Abstract: Polymer scale deposition on polymerization reactor inside surfaces in the polymerization of a monomer or monomers having an ethylenic double bond and/or a monomer or monomers having diolefinic double bonds is prevented, peelability or removability of polymer scales deposited on such surface, if any, is improved and the scale inhibitor adherence to the wall surface of glass-lined polymerization reactors is improved by coating the inside surfaces of the reactor in advance with a coating composition comprising a quinone-amine compound having a molecular weight of at least 3,000 as obtained by subjecting at least one aromatic diamine and at least one aromatic quinone to addition reaction in at least one solvent having a solubility parameter of 8.5 to 24.0 and/or a reduced form of said quinone-amine compound and at least one silica organosol or a mixture of at least one silica organosol and at least one alkyl silicate to thereby form a hydrophilic coat film on the surfaces.

Abstract: A chemical cleaning method for removing scales and other substances deposited on the interior of a polymerization reactor used in emulsion polymerization or suspension polymerization. This method comprises chemically cleaning the interior using an aqueous solution or dispersion of an alkali agent and a surfactant. According to this method of cleaning, scales deposited on the interior of a polymerization reactor, in particular, scales deposited during polymerization on the inside surface, an agitator and baffle-plates of the reactor are completely removed.

Abstract: A cleaning method for removing scales, etc., deposited on the interior of a polymerization reactor which has been used in emulsion or suspension polymerization. This method uses a chemical cleanser comprising a soap builder an, alkali agent, an aqueous solution or dispersion of a surfactant, and an organic solvent and/or polymerizable monomer. This system may further contain a plastic packing such as tellerettes. By this method, scales deposited on the interior of a polymerization reactor, particularly, scales deposited on the inside surface, agitator, and baffle-plates of the reactor, are compeltely removed.

Abstract: An apparatus for cleaning a tank-like vessel comprising(a) a supporting arm attached to a fixing plate, which can perpendicularly extend downward,(b) a folding arm of which base portion is rotatably attached to the lower end of the supporting arm, a position of the folding arm being changeable between a housed position and a position in use wherein the folding arm is approximately horizontally stretched out,(c) a rope winded up and winded down by a hoist, and(d) a cleaning nozzle capable of injecting jet water in a two-dimensional direction or three-dimensional direction.

Abstract: A process for preparing a scale deposition preventing agent of a quinone-amine compound suitable for use in a polymerization of acrylic or methacrylic acid ester monomers, which comprises (A) subjecting an aromatic quinone and an aromatic diamine to addition reaction in a solvent having a solubility parameter of 8.5 to 24.0 to give an addition product, and (B) converting the addition product into a high molecular weight compound within 24 hours after beginning the addition reaction (A) by adding an oxidizing agent to the addition reaction mixture or by subjecting the addition reaction mixture to anodic oxidation with an electrode to give a quinone-amine compound. According to the present invention, the preparation rate of the scale deposition preventing agent of the quinone-amine compound can be remarkably increased, the yield can be increased, and the obtained compound has excellent properties.

Abstract: Method and apparatus of installation of a membrane to a finger type electrolytic cell are provided, which comprise covering the horizontal surfaces of a cathode not opposing an anode with a membrane installation frame having a collar, positioning the membrane substantially parallel to the vertical surfaces of the cathode, and installing and securing the membrane to the collar by bolting. Not only is operation efficiency for the membrane installation to the electrolytic cell markedly improved, but also, in the case of an ion exchange membrane, an alkali metal hydroxide liquor hardly containing an alkali metal chloride is produced. According to the invention, a conventional asbestos diaphragm finger type electrolytic cell is advantageously converted to an ion exchange membrane electrolytic cell.

Abstract: A cylindrical cation exchange membrane is described for use in electrolysis of an aqueous alkali metal chloride solution in a finger type electrolytic cell, wherein the equivalent weight of the area not facing the effective electrolytic surface of anode is greater than the equivalent weight of the areas facing the effective electrolytic surface, thus permitting a reduction of the alkali metal chloride content of an effluent from a cathodic chamber.

