HK1123319B - Use of a combination of substances to prevent biofouling organisms - Google Patents

Description

Prevention of biofouling organisms by means of a combination of substances

Cross Reference to Related Applications

Priority of U.S. provisional application No. 60/705321, filed on 4.8.2005, the disclosure of which is incorporated herein by reference.

Background

Technical Field

The present invention relates to the use of a combination of selected substances in a coating to simultaneously prevent the attachment and growth of different fouling organisms such as barnacles and algae.

Description of the prior art

Biological growth (or biofouling) on marine equipment or vessels is a significant problem that is common to the shipping industry and owners of marine equipment, vessels, and ships. Untreated hulls quickly accumulate marine plant and animal fouling, which significantly increases the friction of the hull against the water and increases fuel consumption. Moreover, other marine industries and equipment, such as aquaculture installations and oil/gas sea surface equipment and plants, also have significant problems with marine biofouling.

One way to prevent marine biofouling organisms is to apply a coating containing toxic content, such as tributyltin oxide (TBT) or copper. However, the use of marine coatings with such contents has been shown to cause significant damage to marine ecosystems including plant species, animal species and humans (1, 2). Many countries and international organizations have therefore promulgated limitations and bans on these applications and are expected to impose even stronger limitations. The sale and application of TBT antifouling was agreed to stop at the international maritime association antifouling systems conference in month 10 2001. Treaty calls for banning applications from 1/2003 and completely banned on the hull by 1/2008.

Therefore, there is interest in finding new solutions to reduce the levels of metals and metal oxides in coatings to prevent marine biofouling organisms and eventually replace them completely (3-5).

Mechanical removal of marine surfaces has been described as an alternative to toxins and biocides. In particular, water jet cleaning and mechanical cleaning with brushes are used. However, most of these methods are labor intensive and costly.

Since international paint companies have deleted paints containing tributyltin oxide (TBT) from the product catalog, the disabling of TBT has been achieved. Instead, the basic biocide is copper, copper oxide or other copper-based compound. However, when the use of copper compounds is reduced in concentration for ecological reasons, these coatings require secondary biocides against barnacles and algae to achieve an effect acceptable to boat owners and other types of marine industries. Furthermore, coatings with specific novel compounds against barnacles, such as medetomidine ("Catemine 1"), as described below, require the supplementation of auxiliary compounds against algae.

Along the swedish west coast and along the coast of the north atlantic ocean, barnacles and different kinds of algae are particularly problematic. Mature barnacles are a fixed crustacean characterized by a centimeter-sized cone shape and a surrounding layer of calcified discs. The mechanical strength of the animal's adsorbed solid surface is very high and thus it is difficult to mechanically remove barnacles from the solid surface. The animal undergoes different stages of development, namely free-swimming larvae, with the last larval stage being referred to as the cyprid stage. The cyprid screens solid surfaces suitable for attachment with the aid of neurites. By "adherent gel" is meant the glans mucus secreted from the particular gland above the protrusion to allow the animal to adhere to the solid surface. After attachment, the animal undergoes metamorphosis into an adult and sessile animal. One of the first organisms that fouled when using old copper bleed paint with high copper concentrations was barnacles.

Further, algae are relatively insensitive to copper and the amount of copper leaching required to inhibit fouling of algae is high. Thus, copper-containing marine antifouling paints are "aided" with more specific algicides produced by certain manufacturers. The algicide can inhibit zoospore fouling or inhibit photosynthesis. Both methods result in a reduction in algal fouling.

Various compounds have been previously disclosed and employed to interfere with the nerve signaling or other specific activity of marine fouling organisms such as barnacles or tubeworms. For example, U.S. patent No. 6,762,227 discloses the use of medetomidine (Catemine1) and other substances. Furthermore, Swedish patent application No. 0300863-8 discloses the use of spiroimidazolines (Catemine3) for the same purpose. However, the use of such products is not or less effective for algae. For example, Catemine1(6) has a specific effect on barnacle cyprids but is not effective for algae growth because of the lack of the corresponding target protein in algae. This also applies to the other different pharmacologically active substances (7-11).

