Note: Descriptions are shown in the official language in which they were submitted.
~0639 62301-1370
LIQUID LAUNDRY DETERGENT-BLEACH
COMPOSITION AE_D EIETEIOD OF USE
BACKGROUND OF THE INVENTION
(1) Field of Invention
This invention relates to liquid laundry detergent
compositions. More particularly, this invention relates to
, non-aqueous liquid laundry detergent compositions which are
easily pourable and which do not gel when added to water and
to the use of these compositions for cleaning soiled fabrics.
(2) Discussion of Prior Art
Liquid non-aqueous heavy duty laundry detergent
compositions are well known in the art. For instance,
compositions of that type may comprise a liquid nonionic
surfactant in which are dispersed particles of a builder, as
shown for instance in the U. S. Patents Nos. 4,316,812;
3,630,929; 4,264,466, and British Patents Nos. 1,205,711,
1,270,040 and 1,600,981.
Liquid detergents are often considered to be more
convenient to employ than dry powdered or particulate products
and, therefore, have found subs-tantial favor with consumers.
They are readily measurable, speedily dissolved in the wash
water, capable of being easily applied in concentrated solutions
or dispersions to soiled areas on garments to be laundered and
are non-dusting, and they usually occupy less storage space.
Additionally, the liquid detergents may have incorporated in
their formulations materials which could not stand drying
operations without deterioration, which materials are often
desirably employed in the manufacture of particulate detergent
products. Although they are possessed o-E many advantages over
unitary or particulate solid products, liquid detergents often
have certain inherent disadvantages too, which have to be over-
.~ - 1 - ~
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come to produce acceptable commercial detergent products. Thus,
some such products separate out on storage and others separate
out on cooling and are not readily redispersed. In some cases
the product viscosity changes and it becomes either too thick
to pour or so thin as to appear watery. Some clear products
become cloudy and others gel on standing.
The present inventors have been extensively involved
in studying the rheological behavior of nonionic liquid
surfactant systems with and without particulate matter suspended
therein. Of particular interest has been non-aqueous built
laundry liquid detergent compositions and the problems of
gelling associated with nonionic surfactants as well as settling
of the suspended builder and other laundry additives. These
considerations have an impact on, for example, product pour-
ability, dispersibility and stability.
The rheological behavior of the non-aqueous built
liquid laundry detergents can be analogized to the rheological
behavior of paints in which the suspended huilder particles
correspond to the inorganic pigment and the nonionic liquid
surfactant corresponds to the non-aqueous paint vehicle. For
simplicity, in the following discussion, the suspended
particles~ e.g. detergent builder, will sometimes be referred
to as the "pigment".
It is known that one of the major problems with
paints and built liquid laundry detergents is their physical
stability.
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This problem stems from the fact that the density of the solid
pigment particles is higher than the density of the liquid matrix.
Therefore, the particles tend to sediment according to Stoke's
law. Two basic solutions exist to solve the sedimentation pro-
blem: liquid matrix viscosity and reducing solid particle size.
For instance, it is known that such suspensions can
be stabilized against settling by adding inorganic or organic
thickening agents or dispersants, such as, for example, very high
surface area inorganic materials, e.g. finely divided silica,
clays, etc., organic thickeners, such as the cellulose ethers,
acrylic and acrylamide polymers, polyelectrolytes, etc. However,
such increases in suspension viscosity are naturally limited by
the requirement that the liquid suspension be readily pourable
and flowable, even at low temperature. Furthermore, these
additives do not contribute to the cleaning performance of the
formulation.
Grinding to reduce the particle size is more advan-
tageous and provides two major consequences:
1. The pigment specific surface area is increased, and,
therefore, particle wetting by the non-aqueous vehicle (liquid
nonionic) is proportionately improved.
2. The average distance between pigment particles is
reduced with a proportionate increase in particle-to-particle
interaction. Each of these effects contributes to increase
the rest-gel strength and the suspension yield stress while
at the same time, g significantly reduces plastic viscosity.
The nonaqueous liquid suspensions of the detergent
builder particles, such as the polyphosphate builders, especially
sodium tripolyphosphate (TPP) in nonionic surfactant are found
to behave, rheologically, substantially according to
62301-1370
~L~9~
the Casson equation:
a O ~ n ~
where y is the shear rate,
~ is the shear stress,
aO is the yield stress (or yield value),
and ~ is the "plastic viscosity" (apparent viscosity
at infinite shear rate).
The yield stress is the minimum stress necessary to induce a
plastic deformation (flow) of the suspension. Thus, visualiz-
ing the suspension as a loose network of pigment particles, ifthe applied stress is lower than the yield stress, the
suspension behaves like an elastic gel and no plastic flow will
occur. Once the yield stress is overcome, the network breaks
at some points and the sample begins to flow, but with a very
high apparent viscosity. If the shear stress is much higher
than the yield stress, the pigments are partially shear-
deflocculate and the apparent viscosity decreases. Finally,
i~ the shear stress is much higher than the yield stress value,
the pigment particules are completely shear-deflocculated and
the apparent viscosity is very low, as if no particle inter-
action were present.
Therefore, the higher the yield stress of the
suspension, the higher the apparent viscosity at low shear rate
and the better is the physical stability of the product.
In addition to the problem of settling or phase
separation the non-aqueous liquid laundry detergents based on
liquid nonionic surfactants suffer from the drawback that the
nonionics tend to gel when added to cold water. This is a
particularly important problem in the ordinary use of European
household automatic washing machines where the user places the
laundry detergent composition in a dispensing unit (e.g. a
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dispensing drawer) of the machine. During the operation of the
machine the detergent in the dispenser is subjected to a stream
of cold water to transfer it to the main body of wash solution.
Especially during the winter months when the detergent composi-
tion and water fed to the dispenser are particularly cold, the
detergent viscosity increases markedly and a gel forms. As a
result some of the composition is not flushed completely off
the dispenser during operation of the machine, and a deposit of
the composition builds up with repeated wash cycles, eventually
requiring the user to flush the dispenser with hot water.
The gelling phenomenon can also be a problem whenever
it is desired to carry out washing using cold water as may be
recommended for certain synthetic and delicate fabrics or
fabrics which can shrink in warm or hot water.
Partial solutions to the gelling problem in aqueous,
substantially builder-free compositions have been proposed and
include, for example, diluting the liquid nonionic with certain
viscosity controlling solvents and gel-inhibiting agents, such
as lower alkanols, e.g. ethyl alcohol (see U. S. Patent No.
3,953,380), alkali metal formates and adipates (see U. S. Patent
No. 4,368,147), hexylene glycol, polyethylene glycol, etc.
In addition, these two patents each disclose the
use of up to at most about 2.5% of the lower alkyl (Cl-C4)
etheric derivatives of the lower (C2-C3) polyols, e.g. ethylene
glycol, in these aqueous liquid builder-free detergents in
place of a portion of the lower alkanol, e.g. ethanol, as a
viscosity control solvent. To similar effect are U. S. Patents
Nos. 4,111,855 and 4,201,686. However, there is no disclosure
or suggestion in any of these patents that these compounds,
some of which are commercially available under the tradename
Cellosolve ~ , could function effectively as viscosity control
~ - 5 -
62301-1370
639
and gel-preventing agents for non-aqueous liquid nonionic
surfactant compositions, especially such compositions containing
suspended builder salts, such as the polyphosphate compounds,
and especially particularly such compositions which do not
depend on or require the lower alkanol solvents as viscosity
control agents.
Furthermore, British Patent Specification 1,600,981
mentions that in non-aqueous nonionic detergent compositions
containing builders suspended therein with the aid of certain
dispersants for the builder, such as finely divided silica
and/or polyether group containing compounds having molecular
weights of at least 500, it may be advantageous to use mixtures
of nonionic surfactants, one of which fulfills a surfactant
function and the other of which both fulfills a surfactant
function and reduces the pour point of the compositions. The
former is exemplified by C12-C15 fatty alcohols with 5 to 15
moles of ethylene and/or propylene oxide per mole. The other
surfactant is exemplified by linear C6-C8 or branched C8-C
fatty alcohols with 2 to 8 moles ethylene and/or propylene
oxide per mole. Again, there is no teaching that these low
carbon chain compounds could control the viscosity and prevent
gelation of the heavy duty non-aqueous liquid nonionic
surfactant compositions with builder suspended in the nonionic
liquid surfactant.
