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(11) | EP 0 164 467 A1 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Cleaning compositions with solvent |
| (57) Alkyl benzene and olefin solvents are used to improve cleaning performance of conventional
laundry detergents and hard surface cleaners. Solvent combinations comprising, for
example, octyl benzene or 1-decene with a more polar solvent are disclosed for use
as cleaning and degreasing solvents. |
TECHNICAL FIELD
[0001] The present invention relates to the use of certain alkyl-aromatic or olefinic solvents to improve the cleaning performance of laundry detergents, hard-surface cleaners, and the like. Mixed solvent systems comprising the aforesaid alkyl-aromatics or olefinic solvents and a more polar solvent are also described. The solvents herein are particularly suitable for use in laundry detergents. Besides their excellent cleaning properties, the solvents of this invention have the important advantage that they have a low, pleasant odor, which allows greater latitude in perfuming formulations containing such solvents.
BACKGROUND
[0002] A variety of solvent mixtures comprising short-chain alkyl benzenes, and which appear to be contemplated for use primarily in extremely heavy-duty cleaning such as motor degreasing, removing rubber from floors, and the like, are described in U.S. Patent 3 658 708/OLS 1 942 414; U.S. 3 354 093, and DT 2 823 936.
[0003] 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 nonionic surfactants which are also well-known for their grease removal performance. Such compositions have also been suggested for cleaning carpets. British Patent 1 603 047,1981. EPO application 81200540.3 discloses hard surface cleaners comprising a mixture of benzyl alcohol, terpenes, surfactants and other detersive ingredients.
[0004] Citrus juices, which contain relatively low amounts of terpenes , have been suggested for use in hand soaps and dishwashing liquids. U.S. Patent 3 650 968, 1972; Memoire des- criptif 873 051 (relating to Brevet Anglais 53472/77, 22 December 1977).
[0005] Terpineols, e.g. from pine oil, have been disclosed for use in wet-scouring of textiles. In particular, in 1937, U.S. Patent 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.
[0006] 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.
[0007] European Patent Application 0 072 488 (August 3, 1982) 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.
[0008] Clear emulsions comprising water, surfactant and various other solvents are disclosed by Davidsohn in 3rd International Congress of Surface Activity, Cologne (1960).
[0009] The present invention encompasses the detergency use of certain alkyl-aromatic and olefinic solvents, as well as admixtures of such solvents with preferred polar co-solvents.
[0010] The solvents herein are particularly useful in laundry detergents, both in a fabric pre-treatment mode and through-the-wash, and provide excellent removal of greasy soils and stains, as well as excellent fabric whiteness maintenance. Liquid laundry detergents in the form of microemulsions are a preferred embodiment of this invention.
SUMMARY OF THE INVENTION
[0011] The present invention encompasses detergent compositions comprising conventional detersive ingredients, characterized in that they contain at least 0.1 % of a primary cleaning solvent which is selected from alkyl-aromatic solvents wherein the alkyl group is in the range of C6 to Cg,or olefins having a boiling point of about 100°C, and above.
[0012] The invention also encompasses solvent mixtures that have particularly good cleaning properties, and which are especially suitable for use in detergent compositions of the foregoing type. Such solvent mixtures are characterized in that they comprise a mixture of the aforesaid alkyl-aromatic hydrocarbon or an olefin primary cleaning solvent, together with a polar co-solvent, especially polar liquids selected from phthalic acid esters, benzyl alcohol, n-hexanol and the so-called "carbitol"-type solvents, (2-(2-alkoxyethoxy)ethanol) especially "Butyl Carbitol" (Trade Mark) and the "Cellosolves".
[0013] Preferred compositions herein comprise 1 % to 30 % (preferably 3 % to 20 %, most preferably 5 % to 15 %) of the primary cleaning solvent or primary cleaning solvent/co-solvent mixture, and highly preferred compositions comprise n-octyl benzene or 1-decene or 1-dodecene as the primary cleaning solvent. For best performance in a liquid laundry detergent, such compositions also contain a co-solvent selected from diethyl phthalate, benzyl alcohol, or Butyl Carbitol.
[0014] Detergent compositions containing the aforesaid solvents and mixtures and methods of cleaning surfaces, and particularly fabrics, using such compositions also form a part of this invention.
[0015] All percentages and ratios disclosed herein are by weight, unless otherwise specified. The ingredients are all available from commercial sources.
