WO2007104122A1 - procédé de protection des oléoducs contre la corrosion - Google Patents

procédé de protection des oléoducs contre la corrosion Download PDF

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Publication number
WO2007104122A1
WO2007104122A1 PCT/CA2006/000375 CA2006000375W WO2007104122A1 WO 2007104122 A1 WO2007104122 A1 WO 2007104122A1 CA 2006000375 W CA2006000375 W CA 2006000375W WO 2007104122 A1 WO2007104122 A1 WO 2007104122A1
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Prior art keywords
weight percent
radical
composition
carbon atoms
alkyl
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PCT/CA2006/000375
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English (en)
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WO2007104122A8 (fr
Inventor
Farooq Ahmed
Faisal Huda
Seraj Ul Huda
John Barr
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Csl Silicones Inc.
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Priority to CA002679976A priority Critical patent/CA2679976A1/fr
Priority to PCT/CA2006/000375 priority patent/WO2007104122A1/fr
Publication of WO2007104122A1 publication Critical patent/WO2007104122A1/fr
Publication of WO2007104122A8 publication Critical patent/WO2007104122A8/fr

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L58/00—Protection of pipes or pipe fittings against corrosion or incrustation
    • F16L58/02—Protection of pipes or pipe fittings against corrosion or incrustation by means of internal or external coatings
    • F16L58/04—Coatings characterised by the materials used
    • F16L58/10—Coatings characterised by the materials used by rubber or plastics
    • F16L58/1054—Coatings characterised by the materials used by rubber or plastics the coating being placed outside the pipe
    • F16L58/1072—Coatings characterised by the materials used by rubber or plastics the coating being placed outside the pipe the coating being a sprayed layer
    • 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
    • C09D183/00—Coating compositions based on macromolecular compounds obtained by reactions forming in the main chain of the macromolecule a linkage containing silicon, with or without sulfur, nitrogen, oxygen, or carbon only; Coating compositions based on derivatives of such polymers
    • C09D183/04—Polysiloxanes
    • 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
    • C09D5/08—Anti-corrosive paints
    • 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
    • C09D5/1656—Antifouling paints; Underwater paints characterised by the film-forming substance
    • C09D5/1662—Synthetic film-forming substance
    • C09D5/1675—Polyorganosiloxane-containing compositions
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16L—PIPES; JOINTS OR FITTINGS FOR PIPES; SUPPORTS FOR PIPES, CABLES OR PROTECTIVE TUBING; MEANS FOR THERMAL INSULATION IN GENERAL
    • F16L58/00—Protection of pipes or pipe fittings against corrosion or incrustation
    • F16L58/02—Protection of pipes or pipe fittings against corrosion or incrustation by means of internal or external coatings
    • F16L58/04—Coatings characterised by the materials used
    • F16L58/10—Coatings characterised by the materials used by rubber or plastics
    • F16L58/1054—Coatings characterised by the materials used by rubber or plastics the coating being placed outside the pipe
    • F16L58/1063—Coatings characterised by the materials used by rubber or plastics the coating being placed outside the pipe the coating being a sheet wrapped around the pipe

