Note: Descriptions are shown in the official language in which they were submitted.
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ACID CLEANING COMPOSITIONS CONTAINING ALKOXYLATED AMINES AND THEIR USE
Tschaical gield
The present invention relates to acidic cleaning
compositions, and in particular to acidic antimicrobial
cleaning composition suitable for use on hard surfaces.
saclcQrouad to the Iaventioa
Many formulations have been proposed in the literature for
so-called 'descaler' compositions. These generally comprise
sufficient acid to give a low pH and may comprise a
thickening agent so as to cause the composition to cling to
and be retained on sloping surfaces, such as the inside of
toilet bowls. As described in more detail below, known
thickeners include both ethoxylated and unethoxylated
tertiary amines, either alone or in combination with a
hydrotrope. Known acids for use in such compositions
include sulphamic and phosphoric acids.
It is advantageous that such compositions should be
antimicrobial and that they should exhibit this
antimicrobial effect against a broad range of micro-
organisms. In order to achieve this various bactericides
have been proposed as additives to these compositions.
GB 1443244 relates to acid cleaners and descalers which
comprise as a thickening agent an ethoxylated tertiary
amine of which ETHOMEEN S12 (N,N-dihydroxyethyl-oleylamine)
is given as an example. The composition also comprises
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acids which are selected from mineral acids and acid salts
of strong inorganic acids such as sulphamic acid.
Bacteriocides are an additional, optional component.
FR 2459830 discloses compositions which comprise non-
ethoxylated and ethoxylated amines together with sulphamic
acid. The composition may also comprise disinfectants.
WO 95/27768 discloses cleaning compositions, particularly
intended for painted and plastic surfaces comprising
ethoxylated C10-C18 aliphatic amines containing 3-8 ethoxy
units (preferably 4-6) and C6-C10 carboxylic acids and/or
organic or inorganic chelating agents. The compositions are
not disclosed to have disinfecting properties.
AU-A-57022/86 relates to cleaning systems which comprise a
mixture of sulphamic and phosphoric acids and an acid
stable surfactant. Bacteriocides are optional and formalin
is disclosed as a bacteriocide which improves the
antibacterial effect of the acids.
EP-H-0276501 discloses thickened aqueous cleaning
compositions which comprise 0.1-50~wt of a weak acid having
a pK >2 (of which sulphamic is given as an example),
0.1-20~wt of an amine which can include 2~ of oleyl-
bis-(2-hydroxyethyl)-amine and 0.01-5~wt hydrotrope
(sodium xylenesulphonate is given as an example).
Disinfecting agents are optional.
EP-A-0314232 relates to compositions which undergo a
viscosity increase on dilution and discloses that thickened
liquid detergent compositions can be prepared with an amine
oxide, amine (such as ETHOMEEN S12~), betaine or
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quaternary ammonium compound and hydrotrope (sodium xylene-
sulphonate). It is stated in the specification that amine
oxides and quaternary ammonium compounds are known to have
biocidal properties and that further microbiocides
including organic peracids are optional. These compositions
can be of acidic, neutral or alkaline pH.
From the above it can be seen that while certain thickening
surfactants such as quaternary ammonium compounds and amine
oxides are known to have antibacterial properties it has
been comanonplace to suggest the addition of further
antimicrobial components to descaling compositions where
antimicrobial effects are desired in addition to descaling.
Brief Description of the Invention
We have determined that compositions which comprise both
alkoxylated aliphatic amines and sulphamic acid show an
improved antimicrobial effect. It is believed that this is
due to a synergistic interaction of these components and
that the effect is obtained irrespective of the presence
(i.e. also in the absence) of other antimicrobial species.
We have also determined that excellent scale removal and
disinfection is obtained with compositions which comprise:
a) an alkoxylated aliphatic amine,
b) sulphamic acid, and,
c) a source of peroxygen species.
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Detailed D~~cription of the =nveation
According to a first aspect of the present invention there
is provided the use of 0.01-l5~wt of an alkoxylated
aliphatic amine having an aliphatic hydrocarbon group of 8-
20 carbon atoms and 1-8 units of alkoxylation per mole of
amine to improve the antimicrobial effectiveness of an
acidic, antimicrobial composition comprising 0.01-l5~wt of
a sulphamic acid.
