|Title of Invention||
IMPROVED DETERGENT COMPOSITION
|Abstract||A synergistic abrasive cleaning composition comprising anionic surfactant and an abrasive wherein the composition comprises: a) 0.5-35%wt of one or more surfactants wherein at least 40% of the total surfactant is anionic that has been obtained by using one or more minerals from the dolomites group for neutralisation of the acid precursor; and b) 30-95%wt of at least one particulate abrasive.|
|Full Text||COMPLETE AFTER PROVISINAL
THE PATENTS ACT, 1970 (39 of 1970)
(See Section 10)
IMPROVED DETERGENT 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 synergistic abrasive cleaning compositions, containing a novel selective combination of surfactants and a process for producing the same. The compositions are suited to the cleaning of fabric or hard surfaces, more particularly suited to hard surfaces.
Background and Prior art:
Fabric washing compositions contain, as an essential ingredient, a surfactant system whose role is to assist in removal of soil from the fabric and its suspension in the wash liquor. Other important components are the detergent builders together with optional components for example abrasives, fillers, perfumes, alkaline salts and bleaching agents.
Commercial hard surface cleaning compositions typically comprise one or more surfactants and a plurality of abrasives dispersed therein. Combinations of these together with electrolytes are generally used to form a suspending system as is well known in the art. The surfactants are generally chosen to be anionic, nonionic, cationic, or zwitterionic. One or more surfactants selected from amongst primary alcohol sulphates, alkyl benzene sulphonates, alcohol ethoxylates, alkyl ether sulphates, fatty acid soaps and secondary alkyl sulphonates are more commonly employed.
Hard surface cleaners are often formulated in the form of liquids, bars, pastes and powders. Typical abrasives used in these compositions include calcite, feldspar and dolomite. Cleaning compositions in the bar form connote economy in use and are superior as compared to other product forms. The product dosage per swipe from the bar is highly controlled in comparison to the other forms such as paste, gel or powder.
The bar also does not get easily sogged in the presence of water and the active ingredients are not lost.
Commercial hard surface cleaning compositions typically comprise, one or more anionic surfactants and it is necessary to neutralise the acid form using alkali such as an alkali metal or alkaline earth metal salt to obtain a surfactant with the respective counter ion.
GB 1 542 696 (P&G) discloses a liquid detergent composition for fabric washing wherein the acid form of the anionic surfactant is neutralised with calcium or magnesium or a mixture thereof to ensure better stability of the product. US 3673122 (Chevron Res) discloses a detergent bar wherein the precursor of anionic surfactant is neutralised with sodium or magnesium salt. US 3867317 (Woo G L) discloses a detergent bar where precursor of anionic surfactant is neutralised with calcium salt.
Dolomite, a naturally occurring mineral, is the principle member of the dolomites group of minerals. The minerals that belong to the dolomites group are Ankerite Ca(Fe, Mg, Mn) (C03)2, Benstonite (Ba, Sr)6(Ca, Mn)6Mg(C03)i3, Dolomite CaMg(C03)2 or Huntite CaMg3(C03)4. The basic anionic (negatively charged) unit of this class consists of a triangle where at the centre resides a carbon atom. At every corner of the triangle sits a oxygen atom. The threefold symmetry of the triangle explains the trigonal symmetry that many members of this class possess. The structure of the dolomites group of minerals is layered in such a way that the "A" metal ions occupy one layer which is followed by a carbonate layer which is followed by the "B" metal ion layer followed by another carbonate layer, etc. The layering structure may be depicted as
A|C03|B|C03|A|C03|B|C03 , dolomite symmetry class is bar 3. In Dolomite the A
& B ions are Ca and Mg which have the largest ionic radius differential of the group (-33%). If the A & B ions are close in radius, they tend to not segregate as easily as its A & B layers, which is required to form this structure and therefore these minerals.
It has now been found that the selective use of anionic surfactant that has been neutralised using one or more minerals from the dolomites group thereby resulting in a
dolomite salt of the corresponding anionic surfactant (e.g: neutralisation of linear alkyl benzenesulphonic acid (LAS acid) resulted in dolomites-LAS (DoLAS)), either alone or in combination with other surfactants in cleaning compositions, gives significantly superior soil removal from hard surfaces or fabric as compared to the formulations with other conventional surfactants. It has been possible to formulate compositions so that the product gives significantly superior in-use properties.