Definitions

  • TITLE METHOD FOR PROTECTING PIPELINES AGAINST CORROSION
  • This invention relates to a method of protecting surfaces, particularly pipelines from corrosion and in particular to a method which uses geo-tech or similar fabric and a vulcanizable polyorganosiloxane rubber composition to form a coating on the surface for the corrosion protection of the surface.
  • a common coating is one which is used to protect metal surfaces against corrosion.
  • Corrosion is an electrochemical process that causes degradation of metal by an oxidative process.
  • Environmental factors such as water, oxygen, salt and acid rain cause oxidative chemical reactions that slowly convert the metal into metal oxide and wear it off from the surface .
  • Coatings provide a barrier between the metal and the environmental factors that cause corrosion.
  • the efficiency of the coating and its service life depends on its barrier properties against penetration of moisture and other chemicals and its resistance to degradation caused by environmental factors such as salt, acid rain and Ultra Violet (UV) radiation.
  • the coating integrity may also be affected by mechanical damage which exposes the metal to the environment and initiates electrochemical oxidation of the metal and subsequent delamination of the coating.
  • Sacrificial metals such as zinc, nickel and aluminum in the coating provide relief against cathodic stress caused by contact of moisture, salt and oxygen to the exposed metal .
  • metal surfaces of pipelines exposed to moisture such as rain or fog in combination with contaminated atmospheres as are found in industrial locations may be subject to extensive corrosion unless protected in some way from exposure to the corrosive atmosphere.
  • Other potentially corrosive environments include along sea coasts where salt spray is found and in areas where agricultural chemicals are widely distributed.
  • metal pipelines directly exposed to water such as in marine or below grade installations are also subject to the potential for extensive corrosion. In the past, such metal surfaces have been most commonly protected by being painted with alkyd based paints.
  • Such paints form a relatively rigid coating on the surface of the metal which can become brittle and when subjected to stress, can flake or chip off, thereby exposing the underlying metal to the corrosive elements.
  • such paints generally are susceptible to UV damage thereby further reducing their effective life.
  • Two-part polyorganosiloxane rubber compositions for use as a corrosion protection coating on metals have been developed.
  • Lampe describes in U.S. Patent No. 4,341,842 a two-part room temperature vulcanizable composition for coating the underside of vehicles to protect the metal from rusting or being corroded by road salts or other similar compounds.
  • such two-part compositions have a major disadvantage in that they require the use of complex dual mixing and spray nozzle apparatus or require pre-mixing and immediate use on site when used with conventional spray equipment. If conventional spray equipment is used, the amount of material pre-mixed must also be exact to prevent wastage as the composition has a finite pot life.
  • the present invention provides for the protection of pipelines and other metal surfaces from corrosion.
  • the metal surface is coated with a vulcanizable elastomeric polyorganosiloxane coating re-inforced with geo-tech fabric or any other similar nature fabric or sheeting materials.
  • the geo-tech reinforced silicone provides both cathodic and corrosion protection in submersible underground and overground pipelines.
  • the vulcanizable polyorganosiloxane composition comprises: a) from about 5 to about 80 weight percent of one or more polyorganosiloxane fluids of the formula:
  • R is a monovalent alkyl or alkenyl radical having 1 to 8 carbon atoms or a phenyl radical
  • R 1 each of which may be the same or different are OH, a monovalent alkyl or alkenyl radical having 1 to 8 carbon atoms or a phenyl radical
  • n has an average value such that the viscosity is from about 10 to about 100,000 centipoise at 25 °C preferably from about 500 to about 20,000 centipoise at 25 °C.
  • the R 1 is a reactive group such as OH or alkenyl, preferably OH, most preferably both R 1 are OH.
  • the geo-tech or other fabric is impregnated and coated with a room temperature vulcanizable (RTV) polyorganosiloxane composition
  • RTV room temperature vulcanizable
  • R 14 is an alkyl or alkenyl radical having 1 to 8 carbon atoms or a phenyl radical which may contain 3 to 9 halogen atoms, and has an average value such that the viscosity is in the range from 10 to 100,000 centipoise at 25 0 C, preferably from 500 to 20,000 centipoise at 25 0 C;
  • the present invention also provides for a method of protecting exposed surfaces particularly metal surfaces more particularly, metal pipelines from the effects of a corrosive environment.
  • the method comprises applying to the surface a thin layer of a vulcanizable elastomeric polyorganosiloxane rubber composition, applying geo-tech or similar fabric onto the wet surface; optionally applying a second application of the same or a different vulcanizable elastomeric polyorganosiloxane rubber composition and allowing the composition to cure to a silicone elastomer.
  • the present invention provides for a method for coating surfaces, particularly metal and concrete surfaces, more particularly metal pipelines to protect them against corrosion.
