IE43532B1 - Detergent compositions - Google Patents

Abstract

1530799 Powdered alkaline detergent composition for fabrics UNILEVER Ltd 26 Aug 1976 [28 Aug 1975] 35545/75 Heading C5D A powdered alkaline fabric washing detergent composition comprises 5-30 wt. per cent of a synthetic anionic, non-ionic, amphoteric or zwitterionic detergent compound or a mixture thereof, 10-30 wt. per cent of mixed alkali metal tripolyphosphate and alkali metal orthophospate in the wt. ratio of from 10:1 to 1:5, there being at least 5 wt. per cent of tripolyphosphate, and not more than 5 wt. per cent of alkali metal pyrophosphate, which is preferably absent. The pH of a 0À1% aqueous solution of the composition is in the range 9-11. Soap, preferably 0À5-25 wt. per cent of C 10-24 fatty acids at least half being C 16 or over, may also be present. Preferred detergent compounds are synthetic anionic and nonionic compounds. The former are usually water soluble alkali metal salts of organic sulphates and sulphonates having C 8 -C 22 alkyl radicals, including the alkyl portion of higher acyl radicals. Suitable non-ionic compounds include the reaction products of alkylene oxides with alkyl phenols, the condensation products of aliphatic primary or secondary alcohols with ethylene oxide, the condensation products of ethylene oxide with the reaction products of propylene oxide and ethylenediamine, long chain tertiary amine oxides, long chain tertiary phosphine oxides, and dialkyl sulphoxides. Optional ingredients include lather boosters such as alkanolamides, lather depressants such as alkyl phosphates and silicones, anti-redeposition agents such as sodium carboxymethyl cellulose and polyvinyl pyrrolidone, oxygen-releasing bleaching agents such as sodium perborate, preferably in amount of 10-40 wt. per cent, and sodium percarbonate, peracid bleach precursors, chlorine-releasing bleaching agents such as trichloroisocyanuric acid and alkali metal salts of dichloroisocyanuric acid, fabric softening agents, inorganic salts such as sodium sulphate, sodium carbonate, and magnesium silicate, enzymes such as proteases and amylases, perfumes, fluorescent agents, germicides, and colorants. Other optional ingredients include an antideposition agent, preferably 0À1-5 wt. per cent, for example a salt of a homo- or copolymer of acrylic acid or a substituted acrylic acid, preferably a sodium polyacrylate having a MW of 10,000-50,000, or a copolymer of maleic anhydride with ethylene, vinyl methyl ether, or styrene, or sodium salts of polymaleic acid and polyitaconic acid, phosphate esters of ethoxylated aliphatic alcohols, polyethylene glycol phosphate esters, and certain phosphonates, which last may be mixed with protective colloids such as gelatine. Alkali metal silicates, preferably 5-15 wt. per cent of sodium neutral or alkaline silicate, may also be present. Minor amounts of non-phosphate detergency builders, which may be either precipitant or sequestrant builders, may be present, for example amine carboxylates such as sodium nitrilotriacetate, sodium aluminosilicate ion-exchange materials, sodium citrate, and soap.

Description

The invention relates to powdered detergent compositions which are adapted for fabric washing, and in particular to such compositions containing synthetic detergent active compounds together with phosphate detergency builders.

The most commonly used detergency builders are the condensed phosphates, especially sodium tripolyphosphate, hut it has been suggested that the use of phosphate detergency builders can contribute to eutrophication problems. There have been very many suggestions for alternative, mainly organic, materials to he used as detergency builders instead of the condensed phosphates, hut most of these materials tend to he unsatisfactory for one reason or another, for example they are less efficient or biologically unacceptable, or they may simply he too expensive.

It has also been proposed to mitigate the problems of eutrophication by using decreased levels of condensed phosphate detergency builders, with or without the presence of other detergency builders, hut few of these proposals have approached commercial acceptance. Thus, when reduced levels of sodium tripolyphosphate are used without supplemental builders, there can he considerable problems when using the compositions in hard water if there is insufficient phosphate to sequester all the calcium ions present, as..this causes the precipitation of insoluble calcium phosphate salts which can he deposited on the washed fabrics, besides giving decreased detergency due to inadequate softening of the water sometimes accompanied by precipitation of insoluble calcium salts of anionic detergent compounds . 43533 On the other hand, when a condensed phosphate builder is used with some non-phosphate detergency builders, the former may prevent the latter from functioning effectively, especially in the case of other detergency builders which act by precipitating the calcium salt, for example sodium carbonate. Moreover, there are relatively few other detergency builders which are completely environmentally acceptable and which are good enough to he worth using even in part replacement for a condensed phosphate builder.

In recent years a lot of effort and expense has been directed to solving these problems, with the synthesis and evaluation of great numbers of new materials. However, it would inevitably take several years for any completely new material to he cleared for domestic use, and therefore most recent interest has centered on known non-phosphate materials which act as builders hy either sequestration, precipitation or ion-exchange and which are known to he environmentally safe.

The present invention resides in the surprising discovery that specific mixtures of the well known phosphate detergency builders can themselves he chosen to give good fabric washing detergencies at relatively low phosphorus levels. As mixtures of such phosphates are in general well known in detergent products, especially in products other than for fabric washing, it is surprising that this benefit has not been previously noticed and its importance understood. In a preferred aspect the invention enables satisfactory detergent products to be formulated at relatively low phosphate levels without the use of supplementary non-phosphate builders.

/... According to the present invention, a powdered alkaline fabric washing detergent composition comprises from 5% to 30% of a synthetic anionic, nonionic, amphoteric or zwitterionic detergent compound or a mixture thereof, and from 10% to 30% of mixed alkali metal tripolyphosphate and alkali metal orthophosphate in the ratio of from 10:1 to 1:5 parts by weight, wherein the amount of alkali metal tripolyphosphate is at least 5%, and the amount of any alkali metal pyrophosphate is not more than 5%, all these percentages being by weight of the total detergent composition, and the pH of a 0.1% aqueous solution of the composition is from 9 to 11.

