| 摘要 |
Unsaturated polyesters are made by reacting (1) an anhydride of an alpha-beta-unsaturated dicarboxylic acid (e.g. maleic or citraconic anhydride) with (2) thylene-, 1 : 2-propylene-, 1 : 2-butylene- or 2 : 3-butylene oxide, in the presence of (3) 0.05-0.1 mol. per mol. of anhydride of a monohydric and/or dihydric alcohol. Part of the unsaturated anhydride may be replaced by an saturated dicarboxylic anhydride, e.g. phthalic, tetrahydrophthalic or tetrachlorophthalic anhydride. The reaction mixture may also include a substance capable of forming a Diels-Alder adduct with the anhydride, e.g. cyclopentadiene, dicyclopentadiene, hexachlorocyclopentadiene, 9 : 10-diethylanthracene or terpenes such as colophony. Specified alcohols for reactant (3) are ethanol, propanol, butanol, hexanol, octanol, 2-chloroethanol and monoethanolamine; ethylene-, 1 : 2- or 1 : 3-propylene-, 1 : 3-butylene-, diethylene-, triethylene-, dipropylene- or tripoppylene-glycols; also diethanolamine and the reaction product of 1 mol. of diphenylol propane and 2 mols. of ethylene oxide. Suitable polyesterification catalysts are oxides and salts (e.g. carbonates or stearates of magnesium, zinc and lead) and ion-exchangers containing zinc and cation. The unsaturated polyesters may be copolymerized in normal manner with monomers such as styrene, chlorostyrenes, diallyl phthalate, triallyl cyanurate and vinyl carbazole using a mixture of M.5.K. peroxide and cobalt naphthenate as catalyst. Fillers, e.g. glass fibres or asbestos may be added prior to hardening. |
