DE10314853A1 - New organofunctional modified polysilanes are useful for the defoaming of liquid fuels, preferably diesel fuel - Google Patents

Abstract

Organofunctional modified polysilanes are new. Organofunctional modified polysilanes (I) are of formula (1). R 1polyether group -(CH 2) x(OC 3H 6-) nOR; R : H or monovalent organic group; R 2phenyl group -Ru-(C6H4-zRvz)-ORw; Ru : divalent 1-18C optonally substituted hydrocarbon; Rv : hydroxyl, 1-6C alkyl or alkoxy; Rw : H or 1-6C alkyl, R 3polyether -(F)(O(C xH 2xO) rZ) g; Z : H or monovalent organic group; F : (g+1)valent, optionally branched hydrocarbon; a+b+c+d= 200-350 ; a/(b+c+d)=3-5; b= at lest 35 %; c= at least 10 %; d= 0-55%; k= 3-6; n= 28-35; g >=1; x= 2-4; r= greater than 1 [Image].

Description

The The invention relates to organofunctionally modified polysiloxanes reduced silicon content and their use for defoaming liquid Fuels, especially diesel fuels.

The hydrocarbon mixtures used as diesel fuel, the also aromatics, gas oil and can contain kerosene, have the uncomfortable property when filling in storage containers, such as Storage tanks and fuel tanks of motor vehicles, in connection with air, to develop foam. This leads to delay the filling process and insufficient filling the container. It is therefore common the diesel fuel defoamer add. These defoamers should be in as possible low concentration and may be effective when burning the Diesel fuel in the engine does not form harmful residues or the combustion of the fuel negatively affect. Correspondingly effective defoamers Polysiloxane-based are described in the patent literature.

Such silicone polyether copolymers work because they are only partially soluble in diesel fuel and the surface tension of the diesel fuel is reduced. The dimethylsiloxane units reduce the surface energy of the diesel fuel, while the polyether side chain reduces the solubility of the copolymer in the fuel. The known copolymers, also known as polyether siloxanes or as organofunctionally modified polysiloxanes and with the general formula Me ₃ Si (OSiMe ₂ ) _x (OSiMeR) _y OSiMe ₃ contain, as the radical R, a polyether which arises from the addition of monomers such as propylene oxide, but more often ethylene oxide, to starting alcohols, such as allyl alcohol.

So that affects GB-B-2 173 510 a process for defoaming diesel fuel or jet fuel, in which an anti-foaming agent based on a silicone polyether copolymer is added to the fuel, the polyether of which is described by the general formula Q (A) _n OZ. Q represents a difunctional group attached to an Si atom, A an oxyalkylene group in which at least 80% are oxyethylene units, and Z a hydrogen atom or other monofunctional group.

On The disadvantage of this antifoam is the poor defoaming of damp diesel fuel. Wet diesel fuel means a fuel that contains approx. 250 ppm water. This Water is either condensed water, which is in the storage tanks the fuel gets in, or it gets in oil tankers during transportation, through the incomplete Emptying the tanks of water, entered in the fuel.

The anti-foaming agents are incorporated into the fuel in conjunction with additive packages. These additive packages are added to the raw diesel oil to improve its properties. Additive packages are mixtures of different additives, such as. B. Combustion behavior improving agents, smoke reducing agents, harmful exhaust gas reducing agents, inhibitors to reduce corrosion in the engine and its parts, surfactants, lubricants and the like. Such additive packages are e.g. B. in the GB-A-2 248 068 and in the journal Mineralöltechnik 37 (4), 20 ff. The additives in the additive package are dissolved in an organic solvent to form a stock concentrate that is added to the raw diesel fuel.

It is from the US-A-5 542 960 known that phenol derivatives (particularly preferably eugenol) show a relatively good defoaming capacity in moist diesel fuel.

verwendet werden, wobei
die Reste R¹ Alkyl- oder Arylreste sind,
die Reste R² aus mehreren der nachfolgenden Verbindungsklassen ausgewählt sind: Butenderivate, Alkanolderivate, Polyether und Alkylreste.In the DE-C-43 43 235 describes a process for defoaming diesel fuel, wherein organofunctionally modified polysiloxanes of the general formula

used, where
the radicals R ^{1 are} alkyl or aryl radicals,
the R ² radicals are selected from several of the following classes of compounds: butene derivatives, alkanol derivatives, polyethers and alkyl radicals.

