RU2002115632A - CATALYST AND METHOD OF POLYMERIZATION - Google Patents

Claims (13)

1. A method of producing a copolymer of ethylene and 1-hexene, where the specified copolymer has a swelling by weight of less than about 380% and a swelling of the extrudable stream of less than about 42%, ESCR (condition A) over about 400 hours, the beginning of the destruction of the extrusion stream, at least about 2000 s ^-1 , and the result when tested for release in 1 min, at least about 1200 g / min, the content of substances soluble in xylene, less than 0.7% and less than 2 wt.% substances with a molecular weight of less than 1000 including contacting under conditions of suspension polymerization at times isobutane at a temperature of from about 220 to 230 ° F a) ethylene monomer, b) 1-hexene, c) a catalytic system containing chromium supported on a silicon dioxide-titanium oxide carrier, which contains from about 0.5 to about 3 wt.% titanium relative to the weight of the carrier, said catalyst system having a surface area in the range of about 100 to about 500 m ² / g, a pore volume in the range of about 0.6 to about 1.4 ml / g, and said catalyst system is activated at a temperature in the range from about 538 ° C to p imerno 650 ° C, d) from about 0.1 to about 2.0 mg / kg with respect to the diluent in the reactor, trialkylboron, and e) recovering copolymer. 2. The method according to claim 1, where the temperature in the reactor is in the range from about 210 to about 220 ° F. 3. The method according to claim 1, where the titanium oxide in a silicon dioxide silicon oxide titanium carrier is coprecipitated with silicon dioxide. 4. The method according to claim 1, where the catalyst system is subjected to aging twice, the first aging taking place at a substantially neutral pH, and the second aging taking place at an alkaline pH. 5. The method according to claim 1, where the trakylboron cocatalyst is present in the reactor in an amount in the range from 0.3 to 1.3 mg / kg diluent. 6. The method according to claim 1, where the catalytic system has pores with an average diameter in the range from about 50 to about

. 7. The method according to claim 1, where the catalytic system has a surface area of more than 500 m ² / g 8. The method according to claim 1, where the catalytic system has a pore volume of more than 2.5 ml / g 9. The method according to claim 1, where the catalytic system has a pore volume of more than 2.5 ml / g 10. The method according to claim 1, where the catalyst contains from about 0.8 to about 1.8 wt.% Chromium. 11. A copolymer of ethylene and 1-hexene obtained by the method of claim 1. 12. A composition containing a copolymer of ethylene and 1-hexene, where the specified copolymer has a melt index at high load (HLMI) in an integral of from about 5 to about 25 g / 10 min, a density in the range of about 0.95-0.96 g / cm ³ , shear sensitivity (HLMI / MI) in the range of about 140 to about 230, mass swell less than about 350% and extrudable swell in the range of about 30% to about 40%, ESCR (condition A) over about 400 h, M _w / M _n from about 15 to about 26, the beginning of melt fracture of greater than about 2200 sec ^-1 and RESULT m when tested in release for 1 min over about 1300 g / min, the content of components soluble in xylene of less than 0.65% and less than 2.0 wt.% of the substance with a molecular weight less than 1,000. 13. A catalytic composition suitable for the copolymerization of ethylene and at least one mono-1-olefin with 3-8 carbon atoms, containing chromium supported on a silicon dioxide-titanium oxide carrier, which contains from about 0.5 to about 3 wt.% titanium relative to the mass of the carrier, the catalyst system has a surface area in the range of from about 100 to about 500 m ² / g, a pore volume in the range of from about 0.6 to about 1.4 ml / g, and said catalyst system is activated at temperature in the range from about 538 to pr approximately 650 ° C.