Патент USA US2407590код для вставки
Patented Sept. 10, 1946 2,407,59 STATES err a 2,407,589 AQUEOUS ALKALINE REACG CLEANING BATH HAVING REDUCED FOG CHAR ACTERISTICS Henry Earl , Tremain and Leslie R. ‘Bacon, Wyandotte, Mich., assignors to Wyandotte Chemical corporationpwyandotte, Mich., a cor por‘ation of Michigan No Drawing. Application February 3,1944, ' ~ Serial No. 520,960 5Claims. (01.252-156) 2 This invention relates to'the suppression of ' foaming in aqueous alkaline solutions, and more particularly to the suppression of foaming in im pure alkaline washing solutions upon agitation by the addition thereto of small amounts of certain organic materials. . suppression under any given circumstances. Larger quantities are of value only as they serve to maintain a reserve against depletion by chemi- - cal reaction, evaporation, mechanicaI carry-out ‘ by adherence to surfaces of moving machine parts , or containers traversing the foam inhibited liquid, Due to the introduction of the hydraulic'type splashing or other causes. Accordingly, it is gen erally very advisable that a working reserve in ex cess of said‘minimum be provided and adequately bottle washer, the problem ‘of foaming of the al kaline solution used is more often encountered. v, This foaming di?iculty is attributable to the tre 10 maintained, the reserve commonly being greater mendous agitation produced. .Whenever foam with increased temperatures to provide against over?ows and is lost down the' sewer, this loss in increased losses by evaporation and chemical re creases the necessary _alkali make-up and thus action‘. the cost of bottle washing, quite aside from a ' The I ' alkaline constitution has considerable variety of other- inconveniences and dangers. 15 bearing on the foaming behavior, and is espe Because this type bottle washer is of considerable cially marked in the case of alkali phosphates. A importance and the materials known to the prior concentration of 1.6 to,2.3% P205, by analysis, in art have not been entirely satisfactory, the ?nd the caustic frequently is suf?cient to cause exces ing ,of an additive functioning‘ e?iciently as a sive foaming. Little decay of the foam occurs‘ in foam suppressor has remained a problem. How 20 several minutes of quiescence after the formation. ever, the tendency to foam ‘of alkali solutions is The presence of large proportions of soda ash or not restricted to any particular mechanical or small amounts of sodium sulfate and -silicates in hydraulic system, but exists wherever foreign caustic alkali is responsible for somewhat similar matter such as proteins, fats, soaps and surface foaming behavior. \ active agents in general are present and there is 25 The object of the invention is to provide a opportunity for air or other gases to be entrapped. new type of anti-foamer additive for an aqueous Furthermore, the quantity of foam formed in solution containing alkaline compounds to allay creases the longer such solutions are in use be cause increased amount of foam promoters are foaming or to ‘hold in check and suppress the tendency to foam, or to change the character of accumulated from the dirty or used objects. The 30 foam being formed into a less stable type. It is tendency to foam is in?uenced by conditions also an object of this invention to provide aque other than the amount of agitation and quantity ous alkaline baths containing anti-foamer, which of foaming promoters present. In general an in foam to a much lesser extent under operating crease in the temperature increases the dl?iculty . - conditions than said bathswithout these addi of suppressing foam; and an- increase in alkali 35 tives. It is, furthermore. an object to clean glass concentration assists in suppression of foam or ware or dishes. metallic and other objects by con froth. Likewise‘an increase of suppressor con¢ tacting them with an aqueous alkali solution con centration increases, without exception, the effec. needed to e?ect-complete suppression. taining foam suppressing additives to offset the tiveness of foam abatement, up to the minimum More or less de?nite minimum quantities of foam suppressing agents are required to effect presence of colloidal ~or other‘ extraneous mate 40 rials tending to produce foams upon agitation. 