Polymeric compositions and methods of using them

• US 4,670,501 A
• Filed: 05/16/1985
• Issued: 06/02/1987
• Est. Priority Date: 05/16/1984
• Status: Expired due to Term

• Current Assignee: CIBA Specialty Chemicals Water Treatments Limited (BASF SE)
• Original Assignee: Allied Colloids Limited (BASF SE)
• Inventors: Dymond, Brian, Langley, John, Hawe, Malcolm
• Primary Examiner(s): Michl, Paul R.
• Application Number:
  US06/734,776
• Time in Patent Office: 747 Days
• Field of Search: 524/458, 524/460, 524/801
• US Class Current: 524/458
• CPC Class Codes: C09K 3/00 Materials not provided for elsewhere
• CPC Class Codes: C09K 8/32 Non-aqueous well-drilling compositions, e.g. oil-based
• CPC Class Codes: C09K 8/36 Water-in-oil emulsions
• CPC Class Codes: Y10S 524/923 Treating or preparing a nonaqueous dispersion or emulsion of a solid polymer or specified intermediate condensation product

Abstract

Water-immiscible liquids, for example oil-based drilling fluids, are thickened by the addition of an aqueous dispersion of polymeric particles that are water-insoluble, and insoluble but swellable polymer, in the water immiscible liquid. The particles have a unswollen average diameter of less than 10 μm and at least 30% by weight are preferably in the range 0.5 to 5 μm. Preferred polymers are formed from more than 80% by weight hydrophobic monomers, preferably alkyl (meth) acrylates, and up to 20% hydrophilic monomers, preferably unsaturated carboxylic acids, preferably acrylic acid.

Claims

1. A water-immiscible liquid thickened by water insoluble polymer particles having a dry weight average particle size of below 10 μ

m and that are insoluble in the water-immiscible liquid but are swollen by the liquid and that comprise a polymer which has a glass transition temperature of less than about 25°

C. and formed from monomers of which 80-100% are hydrophobic and 0-20% are hydrophilic, in which at least 25% of the monomers are both polar and hydrophobic and in which not more than 30% of the monomers are hydrophobic aromatic hydrocarbon monomers, all percentages being by weight of total monomer.

2. A liquid according to claim 1 in which the particles are swollen to 4 to 50 times their dry volume.

3. A liquid according to claim 1 in which at least 30% by weight of the particles have an unswollen size of 0.05 to 5 μ

m.

4. A liquid according to claim 1 in which the polymer is formed from 80 to 100% C_1-30 alkyl (meth) acrylate monomers of which 50% to 100% are C_6-18 alkyl (meth) acrylate monomers, and 0 to 20%, by weight hydrophilic monomers.

5. A liquid according to claim 1 in which the polymer is formed from 90 to 100% alkyl (meth) acrylate of which at least 50% by weight is C_6-10 alkyl (meth) acrylate, and 0.5 to 10%, by weight water soluble monomer.

6. A liquid according to claim 1 in which the particles are formed of a copolymer of ethylenically unsaturated monomers and have an external hydrophilic shell formed of a monomer that is hydrophilic but that is miscible with the other monomer or monomers in the copolymer.

7. A liquid according to claim 1 in which the polymer is formed from monomers that include 0.1 to 5% of a hydrophilic monomer selected from unsaturated carboxylic acids, acrylamide, dialkylaminoalkyl (meth) acrylates and hydroxyalkyl (meth) acrylates.

8. A liquid according to claim 1 in which the polymer is substantially uncross-linked.

9. A liquid according to claim 1 in which the polymer has a glass transition temperature of less than -20°

C.

10. A liquid according to claim 1 in which the polymer is film forming at 20°

C.

11. A liquid according to claim 1 in which the polymer particles have been formed by emulsion polymerisation.

12. A liquid according to claim 1 in which the polymer particles have been made by emulsion polymerisation and the liquid has been formed by adding to the water-immiscible liquid the resultant aqueous emulsion of the polymer particles.

13. A liquid according to claim 1 and that is a downhole fluid that is a water-in-oil emulsion.

14. A liquid according to claim 1 in which at least 50% of the monomers are both polar and hydrophobic.

15. A liquid according to claim 14 in which at least 80% of the monomers are both polar and hydrophobic.

16. A liquid according to claim 1 that is the continuous phase of a dispersion of polymer particles.

17. A liquid according to claim 1 in which the polar and hydrophobic monomers are ethylenically unsaturated monomers carrying a carboxylic ester group or amine group substituent and that have a solubility of below 3% by weight in water at 20°

C.

18. A liquid according to claim 1 in which the hydrophobic monomers are selected from ethylene and polar hydrophobic monomers which are ethylenically unsaturated monomers carrying a carboxylic ester group or amide group substituent and that have a solubility of below 3% by weight in water at 20°

C.

19. A liquid according to claim 1 in which the hydrophilic monomers are selected from dialkyl amino alkyl (meth) acrylate and their quaternary addition and acid salts, acrylamide, N-(dialkyl amino alkyl) acrylamide and meth acrylamide and their quaternary addition and acid salts, hydroxy alkyl (meth) acrylates and unsaturated sulphonic or carboxylic acids and their alkyl amino salts.

20. A liquid according to claim 1 in which the polymer is formed from 40-100% 2-ethyl hexyl acrylate, 0-10% hydrophilic groups and 0-50% C_6-30 alkyl (meth) acrylates.

21. A liquid according to claim 1 in which the polymer is formed from 40-100% 2-ethyl hexyl acrylate, 0-10% hydrophilic groups and 0-50% C_12-18 alkyl (meth) acrylates.

22. A liquid according to claim 1 in which the monomers include 0.3-3% acrylic acid.

23. A liquid according to claim 5 in which the C_6-10 alkyl (meth) acrylate is 2-ethyl hexyl acrylate.

24. A liquid according to claim 7 in which the unsaturated carboxylic is acrylic acid.

25. A liquid according to claim 12 in which the emulsion polymerisation was conducted in the presence of a nonionic oil-in-water emulsifier.

26. A liquid according to claim 12 in which water has been removed from around the said water insoluble polymer particles after addition of the aqueous emulsion to the water-immiscible liquid.

27. A liquid according to claim 1 in which the liquid has been formed by adding to the water-immiscible liquid an emulsion of the polymer particles.

28. A water-immiscible liquid thickened by water insoluble polymer particles having a dry weight average particle size of below 10 μ

m and that are insoluble in the water-immiscible liquid but are swollen to 4 to 50 times their dry volume by the liquid, and that comprises a polymer which has a glass transition temperature of less than about 25°

C., said polymer particles having been made by emulsion polymerisation of from 80 to 100% C_1-30 alkyl (meth)acrylate monomers of which 50 to 100% are hydrophobic C_6-18 alkyl (meth)acrylate monomers and 0 to 20% are hydrophilic monomers, in which at least 25% of the monomers are both polar and hydrophobic, and in which not more than 30% of the monomers are hydrophobic aromatic hydrocarbon monomers, all percentages being by weight of total monomer, and said liquid having been formed by adding to the water-immiscible liquid the resultant aqueous emulsion of the polymer particles.