Composition for prevention of biofouling

Field of the Invention

The present invention relates to compositions and method for preventing biofouling especially on marine vessels and structures and surfaces prone to algae growth.

Background of the Invention

Growth of biofilms such as algae and/or especially barnacle growth below the waterline on marine vessels is an issue as it results in increased water resistance of the vessel in motion thereby requiring regular maintenance/cleaning of the vessel. To avoid the need for maintenance various commercial products exists, however these products may be a risk to marine life due to toxicity.

Object of the Invention

Thus, it is an object of the present invention to provide a composition with reduced toxicity for preventing or reducing growth of biofilms.

Description of the Invention

The present invention provides an anti-biofouling composition with reduced toxicity comprising bitumen as the active anti-biofouling component in total concentration of 0.1 - 100 % which has been shown to reliably reduce the growth of biofilms such as growth of algae and/or barnacles on submerged surfaces of marine vessels and structures and non-submerged structures prone to e.g. algae growth. The present invention further provides an anti-biofouling composition comprising bitumen and a capsaicinoid source as the active anti-biofouling components.

In one embodiment the present invention provides an anti-biofouling composition with reduced toxicity comprising bitumen as the active anti-biofouling component in total concentration of anti-biofouling composition comprising bitumen in a total concentration between 5-60% w/w. In one embodiment the present invention provides an anti-biofouling composition with reduced toxicity comprising bitumen and at least one capsaicinoid source is present in a total concentration of 10 - 80, 10 - 75, such as 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80% w/w. In one embodiment the present invention provides an anti-biofouling composition with reduced toxicity comprising bitumen and at least one capsaicinoid source, wherein the ratio of bitumen and/or the at least one capsaicinoid source is 0: 100 - 100:0, such as 10:90 - 90: 10, such as 20:80 - 80:20, such as 50:50.

Biofouling in the present context comprises the accumulation of microorganisms, plants, algae, or small animals on surfaces such as wet or submerged surfaces.

The ratio of bitumen to the at least one capsaicinoid source may be 10:90 - 100:0, such as 10:90 - 90: 10, such as 20:80 - 80:20, such as 50:50. I.e., in some embodiments bitumen is the only active ingredient, in other embodiments both bitumen and least one capsaicinoid source are present. The ratio between bitumen and at least one capsaicinoid source may be varied depending on intended use of the composition.

The capsaicinoid source e.g. powder or extract may be chosen to reach a desired scoville factor while providing a desired consistency of the composition.

The capsaicinoid source may for example be powders or extracts e.g. chili powder or chili extract or cayenne extract. The capsaicinoid source(s) preferably have a scoville factor of at least 10.000 SHU. The capsaicinoid source(s) may have a scoville factor of up to 16.000.000 SHU which it that of pure capsaicin. For example, the capsaicinoid source is a chili or pepper powder or extract with a scoville factor of 10.000 - 2.000.000 SHU, such as 20.000- 1000.000 SHU such as at least or up to 20.00, 40.000, 60.000, 80.000, 100.00, 150.000, 200.00, 300.000, 500.000, 600.000, 700.000, 800.000, 900.000 SHU. The higher the SHU factor the lower the concentration of the capsaicinoid source(s) can be in order to achieve an active concentration of capsaicinoids in the composition.

Effective composition may be achieved with a variety of concentrations, and the bitumen and/or at least one capsaicinoid source may be present in a total concentration of 0.1 - 100%, such 0.5 - 99 %, such as 1 - 90% , as 5 - 85% such as 7 - 70 % , such as at least or up to 1, 5, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%. In case of bitumen the concentration may in some embodiments be high such as 70 - 100%, such as or at least 70, 75, 80, 85, 90, 95, 96, 97, 98, 99% up to 100%.

The present invention provides an anti-biofouling composition with reduced toxicity comprising bitumen, where effective anti-biofouling can be achieved with a variety of concentrations of bitumen. Some embodiment of the present invention provide an antibiofouling composition with concentration of bitumen between of 0.1 - 100%, such 0.5 - 99 %, such as 1 - 90% , as 5 - 85% such as 7 - 70 % , such as at least or up to 1, 5, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95%.

