Abstract: Disclosed is a method of making particle which comprise hydrous trivalent chromium oxide having the empirical formula CrO.sub.2 H intimately associated with a pulverulent carbonaceous substrate. A composition is formed which comprises an aqueous solution of water-soluble hexavalent chromium compound and a reducing agent in an amount sufficient to reduce the hexavalent chromium compound to the hydrous trivalent chromium oxide and to reduce the hydrous trivalent chromium oxide to metallic chromium. The reducing agent comprises a water-insoluble pulverulent carbonaceous substrate. Chrome metal can be made by heating the particles at a temperature of about 1100.degree. to about 1400.degree. C.

Abstract: 3,5-Diaminobenzotrifluoride can be readily separated from 4-chloro-3,5-diaminobenzotrifluoride by the addition of hydrogen chloride. 3,5-Diaminobenzotrifluoride forms hydrochloride salt, while 4-chloro-3,5-diaminobenzotrifluoride does so much less readily.

Abstract: p-Trifluoromethyl benzaldehydes are prepared by the catalytic reduction reaction of p-trifluoromethyl benzonitriles with hydrogen in an aqueous formic acid media in the presence of a nickel/aluminum alloy catalyst.

Abstract: Disclosed is a method of making chromic acid by electrolyzing an aqueous solution of sodium bichromate until the sodium bichromate is converted to chromic acid at a bichromate percent conversion of about 1 to about 48.4. Sulfuric Acid is then added to the aqueous solution in an amount between stoichiometric and about 30 wt % in excess of stoichiometric to convert the remaining sodium bichromate to chromic acid. This results in the precipitation of chromic acid, which is separated from the aqueous solution.

Abstract: This invention relates to novel fluorinated N,N-bis-imides of the formula ##STR1## wherein R is a bivalent radical of the formula ##STR2## The compounds are particularly useful as monomers in the preparation of high performance polymer.

Abstract: A process for the production of diaryl ethers which comprises heating, to a temperature of 80.degree. C. to 220.degree. C., a compound of the formula ##STR1## wherein X and Y are selected from the group consisting of H, CN, CO.sub.2 H, CHO, NO.sub.2, and CF.sub.3, provided that both X and Y may not simultaneously be H, in a solvent, in the presence of an inorganic base selected from the group consisting of the alkali metal carbonates, bicarbonates, and hydroxides, and in the presence of a catalyst selected from the group consisting of benzoic acid, substituted benzoic acids, C2-C4 aliphatic carboxylic acids, and alkali metal salts of said acids.

Abstract: Disclosed is a method of removing sulfate ion from an aqueous sodium chlorate liquor. A crystallization temperature is selected between about -15.degree. and about 0.degree. C. and the maximum concentration of sodium chlorate that is soluble in the liquor at that temperature is determined. The liquor is diluted so that the concentration of sodium chlorate in the liquor is less than that miximum concentration and the liquor is cooled to that temperature so that the sulfate ion in the liquor crystallizes as sodium sulfate decahydrate but the sodium chlorate does not crystallize.

Abstract: Disclosed is an improved method of operating a sodium chlorate crystal production system where a brine stream is electrolyzed to form sodium chlorate, the sodium chlorate is crystallized in a crystallizer, and the mother liquor from a crystallizer is recycled to the brine stream. The improvement comprises passing the mother liquor through a cationic chelating ion exchange column before it is returned to the brine stream, and operating the ion exchange column so that it removes, on the average, only the amount of calcium that enters the system in the brine stream.

Abstract: Disclosed is a solution in butyrolactone of a diglyme-insoluble polyimidesiloxane. The polyimidesiloxane is the reaction product of a dianhydride selected from the group consisting of 3,3',4,4'-benzophenone tetracarboxylic acid dianhydride, 3,3',4,4'-oxydiphthalic anhydride, and mixtures thereof, with a mixture of a non-siloxane diamine and a siloxane diamine in a molar ratio of about 0.1 to about 16, where said non-siloxane diamine is selected from the group consisting of 2,4-diaminotoluene, 3,5-diamino-tert-butylbenzene, 2,5-diamino-trifluoromethyl benzene, 2,6-diamino-4-trifluoromethyl pyridine, and mixtures thereof.

Abstract: Novel halogenated polyimides and co-polyimides comprise recurring imide structural units of the formula ##STR1## where X is F, Cl, Br or I; Y is H, F, Cl, Br or I; and R is a divalent organic radical.

Abstract: Disclosed is a composition of about 25 to about 85 wt % perchloroethylene and about 15 to about 75 wt % monochlorotoluene. When the composition contains at least about 30 wt % perchloroethylene it does not display a flash point.

