GB2208516A - Detergent composition - Google Patents

Abstract

A soil release promoting detergent composition of improved soil release promoting properties in cold water washing of polyester-containing fabrics that have been soiled with oily soils, which improved soil release is due to the presence therein of narrow range ethoxylate (NRE) nonionic detergent and soil release promoting polyethylene terephthalate- polyoxyethylene terephthalate (PET-POET) copolymer instead of broad range ethoxylate (BRE) nonionic detergent and PET-POET copolymer, comprises a detersive proportion of such a NRE type of a nonionic detergent, which is a polyethoxylated lipophile, ethoxylated with an average of 5 to 10 ethylene oxide groups per mole, and with at least 70% of the ethylene oxide being in polyethoxy groups of 4 to 12 ethylene oxides, and a soil release promoting proportion of PET- POET copolymer soil release promoting agent.

Description

DETERGENT COMPOSITION This invention relates to nonionic synthetic organic detergent compositions of improved soil release promoting properties. More particularly, it relates to such detergent compositions, in both particulate solid and liquid forms, which comprise soil release promoting polyethylene terephthalate-polyoxyethy lene terephthalate (PET-POET) copolymer as a soil release promoting agent, and narrow range ethoxylate (NRE) nonionic detergent, which functions as a detergent, but which also significantly improves the soil release promoting effect of the PET-POET copolymer.

The improved soil release promoting activity of compositions of the invention is most pronounced when laundry being washed (and being simultaneously treated with soil release promoting agent) is of a fabric or fabrics which include(s) synthetic organic polymeric fibrous material(s), especially polyester(s), and when washing is at low temperature, e.g. 10 to 300 or 15 to 250C.

Prior to the present invention it was known to make particulate built synthetic organic detergent compositions, utilizing nonionic detergents and phosphate and/or non-phosphate builders. The non-phosphate builders that have been employed include both water soluble and water insoluble builders. The solubles include alkali metal silicates, carbonates, bicarbonates, and borates, and the water insoluble builders include zeolites, all of which are well known in the art. Such compositions are described in a number of U.S. patents issued to the present applicants, Colgate Palmolive Company, and products of this type, wherein spray dried base beads of builder salt have nonionic detergent, in liquid state, absorbed into them, have been marketed by that company under the trademark FRESH START (Registered Trade Mark).

PET-POET polymers have been suggested as components of particulate detergent compositions, in which they help to promote the release of later applied soils from laundry. Patents describing such polymers and such function thereof include British Patent Specification 1,088,984 and U.S. Patent 3,962,152. U.S.

Patent 3,962,132 discloses polyacrylate in zeolitebuilt detergent compositions and U.S. Patent 4,283,299 discloses polyacrylate in phosphate-built nonionic detergent compositions for its antiredeposition function.

In the prior art it has also been disclosed that soil release promoting polymers like those utilized in the present invention (PET-POET) may be incorporated in liquid detergent compositions. It also has been known that nonionic detergents are useful detersive components of liquid detergent compositions. In some liquid detergents both PET-POET copolymer and broad range ethoxylate nonionic detergents (BRE) have been utilized.

U.S. Patent 4,441,881 discloses NRE nonionic detergent compositions containing builder and a small proportion of modified cellulose ether, such as hydroxypropylmethyl cellulose or methyl cellulose, as "soil shields". In this patent the nonionic detergent described is a higher fatty alcohol narrow range polyethoxylate (NRE) nonionic detergent which is taught to be less likely to smoke or fume off from the top of a spray tower when a crutcher mix containing such nonionic detergent is spray dried. U.S. patent 4,441,881 also mentions that the NRE thereof, in the compositions described in the patent, made such compositions superior in cleaning ability to similar compositions in which conventional, or broad range, ethoxylates (BRE' s) were employed as nonionic detergents.Please note that in the preceding sentence, and subsequently, to save repetition of "nonionic detergent", NRE and BRE refer to such deteregnts, not merely to types of ethoxy moieties thereof.

U.S. Patents 4,569,772 and 4,571,303 both describe detergent compositions similar to some of those of the present invention, with the exception that neither of such patents mentions NRE's and neither discloses nor suggests that employing NRE's instead of BRE's in such compositions would synergistically improve the soil release promoting characteristics of the PET-POET copolymer in such compositions.

Although the prior art includes various components of the present compositions it is considered that detergent compositions comprising a combination of NRE and PET-POET copolymer are novel and because of the unexpectedly beneficial effects obtained from them (improved soil release promotions) compared to other such compositions that are based on BRE's, unobviousness of the present invention has been established.

Although the art described above, which was found in searches for art relevant to the present invention, relates to various combinations of the required components of the invented compositions, it does not teach a person skilled in the art to employ NRE's instead of BRE's in built detergent compositions that contain PET-POET soil release promoting polymers, with or without polyacrylate stabilizer (in the built particulate compositions) and certainly such art would not teach or suggest that applicants' claimed compositions would be of improved soil release promoting actions due to the presence therein of NRE nonionic detergents instead of BRE nonionic detergents.

In accordance with the present invention a soil release promoting detergent composition of improved soil release promoting properties in cold water washing of polyester-containing fabrics that have been soiled with oily soils, which improved soil release is due to the presence therein of narrow range ethoxylate (NRE) nonionic detergent and soil release promoting polyethylene terephthalate-polyoxyethylene terephthalate (PET-POET) copolymer instead of broad range ethoxylate (BRE) nonionic detergent and PET-POET copolymer, comprises a detersive proportion of such a NRE type of a nonionic detergent, which is a polyethoxylated lipophile, ethoxylated with an average of 5 to 10 ethylene oxide groups per mole, and with at least 70% of the ethylene oxide being in polyethoxy groups of 4 to 12 ethylene oxides, and a soil release promoting proportion of PET-POET copolymer soil release promoting agent. Also within the invention is a method of washing laundry and imparting soil release promoting properties to it by repeated washing of such laundry with a composition of the invention.

The active detergent constituent of the present compositions and methods is primarily a nonionic detergent. Anionic synthetic organic detergents may tend to inactivate PET-POET copolymers or can inhibit soil release promotion by them, probably by interfering with the deposition of such copolymers from the wash water onto the laundry. However, anionic detergents may sometimes be employed in relatively small proportions in substantially nonionic detergent compositions without having detrimental effects on soil release promotion by the PET-POET copolymer.

Of the nonionic detergents it is preferred to employ those which are NRE reaction or condensation products of ethylene oxide and a suitable lipophile or lipophilic material. Higher alcohols, usually fatty alcohols of 12 to 18 carbon atoms per molecule, are preferred reactants with ethylene oxide to make the desired nonionic detergents for the compositions of this invention, but Oxo-type alcohols and middle phenols, such as nonyl phenols, may also be useful.

Other members of this well known class of nonionic detergents, such as higher fatty acid esters of ethylene oxide, may also be useful in some compositions and for particular applications. Preferably a higher fatty alcohol is employed as the source of the lipophile, and the ethylene oxide condensation product is a narrow range ethoxylate nonionic detergent (NRE). By narrow range ethoxylate is meant a polyethoxylated lipophile, ethoxylated with ethylene oxide so that at least 70% of the ethylene oxide in the nonionic detergent is in polyethoxy groups having n to (n+8) moles of ethylene oxide per mole, wherein n may be from 1 to 10, although it is preferable that n be 3 to 5, more preferably about 4. Thus, the narrow range ethoxylate (NRE) nonionic detergent preferably has at least 70% of the ethylene oxide thereof in polyethoxy groups of 4 to 12 ethylene oxides. Most preferably, such groups are of 5 to 10 ethoxies and are at least 80 or 85% of the ethoxy content of the NRE's. Instead of ethylene oxide, in some cases mixtures of ethylene oxide and propylene oxide may be employed in such NRE's, providing that the final product has the desirable and unexpectedly beneficial properties, in conjunction with the PET-POET copolymer to be described in more detail later in this specification, so that soil release promotion is improved, compared to compositions containing the same PET-POET copolymer but employing broad range ethoxylate (BRE) nonionic detergent, the normal nonionic detergents of the art, instead.

Although it may be preferred for the polyethoxylates of the NRE's to be within certain ranges of ethoxy contents in the polyethoxy moieties thereof, manufacturing methods usually result in mixtures of polymers, so average ethoxy contents may be specified. Thus, the NRE nonionic detergents may be of an average of 4 to 12 or 5 to 10 ethylene oxide groups per mole, e.g.

averaging about 6 or 7 EtO's per mole. The preferred lipophile will be that from higher fatty alcohol and therefore the ethylene oxide content of the NRE nonionic detergents will be at least 70% of higher fatty alcohol ethoxylates averaging or of 5 to 10 ethylene oxide groups per mole and more preferably, at least 80 or 85% of the ethylene oxide will be in such higher fatty alcohol ethoxylates. This compares with about 50% or less of such polyethoxy groups in BRE's.

Also, the higher fatty alcohol of the higher fatty alcohol ethoxylates will preferably be of 12 to 14 carbon atoms, although sometimes the fatty alcohol may be of 10 to 16 or 12 to 16 carbon atoms. It is within the invention to employ synthetic lipophiles, such as those derivable from higher fatty alcohols of odd numbers of carbon atoms in the ranges given, or those derivable from higher fatty alcohols of even numbers of carbon atoms, as in natural products, and mixtures thereof may also be utilized.

NRE's that are presently available are preferably manufactured by catalyzed condensation reactions which promote the production of a narrow range of polyethoxylates in the alkoxylated lipophile detergent.

Products produced catalytically are characterised by a normal distribution curve when ethylene oxide content (abscissa) is plotted against weight percent (ordinate) but the peak of the bell-shaped curve is much higher for the NRE than for the BRE nonionic detergents.