The invention includes a process for making these detergent compositions. By the suitable choice of the amounts of the alkali metal tripolyphosphate and alkali metal orthophosphate it is possible to formulate effective detergent compositions containing lower phosphorus levels than in comparable conventional sodium tripolyphosphate-based detergent compositions with similar detergency building capabilities. Insofar as the two essential detergency builder materials function; normally in different ways, i.e. by alkali metal tripolyphosphates acting as sequestrant detergency builders and by alkali metal orthophosphates functioning as precipitant builders, it is somewhat surprising that a mixture of the materials functions so effectively. In particular, when alkali metal orthophosphates are used as detergency builders, they normally tend to cause inorganic deposition which promotes soil redeposition on the washed fabrics, but in the presence of the alkali metal tripolyphosphate the S 5 3 3 soil redeposition is significantly decreased, but not by inhibiting the calcium orthophosphate precipitation which would detract from the detergency benefit. Moreover, in comparison with the use of sodium tripolyphosphate alone as detergency builder, the same amount of the mixed alkali metal tripolyphosphate and alkali metal orthophosphate shows improved detergency building capacity and low soil redeposition properties.

The alkali metal orthophosphate used is either potassium or preferably sodium orthophosphate, as the latter is cheaper ]_0 and more readily available. Normally the tri-alkali metal salts are used, but orthophosphoric acid or the di- or monoalkali metal salts, e.g. disodium hydrogen orthophosphate or monosodium dihydrogen orthophosphate could be used if desired to form the compositions. In the latter event other more alkaline salts would also be present to maintain a high pH in the end product, with full neutralisation to the trialkali metal orthophosphate salts. The use of a mixture of the monosodium and disodium hydrogen orthophosphates in the ratio of 1:3 to 2:3,especially about 1:2, is particularly advantageous, as 2o such a mixture is made as a feedstock for the production of sodium tripolyphosphate and is therefore readily available.

Both the alkali metal orthophosphate and the sodium tripolyphosphate can be used initially as the anhydrous or hydrated salts, for example as trisodium orthophosphate dodecahydrate and penta25 sodium tripolyphosphate hexahydrate, but hydration normally takes place during detergent powder production. The amounts of the salts are, however, calculated in anhydrous form. The alkali metal tripolyphosphate used is potassium or preferably ossa sodium tripolyphosphate, the former being more expensive.

There have in the past been many suggestions for using mixed phosphate detergency builders, for example mixtures of sodium pyrophosphate and sodium tripolyphosphate, so as to give improved detergency building properties, or other benefits rather than to decrease the phosphorus content. Moreover, it is well known that the condensed phosphates such as sodium tripolyphosphate tend to degrade to form other phosphates under aqueous alkaline conditions at high temperatures, which are commonly met during detergent processing. Sodium tripolyphosphate degrades to give a mixture of mainly sodium pyrophosphate with a small amount of sodium orthophosphate, so that spray dried detergent products contain amounts of all three of these materials.

However, to the Applicants' knowledge, it has not been proposed hitherto to use the specific mixtures of alkali metal tripolyphosphate and alkali metal orthophosphate in the proportions set out in the powdered alkaline fabric washing detergent compositions according to the present invention. When mixtures of these materials have been proposed for use before, it has been at unsuitable levels or in other types of compositions often containing ingredients which are unsuitable for use in fabric washing compositions. For example, the pH of powdered dishwashing compositions is generally too high for fabric washing purposes, and products which contact the skin, for example detergent tablets, are generally about pH 7-8 which is too low for optimum detergency with the new mixed phosphate builder systems 43333 Whilst the ratio of the alkali metal tripolyphosphate to the alkali metal orthophosphate can be varied from 10:1 to 1:5 parts by weight, it is preferred to have a ratio of from 8:1 to 1:2, especially with an excess of the alkali metal tripolyphosphate over the alkali metal orthophosphate, within the ratio of from 5:1 to 1:1 parts by weight, for example from 4:1 to 3:2, and more especially from 3:1 to 2:1 parts by weight, respectively. These ratios of alkali metal tripolyphosphate to alkali metal orthophosphate are especially suitable for detergent compositions used at relatively high product concentrations, i.e. 0.3% to 0.3% by weight, as is common practice in Europe, especially in front-loading automatic washing machines, and where relatively high levels of phosphates are allowed in the products, i.e. equivalent to 4% to 7% P.

However, for detergent compositions which are to be used at relatively low product concentrations, i.e. from 0.1% to 0.3%, as is common practice under North American washing conditions, especially in top-loading automatic washing machines, and where relatively low phosphate levels are 2q permitted in the products, i.e. equivalent to less than 4% P, it may be desirable to increase the proportion of the alkali metal orthophosphate in the products. The ratio of alkali metal tripolyphosphate to alkali metal orthophosphate can then be from 2:1 to 1:5 parts by weight, preferably from 1:1 to 1:5, for example from 1:1 to 1:2 or 1:3 parts by weight, respectively. Alternatively, when especially low phosphate - 7 &3 3 3Z levels are enforced it may be beneficial to have a supplementary non-phosphate builder, whilst still achieving optimum detergency building from the phosphate builders in the compositions according to the invention.

It will be appreciated that the actual amounts of alkali metal tripolyphosphate and alkali metal orthophosphate are chosen according to the overall phosphate detergency builder level which is desired in the detergent compositions or according to the maximum permitted phosphorus content. Within the requirements of a total alkali metal tripolyphosphate and alkali metal orthophosphate level of 10% to 30% by weight of the product, it is preferable to have an alkali metal tripolyphosphate content of from 10% to 20%, and an alkali metal orthophosphate content of from 3% to 15%, especially 5% to 10% by weight of the product.