  • the method comprises applying a vulcanizable elastomeric polyorganosiloxane coating reinforced with geo-tech fabric or any other similar fabric or sheeting materials to the surface to be protected.
  • the reinforced silicone provides cathodic and corrosion protection, particularly in submersible, underground, and overground pipelines.
  • the composition utilized in the present invention comprises a vulcanizable polyorganosiloxane along with suitable additives, depending upon the nature of the surface to be protected and the environment to which it is exposed.
  • the composition preferably includes a sacrificial metal filler which provides the composition with corrosion protection particularly against cathodic stress.
  • composition utilized in the present invention preferably comprises a vulcanizable polyorganosiloxane and a sacrificial metal filler which provides the composition with its corrosion protection particularly against cathodic stress.
  • the vulcanizable polyorganosiloxane may be any of the commonly utilized vulcanizing polyorganosiloxane compositions utilizing one part or two part systems cured catalytically, for example through addition curing, heat curing or utilizing moisture curing systems.
  • the polyorganosiloxane is terminated with a reactive group, generally hydroxyl or alkenyl as follows:
  • R is a monovalent alkyl or alkenyl radical having 1 to 8 carbon atoms or a phenyl radical which may contain 3 to 9 halogen atoms
  • R 1 each of which may be the same or different is a reactive group selected from OH, or a monovalent alkenyl radical having 1 to 8 carbon atoms
  • n has an average value such that the viscosity is from about 10 to about 100,000 centipoise at 25 °C preferably from about 500 to about 20,000 centipoise at 25°C.
  • Catalytically polymerizable polyorganosiloxane compositions using addition cure systems are not controlled by moisture of the atmosphere. High temperature can accelerate the curing process although the crosslinking addition reaction may also occur at room temperature.
  • the base polymer is generally a polydiorganosiloxane of general formula:
  • R 2 is a monovalent alkyl or alkenyl radical having 1 to 8 carbon atoms, optionally substituted with 1 to 9 halogen atoms, or a phenyl radical, optionally substituted with 1 to 6 halogen atoms
  • R 3 is monovalent alkenyl radical (preferably a monovalent vinyl or ethylene radical) and n has an average value such that the viscosity is from 10 to 100,000 centipoise.
  • An example of such a base polymer is :
  • the addition cure systems utilize a crosslinker to polymerize the base polymer.
  • the crosslinker is generally a polydiorganosiloxane of general formula:
  • each R 4 and R 5 which may be the same or different is a monovalent alkyl or alkenyl radical having 1 to 8 carbon atoms, optionally substituted with 1 to 9 halogen atoms, or phenyl radical, optionally substituted with 1 to 6 halogen atoms and H is hydride radical
  • m and n are integers and their total average value is such that the viscosity is from 10 to 10,000 centipoise.
  • the value of m is 10 to 50 percent of the value of m+n.
  • the ratio of the alkenyl radical, preferably ethylene radical, to hydride radical is from 1:1 to 6:1.
  • R 6 is alkyl or alkenyl and R 7 is alkenyl.
  • An example of such a platinum catalyst is:
  • Crosslinking by addition is an extremely fast reaction.
  • the reaction speed can be controlled by reducing the amount of catalyst or by using a reaction inhibitor such as a vinyl terminated dimethylsiloxane that reduces the activity of the platinum catalyst.
  • adhesion promoter may also be used for two-part addition cure system to improve the adhesion of the elastomer to the surface.
  • the adhesion promoter is generally a silane having general formula:
  • Addition cure systems are generally provided in two-parts with the base polymer, crosslinker, adhesion promoter and inhibitor in one part and base polymer and catalyst in the other part. Fillers and pigment are added in either part to achieve equivalent viscosity of both parts for homogenous mixing.
  • C.rosslinking of polyorganosiloxane terminated by alkenyl radical such as vinyl radical can also be accelerated by heat in presence of organic peroxide such as dichlorobenzoyl peroxide, trichlorobenzoyl peroxide or dicumyl peroxide as catalyst.
  • organic peroxide such as dichlorobenzoyl peroxide, trichlorobenzoyl peroxide or dicumyl peroxide as catalyst.
  • Crosslinking by organic peroxide does not require hydride functional crosslinker (as described in addition cure system) .
  • Moisture curing systems are generally room temperature vulcanizable (RTV) , although higher temperatures may be employed to accelerate the curing reaction.
  • the moisture curing composition may be provided as a two part system similar to the addition cure compositions or may be a one part composition containing all of the components of the composition in a single container. Preferably for ease of handling and application, the RTV compositions are in one part.
  • Moisture cure systems generally utilize a hydroxyl terminated polyorganosiloxane as a base polymer.
  • the base polymer is one or more polyorganosiloxanes of the general formula:
  • R 10 is a monovalent alkyl or alkenyl radical having 1 to 8 carbon atoms or a phenyl radical, which may
  • R 11 each of which may be the same or different are OH, a monovalent alkyl or alkenyl radical having 1 to 8 carbon atoms or a phenyl radical, and n has an average value such that the viscosity is from about 10 to about 100,000 centipoise at 25 °C preferably from about 500 to about 20,000 centipoise at 25 0 C.
