Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
2~0~
CM 597F
The Use of Magnesium Ions in Hard Surface Cleaners
~or Improved Shine, and Cleaners Obtained Accordingly
Technical Field
The present invention relates to the cleaning of hard
surfaces, especially glossy surfaces.
8ack~round
Compositions for the cleaning of hard surfaces are
extensively discussed in the art. It is desirable that
such compositions should have, in particular, the ability
to provide a good shine to the cleaned surfaces. However,
surface shine is often compromised by residues of the
compositions which are left on said surfaces and which
appear as streaks as water evaporation is completed.
This streaking phenomenon caused by a composition's
residuality tends to be more of a problem as said
c- -sition is formulated as a concentrate, i.e it
comprises more actives and less water.
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Also, for a given composition, the residuality of said
composition is even more noticeable as said composition is
used to clean surfaces made of glossy materials, such as
glossy ceramic tiles, windows and mirrors, or such
materials as polyurethane-coated PVC which is widely used
in Northern America.
Also, many products of today are formulated or can be
used as no-rinse products. This residuality problem tends
to be more acute for such products or in such conditions,
as the rinsing step performed for other products cannot
participate here to decreasing the residuality.
It is thus an object of the present invention to
provide improved shine to hard surfaces, in a manner which
is applicable to a variety of cleaning compositions, and a
variety of surfaces.
Various solutions have been proposed in the art to
meet this object, including the use of certain solvents, or
the formulation of specific ingredient combinations.
It has now been found that this object could be met by
formulating a composition which comprises an anionic
surfactant system and an effective amount of magnesium ions
as counterions for said anionic surfactants. In other
words, for any given cleaning composition comprising an
anionic surfactant system, which causes residues to appear
on cleaned surfaces, adding an appropriate amount of
magnesium ions will cause said residues to appear less, or
even not to appear anymore.
Cleaning c- ~ositions comprising magnesium ions have
been extensively described in the art, mainly in the
context of dish washing, for instance in W0-A-9 206 171,
W0-A-9 206 156, US-A-4 129 515, GB-A-2 078 246, EP-A-0 107
946, EP-A-0 062 371, FR-A-2 324 723 and FR-A-2 296 688, but
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the benefits derivable therefrom in terms of low
residuality have never been acknowledged.
Summary of the Invention
The present invention encompasses the use, in a
composition for the cleaning of hard surfaces, said
composition comprising an anionic surfactant system, of
magnesium ions as counterions for said anionic surfactant
system, whereby the residuali~y of said cleaning
composition on said surfaces is reduced.
The present invention further encompasses a
concentrated cleaning composition which comprises short
chain surfactants and magnesium ions.
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Detailed Description of the Invention
In it broadest embodiment, the present invention
encompasses the use of magnesium ions, as counterions for
anionic surfactants, to reduce the residuality of cleaning
compositions for hard surfaces.
As used herein, the word "residuality" refers to the
propensity of a composition to leave visible residues on a
given surface. A composition with a high residuality is a
composition which leaves substantially visible residues on
surfaces, and which is therefore improper for use in a no-
rinse mode. A composition's residuality in given usage
conditions can be evaluated by measuring the glossiness of
a surface cleaned with said composition, for instance using
a glossmeter as described hereinafter.
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The present invention is based on the finding that, in
compositions comprising an anionic surfactant system, using
magnesium ions as counterions for said anionic surfactant
system will reduce the residuality of said compositions.
This residuality reduction phenomenon, i.e. the reduction
of the visibility of residues, but not necessarily the
amount of residues, is clearly noticeable by eye, and it
can be quantified by measuring the glossiness of a given
surface cleaned with a given composition without magnesium
ions, compared to the same reading with the same
composition supplemented with magnesium ions.
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The results obtained are independent of whether the
magnesium ions are introduced in the composition with the
anionic surfactant system, or as a separate ingredient,
i.e, it is unimportant whether the anionic surfactan~
system is neutralized by the magnesium ions in situ or not.
If not, the magnesium ions can be introduced in the
c_ ~a~itions in any given form. Suitable forms of
magnesium for use herein include Magnesium sulphate,
nitrate, and halogens.
