Process for making ultra-low molecular weight ethylene polymers and blends thereof
AssigneeThe Dow Chemical Company
InventorsMalcolm F. Finlayson, Craig C. Garrison, Ralph E. Guerra, Martin J. Guest, Brian W. S. Kolthammer, Deepak R. Parikh, Steven M. Ueligger
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Abstract
Process for making a non-pourable ultra-low molecular weight ethylene polymer composition and blends thereof. Such polymer compositions tend to have longer lamella and a greater degree of crystalline organization than corresponding higher molecular weight materials at an equivalent density.
Claims38
A process comprising reacting ethylene and at least one ethylenically unsaturated comonomer at a reaction temperature of at least 80° C. in the presence of a constrained geometry catalyst to form a non-pourable homogeneous ultra-low molecular weight ethylene polymer which is characterized as having a number average molecular weight (Mn) of no more than 11,000, a molecular weight distribution, Mw/Mn, as determined by gel permeation chromatography, of from 1.5 to 2.5, and a pour point of at least −30° C. as determined by ASTM Method No. D97.
A process for making an ethylene polymer, comprising:
- reacting ethylene with at least one ethylenically unsaturated comonomer in a reactor in the presence of a constrained geometry catalyst;
- maintaining an ethylene concentration in the reactor within a selected range that is below about 8 percent by weight of contents in the reactor;
- maintaining a reaction temperature in the reactor within a selected range that is above about 80° C.;
- and
- forming a polymer having the following characteristics:
- (i) a number average molecular weight (Mn) that is no more than about 11,000 as determined by gel permeation chromatography;
- (ii) a molecular weight distribution (Mw/Mn) that is less than about 3.5 as determined by gel permeation chromatography;
- (iii) a pour point that is greater than about −30° C. as determined by ASTM Method No. D97;
- and
- (iv) a density that is greater than about 0.850 g/cm3.
The process of claim K wherein the polymer density is between about 0.86 g/cm3 and about 0.88 g/cm3.
A process for making an ethylene polymer, comprising:
- reacting ethylene with at least one ethylenically unsaturated comonomer in a reactor in the presence of a constrained geometry catalyst at a reaction temperature of at least about 80° C., thereby forming a polymer having the following characteristics:
- (i) a number average molecular weight (Mn) of no more than about 11,000 as determined by gel permeation chromatography;
- (ii) a molecular weight distribution (Mw/Mn) between about 1.5 and about 2.5 as determined by gel permeation chromatography;
- (iii) a pour point of greater than about −30° C. as determined by ASTM Method No. D97;
- and
- (iv) a density that is greater than about 0.850 g/cm3.
A process for making an ethylene homopolymer, comprising:
- reacting ethylene in a reactor in the presence of a constrained geometry catalyst at a reaction temperature of at least about 80° C., thereby forming a homopolymer having the following characteristics:
- (i) a number average molecular weight (Mn) of no more than about 11,000 as determined by gel permeation chromatography;
- (ii) a molecular weight distribution (Mw/Mn) between about 1.5 and about 2.5 as determined by gel permeation chromatography;
- and
- (iii) a pour point of greater than about −30° C. as determined by ASTM Method No. D97.
A process for making a fiber blend, comprising:
- carrying out a polymerization reaction in a reactor in the presence of a catalyst at a reaction temperature of at least about 80° C., thereby forming a polymer comprising ethylene and having the following characteristics:
- (i) a number average molecular weight (Me) of no more than about 11,000 as determined by gel permeation chromatography;
- (ii) a molecular weight distribution (Mw/Mn) between about 1.5 and about 2.5 as determined by gel permeation chromatography;
- (iii) a pour point of greater than about −30° C. as determined by ASTM Method No. D97;
- and
- (iv) a density that is greater than about 0.850 g/cm3;
- and
- combining the polymer with a natural or synthetic fiber having different properties than the polymer.
A process for making a polymer blend, comprising:
- carrying out a polymerization reaction in a reactor in the presence of a catalyst at a reaction temperature of at least about 80° C., thereby forming a polymer comprising ethylene and having the following characteristics:
- (i) a number average molecular weight (Mn) of no more than about 11,000 as determined by gel permeation chromatography;
- (ii) a molecular weight distribution (Mw/Mn) between about 1.5 and about 2.5 as determined by gel permeation chromatography;
- (iii) a pour point of greater than about −30° C. as determined by ASTM Method No. D97;
- and
- (iv) a density that is greater than about 0.850 g/cm3;
- and combining the polymer with at least one other natural or synthetic polymer.
Dependencies are inferred from the claim text.