Copolyether glycol manufacturing process
AssigneeInvista North America S.A R.L.
InventorsQun Sun, Gary L. Kiser, Robert D. Orlandi
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Abstract
The present invention provides a highly efficient process for manufacturing copolyether glycol having a mean molecular weight of from about 650 to about 5000 dalton by polymerization of tetrahydrofuran and at least one alkylene oxide in the presence of an acid catalyst and at least one compound containing reactive hydrogen atoms. More particularly, the invention relates to a process for manufacturing copolyether glycol which comprises recycle to the polymerization reaction step of at least a portion of the oligomeric cyclic ether which is co-produced with the copolyether glycol, said process exhibiting an Space Time Yield value of greater than about 0.9.
Claims25
A process for manufacturing copolyether glycol having a mean molecular weight of from about 650 dalton to about 5000 dalton, said process exhibiting an STY of greater than about 0.9 g polyol/g cat.hr, comprising the steps of:
- a) polymerizing feed comprising a tetrahydrofuran and at least one alkylene oxide in the presence of an acid catalyst and at least one compound containing reactive hydrogen atoms at a temperature of from about 50° C. to about 80° C. to produce a polymerization product mixture comprising OCE, copolyether glycol, at least one dimer of the alkylene oxide, linear short chain copolyether glycol and tetrahydrofuran;
- b) separating a majority of the tetrahydrofuran and the dimer of the alkylene oxide from the polymerization product mixture of step a) to produce a crude product mixture comprising OCE, copolyether glycol and linear short chain copolyether glycol;
- c) separating at least a portion of the OCE and linear short chain copolyether glycol from the crude product mixture of step b) to produce an OCE stream comprising OCE and linear short chain copolyether glycol, and a product stream comprising copolyether glycol;
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- d) recycling at least a portion of the OCE stream of step c) to the polymerization step a) such that the feed comprises from about 3 to about 15 wt % OCE.
A process for manufacturing poly(tetramethylene-co-ethyleneether) glycol having a mean molecular weight of from about 650 dalton to about 5000 dalton, said process exhibiting an STY of greater than about 0.9 g polyol/g cat.hr, comprising the steps of:
- a) polymerizing feed comprising tetrahydrofuran and ethylene oxide in the presence of an acid catalyst and at least one compound containing reactive hydrogen atoms selected from the group consisting of water, 1,4-butanediol, poly(tetramethylene ether) glycol having a molecular weight of from about 130 dalton to about 400 dalton, and poly(tetramethylene-co-ethyleneether) glycol having a molecular weight of from about 130 dalton to about 400 dalton, at a temperature of from about 50° C. to about 80° C., to produce a polymerization product mixture comprising OCE, poly(tetramethylene-co-ethyleneether) glycol, 1,4-dioxane, linear short chain copolyether glycol and tetrahydrofuran;
- b) separating a majority of the tetrahydrofuran and 1,4-dioxane from the polymerization product mixture of step a) to produce a crude product mixture comprising OCE, poly(tetramethylene-co-ethyleneether) glycol and linear short chain copolyether glycol;
- c) separating at least a portion of the OCE and linear short chain copolyether glycol from the crude product mixture of step b) to produce an OCE stream comprising OCE and linear short chain copolyether glycol, and a product stream comprising poly(tetramethylene-co-ethyleneether) glycol;
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- d) recycling at least a portion of the OCE stream of step c) to the polymerization step a) such that the feed comprises from about 3 to about 15 wt % OCE.
A process for the single pass preparation of copolyether glycols by polymerizing feed comprising tetrahydrofuran and at least one alkylene oxide in the presence of an acid catalyst and at least one compound containing reactive hydrogen atoms, which comprises removing at least a portion of the dimer of the alkylene oxide formed and separating and recycling to the polymerization at least a portion of the OCE formed such that the feed comprises from about 3 to about 15 wt % OCE, said process exhibiting an STY of greater than about 0.9 g polyol/g cat.hr.
Dependencies are inferred from the claim text.