DE2420955A1 - ANTI-FOAM PREPARATION - Google Patents

Description

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D / p /.- lng. A. Grunscker

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8 Munich 22, Maximiltenstr. 43 Ο / ΟΠΟΕΓΙΓ

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BUCKT-IAH LABOHATOHIES,

1256 North McLean Boulevard, Memphis, Tennessee 38108, USA

Antifoam preparation

The invention relates to a new antifoam preparation and its use in a method for defoaming aqueous systems; it relates in particular to antifoam preparations made from certain diamides, a silicone oil and a mineral oil.

The term "antifoam preparation" as used herein includes Foam control agents both to prevent foam formation and to reduce an already existing one Foam in an aqueous system.

The foaming of liquids (foam formation) is a frequent cause of malfunctions in large-scale industrial processes. The previously known chemical methods for preventing or reducing foam formation include the addition of various compounds such as amides, alcohols, oils, hydrophobic minerals, silicone oils and the like and mixtures these materials.

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There are many large-scale processes in which solutions or suspensions are handled in different basic systems be, in which foam formation in the system must be reduced or prevented in order to interfere with the effective Avoid performing the procedure through the foam. Examples of such disorders are foam formation in textile processing, foam formation in boiling sugar beet runoff and foam formation in paper pulp suspensions. In addition, it is very desirable that paints, coatings and the like do not foam in order to thereby reduce the Avoid defacing the coated surface due to air bubbles. There are also many more Cases where reducing or preventing foaming is very desirable.

In the paper industry, foaming problems occur when handling the treatment liquids (finishing baths). When cooking wood pulp in an alkaline Solution in the soda or sulfate papermaking process results in a black liquid. It contains almost all chemicals used during processing along with that extracted from the wood organic material. By processing wood with a high resin content, the foam formation is increased. More resinous woods are used in the sulphate process than in the soda process and for this reason is the resulting foam formation stronger. Foaming occurs primarily when the wood pulp is washed and stirred during the cleaning process.

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Many antifoam preparations are already known and currently available in the stores. These preparations solve specific foaming problems to a greater or lesser extent. Some of them are more effective than others and some of them are particularly effective with respect to certain aqueous systems. The effectiveness of antifoam preparations however, it is completely unpredictable and minor or major changes or modifications are often decisive about success or failure, especially when treating a specific type of foam formation;

In the formulation (manufacture) of a commercially acceptable foam control material, particularly for use in pulp mills, must take a number of factors into account. A foam control material should have the ability to produce a already formed foam to reduce to a low value within a short period of time, and moreover it should have the ability to prevent the formation of foam in the aqueous medium over a prolonged period of time if it does so has been added once. In addition, the product should be easily pumpable so that it can be transported from the storage facility to the site where it is needed without tending to gel. It also has a long shelf life essential factor for such a preparation, i.e. the preparation should have very little or no tendency to separate into their components when stored over a have a longer period of time.

General defoaming agents or antifoam preparations and those for similar uses as the antifoam preparation of the invention are for example in the US patent

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Writings 3,076,768, 3,652,453, 3,666,681, 3,673,105, 3,677 and 3,723,342. In addition, US Pat. No. 2,469,450 uses one of the components of the invention Preparation as an effective defoaming agent for steam boilers described.

Despite the extensive literature on antifoam preparations one is constantly on the lookout for an antifoam agent (defoaming agent) that is effective, is economical and easy to use, and one is particularly looking for such an antifoam agent, which is effective against the type of foam found in pulp mills and the like.

The aim of the invention is therefore to provide an improved antifoam preparation (Defoaming preparation) indicate the specific Contains aliphatic diamides and silicone oils dispersed in a mineral oil. The aim of the invention is also to provide a method indicate, with the help of which it is possible, using this new antifoam preparation, the foam formation to control.

It has now been found that these goals can be achieved with the antifoam preparation given below.

