Diene rubber

Details Diene rubber Diene rubber

1998-05-28

2001-04-03

Hamilton, Cynthia (Department: 1752)

Synthetic resins or natural rubbers -- part of the class 520 ser

Synthetic resins

Polymers from only ethylenic monomers or processes of...

C526S310000

Reexamination Certificate

active

06211321

ABSTRACT:

TECHNICAL FIELD
This invention relates to a diene rubber which, when silica is incorporated thereinto as a reinforcing agent, can yield a vulcanized rubber having improved heat build-up, tensile strength and abrasion resistance, and processes for preparing the same. This invention also relates to rubber compositions containing a rubber component comprising the diene rubber and a reinforcing agent.
BACKGROUND ART
In recent years, as growing importance is attached to resource saving and environmental protection, the demand for a reduction in the fuel consumption of automobiles has become increasingly stronger. Also for automobile tires, it is desired to reduce their rolling resistance and thereby contribute to a reduction in fuel consumption. In order to reduce the rolling resistance of tires, it is common practice to use a rubber material which can yield a vulcanized rubber showing a low degree of heat build-up.
Conventionally, it has been proposed to reduce heat build-up by using, as the rubber material for tires, a rubber composition comprising a diene rubber into which, in place of carbon black, silica is incorporated as a reinforcing agent. However, as compared with carbon black-filled rubber compositions, such silica-filled rubber compositions have the disadvantage that they fail to achieve sufficient abrasion resistance and tensile strength. One of the causes therefor is believed to be that silica has a lower affinity for diene rubbers than carbon black and hence fails to exhibit a sufficient reinforcing effect.
Conventionally, in order to enhance the affinity of silica for diene rubbers, the use of a diene rubber into which a substituent group having an affinity for silica has been introduced is being investigated. For example, diene rubbers having a tertiary amino group introduced thereinto (Japanese Patent Laid-Open No. 101344/'89) have been proposed for diene rubbers formed by emulsion polymerization; and diene rubbers having introduced thereinto an alkylsilyl group (Japanese Patent Laid-Open No. 188501/'89), a halogenated silyl group (Japanese Patent Laid-Open No. 230286/'93) or a substituted amino group (Japanese Patent Laid-Open No. 22940/'89) have been proposed for diene rubbers formed by anionic polymerization. However, these diene rubbers having a substituent group introduced thereinto fail to show sufficient improvements in heat build-up, tensile strength and abrasion resistance.
On the other hand, in order to improve green strength, Japanese Patent Publication No. 41282/'83 discloses a rubber composition comprising the reaction product of a tertiary amino-containing butadiene-styrene copolymer with a dihalide [e.g., 4,4′-bis(bromoacetyl)diphenylmethane (hereinafter abbreviated as BADE)], and carbon black. However, if this reaction product is blended with silica, the resulting composition shows an improvement in tensile strength, but fails to show an improvement in heat build-up which must be characteristic of a silica-filled material. Moreover, this composition also has the disadvantage that its properties such as abrasion resistance are not satisfactory.
An object of the present invention is to provide a diene rubber which, when silica is incorporated thereinto as a reinforcing agent, can yield a vulcanized rubber that shows an improvement in heat build-up serving as an indication of rolling resistance and that has substantially the same tensile strength and abrasion resistance as when carbon black is incorporated thereinto, as well as processes for preparing the same.
Another object of the present invention is to provide a rubber containing a diene rubber and a reinforcing agent, and capable of yielding a vulcanized rubber which is excellent in heat build-up, tensile strength and abrasion resistance.
DISCLOSURE OF THE INVENTION
The present inventors have made intensive investigations with a view to overcoming the above-described problems of the prior art. As a result, it has now been discovered that a rubber composition capable of yielding a vulcanized rubber having sufficiently excellent build-up, tensile strength and abrasion resistance can be obtained by using, as a rubber component, a diene rubber containing a tertiary amino group which is at least partially quaternized with a hydrocarbon radical (that may hereinafter be referred to briefly as the quaternary ammonium-containing diene rubber) and that the quaternary ammonium-containing diene rubber can be efficiently prepared by reacting a diene rubber having therein a copolymerized tertiary amino-containing vinyl monomer with a monohalogenated hydrocarbon or by reacting a diene rubber having therein a copolymerized halogen-containing vinyl monomer with a tertiary amine. The present invention has been completed on the basis of this discovery.
Thus, the present invention provides a diene rubber composed of 40 to 99.99% by weight of combined units of a conjugated diene monomer, 0 to 50% by weight of combined units of an aromatic vinyl monomer, and 0.01 to 20% by weight of combined units of a vinyl monomer containing a tertiary amino group which is at least partially quaternized with a hydrocarbon group, and having a Mooney viscosity (ML
1+4
, 100° C.) of 10 to 200, wherein the tertiary amino-containing vinyl monomer is a compound of the formula
CH
2
═CR
11
—A
2
—NR
12
R
13
where R
11
is a hydrogen atom or a lower alkyl group, R
12
and R
13
are each an alkyl group, an aryl group or an aralkyl group, A
2
is an alkylene group, an arylene group, an arylene-alkylene group, an alkylene-arylene group, or a linking group of the general formula —C(═O)—M—R
14
— (in which M is an oxy group or an NH group, and R
14
is an alkylene group, an arylene group, an arylene-alkylene group or an alkylene-arylene group), and R
12
or R
13
may be combined with A
2
to form a heterocyclic ring, the quaternized tertiary amino-containing vinyl monomer is a compound of the formula
CH
2
═CR
1
—A
1
—N
+
R
2
R
3
R
4
.X
1
−
where R
1
is a hydrogen atom or a lower alkyl group, R
2
, R
3
and R
4
are each an alkyl group, an aryl group or an aralkyl group, A
1
is an alkylene group, an arylene group, an arylene-alkylene group, an alkylene-arylene group, or a linking group of the general formula —C(═O)—M—R
5
— (in which M is an oxy group or an NH group, and R
5
is an alkylene group, an arylene group, an arylene-alkylene group or an alkylene-arylene group), R
2
or R
3
may be combined with A
1
to form a heterocyclic ring, and X
1
is a halogen atom.
Moreover, the present invention also provides a process for preparing the aforesaid diene rubber which comprises copolymerizing a conjugated diene, or a conjugated diene and an aromatic vinyl, with a tertiary amino-containing vinyl monomer and subsequently reacting the resulting polymer with a monohalogenated hydrocarbon.
Furthermore, the present invention also provides a process for preparing the aforesaid diene rubber which comprises copolymerizing a conjugated diene, or a conjugated diene and an aromatic vinyl, with a halogen-containing vinyl monomer and subsequently reacting the resulting polymer with a tertiary amine.
In addition, the present invention also provides a rubber composition containing a rubber component comprising the aforesaid diene rubber, and a reinforcing agent.
Quaternary Ammonium-containing Diene Rubber
The diene rubber of the present invention is composed of combined units of a conjugated diene monomer and combined units of a tertiary amino-containing vinyl monomer which is at least partially quaternized with a hydrocarbon group (i.e., combined units of a quaternary ammonium-containing vinyl monomer and combined units of a tertiary amino-containing vinyl monomer; hereinafter referred to as “combined units of an at least partially quaternized tertiary amino-containing vinyl monomer”), and contains combined units of an aromatic vinyl monomer as required. Examples of the conjugated diene include 1,3-butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene and 1

Affiliated with

Also associated with

Rating

Diene rubber does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Diene rubber, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Diene rubber will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2502044