WO1993009861A1

WO1993009861A1 - Anti-foaming agents

Info

Publication number: WO1993009861A1
Application number: PCT/EP1992/002581
Authority: WO
Inventors: Günther DEMMERING; Karl-Heinz Schmid; Michael KÖHLER; Detlev Stanislowski
Original assignee: Henkel Kommanditgesellschaft Auf Aktien
Priority date: 1991-11-19
Filing date: 1992-11-10
Publication date: 1993-05-27
Also published as: JPH07501008A; DE4138001A1; EP0620753A1

Abstract

Described are anti-foaming agents containing fatty alcohols with 16 to 24 carbon atoms in a particular composition, higher (wax) esters and, optionally, ketones of fatty acids. Such agents are stable to the action of chlorine and are suitable for foam reduction in cleaning agents for hard surfaces, paints and varnishes as well as effluents from sewage-treatment plants and industrial processes such as metalworking or paper manufacture.

Description

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Field of the Invention

The invention relates to anti-foaming agents containing fatty alcohols with 16 to 24 carbon atoms, wax esters and, if appropriate, fatty ketones and their use as additives for cleaning agents, in the production of paints and varnishes and in the wastewater treatment of sewage treatment plants and from technical processes such. B. metalworking or papermaking.

State of the art

The display development associated with the use of surface-active substances poses a serious problem for a large number of technical processes. In machine household cleaning of dishes, but also in the industrial cleaning of beer and milk bottles, powder or liquid, for example, become Alkaline cleaning agents also use the active chlorine or active oxygen compounds in addition to surfactants, builders, alkali metal silicates, carbonates and / or hydroxides contain. To prevent excessive foaming, an anti-foaming agent is usually added to these agents.

Also in the production of paints and varnishes, for example water-based paints, the tendency of the water-dilutable binders to increase foam formation is observed. Foam can already arise here when the recipe components are mixed, i.e. H. when the paint is rubbed in by stirring in air, and the result is that the respective systems can be filled and operated only with a fraction of the available volume. The use of defoamers and deaerators is also urgently required in this area [Goldschmidt. Infoπα. 66, 9 (1989)].

Another field in which anti-foaming agents are used is the wastewater treatment of sewage treatment plants. In the aeration process, air is blown into the wastewater, for example, which ensures intimate mixing and the meeting of the dirt particles with the microorganisms [ChiuZ. 25, 87 (1991)]. The resulting foam is protein foam in many cases and therefore particularly resistant. Instead of sedimentation, there is an undesired fixing of the solids in and on the foam lamellae, which makes it difficult to separate the sewage sludge.

In the past there has been no lack of attempts to provide appropriate anti-foaming agents for the complex field of foam regulation.

For example, it is known from German Offenlegungsschriften DE-OS 14 67 613 and DE-OS 22 42 541 that ketones are suitable as foam inhibitors in soap-containing detergents. European patent application EP 0 324 339 A2 also discloses dispersions which contain fatty ketones as active substances and mineral oils or Guerbet alcohols as carrier liquids. However, the defoaming effect of such systems is not sufficient for many areas of application.

The object of the invention was therefore to develop new anti-foaming agents which are free from the disadvantages described.

Description of the invention

The invention relates to antifoams containing

a) fatty alcohols of the formula (I)

Ri-OH ( ^I )

in which R ^{1 represents} a saturated, linear, optionally hydroxyl-substituted alkyl radical with the following C chain distribution:

Cl8 32 to 88% by weight C20 2 to 43% by weight

C22 4 to 52% by weight C22 0 to 15% by weight,

b) wax esters of the formula (II) R ² CO-OR ³ (II)

in the

R- ^ CO for an optionally hydroxy-substituted acyl radical having 16 to 24 carbon atoms and 0 or 1 double bond and

R ^{3 represents} an optionally hydroxy-substituted aliphatic hydrocarbon radical with 16 to 24 carbon atoms and 0 or 1 double bond

and if necessary

c) fat ketones of the formula (III),

R4_ _C0 _R5 (III)

in which R ^ and R5 independently of one another represent alkyl radicals having 15 to 24 carbon atoms.

Surprisingly, it was found that by adding wax esters to long-chain fatty alcohols, their softening point can advantageously be increased and that the products are outstandingly suitable as chlorine-stable defoamers for a large number of technical applications. The invention includes the finding that the application properties of the antifoam agents can be increased unexpectedly by adding small amounts of fat ketones. Furthermore, the agents are characterized by easy biodegradability, which meets the general demand for products that are as environmentally compatible as possible.

