TECHNICAL FIELD
[0001] The present invention relates to acidic liquid compositions for cleaning a variety
of hard surfaces such as hard surfaces found in around the house, such as bathrooms,
toilets, garages, driveways, basements, gardens, kitchens, etc. More specifically,
the thickened compositions of the present invention deliver good limescale removal
performance (i.e., removal of pure limescale deposits and/or limescale-containing
soils).
BACKGROUND OF THE INVENTION
[0002] Acidic liquid compositions for cleaning limescale from hard-surfaces have been disclosed
in the art. Limescale deposits, are formed due to the fact that tap water contains
a certain amount of solubilised ions, which upon water evaporation eventually deposit
as salts such as calcium carbonate on hard surfaces. The visible limescale deposits
result in an unaesthetic aspect of the surfaces. The limescale formation and deposition
phenomenon is even more acute in places where water is particularly hard. Furthermore,
limescale deposits are prone to combination with other types of soils, such as soap
scum or grease, and can lead to the formation of limescale-soil mixture deposits (limescale-containing
soils). The removal of limescale deposits and limescale-containing soils is herein
in general referred to as "limescale removal" or "removing limescale". For vertical
and inclined surfaces, a challenge is to keep the acidic liquid composition on the
surface sufficiently long in order to provide good limescale removal. This has been
achieved by adding a thickener to increase the viscosity of the liquid composition,
in order to provide improved cling of the composition to the vertical or inclined
surface. However, acidic cleaning compositions remove limescale deposits and limescale-containing
soils by decomposing the carbonate, contained within the limescale. A by-product of
this decomposition is carbon dioxide, which is released as a gas. The heightened viscosity
and foaming due to gas formation slows the migration of the acid to the interface
between the liquid and the surface. As a result, efficacy of limescale removal for
horizontal surfaces is reduced when the acidic liquid composition comprises a thickener.
[0003] Hence, a need remains for a thickened composition, which provides improved limescale
removal efficacy, and improved limescale-soil deposit removal, for vertical and inclined
surfaces, while also not inhibiting limescale removal for horizontal surfaces.
[0004] EP1509556 relates to thickened aqueous formulations containing cross-linked cationic polymers,
novel homo- and copolymers their production and their use as thickeners for household
formulations, especially for fabric softener applications.
EP0395282 relates to aqueous acidic solutions which are thickened by cationic polymer, the
polymer being added to the solution in the form of particles below 10 micron in size.
WO2011/100405 relates to fabric and household hard surface treatment compositions comprising a
mixture of cross-linked polyglycerol esters molecules each comprising at least two
polyglycerol ester moieties, a non-crosslinker moiety; and a crosslinker moiety; and
a carrier material.
WO 2013/0683 87 A1 relates to a thickener which can be obtained by inverse emulsion polymerization of
at least one water-soluble ethylenically unsaturated monomer comprising at least one
cationic monomer, at least one ethylenically unsaturated associative monomer, where
the temperature is kept constant during the inverse emulsion polymerization and is
at least 40°C, and the activator is added after the inverse emulsion polymerization
in order to obtain the thickness.
WO2004/050815 A1 relates to aqueous compositions, preferably aqueous compositions comprising home-
and/or copolymers.
WO99/06455 A1 relates to thickening agents for acidic aqueous compositions.
SUMMARY OF THE INVENTION
[0005] The present invention relates to a liquid acidic hard surface cleaning composition
having a pH of from 0.1 to 6.5 and at least 0.5 wt% of organic acid, wherein the composition
further comprises a thickener, the thickener comprising a cationic cross-linked thickening
polymer, wherein the cationic cross-linked thickening polymer comprises monomers of:

wherein: R
4 is hydrogen or methyl, preferably methyl; R
2 is hydrogen, or C
1 - C
4 alkyl, preferably hydrogen, R
3 is C
1 - C
4 alkyl, preferably C
2 alkyl; R
4, R
5, and R
6 are each independently chosen from hydrogen, or C
1 - C
4 alkyl, preferably C
1 - C
4 alkyl, more preferably methyl; X is chosen from -O-, or -NH-, preferably -O-; and
Y is a halide, hydrogensulfate or methosulfate, preferably a halide, more preferably
chloride; and comprises monomers of:

wherein: R
7 is from hydrogen or methyl, preferably hydrogen; R
8 is hydrogen or C
1 - C
4 alkyl, preferably hydrogen, and R
9 and R
10 are each independently hydrogen or C
1-C
4 alkyl, preferably hydrogen or methyl.
DETAILED DESCRIPTION OF THE INVENTION
[0006] The present compositions, comprising the crosslinked thickening polymer, provide
sufficient cling to deliver good limescale removal on vertical and inclined surfaces,
while also providing improved limescale removal on horizontal surfaces.
[0007] As defined herein, "essentially free of' a component means that no amount of that
component is deliberately incorporated into the composition. Preferably, "essentially
free of' a component means that no amount of that component is present in the composition.
[0008] As defined herein, "stable" means that no visible phase separation is observed for
a premix kept at 25°C for a period of at least two weeks, or at least four weeks,
or greater than a month or greater than four months, as measured using the Floc Formation
Test, described in USPA
2008/0263780 A1.
[0009] All percentages, ratios and proportions used herein are by weight percent of the
composition, unless otherwise specified. All average values are calculated "by weight"
of the composition, unless otherwise expressly indicated.
[0010] All ratios are calculated as a weight/weight level of the active material, unless
otherwise specified. All measurements are performed at 25°C unless otherwise specified.
[0011] Unless otherwise noted, all component or composition levels are in reference to the
active portion of that component or composition, and are exclusive of impurities,
for example, residual solvents or by-products, which may be present in commercially
available sources of such components or compositions.
The liquid acidic hard surface cleaning composition
[0012] The compositions according to the present invention are designed as hard surfaces
cleaners. The compositions according to the present invention are liquid compositions
(including gels) as opposed to a solid or a gas.
