Note: Descriptions are shown in the official language in which they were submitted.
1220742
This invention relates to stable, built, enzyme-contain-
ing liquid detergent compositions suitable for laundry or pre-
soak formulations. More particularly, the inVention relates to
aqueous enzyme-containing liquid detergent compositions which
contain a non-phosphate detergent builder and Which are character-
ized by being physically stable, clear, single-phase homogeneous
liquid compositions.
The formulation of stabilized enzyme-containing liquid
detergent compositions has been the focus of much attention in
the prior art. The desirability of incorporating enzymes into
detergent compositions is primarily due to the effectiveness of
proteolytic and amylolytic enzymes in decomposing proteinaceous
and starchy materials found on soiled fabrics, thereby facilitat-
ing the removal of stains, such as, gravy stains, blood stains,
chocolate stains and the like during laundering. However,
enzymatic materials suitable for laundry compositions, particu-
larly proteolytic enzymes, are relatively expensive. Indeed,
they generally are the most expensive ingredient in a typical
commercial liquid detergent composition, even when present in
relatively minor amounts. Moreover, enzymes are known to be
unstable in aqueous compositions. It is for this reason that an
excess of enzymes is generally required in liquid detergent
formulations to compensate for the expected loss of enzyme
activity during prolonged periods of storage. Accordingly,
the prior art is replete with suggestions for stabilizing enzyme-
containing liquid detergent compositions, and in particular
unbuilt liquid compositions by the use of various materials which
are incorporated into the composition and serve as enzyme
stabilizers.
In the case of liquid detergent compositions containing
a builder, the problem of enzyme instability is particularly
acute. Primarily this is because detergent builders have a
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lZ20742
destabilizing effect on enzymes, even in compositions containing
enzyme stabilizers which are otherwise effective in unbuilt
formulations. Moreover, the incorporation of a builder into
a liquid detergent composition poses an additional problem,
namely, the ability to form a stable single-phase solution, the
solubility of sodium tripolyphosphate, for example, being rela-
tively limited in aqueous compositions, and especially in the
presence of
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12;ï~0742
anionic and nonionic detergents. Thus, for example, in U.K. Patent ~plica-
tion G.B. 2,079,305, published January 20, 1982, there is disclosed an aqueous
built enzyme-containing liquid detergent composition which is stabilized by a
mixture of a polyol and boric acid. The compositions described in the examples,
however, rather than being stable, clear, single-phase solutions, are instead
turbid suspensions which are susceptible to product separation over prolonged
periods of storage. Consequently, the problems of enzyme stability and physical
product stability remain as problems yet to be overcome in formulating a com-
mercially acceptable built enzyme-containing liquid detergent composition.
lZZ07~Z
Summary of the Invention
The present invention provides a stabilized aqueous,
built, clear, single-phase, enzyme-containing liquid detergent
composition comprising:
(a) from about 3 to 10%, by weight, of a surface
active nonionic detergent compound;
(b) from about 3 to 15%, by weight, of a surface active
amphoteric detergent compound;
(c) from about 5 to 25%, by weight, of a non phosphate
detergent builder salt;
(d) an effective amount of an enzyme or enzyme mix-
ture selected from the group consisting of alka-
line protease enzymes and alpha-amylase enzymes;
(e) from about 3 to 15%, by weight, of an enzyme
stabilizing system consisting essentially of
(i) glycerine and (ii) a boron compound selected
from the group consisting of boric acid, boric
oxide and alkali metal borates capable of reacting
with said glycerin; and
(f) from about 30 to 85%, by weight, water.
In accordance with the process of the invention,
laundering of stained and/or soiled materials is effected by
contacting such materials with an aqueous solution of the above-
defined liquid detergent composition. Unlike the built, enzyme-
containing detergent compositions known in the art, the compos-
itions of the present invention are characteristically clear,
single-phase homogeneous solutions which are physically stable
over prolonged periods of storage and over a wide range of
temperature. They are preferably substantially free of phosphate
builder salts.
The use of a mixture of nonionic and amphoteric surface
active detergent compounds in accordance with the invention
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enables such sur~actants and the non-phosphate builder to be
sufficiently solubilized in an aqueous eomposition so as to form
a homogeneous single-phase solution. The nonionic detergent
compound may constitute from about 3-10%, preferably from about
4-8%, by weight, of the detergent eomposition and the amphoterie
detergent compound will generally vary from about 3-15%, prefer-
ably from about 4-10%, by weight, of sueh eomposition.