DETAILED DESCRIPTIQN OF THE INVGENTIONC
[0016] Primary Cleaning Solvent - This term is abbreviated hereinafter as PCS. The PCS materials used herein are of two types : alkyl-aromatic and olefinic.
[0017] As disclosed in the prior art cited above, alkyl-aromatic hydrocarbons having relatively short-chain alkyl groups are known for use in degreasing solvent mixtures, and such short-chain solvents are not contemplated for use herein. Indeed, the hepatotoxicity of short-alkyl benzenes (e.g., toluene) and their unpleasant odors disqualify such solvents for use in general-purpose laundry and cleaning compositions. Surprisingly, long-chain alkyl benzenes (alkyl C10, and above) have now been found to exhibit undersirable soil redeposition characteristics when used in fabric laundry baths. In sharp contrast, the C6-C9 alkyl benzenes (especially octyl benzene) provide excellent performance, no problems with soil redeposition in laundry baths, and have a low, pleasant odor reminiscent of almond extract. Accordingly, such materials are preferred for use as PCS materials in the practice of this invention.
[0018] Olefins, especially alpha-olefins, are the second type of PCS materials that can be used in the practice of this invention. In general, olefins used herein are selected from liquids having a boiling point at least about 100° C. In general, such olefins comprise at least 8 carbon atoms, although chain hraching can affect the boiling point, in well known fashion. The alpha-olefins are especially preferred herein, with 1-decene being the most preferred PCS material. However, 1-dodecene may be preferred over 1-decene for some detergent uses due to its excellent odor properties.
[0019] Co-Solvent : It is to be understood that the detergent compositions of this invention function well when only a PCS material is used therein. However, the PCS materials are essentially non-polar solvents. As such, they are especially suitable for cleansing non-polar soils and stains. It is particularly advantageous to blend the PCS materials with polar co-solvents to provide a broader spectrum of soil removal.
[0020] Various polar materials such as alcohols, esters, ketones, and the like can be used as the co-solvent. However, it has now been determined that especially preferred co-solvents comprise benzyl alcohol, the C4-C12 alcohols, the "carbitols" (i.e., ethoxyethanols), and the diesters of phthalic acid.
[0021] Preferred co-solvents herein are benzyl alcohol, "Butyl Carbitol" (i.e., 2-(2-Butoxyethoxy)ethanol) ; and dimethyl-, diethyl-, dipropyl-, or dibutyl-phthalate, especially diethylphthalate. Dioctyl- and diisononyl-phthalates may also be used.
[0022] The PCS/co-solvent mixtures herein generally comprise a ratio PCS:co-solvent of 10:1 to 1:10, preferably 5:1 to 1:5. In liquid laundry detergents, there is preferably more PCS than co-solvent, usually in a ratio of about 5:1 to 5:4.
FORMULATION INGREDIENTS
[0023] It is to be understood that the PCS materials, or mixtures of PCS/Co-solvents can be added to aqueous laundry liquors, hard-surface cleaning baths, daubed directly onto spots or stains, or otherwise used "neat", to achieve excellent stain and spot removal benefits. However, in a preferred mode, the solvents herein are used as fully-formulated compositions comprising typical detersive ingredients such as detersive surfactants, detergency builders, bleaches, bleach activators, enzymes, suds regulants, and the like, all well-known to the detergent art.
[0024] As will be seen from the following disclosure, such conventional detergent ingredients are used herein at conventional amounts and concentrations.
[0025] Importantly, in the formulation of liquid detergents, the solvents herein can be used in combination with relatively high (15 % - 25 %, and higher depending on solvent) levels of fatty acid/soap, which provide an important detergency builder function.
[0026] 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.
[0027] 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) alcohols and alkyl phenols, amine oxides,α-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 C9-C18 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 about 5 to about 17 ethylene oxide groups. U.S. Patents 4 111 855 and 3 995 669 contain detailed listings of such typical detersive surfactants. C11-C16 alkyl benzene sulfonates, C12-C18 paraffin-sulfonates and alkyl sulfates, and the ethoxylated alcohols and alkyl phenols are especially preferred in the compositions of the present type.
[0028] The surfactant component can comprise as little as 1% of the compositions herein, but preferably the compositions will contain 1% to 40%, preferably 10% to 40%, of surfactant. 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.
