Method for producing a polyisocyanate polymer and a polyisocyanurate plastic

A process for producing a composite material having a matrix comprising a polyisocyanurate plastic, comprising

• a) providing a reaction mixture comprising a component having isocyanate-reactive groups, wherein a molar ratio of isocyanate groups to isocyanate-reactive groups is at least 3:1, the reaction mixture comprising
• (i) a polyisocyanate composition A,
• (ii) a catalyst B1 that catalyzes the reaction of isocyanate groups to give uretdione groups, and
• (iii) a catalyst B2 that catalyzes the reaction of isocyanate and uretdione groups to give isocyanurate groups, wherein catalyst B1 is different than catalyst B2;
• b) wetting a fiber, a woven fabric, a nonwoven scrim or a knit with the reaction mixture;
• and
• c) catalytically polymerizing the polyisocyanate composition A to give a polyisocyanate polymer C that forms a layer on the fiber, the woven fabric, the nonwoven scrim or the knit, wherein the polyisocyanate polymer C has a modulus G″ of ≥1*106 Pa as determined by a plate/plate rheometer at 1/s at 23° C. based on ISO 6721-10:2015-09 and comprises uretdione groups, and wherein the catalytic polymerization is conducted at an average temperature of not more than 100° C. over a period of 30 minutes up to 14 days;
• and
• d) comprising catalytically trimerizing polyisocyanate polymer C to give a polyisocyanurate plastic D at a temperature of at least 100° C., wherein the temperature in process step d) is at least 20° C. higher than the temperature in process step c).

A process for producing a polyisocyanurate plastic D, comprising

• a) providing a polyisocyanate polymer C having a modulus G″ of at least 1*106 Pa as determined by a plate/plate rheometer at 1/s at 23° C. based on ISO 6721-10:2015-09, comprising
• (i) uretdione groups;
• and
• (ii) a catalyst B2 that catalyzes the reaction of uretdione groups to give isocyanurate groups;
• obtained by
• a1) providing a reaction mixture comprising a component having isocyanate-reactive groups, wherein a molar ratio of isocyanate groups to isocyanate-reactive groups is at least 3:1, the reaction mixture comprising
• (i) a polyisocyanate composition A,
• (ii) a catalyst B1 that catalyzes the reaction of isocyanate groups to give uretdione groups, and
• (iii) a catalyst B2 that catalyzes the reaction of isocyanate and uretdione groups to give isocyanurate groups, wherein catalyst B1 is different than catalyst B2;
• and
• a2) catalytically polymerizing the polyisocyanate composition A to give the polyisocyanate polymer C;
• wherein the polymerization to give the polyisocyanate polymer C is conducted at an average temperature of not more than 100° C. over a period of 30 minutes up to 14 days, and
• b) catalytically trimerizing polyisocyanate polymer C to give a polyisocyanurate plastic D at a temperature between 100° C. and 400° C., wherein the temperature in catalytically trimerizing polyisocyanate polymer C to give polyisocyanate plastic D is at least 20° C. higher than the temperature in catalytically polymerizing the polyisocyanate composition A to prepare the polyisocyanate polymer C.