| 摘要 |
1,040,640. Filamentary materials. FARBENFABRIKEN BAYER A.G. Dec. 7, 1964 [Dec. 17, 1963]. No. 49717/64. Heading B5B. Rod-form, dust-free solids are made from molten low molecular weight rigid materials which form a viscous melt which solidifies only slowly by extruding the melt through nozzles into a streamline flow of coolant to form suspended melt filaments of large diameter (e.g. 1 mm.) superficially solidifying the filaments in a first cooling section, wherein the coolant flows parallel to the filaments at a slightly different velocity so that the filaments no longer coalesce into drops under the effect of surface tension, internally solidifying the filaments thus stabilized in a second cooling section by a random flow of coolant and breaking the solidified filaments into pieces. Preferably the flow velocity of the cooling gas parallel to the-liquid filaments in the first cooling section is lower than the velocity of the filaments. In apparatus as shown, a thin-film evaporator 1 has an outlet 2 leading by pump 3 to nozzles 4. Each nozzle 4 is arranged concentrically in a tube 5 and all the tubes 5 lead into a single dropping shaft 6 over a collector 7. The tubes 5 comprise the first cooling section and the shaft 6 the second cooling section. A solution of the material may be evaporated in the evaporator 1 and the resultive melt extruded from the nozzles 4 as filaments of about 1 mm. diameter. Heat is removed from the filaments by means of a stream of cooling gas from tubes A, guided parallel to the filaments and having a flow velocity differing only slightly from the velocity at which the filaments leave the nozzle. In the dropping shaft 6 which constitutes the second cooling section the filaments are internally solidified. Final solidification of the filaments may be effected after they have gathered in a heap at the bottom of the apparatus, since the cooling gas can only leave the apparatus by passing through the heap. Specified materials include phenyl - α - naphthylamine, N - isopropyl - N<SP>1</SP> - phenyl - p - phenylene - diamine, Nibrene waxes, benzyl phenol, diphenylamine, masked isocyanates (phenyl urethanes), phenoxyacetic acids and phenoxypropionic acids, optionally with substituted phenyl radicals, e.g. 2,4 - dichlorophenoxyacetic acid, 2 - methyl-4- chlorophenoxyacetic acid and 2 - methyl - 4 - chlorophenoxypropionic acid and their alkali metal salts, thiono phosphoric acid esters and their derivatives, phenol-formaldehyde resins, polyester resins, and pure or co-condensation products of naphthalene sulphonic acids and phenols with formaldehyde. An example illustrates the manufacture of the herbicide, sodium - 2,4 - dichlorophenoxypropionate (2, 4 DP) in rod form, starting from its aqueous solution. |
