Abstract: A device for separating a high pressure polyphase mixture consisting of a gas charged with liquid particles, and particularly a mixture of ethylene and polyethylene, which comprises a cylindrical vertical enclosure into which extends an inlet means for supplying the mixture thereto and which is provided at its lower end with an outlet for discharging separated liquids; a vertical cyclone in communication with the enclosure for receiving separated gases therefrom and having an outlet at its upper end for discharging gases separated in the cyclone and a liquid outlet at its lower end for discharging separated liquids therefrom; and an ejector comprising a nozzle, through which the polyphase mixture is fed, a mixing zone connected to the liquid outlet of the cyclone and a diffuser section for reducing the speed of the resultant mixture and being connected to the inlet means for supplying the polyphase mixture to the enclosure.

Abstract: The danger of explosion due to decomposition of high-pressure industrial process gases, such as ethylene, is reduced by beginning to cool the decomposition gases with a delay of no more than 25 milliseconds from the onset of flow of the gases out of a high-pressure vessel. The process may be implemented by using apparatus comprising: (1) means containing an inert gas at a pressure P between about 5 and 50 bars and an inert liquid of high heat of vaporization; and (2) a valve located upstream of an inert-liquid dispersing means, of which the opening is operated by a means detecting the opening of a safety means of the high-pressure vessel and operating the working of the dispersing means.

Abstract: An apparatus for evacuating the gases resulting from the decomposition of industrial process gases, such as ethylene, contained in a vessel under high pressure is adjacent to the vessel. The apparatus comprises:(1) at least one safety means separating the apparatus from the vessel;(2) a reservoir with a volume which is 2 to 100 times that of the vessel;(3) at least one connecting pipe between the vessel and the reservoir; and(4) at least one chimney between the reservoir and the atmosphere.The apparatus is useful for the recovery of decomposition gases for the purpose of preventing atmospheric pollution. The risk of explosion is reduced by evacuating decomposition gases through the apparatus.

Abstract: A cold-stretchable, self-adhesive film composition comprising (a) from 88 to 97% by weight of an ethylene-.alpha.-olefin copolymer, the .alpha.-olefin having from 3 to 10 carbon atoms and the copolymer having a density of between 0.905 and 0.940 g/cm.sup.3 and a melt index of between 0.1 and 2 dg/minutes and; (b) from 3 to 12% by weight of a polymer selected from among polyisobutylene, atactic polypropylene, cis-polybutadiene and bromobutyl rubber. The film compositions find particular use in the automation of the spiral wrap-round packaging technique.

Abstract: The danger of explosion due to decomposition of high-pressure industrial process gases, such as ethylene, is reduced by beginning to cool the decomposition gases with a delay of no more than 25 milliseconds from the onset of flow of the gases out of a high-pressure vessel.The process may be implemented by using apparatus comprising:(1) means containing an inert gas at a pressure P between about 5 and 50 bars and an inert liquid of high heat of vaporization; and(2) a valve located upstream of an inert-liquid dispersing-means, of which the opening is operated by a means detecting the opening of a safety means of the high-pressure vessel and operating the working of the dispersing means.The apparatus is useful for the recovery of decomposition gases in order to avoid atmospheric pollution, as well as for reducing the risk of explosion.

Abstract: A catalyst system for use in the polymerization of ethylene under high pressure and temperature containing an alkyl-aluminum or alkylsiloxalane activator and a compound of the formula:(TiCla) (MgCL.sub.2).sub.y (AlCl.sub.3)z (RMgCl).sub.bin whicha is from 2 to 3;y is 2 or more;z is from 0 to 1/3;b is from 0 to 1; andR is an aliphatic or aromatic hydrocarbon radical.

Abstract: In a process for hardening phenol-formaldehyde resol resins, comprising conducting the hardening of the resins with an acidic solution of water and/or an organic solvent having dissolved therein an aromatic sulphonic acid and/or concentrated sulphuric acid, the improvement comprising the hardening in the presence of aniline added to the phenolic resin beforehand in a quantity of between about 0.5 and 2% relative to the weight of the phenolic resin whereby the pot life is extended and the cure time is satisfactory, the resultant products being especially useful as prepegs.

