Note: Descriptions are shown in the official language in which they were submitted.
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LIQUID CLEANING COMPOSITION
Field of the Invention
The present invention relates to liquid cleaning composition containing only
surfactants that are considered as being biodegradable under anaerobic
conditions.
Despite that limited surfactant choice, the composition still has excellent
grease cutting
proterties, excellent foam collapse and improved residue profile.
Background of the Invention
This invention relates to an all-purpose liquid cleaning composition which
does
not contain surfactants that are not biodegradable under anaerobic conditions
but
which still exhibits excellent foam collapse properties, excellent grease
cutting
properties and improved residue profile and is designed in particular for
cleaning hard
surfaces.
In recent years all-purpose liquid detergents have become widely accepted for
cleaning hard surfaces, e.g., painted woodwork and panels, tiled walls, wash
bowls,
bathtubs, linoleum or tile floors, washable wall paper, etc. Such all-purpose
liquids
comprise clear and opaque aqueous mixtures of water-soluble synthetic organic
detergents and water-soluble detergent builder salts. In order to achieve
comparable
cleaning efficiency with granular or powdered all-purpose cleaning
compositions, use of
water-soluble inorganic phosphate builder salts was favored in the prior art
all-purpose
liquids. For example, such early phosphate-containing compositions are
described in
U.S. Patent Nos. 2,560,839; 3,234,138; 3,350,319; and British Patent No.
1,223,739.
In view of the environmentalist's efforts to reduce phosphate levels in ground
water, improved all-purpose liquids containing reduced concentrations of
inorganic
phosphate builder salts or non-phosphate builder salts have appeared. A
particularly
useful self-opacified liquid of the latter type is described in U.S. Patent
No. 4,244,840.
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However, these prior art all-purpose liquid detergents containing detergent
builder salts or other equivalent tend to leave films, spots or streaks on
cleaned
unrinsed surfaces, particularly shiny surfaces. Thus, such liquids require
thorough
rinsing of the cleaned surfaces which is a time-consuming chore for the user.
In order to overcome the foregoing disadvantage of the prior art all-purpose
liquid, U.S. Patent No. 4,017,409 teaches that a mixture of paraffin sulfonate
and a
reduced concentration of inorganic phosphate builder salt should be employed.
However, such compositions are not completely acceptable from an environmental
point of view based upon the phosphate content. On the other hand, another
alternative to achieving phosphate-free all-purpose liquids has been to use a
major
proportion of a mixture of anionic and nonionic detergents with minor amounts
of glycol
ether solvent and organic amine as shown in U.S. Patent No. 3,935,130. Again,
this
approach has not been completely satisfactory and the high levels of organic
detergents necessary to achieve cleaning cause foaming which, in turn, leads
to the
need for thorough rinsing which has been found to be undesirable to today's
consumers.
Another approach to formulating hard surfaced or all-purpose liquid detergent
composition where product homogeneity and clarity are important considerations
involves the formation of oil-in-water (o/w) microemulsions which contain one
or more
surface-active detergent compounds, a water-immiscible solvent (typically a
hydrocarbon solvent), water and a "cosurfactant" compound which provides
product
stability. By definition, an o/w microemulsion is a spontaneously forming
colloidal
dispersion of "oil" phase particles having a particle size in the range of 25
to 800 ~ in a
continuous aqueous phase.
In view of the extremely fine particle size of the dispersed oil phase
particles,
microemulsions are transparent to light and are clear and usually highly
stable against
phase separation.
Patent disclosures relating to use of grease-removal solvents in o/w
microemulsions include, for example, European Patent Applications EP 0137615
and
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EP 0137616 - Herbots et al; European Patent Application EP 0160762 - Johnston
et al;
and U.S. Patent No. 4,561,991 - Herbots et al. Each of these patent
disclosures also
teaches using at least 5% by weight of grease-removal solvent.
