Granted Patent B2

US 8,524,843 · App. 13/489,064 · Granted Sep 3, 2013

Abstract

Claims (28)

1. A liquid phase polymerization process of isobutylene to manufacture highly reactive polyisobutylene (PIB) having Mn under 1000 and at least 70% terminal double bonds, said process comprising:

a) providing a feedstock comprising isobutylene;

b) providing a catalyst composition comprising a Friedel-Crafts catalyst and a complexing agent therefor;

c) providing a CTA (chain transfer agent) selected from the group consisting of 2,4,4-trimethyl-1-pentene (α-DIB), 2,4,4-trimethyl-2-pentene (β-DIB), 2-ethyl-1-hexene, 2-methyl-1-pentene and mixtures thereof;

d) introducing said feedstock, said catalyst composition and said chain transfer agent into a reaction zone to form a reaction mixture;

e) intimately intermixing the reaction mixture in said reaction zone;

f) optionally adding a modifier;

g) maintaining the reaction mixture in its intimately intermixed condition and keeping it at a temperature of about 20-110° F. in the reaction zone, to thereby cause the isobutylene therein to undergo polymerization to form polyisobutylene;

h) withdrawing a product stream comprising low molecular weight, highly reactive polyisobutylene from said reaction zone; and optionally

i) controlling the introduction of said feedstock into said reaction zone and the withdrawal of said product stream from the reaction zone such that the residence time of the isobutylene undergoing polymerization in the reaction zone is no greater than about 4 minutes.

2. The process of claim 1 , wherein said PIB has Mn under 800.

3. The process of claim 1 , wherein said PIB has Mn weight under 500.

4. The process of claim 1 , wherein said PIB has Mn under 300.

5. The process of claim 1 , wherein said Friedel-Crafts catalyst comprises BF 3 .

6. The process of claim 1 , wherein said complexing agent is an alcohol.

7. The process of claim 1 , wherein said CTA is α-DIB.

8. The process of claim 1 , wherein said CTA is β-DIB.

9. The process of claim 1 , wherein said CTA is a mixture of α-DIB and β-DIB.

10. The process of claim 1 , wherein the polydispersity of said polyisobutylene is from 1.1 to 1.5.

11. The process of claim 1 , wherein the polydispersity of said polyisobutylene is no more than about 2.0.

12. The process of claim 1 , wherein the polydispersity of said polyisobutylene no more than about 1.65.

13. The process of claim 10 , wherein said CTA is a mixture of α-DIB and β-DIB in an 80:20 molar ratio.

14. The process of claim 1 , wherein the polydispersity of said polyisobutylene is from 1.1 to 1.4.

15. A polyisobutylene composition comprising a chain transfer agent selected from the group consisting of 2,4,4-trimethyl-1-pentene, 2,4,4-trimethyl-2-pentene, 2-ethyl-1-hexene, 2-methyl-1-pentene and mixtures thereof, having Mn under 1000 exhibiting a multimodal molecular weight distribution, at least 70% terminal double bonds and a polydispersity under 2.0 prepared using a low molecular weight chain transfer agent, characterized in that the composition exhibits a low molecular weight relative maximum in its molecular weight distribution corresponding to the presence of said chain transfer agent.

16. The composition of claim 15 , characterized in that the composition exhibits a low molecular weight relative maximum in its molecular weight distribution corresponding to the presence of said chain transfer agent at a content of from 2 weight percent to 20 weight percent of the composition.

17. The composition of claim 15 , characterized in that the composition exhibits a low molecular weight relative maximum in its molecular weight distribution corresponding to the presence of said chain transfer agent at a content of from 4 weight percent to 10 weight percent of the composition.

18. The composition of claim 15 wherein the polydispersity of said composition is no more than about 1.65.

19. The composition of claim 15 , wherein the polydispersity of said composition is from 1.1 to 1.5.

Assignments (20)