PURPOSE: To improve the appearance as well as the resistances to ozone, weather, flex-crack and external damage of the tyre by a method wherein a tyre side member is constituted by double layered structure of an outer surface layer, formed by a specified composition having a specified thickness, and an inner surface layer of a specified composition.
CONSTITUTION: A tyre side members, from the upper part of a bead 2 to the lower part of a shoulder 4 through a side wall 3, is made by the inner and outer double structure and a outer surface layer S1 is formed by a rubber composition consisting of 20W50 weight parts of chlorinated butyl rubber, 10W30 weight parts of ethylene-propylene-diene copolymer and 20W70 weight parts of diene series rubber so as to have a thickness of 0.3W1.5mm while an inner layer S2, contacting with the outer layer S1, is formed by the rubber composition consisting of the main constituents of the diene series rubber. Accordingly, the rubber composition, forming the outer surface of the tyre side member, is not contained wax or aging preventing agent, therefore, the appearance of the tyre will never be worsen by separating of these agents even after being used for a long period of time and the resistances of ozone, weather or the like may be maintained.
KUROSAWA MASAHIRO
HIRAKAWA HIROSHI
| JP45029903A | ||||
| JPS5580446A | 1980-06-17 | |||
| JPS5777207A | 1982-05-14 |