IE57570B1 - Liquid detergents with solvent - Google Patents

Abstract

Liquid detergent compositions are prepared from conventional detersive surfactants and other conventional detergent ingredients plus a grease-cutting solvent. The compositions contain fatty acids or soaps as a detergency builder and are formulated as stable oil-in-water microemulsions.

Description

The present invention relates to compositions and processes for laundering fabrics which employ high levels of solvent to enhance the removal of greasy soils and stains. The liquid compositions herein are provided in the form of clear, or substantially clear, homogeneous, stable emulsions which not only provide excellent pretreatment cleaning performance, but also exhibit improved detergency and fabric whiteness maintenance when used in an aqueous laundry liquor. In addition to providing improved removal of greasy stains, such as motor oil, cosmetics, and the like, the compositions herein also are excellent for removing particulate soils from fabrics. The compositions are formulated and stabilized at a pH in the range near neutrality to alkaline.

Various organic solvents, including terpenes and terpene-like compounds, are rather well-known for use in hard surface cleaners for their grease removal ability.

Such cleaners often contain 10%, or more, of a solvent such as d-limonene, together with a surfactant, especially nonS .-: ionic surfactants which are also well-known for their grease removal performance.* Such compositions have also been suggested for cleaning carpets. GB-A-1,6O3,O47, 1981. EP-A-0 040 882 discloses hard surface cleaners comprising a mixture of benzyl alcohol, terpenes, surfactants and other detersive ingredients.

Citrus juices, which contain relatively low amounts of terpenes, have been suggested for use in hand soaps and dishwashing liquids. US-A-3,650,968, 1972; Memoire descriptif 873,051 (relating to Brevet Anglais 53472/77, 22 December 1977) .’· Terpineols, e.g. from pine oil, have been disclosed for use in wet-scouring of textiles. In particular, in 1937, US-A-2,073,464 disclosed clear compositions which can be prepared from pine oil terpineol such as alpha terpineol and fatty acid soap or free acid neutralized in situ to alkaline pH.

More recently, an article in Soap Perfumery Cosmetics April, 1983, pages 174,175 suggests that only low levels of terpenes (3%) can be incorporated into heavy duty liquid detergents.

EP-A-0 072 488 suggests that terpenes such as d-limonene can be incorporated into fabric pre-treating compositions as a non-homogeneous emulsion. Such emulsions are apparently designed to be packaged in relatively small volume containers which can be shaken immediately prior to use to restore some semblance of homogeneity, then dispensed directly onto fabrics by spraying.

Clear emulsions comprising water, surfactant and various other solvents are disclosed by Davidsohn in 3rd International Congress of Surface Activity, Cologne(1960).

The use of relatively high concentrations of solvents in heavy duty liquid laundry detergents offers many advantages. The liquid form of such products allows them to be used as pre-treatment agents. When used through-the-wash, solvents such as terpenes have now been found to provide additional cleaning benefits over and above those provided by detersive surfactants. Unfortunately, the non-homogeneity of compositions such as those disclosed in EP-A- 0 072 488 makes them inconvenient for use as a general purpose laundry detergent, since most heavy duty liquid detergents are packaged in relatively large containers which are unhandy for the user to shake thoroughly.

Moreover, lew (about 3%) of terpenes, «dene, in detergent compositions used in a through-the-wash mode give little in the way of additional cleaning benefits, since dilution by the wash liquor obviates their effect.

The present invention provides fully-formulated heavy duty liquid laundry detergents comprising as much as 20% by weight of essentially water-insoluble solvent, in the form of homogeneous, fatty acid-built liquids that are quite suitable for use in both the fabric pre**treatment and through-the-wash modes.

Importantly, means are disclosed which allow such compositions to be formulated as stable microemulsions at pH's of from 6.5 to 8.0.

The present invention provides a liquid detergent composition comprising an aqueous carrier, from 10% to 40% by weight of non-soap detersive surfactant, and from 5% to 20% by weight of grease-removal solvent comprising a non-polar solvent component selected from terpene and terpenoids, paraffins, halogenated hydrocarbons, c6"cg alkyl aromatics, liquid olefins and mixtures thereof, the composition also comprising from 5% to 30% by weight of Cio"cie fatty acid or soap thereof and a microemulsion stabilizer, the stabilizer being a water-soluble high ionic strength ingredient selected from formate, sulfate or citrate, an ingredient soluble in the non-polar solvent and having an HLB of from 2-5, a nitrogen-functional compound, or a mixture thereof, wherein the composition has a pH of from 6.5 to 8.0 and is in the form of a stable oil-in-water microemulsion.

S The essential solvent, fatty acid (or soap) and water emulsification system, the detersive surfactant components, the means for stabilizing the formulations at pH's from 6.5 to 8.0 and various other optional ingredients used in the practice of the present invention are described in more detail, hereinafter. All percentages and ratios mentioned in this specification are by weight, unless otherwise stated.

Solvent - The solvents employed herein can he any of the well known degreasing solvents commonly known for use in, for example, the commercial laundry and drycleaning industry, in the hard-surface cleaner industry and the metalworking industry. Typically, such solvents comprise hydrocarbon or halogenated hydrocarbon moieties of the alkyl or cycloalkyl type, and have a boiling point well above room temperature .