This Butene derivatives and polyethers contain oxyalkylene and oxypropylene units in different compositions.

Also the US-A-5 542 960 describes the use of organopolysiloxanes for defoaming diesel fuel. Terpolymers of the general formula are used as organopolysiloxanes MD _x D * _y D ** _z M used, where M = O _0.5 Si (CH ₃ ) ₃ , D = OSi (CH ₃ ) ₂ , D * = OSi (CH ₃ ) R, D ** = OSi (CH ₃ ) R ', R is one Polyether and R 'are a phenol derivative, the sum x + y + z = 35 to 350, the quotients x / (y + z) = 3 to 6 and y / z = 0.25 to 9. The polyether radical R should have an ethylene oxide content of at least 75%.

verwendet werden, wobei die Reste R¹ Alkyl- oder Arylreste sind, die Reste R² so ausgewählt sind, dass sie dem Rest R¹ gleichen, jedoch mindestens 10 % gleich einem Phenolderivat sind und weitere 10 % aus mehreren der nachfolgenden Verbindungsklassen ausgewählt sind: Butenderivate, Alkanolderivate und Alkylreste. Optional kann ein Polyether verwendet werden, der aus den Monomeren Ethylenoxid und Propylenoxid sowie einem Startalkohol aufgebaut ist. In DE-C-195 16 360 describes a process for defoaming diesel fuel, wherein organofunctionally modified polysiloxanes of the general formula

are used, the radicals R ^{1 being} alkyl or aryl radicals, the radicals R ² being selected such that they are identical to the radical R ¹ but are at least 10% identical to a phenol derivative and a further 10% are selected from several of the following classes of compounds: Butene derivatives, alkanol derivatives and alkyl residues. Optionally, a polyether can be used which is composed of the monomers ethylene oxide and propylene oxide and a starting alcohol.

verwendet werden,
wobei die Reste R_f Alkyl- oder Arylreste sind, jedoch mindestens 80 % der Reste R_f Methylreste sind. R_f ist entweder gleich R¹ oder gleich R² oder R³, mit der Maßgabe, dass mindestens ein Rest R_f der Rest R² ist, wobei R² ein Polyetherrest der Formel -(Y)c[O(C₂H₄-d^R'd^O)_m(C_xH_2xO)_pZ]_w ist, mit der Maßgabe, dass pro Copolymermolekül mindestens ein Rest R' einen gegebenenfalls substituierten Aromaten bezeichnet. Dabei ist c gleich 0 oder 1, d liegt zwischen 1 und 3, m ist größer und gleich 1, x ist eine ganze Zahl zwischen 2 und 4, p ist größer oder gleich 1, w liegt zwischen 1 und 4 und die Summe m+p beträgt zwischen 3 und 100.In EP-A-0 849 352 describes a process for defoaming diesel fuel, wherein aromatic-containing silicone polyether copolymers of the general formula

be used,
wherein the radicals R _{f are} alkyl or aryl radicals, but at least 80% of the radicals R _{f are} methyl radicals. R _f is either equal to R ¹ or equal to R ² or R ³ , with the proviso that at least one radical R _{f is} the radical R ² , wherein R ^{2 is} a polyether radical of the formula - (Y) c [O (C ₂ H ₄ -d ^{R '} d ^O ) _m (C _x H _2x O) _p Z] _w with the proviso that at least one radical R 'denotes an optionally substituted aromatic per copolymer molecule. Here, c is 0 or 1, d is between 1 and 3, m is greater than and equal to 1, x is an integer between 2 and 4, p is greater than or equal to 1, w is between 1 and 4 and the sum m + p is between 3 and 100.

