DE102005036748A1 - Use of siloxane copolymer (prepared by reacting aliphatic compound with organosiloxane; reacting obtained siloxanecopolymer with dialkenyl siloxanepolymer followed by equilibrating) as antifoamer in e.g. textile dyeing - Google Patents

Abstract

Use of siloxane copolymer (A) (as siloxanecopolymer alkenyl group is obtained by reacting at least three aliphatic double bond containing compound (1) with organosiloxane (2); reacting the obtained Si-bonded hydrogen atom containing hydrocarbon siloxanecopolymer with alpha , omega dialkenyl siloxanepolymer (4); optionally equilibrating the obtained siloxanecopolymer (containing alkenyl group) with organopolysiloxane (5)) as antifoamer. Use of siloxane copolymer (A) (as siloxane copolymer alkenyl group exhibiting siloxane copolymer is prepared by reacting at least three aliphatic double bond containing compound (1) of formula R2>(CR3>=CH2)x with organosiloxane (2) (having terminal Si-bonded hydrogen atom) in the presence of catalyst (3), which promotes Si-bonded hydrogen at aliphatic double bond, where the ratio of Si-bonded hydrogen in the organosiloxane to aliphatic double bond in organic compound (1) is 1.3-10 (preferably 1.5-5); reacting the obtained Si-bonded hydrogen atom (exhibiting hydrocarbon siloxane copolymer) with alpha , omega dialkenyl siloxane polymer (4) in the presence of catalyst (3), which promotes Si-bonded hydrogen at aliphatic double bond, where the ratio of aliphatic bond in the alpha , omega dialkenyl siloxane polymer (4) to Si-bond hydrogen in the siloxanecopolymer is 1.2-10 (preferably 1.5-5); optionally equilibrating the obtained siloxanecopolymer (containing alkenyl group) with organopolysiloxane (5) (linear, terminal triorganosiloxy group containing organopolysiloxane, linear, terminal hydroxyl group containing organopolysiloxane, branched, optionally hydroxyl group containing organopolysiloxane, cyclic organopolysiloxane and copolymers of diorganosiloxane- and monoorganosiloxane units)) as antifoamers. R2>trivalent or tetravalent 1-25C hydrocarbon containing heteroatom (O, Si or Ti); R3>H or 1-6C alkyl; and x : 3-4. Independent claims are also included for: (1) an antifoaming formulation (II): comprising 100 wt.parts of (A), 0.1-30 wt.parts of at least one filler and 0-900 wt.parts of at least one polyorganosiloxane (polyorganosiloxane of formula (Ra(R5>O)bSiO(4-a-b)/2) and/or silicon resins of formula ((R3SiO)1/2) or (SiO4/2)); and (2) an emulsion (III) of antifoaming formulation comprising (II), emulsifier and water. R5>H or univalent or monovalent, optionally substituted, optionally saturated 1-30C hydrocarbon; and a, b : 0-3 (preferably b is of an average value of less than 0.5) (where the sum of a+b is less than or equal to 3 and an average value of 1.8-2.4).

Description

The The invention relates to the use of siloxane polymers as defoamers, and defoamer and their use in aqueous Surfactant.

In many liquid, especially aqueous Systems that are as desired or unwanted components surfactants Compounds can contain Foaming problems occur when these systems are in more or less intense contact with gaseous substances, For example, when fumigating wastewater, during intensive stirring of Liquids, during distillation, washing or dyeing processes or during filling operations.

The fight This foam can be obtained mechanically or by addition of defoamers respectively. This siloxane-based defoamers have particular proven.

Defoamers based on siloxanes, for example, after DE 1519987 A by heating hydrophilic silica in polydimethylsiloxanes. By using basic catalysts, the effectiveness of such defoamers can be improved ( DE 1769940 A ). An alternative is the distribution of hydrophobized silica in a polydimethylsiloxane, e.g. B. accordingly DE 29 25 722 A , However, the effectiveness of the defoamers obtained is still in need of improvement. So describes US 4 145 308 for example, an antifoam preparation which, in addition to a polydiorganosiloxane and silica, also contains a copolymer of (CH ₃ ) ₃ SiO _1/2 and SiO _{2 building} blocks. Copolymers of (CH ₃ ) ₃ SiO _1/2 and SiO _{2 building} blocks should also be advantageous in combination with siloxanes carrying long alkyl groups ( EP 301531 A ).

The use of partly cross-linked rubber-like polydimethylsiloxanes to increase the antifoaming effect has been known for a long time ( US 2632736 ). The preparation of such products can be carried out, for example, by free radical crosslinking of polydimethylsiloxane (eg DE 3805661 A . EP 273448 A ). However, these methods are very unspecific and provide poorly manageable products.

EP 163 541 A teaches the preparation of a defoamer with improved long-term effect by catalytic reaction of trimethylsiloxy-terminated polydimethylsiloxanes, hydroxyl-terminated polydimethylsiloxanes, an alkoxysilane or a siloxane or a copolymer of (CH ₃ ) ₃ SiO _1/2 and SiO _{2 building} blocks and a filler in the presence of a catalyst. As catalysts, bases or organometallic compounds are mentioned.

The preparation of a defoamer by mixing hydrophobic silica with a polysiloxane by alkaline catalyzed reaction at temperatures above 120 ° C from trimethylsilyl-terminated polydimethylsiloxanes, hydroxyl-terminated polydimethylsiloxanes and a copolymer of (CH ₃ ) ₃ SiO _1/2 - and SiO _{2 building} blocks was prepared describes EP 217 501 A , This is intended to improve the effectiveness of the defoamer at high concentrations of anionic surfactants.

By addition of cross-linked siloxane ( EP 434060 A ) or gelation of the antifoam agent after emulsion preparation ( EP 499364 A ) a further increase in effect is possible. Such crosslinked and branched structures are also possible by reaction of vinyl-containing siloxanes with Si-H functional siloxanes ( DE 4444175 A . EP 516109 A ).

In DE 10255649 A Siloxane-based antifoams are described which contain as an additive a branched polyether-polysiloxane copolymer. The added copolymer is a surfactant.

The However, antifoam formulations prepared according to the prior art have in strong foaming surfactant-rich systems are not always sufficiently effective and, or are due to the high viscosity or the achieved degree of crosslinking difficult to handle.

