Roofing compositions comprising linear low density polyethylene

Patent metadata

Field	Value
Publication number	US-11286380-B2
Application number	US-202016803702-A
Country	US
Kind code	B2
Filing date	Feb 27, 2020
Priority date	Nov 21, 2017
Publication date	Mar 29, 2022
Grant date	Mar 29, 2022

Abstract

Provided is a polymer blend composition comprising linear low density polyethylene, a propylene polymer generally having rubber dispersed therein, and a combination of a propylene copolymer and an ethylene copolymer. In one embodiment, there is provided a polymer blend composition comprising 15 to 75 weight percent of a propylene polymer having from 10-60% crystallinity, 30-50 weight percent of a linear low density polyethylene, and a combination of the propylene copolymer and the ethylene copolymer comprising the remainder of the composition.

First claim

What is claimed is:

1. A polymer blend composition consisting of the following polymers:
a) 20 to 50 wt % of a propylene polymer having rubber dispersed therein and from 10-60% crystallinity based on the weight of the polymer blend;
b) 35 to 45 wt % of a linear low density polyethylene based on the weight of the polymer blend;
c) a propylene/ethylene copolymer having a polypropylene matrix; and
d) an ethylene/propylene copolymer having a polyethylene matrix;
with the combination of the two copolymers c) and d) present in the polymer blend composition in an amount ranging from 8 to 15 wt % based on the weight of the polymer blend.

2. The polymer blend composition of claim 1 , wherein the linear low density polyethylene comprises a butene comonomer.

3. The polymer blend composition of claim 1 , wherein the rubber is an ethylene/propylene rubber.

4. The polymer blend composition of claim 1 , wherein the linear low density polyethylene has a density in the range of 0.915 to 0.920 g/cm 3 .

5. The polymer blend composition of claim 4 , wherein the density of the linear low density polyethylene is in the range of from 0.916 to 0.918 g/cm 3 .

6. The polymer blend composition of claim 1 , wherein the propylene polymer a) has a density of 0.88 to 0.91 g/cm 3 and a melt flow rate of 0.5 to 5 g/10 min.

7. The polymer blend composition of claim 6 , wherein the propylene polymer a) exhibits a melt flow rate of 0.6 to 4.0 g/10 min.

8. The polymer blend composition of claim 1 , wherein the propylene/ethylene copolymer c) exhibits a melt flow rate of 1-25 g/10 min and has a density of 0.860-0.900 g/cm 3 .

9. The polymer blend composition of claim 1 , where the ethylene/propylene copolymer d) exhibits a melt flow rate of 0.5 to 5 g/10 min and has a density of 0.860 to 0.915 g/cm 3 .

10. The polymer blend composition of claim 1 , wherein the amount of propylene/ethylene copolymer c) in the combination of c) and d) ranges from 30 to 70 wt % of the combination.

11. The polymer blend composition of claim 1 , wherein the propylene/ethylene copolymer c) and the ethylene/propylene copolymer d) have been prepared using a metallocene catalyst system.

Assignees

• Johns Manville

Inventors

• Peng Lichih R
• Kortmeyer Jordan
• Wang Lance
• Asrar Jawed

Classifications

• E04D5/06

  by making use of plastics · CPC title

• C08L2205/08

  containing additives to improve the compatibility between two polymers · CPC title

• C08L2207/066

  LDPE (radical process) · CPC title

• C08L2207/02

  Heterophasic composition · CPC title

• C08L2201/02

  Flame or fire retardant/resistant · CPC title