Linear low density polyethylene for film applications
The present disclosure generally relates to catalyst systems, polyethylene compositions, and uses of such compositions in, e.g., films. In an embodiment is provided a film that includes a polyethylene composition, comprising: ethylene and a C 3 -C 40 olefin comonomer, the polyethylene composition having at least 75 wt % ethylene content and from 0 wt % to 25 wt % of a C 3 -C 40 olefin comonomer content based upon the total weight of the composition as determined by GPC-IR5-LS-VIS, the film having: an average of MD and TD 1% secant modulus of 42,000 psi or greater as determined by ASTM D-882, and a Dart Drop Impact of greater than 400 g/mil, as determined by ASTM D1709. In another embodiment is provided a process for producing a polyethylene composition, comprising: introducing, under first polymerization conditions, ethylene and a C 3 -C 40 alpha-olefin to a catalyst system in a reactor, the catalyst system comprising a first catalyst compound, a second catalyst compound, and an activator; and forming a polyethylene composition.
1 . A process for producing a polyethylene composition, comprising:
introducing, under first polymerization conditions, ethylene and a C 3 -C 40 alpha-olefin to a catalyst system in a reactor, the catalyst system comprising a first catalyst compound, a second catalyst compound, and an activator; and
forming a polyethylene composition, the first catalyst compound being represented by Formula (I)
wherein:
M is Ti, Hf, or Zr;
each of X 1 and X 2 is independently C 1 to C 20 hydrocarbyl radical, a functional group comprising elements from Groups 13 to 17 of the periodic table of the elements, or X 1 and X 2 join together to form a C 4 to C 62 cyclic or polycyclic ring structure;
each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 14 , R 15 , and R 16 is independently selected from hydrogen, halogen, C 1 -C 40 hydrocarbyl, substituted C 1 -C 40 hydrocarbyl, —NR′ 2 , —SR′, —OR′, —OSiR′3, or —PR′2, wherein each R′ is independently hydrogen, halogen, C 1 -C 10 alkyl, or C 6 -C 10 aryl, or one or more of R 1 and R 2 , R 2 and R 3 , R 3 and R 4 , R 4 and R 5 , R 1 and R 5 , R 14 and R 15 , and R 15 and R 16 join together to form a C 4 to C 62 cyclic or polycyclic ring structure;
each of R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 is independently selected from hydrogen, halogen, C 1 -C 40 hydrocarbyl, substituted C 1 -C 40 hydrocarbyl, aryl, substituted aryl, —NR′ 2 , —SR′, —OR′, —OSiR′ 3 , or —PR′ 2 , wherein each R′ is independently hydrogen, halogen, C 1 -C 10 alkyl, or C 6 -C 10 aryl, or one or more of R 7 and R 8 , R 8 and R 10 , and R 10 and R 12 are joined to form a saturated ring, unsaturated ring, substituted saturated ring, or substituted unsaturated ring;
and the second catalyst compound being represented by Formula (IIa) or Formula (IIb):
wherein:
each of R 6a , R 10a , R 11a , and R 15a are independently halogen, —CF 3 , or C 1 -C 22 -alkyl, C 2 -C 22 -alkenyl, C 6 -C 22 -aryl, arylalkyl (wherein alkyl has from 1 to 10 carbon atoms and aryl has from 6 to 20 carbon atoms), NR′2, —OR′, —SiR″ 3 or five-, six- or seven-membered heterocyclyl comprising at least one atom selected from N, P, O and S;
each of R 1a and R 2a is independently hydrogen, C 1 -C 22 -alkyl, C 2 -C 22 -alkenyl, C 6 -C 22 -aryl, arylalkyl wherein alkyl has from 1 to 10 carbon atoms and aryl has from 6 to 20 carbon atoms, or five-, six- or seven-membered heterocycle comprising at least one atom selected from N, P, O and S, wherein each of R 1a and R 2a is optionally substituted by halogen, —NR′ 2 , —OR′ or —SiR″3, wherein R 1a optionally bonds with R 3a , and R 2a optionally bonds with R 5a in each case to independently form a five-, six- or seven-membered ring;
each of R 3a , R 4a , R 5a , R 7a , R 8a , R 9a , R 12a , R 13a , and R 14a is independently hydrogen, C 1 -C 22 -alkyl, C 2 -C 22 -alkenyl, C 6 -C 22 -aryl, arylalkyl wherein alkyl has from 1 to 10 carbon atoms and aryl has from 6 to 20 carbon atoms, halogen, —NR′ 2 , —OR′, —SiR″ 3 or five-, six- or seven-membered heterocyclyl comprising at least one atom selected from N, P, O and S; and
each of X 1a and X 2a is independently hydrogen, halogen, C 1 -C 20 -alkyl, C 2 -C 10 -alkenyl, C 6 -C 20 -aryl, arylalkyl wherein alkyl has from 1 to 10 carbon atoms and aryl has from 6 to 20 carbon atoms, —NR′ 2 , —OR′, —SR′, —SO 3 R′, —OC(O)R′, —CN, —SCN, β-diketonate, —CO, —BF 4 − , —PF 6 − or bulky non-coordinating anion, or X 1a and X 2a optionally bond to form a five- or six-membered ring;
wherein the catalyst system is formed by steps including first adding the catalyst compound represented by Formula (IIa) or Formula (IIb) to a silica support with a first solvent to form a pre-treated iron silica support, then contacting the pre-treated iron silica support with the activator, and then contacting the pre-treated iron silica support with the catalyst compound represented by Formula (I) with a second solvent, wherein the first solvent and the second solvent are optionally different or same.