Abstract: Dioxydiphthalic anhydride is prepared by the reaction of dihalophthalic anhydride with an alkali metal compound, such as potassium carbonate. The compound is particularly useful as a monomer in the preparation of polyimides.

Abstract: Plychlorophthalimides, specifically, N-substituted tetrachlorophthalimides and N-substituted trichlorophthalimides may be treated with zinc and a base in aqueous soluction to yield, after acidification, the product 3,5-dichlorophthalic acid or salts thereof.

Abstract: Disclosed is a process for treating a waste stream containing calcium sulfate by depositing said waste stream on a gypstack, collecting the leachate from the gypstack, and recovering the P.sub.2 O.sub.5 values therefrom. Also disclosed is apparatus comprising means for depositing a waste stream containing calcium sulfate on a gypstack, means for collecting the leachate from the gypstack, and means for recovering the P.sub.2 O.sub.5 values therefrom. Preferably, at least about 25% of the calcium sulfate is calcium sulfate hemihydrate.

Abstract: Biphenyl tetracarboxlic acid esters and derivatives thereof are prepared by the coupling reaction of 4-halogen substituted o-benzenedicarboxylic acid ester, carried out in an aprotic polar solvent in the presence of a pre-prepared triphenylphosphine-nickel chloride or trialkylphosphine-nickel chloride catalyst, zinc powder as the reducing agent, and an alkali metal halide promoting agent. The ester may be hydrolyzed in basic solution to afford the corresponding acid. The acid may be heated or boiled with acetic anhydride to afford the biphenyl dianhydride.

Abstract: Disclosed is a device that can be placed on the lever arm of a switch and locked to prevent the switch from being turned on. The device comprises a rigid body having a clasping device for removably fixing the rigid body to the lever arm, an aperture through the rigid body in which the shackle of a lock can be placed, positioned so that when the shackle is in the aperture access to the clasping device is blocked, and a bracing portion which contacts the switch to prevent its lever arm from being rotated when the device is attached thereto.

Abstract: Substantially fully imidized polyimidesiloxanes which are based on a selected pyridine compound are soluble in diglyme which gives them particular utility in the micro-electronics industry. The polymers are prepared from the dianhydride, a difunctional siloxane monomer and an organic dimaine that has the formula ##STR1## wherein X is hydrogen, halide, phenyl, or combinations thereof ##STR2## The preferred dimaine has the formula ##STR3## Other diamines can be used to provide an asymmetrical structure in the polyimidesiloxane polymer chain. The polyimidesiloxane can be prepared with functional groups which render them directly curable. The polyimidesiloxane can also be prepared with functional groups which when reacted with an unsaturated compound renders the polymers curable. The products of the invention can be used in the form of solutions in the micro-electronic industry. The polymers can also be used in wire and cable coating and to prepare films, fibers, and molded and extruded articles.

Abstract: A co-polyimide based upon a mixture of 4,4'-oxydiphthalic dianhydride (ODPA) and 3,4,3',4'-biphenyltetracarboxylic dianhydride (BPDA) as the dianhydride component and either 4,4'-oxydianiline (ODA) or paraphenylene diamine as the amine component is disclosed. The molar ratio between the ODPA and BPDA ranges from 3:1 to 1:3. The co-polyimide may either be formed as a random copolymer, or as a block copolymer where the blocks are based upon blocks of polymer containing ODPA and blocks of polymer containing BPDA provided that the molar ratios of ODPA and BPDA are in the ratio of 3:1 to 1:3.

Abstract: Phenolic molding compositions, particularly useful as sheet molding compositions comprise: 1) a resole phenole resin, 2) a thickening agent selected from the group consisting of alkaline earth metal oxides or hydroxides and silanes, 3) a filler selected from the group consisting of clay, talc, and mixtures thereof, and 4) an epoxy resin.

Abstract: Substantially fully imidized polyimidesiloxanes which are based on a selected pyridine compound are soluble in diglyme which gives them particular utility in the micro-electronics industry. The polymers are prepared from the dianhydride, a difunctional siloxane monomer and an organic diamine that has the formula ##STR1## wherein X is hydrogen, halide, phenyl or combinations thereof, Z=--O--, --S--, ##STR2## >C(CX.sub.3).sub.2, --, or --Y--Ar--Y--. Ar= ##STR3## Y=--O--, --S--, ##STR4## >C(CH.sub.3).sub.2, or --. n=0 or 1.The preferred diamine has the formula ##STR5## Other diamines can be used to provide an asymmetrical structure in the polyimidesiloxane polymer chain. The polyimidesiloxane can be prepared with functional groups which render them directly curable. The polyimidesiloxanes can also be prepared with functional groups which when reacted with an unsaturated compound renders the polymers curable.