Environmentally friendly water/oil emulsions

1. A demulsifier for water/oil emulsions, said demulsifier comprising at least one orthoester based polymer having the general formula

wherein R1 is hydrogen or a hydrocarbyl group with 1-4 carbon atoms, R2, R3, and R4 are, independently, a group comprising C 3 -C 4 alkyleneoxy groups and/or ethyleneoxy groups in any order, and an end group Y, which is, independently, hydrogen, or a hydrocarbyl group with 1-30 carbon atoms, provided that at least one of the groups R2, R3, and R4 comprises at least one block of at least on average 4 alkyleneoxy groups with 3 and/or 4 carbon atoms, and provided that if Y is hydrogen, then at least one ethyleneoxy or alkyleneoxy group is connected to Y; or a di- or polycondensate of the polymer via free hydroxyl groups in R2, R3 or R4, wherein the polymer has an average molecular weight of from 1,500 to 40,000.

2. The demulsifier of claim 1 wherein R1 is hydrogen or a hydrocarbyl group with 1-4 carbon atoms, R2, R3, and R4 are, independently, a group -(A)n(CH 2 CH 2 O) m Y or —(CH 2 CH 2 O)m(A)nY, wherein each A is, independently, an alkyleneoxy group with 3-4 carbon atoms, n and m are, on average and independently, a number of 0-100, provided that at least one of the groups R2, R3, and R4 comprises at least one block of at least on average 4 alkyleneoxy groups with 3 and/or 4 carbon atoms, and each Y is, independently,

hydrogen, a hydrocarbyl group with 1-30 carbon atoms, provided that if Y is hydrogen, then at least one of n and m is a number of 1-100, or a di- or polycondensate of the polymer via free hydroxyl groups in R2, R3 or R4.

3. The demulsifier of claim 2 , characterized in that the sum of all n in the polymer is 10-1200 and at least one of the groups R2, R3, and R4 comprises at least one block with 6-20 alkyleneoxy groups with 3-4 carbon atoms.

4. The demulsifier of claim 1 , characterized in that Y is, independently, H or a hydrocarbyl group with 1-4 carbon atoms.

5. The demulsifier of claim 1 , characterized in that the amount of ethyleneoxy groups in the polymer is 40-85% of the total molecular weight.

6. The demulsifier of claim 1 , characterized in that R1 is hydrogen, A is an alkyleneoxy group with 3 carbon atoms, and Y is hydrogen, and where the amount of ethyleneoxy groups is 50-75% by weight of the total molecular weight, the molecular weight span is 1,000400,000, and the average molecular weight is 2,000-30,000.

7. The demulsifier of claim 1 , characterized in that the water/oil emulsions result from a process for the production of oil.

8. The demulsifier of claim 1 , characterized in that the water/oil emulsions result from a fermentation process.

9. A process for demulsification of a water-in-oil emulsion, said process comprising adding orthoester polymer as defined in claim 1 to said water-in-oil emulsion.

10. An orthoester based polymer having the formula

wherein R1 is hydrogen or a hydrocarbyl group with 1-4 carbon atoms, R2 is a group comprising C 3 -C 4 alkyleneoxy groups and/or ethyleneoxy groups in any order, and an end group Y, which is H or a hydrocarbyl group with 1-4 carbon atoms, R4 is a group -(A) o (CH 2 CH 2 O)pZ or —(CH 2 CH 2 O)p(A) o Z, wherein Z is a hydrocarbyl group with 5-30 carbon atoms, each A is, independently, an alkyleneoxy group with 3-4 carbon atoms, o is a number 0-100, and p is on average a number of at least 1 and of at most 100, and R3 is selected from the group R2, R4, and a hydrocarbyl group with 1-4 carbon atoms, and provided that at least one of the groups R2, R3, and R4 comprises at least one block of at least 4 alkyleneoxy groups with 3 and/or 4 carbon atoms, or a di- or polycondensate of the polymer via free hydroxyl groups in R2 or R3, wherein the polymer has an average molecular weight of from 1,500 to 40,000.

11. A method for producing a polymer or polymer mixture as defined in claim 10 , characterized in that the polymer or polymer mixture is produced in one or several steps by reacting an orthoester having the general formula

wherein R1 has the same meaning as in claim 1 and R8 is a hydrocarbyl group with 1 to 4 carbon atoms, with reactants comprising C 3 -C 4 alkyleneoxy groups and/or ethyleneoxy groups in any order, an end group Y, which is H or a hydrocarbyl group with 1-4 carbon atoms, and one hydroxyl group at the other end of the molecule, HO(A) o (CH 2 CH 2 O) p Z, HO(CH 2 CH 2 O)p(A)OZ, wherein A, o, p, and Z have the same meaning as in claim 10 , under removal of liberated hydroxyl-containing compounds of the formula R8OH.

12. A method for producing a polymer or polymer mixture as defined in claim 2 , characterized in that at least one of the groups Y is H and n and m in the same substituent as said Y are a number of 1-100, wherein the polymer or polymer mixture is produced in one or several steps by reacting an orthoester having the general formula

wherein R8 is a hydrocarbyl group with 1-4 carbon atoms, with a reactant having the formula HO(A) n Y, wherein Y is H and n is 1-100, under removal of liberated hydroxyl-containing compounds of the formula R8OH, and then reacting the obtained intermediate with Ern moles of ethylene oxide in the presence of an alkaline catalyst, or reacting an orthoester of formula (II) with a reactant having the formula HO(CH 2 CH 2 O) m Y, wherein Y is H and m is 1-100, under removal of liberated hydroxyl-containing compounds of the formula R8OH, and then reacting the obtained intermediate with Σn moles of an alkylene oxide having 3-4 carbon atoms in the presence of an alkaline catalyst.

13. A method according to claim 11 wherein the alkaline catalyst is an alkali hydroxide or an alkali metal alkoxide, preferably NaOH, KOH, NAOCH 3 and/or KOCH 3 .

14. The demulsifier of claim 1 wherein the polymer has an average molecular weight of from 2,000 to 30,000.

15. The orthoester-based polymer of claim 10 wherein the polymer has an average molecular weight of from 2,000 to 30,000.

16. The process for demulsification of a water-in-oil emulsion of claim 9 wherein the polymer has an average molecular weight of from 2,000 to 30,000.