[0013] The liquid acidic hard surface cleaning compositions according to the present invention
are preferably aqueous compositions. Therefore, they may comprise from 70% to 99%
by weight of the total composition of water, preferably from 75% to 95% and more preferably
from 80% to 95%.
[0014] The liquid compositions of the present invention are acidic. Therefore, they have
a pH of less than 6.5. Preferably, the composition has a pH of from 1 to 6, more preferably
from 2.0 to 2.5, still more preferably from 2.1 to 2.5, and most preferably from 2.1
to 2.4. The pH of the cleaning compositions is measured at 25°C.
[0015] Thus, the compositions comprise an acid system. Typically, the acid system may comprise
any organic or inorganic acid well-known to those skilled in the art, or a mixture
thereof. In preferred embodiments, the acid system comprises acids selected from the
group consisting of: citric acid, formic acid, acetic acid, maleic acid, lactic acid,
glycolic acid, succinic acid, glutaric acid, adipic acid, sulphamic acid, sulphuric
acid, hydrochloric acid, phosphoric acid, nitric acid, methane sulphonic acid, oxalic
acid and mixtures thereof, preferably acids selected from the group consisting of:
citric acid, formic acid, acetic acid, lactic acid, phosphoric acid, oxalic acid and
mixtures thereof.
[0016] In more preferred embodiments, the composition comprises an organic acid system,
more preferably selected from the group consisting of: citric acid, formic acid, acetic
acid, maleic acid, lactic acid, glycolic acid, succinic acid, glutaric acid, adipic
acid, methane sulphonic acid, oxalic acid and mixtures thereof. More preferably, the
organic acid system is selected from the group consisting of: citric acid, formic
acid, oxalic acid, lactic acid and mixtures thereof.
[0017] The composition preferably comprises the organic acid system at a level of from 0.5
% to 15%, preferably from 0.5% to 10%, more preferably from 2% to 8%, most preferably
from 4% to 7.5% by weight of the total composition.
[0018] Formic acid has been found to provide excellent limescale removal performance, in
combination with improved surface safety, especially for surfaces which are prone
to corrosion. For improved surface safety, especially of more delicate surfaces, the
composition preferably comprises formic acid as part of the acid system. In order
to achieve the desired pH, the compositions of the present invention may comprise
from 0.01% to 15%, preferably from 0.5% to 10%, more preferably from 1% to 8%, even
more preferably from 1% to 6%, still more preferably 1% to 4%, yet more preferably
1% to 3%, yet still more preferably 2% to 3% by weight of the total composition of
formic acid.
[0019] Lactic acid can be used as part of the acid system, especially where antimicrobial
or disinfecting benefits are desired. Such compositions may comprise up to 10% by
weight of the total composition of lactic acid, preferably from 0.1% to 6%, more preferably
from 0.2% to 4%, even more preferably from 0.2% to 3%, and most preferably from 0.5%
to 2%.
[0020] The compositions of the present invention may comprise from 0.1 to 30%, preferably
from 2% to 20%, more preferably from 3% to 15%, most preferably from 3% to 10% by
weight of the total composition of acetic acid. Alternatively, the compositions of
the present invention may comprise from 0.1 to 5%, preferably from 0.1% to 3%, more
preferably from 0.1% to 2%, most preferably from 0.5% to 2% by weight of the total
composition of acetic acid.
[0021] The compositions of the present invention may comprise from 0.1 to 30%, preferably
from 1% to 20%, more preferably from 1.5% to 15%, most preferably from 2% to 10% by
weight of the total composition of citric acid.
[0022] The compositions herein can comprise an alkaline material. The alkaline material
may be present to trim the pH and/or maintain the pH of the compositions according
to the present invention. Examples of alkaline material are sodium hydroxide, potassium
hydroxide and/or lithium hydroxide, and/or the alkali metal oxides such, as sodium
and/or potassium oxide or mixtures thereof and/or monoethanolamine and/or triethanolamine.
Other suitable bases include ammonia, ammonium carbonate, choline base, etc. Preferably,
source of alkalinity is sodium hydroxide or potassium hydroxide, preferably sodium
hydroxide.
[0023] Typically the amount of alkaline material is of from 0.001 % to 20 % by weight, preferably
from 0.01 % to 10 % and more preferably from 0.05 % to 3 % by weight of the composition.
[0024] Despite the presence of alkaline material, if any, the compositions herein would
remain acidic compositions.
[0025] The compositions herein are thickened compositions. Thus, the liquid acidic hard
surface cleaning compositions herein preferably have a viscosity of from 5 cps to
1000 cps at 10 s
-1, more preferably from 20 cps to 750 cps. For acidic cleaning compositions which are
typically poured onto the surface from the container, the viscosity is preferably
from 50 cps to 500 cps and most preferably from 100 cps to 350 cps at 10 s
-1 and 20°C. For acidic cleaning compositions which are typically sprayed onto the surface,
the viscosity is preferably from 5 cps to 100 cps at 10 s
-1 and 20°C. The viscosity is measured with a Rheometer, model AR 1000 (Supplied by
TA Instruments) with a 4 cm conic spindle in stainless steal, 2° angle (linear increment
from 0.1 to 100 sec
-1 in max. 8 minutes).
Thickener:
[0026] The acidic cleaning composition comprises a thickener, wherein the thickener comprises
a cationic cross-linked thickening polymer.
[0027] The cationic cross-linked thickening polymers comprises monomers of:

wherein:
R1 is hydrogen or methyl, preferably methyl,
R2 is hydrogen, or C1 - C4 alkyl, preferably hydrogen,
R3 is C1 - C4 alkyl, preferably C2 alkyl, R4, R5, and R6 are each independently chosen from hydrogen, or
C1 - C4 alkyl, preferably C1 - C4 alkyl, more preferably methyl,
X is chosen from -O-, or -NH-, preferably -O-, and
Y is a halide, hydrogensulfate or methosulfate, preferably a halide, more preferably
chloride;
and monomers of:

wherein:
R7 is from hydrogen or methyl, preferably hydrogen;
R8 is hydrogen or C1 - C4 alkyl, preferably hydrogen; and
R9 and R10 are each independently hydrogen or C1-C4 alkyl, preferably hydrogen or methyl.