There are several methods of preventing algae, including the use of copper and other metals at relatively high concentrations. Algicides have been generally invented as herbicides and photosynthesis-inhibitors, such as Diuron [3- (3, 4-dichlorophenyl) -1, 1-dimethylurea ] produced by DuPont Agricutural products Wilmington, USA, and Irgarol1051 (2-methylthio-4-tert-butylamino-6-cyclopropylamino-s-triazine) produced by Tarrytown, Ciba Inc, N.Y., USA. A more common strategy is to employ fungicides such as zinc pyrithione [ bis (1-hydroxy-2 (1H) -pyridylthio-sulfate-O, S) -, (T-4) -zinc ], copper pyrithione (copperpyrone) [ bis (1-hydroxy-2 (1H) -pyridylthio-sulfate-O, S) -, (T-4) -copper ], tolylfluanim [ N- (dichlorodifluoromethylthio) -N ', N' -dimethyl-N-p-toluenesulfonamide ] produced by Bayer Chemicals, Pittsburgh, Pa., Bayern., USA, Zinc (ethylenebisdithiocarbamate) produced by FMC Inc, Zinram [ zinc bis (dimethylthiocarbamate) (3-5) or quaternary ammonium compounds from Taminco. The third strategy is to use toxic compounds with short half-lives, such as SeaNine [4, 5-dichloro-2-n-octyl-3 (2H) -isothiazolone ] and related compounds (12-13) manufactured by Rohm and Haas corporation, philadelphia, pa.

In recent years, there has been a growing interest in a strategy to find natural substances that can be used as antifouling agents in paints. These substances are endogenous to different marine invertebrates to protect their surfaces from fouling. Several compounds have been isolated and characterized and their anti-fouling activity tested (4).

However, there is a need to find compounds or combinations of compounds for use in antifouling coatings in order to make the coatings more effective against both types of organisms, such as barnacles and algae, without the negative ecological effects of coatings with high concentrations of metal compounds.

Disclosure of Invention

The invention relates firstly to an ecologically acceptable method for preventing the growth of neuromuscular larvae and algae on solid surfaces. Older species of biofouling coatings with high concentrations of metals are able to combat barnacles and algae, but have several negative environmental effects. Reducing the concentration of the reactive metal compound in such a coating would render it ineffective against algae and barnacles. More new types of ecological compounds that have been or are proposed to be anti-fouling are more effective against one or the other group of fouling organisms.

The present invention solves this problem by providing new effective anti-fouling agent compositions such as medetomidine (Catemine1) (+/4-4- [1- (2.3-dimethylphenyl) ethyl ] -1H-imidazole) and Igarol (2-methylsulfanyl 4-tert-butylamino-6-cyclopropylamino-s-triazine), or medetomidine and dichlofluanid, as well as other compositions.

Other objects and features of the present invention will become apparent from the following description.

Detailed description and preferred embodiments of the invention

The principle of the method of the invention is to combine substances capable of interfering or blocking target cell nerve signals in the inside of the cyprid with anti-algae compounds, such as zinc pyrithione and copper pyrithione, tolylfluanid and dichlofluanid. Herbicides such as Diuron and Irgarol, or more commonly biocides such as SeaNine or EcoNea (2- (p-chlorophenyl) -3-cyano-4-bromo-5-trifluoromethylpyrrole) produced by janssen pharmaceutical of titussville, nj.

By using a low toxicity biodegradable compound as an auxiliary biocide, it is possible to reduce non-biodegradable copper in the coating. For example, environmentally friendly compounds are utilized to interfere with nerve signaling in barnacles and the like while maintaining low concentrations of metal compounds in biodegradable algicide compositions, and thus have substantially little negative impact on the environment. An important practical and industrial use of the present invention is to mix these materials into a polymer matrix (coating). The polymer (paint) is then applied to the hull of a ship and in a marine environment these substances will be slowly released from the polymer. The attached cyprid will thus be disturbed and unable to attach. Algae growth can be prevented by adding an auxiliary algicide. The present invention includes the use of relatively low toxicity pharmacological agents, such as medetomidine, which can interfere with, mimic or block the nerve signaling processes of cells of some organisms, such as barnacles, during attachment to solid surfaces, and which can prevent the attachment and growth of algae in combination with other agents that inhibit the attachment or growth of algae. A direct application of the present invention is to add a substance to the base polymer coating which is then applied to the hull of a ship.

