CA1227715A

CA1227715A - Foam control

Info

Publication number: CA1227715A
Application number: CA000453180A
Authority: CA
Inventors: Ahmet C. Ozmeral
Original assignee: BASF Corp
Current assignee: BASF Corp
Priority date: 1983-06-27
Filing date: 1984-04-30
Publication date: 1987-10-06
Also published as: US4510067A

Abstract

FOAM CONTROL
Abstract of the Disclosure The instant invention relates to compositions containing (a) a high-foaming nonionic surfactant and (b) a foam reducing amount of a polyoxyalkylene compound of the formula:

Y[(A)m-(B)nH]2 wherein Y is the residue formed by the removal of two atoms of active hydrogen from an initiator having a total of not more than 20 carbon atoms, preferably butanediol; A is a hydrophobic, heteric mixture of an oxytetramethylene radical, derived from tetramethylene oxide and a vicinal alkylene oxide radical derived from propylene oxide, B is primarily C2H40, n is an integer such that the total weight of said B is about 5 to about 40 percent by weight of the total oxyalkylene residue weight of the compound and the total molecular weight of the hydrophobe, 2m is about 1000 to 3000.

Description

i227715 case 13 8 3 FOAM CONTROL
Background of the Invention 1. Field of the Invention This invention relates to low-foaming compositions which incorporate therein normally high-foaming non ionic surfactants. More specifically, this invention is directed to the reduction or suppression of foaming in compositions containing normally high-foaming non ionic surfactants.

2. Description of the Prior Art Although detergency has been associated in the minds of many with high foam level, in Rome situations foam is an objectionable feature of detergents. For example, in automatic laundry and dish washing machines that produce a high degree of agitation, excessive foam interferes with the cleaning operation and causes overflow. Unfortunately, many surfactants, and particularly many non ionic surfactants, which are desirable for such application are characterized by high foaming and thus by themselves are not suitable for applications such as automatic laundry and dish washing machines. Accordingly, it is known in the prior art to mix low-foaming non ionic surfactants with the high-foaming surfactants as foam control agents.
U. S. Patent 3,862,243, hellos, discloses oxyethy-fated then oxybutylated alcohols having the general formula R(OEt)(OBu)OH where R is a hydrocarbon group preferably from ~227~

about 6 to 22 carbon atoms. These oxyalkylated alcohols are employed as antifoamers, however, there it no mention of using these compounds as defamers for high-foaming non ionic surfactants.
An article by Kuwamura et at, Journal American Oil Chemists Society, I pp. 29-34 (1971), entitled "Surface Active Block Copolymers: 1. The Preparation and Some Surface Active Properties of Block Copolymer~ of Tetrahydro-Furman and Ethylene Oxide," discloses surface active block copolymers which are indicated as effective antifoamers for anionic detergents but inefficient for non ionic solutions.
Summary of the Invention The instant invention relate to compositions containing (a) a high-foaming non ionic ~urfactant and (b) a foam reducing amount of a polyoxyalkylene compound of the formula:

Ye -(B) H]

