| 摘要 |
The reactive polyurethanes have at least two urethane, thiourethane or urea groups plus at least two NCO-inert groups, each of which undergoes cleavage of protecting groups under acid, neutral or basic conditions to form at least two groups which are reactive towards isocyanates. The reactive polyurethanes (PU) are of formula (I); A(-NC(O)-Z-B-XY)n (I) A = 2-12C alkylene (optionally unsaturated), 3-18C cycloalkylene (optionally unsaturated) or 3-18C arylene (all optionally substituted), 7-18C arylene-alkylene, a heterocyclic group, or any linear or branched sequence of two or more of these groups; Z = NR, S or O; R = H, methyl or an alkyl, cycloalkyl or aryl group (optionally modified as for A), or any sequence of two or more of these; B = CH2 or alkylene, cycloalkylene or arylene groups as defined for A (or any sequence of two or more); n = 2-50; XY = a reactive residue which is inert towards isocyanate groups and which releases one or more protective groups Y under acid, neutral or basic conditions, leaving a residue X with at least two NCO-reactive groups. Independent claims are also included for (a) reactive PU obtained by reacting isocyanates of formula A(NCO)n (V) containing at least two NCO groups with compounds of formula HZ-B-XY (VI); (b) a process as described in (a) in which the molar ratio of NCO groups to HZ- groups is (0.8:1)-(1.2:1); (c) PU compounds with at least two urethane groups and twice as many NCO-reactive functional groups, obtained by hydrolysis of (I) under acid, neutral or basic conditions; (d) polyaddition or poly-condensation products obtained from PU compounds as defined in (c).
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