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(11) | EP 0 312 278 A2 |
| (12) | EUROPEAN PATENT APPLICATION |
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| (54) | Detergent composition |
| (57) A detergent composition in the form of a solid, shaped article suitable for application
as a pretreatment of spots or stains prior to laundering, and having a composition
which is not substantially harder than toilet soap, is characterised by the incorporation
of a bleach which is preferably an inorganic peroxygen bleach. Extrudable and castable
compositions are disclosed. Incorporation of a hygroscopic, hydratable salt is very
strongly preferred. |
[0001] This invention relates to detergent compositions in the form of shaped articles for use as a pretreatment product, that is to say for application to spots and stains on textile articles prior to normal laundering.
[0002] Pretreatment products for this purpose are known from prior patent documents, e.g. US 3953353, US 4295845, EP-A-157653 and UK 1578289.
[0003] It is conventional to include bleaches in powdered detergent compositions for normal laundering. In such products the reactive bleach is in separate particles from other components of the composition. It is believed that bleaches have never yet been incorporated in any solid pretreatment product which has been placed on the market. To do so is inherently difficult because it entails bringing the unstable bleach material into intimate contact with other substances, far more so than is the case in a powder product.
[0004] Broadly the present invention resides in incorporating bleach in a shaped, solid pretreatment product.
[0005] An object of the preferred forms of this invention is to incorporate bleach into a shaped solid pretreatment product which is a practical product with a useful storage life in temperate and tropical climates.
[0006] Another object of the preferred forms of this invention is to incorporate bleach into a pretreatment product possessing other desirable attributes of a pretreatment product, such as effectiveness against a range of stain types, ready transferability to the textile fabric being treated and ease of removal from the fabric during subsequent laundering over a wide range of temperatures, for instance 15 to 90°C.
[0007] In one aspect this invention provides a detergent composition in the form of a solid, shaped article suitable for application to selected areas of textile articles prior to laundering, the composition being not substantially harder than soap, and characterised by including a peroxygen bleach.
[0008] Hardness is significant: in order that sufficient of the composition is transferred to a fabric by manual application, it is suitable for a composition of this invention not to be unduly hard.
[0009] Hardness may be measured by means of a penetrometer, such as a penetrometer designated PNR10 by Sommer and Runge, Berlin, Germany. We have found satisfactory products are not substantially harder than toilet soap and may be softer, whereas non-soap detergent laundry bars are distinctly harder than products of this invention.
[0010] Detergent compositions of this invention may have various combinations of ingredients, but in general will include both surfactant and non surfactant material in addition to peroxygen bleach.
[0011] In order to enhance the time during which the bleach in the stored product remains active, it is desirable to manufacture the composition with a very low free water content, preferably less than 0.5% by weight of the composition.
[0012] It is also desirable to include in the composition a hygroscopic salt having a hydrate stable above 30°C. Such a salt absorbs moisture which penetrates into the composition and traps it as the hydrate of the salt. This reduces or delays decomposition of the bleach which would occur in the simultaneous presence of moisture and other constituents of the composition.
[0013] Preferred hygroscopic salts are phosphate salts, especially trisodium orthophosphate and tetrasodium pyrophosphate. Other possible hygroscopic salts are sodium tripolyphosphate, disodium hydrogen phosphate, sodium metaborate, sodium carbonate, sodium sulphate and disodium dihydrogenorthophosphate.
[0014] The amounts of the various constituents mentioned above will generally lie within the following ranges:
1 to 20 wt% peroxygen bleach
2 to 15 wt% hygroscopic salt
5 to 70 wt% surfactant
with these percentages by weight being based on the whole composition.
[0015] The peroxygen bleach may, advantageously, be chosen in dependence on the composition in which it is to be used. We have found that different bleaches are suitable in different compositions.
[0016] Monopersulphate is generally suitable; it may be used in the form of its triple salt, containing KHSO₅ : KHSO₄ : K₂SO₄ in a molar ratio of about 2:1:1. Perborate and percarbonate are suitable for use in some compositions.
[0017] When the bleach is monopersulphate, then it is desirable to include an alkaline material in the composition, in order to buffer the pH to above 9, when the composition is applied to wet fabric. This is not required for percarbonate or perborate which are themselves alkaline. The alkaline material may be provided by orthophosphate or pyrophosphate added as hygroscopic salt(s) or may be another alkaline material such as sodium carbonate.
[0018] The inorganic peroxy bleaches may be accompanied by an organic peroxy-acid precursor. It is particularly desirable to do so when the inorganic peroxy bleach is perborate or percarbonate.
[0019] Mixtures of organic peroxy-acid precursors and inorganic peroxy-salts deliver a bleaching action at low temperatures. Peroxy-acid precursors are well known in the art and are described e.g. in British Patents 836,988, 855,735 and 970,356, in United States Patents 1,246,339, 3,332,882 and 4,128,494, in Canadian Patent 844,481 and in a series of articles by A.H. Gilbert in Detergent Age, June 1967, pages 18-20, July 1967, pages 30-33 and August 1967, pages 26, 27 and 67. Preferred peroxy-acid precursors are tetraacetylethylene diamine (TAED), tetraacetylglycoluril (TAGU), glucose pentaacetate (GPA), xylose tetraacetate (XTA), and the group of acyloxy benzene sulphonates.
