Polybutene process
AssigneeExxon Chemical Patents Inc.
InventorFrank J. Chen
Life of this patent
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Abstract
Polybutene is prepared from a mixed C.sub.4 hydrocarbon feedstream using an organo-aluminum/HCl catalyst system wherein the HCl is introduced separately into the feedstream to form organochloride in the feedstream. Polybutene product having a very narrow molecular weight distribution is obtained over the M.sub.n range of 700 to 3,000. Dispersants derived from this polybutene exhibit substantially improved performance in lubricating oil compositions.
Claims35
A process for preparing low molecular weight polybutene having an M.sub.n in the range of about 700 to about 3,000 and a molecular weight distribution of about 1.80 to 1.90 from a feedstream mixture of C.sub.4 hydrocarbons containing at least about 6% by weight isobutylene in a tubular reaction zone maintained at a temperature of about -50.degree. C. to +30.degree. C. in the presence of organo-aluminum chloride catalyst, which comprises:
- (a) injecting HCl in an amount of from about 25 to 300 parts by weight per one million parts by weight of said feedstream mixture into said feedstream mixture, in the substantial absence of said organo-aluminum chloride catalyst and under conditions sufficient to substantially completely react said injected HCl with isobutylene, thereby providing a treated feedstream mixture which contains less than 1.0 ppm free HCl;
- (b) simultaneously introducing said treated feedstream mixture and said organo-aluminum chloride catalyst as separate streams into said reaction zone;
- (c) contacting said introduced treated feedstream mixture and said introduced catalyst in the reaction zone for a time and under conditions sufficient to form a polymerization reaction mixture containing said polybutene;
- (d) withdrawing said polymerization reaction mixture from said reaction zone;
- and
- (e) recovering said polybutene product from said withdrawn polymerization reaction mixture.
A continuous process for preparing low molecular weight polybutene having an M.sub.n in the range of from 700 to about 3,000 and a molecular weight distribution of about 1.80 to 1.90 from a feedstream mixture of C.sub.4 hydrocarbons containing at least about 6% by weight isobutylene in a tubular reaction zone maintained at temperatures of about -15.degree. C. to +15.degree. C. in the presence of organo-aluminum chloride catalyst, which comprises:
- (a) injecting HCl in an amount of from about 25 to 300 parts by weight per one million parts by weight of said feedstream mixture into said feedstream mixture, in the substantial absence of said organo-aluminum chloride catalyst and under conditions sufficient to substantially completely react said injected HCl with isobutylene, thereby producing a treated feedstream mixture which contains less than 1.0 ppm free HCl;
- (b) simultaneously continuously introducing said treated feedstream mixture and said organo-aluminum chloride catalyst as separate streams into said reaction zone;
- (c) contacting said introduced treated feedstream mixture and said introduced catalyst in the reaction zone for a time and under conditions sufficient to form a polymerization reaction mixture containing said polybutene;
- (d) continuously withdrawing said polymerization reaction mixture from said reaction zone;
- and
- (e) recovering said polybutene product from said withdrawn polymerization reaction mixture.
Dependencies are inferred from the claim text.