Sterically Hindered Polyether Polyols as Chlorine Bleach Stable Surfactants

1. Field of the Invention

In the art of cleaning compositions for use in cleaning hard surfaces, particularly the art of cleaning tableware and other food-soiled utensils in machine dishwashers, the problem of spotting, filming and defoaming of the machine washload is present. Liquid detergent compositions were introduced to the market and offered ease and convenience of handling. Since their introduction, such detergent compositions have captured upwards of 30 percent of the home market. However, these liquid detergent compositions have suffered certain deficiencies relative to powdered machine dishwashing detergents. Specifically, although they offer ease of manufacture and handling, they have inferior spotting, filming and defoaming characteristics relative to the powdered compositions.

It is believed that these deficiencies are the result of the fact that most detergent compositions contain a chlorine bleach component, such as hypochlorite bleach, and these chlorinating agents degrade conventional defoaming nonionic surfactants such as ethylene oxide/propylene oxide block copolymers and fatty alcohol, fatty acid, fatty amide and alkyl phenol oxyalkylates. As the chlorinating agent attacks the nonionic surfactant, the bleach is depleted and the surfactant is destroyed. Thus, spotting, defoaming and filming properties are lost along with the properties of the chlorinating agent.

In the past, liquid automatic dishwashing detergent compositions have been formulated with anionic surfactants such as alkyl diphenyloxide disulfonates, or with no surfactants present at all. The use of anionic surfactants or no surfactants in liquid automatic dishwashing detergent compositions contributes greatly to the spotting, filming and defoaming problems associated with such liquid compositions. Thus, there is a greatly felt need in the industry to formulate a liquid, automatic dishwashing detergent composition which contains nonionic surfactants and which do not break down under attack from chlorinating agents which may be present in the composition.

The present invention relates to the use of sterically hindered epoxide-capped polyether polyols as nonionic surfactants in cleaning formulations which include alkaline hypochlorite bleaching agents. The use of such polyols allows such formulations to retain their cleaning and defoaming properties for longer periods than formulations containing conventional nonionic polyether surfactants.

2. Description of the Related Art

Mori et al, U.S. Pat. No. 4,703,114, disclose polyethers having tertiary alcoholic terminals. The polyethers are of the formula: ##STR1## wherein:

R is the residue of a starting active hydrogen compound with removal of the active hydrogen atom, R.sub.1 is a C.sub.1 -C.sub.10 alkyl or aryl, R.sub.2 is a C.sub.1 -C.sub.10 alkyl, R.sub.3 is H, CH.sub.3, C.sub.2 H.sub.5 or phenyl, x is 5 to 100, y is 1 to 5, and z is 1 to 8.

These polyethers are less active than those having primary or secondary alcoholic functions at their terminal ends. These hydroxyl terminated polyethers find use as raw materials for polyurethane and polyester resins and are suggested for use in cosmetics, plasticizers, surfactants and raw materials for these products.

In the preparation of the polyethers, the starting active hydrogen compounds include monohydroxyl compounds or polyhydroxyl compounds such as propylene glycol. About 5 to 100 moles per active hydrogen atom of alkylene oxide and/or styrene oxide may be reacted with the starting active hydrogen compound to give polyethers. When these polyethers contain different recurring units, these units may form either random or block copolymers. The polyethers can be reacted with 1 to 5 moles per hydroxyl group of an epoxide. Preferred epoxides include isobutylene oxide.

There is no showing in Mori et al that these materials exhibit unexpected stability in the presence of chlorine bleach while retaining spotting, defoaming and filming properties in liquid detergent compositions which are comparable with powdered detergents.

Horsley et al, U.S. Pat. No. 2,886,600, relate to the production of isobutyl ethers of hydroxy compounds, and particularly to the production of isobutyl ethers of glycol and polyglycol monoethers.

There is no showing that these compounds make excellent nonionic surfactants which exhibit surprising stability in detergent compositions containing chlorine bleach.

None of the art, insofar as is known, describe the use of nonionic polyether polyols which are capped with sterically hindered epoxides, in liquid detergent compositions containing chlorine bleach. It is an advance in the art to include nonionic surfactants into liquid detergent compositions containing chlorine bleach and retain adequate storage stability.

