|Title of Invention||
LAUNDRY DETERGENT COMPOSITIONS
|Abstract||A POWDER LAUNDRY DETERGENT COMPOSITION A powder laundry detergent composition comprising (a) more than 10wt% of a calcium-tolerant anionic surfactant system; (b) from 0.1% to 10%, preferably from 0.5% to 10%, more preferably from 1% to 10% by weight of a strong builder system selected from phosphate builders and aluminosilicate builders and mixtures thereof; and (c) the balance, if any, being other detergent ingredients wherein said composition comprises less than 35wt%, preferably less than 25wt%, more preferably less than 15wt% of non-functional non-alkaline water soluble inorganic salt.|
|Full Text||FORM -2
THE PATENTS ACT, 1970 (39 of 1970)
(See Section 10)
HINDUSTAN LEVER LIMITED, a company incorporated under the Indian Companies Act, 1913 and having its registered office at Hindustan Lever House, 165/166, Backbay Reclamation, Mumbai -400 020, Maharashtra, India
The following specification particularly describes the nature of the invention and the manner in which it is to be performed.
TECHNICAL FIELD v
' ^ v V v e -v
The present invention relates to a laundry detergent composition which may for example, be formulated as a particulate, tablet or liquid composition.
BACKGROUND TO THE INVENTION
Conventional laundry detergent powders intended for the handwash contain a substantial level of anionic surfactant, most usually alkylbenzene sulphonate. Anionic surfactants are ideally suited to the handwash because they combine excellent detergency on a wide range of soils with high foaming.
However, event at high levels of anionic surfactant, for handwashing, the oily soil removal performance of such products is in need of improvement.
magnesium-insensitive surfactant (for example, alkyl ether sulphate, ethoxylated "
nonionic surfactant, amine oxide), from 13 to 40 wt% of sodium silicate, and from 5 to
50 wt% of a magnesium-selective detergency builder (for example, zeolite, sodium
citrate, nitrilotriacetate, or calcite/carbonate).
JP-A-09 087 690 discloses a high-bulk-density granular detergent composition for \ *
WO-A-97/43366 relates to detergent composition comprising from 0.5% to 60% by weight an anionic surfactant and from 0.01% to 30% by weight of a cationic surfactant. In the exemplified compositions in this document, the level of anionic surfactant is typically from about 10% to 15% by weight of the composition and the amount of cationic surfactant is from about 1% to 4% by weight. In some examples, the anionic surfactant component contains small amounts of an alkyl ether sulphate surfactant, typically at from 0.76% to 2.5% by weight of the total composition.
Compositions with small amounts of alkyl ether sulphate anionic surfactant (up to -1.75wt%) and in one case, a low amount of zeolite (1.5wt%) are disclosed in WO-A-98/01521. However, these compositions are spray-dried and therefore have high amounts of sodium sulphate which is a non-alkaline non-functional water-soluble salt (electrolyte).
Other spray-dried compositions with high levels of sodium sulphate and containing alpha-olefin sulphate anionic surfactant, together with 12 or 15 wt% zeolite builder are disclosed in JP-A-62 218499.
WO-A-00/40682 discloses compositions comprising more than 40% of an anionic surfactant system at least some comprising a calcium tolerant surfactant such as an alpha-olefin sulphonate or alkyl ether sulphate. The examples with calcium tolerant surfactant either contain no phosphate or aluminosilicate builder or else a very high level of phosphate.
Our UK Patent Application No. 9925961.6 also discloses compositions with 5-30 wt% of alpha-olefin sulphonate. These are all based on a calcite/carbonate builder system.
Other compositions containing calcium tolerant surfactants are disclosed in US-A-6 010 996, GB-A-2 309 706, US-A-5 415 812, US-A-4 265 777 and US-A-4 970 017.
