Polyolefin foams for footwear foam applications
A composition that can be used as foam composition is disclosed, which comprises or is produced from an ethylene acrylate copolymer, an acid copolymer or an ionomer of the acid copolymer or both, or combinations thereof, and optionally a soft ethylene polymer. The ethylene acrylate copolymer comprises repeat units derived from ethylene and at least one alkylacrylate. The acid copolymer comprises repeat units derived from ethylene and acrylic acid, methacrylic acid, or combinations thereof. The soft ethylene polymer comprises ethylene and an α-olefin, vinyl acetate, or combinations thereof.
1 . A composition comprising an ethylene acrylate copolymer, an acid copolymer or an ionomer of the acid copolymer or both, and optionally a soft ethylene polymer wherein the ethylene acrylate copolymer comprises repeat units derived from ethylene and at least one alkylacrylate; the acid copolymer comprises repeat units derived from ethylene and (meth)acrylic acid, maleic acid, fumaric acid, maleic anhydride, fumaric anhydride, maleic acid monoester, fumaric acid monoester, or combinations of two or more thereof; and the soft ethylene polymer comprises copolymer of ethylene and an α-olefin, copolymer of ethylene and vinyl acetate, or combinations thereof.
2 . The composition of claim 1 wherein the ethylene acrylate copolymer comprises repeat units derived from ethylene and methyl acrylate, ethyl acrylate, butyl acrylate, or combinations of two or more thereof.
3 . The composition of claim 1 wherein the acid copolymer comprises repeat units derived from ethylene and (meth)acrylic acid, an ionomer of the acid copolymer, or combinations thereof.
4 . The composition of claim 2 wherein the acid copolymer comprises repeat units derived from ethylene and (meth)acrylic acid.
5 . The composition of claim 4 wherein the soft ethylene polymer comprises repeat units derived from ethylene and α-olefin.
6 . The composition of claim 2 wherein the soft ethylene polymer comprises a metallocene catalyst-produced polyethylene having a density less than about 0.89, an ethylene-vinyl acetate copolymer comprising at least about 15 weight % vinyl acetate, or combinations thereof.
7 . The composition of claim 1 further comprising about 0.2 to about 1.5 wt % of a crosslinking agent, about 0.5 to about 10 wt % of a blowing agent(s), about 0.1 to about 10 wt % of an activator for the blowing agent, and optionally 0.1 to 1 wt % of a co-curing agent.
8 . A composition comprising or derived from about 50 to about 95 wt % ethylene acrylate copolymer, about 5 to about 50 wt % acid copolymer or an ionomer or the acid copolymer or combinations thereof, and about 0 to about 40 wt % soft ethylene polymer wherein the ethylene acrylate copolymer comprises repeat units derived from ethylene and methyl acrylate, ethyl acrylate, or combinations thereof; the acid copolymer comprises repeat units derived from ethylene and (meth)acrylic acid, an ionomer of the acid copolymer, or combinations of two or more thereof; and the soft ethylene polymer comprises copolymer of ethylene and an α-olefin, copolymer of ethylene and vinyl acetate, or combinations thereof.
9 . The composition of claim 8 wherein the ethylene acrylate copolymer comprises repeat units derived from ethylene and methyl acrylate; the acid copolymer comprises repeat units derived from ethylene and (meth)acrylic acid; and the soft ethylene polymer comprises a very low density PE, metallocene catalyst-produced polyethylene, an ethylene-vinyl acetate copolymer, or combinations of two or more thereof.
10 . The composition of claim 9 wherein the composition comprises or is derived from about 70 to about 90 wt % of the ethylene acrylate copolymer, about 10 to about 30 wt % of the acid copolymer or an ionomer of the acid copolymer or combinations thereof, and about 0 to about 40 wt % of the soft ethylene polymer.
11 . The composition of claim 8 wherein the ethylene acrylate copolymer comprises repeat units derived from methyl acrylate.
12 . The composition of claim 11 wherein the acid copolymer comprises repeat units derived from ethylene and methacrylic acid, acrylic acid, or combinations thereof.
13 . The composition of claim 12 wherein the acid copolymer comprises repeat units derived from methacrylic acid.
14 . The composition of claim 13 comprising the soft ethylene polymer.
15 . The composition of claim 14 wherein the soft ethylene polymer is a metallocene catalyst-produced polyethylene having a density less than about 0.89, an EVA comprising repeat units derived from at least about 15 weight % vinyl acetate.
16 . The composition of claim 15 wherein the soft ethylene polymer is the metallocene catalyst-produced polyethylene.
17 . The composition of claim 15 wherein the ethylene acrylate copolymer comprises about 15 to about 40 wt % methyl acrylate.
18 . The composition of claim 17 additionally comprising a polymer including a low density polyethylene, a linear low density polyethylene, or combinations thereof.
19 . An article comprises or produced from a composition wherein the article includes foam, a midsole for footwear, insole for footwear, or combinations of two or more thereof and the article is as recited in claim 1 .
20 . The article of claim 19 wherein the article is a midsole for footwear, an insole for footwear, or both.