[0020] The ratio by weight of the inorganic peroxy-salt to the peroxy-acid precursor (if used) should lie within the range of from 8:1 to 1:1, and preferably lies within the range of from 4:1 to 1:5:1.
[0021] The amount of bleach is conveniently expressed in terms of the amount of available oxygen, i.e. the amount of oxygen which can theoretically be delivered at application. The bleach which is included in the present compositions is generally in an amount corresponding to about 0.1 to 3.5% (by weight of the whole composition) of available oxygen. Preferably, the amount of available oxygen lies within the range of from 0.2 to 2% by weight.
[0022] Various surfactants, including soap, may be utilised in compositions of this invention. Nonionic surfactants are significant for some compositions. Nonionic and other synthetic surfactants are well known classes of compounds and are extensively described in the art, such as e.g. in Schwartz, Perry, Vol. II, 1958, "Detergents and Surface-active Agents".
[0023] Preferably any nonionic surfactants which are employed are selected from the classes of alkylene oxide condensation products with fatty alcohols, alkylphenols, fatty acids and fatty acid amides. Particularly preferred are the nonionic surfactants subjected from the class of fatty alcohol ethoxylates having HLB values within the range of 6 to 18, in particular 9 to 13, such as e.g. a C₁₃ - C₁₅ alcohol condensed with 7 moles of ethylene oxide per mole of alcohol.
[0024] Compositions of this invention can include various optional components. One optional component is an organic solvent, especially a hydrocarbon solvent having an average of eight to sixteen carbon atoms to enhance oily soil removal. Such solvent may be utilised in an amount which is 4 to 15 wt% of the composition.
[0025] The detergent pretreatment compositions may further contain conventional minor ingredients, such as lipolytic, proteolytic and amylolytic enzymes, monocarboxylic acid salts, bleach stabilisers such as e.g. the phosphonate bleach stabilisers, optical brightening agents, perfumes and dyes.
[0026] Compositions of this invention may be mixtures capable of being worked and shaped by extrusion. Other compositions are such that they can be melted and then cast into the desired shape in a mould. Preferred compositions in each category will now be described.
Extrudable compositions
[0027] Compositions in one preferred category have the appearance of immobile solids and can be handled as such. However, they can be shaped by extrusion.
[0028] These preferred compositions contain
10 to 45 wt% of nonionic surfactant
1 to 20 wt% of a peroxygen bleach
at least 10 wt% of a filler material selected from one or more of:-
0 to 70 wt% (based on the whole composition) of an organic filler which is soap, wax and/or other soft organic solid
0 to 50 wt% (based on the whole composition) of clay
0 to 40 wt% (based on the whole composition) of an inorganic particulate filler other than clay,
with the proviso that any substantial amount of inorganic filler other than clay (e.g. 5wt% of the whole composition or more) is accompanied by an equal or greater volume of the said organic solid;
the said composition remaining in an immobile solid form on heating at least up to 50°C, preferably at least up to 70°C.
[0029] Using a Sommer and Runge PNR10 with a standard needle, a total applied weight of 50 gm and a time of 10 seconds, we have found that satisfactory products in this category are not substantially harder than toilet soap and may be softer. Penetration depth is at least 1.5 mm and can be as great as 4mm. This compares with 1.3 to 1.7 mm for toilet soap and about 0.5 mm for non-soap detergent laundry bars.
[0030] An essential component of compositions in this category is nonionic surfactant. The amount of nonionic surfactant should not exceed 45% by weight of the total composition. Preferably, it is included in an amount of 10 to 30% by weight.
[0031] Generally, nonionic surfactant serves as a binder in the composition as well as providing detergency. It is desirable for binder in the composition to be liquid and it is therefore convenient for the nonionic surfactant to be liquid at room temperature or become liquid below 30°C.
[0032] Soap is a mixture of liquid and crystalline solid phases, consequently if soap is present it makes a contribution to the liquid phase of the composition. Consequently, if soap is present, it may be possible to use less nonionic surfactant than would otherwise be necessary to obtain a coherent extrudable composition. Adjusting the quantity of nonionic surfactant to give a satisfactory composition tends to be less critical when soap, wax or other organic solid is present than if they are absent. It is possible to include some organic solvent, especially hydrocarbon solvent, to assist in removing oily soils. This contributes liquid. However, it is then desirable to package the product in a way which blocks evaporation of solvent.
[0033] As mentioned, it is convenient to use a liquid nonionic surfactant. However, it may be possible to obtain a satisfactory composition if the nonionic surfactant melts so as to be liquid at a processing temperature in the range 25°C to 50°C, especially if it is liquid at a temperature of use, e.g. if use is in a tropical climate.
[0034] It may be possible to use a solid nonionic surfactant if organic solvent is included in the composition and the nonionic surfactant and organic solvent together form a liquid organic phase.
[0035] It is desirable to include nonionic surfactant for the sake of its good detergency against oily soils. Other classes of surfactant such as cationic or anionic surfactants may also be included in the compositions.
