CA1093929A - Antifoam for compositions compatible with silicon oil - Google Patents
Antifoam for compositions compatible with silicon oilInfo
- Publication number
- CA1093929A CA1093929A CA289,076A CA289076A CA1093929A CA 1093929 A CA1093929 A CA 1093929A CA 289076 A CA289076 A CA 289076A CA 1093929 A CA1093929 A CA 1093929A
- Authority
- CA
- Canada
- Prior art keywords
- antifoam
- perfluoroalkylpolyether
- composition
- poly
- dimethylsiloxane
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D19/00—Degasification of liquids
- B01D19/02—Foam dispersion or prevention
- B01D19/04—Foam dispersion or prevention by addition of chemical substances
- B01D19/0404—Foam dispersion or prevention by addition of chemical substances characterised by the nature of the chemical substance
- B01D19/0409—Foam dispersion or prevention by addition of chemical substances characterised by the nature of the chemical substance compounds containing Si-atoms
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L83/00—Compositions of macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon with or without sulfur, nitrogen, oxygen or carbon only; Compositions of derivatives of such polymers
- C08L83/04—Polysiloxanes
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- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Toxicology (AREA)
- Dispersion Chemistry (AREA)
- Lubricants (AREA)
Abstract
ABSTRACT
An antifoam composition for reducing foaming tendencies in lubricating oil compositions is described which com-prises a major portion of (A) poly(dimethylsiloxane) having the general formula:
wherein R is a methyl group and n has a value such that the average viscosity at 25°C is between 5?? and 500??, and a major amount finely dispersed therein of (B) perfluoroalkylpolyether of the formula:
F- [CF(CF3)CF20 ]xC2F5 in which x has a value of from 10 to 41. A method of dispersing such perfluoroalkylpolyether in a lubricating oil is also described.
An antifoam composition for reducing foaming tendencies in lubricating oil compositions is described which com-prises a major portion of (A) poly(dimethylsiloxane) having the general formula:
wherein R is a methyl group and n has a value such that the average viscosity at 25°C is between 5?? and 500??, and a major amount finely dispersed therein of (B) perfluoroalkylpolyether of the formula:
F- [CF(CF3)CF20 ]xC2F5 in which x has a value of from 10 to 41. A method of dispersing such perfluoroalkylpolyether in a lubricating oil is also described.
Description
1~ 9Z,~3 This invention relates to an antifoam composition for lubricating oil compositions and a process of dispersing said composition into the lubricating oil compositions. ~ore particularly it relates to compositions comprising certain poly (dimethylsiloxanes) mixed with a minor portion of certain perfluoroalkylpolyethers.
In many applications, lubricating oil com-positions are employed as functional fluids or power transmitting fluids. In such uses, the fluids are pumped or circulated at high speeds which causes the entrainment of air in the fluid with the resultant ! production of considerable amount of foam.
Foam in a functional fluid is highly de-trimental to the operation of an automatic transmission or an hytraulic device. The foaming tendency of oil compositions is recognized as a serious problem and industry-adopted specifications have been set on this lubricating oil property.
The foaming tendency of a lubricating oil composition is intensified by the presence of many ; additives conventionally employed in lubricating oils.
The problem is generally further aggravated where the lubricating compositions contain poly(organosiloxanes) as major constituents.
. . .
The use of perfluoroalkylpolyethers as ; antifoam agents in lubricating and hydraulic fluids has been described in U.S. patent 3,77j,324 and in U.S. Patent 4059534 issued November 22, 1977.
In industry, it is common practice to disperse anti-; 30 foam agents such as perfluoroalkylpolyethers in foaming fluids by first dissolving the said antifoam additives" i~-~ . ~ . s ~
in solvents which are th~mselves soluble in the foaming :~0~35~29 fluids (e.g. U.S. 3,775,324). A useful, very fine dispersion of the antifoam is thus obtained. The only known hydrocarbon oil soluble solvents for the per- -fluoroalkylpolyethers of the invention are poly- or per-halocarbons such as trichlorotrifluoroethane. However, it has been shown by M.Z. Fainman ("Halogenated Solvents and Corrosion in Dynamic Systems, Lubrication Engineering, pp. 556-558, November 1974.) that a parts per million concentration of such halocarbons can cause grave cor-rosion problems in certain applications such as hydraulic systems.
