DE69203473T2 - Detergent compositions. - Google Patents

Description

Technical area

The present invention relates to detergents, in particular to detergents used for washing textiles, dishes and surfaces in the home. The detergents according to the invention, which are particularly, but not exclusively, suitable for washing textiles, contain one or more glycolipid biosurfactants.

Background and state of the art

Detergents typically contain one or more detergent active agents in addition to various other ingredients such as detergent builders, bleaches, fluorescent agents, perfumes, etc. Specific applications of detergents include textile cleaning, usually by washing wearable textiles in the tub or washing machine, cleaning earthenware and cooking vessels, also by washing in the tub (manual dishwashing) and cleaning hard surfaces such as glass, glazed surfaces, plastics, metals and enamel.

Numerous classes of surfactants have been used as detergent actives, some for many years, including anionics and nonionics.

Surfactants containing a saccharide moiety linked to a hydrocarbon chain have been described in the art. For example, WO-A-90 09451 (Novo Nordisk) discloses fatty acid esters of methyl glycosides suitable as surfactants. WO-A-91 00331 (Unilever) and EP-A-423 969 (Unilever) describe O-alkanoyl derivatives of reducing hexose sugars, for example O-alkanoyl glucoside, and their use as detergent surfactants.

The present invention relates to glycolipid biosurfactants and in particular to rhamnolipids and sophorose lipids, glucose lipids, cellobiose lipids and trehalose lipids. These glycolipid biosurfactants are derived from biological fermentation processes (either bacterial or yeast fermentation). This is inherently progressive in that fermentation products can generally be derived from renewable feedstocks and are most likely to be biodegradable after use.

We have now found that these glycolipid biosurfactants provide a synergistic enhancement of oil/grease soil washing performance when used in certain combinations with each other or combined with other surfactant(s). Enhanced washing performance has also been observed with glycolipids that have poor washing performance when used individually.

JP-A-63 077 535 (Toyo Beauty) discloses an emulsion composition containing rhamnolipid or its salt bound with α-decenoic acid as an emulsifier. The emulsion is said to be suitable for cosmetics, care products, pharmaceuticals, toiletries, detergents and foods.

DE-A-35 26 417 (Wella AG) describes cosmetic agents containing sophorose lipid lactone. They are particularly suitable for combating dandruff and as a bacteriostatic agent, for example in deodorants. The agents disclosed include a shampoo, a bubble bath and a shower gel containing a high proportion of highly foaming anionic surfactants (30 to 40% by weight) (alkyl ether sulfate and acyl glutamate) and also small amounts of sophorose lipid lactone (2 to 3% by weight) to provide antibacterial and skin care properties.

US-A-4 216 311 (Kao) discloses the preparation of a glycolipid methyl ester from sophorose lipid. These glycolipid methyl esters are waxy, hydrophilic surface-active materials useful, for example, as emulsifiers, wetting agents, and oil and fat improvers. JP-A-63 063389 (Kao) relates to a biological preparation of a similar disaccharide glycolipid intended for similar uses.

JP-A-62 091 236 (Nippon Oils and Fats) describes a succinic trehalose lipid consisting of a succinic acid residue bound to a fatty acid residue. The lipid is used as an emulsion stabilizer.

Definition of the invention

The present invention provides a detergent composition comprising 1 to 60% by weight in total of:

(i) a first surfactant which is a micellar phase surfactant (as defined below) which is a glycolipid biosurfactant selected from sophorose lipids, rhamnolipids, glucose lipids, cellobiose lipids and mixtures thereof, and

(ii) a second surfactant which is a lamellar phase surfactant (as defined below) which is a glycolipid biosurfactant selected from rhamnolipids, glucose lipids, trehalose lipids and mixtures thereof or a non-glycolipid surfactant,

and optionally 5 to 80% by weight of a detergency builder, wherein the composition contains more than 5% by weight glycolipid biosurfactant.

The invention also provides a method for washing which comprises bringing textiles or an inanimate surface to be cleaned into contact with an agent according to the preceding paragraph or with a washing solution obtainable by adding the agent to water, in particular in amounts in the range of 0.5 to 50 grams of the agent per liter of water.

Description of the invention in detail

The detergent according to the invention contains at least two different surfactants with different properties, at least one of which must be a glycolipid biosurfactant.

The two classes of surfactants are referred to herein as micellar phase surfactants and lamellar phase surfactants, respectively. These terms refer to the phase in which the surfactants are likely to exist under typical washing conditions.

The two types of surfactants can be determined by the behavior of a 1% by weight aqueous solution in demineralized Water at pH 7.0 and 25ºC. A surfactant solution with dispersed lamellar phases shows birefringent textures when observed under a polarizing optical microscope, while a micellar solution does not.

A surfactant with micellar phase generally gives a clear solution when present at a concentration of 1% by weight in demineralized water at pH 7.0 and 25ºC, although the presence of small amounts of impurities may reduce clarity. A surfactant with lamellar phase always gives a cloudy solution when present at a concentration of 1% by weight in demineralized water at pH 7.0 and 2500

At least the micellar phase surfactant must be selected from the specific class of surfactants, the glycolipid biosurfactants, while the lamellar phase surfactant may or may not be a glycolipid biosurfactant. Thus, some glycolipids are micellar phase surfactants and the others are lamellar phase surfactants.

Glycolipid surfactants with which the present invention is concerned are rhamnolipids, glucose lipids, sophorose lipids, trehalose lipids, cellobiose lipids and mixtures thereof. Within any glycolipid class, some may be micellar and others may be lamellar.

Micellar phase glycolipid biosurfactants can be suitably selected from rhamnolipids, glucose lipids, sophorose lipids, cellobiose lipids and mixtures thereof.

