LAUNDRY COMPOSITION INGREDIENTS FIELD OF THE INVENTION
The present invention relates to laundry composition comprising an anionic silicone that display improved stability.
BACKGROUND OF THE INVENTION
Silicones are an attractive ingredient for laundry compositions as they provide softening benefits to the laundered fabric. Grafting a mono-anionic functionalised silicone onto a polysaccharide backbone is known from WO 2003/020770.
SUMMARY OF THE INVENTION
The prior art still has a problem that grafted silicones may lead to unstable laundry compositions, particularly when anionic silicones are used, as they are prone to cloudiness and haze. This is unacceptable for the consumer.
It is an object of the invention to improve upon the stability of formulations that include polysaccharide grafted silicones. It is particularly an object to provide a formulation that is less cloudy or hazy.
We have now found that if instead of a monofunctional anionic silicone, a multifunctional anionic silicone is grafted to the polysaccharide, then the resulting laundry detergent composition has improved stability and is less hazy or cloudy. The present invention therefore provides in a first aspect of the invention, a
polysaccharide having an anionic functional silicone grafted thereto, wherein the silicone has at least one residual anionic group.
Preferably the polysaccharide is selected from: poly-glucose, poly-mannose, gluco- mannan, galacto-mannan and xylo-glucan polysaccharides. More preferably the polysaccharide is galacto-mannan and/or xylo-glucan.
Preferably the polysaccharide is a nonionic polysaccharide or a cationic polysaccharide.
Preferably the anionic silicone incorporates carboxylic, sulphate, sulphonic, phosphate and/or phosphonate functionality. More preferably the anionic silicones are carboxyl functionalised silicones. Preferably the anionic silicone once grafted has an anionic group content of at least 0.1 mol%, preferably 0.5 mol%, more preferably 1 mol%, most preferably 2 mol%.
Preferably the polysaccharide is a galacto-mannan and/or xylo-glucan having a silicone grafted thereto, wherein the silicone has at least 1 carboxyl group, preferably 2 carboxy groups after grafting.
A second aspect of the invention is a laundry treatment composition comprising:
a) from 1 to 40 wt.% of surfactant, comprising anionic and optionally nonionic surfactant; and,
b) from 0.05 to 10 wt.% of a polysaccharide having an anionic functional silicone grafted thereto, wherein the silicone has at least one residual anionic group.
Preferably the laundry treatment composition is in the form of a main wash laundry detergent.
Preferably the laundry treatment composition comprises from 2.5 to 25 wt.%, more preferably from 4 to 20 wt.% of an anionic surfactant.
Preferably the laundry treatment composition comprises from 0.5 to 25 wt.% more preferably from 2.5 to 15 wt.% of a nonionic surfactant, and optionally a fatty acid or soap thereof.
Preferably the laundry treatment formulation contains from 0.05 to 2.5 wt.%, of a cationic polymer, more preferably a cationic polysaccharide, most preferably a cationic cellulose polymer.
Preferably the laundry treatment composition comprises:
a) from 6.5 to 38 wt.% of surfactant, comprising from 4 to 20 wt.% of an anionic and from 2.5 to 15 wt.% of a nonionic surfactant;
b) from 0.05 to 10 wt.% of a galacto-mannan and/or xylo-glucan having a silicone grafted thereto, wherein the silicone has at least 1 carboxyl group, preferably 2 carboxy groups after grafting;
c) from 0.5 to 2.5 wt.%, of a cationic polysaccharide polymer; and,
d) optionally from 1 to 12 wt.% of a fatty acid.
A third aspect of the invention is to the use of a polysaccharide having an anionic functional silicone grafted thereto, wherein the silicone has at least one residual anionic group, soften fabrics.
DETAILED DESCRIPTION OF THE INVENTION
Polysaccharide grafted anionic functional silicone
A polysaccharide is a long chain polymer type material made up of the same or different saccharide rings. The polysaccharide may be straight chain, or branched.
Examples of straight chain polysaccharides are poly-glucose and poly-mannose polysaccharides. Examples of branched polysaccharides are gluco-mannan, galacto- mannan and xylo-glucan polysaccharides.
Preferably the polysaccharide is selected from: poly-glucose, poly-mannose, gluco- mannan, galacto-mannan and xylo-glucan polysaccharides. More preferably the polysaccharide is galacto-mannan and/or xylo-glucan. Anionic silicone
The polysaccharide has an anionic functional silicone grafted thereto. By anionic functional silicone is meant that the silicone, once grafted to the polysaccharide, has at least one residual anionic group remaining. Preferably the silicone, once grafted to the polysaccharide has at least 2 anionic groups, more preferably at least 3 anionic groups. Preferably the silicone, once grafted to the polysaccharide has from 1 to 10, more preferably from 2 to 10, most preferably from 3 to 10 anionic groups.
