NO820545L - PROCEDURE FOR FOAM INHIBITION OR COMPRESSION - Google Patents

Description

The present invention relates to methods for regulating, suppressing or inhibiting foam formation in aqueous industrial media. More particularly, the present invention provides a method of inhibiting foam which is particularly well suited for paper mill and pulp mill applications.

.Strong foaming is an.Unwanted, occasional feature

at many aqueous industrial transport and process systems

more. Strong foaming acts to reduce the efficiency of the process machinery and thereby to increase the price of the final product. An aqueous industrial medium or environment where the problem of strong foaming. have long made themselves known, are the conditions in paper production or pulp production. Foaming (for example due to the presence of wood resins) occurs in several places in pulp and paper mills, and

many precautions have been proposed to inhibit such foaming. In general, the proposed precautions are chosen for a. especially, place in the factory. Such locations include the brown pulp washer, where hot pulp is washed to remove entrapped liquid, the screening section where the washed pulp from the brown pulp washer is subjected to displacement washing and cooling before being conveyed to the bleaching plant, and the papermaking machine where the bleached pulp is formed into paper. On

in the first of the two places, the foaming generally takes place in an alkaline aqueous medium, while in the latter it generally takes place in a surficial aqueous medium.

The present invention discloses a progress

method for foam-inhibition in aqueous industrial media that have a tendency to foam, such as the above-described media" typically found in a paper or pulp mill. The method comprises subjecting a foaming or potentially foaming aqueous system to the action of a effect

tive amount of a defoamer or antifoam

means as described, herein, by which the foaming properties of the liquid are reduced, suppressed or destroyed.

According to one aspect, it comprises present invention, in short, a method for inhibiting foam or foam

ning in an aqueous industrial fluid which tends to.

do this, which procedure includes the step that

a foam-reducing, foam-inhibiting or foam-reducing agent is added to the liquid in an amount that works to reduce or eliminate foam, where the foam-reducing agent. comprises.polyether chain consisting mainly of polyethylene oxide (EO) "block" residue or condensate which bound at one end thereof has poly-1,2-propylene oxide (PO) ".block" residue which is hydroxyl-terminated, as the on the remaining one. end of the poly-(EO) residue is organic hydrophobic part or hydrophobic. In order to achieve the advantageous foam suppression that is possible by carrying out the present invention, the hydrophobic must generally comprise approx. 3% by weight to approx. 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 is preferably in the range of approx. 3:1. In general, the defoamer is suitably dissolved or dispersed in a carrier which can be inorganic such as water or organic such as mineral oil.

In a preferred embodiment of this invention is

the aqueous liquid process stream in a paper mill or . mass production. the foaming being due to the presence of wood resins, lignin sulfonates, surfactant processing or starting material additives, and mechanically induced air entrapment.

In another preferred embodiment of the invention, the above-mentioned liquid foam dampening material further comprises an auxiliary amount of phosphorylated synthetic or fat. alcohol mono-, di- or triesters.

In a further, preferred embodiment of this invention, the above-described antifoam material further comprises a wax-like material such as pentaerythritol tetrastearate. Such a wax-like material has previously been used in foam dampening materials and has been found to . be particularly well suited here.

As the term is used herein, "inhibit" shall include any corrective or preventive measures that can be taken to eliminate the problems caused by heavy foaming. "Inhibit" is specifically intended to include the destruction, reduction or inhibition of foam as well as the reduction or elimination of entrapped air. By reducing or eliminating trapped air (which can occupy up to approx. 15% by volume of the process flow which is subjected to strong mechanical agitation), the efficiency of the process will thus be increased even if the process flow, for the naked eye may appear to show practical spoken. no change in the amount of surface foam before<*>and after the addition of the present antifoam. "Hydrophobic or hydrophobic part" as the term is used herein shall include monovalent, mainly hydrocarbon-based parts which are essentially water-soluble and which generally have molecular weights in the range •100-350. As more fully discussed below, the preferred hydrophobics include alkylphenol moieties and higher molecular weight saturated or unsaturated alcohol moieties, or mixtures thereof.

