초록 ▼

Disclosed is a process for esterifying and/or transesterifying a polymer having a polyethylenic backbone and pendant acid and/or ester moieties comprising contacting a melt of the polymer with a transesterifying compound so that the polymer undergoes esterification and/or transesterification but not

Disclosed is a process for esterifying and/or transesterifying a polymer having a polyethylenic backbone and pendant acid and/or ester moieties comprising contacting a melt of the polymer with a transesterifying compound so that the polymer undergoes esterification and/or transesterification but not alcoholysis. The esterified or transesterified polymer also has pendant ester moieties which differ in kind and/or number from the unreacted polymer. In one embodiment, the process also comprises adding an amount of a transition metal salt that is effective to promote oxygen scavenging. Also in a further embodiment, the process comprises irradiating the transesterified polymer with actinic radiation to reduce the induction period before oxygen scavenging commences. Also disclosed are compositions comprising a component which comprises an ethylenic or polyethylenic backbone and a pendant or terminal moiety comprising a benzylic, allylic, or ether-containing radical. The invention also embodies new polyethylenic oxygen scavenging compositions comprising a transition-metal salt and the above component. Methods of making the compositions, and methods and compositions using the ethylenic or polyethylenic compositions, are disclosed.

대표청구항 ▼

1. A composition, comprising:an oxygen barrier polymer; a compound having a polyethylenic backbone, wherein the compound either (i) has pendant or terminal moieties comprising allylic moieties having at least one alpha hydrogen or (ii) is ethylene/methyl acrylate/benzyl acrylate terpolymer, and, a t

1. A composition, comprising:an oxygen barrier polymer; a compound having a polyethylenic backbone, wherein the compound either (i) has pendant or terminal moieties comprising allylic moieties having at least one alpha hydrogen or (ii) is ethylene/methyl acrylate/benzyl acrylate terpolymer, and, a transition metal salt. 2. A composition, comprising:an oxygen barrier polymer; a compound having a polyethylenic backbone and pendant or terminal moieties which contain a carbon atom that form a resonance-stabilized free radial under oxygen scavenging conditions, wherein either (i) the pendant or terminal moieties comprise allylic moieties having at least one alpha hydrogen or (ii) the compound is ethylene/methyl acrylate/benzyl acrylate terpolymer, and, a transition metal salt. 3. The composition of claim 2, wherein the oxygen barrier polymer is ethylene/vinyl alcohol copolymer (EVOH).4. The composition of claim 2, wherein the oxygen barrier polymer is poly(ethylene terephthalate) (PET).5. The composition of claim 2, wherein the allylic moieties are cyclic, linear, or branched.6. The composition of claim 5, wherein the allylic moieties are cyclic.7. The composition of claim 2, wherein the compound is ethylene/methyl acrylate/benzyl acrylate terpolymer.8. The composition of claim 2, wherein the transition metal salt comprises cobalt.9. The composition of claim 8, wherein the transition metal salt comprises cobalt neodecanoate or cobalt benzoate.10. The composition of claim 2, wherein the oxygen barrier polymer is EVOH, the compound is ethylene/methyl acrylate/benzyl acrylate terpolymer, and the transition metal salt comprises cobalt neodecanoate or cobalt benzoate.