Abstract: A solid component of catalyst for the (co)polymerization of ethylene and &agr;-olefins contains magnesium-carboxylate bonds and transition metal-carboxylate and can be represented by the formula: M1Mg(0.3-20)X(2-60)Al(0-6)(R—COO)(0.1-3)  (I) wherein: M is at least one metal selected from titanium, vanadium, zirconium and hafnium, X is a halogen excluding iodine, and R is an aliphatic, cycloaliphatic or aromatic hydrocarbon radical, containing at least 4 carbon atoms. A description follows of the preparation of a solid component of catalyst (I) and its use in procedures for the (co)polymerization of ethylene and &agr;-olefins.

Abstract: A process for preparing formed articles made of polyurethane foams, which comprises reacting at least a polyisocyanate with at least a compound containing end activated hydrogens in the presence of an expanding medium, selected from at least a hydrofluoroalkane and/or perfluoroalkane, and of a product, containing at least a structural unit of the aminic type, chemically bound or present in free form in one of the two polyurethane reagents, said expanding medium being dissolved in said one of the two polyurethane reagents.

Abstract: A solid component of catalyst for the (co)polymerization of ethylene is composed of a silica carrier and a catalytically active part including titanium, magnesium, chlorine and alkoxylic groups and is obtained: by suspending an activated silica in a solution of magnesium chloride and titanium tetraalcoholate in a liquid aliphatic acid ester; eliminating the aliphatic acid ester from the resulting suspension to recover a solid; and making this solid react with an aluminium alkyl chloride. It is preferable to add also some measured quantities of a silicon halide to the solution in aliphatic acid ester.

Abstract: Conductive polymers with ionic conductance including a non-aqueous complex of a polyester having the formula ##STR1## wherein: R.sub.1 and R.sub.2 are a C.sub.1 -C.sub.6 alkylene radical; G is a bivalent group deriving from H --(--O--R.sub.3 --).sub.p --O--R.sub.3 --OH with p=0 or 1-10 and R.sub.3 a C.sub.1 -C.sub.6 alkylene radical; X is CH.sub.2, S or O, and n=5-100; with an ionic compound. The polyesters having formula (I) wherein: X=S; R.sub.1, R.sub.2 and R.sub.3 are each --CH.sub.2 --CH.sub.2 --; p=1-10 and n=5-100, are also new.

Abstract: A solid component of catalyst highly active in the (co)polymerization of ethylene containing titanium, magnesium, aluminum, chlorine and alkoxy groups, and obtained by means of a procedure wherein:(i) a solid, granular support of magnesium chloride, obtained by spray-drying an alcohol solution of magnesium chloride, is suspended in a liquid hydrocarbon solvent and an aliphatic alcohol and a titanium tetraalkoxide are added to the suspension thus obtained,(ii) the suspension of step (i) is heated until a homogeneous solution is obtained and the solution is cooled to precipitate a granular solid in a relative suspension,(iii) the granular solid obtained in step (ii), in the relative suspension, is put in contact and reacted with an aluminum alkyl halide, and(iv) the solid component catalyst is recovered from the reaction products of step (iii).

Abstract: A description follows of bitumens modified with recycled and/or virgin polymers, such as polyethylene (PE) and ethylene-vinylacetate copolymer which, having special structural and morphological characteristics, give an improved performance with respect to bitumen as such or modified with traditional polymers; the mixtures thus obtained are used for street paving or different kinds of waterproofing.

Abstract: A solid component of catalyst, active in the polymerization of propylene and other .alpha.-olefins in stereoregular polymers, is obtained:(i) by treating a non-activated silica support in particles with a tin tetrahalide, to at least partially block the hydroxylic groups of the silica and to obtain a blocked silica;(ii) by impregnating the blocked silica with magnesium dialkyl or magnesium alkyl halide to make the magnesium compound react with the tin compound and with possible residual hydroxylic groups of the silica and to obtain a support;(iii) by halogenating the support by contact with a halogenating agent selected from the halides of tin, antimonium or silicon to obtain a halogenated support;(iv) by titanating the halogenated support with an excess of a titanium tetrahalide to obtain a titanated support;(v) by putting the titanated support in contact with a Lewis base, to obtain a solid component of catalyst.

Abstract: A catalyst for the polymerization of olefins, containing magnesium, chlorine, aluminium and at least one transition metal, in a dispersed or emulsified form within an inert diluent, is obtained by:contacting, in an inert diluent, a magnesium dialkyl and aluminium trichloride, in a molar ratio equal or almost equal to 2/1, at a temperature lower than 105.degree. C. to obtain a catalyst precursor in a suspended form, or at a temperature higher than 105.degree. C. to form a catalyst precursor in the form of a colloidal emulsion, in the diluent used; andcontacting said suspended or emulsified precursor with at least one compound of a transition metal to form a catalyst in the form of a suspension or emulsion respectively.

Abstract: A supported solid component of catalyst, for the stereospecific polymerization of propylene and other .alpha.-olefins, is obtained by making a non-activated silica interact in succession with: (i) a magnesium dialkyl or halide of magnesium alkyl; (ii) a halogenating agent selected from silicon, tin and antimony halides; (iii) a titanium tetrahalide; and (iv) a Lewis base. A catalyst for the stereospecific polymerization of propylene and other .alpha.-olefins is composed of: (A) the solid component of catalyst; (B) an aluminium trialkyl or aluminium alkyl halide; and (C) an electron donor compound, capable of forming a complex compound with component (B).

Abstract: Thermoplastic compositions having improved mechanical characteristics and particularly an improved impact resistance, especially when measured on test pieces having high thickness, comprising:(A) an impact resistant vinyl aromatic graft copolymer containing an amount comprised between 0.1 and 2% by weight of an ethylenically unsaturated compound having a carboxylic group or one of its derivatives in the molecule; and(B) a polyamide resin.

