[0001] The present invention relates to the use of a composition comprising an alkyd resin
and an organic solvent for the repeated sanitizing or cleansing of a surface.
[0002] Sanitizing surfaces is well known in the art. For example, treatment by ozone or
chlorine containing gases is known for disinfecting surfaces and containers and cleaning
and removal of organic contaminants.
[0003] It is also known to apply ultraviolet (UV-) radiation to disinfect surfaces, containers,
and even liquids. Further, it is known to apply silver ions or copper ions to solutions
and surfaces in order to reduce the microbiological contamination.
[0004] Surfaces are also frequently disinfected with aqueous solutions comprising alcohols,
such as iso-propanol, hydrogen peroxide or NaOCl.
[0005] The disinfection of a surface with an aqueous solution of, for example, hydrogen
peroxide or iso-propanol has the disadvantage that the effect is of only very short
duration because the hydrogen peroxide decomposes and the iso-propanol evaporates.
After decomposition or evaporation of the disinfectant, the surface can again be contaminated
with, for example, bacteria. This requires a frequent disinfection of the surface
and it always remains the risk that between two disinfection cycles the surface becomes
contaminated and potentially does not have the required low level of bacteria or other
microorganisms.
[0006] In an alternative approach it is known from
EP 3 426 739 that alkyd resins provide antimicrobial properties to a surface. While this provides
a good long-term effect, there remains the problem that the alkyd resin should preferably
be applied to an already disinfected surface, which requires an additional disinfectant
and a further disinfection step prior to the coating of the surface with the alkyd
resin layer.
[0007] It would therefore be desirable to have one disinfecting composition which provides
an immediate disinfection effect and at the same time provides a long-term effect,
which prevents the treated surface from contamination with bacteria and other microorganisms
between two disinfections cycles.
[0008] In an effort to solve this problem, the present inventors combined the known immediately
acting disinfectants with alkyd resin compositions. However, it turned out that if
such combined composition is repeatedly applied to a surface, an increasing alkyd
resin layer is retained on the surface. The thickness of this layer increases with
each disinfection cycle and after some time, increases to an extent which can make
the surface unsuitable for the intended purpose. Removing such alkyd resin layer can
be quite cumbersome and makes a mere combination of usual disinfectants with an alkyd
resin composition undesirable for a repeated disinfection of a surface.
[0009] Upon further investigations, the present inventors found that, if the alkyd resin
is combined with certain organic solvents, it is possible to provide a composition
which, when applied to a surface, exhibits an immediate antimicrobial effectivity
and leaves an alkyd resin layer on the surface, which provides a long-term antimicrobial
effect, but when the composition is applied repeatedly to the same surface, the thickness
of the alkyd resin layer does not increase.
[0010] The present invention therefore relates to the use of a composition comprising an
alkyd resin and an organic solvent for the repeated sanitizing or cleansing of a surface,
wherein the alkyd resin comprises fatty acid residues, which contain at least six
carbon atoms in their saturated or unsaturated aliphatic chain, and the organic solvent
is selected from the group consisting of alcohols, esters, ketones, ethers, aldehydes
and mixtures thereof.
[0011] In the context of the present invention the term "sanitizing" is characterized by
the ability to deter, render harmless, destroy and/or exert a controlling effect on
all forms and/or parts of microbial life (e.g. bacteria, viruses, fungi, spore forms,
etc.); and/or by the ability to remove and/or reduce offensive and/or unpleasant scents.
"Sanitizing" therefore includes an antimicrobial effect.
[0012] In the context of the present invention the term "cleansing" is characterized by
the ability to remove dirt.
[0013] In the context of the present invention, the term "repeated" is to be understood
as describing an action which is repeated at least two times, preferably at least
three or four times, more preferably at least five, six of seven times, and even more
preferably at least eight, nine or ten times, in particular at least ten times. Between
two repetitions of the action, there can be a time span of a few seconds, such as,
for example, 5 seconds, 10 seconds, 20 seconds, 30 seconds, 40 seconds, 50 seconds
or 60 seconds. The time span between two repetitions of the action can, however, be
considerably longer as, for example, 30 minutes, 1 hour, 2 hours, 6 hours, 12 hours,
1 day, 1 week, or even longer. Preferably, the time span between the repetition of
two actions is at least as long as it requires for the organic solvent to evaporate.
[0014] The term "antimicrobial", as used herein, refers to the ability of the composition
to kill microorganisms.
[0015] The term "microorganism", as referred to herein, includes bacteria, viruses, fungi
and algae. Preferably, the term "microorganism", as used herein, refers to bacteria
and viruses.
