Abstract: An acrylonitrile based fiber is disclosed which is composed of copolymers comprising at least 96 mole % of acrylonitrile and 1.times.10.sup.-2 to 70.times.10.sup.-2 mole % of a vinyl component or vinyl components containing acidic groups, and containing a specific amount of zinc. The fiber is used in production of oxidized or flame resistant fiber. The oxidized or flame resistant fiber is produced by heat-treating or oxidizing the acrylonitrile based fiber in an oxidation furnace equipped with a plurality of roller units while limiting the shrinkage of the acrylonitrile based fiber within specific limits as the oxidation proceeds. On carbonizing the above oxidized or flame resistant fiber while limiting the shrinkage thereof a carbon fiber which is of high strength and low fluffing is obtained.
Abstract: New zeolite materials designated Nu-6(1) and Nu-6(2), having molar compositions expressed by the formula:0.5 to 1.5 R.sub.2 O:Y.sub.2 O.sub.3 :at least 10 XO.sub.2 :0 to 2000 H.sub.2 Owherein R is a monovalent cation or .sup.1 /n of a cation of valency n, X is silicon, and/or germanium, Y is one or more of aluminum, iron, chromium, vanadium, molybdenum, antimony, arsenic, manganese, gallium or boron, and H.sub.2 O is water of hydration additional to water notionally present when R is H and having defined X-ray diffraction patterns, are prepared from a reaction mixture containing XO.sub.2 (preferably silica), Y.sub.2 O.sub.3 (preferably alumina) and a 4,4'-bipyridyl compound. At temperatures of 200.degree. C. or higher, Nu-6(1) is converted to Nu-6(2), a useful catalyst for xylenes isomerization and the like.
Abstract: An acoustic vibrating element, such a domed speaker diaphragm A or a phonographic pickup cantilever B, is formed by vapor deposition on an easily separable mold member 5 of tantalum or tantalum alloy when a mixture of a hydrocarbon gas and an inert gas is passed through a furnace heated to a temperature of 1150.degree. C.-1250.degree. C. at a flow rate in excess of 200 cm/min. The c-axis crystalline orientation of the resulting graphite element is substantially perpendicular to its surface, which provides a Young's modulus above 16,000 Kg/cm.sup.2.
Abstract: Crystalline silicate particles having an aluminum-containing isostructural outer shell. The particles are prepared by first crystallizing crystalline silicate particles from a first reaction medium and thereafter crystallizing an isostructural outer shell onto said crystalline silicate particles from a reaction medium containing an increased source of aluminum.
Abstract: In the preferred embodiment, graphite fibers that are 5 to 15 microns in diameter and up to several centimeters long are grown within a thin-walled stainless steel tube by flowing natural gas through the tube, concurrently contacting the outer tube surface with wet hydrogen gas and heating to between 925.degree. C. to 1075.degree. C. to decompose methane in the natural gas to grow fibers on the inner surface of the tube.
Abstract: A new and useful improvement in the method for preparing synthetic crystalline aluminosilicate zeolite ZSM-12 is provided. The improved method comprises synthesizing ZSM-12 in the presence of cyclic quaternary amine halides as templates rather than the conventional template of tetraethylammonium.
Abstract: Crystalline aluminosilicate molecular sieves are formed by (1) forming an aqueous mixture of an oxide of aluminum, an oxide of silicon, a metal or ammonium cation and 2-aminopyridine organic template compound, (2) maintaining the pH of such mixture between about 9 and 13.5, and (3) crystallizing the mixture.
Abstract: Fibrous PAN material in raw or oxidized form is purified of alkali metals, particularly sodium, and alkaline earth metals by treating with an aqueous acid solution such as hydrochloric acid having a concentration of at least 0.5% by weight and preferably at least 3% and a temperature greater than 100.degree. F. and preferably at least 125.degree. F. but not greater than the temperature at which the aqueous acid solution boils, for 5-120 minutes and preferably at least about 15 minutes. An ion exchange occurs between the acid and the PAN material, and alkali and alkaline earth metal salts are formed. The PAN material is then rinsed in solvent such as deionized water which is substantially free of metallic ions at a temperature which is preferably at least about 150.degree. F.