Abstract: Molding compositions having high rates of crystallization and suitable for being molded at a temperature of the mold not higher than 100.degree. C. to produce molded articles having an optimal combination of mechanical, physical, thermal properties and of surface appearance, comprising: a linear saturated polyester (A); a salt of a mono- or poly-carboxylic acid (B); an ionomer copolymer containing side carboxylic groups at least partially salified (C), and a solid inert inorganic substance (D) having a particle size not higher than 5 micrometers. Said compositions may be reinforced by reinforcing materials, preferably by glass fibers.

Abstract: A solid component of catalyst for the (co)polymerization of ethylene is composed of a silica support and of a catalytically active part containing titanium, magnesium, chlorine and alkoxy groups, and is obtained by:(i) activating a silica support by contact with a solution of magnesium dialkyl, or magnesium alkyl chloride, in a liquid, aliphatic hydrocarbon solvent;(ii) impregnating the activated silica with a solution, in a liquid aliphatic or aromatic ester, of titanium tetrachloride and tetra-alkoxide in equimolecular or almost equimolecular quantities, and magnesium chloride; and(iii) treating the solid obtained in step (ii) with a proportioned quantity of aluminium alkyl sesquichloride.

Abstract: Solid component of catalyst for the (co)polymerization of ethylene, including magnesium, halogen and titanium, obtained by:(i) dissolution, in an inert organic solvent, of a magnesium dialkyl, or a magnesium alkyl halide, a tin halide (IV) and possibly also an alkyl halide and their contact until a granular solid precipitates from the solution;(ii) contact of said granular solid and its interaction with a titanium halide, alkoxide or halo-alkoxide, to form a solid component of catalyst.

Abstract: Thermoplastic compositions with improved mechanical characteristics, including:a) a graft impact-resistant vinylaromatic copolymer containing a quantity of between 0.1 and 2% by weight of an ethylenically unsaturated compound having a carboxylic group or one of its derivatives in the molecule;b) a polyamide resin andc) a polyolefin.

Abstract: A thermoplastic composition based on a polyolefin and a vinyl aromatic polymer, having an improved combination of physical, mechanical and thermal properties, comprising:from 40 to 80% by weight of a vinyl aromatic polymer (A) containing, as an elastomeric component, from 0.5 to 5% by weight of a vinyl aromatic monomer - conjugated diene linear block polymer and from 5 to 15% of a diene rubber, from 5 to 50% by weight of a polyolefin (B) and from 10 to 50% by weight of an olefinic elastomer (C) containing, grafted thereon, a vinyl aromatic polymer, wherein the molar ratio between the vinyl aromatic polymer and the olefinic elastomer in the grafted phrase is greater than 0.8, the sum of components (A), (B) and (C) being equal to 100%.

Abstract: A solid component of catalyst for the (co)polymerization of ethylene, including magnesium, halogen and titanium, is prepared:(i) by dissolving a magnesium dialkyl, a silicon halide and at times also an alkyl halide, in an inert organic solvent and maintaining contact until a granular solid precipitates;(ii) putting this granular solid in contact and making it react with a titanium halide, alkoxide or halogen-alkoxide, to produce a solid component of catalyst; and(iii) activating this solid component of catalyst by contact with aluminium alkyl halide, if a titanium alkoxide or halogen-alkoxide has been used in phase (ii).

Abstract: A process for the preparation of a solid component of a catalyst active in the (co)polymerization of ethylene and able to form (co)polymers of ethylene having from middle to wide distribution of molecular weight and monomodal distribution of molecular weights, in processes operating in a single step, in suspension or in the gaseous phase. Said solid component of a catalyst contains magnesium, chlorine, silicon, titanium and at least another transition metal on a solid, granular and porous carrier and is obtained by treating the carrier, in succession, with: a compound of a metal selected from hafnium, zirconium or vanadium; a magnesium dialkyl or magnesium alkyl halide; a silicon chloride; and a titanium compound.

Abstract: Flame-retardant thermoplastic composition including a styrene polymer containing thoroughly incorporated therein an effective quantity of a synergetic mixture composed of a chlorinated hydrocarbon compound containing at least 40% by weight of combined chlorine, an inorganic compound containing oxygen of a metal belonging to group III or IV of the periodic table, and polytetrafluoroethylene having a particle size which is less than 20 microns.

Abstract: Moulding thermoplastic compositions, endowed with improved mould release characteristics, comprising:A) an impact resistant vinyl aromatic copolymer consisting of an ethylenically unsaturated nitrile, a vinyl aromatic monomer and a rubber;B) an engineering polymer; andC) an effective amount of a release agent constituted by a synergistic mixture of an ester of a C.sub.16 -C.sub.18 acid with glycerol and an ester of a saturated aliphatic C.sub.10 -C.sub.20 acid with a C.sub.4 -C.sub.6 aliphatic alcohol.The physical-mechanical properties of the compositions at high moulding temperatures can be improved by addition of an effective amount of a bis(alkyl-phenyl)pentaerythritol diphosphite.The compositions can, furthermore, contain in addition a grafted polymer consisting of an elastomeric core having a Tg lower than 10.degree. C. and containing vinyl monomer chains grafted thereon.

Abstract: The thermal and hydrolytic stabilities of the elastomeric thermoplastic copolyether-esters are remarkably improved by the addition of a synergistic mixture consisting of an tri (hydroxybenzyl) benzene and of a bis (alkyl-phenyl) pentaerythritol diphosphite.The copolyether-esters thus compounded find use in the extrusion, blow and injection molding technologies.