The formulator of compositions of the present type will be guided in the selection of solvent partly by the need to provide good grease-cutting properties, and partly by aesthetic considerations. For example, kerosene hydrocarbons function quite well in the present compositions, but can be malodorous. Kerosene can be used in commercial laundries. For home use, where malodors would not be tolerated, the formulator would be more likely to select solvents which have a relatively pleasant odor, or odors which can be reasonably modified by perfuming. Such solvents include, for example, the terpenes and terpenoid solvents obtainable from citrus fruits, especially orange terpenes and d-limonene. Benzyl alcohol is another relatively pleasant smelling solvent for use herein. Mixtures of orange terpene and benzyl alcohol are especially suitable for removing certain types of stains, e.g., marker ink, shoe polish, and dirty motor oil.

Excellent solvents for use herein are the paraffins and the mono- and bicyclic mono-terpenes, i.e., those of the hydrocarbon class, which include, for example, the terpinenes, limonenes and pinenes, and mixtures thereof. Highly preferred materials of this latter type are d-limonene and the mixture of terpene hydrocarbons obtained from the essence of oranges (e.g. cold-pressed orange terpenes and orange terpene oil phase ex fruit juice). Also useful are, for example, terpenes such-as dipentene, alpha-pinene, beta-pinene and the mixture of terpene hydrocarbons expressed from lemons and grapefruit.

Various other solvents and, especially, preferred mixtures of non-polar and polar solvents, vrfiich can be used in the present ocmpositions are disclosed hereinafter.

Fatty Acids and Soaps - Fatty acids such as lauric, myristic, palmitic, stearic and oleic acids, and poly-unsaturated fatty acids, as well as their water-soluble salts (i.e., soaps) are employed in the present compositions to provide clear, homogeneous formulations containing the solvent and water. Mixtures of fatty acids (or soaps) including palm oil acids, coconut oil acids, and the like, in the C12-C18 carbon chain length, can be used. In general, the concentration of fatty acid (or soap) is from 5% to 30%, and the weight ratio of fatty acid (or soap): solvent is in the range of 4:1 to 1:4, more preferably 3:1 to 1:2. -When using fatty soap, the potassium and sodium salt forms are preferred, but any convenient water-soluble salt may be used.

Apart from their function as microemulsion stabilizers, these fatty acid/soap materials provide an important detergency builder function in the present compositions. However, it has now been discovered that when formulating oil-in-water microemulsion compositions at a pH greater than about 6.5, the presence of fatty acid/soap can actually destabilize the system. Means for overcoming this de-stabilization while maintaining a pH of 6.5 or above in microemulsions containing builder levels of fatty acid/soap are disclosed in detail, hereinafter.

Water - The compositions herein may properly be characterized as water-based, in contrast with organic solvent-based cleaners known in the art.

Surprisingly, water can interfere with the ability of solvents such as terpenes to remove greasy stains from fabrics. For example, a fabric stained with motor oil and dampened with water prior to treatment with neat terpene is not very well de-greased by the terpene, if at all. By contrast, the present compositions wherein non-polar solvent such as the terpenes are microemulsified in water aze excellent greasy stain removers when used directly cn dry or damp fabrix^.

Apart from water's obvious environmental and safety pedigrees and low cost as opposed to organic solvents, water-based heavy duty liquid detergents offer ease-of-formulation advantages with respect to ingredients such as most detergency builders, sanitizers, chelants, soil-suspending agents, pH-control agents, and the like, which are usually water-soluble.

Accordingly, the compositions herein exhibit the advantages of water-based formulation flexibility, together with the superior grease removal qualities of solvent-based compositions.

As will be described more fully hereinafter, the present compositions generally comprise from 10% to 70%, preferably 20% to 50% water. The weight ratio of waterssolvent is generally 10sl to ltl, preferably 5;1 to 2:1.

PH/Stabilizer - As is well-known in the detergency arts, it is preferred for detergent compositions to be in the nearneutral to alkaline pH range, i.e., pH 6.5, and above. This is for a variety of reasons. For example, many soils are partly peptized or emulsified by alkalinity, itself. And, many commercially available detersive enzymes (e.g., the alkaline proteases) function optimally in alkaline laundering liquors.

It has now been discovered that stable oil-in-water microemulsion detergent compositions which comprise builder levels of fatty acid/soap are de-stabilized when their pH is adjusted to about 6.5, and above. (The pH where instability is noted may vary slightly with the actual grease-cutting solvent used in the microanulsion, its level, and the chain length and degree of Unsaturation of the fatty acid.) This problem is especially acute with substantially non-polar, hydrocarbon grease-cutting solvents,e.q., orange terpenes and paraffin oils.

The stability problem seems to arise by virtue of the fatty acid, which has an HLB of approximately 2, being converted almost entirely to soap, with an HLB of about 20, over a very narrow pH range, roughly 6.5-6.9. Thus, since . the fatty acid is present in substantial amounts (ca. 5%, and higher) this major shift in HLB upsets the HLB of the emulsification system and results In de-stabilization.

