Defoaming formulations containing organopolysiloxanes

Patent metadata

Field	Value
Publication number	US-10870071-B2
Application number	US-201716330193-A
Country	US
Kind code	B2
Filing date	Jun 6, 2017
Priority date	Jun 6, 2017
Publication date	Dec 22, 2020
Grant date	Dec 22, 2020

Abstract

Defoamer compositions containing a plurality of defined organopolysiloxanes exhibit very short initial foam collapse and yet exhibit long lasting defoaming activity when added to aqueous media prone to foaming.

First claim

The invention claimed is:

1. A defoamer formulation, comprising:
(1) at least one organopolysiloxane containing per molecule at least one structural unit of formula
O 1/2 R 2 Si—Y-SiRO 2/2   (I)

at least 2 units of formula
R 1 R 2 SiO 1/2   (II)

and units of formula
R 2 SiO 2/2   (III),

wherein
R each is identical or different and is a monovalent SiC-bonded hydrocarbon radical having
1 to 30 carbon atoms which optionally contains one or more nonadjacent O-atoms and which is free from aliphatic carbon-carbon multiple bonds and
R 1 each is identical or different and is R or an alkenyl radical having 2 to 30 carbon atoms, wherein at least one alkenyl radical per molecule is present,
Y each is an identical or different divalent hydrocarbon radical having 2 to 30 carbon atoms,
with the proviso that the at least one organopolysiloxane contains a structural element of formula
R 2 Y 2 SiO—(SiR 2 O) x1 —SiRY 1 O—(SiR 2 O) x2 —SiR 2 R 1   (IV),

wherein
R and R 1 are as defined above,
Y 1 is a divalent hydrocarbon radical having 2 to 30 carbon atoms which is bonded to a group having the formula SiR 2 O 1/2 ,
Y 2 is a divalent hydrocarbon radical having 2 to 30 carbon atoms which is bonded to a group having the formula SiRO 2/2 , and
x 1 and x 2 are, independently, 0 or a positive integer,
with the proviso that the sum of x 1 +x 2 is x,
wherein x is on average more than 5 and less than 100,
(2) fillers, and
(3) organopolysiloxane resins comprising units of formula
R 2 e (R 3 O) f SiO (4-e-f)/2   (V),

wherein
R 2 is identical or different and represents a hydrogen atom or a monovalent, optionally substituted, SiC-bonded hydrocarbon radical having 1 to 30 carbon atoms,
R 3 is identical or different and represents a hydrogen atom or a monovalent, optionally substituted hydrocarbon radical having 1 to 4 carbon atoms,
e is 0, 1, 2 or 3, and
f is 0, 1, 2, or 3,
with the proviso that the sum of e+f is not more than 3 and that the sum of e+f is 2 in less than 50% of all units of formula (V) in the organopolysiloxane resin.

2. The defoamer formulation of claim 1 , wherein R 1 is a methyl or vinyl radical.

3. The defoamer formulation of claim 1 , wherein x is on average more than 10 and less than 60.

4. The defoamer formulation of claim 1 , wherein Y and Y 1 and Y 2 are each a radical of the formula —CH 2 CH 2 —.

5. The defoamer formulation of claim 1 , wherein the organopolysiloxanes (1) are produced by reacting:
(A) oligomeric or polymeric organosilicon compounds containing units of formula
R 1 R 2 SiO 1/2   (II),

units of formula
R 2 SiO 2/2   (III),

and units of formula
HRSiO 2/2   (VII),

with the proviso that
at least one alkenyl radical R 1 per molecule is present,
the sum of the units HRSiO 2/2 and R 1 R 2 SiO 1/2 is on average greater than 2.0, and the number of alkenyl radicals R 1 is on average greater than the number of Si-bonded hydrogen atoms
and optionally
(B) oligomeric or polymeric organosilicon compounds containing units of formula
R 6 R 2 SiO 1/2   (VIII), and

units of formula
R 2 SiO 2/2 (III),

wherein
R 6 is an alkenyl radical having 2 to 30 carbon atoms, in the presence of
(C) catalysts which promote the addition of Si-bonded hydrogen onto aliphatic double bonds, wherein the ratio of aliphatic double bonds in the components (A) and optionally (B) to Si-bonded hydrogen in component (A) is 1.2 to 10.

