EP0912670B1

EP0912670B1 - Liquid cleaning compositions

Info

Publication number: EP0912670B1
Application number: EP97932554A
Authority: EP
Inventors: Patrick Durbut; Anne-Marie Misselyn; Guy Broze
Original assignee: Colgate Palmolive Co
Current assignee: Colgate Palmolive Co
Priority date: 1996-07-09
Filing date: 1997-07-07
Publication date: 2003-10-01
Anticipated expiration: 2017-07-07
Also published as: ATE251210T1; WO1998001522A1; EP0912670A1; DE69725314D1; MY121266A; AU3598597A

Abstract

All purpose cleaning or microemulsion compositions which comprise an analephotropic negatively charged complex, a hydrocarbon ingredient, optionally, a Lewis base, neutral polymer, a cosurfactant, and water.

Description

Field of the Invention

The present invention relates to an all purpose hard surface cleaning or microemulsion composition containing an analephotropic negatively charged complex and a lewis base neutral polymer

Background of the Invention

This invention relates to an improved all-purpose liquid cleaner which can be in the form of a microemulsion designed in particular for cleaning hard surfaces and which is effective in removing grease soil and/or bath soil and in leaving unrinsed surfaces with a shiny appearance.
In recent years all-purpose liquid detergents have become widely accepted for cleaning hard surfaces, e.g., painted woodwork and panels, tiled walls, wash bowls, bathtubs, linoleum or tile floors, washable wall paper, etc.. Such all-purpose liquids comprise clear and opaque aqueous mixtures of water-soluble synthetic organic detergents and water-soluble detergent builder salts. In order to achieve comparable cleaning efficiency with granular or powdered all-purpose cleaning compositions, use of water-soluble inorganic phosphate builder salts was favored in the prior art all-purpose liquids. For example, such early phosphate-containing compositions are described in U.S. Patent Nos. 2,560,839; 3,234,138; 3,350,319; and British Patent No. 1,223,739.
In view of the environmentalist's efforts to reduce phosphate levels in ground water, improved all-purpose liquids containing reduced concentrations of inorganic phosphate builder salts or non-phosphate builder salts have appeared. A particularly useful self-opacified liquid of the latter type is described in U.S. Patent No. 4,244,840.
However, these prior art all-purpose liquid detergents containing detergent builder salts or other equivalent tend to leave films, spots or streaks on cleaned unrinsed surfaces, particularly shiny surfaces. Thus, such liquids require thorough rinsing of the cleaned surfaces which is a time-consuming chore for the user.
In order to overcome the foregoing disadvantage of the prior art all-purpose liquid, U.S. Patent No. 4,017,409 teaches that a mixture of paraffin sulfonate and a reduced concentration of inorganic phosphate builder salt should be employed. However, such compositions are not completely acceptable from an environmental point of view based upon the phosphate content. On the other hand, another alternative to achieving phosphate-free all-purpose liquids has been to use a major proportion of a mixture of anionic and nonionic detergents with minor amounts of glycol ether solvent and organic amine as shown in U.S. Patent No. 3,935,130. Again, this approach has not been completely satisfactory and the high levels of organic detergents necessary to achieve cleaning cause foaming which, in turn, leads to the need for thorough rinsing which has been found to be undesirable to today's consumers.
Another approach to formulating hard surfaced or all-purpose liquid detergent composition where product homogeneity and clarity are important considerations involves the formation of oil-in-water (o/w) microemulsions which contain one or more surface-active detergent compounds, a water-immiscible solvent (typically a hydrocarbon solvent), water and a "cosurfactant" compound which provides product stability. By definition, an o/w microemulsion is a spontaneously forming colloidal dispersion of "oil" phase particles having a particle size in the range of 25 to 800 Å in a continuous aqueous phase.
In view of the extremely fine particle size of the dispersed oil phase particles, microemulsions are transparent to light and are clear and usually highly stable against phase separation.
Patent disclosures relating to use of grease-removal solvents in o/w microemulsions include, for example, European Patent Applications EP 0137615 and EP 0137616 - Herbots et al; European Patent Application EP 0160762 - Johnston et al; and U.S. Patent No. 4,561,991- Herbots et al. Each of these patent disclosures also teaches using at least 5% by weight of grease-removal solvent.
It also is known from British Patent Application GB 2144763A to Herbots et al, published March 13, 1985, that magnesium salts enhance grease-removal performance of organic grease-removal solvents, such as the terpenes, in o/w microemulsion liquid detergent compositions. The compositions of this invention described by Herbots et al. require at least 5% of the mixture of grease-removal solvent and magnesium salt and preferably at least 5% of solvent (which may be a mixture of water-immiscible non-polar solvent with a sparingly soluble slightly polar solvent) and at least 0.1% magnesium salt.
However, since the amount of water immiscible and sparingly soluble components which can be present in an o/w microemulsion, with low total active ingredients without impairing the stability of the microemulsion is rather limited (for example, up to 18% by weight of the aqueous phase), the presence of such high quantities of grease-removal solvent tend to reduce the total amount of greasy or oily soils which can be taken up by and into the microemulsion without causing phase separation.
The following representative prior art patents also relate to liquid detergent cleaning compositions in the form of o/w microemulsions: U.S. Patents Nos.. 4,472,291 - Rosario; 4,540,448 - Gauteer et al; 3,723,330 - Sheflin,
Liquid detergent compositions which include terpenes, such as d-limonene, or other grease-removal solvent, although not disclosed to be in the form of o/w microemulsions, are the subject matter of the following representative patent documents: European Patent Application 0080749; British Patent Specification 1,603,047; 4,414,128; and 4,540,505. For example, U.S. Patent No. 4,414,128 broadly discloses an aqueous liquid detergent composition characterized by, by weight:
(a) from 1% to 20% of a synthetic anionic, nonionic, amphoteric or zwitterionic surfactant or mixture thereof;
(b) from 0.5% to 10% of a mono- or sesquiterpene or mixture thereof, at a weight ratio of (a):(b) being in the range of 5:1 to 1:3; and
(c) from 0.5% 10% of a polar solvent having a solubility in water at 15°C in the range of from 0.2% to 10%. Other ingredients present in the formulations disclosed in this patent include from 0.05% to 2% by weight of an alkali metal, ammonium or alkanolammonium soap of a C₁₃-C₂₄ fatty acid; a calcium sequestrant from 0.5% to 13% by weight; non-aqueous solvent, e.g., alcohols and glycol ethers, up to 10% by weight; and hydrotropes, e.g., urea, ethanolamines, salts of lower alkylaryl sulfonates, up to 10% by weight. All of the formulations shown in the Examples of this patent include relatively large amounts of detergent builder salts which are detrimental to surface shine.
In EP-A- 0 637 629, microemulsion all purpose liquid cleaning composition are described which which contain from 0.1 to 20 wt.% of an anionic surfactant and 0.1-20 wt.% of an esterified polyethoxyether nonionic surfactant in an aqueous medium further containing from 0.1 to 50 wt.% of a water mixable cosurfactant and 0.1 to 10 wt.% of a perfume or water insoluble hydrocarbon. It is stated in EP-A-0 637 629 that
"Although conventional nonionic surfactants can be used in the instant compositions, the employment of such conventional nonionic in the instant composition will decrease the environmental profile of the composition as well as having an adverse effect on the grease release and grease + particulate soil removal properties of the conposition."
A pH neutral microemulsion composition based on paraffin sulfonate and ethoxylated nonionic surfactant is able to deliver improved grease cleaning versus built, alkaline compositions. Besides the improved grease cleaning, this approach is much safer to surfaces as well as less aggressive on consumer's hands (Loth et al - U.S. Patent 5,075,026).
The microemulsion technology provides outstanding oil uptake capacity because of the adjustment of the curvature of the surfactant micelles by the molecules of the cosurfactant. Rod-like micelles are preferred as they can "swallow" oil to become globular without increasing the surface of contact between the hydrophobic core of the micelle and the hydrophilic continuous phase.
In diluted usage however, the microemulsion state is usually lost and the cleaning performance relies on the adsorption efficacy and leaving character of the surfactant system. Nonionic surfactants perform very well on grease, as they are excellent grease "solubilizers". Actually, they spontaneously form swollen micelles. In moderate climate countries such as the northern states of the United States and the northern countries of Europe, the soil on the hard surfaces contains a major proportion of greasy materials. It is accordingly not surprising that the anionic-nonionic surfactant based microemulsion is so efficient in those countries. In hot weather countries however, the amount of particulate soils is more important (as doors and windows remain open) and the classical microemulsion (U.S. Patent 5,075,026) shows weaknesses on this type of soil which is a mixed grease-particulate soil in nature.
The instant invention solves this problem by delivering on the solid surface to be cleaned the proper surfactant mixture that best adsorbs on the surface while keeping a good "leaving" character.
The analephotropic complex adsorbs much better on grease than on silica surface than individual anionic surfactants alone. This results in enhanced capabilities to disperse complex mixtures of grease with embedded particles of soil which are essential for particulate soil removal.
It is essential that the analephotropic mixture is negatively charged. Pseudo-nonionic surfactants resulting from anionic-cationic complexes which are not negatively charged show very low particulate soil removal.