Preferably the anti-biofouling composition provided by the present invention is a paint, coating, primer, epoxy, single component product, two component product, overlayer, base coat, topcoat, sealing, cement, plaster, concrete, pulp, glass fibre, composite, plastic or an additive for one/or more of these.

One embodiment of the present invention provides an anti-biofouling composition as a paint or a two component product comprising bitumen in a total concentration of 0.1 - 100 %, such as 5 - 85% such as 7 - 70 % , such as at least or up to 1, 5, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95% or intervals of these. Another embodiment of the present invention provides an anti-biofouling composition e.g. a paint or a two component product comprising bitumen and/or at least one capsaicinoid source a in a total concentration of 0.1 - 100 %, such as 5 - 85% such as 7 - 70 % , such as at least or up to 1, 5, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95% or intervals of these.

One embodiment of the present invention provides an anti-biofouling composition as a material for casting or moulding such as cement, plaster, pulp, glass fibre, composite, plastic and/or concrete comprising bitumen in a total concentration of 0.1 - 90 %, such as 5 - 70%, such as 5 - 40% or at least or up to 1, 5, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 98, 99 % or intervals between any of these. Another embodiment of the present invention provides a composition as a material for casting or moulding such as cement, plaster, pulp, glass fibre, composite, plastic and/or concrete comprising bitumen and/or at least one capsaicinoid source in a total concentration of 0.1 - 90 %, such as 5 - 70%, such as 5 - 40% or at least or up to 1, 5, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 98, 99 % or intervals between any of these. One embodiment of the present invention provides an anti-biofouling composition as dried, hardened and/or cured cement, plaster, concrete, glass fibre, composite, plastic and/or pulp comprising bitumen in a total concentration of 0.1 - 90 %, such as 5 - 50% or at least or up to 1, 5, 10, 12, 15 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 98 or 99 % or intervals between any of these. Another embodiment of the present invention provides an anti-biofouling composition as dried, hardened and/or cured cement, plaster, concrete, glass fibre, composite, plastic and/or pulp comprising bitumen and/or at least one capsaicinoid source in a total concentration of 0.1 - 90 %, such as 5 - 50% or at least or up to 1, 5, 10, 12, 15 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 98 or 99 % or intervals between any of these.

In some embodiments the composition comprises no toxic other additives.

The present also relates to an anti-biofouling system comprising a first composition and a second composition comprising bitumen and/or at least one capsaicinoid source in a concentration of 0.0 - 100 % or at least or up to 1, 5, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 98, 99 % or intervals between any of these.

For example, the system may comprise a base first composition having a first total concentration of bitumen and/or at least one capsaicinoid source and a second composition comprising bitumen and/or at least one capsaicinoid source with a second total concentration of bitumen and/or at least one capsaicinoid source wherein the first and second concentration is the same or different but at least one of the first or second concentrations is above 0, such as above 5% such as above 10% such as at least or up to 1, 5, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 98, 99 % or intervals between any of these.

Total concentration is understood as concentration of bitumen, or the concentration of bitumen plus the concentration of the capsaicinoid source(s).

Concentrations may be given in volume% or weight %. For liquids such as bitumen or extracts % is given in vol% and concentrations for solids such as powders is given in w%. When the composition is produced by adding an additive comprising the active anti-fouling ingredient into another composition, the concentration of the additive may be given in ppw, or parts per weight of the final mixture of the commercially available composition and the additive.

The present invention provides an anti-biofouling composition with reduced toxicity comprising bitumen, where effective anti-biofouling can be achieved with a variety of concentrations of bitumen

One embodiment of the present invention provides an anti-biofouling composition as an additive for paint, coating, primer, epoxy, single component product, two component product, overlayer, topcoat, cement, plaster, pulp, glass fibre, composite, plastic and/or concrete etc. In one embodiment the additive provided by the present invention is a bitumen additive comprising bitumen in a total concentration of 0.1 - 100 %, such as 5 - 100%, or at least or up to 1, 5, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 98 or 99 % or intervals between any of these.