It also is known from British Patent Application GB 2144763A to Herbots et al,
published March 13, 1985, that magnesium salts enhance grease-removal
performance of organic grease-removal solvents, such as the terpenes, in o/w
microemulsion liquid detergent compositions. The compositions of this
invention
described by Herbots et al. require at least 5% of the mixture of grease-
removal solvent
and magnesium salt and preferably at least 5% of solvent (which may be a
mixture of
water-immiscible non-polar solvent with a sparingly soluble slightly polar
solvent) and at
least 0.1 % magnesium salt.
However, since the amount of water immiscible and sparingly soluble
components which can be present in an o/w microemulsion, with low total active
ingredients without impairing the stability of the microemulsion is rather
limited (for
example, up to 18% by weight of the aqueous phase), the presence of such high
quantities of grease-removal solvent tend to reduce the total amount of greasy
or oily
soils which can be taken up by and into the microemulsion without causing
phase
separation.
The following representative prior art patents also relate to liquid detergent
cleaning compositions in the form of o/w microemulsions: U.S. Patents No.
4,472,291 -
Rosario; U.S. Patent No. 4,540,448 - Gauteer et al; U.S. Patent No. 3,723,330 -
Sheflin; etc.
Liquid detergent compositions which include terpenes, such as d-limonene, or
other grease-removal solvent, although not disclosed to be in the form of o/w
microemulsions, are the subject matter of the following representative patent
documents: European Patent Application 0080749; British Patent Specification
1,603,047; and U.S. Patent Nos. 4,414,128 and 4,540,505. For example, U.S.
Patent
No. 4,414,128 broadly discloses an aqueous liquid detergent composition
characterized by, by weight:
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(a) from 1 % to 20% of a synthetic anionic, nonionic, amphoteric or
zwitterionic surfactant or mixture thereof;
(b) from 0.5% to 10% of a mono- or sesquiterpene or mixture thereof, at a
weight ratio of (a):(b) being in the range of 5:1 to 1:3; and
(c ) from 0.5% 10% of a polar solvent having a solubility in water at 15~C in
the range of from 0.2% to 10%. Other ingredients present in the formulations
disclosed
in this patent include from 0.05% to 2% by weight of an alkali metal, ammonium
or
alkanolammonium soap of a C13-C24 fatty acid; a calcium sequestrant from 0.5%
to
13% by weight; non-aqueous solvent, e.g., alcohols and glycol ethers, up to
10% by
weight; and hydrotropes, e.g., urea, ethanolamines, salts of lower alkylaryl
sulfonates,
up to 10% by weight. All of the formulations shown in the Examples of this
patent
include relatively large amounts of detergent builder salts which are
detrimental to
surface shine.
Summary of the Invention
The present invention provides an improved, liquid cleaning composition which
does not contain surfactants that are not biodegradable under anaerobic
conditions but
still having excellent foam collapse properties and improved residue profile,
and
excellent grease cutting property and which is suitable for cleaning hard
surfaces such
as plastic, vitreous and metal surfaces having a shiny finish, oil stained
floors,
automotive engines and other engines. More particularly, the improved cleaning
compositions, with excellent foam collapse properties and excellent grease
cutting
property exhibit good grease soil removal properties due to the improved
interfacial
tensions, when used in undiluted (neat) or dilute form and leave the cleaned
surfaces
shiny without the need of or requiring only minimal additional rinsing or
wiping. The
latter characteristic is evidenced by little or no visible residues on the
unrinsed cleaned
surfaces and, accordingly, overcomes one of the disadvantages of prior art
products.
Surprisingly, these desirable results are accomplished even in the absence of
polyphosphate or other inorganic or organic detergent builder salts and also
in the
complete absence or substantially complete absence of grease-removal solvent.
