Note: Descriptions are shown in the official language in which they were submitted.
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~ 203~7
C 547 (R)
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The present invention relates to an enzymatic liquid
composition and more particularly to an enzymatic liquid
detergent composition with an improved storage stability.
Liquid detergent compositions are well known in the art
and, after the revival of interest in enzymes for inclusion
in detergent compositions, several proposals have been made
in the art for enzymatic liquid detergent compositions.
Despite these proposals, such enzymatic liquid
detergent compositions have not been put on the market to
any significant extent, primarily because of severe instabil-
ity problems incurred with the incorporation of enzymes in
liquid detergent compositions. This problem is well
recognized in the art, and it has for instance been proposed
to reduce the instability of enzymes in liquid detergent
compositions by incorporating stabilizing systems in such
compositions. Such proposals include the use of polyols
like glycerol , sorbitol; furthermore Ca-salts, alkoxy-
; alcohols, dialkylglycolethers, and mixtures of polyvalent
alcohols with polyfunctional aliphatic amines. These
systems are, however, primarily intended for inclusion inenzymatic liquid compositions with a pH value ranging from
relatively acid to slightly alkaline.
It has now been found that the storage stability of
- aqueous enzymatic liquid compositions can be significant-
ly improved by the inclusion therein of an effective amount
of a stabi~izing system comprising a polyfunctional a~ino compound and
boric acid or a boron-equivalent thereof as hereinafter
'l more specifically defined.
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The polyfunctional amino compounds of the invention are
aliphatic organic compounds comprising at least one amine ~ - -
grouping and at least two hydroxyl groups. It is to be under-
stood that quaternary ammonium compounds are not included ~ -
in the term "polyfunctional amino compounds".
Typical examples of the polyfunctional amino compounds
of the invention are polyalkanolamines such as diethanol- ~;
amine, triethanolamlne, di-isopropanolamine, tri-isopropanol-
amine, furthermore tris(hydroxymethyl) aminomethane.
The amount of the polyfunctional a'mino compound used
is generally from 2-25, preferably from 4-15% by weight of
the composition. Triethanolamineis the preferred poly-
functional amino compound in protease-containing liquids.
The boric acid or boron-equivalent thereof (a boron
compound capable of reacting with the polyfunctional amino
; compound, such as boric oxide, borax and other alkali metal
borates such as sodium ortho, meta- and pyroborate) is used in an amount
of ~enerally 0.25 to 15g preferably 0.5-10% by wei~ht of the composition,
the boron equivalent being calculated on the basis of boric acid.
i 20 Preferably the amount is such that the weight ratio of the
polyfunctional amino compound to the boric acid or boron-
equivalent (calculated on the basis of the boric acid) thereof
'l varies from 10:1 to 1:2, preferably 7:1 to 2:1.
The stabilizing system, comprising the polyfunctional
amino compound and the boric acid or boron-equivalent there-
;~ of, may be incorporated in the liquid enzyme system either
by adding the constituents as such to the liquid, or by
adding the separately prepared stabilizing system, e.g. as
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1~92037 c 547 (R)
the polyfunctional amino compound/boric acid or boron-
equivalent reaction product. Mixtures of various poly-
functional amino compounds may also be used, as well as
mixtures of a polyfunctional amino compound with a polyhydroxy
compound not containing an amino grouping, e.g. erythritan.
It has furthermore been found that the inclusion of up to 10~ by weight
of saccharose further enhaIlces the storap,e stability.
me enzymes to be incorporated can be proteolytic, amylolytic and
cellulolvtic enzymes as well as mixtures thereof. ~hey may be Or any ~ -
suitable origin, such as vegetable, animal, bac'terial, fungal andyeast
origin. However, their choice is governed by several factors such as
pH-activity and/or stability optima, thermostability, stability versus
active detergents, builders and so on. In this respect bacterial or f~ngal
~; enzymes are preferred, such as bacterial amylases and proteases, and fun~gal
'j 15 cellulases. Thepresentinventionisofparticularbenefit for enzymatic
liquid detergents having a pH of above 7.5, particularly
~`~ those incorporating bacterial proteases of which the pH-
optima lie in the range between 8.5-10.5, but it is to be under-
,;~ .
stood that enzymes with a somewhat lower or higher pH-optimum can
still be used in the composition o,! the invention, benefitinF~ from it~
Suitable examples of such proteases are the subtilisins
;i which are obtained from particular strains of B . subtilis and
B. licheniformis, such as the commercially available
; subtilisins Maxatase (~) (ex Gist-Brocades N.V., Delft,Holland)
and Alcalase(~) (ex Novo Industri A/S, Copenhagen, Denmark).
