Article comprising poly(hydroxyalkanoic acid)
View Patent ↗Disclosed are oriented films comprising toughened poly(hydroxy-alkanoic acid) resin compositions comprising poly(hydroxyalkanoic acid) and an impact modifier comprising an ethylene copolymer made from monomers (a) ethylene; (b) one or more olefins of the formula CH 2 ═C(R 3 )CO 2 R 4 , where R 3 is hydrogen or an alkyl group with 1-6 carbon atoms, such as methyl, and R 4 is glycidyl; and optionally (c) one or more olefins of the formula CH 2 ═C(R 1 )CO 2 R 2 , where R 1 is hydrogen or an alkyl group with 2-8 carbon atoms and R 2 is an alkyl group with 1-8 carbon atoms, such as methyl, ethyl, or butyl. The ethylene copolymer may further be made from carbon monoxide monomers. The compositions may further comprise one or more ethylene/acrylate and/or ethylene/vinyl ester polymers, ionomers, and cationic grafting agents. Also disclosed are packaging materials and containers comprising the oriented films.
1. A film comprising or prepared from a composition comprising about 60 to about 97 weight % of poly(lactic acid) and about 0.2 to about 40 weight % of an impact modifier wherein
the film is an oriented film; and
the impact modifier comprises an ethylene copolymer that comprises repeat units derived from (a) about 20 to about 95 weight % ethylene, (b) about 0.5 to about 25 weight % of one or more first olefins of the formula CH 2 ═C(R 3 )CO 2 R 4 ; (c) 3 to about 70 weight % of one or more second olefins of the formula CH 2 ═C(R 1 )CO 2 R 2 , and (d) 0 to about 20 weight % carbon monoxide where R 1 is hydrogen or an alkyl group with 1-8 carbon atoms, R 2 is an alkyl group with 1-8 carbon atoms, where R 3 is hydrogen or an alkyl group with 1-6 carbon atoms, R 4 is glycidyl, the weight % of the poly(hydroxyalkanoic acid) and the impact modifier are based on the total weight of the poly(hydroxyalkanoic acid) and the impact modifier, and the weight % of ethylene, CH 2 ═C(R 1 )CO 2 R 2 , or CH 2 ═C(R 3 )CO 2 R 4 is based on the copolymer weight.
2. The film of claim 1 wherein impact modifier is terpolymer of ethylene, glycidyl methacrylate, and butyl acrylate.
3. The film of claim 1 wherein the ethylene copolymer comprises repeat units derived from about 20 to about 35 weight % of the second olefin.
4. The film of claim 1 wherein the ethylene copolymer comprises repeat units derived from up to about 20 weight % of carbon monoxide.
5. The oriented film of claim 3 wherein the ethylene copolymer comprises repeat units derived from up to about 20 weight % of carbon monoxide.
6. The film of claim 1 wherein the impact modifier further comprises about 1 to about 10 weight % of one or more ionomers, based on the total weight of the impact modifier.
7. The film of claim 1 wherein the impact modifier comprises up to about 90 weight % of one or more copolymers of ethylene and an acrylate ester or vinyl acetate, based on the total weight of the impact modifier.
8. The film of claim 6 wherein the impact modifier comprises up to about 90 weight % of one or more copolymers of ethylene and an acrylate ester or vinyl acetate, based on the total weight of the impact modifier.
9. The film of claim 1 further comprising one or more cationic catalysts.
10. An article comprising an oriented film wherein the article is packaging material or container; the container optionally comprises lidding; the film is as recited in claim 1 ; and the lidding comprises or is prepared from the film.
11. The article of claim 10 wherein herein the article is a thermoformed container including tray, cup, or bowl.