R ³ is an aromatic-free polyether radical of the formula - (F) _q [O (C _x H _2x O) _r Z] _g where g can be between 1 and 4, q is 0 or 1, x is between 2 and 4, r is greater than or equal to 3 and F is a g-bonded hydrocarbon radical which can also be branched.

there More than 65% of silicone polyether copolymers are said to contain an aromatic compound Contain polyether.

beschrieben, wobei
R¹ Alkylreste mit 1 bis 4 Kohlenstoffatomen oder Arylreste sind, jedoch mindestens 80 % der Reste R¹ Methylreste sind,
R² die Reste R^2A, R^2B und R^2C bedeuten, wobei die Reste R^2A aus folgenden Resten ausgewählt sind:

• (a) ein Phenylderivat mit der allgemeinen Formel -R³-(C₆H_4-zR_4z)-OR⁵ wobei R³ ein zweiwertiger Rest ist, der aus einem oder mehreren Kohlenwasserstoffresten mit 1 bis 18 Kohlenstoffatomen zusammengesetzt ist, die gegebenenfalls substituiert sind, R⁴ ein Hydroxyrest, ein Alkylrest mit 1 bis 6 Kohlenstoffatomen oder ein Alkoxyrest mit 1 bis 6 Kohlenstoffatomen ist, und z eine Zahl von 0 bis 4 ist, R⁵ ein einwertiger Rest ist, der gleich oder verschieden ist und aus einem Wasserstoffrest oder Alkylrest mit 1 bis 6 Kohlenstoffatomen besteht,
• (b) ein Polyetherrest der allgemeinen Formel -(Y)[O(C₂H_4-dR⁶d^O)_m(C_xH_2xO)_pZ]_w ist, mit der Bedeutung d = 1 bis 3, m ≥ 1, x = 2 bis 4, p ≥ 1, w = 1 bis 4, Summe m+p = 3 bis 100, R⁶ = ein Wasserstoffrest, ein einwertiger Kohlenwasserstoffrest mit 1 bis 18 Kohlenstoffatomen, der auch aromatisch und gegebenenfalls auch ein substituierter Aromat sein kann, dessen Substituenten aus den Gruppen Wasserstoffrest, Alkylrest mit 1 bis 6 Kohlenstoffatomen, Alkoxyrest und Hydroxyrest ausgewählt sind, wobei die Reste R⁶ unterschiedlich sein können, jedoch pro Copolymermolekül mindestens ein Rest R⁶ einen gegebenenfalls substituierten Aromaten bezeichnet, Z = ein Wasserstoffrest oder ein einwertiger organischer Rest, Y = ein (w+1)-bindiger Kohlenwasserstoffrest, der auch verzweigt sein kann, die Reste R^2B aus folgenden Resten ausgewählt sind:
• (c) ein Alkenderivat mit der allgemeinen Formel
  
  wobei R⁷ einen Rest der Formel -CR⁹H- bedeutet mit R⁹ gleich Wasserstoffatom oder einwertiger organischer Rest, R⁸ einen Rest der Formel C₂H_4-dR¹⁰d bedeutet mit R¹⁰ gleich Wasserstoffatom oder einwertiger Kohlenwasserstoffrest mit 1 bis 18 Kohlenstoffatomen, der auch aromatisch und gegebenenfalls auch ein substi tuierter Aromat sein kann, dessen Substituenten aus den Gruppen Wasserstoffrest, Alkylrest mit 1 bis 6 Kohlenstoffatomen, Alkoxyrest und Hydroxyrest ausgewählt sind, wobei die Reste R¹⁰ unterschiedlich sein können, e und g jeweils 0 oder 1 sind, wobei die Summe e+g 1 oder 2 ist, f und h jeweils 0 oder eine ganze Zahl sind, wobei die Summe f+h durchschnittlich 0 bis 14 ist,
• (d) der Rest -(CH₂-)_iOR¹¹, wobei R¹¹ ein Wasserstoff- oder ein einwertiger organischer Rest, i eine Zahl von 2 bis 20 ist,
• (e) der Rest -(CH₂-)_jCH₃, wobei j eine Zahl von 5 bis 30 ist, der Rest R^2C der Rest -(CH₂-)_k(OC₂H₄-)_l(OC₃H₆-)_nOR¹² ist, wobei R¹² ein Wasserstoff- oder ein einwertiger organischer Rest, k eine Zahl von 2 bis 6, l eine Zahl von 1 bis 50, n eine Zahl von 0 bis 20 ist, mit der Maßgabe, dass mindestens 10 % der Reste R² gleich dem Rest R^2A sind, wobei mindestens 10 % der Reste R^2A gleich dem Rest (a) sind und mindestens 10 % gleich dem Rest (b) sind, die Summe a+b eine Zahl von 2 bis 400 und das Verhältnis der Zahlen b/a zwischen 0,2 und 20 liegt.

