SE451382B - VIEW TO Cushion Foam Formation in an aqueous liquid with the help of a foam dampening composition - Google Patents

Description

451 582 2 with a foaming tendency by adding to the liquid a defoamer 1 an amount which effectively eliminates or reduces the foam, the defoamer comprising a polyether chain consisting essentially of a polyethylene oxide (EO) block residue or a condensate having a poly-bonded poly-one end. , 2-propylene oxide (PO) block residue with hydroxyl in the end position, the remaining end of the poly (EO) residue being an organic hydrophobic moiety or hydrophobic. In order to achieve the favorable defoamers which can be obtained according to the invention, the hydrophobic 1 must generally constitute about 3 to about 50% by weight of the defoamer, the remainder being the polyether chain described above. Furthermore, the PO / EO ratio in the polyether chain is generally greater than 1: 1 and preferably about 3: 1. The defoamer is generally conveniently dissolved or dispersed in a carrier which may be inorganic, such as water, or organic, such as mineral oil.

According to a preferred embodiment of the invention, the aqueous liquid is constituted by the process stream in a paper or pulp mill, the foaming due to the presence of wood resins, lignin sulfonates, surfactant process or stock additives and mechanically induced air entrainment. According to another preferred embodiment of the invention, the above-mentioned liquid antifoam material also comprises a contributing amount of a mono-, di- or triester of a phosphorylated fatty alcohol or synthetically produced alcohol.

According to a further embodiment of the invention, the defoaming material described above also contains a wax-like material, such as pentaeryl tritol tetrastearate. Such a wax-like material has previously been used in a defoaming material and has been found to be particularly useful.

The term "attenuation" is intended to include any improvement or protection measures that may be taken to eliminate the problems arising from excessive foaming. "Attenuation" is specifically intended to include the breakdown or reduction of foam or the prevention of foaming as well as the reduction or elimination of the amount of entrained air. By reducing or eliminating the amount of air entrained (which can take up to about 15% by volume 451 382 .3. Of the process stream, which is subjected to heavy mechanical agitation), one thus increases the efficiency of the process even though one can not notice with the naked eye any change in the amount of surface foam before and after the addition of the defoamer according to the invention. By a "hydrophobic" or "hydrophobic moiety" in this context is meant single-use radicals, mainly hydrocarbon radicals, which are substantially insoluble in water and generally have a molecular weight in the range of from 100 to 350. As will be discussed in more detail below. suitable hydrophobic moieties include molecular moieties of alkylphenols and high molecular weight saturated or unsaturated alcohols or mixtures thereof.

When applying the method of the invention for reducing or degrading foams in aqueous media, the materials described herein are mixed with the potentially or in fact foaming aqueous material (in a suitable ratio) in virtually any desired or suitable manner. The materials can be poured or sprayed onto the foaming liquid or added in another way or placed on top of the liquid, thereby reducing or removing the foam therefrom.

Addition of the materials in question to a liquid underlying the foam already formed is another method encompassed by the invention.

The drawing shows a triangular coordinate system which indicates the foam height measure as a function of the composition of the defoamer.

The defoamers which can be used according to the invention comprise non-ionic polyethers with a polyethylene oxide condensate residue or block (-OC 2 H 4 -) x bonded to a poly-1,2-propylene oxide condensate block or residue with hydroxyl in terminal position, (-OCBHÉ-) yOH, the remaining end of the polyethylene oxide segment being attached to a relatively hydrophobic organic moiety, such as an alkylphenol, high molecular weight alcohol or a mixture thereof. The defoamers of the invention may be represented by the formula: R1 - (OC2Hu) x- (OC3H6) y-OH I wherein R1 is a monovalent organic hydrophobic moiety or hydrophobic 451 382 which is preferably selected from the group consisting of primary or secondary alcohols having long chain or high molecular weight, alkylphenols or mixtures thereof; x is the average number of moles or units of ethylene oxide per molecule of defoamer and has a value in the range of 3 to 20; preferably 5 to 15; y is the average number of moles or units of propylene oxide per molecule of defoamer and has a value in the range of 15 to 60, preferably 20 to 50.

