US 3650965 A
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nited States Patent Office.
3,650,965 Patented Mar. 21, 1972 ABSTRACT OF THE DISCLOSURE Low foam detergent composition consisting essentially (a) anonionic surface active component having a cloud point above 45 C.,
(b) an amount of the order of 5 to 100% by weight of component a, of a nionionic surface active component having a cloud point below 35 C.,
(c) an amount of the order of 1 to 50% by weight of component a, of a component selected from the group consisting of aliphatic monocarboxylic acids and aliphatic alcohols wherein the aliphatic radical contains 8 to 18 carbon atoms, and
(d) when said composition contains aliphatic monocarboxylic acid as component c, an amount of the order of 1 to 20 times the weight of component a of a mineral acid, preferably phosphoric acid.
When a combined detergent-sanitizer action is desired said composition should also contain an iodine source providing an amount of available iodine of the order of 5 to 50% of the combined weight of components a and b.
BACKGROUND OF THE INVENTION In the cleaning and sanitizing of equipment in the dairy industry and other food handling fields by cleaned-inplace (C-I-P) procedures, there has been a long felt need for more effective low foam detergent compositions. In attempting to meet this need many formulations have been proposed and marketed based on the use of detergents selected for low foaming characteristics, or combinations of such detergents with foam depressants. While some of these formulations have performed reasonably well within a narrow temperature range it frequently happens that the desired low foam characteristics are lost, with the production of excessive foam, if the temperature varies appreciably from such narrow range.
It has been possible in the past, for example, to prepare low foam detergents which may perform satisfactorily with cold water or room temperature water, but it is recognized that in the cleaning and sanitizing operations there is great advantage in using hot water. In cleaning pipelines and the like characterized by a very large ratio of surface to volume, hot water rapidly becomes cool Water unless special provision is made for reheating the circulating medium during the cleaning operation. Such a procedure has obvious economic drawbacks and represents a rare procedure in actual commercial practice.
The vast majority of those engaged in C-I-P cleaning operations in the dairy and food handling industries would prefer to employ cleaning solutions which may be heated at the start, but require no heating thereafter in the cleaning cycle; but heretofore no detergent composition has been available which performs with optimum effectiveness under such conditions. Operators have had to either eliminate the use of detergent, or contend with the annoying problem of excessive foaming in portions of pipelines and other equipment. The problem is magnified with special purpose detergent-sanitizer compositions containing iodine, as iodine tends to increase the amount of foaming; and this added to the increased foaming experienced due to temperature change of a circulating medium, has greatly restricted the use of such special purpose cleaners in C-I-P systems.
THE INVENTION The new low foam detergent compositions of the present invention meet the long felt need above mentioned by providing a temperature coeflicient approaching unity throughout the 25 to 60 C. temperature range which characterizes most cleaning systems in which the cleaning solution is initially heated, but not thereafter reheated. In other words, compositions have now been discovered which at the intended use dilutions for cleaning and/or sanitizing purposes, produce very low foaming and show little significant change in the amount of foam or nature of the foam, i.e. its speed of breaking, throughout the 25 to 60 C. temperature range.
The new low foam detergent compositions of the present invention comprise a uniquely balanced combination of high cloud point nonionic surface active component, low cloud point nonionic surface active component, defoamer selected from the class consisting of fatty acids and fatty alcohols, and a mineral acid in instances in which the defoamer is a fatty acid.
These active components can constitute the complete composition or water and/or solvent can be present; and when combined detergent-sanitizer action is desired, a source of available iodine can be included. For reasons of economy in packaging and handling, the detergent composition is preferably prepared in concentrated form, intended for high dilution in making use solutions; and it is in the solutions that the low forming properties with little change in the amount or nature of foam throughout the 25 to 60 C. temperature range is of practical importance. Thus the relative amounts or proportions of active components can best characterize the new composition in both concentrated or commercial product form and in the use dilutions thereof. Furthermore, as the high cloud point surface active agent is usually the predominate detergent component the amounts of other active compo nents will be related to the parts by weight of said high cloud point material.
The high cloud point nonionic surface active component can be one or more nonionic surface active agents having a cloud point of at least 45 C., and preferably at least 55 C., in 1% aqueous solution. Suitable nonionics of this type are those containing both ethylene oxide (E0) and propylene oxide (PO) groups, having a molecular weight of at least 1800, and suitably in 1800 to 6000 range, with the molecular weight of PO being at least 800, and the E0 being not more than 65% by weight of said component.