[0036] If a higher foam profile is desired than can be achieved with nonionic surfactants, it may be of advantage to include a nonionic-anionic surfactant combination comprising in addition to a nonionic surfactant up to 20% or more (by weight of the whole composition) of a high-foaming anionic surfactant such as e.g. sodium alkyl benzene sulphonate. Preferably the amount of anionic surfactant does not exceed 10% by weight of the composition.
[0037] Nonionic surfactant will usually be present in a greater amount than other synthetic surfactants. Preferably the total quantity of synthetic surfactants is not over 40 wt%, more preferably not over 30 wt%, of the composition.
[0038] It is preferred that the bleach employed in these extrudable compositions is an inorganic peroxy bleach, notably perborate, percarbonate or monopersulphate. Surprisingly it has been found that in these compositions these bleaches have superior stability to the organic peracid diperoxydodecanoic acid (DPDA).
[0039] The filler component of the composition serves as a carrier for the bleach and surfactant. Preferably the total quantity of filler is between 40 and 70wt% of the composition. As is apparent from the weight percentage ranges given above, the filler may be clay, soap, wax, other organic solid or any mixture of these or it may be another inorganic filler together with organic filler and optionally clay as well.
[0040] Surprisingly, it has been found that inorganic materials commonly used as filler (other than clay) give compositions which are insufficiently coherent, cannot be extruded and lead to insufficient transfer of the detergent composition to a fabric which is being pretreated. However these problems can be overcome if the inorganic filler is accompanied by an equal or greater volume of organic filler. Clay, which may be kaolin clay, can be used without or with organic filler present but it is preferred to have some organic filler present because the amount of nonionic surfactant is then less critical.
[0041] Inorganic materials other than clay which may be used as filler include talc, calcite and sodium sulphate.
[0042] Soap, if used, may be any of the materials normally classed as soap. Generally it will be alkali metal salt of C₁₂ to C₂₀ fatty acids. Sodium salts will normally be used. The soap may in particular be based on mixed acids such as 80/20 tallow/coconut soap.
[0043] If soap is used in any substantial amount, it is strongly preferred that the soap should have a water content of not more than 5% by weight of the soap.
[0044] If wax or any organic solid other than soap or wax is used in any substantial amount, it is strongly preferred that it should have a melting point over 50°C. Organic solids other than soap or wax are desirably wax-like materials capable of plastic flow under conditions of processing. Examples of suitable waxes and other organic solids are paraffin wax, caster wax, glycerol monostearate and fatty alcohols.
[0045] Compositions of this type can include the optional components mentioned above, including solvents, enzymes, bleach stablisers.
[0046] These extrudable compositions may be prepared by mixing the constituents together to a homogeneous mixture and extruding the mixture through a die to produce a rod which is cut into short lengths or sticks, which is the preferred form of shaped article.
[0047] Such a stick is the preferred form of shaped article, but the compositions may conceivably be moulded into other shapes. Sticks may be wrapped for storage and sale or may be fitted into a screw-up or a push-up stick holder.
[0048] When mixing the constituents any wax or solid nonionic surfactant is preferably melted before it is added, or is dissolved in liquid nonionic surfactant and added with the latter. It is preferred to add bleach least.
[0049] For use, the composition is rubbed onto stains and spots on fabric that has been previously dampened with water. The fabric is then subjected to a normal laundering process. Best results are obtained if some time, for example about 5 minutes, is allowed to elapse in order to give the composition time to act on the spot or stain prior to the normal laundering process.
Castable Compositions
[0050] Compositions in another category are solid at room temperature but melt on heating and so can be cast to shape in a mould. Two types of castable compositions are preferred.
Type (i) - containing non-ionic surfactant
[0051] These compositions melt at a temperature above 40°C, preferably in the range from 50°C to 90°C, and contain
5 to 70 wt% of nonionic surfactant
1 to 20 wt% of peroxygen bleach, and
10 to 80 wt% of one or more organic compounds, which compound or mixture of compounds melts to a mobile state at a temperature above 40°C.
[0052] Using a Sommer and Runge PNR10 penetrometer with a standard 9° cone, a total applied weight of 50 grams and a time of 60 seconds, we have found that satisfactory products of this type are somewhat softer than toilet soap. Penetration depth for toilet soap is 1 to 2 mm under similar conditions, whereas that for non-soap detergent laundry bars is about 0.5 mm.
[0053] The actual amount of the nonionic surfactant is not very critical. It can be included in amounts ranging from 5% up to 70% or 75% by weight of the total composition. Preferably, it is included in an amount of 10 to 50% by weight, more preferably 20 to 40%.
[0054] It is possible to employ nonionic surfactant which is either liquid or solid at room temperature of say 20°C. If solid nonionic surfactant is employed it is desirable that it should melt or dissolve in the composition at the temperature of processing. It would be desirable for nonionic surfactant, if used, to melt at a temperature not over 50°C.
[0055] It is desirable to include nonionic surfactant for the sake of its good detergency against oily soils. Other classes of surfactant such as cationic or anionic surfactants may also be included in compositions of this invention.
[0056] If a higher foam profile is desired than can be achieved with nonionic surfactants, it may be of advantage to include a nonionic-anionic surfactant combination comprising in addition to a nonionic surfactant up to 30% (by weight of the whole composition) of a high-foaming anionic surfactant such as e.g. a sodium alkyl benzene sulphonate. The amount of anionic surfactant may perhaps be not over 10% by weight of the composition.