It is also known to modify the structure of nonionic
surfactants to optimize their resistance to gelling upon
contact with water, particularly cold water. As an example of
nonionic surfactant modification one particularly successful
result has been achieved by acidifying the hydroxyl moiety
X
.
39
62301-1370
end group of the nonionic molecule. The advantages of
introducing a carboxylic acid at the end of the nonlonic
lnclude gel inhibition upon dilution; decreasing the nonionlc
pour polnt; and formation of an anionic surfactant when
neutralized in the washing liquor. INonionic structure
optimization for minimizing gelation is also known, for
example, controlling the chain length of the hydrophobic-
lipophllic moiety and the number and make-up of alkylene oxide
(e.g. ethylene oxide) units of the hydrophlllic moiety. For
example, it has been found that a C13 fatty alcohol ethoxylated
with 8 moles of ethylene oxide presents only a limited tendency
to gel formation.
Neverthele~s, still further improvements are desired
in the stability, viscoslty control and gel inhibitlon of non-
aqueous llquid detergent compositions.
This invention seeks to formulate highly built heavy
duty non-aqueous liquid nonionic surfactant laundry detergent
composltions whlch can be poured at all temperatures and which
can be repeatedly dispersed from the dispensihg unit of
European style automatic laundry washlng machines without
fouling or plugging of the dispenser even during the winter
months.
This invention further seeks to provlde non-gelling,
~table, low vi co~ity suspensions of heavy duty
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62301-1370
tripolyphosphate built non-aqueous liquid nonionic laundry
detergent composition which include an amount of a low
molecular weight amphiphilic compound sufficient to decrease
the viscosity of the composition in the absence of water and
upon contact with cold water.
The present invention provides a liquid laundry
detergent-bleaching composition cornprising a liquld nonionic
surfactant, a water soluble inorganic peroxide salt bleaching
agent, an effective amount of a connpound which is an inhibitor
of the enzyme-induced decomposition of the peroxide salt
bleaching agent and a bleach activator which will react with
the bleaching agent in an aqueous wash bath to form a
peroxyacid bleaching agent at a temperature of about 40C or
less. In some preferred embodiments one can also add to the
liquid nonionic surfactant composition an amount of a low
molecular weight amphiphilic compound, particularly, mono-, di-
or tri(lower ~C2 to C3) alkylene)glycol mono(lower (C1 to C5)
alkyl)ether, effective to inhibit gelation of the nonionic
surfactant in the presence of cold water.
The present invention may additionally provide a
liquid heavy duty laundry composition composed of a suspension
of a builder salt in a liquid nonionic surfactant wherein the
composition includes an amount of a lower (C2 to C3) alkylene
glycol mono(lower) (C1 to C53 alkyl eth~r to decrease the
viscosity of the composition in the absence of water and upon
the contacting of the composition with water.
The present invention may further provide a non-
aqueous liquid cleaning composition which remains pourable at
temperatures below about 5C and which does not gel when
contacted with or added to water at temperatures below about
20C, the composition being composed of a liquid nonionic
,2 i,
~ 8
.~.~
;3~
62301-1370
surfactant and C2 to C3 alkylene glycol mono(C1 to C5)alkyl
ether and being substantially free of water.
The invention aclditionally provides a non-aqueous
liquid detergent composition capable of washing and bleaching
soiled fabrics at temperatures as low as about 40C or less
which comprises a liquid nonionic surfactant, a mono or poly(C2
to C3)alkylene glycol mono~C1 to C5)alkyl ether, a water-
soluble inorganic peroxide bleaching agent, a bleach activator
to lower the temperature at which the bleaching agent will
liberate hydrogen peroxide in aqueous solution, and from about
0.01 to 0.4 percent by weight, based on the total composition,
of an hydroxylamine salt capable of inhibiting the enzyme-
induced decomposition of the bleaching agent, said enzyme being
present in the soiled fabrics.
The invention also provides a non-aqueous liquid
detergent composition capable of washing and bleaching soiled
fabrics at temperatures as low as about 40C. or less which
comprises a liquid phase comprising nonionic surfactant and a
mono or poly (C2 to C3) alkylene glycol mono (C1-C5) alkyl
ether in an amount of 30 to 70%, a water-soluble inorganic
peroxide bleaching agent in an effective amount of up to 25%, a
bleach activator to lower the temperature at which the
bleaching agent will liberate hydrogen peroxide in aqueous
solution in an effective amount of up to 10%, proteolytic
enzyme in an amount of from about 0.7 to 2 percent by weight
and from about 0 01 to 0.4 percent by weight, based on the
total composition, of an hydroxylamine salt capable of
inhibiting the enzyme-induced decomposition of the bleaching
agent, said enzyme being present in the soiled fabrics.
8a
~ 6~9 62301~~.370
The invention further provides a non-aqueous liquid
laundry detergent-bleaching composition comprising a liquid
phase comprising liquid nonionic surfactant, a detergent
builder salt suspended in the liquid phase, an effective amount
of a water soluble inorganic peroxide salt bleaching agent
selected from the group consisting of perborate, percarbonate,
perphosphate and persulfate, an effective amount of a bleach
activator compound which will react with the bleaching agent in
an aqueous wash bath to form a peroxy bleach agent at a
temperature of about 40C. or less, an effective amoun~ of a
proteolytic enzyme, and an effective amount in the range of
from about 0.01 to about 0.4% by weight of the composition of
an hydroxylamine salt to inhibit enzyme-induced decomposition
of the peroxide salt bleaching agent.
The invention further provides a non-agueous liquid
laundry detergent composition consisting essentially of
about 40 to 60~ by weight of a liquid nonionic surfactant
and a viscosity-controlling and gel-inhibiting compound of the
formula
R'
RO~CHCH20)nH
where R is alkyl of 2 to 5 carbon atoms,
R' is hydrogen or methyl, and
n is a number from 2 to 4 on average,
wherein the weight ratio of nonionic surfactant to said
viscosity-controlling and gel-inhibi~ing compound being from
50:1 to 2:1,
about 20 to 50~ by weight of detergent builder salt
suspended in the liquid phase,
about 2 to 20~ by weight of an alkali metal perborate
bleaching agent
8b
`,
39
62301-1370
about 0.1-3~ by weight of te~raacetylene diamine bleach
activator,
about 0.7 to 2% by weight of proteolytic enzyme, and
about 0.01 to 0.4% by weight of hydroxylamine salt capable
of inhibiting the enzyme induced decomposition of the bleaching
agent.
The invention may also provide a method for
dispensing a liquid nonionic laundry detergent composition into
and~or wi~h cold water without undergoing
8c
~ 3~39 62301-1370
gelation. In particular, a method is provided for filling a
container with a non-aqueous liquid laundry detergent composi
tion in which the detergent is composed, at least predominantly,
of a liquid nonionic surface active agent and for dispensing
the composition from the container into an aqueous wash bath,
wherein the dispensing is effected by directing a stream of
unheated water onto the composition such that the composition
is carried by the stream of water into the wash bath. By
including a low molecular weight amphiphilic compound, i.e.
a lower C2 to C3 alkylene glycol mono(lower)(Cl to C5)alkyl
ether, the composition can be easily poured into the container
even when the composition is at a temperature below room
temperature. Furthermore, the composition does not undergo
gelation when it is contacted by the stream of water and it
readily disperses upon entry into the wash bath.
As will be seen below the liquid detergent composi-
tions often include, in addition to the detergent active
ingredient, one or more detergent additives or adjuvants. One
of the more important of these, in terms of consumer appeal and
actual cleaning benefit, is the class of bleach agents,
especially the oxygen bleaches, of which sodium perborate
monohydrate is a particularly preferred example. It is well
known in the art that in solution, the persalt oxygen bleach
releases hydrogen peroxide as the active oxidizing agent.
However, hydrogen peroxide is readily decomposed by catalase,
an enzyme always present in natural soils and stains. This
decomposition occurs even in the presence of bleach activators,
as the rate of reaction between hydrogen peroxide and the
activator is slower than the decomposition of hydrogen peroxide
by catalase. The activity of catalase is very high, even at
room temperature, and a substantial quantity of active oxygen
is lost before catalase can be deactivated by increasing the
_ g _
_ 62301-1370
temperature of the washing bath.
One approach to solving this problem has been to use
an excessive amount of perborate or other peroxide bleaching
agent, e.g. an amount generally 2 to 4 or more times that
which would be required to effectively bleach the soil or stain
in the absence of peroxide decomposing enzyme and also 2 to 4
or more times molar excess relative to the number of moles oE
bleach activator.