In accordance with the present invention, the applicants have discovered that capping nonionic copolymers of ethylene oxide and propylene oxide with sterically hindered epoxides provides enhanced stability of the polyether polyol in cleaning compositions which include alkaline hypochlorite bleaching agents, thereby allowing these formulations to retain their cleaning and defoaming properties for longer periods of time than formulations containing conventional nonionic polyether polyol surfactants.

Conventional nonionic polyether surfactants are disclosed which are capped with sterically hindered epoxides. The preferred surfactants before being capped, are those having an average molecular weight range of from about 500 to 25,000 and a relatively low hydrophilic content. The hydrophilic content of the surfactant is from about 5 to 40 weight percent. The polyether surfactants may be block or heteric copolymers of alkylene oxides, or they may contain blocks of heteric copolymers of alkylene oxides. Suitable polyethers may be mono- through octa-functional and are capped with sterically hindered epoxide groups to provide the nonionic polyether surfactants which exhibit excellent chlorine bleach stability.

These polyether surfactants may be produced in the manner conventional polyether polyols are produced and then capped with a sterically hindered epoxide at elevated temperatures over a prolonged period of time. The polyethers are then neutralized with an acid to produce the capped surfactants. Other forms of catalyst removal such as ion exchange or adsorbent treatment are also anticipated.

The products produced according to the present invention are a polyoxyalkylene polyethers capped at each reactive hydrogen with a sterically hindered epoxide, and have a general structure which is believed to be a mixture of compounds of the formula:

wherein A.sub.1 and A.sub.2 are C.sub.2 -C.sub.4 alkylene groups, tetramethylene, and mixtures thereof;

A.sub.3 is a C.sub.4 -C.sub.30 sterically hindered alkylene group, C.sub.4 -C.sub.30 sterically hindered arylalkylene group, and mixtures thereof;

n+n'=a number such that the total molecular weight of the uncapped portion of the molecule is about 500 to 25,000;

n" is a number from 1 to 8;

m is a number from 1 to 8; and

the hydrophilic content of the molecule is from about 5 to 40 weight percent and Y is the residue of an active-hydrogen containing compound. Those skilled in the art recognize that the term active hydrogen is defined by the Zerewitinoff test.

Novel nonionic polyether surfactants have been developed which exhibit surprising stability in the presence of chlorine bleach based upon capping the polyether surfactants with sterically hindered epoxides. In addition to their enhanced chlorine bleach stability, these surfactants are low foaming and detergent compositions containing these capped surfactants have improved spotting and filming properties comparable to powdered detergent formulations.

The surfactants are preferably polyoxyalkylene polyethers terminated with oxyethylene groups. These terminal groups are further capped with sterically hindered epoxides to provide the desired stability and other properties in cleaning compositions containing chlorine bleach. Generally, the terminal atom on the chains of such compounds is a hydrogen atom which is preceded by the polyoxyethylene group. However, for simplicity's sake, and is generally used in the art, the expression "terminated with the oxyethylene group," as used throughout the instant specification and claims, includes compounds having terminal hydrogen atoms.

A preferred type of oxyethylene group terminated polyoxyalkylene polyethers is a cogeneric mixture of conjugated polyoxyalkylene compounds containing in their structure, oxyethylene groups, oxypropylene groups and the residue of an active hydrogen containing compound. The term "cogeneric mixture" used herein is a term that has been coined to designate a series of closely related homologues that are obtained by condensing a plurality of alkylene oxide units with a reactive hydrogen compound. This expression is well known to those skilled in the art as can be seen from U.S. Pat. Nos. 2,677,700; 2,674,619; and 2,979,528.

