Field of the Invention

This invention relates to nonaqueous microemulsion compositions and especially nonaqueous microemulsion detergent compositions. More specifically, it is of a liquid detergent composition in a microemulsion state or form, which by virtue of its microemulsion nature and ready convertibility to a cleaning solution, when brought into contact with water, is superior to other liquid detergent compositions in detergency and in other physical properties. In particular, the detergent composition can be a nonaqueous concentrate which upon dilution with water forms a microemulsion.

This invention also relates to a liquid crystalline composition and especially a liquid crystalline detergent composition. More specifically, it is of an essentially non¬ aqueous detergent composition in liquid crystal state or form which, by virtue of both its non-aqueous and liquid crystalline nature, is superior to other liquid detergent compositions because it is able to incorporate and/or suspend water sensitive ingredients which impart to the composition a superior efficacy in cleaning tasks. Additionally, the composition could be converted to a microemulsion when brought into contact with water. Background of the Invention

Liquid aqueous synthetic organic detergent compositions have long been employed for human hair shampoos and as dishwashing detergents for hand washing of dishes (as distinguished from automatic dishwashing, machine washing of dishes). Liquid detergent compositions have also been employed as hard surface cleaners, as in pine oil liquids, for cleaning floors and walls. More recently, they have proven successful as laundry detergents too, apparently because they are convenient to use, are instantly soluble in wash water, and may be employed in "pre-spotting" applications to facilitate removal of soils and stains from laundry upon subsequent washing. Liquid detergent compositions have comprised anionic, cationic and

nonionic surface active agents, builders and adjuvants including, as adjuvants, lipophilic materials which can act as solvents for lipophilic soils and stains. The various liquid aqueous synthetic organic detergent compositions mentioned above serve to emulsify lipophilic materials including oily soils in aqueous media, such as wash water, by forming micellar dispersions and emulsions.

Although emulsification is a mechanism of soil removal, it has been only recently that it was discovered how to make microemulsions which are much more effective than ordinary emulsions in removing lipophilic materials from substrates. Such microemulsions are described in British Patent Specification No. 2,190,681 and U.S. Patent Applications Serial Nos. 06/866,029, 07/085,902, 07/120,250 and

07/267,872 most of which relates to acidic microemulsions useful for cleaning hard surface items such as bathtubs and sinks, which microemulsions are especially effective in removing soap scum and lime scale from them. In U.S. Patent Application Serial No. 07/267,872 the microemulsions may be essentially neutral and as such are also thought to be effective for microemulsifying lipophilic soils from substrates. In U.S. Patent Application Serial No. 07/313,664 there is described a light duty microemulsion liquid detergent composition which is useful for washing dishes and removing greasy deposits from them in both neat and diluted forms. Such compositions includes complexes of anionic and cationic detergents as surface active components of the microemulsions.

The various microemulsions referred to include a lipophile which may be a hydrocarbon, a surfactant which may be an anionic and/or a nonionic detergent(s), a co-surfactant which may be a poly-lower alkylene glycol lower alkyl ether, e.g. tripropylene glycol monomethyl ether, and water. Although the manufacture and use of detergent compositions in microemulsion form significantly improves cleaning power and greasy soil removal, compared to the usual emulsions, the present invention improves them still further and also increases the capacity of the detergent compositions to adhere to surfaces to which they have been applied. Thus, they drip or run substantially less than cleaning compositions of

"similar" cleaning power which are in normal liquid detergent form. Also, because they will probably form gels with water spontaneously depending upon the amount of dilution with water, with essentially no requirement for addition of any energy, either thermal or mechanical, they are more effective cleaners at room temperature, especially for vertical walls in the gel form and at higher and lower temperatures that are normally employed in cleaning operations than are ordinary liquid detergents and are also more effective than detergent compositions in solution form. The instant compositions can be formed as nonaqueous concentrates which the consumer can use by dilution with water thereby minimizing the amount of waste generated. Nonaqueous microemulsions of glycerol/sodium dodecyl sulfate/hexanol/alcane, of ethylene glycol/lecithin/decane and of ethylene glycol/sodium dodecyl sulfate/toluence/decanol have been disclosed by Friberg and Co. in Colloids and Surfaces, 24 (1987) 325-336, in Colloid and Polymer Science 262, (1984) 252-253 and in Colloid and Polymer Science 268, (1990) 755-759 respectively. Rico and Lattes claim the formation of microemulsions of formamide/cetyltrimethylamonium bromide/cyclohexane/1-butanol, and of formamide/potassium 2,2,3,3 tetrahydroperfluoroundecanoate/1 ,1 ,2,2, tetrahydroperflurohexanol/perflourinated oils in Nouveau Journal de Chimie \lo\. 8, No. 7, 1984, p 429 and Journal of Colloid and Interface Science Vol. 102, No. 1 , Nov 1984 respectively. Nonaqueous microemulsions of formamide/nonionic surfactants/hydrocarbons and of formamide/didodecyldimethylamonium bromide/toluene have been disclosed by Warnheim and Co. in Journal of Colloid and Interface Science Vol. 131 , No.2, Sept. 1989 and in Progr. Colloid Polym. Sci, 82: 271-279 (1990) respectively. Durfler and Co. claim the formation of microemulsions of NN dimethyl formamide/Triton® x 114/dodecane/n-pentanol, of nitromethane/Triton® x 114/dodecane/n-pentanol in Tenside Surf, Det. 28 (1991 ), 3, 167-172. The major part of the above mentioned nonaqueous systems are not environmentally safe for consumer use. Due to ingredient toxicity, the use of nonionic surfactants in combination with aliphatic hydrocarbons and a nonaqueous polar solvent has not

been disclosed for the formation of microemulsions in nonaqueous solvents which can be used in consumer detergents.

