Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
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TITLE: BIOCIDAL SURFACE FILMS
FIELD OF THE INVENTION
The present invention relates to a biocidal preparation, in particular to a
biocidal film preparation. The invention has been developed primarily for use
as a
surface disinfectant cleaner and impregnation agent and will be described
hereinafter
with reference to these applications. However, it will be appreciated that the
invention
is not limited to this particular field of use.
BACKGROUND OF THE INVENTION
Biocides are chemical compositions that are widely used in industry for
disinfection and to prevent microbiological contamination and deterioration of
commercial products, materials and systems. Of the biocides presently
available,
phenolic biocides are widely used.
In general, phenolic biocides are colourless and have minimal toxicological
effects to humans i.e. cause little or no irritation to the skin. Although
most phenolics
have a characteristic odour, some of them such as phenylphenols and
dichlorophenes
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have little odour and others such as triclosan have none. These properties are
desirable as they enable such biocides to be used as an ingredient in orally ,
administered pharmaceutical preparations; as an approved biocide for use in
food
establishments and plants; and in packaging material.
Phenolic biocides also have other desirable properties including a wide
biocidal spectrum against microorganisms such as bacteria and fungi; residual
bacteriostatic properties; and unlike other biocides are not readily
deactivated by
organic matter such as blood, serum and milk. These biocides therefore have a
wide
application as disinfectants and antimould products in general household,
industrial,
and other areas requiring disinfection, as they can be used in the destruction
of the
microorganisms present or the prevention of their further proliferation to
numbers that
would be significantly destructive to the substrate or system being protected.
An example of a phenolic biocide is dichlorophene which, in addition to its
antibacterial properties, is particularly effective against fungi such as
yeast mould and
mildew. This property enables such derivatives to be used mainly as a
preservative
against mildew and rot in a variety of products including paper and textiles.
Another example of a phenolic biocide used is trichloro hydroxy diphenyl
ether (Triclosan) which is an effective ingredient in deodorant and in skin
cleansing
preparations.
Hitherto, phenols have been used in industrial cleaners in an aqueous solution
at very high pH (above pH 11). The use of cleaners with such high pH is
undesirable
in households. In order to overcome this problem, phenols have been used in
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alcoholic solution but such use leaves visable surface residues and is
disadvantageous
for household use.
To obtain aqueous detergent solutions of phenolic biocides they have first to
be converted into their water soluble alkali salts, usually with sodium
hydroxide,
resulting in alkaline solution of a pH of at least 11Ø The high alkalinity
of these
solutions excludes them from application in households and on surfaces
susceptible to
deterioration by alkalis. Their use has therefore been restricted to
industrial cleaners
for stainless steel equipment and hard floor surfaces in food processing and
glass
bottle washing plants and other industrial plants and areas where the higher
alkalinity
is acceptable.
When dissolved in alcoholic-aqueous mixture with the addition of a small
amount of a suitable surfactant to form a disinfectant cleaning preparation,
such
solution will on drying leave streaks and partly greyish areas on treated
surfaces due to
the remaining insoluble residues of the biocide.
Triclosan which finds its main application in antiseptic skin and hand
cleansing preparations has been either used in suspension, or solubilised with
non-
ionic surfactants with resultant loss in activity.
In mildew and rot proofing of paper and textiles phenylphenol and especially
dichlorophene are widely used as their sodium salt solution for the
impregnation of
these materials against fungal infection and prevention of mould formulations.
The high alkalinity of these solutions causes weakening of the strength of
fibres and loss of the biocides either by leaching out in moist climates or by
lack of
binding to the surfaces treated. This has been prevented in the past by
neutralisation
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of the alkali salt and/or bonding the biocides by means of a metal salt such
as
zirconium acetate. These processes necessitate a further manufacturing
procedure, use
of additional equipment and additional cost for the neutralising agent. These
additional measures are required as bonding the biocidal agent onto the
material to be
protected was not always effective, especially when prolonged periods of
protection
were required.
OBJECT OF THE INV NTION
It is therefore an object of the invention to ameliorate at least some of the
above disadvantages.
Preferred embodiments of the invention overcome the above disadvantages by
providing a liquid biocidal preparation for the disinfection of solid surfaces
and
impregnation of paper, textiles and non-woven fabrics which at the same time
protects
them against reinfection by microorganisms.
DISCLOSURE OF THE INVENTION
According to a first aspect the present invention consists in a biocidal
preparation comprising a halogenated phenolic biocide and less than 8 wt% of a
polyvinylpyrrolidone polymer or copolymer dissolved in an aqueous alcoholic
solvent, the combination drying on evaporation of the solvent to form a clear
film.
For preference the biocide is selected from the group consisting of triclosan,
dichlorophene, chlorophene, p-chloro-m-xylenol (PCMX), hexachlorophene, o-
phenylphenol, pentachlorophenol (PCP) and bromophene.