Summary of the Invention

The present invention provides an improved, clear, liquid cleaning composition having improved interfacial tension which improves cleaning hard surfaces such as plastic, vitreous and metal surfaces having a shiny finish, oil stained floors, automative engines and other engines. More particularly, the improved cleaning compositions exhibit good grease soil removal properties due to the improved interfacial tensions, and leave the cleaned surfaces shiny without the need of or requiring only minimal additional rinsing or wiping. The latter characteristic is evidenced by little or no visible residues on the unrinsed cleaned surfaces and, accordingly, overcomes one of the disadvantages of prior art products. The instant compositions exhibit a grease release effect in that the instant compositions impede or decrease the anchoring of greasy soil on surfaces that have been cleaned with the instant compositions as compared to surfaces cleaned with a commercial composition which means that the grease soiled surface is easier to clean upon subsequent cleanings.
These desirable results are accomplished in the absence of polyphosphate or other inorganic or organic detergent builder salts; and even also in the complete absence or substantially complete absence of grease-removal solvent.
In one aspect, the invention provides a cleaning composition comprising:
(a) 3.0 to 40 wt.% of an analephotropic negatively charged complex comprising:
(i) at least one anionic surfactant selected from the group consisting of alkali metal salts of sulfonates, alkali metal salts of sulfates, alkaline earth metal salts of sulfonates and alkaline earth metal salts of sulfates, which sulfates and sulfonates include a C_8-26 carbon atoms containing hydrophobic group; and
(ii) an ethoxylated nonionic surfactant selected from the group of primary aliphatic C_8-18 alcohol ethoxylates and secondary aliphatic C_8-18 alcohol ethoxylates having 10 - 20 ethylene oxide groups;
(b) 0 to 50 wt.% of a cosurfactant selected form the group consisting of water-soluble C₃-C₄ alkanols, polypropylene glycol of the formula HO(CH₃CHCH₂O)_nH wherein n is a number from 2 to 18 and copolymers of ethylene oxide and propylene oxide and mono C₁-C₆ alkyl ethers and esters of ethylene glycol and propylene glycol having the structural formula R(X)_nOH and R₁(X)_nOH wherein R is C₁-C₆ alkyl, R₁ is C₂-C₄ acyl group, X is (OCH₂CH₃) or (OCH₂(CH₃)CH) and n is a number from 1 to 4; aliphatic mono- and di-carboxylic acids containing 2 to 10 carbon atoms, triethyl phosphate and mixtures thereof.
(c) 0 to 10 wt.% of a water insoluble hydrocarbon, essential oil or a perfume;
(d) 1 % to 7 % of a Lewis base, neutral polymer selected from the group consisting of a polyvinyl pyrrolidone, a polyethylene glycol and an alkoxylated polyhydric alcohol of the formula
wherein w equals 1-4, and x, y and z have a value between 0 and 60, provided that (x+y+z) equals 2 to 100; and
wherein R' is either a hydrogen atom or a methyl group;
(e) the balance being water;
The instant compositions excluded the use of anionic polymers and cationic polymers and cationic surfactants and zwitterionic surfactants.
The cleaning composition can be in the form of a microemulsion in which case the concentration of the water mixable cosurfactant is 0 to 50.0 wt. %, preferably 1 wt. % to 20 wt. % and the concentration of the perfume or water insoluble hydrocarbon is typically 0.4 wt. % to 10.0 wt. %.
Quite surprisingly although the perfume is not, per se, a solvent for greasy or oily soil, --even though some perfumes may, in fact, contain as much as 80% of terpenes which are known as good grease solvents -- the inventive compositions in dilute form have the capacity to solubilize up to 10 times or more of the weight of the perfume of oily and greasy soil, which is removed or loosened from the hard surface by virtue of the action of the anionic surfactant, said soil being taken up into the oil phase of the o/w microemulsion.
The invention generally provides highly concentrated microemulsion compositions in the form of either an oil-in-water (o/w) microemulsion or a water-in-oil (w/o) microemulsion which when diluted with additional water before use can form dilute o/w microemulsion compositions. Broadly, the concentrated microemulsion compositions contain, by weight, 20% to 40% of the analephotropic negatively charged complex, 1 to 7% of a Lewis base, neutral polymer, 0 to 2.5% of a fatty acid having 14 to 22 carbon atoms, 0.4% to 10% of perfume, essential oil or water insoluble hydrocarbon having 6 to 18 carbon atoms, 0 to 50% of a cosurfactant, and 20% to 97% of water.