When applying the present method to the reduction or destruction of foam in aqueous media, the materials described herein are mixed with the potentially or actually foaming aqueous material (in an appropriate proportion), practically by any desired or appropriate method. . The materials can be poured, sprayed, or added to the body of the foam or placed on top of the liquid, thereby reducing or removing the foam. Addition of the present materials to the liquid that lies below the already formed foam is another method of working which is contemplated by the present method.

Short, description of the drawing

The drawing is a triangular diagram showing foam height measurement as a function of the foam damping material.

Detailed description of the invention

The foam inhibiting materials suitable in the present invention comprise nonionic polyethers having a polyethylene oxide condensate residue or segment (~OC2H4~)xbonded to a hydroxy-terminated (-OH) poly-1,2- propylene oxide condensate segment or residue (-OC^Hg-) ^.OH, the remaining end of the polyethylene oxide segment being bound to a relatively hydrophobic organic part, such as eri alkylphenol, higher molecular weight alcohols or mixtures thereof. The anti-foam materials according to the present invention can be re-presented by the structure:

where is a monovalent organic hydrophobic moiety or hydrophobic, preferably selected from the group consisting of long chain or high molecular weight primary or secondary alcohols, alkylphenols, or mixtures thereof; x is the value of the average number of moles or units of ethylene oxide per foam dampening agent molecule and has a value in the range of 3-20, preferably 5-15; y is the average number of moles or units of propylene oxide per molecule defoamer and has a value in the range 15-60, preferably 20-50.

To achieve the beneficial anti-foam properties

with the materials described herein, it has been found that both the relative quantities and the relative locations of the EO and PO segments must be as described herein. Materials which have the same relative amounts of ethylene oxide and propylene oxide residues (i.e. the same weight percentages), in which the ethylene oxide and propylene oxide appear as random segments, are not suitable. defoamers and are not included within the scope of the present invention. The present invention takes. thus aiming at the use of an antifoam agent comprising an organic hydrophobic as described above, bound to. a segment or "block" of repeating ethylene oxide units (such as would result upon ring-opening condensation of "x" moles of ethylene oxide into a chain), which in turn is. bound to a second segment or block of repeating propylene oxide units (such as would result upon condensation of y mol 1,2-propylene oxide), the propylene oxide block being hydroxy-terminated.

When carrying out the present invention, as mentioned above, very specific amounts of organic hydrophobic, EO and PO segments are required in the foam suppressant in order for the advantageous foam inhibition of the present invention to be achieved. In particular, when a preferred alkylphenol hydrofpb (such as nonylphenol) is used, it has been found that particularly remarkable foam inhibition is achieved (in a paper mill environment) if the polyether chain has an average of 12.5 repeating EO units, i.e. an average of 12.5 moles, and from 25 to 60 PO units should be added to the chain to make the antifoam.

From the drawing figure, it will be seen that the hydrophobic/EO/PO weight ratio is decisive for the inhibition of foam due to the presence of other surface-active agents. The figure shows in triangular coordinates the rather narrow areas for anti-foam composition, which provide the foam-inhibiting properties that can be achieved by performing this invention in the preferred paper mill or pulp mill embodiment. The figure's axes respectively show the percentage by weight of hydrophobic, the percentage by weight of polyethylene oxide residue and the percentage by weight of 1,2-polypropylene oxide residue. The numbers within the contour zones of the figure are foam height (in inches) determined according to the test described below.

Characterization of the foam-inhibiting performance of the foam suppressants herein is an internal test developed by the patent applicant. The present test has been found to predict the foam inhibiting ability of a given defoamer under actual industrial process conditions (eg in a paper mill).