The active hydrogen containing compound also referred to herein as an initiator has about 1 to 30 carbon atoms, preferably about 1 to 14 carbon atoms, and at least 1, preferably about 1 to 8, active hydrogen atoms. Typical initiators useful in the present invention include monofunctional or polyfunctional alcohols such as methanol, ethanol or higher branched or unbranched monofunctional alcohols, hexyl alcohol, octyl alcohol, decyl alcohol, stearyl alcohol, and mixtures thereof, phenol, alkyl phenols and dialkyl phenols, difunctional alcohols such as ethylene glycol, propylene glycol, butylene glycol, ethylenediamine, triethylenediamine, hexylmethylenediamine, trimethylol propane, pentaerythritol, sucrose and erythritol, C.sub.1 -C.sub.30 mono- or polyalkyl phenols, polyhydroxy alkylated phenols, hydrogenated (polyphenol) alkanes, polyphenols where the aromatic rings are fused or bridged by alkyl groups or are linked directly but not fused, such as diphenols, oxyalkylated alkyl amines, aniline or other aromatic amines or polyamines, fatty acids, fatty amides, oxyalkylated fatty acids, oxyalkylated fatty amides and mixtures thereof.

Broadly defined, the initiator may be a 1,2- or 1,X-difunctional alcohol where X is an integer not exceeding the number of carbon atoms in the alcohol, mono-alkyl ethers of the above-mentioned glycols, or other higher functional alcohols.

Other typical initiators may include amines, amides, mercaptans and carboxylic acids. Indeed, other surfactants may be useful as starting materials for the instant invention. These include oxyalkylated amines, oxyalkylated fatty acids and oxyalkylated fatty amines.

These initiator compounds may be heteric or block, as long as they are terminated with oxyethylene groups and are characterized in that the oxyalkylene groups are attached to the initiator compound at the site of the reactive hydrogen atoms.

In one preferred embodiment of this invention, the oxyalkylene compounds are those of the type disclosed in U.S. Pat. No. 2,674,619 prepared by first oxypropylating an initiator and subsequently oxyethylating the resulting compound as more completely described in the above-mentioned patent, incorporated herein by reference. In such compounds, the polyoxypropylene groups are attached to the initiator nucleus at the site of the reactive hydrogen atoms, thereby constituting a polyoxypropylene polymer. The oxyethylene chains are attached to the polyoxypropylene polymer in oxyethylene chains. The oxypropylene chains optionally, but advantageously, contain small amounts of ethylene oxide and the oxyethylene chains optionally but advantageously contain small amounts of other alkylene oxides such as propylene oxide and/or butylene oxide. Such compounds are believed to correspond to the formula:

Wherein Y is the residue of an organic compound having from about 1 to 30, preferably about 1 to 14 carbon atoms and containing x reactive hydrogen atoms in which x has a value of at least 1, preferably about 1 to 8, n has a value such that the molecular weight of the polyoxypropylene hydrophobic base is about 300 to 23,750 and m has a value such that the oxyethylene content of the molecule is from about 5 to 40, preferably 10 to 30 weight percent of the molecule.

It is further noted that when the molecular weight is stated in this specification or in the claims, unless otherwise noted, there is meant the average theoretical molecular weight which equals the total of the grams of the alkylene oxide employed per mole of reactive hydrogen compound. It is well recognized in the field of alkylene oxide chemistry that the polyoxyalkylene compositions one obtains by condensing an alkylene oxide with a reactive hydrogen compound are actually polymeric mixtures of compounds rather than a single molecular compound. The mixture contains closely related homologues wherein the statistical average number of oxyalkylene groups equals the number of moles of the alkylene oxide employed and the individual members in the mixtures contain varying numbers of oxyalkylene groups. Accordingly, as already noted, the oxypropylene chains optionally but advantageously may contain small amounts of ethylene oxide and the oxyethylene chains optionally but advantageously contain small amounts of alkylene oxides such as propylene oxide and butylene oxide. Thus, the compositions of this invention are mixtures of compounds which are defined by molecular weight of the polyoxypropylene chains and weight percent of oxyethylene groups.

Preferred compounds of the Formula I are those where Y is a residue of propylene glycol, or propylene glycol mono methylether whereby the formulae then become

wherein n has a value such that the molecular weight and the polyoxypropylene hydrophobic base is about 300 to 23,750, preferably 450 to 17,500, m has a value such that the oxyethylene content of the molecule is from about 5 to 40, preferably 10 to 30 weight percent of the molecule.