The object was to provide defoamers based on siloxanes, which show improved effectiveness, in particular in surfactant-rich, strongly foaming media, but are nevertheless easy are manageable.

wobei R² einen dreiwertigen oder vierwertigen Kohlenwasserstoffrest mit vorzugsweise 1 bis 25 Kohlenstoffatomen je Rest, der ein oder mehrere von einander separate Heteroatome ausgewählt aus der Gruppe von Sauerstoff, Silizium und Titan enthalten kann,
R³ ein Wasserstoffatom oder einen Alkylrest mit 1 bis 6 Kohlenstoffatomen je Rest und
x 3 oder 4, bedeutet,
mit einem Organosiloxan (2) mit endständigen Si-gebundenen Wasserstoffatomen
in Gegenwart von die Anlagerung von Si-gebundenem Wasserstoff an aliphatische Doppelbindung förderndem Katalysator (3) umgesetzt wird,
wobei das eingesetzte Verhältnis von Si-gebundenem Wasserstoff im Organosiloxan (2) zu aliphatischer Doppelbindung in organischer Verbindung (1) 1,3 bis 10, vorzugsweise 1,5 bis 5 beträgt,
in einem zweiten Schritt
die so erhaltenen, Si-gebundene Wasserstoffatome aufweisenden Kohlenwasserstoff-Siloxancopolymere
mit α,ω-Dialkenylsiloxanpolymer (4)
in Gegenwart von die Anlagerung von Si-gebundenem Wasserstoff an aliphatische Doppelbindung förderndem Katalysator (3) umgesetzt werden,
wobei das eingesetzte Verhältnis von aliphatischer Doppelbindung im α,ω-Dialkenylsiloxanpolymer (4) zu Si-gebundenem Wasserstoff in den Siloxancopolymeren 1,2 bis 10 vorzugsweise 1,5 bis 5 beträgt,
und gegebenenfalls in einem dritten Schritt
die so erhaltenen Alkenylgruppen aufweisenden Siloxancopolymere mit Organopolysiloxan (5),
ausgewählt aus der Gruppe bestehend aus linearen, endständige Triorganosiloxygruppen aufweisenden Organopolysiloxanen, linearen, endständige Hydroxylgruppen aufweisenden Organopolysiloxanen, verzweigten, gegebenenfalls Hydroxylgruppen aufweisenden Organopolysiloxanen, cyclischen Organopolysiloxanen und Mischpolymerisaten aus Diorganosiloxan- und Monoorganosiloxaneinheiten, equilibriert werden, eingesetzt werden.The invention relates to the use of siloxane copolymers as defoamers, characterized in that siloxane copolymers having alkenyl groups can be prepared as siloxane copolymers by, in a first step, a compound (1) of the general formula having at least three aliphatic double bonds

wherein R ^{2 is} a trivalent or tetravalent hydrocarbon radical preferably having 1 to 25 carbon atoms per radical, which may contain one or more separate heteroatoms selected from the group of oxygen, silicon and titanium,
R ^{3 is} a hydrogen atom or an alkyl radical having 1 to 6 carbon atoms per radical and
x 3 or 4, means
with an organosiloxane (2) having terminal Si-bonded hydrogen atoms
in the presence of the addition of Si-bonded hydrogen to aliphatic double bond promoting catalyst (3) is reacted,
wherein the ratio of Si-bonded hydrogen in organosiloxane (2) to aliphatic double bond in organic compound (1) is 1.3 to 10, preferably 1.5 to 5,
in a second step
the thus obtained Si-bonded hydrogen atoms containing hydrocarbon siloxane copolymers
with α, ω-dialkenylsiloxane polymer (4)
in the presence of the addition of Si-bonded hydrogen to aliphatic double bond promoting catalyst (3) are reacted,
wherein the ratio of aliphatic double bond in the α, ω-dialkenylsiloxane polymer (4) to Si-bonded hydrogen in the siloxane copolymers is preferably from 1.2 to 10, preferably from 1.5 to 5,
and optionally in a third step
the resulting alkenyl-containing siloxane copolymers with organopolysiloxane (5),
selected from the group consisting of linear, terminal triorganosiloxy-containing organopolysiloxanes, linear, terminal hydroxyl-containing organopolysiloxanes, branched, optionally hydroxyl-containing organopolysiloxanes, cyclic organopolysiloxanes and copolymers of diorganosiloxane and monoorganosiloxane units, equilibrated are used.

The Alkenyl-containing siloxane copolymers and their preparation are described in US-A 6,265,497 and US-A 6,265,497 (incorporated by reference) therefore to the content of the disclosure of the application.

In the alkenyl groups according to the invention having siloxane copolymers, the siloxane blocks are preferably linked to one another via hydrocarbon bridges connected, resulting in a hydrocarbon-siloxane block structure results.

The alkenyl groups according to the invention having siloxane copolymers preferably have a viscosity of 0.05 up to 500 000 Pa · s at 25 ° C, preferably 0.1 to 100,000 Pa · s at 25 ° C, more preferably 0.2 to 10,000 Pa · s at 25 ° C.

A preferred embodiment for very viscous siloxane copolymers, the preparation of the alkenyl groups according to the invention having siloxane copolymers in solvents, preferably hydrocarbons having a boiling point preferably below 150 ° C, such as toluene, xylene, n-hexane, n-octane, i-octane and gasoline fractions, in a concentration of preferably 20-60 Wt .-% siloxane content, with higher or lower concentrations within the scope of the present invention are included.

in the first method step may be a kind of compound (1) or different Types of compound (1) are used.

The compound (1) used in the first process step is preferably those in which R ^{2 is} a trivalent hydrocarbon radical having preferably 1 to 25 carbon atoms per radical and x is a value of 3.

The Organosiloxane (2) used in the first process step preferably contains two Si-bonded hydrogen atoms per molecule.

in the first method step, a kind of organosiloxanes (2) or various types of organosiloxane (2) are used.

As organosiloxane (2), in the first process step, preference is given to those of the general formula HR ₂ SiO (SiR ₂ O) _n SiR ₂ H (II), wherein R preferably the same or different, optionally halogenated hydrocarbon radicals having 1 to 6 carbon atoms per radical and
n is 0 or an integer, particularly preferably an integer from 7 to 2000, where all integers between 0 and 2000 are to be considered explicit,
used.

wobei R die oben dafür angegebene Bedeutung hat,
R¹ einen zweiwertigen Kohlenwasserstoffrest, bevorzugt einen Alkylenrest, mit vorzugsweise 2 bis 10 Kohlenstoffatomen je Rest bedeutet oder einen zweiwertigen Silan- oder Siloxanrest, vorzugsweise mit vorzugsweise 2 bis 10 Si-Einheiten,
R⁴ ein endständig olefinisch ungesättigter Rest mit 2 bis 10 Kohlenstoffatomen ist,
l gleich oder verschieden sein kann und 0 oder 1 ist, durchschnittlich 0,7 bis 1,0 ist,
m gleich 0 oder eine ganze Zahl von 1 bis 10, vorzugsweise 0 ist,
und k gleich 0 oder eine ganze Zahl von 1 bis 1000, vorzugsweise 20 bis 1000, bevorzugt 50 bis 500 ist,
verwendet.As the α, ω-dialkenylsiloxane polymer (4), in the second process step, it is preferable that the general formula

where R has the meaning given above,
R ^{1 is} a divalent hydrocarbon radical, preferably an alkylene radical, preferably having 2 to 10 carbon atoms per radical or a divalent silane or siloxane radical, preferably having preferably 2 to 10 Si units,
R ^{4 is} a terminal olefinically unsaturated radical having 2 to 10 carbon atoms,
l may be the same or different and is 0 or 1, on average 0.7 to 1.0,
m is 0 or an integer from 1 to 10, preferably 0,
and k is 0 or an integer from 1 to 1000, preferably 20 to 1000, preferably 50 to 500,
used.

