Resilient coat for tie of direct-connection type track
US4652495A · kind A · utility
Assignees
Inventors
Key dates
| Filing date | Jan 31, 1986 |
| Grant date | Mar 24, 1987 |
| Priority date | — |
| Expiry date | Jan 31, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31598
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
A resilient coat for a direct connection-type tie (Danchoku tie) which is composed of a concrete tie body and a microcellular polyurethane elastomer coating layer which adheres to and coats the lower portion of the tie body to form an integral body therewith, and said microcellular polyurethane elastomer having urethane bonds and a bulk density of 0.4-0.75 g/cm.sup.3 and being prepared from the starting foamable liquid of urethane elastomer composed substantially of (a) a polyether polyol having an average number of functional groups of 2.5-4.5 and a number average molecular weight of 2000-8500, (b) a vinyl monomer-grafted polyol having an average number of functional groups of 2.5-4.0, and the graft ratio of 4-20% by weight, (c) a liquid polybutadiene polyol having hydroxyl terminal group(s), an average number of functional groups of 2.0-3.0 and a number average molecular weight of 2000-7000, (d) an organic polyisocyanate, (e) a chain extender, (f) a blowing agent, and (g) a urethanation catalyst, at such ratios that the NCO index is within the range of 90-110, and the concentration of the chain extender, based on the total amount of the five components of (a), (b), (c), (d) and (…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.