6. The defoamer formulation of claim 5 , wherein the ratio of aliphatic double bonds in the components (A) and optionally (B) to Si-bonded hydrogen in the component (A) is 1.5 to 5.0.

7. The defoamer formulation as claimed in claim 5 , wherein the organosilicon compounds (A) have the formula
R 1 R 2 SiO-(SiR 2 O) x -(HSiR) y —O-SiR 2 R 1   (IX),

wherein
y is on average at least 0.5, and on average not more than 1.5,
with the proviso that at least one alkenyl radical R 1 per molecule is present,
the sum of the units HRSiO 2/2 and R 1 R 2 SiO 1/2 is on average greater than 2.0,
and the number of alkenyl radicals R 1 is on average greater than the number of Si-bonded hydrogen atoms.

8. The defoamer formulation as claimed in claim 5 , wherein the organosilicon compounds (A) have the formula
R 1 R 2 SiO-(SiR 2 O) x -(HSiR) y —O-SiR 2 R 1   (IX),

wherein
y is on average at least 0.6, and on average not more than 1.2,
with the proviso that at least one alkenyl radical R 1 per molecule is present,
the sum of the units HRSiO 2/2 and R 1 R 2 SiO 1/2 is on average greater than 2.0, and the number of alkenyl radicals R 1 is on average greater than the number of Si-bonded hydrogen.

9. The defoamer formulation of claim 5 , wherein the organosilicon compounds (B) employed are those of formula
R 6 R 2 SiO—(SiR 2 O) z —O—SiR 2 R 6   (X),

wherein
R each is identical or different and is monovalent SiC-bonded hydrocarbon radical having 1 to 30 carbon atoms which optionally contain one or more nonadjacent O-atoms and which is free from aliphatic carbon-carbon multiple bonds and
R 6 is an alkenyl radical having 2 to 30 carbon atoms,
z is on average more than 5, preferably more than 10, and less than 1000, preferably less than 500, particularly preferably less than 250.

10. The defoamer formulation of claim 7 , wherein the organosilicon compounds (B) employed are those of formula
R 6 R 2 SiO—(SiR 2 O) z —O—SiR 2 R 6   (X),

wherein
R each is identical or different and is monovalent SiC-bonded hydrocarbon radical having 1 to 30 carbon atoms which optionally contain one or more nonadjacent O-atoms and which is free from aliphatic carbon-carbon multiple bonds and
R 6 is an alkenyl radical having 2 to 30 carbon atoms,
z is on average more than 5, preferably more than 10, and less than 1000, preferably less than 500, particularly preferably less than 250.

11. The defoamer formulation of claim 1 , further comprising one or more constituents (4) through (7);
(4) polyorganosiloxanes of formula

wherein
R 4 each is identical or different and is R or —OR 5 , wherein
R 5 is a hydrogen atom or a monovalent, optionally substituted hydrocarbon radical having 1 to 25 carbon atoms,
m is an integer from 1 to 2500,
n is an integer from 2 to 20,
wherein the polyorganosiloxanes may also contain small proportions of T units (R 4 SiO 3/2 ) and/or Q units (SiO 2 ),
(5) water-insoluble organic compounds,
(6) polyether-modified polysiloxanes which are linear or branched and contain at least one polyether group,

and
(7) alkaline or acidic catalysts or their reaction products with one of the components (1) to (6).

12. The defoamer formulation of claim 1 , wherein the defoamer formulation has a loss factor (tan delta) at 100 rad/s between 1.0 and 5.0, wherein over the frequency range of 1 to 100 rad/s the difference in the loss factor (A tan delta) is less than 1.5, and the defoamer has a viscosity at 100 rad/s between 1000 mPas and 300,000 mPas, in each case measured at 25° C., wherein the loss factor and the viscosity are determined according to DIN 53019-4.

13. The defoamer formulation of claim 1 , wherein the defoamer formulation has a loss factor (tan delta) at 100 rad/s between 1.5 and 3.0, wherein over the frequency range of 1 to 100 rad/s the difference in the loss factor

Assignees

• Wacker Chemie Ag

Inventors

• Brehm Christof
• Burger Willibald
• Ziche Wolfgang

Classifications

• C08L2205/035

  containing four or more polymers in a blend · CPC title

• C11D3/0026

  Low foaming or foam regulating compositions · CPC title

• D21H21/12

  Defoamers · CPC title

• C11D3/3734

  Cyclic silicones · CPC title

• D21H17/59

  obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon · CPC title