The anionic group can be detected using methods available in the field, for example NMR or IR spectroscopy.
The grafting of an anionic silicone to the polysaccharide will generally require reaction via the anionic group. Thus when using a mono-functional anionic silicone, the anionic group is used up to enable grafting to the polysaccharide. This means that the silicone once grated onto the polysaccharide will not have any anionic groups remaining.
The inventions requires there to be at least one anionic moiety remaining on the grafted silicone. This provides a laundry detergent composition has improved stability and is less hazy or cloudy. Preferably the anionic silicone once grafted has an anionic group content of at least 0.1 mol%, preferably 0.5 mol%, more preferably 1 mol%, most preferably 2 mol%.
Examples of anionic silicones are silicones that incorporate carboxylic, sulphate, sulphonic, phosphate and/or phosphonate functionality.
Preferred anionic silicones are carboxyl functionalised silicones.
Preferably at least one residual charged species remaining on the anionic silicone is provided by a carboxy silicone.
Preferably the polysaccharide is a galacto-mannan and/or xylo-glucan having a silicone grafted thereto, wherein the silicone has at least 1 carboxyl group, preferably 2 carboxy groups after grafting. For the purposes of the invention disclosed herein, the anionic silicone may be in the form of the acid or the anion. For example for the carboxyl functionalised silicone, it may be present as a carboxylic acid or carboxylate anion.
Preferably the anionic silicone has a molecular weight of from 1 ,000 to 100,000, more preferably from 2,000 to 50,000 even more preferably from 5,000 to 50,000, most preferably from 10,000 to 50,000.
Laundry Treatment Compositions
The invention also relates to a laundry treatment composition comprising:
a) from 1 to 40 wt.% of surfactant, comprising anionic and optionally nonionic surfactant; and,
b) from 0.05 to 10 wt.% of a polysaccharide having an anionic functional silicone grafted thereto wherein the silicone has at least one residual anionic group.
Preferably the laundry treatment composition is in the form of a main wash laundry detergent
Main Wash Detergent Product Form
The laundry treatment composition can take any of a number of forms: examples include powders, granules, bars, gels and liquids. Preferably the composition is in the form of a liquid laundry product. Preferably they are main wash products. It can take the form of a laundry composition for the main wash, which may be dilutable or non-dilutable. The laundry composition may for example be an isotropic liquid, or a surfactant-structured liquid. Particularly preferred forms of this invention include combination
detergent/softener products to provide "softening in the wash". Preferably the detergent composition has a pH of from 6 to 10, more preferably from pH 6.5 to 9.5, most preferably from pH 7 to 9, for example from pH 7.5 to 8.5.
Surfactants
The laundry treatment composition will generally comprise surfactant, especially when it takes the form of a main wash detergent composition.
The laundry treatment composition comprises from 1 to 40 wt.% of surfactant, comprising anionic and optionally nonionic surfactant. Preferably the laundry treatment composition comprises from 2.5 to 25 wt.% of an anionic surfactant.
Preferably in addition to the above anionic surfactant, the laundry treatment composition comprises from 0.5 to 25 wt.% of a nonionic surfactant, and optionally a fatty acid or soap
thereof. More preferably the main wash detergent composition comprises from 4 to 20 wt.% of an anionic surfactant; from 2.5 to 15 wt.% of a nonionic surfactant, and optionally a fatty acid or soap thereof. The surfactants may be chosen from the surfactants described in "Surface Active Agents" Vol. 1 , by Schwartz & Perry, Interscience 1949, Vol. 2 by Schwartz, Perry & Berch, Interscience 1958, in the current edition of "McCutcheon's Emulsifiers and Detergents" published by Manufacturing Confectioners Company or in "Tenside-Taschenbuch", H. Stache, 2nd Edn., Carl Hauser Verlag, 1981 . Preferably the surfactants used are saturated.
Suitable nonionic detergent compounds which may be used include, in particular, the reaction products of compounds having a hydrophobic group and a reactive hydrogen atom, for example, aliphatic alcohols, acids, amides or alkyi phenols with alkylene oxides, especially ethylene oxide either alone or with propylene oxide. Specific nonionic detergent compounds are C6 to C22 alkyi phenol-ethylene oxide condensates, generally 5 to 25 EO, i.e. 5 to 25 units of ethylene oxide per molecule, and the condensation products of aliphatic Cs to C18 primary or secondary linear or branched alcohols with ethylene oxide, generally 5 to 40 EO.