[0029] Carriers - The solvents of this invention are preferably used in liquid compositions. However, they may be formulated as granules by the expedient of spraying them onto inert solid carriers such as attapulgite, sodium sulfate, or the like. Alternatively, the solvents can be sprayed onto spray-dried detergent granules which comprise 5 % - 60 % conventional, solid, cleaning ingredients such as sodium perborate, sodium ortho- or pyro-phosphate, sodium tripolyphosphate, zeolite (especially 1-10 micron hydrated Zeolite A) or smectite clay fabric softeners. In still another mode, the solvents can be microencapsulated in rupturable or water-soluble capsules and admixed with granular detergents.
[0030] Pclyamines - Polyamine materials are optional ingredients in the present compositions by virtue of their ability to cc-act with the solvent to remove the solid material that is present in many greasy stains (e.g., carbon black in motor cil stain; clay and color bodies in cosmetic stain). It is tc 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 of the empirical structures with repeating units:
Amine form and
Quaternarized form wherein R is a hydrocarbyl group, usually of 2-6 carbon atoms; R may be a C1-C20 hydrocarbon; the alkoxy groups are polyethoxy, polypropoxy, and the like, with polyethoxy having a degree of polymerization of 2-30, most preferably 10 to 20; x is an integer of at least 2, preferably from 2-20, most preferably 3-5; and x⊖ is an anion such as halide or methylsulfate, resulting from the quaternization reaction. The anion X⊖ is of no particular consequence to performance of the polyamine in the present context, and is mentioned only for completeness in the above formula.
[0031] 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 the general formula:
wherein x is an integer of 3 to 5 and y is an integer of 10 to 20.
[0032] Polyamines typically will comprise at least about 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 through-the-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, water-soluble 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-polyphos- phonates and phosphates (DEQUEST) and a wide variety of other poly-functional organic acids and salts too numerous to mention in detail here. See U.S. Patent 3.579.454 for typical examples of the use of such materials in various cleaning compositians. In general, the buildex/sequestrant will comprise about 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 hard-surface cleaners.
[0033] A source of magnesium ions can be used in the composi- tions, to assist grease removal. Besides magne- sium hydroxide, water-soluble salts such as magnesium chloride, acetate, sulfate, and the like, can be used.
[0034] 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 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 M, 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.
[0035] 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 pH regulants, perfumes, dyes, optical brighteners, soil suspending agents, hydrotropes and gel-control agents, freeze-thaw stabilizers, bactericides, preservatives, suds control agents and the like. Such ingredients typically comprise 0.1 % - 10 % of the formulations.
[0036] 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.
Industrial Application
[0037] 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 are stated in parentheses to designate the degree of polymerization and degree of alkoxylation of the polyamine. For some "polyamines", the designation R is also included, thereby denoting a quaternarized polyamine. For such quater- narized materials, the resulting anion X is of no consequence to cleaning performance, and is not designated.
Heavy-Duty Liquid Detergents
[0038] 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.
[0039] It is to be understood that the following formulations are in the form of oil-in-water emulsions (wherein the solvent is considered the "oil" 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 concentra- ticns 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.
[0040] The preparation of stable, heavy-duty liquid detergents in their preferred oil-in-water microemulsion form is carried-out with attention being given to the water carrier liquid, the use of fatty acid/soap as a detergency builder/ emulsion stabilizer ingredient and proper attention to pH regulation.
[0041] Fatty Acids and Soaps - Patty 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) such as 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 50 %, preferably 5 % to 35 %, most preferably 10 % to 30 %, and the weight ratio of fatty acid (or soap):solvent is generally in the range of 4:1 to 1:4, preferably 3:1 to 1:2. When using fatty soap, the potassium salt form is preferred, but any convenient water-soluble salt may be used.
[0042] Apart from their function as microemulsion stabilizers, these fatty acid/soap materials provide an important deter- geney 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 maintainain a pH of 6.5 or above in microemulsions containing builder levels of fatty acid/soap are disclosed in detail, hereinafter.
[0043] Water - The liquid compositions herein may properly be characterized as "water-based", in contrast with organic solvent-based cleaners known in the art.
[0044] Surprisingly, water can interfere with the ability of solvents to remove greasy stains from fabrics. For example, a fabric stained with motor oil and dampened with water prior to treatment with a terpene solvent is not very well de-greased, if at all. By contrast, the present compositions wherein the solvents are microemulsified in water are excellent greasy stain removers when used directly on dry or damp fabrics.
[0045] 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.
[0046] Accordingly, the compositions herein exhibit the advantages of water-based formulation flexibility, together with the superior grease removal qualities of solvent-based compositions.