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In one aspect, the invention generally provides a stable, hard surface
cleaning
composition especially effective in the removal of oily and greasy oil. The
cleaning
composition includes, on a weight basis:
(a) 0.5% to 4% of an ethoxylated nonionic surfactant formed from a C9
5 C"alkanol and about 2 to about 3 moles of ethylene oxyde;
(b) 2% to 7% of an ethoxylated nonionic surfactant formed from a C8 C,8
alkanol and about 6 to 9, preferably about 7 to about 8.5 mole of ethylene
oxyde;
(c) 0 % to 6%, more preferably 0.05% to 5% of a C1-C4 alkanol such as
ethanol and/or propanol and/or 0% to 6% of a propylene glycol ether;
(d) 0.1 % to 5% of a solubilizer selected from the group consisting of sodium
xylene sulfonate and/or sodium cumene sulfonate;
(e) 0.25% to 6% of magnesium inorganic salt;
(f) 0.05% to 2% of a fatty acid;
(g) 0.1 % to 5.0% of a perfume or essential oil;
(h) 0.05% to 2.5% of an alkali metal salt of a polycarboxylic acid having a
molecular weight of about 5,000 to about 15,000; and
(i) the balance being water, wherein the composition does not contain an
amine having a pK value of more than 9, a furan-malefic anhydride copolymer
sequestering agent or a water soluble detergency builder and the composition
does not
contain a water-soluble polyethylene glycols having a molecular weight of 150
to 1000,
polypropylene glycol of the formula HO(CHgCHCH20)nH wherein n is a number from
2
to 18, mixtures of polyethylene glycol and polypropylene glycol (Synalox) and
mono
and di C1-C6 alkyl ethers and esters of ethylene glycol having the structural
formulas
R(X)nOH, R1(X)nOH, R(X)nOR and R1(X)nORlwherein R is C1-Cg alkyl group, R1 is
C2-C4 acyl group, X is (OCH2CH2) or (OCH2(CHg)CH) and n is a number from 1 to
4,
diethylene glycol, polyamino acids, monosuccinic acids selected from the group
consisting of succinic acid, glutaric acid; and phosphoric acid and any salts
thereof,
ethylene diamine tetraacetic acid or any salt thereof, , enzymes, zeolite,
alkali metal
silicates, triethylene glycol,
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Also excluded from the instant all purpose cleaning compositions are grease
release agents characterized by the formula:
~2
R + R X_
I
R3
wherein R1 is a methyl group and R2, R3 and R4 are independently selected from
the
group consisting of methyl, ethyl, and CH2CH2Y, wherein Y is selected from the
group
consisting of CI, Br, C02H, (CH20)nOH wherein n=1 to 10, OH, CH2CHgOH and x is
selected from the group consisting of CI, Br, methosulfate
I
cH~---o~~ o
0
and _HC03
Also excluded from the instant all purpose cleaning compositions are grease
release agents which are an ethoxylated malefic anhydride-alpha-olefin
copolymer
having a comblike structure with both hydrophobic and hydrophilic chains and
is
depicted by the formula:
C02H
H~H~- (CHyCH
I =O ( H2)x
CH3
(CH2 C 2 O~H y
wherein n is about 5 to about 14, preferably about 7 to 9, x is about 7 to 19,
preferably
8 to 19 and y is of such a value as to provide a molecular weight about 10,000
to about
30,000.
Detailed Descri~~tion of the Invention
The present invention relates to a stable optically hard surface cleaning
composition comprising approximately by weight: 0.5% to 4% of a first nonionic
surfactant; 2% to 7% of a second nonionic surfactant; 0.1 % to 5% of a
solubilizer;
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0.05% to 2.5% of an alkali metal salt of a polycarboxylic acid; 0.05% to 2% of
a fatty
acid; 0.25% to 6% of magnesium sulfate heptahydrate; 0.1 % to 5% of an
essential oil
or a perfume, , and the balance being water.
As used herein and in the appended claims the term "perfume" is used in its
ordinary sense to refer to and include any non-water soluble fragrant
substance or
mixture of substances including natural (i.e., obtained by extraction of
flower, herb,
blossom or plant), artificial (i.e., mixture of natural oils or oil
constituents) and
synthetically produced substance) odoriferous substances. Typically, perfumes
are
complex mixtures of blends of various organic compounds such as alcohols,
aldehydes, ethers, aromatic compounds and varying amounts of essential oils
(e.g.,
terpenes) such as from 0% to 80%, usually from 10% to 70% by weight, the
essential
oils themselves being volatile odoriferous compounds and also serving to
dissolve the
other components of the perfume.
