WO2000020544A1

WO2000020544A1 - Non-liquid abrasive composition

Info

Publication number: WO2000020544A1
Application number: PCT/EP1999/005758
Authority: WO
Inventors: Kamsu Venkata Sathyanarayana Murthy; Suresh Ramamurthi; Devadatta Shivaji Sankholkar
Original assignee: Hindustan Lever Ltd; Unilever NV
Current assignee: Hindustan Unilever Ltd; Unilever NV
Priority date: 1998-10-06
Filing date: 1999-08-06
Publication date: 2000-04-13
Anticipated expiration: 2001-04-06
Also published as: ID27915A; AR020684A1; AU5421499A; GB9821784D0

Abstract

The invention provides a non-liquid synergistic abrasive cleaning composition which comprises of 10-50%wt of at least one particulate abrasive; 0.5-15%wt of a C2-C6 alkanolamine; at least 0.1%wt of an electrolyte base other than alkanolamine; 0.1-35%wt of at least one surfactant; and optionally, 0.1-20%wt of a solvent other than water or alkanolamine.

Description

Non-Liquid Abrasive Composition

Technical field :

The invention relates to non-liquid abrasive cleaning compositions, containing particulate abrasives, which are suited to the cleaning of hard surfaces.

Background and Prior art :

Commercial hard surface cleaning compositions typically comprise, 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, and a plurality of abrasives dispersed in. Combinations of these together with electrolytes are generally used to form a suspending system as is well known in the art.

Solvents are well known components of non-abrasive cleaning compositions. Typical solvents used in cleaning compositions include, alcohols (such as ethanol), ethers (such as Butyl Cellosolve [TM] ) , paraffins (such as Isopar L [TM] ) , esters and terpenes (such as d-limonene) . Another known class of solvents are the alkanolamines . EP503219A (P&G) relates to a cleaning composition containing 0.1-10% of an al anolamine.

Non-liquid abrasive cleaning compositions in the form of pastes, gels and powders are also known. Typical abrasives used in these compositions include calcites and dolomites. It is the basic objective of the present invention to provide a non-liquid synergistic abrasive cleaning composition in the form of a paste or gel which would effectively clean and will also be storage stable.

Another object of the present invention is to provide a non- liquid synergistic abrasive cleaning composition in the form of a paste or a gel with alkanolamine and a base other than alkanolamine for the removal of difficult soils.

Yet another object of the present invention is to provide improved non-liquid synergistic abrasive cleaning composition with significant levels of a C₂-C₆ alkanolamine and an electrolyte base other than alkanolamine.

Thus according to one aspect of the present invention there is provided a non-liquid synergistic abrasive cleaning composition comprising :

a) 10-50%wt of at least one particulate abrasive ;

b) 0.5-15%wt of a C₂-C₆ alkanolamine ;

c) at least 0.1%wt of an electrolyte base other than alkanolamine ;

d) 0.1-35%wt of at least one surfactant ; and

e) optionally, 0.1-20%wt of a solvent other than water or alkanolamine . According to another aspect the invention provides a process for the preparation of the non- liquid synergistic abrasive cleaning composition comprising the steps of:

a) in-situ generation of alkaline alumino silicate and making a dough containing surfactants and other particulate abrasives ;

b) addition of alkanolamine and the electrolyte base followed by addition of other optional ingredients, mixing to obtain the desired product form.

Also described is a method of cleaning cooking utensils or crockery comprising the steps of applying directly the composition described above to the cooking utensils or crockery.

In the context of the present invention non-liquid abrasive cleaners relates to products in the form of a paste or a gel .

Abrasives 10 to 15 %wt of the total composition of particulate abrasive is an essential ingredient 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 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 can be 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 2-6 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, with values of around 10-200 microns being preferred.

Preferred levels of abrasive range from 15-45wt % on product, preferably in the range 20-40wt%. The physical form of the product will be influenced by the level of abrasive present .

The most preferred abrasives are calcium carbonate (as Calcite) , mixtures of calcium and magnesium carbonates (as dolomite) , sodium hydrogen carbonate, potassium sulphate, zeolite, alumina, hydrated alumina, feldspar, talc and silica. Calcite, feldspar and dolomite and mixtures thereof are particularly preferred due to their low cost, suitable hardness and colour.

Alkanolamines

Alkanolamines 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 formulation H₂N- Ri-OH where Ri is a linear or branched alkyl chain having 2-6 carbons .

Preferred alkanolamines include 2-amino-2-methyl-l-propanol , mono- di- and tri- ethanolamine, mono- di- and tri isopropanolamine, dimethyl-, diethyl or dibutyl ethanolamine, and mixtures thereof. It is envisaged that cyclic alkanolamines such as morpholine can also be employed.

Particularly preferred alkanolamine specially to clean tough or aged soil is 2-amino-2-methyl-l-propanol (AMP) .

