Olefin-block copolymers and their use in elastomeric articles

Patent metadata

Field	Value
Publication number	US-10822480-B2
Application number	US-201816122588-A
Country	US
Kind code	B2
Filing date	Sep 5, 2018
Priority date	Oct 26, 2017
Publication date	Nov 3, 2020
Grant date	Nov 3, 2020

Abstract

An elastomeric article comprising an olefin-block copolymer comprising within a range from 4 to 40 mol % of C4 to C12 α-olefin derived units, the remainder being ethylene-derived units, wherein the melting point temperature (T m2 ) is within a range from 92° C. to 120° C., and having an M w /M n value of less than 2.5. The olefin-block copolymer is desirably generated by combining ethylene, C4 to C12 α-olefins, a single site catalyst, preferably a fluxional catalyst, and an activator. The elastomeric article may be an elastic hygiene garment, especially a garment comprising a waistband, stretch ear panels and/or belly bands.

First claim

The invention claimed is:

1. An elastomeric article comprising an olefin-block copolymer comprising within a range from 4 to 40 mol % of C4 to C12 α-olefin derived units, the remainder being ethylene-derived units, wherein the olefin-block copolymer has a melting point temperature (T m2 ) from 92° C. to 120° C. and an M w /M n value of less than 2.5, wherein the olefin-block copolymer comprises a plurality of first blocks comprising from 20 mol % to 80 mol % of C4 to C12 α-olefin derived units and a plurality of second blocks comprising from 40 mol % to 5 mol % of C4 to C12 α-olefin derived units, wherein the first blocks comprise a greater amount of comonomer-derived units than the second blocks by at least 2 mol %.

2. The elastomeric article of claim 1 , wherein the olefin-block copolymer is generated by combining ethylene, at least one C4 to C12 α-olefin, a single-site catalyst, and an activator.

3. The elastomeric article of claim 1 , wherein the olefin-block copolymer has a M w within a range from 100,000 g/mole to 300,000 g/mole and a melt index (MI) of less than 1.4 g/10 min.

4. The elastomeric article of claim 1 , wherein the olefin-block copolymer has a peak melting point temperature (T m ) within a range from 92° C. to 110° C. and the olefin-block copolymer has 4 mol % to 20 mol % overall comonomer content.

5. The elastomeric article of claim 1 , wherein the C4 to C12 α-olefin derived units comprise 1-hexene or 1-octene.

6. The elastomeric article of claim 1 , wherein the olefin-block copolymer has a first permanent set of less than 100% at 23° C.

7. The elastomeric article of claim 1 , wherein the olefin-block copolymer has a first permanent set of less than 100% at 37° C.

8. The elastomeric article of claim 1 , wherein the olefin-block copolymer has a second permanent set of less than 100% at 23° C.

9. The elastomeric article of claim 1 , wherein the olefin-block copolymer has a second permanent set of less than 100% at 37° C.

10. The elastomeric article of claim 1 , wherein the olefin-block copolymer exhibits a peak load of less than 8 MPa at 23° C.

11. The elastomeric article of claim 1 , wherein the olefin-block copolymer exhibits a mechanical hysteresis of less than 60% at 37° C.

12. The elastomeric article of claim 1 , wherein the olefin-block copolymer is produced in a single stage in a single reactor using only one single-site catalyst.

13. The elastomeric article of claim 12 , wherein the single-site catalyst is a fluxional catalyst represented by the formula:

where M is titanium, zirconium, or hafnium; z is 0, 1, 2, 3, 4, 5, 6, 7, or 8 indicating the number of R′ groups bound to the bridging group T, p is 1, 2 or 3 indicating the number of L groups bound to the bridging group T;
each X is independently selected from the group consisting of C1 to C10 alkyl group, a C6 to C24 aryl group, or a C7 to C40 alkylaryl group, hydrides, amides, alkoxides, sulfides, phosphides, halides, dienes, amines, phosphines, ethers, and combinations thereof, provided that two X's may form a part of a fused ring or a ring system;
T is a bridging group bound to each of the cyclopentadienyl groups;
each R 1 , R 2 , R 3 , and R 4 is, independently, hydrogen, a hydrocarbyl group, a substituted hydrocarbyl group, an aryl group, a substituted aryl group, or a heteroatom-containing group, provided that any of adjacent R 1 , R 2 , R 3 , and R 4 groups may form a fused ring or multicenter fused ring system where the rings may be aromatic, partially saturated or saturated;
each R′ is independently hydrogen, a C1 to C10 alkyl group, a C6 to C24 aryl group, or a C7 to C40 alkylaryl group;
each L is a heteroatom or heteroatom-containing fluxional group bound to T; and
JS′ z*-1-y is a heteroatom ligand in which “J” is a nitrogen, sulfur, oxygen or phosphorous atom; and S′ is a radical group which is a hydrocarbyl, substituted hydrocarbyl, or heteroatom; where z*is the coordination number of the element “J”, and y is 0 or 1.

14. The elastomeric article of claim 13 , wherein the “L” group is represented by the formula:

where the open bond is to T, and Q is a divalent C1 to C6 hydrocarbyl linker group bound to T; each Y is independently a hydrogen, heteroatom, heteroatom-containing group, C1 to C10 hydrocarbyl, C2 to C12 substituted hydrocarbyl, C6 to C12 aryl, or C7 to C20 substituted aryl, provided that at least one Y in each formula is a heteroatom or heteroatom-containing group; and n is 0, 1, 2, 3, 4, 5 or 6.

15. The elastomeric article of claim 1 , wherein the article is an elastic hygiene garment.

16. The elastomeric article of claim 15 , wherein the garment comprises waistband, a stretch ear panel and/or belly band.

17. The elastomeric article of claim 1 , wherein the plurality of second blocks comprise from 40 mol % to 10 mol % of the C4 to C12 α-olefin derived units.

18. The elastomeric article of claim 1 , wherein the first blocks comprise a greater amount of comonomer-derived units than the second blocks by at least 4 mol %.

19. The elastomeric article of claim 1 , wherein the first blocks comprise a greater amount of comonomer-derived units than the second blocks by at least 6 mol %.

20. The elastomeric article of claim 1 , wherein the first blocks comprise a greater amount of comonomer-derived units than the second blocks by at least 8 mol %.

21. An elastomeric article comprising an olefin-block copolymer comprising within a range from 4 to 40 mol % of C4 to C12 α-olefin derived units and ethylene-derived units, wherein the olefin-block copolymer has a melting point temperature (T m2 ) from 92° C. to 120° C., an M W /M n value of less than 2.5, and a mechanical hysteresis of less than 50% at 37° C.

22. The elastomeric article of claim 21 , wherein the olefin-block copolymer comprises a plurality of C4 to C12 α-olefin rich blocks comprising from 20 mol % to 80 mol % of the C4 to C12 α-olefin derived units and a plurality of the C4 to C12 α-olefin poor blocks comprising from 40 mol % to 5 mol % of the C4 to C12 α-olefin derived units.

23. The elastomeric article of claim 21 , wherein the C4 to C12 α-olefin derived units comprise 1-hexene.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Zhang Jingwen
• Stewart Ian C
• Lu Jiemin

Classifications

• C08F210/16 Primary

  Copolymers of ethene with alpha-alkenes, e.g. EP rubbers · CPC title

• C08F2420/10

  Heteroatom-substituted bridge, i.e. Cp or analog where the bridge linking the two Cps or analogs is substituted by at least one group that contains a heteroatom · CPC title

• C08F2410/01

  Additive used together with the catalyst, excluding compounds containing Al or B · CPC title

• C08F4/65908

  in combination with an ionising compound other than alumoxane, e.g. (C6F5)4B-X+ · CPC title

• C08F4/65912

  in combination with an organoaluminium compound · CPC title