One embodiment of the present invention provides a composition comprising bitumen additive in the amount of 5 parts bitumen additive per 105 parts total composition. Another embodiment of the present invention provides a composition comprising bitumen in the amount of 10 parts bitumen per 110 parts total composition or 1 : 10 ratio bitumen to total composition. Yet another embodiment of the present invention provides a composition comprising additive versus the total composition in a ratio of 5: 105, 1 : 11; 2:12; 3: 13, 4: 14, 5: 15, 55:155.

One embodiment of the present invention provides a composition comprising bitumen additive with the concentration of between 0.1 - 100 % bitumen in the concentration of anywhere between 5: 155 part per weight or ppw and op to 50: 155 parts per weight, in commercially available paint, coating, primer, epoxy, single component product, two component product, overlayer, topcoat, cement, plaster, pulp, glass fibre, composite, plastic and/or concrete etc., where parts per weight stands for total amount of additive per weight in the total weight of the composition after addition of the additive. One embodiment of the present invention provides a composition comprising bitumen and least one capsaicinoid additive with the concentration of between 0.1 - 100 % bitumen and least one capsaicinoid, into a commercially available paint, coating, primer, epoxy, single component product, two component product, overlayer, topcoat, cement, plaster, pulp, glass fibre, composite, plastic and/or concrete etc in the concentration of anywhere between 5:155 part per weight or ppw and op to 50: 155 parts per weight, in., where parts per weight stands for total amount of additive per weight in the total weight of the composition after addition of the additive.

In another embodiment the additive provided by the present invention comprises bitumen and at least one capsaicinoid in a total concentration of 0.1 - 100 %, such as 5 - 100%, or at least or up to 1, 5, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 98 or 99 % or intervals between any of these. In yet another embodiment of the present invention two different additives are provided, comprising capsaicinoid source and bitumen respectively, in the concentration of between of 0.1 - 100 %, such as 5 - 100%, or at least or up to 1, 5, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 98 or 99 % or intervals between any of these.

In another embodiment the additive provided by the present invention comprises bitumen and/or at least one capsaicinoid in a total concentration of 0.1 - 100 %, such as 5 - 100%, or at least or up to 1, 5, 10, 12, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, 98 or 99 % or intervals between any of these.

The system may for example comprise a first composition in form of a primer or base layer composition having a first total concentration of bitumen and/or at least one capsaicinoid source and a second composition e.g. in form of a overlayer, paint, topcoat or sealing comprising bitumen and/or at least one capsaicinoid source with a second concentration.

The system may for example comprise a first composition in form of concrete or cement (or other castable) composition having a first total concentration of bitumen and/or at least one capsaicinoid source and a second composition e.g. in form of a paint, coating, primer, epoxy, single component product, two component product, overlayer, topcoat comprising bitumen and/or at least one capsaicinoid source with a second total concentration.

The system may further comprise a third composition having a third total concentration of bitumen and/or at least one capsaicinoid source. Wherein the first, second and optionally third concentration is 0.0 - 100 % of bitumen and/or at least one capsaicinoid source and wherein at least one of the first, second and third concentration of bitumen and/or at least one capsaicinoid source is larger than 0% preferably from 5% or more.

For example, the system comprises an epoxy primer comprising 0.0 - 100 % of bitumen and/or at least one capsaicinoid source and a paint for care, preparation and/or protection of the submerged surface of marine vessels or structures comprising 0.0 - 100 % of bitumen and/or at least one capsaicinoid source wherein at least one of the primer or paint comprises more than 1% such as more than 5%, such as at least 10% of bitumen and/or at least one capsaicinoid source.

The composition may be applied to the material by brush, paint roll, air gun, nebulizer, impregnation, admixing in dry and/or wet state etc depending on the surface or material the composition is applied to.

The composition may be provided in one or more layers e.g. the composition may be provided in a first, second and/or third layer.

The composition may be provided as a base layer or primer, an active layer and/or as a top coating each for example in the form of one or more of paint, coating, primer, epoxy, single component product, two component products, overlayer, topcoat.

Preferably the composition in the method is a composition as described herein and/or a part of a system also described herein.

The system may also be provided as an additive kit for obtaining the system as described above based on standard commercial products such as paint, coating, primer, epoxy, single component product, two component product, overlayer, topcoat, cement, concrete, plaster, glass fibre, pulp, plastic, composite etc. The kit may be used to add an additive with a composition as described herein to a product such as a commercial product to achieve a product with enhanced resistance to biofouling. The ratio between additive and commercial product may vary depending on intended use, composition of additive and/or the type and physical properties of the commercial product.