Example 1

Spore germination assays are commonly used to test the effectiveness of algicides. Algae were collected from the field and cultured in the laboratory. After induction of spore formation, the test bottle is placed, the compound to be tested is dissolved in pasteurized deep sea water, the test bottle is placed for several hours (2-3 hours) in the dark so that the transplanted spores are uniformly distributed in the bottle, and then the water in the compound to be tested is removed and a culture medium is added. Spores were placed in fluorescent lamps (50 μ M-2s-l (PAR)) and germinated in culture medium for 7 days, 16h light and 8h dark each day, with the medium being changed once a day.

According to the present invention, Catemine1 was combined with an effective anti-algae compound such as dichlofluanid (table 1), SeaNine (table 2), Irgarol (table 3) and Diuron (table 4), and all of these different products were tested for their effect against barnacles and algae in combination with Catemine1 (either two compounds or one alone). The adopted detection is the detection of settlement and attachment rate of the larvae of the acinus and the detection of germination of algae.

By adopting such a combination, it is possible to prevent fouling of barnacles and a large amount of algae and to improve the overall effect of the antifouling paint at the same time.

TABLE 1

Catemine1(nM)	Antibacterial agent (mu g/ml)	Barnacle biofouling (% attached)	Ulva biofouling (% survival)
				0	0	100	100
0.1	0	100	100
				1	0	10	100
10	0	0	100
				100	0	0	100
				0	0	100	100
0	0.1	100	100
				0	1	50	90
0	10	25	10

0	100	0	0
0	0	100	100
				0.1	0.1	100	100
1	1	10	90
				10	10	0	10
100	100	0	0

TABLE 2

Catemine1(nM)	SeaNine(nM)	Barnacle biofouling (% attached)	Ulva biofouling (% survival)
				0	0	100	100
0.1	0	100	100
				1	0	10	100
10	0	0	100
				100	0	0	100
				0	0	100	100
0	0.1	100	100
				0	1	50	50
0	10	10	10
				0	100	0	0
				0	0	100	100
0.1	0.1	100	100
				1	1	10	50
10	10	0	10
				100	100	0	0

TABLE 3

Catemine1(nM)	Irgarol(nM)	Barnacle biofouling (% attached)	Enteromorpha biofouling (% survived)
				0	0	100	100
0.1	0	100	100
				1	0	10	100
10	0	0	100
				100	0	0	100
				0	0	100	100
0	0.1	100	100
				0	1	100	100
0	10	100	50
				0	100	100	0
				0	0	100	100
0.1	0.1	100	100
				1	1	10	100
10	10	0	50
				100	100	0	0

TABLE 4

Catemine1(nM)	Diuron(μM)	Barnacle biofouling (% attached)	Ulva biofouling (% survival)
				0	0	100	100
0.1	0	100	100
				1	0	10	100
10	0	0	100
				100	0	0	100
				0	0	100	100
0	0.1	100	100
				0	1	100	90
0	10	100	50
				0	100	100	0
				0	0	100	100
0.1	0.1	100	100
				1	1	10	90
10	10	0	50
				100	100	0	0

While the invention has been described in conjunction with specific embodiments, it is intended that various changes, modifications, and embodiments be practiced, and accordingly, all such changes, modifications, and embodiments are to be considered as within the spirit and scope of the present invention.

Reference to the literature

1. "tributyltin oxide status in the coast over thirty years, particularly in the acasetron gulf of france" environmental polarization 93(2)195- "203, 1996 written by Ruiz, j.m., Bachelet, g., Caumette, p.anddonard, o.f.x.

2. "pharmacological properties of tributyltin oxide in vitro and in vivo", written by Mizuhashi, S., Ikegaya, YandMatsuki, N. "environmental toxicological 8, 205-Pharmacology 212, 2000.

3. "organotin antifouling paints and substitutes therefor" appl. organic. chem.17, 81-105, 2003 written by Omae, i.

4. "general properties of tin-free antifouling paints" chem.rev.103, 3431-.

5. Written by Yebra, d.m., Kiil, s.anddam-Johansen, k, "the development of efficient and environmentally friendly antifouling coatings in the past, present and future," progress organic coatings.50, 75-104, 2004.

6. From DahlstrmM，MartenssonLGE，JonssonPR，Am"inhibition of adhesion of surface-active adrenergic receptors to dense barnacle cyprid larvae" written by ebrantT, elwing h. "biofoulding 16, 191-203, 2000.