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~Z20742
The relative amounts of each of the aforementioned detergents is generally
determined by the amount of builder salt employed. For builder concentra-
tions of from about 5 to 15%, by weight of the detergent composition, the
amphoteric and nonionic detergents are typically each present in an amount
from about 4 to 7%, by weight, the relative ratio of amphoteric to nonionic
detergent being generally about 1. For builder concentrations within the
range of about 15 to 25%, by weight, the amphoteric detergent is typically
present from about 6 to 10%, by weight~ and the relative ratio of amphoteric
to nonionic detergent is preferably above 1, a ratio of from about 1.2 to
about 1.6 being especially desirable, the higher ratios generally corres-
ponding to higher concentrations of builder salt.
DETAILED DESCRIPTION OF THE INVENTION
-
The enzyme stabilizing system of the invention is a mixture of
glycerine and a boron compound selected from among boric acid, boric oxide
and an alkali metal borate capable of reacting with glycerine. The weight
of the stabilizing system in the present built detergent compositions is
from about 3 to 15%, preferably 4 to 10%, by weight. Mixtures of glycerine
and borax are especially useful for providing enzyme stability, the weight
ratio of glycerine to borax in such stabilizing mixtures being generally
from about 1.2 to 3, a ratio of from about 1.5 to 2.5 being preferred.
Accordingly, the preferred amount of glycerine in the composition is from
about 3 to 7%, and the preferred amount of borax is from about 1 to 4%,
based on the weight of the composition.
The alkaline proteolytic enzymes suitable for the present composi-
tions include the various commercial liquid enzyme preparations which have
been adapted for use in detergent compositions, enzyme preparations in pow-
dered form being also useful although, as a general rule, less convenient
for incorporation into the built liquid detergent compositions. Thus, suit-
able liquid enzyme preparations include "Alcalase"* and "Esperase"* sold by
Novo Industries, Copenhagen, Denmark, and "Maxatase"* and "AZ-Protease"*
*Trade Mark - 5 -
~2Z0742
sold by Gist-Brocades, Delft, The Netherlands.
Among the suitable~-amylase liquid enzyme preparations are those
sold by Novo Industries and Gist-Brocades under the names "Termamyl"* and
"Maxamyl"*, respectively.
"Esperase" is particularly preferred for the present compositions
because of its optimized activity at the higher pH values corresponding to
the built detergent compositions.
The synthetic nonionic and amphoteric detergents employed in the
practice of the invention may be any of a wide variety of such compounds
which are well known and are described at length in the text Surface Active
Agents, Vol. II, by Schwartz, Perry and Berch, published in 1958 by Inter-
science Publishers.
The nonionic detergents are usually poly-lower alkoxylated lipo-
philes wherein the desired hydrophile-lipophile balance is obtained from
addition of a hydrophilepoly-lower alkoxy group to a lipophilic moiety. For
the present compositions the nonionic detergent employed is preferably a
poly-lower alkoxylated higher alkanol wherein the alkanol is of 10 to 18
carbon atoms and wherein the number of moles of lower alkylene oxide (of 2
or 3 carbon atoms) is from 3 to 12. Of such materials it is preferred to
employ those wherein the higher alkanol is a higher fatty alcohol of 11 or
12 to 15 carbon atoms and which contain from 5 to 8 or 5 to 9 lower alkoxy
groups per mole. Preferably, the lower alkoxy is ethoxy but in some
instances it may be desirably mixed with propoxy, the latter, if present,
usually being a minor (less than 50%) constituent. Exemplary of such com-
pounds are those wherein ~he alkanol is of 12 to 15 carbon atoms and which
contain about 7 ethylene oxide groups per mole, 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
*Trade Mark - 6 -
12Z~74Z
the higher fatty alcohol is 12 to 13 and the number of ethylene oxide groups
per mole 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 Corporation. The former is a mixed ethoxylation product of an 11
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122Q74Z
to 15 carbon atom linear secondary alkanol with seven moles of
ethylene oxide and the latter is a similar product but with
nine moles of ethylene oxide being reacted.
