EP0479826B1

EP0479826B1 - Cleaning composition

Info

Publication number: EP0479826B1
Application number: EP90909473A
Authority: EP
Inventors: Peter Leonard Dawson; Thomas 39 Brookhurst Avenue Stirling
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 1989-06-23
Filing date: 1990-06-22
Publication date: 1996-01-17
Anticipated expiration: 2010-06-22
Also published as: AU630470B2; ES2082859T3; ZA904890B; GB8914462D0; WO1991000332A1; BR9007469A; CA2019642A1; DE69024957D1; AU5840390A; DE69024957T2; EP0479826A1; JPH0689360B2; CA2019642C; JPH04504278A

Abstract

An aqueous cleaning compositiion suitable for hard surfaces contains ammonia or an alkanolamine having a boiling point below 200°C at atmospheric pressure, plus a cationic polymer having a molecular weight over 5,000, in an aqueous system containing an organic solvent which has a boiling point below 200°C at atmospheric pressure; preferably with at most a limited amount of surfactant and other materials which do not boil below 200°C at atmospheric pressure.

Description

This invention relates to an aqueous cleaning composition intended to be suitable for use undiluted in cleaning various surfaces notably fixed surfaces exemplified by glass, paintwork, ceramic tiles, vinyl flooring, chromium plate, marble and plastic laminates. It is intended that rinsing should be unnecessary.
Existing general purpose cleaning products which are intended for household use generally clean effectively but then need rinsing or subsequent buffing to obtain a good result, particularly on high gloss surfaces like glass or chrome. Existing products specifically for window cleaning often recommend using the product in limited quantity, then rubbing dry with a dry cloth in order to avoid streaks or smears. In practice usage is often at above the recommended level, and rubbing completely dry can be difficult. As the cleaning job progresses, the users' cloth will, of course, become wet with soiled product solution absorbed by the cloth. These factors often lead to visible deposits being left on the window or mirror.
At least in preferred forms, this invention seeks to provide a product which will give a good finish to the surface being cleaned despite usage at higher levels than necessary and/or incomplete removal. It is intended that no visible residue should remain on the surface which has been cleaned.
According to the present invention, there is provided an aqueous cleaning composition comprising:

0.1-10% by weight of ammonia or an alkanolamine having a boiling point below 200°C at atmospheric pressure and 0.001 to 0.5%, better 0.001 to 0.05% of cationic polymer having a molecular weight over 5000;
in a solvent system comprising water and optionally up to 10% by weight of an organic solvent which has a boiling point below 200°C at atmospheric pressure or has an evaporation rate greater than 0.01 times that of n-butyl acetate at 20°C, and preferably includes an alkyl group of 1 to 5 carbon atoms, such as a propyl, butyl or pentyl group, together with at least one hydroxyl group;
the composition being substantially free of inorganic electrolyte and containing at most 0.5% by weight of surfactant and any other materials which do not boil below 200°C at atmospheric pressure. All the above percentages are based on the whole composition.

It is preferred that the total amount of surfactant and any other materials which do not boil below 200°C at atmospheric pressure does not exceed 0.2% by weight based on the whole composition.
Preferably, the said organic solvent is present in an amount which is at least 0.05% better from 0.5 to 10% by weight.
Compositions of this invention have a very large proportion of constituents which are sufficiently volatile for residues of them to evaporate from the surface. The property of boiling below 200°C at normal atmospheric pressure of 760mmHg is an indicator of adequate volatility.
The alternative assessment of volatility by comparison of evaporation rate with that of n-butyl acetate, is a method of judging volatility which is frequently used in the solvent industy.
When the composition is applied, say with a cloth, the bulk of the composition and solubilised soil will be removed by the cloth with which it is applied and/or a second cloth used subsequently. Most of the residue left on the surface will evaporate. Polar organic compounds with boiling points over 200°C generally do not have sufficient volatility for this: consequently the level of them is preferably very low, as stated above.
Preferred and essential constituents will now be discussed.
Preferably any organic solvent is sufficiently water soluble to give a single phase solvent system. However, it is possible to use a solvent of low water solubility and include sufficient solvent that there is a surplus of organic solvent forming a separate phase. This could be dispersed as an emulsion, or distributed through the product by shaking the container before use.
The preferred class of organic solvents are those which have both hydroxyl functionality and an alkyl group which is C₁ to C₅, preferably C₃ to C₅ alkyl. In this latter case, of course, the solvent will provide a combination of hydrophilic and hydrophobic functions, so that preferred solvents bring about a lowering of surface tension as well as helping to solubilise oily soils.
The C₃ to C₅ alkyl group may be linked directly to hydroxyl as in the case of aliphatic alcohols or it may be connected through a linking group containing both carbon atoms and an atom other than carbon or hydrogen - usually oxygen.
Suitable as organic solvents are those of structural formula:

R-X-OH

where R is C₁ to C₅ alkyl and X is a covalent bond or

-OCH₂CH₂-

or even -OC₂H₄OC₂H₄- or -OC₃H₆OC₃H₆-
but in all cases subject to the requirement for a boiling point below 200°C.
Suitable solvents having a formula as defined above include methanol, ethanol and the various isomers of propanol, butanol and pentanol, 2-propoxyethanol, 2-butoxyethanol, 2-pentoxyethanol, 1-propoxypropan-2-ol and
1-butoxypropan-2-ol.
Examples of less water soluble solvents which may be included, giving more than one phase, are paraffins, olefins, terpenes and alkyl benzenes, subject in each instance to the requirement that the boiling point is below 200°C.
The ammonia or alkanolamine serves to render the composition alkaline, which is beneficial for cleaning performance. Alkanolamines are preferred over ammonia; their hydroxy function serves to enhance water solubility and the amino group contributes to the solubilisation of polar fatty soils.
An alkanolamine meeting the requirement for boiling point below 200°C will generally be a monoalkanolamine, whose structural formula is:
where R¹ is hydroxy alkyl and R and R³ are (independently of each other) either hydrogen or alkyl.
The number of carbon atoms in the groups R¹, R, R³ is restricted by the requirement that the boiling point is not over 200°C. Generally not more than four carbon atoms will be present in total in the groups R¹, R and R³.
Monoethanolamine is the preferred compound. Further possibilities include 2-amino 2-methyl propanol, 2-aminopropanol, n-propanolamine, 2-amino 1-butanol, N-methyl ethanolamine and N,N-dimethyl ethanolamine.
The amount of alkanolamine may be up to 10% by weight of the composition. Preferably, however, the quantity is not greater than 5%, since quantities in excess of 5% produce little additional benefit in return for the extra cost. The amount of alkanolamine is preferably at least 0.5%.
The cationic polymer enhances the ability of the composition to remove particulate soils. Without being limited by our hypothesis as to its mode of action, it is believed that the polymer is able to cause aggregation of particulate soil particles without the disadvantage of causing excessive aggregation and interference with detergency, for example by binding the soil particles to the surface. Presumably then the resulting larger particles are more easily picked up by a cloth being used to wipe the surface being cleaned.
A variety of cationic polymers can be used. It is preferred that the molecular weight of the polymer is at least 10,000 better at least 50,000 or even better at least 100,000. It may be a high molecular weight of at least 1 million or even at least 5 million up to 20 million or more at the time of adding the polymer to the composition, although there may be some breakdown in the length of polymer chains in the composition.
Cationic polymers generally consist of a polymeric chain which does not have cationic character, bearing cationic substitute groups.
Certain cationic polymers can interact with anionic or amphoteric surfactants, reducing the effectiveness of both. We have found that if anionic surfactant is present, within the limit of 0.5% by weight surfactant, then it is desirable to use a cationic polymer with a hydrophilic polymer chain (e.g. polysaccharide or polyacrylamide) and not more than 50% (molar) cationic substitution on this chain. Preferably less than 35% or even less than 20% of the repeat units in the polymer chain have cationic substitution, and possibly as few as 10% are so substituted.
If anionic surfactant is absent, a wide range of cationic polymers can be used, including cationic polymers based on hydrophobic polymer chains such as polyethylene or polymethylene.
Cationic polymers which may be used in compositions of this invention include:

a) Polyacrylamides and polymethacrylamides made by copolymerisation of acrylamide or methacrylamide with e.g. dimethylamino-ethylmethacrylate (followed by quaternisation with dimethyl sulphate) or NN-dimethyl 3,5 methylene piperidinium chloride. Alternatively, poly(meth)acrylamides treated with alkaline hypochlorite or with an amine and formaldehyde provide cationically substituted polyacrylamides.
b) Starches treated with e.g. (4-chlorobutene-2)-trimethyl ammonium chloride, or β diethylamino ethyl chloride hydrochloride, or dimethylamino ethyl methacrylate, or 2,3-epoxypropyl trimethyl ammonium chloride. In particular, guar gums and hydroxyethyl celluloses cationised thus are useful.
c) Homopolymers of N,N-dimethyl-3,5 methylene piperidinium chloride or ethylene imine. Polyethylene imines and polyamines demonstrate useful cationic character up to pH's of 9-11 which are preferred for this invention.

It is advantageous for compositions of this invention to include some detergent active. However, because of the intended use without rinsing, the quantity of detergent active is restricted to at most 0.5% by weight of the composition, e.g. 0.01 to 0.5%, preferably not over 0.2%, while inorganic electrolyte is substantially absent.
Detergent actives which are used may be chosen from the conventional classes, that is to say anionic, nonionic, cationic and amphoteric detergents and mixtures thereof. Anionic detergent actives are preferred for the sake of their good detergency, but as stated above, some cationic polymers cannot be used with anionic detergents, for which reason nonionic detergent active may be preferred. In general, anionic, cationic and amphoteric detergent actives contain an alkyl group of 8 to 22 carbon atoms, or an alkyl aromatic group with 6 to 14 carbon atoms in the alkyl portion, and a charged head group.
Specific possibilities for anionic detergent actives are sodium C₁₀₋₁₂ alkyl benzene sulphonates and sodium C₁₂₋₁₅ synthetic alcohol 3EO sulphates. C₁₀₋₁₆ secondary alkane sulphonates are further possibilities.
Nonionic detergent actives may be 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 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, and condensates of synthetic primary or secondary alcohols having 8 to 15 carbon atoms with 3 to 12 moles of ethylene oxide per mole of the synthetic alcohol; also 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. Further examples of nonionic surfactants are condensates of the reaction product of ethylenediamine and propylene oxide with ethylene oxide, the condensates containing from 40 to 80% of polyoxyethylene radicals by weight and having a molecular weight of from 5,000 to 11,000; also block copolymers of ethylene oxide and propylene oxide.
Nonionic detergent actives may be compounds containing a C₈ to C₂₂ alkyl group and a polar head group (which may or may not be provided by alkylene oxide residues). Examples are tertiary amine oxides of formula

RR¹R¹NO

where the group R is an alkyl group of 8 to 18 carbon atoms and the groups R¹ are each methyl, ethyl or hydroxyethyl groups, for instance dimethyldodecylamine oxide; glycosides or polyglycosides etherified with at least one C₈-C₂₂ alkyl group or esterified with at least one C₈-C₂₂ fatty acyl group; fatty acid alkylolamides; and alkylene oxide condensates of fatty acid alkylolamides.
Mixtures of two or more nonionic detergent actives can be employed, as can mixtures of nonionic and anionic detergent actives.
The involatile constituents of a composition of this invention will be the detergent active and cationic polymer if these are used, together with part of any perfume if used. An approximate working rule is that half of a conventional perfume will class as involatile. It is very desirable that not more than 0.5% by weight of the composition, preferably not more than 0.2% is provided by such involatiles.
The compositions of this invention can be prepared by simply mixing their constituents into distilled or deionised water, e.g. in a mixing vessel with a stirrer.

EXAMPLES

The invention is illustrated by the following Examples of compositions (including some comparative Examples outside the invention). All percentages are by weight. The nonionic detergent was C₉ to C₁₁ synthetic alcohol ethoxylated with average 5 ethylene oxide residues. The cationic polymers used were:

Polymer of	Source	Approx Mol. wt.	Approx Degree Substitution (% molar)
Acrylamide
Floc Aid 300	National Starch	10m	2
Floc Aid 301	National Starch	10m	7
Floc Aid 371	National Starch	6m	2.5

Cationised Guar
Jaguar C-13	Meyhall	2m+	13

Polydimethyldiallylammonium
Merquat 100	Merck	½ m	100

Example 1

	% by weight
Propylene glycol monobutyl ether	3.0
Nonionic detergent	0.1
Cationic polymer (Floc-Aid 301)	0.01
Monoethanolamine	1.0
Distilled water	balance to 100%