Nitrogen-containing polyoxyalkylene compositions are included in the present invention which are similar to those described in U.S. Pat. No. 2,979,528. These compounds are prepared in much the same manner as those disclosed in accordance with the procedure disclosed in U.S. Pat. No. 2,679,619. However, instead of propylene glycol or propylene glycol monomethyl ether as an initiator, a reactive hydrogen compound containing nitrogen is utilized. Initiators for these compounds include ammonia, primary amines, alkylene polyamines, alkanol amine and heterocyclic nitrogen compounds. Aliphatic primary diamines, having not over 8 carbon atoms are the preferred nitrogen-containing reactive hydrogen compounds and include ethylenediamine, diethylene triamine, triethylene tetramine tetraethylene pentamine, hexamethylene diamine, phenylene diamine and the like.

Useful nitrogen-containing nonionic surfactants are mixtures of cogeneric polyoxypropylene polyoxyethylene compounds based on a nitrogen-containing reactive hydrogen compound wherein chains of oxypropylene groups having a defined molecular weight are attached to the nucleus of the reactive hydrogen compound at the sites of the hydrogen atoms and wherein the chains of oxyethylene groups are attached to opposite ends of the oxypropylene chains. The compositions are prepared by condensing propylene oxide with a nitrogen-containing reactive hydrogen compound, preferably ethylenediamine and subsequently condensing ethylene oxide with the propylene oxide-reactive hydrogen compound. The collective molecular weight of the oxypropylene chains attached to the nitrogen-containing reactive hydrogen compound must be at least about 300 and can range up to about 23,750 or higher. Where ethylenediamine is the reactive hydrogen compound, these compounds are believed to have the following formula: ##STR2## wherein n has a value such that the overall molecular weight of the polyoxypropylene hydrophobic base is about 300 to 23,750, preferably about 450 to 17,500, and m has a value such that the polyoxyethylene hydrophilic base is from about 5 to 40, preferably about 10 to 30 weight percent of the molecule. Amine oxides of structure III are also anticipated to be of utility.

Other preferred polyether surfactants are those wherein Y in Formula I above is methanol.

The instant invention is also applicable to conventional oxypropylene group terminated polyoxyalkylene polyols. More specifically, polymers prepared by reacting all the hydroxyl groups of the oxyethylene group terminated polyols with propylene oxide. For example, the polyols to be capped with the oxypropylene groups prior to capping with the sterically hindered epoxides could be polyoxyethylene polyether polyols similar to those described above, but having oxypropylene terminal groups such as those disclosed, including preparation thereof, in U.S. Pat. No. 3,036,118; which is oxypropylene group terminated. When such compounds are capped with oxypropylene groups by conventional means, a product may be produced which also presents chlorine bleach stability problems, which may be met by capping the surfactant so formed with a sterically hindered bulky epoxide. Similarly, heteric polyoxyalkylene polyols such as polyols incorporating a heteric mixture of oxypropylene and oxyethylene groups when capped with oxypropylene rich groups by methods known to those skilled in the art present the same problems with regard to chlorine bleach stability. These problems are addressed by capping the surfactants with a sterically hindered epoxide, as will hereinafter be described.

Such polyoxyalkylene polyols capped with oxypropylene groups are believed to have the following generalized formula:

wherein A is an oxyalkylene hydrophilic group selected from oxyethylene, which may contain small amounts of oxypropylene, oxybutylene, oxytetramethylene, as a heteric block thereof; m and n are whole numbers selected to give an overall molecular weight of the product of about 500 to 25,000; Y is as set forth above and n represents a value whereby the total number of oxypropylene groups in the compound is about 5 to 410.

