1309226 Isocyanurate group-containing polymers and cellular products thereof OWENSCORNING FIBERGLAS CORP 30 April 1971 12532/71 Headings C3C and C3R Isocyanate group-containing polymers contain as smoke reducing agents an alkali metal fluoroborate, ammonium fluoroborate or mixtures thereof. The isocyanurate group containing polymers may be prepared by trimerization of compounds containing -NCO groups, optionally in the presence of a polyol, e.g. a polyether or polyester, in which case the polymer also contains urethane groups and/or a blowing agent, e.g. trichloro-fluoromethane, to form cellular products. The smoke reducing agent is suitably used in an amount of 0À1 to 30% by weight of synthetic resin solids, i.e. the isocyanate, polyol, surfactant (if any), and catalyst used in the preparation of the resin.