A method of washing dishware/tableware in an automatic dishwashing machine having a single or multi-compartment product dispenser which is normally closed and sealed after charging the machine and prior to delivery of the dishwashing product into the wash liquor and wherein the dishwashing product comprises one or more dishwashing compositions in a unit dose form having a degree of deformability greater than about 10% and a shape and size such that the dishwashing product occupies more than about 60%, preferably more than about 85% of the volume of the corresponding compartment of the product dispenser in its closed state. The method allows for optimum delivery of active components across different washing machine types.

The present invention is in the field of dishwashing, in particular it relates to dishwashing methods including methods for washing dishware/tableware in an automatic dishwashing machine using dishwashing products in unit dose and especially pouch form. The methods of the invention are especially useful for the removal of cooked-, baked- and burnt-on soils from cookware and tableware.
Unitised doses of dishwashing detergents are found to be more attractive and convenient to some consumers because they avoid the need of the consumer to measure the product thereby giving rise to a more precise dosing and avoiding wasteful overdosing or underdosing. For this reason automatic dishwashing detergent products in tablet form have become very popular. Detergent products in pouch form are also known in the art.
It is normally the objective of the detergent formulator chemist to optimise the amount of actives delivered to the wash for a given unit cost. The amount of actives delivered to the wash is, among other factors, determined by the shape, size and density of the unitised dose form.
One of the drawbacks of unitised dose form such as tablets is that they have a fixed shape. The shape of dishwashing machine dispensers, on the other hand, is different from manufacturer to manufacturer. Tablets are designed to have a size and shape which fit all machine dispensers, this fact together with the mechanical properties of tablets usually constrains the amount of product composition which can be incorporated in the tablet. Similar considerations can also apply in the case of detergent products in pouch form.
Another drawback of detergent tablets is the fact that their manufacturing process requires the additional step of powder compaction. This slows down the dissolution rate of the ingredients forming the tablet, or requires the use of complex and expensive disintegrant systems, or makes it difficult to achieve differential dissolution of the detergent active ingredients.
Another factor that can contribute to the inefficient delivery of actives to the wash, in the case of tablets, is the need for adding carrier materials, as for example porous materials able to bind active liquid materials, binders and disintegrants. In particular, the incorporation of liquid surfactants to powder form detergent compositions can raise considerable processing difficulties and also the problem of poor dissolution through the formation of surfactant gel phases.
There is still the need for a unitised dose form which allows for optimum delivery of active components across different washing machine types and which provides improved processing and dissolution characteristics.
According to a first aspect of the present invention, there is provided a method of washing dishware/tableware in an automatic dishwashing machine having a single or multi-compartment product dispenser which is normally closed and sealed after charging the machine and prior to delivery of the dishwashing product into the wash liquor and wherein the dishwashing product comprises one or more dishwashing compositions in a unit dose form. The unit dose forms used herein are deformable and preferably have a shape and size such that they are compressibly contained within the product dispenser. The dishwashing product has a deformability, as measured following the method described hereinbelow of greater than about 5%, preferably greater than about 8%, more preferably greater than about 10% and even more preferably greater than about 20%. The shape and size of the product are also such that it occupies at least about 60%, preferably at least about 70%, more preferably at least about 80%, especially more than about 85% of the volume of the corresponding compartment of the product dispenser in its closed state. Provided that in the case of single compartment dispensers the dishwashing product can occupy at least about 40%, preferably at least about 50% of the volume of the product dispenser compartment in its closed state. The term xe2x80x9ccompressibly containedxe2x80x9d as used herein means that the product is in a state of compression within the closed product dispenser across at least one transverse section of the product. Preferably the product is in a state of compression across the smallest transverse section of the product in a direction generally perpendicular to the product dispenser closure means.
The deformability of the unit dose form may be measured using an Instrom materials tester (or similar) according to the following procedure. The unit dose form is placed on a flat surface such that it lies on a base of maximum footprint and a corresponding flat probe is brought down upon the upper surface of the unit dose form. The movement of the probe is continued until a sufficient reaction force is created to cause the unit dose form to fracture or burst. The deformability of the unit dose form may be defined as:       {                                                      displacement                                            xe2x80x83                                          of                                            xe2x80x83                                          probe                                            xe2x80x83                                          after                                            xe2x80x83                                          touching                                            xe2x80x83                                          unit                                            xe2x80x83                                          dose                                                                          form                                            xe2x80x83                                          up                                            xe2x80x83                                          to                                            xe2x80x83                                          burst                                            xe2x80x83                                          point                                                  total                          xe2x80x83                        unit                          xe2x80x83                        dose                          xe2x80x83                        form                          xe2x80x83                        thickness              }    xc3x97  100
The volume of the unit-dose containing product dispenser compartment in its closed state lies in the range from about 15 to about 70, preferably from about 18 to 50 and more preferably from about 20 to 30 ml. In the case of multi-compartment dispensers, the individual compartments generally have a volume of from about 10 to about 35 ml, preferably from about 15 to about 30 ml. The total volume of the product dispenser (both multi and single compartments) on the other hand is generally from about 20 to about 70 ml, preferably from about 30 to about 50 ml.
The deformability herein is measured when the unit dose form is resting on its maximum footprint. The deformability measured when the pouch is placed in this position is sometimes referred to herein as xe2x80x9cvertical deformabilityxe2x80x9d. The deformability measured when the unit dose form is rotated into a perpendicular plane is referred herein as xe2x80x9chorizontal deformabilityxe2x80x9d. In preferred embodiments the unit doses have differing vertical and horizontal deformability (so-called anisotropic deformability), the vertical and minimum horizontal deformability in the perpendicular plane preferably differing from each other by at least about 30% preferably at least about 40%. It is also preferred that the minimum horizontal deformability is greater than the vertical deformability. Anisotropic deformability is preferred herein from the dispenser fit, packaging and the feel and handling viewpoints.
The term xe2x80x9cunit dosexe2x80x9d herein refer to a dose of detergent product incorporating one or more dishwashing compositions and sufficient for a single wash cycle. Suitable unit dose forms include capsules, sachets and pouches which can have single or multiple compartments. Suitable unit dose forms for use herein include water-soluble, water-dispersible and water-permeable capsules, sachets and pouches. Preferred for use herein are water soluble pouches, based on partially hydrolysed polyvinyl alcohol as pouch material. Dishwashing compositions incorporated therein can be in liquid, gel, paste or pouch form, but preferably composition in liquid gel or paste form are substantially anhydrous for reasons of pouch stability.
In a preferred aspect of the invention, dishwashing product comprises a dose sufficient for a single wash cycle of an anhydrous dishwashing composition. The term anhydrous as used herein is intended to include compositions containing less than about 10% of water by weight of the composition, preferably less than about 5% of water and more preferably less than about 1%. The water can be present in the form of hydrated compounds, i.e. bound water or in the form of moisture. It is preferred that the composition contains less than about 1%, preferably less than about 0.1% free moisture. Free moisture can be measured by extracting 2 g of the product into 50 ml of dry methanol at room temperature for 20 minutes and then analysis a 1 ml aliquot of the methanol by Karl Fischer titration.
