Stable star-structured functional polyolefins

Patent metadata

Field	Value
Publication number	US-10501642-B2
Application number	US-201514923002-A
Country	US
Kind code	B2
Filing date	Oct 26, 2015
Priority date	Dec 4, 2014
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

Stable star-structured functional polyolefins and methods of making them, the functional polyolefins comprising a polyolefin bound at any position along its chain length to at least one nucleophile-containing silane of the following formula:

wherein Y is a di- or trivalent linker group selected from heteroatoms, C1 to C10 alkylenes, and other groups disclosed herein; Nu is a nucleophilic atom or unsaturation group; R5 is selected from hydrogen, and C1 to C10 alkyls, and other groups as disclosed herein; X is a divalent group selected from linear and branched alkylenes and heteroatom-alkylenes, and other groups as disclosed herein; and PO is a polyolefin having a weight average molecular weight of at least 400 g/mole; with the proviso that at least one of R1, R2, and R3 is selected from the same or different functional polyolefin moieties. Star-structured functional polyolefins are useful as filler dispersive additives in tire formulations and processing aids.

First claim

The invention claimed is:

1. Star-structured functional polyolefins comprising:
a polyolefin bound at any position along its chain length to at least one nucleophile-containing silane of the following formula:

wherein:
Y is a di- or trivalent linker group selected from heteroatoms, C1 to C10 alkylenes, heteroatom substituted C1 to C10 alkylenes, C6 to C20 arylenes, and heteroatom substituted C6 to C20 arylenes;
R4 is selected from hydrogen, heteroatoms, and C1 to C10 alkyls;
Nu is a nucleophilic atom;
R5 is selected from hydrogen, and C1 to C10 alkyls, C1 to C10 aminoalkyls, C6 to C20 aryls, C7 to C22 alkylaryls, C 7 to C 22 aminoaryls, and C7 to C22 arylalkyls;
X is at least a divalent group selected from the group consisting of C4 to C20 linear alkylenes, C4 to C22 divalent ethers, and C4 to C22 branched alkylene;
the silane group comprises a silicon atom bonded to each of an R1, an R2, and an R3, wherein each R1, R2, and R3 are independently selected from hydrogen, hydroxide, C1 to C10 alkoxys, C6 to C30 aryloxys, C7 to C30 arylalkyloxys, and C1 to C10 alkylamines, wherein any 2- or more groups can form an aliphatic or aromatic cyclic structure that includes the silicon atom; and
PO is a polyolefin having a Mw of at least 400 g/mole; and
“n” is an integer within the range from 1 to 30;
with the proviso that at least two of R1, R2, and R3 is selected from functional polyolefin moieties having the following structure:

wherein the functional polyolefin moiety is covalently bonded to the silane group via any one or more of R1′, R2′, or R3′; and where any other one or more of R1′, R2′, or R3′ is independently selected from hydroxide, C1 to C10 alkoxys, C6 to C30 aryloxys, C7 to C30 arylalkyloxys, and C1 to C10 alkylamines, wherein any 2- or more groups can form an aliphatic or aromatic cyclic structure that includes the silicon atom functional polyolefin moieties;
wherein the star-structured functional polyolefins have a branching number within the range of 3 to 30.

2. The star-structured functional polyolefins of claim 1 , wherein R4 is a hydroxyl group and Nu is nitrogen.

3. The star-structured functional polyolefins of claim 1 , wherein at least one of R1′, R2′, and R3′ is selected from functional polyolefin moieties.

4. The star-structured functional polyolefins of claim 1 , wherein the polyolefin bound to at least one nucleophile-containing silane anywhere along the polyolefin chain is selected from the group consisting of polybutadienes, polyisoprenes, isobutylene-isoprene copolymer, halogenated isobutylene-isoprene copolymer, isobutylene-p-methylstyrene copolymer, halogenated isobutylene-p-methylstyrene copolymer, ethylene-propylene-diene terpolymers, vinyl/vinylidene-terminated polypropylenes, vinyl/vinylidene-terminated polyethylenes, and vinyl/vinylidene-terminated ethylene-propylene copolymers.

5. The star-structured functional polyolefins of claim 1 , wherein X is a C4 to C20 linear alkylene, or a C4 to C20 branched alkylene.

6. The star-structured functional polyolefins of claim 1 , wherein the weight loss after one week at 120° C. is less than 5% of its original Mw.

7. A polyolefin blend comprising a polyolefin and within the range from 0.1 wt % to 20 wt % of at least one star-structured functional polyolefin, based on the weight of the blend, of claim 1 .

