Abstract: A composition comprising .alpha.-alumina in a concentration of at least 99.95 weight percent and process for producing such .alpha.-alumina wherein alumina having an alkali metal content between 0.05 and 0.60 weight percent and Al.sub.2 O.sub.3 content of more than 95 weight percent is electrically fused with silica and additional alkali, if desired, in an electric arc furnace, the heated composition is cooled, comminuted and the so-formed glass phase is removed from an alumina containing phase by mechanical or chemical means.

Abstract: A projectile, especially for hand and long firearms, including a projectile body having a longitudinal axis, a front face and a rear face, a deformation cavity extends partially into the projectile body at the front face thereof and a continuous axial bore is provided in the projectile body in communicating relationship with the rear face and the deformation cavity. The projectile body has a wall thickness in the region surrounding the deformation cavity which is smaller than the wall thickness in the region surrounding the axial bore. A cap is initially disposed in the region of the front face of the projectile body for covering at least the deformation cavity, the cap being separated from the projectile body within the barrel of the firearm during firing of the projectile and exiting from the barrel in front of the projectile body.

Abstract: An improvement in the process for the esterification of chlorosilanes with alcohols wherein the esterification is carried out in the presence of a chlorohydrocarbon and in the absence of an acid binding agent.

Abstract: Propellant charge device for recoilless weapons of the type having a barrel open at both ends with the propellant charge device being positioned behind a projectile and insertable into the front end of the barrel. The propellant charge device includes an elongated casing having a powder charge portion, a cavity portion and a tamp portion axially sequentially arranged within the casing and extending from the front to the rear thereof. The casing has a length such that it extends within the barrel of the weapon from the position thereof behind the projectile substantially over the entire length of the barrel.

Abstract: A hardenable molding composition containing a sulfochlorinated polyolefin or sulfochlorinated olefin copolymer and a crosslinking agent, said crosslinking agent being an organic derivative or mixture of organic derivatives of titanic acid, e.g., the reaction product of a titanic acid ester with a chelating agent such as a .beta.-dicarbonyl compound, an acetic acid ester or a polyhydroxy compound. Molding compositions of the invention can contain conventional additives, fillers, solvents, plasticizers, flameproofing agents, thixotropic agents and/or adhesivizing agents and the like.

Abstract: An iron oxide pigment having a coating of a silane of the formulaR.sub.n Si(OR').sub.4-nwhereinR is an, in some cases, branched or oxygen-bridge-containing alkyl or alkenyl moiety of 1 to 18 carbon atoms, or an aryl moiety,R' is an, in some cases, branched and, in some cases, oxygen-bridge-containing alkyl moiety of 1 to 8,N=1 to 3,Or a hydrolysis product thereof; a magnetic tape containing such coated iron oxide pigment and a process for coating such iron oxide pigment. There is particularly disclosed the treatment of iron oxide magnetic pigments to thereby improve their wear resistance and dispersibility in organic mediums.

Abstract: Foamed phenolic resins containing CaSO.sub.4. nH.sub.2 O, where n is 0-2, having reduced tendency to shrink and reduced weight loss on aging.

Abstract: A sensor for rocket engines having at least one combustion chamber including a pressure-sensitive sensing device responsive to pressure in the combustion chamber for providing an output signal to a control device in response to the pressure in the combustion dropping below and/or rising above at least one predetermined pressure. The pressure-sensitive sensing device includes a piston arranged for displacement between first and second positions. The piston is displaceable from at least the first position to the second position in response to a first predetermined pressure value in the combustion chamber. A restoring force is effective for displacing the piston from the second position toward the first position in accordance with a second predetermined pressure value in the combustion chamber. The piston is arranged for triggering a signal in at least one of the first and second positions thereof.

Abstract: An improvement in a process for preparing a xylene chlorinated in the nucleus by contacting the xylene with chlorine in the presence of a catalyst, the improvement residing in employing as the catalyst an iron halide or antimony halide and employing a co-catalyst which is an aliphatic, halogenated or nonhalogenated hydrocarbon having an oxygen function.

Abstract: A process for producing a continuous foam sheet of a synthetic resin having a polyolefin base which comprises admixing an organic peroxide, a blowing agent, and a pore regulator with the synthetic resin, finely distributing said peroxide, blowing agent and pore regulator within said resin at a temperature below the decomposition temperature of the peroxide and the blowing agent in the thermoplastic range, shaping the resulting admixture into a sheet or panel and thereafter effecting thermal crosslinking and foaming of the resin. The pore regulator comprises an oligomeric and/or polymeric saturated dicarboxylic acid ester or a mixture of such esters having average molecular weights of from between 500 and 40,000, and flow points and/or melting ranges that are below the decomposition temperature of the peroxide and of the blowing agent.