It has also been proposed to carry out the bleaching
with an aqueous solution of peroxide bleaching agent in the
presence of a compound capable of inhibiting enzyme-induced
decomposition of the bleaching agent. Thus, U. S. Patent
3,606,990 to Gobert and Mouret and assigned to Colgate-
Palmolive Company discloses a relatively wide range of inhibitor
compounds, including, for example, hydroxylamine salt, hydrazine
and phenylhydrazine and their salts, substituted phenols and
polyphenols, and others, as well as various detergent composi-
tions incorporating the water soluble inorganic peroxide
bleaching agent and the inhibitor compound. However, there is
no teaching of liquid detergent compositions which incorporate
the inhibitor compounds nor is there a teaching that the
inhibitor compounds would be effective in compositions contain-
ing a bleach activator in addition to the peroxide bleach.
Furthermore, this patent states in column 7, lines 25-29 that
in the case of hydroxylamine sulfate the effective amount of
inhibitor compound is from about 0.5 to about 2 percent by
weight of total composition.
It has now been discovered that in the detergent
liquid compositions of this invention containing a water soluble
inorganic peroxide bleaching agent of the persalt type the
incorporation of very limited amounts of less than about 0.5%,
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_ ~rr~ 9 62301-1370
for example, 0.01 to about 0.45~, can effectively inhibit
anzyme-induced decomposition of the bleaching agent. It has
been further discovered that hydroxylamine sulfate is highly
stable in the composition and does not at all interfere with
activation of the bleaching system by conventional persalt
bleach activators.
Therefore, in accordance with a still further aspect
of the present invention there is provided a liquid heavy duty
laundry detergent composition which includes a water soluble
inorganic peroxide bleaching agent and an effective amount of a
compound which ean inhibit enzyme-induced decomposition of the
bleaching agent, especially in an amount of less than about
0.5% by weight of the composition, and preferably with an
activator for activating the bleaching agent.
Other features and specific embodiments of the
invention will be apparent and the in~-ention may be more readily -
understood from the following detailed description.
The nonionic synthetic organic detergents employed
in the practice of the invention may be any of a wide variety
of such compounds, which are well known and, for example, are
described at length in the text Surfaee Active Agents, Vol. II,
by Sehwartz, Perry and Bereh, published in 1958 by Interscience
Publishers, and in McCutcheon's Detergents and Emulsifiers,
1969 Annual. Usually,the nonionic detergents are poly-lower
alkoxylated lipophiles wherein the desired hydrophile-lipophile
balance is obtained from addition of a hydrophilie poly-lower
alkoxy group to a lipophilie moiety. A preferred class of the
nonionie detergent employed is the poly-lower alkoxylated higher
alkanol wherein the alkanol is of 10 to 18 earbon atoms and
wherein the number of mols of lower alkylene oxide (of 2 or 3
carbon atoms) is from 3 to 12. of such materials it is
preferred to emp:Loy those wherein the higher alkanol is a higher
-- 11 --
~. '
~ 9 62301-1370
fatty alcohol of 10 to 11 or 12 to 15 carbon atoms and which
contain from 5 to 8 or 5 to 9 lower alkoxy groups per mol.
Preferably, the lower alkoxy is ethoxy but in some instances,
it may be desirably mixed with propoxy, the latter, if present,
usually, but not necessarily, being a minor (less than 50%)
proportion. Exemplary of such compounds are those wherein the
alkanol is of 12 to 15 carbon atoms and which contain about 7
ethylene oxide groups per mol, e.g. Neodol 25-7 and Neodol
23-6.5, which products are made by Shell Chemical Company, Inc.
The former is a condensation product of a mixture of higher
fatty alcohols averaging about 12 to 15 carbon atoms, with about
7 moles of ethylene oxide and the latter is a corresponding
mixture wherein the carbon atom content of the higher fatty
alcohol is 12 to 13 and the number of èthylene oxide groups
present averages about 6.5. The higher alcohols are primary
alkanols. Other examples of such detergents include Tergitol
15-S-7 and Tergitol 15-S-9, both of which are linear secondary
alcohol ethoxylates made by Union Carbide Corp. The former is
mixed ethoxylation product of 11 to 15 carbon atoms linear
secondary alkanol with seven mols of ethylene oxide and the
latter is a similar product but with nine mols of ethylene oxide
being reacted.
Also useful in the present compositions as a component
of the nonionic detergent are higher molecular weight nonionics,
such as Neodol 45-11, which are similar ethylene oxide condensa-
tion products of higher fatty alcohols, with the higher fatty
alcohol being of 14 to 15 carbon atoms and the number of
ethylene oxide groups per mol being about 11. Such products
are also made by Shell Chemical Company. Other useful nonionics
are represented by the well-known commercially available Plurafac
Trade-mark
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~ 62301-1370
series which are the reaction product of a higher linear alcohol
and a mixture of ethylene and propylene oxides, containing a
mixed chain of ethylene oxide and propylene oxide, terminated by
a hydroxyl group. Examples include Plurafac R~30 (a C13-C15
fatty alcohol condensed with 6 moles ethylene oxide and 3 moles
propylene oxide), Plurafac RA40 (a C13-C15 fatty alcohol
condensed with 7 moles propylene oxide and 4 moles ethylene
oxide), Plurafac D25 (a C13-C15 fatty alcohol condensed with 5
moles propylene oxide and 10 moles ethylene oxide), and
Plurafac B26.
Generally, the mixed ethylene oxide-propylene oxide
fatty alcohol condensation products can be represented by the
yeneral formula RO(C2H4O)x(C3H6O) H, where R is straight or
branched primary or secondary aliphatic hydrocarbon, preferably
alkyl or alkenyl, of from 6 to 20, preferably 10 to 18,
especially preferably 14 to 18 carbon atoms, x is a number of
from 2 to 12, preferably 4 to 10, and y is a number of from 2
to 7, preferably 3 to 6.
Another group of liquid nonionics are available from
Shell Chemical Company, Inc. under the Dobanol trade-mark:
Dobanol 91-5 is an ethoxylated Cg-Cll fatty alcohol with an
average of 5 moles ethylene oxide; Dobanol 25-7 is an
ethoxylated C12-C15 fatty alcohol with an average of 7 moles
ethylene oxide; etc.
In the preferred poly-lower alkoxylated higher
alkanols, to obtain the best balance of hydrophilic and
lipophilic moieties the number of lower alkoxies will usually
be from 40% to 100% of the number of carbon atoms in the higher
alcohol, preferably 40 to 60% thereof and the nonionic detergent
will preferably contain at least 50% of such preferred poly-
Trade-mark
- 13 -
62301-1370
~ ~9~3639
lower alkoxy higher alkanol. Higher molecular weight alkanols
and various other normally solid nonionic detergents and
surface active agents may be contributory to gelation of
- 13a -
39
. . .
the liquid detergent and consequently, will preferably be
omitted or limited in quantity in the present compositions,
although minor proportions thereof may be employed for their
cleaning properties, etc. With respect to both preferred
and less preferred nonionic detergents the alkyl groups present
therein are generally linear although branching may be tolerated,
such as at a carbon next to or two carbons removed from the
terminal carbon of the straight chain and away from the ethoxy
chain, if such branched alkyl is not more than three carbons .
in length. Normally, the proportion of carbon atoms in such
a branched configuration will be minor rarely exceeding 20%
of the total carbon atom content of the alkyl. Similarly~
although linear alkyls which are terminally joined to the
ethylene oxide chains are highly preferred and are considered
to result in the best combination of detergency, biodegradability
and non-gelling characteristics, medial or secondary joinder
to the ethylene oxide in the chain may occur. It is usually
in only a minor proportion of such alkyls, generally less
than 20% but, as is in the cases of the mentioned Terigtols,
may be greater. Also, when propylene oxide is present in
the lower alkylene oxide chain, it will usually, but not
necessarily, be less than 20/, thereof and preferably less
than 10/~ thereof.
l~hen greater proportions of non-terminally alkoxylated
alkanols, propylene oxide-containing poly-lower alkoxylated
alkanols and less hydrophile-lipophile balanced nonionic
detergent than mentioned above are employed and when other
nonionic detergents are used instead of the preferred nonionics
recited herein, the product resulting may not have as good
detergency, stability, viscosity and non-gelling properties
as the preferred compositions but use of the viscosity and
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gel controlling compounds of the invention can also improve
the properties of the detergents based on such nonionics.