[0016] The ability to kill microorganisms results in disinfecting, antifouling, self-sanitizing
and and/or biocidal effects. In this context "antifouling" refers to the ability to
prevent or remove biofouling on wetted surfaces. Biofouling is the accumulation of
microorganisms, plants, algae or animals on wetted surfaces and killing such microorganisms,
including algae, supports the prevention or removal of biofouling.
[0017] The term "surface", as referred to herein, includes surfaces of bodies of any material,
including for example polymers, metal, glass and stone, as well as coatings on such
bodies. The bodies may have any shape including for example plates, sheets, fibers
and tubes.
[0018] The term "alkyd resin", as used herein, refers to a polyester modified by the addition
of fatty acids and optionally other components. Alkyd resins are derived from a di-,
tri- or polyol and a di-, tri- or polycarboxylic acid or carboxylic acid anhydride.
The monomers as such are not encompassed by the term "alkyd resin".
[0019] The di-, tri- or polyacid can for example be selected from the group consisting of
oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid,
suberic acid, azelaic acid, cebacic acid, maleic acid, fumaric acid, glutaconic acid,
malic acid, aspartic acid, glutamic acid, tartaric acid, phthalic acid, isophthalic
acid, terephthalic acid and/or mixtures thereof. Anhydrides of these acids are also
suitable. Preferably, the acid residue in the polyester is a diacid residue.
[0020] The di-, tri- or polyalcohol can for example be selected from the group consisting
of ethylene glycol, butylene glycol, pentanediol, neopentyl glycol, hexylene glycol,
diethylene glycol, dipropylene glycol, triethylene glycol, glycerol, trimethylolethane,
trimethylopropane, pentaerythritol, methylglucoside, sugars, sugar alcohols, such
as mannitol, xylitol and sorbitol and/or mixtures thereof.
[0021] In addition to the fatty acid residue the polyester backbone in the alkyd resin can
be modified by any other organic residue, preferably a hydrophobic residue, more preferably
a hydrophobic residue which does not contain any additional reactive functional groups
as defined below.
[0022] The term "fatty acid" refers to a carboxylic acid having an aliphatic chain. In one
embodiment, the aliphatic chain is saturated. In another embodiment, the aliphatic
chain is unsaturated. The number of C-atoms in the aliphatic chain can be in the range
from 6 to 40 C-atoms, preferably 6 to 26 C-atoms or 6 to 18 C-atoms. Even more preferably
the number of C-atoms in the aliphatic chain is at least 10 or at least 15. More preferably
the number of C-atoms in the aliphatic chain is in the range of 6 to 40, 6 to 26,
6 to 20, 10 to 40, 10 to 26, 10 to 20, 15 to 40, 15 to 26 or 15 to 20; 15 to 20 being
particularly preferred.
[0023] Preferably, the fatty acid is selected from the group consisting of caproic acid,
caprylic acid, capric acid, myristoleic acid, palmitoleic acid, sapienic acid, oleic
acid, elaidic acid, vaccenic acid, linoleic acid, linoelaidic acid, α-linolenic acid,
arachidonic acid, palmitic acid, stearic acid, lauric acid, myristic acid and/or combinations
thereof. In another embodiment, the fatty acid can be di- or trifunctional and is
selected from the list consisting of adipic acid, fumaric acid, isophthalic acid,
maleic acid, phthalic acid, succinic acid, citric acid and/or combinations thereof.
In a further embodiment, the fatty acid is an anhydride of the above named fatty acids.
[0024] In one embodiment the fatty acid does not contain any additional reactive functional
group, such as hydroxy, amino, sulfo, phosphato, carboxy, carboxy-amid, cyano, etc.
Possible unsaturations in the fatty acid residues are not considered as reactive functional
groups in the sense of the present invention.
[0025] In one embodiment, the alkyd resin is a linear polyester. A linear polyester, as
defined herein is a difunctional molecule and has two reactive sites.
[0026] In another embodiment, the alkyd resin is a branched polyester containing fatty-acid
side groups. A branched polyester, as defined herein is a tri-, tetra-, or higher
functional molecule and has three, four, or more reactive sites. Branched polyester
may form, as linear polyester, molecular chains, but, in addition, branching connections
are formed, which result in a three-dimensional network (cross-linking).
[0027] In addition to the alkyd resin, the composition used in the present invention comprises
and organic solvent being selected from alcohols, esters, ketones, aldehydes and mixtures
thereof. Suitable alcohols have, for examples, 1 to 5, preferably 1 to 4 carbon atoms.
Examples of suitable alcohols are methanol, ethanol, n-propanol, iso-propanol, n-butanol,
iso-butanol, tert-butanol and mixtures thereof.