Lamellar phase glycolipid biosurfactants can be suitably selected from rhamnolipids, glucose lipids, trehalose lipids and mixtures thereof.

Surfactants (i) and (ii) can both be glycolipids. The micellar phase glycolipid is then most preferably a rhamnolipid, a sophorose lipid or a cellobiose lipid, while the lamellar phase glycolipid is most preferably a trehalose lipid, a glucose lipid or a rhamnolipid.

Alternatively, the lamellar phase surfactant (ii) may be a non-glycolipid surfactant, preferably an anionic or non-ionic surfactant. Zwitterionic and cationic surfactants are not preferred and if present, it is desirable that they be present in small amounts, such as not more than 10% by weight of the total surfactant present.

Preferred anionic and nonionic surfactants are listed below.

The weight ratio of the first surfactant (i) to the second surfactant (ii) is preferably in the range from 20:1 to 1:20 and may be in the narrower range, for example from 10:1 to 1:10, more preferably 4:1 to 1:4.

The glycolipid biosurfactant

Specific biosurfactants include rhamnolipids, glucoselipids, sophoroselipids, trehaloselipids, cellobioselipids and mixtures thereof. Each is described in more detail below:

Rhamnolipids

These biosurfactants have the formula (I):

wherein a is 1 or 2, b is 1 or 2, n is 4 to 10, preferably 6; R¹ is H or a cation, preferably H, or a monovalent solubilizing cation, R² is H or the group

CH₃(CH₂)mCH = CH- -

means, preferably H; m means 4 to 10 and the values of m and n, if they occur, do not need to be equal.

Rhamnolipids can be produced by bacterial fermentation. They are advantageous in themselves because products from bacterial fermentation can generally be derived from renewable raw materials and are likely to be biodegradable after use. A further advantage of the surfactants of formula (I) is that they are obtained as by-products in enzyme production.

Rhamnolipids can be produced by bacteria of the genus Pseudomonas. Bacterial fermentation typically uses as substrates a sugar or glycerol or an alkane or mixtures thereof.

Suitable fermentation processes are described as an overview by D. Haferburg, R. Hommel, R. Claus and H.P. Kleber in Adv. Biochem. Eng./Biotechnol. (1986) 33, 53 to 90 and by F. Wagner, H. Bock and A. Kretschmar in Fermentation (editor R.M. Lafferty) (1981), 181 to 192, Springer Verlag, Vienna.

A rhamnolipid sample will generally contain a variety of individual compounds within the general formula (I). The ratios of individual compounds are determined by the microorganism species and the particular strain used for fermentation, the substrate materials supplied for fermentation and other fermentation conditions.

Bacterial fermentation generally produces compounds where R¹ is hydrogen or a solubilizing cation. Such compounds can undergo conversion between salt and acid form in aqueous solution, according to the pH of the solution. Common solubilizing cations are alkali metal, ammonium and alkanolamine.

Glucose lipids

A second class of glycolipid biosurfactants according to the present invention comprises glucose lipids of the formula (II)

wherein R¹ is H or a cation, p is 1 to 4 and q is 4 to 10, preferably 6.

Glucose lipids can be produced by the bacterium Alcaligenes Sp.MM1. Suitable fermentation processes are reviewed by M. Schmidt in his dissertation (1990) Technical University of Braunschweig and by Schulz et al. (1991) Z. Naturforsch. 46C, 197 to 203. The glucose lipids are obtained from the fermentation broth via solvent extraction using ethyl ether or a mixture of either dichloromethane:methanol or chloroform:methanol.

Sophoroselipids

A third class of glycolipid biosurfactant according to the present invention comprises sophorose lipids of the formula (III)

wherein R³ and R⁴ individually represent H or an acetyl group, R⁵ represents a saturated or unsaturated, hydroxylated or non-hydroxylated hydrocarbon group having 1 to 9 carbon atoms, preferably a methyl group, R⁶ represents a saturated or unsaturated, hydroxylated or non-hydroxylated hydrocarbon group having 1 to 19 carbon atoms, with the proviso that the total number of carbon atoms in the groups R⁵ and R⁴ does not exceed 20 and is preferably 14 to 18.

The sophorose lipid can be added to a detergent composition according to the invention either in the open chain acid form, wherein R⁷ is H and R⁸ is OH, or in its lactone form, wherein a lactone ring is formed between R⁷ and R⁸ as shown in formula (IV).

wherein R³, R⁴ and R⁶ are as defined above, with the proviso that at least one of R³ and R⁴ is an acetyl group.

Sophorose lipids can be produced by yeast cells, for example Torulopsis apicola and Torulopsis bombicola. The fermentation process typically uses sugars and alkanes as substrates. Suitable fermentation processes are reviewed in AP Tulloch, JFT Spencer and PAJ Gorin, Can. J. Chem. (1962) 40, 1326 and U. Gobbert, S. Lang and F. Wagner, Biotechnology Letters (1984) 6 (4), 225. The product obtained is a mixture of various open-chain sophorose lipids and sophorose lipid lactones, which can be used as mixtures or the required form can be isolated. When the glycolipid biosurfactant comprises sophorose lipids, the weight ratio of sophorose lipids to additional surfactant is preferably in the range of 4:1 to 3:2, more preferably 4:1. Trehalose Lipids A fourth class of glycolipid biosurfactant according to the present invention comprises trehalose lipids of the general formula (V)

wherein R⁹, R¹⁰ and R¹¹ each individually represent a saturated or unsaturated, hydroxylated or non-hydroxylated hydrocarbon having 5 to 13 carbon atoms.

