摘要:
A process for polymerizing one or more alpha-olefins of formula CH2═CHT wherein T is a hydrogen atom or a C1–C20 alkyl radical comprising the following steps: a) contacting in a continuous way one or more of said alpha olefins with a metallocene based catalyst system in a loop reactor, wherein: (i) the reaction is carried out in a liquid medium; (ii) the average residence time of the metallocene-based catalyst system is not more than 30 minutes; (iii) the temperature of the loop ranges from 25° to 70° C.; in order to obtain a polymerization degree ranging from 60 to 500 g per gram of catalyst system; b) feeding in continuous the prepolymerized metallocene-based catalyst system obtained in step a) into a polymerization reactor C) polymerizing one or more alpha-olefins, the same or different from the alpha olefins used in step a), in the presence of said prepolymerized metallocene-based catalyst system.
摘要:
The present invention relates to pulverulent solids obtainable by reaction of a metal alkyl compound of a divalent or higher-valent metal and a finely divided support which on its surface bears functional groups which can form a chemical bond between the metal atom of the metal alkyl compound and the surface of the support, wherein the particles of the finely divided support have particle diameters of less than 1000 nm and less than 5% by weight of the metal alkyl compound is extractable in a single extraction of the pulverulent solid with 20 ml of heptane per gram of solid at 50° C. In addition, the invention relates to a process for preparing the pulverulent solids, a catalyst composition for the polymerization of olefins which comprises the pulverulent solids and polymerization processes using the catalyst composition.
摘要:
The present invention relates to pulverulent solids obtainable by reaction of a metal alkyl compound of a divalent or higher-valent metal and a finely divided support which on its surface bears functional groups which can form a chemical bond between the metal atom of the metal alkyl compound and the surface of the support, wherein the particles of the finely divided support have particle diameters of less than 1000 nm and less than 5% by weight of the metal alkyl compound is extractable in a single extraction of the pulverulent solid with 20 ml of heptane per gram of solid at 50° C. In addition, the invention relates to a process for preparing the pulverulent solids, a catalyst composition for the polymerization of olefins which comprises the pulverulent solids and polymerization processes using the catalyst composition.
摘要:
A 1-butene/propylene copolymer composition having a content of propylene derived units from 4 to 10% by weight, wherein at least 50% of the polymer is present in the thermodynamically stable, trigonal form I after 100 hours at room temperature, said composition comprising: a) from 5% by weight to 95% by weight of an atactic 1-butene propylene copolymer having the following features: i) distribution of molecular weight Mw/Mn equal to or lower than 4; ii) no enthalpy of fusion detectable at a differential scanning calorimeter (DSC); and iii) infrared crystallinity lower than 0.5%; b) from 5% by weight to 95% by weight of an isotactic 1-butene propylene copolymer having the following features: i) isotactic pentads (mmmm) measured by 13C-NMR, higher than 80%; ii) melting point (Tm(II)) higher than 70° C.; and iii) distribution of molecular weight Mw/Mn equal to or lower than 4.
摘要:
Method for continuously removing the unreacted butene-1, and optionally other volatile components, from a polymeric solution obtained by liquid phase (co)polymerization of butene-1, the method comprising the steps of: subjecting the polymeric solution to heating and mixing conditions such that a mixture is formed consisting substantially of: (1) a polybutene melt containing entrapped butene-1 and (2) supercritical gaseous butene-1; subjecting the above mixture to a sequence of devolatilization steps operating at decreasing pressures.
摘要:
A 1-butene/propylene copolymer composition having a content of propylene derived units from 1 to 4% by weight, wherein at least 50% of the crystalline polymer is present in the thermodynamically stable, trigonal Form I (detected by DSC analysis) after 100 hours of the first melting at room temperature comprising: b) from 5% by weight to 95% by weight of an atactic 1-butene propylene copolymer having the following features: i) distribution of molecular weight Mw/Mn equal to or lower than 4; ii) no enthalpy of fusion detectable at a differential scanning calorimeter (DSC); and iii) infrared crystallinity lower than 0.5%; b) from 5% by weight to 95% by weight of an isotactic 1-butene propylene copolymer having the following features: i) isotactic pentads (mmmm) measured by 13C-NMR, higher than 80%; ii) melting point (Tm(II)) higher than 70° C.; and iii) distribution of molecular weight Mw/Mn equal to or lower than 4.
摘要:
Butene-1 (co)polymers characterized by the following properties: content of butene-1 units in the form of isotactic pentads (mmmm) from 25 to 55%; intrinsic viscosity [η] measured in tetraline at 135° C. from 1 to 3 dL/g; content of xylene insoluble fraction at 0° C. from 3 to 60%; and a ratio ES2/ES1≧1, where ES1 is the boiling diethyl ether soluble fraction determined on the polymer as such and ES2 is the boiling diethyl ether soluble fraction determined after milling the polymer. The butene-1 (co)polymers show a good balance between processability and elastomeric behavior.
摘要:
Method for continuously removing the unreacted butene-1, and optionally other volatile components, from a polymeric solution obtained by liquid phase (co)polymerization of butene-1, the method comprising the steps of: subjecting the polymeric solution to heating and mixing conditions such that a mixture is formed consisting substantially of: (1) a polybutene melt containing entrapped butene-1 and (2) supercritical gaseous butene-1; subjecting the above mixture to a sequence of devolatilization steps operating at decreasing pressures.
摘要:
A process for producing a 1-butene polymer comprising the step of polymerizing 1-butene in the presence of a catalyst system obtainable by contacting: b) at least a metallocene compound of formula (Ia) in the meso or meso-like form: wherein M is an atom of a transition metal p is an integer from 0 to 3, X, same or different, is a hydrogen atom, a halogen atom, or a hydrocarbon group. L is a divalent C1-C40 hydrocarbon radical R1 and R2, equal to or different from each other, are C1-C40 hydrocarbon radicals; T, equal to or different from each other, is a moiety of formula (IIa), (IIb) or (IIc): wherein R3 and R5 are a C1-C40 hydrocarbon radical; R4 and R6, equal to or different from each other, are hydrogen atoms or C1-C40 hydrocarbon radicals and R7 and R8, equal to or different from each other, are hydrogen atoms or C1-C40 hydrocarbon radicals b) at least a metallocene compound of formula (Ib) in the racemic (rac) or racemic-like form c) an alumoxane or a compound capable of forming an alkyl metallocene cation.
摘要:
A 1-butene polymer optionally containing from 0 to 30% by mol of derived units of ethylene, propylene or alpha-olefin of formula CH2═CHZ, wherein Z is a C3-C20 linear or branched alkyl radical, having the following features: a) distribution of molecular weight (Mw/Mn) lower than 4; b) Melt flow rate (MFR) measured according to ISO 1133 (190° C., 2.16 kg); c) Intrinsic viscosity (IV) measured in tetrahydronaftalene (THN) at 135° C. lower than 0.8 dl/g; d) melting point higher than 100° C.; e) isotactic pentads (mmmm) measured with 13C-NMR operating at 100.61 MHz higher than 90%; f) 4,1 insertions not detectable at a C13-NMR operating at 100.61 MHz; and g) a yellowness index lower than 0.