Similar products, of similar distribution curves may be made by "topping" and "bottoming" BRE's or other NRE's, such as by removing higher and lower polyethoxylates by solvent extractions, distillations and other suitable physical processes. The BRE nonionic detergents will include lower percentages of a narrow range of desired polyethoxylates, such as those of 4 to 12 or 5 to 10 EtO's, often less than 50%, compared to more than 708 for the NRE's. They will also include at least about 1% of all unit degrees of ethoxylation from 1 to 16 or 1 to 20, even when it is desired to have the average or mean ethylene oxide content at 7 moles per mole, for example.However, an NRE which averages 7 moles of EtO per mole will usually have no higher polymer of ethylene oxide than 15, and the proportions of polyoxyethylene in the 4 to 12 and 5 to 10 EtO ranges will be significantly increased. Such increase and the narrower distribution range of the polyethoxy moieties apparently changes the properties of the NRE for the better when it is included in a detergent composition with PET-POET copolymer. The reason for this effect is not fully understood at present but it may be related to a lesser interference of the nonionic detergent with the laying down of the PET-POET copolymer on the laundry substrate, prior to soiling and ultimate removal by subsequent washing.Within the "peak" area of an NRE curve, as from 5 to 10 ethoxy groups per polyoxyethylene moiety, the percentages of the 5 to 10 EtO moieties for the NRE's, compared to BRE's, may range from 15% more to 60% more, with the peak differences being for the 7 and 8 EtO polyethoxylates.

Among the preferred NRE nonionic detergents employable in accordance with the present invention is Tergitol (Registered Trade Mark) Nonionic Surfactant 24-L-60N, which is of the formula RO(CH2CH2O)nH, wherein R is a mixture of C12 and C14 linear alcohols and n averages about 7.0. Such product has a cloud ponit of 600C for a 1% aqueous solution and is a narrow range ethoxylate. Its properties are described in a product information bulletin issued by the manufacturer, Union Carbide Corporation, which carries the date of April, 1987. Other Tergitol Nonionic Surfactants which may also be employed, at least in part, with the 24-L-60N, include 26-L-60N, 24-L-45N and 24-L-75N, wherein the 60, 45 and 75 indicate cloud points, in degrees Centigrade.Also, it is considered that similar products, manufactured by Shell Chemical Company, which have been identified as Shell 23-7P and Shell-23-7Z, may be substituted, although the results may not be as satisfactory.

Ethoxylate distributions of the various NRE1s are reported in Tergitol Surfactants Technical Service Bulletins entitled Ethoxylate Distribution of Tergitol 24-L Nonionic Surfactantsby Gas Chromatography, issued by the Ethylene Oxide Derivatives Division of Union Carbide Corporation. The following table, Table 1, summarizes the ethoxylate distribution (by gas chromatography) of two of the preferred NRE's mentioned above, and of comparable BRE's.

TABLE 1 Weight Percent of RO(C112CH2O)nH Tergitol Tergitol Tergitol Tergitol 24-L-60N 24-L-60 24-L-75N 24-L-75 n 0 0.6 1.3 0.3 0.9 1 0.2 0.9 0.0 0.6 2 0.4 1.8 0.2 1.2 3 1.1 3.1 0.4 2.0 4 2.7 5.4 1.2 3.6 5 6.6 7.0 3.1 5.3 6 13.1 9.0 7.6 6.8 7 19.5 10.3 14.3 8.6 8 21.5 11.1 20.3 10.6 9 16.3 11.2 20.6 10.9 10 9.5 10.0 15.5 10.5 11 4.1 8.0 8.8 9.4 12 1.3 6.3 3.9 7.6 13 0.4 4.3 0.9 5.5 14 1.8 2.2 Total: 97.3 91.5 97.1 85.6 *100% recovery of the sample is not achieved due to holdup of higher ethoxylates in the GC column.

PET-POET copolymers useful in this invention will usually be of molecular weights in the range of 19,000 to 43,000, more preferably being about 19,000 to 25,000, e.g. about 22,000, according to molecular weight determinations performed on samples thereof that are usually employed herein. Such molecular weights are weight average molecular weights, as distinguished from number average molecular weights, such, in the case of the present polymers, are often lower. In the polymers usable the polyoxyethylene will usually be of a molecular weight in the range of about 1,000 to 10,000, preferably about 2,500 to 5,000, more preferably 3,000 to 4,000, e.g. 3,400. In such polymers the molar ratio of polyethylene terephthalate to polyoxyethylene terephthalate units (considering

as such units) will be within the range of 2:1 to 6:1, preferably 5:2 to 5:1, more preferably 3:1 to 4:1, e.g.

about 3:1. The proportion of ethylene oxide to phthalic moiety in the polymer will normally be at least 10:1 and often will be 20:1 or more, preferably being within the range of 20;1 to 30:1, and more preferably being about 22:1. Thus, it is seen that the polymer may be considered as being essentially a modi fied ethylene oxide polymer with the phthalic moiety being only a minor component thereof, whether calculated on a molar or weight basis. It was considered surprising that with such a small proportion of ethylene terephthalate or polyethylene terephthalate in the copolymer, such copolymer is sufficiently similar to the polymer of the polyester fibre substrate (or other polymers to which it is adherent, such as polyamides) as to be retained thereon during washing, rinsing and drying operations.

Although the above described PET-POET copolymer is that which is employed normally by the applicant, in accordance with the present invention, and that which is highly preferred for its desired functions, other PET-POET polymers, such as some of those described in U.S. Patent 3,962,152 and British Specification 1,088,984, may also be employed and it is considered that they can sometimes be effective soil release promoting agents in the compositions of this invention.

However, it is believed that the soil release promoting properties of such materials are usually inferior to those of the preferred polymers.

The PET-POET copolymers useful in the practice of the present invention are available from Alkaril Chemicals, Inc. in powder or aqueous dispersion form, as Alkaril (Registered Trade Mark) QCF (powder) and Alkaril QCJ (aqueous liquid). Of course, for the manufacture of liquid detergent compositions use of the QCJ product is preferred. Other copolymers, which also contain polyacrylate stabilizer (usually in 4:1 copolymer:polyacrylate weight ratio), are supplied by such company under the names Alkaril Base C and Alkaril Velvetol 251-C.

Various builders and combinations thereof which are effective to complement the washing action of the nonionic synthetic organic detergent(s) and to improve such action, especially in particulate detergent compositions, include both water soluble and water insoluble builders. Of the water soluble builders, both inorganic and organic builders may be useful, but the inorganics are preferred, usually as alkali metal salt(s). Among the water soluble inorganic builders those of preference include: various phosphates, usually polyphosphates, such as the tripolyphosphates and pyrophosphates, more specifically the sodium tripolyphosphates and sodium pyrophosphates, e.g. pentasodium tripolyphosphate, tetrasodium pyrophosphate; sodium carbonate; sodium bicarbonate; sodium silicate; sodium borate or borax; and mixtures thereof.Instead of a mixture of sodium carbonate and sodium bicarbonate, sodium sesquicarbonate will sometimes be substituted. The alkali metal or sodium silicate, when employed is normally of M2O:SiO2 or Na2O:SiO2 ratio within the range of 1:1.6 to 1:3, preferably 1:2.0 to 1:2.8, e.g. 1:2.4 (or 1:2.35).

Of the water soluble inorganic builder salts, when phosphates are not objectionable they may be employed, sometimes with a lesser proportion of sodium silicate.

In preferred non-phosphate compositions carbonates may be employed with bicarbonates and sometimes with borates and/or lesser proportions of sodium silicates.

Silicates will rarely be used alone. Instead of individual polyphosphates being utilized it may sometimes be preferred to employ mixtures of sodium tripolyphosphate and sodium pyrophosphate in proportions within the range of 1:10 to 10:1, preferably 1:5 to 5:1. Of course, it is recognized that changes in phosphate chemical structure may occur during crutching and spray drying so that the final product may differ in phosphate content somewhat from the phosphate components charged to the crutcher, which are those set forth in the present description. Although sometimes water soluble organic builders may be employed too, such as trisodium nitrilotriacetate (NTA), water soluble inorganic builders are generally preferred, as was previously indicated.The various water soluble builder salts may be utilized in hydrated forms, which are sometimes preferred, and the water soluble builders, hydrated or anhydrous, will normally be sodium salts, or mixtures of alkali metal salts, but sodium salts are usually preferred. In some instances, as when neutral or slightly acidic detergent compositions are being produced, acid forms of the builders may be preferable but normally the salts will either be neutral or basic in nature, and usually a 1% aqueous solution of the detergent composition will be of a pH in the range of 9 to 11.5, e.g. 9 to 10.5.

Insoluble builders, generally of the Zeolite A type, usually hydrated, as with 15 to 25% of water of hydration, may be used advantageously in the compositions of the present invention. Hydrated Zeolites X and Y may be useful too, as may be naturally occurring zeolites and zeolite-like materials and other ionexchanging insoluble compounds that can act as detergent builders. Of the various Zeolite A products, Zeolite 4A may often be found to be preferred. Such materials are well known in the art and methods for their manufacture need not be described here. Usually such compounds will be of the formula (Na2O)x. (Al2O3)y .( SiO2 ) z.w H2O wherein x is 1, y is from 0.8 to 1.2, preferably about 1, z is from 1.5 to 3.5, preferably 2 to 3 or about 2, and w is from 0 to 9, preferably 2.5 to 6.

The zeolite builder should be a univalent cation exchanging zeolite, i.e. it should be an aluminosilicate of a univalent cation such as sodium, potassium, lithium (when practicable) or other alkali metal, or ammonium. Preferably the univalent cation of the zeolite type mentioned is an alkali metal cation, especially sodium or potassium and most preferably it is sodium, as was indicated in the preceding formula.

The zeolites, whether crystalline or amorphous, are capable of reacting sufficiently rapidly with calcium ions in hard water so that, alone or in conjunction with other water softening compounds in the detergent composition, they soften the wash water before adverse reactions of water hardness ions with other components of the synthetic organic detergent composition occur.