Also useful in the present compositions are higher mol-
ecular weight nonion~ics, such as Neodol 45-11, which are similar
ethylene oxide condensation 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 mole being about 11.
Such products are also made by Shell Chemical Company. Other
useful nonionics are represented by Plurafac* B-26 (BASF
Chemical Company), the reaction product of a higher linear
alcohol and a mixture of ethylene and propylene oxides.
In the preferred poly-lower alkoxylated higher
alkanols, the best balance of hydrophilic and lipophilic moieties
are obtained when the number of lower alkoxides are from about 40
to 100% of the number of carbon atoms in the higher alcohol,
preferably 40 to 60~ thereof. The nonionic detergent is
preferably comprised of at least 50% of the preferred ethoxv-
lated alkanols. Higher molecular weight alkanols and various
other nomally solid nonionic detergent compounds and surfactants
may contribute to gelation of the liquid detergent composition
and consequently, are normally 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 deter-
gents, the alkyl groups present therein are preferably linear
although a minor degree of slight 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 with
the proviso that such branched alkyl is no more than three carbons
in length. Normally the proportion of carbon atoms in such a
branched configuration will be minor, rarely exceeding 20% of
*T.~. -7-
~22074Z
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
optimum combination of detergency, biodegrada~ility and non-gel-
ling characteristics, medial or secondary joinder to the
ethylene oxide in the chain may occur. In such instance, it is
usually in only a minor proportion of such alkyls, generally less
than 20% but as is in the case of the aforementioned Tergitols,
may be greater. Also, when propylene oxide is present in the
lower alkylene oxide chain, it will usually be less than 20
thereof and preferably less than 10% thereof.
Amphoteric detergents include the higher fatty carboxy-
lates, phosphates, sulfates or sulfonates which contain a cationic
substituent such as an amino group, which may be quaternized,
e.g., with a lower alkyl group, or chain extended at the amino
group by condensation with a lower alkylene oxide, e.g., ethylene
oxide. Examples of suitable amphoteric detergents include:
alkyl beta-amino dipropionates, RN~C2H4COOM)2; alkyl beta-amino
propionates, RN(H) C2H4COOM; and long chain imidazole derivatives
having the ~eneral formula:
f H~
INI f H2
R- C /N- CH2CH2OCH2COOM
OH H2COOM
wherein in each of the above formulae R is an acyclic hydrophobic
group containing from about 8 to 18 carbon atoms and M is a
cation to neutralize the charge of the anion.
An anionic detergent may optionally also be employed
in minor amounts to supplement the nonionic and amphoteric
detergent compounds in the present liquid detergent compositions.
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~2Z0742
Generally, the amount of anionic detergent will be below about
5%, by weight, and preferably, below about 3%, by weight, of the
total composition because of the limited solubility o-E such
detergents in the built liquid detergent compositions. Alkyl
benzene sulfonate salts wherein the alkyl group contains 10 to
18 carbon atoms are particularly limited in solubility in the
present compositions, and hence it is preferred that the present
compositions be substantially free of such compounds to avoid the
possibility of product separation.
The preferred anionic detergents for use herein are
sulfated ethoxylated higher fatty alcohols o the formula
RO(C2H4O)mSO3M, wherein R is a fatty alkyl of from 10 to 18 or
20 carbon atoms, m is from 2 to 6 or 8 (preferably having a value
from about 1/5 to 1/2 the number of carbon atoms in R) and M is
a solubilizing salt-forming cation, such as an alkali metal,
ammonium, lower alkyl-amino or lower alkanolamino, or a higher
alkyl benzene sulfonate wherein the higher alkyl is of 10 to 15
carbon atoms.
Ethylene oxide is the preferred lower alkylene oxide
of the anionic alkoxylate detergent, and the proportion thereof
in the polyethoxylated higher alkanol sulfate is preferably 2
to 5 moles of ethylene oxide groups present per mole of anionic
detergent, with three moles being most preferred, especially
when the higher alkanol is of 11 or 12 to 15 carbon atoms. To
maintain the desired hydrophile-lipophile balance, when the
carbon atom content of the alkyl chain is in the lower portion of
the 10 to 18 carbon atom range, the ethylene oxide content of the
detergent may be reduced to about two moles per mole whereas when
the higher alkanol is of 16 to 18 carbon atoms, in the higher
part of the range, the number of et~ylene oxide groups may be
increased to 4 or 5 and in some cases to as high as 8 or 9.