In some cases, as when a higher molecular weight polylower
alkoxylated higher alkanol is employed, often for its detergency,
the proportion thereof will be regulated or limited as in
accordance with the results of various experiments, to obtain
the desired detergency and still have the product non-gelling
and of desired viscosity. Also, it has been found that it
is only rarely necessary to utilize the higher molecular
weight nonionics for their detergent properties since the
preferred nonionics described herein are excellent detergents
and additionally, permit the at~ainment of the desired viscosity
in the liquid detergent without gelation at low temperatures.
Mixtures of two or more of these liquid nonionics can also
be used and in some cases advantages can be obtained by the
use of such mixtures.
As mentioned above, the structure of the liquid nonionic
surfactant may be optimized with regard to their carbon chain
length and configuration (e.g. linear versus branched chains,
etc.) and their content a~d distribution of alkylene oxide
units. Extensive research has shown that these structural
characteristics can and do have a profound effect on such
properties of the nonionic as pour point, cloud point, viscosity,
gelling tendency, as well, of course, as on detergency.
Typically most commercially available nonionics
have a relatively large distribution of ethylene oxide (EO)
and propylene oxide (PO) units and of the lipophilic hydrocarbon
chain length, the reported EO and PO contents and hydrocarbon
chain lengths being overall averages. This "polydispersity"
of the hydrophilic chains and lipophilic chains can have
great importance on the product properties as can the specific
values of the average values. The relationship between "poly-
~ ~ 63~
dispersity" and specific chain lengths with product propertiesfor a well-defined nonionic can be shown by the following
data for the "Surfactant T" series of nonionics available
from British Petroleum. The Surfactant T nonionics are obtained
by ethoxylation of secondary C13 fatty alcohols having a
na-row E0 distribution and have the following physical char-
acteristics:
Cloud Point (1% sol)
E0 Content Pour Point (C) (C)
Surfactant T5 5 <-2 <25
Surfactant T7 7 -2 38 .
Surfactant T9 9 6 58
Surfactan; Tl2 12 20 88
To assess the impact of E0 distribution, a "Surfactant
T8" was artificially prepared in two ways:
a. l:l mixture of T7 and T9 (T8a)
b. 4 3 mixture of T5 and Tl2 (T8b)
The following properties were found:
E0 Content Pour Point Cloud Point (1% sol'n~
(av~) (C) (C)
l Surfactant T8a 8 2 48
i Surfactant T8b 8 15 <20
¦ From these results, the following general obser~ations
¦ can be made:
¦ l. T8a corresponds closely to an actual surfactant
¦ T8 as it interpolates well between T7 and T9 for both pour
¦ point and cloud point.
¦ 2. 1`8b which is highly polydisperse and would be
¦ generally unsatisfactory in view of its high pour point and
low cloud point temperatures.
-16-
~ 9
3. The properties of T8a are basically additive
between T7 and T9 whereas for T8b the pour point is close
to the long E0 chain (T12) while the cloud point is close;
to the short EO chain (T5).
The viscosities of the Surfactant T nonionics were
measured at 20%, 30~/O, 40%, 50~/O, 60%, 80~/o and 100% nonionic
concentrations for T5, T7, T7/T9 (1:1), T9 and T12 at 25C
with the following results (when a gel is obtained, the viscosity
is the apparent viscosity) at lOO~sec:
Nonionic Viscosity (mPa-s)
T5 ¦ T7 ¦ T7/T9 T9 T12
100 ~ ~36 63 61 149
104 112 165
750 78 188 239 32200
4000 123 233 634 89100
2050 96 149 211 187
630 58 38 27
170 78 28 100
_. . . =~ =. ~ , _ ~ _ __
From these results, it may be concluded that ~urfactant
T7 is less gel-sensitive than T5, and T9 is less gel-sensitive
than T12; moreover, the mixture of T7 and T9 (T8) does not
gel, and its viscosity does not exceed 225 m Pa s. T5 and
T12 do not form the same gel structure.
Although not wishing to be bound by any particular
theory, it is presumed that these results may be accounted
for by the following hypothesis:
For T5: with only 5 E0, the hydrodynamic volume
of the E0 chain is almost the same as the hydrodynamic volume
of the fatty chain. Surfactant molecules can accordingly
arrange themselves to form a lamellar structure.
For T12: with 12 E0, the hydrodynamic volume of
the eo chain is greater than that of the fatty chain. When
molecules try to arrange themselves together, an interface
curvature occurs and rods are obtained. The superstructure
is then hexagonal; with a longer EO chain, or with a higher
~;~9~9
. .
hydratation, the interface curvature can be such that actual
spheres are obtained, and the arrangement of the lowest energy
is a face-centered cubic latice.
From T5 to T7 (and T8), the interface curvat~re
increases, and the energy of the lamellar structure increases.
As the lamellar structure loses stability, its melting temperatur~
is reduced.
From Tl2 to T9 (and T8), the interface curvature
decreases, and the energy of the hexagonal structure increases
(rods become bigger and bigger). As the loss in stability
occurs, the structure melting temperature is also reduced.
Surfactant T8 appears to be at the critical point
at which the lamellar structure is destabilized, i.e. the
hexagonal structure is not yet stable enough and no gel is
obtained during dilution. In fact, a 50% solution of T8
will finally gel after two days, but the superstructure formation
is delayed long enough to allow easy water dispersability.
The effects of the molecular weight on physical
properties of the nonionics were also considered. Surfactant
T8 (l:l mixture of T7 and T9) exhibits a ~ood compromise
between the lipophilic chain (Cl3) and the hydrophilic chain
(E08), although the pour point and maximum viscosity on dilution
at 25C are still high.
The equivalent E0 compromise for ClO and C8 lipophilic
chains was also determined using the Dobanol 91-x serie~
from Shell Chemical Co., which are ethoxylated derivatives
of C9-Cll fatty alcohols (average: ClO); and Alfonic 610-y
series from Conoco which are ethoxylated derivatives of C6-Clo
fatty alcohols (avera~e Cg); x and y represent the E0 weight
percenta~e.
The next table reports ~he physical characteristics
~ ~91)639 -
of the Alfonic 610-y and Dobanol 91-x series:
Nonionic # E0 Pour Point Cloud Pt. Max.n on dilution
(av~.) (C) (C)at 25C (~Pa-s)
Alfonic 610-50R 3 -15 Gel (60%)
Alfonic 610-60 4.4 -4 41 36 (60%)
Dobanol 91-5 5 -3 33 Gel (70%)
Dobanol 91-5T 6 +2 55 126 (50%)
Dobanol 91-8 8 ~6 81 Gel (50%)
Dobanol 91-5 and Dobanol 91-8 are commercially available
products; Dobanol 91-5 topped (T) is a lab scale product:
it is Dobanol 91-5 from which free alcohol has been removed.
As the lowest ethoxylation ~embers are also removed, the
average E0 number is 6. Dobanol 91-5T provides the ~est
results of C10 lipophile chain as it does not gel at 25C.
The 1/~ cloud point (55C) is higher than for surfact~nt T8
(48C). This is presumably due to the lower molecular weight
since the mixture entropy is higher. Alfonic 610-60 provides
the best results of the C8 lipophile chain series.
A summary of the best E0 contents for each tested
lipophilic chain length is provided in the following table:
Cloud Pt.
Nonionic # C # E0 Pour Pt. (1% soln) Max ~ on dil.~%)
(C) (C) at 25C ~mPa s)
Surfactant T8 13 8 +2 48 223 (50%)
Dobanol 91-5T 10 6 +2 55 126 (50%)
Alfonic 610-60 8 4.4 -4 41 36 (60%)
From this data, the following conclusions were reached:
Pour points: as the nonionic molecular weight decreases,
its pour points decrease too. The relatively high pour point
of Dobanol 91-5T can be accounted for by the higher polydispersity .
This waS ~lso noticed Eor T8a and T8b, i.e. the chain polydispersi Y
increases the pour point.
~ 39
Cloud points: theoretically, as the number of molecules
increases (if the rnolecular weight decreases), the mixing
entropy is higher, so the cloud point would increase as the
molecular weight decreases. It is actually the case ~rom
Surfactant T8 to Dobanol 91-5T but it has not been confirmed
with Alfonic 610-60. Here it is presumed that the lipophilic
hydrocarbon chain polydispersity is responsible for the theoretica 11
too low cloud point. The relatively large amount of C10-E0
present reduces the solubility.
