Note: Descriptions are shown in the official language in which they were submitted.
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
Technical 1?ielc~
The present invention relates to general purpose, hard
surface, liquid cleaning compositions comprising nonionic
surfactants and polymeric components.
Compositions for cleaning hard surfaces generally comprise one
or more nonionic surfactants as cleaning agents involved in
the removal of soil from the surface. Nonionic surfactants
have far better fatty soil detergency than charged surfactants
and are typically used in general purpose cleaning
compositions for hard surfaces such as kitchen worktops,
bathroom fittings, floors and the like.
A broad range of nonionic surfactants are known and used in
cleaning compositions. For example, these surfactants
typically comprise alkoxylated alcohols described as compounds
produced by the condensation of alkylene oxide groups, which
are hydrophilic in nature, with an organic hydrophobic
compound which may be aliphatic or alkyl aromatic in nature.
The length of the hydrophilic or polyaxyalkylene radical which
is condensed with any particular hydrophobic group can be
readily adjusted to yield a water-soluble compound having the
desired degree of balance between hydrophilic and hydrophobic
elements. Particular examples include the condensation
product of aliphatic alcohols having from 8 to 22 carbon atoms
in either straight or branched chain configuration with
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 2 -
ethylene oxide, such as a coconut oil ethylene oxide
condensate having from 2 to 15 moles of ethylene oxide per
mole of coconut alcohol; alternatives include condensates of
alkylphenols whose alkyl group contains from 6 to 12 carbon
atoms with 5 to 25 moles of ethylene oxide per mole of
alkylphenol.
It is known to incorporate components into a nonionic
surfactant-based composition with the intention that
deposition of such components onto surfaces will provide a
protective layer against soiling in a one step cleaning
operation. Our published application WO 94/26858 discloses
how certain anionic polymers can be used, together with
nonionic surfactants, both to improve initial cleaning and to
prevent soil redeposition on hard surfaces which have been
cleaned with compositions comprising these polymers. It is
believed that the polymer not only improves the initial
detergency of the formulation but is also deposited on the
surface during the cleaning process, leaving a protective film
which either prevents soil adhesion or assists in soil
removal. In addition to the anionic polymers it is known to
deposit silicone materials and fluorosurfactants so as to
achieve the same end.
WO 94/26858 discloses how cleaning compositions which deposit
a protective film of polymer may be prepared at acid pH's. As
is noted in WO 94/26858, the benefit of these polymers was
lost as the pH of the prior products was increased.
Furthermore, one recognised difficulty with acid products is
that they have the potential to damage certain surfaces,
particularly enamels such as those used on baths. It is also
preferred that cleaning compositions should be formulated at
high pH so as to give particularly good fatty soil detergency.
It is therefore desirable to be able to formulate products
across the entire pH range 3-11 while maintaining the soil
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 3 -
release and low effort cleaning benefits outlined in the above
mentioned case.
Brief Descrifltion of the Invention
We have now determined that the presence of cationic
surfactant enables the pH of nonionic and polymer containing
products to be increased, without the loss of the benefits due
to polymers. While it is believed that this enables the
difficulties associated with low pH formulations to be
overcome the incorporation of cationic surfactants has
additional advantages as set out below.
Accordingly the invention provides a hard surface cleaning
composition of 'pH 3-12 comprising:
a) 1-30~ nonionic surfactant,
b) 0.005-5~ c~f a water soluble, anionic polymer having an
average molecular weight of less than 1000000, said
polymer being free of quaternazy nitrogen groups,
wherein, the ratio of polymer: nonionic is 0.1:1 or less,
and,
c) 0.005-5~ of a cationic surfactant.
A further aspect of the present invention relates to a method
for cleaning hard surfaces which comprises the step of
treating the surface with a cleaning composition of pH 3-12
comprising:
a) 1-30~ noni.onic surfactant,
CA 02280877 1999-08-12
WO 98/40452 PC1'/EP98/01273
- 4 -
b) 0.005-5~ of a water soluble, anionic polymer having an
average molecular weight of less than 1000000, said
polymer being free of quaternary nitrogen groups,
wherein, the ratio of polymer: nonionic is 0.1:1 or less,
and,
c) 0.005-5~ of a cationic surfactant.
Without wishing to limit the present invention by reference to
any theory of operation it is believed that enhanced
detergency of nonionic surfactants, at acid pH, in the
presence of polymer is due to the formation of a hydrogen
bonded complex between the nonionic surfactant and the
uncharged, undissociated carboxylic acid groups of the
polymer. As the pH is raised, the acid groups of the polymer
dissociate and the hydrogen-bonded complex is no longer
formed. It is believed that in the presence of the cationic
surfactant required by the present invention, negatively
charged (i.e. carboxylic dissociated) polymer can interact
with the cationic surfactant and the nonionic surfactant to
form a three-component complex which deposit the nonionic
surfactant upon the soil and/or surface being cleaned. While
the mechanism is not entirely clear, this may possibly be due
to the interaction of the charged polymer with mixed miscelles
of cationic and nonionic surfactant.
It is believed that the deposition of the complex on the
surface has two results. Firstly the concentration of the
surfactant at the surface is increased, resulting in improved
cleaning in the initial cleaning cycle and a reduction in the
so-called primary cleaning effort. It is also believed that -
the complex, or at least some part of it, remains on the
surface after cleaning and prevents or reduces the re- -
attachment of soil to the surface thereby making the surface
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 5 -
easier to clean in second and subsequent cleaning cycles, i.e.
it reduces the ''secondary' cleaning effort.
The presence of a cationic surfactant in the compositions of
the invention can also provide an antimicrobial effect during
primary cleaning where the cationic is antimicrobial. Using
compositions according to the invention it is possible to
achieve a log 5 reduction in populations of bacteria.
Surprisingly, wE~ have determined that compositions according
to the invention which contain antimicrobial cationic
surfactants show longer lasting hygiene on surfaces which have
been treated with the compositions and can maintain the
antimicrobial effect even after the surfaces have been rinsed.
This is believed to be due in part to the retention of
antimicrobial components of the formulation at the surface and
may be due in part to the formulation preventing re-adhesion
of microbes on t;he surface.