It In the second method step, a type of α, ω-dialkenylsiloxane polymer (4) can be used. or various types of α, ω-dialkenylsiloxane polymer (4) are used.

Examples for leftovers R are preferably alkyl radicals, such as the methyl, ethyl, n-propyl, iso-propyl, 1-n-butyl, 2-n-butyl-iso-butyl, tert-butyl, n-amyl and the n-hexyl radical. The methyl radical is preferred.

Examples for halogenated Radicals R are haloalkyl radicals, such as preferably the 3,3,3-trifluoro-n-propyl radical, the 2,2,2,2 ', 2', 2'-hexafluoroisopropyl radical, the heptafluoroisopropyl radical.

Examples of alkyl radicals R ³ are preferably the methyl, ethyl, n-propyl, iso-propyl, 1-n-butyl, 2-n-butyl, iso-butyl, tert-butyl, n Pentyl, iso-pentyl, neo-pentyl, tert-pentyl and hexyl, such as the n-hexyl. Preferably, R ^{3 is} a hydrogen atom.

Examples of radicals R ⁴ are alkenyl radicals, such as the vinyl, 5-hexenyl, cyclohexenyl, 1-propenyl, allyl, 3-butenyl, 4-pentenyl and 7-octenyl radical, and alkynyl radicals, such as the ethynyl, propargyl - and 1-propynyl. The radical R ⁴ is preferably alkenyl radicals, with the vinyl radical being particularly preferred.

Examples of compounds (1) with which the alkenyl-containing siloxane copolymers according to the invention can be prepared are
1,2,4-trivinylcyclohexane,
1,3,5-Trivinylcyclohexane,
3,5-dimethyl-4-vinyl-1,6-heptadiene,
1,2,3,4-tetra vinylcyclobutane,
methyltrivinylsilane,
tetravinylsilane,
1,1,2,2-tetraallyloxyethane,
with 1,2,4-trivinylcyclohexane being preferred.

wobei der Rest der Formel

bevorzugt ist.Examples of the radical R ² are therefore preferably those of the formula

where the rest of the formula

is preferred.

Examples of α, ω-dialkenylsiloxane polymer (4) with which the inventive alkenyl-containing siloxane copolymers can be prepared are
α, ω-divinylpolydimethylsiloxane,
α, ω-Diallylpolydimethylsiloxan,
α, ω-Dihexenylpolydimethylsiloxan,
α, ω-Dioctenylpolydimethylsiloxan,
and polyaddition products of organosiloxane (2) and dienes such as
1,5-hexadiene,
1,7-octadiene,
1,9-decadiene,
1,11-dodecadiene,
1,13-tetradecadiene,
2,5-dimethyl-1,5-hexadiene,
3,5-dimethyl-1,6-heptadiene,
1,3-divinylbenzene,
1,4-divinylbenzene, 1,3-diisopropenylbenzene,
divinyldimethyl,
1,3-divinyl-1,1,3,3-tetramethyldisiloxane,
wherein α, ω-divinylpolydimethylsiloxanes and α, ω-dihexenylpolydimethylsiloxanes are preferred.

-CH₂CH₂-C₆H₄-CH₂CH₂ wobei der Rest der Formel -(CH₂)₆ bevorzugt ist.Examples of radicals R ¹ are those of the formula - (CH ₂ ) ₆ - (CH ₂ ) ₈ - (CH ₂ ) ₁₀ - (CH ₂ ) ₁₂ - - (CH ₂ ) ₁₄ -

-CH ₂ CH ₂ -C ₆ H ₄ -CH ₂ CH ₂ where the rest of the formula - (CH ₂ ) ₆ is preferred.

organosiloxane (2) is used in the first step in such quantities, that the ratio of Si-bonded hydrogen in organosiloxane (2) to aliphatic Double bond in compound (1) 1.3 to 10, preferably 1.5 to 4.0, more preferably 1.8 to 3.0.

There Organosiloxane (2) in excess is used, therefore, preferably react in the first process step all aliphatic double bonds in the compound (1) from, and Siloxane copolymers containing the Si-bonded hydrogen atoms are obtained exhibit.

The first process step, the reaction of compound (1), such as 1,2,4-trivinylcyclohexane, with organosiloxane (2), such as 1,3-dihydrogen-1,1,3,3-tetramethyldisiloxane, in excess in the presence of catalyst ( 3) can be represented by the following reaction scheme (1):

The Siloxancopolymermischung obtained here contains a proportion of preferably more than 50% of individual compounds T ₃ and T ₄ and higher branched polymers.

ever after the stoichiometric relationship H-Si / C = C contains the siloxane copolymer mixture changing amounts of organosiloxane (2), which removes at low molecular weights in vacuo can be, otherwise as a component with active hydrogen in the product mixture remains.

As the addition of Si-bonded hydrogen to aliphatic double bond-promoting catalysts (3), the same catalysts can be used in the inventive method, which could also be used to promote the attachment of Si-bonded hydrogen to aliphatic double bond. The catalysts (3) are preferably a metal from the group of platinum metals or a compound or a complex from the group of platinum metals. Examples of such catalysts are metallic and finely divided platinum which may be supported on supports such as silica, alumina or activated carbon, compounds or complexes of platinum such as platinum halides, eg PtCl ₄ , H ₂ PtCl ₆ .6H ₂ O, Na ₂ PtCl ₄ · 4H ₂ O, platinum-olefin complexes, platinum-alcohol complexes, platinum-alcoholate complexes, platinum-ether complexes, platinum-aldehyde complexes, platinum-ketone complexes, including reaction products of H ₂ PtCl ₆ · 6H ₂ O and cyclohexanone, platinum-vinylsiloxane complexes such as platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complexes with or without detectable inorganic halogenated content, bis (gamma-picoline) platinum dichloride, trimethylene dipyridine platinum dichloride, dicyclopentadiene platinum dichloride , Dimethylsulfoxydethylenplatinum (II) dichloride, cyclooctadiene-platinum dichloride, norbornadiene-platinum dichloride, gamma-picoline-platinum dichloride, cyclopentadiene-platinum dichloride.