In the present invention the precise composition of the perfume is of no
particular consequence to cleaning performance so long as it meets the
criteria of
water immiscibility and having a pleasing odor. Naturally, of course,
especially for
cleaning compositions intended for use in the home, the perfume, as well as
all other
ingredients, should be cosmetically acceptable, i.e., non-toxic,
hypoallergenic, etc..
The instant compositions show a marked improvement in ecotoxocity as compared
to
existing commercial products.
Suitable essential oils are selected from the group consisting of:
Anethole 20/21 natural, Aniseed oil china star, Aniseed oil globe brand,
Balsam (Peru),
Basil oil (India), Black pepper oil, Black pepper oleoresin 40/20, Bois de
Rose (Brazil)
FOB, Borneol Flakes (China), Camphor oil, White, Camphor powder synthetic
technical, Cananga oil (Java), Cardamom oil, Cassia oil (China), Cedarwood oil
(China)
BP, Cinnamon bark oil, Cinnamon leaf oil, Citronella oil, Clove bud oil, Clove
leaf,
Coriander (Russia), Coumarin 69°C (China), Cyclamen Aldehyde, biphenyl
oxide, Ethyl
vanilin, Eucalyptol, Eucalyptus oil, Eucalyptus citriodora, Fennel oil,
Geranium oil,
Ginger oil, Ginger oleoresin (India), White grapefruit oil, Guaiacwood oil,
Gurjun
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balsam, Heliotropin, Isobornyl acetate, Isolongifolene, Juniper berry oil, L-
methyl
acetate, Lavender oil, Lemon oil, Lemongrass oil, Lime oil distilled, Litsea
Cubeba oil,
Longifolene, Menthol crystals, Methyl cedryl ketone, Methyl chavicol, Methyl
salicylate,
Musk ambrette, Musk ketone, Musk xylol, Nutmeg oil, Orange oil, Patchouli oil,
Peppermint oil, Phenyl ethyl alcohol, Pimento berry oil, Pimento leaf oil,
Rosalin,
Sandalwood oil, Sandenol, Sage oil, Clary sage, Sassafras oil, Spearmint oil,
Spike
lavender, Tagetes, Tea tree oil, Vanilin, Vetyver oil (Java), Wintergreen
The cleaning composition also contains an inorganic or organic salt of oxide
of a
multivalent metal cation, particularly Mg++. The metal salt or oxide provides
several
benefits including improved cleaning performance in dilute usage, particularly
in soft
water areas, and minimized amounts of perfume required to obtain the
microemulsion
state. Magnesium sulfate, either anhydrous or hydrated (e.g., heptahydrate),
is
especially preferred as the magnesium salt. Good results also have been
obtained
with magnesium oxide, magnesium chloride, magnesium acetate, magnesium
propionate and magnesium hydroxide. These magnesium inorganic salts can be
used
with formulations at neutral or acidic pH since magnesium hydroxide will not
precipitate
at these pH levels. Although magnesium is the preferred multivalent metal from
which
the salts (inclusive of the oxide and hydroxide) are formed, other polyvalent
metal ions
also can be used provided that their salts are nontoxic and are soluble in the
aqueous
phase of the system at the desired pH level.
The cleaning compositions include from about 0.05% to about 2.0% by weight of
the composition of a Cg-C22 fatty acid or fatty acid soap as a foam
suppressant.
The addition of fatty acid or fatty acid soap provides an improvement in the
rinseability of the composition whether applied in neat or diluted form.
Generally,
however, it is necessary to increase the level of cosurfactant to maintain
product
stability when the fatty acid or soap is present. If more than 2.5 wt. % of a
fatty acid is
used in the instant compositions, the composition will become unstable at low
temperatures as well as having an objectionable smell.
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As example of the fatty acids which can be used as such or in the form of
soap,
mention can be made of distilled coconut oil fatty acids, "mixed vegetable"
type fatty
acids (e.g. high percent of saturated, mono-and/or polyunsaturated C1 g
chains); oleic
acid, stearic acid, palmitic acid, eiocosanoic acid, and the like, generally
those fatty
S acids having from 8 to 22 carbon atoms being acceptable.
