Polyurethane ballast layer, the method for preparing the same and the use thereof

摘要

The present invention relates to a polyurethane ballast layer, the method for preparing the same and a railway comprising the polyurethane ballast layer. The polyurethane ballast layer provided in this invention comprises a polyurethane-filled ballast layer and a polyurethane external protective layer, wherein the polyurethane-filled ballast layer comprises ballasts and polyurethane foam filled in the space among the ballasts. The polyurethane ballast layer provided in this invention can reduce the probability of ballast crashing, shifting and cracking under heavy load, and separate the ballast track from the outside environment to prevent rain, snow and wastes from entering into the internal space of the ballast track bed. Furthermore, the polyurethane ballast layer can keep the polyurethane foam filled in the ballasts layer away from water in the outside environment to avoid hydrolysis. The polyurethane ballast layer presented in this invention can be used in the railway ballast track bed to extend the track bed maintenance cycle, and save maintenance cost significantly.

主权项

1. A method comprising
providing a polyurethane-filled ballast layer spraying a first reaction system onto a surface of the polyurethane-filled ballast layer to form a polyurethane external protective layer, wherein the first reaction system comprises 1a) one or more polyisocyanates having a general formula R(NCO)n, wherein, R is selected from the group consisting of an aliphatic alkyl group comprising 2 to 18 carbon atoms, an aromatic alkyl group comprising 6 to 15 carbon atoms and an arylated alkyl group comprising 8-15 carbon atoms, and n is an integer from 2 to 4; 1b) one or more polyether polyols and/or amine terminated polyether, having an average molecular weight of more than 200 and a functionality from 2 to 6; 1c) one or more extender; and 1d) from 0 to 0.5% by weight of one or more blowing agent, based on 100% by weight of 1b) and 1c); wherein the tensile strength of the polyurethane external protective layer is from 4 to 20 MPa.