NO160217B - LIQUID DETERGENT. - Google Patents

Description

The invention relates to liquid detergents and more

in particular such detergents which contain a soil-releasing polymer which is deposited on polyesters and polyester-mixed materials during washing of these and promotes the release from these of subsequently applied lipophilic dirt. The liquid detergent may preferably include an enzyme to facilitate cleaning together with a stabilizer for the enzyme and may also include a fabric softening compound, such as a quaternary ammonium salt. It is surprising that they exist

end detergents are physically and functionally stable upon storage even when they contain an enzyme or enzymes and a fabric softener or fabric softeners.

Liquid detergents have been used for washing household clothing items in washing machines and have often been applied to soiled areas of the laundry, such as shirt collars,

before washing. The use of copolymers of polyethylene terephthalate and polyoxyethylene terephthalate in detergents as soil release promoting agents has been described in various patents, and some of these relate to liquid detergents. However, the described liquid detergents are not of the same type as according to the present invention because the detergents according to the patents contain triethanolamine and/or ionizable, water-soluble salts (other than anionic surfactants) which are prone to cause separation of the liquid detergent and destabilize the dirt release promoting polymer during storage so that it becomes less effective in promoting the release of dirt afterwards.

In liquid detergents, enzymes tend to lose their activity on storage unless they are stabilized, e.g. with salts, e.g. sodium formate, glycols, e.g. propylene glycol, or other such materials. The aforementioned salts, however, tend to destabilize quaternary ammonium halide fabric softeners and the soil-release-promoting copolymer agents which constitute desired components in the present liquid detergents, and such destabilization of the soil-release agent is particularly strong in the presence of lower alkanolamines or salts thereof, such as triethanolamine (TEA), the presence of which should be avoided. It was therefore surprising that the present liquid detergents could be produced in a clear and stable non-separating form with the various functional components in them effective after storage at elevated temperatures.

According to the invention, a dirt release-promoting, stable, aqueous, liquid detergent is provided which contains 20-50% by weight of a non-ionic surfactant or

a mixture of non-ionic and anionic surfactants, 1-5% by weight of a dirt-releasing polymer of polyethylene terephthalate and polyoxyethylene terephthalate with a total molecular weight of 15,000-50,000, the molar ratio between polyethylene terephthalate units and polyoxyethylene terephthalate units in the polymer being within the range 2:1-6:1 and the polyoxyethylene terephthalate has a molecular weight in the range of 1000-10000, and an aqueous medium in which the pH is 6-9, and the soil release-promoting, stable, aqueous, liquid detergent is characterized in that it contains no more than 2% by weight of water-soluble , ionizable salt that is not an anionic, surface-active, water-soluble salt.

Preferred such liquid detergents also contain enzymes and enzyme stabilizers, and it is even more preferred that a fabric softener is also present.

Although various synthetic, organic, nonionic surfactants with satisfactory physical properties can be used, including condensation products of ethylene oxide and propylene oxide with each other and with hydroxyl-containing bases,

such as nonylphenol or alcohols of the Oxo type, it is strongly preferred to obtain the best results that the nonionic surfactant is a condensation product of ethylene oxide and a higher fatty alcohol. In such products, the higher fatty alcohol has 10-20, preferably 12-15 or 16, carbon atoms,

and the non-ionic surfactant contains 2 or 3-20 or 30, preferably 6-11 or 12, ethylene oxide groups per molecule. Even more preferably, the nonionic surfactant will be a

surfactant in which the high fatty alcohol has 12-15 or 12-14 carbon atoms and which contains 6 or 7-11, e.g. 7, molecules of ethylene oxide. Among such surfactants can be mentioned Alfonic<®> 1214-60 C and "Neodol" 23-6.5 and 25-7. Among their particularly appealing properties, in addition to good detergency in terms of oily and greasy dirt deposited on items to be washed and excellent compatibility with the polymeric dirt release agents used in the present detergents, is compatibility with soluble anionic surfactants of the types linear higher alkylbenzene sulfonates and higher fatty alcohol polyethoxylate sulfates, enzymes , enzyme stabilizers, fabric softeners and other ingredients in the present detergents, and long-term viscosity stability in aqueous and aqueous-alcoholic solutions.

The anionic surfactant that can be used in the liquid detergents is preferably a higher linear alkylbenzene sulphonate or a higher fatty alcohol polyethoxylate sulphate. Normally, water-soluble salts of such materials are preferred, such as the alkali metal salts, and among these the sodium salts are normally preferred over the potassium salts. When the anionic surfactant is a sodium higher alkylbenzene sulphonate, the higher alkyl group will normally have 10-18, preferably 12-16, and more preferably 12 or 13, e.g. 12, carbon atoms. When such an anionic surfactant is a higher fatty alcohol polyethoxylate sulfate, as is the case for those enzyme-containing liquids in which the surfactant increases detergency and promotes increased adhesion of a fluorescent whitening agent present, the higher fatty alcohol will have 10-20, preferably 12-16, and more preferably 12-13 or 12-15, carbon atoms, and the polyethoxylate will include 1,2 or 3-20, preferably 3-10, and more preferably 3-6 or 7, e.g.

3, 6,5 or 7, ethoxy groups. Although not preferred, mixtures of such anionic surfactants can be used in the present detergents which do not contain enzymes, as a rule in a ratio of 1:10-10:1, e.g. 1:2-2:1. Anionic surfactants and surfactants will normally be omitted from the fabric softening liquid detergents.

The dirt-releasing polymer which constitutes an essential component in the detergents according to the invention is a polymer of polyethylene terephthalate and polyoxyethylene terephthalate which is soluble (preferred) or dispersible in water and can be deposited from washing water containing the surfactant or surfactants, on synthetic, organic, polymeric fiber materials , especially polyesters and polyester blends,

so that these are imparted with dirt-releasing properties, while they are kept comfortable for the wearer of clothes made from such materials and do not prevent or significantly inhibit steam penetration through such clothes. Such polyesters have also been shown to exhibit antigen re-deposition properties and often facilitate the removal of stains from substrates. They tend to keep dirt, especially oily or greasy dirt, dispersed in the wash water during washing and rinsing so that this is not redeposited on the laundry. Such useful products are copolymers of ethylene glycol or another suitable starting material with ethylene oxide groups, polyoxyethylene-

glycol or terephthalic acid or any starting material for the terephthalic acid group. The copolymers can

are also considered condensation products of polyethylene terephthalate, which can sometimes be referred to as an ethylene terephthalate polymer, and polyoxyethylene terephthalate. While the terephthalic acid group is preferred as the only dibasic acid group in the polymer, the invention also aims to use relatively small proportions of isophthalic acid and/or orthophthalic acid (and occasionally also other dibasic acids) to modify the polymer's properties. However, the proportions of such acids or starting materials for such supplementary groups which are added to a reaction mixture, and the corresponding proportions in the final polymer will normally each amount to less than 10% of the total phthalic groups present, and they will preferably amount to less than 5%

of these.