The C1-C4 alkanol is preferably ethanol and/or isopropanol.
The final essential ingredient in the inventive cleaning corripositions or all
purpose hard surface cleaning compositions is water. The proportion of water
in the all
purpose hard surface cleaning composition compositions generally is in the
range of
20% to 97%, preferably 70% to 97% by weight.
The liquid cleaning composition of this invention may, if desired, also
contain
other components either to provide additional effect or to make the product
more
attractive to the consumer. The following are mentioned by way of example:
Colors or
dyes in amounts up to 0.5% by weight; bactericides in amounts up to 1 % by
weight;
preservatives or antioxidizing agents, such as, 5-bromo-5-nitro-dioxan-1,3; 5-
chloro-2-
methyl-4-isothaliazolin-3-one, 2,6-di-tert.butyl-p-cresol, etc., in amounts up
to 2% by
weight; and pH adjusting agents, such as sulfuric acid or sodium hydroxide, as
needed.
Furthermore, if opaque compositions are desired, up to 4% by weight of an
opacifier
may be added.
In final form, the cleaning compositions exhibit stability at reduced and
increased
temperatures. More specifically, such compositions remain clear and stable in
the
range of 4°C to 50°C, especially 2°C to 43°C. Such
compositions exhibit a pH in the
acid or neutral range depending on intended end use. The liquids are readily
pourable
and exhibit a viscosity in the range of 6 to 60 milliPascal second (mPas.) as
measured
at 25°C with a Brookfield RVT Viscometer using a #1 spindle rotating at
20 RPM.
Preferably, the viscosity is maintained in the range of 10 to 40 mPas.
The compositions are directly ready for use or can be diluted as desired and
in
either case no or only minimal rinsing is required and substantially no
residue or
streaks are left behind. Furthermore, because the compositions are free of
detergent
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builders such as alkali metal polyphosphates they are environmentally
acceptable and
provide a better "shine" on cleaned hard surfaces. Environmental profile is
also greatly
improved by the fact that the composition does not contain surfactants that
are non
biodegradable under anaerobic conditions.
5 When intended for use in the neat form, the liquid compositions can be
packaged under pressure in an aerosol container or in a pump-type sprayer for
the so-
called spray-and-wipe type of application.
Because the compositions as prepared are aqueous liquid formulations and
since no particular mixing is required to form the microemulsion, the
compositions are
10 easily prepared simply by combining all the ingredients in a suitable
vessel or
container. The order of mixing the ingredients is not particularly important
and
generally the various ingredients can be added sequentially or all at once or
in the form
of aqueous solutions of each or all of the surfactants and amphiphiles can be
separately prepared and combined with each other and with the perfume. The
magnesium salt, or other multivalent metal compound, when present, can be
added as
an aqueous solution thereof or can be added directly. It is not necessary to
use
elevated temperatures in the formation step and room temperature is
sufficient.
The instant cleaning compositions explicitly exclude alkali metal silicates
and
alkali metal builders such as alkali metal polyphosphates, alkali metal
carbonates, alkali
metal phosphonates and alkali metal citrates because these materials, if used
in the
instant composition, would cause the composition to have a high pH as well as
leaving
residue on the surface being cleaned.
The following examples illustrate liquid cleaning compositions of the
described
invention. Unless otherwise specified, all percentages are by weight. The
exemplified
compositions are illustrative only and do not limit the scope of the
invention. Unless
otherwise specified, the proportions in the examples and elsewhere in the
specification
are by weight.
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Example 1
The following compositions in wt. % were prepared by simple mixing at
25°C:
A B
C9-C11 alcohol EO 2-3:11 2
Ethanol 0 1
C8-18 alcohol E07.5-8:14 4
Pol carbox lic acid 0.25 0.5
sodium salt
Coconut fatt acid 0.2 0.5
Sodium cumene sulfonate4 4
40%
M S04 7 H20 0.5 1
Perfume 0.65 0.65
afar Balance Balance
Grease cutting
Neat 84% 93%
Dilute 88% 99%
Residue ~ Better than Better than
reference reference
~