In preferred embodiments the dishwashing composition comprises an organic solvent system. The organic solvent system can simply act as a liquid carrier, but in preferred compositions, the solvent can aid removal of cooked-, baked- or burnt-on soil and thus has detergent functionality in its own right. The organic solvent system (comprising a single solvent compound or a mixture of solvent compounds) preferably has a volatile organic content above 1 mm Hg and more preferably above 0.1 mm Hg of less than about 50%, preferably less than about 20% and more preferably less than about 10% by weight of the solvent system. Herein volatile organic content of the solvent system is defined as the content of organic components in the solvent system having a vapor pressure higher than the prescribed limit at 25xc2x0 C. and atmospheric pressure.
The organic solvent system for use herein is preferably selected from organoamine solvents, inclusive of alkanolamines, alkylamines, alkyleneamines and mixtures thereof; alcoholic solvents inclusive of aromatic, aliphatic (preferably C4-C10) and cycloaliphatic alcohols and mixtures thereof; glycols and glycol derivatives inclusive of C2-C3 (poly)alkylene glycols, glycol ethers, glycol esters and mixtures thereof; and mixtures selected from organoamine solvents, alcoholic solvents, glycols and glycol derivatives. In one preferred embodiment the organic solvent comprises organoamine (especially alkanolamine) solvent and glycol ether solvent, preferably in a weight ratio of from about 3:1 to about 1:3, and wherein the glycol ether solvent is selected from ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol monobutyl ether, and mixtures thereof. Preferably, the glycol ether is a mixture of diethylene glycol monobutyl ether and propylene glycol butyl ether, especially in a weight ratio of from about 1:2 to about 2:1.
In another embodiment of the invention, the anhydrous dishwashing composition is in the form of a particulate bleach suspension in a non-aqueous liquid carrier. Preferred liquid carriers comprises at least about 50%, preferably at least about 60% and more preferable at least 90% of a solvent or solvent mixture having:
i) a fractional dispersion Hansen solubility parameter greater than about 40%, preferably greater than about 60% and more preferably greater than about 80%; and
ii) a fractional polar Hansen solubility parameter less than about 60%, preferably less than about 40% and more preferably less than about 20%.
Fractional dispersion Hansen solubility parameter of a solvent is defined as the ratio (multiplied by 100) of the dispersion Hansen solubility parameter to the sum of the dispersion, polar and hydrogen bonding Hansen solubility parameters. Fractional polar Hansen solubility parameter of a solvent is accordingly defined.
Solvents having the fractional Hansen solubility parameters described hereinabove are particularly valuable for purposes of bleach stability. These solvents have very low water absorption, this is particularly important in cases wherein the bleach is contained in pouches, because apart from the problem of loss of bleach, bleach decomposition gives rise to oxygen gas which can cause bloating of the pouch material and give the pouches a fluffy appearance (not very attractive to the consumers). Particulate bleaches suitable for use herein include inorganic peroxides inclusive of perborates and percarbonates, organic peracids inclusive of preformed monoperoxy carboxylic acids, such as phthaloyl amido peroxy hexanoic acid and di-acyl peroxides. Preferred peroxides for use herein are percarbonate and perborate bleach.
One problem in formulating particulate bleach into liquid compositions is to keep the bleach physically stable and homogeneously distributed in the liquid composition. Bleach suspension can be achieved by matching the density of the liquid carrier and the particulate bleach. To this end, the density difference between the particulate bleach and the non-aqueous liquid carrier is preferably less than about 500 Kg/m3, more preferably less than about 300 Kg/m3. High viscosity and small particle size will also contribute to the formation of a stable suspension. In one embodiment of the present invention, the particulate bleach has an average particle size from about 10 xcexcm to about 500 xcexcm, preferably from about 30 xcexcm to about 250 xcexcm, as measured using a Malvern particle size analyser based on laser diffraction. The suitable viscosities for the suspensions of the invention are from about 1,000 Kg/m sxe2x88x921 to about 100,000 Kg/m sxe2x88x921, preferably from about 5,000 Kg/m sxe2x88x921 to about 50,000 Kg/m sxe2x88x921 at shear rate of 1 sxe2x88x921; and from about 500 Kg/m sxe2x88x921 to about 50,000 Kg/m sxe2x88x921, preferably from about 800 Kg/m sxe2x88x921 to about 30,000 Kg/m sxe2x88x921 at shear rate of 150 sxe2x88x921 as measured using a Contraves Rheometer with 40 mm diameter parallel plate at 25xc2x0 C.
In preferred embodiments the dishwashing composition included in the unit dose form of the invention comprises a detersive enzyme. In another embodiment the dishwashing composition comprises an alkalinity source.
According to another aspect of the invention there is provided a unit dose dishwashing detergent composition in the form of a paste having a density greater than about 1100 Kg/m3, preferably greater than about 1300 Kg/m3.
Multi-compartment pouches suitable for use herein can include compartments with different solubilities controlled by for example pH, temperature or any other means. High temperature soluble pouches allow the handling of the pouches at ambient temperature with wet hands.
Unitised doses having multi-compartments can comprise at least one compartment containing a powder composition. This powder composition comprises traditional solid materials used in dishwashing detergent, such as builders, alkalinity sources, bleaches, etc. Especially useful are multi-compartment unit dose forms comprising different compartments for solid and for liquid compositions. The liquid compositions comprise traditional liquid materials used in dishwashing detergents, such as non-ionic surfactants or the organic solvents described hereinabove. Especially useful liquids for use in the case of multi-compartment unit dose forms comprising a powder compartment and a liquid compartment are liquids with hygroscopic and hydrophilic properties because they are capable to act as a moisture sink and reduce moisture pick-up by the powder compartment.
The present invention envisages the use of dishwashing detergent composition in unit dose form, which have a high degree of deformability. This allow optimal use of the dishwashing machine dispenser, without loosing the convenience of unit dose form. The invention also envisages the use of single and multi-compartment unit dose forms. Single compartment unit dose executions are especially useful in the case of paste/paste-like compostions. Multi-compartment unit dose form executions include unit dose forms comprising anhydrous liquids, especially useful compositions are those containing an organic solvent capable of remove baked-, cook- or burnt-on soils. The invention also envisages the use of anhydrous suspensions containing particulate bleach. Other forms of multi-compartment executions include a powder containing compartment in combination with a liquid containing compartment.
Unitised dose forms specially useful for use herein are pouches. The pouch herein is typically a closed structure which comprises one or more compartments, made of materials described herein. Subject to the constraints of deformability and dispenser fit, the pouch can be of any form, shape and material which is suitable to hold the composition, e.g. without allowing the release of the composition from the pouch prior to contact of the pouch to water. The exact execution will depend on, for example, the type and amount of the composition in the pouch, the number of compartments in the pouch, the characteristics required from the pouch to hold, protect and deliver or release the composition and/or components thereof.
