US 11,976,181 B2 · Hydrogenated nitrile rubber with reduced catalyst impurity

Abstract

The residual hydrogenation catalyst from the hydrogenated nitrile rubber solution is recovered by using two steps such as (1) the catalyst extraction step with an ammonium salt and water (optionally including an oxidation step) to extract catalyst from the HNBR polymer chain to the solvent and then (2) the separation/column recovery step with the column packed with functional ion exchange resins for the separation of ammonia-catalyst complex from hydrogenated nitrile rubber solution and the column recovery for the high catalyst recovery with functional groups of resins. The ammonium salt for the catalyst extraction step is selected from ammonium chloride, ammonium bromide, ammonium iodide, and ammonium acetate. The functional groups in the functional ion exchange resins for packing the column is selected from thiourea, thiouronium, thiol, amine, diamine, triamine, TMT, dithiocarbamate, and carbodithioate.

Claims32

Dependent claims

A process for recovering residual heterogeneous or homogeneous catalyst from hydrogenated nitrile rubber solution comprising the steps of:

(1) a catalyst extraction step with an ammonium salt and water,
(2) an optional oxidation step before and/or during the catalyst extraction step, and
(3) a separation/column recovery step with a column packed with functional ion exchange resin for catalyst recovery of the extracted catalyst;
wherein the ammonium salt in the catalyst extraction step is:
where R1, R2, R3, and R4, are independently selected from hydrogen and alkyl, and X is selected from chloride, bromide, iodide, and acetate.

2 more elements

Dependencies are inferred from the claim text.

Hydrogenated nitrile rubber with reduced catalyst impurity

Life of this patent

Hydrogenated nitrile rubber with reduced catalyst impurity

Life of this patent

Abstract

Claims32