Classifications

• • 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
  • C09D7/00—Features of coating compositions, not provided for in group C09D5/00; Processes for incorporating ingredients in coating compositions
  • C09D7/40—Additives
  • C09D7/60—Additives non-macromolecular
  • C09D7/61—Additives non-macromolecular inorganic
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L83/00—Compositions of 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; Compositions of derivatives of such polymers
  • C08L83/04—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
  • 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
  • C09D5/18—Fireproof paints including high temperature resistant paints
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B3/00—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties
  • H01B3/18—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances
  • H01B3/30—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes
  • H01B3/46—Insulators or insulating bodies characterised by the insulating materials; Selection of materials for their insulating or dielectric properties mainly consisting of organic substances plastics; resins; waxes silicones
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B7/00—Insulated conductors or cables characterised by their form
  • H01B7/17—Protection against damage caused by external factors, e.g. sheaths or armouring
  • H01B7/29—Protection against damage caused by extremes of temperature or by flame
  • H01B7/295—Protection against damage caused by extremes of temperature or by flame using material resistant to flame
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/18—Oxygen-containing compounds, e.g. metal carbonyls
  • C08K3/24—Acids; Salts thereof
  • C08K3/26—Carbonates; Bicarbonates

Definitions

• This invention relates to a fire performance composition or material, a cable insulated with the material, and to a method of manufacturing a cable using the composition.
• the invention is particularly suited for use in fire resistant cables and other applications where composition is required to maintain physical and/or electrical characteristics during and after exposure to fire.
• Additives can include aluminium hydroxide, as discussed in US6043309 (Dow Corning) which is addressed to improvements in the extrusion properties and viscosity of silicone with aluminium hydroxide.
• GB2016307 discloses a mineral insulated electrical cable having a water repellent filling.
• Such cables consist of an electrical conductor contained in a hollow metal jacket, with a powdered filler material contained between the conductor and the jacket.
• the filler can include a silicone material.
• This document does not disclose a cable jacket material having a flexible jacket of silicone with a filler material blended into the silicone jacket material. The powdered filler cannot be applied by extrusion.
• EP0283132 discloses a mineral insulated electrical cable having a filling which included flame retardant and water repellent characteristics.
• the structure of these cables is an electrical conductor contained in a metal jacket, with the filler material in powdered form and compacted between the conductor and the jacket.
• the powder filler can include, among other materials, CaCO 3 in proportions of up to about 5%, and the water resistant material can be, among other materials, silicone in either a liquid or powder form.
• the CaCO 3 is included for the purpose of generating CO 2 .
• This document does not disclose a cable jacket material having a flexible jacket of silicone with a filler material blended into the jacket material. The low proportion of CaCO 3 would not permit the formation of a useful or significant post-combustion residue.
• EP0708455 discloses a flame resistant material including an organosilicon polymer with a ceramizable filler material.
• This specification describes a number of ceramizable fillers or glassformers, being a material that has the property of being able to form a glass, or an amorphous liquid with very high viscosity at room temperature but with low viscosity at high temperatures as seen in a fire.
• Additional auxiliary fillers such as CaCO 3 , among others, are also disclosed, for use in addition to the ceramizable filler. The purpose or function of these additional fillers is not disclosed.
• Ceramizable fillers are an essential component of EP0708455.
• the specification states that the organosilicon material needs to be compatible with the ceramizable filler.
• the specification discloses between 50 and 300 parts by weight of ceramizable filler per 100 parts by weight of polymer. An upper limit of 500 parts by weight of ceramizable and non-ceramizable filler is disclosed.