The total amount of alkali metal tripolyphosphate and alkali metal orthophosphate is preferably at least 15%, up to 25% by weight of the composition.

It may be observed that as the mixed alkali metal tripolyphosphate and alkali metal orthophosphate detergency builders are equivalent in detergency building properties, i.e. calcium binding capacity, to larger amounts of sodium tripolyphosphate used alone, this gives the choice of making detergent compositions of either increased detergency building properties by using the same total phosphate level, or with similar detergency building properties at a lower total phosphate level. The latter choice leaves some extra room in the compositions which can either by taken up hy cheaper fillers or hy other beneficial ingredients, for example extra amounts of bleaching agents such as sodium perborate or percarbonate, fabric softening agents, or amounts of other detergency boosting materials.

This new freedom to detergent manufacturers is of considerable commercial benefit. Thus, when some cheap filler, for example sodium sulphate, is used with a lower total phosphate level than used previously with sodium tripolyphosphate as the sole builder, the result is a substantial cost saving which can be passed on to the consumer. The same lower phosphate level can also be used to meet governmental or other restrictions as described previously, and if a cheap filler is not then used the overall performance of the compositions may if desired be boosted by some extra beneficial ingredients. Alternatively, the same total phosphate level may be retained as the original tripolyphosphate level alone, but in this case the overall detergency building capacity is boosted. The cost saving aspect of the compositions of the invention is of particular commercial benefit, especially when it can he achieved whilst still meeting lower phosphate restrictions, and it is remarkable that this has not been appreciated hitherto.

It is preferable that the only phosphate detergency builders used to make the compositions of the invention should be the sodium tripolyphosphate and sodium orthophosphate In particular, it is desirable to add no alkali metal, ie sodium or potassium, pyrophosphates to the compositions as they - 9 43332 tend to increase inorganic deposition. Moreover, the presence of significant levels of the alkali metal pyrophosphates instead of the sodium tripolyphosphate or sodium orthophosphate leads to lower detergency building capacities within the limited phosphate levels permitted. However, as mentioned earlier, some sodium pyrophosphate is produced with a lesser amount of sodium orthophosphate hy hydrolysis of sodium tripolyphosphate under the hot alkaline conditions met during spray drying, so low levels, ie up to 5%, of sodium pyrophosphate are unavoidable in spray dried powders. Preferably the total amount of phosphate materials present in the detergent compositions is not more than 30% by weight of the compositions. It should be noted that the amounts of the hydratable phosphate salts in the compositions are to he determined on an anhydrous hasis.

The detergent compositions of the invention necessarily include from 5% to 30%, preferably 1O% to 25%, by weight of a synthetic anionic, nonionic, amphoteric or zwitterionic detergent compound or mixture thereof. Many suitable detergent compounds are commercially available and are fully described in the literature, for example in ’'Surface Active Agents and Detergents, Volumes I and II, hy Schwartz, Perry and Berch.

The preferred detergent· compounds which can he used are synthetic anionic and nonionic compounds. The former are usually water soluble alkali metal salts of organic sulphates and sulphonates having alkyl radicals containing from 8 to 22 carbon atoms, the term alkyl being used to include the alkyl portion of higher acyl radicals. Examples of /..· 43533 suitable synthetic anionic detergent compounds are sodium and potassium alkyl sulphates, especially those ohtained hy sulphating higher alcohols produced for example from tallow or coconut oil; sodium and potassium alkyl C2q) benzene sulphonates, particularly sodium linear secondary alkyl (C^q-C^q) benzene sulphonates; sodium alkyl glyceryl ether sulphates, especially those ethers of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived from petroleum; sodium coconut oil fatty acid mono10 glyceride sulphates and sulphonates; sodium and potassium salts of sulphuric acid esters of higher (Οθ-Ο^) fatty alcoholalkylene oxide, particularly ethylene oxide, reaction products; the reaction products of fatty acids such as coconut fatty acids esterified with isethionic acid and neutralised with sodium hydroxide; sodium and potassium salts of fatty acid amides of methyl taurine; alkane monosulphonates such as those derived by reacting alpha-olefins with sodium bisulphite and those derived by reacting paraffins with SOg and Clg and then hydrolysing with a base to produce a random sulphonate; and olefin sulphonates, which term is used to describe the material made hy reacting olefins, particularly Cl0_C20 alpha-°leiins> with S03 and then neutralising and hydrolysing the reaction product. The preferred anionic detergent compounds are sodium alkyl benzene sulphonates and sodium alkyl sulphates.

Examples ol’ suitable nonionic detergent compounds which may he used include in particular the reaction products of alkylene oxides, usually ethylene oxide, with alkyl (Cg-CgO) phenols, /..· generally 5 to 25 EO, ie 5 to 25 units of ethylene oxide per molecule; the condensation products of aliphatic (Οθ-C^g) primary or secondary linear or branched alcohols with ethylene oxide, generally 6 to 30 EO, and products made by condensation of ethylene oxide with the reaction products of propylene oxide and ethylenediamine. Other so-called nonionic detergent compounds include long chain tertiary amine oxides, long chain tertiary phosphine oxides and dialkyl sulphoxides.

Mixtures of detergent compounds, for example mixed anionic or mixed anionic and nonionic compounds may be used in the detergent compositions, particularly in the latter case to provide controlled low sudsing properties. This is beneficial for compositions intended for use in suds-intolerant automatic washing machines. We have also found that the use of some nonionic detergent compounds in the compositions tends to decrease the tendency of insoluble phosphate salts to deposit on the washed fabrics .

Amounts of amphoteric or zwitterionic detergent compounds can also be used in the compositions of the invention but this is not normally desired due to their relatively high cost.

If any amphoteric or zwitterionic detergent compounds are used it is generally in small amounts in compositions based on the much more commonly used synthetic anionic and/or nonionic detergent compounds. For example, mixtures of amine oxides and ethoxylated nonionic detergent compounds can be used.

