Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
PATENT
Case D 7813-I CA
A ~IQUID NON-PHOSP~IATE DETERGENT OF HIGH ALKALINITY
BACKGROUND OF THE INVENTION
Field of the Invention:
Laundry detergents for institutional laundries differ
considerably in their composition from those typically used
in the home. On the one hand, softened water, i.e. Ca- and
Mg-free water, is generally used in institutional laun-
dries. On the other hand, institutional laundry deter-
gents often contain highly alkaline builder salts and
alkalis, such as sodium metasilicate and sodium hydroxide,
which - although they can be safely handled by the expert -
are unadvisable in the home for safety reasons. These
highly alkaline constituents can in turn interact with the
surfactants typically present, particularly nonionics of
the alkyl polyglycol ether type, and can decompose them to
a greater or lesser extent in the event of prolonged
storage together. These problems exist in particular in
the case of liquid concentrates and products which are
intended for the preparation of concentrated stock solu-
tions and in whose case the decomposing effect is particu-
larly intensive through lack of spatial separation between
the surfactant and alkali component. Highly alkaline
liquid products and stock solutions have the advantage over
powder-form preparations of the same composition in that
they are dust free and, in particular, can be automatically
dispensed and hence pose no operating problems.
Another aspect is the almost exclusive use of surfac-
tants which can be obtained from natural, i.e. renewable,
raw materials and which are distinguished by complete and
rapid biodegradability in the wastewater.
In addition, detergents of the type in question should
not produce troublesome quantities of foam either in the
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main wash cycle or in the final rinse cycle. Since stan-
dard foam inhibitors, such as polysiloxanes and paraffin
hydrocarbons, undergo losses of effect when dispersed in
liquid detergents or, in the case of polysiloxanes, are
decomposed by alkali, the surfactant component must i$self
be low-~oaming.
DESCRIPTION OF THE_INVENTION
Other than in the operating examples, or where
otherwise indicated, all numbers expressing quantities of
ingredients or reaction conditions used herein are to be
understood as modified in all instances by the term
"about".
The present invention, by which these problems are
solved, relates to a liquid, aqueous, non-phosphate deter-
gent concentrate comprising 5 to 20% by weight of a non-
ionic surfactant component (A), 15 to 40% by weight of a
builder component (B), up to 3% by weight of other non-
surfactant and non-builder detergent constituents and the
balance, water wherein said components have the following
composition, based on the weight of the detergent:
~1) 4 to 20% by weight of an alkyl glucoside corresponding
to formula ~
R-0-GX (I)
where R = a C814 alkyl radical, G = a glucose residue
and x = a number of 1.2 to 5,
A2) o to 2~ by weight of at least one nonionic surfactant
selected from the group consisting of alkyl polyglycol
ethers containing C1218 alkyl groups and 5 to 9
ethylene oxide groups,
B1) 4 to 20% by weight sodium hydroxide,
B2) 0.5 to 12% by weight sodium silicate having the
composition ratio Na20 : sio2 = 1:1 to 1:3.4,
B3) 2 to 12% by weight sodium nitrilotriacetate, and
B4) 0 to 3% by weight of the sodium salt of at least one
phosphoric acid, with the proviso that the content of
constituents B3) + B4) is from 3 to 12% by weight.
3 ~
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The detergent preferably contains the individual
components in the following quantities:
A1) 5 to 12 ~ by weight
A2) 0.5 to 1.5 % by weight
B1) 6 to 15 % by weight
B2) 0.5 to 3 % by weight
B3) 3 to 10 % by weight
B4) 0.2 to 2 ~ by weight
Component (Al) comprises alkyl glucosides or alkyl
oligoglucosides of the type described, for example, in US
Patents 3,5~7,828, 3,772,269 and 3,839,318. They are
obtainable by reaction of glucose or depolymeriæed starch
and alcohols containing C814 alkyl groups in the presence or
absence of lower alcohols or glycols, such as butanol or
propylene glycol, and acidic acetalization catalysts.