The composition, or components thereof, are contained in the internal volume space of the pouch, and are typically separated from the outside environment by a barrier of water-soluble material. Typically, different components of the composition contained in different compartments of the pouch are separated from one another by a barrier of water-soluble material.
In the case of multi-compartment pouches, the compartments may be of a different colour from each other, for example a first compartment may be green or blue, and a second compartment may be white or yellow. One compartment of the pouch may be opaque or semi-opaque, and a second compartment of the pouch may be translucent, transparent, or semi-transparent. The compartments of the pouch may be the same size, having the same internal volume, or may be different sizes having different internal volumes.
For reasons of deformability and dispenser fit under compression forces, pouches or pouch compartments containing a component which is liquid will usually contain an air bubble having a volume of up to about 50%, preferably up to about 40%, more preferably up to about 30%, more preferably up to about 20%, more preferably up to about 10% of the volume space of said compartment.
The pouch is preferably made of a pouch material which is soluble or dispersible in water, and has a water-solubility of at least 50%, preferably at least 75% or even at least 95%, as measured by the method set out here after using a glass-filter with a maximum pore size of 20 microns.
50 gramsxc2x10.1 gram of pouch material is added in a pre-weighed 400 ml beaker and 245 ml xc2x11 ml of distilled water is added. This is stirred vigorously on a magnetic stirrer set at 600 rpm, for 30 minutes. Then, the mixture is filtered through a folded qualitative sintered-glass filter with a pore size as defined above (max. 20 micron). The water is dried off from the collected filtrate by any conventional method, and the weight of the remaining material is determined (which is the dissolved or dispersed fraction). Then, the % solubility or dispersability can be calculated.
Preferred pouch materials are polymeric materials, preferably polymers which are formed into a film or sheet. The pouch material can, for example, be obtained by casting, blow-moulding, extrusion or blow extrusion of the polymeric material, as known in the art.
Preferred polymers, copolymers or derivatives thereof suitable for use as pouch material are selected from polyvinyl alcohols, polyvinyl pyrrolidone, polyalkylene oxides, acrylamide, acrylic acid, cellulose, cellulose ethers, cellulose esters, cellulose amides, polyvinyl acetates, polycarboxylic acids and salts, polyaminoacids or peptides, polyamides, polyacrylamide, copolymers of maleic/acrylic acids, polysaccharides including starch and gelatine, natural gums such as xanthum and carragum. More preferred polymers are selected from polyacrylates and water-soluble acrylate copolymers, methylcellulose, carboxymethylcellulose sodium, dextrin, ethylcellulose, hydroxyethyl cellulose, hydroxypropyl methylcellulose, maltodextrin, polymethacrylates, and most preferably selected from polyvinyl alcohols, polyvinyl alcohol copolymers and hydroxypropyl methyl cellulose (HPMC), and combinations thereof. Preferably, the level of polymer in the pouch material, for example a PVA polymer, is at least 60%.
The polymer can have any weight average molecular weight, preferably from about 1000 to 1,000,000, more preferably from about 10,000 to 300,000 yet more preferably from about 20,000 to 150,000.
Mixtures of polymers can also be used as the pouch material. This can be beneficial to control the mechanical and/or dissolution properties of the compartments or pouch, depending on the application thereof and the required needs. Suitable mixtures include for example mixtures wherein one polymer has a higher water-solubility than another polymer, and/or one polymer has a higher mechanical strength than another polymer. Also suitable are mixtures of polymers having different weight average molecular weights, for example a mixture of PVA or a copolymer thereof of a weight average molecular weight of about 10,000-40,000, preferably around 20,000, and of PVA or copolymer thereof, with a weight average molecular weight of about 100,000 to 300,000, preferably around 150,000.
Also suitable herein are polymer blend compositions, for example comprising hydrolytically degradable and water-soluble polymer blends such as polylactide and polyvinyl alcohol, obtained by mixing polylactide and polyvinyl alcohol, typically comprising about 1-35% by weight polylactide and about 65% to 99% by weight polyvinyl alcohol.
Preferred for use herein are polymers which are from about 60% to about 98% hydrolysed, preferably about 80% to about 90% hydrolysed, to improve the dissolution characteristics of the material.
Most preferred pouch materials are PVA films known under the trade reference Monosol M8630, as sold by Chris-Craft Industrial Products of Gary, Ind., US, and PVA films of corresponding solubility and deformability characteristics. Other films suitable for use herein include films known under the trade reference PT film or the K-series of films supplied by Aicello, or VF-HP film supplied by Kuraray.
The pouch material herein can also comprise one or more additive ingredients. For example, it can be beneficial to add plasticisers, for example glycerol, ethylene glycol, diethyleneglycol, propylene glycol, sorbitol and mixtures thereof. Other additives include functional detergent additives to be delivered to the wash water, for example organic polymeric dispersants, etc.
The pouch can be prepared according to methods known in the art. The pouch is typically prepared by first cutting an appropriately sized piece of pouch material, preferably the pouch material. The pouch material is then folded to form the necessary number and size of compartments and the edges are sealed using any suitable technology, for example heat sealing, wet sealing or pressure sealing. Preferably, a sealing source is brought into contact with the pouch material, heat or pressure is applied and the pouch material is sealed.
The pouch material is typically introduced to a mould and a vacuum applied so that the pouch material is flush with the inner surface of the mould, thus forming a vacuum formed indent or niche in said pouch material. This is referred to as vacuum-forming.
Another suitable method is thermo-forming. Thermo-forming typically involves the step of forming an open pouch in a mould under application of heat, which allows the pouch material to take on the shape of the mould.
Typically more than one piece of pouch material is used for making multi-compartment pouches. For example, a first piece of pouch material can be vacuum pulled into the mould so that said pouch material is flush with the inner walls of the mould. A second piece of pouch material can then be positioned such that it at least partially overlaps, and preferably completely overlaps, with the first piece of pouch material. The first piece of pouch material and second piece of pouch material are sealed together. The first piece of pouch material and second piece of pouch material can be made of the same type of material or can be different types of material.
In a preferred process, a piece of pouch material is folded at least twice, or at least three pieces of pouch material are used, or at least two pieces of pouch material are used wherein at least one piece of pouch material is folded at least once. The third piece of pouch material, or a folded piece of pouch material, creates a barrier layer that, when the sachet is sealed, divides the internal volume of said sachet into at least two or more compartments.
The pouch can also be prepared by fitting a first piece of the pouch material into a mould, for example the first piece of film may be vacuum pulled into the mould so that said film is flush with the inner walls of the mould. A composition, or component thereof, is typically poured into the mould. A pre-sealed compartment made of pouch material, is then typically placed over the mould containing the composition, or component thereof. The pre-sealed compartment preferably contains a composition, or component thereof. The pre-sealed compartment and said first piece of pouch material may be sealed together to form the pouch.