The nonaqueous microemulsion compositions are applicable for use in concentrated household care products and personal care products because they can contain water-incompatible active ingredients such as bleachants and/or enzymes. The nonaqueous microemulsion compositions of the instant invention comprise harmless ingredients as compared to the formamide used by T. Wamheim and M. Sjoberg which could never be used in household or body care products. The instant microemulsion compositions permit the preparation of super concentrated cleaning or conditioning liquid products containing high levels of nonionic surfactants. The instant nonaqueous microemulsion compositions of the instant invention are less temperature-sensitive than aqueous-based microemulsion compositions of the instant invention and therefore have improved storage stability.

Nonaqueous liquid crystals of glycerol/sodium dodecyl sulfonate/Decanol have been disclosed by Friberg and Co. in Colloids and Polymer Science 264: 449-453 (1986). Rico and Lattes claim the formation of liquid crystals of formamide/cetyltrimethylamonium bromide/cyclohexane/1-butanol and of formamide/potassium 2,2,3,3 tetrahydroperfluoroundecanoate/ 1 ,1 ,2,2 tetrahydroperfluorohexanol/perfluorinated oils in Nouveau Journal de Chimie vol. 8, N°- 7, 1984, p 429 and in Journal of Colloid and Interface Science Vol. 102, N°- 1 , Nov. 1984 respectively. Liquid crystals of cationic surfactants and various polar solvents have been disclosed by Warnheim and Co. in Progr. Colloid Polymer Science, 82: 271- 279 (1990) and in Journal of Colloid and Interface Science, Vol 125, N°2 (Oct. 1988). The use of nonionic surfactants in combination with aliphatic hydrocarbons and nonaqueous polar solvent has not been disclosed for the formation of liquid crystals in nonaqueous solvents which can be used in consumer detergents.

The instant nonaqueous microemulsion compositions can form a gel upon a minimum dilution with water and as such are applicable in oral products. A thin layer of the nonaqueous microemulsion could be sprayed or otherwise deposited on the

teeth (or on the brush) and subsequently gelled or thickened by the saliva to allow brushing. In accordance with the present invention, a liquid detergent composition, suitable at room temperature or colder or at a higher temperature for pre-treating and cleaning materials soiled with a lipophilic soil, is in a nonaqueous microemulsion form and comprises a nonionic surface active agent, an aliphatic hydrocarbon, a nonaqueous polar solvent and, optionally, a polar co-solvent. The invention also relates to processes for treating items and materials soiled with soils such as a lipophilic soil, with compositions of this invention, to loosen to remove such soil by applying to the locus of such soil on such material a soil loosening or removing amount of the compositions of the microemulsion compositions of the instant invention. The invention is also being in the conversion of the nonaqueous microemulsion liquid composition by the addition of water thereto into a gel or a solution depending upon the amount of the water addition. In another aspect of the invention, lipophilic soil is absorbed from the soiled surface into the nonaqueous microemulsion and then contacted with water so as to convert the microemulsion to solution form. Summary of the Invention

The instant invention relates to a liquid crystal or pseudo microemulsion composition having an apparent viscosity at 10 ² sec ^"1 of about 1 to 1000 cps, more preferably about 1 to 700 cps which comprises approximately by weight 7 to 50% of a nonionic surface active agent; 5 to 70% of an aliphatic hydrocarbon having about 9 to 15 carbon atoms; 0 to 50% of an essentially nonaqueous polar cosolvent having a Hildebrand hydrogen bonding solubility parameter at 25°C of at least 15.4 and a Hildebrand polar solubility parameter at 25°C of at least 5 and 10 to 80% of a nonaqueous polar solvent having a Hildebrand hydrogen bonding solubility parameter at 25°C of at least 12.3 and a Hildebrand polar solubility parameter at 25°C of at least about 8 (MPa) ^{1 2} .

The instant invention also relates to a liquid crystal composition having an apparent viscosity at 10 ^{" 2} sec ^{" 1} of about 7.5 to about 300 Pa. sec. centipoises, more

preferably 5 to 20 Pa. sec. and an apparent viscosity at 10 ² sec" ¹ of about 0.05 to about 7.5 Pa.seα, more preferably 0.05 to 0.5 Pa. sec. which comprises approximately by weight 7 to 50% of a nonionic surface active agent; to 5 to 32% of an aliphatic hydrocarbon having about 9 to 15 carbon atoms, and 10 to 60% of a nonaqueous polar solvent having a Hansen hydrogen bonding cohesion parameter ( d h) at 25°C of at least 15.0 MPa ¹ / ² and Hansen polar cohesion parameter (d p) at 25°C of at least about 10 MPa ² as set forth in the Handbook of Solubility Parameters by Allan K.M. Barton, CRC Press, Pages 94-109 and 153-161 (1983).

Accordingly, it is an object of the instant invention to provide a microemulsion composition which is useful in a cleaning operation and is possibly convertible into a gel by contacting the microemulsion composition with water, wherein the gel is further convertible into a solution by contacting the gel with a further amount of water.

Another object of the instant invention is to provide a nonaqueous microemulsion medium for water sensitive materials such as enzymes and/or bleachants.

A still further object is to provide a detergent composition in a microemulsion form which exhibits improved adherence onto vertical surfaces, when the composition is applied to the vertical surfaces in neat form such as by spraying.

Accordingly, it is also an object of the instant invention to provide a liquid crystal composition which is useful in a cleaning operation and can be possibly converted into a microemulsion by contacting the liquid crystal composition with water.

Another object of the instant invention is to provide a nonaqueous liquid crystal medium for water sensitive materials such as enzymes.

