| 摘要 |
<p>An epoxy nonolac resin having a relatively narrow mol. wt. distribution is of formula (I):-(where R is H or 1-5C alkyl, R1 is H, Cl, Br, 1-6C alkyl or glycidyloxy, and n has an av. value of >0.1) and is such that the ratio of viscosity (cS) at 70 degrees C. to av. epoxide equiv. wt. is 11 : 1 when Mw is 2000 and a plot of Mw versus Mw:Mn falls on or within the area bonded by 2000, 2; 6500, 5; 11000, 5; and 9000, 2, when Mw is >2,000. The low mol. wt. polymers (2000) may be used as adhesives, laminates, coatings and castings. The high mol. wt. polymers (>2,000) may be used as electrical varnishes, encapsulants and moulding powders. The high mol. wt. polymers show a reduction in soln. viscosity, increased heat distortion temp., increased flexural properties, a sharper melting point and/or improved flow properties, or a higher m.pt.</p> |
