Abstract: An embossed ethylene-propylene copolymer film having a thickness of less than or equal to 24 microns. A method and apparatus for making the film by blow-extruding the ethylene-propylene copolymer into a tubular web, pinching the tubular web between pinch rolls, and embossing the pinched web by passing it between an embossing roll and a pressure roll.

Abstract: A composite film for packaging foods having at least one layer of a thermoplastic film of low density polyethylene, polypropylene, polybutene, polyamide, polystyrene or polyvinyl chloride having a thickness between 25 and 3,000 .mu.m, and another layer of a terpolymer film having a thickness between 10 and 100 .mu.m.The terpolymer film contains from 88 to 98.7 mol % of units derived from ethylene, from 1 to 10 mol % of units derived from an ester of an alkyl acrylate or an alkyl methacrylate, the alkyl group having from 1 to 6 carbon atoms, and from 0.3 to 3 mol % of units derived from maleic anhydride.

Abstract: A composition for the manufacture of hot-melt adhesives, in which the improvement comprises a terpolymer of ethylene having a melt index between 5 and 500 dg/minute and comprising from 1 to 10 mol % of units derived from an ester selected from alkyl acrylates and methacrylates, the alkyl group having from 1 to 6 carbon atoms, and from 0.3 to 3 mol % of units derived from maleic anhydride. The composition also contains at least one tackifying resin and may contain at least one compound selected from paraffin, microcrystalline polymeric wax, and esters of a hydrogenated rosinic acid and of a lower alcohol.

Abstract: A catalyst for polymerizing ethylene, especially at high temperature and high pressure, comprising at least two halogen compounds of transition metals, one of which is a titanium trichloride syncrystallized with aluminum chloride. The catalyst has the formula(TiCl.sub.3, 1/3AlCl.sub.3)(MX.sub.3).sub.x (MgX.sub.2).sub.ywherein 0.3.ltoreq.x.ltoreq.3, 0.ltoreq.y.ltoreq.20, M is a transition metal of Groups V B and VI B of the Periodic System, and X is a halogen. The second transition metal is preferably vanadium, chromium, molybdenum, or tungsten. The catalyst is made by subjecting titanium trichloride syncrystallized with aluminum chloride, the trivalent halide of M, and, optionally, anhydrous magnesium halide to a milling step in which the milling energy is at least equal to three kWh per kg of solid material treated, which results in a binary solid solution structure Ti-M of which the dimension of crystallites is less than or equal to 100 Angstroms.

Abstract: An organometallic halide having the formula:(RMX)(MX.sub.2).sub.a (MR.sub.2).sub.b (MH.sub.2).sub.cwherein a.congruent.0.45, b.congruent.0.15, and c.congruent.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: The energy efficiency of a high pressure, high temperature continuous process for the production of polyethylene is improved and residual gases are more completely removed from the product without detriment to product quality by employing an intermediate separator between the first and second separators. The intermediate separator is maintained at a pressure between about 10 and 70 bars, and the second separator is maintained at a pressure between about 1 and 1.5 bars.

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: A catalytic component having the formula(MX.sub.a) (MgX.sub.2).sub.b (RMgX).sub.c (MHgX).sub.dwherein M is a metal selected from group VI B and group V B of the Periodic Classification, X is a halogen, R is a hydrocarbon radical, 2.ltoreq.a .ltoreq.3.5, 1.ltoreq.b.ltoreq.30, 1.ltoreq.c.ltoreq.8 and 0.ltoreq.d.ltoreq.10 is prepared by reducing a metallic halide of the metal M, the valency of said metal being 4 if a metal of group IV B is concerned and 4 or 5 if a metal of group V B is concerned, by means of at least one organomagnesium compound having the formula RMgX, the said organomagnesium compound being used in the solid state and reduction of the metallic halide being carried out under a pressure lower than or equal to atmospheric pressure and at a temperature lower than the decomposition point of said organomagnesium compound under the pressure concerned but at least 10.degree. higher than the boiling point or sublimation point of the metallic halide under the pressure concerned.

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: A process and apparatus for widening the molecular distribution of ethylene polymers produced at high pressure and at high temperature by polymerizing ethylene at a pressure between 600 and 3,000 bars and at a temperature between 160.degree. C. and 320.degree. C., in two reactors operating in parallel. In the first reactor, the reaction takes place in the presence of less than 0.1% of hydrogen for the purpose of producing a polymer of high molecular weight. In the second reactor, the reaction takes place in the presence of 0.2 to 5% of hydrogen for the purpose of fabricating a polymer of low molecular weight. The effluents from these two reactors are expanded and then moved to a set of two separators interconnected so as to efficiently mix the polymers produced in the two reactors by recycling the least possible amount of hydrogen into the supply circuit of the first reactor in such manner that the proportion of hydrogen in the first reactor remains less than 0.1% in moles.

Abstract: New organo-lithium initiators, their synthesis, and their use. The initiators have the formula: ##STR1## in which R" is either a hydrogen atom or a methyl radical; either n is 1, in which case R'=H and m and p are integers, the sum of which is between 0 and 10 inclusive, or n is 2, R' then being an alkyl radical of 2 to 8 carbon atoms and m=p=o; and R is an alkyl radical of 1 to 4 carbon atoms.The initiators are prepared by reacting compounds of the formula; ##STR2## with an alkyl-lithium RLi in a non-polar solvent in the absence of any polar solvent or complexing agent.The initiators are used to prepare polydienes of high stereoregularity by reacting with a diene, and the polydiene is used to prepare a three-block or star copolymer by reacting with an anionically polymerizable monomer.