Some soaps may also be used in the compositions of the invention, but not as the sole detergent compounds.. They are particularly useful at low levels in binary and ternary mixtures together with nonionic or mixed synthetic anionic and nonionic detergent compounds, which have low sudsing properties. The soaps which are used are the sodium, or less desirably potassium, salts of fatty acids. It is particularly preferred that the soaps should be based mainly on the longer-chain fatty acids within this range, that is with at least half of the soap having a carbon chain length of 16 or over. This is most conveniently accomplished hy using soaps from natural sources such as tallow, palm oil or rapeseed oil, which can be hardened if desired, with lesser amounts of other shorter-chain soaps, prepared from nut oils such as coconut oil or palm kernel oil. The amount of such soaps can he varied between 0.5% and-25% by weight, with lower amounts of 0.5% to 5% being generally sufficient for lather control. Amounts of soap between j_g 26 and 20%, especially between 5% and 15%, are preferably used to give a beneficial effect on detergency.

Apart from the detergent compounds and detergency builders, the detergent compositions of the invention can contain any of the conventional additives in the amounts in which such materials are normally employed in fabric washing detergent compositions. Examples of these additives include lather boosters such as alkanolamides, particularly the monoethanolamides derived from palm kernel fatty acids and coconut fatty acids, lather depressants such as alkyl phosphates and silicones, anti25 redeposition agents such as sodium carboxymethylcellulose and polyvinyl pyrrolidone, oxygen-releasing bleaching agents such as sodium perborate and sodium percarbonate, per-acid bleach precursors, chlorine-releasing bleaching agents such as /... 43S32 trichloroisocyanuric acid and alkali metal salts of dichloroisocyanuric acid, fabric softening agents, inorganic salts such as sodium sulphate, sodium cax-bonate and magnesium silicate, and, usually present in very minor amounts, fluorescent agents, perfumes, enzymes such as proteases and amylases, germicides and colourants .

It is particularly beneficial to include in the detergent compositions an amount of sodium perborate, preferably between 10% and 40%, for example 15% to 30%, by .0 weight. It has been found that the bleaching action of sodium perborate is boosted under the higher alkaline conditions which also give optimum detergency building action for the alkali metal orthophosphate. Thus, it becomes possible to achieve improved bleaching properties hy using the same levels of sodium .5 perborate as normal; or decreased levels of sodium perborate can he used to give equal bleaching properties to those of conventional products with higher levels of perborate hut with sodium tripolyphosphate as the sole detergency builder. The latter option can also he used to further decrease the raw materials costs of the composition if a cheap filler is used in place of part of the sodium perborate.

It is desirable to include one or more antideposition agents in the detergent compositions of the invention, to decrease any tendency to form inorganic deposits on washed [5 fabrics. The amount of any such antideposition agent is normally from 0.1%.to 5% by weight, preferably from 0.2% to' 2% by weight of the composition. The preferred antideposition agents are homo- and co-polymers of acrylic acid or substituted acrylic acids, such as sodium polyacrylate, the sodium salt of copolymethacrylhmide/acrylic acid and sodium poly-alpha-hydroxyacrylate, salts of copolymers of maleic anhydride with ethylene, vinylmethylether or styrene, especially l!l copolymers, and optionally with partial esterification of the carboxyl groups especially in the case of the styrene-maleic anhydride copolymers. Such copolymers preferably have relatively low molecular weights, eg in the range of 5,000 to 50,000. Other antideposition agents include the sodium salts of polymaleic acid and polyitaconic acid, phosphate esters of ethoxylated aliphatic alcohols, polyethylene glycol phosphate esters, and certain phosphonates such as sodium ethane-l-hydroxy-l,l-diphosphonate, sodium ethylene diamine tetramethylene phosphonate, and sodium 215 phosphonobutane tricarboxylate. Mixtures of organic phosphonic acids or substituted acrylic acids or their salts with protective colloids such as gelatin may also be used. The most preferred antideposition agent is sodium polyacrylate having a MW of 10,000 to 50,000, for example about 27,000.

It is also possible to include in the detergent compositions of the invention minor amounts, preferably not more than 20¾ by weight, of other non-phosphate detergency builders, which may be either so-called precipitant builders or sequestrant builders. This is of particulai- benefit where it is desired to increase detergency whilst using particularly low levels of the essential alkali metal tripolyphosphate and alkali metal orthophosphate builders, so as to achieve low phosphorus - 15 - /... 43S33 contents in the detergent compositions. Examples of such other detergency builders are amine carhoxylates such as sodium nitrilotriacetate, sodium aluminosilicate ion-exchange materials, sodium citrate and soap, which can function as a detergency builder as discussed above. However, such other builder materials are not essential and it is a particular benefit of the compositions of the invention that satisfactory detergency building properties can he achieved with only phosphate builders at lower levels than hitherto considered necessary.

It is also desirable to include in the compositions an amount of an alkali metal silicate, particularly sodium ortho-, meta- or preferahly neutral or alkaline silicate. The presence of such alkali metal silicates at levels of at least 1¾ and preferahly from 5% to 15% by weight of the i compositions, is advantageous in decreasing the corrosion of metal parts in washing machines, besides giving processing benefits and generally improved powder properties. The more highly alkaline ortho- and meta-silicates would normally only he used at lower amounts within this range, in admixture with I the neutral or alkaline silicates.

The compositions of the invention are required to he alkaline, hut not too strongly alkaline as this could result in fabric damage and also he. hazardous for domestic usage.

