Note: Descriptions are shown in the official language in which they were submitted.
~g2~
1 c 7296 (P~)
DETERGENT COMPOSITION
Field of the Invention
5 The present invention relates to an aqueous liquid detergent
product particularly adapted for use in a machine
dishwasher.
Background and Prior Art
10 Liquid automatic dishwasher detergent compositions, both
aqueous and non-aqueous, have recently received much
attention and the aqueous products have achieved commercial
popularity.
15 The acceptance and popularity of the liquid formulations as
compared to the more conventional powdered products stems
from the convenience and pe.~o~l~.anc~ u~ ~n~ ul~ ~Loducts.
However the currently available and proposed liquid product
formulations are based on the concept of the conventional
20 machine dishwashing powder compositions which are highly
alkaline and highly built products containing a chlorine
bleach (see for example EP-A-0,517,308 and EP-A-517,309).
It has now surprisingly been found that a mild and yet quite
effective aqueous liquid machine dishwashing detergent
composition can be formulated based on certain surfactants
and proteolytic enzymes wherein there is an apparent
synergistic effect between the active and the protease
enzyme, especially in the removal of protein soil.
The use of glycosides in detergent compositions has been
disclosed in a number of documents. WO 86/05187 (Staley)
discloses laundry detergent compositions comprising
glycoside surfactant and enzyme. Various enzymes are
35 mentioned.
DE 38 33 047 discloses acidic powdered dishwashing
compositions containing alkyl glycoside în combination with
2~88~3~
2 C 72~6 (R)
other surfactant and amylase. These compositions are acidic
and have solution pH below 6.
Summary of the Invention
5 According to the invention there is provided a chlorine
bleach-free aqueous liquid machine dishwashing detergent
composition comprising :
(a) from 0.0002 to 0.05 Anson units per gram of the
composition of a proteolytic enzyme;
(b) from 5 to 90% by weight of a detergency builder;
(c) from 1 to 40% by weight of sodium or potassium
silicate having SiO2:Na2O or Sio2:K2o ratio of from
about 2.0 to about 3~2.
(dj fro.n J ~0 5u~ by weight of an organic surfactant
selected from the group of:
(i) glycoside surfactants;
(ii) anionic surfactants with a hydrophilic head
group which is, or which contains a sulphate
or sulphonate group and a hydrophobic portion
which is or which contains an alkyl or
alkenyl group of 8 to 22 carbon atoms;
(iii) ethoxylated fatty alcohols of formula
Ro(cH2cH2o)nM
where R is an alkyl group of 6 to 16 carbon
atoms and n has an average value which is at
least four and is sufficiently high that the
HLB value of the ethoxylated fatty alcohol is
10.5 or greater, with the proviso that if
ethoxylated fatty alcohol (iii) is used
without anionic surfactant (ii) the majority
of its alkyl groups R contain 6 to 12 carbon
atoms; and
(iv) mixtures thereof;
2~8~23~
3 C 7296 (R)
(e) water, said composition having a pH of 7 to 11, if
added deionised water at a concentration of 2 g/l.
In a second aspect this invention provides a method of
5 washing crockery and/or glassware comprising exposing the
crockery and/or glassware to a mixture of water and a
detergent composition as specified above. In another aspect
the invention provides use of such a composition in machine
dishwashing.
Detailed Description
The Proteolytic Enzyme
Protease can, for example, be used in an amount ranging from
15 about the order of 0.0002 to about the order of 0.05 Anson
units per gram of the detergent composition, preferably
vï to ~.u25 Anson units. Expressed in other Ullit~ tlle
protease can also be included in the compositions in amounts
of the order of from about 0.5 to 100 GU/mg of the detergent
20 composition. Preferably, the amount ranges from 1 to 50, and
particularly preferably from 2 or even 5 to 15 or 20 GU/mg
of composition.
A GU is a Glycine Unit, defined as the proteolytic enzyme
25 activity which, under standard conditions, during a 15-
minute incubation at 40C with N-acetyl casein as substrate,
produces an amount of NH2-group equivalent to 1 micromole of
glycine.
Enzyme activities are sometimes also measured in kilo Novo
units (KNPU): a measurement depending on the type of
protease and assay used. We have found that the KNPU/AU
ratio is in the range of about 3:1 to 5:1 for Alcalase,
Esperase and Savinase and for the purpose of these
formulations it is not necessary to be more precise.
Preferred examples of protease enzyme to be used in the
present compositions are the subtilisin varieties sold as
2 ~ 3 ~
4 C 7296 (R)
Savinase (TM of Novo-Nordisk A/S) or Maxacal (TM of Gist-
Brocades/IBIS) or as Opticlean (ex MKC) or AP122 (ex Showa
Denko), which has pI approximately 10. Other useful examples
of proteases include Maxatase, Esperase, Alcalase (Trade
5 Marks), protinase K and subtilisin BPN'. Protinase K can
also be used.
Orqanic surfactant
10 Glycoside Surfactant
This will be nonionic in character and of course includes
glycoside residues. Suitably it is of the general formula :
o
Il
R(R')t(G)x or RCO(R'O)t(G)X
in which G is a residue Ol a pentose OL n2xose, k ~ iS an
alkoxy group, x is at least unity and R is an organic
hydrophobic group which is ~referably aliphatic, either
saturated or unsaturated, notably straight or branched
alkyl, alkenyl, hydroxyalkyl or hydroxyalkenyl. However, it
may include an aryl group, for example alkyl-aryl, alkenyl-
aryl and hydroxyalkyl-aryl. It is envisaged that R may be
from 6 to 20 carbon atoms.
