Preparation of ultra high molecular weight ethylene copolymer
The invention relates to a process for the preparation of a particulate ultra high molecular weight polyethylene (pUHMWPE copolymer, comprising the steps of preparing a magnesium containing carrier, loading the carrier with a organometallic compound forming a supported catalyst and contacting the supported catalyst with ethylene and at least one olefinic co-monomer under polymerization conditions, wherein the organometallic compound is of the formula R 3 3 P═N—TiCpX n .
1. A particulate ultra high molecular weight polyethylene (pUHMWPE) having:
an intrinsic viscosity (IV) of at least 4 dl/g,
a co-monomer content of at least 0.05 SCB/1000TC,
a co-monomer partition factor (C pf ) of at least 0.8,
a median particle size D50 of between 50 and 500 μm, and
a total ash content of less than 1000 ppm.
2. The pUHMWPE according to claim 1 , wherein the pUHMWPE has a molecular weight distribution, Mw/Mn, of less than 4.0.
3. The pUHMWPE according to claim 1 , wherein the co-monomer is selected from the group consisting of an alpha-olefin with at least 3carbon atoms, a cyclic olefin having 5 to 20 carbon atoms and a linear, branched or cyclic diene having 4 to 20 carbon atoms.
4. The pUHMWPE according to claim 1 , wherein the UHMWPE has a residual Si-content of less than 100 ppm.
5. The pUHMWPE according to claim 1 , wherein the UHMWPE has an apparent bulk density of at least 300 kg/m 3 .
6. A process for manufacturing a molded UHMWPE article which comprises molding the pUHMWPE of claim 1 to form the molded UHMWPE article therefrom.
7. The process according to claim 6 wherein the molded article is a fiber, tape or film.
8. A product comprising the molded article produced according to the process of claim 6 .
9. The product according to claim 8 , wherein the product comprising the molded article is selected from the group consisting of ropes, cables, nets, fabrics, and protective appliances.
10. The product according to claim 8 , wherein the product comprising the molded article is a ballistic resistant product.