  • At least one of the R 11 has a reactive group such as OH or alkenyl, preferably OH, most preferably both R 11 are OH.
  • the moisture curing systems utilize a crosslinker having the general formula:
  • R 12 is an alkyl, alkenyl or phenyl radical (preferably methyl or ethyl) and X an alkyl radical with a functional group linked directly to silicone atom and m is an integer of from 0 to 2.
  • the functional group can be carboxyl, ketoximino, alkoxy, carbonyl or amine.
  • cross linkers for moisture cure RTV One-Part or Two-Part Systems include:
  • Acetoxy Silane (CH 3 C(O)O) 3 -Si-R 12 Releases Acetic Acid as curing by-product.
  • Oxime Silane (C 2 H 5 (CH 3 )C NO) 3 -Si-R 12 Releases methylethyl ketoxime as curing by-product.
  • a catalyst is generally utilized.
  • an organotin salt such as dibutyl tin dilaurate, among others.
  • an adhesion promoter may be employed.
  • the adhesion promotor is commonly a compound of the formula:
  • R 15 and R 16 are independently selected from monovalent alkyl or alkenyl radicals having 1 to 8 carbon atoms or a phenyl radical which may optionally be substituted with an alkyl radical having 1 to 8 carbon
  • R is a saturated, unsaturated or aromatic hydrocarbon radical having 1 to 10 carbon atoms which may optionally contain a functional group.
  • the one-part polyorganosiloxane rubber compositions of the present invention for use as a protective coating contain about 5 to about 80 weight percent of one or more polydiorganosiloxane fluids of the formula:
  • n has an average value such that the viscosity is from about 10 to about 100,000 centipoise at 25 0 C.
  • n has an average value such that the viscosity is between about 500 and about 20,000 centipoise at 25 0 C, more preferably between about 1,000 and about 20,000 centipoise at 25 0 C.
  • Polydimethylsiloxane is the most preferred silicone polymer fluid.
  • the polydimethylsiloxanes may contain small amounts of monomethylsiloxane units and methyl radical replaced with other radicals in small amounts as impurities such as is found in commercial products, but the preferred fluid contains only polydimethylsiloxane.
  • low viscosity fluids generally 1,000 centipoise or less, it may be advantageous to add bifunctional chain extenders of the general formula:
  • X 1 is an alkyl radical with a functional group linked directly to the silicon atom, preferably alkoxyl, ketoximino, carbonyl, carboxyl or amine, most preferably alkoxy or ketoximino and R 18 is a monovalent alkyl or alkenyl radical having 1 to 8 carbon atoms or a phenyl radical. If chain extenders are utilized they are generally present in an amount of up to about 8 weight percent, preferably between about 2 weight percent and about 8 weight percent.
  • the composition of this preferred embodiment may contain a second linear dimethyl polysiloxane of low molecular weight to act as a viscosity reducer diluent for the composition for ease in applying the composition to the surface.
  • the low molecular weight linear dimethyl polysiloxanes are end blocked oligomeric compounds of the above formula where the terminal -OH are replaced by blocking groups which may be the same or different, are independently selected from a monovalent alkyl or alkenyl radical having 1 to 8 carbon atoms or phenyl radical.
  • the average value of n ranges between 4 and 24, preferably between 4 and 20.
  • the total of the polyorganosiloxanes is generally about 40 to 60 weight percent with the relative amounts of the two polyorganosiloxanes being selected based upon the desired characteristics of the final coating.
  • each of the polyorganosiloxanes will be present in a ratio of from about 30 weight percent to about 70 weight percent based upon the total weight of the polyorganosiloxane fluids .
  • the composition may contain up to about 40 weight percent, more preferably 20 to 30 weight percent of a cyclo-organosiloxane of the formula:
  • R 19 is a monovalent alkyl or alkenyl radical having 1 to 8 carbon atoms or a phenyl radical which may optionally be substituted with an alkyl radical having 1 to 8 carbon atoms and n has an average value of 3 to 10.
  • the preferred cycloorganosiloxane is a cyclic dimethylsiloxane and is used in a similar manner to the low molecular weight linear dimethyl polysiloxanes as a diluent to lower the viscosity of the composition for convenient application by spraying, brushing or dipping.
  • the composition may contain up to 80 weight percent of one or more fillers.
  • the fillers may be functional fillers to increase the resistance of the coating to environmental effects, sacrificial metal fillers to increase the resistance of the coating to cathodic stress from environmental effects, conducting fillers, extending or non-reinforcing fillers and reinforcing fillers to provide for increased strength of the coating.
  • the composition preferably contains 10 to 80 weight percent, more preferably 30 to 60 weight percent, most preferably 40 to 50 weight percent, of sacrificial metal fillers to increase the resistance of the coating to cathodic stress from environmental effects.
  • the sacrificial metal fillers are preferably selected from zinc powder, zinc flakes, aluminum powder, aluminum flakes, nickel powder, nickel flakes, magnesium powder, and magnesium flakes.
  • the conductive fillers are preferably selected from metal coated glass fibres or powder and mica.