Alcohols or mixtures of alcohols obtained from natural
fats, such as coconut oil or palm kernel oil, are
preferably used as the fatty alcohols. Examples include
octyl, decyl, lauryl and myristyl alcohol and also mixtures
thereof. Alternatively, it is also possible to use alkyl
glucosides which are derived from oxoalcohols and which, in
addition to linear alcohols, also contain alcohols which
are methyl-branched in the 2-position in admixture or an
even or odd number of C atoms in the alkyl chain.
Examples are octyl, nonyl, decyl, undecyl, dodecyl and
tridecyl alcohol and also mixtures thereof. R is prefer-
ably a C812 alkyl group and more especially a C810 alkyl
groupO In the reaction of the glucose or glucose~contain-
ing starch degradation products with the alcohols, the
glucose is partly oligomerized in the presence of acidic
acetalization catalysts, resulting in the formation of
mixtures of alkyl monoglucosides and alkylol oligogluco-
sides. The parameter x in formula I thus represents an
average degree of oligomerization and is preferably from
1.3 to 3. Mixtures such as these are meant where alkyl
glucosides are mentioned generally in the context of the
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invention.
From their production, the alkyl glucosides still
contain small quantities of free fatty alcohol and glucose.
Alkyl glucosides containing less than 5% by weight and,
more especially, less than 2% by weight fatty alcohols
(based on alkyl glucoside) are preferably used.
In addition to the alkyl glucosides, the detergents
may optionally contain nonionic surfactants of the ethoxy-
lated fatty alcohol and oxoalcohol type containing 12 to 18
C atoms and 5 to 9 ethylene oxide groups (E0) as component
(A2). Suitable nonionic surfactants of this type are, for
example, ethoxylates derived from coconut oil, tallow or
palm kernel oil fatty alcohols having an HLB value of more
than 12, for example from 13 to 18, and corresponding
ethoxylates of oxoalcohols containing 12 to 16 C atoms and
6 to 8 E0 groups.
The builder component comprises sodium hydroxide
(constituent Bl), sodium silicate (constituent B2) and
sequestering polyanionic salts derived from nitrilotriace-
tic acid (NTA) and, optionally, phosphonic acids (constitu-
ents B3 and B4).
In the sodium silicate, the ratio of Na20 to sio2 may
be from 1:1 (metasilicate) to 1:3.4 (waterglass). In
detergents containing relatively small amounts of sodium
hydroxide, metasilicate is preferably used in the interests
of high alkalinity whereas, in detergents having relatively
high contents of sodium hydroxide, the sodium silicate may
consist predominantly or completely of waterg].ass.
The NTA is present in the form of the trisodium salt,
the quantitative calculation also being based on this form.
The NTA content is preferably from 5 to 10% by weight.
The phosphonate is primarily the sodium salt of 1-
hydroxyethane~ -diphosphonic acid (HED~). The quantita-
tive calculation is based on the tetrasodium salt. It is
also possible to use the sodium salts of aminotrimethylene
phosphonic aci~ (ATMP), ethylenediamine tetramethylene
rj
phosphonic acid ~EDTMP), diethylenetriamine pentamethylene
phosphonic acid (DTPMP) and higher homologs thereof, al-
though EDTMP is less preferred on account of its as yet
unclear property in the wastewater. Their quantitative
calculation is based on neutrally reacting sodium salts (Na3
salt in the case of ATMP, Nas salt in the case of ~DTMP, Na6
salt in the case of DTPMP). The sum of components B3 + B4
is from 3 to 12% by weight and preferably from 6 to 11% by
weight.