One embodiment of the present invention provides a method of producing an antifouling composition, comprising the steps of providing a first composition, wherein the first composition is paint, coating, primer, epoxy, single component product, two component product, overlayer, topcoat, cement, concrete, plaster, glass fibre, pulp or plastic composite; providing a second composition comprising bitumen in the concentration of 0.5 - 100 %; and mixing the two compositions.

The amount of the second composition comprising bitumen can be adjusted for receiving a concentration of bitumen anywhere between 3-100% w/w total composition, such as 3-10%, 5-10%, 5-20%, 10-20%, 15-20%, 3-50%, 3-35%, 5-25%, 10-30%.

Another embodiment of the present invention provides a method of producing an antifouling composition, comprising the steps of providing a first composition, wherein the first composition is paint, coating, primer, epoxy, single component product, two component product, overlayer, topcoat, cement, concrete, plaster, glass fibre, pulp or plastic composite; providing a second composition comprising bitumen in the concentration of 0.5 - 99.5 % and capsaicin source in the concentration of 0.5 - 99.5 % and mixing the two compositions.

The amount of the second composition comprising bitumen can be adjusted for receiving a total concentration of bitumen and capsaicin anywhere between 3-100% w/w total composition, such as 3-10%, 5-10%, 5-20%, 10-20%, 15-20%, 3-50%, 3- 35%, 5-25%, 10-30%. One embodiment of the present invention provides an anti-biofouling system comprising a first composition and a second composition, wherein the first composition is a commercially available paint, coating, primer, epoxy, single component product, two component product, overlayer, topcoat, cement, concrete, plaster, glass fibre, pulp or plastic composite and the second composition being an additive kit, for the first composition, wherein said additive comprises bitumen in the concentration of 0.5 - 100 %.

One embodiment of the present invention provides a method of producing an antibiofouling composition, said method comprising the steps of: providing a first composition, wherein the first composition is paint, coating, primer, epoxy, single component product, two component product, overlayer, topcoat, cement, concrete, plaster, glass fibre, pulp or plastic composite; providing a second composition comprising bitumen in the concentration of 0.5 - 100 %; and mixing the two compositions, wherein the two compositions are provided in the ratio of between 100:5 - 100:50.

Another embodiment of the present invention provides a method according of producing an anti -biofouling composition, said method comprising the steps of: providing a first composition, wherein the first composition is paint, coating, primer, epoxy, single component product, two component product, overlayer, topcoat, cement, concrete, plaster, glass fibre, pulp or plastic composite; providing a second composition comprising bitumen and at least one capsaicin source in total concentration of 0.5 - 100 %; and mixing the two compositions, wherein the two compositions are provided in the ratio of between 100:5 - 100:50.

One embodiment of the present invention provides a method of preventing biofouling, comprising the steps of: providing a composition comprising bitumen, or a composition comprising both bitumen and at least one capsaicin source, applying the composition on and/or in a material wherein the application is carried out in one, two or more identical or different application steps.

The present also relates to a method for reducing biofouling, said method comprising the steps of,

Providing a composition comprising bitumen and/or at least one capsaicinoid source

Applying the composition on and/or in a material and/or material surface wherein the application is carried out in one, two or more identical or different application steps.

Description of the Drawings

Fig. 1 shows three different tests subjects (CS 2 - 4)

Fig. 2 shows three different test subjects (BC 3 - 5)

Fig. 3 shows five different test subjects (C 1 - 4)

Fig. 4 shows three different test subjects (A 2 - 4)

Fig. 5 shows a speed boat screw propeller painted with Hempel Prop NCT before exposure to sea water.

Fig. 6 shows a speed boat screw propeller painted with Hempel Prop NCT after 15 weeks of exposure to sea water.

Fig. 7 shows a speed boat screw propeller painted with Hempel Prop NCT after 15 weeks of exposure to sea water.

Fig. 8 shows a speed boat screw propeller painted with Hempel Prop NCT after 15 weeks of exposure to sea water.

