US 2001/0012874 A1 · PROPYLENE POLYMERS

Abstract

Propylene polymers containing a matrix of a propylene homopolymer and a copolymer of propylene and other alkenes, wherein, during the separation of the propylene polymers according to tacticity and comonomer distribution of the polymer chains, by first dissolving the propylene polymers in boiling xylene, then cooling the solution at a cooling rate of 10° C./h to 25° C. and thereafter, increasing the temperature, separating the propylene polymers into fractions of different solubility, either one or more of the conditions that i) more than 20% by weight of the matrix remain undissolved on further heating to 112° C. or ii) more than 8% by weight of the matrix remain undissolved on further heating to 117° C. or iii) more than 1% by weight of the matrix remain undissolved on further heating to 122° C. are fulfilled by the matrix which remains undissolved on heating the cooled propylene polymer solution to 80° C., a process for the preparation of the propylene polymers, their use for the production of films, fibers or moldings and the films, fibers or moldings comprising these propylene polymers, are described.

Claims14

Dependent claims

A propylene polymer containing a matrix of a propylene homopolymer and a copolymer of propylene and other alkenes, wherein, during the separation of the propylene polymers according to tacticity and comonomer distribution of the polymer chains, by first dissolving the propylene polymers in boiling xylene, then cooling the solution at a cooling rate of 10° C./h to 25° C. and thereafter, increasing the temperature, separating the propylene polymers into fractions of different solubility, either one or more of the conditions that

i) more than 20% by weight of the matrix remain undissolved on further heating to 112° C. or
ii) more than 8% by weight of the matrix remain undissolved on further heating to 117° C. or
iii) more than 1% by weight of the matrix remain undissolved on further heating to 122° C.
are fulfilled by the matrix which remains undissolved on heating the cooled propylene polymer solution to 80° C.

1 more element

A process for the preparation of propylene polymers, in which propylene is polymerized in a first polymerization stage at from 50 to 120° C. and from 15 to 40 bar and then a copolymer of propylene and other alk-1-enes of up to 10 carbon atoms is polymerized thereon in a second polymerization stage at from 30 to 100° C. and from 5 to 40 bar and the polymerization is carried out in the presence of a Ziegler-Natta catalyst system containing, as active components,

a) a titanium-containing solid component which is obtained by reacting a titanium halide with a chlorine-free compound of magnesium, an inorganic oxide as carrier, a C1-C8-alkanol and an electron donor compound by a procedure in which first,
in a first stage, a solution of the chlorine-free compound of magnesium in an inert solvent is added to the inorganic oxide as carrier, this mixture is allowed to react for from 0.5 to 5 hours at from 10 to 120° C. and is then reacted, at from −20 to 80° C. with continuous mixing, with a C1-C8-alkanol in at least a 1.3-fold molar excess, based on the compound of magnesium, to give a chlorine-free intermediate, the titanium halide and the electron donor compound are then added to said intermediate, the resulting mixture is allowed to react for at least 10 minutes at from 10 to 150° C. and the solid substance thus obtained is then filtered off and washed, and,
in a second stage, the solid obtained from the first stage is extracted in an inert solvent which contains at least 5% by weight of titanium tetrachloride and is washed with a liquid alkane,
and, as cocatalysts,
b) an aluminum compound and
c) a further electron donor compound,
wherein, in the first polymerization stage, the molar ratio of the aluminum compound b) to the further electron donor compound c) is adjusted to a ratio of from 1.5:1 to 9:1.

4 more elements

Dependencies are inferred from the claim text.

Propylene polymers

Life of this patent

Propylene polymers

Life of this patent

Abstract

Claims14