From insulate + -ive .
insulative (comparative more insulative , superlative most insulative )
Serving to insulate
1973 , The United States Patents Quarterly - Volume 178 [1] , page 267 :Housed resistors have their wire- wound cores embedded in an insulative material which is enclosed within the housing.
1995 , Electrical Overstress Electrostatic Discharge Symposium, Proceedings: 1995 [2] , →ISBN :The charge, that is applied and results in the measured voltage, may or may not pass through the insulative layer to the metallized film.
2012 , Niels Jonassen, Electrostatics [3] , →ISBN , page 132 :And although charged insulated conductors do appear in many practical, industrial as well as everyday, situations, there is no doubt that charged insulative materials are far more common.