In the DE-A-197 26 653 is the defoaming of diesel fuels with polysiloxanes of the general formula

described, where
R ^{1 are} alkyl radicals with 1 to 4 carbon atoms or aryl radicals, but at least 80% of the radicals R ^{1 are} methyl radicals,
R ^{2 is} the radicals R ^2A , R ^2B and R ^2C , the radicals R ^{2A being} selected from the following radicals:

• (a) a phenyl derivative having the general formula -R ³ - (C ₆ H _{4 -z} R _4z ) -OR ⁵ wherein R ^{3 is} a divalent radical which is composed of one or more hydrocarbon radicals having 1 to 18 carbon atoms, which are optionally substituted, R ^{4 is} a hydroxy radical, an alkyl radical with 1 to 6 carbon atoms or an alkoxy radical with 1 to 6 carbon atoms is atom, and z is a number from 0 to 4, R ^{5 is} a monovalent radical which is identical or different and consists of a hydrogen radical or alkyl radical having 1 to 6 carbon atoms,
• (b) a polyether radical of the general formula - (Y) [O (C ₂ H _{4 -d} R ⁶ d ^O ) _m (C _x H _2x O) _p Z] _w is, with the meaning d = 1 to 3, m ≥ 1, x = 2 to 4, p ≥ 1, w = 1 to 4, sum m + p = 3 to 100, R ⁶ = a hydrogen radical, a monovalent hydrocarbon radical with 1 to 18 carbon atoms, which can also be aromatic and optionally also a substituted aromatic, the substituents of which are selected from the groups hydrogen radical, alkyl radical with 1 to 6 carbon atoms, alkoxy radical and hydroxy radical, where the radicals R ⁶ can be different, but at least per copolymer molecule a radical R ⁶ denotes an optionally substituted aromatic, Z = a hydrogen radical or a monovalent organic radical, Y = a (w + 1) -bonded hydrocarbon radical which can also be branched, the radicals R ^2B are selected from the following radicals:
• (c) an alkene derivative with the general formula
  
  where R ^{7 is} a radical of the formula -CR ⁹ H- with R ⁹ is hydrogen atom or monovalent organic radical, R ^{8 is} a radical of formula C ₂ H _4-d R ¹⁰ d with R ¹⁰ is hydrogen atom or monovalent hydrocarbon radical with 1 to 18 carbon atoms, which can also be aromatic and optionally also a substituted aromatic, the substituents of which are selected from the groups hydrogen radical, alkyl radical with 1 to 6 carbon atoms, alkoxy radical and hydroxy radical, where the radicals R ¹⁰ can be different, e and g in each case 0 or are 1, the sum e + g being 1 or 2, f and h each being 0 or an integer, the sum f + h being on average 0 to 14,
• (d) the radical - (CH ₂ -) _i OR ¹¹ , where R ^{11 is} a hydrogen or a monovalent organic radical, i is a number from 2 to 20,
• (e) the residue - (CH ₂ -) _j CH ₃ , where j is a number from 5 to 30, the residue R ^2C the residue - (CH ₂ -) _k (OC ₂ H ₄ -) _l (OC ₃ H ₆ -) _n OR ¹² is where R ^{12 is} a hydrogen or a monovalent organic radical, k is a number from 2 to 6, l is a number from 1 to 50, n is a number from 0 to 20, with the proviso that at least 10% of the radicals R ² are the radical R ^2A , where at least 10% of the radicals R ^2A are the radical (a) and at least 10% are the radical (b), the sum a + b is a number from 2 to 400 and the ratio of Numbers b / a is between 0.2 and 20.