Of the Catalyst (3) is preferably used in the first process step Amounts from 0.5 to 100 ppm by weight (parts by weight per million parts by weight), preferably in amounts of from 2 to 10 ppm by weight, calculated in each case as elemental platinum and based on the total weight of compound (1) and organosiloxane (2) used.

Of the first process step is preferably at the pressure of the surrounding The atmosphere, So at about 1020 hPa (abs.) Performed, but it can also be at higher or lower pressures carried out become. Furthermore, the first method step is preferably included a temperature of 20 ° C up to 150 ° C, preferably 20 ° C up to 120 ° C, particularly preferably 20 ° C up to 100 ° C carried out.

There the compound having at least three aliphatic double bonds (1), e.g. B. 1,2,4-trivinylcyclohexane, at higher temperatures for polymerization tends, can in the first process step preferably radical inhibitors, such as 4-methoxyphenol, 2,6-bis (tert-butyl) -4-methylphenol, phenothiazine, hydroquinone or Catechol be used. The radical inhibitors will be preferably in amounts of from 10 to 500 ppm by weight, based on the total weight of compound (1) and organosiloxane (2) used.

In the first as well as in the second process step may preferably inert, organic solvents be used. examples for inert, organic solvents are toluene, xylene, octane isomers, heptane isomers, butyl acetate, 1,2-dimethoxyethane, tetrahydrofuran and cyclohexane.

The optionally used inert organic solvents can removed by distillation after the first or second process step be or remain in the reaction mixture.

α, ω-dialkenylsiloxane polymer (4) is used in the second process step in amounts such that the ratio of aliphatic double bond in α, ω-dialkenylsiloxane polymer (4) to Si-bonded hydrogen in the one obtained in the first step Hydrocarbon-siloxane copolymer 1.2 to 10, preferably 1.5 to 5.0, more preferably 2.0 to 4.0.

Because α, ω-dialkenylsiloxane polymer (4) in surplus is used, therefore, react in the second process step preferably all Si-bonded hydrogen atoms from those in the first Process step obtained hydrocarbon siloxane copolymers and there are Alkenyl-containing siloxane copolymers obtained.

Of the Catalyst (3) is preferably used in the second process step Amounts from 0.5 to 100 ppm by weight (parts by weight per million parts by weight), preferably in amounts of from 2 to 10 ppm by weight, calculated in each case as elemental platinum and based on the total weight of α, ω-dialkenylsiloxane polymer (4) and the Si-bonded ones obtained in the first process step Hydrogen-containing hydrocarbon-siloxane copolymers.

Of the second process step is preferably at the pressure of the surrounding The atmosphere, So at about 1020 hPa (abs.) Performed, but it can also be at higher or lower pressures carried out become. Furthermore, the second method step is preferably included a temperature of 20 ° C up to 150 ° C, preferably 20 ° C up to 120 ° C, carried out.

The having alkenyl groups obtained in the second process step Siloxane copolymers can in a third process step with organopolysiloxane (5) equilibrated become.

Of the if necessary, third step, the equilibration, increases the average chain lengths the components used (2) and (4).

Also in the third process step, higher branched siloxane copolymers are used receive. During equilibration, the formation of cycles is without functional groups known to those skilled in the art and in quantities from 8 to 15 wt .-%, unavoidable, but not disturbing. If desired can their volatile shares (Cycles with 3-9 Si atoms) by vacuum and higher Temperatures are removed from the product mixture. As well as the cycles can in the equilibration other unwanted but not disturbing by-products be obtained in small quantities.

Organopolysiloxanes (5) are preferably those selected from the group consisting of preferably linear, terminal triorganosiloxy-containing organopolysiloxanes of the formula R ₃ SiO (SiR ₂ O) _r SiR ₃ , where R has the meaning given above and
r is 0 or an integer of preferably 1 to 1500, preferably 10 to 300,
linear, terminal hydroxyl-containing organopolysiloxanes of the formula HO (SiR ₂ O) _s H, where R has the meaning given above and
s is an integer in the value of preferably 1 to 1500, preferably 10 to 300,
branched, optionally hydroxyl-containing organopolysiloxanes from units of the formula R ₃ SiO _1/2 , R ₂ SiO and RSiO _3/2 , wherein R has the meaning given above, cyclic organopolysiloxanes of the formula (R ₂ SiO) _t , where R has the meaning given above and
t is an integer from 3 to 12,
and copolymers of units of the formula R ₂ SiO and RSiO _3/2 , where R has the meaning given above, used.

Preferred organopolysiloxanes (5) are preferably those of the formulas R ₃ SiO (SiR ₂ O) _r SiR ₃ , HO (SiR ₂ O) _s H and (R ₂ SiO) _t , where those of the formula R ₃ SiO (SiR ₂ O) _r SiR ₃ are particularly preferred.

The ratio the one used in the event of any necessary equilibration Organopolysiloxanes (5) and alkenyl-containing siloxane copolymers is only by the desired Proportion of alkenyl groups in the equilibration that may be carried out produced siloxane copolymers and determined by the desired average chain length.

In the optionally performed equilibration preferably basic or acidic catalysts which promote the equilibration used. Examples of such catalysts are preferably alkali hydroxides, such as sodium hydroxide, potassium hydroxide, and cesium hydroxide, trimethylbenzylammonium hydroxide and tetramethylammonium hydroxide. Preference is given to alkali metal hydroxides. Alkali hydroxides are preferably used in amounts of 50 to 10,000 ppm by weight (= parts per million), in particular 500 to 2,000 ppm by weight, depending Weil based on the total weight of the alkenyl groups used siloxane copolymers and organopolysiloxanes (5) used.

Examples for sour Catalysts are preferably sulfuric acid, phosphoric acid, trifluoromethanoic acid, phosphonitrile chlorides and under the reaction conditions solid, acidic catalysts, such as acid-activated Bleaching earth, acid zeolites, sulfonated coal and sulfonated styrene-divinylbenzene copolymer. Prefers are phosphonitrile chlorides. Phosphonitrile chlorides are preferred in amounts of from 5 to 1000 ppm by weight (= parts per million), in particular 50 to 200 ppm by weight, based in each case on the total weight of the used Organosilicon compounds, used.

The possibly carried out Equilibration is preferably carried out at 100 ° C to 150 ° C and at ambient pressure The atmosphere, So at about 1020 hPa (abs.) performed. If desired, but can also higher or lower pressures be applied. The equilibration is preferably in 5 to 20 Wt .-%, based on the total weight of the alkenyl groups used in each case having siloxane copolymers and organopolysiloxanes used (5), in water immiscible solvent, such as toluene. In front the workup of the mixture obtained in the equilibration can the catalyst is rendered ineffective.

The inventive method can be carried out batchwise, semicontinuously or fully continuously.