wherein Y is the residue formed by the removal of two atoms of active hydrogen from an initiator having a total of not more than 20 carbon atoms and free of elements other than carbon, hydrogen and oxygen, said initiator preferably being selected from the group consisting of water, alkaline glycols, polyalkylene glycols, alkanols, and, most prefer-~22~7~5 ably, 1,4-butanediol: A is a hydrophobic, heteric mixture of an oxytetramethylene radical, derived from tetramethylene oxide and a vicinal alkaline oxide radical derived from propylene oxide, said A being derived from the reaction of said oxides in the molar ratio of tetramethylene oxide:
vicinal alkaline oxide of 3:1 to 1:1, B is primarily KIWI, m is an integer such that the total weight of said A is about 95 to 60 percent by weight of the total oxyalkylene residue weight of the compound; n is an integer such that the total weight of said B is about 5 to 40 percent by weight of the total oxyalkylene residue weight of the compound and the total molecular weight of the hydrophore, em is about 1000 to 3000.
The hydrophore A may optionally but advantageously contain small amounts up to 30 percent by weight of oxyethy-tone and/or oxybutylene groups while the hydrofoil B may also optionally but advantageously contain oxypropylene and oxybutylene groups in amount up to 30 weight percent of the total hydrophilic portion of the molecule. As used herein, reference to the hydrophobic groups, or group A, is concede-eyed to include such optional groups even though not specifically mentioned and, similarly, reference to the hydrophilic groups or group B is considered to possibly include such oxypropylene or oxybutylene groups. The preparation of the compounds of the type set forth in the lZ277~ 5 above formula is described in more detail in U. S. Patent 4,183,821.
Detailed Description of the Invention The high-foaming non ionic surfactants which are used in the instant invention may be any suitable member of any of the generally known types of non ionic ~urfactants, i.e., alkoxylated alkyd phenol, oxyalkylated fatty acids, oxyalkylated fatty alcohols, alkoxylated fatty amine, oxyalkylated fatty sorbitan esters, block copolymers containing En and PO units based on ethylene glycol or propylene glycol, block copolymers containing En or Pi units based upon N,N,N',N',-tetrakis(2-hydroxypropyl)ethylene Damon, etc.
As used herein, a n---high-foaming, non ionic surfactant---n is one which will reach a foam height of 600 mm within ten minutes at a flow rate of 400 ml per minute when tested with a dynamic foam machine such as the one described by Reich et at in Soap and Chemical Special-ties, vol. 37, page 55, (April, 1961). Those of ordinary skill in the art will know which block copolymers that are alkoxylation products of ethylene glycol or propylene glycol are high framers. They will also know how to prepare such surfactants. Such surfactants are generally employed in various proportions with other ingredients in the nature of abrasives, fillers, dyes, perfume, soil, anti redeposition lZ277~ 5 agents, optical brightness, etc. to form completed cleaning compositions.
The high-foaming nonionics to which this invention is particularly applicable correspond to the formula:

Ye (C3H60)n (C2H4)m ox wherein Y it the residue of an organic compound having from about 1 to 6 carbon atoms and containing x reactive hydrogen atoms in which x has a value of at least about 1, n has a value such that the molecular weight of the polyoxypropylene hydrophobic base is about 1500 to 5000 and m represent from about 30 to 90 weight percent of the molecule. Falling within the scope of the definition for Y are, for example, propylene glycol, glycerine, pentaerythritol, trimethylol-propane, ethylene Damon and the like. The oxypropylene chains optionally, but advantageously, contain small amounts of oxyethylene and oxybutylene groups and the oxyethylene chains also optionally, but advantageously, contain small amounts of oxypropylene and oxybutylene groups. These compositions are more particularly described in U. S. Patent Nos. 2,677,700 and 2,674,619.
Nonionics to which this invention is particularly applicable are those wherein Y it propylene glycol, wherein the resulting formula is i2;277~5 H(c2H4o)m(c3H6o)n(c2H4o)m wherein n has a value such that the molecular weight of the polyoxypropylene hydrophobic base is about 1800 to 3200 and m has a value such that the oxyethylene content of the molecule it from about 30 to 90 weight percent.
Another preferred non ionic ~urfactant is one wherein Y is the residue of ethylene Damon wherein the resulting formula is H(C2H4)m(C3H60?n /(C3H60)n(C2H40)m N - OH - OH - N
H(C2H4)m(C3H60)n (C3H60)n(C2H40)m wherein n has a value such that the molecular weight of the polyoxypropylene hydrophobic base is from about 1500 to 5000, and m has a value such that the oxyethylene content of the molecule is from about 30 to I weight percent.
The manner of using the foam-reducing agent by incorporating it in a foam reducing amount, as designated above, in a dish washing, laundry or other detergent compost-lion requiring low-foam characteristics is well known to those skilled in the art. Such a composition will contain, as indicated above, a substantial proportion of the high-~ZZ77~5 foaming non ionic surfactant. Thus, in one aspect, the present invention comprises a composition consisting of a high-foaming, non ionic ~urfactant into which there has been incorporated a suitable amount of the tetrahydrofuran, propylene oxide, ethylene oxide compound, as described above, the amount being such as to provide a ratio of the tetrahydrofuran compound to high-foaming, non ionic of 0.5:10 to 2.0:10 by weight. In other words, the tetrahydrofuran, alkaline oxide compound may simply be added to the high-foaming, non ionic surfactant in order to make it a lower foaming product in whatever composition it may ultimately be used, or the invention may be practiced by making a compost-lion for a particular end use in which the high-foaming, non ionic surfactant and the tetrahydrofuran, alkaline oxide compound are added as separate ingredients.
The amount of the tetrahydrofuran, alkaline oxide compound used is defined functionally as a "foam-reducing amount." For the purposes of the present invention, the term "foam-reducing amount" may be defined as one not exceeding 20 percent by weight of the high-foaming, non ionic surfactant.
The compositions of this invention may also contain other ingredients such as other surfactants, builders, bleaches, abrasives, fillers, dyes, perfumes, soil anti-redeposition agents, optical brighteners, etc. The ~2~77~5 amounts of these components in a detergent or cleaning composition are from about S to 90 percent by weight. When used for washing purposes in either a dish washing or laundry solution, such solution will contain about 0.1 to 5 and preferably 0.1 to 0.5 percent by weight of the total detergent composition, balance water. For convenience in handling, transportation and marketing, a dry or liquid concentrate may be prepared comprising about 20 to 60 percent by weight of the above detergent composition, balance inert ingredients such a sodium sulfate for a dry concentrate or water for a liquid concentrate.
The examples which follow illustrate in more detail the practice of the instant invention. Unless otherwise indicated, all temperatures are in degrees centigrade and all parts, percentages, etc., are by weight.

