Compatibilization of polar polymers, such as polyamide and/or EVOH, with nonpolar polymers such as polyethylene and/or polypropylene is commonly achieved by maleic anhydride grafted polymers. Polymer compositions containing functionalized polymers are described in the following references: U.S. Pat. No. 6,075,091, US 20060199914, WO 1994/025526, WO 2007/146875, and WO2011/163176. See also, A. Mendez-Prieto et al., Multilayer Structure Using Reprocessed Coextruded LLDPE/TIE/PA-6 Films, Journal of Polymer Engineering, Vol. 18, No. 3, 1998, 221-234; M. M. Nir et al., Performance of Reprocessed Multilayer LDPE/Nylon-6 Film, Polymer Engineering and Sciences, 1995, Vol. 35, No. 23, 1878-1883.
Traditional maleic anhydride functionalized olefin-based polymers, containing high maleic anhydride content, have been used as compatibilizers between polyolefin and EVOH and/or polyamide, in multicomponent compositions, where the maleic anhydride functionalized polyolefin compatibilizes olefin-based polymers and EVOH and/or polyamide. However, in multicomponent compositions, where the interfacial surface areas are higher, the traditional maleic anhydride functionalized polyolefins can react and form a crosslinked interphase with the polar polymer. Articles such as films, sheets produced from such compositions typically have poor optical and mechanical properties. There is a need for new polymer compositions that will effectively compatibilize polyolefin/polyamide, polyolefin/EVOH, or, polyolefin/polyamide/EVOH systems, without resulting in crosslinked interphases, and which can be used to form films, or sheets with improved optical and mechanical properties. These needs have been met by the following invention.
USPTO Backgrounds
USPTO Backgrounds