Another object of the instant invention is to provide a nonaqueous liquid crystal medium for the immiscible liquid droplets, abrasive particles, insoluble particles of active ingredients within the suspension medium.

A still further object is to provide a detergent composition in a liquid crystal form which exhibits improved adherence onto vertical surfaces, when the composition is applied to the vertical surface in neat form such as by spraying.

βfjef Description Pf the Drawing?

Figure 1 to 4 illustrate plots of G' and G" (Pa.) against frequency (Hz) for the liquid crystalline compositions pf examples C-D-F-G.

Figure 5 illustrates plot of G' and G" (Pa.) against temperature (°C) for the liquid crystalline composition of example G.

Figures 6 to 10 illustrate plots of apparent viscosity (Pa. sec.) against shear rate (sec ^-1 ) for the liquid crystalline composition compositions of examples A-G-C-E-G.

• Figures 11 to 14 illustrate creep results [plots of strain against time (sec)] for the liquid crystalline compositions of examples A-B-C-E. • Figure 15 illustrates the phase diagram of the composition Ethylene Glycol-5%

Glycerol/Alfol® 1618 9EO/Dodecane; it includes the liquid crystalline composition of examples A-B-C-E-G.

• Figure 16 illustrates the phase diagram of the composition Ethylene Glycol - 3% Dextrose/Alfol® 1618 9EO/Dodecane after 60 days aging; it includes the liquid crystalline composition of example D.

Figure 17 illustrates the phase diagram of the composition Ethylene Glycol/Alfol® 1618 9EG7Tetradecane after 75 days aging; it includes the liquid crystalline compositions of example F.

Figure 18 illustrates the phase diagram of the composition Ethylene Glycol-5% Glycerol/Alfol® 1618 9EO/Tetradecane after 94 days aging.

• Figure 19 illustrates the phase diagram of the composition Ethylene Glycol - 2% Lithium Chloride/Alfol® 1618 9EO/Dodecane after 98 days aging.

Figure 20 illustrates the phase diagram of the composition Ethylene Glycol - 3% Dextrose/Dobanol® 45 8EO/Dodecane after 60 days aging. In figures 16 to 20, the stability of liquid crystals is expressed as the percentage of volume occupied by the liquid crystalline phase in the total composition. Therefore, 100% LC stability means that no phase separation has occurred within the mentioned aging period.

Figures 21-29 illustrate phase diagrams for microemulsion compositions of Example I. Detailed Description of the Invention

The present invention relates to a microemulsion or liquid crystal composition having an apparent viscosity 10 ² sec ^"1 of about 1 to about 10 ³ cps, more preferably about 1 to about 100 cps, which comprises approximately by weight: a) 7 to 50% of a nonionic or ionic surface active agent, more preferably 8 to 45% and most preferably 10 to 45%; b) 5 to 70%, more preferably 5 to 40% and most preferably 10 to 25%, of an aliphatic hydrocarbon which has about 6 to 15 carbon atoms and more preferably 10 to 14 carbon atoms having a Hildebrand solubility dispersion parameter at 25°C of at least about 15.6; or alternatively and less preferred a polar oil; c) 10 to 90%, more preferably 15 to 60% and most preferably 15 to 55%, of an essentially nonaqueous polar solvent having a Hildebrand hydrogen bonding solubility parameter at 25°C of at least 12.2 and more preferably at least 15 and a Hildebrand polar solubility parameter at 25°C of at least 5, more preferably at least 10; d) 0 to 45%, more preferably 0.5 to 25% and most preferably 1 to 5%, of an essentially nonaqueous polar co-solvent having a Hildebrand hydrogen bonding solubility parameter at 25°C of at least 15.4 and a Hildebrand polar solubility parameter at 25°C of at least about 5, more preferably at least about 10.

The present invention also relates to liquid crystalline composition having an apparent viscosity at a shear rate of 10" ² sec ^"1 of about 7.5 to about 300 Pa. sec, more preferably about 5 to about 20 Pa. sec. and at 100 sec" ¹ of about 0.05 to about 7.5 Pa. sec, more preferably about 0.05 to 0.5 Pa. sec. which comprises approximately by weight:

(a) 7 to 50% of a nonionic surface active agent, more preferably 8 to 45%, and most preferably 10 to 45%.

(b) 5 to 30%, more preferably 5 to 25%, and most preferably 10 to 25% of an aliphatic hydrocarbon which has about 6 to 16 carbon atoms and more preferably 10

to 14 carbon atoms and a solubility dispersion parameter (d d) at 25°C of at least 15.6;

(c) 10 to 90%, more preferably 15 to 60%, and most preferably 15 to 55% of a nonaqueous polar solvent having a Hansen hydrogen bonding solubility parameter (d h) at 25°C of at least 12.0 and more preferably at least 15.0; and

(d) 0 to 50% more preferably 0.5 to 25% and most preferably 1 to 5% of an essentially nonaqueous polar cosolvent having a Hansen hydrogen bonding solubility parameter at 25°C of at least 20. By the term "essentially" it is meant that the polar solvent will contain less than about 4 wt. % of water, more preferably about 20 wt. % and most preferably about 10 wt. %.

The microemulsion or liquid crystal compositions of the instant invention can be used as a basic formulation for the production of both commercial and industrial applications by the addition of selective ingredients to the microemulsion composition. Typical compositions which can be formed for a variety of applications are toothpastes, creams or toothpaste gels, cosmetics, hand creams, facial creams, eye shadows, lipsticks, metal polish agents, fabric cleaners, shampoos, floor cleaners, cleaning pastes, tile cleaners, bleach compositions, ointments, oven cleaners, stain removers, fabric softeners, bleach pre-spotters, automatic dishwashing compositions, laundry pre-spotters, pharmaceutical compositions, coal slurries, oil drilling muds, and cleaning pre-spotters.