The molecular weight of the polymer lies within the range 15,000-50,000, preferably 19,000-43,000, and more preferably 19,000-25,000, e.g. about. 22000. Such molecular weights are weight-average molecular weights as opposed to number-average molecular weights, which in the case of the present polymers are lower. In the polymers used, the polyoxyethylene will have a molecular weight of 1000-10000, preferably 2500-5000, and more preferably 3000-4000, e.g. about. 3400. In such polymers, the molar ratio between polyethylene terephthalate and polyoxyethylene terephthalate units (since

are considered such units) lie within the range of 2:1-6:1, strongly preferred 5:2-5:1, and even more preferably 3:1-4:1, e.g. about. 3:1. The ratio between ethylene oxide and phthalic group in the polymer will be at least 10:1 and often 20:1 or more, preferably within the range 20:1-30:1, and more preferably approx. 22:1. It thus appears that the polymer can essentially be regarded as a modified ethylene oxide polymer in which the phthalic group only constitutes a minor component thereof, regardless of whether calculated on a mole basis or a weight basis. It is considered surprising that with such a small proportion of ethylene terephthalate or polyethylene terephthalate in the polymer

is the polymer sufficiently similar to the polymer in the polyester fiber substrate (or other polymers to which it can adhere, such as polyamides) that it will be retained on these during the washing, rinsing and drying operations. As shown by means of comparison tests and various washing tests where the release of dirt is measured, the described polymer in the present detergents will nevertheless be effectively deposited on washed synthetic goods, especially polyesters, so that these are better able to be washed free of oily dirt by means of a liquid non-ionic surfactant-containing detergent or another surfactant-containing product. It is believed that the increased hydrophilicity of the polymer attributable to the large proportion of hydrophilic ethylene oxide groups therein may be responsible for the excellent soil release properties (for the release of lipophilic dirt) that it imparts to the material on which it is deposited, and this may also help it to cooperate with the liquid nonionic detergent product components.

Various literature articles, textbooks and patents describe methods for producing the present polymers, and among these can be mentioned Journal of Polymer Science, Vol. 3 pp. 609-630 (1948) and Vol. 8, pp. 1-22 (1951). Although suitable methods for the preparation of the present polymers are described in such references, none of these are considered to describe the particular polymers used in the present detergents (although such are commercially available),

and none of these describe the present detergents.

Such polymers can be considered as randomly built up of polyethylene terephthalate and polyoxyethylene terephthalate groups, which can be achieved by reacting polyethylene terephthalate (e.g. of spinning grade) and polyoxyethylene terephthalate

or by reacting ethylene glycol-, polyoxyethylene glycol-

and the acid (or methyl ester) precursors thereof. However, the invention also aims to use more ordered copolymers, such as those produced by reacting components with previously determined or known chain lengths or molecular weights, in order to thereby produce what can be described as block copolymers or non-random copolymers. Graft polymers can also be used.

The described materials are available from different suppliers, and the products from one of these will be described in more detail here. Useful copolymers for the production of the detergents according to the invention are marketed by Alkaril Chemicals, Inc., and commercial products from this company which have been used with good results to produce satisfactory soil release promoting detergents are those sold under the trademarks Alkaril QCJ and Alkaril QCF, formerly Quaker QCJ and Quaker QCF. Products available from these in limited quantities and with the quality designations 2056-34B and 2056-41 have also been found to be acceptable. The QCJ product which is normally sold in the form of an aqueous dispersion with a concentration of 14 or 15% in water and which is preferably used to prepare the present liquid detergents, is also available as a substantially dry solid material (QCF). In both types of products, the molar ratio between ethylene oxide and the phthalic groups is approx. 22:1. In a 16% dispersion in water, such as QCJ, the viscosities at 100°C are approx.

96 est (centistoke). The 2056-41 polymer is similar to a hard, light-brown wax, and in this the hydrophilic:hydrophobic ratio is approx. 16:1, and the viscosity is approx. 265 est. The 2056-34B polymer has the appearance of a hard, brown wax with a hydrophilic:hydrophobic ratio of approx. 10.9:1, and its viscosity under the same conditions as mentioned above is approx. 255 est. The higher the polymer's molecular weight, the lower the hydrophilic:hydrophobic molar ratio can be in this and still lead to a satisfactory soil release transport when using the present detergents. The QCJ and QCF polymers have melting points (as determined by differential thermal analysis)

of 50-60°C, a carboxyl analysis of 5-20 or 30 equivalents/10^ g and a pH of 6-8 in distilled water at a concentration of 5%. The molecular weights (weight average) lie within the range 20,000-25,000, and the molar ratio between ethylene terephthalate and polyoxyethylene terephthalate units is approx. 74:26. All the branded products mentioned are water-soluble in lukewarm or warm water (at 40-70°C) or they are at least easily dispersible and can be characterized by having a high molecular

weight, over 15,000, generally within the range 19,000-43,000, often preferably 20,000-25,000, e.g. about. 22000.

The enzymes used in some of the present detergents include both proteolytic and amylolytic enzymes, such as the alkaline proteases (subtilisin) and α-amylase. Among the preferred enzyme preparations that can be used are Alcalasé<®> 2.5L (2.5 Anson units per gram) and Termamyl 120L. However, other suitable proteolytic and amylolytic enzyme preparations can also be used. The aforementioned mixtures are available in liquid form and contain 5% active enzyme in combination with 65% propylene glycol and 30% water. The relative amounts referred to here apply to the active enzyme or active enzymes in the preparations.

The stabilizer or a mixture of stabilizers

for the enzyme most preferred is sodium formate or includes such a salt, but other water-soluble formates,

such as potassium formate, may also be used, and acetates may also be useful in the same way as other corresponding salts or mixtures of such salts and alkali metal formate.