[0028] Cross-linking can be achieved using any suitable cross-linking agent, such as N,N'-methylenebis(acrylamide)
(MBA), tetraallylammonium chloride (TAAC), pentaerythritol triacrylate (PETIA), and
mixtures thereof. Tetraallylammonium chloride (TAAC), N,N'-methylenebis(acrylamide)
(MBA), and combinations oftetraallylammonium chloride (TAAC) with N,N'-methylenebis(acrylamide)
(MBA) are preferred. The cross-linking agent is typically added at a level of from
50ppm to 1000 ppm, preferably from 300 ppm to 900 ppm.
[0029] The cationic cross-linked thickening polymer preferably has a molecular weight of
at least 500,000 Daltons, preferably at least 1,000,000 Daltons, more preferably at
least 2,000,000 Daltons. The cationic cross-linked thickening polymer typically has
a broad polydispersity which makes the upper limit to the molecular weight less relevant
for the performance of the polymer. Chain transfer agents can be used to increase
the molecular weight of the cross-linked thickening polymer. Suitable chain transfer
agents include mercaptanes, malic acid, lactic acid, formic add, isopropanol and hypophosphites,
and mixtures thereof. Formic acid is preferred. The chain transfer agent can be added
at a level of from 100 ppm to 5,000 ppm, preferably from 2,000 ppm to 2,500 ppm.
[0030] The cationic cross-linked thickening polymer can comprise at least 30 mol%, preferably
at least 60 mol%, more preferably at least 85 mol% of monomers according to formula
I.
[0031] Two or more monomer species are used, the resultant cationic cross-linked thickening
polymer is a copolymer. The cationic cross-linked thickening polymer is a copolymer
where combinations of monomers of formula I and formula II are used, in addition to
the cross-linking agent and chain transfer agent. The monomers can be used in any
suitable ratio. When the copolymer comprises combinations of monomers of formula I
and formula II, the monomers are preferably present in a ratio of from 95:5 to 30:80,
preferably from 90:10 to 60:40 of monomers of formula I to formula II. In preferred
embodiments, the monomer of formula I is ethanaminium, N,N,N-trimethyl-2-((2-methyl-1-oxo-2-propenyl)oxy)-,
chloride (CAS 26161-33-1), and the monomer of formula II is acrylamide (CAS 79-06-01)
or methacrylamide (CAS 79-39-0). Suitable cationic cross-linked thickening copolymers
include Flosoft® FS222, supplied by SNF Floerger.
[0032] The cationic cross-linked thickening polymer can comprise exclusively monomers of
formula I and formula II.
[0033] The cationic cross-linked thickening polymer may be prepared as water in oil emulsions,
wherein the cross-linked polymers are dispersed in the oil, preferably a mineral oil.
[0034] The cationic cross-linked thickening polymer can be present at a level of from 0.01%
to 5.0% by weight of the total composition of the cationic cross-linked thickener,
preferably from 0.1% to 2.5%, more preferably from 0.2% to 1.5% and most preferably
from 0.3% to 0.75%. Comparative cationic cross-linked thickening polymers include
a homopolymer where exclusively monomers of formula I are used, in addition to the
cross-linking agent and chain transfer agent. Such cationic cross-linked thickening
homopolymers are derived from monomers of ethanaminium, N,N,N-trimethyl-2-((2-methyl-1-oxo-2-propenyl)oxy)-,
chloride (CAS 26161-33-1). Such comparative cationic cross-linked thickening homopolymers
include Rheovis CDE, supplied by BASF.
Optional ingredients
[0035] The compositions according to the present invention may comprise a variety of optional
ingredients depending on the technical benefit aimed for and the surface treated.
[0036] Suitable optional ingredients for use herein include other acids, preferably acetic
acid and/or lactic acid and/or citric acid, chelating agents, nonionic surfactants,
vinylpyrrolidone homopolymer or copolymer, polysaccharide polymer, radical scavengers,
perfumes, solvents, other surfactants, builders, buffers, bactericides, hydrotropes,
colorants, stabilizers, bleaches, bleach activators, suds controlling agents like
fatty acids, enzymes, soil suspenders, brighteners, anti dusting agents, dispersants,
pigments, and dyes.
Nonionic surfactant
[0037] The compositions of the present invention preferably comprise a nonionic surfactant,
or a mixture thereof. This class of surfactants may be desired as it further contributes
to cleaning performance of the hard surface cleaning compositions herein. It has been
found in particular that nonionic surfactants strongly contribute in achieving highly
improved performance on greasy soap scum removal.
[0038] The compositions according to the present invention may comprise up to 15% by weight
of the total composition of a nonionic surfactant or a mixture thereof, preferably
from 0.1% to 10%, more preferably from 0.5% to 5%, even more preferably from 1.0%
to 3% by weight of the total composition.
[0039] Suitable nonionic surfactants for use herein are alkoxylated alcohol nonionic surfactants,
which can be readily made by condensation processes which are well-known in the art.
However, a great variety of such alkoxylated alcohols, especially ethoxylated and/or
propoxylated alcohols, is conveniently commercially available. Surfactants catalogs
are available which list a number of surfactants, including nonionics.
[0040] Accordingly, preferred alkoxylated alcohols for use herein are nonionic surfactants
according to the formula RO(E)e(P)pH where R is a hydrocarbon chain of from 2 to 24
carbon atoms, E is ethylene oxide and P is propylene oxide, and e and p which represent
the average degree of, respectively ethoxylation and propoxylation, are of from 0
to 24 (with the sum of e + p being at least 1). Preferably, the hydrophobic moiety
of the nonionic compound can be a primary or secondary, straight or branched alcohol
having from 8 to 24 carbon atoms.