12Z~71~

Example 1-6 In these examples a high-foaming, non ionic surfactant indicated in the Table below as non ionic No. 1 was tested alone and in combination with five other non-tonics. Non ionic No. 1 is the poiyoxyethylene adduce of a polyoxypropylene hydrophobic base having a molecular weight of the hydrophobic base of about 1750 and wherein the oxyethylene content is about 80 weight percent of the molecule.
The five other nonionics may be defined as follows:
Non ionic No. 2 is the polyoxyethylene adduce of a polyoxypropylene hydrophobic base having a molecular weight of about 1750 for the hydrophobic base and wherein the oxyethylene content is about 10 weight percent of the molecule.
Non ionic No. 3 it the polyoxyethylene adduce of a polyoxypropylene condensed with ethylene Damon wherein the oxypropylene hydrophobic base has a molecular weight of about 2500 and the oxyethylene content is about 10 percent by weight of the molecule.
Non ionic No. 4 is the polyoxyethylene adduce of a polyoxypropylene condensed with ethylene Damon wherein the oxypropylene hydrophobic base ha a molecular weight of about 4500 and the oxyethylene content is about 10 weight percent of the molecule.

g _ -1227~ 5 Non ionic No. S it the polyoxyalkylene compound having the following formula:

Ye -(B) H]

wherein Y it the residue formed by the removal of two atoms of hydrogen from 1,4-butanediol, A it a hydrophobic heteric mixture of an oxytetramethylene radical derived from tetrahydrofuran and a vicinal alkaline oxide radical derived from propylene oxide in the molar ratio of tetramethylene oxide:vicinal alkaline oxide of 1:1, B is an oxyethylene chain, m it an integer such that the total molecular weight of A it about 2000 and n is an integer such that the weight of B is 30 percent of the total molecular weight of the compound.
Non ionic No. 6 it the polyoxyalkylene compound having the following formula:

