CA1290639C - Liquid laundry detergent-bleach composition and method of use - Google Patents

Abstract

LIQUID LAUNDRY DETERGENT-BLEACH
COMPOSITION AND METHOD OF USE

ABSTRACT OF THE DISCLOSURE

In a liquid laundry detergent composition containing a perborate bleach, hydroxylamine sulfate is added as a bleach stabilizer and specifically as an inhibitor of catalase, an enzyme present in natural body soils, which enzyme will rapidly decompose hydrogen peroxide, the active bleaching component of the perborate bleach. The preferred composition are non-aqueous liquids based on liquid nonionic surfactants and preferably include a detergent builder salt suspended in the liquid nonionic surfactant.

Description

~0639 62301-1370 LIQUID LAUNDRY DETERGENT-BLEACH
COMPOSITION AE_D EIETEIOD OF USE
BACKGROUND OF THE INVENTION
(1) Field of Invention This invention relates to liquid laundry detergent compositions. More particularly, this invention relates to , non-aqueous liquid laundry detergent compositions which are easily pourable and which do not gel when added to water and to the use of these compositions for cleaning soiled fabrics.

(2) Discussion of Prior Art Liquid non-aqueous heavy duty laundry detergent compositions are well known in the art. For instance, compositions of that type may comprise a liquid nonionic surfactant in which are dispersed particles of a builder, as shown for instance in the U. S. Patents Nos. 4,316,812;

3,630,929; 4,264,466, and British Patents Nos. 1,205,711, 1,270,040 and 1,600,981.
Liquid detergents are often considered to be more convenient to employ than dry powdered or particulate products and, therefore, have found subs-tantial favor with consumers.
They are readily measurable, speedily dissolved in the wash water, capable of being easily applied in concentrated solutions or dispersions to soiled areas on garments to be laundered and are non-dusting, and they usually occupy less storage space.
Additionally, the liquid detergents may have incorporated in their formulations materials which could not stand drying operations without deterioration, which materials are often desirably employed in the manufacture of particulate detergent products. Although they are possessed o-E many advantages over unitary or particulate solid products, liquid detergents often have certain inherent disadvantages too, which have to be over-.~ - 1 - ~

~ 6~ 62301-1370 come to produce acceptable commercial detergent products. Thus, some such products separate out on storage and others separate out on cooling and are not readily redispersed. In some cases the product viscosity changes and it becomes either too thick to pour or so thin as to appear watery. Some clear products become cloudy and others gel on standing.
The present inventors have been extensively involved in studying the rheological behavior of nonionic liquid surfactant systems with and without particulate matter suspended therein. Of particular interest has been non-aqueous built laundry liquid detergent compositions and the problems of gelling associated with nonionic surfactants as well as settling of the suspended builder and other laundry additives. These considerations have an impact on, for example, product pour-ability, dispersibility and stability.
The rheological behavior of the non-aqueous built liquid laundry detergents can be analogized to the rheological behavior of paints in which the suspended huilder particles correspond to the inorganic pigment and the nonionic liquid surfactant corresponds to the non-aqueous paint vehicle. For simplicity, in the following discussion, the suspended particles~ e.g. detergent builder, will sometimes be referred to as the "pigment".
It is known that one of the major problems with paints and built liquid laundry detergents is their physical stability.

This problem stems from the fact that the density of the solid pigment particles is higher than the density of the liquid matrix.
Therefore, the particles tend to sediment according to Stoke's law. Two basic solutions exist to solve the sedimentation pro-blem: liquid matrix viscosity and reducing solid particle size.
For instance, it is known that such suspensions can be stabilized against settling by adding inorganic or organic thickening agents or dispersants, such as, for example, very high surface area inorganic materials, e.g. finely divided silica, clays, etc., organic thickeners, such as the cellulose ethers, acrylic and acrylamide polymers, polyelectrolytes, etc. However, such increases in suspension viscosity are naturally limited by the requirement that the liquid suspension be readily pourable and flowable, even at low temperature. Furthermore, these additives do not contribute to the cleaning performance of the formulation.
Grinding to reduce the particle size is more advan-tageous and provides two major consequences:
1. The pigment specific surface area is increased, and, therefore, particle wetting by the non-aqueous vehicle (liquid nonionic) is proportionately improved.
2. The average distance between pigment particles is reduced with a proportionate increase in particle-to-particle interaction. Each of these effects contributes to increase the rest-gel strength and the suspension yield stress while at the same time, g significantly reduces plastic viscosity.
The nonaqueous liquid suspensions of the detergent builder particles, such as the polyphosphate builders, especially sodium tripolyphosphate (TPP) in nonionic surfactant are found to behave, rheologically, substantially according to ~L~9~

the Casson equation:

a O ~ n ~

where y is the shear rate, ~ is the shear stress, aO is the yield stress (or yield value), and ~ is the "plastic viscosity" (apparent viscosity at infinite shear rate).
The yield stress is the minimum stress necessary to induce a plastic deformation (flow) of the suspension. Thus, visualiz-ing the suspension as a loose network of pigment particles, ifthe applied stress is lower than the yield stress, the suspension behaves like an elastic gel and no plastic flow will occur. Once the yield stress is overcome, the network breaks at some points and the sample begins to flow, but with a very high apparent viscosity. If the shear stress is much higher than the yield stress, the pigments are partially shear-deflocculate and the apparent viscosity decreases. Finally, i~ the shear stress is much higher than the yield stress value, the pigment particules are completely shear-deflocculated and the apparent viscosity is very low, as if no particle inter-action were present.
Therefore, the higher the yield stress of the suspension, the higher the apparent viscosity at low shear rate and the better is the physical stability of the product.
In addition to the problem of settling or phase separation the non-aqueous liquid laundry detergents based on liquid nonionic surfactants suffer from the drawback that the nonionics tend to gel when added to cold water. This is a particularly important problem in the ordinary use of European household automatic washing machines where the user places the laundry detergent composition in a dispensing unit (e.g. a ~ - 4 -~ 3~ 62301-1370 dispensing drawer) of the machine. During the operation of the machine the detergent in the dispenser is subjected to a stream of cold water to transfer it to the main body of wash solution.
Especially during the winter months when the detergent composi-tion and water fed to the dispenser are particularly cold, the detergent viscosity increases markedly and a gel forms. As a result some of the composition is not flushed completely off the dispenser during operation of the machine, and a deposit of the composition builds up with repeated wash cycles, eventually requiring the user to flush the dispenser with hot water.
The gelling phenomenon can also be a problem whenever it is desired to carry out washing using cold water as may be recommended for certain synthetic and delicate fabrics or fabrics which can shrink in warm or hot water.
Partial solutions to the gelling problem in aqueous, substantially builder-free compositions have been proposed and include, for example, diluting the liquid nonionic with certain viscosity controlling solvents and gel-inhibiting agents, such as lower alkanols, e.g. ethyl alcohol (see U. S. Patent No.
3,953,380), alkali metal formates and adipates (see U. S. Patent No. 4,368,147), hexylene glycol, polyethylene glycol, etc.
In addition, these two patents each disclose the use of up to at most about 2.5% of the lower alkyl (Cl-C4) etheric derivatives of the lower (C2-C3) polyols, e.g. ethylene glycol, in these aqueous liquid builder-free detergents in place of a portion of the lower alkanol, e.g. ethanol, as a viscosity control solvent. To similar effect are U. S. Patents Nos. 4,111,855 and 4,201,686. However, there is no disclosure or suggestion in any of these patents that these compounds, some of which are commercially available under the tradename Cellosolve ~ , could function effectively as viscosity control ~ - 5 -and gel-preventing agents for non-aqueous liquid nonionic surfactant compositions, especially such compositions containing suspended builder salts, such as the polyphosphate compounds, and especially particularly such compositions which do not depend on or require the lower alkanol solvents as viscosity control agents.
Furthermore, British Patent Specification 1,600,981 mentions that in non-aqueous nonionic detergent compositions containing builders suspended therein with the aid of certain dispersants for the builder, such as finely divided silica and/or polyether group containing compounds having molecular weights of at least 500, it may be advantageous to use mixtures of nonionic surfactants, one of which fulfills a surfactant function and the other of which both fulfills a surfactant function and reduces the pour point of the compositions. The former is exemplified by C12-C15 fatty alcohols with 5 to 15 moles of ethylene and/or propylene oxide per mole. The other surfactant is exemplified by linear C6-C8 or branched C8-C
fatty alcohols with 2 to 8 moles ethylene and/or propylene oxide per mole. Again, there is no teaching that these low carbon chain compounds could control the viscosity and prevent gelation of the heavy duty non-aqueous liquid nonionic surfactant compositions with builder suspended in the nonionic liquid surfactant.
It is also known to modify the structure of nonionic surfactants to optimize their resistance to gelling upon contact with water, particularly cold water. As an example of nonionic surfactant modification one particularly successful result has been achieved by acidifying the hydroxyl moiety X

