Encapsulation of hydrophilic additives

Patent metadata

Field	Value
Publication number	US-2017283684-A1
Application number	US-201515511801-A
Country	US
Kind code	A1
Filing date	Sep 25, 2015
Priority date	Sep 26, 2014
Publication date	Oct 5, 2017
Grant date	—

Abstract

The instant invention relates to a process for the encapsulation of a non-amine hydrophilic compound C, comprising the steps of: (E1) providing a reverse emulsion containing: an oil phase (O), comprising a curable mixture of isocyanate and polyalkyldiene hydroxylated or polyol dispersed in said oil phase, drops of an aqueous phase W 1 , containing: said non-amine hydrophilic compound C; and at least 5% by weight of a compound C carrying more than 2 amine groups; (E2) pouring the reverse emulsion of step (E1) in a second water phase W 2 to make a multiple emulsion water/oil/water; and, then, (E3) curing into polyurethane all or part of the curable mixture contained in the oil phase.

First claim

1 . A process for the encapsulation of a non-amine hydrophilic compound C, the process comprising the steps of:
(E1) providing a reverse emulsion containing:
an oil phase (O), comprising a curable mixture of
isocyanate; and
polyalkyldiene hydroxylated or polyol

dispersed in said oil phase, drops of a water solution or dispersion (aqueous phase W 1 ), containing:
said non-amine hydrophilic compound; and
at least 5% by weight, based on the total weight of the phase W 1 , of a compound C′ carrying more than 2 amine groups;

(E2) pouring the reverse emulsion of step (E1) in a second water phase W 2 to make a multiple emulsion water/oil/water, containing, as the internal water phase, drops including the non-amine hydrophilic compound C; and, then, (E3) curing into polyurethane all or part of the curable mixture contained in the oil phase, whereby a formulation is obtained, containing, dispersed in the phase W 2 particles of polyurethane encapsulating an aqueous internal phase including the non-amine hydrophilic compound C.

2 . The process of claim 1 , wherein the oil phase (O) has a viscosity lower than the viscosity of phase (W 1 ) in the conditions of steps (E1) and (E2).

3 . The process of claim 1 , wherein the water phase (W 1 ) includes fatty acid esters.

4 . The process of claim 1 , wherein the water phase (W 2 ) contains a mineral salt.

5 . The process of claim 1 , wherein the water phase (W 2 ) contains a protective colloid and rheological agent.

6 . The process of claim 1 , wherein the compound C′ includes at least one polyethyleneimine.

7 . The process of claim 1 , wherein the compound C is a boric acid or another crosslinker of the guar.

8 . The process of claim 1 , wherein compound C is a dispersing agent or a clay inhibitor.

9 . A formulation obtained according to the process of claim 1 , comprising drops of a water phase including non-amine hydrophilic compound encapsulated in particles of polyurethane, said particles being dispersed in a water phase.

10 . A method for allowing a targeted release of a compound C just at the drill bit by drilling with the formulation of claim 9 .

11 . The process of claim 1 , wherein the non-amine hydrophilic compound C, does not contain any amine group.

12 . The process of claim 3 , wherein the fatty acid esters are esters of rapeseed oil.

13 . The process of claim 4 , wherein the mineral salt is NaCl.

14 . The process of claim 5 , wherein the protective colloid and rheological agent is xanthan gum.

15 . A method for allowing a targeted release of a compound C, wherein capsules comprising the formulation of claim 9 are sheared entering the fractures and as fractures are closing at the end of a fracturing operation.

Assignees

• Rhodia Operations

Inventors

• Cadix Arnaud

Classifications

• C08G18/792

  formed by oligomerisation of aliphatic and/or cycloaliphatic isocyanates or isothiocyanates · CPC title

• C08G18/698

  Mixtures with compounds of group C08G18/40 · CPC title

• C09K8/514

  of natural origin, e.g. polysaccharides, cellulose (C09K8/512 takes precedence) · CPC title

• C08G18/6423

  Polyalkylene polyamines; polyethylenimines; Derivatives thereof (polyamides or polyesteramides C08G18/60) · CPC title

• E21B33/138

  Plastering the borehole wall; Injecting into the formation · CPC title