• – Kraftstoffentschäumer mit ausgezeichneten Entschäumereigenschaften sind,
• – dabei der Si-Gehalt in den möglichen Einsatzkonzentrationen gegenüber dem Stand der Technik weiter abgesenkt werden kann,
• – eine ausgezeichnete Verträglichkeit mit Additivpaketen aufweisen, welche üblicherweise Dieselkraftstoffen zugesetzt werden können.

The organopolysiloxanes according to the invention now have the complex property profile that they

• - are fuel defoamers with excellent defoamer properties,
• The Si content in the possible use concentrations can be further reduced compared to the prior art,
• - have excellent compatibility with additive packages, which can usually be added to diesel fuels.

wobei die Summe a+b+c+d zwischen 200 und 350 beträgt, der Quotient a/(b+c+d) ein Wert zwischen 3 und 5 ist,
wobei
der Koeffizient
b mindestens 35 % und
c mindestens 10 % beträgt,
d zwischen 0 und 55 % (jeweils bezogen auf die Summe (b+c+d) beträgt,
der Rest
R₁ ein Polyetherrest der Formel -(CH-)_k(OC₃H₆-)_nOR ist, wobei
R ein Wasserstoff- oder ein einwertiger organischer Rest ist,
k eine Zahl von 3 bis 6,
n eine Zahl von 28 bis 35 ist,
R₂ ein Phenylderivat mit der allgemeinen Formel -R^u-(C₆H_4-zR^vz)-OR^w ist, wobei
R^u ein zweiwertiger Rest ist, der aus einem oder mehreren Kohlenwasserstoffen mit 1 bis 18 Kohlenstoffatomen zusammengesetzt ist, die gegebenenfalls substituiert sind,
R^v ein Hydroxyrest, ein Alkylrest mit 1 bis 6 Kohlenstoffatomen oder ein Alkoxyrest mit 1 bis 6 Kohlenstoffatomen ist und z eine Zahl von 0 bis 4 ist,
R^w ein einwertiger Rest ist, der gleich oder verschieden ist und aus einem Wasserstoffrest oder Alkylrest mit 1 bis 6 Kohlenstoffatomen besteht,
R₃ ist ein Polyetherrest mit der allgemeinen Formel -(F)(O(C_xH_2xO)_rZ)_g mit den Maßgaben
g ≥ 1
x = 2–4
r > 1,
Z ein H-Atom oder ein einwertiger organischer Rest ist, und F ein (g+1)-bindiger Kohlenwasserstoffrest ist.The invention thus relates to organofunctionally modified polysiloxanes of the general formula

where the sum a + b + c + d is between 200 and 350, the quotient a / (b + c + d) is a value between 3 and 5,
in which
the coefficient
b at least 35% and
c is at least 10%,
d is between 0 and 55% (in each case based on the sum (b + c + d),
the rest
R _{1 is} a polyether radical of the formula - (CH-) _k (OC ₃ H ₆ -) _n OR is where
R is a hydrogen or a monovalent organic radical,
k is a number from 3 to 6,
n is a number from 28 to 35,
R _{2 is} a phenyl derivative with the general formula -R ^u - (C ₆ H ₄ -z R ^v z) -OR ^w is where
R ^{u is} a divalent radical which is composed of one or more hydrocarbons having 1 to 18 carbon atoms which are optionally substituted,
R ^{v is} a hydroxyl radical, an alkyl radical with 1 to 6 carbon atoms or an alkoxy radical with 1 to 6 carbon atoms and z is a number from 0 to 4,
R ^{w is} a monovalent radical which is the same or different and consists of a hydrogen radical or alkyl radical with 1 to 6 carbon atoms,
R ₃ is a polyether radical with the general formula - (F) (O (C _x H _2x O) _r Z) _g with the stipulations
g ≥ 1
x = 2-4
r> 1,
Z is an H atom or a monovalent organic radical, and F is a (g + 1) -bonded hydrocarbon radical.