The nonionic and ionic surfactants and synthetic organic detergents that are employed in the instant cleaning compositions are preferably water soluble, but such materials that are water dispersible can also be used. The soluble nonionic compounds are usually condensation products of an organic aliphatic or alkylaromatic hydrophobic compound and a lower alkylene oxide, such as ethylene oxide or the combination of ethylene oxide and propylene oxide which is hydrophilic. Almost any hydrophobic compound having a carboxy, hydroxy, amido or amino group with a free hydrogen present can be condensed with ethylene oxide or ethylene oxide in combination with propylene oxide or with polyethylene glycol to form a nonionic

detergent. The length of the polyethenoxy chain of the condensation product can be adjusted to achieve the desired balance between the hydrophobic and hydrophilic elements (hydrophilic-lipophilic balance, or HLB).

Particularly suitable nonionic detergents are the condensation products of a higher aliphatic alcohol, such as a fatty alcohol, containing about 7 to 22, more preferably 10 to 18 carbon atoms, in a straight (or branched) chain configuration, condensed with about 4 to 13, preferably 5 to 12, more preferably 5 to 11 and most preferably 5 to 10 moles of ethylene oxide to one mole of the aliphatic alcohol. Particularly preferred such compounds are Ci 9-11 alkanol ethoxylates and 5-8 moles of ethylene oxide, which also may be designated at C 9-11 alcohol EX(EO) wherein X = 5 to 8. Particularly preferred nonionic surfactants are Dobanol 45-8 which is C-14-15 fatty alcohol and 8 ethylene oxide, Dobanol 23-7 which is Ci 2-13 fatty alcohol and 7 ethylene oxide, and Dobanol 91-5 which is C9-11 fatty alcohol and 5 ethylene oxide. Other possible suitable nonionic detergents are the polyethylene oxide condensates of one mole of alkyl phenol containing from about 8 to 20 carbon atoms in a straight or branched chain configuration, with about 5 to 13, preferably 6 to 11 moles, of ethylene oxide such as decyl phenol condensed with 8 moles of ethylene oxide. These aromatic compounds are not as desirable as the aliphatic alcohol ethoxylates in the instant compositions because they are not as biodegradable.

Another well-known group of usable nonionic detergents is marketed under the trade name "Pluronics." These compounds are block co-polymers formed by condensation of ethylene oxide with a hydrophobic base formed by the condensation of propylene oxide with propylene glycol. The molecular weight of the hydrophobic portion of the molecule is of the order of 950 to 4000, preferably 1200 to 2500. The condensation of ethylene oxide with the hydrophobic moiety increases the water solubility of the hydrophobe. The molecular weight of these polymers is in the range of 1000 to 15,000 and the polyethylene oxide content may comprise 20 to 80% thereof.

Still other satisfactory nonionic detergents are condensation products of a Cs- 13 alkanol with a heteric mixture of ethylene oxide and propylene oxide. The mole ratio of ethylene oxide to propylene oxide is from at least 1 :1 to 4:1 , preferably from 1.5:1 to 3.0:1 with the total weight of the ethylene oxide and propylene oxide contents (including the terminal ethanol group or propanol group) being from 60% to 85%, preferably 70% to 80%, of the molecular weight of the nonionic detergent. The higher alkanol may contain 8 to 20 carbon atoms and one such nonionic detergent is the condensation product of C13-15 alkanol with 4 moles of propylene oxide and 7 moles of ethylene oxide, which is available from BASF Corp. under the trade name Plurafac LF400.

Also suitable for incorporation in the invented cleaning compositions are the nonionic detergents that are derived from the condensation of the ethylene oxide with the product resulting from the reaction of propylene oxide and ethylene diamine, for example, satisfactory such compounds contain from about 40 to 80% of polyoxyethylene by weight, have a molecular weight of from about 5000 to 11 ,000, and result from the reaction of ethylene oxide with a hydrophobic base which is a reaction product of ethylene diamine and excess propyoxyethylene oxide, which base is of a molecular weight in the range of 2500 to 3000. Other nonionic surfactants envisioned within the scope of the instant invention are, stearate or isostearate surfactants containing glycerol or soribitan moieties, sulfosuccinates, nonionic surfactants based on Guerbet alcohols, and polymeric surfactants with polycarboxylic backbones.

The alkylpolysaccharides surfactants which are also useful alone or in conjunction with the aforementioned surfactants and have a hydrophobic group containing from about 8 to about 20 carbon atoms, preferably from about 10 to about 16 carbon atoms, most preferably from 12 to 14 carbon atoms, and polysaccharide hydrophilic group containing from about 1.5 to about 10, preferably from 1.5 to 4 and most preferably from 1.6 to 2.7, saccharide units (e.g. galactoside, glucoside,

fructoside, glucosyl, fructosyl and/or galactosyi units). Mixtures of saccharide moieties may be used in the alkylpolysaccharide surfactants. The number x indicates the number of saccharide units in a particular alkylpolysaccharide surfactant. For a particular alkylpolysaccharide molecule, x can only assume integral values. In any physical sample it can be characterized by the average value of x and this average value can assume non-integral values. In this specification the values of x are understood to be average values. The hydrophobic group (R) can be attached at the 2-, 3- or 4-positions rather than at the 1 -position (thus giving, e.g., a glucosyl or galactosyi as opposed to a glucoside or galactoside). However, attachment through the 1 -position, i.e. glucosides, galactosides, fructosides, etc., is preferred. In the preferred product the additional saccharide units are predominantly attached to the previous saccharide unit's 2-position. Attachment through the 3-, 4- and 6-positions can also occur. Optionally and less desirably there can be a polyalkoxide chain joining the hydrophobic moiety (R) and the polysaccharide chain. The preferred alkoxide moiety is ethoxide.

