Prespotters are often applied in the form of a detergent liquid to stains on clothes prior to laundering. Problems that may be encountered when using prespotters include spillage and a potential for mess. Powders are generally less convenient to use and less effective than liquid prespotters, and also have potential to create mess.

A particular problem with food stains on clothes is that they are often only treatable if they are washed promptly. However at mealtimes, especially when eating out, this may be impossible, or highly inconvenient.

We have now discovered that detergents in the form of VI-phase, ringing gels can be melted, applied to stained surfaces in the molten state, and subsequently removed, by laundering, by rinsing off with cold water or, in the case of non-absorbent surfaces, by wiping or peeling off. The novel prespotting method provides more effective stain and soil removal, together with significantly reduced risk of spillage and mess. Moreover it permits stains to be treated promptly before they have dried and become fixed, without substantial wetting of the fabric. They can then be laundered at a later, more convenient time The invention provides a method of facilitating the removal of stains and/or soil from surfaces, which comprises heating a VI-phase detergent composition above its melting point, applying it, prior to melting, or preferably in the molten state to the stained and/or soiled surface, optionally allowing it to cool and reform the VI-phase, and subsequently removing it from the surface.

In the following discussion of the invention, unless stated to the contrary, the disclosure of alternative values for the upper or lower limit of the permitted range of a parameter, coupled with an indication that one of said values is more highly preferred than the other, is to be construed as an implied statement that each intermediate value of said parameter, lying between the more preferred and the less preferred of said alternatives, is itself preferred to said less preferred value and also to each value lying between said less preferred value and said intermediate value.

VI-phases, which are commonly referred to as ringing gels, are a well-known group of liquid crystal phases characterised by cubic symmetry, as revealed by X-ray diffraction, and easily recognisable as optically isotropic, immobile gels, which vibrate when struck, whence their common name.

Four different VI-phases have been proposed, of which the commonest and most preferred, for the purposes of this invention is the V1-phase. The latter is usually envisaged as comprising a cubic array of spherical micelles in a continuous aqueous medium and forms at concentrations intermediate between the mobile, optically isotropic Ll-phase and the viscous, optically anisotropic, hexagonally symmetrical H- phase (which is sometimes also referred to as the M-phase). The V1-phase tends to form L1-phase micellar solutions directly on dilution or warming. The V2-phase is envisaged as the inverse of the V1-phase, with the surfactant as the continuous medium and the water as the cubically arrayed dispersed phase. It is sometimes formed at concentrations intermediate between the H2 (inverse hexagonal) phase and the L2 (inverse micellar) phase. The Il-and 12-phases are bicontinuous phases located respectively at concentrations between the H-and La- (lamellar) phase, and between the La and H2-phases.

A number of surfactants, especially non-ionic surfactant mixtures, form VI-phases suitable for use according to the present invention, typically over a concentration range lying somewhere between 28 and 50% by weight active. We prefer to use mixtures of non-ionic surfactants having a mean HLB between 8 and 16, preferably greater than 9, more preferably greater than 10, even more preferably greater than 11, more preferably still, greater than 12, most preferably greater than 12.5, but preferably less than 15.5, more preferably less than 15, most preferably less than 14.5.

We prefer that the VI-phase has a melting point (VI/L transition temperature) above 30°C more preferably above 40°, most preferably above 45°C, but below 80°C, more preferably below 70°, even more preferably below 60°C, most preferably below 55°C.

The surfactant typically comprises an ethoxylated non-ionic surfactant, e. g. an ethoxylated fatty or synthetic alcohol having: from 8 to 25 carbon atoms, usually 10 to 20, especially 12 to 18; and up to 50, usually up to 30, especially 3 to 20, ethyleneoxy groups. We generally prefer to use mixtures of alkyl ethoxylates.

Alternatively, or additionally, we may use ethoxylated fatty acids, ethoxylated amines, ethoxylated glyceryl or sorbitan esters, ethoxy/propoxy block copolymers, alkyl polyglycosides and/or sugar esters. The surfactant may also comprise alkanolamides amine oxides, and/or amphoteric or zwitterionic surfactants, typically in proportions less than 50% by weight of the total surfactant, usually less than 40%, preferably less than 30%, more preferably less than 20%, e. g. less than 15%, often less than 10%, most preferably less than 5%. Less preferably, the surfactant may comprise small amounts of anionic, or of cationic surfactant.