2 . The process of claim 1 , further comprising
introducing, under second polymerization conditions, a third catalyst compound to the reactor, the third catalyst compound being represented by Formula (I), Formula (IIIa), or Formula (IIIb):
wherein:
each of R 1b , R 2b , R 3b , R 4b , R 5b , R 8b , R 9b , R 10b , R 13b , R 14b , and R 15b is independently hydrogen, C 1 -C 22 alkyl, C 2 -C 22 alkenyl, C 6 -C 22 aryl, arylalkyl wherein alkyl has from 1 to 10 carbon atoms and aryl has from 6 to 20 carbon atoms, —OR 16b , —NR 17b 2 , halogen, —SiR 18b 3 or five-, six- or seven-membered heterocyclic ring comprising at least one atom selected from the group consisting of N, P, O and S;
each of R 6b , R 7b , R 11b , and R 12b , is independently C 1 -C 22 alkyl, C 2 -C 22 alkenyl, C 6 -C 22 aryl, arylalkyl wherein alkyl has from 1 to 10 carbon atoms and aryl has from 6 to 20 carbon atoms, —OR 16b , —NR 17b 2 , halogen, —SiR 18b 3 or five-, six- or seven-membered heterocyclic ring comprising at least one atom selected from the group consisting of N, P, O and S;
each of R 16b , R 17b , and R 18b is independently hydrogen, C 1 -C 22 alkyl, C 2 -C 22 alkenyl, C 6 -C 22 aryl, arylalkyl where alkyl has from 1 to 10 carbon atoms and aryl has from 6 to 20 carbon atoms, or —SiR 19b 3 , wherein each R 16b , R 17b , and R 18b is independently optionally substituted by halogen, or two R 16b radicals optionally bond to form a five- or six-membered ring, or two R 17b radicals optionally bond to form a five- or six-membered ring, or two R 18b radicals optionally bond to form a five- or six-membered ring;
each R 19b is independently hydrogen, C 1 -C 22 alkyl, C 2 -C 22 alkenyl, C 6 -C 22 aryl, arylalkyl where alkyl has from 1 to 10 carbon atoms and aryl has from 6 to 20 carbon atoms, or two R 19 radicals optionally bond to form a five- or six-membered ring;
each of E 1 , E 2 , and E 3 is independently carbon, nitrogen or phosphorus;
each of u 1 , u 2 , and u 3 is independently 0 if E 1 , E 2 , or E 3 is nitrogen or phosphorus, and each of u 1 , u 2 , and u 3 is independently 1 if E 1 , E 2 , or E 3 is carbon;
each of X 1b and X 2b is independently substituted hydrocarbyl, and the radicals X 1b and X 2b can be bonded with one another;
D is a neutral donor; and
t is 0 to 2.
3 . The process of claim 2 , wherein the third catalyst compound is
4 . The process of claim 2 , wherein a molar ratio of second catalyst to third catalyst can be from 95:5 to 5:95, from 80:20 to 20:80, from 70:30 to 30:70, from 60:40 to 40:60.
5 . The process of claim 1 , wherein each of X 1 and X 2 is independently hydrogen or halogen.
6 . The process of claim 1 , wherein each of R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 , R 8 , R 9 , R 10 , R 11 , R 12 , R 13 , R 14 , R 15 , and R 16 is independently hydrogen, halide, alkoxide, C 1 to C 12 substituted or unsubstituted hydrocarbyl, or —R″—SiR′ 3 or —R″—CR′ 3 where R″ is C 1 to C 4 hydrocarbyl.
7 . The process of claim 1 , wherein M is hafnium.
8 . The process of claim 1 , wherein the first catalyst compound is one or more of:
9 . The process of claim 1 , wherein the first catalyst compound is
10 . The process of claim 1 , wherein:
each of X 1a and X 2a is independently halogen; and
each of R 6a and R 15a is independently halogen.
11 . The process of claim 1 , wherein:
each of R 1a and R 2a is independently C 1 -C 20 hydrocarbyl;
each of R 3a , R 4a , and R 5a is independently hydrogen;
each of R 8a , R 10a , R 11a and R 13a is C 1 -C 20 hydrocarbyl;
each of R 7a , R 9a , R 12a and R 14a is independently hydrogen, C 1 -C 22 -alkyl, C 2 -C 22 -alkenyl, C 6 -C 22 -aryl, arylalkyl where alkyl has from 1 to 10 carbon atoms and aryl has from 6 to 20 carbon atoms, halogen, —NR′ 2 , —OR′, —SiR″ 3 or five-, six- or seven-membered heterocycle comprising at least one atom selected from the group consisting of N, P, O and S;
R′ is optionally substituted by halogen, or two R′ radicals bond to form a five- or six-membered ring; and
each R″ is independently hydrogen, C 1 -C 22 -alkyl, C 2 -C 22 -alkenyl, C 6 -C 22 -aryl or arylalkyl where alkyl has from 1 to 10 carbon atoms and aryl has from 6 to 20 carbon atoms, or two R″ radicals optionally bond to form a five- or six-membered ring.
12 . The process of claim 1 , wherein the second catalyst compound is one or more of:
13 . The process of claim 1 , wherein the second catalyst compound is
14 . The process of claim 1 , wherein a molar ratio of first catalyst compound to second catalyst compound is from 1:1 to 5:1, or from 0.6:0.4 to 0.9:0.2.