As stated above, the present invention is of particular
benefit for enzymatic liquid detergents incorporating enzymes
- with pH activity and/or stability optima of ab~ve 8 ~ 5, such
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C 547 (R)
~.09203~7
enzymes also being commonly called high-alkaline enzymes.
Particularly suitable is a protease obtained from a
strain of Bacillus, having maximum activity throughout the
pH range of 8-12, developed and sold by Novo Industri A/S
under the registered trade name Esperase ~ The preparation
of this enzyme and analogous enzymes is described in British
patent specification 1,243,784 of Novo.
High alkaline amylases and cellulases can also be used,
e.g. ~-amylases obtained from a special strain of
B. licheniformis, described in more detail in British patent
specification 1,296,839 (Novo).
The amount of enzymes present in the liquid composition
:~ may vary from 0.001 to 10% by weight, and preferably from
0.01 to 5% by weight. This amount is of course highly
dependent upon the activity of the enzyme used.
i When the liquid compositionso the invention are detergent
compositions, these liquid detergent compositions comprise
as a further essential ingredient an active detergent
material, which may be an anionic, nonionic, cationic,
zwitterionic or amphoteric detergent material.
Examples of anionic synthetic detergents are salts
(including sodium, potassium, ammonium, and substituted
ammonium salts such as mono-, di- and triethanolamine salts)
of Cg-C20 alkylbenzenesulphonates, C8-C22 primary or
secondary alkanesulphonates, C8-C24 olefinsulphonates,
sulphonated polycarboxylic acids, prepared by sulphonation of
the pyrolyzed product of alkaline earth metal citrates, e.g.
as described in British patent specification 1,082,179,
,_~ C 547 (R)
~z037
C8-C22 alkylsulphates, C8-C24 alkylpolyglycolethersulphates
(containing up to 10 moles of ethylene oxide); further examples
are described in "Surface Active Agents and Detergents"
(Vol. I and II by Schwartz, Perry and Berch).
Examples of nonionic synthetic detergents are the
condensation products of ethylene~oxide, propylene oxide and/or
butylene oxide with C8-C18alkylphenols, C8-C18primary or
secondary aliphatic alcohols, C8-C18 fatty acid amides;further
examples of nonionics include tertiary amine oxides with one
C8-C18 alkyl chain and two C1 3 alkyl chains. The above
reference also describes further examples of nonionics.
The average number of moles of ethylene oxide and/or
` propylene oxide present in the above nonionics varies from
1-30; mixtures of various nonic;nics, including mixtures of
nonionics with a lower and a higher degree of alkoxylation,
, may also be used.
Examples of cationic detergentsare the quaternary
ammonium compounds such as alkyldimekhylammonium halogenides,
but such cationics are less preferred for inclusion in
enzymatic detergent compositions.
Examples of amphoteric or zwitterionic dekergents are
N-alkylamino ac1ds, sulphobetaines, condensation products of
fatty acids with protein hydrolysates, but owing to their
relatively high costs they are usually used in combination with
an anionic or a nonionic detergent. Mixtures Or the various
types of active detergents may also be used, and preference
is given to mixtures of an anionic and a nonionic detergent
active. Soaps (in the form of their sodium, potassium, and
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C 547 (R)
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substituted ammonium salts such as triethanolamine salts)
of C8-C22 fatty acids, as well as o polymer~ed fatty
acids, may also be used and may exert a beneficial
influence on the foaming behaviour of the final composition.