Particularly preferred is that R is alkyl or alkenyl of 7 to
14 or 16 carbon atoms, especiall,v 7 to 12.
The value of t in the general formula above is preferably
zero, so that the -(R'O)t- Ullit of the general formula is
absent. In that case the general formula becomes :
o
Il
RO(G)X or RCO(G)X
If t is non-zero, it is preferred that R'O is an ethylene
oxide residue. Other possibilities are propylene oxide and
glycerol residues. If the parameter t is non-zero so that
2 0 ~
C 7296 (R)
R'O is present, the value of t (which may be an average
value) will preferably lie in the range from 0.5 to 10.
The group G is typically derived from fructose, glucose,
5 mannose, galactose, talose, gulose, allose, altrose, idose,
arabinose, xylose, lyxose and/or ribose. Preferably, the G
is provided substantially exclusively by glucose units.
Intersaccharide bonds may be from a 1-position to a 2, 3, 4
or 6-position of the adjoining saccharide. ~ydroxyl groups
10 on sugar residues may be substituted., e.g. etherified with
short alkyl chains of 1 to 4 carbon atoms. Preferably a
sugar residue bears no more than one such substituent.
I'he value x, which is an average, is usually termed the
15 degree of polymerization. Desirably x varies between 1 and
8. Values of x may lie between 1 and 3, especially l and
1.8.
Alkyl polyglycosides of formula RO(G)X, i.e. a formula as
20 given above in which t is zero, are available from BASF and
Henkel.
Alkyl polyglycosides of particular interest have x in the
narrow range from 1 or 1.2 up to 1.4 or especially 1.3. If x
25 exceeds 1.3, it preferably lies in the range from 1.3 or 1.4
to 1.8.
When x lies in the range from 1 to 1.4, it is preferred that
R is C8 to C14 alkyl or alkenyl.
0-alkanoyl glucosides are described in International Patent
Application WO 88/10147 (Novo Industri A/S). In particular
the surfactants described therein are glucose esters with
the acyl group attached in the 3- or 6-position such as 3-0-
acyl-D-glucose or 6-0-acyl-D-glucose. Notable are 6-0-
alkanoyl glucosides, in which the alkanoyl group
incorporates an alkyl or alkenyl group having from 7 to 13
preferably 7, 9 or 11 carbon atoms. The glucose residue may
20882~
6 C 7296 (R)
be alkylated in its l-position with an alkyl group having
from 1 to 4 carbon atoms, such as ethyl or isopropyl.
Alkylation in the l-position enables such compounds to be
prepared by regiospecific enzymatic synthesis as described
5 by Bjorkling et al. (J. Chem. Soc., Chem. Commun. 1989
p934).
While esters of glucose are contemplated especially, it is
envisaged that corresponding materials based on other
10 reducing sugars, such as galactose and mannose are also
suitable.
Anionic surfactant
Preferred anionic surfactants are one or a mixture of:
primary alkyl sulphate of formula:
RlOS03M
where Rl is a primary alkyl group of 8 to 18 carbon atoms
and M is a solubilising cation,
fatty acid ester sulphonate of formula
R2CHCo2R3
I
SO3M
25 where R2 is an alkyl group of 6 to 16 carbon atoms, R3 is an
alkyl group of 1 to 4 carbon atoms and M is a solubilising
cation,
alkyl benzene sulphonate of formula
R4
SO3M
where R is an alkyl group of 10 to 16 carbon atoms and M is
a solubilising cation,
alkyl ether sulphate of formula
R10 (CH2CH20) nS3M
where Rl is a primary alkyl group of 8 to 18 carbon atoms, n
has an average value in the range from 1 to 6 and M is a
208~230
7 C 7296 (R)
solubilising cation.
Especially preferred as surfactant is primary alkyl
sulphate. In its general formula
R SO3M
the solukilising cation may be a range of cations which are
general monovalent and confer water solubility. Alkali
metal, notably sodium, is especially envisaged. Other
10 possibilities are ammonium and substituted ammonium, such as
trialkanolammonium.
The alkyl group Rl may have a mixture of chain lengths. It
is preferred that at least two thirds of the R1 alkyl groups
15 have a chain length of 8 to 14 carbon atoms. This will be
the case if Rl is coconut alkyl, for example.
If the surfactant is fatty acid ester sulphonate, alkyl
benzene sulphonate or alkyl ether sulphonate the
solubilising cation M may be a range OL cations as discussed
above for alkyl sulphate.
In the general formula for fatty acid ester sulphonate:
R CHCO2R
SO3M
the group R2 may have a mixture of chain lengths. Preferably
at least two thirds of these groups have 6 to 12 carbon
atoms. This will be the case when the moiety:
R CHCO2-
I
is derived from a coconut source, for instance.
The group R may be any C1 to C4 alkyl group. Straight chain
alkyl may be preferred, notably methyl or ethyl.
2~8~23~
~ C 7296 (R)
In the general formula formula of alkyl benzene sulphonate:
R4
S03M
5 The group R4 may be a mixture of chain lengths. Preferred
are straight chains of ll to 14 carbon atoms.
In the general formula for alkyl ether sulphate:
R10 (CH2CH20) nS3M
the group Rl is as discussed for alkyl sulphate. Preferably
n has an average value of 2 to 5.