In order to achieve the favorable defoaming properties of the compositions of the invention, it has been found necessary that both the relative amounts and the relative positions of the EO and P0 segments be those set forth herein. Agents with the same relative amount of ethylene oxide and propylene oxide residues (ie, the same weight percent) in which the ethylene oxide and propylene oxide segments occur randomly are not useful as defoamers and are not included in the present invention. The invention thus relates to the use of a defoamer consisting of an organic hydrophobic, as described above, bound to a segment or "block" of repeating ethylene oxide units (as they would be obtained by ring-opening condensation of "x" moles of ethylene oxide to a chain) , which segment in turn is bonded to a second segment or block of repeating propylene oxide units (as would be obtained by condensation of "y" moles of 1,2-propylene oxide), the propylene oxide block having a hydroxyl group in the terminal position.

In the practical application of the invention, as stated above, very specific amounts of organic hydrophobic, EO and PO segments in the defoamer are required in order to achieve the favorable defoamer of the invention.

Especially when using a suitable alkylphenol hydrophobic (such as nonylphenol), it has been found that a particularly noticeable defoaming is achieved (in a paper mill environment) if the polyether chain has an average of 12.5 repeating E0 units, ie. an average of 12.5 moles, and that from 25 to 60 PO units should be added to the chain to produce the defoamer.

The crucial importance of the weight ratio hydrophobic / EO / PO 4s1 sszg 5 in damping foam due to the presence of other surfactants is shown in the accompanying drawing. The drawing shows in a triangular coordinate system the relatively narrow ranges of the defoamer which gives the defoamer property which can be obtained when applying the method according to the invention in its preferably used embodiment in a paper or pulp mill. On the different axes in the figure, the weight percent hydrophobic, the weight percent polyethylene oxide residue resp. weight percent poly-1,2-propylene oxide residue. The numbers within the delimited zones in the figure denote foam heights (1 inch), which are determined in the manner that will be described in the following.

Determination of the defoaming properties of the defoamers of the invention has been developed in connection with the advent of the present invention. With this test, it has proved possible to predict the defoaming ability of a certain defoamer in industrial process conditions that occur in practice (eg at a paper mill).

Foam height measurements were made after adding about 100 ppm of the defoamer to be tested to 3 liters of water at a temperature of 21 ° C in a 3-liter metal beaker whose temperature could be regulated. The defoamer was dissolved or dispersed in a suitable organic carrier, such as mineral oil, in a weight ratio of about 80% by weight of mineral oil of the particularly thin base oil type and 20% by weight of defoamer.

The total defoamer thus obtained a concentration of 500 ppm. The water in the beaker contained about ÉO ppm nonylphenol - E0 with an average of 9.5 moles E0 per nonylphenol core. This alkylphenol polyether is a high foaming surfactant commonly used in paper and pulp processes, especially when the cellulosic fiber is to be decolorized or purified simultaneously or at a later time. A transparent glass cylinder is arranged on top of the edge of the metal beaker so that it can accommodate foam formed in the metal beaker. The glass cylinder is equipped with an external vertical measuring stick for measuring the height of a foam column formed therein.

A spray nozzle of the "V-Jet" type with the designation 30/15 is arranged near the open end of the glass cylinder and directed into the metal cup. It is connected to a water pump with adjustable pressure. The water pump causes the contents of the beaker to circulate through the nozzle so that the concentration of the materials therein does not change. For the purposes described, the pump exerted a pressure of 42 kPa on the nozzle. Shortly after starting up the pump, the foam height in the glass cylinder assumes an equilibrium position, and this Equilibrium foam height is characteristic of the defoamer tested.

After starting the pump, the foam height was measured once a minute for 15 minutes. The average of these 15 foam heights was then determined. Acceptable foam cushioning for the purposes according to the invention is an average foam height of about 13 cm or less over a 15-minute period. Zones with acceptable foam attenuation are shown in the figure and are within the range marked 4 "- 5". By way of comparison, under the above conditions, an aqueous solution of 50 ppm nonylphenol (EO) 9.5 but without any of the defoamers in question resulted in a foam height exceeding 23 cm within about 2 minutes, causing pump cavitation and pressure losses.

To further confirm the effectiveness of defoaming materials according to the invention, a separate series of experiments was performed with the defoamers in water (ie without the use of hydrocarbon carriers). It was found that the defoamers functioned well in an aqueous carrier, and the defoamer zones were similar to those presented in the figure. Since the organic mineral oil carrier is not necessary for the method according to the invention to be effective, the defoamers can be dispersed or dissolved in an organic or an aqueous carrier.