Abstract: A membrane for electrolyzing an alkali metal chloride solution using a finger type electrolytic cell equipped with a cation exchange membrane, wherein areas of said membrane not facing the effective electrolytic surface of the anode have a higher stiffness and a lower anion permeability than the areas of said membrane facing the effective electrolytic surface of the anode, thus reducing the alkali metal chloride content in the alkali metal hydroxide aqueous solution obtained from the cathodic chamber.

Abstract: Process for the electrolysis of an aqueous alkali metal chloride solution using a cation exchange membrane, wherein the gas-liquid interface, at which halogen gas is separated, is maintained larger than the sum total of the cross section area of the unit anode chambers opposing to cathodes, and further, higher than the upper end of the cation exchange membrane. The invention has numerous advantages including substantial absence of halogen gas, operation at a low voltage, a high pure product, simplification of operation control and the like.

Abstract: Apparatus for the electrolysis of an aqueous alkali metal chloride solution using a cation exchange membrane, wherein the apparatus is designed so that gas-liquid interface, at which halogen gas is separated, is maintained larger than the sum total of the cross section area of the unit anode chambers opposing to cathodes, and further, higher than the upper end of the cation exchange membrane. The invention has numerous advantages including substantial absence of halogen gas, operation at a low voltage, a high pure product, simplification of operation control and the like.

Abstract: Method and apparatus of installation of a membrane to a finger type electrolytic cell are provided, which comprise covering the horizontal surfaces of a cathode not opposing an anode with a membrane installation frame having a collar, positioning the membrane substantially parallel to the vertical surfaces of the cathode, and installing and securing the membrane to the collar by clipping. Not only is operation efficiency for the membrane installation to the electrolytic cell markedly improved, but also, in the case of an ion exchange membrane, an alkali metal hydroxide liquor hardly containing an alkali metal chloride is produced. According to the invention, a conventional asbestos diaphragm finger type electrolytic cell is advantageously converted to an ion exchange membrane electrolytic cell.

Abstract: Method and apparatus of installation of a membrane to a finger type electrolytic cell are provided, which comprise covering the horizontal surfaces of a cathode not opposing an anode with a membrane installation frame having a collar, positioning the membrane substantially parallel to the vertical surfaces of the cathode, and installing and securing the membrane to the collar by bolting. Not only is operation efficiency for the membrane installation to the electrolytic cell markedly improved, but also, in the case of an ion exchange membrane, an alkali metal hydroxide liquor hardly containing an alkali metal chloride is produced. According to the invention, a conventional asbestos diaphragm finger type electrolytic cell is advantageously converted to an ion exchange membrane electrolytic cell.

Abstract: Electrolysis of an alkali metal chloride solution using an ion exchange membrane is carried out by bringing the anode and the cathode into contact with the surfaces of the ion exchange membrane, whereby electrolysis is conducted at a lower voltage and alkali metal chloride contained in the cell liquor is markedly reduced. In the case of employing a finger type cell, alkali metal chloride in the cell liquor is surprisingly lowered by maintaining the ratio of the effective area of the cation exchange membrane to that of the anode at 1.1 or less. This invention facilitates the conversion of asbestos or modified asbestos electrolysis methods to the ion exchange membrane methods with such ease that the quality of the products is not only enhanced but the serious problems of environmental pollution due to asbestos are solved.

Abstract: Method for electrolysis of an aqueous alkali metal chloride solution is provided, wherein an aqueous alkali metal chloride solution is electrolyzed by maintaining a temperature of an aqueous alkali metal hydroxide liquor in a cathode compartment lower than that of the aqueous alkali metal chloride solution in an anode compartment, using an electrolytic cell which is separated by a cation exchange membrane into the anode compartment and the cathode compartment. Not only is current efficiency improved without adverse effects on voltage, thus enabling a long period operation with low electric power consumption, but also high purity alkali metal hydroxide containing a reduced amount of chloride ion is produced.