Abstract:
An improved process for recycling unspent diol removed from a polyester manufacturing process wherein the diol is captured, hydrogenated, and recycled so that the final polyester product has improved color over polyesters produced using other recycled diols.
Abstract:
A process that can be used as catalyst in esterification, transesterification or polycondensation is disclosed, which comprises a stable solution comprising (a) titanium in the form of a titanium α-hydroxycarboxylic acid or its salt, (b) a C1-C6 carboxylic acid, and (c) zinc in the form of a water-soluble zinc salt, and (d) water. Also disclosed is an esterification, transesterification or polycondensation process, which comprises contacting, in the presence of the solution process, an organic acid or its ester or its salt with an alcohol, optionally in the presence of a phosphorus compound, an organic or inorganic toning agent such as cobalt acetate, or combinations thereof. The process can also comprise combining aqueous solutions of a titanium α-hydroxycarboxylic acid or its salt and a zinc salt in an alcohol to produce an alcohol solution contacting the alcohol solution with a mixture comprising organic acid or its ester or its salt and a second alcohol, or comprise combining an aqueous solutions of a titanium α-hydroxycarboxylic acid or its salt and aqueous solution of a zinc salt with the mixture.
Abstract:
The present invention relates to a process for producing a polyester comprising: (a) forming a polyester with an intrinsic viscosity of at least about 0.65, wherein said forming of the polyester comprises use of a catalyst; and (b) adding a phosphorous compound to the polyester after the forming of step (a), wherein said phosphorous compound comprises at least one member selected from the group consisting of trialkyl phosphate, trialkyl phosphonoacetate, monoalkyl phosphate, dialkyl phosphate, trialkyl phosphite, triaryl phosphite, tris alkylaryl phosphite, and mixtures thereof. The present invention also includes compositions produced by process of the present invention and articles comprising those compositions.
Abstract:
Disclosed are processes and systems for manufacturing polyethylene terephthalate (PET) and pre-polymer. The processes and systems use a variable pressure drop up-flow-pre-polymerizer configuration. The pressure profile in the UFPP can be selected to beneficially change the relative reaction rates of the polymerization and esterification reactions. This design maximizes the esterification carried out in the UFPP, while still producing a pre-polymer with the optimum carboxyl end groups concentration (e.g., about 30μ equiv./g to 60μ equiv./g) to maximize finisher productivity. This can result in a reduction of the size and cost of the esterifier required for a given plant throughput.
Abstract:
The present invention relates to a process for producing a polyester comprising: (a) forming a polyester in a melt phase having an intrinsic viscosity of about 0.65 or more, provided that said forming is not by solid state polymerization; and (b) adding an anhydride to the polyester during the melt phase. The present invention also includes articles comprising a composition produced by processes of the present invention.