However, the defoamers did not work as well in water as in organic hydrocarbon carriers, as the defoamer in the organic medium was found to be less sensitive to small changes in the PO / E0 ratio. Organic materials such as naphthenic oils, mineral oils, paraffin oils and kerosene are thus the most suitable carriers. The preferred carrier for the defoamer is mineral oil, and the composition of the total defoamer should preferably be 80% mineral oil and 20% defoamer.

A particularly suitable class of defoamers is that in which they are alkylphenol polyethers. These alkylphenol-polyethylene oxide polypropylene oxides with hydroxyl in the terminal position are usually prepared from alkylphenol-polyethylene oxide. The alkylphenol-polyethylene oxides used as starting materials are a well-known class of surfactants which have long been used in many different industrial processes. Such conventional materials have the structure Q * °° 2 "4 * == '°" where H2 is a linear or branched, saturated or unsaturated, monovalent hydrocarbon radical having from 6 to 18 carbon atoms, preferably 8 to 12 carbon atoms, which could be represented by the homologous formula C Rz anza fl (it is most convenient that only one Ra is attached to the phenolic nucleus, but the invention also includes the alternative with several R2); x has a value from 3 to 20 (preferably 5 to 15) and each unit (-OC 2 H 2 -) is derived from the ring opening of ethylene oxide, also known as oxirane. Alkyl chains are sometimes referred to herein as "Ca". where "a" is the number of carbon atoms in the chain, such as C12 or Cl2-1, when a mixture of chains is meant. This symbol "Ca" thus represents any saturated or unsaturated, branched or linear hydrocarbon group containing "a" chelate atoms. When a saturated group is meant, "Ca" can be extended to the empirical formula for the group CaH2a + 1, for example C Hlg. A particularly suitable class of starting materials for the synthesis of alkylphenol polyethers are nonylphenol polyethylene oxides (NP-E0).

Nonylphenol polyethylene oxides useful in the invention are characterized by the presence of an alkyl chain having nine carbon atoms, which is attached to the aromatic nucleus (in the ortho, meta or para position relative to the polyether chain), a polyether chain having from 3 to 20 ethylene oxide units (ie x has a value from 3 to 20) and a hydroxyl group 1 end position. When the defoaming is to take place in a paper or pulp mill environment, x preferably has a value of 5 to 15, in particular 8 -l.

While such common nonylphenol polyethylene oxides can be prepared synthetically in relatively pure fractions having a rather specific value of x, they are generally marketed as mixtures of molecules with different values of x. These mixtures are characterized by their mean value of x. common material is thus NP-E09.5, which on average has 9.5 ethylene oxide units (moles) per nonylphenol core (x = 9.5). Nonylphenol polyethylene oxides with an average value of x from 3 to 20 are commercially available from various companies, such as the GAF Corporation under the trademark "Igepal", Rohm and Haas Company under the trademark "Triton" and Jefferson Chemical Company under the trademark "Surfonic".

According to the invention, hydrophobic polyethylene oxide moieties are used which are bonded at the distal end of the polyethylene oxide chain to a plurality of 1,2-polypropylene oxide units (-OC5H6-) Y, the polypropylene oxide chain preferably having a hydroxyl group in the terminal position. The structure of the defoamer thus has the formula I. It has been found necessary for the polyethylene oxide segment to be located adjacent to the hydrophobic group in order to achieve the favorable defoaming properties possible according to the invention.

The nonylphenol-polyethylene oxide-polypropylene oxides (NP- (EO) x- (PO) y-OH) provided with a hydroxyl group in the terminal position are prepared according to methods well known to a person skilled in the art. NP- (EO) x- (PO) -OH can be prepared, for example, by reacting NP- (EO) x (eg "Igepal" or "Triton") with propylene oxide at, for example, 10000 to 150 ° C, under an air pressure of 101 to # 04 kp (1 to 4 atm) in the presence of an alkaline catalyst, e.g. KOH. U.S. Pat. No. 3,021,372 discloses the preparation of the preferably used octylphenol and nonylphenol polyethylene oxide polypropylene oxides having a hydroxyl group terminated, and the contents of said U.S. Pat. No. are considered to be included in the present text. It is generally preferred that the catalyst used to prepare NP- (EO) x-OH not be removed prior to the addition of the P0 segments (ie, non-neutralized NP-E0 should be used).