Nonionic surfactant
Ethoxylated fatty alcohol may be used alone or in admixture
with anionic surfactants, especially the preferred
surfactants ab~e. ~ow~ L i~ is ustd alone then the
fatty alcohol must be of limited chain length so that
average chain lengths of the alkyl group R in the general
formula:
Ro(cH2cH2o)nH
is from 6 to 12 carbon atoms. This is preferred in any
event, and especially preferred if the weight of anionic
surfactant is less than half the weight of ethoxulated fatty
alcohol.
Notably the group R may have chain lengths in a range from 9
to 11 carbon atoms.
An ethoxylated fatty alcohol normally is a mixture of
molecules with different numbers of ethylene oxide residues.
Their average number, n, together with the alkyl chain
length, determines whether the ethoxylated fatty alcohol has
35 a hydrophobic character (low HLB value) or a hydrophilic
character (high HLB value). For this invention the HLB value
should be 10.5 or greater. This requires the average value
of n to be at least 4, and possibly higher. The numbers of
2~8~23~
g C 7296 (R)
ethylene oxide residues may be a statistical distribution
around the average value. However, as is known, the
distribution can be affected by the manufacturing process or
altered by fractionation after ethoxylation.
Particularly preferred ethoxylated fatty alcohols have a
qroup R which has 9 to ll carbon atoms while n is from 5 to
8.
10 Other surfactant
The above surfactant, or a mixture of two or more of them,
may possibly be accompanied by some other detergent active,
usually in a lesser quantity. Preferably the amount of any
other detergent surfactant will be no more than one third of
15 the total weight of detergent surfactant present, or even no
more than one quarter.
If other surfactant is included it may be anionic or
nonionic in character, or possibly amphoteric or
zwitterionic. Cationic surfactant is possible if anionic is
absent, but is not preferred. Soap may optionally be
included, as well as non-soap surfactants.
One significant possibility is the use of a surfactant or
25 mixture of surfactants of the above specified anionic and~or
nonionic types, together with glycoside surfactants of the
above specified type.
As mentioned, the amount of glycoside surfactant, anionic
surfactant and/or ethoxylated fatty alcohol surfactant will
be from 3 to 50% by weight of the composition. Desirably the
total amount of surfactant lies in the same range. Preferred
ranges, both for the specified surfactant and total
surfactant are 3 to 30% by weiqht, more preferably, in the
35 range from 5 or 10% to 25% by weight.
Deterqent Builder_Materials
The cleaning compositions of this invention can contain all
2088230
C 7296 (R)
manner of detergent builders commonly taught for use in
automatic dishwashing or other cleaning compositions. The
builders can include any of the conventional inorganic and
organic water-soluble builder salts, also insoluble
inorganic builders or mixtures thereof, and may comprise
from 5 to 90% by weight of the detergent composition.
Typical of the well-known inorganic builders are the sodium
and potassium salts of the following: pyrophosphate,
10 tripolyphosphate, orthophosphate, carbonate, bicarbonate,
sesquicarbonate and borate. Other non-phosphorous salts
including (insoluble) crystalline and amorphous
aluminosilicates (e.g. zeolites) may be used as well.
15 Preferred builders can be selected from the group consisting
of sodium tripolyphosphate, sodium carbonate, sodium
blcarbonate and mixtures thereof. When present ln clle~
compositions, sodium tripolyphosphate concentrations will
usuaIly range from 2% to 40%, preferably from 5% to 30%.
20 Sodium carbonate and bicarbonate, when present, can range
from 10% to 50%, preferably from 20% to 40% by weight of the
cleaning compositions. Potassium pyrophosphate is a
preferred builder in gel formulations, where it may be used
at from 3 to 30%, preferably from 10 to 20%.
Organic detergent builders can also be used in the present
invention. They are generally sodium and potassium salts of
the following: citrate, malonate or succinate substituted
with a C8 to C24 alkyl group, nitrilotriacetates, phytates,
30 polyphosponates, oxydisuccinates, oxydiacetates,
carboxymethyloxy succinates, tetracarboxylates, starch,
oxidized heteropolymeric polysaccharides, and polymeric
polycarboxylates such as polyacrylates of molecular weight
of from about 5,000 to about 200,000. Polyacetal
35 carboxylates such as those described in U.S. Patent Nos.
4,144,226 and 4,146,495 may also be used.
2~8823~
11 C 7296 (R)
Non-phosphate builders are particularly preferred for
environmental reasons.
Sodium citrate is an especially preferred builder. When
5 present, it is preferably used in an amount from about 1% to
about 75% of the total weight of the detergent composition,
especially 10 to 50% by weight.
The foregoing detergent builders are meant to illustrate but
10 not limit the types of builder that can be employed in the
present invention.
Silicate
The compositions of this invention contain sodium or
15 potassium silicate at a level of from about 1 to about 40%
by weight of the cleaning composition, more preferably from
5 to 25%, even more preferably from / cu 2~ hlS material
is employed as a cleaning ingredient, source of alkalinity,
metal corrosion inhibitor and protector of glaze on china
20 tableware. The sodium or potassium silicate usuable herein
will have a ratio of SiO2:Na20 or Sio2:K2o of from about 2.0
to about 3.2. Some of the silicate may be in solid form.
Useful is sodium silicate having a ratio of sio2 : Na2O of
higher than 2.0, preferably at least 2.4.
If a composition contains less than ~0~ silicate, we prefer
to include a zinc salt, such as zinc sulphate, especially if
the composition dissolves to give an alkaline pH, e.g. pH
over 8.5. Such a zinc salt serves to protect glassware from
30 attack by an alkaline wash liquor, and may suitably be used
in amounts from 0.1 to 3% by weight.
