EP2496676B1

EP2496676B1 - Laundry compositions

Info

Publication number: EP2496676B1
Application number: EP09748116.2A
Authority: EP
Inventors: Paul Ferguson; Christopher Clarkson Jones
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 2009-11-05
Filing date: 2009-11-05
Publication date: 2016-06-29
Anticipated expiration: 2029-11-05
Also published as: BR112012010662A2; WO2011054389A1; ES2593808T3; EP2496676A1; CN102695786A; CN102695786B

Description

FIELD OF THE INVENTION

This invention relates to improvement to laundry compositions. More particularly, the invention is directed to laundry compositions comprising perfume and micro-fibrous cellulose.

BACKGROUND OF THE INVENTION

Perfume is an important ingredient of laundry products. The perfume provides a pleasing fragrance for the consumer and is a sensorial cue that the product has performed its intended function, providing clean and fresh laundered garments. Perfume however is an expensive component, and a problem in the field is that perfume deposition from laundry products is inefficient.
There is thus a need to increase the efficiency of deposition of perfume.
EP 1 844 759 (A1) discloses compositions which increase perfume deposition comprising a fragrance material, a derivatised polysaccharide, a branched polyglycerol-modified silicone and a surfactant. It is believed therein that the perfume deposition enhancement is attributable to the synergistic effect between the derivatised polysaccharide and the branched polyglycerol-modified silicone.
US patent application US 2007/0197779 discloses a structurant consisting of bacterially produced micro-fibrous cellulose combined with carboxy methyl cellulose and xanthan gum as dispersion aids.
US 2008/0108541 and US 2008/0146485 disclose surfactant systems which use micro-fibrous cellulose to suspend particulates therein.
WO 2009/101545 discloses a structured liquid detergent composition in the form of a liquid matrix made up of an external structuring system of a bacterial cellulose network; water; and surfactant system including an anionic surfactant; a nonionic surfactant; a cationic surfactant; an ampholytic surfactant; a zwitterionic surfactant; or mixtures thereof.
WO 2008/145547 discloses a process for the manufacture of core-shell perfume particles by emulsion polymerisation and to the products obtainable by such a process. The core of the particles comprises a perfume and the shell (which preferably comprises an aminoplast polymer) also comprises a non-ionic deposition aid (such as locust bean gum) which is substantive to textiles.
WO 2007/062833 provides an encapsulate comprising a benefit agent core (preferably containing perfume), one or more inner shells (preferably of melamine urea or melamine formaldehyde) and an outer shell comprising a polymer.
The applicants have found that micro-fibrous cellulose can be used to increase the deposition of perfume on fabric, thus solving the aforementioned problem.

SUMMARY OF THE INVENTION

The invention relates to the use of micro-fibrous cellulose to increase the deposition of perfume particles on fabric.
The micro-fibrous cellulose may be used as part of a laundry composition.

DETAILED DESCRIPTION OF THE INVENTION

As used herein, the term "comprising" means including, made up of, composed of, consisting and/or consisting essentially of.
All percentages quoted are wt.% unless otherwise stated.
As used herein, a formula shall be considered physically "stable" when after 1 week at 21 degrees Celsius it exhibits no signs of phase separation.

Process to make the laundy composition

The process to make a laundry detergent composition comprising micro-fibrous cellulose comprises mixing together in any order 5 to 80 wt.% of an anionic and/or nonionic surfactant, 0.001 to 5 wt.% micro-fibrous cellulose and 0.025 to 10 wt.% perfume particles.
Preferably the micro-fibrous cellulose is added to the surfactant as a pre-mix in water.
Preferably the perfume particles are post-dosed to the surfactant.

