Propylene-Based Polymer Additives for Improved Tire Tread Performance

Patent metadata

Field	Value
Publication number	US-2017292013-A1
Application number	US-201515507400-A
Country	US
Kind code	A1
Filing date	Aug 31, 2015
Priority date	Sep 30, 2014
Publication date	Oct 12, 2017
Grant date	—

Abstract

A tire tread composition is disclosed. The tire tread composition includes components, by weight of the composition, within the range from: 5 to 75 wt % of a diene elastomer; 0 to 40 wt % of processing oil; 20 to 80 wt % of filler; a curative agent; and 5 to 30 wt % of a propylene-ethylene-diene terpolymer containing from 2 wt % to 40 wt % of ethylene and/or C 4 -C 20 α-olefins derived units, from 0.5 to 10 wt % of diene derived units, and having a heat of fusion, as determined by DSC, of from 0 J/g to 80 J/g.

First claim

1 . A tire tread composition comprising components, by weight of the composition, within the range from:
5 to 75 wt % of a diene elastomer; 0 to 40 wt % of processing oil; 20 to 80 wt % of filler; a curative agent; and 5 to 30 wt % of a propylene-ethylene-diene terpolymer containing from 2 to 40 wt % of ethylene and/or C 4 -C 20 α-olefins derived units, from 0.5 to 10 wt % of diene derived units, and having a heat of fusion, as determined by DSC, of from 0 J/g to 80 J/g.

2 . The tire tread composition of claim 1 , wherein the filler is a silica-based filler.

3 . The tire tread composition of claim 1 , wherein the filler is a carbon black filler.

4 . The tire tread composition of claim 1 , wherein the filler is blend of silica-based filler and a carbon black filler.

5 . The tire tread composition of claim 1 , wherein the propylene-ethylene-diene terpolymer contains from 0.5 to 10 wt % ethylidene norbornene.

6 . The tire tread composition of claim 1 , wherein the propylene-ethylene-diene terpolymer contains from 2 wt % to 20 wt % ethylene.

7 . The tire tread composition of claim 1 , wherein the propylene-ethylene-diene terpolymer contains 60 wt % to 95 wt % propylene.

8 . The tire tread composition of claim 1 , wherein the Tg (° C.) of the tire tread composition is from 0 to −60.

9 . The tire tread composition of claim 1 , wherein the melt flow rate (MFR) at 2.16 kg weight at 230° C. of the propylene-ethylene-diene terpolymer is from 0.2 to 10 g/10 min.

10 . The tire tread composition of claim 1 , wherein the diene elastomer is a styrenic copolymer, a polybutadiene, natural rubber, a polyisoprene, a butadiene copolymer, an isoprene copolymer or blends thereof.

11 . A tire tread comprising the cured reaction product of the components, by weight of the composition, within the range from:
5 to 75 wt % of a diene elastomer; 0 to 40 wt % of processing oil; 20 to 80 wt % of filler; a curative agent; and 5 to 30 wt % of a propylene-ethylene-diene terpolymer containing from 2 to 40 wt % of ethylene and/or C 4 -C 20 α-olefins derived units, from 0.5 to 10 wt % of diene derived units, and having a heat of fusion, as determined by DSC, of from 0 J/g to 80 J/g.

12 . The tire tread composition of claim 11 , wherein the filler is a silica-based filler.

13 . The tire tread composition of claim 11 , wherein the filler is a carbon black filler.

14 . The tire tread composition of claim 11 , wherein the filler is blend of silica-based filler and a carbon black filler.

15 . The tire tread composition of claim 11 , wherein the propylene-ethylene-diene terpolymer contains from 0.5 to 10 wt % ethylidene norbornene.

16 . The tire tread composition of claim 11 , wherein the propylene-ethylene-diene terpolymer contains from 2 wt % to 20 wt % ethylene.

17 . The tire tread composition of claim 11 , wherein the propylene-ethylene-diene terpolymer contains 60 wt % to 95 wt % propylene.

18 . The tire tread composition of claim 11 , wherein the Tg (° C.) of the tire tread composition is from 0 to −60.

19 . The tire tread composition of claim 11 , wherein the melt flow rate (MFR) at 2.16 kg weight at 230° C. is from 0.2 to 10 g/10 min.

20 . The tire tread composition of claim 11 , wherein the diene elastomer is a styrenic copolymer, a polybutadiene, natural rubber, a polyisoprene, a butadiene copolymer, an isoprene copolymer or blends thereof.

21 . A method of balancing the wet traction performance and rolling resistance in a tire tread comprising:
combining at least a filler, a diene-elastomer, and a curative agent with one or more propylene-ethylene-diene terpolymers to form a tire tread; wherein the propylene-ethylene-diene terpolymer containing from 2 wt % to 40 wt % of ethylene and/or C 4 -C 20 α-olefins derived units, from 0.5 to 10 wt % of diene derived units, and having a heat of fusion, as determined by DSC, of from 0 J/g to 80 J/g; effecting a cure of the components to form a tire tread; and wherein the level of the propylene-ethylene-diene terpolymer(s) relative to the other components, and its comonomer content, can be varied to improve the balance of wet traction and rolling resistance of a tire tread.

22 . The method of claim 21 , wherein the filler is a silica-based filler.

23 . The method of claim 21 , comprising one propylene-ethylene-diene terpolymer; and wherein the amount of the propylene-ethylene-diene terpolymer is varied within a range from 5 wt % to 30 wt %.

24 . The method of claim 21 , wherein the level of ethylene and/or C 4 -C 20 α-olefins derived units in the one or more propylene-ethylene-diene terpolymer(s) is varied within a range from 2 wt % to 40 wt %; and the level of diene (e.g., ethylidene norbornenes) varied within a range from 0.5 to 10 wt %.

25 . The method of claim 24 , wherein the propylene-ethylene-diene terpolymer(s) comprise a blend of different propylene-ethylene-diene terpolymers in varying amounts, the total amount within a range from 5 wt % to 30 wt %.

Assignees

• Exxonmobil Chemical Patents Inc

Inventors

• Blok Edward J
• Dias Anthony J
• Jacob Sunny
• Stewart Lan C
• Yang Yong
• Zhang Jingwen

Classifications

• C08L2312/00

  Crosslinking · CPC title

• C08L9/00 Primary

  Compositions of homopolymers or copolymers of conjugated diene hydrocarbons · CPC title

• C08L2205/06

  having improved processability or containing aids for moulding methods · CPC title

• C08L7/00

  Compositions of natural rubber · CPC title

• C08L9/06 Primary

  Copolymers with styrene · CPC title