Process for forming a ditch liner
US5421677A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 7, 1994 |
| Grant date | Jun 6, 1995 |
| Priority date | — |
| Expiry date | Apr 7, 2014 |
Classification
- Technology area (CPC E)Fixed Constructions
- CPC primaryE02B3/12
- WIPO fieldCivil engineering
- WIPO sectorOther fields
Abstract
The invention is directed to a process of forming a ditch liner by dispensing a solidifiable liquid mixture onto a continuously moving porous blanket, applying pressure against the mixture and the coated blanket to form a continuous matrix within the blanket, laying the resulting coated blanket into a ditch before the liquid mixture has fully cured, conforming the coated blanket to the shape of the ditch, and allowing the mixture to fully cure. The improvement resides in using a reaction mixture of a polyisocyanate, up to 60% by weight of a filler, a specified polyol mixture and, optionally, a catalyst. The polyol mixture requires three different propylene oxide adducts: i) a propylene oxide adduct of an alkanolamine, ii) a propylene oxide adduct of a low molecular weight organic compound having from 3 to 8 OH groups, and iii) a propylene oxide adduct of a low molecular weight diol. The amounts of ii) and iii) are such that the mixture of ii) and iii) has an average OH functionality of from more than 2 to less than 2.8.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.