In a preferred embodiment, x is 1 to 8, A comprises oxyethylene groups centrally located in the molecule with oxypropylene groups attached at each end thereof. In another embodiment, A is a heteric mixture of oxypropylene or oxybutylene groups with the oxyethylene groups. The preferred compounds prior to capping with oxypropylene generally have the formula:

wherein Y is the residue of an organic compound having about 1 to 14 carbon atoms; x is the number of reactive hydrogen atoms and is from about 1 to 8; n has a value such that the molecular weight of all the polyoxypropylene in the conventional surfactant is from about 300 to 23,750 and m has a value such that the oxyethylene content of the molecule is from about 5 to 40, preferably 10 to 30 weight percent of the molecule. A preferred compound of this type prior to capping with oxypropylene is one wherein Y is ethylene glycol or propylene glycol whereby the formula is:

wherein m has the value set forth above for Formula V and n has a value such that the total molecular weight of the polyoxypropylene hydrophobic base is from about 300 to 23,750. These compounds are more particularly described in U.S. Pat. No. 3,036,118 incorporated herein by reference. In the products which are of the type more particularly described in U.S. Pat. No. 2,979,528, except that the propylene oxide and ethylene oxide groups are in reverse order, Y can also represent the reactive hydrogen compounds containing nitrogen and having up to about 6, inclusive, carbon atoms. A preferred compound of this type is one where Y is ethylenediamine and the formula is: ##STR3## wherein n has a value such that the molecular weight of all the polyoxypropylene hydrophobic groups is about 300 to 23,750 and m has a value such that the oxyethylene content of the molecule is from about 5 to 40, preferably 10 to 30 weight percent of the molecule. Heteric structure are also included and the formula is modified according as is well known to one skilled in the art. Amine oxides of such surfactants are anticipated as being of utility.

In another embodiment, Y in Formulas IV and V is trimethylolpropane. The polyols of Formulas V, VI, and VII are then capped with oxypropylene groups prior to their being capped with the sterically hindered epoxides, by methods well known to those skilled in the art whereby the total number of oxypropylene groups in the compound is from about 5 to 410.

The polyether surfactants described above are then capped with sterically hindered epoxide groups at the sites of the terminal hydrogen or hydroxyl groups. The sterically hindered epoxide groups are the residue of an alkylene oxide of the general formula: ##STR4## where R.sub.1, R.sub.2, R.sub.3 and R.sub.4 independently H, C.sub.1 -C.sub.30 alkyl, phenyl and alkylphenyl groups, and preferably at least two of R.sub.1 -R.sub.4 are not hydrogen, and most preferably R.sub.1 and R.sub.2 are not hydrogen.

Specific hindered epoxides which find particular use in the present invention may be selected from the group consisting of isobutylene oxide, (polyisobutylene) oxide, alpha-, beta- pinene oxide, styrene oxide, VIKOLOX.RTM. 24-28 epoxide, which is a registered trademark of Viking Chemical Company, 2-hexyl-1-decene oxide, and other long chain epoxides such as those characterized by the VIKOLOX.RTM. epoxides.

These sterically hindered epoxides are added to the polyether surfactants in the presence of alkylene oxide addition catalysts such as are well known to those skilled in the art. The resulting capped polyether surfactants have the formula

wherein A.sub.1 and A.sub.2 are C.sub.2 -C.sub.4 alkylene groups, tetramethylene, and mixtures thereof;

A.sub.3 is a sterically hindered C.sub.4 -C.sub.30 alkylene groups, C.sub.4 -C.sub.30 arylalkylene groups, and mixtures thereof;

n+n'=a value such that the totalmolecular weight of the uncapped portion of the molecule is about 500 to 25,000;

n" is a number from 1 to 8;

m is a number from 1 to 8, the hydrophilic content of the molecule is from about 5 to 40 weight percent and Y is an active hydrogen containing-compound.

The chlorine bleach stable surfactants of the present invention are most useful when formulated in cleaning products containing chlorine bleach such as products for home dishwashing, wearwashing, hard surface and metal cleaning or other uses. In such products, the chlorine bleach attacks conventional nonionic surfactants and reduces their spotting and defoaming properties. Such attack also reduces the chlorine bleach content of such products. By use of the present invention, nonionic surfactants may be incorporated into detergent compositions which allow for longer self life than products currently in use.

Useful cleaning compositions incorporating the chlorine bleach stable polyoxyalkylene polyols of the instant invention generally include additional components which make up the formulated detergent composition.

