Process for recycling polyacetals
AssigneeTicona LLC
InventorsMichael Haubs, Jurgen Lingnau, Klaus Kurz
Life of this patent
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Abstract
A process for recycling polyoxymethylene polymers is disclosed. A polyoxymethylene polymer is at least partially dissolved in an aprotic compound. The resulting solution or suspension (liquid mixture) is then contacted with a catalyst which causes the polyoxymethylene polymer to be converted into a cyclic acetal. The cyclic acetal can be separated, collected and used in other processes. In one embodiment, the cyclic acetal may be used to produce a polyoxymethylene polymer.
Claims18
A process for the conversion of oxymethylene homo- or copolymers to cyclic acetals comprising the steps:
- a) at least partly dissolving an oxymethylene homo- or copolymer in a liquid medium comprising an aprotic compound, the aprotic compound having boiling point of 120° C. or higher, determined at 1 bar;
- and
- b) converting the at least partly dissolved oxymethylene homo- or copolymer in the presence of a catalyst to cyclic acetals.
A process for the conversion of oxymethylene homo- or copolymers to cyclic acetals comprising the steps:
- a) at least partly dissolving an oxymethylene homo- or copolymer in a liquid medium comprising an aprotic compound;
- and
- b) converting the at least partly dissolved oxymethylene homo- or copolymer in the presence of a catalyst to cyclic acetals;
- and
- wherein the cyclic acetals obtained are purified or separated.
A process for the conversion of oxymethylene homo- or copolymers to cyclic acetals comprising the steps:
- a) at least partly dissolving an oxymethylene homo- or copolymer in a liquid medium comprising an aprotic compound, and wherein the polyoxymethylene homo- or copolymer has a number average molecular weight (Mn) of more than 2,000 Dalton;
- and
- b) converting the at least partly dissolved oxymethylene homo- or copolymer in the presence of a catalyst to cyclic acetals.
Dependencies are inferred from the claim text.