Detailed Description of the Invention

The present invention relates to a stable all purpose cleaning or microemulsion composition comprising by weight: 3% to 40% of said analephotropic negatively charged complex, wherein the concentration of the analephotropic complex of the anionic surfactant and nonionic surfactant preferably is less than 1.5 mmol of the complex/liter of water at an adhesion tension of 10 mN/m, 0 to 50% of a cosurfactant, 0 to 2.5% of a fatty acid having 14 to 22 carbon atoms, 1 to 7% of said Lewis base neutral polymer; 0 to 10% of a water insoluble hydrocarbon, essential oil or a perfume and the balance being water. The instant compositions excluded the use of anionic polymers and cationic polymers. The cleaning composition can be in the form of a microemulsion in which case the concentration of the water mixable cosurfactant is 0 to 50.0 wt. %, preferably 0.1 wt. % to 25.0 wt. % and the concentration of the perfume, essential oil or water insoluble hydrocarbon is 0.4 wt. % to 10.0 wt. %.
One of the objects of the instant invention is to deliver higher proportions of anionic surfactant in the adsorbed layer at the solid-water interface. This is due to a boosted adsorption tendency and a closer 2-D packing by means of association between the negative charge of the anionic surfactant and the nonionic surfactant that is used in admixture with the anionic surfactant in the instant compositions. Two anionic surfactants can be used in composition wherein one of the anionic surfactants will possibly preferentially associate with the nonionic surfactant. If two anionic surfactants are present, there could be a hydrophilic-lipophilic interaction between the two anionic surfactants which will contribute to the 2-D packing at the solid-water interface. As a result of the association between anionic and nonionic surfactants, the minimum concentration required to provide a given adhesion tension at solid grease (glycerol tripalmitate)-water interface with mixtures thereof is reduced versus the concentration required with individual surfactants. A typical value for the adhesion tension is 10 mN/m that corresponds to an already good coverage of the interface, and to the formation of the 2-D packing of surfactant molecules in the adsorbed layer. As well known in the art adhesion tension is defined as the net force exerted by a solid on a liquid at the wetting line and depends upon the contact angle  which the liquid makes on the solid substrate at the equilibrium. The adhesion tension is defined as the cosine of the contact angle  that the liquid composition makes with the substrate times the surface tension of the liquid composition γ_L as measured at 25°C on a weakly polar solid substrate which is glycerol tripalmitate. The concentrations needed to deliver an adhesion tension of 10 mN/m at the grease surface are called C10s. The instant liquid compositions exhibit a superior adhesion tension increase efficacy, as measured by the value of the C10 concentrations that are below the C10s of the individual surfactants.
According to the present invention, the role of the hydrocarbon is provided by a non-water-soluble perfume. Typically, in aqueous based compositions the presence of a solubilizers, such as alkali metal lower alkyl aryl sulfonate hydrotrope, triethanolamine, urea, is required for perfume dissolution, especially at perfume levels of 1% and higher, since perfumes are generally a mixture of fragrant essential oils and aromatic compounds which are generally not water-soluble. Therefore, by incorporating the perfume into the aqueous cleaning composition as the oil (hydrocarbon) phase of the microemulsion composition, several different important advantages are achieved.
First, the cosmetic properties of the ultimate cleaning composition are improved: the compositions are both clear (as a consequence of the formation of a microemulsion) and highly fragranced (as a consequence of the perfume level).
Second, the need for use of solubilizers, which do not contribute to cleaning performance, is eliminated.
Third, an improved grease release effect and an improved grease removal capacity in neat (undiluted) usage of the dilute aspect or after dilution of the concentrate can be obtained without detergent builders or buffers or conventional grease removal solvents at neutral or addic pH and at low levels of active ingredients while improved cleaning performance can also be achieved in diluted usage.
As used herein and in the appended claims the term "perfume" is used in its ordinary sense to refer to and include any hon-water soluble fragrant substance or mixture of substances including natural (i.e., obtained by extraction of flower, herb, blossom or plant), artificial (i.e., mixture of natural oils or oil constituents) and synthetically produced substance) odoriferous substances. Typically, perfumes are complex mixtures of blends of various organic compounds such as alcohols, aldehydes, ethers, aromatic compounds and varying amounts of essential oils (e.g., terpenes) such as from 0% to 80%, usually from 10% to 70% by weight. The essential oils themselves are volatile odoriferous compounds and also serve to dissolve the other components of the perfume.
In the present invention the precise composition of the perfume is of no particular consequence to cleaning performance so long as it meets the criteria of water immiscibility and having a pleasing odor. Naturally, of course, especially for cleaning compositions intended for use in the home, the perfume, as well as all other ingredients, should be cosmetically acceptable, i.e., non-toxic, hypoallergenic, etc.
The hydrocarbon such as a perfume is present in the hard surface cleaning composition in an amount of from 0 to 10% by weight, preferably 0.4% to 10% by weight and most preferably from 0.4% to 3.0% by weight, especially preferably from 0.5% to 2.0% by weight. If the hydrocarbon (perfume) is added in amounts more than 10% by weight, the cost is increased without any additional cleaning benefit and, in fact, with some diminishing of cleaning performance insofar as the total amount of greasy or oily soil which can be taken up in the oil phase of the microemulsion will decrease proportionately.
Furthermore, although superior grease removal performance will be achieved for perfume compositions not containing any terpene solvents, it is apparently difficult for perfumers to formulate sufficiently inexpensive perfume compositions for products of this type (i.e., very cost sensitive consumer-type products) which includes less than 20%, usually less than 30%, of such terpene solvents.
Thus, merely as a practical matter, based on economic consideration, the microemulsion compositions of the present invention may often include as much as 0.2% to 7% by weight, based on the total composition, of terpene solvents introduced thereunto via the perfume component. However, even when the amount of terpene solvent in the cleaning formulation is less than 1.5% by weight, such as up to 0.6% by weight or 0.4% by weight or less, satisfactory grease removal and oil removal capacity is provided by the inventive diluted microemulsions.
Thus, for a typical formulation of a diluted microemulsion according to this invention a 20 milliliter sample of microemulsion containing 1% by weight of perfume will be able to solubilize, for example, up to 2 to 3 ml of greasy and/or oily soil, while retaining its form as a microemulsion, regardless of whether the perfume contains 0%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7% or 0.8% by weight of terpene solvent.