Similarly, the salt-orming cation may be altered to obtained the
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~220742
best solubility. It may be any suitably solubilizing metal or
radical but will most frequently be alkali metal, e.g., sodium,
or ammonium. If lower alkylamine or alkanolamine groups are
utilized the alkyls and alkanols will usually contain from 1 to
4 carbon atoms and the amines and alkanolamines may be mono-,
di- and tri-substituted, as in monoethanolamine, diisopropanol-
amine and trimethylamine. A pre~erred polyethoxylated alcohol
sulfate detergent is available from Shell Chemical Company and
is marketed as ~eodol 25-3S*.
The non-phosphate detergent builder salts are employed
in the present compositions in amounts generally of from about
5 tG 25%, and preferably from about 10 to 20%, by weight.
Specific examples of non-phosphorous water-soluble inorganic
*T.M.
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~220742
builders include water-soluble inorganic carbonate, bicarboante and silicate
salts. The alkali metal, for example, sodium and potassium, carbonates,
bicarbonates and silicates are particularly useful herein.
Water-soluble organic builders are also useful and include the
alkali metal, ammonium and substituted ammonium polyacetates, carboxylates,
polycarboxlyates and polyhydroxysulfonates. Specific examples of polyace-
tate and polycarboxylate builders include sodium, potassium lithium, ammoni-
um and substituted ammonium salts of ethylene diaminetetracetic acid,
nitrilotriacetic acid, benzene polycarboxylic (i.e. penta- and tetra-)
acids, carboxymethoxysuccinic acid and citric acid.
The percentage of water, the main solvent in the present composi-
tions, will usually be from about 30 to 85%, preferably 45 to 75% and most
preferably from about 60 to 70%, by weight, of the liquid composition.
The optical fluorescent brighteners or whiteners employed in the
liquid detergent compositions are important constituents of modern detergent
compositions which give washed laundry and materials a bright appearance so
that the laundry is not only clean but also appears clean. Although it is
possible to utilize a single brightener for a specific intended purpose-in
the present liquid detergent compositions it is generally desirable to
employ mixtures of brighteners which will have good brightening effects on
cotton, nylons, polyesters and blends of such materials and which are also
bleach stable. A good description of such types of optical brighteners is
given in the article "The Requirements of Present Day Detergent Fluorescent
Whitening Agents" by A.E. Siegrist, J. Am. Oil Chemists Soc., January 1978
(Vol. 55). That article and U.S. Patent 3,812,041, issued May 21, 1974,
contain detailed descriptions of a wide variety of suitable optical bright-
eners.
Among the brighteners that are useful in the present liquid deter-
gent compositions are : Calcofluor*5BM (American Cyanamid): Tinopal*LPW
(Ciba); SOF A-2001 (Ciba); CDW (Hilton-Davis); Phorwite*RKH, Phorwite BBH
*Trade Mark - 10 -
A
lZZ07~2
and Phorwite BHC (Verona); CSL, powder, acid (American Cyanamid);
FB 766 (Verona); Blancophor*PD (GAF); UNPA (Geigy); Tinopal RBS
200 (Geigy).
Adjuvants may be present in the liquid detergent com-
positions to provide additional properties, either functional or
aesthetic. Included among the useful adjuvants are soil suspend-
ing or antiredoposition agents, such as polyvinyl alcohol, sodium
carboxymethyl cellulose, hydroxypropylmethyl cellulose; thicken-
ers, e.g., gums, alginates, agar agar; foam improvers, e.g.,
lauric myristic diethanolamide; foam destroyers, e.g., silicones;bactericides, e.g. tribromosalicylanilide, hexachlorophene;
dyes; pigments (water dispersible); preservatives; ultraviolet
absorbers; fabric softeners; opacifying agents, e.g., polystyrene
suspensions; and perfumes. Of course, such materials will be
selected based on the properties desired in the finished product,
their compatibility with the other constitutents, and their
solubility in the liquid composition.