Other Optional Inqredients
35 Bleach system
Compositions according to the present invention are free
from chlorine bleach compounds but may contain a peroxygen
bleach component. If present the amount will preferably lie
20~823~
12 C 7296 (R)
in a range from 1 to 30% by weight.
A peroxygen bleach which may be employed is for example
sodium perborate. This is preferably accompanied by a b~each
5 activator which allows the liberation of active oxygen
species at a lower temperature. A preferred bleach activator
is tetraacetyl ethylene diamine (TAED) but other activators
for perborate are known and can be used. The amounts of
peroxygen bleach and bleach activator in an individual
10 composition preferably do not exceed 20~ and 15% by weight
respectively.
Another peroxygen bleach is sodium percarbonate. Yet another
is sodium monopersulphate. Further peroxygen bleaches which
15 may be used are alkyl, alkenyl and aryl peroxy organic acids
and their metal salts. Typical peroxy acids include
(i) ~ervxi~el-zoic acid and ring-substituted
peroxybenzoic acids, e.g. peroxy-~-naphthoic acid
(ii) aliphatic and substituted aliphatic monoperoxy
acids, e.g. peroxylauric acid and peroxystearic
acid
(iii)1,12-diperoxydodecanedioic acid (DPDA)
(iv) 1,9-diperoxyazelaic acid
(v) diperoxybrassylic acid; diperoxysebacic acid and
diperoxyisophthalic acid
(vi) 2-decyldiperoxybutane-1,4-dioic acid.
(vii)phthaloylamidoperoxy caproic acid (PAP).
Thickeners and Stabilizers
30 Thickeners are often desirable for liquid cleaning
compositions. Thixotropic thickeners such as smectite clays
including montmorillonite (bentonite), hectorite, saponite,
and the like may be used to impart viscosity to liquid
cleaning compositions. Silica, silica gel, and
35 aluminosilicate may also be used as thickeners. Use of clay
thickeners for automatic dishwashing compositions is
disclosed, for example, in U.S. Patents Nos. 4,431,559;
4,511,487; 4,740,327; 4,752,409. Use of salts of polymeric
2~23~
13 C 7296 (R)
carboxylic acids is disclosed, for example, in UK Patent
Application GB 2,164,350A. Commercially available bentonite
clays include Korthix H and VWH ex Combustion Engineering,
Inc.; Polargel T ex American Colloid Co.; and Gelwhite clays
(particularly Gelwhite GP and H) ex English China Clay Co.
Polargel T is preferred as imparting a more intense white
appearance to the composition than other clays.
Various polymers may be included. ~hese may in particular
10 assist in detergency building or be polymeric thickeners,
which may be used alone or jointly with other types of
thickeners. Notable are polymers containing carboxylic or
sulphonic acid groups in acid form or wholly or partially
neutralised to sodium or potassium salts, the sodium salts
15 being preferred. Preferred polymers are homopolymers and
copolymers of acrylic acid and/or maleic acid or maleic
alnhydr~e. ~1 especial interest are polyacrylate~,
polyalphahydroxy acrylates, acrylic/maleic acid copolymers,
and acrylic phosphinates. Other polymers which are
20 especially preferred for use in liquid detergent
compositions are deflocculating polymers such as for example
disclosed in EP 346995.
The molecular weights of homopolymers and copolymers are
25 generally 1000 to 150,000, preferably 1500 to 100,000.
Polyacylate thickeners may well have molecular weights from
300,000 up to 6 million. The amount of any polymer may lie
in the range from 0.5 to 5% or even 10% by weight of the
composition.
For liquid formulations with a "gel" appearance and
rheology, particularly if a clear gel is desired, a
chlorine-stable polymeric thickener is particularly useful.
U.S. Patent No. 4,260,528 discloses natural gums and resins
for use in clear autodish detergents, which are not
chlorine-stable. Crosslinked acrylic acid polymers
manufactured by B.F. Goodrich and sold under the trade name
"Carbopol" have been found to be effective for production of
20~8230
14 C 7296 (R)
clear gels, and Carbopol g40 having a molecular weight of
about 4,000,000 is particularly preferred for maintaining
high viscosity with excellent chlorine stability over
extended periods. Further suitable chlorine-stable polymeric
5 thickeners are described in U.S. Patent 4,867,896.
The amount of thickener employed in the composition,
including any polymeric thickener, may range from 0 to 5%,
preferably 1 to 3%.
Stabilizers and/or co-structurants such as long-chain
calcium and sodium soaps and C12 to C18 alkyl sulphates are
detailed in U.S. Patents Nos. 3,956,158 and 4,271,030 and
the use of other metal salts of long-chain soaps is detailed
in U.S. Patent No. 4,752,409. The amount of stabilizer which
may be used in the liquid cleaning compositions is from
about 0.01 to about 5% by weign~ OL ~he co,.lpositlon,
preferably 0.1-2%. Such stabilizers are optional in gel
formulations. Co-structurants which are found especially
20 suitable for gels include trivalent metal ions at 0.01-4~ of
the composition and/or water-soluble structuring chelants at
1-60%. These co-structurants are more fully described in EP-
A-323209.
25 Defoamer
A significant consideration, in machine dishwashing
compositions, is the need to suppress foaming. The agitation
conditions in a dishwashing machine are more rigorous than
those in a fabric washing machine and lead to foam
formation. Some food residues, such as egg and cream, also
lead to the generation of foam.