It is to be understood that formulation stability could theoretically be achieved by proper selection of surfactants (discussed hereinafter) with low HLB's. For example, nonionic surfactants such as Cl4-15 alcohols with low ethoxylate numbers (1-3) could be used. However, such low HLB surfactants do not function well as detersive surfactants, and the object herein is not only to provide stable mioroenulsions, but also good pre-treat and through-the-wash detergency.

It has now been found that by either increasing the ionic strength of the aqueous phase, or by adding solventsoluble ingredients with low HLB’s, which increase solvent polarity, to the solvent phase, oar by using both means conjointly, the ndcroenulsion is stabilized In particular, adding water-soluble, high ionic strength ingredients such as, for example, formate, sulfate, citrate. and the like, increases stability. By contrast, adding water-soluble, low ionic strength materials such as ethanol has no stabilizing effect.

Also, adding slightly polar ingredients with low HLB's that dissolve in the non-polar solvent, such as n-hexanol, benzyl alcohol, mixed fatty alcohols and the like, increases stability.

Conjointly adding the ionic strength ingredients and the solvent-soluble ingredients further enhances stability.

Of course, the formulator can select ingredients with a view towards not only increasing microemulaion stability, but also providing optimal cleaning benefits. For example, one. can choose citrate as an ionic strength agent which also has detergency builder properties, formate as an ionic strength agent which also stabilizes detergent enzymes, and n-hexanol or benzyl alcohol as a -low HLB ingredient which also serves a useful grease-cutting function.

The amount of ionic strength or low e.g. (2-5) HLB solventsoluble ingredients, or both, used in the compositions will depend somewhat on the pH desired, the concentration of fatty acid, the level of grease-cutting solvent, the composition of the detersive surfactant system, and the like. Microemulsion stability can be monitored rather simply since the true microemulsions are clear, but turn hazy and non-homogeneous, with eventual phase separation at the point of instability.

With regard to pH adjustments in the compositions, any of the well-known base materials can be used to adjust pH to about 6.5-6.6; for example, triethanolamine, alkali metal hydroxide and the like. Potassium hydroxide is preferred over sodium hydroxide, inarasirh as the ease of formulation of stable systems is increased substantially by the potassium cation.

Magnesium hydroxide is another useful neutralizing base. During use, the magnesium cation is believed to associate with anionic surfactants present in the compositions to enhance their grease-removal performance.

The preferred use of various amines, amine oxides and quaternary ammonium compounds (i.e.,nitrogen-functional compounds) to adjust the pH above 6.5-6.6 and further help stabilize the miczoonulsions is described in more detail, hereinafter.

Detersive Surfactants - The compositions of this invention will typically contain organic surface-active agents (surfactants) to provide the usual cleaning benefits associated with the use of such materials.

Detersive surfactants useful herein include well-known synthetic anionic, nonionic, amphoteric and zwitterionic surfactants. Typical of these are the alkyl benzene sulfonates, alkyl-and alkylether sulfates, paraffin sulfonates, olefin sulfonates, alkoxylated (especially ethoxylated) al10 cohols and alkyl'phenols, amine oxides, Ot-sulfonates of fatty acids and of fatty acid esters, and the like, which are well-known from the detergency art. In general, such detersive surfactants contain an alkyl group in the cg"cjg range; the anionic detersive surfactants can be used in the form of their sodium, potassium or triethanolammonium salts but it is to be understood that the presence of magnesium cations in the compositions usually means that at least some portion of the anionic surfactant will be in the magnesium salt form; the nonionics generally contain from 5 to 17 ethylene oxide groups. US-A-4.111.8551 and US-A3.995.669 contain detailed listings of such typical detersive surfactants. cx1**cig alkyl benzene sulfonates, Cjj-C^g paraffin-sulfonates and alkyl sulfates, and the ethoxylated alcohols and alkyl phenols are especially preferred in the compositions of the present type.

Mixtures of the ethoxylated nonionics with anionics such as the alkyl benzene sulfonates, alkyl sulfates and paraffin sulfonates are preferred for through-the-wash cleansing of a broad spectrum of soils and stains from fabrics.

Such surfactants and mixes typically have HLB's of 20 and above. ii jf -:.

Polyamines - Polyamine materials are optional ingredients in the present compositions by virtue of their ability to co-act with the solvent to remove the solid material that is present in many greasy stains (e.g., carbon black in motor oil stain; day and color bodies in cosmetic stain). It is to be understood that the term polyamines as used herein represents generically the alkoxylated polyamines, both in their amine form and in their quaternarized form. Such materials can conveniently be represented as molecules comprising at least 2, preferably from 2-20, most preferably 3-5 recurring units having the formula: N — R -)- Amine form I alkoxy and R -(- — R -)- jP I alkoxy Quaternarized form wherein R is a hydrocarbyl group, usually of 2-6 carbon atoms; R may be a Cj-C2q hydrocarbon; the alkoxy groups are polyethoxy, polypropoxy, and the like, with polyethoxy having a degree of polymerization of 2-30, moat preferably A to 20; and X is an anion such as halide or methylsulfate, resulting from.the quaternization reaction. The anion xP is of no particular consequence to performance of the polyamine in the present context, and is mentioned only for completeness in the above, formula.