In switching from lower to higher molecular weight materials, the maximum amount of E0 must be reduced. Thus, as the molecular weight of the PO portion increases from about 800 to 4000 the maximum amount of E0 should decrease from about 65 to 30%. Alkyl phenolethylene oxide condensates and fatty alcohol ethylene oxide condensates are not suitable high cloud point materials.
The limitations set out above exclude the better known high cloud point nonionic detergents which, although frequently classified as low foamers, are known to foam excessively in pipelines and the like, and are entirely unsuited for use in the new compositions. Preferred nonionic detergents which satisfy the conditions above noted are Pluronic L35, a condensate of ethylene and propylene oxides, having an average molecular weight of 1900, containing a propylene oxide prepolymer of about 950 molecular weight, and an amount of ethylene oxide equal to about 50% of the total weight of the detergent; Pluronic L44 which is a similar condensate having an average molecular weight of 2200, in which the propylene oxide nucleus has a molecular weight of about 1300 and the ethylene oxide content is about 40%; and Pluronic P123, a similar condensate having an average molecular weight of 5650, in which the propylene oxide nucleus has a molecular weight of about 4000, and the ethylene oxide content is about 30%. Even these detergents, although relatively low foaming by themselves, would fail to pass the foam test procedure hereinafter described. When combined with the low cloud point surface active agent and defoamer, however, the combination exhibits markedly reduced foaming.
The low cloud point surface active component can be one or more nonionic surface active agents having a cloud point below about 35 C., and preferably below 25 C., in 1% aqueous solution. It should contain ethylene oxide in the amount of 2-25 moles per molecule of surfactant, and the surfactant in turn should have a molecular weight of at least 300, or at least 1800 when the detergent contains both ethylene oxide and propylene oxide. The amount of low cloud point surfactant should be of the order of 5% to 100% of the weight of high cloud point surfactant in the composition.
Surface active agents with low cloud points are generally not phase stable, i.e. the separate or do not form homogeneous solutions, at product levels by themselves at temperatures above the cloud point, especially in compositions containing iodine, acids, water, etc. They do not dilute satisfactorily into aqueous solution at temperatures near or above their cloud point and, therefore, are totally unsatisfactory as single detergent constituents of cleaning compositions. In combination with the above mentioned type of high cloud point surface active agents, however, these adverse properties are overcome and the combination provides detergency and satisfactory dilution at temperatures within the 25 to 60 C. range.
Suitable low cloud point surface active agents falling within the limitation above described include ethoxylated nonylphenol and alcohols containing 2 to 4 moles of ethylene oxide, the E0 providing not more than 50% of the total weight, and a number of Pluronic type detergents which are condensates of ethylene oxide on a polypropylene oxide nucleus, and which contain less than 30% E0. Specific Pluronic type detergents which have been found satisfactory are:
Of these, Pluronic IJI22 is preferred in that it requires a minimum amount of solvent to form homogeneous solutions. Furthermore, in compositions containing iodine it provides the most iodine color at high use dilution.
The defoamer component can be one or more aliphatic monocarboxylic acids and/or aliphatic alcohols wherein the aliphatic radical contains 8 to 18 carbon atoms. At the upper end of this range the defoamers become increasingly resistant to solubilization both in 4 the product and in use dilutions, requiring the use of high concentrations of solvent; and at the lower end of the range the materials show reduced defoamer action (weight for weight). For these reasons aliphatic chains of 10 to 14 carbon atoms are preferred.
The amount of defoamer should be of the order of 1% to 50% of the weight of high cloud point surfactant in the composition. Furthermore, when the defoamer is an aliphatic carboxylic acid the composition should also contain an amount of mineral acid of the order of 1 to 20 times the weight of said high cloud point surfactant. Various mineral acids such as hydrochloric, sulfuric, and phosphoric acids can be employed, but phosphoric acid is preferred in view of its relatively low molecular weight, and very low toxicity. While the mineral acid is needed in compositions containing aliphatic carboxylic acid defoamer, it is not needed in compositions containing aliphatic alcohol defoamer. On the other hand, acid or extra acid can always be employed, if desired, to provide an acid cleaning action, or to enhance the stability of iodine in detergent-sanitizer compositions.