Foam, if it forms, can cause air to be drawn into the
circulating pump. This can interfere with proper water
35 circulation and the supply of water to the heating element.
Excessive foam generation can eventually lead to air locking
of the pump, which could wreck the machine by stopping the
water supply to the heating element.
2~g~3~
C 7296 (R)
A composition of the invention may further include defoamer.
Even if the cleaning composition has only low foaming
surfactant, presence of a defoamer ean assist to minimize
foam which food soils ean generate.
Current maehine dishwashing eompositions contain a nonionic
surfaetant whieh includes ethylene oxide and propylene oxide
residues. These surfaetants have eloud points below the
operating temperature and they therefore form hydrophobie
10 droplets whieh exert an antifoam aetion.
Materials whieh may be utilised as defoamer in a eomposition
of this invention inelude mono- and di- C8 to C22 alkyl
phosphates and mineral oil/or wax. These may be used as a
15 eombination containing partieles of the insoluble alkyl
phosphate together with petroleum jelly. Possible
alternatives co ~he alk~l pl.ospnate lnclude ethylene
distearamide, ealcium soap and finely divided siliea,
espeeially hydrophobed siliea. Mineral oils and waxes whieh
20 may be used include petroleum fraetions, Fischer-Tropseh
waxes, ozokerite, eeresin montan wax, beeswax, candelilla
wax, camauba wax and mixtures thereof.
A further category of materials whieh may be used are
25 ketones of formula R7CoR8 wherein R7 and R8 are botn alkyl
or alkenyl groups eontaining 8 to 24 earbon atoms and sueh
that the ketone eontains 25 to 49 carbon atoms. Ketones of
this type and their use as antifoam agents in (other)
maehine dishwashing compositions, are diselosed in EP-A-
324339.
Another eategory of material whieh can be used as a defoameris soap or fatty acid whieh beeomes neutralised to soap in
use of the composition. Such soap or fatty aeid should have
an aeyl group of 12 to 22 earbon atoms, espeeially 14 to 18
earbon atoms. If soap or fatty acid is used as defoamer some
ealeium salt may deliberately be included in the
composition, thereby ensuring the presence of calcium ions
2~2~
16 C 7296 (R)
to form a calcium soap which exerts the antifoaming action.
If present, the composition may include 0.1 to 30% by weight
of defoamer, preferably other than nonionic surfactant. Non-
soap defoamer may be used at levels towards the lower end ofthis range, e.g. 0.1 to 10%, preferably 0.5 to 2% or 5%.
Soap or fatty acid can be used as defoamer, and if present
may be used in amounts from 0.1 to 30% by weight, especially
0.5 to 10%.
If the surfactant is alkyl sulphate alone, it may be
desirable to use a said ketone (in branched chain alcohol),
soap or fatty acid as the defoamer and to avoid alkyl
phosphates or mineral oil.
Minor amounts of various other components may be present in
the cleanlng com~osition. These include anti~scalant~,
corrosion-inhibitors anti-redeposition agents, anti-tarnish
agents, other enzymes (especially amylase and/or lipase at
0.05-2% by weight, preferably 0.5-1.5%) and other functional
additives and perfume.
As revealed above the compositions of this invention may
take the form of a liquid or a gel.
The composition is preferably formulated to give a pH in the
range 7 to ~1, even better 8 to ll if added to deionized
water at a concentration of 2.0 gramsllitre. A particularly
preferred pH is 9.0 to 9.5.
The following examples will more fully illustrate the
embodiments of the invention. All parts, percenta~es and
proportions referred to herein and in the appended claims
are by weight unless otherwise indicated.
2~8~230
17 C 7296 (R)
Example_l
This example demonstrates action of removing soil from glass
slides.
5 New glass slides, 5cm x 5cm were machine washed, repeatedly
rinsed with demineralised water and soiled with about 55mg
baked on egg-yolk per slide.
All washing solutions contained, in 1 litre of 16 French
10 hardness water:
Sodium citrate dihydrate 0.445g
Acrylic-maleic copolymer
(Sokolan CP5) O.lllg
15 Sodium disilicate monohydrate* 0.445g
Potassium coconut soap O.lOOg
Sodium sulphate dihydrate 0.950g
Calcium sulphate 0.03g
* SiO2:Na20 > 2.0
These materials were added to the water and stirred at 45C
for 15 minutes. Some solutions then received:-
30mg Savinase 6.OCM (sold as having 1500 GU/mg, analysed as1544 GU/mg) and/or
0.5g alkyl polyglycoside of formula RO(G)x where R = C12-C14
alkyl, G denotes a glucose residue and x has an average
value of 1.3.
I'he solutions were maintained at 45C.
After one minute slides were placed in the solution. Slides
were removed after varying periods of time, dried and
35 weighed to determine stain removal. The quantity removed was
expressed as a percentage of the original stain.
Results were as follows:-
2~8~23~
18 C 7296 (R)
% Egg-yolk removal
Wash TimeNo enzyme Enzyme APGAPG+Enzyme
(minutes) No APG only only
% % %
5 1 1.7 1.5 0.8 1.2
1.5 ~.0 O.g 1.7
1.9 3.1 0.4 4.4
2.0 4.4 -0.2 15.2
2.4 5.8 0.2 22.4
10 40 2.6 8.1 -0.6 31.3
2.5 12.8 -1.1 48.1
2.6 20.1 -1.4 70.6
These results show synergistic enhancement of stain removal
15 through the use of APG jointly with the proteolytic enzyme,
with washing periods of 10 minutes or longer.
