摘要:
A process for preparing 1,2-diimine compounds of the formula I where R1 and R2 are, independently of one another, alkyl, aryl or metallocenyl radicals, and R3, R4 are, independently of one another, H, alkyl or aryl radicals or R3 and R4 are joined so as to form, with inclusion of the two imine carbon atoms, a 5- to 8-membered ring which may be saturated or unsaturated and may be unsubstituted or substituted by any hydrocarbon radicals. The process involves reacting 1,2-dicarbonyl compounds with primary amines, which have been activated with trialkylaluminum compounds prior to the reaction with the 1,2-dicarbonyl compounds. 1,2-Diimine compounds of the formula I in which R1 and R2 are, independently of one another, metallocenyl radicals can be used to prepare metal complexes which can be used as catalysts in a process for the polymerization of unsaturated compounds.
摘要:
Bisimine compounds of the formula (I) where the symbols have the following meanings: A is a nonmetal selected from among N, S, O and P, R1 is a radical of the formula NR5R6, R2 is a radical of the formula NR5R6 or NR7R8, alkyl, aryl or cycloalkyl, R5 and R6 together with the N atom form a 5-, 6- or 7-membered ring in which one or more of the —CH— or —CH2— groups may be replaced by suitable heteroatom groups and which may be saturated or unsaturated and unsubstituted or substituted or be fused with further carbacyclic or heterocarbacyclic 5- or 6-membered rings which may in turn be saturated or unsaturated and substituted or unsubstituted, and R7 and R8 are, independently of one another, alkyl, aryl or cycloalkyl radicals, and R3, R4 are, independently of one another, H or alkyl, aryl or cycloalkyl radicals, and n is 1 or 2, are used to prepare bisimidinato complexes which can be used in the polymerization of unsaturated compounds.
摘要:
Bisimine compounds of the formula (I) where the symbols are defined in the specification are used to prepare bisimidinato complexes which can be used in the polymerization of unsaturated compounds.
摘要:
Bisimine compounds of the formula (I) where the symbols have the following meanings: A is a nonmetal selected from among N, S, O and P, R1 is a radical of the formula NR5R6, R2 is a radical of the formula NR5R6 or NR7R8, alkyl, aryl or cycloalkyl, R5 and R6 together with the N atom form a 5-, 6- or 7-membered ring in which one or more of the —CH— or —CH2— groups may be replaced by suitable heteroatom groups and which may be saturated or unsaturated and unsubstituted or substituted or be fused with further carbacyclic or heterocarbacyclic 5- or 6-membered rings which may in turn be saturated or unsaturated and substituted or unsubstituted, and R7 and R8 are, independently of one another, alkyl, aryl or cycloalkyl radicals, and R3, R4 are, independently of one another, H or alkyl, aryl or cycloalkyl radicals, and n is 1 or 2, are used to prepare bisimidinato complexes which can be used in the polymerization of unsaturated compounds.
摘要:
Process for preparing ethylene homopolymers or copolymers in the presence of free-radical polymerization initiator and at least one chain transfer agent at pressures in the range of from 110 MPa to 350 MPa and temperatures in the range of from 100° C. to 350° C. in a tubular reactor with at least two reaction zones having different concentrations of the chain transfer agent, wherein the concentration of the chain transfer agent in the first reaction zone is less than 70% of the concentration of the chain transfer agent in the reaction zone with the highest concentration of the chain transfer agent, ethylene homopolymers or copolymers obtainable by such a process, the use of the ethylene homopolymers or copolymers for extrusion coating and a process for extrusion coating a substrate selected from the group consisting of paper, paperboard, polymeric film, and metal, with such ethylene homopolymers or copolymers.
摘要:
The invention relates to a process for the continuous preparation of ethylene homopolymers or copolymers in the presence of free-radical polymerization initiators and, if desired, molecular weight regulators at from 120° C. to 350° C. and pressures in the range from 100 to 4000 bar, in which the polymer is separated from unpolymerized ethylene in a high-pressure stage at a pressure of from 100 to 500 bar and at least one low-pressure stage at a pressure of from 1 to 100 bar and the ethylene separated off in the high-pressure stage is separated from remaining monomeric, oligomeric and/or polymeric constituents and recirculated to the inlet of the tube reactor in a high-pressure circuit and the ethylene separated off in the low-pressure stage is separated from remaining monomeric, oligomeric and/or polymeric constituents and recirculated to the inlet of the tube reactor in a low-pressure circuit. The initiator is used as a solution in an isoparaffinic solvent having a boiling point of not more than 160° C. and the solvent is separated from the other monomeric, oligomeric and/or polymeric constituents in the low-pressure circuit. The solvent is then, if appropriate after being admixed with fresh solvent, reused for dissolving initiator.
摘要:
A process for preparing ethylene polymers by the high-pressure method comprises dissolving one or more free-radical initiators in one or more ketones of the formula I where R1 and R2 are identical or different and are selected from among C1-C6-alkyl and C3-C12-cycloalkyl and R1 and R2 may also be covalently linked to one another to form a 4- to 13-membered ring, prior to the polymerization, compressing the solution, metering it into the polymerization reactor at one or more points and subsequently carrying out the polymerization at from 150 to 380° C. and from 500 to 4500 bar.
摘要:
A process for preparing ethylene polymers by the high-pressure method comprises dissolving one or more free-radical initiators in one or more ketones of the formula I where R1 and R2 are identical or different and are selected from among C1-C6-alkyl and C3-C12-cycloalkyl and R1 and R2 may also be covalently linked to one another to form a 4- to 13-membered ring, prior to the polymerization, compressing the solution, metering it into the polymerization reactor at one or more points and subsequently carrying out the polymerization at from 150 to 380° C. and from 500 to 4500 bar.
摘要:
Catalyst system suitable for polymerizing unsaturated monomers and comprising active constituents obtainable by reacting A) a transition metal compound with B) aluminum trifluoride, C) a cation-forming compound and, if desired, D) further components.
摘要:
The invention relates to a process for the continuous preparation of ethylene homopolymers or copolymers in the presence of free-radical polymerization initiators and, if desired, molecular weight regulators at from 120° C. to 350° C. and pressures in the range from 100 to 4000 bar, in which the polymer is separated from unpolymerized ethylene in a high-pressure stage at a pressure of from 100 to 500 bar and at least one low-pressure stage at a pressure of from 1 to 100 bar and the ethylene separated off in the high-pressure stage is separated from remaining monomeric, oligomeric and/or polymeric constituents and recirculated to the inlet of the tube reactor in a high-pressure circuit and the ethylene separated off in the low-pressure stage is separated from remaining monomeric, oligomeric and/or polymeric constituents and recirculated to the inlet of the tube reactor in a low-pressure circuit. The initiator is used as a solution in an isoparaffinic solvent having a boiling point of not more than 160° C. and the solvent is separated from the other monomeric, oligomeric and/or polymeric constituents in the low-pressure circuit. The solvent is then, if appropriate after being admixed with fresh solvent, reused for dissolving initiator.