The invention relates to an antifoam preparation which is characterized in that it consists essentially of

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(A) 2 to 20% by weight of a diamide of the general formula

• HO OH

I Il ti I

R-N-C-S * -C-N-Pv

where mean:

R is an alkyl group with 8 to 22 carbon atoms and R ^{f is} a saturated or unsaturated alkylene group with 1 Ms 8 carbon atoms,

(B) 0.5 to 5% by weight of a silicone oil from the diraethylpolysiloxane group, Methyl hydrogen polysiloxane or another commercially available Organopolysiloxane as defined below, and

(C) from 75 to 97.5 wt -.% Of a mineral oil, preferably a paraffinic mineral
(100 ° F) from about 100 SUS.

highly paraffinic mineral oil with a viscosity at 38 ° C

The method forming a further subject of the invention is characterized in that an antischaura preparation the composition given above in effective amounts used in aqueous systems, which tend to. undesirable foaming. This method is particularly applicable to pulp mill fluids, such as the black liquids and brown material washer liquids that occur in the process.

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The following are preferred embodiments of the invention both with regard to the preparation itself and with regard to the process for producing the preparations and with regard to the use of these preparations.

The antifoam preparations according to the invention (antifoam agents) contain three essential components.

The first essential ingredient is an aliphatic diamide the general formula

HO OH

| - It 11 I.

R-N-C-R * -C-N-R

wherein R is an alkyl group having 8 to 22 carbon atoms and R ^{1 is} a saturated or unsaturated alkylene group having 1 to 8, preferably 4 to 8 carbon atoms. The diamides according to the invention are preferably used have a melting point above 100 C, are beständig- in hot water practically insoluble and resistant to attack by chemicals, in particular to hydrolysis by alkaline aqueous _solutions} These characteristics are necessary because the anti-foam formulations typically be used under hot alkaline aqueous environments.

Examples of diamides preferred according to the invention are N, N ¹ -Dioctadecylmalonamid, Ν, Ν'-Dioctadecylsuccinamid, Ν, Ν'-Diocta-

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decyladipamid, Ν, Ν'-Dioctadecylazelainid, N, N ^f -i) ioctadecylmaleamid, NjN'-Dioctadecylsebacamid and the corresponding NjN'Dihexadecylamides. and the like. These amides are prepared by heating the appropriate aliphatic amine with the appropriate dibasic carboxylic acid or its anhydride. A preferred diamide, NjN'-dioctadecyladipamide, is prepared by heating commercial grade stearylamine with adipic acid to 175 to 185 ° C. for several hours. Generally, the diamides are prepared by heating an alkylamine of 8 to 22 carbon atoms with a dibasic dibasic containing 3 to 10 carbon atoms Carboxylic acid or an anhydride thereof according to the equation

HO OH 2 RNH + HOOC - R ¹ - COOH -) 2 H ₂ O + RNCR '-CNR

HO OH

to 1! I.

2 RNH ₀ + R ¹ - * H _n O + RNCR ¹ -CNR 0 = C ^X C = 0

This shows that mixed amines or acids are also used can be and that the R group on a molecule a may have various chain lengths, although this is generally not preferred. A particularly preferred diamide is the Ν, Ν'-dioctadecyladipamide produced by heating stearylamine with adipic acid to around 175 to 185 ° C for several hours. By purging with nitrogen while heating

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the removal of the water of reaction is made easier and the product is prevented from becoming dark.