[0041] Preferred nonionic surfactants for use in the compositions according to the invention
are the condensation product of ethylene and/or propylene oxide with an alcohol having
a straight alkyl chain comprising from 6 to 22 carbon atoms, wherein the degree of
ethoxylation/propoxylation is from 1 to 15, preferably from 5 to 12 or mixtures thereof.
Such suitable nonionic surfactants are commercially available from Shell, for instance,
under the trade name Neodol® or from BASF under the trade name Lutensol®.
Vinylpyrrolidone homopolymer or copolymer
[0042] In order to provide improved shine over a wider range of surfaces, the compositions
of the present invention may comprise a vinylpyrrolidone homopolymer or copolymer,
or a mixture thereof. Typically, the compositions of the present invention may comprise
from 0.01% to 5% by weight of the total composition of a vinylpyrrolidone homopolymer
or copolymer, or a mixture thereof, more preferably from 0.05% to 3% and most preferably
from 0.05% to 1%.
[0043] Suitable vinylpyrrolidone homopolymers for use herein are homopolymers of N-vinylpyrrolidone
having the following repeating monomer:

wherein n (degree of polymerisation) is an integer of from 10 to 1,000,000, preferably
from 20 to 100,000, and more preferably from 20 to 10,000.
[0044] Accordingly, suitable vinylpyrrolidone homopolymers ("PVP") for use herein have an
average molecular weight of from 1,000 to 10,000,000, preferably from 5,000 to 1,000,000,
and more preferably from 50,000 to 500,000.
[0045] Suitable vinylpyrrolidone homopolymers are commercially available from ISP Corporation,
New York, NY and Montreal, Canada under the product names PVP K-15® (viscosity molecular
weight of 10,000), PVP K-30® (average molecular weight of 40,000), PVP K-60® (average
molecular weight of 160,000), and PVP K-90® (average molecular weight of 360,000).
Other suitable vinylpyrrolidone homopolymers which are commercially available from
BASF Cooperation include Sokalan HP 165®, Sokalan HP 12®, Luviskol K30®, Luviskol
K60®, Luviskol K80®, Luviskol K90®; vinylpyrrolidone homopolymers known to persons
skilled in the detergent field (see for example
EP-A-262,897 and
EP-A-256,696).
[0046] Suitable copolymers of vinylpyrrolidone for use herein include copolymers of N-vinylpyrrolidone
and alkylenically unsaturated monomers or mixtures thereof.
[0047] The alkylenically unsaturated monomers of the copolymers herein include unsaturated
dicarboxylic acids such as maleic acid, chloromaleic acid, fumaric acid, itaconic
acid, citraconic acid, phenylmaleic acid, aconitic acid, acrylic acid, N-vinylimidazole
and vinyl acetate. Any of the anhydrides of the unsaturated acids may be employed,
for example acrylate, methacrylate. Aromatic monomers like styrene, sulphonated styrene,
alpha-methyl styrene, vinyl toluene, t-butyl styrene and similar well known monomers
may be used.
[0048] Particularly suitable N-vinylimidazole N-vinylpyrrolidone polymers for use herein
have an average molecular weight range from 5,000 to 1,000,000, preferably from 5,000
to 500,000, and more preferably from 10,000 to 200,000. The average molecular weight
range was determined by light scattering as described in
Barth H. G. and Mays J. W. Chemical Analysis Vol 113,"Modern Methods of Polymer Characterization".
[0049] Such copolymers of N-vinylpyrrolidone and alkylenically unsaturated monomers like
PVP/vinyl acetate copolymers are commercially available under the trade name Luviskol®
series from BASF.
[0050] According to a very preferred execution of the present invention, vinylpyrrolidone
homopolymers are advantageously selected.
Chelating agent
[0051] The compositions of the present invention may comprise a chelating agent or mixtures
thereof, as a preferred optional ingredient. Chelating agents can be incorporated
in the compositions herein in amounts ranging from 0% to 10% by weight of the total
composition, preferably 0.01% to 5.0%, more preferably 0.05% to 1%.
[0052] Suitable phosphonate chelating agents to be used herein may include alkali metal
ethane 1-hydroxy diphosphonates (HEDP), alkylene poly (alkylene phosphonate), as well
as amino phosphonate compounds, including amino aminotri(methylene phosphonic acid)
(ATMP), nitrilo trimethylene phosphonates (NTP), ethylene diamine tetra methylene
phosphonates, and diethylene triamine penta methylene phosphonates (DTPMP). The phosphonate
compounds may be present either in their acid form or as salts of different cations
on some or all of their acid functionalities. Preferred chelating agents to be used
herein are diethylene triamine penta methylene phosphonate (DTPMP) and ethane 1-hydroxy
diphosphonate (HEDP). In a particularly preferred execution of the present invention,
the chelating agent is selected to be ethane 1-hydroxy diphosphonate (HEDP). Such
phosphonate chelating agents are commercially available from Monsanto under the trade
name DEQUEST®.
[0053] Polyfunctionally-substituted aromatic chelating agents may also be useful in the
compositions herein. See
U.S. patent 3,812,044, issued May 21, 1974, to Connor et al. Preferred compounds of this type in acid form are dihydroxydisulfobenzenes such as
1,2-dihydroxy -3,5-disulfobenzene. A preferred biodegradable chelating agent for use
herein is ethylene diamine N,N'- disuccinic acid, or alkali metal, or alkaline earth,
ammonium or substitutes ammonium salts thereof or mixtures thereof. Ethylenediamine
N,N'- disuccinic acids, especially the (S,S) isomer have been extensively described
in
US patent 4, 704, 233, November 3, 1987, to Hartman and Perkins. Ethylenediamine N,N'- disuccinic acids is, for instance, commercially available
under the tradename ssEDDS® from Palmer Research Laboratories.
