| 摘要 |
PROBLEM TO BE SOLVED: To provide a polyolefinic resin form which can give a porous insulating coating and an expanded heat-shrinking tube having excellent flexibility, suppressed decrease in dielectric constant and improved cushioning properties and not having a risk of easily broken by external force even if the article is allowed to have a high expansion ratio for the purpose of e.g. reduction in weight, and to provide articles excellent in the above-mentioned properties. SOLUTION: This polyolefin resin foam satisfies the following relationships (1) and (2): Ts>=3.5÷Er<2/3> ...(1), and Sm<=30÷Er<2/3> ......(2) (wherein Ts is the tensile repture strength, Sm is the second modulus, and Er is the expansion ratio). The insulated wire is prepared by forming an insulating film comprising this foam around a conductor. The heat-shrinking tube is prepared by using this foam. |
