|Title of Invention||
DETERGENT BAR COMPOSITION
|Abstract||Detergent bar compostions comprising : 1-40% by wt. detergent surfactant of which 2-50% by wt. of the detergent surfactant being a surfactant mixture consisting of a combination of calcium tolerant and calcium intolerant surfactants ; 1-30% by wt. pyrophosphate detergency builder selected from one or more of sodium, potassium and ammonium pyrophosphates, 20-80% by wt. abrasive material.|
|Full Text||FORM -2
THE PATENTS ACT, 1970 (39 of 1970)
(See Section 10)
IMPROVED SOLID DETERGENT BAR COMPOSITION
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.
The invention relates to a solid shaped synergistic detergent composition for cleaning hard surfaces. More particularly the compositions of the invention are useful for cleaning hard surfaces and manual dish washing.
Background and Prior art:
Commercial hard surface cleaning compositions typically comprise one or more surfactants and a plurality of abrasive particles dispersed therein. Combinations of these together with electrolytes are generally used to form a structured system, as is well known in the art.
The conventional cleaning compositions for hard surface cleaning are formulated in the form of solids such as powders, granules, pastes and bars, and in the form of fluid formulations such as liquids and gels.
Cleaning compositions in the solid form are much cheaper than liquids because of low cost packaging and they are very popular forms in developing countries. Amongst the solid forms bars are gaining popularity and growing rapidly in the market of developing countries because of better value delivery. The product dosage in the solid form is easier, it avoids spillage and product application can be better controlled. Cleaning compositions in bar form are economically superior to other product forms and dosage of the product per swipe from the bar is highly controllable. Bars/tablets also do not get easily sogged in the presence of water and the active ingredients are not lost. Bars/tablets require little packaging material and because of the ease of application they are highly preferred over other forms of cleaning products and are especially important for the low cost markets of developing countries.
The physical properties of a detergent bar such as hardness, maintenance of integrity during use and other sensory properties such as amount of lather, feel, perfume etc are important aspects to be considered while formulating the bar.
Among the sensory properties lather has been identified as the key parameter on which consumers grade detergent products. One of the major contributors to loss of lather is the precipitation of the detergent active with the hardness ions present in water. Detergency builders help in binding calcium and builders such as sodium tripolyphosphate (STPP) and sodium carbonate are commonly employed in detergent formulations to protect the detergent surfactant and ensure lather generation during use.
US 4,019,938 (P&G, 1975), discloses detergent compositions utilizing alkali metal pyrophosphates and silicates as detergency builders for effective cleaning in hard water. US 4,116,852, (P&G, 1978), discloses that although pyrophosphates are more efficient builders than tripolyphosphates, pyrophosphates have not been very effective for whiteness maintenance and thus a combination of predominantly pyrophosphate along with a proportion of tripolyphosphate improves the benefit significantly.
IN 171534 (Hindustan lever, 1990), discloses that better building and lather generation can be achieved by using a mixture of phosphates as builders rather than the same weight of pyrophosphate only.
Hard surfaces within the household are kitchenware, cooker tops, kitchen floors and platforms, floors, bathroom surfaces etc. and one encounters different types of soil on these surfaces. The soil generally encountered on kitchenware, cooker tops and the like is of two types i.e. the mobile greasy soil and the tough or difficult to remove soil consisting of dried-on or cooked-on food. The problem becomes more pronounced when the tough soil builds on over a period of time and this requires considerable effort to clean. During the process of dishwashing depletion of lather signals depletion of
active which prompts the consumer to go for a fresh product dose. Hence, lather is the significant attribute deciding product usage rate and overall economy of the product.
Brief description of the invention :
Surprisingly we have now found that in a detergent formulation having a combination of calcium sensitive and calcium tolerant surfactant, pyrophosphate gives a significantly superior benefit in lather generation, thereby improving the economy of the product, when the levels of sodium tripolyphosphate and/or other phosphates are minimal.
This finding is useful for detergent formulations in general, but it is especially useful for detergent bars and more particularly for dish wash bars where the oily soil also has a significant effect in reducing the lather. The incorporation of pyrophosphate, apart from enhancing the lather generation, also improves bar structuring. This considerably helps in reducing the need for other structuring aids to be incorporated and thus increases the economy of manufacture.
N.B. Percentages by weight mentioned below are calculated on the total composition unless specifically mentioned otherwise.
Thus according to the invention there is provided a detergent bar composition comprising :
1-40% by wt. detergent surfactant, of which 2-50% by wt. of the detergent surfactant is calcium tolerant;
1-30% by wt. of pyrophosphate detergency builder selected from one or more of sodium, potassium and ammonium pyrophosphates,
30-80% by wt. of abrasive material
Detailed Description of the invention:
The composition may contain limited amounts other phosphate detergency builder than pyrophosphate, however, it is preferred that the level of tripolyphosphate salts is not greater than 1% by wt. of the total amount of phosphate detergency builder. Furthermore, it is preferred that the amount of other phosphates than pyrophosphate and tripolyphosphate is not more than 15% wt. of total amount of phosphate detergency builder, even more preferably not more than 5% wt. of total phosphate builder.