In practice the compositions should give a pH of from 9 to 11 in use in aqueous wash solution. It is preferred in particular for domestic products to have a minimum pH of at least 9.25 and especially a pH of 9.5 or over, as lower pHs tend to he less effective for optimum detergency building, and a maximum - 16 4 3 S 32 pH of 10.5, as more highly alkaline products can he hazardous if misused. We require the pH to be measured at the lowest normal usage concentration of 0.1% w/v of the product in water of 12°H (Ca), (French permanent hardness, calcium only) at 50°C so that a satisfactory degree of alkalinity can he assured in use at all normal product concentrations. The pH is controlled hy the amount of alkali metal orthophosphate and any other alkaline salts such as alkali metal silicate, sodium perborate and alkali metal carbonate, the amount of the latter preferahly heing not «lore than 20% hy weight of the composition. The presence of other alkaline salts, especially the alkali metal silicates, is particularly beneficial because the alkalinity of the alkali metal orthophosphates is diminished in hard water due to precipitation of the calcium salt. The other ingredients in the alkaline detergent compositions of the invention should of course be chosen for alkaline stability, especially for pH-sensitive materials such as enzymes.

The detergent compositions of the invention should he in free-flowing powdered form and can he produced hy any of the techniques commonly employed in the manufacture of such fabric washing compositions, but preferahly hy slurry making and spray drying processes. It is advantageous in the slurry making step to he able to form the .alkali metal orthophosphate by neutralisation of orthophosphoric acid or by using so-called kiln-feed which is a crude mixture of mono- and di-sodium orthophosphates used in the preparation of sodium tripolyphosphate. It has also heen found that with the mixed alkali metal tripolyphosphate and alkali metal orthophosphate builders it /·.. 3532 is possible to use lower water levels than usual in the slurries for spray drying purposes, which is of economic benefit·. In particular, slurry water contents of about 50$ tend to he required for the conventional sodium tripolyphosphate powders, whereas the slurry water content can he down to about 40$ or even lower for making the mixed sodium tripolyphosphate and sodium orthophosphate-based products of the invention.

The invention is illustrated hy the following Examples in which parts and percentages are hy weight, and amounts of ingredients are expressed on an anhydrous basis, except where otherwise indicated.

Example 1 A spray dried powdered low sudsing detergent composition was prepared to the following nominal formulation: Ingredient Sodium (C,,-C,_) alkyl benzene 7.0 sulphoniie 15 Tallow amide - li EO condensate 1.5 Sodium hardened tallow soap 3.0 Sodium tripolyphosphate 16.0 Sodium orthophosphate 6.0 Sodium alkaline silicate 10.0 Sodium sulphate 23.4 Sodium perborate 25.0 Sodium carboxymethylcellulose 1.5 Fluorescent agents and preservatives 0.5 Water 6.1 /... 43S32 This composition was made by normal slurry making in a turbo-mixer, using a slurry temperature of 80°C and a final slurry moisture content of 3θ?έ (which is significantly lower than the usual moisture level of about 50# for sodium tripolyphosphate-based products), followed hy counter-current spray drying using an air inlet temperature of 300°C and an outlet teraperature of 100°C. The level of phosphate breakdown by hydrolysis during processing under these conditions was about 20#, giving in the final product about 12.7# sodium tripolyphosphate, 6.9# sodium orthophosphate and 2,4# sodium pyrophosphate. The composition had good powder properties and was stable during storage in laminated cartons at temperatures up to 37°C.

This product, which had a phosphorus content of about 5#, was compared for detergency against a commercially available heavy duty detergent composition (A) of similar nominal formulation, except that it contained about 35# of sodium tripolyphosphate (equivalent to about 9# phosphorus) instead of the mixed sodium tripolyphosphate and alkali metal orthophosphate in the product of the invention, and consequently it had a decreased level of 9# sodium sulphate. The detergency tests were undertaken using a product concentration of 0,6# in 40°H water, using- a Lavamat Begina automatic washing machine on the 95°C cycle. Domestically soiled articles were washed in 7 lb loads which included halved articles of varying types including towels, tea-towels and pillowcases.

The results showed a marginal preference for the appearance of the articles washed using the composition of the /.·. invention compared with the commercially available higher phosphorus product. Similar results were achieved when the tests were repeated using product concentrations of 0.4# and 0.8# in very hard water (40°H), and when the product concentration used was 0.6# in less hard water (25°H), in simulation of different practical washing conditions in continental Europe. Further actual domestic washing tests showed similar results for both products under these conditions and also at low wash temperatures (30°-40°C) for washing mainly synthetic fabrics. Replacement of the 7.0# sodium alkyl benzene sulphonate and i.5# tallow amide - 11 EO condensate hy 8,5# of sec-linear (C^-C^g) alcohol - 9 EO condensate (obtained as Tergitol 15-S-9) was found to improve the detergency results for the composition of the invention.

Further tests were also carried out to determine the levels of inorganic deposition on cotton terry towelling fabric at product concentrations of 0.4# and 0.8# in 40°H water (Ca:Mg, 4:l), under the same high temperature washing conditions.

After 10 repeated wash cycles the levels of the inorganic deposits were as follows: # deposits Product Concentration 0.4# Example 1 1.3 Product A 2.0 0.8# 2.6 0.2 These results show that the composition according to the invention is better at the lower product concentration, hut gives more inorganic deposition at the higher product concentration under these harsh conditions. Other tests showed generally similar properties for the two products as regards soil redeposition during washing and stain removal, but with noticeably improved bleaching properties for the product of the invention. It should be noted that the general similarity in results between the product of the invention and comparative composition (A) was achieved despite the much lower total phosphate level in the former and a consequently decreased materials cost.

Further tests were undertaken with a composition similar to Example 1 to which 1% of et,harie-l-hydroxy-l,l~diphosphonate and 1% of sodium polyacrylate (MW 27,000, obtained as Versieol E7) were separately added as antideposition agents.

Both of these additives were found to lower the levels of inorganic deposition on washed cotton terry towelling to 1.1% and 1.2%, respectively under the same washing conditions described above (at O.Sji product concentration in 40°H water). Decreased inorganic deposits were also found by using 0,5% of 1:1 copolymers of ethylene and maleic anhydride and of ethylene and vinylmethylether, particularly when using higher levels of nonionic detergent compounds in the products.