Abstract: Acrylic prepolymer comprising:from 10 to 50% by weight of units derived from at least one alkyl acrylate, the alkyl group having from 4 to 12 carbon atoms,from 30 to 60% by weight of units derived from at least one alkyl methacrylate, the alkyl group having from 1 to 5 carbon atoms, andfrom 10 to 40% by weight of units derived from methyl acrylate.The prepolymer is used to encapsulate photocells, connected to one another by conducting wires and positioned on a support plate, by casting a resin into the space located between the support plate and a second protective plate, the resin being obtained by mixing 100 parts of the acrylic prepolymer, from 0.1 to 4 parts of a vanadium arenesulphonate and from 0.5 to 4 parts of a free-radical initiator, at a temperature between 10.degree. and 70.degree. C. and for a sufficient time to solidify the polymeric resin at the temperature selected.

Abstract: An apparatus for evacuating the gases resulting from the decomposition of industrial process gases, such as ethylene, contained in a vessel under high pressure is adjacent to the vessel. The apparatus comprises:(1) at least one safety means separating the apparatus from the vessel;(2) a reservoir with a volume which is 2 to 100 times that of the vessel;(3) at least one connecting pipe between the vessel and the reservoir; and(4) at least one chimney between the reservoir and the atmosphere.The apparatus is useful for the recovery of decomposition gases for the purpose of preventing atmospheric pollution. The risk of explosion is reduced by evacuating decomposition gases through the apparatus.

Abstract: A catalyst comprising the product obtained by bringing into contact (a) a compound of magnesium comprising at least one species selected from the group consisting of magnesium monohalides (MgX), halo-magnesium hydrides (HMgX) and magnesium hydride (MgH.sub.2), X being a halogen and the said species MgX or HMgX being obtained by thermal decomposition of a powdery organo-magnesium halide R.sub.1 MgX wherein R.sub.1 is an organic radical; and (b) at least one halide of a transistion metal selected from the group consisting of titanium and vanadium, the valency of said metal in said halide being lower than or equal to 3, the quantities of (a) and (b) being such that the atomic ratio of magnesium to said transistion metal is between 1 and 25, and a catalyst system including the catalyst that is suitable for use in the polymerization of olefins and particularly ethylene.

Abstract: Polyethylene is produced in at least one reactor under a pressure of 800 to 2500 bars and a temperature of 150.degree. to 350.degree. C., and the reaction mixture exiting the reactor through an expansion valve and supplied to a separator under a pressure of 50 to 400 bars is cooled by passing a flow Q of the mixture through a turbine. The turbine comprises at least one stage with a fixed nozzle and a bladed wheel having a rotation speed of between 12,000 and 40,000 r.p.m. Ethylene discharged from the separator is recycled to the inlet of a compressor, and the discharge from the compressor is supplied to the reactor.

Abstract: An organometallic halide having the formula:(RMX) (MX.sub.2).sub.a (MR.sub.2).sub.b (MH.sub.2).sub.cwherein a.ltoreq.0.45, b.ltoreq.0.15, and c.ltoreq.0.30, X is a halogen, R is a hydrocarbon radical, and M is a metal selected from the group consisting of magnesium, zinc, beryllium, and calcium is prepared by a continuous dry process by reacting an organic monohalide RX and a metal M in the form of convex solid grains of a size between 1 and 15 mm. The reaction temperature is lower than the temperature at which decomposition of the organometallic halide RMX begins and at least 10.degree. C. higher than the boiling point of the organic monohalide. The reaction may also take place in the presence of an organometallic derivative comprising a hydroxy group or an enolysable ketone group. The resulting organometallic halide may be used for the synthesis of anhydrous magnesium halide or for the reduction of titanium tetrachloride.

Abstract: A distribution cap for a multitubular falling heat exchanger, in which the exchanger has a bundle of parallel tubes, an entrance channel for the tubes and a perpendicularly disposed distribution plate surrounding the entrance end of the tubes, the distribution cap is located in the entrance channel above the distribution plate and over the entrance ends of the tubes, and has cylindrical sidewalls and a closed top having sides that slope downwardly toward the cylindrical sidewalls of the cap.