The amount of the active detergent material varies from
10 to 60%, when mixtures of e.g. anionics and nonionics are
used the relative weight ratio varies from 1:1 to 1:10.
When a soap is also incorporated, the amount thereof is from
1-40% by weight.
Although the liquids may contain up to 40% of a suitable
builder, such as sodium, potassium and ammonium or
substituted ammonium pyro-, and tripolyphosphates, nitrilo-
triacetates, etherpolycarboxylates, citrates, carbonates,
orthophosphates, polyelectrolytessuch as polyvinylmethyl-
ether/maleic anhydride copolymers and so on, the present
invention is of particular benefit for use in unbuilt liquid
detergents. ~
The amount of water present in the compositions of the `
invention varies from 5 to 70% by weight.
Other conventional materials may also be present in the
liquid detergent compositions of the invention, for example
soil-suspending agents, hydrotropes, corrosion inhibitors,
dyes, perfumes, silicates, optical brighteners, suds
` boos'cers, suds depressants, germicides, anti-tarnishing
agents, opacifiers, fabric softening agents, oxygen-
liberating bleaches such as sodium perborate or per-
carbonate with or without bleach precursors, buffers and
the like.
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The pH of the final composition preferably lies within
the range of 7.5 to 11.0, and is, if necessary, adjusted
to a value within that range by addition of a suitable acid
or alka'ine material.
The invention will now be further illustrated by way
of Example. In the Examples the percentages are by weight.
' The enzyme half-life time extension ~actor was determined
in the following way:
A continuously withdrawn sample from a solution to
be tested was continuously diluted (1:200) and continuously
assayed on enzymatic activity (for proteolytic activity
casein was used as a substrate). The logarithms of
residual activity were plotted against the time, and the
first order rate constant K~ was computed.
, 15 The enzyme half-life time extension factor (Ft) is
" defined as
F = K1 (without stabilizing system) ty/2 (with stabilizing system)
~ .
~,! K1 (with stabilizmg system) ty/2 (without stabilizing system)
ty/~ = time at which the enzymatic activity (y) is half
the initial enzymatic activity.
Example I
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Tests were carried out with a bacterial subtilisin-
type protease, Alcalase ~ ex Novo, (activity 10.6 Au/g)
in the followin~ aqueous system comprising:
0.2 M pentasodiumtripolyphosphate
` 0.12 M dimethylglycine
1.7 g Alcalase ~
The pH of this system was 10.0, and the temperature
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; 57C. The rate of loss of enzyme activity in this system
with and without the stabilizing system was measured and
the enzyme half-life extension factor (Ft) was determined.
; The following results were obtained:
_ Ft
No. Additive (in % by weight) value
_ ~ .
1 6% tris(hydroxymethyl)aminomethane + 6 . 2% borax 7.5
2 6% tris(hydroxymethyl)aminomethane +9.4% borax 13.7 . .
; 3 10% tris(hydroxymethyl)aminomethane +15.7% borax 23.5
~; 4 5% tris(hydroxymethyl)aminomethane +5% erythritan
412.4% borax 18. 6
10% triisopropanolamine + 8.4% borax12.7
6 triethanolamineorthoborate (prepared from 10%
. triethanolamine and 12.8% borax) 5.2 ~:
; ~ 61o diethanolamine +5.41 borax 2.5
Example II
In a manner analogous to that of Example I, tests were
carried out with a bacterial protease, Esperase ~ (activity
, 41.5 KNPU/g) in the same system, but at 60C .
A control-composi~tion with 8.81 borax alone gave a
Ft-value of 0.7; with 2.5, 7.5 or 12.5 triethanolamine alone
Ft-values o~ 1.0, 1.1 and 1.0 were obtained.