Accordingly, a third aspect of the present invention relates
to the use, in a surface cleaning composition comprising
nonionic surfactant and an antimicrobial cationic surfactant,
of a water soluble, anionic polymer having an average
molecular weighi~ of less than 1000000, said polymer being free
of quaternary nitrogen groups, to prolong the antimicrobial
effectiveness o:E the antimicrobial cationic surfactant on said
surface.
As will be expl<~ined in further detail below, the compositions
of the invention can comprise other benefit components which
become deposited at the surface during a cleaning operation
performed with ouch a composition.
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 6 -
Various preferred and essential features of the invention are
described in further detail below.
The water soluble polymer is an essential component of the
compositions according to the present invention.
As noted above the polymers according to the invention are
water soluble polymers having an average molecular weight of
less than 1000000, and being free of quaternary nitrogen
groups. Typically, these polymers are polymers bearing
carboxylate functional groups although the use of other
anionic polymers is not excluded. In the context of the
present invention, anionic polymers are those which carry a
negative charge or similar polymers in protonated form.
Mixtures of polymers can be employed.
The preferred polymers in embodiments of the present invention
are those which are readily available in the marketplace.
These are polymers of acrylic or methacrylic acid or malefic
anhydride, or a co-polymer of one or more of the same either
together or with other monomers.
Particularly suitable polymers include polyacrylic acid,
polymaleic anhydride and copolymers of either of the
aforementioned with ethylene, styrene and methyl vinyl ether.
The most preferred polymers are malefic anhydride co-polymers,
preferably those formed with styrene, acrylic acid, methyl
vinyl ether and ethylene.
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
Preferably, the molecular weight of the polymer is at least,
5000, more preferably at least 50,000 and most preferably in
excess of 100,000. VERSICOL E-11 [RTM] (ex. Allied Colloids)
which is a polyacrylic acid, has been found to be a suitable
polymer for use in compositions according to the invention.
Typically, the surfactant based cleaning compositions comprise
at least O.Olwt'~ polymer, on product. The positive benefit of
the presence of polymer as regards the improvement in cleaning
properties can :be identified even when very low levels of
polymer and surfactant are present. This property of a low
concentration threshold is particularly advantageous in
applications of the invention where considerable dilution is
expected, such as in floor cleaning.
Preferably the level of polymer is 0.05-S.Owt~ at which level
the anti-resailing benefits become particularly significant.
More preferably 0.2-2.Owt~ of polymer is present. We have
determined that higher levels of polymer do not give
significant further cleaning advantages with common dilution
factors, while increasing the cost of compositions. It is
believed that high levels of polymer increase the viscosity of
the product and. hinder product wetting and penetration of the
soil. However, for concentrated products which are
significantly dliluted prior to use, the initial polymer level
can be as high as 5$wt.
As mentioned ax>ove, the molecular weight of the polymer is
preferably belt>w 1 000 000 Dalton. It is believed that as the
molecular weight increases the cleaning benefit of the polymer
- is reduced.
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
_ g _
It is essential that compositions according to the present
invention comprise at least one nonionic surfactant.
The composition according to the invention comprise detergent
actives which can be chosen from commercially available
nonionic detergent actives. Suitable nonionic detergent
active compounds can be broadly described as compounds
produced by the condensation of alkylene oxide groups, which
are hydrophilic in nature, with an organic hydrophobic
compound which may be aliphatic or alkyl aromatic in nature.
Alkoxylated alkanols are particularly preferred.
The length of the hydrophilic or polyoxyalkylene radical which
is condensed with any particular hydrophobic group can be
readily adjusted to yield a water-soluble compound having the
desired degree of balance between hydrophilic and hydrophobic
elements. In general, the compounds will be alkoxylated
alcohols having C8-C22 alkyl chains and 1-20 molar equivalents
of ethylene oxide and/or propylene oxide residues attached
thereto.
Particular examples include the condensation product of
aliphatic alcohols having from 8 to 18 carbon atoms in either
straight or branched chain configuration with 2-15 moles of
ethylene oxide. Examples of such materials include a coconut
oil ethylene oxide condensate having from 2 to 15 moles of
ethylene oxide per mole of coconut alcohol; condensates of
alkylphenols whose alkyl group contains from 6 to 12 carbon
atoms with 5 to 25 moles of ethylene oxide per mole of
alkylphenol. -
The preferred nonionic surfactants are the condensation
products of 9-15 carbon alcohols with 3-10 moles of ethylene
oxide. In embodiments of the invention we have found that
CA 02280877 1999-08-12
WO 98/40452 PGT/EP98/01273
_ g _
DOBANOL [RTM] series ethoxylated alcohol nonionic surfactants
(ex. Shell) are suitable. Preferred materials include DOBANOL
91-5 [TM) (C9-C11 alkyl, 5 EO alkyl ethoxylate ex. Shell) and
DOBANOL 91-8 (TM] (C9-C11 alkyl, 8 EO alkyl ethoxylate ex.
Shell).
It is possible to use mixtures of nonionic surfactants. As
will be described in more detail below these mixed systems
have some advantages in antifoaming the products.
Alternative nonionic surfactant materials which are envisaged
include condensates of the reaction product of ethylenediamine
and propylene oxide with ethylene oxide, the condensates
containing from 40 to 80~ of polyoxyethylene radicals by
weight and having a molecular weight of from 5,000 to 11,000;
tertiary amine oxides of structure R3N0, where one group R is
an alkyl group of 8 to 18 carbon atoms and the others are each
methyl, ethyl or hydroxy-ethyl groups, for instance
dimethyldodecylamine oxide; tertiary phosphine oxides of
structure R3P0, where one group R is an alkyl group of from 10
to 18 carbon atoms, and the others are each alkyl or
hydroxyalkyl groups of 1 to 3 carbon atoms, for instance
dimethyldodecylphosphine oxide; and dialkyl sulphoxides of
structure RZSO where the group R is an alkyl group of from 10
to 18 carbon atoms and the other is methyl or ethyl, for
instance methyltetradecyl sulphoxide; fatty acid
alkylolamides; alkylene oxide condensates of fatty acid
alkylolamides a:nd alkyl mercaptans. In addition, it is
believed that alkyl polyglycoside surfactants can be employed
as the nonionic surfactant.
The amount of nonionic detergent active to be employed in the
composition of the invention will generally be from 1 to
30~wt, preferably from 3 to l5~wt. Levels of above 15~ active
show little increase in neat-use cleaning performance,
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 10 -
although such higher levels can be employed in products
intended to be considerably diluted prior to use. Typical
compositions will comprise 5-l0~wt nonionic active on product.