Type:
Grant
Filed:
April 14, 1980
Date of Patent:
June 14, 1983
Assignee:
Hitco
Inventors:
Gary D. Shepherd, Ramon B. Fernandez, Ian R. Rule
Abstract: A series of transition metal complexes, having stability at relatively high pH, have been utilized as templates for the synthesis of ZSM-5 type zeolites.
Abstract: A solid product resulting from the nucleated growth of the product on solid material of either the same or different composition and having a density higher than the reaction medium is formed from one or more liquid phase reactants by a method which comprises tangentially introducing the liquid phase reaction medium into the lower, smaller end of an inverted, frusto-conical reactor-separator, thereby imparting an upward swirling motion to the reaction medium in the reactor-separator, the horizontal velocity at the bottom of the reactor-separator being sufficiently large to cause fluidization of larger, solid product particles and concentration of them in the central lower portion of the reactor-separator and the vertical velocity at the top of the reactor-separator being sufficiently small to avoid carry-over of the smaller solid particles but sufficiently large to concentrate them in the upper portion of the reactor-separator; at least periodically recovering the larger, solid product particles in spherical
Abstract: This invention relates to a method of carbonizing polyacrylonitrile fibers (PAN fibers) by exposing the fibers at an elevated temperature to an oxidizing atmosphere, then exposing the oxidized fibers to an atmosphere of an inert gas such as nitrogen containing a carbonaceous material such as acetylene. The fibers are preferably treated with an organic compound, for example benzoic acid, before the exposure to an oxidizing atmosphere. The invention also relates to the resulting fibers. The treated fibers have enhanced tensile strength.
Type:
Grant
Filed:
July 10, 1981
Date of Patent:
May 24, 1983
Assignee:
The United States of America as represented by the Administrator of the National Aeronautics and Space Administration
Inventors:
Domenick E. Cagliostro, Narcinda R. Lerner
Abstract: An anhydrous white kaolin clay pigment is disclosed, which consists of porous aggregates of kaolin clay platelets. The pigment exhibits exceptionally high light-scattering ability when incorporated as a filler in paper. The aggregates have an average specific gravity in the range of 0.5 to 0.6, and a size distribution such that not more than 5% by weight thereof are of greater than 10 microns ESD, at least 75% are of less than 2 microns ESD, and not more than 15% are of less than 1 micron ESD. The pigment has a Valley abrasion value below 30 mg, and preferably below 20 mg, and a GE brightness of at least 93. The mean size of the internal pores in the aggregates is less than 0.55 microns and preferably is less than 0.5 microns. This low mean pore size is deemed instrumental in producing the aforementioned high scattering ability. A method for producing the said pigment is also disclosed and claimed.
Abstract: A process for producing a carbon fiber tow from an acrylic fiber tow wherein the acrylic fiber tow is treated to uniformily contain throughout the two (1) an aminosiloxane and (2) a chemical substance selected from glycerine, an alkylene glycol, and a polyalkylene glycol prior to heat-treating said acrylic fiber tow to produce the carbon fiber tow whereby problems such as fluffiness, spreading, and filament breakage are diminished.
Type:
Grant
Filed:
April 7, 1982
Date of Patent:
March 29, 1983
Assignees:
Sumitomo Chemical Co., Ltd., Japan Exlan Co., Ltd.
Abstract: Crystalline aluminosilicate molecular sieves are prepared by (1) forming an aqueous mixture of an oxide of aluminum, an oxide of silicon, a metal or ammonium cation and a suitable oxygen-containing monomeric organic template compound, (2) maintaining the pH of such mixture between 9 and 14, and (3) crystallizing the mixture. The organic templates include ethanolamine, diethanolamine, triethanolamine, ethylethanolamine, ethyldiethanolamine, 2-amino-2-ethyl-1,3-propanediol, morpholine, and alkali metal complexed tetrahydrofuran, dioxane, dioxolane, and crown ethers. Crystalline aluminosilicates prepared include mordenite, ferrierite, ZSM-4, and ZSM-5.
