# US 12,595,360 B2 · Roofing compositions comprising linear low-density polyethylene > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,595,360 B2 - Document ID: US12595360B2 - Status: Granted - Kind: B2 - Application number: 17/900,965 - Filed: 2022-09-01 - Published: 2023-03-16 - Granted: 2026-04-07 - Earliest claimed: 2021-09-10 - Assignees: Johns Manville - Applicants: Johns Manville - Inventors: Lichih R Peng; Jordan Kortmeyer; ChangQing Shen; Lance Wang; Jawed Asrar - Web page: https://patentgrep.com/patent/US12595360B2 ## CPC - C08L 23/0815: {with aliphatic 1-olefins containing one carbon-to-carbon double bond} - C08L 23/14: Copolymers of propene (C08L23/16 takes precedence) - C08L 2205/03: containing three or more polymers in a blend - C08L 2205/035: containing four or more polymers in a blend - E04D 5/06: by making use of plastics - C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06) - E04D: ROOF COVERINGS; SKY-LIGHTS; GUTTERS; ROOF-WORKING TOOLS (coverings of outer walls by plaster or other porous material E04F13/00) ## Abstract Provided is a polymer blend composition comprising linear low density polyethylene, a polypropylene polymer, generally comprising a random polypropylene copolymer, and a compatibilizer. In one embodiment, there is provided a polymer blend composition comprising 15 to 35 wt % of a polypropylene polymer, 30-60 wt % of a linear low density polyethylene, and a compatibilizer polymer composition comprising 21-50 wt % of the polymer blend. The polymer blend is quite useful in a roofing membrane. ## Claims ### Claim 1 A polymer blend composition comprising: a) 15 to 35 wt % of a thermoplastic polypropylene polymer; b) 30 to 60 wt % of a linear low density polyethylene; and c) 21-50 wt % of a compatibilizer polymer composition. ### Claim 2 (depends on 1) The polymer blend composition of claim 1, wherein the polymer blend composition comprises: 20 to 30 wt % of the propylene polymer a); 35 to 50 wt % of the linear low density polyethylene; and 30 to 40 wt % of the compatibilizer polymer composition c). ### Claim 3 (depends on 1) The polymer blend composition of claim 1, wherein the compatibilizer polymer compositions of c) comprises a polypropylene matrix polymer. ### Claim 4 (depends on 3) The polymer blend composition of claim 3, wherein the compatibilizer polymer composition of c) comprises an elastomeric polypropylene matrix polymer and a polyethylene matrix polymer. ### Claim 5 (depends on 4) The polymer blend composition of claim 4, wherein the wt ratio of polypropylene matrix polymer to polyethylene matrix polymer ranges from 30:70 to 70:30. ### Claim 6 (depends on 1, 3) The polymer blend composition of claim 1 or 3, wherein the compatibilizer polymer composition of c) comprises a styrenic block copolymer. ### Claim 7 (depends on 1) The polymer blend composition of claim 1, wherein the linear low density polyethylene comprises a butene comonomer, a hexene comonomer, or an octene comonomer. ### Claim 8 (depends on 7) The polymer blend composition of claim 7, wherein the linear low density polyethylene comprises a butene comonomer. ### Claim 9 (depends on 1) The polymer blend composition of claim 1, wherein the linear low density polyethylene has s density in the range of 0.915 to 0.920 g/cm3. ### Claim 10 (depends on 1) The polymer blend composition of claim 1, wherein the propylene polymer a) has a density of 0.88 to 0.91 g/cm3 and a melt flow rate of 0.5 to 5 g/10 min. ### Claim 11 (depends on 10) The polymer blend composition of claim 10, wherein the propylene polymer a) exhibits a melt flow rate of 0.6 to 4.0 g/10 min. ### Claim 12 (depends on 1) The polymer blend composition of claim 1, wherein the propylene polymer a) is free of rubber. ### Claim 13 (depends on 1) The polymer blend composition of claim 1, wherein component a) comprises a random polypropylene copolymer containing less than 10 mol % ethylene monomer. ### Claim 14 A membrane composition comprising: a) from about 40 wt % to 70 wt % of a polymer blend composition comprising: (i) 15 to 35 wt % of a thermoplastic polypropylene polymer; (ii) 30 to 60 wt % of a linear low density polyethylene; and (iii) 21-50 wt % of a compatibilizer polymer composition; b) at least one flame retardant; c) at least one ultraviolet stabilizer; and d) at least one pigment. ### Claim 15 (depends on 14) The membrane composition of claim 14, wherein the flame retardant comprises 20 to 45 wt % of the composition. ### Claim 16 (depends on 14) The membrane composition of claim 14, wherein the pigment comprises from 3 to 6 wt % of the composition. ### Claim 17 (depends on 14) The membrane composition of claim 14, wherein the pigment comprises TiO2. ### Claim 18 (depends on 14) The membrane composition of claim 14, wherein the UV stabilizer comprises about 3 to 7 wt % of the composition. ### Claim 19 (depends on 18) The membrane composition of claim 18, wherein the UV stabilizer comprises about 5 wt % of the composition. ### Claim 20 (depends on 14) The membrane composition of claim 14, comprising calcium carbonate. ### Claim 21 (depends on 14) The membrane composition of claim 14, wherein the flame retardant comprises calcium carbonate. ### Claim 22 (depends on 21) The membrane composition of claim 21, wherein calcium carbonate comprises at least 25 wt % of the membrane composition. ### Claim 23 (depends on 22) The membrane composition of claim 22, wherein the amount of calcium carbonate comprises at least about 27 wt % of the membrane composition. ### Claim 24 (depends on 14) The membrane composition of claim 14, wherein the composition exhibits improved heat aging properties compared to a membrane composition comprising an in-reactor blend resin. ### Claim 25 (depends on 14) A roofing membrane comprising the membrane composition of claim 14. ### Claim 26 (depends on 25) A roof comprising the roofing membrane of claim 25. ### Claim 27 (depends on 14) A method of preparing a thermoplastic polyolefin film, the method comprising forming a thermoplastic polyolefin film from the composition of claim 14. ### Claim 28 (depends on 14) The membrane composition of claim 14, wherein the polymer blend composition of a) comprises: 20 to 30 wt % of the propylene polymer (i); 35 to 50 wt % of the linear low density polyethylene (ii); and 30 to 40 wt % of the compatibilizer polymer composition (iii).