Trehalose lipids can be produced by bacterial fermentation using the marine bacterium Arthrobacter sp. Ek 1 or the freshwater bacterium Rhodococcus erythropolis. Suitable fermentation procedures have been provided by Ishigami et al. (1987) J. Jpn Oil Chem Soc 36 847 to 851, Schultz et al. (1991) , Z. Naturforsch. 46C 197 to 203 and Passeri et al. (1991) Z. Naturforsch. 46C 204 to 209.

Cellobioselipids

A fifth class of glycolipid biosurfactants according to the present invention comprises cellobiose lipids of the general formula (VI),

wherein R¹ represents H or a cation, R¹² represents a saturated or unsaturated, hydroxylated or non-hydroxylated hydrocarbon having 9 to 15 carbon atoms, preferably 13 carbon atoms, R¹³ represents H or an acetyl group, R¹⁴ represents a saturated or unsaturated, hydroxylated or non-hydroxylated hydrocarbon having 4 to 16 carbon atoms.

Cellobiose lipids can be produced by fungal cells of the genus Ustilago. Suitable fermentation procedures are provided by Frautz, Lang and Wagner (1986) Biotech Letts 8 757 to 762.

When the glycolipid biosurfactant comprises cellobiose lipids, the weight ratio of cellobiose lipids to additional surfactant is preferably in the range of 4:1 to 2:3.

Non-glycolipid surfactants

As already stated, the detergents according to the invention can contain at least one non-glycolipid surfactant in addition to the glycolipid biosurfactant(s) described above, with the proviso that at least one glycolipid surfactant with micellar phase is present.

The non-glycolipid surfactant can be selected from anionic surfactants, non-ionic surfactants, zwitterionic surfactants, cationic surfactants, however, when zwitterionic or cationic surfactants are present, it is desirable that they be used in small amounts, such as not more than 10% by weight of the total surfactant present.

Anionic surfactants

Examples of suitable anionic surfactants that can be used are alkylbenzene sulfonates, alkyl ether sulfates, olefin sulfonates, alkyl sulfonates, secondary alkyl sulfonates, fatty acid ester sulfonates, dialkyl sulfosuccinates, alkyl orthoxyl sulfonates and others disclosed in the literature, particularly "Surface Active Agents" Volume 1, by Schwartz and Perry, Interscience 1949 and "Surface Active Agents" Volume 2 by Schwartz, Perry and Berch (Interscience 1958) in the current edition of "McCutcheon's Emulsifiers & Detergents" published by the McCutcheon Division of Manufacturing Confectioners Company or in "Tensid-Taschenbuch", by H. Stache, 2nd edition, Carl Hanser Verlag, Munich and Vienna, 1981.

Specific examples of alkylbenzenesulfonates are alkali metal, ammonium or alkanolamine salts of alkylbenzenesulfonates having 10 to 18 carbon atoms in the alkyl group.

Suitable alkyl and alkyl ether sulfates are those having 10 to 24 carbon atoms in the alkyl group, with the alkyl ether sulfates having 1 to 5 ethylene oxide groups.

Suitable olefin sulfonates are those prepared by sulfonating C10 to C24 α-olefins and then neutralizing and hydrolyzing the sulfonation reaction product.

Specific examples of alkyl sulfates or sulfated fatty alcohol salts are those of mixed alkyl chain length, wherein the ratio of C₁₂ alkyl chains to C₁₈ alkyl chains is in the range of 9:4 to 1:6. A suitable material can be obtained from a mixture of synthetic lauryl and oleyl alcohols having suitable properties.

Specific examples of fatty acid ester sulfonates are those of the general formula

where R¹ is derived from tallow, palm or coconut oil and R² is a short chain alkyl group such as butyl.

Specific examples of dialkyl sulfosuccinates are those wherein both alkyl substituents contain at least 4 carbon atoms and together contain 12 to 20 carbon atoms in total, such as di-C8 alkyl sulfosuccinate.

Specific examples of alkyl orthoxyl sulfonates are those wherein the alkyl group contains 12 to 24 carbon atoms.

Other anionic surfactants that can be used are alkali metal soaps of a fatty acid, especially one containing 12 to 18 carbon atoms. Typical examples of such acids are oleic acid, ricinoleic acid and fatty acids derived from castor oil, rapeseed oil, peanut oil, coconut oil, palm kernel oil or mixtures thereof. The sodium or potassium soaps of these acids can be used. As well as fulfilling the role of surfactants, soaps can serve as detergent builders or as fabric conditioning agents.

Dialkyl sulfosuccinates are of particular interest as lamellar phase surfactants for use in the present invention.

Non-ionic surfactants

Nonionic detergent compounds that can be used are (C6-22)alkylphenol-ethylene oxide condensates, the condensation products of linear or branched aliphatic primary or secondary C8-20 alcohols with ethylene oxide and products prepared by condensation of ethylene oxide with the reaction products of propylene oxide and ethylenediamine. Other so-called nonionic detergent compounds are long chain tertiary amine oxides, alkyl sulfoxides, C10-C14 alkylpyrrolidones and tertiary phosphine oxides.

Suitable lamellar phase nonionic surfactants are those having an HLB value below 10.5, preferably below 10 and more preferably in the range of 8.5 to 9.5. For ethoxylated nonionic surfactants, the HLB value is defined as one-fifth of the molecule % ethylene oxide in the molecule.

Suitable non-ionic surfactants can be ethoxylated substances, in particular ethoxylated aliphatic alcohols, with relatively low ethoxylation levels, so that they result in an HLB value below 10.5.