Alternatively to the described sequence of the process steps for the production of alkenyl-containing hydrocarbon siloxane copolymers, if desired, an increase in the average molecular weight or a chain extension of the obtained in the 1st step active hydrogen-containing hydrocarbon siloxane copolymers by equilibration also directly thereafter in a 2. Process step done. For this purpose, the same organopolysiloxanes (5) are used and reacted under the conditions described there. Preferred organopolysiloxanes (5) are those of the formulas R ₃ SiO (SiR ₂ O) _r SiR ₃ , HO (SiR ₂ O) _s H and (R ₂ SiO) _t , where those of the formula R ₃ SiO (SiR ₂ O) _r SiR _{3 are} particularly preferred and R has the same meaning as above.

at This alternative sequence of method steps are then described in a third step, the active hydrogen obtained by equilibration comprising hydrocarbon-siloxane copolymers with α, ω-dialkenylsiloxane polymer (4) implemented, this being preferably used in amounts, that the ratio of aliphatic double bond in (4) to Si-bonded hydrogen in previously obtained copolymer is preferably 1.5-5.0, more preferably 2.0-4.0.

at This alternative sequence of process steps are thus merely the steps described above reversed in order, so that method step 3 is carried out before method step 2.

When defoamers are preferably such alkenyl-containing siloxane copolymers used, which produced without a further equilibration step be and have particularly high branching. Preferred additives are obtained when in the specified particularly preferred stoichiometric Areas is being worked on. Since these siloxane copolymers usually have higher viscosities, can you for easier handling after production with further siloxane (4) to be mixed.

• (a) 100 Gew.-Teile mindestens eines erfindungsgemäßen Alkenylgruppen aufweisenden Siloxancopolymeren,
• (b) 0,1 bis 30 Gew.-Teile, bevorzugt 1 bis 10 Gew.-Teile, besonders bevorzugt 2 bis 8 Gew.-Teile, mindestens eines Füllstoffes
• (c) 0 bis 900 Gew.-Teile, bevorzugt 1 bis 100 Gew.-Teile, besonders bevorzugt 2 bis 10 Gew.-Teile, mindestens eines Polyorganosiloxans ausgewählt aus der Gruppe von (i) Polyorganosiloxanen der Formel R_a(R⁵O)_bSiO_(4-a-b)/2 (IV) worin R gleich oder verschieden sein kann und die oben dafür angegebene Bedeutung hat, R⁵ gleich oder verschieden sein kann und ein Wasserstoffatom oder einen einwertigen, substituierten und/oder unsubstituierten gesättigten und/oder ungesättigten Kohlenwasserstoffrest mit 1 bis 30 Kohlenstoffatomen je Rest bedeutet, b 0, 1, 2 oder 3 ist, wobei b durchschnittlich ein Wert von kleiner als 0,5 ist, a 0, 1, 2 oder 3 ist, mit der Maßgabe, dass die Summe (a + b) kleiner oder gleich 3 ist und durchschnittlich einen Wert von 1,8 bis 2,4, aufweist, (ii) Siliconharzen, welche im Wesentlichen aus Einheiten der allgemeinen Formel R₃SiO_1/2 und SiO_4/2 besteht, wobei R die oben dafür angegebene Bedeutung hat, und Mischungen von (i) und (ii).

The invention also provides antifoam formulations containing

• (a) 100 parts by weight of at least one alkenyl-functional siloxane copolymer according to the invention,
• (B) 0.1 to 30 parts by weight, preferably 1 to 10 parts by weight, particularly preferably 2 to 8 parts by weight, of at least one filler
• (c) 0 to 900 parts by weight, preferably 1 to 100 parts by weight, more preferably 2 to 10 parts by weight, of at least one polyorganosiloxane selected from the group of (i) polyorganosiloxanes of the formula R _a (R ⁵ O) _b SiO _{(4-ab) / 2} (IV) wherein R may be the same or different and has the meaning given above, R ^{5 may be the} same or different and a hydrogen atom or a monovalent, substituted and / or unsubstituted saturated and / or unsaturated hydrocarbon radical having 1 to 30 carbon atoms b is 0, 1, 2 or 3, where b is on the average a value of less than 0.5, a is 0, 1, 2 or 3, with the proviso that the sum (a + b) is less than or equal to 3 and has an average value of 1.8 to 2.4, (ii) silicone resins, which consists essentially of units of the general formula R ₃ SiO _1/2 and SiO _4/2 , wherein R is the above as defined, and mixtures of (i) and (ii).

Silicone resins (ii) consisting essentially of R ₃ SiO _1/2 (M) and SiO _4/2 (Q) units are referred to as MQ resins. The molar ratio of M units to Q units is preferably in the range of 0.5 to 2.0, preferably 0.6 to 1.0. The silicone resins may contain up to 10% by weight of free hydroxy or alkoxy groups.

Preferably these silicone resins have at 25 ° C a viscosity greater than 1000 mPas or are solids. The with gel permeation chromatography certain weight-average molecular weight (based on a polystyrene standard) of these resins is preferably 200 to 200,000 g / mol, in particular 1000 to 20,000 g / mol.

These Silicone resins are commercially available Products or can according to common methods in silicon chemistry e.g. according to EP-A 927 733 are made.

Especially preferably contains the defoamer formulation at least 1-30 Parts by weight of silicone resin (c) (ii).

The The above composition refers to the total weight of the defoamer formulation without possibly for dilution added solvents or water used in the emulsification, ie non-volatile Proportions of the antifoam formulation according to the invention.

Examples of radicals R ⁵ in the general formula (IV) are unsubstituted, branched or unbranched alkyl radicals, such as methyl, ethyl, propyl, isopropyl, hexyl, 2-ethylhexyl, octyl, or dodecyl radicals; substituted alkyl radicals such as trifluoropropyl, cyanoethyl, glycidoxypropyl, polyalkylene glycolpropyl, aminopropyl or aminoethylaminopropyl radicals.

Examples of compounds of the formula (IV) are polydimethylsiloxanes having viscosities of 100 to 1,000,000 mPa · s at 25 ° C. These polydimethylsiloxanes may, for. B. by the incorporation of RSiO _3/2 - or SiO _4/2 units branched. These branched or cross-linked siloxanes then have viscoelastic properties.

