Catalytic olefin block copolymers with controlled block sequence distribution and at least one low crystallinity hard block
AssigneeDow Global Technologies LLC
InventorsColin Li Pi Shan, Roger L. Kuhlman, Gary L. Rath, Pamela J. Kenny, Morgan M. Hughes, Rongjuan Cong
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Abstract
The invention is related to catalytic olefin block copolymers with a controlled block sequence distribution and at least one low crystallinity hard block. The block copolymer has a number of unique characteristics disclosed here.
Claims8
An ethylene/α-olefin interpolymer comprising two or more intramolecular segments or blocks comprising differing chemical or physical properties, said intramolecular segments characterized by possessing a most probable molecular weight distribution, wherein the ethylene/α-olefin interpolymer comprises a hard segment and a soft segment, and:
- (a) has a Mw/Mn from about 1.7 to about 3.5;
- (b) has an ethylene content in the hard segment in the range of from 70 wt % to 85 wt % based on based on total monomer content in hard segment;
- (c) (i) has a hard segment in an amount of at least 40%, at least one melting point, Tm, in degrees Celsius and an amount of ethylene in weight percent, wt % C2, wherein the numerical values of Tm and wt % C2 correspond to the relationship:
- 90° C.≧Tm≧4.1276(wt % C2)−244.76;
- or
- (ii) has a hard segment composition of less than 40%, at least one melting point, Tm, in degrees Celsius and an amount of ethylene in weight percent, wt % C2, wherein the numerical values of Tm and wt % C2 correspond to the relationship:
- 80° C.≧Tm≦4.1276(wt % C2)−264.95;
- or
- (iii) is characterized by an average block index greater than zero and up to about 1.0;
- or
- (iv) has a molecular fraction which elutes between 0° C. and 130° C. when fractionated using low temperature TREF, characterized in that the fraction has a molar comonomer content of at least 5 percent higher than that of a comparable random ethylene interpolymer fraction eluting between the same temperatures, wherein said comparable random ethylene interpolymer has the same comonomer(s) and has a melt index, density, and molar comonomer content (based on the whole polymer) within 10 percent of that of the ethylene/α-olefin interpolymer;
- or
- (v) has a relationship between ethylene content in wt % and log molecular weight such that a line plotted of ethylene content vs log molecular weight as measured by GPC-IR has an absolute slope, m, of equal to or less than 4;
- and,
- (d) has a turbidity measurement of a 1.0 wt % solution of the ethylene/α-olefin interpolymer in oil or a 1.5 wt % solution in dodecane of less than or equal to that of a comparable copolymer wherein the comparable copolymer has the same DSC enthalpy (J/g) at greater than 55° C. within ±5 J/g and the same overall ethylene content within 10%;
- and,
- wherein the soft segment comprises 35 wt % to 80 wt % comonomer based on total monomer content in the soft segment.
An ethylene/α-olefin interpolymer comprising two or more intramolecular segments or blocks comprising differing chemical or physical properties, said intramolecular segments characterized by possessing a most probable molecular weight distribution, wherein the ethylene/α-olefin interpolymer comprises a hard segment and a soft segment, and:
- (a) has a Mw/Mn from about 1.7 to about 3.5;
- (b) has an ethylene content in the hard segment in the range of from 70 wt % to 85 wt % based on based on total monomer content in hard segment;
- (c) (i) has a hard segment in an amount of at least 40%, at least one melting point, Tm, in degrees Celsius and an amount of ethylene in weight percent, wt % C2, wherein the numerical values of Tm and wt % C2 correspond to the relationship:
- 0° C.≧Tm≧3.4405(wt % C2)−218.99;
- or
- (ii) has a hard segment composition of less than 40%, at least one melting point, Tm, in degrees Celsius and an amount of ethylene in weight percent, wt % C2, wherein the numerical values of Tm and wt % C2 correspond to the relationship:
- 80° C.≧Tm≦4.1276(wt % C2)−264.95;
- or
- (iii) is characterized by an average block index greater than zero and up to about 1.0;
- or
- (iv) has a molecular fraction which elutes between 0° C. and 130° C. when fractionated using low temperature TREF, characterized in that the fraction has a molar comonomer content of at least 5 percent higher than that of a comparable random ethylene interpolymer fraction eluting between the same temperatures, wherein said comparable random ethylene interpolymer has the same comonomer(s) and has a melt index, density, and molar comonomer content (based on the whole polymer) within 10 percent of that of the ethylene/α-olefin interpolymer;
- or
- (v) has a relationship between ethylene content in wt % and log molecular weight such that a line plotted of ethylene content vs log molecular weight as measured by GPC-IR has an absolute slope, m, of equal to or less than 4;
- and,
- (d) has a turbidity measurement of a 1.0 wt % solution of the ethylene/α-olefin interpolymer in oil or a 1.5 wt % solution in dodecane of less than or equal to that of a comparable copolymer wherein the comparable copolymer has the same DSC enthalpy (J/g) at greater than 55° C. within ±5 J/g and the same overall ethylene content within 10%;
- and,
- wherein the soft segment comprises 35 wt % to 80 wt % comonomer based on total monomer content in the soft segment.
Dependencies are inferred from the claim text.