It has now been discovered that compositions of matter can be prepared which contain minor amounts of perfluoroalkylpolyethers as antifoam agents, and which have excellent corrosion, and antifoaming properties.
It is therefore an object of this invention to provide a novel antifoam composition which can be used directly in lubricating oils which are compatible with silicone oil.
It is another object of this invention to provide a method of dispersing perfluoroalkylpolyethers in lubricating oil compositions which are compatible with poly(dimethylsiloxane).
These objects are obtained by means of an antifoam composition comprisinga mixture of a major portion of (A) poly(dimethylsiloxane) having the general formula:
lR
R-Si-0- ~ Si-0¦ -Si-R
R R / R
In many applications, lubricating oil com-positions are employed as functional fluids or power transmitting fluids. In such uses, the fluids are pumped or circulated at high speeds which causes the entrainment of air in the fluid with the resultant ! production of considerable amount of foam.
Foam in a functional fluid is highly de-trimental to the operation of an automatic transmission or an hytraulic device. The foaming tendency of oil compositions is recognized as a serious problem and industry-adopted specifications have been set on this lubricating oil property.
The foaming tendency of a lubricating oil composition is intensified by the presence of many ; additives conventionally employed in lubricating oils.
The problem is generally further aggravated where the lubricating compositions contain poly(organosiloxanes) as major constituents.
. . .
The use of perfluoroalkylpolyethers as ; antifoam agents in lubricating and hydraulic fluids has been described in U.S. patent 3,77j,324 and in U.S. Patent 4059534 issued November 22, 1977.
In industry, it is common practice to disperse anti-; 30 foam agents such as perfluoroalkylpolyethers in foaming fluids by first dissolving the said antifoam additives" i~-~ . ~ . s ~
in solvents which are th~mselves soluble in the foaming :~0~35~29 fluids (e.g. U.S. 3,775,324). A useful, very fine dispersion of the antifoam is thus obtained. The only known hydrocarbon oil soluble solvents for the per- -fluoroalkylpolyethers of the invention are poly- or per-halocarbons such as trichlorotrifluoroethane. However, it has been shown by M.Z. Fainman ("Halogenated Solvents and Corrosion in Dynamic Systems, Lubrication Engineering, pp. 556-558, November 1974.) that a parts per million concentration of such halocarbons can cause grave cor-rosion problems in certain applications such as hydraulic systems.
It has now been discovered that compositions of matter can be prepared which contain minor amounts of perfluoroalkylpolyethers as antifoam agents, and which have excellent corrosion, and antifoaming properties.
It is therefore an object of this invention to provide a novel antifoam composition which can be used directly in lubricating oils which are compatible with silicone oil.
It is another object of this invention to provide a method of dispersing perfluoroalkylpolyethers in lubricating oil compositions which are compatible with poly(dimethylsiloxane).
These objects are obtained by means of an antifoam composition comprisinga mixture of a major portion of (A) poly(dimethylsiloxane) having the general formula:
lR
R-Si-0- ~ Si-0¦ -Si-R
R R / R
2.
1C)5~35`29 wherein R is a methyl group and n has a value such that the average viscosity at 25C is between 5 cs and 500 cs, and a minor amount finely dispersed therein of (B) perfluoroalkylpolyether of the formula:
F- ~C~(CF3)CF20 ~ 2 5 ; in which x has a value of from 10 to 41.
These objects are also obtained by means of a method of dispersing perfluoroalkylpolyether in a lubricating oil composition which is compatible with poly(dimethylsiloxane) which method comprises:
mixing a major amount of (A) poly(dimethylsiloxane) of the formula R R ~ R
R-Si-0- Si-0 -Si-R
R R n R
wherein R is a methyl group and n has a value such that the average viscosity at 25 C is between 5 cs and 500 cs, and a minor amount finely dispersed therein of (B) perfluoroalkylpolyether of the formula:
F- ~CF(CF3) CF20 ] C2F5 in which x has a value of from lO to 41, into said lub-ricating oil composition to provide a concentration of from 1 ppm to 500 ppm of said perfluoroalkylpolyether in the total composition.