Preparations according to the invention surprisingly provide a substantially
aqueous solution of a biocide preparation which in the pH range of 2-10.0 on
drying
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form clear films with disinfecting properties on the treated surface (which
can be
organic or nonorganic) and provides good adherence. The inventors believe that
a
colourless complex is formed between the polymer (or copolymer) and the
selected
phenolic biocide which surprisingly results in a desirably clear film.
If desired, a rot proofing solution can be added during the manufacturing
process to the pulp of paper or textile fibres prior to sheeting and drying.
It has been
found that in this use preparations according to the invention provide
excellent
binding to the substrate with slow release of the biocide and without
interfering with
the feel or "handle" of the textile.
According to a second aspect the present invention consists in a general
household cleaner comprising:
0.1-3% by weight of dichlorophene or a combination of dichlorophene with o-
phenylphenol, and
less than 8% by weight of a polyvinylpyrrolidone polymer or copolymer in an
aqueous alcoholic solvent.
According to a third aspect the present invention consists in a medical
cleaner
comprising:
0.1-5.0% by weight of triclosan, and
less than 8% by weight of a polyvinylpyrrolidone polymer or copolymer thereof,
in an aqueous alcoholic solvent.
According to a fourth aspect the present invention consists in a process of
preparing a biocidal composition comprising the steps of combining a phenolic
biocide selected from triclosan, dichlorophene, chlorophene, p-chloro-m-
xylenol
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(PCMX), hexachlorophene, o-phenylphenol, pentachlorophenol and/or bromophene,
with
less than 8 wt%, based on the total weight of the composition, of a
polyvinylpyrrolidone
or copolymer in an aqueous alcoholic solvent.
The biocidal solutions are best prepared by prior dissolving the biocide and
the
polymer in alcohol(s) with subsequent addition of watei- not exceeding the
amount which
would cause turbidity and separation of the biocide.
Desirably, an effective amount of at least one anionic or non-ionic surfactant
or a
combination of both is included in the preparation.
According to a fifth aspect, the invention consists in a non-woven fabric
wherein
the binder includes at least one phenolic biocide, a water soluble film
forming polymer,
and at least one surfactant.
According to a sixth aspect, the present invention consists in a method of
impregnating a fabric to prevent rot comprising contact'iing a non-woven
fabric with a
biocidal preparation containing at least one phenolic biocide, a water soluble
film
forming polymer, and at least one surfactant.
PREFERRED EMBODIMENTS OF THE INVENTION
The film forming polymers preferably used in the present invention are
polymers
in which the biocide is soluble, and are usually selected based on their
intended
application. Polyvinylpyrrolidone (PVP) and its copolymers with vinylacetate,
aminoacrylates, and trimethylammonium chloride are a preferred choice for
disinfecting
surface cleaners with residual biocidal activity and polyvinyl-maleic
copolymers for
impregnation of paper and textile materials. More preferably for disinfecting
and
cleaning, polyvinylpyrrolidones with a degree of polymerisation (K
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value) of 15, 30, 60 and 90 (most preferably a polyvinylpyrrolidone with a
degree of
polymerisation of 90) or copolymers with vinylacetate comprising from 20 to
80%
polyvinylpyrrolidone, (most preferably comprising at least 50% vinylacetate
and
possessing cationic character) are used. Another suitable polymer for
disinfecting/cleaning is QAFQUAT-HSTM made by ISP Corporation, USA.
For impregnation, the amount of polymer used is preferably in the range of
from
0.01 parts of the polymer to 99.9 parts of polymer for each 1 part of phenolic
biocide.
More preferably the polymer is in the range of from 0.01 to 50 parts and most
preferably
from 0.01 to 1 part for each part of phenolic biocide. For
disinfecting/cleaning, the
amount of polymer used is preferably less than 8 wt%, inost preferably less
than 2 wt%
based on the weight of the composition.
Preferably, the phenolic biocides are selected from the group consisting of
pentachlorophenol (PCP); p-chloro-m-xylenol (PCMX); hexachlorophene; o-
phenylphenol; dichlorophene; chlorophene; bromophene; Triclosan or a
combination of
these biocides.
For general household cleaners and for disinfecting food preparation surfaces
phenolic biocides dichlorophene or a combination of dichlorophene with o-
phenylphenol
are recommended. The concentration of the phenolic biocides in solution is
preferably in
the range of from 0.2-1.0% and more preferably from 0.2- 0.5% by weight of the
composition.
For medical professional premises the preferred biocide is triclosan used at a
concentration preferably in the range of from 0.1-3.0%, and more preferably
from 1.0
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2.0% by weight of the composition. The biocidal preparation can be used for
disinfecting medical instruments such as endoscopes.
The concentration of the biocides used for the impregnation of paper and
textiles is often dependent on the method of preparation. Preferably. the
amount of
uptake is between 0.05 to 1.0% based on the weight of the material. More
preferably
the range is between 0.1 to 0.5% by weight of the material.
Where a surface disinfectant cleaner is required a certain amount of a
detergent
should be included in the preparation. The detergent is preferably selected
from the
range of anionic surfactants, although other surfactants can also be used on
their own
or in combination with an anionic surfactant. It is also advantageous to
include a
small amount of a surfactant in an impregnation solution to ensure uniform
wetting of
the treated material.
