Passivated supports: catalyst, process, product and film
Ethylene copolymers made in the gas phase using a phosphinimine based single site catalyst supported on a passivated inorganic oxide support. The ethylene copolymers have a relatively narrow molecular weight distribution and good rheological parameters.
1. An olefin polymerization process to produce an ethylene copolymer, the process comprising contacting ethylene and at least one alpha olefin having from 3-8 carbon atoms with a polymerization catalyst in a gas phase reactor;
wherein the ethylene copolymer has a density of from 0.916 g/cm 3 to 0.936 g/cm 3 , a melt index (I 2 ) of from 0.1 g/10 min to 2.0 g/10 min, a melt flow ratio (I 21 /I 2 ) of greater than 22 but less than 42, a molecular weight distribution (M w /M n ) of from 2.3 to 5.0, a reverse comonomer distribution profile as determined by GPC-FTIR, and a composition distribution breadth index CDBI 50 of from 45 wt % to 80 wt % as determined by TREF; the polymerization catalyst comprises a phosphinimine catalyst, a passivated support and a co-catalyst; and the passivated support comprises silica which has been treated with i) an organoaluminum compound and ii) magnesium chloride;
wherein the magnesium chloride is generated by addition of a diorganomagnesium compound and a source of chloride to the organoaluminum treated silica, provided that the source of chloride is not a transition metal chloride.
2. The process of claim 1 wherein the ethylene copolymer has a CDBI 50 of from 50% to 75 wt %.
3. The process of claim 1 wherein the ethylene copolymer has a molecular weight distribution (M w /M n ) of from 2.6 to 4.6.
4. The process of claim 1 wherein the ethylene copolymer has a melt flow ratio (I 21 /I 2 ) of from 24 to 40.
5. The process of claim 1 wherein the ethylene copolymer has a bimodal TREF profile.
6. The process of claim 1 wherein the ethylene copolymer has a z-average molecular weight distribution (M z /M w ) of from 1.75 to 3.0.
7. The process of claim 1 wherein the alpha-olefin is 1-hexene.
8. The process of claim 1 wherein the ethylene copolymer has a bimodal TREF profile comprising two intensity maxima occurring at elution temperatures T(low) and T(high); wherein T(low) occurs at from 75° C. to 90° C. and T(high) occurs at from 90° C. to 98° C., provided that T(low) is lower than T(high).
9. The process of claim 1 wherein the ethylene copolymer has a bimodal TREF profile defined by two elution intensity maxima occurring at elution temperatures T(low) and T(high); wherein T(low) occurs at from 75° C. to 89° C., T(high) occurs at from 90° C. to 98° C., and wherein T(high)-T(low) is from 3° C. to 15° C.
10. The process of claim 1 wherein the ethylene copolymer has a bulk density of 26 lb/ft 3 or greater.
11. The process of claim 1 wherein the passivated support is prepared in a non-polar hydrocarbon solvent or diluent.
12. The process of claim 1 wherein the polymerization catalyst system further comprises a catalyst modifier.
13. The process of claim 1 wherein the phosphinimine catalyst has the formula: (1-R ¥ -Indenyl)((t-Bu) 3 P═N)TiX 2 , where R ¥ is an alkyl group, an aryl group or a benzyl group and wherein each of the alkyl group, the aryl group, and the benzyl group is unsubstituted or is substituted by at least one fluoride atom; and X is an activatable ligand.
14. The process of claim 13 wherein the phosphinimine catalyst has the formula: (1-R ¥ -Indenyl)((t-Bu) 3 P═N)TiX 2 , where R ¥ is a benzyl group substituted by at least one fluoride atom; and X is an activatable ligand.
15. The process of claim 14 wherein the phosphinimine catalyst has the formula: (1-C 6 F 5 CH 2 -Indenyl)((t-Bu) 3 P═N)TiX 2 , where X is an activatable ligand.
16. An olefin polymerization process to produce an ethylene copolymer, the process comprising contacting ethylene and at least one alpha olefin having from 3-8 carbon atoms with a polymerization catalyst in a single gas phase reactor; the ethylene copolymer having a density of from 0.916 g/cm 3 to 0.936 g/cm 3 , and a melt flow ratio (I 21 /I 2 ) of greater than 22 but less than 42; wherein the polymerization catalyst comprises a phosphinimine catalyst, a passivated support, and a co-catalyst; and the passivated support comprises silica which has been treated with i) an organoaluminum compound and ii) magnesium chloride; wherein the magnesium chloride is generated by addition of a diorganomagnesium compound and a source of chloride to the organoaluminum treated silica, provided that the source of chloride is not a transition metal chloride; and wherein the phosphinimine catalyst has the formula: (1-R ¥ -Indenyl)((t-Bu) 3 P═N)TiX 2 , where R ¥ is an alkyl group, an aryl group or a benzyl group and wherein each of the alkyl group, the aryl group, and the benzyl group is unsubstituted or is substituted by at least one fluoride atom; and X is an activatable ligand.
17. An ethylene copolymer having a density of from 0.916 g/cm 3 to 0.936 g/cm 3 , a melt index (I 2 ) of from 0.1 g/10 min to 2.0 g/10 min, a melt flow ratio (I 21 /I 2 ) of greater than 22 but less than 40, a molecular weight distribution (M w /M n ) of from 2.5 to 4.5, a z-average molecular weight distribution (M z /M w ) of less than 3.0, a reverse comonomer distribution profile as determined by GPC-FTIR, and a composition distribution breadth index CDBI 50 of from 50 wt % to 80 wt % as determined by TREF, and a bimodal TREF profile; wherein the ethylene copolymer is made in a single gas phase reactor using a polymerization catalyst comprising: a phosphinimine catalyst, a passivated support and a co-catalyst; wherein the passivated support comprises silica which has been treated with i) an organoaluminum compound and ii) magnesium chloride; and wherein the magnesium chloride is generated by addition of a diorganomagnesium compound and a source of chloride to the organoaluminum treated silica, provided that the source of chloride is not a transition metal chloride.
18. A film layer comprising an ethylene copolymer having a density of from 0.916 g/cm 3 to 0.936 g/cm 3 , a melt index (I 2 ) of from 0.1 g/10 min to 2.0 g/10 min, a melt flow ratio (I 21 /I 2 ) of greater than 22 but less than 40, a molecular weight distribution (M w /M n ) of from 2.5 to 4.5, a z-average molecular weight distribution (M z /M w ) of less than 3.0, a reverse comonomer distribution profile as determined by GPC-FTIR, and a composition distribution breadth index CDBI 50 of from 50 wt % to 80 wt % as determined by TREF, and a bimodal TREF profile; wherein the ethylene copolymer is made in a single gas phase reactor using a polymerization catalyst comprising: a phosphinimine catalyst, a passivated support and a co-catalyst; wherein the passivated support comprises silica which has been treated with i) an organoaluminum compound and ii) magnesium chloride; and wherein the magnesium chloride is generated by addition of a diorganomagnesium compound and a source of chloride to the organoaluminum treated silica, provided that the source of chloride is not a transition metal chloride.
19. The film layer of claim 18 , having a haze of less than 15% at 1 mil thickness, and a gloss at 45° of at least 35 at 1 mil thickness.