The zeolites employed may be characterised as having a high exchange capacity for calcium ion, which is normally from about 200 to 400 or more milligram equivalents of calcium carbonate hardness per gram of the aluminosilicate, preferably 250 to 350 mg eg/g, on an anhydrous zeolite basis. Also they preferably reduce the hardness quickly in wash water, usually within the first 30 seconds to five minutes after being added to the wash water, and they can lower the hardness to less than a milligram of CaCO3 per litre within such time. The hydrated zeolites will normally be of a moisture or water of hydration content in the range of 5 to 30%, preferably about 15 to 25% and more preferably 17 to 22%, e.g. about 20%.The zeolites, as charged to a crutcher mix from which base beads may be made, should be in finely divided state, with the ultimate particle diameters being up to 20 microns, e.g. 0.005 to 20 microns, preferably 0.01 to 8 microns mean particle size, e.g. 3 to 7 microns, if crystalline, and 0.01 to 0.1 micron, e.g. 0.01 to 0.05 micron, if amorphous. Although the ultimate particle sizes are much lower, usually the zeolite particles are of sizes within the range of No. 100 to 400 sieve, preferably No. 140 to 325 sieve, as charged to the crutcher for the manufacture of the base beads. In the base beads the zeolite(s) will often desirably be accompanied by a suitable builder salt or salts, e.g.

sodium tripolyphosphate and sodium silicate (in relatively minor proportion), or sodium carbonate and sodium bicarbonate. Sodium silicate may tend to agglomerate with zeolites so the proportion thereof present in zeolite-built base beads may be limited, or the sodium silicate may be omitted, especially from the carbonate-containing formulations, but sometimes as much as 10% may be present in the final detergent compositions, such as when no other suitable binder or anticorrosion agent is present.

Polyacrylate may be used to stabilize the PET-POET copolymer in the particulate compositions and may be a low molecular weight polyacrylate, such as alkali metal polyacrylate, e.g. sodium polyacrylate, the molecular weight of which is usually within the range of about 1,000 to 5,000, preferably being in the range of 1,000 to 3,000 and most preferably being between 1,000 and 2,000, e.g. about 2,000. The mean molecular weight will usually be within the range of 1,200 to 2,500, such as 1,300 to 1,700.Although other water soluble polyacrylates may sometimes be substituted in part for the above described sodium polyacrylate, including some other alkali metal polyacrylates, e.g. potassium polyacrylate, it is preferred that such substitutions, when permitted, be limited to a minor proportion of the material, and preferably, the polyacrylate employed will be an unsubstituted sodium polyacrylate. Such materials are available from Alco Chemical Corporation, under the name Alcosperse (Registered Trade Mark). The sodium polyacrylates are available as clear amber liquids or powders, completely soluble in water, with the solutions being of about 25 to 40% solids contents, e.g. 30%, and with the pH of such solution or of a 30% aqueous solution of a powder being in the range of 7.5 to 9.5.Among these products those preferred are presently sold as Alcosperse 104, 107, 107D, 109 and 149, of which Alcosperse 107D, a 100% solids powder, is highly preferred, although Alcosperse 107, a 30% aqueous solution, may be used instead, with little difference in results (provided that it is dried first). Both are sodium polyacrylates with the liquid (107) being of a pH in the 8.5 to 9.5 range and the pH of the powder (107D) being in the 7.0 to 8.0 range, at 30% concentration in water. The powder is preferably anhydrous but may contain a minor proportion of water, normally less than 10%, which is largely removed during any fusion operation practiced, as when the PET-POET copolymer and the polyacrylate are melted together and then cooled to solidification.

To make the stabilized soil release promoting polymer components of the compositions of the present invention, following normal procedure, the PET-POET polymer may be melted by being raised to a temperature above its melting point and preferably to a temperature in the range of 700 to 1500C, to liquefy it, and there is added to it powdered solid sodium polyacrylate.

When a uniform melt has been obtained it may be cooled and the solidified mass may be size reduced by any suitable means. Preferably, cryogenic grinding or flaking operations will be employed so that the product will be a finely divided powder or flake which will be readily miscible with other particulate powder components of a built detergent composition and will not segregate objectionably from such composition.

Cryogenic size reduction, often undertaken at a temperature below OOC and sometimes below -500C, may be effected by grinding or otherwise size reducing in the presence of liquid nitrogen or other cryogenic material. Alternatively, a suitable grinder, such as a hammer mill, a cage mill or a Raymond Imp Mill may be employed, and instead of liquid nitrogen or other liquid cryogenic coolant, solidified carbon dioxide (dry ice) may be mixed with the resins being ground, or other cooling facilities may be utilized to prevent overheating of the material and to maintain it in cold, readily fracturable form.Instead of the mentioned size reduction devices, others of equivalent functions may be utilized, including the Raymond Ring-Roll Mill, which contains an internal separator and is capable of producing very finely divided resinous materials.

Instead of utilizing cryogenic or low temperature grinding equipment to size reduce the solidified melt of PET-POET and polyacrylate, the melt may be spray cooled to desirably sized beads, which will usually pass through a No. 10 sieve (U.S. Sieve Series), and preferably will pass through a No. 30 sieve.

The products resulting from application of the described processes of the present invention may be considered as PET-POET copolymer carrying polyacrylate.

Because the proportion of the polyacrylate is relatively minor (although its effect is significant) the PET POET copolymer provides a medium for distributing the polyacrylate throughout any detergent composition with which it is mixed. Thus, in addition to the stabilizing effect the polyacrylate has on the PET-POET copolymer, the polymer helps to extend the polyacrylate so that it may be more uniformly distributed throughout the detergent composition and thereby may more uniformly impart to such composition desirable properties of the polyacrylate, which include promotion of clay soil removal from laundry during washing and inhibition of soil redeposition onto the laundry during washing. The "carrying" of the polyacrylate by the stabilized polymer also obviates the need to spray the detergent composition beads or base beads with a solution of polyacrylate to distribute it more evenly throughout the detergent composition.

The stabilized PET-POET copolymers, with the preferred polyacrylate stabilizer in intimate contact therewith, are employed in the present invention for soil release promotion in the described detergent compositions. It has been found that laundry, especially laundry in which the fabrics are of polyesters of polyester blends of fibres (often with cotton), more readily release various soils to the wash water during washing with built synthetic organic detergent compositions, especially those based on nonionic detergents, if the soiling of the laundry takes place after it has been washed with such a detergent composition containing the PET-POET copolymer.Some of the copolymer is held to the laundry during the washing operation, so that it is present thereon when the laundry is subsequently soiled, and its presence promotes the removal of the later applied soil and/or stain during a subsequent washing. It might have been expected that the polyacrylate, in the same particles as the PET-POET copolymer, would promote dispersion of the polymer and inhibit deposition thereof on the laundry but such is not the case. Instead, the polyacrylate increases the soil release promoting activity of the PET-POET polymer in detergent compositions.One mechanism accounting for this increase is the inhibition by the polyacrylate of decomposition or degradation of the polymer when it is subjected to contact with alkaline materials, as in such built detergent compositions in which the builder salt is alkaline (as many of them are), especially at elevated temperatures.

In addition to the NRE, preferred builder and PET POET copolymer, or in addition to the mentioned three components and polyacrylate stabilizer, the invented particulate detergent compositions will usually also contain water (or moisture) and one or more adjuvants.

A wide range of adjuvants may be employed in the particulate products, such as those which are normally present in detergent compositions of various types, but in the present compositions those adjuvants which are preferred include enzymes, such as mixed proteolytic and amylolytic enzymes, fluorescent brighteners, such as stilbene brighteners, colourants, such as dyes and pigments, crutching aids, such as citric materials and magnesium sulphate, and perfumes. In some instances fabric softeners, such as bentonite or quaternary ammonium halides or amines are employed and sometimes flow improving agents, which are often special clays, may be present.Bleaches, such as sodium perborate, and bleach activators, may be included in the present compositions, often in larger proportions than are employed of other adjuvants, and they will usually be most useful in detergent compositions intended for hot water washing. Fillers, e.g. Na2SO4, may also be present.

In the detergent compositions of the present invention, there will normally be present 10 to 35% of the NRE nonionic detergent preferably 15 to 25% thereof, and usually more preferably, about 20%. The builder content will usually be within the range of 30 to 75%, preferably 55 to 70% and most preferably about 58 to 61%, e.g. 58% and 61%. When the detergent composition is a phosphate-built composition the phosphate content will normally be in the range of 30 to 75%, with 0 to 10% of water soluble silicate, preferably 50 to 65% of sodium tripolyphosphate and 2 to 10% of sodium silicate, and more preferably about 58% of sodium tripolyphosphate and about 5% of sodium silicate.For the non-phosphate-built detergent compositions the contents of builders will normally be 30 to 75%, comprised of 15 to 40% of ion exchanging zeolite, 10 to 30% of sodium carbonate and 5 to 20% of sodium bicarbonate, preferably being 55 to 70% total, with 20 to 40% of zeolite, 15 to 25% of carbonate and 5 to 15% of bicarbonate, and more preferably being about 61% total builder, with 30% zeolite (anhydrous basis), 20% carbonate and 11% bicarbonate. The percentages of PET-POET copolymer for both types of detergent compositions will usually be in the range of 0.5 to 10%, preferablay 2 to 6%, more preferably being about 4%, and the percentage ranges for the polyacrylate stabilizer will normally be in the range of 0.1 to 5%, preferably 0.5 to 5%, and more preferably will be about 1%.The proportion of sodium polyacrylate to PET-POET copolymer will normally be within the range of 1:6 to 1:2, preferably being 1:5 to 1:3, and more preferably will be about 1:4. The adjuvants present, except for bleaches and fillers, which may total 5 to 40% of the detergent composition, with the required components being reduced proportionately to compensate, will usually not exceed 10% of the composition, in total, and preferablay will be less than 5% thereof, more preferably being in the range of 1 to 4%, e.g. 2% and 4%, for preferred phosphate-built and non-phosphate particulate detergent compositions, respectively.