The nonionic surfactant if present, preferably comprises alcohol ethoxylate.
The alcohol ethoxylates are formed from the reaction of primary or secondary alcohols with ethylene oxide. Typicially an aliphatic Cs to C18 primary or secondary linear or branched alcohol is reacted with ethylene oxide in the required molar amount to produce the alcohol ethoxylate. Preferred alcohol ethoxylates have from 2 to 40, preferably from 3 to 30, more preferably from 5 to 20 ethylene oxide units attached to the aliphatic chain.
Suitable anionic detergent compounds which may be used can be water-soluble alkali metal salts of organic sulphates and sulphonates having alkyi radicals containing from about 8 to about 22 carbon atoms, the term alkyi being used to include the alkyi portion of higher acyl radicals. Examples of suitable synthetic anionic detergent compounds are sodium and potassium alkyi sulphates, especially those obtained by sulphating higher Cs to C18 alcohols, produced for example from tallow or coconut oil, sodium and potassium
alkyl Cg to C20 benzene sulphonates, particularly sodium linear secondary alkyl C10 to C15 benzene sulphonates; and sodium alkyl glyceryl ether sulphates, especially those ethers of the higher alcohols derived from tallow or coconut oil and synthetic alcohols derived from petroleum. The preferred anionic detergent compounds are sodium Cn to C15 alkyl benzene sulphonates and sodium C12 to C18 alkyl sulphates. Salts of sulphonates included as hydrotrobes can additionally be considered as anionic surfactants as defined herein. Also applicable are surfactants such as those described in EP-A-328 177 (Unilever), which show resistance to salting-out, the alkyl polyglycoside surfactants described in EP-A-070 074, and alkyl monoglycosides.
The surfactant system comprises anionic and non-ionic surfactant.
The nonionic detergent is preferably present in amounts of from 0.5 to 25 wt.%, preferably from 1 to 20 wt.%, more preferably from 2.5 to 15 wt.%.
A preferred nonionic surfactant is C12-C15 alkyl chain with an average of 7 to 9 moles of ethoxylation.
The anionic surfactant is preferably present in amounts of from 4 to 40 wt.%, preferably from 5 to 35 wt.%, more preferably from 6 to 20 wt.%.
Preferred anionic surfactants are: linear alkyl benezene sulphonates, sodium lauryl ether sulphonates with 1 to 3 moles (average) of ethoxylation, primary alkyl sulphonates, methyl ether sulphates and secondary alkyl sulphonates or mixtures thereof.
For the purposes of interpreting the level of surfactant present in the formulation, fatty acid and their salts are not included in the level of surfactant.
Other surfactants such as amphoteric, zwitterionic and cationic surfactants may also be present in addition to the aforementioned nonionic and anionic surfactants.
Further Ingredients
The laundry treatment composition may further optionally comprise one or more of the following optional ingredients, cationic polymers, silicones, fatty acids or salts thereof,
shading dye, enzyme, antiredeposition polymer, dye transfer inhibiting polymer, builder, sequestrant, sunscreen, fluorescer, perfume, and/or soil release polymer.
Cationic Polymer
The laundry treatment formulation may contain a cationic polymer at a level of from 0.05 to 2.5 wt.%, preferably from 0.1 to 2 wt.%, more preferably from 0.1 to 1 wt.%, most preferably from 0.1 to 0.75 wt.%.
The cationic polymers can be synthesised in, and are commercially available in, a number of different molecular weights. Preferably the molecular weight of the cationic polymer is from 10,000 to 2,000,000 Daltons, more preferably from 100,000 to 1 ,000,000 Daltons, even more preferably from 250,000 to 1 ,000,000 Daltons.
Preferably it is a cationic polysaccharide polymer, more preferably a cationic cellulose polymer, most preferably a hydroxyethyl cellulose. An example is LR400 from Amerchol ex Dow.
Silicones
The laundry treatment formulation may contain a silicone at a level of from 0.05 to 5 wt.%. Examples include PDMS, ethoxylated or propoxylated polysiloxanes, aminosilicones and anionic silicones such as silicones that incorporate a carboxylic, sulphate, sulphonic, phosphate and/or phosphonate functionality.
Fatty Acids
The compositions may also comprise a fatty acid, or a fatty acid salt such as a soap.
Examples include C6-C22 fatty acids and sodium, potassium and ammonium salts thereof. For the purposes of interpreting the level of surfactant present in the formulation, fatty acid and their salts are not included in the level of surfactant.
