GB2155004A - Improvements in or relating to organic compounds - Google Patents

Abstract

A stable silicone-free antifoaming agent comprises (a) di-stearoyl ethylene diamine or a related compound, (b) a polyethylene wax, (c) hydrophobic silica, (d) a mixture of a natural hydrocarbon oil and vegetable oil and (e) a mixture of non-ionic emulsifiers with an average HLB value of from 6 to 12. The antifoaming agents are particularly useful in aqueous textile treatment liquors under HT conditions.

Description

SPECIFICATION Improvements in or relating to organic compounds The present invention relates to silicone-free anti-foaming compositions.

It is highly desirable to use silicone-free anti-foaming agents in HT textile finishing processes to avoid the spotting of the goods with silicone oil. Such spots cannot easily be washed off without damage to the goods. However, although many known silicone-free agents have good anti-foaming properties at low temperatures or even at 98 to 1 00 C, under HT conditions, particularly those in jet dyeing machines, they are ineffective or insufficiently active. A further desirable property of the anti-foaming agent concerns its stability when dispersed in water, particularly in hard water, to avoid any use restriction.

According to the present invention, there are provided stable silicone-free anti-foaming compositions which are particularly active under HT conditions.

The present invention provides a silicone-free antifoaming composition comprising a) a compound of formula I R-CO-NH-A-NH-CO-R (I) in which each R, independently, a saturated or unsaturated aliphatic hydrocarbon group having from 13 to 21 carbon atoms unsubstituted or substituted by one hydroxyl, and A is a straight alkylene chain having from 2 to 6 carbon atoms b) a polyethylene wax having a melting point of at least 80 C and an average molecular weight from 1,000 to 20 000; c) a hydrophobic silicagel d) a silicone-free, water immiscible oil mixture of d,) a natural hydrocarbon oil; and d2) a natural vegetable oil each liquid at 20 C and each having a boiling point of at least 1 00 C; and e) a mixture of e1) a non-ionic emulsifier having an average HLB value of from 6 to 10; and e2) a non-ionic emulsifier having an average HLB value of from 1 0.1 to 12, components a), b) and e) being dissolved or dispersed, and component c) dispersed, in component d).

Compounds of formula I are known, and are described for example in J. Org. Chem. 20 (1955), 695-699 or Chapter 7, Vol. 1 of ''Industrial Waxes" by H. Bennett (Chemical Publishing Company Inc., N,Y., 1 975).

The two groups R are preferably identical and are preferably alkyl or alkenyl or a mixture of alkyl and alkenyl, optionally substituted with one hydroxy group, derived from fatty acids, such that the group R-CO- is myristoyl, palmitoyl, stearoyl, oleoyl, ricinoleoyl or behenoyl, preferably palmitoyl, oleoyl, behenoyl and stearoyl, particularly palmitoyl and stearoyl.

Preferred compounds of formula I are those of formula la R'CONH-(-CH2-)-n, NHCOR' (la) in which n' is 2 or 3; and both R' are identical and are C16 18alkyl or C15#18alkenyI or a mixture thereof.

Preferably n' is 2.

Preferred polyethylene waxes are those prepared by the Ziegler synthesis and having a m. p.

in the range 80 to 1 40 C, particularly 90 to 1 30=C, more preferred those having a m. p.

> 11 O'C,-especially 110 to 130 C.

The hydrophobic silica of component c) is preferably one obtained by surface treatment of a colloidal silica of large surface-volume ratio. Surface treatments giving rise to hydrophobic properties are well known and include treatment with fatty alcohols, hydrocarbons, silicone oil or other organosilicon compounds, waxes or fatty amines. It is to be noted that surface treatment of component c) with a silicone does not give rise to any free silicone in the composition of the invention and that a composition according to the invention containing silicone-surface treated silica is still to be regarded as silicone-free.

The finely-divided silica which is rendered hydrophobic by surface treatment is preferably "fume silica" obtained by pyrolysis; a silicic acid gel dehydrated without loss of structure; or a precipitated silica obtained by aqueous chemical reaction.