Form of the Invention

The emulsion can be included in laundry detergent products taking a number of forms.
The laundry detergent composition may be a main wash composition, a rinse composition, or a pre- or after-wash treatment composition, all of which may be dilutable or non-dilutable. Main wash compositions are preferred.
The compositions of the invention may be in any physical form e.g. a solid such as a powder or granules, a tablet, a solid bar, a paste, gel or liquid, especially, an aqueous based liquid. In particular the compositions may be used in laundry compositions, especially in liquid, gel, powder or tablet laundry composition.
If the laundry detergent composition is a main wash composition, then the pH range of the composition is from pH 7-12, preferably from pH 8.5 to 9.5. It is desirable to buffer the formulation at whatever the target pH of the composition is.
The invention relates to the use of micro-fibrous cellulose to increase the deposition of perfume particles on fabric. The preferred substrate for deposition is clothes.
The use of micro-fibrous cellulose is particularly applicable for compositions which comprise perfume particles which are in the form of perfume encapsulates.
The use of micro-fibrous cellulose is also especially applicable for perfume particles (particularly perfume encapsulates) which have been modified by a deposition aid.
The deposition aid in this case is preferably a polysaccharide, more preferably locust bean gum.

COMPONENTS

Micro-fibrous Cellulose:

Preferred micro-fibrous celluloses suitable for use in embodiments of the present invention include those described in US 2007/019779 (CP Kelco). Particular preferred materials are those obtained from Acetobacter. These materials are available in the marketplace from CP Kelco (Atlanta, Georgia USA).
The micro-fibrous cellulose has an individual fibre diameter of from about 40nm to 0.5µm, for example 0.1 µm.
The micro-fibrous cellulose is non-ionic.
The micro-fibrous cellulose (MFC) is present at a level of from 0.001 to 5 wt.%, preferably from 0.01 to 2.5 wt.%, more preferably 0.01 to 1 wt.%, optionally from 0.02 to 0.75 wt.%, for example from 0.025 to 0.4 wt.%.

Perfume:

The perfume is present in the form of perfume particles. These particles are incorporated in the laundry composition at a level of from 0.001 to 10 wt.%, preferably 0.0025 to 3 wt.%, most preferably 0.05 to 2 wt.%.
The perfume is typically present in an amount of from 10 to 85 wt.% by total weight of the perfume particle, preferably from 20 to 75 wt.% of the particle.
The perfume suitably has a molecular weight of from 50 to 500.
While it is preferred to use polymer particles for the perfume particles, preferably polymeric core-shell perfume encapsulates, many other types of particle can be envisaged as the carrier. Perfumes have been adsorbed onto a clay or zeolite material that is then admixed into particulate detergent compositions: U.S. Pat. No. 4,539,135 discloses particulate laundry compounds comprising a clay or zeolite material carrying perfume. Other perfume delivery systems are taught by WO 97/34982 and WO 98/41607 , published by The Procter & Gamble. WO 97/34982 discloses particles comprising perfume loaded zeolite and a release barrier, which is an agent derived from a wax and having a size (i.e., a cross-sectional area) larger than the size of the pore openings of the zeolite carrier. WO 98/41607 discloses glassy particles comprising agents useful for laundry or cleaning compositions and a glass derived from one or more of at least partially-water-soluble hydroxylic compounds.
Silicas, amorphous silicates, crystalline nonlayer silicates, layer silicates, calcium carbonates, calcium/sodium carbonate double salts, sodium carbonates, sodalites, alkali metal phosphates, pectin, chitin microbeads, carboxyalkylcelluloses, gums, resins, gelatin, gum arabic, porous starches, modified starches, carboxyalkyl starches, cyclodextrins, maltodextrins, synthetic polymers such as polyvinyl pyrrolidone (PVP), polyvinyl alcohol (PVA), cellulose ethers, polystyrene, polyacrylates, polymethacrylates, polyolefins, aminoplast polymers, crosslinkers and mixtures thereof can all provide a basis for perfume particles.
Aminoplast core-shell particles are particularly preferred.
Suitable particle sizes for the benefit agent range from nanometre scale to micron scale and even to millimetre scale. Typical particle sizes range from 1 micron to 1 mm, with, for encapsulated perfumes, particle sizes in the range of 5-50 microns being preferred, especially particles of 10-30 microns. Larger particles can be employed in the form of functional, but visible "beads", typically of a size range of 0.1-5mm.
When the perfume particles are present at a level of 1.5 wt.% and have a polymeric melamine-formaldehyde shell, then the perfume particles additionally comprise a deposition aid.