Individual adjuvants (other than bleaches, bleach activators and fillers) will normally be less than 2% of the composition, often being less than 1.5% thereof.

To manufacture particulate detergent compositions base beads of inorganic builder may be made by mixing together an aqueous crutcher mix of such builder or builder mixture, usually at a solids content in the range of 40 to 75%, at a temperature in the 400-750C range, and spray drying it in a spray tower at a temperature in the range of 2500 to 4500C, to produce substantially globular beads of particle sizes in the range of No's. 10 to 100, U.S. Sieve Series. If spray drying results in larger and smaller particles also being produced they may be screened or air classified to the desired range, or to another such range considered to be acceptable for the purpose intended.

The spray dried beads, after cooling, then have nonionic detergent in liquid state absorbed therein, by spraying the desired nonionic liquid detergent, in the present case, NRE nonionic detergent, onto moving surfaces of the beads. An advantage of the present invention is that it has been found that the NRE's tend to be liquid or at least, near room temperature (250C) are more readily liquefied by heating than BRE's, and accordingly penetrate better into the interiors of the spray dried base beads, which improves processing and results in freer flowing products.The PET-POET copolymer may be dispersed and/or dissolved in the nonionic detergent and may be absorbed into the spray dried base beads with the nonionic detergent but, especially when polyacrylate stabilizer is employed to improve the soil release promoting properties of the PET-POET copolymer, the copolymer will be co-fused with the polyacrylate, after which the melt may be solidifed, either by spray cooling to particles of sizes similar to those of the base beads, or may be cryogenically or otherwise suitably size reduced to such sizes. See U.S. Patent 4,569,772 (Ciallella, assignor to Colgate-Palmolive Company) hereby incorporated by reference, for a more detailed description of the manufacture of the stabilized copolymer. The nonionic detergent-containing spray dried base beads and the stabilized copolymer may then be blended together and various other adjuvants, not previously incorporated into such components, may be post-added, by mixing and/or spraying, as may be appropriate.

Usuallay, such adjuvants will include enzymes and perfumes, with flow improving agents being optional.

Sometimes, antistatic agents will also be post-added, either as particulate solids or in liquid state. Such post-additions will normally be carried out in a suitable mixing apparatus, such as an inclined drum blender, but usually any suitable type of blending apparatus may be employed.

The invented particulate compositions are employed in essentially the same manner as has been described in U.S. Patent 4,571,303 (Ciallella, assignor to Colgate Palmolive Company), hereby incorporated by reference, and testing for suitability for commercial use is against a wide variety of stains encountered on normal laundry, including dirty motor oil, because a primary advantage of heavy duty or built nonionic detergent compositions is that they are effective in removing oily stains from laundry, especially laundry containing polyester fibrous materials.In testing for efficacy in such applications swatches of the material being tested, such as single knit polyester, double knit polyester, woven polyester and polyester/cotton blends, are prewashed, using a top loading automatic washing machine of 67 litre capacity, water at 150 ppm hardness, as calcium carbonate (mixed calcium and magnesium hardness) in a regular ten minute wash cycle, after which the laundry is rinsed, spin dried and subsequently dried in an automatic laundry dryer (with a 30 minutes drying cycle). Next, the light reflectances of the swatches are read and averaged. Subsequently, the swatches are stained, as by dirty motor oil (usually three drops per swatch) and allowed to age overnight.The next day the reflectances of the stained areas of such fabrics are read and the swatches are washed and dried in the manner previously described, followed by readings of the reflectances of the previously stained areas. If the reflectance of the unstained swatch is Rd1 and that of the stained swatch before washing is Rd2, with the final reflectance being Rd3, the percentage of soil release is [(Rd3-Rd2)/(Rd1-Rd2)] x 100. Of course, averages are taken for a plurality of swatches employed so that the average percentage of soil release for a particular stain on a particular material, for a variety of stains on such material, for a particular stain on a variety of materials or for a variety of stains on a variety of materials, may be found.

The soil release promoting activity of a detergent composition may thus be compared to that of another composition by comparing the percentages of soil release under identical washing conditions.

Normally, cold water washing presents the most difficult test for a detergent composition and accordingly, comparisons under such conditions are considered to be more indicative of the activities of experimental detergent compositions, and such experimental compositions that remove stains and wash best in cold water are often those which are most preferred by consumers. Furthermore, cold water washing is energy conserving, less costly, and within reach of more people in both the industrialized and third world countries, so improved dirt and stain removals under such washing conditions are highly desirable.

By the test described above the NRE nonionic detergent compositions of the present invention improve the soil release promoting effects of the PET-POET copolymer synergistically and significantly, compared to similar cmpositions in which BRE nonionic detergents replace the NRE components. In comparative tests, without the PET-POET copolymer being present the same types of detergent composition show no superiority of the NRE nonionic detergent-containing compositions over the BRE compositions. Thus, it appears clear that the great improvement in soil release promoting effect of the invented compositions (and methods) is due to a coaction of the PET-POET copolymer soil release promoting agent and the NRE nonionic detergent, which coaction or synergism is not obvious from the prior art.

In liquid detergent compositions of this invention one or more fluorescent brightening compound(s) is/are preferably present and is/are one(s) which is/are substantive to the washed laundry and serve(s) to convert invisible radiation to visible light, thereby appearing to whiten laundry surfaces on which it/they has/have been deposited. Such fluorescent brighteners constitute a well-known class of materials in the detergent art and therefore they need not be described at great length herein. Suffice it to say that they will normally be of the stilbene type, and more specifically, they will be of the stilbene sulphonic acid or sulphonic salt type.Among such brighteners employed in the compositions of the present invention are those manufactured by Mobay Chemical Corp. and sold under the trade marks Phorwite HRS and Phorwite BHC, which are, respectively, 4,4'-bis-4-anilino-6 (methylamine)-s-triazin-2-yl amine-2,2'-stilbene disulphonic acid, and 4,4'-bis-(4-phenyl-2N-1 ,2,3- triazol-2-yl)-1,2'-stilbene disulphonic acid, potassium salt. Although the mentioned fluorescent brighteners operate very effectively in the present compositions, it is considered that other types fo substantive brightening agents may be employed instead, without loss of the unexpected beneficial improvement in soil release that is characteristic of compositions of the present invention.

An anionic detergent may also be included in preferred embodiments of the invented liquid detergents to improve the substantivity of the fluorescent brightener, and also to add its detersive properties to the composition (anionic detergents being especially effective in removing particulate soils from fabrics).

The anionic detergent is preferably of the sulphate or sulphonate type, normally being in the form of a water soluble salt, such as an alkali metal salt, e.g. sodium salt. Such detergents are described at length in various texts, including Surface Active Agents (Their Chemistry and Technology) by Schwartz and Perry, and the various annual editions of John W. McCutcheon's Detergents and Emulsifiers. Although higher fatty alcohol sulphates and various other sulphate and sulphonates may be employed, it is preferred that the detergent be a higher alkylbenzene sulphonate, such as one wherein the alkyl is of 12 to 18 carbon atoms.

More preferably, the alkyl is linear and is of 12 to 16 carbon atoms, e.g. dodecyl, and the cation is sodium.

An enzyme component of a composition of the present invention, if present, may be any suitable enzyme which is effective against a type of soil expected to be encountered on laundry to be washed with the liquid detergent. The most important of such enzymes are the proteolytic and amylolytic enzymes, and mixtures thereof are preferable. Such mixtures will normally contain one part of proteolytic enzyme to 0.5 to 2 parts of amylolytic enzyme, with approximately equal proportions often being preferred. A suitable commercial product is that sold under the trademark Alcamyl (Registered Trade Mark), which is manufactured by Novo Industrii, but other products of the Maxatase (Registered Trade Mark) type may also be acceptable.

Enzymes may be compounded with carriers or may be dissolved or dispersed in liquid media to facilitate more accurate weighing and formulation. In the manufacture of the compositions of the present invention it is usually preferred to employ liquid preparations of the mentioned dual enzymes, which dissolve more readily than powders.

A stabilizer or a stabilizing combination is normally present with the enzyme(s); it helps to prevent diminution in enzymatic activity after storage of the liquid detergent composition containing the enzyme or enzyme mixture. Suitable stabilizers include lower carboxylic acid salts, usually of 1 to 3 carbon atoms, which are preferably alkali metal salts, e.g.

sodium salts. Of the lower carboxylic acid salts the formates are preferred, with the most preferred such stabilizer being sodium formate. More preferably, the above mentioned enzyme stabilizer will have with it water soluble calcium and/or magnesium salt(s), preferably salts of strong organic acids, such as calcium chloride, magnesium chloride and/or magnesium sulphate. Such salt(s) form a stabilizing system with the lower carboxylic acid salt(s) and improve stabilization of the enzyme(s) present.

Because it is recognised that not all the desired components of the liquid detergent compositions of this invention are readily soluble in the aqueous medium thereof it is often desirable to employ a co-solvent, to assist in dissolving such components (such as the fluorescent brightener) and to help in preventing stratification of the liquid detergent composition or settling out of components thereof. The co-solvent may also perform an anti-freeze function, helping to maintain the composition uniformly liquid even when temperatures drop below freezing. Preferred Co- solvents are low molecular weight polar organic compounds, which are preferably lower alkanols, such as ethanol or isopropanol, with ethanol (which is normally denatured) being Preferred.Such a cosolvent may be mixed with another solvent, such as a diol or a polyol to make a more complex co-solvent system. Among suitable such diols and polyols are glycerol and glycols.

The water employed may be tap water, distilled water or deionized water, or it may be treated water, such as boiler feed water taken from the boiler feed system of the manufacturing plant. It is normally deisrable that such water be of relatively low hardness, and normally it will be of a hardness less than 100 ppm, as CaCO3, preferably less than 50 ppm, and more preferably, it will be about zero hardness.