yeomen I

wherein Y it the residue formed by the removal of two atoms of hydrogen from l,4-butanediol, A it a hydrophobic heteric mixture of an oxytetramethylene radical derived from tetrahydrofuran and a vicinal alkaline oxide radical derived from propylene oxide in the molar ratio of tetramethylene ~;~27715 oxide:vicinal alkaline oxide of 1:1, B is an oxyethylene chain, m is an integer such that the total molecular weight of A it about 5000 and n is an integer such that the weight of B is 20 percent of the total molecular weight of the compound.
In the examples which follow, the compositions indicated in the Table as No. 1 through 6 were each diluted with water to form an aqueous solution containing 0.1 percent by weight of the composition. The foaming power of the compositions was measured by using a dynamic foam machine such as the one described by Reich et at, Soap and Chemical Specialties, vol. 37, page 55, (April, 1961). The result of these tests are given in the table below. The table shows that foam heights were measured using a 400 cc per minute flow. The foam height of each composition at intervals of 0.5, 2, 5 and 10 minutes of flow are shown in the Table.

1~27715 TABLE

Dynamic Foam Height (mm) 400 cc/min., 120F
No. Composition min. 2.0 min. 5 0 min. 10.0 min.
1 100% Non ionic No. 1 140 460 600 2 90% Non ionic No. 1 50 90 135 160 10% Non ionic No. 2

3 90% Non ionic No. 1 45 60 70 75 10% Non ionic No. 3

4 90% Non ionic No. 1 60 105 165 260 10% Non ionic No. 4 90~ Non ionic No. 1 40 45 50 50 10% Non ionic No. 5 6 90% Non ionic No. 1 55 85 130 170 10% Non ionic No. 6 The only defamer within the scope of the invent lion is non ionic No. 5 from which it can be seen that greatly reduced foam heights are achieved as compared to nonionics Nos. 2, 3, 4 and 6. Nonionics 2, 3 and 4 are well known prior art low-foaming nonionics while non ionic No. 6 is a tetrahydrofuran based polyoxyalkylene compound of the formula employed according to this invention but it has a molecular weight of the hydrophore of 5000 which is greatly in excess of the 3000 molecular weight maximum permissible according to the instant invention. Thus, the superior 122~715 foam-reducing properties of the instant invention are clearly shown by these Examples.
Example 7 A detergent composition is prepared consisting of by weight 12.0 percent non ionic No. 1, 1.0 percent non ionic No. 5, 40 percent sodium citrate; 1.0 percent carboxymethyl-cellulose, 0.5 percent perfume and 45.5 percent sodium sulfate.
A washing solution for laundry purposes is prepared by mixing the detergent composition of Example 2 with water in amount of 0.15 percent by weight of the detergent composition, balance water. This washing solution is characterized by low-foaming when used in an automatic washing machine and has good cleaning properties.
Example 8 A detergent composition similar to Example 7 is prepared wherein a non ionic surfactant as described for non ionic No. 5 but having a molecular weight of the polyoxy-propylene groups of 3000 and containing 20 percent by weight oxyethylene groups is substituted for non ionic No. 5. A
washing solution prepared from this detergent composition containing 0.15 percent by weight of the detergent compost-lion, balance water, when employed for washing clothes in an automatic washing machine exhibits low-foaming properties and excellent cleaning.

7~5 Example 9 A detergent composition similar to Example 7 is prepared wherein a non ionic surfactant a described for non ionic No. 5 but having a molecular weight of the polyoxy-propylene groups of 1000 and containing 40 percent by weight oxyethylene groups it substituted for non ionic No. 5. A
washing solution prepared from this detergent composition containing 0.15 percent by weight of the detergent compost-lion, balance water, when employed for washing clothes in an automatic washing machine exhibits low-foaming properties and excellent cleaning.
Example 10 A composition similar to Example 7 is prepared with the exception that a non ionic similar to non ionic No. 1 having a molecular weight of the hydrophore of about 2250 and containing 40 percent by weight oxyethylene groups is substituted for non ionic No. 1. A washing solution prepared from this detergent composition containing 0.15 percent by weight of the detergent composition, balance water, when employed for washing clothe in an automatic washing machine exhibits low-foaming properties and excellent cleaning.

