THERMOPLASTIC POLYESTER RESIN AND INSULATED ELECTRIC WIRE, INSULATED ELECTRIC CABLE AND HEAT-SHRINKABLE TUBE PRODUCED BY USING THE RESIN

摘要

PROBLEM TO BE SOLVED: To obtain a new thermoplastic polyester resin having excellent flexibility, abrasion resistance, thermal aging resistance, electrical insulation, etc., by using a specific monomer unit as the constituent unit and specifying the melt index of the resin. SOLUTION: The objective thermoplastic polyester resin contains a unit composed of (A) an aromatic dicarboxylic acid (preferably methyl terephthalate, etc.), and/or an aliphatic dicarboxylic acid, (B) an aliphatic oxycarboxylic acid (preferablyε- caprolactone) and (C) an aliphatic dicarboxylic acid having C-C unsaturated bond (preferably fumaric acid) as the acid component and a unit composed of (D) an aliphatic diol (preferably 1,4-butanediol, etc.), as the glycol component and is expressed by formula I or II (Ra1 is an aromatic and/or aliphatic hydrocarbon group originated from the component A; Ra2 is a hydrocarbon group originated from the component B; Ra3 is an aliphatic hydrocarbon group having C=C bond and originating from the component C; Rb is a hydrocarbon group originating from the component D; (l), (m), (n) and (q) are each a positive integer). The melt index (MI: 230 deg.C, under 2.16 kg load) of the resin is adjusted to 1-50.