Abstract: A process for polymerizing ethylene under high pressure and temperature in at least one reactor having at least one reaction zone. A catalyst system is used that comprises (a) an activator selected from trialkylaluminums, hologenodialkylaluminums, and alkylsiloxalanes, (b) a halogen compound of a transition metal of groups IV to VI A, and (c) a complexing agent that is injected into the reactor in such a manner that its concentration in the reactor may be adjusted independently from the concentration of (b). The complexing agent may be selected from silicone oils and from compounds having the formula X(OR).sub.n, wherein X is hydrogen or a metal, n is the valence of X, and R is an alkyl radical of up to 20 carbon atoms.

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: A method of mulching comprising mulching plants or soil with antistatic films of a synthetic polymer obtained by the method consisting essentially of continuously printing over at least part of the surface of at least one side of the film of synthetic polymer with aluminum powder by suspending in solvent a composition consisting essentially of aluminum powder and a polyamide resin, setting the suspension down onto the film, and permitting the solvent to evaporate. The films obtained have a surface resistivity of less than 10.sup.10 ohms/cm. The mulching of plants with these films prevents virus degeneration of the plants by virus-carrying aphides, and the mulching of the soil limits the increase of soil temperature in warm environments.

Abstract: A process and apparatus for widening the molecular distribution of ethylene polymers produced at high pressure and at high temperature by polymerizing ethylene at a pressure between 600 and 3,000 bars and at a temperature between 160.degree. C. and 320.degree. C., in two reactors operating in parallel. In the first reactor, the reaction takes place in the presence of less than 0.1% of hydrogen for the purpose of producing a polymer of high molecular weight. In the second reactor, the reaction takes place in the presence of 0.2 to 5% of hydrogen for the purpose of fabricating a polymer of low molecular weight. The effluents from these two reactors are expanded and then moved to a set of two separators interconnected so as to efficiently mix the polymers produced in the two reactors by recycling the least possible amount of hydrogen into the supply circuit of the first reactor in such manner that the proportion of hydrogen in the first reactor remains less than 0.1% in moles.

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 vandium, 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: New organo-lithium initiators, their synthesis, and their use. The initiators have the formula: ##STR1## in which R" is either a hydrogen atom or a methyl radical; either n is 1, in which case R' = H and m and p are integers, the sum of which is between 0 and 10 inclusive, or n is 2, R' then being an alkyl radical of 2 to 8 carbon atoms and m =p =0; and R is an alkyl radical of 1 to 4 carbon atoms.The initiators are prepared by reacting compounds of the formula: ##STR2## with an alkyl-lithium RLi in a non-polar solvent in the absence of any polar solvent or complexing agent.The initiators are used to prepare polydienes of high stereoregularity by reacting with a diene, and the polydiene is used to prepare a three-block or star copolymer by reacting with an anionically polymerizable monomer.

Abstract: A method for producing an antistatic film of a synthetic polymer consisting essentially of continuously printing over at least part of the surface of at least one side of the film with aluminum powder by suspending in solvent a composition consisting essentially of aluminum powder and a polyamide resin, setting the suspension down onto the film, and permitting the solvent to evaporate The films obtained have a surface resistivity of less than 10.sup.10 ohms/cm and are useful, in addition to conventional uses such as packaging, for preventing virus degeneration of plants by virus-carrying aphides by mulching the plants with the films, limiting the increase in soil temperature in warm environments by mulching the soil with the films, and reducing the calorific energy necessary to heat greenhouses with the films.

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 cross-section S.sub.1 through which 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 cross-section S.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/S.sub.1 is between 0.20 and 1.35 t/hr.mm2 and the ratio (q+Q/S.sub.3 is between 0.1 and 0.3 t/hr.mm2.

Abstract: A high-temperature, high-pressure process for polymerizing ethylene in a reactor system having at least two reaction zones with a catalytic system including an activator (a), a compound (b), and a compound (c). Compounds (b) and (c) are injected into different reaction zones. Activator (a) is selected from hydrides and organometallic compounds of a metal of groups I to III of the Periodic Table. Compound (b) is represented by the formula(TiCl.sub.a) (MgCl.sub.2).sub.y (AlCl.sub.3).sub.z (RMgCl).sub.bin which2.ltoreq.a.ltoreq.3, y.gtoreq.2, O.ltoreq.z .ltoreq.1/3, O.ltoreq.b.ltoreq.1and R is an aliphatic or aromatic hydrocarbon radical.Compound (c) is represented by the formulaTiCl.sub.3 (AlCl.sub.3).sub.w (E, TiCl.sub.4).sub.xin which O.ltoreq.w.ltoreq.1/3, O.ltoreq.x.ltoreq.0, 03 and E is a diisoamyl- or di-n-butylether.The amounts of (a), (b), and (c) are such that the ratio Al/Ti is between 1 and 10 in each reaction zone.