The detergent and cleaning compositions herein can comprise traditional detergency components and can also comprise organic solvents having a cleaning function and organic solvents having a carrier or diluent function or some other specialised function. The compositions will generally be built and comprise one or more detergent active components which may be selected from colorants, bleaching agents, surfactants, alkalinity sources, enzymes, thickeners (in the case of liquid, paste, cream or gel compositions), anti-corrosion agents (e.g. sodium silicate) and disrupting and binding agents (in the case of powder, granules or tablets). Highly preferred detergent components include a builder compound, an alkalinity source, a surfactant, an enzyme and a bleaching agent.
Unless otherwise specified, the components described hereinbelow can be incorporated either in the organic solvent compositions and/or the detergent or cleaning compositions.
The organic solvents should be selected so as to be compatible with the tableware/cookware as well as with the different parts of an automatic dishwashing machine. Furthermore, the solvent system should be effective and safe to use having a volatile organic content above 1 mm Hg (and preferably above 0.1 mm Hg) of less than about 50%, preferably less than about 30%, more preferably less than about 10% by weight of the solvent system. Also they should have very mild pleasant odours. The individual organic solvents used herein generally have a boiling point above about 150xc2x0 C., flash point above about 100xc2x0 C. and vapor pressure below about 1 mm Hg, preferably below 0.1 mm Hg at 25xc2x0 C. and atmospheric pressure.
Solvents that can be used herein include: i) alcohols, such as benzyl alcohol, 1,4-cyclohexanedimethanol, 2-ethyl-1-hexanol, furfuryl alcohol, 1,2-hexanediol and other similar materials; ii) amines, such as alkanolamines (e.g. primary alkanolamines: monoethanolamine, monoisopropanolamine, diethylethanolamine, ethyl diethanolamine; secondary alkanolamines: diethanolamine, diisopropanolamine, 2-(methylamino)ethanol; ternary alkanolamines: triethanolamine, triisopropanolamine); alkylamines (e.g. primary alkylamines: monomethylamine, monoethylamine, monopropylamine, monobutylamine, monopentylamine, cyclohexylamine), secondary alkylamines: (dimethylamine), alkylene amines (primary alkylene amines: ethylenediamine, propylenediamine) and other similar materials; iii) esters, such as ethyl lactate, methyl ester, ethyl acetoacetate, ethylene glycol monobutyl ether acetate, diethylene glycol monoethyl ether acetate, diethylene glycol monobutyl ether acetate and other similar materials; iv) glycol ethers, such as ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, propylene glycol butyl ether and other similar materials; v) glycols, such as propylene glycol, diethylene glycol, hexylene glycol (2-methyl-2, 4 pentanediol), triethylene glycol, composition and dipropylene glycol and other similar materials; and mixtures thereof.
In the methods of the present invention for use in automatic dishwashing the detergent surfactant is preferably low foaming by itself or in combination with other components (i.e. suds suppressers). Surfactants suitable herein include anionic surfactants such as alkyl sulfates, alkyl ether sulfates, alkyl benzene sulfonates, alkyl glyceryl sulfonates, alkyl and alkenyl sulphonates, alkyl ethoxy carboxylates, N-acyl sarcosinates, N-acyl taurates and alkyl succinates and sulfosuccinates, wherein the alkyl, alkenyl or acyl moiety is C5-C20, preferably C10-C18 linear or branched; cationic surfactants such as chlorine esters (U.S. Pat. No. 4,228,042, U.S. Pat. No. 4,239,660 and U.S. Pat. No. 4,260,529) and mono C6-C16 N-alkyl or alkenyl ammonium surfactants wherein the remaining N positions are substituted by methyl, hydroxyethyl or hydroxypropyl groups; low and high cloud point nonionic surfactants and mixtures thereof including nonionic alkoxylated surfactants (especially ethoxylates derived from C6-C18 primary alcohols), ethoxylated-propoxylated alcohols (e.g., Olin Corporation""s Poly-Tergent(copyright) SLF18), epoxy-capped poly(oxyalkylated) alcohols (e.g., Olin Corporation""s Poly-Tergent(copyright) SLF18B xe2x80x94see WO-A-94/22800), ether-capped poly(oxyalkylated) alcohol surfactants, and block polyoxyethylene-polyoxypropylene polymeric compounds such as PLURONIC(copyright), REVERSED PLURONIC(copyright), and TETRONIC(copyright) by the BASF-Wyandotte Corp., Wyandotte, Mich.; amphoteric surfactants such as the C12-C20 alkyl amine oxides (preferred amine oxides for use herein include lauryldimethyl amine oxide and hexadecyl dimethyl amine oxide), and alkyl amphocarboxylic surfactants such as Miranol(trademark) C2M; and zwitterionic surfactants such as the betaines and sultaines; and mixtures thereof. Surfactants suitable herein are disclosed, for example, in U.S. Pat. No.3,929,678, U.S. Pat. No. 4,259,217, EP-A-0414 549, WO-A-93/08876 and WO-A-93/08874. Surfactants are typically present at a level of from about 0.2% to about 30% by weight, more preferably from about 0.5% to about 10% by weight, most preferably from about 1% to about 5% by weight of composition. Preferred surfactant for use herein are low foaming and include low cloud point nonionic surfactants and mixtures of higher foaming surfactants with low cloud point nonionic surfactants which act as suds suppresser therefor.
Builders suitable for use in detergent and cleaning compositions herein include water-soluble builders such as citrates, carbonates and polyphosphates e.g. sodium tripolyphosphate and sodium tripolyphosphate hexahydrate, potassium tripolyphosphate and mixed sodium and potassium tripolyphosphate salts; and partially water-soluble or insoluble builders such as crystalline layered silicates (EP-A-0164514 and EP-A-0293640) and aluminosilicates inclusive of Zeolites A, B, P, X, HS and MAP. The builder is typically present at a level of from about 1% to about 80% by weight, preferably from about 10% to about 70% by weight, most preferably from about 20% to about 60% by weight of composition.
Amorphous sodium silicates having an SiO2:Na2O ratio of from 1.8 to 3.0, preferably from 1.8 to 2.4, most preferably 2.0 can also be used herein although highly preferred from the viewpoint of long term storage stability are compositions containing less than about 22%, preferably less than about 15% total (amorphous and crystalline) silicate.
Enzyme
Enzymes suitable herein include bacterial and fungal cellulases such as Carezyme and Celluzyme (Novo Nordisk A/S); peroxidases; lipases such as Amano-P (Amano Pharmaceutical Co.), M1 LipaseR and LipomaxR (Gist-Brocades) and LipolaseR and Lipolase UltraR (Novo); cutinases; proteases such as EsperaseR, AlcalaseR, DurazymR and SavinaseR (Novo) and MaxataseR, MaxacalR, ProperaseR and MaxapemR (Gist-Brocades); and xcex1 and xcex2 amylases such as Purafect Ox AmR (Genencor) and TermamylR, BanR, FungamylR, DuramylR, and NatalaseR (Novo); and mixtures thereof. Enzymes are preferably added herein as prills, granulates, or cogranulates at levels typically in the range from about 0.0001% to about 2% pure enzyme by weight of composition.