The silicone oil that can be used in the present invention may be a polysiloxane oil such as an alkyl, aryl, alicyclic or aralkylsiloxane or polysiloxane having a viscosity at 25 C of about 10 to about 3000 cSt. Examples AlkyIpοIysiloxanes with viscosities are preferred silicone oils at 25 ° C from about 40 to about 1000 cSt. About these alkylpolysiloxanes include dimethylpolysiloxane, diethylpolysiloxane, Dipropylpolysiloxane, methyletherpolysiloxane, dioctylpolysiloxane, dihexylpolysiloxane, methylpropylpolysiloxane, dibutylpolysiloxane, Didodecylpolysiloxane or the like with a viscosity at 25 C of about 10 to about 3000 cSt. Silicone oils according to the invention are particularly suitable are dimethylpolysiloxane, methyl hydrogenpolysiloxane and related off-the-shelf materials. Also preferred are the organopolysiloxane materials, such as * the hydroxyl end blocked dimethyl isiloxane fluids and benzene-soluble organopolysiloxane resins such as they are described in U.S. Patent 3,666,681. These organopolysiloxane materials are described as having hydroxyl Dime thy lpo Iy siloxane fluids closed at the ends with a viscosity at 25 C of at least 35 cSt and as benzene-soluble organopolysiloxane resins with (1) SiO units and (2) R 1, SiO,, units, where R is a monovalent Hydrocarbon radical with 1 to 6 carbon atoms means, the ratio of the SiO ^ units to the R SiO ,, units is within the range of 1.2 / 1 to 0.6 / 1. Specific examples of these silicone oils are in the U.S. Patent 3,666,681, cited above, and a

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such an oil is the commercial product X2-3O11.

The third essential component of the antifoam preparation according to the invention is the mineral oil, preferably a highly paraffinic mineral oil. A particularly preferred mineral oil is a under the trade name Citgo Sentry IO Oil distributed Citgo product. This oil has the following properties:

API density! Flash point focus

Viscosity at 38 ° G (100 ⁰ F)

Viscosity at 54 ° C (130 ⁰ F)

Viscosity at 99 ° C (210 ° F) viscosity index Pour point ASTM D1500 color Carbon residue Aniline point Neutralization number ASTM corrosion density

33.0 °.

Min. 193 ⁰ C (38O ° F) Min. 224 ° C (435 ° F)

100 to 110 SUS 65 SUS 40 SUS Min. 95 ■

Max. -17.8 ° G (0 ° F> Max. 2.0
Max. 0.01 %

102.5 ° C (217 ° F) Max. 0.05 Max. 1

0.115 g / cm ² (7.162 pounds / gallon)

A particularly high anti-foam activity for use in a brown material washer liquid is achieved in that the preparation according to the invention is used, which is a highly paraffinic Mineral oil, such as the Sentry 10 OiIj mentioned above.

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Each of the three essential components of the preparation according to the invention has so far been used either alone or in combination with other materials for foam control. For example, the Diamidß were used for foam control in steam boilers and the silicone oils and mineral oils were used in combination with other materials for the production of antifoam preparations. However, the special combination according to the invention was not previously known and it has been shown that it leads to surprising technical advantages. _R As indicated above, the activity (efficacy) of anti foam formulations is completely unpredictable and the fact that a certain material with success in an anti-foam preparation has been used, does not mean that this material is also effective in another formulation. The addition of useful antifoam additives often has an adverse effect on a particular preparation, so finding an effective antifoam preparation is a science in itself. For example, it has been found that although surfactants of the most varied types are often helpful in antifoam formulations, these surfactants generally reduce the effectiveness of the formulation according to the invention. The preparation according to the invention also becomes ineffective when one of the essential constituents is used in an amount outside the range specified above.

The antifoam preparations according to the invention can be produced by first adding a fatty amine with a diba-

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sisehen carboxylic acid or its anhydride, preferably with the introduction of nitrogen, is reacted to form the corresponding diamide. The diamide is preferably crushed to a fine particle size and then mixed with a portion of the mineral oil. This mixture is heated to _f the di ~ solubilize amide and the heated solution is then added to the remainder of the mineral oil, followed by cooling with stirring. A homogenizer is used to achieve a homogeneous mixture. The silicone oil can be added before or after the homogenization. In some cases, optimum effectiveness is achieved by heating the homogenized product (which contains the silicone oil) to 40 to 90 ° C. for 2 to 4 hours. The use of surface-active agents, surface spreading agents or other customary antifoam additives is not necessary in the preparations according to the invention.