Prefers is b at least 45%, where d is between 0 and 45%.

object the invention is also the use of these organopolysiloxanes for defoaming liquid Fuels.

The polyether radical R ¹ is the essential new function in the polyorganosiloxane according to the invention, since it is composed exclusively of polypropylene oxide units, which surprisingly gives the complex properties sought for fuel defoamers.

In the radical R ¹ , k is preferably 3, n is preferably 30 and R is preferably hydrogen or an alkyl radical having 1 to 3 carbon atoms, in particular a CH ₃ group.

In the radical R ² , R ^{u is} a divalent radical which is composed of one or more of the hydrocarbon radicals which are optionally substituted. An alkyl radical having 2 to 6 carbon atoms is preferred. An alkyl radical with 3 carbon atoms is particularly preferred.

The radical R ^v is a monovalent radical which is the same or different and is selected from the groups alkyl radical having 1 to 6 carbon atoms, alkoxy radical or hydroxy radical. Methyl radicals, the hydroxyl radical and alkoxy radicals having 1 to 6 carbon atoms are preferred. The index z is a number from 0 to 4. The number 0 or 1 is particularly preferred for z.

The radical R ^w is a monovalent radical which is the same or different and is selected from the groups hydrogen or alkyl with 1 to 6 carbon atoms. The methyl or ethyl radical is preferred here as the radical.

Phenol and anisole derivatives are preferred for R ² . Examples of corresponding phenol derivatives are allylphenol and eugenol (4-Al1yl-2-methoxyphenol), which are particularly preferred. Estragol (4-allylanisole) is an example of corresponding anisole derivatives, which is likewise particularly preferred.

R ³ is an aromatic-free polyether radical in which F is preferably propyl, g = 1 and r = 16.

The The value x is preferably between 2 and 4, with a copolymer from EO, PO and BO units.

The Polyethers arise from the addition of monomers, such as ethylene oxide, Propylene oxide or butylene oxide, to a starting alcohol, such as allyl alcohol. Such oxyalkyl chains can be statistically arranged or have a block structure.

Preferred radicals R ³ are polyether radicals which are built up from the addition of ethylene oxide and butylene oxide units to allyl alcohol.

The presence of the radical R ³ is not absolutely necessary (d = 0%), but permits fine-tuning of the properties with regard to compatibility and defoaming effect.

The residues can be in the molecule of the polysiloxane by adding allyl or vinyl derivatives to SiH groups of the polysiloxane in the presence of a hydrosilylation catalyst, e.g. B. according to the method of US-A-5 334 227 , are introduced.

The essence of the present invention is in particular that organofunctionally modified polysiloxanes are used which have the radical R ¹ . This radical R ¹ , which is a polyether composed of propylene oxide units, reduces the silicon content of the defoamer due to its high molecular weight and its high proportion in the molecule. At the same time, thanks to its compatibility in diesel, this polyether stabilizes the incompatible high-molecular polydimethylsiloxane chain. By choosing the two radicals R ² and R ³ , it is possible to optimize the compatibility of the defoamer and, at the same time, to achieve the optimal defoaming effect with optimal compatibility.

The to be used according to the invention Organofunctionally modified siloxanes can directly use diesel fuel be added. However, in practice it is preferred to use the defoamer add so-called additive package. About tolerance of the to be used according to the invention organofunctionally modified siloxane with the additive package it may be beneficial to mix the defoamer in a mixture of 2-ethylhexanol or glycols or aromatic solvents add. Depending on the foaming behavior of the diesel, the preferred one defoamer in the diesel between 2 - 8 ppm. The choice of defoamer concentration is independent of whether the defoamer is added directly to the diesel or via the additive package in the Diesel arrives.