Another suitable class of non-ionic surfactants which have been found to be useful in the invention are terminal hydroxylated ethylene oxide-propene oxide adducts having a hydrophobic high molecular weight or long chain alcohol, wherein the polyethylene oxide segment connects the high molecular weight alcohol moiety to the polypropylene oxide segment. The term "high molecular weight or long chain alcohols" means linear or branched, saturated or unsaturated, primary or secondary alcohols having from 6 to about 24 carbon atoms and having a molecular weight ranging from "about 75 to 300". sometimes referred to as fatty alcohols.

Nonionic surfactants prepared from the high molecular weight alcohols can be represented by the formula nj- (ocaua) x- (oc3H6) y-oH where R is a linear or branched, saturated or unsaturated monohydric alcohol residue (alkyl chain) having from about 6 to about 24 carbon atoms (preferably 10 to 18) and x and y have the meaning given above. Long chain hydrophobic fatty alcohol residues suitable for use in the invention include C10-14 alcohol blends, C18-18 alcohol blends and C14-18 alcohol blends.

As stated above, EO-PO addition products with high molecular weight alcohols provided with a hydroxyl group 1 reposition can be prepared by adding EO-PO polyether segments to alcohols with the desired carbon structure. The alcohols used herein may be synthetically produced alcohols (ie, alcohols prepared according to the well-known Zhegler method or carbonylation processes) or alcohols prepared by reducing naturally occurring fatty acids to fatty alcohols.

Suitable fatty acids as starting materials can be obtained from natural sources, such as coconut oil, palm oil, tallow, lard and pine oil, the length of the carbon chain and the structure of the alcohol are determined by the synthesis conditions or properties of the fatty acid used as starting material. Specific desired alcohol structures can, of course, be obtained from natural sources by distillation or the like or by the above-mentioned synthetic methods and subsequent distillation. Particularly suitable high molecular weight EO-PO addition products for use according to the invention are prepared synthetically by adding the polyether chain - (EO) 1,2,5- (PO) 50-OH to a mixture of alcohols with 16 and 18 carbon atoms. The hydrophobic in this embodiment can thus be represented by Cl6_18. According to another preferred embodiment of the invention, the above-mentioned liquid defoamer is mixed with mineral oil and it further comprises a contributing amount of a phosphorylated mono-, di- or triester of a fatty alcohol or synthetic alcohol. This ester has the following structure: o o I! Wherein R 1, R 5 and R 6 may be the same or different and represent monovalent, fatty acid-derived or synthetically produced, primary or secondary, saturated or unsaturated straight or branched chain alcohol moieties.

% The phosphorylated organic alcohol is prepared according to well-known methods for the preparation of phosphoric acid esters, the preferred organic alcohol moiety being C16-18. Other alcohol groups that may be used include C10-22, C20 + or mixtures thereof. The phosphorylated organic alcohol could thus suitably be mixed with the above-described defoamer and a carrier (eg mineral oil) and the mixture of defoamer, carrier and phosphoric acid applied in the same manner as for the defoamer alone.

According to a third suitable embodiment of the invention, the above-mentioned defoaming material is mixed with petroleum or a synthetic wax-like material. A particularly suitable wax-like material is a synthetic pentaerythritol tetrastearate which is not derived from petroleum. It should be emphasized in particular that this wax-like material should be used in addition to the above-mentioned defoaming material (with or without the phosphorylated alcohol) in regulating foaming. A particularly suitable material with the trademark Cyclochem PETS can be obtained from The Cyclo Chemical Company.

Various modifications and alterations of the invention will be apparent to those skilled in the art within the scope of the invention, and the invention is thus not limited to the embodiments and examples which have been set forth to illustrate the invention.

Example 1

In this example, illustrate the preparation of nonylphenol- (EO) x- (PO) γ-OH with a terminal hydroxyl group.