Fatty alcohols of the formula (I) which can be considered as component a) have 16 to 24 carbon atoms. Typical examples are cetyl alcohol, stearyl alcohol, 12-hydroxystearyl alcohol, arachyl alcohol and behenyl alcohol.

As usual in fat chemistry, the fatty alcohols can also be found in

Form technical cuts are used. Suitable starting materials for this purpose are, for example, methyl esters based on rape oil rich in erucic acid, peanut oil, castor oil, medofoam oil, beef tallow or fish oil which are subjected to high pressure hydrogenation. In this case, not only is there a reduction of the ester group to the hydroxyl function, but at the same time there is also extensive saturation of double bonds contained in the fat chain. Antifoam agents with particularly advantageous technical properties contain fatty alcohols of the C number range mentioned which have iodine numbers below 10, preferably 0.1 to 5.

Fatty alcohol mixtures which are particularly suitable as component a) for the preparation of the antifoam agents according to the invention can be characterized by the following C chain distribution:

Cι ₈ 0 to 6 wt .-%

Cl8 35 to 71% by weight

C20 4 to 33% by weight

C22 20 to 52% by weight C ₂ 2 0 to 9% by weight Fatty alcohols or fatty alcohol mixtures are particularly preferred which have a hydroxyl number of 180 to 200, a softening point of 50 to 60 ° C. and are obtained as a wake in the distillation of fatty alcohols based on beef tallow or rapeseed oil.

Wax esters of the formula (II) which can be used as component b) are to be understood as the esters of C1-C24-fatty acids with C * Lg-C24-fatty alcohols. Typical examples are the esters of palmitic acid, stearic acid, 12-hydroxystearic acid, arachic acid and behenic acid with cetyl alcohol, stearyl alcohol, 12-hydroxystearyl alcohol, arachyl alcohol and behenyl alcohol. The wax esters can also contain small amounts of unsaturated components, both in the fatty acid and in the fatty alcohol component. Wax esters are preferred which have an iodine number less than 10, preferably from 0.1 to 5. Typical examples are stearyl stearate, stearyl behenate and behenyl behenate. Pure or technical fatty acids and corresponding fatty alcohols can be used to manufacture the products, which are esterified in a manner known per se. In a particular embodiment of the invention, technical wax esters are used which are obtained as a residue from the hydrogenation of 15---. C24-fatty acid methyl esters to the corresponding fatty alcohols.

Fat ketones of the formula (III), which are considered as optional component c), are known substances which can be obtained by the relevant methods of preparative organic chemistry. For their production, one starts from, for example, fatty acid magnesium salts, which at Temperatures above 300 ° C are pyrolyzed with elimination of CO2 and water [DE-OS 25 53 900]. Typical examples are fatty ketones which are produced by pyrolysis of the magnesium salts of palmitic acid, stearic acid, arachic acid, behenic acid and their technical mixtures, for example cigig tallow fatty acid. The use of stearone (pentatriacontanon-18) is preferred.

The antifoam agents can typically contain the fatty alcohols in amounts of 80 to 98, preferably 90 to 95% by weight, the wax esters in amounts of 2 to 20, preferably 5 to 12% by weight and the fatty ketones in amounts of 0.1 to 10 , preferably 2 to 8 wt .-% contain. The stated concentration data are in each case based on the sum of components a)> b) and c).

The antifoam agents according to the invention can be used in substance. In a preferred embodiment of the invention, however, dispersions of components a) and b) and optionally c) are used in carrier oils, the content of carrier oil - based on the composition - being 10 to 95, preferably 50 to 90.

Typical carrier oils are, for example, mineral oils, paraffin oils, dialkyl ethers, in particular di-n-octyl ether, and Guerbet alcohols with 16 to 32 carbon atoms.

Furthermore, the antifoam agents can contain minor amounts of stabilizers, for example alkaline earth and / or aluminum soaps, hydrophobized silicas, phyllosilicates, tackifiers, in particular polyacrylates and contain nonionic surfactants, for example alkyl glucosides or mixed ethers.

If the agents only contain components a), b) and, if appropriate, c), it is advisable during production to heat the substances with stirring to a temperature above the melting point of the component with the highest melting point and then to solidify the melt let. To prepare dispersions of components a), b) and optionally c) in carrier oils, stirring can also be carried out at room temperature; a chemical reaction does not take place in either of the two cases.

The anti-foaming agents according to the invention also show a foam-pressing or foam-regulating effect at higher temperatures and particularly stable foams. They are stable against active chlorine and active oxygen and are also easily biodegradable.

