| 摘要 |
<p>1502344 Belt gearing UNIROYAL Ltd UNIROYAL Inc and UNITTA CO Ltd 30 March 1976 [11 April 1975] 14957/75 Heading F2Q In a toothed transmission belt having transversely extending teeth along one face of its body, within which is embedded an inextensible tensile member, the body is composed of a blend of an epihalohydrin polymer having a nominal Mooney viscosity of not more than 50 and an epihalohydrin polymer having a nominal Mooney viscosity of not less than 50, the ratio of lower viscosity polymer to that of higher viscosity being from 60 : 40 to 75 : 25 by weight. The combined body material preferably has an overall Mooney viscosity of less than 50. The component of higher viscosity may be a copolymer of epichlorohydrin and ethylene oxide, while that of lower viscosity may be an epichlorohydrin homopolymer, conveniently with 36-40% by weight chlorine content. Additionally, the body material may include a minor proportion of a butadiene-acronitrile or an isoprene-acronitrile copolymer. Conventional compounding ingredients are added. The tensile member may be composed of cords of glass fibre or of an aromatic polyamide, and may be bonded by an adhesive of a non-volatile isocyanate, in an organic solvent. Details of ingredients for two embodiments are given. It is stated that belts composed of this material may be used in applications, e.g. high-temperature vehicle engines, in which belts are exposed to temperatures of up to 120‹ C.</p> |