It preferably has a specific surface area of 50-600 m2/g, which remains the same after treatment to give hydrophobic properties.

The silicone-free oils of component d) preferably have a flame point of at least 60 C.

Natural hydrocarbon oils suitable for use as component d1) include those obtainable by distillation of crude oil, bitumen and coal, for example: heavy petroleum or naphtha, boiling range 100-180"C (C810); kerosene or paraffin, boiling range 180-230 C, (C,112); gasoil, boiling range 230-305 C, (C1317); light lubricating oil, boiling range 305-405 (c1825); heavy lubricating oil, boiling range 405-515 C (C2838); isoparaffins, boiling range 100-250 C; alkyl aromatics, obtained by catalytic reforming of crude oil, boiling range 190-300 C; oil from low temperature coking of lignite or other bituminous material.

Preferably the oil has a boiling point above the temperature at which the antifoaming agent is intended to be used, preferably above 160 C, more preferably above 200 C. Particularly preferred are gasoil, lubricating oils and high-boiling isoparaffins.

Suitable vegetable oils for use as component d2) are predominantly fatty acid triglycerides, which are normally complex mixtures of different triglycerides, each of which may be a triester of two or three different fatty acids. The ester-forming fatty acids may be saturated or unsaturated, and may be substituted by one hydroxyl group. As examples of saturated monobasic fatty acids and of the corresponding oxy acids there may be given n-caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, oxystearic acid, arachidic acid, behenic acid and lignoceric acid. Examples of unsaturated glyceride-forming fatty acids are those containing from 10 to 24 carbon atoms, e.g. palmitoleic acid, oleic acid, elaidic acid, petroselenic acid, gadoleic acid, erucic acid, linoleic acid, linolenic acid, stearolic acid and ricinoleic acid.

Suitable vegetable oils which contain glycerides of the above-mentioned fatty acids include coconut oil, linseed oil, palm oil, olive oil, castor oil, peanut oil, rape seed soil, sesame oil, cottonseed oil, corn oil, soya oil, safflower oil, sunflower oil and wood oil. Of these, corn oil, rape seed soil and peanut oil are preferred.

Preferably component d2) of the composition of the invention is a vegetable oil in which at least 40 %, preferably at least 70 % of the glyceride-forming fatty acids are ethylenically unsaturated fatty acids of at least 18 carbon atoms, particularly oleic, linoleic, linolenic and erucic acids. Particularly preferred are oils in which the ester-forming unsaturated fatty acids are a mixture of monoethylenically unsaturated acids and diethylenically unsaturated acids.

The weight ratio of component d,) to component d2) is preferably 3-1 :1.

Preferably component d) is a mixture of oils containing as component d1) lubricating oils and as component d2) corn oil and/or peanut oil.

In the absence of added water, the composition according to the invention comprises a continuous phase of component d) in which components a) and b) are dissolved or dispersed and component c) dispersed, as finely as possible. Calculated as a percentage of the total weight of components a), b), c) and d), the concentration of each of components a) and c), considered separately and independently, is preferably 1-8 %, more preferably 2-6 %; the concentration of component b) is preferably 0.5 to 8 %, more preferably 1 to 5 %.

Suitable non-ionic emulsifiers as component e) include; polyalkylene glycols, especially ethylene oxide (EO)/ propylene oxide (PO) copolymers; alkoxylation products of higher fatty alcohols or fatty acid am ides; polyethylene glycol esters of long chain fatty acids; polyglycol derivatives in which one OH group is esterified or etherified with a long-chain acyl or alkyl group and the other with a short chain acyl or alkyl group; fatty acid esters of polyfunctional alcohols, e.g. glycerol, mannitol and sorbitol, their cyclic ethers and their polyaddition products with EO and/or PO; hydroxyalkyl fatty acid amides and their alkylene oxide adducts; oxyalkylated mono- and dialkyl phenols.