  • the formulation may include other inorganic extending or non-reinforcing fillers depending upon the nature of the surface and environment wherein the coating is to be used.
  • the extending fillers are preferably selected from inorganic materials such as calcium carbonate, barium sulfate, iron oxide, diatomaceous earth, quartz, crystalline silica, titanium dioxide, zinc oxide, zirconium oxide, zirconium silicate, zinc borate and chromic oxide.
  • inorganic materials such as calcium carbonate, barium sulfate, iron oxide, diatomaceous earth, quartz, crystalline silica, titanium dioxide, zinc oxide, zirconium oxide, zirconium silicate, zinc borate and chromic oxide.
  • the selection of the filler will be based upon the required properties and the final usage of the composition. For applications where high temperature stability is required a preferred additional filler will be melamine, iron oxide, zinc oxide, titanium dioxide, zirconium oxide, zinc borate or chromic oxide. For coatings requiring higher strength crystalline silica is utilized.
  • the composition may also contain about 0 to 20 weight percent of an amorphous SiO 2 reinforcing filler having a surface area of between about 50 and about 250 m 2 /g and a particle size range between about 0.01 and 0.03 microns.
  • the surface area is between about 50 and about 150 m 2 /g, more preferably between about 75 and about 150 m 2 /g.
  • the specific gravity of the filler is preferably about 2.2.
  • the surface of the amorphous silica may also be treated with organic molecules such as hexamethyldisilazane or polydimethylsiloxane or silane. It has been found that using a surface treated silica helps reduce the viscosity of the composition. Similarly the use of lower surface area fillers also aids in reducing viscosity of the composition.
  • composition also contains about 0.1 to about 35 weight percent, preferably about 3 to about 15 weight percent, more preferably about 3 to about 10 weight percent of an organofunctional cross-linking agent of general formula:
  • R 12 is an alkyl, alkenyl or phenyl radical (preferably methyl or ethyl)
  • X is an alkyl radical with a functional group selected from carboxyl, ketoximino, alkoxy, carbonyl or amine linked directly to the silicone atom
  • m is an integer of from 0 to 2.
  • the preferred R 20 and R 21 are alkyl or vinyl radicals, most preferably methyl and ethyl radicals .
  • the composition also contains about 0.2 to about 3 weight percent of an organo functional silane as an adhesion promoter.
  • an organo functional silane has the formula:
  • R and R are independently selected from monovalent alkyl or alkenyl radicals being 1 to 8 carbon atoms or a phenyl radical which optionally may be substituted with alkyl radicals having 1 to 8 carbon atoms and contain 3 to 9 halogen atoms
  • b is an integer from 0 to 3, preferably 0, and
  • R 24 is a saturated, unsaturated or aromatic hydrocarbon radical being 1 to 10 carbon atoms, which may be further functionalized by a member selected from the group consisting of amino, ether, epoxy, isocyanate, cyano, acryloxy and acyloxy and
  • R and R are preferably an alkyl radical such as, for example, methyl, ethyl, propyl, butyl, or an alkenyl radical such as vinyl and allyl.
  • R and R are alkyl radicals, most preferably methyl, ethyl or propyl radicals.
  • R 24 is an alkyl group, more preferably further functionalized by one or more amino groups.
  • the most preferred organo-functional silane is N- (2-aminoethyl-3- aminopropyl) trimethoxysilane .
  • the composition additionally contains from about 0 to about 5 weight percent of an organometalic complex as a condensation catalyst which accelerates the aging of the composition.
  • the condensation catalyst is of the formula:
  • R 25 is monovalent alkyl or alkenyl radical having 1 to 10 carbon atoms or a phenyl radical
  • R 26 is an alkyl or alkenyl radical having 1 to 10 carbon or a phenyl radical having an organo-functional group
  • M is a metal.
  • the organometalic complex is an organotin complex of a carboxylic acid selected from the group consisting of dibutyltindiacetate, stannous octoate, dibutyltin dioctoate and dibutyltin dilaurate.
  • the condensation catalyst is present from about 0.02 to about 3 weight percent.
  • the organotin salt is dibutyltin dilaurate of the formula:
  • the alkyl includes straight, branched or cyclic radicals.
  • the alkyl groups are C 1-10 straight or branched-chain alkyl such as, for example, methyl, ethyl, propyl, isopropyl, n-butyl, isobutyl, tert-butyl, pentyl, isopentyl, hexyl, etc.
  • the cycloalkyl are C 3 _ 8 cycloalkyl such as, for example, cyclopropyl, cyclobutyl, cyclohexyl, etc.
  • the alkenyl groups are C 1-10 alkenyl such as, for example, vinyl and allyl.
  • the above groups as well as the phenyl radicals may be further functionalized by including in the chain or ring structure, as the case may be, a group selected from the class consisting of amino, ether, epoxy, isocyanate, cyano, acryloxy, acyloxy and combinations, so long as the functionalization does not adversely affect the desired properties of the compound.
  • the composition may contain up to about 40, perferably about 10 to 40 weight percent of a suitable solvent or diluent as a dispersion medium.
  • the solvent or diluent is a hydrocarbon solvent used as a dispersion medium for the composition.
  • the hydrocarbon solvent if present, is preferably a petroleum based solvent such as naphtha or mineral spirits.