-As an optional component, particularly desirable with increased proportion of defoamer, the composition may contain a water soluble solvent containing at least one alcoholic OH group. Suitable solvents include ethyl alcohol, isopropyl alcohol, glycols such as ethylene, propylene, butylene and hexylene glycols, and glycol ethers such as the =butyl ether of ethylene glycol. The amount of solvent is suitably about 1 to 10 times the weight of the high cloud point surfactant, but not more than about 50% of the total composition. When both solvent and acid are present the combined amounts thereof should not exceed about of the total weight of the composition.
Preferred compositions according to the present invention are those having a combined low-foam detergent and sanitizer action. The nonionic surfactants above mentioned are complexing agents for iodine, and excellent sanitizing action is provided by incorporating in the composition a source iodine providing an amount of available iodine of the order of 5 to 50% of the combined weight of the high cloud point and low cloud point surfactants. The iodine can be introduced by dis solving elemental iodine in the surfactants, or preferably by adding to the surfactants an aqueous iodideiodine solution as described in US. Pat. No. 3,028,099.
When iodine is present, phosphoric acid, or mixtures of phosphoric and hydroxyacetic acids, provide enhancement of the iodine activity. It should be noted, however, that if the defoamer is an aliphatic monocarboxylic acid as above described, a minimum amount of phosphoric acid should be present in such acid mlxtures.
In acid formulations, either aliphatic acids or alcohols may be used as defoaming constituents. Aliphatic acids are preferred in those applications were food equipment is being cleaned. Aliphatic alcohols are preferred when highly alkaline waters are used to make dilutions. When the equipment to be cleaned is made of materials that corrode easily, such as aluminum, zinc or galvanized iron, then non-acid formulas with aliphatic alcohol are preferred.
In alkaline formulations, Where caustic, silicates, phosphates, carbonates, etc. are ingredients, then aliphatic acids cannot be used at all, and aliphatic alcohols are the materials of choice.
When the composition is intended for use in equipment which is not sensitive to acid, supplemental amounts of acid may be included to obtain the desired product performance. Thus Whether the defoamer is an aliphatic alcohol, or an aliphatic carboxylic acid with mineral acid, additional amounts of mineral acid or a carboxylic acid such as an hydroxyacetic, citric, lactic or malic acids may be used.
It follows from the foregoing that the present invention embraces four types of low-foam detergent compositions;
simple detergent compositions, acidic detergent compositions, sanitizer-detergent compositions containing iodine, and sanitizer-detergent compositions containing both acid and iodine. These compositions can be prepared for marketing in various concentrations with appropriate dilution schedules for preparing use solutions. As an aid to the reader in better visualizing the overall compositions the following tabulation is presented to embrace compositions intended for dilution with water at the rate of 1:640 (1 oz. per 5 gal. of water) in preparing use solutions.
High cloud point surfactant 3-12 Low cloud point surfactant 0.5-5 Aliphatic acid or alcohol defoamer 0.025-2.5 Available iodine -5 Acid 0-50 Solvent 0-50 Water to 100%.
The evaluation and testing of truly low-foam detergent compositions intended for C-I-P cleaning operations requires what has been referred to as a dynamic foam test procedure of the type described in US. Pat. No. 3,150,096 as follows:
150 ml. of the solution to be tested is placed in a 500 ml. calibrated gas washing bottle with fritted cylinder. Using an air flow meter, the air flow is adjusted to 2 liters per minute and the foam height is read after equilibrium has been established at a temperature of 25 C.
It has been found, however, that the equilibrium foam volume of 125 ml. is not the best measure of low foam correlation with actual results in the field. The test procedure has, therefore, been slightly modified as follows:
Through a 150 ml. sample of test solution in a 500 ml. gas calibrated washing bottle with fritted cylinder at a temperature of 25 C., or other desired temperature, air is passed at 2 liters per minute for 15 seconds, and the foam volume reached in that interval is recorded. The time required for this foam to collapse and fall to the liquid level is also recorded. Furthermore, since foam properties ordinarily vary with water hardness it is desirable to employ water to known hardness for comparative test purposes. A satisfactory standard, which is used in the examples hereinafter appearing, is made up with 3 parts by volume of distilled water and 1 part of AOAC 100 p.p.m. hard water.
As a guide to evaluating results with this revised dynamic foam test, it should be noted that:
(a) Compositions that overflow the gas washing bottle (approximately 440 ml. of foam when considering the volume above the calibrations) in less than 15 seconds are unsatisfactory. The time of overflow can be recorded, as well as the collapse time of the foam within the cylinder.