The most highly preferred polyamines for use herein are the so-called ethoxylated polyethylene imines, i.e., the polymerized reaction product of ethylene oxide with ethylene imine, having from 3 to’5 recurring units of the formula: 4-N-CH--CH, 4I (CH2CH2O)y wherein y is an integer of 10 to 20.

Polyamines typically will comprise at least 0.2% of the preferred compositions herein, generally 0.5%-5%.

Other Optional Ingredients - The compositions herein can contain other ingredients which aid in their cleaning performance. For example, it is highly preferred that throughthe-wash detergent compositions contain a detergent builder and/or metal ion sequestrant. Compounds classifiable and well-known in the art as detergent builders include the nitrilotriacetates, polycarboxylates., citrates, watersoluble phosphates such as tri-polyphosphate and sodium ortho- and pyro-phosphates, silicates, and mixtures thereof. Metal ion sequestrants include all of the above, plus materials like ethylenediaminetetraacetate, the amino-polyphosphonates and phosphates (DEQUEST*)and a wide variety of other poly-functional organic acids and salts too numerous to mention in detail here. See US-A-3.579.454 for typical examples of the use of such materials in various cleaning compositions. In general, the builder/sequestrant .) will comprise 0.5% to 15% of the composition. Citrate is one of the most preferred builders since it is readily soluble in the aqueous phase of heavy-duty liquid detergent compositions. Such ingredients are also useful in hardsurface cleaners.

A source of magnesium ions can be used in the compositions, for the reasons stated hereinabove. Besides magnesium hydroxide, water-soluble salts such as magnesium chloride, acetate, sulfate, and the like, can be used.

The laundry compositions herein also preferably contain enzymes to enhance their through-the-wash cleaning performance on a variety of soils and stains. Amylase and protease enzymes suitable for use in detergents are well-known *Trade Mark in the art and in commercially available liquid and granular detergents. Commercial detersive enzymes (preferably a mixture of amylase and protease) are typically used at levels of 0.001% to 2%, and higher, in the present compositions. Ingredients such as propane diol and/or formate and calcium can be added to help stabilize the enzymes in well-known fashion, according to the desires of the formulator.

Moreover, the compositions herein can contain, in addition to ingredients already mentioned, various other optional ingredients typically used in commercial products to provide aesthetic or additional product performance benefits.

Typical ingredients include -perfumes, dyes, optical brighteners, soil suspending agents, hydrotropes and gel-control agents, freeze-thaw stabilizers, bactericides, preservatives, suds control agents and the like at levels of 0.1-15%.

Water or water-alcohol (e.g., ethanol, isopropanol, etc.) mixtures are used as the carrier vehicle, and alkylated polysaccharides can be used to increase the stability and performance characteristics of the compositions.

The compositions herein are in liquid form, which can be prepared by simply blending the essential and optional ingredients in the aqueous carrier. Microemulsion stability can be estimated visually by watching for phase separation, or can be monitored more quantitatively by standard turbidometric techniques.

In one process aspect, the compositions can be used to pre-treat soiled fabrics by rubbing a few milliliters of the composition directly onto and into the soiled area, followed by laundering, in standard fashion. In a throughthe-wash mode, the compositions are typically used at a concentration of at least 500 ppm, preferably 0.1% to 1.5% in an aqueous laundry bath at pH 6.5 and above to launder fabrics. The laundering can be carried out over the range from 5°C to the boil, with excellent results.

For use on hard surfaces, as rug cleaners, and as general-purpose cleaners, the compositions are diluted with water, or used full-strength, all in standard fashion.

The following examples describe a variety of formulations which can be prepared in the manner of the present invention. The examples are given by way of illustration and are not intended to be limiting of the scope of the invention, in the polyamine-containing formulations listed, the terms x and "y" are stated in parentheses to designate the degree of polymerization and degree of alkoxylation of the polyamine.

I For some polyamines, the designation R is also included, thereby denoting a guaternarized polyamine. For such auaternarized materials, the resulting anion X~ is of no consequence to cleaning performance, and is not designated.

Heavy-Duty Liquid Detergents Special attention is directed to highly preferred formulations which are particularly useful as heavy duty liquid detergents that are suitable for laundering all manner of fabrics in a typical home laundering operation.

The heavy duty liquid detergents disclosed hereinafter are formulated with a variety of detersive ingredients to provide excellent cleaning of a wide variety soils and stains, with particularly noteworthy benefits with regard to cosmetic and dirty motor oil stains.

It is to be understood that the following formulations are in the form of oil-in-water emulsions (wherein the solvent is considered the oil1* phase) and'are substantially clear, homogeneous, stable microemulsions. Surprisingly, when used in a pre-treatment mode, the oil-in-water microemulsions herein are comparable in grease-cutting performance to water-in-oil emulsions, which have much higher concentrations of solvent. The compositions also exhibit excellent whiteness maintenance on cotton fabrics, apparently because the solvent reduces fatty acid soap build-up on fabric surfaces. These performance advantages are particularly noticeable after multi-cycle washings.