Anionic surfactant can be present in relatively small
proportions, however it is preferable that anionic surfactant
is absent from composition. As described in further detail
below small amounts of anionic detergents may be present in
the form of soaps as part of an antifoam system. It is
preferred that the compositions of the invention comprise less
than 2~wt, preferably less than 1~ of anionic surfactant.
Typically the cationic surfactants are materials of the
general formula RlRzR3R4N+X-, wherein all of the radicals are
hydrocarbons with or without hydroxy substitution, at least
one of the radicals R1-R4 is a C6-C22 alkyl, alkaryl or
hydroxyalkyl, at least one of the radicals R1-R4 is a C1-C4
alkyl or hydroxy alkyl and X is a monovalent anion equivalent.
The cationic surfactants are preferably, quaternary nitrogen
2 0 compounds of the general formula R1RZR3R4N'X-, where R1 and R2
are the same or different C1-C4 alkyl or hydroxy alkyl, R3 is
a C6-C22 alkyl, alkaryl or hydroxyalkyl, R4 is a C1-C22 alkyl,
alkaryl or hydroxyalkyl and X is a monovalent anion
equivalent.
Preferably X is a halogen, most preferably chloride or
bromide.
Preferably R1 and R2 are methyl. In embodiments of the
invention R3 is preferably C8-C18 alkyl, more preferably C10-
C16 alkyl. In embodiments of the invention R4 is preferably -
methyl, C8-C18 alkyl or benzyl. Thus, the cationic
surfactants used can have three 'short chain' radicals such as
methyl and one fatty-soluble 'long chain' radical or two
'short' chains and two fatty-soluble 'long chains', wherein
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98101273
- 11 -
the 'long chains' can be either linear or branched
hydrocarbons or contain aromatic rings.
A further advantage of including a cationic surfactant in the
compositions of: the invention is that preferred cationic
surfactants confer antimicrobial properties on the
formulation. :surprisingly, we have determined that
compositions according to the invention which contain
antimicrobial c:ationic surfactants show longer lasting hygiene
on surfaces which have been treated with the compositions.
Particularly suitable cationic detergent-active compounds
include cetylti:imethyl amanonium bromide (CTAB), hardened di-
tallow di-methyl ammonium chloride (available in the
marketplace as BARDAC 2250), benzalkonium chloride and
mixtures thereof.
The cationic surfactants which comprise one aryl substituent
are especially preferred as they are believed to give
particularly good antimicrobial effects.
Typical levels of cationic surfactant will lie in the range
of 0.05-3~wt on product. Preferred levels of cationic
surfactant are around 1-3~wt.
The total amount of detergent active compound to be employed
in the detergent composition of the invention will generally
be from 1.5 to 30~, preferably from 2 to 20~ by weight, most
preferably from 5-20wt~.
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 12 -
Solvents may be present in the compositions of the invention.
It is preferred that the compositions of the present invention
comprise not more than 2~wt of solvents of the general
formula:
Rl- 0 - ( E 0 ) m- ( PO ) n-R2 ,
wherein R1 and RZ are independently C2-6 alkyl or H, but not
both hydrogen, m and n are independently 0-5. It is believed
that the use of polymers in compositions according to the
present invention can offset the otherwise deleterious effects
of any solvent which is present when the product is used on
certain plastics materials.
More preferably, no more than 2$wt of solvent selected from
the group comprising di-ethylene glycol mono n-butyl ether,
mono-ethylene glycol mono n-butyl ether, propylene glycol n-
butyl ether and mixtures thereof is present. Advantageously,
effectively no solvent other than water is present.
Fetal ion binding agents
Preferably the composition contain either detergent builders
or non-building metal ion sequesterants, collectively these
are known as metal ion binding agents.
Suitable metal ion binding agents include nitrilotriacetates, -
polycarboxylates, citrates, dicarboxylic acids, water-soluble
phosphates especially polyphosphates, mixtures of ortho- and
pyrophosphate, zeolites and mixtures thereof. Such agents can
additionally function as abrasives if present in an amount in
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98101273
- 13 -
excess of their solubility in water as explained herein. In
general, where the metal ion binding agent is a builder it
will preferably will form from 0.05 to 25~ by weight of the
composition.
Metal ion binding agents such as ethylenediaminetetraacetates
(e.g. EDTA), amino-polyphosphonates (e.g. those available as
the 'DEQUEST' (TM) series of materials) and phosphates and a
wide variety o:f other poly-functional organic acids and salts
(including materials such as methyl glycine diacetate (MGDA)),
can also optionally be employed.
A particular, further advantage of including metal ion binding
agents, preferably organic acetates, more preferably MGDA or
EDTA is believed to be that the microbiocidal properties of
the cationic surfactants are improved especially against Gram-
negative bacteria particularly under hard water conditions.
Preferred levels of metal ion binding agents are 0.05-5~wt,
preferably 0.1-3.O~wt, most preferably 1.5-3~wt. In preferred
compositions containing around 2~ cationic surfactant, 1.5-3~
of an organic acetate sequesterant will give a log five
reduction in viable bacteria even against recalcitrant
bacterial strains such as Pseudomomas aeruginosa.
Preferred compositions according to the invention contain 1.5-
3~wt of MGDA or EDTA.
In addition to the cleaning benefit we have determined that
the formulation containing polymer, alcohol, ethoxylate,
- cationic surfactant and sequestering agent has the additional
benefit that it reduces the adhesion of fungal and/or
bacterial spores to surfaces. This is described in further
detail below with reference to examples.
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 14 -
The composition according to the invention can contain other
ingredients which aid in their cleaning performance and
general utility.
Typically, a further optional ingredient for compositions
according to the invention is a suds regulating material,
which can be employed in compositions according to the
invention which have a tendency to produce excessive suds in
use. One example of a suds regulating material is soap.
Soaps are salts of fatty acids and include alkali metal soaps
such as the sodium, potassium, ammonium and alkanol ammonium
salts of higher fatty acids containing from about 8 to about
24 carbon atoms, and preferably from about 10 to about 20
carbon atoms. Particularly useful are the sodium and
potassium and mono-, di- and triethanolamine salts of the
mixtures of fatty acids derived from coconut oil and ground
nut oil. When employed, the amount of soap can form at least
0.005, preferably 0.5~ to 2~ by weight of the composition.