Example 2
The procedure was similar to Example 1. All solutions
20 contained, per litre of water:-
Sodium citrate dihydrate 0.60g
Acrylic maleic copolymer 0.15g
Sodium disilicate monohydrate 0.60g
Some solutions received 0.5g of alkyl polyglycoside and/or
3Omg of Savinase (both as used in Example 1). Further
solutions received 0.5g of C13 to C15 alcohol 3EO
(Synperonic A3) and/or 30mg Savinase. Slides were maintained
in the solution at 45C for 60 minutes.
Results were:-
Solution contained wt% egg-yolk removal
Savinase only 24.3 + 4.5
APG only 0.7 + 0.6
Synperonic A3 only 3.0 + 1.1
APG + Savinase 53.0 + 8.0
40 Synp.A3 + Savinase 26.3 + 14.5
Clearly synergy with APG exceeded synergy (if any~ with
Synperonic A3.
20~823~
19 c 7296 (R)
Example 3
The procedure was the same as in Example 2. All solutions
contained in 1 litre water:-
Sodium tripolyphosphate 1.16g
Sodium carbonate 0.27g
Sodium disilicate hydrate 0.32g
Some solutions received 0.5g of alkyl polyglycoside and/or
30mg of Savinase (both as used in Example 1). Furthersolutions received 0.5g of C13 to C15 alcohol 3EO
(Synperonic A3) and/or 30mg Savinase. Slides were maintained
in the solution at 45C for 60 minutes.
15 Results were:-
Solution contained Egg-yolk removal (wt%)
Sa-vi.as~ 15.8 + 6.3
20 APG 3.6 + 1.6
Synperonic A3 5.3 + 2.0
AP5 + Savinase 42.5 + 15.1
A3 + Savinase 14.4 + 1.6
25 Again, APG plus Savinase gave the best soil removal.
Example 4
The procedure was similar to Example 1. Several types of
30 alkyl polyglyc:oside were employed. All solutions contained,
per litre of water:-
Sodium citrate dihydrate 0.60g
Acrylic maleic copolymer 0.15g
35 Sodium disilicate monohydrate 0.60g
Alcalase 2.OT 30mg (giving activity 46
GU/ml of solution).
All solutions received 0.5g of alkyl polyglycoside of
general formula RO(G)x where G denotes a glucose residue and
40 R is an alkyl chain. The alkyl polyglycoside displayedvarious alkyl chain lengths R and various values of x, the
degree of polymerisation.
2~8~30
C 7296 (X)
Slides were maintained in the solutions at 45C for 40
minutes. The alkyl polyglycoside eharacteristics and the
results obtained were:-
5 No of carbon atoms Degree ofwt% egg-yolk
in alkyl ehain ~ polymerisation removal
9-11 1.4 86.6 + 4.6
9-11 1.8 79.7 ~ 9.2
12-13 1.8 54.1 + 4.6
14 1.4 43.3 + 5.4
12-14 * 1.3 *58.0 + 5.2
10-12 1.3 86.0 * 4.5
* Same as used in Examples 1 to 3.
15 Example 5
Again the proeedure was similar to Example 1. The detergent
active used was ethyl 6-O-decanoyl glucoside whieh has the
formula
o
9H19C ~o
I OH - OC2H5
O~l
All solutions eontained, per litre of water:-
35 Sodium eitrate dihydrate 0.60g
Aerylie maleie eopolymer 0.15g
Sodium disilicate monohydrate 0.60g
Some solutions also contained:-
30mg Alcalase 2.0T (giving an activity of 46 GU/ml) and/or
0.5g ethyl 6-O-decanoyl glucoside
The solutions were used to wash glass slides stained with
45 egg-yolk as in Example 1, or stainless steel slides stained
with egg-yolk in the same way.
2~8~23~
21 C 7296 (R)
Slides were maintained in the solutions at 45C, removed
after varying periods of time, dried and weighed to assess
stain removal, as in Example 1.
5 Results were as follows:-
% Egg yolk removal from glass
Wash time enzyme only Glucoside Enzyme
(minutes) only + glucoside
10 10 4 + l - 2 + 1 4 + 1
9 + O O + 1 17 + 8
15 + 1 1 + 1 34 ~ 11
27 + 3 1 ~ 1 53 + 17
% Egg yolk removal from stainless steel
Wash time enzyme onlyGlucoside Enzyme
(minutes) only + glucoside
4 + 0 2 + 0 4 + O
20 20 8 + 1 _ ~ L ~
16 + 1 2 + 1 34 -~ 7
25 -~ 4 2 + 0 54 + 11
The use of enzyme and glucoside together is thus seen to
25 give a synergistic enhancement of stain removal.
Exam~le 6
A machine dishwashing formulation was a mixture containing:
Amount by Percent by
weight wei~ht
Na-citrate dihydrate 2.67g 18.5%
Acrylic-maleic copolymer
(Sokolan CP5) 0.67g 4.6%
Na-disilicate monohydrate 2.67g 18.5%
35 Oleic acid 3.44g 23.8%
Ca-stearate 0.30g 2.1%
Petroleum j211y 1. 20g 8.3%
APG 3.00g 20.7%
Savinase 6.OCM (1544 GU/mg) 0.30g 2.1%
40 Termamyl 60T (4.8MU/mg)0.20g 1.4%
The alkyl polyglycoside was of the formula RO(G)x where G
denotes glucose, R is a C12-C14 alkyl chain and x averages
1.8. This formulation was used to wash various stained glass
45 slides using a ~osch S510 automatic dishwasher on its
standard program and without salt added to the machine. The
~$~3~
22 C 7296 (R)
main wash temperature was 55C, the final rinse temperature
was 65C. The water used tap water of 16 French Hardness.