[0047] 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 water:solvent is generally 10:1 to 1:1, preferably 5:1 to 2:1.
[0048] pH/Stabilizer - As is well-known in the detergency arts, it is preferred for detergent compositions to be used in the near-neutral 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.
[0049] 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 "as-is" pH is adjusted to about 6.5, and above. (The pH where instability is noted may vary slightly with the level and particular grease-cutting solvent used in the microemulsion 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.g., alkyl benzenes and alpha-olefins.
[0050] 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.
[0051] It is to be understood that formulation stability could theoretically be achieved by proper selection of surfactants with low HLB's. For example, nonionic surfactants such as C14-15 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 microemulsions, but also good pre-treat and through-the-wash detergency.
[0052] It has now been found that by either increasing the ionic strength of the aqueous phase, or by adding solvent-soluble ingredients with low HLB's, which increase solvent polarity, to the solvent phase, or by using both means conjointly, the microemulsion is stabilized.
[0053] 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.
[0054] Also, adding slightly polar but solvent-soluble ingredients with low HLB's such as n-hexanol, benzyl alcohol, diethyl phthalate and the like increases stability.
[0055] Conjointly adding the ionic strength ingredients and the solvent-soluble ingredients further enchances stability. Of course, the formulator can select ingredients with a view towards not only increasing microemulsion 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 or diethyl phthalate as a low HLB ingredient which also serves a useful co-solvent cleaning function.
[0056] The amount of ionic strength or low e.g. (2-5) HLB solvent-soluble 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. Moreover, true oil-in-water microemulsions turn hazy when diluted with water, whereas water-in-oil emulsions tend to gel, and micellar oil-plus-water systems remain clear.
[0057] With regard to pH adjustments in'the compositions, any of the well-known base materials can be used, for example, triethanolamine, alkali metal hydroxide and the like. Potassium hydroxide is preferred over sodium hydroxide, inasmuch as the ease of formulation of stable systems is increased substantially by the potassium cation.
[0058] Nitrogenous Stabilizers/pH Regullants- It has now been discovered that quaternary ammonium compounds and amines constitute a highly preferred class of pH regulants and stabilizers in the oil-in-water microemulsion detergent compositions of the present type. Apparently. the quaternary or amine somehow associates with the fatty acid or anionic surfactants to form a complex which stabilizes the microemulsified oil (solvent). While the quaternaries and amines do not boost the pH very much towards the alkaline range (only a few tenths of a pH unit. measured on the product formulated "as is") the resulting boost in detergency performance is substantial.
[0059] Dioctyl dimethyl ammonium chloride is a highly preferred quaternary used herein as a pH-regulant, but there can also be mentioned the following quaternaries in increasing order of preference of use: coconut trimethyl ammonium chloride (6.66): di-coconut dimethyl ammonium chloride (6.84): coconut benzyl dimethyl ammonium chloride (6.84): and dihexyl dimethyl ammonium chloride (6.89). The numbers in parentheses denote the pH achievable by adding the respective quaternaries to a liquid oin-in-water microemulsion containing fatty acid and formulated at an "as is" pH of 6.5. For the preferred dioctyl dimethyl ammonium chloride, the pH figure is 6.94.
[0060] Alkyl- or cyclo-alkyl amines such as coconut diethanol amine. coconutalkyl dimethyl amine. trioctyl amine and (most preferred) cyclohexyl amine, can be used at levels of 0.1-5% of the compositions to adjust the pH as high as 7.5. 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.
[0061] The highly preferred. fully-formulated 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.
[0062] 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 through-the-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.
[0063] For use on hard surfaces, as rug cleaners, and as general-purpose cleaners, such compositions are diluted with water, or used full-strength, all in standard fashion.
[0064] Alternatively, the preferred PCS/co-solvent mixtures can be used full-strength as de-greasing agents, for example, or can be separately packaged as laundry additives, or the like.
[0065] The following Examples illustrate the practice of the invention, but are not intended to be limiting thereof. Examples I through IV illustrate highly preferred liquid laundry detergents.
[0066] The oil-in-water microemulsions herein have the advantage that they can be packaged in polyethylene containers without effect on said containers.
EXAMPLE I
[0068] The composition of Example I is a stable, oil-in-water microemulsion suitable for use as a laundry detergent.
EXAMPLE II
[0069] The composition of Example I is modified by replacing the n-octylbenzene by the same amount (9.1 % total formulation) of 1-decene and 1-dodecene, respectively. Product pH "as is":6.6.