[0057] Nonionic surfactant will usually be present in a greater amount than other synthetic surfactants. Preferably the total quantity of synthetic surfactants is not over 50wt%, better 10 to 40 wt% of the composition.
[0058] The bleach employed in the compositions of this type is preferably perborate, percarbonate or monopersulphate.
[0059] The organic bleach diperoxydodecanioc acid (DPDA) is not particularly stable in the compositions of this type and gives poor performance. Consequently it is preferred not to use this material.
[0060] The third essential component of the compositions of this type is the organic compound or mixture of compounds which melts at a temperature above 40°C and serves as a carrier for the other components. It is preferably present as 10 to 30wt% of the composition.
[0061] Various organic compounds may be used, the main requirement being a suitable melting point. Possible materials are waxes such as paraffin wax and castor wax, polyalkylene glycol esters, fatty alcohols and fatty acids. Such alcohols or acids may have 12 to 20 carbon atoms.
[0062] Fatty alcohols have the advantage of being cheaper than polyalkylene glycol esters, and can be used in smaller quantities than waxes. Fatty acids are even cheaper, but need to be accompanied by sufficient alkaline salts that an alkaline pH is obtained in use. This is also required for optimum performance of the preserved inorganic peroxygen bleaches. A preferred amount of fatty alcohol or fatty acid is 15 to 40wt% of the composition.
[0063] In a preferred method of preparation, the first step is that the organic compound/mixture of compounds and the synthetic surfactant(s) are mixed and heated up to between about 70 and 100°C. Subsequently, the peroxygen bleach, optionally followed by the precursor, is added while continuously stirring until a homogeneous mix is obtained. After preparation, the compositions are cast and solidified to the desired shape by cooling to ambient temperature.
Type (ii) - Soap Coagels
[0064] These preferred compositions also melt at a temperature above 40°C, preferably in the range from 45°C to 90°C and contain
1 to 20wt% of peroxygen bleach,
5 to 40wt% of soap, and
15 to 70 wt% of a polyhydric alcohol.
[0065] Using a Sommer and Runge PNR10 penetrometer with a standard 9° cone, a total applied weight of 50 grams and a time of 60 seconds, we have found that satisfactory products of this type are somewhat softer than toilet soap. Penetration depth is normally over 5mm, and can be as high as 14mm. Penetration depth for toilet soap is 1 to 2 mm under similar conditions, whereas that for non-soap detergent laundry bars is about 0.5mm.
[0066] In the compositions of this type the soap and polyhydric alcohol components form a gel (a so-called soap coagel) which is of immobile solid form and acts as a carrier for the bleach and any other components.
[0067] The soap may be any of the normal materials classed as soap, but it is strongly preferred to employ saturated soap. Thus it will generally be an alkali metal salt of C₁₂ to C₂₀ fatty acid(s). Sodium salts will normally be used. The soap may in particular be sodium stearate or sodium palmitate or may be based on mixtures of saturated soaps. It is strongly preferred that the soap contain less than 5% by weight of moisture.
[0068] The polyhydric alcohol may itself be solid or liquid. Possible polyhydric alcohols are propane-1,2-diol, other diols, triols, and polyols, e.g. ethyleneglycol, diethyleneglycol, sorbitol, butane diol and triethanolamine. A diol may well have not more than six carbon atoms. A higher polyol may well not have more than twelve carbon atoms.
[0069] The polyhydric alcohol will preferably be aliphatic and substantially non-volatile, having a boiling point of 120°C or above. The ratio of soap to polyhydric alcohol will generally lie in the range 1:1 to 1:9, preferably 1:1.5 to 1:5 and more preferably 1:2.5 to 1:4.
[0070] It is preferred that the peroxygen bleach is monopersulphate. Surprisingly, this beach provides a better combination of stability and performance than other peroxygen bleaches. Monopersulphate may be used in the form of the commercially available triple salt which contains KHSO₅ : KHSO₄ : K₂SO₄ in the molar ratio of about 2:1:1.
[0071] A preferred amount of monopersulphate is 4 to 10 wt% of the triple salt based on the whole composition.
[0072] Percarbonate is stable in the preferred compositions of this invention, but gives poor bleaching performance. If the organic peroxyacid precursor tetracetylethylenediamine (TAED) is included to improve bleaching performance, the stability of the percarbonate is reduced. Perborate tends not to be stable in the preferred compositions of this invention.
[0073] It is desirable that compositions of this type should also include synthetic (i.e. non-soap) surfactants which may for example be anionic, cationic or nonionic. The latter are preferred in order to enhance the ability of the composition to remove oily soils. They may be employed either alone or in combination with other types of surfactants.
[0074] If a higher foam profile is desired than can be achieved with nonionic surfactants, it may be of advantage to include a nonionic-anionic surfactant combination comprising in addition to a nonionic surfactant up to 20% or more (by weight of the whole composition) of a high-foaming anionic surfactant such as e.g. a sodium alkyl benzene sulphonate. The amount of anionic surfactant may perhaps be not over 10% by weight of the composition.
