| 摘要 |
<p>1,126,498. Insulating coating. SCHENECTADY CHEMICALS Inc. 27 Feb., 1967 [18 April, 1966], No. 9254/67. Heading B2K. [Also in Division C3] An insulating varnish for electrical conductors comprises (i) an oil-modified alkyd which is the reaction product of iso- and/or terephthalic acids, tris (2-hydroxyethyl) isocyanurate and unsaturated drying oil acids and (ii) a xylene-soluble phenol-formaldehyde resin in a varnish solvent which may be one or more of xylene, mineral spirits, isophorone, naphtha, toluene and benzene. The conductors may be Cu, Al, or Ag wires and the varnish may be applied directly thereto but it is preferably applied as a protective coat over two other coats of which the first is either a polyester of tris (2-hydroxyethyl) isocyanurate and an aromatic dicarboxylic acid (e.g. as described in Specification No. 978717 and optionally modified with an organic titanate or a polyisocyanate as described therein) or a polyester-imide which may be similarly modified (e.g. as described in Specification No. 324/66,, and contains also, in either case 1 to 5% of a melamine-, phenol-, cresol-, or xylenol-formaldehyde resin. The second coat is preferably polyethylene terephthalate but may also be a polyimide, polyesterimide or polyamideimide. In example the varnish of the invention is applied by dipping to a motor starter or to copper wire which has previously been coated in conventional manner with the two above mentioned coats. Reference has been directed by the Comptroller to Specification 961,624.</p> |