In place of the perfume one can employ a water insoluble paraffin or isoparaffin having 6 to 18 carbon at a concentration of 0 to 8.0 wt. %, preferably 0.4 to 8.0 wt. percent, more preferably 0.4 to 3.0 wt. %.
Suitable essential oils are selected from the group consisting of: Anethole 20/21 natural, Aniseed oil china star, Aniseed oil globe brand, Balsam (Peru), Basil oil (India), Black pepper oil, Black pepper oleoresin 40/20, Bois de Rose (Brazil) FOB, Borneol Flakes (China), Camphor oil, White, Camphor powder synthetic technical, Cananga oil (Java), Cardamom oil, Cassia oil (China), Cedarwood oil (China) BP, Cinnamon bark oil, Cinnamon leaf oil, Citronella oil, Clove bud oil, Clove leaf, Coriander (Russia), Coumarin 69°C (China), Cyclamen Aldehyde, Diphenyl oxide, Ethyl vanilin, Eucalyptol, Eucalyptus oil, Eucalyptus citriodora, Fennel oil, Geranium oil, Ginger oil, Ginger oleoresin (India), White grapefruit oil, Guaiacwood oil, Gurjun balsam, Heliotropin, Isobornyl acetate, Isolongifolene, Juniper berry oil, L-methyl acetate, Lavender oil, Lemon oil, Lemongrass oil, Lime oil distilled, Litsea Cubeba oil, Longifolene, Menthol crystals, Methyl cedryl ketone, Methyl chavicol, Methyl salicylate, Musk ambrette, Musk ketone, Musk xylol, Nutmeg oil, Orange oil, Patchouli oil, Peppermint oil, Phenyl ethyl alcohol, Pimento berry oil, Pimento leaf oil, Rosalin, Sandalwood oil, Sandenol, Sage oil, Clary sage, Sassafras oil, Spearmint oil, Spike lavender, Tagetes, Tea tree oil, Vanilin, Vetyver oil (Java), Wintergreen.
The analephotropic negatively charged complex contained in the instant compositions comprises a complex of:
(a) at least one anionic surfactant which is an alkali metal salt or an alkaline earth metal salt of a sulfonate or sulfate surfactant; and
(b) said nonionic surfactant, wherein the ratio of the anionic surfactant to the nonionic surfactant is 5:1 to 0.2:1, more preferably 2:1 to 0.4:1. The instant composition contains 3 to 40 wt. %, more preferably 5 to 20 wt. % of the analephotropic negatively charged complex.
Suitable water-soluble, anionic surfactants include those surface-active or detergent compounds which contain an organic hydrophobic group containing generally 8 to 26 carbon atoms and preferably 10 to 18 carbon atoms in their molecular structure and at least one water-solubilizing group selected from the group of sulfonate, and sulfate so as to form a water-soluble detergent. Usually, the hydrophobic group will include or comprise a C₈-C₂₂ alkyl, alkyl or acyl group. Such surfactants are employed in the form of water-soluble salts and the salt-forming cation usually is selected from the group consisting of sodium, potassium, or magnesium, with the sodium and magnesium cations again being preferred.
Examples of suitable sulfonated anionic surfactants are the well known higher alkyl mononuclear aromatic sulfonates such as the higher alkyl benzene sulfonates containing from 10 to 16 carbon atoms in the higher alkyl group in a straight or branched chain, C₈-C₁₅ alkyl toluene sulfonates and C₈-C₁₅ alkyl phenol sulfonates.
A preferred sulfonate is linear alkyl benzene sulfonate having a high content of 3- (or higher) phenyl isomers and a correspondingly low content (well below 50%) of 2-(or lower) phenyl isomers, that is, wherein the benzene ring is preferably attached in large part at the 3 or higher (for example, 4, 5, 6 or 7) position of the alkyl group and the content of the isomers in which the benzene ring is attached in the 2 or 1 position is correspondingly low. Particularly preferred materials are set forth in U.S. Patent 3,320,174.
Other examples of suitable anionic sulfonate surfactants are the paraffin sulfonates containing 10 to 20, preferably 13 to 17, carbon atoms. Primary paraffin sulfonates are made by reacting long-chain alpha olefins and bisulfites and paraffin sulfonates having the sulfonate group distributed along the paraffin chain are shown in U.S. Patents Nos.. 2,503,280; 2,507,088; 3,260,744; 3,372,188; and German Patent 735,096.
Examples of satisfactory anionic sulfate surfactants are the C₈-C₁₈ alkyl sulfate salts and the C₈-C₁₈ alkyl sulfate salts. The alkyl sulfates may be obtained by sulfating the alcohols obtained by reducing glycerides of coconut oil or tallow or mixtures thereof and neutralizing the resultant product.
The alkyl sulfates may be obtained by sulfating the alcohols obtained by reducing glycerides of coconut oil or tallow or mixtures thereof and neutralizing the resultant product.
Preferred alkyl sulfates contain 10 to 16 carbon atoms in the alkyl group.
Of the foregoing non-soap anionic surfactants used in forming the analephotropic complex, the preferred surfactants are the sodium or magnesium salts of the C₈-C₁₈ alkyl sulfates such as magnesium lauryl sulfate and sodium lauryl sulfate and mixtures thereof.
Generally, the proportion of the nonsoap-anionic surfactant will be in the range of 0.1 to 30 wt. %, preferably from 1 to 15 wt. %, by weight of the cleaning composition.
The instant composition contains as part of the analephotropic negatively charged complex 3 to 30 wt. %, preferably 4 to 15 wt. % of said nonionic surfactant.
The water soluble nonionic surfactants utilized in this invention are commercially well known and include the primary aliphatic alcohol ethoxylates and secondary aliphatic alcohol ethoxylates. The nonionic synthetic organic surfactants generally are the condensation products of an organic aliphatic hydrophobic compound and hydrophilic ethylene oxide groups. Any hydrophobic compound having a hydroxy group can be condensed with ethylene oxide or with the polyhydration product thereof, polyethylene glycol, to form a water soluble nonionic surfactant.
The nonionic surfactant class includes the condensation products of a higher alcohol (e.g., an alkanol containing 8 to 18, more preferably 8 to 12, carbon atoms in a straight or branched chain configuration) condensed with 10 to 20 moles of ethylene oxide, for example, decyl, lauryl or myristyl alcohol condensed with 12 moles of ethylene oxide (EO), myristyl alcohol condensed with 10 moles of EO per mole of myristyl alcohol, the condensation product of EO with a cut of coconut fatty alcohol containing a mixture of fatty alcohols with alkyl chains varying from 10 to 14 carbon atoms in length and wherein the condensate contains either 10 moles of EO per mole of total alcohol or 10 moles of EO per mole of alcohol.
A preferred group of the foregoing nonionic surfactants are the Neodol ethoxylates (Shell Co.), which are higher aliphatic, primary alcohol containing about 8 to 15 carbon atoms, such as C_9-11 alkanol condensed with 12 moles ethylene oxide (Neodol 91-12). Such ethoxamers have an HLB (hydrophilic/lipophilic balance) value of 13 to 18 and give good O/W emulsification, whereas ethoxamers with HLB values below 8 contain less than 4 ethylene oxide groups and tend to be poor emulsifiers and poor detergents.
The instant compositions contain 1 wt. % to 7.0 wt. % of a Lewis base, neutral polymer defined in the next paragraph which is soluble in water and has either a nitrogen or oxygen atom with a pair of free electrons such that the Lewis base, neutral polymer can electronically associate with the anionic surfactant and optionally with an active ingredient present in the composition at a concentration of about 0.1 wt. % to about 5.0 wt. %, wherein the active ingredient is a perfume or an antimicrobial agent such as triclosan or an insect repellant wherein the Lewis base, neutral polymer is deposit and anchors onto the surface of the surface being cleaned thereby holding the anionic surfactant or active ingredient in close proximity to the surface being cleaned and in the case of the active ingredient ensuring that the properties being parted by the active ingredient last longer.