Fig. 9 shows a speed boat screw propeller painted with lOppw (parts per weight) Hempel Prop NCT paint; 2ppw bitumen product and Ippw capsaicin source before exposure to sea water.

Fig. 10 shows a speed boat screw propeller painted with lOppw Hempel Prop NCT paint; 2ppw bitumen product and Ippw capsaicin source after 15 weeks of exposure to sea water.

Fig. 11 shows a speed boat screw propeller painted with lOppw Hempel Prop NCT paint; 2ppw bitumen product and Ippw capsaicin source after 15 weeks of exposure to sea water. Fig. 12a and 12b show test subject CS 1 after respectively 15- and 54-weeks submersion in sea water.

Fig. 13a and 13b show test subject CS 2 after respectively 15- and 54-weeks submersion in sea water.

Fig. 14a and 14b showtest subject CS 3 after respectively 15- and 54-weeks submersion in sea water.

Fig. 15a and 15b show test subject CS 4 after respectively 15- and 54-weeks submersion in sea water.

Fig. 16a and 16b show test subject CS 5 after respectively 15- and 54-weeks submersion in sea water.

Fig. 17a and 17b show test subject CS 6 after respectively 15- and 54-weeks submersion in sea water.

Fig. 18a and 18b show test subject BS 2 after respectively 37- and 70-weeks submersion in sea water.

Fig. 19a and 19b show test subject BS 3 after respectively 37- and 70-weeks submersion in sea water.

Fig. 20a and 20b show test subject BS 4 after respectively 37- and 70-weeks submersion in sea water.

Fig. 21a and 21b show test subject BS 5 after respectively 37- and 70-weeks submersion in sea water.

Fig. 22a and 22b show test subject BS 6 after respectively 37- and 70-weeks submersion in sea water.

Fig. 23a and 23b show test subject BS 7 after respectively 37- and 70-weeks submersion in sea water.

Fig. 24a and 24b show test subject BS 9 after respectively 37- and 70-weeks submersion in sea water.

Fig. 25a and 25b show test subject BS 10 after respectively 37- and 70-weeks submersion in sea water.

Fig. 26a and 26b show test subject C 1 after respectively 22- and 52-weeks submersion in sea water.

Fig. 27a and 27b show test subject C 2 after respectively 22- and 52-weeks submersion in sea water.

Fig. 28a and 28b show test subject C 3 after respectively 22- and 52-weeks submersion in sea water. Fig. 29a and 29b show test subject C 4 after respectively 22- and 52-weeks submersion in sea water.

Fig. 30a and 30b show test subject C 5 after respectively 22- and 52-weeks submersion in sea water.

Fig. 31a and 3 lb show test subject A 1 after respectively 22- and 52-weeks submersion in sea water.

Fig. 32a and 32b show test subject A 2 after respectively 22- and 52-weeks submersion in sea water.

Fig. 33a and 33b show test subject A 3 after respectively 22- and 52-weeks submersion in sea water.

Fig. 34a and 34b show test subject A 4 after respectively 22- and 52-weeks submersion in sea water.

Fig. 35a and 35b show test subject A 5 after respectively 22- and 52-weeks submersion in sea water.

Detailed Description of the Invention

A wide range of tests for surface treatment of submerged subjects has been carried out identifying threshold values for bitumen and capsaicinoid source.

The tests have been carried out on a number of different substrates including steel, wood, aluminium, polished steel and glass fibre plates.

The tests include test where subjects were submerged in sea water (in Denmark) for several weeks in which period the water temperature ranged from approximately 10 to 19.5C.

The test weeks included the months of July and August where a high degree of biofouling including growth of algae and/or barnacles is expected.

The test generally shows that both capsaicinoids and/or bitumen in various concentrations are effective in preventing biofouling growth of algae and/or barnacles.

Bitumen 100% bitumen of various types has been tested and has shown good results in preventing biofouling. The type of bitumen may be selected for best application depending on the surface and means of application.

Paint is in this section understood as paint for care, preparation and protection of the submerged surface of marine vessels or structures, such as commercially available paint or primer suitable for such a purpose.