Maximum viscosity on dilution at 25C: none of these
nonionics gel at 25C when they are diluted with water. (
The maximum viscosity decreases sharply with the molecular
weight. As the nonionic molecular weight decreases, the
less efficient becomes the hydrogen bridges. Unfortunately,
too low molecular weight nonionics are not suitable for laundry
washing: their micellar critical concentration (MCC~ is
too high, and a true solution, with only a limited detergency
would be obtained under practical laundry conditions.
With this information, the present inventors continued
their studies on the effects of the low molecular weight
amphiphilic compounds on the rheological properties of liquid
nonionic detergent cleaning compositions. These studies
revealed that while it is possible to lower the pour point
of the composition and obtain some degree of gel inhibition
by using a short chain hydrocarbon, e.g. about Cg, with a
short chain ethylene oxide substitution, e.g. about 4 moles,
as am?hiphilic additive, such as Alfonic 610-60, these additives
do not significantly contribute to the overall laundry cleaning
performance and still do not exhibit overall satisfactory
viscosity control over all norrnal usage conditions.
- 1290~39 - I
I The present invention is, therefore, based, at least
¦in part, on the discovery that the low molecular weight amphiphili c
¦compounds which can be considered to be analogous in chemical
¦ structure to the ethoxylated and/or propoxylated fatty alcohol
¦nonionic surfactants but which have short hydrocarbon chain
¦lengths (Cl-C5) and a low content of alkylene oxide, i.e.
¦ ethylene oxide and/or propylene oxide (about 1 to 4 EO/PO
units per molecule) function e~fectively as viscosity control
and gel-inhibiting agents for the liquid nonionic surface
active cleaning agents.
The viscosity-controlling and gel-inhibiting amphiphilic
compounds used in the present invention can be represented
by the following general formula
R'
RO(CHCH20)nH
where R is a Cl-Cs, preferably C2 to Cs, especially
preferably C2 to C4, and particularly C4 alkyl group,
R' is H or CH3, preferably H, and n is a number of
from about 1 to 4, preferably 2 to 4 on average.
Preferred examples of suitable amphiphilic compounds include
ethylene glycol monoethyl ether (C2Hs-O-CH2CH20H), and diethylene
glycol monobutyl ether (C4Hg-O-(CH2CH20)2H). Diethylene
glycol monoethyl ether is especially preferred and, as will
be shown below, is uniquely effective to control viscosity.
~'hile the amphiphilic compound, particularly diethylene
glycol monobutyl ether, can be the only viscosity control
and gel inhibiting additive in the invention compositions
further improvements in the rheological properties of the
anhydrous liquid nonionic surfactant compositions can be
obtained by including in the composition a small amount of
a nonionic surfactant which has been modified to convert
~ ~ 9 ~2~ ~lg1370
a ~ree hydroxyl group thereof to a moiety having a free carboxyl
grou~ such as a ~artial c.stcr O~r a nonionic surfactant and a
polycarboxylic acicl and/or an acidic organic phosphorus compound
having an acidic - PO~I group, such as a partial ester of phos-
phorous acid and an alkanol.
~ s disclosed in our Canadian Patent application Serial
No. ~78,379, filed April 9, 1985, the free carboxyl group modi-
ficd nonionic surfactants, which may he broadly characterizcd
as ~olycther carboxylic acids, function to lower ~he temperature
at whicll the liquid nonionic forms a gel with water. The acidic
polyether compound can also decrease the yield stress oi such
dispcrsions, aiding in their dispensibility, without a corres-
ponding decrease in their stability against settling. Suitable
polycther carboxylic acids contain a grouping of the formula
~OCH ~CH2~p~CH~C~l2~q~Y~Z~COOH where R is hydrogen or methyl,
R2 Cll3
Y is oxygen or sulfur, Z is an organic linkage, p is a positive
nul~er of from about 3 to about 50 and q is zero or a positive
number of up to 10. Specifie examples include the half-ester of
Plurafac R~30 with succinic anhydride, the half ester of Dobanol
25-7 with succinic anhydride, the half ester of Dobanol 91-5
with succinic anhydride, etc. Instead o~ a succinic acid
anhydride, other polycarboxylic acids or anhydrides may be used,
e.g. maleic acid, maleic anhydride, glutaric acid, malonic acid,
succinic acid, phthalic acid, phthalic anhydride, citric acid,
etc. rurthermore, other linkages may be uscd, such as ethcr,
thiocthcr or urcthane linkages, formed by conventional rcactions.
ror instancc, to form an ether linkage, the nonionic surfactant
may be treated with a strong base ~to convert its O~ group to an
ONa ~roul~ for in.stancc) and thcn rcactcd with a halocarboxylic
acid such as chloroacetic acid or chloxopro-
- 22 -
39
62301-1370
pionic acid or the corresponding bromo compound. Thus, the
resulting carboxylic acid may have the formula R-~-ZCOOH where
R is the residue of a nonionlc surfactant (on removal of a
terminal OH), Y is oxygen or sulfur and Z represents an organic
linkage such as a hydrocarbon group of, say, one to ten carbon
atoms which may be attached to the oxygen (or sulfur) of the
formula directly or by means of an intervening linkage such as
an oxygen-containing linkage, e.g. a O
or O , etc.
-C-NH-
The polyether carboxylic acid may be produced from a
polyether which is not a nonionic surfactant, e.g. it may be
made by reaction with a polyalkoxy compound such as
polyethylene glycol or a monoester or monoether thereof which
does not have the long alkyl chain characteristic of the
nonionic surfactants. Thus, R may have the formula R2
R (OCH-CH2)n~
where R2 is hydrogen or methyl, R1 is alkylphenyl or alkyl or
other chain terminating group and "n" is at least 3 such as 5
to 25. When the alkyl of R1 is a higher alkyl, R is a residue
of a nonionic surfactant. As indicated above R1 may lnstead be
hydrogen or lower alkyl (e.g. methyl, ethyl, propyl, butyl) or
lower acyl le.g. acetyl, etc.). The acidic polyether compound
if present in the detergent composition, is preferably added
dissolved in the nonionic surfactant.
The carboxylic acid used may also be a polyalkoxy
carboxylate or N-acyl sarcoslnate a~ descrlbed and listed in
~irk-Othmer, "~ncyclopedia of Chemical Technology", 3rd
Edition, Vol. 22 (1983), pages 348-349.
~ 23 -
~9~6~9
62301-1370
Another useful class of supplemental anti-yelling
agent are the C6 to C14 alkyl or alkenyl dlcarboxylic
anhydride, such as, for example, octenylsuccinic anhydride,
octenylmaleic anhydride, dodecylsuccinic anhydride, etc. These
compounds may be used together with or in place of part or all
of the polyether carboxylic acid an~tl-gelling agents.
- 23~-
~L~9q~63~ 62301-1370
As disclosed ln our Canadian Patent Application
Serial No. 478,380, filed April 4, 1985, the acidic organic
phosphorus compound having an acidic - POH group can increase
the stabillty of the suspension of builderr especia`lly
polyphosphate builders, in the non-aqueous li~uid nonionic
surfactant.
The acidic organic phosphorus compound may be, for
instance, a partial ester of phosphoric acid and an alcohol
such as an alkanol which has a lipophilic character, having,
for instance, more than 5 carbon atoms, e.g. 8 to 20 carbon
atoms.
A specific example is a partial ester of phosphoric
acid and a C16 to C18 alkanol (Empiphos* 5632 from Marchon); it
is made up of about 35~ monoester and 65% diester.
The inclusion of quite small amounts, for example,
from about 0.05 to 0.3~ by weight of the composition, of the
acidic organic phosphorus compound makes the suspension
significantly more stable against settling on standing but
remains pourable, presumably, as a result of increasing the
yield value of the suspension, but decreases its plastic
viscosity. It is believed that the use of the acidic
phosphorus compound may result in the formation of a high
energy physical bond between the -POH portion of the molecule
and the surfaces of the inorganic polyphosphate builder so that
these surfaces take on an organic character and become more
compatible with ~he nonionic surfactant.
The acidic organic phosphorous compound may be
selected from a wide variety of materials, in addition to the
*Trade-mark 24
~. .
62301-1370
partial esters of phosphoric acid and alkanols mentioned above.
