| 摘要 |
<p>1385803 Epoxy resins SOC ITALIANA RESINE S I R SpA 28 Nov 1972 [27 Dec 1971] 55005/72 Heading C3B Self extinguishing epoxy resins having epoxide equivalent >2000 are prepared by a twostage process: (1) an intermediate product having an epoxide equivalent of 550-650 is prepared by reacting a halogenated compound: in which R 1 is Cl or Br; R 2 to R 8 are H, Cl or Br; X is NH or O; and R is C 2-8 alkylene or hydroxyalkylene, with epichlorohydrin in the presence of a Friedel-Crafts catalyst, e.g. BF 3 etherate, followed by dehydrochlorination in the presence of an inorganic base. The product is then extracted with a solvent. (2) After removal of solvent, the intermediate (100 parts by wt.) is reacted at 150-180‹ C. for 2 to 4 hours with 10-30 parts by wt. of bisphenol A in the presence of a catalytic amount of a tertiary amine or quaternary ammonium base. In the first stage, the molar ratio of epihalohydrin to halogenated monomer may be 3À0 : 1 to 6À5 : 1 using KOH or NaOH as inorganic base at 2-3 moles per mole of halogenated monomer. Uses.-Impregnation of glass or paper fibres, laminates, varnishes.</p> |