Typical hydrophobic groups include alkyl groups, either saturated or unsaturated, branched or unbranched, containing from about 8 to about 20, preferably from about 10 to about 16, carbon atoms. Preferably the alkyl group is a straight chain saturated alkyl group. The alkyl group can contain up to 3 hydroxy groups and/or the polyalkoxide chain can contain up to about 30, preferably less than 10 and most preferably 0, alkoxide moieties.

Suitable alkylpolysaccharides are decyl, dodecyl, tetradecyl, pentadecyl, hexadecyl and octadecyl, di-, tri-, tetra-, penta- and hexaglucosides, galactosides, lactosides, fructosides, frutcosyls, lactosyls, glucosyls and/or galactosyls, and mixtures thereof.

The alkyl monosaccharides are relatively less soluble in water than the higher alkylpolysaccharides. When used in admixture with alkylpolysaccharides, the alkylmonosaccharides are solubilized to some extent. The use of alkylmonosaccharides in admixture with alkylpolysaccharides is a preferred mode of

carrying out the invention. Suitable mixtures include coconut alkyl, di-, tri-, tetra- and pentaglucosides and tallow alkyl tetra-, penta- and hexaglucosides.

The preferred alkylpolysaccharides are alkylpolyglucosides having the formula:

R2θ (C _n H _2n O) r (Z) _x wherein Z is derived from glucose, R is a hydrophobic group selected from the group consisting of alkyl, alkylphenyl, hydroxyalkylphenyl, and mixtures thereof in which said alkyl groups contain from about 10 to about 18, preferably from 12 to 14 carbon atoms; n is 2 or 3, preferably 2; r is from 0 to about 10, preferably 0; and x is from 1.5 to about 8, preferably from 1.5 to 4 and most preferably from 1.6 to 2.7. To prepare these compounds a long-chain alcohol (R ² OH) can be reacted with glucose in the presence of an acid catalyst to form the desired glucoside. Alternatively the alkylpolyglucosides can be prepared by a two-step procedure in which a short-chain alcohol (R1 OH) can be reacted with glucose in the presence of an acid catalyst to form the desired glucoside. Alternatively the alkylpolyglucosides can be prepared by a two-step procedure in which a short-chain alcohol (C1-6) is reacted with glucose or a polyglucoside (x = 2 to 4) to yield a short-chain alkyl glucoside (x = 1 to 4) which can in turn be reacted with a longer chain alcohol (R ² OH) to displace the short-chain alcohol and obtain the desired alkylpolyglucoside. If this two-step procedure is used, the short-chain alkylglucoside content of the final alkylpolyglucoside material should be less than 50%, preferably less than 10%, more preferably less than 5% and most preferably 0%, of the alkylpolyglucoside.

The amount of unreacted alcohol (the free fatty alcohol content) in the desired alkylpolysaccharide surfactant is preferably less than about 2%, more preferably less than about 0.5% by weight, of the total alkylpolysaccharide. For some uses it is desirable to have the alkylmonosaccharide content less than about 10%.

The term used herein, "alkylpolysaccharide surfactant," is intended to represent both the preferred glucose and galactose derived surfactants and the less preferred alkylpolysaccharide surfactants. Throughout this specification, alkylpolyglucoside" is

used to include alkylpolyglycosides because the stereo chemistry of the saccharide moiety is changed during the preparation reaction.

An especially preferred APG glycoside surfactant is APG 625 glycoside manufactured by the Henkel Corp., Ambler, PA. APG 625 is a nonionic alkylpolyglycoside characterized by the formula:

C _n H2n+l O (C6Hi oθ5) χH wherein n = 10 (2%); n = 12 (65%); n = 14 (21 -28%); n = 16 (4-8%); and n = 18 (0.5%); and x (degree of polymerization) = 1.6. APG 625 has a pH of 6-8 (10% of APG 625 in distilled water); a specific gravity at 25°C of 1.1 grams/ml; a density at 25°C of 9 lbs/gallon; a calculated HLB of about 12.1 ; and a Brookfield viscosity at 35°C, 21 spindle, 5-10 rpm of about 3000 to about 7000 cps. Mixtures of two or more of the liquid nonionic surfactants can be used and in some cases advantages can be obtained by the use of such mixtures.

Other nonionic surfactants envisioned within the scope of the instant invention are, stearate or isostearate surfactants containing glycerol or sorbitan moieties, sulfosuccinates, nonionic surfactants based on Guerbet alcohols, and polymeric surfactants with polycarboxylic backbones.

A preferred nonionic surfactant of the instant invention is characterized by the formula: CH3 - (CH2)n - O - (CH2 - CH2 - O) _m H wherein n is 8 to 17 and m is 5 to 10, wherein m is equal to 5 to 8 is preferred.

Other preferred nonionic surfactants are characterized by the formulas:

CH3

I . R - O - (CH2 - CH2 - 0) _a - (CH2 - CH - 0)b - H

CH3

I R" - O - (CH2 - CH2 - 0) _c - (CH2 - CH - 0)d - (CH2 - CH2 - 0) _e - H CH3 CH3

I I

R'" - O - (CH2 - CH1 - 0)f - (CH2 - CH2 - 0)g - (CH2 - CH1 - 0)h - H wherein R' is an aliphatic hydrocarbon chain having about 8 to about 17 carbon atoms, R" is an aliphatic hydrocarbon chain having about 8 to about 17 carbon atoms, R"' is an aliphatic hydrocarbon chain having about 8 to about 17 carbon atoms, a is about 20 to about 100 mole %, b = 100-a, c + e is about 20 to about 100 mole %, d = 100 - (c + e), f + h is about 0 to about 80 mole %, and g = 100 - (f + h).