Furthermore, the defoamer formulation as polyorganosiloxane (c ') 0.1 to 15 parts by weight, preferably 0.5 to 8 parts by weight, per 100 parts by weight of the invention alkenyl-containing siloxane copolymers, at least one polyorganosiloxane of the general formula ( IV), wherein R is a methyl radical and R ^{5 is} a linear and / or branched hydrocarbon radical having at least 6 carbon atoms, b assumes a value of 0.005 to 0.5 and the sum (a + b) has a value of 1.9 to 2 , 1 accept. Such products are accessible, for example, by alkaline-catalyzed condensation of silanol-terminated polydimethylsiloxanes having a viscosity of 50 to 50,000 mPa · s at 25 ° C. and aliphatic alcohols having more than 6 carbon atoms, such as isotridecyl alcohol, n-octanol, stearyl alcohol, 4-ethylhexadecanol or eicosanol ,

As fillers (b), which are preferably hydrophobic, silicon dioxide, titanium dioxide, aluminum oxide, metal soaps, quartz powder, PTFE powder, fatty acid amides such as Ethylenbisstearamid or finely divided hydrophobic polyurethanes can be used. Particular preference is given to silicas having a BET surface area greater than 50 g / m ² . These silicas may be fumed or precipitated silicas. Both pretreated silicic acids can be used, ie commercially available hydrophobic silicic acids, as well as hydrophilic silicic acids. Hydrophilic silicas may be rendered hydrophobic in situ, if this is advantageous for the desired antifoam formulation effectiveness. The in situ hydrophobing of the silica can be carried out by heating the silica dispersed in the polyorganosiloxane (c) of the formula (II) or in the mixture of inventive compound (a) and compound (c) of the formula (II) at temperatures of 100 to 200 ° C done. In this case, the reaction by the addition of catalysts, such as KOH, and hydrophobing agents, such as short-chain OH-terminated polydimethylsiloxanes, silanes, silazanes or silicone resins be supported.

A Another alternative is the use of a combination of in situ hydrophobicized silicas with pretreated hydrophobicized silicas.

The defoamer can add other additives (d) included.

As further additives, the antifoam formulations according to the invention may contain 0 to 900 parts by weight, preferably 20 to 200 parts by weight, per 100 parts by weight of the alkenyl-containing siloxane copolymers of the invention, an organic compound having a boiling point greater than 100 ° C. selected from Mineral oils, native oils, isoparaffins, polyisobytylenes, residues from the oxoalcohol synthesis, esters of low molecular weight synthetic carboxylic acids, fatty acid esters, fatty alcohols, ethers of low molecular weight alcohols, phthalates, esters of phosphoric acid and waxes. The antifoam formulations according to the invention may also contain 0 to 100 parts by weight, preferably 0 to 15 parts by weight, per 100 parts by weight of the siloxane copolymers having alkenyl groups according to the invention, modified polysiloxanes which may be linear or branched and contain at least one polyether grouping , Such polyether-modified polysiloxanes are known and, for example, in EP 1076073 A described.

The Producing the antifoam formulations according to the invention is carried out by known methods by mixing the compound (a) with compound (c), the fillers (b) and optionally further additives (d), for example, under Application of high shear forces in colloid mills, Dissolvers or rotor-stator homogenizers. The mixing process can be carried out at reduced pressure to the Mixing of air, which is contained in highly dispersed fillers, too prevent. Following this, if necessary, the in situ hydrophobing the fillers respectively.

It is possible, too, that the preparation of compound (a) in compounds of formula (c) takes place, and only the filler must be dispersed.

A further variant for the preparation of the antifoam formulations according to the invention is that a compound (a) with a compound (c) of the formula (IV) and in the presence of a catalyst, the equilibration, polymerization and or condensation of Promotes siloxanes be reacted and then the addition of fillers and optionally in situ hydrophobing takes place. The temperature and the time for that this reaction is necessary, hang from the catalyst.

Of the Addition of defoamer formulation to the foaming ones Fleets can be made directly, in suitable organic solvents, as dissolved in methyl ethyl ketone or t-butanol, added as a powder or as an emulsion become.

• (A) erfindungsgemäße Entschäumerformulierungen
• (B) Emulgatoren und
• (C) Wasser.

If emulsions of defoamer formulations are used, they preferably contain

• (A) Defoamer formulations according to the invention
• (B) emulsifiers and
• (C) water.

• (A) 2 bis 50 Gew.-%, besonders bevorzugt 5 bis 30 Gew.-%, erfindungsgemäße Entschäumerformulierungen
• (B) 0,5 bis 30 Gew.-%, besonders bevorzugt 2 bis 15 Gew.-%, Emulgatoren, und gegebenenfalls Verdicker, Biozide und andere Hilfsstoffe und
• (C) die Differenz bis zu 100 Gew.-% Wasser,

jeweils bezogen auf das Gesamtgewicht der Emulsionen der Entschäumerformulierungen.Emulsions of antifoam formulations containing them are preferred

• (A) 2 to 50 wt .-%, particularly preferably 5 to 30 wt .-%, according to the invention defoamer formulations
• (B) 0.5 to 30 wt .-%, particularly preferably 2 to 15 wt .-%, emulsifiers, and optionally thickeners, biocides and other auxiliaries and
• (C) the difference up to 100% by weight of water,

in each case based on the total weight of the emulsions of defoamer formulations.

The Emulsifiers needed to prepare the emulsions can be anionic, cationic or non-ionic, and are those of skill in the art of stable silicone emulsions. Preference is given to emulsifier mixtures where at least one nonionic emulsifier, such as, for example, sorbitan fatty acid esters, ethoxylated sorbitan fatty acid esters, ethoxylated fatty acids, ethoxylated linear or branched alcohols with 10 to 20 Carbon atoms and / or glycerol esters should be included.

Furthermore, further additives may be added to the defoamer formulation. Examples of this are known as thickeners compounds such as polyacrylic acid, polyacrylates, cellulose ethers such as carboxymethyl cellulose and hydroxyethyl cellulose, natural gums such as xanthan gum and polyurethanes; Biocides, preservatives and other common additives and adjuvants known to those skilled in the art.

technologies for the preparation of silicone emulsions are known. Usually the preparation is done by simply stirring all the ingredients and possibly subsequent Homogenize with rotor-stator homogenizers, colloid mills or Homogenizers.

The antifoam formulations according to the invention can also be further processed to give free-flowing powders. These are preferred, for example, when used in powder detergents. These antifoam powders contain, for example, 2-20% by weight of the defoamer formulations. The carriers used are, for example, zeolites, sodium sulfate, cellulose derivatives, urea and sugar. Further constituents of the antifoam powder may be, for example, waxes or organic polymers, as used, for example, in US Pat EP 887097 A and EP 1060778 A are described. The preparation of these powders is carried out according to the expert method, such as spray drying or build-up granulation.

The Defoamer formulations according to the invention can be everywhere be used where disturbing Foam suppressed shall be. This is e.g. in non-aqueous systems, such as the Tar distillation or petroleum processing the case.

Especially are suitable defoamer formulations of the invention for fighting of foam in watery Surfactant systems, wherein they are compared to Defoamer formulations according to the state the technology by a higher, longer distinguish lasting efficacy with small amounts added. The Defoamer formulations according to the invention can therefore find use in detergents and cleaners, and are in the fight of foam in sewage plants, in textile dyeing processes, in natural gas scrubbing, in Polymer dispersions, and for defoaming during pulp production accumulating aqueous Media can be used.

