Patent GB-785241-A (GB)
Title: Improvements in or relating to insulated wire
Inventor: DANNENBAUM HANS
IPC: B05D7/24
Filed: 1955-05-25
Abstract: Insulated wire is obtained by applying an unsaturated polyester resin and an unsaturated monomer, which acts as solvent, to the travelling bare or fibre covered, e.g. glass fibre covered, wire and copolymerizing the mixture thereupon by heating with a peroxide catalyst.  One or more coatings may be applied and in an example the wire is of copper.  The polyester may be derived from ethylene, diethylene and triethylene glycols, butanediols and hexanediol; glycerine, hexanetriol, trimethylol-propane or monoethers thereof; dehydrated castor oil fatty acid monoglyceride; unspecified unsaturated polyhydric alcohols; succinic, glutaric, adipic, sebacic, citric and phthalic acids; and maleic, fumaric, itaconic and aconitic acids.  A non-sticky lacquer surface is obtained by introducing ether oxygen into the polyester, e.g. by using polyglycols, glycerine monoethers, or ether-carboxylic acids such as diglycollic acid.  The unsaturated monomer may be styrene, dichlorostyrene, vinyl toluene or carbazole, unspecified ethers, cyanuric acid esters and esters of allyl alcohol or of maleic or aconitic acids, e.g. the purified compounds diallyl maleate, triallyl aconitate and the mixed triethylene glycol/diallyl ester of maleic acid.  Catalysts specified are benzoyl, dichlohexyl and cyclohexanone peroxides and t-butyl perbenzoate and these may be used singly or in an admixture graduated by temperature sensitivity.  Accelerators such as cobalt, manganese or lead soaps may also be included. Polymerization may be effected in a number of successive elevated temperature zones and the coated wire may first be subjected to gellation or initial polymerization in an oven or infra-red installation.  To prevent premature polymerization in the storage tank the mixture may be cooled till used, or an inhibitor such as a polyvalent phenol or quaternary ammonium salt, e.g. hydroquinone, benzoquinone or pyrocatechin, may be included, or air may be excluded.  Improved products may be obtained if the polyester is washed with water to remove uncombined residues. Further, the polyester may also be purified by reacting free hydroxy or carboxyl groups with cobalt, manganese or lead carbonate, hydroxide or acetate, which introduces an accelerator, or with isocyanates or modified isocyanates, e.g. toluylene diisocyanate or the reaction products of diisocyanates with unsaturated mono- or poly-hydroxylic compounds, for example toluylene - mono - allyl - urethanemonoisocyanate.  Alternatively residual carboxyl groups may be reacted with xylene-formaldehyde resins which also cross-link with the double bonds of the co-monomer.  Silicone groups may optionally be introduced into the polyester.  The physical properties of the lacquered wires may be further improved by thermal after-treatment.ALSO:Insulated wire is obtained by applying an unsaturated polyester and an unsaturated monomer, which acts as solvent, to the travelling bare or fibre-covered, e.g. glass fibre covered, wire and copolymerizing the mixture thereupon by heating with a peroxide catalyst.  One or more coatings may be applied and in an example the wire is of copper.  The polyester may be derived from ethylene, diethylene and triethylene glycols, butanediols and hexanediol; glycerine, hexanetriol, trimethylol-propane or monoethers thereof; dehydrated castor oil fatty acid monoglyceride; unspecified unsaturated polyhydric alcohols; succinic, glutaric, adipic, sebacic, citric and phthalic acids; and maleic, fumaric, itaconic and aconitic acids.  A non-sticky lacquer surface is obtained by introducing ether oxygen into the polyester, e.g. by using polyglycols, glycerine monoethers, or ether-carboxylic acids such as diglycollic acid.  The unsaturated monomer may be styrene, dichlorostyrene, vinyl toluene or carbazole, unspecified ethers, cyanuric acid esters and esters of allyl alcohol or of maleic or aconitric acids, e.g. the purified compounds diallyl maleate, triallyl aconitate and the mixed triethylene glycol/diallyl ester of maleic acid.  Catalysts specified are benzoyl, dicyclohexyl and cyclohexanone peroxides and t-butyl perbenzoate and these may be used singly or in an admixture graduated by temperature sensitivity.  Accelerators such as cobalt, manganese or lead soaps may also be included. Polymerization may be effected in a number of successive elevated temperature zones and the coated wire may first be subjected to gellation or initial polymerization in an oven or infra-red installation.  To prevent premature polymerization in the storage tank the mixture may be cooled till used, or an inhibitor such as a polyvalent phenol or quaternary ammonium salt, e.g. hydroquinone, benzoquinone or pyrocatechin, may be included, or air may be excluded.  Improved products may be obtained if the polyester is washed with water to remove uncombined residues. Further the polyester may also be purified by reacting free hydroxy or carboxyl groups with cobalt, manganese, or lead carbonate, hydroxide or acetate which introduces an accelerator, or with isocyanates or modified isocyanates, e.g. toluylene diisocyanate or the reaction products of diisocyanates with unsaturated mono- or polyhydroxylic compounds, for example toluylenemono-allyl-urethane-monoisocyanate. Alternatively residual carboxyl groups may be reacted with xylene-formaldehyde resins which also cross-link with the double bonds of the comonomer.  Silicone groups may optionally be introduced into the polyester.  The physical properties of the lacquered wires may be further improved by thermal after-treatment.