The pr~sent liquid compositions are efficient and easy
to use. Compared to heavy duty laundry detergent powders, much
smaller volumes of the present liquids are employed to obtain
comparable cleaning of soiled laundry. For example, using a
typical preferred formulation of this invention, only about 132
grams or 1/2 cup of liquid is needed for a full tub of wash in
a top-loading automatic washing machine in which the water volume
is 15 to 18 gallons (55 to 75 liters); and even less is needed
for front-loading machines. Thus, the concentration of the
liquid detergent composition in the wash water is on the order
of about 0.2%. Usually, the proportion of the liquid composition
in the wash solution will range from about 0.05 to 0.3%,
preferably from 0.15 to 0.25%. The proportions of the various
constituents of the liquid composition may vary accordingly.
Equivalent results can be obtained by using greater proportions
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*T.M.
1220742
of a more dilute formulation but the greater quantity needed
will require additional packaging and will generally be less
convenient for consumer use.
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~2Z074Z
EXA~IPLE 1
~ .ymc-coll~Dinil~ I)uil~ Ui(l (l~ r~ (ollll)o.~ ; A-l` w~
as set forth below in Table 1. The percentages sh~n indicate weigh~ percent.
Table 1
~ 13
Ethoxylated C12-C15 5-5% 5-5% 5-5% 5 5% 5-5% 5 5'
primary alcohol
(7 moles E0/mole alcohol)
Varion CADG( ) 21 21 21 21 21 21
Brightener 0.2 0.2 ~.~ 0.2 ~.' ().
Sodium Nitriliotriacetate 15 15 15 15 15 15
PBB(2)
Perfume 0.3 0.3 0.3 0.3 0.3 0.3
Proteolytic enzyme(3)
glycerine --- 5 5 5 5 ---
Borax --- 1 2 3 --- 3
H20 -------------------bal.lnce---------------_--
Percent active enzyme after 12 62 73 76 21 ~ 2
6 days at 110F
(1) A 32% aqueous solution of coco-amido betaine sold by Sherex Chemica1 Company.
(2) Polar Brilliant Blue - a 1% active dye solution.
(3) "Esperase" sold by Novo Industries containing 5% enzyme, 75% propylene
glycol, and balance H20 having an activity of 8.0 ~NPU/gm. (~ilo Novo Protease
units/gm).
~ZZ074Z
The enzyme activities of compositions A-l wcre testcd after 6 days s~oragc
at 11~~, the percenL activity relative to the initial value being indicaled in
Table 1 A, E and E wcre the only composi-ions whi~h did noL con-aill all ell~yllle
stabilizing system in accordance with the invention, and manifested a near total
loss of enzyme activity after 6 days Compositions B, C and D reflect the
marked improvement of enzyme stability attendant to the inclusion of glycerine
and borax in the detergent composition
Compositions A through F were all clear, single-phase, homogeneous solu-
tions which maintained their physical stability and clari~y af~cr 6 mon~ls of
storage at both room temperature and at 110F
~220742
EXAI'`II'LE 2
ulated essentially similar to composi~:ions A-F ~xcept that sodium ci~rat( wa~
used as the builder salt instead of sodium NTA. The compositions are shown
below in Table 2.
Table 2
Ethoxylated C12-C15 primary alcohol (;
(7 moles ~O/mole alcohol) 5.5% 5.5i~
Varion CADG(l) 21 21
Brightener 0.2 ().2
Sodium citrate 13 l3
PBB( )
Perfurne ~.3 0.3
Proteolytic enzyme(3)
glycerine
Borax . --- 3
H20 ---------balance---------
Percent active enzyme after 6 days at 110~F 26 95
-
(1) A 32% aqueous solution of coco-amido betaine sold by Sherex Chemical Company.
(2) Polar Brilliant Blue - a 1% active dye solution.
(3) "Esperase" sold by Novo Industries containing 5% enzyme, 75% propylene
glycol, ancl balance 1l20 'having an activ.i~y o~ ~,.0 ~NPU/gm. (~ilo No~c~ Plo~.e~
units/gm).
~;Z20742
Composition H in accordance with the invention manifested an enzyme
activity after 6 days of 95% as compared to composition (, which containc~(l
no enzyme stabilizing system and suffered almost a 3/4 loss of enzyme ac~ivi~y.
'I'l~e composi~ion~ were clear single~ use solu~iolls whicll remui~ d ~ icully
stable after 6 months of storage at both room temperature and 110F.
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