The quaternary ammonium salt fabric softener used in some of the present liquid detergents can be any suitable such material which is stable in the present detergents. In some cases, known imidazolinium halides with satisfactory stability can be used instead of the usual quaternary ammonium halides. However, the quaternary ammonium halides are preferred. Such compounds will preferably be chlorides although bromides and iodides may be useful. Among the four substituents on the quaternary nitrogen atom, at least one, preferably two, will be a long-chain substituent, such as a higher linear alkyl group or fatty alkyl group, and more preferably two such substituents will be a higher fatty alkyl group. The chain length will usually be from 10 to 20, preferably 12 to 18, and most preferably 12-14, carbon atoms or mixtures thereof, such as coconut alkyl (derived from coconut oil or an equivalent raw material). The other substituents on the nitrogen atom will be lower alkyl, usually with 1-3 carbon atoms, and among these, methyl is the most preferred. Although other quaternary ammonium halides can also be used/at least when they only form part of the quaternary softener, the one that is most preferred and has the highest stability in the available liquid detergents is thus dicocosdimethylammonium chloride. Such a pro-

duct is available in the form of a liquid comprising 75%

active ingredient, 14% isopropanol and 11% water.

The aqueous medium used includes water and preferably also a lower alkanol. The water is preferably deionized water, but tap water with a hardness content of up to 300 ppm, calculated as calcium carbonate (the hardness is actually a mixture of magnesium and calcium ions), can be used although it is preferred that the hardness content is below 100 ppm to help in order to avoid any destabilization of the liquid detergent or a separation of parts thereof. Some water can be absorbed from the starting materials, such as aqueous soil loosening agents, enzyme preparations, softeners, alkanols or dyes. The lower alkanol can be any of ethanol, isopropanol or n-propanol, but ethanol is highly preferred. When ethanol is used, it will normally be used in the form of denatured alcohol, such as 3A, which includes a small proportion of water plus denaturant. Small amounts of compatible dissolved salts may also be present in the aqueous medium, but normally such will be avoided as far as possible.

Another liquid that can be used with advantage in some

of the available liquid detergents, such as those containing enzymes and fabric softeners, is a lower glycol,

as a glycol with 3-6 carbon atoms in its alkyl group. Although hexylene glycol can be used in some recipes, in some others it can promote instability, and propylene glycol is therefore preferred.

Various suitable auxiliary additives may be present in the present liquid detergents, such as fluorescent dyes, colorants (organic dyes and water-dispersible pigments, such as ultramarine blue), bactericides, fungicides or perfumes. The concentrations of such components will usually be kept low and are often less than 1% and preferably less than 0.7%. The perfume concentration will thus usually be below 1%, preferably 0.2-0.6%, e.g. 0.4%. Fluorescent whiteners or optical bleaching compounds may be present in the liquid detergent in a concentration of 0.02-2, preferably 0.1-1, and more preferably 0.2-0.5%. The indicated percentages apply to the marketed materials. Such whiteners are popular as cotton whiteners, bleach-soluble whiteners, polyamide whiteners or polyester whiteners, and mixtures thereof are generally used so that the detergent can be used for whitening a number of different materials that are washed, including cotton and synthetic materials. Examples of such good whitening agents are those designated as TA, DM, DMEA, DDEA, DMDDEA, BS, NTS, BBI, AC, DP, BBO, BOS and NTSA in a well-known article entitled Optical Brighteners and Their Evaluation by Per S. Stensby published in Soap and Chemical Specialties in April, May, July, August and September, 1967. Further discussion of the fluorescent bleaches can be found in an article entitled Optical Bleaches in the Soaps and Detergents by F.G. Villaume, in The.Journal of the American Oil Chemists' Society (October 1958), ol 35, No. 10, pp. 558-556. Useful fluorescent whitening agents are sold under the trade names Calcofluor White ALF, ALF-N, SOF A-2001, CWD, Phorwite RKH, CSL, powder, acid, FB 766, Blancophor PD, UNPA, Tinopa1(*3^ )RBS and RBS 200. The various whitening agents are normally present in the form of their water-soluble salts, but they can also be used in the corresponding acid forms. Most of such materials can be used for bleaching cotton and are of the stilbenesulphonic acid (or salt) or aminostilbene types which are here designated as stilbene whiteners, and a preferred one among such whiteners is Tinopar<*>^ 5BM Extra Conc. For the fabric softening detergent, the preferred content of bleaching agent will be 0.05-0.25, preferably 0.05-0.15, e.g. 0.1%. Dyes, such as Polar Brilliant Blue, will amount to 0.001-0.03, preferably 0.002-0.2, e.g. 0.0025 or 0.01, % if they are present. The various adjuvant materials will be selected based on their compatibility with the other recipe ingredients and because of their non-separating and non-settling properties. Because water-soluble, ionizable salts, regardless of whether these are inorganic or organic/ are generally incompatible with dirt-releasing agents, the presence of these will as a rule be avoided.

Among such salts which are preferably avoided are sodium sulfate, potassium sulfate, sodium chloride, potassium chloride, ammonium chloride or ammonium sulfate, but these are only examples of such salts. Although sodium formate should also be omitted from a number of liquid detergents, surprisingly a limited proportion of this has proven to be compatible with the other ingredients in the present recipe, in combination. The presence of ionizable materials, such as triethanolamine (TEA), diethanolamine, ethanolamine, diisopropanolamine, n-propanolamine or of the lower mono-, di-, tri- or mixed lower alkanolamines with 2-4 carbon atoms per alkanol group will be avoided because, in a similar way to the aforementioned salts, these destabilize the soil release promoting polymer and/or the liquid detergent. Among these, TEA appears to be the most destabilizing and causes severe separations of the polymer. In the present description, such ionizable materials which may form salts should be considered as part of the permissible proportions of any such salts which may be present. It will generally be desirable to avoid the presence of auxiliary additives other than dyes, perfumes, fluorescent whitening agents, anti-oxidation agents and any neutralizing agents that can be used to regulate the pH of the liquid detergent to within the stable range. It is preferred that any neutralizing agent used, usually to increase the pH of the liquid detergent, should be alkali metal hydroxide, such as sodium hydroxide, in an aqueous solution in a concentration of 5-40, e.g. 15-25, %. Triethanolamine salts and free triethanol-

amine should be especially avoided.

The liquid detergent produced will have a desired viscosity which is often within the range 50-500, preferably 100-200, centipoise, and the viscosity can be regulated by modifying the proportion of lower alkanol within the specified range. The liquid detergent will be easy to pour,

but will have a desired "fullness". Its pH will lie within the range 6-9, preferably 6.1-7.9, and often more preferably 6.5-7.5.

In the present soil-releasing-promoting liquid detergents according to the invention, which have improved stability during storage so that the soil-releasing-promoting polymer and the enzyme or enzymes do not deteriorate and do not separate from the rest of the mixture, the proportions of the various components will be as indicated below. All the different listed ingredients also include mixtures even if they are listed in the singular. The proportions of components stated below apply to the invention in general, respectively. the enzyme-containing product and the enzyme- and plasticizer-containing product.

