# US 5,345,030 A · Inhibiting popcorn polymer formation with sulfur-containing compounds

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- Number: US 5,345,030 A
- Document ID: US5345030A
- Status: Granted
- Kind: A
- Application number: 08/029,859
- Filed: 1993-03-11
- Granted: 1994-09-06
- Earliest claimed: 1991-01-29
- Assignees: Exxon Chemical Patents Inc.
- Inventors: Hsiang-ning Sun; John J. Cikut; Roque V. Martir; Jos P. Wristers
- Web page: https://patentgrep.com/patent/US5345030A

## CPC

- C09K 15/12: containing sulfur and oxygen
- C07C 7/20: Use of additives, e.g. for stabilisation
- Y10S 585/95: Prevention or removal of corrosion or solid deposits
- C09K: MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C07C: ACYCLIC OR CARBOCYCLIC COMPOUNDS
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

Inhibition of popcorn polymer growth by treatment with a sulfur-containing compound. The sulfur-containing compound can be added to organic material from which popcorn polymer is formed, or applied to extant popcorn polymer.

## Claims

### Claim 1

A method for treating organic material to prevent the formation of popcorn polymer growth, comprising treatment of said organic material with at least one mercaptan, said treatment comprising addition of said at least one mercaptan to said organic material, said addition being selected from the group consisting of continuous addition and intermittent addition.

### Claim 2 (depends on 1)

The method of claim 1, wherein said at least one mercaptan is provided in a concentration of from about 0.1 to about 100,000 wppm of said organic material.

### Claim 3 (depends on 2)

The method of claim 2, wherein said at least one mercaptan is provided in a concentration of from about 5 to about 1000 wppm of said organic material.

### Claim 4 (depends on 3)

The method of claim 3, wherein said at least one mercaptan is provided in a concentration of from about 5 to about 100 wppm of said organic material.

### Claim 5 (depends on 1)

The method of claim 1, wherein said addition is intermittent addition.

### Claim 6 (depends on 1)

The method of claim 1, wherein said addition is continuous addition.

### Claim 7 (depends on 1)

The method of claim 1, wherein said at least one mercaptan comprises at least one aromatic mercaptan, and said organic material comprises at least one aromatic monomer.

### Claim 8 (depends on 7)

The method of claim 7, wherein said at least one mercaptan comprises methyl mercaptan, and said organic material comprises 1,3 butadiene.

### Claim 9 (depends on 7)

The method of claim 7, wherein said at least one mercaptan comprises ethyl mercaptan, and said organic material comprises 1,3 butadiene.

### Claim 10 (depends on 7)

The method of claim 7, wherein said at least one mercaptan comprises methyl mercaptan, and said organic material comprises isoprene.

### Claim 11 (depends on 7)

The method of claim 7, wherein said at least one mercaptan comprises ethyl mercaptan, and said organic material comprises isoprene.

### Claim 12 (depends on 1)

The method of claim 1, wherein said treatment is conducted in the substantial absence of organic material from which said popcorn polymer is formed.

### Claim 13 (depends on 12)

The method of claim 12, wherein said treatment is conducted at a temperature of between about 20.degree. C. and about 100.degree. C. and for a period of between about 15 minutes and about 100 hours, and wherein the vapor pressure of said at least one mercaptan is between about 0.1 atmospheres and about 3.0 atmospheres.

### Claim 14 (depends on 12)

The method of claim 12, wherein said at least one mercaptan comprises at least one aromatic mercaptan, and wherein said organic material comprises at least one aromatic monomer.

### Claim 15 (depends on 14)

The method of claim 14, wherein said at least one aromatic mercaptan comprises thiophenol, and wherein said at least one aromatic monomer comprises styrene.

### Claim 16 (depends on 14)

The method of claim 14, wherein said at least one mercaptan is selected from the group consisting of methyl mercaptan and ethyl mercaptan, and wherein said organic material is selected from the group consisting of 1,3-butadiene and isoprene.

### Claim 17

A method for treating an organic material to prevent the formation of popcorn polymer growth, comprising treatment of said organic material with hydrogen sulfide, said treatment comprising addition being intermittent.