Abstract: A process for preparing a poly-(alkylpentamethyleneterephthalamide) which comprises heating an aqueous solution of the corresponding nylon salt and still water soluble low molecular weight oligomer, the mixture of nylon salt and oligomer having 20 to 50 mole percent carbonamide groups and 50 to 80 mole percent salt groups, from a temperature at least as low as 150.degree. C. at atmospheric pressure up to a polycondensation temperature of at least 250.degree. C.

Abstract: A process for preparing a filler-fortified polyalkyleneterphthalate molding composition which comprises mixing a filler with a precondensate of poly-(1,4-butylene)-terephthalate and/or poly-(1,3-propylene)-terephthalate, forming the resultant mixture into a shape and thereafter polymerizing the precondensate by solid-phase condensation under solid-phase condensation conditions; a molding composition prepared by such a process comprising poly-(1,4-butylene)-terephthalate and/or poly-(1,3-propylene)-terephthalate in an amount of 20 to 98 weight percent and 2 to 80 weight percent of a fortifying filler, the amounts based upon the combined amount of polyester and fortifying filler; a shaped object prepared from molding such a molding composition and the process for molding such a molding composition into a molded shaped article.

Abstract: A mounting disk arrangement is provided for the fixation of loosely installed sealing sheets of a synthetic resin, wherein the mounting disk is attachable to a substrate, such as a substrate on a roof, for example a trapezoidal roof, by means of a screw passed through the mounting disk. In order to prevent unturning of the screw, a blocking mechanism in the form of a member attached to the mounting disk and engageable in the screw slots of the screw is provided. In preferred embodiments, the blocking apparatus consists of a leaf spring, while other embodiments include plate members attached to the mounting disk.

Abstract: In a process for preparing a halogen alkyl silane by contacting an alkyl silane of the formulaR.sub.n SiR'.sub.4-nwhereinR represents a substituted or unsubstituted alkyl or alkenyl group,R' represents an alkyl group, andN represents 0, 1, or 2With a hydrogen halide in the presence of a catalyst, the improvement which comprises employing as the catalyst an aluminum oxide-containing composition.

Abstract: A pyrotechnical sealing material comprises a heat-foamable synthetic resin capable of being foamed with the aid of a burnable pyrotechnical composition. The sealing material is in the form of a cord having a core made of the pyrotechnical composition and a casing separated from the core by a flexible sheath. The casing is formed from the heat-foamable synthetic resin.

Abstract: A ceramic molding composition comprising an alcoholate of aluminum or a metal of the fourth sub-group of the Periodic System, a refractory metal oxide and an agent selected from the group consisting of diketones of the formula ##STR1## wherein R.sub.1 and R.sub.2 are each independently an aliphatic radical of between C.sub.1 and C.sub.18 carbon atoms or an aromatic radical from C.sub.6 to C.sub.18 carbon atoms, a hydroxycarboxylic acid compound of the formula ##STR2## wherein R.sub.3 is an aliphatic radical of C.sub.1 and C.sub.18 or an aromatic radical from C.sub.6 to C.sub.18, and R.sub.4 is hydrogen or an alkyl radical of C.sub.1 to C.sub.4, and a polyvalent alcohol, an improvement in the formation of a ceramic product wherein a ceramic molding composition is shaped and hardened, which improvement resides in employing the above defined ceramic molding composition.

Abstract: Process of preparing an .alpha.,.beta.-unsaturated carboxylic acid ester, comprising contacting an .alpha.,.beta.-unsaturated halogen compound with carbon monoxide, an alkali alcoholate in the presence of a metal carbonyl as catalyst, in an alcohol that is the basis of the alkali alcoholate, at a pH of 8.5-11.5. Thereby, for example, crotonic acid methyl ester can be produced from allyl chloride.

Abstract: An improved process for grafting vinyl chloride onto ethylene-vinyl acetate or ethylene-alkyl acrylate copolymers in the gel phase in the presence of radical formers soluble in the monomer wherein the ethylene-vinyl acetate or ethylene-alkyl acrylate copolymer is in powder form and a combination of at least two initiators having different decomposition temperatures are employed during the grafting, the resultant grafted copolymer and the use of the same as an impact strength improving component or polyvinyl chloride or vinyl chloride copolymers.

Abstract: The invention relates to halogenous polyesters with the recurrent general formula ##STR1## in which at least part of the R's, e.g.

Abstract: An apparatus for the tensioning and relaxing of a safety belt including an elongated housing, a tensioning piston, and a tie rod for connection with the safety belt and arranged for retraction relative to the housing in response to pressure on the tensioning piston as well as being arranged thereafter for extension relative to the housing with a delay in response to tensile stress on the safety belt. A hydraulic damping arrangement including a damping cylinder containing a liquid and damping piston coupled with the tensioning piston is provided for forming a telescopic arrangement such that after the tensioning piston effects the retraction of the tie rod and reaches an arrested retracted position thereof, the hydraulic damping arrangement enables damped extension of the tie rod relative to the housing by displacement of the damping piston which in turn displaces liquid in the damping cylinder in response to tensile stress on the safety belt.