INGREDIENT EXAMPLE I PARTS BY WEIGHT Ethanol 3.0 Potassium hydroxide (50% in water) 10.0 Alkyl (C^ θ) benzene sulphonic acid 11.0 Alkyl (C14/15) ethoxylate (E07) Potassium citrate monhydrate (63,5% in 15.0 water) 4.8 Dequest* 2060 S (Trade Mark) 1.2 Sodium formate (40% in water) 2.5 Ca++ as CaCl2 6H20 60 ppm Orange Terpenes 10.0 Laurie / myristic acid (60/40) 12.54 Oleic acid 2.5 $8B Maxatase (Trade Mark) enzyme 0.71 . sss Termamyl (Trade Mark) enzyme 0.10 FWA 0.23 Perfume 0.5 Dye 20 ppm Water to 100 Product pH 7.5 * Diethylene triamine pentamethylene phosphonic add (Monsanto) SS KNGS, supplier SSS NOVO, supplier The above composition is prepared by blending the indicated ingredients to provide a clear, stable microemulsion. In laundry tests, particularly with a pre-treatment step, the composition gives excellent performance on a wide variety of stains, especially cosmetics and dirty motor oil.

EXAMPLE II The composition of Example I is modified slightly by using 0.6 parts by weight of magnesium hydroxide as replacement for 2 parts of the 50 % KOH and adjusting pH to 7.5 . The resulting product is a clear, stable, homogeneous microemulsion.

EXAMPLE III The composition of Example I and II are each modified by the addition of 1.5 parts by weight of tetraethylene pentamine ethoxylated with an average of 15 moles of ethylene oxide per nitrogen atom. The resulting composition is a clear, stable, homogeneous microemulsion at pH's above 6.9.

As another example, any of the foregoing compositions may be modified by replacing the orange terpene solvent by a mixture of deodorized paraffin oil(iso-C|Q-Cj2»7.5% of the total catpositicn) and orange terpenes (2.5 t of total composition. This change in the solvent component in no way detracts from the performance attributes of the compositions, but allows the perfumer more latitude for introducing non-citrus perfume notes. Anionic 2o optical brightener (0.01-0.5 %) may be added, as desired.

SOLVENT SELECTION As disclosed hereinabove, final selection of the solvent system for use in the present compositions will be dependent upon soil type and load, aesthetics (odour) etc. However, a number of criteria can be used to guide this selection.

For example, the solvent should be substantially water immiscible; and, it should of course be capable of solubilizing a broad range of problem greasy soils. In this latter respect thermodynamic solubility parameters (Hansen Parameters) are useful in making the solvent selection.

Any solvent can be described by the Hansen Parameters Ed' <5p' Jh! the dispersion component; the polarity component; and <5^ the hydrogen bonding component. Likerwise, key greasy problem soils can be described by pseudo Hansen Parameters. In order to do this the solubility of each greasy stain in a broad range of solvents of different Hansen Parameters is first assessed. This can be done by immersing the greasy stain on a range of different fabric types (cotton, polyester cotton, acrylic) in each solvent in turn for a fixed time (say, 5 minutes) under fixed agitation. On removal, excess solvent is drained-off and the stained fabric is washed for 5 minutes in cool water containing 1% concentration of a typical liquid laundry detergent. Following final rinsing in cold water and drying, the stain removal can be assessed visually or by any other suitable technique.

By proceeding in this way, those solvents giving best removal of each problem greasy stain can be identified, and thereby the range of each Hansen Parameter required for optimum removal of that particular stain can be assessed. Thus, for each stain a map of Hansen Parameters can be developed, and solvent/solvent combinations can be selected on this basis to give the target performance profile.

Although not intended to be limiting of the present invention, the above technique indicates that solvent/solvent compositions with Hansen Parameters in the IS range δ^ (14*3 to 18.4 (J/cm3)^/2=7 to 9 (cal/cm3) ^2], 6h[0 to 14.3(J/cm3)1/2=0 to 7 (cal/cm3)1/2], δρ[0 to 8.2 (J/cm3) 1/<2=0 to 4 (cal/αη3), are key for formulating microeanulaions with superior greasy stain removal performance. The solvent combination can be targeted against particular greasy stains, such as motor oil, where the optimum Hansen Parameter range is 6^(14.3 to 18.4 (J/cm3) ^^=7 to 9 (cal/cm3)ly/2], 6h [0 to 8.2 (J/cm3) ^=0 to 4 (cal/cm3)1/2], δ [0 to 6.1 (J/cm3)1/2=0 to 3 (cal/cm3)1/2 or marker P 3 i/2 ink, where the optimum range is δ^ [14.3 to 18.4 (J/cm ) =7 to 9 (cal/cm3)1/2], [4.1 to 22.5 (J/cm3)1/2=2 to 11 (cal/cm3)1/2], δ [4.1 to 14.3 (J/cm3) 1/2=2 to 7 (cal/cm3)1/2), A. or targeted more broadly against mixed stains by selecting an intermediate point in the range of Hansen Parameters.

Preferred solvents and solvent mixtures herein, especially: orange terpenes (d-limonene),paraff ins (especially iso-C^Q-C^);cyclohexane; kerosene; orange terpene/benzyl alcohol; (60/40), n-paraffins (C12_15) /hexanol (50/50) fall within the Hansen Parameters, as stated.