The Lewis base, neutral polymers are selected from the group consisting of an alkoxylated polyhydric alcohol, a polyvinyl pyrrolidone and a polyethylene glycol. The alkoxylated polyhydric alcohol is depicted by the following formula
wherein w equals one to four and x, y and z have a value between 0 and 60, more preferably 0 to 40, provided that (x+y+z) equals 2 to 100, preferably 4 to 24 and most preferably 4 to 19, and wherein R' is either hydrogen atom or methyl group. A preferred ethoxylated polyhydric alcohol is glycerol 6EO.
The polyvinyl pyrrolidone is depicted by the formula:
wherein m is 20 to 350 more preferably 70 to 110.
The polyethylene glycol is depicted by the formula HO (CH₂-CH₂O-)_nH wherein n is 8 to 225, more preferably 10 to 180, wherein PEG600 or PEG400 are preferred which are a polyethylene glycols having a molecular weight of 600 and 400 respectively.
A cosurfactant can be optionally used in forming the microemulsion composition. Three major classes of compounds have been found to provide highly suitable cosurfactants over temperature ranges extending from 4°C to 43°C for instance; (1) water-soluble C₃-C₄ alkanols, polypropylene glycol of the formula HO(CH₃CHCH₂O)_nH wherein n is a number from 2 to 18 and copolymers of ethylene oxide and propylene oxide and mono C₁-C₆ alkyl ethers and esters of ethylene glycol and propylene glycol having the structural formulas R(X)_nOH and R₁(X)_nOH wherein R is C₁-C₆ alkyl, R₁ is C₂-C₄ acyl group, X is (OCH₂CH₂) or (OCH₂(CH₃)CH) and n is a number from 1 to 4; (2) aliphatic mono- and di-carboxylic acids containing 2 to 10 carbon atoms, preferably 3 to 6 carbons in the molecule; and (3) triethyl phosphate. Additionally, mixtures of two or more of the three classes of cosurfactant compounds may be employed where specific pH's are desired.
When the mono- and di-carboxylic acid (Class 2) cosurfactants are employed in the instant microemulsion compositions at a concentration of 2 to 10 wt. %, the microemulsion compositions can be used as a cleaners for bathtubs and other hard surfaced items, which are acid resistant thereby removing lime scale, soap scum and greasy soil from the surfaces of such items damaging such surfaces. If these surfaces are of zirconium white enamel, they can be damaged by these compositions.
An aminoalkylene phosphoric acid at a concentration of 0.01 to 0.2 wt. % can be optionally used in conjunction with the mono- and di-carboxylic acids, wherein the aminoalkylene phosphoric acid helps prevent damage to zirconium white enamel surfaces. Additionally, 0.05 to 1% of phosphoric acid can be used in the composition.
Representative members of the polypropylene glycol include dipropylene glycol and polypropylene glycol having a molecular weight of 200 to 1000, e.g., polypropylene glycol 400. Other satisfactory glycol ethers are ethylene glycol monobutyl ether (butyl cellosolve), diethylene glycol monobutyl ether (butyl carbitol), triethylene glycol monobutyl ether, mono, di, tri propylene glycol monobutyl ether, tetraethylene glycol monobutyl ether, mono, di, tripropylene glycol monomethyl ether, ethylene glycol monohexyl ether, diethylene glycol monohexyl ether, propylene glycol tertiary butyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether, ethylene glycol monopropyl ether, ethylene glycol monopentyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monopropyl ether, diethylene glycol monopentyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monopropyl ether, triethylene glycol monopentyl ether, triethylene glycol monohexyl ether, mono, di, tripropylene glycol monoethyl ether, mono, di tripropylene glycol monopropyl ether, mono, di, tripropylene glycol monopentyl ether, mono, di, tripropylene glycol monohexyl ether, mono, di, tributylene glycol mono methyl ether, mono, di, tributylene glycol monoethyl ether, mono, di, tributylene glycol monopropyl ether, mono, di, tributylene glycol monobutyl ether, mono, di, tributylene glycol monopentyl ether and mono, di, tributylene glycol monohexyl ether, ethylene glycol monoacetate and dipropylene glycol propionate. Representative members of the aliphatic carboxylic acids include C₃-C₆ alkyl and alkenyl monobasic acids such as acrylic acid and propionic acid and dibasic acids such as glutaric acid and mixtures of glutaric acid with adipic acid and succinic add, as well as mixtures of the foregoing acids.
While all of the aforementioned glycol ether compounds and acid compounds provide the described stability, the most preferred cosurfactant compounds of each type, on the basis of cost and cosmetic appearance (particularly odor), are diethylene glycol monobutyl ether and a mixture of adipic, glutaric and succinic acids, respectively. The ratio of acids in the foregoing mixture is not particularly critical and can be modified to provide the desired odor. Generally, to maximize water solubility of the acid mixture glutaric acid, the most water-soluble of these three saturated aliphatic dibasic acids, will be used as the major component.
Generally, weight ratios of adipic acid: glutaric acid:succinic acid is 1-3:1-8:1-5, preferably 1-2:1-6:1-3, such as 1:1:1, 1:2:1, 2:2:1, 1:2:1.5, 1:2:2, 2:3:2, etc. can be used with equally good results.
Still other classes of cosurfactant compounds providing stable microemulsion compositions at low and elevated temperatures are the mono-, di- and triethyl esters of phosphoric acid such as triethyl phosphate.
The amount of cosurfactant which might be required to stabilize the microemulsion compositions will, of course, depend on such factors as the surface tension characteristics of the cosurfactant, the type and amounts of the analephotropic complex and perfumes, and the type and amounts of any other additional ingredients which may be present in the composition and which have an influence on the thermodynamic factors enumerated above. Generally, amounts of cosurfactant in the range of from 0 to 50 wt. %, preferably from 1 wt. % to 20 wt. %, especially preferably from 1.5 wt. % to 15 wt. %, provide stable microemulsions for the above-described levels of primary surfactants and perfume and any other additional ingredients as described below.
As will be appreciated by the practitioner, the pH of the final microemulsion will be dependent upon the identity of the cosurfactant compound, with the choice of the cosurfactant being effected by cost and cosmetic properties, particularly odor. For example, microemulsion compositions which have a pH in the range of 1 to 10 may employ either the class 1 or the class 4 cosurfactant as the sole cosurfactant, but the pH range is reduced to 1 to 8.5 when the polyvalent metal salt is present. On the other hand, the class 2 cosurfactant can only be used as the sole cosurfactant where the product pH is below 3.2. However, where the acidic cosurfactants are employed in admixture with a glycol ether cosurfactant, compositions can be formulated at a substantially neutral pH (e.g., pH 7±1.5, preferably 7±0.2).
The ability to formulate neutral and acidic products without builders which have grease removal capacities is a feature of the present invention because the prior art microemulsion formulations most usually are highly alkaline or highly built or both.
The final essential ingredient in the hard surface cleaning compositions having improved interfacial tension properties is water. The proportion of water in the hard surface cleaning compositions generally is in the range of 20 wt. % to 97 wt. %, preferably 70 wt. % to 97 wt. % of the usual diluted o/w microemulsion composition.