Preferred non-ionic emulsifiers e) are ethoxylated mono-, di or triesters of sorbitol with acids R,-OH, and/or compounds of formulae ll to V: R1~(~O~CH2~CH2~)m~O~R2 (II)

Rs-(-O-CH2-CH2-)q-OH (IV)

where R1 is the acyl group of a C1218fatty acid; R2 is hydrogen or the acyl group of a C1218fatty acid; R3 is C8#12aIkyI; R4 is hydrogen or C8#12aIkyl; R5 is a primary or secondary Cg 18alkyl or Cg 18alkenyl group; m is 4-10 p is 3- 12 q is 2-15 and r and s are each at least 1 and r + s is 2-15.

Of the above, the compounds of formulae ll, Ill and IV and the ethoxylated sorbitol esters are preferred. Particularly preferred are the compounds of formula II and Ill and the ethoxylated sorbitol esters.

Preferred emulsifiers as component e1) are the compounds of formula II, particularly those in which m is 4 to 8, more preferably 5 to 7, and R1 and R2 are each C18#18acyl. Preferred emulsifiers as component e2) are the compounds of formula Ill, particularly those in which p is 3 to 8, more preferably 4 to 7, and R4 is hydrogen, and/or the ethoxylated sorbitol esters.

in the composition of the invention, the emulsifier e,) has preferably an average HLB value of from 6.5 to 8. The emulsifier e2) has preferably an average HLB value of 10.1-11. Although the emulsifiers e,) and/or e2) may be each a single compound, they are each preferably present in the form of a mixture of compounds. The emulsifier e,) of formula 11 is preferably a mixture of mono- and diesters or partial esters having an esterification degree between 1 and 2.

Preferably the concentration of total emulsifier e), based on a) + b) + c) + d) + e) = 100, is from 7 to 30 %, particularly from 10 to 25 %. The weight ratio of emulsifier e,) to emulsifier e2) is conveniently from 0.2 to 2, preferably 0.4 to 1.2.

It has been found that the composition a) + b) + c) + d) + e) not only has good anti-foaming properties but also surprisingly an improved stability when diluted with water and even with hard water. The compositions of the invention are readily dilutable with water. They can be mixed with an amount of water which is from 70 to 95 % by weight of the total weight of the aqueous composition, preferably from 80 to 90 %, to produce the so-called stock dispersions.

Such dispersions are in the form of an oil-in-water emulsion and may be further dispersed in water for use as anti-foaming agents in aqueous systems.

The compositions according to the invention are pourable liquids at room temperature with a rotary viscosity of 5 to 5,000 cp at room temperature.

The compositions may be prepared by simple mixing together of the components. A preferred sequence of operations is that component b) is dissolved or dispersed in an oil d,), component a) is separately dissolved or dispersed in an oil d2) then both oil solutions or dispersions are mixed together and components cl), e,) and e2) and optionally further oil d,) are added. The resulting composition is ready to be diluted in water.

The antifoaming compositions of the invention may be added to aqueous systems having a tendency to foam, and in which foam formation has not yet occurred, in order to prevent or inhibit the formation of foam. They may also be added to foam-containing aqueous systems in order to wholly or partially destroy the existing foam and/or to limit or prevent any further foaming.

Aqueous systems having a tendency to foam occur in many technical processes, for example in the preparation of latexes, adhesives, starches, cellulose and sugar; during the work-up of aqueous sludges, particularly in sewage treatment or in the flotation of mineral ores, or of dispersable waste material; during manufacture of paper and non-woven fabric, particularly in high-speed machines; and in the presence of aqueous systems containing foam-generating components; e.g. polymer dispersions, acrylic resins, leather treatment liquors such as defatting liquors, textile treatment liquors (particularly baths containing dye or optical brightener together with surfactant), and paper coating systems.

The preferred application is foam inhibition in aqueous textile treatment liquors, which may be applied to the goods at any stage of treatment, including sizing, pretreatment, optical brightening, dyeing or printing, crease-resistant finishing and other aftertreatment operations.

