Rubber Compositions Comprising Metal Carboxylates And Processes For Making The Same

Patent metadata

Field	Value
Publication number	US-2015274939-A1
Application number	US-201314440161-A
Country	US
Kind code	A1
Filing date	Nov 4, 2013
Priority date	Nov 2, 2012
Publication date	Oct 1, 2015
Grant date	—

Abstract

The present disclosure provides reinforcing filler-containing rubber compositions suitable for use in tires, and particularly in tire treads. These rubber compositions comprise a metal carboxylate. The metal carboxylate provides improved processability to the rubber compositions in the form of a reduced Mooney viscosity. In certain exemplary embodiments, these rubber compositions containing the metal carboxylate also have an enhanced elastic modulus (also referred to as the G′). Further, in certain of the enhanced elastic modulus embodiments, the rubber compositions containing the metal carboxylate also have decreased hysteresis loss.

First claim

What is claimed is:

1 - 26 . (canceled)

27 . A vulcanizable rubber composition comprising:
(a) a conjugated diene polymer or copolymer component; (b) a reinforcing filler component comprising at least one of:
(i) carbon black,
(ii) silica and a silane coupling agent, and
(iii) silica; and
(c) from 0.5 to 40 phr of at least one metal carboxylate represented by the formula:
(RCOO) p M (p+n)+ (OH) n ,
wherein:
R is a hydrocarbyl group having from 1 to 25 carbon atoms and optionally containing a heteroatom selected from a halogen atom, nitrogen, oxygen, and sulfur,
M is selected from the group consisting of aluminum, barium, cadmium, calcium, cobalt, iron, lithium, magnesium, sodium, tin, zinc, and zirconium, and
p+n equals the valency of M, and each of n and p are independently selected from an integer ranging from 0 to (p+n).

28 . The vulcanizable rubber composition of claim 27 , wherein M comprise zinc or aluminum.

29 . The vulcanizable rubber composition of claim 27 , wherein M comprises aluminum.

30 . The vulcanizable rubber composition of claim 27 , wherein at least one of the following is met:
a. the reinforcing filler comprises no more than 10 phr of carbon black; or b. the reinforcing filler comprises no more than 1 phr of silane coupling agent.

31 . The vulcanizable rubber composition of claim 27 , wherein the at least one metal carboxylate comprises at least one of: dihydroxyaluminum stearate, hydroxyaluminum distearate, aluminum tristearate, aluminum tri(n-decanoate), hydroxyaluminum di(2-ethylhexanoate), aluminum tri(n-octanoate), aluminum tri(5-phenylbutanoate), aluminum trilinoleate, zinc distearate, barium distearate, calcium distearate, magnesium distearate, sodium monostearate, or lithium monostearate.

32 . The vulcanizable rubber composition of claim 27 , wherein when unvulcanized, the Mooney viscosity (ML 1+4 at 130° C.) of the composition is less than that of a comparative rubber composition, wherein the comparative rubber composition is the same except that the comparative rubber composition does not contain the at least one metal carboxylate.

33 . The vulcanizable rubber composition of claim 27 , wherein the reinforcing filler component comprises silica and silane coupling agent and the silane coupling agent is present in an amount from 0.01 to 25% by weight of the silica.

34 . The vulcanizable rubber composition of claim 27 , wherein M comprises zinc and the reinforcing filler comprises carbon black.

35 . The vulcanizable rubber composition of claim 27 , wherein when vulcanized, the G′ (at 50° C., 5% strain, 15 Hz) of the composition is enhanced as compared to that of a comparative rubber composition, wherein the comparative rubber composition is the same except that the comparative rubber composition does not contain the at least one metal carboxylate.

36 . The vulcanizable rubber composition of claim 35 , wherein when vulcanized, the rubber composition has a G′ (at 50° C., 5% strain, 15 Hz) that is at least 90% of that of a comparative rubber composition, wherein the comparative rubber composition is the same except that the comparative rubber composition does not contain the at least one metal carboxylate.

37 . The vulcanizable rubber composition of claim 35 , wherein when vulcanized, the hysteresis loss (at 50° C., 5% strain, 15 Hz) of the composition is the same or less as compared to that of a comparative rubber composition, wherein the comparative rubber composition is the same except that the comparative rubber composition does not contain the at least one metal carboxylate.