.

end group of the nonionic molecule. The advantages of introducing a carboxylic acid at the end of the nonlonic lnclude gel inhibition upon dilution; decreasing the nonionlc pour polnt; and formation of an anionic surfactant when neutralized in the washing liquor. INonionic structure optimization for minimizing gelation is also known, for example, controlling the chain length of the hydrophobic-lipophllic moiety and the number and make-up of alkylene oxide (e.g. ethylene oxide) units of the hydrophlllic moiety. For example, it has been found that a C13 fatty alcohol ethoxylated with 8 moles of ethylene oxide presents only a limited tendency to gel formation.
Neverthele~s, still further improvements are desired in the stability, viscoslty control and gel inhibitlon of non-aqueous llquid detergent compositions.
This invention seeks to formulate highly built heavy duty non-aqueous liquid nonionic surfactant laundry detergent composltions whlch can be poured at all temperatures and which can be repeatedly dispersed from the dispensihg unit of European style automatic laundry washlng machines without fouling or plugging of the dispenser even during the winter months.
This invention further seeks to provlde non-gelling, ~table, low vi co~ity suspensions of heavy duty tripolyphosphate built non-aqueous liquid nonionic laundry detergent composition which include an amount of a low molecular weight amphiphilic compound sufficient to decrease the viscosity of the composition in the absence of water and upon contact with cold water.
The present invention provides a liquid laundry detergent-bleaching composition cornprising a liquld nonionic surfactant, a water soluble inorganic peroxide salt bleaching agent, an effective amount of a connpound which is an inhibitor of the enzyme-induced decomposition of the peroxide salt bleaching agent and a bleach activator which will react with the bleaching agent in an aqueous wash bath to form a peroxyacid bleaching agent at a temperature of about 40C or less. In some preferred embodiments one can also add to the liquid nonionic surfactant composition an amount of a low molecular weight amphiphilic compound, particularly, mono-, di-or tri(lower ~C2 to C3) alkylene)glycol mono(lower (C1 to C5) alkyl)ether, effective to inhibit gelation of the nonionic surfactant in the presence of cold water.
The present invention may additionally provide a liquid heavy duty laundry composition composed of a suspension of a builder salt in a liquid nonionic surfactant wherein the composition includes an amount of a lower (C2 to C3) alkylene glycol mono(lower) (C1 to C53 alkyl eth~r to decrease the viscosity of the composition in the absence of water and upon the contacting of the composition with water.
The present invention may further provide a non-aqueous liquid cleaning composition which remains pourable at temperatures below about 5C and which does not gel when contacted with or added to water at temperatures below about 20C, the composition being composed of a liquid nonionic ,2 i, ~ 8 .~.~

;3~

surfactant and C2 to C3 alkylene glycol mono(C1 to C5)alkyl ether and being substantially free of water.
The invention aclditionally provides a non-aqueous liquid detergent composition capable of washing and bleaching soiled fabrics at temperatures as low as about 40C or less which comprises a liquid nonionic surfactant, a mono or poly(C2 to C3)alkylene glycol mono~C1 to C5)alkyl ether, a water-soluble inorganic peroxide bleaching agent, a bleach activator to lower the temperature at which the bleaching agent will liberate hydrogen peroxide in aqueous solution, and from about 0.01 to 0.4 percent by weight, based on the total composition, of an hydroxylamine salt capable of inhibiting the enzyme-induced decomposition of the bleaching agent, said enzyme being present in the soiled fabrics.
The invention also provides a non-aqueous liquid detergent composition capable of washing and bleaching soiled fabrics at temperatures as low as about 40C. or less which comprises a liquid phase comprising nonionic surfactant and a mono or poly (C2 to C3) alkylene glycol mono (C1-C5) alkyl ether in an amount of 30 to 70%, a water-soluble inorganic peroxide bleaching agent in an effective amount of up to 25%, a bleach activator to lower the temperature at which the bleaching agent will liberate hydrogen peroxide in aqueous solution in an effective amount of up to 10%, proteolytic enzyme in an amount of from about 0.7 to 2 percent by weight and from about 0 01 to 0.4 percent by weight, based on the total composition, of an hydroxylamine salt capable of inhibiting the enzyme-induced decomposition of the bleaching agent, said enzyme being present in the soiled fabrics.