However, it may be desirable for an ethylene oxide content of the nonionic surfactant to be < 5% by weight of the surfactant system or zero, and various non-ethoxylated nonionic surfactants are also suitable for use in the present invention.

These include alkyl polyglycosides of the general formula

R¹⁵O(R¹⁵O)t(G)y or R¹⁵ O(R¹&sup6;O)t(G)y

wherein R¹⁵ is an organic hydrophobic residue having 10 to 20 carbon atoms, R¹⁵ contains 2 to 4 carbon atoms, G is a saccharide residue having 5 to 6 carbon atoms, t is in the range of 0 to 25 and y is in the range of 1 to 10.

The hydrophobic group R¹⁵ is preferably alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl. However, it may include an aryl group, for example alkylaryl, alkenylaryl and hydroxyalkylaryl. Particularly preferred is R-alkyl or alkenyl having 10 to 16 carbon atoms, more preferably 12 to 14 carbon atoms.

The value of t in the general formula set forth above is preferably zero so that the -(R¹⁶O)t moiety of the general formula is not present.

If t is not zero, it is preferred that R¹⁶O is an ethylene oxide residue. Other possibilities are propylene oxide and glycerol residues. If the parameter t is not zero, so that R¹⁶O is present, the value of t (which may represent an average value) is preferably in the range of 0.5 to 10.

The group G is typically derived from fructose, glucose, mannose, galactose, talose, gulose, allose, altrose, idose, arabinose, xylose, lyxose and/or ribose. Preferably, G is provided essentially exclusively by glucose units. Intersaccharide bonds can be present from a 1-position to a 2-, 3-, 4- or 6-position of the subsequently attached saccharide. Hydroxyl groups on the sugar residues can be present, for example etherified with short alkyl chains of 1 to 4 carbon atoms.

The value of y, which represents an average, is preferably between 1 and 4, in particular 1 and 2.

Alkyl polyglycosides of the formula R¹⁵O(G)y, that is, a formula as set forth above in which t is zero, are available from Horizon Chemical Co.

O-alkanoylglucosides are described in the international patent application WO 88/10147 (Novo Industri A/S). In particular, the surfactants described therein are glucose esters with the acyl group bonded in the 3- or 6-position, such as 3-O-acyl-D-glucose or 6-O-acyl-D-glucose. In the present invention, we prefer the use of 6-O-alkanoylglucoside, in particular compounds of the formula:

wherein R¹⁷ represents an alkyl or alkenyl group having 7 to 19, preferably 11 to 19, carbon atoms and R¹⁷ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms.

Most preferred are those compounds in which R18 is an alkyl group such as ethyl or isopropyl. Alkylation at the 1-position enables such compounds to be prepared by regiospecific enzymatic synthesis as described by Bjorkling et al. (J. Chem. Soc., Chem. Common. 1989 p. 934), the disclosure of which is incorporated herein by reference.

Although esters of glucose are particularly considered, it is expected that corresponding materials based on other reduced sugars, such as galactose and mannose, will also be suitable.

Other possible non-ionic surfactants are monoglyceryl ethers or esters with the corresponding formulas

wherein R¹⁹9 is preferably a saturated or unsaturated aliphatic radical. In particular, R¹⁹9 may represent a linear or branched alkyl or alkenyl radical. More preferably, R¹⁹9 is essentially a linear alkyl or alkenyl radical having 9 to 16 carbon atoms, especially a C₈ to C₁₂ alkyl radical. Most preferably, R¹⁹9 is decyl, undecyl or dodecyl.

The monoglyceryl ethers of alkanols are well-known materials and can be prepared, for example, by condensation of a higher alkanol and glycidol. Glycerol monoesters are, of course, well known and available from various suppliers, including Alkyril Chemicals Inc.

Another class of nonionic surfactants that are interesting for use in the present invention includes the 1,2-diols of the general formula

R - - CH₂OH

wherein R is a saturated or unsaturated hydrocarbon group having 8 to 16 carbon atoms.

Amounts and ratios of surfactants

Agents according to the invention generally contain a surfactant mixture comprising a surfactant with a micellar phase (i) and one or more surfactants with a lamellar phase (ii) in an amount which makes up 1 to 60% by weight of the agent, preferably 2 to 45%, more preferably 5 to 40%, most preferably 5 to 35% by weight.

The amount of glycolipid biosurfactant present is more than 5% by weight of the total composition.

The range of weight ratios that will give increased detergency will vary depending on the specific surfactants used and can be determined experimentally. In general, the proportion of glycolipid biosurfactant should be low when its alkyl chains are shorter, but higher when its alkyl chains are longer.

The weight ratio of micellar phase surfactant to lamellar phase surfactant is generally in the range of 20:1 to 1:20 and may be in a narrower range, for example 10:1 to 1:10, more preferably 4:1 to 1:4.

The proportions of surfactants are desirably designed to provide better oil soil solubility than that provided by the (or other) glycolipid biosurfactant alone, the total amount of surfactant being the same.

When a non-glycolipid biosurfactant is present, ratios that provide better oil soil solubility than with the non-glycolipid surfactant alone, with the total amount of surfactant being the same, are desirable.

Detergent builder

When the composition according to the invention is intended for washing fabrics, it generally contains one or more detergent builders, suitably in an amount of 5 to 80% by weight, preferably 7 to 70% by weight, more preferably 20 to 80% by weight. When in solid form, the composition may contain at least 10 to 15% builder. This may be a substance capable of reducing the proportion of free calcium ions in the washing solution and preferably endows the agent with other advantageous properties, such as generating an alkaline pH value and suspending dirt removed from the textile.

