# US 10,479,845 B2 · Process for preparing a halogenated elastomer with improved Mooney viscosity stability

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- Number: US 10,479,845 B2
- Document ID: US10479845B2
- Status: Granted
- Kind: B2
- Application number: 15/500,941
- Filed: 2015-09-11
- Published: 2017-08-10
- Granted: 2019-11-19
- Earliest claimed: 2014-09-30
- Assignees: ExxonMobil Chemical Patents Inc.
- Applicants: ExxonMobil Chemical Patents Inc.
- Inventors: Leming Gu; Stephen T. Dalpe; Mauritz Kelchtermans; Sunny Jacob; John A. Clark; Michael F. McDonald, Jr.; Torri L. Rose
- Web page: https://patentgrep.com/patent/US10479845B2

## CPC

- C08F 8/22: by reaction with free halogens
- C08K 5/13: Phenols; Phenolates
- C08K 5/134: Phenols containing ester groups
- C08K 5/3435: Piperidines
- C08F 2810/50: wherein the polymer is a copolymer and the modification is taking place only on one or more of the monomers present in minority
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)

## Abstract

This invention relates to a method of preparing a brominated elastomer having a stabilized Mooney viscosity. The method includes polymerizing isomonoolefins and at least one polymerizable unit to obtain an elastomer/polymer; brominating the elastomer/polymer to form a brominated elastomer effluent; neutralizing the brominated elastomer effluent to form a neutralized effluent; volatizing off the hydrocarbon solvent; and recovering a brominated elastomer. In at least one point of the process, preferably prior to any significant temperature change in the brominated polymer, a Mooney stabilizer is added into the system. Portions of the Mooney stabilizer may be added at multiple points into the process.

## Claims

### Claim 1

A method of preparing a brominated elastomer, the method comprising:
(a) polymerizing a C4 to C7 isomonoolefin and at least one monomer or other polymerizable unit to obtain a C4 to C7 isomonoolefin derived elastomer;
(b) adding a first portion of a Mooney stabilizer to the C4 to C7 isomonoolefin derived elastomer;
(c) contacting the C4 to C7 isomonoolefin derived elastomer with a halogenating agent and an emulsion in a bromination unit to form a brominated elastomer effluent, wherein an optional portion of the Mooney stabilizer is added to the bromination unit, wherein the emulsion comprises an oxidizing agent, water, solvent, and surfactant;
(d) adding a portion of the Mooney stabilizer to the brominated elastomer effluent;
(e) neutralizing the brominated elastomer effluent with a neutralizing agent and water to form a neutralized effluent, wherein an optional portion of the Mooney stabilizer is added to the neutralized effluent;
(f) volatizing a hydrocarbon solvent from the neutralizing effluent to form a brominated elastomer slurry;
(g) recovering a brominated elastomer from the brominated elastomer slurry, wherein an optional portion of the Mooney stabilizer is added to the recovered brominated elastomer.

### Claim 2 (depends on 1)

The method of claim 1, wherein the Mooney viscosity of the recovered brominated elastomer does not increase by more than about 15 Mooney units when subject to 33° C. for one year.

### Claim 3 (depends on 1)

The method of claim 1, wherein greater than about 500 ppm of Mooney stabilizer is added during the process of preparing the brominated elastomer.

### Claim 4 (depends on 1)

The method of claim 1, wherein the Mooney stabilizer is selected from at least one of a sterically hindered nitroxyl ether, sterically hindered nitroxyl radical, sterically hindered phenolics, phosphites, and combinations thereof.

### Claim 5 (depends on 1)

The method of claim 1, wherein the halogenating agent is selected from at least one of molecular bromine, bromine chloride, hydrogen bromide, and sodium bromide.

### Claim 6 (depends on 1)

The method of claim 1, wherein the oxidizing agent is a material which contains oxygen selected from at least one of a water soluble oxygen containing agent, hydrogen peroxide, organic hydrogen peroxide, sodium chlorate, sodium bromate, sodium hypochlorite, sodium hypobromite, oxides of nitrogen, ozone, urea peroxidate, pertitanic perzirconic, perchromic, permolybdic, pertungstic, perunanic, perboric, perphosphoric, perpyrophosphoric, persulfates, perchloric, perchlorate, and combinations thereof.

### Claim 7 (depends on 1)

The method of claim 1, wherein the oxidizing agent is a water soluble oxygen containing agent.

### Claim 8 (depends on 1)

The method of claim 1, wherein the solvent is selected from at least one of pentane, hexane, heptane, mono-, di-, or tri-halogenated C1 to C6 paraffinic hydrocarbon, methyl chloride, and combinations thereof.

### Claim 9 (depends on 1)

The method of claim 1, wherein the bromination unit is a mixed flow stirred tank, a conventional stirred tank, a packed tower, or a pipe.

### Claim 10 (depends on 1)

An article made from the brominated elastomer prepared by the method of claim 1, wherein the article is a tire innerliner or a tire bladder or is incorporated as a layer into a tire, a bladder, a hose, a belt, pneumatic spring, or vehicle body mount.