# US 4,396,761 A · Method for removing hydrogenation catalyst residues from hydrogenated conjugated diene polymers

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- Number: US 4,396,761 A
- Document ID: US4396761A
- Status: Granted
- Kind: A
- Application number: 06/294,969
- Filed: 1981-08-21
- Granted: 1983-08-02
- Earliest claimed: 1981-08-21
- Assignees: Shell Oil Company
- Inventors: Carl L. Willis; Lynn H. Slaugh
- Web page: https://patentgrep.com/patent/US4396761A

## CPC

- C08C 2/04: Removal of catalyst residues
- C08F 6/02: Neutralisation of the polymerisation mass, e.g. killing the catalyst (short-stopping C08F2/42 ){also removal of catalyst residues}
- C08C: TREATMENT OR CHEMICAL MODIFICATION OF RUBBERS
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS

## Abstract

A process is disclosed for removing hydrogenation catalyst residues from hydrogenated conjugated diene polymers by contacting a hydrocarbon solution of said polymers with an aqueous dilute solution of an alpha-hydroxysulfonic acid, separating the aqueous phase from the hydrocarbon phase, removing the hydrocarbon solvent from the hydrocarbon phase, producing a solid polymer, and applying heat and/or vacuum to the solid polymer to remove the residual alpha-hydroxysulfonic acid.

## Claims

### Claim 1

A process for removing transition metal hydrogenation catalyst residues from hydrogenated conjugated diene polymers which comprises (1) contacting a hydrocarbon phase which comprises the hydrogenated polymer, the catalyst residue and a hydrocarbon solvent with an aqueous solution of an alpha-hydroxy-sulfonic acid of the general formula R.sub.1 R.sub.2 COHSO.sub.3 H wherein R.sub.1 and R.sub.2 are individually hydrogen or hydrocarbyl of up to about 7 carbon atoms, (2) separating the aqueous phase from the hydrocarbon phase, (3) removing the hydrocarbon solvent from the hydrocarbon phase, producing a solid polymer phase and (4) applying heat and/or vacuum to the solid polymer to remove residual alpha-hydroxysulfonic acid.

### Claim 2 (depends on 1)

The process of claim 1 wherein the concentration of the alpha-hydroxysulfonic acid in water ranges from about 0.1 to about 10 percent by weight.

### Claim 3 (depends on 2)

The process of claim 2 wherein the acid ranges from about 0.5 to about 7 percent by weight.

### Claim 4 (depends on 1)

The process of claim 1 wherein step 1 is carried out at a temperature of from about 0.degree. C. to about 200.degree. C. and at pressures ranging from about 0.1 to about 20 atmospheres.

### Claim 5 (depends on 1)

The process of claim 1 wherein steam is utilized to accomplish the hydrocarbon removal of step 3 and the residual acid removal of step 4.

### Claim 6 (depends on 1)

The process of claim 1 wherein the catalyst residue comprises a cobalt or nickel catalyst residue.

### Claim 7 (depends on 1)

The process of claim 1 wherein the catalyst residue additionally comprises an aluminum residue.