[0054] Suitable amino carboxylates to be used herein include tetra sodium glutamate diacetate
(GLDA), ethylene diamine tetra acetates, diethylene triamine pentaacetates, diethylene
triamine pentaacetate (DTPA), N- hydroxyethylethylenediamine triacetates, nitrilotri-acetates,
ethylenediamine tetrapropionates, triethylenetetraaminehexa-acetates, ethanol-diglycines,
propylene diamine tetracetic acid (PDTA) and methyl glycine di-acetic acid (MGDA),
both in their acid form, or in their alkali metal, ammonium, and substituted ammonium
salt forms. Particularly suitable amino carboxylates to be used herein are diethylene
triamine penta acetic acid, propylene diamine tetracetic acid (PDTA) which is, for
instance, commercially available from BASF under the trade name Trilon FS® methyl
glycine di-acetic acid (MGDA), tetra sodium glutamate diacetate (GLDA) which is, for
instance, commercially available from AkzoNobel under the trade name Dissolvine® GL.
[0055] Further carboxylate chelating agents to be used herein include salicylic acid, aspartic
acid, glutamic acid, glycine, malonic acid or mixtures thereof.
[0056] The addition of a chelating agent, preferably HEDP, in the composition of the present
invention provides an unexpected improvement in terms of limescale removal.
Solvent
[0057] The compositions of the present invention may further comprise a solvent or a mixture
thereof, as an optional ingredient. Solvents to be used herein include all those known
to those skilled in the art of hard-surfaces cleaner compositions. In a highly preferred
embodiment, the compositions herein comprise an alkoxylated glycol ether (such as
n-Butoxy Propoxy Propanol (n-BPP)) or a mixture thereof.
[0058] Typically, the compositions of the present invention may comprise from 0.1% to 5%
by weight of the total composition of a solvent or mixtures thereof, preferably from
0.5% to 5% by weight of the total composition and more preferably from 1% to 3% by
weight of the total composition.
Additional surfactant
[0059] The compositions of the present invention may comprise an additional surfactant,
or mixtures thereof, on top of the nonionic surfactant already described herein. Additional
surfactants may be desired herein as they further contribute to the cleaning performance
and/or shine benefit of the compositions of the present invention. Surfactants to
be used herein include anionic surfactants, cationic surfactants, amphoteric surfactants,
zwitterionic surfactants, and mixtures thereof. Accordingly, the compositions according
to the present invention may comprise up to 15% by weight of the total composition
of another surfactant or a mixture thereof, on top of the nonionic surfactant already
described herein, more preferably from 0.5% to 5%, even more preferably from 0.5%
to 3%, and most preferably from 0.5% to 2%. Different surfactants may be used in the
present invention including anionic, cationic, zwitterionic or amphoteric surfactants.
It is also possible to use mixtures of such surfactants without departing from the
spirit of the present invention.
[0060] Preferred surfactants for use herein are anionic and zwitterionic surfactants since
they provide excellent grease soap scum cleaning ability to the compositions of the
present invention.
[0061] Anionic surfactants may be included herein as they contribute to the cleaning benefits
of the hard-surface cleaning compositions of the present invention. Indeed, the presence
of an anionic surfactant contributes to the greasy soap scum cleaning of the compositions
herein. More generally, the presence of an anionic surfactant in the liquid acidic
compositions according to the present invention allows to lower the surface tension
and to improve the wettability of the surfaces being treated with the liquid acidic
compositions of the present invention. Furthermore, the anionic surfactant, or a mixture
thereof, helps to solubilize the soils in the compositions of the present invention.
[0062] Suitable anionic surfactants for use herein are all those commonly known by those
skilled in the art. Preferably, the anionic surfactants for use herein include alkyl
sulphonates, alkyl aryl sulphonates, or mixtures thereof.
[0063] Particularly suitable linear alkyl sulphonates include C8 sulphonate like Witconate®
NAS 8 commercially available from Witco.
[0064] Other anionic surfactants useful herein include salts (including, for example, sodium,
potassium, ammonium, and substituted ammonium salts such as mono-, di- and triethanolamine
salts) of soap, alkyl sulphates, alkyl aryl sulphates alkyl alkoxylated sulphates,
C8-C24 olefinsulfonates, sulphonated polycarboxylic acids prepared by sulphonation
of the pyrolyzed product of alkaline earth metal citrates, e.g., as described in British
patent specification No.
1,082,179; alkyl ester sulfonates such as C14-16 methyl ester sulfonates; acyl glycerol sulfonates,
alkyl phosphates, isethionates such as the acyl isethionates, N-acyl taurates, alkyl
succinamates, acyl sarcosinates, sulfates of alkylpolysaccharides such as the sulfates
of alkylpolyglucoside (the nonionic nonsulfated compounds being described below),
alkyl polyethoxy carboxylates such as those of the formula RO(CH2CH2O)kCH2COO-M+ wherein
R is a C8-C22 alkyl, k is an integer from 0 to 10, and M is a soluble salt-forming
cation. Resin acids and hydrogenated resin acids are also suitable, such as rosin,
hydrogenated rosin, and resin acids and hydrogenated resin acids present in or derived
from tall oil. Further examples are given in "Surface Active Agents and Detergents"
(Vol. I and II by Schwartz, Perry and Berch). A variety of such surfactants are also
generally disclosed in
U.S. Patent 3,929,678, issued December 30, 1975 to Laughlin, et al. at Column 23, line 58 through Column 29, line 23.
[0065] Suitable zwitterionic surfactants for use herein contain both basic and acidic groups
which form an inner salt giving both cationic and anionic hydrophilic groups on the
same molecule at a relatively wide range of pH's. The typical cationic group is a
quaternary ammonium group, although other positively charged groups like phosphonium,
imidazolium and sulfonium groups can be used. The typical anionic hydrophilic groups
are carboxylates and sulfonates, although other groups like sulfates, phosphonates,
and the like can be used.
[0067] For example Coconut dimethyl betaine is commercially available from Seppic under
the trade name of Amonyl 265®. Lauryl betaine is commercially available from Albright
& Wilson under the trade name Empigen BB/L®. A further example of betaine is Lauryl-immino-dipropionate
commercially available from Rhodia under the trade name Mirataine H2C-HA®.
[0068] Particularly preferred zwitterionic surfactants for use in the compositions of the
present invention are the sulfobetaine surfactants as they deliver optimum soap scum
cleaning benefits.