Example 2

	% by weight
n-Butanol	3.0
Nonionic detergent	0.1
Cationic polymer (Floc-Aid 301)	0.01
Monoethanolamine	1.0
Distilled water	balance to 100%

Example 3

	% by weight
Isopropanol	5.0
Nonionic detergent	0.15
Cationic polymer (Floc-Aid 300)	0.01
Perfume	0.03
Monoethanolamine	1.0
Distilled water	balance to 100%

Example 4

	% by weight
Ethyl cellosolve (ethylene glycol moneoethyl ether)	2.0
Nonionic detergent	0.1
Cationic polymer (Floc-Aid 301)	0.01
Monoethanolamine	1.0
Distilled water	balance to 100%

Example A (comparative - dialkanolamine)

	% by weight
Propylene glycol monobutyl ether	3.0
Nonionic detergent	0.1
Cationic polymer (Floc-Aid 301)	0.02
Diethanolamine	1.5
Distilled water	balance to 100%

Example B (comparative - non-volatile solvent)

	% by weight
Butyl digol (C₄H₉-O-C₂H₄-O-C₂H₄-OH Bpt > 200°C)	5.0
Nonionic detergent	0.1
Cationic polymer (Floc-Aid 301)	0.01
2-methyl 2-amino propanol	1.0

Example C (comparative - inorganic alkaline electrolyte)

	% by weight
Propylene glycol monobutyl ether	3.0
Nonionic detergent	0.1
Sodium carbonate	1.5
Cationic polymer (Floc-Aid 301)	0.02

Example 5

	% by weight
Propylene glycol monobutyl ether	2.5
Nonionic detergent	0.2
Monoethanolamine	6.0
Cationic polymer (Floc-Aid 300)	0.01

Example 6

	% by weight
Propylene glycol monobutyl ether	2.5
Nonionic detergent	0.2
2-methyl 2-amino propanol	6.0
Cationic polymer (Floc-Aid 301)	0.01

Example D (comparative - high nonionic)

	% by weight
Ethyl cellosolve (ethylene glycol monoethylether)	2.0
Nonionic detergent	0.8
Monoethanolamine	1.0
Cationic polymer (Floc-Aid 301)	0.01

Example E (comparative - alkali absent)

	% by weight
Propylene glycol monobutyl ether	3.0
Nonionic detergent	0.1
Cationic polymer (Floc-Aid 301)	0.01
Distilled water	balance to 100%

Example 7 (ammonia as fugitive alkali)

	% by weight
Propylene glycol monobutyl ether	3.0
Nonionic detergent	0.1
Ammonia	0.5
Cationic polymer (Floc-Aid 301)	0.01
Distilled water	balance to 100%

Example 8 (solvent absent)

	% by weight
Monoethanolamine	1.0
Nonionic detergent	0.1
Cationic polymer (Floc-Aid 301)	0.01
Distilled water	balance to 100%

Example 9

	% by weight
Methoxypropoxypropanol	3.0
Nonionic detergent	0.1
Monoethanolamine	1.0
Cationic polymer (Floc-Aid 301)	0.01
Distilled water	balance to 100%

Example 10

	% by weight
Methoxypropanol (propylene glycol ether)	3.0
Moneothanolamine	1.0
Nonionic detergent	0.1
Cationic polymer (Floc-Aid 301)	0.01
Distilled water	balance to 100%

The compositions of the Examples were tested for streaking brought about by components of the composition and for effectiveness in cleaning.
Streaking is assessed subjectively on high gloss black-coloured ceramic tiles which have been wiped over with a sponge cloth loaded with a standard amount of formulation. The liquid film is allowed to evaporate before assessment is made. High gloss black tiles are a very discriminating surface for judgement of streaking and product residues.
Effectiveness was assessed using ceramic floor tiles soiled with either a predominantly fatty or a predominantly particulate soil. Soiled tiles were prepared by a combination of spraying of soil components from a solvent solution/suspension, followed by rubbing of soil into the surface to obtain an even coverage which cannot be easily wiped off with a dry cloth.
To assess cleaning performance, 3 drops of composition were applied to the soiled surface, allowed to soak for 10 seconds, then wiped off with a dry paper tissue.
The predominantly fatty soil consisted of 5 parts kaolin, 0.2 parts carbon black, 19 parts of glycerol trioleate and 1 part oleic acid. This represents a model for kitchen and bathroom soil. The predominantly particulate soil consisted of 8 parts Illite clay, 0.1 parts carbon black and 2 parts glycerol trioleate; this is a model for the soils found on floors and windows.
The results are expressed as a ranking of performance, 1 representing the standard achieved by Example 1, 1+ representing an even better result, 1-representing a slightly inferior result, and the values 2, 3 and 4 representing progressively inferior cleaning. Consequently the scale is:

