| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for producing a pad for a railroad, satisfying all of a low spring constant suitable for exhibiting vibration proof and damping performance, a good compression characteristic, a high mechanical strength and durability in a good balance, and consisting of a polyurethane-foamed material having a minute cellular structure having less unevenness in its size depending on section. SOLUTION: This method for producing the pad for the railroad consisting of the polyurethane-foamed material is provided by mechanically agitating a composition containing (A) an MDI-based NCO group terminal pre-polymer, (B1) a polyol having 2.0-4.0 mean number of functional groups and 1,000-6,000 number-average molecular weight and (B2) a chain extender having 2-4 number of functional groups and≤600 molecular weight, and having 0.80-1.20 [NCO]/[OH] ratio under an inert gas atmosphere to produce a froth-formed raw material by dispersing the inert gas in the composition and then casting the raw material into a mold for curing. COPYRIGHT: (C)2006,JPO&NCIPI |
