Abstract: Method and apparatus for the distillation of liquids which is particularly suited for the removal of soluble impurities and insoluble and non-volatile particles of 10 microns to 0.2 micron or less in size. A substantially elongated distillation chamber having walls equipped with axially disposed concentric boiling rings spaced from the walls near the bottom, and a packing stop, packing redirector rings for condensed vapor, and a reflux condenser in the upper part of the distillation chamber provide, during distillation, a smooth convective upward flow of distilling liquid and vapor proximate the walls and boiling rings and a smooth convective downward flow of distilling liquid and vapor substantially centrally of the distillation chamber.

Abstract: Method for the production of ultrapure sulfuric acid including distillation of sulfuric acid material for the removal of soluble impurities and insoluble and non-volatile particles of 10 microns to 0.2 micron or less in size. Reprocessing is also provided. Distillation takes place in a distillation chamber having walls which are provided with means within the chamber to provide smooth convective upward flow of distilling liquid and vapor proximate the walls and means for smooth convective downward flow substantially centrally of the distillation chamber. Redirection means and packing together with reflux means insure the washing of rising vapor and direct the condensing vapor substantially centrally of the distillation chamber. Ultrapure sulfuric acid is also provided having 5 or less particles per cubic centimeter of a size of 0.5 micron and larger and less than 10 ppb of any specific trace impurity such as cations.

Abstract: A method for purifying hydrofluoric acid, comprising the steps of filtering the hydrofluoric acid to remove particulates, passing the filtered acid through a cation exchange material and an anion exchange material to remove ions therefrom, at least periodically automatically monitoring the acid that has passed through at least a predetermined portion of the cation exchange material for a predetermined level of cationic impurity representative of actual or impending ionic breakthrough in the cation exchange material, at least periodically automatically monitoring the acid that has passed through at least a predetermined portion of the anion exchange material for a predetermined level of anionic impurity representative of ionic breakthrough in the anion exchange material, automatically interrupting flow of acid through the anionic or cationic exchange material at or prior to the time the breakthrough in such material occurs, while the flow is interrupted, regenerating the anionic or cationic exchange material,

Abstract: An improved wafer cleaning process wherein a novel oxidant solution comprising ultrapure sulfuric acid, peroxydisulfuric acid, and ultrapure water used in a semiconductor wafer cleaning process is continuously withdrawn after use. The withdrawn oxidant is reprocessed continuously by contacting with alumina to remove fluoride ions. Water is continuously separated or stripped from the oxidant solution by heating the solution and bubbling an inert gas therethrough. The separated oxidant is continuously distilled and condensed to form a purified stream of sulfuric acid. The major portion of this stream is continuously returned to the wafer cleaning process. The remaining minor portion is continuously cooled, subjected to analysis for purity, and diluted with ultrapure water prior to electrochemical treatment in the anode compartment of an electrochemical cell. This converts at least a portion of the dilute sulfuric acid to peroxydisulfuric acid.

Abstract: A continuous process and apparatus for the repurification of ultrapure liquids. An oxidant solution comprising ultrapure sulfuric acid, peroxydisulfuric acid, and ultrapure water is continuously withdrawn from a process after use. The withdrawn oxidant is reprocessed continuously by contacting with alumina to remove fluoride ions. Water is continuously separated or stripped from the oxidant solution by heating the solution and bubbling an inert gas therethrough causing the water to vaporize from the solution. The separated oxidant is continuously distilled and condensed to form a purified stream of sulfuric acid. The major portion of this stream is continuously returned to the process. The remaining minor portion is continuously cooled, subjected to analysis for purity, and diluted with ultrapure water. The diluted sulfuric acid is further cooled prior to electrochemical treatment in the anode compartment of an electrochemical cell.

Abstract: An electroless copper plating bath is improved so as to facilitate its regeneration in an electrodialysis cell. The bath includes elevated amounts of an added salt, preferably as Na salt. The elevated sodium ion level serves as additional counter-cation to hydroxyl ion which is produced at the cathode of the electrodialysis cell. The excess anion from the added salt increases the rate of out-migration of by-products, such as formate ions and sulfate ions, relative to hydroxyl ions through an anion permselective membrane.

Abstract: The instant invention relates to a process for the conversion of an aryl halide into an aryl cyanide, which comprises the steps of:(a) providing a first electrode and a second electrode of opposite polarity from said first electrode in an electrolyte, said electrolyte comprising an aryl halide and a zerovalent Group VIII metal catalyst complex dissolved in a conductive solvent, wherein said Group VIII metal catalyst complex is capable of catalyzing the conversion of said aryl halide to an aryl cyanide in the presence of cyanide ions and susceptible to reaction with cyanide ions to yield a catalytically inactive Group VIII metal species,(b) providing cyanide ions in said electrolyte to convert said aryl halide to said aryl cyanide,(c) providing a flow of current between said electrodes, and(d) selectively controlling the electrical potential between said first and second electrode to convert said catalytically inactive Group VIII metal species to said zero valent Group VIII metal catalyst complex.

Abstract: An electrolytic process for producing hydrogen peroxide in an aqueous alkaline solution includes simultaneously passing an aqueous alkaline electrolyte and oxygen through a fluid permeable conductive cathode comprising reticulated vitreous carbon foam, separating the fluid permeable conductive cathode from an anode by a barrier and connecting the fluid permeable conductive electrode and the anode with an external power source to cause generation of hydrogen peroxide ion within the aqueous alkaline solution.

Abstract: A silicon-phthalocyanine-siloxane polymer having the formula ##STR1## WHEREIN Pc is a phthalocyanine nucleus, Ph is a phenyl group, n is an integer from 1 to 8, and x is an average value up to 20, is prepared by a method including a reaction of a phthalocyanine-silicon-disilanol with a bis(ureido) dialkyl silane or bis(ureido) siloxane or by the reaction of a phthalocyanine-silicon-disilanol with a bis(dialkyl) amino) silane or a bis(dialkylamino) siloxane. These polymers are useful as strengthening agents for high-temperature resins, such as polyimides, poly(phthalocyanines) or epoxies and as coatings or dyes.

Abstract: A silicon-phthalocyanine-siloxy monomer having the formula:PcSi(OSiR'Ph(OSiR".sub.2 ).sub.r X).sub.2wherein X is a hydroxyl group or unreido group having the formula: ##STR1## Pc is a phthalocyanine nucleus, R' and R" are alkyl groups having from 1 to 8 carbon atoms, and r is an integer from 1 to 4. The monomers are useful as dyes and in polymer synthesis as reactive intermediates.