EXAMPLE III
[0070] The composition of Example I is modified by replacing the n-oetyl benzene by any ef the following solvent mixtures (percentages of total formulation being specified in parentheses) : 1-decene (6.1 %)/diethylphthalate (3.0 %) ; 1-dodecene (7.3%)/l-dodecanol (1.8 %) ; n-octyl benzene (6.2 %)/diethyl phthalate (2.9 %) ; octyl benzene ( .0 %)/Butyl Carbitol (3.1 %) ; 1-decene (7.3%)/ ''Hexylcellosolve'' (1.3 %). Product pH's as is : 6.6.
EXAMPLE IV
[0071] The compositions of Examples I, II and III are modified by adding sufficient cyclohexyl amine (preferred) or dioctyldime- thylammonium chloride to adjust the "as is" pH of the compositions from 6.6 to 7.3. The resulting compositions exhibit exceptionally good fabric cleaning and whiteness maintenance.
EXAMPLE V
[0072] The compositio of Example I is modified by replacing the Ethoxylated Polyamine with any of the following alkoxylated polyamines A, B or C, having the general formula disclosed hereinbefore :
Polyamine A : x = 2 ; y = 2 ; R = ethylene; alkoxy = Ethoxy
Polyamine B : x = 20 ; y = 30 ; R = propylene; alkoxy = propoxy
Polyamine C : x = 3 ; y = 15; R = ethylene; alkoxy = ethoxy;R'=butyl
[0073] The alkoxylated polyamines contribute to the clay soil removal performance of the compositions.
EXAMPLE VI
[0074] A spray-dried granular detergent is prepared in standard fashion using the following typical ingredients at conventional levels.
1.5 parts of n-octyl benzene are pre-emulsified with soap and evenly sprayed into 100 parts of the granules prepared in the foregoing manner to improve detergency performance in a home fabric laundering operation.
[0075] 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 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, diethylphthate. butyl carbitol or the like.
[0076] Other useful polar solvents herein include the "Cellosolves" e.g. alkoxyl alkanols such as 2-butoxyethanol: C6-C12 alkanols (including benzyl alcohol) such as dodecanol, phenethyl alcohol. diglycolether acetates. and the like.
EXAMPLE VII
[0077] The following compositions comprising PCS and polar co-solvent are especially preferred for use in liquid cleaning and spot remover compositions.
[0078] The compositions VII(A-J) can be applied "neat" to remove spots and stains from fabrics, or added to an aqueous cleaning batch comprising conventional detersive ingredients.
[0079] In a preferred method of use aspect, the compositions herein are used in an aqueous laundering liquor, preferably at a liquor pH of 6.5-8.0 (measured as 1% of composition in water) to launder fabrics. Excellent cleaning is attained by agitating fabrics in such liquors especially at this preferred in-use pH range.
1. A solvent mixture suitable for use in detergent compositions, characterized in that
it comprises:
a) a primary cleaning solvent selected from the C6-C9 alkyl aromatic hydrocarbons and the olefins having a boiling point of at least about 100°C; and
b) a polar co-solvent selected from phthalic acid esters. C6-C12 alcohols, alkoxyl alkanol solvents and the 2-(2-alkoxyethoxy) ethanol solvents: at a weight ratio of (a) to (b) of 10:1 to 1:10.
2. A solvent mixture according to Claim 1 wherein the alkyl aromatic solvent is a C6-C9 alkyl benzene.
3. A composition according to Claim 2 wherein the alkyl benzene is octyl benzene.
4. A composition according to Claim 1 wherein the olefin is an alpha olefin.
5. A composition according to Claim 4 wherein the alpha olefin is I-decene or I-dodecene.
6. A composition according to Claims 3 and 5 wherein the phthalic acid ester co-solvent
is diethyl phthalate or dibutyl phthalate.
7. A composition according to Claims 3 and 5 wherein the co-solvent is selected from
2-(2-butyoxyethoxy) ethanol. benzyl alcohol. 2-butoxyethanol. phenethyl alcohol and
dodecanol.
8. A composition according to Claim 1 which additionally comprises water and is in
the form of an oil-in-water microemulsion.
9. A method of laundering fabrics by agitating fabrics in an aqueous liquor containing
a composition according to any of Claims 1-8.
10. A method according to Claim 9 wherein the liquor pH is 6.5-8.0.