Tests were carried out with paint mixed with bitumen in concentrations from 3 - 33% weight/weight (50-500 g bitumen in a composition weighting between 1000-1550 g) . The tests showed that Bitumen may be effective from the lowest concentration applied in the initial tests which is 4,7% (1000 g primer with 50 g bitumen), and even more effective when added to a suitable paint as as 1 : 10 ppw (100g bitumen in 1000 g paint) demonstrating that bitumen additive is highly effective from a concentration of 9%.

Similarly, tests were carried out including tests with paint mixed with a capsaicinoid source in form of e.g. cayenne extract or chili pepper extract (chilli pepper extract with f 40.000 SHU and cayenne extract with SHU factor of 500) in concentrations from 3- 33% which all showed effective.

Similarly, no upper limit of the capsaicinoid source has been identified.

A variety of store-bought paints for painting marine vessels was used for the tests.

Suitable products may include products with characteristics of:

Dry film thickness 25- 55 micron

Wet film thickness 60 - 85 micron

Suggested spreading rate 10 - 20 m ² /L

The paints used may be soft or of the type with hard matrix. It may or may not comprise other biologically active additives such as biocides.

It has been found that it is beneficial to apply the composition as provided by the present invention on a suitable pre-treated subject, for ensuring adherence of the composition, such as on top of 1-2 or 3 layers of suitable primer. Furthermore, as it has been discovered that the anti-fouling effect of the composition of the invention does not decrease during long (over 1 year) exposure to sea water, it is seen as beneficial to apply the composition provided by the present invention multiple time.

Experiments

A range of different systems comprising bitumen and/or paint with a capsaicinoid source (either chili powder SHU factor of 40.000 or cayenne extract SHU factor of 500.000) in concentrations from 10% and/or bitumen in a concentration from 10% have been tested showing promising results.

The systems include systems with or without a base layer of epoxy primer, with or without a layer of 100% bitumen, with or without layer of paint comprising capsaicinoid source (here either chili powder or cayenne extract) and/or bitumen.

Results for some of the tests are shown in figures 1 - 4.

Chili powders used has a SHU factor of 40.000 SHU

Cayenne extracts used has a SHU factor of 500.000 SHU

For testing the effect of a composition with limited toxicity comprising bitumen and a capsaicinoid source for reducing growth of biofouling organisms, such as biofilm, algae and/or bryozoans and/or barnacles, a speedboat screw propeller was painted with a composition comprising bitumen and a capsaicinoid source on one side, and with a commercially available paint on the other side. The speedboat screw propeller was then submerged into sea water (in Denmark) on the 6th of August 2022 and kept submerged until the 22nd of October 2022, or for a 11 -weeks’ time period.

The comparison side of the speedboat screw propeller was painted with the commercially available paint Hempel Prop NCT, according to instructions. The other side of the speedboat screw propeller was painted with a composition comprising lOppw paint, with the addition of 2ppw bitumen product (SikaGard ®, product SikaGard-6060, Sika) and Ippw cayenne extract (Cayenne Pepper Extract Organic, product number 7013, Advanced BioTech) with a SHU factor of 500.000 SHU. As throughout the present application, ppw stands for parts per weight and the composition utilized was prepared by adding 200 g bitumen product (SikaGard) and 100 g capsaicinoid source (Cayenne Pepper Extract Organic) into 1000 g of paint (Hempel Prop NCT), resulting in a composition with the weight ratio of 10:2: 1 (paint:bitumen:capsaicin) or a composition with 15,5% bitumen product and 7,7% capsaicin source.

The results can be seen in Fig. 5-11.

Figure 5. is a picture of the side of the speedboat screw propeller that was painted with the commercially available paint Hempel Prop NCT before being exposed to sea water, where arrows marked as (a), (b) and (c) pointing to different surface areas of the propeller. Figures 6, 7 and 8. are picture that show the same side of the speedboat screw propeller as demonstrated in figure 5, after being exposed to sea water for 11 weeks. As shown by the arrows a, b and c, the surface of the propeller has clear biofouling, as there are seen growth of unspecified types of biofouling organisms, such as algae and/or bryozoans and/or barnacles.