The organic hydrocarbon solvent component of the present microemulsion compositions includes solvents for the soils, is lipophilic, and is a suitable oil such as a polar oil or more preferably a non-polar oil which is preferably an aliphatic hydrocarbon of 9 to 18 carbon atoms and has the formula CnH2n+2, wherein n is 9 to 18 more preferably 10 to 16. Such an aliphatic hydrocarbon is desirably a normal paraffin or an isoparaffin and of these, those which are saturated and of 9 to 16 carbon atoms are preferred, with isoparaffins of 10 to 14 carbon atoms being also preferred. The most preferred aliphatic hydrocarbon solvent is decane. The aliphatic hydrocarbon solvent has a Hildebrand dispersion solubility parameter at 25°C of at least about 14.8, more preferably at least about 15.8.

The essentially nonaqueous polar solvents used in the formation of the microemulsion compositions have a Hildebrand dispersion solubility parameter at 25°C of at least about 16.0 and more preferably at least about 10.8. The polar nonaqueous solvent also has a Hildebrand hydrogen bonding solubility parameter at 25°C of at least 12.3 and more preferably at least 15.1. Typical nonaqueous polar solvents are diethylene glycol, triethylene glycol, glycerol, ethylene glycol, propylene

glycol, polyethylene glycol 300, and ethanol amine, and mixtures thereof, wherein ethylene glycol is a preferred polar solvent.

An essentially polar co-solvent having a Hildebrand dispersion solubility parameter at 25°C of at least about 16.0 and a Hildebrand hydrogen bonding solubility parameter at 25°C of at least 15.4 can be used to expand the microemulsion composition range on the polar solvent/nonionic surfactant/hydrocarbon phase diagram by the modification of the liphobocity of the nonaqueous polar solvent by the more or less polar co-solvent. A preferred nonaqueous polar co-solvent is glycerol. In addition to the recited components of the microemulsion compositions of the present invention, there may also be present adjuvant materials for dental, dishwashing, laundering and other detergency applications, which materials may include: foam enhancing agents such as lauric or myristic acid diethanolamide; foam suppressing agents (when desired) such as silicones, higher fatty acids and higher fatty acid soaps; preservatives and antioxidants such as formalin and 2,6-ditert-butyl-p-cresol; pH adjusting agents such as sulfuric acid and sodium hydroxide; perfumes; colorants (dyes and pigments); and opacifying or pearlescing agents, if desired.

A lithium salt such as a lithium carbonate lithium sulfate or lithium halide such as lithium chloride can be present in the liquid crystal composition at a concentration of 0 to about 10 weight. %, more preferably 0.1 to 5%. The lithium salt has a kosmotropic effect on the nonaqueous polar solvent by functioning to order the structure of the nonaqueous polar solvent.

The microemulsion compositions can be used in forming cleaning compositions containing enzymes and/or bleachants such as fabric detergent compositions or automatic dishwashing compositions which can contain bleachants, at least one enzyme, a suitable phosphate or non-phosphate builder system. The automatic dishwashing composition formed from the microemulsion composition can contain alkali metal silicates, bleachants as well as any of the generic types of enzymes such as protease, amylase and lipase enzymes.

A typical detergent composition comprises:

Dobanol 45.8 17%

Decane 48%

Ethylene Glycol 33%

Protease Enzyme 1.0%

Amylase Enzyme 1.0%

The phase transformation which can occur between microemulsion and gels and solutions resulting from the use of the invention, and the variations in formulas of compositions within the invention which are in microemulsion state, are easily ascertainable and the invention is readily understood when reference is made to this specification, including the working examples thereof, taken in conjunction with the phase diagrams, (Figures 1-11 ). For example, Figure 1 is a phase diagram of Dobanol 91 -5, decane and ethylene glycol, which is composition A of Example I.

The liquid crystal compositions can be used in forming cleaning compositions containing enzymes and/or bleachants such as fabric detergent composition or automatic dishwashing compositions which can contain bleachants, at least one enzyme, a suitable phosphate or non phosphate builder system as described in U.S.S. No 07/353,712 which is hereby incorporated by reference. The automatic dishwashing composition formed form the liquid crystal composition can contain alkali metals silicates, bleachants as well as any of the generic types of enzymes such as protease, amylase and lipase enzymes.

A typical detergent composition comprises:

Alfol 1618-9EO 36.8%

Dodecane 9.2%

Ethylene glycol 43.7%

Protease slurry Maxacal 6.0%

Amylase Maxamyl 2.0%

Glycerol 2.3%

The variations in formulas of liquid crystal compositions within the invention are easily ascertainable and the invention is readily understood when reference is made to this specifications, including the working examples thereof, taken in conjunction with the phase diagrams (Figures 15-20). Figure 15 is a phase diagram of Alfol 1618- 9EO, dodecane and a mixture of 95% ethylene glycol - 5% glycerol, wherein area 13

designates the stable liquid crystal composition and area 15 designates unstable liquid crystal composition. For illustration the composition at point 23 marked by X on figure 15 comprises 20 weight percent of Alfol 1618-9EO, 60 weight percent of a mixture of 95% ethylene glycol - 5% glycerol and 20 weight percent of the decane. In the previous description of the components of the invented compositions and proportions thereof which may be operative, boundaries were drawn for preferred compositions within the invention but it will be evident that one seeking to manufacture the invented microemulsion compositions and will select proportions of components indicated by the phase diagrams for the particular compositions, so that the desired compositions will be within the microemulsion area. Similarly, the compositions selected could be such that upon contact with water and the lipophilic soil to be removed from a substrate, the microemulsion composition will be preferably first transformed into a gel and upon the future addition of water into a solution. For plotting of the phase diagrams and in experiments undertaken by the inventors to establish the formulas of the desired microemulsion compositions, many different compositions within the invention were made and were characterized.