Foam height measurements were. carried out by adding approx. 100 parts per million (ppm) of the antifoam to be tested, to 3 liters of water of 21°C contained in a temperature-adjustable 3 liter metal beaker. The defoamer was dissolved or dispersed in the preferred organic mineral oil carrier and comprises, approx. 80% by weight mineral sealing oil. and 20% by weight antifoam. The entire antifoam material was thus added to a 500 ppm concentration. The water in the beaker contained approx. 50 ppm nonylphenol-EO, which had an average of 9.5 mol EO per nonylphenol core. This alkylphenol polyether based surfactant is a high foaming surfactant commonly used in paper/pulp operations, particularly if. simultaneous or subsequent de-inking or cleaning of cellulose fiber is desired. A transparent glass cylinder protrudes upwards from the edge of the metal cup, . so that it contains foam that forms therein. The glass cylinder has an external vertical measuring rod for measuring the height of a column of foam formed therein. Near. the .

open end of the glass cylinder and directed into the metal cup it is. arranged a spray nozzle no.' 30/15 "V-Jet", which is in communication with a pressure-adjustable water pump. The water pump circulates the contents of the beaker through the nozzle, whereby the concentration of materials therein does not change. For evaluation purposes herein, a pressure of 42 kPa was provided by the pump to the nozzle. A short period of time after starting the pump, an equilibrium foam height is achieved in the glass cylinder, which equilibrium foam height is characteristic of the foam suppressant being tested.

After starting the pump, the foam height was read once per minute for 15 minutes. The average of these 15 shed heights was then determined. "Acceptable" foam suppression or foam inhibition or suppression for purposes of the invention is an average foam height over a 15 minute time period of approx. 5 logs or less. Zones of acceptable foam damping performance are indicated on the figure and begin with the 4"-5" range. For comparison purposes under •the above condition-

ser, an aqueous solution containing 50 ppm of nonylphenol (EO) g [- without any of the present antifoam materials produced a foam height of over 9 inches in about 2 minutes and caused pump cavitation and loss of pressure.

For a further verification of the good anti-foam effect of materials within the framework of the present patent claims, a separate test was carried out with the anti-foam agents in water (i.e. no hydrocarbon carriers were used).

It was found that the defoamers worked satisfactorily in an aqueous carrier, defoaming zones similar to those in the figure resulting. As the organic mineral oil carrier is not necessary for the effectiveness of. the present invention, 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 defoamers in the organic medium proved to be less sensitive to small changes

in the P0/E0 ratio. Organic materials such as naphthenic oils,

mineral oils, paraffin oils or kerosene are therefore the preferred carriers. The most preferred carrier for the anti-foaming agent is mineral oil, there being preferably 80% by weight of mineral oil and 20% by weight of anti-foaming agent in the anti-foaming agent material.

Alkylphenol-polyether defoamers constitute a particularly preferred class of defoamers. These alkylphenol-polyethylene oxide hydroxyl-terminated polypropylene oxides are generally prepared from alkylphenol-polyethylene oxide starting materials. Alkylphenol polyethylene oxide starting materials are a well-known class of surfactants

which has long been used in many different industrial processes. Such conventional materials have a structure

where is a branched or unbranched, saturated or unsaturated monovalent. hydrocarbon radical. with 6-18 carbon atoms, preferably with 8-12 carbon atoms, and can in a preferred sense be empirically represented by the homologous formula C H- ., (preferably only one R- is bound to the phenolic iron but several R2~ radicals can be used within .frame of invention); x has a value of 3-20 (preferably 5-15), each (-OC^H^-) unit being derived from the ring opening of ethylene oxide

also "known as oxirane. (Alkyl chains are sometimes repre-

tert herein at "C", where "a" is the number of carbon atoms i

a chain, for example C, ~ or Cj_2-14 when a mixture of chains is intended. This representation shall be understood to represent any saturated or unsaturated, branched or unbranched hydrocarbon moiety having "a" carbon atoms. When a saturated type is intended, "C cl" can be expanded to the empirical formula for the portion of C H„ .,, i.e. CnH, n. A particularly preferred one

a 2a+l ... 9 19 ^

class of starting materials for the synthesis of alkylphenol polyethers in which are nonylphenol polyethylene oxides. (N.P-EO)'.