15
According to a second aspect of the present invention there
is provided an acidic, antimicrobial composition
comprising:
a) 0.01-l5~wt of an alkoxylated aliphatic amine with 8-20
carbon atoms and 1-8 units of alkoxylation;
b) 0.01-15$wt of a sulphamic acid, and
c) a source of peroxygen species.
According to a third aspect of the present invention there
is provided a method of disinfecting surfaces which
comprises the step of treating the surface with an acidic,
antimicrobial composition comprising:
a) 0.01-l5~wt of an alkoxylated aliphatic amine with 8-20
carbon atoms and 1-8 units of alkoxylation and
b) 0.01-l5~wt of sulphamic acid.
A~aines:
Typically, the alkoxylated aliphatic amine is a tertiary
amine of the general formula:
H (A) X N (R) - (A) yH
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wherein R is an alkyl or alkenyl group comprising 8-20
carbon atoms, A is an ethoxy or propoxy group and x and y
may be the same or different and are integers from 1-4.
Preferably R has 8-18, more preferably 10-l8 carbon atoms;
x and y are preferably 1-3, more preferably 1 or 2. The
preferred materials are ethoxylated amines wherein A is
-OCH2CH2-. In further preferred embodiments of the
invention R is C14-C18 alkyl or alkenyl and is e.g. derived
from oleic, palmitic or myristic acid.
Suitable ethoxylated aliphatic amines are e.g.:
- N,N-di(hydroxyethyl)-oleylamine which is available
from AKZO under the trademark ETHOMEEN 512;
- C12-C18 aliphatic amine ethoxylates containing 2 or 3
ethoxy groups, wherein between 20 and 40~ of the
aliphatic groups are unsaturated (i.e. R = C12-C18 20-
40~ unsaturated, x=1 and y = 1 or 2). An example of
such material is ETHOMEEN BTB/12~, which is also
available from AKZO and is a mixture of
N,N-di(hydroxyethyl) aliphatic amine derived from
fully hardened tallow and the oleyl derivative in a
65/35 ratio. Such a mixed material can be prepared by
synthesis using combined starting materials mixed in
the appropriate ratio, or obtained by mixing
commercially available materials such as ETHOMEEN
HT12~ and ETHOMEEN 512 in the desired ratio.
- C12-C16 alkyl amines containing 2 or (even more
preferably) 3 ethoxy groups (i.e. R = C12-C16 alkyl,
x=1 and y = 1 or preferably 2).
As can be seen from the above, particularly suitable
ethoxylated amines or mixtures of such amines are those
wherein the aliphatic group is predominantly (for more than
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50~) derived from C16 and C18 fatty acids and wherein
(average) x+y is 2-3
Preferred levels of the alkoxylated aliphatic amine are
1-l0~wt on product with levels of 2-6~wt on product being
particularly preferred.
Acids:
Typical levels of sulphamic acid (i.e. amino-sulphonic
acid) range from 1-l0~wt on product with levels of 2-6~ on
product being particularly preferred.
Pero~sn 8aurces:
Tnlhere present, typical sources of peroxygen species include
one or more of hydrogen peroxide, peracetic acid and/or
other organic or inorganic peroxygen sources. Hydrogen
peroxide is a preferred source of peroxygen species.
Typical levels of hydrogen peroxide range from 1-10$wt on
product with levels of 3-8~ being particularly preferred.
Surfactants :
Preferred compositions according to the invention
additionally comprise nonionic surfactant and/or
hydrotrope.
Suitable nonionic detergent active compounds (surfactants)
can be broadly described as compounds produced by the
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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 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. Suitable nonionic surfactants include
alkoxylated alcohols and alkyl phenols, preferably
ethoxylated alcohols
The preferred ethoxylated alcohols are of the general
formula:
Rl- (OCH2CH2 ),~ OH
wherein R1 is straight or branched C8-C18 alkyl or
hydroxyalkyl (preferably alkyl) and m is, on average, 1-14.