Alkaline silicate does not form an essential part of the invention and when present it is at a level of 1% wt. or below and the Si02:M20 molar ratio is between 2:1 and 1:1, wherein M is sodium or potassium or a mixture thereof.
The invention is described in greater detail below with reference to compositions for cleaning kitchen ware and kitchen surfaces, but is not restricted to cleaning of these and can be applied to other hard surfaces or to fabric.
The composition according to the invention will essentially comprise a surfactant mixture which is a combination of calcium-tolerant and calcium-intolerant surfactants generally chosen from alkali or alkaline earth metal or ammonium or alkanolamine salts of anionic surfactants and/or of nonionic, amphoteric or zwitterionic surfactants.
Calcium tolerant surfactants:
The calcium tolerant surfactants are those which do not form precipitates of their calcium salts in hard water. Certain synthetic anionic surfactants and most nonionic surfactants are calcium tolerant. Among the anionic surfactants sulphonation products of /olefins 'and alkyl ether sulphates are specifically preferred calcium tolerant surfactants. The preferred nonionics can be broadly described as compounds produced by the condensation of alkylene oxide groups, which are hydrophilic in nature, with an
organic hydrophobic compound which may be aliphatic or alkyl aromatic in nature. The length of the hydrophilic or polyoxyalkylene radical which is condensed with any particular hydrophobic group can be readily adjusted to yield a water-soluble compound having the desired balance between hydrophilic and hydrophobic elements.
Particular examples include the condensation product of aliphatic alcohols having from 8 to 22 carbon atoms in either straight or branched chain configuration with ethylene oxide, such as a coconut oil ethylene oxide condensate having from 2 to 15 moles of ethylene oxide per mole of coconut alcohol; condensates of alkylphenols whose alkyl group contains from 6 to 12 carbon atoms with 5 to 25 moles of ethylene oxide per mole of alkylphenol; condensates of the reaction product of ethylenediamine and propylene oxide with ethylene oxide, the condensate containing from 40 to 80% of polyoxyethylene radicals by weight and having a molecular weight of from 5,000 to 11,000; tertiary amine oxides of structure R3NO, where one group R is an alkyl group of 8 to 18 carbon atoms and the others are each methyl, ethyl or hydroxyethyl groups, for instance dimethyldodecylamine oxide; tertiary phosphine oxides of structure R3PO, where one group R is an alkyl group of from 10 to 18 carbon atoms, and the others are each alkyl or hydroxyalkyl groups of 1 to 3 carbon atoms, for instance dimethyl-dodecylphosphine oxide; and dialkyl sulphoxides of structure R2SO where the group R is an alkyl group of from 10 to 18 carbon atoms and the other is methyl or ethyl, for instance methyl-tetradecyl sulphoxide; fatty acid alkylolamides; alkylene oxide condensates of fatty acid alkylolamides and alkyl mercaptans. The nonionic can also be selected from a range of alkyl poly glycosides.
Suitable anionic surfactants are water soluble salts of organic sulphuric reaction products having in the molecular structure an alkyl radical containing from 8 to 22 carbon atoms, and a radical chosen from sulphonic acid or sulphuric acid ester radicals and mixtures thereof.
The preferred water-soluble synthetic anionic surfactants are higher alkyl aromatic sulphonates and mixtures with olefin sulphonates and higher alkyl sulphates, and the higher fatty acid monoglyceride sulphates having an alkanolamine counter ion. The more preferred anionic surfactants are higher alkyl aromatic sulphonates such as higher alkylbenzene sulphonates containing from 6 to 20 carbon atoms in the alkyl group in a straight or branched chain, particular examples of which are higher alkylbenzene sulphonates or of higher alkyl-toluene, xylene or phenol sulphonates, alkylnaphthalene sulphonates, diamylnaphthalene sulphonate, and dinonylnaphthalene sulphonate having an alkanolamine counter ion.,/
The suitable alkanolamine counter ions of the anionic surfactants for use in the compositions of the present invention can be mono- or poly-functional as regards the amine and hydroxy moieties. Preferred alkanolamines are generally of the formula H2N-R1-OH where R1 is a linear or branched alkyl chain having 2-6 carbons. Preferred alkanolamines include 2-amino-2-methyl-1-propanol, amino-methyl-propanediol, TRIS (hydroxy methyl) propane-diol, amino, mono- di- and tri- ethanolamine, mono- di- and tri-isopropanolamine, dimethyl-, diethyl- or dibutyl-ethanolamine, and mixtures thereof.
