POLYETHER POLYMERIZATION PROCESS

Abstract

Alkylene oxides are polymerized in the presence of a catalyst system that includes a double metal cyanide catalyst. At least one additive is present. The additive is an alkali metal, ammonium or quaternary ammonium salt of a monocarboxylic acid having up to 24 carbon atoms; monobasic potassium phosphate, a monobasic ammonium or quaternary ammonium phosphate, a dibasic ammonium and quaternary ammonium phosphate or phosphoric acid.

Claims

1. A method for producing a polyether, the method comprising: I. forming a reaction mixture comprising a) a hydroxyl-containing starter, b) at least one alkylene oxide, c) a water insoluble polymerization catalyst complex that includes at least one double metal cyanide compound and d) an additive selected from the group consisting of alkali metal, ammonium and quaternary ammonium salts of monocarboxylic acids having up to 24 carbon atoms; monobasic alkali metal phosphates, dibasic sodium phosphate, monobasic ammonium phosphate, monobasic quaternary ammonium phosphates, tartaric acid, malic acid and succinic acid, and II. polymerizing the alkylene oxide onto the hydroxyl-containing starter in the presence of the water insoluble polymerization catalyst complex and the additive to produce the polyether.

2. The method of claim 1 wherein the double metal cyanide compound is represented by the formula:
M.sup.1.sub.b[M.sup.2(CN).sub.r(X.sup.1).sub.t].sub.c[M.sup.3(X.sup.2).sub.6].sub.d.Math.nM.sup.4.sub.xA.sup.1.sub.y(I) wherein: M.sup.1 and M.sup.4 each represent a metal ion independently selected from Zn.sup.2+, Fe.sup.2+, Co.sup.+2+, Ni.sup.2+, Mo.sup.4+, Mo.sup.6+, Al.sup.+3+, V.sup.4+, V.sup.5+, Sr.sup.2+, W.sup.4+, W.sup.6+, Mn.sup.2+, Sn.sup.2+, Sn.sup.4+, Pb.sup.2+, Cu.sup.2+, La.sup.3+, and Cr.sup.3+; M.sup.2 and M.sup.3 each represent a metal ion independently selected from Fe.sup.3+, Fe.sup.2+, Co.sup.3+, Co.sup.2+, Cr.sup.2+, Cr.sup.3+, Mn.sup.2+, Mn.sup.3+, Ir.sup.3+, Ni.sup.2+, Rh.sup.3+, Ru.sup.2+, V.sup.4+, V.sup.5+, Ni.sup.2+, Pd.sup.2+, and Pt.sup.2+; X.sup.1 represents a group other than cyanide that coordinates with the M.sup.2 ion; X.sup.2 represents a group other than cyanide that coordinates with the M.sup.3 ion; A.sup.1 represents a halide, nitrate, sulfate, carbonate, cyanide, oxalate, thiocyanate, isocyanate, perchlorate, isothiocyanate, an alkanesulfonate, an arylenesulfonate, trifluoromethanesulfonate, or a C.sub.1-4 carboxylate; b, c and d are each numbers that reflect an electrostatically neutral complex, provided that b and c each are greater than zero; x and y are integers that balance the charges in the metal salt M.sup.4.sub.xA.sup.1.sub.y; r is an integer from 4 to 6; t is an integer from 0 to 2; and n is a number from 0 and 20.

3. The process of claim 1 wherein the reaction mixture further comprises, as a separate component from the water insoluble polymerization catalyst complex, e), at least one M.sup.5 metal or semi-metal compound, in which the M.sup.5 metal or semi-metal is selected from magnesium or a metal or semi-metal M.sup.5 that falls within any of Groups 3 through 15, inclusive, of the 2010 IUPAC periodic table of the elements and the M.sup.5 metal or semi-metal is bonded to at least one alkoxide, aryloxy, carboxylate, acyl, pyrophosphate, phosphate, thiophosphate, dithiophosphate, phosphate ester, thiophosphate ester, amide, oxide, siloxide, hydride, carbamate, halide or hydrocarbon anion.

4. The method of claim 3 wherein component e) is present in an amount that provides 0.0025 to 50 moles of M.sup.5 metal per combined moles of M.sup.2 and M.sup.3 metal provided by the double metal cyanide catalyst.

5. The method of claim 3 wherein the M.sup.5 metal or semi-metal is selected from the group consisting of aluminum, gallium and hafnium.

6. The method of claim 1 wherein the additive is present in an amount of 1 to 10 times that of the catalyst complex, by weight.

7. The method of claim 1 wherein the additive is one or more compounds selected from the group consisting of alkali metal carboxylates, NH.sub.4H.sub.2PO.sub.4, monobasic alkali metal phosphates and Na.sub.2HPO.sub.4.

8. The method of claim 1 wherein the alkylene oxide is ethylene oxide.

9. The method of claim 1 which is semi-batch process comprising steps of charging the catalyst complex and starter to a reaction vessel, activating the catalyst complex and thereafter adding at least a portion of the alkylene oxide to the reaction vessel containing the activated catalyst complex and starter under polymerization conditions without removal of product until all of the alkylene oxide has been added, or a continuous process comprising steps of continuously feeding the catalyst complex, starter and alkylene oxide to a reaction vessel under polymerization conditions and continuously removing product from the reaction vessel.

