TECHNOLOGY FOCUS - INDUSTRIAL STANDARDS - The covering material has a flexural strength of 10-120 MPa, a flexural modulus of 30-3000 MPa as measured by a flexural properly test method for plastic described in JIS K7171, and a surface hardness of D30 to D99 as measured by a durometer hardness test method for plastic described in JIS K7215.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The fatty acid is a long-chain fatty acid having a hydroxyl group consisting of ricinolic acid, oxycaproic acid, oxycapric acid, oxyundecanoic acid, oxylinoleic acid, oxystearic acid and oxyhexanedecenoic acid. The polyol is a member consisting of ethylene glycol, propylene glycol, butylene glycol, hexamethylene glycol, diethylene glycol, trifunctional polyol including glycerol, trimethylolpropane or triethanolamine, tetrafunctional polyol including diglycerol or pentaerythritol, hexafunctional polyol including sorbitol, and octafunctional polyol including maltose or sucrose. The alkylene oxide is a member consisting of ethylene oxide, propylene oxide, butylene oxide and a-olefin oxide. The alcohol is a member consisting of ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, dihydric alcohol including 1,3-butanediol, 1,4-butanediol, 4,4'-dihydroxyphenylpropane or 4,4'-dihydroxyphenylmethane, and trihydric or polyhydric alcohol including glycerol, 1,1,1 -trimethylolpropane, 1,2,5-hexanetriol or pentaerythritol.    TECHNOLOGY FOCUS - POLYMERS - Preferred Components: The shape-retaining polymer contains an insulating curable polyurethane resin including polyol and polyisocyanate. The polyol has an oxygen content of less than or equal to 30% by mass and an iodine value of less than or equal to 200, and is a member consisting of polyester polyol, polyether polyol and polyol having a principal chain composed of a carbon-carbon bond. The polyester polyol is composed of a reaction product of a fatty acid and polyol. The polyether polyol is composed of an addition polymerization product of an alcohol and alkylene oxide. The polyol having the principal chain composed of carbon-carbon bond is a member consisting of acrylic polyol, polybutadiene polyol, polyisoprene polyol, hydrogenated polybutadiene polyol, polycarbonate polyol and polytetramethylene glycol (PTMG). The polyisocyanate is a member consisting of an aromatic polyisocyanate, an aliphatic polyisocyanate, an alicyclic polyisocyanate, carbodiimide-modified polyisocyanate obtained by modifying the polyisocyanate with carbodiimide, isocyanurate-modified polyisocyanate obtained by modifying the polyisocyanate with isocyanurate and an urethane polymer having an isocyanate group at the end of molecule, which is a reaction product of polyol and the excess polyisocyanate. The aromatic polyisocyanate is a member consisting of diphenylmethane diisocyanate (MDI), polymethylene polyphenylene polyisocyanate (crude MDI), tolylene diisocyanate (TDI), polytolylene polyisocyanate (crude TDI), xylene diisocyanate (XDI) and naphthalene diisocyanate (NDI). The aliphatic polyisocyanate is hexamethylene diisocyanate (HDI), and the alicyclic polyisocyanate is isophorone diisocyanate (IPDI).