Any of the foregoing examples may be modified by replacing the solvents listed with the foregoing, especially by mixtures of terpenes or paraffin oil with benzyl alcohol» n-hexanol or 1-butanol. Preferred pH's for the heavy-duty detergents are 6.6-7.3. Product as is" pH is measured at ambient (23°C) temperature using a commercial pH meter.

The electrode is immersed in the product and. the meter is allowed to stabilize before reading.

The following examples relate to compositions within the scope of this invention with solvents that are particularly suitable in industrial, heavy-duty laundry and cleaning plants, and the like. It will be appreciated by 5 the formulator that some of the solvents employed in such compositions may be unsuitable for general home use, due to malodors, potential for skin irritation, low flash points, and the like. However, such compositions are entirely suitable for use under properly controlled conditions by pro10 fessional operators who take such matters into consideration.

In Examples IV-VIII, the pH is adjusted in all compositions with magnesium hydroxide, as indicated. All the other ingredients are listed as parts by weight. aiGBEBSNT TV V VI VII vm 15 Stoddard solvent 100 - - - Trichloroethylene - 10 - - - Naphtha - - 30 - - Petroleum Ether (b.p. 80-85°C) - - - GO 100 Mineral spirits - - - 20 'M 20 Benzyl alcohol - - - - 100 Butyl carbitol (T.M.) - - - - - Folyanine (A-E**) 5(A) 10(B) 15(C) 100(D) 20(E) Water 100 100 200 100 250 Coconut fatty acids 20 20 25 60 100 25 Cl2 alkyl benzene sulfonic acid 50 5 - - 10 C., . c alcohol ethoxylate (EQAvg 9, 50 - — - - Cq alkyl phenol (ethoxylated BO ftvg 6) — 2 10 100 10 30 Mg (OH) 2to pH shown 7.0 7.1 7.5 - 7.7 * Polyamines A-F used in Exanples IV-1 VIII have the general formulae disclosed hereinbefore and are as follows: ΙΜ ισ in ice ι> x = 2;y = 2;R = ethylene ; alkoxy = ethoxy x = 20;y = 30;R = propylene ; alkoxy = propoxy x = 3;y = 15;R = ethylene ; alkoxy = ethoxy ; R' = butyl x = 5;y = 9;R = butylene ; alkoxy = butoxy x = 20; y = 10; R = hexylene ; alkoxy = ethoxy; R' ; dodecyl As can be seen from the foregoing, the present invention encompasses a variety of formulations’in the form of stable, solvent-containing emulsions. A superior heavy duty liquid detergent composition can also be prepared using a solvent system comprising diethyl phthalate (preferred) or dibutyl phthalate in combination with the terpenes (preferably, orange terpene) or dipentene, or paraffin oils, or (most preferably) mixtures thereof. The following is a representative example of svich a composition.

EXAMPLE IX Ingredient Polyamine <χ=5;γ=1.5) Potassium Hydroxide (50 % Aq.) Ethanol C11 8 Benzene Sulphonic Acid C14/15 Ethoxylate (EO 7) Potassium Citrate (63.5 Aq.) Deodorized Paraffin Oil (iso-Cj^g) Orange Terpene Dibutyl phthalate Lauric/Myristic Acids (60/40) Enzymes (per Ex. X) Water and minors with pH adjusted with Mg (OH)., to 7.3 1 Parts by weight 1.5 8.0 3.0 11.0 .0 2.4 7.5 2.5 3.0 12.5 1.0 to 100 In Example IX, an equivalent the dibutyl phth&late can be replaced by amount of diethyl phthalate.

It will be appreciated that many of the foregoing compositions comprising the terpene hydrocarbons will necessarily have a rather strong citrus odor that may not be entirely acceptable to all formulators of such compositions. It has now been> discovered that the Cg-Cg alkyl aromatic solvents, especially the Cg-Cg alkyl benzenes, preferably octyl benzene, exhibit excellent grease-removal properties and have a low, pleasant odor. Likewise, the olefin solvents having a boiling point of at least about ICO’C, especially alpha-olefins, preferably 1-decene or 1-dodecene, are excellent grease-removal solvents. Also, the iso-paraffins (especially C10~C12 chain lengths) are noteworthy for their low odor and high grease-removal characteristics. lhe combination of the aforesaid alkyl-aromatic or paraffin or olefin solvents with polar liquids such as benzyl alcohol, n-hexanol, Butyl Carbitol (Trade Mark; 2-(2-butoxyethoxy) ethanol) or the phthalic acid esters constitute additional examples of preferred non-polar/polar solvents that are preferred for use in the practice of this invention.

The following additional examples further illustrate oil-in-water microemulsions. In Example XIII, the use of the quaternary ammonium compound to adjust the pH of the formulation to a pH just barely below neutrality contributes importantly to product performance while maintaining longterm microemulsion stability.