Particularly preferred alkanolamine salts of anionic surfactants are 2-amino-2-methyl-1-propanol (AMP) and monoethanolamine (MEA) salts of linear alkylbenzene sulphonic acid.
The total amount of synthetic anionic surfactant to be employed in the detergent compositions of this invention will generally be up to 35% wt and more preferably from 10 to 25% wt of the composition.
It is also possible optionally to include amphoteric or zwitterionic surfactants in the compositions according to the invention.
Suitable amphoteric surfactants that optionally can be employed are derivatives of aliphatic secondary and tertiary amines containing an alkyl group of 8 to 18 carbon atoms and an aliphatic radical substituted by an anionic water-solubilising group, for instance sodium 3-dodecylamino-propionate, sodium 3-dodecylaminopropane sulphonate and sodium N-2-hydroxydodecyl-N-methyltaurate. Suitable zwitterionic surfactants that optionally can be employed are derivatives of aliphatic quaternary ammonium, sulphonium and phosphonium compounds having an aliphatic radical of from 8 to 18 carbon atoms and an aliphatic radical substituted by an anionic water-solubilising group, for instance 3-(N-N-dimethyl-N-hexadecylammonium) propane-1-sulphonate betaine, 3-(dodecylmethyl sulphonium) propane-1 -sulphonate betaine and 3-(cetylmethylphosphonium) ethane sulphonate betaine.
Further examples of suitable surfactants are compounds commonly used as surface-active agents given in the well-known textbooks: "Surface Active Agents" Vol.1, by Schwartz & Perry, Interscience 1949; Vol.2 by Schwartz, Perry & Berch, Interscience 1958; the current edition of "McCutcheon's Emulsifiers and Detergents" published by Manufacturing Confectioners Company, and "Tenside-Taschenbuch", H. Stache, 2nd Edn., Carl Hauser Verlag, 1981.
As outlined above the compositions according to the invention comprise phosphate detergency builder which predominantly comprises pyrophosphate salts in an amount of 1-30% of the total composition. It is preferred that the tripolyphosphate level, if present, is maintained at or below 1% wt. of the phosphate builder. It is also preferred that other phosphates, if present, are maintained at levels at or below 15% wt. of the phosphate builder, more preferably below 5%.
The pyrophosphate may be selected from sodium, potassium or ammonium pyrophosphates. It is preferred that the level of the pyrophosphate is 2 - 20% by weight of the composition.
A particulate abrasive phase and additional particulates form at least 20% by weight of the composition. Preferably, the particulate phase comprises a particulate abrasive that is insoluble in water. In the alternative, the abrasive may be soluble and present in such excess to any water present in the composition that the solubility of the abrasive in the aqueous phase is exceeded and consequently solid abrasive exists in the composition.
Suitable abrasives are selected from, particulate Zeolites, calcites, dolomites, feldspar,
silica's, silicates, other carbonates, alumina's, bicarbonates, borates, sulphates and
polymeric materials such as polyethylene. Preferred abrasives have Moh hardness 2-7 -6 although higher hardness abrasives can be employed for specialist applications. Preferred average particle sizes for the abrasive fall in the range 0.5-400 microns, preferably 10-200 microns.
Optional ingredients 2,
The composition according to the invention can contain other ingredients that aid in their cleaning performance. For example, the composition can contain detergent builders other than the phosphate builder, such as nitrilotriacetates, polycarboxylates, citrates, dicarboxylic acids, zeolites and mixtures thereof. Such builders can additionally function as abrasives if present in an amount in excess of their solubility in water. In general, a builder other than phosphate, when employed, preferably will form from 0.1 to 25% by weight of the composition.
Compositions according to the invention can also contain, in addition to the ingredients already mentioned, various other optional ingredients such as solvents, structuring agents, colourants, whiteners, soil suspending agents, detersive enzymes, perfume and preservatives.
Preferred structuring agents are known in the art and include natural or modified polysaccharides, such as sodium carboxymethyl-cellulose, other chemically modified cellulose materials, xanthan gum and other non-flocculating structuring agents.
The synergistic solid shaped cleaning compositions according to the invention are prepared by mixing the essential and optional ingredients in the desired amounts in a conventional manner.
The invention will now be illustrated with respect to the following non-limiting examples.
Detergent bar compositions according to the invention and control compositions are as described in Tables 1 and 2 They were prepared by a conventional manufacturing method whereby the ingredients were added sequentially into a mixer under continuous mixing and then extruded into bars. The bars thus prepared were analyzed for lather generation.
i. Method for measuring lather:
Aqueous solutions of 6.25g/l of the different bars of Ex. 1-5 described in tables 1 and 2, in water 6f hardness 30° FH were prepared? 200 ml of the solutions were taken in graduated glass cylinders, which had an internal volume of 31and a stop cock at the bottom. The cylinders were then shaken vigorously, for a period of 10 seconds with a fixed number of oscillations/time. Lather was generated during this shaking. The
cylinders were then mounted on a clamp stand and the liquid at the bottom was carefully drained out of the flask with the stop cock at the bottom. The volume of lather in the cylinders was recorded 1 minute after shaking was stopped. The amount of lather generated in ml is presented in tables.