Figure 9. is a picture of the other side (than displayed in figure 5) of the speedboat screw propeller, painted with a composition with lOppw Hempel Prop NCT paint; 2ppw bitumen product (SikaGard ®, product SikaGard-6060, Sika) and Ippw cayenne extract (Cayenne Pepper Extract Organic, product number 7013, Advanced BioTech), before being exposed to sea water. As in figure 5, arrows marked as (a), (b) and (c) points to different surface areas of the propeller.

Figures 10 and 11 show the same side of the speedboat screw propeller as demonstrated in figure 9, after being exposed to sea water for 11 weeks. The pictures in figures 10 and 11 demonstrate significantly less growth of biofouling organism than the detectable in the pictures of figures 6-8.

This demonstrates that a composition with 15,5% bitumen product and 7,7% capsaicin source is more effective preventing bio-fouling than the same composition without addition of bitumen and capsaicin souse. Experiment 2: Test series CS.

For testing anti-fouling resistance of different surface treatments, number of rough glass fibre plates test subjects were painted/surf ace-treated with different compositions and then submerged in sea water.

All SC test subjects were submerged on the 10.03.2022. Table 1 below lists different compositions applied on different test subjects. The test subjects were photographed on the 31st of May 2022 (A), after 10 weeks of submersion, again on the 10. July 2022 (B), after 15 weeks of submersion and finally on the 23. Marts 2023 (C) after 54 weeks of submersion. Colum’s A, B and C in table 1 refer to the no. of the figure displaying the picture taken of each test subjects on 31.05.2022; 10.07.2022 and 23.03.2023 respectively. If not otherwise specified, the subjects were utilized without any surface pre-treatment.

The basis paint utilized was the commercially available self-polishing antifouling paint Hempel Mille NCT, the bitumen product was SikaGard ®, product SikaGard-6060, the capsaicinoid source was a chilli pepper powder with SHU factor of 40.000 SHU and a commercially available 2-component epoxy primer was used on subjects CS 4; CS 5 and CS 6. As throughout the current application, the amount of different components of the compositions applied are defined by ppw, that is parts per weight. Hence the composition used on test subject CS 1 was prepared by mixing 1000 g paint, 100 g SikaGard (bitumen product) and 100 g chili pepper power with SHU factor of 40.000 SHU, thus resulting in a composition with lOppw paint, Ippw bitumen product and Ippw capsaicinod product or a composition with the bitumen and capsaicionid source in the concentration of 8,3% each.

The results can be seen in figure 1 and figures 12-17.

Table 1.

It seems that the best results are subjects CS 5 and CS 6, that both comprise a use of a composition with 9.1% bitumen.

Experiment 3: Test series BC.

A wide range of tests for surface treatment of submerged subjects was carried out on a number of different substrates including steel, wood, aluminium, polished steel, bricks and glass fibre plates.

All BC test subjects were submerged in sea water on the 17th of September 2021. Table 2 below lists different subjects utilized and the composition applied on each test subject. Pictures were taken of the test subjects on the 31. May 2022 (A), after 31 weeks of submersion, again on the 10. July 2022 (B), after 37 weeks of submersion and finally on the 23. Marts 2023 (C) after almost 70 weeks of submersion. Colum’s A, B and C in table 2 refer to the no. of the figure displaying the picture taken of each test subjects on 31.05.2022; 10.07.2022 and 23.03.2023 respectively. If not otherwise specified, the subjects were painted without any surface pre-treatment.

The paint utilized was the commercially available self-polishing antifouling paint Hempel Mille NCT, the bitumen product was SikaGard ® and a commercially available 2-component epoxy primer was used on subjects BC 4 and BC 9. As throughout the current application, the compositions are defined by ppw meaning parts per weight. Hence the composition applied on test subject BC 3 was prepared by adding 100 g bitumen product (SikaGard) into 1000 g paint (Hempel Mille NCT) (1 part weight bitumen product against 10 parts weight paint), or a composition with bitumen in the concentration of 9.1 % w/w.

The results can be seen in figure 2 and figures 18-25.

Table 2.

There is significant difference between test subjects BC 2 and BC 3; BC 6 and/or BC 10 respectively, demonstrating that concentration as low as 9.1% of bitumen is highly effective. It is therefore seen that adding only 1 : 10 ppw of bitumen will increases the anti-fouling effect of a commercially available anti-biofouling paint significantly. The results further demonstrate that a concentration down to only 9.1 % bitumen is highly effective also after 70 weeks of exposure to sea water.