732 kg of nonylphenol are introduced into a flushable pressure vessel made of stainless steel with a volume of 7500 liters and equipped with agitators and a temperature-regulating mechanism. The nonylphenol is stirred for 10 minutes, while nitrogen gas is bubbled through it. 20 kg of potassium hydroxide are added to the nonylphenol, the reaction vessel is purged several times (eg 3 times) with nitrogen and left with a slight overpressure of N2. Thereafter, the contents of the reaction vessel are heated to 110 ° C, and at this temperature the reaction vessel is again purged with dry nitrogen and left with a slight overpressure of nitrogen. The heating of the reactants is continued to 120 ° C, after which the heating is stopped and the vessel is rinsed several times in the manner described above. About 1390 kg of ethylene oxide is introduced into the reaction vessel at a rate of between 19 and 45 liters per minute, the rate of ethylene oxide addition and heating or cooling of the reaction vessel being controlled so that the stirred reaction medium is kept at a temperature in the range of 143 ° C. 5 ° c. The pressure in the reaction mixture should be kept below 400 kPa during the addition of E0. Ethylene oxide is added until the nonylphenol-ethylene oxide reaches its cloud point in a 1% aqueous solution in the temperature range from 53 ° C to 58 ° C (ie in a 1% aqueous solution of the material the temperature at which the material begins to precipitate out of solution, showing itself through turbidity). After complete addition of EO, the mixture is reacted at 143 ° C for 15-50 minutes.

Then P0 is added until the cloud point in a 1% aqueous solution for a 20% diethylene glycol monubutyl ether solution of the E0-P0 addition product is 48 ° C - 5000. Continued addition of P0 further lowers the cloud point of the addition product.

After the addition of PO, the finished product is cooled to 79 ° C and 20.4 kg of glacial acetic acid are added to the product to neutralize the potassium hydroxide, after which the product is stirred for a further 451 582 '12' 50 minutes. This completes the synthesis of the defoamer nonylphenol- (EO) 9,5- (PO) 24-OH.

Nonylphenol is used for the synthetic preparation of a series of surfactants according to the invention with different amounts of EO and PO using a procedure analogous to that described above. The ability of these surfactants to inhibit foaming has been measured according to the test described above. The results are summarized in Table I (see next page) - Example 2.

For the purpose of comparing defoaming properties, a series of materials having the following composition of 1% by weight were prepared and tested. 1D 2.

C16-18 '(E °) 12,5' (P °) 13 '° H mineral oil of the type especially thin base oil nonylphenol- (EO) 12,5- (P0) 50-OH mineral oil of the type especially thin base oil water mineral oil of type especially thin base oil "Gantrez AN l49" x nonylphenol- (E0) 9.5- (PO) 5o-OH cl6_l8-oPo3H2 2o, o 80.0 2o, o 80.0 63.5 1o, o 1.5 2o, o 5, 0 x emulsion stabilizer consisting of a maleic anhydride copolymer, commodity from GAF Company mineral oil of the type especially thin base oil cyclohexanol nonylphenol- (EO) 12 5- (PO) 50-OH C16-18 ° C 3 H - (E0) 12,5-PO0 ° -OH Gantrez AN 149 sodium hydroxide 100 SUS naphthenic oil 75.0 10.0 10.0 5.0 58.2 4.0 1o, o 2.0 0.8 25.0 ß: 13 Table I C9H19 _ Condition Average value for weight percentage Foam height x / yxy NP E0 P0 twn cm .17 1 6 34.1 7.4 58.5 5.0 (12.7) .08 1 _ 12 21.5 4.7 73.8 6.0 (l5.2) .06 1 18 15.7 3.4 80.9 5.9 (14.9) .04 1 24 12.4 2.7 84.9 6.1 (15.4) .5 3 6 29.7 19.3 51.0 4.7 (11.9) .25 3 12 19.7 12.8 67.5 5.4 (13.7) .l7 3 18 14.7 9.6 75.7 5.3 (l3.4) .13 3 24 11.8 7.6 80.6 4.9 (12.4) 2.17 6.5 3 30.6 43.1 26.2 8 + (20.3 +) 1.08 6.5 6 24.3 34.2 41.6 7.8 (19.8) .72 6.5 9 20.1 28.3 51.6 7.2 (18.3) .54 6.5 12 17.1 24.1 58.7 5.5 (l3.9) .36 6.5 18 13.2 18.7 68.1 5.2 (13.2) .27 6.5 24 ~ 10.8 15.2 74.0 4.5 (1l.4) .22 6.5 30 9.1 12.8 78.1 4.25 (10.7) 1.58 9.5 6 20.9 43.1 35.9 8 + (20.3 +) .79 9.5 12 15.4 31.7 52.8 8 + (20.3 +) .53 9.5 18 12.2 25.1 62.7 8 + (20.3 +) .40 9.5 24 10.1 20.8 69.1 1.0 (2.5) .32 9.5 30 8.6 17.7 73.7 1.95 (4.9) .26 9.5 36 7.5 15.4 77.1 1.0 (2.5) .20 9.5 48 6.0 12.3 81.8 1.9 (4.9) .63 12.5 20 10.6 28.8 60.6 7.8 (19.8) .42 12.5 3 0 8.1 22.1 69.8 2.3 (5.8) .3l 12.5 40 6.6 17.9 75.5 0.5 (1.3) .25 12.5 50 5.6 15.1 79.4 0.3 (0.7) 2.5 15 6 16.8 54.5 28.7 8 + (20.3 +) 1.25 15 12 13.0 42.3 44.6 8 + (20.3 +) .83 15 18 10.6 34.6 54.7 8 + (20.3 +) .63 15 24 9.0 29.3 61.7 8 + (20.3 +) 5.0 30 6 10.8 70.6 18.6 8 + (20.3 +) 2.5 30 12 9.1 59.5 31.4 8 + (20.3 +) 1.67 30 18 7.9 51.4 40.7 8 + (20.3 +) 1.25 30 24 7.0 45.3 47.8 8 + (20.3 +) 0 loo "'_ 0 3 _0 60.6 39.4 0 - - 0 6.5 0 41.5 58.5 0 8 + ( 20.3 +) 0 9.5 0 32.7 67.3 0 8 + (20.3 +) 0 12.5 0 27.0 73.0 0 8 + (20.3 +) 0 15 0 23.5 76.5 0 8 + (20.3 +) 0 30 0 13.3 84.7 0 8 + (20.3 + ) d "W% (Example 1 2 continues on the next page.) 451 582 lä All defoaming tests were performed with 160 ppm of the material in the presence of from 100 to 600 ppm nonylphenol- (E0) -OH as surfactant with high foaming ability . The results of these comparisons are shown in Table II.