[0069] Examples of particularly suitable sulfobetaine surfactants include tallow bis(hydroxyethyl)
sulphobetaine, cocoamido propyl hydroxy sulphobetaines which are commercially available
from Rhodia and Witco, under the trade name of Mirataine CBS® and Rewoteric AM CAS
15® respectively.
[0070] Amphoteric and ampholytic detergents which can be either cationic or anionic depending
upon the pH of the system are represented by detergents such as dodecylbeta-alanine,
N-alkyltaurines such as the one prepared by reacting dodecylamine with sodium isethionate
according to the teaching of
U.S. Pat. No. 2,658,072, N-higher alkylaspartic acids such as those produced according to the teaching of
U.S. Pat. No. 2,438,091, and the products sold under the trade name "Miranol", and described in
U.S. Pat. No. 2,528,378. Additional synthetic detergents and listings of their commercial sources can be
found in McCutcheon's Detergents and Emulsifiers, North American Ed. 1980.
[0071] Suitable amphoteric surfactants include the amine oxides. Examples of amine oxides
for use herein are for instance coconut dimethyl amine oxides, C12-C16 dimethyl amine
oxides. Said amine oxides may be commercially available from Clariant, Stepan, and
AKZO (under the trade name Aromox®). Other suitable amphoteric surfactants for the
purpose of the invention are the phosphine or sulfoxide surfactants.
[0072] Cationic surfactants suitable for use in compositions of the present invention are
those having a long-chain hydrocarbyl group. Examples of such cationic surfactants
include the quaternary ammonium surfactants such as alkyldimethylammonium halogenides.
Other cationic surfactants useful herein are also described in
U.S. Patent 4,228,044, Cambre, issued October 14, 1980.
The process of cleaning a hard-surface or an object
[0073] The cross-linked thickening polymers described herein are particularly useful in
acidic cleaning compositions for processes for providing improved limescale removal,
and improved limescale-soil deposit removal, especially on horizontal surfaces.
[0074] Such processes can comprise the steps of: applying the liquid acidic hard surface
cleaning composition onto said hard-surface or said object; leaving said composition
on said hard-surface or said object to act; optionally wiping said hard-surface or
object and/or providing mechanical agitation, and then rinsing said hard-surface or
said object.
[0075] The compositions according to the present invention are particularly suitable for
treating hard-surfaces located in and around the house, such as in bathrooms, toilets,
garages, on driveways, basements, gardens, kitchens, etc., and preferably in bathrooms.
It is however known that such surfaces (especially bathroom surfaces) may be soiled
by the so-called "limescale-containing soils". By "limescale-containing soils" it
is meant herein any soil which contains not only limescale mineral deposits, such
as calcium and/or magnesium carbonate, but also soap scum (e.g., calcium stearate)
and other grease (e.g. body grease). By "limescale deposits" it is mean herein any
pure limescale soil, i.e., any soil or stains composed essentially of mineral deposits,
such as calcium and/or magnesium carbonate.
[0076] By "hard-surface", it is meant herein any kind of surfaces typically found in and
around houses like bathrooms, kitchens, basements and garages, e.g., floors, walls,
tiles, windows, sinks, showers, shower plastified curtains, wash basins, WCs, dishes,
fixtures and fittings and the like made of different materials like ceramic, enamel,
painted and un-painted concrete, plaster, bricks, vinyl, no-wax vinyl, linoleum, melamine,
Formica®, glass, any plastics, metals, chromed surface and the like. The term surfaces
as used herein also include household appliances including, but not limited to, washing
machines, automatic dryers, refrigerators, freezers, ovens, microwave ovens, dishwashers
and so on. Preferred hard surfaces cleaned with the liquid aqueous acidic hard surface
cleaning composition herein are those located in a bathroom, in a toilet or in a kitchen,
basements, garages as well as outdoor such as garden furniture, gardening equipments,
driveways etc.
[0077] The objects herein are objects that are subjected to limescale formation thereon.
Such objects may be water-taps or parts thereof, water-valves, metal objects, objects
made of stainless-steel, cutlery and the like.
[0078] The preferred process of cleaning a hard-surface or an object (preferably removing
limescale from said hard-surface or said object) comprises the step of applying a
composition according to the present invention onto said hard-surface or object, leaving
said composition on said hard-surface or object to act, preferably for an effective
amount of time, more preferably for a period comprised between 10 seconds and 10 minutes,
most preferably for a period comprised between 15 seconds and 4 minutes; optionally
wiping said hard-surface or object with an appropriate instrument, e.g. a sponge;
and then preferably rinsing said surface with water.
[0079] Even though said hard-surface or object may optionally be wiped and/or agitated during
the process herein, it has been surprisingly found that the process of the present
invention allows good limescale removal performance without any additional mechanical
wiping and/or agitation action. The lack of need for additional wiping and/or mechanical;
agitation provides an added convenience for the user of the compositions herein.
[0080] Moreover, the processes described herein allow good removal of limescale- soap mixture
depositions (such as greasy soap scum) with only moderate mechanical wiping and/or
agitation action.
[0081] The compositions of the present invention may be contacted to the surface or the
object to be treated in its neat form or in its diluted form. Preferably, the composition
is applied in its neat form.
[0082] By "diluted form", it is meant herein that said composition is diluted by the user,
typically with water. The composition is diluted prior use to a typical dilution level
of 10 to 400 times its weight of water, preferably from 10 to 200 and more preferably
from 10 to 100. Usual recommended dilution level is a 1.2% dilution of the composition
in water.
[0083] The compositions herein may be packaged in any suitable container, such as bottles,
preferably plastic bottles, optionally equipped with an electrical or manual trigger
spray-head.
Methods:
A) pH measurement:
[0084] The pH is measured on the neat composition, at 25°C, using a Sartarius PT-10P pH
meter with gel-filled probe (such as the Toledo probe, part number 52 000 100), calibrated
according to the instructions manual.