To make the microemulsion compositions of the invention is relatively simple because they tend to form spontaneously with little need for the addition of energy to promote transformation of the microemulsion state. However, to promote uniformity of the composition, mixing will normally be undertaken and it has been found desirable, but not compulsory, to first mix the surfactants and polar solvent together, followed by admixing of the aliphatic hydrocarbon solvent component. It is not usually necessary to employ heat to melt the nonionic surfactant and most mixings are preferably carried out at about 20-25°C or higher. The gel concentrates, made from the microemulsion compositions, which may be made by dilution with water of the microemulsion, are also manufactured according to the same procedure.

To make the liquid crystalline compositions of the invention is relatively simple because they tend to form spontaneously with little need for the addition of energy to promote transformation to the liquid crystalline state. However, to promote uniformity

of the composition mixing will normally be undertaken and it has been found desirable first to, but not compulsory, mix the surfactants and polar solvent together followed by admixing of the hydrocarbon solvent component. It is usually necessary to employ heat to melt the nonionic surfactant when it is not under a liquid form at room temperature and most mixings are preferably carried out at about 20-25°C or higher. Pre-spotting and manual cleaning uses of the invented microemulsion or liquid crystal detergent compositions are uncomplicated, requiring no specific or atypical operations. Thus, such compositions may be employed in the same manner as other liquid pre-spotting and detergent compositions. Because the transformation to gel state from the microemulsion state by contact with water and absorption of lipophilic soil is spontaneous and occurs at room temperature (and even at colder temperatures) it is not necessary to heat the microemulsion compositions nor the substrate before application of the microemulsion detergent (or pre-spotting agent) to the surface to be cleaned. The invented microemulsion or liquid crystal compositions may be applied to such surfaces by pouring onto them, by application with a cloth or sponge, or by various other contacting means, but it is preferred to apply them depending on their viscosity in the form of a spray by spraying them onto the substrate from a hand or finger pressure operated sprayer or squeeze bottle. Such application may be applied onto hard surfaces such as dishes, walls or floors from which lipophilic (usually greasy or oily) soil is to be removed, or may be applied onto fabrics such as laundry which has previously been stained with lipophilic soils such as motor oil. The invented compositions may be used as detergents and as such may be employed in the same manner in which liquid detergents are normally utilized in dishwashing, floor and wall cleaning, and laundering but it is preferred that they be employed as pre-spotting agents too, in which applications they are found to be extremely useful in loosening the adhesions of lipophilic soils to substrates, thereby promoting much easier cleaning with application of more of the same invented detergent compositions or by applications of different commercial detergent compositions in liquid, bar or particulate forms. As was previously indicated, the

microemulsion compositions can spontaneously convert to gels upon contact with lipophilic soil and water, and such microemulsion formation effectively weakens the bond of the soil to the substrate. After it is in the gel state, the soil is readily transferred to aqueous washing or rinsing media by additional contact with water, which makes it very easily removable from the substrate. The absorption of the lipophilic soil by the microemulsion detergent composition is accompanied by a change in the nature of the composition. The gel state of the detergent is of a greater viscosity and adhesion than the microemulsion. Thus, when sprayed onto a surface such as a vertical wall, the present cleaning compositions adhere to it and do not run or drip excessively, thereby allowing the detergent to work on the lipophilic soil more effectively. When the transformation to gel form has taken place, a sign of it will be thickening of the product and less sagging of detergent from the original locus of application. The addition of further water to the gel converts the gels into a solution or turbid emulsion, thereby facilitating the removal of the detergent composition from the substrate by sponging, rinsing, etc. While the advantages of a thicker and more adhering microemulsion and/or gel detergent composition are more significant for wall cleaning than for dishwashing, floor cleaning or laundering, even in the cases of such horizontal surfaces or surfaces which can be maintained horizontal, the applied microemulsion detergent composition or gel form after contact with a minimum amount of water substantially remains at the locus of the lipophile and thereby is better able to perform its cleaning function.

When sprayed onto a surface, such as a vertical wall, the present liquid crystal cleaning compositions, adhere to it and do not run or drip excessively, thereby allowing the detergent to work on the lipophilic soil more effectively. The liquid crystal can be converted into a gel by the addition of water. When the transformation to gel form has taken place a sign of it will be thickening of the product and less sagging of product at the original locus of application. The addition of further water to the gel converts the gel into a microemulsion or emulsion and upon the addition of a significant amount of water a clear or turbid solution is achieved thereby facilitating the

removal of the composition from the substrate by sponging, rinsing, etc. While the advantages of a thicker and more adhering liquid crystal and/or gel detergent composition are more significant for wall cleaning than for dishwashing, floor cleaning or laundering, even in the cases of such horizontal surfaces or surfaces which can be maintained horizontal, the applied liquid crystal composition or gel form after contact with a minimum amount of water substantially remains at the locus of the application and thereby is better able to perform its cleaning function.

Detergent gels derived from this invented liquid crystal composition can also be used as liquid detergents for the dishwashing of various vessels like glasses, plates or dishes and other table or kitchen utensils - in automatic dishwashers.

They can also be used as liquid detergents for the washing of linen in automatic laundering machines.