EXAMPLES

In the examples below describe all information of parts and percentages, unless otherwise stated, by weight. Further relate all viscosity data to a temperature of 25 ° C.

Description of the used highly branched polymer:

Polymer 1:

A mixture of 75.2 g of 1,2,4-trivinylcyclohexane and 1242 g of an α, ω-dihydrogendimethylpolysiloxane having an active hydrogen content of 0.185 wt .-% was at 25 ° C by adding 0.26 g of a Karstedt catalyst solution with 1 wt % Pt content activated. The immediate exothermic reaction heated the batch to 82 ° C, with a conversion of C = C groups of more than 99% is achieved ( ¹ H-NMR). The resulting branched hydrogen-functional siloxane polymer has a viscosity of 159 mm ² / s (25 ° C) and an active hydrogen content of 0.70 meq / g. From this precursor, a branched vinyl polymer is prepared by mixing 68 g of this product with 647 g of α, ω-divinyldimethylpolysiloxane having a chain length of 100 silicon atoms and activating with 10 ppm of platinum in the form of a solution of the Karstedt catalyst. With slight warming, the mixture becomes considerably more viscous and finally reaches 3570 mm ² / s (25 ° C).

manufacturing the defoamer according to the invention

Example 1:

90 parts of polymer 1, 5 parts of a fumed silica having a BET surface area of 300 m ² / g, 3 parts of a polydimethylsiloxane having terminal C ₂₀ alkoxy, 2 parts of a silicone resin, which consists essentially of units of the general formula R ₃ SiO _{1 / 2} and SiO _4/2 , and 0.7 part of a 20% methanolic KOH were mixed with a dissolver and heated to 150 ° C for 4 h. There was obtained a defoamer with a viscosity of 9600 mPas.

Example 2:

90 parts of polymer 1, 5 parts of a fumed silica having a BET surface area of 300 m2 / g, 5 parts of a silicone resin, which consists essentially of units of the general formula R ₃ SiO _1/2 and SiO _4/2 , and 0, 7 parts of a 20% methanolic KOH were mixed with a dissolver and heated to 150 ° C for 4 h. An antifoam with a viscosity of 14560 mPas was obtained.

Example 3:

65 parts of polymer 1, 20 parts of a polydiorganosiloxane with 50 mol% of units of the formula Si (CH ₃ ) [CH ₂ CH (CH ₃ ) C ₆ H ₅ ] O _2/2 (based on the total amount of silicon) 5 parts of a pyrogenic Silica having a BET surface area of 400 m ² / g, 6 parts of a polydimethylsiloxane having terminal C ₂₀ -alkoxy groups, 4 parts of a silicone resin consisting essentially of units of the general formula R ₃ SiO _1/2 and SiO _4/2 , and 0.7 part of a 20% methanolic KOH were mixed with a dissolver and heated at 150 ° C for 4 h. A defoamer with a viscosity of 514,000 mPas was obtained.

Comparative tests:

Comparative Experiment V1:

Defoamer after EP 301531 A , Example 1

An antifoam base is prepared by mixing 2.5 parts of a condensation product having a viscosity of 180 mPas prepared from octyldodecanol and a silanol-terminated polydimethylsiloxane having a viscosity of 40 mPas and 5 parts of a 50% toluene solution of a silicone resin of 40 mol% trimethylsiloxy and 60 mol% SiO _4/2 groups and subsequent removal of the volatile constituents.

A mixture of 89.3 parts by weight of a trimethylsiloxy-terminated polydimethylsiloxane having a viscosity of 1000 mPas at 25 ° C (available from Wacker-Chemie GmbH, Germany under the name "silicone oil AK 5000"), 5 parts by weight of the above-mentioned defoamer, 5 parts hydrophilic pyrogenic silica having a BET surface area of 300 m ² / g (available from Wacker-Chemie GmbH, Germany under the name ^HDK® T30) and 0.7 part by weight of a methanolic KOH are heated at 150 ° C. for 2 hours an antifoam having a viscosity of 25,600 mPas.

Comparative experiment V2:

Defoamer after EP 163541 A , Example 1

A branched polyorganosiloxane is prepared by reacting 378 g of a trimethylsiloxy-terminated polydimethylsiloxane having a viscosity of 1000 mPas at 25 ° C. (available from Wacker-Chemie GmbH, Germany under the name "Silicone Oil AK 1000"), 180 g of one having silanol groups terminated polydimethylsiloxane having a viscosity of 10000 mPas at 25 ° C (available from Wacker-Chemie GmbH, Germany under the name "Polymer FD 10") and 18 g of ethyl silicate (available from Wacker-Chemie GmbH, Germany under the name "SILIKAT TES 40) in the presence of 0.3 g KOH by heating to 140 ° C. Subsequently, 30 g of a hydrophilic fumed silica having a BET surface area of 200 m ² / g (available from Wacker-Chemie GmbH, Germany under the name HDK ^® N20) and 30 g of a silanol-terminated polydimethylsiloxane having a viscosity of 40 mPas is added, and the mixture is heated for a further 4 hours at 180 ° C and freed at 50 hPa of volatiles. A viscous colorless defoamer formulation having a viscosity of 68,640 mPas was obtained.

Tests of Defoamer

1. Stirring test

300 ml of a solution containing 1% of a defoamer-free washing powder was foamed for 5 minutes with a stirrer at a speed of 1000 revolutions / min. Subsequently, 100 .mu.l of a 10% strength solution of the defoamer (in each case according to Examples 1 to 3 and Comparative Experiments 1 and 2) in methyl ethyl ketone were added and stirring continued for a further 10 minutes. During the whole time will be recorded the foam height.

When Measure of effectiveness The average foam height is 9-10 minutes based on the foam height without defoamers after 2-3 min calculated. The lower this value is, the more effective it is the defoamer.

The Results are summarized in the table.

2nd test in of the washing machine

To 100g of defoamer-free Washing powder was 0.1 g defoamer (in each case according to the examples 1 to 3 and Comparative Experiments 1 and 2). The washing powder was then combined with 3500 g of clean cotton linen in a drum washing machine (type Miele Novotronik W918 without Fuzzy Logic) given. Subsequently the washing program is started and the foam height over a period of 55 min recorded. From the over foam notes determined over the entire period (0 no foam measurable to 6 effervescence) is the average foam grade determined. The lower this average Foam note is the more effective the defoamer.

The Results are summarized in the table.

3rd exam in black liquor

These exam was with watery Emulsions based on the in the examples and the comparative experiments described defoamers carried out. These emulsions each contain 20% silicone defoamer, 10 % of a mixture of soybean oil, an ethoxylated isotridecyl alcohol (HLB value of 11.2), an ethoxylated Stearyl alcohol (HLB 9.7), pentaerythritol distearate and a polyethersiloxane as emulsifier and 0.3% formaldehyde as preservative.

