Abstract: A pre-tensioner of a seat belt device capable of securely and rapidly transmitting torque between a driven shaft and a rotational ring when the pre-tensioner is activated. The driven shaft projecting from a reel for retracting a seat belt is inserted into a housing and the rotational ring is positioned to surround a gear of the driven shaft. The rotational ring is provided with five guide faces in the inner surface thereof and pins are inserted into pocket portions of the rotational ring. Each pin is held at the both ends by an annular portion of a body and a cover. Stepped portions are formed along peripheries of both ends of each guide face to form spaces.

Abstract: A process for preparing diacetoxybutene, including:reacting butadiene, acetic acid and oxygen in the presence of a palladium-based catalyst;feeding continuously the resulting reaction product into a first distillation tower;feeding continuously a withdrawn bottoms withdrawn from the first distillation tower into a second distillation tower;withdrawing bottoms containing high boiling point materials from the bottom of the second distillation tower, so that the content of the high boiling point materials in the bottoms of the second distillation tower is not more than 20 wt %;feeding continuously the withdrawn bottoms into a thin-film evaporator whose internal pressure is kept lower than the bottom pressure of the second distillation tower to carry out evaporation treatment; andrecycling the evaporated materials mainly containing diacetoxybutene into the second distillation tower.

Abstract: A method for recovering 1,4-butanediol from a hydrolysate obtained by hydrolyzing diacetoxybutane, by (1) supplying the hydrolysate to a first distillation column, distilling off substantially all the amounts of water and acetic acid as the top stream from the first distillation column, and supplying a bottom liquid to a second distillation column, (2) distilling off diacetoxybutane and hydroxyacetoxybutane as the top or upper side stream from of the second distillation column, and circulating the distillates to a hydrolysis zone, while withdrawing crude 1,4-butanediol as a lower side stream in vapor phase from the second distillation column, (3) supplying the crude 1,4-butanediol and hydrogen gas to a hydrogenation reaction zone packed with a hydrogenation catalyst, and (4) supplying the hydrogenation reaction product to a third distillation column, distilling off low boiling point components and withdrawing 1,4-butanediol as the bottom or side stream from the third distillation column.