EP0111391A2
Expired / Lapsed
EP
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Polymer molecular weight reduction process
Assignee: Polysar Ltd
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Filing: 1983-11-07
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Granted: —
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Expires: 2003-11-07
Abstract
Abstract A process for modifying a polymer, to obtain a polymer having a molecular weight lower than the unmodified polymer, comprises masticating a polymer in bulk form and selected from rubbery synthetic unsaturated polymers and natural rubber, using rubber mixing and masticating means at from 20 to 220°C while being exposed to, and in contact with, an atmosphere containing from 0.1 to 4% by volume of ozone.
Inventors
- 👤 Douglas Cameron Edwards
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-04 02:41
CPC Classifications
C; C08; C08F; C08F8/00; C08F8/50; B; B29; B29C; B29C48/00; B29C48/25; B29C48/36; B29C48/395; B29C48/40; B29C48/50; B29C48/505; B29C48/625; B29C48/76; B29C48/765; B29C48/766; B29C48/92; C08C; C08C19/00; C08C19/08; B29C2948/00; B29C2948/92; B29C2948/92504; B29C2948/92514; B29C2948/92704; B29C48/022; B29C48/78; B29C48/80; B29C48/802; C08F2810/00; C08F2810/10; C08F2810/20
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
67 words
A process for modifying a polymer, to obtain a polymer having a molecular weight lower than the unmodified polymer, which comprises masticating a polymer in bulk form and selected from rubbery synthetic unsaturated polymers and natural rubber, using rubber mixing and masticating means at from 20 to 220°C while being exposed to, and in contact with, an atmosphere containing from 0.1 to 4% by volume of ozone.
Claim 2
Dependent Claim
67 words
A process for modifying a polymer, to obtain a polymer having a molecular weight lower than the unmodified polymer, which comprises masticating a polymer in bulk form and selected from rubbery synthetic unsaturated polymers and natural rubber, using rubber mixing and masticating means at from 20 to 220°C while being exposed to, and in contact with, an atmosphere containing from 0.1 to 4% by volume of ozone.
Claim 3
Dependent Claim
19 words
A process according to claim 1, wherein the mastication is conducted in an internal mixer or a mixing extruder.
Claim 4
Dependent Claim
49 words
A process according to claim 2, wherein the mastication is conducted in an internal mixer of the Banbury-type of the trough-type equipped with sigma- or Z-blades, or in an extruder having single or twin extruder screws and having mixing and shearing components along the length of the extruder screw.
Claim 5
Dependent Claim
50 words
A process according to claim 2 or claim 3, wherein the temperature of the polymer is from 20 to 100°C, if an internal mixer is used, or from 100 to 180°C, if an extruder is used, in which case the extruder has an L/D ratio of not less than 10.
Claim 6
Dependent Claim
24 words
A process according to any preceding claim, wherein the unmodified polymer is natural rubber or a polymer comprising C 4 -C 6 conjugated diolefins.
Claim 7
Dependent Claim
83 words
A process according to claim 5, wherein the unmodified polymer is polybutadiene, polyisoprene, a polymer of isobutylene and a C 4 -C 6 conjugated diolefin, a brominated or chlorinated polymer.of isobutylene and a C 4 -C 6 conjugated diolefin, isobutylene-isoprene- divinylbenezene polymer, an isobutylene-isoprene-2,5-dimethyl-1,5-hexadiene polymer, a polymer of a C 4 -C 6 conjugated diolefin and a vinyl or vinylidene-substituted aromatic hydrocarbon, or a polymer of a C 4 -C 6 conjugated diolefin and a C 3 -C 5 unsaturated nitrile group-containing monomer.
Claim 8
Dependent Claim
80 words
A process for modifying a polymer, to obtain a polymer having a molecular weight lower than the unmodified polymer, which comprises masticating natural rubber or a polymer (optionally brominated or chlorinated) of isobutylene and a C 4 -C 6 conjugated diolefin, in bulk form, in an extruder having an L/D ratio of not less than 10, at from 100 to 180°C, while being exposed to, and in contact with, an atmosphere containing from 0.3 to 2% by volume of ozone.
Claim 9
Dependent Claim
80 words
A process for modifying a polymer, to obtain a polymer having a molecular weight lower than the unmodified polymer, which comprises masticating natural rubber or a polymer (optionally brominated or chlorinated) of isobutylene and a C 4 -C 6 conjugated diolefin, in bulk form, in an extruder having an L/D ratio of not less than 10, at from 100 to 180°C, while being exposed to, and in contact with, an atmosphere containing from 0.3 to 2% by volume of ozone.
Claim 10
Dependent Claim
21 words
A process according to claim 6 or claim 7, wherein the unmodified polymer is an isobutylene-butadiene, isobutylene-isoprene, isobutylene-piperylene or isobutylene-dimethylbutadiene polymers.
Claim 11
Dependent Claim
25 words
A process according to claim 8, wherein the unmodified polymer is of 95 to 99.5% by weight isobutylene and 0.5 to 5% by weight isoprene.
Claim 12
Dependent Claim
71 words
1 0. A process according to claim 6 or claim 7, wherein the unmodified polymer is a brominated isobutylene-isoprene polymer containing from 92.5 to 98.7% by weight isobutylene, from 0.6 to 3.5% by weight isoprene and from 0.7 to 4% by weight bromine, or a chlorinated isobutylene-isoprene polymer containing from 94.7 to 98.7% by weight isobutylene, from 0.8 to 3.3% by weight isoprene and from 0.5 to 2% by weight chlorine.
Claim 13
Dependent Claim
20 words
A process according to any preceding claim, wherein the temperature of the atmosphere containing ozone is from 15 to 40°C.
References Cited (Backward Citations)
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