To provide a material compsn. which is applicable to the parts requiring a high expansion and contraction ratio, is lowered in toxicity and is improved in tear strength, etc., by compounding multifuntional isocyanate and plural kinds of compds. having a prescribed number of functional groups making polynm. addition reaction with isocyanate groups at prescribed mol.wts. respectively at prescribed ratios, thereby forming this compsn.
The multifunctional isocyanate is defined as a component (a). The compds. which have two pieces of the functional groups (hereafter described as the similar merely functional groups) making the polyaddition reaction with the isocyanate groups and are respectively 60 to 3500 and ≤500 in the mol.wt. are respectively defined as components (b), (c). The compd. which have the mol.wt. of ≤700 and have ≥3 pieces of the similar functional groups is defined as a component (d). The functional group quantities of the respective components per 100mol of the isocyanate groups of the component (a) are specified to 1 to 35mol in total quantity of the functional groups in the case of the components (c) and (d), to 0.1 to 18mol in the case of the component (d) and 60 to 100mol in the case of the component (b). The total quantity of the functional groups of the components (b), (c), (d) is similarly specified to 80 to 110mol per 100mol isocyanate groups of the component (a).
HIRAOKA KYOKO
KIDOKORO HIROTO