Further example of a suds regulating materials are organic
solvents, hydrophobic silicas, silicone oils and hydrocarbons.
An alternative suds regulating material comprises a mixed
EO/PO nonionic surfactant. Suitable ethoxylated/prapoxylated
nonionic detergents include the condensation product of
aliphatic alcohols having from 8 to 22 carbon atoms in either
straight or branched chain configuration with ethylene oxide
and propylene oxide, such as a coconut oil ethylene
oxide/propylene oxide condensate having from 2 to 15 moles in
total of ethylene oxide and propylene oxide per mole of
coconut alcohol. It is preferable that the mole ratio of
ethylene oxide to propylene oxide lies in the range 1:5-5:1.
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 15 -
Particularly preferred ethoxylated/propoxylated nonionics
include molecu7.es of the general formula:
r
R(EO)n(PO)mH
wherein: R is an alkyl residue having an average carbon chain
length of C8-C:14, preferably C9-C12, EO is an ethylene oxide
residue, n is 1.-10, PO is a propylene oxide residue and m is
1-5. A particularly preferred material is C9-11 5-8E0 1-3P0,
most preferably C9-11 6E0 2P0.
The amount of ethoxylated/propoxylated nonionic detergent
active to be employed in the composition of the invention will
generally be from 2 to l0~wt, and most preferably from 3-6~wt.
Preferred ratios of the ethoxylated to the
ethoxylated/prc>poxylated surfactant fall into the range 4:1-
2:1 with the et:hoxylated surfactant being present in weight
excess over the' ethoxylated/ propoxylated surfactant.
Compositions according to the invention can also contain, in
addition to the' ingredients already mentioned, other optional
ingredients such as pH regulants, sunscreens, colourants,
optical brighteners, soil suspending agents, enzymes,
compatible bleaching agents, gel-control agents, freeze-thaw
stabilisers, additional biocides, preservatives, detergent
hydrotropes, perfumes and opacifiers.
Hydrotropes, are useful optional components. It is believed
that the use of: hydrotropes enables the cloud point of the
_ compositions to be raised without requiring the addition of
anionic surfactants.
Suitable hydrot:ropes include, alkali metal toluene
sulphonates, urea, alkali metal xylene and cumene sulphonates,
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 16 -
short chain, preferably CZ-CS alcohols and glycols. Preferred
amongst these hydrotropes are the sulphonates, particularly
the cumene and toluene sulphonates.
Typical levels of hydrotrope range from 0-5~ for the
sulphonates. Correspondingly higher levels of urea and
alcohols are required. Hydrotropes are not generally required
for dilute products.
Given that the compositions of the invention effectively
comprise a means for deposition of a surfactant/polymer
complex at the surface being cleaned, it is envisaged that the
compositions of the invention can further comprise components
which it is desirable to deposit upon a surface. Three
preferred classes of additional components are perfumes, non-
cationic surfactant antimicrobial components and insect
repellents and/or insecticides.
Given that the compositions of the invention already comprise
a cationic surfactant and are alkaline, some antimicrobial
activity is already found in the compositions. Suitable
additional non-cationic non-surfactant antimicrobial
components are known in the art. Typical examples of this
class of materials includes antimicrobial perfume oils and oil
components.
Typical levels of the non-cationic antimicrobial agent in
formulations range from 0.01 to 8~, with levels of 0.05-4wt~,
particularly around 2~ being preferred for normal compositions
and up to two or four times that concentration being present
in so called, concentrated products. For sprayable products
the concentration of the antimicrobial agent will be in the
range 0.05-0.5$wt.
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 17 -
Particularly suitable insect repellents include essential oils
such as those of genus Mentha, particularly Mentha arvensis,
mentha piperita, Mentha spicata and Mentha cardica; Lemongrass
East Indian oil, Lemon oil, Citronella, Cedanvood and Pine
oil; terpenoids, particularly limonene, carvone, cineole,
linalool, Gum Camphor, citronellal, alpha and beta terpenol,
fencholic acid, borneol, iso borneol, bornyl acetate and iso
bornyl acetate. The most preferred insect repellants are the
terpenoids, particularly limonene. Of the above-mentioned
oils many are known to show antimicrobial effects as well as
being insect repellents and/or perfumes.
The level of insect repellent required will vary with the
nature of the material used. For essential oils and
terpenoids, preferred levels are 0.1-5~ on product.
It is preferable that the compositions of the present
invention are essentially free of abrasive particles.
The preferred pH of the neat products is 7-12 with a pH in the
range of 7-11 being more preferred and a pH of around 10-11
being particularly preferred so as to balance cleaning and
hygiene effectiveness.
Particularly preferred compositions according to the present
invention are mobile aqueous liquids, having a pH of 7-12
(preferably 7-11) which comprise:
a) 5-20~wt of a ethoxylated, 2-15E0, C8-C18 alcohol,
nonionic surfactant,
b) less than l~wt of anionic surfactants,
c) 0.2-2~wt of a water soluble, anionic polymer having an
average molecular weight less than 1,000,000, said
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 18 -
polymer being a polymer of at least one of acrylic acid,
methaczylic acid or malefic anhydride, with at least one
of acrylic acid, methacrylic acid, malefic anhydride,
ethylene, styrene and methyl vinyl ether, and ,
d) 0.05-5~wt (preferably 0.05-2$wt) of a cationic surfactant
which is a quaternary nitrogen compounds of the general
formula R1RZR3R9N'X-, where R1 and R2 are the same or
different C1-C4 alkyl or hydroxy alkyl, R3 is a C6-C22
alkyl, alkaryl or hydroxyalkyl, R4 is a Cl-C22 alkyl,
alkaryl or hydroxyalkyl and X is a monovalent anion
equivalent, and,
e) not more than 2~ of a solvent selected from the group
comprising di-ethylene glycol mono n-butyl ether, mono-
ethylene glycol mono n-butyl ether, propylene glycol n-
butyl ether and mixtures thereof.
More particularly preferred compositions according to the
invention are as described in the above paragraph but contain
a cationic surfactant which has antimicrobial properties (such
as benzalconium chloride) and a metal ion bing agent which is
an organic acetate. These compositions exhibit improved
primary and secondary cleaning at high pH as well as having
effective and persistent antimicrobial properties against a
broad range of microbes.