Preferred builders are alkali metal (preferably sodium) aluminosilicates, which may suitably be used in amounts of from 5 to 60% by weight (anhydrous basis) of the composition and may be either crystalline or amorphous or mixtures thereof, having the general formula:

0.8-1.5 Na₂O Al₂O₃ 0.8-6 SiO2.

These materials contain some bound water and are required to have a calcium ion exchange capacity of at least 50 mg CaO/g. The preferred sodium aluminosilicates contain 1.5-3.5 SiO2 units (in the above formula). Both amorphous and crystalline materials can be readily prepared by reaction between sodium silicate and sodium aluminate, as described in detail in the literature.

Suitable crystalline sodium aluminosilicate ion exchange detergent builders are described, for example, in GB-A-1 429 143 (Procter & Gamble). The preferred sodium aluminosilicates of this type are the well-known commercial zeolites A and X and mixtures thereof. Also of interest is the new zeolite P described and claimed in EP-A-384 070 (Unilever).

Detergents built with phosphate are also within the scope of the invention. Examples of phosphorus-containing inorganic detergent builders are water-soluble salts, especially alkali metal pyrophosphates, orthophosphates, polyphosphates and phosphonates. Specific examples of inorganic phosphate builders are sodium and potassium tripolyphosphates, orthophosphates and hexametaphosphates.

The preferred detergents according to the invention preferably contain no more than 5% by weight of inorganic Phosphate builders and are essentially free of phosphate builders.

Other builders may also be included in the detergent of the invention if required or desired: Suitable organic or inorganic water-soluble or water-insoluble builders are known to the detergent formulator. Inorganic builders which may be present include alkali metal (generally sodium) carbonate, while organic builders which include polycarboxylate polymers such as polyacrylates, acrylic/maleic copolymers and acrylic phosphinates, monomeric polycarboxylates such as citrates, gluconates, oxydisuccinates, glycerol mono-, di- and trisuccinates, carboxymethyloxysuccinates, carboxymethyloxymalonates, dipicolinates, hydroxyethyliminodiacetates and organic precipitating builders such as alkyl and alkenyl malonates and succinates and sulfonated fatty acid salts.

Particularly preferred supplementary builders are polycarboxylate polymers, in particular polyacrylates and acrylic/maleic acid copolymers, suitably used in amounts of 0.5 to 15 wt%, in particular 1 to 10 wt%, and monomeric polycarboxylates, in particular citric acid and salts thereof, suitably used in amounts of 3 to 20 wt%, more preferably 5 to 15 wt%.

Other components

It is desirable that detergent compositions according to the invention are approximately neutral or at least slightly alkaline, that is, when the composition is dissolved in an amount to give a surfactant concentration of 1 g/l in distilled water at 25°C, the pH should desirably be at least 7.5. For solid compositions the pH will usually be higher; such as at least 9. For the required pH the compositions may include a water-soluble alkaline salt. This salt may be a detergent builder (as described above) or a non-building alkaline material.

The agents according to the invention may contain an electrolyte, for example this is present in an amount such that a concentration of at least 0.01 molar is obtained when the agent is added to water at a concentration of 1 g/l. The electrolyte concentration may possibly be higher, such as at least 0.05 to 0.1 molar, particularly when the agent is in solid form. Liquid agents are generally restricted as to the electrolyte for stability reasons. 1 g/l is about the lowest level at which laundry detergents are used in normal use. More common is the use of an amount of 4 to 50 g/l. The amount of electrolyte may be such that an electrolyte concentration of 0.01 molar, more preferably at least 0.1 molar, is achieved when the agent is added to water at a concentration of 4 g/l.

Further ingredients which may optionally be used in the detergent according to the invention include polymers with carboxylic or sulfonic acid groups in acid form or completely or partially neutralized to sodium or potassium salts, with sodium salts being preferred.

Preferred polymers are homopolymers and copolymers of acrylic acid and/or maleic acid or maleic anhydride. Of particular interest are polyacrylates, polyalphahydroxyacrylates, acrylic/maleic acid copolymers and acrylic phosphinates. Other polymers which are particularly preferred for use in liquid detergents are deflocculating polymers, for example disclosed in EP-A-346 995.

The molecular weights of the homopolymers and copolymers are generally from 1,000 to 150,000, preferably from 1,500 to 100,000. The amount of polymer can be in the range from 0.5 to 5% by weight of the agent. Other suitable polymeric substances are cellulose ethers, such as carboxymethylcellulose, methylcellulose, hydroxyalkylcelluloses and mixed ethers, such as methylhydroxyethylcellulose, methylhydroxypropylcellulose and methylcarboxymethylcellulose. Mixtures of different cellulose ethers, in particular mixtures of carboxymethylcellulose and methylcellulose, are suitable. Polyethylene glycol with a molecular weight of 400 to 50,000, preferably 1,000 to 10,000 and copolymers of polyethylene oxide with polypropylene oxide are just as suitable as copolymers of polyacrylate with polyethylene glycol. Polyvinylpyrrolidone having a molecular weight of 10,000 to 60,000, preferably 30,000 to 50,000, and copolymers of polyvinylpyrrolidone with other polypyrrolidones are suitable. Polyacrylic acid phosphinates and related copolymers having a molecular weight of 1,000 to 100,000, especially 3,000 to 30,000, are also suitable.

It may also be desirable to include in the detergent composition of the invention an amount of alkali metal silicate, particularly sodium ortho-, meta- or preferably neutral or alkaline silicate. The presence of such alkali metal silicates in amounts, for example, from 0.1 to 10% by weight may be advantageous in providing protection against corrosion of metal parts in washing machines, in addition to providing some build-up effect and processing advantage.