The non-ionic surfactant (which includes mixtures thereof) or a mixture of non-ionic and anionic surfactants (both being of the synthetic organic type)

will be present within the range of 25-50% of the product, and they are preferably present in a proportion of 20-40% for the non-ionic surfactant and in a proportion of 3-15% for the anionic surfactant. The proportions of such surfactants will more preferably be respectively 25-35%: and 5-10%, e.g. respectively

about. 32% and approx. 7%. The dirt release promoting polymer will be present in, 1-5, preferably 2-5, and more preferably 2-3, e.g. about. 2.%. The lower alkanol content will be 3-15, preferably 5-12 and more preferably 6-10, e.g. about. 8,

%, and the water content will when a lower alkanol is present,

be 30-60, preferably 45-55, %, and if no lower alkanol is present, these areas will be increased to replace the lower alkanol with water. The content of ionizable, water-soluble salts, regardless of whether these are organic or inorganic, should be kept low and as a rule not above 1, preferably below 0.5, and more preferably below 0.3, % of,

the liquid detergent, and the triethanolamine content will be similarly limited in order to avoid separation of the dirt-releasing-promoting polymer, the desired limit values being

0.5, preferably 0.2, and most preferably 0.%. In some cases, the salt content will be kept at lower limits than the permissible alkanolamine content because some salts can be even more harmful to the stability of the product than alkanolamine. The content of the anionic surfactant present which can be considered as an ionizable salt will of course not be included in the limiting proportions of such a salt present because this does not seem to

have the same type of destabilizing effect on the present detergents. Although suitable auxiliaries may be present in the liquid detergent, such as the dye, perfume and fluorescent whitening agent mentioned above, the content of such auxiliaries will normally be kept to a minimum and will usually be below 2, preferably below 1, and more preferably below 0.8%, but the dye and whitener are not destabilizing.

For the enzyme-containing product (without softener), the content of synthetic, organic, non-ionic surfactant will normally lie within the range 25-40, preferably 28-36, and more preferably 30-34, e.g. 32.% of the product. The content of fatty alcohol alkoxylate sulfate will usually be 1-8, preferably 2-7, and more preferably 2-6, e.g. 3 or 5, %. the content of fluorescent whitening agent is within the range 0.02-2, preferably 0.1-1, e.g. 0.2 or 0.4, %. The percentage of active ingredient in the whitening agent can often be 0.01-1, which e.g. 0.01-0.1%. The content of the dirt release promoting polymer will be 1-5, preferably 1-3, and more preferably 1-2.5, e.g. about. 2.% (on the basis of active ingredient).

The total enzyme content will usually be 0.0005-0.15, preferably 0.025-0.1%, of which the protease content is 0.005-0.1% and the amylase content, if amylase is present, 0.005-0.05%. Preferred contents of the enzymes are respectively 0.01-0.1% and 0.01-0.03%. Even more preferably, the protease percentage is 0.02-0.05%. Specific recipe percentages are respectively about. 0.03% and 0.02%. The stabilizer for the enzymes, usually an alkali metal salt of a lower aliphatic acid with 1-3 carbon atoms, such as sodium formate, will usually be present in an amount of 0.2-2, preferably 0.5-1.5, and more preferably 0.7-1.3, e.g. 1.%. The content of lower alkanol will be 3-12, preferably 4-9, and more preferably 5-8, e.g. 5.5 or 7.5, %. The water content will be 40-65, preferably 46-62,

and more preferably 50-60, e.g. about. 54 or 55, %.

The content of ionizable, water-soluble salts, regardless of whether these are organic or inorganic, must be kept low and below 2%, and it usually does not exceed 1% of the liquid detergent, preferably below 0.5% and more preferably below 0.3 %, and the content of triethanolamine will be limited in a similar way to avoid separation of the dirt release promoting polymer, the desired limits being 0.5, preferably 0.2, and preferably 0%. In some cases, the salt content will be limited to lower amounts than the permitted alkanolamine content because certain salts can be even more harmful to the stability of the product than the alkanolamine. In the present detergents, however, the content of water-soluble alkali metal lower carboxylate, such as sodium formate, can be up to 2% because such components stabilize the enzymes and at such concentrations, especially at approx. 1% or less, are compatible with the detergent product and the soil release promoting polymer so that polymer separation does not occur.

For the enzymatic and softening liquid detergents, the content of synthetic, organic, non-ionic surfactant will

(which includes mixtures thereof) lie within the range 20-35, preferably 20-30, and more preferably 20-25, e.g.

22.% of the product. The content of the dirt release promoting polymer will be 1-5, preferably 1-2, and more preferably 1-1.5, e.g. about. 1% (based on active ingredient). The content of each compound will be 1-10, preferably 3-8, and more preferably 3-6, e.g. 4.5%. The enzyme content should be 0.005-0.15, preferably 0.025-0.05%, of which the protease content is 0.005-0.1% and the amylase content, if amylase is present, 0.005-0.05%. Preferred contents of the enzymes are respectively 0.01-0.05% and 0.01-0.025%. It is even more preferred that the protease content is 0.015-

0.04%. Specific recipe percentages are. respectively about. 0.023% °3 0.015%. The stabilizer, a lower aliphatic acid salt, such as sodium formate, for the enzymes will generally amount to 0.2-2, preferably 0.5-1.5, and more preferably 0.7-1.3, e.g. 1.%. The content of lower alkanol will be 1-10, preferably 1.5-3, and more preferably 2-2.5, e.g. 2 or 2.2, %. The content of lower glycol is 2-10, preferably 3-8, more preferably 4-7, e.g. 6.%. The water content will be 40-80, preferably 50-70, more preferably 60-65, e.g. about. 63.%.

The content of ionizable, water-soluble salts, regardless of whether these are organic or inorganic, must be kept low and as a rule does not amount to more than 1% of the liquid detergent, preferably below 0.5%, and more preferably below 0.3%, and the triethanolamine content will similarly be limited to avoid separation of the dirt release promoting polymer, the desired limits being 0.5%, preferably 0.2%, and most preferably 0%. In some cases, the salt content will be limited to a lower amount than the permitted alkanolamine content because certain salts can be even more harmful to the stability of the product than the alkanolamine.

In the present detergents, however, the content of water-soluble alkali metal lower carboxylate, such as sodium formate, can be up to 2% because such components stabilize the enzymes and at such concentrations, especially at approx. 1% or less is compatible with the detergent product.