Various adjuvants may be included in liquid compositions of the present invention, often like those for the particulate products, of which perfume and colourant will be those most commonly employed. The perfume will normally be lipophilic but will be readily solubilized by the surface active and solvent components of the composition. The colourant may be a water dispersible finely divided pigment but it is usually preferable to employ a water soluble dye or mixture of suitable such dyes, with mixtures of dyes and pigments also being feasible. Other components of the invented composition which might be considered to be adjuvants are alkaline and acidic materials, which may be employed to adjust the pH of the liquid detergent to a desired range. Normally, it will not be necessary to employ both acidic and alkaline materials for pH adjustment but sometimes that may be desirable.

A preferred acidic material is citric acid, which is preferably employed as an aqueous solution, e.g. 50% citric acid in water, and a preferred alkaline neutralizing agent is aqueous sodium hydroxide, which is usually of a 38% Na2O concentration in water.

Another adjuvant that is often preferably employed in the present composition is one intended to inhibit corrosion of metallic equipment in which the composition is stored, processed or transported. Among such anti-corrosion agents the most effective for the present compositions are the alkali metal nitrates, e.g. sodium nitrate.

The proportions of the various components of liquid detergent compositions of the present invention will be held within certain ranges to obtain a product of the desired characteristics, which will be of improved detergency against oily stains, such as dirty motor oil, on a variety of fabrics, especially polyesters and cotton/olyester blends, and which will also be of acceptable appearance and physical characteristics. The major component of the invented liquid detergent compositions is water and the proportion thereof will normally be a sufficiently solubilizing proportion (in conjunction with any cosolvent that may be present) for the NRE, the PET-POET copolymer and any other components of the composition.

The water content will be within the range of 50 to 85%, preferably being 60 to 80%, more preferably being 65 to 75%, and most preferably being 70% or about 70%.

The proportion of NRE will be a detersive proportion, which usually will be in the range of 10 to 30%, preferably being 12 to 20%, more preferably being 14 to 18%, and most preferably being 16% or about 16%. The proportion of PET-POET copolymer will be a soil release promoting proportion, which will usually be in the range of 0.2 to 3%, preferably 0.5 to 2%, more preferably 0.7 to 1.5% and most preferably 1% or about 1%.

When fluorescent brightener or brightener mixture is present the proportion thereof will be a brightening proportion, in the range of 0.05 to 2%, preferably being 0.05 to 0.3%, and more preferably being 0.2% or about 0.2%. The proportion of anionic detergent is a brightener substantivity increasing proportion, within the range of 1 to 10%, preferably being 2 to 5%, and more preferably it will be 3.5% or about 3.5%.

The proportion of enzyme(s) will be an enzymatic proportion, within the range of 0.1 to 5%, preferably 0.3 to 3%, and more preferably it will be 0.8% or about 0.8%. Such proportions are based on the commercially supplied enzymes, including any carriers. The enzyme stabilizer or stabilizing system will be present in a stabilizing proportion, within the range of 0.5 to 6%, preferably 2 to 4%, and more preferably such proportion will be about 3%, e.g. 3.2%.

A co-solvent present will be in a co-solvent proportion within the range of 3 to 15%, preferably being 4 to 10%, and more preferably it will be 5% or about 5%. The total of adjuvant(s) present will be in a range of 0.1 to 5%, preferably 0.2 to 2%, e.g. 1% or about 1%. As to individual adjuvants the content of anti-corrosion compound will be in the range of 0.2 to 2%, preferably 0.3 to 1%, and more preferably will be 0.5% or about 0.5%.The amount of perfume will be in the range of 0.1 to 1.5%, preferably 0.2 to 1%, and more preferably will be 0.35% or about 0.35%. The neutralizing or pH adjusting agents' content will be in the range of 0.05 to 0.5%, preferably 0.1 to 0.3%, and more preferably will be 0.15% or about 0.15%. The content of dye or other colourant can be in the range of 0.00001 to 1%, preferably 0.00002 to 0.01%, and more preferably will be 0.00004% or about 0.00004%.

Liquid soil release promoting liquid detergent compositions in accordance with the invention will normally be cloudy in appearance, and sometimes it may be made translucent. It can intentionally be made opaque, pearlescent, or cloudier by use of appropriate additives. The pH of the product will normally be in the range of 7.3 to 8.1, ideally being about 7.7, and the viscosity will normally be in the range of 65 to 115 centipoises at 250C, preferably being about 90 cp.

Manufacturing liquid compositions in accordance with the invention is relatively simple, with almost no critical operations being rqeuired. Usually, the formula proportion of water or about 80% or more of such proportion is pumped to a mixing vessel or tank and the various components of the detergent composition are serially admixed in the aqueous medium, followed by addition of the balance of the water. Sometimes the co-solvent may be added first and at other times a portion thereof or all of it amy be retained for subsequent addition with the balance of water, at or near the end of the mixing process. In many instances particular components, such as the fluorescent brightener, will first be dissolved in the co-solvent or in a portion of the water containing some or all of the co-solvent.Although such techniques may facilitate more rapid manufacture of the liquid detergent, in desired form and of desired appearance, usuallay the intended product is obtainable without practicing such process variations, except for predissolving of the fluorescent brightener. After admixings of all the other components are completed, the balance of water, if any, may be added, also with stirring, and the pH may be adjusted. After pH adjustment and checking of the viscosity to make sure it is within specifications, the product may be bottled directly.

Using liquid compositions of the present invention is simple and satisfactory, from the user's standpoint, there being little for the consumer to do except to measure out the desired amount of the liquid detergent composition and add it to the wash water in an automatic washing machine. Such machines will hold 60 to 70 litres of water, with about 67 litres being typical, and 1/2 cup of liquid detergent, which corresponds to about 120 grams thereof, will be employed per wash, although such amount may be varied, depending on the washer load and the extent of soiling of the items to be laundered. The laundry (usually about 6.5 lbs or 3 kg, +50%) is added to the wash water and the machine is turned on. The wash water will normally be of a hardness no greater than 300 ppm, as CaCO3, and the water temperature will normally be in the range of 10 to 900C.It is recognized that rarely, if ever, following American practice, will the temperature of the wash water approach boiling, but the washing and soil release promoting processes of this invention are operable at such higher temperatures.

However, best comparative soil release promoting effects are obtained at lower temperatures. Preferably the water hardness will be no higher than 200 ppm, with the range of 100 to 200 ppm being considered normal.

Of course, lower hardness wash waters may also be used.

Within the broad temperature range previously mentioned a preferred range is 10 to 500C and for most significantly improved soil release promotions, and resulting detergencies, compared to those obtained when similar BRE compositions are employed, such range will be 10 to 250C, e.g. about 20 to 210C.

Normally the washing cycle (during which the PET POET copolymer is simultaneously being applied to laundry) will be 5 to 30 minutes, with a rinse cycle of 1 to 5 minutes, when an automatic washing machine is being utilized, and sometimes a plurality, usually 2 or 3, of rinse cycles can be used. Drying times will be between 10 and 60 minutes, with usual drying times being in the 20 to 40 minutes range, and drying will usually be at "normal" drying temperatures of automatic laundry dryers, rather than at "high" settings. Of course, both washing and drying conditions will be determined by the nature of the laundry, the soil and/or stains on it, and the characteristics of the washing and drying apparatuses being used.Top loading automatic washing machines will usually be employed, but side loading machines are also acceptable, and the receited advantages are also obtained when the laundry is hand washed and line dried.

In the washing-treating process it will be highly preferred to add the described liquid detergent composition to the washing machine but it is also feasible to add its various components, alone or in mixtures, to the washing machine, to produce essentially the same wash water composition. The wash water resulting will contain a detersive proportion of NRE and a soil release promoting proportion of PET-POET copolymer.

Such proportions will be in the ranges of 0.01 to 0.1% and 0.0002 to 0.01%, respectively, preferably being 0.01 to 0.05% and 0.0005 to 0.006%, respectively, and more preferably being 0.02 to 0.04% and 0.001 to 0.005%, respectively, e.g. about 0.3% and about 0.003%, respectively. The concentration of fluorescent brightener will be within the range of 0.0001 to 0.01%, preferably 0.0002 to 0.001%, e.g. 0.0003%. The concentration of anionic detergent will be in the range of 0.001% to 0.03%, preferably 0.002% to 0.02%, e.g. about 0.007%. Concentrations of other components of the liquid detergent composition (except water) in the wash water, and ranges thereof, in percentages of wash water, may be obtained by multiplying such exemplified concentrations for the liquid detergent composition by 0.0018, for the ideal concentrations thereof in the wash water, or lower and upper percentage ranges of such concentrations may be calculated by multiplying the liquid deteregnt composition concentrations, in percentages, by 0.0010 (for the lower limit) and 0.0030 (for the upper limit). While, it is more preferred to employ the liquid detergent composition at a concentration in the wash water of about 0.18%, depending on the nature of the laundry such concentration may be within the range of 0.10 to 0.30% or within a narrower preferred range of 0.15 to 0.25%.

The following examples illustrate but do not limit the invention. Unless otherwise indicated, in such examples, in this specification and in the appended claims all parts are by weight and all temperatures are in OC, EAXMPLE 1 ComPonent Percent Sodium tripolyphosphate 57.3 Narrow range ethoxylated higher fatty alcohol* 20.0 Water 10.0 Sodium silicate (Na2O:SiO2 = 1::2.35) 4.5 PET-POET copolymer** 3.6 Mixed proteolytic and amylolytic enzymes 1.3 (Maxatase (Registered Trade Mark) MP) Sodium sulphate 1.1 Fluorescent brightener (Tinopal (Registered 1.0 Trade Mark) 5BM Extra Concentrated) Sodium polyacrylate (Alcosperse (Registered 0.9 Trade Mark) 107D) Colourant (dye mixture) 0.1 Perfume 0.2 100.0 * Condensation product of C12-14 linear alcohol and an average of 6 to 7 moles of ethylene oxide per mole of alchol, with about 88% of the ethylene oxide being in polyoxyethylene groups of 5 to 10 EtO's (Tergitol 24-L-60N, mfd. by Union Carbide Corp.) ** PET-POET copolymer of weight average molecular weight of about 22,000, with molecular weight of the polyoxyethylene being about 3,400 and molar ratio of polyethylene terephthalate to polyoxyethylene terephth alate units being about 3::1 (Alkaril QCF, mfd. by Alkaril Chemicals, Inc., and supplied by them in particulate form, in 4:1 ratio, with sodium polyacrylate, as pre-fused Alkaril Base C.).