'More particularly, it is an object to employ the anti-foamers described herein in machines such 2,407,589 as mechanical dish washers, bottle washers or Corporation), wheat flour (commercial brand), metal parts washers to control objectionable .foam'ing behavior arising from the presence of contaminations .derived from the objects con Nacconol N. R. (wetting agent understood to be keryl benzene sodium sulfonate), and an alkali tacted by the alkaline wash water. oleate soap. I Three standard foaming solutions were pre pared by mixing‘ the following materials and re ?uxing at boiling temperature for one hour: . Other objects of the invention in part will b obvious and in part will appear hereinafter. It has been proposed to prevent foaming by ‘adding such, materials as octyl alcohol (0. A. 16,1254), caprylic alcohol (0. ‘A. 12,1058), oleyl 10 and other high alcohols and mineral oils to Pre vent the foaming of various types of solutions. Evaporated milk _____________ "grams" Foamite ____________ _;___.'._....__do__.._ 1.603 5.480 Flour ________ __, _____________ __do____ 4.820 Nacconol N. R. ‘-s ____________ -_do-____ 0.045 There are disadvantages to using these materials in alkali solutions. The simple alcohols are changed chemically by the alkaline medium and are consequently e?ective for only a, relatively Oleate soap ___________________ _..do____ 0.069 Caustic soda __________________ .._do____ 24.0 Water _________________________ __ml__ 800.0 short life only. Not only is there a lesser con centration of the initial alcohols, but the products of the chemical reaction promote foaming. Min. tions and treated as follows: I Portion 1—diluted to 800 ml. Portion 2-—16 grams of ‘caustic soda added and This mixture was divided into three equal por . eral oils ‘are objectionable in the beverage‘ or food 20 industries because of dimcult rinsibility and the " diluted. to 800 m1. ' ' Portion 3--32 grams of caustic soda added and diluted‘to 800 ml. odor and taste left upon bottles or other wares. Furthermore, these compounds are in part vola tile and their eifect is only temporary. The three solutions then comprise respectively, We have found'that an ideal foam inhibitor 25 approximately 1, 3 and 5% (all percentages here should possess the following necessary quali?ca in stated being by weight unless otherwise stated) tions, but these alone are not sumcient: solutions of the caustic alkali, each containing a‘ total of 0.5% of the mixed foaming components. (1) Insolubility or ‘very low solubility in the foaming solution, 1. e. form a recognized I These foaming systems differ only in concentra 30 tion of alkali. separate phase (2) Liquidity at temperature employed (3) Non-reactivity in the'washing medium and - ' Tests non-destructibility to an ineffectual mate The various materials tested for foam suppres sion properties were made up for use as 20% solu rial or a positive foamer tions in acetone. ‘ - . 50 ml. portions of each alkali solution were It should have good spreading and rinsing prop erties under the conditions of use. Furthermore, from the practical standpoint of the food and introduced ‘into 125 ml. Pyrex Erlenmeyer flasks. The properties quantities of foam inhibitors were added, the ?asks stoppered and placed in a forced draft air oven. At the end of 24, 48 and '72 hours beverage industries, it should - be non-odorous, non-toxic and communicate no repulsive taste via 40 the ?asks were removed in conveniently sized the cleansed wares to food products. groups, agitated andfoam observations made at Applicants have found as a result of much ex the end of 10 seconds and 5 minutes after shak- ' perimentation and testing that di-tertiary-amyl phenoxyethanol, p-tertiary-amylphenoxyethanol and diamyl phenol which are thus characterized, possess exceptional foam inhibiting power for aqueous alkaline solutions even when used in very small quantities. They are each particularly ing. The observations were recorded in terms‘ of 6 “Excellent,” “Good,” “Fair,” "Poor" and “Bad.” "Poor" de?nes the foaming tendencies of portion 2 supra in a 3% pure caustic solution. ‘.‘Bad’.’ applies to any system foaming to a greater extent adapted vfor hydraulic type bottle washing, wherein excessive foaming from contaminated alkali wash water is usually encountered. Of these three materials the preferred is di-tertiary- I amylphenoxyethanoL. However, applicants have found that when a 50-50 by weight mixture of trioctyl phosphate , with di-tertiary-amylphe noxyethanol was employed, the inhibiting action was about one-third less effective than with the use of the latter alone as the anti-foamer. These aforesaid compounds are effective when employed in conjunction with either tetradecanol or tri octyl phosphate, which latter compounds are known foam inhibitors. In determining the ‘efficiency and behavior of .1 these inhibitors under various operating condi tions. several materials consideredas represent 65 ative of contaminants to be found in actual com mercial alkaline'wash liquids were selected as foam promoters. Sodium hydroxide, sodium car bonate and tetrasodium pyrophosphate are rep resentative alkaline chemical compounds em ployed in such commercial alkaline washing solu tions. As representative contaminants there were Selected evaporated milk (commercial brand), Foamite (a natural vegetable product manufactured by American-LaFrance Foamite than standard foamer A. “Fair'’ represents the degree where the foaming is no more than half that of the standard. “Good” represents the de gree of foaming, wherein the surface of the so lution is only' partly covered with foam. "Excel lent” signi?es that all foam is inhibited or in stantly destroyed. A large number of known anti-foaming mate rials were examined, but did not qualify under conditions of the above test within 24 hours at 140° F. Only those materials were retained for consideration which rated "good" or "excellent" on this test. Among the materials so dismissed were iso-amyl phthalate, tributyl phosphate, n-amyl alcohol, benzyl alcohol, heptadecanol, resorcinol, benzyl chloride, butyl Cellosolve lau rate,‘ butyl Cellosolve palmitate, dibutyl phthal ate, diphenyl phosphate, tricresyl phosphate, tri phen'yl phosphate, diphenyl and diamylnaphtha lene. - \iTetradecanol, i. e. 7-ethyl-, 2-methyl undecanol-, 4 - ditertiary - amylphenoxyethanol and trioctyl phosphate survived the test. The following examples in Table -I are set out as illustrations of the present invention. How ever, they are not presented with the intention of limiting the scope of the invention, since many variations may be made. 2,407,589 Table L-Comparison of foam inhibitors ‘on 8% solutions of alkali (72% NaOH,28% NaaC‘Os) with 0.5% addition of mixed loamcra at 160‘ 1-‘. Percent loam inhibitor added to solution Hum hem site: ioem inhibitor Foam inhibitor “Mm” 0.00 ‘0.01 0.025 - one Foam deoa period . y Foam deca period y Foam decay period Foam decor period 10sec. 5min. 10sec. 6min. 10sec. 5min. 10sec. 5min. 24 N m___________________ .- g 24 48 None ................... .. 72 Lmmmmmlo11 """" " 'r mm“ P PP P P BI B B P ,B ‘IF 0 mon 2!! . P it72 2* 1 ........... _- 4s ‘ a i’P i‘ . ...... .. i5P i5 i3P i iP - .1: . . iP ' i‘ . iP i a. a .1; a 5 4s IIIIIIIIIIIIIIII F o r’ F o r G “118ml --------------- -— 72 F F . F F F o Trioctylphosph ate ..... ._ 48 ii F a P i F a G a E m'mmmylphen?y' 24 72 l P-Poor. h P ______________ ._ ' B-Bad. l F-Fair. ‘ G-Good. 6 E-Excellent. z; i 1 Under the conditions represented by the fore Various combinations of the foam inhibitors going table it is seen that the carbonated alkali 30 forming applicants’ invention described herein presents a more dimcult foam control problem can be employed with each other. Also these than a caustic soda solution of equal ‘concentra _foam inhibitors are well suited to be employed in tion by weight. Where a light, mineral oil was association with one or more of the previously added to the carbonated alkali, after 24 hours or known foam inhibitors. By such combinations longer, there resulted an unsatisfactory inhibi an inhibitor composition can be offered having tion under all conditions, although some bene?t 35 activity over a wide range of operating. condi over the entirely uninhibited condition. Tetra tions and over a ions period of time. Also if ac decanol shows improved results over mineral oil, quainted