The glass slides were stained with potato, a custard pudding
or egg yolk. The potato and custard pudding stains were aged
at 30C and 60~ relative humidity for 16-24 hours. The egg
yolk stain was baked-on at 120C for two hours. Removal of
the stain was determined as loss in weight.
10 The extent of stain removal was:
Potato 99-7
Custard pudding 92.1
Egg yolk 54.0
Example 7
This example demonstrates synergistic action in removing
soil Lrom glass Sll~tS.
20 New glass slides, 5cm x 5cm were machine washed, repeatedly
rinsed with demineralised water and soiled with about 55mg
baked on egg-yolk per slide.
All washing solutions contained, in 1 litre of 16 French
25 hardness water:-
Sodium citrate dihydrate 0.6 g
Acrylic-maleic copolymer
(Sokolan CP5) 0.15 g
30 Sodium disilicate monohydrate 0.6 g
These materials were added to the water and stirred at 45C
for 15 minutes. The solutions then received:-
20mg Alcalase 2.OT (providing 30GU/ml in solution)and/or 0.25g sodium dodecyl sulphate (SDS).
208~
23 C 7296 (R)
The solutions were maintained at 45C.
After one minute slides were placed in the solution. Slides
were removed after varying periods of time, dried and
5 weighed to determine stain removal. The quantity removed was
expressed as a percentage of the original stain. In this
Example only, when a slide was removed from the washing
solution it was replaced with a similarly soiled slide which
had received identical treatment in a second, identical wash
solution.
Results were as follows:-
wt% Egg-yolk removal
15 Wash Time Enzyme SDS SDS+Enzyme
(minutes) only only
% % %
1.3 -1.1 0.0
2.3 -1.0 6.5
20 30 2.1 -1.2 13.5
3.0 -3.3 23.8
These results show synergistic enhancement of stain removal
through the use of SDS -jointly with the proteolytic enzyme,
25 with washing periods of 20 minutes or longer.
Example 8
Example 7 was repeated, using a larger amount of enzyme and
a larger amount of a different anionic surfactant. When
2~882~
24 C 7296 (R)
slides were removed from the wash solution they were
replaced with a clean slide. In consequence the washing
solutions received:
30mg Alcalase 2.0T (providing 45 GU/ml in solution) and/or
0.5g of Texin ES68 which is a fatty acid ester sulphonate of
formula
R2CHCO2R
S03Na
in which R2 is derived from tallow and so is predominantly
C16 and C18 alkyl and R3 is methyl.
The results were:
wt% Egg-yolk removal
Wash TimeEnzyme FAES FAES+Enzyme
(minutes) only only
6 4 16
13 44
20 30 19 16 68
26 21 81
The synergistic improvement when using FAES and enzyme
together is apparent.
When this experiment was repeated using stainless steel
slides the results were almost identical.
Example 9
30 The procedure of Example 7 was repeated using SDS, and
~o~3~
c 7296 (R)
mixtures of SDS with equal weights of other surfactants. For
each test the same total amount of surfactant (250mg/l) was
used, and 2Omg/l of Alcalase 2.OT was present.
5 The results, expressed as wt% egg-yolk removal after 30
minutes were:
Surfactant wt% egg-yolk removal
SDS 66 + 13
10 SDS + Dobanol 91-6 69 + 11
SDS + Synperonic A7 53 + 9
SDS + APG 300 59 + 15
Dobanol 91-6 is an ethoxylated fatty alcohol where the fatty
15 alcohol has chain length 9 to 11 carbon atoms and the
average degree of ethoxylation is 6. It has an HLB value of
12.5
Synperonic A7 is an ethoxylated fatty alcohol where the
fatty alcohol has chain length 13 to 15 carbon atoms and the
average number of ethylene oxide residues is 7. It has an
HLB value of 12.2.
APG 300 is an alkyl polyglycoside of formula
R50(G)~
where R5 is alkyl of 9 to 11 carbon atoms and x has average
value of 1.4.
208823Q
26 C 7296 (R)
Example 10
Example 7 was repeated using each of three nonionic
surfactants in place of SDS. The results, expressed as wt%
egg-yol~ removal after 30 minutes, were:
wt% egg-yolk removal
Synperonic A3 + enzyme 15 + 3
Synperonic A7 + enzyme 33 + 6
Dobanol 91-6 + enzyme 53 + lO
Synperonic A3 is C13-C15 fatty alcohol ethoxylated with an
average of 3 ethylene oxide residues. It has HLB value 7.9.
Synperonlc A~ lS, as mentioned in the last example, C13-C15
alcohol with an average of 7 ethylene oxide residues. HLB
15 value is 12.2.
Dobanol 91-6 is a Cg-Cll alcohol with an average of 6
ethylene oxide residues. HLB value is 12.5.
It can be seen that this nonionic, used alone, was much
20 superior to Synperonic A7, used alone.
Example 11
Example 7 was repeated twice using a larger amount of enzyme
(as in Example 8) and two ethoxylated nonionic surfactants.