  • the composition may contain other optional ingredients such as pigments and other fillers in minor amounts provided that the addition of the ingredients does not cause degradation of the corrosion resistance of the cured coating made from the composition.
  • One commonly utilized optional ingredient is a pigment, preferably a grey pigment, most preferably present in amounts up to about 1 weight percent.
  • the polyorganosiloxane composition of the present invention are prepared by mixing the ingredients together in a conventional manner.
  • the moisture cure polyorganosiloxane composition of the present invention is prepared by mixing the ingredients together in the absence of moisture.
  • the silane is moisture sensitive and will undergo cross-linking in the presence of moisture such that the mixture must be essentially absent of free moisture when the silane is added and maintained in a moisture free state until cure is desired.
  • a preferred method of mixing comprises mixing the polyorganosiloxane polymer with the reinforcing fillers and other optional fillers and pigments. Thereafter, the oximinosilane and organo functional silane are added and mixed under a nitrogen atmosphere. The solvent is added to the mixture under a nitrogen atmosphere and finally, the organotin salt is added to the mixture. The mixture is then dispensed in the sealed containers for storage prior to use.
  • the surface of the metal to be protected is coated with the composition by conventional methods such as dipping, brushing or spraying. Preferably, the metal to be protected is coated by spraying an application of the composition of the present invention.
  • the coating generally has an average thickness of 0.25 to 1.50 mm, single or more preferably, an average thickness of 0.5 to 1.0 mm, most preferably about 0.5 to 0.75 mm.
  • the metal is wrapped spirally or circumferentially with a pre-cut sheet of geo-tech or similar fabric and then exposed to normal atmosphere for cross-linking and cure of the coating. Thereafter a second coating of the same or different composition may be applied and allowed to cure.
  • the improved coating of the present invention is capable of protecting metal pipelines from corrosion in the presence of moisture such as rain or fog in combination with contaminated atmospheres, salt spray or fog or direct exposure to salt water.
  • the improved coating method of the present invention is particularly useful for protecting metal pipelines which are directly exposed to water or are buried underground.
  • a coating composition was prepared by mixing 24 parts by weight of polydimethylsiloxane fluid having viscosity of 5,000 centipoise and 2 parts by weight of surface treated amorphous silica having surface treatment with hexamethyldisilazane and surface area of about 125 m 2 /g, 10 parts by weight of metal coated glass fibres. Then 3 parts by weight of methyl tris- (methyl ethyl ketoxime) silane and 1 part by weight of N- (2-aminoethyl-3- aminopropyl) trimethoxy silane are added and mixed under nitrogen atmosphere. Then 50 parts by weight of zinc powder were also added and mixed.
  • the coating composition was diluted 10 parts by weight of petroleum naphtha to achieve a viscosity between 3,000 and 4,000 cP.
  • Cured elastomeric coating provides excellent resistance against chemicals, galvanic corrosion, cathodic stress and cathodic delamination.
  • a second coating composition was prepared by mixing 36 parts of dimethyl polysiloxane fluid having a viscosity of 16,750 centipoise at 25°C with 35 parts of a mixture of amorphous and crystalline silica fillers having a specific gravity of 2.2 and surface area of about 130m 2 /g. Then 2 parts of pigment is added and the composition is mixed in a mixer to a uniform consistency. Then 3 parts of methyl tris- (methyl ethyl ketoxime) silane and 1 part of N- (2-aminoethyl-3 aminopropyl) trimethoxysilane are added and mixed under a nitrogen atmosphere. Then 23 parts of naphtha solvent is added to the mixture. Finally, 0.1 part of dibutyltin dilaurate is added to the dispersion and mixed until a uniform consistency is achieved.
  • Example 1 or 2 preferably Example 1
  • WFT wet film thickness
  • a pre-cut sheet of geo-tech fabric is spirally or circumferentially wrapped firmly on the wet coating on the pipe.
  • the geo-tech fabric is preferably about 135 gr/m 2 specification and the width cut to suit pipe diameter for convenient spiral wrapping.
  • the geo- tech fabric-wrapped pipe was allowed to cure overnight.
  • Pipes were kept in a horizontal position.
  • the drying area was well ventilated with controlled temperature and humidity levels at 30° C and 50% RH.
  • a second layer of the composition of Example 1 or Example 2 was uniformly sprayed over the entire surface of the geo-tech fabric at an approximate rate of one (1) litre per square meter of the external surface area over the geo-tech fabric wrapping.
  • the coated pipe was placed horizontally on stands above ground so that the web coated surfaces are not disturbed and allowed to cure for 24 hours under similar conditions as in the first drying step.
  • the pipes were then ready for shipment. All the above procedures may be carried out either manually or for high output, using a mechanically automated system and robotic spraying mechanism.
  • the interior of the pipe may also be coated with the composition of Example 1 or Example 2 with or without reinforcing fabric material.
  • the concept is also applicable to concrete pipes underground/overground in saline or other corrosive and concrete spalling conditions .