The term 'textile' is used broadly to cover all stages of manufacture including loose fibres, filaments, threads, yarns, hanks, spools, woven, knitted or tufted fabric, felts, carpets, and semifinished or fully finished goods. The nature of the textile fibres (natural, synthetic or semi synthetic) is immaterial.

Such liquors may be applied by any conventional process, e.g. padding, or exhaust at normal or high pressure. The compositions of the invention are particularly suitable for use in textile treatment liquors to be applied under pressure in closed vessels, particularly under HT conditions, that is, at temperatures above 100 C, preferably 102-160 C, more preferably 105-150 C. The compositions are particularly useful in winchbecks and especially in highspeed equipment such as jet dyeing machines, in which there is a high tendency to foam because of steam formation and rapid motion of the goods and liquor, and a tendency for foam to expand when the pressure is released.

The treatment liquors may contain various types of treatment agents, e.g. sizes, fibre conditioning agents, desizing agents, detergents, bleaches, wetting agents, resin treatment systems. softening agents, antistatic agents, optical brighteners and dyestuffs; as well as dyeing auxiliaries such as carriers, levelling agents and dispersing agents. The compositions of the invention are particularly useful when the aqueous liquor contains treatment agents or auxiliaries which promote foam formation, and bring about an effective reduction in foaming without adversely affecting the treatment of the substrate. Particularly preferred is the use in dyebaths containing disperse dyes, particularly under HT conditions.

The composition of the invention may be added as such or after dilution with water, e.g. in the form of a stock dispersion, to the aqueous treatment liquors, at the beginning of the treatment and/or during the treatment.

The concentration of the composition according to the invention (calculated on the basis of components a), b), c), d) and e) in the aqueous system is preferably at least 0.0001 g/l. The optimum concentration for a given system will vary considerably depending on the nature of the system, the process conditions, the particular composition used and the desired effect, but may readily be determined by a simple test. The preferred concentration of the water-free composition in the aqueous system is preferably 0.0001-5 g/l, preferably 0.001-1 g/l; however in paper coating systems it is preferably from 0.0001-0.1 g/kg, more preferably 0.0001-0.01 g/kg.

The following Examples, in which all parts are by weight, and all temperatures are in degrees Centigrade, illustrate the invention.

Example I (i) Preparation of N'N,-distearoyl ethylenediamine dispersion 30.8 Parts of N'N-distearoyl ethylenediamine and 123.0 parts of peanut oil (D2) are heated with stirring under vacuum until a clear homogeneous solution is obtained. The resulting solution is added, with stirring and under vacuum (30-60 mbar) to 11 9.8 parts of the same oil at room temperature. A dispersion is formed, which is cooled to room temperature.

(ii) Preparation of polyethylene wax dispersion 21.4 Parts of polyethylene wax (Bt) and 213.9 parts of mineral oil (D1) are heated until a clear solution is obtained. The heating is stopped and the solution is cooled to room temperature while stirring. A fine dispersion is formed.

(iii) Preparation of final product To the resulting polyethylene wax dispersion produced under (ii) above are added 273.6 parts of the dispersion product under (i) and then 29.8 parts hydrophobic silica (C,). As soon as the silica is fully dispersed, the pressure is reduced to 30-60 mbar and the mixture is vigorously stirred until a homogeneous fine dispersion is formed. Thereafter the stirring speed is reduced, the vessel is purged with air and 316.1 parts of mineral oil (D,), 72.6 parts of emulsifier (E,) and 72.6 parts of emulsifier (E2) are then added. The product (1000 parts) is a fine mobile dispersion having the following composition: 3.1 % C"H35-CO-NH-(CH2)2-NH-CO-C,7H35 2.1 % polyethylene wax (B1) 3.0 % hydrophobic silica (C,) 52.9 % mineral oil (D1) 24.3 % peanut oil (D2) 7.3 % emulsifier (E,) 7.3 % emulsifier (E2) (iv) Identification of starting materials Polyethylene wax (B,) molecular weight 2000-5000 specific gravity 0.92-094 m.p. 118-123 C water content < 0.3 % acid number 0 saponification value 0 Hydrophobic silica C, (Sipernat D,O, Degussa, derived from silica hydrogel) specific surface area (BET) 90 m2/g mean particle size 18 nm bulk density (DIN 53194) 100 g/l wt. loss on drying (DIN 55921) 3 % wt. loss on ignition (DIN 55921) 7 % pH in 5 % dispersion in 1:1 water/methanol (DIN 53200) 8.5 SiO2 content 98 % Na2O content 0.8 % SO, content 0.8 % retained on sieving (DIN 53580) 0.01 % Mineral oil (D,) a hydrocarbon mixture with the following specification: b.p. range at normal pressure 320-390 specific gravity 0.85-0.95 water content < 0.1% acid number < 1 aniline point 70-80 refractive index n2D0 1.483-1.486 iodine number 20-30 flame point 165 o Emulsifier (E,): A 1:1 molar mixture of C17H33Co-(-oC2H4-)65-o Co C17H33 and C,7H33CO-(-OC2H4-)65-OH having an average HLB value of 7.0.