Best: 1+
1
1-
2
3
Worst: 4

Example No Soil	Streaking	Fatty Soil	Particulate
1	None	1	1
2	None	1+	1
3	None	1	3
4	None	1	2
A	Very slight	1-	2
B	Streaky	3	3
C	Slight	2	2
5	Slight	1+	1+
6	None	1+	1
D	Very streaky	1	2
E	None	3	4
7	None	1	1-
8	Very slight	1	2
9	Very slight	1	2
10	None	1	1-

These results show that the products of the invention give good cleaning with very low residues of product on the cleaned surface.
The composition of Example 1, and various analogous compositions with different cationic polymer or none at all, were used to demonstrate the value of the cationic polymer in removal of particulate soil.
A 30cm x 30cm glass mirror is thoroughly cleaned and its reflectance is measured.
A soil consisting of 8 parts of Illite type clay and 0.1 parts of carbon black in ethanol is sprayed lightly and evenly onto the mirror. Reflectance is measured again. One half of the mirror (15cm x 30cm) is cleaned with experimental composition, the other half with a control window cleaning product. Each half is cleaned by placing ½ ml of composition on the soiled surface and wiping 32 times over the area with a dry non-woven viscose cloth (approx. 75 g.s.m.) 12 x 15cm. After allowing 1 minute to dry, the reflectance of the cleaned mirror surface is measured again. Knowing the reflectance of the perfectly clean mirror, the % loss due to initial and residual soil coverage can be calculated.
Results are as follows:
All of these cationic polymers led to substantial improvement compared with use of the composition having no cationic polymer. A similar result was found with a soil also containing 2 parts glycerol trioleate, which is the predominantly particulate soil referred to above.

Claims

An aqueous cleaning composition comprising ammonia or alkanolamine having a boiling point below 200°C at atmospheric pressure together with a cationic polymer having a molecular weight over 5,000 in an aqueous solvent system characterised in that the composition contains 0.1-10% by weight of said ammonia or alkanolamine and 0.001 to 0.5% by weight of said cationic polymer;
said aqueous solvent system comprising water and optionally up to 10% by weight of an organic solvent which has a boiling point below 200°C at atmospheric pressure or has an evaporation rate greater than 0.01 times that of n-butyl acetate at 20°C;

the composition being substantially free of inorganic electrolyte and containing at most 0.5% by weight in total of surfactant and any other materials which do not boil below 200°C at atmospheric pressure, all the above percentages being based on the whole composition.
A composition according to claim 1 wherein the amount of cationic polymer is from 0.001 to 0.05% by weight.
A composition according to claim 1 or claim 2 containing from 0.001% to 0.2% of surfactant.
A composition according to claim 1, claim 2 or claim 3 wherein the cationic polymer has a molecular weight of at least 50,000, and has cationic groups on not more than 35% of its repeat units.
A composition according to any one of claims 1 to 4 containing at least 0.05% of the said organic solvent.
A composition according to claim 5 wherein the solvent has an alkyl group of up to five carbon atoms together with at least one hydroxyl group;
A composition according to claim 6 wherein the solvent is of formula:

R-OH

R-O-CH₂-CH₂-OH

or
wherein R is C₃ to C₅ alkyl.
A composition according to claim 6 wherein the solvent is a monohydric alcohol or a monoalkyl ether of a diol.
A composition according to claim 8 wherein the solvent is methoxy propanol or methoxy propoxy propanol.
A composition according to any one of the preceding claims wherein the alkanolamine is monoethanolamine.
Method of cleaning fixed, rigid, inanimate surfaces comprising applying thereto a composition of any one of the preceding claims.