Defoaming compositions comprising hydroxy terminated siloxanes and methods of making and using the same

Patent metadata

Field	Value
Publication number	US-9669332-B2
Application number	US-201514982024-A
Country	US
Kind code	B2
Filing date	Dec 29, 2015
Priority date	Dec 30, 2014
Publication date	Jun 6, 2017
Grant date	Jun 6, 2017

Abstract

Disclosed herein are methods of defoaming industrial process streams, the methods comprising adding to the industrial process stream an emulsion comprising silicone emulsion droplets in a continuous aqueous phase. Also disclosed herein are defoamer compositions comprising these silicone emulsions and methods of making such compositions.

First claim

What is claimed is:

1. A method of making a defoamer composition comprising silicone droplets emulsified in an aqueous phase, the method comprising:
a) providing a silicone phase comprising a filled silicone made by:
i) providing from about 75 weight parts to about 90 weight parts of a linear hydroxyl terminated siloxane having a neat viscosity at 25° C. of from about 10 cst to about 3000 cst; and
ii) dispersing from about 10 weight parts to about 25 weight parts of silica in said siloxane to make a filled silicone;

b) mixing said filled silicone (“FS”) with a high viscosity dimethylsiloxane (“HVD”) having a viscosity at 25° C. of from about 10,000 cst to about 100,000 cst at a weight ratio (HVD:FS) of from about 50:1 to about 5:1, preferably from about 30:1 to about 10:1,
c) providing an aqueous phase; and
d) emulsifying said silicone phase in said aqueous phase to form a silicone droplets in water emulsion.

2. The method of claim 1 , wherein said dispersion step (ii) further comprises heating said siloxane to a temperature of from 90° C. to 160° C., and homogenizing said silica in said siloxane.

3. The method of claim 2 , wherein said temperature is adequate to facilitate said dispersion of said silica in said siloxane, and to treat any exposed hydrophilic groups on said silica.

4. The method of claim 1 , further comprising mixing one or more ingredients selected from a surfactant, a salt, and a biocide into said aqueous phase or said emulsion.

5. A method of defoaming or preventing foam in an industrial process stream comprising a step of adding to said industrial process stream an emulsion comprising silicone droplets in an aqueous phase, wherein:
a) said silicone droplets comprise filled silicone comprising a silica in silanol dispersion,
b) said filled silicone comprises silica to silanol at a weight ratio of from about 10:90 to about 25:75,
c) said silanol is a linear hydroxyl terminated siloxane having a neat viscosity at 25° C. of from about 10 cst to about 3000 cst at 25° C.; and
d) said silicone droplets further comprise a high viscosity dimethylsiloxane having a viscosity at 25° C. of from about 10,000 to about 100,000 cst, wherein said filled silicone (“FS”) and said high viscosity dimethylsiloxane (“HVD”) are present in said emulsion at a weight ratio (HVD:FS) of from about 50:1 to about 5:1.

6. The method of claim 5 , wherein said filled silicone has a neat viscosity of from about 750 cP to about 5,000 cP at 25° C.

7. The method of claim 5 , wherein said silanol has a neat viscosity at 25° C. of from about 75 to about 3000 cst.

8. The method of claim 5 , wherein said emulsion comprises from about 0.5 to about 10 weight percent of said filled silicone.

9. The method of claim 5 , wherein said emulsion further comprises one or more ingredients selected from a drainage agent, a surfactant, a salt, and a biocide.

10. The method of claim 5 , wherein said silica in said filled silicone is a hydrophobic silica having a median particle size of from about 30 to about 1 microns.

11. The method of claim 5 , wherein said industrial process stream is a stream in a process for manufacturing pulp, paper, cement, or textiles.

12. A defoamer composition comprising silicone droplets emulsified in an aqueous phase, wherein:
a) said silicone droplets comprise a filled silicone;
b) said filled silicone includes from about 75 weight parts to about 90 weight parts of a silanol and from about 10 weight parts to about 25 weight parts of silica dispersed in said silanol,
c) said silanol is a linear hydroxyl terminated siloxane having a neat viscosity at 25° C. of from about 10 cst to about 3000 cst; and
d) said silicone droplets further comprise a high viscosity dimethylsiloxane having a viscosity at 25° C. of from about 10,000 to about 100,000 cst, wherein said filled silicone (“FS”) and said high viscosity dimethylsiloxane (“HVD”) are present in said emulsion at a weight ratio (HVD:FS) of from about 50:1 to about 5:1.

13. The defoamer composition of claim 12 , wherein said silica in said filled silicone is a hydrophobic silica having a median particle size of from about 30 to about 1 microns.

14. The defoamer composition of claim 12 , further comprising one or more ingredients selected from a surfactant, a salt, and a biocide.

Assignees

• Kemira Oyj

Inventors

• Wilson Robert
• Bava Luciana
• Kirwan Carter

Classifications

• D21C3/28

  Prevention of foam · CPC title

• B01D19/0404

  characterised by the nature of the chemical substance · CPC title

• B01D19/0409 Primary

  compounds containing Si-atoms · CPC title

• D21H21/12

  Defoamers · CPC title