The residuality reduction is dependant on the amount
of magnesium ions added. Thus, more or less magnesium ions
can be added depending on the degree of residuality
desired. In a preferred embodiment, an amount of magnesium
ions is used which is sufficient to act as counterion for
the totality of anionic surfactant present. Adding more
magnesium ions beyond that provides no extra benefit and is
thus unattractive from an economical viewpoint.
Accordingly, it is preferred that the molar ratio of said
bound magnesium ions to said anionic surfactant be of 1:2.
Depending on specifics, mainly the type of anionic
surfactant used, the counterion for said anionic surfactant
raw material, when said counterion is not magnesium, and
the binding constants for these, it may be appropriate to
add more magnesium in order to arrive at said ratio of 1:2.
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The appropriate amount of magnesium for a given composition
and to obtain a desired result can also be achieved by
simple trial and error.
The compositions suitable for use in the present
invention comprise an anionic surfactant system. By
anionic surfactant system, it is meant herein that the
compositions comprise at least one anionic surfactant.
Suitable anionic surfactants for use herein include
those well known in the art, i.e. C6-24 alkyl sulfates,
alkyl ether sulfates, alkyl sulfonates, alkyl benzene
sulphonates, alkyl succinates, alkyl carboxylates, alkyl
ether carboxylates, alkyl sarcosinates, alkyl sulfo
succinates and the like. Particularly preferred for use
herein are alkyl sulfonates, alkyl sulfates, alkyl benzene
sulphonates and alkyl ether sulfates.
While anionic surfactants derived from longer alkyl
chains, i.e. Cll and up are traditionally used to formulate
hard surface cleaning co _sitions, it has been found
advantageous to use anionic surfactants derived from
shorter alkyl chains, i.e. C6 to C10 to formulate
concentrated aqueous cleaning compositions which comprise
less water than the traditional cleaning compositions.
Indeed, it has been found that short chain surfactants
allow to formulate stable and clear concentrated cleaning
c_ __itions, whereas the same compositions with only
longer chain homologues are unclear or unstable. Short
chain anionic surfactants are c_- ?rcially available for
instance from Rhone Poulenc under the trade name Rhodapon@,
or from Witco under the trade name Witconate@. As used
herein , "concentrated cleaning compositions" refers to
c~ _sitions which comprise from 10% to 80% by weight of
the total composition of water, preferably from 15% to 75%,
most preferably from 30% to 75%.
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Thus to summarize, the compositionS herein comprise as
an essential feature an anionic surfactant system, which
represents from 0.5~ to 50% by weight of the total
composition, preferably from 1% to 20%. Said anionic
surfactant system may consist of long chain anionic
surfactants only, or mixtures thereof; it may also comprise
mixtures of short chain and long chain anionic surfactants.
Preferred for use herein is a ~ixture of short chain and
long chain anionic surfactants.
In addition to said anionic surfactant system, the
compositions herein may comprise a wide variety of co-
surfactants of other types, e.g. nonionic and zwitterionic
surfactants, preferably nonionic surfactants.
As for anionic surfactants herein above, it has been
found that short chain nonionic surfactants of the alkyl
alkoxylate type (C6-lo (OCH2CH2)e (OCH2CH2CH2)p OH, wherein
e and p are independ~ntly from O to 20 and e+p>O) also
provide benefits in formulating concentrated cleaning
compositions. Alkyl alkoxylates are well known in the art,
and the short chain alkyl alkoxylates suitable for use
herein are also available on the market, for instance from
sidobre under the trade name Mergital@C4 (C8E04), from Kolb
under the trade names Imbentin@ AG/810/050 (C8-lOE05) and
AG/810/080 (C8-lOE08).
It has also been found that certain short chain
nonionic surfactants have particular benefits as follows.
C6-8 alkyl alkoxylates, as defined hereinabove, provide
superior neat grease cleaning, and they are particularly
mild to the skin. C6-10 alkyl alkoxylates as defined
hereinabove are low foaming surfactants. C8-10 alkyl
alkoxylates as defined hereinabove are particularly
effective for dilute grease cleaning and for soap scum
removal.