[0075] The actual amount of the synthetic surfactant is not very critical. It can be included in amounts of up to 50% by weight of the total composition, possibly somewhat above this. Preferably, it is included in an amount to 20 to 50% by weight of the composition, of which at least part is preferably nonionic surfactant. Preferably nonionic surfactant provides 10 to 50 wt% more preferably 15 to 40 wt% of the composition.
[0076] When nonionic surfactant is used, it may be liquid or solid at room temperature of say 20°C. If solid nonionic surfactant is employed it is desirable that it should melt or dissolve in the composition at the temperature of processing. It would be desirable for solid nonionic surfactant, if used, to melt at a temperature not over 50°C.
[0077] In a preferred method of preparation of compositions of this type, firstly the polyhydric alcohol and any nonionic synthetic surfactant are mixed and heated to above 80°C. The soap is dissolved in this and other materials are then added, possibly at slightly lower temperatures, while continuously stirring until a homogeneous mix is obtained. Preferably the bleach is added last. After preparation, the compositions are cast and solidified to the desired shape by cooling to ambient temperature.
Both castable types
[0078] Both of the above types of castable composition can contain some organic solvent possibly in an amount which is 4 to 15 wt% of the composition. They can also include other optional components mentioned initially such as enzynes.
[0079] Inclusion of solvent may give rise to some syneresis - weeping of liquid form the solid composition. This can be countered by including anionic surfactant, notably di C₆ to C₁₂ alkylsulphosuccinate or linear C₈ to C₁₈ alkylbenzene sulphonate.
[0080] Hydrocarbon solvent and anionic surfactant may for example be employed in amounts which are both 4 to 15 wt% of the composition and in a weight ratio of 2:1 to 1:2 preferably 1.5:1 to 1:1.5.
[0081] The compositions may include some inorganic particulate filler, such as clay or talc, in addition to the possible other inorganic materials mentioned above. This may desirably be included in only small amounts such as not more than 5 wt% of the composition or may be in greater amounts, say up to 20 wt%.
[0082] When the compositions are cast, at a temperature which is typically 50° to 70°C, it is desirable that the viscosity of the liquid is high enough to retain the solids in suspension. For this reason it is usually advisable to pour the sticks at a temperature just above the gel point. It is also possible to add a thickening agent to the mix to increase the viscosity e.g. hydroxypropyl cellulose derivatives.
[0083] The compositions may be cast and solidified to any desired shape, but preferably are cast into sticks suitable for application in screw-up or push-up stick holders, thereby providing the customer with a very convenient product form. For this purpose, the composition can simply be cast in the stick holder without the need of any lubricant. Alternatively the product can be in the form of a stick with a wrap-around covering.
[0084] For use, these castable compositions can be rubbed onto stains and spots on either dry fabric or fabric that has been dampened with water. Following either mode of application the fabric is then subjected to a normal laundering process. Direct application to a dry fabric is usually more convenient for the user. When applied to a dry fabric, the composition acts on the spot or stain during an early part of the normal laundering process and is removed during a later part of the laundering process. When applied to a fabric already dampened with water best results are obtained if some time, for example about 5 minutes, is allowed to elapse in order to give the composition time to act on the spot or stain prior to the normal laundering process.
[0085] Embodiments of the invention will now be described by way of example only, with reference to the following Examples wherein:
[0086] Nonionic surfactant, when used, was C₁₃ to C₁₅ fatty alcohol, ethoxylated with average 7 EO. Soap, when used, was 80/20 tallow/coconut soap dried to less than 5wt% moisture.
[0089] Monopersulphate was added in the form of the commercially available triple salt containing KHSO₅, KHSO₄ and K₂SO₄ with a molar ratio of approximately 2:1:1.
[0090] Dequest 2041 is ethylene diamine tetramethylene phosphonic acid, which is a sequestering agent.
Example 1
[0092] Detergent pretreatment sticks were made with extrudable formulations set out in Table 1, in which the stick ingredients are given in weight percentage amounts with respect to the final stick composition.
[0093] Each composition was prepared by mixing its components in a Z-blade mixer at a temperature of 30 to 50°C.
[0094] The bleach was added at the last stage, after thoroughly mixing the other components. Where a wax was included in the formulation, this was either melted by heating before addition to the mix or dissolved by heating it in the nonionic surfactant, and adding the two together.
[0095] When a homogeneous mix had been achieved, it was extruded from a screw extruder through an orifice of circular cross-section approximately 3cm in diameter.