Compositions can be n~nufactured which comprise an essentially
dry powder and which form the compositions of the invention on
the addition of water.
In order that the present invention may be further understood
it will be described hereafter by way of the following non-
limiting examples.
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 19 -
In all the cleaning examples described below a specified level
(based on non-volatiles) of soil were deposited on an 'A4'
sized area of °DECAMEL' (RTM ex Formica) test surface by
spraying. The soil comprised 1~ glycerol tripalmitate, 0.5~
glycerol triolE~ate, 0.5~ kaolin, 0.2~ liquid paraffin, 0.1~
palmitic acid, 0.02 carbon black in methylated spirits. The
soil was allowESd to age for a specified time at room
temperature prior to cleaning. The initial effort required to
clean the surface is referred to below as the primary cleaning
effort.
44here secondary cleaning benefits were examined, in order to
investigate the' anti-resoiling performance, the DECAMEL sheets
were pretreated with the test composition and copiously rinsed
prior to soiling. The effort required to clean the re-soiled
surfaces is known as the secondary cleaning effort.
In both primanr and secondary cleaning the total effort used
to remove the soil from the test surface using a cellulosic
sponge cloth was measured using a rig fitted with force
measuring mean, to determine the total effort applied to the
surface. Due i~o variability in the experimental conditions,
in the data which follows results should not be compared
between series of experiments presented in different tables.
Formulations comprised nonionic surfactant and water with and
without polymer and with and without cationic surfactant.
The nonionic surfactants employed were DOBANOL 91-5 [TM] (C9-
C11 alkyl, 5 EO alkyl ethoxylate ex. Shell) and DOBANOL 91-8
[TM] (C9-C11 alkyl, 8 EO alkyl ethoxylate ex. Shell). The
polymers illustrative of the present invention were a
CA 02280877 1999-08-12
WO 98!40452 PCT/EP98/01273
- 20 -
polyacrylic acid (VERSICOL E11 [TM] ex Allied Colloids) which
had an average molecular weight of 250,000 Daltons. The
cationic surfactants used were C"-alkyl trimethyl ammonium
bromide (C~TAB: where n is 12,14 and 16), dicetyldimethyl and
tricetylmethyl ammonium bromides (DTAB and TTAB respectively).
The pH of the compositions was regulated with sodium hydroxide
or a carbonate/bicarbonate buffer system as indicated.
Example 1a-ld in Table 1 below show the primary cleaning
effort required using compositions which contained the
formulations given, on the soil given above, aged for a period
of two days after application of the soil at a coverage of
0 . 5mg / cm2 .
Table 1
la 1b is 1d
Dobanol 91-5 7~ 7~ 7~ 7~
Cetyl TAB - - 1$ 1~
Versicol E11 - 0.5~ - 0.5~
Carbonate/bicarbonate pH9 pH9 pH9
pH9
-Cleaning Effort (N/s) 1036 ~ 769 68 412
~
From table 1 it can be seen that the primary cleaning effort
is minimised at alkaline pH in the presence of both the
cationic surfactant and the polymer (example 1d), while higher
effort is required if either or both of these components is
absent (compare with comparative examples 1a, lb and lc). It
is believed that this is due to the formation of a
CA 02280877 1999-08-12
WO 98/40452 PG"f/EP98/01273
- 21 -
polymer/surfact.ant complex which increases the surfactant
concentration a.t the surface.
Table 2 below ~,hows the effect of the cationic type on primary
cleaning effort.. Experiments were performed on the soil given
above aged for a period of one day after application of the
soil at a coverage of 0.25mg/cni.
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 22 -
aP
Lf101 N
N oxo ap x ~r
r~ I 1 ,~ o t1,~r
0
N 1 N
dP dP x M
l~ I I e--i1 (7~c~
''
w
N as ao In x
I ~ 1 o p, vo
01 N
x
L~ W -1 I 1 G~,~-I
b
N
x o.
W -I 1 I O (~ M
o
U
O~ N
N ~ ~ ~ x
~ 1 I I ~
a~
,4 d~ 00
n a~ o
y x
1 1 1 o p, ,-1
N
x
L' I I I I ~
z
0
0o rl o ~1
1 r--I1~ W
w w
o -~1a
-~ o
0o c>aas m ~1 b
E
A v a x a
n n n ~ ~ ~ i ~ JI
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98101273
- 23 -
From table 2 it can be seen that compared with the control
(comparative example 2a) primary cleaning effort is in all
cases markedly :reduced by the combination of surfactant,
polymer and cationic (examples 2d, 2f and 2h) as compared with
systems in which only the cationic is added (comparative
examples 2c, 2e and 2g). Addition of the polymer alone, in
the absence of 'the cationic surfactant, (comparative example
2b) gives no si~~nificant reduction in primary cleaning effort
at this pH. It can be seen that of the different cationics
used the TTAB and CTAB materials give the lowest cleaning
effort.
Table 3 below further illustrates the effect of pH for
compositions which comprise 7~ Dobanol 91-5 and 0.5~ Versicol
E11 in the presence of differing levels of CTAB at the pH
indicated. pH was regulated with hydroxide and the
experiments were performed on the soil given above aged for a
period of one day after application of the soil at a coverage
of 0.25mg/cm2. Results are given in total primary effort to
clean in N/s.
Table 3
3a 3b 3c
pH pH6 pH8 pHlO
0~ CTAB 213 262 -
25~ CTAB 163 195 193
0.5~ CTAB 142 180 175
1~ CTAB 151 131 190
CA 02280877 1999-08-12
WO 98/40452 PGT/EP98/01273
- 24 -
From Table 3 it can be seen that through this pH range the
primary cleaning effort generally fails as the level of the
cationic surfactant level is increased.
Table 4 below provides additional data on the effect of pH for
compositions which comprise 8~ active in total and 0.5~
Versicol E11 in the presence of differing levels of CTAB (C)
and DTAB (D) at the pH indicated. The non-cationic active
material is Dobanol 91-5. pH was regulated with hydroxide and
the experiments were performed on the soil given above aged
for a period of one day after application of the soil at a
coverage of 0.25mg/ciri. Results are given in total primary
cleaning effort in N/s.
