Reactive systems and a process for the preparation of modified duroplasts

A reactive system comprising:

• a) a storage stable mixture of (i) a polyisocyanate component containing at least one organic polyisocyanate and (ii) an epoxide component containing at least one organic epoxide which has been reacted in the presence of a tertiary amine as a catalyst to form an intermediate product which has a relatively high viscosity or is solid at room temperature and contains oxazolidinone and isocyanurate groups, the reaction being stopped by the addition of a quantity of alkylating sulphonic acid alkyl ester at least equivalent to the quantity of amine when at most 65% of the isocyanate groups present in the starting mixture have undergone reaction, and the quantitative ratios of components (i) and (ii) being chosen so that 100 g of component a) contain from 0.005 to 0.4 mol of epoxide groups,
• b) a polymer modifier which is a graft rubber,
• c) a catalyst and
• d) optionally auxiliary agents and additives, at most 100 g of component b) being used for 100 g of component a).

A process for the preparation of a synthetic resin containing isocyanurate groups comprising mixing components a), b), c) and optionally component d) of a reactive system, followed by converting the resultant resin mixture to a cross-linked state by supplying heat to the resin mixture and/or utilizing heat of reaction of the resin mixture and optionally shaping the resultant product, said process is characterized in that the reactive system comprises:

• a) a storage stable mixture of (i) a polyisocyanate component comprising at least one organic polyisocyanate and (ii) an epoxide component comprising at least one organic epoxide, in which the stability in storage has been ensured by a heat treatment of epoxide component (ii) in the presence of an alkylating agent, optionally carried out in the presence of at least a part of the polyisocyanate component (i), the quantitative ratios of components (i) and (ii) being chosen so that 100 g of component a) contain from 0.005 to 0.4 mol of epoxide groups,
• b) a polymer modifier which is a of graft rubbers,
• c) a catalyst and
• d) optionally auxiliary agents and additives.

A process for a two-stage production of a synthetic resin containing isocyanurate and oxazolidinone groups comprising mixing components a), b), c) and optionally d) of a reactive system, followed by converting the resultant resin mixture to a crosslinked state by supplying heat to the resin mixture or utilizing heat of reaction of the resin mixture, and optionally dissolving the resin mixture in a suitable solvent and optionally evaporating off the solvent, followed by homogenizing the resin mixture in an extruder at a temperature below 100.degree. C., and converting the resin mixture by shaping and further heating and optionally shaping into the final cross-linked state;

• said process is characterized in that the reactive system comprises:
• a) a storage stable mixture of (i) a polyisocyanate component containing at least one organic polyisocyanate and (ii) an epoxide component containing at least one organic epoxide which has been reacted in the presence of a tertiary amine as catalyst to form an intermediate product which has a relatively high viscosity or is solid at room temperature and contains oxazolidinone and isocyanurate groups, the reaction being stopped by the addition of a quantity of alkylating sulphonic acid alkyl ester at least equivalent to the quantity of amine when at most 65% of the isocyanate groups present in the starting mixture have undergone reaction, the quantitative ratios of components (i) and (ii) being chosen so that 100 g of component a) contain from 0.005 to 0.4 mol of epoxide groups,
• b) a polymer modifier which is a graft rubbers,
• c) a latent catalyst and optionally
• d) optionally auxiliary agents and additive