Further examples of other ingredients that may be present in the composition include fabric softening agents such as fatty amines, fabric softening clays, foam enhancers such as alkanolamides, in particular the monoethanolamides derived from palm kernel fatty acids and coconut fatty acids, antifoam agents, oxygen-releasing bleaches such as sodium perborate and sodium percarbonate; bleach precursors, chlorine-releasing bleaches such as trichloroisocyanuric acid, heavy metal sequestrants such as EDTA, fluorescent agents, perfumes including deodorizing perfumes, enzymes such as cellulases, proteases, lipases and amylases, germicides, pigments, colorants or colored speckles and inorganic salts such as sodium and magnesium sulfate. Sodium sulfate may, if desired, be present as a filler in amounts up to 40% by weight of the composition, but amounts of sodium sulfate may be present in amounts of 10% or less by weight of the composition, or none at all.

The detergents according to the invention can be in any suitable form, including powders, bars, liquids and pastes. Suitable liquid agents can, for example, be non-aqueous or aqueous; the latter is either isotropic or lamellar in structure. The agents can be prepared by a variety of different processes according to their physical form. In the case of granular products, they can be prepared by dry blending, coagglomeration, spray drying from an aqueous slurry, or a combination of these processes. A preferred physical form is a granular product mixed with detergent builder salt. This can be prepared by conventional granulation processes or spray drying.

Examples

The following non-limiting examples illustrate the invention. Parts and percentages are by weight unless otherwise indicated.

Rhamnolipids example 1

This example uses as the micellar phase surfactant (i) a rhamnolipid produced as a by-product during fermentation using Pseudomonas glumae with glucose and glycerol as substrates. Partial characterization of the dried material obtained from the fermentation showed that it contains one or more compounds of the above formula (I) in which the value of n is 10. The lamellar phase surfactant (ii) was an ethoxylated aliphatic alcohol.

Aqueous wash liquors were prepared using the following materials in deionized water:

Rhamnolipid (as dry material) from fermentation) ) 1 g/l

ethoxylated dodecyl alcohol with ) on average 3 ethylene oxide residues ) and sodium metaborate ) 0.05 molar

These amounts may be typical when using 6 g/l of a single detergent product containing 16.7 wt% surfactant.

The wash liquor had a pH value of about 10.7 - due to the presence of metaborate.

Wash liquors were prepared with different ratios of the two surfactants and used to wash polyester test cloths soiled with radiolabeled triolein. Washing was carried out at 40ºC for 20 minutes in a tergotometer.

Triolein removal was determined using the radiotracer technique and the results are presented in Table 1. Table 1 Rhamnolipid Wt% of active ingredient C12E3 Wt% of active ingredient % Triolein removal

All mixtures of rhamnolipid and ethoxylated non-ionic surfactant provided better detergency than either surfactant alone.

Example 2

Example 1 was repeated replacing the ethoxylated nonionic surfactant with an anionic surfactant di-C8-alkyl sulfosuccinate as lamellar surfactant (ii). The results are shown in Table 2. Table 2 Rhamnolipid wt.% of active ingredient di-C�8-sulfosuccinate of active ingredient % triolein removal

Example 3

Example 1 was repeated using a rhamnolipid as micellar surfactant (i) available under the name BioEm-LKP (trademark) from Petrogen Inc., Illinois. It was a mixture of compounds of the above formula (I) where n = 6 and b = 2, R¹ = H, R² = H. Compounds with a = 1 and a = 2 were present in approximately equal weight ratios.

Table 3 presents results that showed a quite significant synergistic effect. Table 3 Petrogen-Rhamnolipid Wt% of active ingredient C12E3 Wt% of active ingredient Triolein removal

Examples 4 to 10 The test system

Detergency performance of biosurfactants was investigated using test fabrics described in Table 4 and the test conditions are as described below. Table 4 Test cloth: Source: Test cloth type: Composition of soiling: Reflectivity of the unwashed test cloth EMPA St.Gallen Polyester/cotton 50 ml ink 100 ml olive oil 850 ml water Reflection units Laundry research Krefeld Polyester/cotton 1.72 g/l kaolin 0.16 g/l soot 0.08 g/l iron oxide (black) 0.04 g/l iron oxide (yellow) 14.00 g/l tallow sprayed onto the cloth as a CCL₄ solution.

Washing liquors

Aqueous wash liquors were prepared containing the following substances in deionized water:

Glycolipid biosurfactant(s) as dried material from fermentation) ) 0.5 g/l

and any non-glycolipid surfactant sodium metaborate ) 0.05 molar

The wash liquor had a pH of about 10, which is due to the presence of metaborate.

Test conditions

The tests were carried out in 100 ml polyethylene bottles with 30 ml/bottle of washing solution, 1 piece of 6 x 6 cm textile cloth and 1 piece of 6 x 6 cm white (clean) cotton as redeposit cloth. The ratio of cloth:lye/bottle was 1:30. A maximum of 50 of these bottles were put in a Miele TMT washing machine at 40ºC for 30 minutes. The washed test cloths were then rinsed three times with cold water before drying.

Observation procedures

The washing performance was evaluated by calculating the reflectance increase at 460 nm (for incident light < 400 nm, filtered out) (ΔR460*). [ΔR = reflectance of the washed textile (Rw) minus reflectance of the unwashed textile (Ri).]

