A Fouling Control Composition Comprising a Polymer Comprising Silyl Ester Functional Groups and Quaternary Ammonium/Phosphonium Groups

Abstract

The present invention relates to a polymer comprising (a1) silyl ester group(s) and (a2) quaternary ammonium group(s) and/or quaternary phosphonium group(s), said quaternary ammonium groups and/or quaternary phosphonium groups being neutralised by counter-ions, wherein the counter-ions consist of the conjugate base of an acid having an aliphatic, aromatic, or alkaryl hydrocarbyl group. The invention further relates to a fouling control coating composition comprising said polymer, a method of protecting a man-made structure immersed in water from fouling, and a substrate or structure coated with the fouling control coating composition.

Claims

1. A polymer comprising: (a1) silyl ester group(s), and (a2) quaternary ammonium group(s) and/or quaternary phosphonium group(s), said quaternary ammonium groups and/or quaternary phosphonium groups being neutralised by counter-ions, wherein the counter-ions consist of the conjugate base of an acid having an aliphatic, aromatic, or alkaryl hydrocarbyl group.

2. The polymer of claim 1, wherein the silyl ester groups (a1), and/or the quaternary ammonium groups and/or quaternary phosphonium groups (a2), are located on side chains pendant to the polymer backbone.

3. The polymer of claim 1 wherein the polymer is formed from at least one (meth)acrylic monomer comprising the silyl ester group(s) (a1) and at least one (meth) acrylic monomer comprising the quaternary ammonium group(s) and/or quaternary phosphonium group(s) (a2).

4. The polymer of claim 3 wherein the weight ratio of the (meth) acrylic monomers comprising silyl ester groups to (meth)acrylic monomers comprising quaternary ammonium groups and/or quaternary phosphonium groups used to form the polymer ranges from 1:99 to 85:16, preferably from 5:95 to 60:40, more preferably from 12:88 to 47:53.

5. The polymer of a claim 3 wherein the polymer is also formed from one or more other vinyl polymerisable monomers.

6. The polymer of claim 1 wherein the conjugate base of the acid comprises an aliphatic, aromatic, or alkaryl hydrocarbyl group comprising 6 or more carbon atoms.

7. The polymer of claim 1 wherein the conjugate base of the acid is a conjugate base of a sulphonic acid.

8. The polymer of claim 1, wherein the counter-ions of (a2) comprise less than 50 carbon atoms.

9. The polymer of claim 1 wherein the silyl ester group(s) (a1) are present on side chain(s) according to the Formula (I): ##STR00010## wherein A is divalent —C(O)— or —S(O).sub.2O— group, n is 0 or an integer of 1 to 50, and R.sub.1, R.sub.2, R.sub.3, R.sub.4, and R.sub.5 are each independently selected from the group consisting of optionally substituted C.sub.1-20-alkyl, optionally substituted C.sub.1-20-alkoxy, optionally substituted C.sub.1-20 aryl, and optionally substituted C.sub.1-20 aryloxy.

10. The polymer of claim 9, wherein n=0 and R.sub.3, R.sub.4, and R.sub.5 are the same or different and represent methyl, isopropyl, n-butyl, isobutyl, ethyl, n-propyl, t-butyl or phenyl.

11. A fouling control coating composition comprising the polymer of claim 1 and an ingredient having biocidal properties for aquatic organisms.

12. The fouling control coating composition of claim 11, further comprising (a) a rosin material and/or (b) a non-hydrolysing, film-forming polymer.

13. A method of protecting a man-made structure immersed in water from fouling by applying the fouling control coating composition as defined in claim 11 to the man-made structure, allowing the fouling control coating composition to form a coating and then immersing the coated man-made structure in water.

14. A substrate or structure coated with the fouling control coating composition according to claim 11.

Description

EXAMPLES

Example 1—Preparation of the Polymer in Accordance with the Invention

[0096] First the (a2) monomer was prepared in the following manner: Dimethylaminopropyl methacrylamide (192.1 g), dimethylcarbonate (179.6 g) and methanol (208 g), were placed in a stainless steel, high pressure reaction vessel. The sealed vessel was heated to 125° C. for 4 hours. The cooled solution was filtered and dried in vacuo after addition of methanol (150 g). The resulting viscous amber liquid, consisting substantially of the corresponding alkyltrimethyl ammonium carbonate (244.7 g) was diluted with xylene (200 g) and placed in a 2 L round bottom flask. To this was added at room temperature with stirring over 30 minutes a solution of dodecylbenzenesulphonic acid (244.7 g) in xylene (200 g), and stirring was continued overnight to provide a solution of the sulphonic acid-capped quaternised monomer in xylene.

