Ethylene interpolymer products having intermediate branching
This disclosure relates to ethylene interpolymer product having intermediate branching. Intermediate branching was defined as branching that was longer than the branch length due to comonomer and shorter than the entanglement molecular weight (M e ). Intermediately branched ethylene interpolymer products were produced in a continuous solution polymerization process employing an intermediate branching catalyst formulation. Intermediately branched ethylene interpolymer products were characterized by a Non-Comonomer Index Distribution (NCID i ), a melt index from 0.3 to 500 dg/minute, a density from 0.858 to 0.965 g/cm 3 , a polydispersity (M w /M n ) from about 2 to about 25 and a CDBI 50 from about 10% to about 98%. A method based on triple detection cross fractionation chromatography (3D-CFC) was disclosed to measure NCID i .
1. An ethylene interpolymer product comprising:
(i) a first ethylene interpolymer;
(ii) a second ethylene interpolymer, and;
(iii) optionally a third ethylene interpolymer;
wherein said second ethylene interpolymer is characterized by an intermediate branching, wherein said intermediate branching is characterized by a Non-Comonomer Index Distribution, NCID i , having a value characterized by Eq. (1a) and Eq. (1b);
NCID i ≤1.000−0.00201(log M i −log M o +4.93)+0.00137(log M i −log M o +4.93) 2 −0.00034(log M i −log M o +4.93) 3 Eq. (1a)
NCID i ≥0.730−0.00388(log M i −log M o +4.93)+0.00313(log M i −log M o +4.93) 2 −0.00069(log M i −log M o +4.93) 3 Eq. (1b)
wherein, M o is a peak molecular weight that characterizes a molecular weight distribution of said second ethylene interpolymer when fit to a log normal distribution and M i is an incremental molar mass that characterizes said molecular weight distribution; wherein a first derivative of said NCID i ,
dNCID
i
d
log
M
i
,
Eq. (2),
dNCID
i
d
log
M
i
=
β
1
+
2
β
2
(
log
M
i
-
log
M
o
+
4.93
)
+
3
β
3
(
log
M
i
-
log
M
o
+
4.93
)
2
Eq
.
(
2
)
has a value of ≤−0.0001, coefficients β 0 , β 1 , β 2 and β 3 are generated by fitting said NCID i of said second ethylene interpolymer to a third order polynomial, Eq. (3),
NCID i =β 0 +β 1 (log M i −log M o +4.93)+β 2 (log M i −log M o +4.93) 2 +β 3 (log M i −log M o +4.93) 3 Eq. (3)
wherein said NCID i of said second ethylene interpolymer is obtained by deconvoluting an experimentally measured Non-Comonomer Index Distribution of said ethylene interpolymer product;
wherein said ethylene interpolymer product contains long chain branching as characterized by a dimensionless Long Chain Branching Factor, LCBF, having a value of ≥0.001.
2. The ethylene interpolymer product of claim 1 , wherein said first ethylene interpolymer is synthesized using a homogenous catalyst formulation and said second ethylene interpolymer is synthesized using an intermediate branching catalyst formulation.
3. The ethylene interpolymer product of claim 2 , wherein said homogeneous catalyst formulation is a bridged single site catalyst formulation and said intermediate branching catalyst formulation is an in-line intermediate branching catalyst formulation or a batch intermediate branching catalyst formulation.
4. The ethylene interpolymer product of claim 1 having a melt index from about 0.3 to about 500 dg/minute and a density from about 0.858 to about 0.965 g/cc; wherein melt index is measured according to ASTM D1238 (2.16 kg load and 190° C.) and density is measured according to ASTM D792.
5. The ethylene interpolymer product of claim 1 having a M w /M n from about 2 to about 25.
6. The ethylene interpolymer product of claim 1 having a CDBI 50 from about 10% to about 98%; wherein CDBI 50 is defined as the percent of said ethylene interpolymer product having a comonomer composition within 50% of the median comonomer composition as determined by CTREF.
7. The ethylene interpolymer product of claim 1 ; wherein
(i) said first ethylene interpolymer has a melt index from about 0.001 to about 1000 dg/minute, a density from about 0.855 g/cm 3 to about 0.975 g/cc and is from about 0 to 60 weight percent of said ethylene interpolymer product;
(ii) said second ethylene interpolymer has melt index from about 0.001 to about 1000 dg/minute, a density from about 0.89 g/cm 3 to about 0.965 g/cc and is from about 10 to 99 weight percent of said ethylene interpolymer product;
(iii) optionally said third ethylene interpolymer has a melt index from about 0.1 to about 10000 dg/minute, a density from about 0.855 to about 0.975 g/cc and is from 0 to about 30 weight percent of said ethylene interpolymer product;
wherein melt index is measured according to ASTM D1238 (2.16 kg load and 190° C.), density is measured according to ASTM D792 and weight percent is the weight of said first, said second or said optional third ethylene interpolymer divided by the weight of said ethylene interpolymer product.
8. The ethylene interpolymer product of claim 1 synthesized using a solution polymerization process.
9. The ethylene interpolymer product of claim 1 further comprising from 0.001 to about 10 mole percent of one or more α-olefin.
10. The ethylene interpolymer product of claim 9 ; wherein said one or more α-olefin are C 3 to C 10 α-olefins.
11. The ethylene interpolymer product of claim 10 ; wherein said one or more α-olefin is 1-hexene, 1-octene or a mixture of 1-hexene and 1-octene.
12. The ethylene interpolymer product of claim 1 wherein said third ethylene interpolymer is synthesized using a heterogeneous catalyst formulation or a homogeneous catalyst formulation or an intermediate branching catalyst formulation.
13. The ethylene interpolymer product of claim 1 ; wherein said first ethylene interpolymer has a first CDBI 50 from about 20 to about 98%, said second ethylene interpolymer has a second CDBI 50 from about 20 to about 70% and said optional third ethylene interpolymer has a third CDBI 50 from about 20 to about 98%.
14. The ethylene interpolymer product of claim 13 ; wherein said first CDBI 50 is higher than said second CDBI 50 .