On the other hand, there does not appear to be considerable increase in effect with higher concentration of bitumen, as there is minimal difference between test subjects BC 3 and BC 5 (9.1 % and 16.7 % bitumen respectively).

Experiment 4: Test series C. For assessing the effect of different concentrations of bitumen on bio-fouling, five test subjects of stainless steel were treated with compositions comprising a commercially available paint with different concentration of bitumen. All the C test subjects were submerged in sea water on the 6th of February 2022. Table 3 below lists different compositions applied on each test subject. The test subjects were inspected and photographed on the 31. May 2022 (A), after 17 weeks of submersion, again on the 10. July 2022 (B), after 22 weeks of submersion and finally on the 23. Marts 2023 (C) after over a year of submersion. Colum’s A, B and C in table 3 refer to the no. of the figure displaying the picture taken of each test subjects on 31.05.2022; 10.07.2022 and 23.03.2023 respectively.

All the C test subjects were first treated with a two-component epoxy primer, for ensuring better adhesion of the applied paint. They were thereafter all painted with a commercially available antifouling paint, with varying amount of bitumen product added into the paint before application. The commercially available paint utilized was the self-poli shing antifouling paint Hempel Mille NCT and the bitumen product was SikaGard ®, product SikaGard-6060.

As throughout the current application, the concentration or amount of different components of the compositions applied are defined by weight ratio, or ppw meaning parts per weight. Hence the composition applied on test subject C 1 was prepared by adding 100 g of the bitumen product (SikaGard) into 1000 g of paint (Hempel Mille NCT), resulting in a composition comprising 1 part weight bitumen product against 10 parts weight paint or a concentration of 9.1 % bitumen.

The results can be seen in figure 3 and figures 26-30.

Table 3.

Again the results demonstrate that concentration of bitumen of as low as 9.1 % is highly effective and that there does not seem to be necessary to utilize higher concentrations of bitumen, as there is not a significant difference between the results.

Experiment 5: Test series A,

For assessing the effect of different concentration of capsaicioid on bio-fouling, five test subjects of stainless steel were treated with compositions comprising a commercially available paint with different concentration of capsaicinoid.

All the A test subjects were submerged in sea water on the 6th of February 2022. Table 4 below lists different compositions applied on each test subject. The test subjects were visually inspected and photographed on the 31. May 2022 (A), after 17 weeks of submersion, again on the 10. July 2022 (B), after 22 weeks of submersion and finally on the 23. Marts 2023 (C) after over a year of submersion. Colum’s A, B and C in table 4 refer to the no. of the figure displaying the picture taken of each test subjects on 31.05.2022; 10.07.2022 and 23.03.2023 respectively.

All A test subjects were first treated with a two-component epoxy primer, for ensuring better adhesion of the applied paint. They were thereafter all painted with a commercially available antifouling paint, with varying amount of capsaicin product mixed to the paint.

The commercially available paint utilized was the self-poli shing antifouling paint Hempel Mille NCT and the capsaicin product was Cayenne Pepper Extract Organic, product number 7013, Advanced BioTech, with a SHU factor of 500.000 SHU. As throughout the present application, ppw stands for parts per weight, hence the composition applied on test subject A 1 after the application of the two component epoxy primer was prepared by adding 100 g of the capsaicin product (Cayenne Pepper Extract Organic) into 1000 g of paint (Hempel Mille NCT), resulting in a composition with a lOppw paint and Ippw capsaicin product or a weight ratio of 10: 1 between paint and capsaicin product, or a composition with a concentration of 9.1% capsaicin source.

The results can be seen in figure 4 and figures 31-35.

Table 4.

It is seen that as expected capsaicin product provides anti-fouling effect in concentrations as low as 9,1 %. However, if figures 31b; 32b; 33b; 34b and 35b are compared with figures 26b; 27b; 28b; 29b and 30b respectively, it is seen that while the anti-biofouling effect of bitumen does not seem to decrease over time, the antibiofouling effect of capsaicin does.