Perfume particle deposition aid

The perfume particles are preferably provided with a deposition aid. A deposition aid can preferably be incorporated in the shell of an encapsulated perfume particle. The deposition aid is preferably attached to the particle by means of a covalent bond, entanglement or strong adsorption, preferably by a covalent bond or entanglement and most preferably by means of a covalent bond. By entanglement as used herein is meant that the deposition aid is for example adsorbed onto the particle as polymerisation proceeds and the particle grows in size, part of the adsorbed deposition aid becomes buried within the interior of the particle. The deposition aid can be nonionic, cationic or anionic.
In one preferred embodiment, the deposition aid is a polysaccharide. In these embodiments the polysaccharide preferably has a ß-1,4-linked backbone and is substantive to cellulose.
Preferably, the polysaccharide is cellulose, a cellulose derivative, or another β-1,4-linked polysaccharide having an affinity for cellulose, such as polymannan, polyglucan, polyglucomannan, polyxyloglucan and polygalactomannan or a mixture thereof. More preferably, the polysaccharide is selected from the group consisting of polyxyloglucan and polygalactomannan. For example, preferred polysaccharides are locust bean gum, tamarind xyloglucan, guar gum or mixtures thereof. Most preferably, the deposition aid is locust bean gum.

Perfume components

Useful components of the perfume include materials of both natural and synthetic origin. They include single compounds and mixtures. Specific examples of such components may be found in the current literature, e.g., in Fenaroli's Handbook of Flavor Ingredients, 1975, CRC Press; Synthetic Food Adjuncts, 1947 by M. B. Jacobs, edited by Van Nostrand; or Perfume and Flavor Chemicals by S. Arctander 1969, Montclair, N.J. (USA). These substances are well known to the person skilled in the art of perfuming, flavouring, and/or aromatizing consumer products, i.e., of imparting an odour and/or a flavour or taste to a consumer product traditionally perfumed or flavoured, or of modifying the odour and/or taste of said consumer product.
By perfume in this context is not only meant a fully formulated product fragrance, but also selected components of that fragrance, particularly those which are prone to loss, such as the so-called 'top notes'. The perfume component could also be in the form of a profragrance.
WO 2002/038120 (P&G), for example, relates to photo-labile pro-fragrance conjugates which upon exposure to electromagnetic radiation are capable of releasing a fragrant species.
Top notes are defined by Poucher (Journal of the Society of Cosmetic Chemists 6(2):80 [1955]). Examples of well known top-notes include citrus oils, linalool, linalyl acetate, lavender, dihydromyrcenol, rose oxide and cis-3-hexanol. Top notes typically comprise 15 to 25 wt.% of a perfume composition and in those embodiments of the invention which contain an increased level of top-notes it is envisaged at that least 20 wt.% would be present within the encapsulate.
Typical perfume components which it is advantageous to encapsulate, include those with a relatively low boiling point, preferably those with a boiling point of less than 300°C, preferably 100 to 250°C.
It is also advantageous to encapsulate perfume components which have a low LogP (i.e. those which will be partitioned into water), preferably with a LogP of less than 3.0. These materials, of relatively low boiling point and relatively low LogP have been called the "delayed blooming" perfume ingredients and include the following materials:

Allyl Caproate, Amyl Acetate, Amyl Propionate, Anisic Aldehyde, Anisole, Benzaldehyde, Benzyl Acetate, Benzyl Acetone, Benzyl Alcohol, Benzyl Formate, Benzyl Iso Valerate, Benzyl Propionate, Beta Gamma Hexenol, Camphor Gum, Laevo-Carvone, d-Carvone, Cinnamic Alcohol, Cinamyl Formate, Cis-Jasmone, cis-3-Hexenyl Acetate, Cuminic Alcohol, Cyclal C, Dimethyl Benzyl Carbinol, Dimethyl Benzyl Carbinol Acetate, Ethyl Acetate, Ethyl Aceto Acetate, Ethyl Amyl Ketone, Ethyl Benzoate, Ethyl Butyrate, Ethyl Hexyl Ketone, Ethyl Phenyl Acetate, Eucalyptol, Eugenol, Fenchyl Acetate, Flor Acetate (tricyclo Decenyl Acetate), Frutene (tricyclco Decenyl Propionate), Geraniol, Hexenol, Hexenyl Acetate, Hexyl Acetate, Hexyl Formate, Hydratropic Alcohol, Hydroxycitronellal, Indone, Isoamyl Alcohol, Iso Menthone, Isopulegyl Acetate, Isoquinolone, Ligustral, Linalool, Linalool Oxide, Linalyl Formate, Menthone, Menthyl Acetphenone, Methyl Amyl Ketone, Methyl Anthranilate, Methyl Benzoate, Methyl Benyl Acetate, Methyl Eugenol, Methyl Heptenone, Methyl Heptine Carbonate, Methyl Heptyl Ketone, Methyl Hexyl Ketone, Methyl Phenyl Carbinyl Acetate, Methyl Salicylate, Methyl-N-Methyl Anthranilate, Nerol, Octalactone, Octyl Alcohol, p-Cresol, p-Cresol Methyl Ether, p-Methoxy Acetophenone, p-Methyl Acetophenone, Phenoxy Ethanol, Phenyl Acetaldehyde, Phenyl Ethyl Acetate, Phenyl Ethyl Alcohol, Phenyl Ethyl Dimethyl Carbinol, Prenyl Acetate, Propyl Bornate, Pulegone, Rose Oxide, Safrole, 4-Terpinenol, Alpha-Terpinenol, and /or Viridine.