, More specifically, one aspect of this invention may be described as a foam inhibiting composition com-prising a mixture of a major portion of (A) trimethyl 30 end-blocked poly(dimethylsiloxane) having viscosity at 25 C between 5 centistokes and 500 centistokes, and a B minor amount finely dispersed therein of ~B) perfluoroalkyl-
1C)5~35`29 wherein R is a methyl group and n has a value such that the average viscosity at 25C is between 5 cs and 500 cs, and a minor amount finely dispersed therein of (B) perfluoroalkylpolyether of the formula:
F- ~C~(CF3)CF20 ~ 2 5 ; in which x has a value of from 10 to 41.
These objects are also obtained by means of a method of dispersing perfluoroalkylpolyether in a lubricating oil composition which is compatible with poly(dimethylsiloxane) which method comprises:
mixing a major amount of (A) poly(dimethylsiloxane) of the formula R R ~ R
R-Si-0- Si-0 -Si-R
R R n R
wherein R is a methyl group and n has a value such that the average viscosity at 25 C is between 5 cs and 500 cs, and a minor amount finely dispersed therein of (B) perfluoroalkylpolyether of the formula:
F- ~CF(CF3) CF20 ] C2F5 in which x has a value of from lO to 41, into said lub-ricating oil composition to provide a concentration of from 1 ppm to 500 ppm of said perfluoroalkylpolyether in the total composition.
, More specifically, one aspect of this invention may be described as a foam inhibiting composition com-prising a mixture of a major portion of (A) trimethyl 30 end-blocked poly(dimethylsiloxane) having viscosity at 25 C between 5 centistokes and 500 centistokes, and a B minor amount finely dispersed therein of ~B) perfluoroalkyl-
3.
939Z~
polyether of the formula:
F- LCF(CF3)CF20 ] XC2F5 in which x has a value which provides an average molecular weight for the perfluoroalkylpolyether ranging from about 2,000 to 7,000. -The dimethylsiloxane oils employed in this in-vention as well as methods for their preparation are well known and consist essentially of siloxy units of the formula R2SiO and end-blocking siloxy units of the formula R3SiO wherein R is a methyl radical. As employed herein such siloxane oils are essentially linear siloxane polymers having a viscosity in the range of about 5 to about 500 centistokes at about 25C, preferably about 10 to about 350 centistokes at about 25C, and most preferably about 50 to about 200 centistokes at about 25 C. These siloxane oils are also conventionally represented by the average formula:
R3Sio(R2SiO)xSiR3 wherein R is a methyl radical and x is an integer having a value that corresponds to the viscosity of the particular siloxane. FOr example, a trimethyl end-blocked dimethyl siloxane oil having a viscosity of 100 centistokes at 25 C
can be represented as having the average formula:
Me3SiO(Me2SiO)48SiMe3 wherein Me is a methyl group.
It is to be understood, of course, that while the dimethylsiloxane oils used in this invention can be discrete chemical compounds, they are usually mixtures of various discrete siloxane species, due at least in part to the fact the starting materials used to produce the siloxane oils are themselves usually mixtures. Thus, it is obvious that the dimethyl siloxane oils employed herein need not be fractionated as by distillation but may be sparged (i.e. stripped of lights~ or unsparged.
10~3~
The perfluoroalkylpolyethers of the invention are also well known in the art, and have the general formula:
F- ¦CF(CF3)C~20 ~ X-C2F5 in which x has a value providing an average molecular weight for the perfluoroalkylpolyether ranging from about 2,000 to 7,000. This molecular weight range will correspond to values for x of about 10 to 41. The preferred perfluoroalkylpolyethers are those in which the average molecular weight ranges from about 2,000 to about 5,500 for which values of x correspond to about ll to 32, respectively. Commercial products cor-responding to this description are Krytox fluids manu-factures by E. I. DuPont de Nemours & Company. Specific examples of effective perfluoroalkylpolyethers are des-cribed below.