The present liquid detergents may be prepared by mixing the various components thereof with the aqueous medium, preferably containing at least a portion of the lower alkanol, until they have been dissolved (or satisfactorily dispersed) therein, or the various components may be selectively dissolved in portions of the water and/or lower alkanol and/or lower glycol and/or liquid preparations of dirt-releasing polymer and/or liquid enzyme preparations, and then the different liquid fractions can be mixed with each other. It will often be preferable to regulate the liquid's pH to within the range 6.1-7.9, often more preferably 6.5-7.5, by adding a suitable neutralizing agent (not triethanolamine) which will not exert a destabilizing effect on the dirt-releasing polymer, the enzyme or enzymes, the softening agent or the liquid product containing these, so that these will not break down and will not separate from the liquid detergent during storage, especially at elevated temperatures. The preferred neutralizing agent is an aqueous solution of sodium hydroxide which will normally have a concentration of 10-40, preferably 15-25,% sodium hydroxide although weaker concentrations may occasionally be desirable. The product's viscosity can then be regulated by addition

of alkanol and/or water.

The present liquid detergent can be used

for washing (and treating) clothes containing synthetic fibres, such as polyester fibres, e.g. Dacron<®>, in the normal way used for washing with other liquid detergents. However, a smaller amount of the present product can be used due to its dirt release promoting effect, and in a number of cases the cleaning and softening effects obtained will be superior. Different concentrations of the liquid detergent can be used, and these are normally 0.02 or 0.04-0.3 or 0.6, preferably 0.05 or 0.1-0.15 or 0.3, %, the concentration generally corresponds to 1/2 cup per washing in a machine with a top setting for the product containing softener, and approx. 1/4 cup per washing for the other two types of products. It will generally be advised to use approx. 1/4 or 1/2 cup (approx. 60 or approx. 120 ml) of the liquid detergent per standard washing load (approx. 64 liters for a top load washing machine) which corresponds to a concentration of approx. 0.1% or approx. 0.2% of the liquid detergent in the wash water. Almost the same concentration can be used when the washing is carried out in a front-loading washing machine, even if the amount of water used is smaller (why less detergent is used). Normally, 3-3.5 kg of laundry will be put in the washing machine. The washing water temperature will preferably be at least 49°C, but good washing and good treatments using the dirt release promoting polymer, the enzymes and the softener in the liquid detergent can be achieved at temperatures

of 40-80, preferably 45-70,°C. The dry weight of the material that is washed and processed will usually be 5-15 or 20%

of the aqueous washing medium's weight, preferably 5-10% of this. The washing will be carried out with agitation for a period of from 5 minutes to 0.5 hour or 1 hour, often from 10

to 20 minutes. The washing materials are then rinsed, usually with several rinses, and dried, e.g. in an automatic clothes dryer. The first washing of the material to be treated will preferably be carried out when the material is not too dirty, so that the dirt release promoting polymer will be deposited on as clean a surface as possible. However, this is not necessary, and improvements in the cleaning of subsequently soiled materials and cloths will be observed when no special effort is made to perform the first washing with a cleaner substrate. Up to a limit, occasionally approx. 3 or 5 treatments, several washings with liquid detergent according to the invention will increase the dirt-releasing properties of the treated material.

When polyester and polyester/cotton blend fabrics are washed in the described manner with the detergents according to the invention and then become soiled or stained with used motor oil and washed with a detergent according to the invention or another commercial detergent (often of the constructed type),

a significant removal of the lipophilic soil can be noted compared to similar treatments where the liquid detergent used initially did not contain any soil release promoting polymer. In other comparisons, when significant proportions of a water-soluble, ionizable salt, such as 5% sodium sulfate, or over 1% triethanolamide or a salt thereof are present in the liquid detergent, it will appear that after storage at elevated temperature (43°C) in 2 weeks, which simulates a longer period of storage at room temperature, phases will separate from the bulk of the liquid detergent, and the dirt-releasing properties of the polymer contained therein will be reduced,

in the same way as the enzymatic and softening effects when such materials occur in the recipe. When the enzyme stabilizer is omitted, the enzymatic effect is significantly reduced during storage. The detergents according to the invention are

therefore of importance because they are stable, lead to more effective products for the intended purposes, dirt release improvement, cleaning effects and softening of the washed laundry,

and they are also a more appealing liquid detergent that does not separate on storage.

In the examples below, the present invention is described in more detail. Unless otherwise stated,

all parts are by weight and all temperatures are in °C.

Example 1

The liquid detergent according to the recipe is made by mixing a portion of the water with the non-ionic and anionic surfactants, followed by the addition of the soil release promoting polymer, the ethanol, the fluorescent bleach, the dye and any remaining water. Then an acid or base (NaOH is preferred) can be used if desired to regulate the pH to within the desired range.

In the above example, the pH is 7.8 (undiluted). However, when the pH is lower than desired, an aqueous solution of sodium hydroxide (20%) is used to increase this to the desired level, e.g. 7.5, and the amount used is small, e.g. about. 0.2% NaOH or less. The prescribed amount of perfume is then added. The manufactured product is tested by storage at 4 3.3°C for 2 weeks, after which it is observed that it exists in the form of a single phase and is essentially the same as the first manufactured product.

Shortly after the liquid detergent has been made, it is used to wash a test load of clean laundry, including some polyester material and other materials of 65% polyester and 35% cotton. The concentration of the liquid detergent during washing is 0.1% by weight, based on the weight of the washing water, and the cloths being washed amount to approx.

5% by weight of the wash water. After washing in a standard test washing machine using the standard conditions previously described has been completed, the cloths are rinsed and dried. Each sample cloth is then stained with approx. 3 drops of used motor oil of a standard type used for such a test, and washed in the same type of machine using a commercial detergent. Cloths that have not been previously treated with the present liquid detergent are used as blank samples. The wash-treatment and subsequent wash temperatures are the same in all cases and are 49°C, which is considered an optimal temperature for the treatment. In some trials, the subsequent washing is carried out with the liquid detergent according to the invention. In all tests, the treated cloths are significantly whiter to look at and when tested with a reflection apparatus than the blank test cloths, and this shows that the soil-release-promoting component in the liquid detergent effectively helped to remove such applied soil from the cloths during subsequent washes . It should also be noted that the re-deposition of the removed (from the stain application) used motor oil on unsoiled parts of the laundry is reduced when the soil-releasing polymer is applied to the laundry before the test soiling thereof. The liquid detergent which contains a dirt release-promoting polymer thus, in addition to contributing to the removal of the dirt, also helps to keep the dirt suspended and inhibits the deposition of such removed dirt on other parts of the sample material.

