| 摘要 |
<p>A synthetic trans-1,4-polyisoprene latex, the polymer having a trans content of at least 80%, is obtained by agitating trans 1,4-polyisoprene together with an inert organic solvent therefor, an emulsifying agent and water, at a temperature below the boiling-point of said solvent to form a water-in-oil emulsion, subjecting said emulsion to a shearing force causing inversion thereof to an oil-in-water emulsion and stripping said solvent from the oil-in-water emulsion to form a dilute latex. The dilute latex is preferably concentrated to a solids content of from 50-70% by weight in two stages during at least one of which some at least of the emulsifying agent is separated from the latex. The emulsifying agent, which is preferably a mixture of air unsaturated fatty acid and an aliphatic compound selected from the group consisting of hydroxy amines, diamines and dihydric alcohols, is introduced in an amount of from 25 to 45% by weight of the trans 1,4-polyisoprene used and is present in the concentrated latex in an amount of from 0.5 to 6% by weight. The trans 1,4polyisoprene used preferably has an intrinsic viscosity of 1-4 when measured in toluene at 25 DEG C.</p> |