The foam inhibiting compositions of matter of this invention are prepared by mixing the two liquids in a high shear mixer until a fine dispersion of a minor portion of perfluoro-alkylpolyether is achieved. Such a state is typically evidenced by the development of haziness in the mixture. The proportions of poly(dimethylsiloxane) to perfluoroalkylpolyether should be selected so as to provide a concentration of perfluoroalkylpolyether of between 1 to 500 ppm in the final lubricating oil composition and a concentration of dimethylsiloxane polymer in said lubricating oil which is consistent with the intended application. Because the poly(dimethyl siloxane) acts as a carrier for the perfluoro-alkylpolyether, it is necessarily the major component of the antifoam compositions. While not wishing to be bound by a pre-cise range, the proportions of components (A~ to (B) typically range from about 90 to 99.9 per cent by weight of (A) to about 10 to 0.1 per cent by weight of (B), and preferably from about 97 to 99.5 per cent by weight of (A) to about 3 to 0.5 per cent by weight of (B).
*Trade Mark 5.
LB
z~
It is to be understood that the stability and quality or the dispersion is greatly affected by the shear rate of the mixer, and the viscosity and concentration of the dimethylsiloxane polymer. It is therefore obvious that not every possible proportionate range by weight employable herein for every silicone oil and perfluoroalkylpolyether component of this invention may give the same degree of results. However, experience has shown that compositions of the invention which are mixed llntil they appear to be homogeneous to an observer unaided by optical instruments or other devices, and which are used as foam inhibiting additives promptly, preferably within 24 hours, tend ~o give the most satisfactory and consistent - results.
Those lubricating oil compositions with which the antifoam compositions of matter of this invention may be used, are well known in the art. While such lubricating oil com-positions are most preferably limited in that they must be compatible with the poly(dimethylsiloxane) oils of the anti-foam compositions of the invention, they need not contain silicone oils. Typically, however, the lubricating composi-tions do contain silicone oils; for example, compositions as described in U.S. Patent 3,974,080, and U.S. Patents 4059534 issued Nove~[ber 22, 1977 and U. S . 4097393 issued June 27, 1978.
The antifoam compositions of the invention can be mixed with the desired lubricating oils in any conventional ~anner in proportions which provide the minute quantities of perfluoroalkylpolyether required to inhibit foaming. Generally, the two liquids need only be mixed together in the proportions desired while stirring at room temperature.
The following examples illustrate the present invention:
EXAMP~E No. 1 ; 198 grams of poly(dimethylsiloxane) having a viscosity of 50 cs at 25 C were agitated in a household type blender while 2 grams of Krytox 143 AZ, a perfluoroalkylpolyether as described above, were added dropwise. The resultant 1 emulsion was stable for more than 24 hours.
*Trade Mark 6.
..
'- iO'~3<3~
E~A*PLE No. 2 198 grams of poly(dimethylsiloxana) having a viscosity of 50 cs at 25 C were agitated in a household type blender while 2 grams of Krytox 143 AD* a perfluoroalkylpolyether as described above, were added dropwise. The resultant 1%
emulsion was stable for more than 24 hours.
EXAMPLE No. 3 A~s described in Examples 1 and 2, ~rytox 143 AZ *
was dispersed in p~ly(dimethylsiloxane) having a viscosity of 100 cs at 25 C; the proportion by weight was 0.5% Krytox to 99.52 poly(dimethylsiloxane). When added with stirring to a lubricating oil containing poly(dimethylsiloxane) of 100,000 cs at 25C, a propylene oligomer, and various conventional lubri-cating oil additives, a S0 ppm concentration by weight of the a~tifoam composition markedly decreased the foaming tendency.
EXAMPLE Nos. _-6 - The antifoam composition of Example 1 was added with stirring to the lubrica~t compositions shown in Table 1.
These flulds were tested for foaming characteristics before and after the atdition of sufficient antifoam composition to give the quantity of perfluoroalkylpolyether indicated.
As see~ by the test results presented in Table 1, the method of dispersion is effective at various concentrations in different lubricants consisting of hydrocarbon oil and silicone oil.