When 2% or 3% triethanolamine is present in the liquid detergent with the above recipe,

as a replacement for part of the detergent's water content, after 2 weeks of storage at 43.3°C it was found that the detergent has separated. A separation also takes place under such conditions when the triethanolamine is absent and 5% sodium sulfate is present according to the recipe. When the triethanolamine is present, the dirt release promoting effect of the liquid detergent is also significantly reduced compared to the test recipe according to the invention,

after 2 weeks of aging at an elevated temperature of 43.3°C, followed by testing in the manner described above. In addition, storage at room temperature also leads to such a reduction in the dirt release-promoting activity of a detergent containing triethanolamine compared to the detergent according to the trial recipe.

When the amount of soil release promoting polymer is reduced to 1% or increased to 3%, the same results as those reported above are obtained, with the changes that the recipe with 3% release polymer is more effective than the recipe with 2% in terms of promoting soil release at the described tests, and the recipe with 1% is somewhat less effective, although good and excellent results are obtained with

1% and 3% concentrations.

When similar tests are carried out using other lipophilic soils, such as corn oil (red), butter, shoe polish, lip stick, salad dressing and barbecue sauce, similar results are obtained, with the strongest improvements achieved with the test detergents according to the blank test detergent being corn oil, lip stick and used or dirty motor oil . The release is 100% for the corn oil, butter, salad dressing and barbecue sauce stains and is almost 100% for lipstick. Similar results are obtained when the test textile is made up of single-knit Dacron, double-knit Dacron<®> and DacrorP^/cotton blends, and they are also obtained at treatment temperatures above 32°C. Such results are also obtained when a commercial or household washing machine of the top loading or side loading type is used instead of the laboratory test washing machine•

Example 2

In the main recipe according to example 1, the sodium linear dodecylbenzenesulfonate is replaced by the corresponding tridecylbenzenesulfonate in one case and with 'Neodol 25-3-S"

Which is the sodium salt of a sulfated condensation product

of approx. 3 molecules of ethylene oxide and a higher fatty alcohol with an average of 12-15 carbon atoms per molecule in another case, and the non-ionic surfactant is replaced by "Neodol 25-7" in both cases. When the detergents obtained are tested to determine their stability at elevated temperature and their storage stability, as described in example 1, similar good results are obtained. When more than 0.5% triethanolamide is present in the detergents instead of a corresponding proportion of water and/or when 2% sodium sulfate or another water-soluble, ionizable salt is present, separation of the components in the liquid detergent takes place in a similar way. When the liquid detergents according to this example are used for washing polyester laundry of the types discussed in example 1, after which the laundry is soiled and then washed, improved removals of lipophilic dirt are obtained compared to blank samples which do not contain a soil release promoting polymer of the type used according to to the recipes according to this example. When, in addition, more than 0.5% triethanolamine and/or 2% water-soluble, ionizable salt, such as sodium sulfate, is present in each of the recipes, after aging at elevated temperature or room temperature for periods of 2 weeks and 3 months the dirt-releasing effect of the detergent still decreases significantly if the separated detergent is shaken to disperse the different components,

in this and then used in the manner described above, compared to the experimental recipes which contain neither triethanolamine nor such a salt.

Example 3

The first recipe according to the invention which

is stated in example 1, is changed by replacing the anionic surfactant in this with "Neodol 25-7", so that the product contains 39% non-ionic surfactant, and by replacing the ethanol with deionized water. The product does not separate during storage and has dirt-releasing properties similar to those that the products according to the invention according to examples 1 and 2 have. Moreover, the test product is stable under accelerated aging when stored at elevated temperature and over extended periods when stored at room temperature, while a comparative product containing 1% triethanolamine and/or 2% sodium sulfate separates. Similarly, such comparative products do not assist in releasing deposited lipophilic dirt to the extent that can be achieved with the trial products of this example.

Example 4

When the contents of the different trial recipes according to the invention as stated in examples 1-3 are varied by -10% and -25%, while the relative amounts of the different materials are kept within the ranges indicated in the description, and when in such recipes 2% QCF ( Alkaril Chemicals CAS 9016-88-0) and 12.3% water are used instead of the QCJ dirt-release polymer (aqueous solution), since the QCF used is first dissolved in water, good dirt-release promoting results are obtained similar to those described in examples 1 -3, and the products are stable and do not separate during storage. This is also the case if the fluorescent dye, the dye and the perfume are omitted from the recipes according to this example. When triethanolamine or an ionizable salt is present in such recipes beyond the stated limits, the product similarly becomes less stable and less effective in promoting the release of dirt during washing.

According to other variations of this example, the non-ionic surfactant is a mixture of equal parts "Neodol 25-7" and "Neodol 91-6", and the anionic surfactant is "Neodol 45-2,25-S". Results similar to those previously reported in Examples 1-3 can be obtained in both test washing machines and in actual washing of clothes using commercial or domestic top load or side load washing machines. This is also the case when pH adjustments are made with potassium hydroxide and when such adjustments are made with sodium hydroxide or potassium hydroxide to pH values of 7.0, 6.6 and 7.4. Normally, such pH adjustments will require less than 1% sodium hydroxide solution, preferably less than 0.5% thereof, and more preferably less than 0.2% thereof. In some cases, the sodium hydroxide can be added as a recipe ingredient in the stated proportional amount in a known way to achieve the desired pH regulation (based on previous experience with the recipe), but it would still be preferable to add this before the perfume even if this is not is necessary. Although a 20% sodium hydroxide solution concentration can often be preferable, other concentrations of this can also be used in a similar way.

Example 5

average 14-15 carbon atoms and 2.25 molecules of ethylene oxide 3. Proteolytic enzyme (5% enzyme active ingredient, 65% propylene glycol and 30% water) 4. Amylolytic enzyme (5% enzyme active ingredient, 65% propylene glycol and 30% water)

5. A fluorescent whitening agent of the stilbene type

The liquid detergent according to the recipe is prepared in a similar way as according to example 1 by mixing a portion of the water with the anionic and non-ionic surfactants, followed by the addition of the soil release-promoting polymer, ethanol, the fluorescent whitening agent (of and to dissolved in ethanol or in ethanol-water solutions), enzymes, sodium formate (dissolved in a little water), dye and any remaining water. Then, if desired, an acid or base (NaOH is preferred) can be used to regulate the pH to within the desired range, e.g. 7. When the pH is lower than desired, an aqueous solution of sodium hydroxide (20%) is used to increase this to the desired level. The amount used is small, e.g. about. 0-.2% NaOH or less. The proportion of perfume determined according to the recipe is then added. The manufactured product is tested by storage at 43.3°C for one week, after which it can be visually determined that it is a clear, light blue liquid in a stable, single phase essentially similar to the state it had when it was manufactured. The protease activity is better than that of a liquid detergent blank containing 7% sodium dodecylbenzene sulfonate, 2.8% triethanolamine (TEA) and no alcohol ether sulfate, and it is far better than in other detergents similar to the blank test detergent, but containing no sodium formate in one case and no TEA in a other case. When both the formate and TEA are omitted from the blank test recipe (in all cases the differences are compensated with water), both the protease activity and the amylase activity are greatly reduced. The blank and the first two varied products are unstable on storage, and the polymer settles to the bottom.