If present, then fatty acid is present at a level of from 0.25 to 12 wt.%, preferably from 0.5 to 10 wt.%.
Builders and sequestrants
The detergent formulation may optionally contain a solid inorganic builder. Examples include carbonates, sulphates, silicates and their salts thereof, preferably sodium salts; and also zeolites.
The detergent compositions may also or alternatively optionally contain relatively low levels of organic detergent builder or sequestrant material. Examples include the alkali metal, citrates, succinates, malonates, carboxymethyl succinates, carboxylates, polycarboxylates and polyacetyl carboxylates. Specific examples include sodium, potassium and lithium salts of oxydisuccinic acid, mellitic acid, benzene polycarboxylic acids, ethylene diamine tetra-acetic acid, diethylenetriamine-pentaacetic acid, alkyl- or alkenylsuccinic acid, nitrilotriacetic acid, and citric acid. Other examples are
DEQUEST™, organic phosphonate type sequestering agents sold by Thermophos and alkanehydroxy phosphonates.
Other suitable organic builders include the higher molecular weight polymers and copolymers known to have builder properties. For example, such materials include appropriate polyacrylic acid, polymaleic acid, and polyacrylic/polymaleic acid copolymers and their salts, such as those sold by BASF under the name SOKALAN™. Another suitable builder is sodium carbonate.
If utilized, the builder materials may comprise from about 0.5% to 80 wt%, preferably from 1 wt% to 70 wt%, of the composition. Preferably the laundry detergent formulation is a non-phosphate built laundry detergent formulation, i.e., contains less than 1 wt.% of phosphate.
Shading Dye
Shading dyes deposit to fabric during the wash or rinse step of the washing process providing a visible hue to the fabric. Shading of white garments may be done with any colour depending on consumer preference. Blue and Violet are particularly preferred shades and consequently preferred dyes or mixtures of dyes are ones that give a blue or violet shade on white fabrics. The shading dyes used are preferably blue or violet.
The shading dye chromophore is preferably selected from the group comprising: mono- azo, bis-azo, triphenylmethane, triphenodioxazine, phthalocyanin, naptholactam, azine and anthraquinone. Most preferably mono-azo, bis-azo, azine and anthraquinone. Most preferably the dye bears at least one sulfonate group.
Preferred shading dyes are selected from direct dyes, acid dyes, hydrophobic dyes, cationic dyes and reactive dyes. If included, the shading dye is present is present in the composition in range from 0.0001 to 0.01 wt %.
Fluorescent Agent
The composition preferably comprises a fluorescent agent (optical brightener).
Fluorescent agents are well known and many such fluorescent agents are available commercially. Usually, these fluorescent agents are supplied and used in the form of their alkali metal salts, for example, the sodium salts. The total amount of the fluorescent agent or agents used in the composition is generally from 0.005 to 2 wt.%, more preferably 0.01 to 0.1 wt.%.
Perfume
Preferably the composition comprises a perfume. The perfume is preferably in the range from 0.001 to 3 wt.%, most preferably 0.1 to 1 wt.%. Many suitable examples of perfumes are provided in the CTFA (Cosmetic, Toiletry and Fragrance Association) 1992 International Buyers Guide, published by CFTA Publications and OPD 1993 Chemicals
Buyers Directory 80th Annual Edition, published by Schnell Publishing Co.
It is commonplace for a plurality of perfume components to be present in a formulation. In the compositions of the present invention it is envisaged that there will be four or more, preferably five or more, more preferably six or more or even seven or more different perfume components.
Polymers
The composition may comprise one or more polymers. Polymers can assist in the cleaning process by helping to retail soil in solution or suspension and/or preventing the transfer of dyes. Polymers can also assist in the soil removal process. Dye transfer, anti- redeposition and soil-release polymers are described in further detail below.
The composition may comprise one or more polymers. Examples are
carboxymethylcellulose, hydroxyethyl cellulose, hydroxpropyl cellulose, poly(ethylene glycol), polyvinyl alcohol), ethoxylated polyamines, polycarboxylates such as
polyacrylates, maleic/acrylic acid copolymers and lauryl methacrylate/acrylic acid copolymers.
Dye transfer inhibitors
Modern detergent compositions typically employ polymers as so-called 'dye-transfer inhibitors'. These prevent migration of dyes, especially during long soak times.
Generally, such dye-transfer inhibiting agents include polyvinyl pyrrolidone polymers, polyamine N-oxide polymers, copolymers of N-vinylpyrrolidone and N-vinylimidazole, manganese pthalocyanine, peroxidases, and mixtures thereof, and are usually present at a level of from 0.01 to 10 wt.% based on total amount in the laundry composition.