E ~MPLE Nos. 7 and 8 These t~o examples demonstrate the effectiveness of the antifoam of E~ample 1 in solutions containing silicone oils other ~han poly(dimeebylsiloxane).
EXAMPLE Nos. 9 and 10 These two examples demonstrate the effectiveness of the antifoam compositions of Example 2.
EXAMP~E No. 11 This exa~ple demonstrates the effectiveness of the antifoam composition of Example 1 in a hydrocarbon lubri~
cating oil which is compatible with silicone oil.
EX~MELE No. 12 This e~ample uses a standard dispersion method for comparison with the process of this invention. The per-fluoroalkylpolyether was dissolved in UCOU 113 DCE, a trich-lorotrifluoroethane/dichloroethane azeotrope, until an antifoam concentration of 1.60% was obtained. Sufficient antifoam con-centrate was added to the solution of Example 4 to arrive at the quantity of perfluoropolyether indicated. This e~ample is ~rade Mark 7.
~0~;392~
included for comparison purposes and does not describe an object of the present invention.
EXAMPLE Nos. 13 and 14 _ . _ . .
These two examples illustrate the superior per-formance of antifoam compositions of this invention compared to similar compositions without dimethylsiloxane polymer.
Example 13 is included for comparison purposes and does not constitute an object of the present invention.
An additional advantage of compositions of the present invention is the increased stabillty of these compo-sitions. This is demonstrated in that after standin~ for 24 hours, the concentrate of Example 13 had clearly separated into its constituents while the concentrate of Example 14 was still usable.
As can be seen from results of Table I, the dispersion process of the invention is as efficient as the previously known process while, at the same time, eliminating the use of corrosive halocarbon solvents.
Various modifications and variations of this invention will be obvious to a worker skilled in the art and it is to be understood that such modifications and variations are to be included within the purview of this application and the spirit and scope of the appended claims.
.
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polyether of the formula:
F- LCF(CF3)CF20 ] XC2F5 in which x has a value which provides an average molecular weight for the perfluoroalkylpolyether ranging from about 2,000 to 7,000. -The dimethylsiloxane oils employed in this in-vention as well as methods for their preparation are well known and consist essentially of siloxy units of the formula R2SiO and end-blocking siloxy units of the formula R3SiO wherein R is a methyl radical. As employed herein such siloxane oils are essentially linear siloxane polymers having a viscosity in the range of about 5 to about 500 centistokes at about 25C, preferably about 10 to about 350 centistokes at about 25C, and most preferably about 50 to about 200 centistokes at about 25 C. These siloxane oils are also conventionally represented by the average formula:
R3Sio(R2SiO)xSiR3 wherein R is a methyl radical and x is an integer having a value that corresponds to the viscosity of the particular siloxane. FOr example, a trimethyl end-blocked dimethyl siloxane oil having a viscosity of 100 centistokes at 25 C
can be represented as having the average formula:
Me3SiO(Me2SiO)48SiMe3 wherein Me is a methyl group.
It is to be understood, of course, that while the dimethylsiloxane oils used in this invention can be discrete chemical compounds, they are usually mixtures of various discrete siloxane species, due at least in part to the fact the starting materials used to produce the siloxane oils are themselves usually mixtures. Thus, it is obvious that the dimethyl siloxane oils employed herein need not be fractionated as by distillation but may be sparged (i.e. stripped of lights~ or unsparged.
10~3~
The perfluoroalkylpolyethers of the invention are also well known in the art, and have the general formula:
F- ¦CF(CF3)C~20 ~ X-C2F5 in which x has a value providing an average molecular weight for the perfluoroalkylpolyether ranging from about 2,000 to 7,000. This molecular weight range will correspond to values for x of about 10 to 41. The preferred perfluoroalkylpolyethers are those in which the average molecular weight ranges from about 2,000 to about 5,500 for which values of x correspond to about ll to 32, respectively. Commercial products cor-responding to this description are Krytox fluids manu-factures by E. I. DuPont de Nemours & Company. Specific examples of effective perfluoroalkylpolyethers are des-cribed below.
