| 摘要 |
Polyurethane (PU) elastomers (I) are obtd. from (A) isophorone:di-isocyanate (IPDI) and/or bis-(4-isocyanatocyclohexyl)-methane and (B) poly-THF and/or hexanediol polycarbonate with a mol.wt. of 1500-3000, in a mole ratio of (A):(B) = (1.2:1)-(30:1), (C) a chain extender mixt. contg. (C1) isophoronediamine (IPDA) and/or bis-(4-amino-cyclohexyl)-methane and (C2) 1,6-hexanediol, 1,4-butanediol, diethylene glycol, di- and tri-propylene glycol and/or hydroquinone di- beta -hydroxy-ethyl ether, with a mole ratio of (C1):(C2) = (60:40)-(20:80) and (D) 0.01-7 equivs. mono-isocyanate, -alcohol or -amine as mol. wt. regulator (w.r.t. NCO gps. in A); components (A), (B) and (C2) are first reacted together to form a NCO-prepolymer, which is then reacted with (C1) and (D) to give the polyurethane-urea; the mole ratio of (NCO gps.):(all active H atoms) = (0.9:1)-(1.2:1). Also claimed are (1) moulded prods., film and medical tubing and catheters made from (I); and (2) the above process. |