The other bar properties such as cleaning efficiency, bar hardness and other sensory properties such as feel, perfume etc were on par with the control formulations.
ii. The effect of Sodium tripolyphosphate
For measuring the effect of sodium tripolyphosphate on the bar properties the compositions of example 2 (according to the invention) and examples 1 and 3 (control) as outlined in Table 1 below were prepared and measured as described above.
Components (% wt.) Ex.1 Ex.2 Ex.3
Sodium alkylbenzene sulphonate (Ca sensitive) 10 9 9
Sodium alkylether sulphate (Ca tolerant) 0 1 1
TSPP 6 6 6
STPP 0 0 1
Abrasives+Fillers 80 80 80
Water to 100 to 100 to 100
Lather volume (ml) 800 1600 1430
The data presented in Table 1 show that when the surfactant mix is a combination of calcium sensitive and calcium tolerant surfactant use of trisodium pyrophosphate as the builder (Ex.2) gives significantly higher amounts of lather. This effect is not seen if the calcium tolerant surfactant is not incorporated (Ex. 1) or when sodium tripolyphosphate
is incorporation at 1% by weight of the composition which is actually equivalent to 14% by weight of the total phosphate builder (Ex 3).
iii. Effect of alkaline silicate on the bar properties:
The detergent bar compositions according to the invention (Example 4) where the level of alkaline silicate was maintained below 1% and the respective control composition (Example 5) are as described in Table 2 and were prepared as described above.
Components (% wt.) Ex 4 Ex 5
Sodium alkylbenzene sulphonate (Ca sensitive) 9 9
Sodium alkylether sulphate (Ca tolerant) 1 1
TSPP 7 7
STPP 0 0
Alkaline silicate 0 2
Soda 2 2
Abrasives 80 80
Water to 100 to 100
Lather volume (ml) 1500 1350
The data presented in Table 2 show that if the alkaline silicate is at a level greater than 1% then a drop in lather is observed (Ex. 5).
1. Detergent bar compostions comprising :
1-40% by wt. detergent surfactant of which 2-50% by wt. of the detergent surfactant being a surfactant mixture consisting of a combination of calcium tolerant and calcium intolerant surfactants ;
1-30% by wt. pyrophosphate detergency builder selected from one or more of sodium, potassium and ammonium pyrophosphates,
20-80% by wt. abrasive material.
2. Detergent bar compositions as claimed in claim 1 wherein the phosphate detergency builder comprises at most 1% by wt. of the total phosphate builder of tripolyphosphate salts.
3. Detergent bar compositions as claimed in claim 1 or 2 wherein the phosphate detergency builder comprises at most 15% by wt. of the total phosphate builder of other phosphates than pyrophosphate and tripolyphosphate.
4. Detergent bar compositions as claimed in claim 3 wherein the amount of other phosphates is at most 5% by wt. of the total phosphate builder.
5. Detergent bar compositions as claimed in claim 1-4 wherein the amount of pyrophosphate is 2-20% by wt. of the composition.
6. Detergent bar compositions as claimed in claim 1-5 comprising 0-1% of alkaline silicate wherein the Si02:M20 molar ratio is between 2:1 and 1:1.
7. Detergent bar compositions as claimed in claim 1-6 wherein the calcium tolerant surfactants are nonionic surfactants and/or anionic surfactants chosen from olefin sulphonation products and alkyl ether sulphates.
8. Detergent bar compositions as claimed in claim 1-7 wherein the calcium intolerant surfactants comprise higher alkyl aromatic sulphonate.
9. Detergent bar compositions as claimed in claim 8 wherein the alkyl aromatic sulphonate is an alkylbenzene sulphonate.
10. Detergent bar compositions as claimed in claim 1-9 wherein the total amount of synthetic anionic surfactant is up to 35% wt. of the composition
Dated this 20th day of September,2002
Dr.Sanchita Ganguli Of S.MAJUMDAR & CO. Applicant's Agents
|Indian Patent Application Number||927/MUM/2001|
|PG Journal Number||24/2007|
|Date of Filing||26-Sep-2001|
|Name of Patentee||HINDUSTAN UNILEVER LIMITED|
|Applicant Address||165/166, BACKBAY RECLAMATION, MUMBAI - 400 020,|
|PCT International Classification Number||C 11 D 17/00|
|PCT International Application Number||N/A|
|PCT International Filing date|