Classifications

• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
  • H01B13/00—Apparatus or processes specially adapted for manufacturing conductors or cables
  • H01B13/06—Insulating conductors or cables
  • H01B13/065—Insulating conductors with lacquers or enamels
• • 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
  • C09D183/10—Block or graft copolymers containing polysiloxane sequences
• • 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
  • H01B3/308—Wires with resins
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2927—Rod, strand, filament or fiber including structurally defined particulate matter
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T428/00—Stock material or miscellaneous articles
  • Y10T428/29—Coated or structually defined flake, particle, cell, strand, strand portion, rod, filament, macroscopic fiber or mass thereof
  • Y10T428/2913—Rod, strand, filament or fiber
  • Y10T428/2933—Coated or with bond, impregnation or core

Definitions

• the invention relates to filled hybrid varnishes, in particular for wires used in windings, and to winding wires covered in such varnish.
• Winding wires insulated by layers of varnish are used, for example, in the manufacture of coils for variable frequency controllers and converters.
• Standard winding wires comprise a wire of conductive material, generally copper, covered in one or more layers of varnish of the polyester imide (PEI) type and/or of the polyamide imide (PAI) type in the highest temperature class, and they can withstand 200° C. for 20,000 hours.
• PEI polyester imide
• PAI polyamide imide
• PI polymide
• varnishes have recently been described comprising both organic portions and mineral portions in a single phase. Such varnishes are also known as “hybrid” varnishes. Such varnishes based on precursors for ceramics are described by K. Asano, K. Suzuki, S. Itonaga, and Y. Tetsu in Hitachi Cable Review, No. 16 (March 1997), 67-74. Because of the brittleness and the hardness of ceramics, the precursor such as a silicone or a polycarboxysilane is transformed into a ceramic only after the coil has been wound. After being subjected to special heat treatment, those varnishes withstand temperatures of up to 400° C. However, it would appear that that technique has not led to any application on an industrial scale.
• Varnish for winding wires must also have considerable mechanical strength associated with adequate flexibility in order to ensure that the varnish does not crack, in particular while the wires are being wound into a coil.
• Varnishes are known for winding wires that include special formulations for withstanding Corona type discharges.
• Document U.S. Pat. No. 4,503,124 describes an example of a varnish composition comprising a polymer resin filled with alumina particles of a size smaller than 0.1 micrometers ( ⁇ m).
• those varnishes present an unsatisfactory temperature rating.
• Document U.S. Pat. No. 5,654,095 describes a protective coating that can withstand voltage peaks approaching 3000 V, rise times of less than 100 kV/ ⁇ s, and temperatures of up to 300° C.
• That protective coating comprises a resin and a filler in the form of particles of sub-micrometer size, such as particles of metal oxides, silica, and clays. Nevertheless, that protection necessarily requires a base insulation layer, thereby leading to a method that is complicated.
• the mechanical strength of those varnishes is poor, particularly when wires coated in varnish are subjected to mechanical deformation prior to winding. That type of wire can then lose its ability to withstand Corona aging. It has been found that its lifetime can be reduced by 90% if the wire is subjected to prior stretching of 10%.
• Document WO 98/25277 describes a hybrid varnish obtained by condensing silicon compounds, optionally together with other elements, in the presence of water. Adding fine particles of silanized glass as a filler is also mentioned. Those varnishes present poor ability to withstand partial electrical discharge at high frequency and they are unsatisfactory, even at low frequency, at temperatures in excess of 150° C.
• document EP-0 768 680 describes a hybrid varnish to which particles of SiO 2 of a size lying in the range 50 nanometers (nm) to 100 nm can be added in order to increase the mineral content of the varnish. No mention is made of any effect due to the presence of such particles and concerning ability to withstand partial discharges or voltage peaks.
• the invention proposes a composition comprising:
• a mineral filler selected from compounds of B, Al, Ti, Zn, Zr, Cr, Fe, and silicates, and mixtures thereof.
• the invention thus proposes a varnish that is hybrid and composite and that enables winding wires to be manufactured that, unexpectedly, present ability to withstand partial discharges that is greatly increased compared with wires coated in prior art varnish, particularly at high temperatures.
• thermoplastic or thermosetting resin is selected from the group comprising: polyamide imide (PAI), polyester imide (PEI), polyimide (PI), polyester (PE), polyurethane (PU), polyvinylacetal (PVA), and mixtures thereof.
• the copolymer is obtained by adding 10% to 50%, and preferably 20% to 40% by weight of alkoxysilane.
• the alkoxysilane can be a tetraalkoxysilane such as tetraethoxysilane (TEOS), or a trialkoxysilane such as trimethoxysilane or aminopropyl-trimethoxysilane. Nevertheless, it is also possible to envisage other silicon compounds capable of copolymerizing with the polymer.
• TEOS tetraethoxysilane
• trimethoxysilane aminopropyl-trimethoxysilane
• the mineral fillers are preferably added at a concentration of 2% to 20% by weight, with concentrations in the range 5% to 15% being particularly preferred.
• composition can be used as an insulating varnish for winding wires.