[0028] Suitable ketones usually comprise from 3 to 10, preferably from 3 to 6 carbon atoms.
Examples of suitable ketones are ethyl methyl ketone, acetone and mixtures thereof.
[0029] Suitable esters usually contain from 3 to 10, preferably from 3 to 6 carbon atoms.
A suitable ester is, for example, ethyl acetate.
[0030] Suitable aldehydes usually contain from 1 to 6, preferably from 1 to 5 carbon atoms.
A suitable aldehyde is, for example, formaldehyde.
[0031] In one embodiment, the composition further comprises and/or the alkyd resin is modified
with an unsaturated or saturated oil.
[0032] Preferably, the unsaturated or saturated oil is selected from the group consisting
of tung oil, linseed oil, sunflower oil, safflower oil, walnut oil, soybean oil, fish
oil, corn oil, tall oil, dehydrated castor oil, coconut oil, rapeseed oil, peppermint
oil, pine oil, lavender oil, safflower oil, walnut oil, fish oil, corn oil, tall oil,
dehydrated castor oil, cumin oil, flax oil, vernonia oil and/or mixtures thereof.
Linseed oil, sunflower oil, coconut oil, rapeseed oil, peppermint oil, pine oil, lavender
oil, soybean oil, safflower oil, walnut oil, fish oil, corn oil, tall oil, dehydrated
castor oil, cumin oil, flax oil, wood oil and vernonia oil being particularly preferred.
[0033] The above oils can be present in the composition as such or as derivatives thereof,
for example as their fatty acid, monoester, fatty acid diester, and esters with other
carboxylic acids, such as ascorbic acid, acetic acid, propionic acid, benzoic acid
or lactic acid.
[0034] Further possible additives in the composition are for example fatty acids, in particular
those as described above, oct-1-en-3-ol, citronellal and pheromones of clothing mots,
such as for example (Z, E)-tetradeca-9,12-dienyl acetate.
[0035] The amounts of alkyd resin and organic solvent in the composition used in the present
invention are not particularly limited and may be selected by the person skilled in
the art according to the requirements. It was, however, surprisingly found that when
applying the composition of the present invention repeatedly to a surface, an equilibrium
between the built-up of the thickness of the alkyd resin layer and the removal of
the alkyd resin layer adjusts and that it is possible to tailor this equilibrium by
the ratio of alkyd resin to organic solvent in the composition. The higher the amount
of alkyd resin relative to the amount of organic solvent in the compositions is, the
thicker the alkyd resin layer will be on the surface after repeated use of the composition
until the equilibrium has been adjusted.
[0036] In one embodiment, the composition comprises from 1 to 99 % by weight of the alkyd
resin and from 1 to 99 % by weight of the organic solvent, each based on the total
weight of the composition. In a further embodiment, the composition comprises from
3 to 80 % by weight, preferably from 5 to 70 % by weight and more preferably from
10 to 60 % by weight of the alkyd resin, based on the total weight of the composition.
The amount of organic solvent usually is equal to or higher than the amount of alkyd
resin. Thus, the weight ratio of alkyd resin to organic solvent may, for example,
be in the range of 1:100 to 1:1, preferably in the range of 1:80 to 1:1, more preferably
in the range of 1:50 to 1:1, and even more preferably in the range of 1:10 to 1:2.
[0037] The composition may consist of the alkyd resin and the organic solvent. Alternatively,
the composition may comprise further components, such as the above described oil.
If the composition contains components further to the alkyd resin and the organic
solvent, the weight ratio of the alkyd resin to the organic solvent preferably is
within the above ranges.
[0038] Alkyd resins comprising an unsaturated or saturated oil are classified by the amount
of oil based on the total weight of the resin. In one embodiment, the amount of unsaturated
or saturated oil is higher than 60 wt.-% (long-oil alkyd resin), between 40 wt.-%
and 60 wt.-% (medium-oil alkyd resin), or lower than 40 wt.-% (short-oil alkyd resin)
based on the total weight of the alkyd resin. In a preferred embodiment the alkyd
resin is a medium-oil alkyd resin or a long-oil alkyd resin.
[0039] In one embodiment, the alkyd resin is a drying or a non-drying alkyd resin.
[0040] Drying alkyd resins cure at approximately 20°C or by drying at 60°-80°C. Non-drying
alkyd resins do not dry at these temperatures, but are cured by baking.
[0041] In one embodiment, the composition further comprises a siccative (oil-drying agent),
which catalyzes the curing of the alkyd resins. Siccatives are typically derived from
cobalt, calcium, strontium, barium, manganese and iron ions. In another embodiment,
the alkyd resin does not contain any siccatives.
