Selective depolymerisation of polyamide 6 to produce caprolactam from mixtures of caprolactam-containing polymers and polyurethane-containing polymers, in particular polyurethane block copolymers
AssigneeBASF SE
InventorsCaroline Beyer, Florian Richter
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Abstract
A process for obtaining caprolactam from mixtures of caprolactam-containing polymers and polyurethane-containing polymers, in particular polyurethane block copolymers, by depolymerization, wherein the depolymerization of the mixture is performed in the presence of 0.05% to 5% by weight of a base at a temperature of 250° C. to 350° C. and a pressure of 5 to 700 mbar and wherein the caprolactam is obtained in gaseous form.
Claims10
A process for obtaining caprolactam from mixtures of caprolactam-containing polymers and polyurethane-containing polymers by depolymerization, wherein the depolymerization of the mixture is performed in the presence of 0.05% to 5% by weight of a base at a temperature of 250° C. to 350° C. and a pressure of 5 to 700 mbar and wherein the caprolactam is obtained in gaseous form.
A process for obtaining caprolactam from a mixture of caprolactam-containing polymers with polyurethane-containing polymers by depolymerization, comprising the steps of:
- (A) heating the mixture to a temperature of 220° C. to 300° C. to obtain a melt(S),
- (B) adding a base before, during or after step (A),
- (C) charging the melt(S) into at least one depolymerization reactor,
- (D) heating the melt(S) to a temperature of 250° C. to 350° C. to obtain gaseous caprolactam,
- (E) discharging the gaseous caprolactam from the depolymerization reactor to leave behind a residue.
Dependencies are inferred from the claim text.