• the invention also provides a method of manufacturing the above-defined composition, the method comprising the following steps:
• thermoplastic or thermosetting resin with at least one alkoxysilane
• a mineral filler selected from compounds of B, Al, Ti, Zn, Zr, Cr, Fe, silicates, and mixtures thereof;
• the varnish In most applications, it is desirable for the varnish to have low viscosity. Under such circumstances, it is advantageous to add a solvent.
• suitable solvents are ortho-cresyl, meta-cresyl, para-cresyl, cresylic acid, N-methylpyrrolidone, dimethylacetamide (DMAC), and mixtures thereof, and they are particularly advantageous.
• the reaction between the organic portion, i.e. the polymer, and the mineral portion, i.e. the alkoxysilane, can be undertaken in the presence of a catalyst.
• This reaction is preferably performed with paratoluene sulfonic acid (pTSA), dibutyltin Bu 2 SnO, or polysiloxanes.
• pTSA paratoluene sulfonic acid
• dibutyltin Bu 2 SnO or polysiloxanes.
• polysiloxanes include, for example, polydimethyl siloxane, silikophen®, or silikophtal® (both sold by TEGO).
• the invention also provides a method of manufacturing such a winding wire, the method comprising the following steps:
• the invention also provides the winding wire obtained by the manufacturing method, and a coil comprising such a conductor wire covered in such a varnish.
• the resin is modified by adding inorganic compounds in conventional manner. Indications concerning suitable compounds and how to implement them can be found, for example, in patent WO 98/25277.
• the conductor wire made of a metal such as copper or aluminum, is coated in the varnish of the invention in conventional manner and is then dried.
• the varnish can be applied directly on the wire.
• a coating can be performed, for example, using tris(2-hydroxyethyl) isocyanurate (THEIC).
• TEEIC tris(2-hydroxyethyl) isocyanurate
• the varnish is set, preferably by heat treatment. Nevertheless, other treatments can be envisaged, for example using ultraviolet light.
• the winding wire coated in the varnish of the invention can subsequently be covered in additional layers.
• a polyesterimide was prepared in cresylic solvents by reacting a diamine such as methylene dianiline (MDA) and trimetllitic anhydride (TMA) and a hydrolyzed aromatic polyester.
• MDA methylene dianiline
• TMA trimetllitic anhydride
• the polyesterimide was modified by adding 10% to 50% alkoxysilane such as tetraethoxysilane (TEOS), trimethoxysilane, or aminopropyl-trimethylsilane, optionally in the presence of a catalyst such as pTSA, dibutyltin Bu 2 SnO, or a polysiloxane such as polydimethyl siloxane, silikophen®, or silikophtal®.
• alkoxysilane such as tetraethoxysilane (TEOS), trimethoxysilane, or aminopropyl-trimethylsilane
• a catalyst such as pTSA, dibutyltin Bu 2 SnO, or a polysiloxane such as polydimethyl siloxane, silikophen®, or silikophtal®.
• a polyesterimide was prepared in cresylic solvents by reacting a diisocyanate such as methylene diisocynate (MDI) with trimellitic anhydride (TMA) followed by esterification or transesterification in the presence of compounds possessing two or more hydroxyl bonds, such as tris(2-hydroxyethyl) isocyanurate (THEIC), dialcohols, glycols.
• a diisocyanate such as methylene diisocynate (MDI)
• TMA trimellitic anhydride
• TEEIC tris(2-hydroxyethyl) isocyanurate
• This polyesterimide was modified by adding 10% to 50% alkoxysilane such as tetraethoxysilane (TEOS), trimethoxysilane, or aminopropyl-trimethylsilane, optionally in the presence of a catalyst such as pTSA, dibutyltin Bu 2 SnO, or a polysiloxane such as polydimethyl siloxane, silikophen®, or silikophtal®.
• alkoxysilane such as tetraethoxysilane (TEOS), trimethoxysilane, or aminopropyl-trimethylsilane
• a catalyst such as pTSA, dibutyltin Bu 2 SnO, or a polysiloxane such as polydimethyl siloxane, silikophen®, or silikophtal®.
• a polyamide imide (PAI) was prepared in solvents of the N-methylpyrrolidone (NMP) or dimethylacetamide (DMAC) type by reacting a diisocyanate such as methyldiisocynate (MDI) with trimetllitic anhydride (TMA).
• NMP N-methylpyrrolidone
• DMAC dimethylacetamide
• MDI methyldiisocynate
• TMA trimetllitic anhydride
• the polyamide imide was modified by adding 10% to 50% alkoxysilane such as tetraethoxysilane (TEOS), trimethoxysilane, or aminopropyl-trimethylsilane, optionally in the presence of a catalyst such as pTSA, dibutyltin Bu 2 SnO, or a polysiloxane such as polydimethyl siloxane, silikophen®, or silikophtal®.
• alkoxysilane such as tetraethoxysilane (TEOS), trimethoxysilane, or aminopropyl-trimethylsilane
• a catalyst such as pTSA, dibutyltin Bu 2 SnO, or a polysiloxane such as polydimethyl siloxane, silikophen®, or silikophtal®.
• a polyimide of the Pyrel M® type (available from E. I. Dupont de Nemours & Co.) was modified by adding 10% to 50% alkoxysilane such as tetraethoxysilane (TEOS), trimethoxysilane, or aminopropyl-trimethylsilane, optionally in the presence of a catalyst such as pTSA, dibutyltin Bu 2 SnO, or a polysiloxane such as polydimethyl siloxane, silikophen®, or silikophtal®.
• alkoxysilane such as tetraethoxysilane (TEOS), trimethoxysilane, or aminopropyl-trimethylsilane
• a catalyst such as pTSA, dibutyltin Bu 2 SnO, or a polysiloxane such as polydimethyl siloxane, silikophen®, or silikophtal®.
• varnishes obtained in Examples 1 to 4 were applied to winding wires of diameter standardized by the IEC or the NEMA, using conventional techniques, e.g. by multiple coating or by spraying.
• the thickness of the varnish layer was preferably of grade 1, 2, or 3 in the IEC 60 317-0-1 classification or in the class single, heavy, or triple in the NW 1000 classification from the NEMA.
• winding wires of the invention presented improved ability to withstand peak-to-peak voltages of up to 3 kV at a frequency of up to 20 kHz with rise times of up to 1 kV/ ⁇ s at a temperature up to 180° C.