Bleaching Agent
Bleaching agents suitable herein include chlorine and oxygen bleaches, especially inorganic perhydrate salts such as sodium perborate mono-and tetrahydrates and sodium percarbonate optionally coated to provide controlled rate of release (see, for example, GB-A-1466799 on sulfate/carbonate coatings), preformed organic peroxyacids and mixtures thereof with organic peroxyacid bleach precursors and/or transition metal-containing bleach catalysts (especially manganese or cobalt). Inorganic perhydrate salts are typically incorporated at levels in the range from about 1% to about 40% by weight, preferably from about 2% to about 30% by weight and more preferably from abut 5% to about 25% by weight of composition. Peroxyacid bleach precursors preferred for use herein include precursors of perbenzoic acid and substituted perbenzoic acid; cationic peroxyacid precursors; peracetic acid precursors such as TAED, sodium acetoxybenzene sulfonate and pentaacetylglucose; pernonanoic acid precursors such as sodium 3,5,5-trimethylhexanoyloxybenzene sulfonate (iso-NOBS) and sodium nonanoyloxybenzene sulfonate (NOBS); amide substituted alkyl peroxyacid precursors (EP-A-0170386); and benzoxazin peroxyacid precursors (EP-A-0332294 and EP-A-0482807). Bleach precursors are typically incorporated at levels in the range from about 0.5% to about 25%, preferably from about 1% to about 10% by weight of composition while the preformed organic peroxyacids themselves are typically incorporated at levels in the range from 0.5% to 25% by weight, more preferably from 1% to 10% by weight of composition. Bleach catalysts preferred for use herein include the manganese triazacyclononane and related complexes (U.S. Pat. No. 4,246,612, U.S. Pat. No. 5,227,084); Co, Cu, Mn and Fe bispyridylamine and related complexes (U.S. Pat. No. 5,114,611); and pentamine acetate cobalt(III) and related complexes (U.S. Pat. No. 4,810,410).
Low Cloud Point Non-Ionic Surfactants and Suds Suppressers
The suds suppressers suitable for use herein include nonionic surfactants having a low cloud point. xe2x80x9cCloud pointxe2x80x9d, as used herein, is a well known property of nonionic surfactants which is the result of the surfactant becoming less soluble with increasing temperature, the temperature at which the appearance of a second phase is observable is referred to as the xe2x80x9ccloud pointxe2x80x9d (See Kirk Othmer, pp. 360-362). As used herein, a xe2x80x9clow cloud pointxe2x80x9d nonionic surfactant is defined as a nonionic surfactant system ingredient having a cloud point of less than 30xc2x0 C., preferably less than about 20xc2x0 C., and even more preferably less than about 10xc2x0 C., and most preferably less than about 7.5xc2x0 C. Typical low cloud point nonionic surfactants include nonionic alkoxylated surfactants, especially ethoxylates derived from primary alcohol, and polyoxypropylene/polyoxyethylene/polyoxypropylene (PO/EO/PO) reverse block polymers. Also, such low cloud point nonionic surfactants include, for example, ethoxylated-propoxylated alcohol (e.g., Olin Corporation""s Poly-Tergent(copyright) SLF18) and epoxy-capped poly(oxyalkylated) alcohols (e.g., Olin Corporation""s Poly-Tergent(copyright) SLF18B series of nonionics, as described, for example, in U.S. Pat. No. 5,576,281).
Preferred low cloud point surfactants are the ether-capped poly(oxyalkylated) suds suppresser having the formula:
wherein R1 is a linear, alkyl hydrocarbon having an average of from about 7 to about 12 carbon atoms, R2 is a linear, alkyl hydrocarbon of about 1 to about 4 carbon atoms, R3 is a linear, alkyl hydrocarbon of about 1 to about 4 carbon atoms, x is an integer of about 1 to about 6, y is an integer of about 4 to about 15, and z is an integer of about 4 to about 25.
Other low cloud point nonionic surfactants are the ether-capped poly(oxyalkylated) having the formula:
RIO(RIIO)nCH(CH3)ORIII
wherein, RI is selected from the group consisting of linear or branched, saturated or unsaturated, substituted or unsubstituted, aliphatic or aromatic hydrocarbon radicals having from about 7 to about 12 carbon atoms; RII, may be the same or different, and is independently selected from the group consisting of branched or linear C2 to C7 alkylene in any given molecule; n is a number from 1 to about 30; and RIII, is selected from the group consisting of:
(i) a 4 to 8 membered substituted, or unsubstituted heterocyclic ring containing from 1 to 3 hetero atoms; and
(ii) linear or branched, saturated or unsaturated, substituted or unsubstituted, cyclic or acyclic, aliphatic or aromatic hydrocarbon radicals having from about 1 to about 30 carbon atoms;
(b) provided that when R2 is (ii) then either: (A) at least one of R1 is other than C2 to C3 alkylene; or (B) R2 has from 6 to 30 carbon atoms, and with the further proviso that when R2 has from 8 to 18 carbon atoms, R is other than C1 to C5 alkyl.
Other suitable components herein include organic polymers having dispersant, anti-redeposition, soil release or other detergency properties invention in levels of from about 0.1% to about 30%, preferably from about 0.5% to about 15%, most preferably from about 1% to about 10% by weight of composition. Preferred anti-redeposition polymers herein include acrylic acid containing polymers such as Sokalan PA30, PA20, PA15, PA10 and Sokalan CP10 (BASF GmbH), Acusol 45N, 480N, 460N (Rohm and Haas), acrylic acidimaleic acid copolymers such as Sokalan CP5 and acrylic/methacrylic copolymers. Preferred soil release polymers herein include alkyl and hydroxyalkyl celluloses (U.S. Pat. No. 4,000,093), polyoxyethylenes, polyoxypropylenes and copolymers thereof, and nonionic and anionic polymers based on terephthalate esters of ethylene glycol, propylene glycol and mixtures thereof.
Heavy metal sequestrants and crystal growth inhibitors are suitable for use herein in levels generally from about 0.005% to about 20%, preferably from about 0.1% to about 10%, more preferably from about 0.25% to about 7.5% and most preferably from about 0.5% to about 5% by weight of composition, for example diethylenetriamine penta (methylene phosphonate), ethylenediamine tetra(methylene phosphonate) hexamethylenediamine tetra(methylene phosphonate), ethylene diphosphonate, hydroxy-ethylene-1,1-diphosphonate, nitrilotriacetate, ethylenediaminotetracetate, ethylenediamine-N,Nxe2x80x2-disuccinate in their salt and free acid forms.
The compositions herein can contain a corrosion inhibitor such as organic silver coating agents in levels of from about 0.05% to about 10%, preferably from about 0.1% to about 5% by weight of composition (especially paraffins such as Winog 70 sold by Wintershall, Salzbergen, Germany), nitrogen-containing corrosion inhibitor compounds (for example benzotriazole and benzimadazole xe2x80x94see GB-A-1137741) and Mn(II) compounds, particularly Mn(II) salts of organic ligands in levels of from about 0.005% to about 5%, preferably from about 0.01% to about 1%, more preferably from about 0.02% to about 0.4% by weight of the composition.