With systems according to the invention the following
results were obtained:
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No. Additive (% by wei.ghk) valu~
8 12% triethanolamineorthoborate 5.9
i 9 12% triethanolamineorthoborate (prepared in 4. 8
situ with H3BO3)
10 10% triethanolamineorthoborate 4.3
11 8% triethanolamineorthoborate 3~0
12 6% triethanolamineorthoborate 2.1
; 13 4% triethanolamineorthoborate 2~0
14 2~o triethanolamineorthoborate 1.6
10 15 8% triethanolamine + 5.6% borax 2.6
. 16 8% triethanolamine + 6~8% borax 3.4
17 8% triethanolamine + 8.6% borax 3~4
18 8% triethanolamine + 10. 2% borax 3~2
~, 19 6% diethanolamine + 5.4% borax 3.2
v 15 20 8% tris(hydroxymethyl)aminomethane + 7.7% borax 1.7
- Example III
Tests were carried out in a manner analogous to that
of Example I with a bacteri.al amylase (Thermamyi ~ ex Novo~
20 in an aqueous system comprising:
0.12 M. pentasodium-tripolyphosphate
0.1 M. glycine
0~5 g Thermamyl (activity 450 KNU/g)
.:` The pH was 9.95, and the temperature was 59.3C.
25 The following results were obtained:
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_ Ft
No.Additive (% by weight) value
212% tris(hydroxymethylamino)methane -~ 3.15% borax 1.~1
226% tris(hydroxymethylamino)methane + 9.45% borax 2.4
2310% tris(hydroxymethylamino)methane +15.75% borax 4.6
246.28% triethanolamineorthoborate 1.4 .
Example IV
The following aqueous enzymatic liquid detergent
compositions were prepared by adding 0.5% of an enzyme .
slurry (Maxa~ase (~) 500,000, a bact.erial subtilisin-type
protease ex Gist-Brocades, Delft, Holland, having an
activity of 500,000 Delft Units/gr) to the tabulated
formulations, and their storage stability at 37C was
.I determined.
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% by weight
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linear C16-C18 alcohol, 21 21 21 21
: condensed with 18 moles
of ethylene oxide
linear Cg-Cll alcohol 7 7 7 7
condensed with 8 moles
. of ethylene oxide .
.. sodium xylene sulphonate 3 3 3 3
. dimerized oleic acid 6.5 6.5 6.5 6.5 :~
: 10 triethanolamine 10 10 10 10
lauryl alcohol, condensed 7 7 7 7 :.
with2moles ofethyleneoxide
monoethylether of diethylene 10 10 10 10
.~ glycol
wat~er 30.5 25.5 20.5 15.5
: stabilizing system, comprising 5 10 15 20
; boric acid and triethanolamine .
. in a weight ratio of 2:3,
separately prepared
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pH 9 9 9 9
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The half-life time of the
nzymatic activity was i
. obtained after: 6~ 8~i after 11 after 11
weeks weeks weeks weeks
.; . still still
above 50% above 50%
.~ residual residual
act. activity
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.~ rhe residual enzymatic
:. ctivity after 11 weeks'
. storage was: 32% 35% 60% 70%
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Example V
Repeating Example IV, but using 0. 5% of a bacterial
protease Esperase ~ ex Novo (act. 9 KNPU) instead of Alcalase,
the liquidshaving a pH of 9.0 gave the following results:
after 9 weeks of storage the products A-D still had a
residual proteolytic activity well above 50% of the initial
activity. These residual activities were 60%, 60% and 85%
respectively.
Example VI
Example V was repeated, but the storage test was now
carried out at 50C. Products A, B, and C reached the half-
life enzyme activity level after 3~, 4 and 10 weeks'
storage respectively. Product D had a residual enzyme
activity of 88% after 7 week~.
.
; 15 Example VII
Aqueous systems containing F.sperase(~) (20,000 G.U./ml)
were stored at 37C. The half-life time was assessed in days,
using systems with additives as given below. The results are ~ -
shown in the table.
pl~ half-life time
-~ --- - in days
;~ + 24.8 g/l boric acid 10.5 6 -
+ 24.8 g/l boric acid + 10~, saccharose10.5 8
+ 2 4 . 8 g / l boric acid~ 5% triethanolamine 10, 5 9
10% saccharose-~ 5% triethanol amine 10.2 6
24.8 g/l boric acid ~ 5% triethanol amine 10.5 20
+ 10% saccharose _
pH adjusted with NaOH
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