I I EXAMPLE X Ingredient % By WeightC11 8 ^lkyl benzene sulphonic acid 10.0C14/15 ethoxYlate (EO 7) 10.9 Coconut fatty acid (broad cut) 18.2 Oleic acid 2.3 Monomethyl ethanolamine 5.8 1-Decene 9.1 Ethanol (95%) 2.7 Dequest (50%)1 1,09 Formic acid Q.18 Kj citrate . HjO (63.5% in HjO) 4.4 CaClj . 2H2© 0.05 Maxatase enzyme (.protease) 0.73 Termamyl enzyme (amylase) 0.10 Ethoxylated polyamine 1.73 Perfume/optional brightener/dye 0.5 Water Balance Product pH 6.6 1. Diethylene triamine pentamethylenephosphonic acid 2. Tetraethylene pentamine 105 EO units/molecule The composition of Example X is a stable, oil-inwater 'microemulsion suitable for use as a laundry detergent.

EXAMPLE XI The composition of Example X. is modified by replacing the 1-Decene by the same amount (9.1% total formulation) of n-octyl henzene, Product pH as is : 6.6.

EXAMPLE XII The composition of Example. X is modified by replacing the 1-Decene by any of the following solvent mixtures (percentages of total formulation being specified in parentheses): 1-Decene (6.1%,/Diethylphthalate (3.0%); 1-Dodecene (7.3%)/ Benzyl alcohol (1.8%); n-octyl benzene (6.2%)/Diethyl phthalate (2.9%); n-octyl benzene (6.Q%)/ Butyl carbitol (3.1%). Product pH's as is : 6,6, EXAMPLE XIII The compositions of Examples X, XI, and XII are modified by adding sufficient dioctyldimethyl ammonium chloride to adjust the as is pH of the compositions from 6.6 to 6.94. The resulting compositions exhibit exceptionally good fabric cleaning and whiteness maintenance.

It is to be understood that the preferred compositions of Examples X-XIII are in the form of true oil-in-water microemulsions. On diluting with water, the compositions appear hazy. In contrast, water-in-o±l emulsions tend to gel on dilution, whereas micellar oil-in-water compositions remain clear on dilution.

Example xm illustrates the use of a nitrogen-functional ingredient (the quaternary) to adjust product pH. Other such pH adjusting agent? include the following (product pH being indicated in parentheses): coconutalkyldiethanol amine (6,65); coconutdimethyl amine (6.75); trioctylamine (7,0); cyclohexylamine (7,5); cpconutalkyl trimethylammonium chloride (6,66); coconutalkyX dimethylamine oxide (6.70); dicoconutalkyl dimethylammonium chloride (6,84); coconutalkyl benzyl dimethylammonlum chloride (6,84); dihexyl dimethylammonium chloride (.6,89); and dioctyl methyl amine oxide (>7 est.). Such nitrogen-functional material? are used at levels from 0.5-5% in the compositions to adjust pH. and importantly contribute to cleaning and whiteness maintenance of laundered fabrics. Cyclohexyl amine (1-5%) is preferred for. this use.

Another preferred olefin solvent herein by virtue of its relatively low odor is the so-called P-4 polymer, available from a number of petrochemical suppliers to the detergent industry as a raw material for branched alkyl t benzene. P-4 is an isomer mix of the condensation product of 4-moles of propylene, i.e.. C12 branched olefins.

P-4 is non-polar, and is preferably used in combination with a polar solvent such as benzyl alcohol, diethylphthalate. Butyl Carbitol, or the like.

Other useful polar solvents herein besides the Carbitols (2-(2-alkoxyethoxy)ethanols, include the Cellosolves (Trade Mark), e.g. 2-alkoxyl alkanols such as 2-butoxyethanol: c4-c12 alcohols, such as dodecanol. phenethyl alcohol, and the diglycolethec acetates, and the like.

EXAMPLE XIV A preferred composition by virtue of its low odor qualities and compatibility with polethylene containers is prepared by replacing the I-decene of Example Xi with a solvent mixture which comprises (as percent total composition) 6% diethylphthalate/2% iso-paraffin liquid (C10~Cj2)/2% orange terpene.

Importantly, all microemulsion compositions herein do not affect high density polyethylene and thus can be packaged in high density polyethylene bottles. In contrast, many solvent-containing cleaners that are not in true microemulsion form must be packaged in the more expensive metal cans or polyvinylchloride bottles.

EXAMPLE XV The following ace further examples of grease-removal solvent mixtures of polar and non-polar solvents for use herein.

Composition Ingredient Percent A Octyl benzene 70% Diethyl phthalate 30% B 1-Decene 70% Diethyl phthalate. 30% C Octyl benzene 80% Benzyl alcohol 20% D n-Octyl benzene 90% Butyl carbitol 10% E 1-Decene 65% Dibutyl phthalate 35% F n-Octyl benzene 30% 1-Decene 40% Benzyl alcohol 10% Butyl carbitol 20% G 1-Decene 80% n-Hexanol 20% H 1-Decene 60% Diethyl phthalate 40% I 1-Dodecene 80% Hexyl cellosolve 20% J Mixed 1:1 nonyl/hexyl benzene 35% 2-Dodecene 35% Dimethyl phthalate 30% In a preferred method of use aspect, the compositions are used in an aqueous laundering liquor ( preferably at a liquor pH of 6.5-8.0 measured as it of composition in water) to launder fabrics. Excellent cleaning is attained by agitating fabrics in such liquors at this in-use pH range.

EXAMPLE XVI A highly preferred liquid laundry detergent by virtue of the low odor properties of its grease removal solvent system, its stability in microemulsion form, and its enzymatic cleaning activity (by virtue of its pH) is as follows.