8a ~ 6~9 62301~~.370 The invention further provides a non-aqueous liquid laundry detergent-bleaching composition comprising a liquid phase comprising liquid nonionic surfactant, a detergent builder salt suspended in the liquid phase, an effective amount of a water soluble inorganic peroxide salt bleaching agent selected from the group consisting of perborate, percarbonate, perphosphate and persulfate, an effective amount of a bleach activator compound which will react with the bleaching agent in an aqueous wash bath to form a peroxy bleach agent at a temperature of about 40C. or less, an effective amoun~ of a proteolytic enzyme, and an effective amount in the range of from about 0.01 to about 0.4% by weight of the composition of an hydroxylamine salt to inhibit enzyme-induced decomposition of the peroxide salt bleaching agent.
The invention further provides a non-agueous liquid laundry detergent composition consisting essentially of about 40 to 60~ by weight of a liquid nonionic surfactant and a viscosity-controlling and gel-inhibiting compound of the formula R' RO~CHCH20)nH
where R is alkyl of 2 to 5 carbon atoms, R' is hydrogen or methyl, and n is a number from 2 to 4 on average, wherein the weight ratio of nonionic surfactant to said viscosity-controlling and gel-inhibi~ing compound being from 50:1 to 2:1, about 20 to 50~ by weight of detergent builder salt suspended in the liquid phase, about 2 to 20~ by weight of an alkali metal perborate bleaching agent 8b `, about 0.1-3~ by weight of te~raacetylene diamine bleach activator, about 0.7 to 2% by weight of proteolytic enzyme, and about 0.01 to 0.4% by weight of hydroxylamine salt capable of inhibiting the enzyme induced decomposition of the bleaching agent.
The invention may also provide a method for dispensing a liquid nonionic laundry detergent composition into and~or wi~h cold water without undergoing 8c ~ 3~39 62301-1370 gelation. In particular, a method is provided for filling a container with a non-aqueous liquid laundry detergent composi tion in which the detergent is composed, at least predominantly, of a liquid nonionic surface active agent and for dispensing the composition from the container into an aqueous wash bath, wherein the dispensing is effected by directing a stream of unheated water onto the composition such that the composition is carried by the stream of water into the wash bath. By including a low molecular weight amphiphilic compound, i.e.
a lower C2 to C3 alkylene glycol mono(lower)(Cl to C5)alkyl ether, the composition can be easily poured into the container even when the composition is at a temperature below room temperature. Furthermore, the composition does not undergo gelation when it is contacted by the stream of water and it readily disperses upon entry into the wash bath.
As will be seen below the liquid detergent composi-tions often include, in addition to the detergent active ingredient, one or more detergent additives or adjuvants. One of the more important of these, in terms of consumer appeal and actual cleaning benefit, is the class of bleach agents, especially the oxygen bleaches, of which sodium perborate monohydrate is a particularly preferred example. It is well known in the art that in solution, the persalt oxygen bleach releases hydrogen peroxide as the active oxidizing agent.
However, hydrogen peroxide is readily decomposed by catalase, an enzyme always present in natural soils and stains. This decomposition occurs even in the presence of bleach activators, as the rate of reaction between hydrogen peroxide and the activator is slower than the decomposition of hydrogen peroxide by catalase. The activity of catalase is very high, even at room temperature, and a substantial quantity of active oxygen is lost before catalase can be deactivated by increasing the _ g _ _ 62301-1370 temperature of the washing bath.
One approach to solving this problem has been to use an excessive amount of perborate or other peroxide bleaching agent, e.g. an amount generally 2 to 4 or more times that which would be required to effectively bleach the soil or stain in the absence of peroxide decomposing enzyme and also 2 to 4 or more times molar excess relative to the number of moles oE
bleach activator.
It has also been proposed to carry out the bleaching with an aqueous solution of peroxide bleaching agent in the presence of a compound capable of inhibiting enzyme-induced decomposition of the bleaching agent. Thus, U. S. Patent 3,606,990 to Gobert and Mouret and assigned to Colgate-Palmolive Company discloses a relatively wide range of inhibitor compounds, including, for example, hydroxylamine salt, hydrazine and phenylhydrazine and their salts, substituted phenols and polyphenols, and others, as well as various detergent composi-tions incorporating the water soluble inorganic peroxide bleaching agent and the inhibitor compound. However, there is no teaching of liquid detergent compositions which incorporate the inhibitor compounds nor is there a teaching that the inhibitor compounds would be effective in compositions contain-ing a bleach activator in addition to the peroxide bleach.
Furthermore, this patent states in column 7, lines 25-29 that in the case of hydroxylamine sulfate the effective amount of inhibitor compound is from about 0.5 to about 2 percent by weight of total composition.
It has now been discovered that in the detergent liquid compositions of this invention containing a water soluble inorganic peroxide bleaching agent of the persalt type the incorporation of very limited amounts of less than about 0.5%, _ ~rr~ 9 62301-1370 for example, 0.01 to about 0.45~, can effectively inhibit anzyme-induced decomposition of the bleaching agent. It has been further discovered that hydroxylamine sulfate is highly stable in the composition and does not at all interfere with activation of the bleaching system by conventional persalt bleach activators.
Therefore, in accordance with a still further aspect of the present invention there is provided a liquid heavy duty laundry detergent composition which includes a water soluble inorganic peroxide bleaching agent and an effective amount of a compound which ean inhibit enzyme-induced decomposition of the bleaching agent, especially in an amount of less than about 0.5% by weight of the composition, and preferably with an activator for activating the bleaching agent.
Other features and specific embodiments of the invention will be apparent and the in~-ention may be more readily -understood from the following detailed description.
The nonionic synthetic organic detergents employed in the practice of the invention may be any of a wide variety of such compounds, which are well known and, for example, are described at length in the text Surfaee Active Agents, Vol. II, by Sehwartz, Perry and Bereh, published in 1958 by Interscience Publishers, and in McCutcheon's Detergents and Emulsifiers, 1969 Annual. Usually,the nonionic detergents are poly-lower alkoxylated lipophiles wherein the desired hydrophile-lipophile balance is obtained from addition of a hydrophilie poly-lower alkoxy group to a lipophilie moiety. A preferred class of the nonionie detergent employed is the poly-lower alkoxylated higher alkanol wherein the alkanol is of 10 to 18 earbon atoms and wherein the number of mols of lower alkylene oxide (of 2 or 3 carbon atoms) is from 3 to 12. of such materials it is preferred to emp:Loy those wherein the higher alkanol is a higher ~. ' ~ 9 62301-1370 fatty alcohol of 10 to 11 or 12 to 15 carbon atoms and which contain from 5 to 8 or 5 to 9 lower alkoxy groups per mol.
Preferably, the lower alkoxy is ethoxy but in some instances, it may be desirably mixed with propoxy, the latter, if present, usually, but not necessarily, being a minor (less than 50%) proportion. Exemplary of such compounds are those wherein the alkanol is of 12 to 15 carbon atoms and which contain about 7 ethylene oxide groups per mol, e.g. Neodol 25-7 and Neodol 23-6.5, which products are made by Shell Chemical Company, Inc.
The former is a condensation product of a mixture of higher fatty alcohols averaging about 12 to 15 carbon atoms, with about 7 moles of ethylene oxide and the latter is a corresponding mixture wherein the carbon atom content of the higher fatty alcohol is 12 to 13 and the number of èthylene oxide groups present averages about 6.5. The higher alcohols are primary alkanols. Other examples of such detergents include Tergitol 15-S-7 and Tergitol 15-S-9, both of which are linear secondary alcohol ethoxylates made by Union Carbide Corp. The former is mixed ethoxylation product of 11 to 15 carbon atoms linear secondary alkanol with seven mols of ethylene oxide and the latter is a similar product but with nine mols of ethylene oxide being reacted.
Also useful in the present compositions as a component of the nonionic detergent are higher molecular weight nonionics, such as Neodol 45-11, which are similar ethylene oxide condensa-tion products of higher fatty alcohols, with the higher fatty alcohol being of 14 to 15 carbon atoms and the number of ethylene oxide groups per mol being about 11. Such products are also made by Shell Chemical Company. Other useful nonionics are represented by the well-known commercially available Plurafac Trade-mark ~ 62301-1370 series which are the reaction product of a higher linear alcohol and a mixture of ethylene and propylene oxides, containing a mixed chain of ethylene oxide and propylene oxide, terminated by a hydroxyl group. Examples include Plurafac R~30 (a C13-C15 fatty alcohol condensed with 6 moles ethylene oxide and 3 moles propylene oxide), Plurafac RA40 (a C13-C15 fatty alcohol condensed with 7 moles propylene oxide and 4 moles ethylene oxide), Plurafac D25 (a C13-C15 fatty alcohol condensed with 5 moles propylene oxide and 10 moles ethylene oxide), and Plurafac B26.
Generally, the mixed ethylene oxide-propylene oxide fatty alcohol condensation products can be represented by the yeneral formula RO(C2H4O)x(C3H6O) H, where R is straight or branched primary or secondary aliphatic hydrocarbon, preferably alkyl or alkenyl, of from 6 to 20, preferably 10 to 18, especially preferably 14 to 18 carbon atoms, x is a number of from 2 to 12, preferably 4 to 10, and y is a number of from 2 to 7, preferably 3 to 6.
Another group of liquid nonionics are available from Shell Chemical Company, Inc. under the Dobanol trade-mark:
Dobanol 91-5 is an ethoxylated Cg-Cll fatty alcohol with an average of 5 moles ethylene oxide; Dobanol 25-7 is an ethoxylated C12-C15 fatty alcohol with an average of 7 moles ethylene oxide; etc.
In the preferred poly-lower alkoxylated higher alkanols, to obtain the best balance of hydrophilic and lipophilic moieties the number of lower alkoxies will usually be from 40% to 100% of the number of carbon atoms in the higher alcohol, preferably 40 to 60% thereof and the nonionic detergent will preferably contain at least 50% of such preferred poly-Trade-mark ~ ~9~3639 lower alkoxy higher alkanol. Higher molecular weight alkanols and various other normally solid nonionic detergents and surface active agents may be contributory to gelation of - 13a -. . .

the liquid detergent and consequently, will preferably be omitted or limited in quantity in the present compositions, although minor proportions thereof may be employed for their cleaning properties, etc. With respect to both preferred and less preferred nonionic detergents the alkyl groups present therein are generally linear although branching may be tolerated, such as at a carbon next to or two carbons removed from the terminal carbon of the straight chain and away from the ethoxy chain, if such branched alkyl is not more than three carbons .
in length. Normally, the proportion of carbon atoms in such a branched configuration will be minor rarely exceeding 20%
of the total carbon atom content of the alkyl. Similarly~
although linear alkyls which are terminally joined to the ethylene oxide chains are highly preferred and are considered to result in the best combination of detergency, biodegradability and non-gelling characteristics, medial or secondary joinder to the ethylene oxide in the chain may occur. It is usually in only a minor proportion of such alkyls, generally less than 20% but, as is in the cases of the mentioned Terigtols, may be greater. Also, when propylene oxide is present in the lower alkylene oxide chain, it will usually, but not necessarily, be less than 20/, thereof and preferably less than 10/~ thereof.
l~hen greater proportions of non-terminally alkoxylated alkanols, propylene oxide-containing poly-lower alkoxylated alkanols and less hydrophile-lipophile balanced nonionic detergent than mentioned above are employed and when other nonionic detergents are used instead of the preferred nonionics recited herein, the product resulting may not have as good detergency, stability, viscosity and non-gelling properties as the preferred compositions but use of the viscosity and - ' ~y3~

gel controlling compounds of the invention can also improve the properties of the detergents based on such nonionics.
In some cases, as when a higher molecular weight polylower alkoxylated higher alkanol is employed, often for its detergency, the proportion thereof will be regulated or limited as in accordance with the results of various experiments, to obtain the desired detergency and still have the product non-gelling and of desired viscosity. Also, it has been found that it is only rarely necessary to utilize the higher molecular weight nonionics for their detergent properties since the preferred nonionics described herein are excellent detergents and additionally, permit the at~ainment of the desired viscosity in the liquid detergent without gelation at low temperatures.
Mixtures of two or more of these liquid nonionics can also be used and in some cases advantages can be obtained by the use of such mixtures.
As mentioned above, the structure of the liquid nonionic surfactant may be optimized with regard to their carbon chain length and configuration (e.g. linear versus branched chains, etc.) and their content a~d distribution of alkylene oxide units. Extensive research has shown that these structural characteristics can and do have a profound effect on such properties of the nonionic as pour point, cloud point, viscosity, gelling tendency, as well, of course, as on detergency.
Typically most commercially available nonionics have a relatively large distribution of ethylene oxide (EO) and propylene oxide (PO) units and of the lipophilic hydrocarbon chain length, the reported EO and PO contents and hydrocarbon chain lengths being overall averages. This "polydispersity"
of the hydrophilic chains and lipophilic chains can have great importance on the product properties as can the specific values of the average values. The relationship between "poly-~ ~ 63~

dispersity" and specific chain lengths with product propertiesfor a well-defined nonionic can be shown by the following data for the "Surfactant T" series of nonionics available from British Petroleum. The Surfactant T nonionics are obtained by ethoxylation of secondary C13 fatty alcohols having a na-row E0 distribution and have the following physical char-acteristics:

Cloud Point (1% sol) E0 Content Pour Point (C) (C) Surfactant T5 5 <-2 <25 Surfactant T7 7 -2 38 .
Surfactant T9 9 6 58 Surfactan; Tl2 12 20 88 To assess the impact of E0 distribution, a "Surfactant T8" was artificially prepared in two ways:
a. l:l mixture of T7 and T9 (T8a) b. 4 3 mixture of T5 and Tl2 (T8b) The following properties were found:

E0 Content Pour Point Cloud Point (1% sol'n~
(av~) (C) (C) l Surfactant T8a 8 2 48 i Surfactant T8b 8 15 <20 ¦ From these results, the following general obser~ations ¦ can be made:
¦ l. T8a corresponds closely to an actual surfactant ¦ T8 as it interpolates well between T7 and T9 for both pour ¦ point and cloud point.
¦ 2. 1`8b which is highly polydisperse and would be ¦ generally unsatisfactory in view of its high pour point and low cloud point temperatures.