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• Chemical & Material Sciences (AREA)
• Engineering & Computer Science (AREA)
• Physics & Mathematics (AREA)
• Spectroscopy & Molecular Physics (AREA)
• Life Sciences & Earth Sciences (AREA)
• Materials Engineering (AREA)
• Wood Science & Technology (AREA)
• Organic Chemistry (AREA)
• Manufacturing & Machinery (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Organic Insulating Materials (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Insulated Conductors (AREA)
• Paints Or Removers (AREA)
• Macromonomer-Based Addition Polymer (AREA)
• Other Resins Obtained By Reactions Not Involving Carbon-To-Carbon Unsaturated Bonds (AREA)

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Cited By (11)

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Citations (9)

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• 2000
  • 2000-10-09 FR FR0012874A patent/FR2815038B1/fr not_active Expired - Fee Related
• 2001
  • 2001-10-05 US US09/970,682 patent/US20020041960A1/en not_active Abandoned
  • 2001-10-05 DE DE60114538T patent/DE60114538T2/de not_active Expired - Lifetime
  • 2001-10-05 ES ES01402575T patent/ES2250324T3/es not_active Expired - Lifetime
  • 2001-10-05 EP EP01402575A patent/EP1195775B1/de not_active Expired - Lifetime
  • 2001-10-05 AT AT01402575T patent/ATE308792T1/de not_active IP Right Cessation
  • 2001-10-09 JP JP2001311691A patent/JP2002206060A/ja active Pending
  • 2001-10-09 CN CNB011424141A patent/CN100432152C/zh not_active Expired - Fee Related

Patent Citations (10)

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