Another object of the invention therefore relates to the use of the anti-foaming agents according to the invention as additives to agents for cleaning hard surfaces. This includes, for example, means for machine dishwashing, automatic bottle cleaning, CIP (cleaning-in-place) cleaning and degreasing of metal surfaces in the body shop. The anti-foaming agent can detergents ^"in amounts of 0.1 to 10, preferably 1 to 5 wt .-% - are added - based on the detergent. Furthermore, the antifoam agents according to the invention are also suitable as defoamers or deaerators in the production of paints and varnishes and as defoamers in the wastewater treatment of sewage treatment plants and from technical processes such as metalworking or paper production.

The following examples are intended to explain the subject matter of the invention in more detail without restricting it.

Examples

J. Recipes used

Tab. 1: Recipes

Percentages as% by weight

Legend:

Carrier oil mineral oil from Pioneer, No. 4556

Fatty alcohol mixture

Lorol ( ^R ) C16: Technical Cetyl Alcohol Lorol ( ^R ) C18: Technical Stearyl Alcohol Stenol ( ^R) 1822: Technical Behenyl Alcohol Sales Products by Henkel KGaA

Wax ester: Technical stearyl stearate from the residue of the tallow fatty acid methyl ester hydrogenation

Hydroxyl number 93 saponification number 45 iodine number 5 softening point 50 ° C. XX. Application-technical examples

Examples 1 to 5:

500 ml of a 2% strength by weight solution of dodecylbenzenesulfonate sodium salt in water (Maranil ^(R ) A55, approx. 50% strength by weight, from Henkel) were placed in a double-walled measuring cylinder of 2000 ml capacity KGaA) filled. With the help of a laboratory peristaltic pump (dead volume: 100 ml), the solution was sucked from the bottom of the measuring cylinder using a glass tube. The liquid was returned via a second tube, the lower end of which ended at the level of the upper edge of the measuring cylinder. The solution was pumped around at a rate of 4 l / min and fell back into the measuring cylinder with foaming. After a volume of 2000 ml (400 ml of liquid + 1600 ml of foam) had been reached, 1.5 ml of anti-foaming agent (formulations A to E) were added to the foam column. The volumes which had formed from foam and liquid were read off at regular intervals over a period of 0.5 to 30 minutes. The results of the foam measurements at 20 ° C are summarized in Table 2.

Tab. 2: Foam measurements

) Volume = liquid + foam

Claims

1. Containing antifoam

a) fatty alcohols of the formula (I)

R --— OH (I)

in which R * - stands for a saturated, linear, optionally hydroxy-substituted alkyl radical with the following C chain distribution:

b) wax esters of the formula (II),

R ² CO-OR ³ (H)

in the

R2C0 for an optionally hydroxyl-substituted acyl radical with 16 to 24 carbon atoms and 0 or 1 double bond and

R stands for an optionally hydroxy-substituted aliphatic hydrocarbon radical with 16 to 24 carbon atoms and 0 or 1 double bond and if necessary

c) fat ketones of the formula (III),

R -CO-R ⁵ (HI)

in which R ⁴ and R - independently of one another represent alkyl radicals having 15 to 24 carbon atoms.

2. Anti-foaming agent according to claim 1, characterized gekennzeich¬ net that the fatty alcohols of formula (I) have a hydroxyl number of 180 to 200.

3. Anti-foam agent according to claim 1, characterized in that the fatty alcohols of the formula (I) have a softening point of 50 to 60 ° C.

4. Antifoam agent according to at least one of claims 1 to 3, characterized in that the fatty alcohols of the formula (I) are present in an amount of 80 to 98% by weight, based on the sum of components a), b) and c).

5. Anti-foaming agent according to at least one of claims 1 to 4, characterized in that the wax esters of the formula (II) are present in an amount of 2 to 20% by weight, based on the sum of components a), b) and c).

6. Antifoam agent according to at least one of claims 1 to 5, characterized in that the fatty ketones of the formula (III) to 0.1 to 10 wt .-% - based on the sum of components a), b) and c) - contain are.

7. Antifoam agent according to at least one of claims 1 to 6, characterized in that it has a content of carrier oils.

8. antifoam agent according to at least one of claims 1 to 7, characterized in that they have a content of stabilizers.

9. Use of anti-foaming agents according to claims 1 to 8 as additives to agents for cleaning hard surfaces.

10. Use according to claim 9, characterized in that the anti-foaming agents are added to the cleaning agents in amounts of 0.1 to 10% by weight, based on the cleaning agents.

11. Use of anti-foaming agents according to claims 1 to 10 as defoamers and deaerators in the manufacture of paints and varnishes.

12. Use of anti-foaming agents according to claims 1 to 11 as defoamers in the wastewater treatment of sewage treatment plants.