FOAMABLE POLYOLEFIN COMPOSITIONS AND METHODS THEREOF
Foamed propylene-based reactor made polyolefins, and articles made therefrom, are described. The compositions have a resin that is a reactor made propylene based random copolymer or terpolymer with high comonomer content, combined with a foaming agent. The foaming agent can be at least one physical blowing agent or at least one chemical foaming agent, and may include optional nucleating agents. Reactor made copolymers and terpolymers have a large range of high comonomer content and therefore have physical properties such as increased flexibility, high gloss, lower sealing temperature, and improved compatibility with other polyolefins. These properties translate into a broad scope of potential applications and foamed architecture. This allows the combination of the copolymer or terpolymer, and foaming agents to be fine-tuned for selected foaming application.
1 . A foam composition comprising:
a reactor made polyolefin composition comprising a crystalline random copolymer having:
a) a first propylene-based copolymer or terpolymer selected from the group comprising:
i) a copolymer of propylene and ethylene, wherein the content of the ethylene is between 1-7 wt %;
ii) a copolymer of propylene and at least one C 4 -C 8 alpha-olefin, wherein the content of the alpha-olefin is between 2-14 wt %;
iii) a terpolymer of propylene, ethylene, and at least one C 4 -C 8 alpha-olefin, wherein the content of ethylene is between 0.5-4.5 wt % and the content of the alpha-olefin is between 2-6 wt %, wherein the total content of said ethylene and said at least one alpha-olefins in equal to or lower than 6.5 wt %; and/or
b) a second propylene-based copolymer or terpolymer selected from the group comprising:
i) a copolymer of propylene and at least one C 4 -C 8 alpha-olefin, wherein the content of the alpha-olefin is between 8-30 wt %;
ii) a terpolymer of propylene, ethylene, and at least one C 4 -C 8 alpha-olefin, wherein the content of ethylene is between 1-7 wt % and the content of the alpha-olefin is between 6-8 wt %, wherein the total content of said ethylene and said at least one alpha-olefins in equal to or lower than 6.5 wt %;
wherein said first propylene-based copolymer is present in a 0 to 80 wt % and said second propylene-based is present at a 20 to 100 wt %.
2 . The foam composition of claim Error! Reference source not found., wherein said crystalline random copolymer has a melt flow rate between 2 to 15 g/10 min (ASTM D 1238).
3 . The foam composition of claim Error! Reference source not found., wherein said reactor made polyolefin composition is foamed using at least one physical blowing agent (PBA) or at least one chemical foaming agent (CFA).
4 . The foam composition of claim 3 , wherein said reactor made polyolefin composition is combined with a masterbatch comprising at least one nucleating agent.
5 . The foam composition of claim 4 , wherein said physical blowing agent is selected from a group comprising highly pressurized CO 2 , N 2 , air, propane, isobutane, butane, CFC-derivatives, argon, or combinations thereof.
6 . The foam composition of claim 4 , wherein said chemical foaming agent is in the same masterbatch as at least one nucleating agent or in a different masterbatch as at least one nucleating agent.
7 . The foam composition of claim 6 , wherein the total amount of masterbatch in the foam composition is 5 wt % by weight or less of said reactor made polyolefin composition.
8 . The foam composition of claim 3 , wherein said chemical foaming agent is endothermic or exothermic.
9 . The foam composition of claim 3 , wherein said chemical foaming agent acts as a nucleating agent.
10 . An article comprising a foamed reactor made polyolefin composition according to claim 1 .
11 . The article of claim 10 , said article being a sheet, a strand, a tube, or a container.
12 . A foam composition comprising:
a reactor made polyolefin composition comprising a crystalline propylene/ethylene random copolymer having:
a) from about 4.5 wt % to about 8 wt % of ethylene, and;
b) from about 92 wt % to about 95.5 wt % of propylene
wherein said crystalline propylene/ethylene random copolymer has a melt flow rate between 0.3 and 15 g/10 min (ASTM D 1238).
13 . The foam composition of claim 12 , wherein said reactor made polyolefin composition is foamed using at least one physical blowing agent (PBA) or at least one chemical foaming agent (CFA).
14 . The foam composition of claim 13 , wherein said reactor made polyolefin composition is combined with a masterbatch comprising at least one nucleating agent.
15 . The foam composition of claim 14 , wherein said physical blowing agent is selected from a group comprising highly pressurized CO 2 , N 2 , air, propane, isobutane, butane, CFC-derivatives, argon, or combinations thereof.
16 . The foam composition of claim 14 , wherein said chemical foaming agent is in the same masterbatch as at least one nucleating agent or in a different masterbatch as at least one nucleating agent.
17 . The foam composition of claim 16 , wherein the total amount of masterbatch in the foam composition is 5 wt % by weight or less of said reactor made polyolefin composition.
18 . The foam composition of claim 13 , wherein said chemical foaming agent is endothermic or exothermic.
19 . The foam composition of claim 13 , wherein said chemical foaming agent acts as a nucleating agent.
20 . An article comprising a foamed reactor made polyolefin composition according to claim 12 .