Abstract: Improved covers for electrolytic capacitors, offering both durability and low extractability of halides by high temperature electrolytes, can be produced from molding compositions comprising thermoset polymers having low halide extractability, preferably based on materials such as phenolic resins, and nonporous fillers, the compositions preferably being essentially free of porous fillers.

Abstract: Improved covers for electrolytic capacitors, offering both durability and low extractability of halides by high temperature electrolytes, can be produced from molding compositions including thermoset polymers having low halide extractability, preferably based on materials such as phenolic resins, and nonporous fillers, the compositions preferably being essentially free of porous fillers.

Abstract: An electrolytic solution is comprised of a borate, at least one dicarboxylic acid and at least one hydrotropic agent. The hydrotropic agent serves to maintain soluability at low temperatures, for example, in glycol type solvents. The invention also provides use of 1,10 dodecanedioic acid or dimer acid, thus improving the cost of the electrolyte is improved over use of branched chain dicarboxylic acids, while the use of the hydrotropic agent maintains solubility at acceptable temperatures.

Abstract: An electrochemical cell for etching a metal workpiece such as an aluminum foil, a method for etching the foil using the electrochemical cell, and foil thus produced is provided. The cell includes an etch tank having an etch electrolyte disposed therein and containing at least a first and a second compartment each containing (i)an etch electrolyte, (ii) a cathode plate, and (iii) an ion exchange membrane separator portion having an ion exchange polymeric material effective to substantially retard or prevent reduction of the oxidizing agent or agents present in the etch electrolyte, the first and second compartments being arranged in the etch tank with the ion exchange membrane separator portions in facing relationship one to the other; and a metal workpiece such as an aluminum foil anode present in the etch tank and disposed between each said first and second compartments.

Abstract: An electrochemical cell for etching a metal workpiece such as an aluminum foil, a method for etching the foil using the electrochemical cell, and foil thus produced is provided. The cell includes an etch tank having an etch electrolyte disposed therein and containing at least a first and a second compartment each containing (i)an etch electrolyte, (ii) a cathode plate, and (iii) an ion exchange membrane separator portion comprising an ion exchange polymeric material effective to substantially retard or prevent reduction of the oxidizing agent or agents present in the etch electrolyte, the first and second compartments being arranged in the etch tank with the ion exchange membrane separator portions in facing relationship one to the other; and a metal workpiece such asan aluminum foil anode present in the etch tank and disposed between each said first and second compartments.

Abstract: An electrolytic capacitor having aluminum anode and cathode members separated by a paper insulating spacer impregnated with a solution of mostly a glycol, water, unsaturated aliphatic dicarboxylic acid, aliphatic diene monocarboxylic acid, monohydric aliphatic alcohol, dodecanedioic acid, phosphoric acid, nitro aromatic compound having a benzene ring-substituted nitro moiety and a dialkylamine in an amount sufficient to provide a pH of 7.0-8.5.

Abstract: An electrolytic capacitor having aluminum anode and cathode members separated by a paper insulating spacer impregnated with a solution of mostly a glycol or a glycol ether and minor amounts of water, pelargonic acid, isophthalic acid or terephthalic acid and an aliphatic amine sufficient to provide a pH of 7.2-7.5.

Abstract: An electrolyte adapted for use as fill electrolytes in eletrolytic capacitors having aluminum cathodes and anodes useful in a low to high voltage operating range which electrolyte contains an improved non-toxic depolarizer.

Abstract: An electrical capacitor having aluminum anode and cathode members separated by an insulating spacer impregnated with an electrolyte consisting of a solution containing from 50%-70% by weight of N-methylformamide, up to 30% by weight of 2-methoxyethanol, 2-ethoxyethanol, ethylene glycol or 1,2-propylene glycol, 12-20% by weight of an aromatic dicarboxylic acid selected from the group consisting of isophthalic acid and terephthalic acid, from 4%-10% by weight of dimethylamine or monomethylamine, the ratio of the amine to the dicarboxylic acid being less than 2.00:1 and greater than 1.67:1, up to 0.5% by weight of pelargonic acid, up to 0.1% by weight of phosphoric acid and up to 8% by weight of water.

Abstract: An electrolytic capacitor having aluminum anode and cathode members separated by an insulating spacer impregnated with an electrolyte which is free of dibasic acids including citric acid. The electrolyte consists essentially of a solution of boric acid and an amine having a molecular weight of not greater than 175 in a mixture of a member of the group consisting of butzrolactone, dimethylacetamide and dimechylformamide and mixtures of dimethylacetamide and dimethylformamide in a major amount and a polyalkylene glycol having a molecular weight of not greater thann 2000 in a minor amount. The capacitor is adapted for use at a medium to high operating voltage and over a wide temperature range and to develop little or no gas even when operated at voltages above 200.

Abstract: Capacitance of anodized aluminum foil is increased by treating the foil after etching but before anodizing with an aqueous solution of a salt of valve metal, the oxide of which has a dielectric constant of at least about 20 and heating the foil to convert the salt to an oxide.

Abstract: An improved electrolytic capacitor is particularly useful for operation at voltages above 500 volts is produced by employing an electrolyte containing a straight chain saturated aliphatic dicarboxylic acid in which the carboxylic moieties are separated by at least 14 carbon atoms.

Abstract: Non-toxic aluminum electrode capacitors are provided in which the electrolyte is a solution in ethylene glycol of a neutralization product of about 1 mol of isophthalic acid or terephthalic acid and about 2 mols of a dialkylamine or piperidine.