Abstract: A method of producing a polyoxalate resin including polycondensing a dialkyl oxalate represented by formula (2): wherein R represents an alkyl group having 1 to 4 carbon atoms, with a saturated aliphatic diol represented by formula (3): HO-A-OH, wherein A represents a divalent saturated aliphatic hydrocarbon group having 3 to 12 carbon atoms, in which polycondensation reaction product, the molar amount of the dialkyl oxalate [M1] and the molar amount of the saturated aliphatic diol [M2] satisfy relationship (I): 0.5?[M2]/[M1]<1 while controlling the total content of water in the starting reaction mixture to 2,000 ppm or less.

Abstract: A biodegradable polyoxalate resin having a high melt-formability by the formula: X?O-A-O—CO—CO?nY in which A=C3-C12 divalent aliphatic hydrocarbon group, X=H; R—OCOCO— or OHC— group, Y=—OR, —OAOH or —OAOCHO when X=H—, or —OR or —OAOCHO when X=R—OCOCO— or OHC—, R=C1-C4 alkyl, and is usable in a resinous composition with a poly(lactic acid) resin.

Abstract: A fusion-bondable sheet is provided which is used as an overtape for covering a joint portion of a heat-shrinkable cover sheet applied onto a joint of steel pipe or cable and which is also used as a cover sheet for repairing a damaged protecting cover of a steel pipe. The fusion-bondable sheet comprises (a) a crosslinked polyolefin sheet, (b) a fusion-bondable layer formed on one surface of the crosslinked polyolefin sheet, which layer is mainly composed of a polyolefin having a melting point of 80.degree.-200.degree. C., a polyolefin having a melting point of 30.degree.-75.degree. C. and a tackifier, and (c) a flame-retardant sheet bonded to the other surface of the crosslinked polyolefin sheet through a binder or adhesive layer. Preferably, the flame-retardant sheet is larger in size than the crosslinked polyolefin sheet and the edges of the former sheet outwardly extend from the edges of the latter sheet.