Anti-redeposition polymers
Anti-redeposition polymers are designed to suspend or disperse soil. Typically antiredeposition polymers are ethoxylated and or propoxylated polyethylene imine materials.
Soil Release Polymers
Examples of suitable soil release polymers include graft copolymers of polyvinyl ester), e.g., Ci -C6 vinyl esters, preferably polyvinyl acetate) grafted onto polyalkylene oxide backbones. Commercially available soil release agents of this kind include the
SOKALAN type of material, e.g., SOKALAN HP-22, available from BASF (Germany). Further suitable soil release polymers of a different type include the commercially available material ZELCON 5126 (from DuPont) and MI LEASE T (from ICI). If present, the soil release polymer may be included at a level of from from 0.01 to 10 wt.% based on total amount in the laundry composition. Further examples of soil release polymers are
terephthalic acid / glycol copolymers sold under the tradenames Texcare, Repel-o-tex, Gerol, Marloquest, Cirrasol.
Hydrotrope
If in the form of a liquid, then the liquid detergent composition may optionally include a hydrotrope, which can prevent liquid crystal formation. The addition of the hydrotrope thus aids the clarity/transparency of the composition. Suitable hydrotropes include but are not limited to propylene glycol, ethanol, glycerol, urea, salts of benzene sulphonate, toluene sulphonate, xylene sulphonate or cumene sulphonate. Suitable salts include but are not limited to sodium, potassium, ammonium, monoethanolamine, triethanolamine. Salts of sulphonates can also be considered as anionic surfactants as defined herein. Preferably, the hydrotrope is selected from the group consisting of propylene glycol, xylene sulfonate, ethanol, and urea to provide optimum performance. The amount of the hydrotrope is generally in the range of from 0 to 30%, preferably from 0.5 to 30%, more preferably from 0.5 to 30%, most preferably from 1 to 15%.
Enzymes
Enzymes can also be present in the formulation. Preferred enzymes include protease, lipase, pectate lyase, amylase, cutinase, cellulase, mannanase. If present the enzymes may be stabilized with a known enzyme stabilizer for example boric acid.
The invention will now be demonstrated by the following non-limiting examples.
Examples
Example 1 : Comparing the compatibility of anionic functionalised versus non-anionic functionalised silicone grafted polysaccharides
Synthesis 1 : Grafting multifunctional carboxylic silicone to xyloglucan to provide an
anionic functionalised silicone grafted polysaccharide (invention example) To 5g (0.28mmol) of carboxylic functional silicone fluid (supplied by Wacker Silicone) 4ml of oxalyl chloride was added and mixed well. The reaction was monitored by the evolution of volatile gas, and the reaction continued until effervescence had ceased. Sodium bicarbonate was added to quench unreacted oxalyl chloride. Acyl chloride functional silicone was dissolved in 25ml of dichloromethane then, with rapid stirring, 1 g of xyloglucan powder and 5ml of triethylamine were added. The reaction was heated to
40°C and allowed to react until the dichloromethane has boiled off, leaving the product dispersed in triethylamine.
The resulting polysaccharide grafted silicone has residual anionic groups remaining after the grafting process is over.
Synthesis A: Grafting monofunctional carboxylic silicone to xyloqlucan to provide a non- anionic functionalised silicone grafted polysaccharide (comparative example)
The procedure detailed in WO 2003/020770 was repeated using 0.28mmoles of X-22- 3710 (monofunctional carboxylic silicone supplied by Shin Etsu) and replacing the cellulose monoacetate with xyloglucan (1 g as in synthesis #1 ).
By using a mono-functionalised anionic silicone, the grafting process uses up this anionic functionality, to deliver a polysaccharide grafted silicone which has no anionic groups remaining post-grafting.
Test Formulation
Compatibility experiment:
The product of synthesis 1 or synthesis A was added to the test formulation to prepare a 0.5% active level of xyloglucan grafted silicone. The resulting formulation was assessed in two ways. The first assessment was a visual assessment to see if the formulation was clear or cloudy/hazy. The second assessment was by absorbance at 500nm. A sample
was decanted into a 1 cm cuvette then measured for clarity in a UV-visible spectrometer at a wavelength of 500nm, with the results given in comparison to the control test formulation. The higher the +ve value, the less clear the sample is.
The results show a clear stability advantage in terms of providing a less cloudy/hazy formulation for the silicone grafted polysaccharide having anionic groups remaining in comparison to grating using a mono-functional silicone which results in a silicone grafted polysaccharide having no anionic groups remaining.