Abstract: A halogen-containing catalyst for the polymerization of ethylene or copolymerization of ethylene and .alpha.-olefins having from 3 to 8 carbon atoms and a process for their preparation. The catalyst has the general formula: M.sub.n Mg(OR).sub.2-m X.sub.m+4n, wherein M is a metal of groups IVa to VIa of the Periodic Tables, X is a halogen, R is an alkyl radical containing from 1 to 4 carbon atoms, 0<m<2, and 0.05<n<1.

Abstract: Polyethylene is produced in at least one reactor under a pressure of 800 to 2500 bars and a temperature of 150.degree. to 350.degree. C., and the reaction mixture exiting the reactor through an expansion valve and supplied to a separator under a pressure of 50 to 400 bars is cooled by passing a flow Q of the mixture through a turbine. The turbine comprises at least one stage with a fixed nozzle and a bladed wheel having a rotation speed of between 12,000 and 40,000 r.p.m. Ethylene discharged from the separator is recycled to the inlet of a compressor, and the discharge from the compressor is supplied to the reactor.

Abstract: The danger of explosion due to decomposition of high-pressure industrial process gases, such as ethylene, is reduced by maintaining in an inert atmosphere at least part of an evacuation system included between a pressurized vessel within which the decomposition may take place, on the one hand, and the atmosphere, on the other.

Abstract: Acrylic prepolymer comprising:from 10 to 50% by weight of units derived from at least one alkyl acrylate, the alkyl group having from 4 to 12 carbon atoms,from 30 to 60% by weight of units derived from at least one alkyl methacrylate, the alkyl group having from 1 to 5 carbon atoms, andfrom 10 to 40% by weight of units derived from methyl acrylate.The prepolymer is used to encapsulate photocells, connected to one another by conducting wires and positioned on a support plate, by casting a resin into the space located between the support plate and a second protective plate, the resin being obtained by mixing 100 parts of the acrylic prepolymer, from 0.1 to 4 parts of a vanadium arenesulphonate and from 0.5 to 4 parts of a free-radical initiator, at a temperature between 10.degree. and 70.degree. C. and for a sufficient time to solidify the polymeric resin at the temperature selected.

Abstract: An ethylene polymerization catalyst having the general formula M.sub.n Mg(OR).sub.2+4n-m X.sub.m, wherein R is an alkyl radical containing from 1 to 4 carbon atoms, M is a transition metal of groups IVa to VIa of the Periodic Table, X is a halogen, 0.05.ltoreq.n.ltoreq.0.6 and 0<m<n+1.

Abstract: Shaped articles of polybut-1-ene are made by preheating a polymer blank in the crystalline form II at a temperature between 20.degree. and 90.degree. C. The preheated blank is then press-forged under a pressure between 8 and 100 kgf/mm.sup.2 for a period of 1-40 seconds. During the shaping operation, the polymer is converted into the crystalline form I. Polybut-1-ene shaped articles are formed that have a melting peak, determined by differential thermal analysis, at 119.degree. C.

Abstract: Process and device for cooling a mixture of polymer and monomer from a reactor in which ethylene is polymerized or copolymerized at a pressure greater than 1,000 bars between a pressure-reduction valve located downstream of the reactor and a medium pressure separator. The cooling is achieved by injecting monomer at a pressure below that of the separator using a device with a nozzle distance S.sub.1 and corresponding cross-section A.sub.1 the mixture from the reactor passes, a convergent mixing zone in which the mixture is mixed with the monomer injected, which is supplied at a flow rate q, and a diffuser of throat distance S.sub.3 and corresponding cross-section A.sub.3, which makes it possible to bring the mixture to the pressure of the separator. The dimensions of the device are such that the ratio Q/A.sub.1 is between 0.20 and 1.35 t/hr.mm.sup.2 and the ratio ##EQU1## is between 0.1 and 0.3 t/hr.mm.sup.2.