The manner of using these components by incorporating in a dishwashing, laundry, hard surface cleaner, or other detergent composition is well known to those skilled in the art. Such additional components include other surfactants, chlorine releasing agents, builders, and additives such as bleaches, abrasives, fillers, dyes, perfumes, soil anti-redeposition agents, corrosion inhibitors, silicates, alkalies, processing aids, hydrotropes, etc.

The preferred nonionic surfactants employed as additional components include the oxyethylene group terminated compounds of Formulas I, II, IIa, and III, set forth above. Other nonionics that may be employed include the polyoxyethylene-polyoxypropylene condensates of alkylphenols having from about 6 to 20 carbon atoms in the alkyl portion and from about 5 to 30 ethyleneoxy groups and/or propyleneoxy in the polyoxyalkylene radical, alkylene oxide adducts of higher aliphatic alcohols and thioalcohols having from about 8 to 22 carbon atoms in the aliphatic portion and about 3 to 50 oxyalkylene units in the oxyalkylene portion and which are preferably oxyethylene group terminated. Other well known nonionics may also be employed.

Important components of cleaning compositions particularly automatic dishwashing detergents are the builders or builder salts such as alkaline condensed phosphate salts, for instance, tetrasodium pyrophosphate and those polyphosphates of the calcium and magnesium ion sequestering type whose Na.sub.2 O/P.sub.2 O.sub.5 ratios range from 1:1 to 1 67:1 and 20 to 80 weight percent of an alkaline detergent salt such as sodium carbonate, sodium bicarbonate and mixtures thereof, di- and trisodium orthophosphate, sodium metasilicate, sodium sesquisilicate, borax and sodium borate, sodium hydroxide and potassium hydroxide.

Alternatively to the use of phosphate builders, any of the water-soluble metal salts of citric acid can be used in the practice of the present invention. However, all salts do not serve with equal effectiveness, and the alkali metal salts, particularly the sodium and potassium citrates, are preferred. Suitable proportions of silicates in dishwashing formulations are employed to overcome certain difficulties. The silicate used is preferably solid granular sodium metasilicate, a commercially available material. Sodium silicates in which the mole ratio of SiO.sub.2 :Na.sub.2 O are more than 1:1, e.g., 2:1 or 3:1, may be used in place of the sodium metasilicate.

The combination of the citrate and condensed phosphate salt (e.g., sodium tripolyphosphate) appears to result in an enhanced activity.

Active chlorine-containing compounds or chlorine-releasing compounds are often desirable in cleaning compositions. Such compounds which may be employed in accordance with the instant invention include chlorinated trisodium phosphate, trichlorocyanuric acid, sodium salt of dichlorocyanuric acid, potassium salt of dichlorocyanuric acid, sodium hypochlorite, potassium hypochlorite, and 1,3-dichloro-5,5-dimethylhydantoin.

Suitable hydrotropes that may be employed include sodium xylene sulfonate, sodium-2-ethyhexyl sulfates, amine alkaryl sulfonates, alkyl napthalene sulfonates, dodecyl benzene sulfonates and sodium dialkyl sulfosuccinates.

The term "additives" as defined herein and used throughout this specification and claims does not include other surfactants, builder salts and chlorine releasing compounds which are referred to separately.

Preferred cleaning compositions employing products of this invention will comprise from about 0.1 to 5 percent, preferably about 1 to 4 percent polyoxyalkylene polyether surfactant capped with a sterically hindered epoxide and about 95 to 99 percent, preferably about 96 to 99 percent of machine dishwashing components selected from the group consisting of other surfactants, builder salts, chlorine releasing agents, additives and mixtures thereof. A suitable cleaning composition may contain from about 0.1 to 5 percent, preferably about 1 to 4 percent of the polyoxyalkylene polyether surfactant capped with a sterically hindered epoxide, about 0.1 to 5 percent, conventional surfactants, about 0.1 to 5 percent, preferably about 0.9 to 1.5 percent available chlorine, about 25 to 80 percent, preferably about 35 to 60 percent builder salts, and about 0 to 60 percent, preferably about 5 to 40 percent additives, and the balance water. Since different chlorine releasing compounds have differing percentages of available chlorine, the amount is expressed herein as percent available chlorine.