Claims

The embodiments of this invention in which an exclusive property or privilege is claimed are defined as follows:

1. A composition comprising (a) a high-foaming, nonionic surfactant and (b) a foam-reducing amount of a polyoxyalkylene compound having the formula Y[(A)m-(B)nH]2 wherein Y is the residue formed by the removal of two atoms of active hydrogen from an initiator having a total of not more than 20 carbon atoms and free of elements other than carbon, hydrogen and oxygen, A is a hydrophobic, heteric mixture of an oxytetramethylene radical, derived from tetramethylene oxide and vicinal alkylene oxide radical derived from propylene oxide, said A being derived from the reaction of said oxides in the molar ratio of tetramethylene oxide:vicinal alkylene oxide of 3:1 to 1:1, B is C2H4O; m is an integer such that the total weight of said A is about 95 to 60 percent by weight of the total oxyalkylene residue weight of the compound. n is an interger such that the total weight of said B is about 5 to 40 percent by weight of the total oxyalkylene residue weight of the compound and the total molecular weight of the hydrophobe, 2 m is about 1000 to 3000.

2. The composition of claim 1 wherein said high-foaming, nonionic surfactant has the following formula y[(C3H60)n(C2H40)mH]x wherein Y is the residue of an organic compound having from about 1 to 6 carbon atoms and containing x reactive hydrogen atoms in which x has a value of at least about 1, n has a value such that the molecular weight of the polyoxypropylene hydrophobic base is about 1500 to 5000 and m represents about 30 to 90 weight percent of the molecule.

3. The composition of claim 2 wherein said high-foaming, nonionic surfactant is selected from the group consisting of compounds having the formula H(C2H40)m(C3H60)n(c2H4O)mH

wherein n has a value such that the molecular weight of the polyoxypropylene hydrophobic base is about 1800 to 3200 and m has a value such that the oxyethylene content of the molecule is from about 30 to 90 weight percent.
and compounds having the formula:
-IMAGE-wherein n has a value such that the molecular weight of the polyoxypropylene hydrophobic base is from about 1500 to 5000, and m has a value such that the oxyethylene content of the molecule is from about 30 to 90 weight percent.

4. The composition of claim 3 wherein the initiator of said tetramethylene oxide-propylene oxide compound is a butane diol.

5. The composition of claim 4 wherein the weight ratio of said tetramethylene oxide-propylene oxide compound to high-foaming nonionic is from about 0.5:10 to 2:10.

6. The composition of claim 5 including about 5 to 90 percent by weight conventional detergent additives.

7. A detergent concentrate comprising 20 to 60 percent by weight of the detergent composition of claim 6, balance inert ingredients or water.

8. A washing solution comprising 0.1 percent to 5 percent by weight of the detergent composition of claim 6, balance water.

9. A method of reducing foaming of a high-foaming, nonionic surfactant which comprises adding thereto a tetrahydrofuran based polyoxyalkylene compound having the structural formula:

y[(A)m-(B)nH]2 wherein Y is the residue formed by the removal of two atoms of active hydrogen from an initiator having a total of not more than 20 carbon atoms and free of elements other than carbon, hydrogen and oxygen, A is a hydrophobic, heteric mixture of an oxytetramethylene radical, derived from tetramethylene oxide and a vicinal alkylene oxide radical derived from propylene oxide, said A being derived from the reaction of said oxides in the molar ratio of tetramethylene oxide:vicinal alkylene oxide of 3:1 to 1:1,B is C2H4O. m is an integer such that the total weight of said A is about 95 to 60 percent by weight of the total oxyalkylene residue weight of the compound, n is an integer such that the total weight of B is about 5 to 40 percent by weight of the total oxyalkylene residue weight of the compound and the total molecular weight of the hydrophobe, 2 m is about 1000 to 3000, the ratio of said tetrahydrofuran based polyoxyalky-lene compound to said high-foaming, nonionic surfactant being from about 0.5:10 to 2:10.