A further comparative test was undertaken with a product having the same amounts of sodium tripolyphosphate and orthophosphate as in Example 1 but with a decreased level of 6% alkyl benzene sulphonate and 2% of nonionic detergent compound, and with only 18% oi the sodium perborate (with consequent adjustment of the sodium sulphate level). This product was tested against a comparative conventional product having the same detergent compounds and 35?ό sodium tripolyphosphate and with 24$ of sodium perborate.

The results of the comparative domestic washing machine tests showed similar washing performance under the test conditions using water of 35° and 15° German hardness, at 45°C and 95°C. It was found in particular that the bleaching effect of both powders was similar, despite the much lower perborate content of the product according to the invention. In a further test, when the amount of the sodium perborate in a comparative product was decreased to 18$, the bleaching effect of the product according to the invention was significantly better than for the comparative sodium tripolyphosphate-based product.

A further comparative test was undertaken using the formulation of Example 1 to which 0.62$ of proteolytic enzyme Alcalase*particles (activity 1 Anson unit) was added.

Washing machine evaluation tests showed generally equivalent performance to a commercially available product containing 35$ of sodium tripolyphosphate with the same enzyme level.

Example 2 A powdered high sudsing detergent composition was prepared to the following nominal formulation: 43332 Ingredient .0 Sodium tripoiyphosphafce Sodium orthophosphate 16.0 .0 Sodium alkaline silicate .0 Sodium carbonate .0 Sodium sulphate .5 14.0 Sodium carboxymethylcellulose Fluorescent agents, moisture 1.0 to 100.0 The ahove detergent composition was evaluated against a standard detergent product (B) having a similar formulation except that the 5% of sodium orthophosphate was replaced hy 16% of sodium tripolyphosphate to give a conventional level of 32% of the latter material, whilst the amounts of borax and sodium carbonate were also correspondingly decreased to 5% each and the level of sodium sulphate increased from 15.5% to 18.5% in the comparative product (B). In laboratory detergency tests using soiled cotton vests the light reflectances of the washed . garments using the composition of Example 2 and comparative product (B), respectively, were found to he 75% and 80% of the light reflectances of the original clean garments, which is not a significant difference. In the same test the fluorescent agent deposition onto the washed garments was also measured and found to he marginally better for the product according to the invention. The products were also compared in domestic washing tests, when It was found overall that both products were acceptable to the users with no signifieatit preference for either product. This general similarity in detergent properties was again achieved despite the much lower phosphate builder level, and consequent lower manufacturing cost, of the -43532 product of the invention.

Example 3 A powdered detergent composition was prepared to the following nominal formulation: Ingredi ent Sodium alkyl benzene sulphonate 4.0 Tallow alcohol - 18 EO condensate 4.0 Sodium tripolyphosphate 17.0 Sodium orthophosphate 8.0 Sodium silicate 10.0 Sodium tallow soap 5.0 Sodium hardened tallow soap 3.0 Sodium perborate 25.0 Sodium sulphate, water to 100.0 This formulation was evaluated in washing machine tests with cotton halved articles and found to he equal in overall detergent performance to commercially available product containing the same detergent compounds and the sodium hardened tallow soap but with a much higher level of 35?o sodium tripolyphosphate as the sole phosphate builder.

Examples 4 and 5 Two powdered detergent compositions were prepared to the following nominal formulations: /...

Inaredient Example 4 Example ί Sodium alkyl benzene sulphonate 13.00 13.00 Sodium tripolyphosphate 23.65 9.50 Sodium orthophosphate 2.50 6.70 Sodium sulphate 23.60 33.55 Tallow ethanolamide 1.00 1.00 Sodium toluene sulphonate 0.50 0.50 Sodium carboxymethylcellulose 0.50 0.50 Sodium perborate 19.00 19.00 Fluorescent agents, perfume, to 100.00 to 100.00 moisture These powders were each produced hy spray drying, with the sodium perborate being added to the spray dried powders, using a slurry temperature of about 70°C, a slurry water content of about 42#, an air inlet temperature of about 330°C and an air outlet temperature of about 110°C.

The two mixed phosphate products according to the invention were evaluated in domestic washing tests against a commercially available product of similar formulation except that it contained 32# sodium tripolyphosphate as the only phosphate builder, with a consequent reduction in the sodium sulphate level. The overall result of the various attributes assessed by the testers gave no significant preference for any one of the products over the others despite the lower phosphate contents of the products according to the invention. Detailed analysis of the results showed slight inferiority in soft water detergency foi· the products of the invention, which could he improved hy the addition of about 5# of soap. /... 43332 Examples 6 to 11 In order to confirm the compatibility of various detergent compounds with the mixed phosphate builder system according to the invention, a series of detergent formulations were prepared and tested in Terg-O-Tometers. used were as follows: Ingredient Detergent compound Sodium tripolyphosphate ) Potassium orthophosphate Sodium alkaline silicate Sodium sulphate, water The amounts of the ingredients .0 .0 8.0 .0 to 100.0 The results using different detergent compounds were as follows (using a test procedure with 15 minute wash at 60°C at a product concentration of 0.6# in hard water (25° Ca, 5° Mg, French hardness)), which showed good compatibility for all the detergent compounds tested. /... 43S32 ¢0 ο ft fi © 01 co co μ © © 03 co co co co co ¢0 >, φ S3 Φ bi fl φ μ Φ Ό Φ ς-ι ο -μ ο ω φ -μ ω © r-i ο Ο] ο co fl 3 «····· ι—I Ο -ι ΤΗ Λ G0 ΟΙ ·Ο 5Φ 03 μ τΗ CM 03 Φ Φ •π fl -μ G Sh *Κ β Φ a Ο X fl μ & τ3 C β ο & S ο ο «μ β Φ Μ s? φ μ φ X Φ S μ μ fl fl Ό μ S Φ Φ 0 μ μ Φ •μ (Η μ a O μ fl i—t 02 μ X 2 fl a 03 X fl Φ μ μ 44» 3 Φ O fl β 03 Φ f μ fl fl μ fl Φ 0 φ o fl a X X fl £3 X o μ μ a μ a Sh 03 μ μ a Φ © ft a Φ £ 2 3 4-i β o •μ ω fl fl | 03 μ X μ fl fl Sh μ φ Ο μ rH O Φ ο β ι-Η X is is a μ μ φ iS a X 2 03 Φ ts) X μ ft ft fl Φ fl μ 2 fl fl iS μ φ Φ 03 μ μ 03 >4 X μ Ο Ω- £ 1? μ φ Ό 0 1 © φ ε fl Ο μ μ μ 03 μ μ· * μ fl fl Ο Ο Τ3 μ is μ 0 ε *1 ε μ ε μ Φ 2 ο 2 © 2 μ fl μ 1 μ fl «Ί Ό Ά Χ3 C3 Χ3 2 * 0 Ps Ο μ Ο fl ω W W © ω X μ -μ /...