(b) Compositions which form a foam in 15 seconds and which take more than 1 minute to collapse are unsatisfactory.
(c) Compositions which provide foam volumes in 15 seconds of not more than 350 ml., and a foam collapse time of not more than 25 seconds are generally satisfactory. Suitably, however, the foam volume should be below about 200 ml. and the collapse time less than 15 seconds. With such performance, foaming is no longer a problem in dairy pipelines and other C-I-P equipment.
The ability of the new compositions to approach a temperature coefiicient of unity is diificult to explain even after finding that it is possible. The high cloud point surfactants by themselves foam excessively for use in C-I-P equipment; and the addition of defoamer causes foam reduction principally at relatively low temperatures, with an increase in foam at elevated temperature. The low cloud point surfactant appears to act as a foam inhibitor for the high cloud point surfactant at elevated tempera- Amount by wt., percent 5 ture, while the latter acts to solubilize the former above its cloud point.
What appears to be happening in the new compositions is that two of the components, i.e. the low-cloud point surfactant and the fatty acid or alcohol, behave as inversely related defoamers, while at the same time contributing a detergent action at temperatures when the respective defoaming actions are reduced. It is therefore considered that the essential components, i.e. the high and low cloud point surfactants, the aliphatic acid or alcohol, and the mineral acid (when needed) as herein described, provide a most unique and synergistic cooperation in the new compositions.
The following examples will serve to more fully disclose the preparation and performance of preferred compositions in accordance with the present invention, but it is to be understood that these examples are given by way of illustration and not of limitation.
EXAMPLE I For comparative purposes a number of detergent-sanitizer compositions were prepared containing (by weight) 3.3% HI-I solution (providing 1.75% available iodine), 40% H PO (anhydrous basis), 30% butyl Cellosolve, one or more (as indicated) of the following components:
7% Pluronic L35 2% Pluronic L122 1% C aliphatic carboxylic acid Water to These compositions were diluted 1:640 v./v. in water consisting of 3 volumes of distilled water and 1 volume of 100 p.p.m. AOAC hard water, and subjected to foam tests by the dynamic foam test procedure herein described with the following results:
to 1I0S6)7Dl0py1 alcohol, rather than water, was used to bring this sample up 2 This sample dissolved with the greatest difficult Unsuitable for product use Without the high cloud point constituent. y
This unified presentation shows that the high cloud point surfactant alone 1 foams excessively at room temperature; the foaming increases at the higher temperature, even though the collapse time decreases somewhat. In example 2, L122 is shown to foam excessively at room temperature. The C acid alone, 3, foams slightly owing to its surface activity. It is surprising that it can do much to defoam any of the other constituents. In 4 we see that L122 alone cannot act as a defoamer even at the higher temperature, whereas the C acid alone in 5 cannot do a satisfactory job by itself with the high cloud point constituent. The C acid can defoam the low cloud point constituent, 6, but the combination dissolves so slowly in water that it cannot be considered for use. When the high cloud point surfactant, low cloud point surfactant and C acid are combined, as in 7, this provides a very successful product. 7
EXAMPLE II Compositions are prepared similar to composition 7 in Example I in which the 40% phosphoric acid component is varied as indicated in the following tabulation, and the several compositions are subjected to foam testing with the results shown. (Acid percentages are on anhydrous basis.)
Use dlln. Foam, Collapse, Foam, Collapse, Acid pH ml./see. sec. ml./see. sec.
(7) 40% H3PO4 2. 5 75/15 8 110/15 7 (8) 30% H PO 2. (i 250/15 11 150/15 9 (1) 15% H PO 2. 75 275/15 21 225/15 12 (10) 7.5% H PO4 3. 35 325/ 120 350/15 10 (11) None 6. 6 440/13 120 440/10 120 (12) 22% IIJPOA, 21%
hydroxyacetic 2. 7 275/15 9 200/15 7 (13) 10% H01 2. 5 150/15 15 150/15 l1 (14) 37% hydroxyacetic 2. 8 850/15 120 (15) citric 3. 0 375/15 120 From the above data it can be seen that phosphoric and hydrochloric acids, mineral acids, were necessary to insure the effectiveness of the defoaming system. Neither hydroxyacetic acid nor citric acid alone, carboxylic acids, were satisfactory, but a mixture of a mineral acid and a carboxylic acid was satisfactory. In other experiments, a wide range of mixtures of phosphoric acid with carboxylic acids were found satisfactory. In general, where a product use dilution of 1:640 was specified, a minimum of about 5% phosphoric acid, together with any additional amount of a carboxylic acid, was necessary for satisfactory periormance in the presence of an aliphatic carboxylic acid as a defoamer.