[0042] Suitable alkyd resins are, for example, WorleeKyd B 845 (Worlee-Chemie GmbH, Germany),
Setal 196 XX (Nuplex, USA, Kentucky) or Alkydal F26 XX, Alkydal F251 X (Covestro,
Germany) and Mundex W or Mundex Pro (Munditia Technologies GmbH).
[0043] In one embodiment, the composition additionally reduces the growth of a biofilm on
the surface. The term "additionally" as used herein has the meaning of "simultaneously"
and/or "sequentially".
[0044] The term "biofilm", as used herein, refers to an assembly of microorganisms wherein
cells stick to each other on the surface of a substrate. The term "growth of biofilm"
or "biofilm growth", as used herein, refers to the microorganism built-up adhering
to a surface.
[0045] The term "reduction of the growth of a biofilm", as used herein, refers to the decrease,
preferably the inhibition, of the microorganism built-up on a long term scale, i.e.
at least 1 week, preferably at least 1 month, more preferably at least 1 year, even
more preferably at least 3 years, on the surface being treated with a composition
as described herein compared to the surface not being treated with a composition as
described herein.
[0046] In one embodiment, the compositions as described herein are particularly suitable
for simultaneously imparting antimicrobial properties to a surface and reducing, particularly
inhibiting, the growth of a biofilm on the surface, thereby reducing, preferably inhibiting,
the growth of biofilm on a surface and maintaining the microbial efficacy of the alkyd
resins on a long term time scale (at least 2 weeks, preferably at least 1 month, more
preferably at least 1 year, even more preferably at least 3 years).
[0047] A particular advantage of the use, according to the present invention, is the finding
that alkyd resins itself without the requirement of any further biocidally acting
compound provides the desired long-term antimicrobial effect. Therefore, in a particularly
preferred embodiment of the present invention the composition is free of any additional
antimicrobial compound (except the organic solvent), in particular free of any biocidal
product as defined in Article 3(1)(a) of the Regulation (EU) No. 528-2012 of the European
Parliament and the Counsel of 22 May 2012. In particular, the composition used in
the present invention preferably does not contain any nanoparticles, such as metal
nanoparticles, in particular silver nanoparticles. Preferably the composition is free
of silver, organotin and gum rosin.
[0048] In a further embodiment the composition used according to the present invention does
not contain any internal biocides, preferably the alkyd resin does not contain any
internal biocides and any external biocides. In this context "internal biocides" are
understood as compounds having biocidal activity (in particular those compounds as
defined in Article 3(1)(a) of the Regulation (EU) No. 528-2012 of the European Parliament
and the Counsel of 22 May 2012), which are chemically bound to the alkyd resin, such
as the gum rosin in the alkyd resin of example 1 of
WO 2010/040903 or the organotin compound in the alkyd resin of
US 4,039,494. "External biocides" are to be understood as those biocidal compounds which are present
in the alkyd resin, but which are not chemically bound to the alkyd polymer.
[0049] The composition of the present invention may comprise any further suitable compositions,
in particular further organic solvents and also water. The water content should, however,
be at a concentration at which the formation of the equilibrium in the thickness of
the alkyd resin is not adversely affected. In this regard, it was found that a water
concentration of up to 50 % by weight, preferably up to 45 % by weight and more preferably
up to 40 % by weight based on the total weight of the composition is generally tolerable.
[0050] The present invention furthermore relates to a method for the repeated sanitizing
or cleansing of a surface comprising the repeated applying of a composition to the
surface, wherein the composition comprises an alkyd resin and an organic solvent,
wherein the alkyd resin comprises fatty acid residues, which contain at least 6 carbon
atoms in their saturated or unsaturated aliphatic chain, and the organic solvent is
selected from the group consisting of alcohols, esters, ketones, aldehydes and mixtures
thereof.
[0051] All preferred embodiments described above with respect to the use of the present
invention also apply to this method.
Examples
[0052] One composition according to the invention (example 1) and two comparative compositions
(comparative examples 1 and 2) were prepared and repeatedly applied to the surface
of an aluminum plate (10 cm x 10 cm). Each time 2 g of the composition were applied
to the surface and spread with a soft cloth. The plate was weighed before the first
application of the composition and after each application of the composition after
the coating had been dried. From the weight gain it can be concluded whether the alkyd
resin layer formed on the surface of the aluminum plate increases in thickness after
each application of the composition.