It is commonplace for a plurality of perfume components to be present in a formulation. In the particles used herein, 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 from the list given of delayed blooming perfumes given above present in the encapsulated perfume.
Part or all of the perfume may be in the form of a pro-fragrance. For the purposes of the present invention a pro-fragrance is any material which comprises a fragrance precursor that can be converted into a fragrance.
Suitable pro-fragrances are those that generate perfume components which are aldehydes. Aldehydes useful in perfumery include but are not limited to phenylacetaldehyde, p-methyl phenylacetaldehyde, p-isopropyl phenylacetaldehyde, methyinonyl acetaldehyde, phenylpropanal, 3- (4-t-butylphenyl)-2-methyl propanal, 3- (4-t-butylphenyl)- propanal, 3- (4-methoxyphenyl)-2-methylpropanal, 3- (4-isopropylphenyl)-2- methylpropanal, 3-(3, 4-methylenedioxyphenyl)-2-methyl propanal, 3- (4- ethylpheny)-2, 2-dimethylpropanal, phenylbutanal, 3-methyl-5-phenylpentanal, hexanal, trans-2-hexenal, cis-hex-3-enal, heptanal, cis-4-heptenal, 2-ethyl-2- heptenal, 2,6-dimethyl-5-heptenal, 2,4-heptadienal, octanal, 2-octenal, 3,7- dimethyloctanal, 3,7-dimethyl-2,6-octadien-1-al, 3,7-dimethyl-1,6-octadien-3-al, 3,7-dimethyl-6-octenal, 3,7-dimethyl-7-hydroxyoctan-1-al, nonanal, 6-nonenal, 2,4-nonadienal, 2, 6-nonadienal, decanal, 2-methyl decanal, 4-decenal, 9- decenal, 2,4-decadienal, undecanal, 2-methyldecanal, 2-methylundecanal, 2,6,10-trimethyl-9-undecenal, undec-10-enyl aldehyde, undec-8-enanal, dodecanal, tridecanal, tetradecanal, anisaldehyde, bourgenonal, cinnamic aldehyde, a-amylcinnam-aldehyde, a-hexyl cinnamaldehyde, methoxy- cinnamaldehyde, citronellal, hydroxy-citronellal, isocyclocitral, citronellyl oxyacet- aldehyde, cortexaldehyde, cumminic aldehyde, cyclamen aldehyde, florhydral, heliotropin, hydrotropic aldehyde, lilial, vanillin, ethyl vanillin, benzaldehyde, p- methyl benzaldehyde, 3,4-dimethoxybenzaldehyde, 3-and 4- (4-hydroxy-4- methyl-pentyl)-3-cyclohexene-1-carboxaldehyde, 2,4-dimethyl-3-cyclohexene-1- carboxaldehyde, 1-methyl-3- (4-methylpentyl)-3-cyclohexen-carboxaldehyde, p- methylphenoxyacetaldehyde, and mixtures thereof.
Another group of perfumes with which the present invention can be applied are the so-called 'aromatherapy' materials. These include many components also used in perfumery, including components of essential oils such as Clary Sage, Eucalyptus, Geranium, Lavender, Mace Extract, Neroli, Nutmeg, Spearmint, Sweet Violet Leaf and Valerian. By means of the present invention these materials can be transferred to textile articles that will be worn or otherwise come into contact with the human body (such as handkerchiefs and bed-linen).
The perfume may be encapsulated alone or co-encapsulated with carrier materials, further deposition aids and/or fixatives. Preferred materials to be co-encapsulated with the perfume include waxes, paraffins, stabilizers and fixatives.
An optional yet preferred component of capsule is a formaldehyde scavenger. This is particularly advantageous in capsules which may comprise formaldehyde as a consequence of their manufacturing process or components. Formaldehyde scavenger is chosen from: sodium bisulfite, urea, cysteine, cysteamine, lysine, glycine, serine, carnosine, histidine, glutathione, 3,4-diaminobenzoic acid, allantoin, glycouril, anthranilic acid, methyl anthranilate, methyl 4-aminobenzoate, ethyl acetoacetate, acetoacetamide, malonamide, ascorbic acid, 1,3-dihydroxyacetone dimer, biuret, oxamide, benzoguanamine, pyroglutamic acid, pyrogallol, methyl gallate, ethyl gallate, propyl gallate, triethanol amine, succinamide, thiabendazole, benzotriazol, triazole, indoline, sulfanilic acid, oxamide, sorbitol, glucose, cellulose, poly(vinyl alcohol), poly(vinyl amine), hexane diol, ethylenediamine-N,N'-bisacetoacetamide, N-(2-ethylhexyl)acetoacetamide, N-(3-phenylpropyl)acetoacetamide, lilial, helional, melonal, triplal, 5,5-dimethyl-1,3-cyclohexanedione, 2,4-dimethyl-3-cyclohexenecarboxaldehyde, 2,2-dimethyl-1,3-dioxan-4,6-dione, 2-pentanone, dibutyl amine, triethylenetetramine, benzylamine, hydroxycitronellol, cyclohexanone, 2-butanone, pentane dione, dehydroacetic acid, chitosan, or a mixture thereof. Preferred formaldehyde scavengers are sodium bisulfite, ethyl acetoacetate, acetoacetamide, ethylenediamine-N,N'-bisacetoacetamide, ascorbic acid, 2,2-dimethyl-1,3-dioxan-4,6-dione, helional, triplal, lilial and mixtures thereof.

Surfactants

The laundry composition comprises a surfactant, preferably a detersive surfactant. Suitable surfactants comprise nonionic surfactants and anionic surfactants.
They 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 alkyl phenols with alkylene oxides, especially ethylene oxide either alone or with propylene oxide. Specific nonionic detergent compounds are C₆ to C₂₂ alkyl 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 C₈ to C₁₈ primary or secondary linear or branched alcohols with ethylene oxide, generally 5 to 40 EO.
Suitable anionic detergent compounds which may be used are usually watersoluble alkali metal salts of organic sulphates and sulphonates having alkyl radicals containing from about 8 to about 22 carbon atoms, the term alkyl being used to include the alkyl portion of higher acyl radicals. Examples of suitable synthetic anionic detergent compounds are sodium and potassium alkyl sulphates, especially those obtained by sulphating higher C₈ to C₁₈ alcohols, produced for example from tallow or coconut oil, sodium and potassium alkyl C₉ 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 C₁₁ to C₁₅ alkyl benzene sulphonates and sodium C₁₂ to C₁₈ alkyl sulphates. Further anionic surfactants include fatty acid-based soaps containing between C₈-C₂₆ carbon atoms. 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 total amount of surfactant present in the liquid composition is from 5 to 65 wt.%. Preferably the total amount of surfactant is from 10 to 65 wt.%, preferably from 15 to 50 wt.%.
Other surfactants such as amphoteric, zwitterionic and cationic surfactants may also be present in addition to the aforementioned nonionic and/or anionic surfactants.

