# US 5,705,549 A · Rubber compositions

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- Number: US 5,705,549 A
- Document ID: US5705549A
- Status: Granted
- Kind: A
- Application number: 08/631,985
- Filed: 1996-04-15
- Granted: 1998-01-06
- Earliest claimed: 1995-04-17
- Assignees: Bridgestone Corporation
- Inventors: Masahiro Hojo
- Web page: https://patentgrep.com/patent/US5705549A

## CPC

- C08K 5/25: Carboxylic acid hydrazides
- C08L 21/00: Compositions of unspecified rubbers
- Y02T 10/86: Optimisation of rolling resistance, e.g. weight reduction
- C08K: Use of inorganic or non-macromolecular organic substances as compounding ingredients (paints, inks, varnishes, dyes, polishes, adhesives C09)
- C08L: COMPOSITIONS OF MACROMOLECULAR COMPOUNDS (compositions based on polymerisable monomers C08F, C08G; artificial filaments or fibres D01F; textile treating compositions D06)
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A rubber composition comprises a particular copolymer containing isobutylene unit, a paramethylstyrene unit and a parabromomethylstyrene unit; natural rubber and/or diene synthetic rubber; carbon black; and at least one hydrazide compound, and has a low value of tan .delta. at 60.degree. C. with maintaining tan .delta. at 0.degree. C. at a high level.

## Claims

### Claim 1

A rubber composition comprising (1) 10-50 parts by weight of a copolymer containing isobutylene unit, a paramethylstyrene unit and a parabromomethylstyrene unit; (2) (100-Q) parts by weight of natural rubber and/or diene synthetic rubber when the amount of the copolymer of the above item (1) is Q; (3) 20-150 parts by weight of carbon black; and (4) 0.1-5.0 parts by weight of at least one hydrazide compound represented by the following general formulae (I), (II) and (III): ##STR11## wherein A is a bivalent group obtained from an aromatic ring, a substituted or nonsubstituted hydantoin ring, or a saturated or unsaturated straight-chain hydrocarbon having a carbon number of 1-18, B is a bivalent aromatic hydrocarbon group, X is a hydroxyl group or an amino group, and Y is a pyridyl group or a hydrazino group.

### Claim 2 (depends on 1)

A rubber composition according to claim 1, wherein a total content of paramethylstyrene unit and parabromomethylstyrene unit in the copolymer is 0.5-20% by weight, and a content of parabromomethylstyrene unit as an atomic content of bromine is 0.1-7.5% by weight.

### Claim 3 (depends on 1)

A rubber composition according to claim 1, wherein the hydrazide compound is at least one compound selected from the group consisting of phthalic acid dihydrazide, terephthalic acid dihyrdazide, isophthalic acid dihydrazide, succinic acid dihydrazide, adipic acid dihydrazide, azelaic acid dihydrazide, sebacic acid dihydrazide, eicosane diacid dihydrazide, 7,11-octadecadiene-1,18-dicarbohydrazide, oxalic acid dihydrazide, anthraniloylhydrazide, salicylic acid hydrazide, 4-hydroxybenzoic acid hydrazide, 2-hydroxy-3-naphthoic acid hydrazide, isonicotinic acid hydrazide and carbodihydrazide.

### Claim 4 (depends on 3)

A rubber composition according to claim 3, wherein the hydrazide compound is 2-hydroxy-3-naphthoic acid hydrazide, isophthalic acid dihyrazide or isonicotinic acid hydrazide.

### Claim 5 (depends on 4)

A rubber composition according to claim 4, wherein the hydrazide compound is 2-hydroxy-3-naphthoic acid hydrazide.

### Claim 6 (depends on 1)

A rubber composition according to claim 1, wherein the diene synthetic rubber is at least one rubber selected from the group consisting of cis-1,4-polyisoprene, styrene-butadiene copolymer, low cis-1,4-polybutadiene, high cis-1,4-polybutadiene, ethylene-propylene-diene terpolymer, chloroprene, halogenated butyl rubber and acrylonitrile-butadiene rubber.