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US4358560A
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US
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Stabilized slurries of isoolefin polymers
Assignee: ExxonMobil Technology and Engineering Co
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Filing: 1981-02-23
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Granted: 1982-11-09
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Expires: 2001-02-23
Abstract
Abstract Polymerization slurries of elastomeric isoolefin homopolymers and copolymers, such as butyl rubber, in diluents such as methyl chloride are effectively stabilized against agglomeration of polymer particles through addition of minor proportions of (i) a preformed copolymer stabilizer having both a lyophobic or lyophilic portion, or (ii) an in situ formed stabilizer from a functional lyophilic stabilizer precursor capable of copolymerizing or otherwise chemically bonding with the polymer product. Agglomeration of polymer products is effectively prevented, yielding a number of significant processing advantages. The process is especially adaptable to the production of isobutylene-isoprene butyl rubber.
Inventors
- 👤 Kenneth W. Powers
- 👤 Ralph H. Schatz
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 22:16
CPC Classifications
C; C08; C08F; C08F10/00; C08F10/04; C08F10/08; C08F10/10; C08F210/00; C08F210/04; C08F210/08; C08F210/10; Y; Y10; Y10S; Y10S524/00; Y10S524/923
Claims Analysis
Total Claims: 20
Claim 1
Independent Claim
154 words
A method of stabilizing a polymerization slurry against agglomeration, said slurry being formed in a cationic Lewis Acid catalyzed polymerization process, and containing as product polymers, polymerized C 4 -C 7 isoolefin homopolymers or butyl rubber copolymers in a polymerization diluent selected from the group consisting of methyl chloride, methylene chloride, vinyl chloride or ethyl chloride diluents, which comprises incorporating into the reaction mixture, said reaction mixture containing monomers, catalyst and diluent, or into the polymerization product slurry about 0.05% to 20% by weight, based upon the weight of product polymers, of a stabilizing agent, said stabilizing agent being a preformed copolymer having a lyophilic, polymerization diluent soluble portion and a lyophobic, polymerization diluent insoluble portion, said lyophobic portion being soluble in or adsorbable by said product polymer and said stabilizing agent being capable of forming an adsorbed solubilized polymer coating around the precipitated isoolefin homopolymer or butyl rubber copolymer to stabilize said slurry.
Claim 2
Independent Claim
154 words
A method of stabilizing a polymerization slurry against agglomeration, said slurry being formed in a cationic Lewis Acid catalyzed polymerization process, and containing as product polymers, polymerized C 4 -C 7 isoolefin homopolymers or butyl rubber copolymers in a polymerization diluent selected from the group consisting of methyl chloride, methylene chloride, vinyl chloride or ethyl chloride diluents, which comprises incorporating into the reaction mixture, said reaction mixture containing monomers, catalyst and diluent, or into the polymerization product slurry about 0.05% to 20% by weight, based upon the weight of product polymers, of a stabilizing agent, said stabilizing agent being a preformed copolymer having a lyophilic, polymerization diluent soluble portion and a lyophobic, polymerization diluent insoluble portion, said lyophobic portion being soluble in or adsorbable by said product polymer and said stabilizing agent being capable of forming an adsorbed solubilized polymer coating around the precipitated isoolefin homopolymer or butyl rubber copolymer to stabilize said slurry.
Claim 3
Dependent Claim
11 words
The method of claim 1 wherein the diluent is methyl chloride.
Claim 4
Dependent Claim
15 words
The method of claim 1 wherein the product polymer is butyl rubber or polyisobutylene homopolymer.
Claim 5
Dependent Claim
24 words
The method of claim 3 wherein the product polymer is isobutylene-isoprene butyl rubber having a viscosity average molecular weight of about 100,000 to 800,000.
Claim 6
Dependent Claim
28 words
The method of claim 3 wherein the isobutyleneisoprene butyl rubber has a viscosity average molecular weight of about 250,000 to about 600,000 and the diluent is methyl chloride.
