| 摘要 |
Epichlorohydrin, 2,2 - bis(4 - hydroxy - 3,5 - dibromophenyl)-propane, and a methanol solution of sodium hydroxide were heated together at 65 DEG C., salt was filtered off and the filtrate stripped by distillation to yield brominated polyglycidyl ether with a Durran's softening point of 45-50 DEG C., oxirane oxygen content of 4.4% and epoxide equivalent of 364.ALSO:A polyglycidyl ether of a polynuclear phenol, having a plurality of bromine or chlorine atoms attached to nuclear carbon atoms, and being free from groups reacting with an acid anhydride other than hydroxyl and epoxy groups, is brought to the form of a stable liquid having a viscosity of less than 80,000 cps. at room temperature by admixture with a polycarboxylic acid anhydride which has a melting point not greater than 40 DEG C. The composition can be cured to a flame retardant state in the presence of sufficient polycarboxylic acid anhydride to yield 0.5-2 anhydride groups per epoxy group and of a catalyst for epoxyanhydride reactions. The composition may also include liquid non-halogenated epoxy resins, e.g. EPON 828 or Epiphen 849. The brominated epoxy resin specified is prepared from brominated bisphenol, e.g. 2,2,bis-(4 - hydroxy - 3,5 - dibromophenyl)propane, and epichlorohydrin. Anhydrides specified are Dills-Alder adducts of maleic anhydride, e.g. methyl endomethylene tetrahydrophthalic anhydride; an adduct of maleic anhydride and myrcene; or tetrapropenyl succinic anhydride prepared from maleic anhydride and the tetramer of propylene. Suitable catalysts for the curing reaction are basic tertiary amines, e.g. dimethylbenzyl amine and salts thereof, or Lewis acids, e.g. boron trifluoride or stannic chloride. Fillers, thixotropic agents, pigments, flexibilizing co-reactants or reaction diluents may be included in the curable compositions. In examples (1) a stable liquid mixture of the brominated polyglycidyl ether referred to above and methyl-endomethylenetetrahydrophthalic anhydride was prepared. With addition of tris - (2,4,6 - dimethylaminomethyl)-phenol it could be cured in 3 hours at 120 DEG C. If desired the composition before curing could include 35% talc and 5% antimony trioxide. (2) Myrcene-maleic anhydride is used to liquefy the brominated glycidyl ether, and methyl-endomethylene-tetrahydrophthalic anhydride and tris - (2,4,6 - dimethylaminomethyl)phenol were added to make a curable mixture. The curable composition may include talc and antimony trioxide. (3) The brominated polyglycidyl ether was liquefied with myrcene-maleic anhydride adduct, and the mixture cured with an acid-terminated polyester prepared from maleic anhydride and polypropylene glycol with tris-(2,4,6-dimethylaminomethyl) phenol as catalyst. The curable composition may include talc and antimony trioxide. (4) The compositions of Example (3) were modified by inclusion of some EPON 828-a conventional epoxy resin. The compositions are useful as casting resins, wire insulation, or impregnants for glass cloth.
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