Optional Ingredients

The laundry composition may additionally comprise one or more of the following optional ingredients.

Builders or Complexing Agents

The laundry composition optionally comprises from 1 to 50 wt.% of a builder. Preferably the builder is present at a level of from 1 to 40 wt.%.
Builder materials may be selected from 1) calcium sequestrant materials, 2) precipitating materials, 3) calcium ion-exchange materials and 4) mixtures thereof.
It is preferred that when an insoluble inorganic builder, e.g., zeolite is used, the size is in the range 0.1 to 10 microns (as measured by The Mastersizer 2000 particle size analyzer using laser diffraction ex Malvern™).
Examples of calcium sequestrant builder materials include alkali metal polyphosphates, such as sodium tripolyphosphate and organic sequestrants, such as ethylene diamine tetra-acetic acid.
Examples of precipitating builder materials include sodium orthophosphate and sodium carbonate.
Examples of calcium ion-exchange builder materials include the various types of water-insoluble crystalline or amorphous aluminosilicates, of which zeolites are the best known representatives, e.g. zeolite A, zeolite B (also known as zeolite P), zeolite C, zeolite X, zeolite Y and also the zeolite P-type as described in EP-A-0,384,070 .
The composition may also contain 0-50 wt.% of a builder or complexing agent such as ethylenediaminetetraacetic acid, diethylenetriamine-pentaacetic acid, alkyl- or alkenylsuccinic acid, nitrilotriacetic acid or the other builders mentioned below. Many builders are also bleach-stabilising agents by virtue of their ability to complex metal ions.
Zeolite and carbonate (carbonate (including bicarbonate and sesquicarbonate) are preferred builders.
The composition may contain as builder a crystalline aluminosilicate, preferably an alkali metal aluminosilicate, more preferably a sodium aluminosilicate. This is typically present at a level of less than 15 wt.%. Aluminosilicates are materials having the general formula:
0.8-1.5 M₂O. Al₂O₃. 0.8-6 SiO₂ where M is a monovalent cation, preferably sodium. 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 formula above. They can be prepared readily by reaction between sodium silicate and sodium aluminate, as amply described in the literature. The ratio of surfactants to aluminosilicate (where present) is preferably greater than 5:2, more preferably greater than 3:1.
Alternatively, or additionally to the aluminosilicate builders, phosphate builders may be used. In this art the term 'phosphate' embraces diphosphate, triphosphate, and phosphonate species. Other forms of builder include silicates, such as soluble silicates, metasilicates, layered silicates (e.g. SKS-6 from Hoechst).
Preferably the laundry detergent formulation is a non-phosphate built laundry detergent formulation, i.e., contains less than 1 wt.% of phosphate.

Shading Agent

The laundry composition preferably comprises a blue or violet shading agent in the range from 0.0001 to 0.01 wt.%. The shading agents reduce the perception of damage to many coloured garments and increase whiteness of white garments.
The shading agents are preferably selected from blue and violet dyes of the solvent disperse basic, direct and acid type listed in the colour index (Society of Dyers and Colourists and American Association of Textile Chemists and Colorists 2002).
Preferably a direct violet or direct blue dyes is present. Preferably the dyes are bis-azo, tris-azo dyes or triphendioxazine dye. The carcinogenic benzidene based dyes are not preferred.

