Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
  • B63B—SHIPS OR OTHER WATERBORNE VESSELS; EQUIPMENT FOR SHIPPING 
  • B63B59/00—Hull protection specially adapted for vessels; Cleaning devices specially adapted for vessels
  • B63B59/04—Preventing hull fouling
• • C—CHEMISTRY; METALLURGY
  • C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
  • C09D—COATING COMPOSITIONS, e.g. PAINTS, VARNISHES OR LACQUERS; FILLING PASTES; CHEMICAL PAINT OR INK REMOVERS; INKS; CORRECTING FLUIDS; WOODSTAINS; PASTES OR SOLIDS FOR COLOURING OR PRINTING; USE OF MATERIALS THEREFOR
  • C09D5/00—Coating compositions, e.g. paints, varnishes or lacquers, characterised by their physical nature or the effects produced; Filling pastes
  • C09D5/16—Antifouling paints; Underwater paints
  • C09D5/1693—Antifouling paints; Underwater paints as part of a multilayer system

Definitions

• the present invention relates to an anti-fouling treatment for protecting boats, ships, buoys and other structures (hereinafter referred to generally as vessels and marine structures) exposed to sea or fresh water against fouling by weed, slime, barnacles and other marine growth and organisms.
• Hulls have been built using copper-nickel plate as an exterior surface. Steel hulls have been clad with copper nickel plate by a system of welding. Hulls have also been built using plate which is a combination of steel and copper-nickel rolled together to form a single material. These methods have shown the success of copper-nickel as an outer layer for a hull with respect to erosive resistance, corrosion resistance, and bio-fouling resistance. Nevertheless, they are debatable techniques economically because of general expense and apply, in the main, to heavy duty shipping and structures.
• the mesh needs to be of a fineness such that some metallic material is visible every 0.1" (2.54mm) or so. This method has the advantage that it can be retrospectively fitted to an existing surface. It is also relatively light in weight.
• the material will not conform to many three-dimensional surfaces and resort must then be had to applying it in a patchwork manner which is unsightly, time-consuming, and a great deal more difficult because of the need for good tailoring of the patches and because of the difficulty of joining the patches one with another.
• Another recent proposal is an anti-fouling material consisting of a polyester resin with a high percentage of copper or other metallic particles mixed with it.
• the material marketed by Scott Bader Co. under the trade name Coppergel, is designed to form the outer layer of the underwater part of a boat which is to be built by successive laminations in a female mould. Accordingly, the underwater surface of the boat is as smooth as is permitted by the mould and the skill of the applicator. This seems an excellent solution to the problem of anti-fouling structures built in female moulds. However the material is difficult, if not impossible, to apply evenly and smoothly to an already-formed structure.
• the invention consists in an anti-fouling coating on a surface of a vessel or marine structure, characterised by alternate layers of paint and particulate metallic material applied to the surface, commencing with a layer of paint, the or each layer of particulate metallic material being adhered to the surface by the paint, and the outer surface of the coating being treated to expose sufficient metallic material to produce an anti-fouling characteristic.
• the invention consists in a method of applying an anti-fouling coating to a surface of a vessel or marine structure, characterised by the steps of alternately applying layers of paint and one or more layers of particulate metallic material to the surface, said application commencing and finishing with a layer of paint, and the or each layer of particulate metallic material being applied to a preceding paint layer whilst the latter is sufficiently wet or tacky to adhere the particulate material to the surface, and treating the final or outer paint layer, when hard, to expose sufficient metal to produce an anti-fouling characteristic.
• the invention provides a thin conformable coating which may be readily applied to surfaces subject to bio-fouling.
• the paint and particulate metallic material may be separately and easily applied by spraying techniques.
• the particulate metal can be sieved or thrown onto the wet or tacky paint, but has been found not to adhere so well as if sprayed.
• the paint can be brushed on instead of being sprayed, and this is entirely adequate, although there is a greater requirement to ensure that preceding layers are completely dry before brush application.
• the resulting anti-fouling coating can be as light as a single application of paint and particulate metal or can be as heavy as desired dependent on the number of paint and multiple powder layers, the size of the metallic powder particles, the consistency of the paint, and the mode of application.
• the particulate metallic material is preferably in finely divided or powder form and may, for example, have a particle size in the range from 100 to 300 British standard mesh and, preferably, 180 to 220 mesh.
• coarser powder also works well and, fundamentally, the particle size utilised depends on the thickness of a paint layer which can be satisfactorily applied. In this regard, the particle size should be such that the particles are almost entirely embedded in the preceding wet paint layer.
• the particulate metallic material comprises copper or a copper-nickel alloy.
• the latter may have a nickel content in the range from 5% to 35% by weight.
• the paint may be any suitable marine paint, such as a synthetic resin based marine paint.
• An advantage of the invention, which is based on the use of paint, is that a paint can be obtained suitable for coating practically any known surface. It is therefore easy to build up protection for structures to any known presently acceptable standard by the use of paint layers alone, before applying an anti-fouling coating according to the invention and including further paint layers to accept the particulate metallic material.
• an electrically insulating layer may be formed between the particulate metallic material and any metallic structure, which insulating layer inhibits the galvanic corrosion which would occur if dissimilar metals in the galvanic scale are used.
• copper or a copper- nickel alloy powder is sprayed onto a surface painted with a layer of two-pot polyurethane paint (that is a polyurethane based paint with a separate curing component), as marketed by International Paint Co.. It is sprayed onto the surface whilst the paint is still wet or tacky.
• the powder may be copper having a particle size such as mainly to pass through a 100 British standard mesh sieve whilst mainly not passing through a 300 British standard mesh sieve.
• it may be a copper-10% nickel alloy powder of similar size or a copper-25% nickel powder with 5% tin added.
• the powder forms a well defined layer on the paint taking on an appearance something like emery paper.
• a further layer of paint is applied, when the first paint layer has dried adequately, and this fills most of the spaces between the metal powder particles and serves further to bond the powder into a strong coating.
• this final paint layer has hardened, the surface of the resulting coating is lightly abraded with an abrasive paper, for example, with 600 mesh wet or dry emery paper, and this exposes sufficient metal to produce an anti-bio-fouling effect whilst, at the same time, providing a smooth and relatively friction free surface.
• the steps may be repeated so that alternate layers of paint and powder are built-up on the structure to be protected.
• an anti-fouling coating having multiple metal powder layers, it is generally unnecessary to abrade the layers of powder or paint except for the final or outer layer.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Life Sciences & Earth Sciences (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Combustion & Propulsion (AREA)
• Mechanical Engineering (AREA)
• Ocean & Marine Engineering (AREA)
• Paints Or Removers (AREA)
• Application Of Or Painting With Fluid Materials (AREA)

Applications Claiming Priority (2)

Publications (1)

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Family Applications (1)

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• 1983
  • 1983-04-27 WO PCT/GB1983/000124 patent/WO1983003804A1/en not_active Application Discontinuation
  • 1983-04-27 EP EP83902275A patent/EP0106897A1/de not_active Withdrawn
  • 1983-04-27 AU AU15124/83A patent/AU1512483A/en not_active Abandoned
  • 1983-04-27 JP JP58501468A patent/JPS59500662A/ja active Pending
  • 1983-12-27 FI FI834810A patent/FI834810A/fi not_active Application Discontinuation
  • 1983-12-27 NO NO834813A patent/NO834813L/no unknown

Non-Patent Citations (1)

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