Thus, one may employ a partial ester of phosphoric or
phosphorous acid with a mono or po].yhydric alcohol such as
hexylene glycol, ethylene glycol, cli- or tri ethylene glycol or
higher polyethylene
~ 24a
62301-1370
glycol, polypropylene glycol, glycerol, sorbitol, mono or
diglycerides of fatty aclds, etc. ln whlch one, two or more of
the alcohollc OH groups of the molecule may be esterlfled with
the phosphorus acld. The alcohol may be a nonlonic surfactant
such as an ethoxylated or ethoxylateclpropoxylated higher
alkanol, higher alkyl phenol, or hlgher alkyl amide. The -POH
group need not be bonded to the organlc portion of the molecule
through an ester llnkage; instead lt may be directly bonded to
carbon ~as in a phosphonic acid, such as a polystyrene in which
some of the aromatic rlngs carry phosphonlc acld or phosphlnic
acid groups; or an alkylphosphonlc acld, such as propyl or
laurylphosphonic acld) or may be connected to the carbon
through other intervening llnkage (such as linkages through 0,
S or N atoms). Preferably, the carbon-phosphorus atomic ratio
ln the organic phosphorus compound i5 at least about 3~1, such
as 5.1, 10.1, 20~1, 30~1 or 40~1. Among sulta~le compounds are
the phosphate ester surfactants described and listed in Kirk-
Othmer Encyclopedia of Chemical Technology", 3rd Edition, Vol.
22 (1983), pages 359-361.
The invention detergent composition may also and
preferably does lnclude water soluble detergent builder salts.
Typical suitable builders lnclude, for example, those disclosed
in U.S. Patents 4,316,812, 4,264,466, and 3,630,929. Water-
soluble inorganic alkaline builder salts which can be used
alone with the detergent compound or in admixture with other
builders are alkali metal carbonate, borates, phosphates,
polyphosphates, bicarbonates, and silicates. (Ammonium or
substituted am~onium salts can also be used.) Speclfic
- 25 -
~G
~ 9 62301-1370
examples of such salts are sodium tripolyphosphate, sodium
carbonate, sodium tetraborate, sodium pyrophosphate, potassium
pyrophosphate, sodium bicarbonate, potassium tripolyphosphate,
sodium hexametaphosphate, sodium sesquicarbonate, sodium mono
and diorthophosphate, and potassium bicarbonate. Sodium
tripolyphosphate (TPP) is especially
- 25a-
L~
~ 9 62301-1370
preferred. The alkali metal silicates are useful builder
salts which also function to make the composition anticorrosive
to washing machine parts. Sodium silicates of Na2O/SiO2 ratios
of from 1.6/1 to 1/3.2 especially about 1/2 to 1/2.8 are
preferred. Potassium silicates of the same ratios can also be
used.
Another class of builders useful herein are the water-
insoluble aluminosilicates, both of the crystalline and
amorphous type. Various crystalline zeolites (i.e. alumino-
silicate~are described in British Patent 1,504,168, U. S. Patent
4,409,136 and Canadian Patents 1,072,835 and 1,087,477. An
example of amorphous zeolites useful herein can be found in
Belgium Patent 835,351. The zeolites generally have the formula
( 2 )x tA12O3)y~(SiO2)z-WH2O
wherein x is 1, y is from 0.8 to 1.2 and preferably 1, z is from
1.5 to 3.5 or higher and preferably 2 to 3 and W is from 0 to 9,
preferably 2.5 to 6 and M is preferably sodium. A typical
zeolite is type A or similar structure, with type 4A
particularly preferred. The preferred aluminosilicates have
calcium ion exchange capacities of about 200 milliequivalents
per gram or greater, e.g. 400 meq/g.
Other materials such as clays, particularly of the
water-insoluble types, may be useful adjuncts in compositions
of this invention. Particularly useful is bentonite. This
material is primarily montmorillonite which is a hydrated
aluminum silicate in which about l/6th of the aluminum atoms
may be replaced by magnesium atoms and with which varying
amounts of hydrogen, sodium, potassium, calcium, etc., may be
loosely combined. The bentonite in its more purified form
(i.e. free from any grit, sand, etc.) suitable for detergents
invariably contains at least 50~ montmorillonite and thus its
- 26 -
~ .
.
~ 9 62301-1370
cation exchange capacity is at least about 50 to 75 meq. per
100 g. of bentonite. Particularly preferred bentonite are the
Wyoming or Western U. S. bentonites which have been sold as
Thixo-jels 1, 2, 3 or 4 by Georgia Kaolin Co. These bentonites
are known to soften textiles as described in British Patent
401,413 to Marriott and sritish Patent 461,221 to Marriott and
Dugan.
Examples of organic alkaline sequestrant builder salts
which can be used alone with the detergent or in admixture with
other organic and inorganic builders are alkali metal, ammonium
or substituted ammonium, aminopolycarboxylates, e.g. sodium and
potassium ethylene diaminetetraacetate (EDTA), sodium and
potassium nitrilotriacetates (NTA) and triethanolammonium N-(2-
hydroxyethyl)nitrilodiacetates. Mixed salts of these poly-
carboxylates are also suitable.
Other suitable builders of the organic type include
carboxymethylsuccinates, tartronates and glycollates. Of
special value are the polyacetal carboxylates. The polyacetal
carboxylates and their use in detergent compositions are
described in 4,144,226; 4,315,092 and 4,146,495. Other patents
on similar builders include 4,141,676; 4,169,934; 4,201,858;
4,204,8~2; 4,224,420; 4,225,685; 4,226,960; 4,233,422;
4,233,423; 4,302,564 and 4,303,777.
Since the compositions of this invention are generally
highly concentrated, and, therefore, may be used at relatively
low dosages, it is desirable to supplement any phosphate
builder (such as sodium tripolyphosphate) with an auxiliary
builder such as a polymeric carboxylic acid having high calcium
binding capacity to inhibit incrustation which could otherwise
be caused by formation of an insoluble calcium phosphate. Such
*
Trade-mark
- 27 -
~ 9 62301-1370
auxiliary builders are also well known in the art.
Various other detergent additives or adjuvants may
be present in the detergent product to give it additional
desired properties, either of functional or aesthetic nature.
Thus, there may be included in the formulation, minor amounts
of soil suspending or anti-redeposition agents, e.g. polyvinyl
alcohol, fatty amides, sodium carboxymethyl cellulose, hydroxy-
propyl methyl cellulose; optical brighteners, e.g. cotton,
amine and polyester brighteners, for example, stilbene,
triazole and benzidene sulfone compositions, especially
sulfonated substituted triazinyl stilbene, sulfonated naphtho-
triazole stilbene, benzidene sulfone, etc., most preferred are
stilbeneand triazole combinations.
Bluing agents such as ultramarine blue; en2ymes,
preferably proteolytic enzymes, such as subtilisin, bromelin,
papain, trypsin and pepsin, as well as amylase type enzymes,
lipase type enzymes, and mixtures thereof; bactericides, e.g.
tetrachlorosalicylanilide, hexachlorophene; fungicides; dyes;
pigments (water dispersible); preservatives; ultraviolet
absorbers; anti-yellowing agents, such as sodium carboxymethyl
cellulose, complex of C12 to C22 alkyl alcohol with C12 to C18
alkylsulfate; pH modifiers and pH buffers; color safe bleaches,
perfume, and anti-foam agents or suds-suppressors, e.g. silicon
compounds can also be used.
The bleaching agents are classified broadly, for
convenience, as chlorine bleaches and oxygen bleaches.
Chlorine bleaches are typified by sodium hypochlorite (NaOCl),
potassium dichloroisocyanurate (59% available chlorine), and
trichloroisoisocyanuric acid (85~ available chlorine). The
oxygen bleaches are preferred and are represented by per-
compounds which liberate
- 28 -
X
'
-
hydrogen peroxide in solution, i.e. compounds containing
hydrogen peroxide or inorganic perhydrates which, when dissolved,
liberate hydrogen peroxide enclosed in their crystal lattice.
Preferred examples include sodium and potassium perborates,
percarbonates, and perphosphates, and potassium monopersulfate.
The perborates, particularly sodium perborate monohydrate,
is especially preferred.
Hydrogen peroxide and the precursors which liberate
it in solution are good oxidizing agents for removing certain
stains from cloth, especially stains caused by wine, tea,
coffee, cocoa, fruits, etc.