8. A tire tread formulation comprising the star-structured functional polyolefins of claim 1 , at least one elastomer and silica.

9. A method of forming star-structured functional polyolefins comprising combining:
a) at least one polyolefin comprising at least one unsaturation at one or both of the chain ends and/or inside the chain; and
b) at least one nucleophile-containing silane to form a functional polyolefin, wherein the nucleophile-containing silane comprises a nucleophilic atom selected from the group consisting of nitrogen, oxygen, sulfur, or phosphorous;
wherein the at least one site of unsaturation forms a covalent bond with the nucleophilic atom of the nucleophile-containing silane;

c) effecting condensation between at least three functional polyolefins to form star-structured functional polyolefins having a branching number within the range of 3 to 30.

10. The method of claim 9 , wherein the polyolefin with at least one unsaturation is selected from the group consisting of polybutadienes, polyisoprenes, isobutylene-isoprene copolymer, halogenated isobutylene-isoprene copolymer, isobutylene-p-methylstyrene copolymer, halogenated isobutylene-p-methylstyrene copolymer, ethylene-propylene-diene terpolymers, vinyl/vinylidene-terminated polypropylenes, vinyl/vinylidene-terminated polyethylenes, and vinyl/vinylidene-terminated ethylene-propylene copolymers.

11. The method of claim 9 , wherein condensation is effected by refluxing the functionalized polyolefin in solvent for at least 2 hours.

12. The method of claim 9 , wherein the polyolefin comprising at least one unsaturation is a vinyl/vinylidene terminated polyolefin.

13. The method of claim 12 , wherein all reaction steps occur together.

14. The method of claim 12 , having a branching number within the range from 5 to 30.

15. The method of claim 9 , wherein the nucleophile-containing silane is selected from compounds having the following structure:

wherein each R1, R2, and R3 are independently selected from the group consisting of hydrogen, hydroxide, C1 to C10 alkoxys, C6 to C30 aryloxys, C7 to C30 arylalkyloxys, and C1 to C10 alkylamines, wherein any 2- or more groups can form an aliphatic or aromatic cyclic structure with that includes the silicon atom;
Nu is the nucleophilic atom;
X is at least a divalent group selected from the group consisting of C4 to C20 linear alkylene, C4 to C22 divalent ether, and C4 to C22 or C40 branched alkylene;
R5 and R6 are independently selected from the group consisting of hydrogen, C1 to C10 alkyls, C1 to C10 aminoalkyls, C6 to C20 aryls, C7 to C22 alkylaryls, C7 to C22 aminoaryls, and C7 to C22 arylalkyls; and
silane group wherein any one of R1, R2 or R3 may form a 5 to 10 membered alkylene or aminoalkylene ring with Nu.

16. The method of claim 9 , wherein the combining occurs under hydroaminoalkylation conditions.

17. The method of claim 9 , further comprising treating the polyolefin with at least one nucleophile-reactive group by direct epoxidation and/or hydrosilylation prior to combining said polyolefin with the least one nucleophile-containing silane.

18. The method of claim 9 , further comprising combining the star-structured functional polyolefins with at least one elastomer and silica to form a tire tread composition.

19. The method of claim 9 , wherein the weight loss of the star-structured functional polyolefins after one week at 120° C. is less than 5% of its original Mw.

20. A method of tailoring the branching number of a silane-functionalized polyolefin of claim 9 , comprising choosing the structure of the nucleophile-containing silane and/or the conditions under which the reaction is performed.

21. The star-structured functional polyolefins of claim 1 , wherein

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Yang Yong
• Tsou Andy H
• Slaughter Kimari T M

Classifications

• C08F8/30

  Introducing nitrogen atoms or nitrogen-containing groups · CPC title

• B60C1/0016

  Compositions of the tread · CPC title

• C08G77/48

  in which at least two but not all the silicon atoms are connected by linkages other than oxygen atoms (C08G77/42 takes precedence) · CPC title

• C08G81/00

  Macromolecular compounds obtained by interreacting polymers in the absence of monomers, e.g. block polymers (involving only carbon-to-carbon unsaturated bond reactions C08F299/00 {; polyester-amides C08G69/44; polyester-imides C08G73/16; polyamides-imides C08G73/14; block- or graft polymers containing polysiloxane sequences C08G77/42}) · CPC title

• C08G81/021

  Block or graft polymers containing only sequences of polymers of C08C or C08F · CPC title