The present invention also relates to a light duty liquid composition or light duty liquid microemulsion.
In addition to the above-described essential ingredients required for the formation of the all purpose hard surface cleaning compositions, the compositions of this invention may often and preferably do contain one or more additional ingredients which serve to improve overall product performance.
One such ingredient is an inorganic or organic salt or oxide of a multivalent metal cation, particularly Mg⁺⁺. The metal salt or oxide provides several benefits including improved cleaning performance in dilute usage, particularly in soft water areas, and minimized amounts of perfume required to obtain the microemulsion state. Magnesium sulfate, either anhydrous or hydrated (e.g., heptahydrate), is especially preferred as the magnesium salt. Good results also have been obtained with magnesium oxide, magnesium chloride, magnesium acetate, magnesium propionate and magnesium hydroxide. These magnesium salts can be used with formulations at neutral or acidic pH since magnesium hydroxide will not precipitate at these pH levels.
Although magnesium is the preferred multivalent metal from which the salts (inclusive of the oxide and hydroxide) are formed, other polyvalent metal ions also can be used provided that their salts are nontoxic and are soluble in the aqueous phase of the system at the desired pH level.
Thus, depending on such factors as the pH of the system, the nature of the analephotropic complex and cosurfactant, as well as the availability and cost factors, other suitable polyvalent metal ions include aluminum, copper, nickel, iron, calcium.
It should be noted, for example, that with the preferred paraffin sulfonate anionic detergent calcium salts will precipitate and should not be used. It has also been found that the aluminum salts work best at pH below 5 or when a low level, for example 1 weight percent, of citric acid is added to the composition which is designed to have a neutral pH. Alternatively, the aluminum salt can be directly added as the citrate in such case. As the salt, the same general classes of anions as mentioned for the magnesium salts can be used, such as halide (e.g., bromide, chloride), sulfate, nitrate, hydroxide, oxide, acetate, propionate.
The proportion of the multivalent salt generally will be selected so that at the appropriate weight ratio between the anionic surfactant and the nonionic surfactant, to deliver desired performance from the analephotropic surfactant mixture in terms of adsorption properties on grease surface, the physical stability of the total composition is kept, that can be impaired due to an increased hydrophobicity of the analephotropic complex in the presence of multivalent salt instead of alkali metal cation such as the sodium salt thereof. As a consequence, the proportion of the multivalent salt will be selected so that the added quantity will neutralize from 0.1 to 1.5 equivalents of the anionic surfactant, preferably 0.9 to 1.4 equivalents of the acid form of the anionic surfactant. At higher concentrations of anionic surfactant, the amount of multivalent salt will be in range of 0.5 to 1 equivalents per equivalent of anionic surfactant.
The hard surface cleaning compositions can optionally include from 0 to 2.5 wt. %, preferably from 0.1 wt. % to 2.0 wt. % of the composition of a C₈-C₂₂ fatty acid or fatty acid soap as a foam suppressant. The addition of fatty acid or fatty acid soap provides an improvement in the rinseability of the composition whether applied in neat or diluted form. Generally, however, it is necessary to increase the level of cosurfactant to maintain product stability when the fatty acid or soap is present. If more than 2.5 wt. % of a fatty acid is used in the instant compositions, the composition will become unstable at low temperatures as well as having an objectionable smell.
As example of the fatty acids which can be used as such or in the form of soap, mention can be made of distilled coconut oil fatty acids, "mixed vegetable" type fatty acids (e.g. high percent of saturated, mono-and/or polyunsaturated C₁₈ chains); oleic acid, stearic acid, palmitic acid, eiocosanoic acid, generally those fatty acids having from 8 to 22 carbon atoms being acceptable.
The all-purpose liquid cleaning or microemulsion composition of this invention may, if desired, also contain other components either to provide additional effect or to make the product more attractive to the consumer. The following are mentioned by way of example: Colors or dyes in amounts up to 0.5% by weight; bactericides in amounts up to 1% by weight; preservatives or antioxidizing agents, such as formalin, 5-chloro-2-methyl-4-isothaliazolin-3-one, 2,6-di-tert.butyl-p-cresol, in amounts up to 2% by weight; and pH adjusting agents, such as sulfuric acid or sodium hydroxide, as needed. Furthermore, if opaque compositions are desired, up to 4% by weight of an opacifier may be added.
In final form, the all-purpose cleaning or clear microemulsions exhibit stability at reduced and increased temperatures. More specifically, such compositions remain clear and stable in the range of 4°C to 50°C, especially 10°C to 43°C. Such compositions exhibit a pH in the acid or neutral range depending on intended end use. The liquids are readily pourable and exhibit a viscosity in the range of 6 to 60 milliPascal•Second (mPas.) as measured at 25°C. with a Brookfield RVT Viscometer using a #1 spindle rotating at 20 RPM. Preferably, the viscosity is maintained in the range of 10 to 40 mPas.
The compositions are directly ready for use or can be diluted as desired and in either case no or only minimal rinsing is required and substantially no residue or streaks are left behind. Furthermore, because the compositions are free of detergent builders such as alkali metal polyphosphates they are environmentally acceptable and provide a better "shine" on cleaned hard surfaces.
When intended for use in the neat form, the liquid compositions can be packaged under pressure in an aerosol container or in a pump-type sprayer for the so-called spray-and-wipe type of application.
Because the compositions as prepared are aqueous liquid formulations and since no particular mixing is required to form the all purpose cleaning or microemulsion composition, the compositions are easily prepared simply by combining all the ingredients in a suitable vessel or container. The order of mixing the ingredients is not particularly important and generally the various ingredients can be added sequentially or all at once or in the form of aqueous solutions of each or all of the primary detergents and cosurfactants can be separately prepared and combined with each other and with the perfume. The magnesium salt, or other multivalent metal compound, when present, can be added as an aqueous solution thereof or can be added directly. It is not necessary to use elevated temperatures in the formation step and room temperature is sufficient.
The instant all purpose cleaning microemulsion compositions explicitly exclude alkali metal silicates and alkali metal builders such as alkali metal polyphosphates, alkali metal carbonates, alkali metal phosphonates and alkali metal citrates because these materials, if used in the instant composition, would cause the composition to have a high pH as well as leaving residue on the surface being cleaned.
It is contemplated within the scope of the instant invention that the instant analephotropic negatively charged complex can be employed in hard surface cleaning compositions such as wood cleaners, window cleaners and light duty liquid cleaners.