The preparation of typical diamides for use in the preparations according to the invention is shown in the following examples 1 to 3 described.

example 1

Preparation of N ^ N'-dioctadecyl adigamide

A 37.9 liter (10 gallon) electrically heated reaction vessel The stainless steel was made with 13.98 kg (30.8 lbs) of stearylamine charged and the amine was heated to 175 to 185 C. A slow stream of nitrogen was injected into the molten amine. and in small portions over a 90 minute period 4.64 kg (10.2 lbs) of adipic acid were added. The Er-

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heating and bubbling nitrogen - was for 4.5 hours continued at 175 to 190 ° C. The Ν, Ν'-dioctyldecyladipamide formed was drained from the reaction vessel and allowed to cool in stainless steel dishes. The color was almost white and the melting point was 140 to 143 C. The infrared spectrum showed that no carboxylic acid was present, indicating that the conversion was complete.

Example 2

Manufacture of N ^ N'-dioctadecvlazelamide

A 21 reaction flask was filled with 540 grams of stearylamine and 188.2 grams Azelaic acid was charged and the mixture was heated to 150-170 ° C for 7 hours. It became a dark brown, waxy one Solid with a melting point of 108 to 111 ° C and the infrared spectrum indicated that all of the acid had reacted.

Example 3

A 2 liter reaction flask was filled with 540 g of stearylamine and 98.1 g Maleic anhydride was charged and the mixture was heated to 150-170 ° C for 7 hours. The infrared analysis showed that all of the maleic anhydride reacts with the diataid would have.

The production of antifoam preparations according to the invention using the diamides prepared in the above examples is illustrated in Examples 4 to 6 below.

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Example 4

A mixture of 25.0 g of NjN'-dioctadecyladipamide, which according to according to the method specified in claim 1, and 50.0 g of Sentry 10 Oil was added for 15 minutes heated to 160 C and the molten material was then quickly added to 417.5 g of stirred Sentry 10 Oil, the contained in a flask cooled by means of a water bath

ten was. This slurry was then put into a ball mill transferred and milled for 6.5 hours. A ratio of 1.5 g of silicone was added to the ground material 98.5 g of suspension, a commercial product from Dow (commercial name X2-3011) was added and the resulting preparation was then heated to 40 to 45 ° C. for 2 hours.

Example 5

Crude Ν, Ν'-dioctyldecylazelamide, prepared as in example 2, was ground in a mortar and pestle and 35 g of this was mixed with 455 g of Sentry IO Oil. This mixture was then milled in a ball mill for 12 hours to form a finely divided dxamid slurry.

By heating a mixture of 98 grams of the diamide slurry and 2 g of methyl polysoxloxane fluid having a viscosity An anti-foam preparation was produced at 95 to 100 ° C. of 50 cSt for a period of 4 hours.

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Example 6 _:

35 grams of crude N, N ¹ -dioctadecyl maleamide, prepared as in Example 3, was mixed with 455 grams of Sentry 10 Oil and the mixture was ball milled for 12 hours. Two antifoam preparations were produced from this finely divided diamide slurry. In the first product 2 g of dimethylpolysiloxane with a viscosity of 50 cSt were mixed with 98 g of the diamide slurry, in the second product 2 g of the silicone X2-3O11 were mixed with 98 g of the diamide slurry. Both mixtures were heated to 55 to 60 ° C. for 6 hours.

In the above examples is the production of antifoam preparations described on a laboratory scale. ' Antifoam preparations have also been made on a semi-industrial scale by heating of 6.80 kg (15 lbs) of N, Ni-dioctadecyl adipamide and 13.6 kg (30 lbs) Sentry 10 Oil to 170 ° G and then adding the hot molten material to 113 kg (250 lbs) Sentry 10 Oil, contained in an agitated, jacketed 379 l (100 gallon) reactor. The sentry 10 Oil was stirred and cooled while the molten amide / oil mixture was added. The chilled mixture was then passed twice through a tri-homo homogenizer for preparation a dispersion with finely divided diamide.