The co-pending application No.l204/MUM/2001 dated December 24, 2001 teaches a laundry detergent composition comprising (a) at least 5wt% of a calcium-tolerant non-soap surfactant system comprising an alpha-olefin sulphonate; (b) at least 0.1% of a cationic surfactant system in a weight ratio of (a) : ( b) of from 17:3 to 9 :10 preferably from 3:1 to 1:1 and (c) the balance, if any, being other minor ingredients
There remains a need, fulfilled by the present invention, for compositions which contain a strong builder, namely a phosphate or aluminosilicate builder, but at lower levels, yet which are still robust across a wide range of water hardness.
DEFINITION OF THE INVENTION A detergent composition comprising :
(a) more than 10wt% of a calcium-tolerant non-soap anionic surfactant system.
(b) From 0.1% to 10%, preferably from 0.5% to 10%, more preferably from 1% to 10% by weight of a strong builder system selected from phosphate builders and aluminosilicate builders and mixtures thereof; and
(c) The balance, if any, being other detergent ingredients wherein said composition comprises less than 35wt%, preferably less than 25wt%, more preferably less than 15wt% of non-functional non-alkaline water soluble inorganic salt.
DETAILED DESCRIPTION OF THE INVENTION
The composition of the invention is based on mixed calcium tolerant anionic surfactant systems,
plus moderate amounts of phosphate and/or aluminosilicate builder.
The anionic surfactant system
The composition of the invention contains more than 10wt% of calcium tolerant anionic
surfactant. Typically, the upper level of this calcium tolerant anionic surfactant system will be
75wt%. However, preferably, the anionic surfactant system is present at from 15wt% to 65%,
more preferably from 20wt% to 60wt%, especially from 30wt% to 50wt% based on the weight
of the total composition.
The calcium ion stability of anionic surfactants can be measured by the modified Hart method (Witkes, etal. J. Ind. End. Chem. 29, 1234-1239 (1937)), carried in microtiter plates. The surfactant solution is titrated with a calcium ion solution. The onset of turbidity indicates the start of formation of insoluble calcium precipitates after a minute of shaking at room temperature.
As referred to herein, a "calcium tolerant" surfactant is one that does not precipitate at a surfactant concentration of 0.4 g/L (and at a ionic strength of a 0.040 M 1:1 salt solution at) with a calcium concentration up to 20° FH (French hardness degrees), i.e. 200 ppm calcium.
The preferred non-soap calcium tolerant anionic surfactant for use in the compositions of the present invention is alpha-olefin sulphonate.
Advantageously alkyl ether sulphate (another non-soap calcium tolerant material) may be present, preferably as a co-surfactant with the alpha-olefin sulphonate, in an amount less that that of the latter.
A preferred surfactant system comprises alpha-olefin sulphonate and alkyl ether sulphate in a weight ratio of from 5:1 to 15:1.
Other calcium-tolerant anionic surfactants that may be used alone or in combination with these or other calcium-tolerant anionics are alkyl ethoxy carboxylate surfactants (for example, Neodox (Trade Mark) ex Shell), fatty acid ester sulphonates (for example, FAES MC-48 and ML-40 ex Stepan), alkyl xylene sulphonates, dialkyi sulphosuccinates, fatty acid ester sulphonates, alkyl amide sulphates, sorpholipids, alkyl glycoside sulphates and alkali metal (e.g. sodium) salts of saturated or unsaturated fatty acids.
More than one other anionic surfactants may also be present. These may for example be selected from one or more of alkylbenzene sulphonates, primary and secondary alkyl sulphates.
When it is desired to avoid the calcium intolerance of alkylbenzene sulphonate surfactant altogether, then the anionic surfactant system may comprise (preferably at a level of 70 wt% or more of the total anionic surfactant) or consist only of one or more calcium-tolerant non-soap anionic surfactants.
The Strong Builder System
The strong builder system is selected from phosphate builders, aluminosilicate builders and mixtures thereof.. The total amount of this strong builder system is from 0.1% to 10%, preferably from 0.5% to 10%, more preferably from 1% to 10% by weight of the composition. However, one or more weak builders such as calcite/carbonate, citrate or polymer builders may also be present.
The phosphate builder (if present) may for example be selected from alkali metal, preferably sodium, pyrophosphate, orthophosphate and tripolyphosphate, and mixtures thereof.