B) Limescale removal:
[0085] Limescale removal is measured using a gravimetric method quantifying the weight loss
of a marble chip (calcium carbonate, 2.0 cm x 2.0 cm x 0.5 cm blocks of Carrara, supplied
by Crombé Haachtsesteenweg 1465, 1130 Brussel) after immersion in the product.
[0086] The marble chip is thoroughly cleaned with demineralised water and put in a pre-heated
oven (105°C) (WTC Binder Type Series M240 or IP20, temperature range 20-250°C. Precision
±0.75%) for 15 minutes. The marble chip is then taken out of the oven and left for
15 minutes in a constant humidity cabinet at 25°C, 70% RH (Climatic Control Cabinet
from HERAEUS Belgium Type HC0033 (3302)). After 15 minutes of cooling down, each marble
chip is weighed (initial weight) using an analytical balance (precision ±0.1mg).
[0087] A plastic cup (Ava papierwaren, model nr. 2 CR) is filled with 20 grams of test product.
The marble chip is immersed in the cup for 5 minutes. The marble chip is then taken
out of the cup and rinsed thoroughly with demineralised water. The chip is then dried
in the oven at 105°C for 15 minutes and then transferred to the humidity cabinet for
15 minutes (25°C, 70%RH). After 15 minutes of cooling down, the marble chip is weighed
(final weight). The weight lost (final weight - initial weight) represents the limescale
removed in mg of Calcium carbonate. The test is repeated a total of 5 times and the
result averaged. The results are presented as an index vs the reference (index 100).
EXAMPLES:
[0088] These following compositions were made comprising the listed ingredients in the listed
proportions (active weight %). Example 1 is a composition of the present invention,
comprising Rheovis CDE as the thickening polymer, while examples A to C are comparative
compositions which comprised either chitosan, a linear cationic thickener, or Xanthan
gum, an anionic thickener.
[0089] The relative limescale removale was assessed using the procedure described earlier.
Composition |
Ex 1 of invention |
Ex 2 (Comp) |
Ex A (Comp) |
Ex B (Comp) |
Ex C (Comp) |
|
wt% |
wt% |
wt% |
wt% |
wt% |
Citric acid |
4.2 |
4.2 |
4.2 |
4.2 |
4.2 |
Formic acid |
2.7 |
2.7 |
2.7 |
2.7 |
2.7 |
C9-C11 8E01 |
2.2 |
2.2 |
2.2 |
2.2 |
2.2 |
Sodium Hydroxide |
0.25 |
0.25 |
0.25 |
0.25 |
0.25 |
Flosoft® FS2222 |
0.47 |
- |
- |
- |
- |
Rheovis® CDE3 |
- |
0.73 |
- |
- |
- |
Chitosan4 |
- |
- |
0.5 |
- |
- |
Xantham gum5 |
- |
- |
- |
0.25 |
0.1 |
Perfume |
0.2 |
0.2 |
0.2 |
0.2 |
0.2 |
Dyes |
0.00781 |
0.00781 |
0.00781 |
0.00781 |
0.00781 |
Polyvinylpyrrolidone (PVP)6 |
0.025 |
0.025 |
0.025 |
0.025 |
0.025 |
Water |
Balance up to 100 |
Balance up to 100 |
Balance up to 100 |
Balance up to 100 |
Balance up to 100 |
pH |
2.2 |
2.2 |
2.2 |
2.2 |
2.2 |
Viscosity at 10s-1 |
160 |
148 |
135 |
142 |
22 |
Limescale removal |
230 |
193 |
188 |
100 |
185 |
(mg CaCO3 removed - index vs. Ex B) |
|
|
|
|
|
1 Nonionic surfactant, sourced as Neodol® 91-8 from Shell.
2 Cationic cross-linked thickener of use in the present invention, supplied by SNF
Floerger
3 Cationic cross-linked thickener of use in the present invention, supplied by BASF
4 Cationic linear thickener supplied by i-chess chemicals Pvt Ltd, under the tradename
Cee'san TH®
5 Kelzan T® is a Xanthan gum supplied by Kelco.
6 Polyvinylpyrrolidone, sourced as PVP K-60 from Ashland Inc. |
[0090] As can be seen from the test results, the compositions comprising the cationic cross-linked
thickener (examples 1 and comparative example 2) provide improved lime-scale removal,
at similar viscosities, when compared to either non-cross-linked cationic thickener
(chitosan) or Xantham gum (comparative examples A and B). Indeed, the inventive compositions
provide improved limescale removal even when compared to compositions comprising lower
levels of Xanthan gum, having a much lower viscosity (comparative example C).
[0091] Flosoft® FS222 is a cationic cross-linked thickening polymer comprising monomers
of formula I and formula II, with at least 85 mol% of monomer of formula I. Rheovis®
CDE is a cationic cross-linked thickening polymer which is a homopolymer of monomers
of formula I. As can be seen from comparing the limescale removal of example 1 with
that of comparative example 2, compositions comprising cationic cross-linked thickening
polymers comprising both monomers of formula I and formula II provide further improved
limescale removal, even at higher viscosities.
Examples 3 to 11 are further examples of compositions of the present invention.