Shortly after the liquid detergent has been produced, it is used to wash a sample load of clean laundry, including a portion of polyester materials and others of a material of 65% polyester and 35% cotton. The washing conditions are the same as according to Example 1, and the results are very similar, except that additional ezymatic cleansing action is obtained. Such desired activities are obtained despite the presence of the sodium formate and any other salt or any other salts in the liquid.

When 2.8% triethanolamine or TEA salt is present in the liquid detergent according to the previously stated recipe to replace part of the water content of the liquid detergent, it is found that the detergent has separated after storage for one week at 43.3 °C. Separation also occurs under such conditions when the triethanolamine is not present and 5% sodium sulfate is present according to the recipe. Storage at room temperature also leads to such a separation and a corresponding reduction of the dirt release-promoting activity for detergents containing the specified relative amounts of triethanolamine and/or sodium sulfate, compared to the test recipe.

Testing the liquid detergent to determine its enzymatic cleaning power gives satisfactory results,

and this suggests that the proteolytic and amylolytic enzymes work effectively in the stable liquid detergent. This is the case despite the fact that enzymes are often unstable in liquid detergent tanks, especially at elevated temperatures.

Example 6

According to a variant of the recipe according to example 5, when the proportion of "Neodol 45-2.25 S" is increased to 5%, the proportion of ethanol is increased to 7.5%, 0.01% "Polar Brilliant Blue" dye is used instead . The liquid detergent is clear blue and can in the absence of dye

have a light color so that it can also be dyed in the desired way

when using other dyes. Instead of the aforementioned whitening agent system, correspondingly proportional amounts of Tinopal<®> RBS-200, Tinopal<®>4226 or Phorwite RKH or mixtures thereof can be used. In all such cases, the adhesion of the fluorescent whitening agent is improved due to the presence of the higher fatty alcohol ethoxylate sulfate, and unlike other anionic surfactants,

like sodium linear dodecylbenzene sulfonate, the fatty alcohol ethoxylate sulfate does not destabilize the polymeric soil release agent in the presence of enzyme and enzyme stabilizer. _- .

Example 7

The recipe according to example 5 is changed so that 5% "Neodol 25-3 S" is present instead of the 3% "Neodol 45-2.25 S". The prepared product is stable and clear after storage at elevated temperature, and the Alcalase(*R*) and "Termamyl" stabilities are equal to the stabilities of the main blank mentioned in Example 1. However, when 2.8% TEA is also present according to to the recipes, the product is unstable as the QCJ soil release polymer flocculates after one week of storage at 43°C.

Example 8

The content of the different experimental recipes according to the invention as indicated in examples 5-7 is varied by -10% and -25% while the relative amounts of the different materials are kept within the previously indicated ranges. According to such recipes, instead of the QCJ dirt release polymer (aqueous solution) 2% QCF and 11.4% water are used, the QCF used being first dissolved in the water. Other enzymes, stabilisers, alcohols and degreasers, as described above, can also be used in the indicated relative amounts. The detergents obtained are clear, stable and do not separate and exhibit good dirt release promoting properties, cleaning properties and whitening properties similar to those described in examples 5-7. This is also the case when the fluorescent dye, colorant and perfume are omitted from the recipes according to this example. When triethanolamine or an ionizable salt is present in such mixtures beyond the stated limits and when other anionic surfactants, such as sodium higher alkylbenzene sulfonates, are used instead of the alcohol ethoxylate sulfate, the product similarly becomes less stable and less effective in promoting soil release under washing, and when the sodium formate is discarded, the activity of the enzyme is lost after only a few days of storage at the elevated test temperature.

According to other variations of this example, the non-ionic surfactant is constituted by "Neodol 23-6.5" or by a mixture of equal parts of "Neodol 23-6.5" and "Neodol 25-7", the same relative amounts is used, and a stable, effective product is obtained. The alcohol ethoxylate sulfate can also be made up of an equal mixture of "Neodol 25-3 S" and "Neodol 45-2.25 S", and good results are obtained. With such variations, results similar to those previously reported in examples 5-7 can be achieved in test washing machines as well as household washing machines and commercial washing machines either of the type with top loading or with side loading. This is also the case when the pH adjustment is made with sodium hydroxy and when such adjustments are made with sodium hydroxide or potassium hydroxide to pH values of 6.6, 7.4, 7.9 and 8.6. Normally, less than 1, preferably less than 0.5, and more preferably less than 0.2% sodium hydroxide solution will be used for such pH adjustments. In some cases, the sodium hydroxide can be added as a component according to the recipe in the relative amount that is known to provide the desired pH regulation (based on previous experience with the recipe), but it will still be preferred to add this before the perfume even if this is not is necessary. Although a sodium hydroxide solution with a concn

of 20% can often be preferable, other concentrations of sodium hydroxide can also be used in a similar way.

It appears from examples 5-8 and the above description that the present invention provides a stable and appealing liquid detergent containing various components which could be expected to adversely affect the stability of the final product. Nevertheless, a stable product according to the invention is surprisingly obtained. Such a product has desired dirt-releasing, dirt-splitting, fluorescent whitening (when a whitening agent is present) and cleaning properties. Several of the components in the present detergents have a double effect in them. For example, the alcohol ethoxylate sulfate improves the washing power and helps to make the substrates (clothing fibers) more adhesion-friendly so that the fluorescent whiteners will be more effective. The sodium formate which is a stabilizer for enzymes does not destabilize the soil release agent which would otherwise be expected.

The various components in these liquid detergents work together so that a surprisingly appealing, stable and effective detergent is obtained. It thus appears that the available detergents represent an unpredictable technical advance when it comes to producing stable products that are preferably attractively clear (transparent or <g>translucent), although in some cases translucent and semi-clear or intentionally cream-like products can be made.

6. Di-cocodimethylammonium chloride (contains 75% active ingredient, 14% isopropanol and 11% water)

The liquid detergent according to the above recipe is made in a manner which is substantially similar to that used in examples 5-8, but where the fabric softener is included and the anionic surfactant is omitted. The manufactured product is tested by storage for one week at 43.3°C,

and it could then be observed that it consisted of a clear, pale blue liquid with a stable, single phase essentially similar to the state in which it was prepared. The protease activity is 70% of the activity when the liquid detergent was made, and the amylase activity is 85% of the original value.