The diamide slurry was divided into different portions and treated with 1.0% and 1.5% of the silicone X2-3011 and with 1.5% dimethylpolysiloxane (50 cSt). Each of the three products was heated to 40 to 45 C for 2 hours and the anti-foam properties were compared with those who

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speaking, laboratory-scale products were achieved.

As noted above, a concentrated slurry of Diamide and Sentry IO Oil was made, but this time the concentration of Diamide was IQ % . After this viscous slurry had been homogenized in the Tri-Homo-Mill, the product was diluted with Sentry IO Oil and treated with the above mentioned silicones. After the end products had been heated to 40 to 45 ° C. for 2 hours, the effectiveness of the anti-foam preparations corresponded to that of the laboratory preparations.

The antifoam preparations according to the invention (defoamers) were tested by use in a black pulp mill liquid in a device consisting of a flask with an outlet at the bottom through which the black liquid was drawn off. The black liquid (black liquor) was fed into the flask through an atomizing nozzle returned. The liquid was held at 77 C (170 F) and circulated until the flask filled with foam was filled. At this point, 200 ppm of the antifoam formulation was added, with the black liquid was continued to cycle and the foam height was determined and recorded. There were measurements performed at the time when the foam height began to decrease, at the time when the foam was at its lowest Height, and at the time the foam height began to rise. Also the percentage of coincidence of the Foam was calculated. The results for the antifoam preparations (anti-skinning agents) of Examples 4 to 6 are

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indicated in the table below.

Tabel

Anti-foam accessories begin the maximum begin the Together riding Foam removal acceptance Foam to fall took took manifest Minutes Minutes percent Example 4 5 0.5 5 95 Example 5 45 1.5 7th 80 Example 6 65 4.5 > 5 70 Example 6 ' 20th 1.75 > 5 > 95

Whore thy lpolysiloxane

Silicone X2-3O11

The values in the table above explain the effectiveness of the antifoam preparations according to the invention and they also show that the effect lasted for a long time. A known antifoam preparation was prepared according to the process described in US Pat. No. 3,730,907. A 7% Äthylenbisstearamid, 1% Aerosol OT (disodium octylsulfosuccinate), 0.5 % Dimethylpoly oiloxane (50 cSt) and 91.5% Sentry IO Oil containing ■ was in a ball mill to a Hegman particle size of 5 to 5.5 ground. The slurry x-i was heated to 45 G for 6 hours and 60 G for 1 hour and then rapidly cooled.

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When tested as stated above, the foam started decrease within 30 seconds and after 1.5 minutes the foam decrease was 80%. After 2 minutes the foam took off however again and after 3 minutes the foam decrease was only 35%.

As stated above, the antifoam preparations according to the invention need not to contain any surfactants, surface spreading agents or other additives. As below is shown, such additives can even be disadvantageous for the effectiveness of the anti-foam preparations according to the invention be, so that the antifoam preparations according to the invention preferably only the three essential components Contains diamide, silicone and mineral oil.

It became the influence of surfactants on the defoaming properties investigated experimentally. A mixture of 35 g of NjN'-dioctadecyl adipamide, 10 g of dimethylpolysiloxane (50 cSt) and 455 g of Sentry 10 Oil was ball milled for 12 hours. Part of the ground product was made Heated to 95 to 100 C for 3 hours. In the foam test the foam decreased by 50% within 55 seconds and did not begin to rise again after 4.5 minutes. When the milled diamide slurry with 1% sodium lauryl sulfate and heated to 95 to 100 C for 3 hours, took when the product obtained in this way was used, the foam formation did not cease, but rather the foam emerged from the flask after 2.5 minutes the end. When polyethylene glycol 400 monoleate in an amount of 1% was used instead of the sodium lauryl sulfate,

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a slight decrease in foam was observed after 1.75 minutes, but the foam increased after 3 minutes again to.

