Abstract:
Activator solid support for metallocenes as catalysts in the polymerization of olefins, characterized in that it consists of a group of support particles for a solid catalytic component, which are formed from at least one porous mineral oxide, the said particles having been modified in order to carry, on the surface, aluminium and/or magnesium Lewis-acid sites of formula: or —Mg—F, the groups coming from a functionalization agent having reacted with —OH radicals carried by the base particles of the support, the functionalization reaction having been followed by a fluorination reaction. The catalytic system according to the invention comprises (a) a metallocene catalyst, which has, if required, been subjected to a prealkylation treatment; (b) a cocatalyst; and (c) an activator solid support for metallocene, as defined above, it being possible for the cocatalyst (b) to be absent if the metallocene catalyst (a) has been prealkylated.
Abstract:
The invention relates to a process for the manufacture of a solid catalytic component for the polymerization or copolymerization of olefins, resulting in a polymer or copolymer with broadened molecular mass distribution. The process includes a first stage including bringing into contact a) a solid support including at its surface at least 5 hydroxyl groups per square nanometre (OH/nm2) and b) an organic magnesium derivative, and optionally, preferably, c) an aluminoxane, to obtain a first solid, and then a second stage including bringing the first solid and a chlorinating agent into contact to obtain a second solid and then, in a later stage, impregnation of the second solid with a transition metal derivative.
Abstract:
Activator solid support for metallocenes as catalysts in the polymerization of olefins, characterized in that it consists of a group of support particles for a solid catalytic component, which are formed from at least one porous mineral oxide, the said particles having been modified in order to carry, on the surface, aluminium and/or magnesium Lewis-acid sites of formula: functionalization agent having reacted with —OH radicals carried by the base particles of the support, the functionalization reaction having been followed by a fluorination reaction. Also disclosed is a catalytic system including a metallocene catalyst, which has optionally been subjected to a prealkylation treatment; a cocatalyst; and an activator solid support for metallocene, as defined above.
Abstract:
A catalyst support in the form of solid particles consisting essentially of a complex of MgCl.sub.2 and alcohol of the formula MgCl.sub.2, x(n-BuOH) in which 0.1.ltoreq.x.ltoreq.2, and which has a specific surface of 1 to 20 m.sup.2 /g and a particle porosity of 1 to 2 cm.sup.3 /g, and the process of making such support, and catalytic components comprising such support, a transition metal, and optionally, an electron donor.
Abstract:
Polymer compositions comprising poly(benzhydrolimide) chains ending with ethylenic unsaturated groups complying with the general formula: ##STR1## wherein Ar is a divalent aromatic radical and R a hydrogen atom or a monovalent hydrocarbon radical. They can be prepared by reacting, under imidation condition, at least one primary diamine with at least one benzydrol 3,3', 4,4'-tetracarboxylic acid, a bis (ortho-acid-ester) or a tetraester of such acid and with an anhydride, an acid-ester or a diester of dicarboxylic cycloaliphatic acid with ethylenic unsaturation. These compositions may be converted to cross-linked polymides by thermal polyemrization. They can be used in particular for manufacturing composite materials, adhesives, molded articles and protective coatings withstanding high temperatures.
Abstract:
Aromatic polyimide compositions, precursors of copolyphthalocyanine-imides,heir manufacturing process and the resultant copolyphthalocyanine-imides, are described.These compositions may result for the reaction of 80.degree.-300.degree. C. of an aromatic tetra acid, diester-diacid, tetraester or dianhydride compound of formula: ##STR1## with an aromatic amino-dinitrile ##STR2## and optionally an aromatic diamine NH.sub.2 --Ar--NH.sub.2. A subsequent heating at 200.degree.-300.degree. C. provides, by cross-linking, copolyphthalocyanine-imides, which are hardened resins, stable at 250.degree.-300.degree. C. in continuous use.
Abstract:
The present invention relates to a catalytic component for the polymerization of olefins combining a number of catalytic components for the polymerization of olefins and to a process for preparing it. The catalytic component according to the invention is obtained by impregnation of a prepolymer with a solution of a catalytic component for the polymerization of olefins. The invention brings about control of the combination of different catalytic components and provides for improvement in the control of the quality of the polymers manufactured by virtue of the catalytic action of the combined catalytic components. Another advantage of the invention is to be able to control the morphology and the particle size distribution of the polymers by choosing the morphology of a single catalytic component. The prepolymer and the polymer obtained from the catalytic component according to the invention are also subjects of the present invention.
Abstract:
The invention relates to novel bridged biphosphole ligands according to the general formula: where R2, R3, R4 are chosen from hydrogen, alkyl, aryl or silyl, R1 is chosen from hydrogen, alkyl, aryl or halogen, R1 possibly being replaced with a direct bond between the two phosphorus atoms and T is a divalent group. The invention also relates to metallocenes obtained from these ligands. These metallocenes are useful as catalytic components for the polymerization of olefins.
Abstract:
The invention concerns a method for preparing block copolymers comprising steps which consist in: polymerising a first monomer using an organolanthanide catalyst wherein said catalyst in the form of a hydride complex of a trivalent metal from the group of rare earths; then in polymerising at least a second monomer. The invention also concerns block copolymers whereof the blocks are polyolefins.
Abstract:
The present invention relates to a catalytic composition for the polymerization of olefins combining a number of catalytic components for the polymerization of olefins and to a process for preparing it. The catalytic component according to the invention is obtained by impregnation of a prepolymer with a solution of a catalytic component for the polymerization of olefins. The invention brings about control of the combination of different catalytic components and provides for improvement in the control of the quality of the polymers manufactured by virtue of the catalytic action of the combined catalytic components.