| 摘要 |
Visco-elastic tyre balancing compositions comprising 1) 85 to 97% by weight of a glycol ether component comprising one or more ethylene/propylene glycol copolymer ethers of the general formula (I) or the general (II) or mixtures thereof R-O{[CH(CH)CH-O-][CH-CH-O-]}H (I) R-(O-{[CH(CH)CH-O-][CH-CH-O-]}H) (II) wherein R is hydrogen or an alkyl group of 2-8 carbon atoms; R is an alkylene moiety of 2-8 carbon atoms in which the two substituents are not carried on the same carbon atom; m is the mole percentage of propylene glycol in the ethylene/propylene glycol copolymer moiety or moieties; and n is the mole percentage of ethylene glycol in the ethylene/propylene glycol copolymer moiety or moieties, wherein the ratio n: m is in the range from 35:65 to 80:20; each glycol copolymer compound having a number average molecular weight in the range of 2000-10000; and 2) 3 to 15% by weight of a fumed silica gel former; said balancing compositions being visco-elastic and having a Storage Modulus (G') between 1500 Pa and 5000 Pa at 22C, a Loss Modulus (G") smaller than the Storage Modulus up to a Cross Over Frequency of 10-40 Hz, and a Critical Yield Stress exceeding 2 Pa. |
