Metallocene catalyzed polyethylene resin
The present invention relates to a metallocene-catalyzed polyethylene resin comprising at least two metallocene-catalyzed polyethylene fractions A and B, wherein the polyethylene resin comprises: at least 25% to at most 55% by weight of polyethylene fraction A based on the total weight of the polyethylene resin, wherein fraction A has a density at least 0.005 g/cm 3 higher than the density of the polyethylene resin; and a melt index MI2 of at least 25.0 g/10 min as determined according to ISO 1133, condition D, at 190° C. and under a load of 2.16 kg; and wherein the polyethylene resin has a density of at least 0.938 g/cm 3 to at most 0.954 g/cm 3 as measured according to ASTM D-1505 at 23° C.; a melt index MI2 of at least 2.5 g/10 min to at most 25.0 g/10 min as determined according to ISO 1133, condition D, at 190° C. and under a load of 2.16 kg and a molecular weight distribution M w /M n of at least 2.6 to at most 4.2, with M w being the weight-average molecular weight and M n being the number-average molecular weight. The present invention also relates to an article comprising said resin.
1. A metallocene-catalyzed polyethylene resin comprising at least two metallocene-catalyzed polyethylene fractions A and B, wherein the polyethylene resin comprises:
at least 25% to at most 42% by weight of polyethylene fraction A based on the total weight of the polyethylene resin, wherein fraction A has a melt index MI2 of at least 25.0 g/10 min as determined according to ISO 1133, condition D, at 190° C. and under a load of 2.16 kg, and a density at least 0.005 g/cm 3 higher than the density of the polyethylene resin; and
wherein the polyethylene resin has a density of at least 0.938 g/cm 3 to at most 0.949 g/cm 3 as measured according to ASTM D-1505 at 23° C.; a melt index MI2 of at least 2.5 g/10 min to at most 25.0 g/10 min as determined according to ISO 1133, condition D, at 190° C. and under a load of 2.16 kg, and a molecular weight distribution M w /M n of at least 2.6 to at most 3.5, with M w being the weight-average molecular weight and M n being the number-average molecular weight.
2. The metallocene-catalyzed polyethylene resin according to claim 1 , wherein the Temperature Rising Elution Fractionation (TREF) distribution curve of the resin comprises at least one peak appearing at a temperature of at least 97° C. to at most 105° C. and having an area under the curve of at least 5.0% to at most 25.0%; as determined using a crystallization rate of −0.5° C./min from 95° C. to 35° C., and column load volume of 1.90 ml.
3. The metallocene-catalyzed polyethylene resin according to claim 2 , wherein the Temperature Rising Elution Fractionation (TREF) distribution curve of the resin further comprises two more peaks having the following features:
peak 1 appearing at a temperature of at least 87.0° C. to at most 93.0° C. and having an area under the curve of at least 25.0% to at most 50.0%;
peak 2 appearing at a temperature of at least 94.0° C. to at most 98.0° C. and having an area under the curve of at least 35.0% to at most 60.0%.
4. The metallocene-catalyzed polyethylene resin according to claim 2 , wherein the Temperature Rising Elution Fractionation (TREF) distribution curve has an area under the curve of at most 5.0% at a temperature of 65° C. or below.
5. The metallocene-catalyzed polyethylene resin according to claim 1 , wherein the polyethylene resin has a multimodal molecular weight distribution.
6. The metallocene-catalyzed polyethylene resin according to claim 1 , wherein fraction A has a density at least 0.010 g/cm 3 higher than the density of the polyethylene resin.
7. The metallocene-catalyzed polyethylene resin according to claim 1 , wherein polyethylene fraction A has a density as measured on the fluff of at least 0.950 g/cm 3 .
8. The metallocene-catalyzed polyethylene resin according to claim 1 , wherein polyethylene fraction A has a melt index MI2 as measured on the fluff of at least 40.0 g/10 min to at most 100 g/10 min.
9. The metallocene-catalyzed polyethylene resin according to claim 1 , comprising from 45% to at most 75% by weight of polyethylene fraction B based on the total weight of the polyethylene resin.
10. The metallocene-catalyzed polyethylene resin according to claim 1 , wherein each fraction is prepared in different reactors of at least two reactors connected in series.
11. The metallocene-catalyzed polyethylene resin according to claim 1 , wherein each fraction is prepared in different reactors of at least two slurry loop reactors connected in series.
12. An article comprising the metallocene-catalyzed polyethylene resin according to claim 1 .
13. The article according to claim 12 , wherein the article is produced by a polymer processing technique selected from the group comprising rotomolding, blow molding, injection molding, compression molding, film casting, 3D printing, extrusion, and thermoforming.
14. The article according to claim 12 wherein the article is a tank, a drum, a container, a bin, a vat, a jerrycan, a can, a cistern, a bottle, boat or parts thereof, floats, buoys, fibers, caps and closure, cast film, structural parts.