~ 9 3. The properties of T8a are basically additive between T7 and T9 whereas for T8b the pour point is close to the long E0 chain (T12) while the cloud point is close;
to the short EO chain (T5).
The viscosities of the Surfactant T nonionics were measured at 20%, 30~/O, 40%, 50~/O, 60%, 80~/o and 100% nonionic concentrations for T5, T7, T7/T9 (1:1), T9 and T12 at 25C
with the following results (when a gel is obtained, the viscosity is the apparent viscosity) at lOO~sec:

Nonionic Viscosity (mPa-s) T5 ¦ T7 ¦ T7/T9 T9 T12 100 ~ ~36 63 61 149 _. . . =~ =. ~ , _ ~ _ __ From these results, it may be concluded that ~urfactant T7 is less gel-sensitive than T5, and T9 is less gel-sensitive than T12; moreover, the mixture of T7 and T9 (T8) does not gel, and its viscosity does not exceed 225 m Pa s. T5 and T12 do not form the same gel structure.
Although not wishing to be bound by any particular theory, it is presumed that these results may be accounted for by the following hypothesis:
For T5: with only 5 E0, the hydrodynamic volume of the E0 chain is almost the same as the hydrodynamic volume of the fatty chain. Surfactant molecules can accordingly arrange themselves to form a lamellar structure.

For T12: with 12 E0, the hydrodynamic volume of the eo chain is greater than that of the fatty chain. When molecules try to arrange themselves together, an interface curvature occurs and rods are obtained. The superstructure is then hexagonal; with a longer EO chain, or with a higher ~;~9~9 . .

hydratation, the interface curvature can be such that actual spheres are obtained, and the arrangement of the lowest energy is a face-centered cubic latice.
From T5 to T7 (and T8), the interface curvat~re increases, and the energy of the lamellar structure increases.
As the lamellar structure loses stability, its melting temperatur~
is reduced.
From Tl2 to T9 (and T8), the interface curvature decreases, and the energy of the hexagonal structure increases (rods become bigger and bigger). As the loss in stability occurs, the structure melting temperature is also reduced.
Surfactant T8 appears to be at the critical point at which the lamellar structure is destabilized, i.e. the hexagonal structure is not yet stable enough and no gel is obtained during dilution. In fact, a 50% solution of T8 will finally gel after two days, but the superstructure formation is delayed long enough to allow easy water dispersability.
The effects of the molecular weight on physical properties of the nonionics were also considered. Surfactant T8 (l:l mixture of T7 and T9) exhibits a ~ood compromise between the lipophilic chain (Cl3) and the hydrophilic chain (E08), although the pour point and maximum viscosity on dilution at 25C are still high.
The equivalent E0 compromise for ClO and C8 lipophilic chains was also determined using the Dobanol 91-x serie~
from Shell Chemical Co., which are ethoxylated derivatives of C9-Cll fatty alcohols (average: ClO); and Alfonic 610-y series from Conoco which are ethoxylated derivatives of C6-Clo fatty alcohols (avera~e Cg); x and y represent the E0 weight percenta~e.
The next table reports ~he physical characteristics ~ ~91)639 -of the Alfonic 610-y and Dobanol 91-x series:

Nonionic # E0 Pour Point Cloud Pt. Max.n on dilution (av~.) (C) (C)at 25C (~Pa-s) Alfonic 610-50R 3 -15 Gel (60%) Alfonic 610-60 4.4 -4 41 36 (60%) Dobanol 91-5 5 -3 33 Gel (70%) Dobanol 91-5T 6 +2 55 126 (50%) Dobanol 91-8 8 ~6 81 Gel (50%) Dobanol 91-5 and Dobanol 91-8 are commercially available products; Dobanol 91-5 topped (T) is a lab scale product:
it is Dobanol 91-5 from which free alcohol has been removed.
As the lowest ethoxylation ~embers are also removed, the average E0 number is 6. Dobanol 91-5T provides the ~est results of C10 lipophile chain as it does not gel at 25C.
The 1/~ cloud point (55C) is higher than for surfact~nt T8 (48C). This is presumably due to the lower molecular weight since the mixture entropy is higher. Alfonic 610-60 provides the best results of the C8 lipophile chain series.
A summary of the best E0 contents for each tested lipophilic chain length is provided in the following table:

Cloud Pt.
Nonionic # C # E0 Pour Pt. (1% soln) Max ~ on dil.~%) (C) (C) at 25C ~mPa s) Surfactant T8 13 8 +2 48 223 (50%) Dobanol 91-5T 10 6 +2 55 126 (50%) Alfonic 610-60 8 4.4 -4 41 36 (60%) From this data, the following conclusions were reached:
Pour points: as the nonionic molecular weight decreases, its pour points decrease too. The relatively high pour point of Dobanol 91-5T can be accounted for by the higher polydispersity .
This waS ~lso noticed Eor T8a and T8b, i.e. the chain polydispersi Y
increases the pour point.

~ 39 Cloud points: theoretically, as the number of molecules increases (if the rnolecular weight decreases), the mixing entropy is higher, so the cloud point would increase as the molecular weight decreases. It is actually the case ~rom Surfactant T8 to Dobanol 91-5T but it has not been confirmed with Alfonic 610-60. Here it is presumed that the lipophilic hydrocarbon chain polydispersity is responsible for the theoretica 11 too low cloud point. The relatively large amount of C10-E0 present reduces the solubility.
Maximum viscosity on dilution at 25C: none of these nonionics gel at 25C when they are diluted with water. ( The maximum viscosity decreases sharply with the molecular weight. As the nonionic molecular weight decreases, the less efficient becomes the hydrogen bridges. Unfortunately, too low molecular weight nonionics are not suitable for laundry washing: their micellar critical concentration (MCC~ is too high, and a true solution, with only a limited detergency would be obtained under practical laundry conditions.
With this information, the present inventors continued their studies on the effects of the low molecular weight amphiphilic compounds on the rheological properties of liquid nonionic detergent cleaning compositions. These studies revealed that while it is possible to lower the pour point of the composition and obtain some degree of gel inhibition by using a short chain hydrocarbon, e.g. about Cg, with a short chain ethylene oxide substitution, e.g. about 4 moles, as am?hiphilic additive, such as Alfonic 610-60, these additives do not significantly contribute to the overall laundry cleaning performance and still do not exhibit overall satisfactory viscosity control over all norrnal usage conditions.