The aluminosilicate may be, for example, selected from one or more crystalline and amorphous aluminosilicates, for example, zeolites as disclosed in GB 1 473 201 (Henkel), amorphous aluminosilicates as disclosed in GB 1 473 202 (Henkel) and mixed crystalline/amorphous aluminosilicates as disclosed in GB 1 470 250 (Procter & Gamble); and layered silicates as disclosed in EP 164 514B (Hoechst
The alkali metal aluminosilicate may be either crystalline or amorphous or mixtures thereof, having the general formula: 0.8-1.5 Na20. AI203. 0.8-6 Si02.
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 Si02 units (in the formula above). Both the amorphous and the crystalline materials can be prepared readily by reaction between sodium silicate and sodium aluminate, as amply described in the literature. Suitable crystalline sodium aluminosilicate ion-exchange detergency builders are described, for example, in GB 1 429
143 (Procter & Gamble). The preferred sodium aluminosilicates of this type are the well-known commercially available zeolites A and X, and mixtures thereof.
The zeolite may be the commercially available zeolite 4A now widely used in laundry detergent powders. However, according to a preferred embodiment of the invention, the zeolite builder incorporated in the compositions of the invention is maximum aluminium zeolite P (zeolite MAP) as described and claimed in EP 384 070A (Unilever). Zeolite MAP is defined as an alkali metal aluminosilicate of the zeolite P type having a silicon to aluminium ratio not exceeding 1.33, preferably within the range of from 0.90 to 1.33, and more preferably within the range of from 0.90 to 1.20.
Especially preferred is zeolite MAP having a silicon to aluminium ratio not exceeding 1.07, more preferably about 1.00. The calcium binding capacity of zeolite MAP is generally at least 150 mg CaO per g of anhydrous material.
The compositions of the invention must contain less than 35wt%, preferably less than 25wt%, more preferably less than 15wt% of non-functional non-alkaline water soluble inorganic salts
Cationic surfactant systems
The compositions of the present invention optionally contain at least 0.1% by weight of the cationic surfactant system. Typically, the cationic surfactant system may be present at up to 15 wt% of the total composition. However, it preferably is present at from 0.5 wt% to 5 wt% at the composition.
Preferred cationic surfactant types include those having the formula:
R1 = is a hydrophobic group (preferably) C12 -14 alkyl, or derived from Coco;
R2, R3 or R4 are independently hydroxyethyl, hydroxypropyl or C1-4 alkyl (e.g. Me, Et)
X- is a solubilising cation, preferably CI-, Br- or MeS04"
Specific examples are:
(i) alkyl hydroxyethyl dimethylammonium chloride HoeS3996 (now sold as Praepagen HY) (ex Clariant, prev. Hoechst)
R2. R3. R4
2 methyl, 1 hydroxyethyl
(ii) Alkyl dihydroxyethyl methylammonium chloride Bis-AQA types (ex Clariant) s.g. Ethoquad C12 type (AKZO-Nobel)
1 methyl, 2-hydroxyethyl
(iii) alkyl trimethyl ammonium chloride Arquad types (eg. Arquad 333W)
The definition of cationic surfactants also include QMEA (quatemised monoethanolamine) or QTEA (quatemised triethanolamine). Quatemisation can arise as the result of neutralisation in situ of MEA or TEA by a surfactant acid (i.e. LAS acid, fatty acid, paraffin sulphonic acid = SAS acid, etc):
RJ R2, R3, R4
iv) mono-hydroxyethyl H 2 H, 1
ammonium chloride Quatemised MEA hydroxyethyl
(v) tri-hydroxyethyl 1-hydroxyethyl 1 H, 2-hydroxyethyl
ammonium chloride Quatemised TEA
The physical form of the amines is water-like liquid. They could be either applied in the slurry for powder making (as an alkali replacing caustic soda partly) or in a post-dosed granule adjunct and present as a counter-ion after the neutralisation of a surfactant acid.