in. advance of concentration of alkali especially at the higher concentrations, but the or alkaline salts in the solutions to be treated, or effect is transient. Trioctyl phosphate at this temperature is generally more e?’ective > than 40 of the nature of the‘ foaming constituents, those inhibitors or combination of inhibitors most ei~ tetradecanol after 48 and 72 hours, but slower in fective for speci?c conditions can ‘be recom ' anti-foaming action than di-tertiary-amylphen oxyethanol at the same lower concentrations. This latter material shows a more comprehen mended. ' i For a low alkali range, for example up to 1%, 45 an inhibitor composed of 50% tetradecanol and sive pattern of general eifectiveness under varied 50% di-tertiary-amylphenoxyethanol has proven conditions of use. to be very effective. For high temperatures and a stronger alkali concentration, for example This same-more general pattern of effective ness is further shown by the examples of Table II 3-5%, a mixture of trioctyl phosphate and di-‘ in which an alkali of different composition is 50 tertiary-amylphenoxy-ethanol is excellent. For employed over a considerable temperature range. low temperature operation, a mixture of equal Table H.-Comparison of foam inhibitors on 1% solutions of alkali (95% NaOH+5% tetrasodi um pi/rophosphate) using 0.5% addition of mixed joamers and 0.025% foam inhibitor , 120° F. 140° F. 160° F. Foam decay, period Foam decay period Foam decay period Hours held Foam inhibitor after loam inhibitor addition 10 sec. 24 None ............ .. Light mineral oil.. B1 B 10 sec. B 6 min. Pl 10 sec. ii min. B B 48 B P B - B B B 72 24 P B P B P 1 P P - P B B P P 48 72 24 Tetredecanol .... .- 6 min. B B B B P P Fi B B P P F P B P P B P 48 B / B P P P P 72 B B B B P P Trioctyl phosphate 24 48 G4 IF Di-tertiary-amylphenom-ethanol. 72 24 48 72 G P P F IB-Bad. IP-Poor. iF-Falr. Ei G P P P P P P F P E P P F P F F F P F F F P P F F P F F F ‘Ci-Good. lE--Exo,ellcnt. 2,407,589 . parts of trioctyl phosphate, di-tertiary-amyl phenoxyethanol, and tetradecanol is very satis factory. - 8 and dish washing of about 0.05%, on the basis of weight of the washing solution is suf'iicient, There are various specific applications of the invention other than treating washing solutions, Laboratory tests under dynamic conditions have shown the marked ef?ciency of di-tertiary 5 such as the reduction or elimination of foaming in coating solutions for paper ?nishes, in beater amylphenoxyethanol by itself and‘ in combina operations for paper making, in glue manufac tion with other materials. To conduct these tests ture and sugar boiling; in each of these, ma an apparatus was constructed employing a 10 terials of decided alkaline reaction are employed. gal. steel drum as a container for‘, a foaming so lution, a positive pressure pump for withdrawing 10 These foam inhibitors can also be used in alka line anti-freeze mixture, in alkaline liquors un solution from the liquid phase near the bottom dergoing distillation, in boiler waters, in soap liq and delivering same via a number of Jets into nor; for treating fabrics, in wet method dust col milk bottles inverted overthe solution reservoir. lectors, and as a safety control against boiling Foaming constituents were employed in the same of kettles used in soap manufacture. ratios as hitherto described, but at ?ve fold con 15 over The above described foam inhibitors function centrations, 'i. e. 10 liters of foaming solutions in the various types of aqueous alkaline solutions. . contained 300 g. of caustic soda, 33.4 g. evap They are operative in strongly alkaline mediums orated milk, 113.7 g. “Foamite," 100.4-g. ?our, in which caustic alkalies may be present and in 0.935 g. "Nacconol NR" and 1.465 g. sodium ole ate. 10v ml. of the anti-foamer was employed 20 weakly alkaline solutions. They are of most (0.1% approximately). Foam was allowed tode- . V velop close to the point of over?owing the con tainer prior to addition of the anti-foamer. - Under these circumstances a 60-50 mixture of di-tertiary-amylphenoxyethanol and utility probably in the ?eld of alkaline detergents, especially those containing caustic alkali. - The above description and speci?c examples