Detergent bars manufactured by conventional routes generally have an active surfactant level ranging from 10-30% by weight of the composition. In hard surface cleaning bars high surfactant level leads to the problem of rinsabiliry and excessive water usage. However, with conventional ingredients the bars prepared with lower level of surfactant have problems of structuring, processibiliry and product stability. To solve these problems
additional bar structuring materials such as polymers and gums have been
incorporated and this leads to additional cost. It has now been found that when a bar is prepared by incorporating selectively an anionic surfactant that has been neutralised using one or more dolomites either alone or in combination with other surfactants, it is possible to manufacture low surfactant content bars with superior physical and in-use properties without using other structuring aids, thus making the process more economical.
Summary of the Invention
Thus according to a preferred aspect of the present invention there is provided a synergistic abrasive cleaning composition comprising anionic surfactant and an abrasive wherein the composition comprises:
a) 0.5-35% wt. of one or more surfactants wherein at least 40% of the total surfactant is anionic that has been obtained by using one or more minerals from the dolomites group for neutralisation of the acid precursor; and
b) 30-95% wt. of at least one particulate abrasive.
According to a preferred aspect of the invention there is provided synergistic abrasive bar cleaning composition comprising:
a) 3-25% wt of one or more surfactant wherein at least 40% of the surfactant is anionic that has been obtained using dolomites for neutralization of the acid precursor; and
b) 70-85% wt of at least one particulate abrasive
According to a more preferred aspect of the invention there is provided synergistic abrasive bar cleaning composition comprising:
a) 3-7%wt of one or more surfactant wherein at least 80% of the surfactant is anionic that has been obtained using dolomites for neutralization of the precursor acid; and
b) 70-85%wt of at least one particulate abrasive
According to another aspect of the invention there is provided a process of manufacture
of detergent composition comprising the steps of:
i. Neutralisation of at least 40% the acid precursor of the anionic surfactant using at
least one mineral of the dolomites group; ii. Neutralising any further precursor acid and optionally adding other surfactants; iii. Mixing abrasives and other conventional ingredients such that the total amount of
surfactant is between 0.5 and 35% and the amount of abrasives is 30-95% and
processing the mixture in a regular manner.
According to a preferred aspect of the invention there is provided a process of manufacture of detergent bar composition comprising:
a) 3-7% wt of one or more surfactant wherein at least 80% of the surfactant is anionic that has been obtained using dolomites for neutralization of the acid precursor; and
b) 70-85% wt of at least one particulate abrasive
which process comprises the steps of:
i. Neutralisation of at least 80% the precursor acid of the anionic surfactant using at
least one dolomite; ii. Optionally adding other surfactants; iii. Mixing conventional ingredients and processing the material in a regular manner.
It is especially preferred that the level of dolomite added is in far excess of the stoichiometric amount required for neutralisation of the precursor acid of the anionic surfactant. More specifically it is desired that all the dolomite that is incorporated in the composition is added at the time of neutralisaafion.
The composition may be formulated as a liquid cleaner, powder, bar or paste.
Detailed Description of the Invention:
The invention will now be described in greater detail 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 and laundry in general. All percentages herein are by weight, calculated on the total composition unless specifically mentioned otherwise.
The composition according to the invention will essentially comprise an anionic surfactant that has been obtained by neutralisation of the precursor using at least one dolomite, which may be combined with other surfactants generally chosen from alkali or alkaline earth metal, alkanolamine or ammonium salts of anionic surfactants and/or nonionic, cationic, amphoteric or zwitterionic detergent surfactants.
