Gel permeation chromatographic packing and process for producing same utilizing suspension polymerization

Claim 1

A packing for high speed liquid chromatography prepared by the process which comprises suspending in water a mixture consisting of 65 to 90 parts by weight of at least one monovinylbenzene, 35 to 10 parts by weight of at least one polyvinylbenzene, the total amount of the monovinylbenzene and polyvinylbenzene being 100 parts by weight, and 30 to 200 parts by weight of a solvent capable of dissolving polystyrene, and free radical-polymerizing the monovinylbenzene and the polyvinylbenzene in suspension, said polymerizaton being carried out in the presence of 0.1 to 5.0 parts by weight of at least one free radical polymerization initiator having a half-life period of about 2 to 60 minutes at 70° C., and in such a manner that at least until the polymerization conversion reaches 50%, the polymerization is effected at a temperature at which the half-life period of the polymerization initiator is in the range of about 5 to 120 minutes to thereby provide a microporous, granular cross-linked monovinylbenzene-polyvinylbenzene copolymer having a volume average particle diameter of about 2 to 50 micrometers, an exclusive molecular weight for polystyrene of about 500 to 20,000, and the weight percent (X) of polyvinylbenzene units based on the total monomeric units in the copolymer and the gradient (α) of the calibration curve of the polystyrene are defined by the region bounded by and including the following three lines in rectangular coordinates (α, X): ##EQU11## α=2.5 X=35.