The following examples are reference examples and are outside the scope of the claims. Unless otherwise specified, the proportions in the examples and elsewhere in the specification are by weight.

Reference Example 1
The following compositions in wt. % were prepared:
Raw Materials	A	B	C	D	E	F	G	H	I	J	K
Sodium paraffin sulfonate C₁₄-C₁₇ (60%)	7.0	--	--	--	3.5	3.5	3.5	3.5	--	--	--
Sodium C₉-C₁₃ linear alkylbenzene -sulfonate (LAS) (52%)	--	7.0	--	--	--	--	-- -	--	3.3	2.3	3.5
Neodol 91-5 (C_9-11 E5)	-	--	7.0	-	3.5	-	--	--	3.7 -	--	--
Neodol 91-12 (C_9-11 E₁₂)	-	--	--	7.0	-	3.5	3.5	3.5	--	4.7	3.5
Tripropylene glycol monobutyl ether	--	--	--	--	--	--	3.5	--	--	--	--
Dipropylene glycol monomethyl ether	--	--	--	--	--	--	--	3.5	--	--	3.5
d-limonene	--	--	--	--	--	--	0.8	0.8	--	--	0.8
MgSO₄·7H₂O	--	--	--	--	--	--	1.32	1.32	--	--	1.28
Water	Bal.	Bal.	Bal.	Bal.	Bal.	Bal.	Bal.	Bal.	Bal.	Bal.	Bal.
Concentration (mmol/liter) of complex of anionic surfactant and nonionic surfactant which provides an adhesion tension of 10 mN/m	0.98	2.07	0.32	0.87	0.48	0.54	--	--	0.62	0.78	--