Nonylphenol polyethylene oxides which can be used in the present invention are characterized by the presence of an alkyl chain with 9 carbon atoms, which is bound to the aromatic nucleus (in the ortho-, meta- or para-position with respect to the polyether chain), hydroxy-terminated polyether chain with 3-20 ethylene oxide units (i.e. that x has a value of 3-20). When defoaming in a paper mill or pulp mill environment is intended, x preferably has a value of 5-15, more preferably 8-14. While such conventional NP-EO materials can be synthesized in fairly pure fractions with a fairly specific value of x, they are commonly sold as mixtures of molecules having a range of x values. These mixtures are characterized by their average x- value, and a common material is therefore NP-EOg ^ which contains an average of 9.5 ethylene oxide units (mol) per nonylphenol core (x = 9.5). Nonylphenol polyethylene oxides, which have average x-values from 3 to 20. are commercially available from various companies, including GAF Corp. under the trademark "Igepal", Rohm and Haas Company under the trademark "Triton" and Jefferson Chemical Company under the trademark "Surfonic".

With the present invention, hydrophobic polyethylene oxide parts are used as bonded to the distal end of

■ the polyethylene oxide chain has a plurality of 1,2-polypropylene oxide units (-OC^Hg-) and the polypropylene oxide chain is preferably hydroxy-terminated, and the structure of the antifoam material is according to formula I. It has been found necessary that The polyethylene oxide segment is in a neighboring position with the hydrophobic part to achieve the advantageous foam-. damping characteristics that are possible in the practice of this invention.

The hydroxy-terminated nonylphenol-polyethylene oxide-polypropylene oxides (NP-EG^-PO^-OH) according to the invention are produced according to methods that are well known to professionals in the field. For example, NP-EO-PO-OH can be produced by reaction

.f x y of NP-EO (for example "Igepal" or "Triton") with propylene oxide at, for example, 100°C-150°C under 1-4 atmospheres of air t-^. pressure in the presence of an alkaline catalyst, for example KOH. U.S. patent 3,021,372 (Dupre et al.) particularly describes a ..production of the preferred hydroxy-terminated octylphenol and nonylf enol polyethylene oxide polypropylene oxides, and the teachings of said patent are incorporated herein by reference. In general, it is preferred that the catalyst used for the production of the NP-EO -OH material is not removed before adding the PO segments (i.e. unneutralized NP-EO should be used).

Another preferred class of nonionic surfactants which have been found suitable in the practice of the present invention are hydroxy-terminated ethylene oxide-propylene oxide adducts of a hydrophobic comprising higher molecular weight or long chain alcohols, the polyethylene oxide segment connecting the higher alcohol with polypropylene oxide- . the segment. "Higher-molecular" or "long-chain" alcohols herein means branched or unbranched, saturated or unsaturated, primary or secondary alcohols having from 6 to about 24 carbon atoms and generally has a molecular weight in the range of approx. 75 to 300, as these materials are sometimes designated

as "fatty alcohols". Non-ionic surfactants prepared from the higher-molecular alcohols can be represented as follows:

<R>3<->(<OC>2<H>4)x<->(<OC>3<H>6)y<->OK

where R^ is a branched or unbranched, saturated or unsaturated alkyl chain of a monohydric alcohol, where the alkyl chain has from approx. 6 to about 24 carbon atoms (preferably 10-18), and where the values of x and y are the same as discussed above. Preferred hydrophobic long-chain fatty alcohol moieties for use herein include C 12 -alcohol mixtures, C 12 -18 alcohol mixtures and C 12 -1 g alcohol mixtures.

As discussed above, hydroxy-depleted higher molecular alcohol EO-PO adducts can be prepared by adding the EO-PO polyether segments to alcohols having the desired carbon chain. • Alcohols that can be used in the present can be synthetic alcohols (i.e. alcohols produced by the well-known Ziegler or carbonylation processes) or alcohols that are generally produced by reducing naturally occurring fatty acids to fatty alcohols. Suitable fatty acid starting materials can be produced. from natural sources such as coconut oil, palm oil, tallow, lard and tall oil. The length of the carbon chain and the structure of the alcohol are determined by

the synthetic conditions or the nature of the fatty acid starting material used. Of course, special desired alcohol structures can be obtained from natural sources by distillation or the like, or by the above-mentioned synthetic methods followed by distillation. Particularly preferred higher-alcohol EO-PO adducts for use in the present invention are synthesized by adding - (EO) 12 ,-- (PO) j-Q-OH-polyetherk jeden to a. mixture of alcohols with. 16 carbon atoms and 18 carbon atoms. Hydrophobic in this embodiment could thus be written<C>16-18.