(vi). APA Quats: Alkyl amido-N-propylene dimethyl (quartemary-)ammonium chloride
(alkyl-CON(X)-(CH2)3NH+(CH3)2 CI- where X = H or Me, Et, Pr or higher)
APA Quats C12-C14-CON(X)(CH2)3 2 methyl
(vii) Alcohol triethoxy dimethyl ammonium chloride (alkyl (EO)n N+(CH3)3 CI-, where nisi -10
(viii) Esterquats: Mono or di (cocoyl-ethylene) hydroxyethyl methylammonium chloride (Cocoyl(CH2)2N+(CH3)(CH2CH20H)CH3S04-
(viii) Benzyldimethyl cocoalkyl ammonium chlorides (eg R(CH3)2N+CH2C6H5 CI-, etc.) ex AKZO-Nobel e.g. Arquad DMCB-80, DMHTB-75 Arquad M2HTB-80)
(ix) Cocobenzyl-(ethoxylated (2) -ammonium chloride (e.g. Ethoquad C12/B)
(x) Ethoxylated Quaternary Salts (Monoalkyl ethoxylates) i.e. monoalkyl methyl [ethoxylated (n)] ammonium chloride
- e.g. Ethoquat 18/12, i.e. octadecy I methyl [ethoxylated (2)], Ethoquad 18/25, Ethoquad C/12, C/25, Ethoquad 0/12, i.e. Oleylmethyl [ethoxylated (2)], ethoquad C/12 nitrate, i.e. cocomethyl [ethoxylated (2)] ammonium nitrate, Ethoquad T/12 i.e. Tallowalkylmethyl [ethoxylated (2)]-ammonium chloride.
Optional other surfactants
If desired, nonionic surfactant may be included in order to control foam. The amount of these materials, in total, should not generally exceed 10 wt% and preferably will not exceed 5 wt%.
Preferred nonionic surfactants are the C10-C16 aliphatic alcohols having an average degree of ethoxylation of from 1 to 10, more preferably the C12-C15 alcohols having an average degree of ethoxylation of from 2 to 8.
Laundry wash compositions according to the invention may also suitably contain a bleach system. Fabric washing compositions may desirably contain peroxy bleach compounds, for example, inorganic persalts or organic peroxyacids, capable of yielding hydrogen peroxide in aqueous solution.
Suitable peroxy bleach compounds include organic peroxides such as urea peroxide, and j
inorganic persalts such as the alkali metal perborates, percarbonates, perphosphates, persilicates and persulphates. Preferred inorganic persalts are sodium perborate monohydrate and tetrahydrate, and sodium percarbonate. ;
Especially preferred is sodium percarbonate having a protective coating against destabilisation by moisture. Sodium percarbonate having a protective coating comprising sodium metaborate and sodium silicate is disclosed in GB-A-2 123 044.
The peroxy bleach compound is suitably present in an amount of from 0.1 to 35 wt%, preferably from 0.5 to 25 wt%. The peroxy bleach compound may be used in conjunction with a bleach activator (bleach precursor) to improve bleaching action at low wash temperatures. The bleach precursor is suitably present in an amount of from 0.1 to 8 wt%, preferably from 0.5 to 5 wt%.
Preferred bleach precursors are peroxycarboxylic acid precursors, more especially peracetic acid precursors and pemoanoic acid precursors. Especially preferred bleach precursors suitable for use in the present invention are N.N.N'.N'.-tetracetyl ethylenediamine (TAED) and sodium noanoyloxybenzene sulphonate (SNOBS). The novel quaternary ammonium and phosphonium bleach precursors disclosed in US 4 751 015 and US-A-4 818 426 and EP-A-402 971, and the cationic bleach precursors disclosed in EP-A-284 292 and EP-A-303 520 are also of interest.
The bleach system can be either supplemented with or replaced by a peroxyacid. examples of such peracids can be found in US-A- 4 686 063 and US-A- 5 397 501. A preferred example is the imido peroxycarboxylic class of peracids described in EP-A-325 288, EP-A-349 940, DE-A-382 3172 and EP-A-325 289. A particularly preferred example is phtalimido peroxy caproic acid (PAP). Such peracids are suitably present at 0.1 -12%, preferably 0.5 -10%.