TABLE 1
| %w/w | ||||||||||
| A | B | C | D | E | F | G | H | J | K | |
| Nonionic (C13/15, 7EO) | 27-29 | 28.0 | 26.6 | 14 | 21 | 15.8 | 22 | 20 | 8.4 | 6 |
| Alkylbenzene sulphonate | - | - | - | - | - | - | - | - | 17.8* | 30 |
| Soap | - | - | - | 55 | - | 35 | 3 | 12 | - | 42 |
| Paraffin wax (Mpt 60-65°C) | - | - | - | - | - | - | 3 | - | - | - |
| Castor wax | - | - | - | - | 5 | - | - | - | - | - |
| Kaolin | 45.6 | 44.1 | - | - | 47 | - | 46 | 47 | 40.6 | - |
| Talc | - | - | - | - | - | 28.3 | - | - | - | - |
| Calcite | - | - | 46.9 | - | - | - | - | - | - | - |
| Na pyrophosphate (tetra) | 10 | 9.7 | 10.2 | 10 | - | 8.3 | - | - | 5.0 | 6 |
| Na orthophosphate (tri) | - | - | - | - | 6 | - | 6 | 8.6 | - | - |
| Sodium carbonate | - | - | - | 9 | 9 | - | 8 | - | 10.4* | 8 |
| Perborate monohydrate | 12 | 11.6 | 12.2 | - | - | - | - | - | 12 | - |
| TAED | 4 | 3.9 | 4.1 | - | - | - | - | - | 4 | - |
| K monopersulphate triple salt | - | - | - | 12 | 11.6 | 12.2 | 12 | - | - | 8 |
| Na percarbonate | - | - | - | - | - | - | - | 12 | - | - |
| Dequest 2041 | 0.4 | 0.4 | - | - | 0.4 | 0.3 | - | 0.4 | 0.4 | - |
| Water | - | 2.4 | - | - | - | - | - | - | 1.5* | - |
| Bleach stability (half life at 40°C in days) | >40 | 10 | n.t | >40 | 20 | >100 | >100 | 20 | >40 | >100 |
| n.t = not tested | ||||||||||
| * = added as pre-made noodle |
[0096] Each of the formulations except C, was extrudable in solid stick form. The extruded sticks were stored at 40°C to represent storage in a warm climate. After periods of time the remaining bleach activity was tested by means of a titration for available oxygen, and the bleach half life thereby determined. The half lives so determined are stated in Table 1.
[0097] Composition B contained a small quantity of water, added as such during preparation of the composition. As can be seen by comparison with composition A, this water in B was severely detrimental to beach stability.
[0098] Composition J was prepared using a previously made noodle containing the alkylbenzene sulphonate, sodium carbonate and the water, as water of hydration of the carbonate. Consequently there was no free water, and the bleach stability was good. Composition K was prepared using a grade of alkylbenzene sulphonate with low moisture content.
EXAMPLE 2
[0099] The performance of composition A of Example 1, using freshly prepared sticks, was assessed as follows:-
[0100] An area 4cm x 4cm was marked out on piece of test cloth (approx 7cm x 7cm size). The test pieces were wet with a minimum amount of water, then 0.1g product was applied over the marked 4 x 4cm area. After pre-treatment the test pieces were left for 10 minutes then washed in a tergotometer using a wash solution containing 1g/litre detergent powder for 10 mins at 25°C. A control test piece (no pretreatment) was included in the tergotometer wash. The test pieces and control were rinsed, and the reflectance at 460nm was compared with that before pre-treatment and washing.
[0101] The pretreatment results are given in Table 2. Composition A gave clear pretreatment benefits against all stains except blood.
EXAMPLE 3
[0102] The performance of compositions F and G against tea-stained cloth was assessed by a similar procedure to Example 2. A 39cm² area was wet with the minumum amount of water and 0.15 to 0.2g of the product was applied to it. After this pre-treatment the test piece was left for 10 minutes then washed in a tergotometer using a wash solution containing 2g/litre detergent powder at 25°C. A test piece treated with soap was used as control. The test pieces were allowed to soak in the wash solution for 2 minutes and then washed with normal agitation for 10 minutes. The test pieces and control were rinsed, and the reflectance at 460nm was compared with that before pre-treatment and washing. Increases in reflectance were:-
| Composition F | 17.9 |
| Composition G | 27.5 |
| Soap | < 1 |
[0103] Composition K of Example 1 was tested by a similar procedure, using test cloths with various stains. After pretreatment the test pieces were left for only 2 minutes and the final wash used a solution of 1g/litre detergent powder. Increases in reflectance at 460nm are given in Table 3 below.
EXAMPLE 4
[0104] Detergent pretreatment sticks were made from castable compositions according to the formulations contained in Table 4, in which the stick ingredients are given in weight percentage amounts with respect to the final stick composition.
[0105] To prepare each composition, an organic substance having a melting point above 40°C was heated and mixed with a nonionic detergent until the organic substance melted to give an isotropic liquid. The other components of the formulation were then added, with good mixing to retain the solids in suspension. The mixture was cooled to just above its set-point, and then poured into moulds.
[0106] When a hydrocarbon solvent was included in the formulation, it was added at a temperature of not more than 80°C. The bleach was added last at a temperature below 70°C.
[0107] All the compositions gave sticks of solid form that were strong enough to allow the composition to be rubbed by hand onto fabric.
[0108] The compositions were stored at 40°C to represent storage in a warm climate. At intervals, remaining bleach activity was determined by means of a titration for available oxygen. From these results the bleach half life was calculated, and is shown in Table 4.