Example 4

Various rhamnolipid samples (micellar phase) were tested in combination with the nonionic surfactant C₁₂EO₃ (ethoxylated dodecyl alcohol with an average of 3 ethylene oxide residues) (lamellar phase) in the described wash liquor. The rhamnolipid RL-BNS was produced by bacteria of the genus Pseudomonas glumae and consisted of pure rhamnolipid of formula I, where a = 2, b = 2, n = 10, R¹ = H, R² = H. BioEm-LKP (trademark) (Petrogen Inc. Illinois) is a mixture of rhamnolipids from Pseudomonas according to Example 2. The results are shown in Table 5. Table 5 Rhamnolipid wt% active ingredient

Sophoroselipids Example 5

The sophorose lipids SOL-TUBS (micellar phase) were tested in combination with various surfactants with lamellar phase in the described wash liquor. The cosurfactants tested were Synperonic A3, C₁₂-1,2-diol and C₁₀-monoglycerol ether. The results are shown in Table 6.

SOL-TUBS is a sophorose lipid from the Technical University of Braunschweig, Germany. It is produced by the yeast strain Torulopsis bombicola. It consists of a mixture of four sophorose lipids of formula (III) and (IV), at least 80% of which is the 1',4"-lactone-6',6"-diacetate lipid, where in formula (IV) R³ and R⁴ are acetyl groups, R⁵ = 1 and R⁶ = 15. As described in JAOCS 65 (9) (1990) 1460, the major fatty acid chain length in SOL-TUBS is C₁₈ (i.e. in formula (IV) R⁵ + R⁵ = C₁₆) Table 6 ΔR(460)* Additional surfactant Sophoroselipid (SOL-TUBS) % by weight of active ingredient mixture Synperonic A3 C₁₂-1,2-diol C₁₀-monoglycerol ether nb = not determined

Example 6

The sophorose lipid SOL-CH (micellar phase) was tested as described in Example 5. The results are shown in Table 7.

SOL-CH is a sophorose lipid produced by the yeast strain Torulopsis bombicola. It consists of a mixture of at least 8 sophorose lipids of formula (III) and (IV). Table 7 ΔR(460)* Additional surfactant Sophoroselipid (SOL-CH) % by weight of active ingredient mixture Synperonic A3 C₁₂-1,2-diol C₁₀-monoglycerol ether

Example 7

The sophorose lipid (SOL-COO⊃min;) (micellar phase) was tested as described in Example 5. The results are presented in Table 8.

SOL-COO⁻ is a sophorose lipid produced by the yeast strain Torulopsis bombicola and is partially hydrolyzed, that is, it has a structure (III) wherein R³ and R⁴ are H; R⁵ is 1; R⁶ is 15; R⁷ is H and R⁴ is OH. Table 8 ΔR(460)* Additional surfactant Sophoroselipid (SOL-COO⊃min;) % by weight of active ingredient mixture Synperonic A3 C₁₂-1,2-diol C₁₀-monoglycerol ether

Cellobioselipids Example 8

Cellobiose lipids (CELL-TUBS) (micellar phase) produced by fungi of the strain Ustilago maydis were tested in combination with various surfactants with lamellar phase in the described wash liquor. The cosurfactants tested were Synperonic A3, C₁₂-1,2-diol and C₁₀-monoglycerol ethers. The results are presented in Table 9.

CBL-TUBS consists of about 4 cellobiose lipids of formula (IV). In the main component, R¹ is H, R¹² is 15, R¹³ is acetyl and R¹⁴ is 4. Table 9 ΔR(460)* Additional surfactant Cellobiose lipid (CBL-TUBS) % by weight of active ingredient mixture Synperonic A3 C₁₂-1,2-diol C₁₀-monoglycerol ether nb = not determined

Example 9

Cellobiose lipids according to Example 8 were partially hydrolyzed so that in formula (IV) R¹ = H, R¹³ = H, R¹² 15, R¹³ is H, whereby the ester-bound fatty acid group with R¹⁴ is also not present. These cellobiose lipids (nicellar phase) were investigated with various cosurfactants with lamellar phase as described in Example 8. The results are shown in Table 10. Table 10 ΔR(460)* Additional surfactant Cellobiose lipid (CBL-COO⊃min;) % by weight of active ingredient mixture Synperonic A3 C₁₂-1,2-diol C₁₀-monoglycerol ether

Example 10

Trehalose lipid (THL-4) (lamellar phase) was tested in combination with Rhamnolipid BioEm-LKP as described in Example 2 (micellar phase).

The trehalose lipid THL-4 was produced by the bacterium Arthrobacter sp.Eki and consists of trehalose lipid of the formula (V) wherein R⁹, R¹⁰ and R¹¹ have on average 7 to 9 carbon atoms.

The results are presented in Table 11. Table 11 Trehalose lipid % w/w active ingredient mixture Rhamnolipid % w/w active ingredient mixture

Examples 11 and 12 The test system

The washing performance of biosurfactants was investigated using the test textile WFK 20D as described in Table 4 and the conditions described below.

Washing liquors

Aqueous wash liquors were prepared containing the following materials in deionized water:

Glycolipid biosurfactant(s) (as dried material from fermentation)

any non-glycolipid surfactant

Detergent base powder as shown in Table 12.