7. "effect of calmodulin inhibitor to prevent barnacle larva attachment" written by YamamotoH, tachibana a, SaikawaW, nanogam, MatsumuraK, fusitan. j.exp.zool.80: 8-17, 1998.

8. "neurotransmitter blockers written by YamamotoH, SatuitoCG, YamazakiM, NatoyamaK, TachibanaA, fusetanin, as antifouling agents to prevent pericarp planktonic larvae and mediterranean mussels" Biofouling 13: 69-82, 1998.

9. The "role of dopamine and 5-hydroxytryptamine in the attachment of periwinkle larvae" written by Yamamoto, h., Shimizu, k., Tachibana, a.andfusetani, N "j.exp.zoo.284, 746-.

10. "acetylcholine involved in the attachment of the striated barnacles" written by faimli, m., Falugi, C, Gallus, l., Piazza, v.andtagliafaro, C. "biofolling 19suppl.213-20, 2003.

11. "pharmaceutical antifouling agents" written by Rittschof, d., Lai, c.h., Kok, l.m. andteo, sx: concept and principle "Biofouling 19Suppl.207-12, 2003.

12、http://www.janssenpharmaceutica.be/pmp/Pages/database/$Econea/$Leaflets/Econea％20028updPIS.pdf。

13. "SeaNine antifouling agent" written by Jacobson, a.h. and willingham, g.l: an environmentally acceptable alternative to organotin antifoulants "the scientific soft top environment258, 103-.

Claims (6)

1. A method of preventing biofouling of a substrate by a marine biofouling organism, the method comprising applying to the substrate a protective coating comprising a) a substance that affects glandular barnacle nerve signals, and b) an algae inhibiting substance; wherein the substance affecting the glandular barnacle nerve signals is medetomidine and the algae inhibiting substance is selected from the group consisting of 3- (3, 4-dichlorophenyl) -1, 1-dimethylurea, 2-methylsulfanyl-4-tert-butylamino-6-cyclopropylamino-S-triazine, bis (1-hydroxy-2 (1H) -pyridylthio-O, S) - (T-4) -zinc, bis (1-hydroxy-2 (1H) -pyridylthio-O, S) - (T-4) -copper, N- (dichlorodifluoromethylthio) -N ', N' -dimethyl-N-p-toluenesulfonamide, N '-dimethyl-N-phenylthioamide, N' -dimethyll-N-propylthionamide, N-butylthionamide, N-, 4, 5-dichloro-2-n-octyl-3 (2H) -isothiazolone, and 2- (p-chlorophenyl) -3-cyano-4-bromo-5-trifluoromethylpyrrole.

2. The method of preventing marine biofouling according to claim 1, wherein the protective coating further comprises ortho-xylene.

3. The method of preventing marine biofouling according to claim 1, wherein the protective coating further comprises a marine coating.

4. A product for preventing biofouling of a substrate by a marine biofouling organism, the product comprising a protective coating comprising a) a substance that affects the signaling of the nerval nerve of the adenoid barnacles, and b) an algae inhibiting substance; wherein the substance affecting the glandular barnacle nerve signals is medetomidine and the algae inhibiting substance is selected from the group consisting of 3- (3, 4-dichlorophenyl) -1, 1-dimethylurea, 2-methylsulfanyl-4-tert-butylamino-6-cyclopropylamino-S-triazine, bis (1-hydroxy-2 (1H) -pyridylthio-O, S) - (T-4) -zinc, bis (1-hydroxy-2 (1H) -pyridylthio-O, S) - (T-4) -copper, N- (dichlorodifluoromethylthio) -N ', N' -dimethyl-N-p-toluenesulfonamide, N '-dimethyl-N-phenylthioamide, N' -dimethyll-N-propylthionamide, N-butylthionamide, N-, 4, 5-dichloro-2-n-octyl-3 (2H) -isothiazolone, and 2- (p-chlorophenyl) -3-cyano-4-bromo-5-trifluoromethylpyrrole.

5. The product for preventing marine biofouling according to claim 4, wherein the protective coating further comprises ortho-xylene.

6. The product for preventing marine biofouling according to claim 4, wherein the protective coating further comprises a marine coating.