The present invention relates to a composition containing, besides a thermosetting resin of epoxy type and a hardener of anhydride type, at least one catalyst comprising an organometallic titanium complex. This composition enables the manufacture of vitrimer resins, that is to say resins that can be deformed in the thermoset state. It also relates to a kit for manufacturing this composition, an object obtained from this composition and a kit for manufacturing this object. Another subject of the invention relates to an organometallic titanium complex corresponding to the structure titanium bis(3-phenoxy-1,2-propane dioxide) (Ti(PPD).sub.2), and the use thereof as vitrimer effect catalyst in systems based on epoxy resin and on hardener of anhydride type.

A resin composition for fiber-reinforced plastic having a good balance between stability and curability and capable of producing fiber-reinforced plastic with improved strength. The composition contains an epoxy resin, an acid anhydride, and a catalyst that is liquid at 25 C. The catalyst is at least one member selected from the group consisting of a compound composed of an acid and a base and a compound composed of a quaternary onium cation and an anion.