Emulsifier (E2):

HLB value = 10.4 Example 2 To 20 parts of the above composition are added 80 parts of demineralized water at room temperature with stirring. A stable milky dispersion is obtained.

Example 3 By following the procedure of Example 2 but using 80 parts of water with 20 dH, there is obtained a milky dispersion which is stable for at least 12 hours at room temperature.

Example 4 10 Parts of polyoxyethylene 20-sorbitol-triolate (HLB value = 11.0) is added with stirring to 100 parts of the dispersion obtained in Example 1.

In the following Application Examples, the composition of Example 1 is used in the form of the aqueous dispersion of Example 2.

Application Example A Prewashed polyester fabric (Dacron T 54-5-761) is dyed in a jet dyeing machine of volume 1200 ml with 600 ml of an aqueous dye liquor of the following composition: 5% (based on wt. of substrate) C.l. Disperse Red 167 1 g/l levelling agent (C,618 fatty alcohol condensed with 30 moles EO, iodine number = 55) 1 gel dispersing agent (Turkey red oil) 2 g/l ammonium sulphate formic acid to pH5 0.65 g/l composition of Example 1.

The goods: liquor ratio is 1:20 and the liquor circulation rate is 1.5 I/min. The liquor is heated from 30 to 1 30' over 30 minutes, at 80 the apparatus is closed and pressurised with air to 1 atm. excess pressure. On reaching 1 30', dyeing is continued at this temperature for 60 min., then the liquor is cooled and the pressure is released when the temperature has fallen to 85 . Significantly less foam is produced than in the absence of the composition of Example 1.

Application Example B Application Example A is repeated with the following differences. The liquor contains 0.5 g/l levelling agent but no dispersing agent. The goods: liquor ratio is 1:25 and the circulation rate 1.9 g/l. The bath is heated from 30 to 1 30' over 50 min. and held at 1 30' for 30 minutes before cooling. Significantly less foam is produced than in the absence of the composition of Example 1.

Application Example C Cotton cretonne is dyed in the same jet dyeing machine as in Example A, using the following dye liquor (600 ml) 10% (based on substrate) C.l. Reactive Blue 116 60 g/I Glauber's salt 20 g/l soda 0.75 g/l composition of Example 1 at a goods/liquor ratio of 1:20 and circulation rate of 1.5 I/min. The liquor is heated from 30 to 60 over 30 minutes, held at 60 for 60 minutes then cooled to 40 . The amount of foam produced is significantly less than in the absence of the composition of Example 1.

Application Example D Wool gabardine is dyed in the apparatus used in Example A with 600 ml of the following liquor: 1.0% (based on substrate) C.l. Acid Black 52 0.5 g/l levelling agent of Example A 10.0% (based on substrate) conc. sulphuric acid and 0.5 g/l composition of Example 1 at a goods/liquor ratio of 1 :20 and circulation rate of 1.5 I/min. The liquor is heated from 30 to 98'over 30 minutes, held at 98 for 60 minutes, then cooled to 40 . Foam formation is significantly less than when the composition of Example 1 is omitted.