The total surfactant concentration was 0.5 g/l. The detergent base powder was used at 2.5 g/l. The test conditions and the observation procedures were as described for Examples 4 to 10. Table 12 - Detergent Base Powder Parts Zeolite 4A (anhydrous basis) Maleic acid/acrylic acid copolymer Sodium carbonate Alkaline silicate Sodium carboxymethyl cellulose Fluorescer Moisture + salts

Example 11

The sophorose lipids SOL-TUBS as described in Example 5 (micellar phase) were tested in combination with Synperonic A3 (lamellar phase). The results are shown in Table 13. Table 13 Sophoroselipid wt.% active ingredient mixture

Example 12

The cellobiose lipid CBL-TUBS according to Example 8 (micellar phase) was tested in combination with Synperonic A3 (lamellar phase). The results are shown in Table 14. Table 14 Cellobioselipid wt% active ingredient mixture

Claims (20)

1. A detergent composition comprising 1 to 60% by weight in total of: (i) a first surfactant which is a micellar phase surfactant of which a 1 wt% aqueous solution in demineralized water at pH 7.0 and 25°C does not exhibit birefringent textures when viewed under a polarizing optical microscope, the micellar phase surfactant being a glycolipid biosurfactant selected from sophorose lipids, rhamnolipids, glucose lipids, cellobiose lipids and mixtures thereof, and (ii) a second surfactant which is a lamellar phase surfactant of which a 1 wt% aqueous solution in demineralized water at pH 7.0 and 25°C exhibits birefringent textures when viewed under a polarizing optical microscope, the lamellar phase surfactant being a glycolipid biosurfactant selected from rhamnolipids, glucose lipids, trehalose lipids and mixtures thereof or a non-glycolipid surfactant, and optionally 5 to 80% by weight of a detergency builder, wherein the composition contains more than 5% by weight glycolipid biosurfactant. 2. Detergent according to claim 1, wherein the glycolipid biosurfactant comprises a rhamnolipid of formula (I) wherein a is 1 or 2; b is 1 or 2, n is 4 to 10; R¹ is H or a cation, R² is H or the group CH₃(CH₂)mCH = CH- - means; m is 4 to 10; and the values of m and n, if they occur, need not be equal. 3. Detergent according to claim 2, comprising as glycolipid biosurfactant a rhamnolipid of formula (I) wherein n is 6. 4. Detergent according to claim 3, comprising as glycolipid biosurfactant a rhamnolipid of formula (I) , wherein R² is H . 5. Detergent according to claim 1, comprising as glycolipid biosurfactant a glucose lipid of formula (II) wherein R¹ is H or a cation; p is 1 to 4; and q is 4 to 10. 6. Detergent according to claim 5, comprising as glycolipid biosurfactant a glucose lipid of formula (II) in which q is 6 . 7. Detergent according to claim 1, comprising as glycolipid biosurfactant a sophorose lipid of formula (III) wherein R³ and R⁴ individually represent H or an acetyl group; R⁵ represents a saturated or unsaturated, hydroxylated or non-hydroxylated hydrocarbon group having 1 to 9 carbon atoms and R⁶ represents a saturated or unsaturated, hydroxylated or non-hydroxylated hydrocarbon group having 1 to 19 carbon atoms, with the proviso that the total number of carbon atoms in the groups R⁵ and R⁴ does not exceed 20; R⁷ represents H or a lactone ring formed with R⁸; R⁷ represents OH or a lactone ring formed with R⁷. 8. Detergent according to claim 7, wherein the sophorose lipid has the formula (IV) wherein R³, R⁴, R⁵ and R⁶ are as defined in claim 7, with the proviso that at least one of R³ and R⁴ is an acetyl group. 9. Detergent according to claim 7 or 8, comprising as glycolipid biosurfactant a sophorose lipid of formula (III) or of formula (IV) in which R5 is methyl. 10. Detergent according to one of claims 7 to 9, comprising as glycolipid biosurfactant a sophorose lipid of the formula (III) or of the formula (IV) in which the total number of carbon atoms in the groups R⁵ and R⁶ is 14 to 18. 11. Detergent according to claim 1, comprising as glycolipid biosurfactant a trehalose lipid of formula (V) wherein R⁹, R¹⁰ and R¹¹ individually represent a saturated or unsaturated, hydroxylated or non-hydroxylated hydrocarbon having 5 to 13 carbon atoms. 12. Detergent according to claim 1, comprising as glycolipid biosurfactant a cellobiose lipid of formula (VI) wherein R¹ represents H or a cation; R¹² represents a saturated or unsaturated, hydroxylated or non-hydroxylated hydrocarbon having 9 to 15 carbon atoms; R¹³ represents H or an acetyl group; R¹⁴ represents a saturated or unsaturated, hydroxylated or non-hydroxylated hydrocarbon having 4 to 16 carbon atoms. 13. Detergent according to claim 11, comprising as glycolipid biosurfactant a cellobiose lipid of the formula (VI) in which R¹² is a hydrocarbon having 13 to 15 carbon atoms. 14. A detergent composition according to claim 1, wherein the surfactant with lamellar phase (ii) is selected from anionic or nonionic non-glycolipid surfactants and combinations thereof. 15. A detergent composition according to claim 14, wherein the surfactant with lamellar phase (ii) is a dialkyl sulfosuccinate, an ethoxylated alcohol, an alkanediol or a monoglyceryl ether. 16. A detergent composition according to claim 1, wherein the micellar phase surfactant (i) and the lamellar phase surfactant (ii) are both glycolipid surfactants. 17. A detergent composition according to claim 1, wherein the weight ratio of the surfactant with micellar phase (i) to the surfactant with lamellar phase (ii) is in the range of 20:1 to 1:20. 18. A detergent composition according to claim 17, wherein the weight ratio of the surfactant with micellar phase (i) to the surfactant with lamellar phase (ii) is in the range of 10:1 to 1:10. 19. Detergent according to claim 1, wherein the weight ratio of the surfactant with micellar phase (i) to the surfactant with lamellar phase (ii) is in the range of 4:1 to 1:4. 20. A method of cleaning comprising bringing textiles or other inanimate surfaces to be cleaned into contact with an agent according to claim 1, or a washing solution comprising water and an agent according to claim 1, added to water in an amount in a range of 0.5 to 50 grams per liter of water.