Hydrogen peroxide and its precursors have been found
in general to bleach quickly and most effectively at a relatively
high temperature, e.g. about 80C to 100C. However, such
compounds tend to decompose and liberate gaseous oxygen at
lower temperatures. The liberation of gaseous oxygen, which
is not involved in oxidation of dyed goods, needlessly consumes
a sizable amount of hydrogen peroxide or precursors liberating
it, both of which are expensive products. Moreover, it has
been found that the various stains in cloth and the like
greatly accelerates decomposition of hydrogen peroxide into
gaseous oxygen during washing at ordinary temperature.
In general, washing cloth, either in a machine, by
hand, or in boiler or tubs, is accomplished by dissolving
a bleaching or detergent composition (containing perborate,
for example) in cold or lukewarm water, adding to the solution
thus formed the soiled cloth (from which some of the s~rains
have often already been removed by soaking or previous washing)
and heating, often just to boiling.
However, it was found that, by a phenomenon similar
to that previously mentioned, all or part of the perborate
was decomposed during heating and more specifically during
62301-1370
the temperature rise, i.e. that all or part of the perborate
was decomposed before the really effective temperature is
reached.
It is believed that this rapid decomposition of
hydrogen peroxide r perborate, or other precursors of hydrogen
peroxide into gaseous oxygen at low temperature is due to the
extremely powerful catalytic action of certain enzymes which
are always present in stains, which are present on materials to
be washed, and particularly on soiled cloth, such as linens,
these enzymes coming from secretions or being of bacterial
origin. Hydroperoxides are an especially active group of
enzymes in this respect, particularly catalase, which is well
known as a highly effective catalyst for decomposing hydrogen
peroxide to gaseous oxygen. Such enzyme substances, whether
termed "redox" or otherwise are nevertheless uniformly
characterized in exhibiting a pronounced tendency to induce
decomposition of peroxide bleaching agent, the decomposition
products evolved thereby comprising ineffective bleaching
species.
In order to take advantage of the low temperature
effective detergents and low temperature washing cycles now
commonly used for temperature sensitive fabrics, the peroxygen
compound is preferably used in admixture with an activator
therefor. Suitable activators which can lower the effective
operating temperature of the peroxide bleaching agent to about
40C (104F) or less, are disclosed, for example, in U. S.
Patent 4,264,466 or in column of U. S. Patent 4,430,244.
Polyacylated compounds are preferred activators; among these,
compounds such as tetraacetyl ethylene diamine ("TAED") and
pentaacetyl glucose are particularly preferred. Other useful
activators include for instance acetylsalicyclic acid and
- 30 -
X
-~- 62301-1370
~O~g
its salts, ethylidene benzoate acetate (EBA) and its salts,
ethylidene carboxylate acetate and its salts, alkyl and alkenyl
succinic anhydride, tetraacetylglycouril (TAGU), and the
derivatives of these. See also U. S. Patents 4,111,826,
4,422,950 and 3,661,789 for other classes of activators useful
herein.
The bleach activator usually interacts with the
peroxygen compound to form a peroxyacid bleaching agent in the
wash water. It is preferred to include a sequestering agent of
high complexing power to inhibit any undesired reaction between
such peroxyacid and hydrogen peroxide in the wash solution in
the presence of metal ions. Preferred sequestering agents are
able to form a complex with Cu2+ ions, such that the stability
constant (pK) of the complexation is equal to or greater than
6, at 25C, in water, of an ionic strength of 0.1 mole/liter,
pK being conventionally defined by the formula: pR=-log K where
K represents the equilibrium constant. Thus, for example, the
pK values for complexation of copper ion with NTA and EDTA at
the stated conditions are 12.7 and 18.8, respectively. Suitable
sequestering agents include for example, in addition to those
mentioned above, diethylene triamine pentaacetic acid (DETPA);
diethylene triamine pentamethylene phosphonic acid (DTPMP);
and ethylene diamine tetramethylene phosphonic acid (EDITEMPA).
However, even in the presence of the bleach
activators, and even at temperatures as low as room temperature,
decomposition of the persalt will occur in the presence of the
stained cloth since the rate of reaction between the bleaching
agent and the activator is slower than the rate of decomposition
of hydrogen peroxide by catalase.
In order to avoid loss of bleaching agent resulting
from enzyme-induced decomposition, the compositions of this
~ 6~9 62301-1370
invention will preferably additionally include an effective
amount of a compound capable of inhibiting this enzyme-induced
decomposition of this invention will preferably additionally
include an effective amount of a compound capable of inhibiting
this enzyme-induced decomposition of bleaching agent. Suitable
inhibitor compounds are disclosed in U. S. Patent 3,606,990.
Of special interest and importance as the inhibitor
compound is hydroxylamine sulfate and other water-soluble
hydroxylamine salts, including, for example, hydrochloride,
hydrobromide, etc. It has now been found that the hydroxylamine
salts, especially the sulfate, are effective to inhibit the
deletorious effect of catalase even when present in the
composition in very limited amounts, for example, less than
0.5%, such as 0.01 to 0.4%, preferably 0.04 to 0.2%, and
especially preferably about 0.1%, based on the weight of the
total composition.
Furthermore, the hydroxylamine inhibitor is highly
; stable in the composition: less than 20% loss after aging for
2 months at 43C. The hydroxylamine salts are very rapidly
solubilized in water and can accordingly react with catalase
before dissolution of the perborate or other peroxide bleaching
agent. Another advantage of the hydroxylamine salts is that
they are rapidly destroyed in the washing liquor, and
consequently, no nitrosamine derivatives have been detected.
Where the bleaching system is activated by one of
the bleach activators, e.g. TAED, the activator is utilized
more effectively and, therefore, suitable ratios of persalt
bleaching agent/bleach activator can be maintained at levels
much closer to the stoichiometric equivalent weights or with
only small molar excess of the bleaching agent.
- 32 -
--
The composition may also contain an inorganic insoluble
thickening agent or dispersant of very high surface area
such as finely divided silica of extremely ~ine particle
size (e.g. of 5-100 millimicrons diameters such as sold under
the name Aerosil) or the other highly voluminous inorganic
carrier materials disclosed in U.S. Patent 3,630,929, in
proportions of 0.1-10%, e.g. 1 to 5%. It is pre~erable,
however, that compositions which form peroxyacids in the
wash bath (e.g. compositions containing peroxygen compound
and activator therefor) be substantially free of such compounds
and of other silicates; it has been found, for instance,
that silica and silicates promote the undesired decomposition
of the peroxyacid.
In a preferred form of the invention, the mixture
of liquid nonionic surfactant and solid ingredients is subjected
to an attrition type of mill in which the particle sizes
of the solid ingredients are reduced to less than about 10 micron .
e.g. to an average particle size of 2 to 10 microns or even
lower ~e.g. 1 micron). Compositions whose dispersed particles
are of such small size have improved stability against separation
or settling on storage.
In the grinding operation, it is preferred that the
proportion of solid ingredients be high enough (e.g. at least
about 40% such as about 50%) that the solid particles are
in contact with each other and are not substantially shielded
from one another by the nonionic surfactant liquid. Mills
which employ grinding balls (ball mills) or similar mobile
grinding elements have given very good results. Thus, one
~ay Ise a laboratory batch attritor having 8 mm diameter
steatite grinding balls. For larger scale work a continuously
~ 9 _~ I
operating mill in which there are I mm or 1.5 mm diameter
grinding balls working in a very small gap between a stator
and a rotor operating at a relatively high speed (e.g. a
CoBall mill) may be employed; ~hen using such a mill, it
is desirable to pass the blend of nonionic surfactant and
solids first through a mill wh:ich does not effect such fine
grinding (e.g. a colloid mill) to reduce the particle size
to less than 100 microns (e.g., to about 40 microns) prior
to the step of grinding to an average particle diameter below
about 10 microns in the continuous ball mill.
In the preferred heavy duty liquid detergent compositions
of the invention, typical proportions (based on the total
composition, unless otherwise specified) of the ingredients
are as follows:
Suspended detergent builder, within the range of
about 10 to 60% such as about 20 to 50%, e.g. about 25 to
40%;
Liquid phase comprising-nonionic surfactant and dissolved
amphiphilic viscosity-controlling and gel-inhibiting compound,
within the range of about 30 to 70%, such as about 40 to
60%; this phase may also include minor amounts of a diluent
such as a glycol, e.g. polyethylene glycol (e.g., "PEG 400"),
hexylene glycol, etc. such as up to 10%, preferably up to
5%, for example, 0.5 to 2%. The weight ratio of nonionic
surfactant to amphiphilic compound is in the range of from
about 100:1 to 1:1, preferably from about 50:1 to about 2:1,
especiae), hexylrably, from about 25:1 to about 3:1.