Application Example E A paper coating paste is made up of the following composition; 26.73% kaolin 0.05% sodium tripolyphosphate 0.01% sodium polyacrylate 0.03% caustic soda 5.35% Dow-Latex 620 67.83% water and 0.02% composition of Example 1 (based on the weight of kaolin) is added. The product is tested on the apparatus described in "Wochenblatt fur Papierfabrikation", 104, 117-8 (1976), No. 3 (H. Pummer). Foam formation in the coating paste is considerably reduced by the presence of the composition of Example 1.

Application Example F Polyester fabric is dyed under HT conditions in a Gaston County Mini-Jet machine of capacity 650 1 (30 kg substrate), using a dye liquor with a particularly high tendency to foam formation.

Substrate: polyester, prewashed and prefixed, 17 kg = 260 m Dye liquor: 450 I demineralized water containing: 0.95 % (based on substrate) C.l. Disperse Red 167 1 g/l levelling agent of Example A 1 gel dispersing agent of Example A 2 g/l ammonium sulphate 200 ml formic acid (to pH 5) 0.65 g/l product of Example 1 Goods: liquor ratio 1:26, goods velocity 75 m/min. Heated 60-126 over 2 hours, kept at 1 26' 30 minutes, cooled 126 -60 over 30 minutes. No foam formation was observed over the entire process. Inspection of the dyed goods showed no spots or uneven areas due to the antifoaming agent.

Application Example G Polyester piece goods are dyed in a Then-Softlow-Jet machine under HT conditions.

Substrate: smooth round-knitted Tergal goods, 130 g/m2, 110 dtex, 30z15, 9.1 kg.

The machine is filled with cold tap water, 5 dH, liquor to goods ratio 1 :15. While heating to 50 , the following additions are made in the given order: 0.2 g/l product of Example 1 2.0 g/l monosodium phosphate 1.4 g/l of the product of Example 14 of USP 4, 186, 119 1.0 g/l Turkey red oil.

On reaching 50 , 0.05% C.l. Disperse Orange 30 is added and the pH adjusted to 5.2 with acetic acid. The temperature is raised at 1 '/min to 90 and 4'/min to 1 30' and kept at 130 for 30 minutes before cooling to 50 , discharging the spent liquor and giving one cold rinse.

No foam formation could be observed during the dyeing process.

The composition of Example 1 may also be used in the form of the aqueous dispersion of Example 3 in the processes of Application Examples A-G. The same good results are obtained.

Similar good results are obtained when the composition of Example 1 is replaced by the composition of Example 4 added in the form of an aqueous dispersion as disclosed in Example 2.

Claims (26)

1. A silicone-free antifoaming agent comprising a) a compound of formula I R-CO-NH-A-NH-CO-R (I) in which each R, independently, a saturated or unsaturated aliphatic hydrocarbon group having from 13 to 21 carbon atoms unsubstituted or substituted by one hydroxyl, and A is a straight alkylene chain having from 2 to 6 carbon atoms b) a polyethylene wax having a melting point of at least 80 C and an average molecular weight from 1,000 to 20 000; c) a hydrophobic silicagel d) a silicone-free, water immiscible oil mixture of d1) a natural hydrocarbon oil; and d2) a natural vegetable oil each liquid at 20 C and each having a boiling point of at least 100 C; and e) a mixture of el) a non-ionic emulsifier having an average HLB value of from 6 to 10; and e2) a non-ionic emulsifier having an average HLB value of from 1 0.1 to 12, components a), b) and e) being dissolved or dispersed, and component c) dispersed, in component d).

2. An antifoaming agent as claimed in Claim 1 in which component a) is of formula la R'CONH-(-CH2-)#NHC0R' (la) in which both R' are identical and are alkyl or alkenyl with 16-18 carbon atoms or a mixture thereof and n' is 2 or 3.

3. An antifoaming agent as claimed in Claim 2 in which component a) is N,N'-distearoyl ethylene diamine.

4. An antifoaming agent as claimed in any one of the preceding claims in which component b) is a polyolefin wax having a m.p. in the range 90-130 C.