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  • Wood Science & Technology (AREA)
  • Organic Chemistry (AREA)
  • Mechanical Engineering (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Paints Or Removers (AREA)
  • Application Of Or Painting With Fluid Materials (AREA)
  • Laminated Bodies (AREA)

Abstract

L'invention concerne la protection des oléoducs et autres surfaces métalliques contre la corrosion. La surface métalliques est enduite d'un revêtement polyorganosiloxane élastomère vulcanisable renforcé de tissu géo-tech ou tout autre tissu de nature similaire ou matériaux en feuilles de nature similaire. Dans un mode de réalisation préféré la silicone renforcée géo-tech assure à la fois une protection cathodique et une protection contre la corrosion pour les oléoducs terrestres et souterrains submersibles. La présente invention concerne également un procédé de protection de surfaces exposées, en particulier de surfaces métalliques, plus particulièrement d'oléoducs métalliques, contre les effets d'un environnement corrosif. Le procédé consiste à appliquer à la surface une mince couche d'une composition de caoutchouc polyorganosiloxane élastomère vulcanisable, à appliquer un tissu géo-tech ou similaire sur la surface humide ; à appliquer éventuellement une seconde couche de la même composition de caoutchouc polyorganosiloxane élastomère vulcanisable ou d'une composition différente et à laisser la composition durcir pour obtenir un élastomère de silicone.
PCT/CA2006/000375 2006-03-14 2006-03-14 procédé de protection des oléoducs contre la corrosion WO2007104122A1 (fr)

Priority Applications (2)