Table 4
4a 4b 4c 4d
pH pH4 pH7 pH4 pH7
type of cationic C C D D
0.00 cationic 162 749 162 749
0.13 cationic 171 399 171 308
0.25 cationic 188 288 173 227
0.50 cationic 190 403 162 269
From Table 4 it can be seen that compositions show poor
cleaning performance at the higher pH unless the cationic
surfactant is present. In the lower pH range (examples 4a and
4c) the effect disclosed in WO 94/26858 is believed to be
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 25 -
acting to reducEa the primazy cleaning effort requirement and
there is no significant effect of adding cationic (if anything
the compositions get slightly worse) although useful cleaning
results are still attained.
In the higher pFi range (examples 4b and 4d) it can be seen
that the addition of cationic surfactant significantly lowers
the cleaning efi_ort and enables the nonionic/polymer systems
to achieve similar results to those obtained in more acidic
products.
Table 5 below show the effect on the primary cleaning energy
effort requirement and the cloud point of modifying the
nonionic surfactant present. The compositions comprise 7~ of
a mixture of Dobanol 91-5 and Dobanol 91-8, 1~ CTAB and 0.5~
Versicol E11. ~f'Ihe table lists the percentage of Dobanol 91-8
in the nonionic portion of the surfactant mixture, the
remainder of the: mixture being the Dobanol 91-5.
Table 5
~ ~~obanol 91-8 Effort (N/s) Cloud Point
I
5a 0 331 30
5b 25 401 42.5
5c 50 479 53
5d 75 809 64
5e 100 876 75
CA 02280877 1999-08-12
WO 98J40452 PCT/EP98101273
- 26 -
From Table 5 it can be seen that the compositions which are
rich in the Dobanol 91-5 surfactant (for example 5a) give the
best reduction in primary cleaning effort, whereas while the
compositions which are rich in Dobanol 91-8 (for example 5e)
also give a useful reduction in primary cleaning effort this
is less marked than for the other surfactant. It is clear
from the table that the selection of an appropriate
combination of surfactants enables the cloud point of the
compositions to be controlled.
Table 6 below shows the effect on the secondary cleaning
effort requirement in subsequent cleaning cycles for the
compositions of the invention, using two different cationics.
The 'VARI' material is Varisoft 442-100P (TM: ex. Sherex-
Inlitco) a dihardened tallow dimethyl ammonium chloride.
Table 6
6a 6b 6c 6d
CTAB CTAB VARI VARI
primary recoiled primary recoiled
pH6 886 203 846 364
pH8 679 257 745 460
pHlO 969 426 958 602
pHl2 637 211 501 408
From Table 6 it can be seen that in all cases the surfaces
proved more easy to clean in the second cleaning cycle
(compare 6a with 6b and compare 6c with 6d). It is believed
CA 02280877 1999-08-12
WO 98/40452 PCTIEP98/01273
- 27 -
that this demonstrates that the one or more components of the
composition are being deposited on the surface and leaving a
residual film which either retards the attachment of soil or
aids in its removal, i.e. the secondary cleaning effort after
re-soiling of the surfaces is reduced.
The above examp7Les illustrate how the compositions of the
present invention enable a reduction of both primary and
secondary cleaning effort over a broad pH range.
Table 7: below :shows the result of a biocidal efficacy test
using the following bacteria (from the National Collection of
Type Cultures oi: American Type Culture Collection). Cultures
were maintained on beads in a cryopreservative at -80/C.
Staphylococcus ~3ureus NCTC 10788
Pseudomomas aeruginosa ATCC 15442
Saccharomyces cesrevisiae ATCC 9763
To prepare inocc:ulum a bead was removed from the storage vial
and aseptically transferred to 100m1 Nutrient Broth and
incubated at 37/C in a shaking waterbath for 24 hours
(bacteria). After incubation, the culture suspensions were
aseptically transferred into two 50m1 centrifuge tubes and
centrifuged at 21808 for 10 minutes (Mistral 1000, MSE) in
order to harvest: the cells. The supernatants were poured off
and the pellets resuspended in peptone diluent (0.1 percent
peptone and 0.8'_> percent sodium chloride, pH 7.0). The
suspensions were: kept at 4/C until needed, and before use in
the test were lE:ft on the bench at ambient temperature for at
least 30 minute:.
CA 02280877 1999-08-12
W0 98/40452 PCT/EP98/01273
- 28 -
The test used was a microtitre plate assay, which is
comparable to 'Method for the test for the antimicrobial
activity of disinfectants in food hygiene', more commonly
known as the European Suspension Test (EST). Bovine albumin
at a low level (0.03 percent) or a high level (0.3 percent)
was included in some of the tests. A 1/15 dilution of the
formulation was made in 'Water of Standard Hardness' as
referred to in the above method.
Microtitre plates (Bibby Sterilin, sterile 96-well, flat-
bottom) were prepared by adding 270m1 quenching solution in
row B of each plate and 270m1 peptone diluent into rows C-G.
The quench solution was composed of Tween 80 (3.0 percent),
lecithin (0.3 percent), L-histidine (0.1 percent), sodium
thiosulphate (0.5 percent) and 0.25N KHZPO9buffer (1 percent)
in sterile distilled water (1 litre). Sterile distilled water
or bovine albumin as appropriate (120m1) was added to the test
wells of row A. Then the formulation (150m1 1/I5 dilution)
was added to the appropriate test wells. The formulations
were randomised across the plates. The plates were placed on
a stainless steel 'plate incubator' tray attached to a
circulating waterbath, held at 20/C.
An aliquot of microbial suspension (30m1) was then added
simultaneously to all the wells of row A of the microtitre
plate using a multichannel pipette. The test mixture was left
at 20/C for a contact time of 5 minutes ~ 5 seconds, after
which time an aliquot (30m1) was transferred into row B
(quench), giving a 10-' dilution. After 5 t 1 min, an aliquot
(30m1) was transferred to row C (peptone diluent). Further
serial dilutions were performed in the same manner until row G
(10-6 dilution). The bacteria were enumerated using the Miles-
Misra technique. Three aliquots (10m1) from each dilution
were spotted onto pre-dried Tryptone Soya Agar plates which
had been divided into 6 sectors. The spots were allowed to
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 29 -
dry and the plates incubated at 37/C for 24 hours. Plates
were counted by selecting a dilution segment with 3-50 cfu per
spot and the average of the 3 spots was calculated. The
decadic logaritlun of this number was calculated and subtracted
from the decadic logarithm of the initial count to give the
log (reduction).
