Abstract: Disclosed herein is an ion-exchange treatment apparatus for dispersions, which comprises (1) a main circuit including (a) a first separation means for separating coarse particles among dispersoids from a raw dispersion supplied thereto, (b) an ion-exchange treatment column containing a particulate ion-exchange resin having a single polarity, (c) a second separation means for separating the remaining dispersoids from the dispersion subjected to the ion-exchange treatment and (d) a flow path line for causing the means (a), (b) and (c) to communicate in series, and (2) a circulating circuit for returning at least part of the dispersion treated in the second separation means (c) to the first separation means (a). Another apparatus in which at least one combination of a separation means and an ion-exchange treatment column containing a particulate ion-exchange resin having a single polarity is arranged further in the main circuit is also disclosed.

Abstract: A method of modifying a synthetic resin comprises treating a solution or dispersion of the synthetic resin containing water-soluble electrolytes as impurities is treated with basic or acidic, water-insoluble fine particles which have been purified and classified, whereby cations having origin in the electrolytes are fixed in the acidic fine particles or anions having origin in the electrolytes are fixed in the basic fine particles. Synthetic resins modified in accordance with the modification method are produced.

Abstract: A water-deionizing system comprising a reservoir for receiving a quantity of water to be deionized, a first ion-exchanger unit capable of removing anions from said water, and a second ion-exchanger unit capable of removing cations from said water. The first and second ion-exchanger units are connected to said reservoir to form separate flow paths or circuits for circulating water from the reservoir through the units separately in parallel. The system permits efficient production of a relatively large amount of water in a batchwise operation and also facilitates the regeneration of saturated ion-exchangers.

Abstract: A system for producing deionized water comprising at least a pair of oppositely charged ion exchanger units connected in series, a pump, a sensor for detecting the level of specific conductivity of process water and lines connecting the pump, ion exchanger unit and sensor in a closed-loop flow circuit. A controller operates the system in a first mode in which a batch of process water is repeatedly circulated along the closed-loop flow circuit until the specific conductivity sensed is less than a first predetermined level and alternately in a second mode in which the batch of water so treated is discharged while another batch of water is introduced into the system until the specific conductivity sensed is greater than a second predetermined level which is higher than the first predetermined level.

Abstract: A method for the treatment of aluminum or aluminum alloy material comprising treating the material in a series of alkaline baths and a series of acid baths connected in series in regular order, said alkaline baths having an alkali concentration gradient continually decreasing from higher to lower values, the alkali concentration in the last stage bath being controlled to a defined level, and said acid baths having an acid concentration gradient continually decreasing from higher to lower values and the last stage bath being of pure water. The aluminum or aluminum alloy surface can be processed uniformly and economically by the instant process.

Abstract: The present invention provides a method of controlling an electrocoating bath using an ion exchange resin. The ion exchange resin is maintained in a porous container in a suspended state in the electrocoating bath, and is used in a quantity of not more than the chemical equivalent of excess counter-ion to be removed from the bath. Bath control is easily achieved without any coagulation trouble as often observed in conventional column methods.

Abstract: A process for preparing copolymers of acetylene and conjugated diene compounds by copolymerization of acetylene with at least one conjugated diene compound in the presence of a catalyst composition in a reactor, characterized in that the catalyst composition comprises a dialkyl aluminum halide, an organic nickel compound and an active hydrogen compound, of which the molar concentrations have the following relationships:[Al]=2[Ni]+[H][Al]/[Ni]>4wherein [Al], [Ni] and [H] represent respectively the molar concentrations of the dialkyl aluminum halide, of the organic nickel compound and of the active hydrogen compound, whereby the copolymer was obtained in a good yield without by-production of any gel material.