Preparation of polyurethane foams without using inert blowing agents
申请人:UNION CARBIDE CHEMICALS AND PLASTICS COMPANY, INC.
公开号:EP0406702A1
公开(公告)日:1991-01-09
A process for making low density and optionally low resilience, soft, flexible polyurethane slabstock foam having a substantially open cell structure without crushing, without requiring auxiliary inert blowing agents, by reacting under a condition which permits the foam to rise freely, a conventional hydroxyl-containing polyether polyol with a polyisocyanate at an isocyanate index of between about 60 and 95 in the presence of a foam processing aid comprising a low equivalent weight crosslinking agent and/or extending agent and, as needed, a cell opening agent.
Reactive feed stream to replace inert blowing agent feed stream in a polyurethane foam process
申请人:UNION CARBIDE CHEMICALS AND PLASTICS COMPANY, INC.
公开号:EP0492464A2
公开(公告)日:1992-07-01
A process for manufacture of molded, high resiliency, polyurethane foam substantially free of volatile organic blowing agents comprising feeding at least three streams into a mixing device to form a reaction mixture, wherein a first stream contains (i) a polyol, (ii) water, (iii) a catalyst, (iv) a surfactant; a second stream contains an organic polyisocyanate; and a third stream contains (i) water, (ii) a crosslinking/extending agent, and (iii) a process/foam modifier.
It has been discovered that a particular polyurethane formulation may be used to prepare "pour-in-place" (PIP) polyurethane foam articles where the formulation is injected into a mold bearing an exterior covering such as a fabric without the foaming liquid striking through the layer. The formulation employs a hydrophilic polyhydric compound to help the reactivity balance that minimizes penetration of the exterior covering while also stabilizing the rising foam against shear collapse without excessively tightening the foam. Contrary to the conventional expectation that the hydrophilic polyhydric compound would cause strike through problems since it delays the initial reaction time, it has been found to have the noted stabilizing effect. A preferred hydrophilic polyhydric compound is glycerine. A preferred isocyanate for the formulation is tolylene diisocyanate (TDI), in contrast to diphenylmethane diisocyanate (MDI) heretofore used in PIP foams.
Manufacture of MDI-TDI based flexible polyurethane foams
申请人:——
公开号:US20020040072A1
公开(公告)日:2002-04-04
Process for flexible polyurethane foam manufacture via separate and variable component mixing of at least 3 separate component streams, where at least one of the streams is TDI and one other stream is a preferred composition of MDI. Further provided is an empirical method for determining the level of TDI over a wide range of water levels and formulation compositional differences.