Built single phase liquid anionic detergent compositions containing stabilized enzymes

A stabilized built single-phase enzyme-containing liquid detergent composition is provided comprising: PA0 (a) from about 8 to 20%, by weight, of one or more surface active anionic detergent compounds; PA0 (b) from about 5 to 25%, by weight, of a water-soluble non-phosphate detergent builder salt; PA0 (c) an effective amount of an enzyme or enzyme mixture selected from the group consisting of alkaline protease enzymes and alpha-amylase enzymes; PA0 (d) an enzyme stabilizing system containing, based on the weight of the detergent composition, (i) from about 12 to 25% of propylene glycol and (ii) from about 1 to 5% of a boron compound selected from the group consisting of boric acid, boric oxide and alkali metal borates; and PA0 (e) from about 25 to 75%, by weight, water.

This invention relates to stable, built, enzyme-containing 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 characterized 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 facilitating the removal of stains, such as, gravy 
stains, blood stains, chocolate stains and the like during laundering. 
However, enzymatic materials suitable for laundry compositions, 
particularly 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 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 relatively limited in aqueous 
compositions, and especially in the presence of anionic and nonionic 
detergents. Thus, for example, in U.K. Patent Application G.B. No. 
2,079,305, published Jan. 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 commercially acceptable built 
enzyme-containing liquid detergent composition. 
SUMMARY OF THE INVENTION 
The present invention provides a stabilized aqueous, built, clear, 
single-phase, enzyme-containing liquid detergent composition comprising: 
(a) from about 8 to 20%, by weight, of one or more surface active anionic 
detergent compounds; 
(b) from about 5 to 25%, by weight, of a water-soluble non-phosphate 
detergent builder salt; 
(c) an effective amount of an enzyme or enzyme mixture selected from the 
group consisting of alkaline protease enzymes and alpha-amylase enzymes; 
(d) an enzyme stabilizing system containing based on the weight of the 
detergent composition (i) from about 12 to 25% of propylene glycol and 
(ii) from about 1 to 5% of a boron compound selected from the group 
consisting of boric acid, boric oxide and alkali metal borates; and 
(e) from about 25 to 75%, 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 
compositions 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. To 
avoid product separation, the present compositions are preferably 
substantially free of a phosphate builder salt. 
Unlike the enzyme-containing built liquid anionic detergent compositions 
disclosed in the art, the anionic surfactant in the present compositions 
is solubilized in the presence of a builder salt. Moreover, the present 
enzyme-containing compositions are characterized by the presence of an 
enzyme-stabilizing system which in addition to providing long-term 
stability to the enzyme over a wide range of temperatures, serves to 
enhance the solubility of the anionic surfactant and the non-phosphate 
builder in the aqueous composition allowing a physically stable 
single-phase solution to be formed for the particular range of 
compositions indicated. 
DETAILED DESCRIPTION OF THE INVENTION 
The enzyme stabilizing system of the invention is a mixture of propylene 
glycol and a boron compound selected from among boric acid, boric oxide 
and alkali metal borate capable of reacting with propylene glycol. The 
amount of propylene glycol is from about 12 to 25%, preferably from about 
15 to 20%, by weight, and the amount of the boron compound may vary from 
about 1 to 5%, preferably from about 1 to 3%, by weight of the 
composition. 
The alkaline proteolytic enzymes suitable for the present compositions 
include the various commercial liquid enzyme preparations which have been 
adapted for use in detergent compositions, enzyme preparations in powdered 
form being also useful although, as a general rule, less convenient for 
incorporation into the build liquid detergent compositions. Thus, suitable 
liquid enzyme preparations include "Alcalase" and "Esperase" sold by Novo 
Industries, Copenhagen, Denmark, and "Maxatase" and "AZ-Protease" sold by 
Gist-Brocades, Delft, The Netherlands. Esperase is particularly preferred 
for the present composition because of its optimized activity at the 
higher pH values corresponding to built detergent compositions. 