A particulate detergent composition of the above formula is made by crutching a 45% solids crutcher mix of the tripolyphosphate, silicate, sulphate, fluorescent brightener and colourant, in tap water, at a temperature of about 600C and spray drying it into hot drying gas at a temperature of about 4000C in a spray tower to form beads of sizes in the range of No's. 10 to 100, U.S. Sieve Series, having a moisture content of 13.5%. After cooling, 74 parts of such base beads are sprayed with 20 parts of the NRE nonionic detergent, in liquid state at elevated temperature, e.g. about 400C, which detergent is absorbed into the beads.Then, 4.5 parts of a 4:1 QCF/Alcosperse blend (in particulate form, of approximately the same particle size as the spray dried beads) and 1.3 parts of the enzyme mixture are mixed with the builder-nonionic detergent beads and subsqeuently the product is perfumed with 0.2 part of liquid perfumebeing sprayed thereon, during all of which operations the.materials are maintained in motion in an inclined drum mixer.

The soil release promoting effect of detergent compositions of the present invention containing the synergistic combination of NRE nonionic detergent and PET-POET copolymer, is measured by the DMO (dirty motor oil) method previously described in this specification.

Test swatches of different materials are first washed in an automatic washing machine with the experimental detergent composition, at a concentration of 0.15%, in 700F (210C) wash water of 150 ppm hardness, as calcium carbonate, followed by automatic drying, staining of the test swatches with three drops of dirty motor oil (DMO) each, aging overnight, and washing again with the experimental detergent composition under the same conditions. Reflectances of the test swatches are read after the first washing, after staining, and after the second washing and the percentages of soil release are calculated according to the formula previously given.

A control composition is made wherein the same proportion of nonionic detergent is used, but it is a BRE (Neodol 25-7) of essentially the same average ethoxylate content and of essentially the same fatty alcohol component, with the only significant difference between the detergents being in the broad range distribution of the ethylene oxide polymer in the BRE detergent and the narrow range distribution thereof in the NRE detergent. For such control product the same base beads and adjuvants are employed, and in the same proportions but the different nonionic detergent is absorbed into such beads.

The following table compares the percentages of soil release (or stain removal) found: TABLE I Soil Released (%) Swatch Fabric Type Experimental Control Dacron double knit 88.7 73.1 Dacron single knit 94.0 91.1 Woven polyester 91.5 80.8 65:35 Dacron:cotton blend 47.3 35.7 50:50 Dacron:cotton blend 32.2 26.7 Nylon tricot 79.4 59.4 Acetate jersey 81.9 72.1 Because a 5% different in soil release is considered significant under the conditions of the test, significant differences were obtained for all the test swatches except the Dacron single knit, but even in that case the experimental is noticeably better than the control. The average improvement is 10.9%. Visual observations of the test swatches are even more convincing of the unexpectedly beneficial soil release promoting effect of the synergistic composition of this invention.It should be kept in mind that the test reported was run with more severe staining than is normally encountered and under washing conditions (cold water) that are considered adverse. Thus, even better soil release is obtainable when warm or hot wash water is employed. Also, when multiple washings, e.g. 2 to 6, with the compositions, precede the spotting with DMO the soil release promoting action of the invented composition is even more pronounced. The soil release actions obtained fro DMO are also obtained when a variety of other oily type soils is employed in the described testing, and the improvements over controls are also of significance.

EXAMPLE 2 Component Percent Sodium zeolite (Zeolite 4A, anhydrous basis) 30.1 Sodium carbonate (anhydrous) 20.1 NRE nonionic detergent* 20.0 Sodium bicarbonate 10.8 Water 9.5 White monomorillonite (anhydrous) 1.4 Enzyme mixture (Maxatase MP) 1.3 Fluorescent brightener (Tinopal 5BM Extra 1.0 Concentrated) PET-POET copolymer** 4.0 Sodium polyacrylate (Alcosperse 107D) 1.5 Perfume 0.2 0.1 100.0 * See Example 1.

** See Example 1 (Alkaril Velvetol 251-C employed instead of Alkaril Base C.).

Two control compositions are made, A and B, with A being the same as the above experimental formula except for the substitution of Neodol 25-7 for Tergitol 24-L60N, and with such BRE substitution also being made in control B, from which the QCF and stabilizing 1% of Alcosperse 107D are omitted (the balance of the Alcosperse 107D is added in the crutcher mix). Test swatches are washed, stained and washed again with the experimental, Control A and Control B compositions, respectively, and the results are compiled in the following table.

TABLE II Soil Release (%) Swatch Fabric Type Experimental Control A Control B Dacron double knit 66.0 27.9 3.6 65:35 Dacron:cotton 40.2 31.8 13.8 blend Nylon tricot 39.3 17.4 26.7 Acetate jersey 48.8 33.5 10.8 The above data show that the experimental formula of this invention is significantly better than either of the control formulae in promoting the release from the described test swatches of a more tenacious oily soil, an even dirtier motor oil than that use for the Example 1 tests. With a 5% difference being considered quite significant, it is evident that very noticeable differences are obtained compared to the better of the controls, in which a BRE nonionic detergent is employed instead of the NRE nonionic detergent of the present invented compositions. Thus, the average improvement in soil release for the four materials listed is 20.9%.

Visual examinations of the test swatches confirm that the soil release promoting activity of the invented composition is far superior to those of the controls.

EXAMPLES 3 and 4 The compositions and controls of Examples 1 and 2, respectively, are made with an NRE nonionic detergent, available from Shell Development Company, which identifies it as 23-7P, being substituted for Tergitol 24-L-60N. Swatch tests like those of Examples 1 and 2 show such detergent compositions to be essentially equivalent in soil release promoting actions to the experimental compositions of Examples 1 and 2, respectively, which establishes that Shell's 23-7P, which is within the scope of the description of the NRE's of the present invented compositions, also synergistically improves the soil release promoting activity of PET-POET copolymers in the present compositions.

EXAMPLES 5 and 6 The compositions and controls of Examples 1 and 2, respectively, are made with an NRE nonionic detergent, available from Shell Development Company, which identifies it as 23-7Z, being substituted for Tergitol 24-L60N. Swatch tests like those of Examples 1 and 2 show such to be essentially equivalent in soil release promoting actions to the experimental compositions of Examples 1-4, which establishes that Shell's 23-7Z, which is within the scope of the description of the NRE's of the present invented composition, also synergistically improves the soil release promoting activity of PET-POET copolymers in the present compositions.

Similar results are obtainable by employing a Shell Development Company narrow range ethoxylate designated Neodol 23-6.5 NRE, which is the narrow range ethoxylate that may be compared to Neodol 23-6.5, a product of Shell Chemical Company (which product is a BRE). Also, mixtures of the mentioned substitute NRE nonionic detergents may be made, and comparable improvements in soil release promotion will be observed.

EXAMPLE 7 Various changes may be made in the compositions and methods of Examples 1-6 without departing from the present invention. Thus, in the washing operations the concentrations of detergent composition employed may be varied within the range of 0.05 to 0.3%, depending on wash water hardness and temperature, washing machine type and design, laundry type, and dirtiness of the laundry being treated and washed. Diffeent builders, PET-POET polymers, polyacrylates, fillers, enzymes, and other adjuvants may be employed, as well as various mixtures thereof.Different mixtures of narrow range ethoxylate nonionic detergents may be employed and individual proportions of components of the invented detergent compositions may be changed +10%, +20% and +30%, providing that they are within the ranges and descriptions set forth in the specification. While anionic detergents will normally not be present in the invented compositions, their presence, up to a reasonable limit, say 10% of such a composition, may sometimes be desirable. Of the anionic detergents those which are most preerred are the linear higher alkyl benzene sulphonates, the higher fatty alcohol sulphates and higher fatty alcohol polyethoxy sulphates, preferably as sodium salts and with the alkyls and alcohols being of 10 to 18 carbon atoms, more preferably, of 12 to 14 carbon atoms.

When the modifications of the formulae of Examples 1-6 are made, as mentioned herein, the compositions resulting and the methods being practiced are effective in promoting soil release from various synthetic organic polymeric textiles (especially polyesters) and from synthetic/natural fibre blends. However, it is important that the nonionic detergents that are in such compositions and that are employed in such methods be of NRE type, as previously described, and be present in proportions within the ranges mentioned herein.

EXAMPLE 8 Component NRE Tergitol Nonionic Surfactant 24-L-60N* 16.00 Alkaril QCJ (15% aqueous solution)** 6.67 Fluorescent brightener*** 0.16 Sodium linear dodecylbenzene sulphonate (52.5% 6.67 active ingredient, in aqueous solution) Enzyme mixture (Alcamyl) 0.75 Calcium chloride dihydrate 0.17 Sodium formate 3.00 Sodium nitrate 0.50 Blue dye (CI Acid Blue 182, 0.38% aqueous 1.00 solution) Ethanol (denatured with methanol) 5.41 Perfume 0.35 Sodium hydroxide (38% aqueous Na2O solution) q.s.

for pH adjustment Citric acid (50% aqueous solution), for pH q.s.

adjustment Water (softened)**** 59.32 100.00 * A narrow range ethoxylate nonionic detergent which is a condensation product of higher fatty alcohol of 12-14 carbon atoms and an average of 7 moles of ethylene oxide per mole, with over 90% thereof of 4-10 ethoxylate groups per mole.

** Polyethylene terephthalate-polyoxyethylene terephthalate copolymer of molecular weight of about 22,000, polyoxyethylene molecular weight of about 3,400, and molar ratio of polyethylene terephthalate to polyoxyethylene terephthalate units of about 3:1.

