Pneumatic tire

Patent metadata

Field	Value
Publication number	US-2016159157-A1
Application number	US-201414564587-A
Country	US
Kind code	A1
Filing date	Dec 9, 2014
Priority date	Dec 9, 2014
Publication date	Jun 9, 2016
Grant date	—

Abstract

The present invention is directed to a pneumatic tire having a tread comprising a radially outer cap layer and radially inner cap layer underlying the outer cap layer; the outer cap layer comprising a vulcanizable rubber composition comprising, based on 100 parts by weight of elastomer (phr), from about 50 to about 90 phr of a solution polymerized styrene-butadiene rubber having a glass transition temperature (Tg) ranging from −65° C. to −55° C. and functionalized with an alkoxysilane group and at least one functional group selected from the group consisting of primary amines and thiols; from about 50 to about 10 phr of polybutadiene having a cis 1,4 content greater than 95 percent and a Tg ranging from −80 to −110° C.; from 30 to 80 phr of a combination of a resin having a Tg of at least 30° C. and an oil, wherein the weight ratio of resin to oil is greater than 1; and the inner cap layer comprising a vulcanizable rubber composition comprising: from about 50 to about 90 phr of a solution polymerized styrene-butadiene rubber functionalized with an alkoxysilane group and at least one functional group selected from the group consisting of primary amines and thiols; from about 50 to about 10 phr of polybutadiene having a cis 1,4 content greater than 95 percent and a Tg ranging from −80 to −110° C.; and from 30 to 50 phr of an oil, and essentially free of a resin.

First claim

What is claimed is:

1 . a pneumatic tire having a tread comprising a radially outer cap layer and radially inner cap layer underlying the outer cap layer;
the outer cap layer comprising a vulcanizable rubber composition comprising, based on 100 parts by weight of elastomer (phr), (A) from about 50 to about 90 phr of a solution polymerized styrene-butadiene rubber having a glass transition temperature (Tg) ranging from −65° C. to −55° C. and functionalized with an alkoxysilane group and at least one functional group selected from the group consisting of primary amines and thiols; (B) from about 50 to about 10 phr of polybutadiene having a cis 1,4 content greater than 95 percent and a Tg ranging from −80 to −110° C.; (C) from 30 to 80 phr of a combination of a resin having a Tg of at least 30° C. and an oil, wherein the weight ratio of resin to oil is greater than 1; the inner cap layer comprising a vulcanizable rubber composition comprising: (i) from about 50 to about 90 phr of a solution polymerized styrene-butadiene rubber functionalized with an alkoxysilane group and at least one functional group selected from the group consisting of primary amines and thiols; (ii) from about 50 to about 10 phr of polybutadiene having a cis 1,4 content greater than 95 percent and a Tg ranging from −80 to −110° C.; (iii) from 20 to 50 phr of an oil, and essentially free of a resin.

2 . The pneumatic tire of claim 1 , wherein the combination of resin and oil in the outer cap layer is present in an amount ranging from 30 to 50 phr.

3 . The pneumatic tire of claim 1 , wherein the combination of resin and oil in the outer cap layer is present in an amount ranging from 50 to 80 phr.

4 . The pneumatic tire of claim 1 , wherein the amount of oil in the outer cap layer ranges from 5 to 25 phr, and the amount of resin ranges from 25 to 45 phr.

5 . The pneumatic tire of claim 1 , wherein the amount of oil in the outer cap layer ranges from 5 to 20 phr, and the amount of resin ranges from 45 to 75 phr.

6 . The pneumatic tire of claim 1 , wherein the weight ratio of resin to oil in the outer cap layer is greater than 3.

7 . The pneumatic tire of claim 1 , wherein the weight ratio of resin to oil in the outer cap layer is greater than 6.

8 . The pneumatic tire of claim 1 , wherein the resin is selected from the group consisting of hydrocarbon resins, phenol/acetylene resins, terpene-phenol resins, rosin derived resins and mixtures thereof.

9 . The pneumatic tire of claim 1 , wherein the resin is derived from styrene and alphamethylstyrene.

10 . The pneumatic tire of claim 1 , wherein the resin is a terpene-phenol resin.

11 . The pneumatic tire of claim 1 , wherein the solution polymerized styrene-butadiene rubber functionalized with an alkoxysilane group and a primary amine group, and is represented by the formula (1) or (2)

wherein P is a (co)polymer chain of a conjugated diolefin or a conjugated diolefin and an aromatic vinyl compound, R 1 is an alkylene group having 1 to 12 carbon atoms, R 2 and R 3 are each independently an alkyl group having 1 to 20 carbon atoms, an allyl group or an aryl group, n is an integer of 1 or 2, m is an integer of 1 or 2, and k is an integer of 1 or 2, with the proviso that n+m+k is an integer of 3 or 4,

wherein P, R 1 , R 2 and R 3 have the same definitions as give for the above-mentioned formula (1), j is an integer of 1 to 3, and h is an integer of 1 to 3, with the provision that j+h is an integer of 2 to 4.

12 . The pneumatic tire of claim 1 , wherein the solution polymerized styrene-butadiene rubber is functionalized with an alkoxysilane group and a primary amine group comprises the reaction product of a living polymer chain and a terminating agent of the formula
RN—(CH 2 ) X —Si—(OR′) 3 ,   I

wherein R in combination with the nitrogen (N) atom is a protected amine group which upon appropriate post-treatment yields a primary amine, R′ represents a group having 1 to 18 carbon atoms selected from an alkyl, a cycloalkyl, an allyl, or an aryl; and X is an integer from 1 to 20.

13 . The pneumatic tire of claim 1 wherein the solution polymerized styrene-butadiene rubber is functionalized with an alkoxysilane group and a thiol, and comprises the reaction product of a living anionic polymer and a silane-sulfide modifier represented by the formula
(R 4 O) x R 4 y Si—R 5 —S—SiR 4 3

wherein Si is silicon; S is sulfur; O is oxygen; x is an integer selected from 1, 2 and 3; y is an integer selected from 0, 1, and 2; x+y=3; R 4 is the same or different and is (C 1 -C 16 ) alkyl; and R′ is aryl, and alkyl aryl, or (C 1 -C 16 ) alkyl.

14 . The pneumatic tire of claim 1 , wherein said vulcanizable rubber composition of the outer cap layer comprises about 70 to about 160 phr of silica.

Assignees

• Goodyear Tire & Rubber

Inventors

• Jacoby Claude Charles
• Mejia Luisa Fernanda Munoz
• Isitman Nihat Ali

Classifications

• B60C11/005 Primary

  with cap and base layers · CPC title

• B60C1/0016

  Compositions of the tread · CPC title

• B60C5/00

  Inflatable pneumatic tyres or inner tubes (B60C1/00, B60C9/00 - B60C17/00 take precedence) · CPC title

• C08L15/00

  Compositions of rubber derivatives (C08L11/00, C08L13/00 take precedence) · CPC title

• B60C1/00

  Tyres characterised by the chemical composition or the physical arrangement or mixture of the composition · CPC title