US 2025/0223418 A1 · VALUE CHAIN RETURN PROCESS FOR THE RECOVERY OF PHOSPHOROUS ESTER-BASED FLAME RETARDANTS FROM POLYURETHANE RIGID FOAMS

Abstract

Polyurethane rigid foams containing at least one phosphorous ester-based flame retardant are returned to the value chain by hydrogenating the polyurethane rigid foam, to obtain a hydrogenation product containing a polyamine and a polyol from the polyurethane rigid foam, and recovering the flame retardant from the hydrogenation product. The hydrogenation is carried out in an organic aprotic solvent, in a hydrogen atmosphere, in the presence of at least one homogeneous transition metal catalyst complex, wherein the transition metal is selected from metals of groups 7, 8, 9 and 10 of the periodic table of elements according to IUPAC, and at a reaction temperature of at least 120° C.

Claims20

Dependent claims

A value chain return process for a polyurethane rigid foam comprising at least one phosphorous ester-based flame retardant, comprising:
hydrogenating the polyurethane rigid foam:
in an organic aprotic solvent,
in a hydrogen atmosphere,
in the presence of at least one homogeneous transition metal catalyst complex, wherein the transition metal is selected from metals of groups 7, 8, 9 and 10 of the periodic table of elements according to IUPAC, and
at a reaction temperature of at least 120° C.,
to obtain a hydrogenation product comprising a polyamine and a polyol from the polyurethane rigid foams;
and
recovering the flame retardant from the hydrogenation product.

6 more elements

11:

The process according to claim 10, wherein the at least one polydentate ligand comprises at least one ligand according to formula (I):
in which
each R′ is independently H or C1-C4-alkyl,
R1 and R2, independently of one another, are C1-C12-alkyl, cycloalkyl or aryl,
which alkyl is unsubstituted or carries 1, 2, 3, 4 or 5 identical or different substituents R7, and
which cycloalkyl and aryl are unsubstituted or carry 1, 2, 3, 4 or 5 identical or different substituents R8,
R3 and R4, independently of one another, are H or C1-C12-alkyl, which is unsubstituted or carries 1, 2, 3, 4 or 5 identical or different substituents selected from heterocycloalkyl, aryl, hetaryl, alkoxy, cycloalkoxy, heterocycloalkoxy, aryloxy, hetaryloxy, hydroxyl, NE1E2 and PR1R2,
R5 is H or C1-C12-alkyl, which is unsubstituted or carries 1, 2, 3, 4 or 5 identical or different substituents R7,
R6 is H or C1-C4-alkyl,
or
R4 and R6 are absent and R3 and R5, together with the nitrogen atom to which R3 is bonded and the carbon atom to which R5 is bonded, form a 6-membered heteroaromatic ring,
which is unsubstituted or carries 1, 2, 3, 4 or 5 identical or different substituents which are selected from C1-C12-alkyl, cycloalkyl, aryl and hetaryl,
which alkyl is unsubstituted or carries 1, 2, 3, 4 or 5 identical or different substituents R7, and
which cycloalkyl, aryl and hetaryl are unsubstituted or carry an alkyl substituent which is unsubstituted or carries a substituent selected from alkoxy, cycloalkoxy, heterocycloalkoxy, aryloxy, hetaryloxy, hydroxyl, NE1E2 and PR1R2,
each R7 is independently cycloalkyl, heterocycloalkyl, aryl, hetaryl, alkoxy, cycloalkoxy, heterocycloalkoxy, aryloxy, hetaryloxy, hydroxyl or NE1E2,
each R8 is independently C1-C4-alkyl, cycloalkyl, heterocycloalkyl, aryl, hetaryl, alkoxy, cycloalkoxy, heterocycloalkoxy, aryloxy, hetaryloxy, hydroxyl or NE1E2, and
E1 and E2, independently of one another and independently of each occurrence, are radicals selected from H, C1-C12-alkyl, cycloalkyl and aryl.

14 more elements

Value chain return process for the recovery of phosphorous ester-based flame retardants from polyurethane rigid foams

Life of this patent

Value chain return process for the recovery of phosphorous ester-based flame retardants from polyurethane rigid foams

Life of this patent

Abstract

Claims20