In another preferred embodiment of the invention, the above-mentioned liquid defoamer is mixed with mineral oil and . further comprises an auxiliary amount of phosphorylated mono-, di- or triester ester of fatty alcohol or synthetic alcohol,

with the structure:

where , Rj and Rg can be equal or different and represent alcohol residues of monovalent, fatty acid-derived or synthetic, primary or secondary, saturated or unsaturated alcohols with a branched or unbranched chain.

The phosphorylated organic alcohol is produced according to well-known methods for the production of phosphoric acid esters, the preferred organic alcohol having 16-18 carbon atoms. Other alcohol residues which can be used include C^g_22 ^20+<e>^-^er mixtures thereof. In a preferred sense, the phosphorylated organic alcohol will thus be mixed with the above-described defoamer and carrier (for example mineral oil), and the mixture of defoamer, carrier and phosphoric acid ester can be used in the same way as the defoamer alone.

In a third preferred embodiment of the present invention

■ invention, the above-mentioned antifoam material is mixed with a petroleum or synthetic wax-like material. A particularly preferred wax-like material is a synthetic, non-petroleum derived pentaerythritol tetrastearate. It should be emphasized that this wax-like material is to be used in addition to the above-mentioned anti-foam material (with or without the phosphorylated alcohol) when inhibiting foam. A particularly preferred material is available from Cyclo Chemical Company/under the trade name "Cyqlochem PETS".

Various modifications and changes in the invention will appear to professionals in the field without deviating from the framework and idea of the invention, and it should be understood that this invention is not limited to the illustrative embodiments and examples given herein.

Example 1

This illustrates the production of the hydroxy-terminated

nonylphenol-(EO) x-(PO)'- -0H....

A flushable 7,500 liter pressure reactor made of stainless steel equipped with a stirrer and a temperature control mechanism is charged with 732 kg of nonylphenol. The nonylphenol is stirred (10 min.) while nitrogen is bubbled through it. 20 kg of potassium hydroxide are added to the nonylphenol, the reactor being repeatedly flushed (for example 3 times) with nitrogen and left with a slight N02 overpressure. At this point becomes

the reactor's contents heated to 110°C, at which temperature the reactor-again is flushed with dry nitrogen which leaves a

nitrogen overpressure. The heating of the reactants is continued to 120°C, at which point the heating is stopped and the container repeatedly flushed as described above. Approx. 1,390 kg of ethylene oxide is supplied to the reactor at a rate of 19 liters to the 45 liters per minute, as the speed of

the ethylene oxide addition and the heating or cooling of the reactor are monitored so that the stirred reactant medium is kept at a temperature in the range 143°C -5.5°C. The reactor pressure should be kept at less than 400 kPa during EO addition. Ethylene oxide is added to the point where the nonylphenol ethylene oxide has a 1% aqueous cloud point (i.e. that the temperature at which

the material, in a 1% aqueous solution of the material, begins to come out of solution (as indicated by cloudiness) in the temperature range of 53°C. to 5 8°C..After completion of E0-. addition, the mixture is allowed to react at 143°C - for 15-30 minutes. PO is then added until the 1% cloud point in a 20% diethylene glycol monobutyl ether solution of the EO-PO adduct is 48-50°C. Continued addition of PO further reduces<1>the cloud point of the adduct. After the .PO addition, the finished product is cooled to .79°C, and 20.4 kg of glacial acetic acid is added to the product to neutralize the KOH, the product being stirred for a further 30 minutes. This completes the synthesis of the nonylphenol-EOg^-PO^^-OH antifoam material.

Nonylphenol was used for the synthesis of a number of surfactants according to the present invention with different amounts of EO and PO using a method analogous to the one described above. The antifoam performance of these surfactants was then measured according to the test described above. The results of this evaluation are shown in Table<:>I.

Example 2

For the purpose of comparing the foam damping properties, a series of materials with the following properties (in percentage by weight) were made. manufactured and tested.

All foam suppression tests were carried out with 160 ppm of the respective compositions, with. from 100 to 600 ppm nonylphenol-(EO)g5~°H high-foaming surfactant. The results of this comparison are shown in Table II, where the numbers are. foam heights measured 1 minute, after each further addition of high-foaming surfactant.