Suitable anionic detergent 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 detergent surfactant compounds are higher alkyl benzene sulphonates and mixtures with olefin sulphonates and higher alkyl sulphates, and the higher fatty acid monoglyceride sulphates obtained by neutralisation of the precursor using at least one dolomite. The more preferred anionic detergent surfactant compounds are higher alkyl aromatic sulphonates such as higher alkyl benzene sulphonates containing from 6 to 20 carbon atoms in the alkyl group in a straight or branched chain, particular examples of which are higher alkyl benzene sulphonates or of higher-alkyl toluene, xylene or phenol sulphonates, alkyl naphthalene sulphonates, diamyl naphthalene sulphonate, and dinonyl naphthalene sulphonate obtained by neutralisation of the precursor using at least one dolomite.
The amount of synthetic anionic detergent surfactant to be employed in the detergent composition of this invention will generally be up to 35% and most preferably from 3 to 25% by weight wherein at least 40% of the detergent surfactant is obtained by neutralisation of the precursor using at least one dolomite.
Dolomite according to the invention refers to minerals with an unusual trigonal bar 3 symmetry and with the general formula AB(C03)2, where A can be either calcium, barium, and/or strontium and B can be iron, magnesium, zinc and/or manganese. It is preferred that A is calcium and B is magnesium.
The dolomites can be selected from the naturally occurring materials such as Ankerite Ca(Fe, Mg, Mn) (C03)2, Benstonite (Ba, Sr)6(Ca, Mn)6Mg(C03)i3, Dolomite CaMg(C03)2 or Huntite CaMg3(C03)4. It is particularly preferred to use Dolomite.
Suitable nonionic detergent surfactant compounds 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 degree of 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 dimethyldodecylphosphine 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 methyltetradecyl 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 glucosides.
The amount of nonionic detergent surfactant to be employed in the detergent composition of the invention will generally be from 0.5 to 15% weight of the total surfactant, preferably from 5 to 10% by weight of the total surfactant.
It is also possible optionally to include amphoteric, cationic or zwitterionic detergent surfactants in the compositions according to the invention.
Suitable amphoteric detergent-surfactant compounds 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-solubilizing group, for instance sodium 3-dodecylamino-propionate, sodium 3-dodecylaminopropane sulphonate and sodium N-2-hydroxydodecyl-N-methyltaurate. Suitable cationic detergent-surfactant compounds are quaternary ammonium salts having an aliphatic radical of from 8 to 18 carbon atoms, for instance cetyltrimethyl ammonium bromide.
Suitable zwitterionic detergent-surfactant compounds 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 detergent-surfactant compounds are compounds commonly used as surface-active agents given in the well-known textbooks "Surface Active Agents", Volume I by Schwartz and Perry and "Surface Active Agents and Detergents", Volume II by Schwartz, Perry and Berch.
A particulate abrasive phase is an essential feature of compositions according to the present invention.
Preferably, the particulate phase comprises a particulate abrasive which is insoluble in water. In the alternative, the abrasive may be soluble and present Hi 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, silicas, silicates, other carbonates, aluminas, bicarbonates, borates, sulphates and polymeric materials such as polyethylene.
Preferred abrasives for use in general purpose compositions have a Moh hardness 2-7 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.
Preferred levels of abrasive range from 30 to 85wt% of the composition. The particulate with a liquid absorptive capacity of 100 to 300% may optionally be incorporated and can be selected from gel, precipitated or spray dried silica. The most preferred particulates with a liquid absorptive capacity being precipitated silica. The preferable levels at which the particulates with a liquid absorptive capacity are incorporated in the formulation are at a range of 1-10 wt%.
Solvents can be incorporated in the compositions of the invention to obtain additional benefits. Suitable solvents include saturated and unsaturated, linear or branched hydrocarbons, and/or materials of the general formula:
wherein R1 and R2 are independently CI-7 alkyl or H, but not both hydrogen, m and n are independently 0-5.
Preferred solvents are selected from the group comprising C10H16 terpenes, C10-C16 straight chain paraffins, and the glycol ethers. Suitable glycol ethers include di-ethylene glycol mono n-butyl ether, mono-ethylene glycol mono n-butyl ether, propylene glycol n-butyl ether and mixtures thereof.
Suitable terpenes include d-limonene. Preferred paraffins include the material available in the marketplace as Shellsol-T' (TM).