Other suitable components herein include colorants, water-soluble bismuth compounds such as bismuth acetate and bismuth citrate at levels of from about 0.01% to about 5%, enzyme stabilizers such as calcium ion, boric acid, propylene glycol and chlorine bleach scavengers at levels of from about 0.01% to about 6%, lime soap dispersants (see WO-A-93/08877), suds suppressors (see WO-93/08876 and EP-A-0705324), polymeric dye transfer inhibiting agents, optical brighteners, perfumes, fillers and clay.
Liquid detergent compositions can contain low quantities of low molecular weight primary or secondary alcohols such as methanol, ethanol, propanol and isopropanol can be used in the liquid detergent of the present invention. Other suitable carrier solvents used in low quantities includes glycerol, propylene glycol, ethylene glycol, 1,2-propanediol, sorbitol and mixtures thereof.


An improvement is described in all purpose liquid cleaning composition and microemulsion composition which are especially effective in the removal of oily and greasy soil and contains an anionic detergent, a nonionic surfactant, a preservative system, a short chain amphiphile, a hydrocarbon ingredient, and water.

The present invention relates to liquid cleaning composition containing short chain amphiphiles and an improved preservative system.
This invention relates to an improved all-purpose liquid cleaning composition or a microemulsion composition having an improved preservative system as well as excellent foam collapse properties and excellent grease cutting properties 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. Pat. 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. Pat. 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. Pat. 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. Pat. 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 surface 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 xe2x80x9ccosurfactantxe2x80x9d compound which provides product stability. By definition, an o/w microemulsion is a spontaneously forming colloidal dispersion of xe2x80x9coilxe2x80x9d phase particles having a particle size in the range of 25 to 800 xc3x85 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 xe2x80x94Herbots et al; European Patent Application EP 0160762 xe2x80x94Johnston et al; and U.S. Pat. No. 4,561,991 xe2x80x94Herbots 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 Mar. 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. Pat. Nos. 4,472,291xe2x80x94Rosario; U.S. Pat. No. 4,540,448xe2x80x94Gauteer et al; U.S. Pat. No. 3,723,330xe2x80x94Sheflin; etc.
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; and U.S. Pat. Nos. 4,414,128 and 4,540,505. For example, U.S. Pat. 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 15xc2x0 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.
The present invention provides an improved, liquid cleaning composition having an improved preservative system as well as excellent foam collapse properties and excellent grease cutting property in the form of a microemulsion which is suitable for cleaning hard surfaces such as plastic, vitreous and metal surfaces having a shiny finish, oil stained floors, automotive engines and other engines. More particularly, the improved cleaning compositions, with excellent foam collapse properties and excellent grease cutting property exhibit good grease soil removal properties due to the improved interfacial tensions, when used in undiluted (neat) or dilute form 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.
Surprisingly, these desirable results are accomplished even in the absence of polyphosphate or other inorganic or organic detergent builder salts and also in the complete absence or substantially complete absence of grease-removal solvent.
In one aspect, the invention generally provides a stable, microemulsion, hard surface cleaning composition especially effective in removal of oily and greasy oil, which is in the form of a substantially dilute oil-in-water microemulsion having an aqueous phase and an oil phase; The dilute microemulsion composition includes, on a weight basis:
(a) 0.1% to 8% of a sulfonate anionic surfactant;
(b) 0.5% to 6% of at least one nonionic surfactant selected from the group consisting of an ethoxylated polyhydric alcohol type compound (as defined below), an ethoxylated/propoxylated nonionic surfactant and an ethoxylated nonionic surfactant and mixtures thereof;
(c) 0.5% to 8% of a short chain amphiphile;
(d) 0.25% to 6% of magnesium sulfate heptahydrate;
(e) 0.05% to 2% of a fatty acid;
(f) 0 to 5.0%, more preferably 0.1% to 4% of a perfume, essential oil, or water insoluble hydrocarbon having 6 to 18 carbon atoms;
(g) 0.001% to 1%, more preferably 0.001% to 0.8% of at least one preservative consisting of 1,3-dimethylol-5,5-dimethyl hydantoin, isothiazolones mixtures and 5-bromo-5-nitro-1,3-dioxane, and mixtures thereof;
(h) 0.25% to 1.5%, more preferably 0.4% to 1.0% of a preservative potentiator which is imino disuccinate-sodium salt; and
(i) the balance being water, wherein the composition does not contain gluconic acid, ethylene diamine tetraacetate-sodium salt, 2-bromo-2nitropropane-1,3diol, a water-soluble polyethylene glycols having a molecular weight of 150 to 1000, polypropylene glycol of the formula HO(CH3CHCH2O)nH wherein n is a number from 2 to 18, mixtures of polyethylene glycol and polypropylene glycol (Synalox) and mono and di C1-C6 alkyl ethers and esters of ethylene glycol and propylene glycol having the structural formulas R(X)nOH, R1(X)nOH, R(X)nOR and R1(X)nOR1 wherein R is C1-C6 alkyl group, R1 is C2-C4 acyl group, X is (OCH2CH2) or (OCH2(CH3)CH) and n is a number from 1 to 4, diethylene glycol, polyamino acids, monosuccinic acids selected from the group consisting of succinic acid, glutaric acid; and phosphoric acid and any salts thereof, ethylene diamine tetraacetic acid or any salt thereof, enzymes, zeolite, alkali metal silicates, triethylene glycol, an alkyl lactate, wherein the alkyl group has 1 to 6 carbon atoms, 1methoxy-2-propanol, 1methoxy-3-propanol, and 1methoxy 2-, 3- or 4-butanol.
Excluded from the instant microemulsion and all purpose cleaning compositions are grease release agents characterized by the formula:
wherein R1 is a methyl group and R2, R3 and R4 are independently selected from the group consisting of methyl, ethyl, and CH2CH2Y, wherein Y is selected from the group consisting of Cl, Br, CO2H, (CH2O)nOH wherein n=1 to 10, OH, CH2CH9OH and x is selected from the group consisting of Cl, Br, methosulfate
and xe2x80x94HCO3xe2x88x92
Also excluded from the instant microemulsion or all purpose cleaning compositions are grease release agents which are an ethoxylated maleic anhydride-alpha-olefin copolymer having a comblike structure with both hydrophobic and hydrophilic chains and is depicted by the formula:
wherein n is about 5 to about 14, preferably about 7 to 9, x is about 7 to 19, preferably 8 to 19 and y is of such a value as to provide a molecular weight about 10,000 to about 30,000.