Application Number Priority Date Filing Date Title
CA002679976A CA2679976A1 (fr) 2006-03-14 2006-03-14 Procede de protection des oleoducs contre la corrosion
PCT/CA2006/000375 WO2007104122A1 (fr) 2006-03-14 2006-03-14 procédé de protection des oléoducs contre la corrosion

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/CA2006/000375 WO2007104122A1 (fr) 2006-03-14 2006-03-14 procédé de protection des oléoducs contre la corrosion

Publications (2)

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WO2007104122A1 true WO2007104122A1 (fr) 2007-09-20
WO2007104122A8 WO2007104122A8 (fr) 2008-10-09

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PCT/CA2006/000375 WO2007104122A1 (fr) 2006-03-14 2006-03-14 procédé de protection des oléoducs contre la corrosion

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Country Link
CA (1) CA2679976A1 (fr)
WO (1) WO2007104122A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2013070156A1 (fr) * 2011-11-07 2013-05-16 Hwq Relining Systems Aktiebolag Revêtement d'une conduite ou d'un système de conduites avec un matériau polymère
EP2229241B1 (fr) * 2007-12-04 2019-06-05 Oerlikon Metco (US) Inc. Revêtement anticorrosif multicouche

Citations (6)

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HU174391B (hu) * 1977-03-30 1979-12-28 Taurus Gumiipari Vallalat Sposob poluchenija protivokorrozijjnojj sistemy
JPH01174442A (ja) * 1987-12-28 1989-07-11 Toray Silicone Co Ltd シリコーンゴム被覆布積層体の製造方法
US4868063A (en) * 1986-07-22 1989-09-19 Shin-Etsu Chemical Co., Ltd. Glass fiber article-coating compositions
JPH05140458A (ja) * 1991-11-20 1993-06-08 Toray Dow Corning Silicone Co Ltd 湿気硬化型シリコーン粘着剤組成物
CA2241766A1 (fr) * 1998-06-25 1999-12-25 Csl Silicones Inc. Composition simple de caoutchouc de silicone pour utiliser comme revetement protecteur contre la corrosion sur les metaux
CA2280519A1 (fr) * 1999-08-20 2001-02-20 Csl Silicones Inc. Composition simple de caoutchouc en silicone pour utilisation comme revetement de protection contre la corrosion

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HU174391B (hu) * 1977-03-30 1979-12-28 Taurus Gumiipari Vallalat Sposob poluchenija protivokorrozijjnojj sistemy
US4868063A (en) * 1986-07-22 1989-09-19 Shin-Etsu Chemical Co., Ltd. Glass fiber article-coating compositions
JPH01174442A (ja) * 1987-12-28 1989-07-11 Toray Silicone Co Ltd シリコーンゴム被覆布積層体の製造方法
JPH05140458A (ja) * 1991-11-20 1993-06-08 Toray Dow Corning Silicone Co Ltd 湿気硬化型シリコーン粘着剤組成物
CA2241766A1 (fr) * 1998-06-25 1999-12-25 Csl Silicones Inc. Composition simple de caoutchouc de silicone pour utiliser comme revetement protecteur contre la corrosion sur les metaux
CA2280519A1 (fr) * 1999-08-20 2001-02-20 Csl Silicones Inc. Composition simple de caoutchouc en silicone pour utilisation comme revetement de protection contre la corrosion

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Title
KHARITONOV N.P.: "Use of organosilicate material for the protection of austenitic steel pipelines against corrosion cracking", ANTIKORROZ. POKRYTYA, TR. VSES. SOVESHCH. ZHAROSTOIKIM POKRYTIYAM, 10TH, 1983, pages 257 - 261 *

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP2229241B1 (fr) * 2007-12-04 2019-06-05 Oerlikon Metco (US) Inc. Revêtement anticorrosif multicouche
WO2013070156A1 (fr) * 2011-11-07 2013-05-16 Hwq Relining Systems Aktiebolag Revêtement d'une conduite ou d'un système de conduites avec un matériau polymère
EP2776754A4 (fr) * 2011-11-07 2015-08-12 Hwq Relining System Ab Revêtement d'une conduite ou d'un système de conduites avec un matériau polymère

Also Published As

Publication number Publication date
WO2007104122A8 (fr) 2008-10-09
CA2679976A1 (fr) 2007-09-20

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