Among the suitable .alpha.-amylase liquid enzyme preparations are those 
sold by Novo Industries and Gist-Brocades under the tradenames "Termamyl" 
and "Maxamyl", respectively. 
The synthetic anionic detergent 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 test Surface Active Agents, Vol. II, by 
Schwartz, Perry and Berch, published in 1958 by Interscience Publishers, 
the disclosures pertaining to such detergent being hereby incorporated by 
reference. 
The most preferred anionic detergent compounds are the higher (10 to 18 or 
20 carbon atoms) alkyl benzene sulfonate salts wherein the alkyl group 
preferable contains 10 to 15 carbon atoms, most preferably being a 
straight chain alkyl radical of 12 or 13 carbon atoms. Preferably, such an 
alkyl benzene sulfonate has a high content of 3- (or higher) phenyl 
isomers and a correspondingly low content (usually well below 50%) of 2- 
(or lower) phenyl isomers; in other words, the benzene ring is preferably 
attached in large part at the 3, 4, 5, 6 or 7 position of the alkyl group 
and the content of isomers in which the benzene ring is attached at the 1 
or 2 position is correspondingly low. Typical alkyl benzene sulfonate 
surface active agents are described in U.S. Pat. No. 3,320,174. Of course, 
more highly branched alkyl benzene sulfonates may also be employed but 
usually are not preferred, due to their lack of biodegradeability. 
Other anionic detergents which are useful are the olefin sulfonate salts. 
Generally, these contain long chain alkenyl sulfonates or long chain 
hydroxyalkane sulfonates (with the OH being on the carbon atom which is 
not directly attached to the carbon atom bearing the --SO.sub.3 H group). 
The olefin sulfonate detergent usually comprises a mixture of such types 
of compounds in varying amounts, often together with long chain 
disulfonates or sulfate-sulfonates. Such olefin sulfonates are described 
in patents, such as U.S. Pat. Nos. 2,061,618; 3,409,637; 3,332,880; 
3,420,875; 3,428,654; 3,506,580; and British Pat. No. 1,129,158. The 
number of carbon atoms in the olefin sulfonate is usually within the range 
of 10 to 25, more commonly 10 to 18 or 20, e.g., a mixture principally of 
C.sub.12, C.sub.14 and C.sub.16, having an average of about 14 carbon 
atoms, or a mixture principally of C.sub.14, C.sub.16 and C.sub.18, having 
an average of about 16 carbon atoms. 
Another class of useful anionic detergents is that of the higher paraffin 
sulfonates. These may be primary paraffin sulfonates made by reacting long 
chain alpha-olefins and bisulfites, e.g., sodium bisulfite, or paraffin 
sulfonates having the sulfonate groups distributed along the paraffin 
chain, such as the products made by reacting a long chain paraffin with 
sulfur dioxide and oxygen under ultraviolet light, followed by 
neutralization with sodium hydroxide or other suitable base (as in U.S. 
Pat. Nos. 2,503,280; 2,507,088; 3,260,741; 3,372,188; and German Pat. No. 
735,096). The paraffin sulfonates preferably contain from 13 to 17 carbon 
atoms and will normally be the monosulfonate but if desired, may be di-, 
tri- or higher sulfonates. Typically, the di- and polysulfonates will be 
employed in admixture with a corresponding monosulfonate, for example, as 
a mixture of mono- and disulfonates containing up to about 30% of the 
disulfonate. The hydrocarbon substituent thereof is preferably linear but 
if desired, branched chain paraffin sulfonates can be employed, although 
they are inferior with respect to biodegradability. 
Other suitable anionic detergents are sulfated ethoxylated higher fatty 
alcohols of the formula RO(C.sub.2 H.sub.4 O).sub.m SO.sub.3 M, 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 alkylamino 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 
ethylene oxide groups may be increased to 4 or 5 and in some cases to as 
high as 8 or 9. Similarly, the salt-forming cation may be altered to 
obtain the 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 
menethanolamine, diisopropanolamine and trimethylamine. 
