High-temperature rigid polyurethane spray foam for pipe insulation

Abstract

The present invention provides a rigid polyurethane spray foam, which is made using cyclopentane as the blowing agent and which is useful for pipe insulation because of its ability to withstand high-temperatures (>250 DEG F.). The inventive foams may be sprayed with existing foam spraying equipment because the foams are reacted at about a 1:1.25 polyol to isocyanate ratio.

Description

field of invention [0001] This invention relates generally to rigid polyurethanes, and more particularly to high temperature (>250F) rigid polyurethane spray foams using cyclopentane as the blowing agent. Such foam materials are particularly suitable as pipe insulation. Background of the invention [0002] In North America, insulated pipe manufacturers typically use materials such as asbestos, calcium silicate, mineral wool, and fiberglass to insulate pipes carrying substances at temperatures above 250°F. The insulating material is usually wrapped around the pipe and secured to it. [0003] Rigid polyurethane foam makes excellent pipe insulation and can be molded around the pipe, cut from a foam block stock, and fixed to the pipe, or sprayed onto the rotating pipe. In Europe, rigid polyurethane foam has been used to insulate locally heated pipes since the early 1960s. Polyurethane insulated pipes are also used in chemical plants for liquid tra...

AI Technical Summary

Problems solved by technology

However, the hexitol-based foams of Roetemund et al. do not react at a volume ratio of 1:1.25, and these foams do not erupt as described.