EXAMPLE III A number of compositions having the formulation indicated below were prepared and tested at 1:640 use dilu- These compositions when tested at 1:640 dilution by the dynamic foam test procedure above described, gave the following results:
A detergent composition was prepared as described in Example I containing:
tion as described in Example I giving the foam results Percent shown in the following tabulation: PlllrOHlC 4 6 Percent Pluronic L122 1 Pluronic L 7 pri aci (C10) 0.3 Pluronic L122 2 pri 11c a (C 0.2 HI-I 1 33 Available iodine 1,6 C fatty acid 0.2 p pylal ohol 20 C fatty acid 0.3 35 Ph phoric acid (75%) 53 Isopropyl alcohol 4 Water to 100%. Butyl Cellosolve 30 Acid anhydrous basis 2 In 1:640 use dllution foam test results at 25 C. were Water to 100% 150 mls. foam in 15 seconds which collapsed in 10 seconds;
at C., the foam volume was 175 mls. which col- 255212 311 avmlable lapsed in 8 seconds.
Use diln. Foam, Collapse, Foam, Collapse, Acid p ml./sec. sec ml./sec. soc.
(10) 40% Hiroi 2.5 175/15 13 125/15 5 17) No acid 6.6 440/15 120 440/12 120 l The use dilution pH was adjusted from an initial 3.00 to 2.5 using additional hydroxy acetic acid.
2 The use dilution pH was adjusted from an initial 3.05 to 2.5 using additional citric acid.
This data shows that the ineffectiveness of carboxylic acid alone, without mineral acid, is not a function of pH of the use dilution.
EXAMPLE IV Following the procedure described in Example I detergent compositions are prepared having the following compositions:
Percent Component A B Pluronic L35 7 7 Pluronic L122 1 1 Capric acid (C10) 0. 2 0. 2 Laurie acid (C11) 0.2 0.1 Available iodine. 1. 6 l. 6 Isopropyl alcohol 30 30 Phosphoric acid 53 53 Water, 100
EXAMPLE VI A detergent composition was prepared as described in Example I containing:
Water to 100% In 1:640 use dilution foam test results at 25 C. were mls. foam in 15 seconds which collapsed in 7 seconds; at 60 C., the results were substantially the same.
9 EXAMPLE VII Compositions containing fatty acid defoamer, but containing no iodine, were prepared according to the following formulation, and foam tested at 1:640 dilution as EXAMPLE VIII Compositions were prepared with different low cloud point surfactants, as indicated, and subjected to foam testing at 1:640 dilution as described in Example I giving l 0 EXAMPLE X A composition was prepared having the composition indicated below employing as the high cloud point surfactant a Pluronic type surfactant consisting of a polyoxypropylene base having a molecular weight of about 1200 condensed with ethylene oxide to provide approximately 35% of the weight of the surfactant.
7% Special surfactant described above, cloud pt. 45 C.
1% Pluronic L122 0.1% Laurie acid 0.3% Capric acid 3.3% HI-I, (provides 1.75% available iodine) 40% I'IgPOg 4% Isopropyl alcohol 30% Butyl Cellosolve To 100% water Using the same test conditions previously described, this composition gave 125 ml. foam in 15 seconds at C. and took 5 seconds to collapse; at 60 C., it gave 200 ml. of foam which took 12 seconds to collapse.
EXAMPLE XI A composition was prepared having the formulation indicated below:
the results tabulated below: Percent Pluromc P123 (cloud pt. 90 C.) 2 Pluromc L35 7 Pluronic L122 1 Low cloud point surfactant (1) Capric acid 1 Capnc a d 1 Phosphoric acid 40 Phosphoric acld 40 Isopropyl alcohol 4 p py alcohol 4 Butyl Cellosolve 30 Butyl Cellosolve 30 Water to 100% Water to 100%.
1A5 given below When tested by the dynamo foam test at 1:640 dilu- 1 d po ir i t, Foam, Collapse, Foam, Collapse, Low cloud point surfactant mL/sec. sec. mL/sec. sec.