Suitable anionic surfactants include sodium salts of dodecylbenzenesulphonate
and laurylether sulphate; phosphate esters of nonylphenolethoxylates;
nonylphenoxyphosphoric acid esters or a combination of these surfactants. A
preferred surfactant is the sodium salt of dodecylbenzenesulphonate which can
be used
on its own or in combination with another anionic surfactant.
An effective amount of surfactant will depend on the intended application of
the final product. That is, a disinfectant surface cleaner product will have a
relatively
high proportion of surfactant to ensure it has good cleaning properties. On
the other
hand for impregnation of paper and textile materials the content of the
surfactant will
be much lower as their purpose is only in wetting the surfaces of the paper
and textile
fibres and assuring better penetration.
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Suitable alcohols include any water soluble lower alkyl alcohols such as
methanol
and ethanol but higher alkyl alcohols such as iso- and n-Propanol may be used
on their own
or in combination with lower alcohols preferably in an amount not exceeding
30% weight
by volume in disinfectant cleaner and impregnation liquid.
It is advantageous where a higher degree of disinfection is desired, to
include one or
more aromatic alcohols such as Benzyl-, Phenoxy-and dichlorobenzylalcohol
generally in an
amount of not more than 2.0% by weight.
The invention will now be more particularly described by way of example only
with
reference to the following examples:
Example 1
Biocidal Surface Cleaner Domestic
Dichlorophene 0.3 Kg.
Gardinol*TM25L 5.0 Kg.
AnthroxTM C0630** 0.5 Kg.
PVP 0.75 Kg.
isopropanol 25.00 L
water to make 100.0 L
* Sod. Dodecylbenzosulphonate ex Albright & Wilson
** Nonyl Phenol Ethoxylate ex Rhone-Poulenc
Example 2
Biocidal Surface Cleaner Institutional
(% by weight of composition)
Dichlorophene 0.3%
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o-phenylphenol 0.2%
LuviskolTM VA60140* 0.4%
GardinolTM 25L 5.0%
RhodafacTM RE-610** 0.5%
isopropanol 30.0%
water to make 100.0 parts by volume
* Polyvinyl-vinylacetate polymer 60/40 ex-BASF Inc
** Rhone-Poulenc
Example 3
Biocidal Surface Cleaner for Medical Premises
(%by weight of composition)
Triclosan 0.5%
Phenoxyethanol 1.0%
AntaronTM P904* 1.5%
GardinolTM 25L 5.0%
n-Propanol 30.0%
Fragrance as desired
water to make
100 parts by volume
*alkylated vinylpyrrolidone polymer ex-ISP Chemicals
Example 4
Biocidal Bathroom and Tile Cleaner
Sodium carboxy methyl cellulose 0.35%
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Dichlorophene 0.50%
Ethanol (95%) 5.00%
Isopropanol 5.00%
NansaTM SSA/S* 4.00%
TericTM N 10** 2.00 />
EDTA 4 Na 0.10%
Tri-sodiumpolyphosphate 1.00%
Sodium Hydroxide adjust to pH 7.5-8.0
Hydrogene Peroxide 35% 12.00%
Water q.s. to 100,00
* Sodium dodecyl benzene sulphonate, Albright & Wilson
** Nonyl phenolethoxylate ICI Chemicals
Impregnation Fluid
Formulations prepared for this purpose will dependl on the type of material to
be
impregnated, the degree of rot proofing required and the type and conditions
of application.
The recommended phenolic biocide for that purpose is dichlorophene with a
deposit
of 0.1-0.7 /o by weight of the material for textiles and 0.05--0.5% by weight
of the material
for paper. Film forming polymers to be used would be a polyvinyl maleic
polymer such as
GantrezTM AN (GAF Inc.). The alcohol could be isopropyl and the concentration
of the
anionic surfactants would be sufficient to obtain satisfactolry wetting of the
surfaces to be
treated. Due to possible excessive foaming in some formulations, a de-foaming
agent(s) is
sometimes added.
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A typical formulation for the impregnation of a non-woven cloth would be:
Dichlorophene 12.0kg
GantrezTM AN 119* 0.3g
EmpicolTM SQ770** 2.75g
Ven GellTM B+** 0.5kg
Water to make 30.0kg
* Sod.Laurylalkoxysulfate ex Albright & Wilson
** Polyvinyl maleic polymer ex GAF Inc
* * * Ex-Veegum Vanderbilt Co. Inc.
The components are mixed into a uniform slurry. The amount is incorporated
into
200kg of a standard binder - resulting in an active content of dichlorophene
of about
5.0% by weight. At an average pick-up of the binder of 7g/sq metre, the
deposit of the
biocide will be approximately 0.3% by weight.
The invention extends additionally to include a i:ilm formed from a
preparation as
described and to a method of treating a surface by application of a
preparation as
described.
Although the invention has been described with reference to specific examples,
it
will be appreciated by those skilled in the art that the invention may be
embodied in
many other forms.
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