Abstract: The present invention relates to a crosslinkable polyester/isocyanate composition suitable for preparing composite manufactured articles endowed with high structural mechanical properties, by means of injection processes, comprising:A--a polyfunctional isocyanate;B--an unsaturated polyester resin, or a vinyl ester resin, or a mixture of both said resins, wherein said resin can contain free hydroxy groups;C--a free-radical polymerization initiator;D--a promoter of decomposition of (C) initiator;E--a catalyst of (A) isocyanate trimerization.

Abstract: Polymeric articles filled with glass fibers are prepared by methods used in paper making, starting from aqueous dispersions of glass fibers with polyolefinic fibrils having a high surface area, by deposition in sheets, drying and pressure-molding, optionally after bonding the sheets in a sandwich-like manner with an intermediate thermoplastic polymeric plate, not containing glass fibers, and having a modulus of flexure lower than that of the glass fibers contained in such sheets, so as to thermoweld said plate to the sheets.

Abstract: The halogen and organic substances content of the catalyst residues in alpha-olefin crystalline (co)-polymers prepared with catalysts obtained by reacting:(a) a metallorganic Al compound with(b) a Ti compound supported on a Mg halide, in which an electron-donor is combined with the Ti compound and/or the Mg compound and optionally with (a),are reduced by passing a stream of superheated steam (optionally mixed with other gaseous fluids) over the polymer in powder form at a temperature of 105.degree.-140.degree. C. and under a pressure of 0.1-10 kg/cm.sup.2 gauge, the steam/polymer ratio being comprised between 0.10 and 1 by weight.

Abstract: Catalysts useful in the polymerization of olefins, more particularly of ethylene and mixtures thereof with higher alpha-olefins and/or diolefins, are disclosed. The new catalysts are obtained by mixing a hydride or organometallic compound of a metal belonging to Groups I to III of the Mendelyeev Periodic System with the product obtained by contacting a titanium tetrahalide with a support comprising an anhydrous magnesium or zinc halide in an active form, under particular conditions.

Abstract: Solid polycarbonate is recovered continuously from solutions thereof in organic solvents by a process consisting of:(a) subdividing the polycarbonate solution by steam (water vapor) at either sonic or ultra-sonic speed by means of a De Laval type nozzle;(b) conveying the dispersion thus obtained into a tubular heat exchanger having an increasing cross-section, preferably spirally-shaped or with elbow stretches having a thermal exchange coefficient of 500-1500 Kcal/h.m.sup.2 .degree.C., in which the heat dispersion is kept at 100.degree.-140.degree. C. for periods of time comprised between 0.05 and 5 seconds;(c) separating the solid from the vapors in a cyclone;(d) drying of the solid in a water vapor fluid bed.

Abstract: There is disclosed an improvement in the production of microfibers or fibrils of synthetic thermoplastic polymeric materials by flash-spinning solutions, emulsions or suspensions of the synthetic polymers in solvents, under the action of a high-speed jet of gaseous or vaporous fluid having an angular direction with respect to the solution, emulsion or suspension being flash-spun. The improvement consists in causing the fluid jet to expand through a nozzle (or duct) of the convergent-divergent type and in extruding the polymer solution, emulsion or dispersion under flash conditions at an angle towards the fluid jet in expansion in the divergent portion of the nozzle.

Abstract: There are disclosed highly active supported catalysts for the polymerization of olefins to polymers in the form of spheroidal particles which neither break nor cake when subjected to compression. The supported catalysts are prepared by mixingA. a catalyst-forming component which is an organometallic compound of a metal belonging to Group II or III of the Mendelyeev Periodic TableWithB. a supported catalyst-forming component which is the product consisting of a carrier comprising an anhydrous Mg halide and of a halogenated Ti compound chemically combined with the carrier or dispersed on the same, said product being in the form of spherical or spheroidal particles of a size comprised between 1 and 350 microns and having characteristics as set forth in detail hereinbelow.