The foam inhibiting compositions of matter of this invention are prepared by mixing the two liquids in a high shear mixer until a fine dispersion of a minor portion of perfluoro-alkylpolyether is achieved. Such a state is typically evidenced by the development of haziness in the mixture. The proportions of poly(dimethylsiloxane) to perfluoroalkylpolyether should be selected so as to provide a concentration of perfluoroalkylpolyether of between 1 to 500 ppm in the final lubricating oil composition and a concentration of dimethylsiloxane polymer in said lubricating oil which is consistent with the intended application. Because the poly(dimethyl siloxane) acts as a carrier for the perfluoro-alkylpolyether, it is necessarily the major component of the antifoam compositions. While not wishing to be bound by a pre-cise range, the proportions of components (A~ to (B) typically range from about 90 to 99.9 per cent by weight of (A) to about 10 to 0.1 per cent by weight of (B), and preferably from about 97 to 99.5 per cent by weight of (A) to about 3 to 0.5 per cent by weight of (B).
*Trade Mark 5.
LB
z~
It is to be understood that the stability and quality or the dispersion is greatly affected by the shear rate of the mixer, and the viscosity and concentration of the dimethylsiloxane polymer. It is therefore obvious that not every possible proportionate range by weight employable herein for every silicone oil and perfluoroalkylpolyether component of this invention may give the same degree of results. However, experience has shown that compositions of the invention which are mixed llntil they appear to be homogeneous to an observer unaided by optical instruments or other devices, and which are used as foam inhibiting additives promptly, preferably within 24 hours, tend ~o give the most satisfactory and consistent - results.
Those lubricating oil compositions with which the antifoam compositions of matter of this invention may be used, are well known in the art. While such lubricating oil com-positions are most preferably limited in that they must be compatible with the poly(dimethylsiloxane) oils of the anti-foam compositions of the invention, they need not contain silicone oils. Typically, however, the lubricating composi-tions do contain silicone oils; for example, compositions as described in U.S. Patent 3,974,080, and U.S. Patents 4059534 issued Nove~[ber 22, 1977 and U. S . 4097393 issued June 27, 1978.
The antifoam compositions of the invention can be mixed with the desired lubricating oils in any conventional ~anner in proportions which provide the minute quantities of perfluoroalkylpolyether required to inhibit foaming. Generally, the two liquids need only be mixed together in the proportions desired while stirring at room temperature.
The following examples illustrate the present invention:
EXAMP~E No. 1 ; 198 grams of poly(dimethylsiloxane) having a viscosity of 50 cs at 25 C were agitated in a household type blender while 2 grams of Krytox 143 AZ, a perfluoroalkylpolyether as described above, were added dropwise. The resultant 1 emulsion was stable for more than 24 hours.
*Trade Mark 6.
..
'- iO'~3<3~
E~A*PLE No. 2 198 grams of poly(dimethylsiloxana) having a viscosity of 50 cs at 25 C were agitated in a household type blender while 2 grams of Krytox 143 AD* a perfluoroalkylpolyether as described above, were added dropwise. The resultant 1%
emulsion was stable for more than 24 hours.
EXAMPLE No. 3 A~s described in Examples 1 and 2, ~rytox 143 AZ *
was dispersed in p~ly(dimethylsiloxane) having a viscosity of 100 cs at 25 C; the proportion by weight was 0.5% Krytox to 99.52 poly(dimethylsiloxane). When added with stirring to a lubricating oil containing poly(dimethylsiloxane) of 100,000 cs at 25C, a propylene oligomer, and various conventional lubri-cating oil additives, a S0 ppm concentration by weight of the a~tifoam composition markedly decreased the foaming tendency.
EXAMPLE Nos. _-6 - The antifoam composition of Example 1 was added with stirring to the lubrica~t compositions shown in Table 1.
These flulds were tested for foaming characteristics before and after the atdition of sufficient antifoam composition to give the quantity of perfluoroalkylpolyether indicated.
As see~ by the test results presented in Table 1, the method of dispersion is effective at various concentrations in different lubricants consisting of hydrocarbon oil and silicone oil.
E ~MPLE Nos. 7 and 8 These t~o examples demonstrate the effectiveness of the antifoam of E~ample 1 in solutions containing silicone oils other ~han poly(dimeebylsiloxane).