Examples: |
3 |
4 |
5 |
6 |
7 |
8* |
9* |
10 |
11 |
Acids |
Formic acid |
1 |
2.7 |
2.7 |
1 |
1 |
2.7 |
2.7 |
2.7 |
3 |
Acetic acid |
1 |
0 |
1 |
1 |
1 |
0 |
0 |
0 |
0 |
Citric acid |
1 |
1.7 |
4 |
1 |
1 |
1.7 |
1.7 |
4 |
0 |
Lactic acid |
1 |
0 |
0 |
1 |
1 |
0 |
0 |
0 |
0 |
Surfactants |
C9-C11 8E01 |
2.2 |
2.2 |
2.2 |
0 |
4 |
2.2 |
3 |
2.2 |
2 |
Thickener: |
Flosoft FS2222 |
0.6 |
0.47 |
0.47 |
0.47 |
0.47 |
0 |
0 |
0.1 |
0.47 |
Rheovis CDE3 |
0 |
0 |
0 |
0 |
0 |
0.5 |
0.5 |
0 |
0 |
Surface modification polymer: |
Polyvinylpyrrolidone (PVP)6 |
0.025 |
0.025 |
0.1 |
0.1 |
0.025 |
0.025 |
0.01 |
0.01 |
0.025 |
Misc.: |
Perfume |
0.2 |
0.2 |
0.2 |
0.2 |
0.2 |
0.2 |
0.2 |
0.2 |
0.2 |
Dye |
0.00781 |
0.00781 |
0.00781 |
0.00781 |
0.00781 |
0.00781 |
0.00781 |
0.00781 |
0.00781 |
Akaline Material: |
KOH - to pH : |
0 |
0 |
0 |
0 |
0 |
2.2 |
0 |
0 |
0 |
NaOH - to pH = |
2.2 |
2.2 |
2.2 |
2.2 |
2.2 |
0 |
2.2 |
2.2 |
2.2 |
Water: |
------------------------------ up to 100% ------------------------------ |
[0092] Formic acid, lactic acid and acetic acid are commercially available from Aldrich.
[0093] The dimensions and values disclosed herein are not to be understood as being strictly
limited to the exact numerical values recited. Instead, unless otherwise specified,
each such dimension is intended to mean both the recited value and a functionally
equivalent range surrounding that value. For example, a dimension disclosed as "40
mm" is intended to mean "about 40 mm."
1. A liquid acidic hard surface cleaning composition having a pH of from 0.1 to 6.5 and
at least 0.5 wt% of organic acid, wherein the composition further comprises a thickener,
the thickener comprising a cationic cross-linked thickening polymer,
wherein the cationic cross-linked thickening polymer comprises monomers of:

wherein:
R1 is hydrogen or methyl, preferably methyl,
R2 is hydrogen, or C1 - C4 alkyl, preferably hydrogen,
R3 is C1 - C4 alkyl, preferably C2 alkyl,
R4, R5, and R6 are each independently chosen from hydrogen, or C1 - C4 alkyl, preferably C1 - C4 alkyl, more preferably methyl,
X is chosen from -O-, or -NH-, preferably -O-, and
Y is a halide, hydrogensulfate or methosulfate, preferably a halide, more preferably
chloride;
and comprises monomers of:

wherein:
R7 is from hydrogen or methyl, preferably hydrogen,
R8 is hydrogen or C1 - C4 alkyl, preferably hydrogen, and
R
9 and R
10 are each independently hydrogen or C
1-C
4 alkyl, preferably hydrogen or methyl.
wherein the composition has a viscosity of from 5 cps to 1000 cps at 10 s
-1.
2. The composition according to claim 1, wherein the cationic cross-linked thickening
polymer comprises at least 30 mol%, preferably at least 60 mol%, more preferably at
least 85 mol% of monomers according to formula I.
3. The composition according to claim 1, wherein the monomers are present in a ratio
of from 95:5 to 30:80, preferably from 90:10 to 60:40 of monomers of formula I to
formula II.
4. The composition according to any of claims 1 or 2, wherein the monomer of formula
II is acrylamide (CAS 79-06-01) or methacrylamide.
5. The composition according to any preceding claim, wherein the monomer of formula I
is ethanaminium, N,N,N-trimethyl-2-((2-methyl-1-oxo-2-propenyl)oxy)-, chloride.
6. The composition according to any preceding claims, wherein the cationic cross-linked
thickening polymer is cross-linked using a cross-linking agent selected from the group
consisting of: N,N'-methylenebis(acrylamide) (MBA), tetraallylammonium chloride (TAAC),
pentaerythritol triacrylate (PETIA), and mixtures thereof, preferably from the group
consisting of: tetraallylammonium chloride (TAAC), N,N'-methylenebis(acrylamide) (MBA),
and mixtures thereof.
7. The composition according to any preceding claims, wherein the cationic cross-linked
thickening polymer has a molecular weight of greater than 500,000 Daltons, preferably
greater than 1,000,000 Daltons, more preferably greater than 2,000,000 Daltons.
8. The composition according to any of the preceding claims, wherein said composition
comprises from 0.01% to 5.0% by weight of the total composition of the cationic cross-linked
thickener, preferably from 0.1% to 2.5%, more preferably from 0.2% to 1.5% and most
preferably from 0.3% to 0.75%.
9. The composition according to any of the preceding claims, wherein said composition
has a pH of from 1 to 6, preferably 2.0 to 2.5, more preferably from 2.1 to 2.5, even
more preferably 2.1 to 2.4.
10. The composition according to any preceding claim, wherein said composition comprises
the organic acid at a level of from 0.5 % to 15%, preferably from 0.5% to 10%, more
preferably from 2% to 8%, most preferably from 4% to 7.5% by weight of the total composition.
11. The composition according to any of the preceding claims, wherein the composition
comprises an organic acid selected from the group consisting of: citric acid, formic
acid, acetic acid, maleic acid, lactic acid, glycolic acid, succinic acid, glutaric
acid, adipic acid, methane sulphonic acid, oxalic acid and mixtures thereof.
12. The composition according to any of the preceding claims, wherein said composition
further comprises an alkaline material, preferably selected from the group consisting
of sodium hydroxide, potassium hydroxide, lithium hydroxide, the alkali metal oxides
such, as sodium and/or potassium oxide or mixtures thereof, monoethanolamine, triethanolamine,
ammonia, ammonium carbonate and, choline base and mixtures thereof, most preferably
sodium hydroxide or potassium hydroxide.
13. The composition according to any of the preceding claims, wherein said composition
further comprises one or more nonionic surfactant, preferably a nonionic surfactant
which is the condensation product of ethylene and/or propylene oxide with an alcohol
having a straight alkyl chain comprising from 6 to 22 carbon atoms, wherein the degree
of ethoxylation/propoxylation is from 1 to 15, preferably from 5 to 12 or mixtures
thereof.