Polyrotaxane, thermally curable composition including said polyrotaxane, thermally cured crosslinked object, production method for polyrotaxane, and production method for thermally cured crosslinked object

A method for producing a thermoset crosslinked body, comprising the steps of:

• a) preparing a polyrotaxane, in which capping groups each locates at each end of a pseudopolyrotaxane, which has a linear molecule and a cyclic molecule(s) having a hydroxyl group(s) in which the linear molecule is included in a cavity (cavities) of the cyclic molecule(s) in a skewered manner, in order to prevent the dissociation of the cyclic molecule(s),
• b) mixing and reacting a compound, which serves as a source of a group having an ability to inactivate a hydroxyl group that is converted to a group having an ability to inactivate a hydroxyl group, to and with the polyrotaxane to inactivate a part of the hydroxyl group(s);
• to obtain a polyrotaxane having a hydroxyl value of 10 to 65 mgKOH/g, and
• d) mixing the obtained polyrotaxane with a material which reacts with a hydroxyl group(s) of the polyrotaxane, to cure, and reacting the resultant by applying heat;
• to obtain the thermoset crosslinked body,
• wherein the material comprises one selected from the group consisting of polycarbonates with terminal isocyanate modification, polypropylene glycol with terminal isocyanate modification, a polyacryl ester having an isocyanate side chain, polycarbonates with terminal isothiocyanate modification, a polyacrylic acid ester having an isothiocyanate group in a side chain, an acid-anhydride-modified polypropylene, polyethylene glycol with terminal epoxy-modification, and acryl polymers modified with carboxylic acid group.