Shortly after the liquid detergent had been prepared, it was used to wash a test load of clean laundry, including some of polyester materials and others of a material of 65% polyester and 35% cotton. The detergent concentration and the other conditions for this washing are the same as according to example 1, and the results are also essentially the same, except that according to this example an improved fabric softening was achieved. When 2% or 3% triethanolamine or TEA salt is present in the liquid detergent with the above recipe,

instead of part of the water content in this, it turned out

that the detergent had separated after two weeks of storage at 43.3°C. Separation also occurs under such conditions when the triethanolamine is not present and 5% sodium sulfate is present according to the recipe. Furthermore, when the triethanolamine is present, the liquid detergent's dirt-releasing effect is significantly reduced. Storage at room temperature also leads to such a reduction of the dirt release-promoting activity for detergents containing the specified relative amounts of triethanolamine and/or sodium sulfate, compared to the detergent according to the test recipe. When the amount of soil release promoting polymer is increased to 2%, the same types of results as stated above are obtained.

Tests with the liquid detergent to determine its fabric softening ability and enzymatic cleaning power give satisfactory results, and this suggests that the quaternary ammonium halide and the proteolytic and amylolytic enzymes function effectively in the stable liquid detergent. This is the case despite the fact that enzymes and quaternary ammonium halides are also unstable in liquid detergent tanks, especially at elevated temperatures.

However, a replacement of propylene glycol with higher glycols, such as glycols with 8-12 carbon atoms, will cause the product to separate into two phases. According to the particular formulation, a complete replacement of propylene glycol with ethylene glycol will also cause phase separation although hexylene glycol and amylene glycol are considered useful glycol constituents in the present type of liquid detergent if used in smaller relative amounts and if used in conjunction with lower glycols , such as propylene glycol. If the dicocosdimethylammonium chloride is replaced by dihydrogenated-tallow-dimethylammonium chloride, in a similar way the liquid detergent will also separate into two phases, especially in the presence of hexylene glycol (as a substitute for propylene glycol). In some cases, however, the dehydrogenated-tai<g->dimethylammonium chloride can again be used in a stable product by reducing the amount of this present and by mixing with dicocosdimethylammonium chloride or other di-higher-alkyl-di-lower-alkyl-quaternary- ammonium halides in which the higher alkyl groups have 12-14 carbon atoms and the lower alkyl groups 1 or 2 carbon atoms.

As an alternative, a more hydrophilic, quaternary ammonium halide, such as tallow-dimethylammonium chloride, which exhibits a stronger unsaturation and is thus more tolerant of electrolytes, can be used with good results.

Example 10

When in the main recipe according to example 9 the non-ionic surfactant is replaced by "Neodol 23-6.5", 0.01% "Polar Brilliant Blue" dye is used instead of 0.0025%, and

a fluorescent stilbene bleach is present, e.g. Tinopal<®> RBS-200, Tinopal<®> 5BM or Tinopal<®> 4226 or Phorwite RKH or Phorwite BBP, in an amount of 0.1%, is available

a stable and effective product which acts in a similar way to the product according to example 9, but which has a stronger whitening power due to the presence of the whitening agent which is stable in the product. The product according to this example also has an attractive clear appearance and is stable during storage.

Example 11

The contents of the experimental recipes according to examples 9 and 10 are varied by ^10% and -25% while the relative amounts of the different materials are kept within the ranges indicated in the present description. In such recipes, instead of the QCJ dirt release polymer (aqueous solution), 1% QCF and 5.7% water are used, the QCF being first dissolved in the water. In addition, other enzymes, stabilizers, fabric softeners, glycols, alcohols and dyes, as described in the present description, can be used within the specified amount ranges. The detergents obtained are clear, stable and do not separate and exhibit good soil release promoting, softening, cleaning and whitening properties, similar to those described in examples 9 and 10. This is also the case when the fluorescent dye, the dye and the perfume is omitted from the recipes according to this example. When triethanolamine or an ionizable salt is present in such recipes beyond the stated limits, the product similarly becomes less stable and less effective in promoting soil release during washing, and when the sodium formate and glycol are omitted, the effects of the enzyme are lost after only a few days storage at the elevated test temperature.

According to other variants of this example, the non-ionic surfactant is made up of a mixture of equal parts "Neodol 23-6.5" and "Neodol 25-7", using the same total relative amount. Results similar to those reported above in Examples 9 and 10 are obtained in test washing machines as well as household washing machines and commercial washing machines of the top-loading or side-loading type. This is also the case when pH adjustments are made with potassium hydroxide and when such adjustments are made with sodium hydroxide or potassium hydroxide to pH values of 6.6, 7.4, 7.9 and 8.6.

From examples 9-11 and the preceding examples as well

as from the present description it is clear that the present invention provides a stable and appealing liquid detergent despite the fact that it contains various components which it was to be expected would have adversely affected the stability of the final product. Nevertheless, surprisingly, a stable product is obtained which has the desired dirt-releasing, fabric-softening, dirt-splitting and cleaning properties. Several of the components in the present detergents have dual effects in them.

For example, the propylene glycol can help to solubilize the lipophilic materials of the recipe while helping to stabilize the enzymes. The sodium formate is a stabilizer for enzymes, does not destabilize the soil release agent, which would otherwise be expected. Although some quaternary ammonium halides and some glycols can destabilize liquid detergents similar to the detergents according to the invention, the present materials do not do this. This is surprising because hydrophobic, quaternary ammonium halides, which normally flocculate from solution under the influence of electrolytes, are stable in the present liquid detergents. It thus appears that the available detergents represent an unpredictable technical advance in terms of producing stable liquid detergents.

Claims (3)

1. Soil-release promoting, stable, aqueous, liquid detergent containing 20-50% by weight of a non-ionic surfactant or a mixture of non-ionic and anionic surfactants, 1-5% by weight of a soil-release-promoting polymer of polyethylene terephthalate and polyoxyethylene terephthalate with a total molecular weight of 15,000-50,000, the molar ratio between polyethylene terephthalate units and polyoxyethylene terephthalate units in the polymer being within the range 2:1-6:1 and the polyoxyethylene terephthalate having a molecular weight within the range 1000-10,000, and an aqueous medium in which the pH is 6-9, characterized in that it contains no more than 2% by weight of a water-soluble, ionizable salt that is not an anionic, surface-active, water-soluble salt. 2. Detergent according to claim 1, characterized in that it contains no more than 0.3% by weight of a water-soluble, ionizable salt that is not an anionic, surface-active, water-soluble salt. 3. Detergent according to claim 1 or 2, characterized in that the water-soluble, ionizable salt which is not an anionic, surface-active, water-soluble salt, is sodium formate.