OXYALKYLENE POLYMER, CURABLE COMPOSITION, AND CURED ARTICLE

To provide a curable composition capable of adding higher hardness than prior art and capable of adding excellent hardness similar to prior art and higher elongation than prior art to cured article after curing, and an oxyalkylene polymer useful as a material of the curable composition.SOLUTION: There is provided an oxyalkylene polymer having 1.0 or more, as average, of a reactive silicon group represented by the following formula 1 in one main chain terminal, and number average molecular weight of 2,000 to 7,000. -SiXR(Formula 1), wherein R is a monovalent organic group having 1 to 20 carbon atoms, and represents an organic group other than a hydrolysis glass, X represents a hydroxyl group or a hydrolyzable group, a represents an integer of 1 to 3, when a is 1, R may be same or different each other, and when a is 2, X may be same or different each other.SELECTED DRAWING: None 【課題】硬化後の硬化物に対して、従来よりも高い硬度を付与すること、及び従来と同等の優れた硬度を付与し且つ従来よりも高い伸びを付与することができる、硬化性組成物、その硬化性組成物の材料として有用なオキシアルキレン重合体の提供。【解決手段】１つの主鎖末端に平均して１．０個より多くの下式１で表される反応性ケイ素基を有し、数平均分子量が２，０００〜７，０００であるオキシアルキレン重合体。−ＳｉＸａＲ３−ａ（式１）［式中、Ｒは炭素数１〜２０の１価の有機基であって、加水分解性基以外の有機基を示し、Ｘは水酸基又は加水分解性基を示す。ａは１〜３の整数を示す。ａが１の場合、Ｒは互いに同一でも異なってもよい。ａが２以上の場合、Ｘは互いに同一でも異なってもよい。］【選択図】なし