Production of defoamer E1

A mixture of 12.8% SiH-functional polydimethylsiloxane (MD ₁₉₀ D ^H ₅₀ M, with 0.28% hydrogen) is initially charged with 20% aromatic-containing solvent. 52.1 of an allyl alcohol are added Teten copolymer, consisting of propylene oxide units, with a molecular weight of 1800 (PO poly ether). 1.3% of allylphenol and 8.8% of an allyl alcohol-initiated copolymer consisting of 12 ethylene oxide and 4 butylene oxide units (EO / BO polyether) are also added. The mixture is heated to 120 ° C. with stirring. 12 ppm of a platinum catalyst are added. The sales control by means of the SiH value gives 98% SiH conversion after 6 h. The product is mixed with 5 propylene glycol. The product contains 5% silicon.

Production of the defoamer E2

A mixture of 12.1% SiH-functional polydimethylsiloxane (MD ₁₉₀ H ₅₀ M, with 0.28% hydrogen) is placed in a 20% aromatic solvent. 57.5 of a copolymer started from allyl alcohol, consisting of propylene oxide units, with a molecular weight of 1800 (PO polyether) are added. Furthermore, 1.2% allylphenol and 4.2% of an allyl alcohol-initiated copolymer consisting of 12 ethylene oxide and 4 butylene oxide units (EO / BO polyether) are added. The mixture is heated to 120 ° C. with stirring. 12 ppm of a platinum catalyst are added. The sales control by means of the SiH value gives 97% SiH conversion after 6 h. The product is mixed with 5% propylene glycol. The product contains 4.7% silicon.

defoaming

to exam of the defoaming power of the siloxanes according to the invention become the defoamers solved in an additive package of the prior art. The Additive package is used according to the specification with 388 ppm in diesel. The diesel defoamer is added to the additive package at 8 ppm beforehand. Since the defoamer E1 Contains 5% silicon, the diesel fuel contains only 0.4 ppm silicon. This here used diesel contains 350 ppm sulfur.

As Comparison will be the commercial one defoamers TP 5851 (silicone polyether copolymer, from Goldschmidt) and the defoamer TP 325 (OSI) also tested, which according to the state of the art from an EO-containing Polyether and is made of eugenol. The Si content is approximately 9.8 %.

Ergebnisse im feuchten Diesel (Diesel wurden 250 ppm Wasser zugesetzt)

The foam disintegration of the diesel mixed with additive and defoamer is tested in a pressure apparatus (BNPé test). Results of the defoaming tests (blank value is a diesel and additive package without defoamer)

Results in wet diesel (250 ppm water added to diesel)

Claims (2)

Organofunctionally modified polysiloxanes of the general formula

where the sum a + b + c + d is between 200 and 350, the quotient a / (b + c + d) is a value between 3 and 5, the coefficient b is at least 35% and c is at least 10%, d is between 0 and 55% (in each case based on the sum (b + c + d), the radical R _{1 is} a polyether radical of the formula - (CH 2 ) k (OC 3 H 6 -) n OR is where R is a hydrogen or a monovalent organic radical, k is a number from 3 to 6, n is a number from 28 to 35, R _{2 is} a phenyl derivative having the general formula -R ^u - (C ₆ H ₄ -z R ^v z) -OR ^w wherein R ^{u is} a divalent radical which is composed of one or more hydrocarbons having 1 to 18 carbon atoms which are optionally substituted, R ^{v is} a hydroxy radical, an alkyl radical with 1 to 6 carbon atoms or an alkoxy radical with 1 to 6 carbon atoms and z is a number from 0 to 4, R ^{w is} a monovalent radical which is identical or different and consists of a hydrogen radical or alkyl radical having 1 to 6 carbon atoms, R _{3 is} a polyether radical having the general formula - (F) (O (C _x H _2x O) _r Z) _g with the provisos g ≥ 1 x = 2–4 r> 1, Z is an H atom or a monovalent organic radical and F is a (g + 1) -bonded, optionally branched hydrocarbon radical. Use of organofunctionally modified polysiloxanes according to claim 1 for defoaming of liquid Fuel, especially diesel fuel.