Atactic polypropylene
AssigneeMontell Technology Company BV
InventorsLuigi Resconi, Enrico Albizzati
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Abstract
Amorphous propylene polymers are disclosed having the following characteristics: (a) intrinsic viscosity [.eta.]>1 d1/g; (b) %(r)-%(m)>0, wherein % (r) is the % of syndiotactic diads and %(m) is the % of isotactic diads; (c) less than 2% of the CH.sub.2 groups contained in sequences (CH.sub.2).sub.n, with n.gtoreq.2; (d) Bernoullianity index (B)=1.+-.0.2. These propylene polymers, which are in addition endowed with a narrow molecular weight distribution, can be obtained directly from the polymerization reaction of propylene as sole product and, therefore, do not require to be separated.
Claims5
A process for the preparation of an amorphous polypropylene, comprising the polymerization reaction of propylene in the presence of a catalyst comprising the product of the reaction between:
- (A) a compound of formula (I) ##STR5## wherein substituents R.sup.l, the same or different from each other, are hydrogen atoms, C.sub.1 -C.sub.20 alkyl radicals, C.sub.3 -C.sub.20 cycloalkyl radicals, C.sub.2 -C.sub.20 alkenyl radicals, C.sub.6 -C.sub.20 aryl radicals, C.sub.7 -C.sub.20 alkylaryl radicals, or C.sub.7 -C.sub.20 arylalkyl radicals, optionally two adjacent substituents R.sup.1 can form a cycle comprising from 5 to 8 carbon atoms and, furthermore, substituents R.sup.1 can contain Si or Ge atoms;
- M is Ti, Zr or Hf;
- substituents R.sup.2, the same or different from each other, are halogen atoms, --OH, --SH, R.sup.1, --OR.sup.1, --SR.sup.1, --NR.sub.2.sup.1 or --PR.sub.2.sup.1 , wherein R.sup.1 is defined as above;
- the group R.sup.3 is selected from >CR.sub.2.sup.1, >SiR.sub.2.sup.1, >GeR.sub.2.sup.1, >NR.sup.1 or >PR.sup.1, wherein R.sup.1 is defined as above and optionally, when R.sup.3 is >CR.sub.2.sup.1 , >SiR.sub.2.sup.1 or >GeR.sub.2.sup.1, both substituents R.sup.1 can form a cycle comprising from 3 to 8 atoms;
- (B) an alumoxane, or one or more compounds able to give a metallocene alkyl cation.
Dependencies are inferred from the claim text.