Process for preparing polyoxyalkylene glycol ethers using block polymers as demulsifiers

1 . A process for preparing a polyoxyalkylene glycol monoether or a diether or a mixture thereof, said process comprising reacting a mixture comprising an alkoxide and an alkylating agent, said reacting comprising adding to said mixture water and a block polymer which is obtained from a compound which comprises from 1 to 30 carbon atoms and from 1 to 25 hydroxyl groups, amino groups or both by its blockwise alkoxylation with at least 2 different blocks of in each case from 1 to 200 mol of C 2 - to C 4 -alkylene oxide.

2 . The process as claimed in claim 1 , in which the polyoxyalkylene glycol monoether or diether or mixture thereof corresponds to formula 2

R—O-(AO) y —R 1   (2)

in which

R is hydrogen, a hydrocarbon group having from 1 to 24 carbon atoms or an R*—C(O)— group where R* is a hydrocarbon group having from 1 to 24 carbon atoms,

R 1 is a hydrocarbon group having from 1 to 12 carbon atoms,

AO is an alkoxy group, and

y is from 1 to 200.

3 . The process as claimed in claim 2 , in which y is from 2 to 100.

4 . The process of claim 2 in which R is a group selected from the group consisting of an alkyl group having from 1 to 24 carbon atoms, an alkenyl group having from 2 to 24 carbon atoms, a group of the formula R*—C(O)— where R* is a hydrocarbon group having from 1 to 24 carbon atoms,

a phenyl group, a benzyl group, an allyl group and mixtures thereof.

5 . The process of claim 2 , in which R comprises from 4 to 12 carbon atoms.

6 . The process of claim 2 , in which R 1 is selected from the group consisting of an alkyl having from 1 to 12 carbon atoms, an alkenyl having from 2 to 12 carbon atoms, a phenyl, a benzyl, an allyl and mixtures thereof.

7 . The process of claim 2 , in which R 1 comprises from 2 to 8 carbon atoms.

8 . The process of claim 2 , in which AO comprises at least one propoxy or butoxy group.

9 . The process of claim 1 , in which the block polymer corresponds to the formula 3

in which

A, B are various C 2 - to C 4 -alkylene groups

R 3 is H or a hydrocarbon radical which has from 1 to 30 carbon atoms and optionally comprises a heteroatom

R 4 is H or a C 1 - to C 4 -alkyl group

I, m are each independently from 1 to 200

n is from 0 to 200,

q is from 1 to 25, and

Y is O or NR 5 , and

R 5 is as defined for R 3 .

10 . The process as claimed in claim 9 , in which Y is NR 5 , the compound of the formula (3) has at least two active hydrogen atoms, and in which q is equal to 2 or greater than 2.

11 . The process as claimed in claim 9 , in which R 3 bears alkoxy groups of the formula -(A-O) I —(B—O) m -(A-O) n —.

12 . The process of claim 9 , in which q is from 2 to 20.

13 . The process of claim 1 , in which the block polymer is crosslinked to provide a crosslinked block polymer.

14 . The process as claimed in claim 13 , in which the crosslinked block polymer is used in alkoxylated form, wherein the alkoxylation is performed with from 5 to 700 g of a C 2 - to C 4 -alkylene oxide per 100 g of crosslinked block polymer.

15 . The process of claim 1 , wherein the mixture further comprises a codemulsifier selected from the group consisting of

a) an alkoxylated alkylphenol-aldehyde resin

b) an alkoxylated polyethyleneimine, and a mixture thereof.

16 . The process of claim 13 , wherein the crosslinked block polymer is crosslinked by the reaction of the block polymer with an compound selected from the group consisting of a bi-glycidyl ether, a tri-glycidyl ether, a tetraglycidyl ether and mixtures thereof; or by esterification with a polybasic dicarboxylic acid or an anhydride of the dicarboxylic acid, or a mixture thereof; or by reaction with a polyvalent isocyanate.

17 . The process of claim 14 , wherein the alkoxylation is performed with from 30 to 300 g per 100 g of the crosslinked block polymer.