In addition to the constituents mentioned above, the
detergents may contain other non-surfactant and non-builder
constituents, including optical brighteners in a quantity
of up to 1% by weight and preferably from 0.05 to 0.3% by
weight. Examples of optical brighteners are derivatives of
bis-(triazinylamino)-stilbene disulfonic acid, for example
the sodium salt of 4,4'-bis-(2-anilino-4-morpholino-1,3,5-
triazin-6-ylamino)-stilbene-2,2'-disulfonic acid and of the
chlorinated diphenyl distyryl sulfonic acids.
Other optional constituents are enzymes, fragrances,
dyes, hydrotropes and water-miscible solvents. Suitable
hydrotropes are, for example, toluenesulfonate, xylenesul
fonate and cumenesulfonate, in each case in the form of the
sodium salts. Suitable solvents are, for example, ethanol,
propanol, isopropanol and also ether alcohols, such as di-
glycol, and C13 monoalkyl ethers of C24 diols. The hydro-
tropes may be present in quantities of up to 6% by weight
while the alcohols or ether alcohols may be present in
quantities of up to 10% by weight. The detergents may also
contain neutral salts, such as sodium sulfate and sodium
chloride, in small quantities as impurities of the raw
materials used. The balance to 100% by weight consists
essentially of water.
The detergents are storable, pourable liquids which
are suitable both for automatic dispensing and also for the
preparation of stock solutions. The concentrates remain
liquid and are stable to separation at temperatures of down
to -10 D C. Their in-use concentration is generally from 2
to 10 g/l and preferably from 3 to 7 g/l.
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EXAMPLES
Detergents were prepared from the following constitu~
ents. In the alkyl glucoside, R was a mixture of C810
groups and X - 1.8, prepared by the direct synthesis
method.
Table 1
1 0
Example
Constituent 1 2 3 4 5
(quantities in % by weight)
Alkyl glucoside 6 6 8 6 7
C121s alcohol ~ 7 EO 1 1 - 1 1
NaOH 10 12.5 15 6 13
Na2-SiO3 (1:3-3) 2 2 2 0.7 2.5
NTA (Na3 salt) 8 8 8 6 5
HEDP (Na salt) 2 _ 1 1 2.5
EDTMP (Na salt)
DTPMP (Na salt) - - 1 _ 1
Optical brightener 0.1 0.1 0.1 0.1 0.1
Na cumenesulfonate - - - 4
Isopropanol - - - 5
Water bal- bal bal- bal- bal-
ance ance ance ance ance
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A washing machine (of the Frista~R) type) was loaded
with lightly soiled laundry (bed and table linen which had
been used once) and test cloths soiled as follows:
Al dust-wool grease on cotton
A2 blood-milk-indian ink on cotton
A3 blood on cotton
A4 milk cocoa on cotton
A5 dust-sebum on crease-resistant cotton
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A6 dust-sebum on crease-resistant cotton/polyester blend
A7 dust-wool grease on blended fabric ~as A6).
The quantity of laundry amounted to 7.5 kg, the water
hardness was 0Gh, normal program (no prewash), detergent
concentration 4 g/1, 5 minutes at 40C and 15 minutes at
90C, three rinses, low foaming.
The percentage remission (against a white standard)
was photometrically evaluated. The values represent
averages of three parallel determinations (scattering 2%).
The results are shown in Table 2 below. A commercially
available detergent of similar composition (without gluco-
side) was used for comparison (C). Equally good washing
results were also obtained when alkyl glucosides in which
x = 1.4 and x = 2.2 were used instead of the alkyl gluco-
side in which x = 1.8.
Table 2
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% Remission
Soil 1 2 3 5 C
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Al 75.9 73.2 73.1 73.8 71.5
A2 40.2 37.8 37.6 39.2 35.2
A3 83.5 82.4 82.6 82.7 78.2
A4 75.7 72.5 77.9 78.1 74.4
A5 58.6 54.6 52.0 53.8 48.1
A6 72.0 69.1 69.7 71.0 64.5
A7 58.9 56.0 53.6 58.1 49.3
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