These foam height measurements in Table II were carried out by

21°C and a pump pressure of 41 kPa. It should be noted that composition 4, which falls within the scope of the present invention and which contains an added phosphorylated long-chain Cj. g_^g-alcohol showed satisfactory antifoam performance.

- Composition. 3 (where "Gantrez AN 149" is used as an emulsion stabilizer) is a stabilized oil-in-water emulsion which shows acceptable foam suppression at low concentrations of high-foaming nonylphenol (EO)_C-OH. Composition 5 (where "Gantrez AN 149" is also used) is another stabilized oil-in-water emulsion within the scope of this invention containing an added synthetic pentaerythritol tetrastearate wax which shows the best antifoam effect. Example 3 Further experiments were carried out using 100 ppm of the nonylphenol-(EO)(PO)-OH material without mineral sealing-x y oil (i.e. in water). Fifty ppm nonylphenol-(EO)g g-OH was the high-foaming surfactant used, as fifteen-minute averages in water of 21°C at 41 kPa were measured. The foam cushioning properties (i.e., foam height measurements in inches) are shown in Table III.

Example 4

Long-chain alcohol hydrophobic (EO) x -(PO) y-OH materials were ■•■ tested for efficacy in foam inhibition. These experiments were carried out .'by . 21°C, all the antifoams being mixed with 80% by weight of mineral sealing oil. The results of these experiments are shown in Table IV.

Claims (47)

