Abstract: An improved process for the purification of antibodies from human plasma or other sources is disclosed. The process involves suspension of the antibodies at pH 3.8 to 4.5 followed by addition of caprylic acid and a pH shift to pH 5.0 to 5.2. A precipitate of contaminating proteins, lipids and caprylate forms and is removed, while the majority of the antibodies remain in solution. Sodium caprylate is again added to a final concentration of not less than about 15 mM. This solution is incubated for 1 hour at 25.degree. C. to effect viral inactivation. A precipitate (mainly caprylate) is removed and the clear solution is diluted with purified water to reduce ionic strength. Anion exchange chromatography using two different resins is utilized to obtain an exceptionally pure IgG with subclass distribution similar to the starting distribution. The method maximizes yield and produces a gamma globulin with greater than 99% purity.

Abstract: According to the invention, a special process for isolating polycarbonate from methylene chloride at temperatures of 30.degree. to 80.degree. C. in the form of a powder with residual solvent contents below 5% by weight is started up as a continuous process by starting up in a two-component nozzle, in which CO.sub.2 -containing fluid and the polymer solution are continuously combined, with a large excess of CO.sub.2 and then allowing the polycarbonate/methylene chloride/CO.sub.2 fluid system to pass through the gel-forming range of the polycarbonate/methylene chloride/CO.sub.2 phase diagram with continuous reduction of the CO.sub.2 throughput to a ratio of CO.sub.2 to organic solution of 4:1 to 2:1. The process started up in this way has a particularly long useful life.

Abstract: A process for isolating polymers from their solvents by addition of fluids containing carbon dioxide at temperatures of 30.degree. to 280.degree. C. and under pressures of 1 to 1,000 bar is disclosed. The process is characterized in that the concentration of the polymers in their solvents is between 5% and 80% by weight and the fluid containing carbon dioxide consists of at least 50% by weight carbon dioxide.

Abstract: A continuous process for the isolation of polycarbonates from a solution of polycarbonate in methylene chloride at temperatures of 30.degree. to 80.degree. C. is disclosed. The process which yields polycarbonate in powder form having residual solvent content of less than 5% by weight, is characterized in that it entails the following steps:a) obtaining a solution of polycarbonate in methylene chloride containing 10 to 40 percent polycarbonate, said percent being relative to the total weight of the polycarbonate solution,b) mixing into said solution under pressures of 10 to 50 bar and at temperatures of 30.degree. to 50.degree. C. a fluid containing carbon dioxide resulting in a non-gelling polycarbonate/methylene/chloride/dioxide pressurized system, in which between 10 and 12% CO.sub.2 are dissolved,c) mixing said pressurized system in a two-component nozzle with additional fluid containing carbon dioxide under a pressure of 50 to 300 bar and at temperatures of 40.degree. to 150.degree. C.

Abstract: 37 Highly dispersed mixtures of at least two polymers which are not completely miscible in the melt under customary conditions are produced by melting the polymers used in the presence of supercritical gases or mixtures of gases, intensively thoroughly mixing the molten polymers for long enough until the viscosity of the melt has diminished by at least 10%, subsequently cooling the polymer melt with further thorough mixing, until the viscosity of the melt has at least reached the original value again and then depressurizing the polymer melt. The highly dispersed mixtures produced in this way can be processed in the customary manner into mouldings.

Abstract: By treating aromatic polycarbonates, aromatic polyester carbonates and aromatic and/or araliphatic polyesters in the molten state with super-critical gases or gas mixtures under pressure, the melt viscosity of these polymers is considerably lowered so that basic chemical operations which proceed only incompletely under the usual conditions can be carried out on these thermoplasts.