In the above applications, the gel can be either placed in the appropriate dispenser or directly poured in the machine or applied on the pieces to be washed. Such liquid detergents can incorporate water sensitive adjustments like enzymes or bleach.

The following example illustrates but does not limit the invention. Unless otherwise indicated, all parts in these examples, in the specification and in the appended claims are by weight percent and all temperatures are in °C.

Example 1 The formulas A through K were prepared according to the following procedure:

A B C D E

Dobanol 91 -5 30 26.9

Dobanol 25-9 20

Dobanol 45-8 15 20

Sodium lauryl sulfate 5.2

Ethylene glycol 35 55 35 20 36.6

Decane 35 25 50 60 31.3

Viscosity at 1 sec ^-1 (Pa s) 0.024 0.05 0.03 0.03 0.05 0 2 4 0

Viscosity at 100 sec" ¹ (Pa s) 0.022 0.04 0.02 0.02 0.03 5 3 2 4

Figure No. 1 2 4 4

F G H 1 J K

Dobanol 23-6.5 19

Dobanol 25-7 17

Dobanol 45.8 20 25

Dobanol 23-3 25

Dobanol 23-5.5 35

Hexane 67

Hexadecane 15

Decane 37.5 32.5 64 64

Ethylene glycol 13 60 17 19

Propylene glycol 37.5

PEG 300 32.5

Viscosity at 1 sec ^"1 (Pa s) 0.010 0.08 0.02 0.02 0.01 0.01 3 2 3 5 4

Viscosity at 100 sec ^-1 (Pa s) 0.003 0.07 0.01 0.02 0,00 0.00 6 2 8 2 8 9

Figure No. 5 6 7 8 3 9

Compositions A through K were made by first forming with mixing at room temperature a solution of the Dobanol nonionic or SLS surfactant and the nonaqueous polar solvent. To this solution at room temperature was added with mixing the nonaqueous hydrocarbon solvent to form the microemulsions A through K. The apparent viscosity measurements were made at 25°C on a Cammed.

Example II The following example illustrates but does not limit the scope of the invention. Unless otherwise indicated, all parts in these examples, in the specification and in the appended claims are by weight percent and all temperatures are in °C. The formulas A-G were prepared according to the following procedure:

(1 ) When present in the composition, the additive (e.g. dextrose) or the cosolvent (e.g. glycerol) was first premixed with the polar solvent (e.g. ethylene glycol) in the appropriate proportions and under stirring.

(2) The surfactant (e.g. Alfol® 1618 9EO) was melted with heat and then added with mixing, in the appropriate proportion, to the polar solvent or to the above polar solvent-additive mixture.

(3) The oil is eventually added with mixing to the above premix. Since the order of addition is not compulsory to obtain the expected liquid crystalline structure, other sequences can be successfully used. The rheology measurements were made, unless otherwise indicated at 25°C and on a stress controlled Cammed rheometer. Δ B c D E F G

Alfol® 1618 9EO 10.0% 12.5% 15.0% 15.0% 22.5% 25.0% 40.0%

Dodecane 2.5% 2.5% 2.5% 2.5% 2.5% - 10.0% Tetradecane . . . . . 5.0%

Ethylene glycol 83.125% 80.750% 78.375% 80.025% 71.250% 70.000% 47.500% Glycerol 4.375% 4.250% 4.125% - 3.750% - 2.500% Dextrose _{: : :} 2.475% - _: -

_B_

G'(Pa) 15 - 209 283 23.5 65 5165

(1 Hz-25°C) (10Hz-20°C)(10Hz-20°C)(1 Hz-25°C (1 Hz-25°C) (10Hz20°C) G' (PA) 16 - 159 305.2 57 67 1409

(1 Hz-gg Q (1 QHz-gQgQf 1 QHz-gQ C-HI Hz-giftC (1 Hz-gS^C) (1 QHz2Q°-£)

Apparent viscosity 1.489 2.29 16.301 7.348 298.384

(Pa. sec) (20°C) 25°C, 0.01 sec ^"1

Apparent viscosity

(Pa. sec) 25°C, 100 sec ^"1 0.059 0.072 0.112 0.204 1.12 (20°α

The major benefits to use nonaqueous liquid crystal compositions are found in the following applications: liquid detergents incorporating water sensitive ingredients which remain stable under long periods of time; or liquid detergents with solid or insoluble particles which do not settle over long periods of time; or concentrated detergents which are pourable (aqueous concentrated detergents form gels and are not pourable) and which are easily dispensable or soluble in water and which can possibly form microemulsions after dilution in water; or waterless liquid crystal which adhere to vertical surfaces and are effective in neat or in diluted forms; or any combination of the above.

The various advantages of the invention have already been set forth in some detail and will not be repeated here. However, it will be reiterated that the invention relates to the important discovery that effective liquid detergent compositions can be made in the liquid crystal state and that because they are in such state they are especially effective in removing lipophilic soils from substrates and also are effective in removing from substrates non-lipophilic soils which are bound to the substrates by lipophilic materials. Such desirable properties of the liquid crystal detergent compositions of this invention make them ideal for use as pre-spotting agents and detergents for removing hard-to-remove soils from substrates in various hard and soft surface cleaning operations.

Especially important is the spontaneous conversion of the invented compositions

to the gel form during which conversion lipophilic soil is loosened and absorbed with the gel without the need for applications of significant amounts of energy, either in thermal or mechanical form. Thus, the invention is a significant one and represents an important technical advance in the art.

The invention has been described with respect to various embodiments and illustrations of it but is not to be considered as limited to these because it is evident that one of skill in the art with the present specification before him/her will be able to utilize substitutes and equivalents without departing from the invention.