- 1290~39 - I

I The present invention is, therefore, based, at least ¦in part, on the discovery that the low molecular weight amphiphili c ¦compounds which can be considered to be analogous in chemical ¦ structure to the ethoxylated and/or propoxylated fatty alcohol ¦nonionic surfactants but which have short hydrocarbon chain ¦lengths (Cl-C5) and a low content of alkylene oxide, i.e.
¦ ethylene oxide and/or propylene oxide (about 1 to 4 EO/PO
units per molecule) function e~fectively as viscosity control and gel-inhibiting agents for the liquid nonionic surface active cleaning agents.
The viscosity-controlling and gel-inhibiting amphiphilic compounds used in the present invention can be represented by the following general formula R' RO(CHCH20)nH
where R is a Cl-Cs, preferably C2 to Cs, especially preferably C2 to C4, and particularly C4 alkyl group, R' is H or CH3, preferably H, and n is a number of from about 1 to 4, preferably 2 to 4 on average.
Preferred examples of suitable amphiphilic compounds include ethylene glycol monoethyl ether (C2Hs-O-CH2CH20H), and diethylene glycol monobutyl ether (C4Hg-O-(CH2CH20)2H). Diethylene glycol monoethyl ether is especially preferred and, as will be shown below, is uniquely effective to control viscosity.
~'hile the amphiphilic compound, particularly diethylene glycol monobutyl ether, can be the only viscosity control and gel inhibiting additive in the invention compositions further improvements in the rheological properties of the anhydrous liquid nonionic surfactant compositions can be obtained by including in the composition a small amount of a nonionic surfactant which has been modified to convert ~ ~ 9 ~2~ ~lg1370 a ~ree hydroxyl group thereof to a moiety having a free carboxyl grou~ such as a ~artial c.stcr O~r a nonionic surfactant and a polycarboxylic acicl and/or an acidic organic phosphorus compound having an acidic - PO~I group, such as a partial ester of phos-phorous acid and an alkanol.
~ s disclosed in our Canadian Patent application Serial No. ~78,379, filed April 9, 1985, the free carboxyl group modi-ficd nonionic surfactants, which may he broadly characterizcd as ~olycther carboxylic acids, function to lower ~he temperature at whicll the liquid nonionic forms a gel with water. The acidic polyether compound can also decrease the yield stress oi such dispcrsions, aiding in their dispensibility, without a corres-ponding decrease in their stability against settling. Suitable polycther carboxylic acids contain a grouping of the formula ~OCH ~CH2~p~CH~C~l2~q~Y~Z~COOH where R is hydrogen or methyl, R2 Cll3 Y is oxygen or sulfur, Z is an organic linkage, p is a positive nul~er of from about 3 to about 50 and q is zero or a positive number of up to 10. Specifie examples include the half-ester of Plurafac R~30 with succinic anhydride, the half ester of Dobanol 25-7 with succinic anhydride, the half ester of Dobanol 91-5 with succinic anhydride, etc. Instead o~ a succinic acid anhydride, other polycarboxylic acids or anhydrides may be used, e.g. maleic acid, maleic anhydride, glutaric acid, malonic acid, succinic acid, phthalic acid, phthalic anhydride, citric acid, etc. rurthermore, other linkages may be uscd, such as ethcr, thiocthcr or urcthane linkages, formed by conventional rcactions.
ror instancc, to form an ether linkage, the nonionic surfactant may be treated with a strong base ~to convert its O~ group to an ONa ~roul~ for in.stancc) and thcn rcactcd with a halocarboxylic acid such as chloroacetic acid or chloxopro-pionic acid or the corresponding bromo compound. Thus, the resulting carboxylic acid may have the formula R-~-ZCOOH where R is the residue of a nonionlc surfactant (on removal of a terminal OH), Y is oxygen or sulfur and Z represents an organic linkage such as a hydrocarbon group of, say, one to ten carbon atoms which may be attached to the oxygen (or sulfur) of the formula directly or by means of an intervening linkage such as an oxygen-containing linkage, e.g. a O
or O , etc.
-C-NH-The polyether carboxylic acid may be produced from a polyether which is not a nonionic surfactant, e.g. it may be made by reaction with a polyalkoxy compound such as polyethylene glycol or a monoester or monoether thereof which does not have the long alkyl chain characteristic of the nonionic surfactants. Thus, R may have the formula R2 R (OCH-CH2)n~
where R2 is hydrogen or methyl, R1 is alkylphenyl or alkyl or other chain terminating group and "n" is at least 3 such as 5 to 25. When the alkyl of R1 is a higher alkyl, R is a residue of a nonionic surfactant. As indicated above R1 may lnstead be hydrogen or lower alkyl (e.g. methyl, ethyl, propyl, butyl) or lower acyl le.g. acetyl, etc.). The acidic polyether compound if present in the detergent composition, is preferably added dissolved in the nonionic surfactant.
The carboxylic acid used may also be a polyalkoxy carboxylate or N-acyl sarcoslnate a~ descrlbed and listed in ~irk-Othmer, "~ncyclopedia of Chemical Technology", 3rd Edition, Vol. 22 (1983), pages 348-349.

~ 23 -~9~6~9 Another useful class of supplemental anti-yelling agent are the C6 to C14 alkyl or alkenyl dlcarboxylic anhydride, such as, for example, octenylsuccinic anhydride, octenylmaleic anhydride, dodecylsuccinic anhydride, etc. These compounds may be used together with or in place of part or all of the polyether carboxylic acid an~tl-gelling agents.

- 23~-~L~9q~63~ 62301-1370 As disclosed ln our Canadian Patent Application Serial No. 478,380, filed April 4, 1985, the acidic organic phosphorus compound having an acidic - POH group can increase the stabillty of the suspension of builderr especia`lly polyphosphate builders, in the non-aqueous li~uid nonionic surfactant.
The acidic organic phosphorus compound may be, for instance, a partial ester of phosphoric acid and an alcohol such as an alkanol which has a lipophilic character, having, for instance, more than 5 carbon atoms, e.g. 8 to 20 carbon atoms.
A specific example is a partial ester of phosphoric acid and a C16 to C18 alkanol (Empiphos* 5632 from Marchon); it is made up of about 35~ monoester and 65% diester.
The inclusion of quite small amounts, for example, from about 0.05 to 0.3~ by weight of the composition, of the acidic organic phosphorus compound makes the suspension significantly more stable against settling on standing but remains pourable, presumably, as a result of increasing the yield value of the suspension, but decreases its plastic viscosity. It is believed that the use of the acidic phosphorus compound may result in the formation of a high energy physical bond between the -POH portion of the molecule and the surfaces of the inorganic polyphosphate builder so that these surfaces take on an organic character and become more compatible with ~he nonionic surfactant.
The acidic organic phosphorous compound may be selected from a wide variety of materials, in addition to the *Trade-mark 24 ~. .

partial esters of phosphoric acid and alkanols mentioned above.
Thus, one may employ a partial ester of phosphoric or phosphorous acid with a mono or po].yhydric alcohol such as hexylene glycol, ethylene glycol, cli- or tri ethylene glycol or higher polyethylene ~ 24a glycol, polypropylene glycol, glycerol, sorbitol, mono or diglycerides of fatty aclds, etc. ln whlch one, two or more of the alcohollc OH groups of the molecule may be esterlfled with the phosphorus acld. The alcohol may be a nonlonic surfactant such as an ethoxylated or ethoxylateclpropoxylated higher alkanol, higher alkyl phenol, or hlgher alkyl amide. The -POH
group need not be bonded to the organlc portion of the molecule through an ester llnkage; instead lt may be directly bonded to carbon ~as in a phosphonic acid, such as a polystyrene in which some of the aromatic rlngs carry phosphonlc acld or phosphlnic acid groups; or an alkylphosphonlc acld, such as propyl or laurylphosphonic acld) or may be connected to the carbon through other intervening llnkage (such as linkages through 0, S or N atoms). Preferably, the carbon-phosphorus atomic ratio ln the organic phosphorus compound i5 at least about 3~1, such as 5.1, 10.1, 20~1, 30~1 or 40~1. Among sulta~le compounds are the phosphate ester surfactants described and listed in Kirk-Othmer Encyclopedia of Chemical Technology", 3rd Edition, Vol.
22 (1983), pages 359-361.
The invention detergent composition may also and preferably does lnclude water soluble detergent builder salts.
Typical suitable builders lnclude, for example, those disclosed in U.S. Patents 4,316,812, 4,264,466, and 3,630,929. Water-soluble inorganic alkaline builder salts which can be used alone with the detergent compound or in admixture with other builders are alkali metal carbonate, borates, phosphates, polyphosphates, bicarbonates, and silicates. (Ammonium or substituted am~onium salts can also be used.) Speclfic ~G

~ 9 62301-1370 examples of such salts are sodium tripolyphosphate, sodium carbonate, sodium tetraborate, sodium pyrophosphate, potassium pyrophosphate, sodium bicarbonate, potassium tripolyphosphate, sodium hexametaphosphate, sodium sesquicarbonate, sodium mono and diorthophosphate, and potassium bicarbonate. Sodium tripolyphosphate (TPP) is especially - 25a-L~

~ 9 62301-1370 preferred. The alkali metal silicates are useful builder salts which also function to make the composition anticorrosive to washing machine parts. Sodium silicates of Na2O/SiO2 ratios of from 1.6/1 to 1/3.2 especially about 1/2 to 1/2.8 are preferred. Potassium silicates of the same ratios can also be used.
Another class of builders useful herein are the water-insoluble aluminosilicates, both of the crystalline and amorphous type. Various crystalline zeolites (i.e. alumino-silicate~are described in British Patent 1,504,168, U. S. Patent 4,409,136 and Canadian Patents 1,072,835 and 1,087,477. An example of amorphous zeolites useful herein can be found in Belgium Patent 835,351. The zeolites generally have the formula ( 2 )x tA12O3)y~(SiO2)z-WH2O
wherein x is 1, y is from 0.8 to 1.2 and preferably 1, z is from 1.5 to 3.5 or higher and preferably 2 to 3 and W is from 0 to 9, preferably 2.5 to 6 and M is preferably sodium. A typical zeolite is type A or similar structure, with type 4A
particularly preferred. The preferred aluminosilicates have calcium ion exchange capacities of about 200 milliequivalents per gram or greater, e.g. 400 meq/g.
Other materials such as clays, particularly of the water-insoluble types, may be useful adjuncts in compositions of this invention. Particularly useful is bentonite. This material is primarily montmorillonite which is a hydrated aluminum silicate in which about l/6th of the aluminum atoms may be replaced by magnesium atoms and with which varying amounts of hydrogen, sodium, potassium, calcium, etc., may be loosely combined. The bentonite in its more purified form (i.e. free from any grit, sand, etc.) suitable for detergents invariably contains at least 50~ montmorillonite and thus its ~ .

