| 摘要 |
971,628. Polymerization reactors; controlling mixing by viscosity. GOODYEAR TIRE & RUBBER CO. Nov. 17, 1960 [April 20, 1960], No. 39485/60. Headings B1C and B1X. [Also in Division C3] In producing polymers by condensation reactions accompanied by an increase in viscosity whilst agitating the reaction mixture, after the power required by the agitator reaches a preselected value, it is supplied at a constant level to the agitator whereby degradation due to too rapid stirring of a viscous material, or long reaction times due to slow agitation are avoided. The process may be applied to linear polyamides, linear polyesters and alkyd resins. In the example, an initial stirring speed of 102-104 r.p.m. was employed with a temperature of 430- 560 ‹F. and a pressure of 0À1 mm. mercury. As polymerization progressed, more power was used to maintain this speed but when 24 kilowatts was reached, this energy was maintained while the revolutions fell to 35 r.p.m. The polymerization reactor 7 has a jacket 9 for cooling liquid, an outlet 8 for product, a stirrer 11 driven by motor 14 through a variable speed drive 13 and reducing gear 12. The power supply is maintained constant by a power controller 15 and the variable speed drive. |