The present invention relates to a stable optically clear microemulsion composition comprising approximately by weight: 0.1% to 8% of a sulfonate anionic surfactant, 0.05% to 2% of a fatty acid; 0.5% to 8% of a short chain amphiphile; 0.25% to 6% of magnesium sulfate heptahydrate; 0.5% to 6% of at least one nonionic surfactant selected from the group consisting of ethoxylated nonionics, surfactants, ethoxylated/propylated nonionic surfactant; and ethoxylated polyhydric alcohol type compound and mixtures thereof; 0 to 5% of a water insoluble hydrocarbon, essential oil or a perfume, 0.05% to 2% of a fatty acid, 0.001% to 1%, more preferably 0.001% to 0.8% of a preservative which is preferably selected from the group consisting of dimethylol dimethyl hydantoin, isothiazolone mixtures, 5-bromo-5-nitro-1,3-dioxane or mixture thereof, 0.25% to 1.5%, more preferably 0.4% to 1.0% of a preservative potentiator, and the balance being water.
According to the present invention, the role of the water insoluble hydrocarbon can be 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, etc., 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 ultimate o/w microemulsion composition, several different important advantages are achieved.
As used herein and in the appended claims the term xe2x80x9cperfumexe2x80x9d is used in its ordinary sense to refer to and include any non-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 being volatile odoriferous compounds and also serving to dissolve the other components of the perfume.
In the present invention the precise composition of the optionally used 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 instant compositions show a marked improvement in ecotoxocity as compared to existing commercial products.
In place of the perfume in either the microemulsion composition or the all purpose hard surface cleaning composition at the same previously defined concentrations that the perfume was used in either the microemulsion or the all purpose hard surface cleaning composition one can employ an essential oil or a water insoluble hydrocarbon having 6 to 18 carbon such as a paraffin or isoparaffin.
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 69xc2x0 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
Suitable water-soluble non-soap, 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 which is sulfonate group, 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, ammonium, magnesium and mono-, di- or tri- C2-C3 alkanolammonium, with the sodium, magnesium and ammonium 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.
One preferred sulfonate surfactant is a 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. Pat. No. 3,320,174.
Other suitable anionic surfactants are the olefin sulfonates, including long-chain alkene sulfonates, long-chain hydroxyalkane sulfonates or mixtures of alkene sulfonates and hydroxyalkane sulfonates. These olefin sulfonate detergents may be prepared in a known manner by the reaction of sulfur trioxide (SO3) with long-chain olefins containing 8 to 25, preferably 12 to 21 carbon atoms and having the formula RCHxe2x95x90CHR1 where R is a higher alkyl group of 6 to 23 carbons and R1 is an alkyl group of 1 to 17 carbons or hydrogen to form a mixture of sultones and alkene sulfonic acids which is then treated to convert the sultones to sulfonates. Preferred olefin sulfonates contain from 14 to 16 carbon atoms in the R alkyl group and are obtained by sulfonating an a-olefin.
Other example of operative anionic surfactants includes sodium dioctyl sulfosuccinate [di-(2 ethylhexyl) sodium sulfosuccinate being one ] and corresponding dihexyl and dioctyl esters. The preferred sulfosuccinic acid ester salts are esters of aliphitic alcohols such as saturated alkanols of 4 to 12 carbon atoms and are normally diesters of such alkanols. More preferably such are alkali metal salts of the diesters of alcohols of 6 to 10 carbons atoms and more preferably the diesters will be from octanol, such as 2-ethyl hexanol, and the sulfonic acid salt will be the sodium salt.
Especially preferred anionic sulfonate surfactants are 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. Pat. Nos. 2,503,280; 2,507,088; 3,260,744; 3,372,188; and German Patent 735,096.
Of the foregoing non-soap anionic sulfonate surfactants, the preferred surfactants are the magnesium salt of the C13-C17 paraffin or alkane sulfonates.
Generally, the proportion of the nonsoap-anionic surfactant will be in the range of 0.1 % to 8%, preferably from 1 % to 6%, by weight of the dilute microemulsion composition.
The instant composition contains about 0.5 wt. % to 6 wt. %, more preferably 1.0 wt. % to 5 wt. % of a nonionic surfactant selected from the group of an aliphatic ethoxylated nonionic surfactant, an ethoxylated polyhydric alcohol and an aliphatic ethoxylated/propoxylated nonionic surfactant.
The water soluble aliphatic ethoxylated nonionic surfactants utilized in this invention are commercially well known and include the primary aliphatic alcohol ethoxylates and secondary aliphatic alcohol ethoxylates. The length of the polyethenoxy chain can be adjusted to achieve the desired balance between the hydrophobic and hydrophilic elements.
The nonionic surfactant class includes the condensation products of a higher alcohol (e.g., an alkanol containing about 8 to 16 carbon atoms in a straight or branched chain configuration) condensed with about 4 to 20 moles of ethylene oxide, for example, lauryl or myristyl alcohol condensed with about 16 moles of ethylene oxide (EO), tridecanol condensed with about 6 to 15 moles of EO, myristyl alcohol condensed with about 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 about 14 carbon atoms in length and wherein the condensate contains either about 6 moles of EO per mole of total alcohol or about 9 moles of EO per mole of alcohol and tallow alcohol ethoxylates containing 6 EO to 11 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 9-15 carbon atoms, such as C9-C11 alkanol condensed with 4 to 10 moles of ethylene oxide (Neodol 91-8 or Neodol 91-5), C12-13 alkanol condensed with 6.5 moles ethylene oxide (Neodol 23-6.5), C12-15 alkanol condensed with 12 moles ethylene oxide (Neodol 25-12), C14-15 alkanol condensed with 13 moles ethylene oxide (Neodol 45-13), and the like. Such ethoxamers have an HLB (hydrophobic lipophilic balance) value of about 8 to 15 and give good O/W emulsification, whereas ethoxamers with HLB values below 7 contain less than 4 ethyleneoxide groups and tend to be poor emulsifiers and poor detergents.
Additional satisfactory water soluble alcohol ethylene oxide condensates are the condensation products of a secondary aliphatic alcohol containing 8 to 18 carbon atoms in a straight or branched chain configuration condensed with 5 to 30 moles of ethylene oxide. Examples of commercially available nonionic detergents of the foregoing type are C11-C15 secondary alkanol condensed with either 9 EO (Tergitol 15-S-9) or 12 EO (Tergitol 15-S-12) marketed by Union Carbide.
The ethoxylated polyhydric alcohol type compound such as an ethoxylated glycerol type compound) is a mixture of a fully esterified ethoxylated polyhydric alcohol, a partially esterified ethoxylated polyhydric alcohol and a nonesterified ethoxylated polyhydric alcohol, wherein the preferred polyhydric alcohol is glycerol, and the compound is
wherein w equals one to four, most preferably one, and B is selected from the group consisting of hydrogen or a group represented by:
wherein R is selected from the group consisting of alkyl group having 6 to 22 carbon atoms, more preferably 11 to 15 carbon atoms and alkenyl groups having 6 to 22 carbon atoms, more preferably 11 to 15 carbon atoms, wherein a hydrogenated tallow alkyl chain or a coco alkyl chain is most preferred, wherein at least one of the B groups is represented by said
and Rxe2x80x2 is selected from the group consisting of hydrogen and methyl groups; 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, wherein in Formula (I) the weight ratio of monoester/diester/triester is 40 to 90/5 to 35/1 to 20, more preferably 50 to 90/9 to 32/1 to 12, wherein the weight ratio of Formula (I) to Formula (II) is a value between 3 to 0.02, preferably 3 to 0.1, most preferably 1.5 to 0.2, wherein it is most preferred that there is more of Formula (II) than Formula (I) in the mixture that forms the compound.