A bleach stabiliser (transition metal sequestrant) may also be present. Suitable bleach stabilisers include ethylenediamine tetra-acetate (EDTA), the polyphosphonates such as Dequest (Trade Mark) and non-phosphate stabilisers such as EDDS (ethylene diamine di-succinic acid). These bleach stabilisers are also useful for stain removal especially in products containing low levels of bleaching species or no bleaching species.
An especially preferred bleach system comprises a peroxy bleach compound (preferably sodium percarbonate optionally together with a bleach activator), and a transition metal bleach catalyst as described and claimed in EP-A-458 397, EP-A-458 398 and EP-A-509 787.
Laundry wash compositions according to the invention may also contain one or more enzyme(s). Suitable enzymes include the proteases, amylases, cellulases, oxidases, peroxidases and lipases usable for incorporation in detergent compositions. Preferred proteolytic enzymes (proteases) are, catalytically active protein materials which degrade or alter protein types of stains when present as in fabric stains in a hydrolysis reaction. They may be of any suitable origin, such as vegetable, animal, bacterial or yeast origin.
Proteolytic enzymes or proteases of various qualities and origins and having activity in various pH ranges of from 4-12 are available and can be used in the instant invention. Examples of suitable proteolytic enzymes are the subtilisins which are obtained from particular strains of B. Subtilis B. licheniformis, such as the commercially available subtilisins Maxatase (Trade Mark), as supplied by Gist Brocades N.V., Delft, Holland, and Alcalase (Trade Mark), as supplied by Novo Industri A/S, Copenhagen, Denmark.
Particularly suitable is a protease obtained from a strain of Bacillus having maximum activity throughout the pH range of 8-12, being commercially available, e.g. from Novo Industri A/S under the registered trade-names Esperase (Trade Mark) and Savinase (Trade-Mark). The preparation of these and analogous enzymes is described in GB 1 243 785. Other commercial proteases are Kazusase (Trade Mark obtainable from Showa-Denko of Japan), Optimase (Trade Mark from Miles Kali-Chemie, Hannover, West Germany), and Superase (Trade Mark obtainable from Pfizer of U.S.A.).
Detergency enzymes are commonly employed in granular form in amounts of from about 0.1 to about 3.0 wt%. However, any suitable physical form of enzyme may be used.
Other Optional Minor Ingredients
The compositions of the invention may contain alkali metal, preferably sodium carbonate, in order to increase detergency and ease processing. Sodium carbonate may suitably be present in amounts ranging from 1 to 60 wt%, preferably from 2 to 40 wt%. However, compositions containing little or no sodium carbonate are also within the scope of the invention.
Powder flow may be improved by the incorporation of a small amount of a powder structurant, for example, a fatty acid (or fatty acid soap), a sugar, an acrylate or acrylate/maleate copolymer, or sodium silicate. One preferred powder structurant is fatty acid soap, suitably present in an amount of from 1 to 5 wt%.
Yet other materials that may be present in detergent compositions of the invention include sodium silicate; antiredeposition agents such as cellulosic polymers; inorganic salts such as sodium sulphate; lather control agents or lather boosters as appropriate; dyes; coloured speckles; perfumes; foam controllers; fluorescers and decoupling polymers. This list is not intended to be exhaustive.
Preparation of the compositions
The compositions of the invention may be prepared by any suitable process.
The choice of processing route may be in part dictated by the stability or heat-sensitivity of the surfactants involved, and the form in which they are available.
For example, alpha-olefin sulphonate is robust, and is available in powder, paste and solution form.
Alkyl ether sulphate is more sensitive to heat, is susceptible to hydrolysis, and is available as concentrated (e.g. about 70% active matter) aqueous paste, and as more dilute (e.g. 28.5 wt%) solution.
In all cases, ingredients such as enzymes, bleach ingredients, sequestrants, polymers and perfumes which are traditionally added separately (e.g. enzymes postdosed as granules, perfumes sprayed on) may be added after the processing steps outlined below.