Typical level of the solvent range from 1-15% wt. It is particularly preferred to use terpenes at levels 1-3% wt. Some of these terpene materials, such as limonene, have the further advantage that they exhibit insect-repellency. The straight chain paraffins can be used at higher levels than the terpenes, as these materials are less aggressive to plastics.
The glycol ethers are preferred over the other solvents, at typical levels of 3-10% wt. on product with di-ethylene glycol mono n-butyl ether being particularly preferred.
Advantageously, a portion of the solvent can be introduced as a perfume component, although the levels of solvent required would generally require the addition of higher levels of this component that would normally be present as a perfume ingredient in cleaning compositions. Preferably the terpenes are used in this manner as selected terpenes, such as limonene, have a pleasant citrus smell, whereas paraffins and glycol ethers are generally odourless.
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 special water-soluble salts such as nitrilotriacetates, polycarboxylates, citrates, dicarboxylic acids, water-soluble phosphates especially polyphosphates, mixtures of ortho- and pyrophosphates, 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 the builder other than the special water-soluble salts when employed, preferably will form from 0.1 to 25% by weight of the composition.
Composition according to the invention can also contain, in addition to the ingredients already mentioned, various other optional ingredients such as structurants, colourants, whiteners, optical brighteners, soil suspending agents, detersive enzymes, compatible bleaching agents (particularly hypohalites), and preservatives.
The synergistic cleaning compositions according to the invention is prepared by mixing the active detergent produced according to the invention with other optional ingredients in the desired amounts in a conventional manner.
The invention will now be illustrated with respect to the following non-limiting examples.
Process for preparation of a bar:
15 kg batches of the different formulations disclosed in Table 1 and 2 were prepared by using linear alkylbenzene sulphonic acid (LAS acid) as an anionic surfactant precursor, which was taken in a sigma mixer and some amount of water was added. To this LAS-water mixture sodium carbonate (Example 1 and 6), magnesium carbonate (Example 2 and 7), calcium carbonate (Example 3 and 8) and 1:1 magnesium carbonate and calcium carbonate (Example 4 and 9) in stoichiometric proportion was added slowly and mixed for 10 min for the reaction to complete. In Example 5 and 10 the neutralisation was carried out using the entire Dolomite that went into the formulation. Subsequently the other ingredients were added and processed in a conventional manner.
a. Cleaning efficiency:
Examples 1 to 5 prepared by the process described above were tested for their cleaning efficiency by the following procedure. A synthetic soil comprising of saturated and unsaturated oils is made and known quantity of the soil is uniformly spread onto both the sides of a stainless steel plate. A known amount of sample dispersion is taken in a
petridish and using an applicator, both the sides of the plates were cleaned. The efficacy of the product was judged by the number of clean plates.
Composition, (wt%) Ex.1 Ex.2 Ex.3 Ex 4 Ex.5
DoLAS (Dolomite LAS) - ~ ■ ■ 14
Mg(LAS)2 - 14 - 7 -
Ca(LAS)2 - 14 7 -
NaLAS (14 - - - -
China clay 30 30 30 30 30
Dolomite 42 42 42 42 42
Structurants 6 6 6 6 6
Water to 100
Performance: Number of Clean Plates 9 8.5 9 8.5 13
The data presented in Table 1 show that the performance of the composition where the active ingredient was obtained in accordance with the invention (Example 5) was synergistically superior to the other control formulations.
b. Processability of low surfactant bars:
Composition, (wt%) Ex.6 Ex.7 Ex.8 Ex.9 Ex 10
DoLAS (Dolomite LAS) ■ - - - 3
Mg(LAS)2 - 3 - 1.5 -
Ca(LAS)2 - - 3 1.5 -
NaLAS 3 - - - -
China clay 30 30 30 30 30
Dolomite 48 48 48 48 48
Sulphate salt of a cation 2 2 2 2 2
Alkaline silicate(s) 4 4 4 4 4
Water to 100
Processibility Not Process-able Not Process-able Not Process-able Not Process-able Process-able
It was seen that only formulation according to Example 10 which is in accordance with the invention was processable when the surfactant level was as low as 3% by wt.