The above experiments show that the presence of surface-active agents in the antifoam preparations according to the invention is actually disadvantageous for the defoaming properties. As indicated above, the antifoam formulations of the present invention are particularly effective in treating pulp mill fluids. The preferred manner of foam control in a pulp mill is to continuously add the anti-foam composition by means of a dosage pump launch or the like. In such an amount that effectively prevents formation of foam during normal mill operating conditions. The continuous addition under normal conditions is preferably supported by the addition of slag during disturbed or abnormal conditions.

The antifoam preparations according to the invention preferably exist from 2 to 20% of one of the diamides given above, 0.5 to 5.0% silicone oil and the remainder from a highly paraffinic one Mineral oil.

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Claims (17)

Claims 1. Antifoam preparation, characterized in that it essentially consists of (A) 2 to 20% by weight of a diamide of the general formula HO OH r ti ti ι RNCR ¹ -CNR where R is an alkyl group having 8 to 22 carbon atoms and R ^{1 is} a saturated or unsaturated alkylene group having 1 to 8 carbon atoms, (B) 0.5 to 5% by weight of a silicone oil and (C) 75 to 97.5% by weight of a mineral oil. 2. Preparation according to claim 1, characterized in that it is an organopolysiloxane from the group of silicone oil Dimethylpolysiloxane fluid blocked with hydroxyl at the ends and having a viscosity at 25 C of at least 35 cSt and which contains benzene-soluble organopolysiloxane resins which essentially consist of (1) SiO "units and (2) R "SiO," - units, in which R is a monovalent hydrocarbon rest with 1 to 6 carbon atoms, and in which. the ratio of the SiO_ units to the R ^ SiO,, units • is within the range from 1.2 / 1 to 0.6 / 1. 509819/0639 3. Preparation according to claim 1, characterized in that it contains diniechylpolysiloxane as silicone oil. 4. Preparation according to at least one of claims 1 to 3, characterized marked that it is a highly paraffinic mineral oil with a viscosity of 38 G (100 F) of Contains 100 to 110 SÜS. 5. Preparation according to at least one of claims 1 to 4, characterized characterized in that they are called Diaraid N, N'-dioctadecyladipamide contains. 6. Preparation according to at least one of claims 1 to 4, characterized characterized in that they are called diamide Ν, Ν'-dioctadecylazelamide contains. 7. Preparation according to at least one of claims 1 to 4, characterized characterized in that they are called diamide Ν, Ν'-dioctadecyl maleamide contains. 8. A preparation according to claim 1, characterized in that they 5 wt .-% of Dioctadecyladipamid to 1.0 wt -.% Of a silicone oil and 94.0 wt .-% of a paraffinic mineral oil having a viscosity at 38 100 ° F (100 ° F) from 100 to 110 degrees Celsius. 9. Preparation according to claim 1, characterized in that they 7o 5 parts by weight of Dioctadecyladipamid to 1.5 wt .-% of a silicone oil and 93.5 wt .-% of a paraffinic mineral oil having a viscosity at 38 ° G (100 ° F) consists of 100 to 110 SUS. 509819/06 39 10. Preparation according to claim 9, characterized in that it contains dimethylpolysiloxane as the silicone oil. 11. Preparation according to claim 9, characterized in that it contains the commercial product X2-3011 as silicone oil. 12. Preparation according to claim 10, characterized in that it is for 2 to 4 hours at a temperature of 40 to 90 ° C has been heated. 13. Use the antifoam preparation after at least any one of claims 1 to 12 in a method for controlling foam formation in an aqueous system • to which the antifoam preparation is added to the aqueous system added in an amount sufficient to control foam formation. 14. Use of the antifoam preparation according to at least one of claims 1 to 12 in a pulp mill liquid for the purpose specified in claim 13. 15. Use of the antifoam preparation according to at least one of claims 1 to 12 in a black liquid for the purpose specified in claim 14. 16. Use of the antifoam preparation according to at least one of claims 1 to 12 in a brown material washer liquid for the purpose specified in claim 14. 509 819/0639 17. Use of the antifoam preparation after at least one of claims 1 to 12 to that specified in claim 14- Purpose, taking the antifoam preparation continuously is added to the liquid. ? 509819/0639