The invention is applicable to the prespotting of fabrics, such as clothes upholstery or carpets, the cleaning of hard surfaces such as walls, floors, work-surfaces, alloy wheel trim or toilet bowls, either domestic or in industrial and institutional environments such as hospitals, factories or abattoirs, or in removing deposits such as chewing gum or animal excrement from paths.

For prespotting applications, we prefer to melt the product by microwaving, and a preferred embodiment of the invention provides a ringing gel adapted for use according to the invention, packed in a microwaveable container. The container may be a multi-dose bottle or jar of a material, which is transparent to microwaves, such as glass or plastic, and may optionally be fitted with liquid-dispensing means, such as an atomiser or spray attachment, or an applicator nozzle, optionally provided with distribution means, such as a porous pad of, e. g. polyurethane foam. Alternatively, the container may be a unit dose sachet or ampoule.

According to a further embodiment, the invention provides an absorptive pad impregnated with the ringing gel. The pad may be of polyurethane or rubber foam, or of a non-woven fabric. It may be provided with a handle, to enable it conveniently to be heated by temporary immersion in hot water, as an alternative to microwaving, and also to facilitate rubbing of the stain with the heated pad. For example, the pad may be attached to one side of a base plate, or the inside of a dish of lesser depth than the pad, e. g. by means of adhesive or an inward projection or projections or incurved rim on the side of the dish, and a handle may be attached to the other side. Preferably the pad is protected, when not in use, by a removable cover, such as a screw-on, snap-on or hinged lid.

A further embodiment of the invention provides a gel adapted for use according to the invention packed in a self-heating can, for use in situations where an independent source of heat is not available. Self-heating cans of the type conventionally used for heating food or beverages may be employed.

The gel may comprise auxiliary cleaning adjuvants such as enzymes, bleach, stain removers, e. g. phosphonates, abrasive particles, optical brighteners, builders, e. g. citrates, carbonates, condensed phosphates or zeolites, alkalis, dyes, perfumes and preservatives.

For large scale, e. g. industrial or institutional applications, the molten gel may be maintained in a heated reservoir.

The invention is illustrated by the following examples, in which all percentages are by weight active material based on the total weight of the gel, unless stated to the contrary: EXAMPLE I A V1 ringing gel comprised: C12-14 alkyl 8 mole ethoxylate 16% C 16-18 alkyl 20 mole ethoxylate 24% Water 60% The gel was melted at 50°C and charged to a plastic spray applicator. After cooling to ambient temperature the gel reformed. It showed no tendency to leak when the container was punctured or damaged.

The container was placed in a microwave oven and heated until the gel was fluid. The fluid was sprayed onto an area of fabric, where it cooled and set rapidly. The cooled gel showed no tendency to migrate to unsprayed areas, but was easily rinsed off the fabric with cold water.

EXAMPLE II Example I was repeated using a self-heating can, of a type used commercially to heat coffee, in order to effect melting, with similar results.

EXAMPLE III 0.5% opacifier (LYTRON@ 621) and 0.15% Perfume were added to the mixture of Example I, giving a perfumed, opaque ringing gel.

EXAMPLE IV A number of 40% active blends of C16-18 alkyl 20 mole ethoxylate (EMPILANt) KM20), with varying proportions of other fatty alcohol alkoxylates were prepared, and the"melting point" (i. e. the VI-phase/micellar phase transition temperature) of each blend was observed.

The other alkoxylates used were: 1. C12-14 alkyl 6.5 mole ethoxylate/3. 5 mole propoxylate (EMPILAN PF7169) 2. C9-11 alkyl 6 mole ethoxylate (EMPILAN@ KR6) 3. Ci2-14 alkyl 10 mole ethoxylate (EMPILAN@ KB 10) The results were as follows; % Empilan PF7169 Melting Range 10 40-45°C 12 35-40°C 14 30-35°C 18 20-30°C 20 < 20°C 22 < 20°C % Empilan KR6 Melting Range 10 40-45°C 12 35-40°C 14 30-35°C 18 < 20°C 20 < 20°C 22 < 20°C % Empilan KB10 Melting Range 10 50-60°C 12 50-60°C 14 50-60°C 18 50-60°C 20 50-60°C 22 50-60°C Blends may be selected for use according to the invention, which are in the VI-phase at normal ambient temperature.