The poly-lower alkoxy higher alkanol sulfates may be employed in 
combination with other preferred anionic detergents such as the higher 
alkyl benzene sulfonates to provide optimum detergency in the present 
built liquid detergent compositions. A preferred polyethoxylated alcohol 
sulfate detergent is available from Shell Chemical Company and is marketed 
as Neodol 25-3S. 
Examples of higher alcohol polyethenoxy sulfates which may be employed in 
the liquid detergent compositions of the invention include: mixed 
C.sub.12-15 normal or primary alkyl triethenoxy sulfate, sodium salt; 
myristyl triethenoxy sulfate, potassium salt; n-decyl diethenoxy sulfate, 
diethanolamine salt; lauryl diethenoxy sulfate, ammonium salt; palmityl 
tetraethenoxy sulfate, sodium salt; mixed C.sub.14-15 normal primary alkyl 
mixed tri- and tetra-ethenoxy sulfate, sodium salt; stearyl pentaethenoxy 
sulfate, trimethylamine salt; and mixed C.sub.10-18 normal primary alkyl 
triethenoxy sulfate, potassium salt. 
Other useful anionic detergents include the higher acyl sarcosinates, e.g., 
sodium N-lauroyl sarcosinate; higher fatty alcohol sulfates, such as 
sodium lauryl sulfate and sodium tallow alcohol sulfate; sulfated oils; 
sulfates of mono- or diglycerides of higher fatty acids, e.g., stearic 
monoglyceride monosulfate; although, of these, the sodium higher alcohol 
sulfates have been found to be inferior to the polyethoxylated sulfates in 
detergency; aromatic poly(lower alkenoxy)ether sulfates, such as the 
sulfates of the condensation products of ethylene oxide and nonylphenol 
(usually having 1 to 20 oxyethylene groups per molecule, preferably 2 to 
12); polyethoxy higher alcohol sulfates and alkyl phenol polyethoxy 
sulfates having a lower alkoxy (of 1 to 4 carbon atoms, e.g., methoxy) 
substituent on a carbon close to that carrying the sulfate group, such as 
monomethyl ether monosulfate of a long chain vicinal glycol, e.g., mixture 
of vicinal alkane diols of 16 to 20 carbon atoms in a straight chain; acyl 
esters of isethionic acid, e.g., oleyl isethionates; acyl N-methyl 
taurides, e.g., potassium N-methyl lauroyl or oleyl taurides; higher alkyl 
phenyl polyethoxy sulfonates; higher alkyl phenyl polyethoxy sulfonates; 
higher alkyl phenyl disulfonates, e.g., pentadectyl phenyl disulfonate; 
and higher fatty acid soaps, e.g., mixed coconut oil and tallow soaps in a 
1:4 ratio. 
Among the aforementioned types of anionic detergents, the sulfates and 
sulfonates are generally preferred but the corresponding organic 
phosphates and phosphonates may also be employed when their contents of 
phosphorus are not objectionable. Generally, the water soluble anionic 
synthetic organic detergents, (including soaps), are salts of alkali metal 
cations, such as potassium, lithium, and especially sodium, although salts 
of ammonium and substituted ammonium cations, such as those previously 
described, e.g., triethanolamine, triisopropylamine, may also be used. 
A nonionic detergent may optionally be employed in minor amounts to 
supplement the anionic detergent compound in the present built liquid 
detergent compositions. When used in such combination with an anionic 
detergent, the amount of nonionic detergent will generally be below about 
10%, and preferably below about 5%, by weight, of the total composition. 
The nonionic detergents are usually poly-lower alkoxylated lipophiles 
wherein the desired hydrophile-lipophile balance is obtained from addition 
of a hydrophilic poly-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 
compounds are those wherein the alkanol is of 12 to 15 carbon atoms and 
which contain about 7 ethylene groups per mole, e.g., Neodol.RTM. 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 atoms 
content of the higher fatty alcohol is 12 to 13 and the number of ethylene 
oxide groups per mole averages about 6.5. The higher alcohols ae primary 
alkanols. Other examples of such detergents include Tergitol.RTM. 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 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 molecular weight 
non-ionics, 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 non-ionics 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 alkoxies 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 ethoxylated 
alkanols. Higher molecular weight alkanols and various other normally 
solid nonionic detergent compounds and surfactants may contribute to 
gelation of the liquid detergent composition and consequently, are 
normally omitted to 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 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 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, biodegradability and non-gelling 
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. 