2% Pluronic L122 19 60/15 2 25/15 2 2% Pluronic L51- 24 75/15 2 50/15 2 2% Pluronic L52.-- 32 100/15 4 50/15 2 0.5% Pluronic L81 20 75/15 3 75 15 2 2% Pluronic L02- 25 15 2 15 2 0.5% Pluronic L101 15 70 15 2 90 15 2 3% nonylphenol+4 E0 15 200/15 15 150/15 12 2% lauryl alc.+2 E0 15 175/15 15 150/15 10 Q EXAMPLE IX tion under the test conditions previously described, the
50 following results were obtained:
Compositions similar to those in Example VIII, but containing a different high cloud point surfactant, were prepared and foam tested at 1:640 dilution as described in Example I with the following results:
Percent Pluronic L35 and Pluronic L44, having cloud points of 76 C. and 6 5 C. respectively are preferred high cloud point surfactants. The following examples, however, and presented to show the performance with surfactants of somewhat higher and lower cloud points.
Foam, Collapse, Temp. C. mlJsec. sec.
The examples thus far have employed aliphatic carboxylic acids as the defoaming component. The following examples relate to similar compositions containing aliphatic alcohols, or mixtures of aliphatic acid and alcohol as the defoaming component. When only aliphatic alcohol is employed the mineral acid is not necessary; in fact it is possible to prepare alkaline cleaners as shown in Example XIV. On the other hand acid can be added, and the presence of acid generally improves performance. Such acid can be a mineral acid such as phosphoric, sulfuric or hydrochloric acid, or carboxylic acids such as hydroxyacetic, citric, lactic, or malic acid, or mixtures thereof.
EXAMPLE XII Compositions were prepared having the formulations indicated below and subjected to foam testing at 1:640 dilution in the manner previously described giving results as shown in the following tabulations.
Percent A B C D E lluronic L35 7 7 7 7 7 Pluronic L122. 2 2 2 2 2 Phosphoric acid. None None 40 40 40 Available iodine None 0. 4 1. 75 1. 75 1. 75 Tridecyl alcoholl 1 1 0. 5 0.3 Isopropyl alcohol 4 4 4 4 4 Butyl Cellosolve- 30 30 30 3O 30 Water, to 100 100 100 100 100 Foam, Collapse, Foam, Collapse, pH ml./see. sec mL/sec. sec.
EXAMPLE XIII A series of compositions was prepared each containing by weight 7% Pluronic L35, 2% Pluronic L122, 40% H PO and 1.75 available iodine, together with aliphatic alcohol of the type and amount indicated below, plus 4% isopropyl alcohol and butyl Cellosolve, the balance to 100% being water. These compositions, at 1:640 dilution, were subjected to foam testing as in Example I giving the results tabulated below.
An alkaline composition was prepared containing by weight:
Percent Pluronic L 7 Pluronic L122 2 Tridecyl alcohol 0.5 Sodium hydroxide 2 Butyl Cellosolve Water to 100% This composition at 1:640 dilution showed a pH of 10.5, and gave the following foam test results:
Foam, ml./sec. Collapso,see.
EXAMPLE XV A composition of the following formulation, containing both fatty acid and fatty alcohol as defoamer, was prepared and tested for foaming at 1:640 dilution with the results indicated below:
Percent Pluronic L35 7 Pluronic L122 2 Decyl alcohol 0.5 Capric acid 0.5 HI-I 1 3.3 Phosphoric acid 40 Isopropanol 34 Water to 100%.
Provides 1.75% av. 12.
Temp., C. Collapse, see.
(a) a nonionic surface active component having a cloud point above 45 C. in a 1% aqueous solution, a molecular weight in the range of 1800 to 6000, and containing both propylene oxide (PO) and ethylene oxide (E0) groups with the molecular weight of PO being at least 800, and the E0 being not more than 65% by weight of said component,
(b) an amount of the order of 5 to by weight of component a, of a nonionic surface active component having a cloud point below 35 C. in a 1% aqueous solution and containing 2 to 25 moles of EO per molecule of said nonionie component, and said nonionie component having a minimum molecular weight of 300,
(c) an amount of the order of l to 50% by weight of component a, of a component selected from the group consisting of unsubstituted aliphatic monocarboxylic acids and unsubstituted aliphatic alcohols wherein the aliphatic radical contains 8 to 18 carbon atoms, and
(d) when said composition contains aliphatic monocarboxylic acid as component c, an amount of the order of 1 to 20 times the weight of component a of a mineral acid selected from the group consisting of hydrochloric acid, sulfuric acid and phosphoric acid, said detergent composition being characterized in that the nature and degree of foaming it exhibits at temperatures of from about 25 to 60 C. is substantially uniform such that it provides a substantially unitary temperature coefficient.