The ethoxylated glycerol type compound used in the instant composition is manufactured by the Kao Corporation and sold under the trade name Levenol such as Levenol F-200 which has an average EO of 6 and a molar ratio of coco fatty acid to glycerol of 0.55 or Levenol V501/2 which has an average EO of 17 and a molar ratio of tallow fatty acid to glycerol of 1.0. It is preferred that the molar ratio of the fatty acid to glycerol is less than 1.7, more preferably less than 1.5 and most preferably less than 1.0. The ethoxylated glycerol type compound has a molecular weight of 400 to 1600, and a pH (50 grams/liter of water) of 5-7. The Levenol compounds are substantially non irritant to human skin and have a primary biodegradabillity higher than 90% as measured by the Wickbold method Bias-7d.
Two examples of the Levenol compounds are Levenol V-501/2 which has 17 ethoxylated groups and is derived from tallow fatty acid with a fatty acid to glycerol ratio of 1.0 and a molecular weight of 1465 and Levenol F-200 has 6 ethoxylated groups and is derived from coco fatty acid with a fatty acid to glycerol ratio of 0.55. Both Levenol F-200 and Levenol V-501/2 are composed of a mixture of Formula (I) and Formula (II). The Levenol compounds has ecoxicity values of algae growth inhibition  greater than 100 mg/liter; acute toxicity for Daphniae  greater than 100 mg/liter and acute fish toxicity  greater than 100 mg/liter. The Levenol compounds have a ready biodegradability higher than 60% which is the minimum required value according to OECD 301B measurement to be acceptably biodegradable.
Polyesterified nonionic compounds also useful in the instant compositions are Crovol PK-40 and Crovol PK-70 manufactured by Croda GMBH of the Netherlands. Crovol PK-40 is a polyoxyethylene (12) Palm Kernel Glyceride which has 12 EO groups. Crovol PK-70 which is preferred is a polyoxyethylene (45) Palm Kernel Glyceride have 45 EO groups.
The water soluble nonionic surfactants which can be utilized in this invention are an aliphatic ethoxylated/propoxylated nonionic surfactants which are depicted by the formula:
Rxe2x80x94Oxe2x80x94(CH2CH2O)xxe2x80x94(CH2CH2CH2O)yxe2x80x94H
or
wherein R is a branched chain alkyl group having about 10 to about 16 carbon atoms, preferably an isotridecyl group and x and y are independently numbered from 1 to 20. A preferred ethoxylated/propoxylated nonionic surfactant is Plurafac(copyright) 300 manufactured by BASF.
The composition contains about 0.5 wt. % to 8 wt. %, more preferably 1 wt. % to 6 wt. % of a short chain amphiphile which is not a surfactant and is characterized by the formula:
R1O(CH2CH2O)nH
wherein R1 is a straight or branched chain alkyl group having 2 to 6 carbon atoms and n is a number from 2 to 8, more preferably 3 to 6 and the amphiphile has an HLB of about 6 to about 9, preferably about 7 to about 8. Preferred amphiphiles have a C6 alkyl group and 2 to 5 EO such as hexanol 5 EO.
The composition also contains an inorganic or organic salt of 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 primary surfactants and amphiphiles, and so on, as well as the availability and cost factors, other suitable polyvalent metal ions include aluminum, copper, nickel, iron, calcium, etc. 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, etc.
Preferably, in the dilute compositions the metal compound is added to the composition in an amount sufficient to provide at least a stoichiometric equivalent between the anionic surfactant and the multivalent metal cation. For example, for each gram-ion of Mg++ there will be 2 gram moles of paraffin sulfonate, alkylbenzene sulfonate, etc., while for each gram-ion of Al3+ there will be 3 gram moles of anionic surfactant. Thus, the proportion of the multivalent salt generally will be selected so that one equivalent of compound will neutralize from 0.1 to 1.5 equivalents, 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 microemulsion compositions include from about 0.05% to about 2.0% by weight 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, xe2x80x9cmixed vegetablexe2x80x9d type fatty acids (e.g. high percent of saturated, mono-and/or polyunsaturated C18 chains); oleic acid, stearic acid, palmitic acid, eiocosanoic acid, and the like, generally those fatty acids having from 8 to 22 carbon atoms being acceptable.
The preservative system used in the instant compositions is a mixture of a preservative and a preservative potentiator. The preservative used in the instant composition are selected from the group consisting of 1,3-dimethylol-5,5-dimethyl hydantoin, isothiazolone mixtures and 5-bromo-5-nitro-1,3-dioxane and mixture thereof. The isothiazolone mixtures consist of binary or ternary blends of methylchloroisothiazolone, methylisothiazolone and octylisothiazolone. Kathon CG is a commercially available isothiazolone mixture consisting of methylchloroisothiazolone and methylisothiazolone in a 3:1 ratio. Another commercially available mixture is Microbicide DPIII which contains methylchloroisothiazolone, methylisothiazolone and octylisothiazolone in a 3:1:0.75 ratio.
One preservative potentiator is tetrasodium imino disuccinate (IDSNa). Other suitable potentiators are trisodium ethylene diamine N,N disuccinate (EDDS) trisodium methyl glycine diacetate, tetrasodium iminodisuccinate and tetrasodium glutamate N,N-diacetate.
The final essential ingredient in the inventive microemulsion compositions or all purpose hard surface cleaning compositions having improved interfacial tension properties is water. The proportion of water in the microemulsion or all purpose hard surface cleaning composition compositions generally is in the range of 20% to 97%, preferably 70% to 97% by weight.
The liquid cleaning 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; UV adsorber or antioxidizing agents, such as 2,6-di-tert.butyl-p-cresol, etc., in amounts up to 1% by weight; and pH adjusting agents, such as sulfuric acid, citric 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 liquid compositions exhibit stability at reduced and increased temperatures. More specifically, such compositions remain clear and stable in the range of 4xc2x0 C. to 50xc2x0 C., especially 2xc2x0 C. to 43xc2x0 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 25xc2x0 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 xe2x80x9cshinexe2x80x9d 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, 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 surfactants and amphiphiles 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 formulas 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.
The following examples illustrate liquid cleaning compositions of the described invention. Unless otherwise specified, all percentages are by weight. The exemplified compositions are illustrative only and do not limit the scope of the invention. Unless otherwise specified, the proportions in the examples and elsewhere in the specification are by weight.

Liquid cleaning composition having an improved preservative system