The numbers indicate the foam heights one minute after each additional addition of the high foaming surfactant.

Table II e Composition nonylphenol- (E0) 9 5-OH, ppm No. 100 200 300 400 500 600 Blind sample 8+ - - - - - I l - 'Tao 8: 0' '"2 1.0 §, O 6, 5 8.0 - - 3 5.15 8: 0 "" 4 0.5 1.0 2.0 3.9 6.5 7.5 5 a 0 0.5 1.0 1.5 '2.2 3.2 Foam height measurements according to Table II was made at 21 ° C and a pump pressure of 41 kPa It should be noted that the material with the composition 4, which is a material according to the present invention containing an added long-chain phosphorylated alcohol (Cl6_18), showed satisfactory defoaming properties. with the composition 3 (which contained Gantrez AN 149 as emulsion stabilizer) is a stabilized oil-1-water emulsion which exhibits acceptable defoaming properties at low concentrations of the high foaming surfactant nonylphenol (EO) -OH. (which also contains Öantrez AN 149) is another stabilized oil-1-water emulsion within the scope of the invention and contains an added synthetic wax pentaerythritis ol-tetrastearate.

This material with the composition 5 shows the best defoaming properties.

Example 2.

Further experiments were performed using 100 ppm of = the material nonylphenol- (E0) x- (PO) -OH without mineral oil in the form of especially thin base oil (ie in water). As the gay foaming surfactant, 50 ppm n ° nirlfen ° 1- (E0) 9,5-oH was used. The foam yields were measured at 451 ° C to 15 ° C over a fifteen minute period at a water temperature of 21 ° C and at a pressure of 41 kPa and the mean value was determined. The defoaming properties, ie. the foam height (in cm), are shown in Table III.

Table III. '_ I Cgf fl is * _' 'msmx-u fl ny-OH. - d 10 ¶ verdi pa ššumnöša _ x Y (om .lo is -. _ "20.35 io zs .iv.1r _- io 35 _. ~ * - ', 17.7ï 15 - _ los. so' I - i4. s1 ^ _ 1z; 5 20 '~'. 20.3) 12.5. ao - - 11.2; 12.5 40 ', ss; 12.5 50... -. s.11, Q Exemgel 4.