2. Low foam detergent composition as defined in claim 1 wherein component c is capric acid.
3. Low foam detergent composition as defined in claim 1 wherein component c is decyl alcohol.
4. Low foam detergent composition as defined in claim 1 wherein component 0 is tridecyl alcohol.
5. Low foam detergent composition as defined in claim 1 wherein component c is an aliphatic alcohol, and said composition contains an additive selected from the group consisting of caustic, alkaline salts, and mixtures thereof to provide an alkaline formulation.
6. Low foam detergent composition as defined in claim 1 wherein the nonionic surface active agent of component a has a cloud point above 55 C., the nonionic surface active agent of component b has a cloud point below 25 C., the aliphatic radical of component c contains 10 to 14 carbon atoms, and the mineral acid employed as component d is phosphoric acid.
7. Low foam detergent composition as defined in claim 1 wherein component b has a minimum molecular weight of 1800 when both EO and PO groups are present.
8. Low foam detergent composition as defined in claim 7 wherein component b is a nonylphenol-ethylene oxide condensate.
9. Low foam detergent composition as defined in claim 7 wherein component b has a base of polyoxypropylene having ethylene oxide condensed therewith.
10. Low foam detergent composition as defined in claim 1 wherein the nonionic surface active agent of component a is a condensate of polyoxypropylene having a molecular weight of about 950 with an amount of ethylene oxide to provide about 50% of the weight of said nonionic surface active agent, and component b is a condensate of polyoxypropylene having a molecular Weight of about 4000 with an amount of ethylene oxide to provide 20% of the weight of said nonionic.
11. Low foam detergent composition as defined in claim 1 wherein the nonionic surface active agent of component a is a condensate of polyoxypropylene having a molecular weight of about 1200 with an amount of ethylene oxide to provide about 40% of the weight of said nonionic surface active agent, and component b is a condensate of polyoxypropylene having a molecular weight of about 4000 with an amount of ethylene oxide to provide 20% of the Weight of said nonionic.
12. Low foam detergent composition as defined in claim 1 wherein said composition includes a source of iodine in an amount sufficient to provide a quantity of available iodine of from about 5 to 50% of the combined Weight of components a and b.
References Cited UNITED STATES PATENTS 2,759,869 8/1956 Sutton et al. 252-107 X 2,855,367 10/1958 Buck 252-138 14 2,969,332 1/1961 Lawler et al. 254-354 3,029,183 4/1962 Winicove 424150 3,156,655 11/1964 Bright 252-109 3,215,635 11/1965 Liebling et a1 252-321 3,150,096 9/1964 Schmidt et a1. 252-106 3,382,176 5/1968 Jakobi et al. 252-89 FOREIGN PATENTS 580,341 7/1959 Canada 252-89 1,089,905 9/ 1960 Germany 252-89 800,159 8/ 1958 Great Britain 252-89 808,945 2/ 1959 Great Britain 252-138 922,252 3/ 196-3 Great Britain 252-99 683,413 3/1964 Canada 252-137 OTHER REFERENCES Journal of Colloid Science, The Defoaming of Synthetic Detergent Solutions by Soaps and Fatty Acids, Peper, 13, 199-207 (1958).
LEON D. ROSDOL, Primary Examiner P. E. WILLIS, Assistant Examiner US. Cl. X.R.
TJNTTTED STATES PATENT oTTTcE QEHHCATE F RETWN Patent No. 3: 5 99 5 Dated v Mafch 97 lnventofls) Abraham Cantor, at a].
It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected asshown below:
Colman 2 lino 37, "forming" should read foaming lino 4 "predominate" should read predominant Column 3, line 3 4, "the" should read they Column 4-, line 17, "3,028,099" should read 3,028,299 line 57, "were" should read M where Column 9, line 7%, "and" should read m are Column 11', line 23, "1.75" should read l 35% Signed and sealed this 7th day of November 1972,,
EDWARD MQFLETCHERJR. RQBERT GOTTSCHALK Attoating Officer Commiaaionor of Patents F ORM PO-1050 (10-69) USCOMM-DC 603764 69 U.5 GOVERNMENT PRINTING OFFICE: 1965 0-366-334,