| 摘要 |
Polymers of conjugated diolefines having a 1,2-configuration of at least 80% and a molecular weight of 2,000-500,000 and prepared by polymerization in the presence of an organolithium compound and an ether solvent are used for coating metals or wood. The polymer is dissolved in a suitable solvent or used in solution as prepared and applied by dipping, painting or rolling and cured at 95-260 DEG C. for 10-30 minutes. A cobalt drier may be added in amounts of 0.01-2% by weight. The coatings on metal have good resistance to hot solder and are particularly useful in lining cans for food or drinks. The polymer may also be epoxidized by reaction with an organic peracid and such epoxidized products form hard, insoluble, infusible coatings on curing with an amine curing agent in a solvent, with heating if desired.ALSO:Conjugated diolefines are polymerized by bringing into contact with an organic lithium compound in an ether solvent and an inert atmosphere; the products have a 1,2-configuration of at least 80% and are thick liquids or solids having molecular weights (light scattering technique) of 2,000-500,000. Diolefines specified are butadiene, isoprene, dimethylbutadiene, piperylene, and methyl pentadiene which may be copolymerized with up to 30% by weight based on the total monomer of a second monomer such as styrene, alpha-methylstyrene, divinyl benzene, vinylpyridine or 2-methyl-5-vinylpyridine. The catalyst is preferably a hydrocarbon lithium or polylithium, e.g. ethyl-, butyl-, phenyl-, n-dodecyl-, octadecyl-, allyl-, phenyl-, cyclohexyl- or octyl-lithium, methylene-, ethylene-, pentamethylene-, decamethylene-, 1,4-benzene- or naphthalene-dilithium or 1,2,6-trilithium hexane used in amounts of 0.001-0.1 mol. per mol. of monomer. The ether solvent may be cyclic or acyclic, e.g. tetrahydrofuran, dioxane, diethyl ether or diamyl ether, and is used in amounts of 0.3-1.7 mol. per mol. of diolefine. Other solvents up to 25% of the total solvent may be added, e.g. benzene or toluene. Inert gases suitable for maintaining the inert atmosphere are nitrogen and methane. Temperatures of -40 DEG to 100 DEG C. are used and the pressure may be autogenous or higher or lower. Butadiene is preferably bubbled into the solvent-catalyst mixture over a period of time, e.g. 30 minutes to 4 hours. The catalyst is destroyed by adding water or alcohol in excess or in just sufficient quantity. The polymers may be used to form coatings which may be cured at 95-260 DEG C. for 10-30 minutes. Cobalt driers may be added. The polymers may also be epoxidized by reaction with a peracid such as performic, peracetic, perbenzoic, or monoperphthalic acid at - 20 DEG to 100 DEG C. The epoxidized polymers may be cured with amine curing agents. |