[0053] The composition of example 1 was a mixture of 50 g Mundex Pro (alkyd resin) and 50
g of iso-propanol. The composition of comparative example 1 was a mixture of 50 g
of Mundex Pro (alkyd resin), 47 g of water and 3 g of a 30-33 % hydrogen peroxide
solution. The composition of comparative example 2 was a mixture of 50 g of Mundex
Pro (alkyd resin) and 50 g of a 5 % NaOCI solution in water.
[0054] The results of the experiments are summarized in the following table 1.
Table 1
Application of composition |
Weight of plate [g] |
Example 1 |
Comparative Example 1 |
Comparative Example 2 |
0 |
22.11 |
21.78 |
21.74 |
1 |
22.12 |
21.79 |
21.75 |
2 |
22.12 |
21.81 |
21.76 |
3 |
22.13 |
21.82 |
21.77 |
4 |
22.13 |
21.82 |
21.78 |
5 |
22.13 |
21.83 |
21.78 |
6 |
22.14 |
21.83 |
21.79 |
7 |
22.14 |
21.84 |
21.81 |
8 |
22.14 |
21.85 |
21.82 |
9 |
22.14 |
21.86 |
21.82 |
10 |
22.14 |
21.87 |
21.84 |
[0055] From the data in the above table it is evident that, if the aluminum plate was repeatedly
sanitized according to the invention (example 1), the built-up and removal of the
alkyd resin layer on the surface reached an equilibrium after 6 repetitions of the
application of the composition to the surface and the thickness of the alkyd resin
layer did not further increase. With the comparative compositions (comparative examples
1 and 2) there was no such equilibrium but the thickness of the alkyd resin layer
increased with each repetition of the application of the composition to the surface.
The composition being used according to the invention therefore was significantly
more suitable for the repeated sanitizing of a surface even for a very high number
of repetitions.
1. Use of a composition comprising an alkyd resin and an organic solvent for the repeated
sanitizing or cleansing of a surface, wherein the alkyd resin comprises fatty acid
residues, which contain at least six carbon atoms in their saturated or unsaturated
aliphatic chain, and the organic solvent is selected from the group consisting of
alcohols, esters, ketones, ethers, aldehydes and mixtures thereof.
2. Use according to claim 1, wherein the sanitizing includes the killing and/or the prevention
or reduction of growth of bacteria, fungi, viruses and/or algae, as well as the provision
of antifouling properties.
3. Use according to claim 1 or 2, wherein the alkyd resin is a polyester modified with
fatty acid residues.
4. Use according to claim 3, wherein the polyester is linear or branched.
5. Use according to any of the preceding claims, wherein the organic solvent is an alcohol,
preferably an alcohol selected from the group consisting of methanol, ethanol, n-propanol,
iso-propanol, n-butanol, iso-butanol, tert-butanol and mixtures thereof.
6. Use according to any of the preceding claims, wherein the organic solvent is or additionally
comprises a ketone and/or an ester and/or an ether, preferably a ketone selected from
the group consisting of ethyl methyl ketone, acetone and mixtures thereof and/or an
ethyl acetate ester.
7. Use according to any of the preceding claims, wherein the composition further comprises
and/or the alkyl resin is modified with an unsaturated or saturated oil.
8. Use according to claim 7, wherein the unsaturated or saturated oil is selected from
the group consisting of linseed oil, sunflower oil, coconut oil, rapseed oil, peppermint
oil, pine oil, lavender oil, soybean oil, safflower oil, walnut oil, fish oil, corn
oil, tall oil, dehydrated castor oil, cumin oil, flax oil, wood oil, vernonia oil
and mixtures thereof.
9. Use according to any of the preceding claims, wherein the composition comprises from
1 to 90 % by weight of the alkyd resin and from 1 to 99 % by weight of the organic
solvent, each based on the total weight of the composition.
10. Use according to any of the preceding claims, wherein the alkyd resin is a medium-oil
alkyd resin or a long-oil alkyd resin.
11. Use according to any of the preceding claims, wherein the alkyd resin is a drying
alkyd resin or a non-drying alkyd resin.
12. Use according to any of the preceding claims, wherein the composition further comprises
a siccative.
13. Use according to any of the preceding claims, wherein the sanitizing or cleansing
additionally includes the reduction of the growth of a biofilm on the surface.
14. Use according to any of the preceding claims, wherein the composition does not contain
any further internal or external biocidal compound, preferably no further internal
biocidal compound.
15. Method for the repeated sanitizing or cleansing of a surface comprising the repeated
applying of a composition to the surface, wherein the composition comprises an alkyd
resin and an organic solvent, wherein the alkyd resin comprises fatty acid residues,
which contain at least six carbon atoms in their saturated or unsaturated aliphatic
chain, and the organic solvent is selected from the group consisting of alcohols,
esters, ketones, ethers and mixtures thereof.