Ingredient Alkyl(C.. _)benzene sulfonic acid 11 Alkyl(C14/15)ethoxylate (E07) Topped whole cut coconut fatty acid (1) C10-ll ie°P«affins Diethyl phthalate Cyclohexylamine Monomethyl ethanolamine (2) Potassium citrate monohydrate (63.5% in water) Dequest 2060 S Ethoxylated polyamine (x=5, y»l5) Ethanol Potassium hydroxide (50% in water) (2) Formic acid CaCl2 2H2O Optical brightener (anionic) Maxataee enzyme (3) Termamyl 300L enzyme (4) Dye Perfume Mater Product pH Parts by Weiqht 11.0 12.0 .5 4.0 6.0 2.0 4.3 2.4 1.7 1.5 3.0 3.0 0.2 0.05 0.18 0.71 0.10 ppm 0.5 up to 110 parts 6.9 (1) Chain length mixture: Ciq(5%) Ci2(55%) Ci4<22%) C18(2%) oleic(10%) (2) To adjust pH to 6.6 (3) From KNGS (4) From NOVO The composition of Example XVI is used in an aqueous laundry bath at a concentration of 100mi/10 liters and provides an in-use pH of about 7,2 (varies with water hardness).

The most highly preferred cleaning solvent mixtures of paraffins, especially iso-C1Q 12 (most preferably iso-C^g) paraffin hydrocarbons and diethyl phthalate (or, less preferred, dibutyl phthalate) function exceptionally well in cleaning fabrics, both in a pre-treatment and through-the-wash mode. These particular solvents, formulated at a ratio of 5:1 to 1:5. are especially advantageous due to their exceptionally low odor. Mixtures of these solvents with cyclohexylamine (ratio solvent mix to cyclohexyl amine 10:1 to 1:10. preferably 5:1 to 2:1) provide homogeneous liquid compositions of the oil-in-water microemulsion type that are preferred for all manner of cleaning operations where greasy stain removal is a consideration.

Besides their excellent cleaning performance, the 20 microemulsion compositions of this invention are noteworthy for their mildness to skin. This unexpected benefit in solvent-containing compositions allows the compositions to be used in hand-washing of fine fabrics, china, glassware, and the like.

Claims (10)

CLAIMS:

1. A liquid detergent composition comprising an aqueous carrier, from 10% to 40% by weight of non-soap detersive surfactant, and from 5% to 20% by weight of grease-removal solvent comprising a non-polar solvent component selected from terpene and terpenoids, paraffins, halogenated hydrocarbons, c g“ c g alkyl aromatics, liquid olefins and mixtures thereof, the composition also comprising from 5% to 30% by weight of C 12 ~C 18 fatty acid or soap thereof and a microemulsion stabilizer, the stabilizer being a water-soluble high ionic strength ingredient selected from formate, sulfate or citrate, an ingredient soluble in the non-polar solvent and having an HLB of from 2-5, a nitrogen-functional compound, or a mixture thereof, wherein the composition has a pH of from 6.5 to 8.0 and is in the form of a stable oil-in-water microemulsion.

2. A composition according to Claim 1, wherein the non-soap detersive surfactant is selected from c g c 18 alkyl benzene sulfonates, paraffin sulfonates, a—sulfonate of fatty acids, alkyl sulfates, and ethoxylated alcohols and alkyl phenols having 5 to 17 ethylene oxide groups, and mixtures thereof.

3. A composition according to Claim 1 or 2, wherein the solvent comprises terpenes, paraffin oil, C g -C g alkyl aromatics, liquid olefins, or mixtures thereof, or mixtures of terpenes, paraffin oils, C 6 -C g alkyl aromatics or olefins, with benzyl alcohol, C 4 ~C 12 alcohols, phthalic acid esters, 2-(2-alkoxyethoxy) ethanols or 2-alkoxyalkanols.

4. A composition according to Claim 3, wherein the solvent is a mixture of: (a) a non-polar solvent selected from terpenes, iso-C 10 -C 12 paraffin oils, C g -Cg alkyl benzenes or liquid olefins; and (b) a polar solvent selected from benzyl alcohol, diethylphthalate, dibutylphthalate or 2-(2-butoxyethoxy)-ethanol at a weight ratio (a) to (b) of 10:1 to 1:10.

5. A composition according to any one of Claims 1 to 4, wherein the fatty acid or soap is a mixture of lauric and myristic fatty acids or soaps, coconut alkyl fatty acid or fatty soap mixture, or mixtures of palm and coconut fatty acids or soaps.

6. A composition according to any one of Claims 1 to 5 formulated at a pH of 6.6 to 7.3.

7. A composition according to any one of Claims 1 to 6 packaged in a high density polyethylene container.

8. A composition according to Claim 4, which comprises a mixture of iso-C 10 -C 12 paraffin and diethyl phthalate or dibutyl phthalate at a weight ratio of paraffin:phthalate of 5:1 to 1:5.

9. A composition according to claim 8 wherein the nitrogen-functional compound is cyclohexylamine.

10. A liquid detergent composition according to Claim 1, substantially as hereinbefore described and exemplified.