• the EP0708455 specification indicates that materials according to the invention all contain a ceramizable composition in the proportions set out above, the purpose being to produce a post-combustion ceramic layer on the wires. However, EP0708455 discloses only a material with amounts of ceramizable filler sufficient to form an insulative layer.
• EP0708455 does not disclose or suggest a material without any ceramizable filler or with amounts of ceramizable filler insufficient to form a useful insulation layer.
• the minimum amount of ceramizable filler disclosed is 50 parts by weight of ceramizable filler to 100 parts by weight of polymer.
• the invention is predicated, at least in part, on the inventor's insight that certain compounds of calcium, silicone, and oxygen have high electrical resistivity. In addition, at least some of such compounds may also have good mechanical properties such as strength, cohesiveness and adhesion to metal.
• a fire performance material including a polymer (1.006) including silicone polymer, and CaCO 3 filler (1.004), wherein the CaCO 3 filler is present in the material in an amount to leave a post- combustion residue after exposure of said material to fire, the material including less than 50 parts by weight of ceramizable filler to 100 parts by weight of polymer.
• the post-combustion residue can be an insulating residue or a protective residue.
• the material can advantageously include less than 20 parts by weight of ceramizable filler, preferably less than 10 parts by weight of ceramizable filler, preferably less than 5 parts by weight of ceramizable filler, and more preferably zero parts by weight of ceramizable filler.
• the ceramizable filler defined in the background of the invention, can be those described in EP0708455.
• not less than 92 weight % of the material can be made up Of CaCO 3 and polymer.
• the fire performance material including at least 20 parts by weight CaCO 3 filler to 100 parts by weight of polymer.
• the CaCO 3 filler can be up to 250 parts by weight to 100 parts by weight of polymer.
• the filler can be in the range of 30 parts by weight to 70 parts by weight filler to 100 parts by weight polymer.
• the silicone polymer of said fire performance material can be silicone elastomer.
• the polymer can consist exclusively of silicone elastomer.
• the fire performance material can further include a cross-linking agent.
• the invention also includes a cable having a fire resistant layer made from the fire performance material. Said layer can be an insulating layer or a protective layer (jacket).
• the insulating or protective layer can form a residue in the form of a post-combustion layer on a substrate.
• Said substrate can be one or several metal conductor, and/or one or several insulated conductor.
• the residue can include at least one compound including Ca and Si.
• the residue can include at least one of: Wollastonite (CaSiOs), Calcium
• Oxide (CaO), Larnite (Ca 2 (SiO 4 ), Calcite (CaCO 3 ), Calcium Silicate (Ca 2 SiO 4 ), Portlandite (Ca(OH) 2 ), SiO 2 (Hexagonal), and SiO 2 .
• the post-combustion residue can adhere to the conductor.
• the residue can be cohesive.
• the fire performance material can be applied as a jacket or sub-layer on an electrical conductor.
• the material can be used to provide a coating on cable conductors.
• the coating can be an external jacket or an internal layer.
• the invention also provides a method of manufacturing a cable according to claim 11 including the steps of: mixing CaCO 3 filler (1.004) with the polymer (1.006) to obtain a coating material; and extruding the coating material onto an electrical conductor (1.010) to form the fire resistant layer (1.014).
• the material of the present invention has the surprising advantage that a residue with good post-combustion electrical resistance characteristics is formed with little or no other fillers, and especially with little or no ceramifying material. At the same time, the material is cheaper than silicone polymer or silicone polymer and ceramifying filler.
• Figure 1 schematically illustrates the components of a cable coating system adapted to use the fire resistant material of the invention.
• Figure 2 is a graphical representation of X-Ray Diffraction analysis of the post-combustion residue according to an embodiment of the invention.
• Wollastonite As mentioned above, certain compounds of calcium, silicon, and oxygen, such as Wollastonite (CaSiOs), have good electrical resistivity. Wollastonite has a melting point in excess of 1500 0 C.
• the invention derives in part from the inventor's insight that such compounds may be formed during combustion by providing potential precursor material for calcium oxide and silica from silicone decomposition.