10. The method of claim 1 wherein the reaction mixture has a hydroxyl content of 4.25 to 15 wt. %, based on the total weight of the reaction mixture, during at least a portion of step II.

Description

EXAMPLES 1-12 AND COMPARATIVE SAMPLES A-F

[0097] Ethylene oxide polymerizations are performed using a 48-well Symyx Technologies Parallel Pressure Reactor (PPR). Each of the wells is equipped with an individually weighed glass insert having an internal working liquid volume of approximately 5 mL. 3 mL of a mixture of 98.5% of a 625 weight average molecular weight poly(ethylene oxide) triol and 1.5% glycerol is added to each well, together with 265 parts per million by weight (ppm, based on the expected mass of the product) of a zinc hexacyanocobaltate catalyst complex (Arcol 3 Catalyst from Covestro), 265 ppm of aluminum oxide (Catalox BA, from Sasol North America) and 1335 ppm of an additive as indicated in Table 1. The wells are pressurized with 70 psig (483 kPa) dry nitrogen at 160 C. 0.3 mL of ethylene oxide is injected into each well, raising the internal pressure in each well to 140-160 psig (966-1103 kPa). The internal pressure is monitored over time as an indication of the progress of the ethylene oxide polymerization reaction. The times required for the pressure to decline to 90 psig (621 kPa) and then to 80 psig (552 kPa) are recorded. Shorter times are indicative of greater catalytic activity. Results are as indicated in Table 1.

TABLE-US-00001 TABLE 1 Time to Time to 90 psig 80 psig (621 kPa), (552 kPa), Designation Additive/ min. min. A* None >180 >180 1 Na Acetate 3.5 5.7 2 K Acetate 3.8 5.9 3 Cs Acetate 5.4 9.0 4 Na Formate 8.3 14.4 5 K Benzoate 6.8 12.25 6 Na Laurate 14.7 26.05 7 Monobasic 4.4 8 Potassium Phosphate 8 NH.sub.4H.sub.2PO.sub.4 4.9 7.3 9 LiH.sub.2PO.sub.4 8.0 12.5 10 Na.sub.2HPO.sub.4 8.0 12.5 11 Tartaric acid 15.9 37.5 12* Na Stearate 20.1 35.0 B* Na Triflate 40.8 64.4 C* K.sub.2HPO.sub.4 117. 7 136.4 D* NaHCO.sub.3 84.4 126.8 E* Na.sub.2CO.sub.3 74.1 116.9 F* Ca Formate 98.2 >180 *Not an example of the invention.

[0098] Comparative Sample A represents a baseline case. The catalyst complex by itself is unable to initiate polymerization under these very stringent conditions (high concentration of hydroxyl groups plus the selection of ethylene oxide). Examples 1-12 show that active polymerization takes place when alkali metal carboxylates (Ex. 1-6 and 12), monobasic potassium phosphate, ammonium dihydrogen phosphate or lithium dihydrogen phosphate (Ex. 7-9), tartaric acid (Ex. 11) or dibasic sodium phosphate (Ex. 12) are additionally present in the reaction mixture. The time for the reactor pressure to decline to 90 psig (621 kPa) is reduced by a factor of 9 or greater in each instance.

[0099] Comparative Samples BF show the poorer effect of various other additives. The triflate salt (Comp. B) provides some benefit, but is much less effective than the additives of the invention. The dibasic potassium phosphate, carbonate salts and the alkaline earth carboxylate salt (Comp. C, D, E and F) provide almost no benefit.

EXAMPLES 13-23 AND COMPARATIVE SAMPLES G-K

[0100] Ethylene oxide polymerizations are performed in the same manner as in the previous set of examples, replacing aluminum oxide with an equivalent concentration of aluminum tri(sec-butoxide). The additive and results are as indicated in Table 2.

TABLE-US-00002 TABLE 2 Time to Time to 90 psig 80 psig (621 kPa), (552 kPa), Designation Additive/ min. min. A* None >180 >180 13 Na Acetate 4.4 6.55 14 K Acetate Not Done 1.8 15 Cs Acetate 5.0 8.1 16 Na Formate 6.15 9.6 17 K Benzoate 9.2 16.4 18 Na Laurate 14.2 26.6 19 KH.sub.2PO.sub.4 13.0 20.1 20 NH.sub.4H.sub.2PO.sub.4 8.5 180 21 Na Stearate 19.8 35.0 22 Tartaric Acid 6.3 13.3 23 Na.sub.2HPO.sub.4 4.2 8.3 G* Na Triflate 46.0 78.7 H* K.sub.2HPO.sub.4 106.9 134.5 I* NaHCO.sub.3 86.8 125.4 J* Na.sub.2CO.sub.3 159.7 >180 K* LiH.sub.2PO.sub.4 86.6 >180 *Not an example of the invention.

[0101] The alkali metal carboxylates (Ex. 13-18 and 21), the monobasic phosphates (Examples 19 and 20), tartaric acid and disodium hydrogen phosphate (Ex. 22, 23) all dramatically increase the polymerization rate. The triflate salts, K.sub.2HPO.sub.4, the carbonate salts and LiH.sub.2PO.sub.4 provide little if any beneficial effect.