CA2016328C

Foaming system for rigid urethane and isocyanurate foams

Abstract

This invention relates to a process for preparing a rigid, closed-celled polyisocyanate-based foam in the presence of water and a blowing agent. The blowing agent comprises one or more organic compounds, particularly halocarbons, having a boiling point of from 222K to 272K at atmospheric pressure, and is substantially free of organic compounds having a boiling point of 273K or greater. Preferred halocarbons are chlorofluoroethanes, especially chlorodifluoroethane (R-142b) and fluoroethanes.

CA2016328C, drawing sheet 1
Sheet 1 of 18

Term

Term ended

Expired 9 May 2010, 16.4 years ago.

  1. Priority
  2. Filed
  3. Granted
  4. Expired
  5. Today

10 claims: 5 independent, 5 dependent

  1. 1
    -25THE EMBODIMENTS OF THE INVENTION IN WHICH AN EXCLUSIVE PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:1. A process for preparing a rigid closedcelled polyisocyanate-based foam which comprises contacting and reacting an organic polyisocyanate with an active hydrogen-oontaining compound in the presence of water and a blowing agent characterized in that the blowing agent comprises one or more halocarbon compounds having a boiling point of from 222K to 272K and is substantially free of an organic compound having a boiling point of 273K or greater.
  2. 2
    A process as claimed in Claim 1 wherein the halocarbon compound has a boiling point of from 235K to 272K.
  3. 3
    A process as claimed in Claim 1 wherein the halocarbon is a chlorocarbon, a bromooarbon, a fluorocarbon, a chlorofluorocarbon or a bromofluorocarbon and is an adduct of methane, ethane propane, ethylene, propylene, a cylcloalkane or mixtures thereof.
  4. 4
    A process as claimed in any one of the proceeding claims wherein the halocarbon compound is a chlorofluoroethane, a fluoroethane or mixtures thereof. 37,764-F -252016328
  5. 5
    A process as claimed in Claim 4 wherein the chlorofluoroethane is chloropentafluoroethane (R-115), ohlorotetrafluoroethane (R—124 or isomer R-124a) or ohlorodifluoroethane (R-I42b).
  6. 6
    A process as claimed in Claim 4 wherein the fluoroethane is tetrafluoroethane (R—134 or isomer R-134a), trifluoroethane (R-143)» difluoroethane (R-152a) or fluoroethane (R-161).
  7. 7
    A process as claimed in Claim 4 wherein the halocarbon compound is chlorodifluoroethane (R-142b) or tetrafluoroethane (R—134 or isomer R-134a).
  8. 8
    A process as claimed in anyone of the preceding claims wherein water is present in from 0.5 to 10.0 weight percent based on total weight of active hydrogen-containing compound present.
  9. 9
    An isocyanate reactive composition which comprises (a) at least one active hydrogencontaining compound having an equivalent weight of from 50 to 700» and (b) from 1 to 25 percent by weight based of total weight of components (a) and (b) present of a blowing agent, characterized in that the blowing agent comprises one or more halocarbon compounds having a boiling point of from 222K to 272K and is substantially free of an organic compound having a boiling point of 273K or greater. 37,764-F -262016328
  10. 10
    A rigid, closed-celled polyisocyanate-based, foam prepared by contacting and reacting an organic polyisooyanate with an active hydrogen-containing compound in the presence of water and a blowing agent characterized in that the resulting foam contains within its cells a gaseous mixture comprising (a) from 10 to 75 mole percent based on total moles of (a) and (b) of one or more organic compounds having a boiling point of from 222K to 272K, and (b) from 25 to 90 mole percent based on total moles of (a) and (b) of carbon dioxide, and which is substantially free of an organic compound having a boiling point of 273K or greater. Ottawa,; C Patent A:37,764-F