38 . The vulcanizable rubber composition of claim 27 , wherein R has from 4 to 20 carbon atoms.

39 . The vulcanizable rubber composition of claim 27 , wherein the at least one metal carboxylate comprises at least one of an aluminum tricarboxylate, a dihydroxyaluminum carboxylate, or a hydroxyaluminum dicarboxylate.

40 . The vulcanizable rubber composition of claim 27 , wherein the at least one metal carboxylate comprises at least one of dihydroxyaluminum stearate, hydroxyaluminum distearate, aluminum tristearate, aluminum tri(n-decanoate), hydroxyaluminum di(2-ethylhexanoate), aluminum tri(n-octanoate), aluminum tri(5-phenylbutanoate), or aluminum trilinoleate.

41 . The vulcanizable rubber composition of claim 27 , wherein the composition comprises 5 to 200 phr of the reinforcing filler component.

42 . The vulcanizable rubber composition of claim 27 , wherein the at least one metal carboxylate is present in an amount of 0.5 to 20 phr.

43 . The vulcanizable rubber composition of claim 27 , wherein the conjugated diene polymer or copolymer component includes at least one silica-reactive functionalized conjugated diene polymer or copolymer.

44 . The vulcanizable rubber composition of claim 27 , wherein the composition further comprises a curative component, and the curative component includes at least one of: a vulcanizing agent, a vulcanizing accelerator, a vulcanizing activator, a vulcanizing inhibitor, and an anti-scorching agent.

45 . A process for preparing a rubber composition, comprising:
(1) mixing a master-batch comprising
(a) a conjugated diene polymer or copolymer component;
(b) a reinforcing filler component comprising at least one of:
(i) carbon black,
(ii) silica and a silane coupling agent, and
(iii) silica; and

(c) at least one metal carboxylate represented by the formula:
(RCOO) p M (p+n)+ (OH) n ,
wherein:
R is a hydrocarbyl group having from 1 to 25 carbon atoms and optionally containing a heteroatom selected from a halogen atom, nitrogen, oxygen, and sulfur,
M is selected from the group consisting of aluminum, barium, cadmium, calcium, cobalt, iron, lithium, magnesium, sodium, tin, zinc, and zirconium, and
p+n equals the valency of M, and each of n and p are independently selected from an integer ranging from 0 to (p+n);

(2) mixing a final batch comprising
(a) a curative component including at least one of: a vulcanizing agent, a vulcanizing accelerator, a vulcanizing activator, a vulcanizing inhibitor, and an anti-scorching agent, and
(b) the master-batch; and
(3) vulcanizing the final batch.

46 . The process claim 45 , wherein the process further comprises heating the master-batch to a temperature sufficient to melt at least a portion of the metal carboxylate present prior to the step of mixing the final batch.

47 . A vulcanizable rubber composition comprising:
(a) a conjugated diene polymer or copolymer component including at least one of styrene-butadiene rubber, polybutadiene, natural rubber, or polyisoprene; (b) 5-200 phr of a reinforcing filler component comprising at least one of:
(i) carbon black,
(ii) silica and a silane coupling agent, and
(iii) silica; and
(c) from 0.5 to 20 phr of at least one metal carboxylate represented by the formula:
(RCOO) p M (p+n)+ (OH) n , wherein:
R is a hydrocarbyl group having from 1 to 25 carbon atoms and optionally containing a heteroatom selected from a halogen atom, nitrogen, oxygen, and sulfur,
M is selected from the group consisting of aluminum, barium, cadmium, calcium, cobalt, iron, lithium, magnesium, sodium, tin, zinc, and zirconium, and
p+n equals the valency of M, and each of n and p are independently selected from an integer ranging from 0 to (p+n).

Assignees

• Chen Yaohong
• Bridgestone Corp

Inventors

• Chen Yaohong
• Uchiyama Toshihiro
• Gozen Arif O
• Rackaitis Mindaugas

Classifications

• C08K3/04

  Carbon · CPC title

• C08K5/098

  Metal salts of carboxylic acids · CPC title

• C08K5/5415

  containing at least one Si—O bond · CPC title

• B60C1/0016

  Compositions of the tread · CPC title

• C08K5/548

  containing sulfur {(C08K5/5477 takes precedence)} · CPC title