Fluorescent Agent

The laundry 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.%. Preferred classes of fluorescer are: Di-styryl biphenyl compounds, e.g. Tinopal (Trade Mark) CBS-X, Di-amine stilbene di-sulphonic acid compounds, e.g. Tinopal DMS pure Xtra and Blankophor (Trade Mark) HRH, and Pyrazoline compounds, e.g. Blankophor SN. Preferred fluorescers are: sodium 2-(4-styryl-3-sulfophenyl)-2H-napthol[1,2-d]trazole, disodium 4,4'-bis{[(4-anilino-6-(N methyl-N-2 hydroxyethyl) amino 1,3,5-triazin-2-yl)]amino}stilbene-2-2' disulfonate, disodium 4,4'-bis{[(4-anilino-6-morpholino-1,3,5-triazin-2-yl)]amino} stilbene-2-2' disulfonate, and disodium 4,4'-bis(2-sulfoslyryl)biphenyl.

Polymers

The laundry composition may comprise one or more polymers. Examples are carboxymethylcellulose, poly(ethylene glycol), poly(vinyl alcohol), polycarboxylates such as polyacrylates, maleic/acrylic acid copolymers, lauryl methacrylate/acrylic acid copolymers, and cationic polysaccharide-based polymers.

Hydrotrobe

A 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, 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. 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%.

Examples

Example 1 Improved perfume deposition

The use of micro-fibrous cellulose to enhance the deposition of perfume particles is shown in this example. Encapsulted perfume particles (perfume encaps) were tested for deposition from laundry formulations with and without micro-fibrous cellulose. Perfume encaps modified by addition of a locust bean gum deposition aid were also tested. The micro-fibrous cellulose used was commercially available from CP Kelco.

Example 1a Synthesis of perfume containing benefit agent particles

Locust bean gum (11.2g) was dissolved in hot (70-80°C) de-ionised water (739.14g) by mixing with a high speed homogeniser (Silverson) at 10,000rpm for 10 minutes until completely solubilised. The solution was then allowed to cool to room temperature under static conditions. It was then transferred to a reaction vessel fitted with an overhead stirrer, condenser, thermocouple (attached to heating mantle) and nitrogen inlet.
Perfume encapsulates (1894.7g, 53.2% solids, 30µm particle size) and vinyl acetate (112g) were added, and the contents purged with nitrogen for 10 minutes, after which point the vessel and contents were left over a nitrogen blanket for the duration of the reaction. The temperature was then raised to 70°C, and aqueous ascorbic acid solution (2.8g in 25g de-ionised water) together with aqueous hydrogen peroxide solution (8g, 35% active) were added to initiate the polymerisation.
After 90 minutes a further an amount of aqueous ascorbic acid solution (0.56g in 5g de-ionised water) and aqueous hydrogen peroxide (1.6g, 35% active) were added to improve the kinetics, and the polymerisation was allowed to continue for a further 30 minutes. The sample was then allowed to cool to room temperature under stirring. The white latex that was obtained consisted of -40% solids. The residual vinyl acetate was in the region of 1000 p.p.m., which equates to a conversion of >99.5 % of the monomer.

Example 1b Deposition of the LBG-PVAc modified encapsulates in the presence of micro-fibrous cellulose

From simulated washing experiments perfume encapsulate deposition in the presence of micro-fibrous cellulose was measured by turbidity as follows:

Two sets of washes were conducted with the unmodified and LBG-PVAc modified perfume encapsulates using a laundry concentrated liquid detergent (Persil (Trademark) "Small and Mighty"). One set was tested with micro-fibrous cellulose present and one set without.

1) Preparation of Wash Solutions

0.05g (500ppm on wash liquor) of unmodified or LBG-PVAc modified perfume encapsulate particles were mixed with laundry concentrated liquid detergents (0.23ml), one without micro-fibrous cellulose and one with (0.125% w/w on detergent) to give a homogeneous dispersion. 100ml of Wirral water were added and the mixture was stirred to evenly disperse and each wash solution was added to the Linitest™ pots. (Washes were done in duplicate for each sample and results averaged). A 5ml aliquot was taken from each and the absorbance at 400nm recorded using a 5cm cuvette. This absorbance value represents 100% particles in the wash solution prior to the simulated wash process.