All formulation's contained Dobanol 91-8 (8 percent) and
polymer (polyac:rylic acid 0.5wt percent), and were adjusted to
pH9. Formulations were diluted 1/30 in test in presence of
WSH (water of standard hardness) and soil (bovine albumin).
Examples are provided both for formulations containing CTAB
and benzalkoniw:n chloride.
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 30 -
ORGANISM CTAB BAAC (%) MEAN LOG
(REDUCTION)
(%)
(2 replicates)
LOW BOIL HIGH
SOIL
1.0 - 4.5 4.7
Staph. aureus
2.0 - 7.4 7.6
- 1.0 7.2 7.2
- 2.0 7.2 7.2
1.0 - 0.1 0.03
Pseudomonas
aeruginosa
2.0 - 0.04 0.01
- 1.0 2.3 2.6
- 2.0 3.5 3.1
1.0 - 4.4 3.5
Saccharomyces
cerevisiae
2.0 - 7.0 2.7
- 1.0 6.0 6.0
- 2.0 6.0 6.0
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 31 -
From the results. given in Table 7 it can be seen that the
levels of cationic used in the compositions of the present
invention are sufficient to give a biocidal effect. Tt can
also be seen that benzalkonium chloride has an improved
biocidal effect even against the normally recalcitrant
Pseudomonas aeruginosa.
In order to show the effect of sequesterant in improving
bacterial kill, formulations were prepared which contained
Dobanol 91-8 (7wt percent) and polymer (VERSIC(7L E11
polyacrylic acid. 0.5wt percent), and were adjusted to pH2l.
Formulations were diluted 1/20 in the presence of WSH (water
of standard hardness) and 0.03 soil (bovine albumin) on final
suspension. Examples are provided for formulations containing
benzalkonium chloride (BAC) at both 1.0 and 2.0 wt~.
Sequesterant, either EDTA or MGDA was used as indicated in
table 8. The test bacteria was Pseudomonas aeruginosa ATCC
15442, and assays were conducted as described above. Examples
which give a log reduction greater than 5 are indicated in
bold.
CA 02280877 1999-08-12
WO 98140452 PCT/EP98/OI273
- 32 -
HAC EDTA MC3DA Log
% % % Reduction
1 0.5 0 1.22
1 1 0 1.1
1 1.5 0 5.54
1 2 0 5.66
1 2.5 0 5.66
2 0.5 0 1.86
2 1 0 2.17
2 1.5 0 5.66
2 2 0 5.3
2 2.5 0 5.66
1 0 0.5 0.89
1 0 1 1.23
1 0 1.5 1.44
1 0 2 4.57
1 0 2.5 5.42
2 0 0.5 1.7
2 0 1 ' 2.95
2 0 1.5 3.46
2 0 2 5.48
I
2 0 2.5 5.74
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 33 -
The results givs:n in Table 8 show that a log five reduction in
viable counts can be obtained by use of appropriate levels of
sequestering agents .
In order to demonstrate the advantages of longer lasting
hygiene which accrue with the compositions of the present
invention, formulations were prepared which contained Dobanol
91-8 (7wt percent) with and without polymer (VERSICOL E11
polyacrylic acid 0.5wt percent), and were adjusted to pHll.
Formulations were diluted 1/20 in the presence of WSH (water
of standard hardness) and 0.038 soil (bovine albumin) on final
suspension. Examples are provided for formulations containing
benzalkonium chloride (BAAC) at both 1.5 and 2.0 wt~.
Sequesterant, either EDTA or MGDA was used as indicated in
table 9.
Efficacy was determined against Staphylococcus aureus NCTC
6538 by means of the method set out below.
Glazed ceramic t=files squares (size = 2.5x2.5cm, were cut
from plain blaclt glazed Cristal (TM) tiles, ex H & R Johnson
with all sloping edges removed. The tiles were cleaned
rigorously before application of the test solution or
product, so than a uniform coverage on a hydrophilic surface
is obtained. Cleaning is undertaken on the day that
application of product, and rinsing is carried out no longer
than 24 hrs before microbiological testing is undertaken.
Tiles were cleaned by applying calcite powder to the tile
and rubbing vigorously with a clean, damp sponge cloth.
Tiles are rinsed with de-ionised water and it was determined
if the tile was hydrophilic all over by allowing a small
amount of water to run over it. The water should run
smoothly over the tile and form an even film over the entire
surface. If an5r area remained hydrophobic calcite was re-
applied and the cleaning process repeated. After cleaning,
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 34 -
tiles were dried by wiping with a clean paper tissue
(Kimsoft (TM) facial tissue).
50u1 of cleaning product (whether a formulation according to
the invention, a control or a comparative example) was
placed on a clean tile and carefully spread it over the
whole tile surface using a flattened micropipette tip. The
tile was allowed to dry in a 30oC incubator then any rinses
were carried out by placing each tile in 100m1 of sterile
WSH for 30 seconds, removing and placing in a 30oC incubator
to dry.
After treatment with the products according to the
invention, comparative examples or controls the tiles were
stored in a microbiological safety cabinet to limit
contamination.
In order to demonstrated the substantive antibacterial
effect, each product was tested in duplicate, using 50u1 of
sterile distilled water as the control formulation for
control tiles. At time zero tiles treated according to the
present invention were inoculated together with a control
tile with 20u1 of culture (as described above) so that there
were approximately 2x10 bacteria/tile in a 0.03 Bovine
Albumin soil. The bacteria were spread over the whole tile
area using a sterile spreader. After 30 minutes contact
time between the bacteria and the tiles, a sterile
microbiological cotton swab was wet with quench solution and
swabbed thoroughly over the tile in two directions at right
angles to each other. The end off the swab was broken off
into l0ml of quench solution and the process repeated with a
dry swab to remove residual liquid and bacteria. Quench
bottles were left for 30 minutes to allow for recovery of
injured cells (60 minutes for E. coli). After recovery each
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 35 -
quench bottle was vortexed for 15 seconds at high speed to
resuspend the cells evenly in the quench solution.
For each tile being tested, a column of wells in a sterile
microtitre plate was inoculated with 270u1 of Peptone water,
leaving the first well empty in each case. The first well
was filled with 300u1 of the quenched swab solutions. A
further 500u1 o:f quenched swab solution was plated directly
onto an agar plate and spread using a sterile spreader.