Ethoxylated alcohols suitable for use in the present
invention include the LIAL series available in the
marketplace from DAC, such as LIAL 111.10E0 [TM). Typical
levels of nonionic surfactant in products according to the
present invention range from 0-5$.
Suitable hydrotropes include lower aliphatic alcohols,
especially ethanol, urea and/or alkylaryl-sulphonates such
as salts of, particularly alkali metal salts of toluene-,
cumene- or xylene-sulphonate.
The preferred hydrotropes are alkylaryl-sulphonates, most
preferably sodium cumene-sulphonate. A suitable material is
ELTESOL SC 40 (TM Albright and Wilson). Typical levels of
hydrotrope range from 0.05-2~wt on product.
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In particularly preferred embodiments of the invention the
alkoxylated aliphatic amine is present together with an
anionic surfactant at levels of these materials are such
that they interact so as to thicken the composition
Preferably, formulations comprising the alkylaryl
sulphonates are formulated at a pH below 2, more preferably
below 1.5, even more preferably below 1. Without wishing to
limit the invention by reference to any theory of
operation, it is believed that at such a low pH, the
ethoxylated amine behaves as a cationic surfactant and
interacts with the alkylaryl sulphonate to form a water-
insoluble gel which deposits as a monolayer on surfaces.
It is believed that this monolayer lowers the surface
energy of the surface and retards or prevents the
deposition of further limescale.
The preferred mole ratio of the ethoxylated amine and the
anionic surfactant is 3-3.5, more preferably 3.25-3.5.
The preferred viscosity of the cleaning compositions
according to the present invention is between 50 mPas and
1000 mPas when measured at 11.7 sec-1 shear and at 25
Celcius using Haake RV2 rotoviscometer~ and an MV1 bob.
Particularly preferred compositions according to the
present invention comprise:
a) 1-l0~wt, preferably 3-5~wt sulphamic acid,
b) 1-l0~wt, preferably 2-5$wt ethoxylated amine,
c) 0-.5~wt, preferably 0.05-1$wt, nonionic surfactant,
d) 0.05-2$wt, preferably 0.4-l.l~wt, anionic surfactant
hydrotrope
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e) 1-l0~wt, preferably 4-6~wt, hydrogen peroxide
Miaors:
While the combination of the surfactants in the
compositions of the invention provide a thickening effect
it is possible to add other thickeners. Gums, particularly
xanthan gums are suitable thickeners. Preferred xanthan
gums are the Kelzan (RTM) series (available from Kelco
Corp). If present, typical levels of xanthan gum range
from 0.05-lwt~. The resulting viscosity of the
composition, as measured on a Haake RV2 rotoviscometer
(RTM) is preferably in the range 10-200 mPas at 20
reciprocal seconds shear and 25°C, using an MV1 bob. More
preferably the viscosity is 10-100 mPas under the
conditions mentioned above.
Metal ion sequestrants such as ethylenediamine tetra-
acetate, amino-poly-phosphonates (such as those in the
DEQUEST~ range ex. Monsanto) and phosphates and a wide
variety of other poly-functional organic acids and salts,
can also optionally be employed. Preferred metal ion
complexing agents are selected from dipicolinic acid,
ethylenediamine tetra-acetic acid (EDTA) and its salts,
hydroxyethylidene-diphosphonic acid (bequest 2010),
ethylenediamine-tetra(methylene-phosphoric acid) (bequest
2040), diethylenetriamine-penta(methylene-phosphoric acid)
(bequest 2060).
Optional, minor components also include those typically
found in cleaning compositions and are selected from
opacifiers, colours perfumes and fluorescers.
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Preferred levels of perfume range from 0.05-2$wt. Acid
stable perfumes are available from a variety of sources.