Typical levels of alkanolamine in the compositions of the invention range from l-10%wt. It is particularly preferred to use 2-amino-2-methyl-l-propanol at a level of 2-6%wt. Electrolyte base

Suitable electrolyte bases include soluble carbonates and bicarbonates, although use of hydroxides and other alkaline salts is not excluded. Alkali metal carbonates are particularly preferred, with potassium carbonate being the most preferred. Typical levels of electrolytes range from 0.5-5%wt, with l-2.5%wt being particularly preferred. The level of the electrolyte should be such that in use the pH of the composition is raised above the pKa of the alkanolamine, and preferably to a pH at least one unit above the pKa of the alkanolamine.

Surfactants

The composition according to the invention will preferably comprise detergent actives, which are generally chosen from both anionic and nonionic detergent actives.

Suitable anionic detergent active compounds 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 sulphur acid ester radicals and mixtures thereof.

Examples of suitable anionic detergents are sodium and potassium alcohol sulphates, especially those obtained by sulphating the higher alcohols produced by reducing the glycerides of tallow or coconut oil; sodium and potassium alkyl benzene sulphonates such as those in which the alkyl group contains from 9 to 15 carbon atoms; sodium alkyl glyceryl ether sulphates, especially those ethers of the higher alcohols derived from tallow and coconut oil; sodium coconut oil fatty acid monoglyceride sulphates ; sodium and potassium salts of sulphuric acid esters of the reaction product of one mole of a higher fatty alcohol and from 1 to 6 moles of ethylene oxide ; sodium and potassium salts of alkyl phenol ethylene oxide ether sulphate with from 1 to 8 units of ethylene oxide molecule and in which the alkyl radicals contain from 4 to 14 carbon atoms; the reaction product of fatty acids esterified with isethionic acid and neutralised with sodium hydroxide where, for example, the fatty acids are derived from coconut oil and mixtures thereof .

The preferred water-soluble synthetic anionic detergent active compounds are the alkali metal (such as sodium and potassium) and alkaline earth metal (such as calcium and magnesium) salts of higher alkyl benzene sulphonates and mixtures with olefin sulphonates and higher alkyl sulphates, and the higher fatty acid monoglyceride sulphates . The most preferred anionic detergent active 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 sodium salts of higher alkyl benzene sulphonates or of higher-alkyl toluene, xylene or phenol sulphonates, alkyl naphthalene sulphonates, ammonium diamyl naphthalene sulphonate, and sodium dinonyl naphthalene sulphonate. The amount of synthetic anionic detergent active to be employed in the detergent composition of this invention will generally be up to 20% and most preferably from 2 to 15% by weight .

Suitable nonionic detergent active 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 R₃P0, 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 amount of nonionic detergent active to be employed in the detergent composition of the invention will generally be from 0.5 to 15% wt . , preferably from 5 to 10% by weight.

It is also possible optionally to include amphoteric, cationic or zwitterionic detergent actives in the compositions according to the invention.

Suitable amphoteric detergent-active 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-active compounds are quaternary ammonium salts having an aliphatic radical of from 8 to 18 carbon atoms, for instance cetyltrimethyl ammonium bromide. Suitable zwitterionic detergent-active 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-active 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.

The total amount of detergent active compound to be employed in the detergent composition of the invention will generally be from 1.5 to 20%, preferably from 2 to 15% by weight.

Solvents

Solvents other than AMP can be present in the compositions of the invention and their presence is preferred for this reason.

Suitable solvents include saturated and unsaturated, linear or branched hydrocarbons, and/or materials of the general formula:

Rι-0-(EO)_m-(PO)_n-R₂ wherein R_x and R₂ are independently Cl-7 alkyl or H, but not both hydrogen, m and n are independently 0-5.

Preferred solvents are selected from the group comprising CioHi₆ terpenes, Cι₀-Cι₆ 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 levels of 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 the 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 paraffins are believed to give better performance at in use pH ' s above 11.

The glycol ethers are preferred over the other solvents, at typical levels of 5-10% wt . on product with di-ethylene glycol mono n-butyl ether being particularly preferred.

It is preferred that the ratio of the alkanolamine to the solvent falls in the range 3:1 - 1:3, with ratios of 1:1 to

1:3 being particularly preferred. Advantageously, a portion of the solvent can be introduced as a perfume component, although the levels of solvent required will 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.

Rheology and Structuring Agents

As described above the compositions of the invention can be pastes or gels. Suitable rheological control agents can be present especially when the compositions contain significant amounts of water or low viscosity surfactants. These control agents include fumed silicas and clays.

It is found that 1-2% of a fumed silica is sufficient to stabilise a paste. Aerosil 380 (TM) is a suitable structuring agent .

It is also found that the addition of 1-8% water can also be sufficient to stabilise compositions, which are prone to separation.

Compositions, which contain mixed surfactant systems, are also believed to be stable against phase separation. We have determined that a composition which contains both an ethoxylated alcohol nonionic surfactant and a nonionic alkyl polyglucoside (APG) surfactant is stable against phase separation.

The compositions according to the invention may optionally contain polymeric structuring agents to aid in providing appropriate rheological properties and in enhancing their distribution and adherence of the composition to the hard surface to be cleaned.