The non-phosphate detergent builder salts are employed in the present 
compositions in amounts generally of from about 5 to 25%, and preferably 
from about 10 to 20%, by weight. Specific examples of non-phosphorous 
water-soluble inorganic builders include water-soluble inorganic 
carbonate, bicarbonate 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, 
polycarboxylates and polyhydroxysulfonates. Specific examples of 
polyacetate and polycarboxylate builders include sodium, potassium, 
lithium, ammonium 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 compositions, will 
usually be from about 25 to 75%, preferably 40 to 60%, 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. Pat. No. 3,812,041, issued 
May 21, 1974, both of which are hereby incorporated by reference contain 
detailed descriptions of a wide variety of suitable optical brighteners. 
Among the brighteners that are useful in the present liquid detergent 
compositions are: Calcofluor 5BM (American Cyanamid); Calcofluor White ALF 
(American Cyanamid); SOF A-2001 (Ciba); CDW (Hilton-Davis); Phorwite RKH, 
Phorwite BBH 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 compositions to provide 
additional properties, either functional or aesthetic. Included among the 
useful adjuvants are soil suspending or antiredeposition agents, such as 
polyvinyl alcohol, sodium carboxymethyl cellulose, hydroxypropylmethyl 
cellulose; thickeners, e.g., gums, alginates, agar agar; foam improvers, 
e.g., lauric myristic diethanolamide; foam destroyers, e.g., silicones; 
bactericides, e.g., tri-bromosalicyclanilide, 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 constituents, 
and their solubility in the liquid composition. 
The present 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 of a more dilute 
formulation but the greater quantity need will require additional 
packaging and will generally be less convenient for consumer use.

EXAMPLE 1 
Enzyme-containing built liquid detergent compositions A-E were formulated 
as set forth below in Table 1. The percentages shown indicate weight 
percent. 
TABLE 1 
______________________________________ 
A B C D E 
______________________________________ 
Sodium dodecylbenzene sulfonate 
7% 7% 7% 7% 7% 
Ethoxylated C.sub.12 -C.sub.15 alcohol 
7 7 7 7 7 
sulfate (3 mole EO/mole 
alcohol).sup.(1) 
Brightener 0.2 0.2 0.2 0.2 0.2 
Sodium Nitriliotriacetate 
15 15 15 15 15 
PBB.sup.(2) 1 1 1 1 1 
Perfume 0.3 0.3 0.3 0.3 0.3 
Protease enzyme.sup.(3) 
1 1 1 1 1 
Propylene glycol -- 20 20 20 20 
Borax -- -- 1 2 3 
H.sub.2 O balance 
Percent active enzyme after 
(a) 4 days at 110.degree. F. 
-- -- -- -- 98% 
(b) 6 days at 110.degree. F. 
0 15 61 86 88 
______________________________________ 
.sup.(1) Neodol 253S sold by Shell Oil Company. 
.sup.(2) Polar Brilliant Blue a 1% active dye solution. 
.sup.(3) "Esperase" sold by Novo Industries containing 5% enzyme, 75% 
propylene glycol, and balance H.sub.2 O having an activity of 8.0 KNPU/gm 
(Kilo Novo Protease units/gm). 
The enzyme activities of compositions A-E were tested after 6 days storage 
at 110.degree. F., the percent activity relative to the initial value 
being indicated in Table 1. The activity after 4 days was measured only 
for composition E. Compositions A and B were the only compositions which 
did not contain an enzyme stabilizing system in accordance with the 
invention, and manifested a total (composition A) or near total 
(composition B) loss of enzyme activity after 6 days. Compositions C, D 
and E reflect the marked improvement of enzyme stability attendant to the 
inclusion of propylene glycol and borax in the detergent composition. 