Polyether carboxylic acid gel-inhibiting compound,
in an amount to supply in the range of about 0.5 to 10 parts
(e.g. about 1 to 6 parts, such as about 2 to 5 parts) of
-COOH (M.W. 45) per 100 parts of blend of such acid compound
--- ~ 9~9
I
and nonionic surfactant. Typically, the amount of the polyether
carboxylic acid compound is in the range of about 0.01 to
1 part per part of nonionic surfactant, such as about 0.~5
to 0.6 part, e.g. about 0.2 to 0.5 part;
Acidic organic phosphoric acid compound, as anti-settling
agent: up to 5%, for example, in the range of 0.01 to 5%,
such as about 0.05 to 2%, e.g. about 0.l to 1%.
Suitable ranges of other optional detergent additives
are: enzymes - 0 to 2%, especially 0.7 to 1.3%; corrosion
inhibitors - about 0 to 40%, and prefe~rably 5 to 30%; anti-foam
agents and suds-suppressors - 0 to 15%, preferably 0 to 5%,
for example 0.1 to 3%; thickening agent and dispersants -
0 to 15%, for example O.l to 10%, preferably 1 to 5%; soil
suspending or anti-redeposition agents and anti-yellowing
agents - 0 to 10%, preferably 0.5 to 5%; colorants, perfumes,
brighteners and bluing agents total weight 0% to about 2~/~
and preferably 0% to about 1%; pH modifiers and pH buffers
- O to 5%~ preferably 0 to 2%; bleaching agent - ~/0 to about
40% and preferably 0% to about 25%, for example 2 to 20%;
inhibitor compound for inhibiting enzyme-induced decomposi~ion
of bleaching agent - up to about 0.5%, preferably 0.01 to
0.4 or 0.5/" more preferably 0.04 to 0.2%; bleach stabilizers
and bleach activators 0 to about 15%, preferably 0 to 10%,
for example, 0.1 to 8%; sequestering agent of high comple~ing
power, in the range of up to about 5%, preferably about 1/4
to 3%, such as about 1/2 to 2%. In the selections of the
adjuvants, they will be chosen to be compatible with the
main constituents of the detergent composition.
All proportions and percentages are by weight unless
orher~ise indicated.
It is understood that the foregoing detailed description
is given merely by way of illustration and that variations
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6;~9
62301-1370
may be made therein without departing from the spirit of the
invention.
In order to demonstrate the effec-ts of the viscosity
control and gel-inhibiting agents, various compositions were
prepared using the above described Surfactant T8 (C13, E08) (50/
50 weight mixture of Surfactant T7 and Surfactant T9) as the non-
aqueous liquid nonionic surface active cleaning agent. Formula-
tions containing 5%, 10%, 15%, or 20% of amphiphilic additlve
were prepared and were tested at 5C, 10C, 15C, 20C and 25C
for different dilutions with water, i.e. 100%, 83%, 67%, 50% and
33% total nonionic Surfactant T8 plus additive concentrations,
i.e. after dilution in water. The additives tested were Alfonic
610-60 (C8-E04.4), ethylene glycol monoethyl ether (C2-E01), and
diethylene glycol monobutyl ether (C4-E02). The results of vis-
cosity behavior on dilution of each tested composition at each
temperature were obtained.
For Alfonic 610-60, 5% addition was sufficient to
inhibit gelation at 25C; however, in the plot of viscosity vs.
concentration of nonionic a sharp viscosity maximum was observed
at about 67% concentration and a shoulder was observed at about
55% to 35% nonionic concentration. At 5C, 15% addition was
necessary to avoid gel formation. The viscosity decreased to a
minimum at a nonionic concentration of about 83% at all levels
of additive addition at 5C whereas at the higher temperatures,
viscosity minimums were observed for the non-diluted formulations,
i.e. 100% nonionic concentrations. At each temperature and for
each tested concentration of additive (except at 20% additive at
25C) a relatively sharp peak is seen in the viscosity existing
between 75 to 50% concentration of nonionic (i.e. 25 to 50%
dilution).
For ethylene glycol monoethyl ether 5% additive was
capable of inhibiting gel formation even at 5C. However,
- 36 -
,~"
--~
sharp peaks and/or maxima of viscosity were again observed
at each temperature and additive concentration, although
the effects were not as pronounced as for Alfonic 610-60,
and for some applications the maximum viscosities, especially
at higher additive concentrations and/or higher temperatures
could be acceptable for commercial use.
On the other hand, there were no sharp peaks in viscosity
observed for diethylene glycol monobutyl ether at any temperature
down to 5C at the 20% add;tive level. Even at the lower
additive levels the viscosity peaks and the viscosity values
at substantially all dilutions (concentrations of nonionics)
were lower than for either the C8-EO4.4 or C2-EOl additive.
The following table is representative of the results
which were obtained for the different additive concentrations,
dilutions, and temperatures, but are given for 20% additive
and 5C temperature:
Compositions Viscosity Pour Point
at 5C (Pa-sec) (C)
No Water 50% 7~7ater
Surfactant T8 only 1.140 1.240 5
80% Surfactant T8~20%A 0.086 0.401 -10
80% Surfactant T8+20%B 0.195 0.218 -2
80% Surfactant T8+20%C 0.690 0.936 3
A = ethylene glycol monoethyl ether
B = diethylene glycol monobutyl ether
C = Alfonic 610-60 (C8-4.4EO)
Note: 1 Pa sec = 10 poises (e.g. 0.218 Pa-sec = 218 centipoises)
-37-
- ~ 62301-1370
Example _
A heavy duty built non-aqueous liquid nonionic
cleaning composition having the following formula is prepared:
Ingredient Weight~
. _
Surfactant T7 17.0
Surfactant T8 1 17.0
Dobanol 91-5 Acid 5.0
Diethylene glycol monobutyl ether 10.0
Dequest 2066 ' 1.0
TPP NW (sodium tripolyphosphate) 29.0925
Sokolan CP5 3 (calcium sequestering agent) 4.0
Perborate H2O (sodium perborate morlohydrate) 9.0
T.A.E.D. (tetraacetylethylene diamine) 4.5
Emphiphos 5632 4 0.3
Stilbene 4 (optical brightener) 0.5
Esperase (proteolytic enzyme) 1.0
Duet 787 5 0.6
Relatin DM 4050 6 (anti-redeposition agent) 1.0
Blue Foulan Sandolane (dye) 0.0075
1) The esterification product of Dobanol 91-5
la Cg-Cll fatty alcohol ethoxylated with 5 moles ethylene oxide)
with succinic anhydride - the half-ester.
2) Diethylene triamine pentamethylene phosphoric
acid, sodium salt.
3) A copolymer of about equal moles of methacrylic
acid and maleic anhydride, completely neutralized to form the
sodium salt thereof.
4) Partial ester of phosphoric acid and a C16 to C18
alkanol about 1/3 monoester and 2/3 diester.
5) Fragrance.
6) Mixture of sodium carboxylmethyl cellulose and
hydroxymethylcellulose.
This composition is a stable, free-flowing, built,
non-gelling, liquid nonionic cleaning compositions in which
the polyphosphate builder is stably suspended in the liquid
nonionic surfactant phase.
- 38 -
X
-~ ~ 9 -~
Example 2
In the same manner as in Example 1, the following heavy duty
built non-aqueous liquid nonionic cleaning composition containing
an enzyme inhibitor is prepared:
In~redient Wei~ht%
Plurafac RA 30 37.5
Diethyleneglycol monobutyl ether 10.0
Octenylsuccinic anhydride 2.0
TPP NW 28.4
Sokolan CP5 4.0
Dequest 2066 1.0
Perborate H2O 9.0
TAED 4-~
Hydroxylamine sulfate 0.1
Emphiphos 5632 0.3
ATS-X (optical brightener) 0.2
Esperase 1.0
Perf~me 0.S
Rela~in DM 4050 1.0
TiO2 0.4
This composition has the same advantageous features
as the composition of Exar.lple 1 and, in addition, provides
improved bleaching performance.
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