5. An antifoaming agent as claimed in any one of the preceding claims in which component d,) is selected from gasoil, lubricating oils and high-boiling isoparaffins.

6. An antifoaming agent as claimed in any one of the preceding claims in which component d2) is a vegetable oil in which at least 40% of the glyceride-forming fatty acids are ethylenically unsaturated fatty acids of at least 18 carbon atoms.

7. An antifoaming agent as claimed in claim 6, in which component d2) is selected from corn oil, rape seed oil and peanut oil.

8. An antifoaming agent as claimed in any one of the preceding claims, in which the weight ratio of component d1) to component d2) is 3-1:1.

9. An antifoaming agent as claimed in any one of the preceding claims, in which the emulsifiers e) are selected from ethoxylation products of sorbitol mono-, di- or triesters with acids R,OH and compounds of formulae 11 to V: R,-(-O-CH,-CH,-),-O-R2 (II)

R5-(-O-CH2-CH2-)q--OH (IV)

where R, is the acyl group of a C,2,8 fatty acid; R2 is hydrogen or the acyl group of a C,218 fatty acid; R3 is C812 alkyl; RA is hydrogen or C8,2 alkyl; R5 is a primary or secondary Cg l8 alkyl or Cg t8 alkenyl group;; m is 4- 10 p is 3- 12 q is 2-15 and r and s are each at least 1 and r + s is 2-15.

10. An antifoaming agent as claimed in Claim 9, in which the emulsifier e1) is a compound of formula II.

11. An antifoaming agent as claimed in Claim 10, in which the emulsifier el) is a compound of formula II in which m is 4 to 8 and R, and R2 are each C16,8 acyl.

12. An antifoaming agent as claimed in any one of Claims 9 to 11, in which the emulsifier el) has an average HLB value from 6.5 to 8.

13. An antifoaming agent as claimed in Claim 9, in which the emulsifier e2) is a compound of formula Ill and/or an ethoxylated sorbitol ester.

14. An antifoaming agent as claimed in Claim 13, in which in the compound of formula Ill p is 3 to 8 and RA is hydrogen.

15. An antifoaming agent as claimed in any one of Claims 9 to 14 in which the emulsifier e2) has an average HLB value from 10.1 to 11.

16. An antifoaming agent as claimed in any one of the preceding claims, containing from 7 to 30% of the total emulsifier e), based on a) + b) + c) + d) + e) = 100.

17. An antifoaming agent as claimed in any one of the preceding claims, in which the weight ratio of emulsifier e1) to emulsifier e2) is from 0.2 to 2.

18. An antifoaming agent as claimed in any one of the preceding claims, containing from 70 to 95% by weight of water based on the total weight of the aqueous antifoaming agent.

19. An antifoaming agent as claimed in Claim 1, as described in any one of Examples 1 to 4.

20. A process for the preparation of an antifoaming agent as claimed in any one of the preceding claims, comprising the step of mixing together a solution or dispersion of a) in d2), a solution or dispersion of b) in d,) and c), e1) and e2).

21. A process for the reduction of foaming in aqueous systems, characterised by the addition of an effective amount of an antifoaming agent as claimed in any one of Claims 1 to 1 9 to the aqueous system.

22. A process as claimed in Claim 21 in which the aqueous system is a textile treatment liquor.

23. A process for textile treatment under HT conditions, characterised in that an effective amount of antifoaming agent as claimed in any one of Claims 1 to 19 is added to the treatment liquor.

24. A textile treatment liquor containing 0.0001-5 g/l of an antifoaming agent as claimed in any one of Claims 1 to 19, calculated on the basis of components a), b), c), d) and e).

25. A dyebath containing a disperse dye and from 0.001-1 g/l of an antifoaming agent as claimed in any one of Claims 1 to 19, calculated on the basis of components a), b), c), d) and e).

26. A process for the reduction of foaming in aqueous systems as claimed in Claim 21, as described in any one of Examples A to G.