Compositions B through E were all clear, single-phase, homogeneous 
solutions which maintained their physical stability and clarity after 6 
months of storage at both room temperature and at 110.degree. F. 
Composition A which was not in accordance with the invention was 
physically unstable due to the absence of propylene glcyol which in 
addition to serving as an enzyme stabilizer (in conjunction with the 
aforementioned boron compound) promotes the solubility of the anionic 
detergents and the NTA builder in the aqueous composition. 
EXAMPLE 2 
Enzyme-containing built liquid detergent compositions F and G were 
formulated essentially similar to compositions A-E except that sodium 
citrate was used as the builder salt instead of sodium NTA. The 
compositions are shown below in Table 2. 
TABLE 2 
______________________________________ 
F G 
______________________________________ 
Sodium dodecyl benzene sulfonate 
7% 7% 
Ethoxylated C.sub.12 -C.sub.15 alcohol sulfate 
7 7 
(3 moles EO/mole alcohol) 
Brightener 0.2 0.2 
Sodium citrate 12 12 
PBB.sup.(1) 1 1 
Perfume 0.3 0.3 
Protease enzyme.sup.(2) 1 1 
Propylene glycol 20 20 
Borax -- 2 
H.sub.2 O balance 
Percent active enzyme after 4 days at 110.degree. F. 
20 95 
______________________________________ 
.sup.(1) Polar Brilliant Blue a 1% active dye solution. 
.sup.(2) "Esperase" sold by Novo Industries containing 5% enzyme, 75% 
propylene glycol, and balance H.sub.2 O having an activity of 8.0 KNPU/gm 
(Kilo Novo Protease units/gm). 
Composition G in accordance with the invention manifested an enzyme 
activity after four days of 95% as compared to composition F which 
contained no boron compound and consequently lost more than 3/4 of its 
initial enzyme activity. 
Both compositions were clear single-phase solutions which remained 
physically stable after six months of storage at both room temperature and 
110.degree. F. 
EXAMPLE 3 
Enzyme-containing built liquid detergent compositions H, I and J were 
formulated essentially similar to compositions F and G in Example 2 except 
that they contained a mixture of protease and alpha-amylase enzymes 
instead of a single protease enzyme. The compositions are shown below in 
Table 3. 
TABLE 3 
______________________________________ 
H I J 
______________________________________ 
Sodium dodecyl benzene sulfonate 
7% 7% 7% 
Ethoxylated C.sub.12 -C.sub.15 alcohol sulfate 
7 7 7 
(3 moles EO/mole alcohol) 
Brightener 0.2 0.2 0.2 
Sodium citrate 12 12 12 
PBB.sup.(1) 1 1 1 
Perfume 0.3 0.3 0.3 
Protease enzyme.sup.(2) 1 1 1 
.alpha.-Amylase enzyme.sup.(3) 
0.4 0.4 0.4 
Propylene glycol 20 20 20 
Borax -- 1 3 
H.sub.2 O balance 
Percent active enzyme after 4 days at 110.degree. F. 
.alpha.-amylase enzyme 50% 67% 87% 
Protease enzyme 30 73 94 
______________________________________ 
.sup.(1) Polar Brilliant Blue a 1% active dye solution. 
.sup.(2) "Esperase" sold by Novo Industries containing 5% enzyme, 75% 
propylene glycol, and balance H.sub.2 O having an activity of 8.0 KNPU/gm 
(Kilo Novo Protease units/gm). 
.sup.(3) "Termamyl" sold by Novo Industries containing 5% enzyme, 18% Nac 
and balance H.sub.2 O having an activity of 120,000 Novo amylase units pe 
gram. 
Compositions I and J in accordance with the invention demonstrated a 
markedly more stable enzyme activity after four days for both the protease 
and amylase enzymes relative to composition H which contained no boron 
compound and consequently lost about 1/2 of its initial amylolytic 
activity and about 1/3 of its initial proteolytic activity during the 
period of four days. 
All three compositions were clear single-phase solutions which remained 
physically stable after six months of storage.