A particularly preferred composition according to the
present invention comprises:
ETHOMEEN BTB/12 ex AKZO 2-5$ Ethoxylated
amine
SULPHAMIC ACID 4$
HYDROGEN 5$
PEROXIDE
LIAL 111.10E0 ex DAC 0.1$ Nonionic
surfactant
ELTESOL SC40 ex Albright 0.4-1.1$* Sodium Cumene-
Sulphonate
BRILLIANT BLUE 9 ex WJE 0.0021$ CI 307047/colour
PERFUME ex IFF 0.12$ Othello 39
DEQUEST 2066 ex Monsanto 0-0.3$
WATER to 100$
*variable to adjust viscosity
Typical products having the above formulation made with
3.0$wt of the amine and around 0.56$wt of the SCS are
clear, have a specific gravity of 1.040 g/ml, an initial
viscosity at 106 sec-1 (at 25°C) of 120mPas, an initial
viscosity at 11.7 sec-1 (at 25°C) of 300mPas and pH 0.9 (at
25°C).
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In order that the present invention may be further
understood it will be illustrated hereafter with reference
to the following non-limiting examples.
Examples:
E~cam~le 1: Aatibacterial Syaer~y
Suspension tests were carried out with compositions of the
invention and comparative compositions at typical in-uae
dilutions (2~) of a composition according to the invention.
The following bacterial strains were used in the suspension
tests.
Pseudomonas aeruginosa ATCC 15442
Staphylococcus aureus ATCC 6538
Enterococcus faecium DVG 8582
Proteus mirablis ATCC 14153
Antibacterial activity was determined according to EST
(DD177:1988) and performed under soil conditions of 0.03~wt
bovine serum albumen (BSA) at 19.5 Celcius. Total viable
count was determined after a five minute and a 30 minute
contact time using solutions as listed below and water of
standard hardness for controls. Log reduction relative to
water were determined. Viable organisms were determines by
culturing on Nutrient or Tryptone-soya agar for 48 hours at
37°C. Log decimal reductions were determined from the
viable counts. Table 1 below gives the results for 5 and 30
minutes contact time.
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Concentrations in the assay, which were representative of
those encountered in a toilet bowl after use of the product
according to the invention, were as follows:
Sulphamic acid: 0.08$wt
Hydrogen peroxide: 0.10~wt
Amine ethoxylate: 0.06~wt Ethomeen S/12 [TM]
TABLE 1 (lop kill).
Suspension test results showing mean log kill, cfu/ml.
CK = Complete Kill
NSK = No Significant Kill
Organism S.aureus E.faecium P. P.
mirabilis aerugi-
nosa
Soil 0.03 BSA 0.03 BSA 0.03 BSA 0.03 BSA
: ~.~ 5
Contact Ta.z ~ 3 Q ~ ~ ~' 3
: 0 0
'
... : .. ~ - . . ..
~ in ~'n' ~ . . .
..: .
.
.:
:
r
.. . ...... 0.00 ... 1.95 . . 0.00
Sulphamic :. 2.00 0.05 0.96 2.45
..
.
0.99
acid NSK NSK NSK NSK NSK
Sulphamic 1.62 2.15 0.00 0.14 1.74 0.93 2.36 1.64
acid + NSK NSK NSK NSK NSK
peroxide
sulphamic 3.54 3.99 1.01 5.01 4.3 4.85 6.95 4.36
acid + NSK QC
peroxide +
amine
ethoxylate
sulphamic 3.29 3.91 1.56 5.01 2.69 4.85 6.95 4.36
acid + amine NSK CK
ethoxylate
ft
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Initial Couats:
Staphylococcus aureus ATCC 6538 6.99
Enterococcus faecium DVG 8582 6.99
Pseudomonas aeruginosa ATCC 15442 4.36
Proteus mirabilis ATCC 14253 4.95
A neutraliser of Tween (TM) Peptone, volume of 49m1 was
used. Therefore where counts are zero this is equivalent
to <5Ocfu/ml or log 50 = 1.70 survivors. From this table it
can be seen that the combination of sulphamic acid and
amine ethoxylate has improved bacteriocidal properties over
sulph.amic acid per se, against this broad range of
bacteria. In the table figures above 3, indicating
disinfectant behaviour are printed in bold.
In particular, it can be seen that sulphamic acid alone
(first example) has poor antimicrobial properties which are
not significantly improved by the presence of hydrogen
peroxide (compare first two examples), but that the
compositions which comprise both sulphamic acid and the
amine ethoxylate (compare bottom two examples) have
antimicrobial properties which are almost as good as those
of systems which further comprise hydrogen peroxide (bottom
example).
