US4252710A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Stabilized slurries of isoolefin polymers
Assignee: ExxonMobil Technology and Engineering Co
•
Filing: 1979-08-02
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Granted: 1981-02-24
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Expires: 1999-08-02
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 21:43
CPC Classifications
C; C08; C08F; C08F2/00; C08F10/00; C08F10/04; C08F10/08; C08F10/10; C08F210/00; C08F210/04; C08F210/08; C08F210/10; C08F210/12
Claims Analysis
Total Claims: 36
Claim 1
Independent Claim
258 words
A method of stabilizing a polymerization slurry against agglomeration, the 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, the 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, the stabilizing agent being (i) a preformed copolymer having a lyophilic, polymerization diluent soluble portion and a lyophobic polymerization diluent insoluble portion, the lyophobic portion being soluble in or adsorbable by the product polymer and the stabilizing agent being capable of forming an adsorbed solubilized polymer coating around the precipitated isoolefin homopolymer or butyl copolymer to stabilize the slurry, provided that the stabilizing agent, when incorporated into the reaction mixture, is free of cationically active unsaturation or functional groups, or (ii) an in situ formed stabilizing agent copolymer formed from a stabilizer precursor, the stabilizer precursor being a lyophilic polymer containing a functional group capable of copolymerizing or forming a chemical bond with the product polymer, the functional group being a cationically active halogen or cationically active unsaturation, the lyophobic portion of the stabilizing agent being product polymer, the stabilizing agent so formed being capable of forming an adsorbed solubilized polymer coating around the precipitated product polymer to stabilize the product polymer slurry.
Claim 2
Independent Claim
258 words
A method of stabilizing a polymerization slurry against agglomeration, the 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, the 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, the stabilizing agent being (i) a preformed copolymer having a lyophilic, polymerization diluent soluble portion and a lyophobic polymerization diluent insoluble portion, the lyophobic portion being soluble in or adsorbable by the product polymer and the stabilizing agent being capable of forming an adsorbed solubilized polymer coating around the precipitated isoolefin homopolymer or butyl copolymer to stabilize the slurry, provided that the stabilizing agent, when incorporated into the reaction mixture, is free of cationically active unsaturation or functional groups, or (ii) an in situ formed stabilizing agent copolymer formed from a stabilizer precursor, the stabilizer precursor being a lyophilic polymer containing a functional group capable of copolymerizing or forming a chemical bond with the product polymer, the functional group being a cationically active halogen or cationically active unsaturation, the lyophobic portion of the stabilizing agent being product polymer, the stabilizing agent so formed being capable of forming an adsorbed solubilized polymer coating around the precipitated product polymer to stabilize the product polymer 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 isobutylene-isoprene 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, ethylenepropylene 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
18 words
The method of claim 1 wherein the in situ stabilizing agent formed from the stabilizer precursor is employed.
Claim 12
Dependent Claim
17 words
The method of claim 10 wherein the lyophilic stabilizer precursor contains cationically active pendant or enchained halogen.
Claim 13
Dependent Claim
15 words
The method of claim 11 wherein the lyophile is polystyrene and the halogen is chlorine.
Claim 14
Dependent Claim
31 words
The method of claim 12 wherein the lyophile is prepared by free radical polymerization of styrene in the presence of carbon tetrachloride or by copolymerization of styrene with vinyl benzyl chloride.
Claim 15
Dependent Claim
14 words
The method of claim 10 wherein the lyophile is polystyrene containing cationically active unsaturation.
Claim 16
Dependent Claim
26 words
The method of claim 14 wherein the lyophilic styrene polymer is prepared by anionically polymerizing styrene and capping it with vinyl benzyl chloride or methallyl chloride.
Claim 17
Dependent Claim
25 words
The method of claim 10 wherein the stabilizer precursor is a functional polystyrene having a number average molecular weight of from about 5,000 to 150,000.
Claim 18
Dependent Claim
24 words
The method of claim 10 wherein the product polymer is isobutylene-isoprene butyl rubber having a viscosity average molecular weight of about 100,000 to 800,000.
Claim 19
Dependent Claim
31 words
The method of claim 17 wherein the catalyst is AlCl 3 the diluent is methyl chloride, and the butyl rubber has a viscosity average molecular weight of about 250,000 to 600,000.
Claim 20
Dependent Claim
12 words
The method of claim 10 wherein the product polymer is polyisobutylene homopolymer.
Claim 21
Dependent Claim
17 words
The method of claim 19 wherein the catalyst is AlCl 3 and the diluent is methyl chloride.
Claim 22
Dependent Claim
10 words
A stabilized slurry produced by the method of claim 1.
Claim 23
Dependent Claim
10 words
A stabilized slurry produced by the method of claim 3.
Claim 24
Dependent Claim
16 words
A stabilized slurry produced by the method of claim 3 wherein the diluent is methyl chloride.
Claim 25
Dependent Claim
11 words
A stabilized slurry produced according to the method of claim 10.
Claim 26
Dependent Claim
11 words
A stabilized slurry produced according to the method of claim 18.
Claim 27
Dependent Claim
11 words
A stabilized slurry produced according to the method of claim 20.
Claim 28
Independent Claim
151 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 either (i) a preformed copolymer having a lyophilic diluent soluble portion and a lyophobic diluent insoluble but isoolefin or butyl rubber soluble or adsorbable portion, the preformed stabilizer being free of cationically active unsaturation or functional groups or (ii) an in situ formed stabilizer copolymer formed from a stabilizer precursor being a lyophilic polymer containing a functional group capable of copolymerizing or forming a chemical bond with the isoolefin homopolymer or butyl rubber copolymer, the functional group being cationically active halogen or cationically active unsaturation.
Claim 29
Independent Claim
151 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 either (i) a preformed copolymer having a lyophilic diluent soluble portion and a lyophobic diluent insoluble but isoolefin or butyl rubber soluble or adsorbable portion, the preformed stabilizer being free of cationically active unsaturation or functional groups or (ii) an in situ formed stabilizer copolymer formed from a stabilizer precursor being a lyophilic polymer containing a functional group capable of copolymerizing or forming a chemical bond with the isoolefin homopolymer or butyl rubber copolymer, the functional group being cationically active halogen or cationically active unsaturation.
Claim 30
Dependent Claim
26 words
The method of claim 27 wherein the butyl rubber is isobutylene-isoprene butyl rubber, the Lewis Acid catalyst is AlCl 3 and the diluent is methyl chloride.
Claim 31
Dependent Claim
14 words
The method of claim 27 wherein the stabilizer is the in situ formed stabilizer.
Claim 32
Dependent Claim
16 words
The method of claim 29 wherein the functional lyophile is a functional styrene polymer stabilizer precursor.
Claim 33
Dependent Claim
22 words
The method of claim 27 wherein the isoolefin homopolymer is polyisobutylene, the catalyst is AlCl 3 and the diluent is methyl chloride.
Claim 34
Dependent Claim
22 words
The method of claim 27 in which the slurry contains up to about 50% by weight butyl rubber copolymer or isoolefin homopolymer.
Claim 35
Dependent Claim
23 words
The product produced by the method of claim 32 wherein the butyl rubber is isobutylene-isoprene butyl rubber and the diluent is methyl chloride.
Claim 36
Dependent Claim
21 words
The product produced by the method of claim 32 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) | 1984-02-24 | 1984-08-25 | 1985-02-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-02-24 | 1988-08-25 | 1989-02-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-02-24 | 1992-08-25 | 1993-02-24 | $7700.00 | Window Closed / Lapsed |