Sprague Electric Company

Sidney D Ross

Manuel Finkelstein

Franz S Dunkl

Galeb H Maher

Walter J Bernard

Clinton E Hutchins

George A Shirn

Andrew E Dequasie

Raynor Linzey

Shirley A Hart

Philip G Russell

John E Barry

Franz C Dunkl

Highly conducting polyaniline is produced in situ in a tantalum capacitor by subjecting an excess of monomeric aniline to a solution having a low concentration of ammonium persulfate reagent. The monomer is oxidized by the reagent in preference to the polymer, so that the presence of excess monomer protects the polymer as it is produced against further oxidation to a less conductive species.

Method of making polyaniline solid electrolyte capacitor

A phthalate electrolyte containing benzil provides aluminum electrolytic capacitors having low equivalent series resistance and low rates of change in equivalent series resistance with time on voltage.

Low resistivity low ESR capacitor electrolyte

An electrolytic capacitor employs an electrolyte having amic acid salts prepared in situ in the electrolyte by reacting a cyclic anhydride with ammonia or an amine in an aprotic solvent acting as an acceptor in hydrogen bonding and thereafter adding glycol.

Capacitor electrolyte and process therefor

Dried emulsion of precursors for ceramic additives are added to paints containing fine particle ceramic materials for use in ceramic capacitors. The precursors are converted into the desired additives in the paints during the sintering of the capacitor bodies.

Dried emulsion ceramic process

A filtered solution of barium hydroxide octahydrate reacted with an aqueous solution of boric acid to provide hydrated .gamma. barium borate having a barium to boron ratio of 1:2 and having fine particle size. The hydrated .gamma. barium borate was converted to the anhydrous .gamma. form at about 300.degree. to 400.degree. C. Further heating to about 600.degree. to 800.degree. C. converted the product to .beta.-BaB.sub.2 O.sub.4. The conversion to the .beta.-form is preferably during sintering of a ceramic dielectric composition to which the .gamma.-BaB.sub.2 O.sub.4 has been added as a flux.

Barium borate preparation

Water soluble precursors of ceramic compounds are emulsified in an organic fluid containing an organic surfactant. The emulsion is subsequently mildly heated at a pressure of about 0.05 atmospheres to remove the free water from the emulsion droplets. The resulting sludge consists of particles deriving from the dehydrated emulsion droplets. These particles may only be bound by the surfactant, all or most of the original organic fluid having been boiling off under low pressure. This sludge is then heated in a standard air atmosphere to char the surfactant, which char is to maintain the separation between the dried droplet-derived particles to prevent forming sintered or fused agglomerates thereof. With continued heating the transient char is subsequently burned off and the particles are calcined to controllably and simply produce a fine ceramic powder of spherical particles having a narrow size distribution and an average size in the particularly useful range of 0.1 micron to 1.0 micron.

Emulsion-char method for making fine ceramic powders

An aluminum electrolytic capacitor has a wound foil section with cellulosic spacer material, interleaved between and contiguously wound with the foils, loaded with 1 to 6 wt % of a synthetic hydrotalcite. The spacer material may be Manila, Kraft or Benares paper.

Electrolytic capacitor and spacer therefor

In an aluminum foil electrolytic capacitor, the anode foil bears both a layer of hydrous aluminum oxide and a layer of barrier dielectric oxide and is in contact with an electrolyte containing as additives up to 5 wt % depolarizer and sufficient soluble phosphate salt to restore the desired anodization voltage.

Aluminum electrolytic capacitor

An aluminum electrolytic capacitor has a capacitor section of two aluminum electrode foils, at least one of which bears a barrier layer anodic oxide, wound with interleaved spacer material in contact with an electrolyte containing a phosphate salt, the cation of which is compatible with the cation of the electrolyte solute to prevent precipitation of a phosphate.

An aluminum electrolytic capacitor capable of operation at 150 VDC or higher and 105.degree. C. contains as its electrolyte a diisopropylamine or a triethylamine mono salt of azelaic acid dissolved in a solvent mixture of ethylene glycol, ethylene glycol and N-methylpyrrolidinone, ethylene glycol N-methylpyrrolidinone and dimethylformamide, butyrolactone, or butyrolactone and N-methylpyrrolidinone, all containing small amounts of water.

Electrolytic capacitor for at least 150 V service

An aluminum electrolytic capacitor contains as electrolyte 79-95 wt. % of an azeotrope of acetic or propionic acid and triethylamine or tri-n-propylamine, 5-20 wt. % water, and up to 1 wt. % phosphoric acid.

Electrolytic capacitor

A high-temperature aluminum electrolytic capacitor contains an electrolyte of a salt of tert.butylamine and adipic acid in a 1.3 to 2.0 amine:acid molar ratio, a phosphate salt, and water dissolved in ethylene glycol to provide a capacitor capable of operating at least at 200 VDC and 130.degree. C.

High temperature electrolytic capacitor

An AC metallized film capacitor having a plurality of electrodes separated by a dielectric spacer contains as its impregnant system an ester dielectric fluid and 2 to 10% of a N,N-substituted carbodiimide to improve capacitance retention characteristics.

AC Metallized capacitor and impregnant therefor

An electrolytic capacitor contains an electrolyte solvent system in which one component is an acceptor in hydrogen bonding while the other component is one that can function both as acceptor and donor in hydrogen bonding. The solute or solutes present must not interact with either solvent component. When the above conditions are met, the result is an electrolyte whose resistivity curve passes through a minimum.

Electrolytic capacitor containing a mixed solvent system

An AC metallized film capacitor having a plurality of electrodes separated by a dielectric spacer contains a dielectric fluid and 2 to 10% of .alpha.-naphthyl isocyanate as impregnant system to scavenge moisture and to improve capacitance retention.

Growing community of inventors

Williamstown, MA, United States of America

Sidney D Ross