This plate is used for enumerating low levels of survivors.
Serial 10-fold dilutions of the solutions were prepared by
transferring 30~a1 of solutions in row 1 to row 2; mixing
them, then repeating the procedure down to row 6 so that a
10-6 dilution i;s achieved (pipette tips are changed between
transfers).
For each tile sample taken an agar plate (dried plate face
down with the l:id off in a 60oC oven for 15 minutes prior to
use and marked :into 6 equal segments on its base with a
marker pen) was spotted with 10u1 volumes of liquid onto the
appropriate segment of the plate, placing 3 spots per
segment. All plates were left face up to dry and then
placed face down in an incubator at 37oC for 24 hrs. Counts
were obtained for the plates and 1og10 reduction obtained by
subtracting the 1og10 count[test] from 1og10 count[control].
Results for such a test are shown in table 9 below: all
composition contained soil and nonionic surfactant as noted
above and the other components of the neat cleaning
composition are indicated in the table. As noted above, log
reductions are calculated relative to controls which had been
treated with sterile water rather than a 'cleaning'
composition.
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 36 -
Example BAAC% Polymer% EDTA% MC3DA% Log Red Log Red.
Rinsed Unrinsed
9a 1.5 0.5 - 2.5 1.41 3.49
9b 1.5 - - 2.5 1.01 4.02
9c 1.5 0.5 1.5 - 1.80 3.87
9d 1.5 - 1.5 - 0.35 4.02
9e 2.0 0.5 - 2.5 2.18 4.02
9f 2.0 - - 2.5 0.38 4.02
~9g 2.0 0.5 1.5 - 2.67 4.02
9h 2.0 - 1.5 - 0.01 2.48
From the results in table 9 it can be seen that bacteria
recovered from a surface which had been previously treated
with a composition according to the invention (9a, 9c, 9f or
9h) had a significantly reduced viability of between 2-4 logs
when the surface was not rinsed. This reduction in viability
would be expected given that the surfaces had been exposed to
a biocide-containing solution which had been allowed to dry on
the surface.
For the tiles which had been rinsed, only those treated with
formulations which contained polymer (9a, 9c, 9e and 9g)
showed markedly better than 1 log reduction (90~) of the
recovered bacteria. Formulations using 2~wt BAAC, polymer and
sequesterant (9e and 9g) showed the best results in the
example with a better than 99~ reduction in viable count.
CA 02280877 1999-08-12
WO 98/40452 PCT/EP98/01273
- 37 -
It is believed that these results show that the compositions
of the invention have a persistent antimicrobial effect as
compared with the polymer free control compositions.
Plastic Petri dishes (9cm diameter, 2cm depth) were treated
with 20m1 of test product at the recommended dilution (1:20,
30 min, room temperature), before decanting the solution and
allowing plates to dry. Control plates were untreated.
Prior to dilution the example formulation (10a) contained
Dobanol 91-8 (7~~wt) with polymer (VERSICOL E11 polyacrylic
acid 0.5~wt), cationic surfactant (2gwt BAAC) and sequesterant
(2.5~wt MGDA) and was adjusted to pHl1 with NaOH. Comparative
examples were also performed against Lysoform (TM) a
commercially available disinfectant product.
A suspension of Aspergillus niger spores (ATCC 6275).
prepared in sterile distilled water, was introduced to the
plates (20m1 per plate, 3 x 105 spores/ml). Plates were
agitated in an orbital shaker to distribute spores evenly (1
min, 100 rpm) and left standing at room temperature for 30
min, before re-agitating (1 min, 100 rpm). Supernatants
were discarded and the plates allowed to dry. As the plates
had been allowed to dry after pretreatment and prior to
exposure to the spores, the spores had not been exposed to
relatively high. levels of the pre-treatment compositions.
Initial attachment of spores to the treated and untreated
plates could then be determined by the method given below.
To show the effect of rinsing, duplicate dishes which had
been treated as above (including the exposure to mould
spores) were subjected to rinsing by introducing standard
hard water (lOml) into each dish and mixing (1 min, 100rpm).
CA 02280877 1999-08-12
WO 98140452 PCT/EP98/01273
- 38 -
The supernatant was discarded and the plates dried at room
temperature.
To show the effect of scrubbing duplicate dishes which had
been inoculated with spores as described above were scrubbed
using an epicyclic scrubbing device. Scrubbing of the
surface was achieved through the use of standard, pre-washed
sponge cloths, dampened with standard hard water, at a fixed
pressure of 80g/cm2, (10 cycles, speed 4). Dishes were then
allowed to dry at room temperature as before.
Each of the above plates was viewed under light microscopy
(x40 magnification) and the average number of attached
spores determined from each of five pre-defined fields of
view. Plates from the rinsing and scrubbing experiments
were re-counted and the numbers of spores recorded. The
percentage attachment following each of the treatments was
calculated by the equation:
AveraSxe no. spores countP~ x 100
Average no. spores on untreated control
Results are given in table 10 below, a percentage of spores
attached as compared with an untreated surface
CA 02280877 1999-08-12
WO 98140452 PCT/EP98/01273
- 39 -
Initial Attachment Attachment after
Attachment after rinsing Scrubbing
10a 45.05 32.67 5.41
Lysoform (TM) 64.26 53.07 14.74
Control 100.00 77.53 38.83
As expected, thE: results show that for untreated surfaces
rinsing and scrubbing remove some mould spores, but leave
almost 40~ of the spores on the surface even after
scrubbing. The results show that spores are less likely to
attach to a suri:ace treated with the compositions of the
present invention, and, when spores do attach, they are not
as strongly bound to the surface.
Statistical ana7Lysis of the data showed a significant
decrease (95~ confidence) in the percentage of spores which
attached to the surface in the presence of the polymer-
containing formulation, compared to the reference product
Lysoform (RTM) and as compared with untreated surfaces. As
noted above, this difference was seen at each stage of
treatment.
It is believed that these results show that the compositions
of the invention at least partly prevent the adhesion of
spores to a suri:ace and consequently, it is believed that
the use of a composition according to the present invention
would reduce thE~ rate of regrowth on a clean surface of
micro-organisms including moulds or bacteria which propogate
through spores.
~!~: c~~; 1.:, ;