*** Stilbene-type fluorescent brighteners (0.118 of Phorwite (Registered Trade Mark) RKH and 0.05% of Phorwite BHC, both mfd. by Mobay Chemical Co.; any of such brighteners may be substituted but they will preferably be of a stilbene sulphonate or stilbene sulphonic acid type).

**** The percentage given is for compositions to which neither sodium hydroxide nor citric acid has been added (for pH adjustment). If either is employed, the percentage of water is decreased accordingly. Note that the percentage of water in the final liquid detergent composition is greater than indicated because some water accompanies various components.

A liquid detergent of the above composition is made by admixing all the components with the water in any suitable order, so long as the fluorescent brightener is dissolved early in the manufacturing process.

Either sodium hydroxide solution or citric acid solution is addednear the end of the mixing process to adjust the pH, either upwardly or downwardly, as may be required, and the perfume is normally added after pH adjustment is effected. Optionally, the abovementioned components, some of which may be dissolved in the co-solvent or in aqueous co-solvent, may be admixed with a suitable proportion of the formula amount of water (such as 1/2 or 4/5), and the balance of water may be added last or shortly before pH adjustment and/or perfume addition.

The product resulting is a blue liquid, which is cloudy or translucent in appearance and which is of a viscosity of 90 centipoises at 250C, measured with a Brookfield (RV) viscosimeter, using a No. 1 spindle, rotating at 20 revolutions per minute. The pH of the product is 7.7. The liquid detergent composition made is stable at room temperature for at least six months and often for a year or longer, without any stratification or settling out of components, and the soil release promoting activity of the PET-POET copolymer component remains high after storage, apparently due to the presence in the product of the NRE. If a BRE is substituted for the NRE substantial diminution in soil release promoting activity is noted after storage.

The liquid detergent composition of the invention is tested for soil release promoting effect against a control composition, identical therewith except for replacement of the Tergitol Nonionic Surfactant 24-L60N by Neodol 25-7. Following is a description of the test procedure, using a normal wash water concentration of the liquid detergent compositions, 0.18%.

In the Tergotometer (Registered Trade Mark) laboratory washing machine three rectangular polyester double knit swatches, each measuring 7.6 x 10.2 cm, are pre-washed once together in one litre of wash water of 150 ppm hardness, as CaCO3, for ten minutes at a temperature of either 210C (cold water washing) or 380C (warm water washing), as desired. At the conclusion of washing the swatches are hand rinsed for about ten seconds, and are dried, and after drying reflectance readings are taken, using a reflectometer (Gardner XL20, for example). The average reflectance reading for the three swatches is taken as Rd (initial). The three swatches are then stained with three drops of dirty motor oil each and are allowed to age overnight.

Reflectance readings are again taken and the average is Rd (stained). The pre-wash procedure is followed in washing the stained swatches and reflectance readings are again taken and are averaged, with the average being identified as Rd (washed). The percent of soil release obtained is calculated as Rd (washed - Rd (stained) X X 100.

Rd (initial) - Rd (stained) Instead of employing the laboratory washing machine, a conventional home laundry washing machine may be utilized, with the same procedure being followed except that the swatches may sometimes be of a variety of fabric types, and will usually be larger in size, e.g. 10.2 x 15.2 cm, the wash water volume will be greater, e.g. 64.3 litres and the washing machine will be set for a normal ten minutes washing cycle, with accompanying normal rinse and spin cycles. The charge of liquid detergent composition in such tests is 1/2 cup per wash, which is 0.18%, based on the wash water.

The percent of soil release for the invented composition of the preceding formula is 74.2% (210C) while that for a control, an identical formula except for replacement of the Tergitol Nonionic Surfactant 24 L-60N by Neodol 25-7, is only 54.4%. The difference is considered to be very significant and there is no other apparent explanation for it except that the NRE and the PET-POET copolymer unexpectedly and beneficially act together to improve soil release promoting characteristics of the liquid detergent composition, so that oily soil, which may contain particulate materials, e.g.

dirty motor oil, is removed significantly better from polyester and polyester blend fabrics by the invented liquid detergent composition than by similar compositions based on broad range ethoxylate nonionic detergents.

To make sure that the apparent synergism did not result from the Tergitol 24-L-60N being a soil release promoting agent, in and of itself, further control experiments were run, duplicating the experimental and control runs described above except for omissions of the Alkaril QCJ from the formulas. In such cases the percentage of soil release for the double control (that based on Neodol 25-7) was 7.4% and the percentage of soil release for the Tergitol 24-L-60N formula, without Alkaril QCJ, was 7.5%.

From the above data it is clear that the NRE detergent alone does not promote soil release any more than does the BRE detergent alone but the combination of NRE and PET-POET copolymer substantially improves soil release by the copolymer. Such improvement is unexpected and significant. The differences in the cleanings of the swatches are apparent to untrained viewers, and it does not require employment of sensitive measuring instruments to verify such differences.

When the laboratory test is repeated in a conventional washing machine substantially the same results are obtained. However, when the washing temperature is changed from 210C to 380C no appreciable differences in soil release promotion are apparent, but this may be due to the fact that at such higher wash water temperature the percentages of soil release are over 90% and therefore are near their maxima. It is considered that in cases where the fabrics are more severely soiled or stained than in the experiment described above the NRE QCJ formulas will be significantly better in promoting soil release than the BRE-QCJ formulas.

EXAMPLE 9 The laboratory washing tests of Example 8 are repeated, but the test swatches are of nylon tricot and 65/35 polyester/cotton blend. In the 210C tests the invented composition releases 56.6% of the soil from the nylon whereas the control composition releases only 37.1%. The invented composition releases 57.4% of the soil from the polyester/cotton blend whereas the control releases only 49.7%. The differences at 380C are similar, with the invented composition testing the control by releasing 56.3% of the stain from the nylon compared to 47.8% for the control and releasing 52.0% from the blend of polyester/cotton, compared to 35.9% for the control. Furthermore, the differences in soil release are apparent to the naked eye.

The above example shows that the unexpected improvement in soil release characteristics of an invented composition, compared to a similar BRE composition, is not limited to polyester fabrics but applies also to nylon and polyester/cotton blend fabrics.

EXAMPLE 10 The testing procedure of Example 8 is repeated, but with both aged and new detergent compositions being employed, and with the washing being washing in a laboratory washing machine with the wash water at 380C.

Using newly made liquid detergent compositions, the invented composition releases 92.4% of the soil from the polyester fabric while the control composition releases 90.1%. Thus, the liquid detergent compositions are of substantially the same soil release promoting effects under such conditions. However, after accelerated agings of the detergent compositions for one week at 440C (110 F) there is a dramatic difference, with the experimental product removing 88.6% of the soil whereas the control removes only 81.2%. Thus, it was found that the control deteriorates more rapidly in soil release promoting activity than does the liquid detergent composition of the invention.

The reported experiment also indicates that to maintain the soil release promoting activity of this type of liquid detergent composition it is important to employ NRE nonionic detergents, rather than BRE detergents. It was previously known that PET-POET copolymers in the present type destabilized by triethanolamine, which -is employed in some liquid detergent compositions for its solubilizing effect on fluorescent brighteners, and it was known that ionizable salts also tend to have such a destabilizing effect. Therefore, the triethanolamine (TEA) content of PET-POET-containing liquid detergent compositions was minimized or the TEA was omitted entirely, and ionizable salt content was limited.Usually, for good soil release promoting action in NRE-PET-POET liquid detergent compositions the amount of TEA present should be limited to 1%, preferably to less than 0.5% and more preferably it will be omitted. With respect to ionizable salts, the concentration thereof should normally be limited to 10%, preferably 5% and more preferably 1% or less. For the compositions of this specification and of this example the content of ionizable salt will desirably be similarly limited, preferably to 5 or 10% of ionizable salt (1% when sodium formate and anionic detergent are not counted) and 0.1 or 0.2% TEA (but omitting it entirely is preferred).

Although the data presented in this example are with respect to testing at 380C it is considered that they are representative of the data that are obtained when the testing is at higher and lower temperatures, such as 210C. Also, these data are considered to be consistent with results obtained after shelf storage of the liquid detergent composition for six months and for a year, or after accelerated agings for one or two months. However, after longer periods of storage or storage at higher temperatures the soil release promoting activity will be further diminished, so it is important that products to be marketed should be of highest initial soil release promoting effects, so that even when such effects are diminished the soil release promoting performance will be acceptable to the consumer.

EXAMPLE 11 When variations are made in the basic formula of Examples 8-10, with replacement of the Tergitol 24-L60N with comparable NRE's, such as 24-L-45N, 24-L-50N and 24-L-75N, essentially the same types of results are obtainable. Similarly, other NRE's, such as Shell 237P and Shell 23-7Z may be substituted, with similar results being obtainable in at least some such cases.

Some variations may also be made in the PET-POET copolymer, such as increasing the weight average molecular weight thereof so that it is in the range of 30,000 to 40,000, and the desirable soil release promoting activities will be obtainable. Instead of the specified anionic detergent others may be employed, such as sodium lauryl sulphate, and other comparable alkylaryl sulphonates and alkyl sulphates. Different enzymes, enzyme stabilizers, copolymer stabilizers, cosolvents, fluorescent brighteners, dyes and perfumes may be employed, in accordance with the teachings of the specification. Similarly, the proportions of various components for the compositions of these examples, starting with Example 8, may be varied, such as +10%, +20% and +30%, so long as they are kept within the ranges of proportions previously specified. In such cases the desirable effects of the invention will still be obtained.

The invention has been described with respect to working examples and illustrations thereof but it isnot to be limited to these because it is evident that one of skill in the art, with the present specification before him, will be able to utilize substitutes and equivalents without departing from the invention.