Preferred structuring agents include polysaccharides, such as sodium carboxymethyl cellulose and other chemically modified cellulose materials, xanthan gum and other non- flocculating structuring agents such as biopolymer PS87 referred to in US patent No. 4 329 448.

Certain polymers such as a polymer of acrylic acid cross- linked with a poly functional agent, for example CARBOPOL R, can also be used as structuring agents. The amount of such structuring agents, when employed, to be used in compositions according to the invention can be as little as

0.001%, preferably at least 0.01% by weight of the composition.

In general the composition of the invention can optionally comprise from 0.1-1% of polymer.

Optional ingredients

The composition according to the invention can contain other ingredients, which 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 colourants, whiteners, optical brighteners, soil suspending agents, detersive enzymes, compatible bleaching agents (particularly hypohalites) , and preservatives.

The invention will now be illustrated with respect to the following non-limiting examples.

Examples : Process for preparation of the composition:

A batch of 25Kg was processed. 1250g of sodium carbonate was mixed with 3750g of sodium salt of linear alkyl benzene sulphonate in a sigma mixer. 2500g of china clay was added followed by 2000g of butyl digol and mixed. To this 250g of aluminum sulphate, 5250g of feldspar and 500g of alkaline silicate was added and mixed thoroughly. 2000g of 2-amino-2- methyl-1-propanol (AMP) , 250g of sodium bicarbonate followed by minor ingredients and water were added and mixed to obtain a uniform paste. The above process was employed for all the formulations presented in Table 1. The Examples 6 to 8, however were in the form of a solution. Table 1

In use properties of the bar:

a. Tough soil cleaning.

The oil that has been polymerised by heating at high temperature is known as tough soil. Vegetable oil is smeared uniformly on a stainless steel plate and heated to get a polymerised oil film on the plate.

0.12g of the product was uniformly rubbed on the soiled plate and then rinsed with water. The performance was assessed to determine percentage cleaning visually by trained personnel . The experiment was conducted with replicates and analysed statistically. Table 2

b. Cleaning of unpolymerised oily soil.

Uniform quantity of vegetable oil is spread on stainless steel plates and the number of such soiled plates that can be cleaned for a particular quantity of the product was assessed.

Table 3

The data presented in tables 2 and 3 shows that the product according to the invention acts synergistically with respect to cleaning of tough soil but there was no significant difference with respect to cleaning of unpolymerised oil .

Claims

CLAIMS :

1. A non-liquid synergistic abrasive cleaning composition in the form of a paste or gel comprising:

a) 10-50%wt of at least one particulate abrasive; b) 0.5-15%wt of a C2-C6 alkanolamine; c) at least 0.1%wt of an electrolyte base other than alkanolamine ; d) 0.1-35%wt of at least one surfactants ; and e) optionally, 0.1-20%wt of a solvent other than water or alkanolamine .

2. A non-liquid abrasive cleaning composition as claimed in claim 1 wherein said particulate abrasive is present from 15-45 wt% preferably 20-40 wt%.

3. A non-liquid abrasive cleaning composition as claimed in claim 1 or claim 2, wherein said particulate abrasive comprise calcium carbonate (Calcite) , mixtures of calcium and magnesium carbonates (dolomite) , sodium hydrogen carbonate, potassium sulphate, zeolite, alumina, hydrated alumina, feldspar, talc and silica.

4. A non-liquid abrasive cleaning composition as claimed in anyone of claims 1 to 3 wherein said alkanolamines comprise 2-amino-2-methyl-l-propanol, mono-di- and tri- ethanolamine, mono-di and tri- isopropanolamine, dimethyl-diethyl or dibutyl ethanolamine, and mixtures thereof preferably 2-amino-2-methyl-lpropanol (AMP) .

5. A non-liquid abrasive cleaning composition as claimed in anyone of claims 1 to 4 wherein said alkanolamine range from 1-10% wt . preferably 2-6% wt .

6. A non-liquid abrasive cleaning composition as claimed in anyone of claims 1 to 5 wherein said electrolyte base comprise soluble carbonates, bicarbonates, hydroxides and alkaline salts preferably alkali metal carbonates.

7. A non-liquid synergistic abrasive cleaning composition as claimed in claim 6 wherein said alkali metal carbonate comprise potassium carbonate.

8. A non-liquid abrasive cleaning composition as claimed in anyone of claims 1 to 7 wherein said electrolyte base range from 0.5-5% wt . preferably 1-2.5% wt .

9. A method of cleaning cooking utensils or crockery comprising the steps of applying directly the composition described in any previous claim to the cooking utensils or crockery.

10. A process for the preparation of the abrasive cleaning composition as claimed in anyone of claims 1 to 39 comprising:

a) in-situ generation of alkaline alumino silicate and making a dough containing surfactants and other particulate abrasives ; b) addition of alkanolamine and the electrolyte base followed by addition of other optional ingredients, followed by mixing to thereby obtain the composition.