to 65% of isotactic polypropylene and a melting point (Tm) of 100° C. or less, wherein the propylene-based elastomer comprises greater than 50 wt % propylene and from about 3 wt % to about 25 wt % units derived from one or more C2 or C4-C12 α-olefins, based on a total weight of the propylene-based elastomer;
- 25 wt % to 50 wt % of at least one impact copolymer, based on the total weight of the polymer blend, the at least one impact copolymer comprising a propylene homopolymer blended with a propylene copolymer;
- and
- 15 wt % to 25 wt % of at least one low density polyethylene component, based on the total weight of the polymer blend, the at least one low density polyethylene component having a density of 0.920 g/cm3 to 0.940 g/cm3, a melt index @190° C./2.16 kg of about 0.20 g/10 min to about 3.0 g/10 min, as measured according to ASTM D1238, wherein the combined weight of the at least one propylene-based elastomer and the at least one low density polyethylene component is 50 wt % to 65 wt %;
- and
- 30 wt % to 40 wt % of masterbatch comprising an anti-ultraviolet agent, color pigment and fire retardant.
4 more elements
A roofing membrane, comprising:
- a polymer blend consisting essentially of:
- 35 wt % to 50 wt % of at least one propylene-based elastomer, based on the total weight of the polymer blend, the at least one propylene-based elastomer having a heat of fusion less than about 80 J/g as determined by DSC, a density of 0.850 g/cm3 to 0.920 g/cm3 per ASTM D-1505, crystallinity of 2% to 65% of isotactic polypropylene and a melting point (Tm) of 100° C. or less, wherein the propylene-based elastomer comprises greater than 50 wt % propylene and from about 3 wt % to about 25 wt % units derived from one or more C2 or C4-C12 α-olefins, based on a total weight of the propylene-based elastomer;
- 25 wt % to 50 wt % of at least one impact copolymer, based on the total weight of the polymer blend, the at least one impact copolymer comprising a propylene homopolymer blended with a propylene copolymer;
- and
- about 15 wt % of at least one low density polyethylene component, based on the total weight of the polymer blend, the at least one low density polyethylene component having a density of 0.920 g/cm3 to 0.940 g/cm3, a melt index @190° C./2.16 kg of about 0.20 g/10 min to about 3.0 g/10 min, as measured according to ASTM D1238, wherein the combined weight of the at least one propylene-based elastomer and the at least one low density polyethylene component is 50 wt % to 65 wt %.
2 more elements
A roofing membrane, comprising:
- a polymer blend consisting essentially of:
- 35 wt % to 50 wt % of at least one propylene-based elastomer, based on the total weight of the polymer blend, the at least one propylene-based elastomer having a heat of fusion less than about 80 J/g as determined by DSC, a density of 0.850 g/cm3 to 0.920 g/cm3 per ASTM D-1505, crystallinity of 2% to 65% of isotactic polypropylene and a melting point (Tm) of 100° C. or less, wherein the propylene-based elastomer comprises greater than 50 wt % propylene and from about 3 wt % to about 25 wt % units derived from one or more C2 or C4-C12 α-olefins, based on a total weight of the propylene-based elastomer;
- 25 wt % to 50 wt % of at least one impact copolymer, based on the total weight of the polymer blend, the at least one impact copolymer comprising a propylene homopolymer blended with a propylene copolymer;
- and
- about 25 wt % of at least one low density polyethylene component, based on the total weight of the polymer blend, the at least one low density polyethylene component having a density of 0.920 g/cm3 to 0.940 g/cm3, a melt index @190° C./2.16 kg of about 0.20 g/10 min to about 0.3 g/10 min, as measured according to ASTM D1238, wherein the combined weight of the at least one propylene-based elastomer and the at least one low density polyethylene component is 50 wt % to 65 wt %.
2 more elements
Dependencies are inferred from the claim text.