When used for washing purposes such as in a dishwashing application, such solution may contain about 0.1 to 0.5, and preferably about 0.15 to 0.3 percent of the total detergent composition set forth above, balance water.

When used as a hard surface cleaner, or as a detergent, the composition may contain, in addition to the above, 1 to 65 percent alkaline source, solvents and other additives.

The following Examples are offered to illustrate various aspects of the invention. Those skilled in the art appreciate that many variations are possible, and the examples are not to be construed as limiting the scope and spirit of the invention.

In the Examples, the amount of available chlorine in the formulation was determined using conventional iodometric titration techniques, with adjustments to accommodate the bases used, as are well known to those skilled in the art.

The conventional surfactants syntheses are well known to those skilled in the art. Two general synthetic routes to the surfactants of the instant invention were followed, which are outlined below for two specific cases.

A 1-liter, stainless-steel Parr.RTM. autoclave was used, which ha stirring and heating capabilities, and was capable of a working pressure of 100 pounds per square inch gauge (psig). 603.3 g (0.33 moles) of the starting surfactant described in Example 1, Table I and 3.3 g (0.06 moles) of potassium- tert-butoxide were added. The reactor was sealed, and evacuated at 100.degree. C. for approximately one hour. 23.8 g (0.33 moles) of isobutylene oxide (IBO) were then introduced to the reactor utilizing the vacuum in the reactor. After all of the IBO was added, the reactor was heated to a maximum of 155.degree. C., total heating time 12.5 hours. At this time the pressure in the autoclave was constant over time with constant temperature. The material was then neutralized with phosphoric acid. The product had a hydroxyl content of 9.4 mg KOH equivalent per gram of sample. The product corresponds to example 2, on Table I.

In another method to produce the sterically hindered surfactants, a one-gallon, Autoclave Engineers, stainless steel autoclave capable of working pressures of 150 psig was used. It was charged with 2500 g (1.33 moles) of the starting surfactant described in Table I, Example 8, with the catalyst used in the production of the surfactant still present. No other catalyst was added. The reactor was sealed, and evacuated for one hour at 100.degree. C. The temperature was raised to 115.degree. C., and 193 g (2.68 moles) of isobutylene oxide (IBO) were added over a period of three hours and 45 minutes. Once all of the IBO was added, the mixture was allowed to react for 3 hours. The reaction was complete when the pressure in the autoclave was constant over time with constant temperature. The product was cooled and discharged, and subsequently neutralized with phosphoric acid. This product had a hydroxyl content of 5.5 milligrams KOH equivalent per gram of sample. The product corresponds to example 10, in Table I.

Table I depicts the chlorine stability of conventional surfactants versus various nonionic surfactants capped with sterically hindered epoxides in a formulation which is a blend of 1 weight percent surfactant, 1 weight percent NaOH and sufficient commercial sodium hypochlorite bleach solution (.about.15 percent available chlorine AvCl.sub.2) to give 2 percent available chlorine with the balance of the formula being distilled water. The formulation was placed in a 4 ounce French Square bottle equipped with a Teflon.RTM. fluorinated hydrocarbon coated stirring bar. The formula was stirred while blending. The formula samples were placed in an oven at 100.degree. F., and prior to being analyzed for available chlorine, were stirred. The available chlorine was determined using a conventional iodometric titration at 7 to 14 day intervals. The results are given in Table 1, Examples 1 through 13.

Table II depicts the chlorine stability of conventional surfactants versus various nonionic surfactants capped with sterically hindered epoxides. The surfactants were added at a 1 weight percent level to a liquid detergent composition containing a chlorine bleach. The detergent was comprised as follows:

The samples were placed in 8 ounce French Square bottles and stored in an oven at 100.degree. F. The remaining available chlorine in the samples was determined by wet analysis using standard iodometric titration techniques at 7 to 14 day intervals. The results are given in Table II.