Materials of the formula hydrophobic- (E0) x- (P0) y-OH »1 Which hydrophobic is a long chain alcohol, was tested for Isin's effectiveness as a defoamer. ester these tests were carried out at a temperature of 21 ° C, and all defoamers were mixed with 80% by weight of mineral oil of the special type _. , thin base oil. The results of these tests are shown in Table IV.

I 451 382_ 16- Tabe11 Iv, Kolxedjan 1 Mo1er Molèr sxumhögd. alcohols E0 P0 cm) 10 c _ 3 3 '19.05 1 ° 14 _ 3 6' 15.4; , _'3 9 14.9. - '~ 3 12 2 13.4' s .6 19.8 '. 15 s 9 11.3 - 9 _s 12 13.2 '- 7 12 18.3 7 o 20.3 »C12 ~ .._ 1_3 - 3' 6 13 .9 20 1 3 _ 9 12.9 - = - 3 12 12.7 * s 12 13.9 s - 'o 20.3 'c _ f 3'. s 12.9 25 14 18. 3 9 k12.9 3 _ 12- 1 9.6 s o 20.3 s 12 .14.7 1 o 120.3 '

Claims (14)

4s1, ss2, 17 PATENTKRAV _ A method of attenuating foaming in an aqueous liquid with a tendency to foam, for example the aqueous process stream at a paper or pulp mill, characterized in that a defoaming or J-reducing amount of a defoamer is added to the liquid. composition, which contains a defoamer having the structure R 1 - (Eo) x (Po) y-on wherein R 1 is an organic hydrophobic selected from the group consisting of alkylphenols, long chain alcohols and mixtures thereof, EO represents a ethylene oxide moiety, x has a value in the range of 3 to 20, PO represents a propylene oxide moiety and y has a value in the range of 20 to 50, and which additionally, if desired, contains a mono-, di- or tri-phosphate ester of a alcohol, preferably a mono-, di- or tri-phosphate ester of a C 1-6 alcohol, and / or a wax-like material, preferably pentaerythritol tetrastearate. 2. A method according to claim 1, characterized in that said hydro-free alkyl-enol has the structure R 2, R 2, R 2 or wherein R 2 is a linear or branched, saturated or unsaturated, monovalent hydrocarbon radical having from 6 to 18 carbon atoms, preferably from 8 to 12 carbon atoms . 3. A method according to claim 2, characterized in that RQ has the structure caH2a + 1, wherein1 'PaP is an integer tai and has a' value in the range from 6 to 18, preferably from 8 to 12. Ä. A method according to claim 2, known as nia t thereof, that the alkylphenol is nonylphenol or dodecylphenol. 5. A method according to claim 1, characterized in that 451 §s2 18 x has a value from 5 to 15.0. 6. The method of claim 1, wherein R 1 is a monovalent hydrocarbon radical having a molecular weight in the range of 100 to 350. 7. A process according to claim 1, characterized in that R 1 is an organic hydrophobic selected from the group consisting of long chain alcohols having a carbon atom structure C16_18, C10_1u, C1¿_18 or mixtures thereof. 8. A method according to claim 1, characterized in that the defoaming composition additionally contains a carrier, preferably mineral oil of the type especially thin base oil. 9. A method according to claim 1, characterized in that x has a value in the range 9.5 to 12.5 and that the ratio: between X and y is at most o, u2 = 1. W A method according to claim 9, characterized in that said hydrophobic alkylphenol has the structure R 1, R 2 2 or wherein R 2 is a linear or branched, saturated or unsaturated, monovalent hydrocarbon radical having from 6 to 18 carbon atoms, preferably from 8 to 12 carbon atoms . _ 11. A method according to claim 10, characterized in that R 2 has the structure CaH 2a + 1, wherein "a" is an integer and has a value in the range from 6 to 18, preferably from 8 to 12. 12. A method according to claim 10, characterized in that the alkylphenol is nonylphenol or dodecylphenol. 13. The method of claim 9, wherein R1 is a monovalent hydrocarbon radical having a molecular weight in the range of 100 to 350. 14. A method according to claim 9, characterized in that R 1 is an organic hydrophobic selected from the group consisting of long chain alcohols having a carbon atom structure C16_18, C10_1q, C12_18 or mixtures thereof. M m