In consequence the washing solutions received:
30mg A].calase 2.0T (providing 45 GU/ml in solution) and/or
0.4g of either Synperonic A7 or Dobanol 91-6.
2~23~
27 C 7296 (R)
Results, expressed as wt% egg-yolk removal after 30 minutes,
were:
wt% egg-yolk removal
5 Synperonic A7 Dobanol 91-6
enzyme only18.9 + 6.0 17.1 + 4.1
surfactant only8.4 + 2.7 7.4 + 5.2
surfactant + enzyme46.5 + 7.3 70.5 + 7.5
10 This confirms the greater synergy wlth Dobanol 91-6.
Example 12
Example 7 was repeated using a larger amount o~ enzyl~le ~a~
in Examples 8 and 11~ and two anionic surfactants. In
consequence the washing solutions received:
30mg Alcalase 2.0T (providing ~5 GU/ml in solution) and/or
250mg of either Empicol LX or 250 mg/litre of either sodium
lauryl ether s,ulphate (LES) with average 3 ethylene oxide
20 residues, or middle cut coconut alkyl sulphate (Empicol LX).
Results, expressed as wt% egg-yolk removal after 30 minutes,
were:
wt% egg-yolk removal
25 enzyme only 3 7 + 0.4
Empicol LX only-2.0 + 0.2
Empicol LX -~ enzyme35.2 + 2.5
LES only 0.1 + 0.7
LES + enzyme31.2 + 2.6
2~8~23~
28 C 7296 (R)
,Example 13
Several machine dishwashing formulations were prepared. Each
was a mixture containing:
Amount by weight
Na-citrate dihydrate 3.0g
Acrylic-maleic copolymer
(Sokolan CP5) 0.75g
Na-disilicate monohydrate 3.0g
10 Sodium perborate monohydrate 1.16g
TAED granules (80% active) 0.72g
Oleic acid 0.20g
Alcalase 2.0T (23GU/m~! n.o75g
Termamyl 6.0 CM 0.20g
Termamyl is an amylase.
The formulations contained sodium dodecyl sulphate in
amounts which were 0.75g, 1.5g and 3.0g.
Each formulat:ion was used to wash various stained glass
slides using a Bosch S510 automatic dishwasher on its
standard program and without salt added to the machine. The
main wash temperature was 55C, the final rinse temperature
25 was 65C. The water used was tap water of 16 French
Hardness.
The materials from which the various slides were made, the
stains on them and the extent of removal are set out in the
2Q~8230
29 C 7296 (R)
following table. In most instances the extent of removal was
determined by weight loss. In a few instances the extent of
removal was determined by visual inspection of the area
which remains covered by the stain.
In addition the pressure delivered by the pump of the
machine was monitored. This is a measure of the
effectiveness of the defoamer, in that foaming leads to loss
of pump pressure.
The results are set out in the following table. All of the
wash solutions formed in the machine had a pH of 9.5.
Stain Slide wt% egq-yolk removal
0.75g SDS1.50g SDS3.00~ SDS
egg-yolk stainless steel 92 + 9100 + 1 99 + 2
egg-yolk porcelain 92 + 10 95 + 0100 ~ 0
custard pudding
stainless steel 60 + 2633 + 10 38 + 16
custard pudding
porcelain82 + 13 73 + 1278 + 14
potato stainless steel * 97 + 4 100 + 1 100 + 0
potato porcelain * 85 + 11 86 + 1093 + 10
25 spinach porcelain * 100 + 0100 + 0100 + 0
Average pump pressure 90% 79% 70%
* denotes visual score
2~230
~ 7296 (R)
Example 14
A composition containing Dehypon KE 2429 foam inhibitor
(believed to be a mixture of branched chain alcohol and
ketone according to EP-A-324,339) was used to wash a
stainless steel plate 20cm x 6cm with almost 0.8g baked-on
egg-yolk, in a Bosch 5510 machine. The wash conditions were
the same as for Example 12. The composition contained:
Sodium citrate dihydrate 5.0g
Sodium dodecyl sulphate 1.25g
Alcalase 2.0T 0.20g
Dehypon KE2429 0.50g
Removal of soil, determined as loss in weight, was 83%.
15 Average pump pressure was 73~ of pressure achieved with
water only and no load in the machine.
Example 15
Example 14 was repeated while also including 0.50g oleic
20 acid in the composition.
Removal of soil, determined as loss in weight, was 91%.
Average pump pressure was 100% of the pressure achieved with
water only and no load in the machine.
Exam~le 16
Several machine dishwashing formulations were prepared. Each
was a mixture containing:
208~3~
31 C 7296 (R)
Amount by weight
Na-citrate dihydrate 3.0g
Acrylic-maleic copolymer
(Sokolan CP5) 0.75g
5 Na-disilicate monohydrate 3.0g
Sodium dodecyl sulphate 2.5g
Oleic acid 0.17g
Ca-stearate/wax mixture 0.08g
Termamyl 6.OCM 0.20g
Various proteases were includes in these formulations which
were then used to wash porcelain and stainless steel slides
stained with baked-on egg-yolk. The r~clllts, which are
determined by loss in weight, are set out in the following
15 table.
Activity in
Proteasesolution wt% egg-yolk removal
steel porcelaln
20 Savinase 6.OCM 45GU/ml 68~ 8 66+ 9
Esperase 2.0T 40GU/ml 70+11 74+15
Alcalase CMl.5 45GU/ml 90+ 6 91+ 6
All of the active/protease combinations are compatible with
amylases.