Suitable processes include:
(1) drum drying of principal ingredients, optionally followed by granulation or postdosing of additional ingredients;
(2) non-tower granulation of all ingredients in a high-speed mixer/granulator, for example, a Fukae (Trade Mark) FS series mixer, preferably with at least one surfactant in paste form so that the water in the surfactant paste can act as a binder;
(3) non-tower granulation in a high speed/moderate speed granulator combination, thin film flash drier/evaporator or fluid bed granulator.
WE CLAIM :
1. A powder laundry detergent composition comprising:
(a) more than 10 wt % of a calcium-tolerant non-soap anionic surfactant system; wherein the calcium-tolerant non-soap anionic surfactant comprises alpha olefin sulphonate and alkyl ether sulphate in a weight ratio of 5:1 to 15:1
(b) from 0.1% to 10% by weight of a strong builder system selected from phosphate builders and aluminosilicate builders and mixtures thereof; and
(c) a laundry detergent ingredient selected from the group consisting of fluorescer and anti-redeposition agent;
(d) the balance, if any, being other detergent ingredients wherein said composition comprises less than 35 wt % of non-functional non-alkaline water soluble inorganic salt.
2. A detergent composition as claimed in claim 1, further comprising one or more non-calcium tolerant anionic surfactants.
3. A detergent composition as claimed in claim 2, comprising from 5% to 70% by weight of non-calcium tolerant surfactant.
4. A detergent composition as claimed in claim 2, wherein the calcium-tolerant non-soap anionic surfactant comprises alpha-olefin sulphonate.
5.' A detergent composition as claimed in claim 1, comprising less than 1% by weight of sulphate anionic surfactant.
6. A detergent composition as claimed in claim 4, wherein the calcium-tolerant non-soap anionic surfactant comprises alpha-olefin sulphonate and alkyl ether sulphate.
7. A detergent composition as claimed in claim 1, comprising at least 0.5 wt % of a cationic surfactant system.
8. A detergent composition as claimed in claim 7, comprising from 0.5% to 5% by weight of the cationic surfactant system.
9. A detergent composition as claimed in claim 7, wherein the weight ratio of component (a) to the cationic surfactant systems is from 3:1 to 9:10.
10. A detergent composition as claimed in claim 7, wherein the cationic surfactant system
comprises one or more cationic surfactants selected from those of formula:
R1 R2 R3 R4 N+ X" wherein
R1 is a hydrophobic group;
R2 R3 and R4 are independently selected from hydroxyethyl, hydroxy propyl and Ci13alkyl;
X" is a solubilising cation.
11. A powder detergent composition having the composition of claim 1, wherein component (a) and the cationic surfactant system are substantially contained in separate granules, each respectively excluding the other component.
12. The laundry composition as claimed in claim 1 wherein the composition comprises from 0.5% to 10% of the strong builder system.
13. The laundry composition as claimed in claim 1 wherein the composition comprises from 1% to 10% of the strong builder system.
14. The composition as claimed in claim 3 wherein the composition comprises from 10% to 50% by weight of non calcium tolerant surfactant.
15. The composition as claimed in claim 5 wherein the composition comprises less than 0.1% of the sulphate anionic surfactant.
16. The composition as claimed in claim 5 whereinthe composition comprises 0% of the sulphate anionic surfactant.
Dated this 24th day of December 2001
Dr.Sanchita Ganguli Of S. MAJUMDAR & CO. Applicant's Agent
|Indian Patent Application Number||1205/MUM/2001|
|PG Journal Number||41/2007|
|Date of Filing||24-Dec-2001|
|Name of Patentee||HINDUSTAN LEVER LIMITED|
|Applicant Address||HINDUSTAN LEVER HOUSE, 165/166, BACKBAY RECLAMATION, MUMBAI-400 020, MAHARASHTRA, INDIA.|
|PCT International Classification Number||N/A|
|PCT International Application Number||N/A|
|PCT International Filing date|