.

~ 9 62301-1370 cation exchange capacity is at least about 50 to 75 meq. per 100 g. of bentonite. Particularly preferred bentonite are the Wyoming or Western U. S. bentonites which have been sold as Thixo-jels 1, 2, 3 or 4 by Georgia Kaolin Co. These bentonites are known to soften textiles as described in British Patent 401,413 to Marriott and sritish Patent 461,221 to Marriott and Dugan.
Examples of organic alkaline sequestrant builder salts which can be used alone with the detergent or in admixture with other organic and inorganic builders are alkali metal, ammonium or substituted ammonium, aminopolycarboxylates, e.g. sodium and potassium ethylene diaminetetraacetate (EDTA), sodium and potassium nitrilotriacetates (NTA) and triethanolammonium N-(2-hydroxyethyl)nitrilodiacetates. Mixed salts of these poly-carboxylates are also suitable.
Other suitable builders of the organic type include carboxymethylsuccinates, tartronates and glycollates. Of special value are the polyacetal carboxylates. The polyacetal carboxylates and their use in detergent compositions are described in 4,144,226; 4,315,092 and 4,146,495. Other patents on similar builders include 4,141,676; 4,169,934; 4,201,858;
4,204,8~2; 4,224,420; 4,225,685; 4,226,960; 4,233,422;
4,233,423; 4,302,564 and 4,303,777.
Since the compositions of this invention are generally highly concentrated, and, therefore, may be used at relatively low dosages, it is desirable to supplement any phosphate builder (such as sodium tripolyphosphate) with an auxiliary builder such as a polymeric carboxylic acid having high calcium binding capacity to inhibit incrustation which could otherwise be caused by formation of an insoluble calcium phosphate. Such *

Trade-mark ~ 9 62301-1370 auxiliary builders are also well known in the art.
Various other detergent additives or adjuvants may be present in the detergent product to give it additional desired properties, either of functional or aesthetic nature.
Thus, there may be included in the formulation, minor amounts of soil suspending or anti-redeposition agents, e.g. polyvinyl alcohol, fatty amides, sodium carboxymethyl cellulose, hydroxy-propyl methyl cellulose; optical brighteners, e.g. cotton, amine and polyester brighteners, for example, stilbene, triazole and benzidene sulfone compositions, especially sulfonated substituted triazinyl stilbene, sulfonated naphtho-triazole stilbene, benzidene sulfone, etc., most preferred are stilbeneand triazole combinations.
Bluing agents such as ultramarine blue; en2ymes, preferably proteolytic enzymes, such as subtilisin, bromelin, papain, trypsin and pepsin, as well as amylase type enzymes, lipase type enzymes, and mixtures thereof; bactericides, e.g.
tetrachlorosalicylanilide, hexachlorophene; fungicides; dyes;
pigments (water dispersible); preservatives; ultraviolet absorbers; anti-yellowing agents, such as sodium carboxymethyl cellulose, complex of C12 to C22 alkyl alcohol with C12 to C18 alkylsulfate; pH modifiers and pH buffers; color safe bleaches, perfume, and anti-foam agents or suds-suppressors, e.g. silicon compounds can also be used.
The bleaching agents are classified broadly, for convenience, as chlorine bleaches and oxygen bleaches.
Chlorine bleaches are typified by sodium hypochlorite (NaOCl), potassium dichloroisocyanurate (59% available chlorine), and trichloroisoisocyanuric acid (85~ available chlorine). The oxygen bleaches are preferred and are represented by per-compounds which liberate X

' -hydrogen peroxide in solution, i.e. compounds containing hydrogen peroxide or inorganic perhydrates which, when dissolved, liberate hydrogen peroxide enclosed in their crystal lattice.
Preferred examples include sodium and potassium perborates, percarbonates, and perphosphates, and potassium monopersulfate.
The perborates, particularly sodium perborate monohydrate, is especially preferred.
Hydrogen peroxide and the precursors which liberate it in solution are good oxidizing agents for removing certain stains from cloth, especially stains caused by wine, tea, coffee, cocoa, fruits, etc.
Hydrogen peroxide and its precursors have been found in general to bleach quickly and most effectively at a relatively high temperature, e.g. about 80C to 100C. However, such compounds tend to decompose and liberate gaseous oxygen at lower temperatures. The liberation of gaseous oxygen, which is not involved in oxidation of dyed goods, needlessly consumes a sizable amount of hydrogen peroxide or precursors liberating it, both of which are expensive products. Moreover, it has been found that the various stains in cloth and the like greatly accelerates decomposition of hydrogen peroxide into gaseous oxygen during washing at ordinary temperature.
In general, washing cloth, either in a machine, by hand, or in boiler or tubs, is accomplished by dissolving a bleaching or detergent composition (containing perborate, for example) in cold or lukewarm water, adding to the solution thus formed the soiled cloth (from which some of the s~rains have often already been removed by soaking or previous washing) and heating, often just to boiling.
However, it was found that, by a phenomenon similar to that previously mentioned, all or part of the perborate was decomposed during heating and more specifically during the temperature rise, i.e. that all or part of the perborate was decomposed before the really effective temperature is reached.
It is believed that this rapid decomposition of hydrogen peroxide r perborate, or other precursors of hydrogen peroxide into gaseous oxygen at low temperature is due to the extremely powerful catalytic action of certain enzymes which are always present in stains, which are present on materials to be washed, and particularly on soiled cloth, such as linens, these enzymes coming from secretions or being of bacterial origin. Hydroperoxides are an especially active group of enzymes in this respect, particularly catalase, which is well known as a highly effective catalyst for decomposing hydrogen peroxide to gaseous oxygen. Such enzyme substances, whether termed "redox" or otherwise are nevertheless uniformly characterized in exhibiting a pronounced tendency to induce decomposition of peroxide bleaching agent, the decomposition products evolved thereby comprising ineffective bleaching species.
In order to take advantage of the low temperature effective detergents and low temperature washing cycles now commonly used for temperature sensitive fabrics, the peroxygen compound is preferably used in admixture with an activator therefor. Suitable activators which can lower the effective operating temperature of the peroxide bleaching agent to about 40C (104F) or less, are disclosed, for example, in U. S.
Patent 4,264,466 or in column of U. S. Patent 4,430,244.
Polyacylated compounds are preferred activators; among these, compounds such as tetraacetyl ethylene diamine ("TAED") and pentaacetyl glucose are particularly preferred. Other useful activators include for instance acetylsalicyclic acid and X

-~- 62301-1370 ~O~g its salts, ethylidene benzoate acetate (EBA) and its salts, ethylidene carboxylate acetate and its salts, alkyl and alkenyl succinic anhydride, tetraacetylglycouril (TAGU), and the derivatives of these. See also U. S. Patents 4,111,826, 4,422,950 and 3,661,789 for other classes of activators useful herein.
The bleach activator usually interacts with the peroxygen compound to form a peroxyacid bleaching agent in the wash water. It is preferred to include a sequestering agent of high complexing power to inhibit any undesired reaction between such peroxyacid and hydrogen peroxide in the wash solution in the presence of metal ions. Preferred sequestering agents are able to form a complex with Cu2+ ions, such that the stability constant (pK) of the complexation is equal to or greater than 6, at 25C, in water, of an ionic strength of 0.1 mole/liter, pK being conventionally defined by the formula: pR=-log K where K represents the equilibrium constant. Thus, for example, the pK values for complexation of copper ion with NTA and EDTA at the stated conditions are 12.7 and 18.8, respectively. Suitable sequestering agents include for example, in addition to those mentioned above, diethylene triamine pentaacetic acid (DETPA);
diethylene triamine pentamethylene phosphonic acid (DTPMP);
and ethylene diamine tetramethylene phosphonic acid (EDITEMPA).
However, even in the presence of the bleach activators, and even at temperatures as low as room temperature, decomposition of the persalt will occur in the presence of the stained cloth since the rate of reaction between the bleaching agent and the activator is slower than the rate of decomposition of hydrogen peroxide by catalase.
In order to avoid loss of bleaching agent resulting from enzyme-induced decomposition, the compositions of this ~ 6~9 62301-1370 invention will preferably additionally include an effective amount of a compound capable of inhibiting this enzyme-induced decomposition of this invention will preferably additionally include an effective amount of a compound capable of inhibiting this enzyme-induced decomposition of bleaching agent. Suitable inhibitor compounds are disclosed in U. S. Patent 3,606,990.
Of special interest and importance as the inhibitor compound is hydroxylamine sulfate and other water-soluble hydroxylamine salts, including, for example, hydrochloride, hydrobromide, etc. It has now been found that the hydroxylamine salts, especially the sulfate, are effective to inhibit the deletorious effect of catalase even when present in the composition in very limited amounts, for example, less than 0.5%, such as 0.01 to 0.4%, preferably 0.04 to 0.2%, and especially preferably about 0.1%, based on the weight of the total composition.
Furthermore, the hydroxylamine inhibitor is highly ; stable in the composition: less than 20% loss after aging for 2 months at 43C. The hydroxylamine salts are very rapidly solubilized in water and can accordingly react with catalase before dissolution of the perborate or other peroxide bleaching agent. Another advantage of the hydroxylamine salts is that they are rapidly destroyed in the washing liquor, and consequently, no nitrosamine derivatives have been detected.
Where the bleaching system is activated by one of the bleach activators, e.g. TAED, the activator is utilized more effectively and, therefore, suitable ratios of persalt bleaching agent/bleach activator can be maintained at levels much closer to the stoichiometric equivalent weights or with only small molar excess of the bleaching agent.