• the inventor deduced that a mixture of silicone and CaCO 3 in the presence of fire can produce the CaO and silica, which would then become available to form the target compounds during the fire.
• the inventor further reasoned that the mechanical properties of such combustion products could be sufficient to provide an insulative or protective residue which has adequate mechanical properties such that ceramic forming fillers were thus superfluous at least for some applications.
• one embodiment of the invention provides a fire resistant material including a mixture of silicone polymer and CaCO 3 , the CaCO 3 being present in the mixture in an amount to leave an insulating or protective layer on a substrate such as an electrical conductor.
• Products of the exposure of the mixture of silicone elastomer and CaCO 3 can include one or more of the following: Wollastonite (CaSiO 3 ), Calcium Oxide (CaO), Larnite (Ca 2 (SiO 4 ), Calcite (CaCO 3 ), Calcium Silicate (Ca 2 SiO 4 ), Portlandite (Ca(OH) 2 ), SiO 2 (Hexagonal), and SiO 2 (Rhombo. H. axes) in a mix of crystalline and amorphous forms.
• the resulting post-combustion residue provides surprisingly good electrical properties at temperatures of the order of 1000 0 C.
• Figure 1 schematically illustrates the components of a cable coating system adapted to use the fire resistant material of the invention.
• the system includes a supply OfCaCO 3 1.004, a supply of silicone elastomer 1.006, a mixer 1.008, and an extruder head 1.012.
• the CaCO 3 and silicone elastomer are mixed in the mixer 1.008 in a predetermined ratio to provide an extrudable composition and fed to the extruder 1.012.
• a single electrical conductor, or a bundle of electrical conductors, 1.010 is drawn through the extruder head and coated with the mixture.
• the mixture is such as to form an electrical insulating layer 1.014 on the conductor, the insulating layer having adequate mechanical properties to permit the handling, installation and use of the cable, and such that, after exposure to fire, the combustion products of the mixture will form an electrically resistive or insulative residue layer to maintain electrical functionality of the cable.
• An additional external jacket can be extruded over the layer of fire resistant material to provide additional strength or insulation if required.
• composition was prepared by adding CaCO 3 (Omyacarb 2T) (50/50 wt% basis) to Wacker R401/80S silicone elastomer with 2% Perkadox 14-40 peroxide.
• composition was extruded at 0.8 mm wall thickness onto 7/0.50 mm bunched plain annealed copper wire and air oven cured at 190°C/2hrs.
• the coated wire was twisted with another coated wire and subjected to a fast rising temperature in a tube furnace while measuring the resistance between the twisted wires.
• a powder sample of the residue was subjected to X-Ray Diffraction analysis to determine its phase composition.
• a Bruker D8 Advance X-ray Diffractometer with CuK 0 - radiation (4OkV, 4OmA) monochromatised with a graphite sample monochromator was employed to determine the X-ray diffraction (XRD) pattern.
• the sample was scanned over the 2-theta range 5° to 85° with a step size of 0.02° and a count time of 4 seconds per step. Analyses were performed on the collected XRD data for the sample using the Bruker XRD search match program EVATM.
• Figure 2 illustrates X-Ray Diffraction analysis results for the residue from mixture according to an embodiment of the invention. Peaks can be seen for Larnite, Wollastonite, CaO (Face Centred), and Calcite.
• An advantage of the present invention is that silicone can be heavily loaded with CaCO 3 .
• a range of 20% to 70% CaCO 3 and 80% to 30% silicone may be possible.
• Both the pre-combustion mixture and the post-combustion residue have good electrical insulative properties.
• the post combustion residue also has good adhesion to the conductor and good mechanical strength.
• the residue layer can also serve to protect the conductor from water.

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• Chemical & Material Sciences (AREA)
• Organic Chemistry (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Inorganic Chemistry (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Insulated Conductors (AREA)
• Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)

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• 2010
  • 2010-02-25 EP EP10719380A patent/EP2401329A1/de not_active Withdrawn
  • 2010-02-25 WO PCT/IB2010/000628 patent/WO2010097705A1/en active Application Filing
  • 2010-02-25 AU AU2010217302A patent/AU2010217302A1/en not_active Abandoned
  • 2010-02-25 CA CA2750512A patent/CA2750512A1/en not_active Abandoned

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