Claim 7
Dependent Claim
13 words
The method of claim 1 wherein the stabilizing agent is the preformed copolymer.
Claim 8
Dependent Claim
59 words
The method of claim 6 wherein the lyophilic portion of the preformed copolymer is a member of the group consisting of polystyrene, polyvinyl chloride, polyvinyl bromide, neoprene and mono-, di- and trisubstituted polystyrenes, the substituents being halogen or C 1 -C 5 alkyl groups, the lyophilic portion having a degree of polymerization of from about 20 to about 6,000.
Claim 9
Dependent Claim
63 words
The method of claim 7 wherein the lyophobic portion of the preformed copolymer is a member of the group of polymerized C 4 -C 7 isoolefins, butyl rubber copolymers, polybutadiene, polyisoprene, ethylene-propylene copolymers, EPDM terpolymers, hydrogenated diene polymers, styrene/butadiene random copolymers of low styrene content (SBR rubbers), and polydimethyl silicone, the lyophobic portion having a degree of polymerization of at least about 10.
Claim 10
Dependent Claim
11 words
The method of claim 6 wherein the diluent is methyl chloride.
Claim 11
Dependent Claim
10 words
A stabilized slurry produced by the method of claim 1.
Claim 12
Dependent Claim
10 words
A stabilized slurry produced by the method of claim 3.
Claim 13
Dependent Claim
16 words
A stabilized slurry produced by the method of claim 3 wherein the diluent is methyl chloride.
Claim 14
Independent Claim
89 words
A method of preparing non-agglomerating homopolymers of C 4 -C 7 isoolefins or butyl rubber copolymers by Lewis Acid cationic polymerization of corresponding monomers at temperatures from about -90° C. to about -20° C. in a polymerization slurry diluent selected from the group consisting of methyl chloride, methylene chloride, vinyl chloride and ethyl chloride diluents in the presence of a stabilizer copolymer, the stabilizer copolymer being a preformed copolymer having a lyophilic diluent soluble portion and a lyophobic diluent insoluble but isoolefin or butyl rubber soluble or adsorbable portion.
Claim 15
Independent Claim
89 words
A method of preparing non-agglomerating homopolymers of C 4 -C 7 isoolefins or butyl rubber copolymers by Lewis Acid cationic polymerization of corresponding monomers at temperatures from about -90° C. to about -20° C. in a polymerization slurry diluent selected from the group consisting of methyl chloride, methylene chloride, vinyl chloride and ethyl chloride diluents in the presence of a stabilizer copolymer, the stabilizer copolymer being a preformed copolymer having a lyophilic diluent soluble portion and a lyophobic diluent insoluble but isoolefin or butyl rubber soluble or adsorbable portion.
Claim 16
Dependent Claim
26 words
The method of claim 13 wherein the butyl rubber is isobutylene-isoprene butyl rubber, the Lewis Acid catalyst is AlCl 3 and the diluent is methyl chloride.
Claim 17
Dependent Claim
22 words
The method of claim 13 wherein the isoolefin homopolymer is polyisobutylene, the catalyst is AlCl 3 and the diluent is methyl chloride.
Claim 18
Dependent Claim
22 words
The method of claim 13 in which the slurry contains up to about 50% by weight butyl rubber copolymer or isoolefin homopolymer.
Claim 19
Dependent Claim
23 words
The product produced by the method of claim 16 wherein the butyl rubber is isobutylene-isoprene butyl rubber and the diluent is methyl chloride.
Claim 20
Dependent Claim
21 words
The product produced by the method of claim 16 wherein the isoolefin homopolymer is polyisobutylene and the diluent is methyl chloride.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1985-11-08 | 1986-05-10 | 1986-11-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-11-08 | 1990-05-10 | 1990-11-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-11-08 | 1994-05-10 | 1994-11-09 | $7700.00 | Window Closed / Lapsed |