--The composition may also contain an inorganic insoluble thickening agent or dispersant of very high surface area such as finely divided silica of extremely ~ine particle size (e.g. of 5-100 millimicrons diameters such as sold under the name Aerosil) or the other highly voluminous inorganic carrier materials disclosed in U.S. Patent 3,630,929, in proportions of 0.1-10%, e.g. 1 to 5%. It is pre~erable, however, that compositions which form peroxyacids in the wash bath (e.g. compositions containing peroxygen compound and activator therefor) be substantially free of such compounds and of other silicates; it has been found, for instance, that silica and silicates promote the undesired decomposition of the peroxyacid.
In a preferred form of the invention, the mixture of liquid nonionic surfactant and solid ingredients is subjected to an attrition type of mill in which the particle sizes of the solid ingredients are reduced to less than about 10 micron .
e.g. to an average particle size of 2 to 10 microns or even lower ~e.g. 1 micron). Compositions whose dispersed particles are of such small size have improved stability against separation or settling on storage.
In the grinding operation, it is preferred that the proportion of solid ingredients be high enough (e.g. at least about 40% such as about 50%) that the solid particles are in contact with each other and are not substantially shielded from one another by the nonionic surfactant liquid. Mills which employ grinding balls (ball mills) or similar mobile grinding elements have given very good results. Thus, one ~ay Ise a laboratory batch attritor having 8 mm diameter steatite grinding balls. For larger scale work a continuously ~ 9 _~ I

operating mill in which there are I mm or 1.5 mm diameter grinding balls working in a very small gap between a stator and a rotor operating at a relatively high speed (e.g. a CoBall mill) may be employed; ~hen using such a mill, it is desirable to pass the blend of nonionic surfactant and solids first through a mill wh:ich does not effect such fine grinding (e.g. a colloid mill) to reduce the particle size to less than 100 microns (e.g., to about 40 microns) prior to the step of grinding to an average particle diameter below about 10 microns in the continuous ball mill.
In the preferred heavy duty liquid detergent compositions of the invention, typical proportions (based on the total composition, unless otherwise specified) of the ingredients are as follows:
Suspended detergent builder, within the range of about 10 to 60% such as about 20 to 50%, e.g. about 25 to 40%;
Liquid phase comprising-nonionic surfactant and dissolved amphiphilic viscosity-controlling and gel-inhibiting compound, within the range of about 30 to 70%, such as about 40 to 60%; this phase may also include minor amounts of a diluent such as a glycol, e.g. polyethylene glycol (e.g., "PEG 400"), hexylene glycol, etc. such as up to 10%, preferably up to 5%, for example, 0.5 to 2%. The weight ratio of nonionic surfactant to amphiphilic compound is in the range of from about 100:1 to 1:1, preferably from about 50:1 to about 2:1, especiae), hexylrably, from about 25:1 to about 3:1.
Polyether carboxylic acid gel-inhibiting compound, in an amount to supply in the range of about 0.5 to 10 parts (e.g. about 1 to 6 parts, such as about 2 to 5 parts) of -COOH (M.W. 45) per 100 parts of blend of such acid compound --- ~ 9~9 I
and nonionic surfactant. Typically, the amount of the polyether carboxylic acid compound is in the range of about 0.01 to 1 part per part of nonionic surfactant, such as about 0.~5 to 0.6 part, e.g. about 0.2 to 0.5 part;
Acidic organic phosphoric acid compound, as anti-settling agent: up to 5%, for example, in the range of 0.01 to 5%, such as about 0.05 to 2%, e.g. about 0.l to 1%.
Suitable ranges of other optional detergent additives are: enzymes - 0 to 2%, especially 0.7 to 1.3%; corrosion inhibitors - about 0 to 40%, and prefe~rably 5 to 30%; anti-foam agents and suds-suppressors - 0 to 15%, preferably 0 to 5%, for example 0.1 to 3%; thickening agent and dispersants -0 to 15%, for example O.l to 10%, preferably 1 to 5%; soil suspending or anti-redeposition agents and anti-yellowing agents - 0 to 10%, preferably 0.5 to 5%; colorants, perfumes, brighteners and bluing agents total weight 0% to about 2~/~
and preferably 0% to about 1%; pH modifiers and pH buffers - O to 5%~ preferably 0 to 2%; bleaching agent - ~/0 to about 40% and preferably 0% to about 25%, for example 2 to 20%;
inhibitor compound for inhibiting enzyme-induced decomposi~ion of bleaching agent - up to about 0.5%, preferably 0.01 to 0.4 or 0.5/" more preferably 0.04 to 0.2%; bleach stabilizers and bleach activators 0 to about 15%, preferably 0 to 10%, for example, 0.1 to 8%; sequestering agent of high comple~ing power, in the range of up to about 5%, preferably about 1/4 to 3%, such as about 1/2 to 2%. In the selections of the adjuvants, they will be chosen to be compatible with the main constituents of the detergent composition.
All proportions and percentages are by weight unless orher~ise indicated.
It is understood that the foregoing detailed description is given merely by way of illustration and that variations 6;~9 may be made therein without departing from the spirit of the invention.
In order to demonstrate the effec-ts of the viscosity control and gel-inhibiting agents, various compositions were prepared using the above described Surfactant T8 (C13, E08) (50/
50 weight mixture of Surfactant T7 and Surfactant T9) as the non-aqueous liquid nonionic surface active cleaning agent. Formula-tions containing 5%, 10%, 15%, or 20% of amphiphilic additlve were prepared and were tested at 5C, 10C, 15C, 20C and 25C
for different dilutions with water, i.e. 100%, 83%, 67%, 50% and 33% total nonionic Surfactant T8 plus additive concentrations, i.e. after dilution in water. The additives tested were Alfonic 610-60 (C8-E04.4), ethylene glycol monoethyl ether (C2-E01), and diethylene glycol monobutyl ether (C4-E02). The results of vis-cosity behavior on dilution of each tested composition at each temperature were obtained.
For Alfonic 610-60, 5% addition was sufficient to inhibit gelation at 25C; however, in the plot of viscosity vs.
concentration of nonionic a sharp viscosity maximum was observed at about 67% concentration and a shoulder was observed at about 55% to 35% nonionic concentration. At 5C, 15% addition was necessary to avoid gel formation. The viscosity decreased to a minimum at a nonionic concentration of about 83% at all levels of additive addition at 5C whereas at the higher temperatures, viscosity minimums were observed for the non-diluted formulations, i.e. 100% nonionic concentrations. At each temperature and for each tested concentration of additive (except at 20% additive at 25C) a relatively sharp peak is seen in the viscosity existing between 75 to 50% concentration of nonionic (i.e. 25 to 50%

dilution).
For ethylene glycol monoethyl ether 5% additive was capable of inhibiting gel formation even at 5C. However, ,~"

--~

sharp peaks and/or maxima of viscosity were again observed at each temperature and additive concentration, although the effects were not as pronounced as for Alfonic 610-60, and for some applications the maximum viscosities, especially at higher additive concentrations and/or higher temperatures could be acceptable for commercial use.
On the other hand, there were no sharp peaks in viscosity observed for diethylene glycol monobutyl ether at any temperature down to 5C at the 20% add;tive level. Even at the lower additive levels the viscosity peaks and the viscosity values at substantially all dilutions (concentrations of nonionics) were lower than for either the C8-EO4.4 or C2-EOl additive.
The following table is representative of the results which were obtained for the different additive concentrations, dilutions, and temperatures, but are given for 20% additive and 5C temperature:

Compositions Viscosity Pour Point at 5C (Pa-sec) (C) No Water 50% 7~7ater Surfactant T8 only 1.140 1.240 5 80% Surfactant T8~20%A 0.086 0.401 -10 80% Surfactant T8+20%B 0.195 0.218 -2 80% Surfactant T8+20%C 0.690 0.936 3 A = ethylene glycol monoethyl ether B = diethylene glycol monobutyl ether C = Alfonic 610-60 (C8-4.4EO) Note: 1 Pa sec = 10 poises (e.g. 0.218 Pa-sec = 218 centipoises) - ~ 62301-1370 Example _ A heavy duty built non-aqueous liquid nonionic cleaning composition having the following formula is prepared:
Ingredient Weight~
. _ Surfactant T7 17.0 Surfactant T8 1 17.0 Dobanol 91-5 Acid 5.0 Diethylene glycol monobutyl ether 10.0 Dequest 2066 ' 1.0 TPP NW (sodium tripolyphosphate) 29.0925 Sokolan CP5 3 (calcium sequestering agent) 4.0 Perborate H2O (sodium perborate morlohydrate) 9.0 T.A.E.D. (tetraacetylethylene diamine) 4.5 Emphiphos 5632 4 0.3 Stilbene 4 (optical brightener) 0.5 Esperase (proteolytic enzyme) 1.0 Duet 787 5 0.6 Relatin DM 4050 6 (anti-redeposition agent) 1.0 Blue Foulan Sandolane (dye) 0.0075 1) The esterification product of Dobanol 91-5 la Cg-Cll fatty alcohol ethoxylated with 5 moles ethylene oxide) with succinic anhydride - the half-ester.
2) Diethylene triamine pentamethylene phosphoric acid, sodium salt.
3) A copolymer of about equal moles of methacrylic acid and maleic anhydride, completely neutralized to form the sodium salt thereof.
4) Partial ester of phosphoric acid and a C16 to C18 alkanol about 1/3 monoester and 2/3 diester.
5) Fragrance.
6) Mixture of sodium carboxylmethyl cellulose and hydroxymethylcellulose.
This composition is a stable, free-flowing, built, non-gelling, liquid nonionic cleaning compositions in which the polyphosphate builder is stably suspended in the liquid nonionic surfactant phase.

X

-~ ~ 9 -~

Example 2 In the same manner as in Example 1, the following heavy duty built non-aqueous liquid nonionic cleaning composition containing an enzyme inhibitor is prepared:

In~redient Wei~ht%

Plurafac RA 30 37.5 Diethyleneglycol monobutyl ether 10.0 Octenylsuccinic anhydride 2.0 TPP NW 28.4 Sokolan CP5 4.0 Dequest 2066 1.0 Perborate H2O 9.0 TAED 4-~
Hydroxylamine sulfate 0.1 Emphiphos 5632 0.3 ATS-X (optical brightener) 0.2 Esperase 1.0 Perf~me 0.S
Rela~in DM 4050 1.0 TiO2 0.4 This composition has the same advantageous features as the composition of Exar.lple 1 and, in addition, provides improved bleaching performance.

Claims (20)

1. A non-aqueous liquid detergent composition capable of washing and bleaching soiled fabrics at temperatures as low as about 40°C or less which comprises a liquid nonionic surfactant, a mono or poly(C2 to C3)alkylene glycol mono(C1 to C5)alkyl ether, a water-soluble inorganic peroxide bleaching agent, a bleach activator to lower the temperature at which the bleaching agent will liberate hydrogen peroxide in aqueous solution, and from about 0.01 to 0.4 percent by weight, based on the total composition, of an hydroxylamine salt capable of inhibiting the enzyme-induced decomposition of the bleaching agent, said enzyme being present in the soiled fabrics.

2. The composition of claim 1 wherein the bleaching agent is a perborate, percarbonate, perphosphate or persulfate.

3. The composition of claim 2 wherein the hydroxylamine salt is hydroxylamine sulfate, hydroxylamine hydrochloride, or hydroxylamine hydrobromide.

4. The composition of claim 1 wherein the bleach activator is N,N,N',N'-tetra-acetyl ethylene diamine.

5. The composition of claim 1 wherein the bleaching agent comprises sodium perborate monohydrate, the bleach activator is N,N,N',N'-tetra-acetyl ethylene diamine and the hydroxylamine salt is hydroxylamine sulfate or hydroxylamine hydrochloride and is present in an amount of from about 0.02 to 0.2%.

6. The composition of claim 1 which further comprises a detergent builder salt suspended in the liquid nonionic surfactant.

7. The composition of claim 1 wherein the bleach activator will react with the bleaching agent in an aqueous wash bath to form a peroxyacid bleaching agent at a temperature of about 40°C or less.

8. A non-aqueous liquid detergent composition capable of washing and bleaching soiled fabrics at temperatures as low as about 40°C. or less which comprises a liquid phase comprising nonionic surfactant and a mono or poly (C2 to C3) alkylene glycol mono (C1-C5) alkyl ether in an amount of 30 to 70%, a water-soluble inorganic peroxide bleaching agent in an effective amount of up to 25%, a bleach activator to lower the temperature at which the bleaching agent will liberate hydrogen peroxide in aqueous solution in an effective amount of up to 10%, proteolytic enzyme in an amount of from about 0.7 to 2 percent by weight and from about 0.01 to 0.4 percent by weight, based on the total composition, of an hydroxylamine salt capable of inhibiting the enzyme-induced decomposition of the bleaching agent, said enzyme being present in the soiled fabrics.

9. The composition of claim 8 wherein the bleaching agent comprises sodium perborate monohydrate in an effective amount of up to 25%, the bleach activator is N,N,N',N'-tetra-acetyl ethylene diamine in an effective amount of up to 10% and the hydroxylamine salt is hydroxylamine sulfate or hydroxylamine hydrochloride in an amount of about 0.02 to 0.2%.

10. The composition of claim 8 which further comprises about 20 to 50% of a detergent builder salt suspended in the liquid nonionic surfactant.

11. A non-aqueous liquid laundry detergent composition comprising about 30 to 70% by weight of a liquid phase comprising a liquid nonionic surfactant, about 20 to 50% by weight of detergent builder salt suspended in the liquid phase, about 2 to 20% by weight of an alkali metal perborate bleaching agent, about 0.1 to 10% by weight of a bleach activator to lower the temperature at which the bleaching agent will liberate hydrogen peroxide in aqueous solution, about 0.7 to 2% by weight of proteolytic enzyme, and about 0.01 to 0.4% by weight of hydroxylamine salt capable of inhibiting the enzyme-induced decomposition of the bleaching agent.

12. The detergent composition of claim 11 wherein the hydroxylamine salt is hydroxylamine sulfate or hydroxylamine hydrochloride and is in an amount of about 0.04 to 0.2% by weight.

13. The detergent composition of claim 11 wherein the detergent builder salt comprises about 25-40% by weight of an alkali metal tripolyphosphate.

14. A non-aqueous liquid laundry detergent-bleaching composition comprising a liquid phase comprising liquid nonionic surfactant, a detergent builder salt suspended in the liquid phase, an effective amount of a water-soluble inorganic peroxide salt bleaching agent selected from the group consisting of perborate, percarbonate, perphosphate and persulfate, an effective amount of a bleach activator compound which will react with the bleaching agent in an aqueous wash bath to form a peroxy bleach agent at a temperature of about 40°C. or less, an effective amount of a proteolytic enzyme, and an effective amount in the range of from about 0.01 to about 0.4% by weight of the composition of an hydroxylamine salt to inhibit enzyme-induced decomposition of the peroxide salt bleaching agent.

15. The composition of claim 14 wherein the hydroxylamine salt is hydroxylamine sulfate, hydroxylamine hydrochloride, or hydroxylamine hydrobromide.

16. The composition of claim 14 wherein the bleach activator compound comprises N,N,N',N'-tetra-acetyl ethylene diamine and is present in an amount of from about 0.1 to 8% by weight of the composition.

17. A non-aqueous liquid laundry detergent composition consisting essentially of about 40 to 60% by weight of a liquid nonionic surfactant and a viscosity-controlling and gel-inhibiting compound of the formula where R is alkyl of 2 to 5 carbon atoms, R' is hydrogen or methyl, and n is a number from 2 to 4 on average, wherein the weight ratio of nonionic surfactant to said viscosity-controlling and gel-inhibiting compound being from 50:1 to 2:1, about 20 to 50% by weight of detergent builder salt suspended in the liquid phase, about 2 to 20% by weight of an alkali metal perborate bleaching agent about 0.1-8% by weight of tetraacetylene diamine bleach activator, about 0.7 to 2% by weight of proteolytic enzyme, and about 0.01 to 0.4% by weight of hydroxylamine salt capable of inhibiting the enzyme induced decomposition of the bleaching agent.

18. The detergent composition of claim 17 wherein the liquid nonionic surfactant is comprised of C10 to C18 fatty alcohol ethoxylated with from 3 to 12 moles of a C2 to C3 alkylene oxide per mole of fatty alcohol and the compound of the formula is diethylene glycol monobutylether, and the detergent builder salt comprises from about 25 to 40% by weight of an alkali metal tripolyphosphate.

19. A method for cleaning and bleaching soiled fabrics which comprises contacting the soiled fabrics with a composition according to any one of claim 1 to claim 18 in an aqueous wash bath.

20. The method of claim 19 wherein the aqueous wash bath has a temperature of about 40°C or less.