| 摘要 |
An adhesive is the reaction prod. of (A) a true soln. of 10-70 (pref. 25-60) wt.% of a hydroxy-functional addn. copolymer (I), with Mn at least 3500 (pref. 4000-40,000), in 30-88 (pref. 40-75) wt.% of a high mol. wt. (at least 200) polyahl (II), and 2-20 (pref. 5-15) wt.% of a low mol. wt. (less than 200) polyahl chain extender (III); and (B) an organic polyisocyanate (IV), in amt. to react with all the active hydrogen moieties of (I), (II) and (III). - (I) consists of units from (a) 45-95 wt.% alkyl ester of an alpha, beta-unsatd. carboxylic acid; (b) 5-55 wt.% of a hydroxyalkyl ester of such an acid; and opt. (c) up to 50 wt.% of other monomer(s). - (A) is obtd. by addn. polymerisation of the component monomers of (I) dispersed in (II), using conventional free radical initiators, with (III) then added.
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