Polycarbodiimide composition, method for producing a polycarbodiimide composition, water-dispersed composition, solution composition, resin composition, and cured resin

A method for producing a polycarbodiimide composition, the method including the steps of:

• a urethane-forming step, in which polyisocyanate having a primary isocyanate group and alcohol are subjected to urethane-forming reaction, and
• a carbodiimide-forming step, in which the reaction product in the urethane-forming step is heated in the presence of a carbodiimide-forming catalyst to cause carbodiimide-forming reaction,
• wherein
• the alcohol contains
• at least one oxyethylene-containing alcohol containing an oxyethylene group, and
• at least one oxyethylene-noncontaining alcohol containing no oxyethylene group, and
• the at least one oxyethylene-noncontaining alcohol has a solubility parameter of 11.20 (cal/cm3)1/2 or less.