TABLE 4
| %w/w | |||
| 4A | 4B | 4C | |
| Nonionic (C13/15 - 7EO) | 29 | 25.2 | 35 |
| Stearyl Alcohol | 20 | 21.0 | - |
| Stearic acid | - | - | 30 |
| Castor wax | 8 | 8.4 | - |
| Talc | 17 | 5.2 | 7 |
| Hydrocarbon solvent mainly isododecane | 5 | 11.8 | - |
| Sodium dioctyl sulphosuccinate | - | 8.2 | - |
| Perborate monohydrate | 12 | 12.0 | - |
| TAED | 4 | 4.0 | - |
| Na pyrophosphate (tetra) | 5 | 4.0 | 20 |
| K monopersulphate (triple salt) | - | - | 8 |
| Bleach half life at 40°C, days | >40 | >40 | not tested |
EXAMPLE 5
[0109] The performance of composition 4A of Example 4 was assessed using freshly prepared sticks, by the procedure of Example 2.
[0110] The pretreatment results are given in Table 5. Composition 4A gave clear pretreatment benefits against all stains except blood.
EXAMPLE 6
[0111] A stick similar to that of Composition 4B was prepared incorporating the organic bleach, diperoxydodecanoic acid (DPDA). To provide an acidic composition, because DPDA is unstable under alkaline conditions, disodium dihydrogen pyrophosphate was used as a hydratable salt. The composition contained:-
| %w/w | |
| Nonionic (C13/15 - 7EO) | 27 |
| Stearyl Alcohol | 22.5 |
| Castor wax | 9 |
| Talc | 9.9 |
| Hydrocarbon solvent mainly isododecane | 12.6 |
| Sodium dioctyl sulphosuccinate | 9 |
| Disodium dihydrogen pyrophosphate | 5 |
| DPDA (26% active) | 5 |
EXAMPLE 7
[0112] Pretreatment sticks were made from castable soap coagel formulations set out in Table 6 below. In this Table the stick ingredients are given in weight percentage amounts with respect to the final stick composition.
[0113] To make each of these compositions the liquid glycol and nonionic detergent were heated and mixed at a temperature of more than 80°C, typically up to 105°C. Dry soap (sodium stearate or palmitate) in a finely divided form was added and stirred until dissolved. Any hydrocarbon solvent was added after cooling to 70-80°C followed by finely divided inorganic solids. Bleach was added last at a temperature of 60-70°C. When the solids were homogeneously dispersed in the liquid it was poured into moulds and allowed to solidify. At the temperature at which the sticks are poured, typically 50-70°C, the viscosity of the liquid was high enough to retain the solids in suspension.
[0114] The proteolytic enzyme was the material sold as "Alcalase 2-5 SL" by Novo Industri A/S, Denmark.
[0115] All the compositions gave sticks of solid form that were strong enough to allow the composition to be rubbed by hand onto fabric. Composition 7F showed some phase separation, seen as a beading of liquid on the surface of the gel. This was avoided by the inclusion of an anionic surfactant in formulations 7D and 7E.
[0116] The compositions were stored at 40°C to represent storage in a warm climate. At intervals remaining bleach activity was determined by means of a titration for available oxygen. From these results the bleach half life was calculated, and is shown in Table 6. It will be seen from the table that formulations containing monopersulphate show excellent bleach stability. Percarbonate also gives good stability but perborate and mixtures of percarbonate with TAED were of poor stability.
TABLE 6
| %w/w | |||||||||
| 7A | 7B | 7C | 7D | 7E | 7F | 7G | 7H | 7J | |
| Propane 1,2 diol | 30 | 30 | 30 | 25.8 | 25.7 | 28 | 30 | 30 | 36.8 |
| Nonionic surfactant (C13/15, 7 EO) | 38 | 38 | 38 | 31.8 | 34.2 | 36.4 | 38 | 38 | 4.6 |
| Sodium stearate | - | - | - | 8.6 | 8.6 | 9 | - | - | 15.6 |
| Sodium palmitate | 9 | 9 | 9 | - | - | - | 9 | 9 | - |
| Dioctyl sodium sulfosuccinate | - | - | - | 7.0 | 8.6 | - | - | - | - |
| Alkylbenzene sulphonate | - | - | - | - | - | - | - | - | 23.0 |
| Hydrocarbon solvent principally isododecane | 5 | 5 | 5 | 8.6 | 8.6 | 8.6 | 5 | 5 | - |
| Talc | - | - | - | 3.0 | - | 3.0 | - | - | 5.0 |
| Tetrasodium pyrophosphate | - | - | - | 3.0 | - | 3.0 | - | - | 3.0 |
| Soda ash | 6 | - | 6 | 4.0 | 6.0 | 4.0 | 6 | - | 4.0 |
| Sodium perborate monohydrate | - | - | 12 | - | - | - | - | - | - |
| Potassium monopersulphate triple salt | - | - | - | 8.0 | 8.0 | 8.0 | 12 | - | 8.0 |
| Sodium percarbonate | 12 | 12 | - | - | - | - | - | - | - |
| Borax 5H₂O | - | - | - | - | - | - | - | 6 | - |
| Diperoxydodecane dioic acid* | - | - | - | - | - | - | - | 12 | - |
| Proteolytic enzyme | - | - | - | - | 0.5 | - | - | - | - |
| TAED | - | 6 | - | - | - | - | - | - | - |
| Bleach stability (half life at 40°C in days) | >40 | 6 | 3 | >40 | >40 | n.t | >40 | <1 | >100 |
| n.t = not tested | |||||||||
| * = 26% active, balance was sodium sulphate |
EXAMPLE 8
[0117] The performance of compositions 7C and 7E of Example 7 was assessed using freshly prepared sticks, by the procedure of Example 2. The performance of a composition Q without bleach was also assessed. This composition contained
| Glycerol | 25wt% |
| Nonionic surfactant | 30wt% |
| Sodium stearate | 10wt% |
| Hydrocarbon solvent (mainly isododecane) | 20wt% |
| Talc | 9.5wt% |
| Borax 5H₂O | 5wt% |
| Proteolytic enzyme | 0.5wt% |
[0118] The pretreatment results are given in Table 7. Composition 7C gave clear pretreatment benefits against all stains except blood, where compositions 7E and Q which contain enzyme gave a positive benefit.