2) Simulated Wash - Equipment and Procedure:

A section of unfluoresced cotton measuring 20cm by 20cm was placed into each wash liquor and the Linitest pots were sealed.
The Linitest is a laboratory scale washing machine (Ex. Heraeus). The equipment is designed and built to comply with the requirements for international standard test specifications. It is used for small scale detergency and stain removal testing particularly when low liquor to cloth ratios are required.
There are various models of the Linitest commercially available. The model used in this case has a single rotation speed of 40rpm. The carrier is capable of accommodating twelve 500ml steel containers and can be operated at temperatures up to 100°C.
The Linitest comprises a 20 litre tank, control system and drive mechanism. Permanent thermostatically controlled tubular heating elements in the base of the tank heat the bath liquor to the required temperature. The stainless steel construction throughout ensures efficient heat transfer to the specimen containers that are mounted on a rotating horizontal carrier driven by a geared motor. The rotating movement of the carrier 'throws' the liquid from one end of the container to the other in a continuous action. This movement simulates the mechanical washing process and additional mechanical action can be obtained by using steel ball bearings or discs.
The Linitest pots were attached to the Linitester cradle and rotated 45 minutes at 40°C to simulate the main wash.
The cloths were then removed and wrung by hand and a 5ml aliquot of the remaining wash liquor was taken and the absorbance at 400nm measured using a 5cm cuvette as before.
From interpolation of the initial calibration curve, the concentration of the particles remaining the liquor after the wash could be determined and hence the level deposited (wash deposition) on the cloth could be determined by difference.
The Linitest pots were then thoroughly rinsed and the 'wrung' cloths returned to the pots and 100ml of Wirral water was added. The Linitester bath water was drained and the pots attached to the cradle and rotated for 10 minutes at ambient temperature (∼20°C) to simulate a rinse procedure. The clothes were then removed and wrung by hand. A 5ml aliquot of the rinse solution was taken and the absorbance at 400nm determined. As before interpolation of the initial calibration plot allowed the particle concentration removed from the cloth during the rinse to be determined and by comparison to the initial level deposited prior to the rinse, the percentage loss from the cloth could be determined. This procedure was repeated to simulate and determine losses from the second rinse.

The Table below illustrates the results.

Table 1 Deposition of Perfume

Laundry Detergent (Persil Small and Mighty)	Perfume Encaps	Micro-fibrous Cellulose	% Deposition after wash process (main wash and 2 rinses)
Concentrated Liquid	Not Modified	None	10.4 ± 1.7
Concentrated Liquid	LBG-PVAc Shell	None	28.4 ± 1.0
Concentrated Liquid	Not Modified	0.125%	14.8 ± 3.0
Concentrated Liquid	LBG-PVAc Shell	0.125%	34.6 ± 1.4

Thus it can be seen from table 1 that the micro-fibrous cellulose improves the deposition of perfume, both of unmodified perfume encapsulates, and especially also for perfume encapsulates which have had their shell modified with a deposition aid.

Claims

Use of micro-fibrous cellulose to increase the deposition of perfume particles on fabric.
Use according to claim 1, wherein the perfume particles are polymeric core-shell particles.
Use according to claim 1 or claim 2 wherein the perfume particles have a melamine-formaldehyde shell.
Use according to any preceding claim, wherein the perfume particles comprise a deposition aid.
Use according to claim 4, wherein the deposition aid comprises a polysaccharide.
Use according to any preceding claim, wherein the perfume particles are polymeric core-shell perfume encapsulates with a locust bean gum deposition aid.
Use according to any preceding claim, wherein the micro-fibrous cellulose is present at a level of from 0.01 to 2.5 wt.%, preferably 0.01 to 1 wt.%, more preferably from 0.02 to 0.75 wt.%