Patent ID: 7910657

Claim:
A process comprising: depolymerizing, with 1,4-butane diol, a first polymer comprising a polyethylene terephthalate component selected from the group consisting of polyethylene terephthalate homopolymers, polyethylene terephthalate copolymers, and combinations thereof, in the presence of at least one second polymer selected from the group consisting of polyvinyl chlorides, polyvinylidene chlorides, polyamides, polylactic acid, and combinations thereof, in a reactor at a first temperature and a first pressure that is at least atmospheric pressure, for a time and under conditions effective to produce a molten mixture comprising a first component selected from the group consisting of oligomers containing ethylene terephthalate groups, oligomers containing ethylene isophthalate groups, oligomers containing diethylene terephthalate groups, oligomers containing diethylene isophthalate groups, oligomers containing butylene terephthalate groups, oligomers containing butylene isophthalate groups, covalently bonded oligomeric moieties containing at least two of the foregoing groups, 1,4-butane diol, ethylene glycol, and combinations thereof; and a second component selected from the group consisting of (i) the at least one second polymer selected from the group consisting of polyvinyl chlorides, polyvinylidene chlorides, polyamides, polylactic acid, and combinations thereof; (ii) at least one residue derived from the at least one second polymer selected from the group consisting of polyvinyl chlorides, polyvinylidene chlorides, polyamides, polylactic acid, and combinations thereof; and (iii) combinations thereof; and polymerizing the molten mixture at a second temperature that is higher than the first temperature, a second pressure that is lower than the first pressure and that is subatmospheric pressure, with agitation under an inert atmosphere, for a time and under conditions sufficient to form a modified polybutylene terephthalate copolymer having a melting temperature of more than 200° C. and an intrinsic viscosity ranging from 0.5 to 1.4 dL/g, comprising (a) at least one polyethylene terephthalate component residue, and (b) a member selected from the group consisting of (i) the at least one second polymer selected from the group consisting of polyvinyl chlorides, polyvinylidene chlorides, polyamides, polylactic acid, and combinations thereof; (ii) the at least one residue derived from the second polymer; and (iii) combinations thereof.