Process for the preparation of water-in-oil and oil-in-water nanoemulsions

Patent metadata

Field	Value
Publication number	US-9884299-B2
Application number	US-201313845515-A
Country	US
Kind code	B2
Filing date	Mar 18, 2013
Priority date	Mar 31, 2006
Publication date	Feb 6, 2018
Grant date	Feb 6, 2018

Abstract

Process for the preparation of a water-in-oil or oil-in-water nanoemulsion wherein the dispersed phase is distributed in the dispersing phase in the form of droplets having a diameter ranging from 1 to 500 nm, comprising:
1) the preparation of a homogeneous water/oil blend (I) characterized by an interface tension lower than 1 mN/m, comprising water in an amount of 30 to 70% by weight, at least two surface-active agents having a different HLB, selected from non-ionic, anionic, polymeric surface-active agents, said surface-active agents being present in such a quantity as to make the blend homogeneous; 2) the dilution of the blend (I) in a dispersing phase consisting of oil or water with the addition of a surface-active agent, selected from non-ionic, anionic, polymeric surface-active agents, the quantity of the dispersing phase and surface-active agent being such as to obtain a nanoemulsion having a HLB different from that of the blend (I).

First claim

The invention claimed is:

1. A low energy process for the preparation of an oil-in-water nanoemulsion wherein a dispersed phase is distributed in a dispersing phase in the form of droplets having a diameter ranging from 1 to 500 nm, said process consisting of:
diluting a
homogeneous water/oil blend (I) having an interface tension lower than 1 mN/m and comprising water in an amount of 30 to 70% by weight and at least two surface-active agents having a different HLB, said surface-active agents being selected from the group consisting of non-ionic surface-active agents, anionic surface-active agents, and polymeric surface-active agents, and said surface-active agents being present in said water/oil blend (I) an amount of from 5 to 50% by weight

in a
dispersing phase consisting of water and a surface-active agent selected from the group consisting of a non-ionic surface-active agent, an anionic surface-active agent, and a polymeric surface-active agent, the quantity of the dispersing phase and the surface-active agent being sufficient to obtain an oil-in-water nanoemulsion having an HLB higher than that of said homogeneous water/oil blend (I),

wherein during dilution a spontaneous and instantaneous phase inversion occurs, together with the formation of the nanoemulsion.

2. The process according to claim 1 , wherein, in the homogeneous blend (I), the weight ratio between the surface-active agents produces a HLB value higher than 8.

3. The process according to claim 2 , wherein the surface-active agents are selected from non-ionic surface-active agents and the weight ratio between the surface-active agents produces a HLB ranging from 10 to 15.

4. The process according to claim 2 , wherein the surface-active agents are selected from anionic surface-active agents and the weight ratio between the surface-active agents produces a HLB higher than 20.

5. The process according to claim 2 , wherein the weight proportion between the concentration of surface-active agents in the blend and the quantity of water/oil to be dispersed varies from 0.07 to 3.5.

6. The process according to claim 5 , wherein the weight proportion between the concentration of surface-active agents in the blend and the quantity of water/oil to be dispersed varies from 0.1 to 2.

7. The process according to claim 1 , wherein the surface-active agents having a different HLB are selected from non-ionic and polymeric surface-active agents.

8. The process according to claim 1 , wherein the surface-active agents having a different HLB are selected from the group consisting of a first surface-active agent selected from non-ionic lipophilic surface-active agents (type A), a second surface-active agent selected from non-ionic hydrophilic surface-active agents (type B), and a third surface-active agent selected from polymeric surface-active agents (type C), the composition of surface-active agents (A)+(B)+(C) having a HLB ranging from 8 to 16.

9. The process according to claim 8 , wherein the composition of surface-active agents (A)+(B)+(C) has a HLB ranging from 10 to 15.

10. The process according to claim 1 , wherein the surface-active agents having a different HLB consist of a non-ionic lipophilic surface-active agent of the group of esters of fatty acids with a HLB lower than 11, a non-ionic hydrophilic surface-active agent of the group of alkyl glucosides with a HLB higher than 11 and a non-ionic polymeric surface-active agent with a HLB varying from 4 to 14.

11. The process according to claim 1 , wherein the oil-in-water nanoemulsion is prepared by dissolving a hydrophilic surface-active agent in water and slowly adding the homogeneous blend (I) under stirring, said hydrophilic surface-active agent being selected from the group consisting of non-ionic surface-active agents and polymeric surface-active agents.

12. The process according to claim 1 , wherein the diluting of the blend (I) is performed at a temperature ranging from 5° C. to 60° C.

13. The process according to claim 1 , wherein the quantity of dispersing phase and the surface-active agent is sufficient to obtain a nanoemulsion having an HLB 0.5 units higher with respect to that of homogeneous water/oil blend (I).

14. The process according to claim 13 , wherein:
homogeneous water/oil blend (I) comprises non-ionic and polymeric surface-active agents,
the dispersing phase consists of water and a non-ionic surface-active agent selected from the group consisting of alkyl glucosides, and
the quantity of dispersing phase and surface-active agent is sufficient to obtain a nanoemulsion having a HLB at least 0.8-5 units higher than homogeneous water/oil blend (I).

15. The process according to claim 1 , wherein the oil for the preparation of the oil-in-water nanoemulsion is selected from the group consisting of linear hydrocarbons, branched hydrocarbons, and complex hydrocarbon blends.

16. The process according to claim 15 . wherein the oil is selected from the group consisting of dodecane, diesel, kerosene, soltrol, and mineral spirits.

17. The process according to claim 1 , wherein the water for the preparation of the oil-in-water nanoemulsion is selected from the group consisting of demineralised water, saltwater, and water containing additives.

Assignees

• Del Gaudio Lucilla
• Lockhart Thomas Paul
• Belloni Alessandra
• Bortolo Rossella
• Tassinari Roberto
• Eni Spa
• Polimeri Europa Spa

Inventors

• Del Gaudio Lucilla
• Lockhart Thomas Paul
• Belloni Alessandra
• Bortolo Rossella
• Tassinari Roberto

Classifications

• C09K8/54

  Compositions for in situ inhibition of corrosion in boreholes or wells · CPC title

• C09K8/528

  inorganic depositions, e.g. sulfates or carbonates · CPC title

• C09K8/524

  organic depositions, e.g. paraffins or asphaltenes · CPC title

• C10L1/328

  Oil emulsions containing water or any other hydrophilic phase · CPC title

• A61K9/1075 Primary

  Microemulsions or submicron emulsions; Preconcentrates or solids thereof; Micelles, e.g. made of phospholipids or block copolymers (A61K9/0026 takes precedence) · CPC title