Examples 12 and 13 Two detergent compositions were prepared to the following nominal formulations: Ingredient Example 12 Example 13 Sodium alkyl (C,.-0,^) benzene sulphonate0 8.0 8.0 Sodium tripolyphosphate 16.0 16.0 Sodium orthophosphate 6.0 6.0 3 Sodium tallow soap 10.0 - Sodium nitrilotriacetate - 10.0 Sodium alkaline silicate 10.0 10.0 Sodium sulphate, water to 100.0 to 100.0 These products were evaluated for detergency in a Terg-O-Tometer at a product concentration of 0.6% in soft wat er (5°H Oa) at 40°C. The results using artificially soiled test cloths showed both products to have good detergencies under these conditions, comparable with a conventional product of much higher phosphate level (35% sodium tripolyphosphate), and noticeably better than a similar product which did not contain . the added sodium tallow soap or sodium nitrilotriacetate.

Example 14 Two detergent compositions were prepared to the following nominal formulations: Ingredient A B Sodium alkyl benzene sulphonate 15.0 15.0 Sodium tripolyphosphate 15.0 10.0 Sodium orthophosphate 5.0 5.0 Sodium pyrophosphate - 5.0 Sodium sulphate, water to 100.0 to 100.0 Pieces of clean cotton terry towelling were washed in 0.6$ solutions of these products in 40°H Ca water at 60°C, and then dried, and then the procedure was repeated up to 20 complete wash cycles. The levels of inorganic deposits on the fabrics were determined after 10 and 20 wash cycles hy incinerating the cloths at 600°C and weighing the resultant ash. The results were as follows: $ ash washes washes Product A 0.49 0.81 Product B 0.90 1.28 These results show that the presence of 5$ pyrophosphate in replacement for 5(i of the sodium tripolyphosphate increased inorganic deposition on the fabric.

Example 15 A spray dried detergent composition was prepared to the following nominal formulation: /...

S 5 3 2 Ingredient Sodium alkyl (0χβ-0χ8) sulphate 8.0 Sodium tripolyphosphate 17.0 Sodium orthophosphate 8.0 Sodium hardened tallow soap 15.0 Sodium alkaline silicate 10.0 Sodium perborate 27.0 Sodium sulphate, water to 100.0 This composition was evaluated against a product with 31% ι of sodium tripolyphosphate and found to give superior detergency in washing machine tests at 0.6% product concentration at both 60°C and 90°C in 15°, 25° and 35° (French) hard water (Ca:Mg, 4:l).

Example 16 A dry mixed powdered high sudsing detergent composition was prepared to the following nominal formulation: Ingredient % Sodium linear sec-(C -C,g) benzene sulphonate1 alkyl 16.0 Sodium tripolyphosphate 8.0 Sodium orthophosphate 10.0 Sodium alkaline silicate 5.9 Sodium sulphate 39.0 Water to 100.0 This product which had a phosphorus content of 4% was evaluated against a comparative product of similar formulation except that the sodium orthophosphate was replaced hy an additional 25% of sodium tripolyphosphate, to give a conventional total level of 33(; of the latter detergency builder, ie a phosphorus level of about 9% in the comparative product, with a consequent decrease in the sodium sulphate level. Detergency * tests were undertaken in Whirlpool Supreme 80 automatic washing machines using a product concentration of 0.1% at 48°C in 8°H water (6° Ca, 2° Mg), when it was found that both products gave similar overall performance despite the much lower phosphate level for the product of the invention. When the tests were repeated at 0.2% there was an overall small preference for the comparative product with the much higher detergency builder content.

Further tests were undertaken in which the amounts of sodium tripolyphosphate and sodium orthophosphate were changed to 1% and 15%, respectively, ie still an overall phosphorus content of only 4%. Comparative detergency tests under the same conditions then showed a marginal, non-significant preference for the mixed builder product according to the invention at 0.1% product concentration, whereas at 0.2% product concentration the comparative product was preferred.

Examples 17 and 18 Two detergent compositions were prepared to the following nominal formulations: /...

Ingredient 22 Example 17 Example 18 Sodium alkyl (C,,-C,5) benzene sulphonate0 10.0 - Sec-linear (C -C._) alkyl 9 EO condensate1 - 10.0 Sodium tripolyphosphate 5.0 5.0 Sodium orthophosphate 15.0 15.0 Sodium alkaline silicate 10.0 10.0 Sodium sulphate, water to 100.0 to 100.0 These products were evaluated In a Terg-O-Tometei* detergency testing apparatus at a concentration of 0.15# in water of 6°H (French hardness 5° Ca, 1° Mg) and 12°H (French hardness 10° Ca, 2° Mg) at 40°C, against a comparative product of similar formulation to Example 17 except in having 35# of sodium tripolyphosphate as the sole phosphate builder. The results using an artificially soiled cotton polyester test cloth showed generally acceptable results for all three detergent products despite the much lower phosphate content of the products of the invention, hut with a small preference for the comparative product under the soft water conditions. Substantially similar detergency results are achieved for all three products in hard water.