EXAMPLE 9
1. A detergent composition in the form of a solid, shaped article suitable for application
to selected areas of textile articles prior to laundering, the composition being not
substantially harder than toilet soap, and characterised by including a peroxygen
bleach and a hygroscopic salt having a hydrate which is stable above 30°C.
2. A detergent composition according to claim 1 which melts to a mobile state above
40°C, and can be shaped by casting.
3. A detergent composition according to claim 1 which is an extrudable composition
containing a filler selected from clay, soap and non-surfactant organic solids.
4. A detergent composition according to claim 1, claim 2 or claim 3 comprising
1 to 20 wt% peroxygen bleach
2 to 15 wt% hygroscopic salt (reckoned as anhydrous) having a hydrate stable above 30°C
5 to 70 wt% surfactant
and having a free water content of not more than 0.5 wt%.
1 to 20 wt% peroxygen bleach
2 to 15 wt% hygroscopic salt (reckoned as anhydrous) having a hydrate stable above 30°C
5 to 70 wt% surfactant
and having a free water content of not more than 0.5 wt%.
5. A detergent composition in the form of a solid, shaped article and comprising
5 to 45 wt% of nonionic surfactant
1 to 20 wt% of a peroxygen bleach
2 to 15 wt% of at least one hygroscopic salt having a hydrate stable above 30°C,
at least 10 wt% of a filler material selected from one or more of
0 to 70 wt% (based on the whole composition) of an organic filler which is soap, wax and/or other soft organic solid
0 to 50 wt% (based on the whole composition) of clay
0 to 40 wt% (based on the whole composition) of an inorganic particulate filler other than clay,
with the proviso that any inorganic filler which is other than clay and present in excess of 5 wt% of the whole composition is accompanied by an equal volume of the said organic solid;
the said composition remaining in an immobile solid form on heating at least up to 50°C.
5 to 45 wt% of nonionic surfactant
1 to 20 wt% of a peroxygen bleach
2 to 15 wt% of at least one hygroscopic salt having a hydrate stable above 30°C,
at least 10 wt% of a filler material selected from one or more of
0 to 70 wt% (based on the whole composition) of an organic filler which is soap, wax and/or other soft organic solid
0 to 50 wt% (based on the whole composition) of clay
0 to 40 wt% (based on the whole composition) of an inorganic particulate filler other than clay,
with the proviso that any inorganic filler which is other than clay and present in excess of 5 wt% of the whole composition is accompanied by an equal volume of the said organic solid;
the said composition remaining in an immobile solid form on heating at least up to 50°C.
6. A detergent composition according to claim 5 containing 40 to 70 wt% filler, at
least part of which is clay.
7. A detergent composition in the form of a solid shaped article melting at a temperature
above 40°C, the composition comprising
5 to 70 wt% of nonionic surfactant
1 to 20 wt% of peroxygen bleach
2 to 15 wt% of at least one hygroscopic salt having a hydrate stable above 30°C, and
10 to 80 wt% of one or more organic compounds which compound or mixture of compounds melts to a mobile state at a temperature above 40°C.
5 to 70 wt% of nonionic surfactant
1 to 20 wt% of peroxygen bleach
2 to 15 wt% of at least one hygroscopic salt having a hydrate stable above 30°C, and
10 to 80 wt% of one or more organic compounds which compound or mixture of compounds melts to a mobile state at a temperature above 40°C.
8. A detergent composition according to claim 7 wherein said organic compound or mixture
of compounds is selected from waxes, polyalkylene glycol esters, fatty alcohols having
from 12 to 20 carbon atoms and fatty acids having 12 to 20 carbon atoms.
9. A detergent composition according to any one of the preceding claims wherein the
peroxygen bleach is selected from the group consisting of perborate, percarbonate
and monopersulphate.
10. A detergent composition in the form of a solid shaped article melting at a temperature
above 40°C the composition including
1 to 20 wt% of peroxygen bleach
5 to 40 wt% of soap
15 to 70 wt% of a polyhydric alcohol, and
2 to 10 wt% of a hygroscopic salt having a hydrate stable above 30°C.
1 to 20 wt% of peroxygen bleach
5 to 40 wt% of soap
15 to 70 wt% of a polyhydric alcohol, and
2 to 10 wt% of a hygroscopic salt having a hydrate stable above 30°C.
11. A detergent composition according to claim 10 wherein the peroxygen bleach is
monopersulphate.