EXAMPLE Nos. 9 and 10 These two examples demonstrate the effectiveness of the antifoam compositions of Example 2.
EXAMP~E No. 11 This exa~ple demonstrates the effectiveness of the antifoam composition of Example 1 in a hydrocarbon lubri~
cating oil which is compatible with silicone oil.
EX~MELE No. 12 This e~ample uses a standard dispersion method for comparison with the process of this invention. The per-fluoroalkylpolyether was dissolved in UCOU 113 DCE, a trich-lorotrifluoroethane/dichloroethane azeotrope, until an antifoam concentration of 1.60% was obtained. Sufficient antifoam con-centrate was added to the solution of Example 4 to arrive at the quantity of perfluoropolyether indicated. This e~ample is ~rade Mark 7.
~0~;392~
included for comparison purposes and does not describe an object of the present invention.
EXAMPLE Nos. 13 and 14 _ . _ . .
These two examples illustrate the superior per-formance of antifoam compositions of this invention compared to similar compositions without dimethylsiloxane polymer.
Example 13 is included for comparison purposes and does not constitute an object of the present invention.
An additional advantage of compositions of the present invention is the increased stabillty of these compo-sitions. This is demonstrated in that after standin~ for 24 hours, the concentrate of Example 13 had clearly separated into its constituents while the concentrate of Example 14 was still usable.
As can be seen from results of Table I, the dispersion process of the invention is as efficient as the previously known process while, at the same time, eliminating the use of corrosive halocarbon solvents.
Various modifications and variations of this invention will be obvious to a worker skilled in the art and it is to be understood that such modifications and variations are to be included within the purview of this application and the spirit and scope of the appended claims.
.
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Claims (5)
- The embodiments of the invention in which an exclusive property of privilege is claimed are defined as follows:
l. An antifoam composition comprising a mixturo of from 90% to 99.9% by weight of (A) poly(dimethylsiloxane) having the general formula:
wherein R is a methyl group and n has a value such that the average viscosity at 25 C is between 5cs and 500cs, and from 10% to 0.1% by weight of (B) perfluoroalkylpolyether of the formula:
P - [CF(CF3)CF2 }] x C2F3 in which x has a value of from 10 to 41. - 2. An antifoam composition as claimed in claim 1 wherein x has a value of from 11 to 32.
- 3. An antifoam composition as claimed in claim 2 wherein said mixture comprises from 97% to 99.5% by weight of (A) and from 3% to 0.5% by weight of (B).
- 4. A method of dispersing perfluoroalkylpolyether in a lubricating oil composition which is compatible with poly(dimethylsiloxane) which method comprises: mixing the antifoam composition or claim 1 into said lubricating oil composition to provide a concentration of from 1 ppm to 500 ppm of said per1uoroalkyIpolyether in the total composition.
- 5. A method as claimed in claim 4 wherein said concentration has from 5 ppm to 100 ppm of said perfluoroalkylpolyether in the total composition.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA289,076A CA1093929A (en) | 1977-10-17 | 1977-10-17 | Antifoam for compositions compatible with silicon oil |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA289,076A CA1093929A (en) | 1977-10-17 | 1977-10-17 | Antifoam for compositions compatible with silicon oil |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1093929A true CA1093929A (en) | 1981-01-20 |
Family
ID=4109807
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA289,076A Expired CA1093929A (en) | 1977-10-17 | 1977-10-17 | Antifoam for compositions compatible with silicon oil |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1093929A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112742073A (en) * | 2021-01-03 | 2021-05-04 | 朱生寿 | Modified tung linoleic acid polyether ester coating defoaming agent and preparation method thereof |
-
1977
- 1977-10-17 CA CA289,076A patent/CA1093929A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN112742073A (en) * | 2021-01-03 | 2021-05-04 | 朱生寿 | Modified tung linoleic acid polyether ester coating defoaming agent and preparation method thereof |
| CN112742073B (en) * | 2021-01-03 | 2022-07-26 | 山东峰泉新材料有限公司 | Modified tung linoleic acid polyether ester coating defoaming agent and preparation method thereof |
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