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Thus the compositions herein may further comprise from
0.5~ to 80% by weight of the total composition, preferably
from 1% to 50%, of co-surfactants which are preferably
nonionic surfactants, and which may be only long chain
nonionic surfactants or mixtures thereof, only short chain
surfactants or mixtures thereof, or mixtures of short and
long chain nonionic surfactants. Preferred for use herein
is a mixture of short chain and long chain nonionic
surfactants.
The compositions herein can be formulated in a variety
of pH range, depending on the end-use envisioned. However,
it is preferable not to formulate at a pH above 10, as
magnesium may then form magnesium hydroxide which does not
participate to residuality reduction. Also, it is
preferable not to formulate at a pH below the anionic
surfactant's pK, as said anionic surfactant then becomes
protonated, and cannot effectively bind magnesium anymore.
The compositions herein may further comprise a variety
of other ingredients, including, solvents, bleaches,
enzymes, dyes, perfumes and other aesthetics.
The present invention is further illustrated by the
~ollowing examples.
Examples-Experiments
The following compositions were evaluated in terms of
their residuality with a Sheen 155 Gloss meter. The
following data was generated with the following
compositions at 0.3-1.5% dilution levels in 5 US
grains/gallon water hardness on different types of tiles.
As implement a sponge was used. Results are expressed in
terms of D gloss (= gloss before - gloss after application
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of the product). So the smaller the difference, the less
residuality.
NaPS 3 3
MgC12- 6H2~
C13-15 (EO)30 2 2
C13-15 (EO)7
palm kernel fatty acid 0.4 0.4
water/minors balance balance
D gloss 6.9 0.4
(white ceramic tiles)
Compositions 1 and 2 were used dilute at 1.2% dilution
level. Tests were done on white non-glossy ceramic floor
surfaces. Composition 1 (without magnesium ions) gave very
visible spots and streaks. The D gloss value on white
ceramic tiles was 6.9. Composition 2 (with magnesium
ions) showed no visible residues on the white ceramic
tiles. This was translated in the D gloss value, which was
only 0.4.
3 ~ 5
NaPS - ~ 5
MgSO4. 7 H2O - - 2
C13-15 (EO)30 5 5 5
C12-13 (EO)3 - 3 3
C8-10 (EO)5 10 10 lO
C8 alkyl sulphate 7 7 7
2-hexyl decanol
palm kernel fatty acid 0.5 0.5 0.5
water/minors balance balance balance
D gloss 8.6 3.2 2.0
(black glossy ceramic tiles)
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Compositions 3-5 were used at 0.6% dilution. Tests were
done on different types of typical floor surfaces.
Following results were noticed:
Composition 3 (without magnesium ions) gave streaks on
most hard surfaces. For example, on light colored non-
glossy ceramic tiles, which are representative of a typical
European floor, composition 3 gave visible streaks. On a
black glossy tile the residue formation was even more
visible. The residue was measured via gloss readings on the
black glossy ceramic tiles. The D gloss value was 8.6.
Composition 4 (same as 3, but with a further nonionic
surfactant) showed no visible streaks on the light colored
non-glossy surfaces, due to the improved spreading wetting
properties of the relatively hydrophobic C12-13 (EO)3
nonionic surfactant. However, the gloss readings indicated
there was still a substantial amount of residue. This
residue, however, was spread evenly over the surface. ~n
the dark colored high glossy highly hydrophobic surfaces,
composition 4 still left a visible, more evenly (compared
with formula 3) spread residue. The D gloss value on this
black glossy ceramic tile was 3.2.
Composition 5 (magnesium ions added) gave further
improved end results on the glossy tiles. Via adding Mg
salts and anionic surfactant the residuality further
decreased, despite a higher total level of actives. The D
gloss value on the Black glossy ceramic tiles was 2Ø
6 7
NaPS 5 3
MgSO4. 7 H2O 2 1.5
C13-15 (EO) 30 5 6
C12-13 (EO)3 3
C8-10 (EO) 5 10 15
C8 alkyl sulphate 10
2-hexyl decanol
palm kernel fatty acid 0.5
water/minors balance balance
Compositions 6 and 7 are two typical examples where the
present invention gives significant benefits in terms of
improving composition residuality. Both formulations had
very low residuality measured at dilution levels of 0.3-
1.5%.
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