Abstract: In a reaction for introducing chloromethyl groups into an aromatic crosslinked copolymer by reacting chloromethyl methyl ether to the aromatic crosslinked copolymer in the presence of a chloromethylation reaction catalyst, a method for recovering chloromethyl methyl ether from the reaction mixture, which comprises the following steps 1) a step of adding to the reaction mixture an aqueous acid solution which is capable of dissolving the chloromethylation reaction catalyst without decomposing chloromethyl methyl ether, and an extraction solvent which is inert to and miscible with chloromethyl methyl ether and which is capable of swelling the chloromethylated aromatic crosslinked copolymer, 2) a step of contacting hydrogen chloride gas to the reaction mixture and the extract solution from the step 1 to convert decomposition products of chloromethyl methyl ether, to chloromethyl methyl ether, 3) a step of separating the resulting mixture from the step 2 into an extraction solvent layer containing chloromethyl met

Abstract: A method for producing a large size crosslinked polymer bead, which comprises dispersing a monomer phase composed essentially of a monovinyl monomer and a crosslinkable monomer in an aqueous phase containing a dispersion stabilizer and subjecting the dispersion to suspension polymerization in an oil-in-water system in the presence of a polymerization initiator, wherein: 1 at least one specific gravity-controlling agent having a specific gravity of more than 1.0 selected from the group consisting of water-insoluble inert organic solvents and water-insoluble linear polymers soluble in the monomer phase, is added to the monomer phase, and 2 if necessary, at least one specific gravity-controlling agent selected from the group consisting of water-soluble inorganic salts, is added to the aqueous phase, 3 to adjust the specific gravities (at 25.degree. C.) of the monomer phase and the aqueous phase in the ranges represented by the following formula (I):B-0.03<A<B+0.

Abstract: A method for preparing an oil-in-water type uniform dispersion of liquid droplets, which comprises ejecting into an aqueous medium containing a dispersion stabilizer, which forms a continuous phase and moves upwards, a hydrophobic liquid having a specific gravity smaller than the aqueous medium, through a nozzle plate having a plurality of perforations capable of ejecting the hydrophobic liquid upwards, to form liquid droplets of the hydrophobic liquid in the aqueous medium, wherein a nozzle plate having a number of perforations for ejection arranged in a ring form is used as said nozzle plate, and a polymerization method for preparing polymer beads of uniform particle size, which comprises applying the method for preparing an oil-in-water type uniform dispersion of liquid droplets.

Abstract: A method for increasing the porosity of a cross-linked copolymer composed essentially of at least one monovinyl aromatic compound selected from the group consisting of styrene, vinyl toluene and ethyl vinyl benzene, at least one polyvinyl aromatic compound selected from the group consisting of divinyl benzene, trivinyl benzene, divinyl toluene and divinyl xylene, and an aliphatic vinyl compound, wherein the proportion of the polyvinyl aromatic compound relative to the total vinyl compounds is from 8 to 80% by weight, and the proportion of the aliphatic vinyl compound relative to the total vinyl compounds is from 0 to 20% by weight, which method comprises treating particles of said copolymer with a Lewis acid catalyst in an amount of from 0.05 to 1 part by weight relative to 1 part by weight of the copolymer particles, in the presence of an organic solvent.