are to be construed as illustrative only and not limiting the scope of the invention. Any trioctyl 25_ as modi?cations or variations therefrom which con phosphate suppressed or caused complete decay -' form to the invention are intended to be included of the standing foam within about one to four in the scope of the claims. minutes operation of the system at 20 lb. pump We claim: pressure and 140° F. solution temperature. This 1. An aqueous alkaline solution having reduced addition effectively suppressed foam for about 80 foaming'characteristics containing in addition to hours of continuous operation, failing 111/2 water, a soluble alkaline agent, and a constitu rather abruptly within about 15 minutes after ent tending to produce foam, admixed with a the ?rst foam appeared. A check run failed in minimum of .01% by weight of at least one foam 11 hours and 55 minutes. Two runs using selected from the group consisting of straight di-tertiary-amylphenoxyethanol failed 35 inhibitor di - tertiary - amylphenoxyethanol, p-tertiary at 17 and 17% hours respectively. Trioctyl phosphate, therefore, depreciated the perform ance of di-tertiary-amylphenoxyethanol alone. P-tertiary-amylphenoxyethanol under similar conditions failed at 2% hours, but lo‘ml. addi tion of the same inhibitor extended foam sup pression for several fold this period. Tests conducted under practical milk bottle amylphenoxyethanol and diamyl phenol. _2. An aqueous alkaline~reacting cleaning bath having reduced foaming characteristics contain 40 ing in addition to water, caustic alkali and at ‘ least one constituent tending to produce foam, » admixed with a minimum of .01% by weight of at ' least- one foam inhibitor selected from the group consisting of di-tertiary-amylphenoxyethanol, ‘ washing conditions have shown that as little as 45 p-tertiary-amylphenoxyethanol and diamyl phe nol. phenoxyethanol and trioctyl phosphate added at 3. An aqueous alkaline-reacting solution hav intervals of 1 to 11/4 hours to 625 gal. of a 315% ing reduced foaming characteristics containing caustic test solution of a 72% NaOH-28% in addition to water, a soluble alkaline com NaaCOs bottle washing alkali in 13 gr. hardness water and operating at ll5-l35° F. and 15-18 lb. 50 pound and a constituent tending to produce foam, 20 cc. of the 50-50 mixture of di-tertiary-amyl admixed with a foam inhibitor composition com pump pressure were sufilcient to deal with an prising a mixture of di-tertiary-amylphenoxy ethanol and trioctyl phosphate, each of said last extremely dimcult foaming problem. In another plant also using a “soaker-hydro" type machine and a very difficult alkali from the . named ingredients being present in the amount to 1/2 of the entire mixture. foam suppression viewpoint (adding one part of 55 of 4.$4; An aqueous alkaline-reacting solution hav an alkali polyphosphate to 6-7 parts of a 95% ing reduced foaming characteristics containing caustic-5% tetrasodium pyrophosphate solution 1‘ in addition to water, a soluble alkaline compound held at 3% caustic test and 140° F.), excellent and a constituent tending to produce foam, ad foam suppression resulted from the addition of 60 mixed with a foam inhibitor composition com 1 pint of the same 50-50 mixture to about 350 prising a mixture of equal parts of (ii-tertiary gal. of washing solution. Foam suppression was amylphenoxyethanol and trioctyl phosphate. immediate and complete and no adverse results were noted on washing or rinsing performance. This addition was effective for more than 30 hours of operation. The amount of foam inhibitor to be used in 5. An aqueous alkaline-reacting solution hav ing reduced foaming characteristics containing 65 in addition to water, a soluble alkaline com any particular assignment cannot be de?nitely stated because of the variation of such factors as surface tension of the solution, the area ex posed, the temperature, or the violence of agi 70 tation. In general, an amount of anti-foamer for aqueous alkaline cleansing solutions for bottle pound and a constituent tending to produce foam, admixed with a foam inhibitor composition the major ingredient of which is di-tertiary amylphenoxyethanol. HENRY EARL TREMAIN. LESLIE R. BACON.