Covestro Deutschland Ag

Patrick Klasen

Hartmut Nefzger

Jörg Hofmann

Klaus Lorenz

Reinhard Albers

Hans-Detlef Arntz

Erhard Michels

Torsten Heinemann

Stephan Schleiermacher

Stephanie Vogel

Ernst Felske

Dirk Steinmeister

Stephan Moers

Dieter Seidel

Marion Frommont

Horst-Heinrich Schneider

The present invention relates to a method for producing a PUR/PIR foam body, comprising the steps of providing a mold adapted for applying an underpressure to the interior of the mold; introducing a reaction mixture comprising an isocyanate-reactive component A and an isocyanate B into the mold, and applying an underpressure to the interior of the mold, so the underpressure acts on the introduced reaction mixture. The underpressure is applied to the interior of the mold no later than the reaction mixture has started to set in the mold, and the isocyanate index of the reaction mixture is &#x2265;300.

Method for the vacuum-assisted production of a PUR/PIR foam body

The present invention relates to a process for producing a rigid polyurethane-polyisocyanurate foam C, comprising the step of reacting (i) an isocyanate-terminated prepolymer B with (ii) an activator component A comprising at least one trimerization catalyst A1 and at least one blowing agent A3 in a reaction mixture to form a foam, characterized in that&#x2014;there is used an isocyanate-terminated prepolymer B obtained from a reaction of an isocyanate B1 having a mean isocyanate functionality of from &#x2267;2.3 to &#x2266;2.9 with a polyol component B2, and&#x2014;the activator component A comprises water as the blowing agent A3 in an amount of from &#x2267;5 wt. % to &#x2266;50 wt. %,&#x2014;the isocyanate index in the reaction mixture is in a range of from &#x2267;400 to &#x2267;500, and&#x2014;the isocyanate content of the prepolymer B is in a range of from &#x2267;21 wt. % to &#x2266;30 wt. %, based on the total mass of the prepolymer B, and&#x2014;wherein in the reaction of the prepolymer B and the activator component A a conversion contribution to polyisocyanurate of &#x2266;75% is achieved. Rigid foams C so produced have good flame retarding properties while at the same time having good insulating properties and stability properties. The present invention relates further to a rigid polyisocyanurate foam C produced by the process according to the invention, to the use of such a rigid polyisocyanurate foam C in the production of heat-insulating structural components, and to a heat-insulating structural component comprising such a rigid polyurethane-polyisocyanurate foam.

Method for producing a hard polyurethane-polyisocyanurate foamed material

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Vettweiss, Germany

Patrick Klasen