Claims
- 1. A process for producing a low molecular weight isoolefin polymer which comprises the step of contacting, in the melt phase, in a conversion zone, at conversion conditions, a high molecular weight copolymer of an isoolefin having from 4 to 7 carbon atoms and a para-alkylstyrene, with an initiator selected from the group consisting of molecular oxygen-containing gas at a pressure of at least 1 lb. per square inch gauge, an organic peroxide having a 10-hour 1/2-life temperature greater than about 110.degree. C., an azo compound having a 10-hour 1/2-life temperature greater than about 110.degree. C., to produce a conversion product including a lower molecular weight isoolefin polymer having a molecular weight distribution at least equal to the molecular weight distribution of said high molecular weight copolymer.
- 2. The process of claim 1, wherein said high molecular weight copolymer has a number average molecular weight above about 100,000.
- 3. The process of claim 1 wherein said lower molecular weight isoolefin polymer has a number average molecular weight ranging from about 1 to about 75 percent of the number average molecular weight of said high molecular weight copolymer.
- 4. The process of claim 1, wherein said initiator is an organic peroxide.
- 5. The process of claim 4, wherein said copolymer is a copolymer of isobutylene and para-methylstyrene.
- 6. The process of claim 1, wherein said initiator is a molecular oxygen-containing gas selected from the group consisting of oxygen, air and mixtures thereof.
- 7. The process of claim 1, wherein said molecular oxygen-containing gas comprises air.
- 8. The process of claim 1, wherein said initiator is an organic peroxide selected from the group consisting of dicumyl peroxide; alpha, alpha-bis (t-butylperoxy) diisopropylbenzene; 2,5-dimethyl-2,5-di(t-butylperoxy) hexane; t-butyl cumyl peroxide; di-t-butyl peroxide; 2,5-dimethyl-2,5-di(t-butylperoxy)hexyne, and mixtures thereof.
- 9. The process of claim 1, wherein said initiator is an azo compound selected from the group consisting of azo ethers, azo esters, and mixtures thereof.
- 10. The process of claim 1, wherein said conversion conditions include a temperature ranging from about 75.degree. to about 275.degree. C.
- 11. The process of claim 1, wherein said conversion conditions include a temperature ranging from about 150.degree. to about 250.degree. C.
- 12. The process of claim 1 wherein said conversion product is subjected to a devolatization step to remove volatile products and, thereby, produce a devolatilized product, said devolatilized product comprising solid particles and wherein said devolatilized product is filtered to remove at least a portion of said solid particles.
- 13. The process of claim 12, wherein the resulting filtered product is passed to a heat exchange zone to decrease its temperature.
- 14. The process of claim 1, wherein said contacting step is conducted in an internal mixer.
- 15. The process of claim 14, wherein said internal mixer is an extruder.
- 16. The process of claim 1 wherein prior to said contacting step said high molecular weight copolymer is heated to a temperature ranging from about 75.degree. to about 250.degree. C., and wherein, subsequently, the resulting heated high molecular weight copolymer is mixed with said initiator in a conversion zone for a sufficient time to produce said conversion product.
- 17. The process of claim 1 wherein said high molecular weight polymer is a copolymer of isobutylene and para-methylstyrene and wherein said lower molecular weight copolymer is a copolymer of isobutylene and a para-methylstyrene having a number average molecular weight ranging from 50,000 to 200,000.
- 18. The process of claim 1, wherein said initiator is an organic peroxide and wherein said organic peroxide is present in said conversion zone at a pressure ranging from about 1 to about 1000 pounds per square inch gauge and in an amount ranging from about 0.0005 to about 0.5 weight percent, active oxygen, based on the weight of said higher molecular weight copolymer.
- 19. The process of claim 1, wherein said high molecular weight copolymer is masticated during said contacting step with said initiator.
- 20. The process of claim 19, wherein said mastication is performed in an extruder.
- 21. The process of claim 20, wherein said high molecular weight copolymer is introduced into said extruder at a rate ranging from about 50 to about 200 kg per hour, said extruder having a screw diameter of 2 inches.
Parent Case Info
This is a continuation of application Ser. No. 572,569, filed Aug. 23, 1990, now abandoned.
US Referenced Citations (5)
Foreign Referenced Citations (5)
Number |
Date |
Country |
726234 |
Dec 1967 |
BEX |
0035677 |
Sep 1981 |
EPX |
0111391 |
Jun 1984 |
EPX |
0180444 |
May 1986 |
EPX |
1293671 |
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GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
527569 |
Aug 1990 |
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