摘要:
The instant invention is directed to novel mold release agents for polyurethane resins and to the use thereof, particularly in the closed mold forming of polyurethane foams. The mold release agents disclosed herein are applied to the surface of the mold prior to molding and broadly comprise talc dispersed in an emulsion of water and an organic solvent.
摘要:
The instant invention is directed to a process for the production of microcellular elastomeric moldings comprising:(A) introducing a reaction mixture into a closed mold, said reaction mixture comprising:(i) an organic polyisocyanate,(ii) a hydroxyl group containing compound having a molecular weight of from 1800 to 12,000,(iii) a catalyst for the reaction between hydroxyl groups and isocyanate groups,(iv) an active aromatic diamine having at least one alkyl substituent in the orthoposition to a first amino group and two alkyl substituents in ortho-position to a second group, and(v) air and/or nitrogen dissolved under pressure in any one or more of Components (i), (ii), (iii) or (iv),(B) allowing said reaction mixture to react in said mold and(C) removing the resultant product from said mold, the improvement wherein in any of Components (i), (ii), (iii) or (iv) which does contain said air and/or nitrogen dissolved therein there is included an inorganic, finely divided, nitrogen adsorbing agent in an amount sufficient to accelerate the transition of the air and/or nitrogen from the dissolved state to the dispersed state upon release of the pressure (i.e., as the liquid reacting mixture flows into the mold). It is this dispersed state which allows for adequate blowing during the process.