Cleaning performance were performed at 25°C on Samples F-K

Tests	F	G	H	I	J	K
% Particulate soil removal "Kaolin" soil	69	53	96	72	81	95

Reference Example 2
The following compositions in wt. % were prepared:
Raw Materials	A	L	M	N	O	P	Q	R	S	T	U
Sodium paraffin sulfonate C₁₄-C₁₇ (60%)	7.0					3.5	3.5	3.5
Sodium lauryl sulfate (99%)		7.0							3.5	3.5
NaAEOS (1.3:1) (26.54%)											3.5
Neodol 91-5 (C_9-11 E5)									3.5
Neodol 91-12 (C_9-11 E12)										3.5	3.5
Neodol 45-18 (C_14-15 E18)			7.0			3.5
Tween 40 (polyoxyethylene (20EO) sorbitan palmitate ester)				7.0			3.5
Synperonic A20 (C_13-15 E20)				-	7.0			3.5
Water	Bal.	Bal	Bal.	Bal.	Bal.	Bal.	Bal.	Bal.	Bal.	Bal.	Bal.
Concentration (mmol/liter) of complex of anionic surfactant and nonionic surfactant which provides an adhesion tension of 10 mN/m	0.98	6.94	0.26	0.26	0.12	0.15	0.54	0.43	0.74	1.11	1.04

Cleaning performance were performed at 25°C on Samples P-R

Tests P Q R

% Particulate soll removal "Kaolin" soil 67 91 66

Claims

A cleaning composition comprising:

(a) 3.0 to 40 wt.% of an analephotropic negatively charged complex comprising:

(i) at least one anionic surfactant selected from the group consisting of alkali metal salts of sulfonates, alkali metal salts of sulfates, alkaline earth metal salts of sulfonates and alkaline earth metal salts of sulfates, which sulfates and sulfonates include a C_8-26 carbon atoms containing hydrophobic group; and

(ii) an ethoxylated nonionic surfactant selected from the group of primary aliphatic C_8-18 alcohol ethoxylates and secondary aliphatic C_8-18 alcohol ethoxylates having 10 - 20 ethylene oxide groups;

and wherein the ratio of the anionic surfactant (i) to the nonionic surfactant (ii) is 5:1 to 0.2:1;

(b) 0 to 50 wt.% of a cosurfactant selected form the group consisting of water-soluble C₃-C₄ alkanols, polypropylene glycol of the formula HO(CH₃CHCH₂O)_nH wherein n is a number from 2 to 18 and copolymers of ethylene oxide and propylene oxide and mono C₁-C₆ alkyl ethers and esters of ethylene glycol and propylene glycol having the structural formula R(X)_nOH and R₁(X)_nOH wherein R is C₁-C₆ alkyl, R₁ is C₂-C₄ acyl group, X is (OCH₂CH₃) or (OCH₂(CH₃)CH) and n is a number from 1 to 4; aliphatic mono- and di-carboxylic acids containing 2 to 10 carbon atoms, triethyl phosphate and mixtures thereof.

(c) 0 to 10 wt.% of a water insoluble hydrocarbon, essential oil or a perfume;

(d) 1 % to 7 % of a Lewis base, neutral polymer selected from the group consisting of a polyvinyl pyrrolidone, a polyethylene glycol and an alkoxylated polyhydric alcohol of the formula
wherein w equals 1-4, and x, y and z have a value between 0 and 60, provided that (x+y+z) equals 2 to 100; and
wherein R' is either a hydrogen atom or a methyl group;

(e) the balance being water;

and which cleaning composition does not comprise anionic or cationic polymers, cationic surfactants or zwitterionic surfactants; and which cleaning composition does not contain polyphosphate or other inorganic or organic builder salts.
The cleaning composition of claim 1 which further contains a salt of a multivalent metal cation.
The cleaning composition of claim 2 wherein the multivalent metal cation is magnesium or aluminium.
The cleaning composition of claim 1 further including fatty acid which has 8 to 22 carbon atoms.
The cleaning composition of claim 1 which contains from 0.1 to 50% by weight of said cosurfactant and from 0.4% to 10% by weight of said hydrocarbon.
The cleaning composition of claim 5 wherein the cosurfactant is a water soluble glycol ether.
The cleaning composition of claim 5 wherein the glycol ether is selected from the group consisting of ethylene glycol monobutylether, diethylene glycol monobutyl ether, triethylene glycol monobutylether, polypropylene glycol having an average molecular weight of from 200 to 1,000 and dipropylene glycol monomethyl ether, propylene glycol tert.butyl ether, mono, di, tri propylene glycol monobutyl ether.
The cleaning composition of claim 7 wherein the glycol ether is ethylene glycol monobutyl ether or diethylene glycol monobutyl ether.
The cleaning composition of claim 1 wherein the cosurfactant is C₃-C₆ aliphatic carboxylic acid selected from the group consisting of acrylic acid, propionic acid, glutaric acid, mixtures of glutaric acid and succinic acid and adipic acid and mixtures of any of the foregoing.
The cleaning composition of claim 9 wherein the aliphatic carboxylic acid is a mixture of adipic acid, glutaric acid and succinic acid.
The cleaning composition of claim 1 wherein the anionic surfactant is a C₉-C₁₅ alkyl benzene sulfonate or a C₁₀-C₂₀ alkane sulfonate.