Claims (30)

1. A detergent composition comprising a narrow range ethoxylate (NRE) nonionic detergent, which is a polyethoxylated lipophile, ethoxylated with an average of 5 to 10 ethylene oxide groups per mole, and with at least 70% of the ethylene oxide being in polyethoxy groups of 4 to 12 ethylene oxides, and a polyethylene terephthalate-polyoxyethylene terephthalate (PET-POET) copolymer.

2. A detergent composition according to Claim 1, which is in particulate solid form.

3. A detergent composition according to Claim 1, which is in liquid form.

4. A detergent composition according to Claim 2, which is in particulate form and which comprises a building proportion of builder for the nonionic detergent.

5. A detergent composition as claimed in claim 4, wherein the builder is an inorganic builder.

6. A detergent composition according to any one of Claims 1 to 4, wherein the nonionic detergent is a condensation product of a higher fatty alcohol and ethylene oxide, with the ethylene oxide being in polyethoxy groups averaging 6 to 9 ethylene oxide groups per mole, and with at least 70% of the ethylene oxide being in higher fatty alcohol ethoxylates of 5 to 10 ethylene oxide groups per mole.

7. -A detergent composition according to any one of Claims 1 to 6, wherein the PET-POET copolymer is of a weight average molecular weight in the range of 15,000 to 50,000.

8. A detergent composition according to Claim 6, wherein the higher fatty alcohol of the nonionic detergent is of 12 to 14 carbon atoms and is saturated.

9. A detergent composition according to Claim 5, wherein the builder comprises sodium tripolyphosphate, sodium carbonate, sodium bicarbonate, sodium silicate, ion exchanging zeolite or a mixture thereof.

10. A detergent composition according to any one of Claims 1 to 9, wherein the polyoxyethylene of the polyoxyethylene terephthalate of the PET-POET copolymer is of a molecular weight in the range of 1,000 to 10,000.

11. A detergent composition according to any one of Claims 1 to 10, comprising a stabilizing proportion of a polyacrylate stabilizer for the PET-POET copolymer, which inhibits degradation of the copolymer and accompanying loss of soil release promoting action, which otherwise occur as a result of storage at elevated temperatures and in the presence of alkaline materials.

12. A detergent composition according to any one of Claims 1 to 11, wherein over 85% of the ethylene oxide content of the narrow range ethoxylate nonionic detergent is present in C12-14 higher fatty alcohol polyethoxylates of 4 to 12 ethylene oxide groups per mole.

13. A detergent composition according to any one of Claims 1 to 12, wherein the nonionic detergent is 10 to 35% of the composition.

14. A detergent composition according to any one of Claims 1 to 13, wherein the builder is 30 to 75% of the composition.

15. A detergent composition according to any one of Claims 1 to 14, wherein the PET-POET copolymer is 0.5 to 10% of the composition.

16. A detergent composition according to any one of Claims 1 to 15, wherein the polyacrylate when present is sodium polyacrylate and is 0.1 to 5% of the composition, and the proportion of sodium polyacrylate is 1/6 to 1/2 of the proportion of PET-POET copolymer.

17. A detergent composition according to Claim 6 wherein over 85% of the ethylene oxide present in the C12-14 higher fatty alcohol narrow range ethoxylate nonionic detergent is present in such detergent as polyethoxy groups of 5 to 10 moles of ethylene oxide per mole of such nonionic detergent.

18. A detergent composition according to Claim 4, wherein the percentages of narrow range ethoxylate nonionic detergent, soil release promoting PET-POET copolymer, and builder are in the ranges of 10 to 35%, 0.5 to 10% and 30 to 75%, respectively, and the builder comprises 30 to 75% of alkali metal tripolyphosphate and 0 to 10% of water soluble alkali metal (M) silicate of M2O:SiO2 ratio in the range of 1:1.6 to 1:3, with such percen-tages and the M2O:SiO2 ratio being by weight of anhydrous material and on a final composition basis.

19. A detergent composition according to Claim 17 comprised of a mixture of spray dried base particles of sodium tripolyphosphate with or without sodium silicate therein, into which base particles the narrow range ethoxylate nonionic detergent has been absorbed, and particles of a solidified melt of PET-POET copolymer and polyacrylate stabilizer for such copolymer.

20. A detergent composition according to Claim 4 wherein the percentages of narrow range ethoxylate nonionic detergent, soil release promoting PET-POET copolymer, and builder are in the ranges of 10 to 35%, 0.5 to 10% and 30 to 75%, respectively, and the builder comprises 15 to 40% of ion exchanging zeolite, 10 to 30% of sodium carbonate and 5 to 20% of sodium bicarbonate, with such percentages being by weight of anhydrous material and on a final composition basis.

21. A detergent composition according to Claim 17 comprised of a mixture of spray dried base particles of hydrated Zeolite A, sodium carbonate and sodium bicarbonate into which base particles the narrow range ethoxylate nonionic detergent has been absorbed, and, particles of a solidified melt of PET-POET copolymer and polyacrylate stabilizer for such copolymer.

22. A soil release promoting detergent composition according to Claim 3, which is in liquid form and which comprises water as a medium for the NRE and PET POET copolymer.

23. A liquid detergent composition according to Claim 22 wherein the NRE is a higher fatty alcohol ethoxylate condensation product of a higher fatty alcohol and ethylene oxide, with the higher fatty alcohol being of 12 to 16 carbon atoms and the ethylene oxide being in polyethxy ethanol groups averaging 4 to 10 ethoxy groups per mole, with at least 80% of the NRE being higher fatty alcohol ethoxylates of ethoxy contents in the range of 4 to 10 ethoxy groups per mole, the PET-POET copolymer is of a weight average molecular weight in the range of 15,000 to 50,000, and the proportions of such NRE, PET-POET copolymer, and water in such liquid detergent composition are in the ranges of 10 to 30%, 0.2 to 3%, and 50 to 85%, respectively.

24. A liquid detergent composition according to Claim 23 in which the NRE is a condensation product of a saturated higher fatty alcohol of 12 to 15 carbon atoms and an average of 5 to 9 moles of ethylene oxide per mole of such higher fatty alcohol, in polyethoxy ethanol groups, with at least 85% of the NRE being higher fatty alcohol ethoxylates of ethoxy contents in the range of 4 to 10 ethylene oxide groups per mole, and the polyoxyethylene of the polyoxyethylene terephthalate of the PET-POET copolymer is of a molecular weight in the range of 1,000 to 10,000.

25. A liquid detergent composition according to Claim 24 which comprises 12 to 20% of a NRE which is a condensation product of a saturated higher fatty alcohol of 12 to 14 carbon atoms and an average of 6 to 8 moles of ethylene oxide per mole of such higher fatty alcohol, in polyethoxy ethanol groups, with at least 90% of the NRE being higher fatty alcohol ethoxylates of ethoxy contents in the range of 4 to 10 ethylene oxide groups per mole, 0.5 to 2% of PET-POET copolymer, a brightening proportion, within the range of 0.05 to 2%, of a fluorescent brightening compound, a fluorescent brightener substantivity increasing proportion of an anionic sulphate and/or sulphonate detergent, within the range of 1 to 10%, an enzymatic proportion, within the range of 0.1 to 5%, of an enzyme, a stabilizing proportion, within the range of 0.5 to 6%, of a stabilizer or a stabilizing system for the enzyme, a co-solvent proportion, within the range of 3 to 15%, of a polar organic co-solvent for the non-aqueous components of the liquid detergent composition, 60 to 80% of water, and any balance of adjuvant(s).

26. A liquid detergent composition according to Claim 25 in which the NRE is a condensation product of a saturated higher fatty alcohol of 12 to 14 carbon atoms and ethylene oxide, averaging about 7 moles of ethylene oxide per mole of such higher fatty alcohol, the PET-POET copolymer is of a molecular weight in the range of 19,000 to 43,000, the fluorescent brightening compound is a stilbene brightener, the fluorescent brightener substantivity increasing anionic sulphate and/or sulphonate detergent is an alkali metal higher alkylbenzene sulphonate wherein the higher alkyl is of 12 to 18 carbon atoms, the enzyme is a mixture of proteolytic and amylolytic enzymes, the enzyme stabilizer includes an alkali metal lower carboxylic salt of 1 to 3 carbon atoms, the polar organic co-solvent is lower alkanol, the water is soft water, of a hardness less than 50 ppm, as CaCO3, the adjuvants include perfume and colourant, and the proportions of such components in the liquid detergent are in the ranges of 14 to 18%, 0.7 to 1.5%, 0.05 to 0.3%, 2 to 5%, 0.3 to 3%, 0.05 to 0.3%, 2 to 4%, 4 to 10%, 65 to 75%, and 0.2 to 2%, respectively, in which liquid detergent composition the pH is in the range of 7.3 to 8.1 and the viscosity is in the range of 65 to 115 centipoises at 250C, and the PET-POET soil release promoting copolymer is stable on storage.

27. A liquid detergent composition according to Claim2 12 which is free of triethanolamine and of triethanolamine salts, and comprises no more than 10% of ionizable salt(s).

28. A soil release promoting detergent composition of improved soil release promoting properties in cold water washing of polyestercontaining fabrics that have been soiled with oily soils, which improved soil release is due to the presence therein of narrow range ethoxylate (NRE) nonionic detergent and soil release promoting polyethylene terephthalate-polyoxyethylene terephthalate (PET POET) copolymer instead of broad range ethoxylate (BRE) nonionic detergent and PET-POET copolymer, which comprises a detersive proportion of such a NRE type of a nonionic detergent, which is a polyethoxylated lipophile, ethoxylated with an average of 5 to 10 ethylene oxide groups per mole, and with at least 70% of the ethylene oxide being in polyethoxy groups of 4 to 12 ethylene oxides, and a soil release promoting proportion of PET-POET copolymer soil release promoting agent.

29. A detergent composition substantially as herein described with reference to any one of the Examples.

30. A method of washing laundry and imparting soil release promoting properties to it which comprises repeatedly washing such laundry in wash water containing a soil release promoting proportion of a detergent composition as claimed in any one of claims 1 to 29.