.1.. Method of inhibiting foam in .an aqueous liquid which tends to do so, which method comprises, the step of adding to the liquid an antifoam agent in a amount effective to reduce or eliminate foam, where the foam suppressant comprises polyether chain consisting mainly of polyethylene oxide block or chain comprising an average of 3-20 mol of ethylene oxide, and where a poly-1,2-propylene oxide block or chain comprising 15-60 mol of 1,2-propylene oxide is bound to one end of the polyethylene oxide chain, the propylene oxide chain being hydroxyl -terminated, while the remaining end of the polyethylene oxide chain is; bound to an organic hydrophobic. 2. Method according to claim 1, wherein the hydrophobic. is selected from the group consisting of alkylphenols, long-chain alcohols or mixtures thereof. 3... Process according to claim 2, wherein the alkylphenol is of the structure where R2 is branched or unbranched, saturated or unsaturated monovalent hydrocarbon radical having from 6 to 18 carbon atoms. . 4. Method according to claim 3, where R2 has from 8 to 12 carbon atoms. 5. Method according to claim 3, wherein R2 is of the structure C H0 _ i_ if where "a" has a value in the range approx. 6 to 6 p.m. a <said • ± 6. Method according to claim 5, where "a" is in the range 8-12. 7. Process according to claim 3, where the alkylphenol is nonyl-phenol. 8.. Method according to claim 3, where the alkylphenol is dodecylphenol... 9. Method according to claim 1, where the polyether chain comprises 5-15 units or moles of polyethylene oxide and 20-50 units of poly-1,2-propylene oxide. 10. Method according to claim 1, where the liquid is the aqueous process flow in a paper mill or pulp mill. 11. Method according to claim 1, where the antifoam further comprises mono-, di- or tri-alcohol phosphate ester. 12. Method according to claim 11, wherein the foam suppressant further comprises C-^^g-alcohol mono-, di- or tri-phosphate ester. 13. Method according to claim 1, where the foam suppressant further comprises a wax-like material. 14. Method according to claim 13, where the wax-like material is pentaerythritol tetrastearate. . 15. Method of inhibiting foam in an aqueous paper mill or pulp mill process stream, wherein the process comprises the step of adding to the stream a defoamer in an amount that reduces or eliminates foam, and wherein the defoamer comprises polyether chain consisting essentially of a Polyethylene oxide block or chain comprising an average of 3-20 mol ethylene oxide, with a poly-1,2-propylene oxide block or chain comprising 15-60 mol 1,2 -propylene oxide, where the propylene oxide chain is hydroxyl-terminated, while the remaining end of the polyethylene oxide chain is bound to an organic hydrophobic. 16. Method according to claim 15, where the hydrophobic is selected from the group consisting of alkylphenols, long-chain alcohols or mixtures thereof. 17. Method according to claim 15, where the alkylphenol is of the structure where R- is a branched or unbranched, saturated or unsaturated monovalent hydrocarbon radical which has approx. 6 to 18 carbon atoms.. 18. Method according to claim 15, where R_ has approx. 8 to 12 carbon atoms. 19. Method according to claim 15, where R 2 is the structure 'CJ. , where "a" is a whole number and has a value in the range from approx. 6 to 18. 20. Method according to claim 19, where "a" is in the range, from approx. 8 to 12... 21. Method according to claim 15, where the hydrophobic is nonylphenol. 22. Method according to claim 15, where the hydrophobic is dodecyl-. phenol; 23. Method according to claim 15, wherein the polyether chain comprises 5-15 units of polyethylene oxide and 20-50 units of poly-1,2-propylene oxide. 24. Method according to claim 15, where the antifoam further comprises mono-, di- or tri-alcohol phosphate ester.. 25. Method according to claim 24, wherein the antifoam comprises .C1g_1g alcohol mono-, di- or tri-phosphate ester. 26. Method according to claim 15, wherein the antifoam further comprises a wax-like material. 27. Method according to claim 26, where the wax-like material is pentaerythritol tetrastearate. 28. Method of inhibiting foam in an aqueous paper mill or pulp mill process stream, the process comprising the step of adding to. the stream a foam-suppressing or -redu- . amount of a defoamer material comprising defoamer. of the structure where R 1 is hydrophobic, x has a value in the range from 3 to 20 and y has a value in the range 15-60. 29. Method according to claim 28, where is a monovalent hydrocarbon residue having a molecular weight in the range 100-350. 30. Method according to claim 28, where R 1 is an alkylphenol with the structure where R2 is a branched or unbranched, saturated or unsaturated .. monovalent hydrocarbon radical with 6-18 carbon atoms. 31. Method according to claim 30, where R2 has from 8 to 12 carbon atoms. 32. Method according to claim 30, where R2 is of the structure Ca H2a+l' ^ vo^ "a" ^is a value in the range approx. 6 - 6 p.m. 33. Method according to claim 30, where the alkylphenol is nonylphenol 34. Method according to claim 30, wherein the alkylphenol is dodecylphenol. 35. Method according to claim 28. where R^ is selected from the group consisting of long-chain alcohols having carbon atom chains of the structure C1 .g_1 g,C1 q_14 , C] _2-] _8' and mixtures thereof. 36. Method according to claim 28, wherein the foam damping material further comprises a carrier. 37. Method according to claim 36, wherein the hydrocarbon carrier is mineral sealing oil. 38. Method according to claim 28, wherein the foam suppression material further comprises phosphorylated, long-chain alcohol. 39. Method according to claim 38, where the phosphorylated alcohol is a mono-, di- or tri-phosphate ester of a mixture of C±q-iq~ .alcohols. 40. Method according to claim 28, where the foam dampening material further comprises a wax-like material.. 41. Method according to claim 40, wherein the wax-like material comprises pentaerythritol tetrastearate. 42. method according to claim 28, where x has a value in the range ca. 5-15> and y has a value in the range 20-50. 43. Method of inhibiting foam in an aqueous pulp mill or paper mill process stream, the process comprising the step of adding to the stream a foam suppressing or reducing amount of a foam suppressing material comprising: a> defoamer of the structure R-^-EC^POy-OH, where R-^ is a hydrophobic, x has a value in the range 3-20, and y has a value in the range 15-60; b) an organic or inorganic carrier; ■c) a fds.forylated long-chain alcohol, and, optionally d) a wax-like material. 44. Method according to claim 43, - where R^ is selected from the group consisting of alkylphenols, long-chain alcohols or mixtures thereof. 45. Method according to claim 43, where x has a value in the range approx. 5-15, and y has a value in the range approx.- 20-50. ... 46. Method according to claim .42, where the carrier is mineral sealing oil...<.> 47. Method according to claim 4.2, where the wax-like material is pentaerythritol tetrastearate.