Examples 11 and 12
Performance evaluation by a trained consumer panel:
Control bars and bars according to the invention were prepared as described earlier and
the formulation details are presented in Table 3. The control bars (Example 11) were
similar to Example 1 and the bars according to the invention (Example 12) were similar
to Example 5 but the level of the active detergent was only 9% by weight of the
Composition, (wt%) Ex. 11 Ex. 12
DoLAS (Dolomite LAS) ~ 9.0
NaLAS 14 -
China clay 25 25
Dolomite 44 44
Structurants* 9.5 9.5
Water to 100
* Include a combination of alkaline silicate, aluminium sulphate, sodium carbonate.
The bars mentioned above (Ex. 11 and Ex. 12) were given to a group ofjtrained panellists for evaluation of various bar attributes that have been listed in Table 4. The bars were used by the panellists and rated on a scale of 0 to 10. Depending on the preference given by them for the various attributes the data were analysed statistically and has been presented in Table 4.
1 Attributes Ex.11. Ex.12
1 Perfume 6 21*
Bright colour 2.5 24.5*
Gritty 6 21*
Bar pick up 10 17*
Lather 16 11
Cleaning efficiency 12.5 14.5
Shine 10.5 16.5
* Significantly different from control.
The data presented show that the bar according to the invention was superior to the Control bar, in all the sensory attributes. In general, the cleaning efficiency is directly proportional to the active detergent in the bar. Since the bar prepared according to the invention had significantly lower level of active detergent but was on par with the control bar in cleaning efficiency. This clearly indicates the superior performance of the bar according to the invention as compared to the control.
1. A synergistic abrasive cleaning composition comprising anionic surfactant and an
abrasive wherein the composition comprises:
a) 0.5-35%wt of one or more surfactants wherein at least 40% of the total surfactant is anionic that has been obtained by using one or more minerals from the dolomites group for neutralisation of the acid precursor; and
b) 30-95%wt of at least one particulate abrasive.
2. Composition according to claim 1 wherein the amount of surfactant is 3-25%wt.
Composition according to claims 1 or 2 wherein the amount of surfactant is 3-7%wt
Composition according to claims 1-3 wherein the amount of anionic surfactant obtained by dolomites neutralisation of precursor acid is 80% of the total surfactant.
5. Composition according to claims 1-4 wherein the mineral from the dolomites group is Dolomite.
6. Composition according to claims 1 -5 wherein the amount of abrasive is 70-85%.
7. Composition according to claims 1 -6 which is in the form of a bar.
8. A process for the manufacture of a synergistic abrasive cleaning composition which comprises the steps of :
i Neutralising at least 40% of the acid precursor of an anionic surfactant
with one or more minerals from the dolomites group
ii Neutralising any further precursor acid and optionally adding other
iii Mixing abrasives and other conventional ingredients such that the total amount of surfactant is between 0.5 and 35% and the amount of abrasives is 30-95% and processing the mixture in a regular manner.
9. Process according to claim 8 wherein the amount of surfactant is 3-25%wt.
10; Process according to claims 8 or 9 wherein the amount of surfactant is 3-7%wt
11. Process according to claims 8-10 wherein the amount of anionic surfactant
obtained by dolomites neutralisation of precursor acid is 80% of the total
12. Process according to claims 8-11 wherein the mineral from the dolomites group is Dolomite.
13. Process according to claims 8-12 wherein the amount of abrasive is 70-85%.
14. A synergistic abrasive cleaning composition and a,process for manufacturing^the
same substantially as hereindescribed and illustrated with reference to the
Dated this 15th day of March 2001
HINDUSTAN LEVER LIMITED
(S. Venkatramani) Patents Manager
|Indian Patent Application Number||225/MUM/2000|
|PG Journal Number||43/2008|
|Date of Filing||16-Mar-2000|
|Name of Patentee||HINDUSTAN UNILEVER LIMITED|
|Applicant Address||1913 AND HAVING ITS REGISTERED OFFICE AT HINDUSTAN LEVER HOUSE, 165/166, BACKBAY RECLAMATION, MUMBAI - 400 020, MAHARASHTRA, INDIA|
|PCT International Classification Number||C 11 D 9/18|
|PCT International Application Number||N/A|
|PCT International Filing date|