Polypropylene polymers
AssigneeExxonMobil Chemical Patents Inc.
InventorsChon-Yie Lin, Bernard Louis Bossert, Chen Michael Chia-Chao, Susan Chia-Yu Yeh
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Abstract
Embodiments of the present invention include a polypropylene homopolymer synthesized from a metallocene catalyst system and methods of forming the homopolymer, the homopolymer having an aluminum and chlorine recoverables value of less than 25 ppm and a xylene solubles of less than 1 wt % relative to the total weight of the homopolymer. The resulting homopolymer has other desirable properties such as a heat deflection temperature at 0.45 MPa of from 90° C. to 110° C., and a MWD value of from 1.7 to 5.0. These properties make embodiments of the homopolymer desirable for films, and in particular for capacitor films.
Claims45
An isotactic polyproplene homopolymer having an aluminum and chlorine recoverables value of less than 10 ppm and a xylene solubles of less than 1 wt % relative to the total weight of the polymer.
An isotactic polypropylene homopolymer having at least a 93 mol % 13C NMR detectable pentad content, and having an aluminum and chlorine recoverables value of less than 10 ppm.
The homopolymer of claim 8, wherein the homopolymer has a heat deflection temperature at 0.45 MPa of from 90° C. to 110° C.
The homopolymer of claim 8, wherein the homopolymer has a heat deflection temperature at 0.45 MPa of from 95° C. to 105° C.
A polypropylene film comprising isotactic polypropylene homopolymer having an aluminum and chlorine recoverables value of less that 10 ppm and xylene solubles of less than 1 wt % relative to the total weight of the homopolymer.
The film of claim 15, wherein the homopolymer has a heal deflection temperature at 0.45 MPa of from 90° C. to 110° C.
The film of claim 15, wherein the homopolymer has a heat deflection temperature at 0.45 MPa of from 95° C. to 105° C.
The film of claim IS, further having a MWD of from 1.7 to 5.0.
The film of claim 15, further having a MWD of from 1.7 to 7.0.
A two-step process for producing isotactic polypropylene homopolymer, said process comprising the steps of:
- (a) first, polymerizing propylene in the presence of a metallocene, an activator compound, and a first concentration of chain transfer agent sufficient to produce a first propylene homopolymer;
- (b) second, polymerizing propylene in the presence of the first propylene homopolymer, and also in the presence of a second concentration of chain transfer agent sufficient to produce the isotactic polypropylene having an aluminum and chlorine recoverables value of less than 10 ppm;
- and
- (c) recovering isotactic polypropylene.
The process of claim 24, wherein the homopolymer has a heat deflection temperature at 0.45 MPa of from 90° C. to 110° C.
The process of claim 24, wherein the homopolymer has a heat deflection temperature at 0.45 MPa of from 95° C. to 105° C.
The process of claim 24, wherein the first polypropylene homopolymer has an MWD in the range from 0.3 to 3.5.
The process of claim 24, further having a xylene solubles of less than 1 wt % relative to the total weight of the homopolymer.
The process of claim 24, wherein the metallocene is a single metallocene.
The process of claim 24, wherein the single metallocene is present in step (b).
The process of claim 33, wherein the activator compound is selected from the group consisting of trisperfluorophenylboron, tris(3,5-di(tri fluoromethyl)phenyl)boron, tris(di-t-butylmethylsilyl)perfluorophenylboron, and mixtures thereof.
A two-step process for producing isotactic polypropylene homopolymer, said process comprising the steps of:
- (a) first, polymerizing propylene in the presence of a metallocene, a highly fluorinated trisarylboron activator compound, and a first concentration of chain transfer agent sufficient to produce a first propylene homopolymer;
- (b) second, polymerizing propylene in the presence of the first propylene homopolymer, and also in the presence of a second concentration of chain transfer agent sufficient to produce the isotactic polypropylene having an aluminum and chlorine recoverables value of less than 10 ppm;
- and
- (c) recovering isotactic polypropylene.
The process of claim 35, wherein the homopolymer has a heat deflection temperature at 0.45 MPa of from 90° C. to 110° C.
The process of claim 35, wherein the homopolymer has a heat deflection temperature at 0.45 MPa of from 95° C. to 105° C.
The process of claim 35, wherein the first polypropylene homopolymer has an MWD in the range from 0.3 to 3.5.
The process of claim 35, further having a xylene solubles of less than 1 wt % relative to the total weight of the homopolymer.
The process of claim 35, wherein the metallocene is a single metallocene.
The process of claim 35, wherein the single metallocene is present in Step (b).
The process of claim 35, wherein the activator compound is selected from the group consisting of trisperfluorophenylboron, tris(3,5-di(trifluorometlhyl)phenyl)boron, tris(di-t-butylmethlylsilyl)perfluorophenylboron, and mixtures thereof.
The process of claim 35, wherein the isotactic polypropylene is washed.
A polypropylene polymer made by contacting α-olefin monomers in the presence of a metallocene catalyst system comprising at least one bridged 2,4 di-substituted metallocene and at least one non-coordinating anion activator supported on a fluorided support composition.
The polymer of claim 46, wherein the polymer is isotactic.
The polymer of claim 46, wherein the polymer is a homopolymer of propylene derived units.
The polymer of claim 46, wherein the aluminum and chlorine recoverables value is less than 15 ppm.
The polymer of claim 46, wherein the aluminum and chlorine recoverables value is less than 10 ppm.
The polymer of claim 46, wherein the homopolymer has a heat deflection temperature at 0.45 MPa of from 90° C. to 110° C.
The polymer of claim 46, wherein the homopolymer has a heat deflection temperature at 0.45 MPa of from 95° C. to 105° C.
The polymer of claim 46, wherein the MWD of the homopolymer is from 1.7 to 5.0.
The polymer of claim 46, wherein the at least one metallocene is a bridged 4-phenyl indenyl metallocene.
The polymer of claim 46, wherein the MWD of the homopolymer is from 1.7 to 7.0.
Dependencies are inferred from the claim text.