400 ml of black liquor (hardwood from the processing of birch) were in a 1 liter graduated cylinder with wash bottle attachment for 15 minutes a thermostat at 80 ° C tempered. After addition of 20 .mu.l the defoamer emulsion the black liquor was pumped at a rate of 2.3 l / min. It was the time t between the beginning of the test and the time when the foam had risen to 75 mm, measured.

ever longer this period is t, the more effective the defoamer.

The Results are summarized in the table.

Table:

The better effectiveness of the defoamer according to the invention compared to the state the technique is clearly visible.

Claims (12)

Use of siloxane copolymers as defoamers, characterized in that alkenyl-containing siloxane copolymers can be prepared as siloxane copolymers by, in a first step, having at least three aliphatic double bonds (1) of the general formula R ² (CR ³ = CH ₂ ) _x (II) wherein R ^{2 is} a trivalent or tetravalent hydrocarbon radical preferably having 1 to 25 carbon atoms per radical, which may contain one or more separate heteroatoms selected from the group of oxygen, silicon and titanium, R ^{3 is} a hydrogen atom or an alkyl radical having 1 to 6 carbon atoms each radical and x is 3 or 4, is reacted with an organosiloxane (2) having terminal Si-bonded hydrogen atoms in the presence of the addition of Si-bonded hydrogen to aliphatic double bond promoting catalyst (3), wherein the ratio of Si used hydrogen bonded in the organosiloxane (2) to aliphatic double bond in organic compound (1) 1.3 to 10, preferably 1.5 to 5, in a second step, the thus obtained, Si-bonded hydrogen atoms having hydrocarbon siloxane copolymers with α, ω Dialkenylsiloxane polymer (4) in the presence of attachment of Si-bonded hydrogen to aliph in which the ratio of aliphatic double bond in the α, ω-dialkenylsiloxane polymer (4) to Si-bonded hydrogen in the siloxane copolymers is from 1.2 to 10, preferably from 1.5 to 5, and optionally in a third step, the thus obtained alkenyl-containing siloxane copolymers with organopolysiloxane (5) selected from the group consisting of linear, terminal triorganosiloxy-containing organopolysiloxanes, linear, terminal hydroxyl-containing organopolysiloxanes, branched, optionally hydroxyl-containing organopolysiloxanes, cyclic organopolysiloxanes and copolymers of diorganosiloxane and Monoorganosiloxaneinheiten to be used, be used. Use according to claim 1, characterized in that as the organosiloxane (2) those of the general formula HR ₂ SiO (SiR ₂ O) _n SiR ₂ H (II), where R is the same or different, optionally halogenated hydrocarbon radicals having 1 to 6 carbon atoms per radical and n is 0 or an integer is used. Use according to claim 1 or 2, characterized in that the organic compound (1) used is those in which R ^{2 is} a trivalent hydrocarbon radical having 1 to 25 carbon atoms per radical and x is 3. Use according to claim 1, 2 or 3, characterized in that 1,2,4-trivinylcyclohexane is used as the organic compound (1) becomes. Use according to any one of Claims 1 to 4, characterized in that the α, ω-dialkenylsiloxane polymer (4) is one of the general formula R ⁴ _l R ₃ -l SiO (R ₂ Si-R ¹ -SiR ₂ O) _m (R ₂ SiO) _k SiR ⁴ _l R _3-l (III) where R has the abovementioned meaning, R ^{1 is} an alkylene radical having 2 to 10 carbon atoms per radical or a divalent silane or siloxane radical, R ^{4 is} a terminal olefinically unsaturated radical having 2 to 10 C atoms, and l may be identical or different and 0 or 1, an average of 0.7 to 1.0, m is 0 or an integer of 1 to 10, and k is 0 or an integer of 1 to 1000 is used. Use according to one of claims 1 to 5, characterized as α, ω-dialkenylsiloxane polymer (4) α, ω-divinylpolydimethylsiloxanes be used. Defoamer formulations comprising (a) 100 parts by weight of siloxane copolymers having at least one alkenyl group according to one of claims 1 to 6, (b) 0.1 to 30 parts by weight of at least one filler (c) 0 to 900 parts by weight of at least one Polyorganosiloxane selected from the group of (i) polyorganosiloxanes of the formula R _a (R ⁵ O) _b SiO _{(4-ab) / 2} (IV) wherein R may be the same or different and has the meaning given above, R ^{5 may be the} same or different and represents a hydrogen atom or a monovalent, substituted and / or unsubstituted, saturated and / or unsaturated hydrocarbon radical having 1 to 30 carbon atoms per radical, b 0, 1, 2 or 3, where b is on the average a value less than 0.5, a is 0, 1, 2 or 3, with the proviso that the sum (a + b) is less than or equal to 3 and has an average value of 1.8 to 2.4, (ii) a silicone resin which consists essentially of units of the general formula R ₃ SiO _1/2 and SiO _4/2 , where R has the meaning given above, and mixtures of (i) and (ii). Defoamer formulations according to claim 7 comprising (a) 100 parts by weight of siloxane copolymers having at least one alkenyl group according to one of claims 1 to 6, (b) 2 to 8 parts by weight of at least one filler (c) 2 to 1.0 part by weight of at least a polyorganosiloxane selected from the group of (i) polyorganosiloxanes of the formula R _a (R ⁵ O) _b SiO _{(4-ab) / 2} (IV), wherein R may be the same or different and has the meaning given above, R ^{6 may be the} same or different and represents a hydrogen atom or a monovalent, substituted and / or unsubstituted saturated and / or unsaturated hydrocarbon radical having 1 to 30 carbon atoms per radical, b 0, 1, 2 or 3, where b is on the average a value less than 0.5, a is 0, 1, 2 or 3, with the proviso that the sum (a + b) is less than or equal to 3 and has an average value of 1.8 to 2.4, (ii) a silicone resin which consists essentially of units of the general formula R ₃ SiO _1/2 and SiO _4/2 , where R has the meaning given above, and mixtures of (i) and (ii). Defoamer formulations according to Claim 7, containing (a) 100 parts by weight of siloxane copolymers having at least one alkenyl group according to one of Claims 1 to 6, (b) 0.1 to 30 parts by weight of at least one filler (c) 1 to 30% by weight. Parts (ii) of a silicone resin consisting essentially of units of the general formula R ₃ SiO _1/2 and SiO _4/2 , where R has the meaning given in Claim 7, Containing emulsions of antifoam formulations (A) defoamer according to claim 7, 8 or 9 (B) emulsifiers and (C) water. Use of antifoam formulations according to claim 7, 8 or 9 emulsions of defoaming Merformulierungen according to claim 10 for defoaming aqueous surfactant systems. Use of antifoam formulations according to claim 7, 8 or 9 or emulsions of antifoam formulations according to claim 10 in detergents or cleaners.