摘要:
A solution of a fluorinated polymer having groups having the formula--COOMwherein M represents an alkali metal atom or a metal atom in group II a or II b of the periodic table or ammonium group or an amine group in a highly polar organic solvent.
摘要:
A cation exchange membrane of a fluorinated polymer used for an electrolysis of an alkali metal chloride is obtained by treating a cation exchange membrane having ion exchange groups of --COOM (M is hydrogen atom or an alkali metal atom) or groups being convertible to said groups and having an ion exchange capacity (A.sub.R) of 0.5 to 2.0 meq/g dry polymer in a hydrolyzed form, to give a weight gain percent (.DELTA.W.sub.R) in the range of .DELTA.W.sub.R =1.6e.sup.1.7A R as the upper side; .DELTA.W.sub.R =0.8e.sup.1.7A R as the lower side; A.sub.R =0.5 as the left side and A.sub.R =2.0 as the right side shown in FIG. 1 (log scale on ordinate) in an aqueous medium of a base or a salt at a concentration of 1 to 20 wt. % at the temperature of 0.degree. to 60.degree. C. after the hydrolysis or at the time of the hydrolysis.
摘要:
An electrolysis of an aqueous solution of potassium chloride is carried out by employing a fluorinated cation exchange membrane having an ion-exchange capacity of 0.8 to 2.0 meq/g dry polymer and having carboxylic acid groups as functional groups and maintaining a concentration of an aqueous solution of potassium hydroxide in a cathode compartment in a range of 20 to 45 wt. % and maintaining a calcium concentration in the aqueous solution of potassium chloride to lower than 0.05 mg/liter.The purification of the aqueous solution of potassium chloride to reduce the calcium concentration is carried out in a system comprising a chelate ion-exchange substance.
摘要:
An unsaturated aldehyde having three to four carbon atoms is prepared by reacting the corresponding olefin with molecular oxygen in the vapor phase at a temperature of from 350.degree. to 520.degree. C in the presence of a metal oxide catalyst comprising the metallic components: (a) molybdenum; (b) at least one metal selected from the group consisting of niobium and tantalum; and (c) at least one metal selected from the group consisting of tellurium, bismuth, cobalt, tungsten, indium, and titanium.
摘要:
Perfluoroaklyl iodides are prepared by reacting iodine, iodine pentafluoride and tetrafluoroethylene in the presence of a fluoride catalyst selected from the group consisting of niobium fluoride, tantalum fluoride, boron fluoride, and molybdenum fluoride.