[0097] To a stirred polymerisation reaction vessel containing xylene (372.3 g) at 85° C. was added a solution of monomers consisting of a solution of the sulphonic acid-capped quaternised monomer prepared as described above (237.2 g), isobornyl methacrylate (217.6 g), butyl methacrylate (139.2 g), tri-isopropylsilyl methacrylate (59.2 g) and 2,2′-azodi(2-methylbutyronitrile) (AMBN) initiator (4.7 g) in xylene (42.4 g) at constant rate over 5 hours. The temperature was increased to 95° C. and a solution of AMBN (2.35 g) in xylene (21.15 g) was added and the reaction vessel was maintained at this temperature for 2 hours. The reaction vessel was cooled to room temperature to provide the polymer of Example 1.

Example 2—Preparation of a Comparative Polymer (Comprising (a2) but No (a1))

[0098] To a stirred polymerisation reaction vessel containing xylene (162.9 g) and butanol (162.9 g) at 85° C. was added a solution of monomers consisting of a solution of the sulphonic acid-capped quaternised monomer prepared as described in Example 1 above (474.5 g), isobornyl methacrylate (217.6 g), butyl methacrylate (139.2 g) and 2,2′-azodi(2-methylbutyronitrile) (AMBN) initiator (4.7 g) in xylene (42.4 g) at constant rate over 5 hours. The temperature was increased to 95° C. and a solution of AMBN (2.35 g) in xylene (21.15 g) was added and the reaction vessel was maintained at this temperature for 2 hours. The reaction vessel was cooled to room temperature to provide the polymer of Example 2.

Example 3—Preparation of a Comparative Polymer (Comprising (a1) but No (a2))

[0099] To a stirred polymerisation reaction vessel containing xylene (441.9 g) and butanol (441.9 g) at 85° C. was added a solution of monomers consisting of tri-isopropylsilyl methacrylate (125.0 g), isobornyl methacrylate (459.3 g), butyl methacrylate (293.8 g) and 2,2′-azodi(2-methylbutyronitrile) (AMBN) initiator (9.9 g) in xylene (44.7 g) and butanol (44.7 g) at constant rate over 5 hours. The temperature was increased to 95° C. and a solution of AMBN (5.0 g) in xylene (22.35 g) and butanol (22.35 g) was added and the reaction vessel was maintained at this temperature for 2 hours. The reaction vessel was cooled to room temperature to provide the polymer of Example 3.

Example 4—Preparation of a Fouling Control Coating Composition in Accordance with the Invention

[0100] The following materials were mixed in the stated amounts by weight using a high speed disperser to form an fouling-control paint according to the invention

TABLE-US-00001 Name Description Wt % Polymer of example 1 Binder 23 Chlorinated paraffin Plasticiser 5 (Cereclor 48, Ineos Chlor) Copper pyrithione (Lonza) Biocide 4 Iron oxide (Bayferrox 130BM) Pigment 7 Zinc oxide (Larvik) Pigment 12 Cuprous oxide (American Chemet) Biocide 40 Polyamide wax Thixotrope 2 (Disparlon A600-020X, Kusumoto Chemicals) Xylene Solvent 7

Examples 5 and 6—Preparation of Comparative Fouling Control Coating Compositions

[0101] Comparative fouling control coating compositions were made as described above for Example 4 except the polymer of Example 1 was substituted with the polymers of Example 2 and 3. Comparative fouling control composition 5 was formulated with the polymer of Example 2, and comparative fouling control composition 6 was formulated with the polymer of Example 3).

Antifouling Tests

[0102] The antifouling performance of Coating compositions Examples 4, 5 and 6 were compared by applying each of the compositions to a 60×60 cm marine plywood panel by roller to give a dry film thickness of about 150 microns. The boards had been pre-primed with Interprotect epoxy primer (International Paint Ltd). Each coating was allowed to cure fully under ambient conditions before the start of testing.

[0103] Test panels were simultaneously immersed in waters at Burnham (UK) and also simultaneously immersed in natural tropical marine waters at a depth of 0.54 to 1.0 m in Changi, Singapore where growth is known to be severe. The panels were periodically removed from the water to be photographed and the extent of fouling on the coatings was assessed prior to re-immersion of the panels.

TABLE-US-00002 Total % coverage of fouling Example 4 Example 5 Example 6 Location (a1) + (a2) (only (a2)) (only (a1)) Burnham (UK)   0% 8.0% 8.0% 5 months Changi, Singapore 27.0% 47.0% 48.0% 8 months

[0104] After 5 months in the UK, and 8 months in Singapore waters, the coatings formed from Example 4 exhibited less fouling than the coatings formed from Examples 5 and 6.