Production of highly reactive low molecular weight PIB oligomers
View Patent ↗In one preferred embodiment, the present invention provides a process for the liquid phase polymerization of isobutylene to manufacture highly reactive PIB oligomers having Mn under 1000, using a catalyst composition comprising a Friedel-Crafts catalyst a complexing agent, a chain transfer agent and a polymerization-retarding agent. A chain transfer agent may be selected from: α-DIB and β-DIB and mixtures thereof. A polymerization-retarding agent may be selected from:
1. A liquid phase polymerization process of isobutylene to manufacture highly reactive polyisobutylene (PIB) having Mn under 1000 and at least 50% 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 an olefinic chain transfer agent (“CTA”);
d) providing a polymerization-retarding agent;
e) introducing said feedstock, said catalyst composition, said chain transfer agent and said polymerization-retarding agent into a reaction zone to form a reaction mixture;
f) intimately intermixing the reaction mixture in said reaction zone;
g) optionally adding a modifier;
h) maintaining the reaction mixture in its intimately intermixed condition to thereby cause the isobutylene therein to undergo polymerization to form polyisobutylene; and
i) withdrawing a product stream comprising low molecular weight, highly reactive polyisobutylene from said reaction zone.
2. The process of claim 1 , wherein said PIB has Mn under 800 and the polymerization-retarding agent comprises a phenolic compound.
3. The process of claim 1 , wherein said PIB has Mn weight under 500.
4. The process of claim 1 , wherein said Friedel-Crafts catalyst comprises BF 3 and said complexing agent is an alcohol.
5. The process of claim 1 , wherein said CTA is 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.
6. The process of claim 5 , wherein said CTA is α-DIB.
7. The process of claim 5 , wherein said CTA is β-DIB.
8. The process of claim 5 , wherein said CTA is a mixture of α-DIB and β-DIB.
9. The process according to claim 1 , wherein the polymerization-retarding agent comprises a phenolic compound.
10. The process according to claim 1 , wherein the polymerization-retarding agent is a hindered phenol.
11. The process according to claim 1 , wherein the polymerization-retarding agent is present in an amount of from 5 to 500 ppm by weight of the polyisobutylene composition.
12. The process according to claim 1 , wherein the polymerization-retarding agent is present in an amount of from 10 to 100 ppm by weight of the polyisobutylene composition.