Further tests were done using the same formulations as Examples 17 and 18 but with different detergent compounds, namely, hydroxyalkyl methyl taurine, sodium olefin sulphonate, sodium (C^g-C^^Jalkyl - 9 EO sulphate, sodium C|g-C18 alkyl sulphate and lauryl dimethyl ammoniopropane sulphonate. The /... 43332 results on washing artificially soiled test cloths under the same conditions as previously except using hard water (25°H Ca, and 5°H Mg, French hardness), showed all the detergent compounds to be compatible with the mixed phosphate builder system, with the better overall results being achieved using the sodium (C49-C44)alkyl - 9 EO sulphate.

Example 19 A spray dried detergent powder was prepared to the following nominal formulation: Ingredient k Sodium alkyl benzene sulphonate 16,0 Sodium tripolyphosphate 14.0 Sodium orthophosphate 14.5 Sodium alkaline silicate S.O 15 Sodium sulphate, water to 100.0 This formulation had good physical properties and good detergent properties at low dosage levels in comparison with a conventional sodium tripolyphosphate-built product with a higher total phosphate content.

* Registered Trade Marks.

Claims (28)

CLAIMS:

1. A powdered alkaline fabric washing detergent composition, comprising from 5% to 30% of a synthetic anionic, nonionic, amphoteric or zwitterionic detergent compound or a mixture thereof, and from 10% to 30% of mixed alkali metal tripolyphosphate and alkali metal orthophosphate in the ratio of from io?l to 1:5 parts by weight, wherein the amount of the alkali metal tripolyphosphate is at least 5% and the amount of any alkali metal pyrophosphate is not more than 5%, all these percentages being expressed by weight of the total detergent composition, and the pH of a 0.1% aqueous solution of the composition is from 9 to 11.

2. A detergent composition according to claim 1, wherein the alkali metal orthophosphate is trisodium orthophosphate and the alkali metal tripolyphosphate is sodium tripolyphosphate.

3. A detergent composition according to claim 1 or claim 2, wherein the ratio of the alkali metal tripolyphosphate to the alkali metal orthophosphate is from 5:1 to 1:1 parts by weight.

4. A detergent composition according to claim 3, wherein the ratio of the alkali metal tripolyphosphate to the alkali metal orthophosphate is from 4:1 to 3:2 parts by weight. ί 3 5 3 ,2

5. A detergent composition according to claim 4, wherein the ratio of the alkali metal tripolyphosphate to the alkali metal orthophosphate is from 3:1 to 2:1 parts by weight.

6. A detergent composition according to any of the preceding 5 claims, wherein the total amount of the alkali metal tripolyphosphate and the alkali metal orthophosphate is from 15% to 25% by weight of the composition.

7. A detergent composition according to any of the preceding claims, wherein the total amount of the phosphate salts is not 0 more than 30% by weight of the composition.

8. A detergent composition according to any of the preceding claims, wherein the amount of alkali metal tripolyphosphate is from 10% to 20% by weight of the composition.

9. A detergent composition according to any of the preceding ; claims, wherein the amount of the alkali metal orthophosphate is from 3% to 15% by weight of the composition.

10. A detergent composition according to any of the preceding claims comprising soap.

11. A detergent composition according to claim 10 , comprising from 0.5% to 25% by weight of soap of C 1O -C 24 fatty acids, at least half of which have carbon chain length of 16 or over. 4 3 5 3 2

12. A detergent composition according to claim 11 comprising from 2% to 20% by weight of the soap.

13. A detergent composition according to claim 12 comprising from 5% to 15% by weight of the soap.

14. A detergent composition according to any of the preceding claims comprising an antideposition agent.

15. A detergent composition according to claim 14, wherein the amount of the antideposition agent is from 0.1$ to 5$ by weight of the composition.

16. A detergent composition according to claim 14 or claim 15, wherein the antideposition agent is a salt of a homo- or copolymer of acrylic acid or a substituted acrylic acid, or a copolymer of maleic anhydride with ethylene, vinylmethylether or styrene.

17. A detergent composition according to any of claims 14 to 16, wherein the antideposition agent is sodium polyacrylate having a MW between 10,000 and 50,000.

18. A detergent composition according to any of the preceding claims comprising an alkali metal silicate. 4353 2 t

19. A detergent composition according to claim 18 comprising from 5% to 15% by weight of sodiuin neutral or alkaline silicate.

20. A detergent composition according to any of the preceding 5 claims, wherein the pH of a 0.1% aqueous solution of the composition is from 9 to 10.5.

21. A detergent composition according to claim 20, wherein the pH of the 0.1% aqueous solution of the composition is from 9.5 to 10.5. 3

22. A detergent composition according to any of the preceding claims, wherein the detergent compound comprises a nonionic detergent compound.

23. A detergent composition according to any of the preceding claims comprising from 10% to 25% by weight of the i detergent compound or mixture thereof.

24. A detergent composition according to any of the preceding claims comprising from 10% to 40% by weight of sodium perborate.

25. A detergent composition according to any of the preceding claims containing no added alkali metal pyrophosphate. 4 3 3 3 2

26. A detergent composition according to any of the preceding claims containing not more than 20% by weight of alkali metal carbonate.

27. A detergent composition according to any of the preceding claims containing an amount not more than 20% by weight of a sodium aluminosilicate ion-exchange material.

28. A detergent composition according to claim 1 substantially as described herein with reference to any of the foregoing Examples.