| 摘要 |
<p>1382178 Foamed carbodiimide linked polymers BASF WYANDOTTE CORP 25 Sept 1972 [1 Oct 1971] 44256/72 Heading C3C Rigid foamed polymers having carbodiimide linkages are made by the catalytic condensation of an organic polyisocyanate in the presence of 1-20 parts by wt. of an acrylonitrile grafted polyol per 100 parts by wt. of the polyisocyanate, the graft polyol having a mol. wt. of at least 1500 and a Brookfield viscosity of less than 40,000 c.p.s. at 25‹C. In the examples, a mixture of 2,4- and 2,6-toluene diisocyanates was condensed, using as catalyst a mixture of 2,4,6 - tris - (N - methylethanolamino) - 8- triazine and 1,3,5-tris-(N,N-dimethyl-3-aminopropyl)-s-hexahydrotriazine, in the presence of acrylonitrile grafted on to the propylene oxide adduct of glycerol or the ethylene oxide adduct of the reaction product of maleic anhydride and a propylene oxide/glycerol adduct, tris-(2-chloro-ethyl)phosphate as plasticizer, a polysiloxane surfactant and 1,1,2- trifluoro-1,2,2-trichloroethane as a supplemental blowing agent (to increase the closed cell content of the foam).</p> |