Abstract: A diamond powder is produced by a shock compressing method using a carbon precursor obtained by an organic compound such as furan resin, its derivative, a thermosettable resin, as a carbon source.
Type:
Grant
Filed:
December 18, 1981
Date of Patent:
March 22, 1983
Assignee:
National Institute for Researches in Inorganic Materials
Abstract: New crystalline silicate compositions are prepared from a silica containing mixture which is substantially free of aluminum ions and contains a source of choline by digesting a reaction mixture comprising a choline salt, sodium hydroxide, potassium hydroxide, an oxide of silicon, water and, optionally, a Group VIII metal salt with the reaction mixture containing less than about 1000 ppm aluminum. These crystalline silicates exhibit a distinctive X-ray diffraction pattern and have a composition as expressed in terms of its oxides, as follows: ##EQU1## where R is the organic nitrogen-containing cation derived from choline, M is an alkali metal ion, ammonium, hydrogen, a metal cation or mixtures thereof, m is the valence of M, Z is a Group VIII metal cation and z is the valence of said Group VIII metal cation. These crystalline silicates are usefully employed as catalysts in hydrocarbon conversions.
Type:
Grant
Filed:
April 22, 1981
Date of Patent:
March 15, 1983
Assignee:
National Distillers & Chemical Corp.
Inventors:
James A. Hinnenkamp, Vernon V. Walatka, Jr.
Abstract: Crystalline aluminosilicates having a high silica to alumina molar ratio are prepared by mixing a source of silica, a source of alumina, a source of alkali metal, water and one or more substituted neopentylamines having the formula: ##STR1## wherein R.sup.2 is H, OH or NH.sub.2 and R.sup.1 is a C.sub.1 to C.sub.6 alkyl group, and maintaining the mixture under conditions of elevated temperature and pressure, typically in the range from 80.degree. to 210.degree. C. and autogenous pressure for a time sufficient to effect formation of the aluminosilicate, typically not less than 4 hours. The molar ratio of silica to alumina in the initial mixture is suitably in the range from 10:1 to 150:1 and the amounts of alkali metal and neopentylamine are suitably in the range from 2:1 to 0.02:1 and 10:1 to 0.02:1 respectively moles per mole equivalent of total silica and alumina in the respective sources.
Abstract: A Y-type zeolite having a SiO.sub.2 /Al.sub.2 O.sub.3 ratio of at least about 4 is produced by the following process. In the first step of the process, an aqueous alkali silicate solution and an aqueous alkali aluminate solution are mixed together in the presence of an alkali in an amount such that the ratio of M.sub.2 O(M: an alkali metal)/Al.sub.2 O.sub.3, present in the mixed solution, is at least about 5 by mole, followed by forming a gel in the mixed solution and, then, separating the gel therefrom. In the second step, the separated gel is incorporated in an aqueous alkali silicate solution or an aqueous alkali silicate-alkali mixed solution to obtain a slurry and, then, a Y-type zeolite crystal is formed in the slurry.
Abstract: The invention provides a method of making large crystallite zeolites by a method comprising forming the zeolite in a medium containing a combination of two different alkylammonium cations or a combination of an alkylammonium cation and a metallic cation. In the combination at least one of the cations will have an ionic radius of from about 1.40 to the pore size of the specific zeolite.
Type:
Grant
Filed:
September 23, 1981
Date of Patent:
March 1, 1983
Assignee:
Mobil Oil Corporation
Inventors:
Francis G. Dwyer, Pochen Chu, William E. Cormier, Jr.
Abstract: An improved continuous hot gas surface modification process for carbon fibers is provided. The carbon fibers undergoing such processing are passed for a relatively brief residence time through a surface treatment zone to which continuously is fed nitrogen dioxide and air under conditions which have been found to produce a surprisingly effective surface modification. The resulting carbon fibers exhibit a significantly enhanced surface area and an improved ability to bond to a resinous matrix material while retaining a substantial portion of the tensile strength originally exhibited. When incorporated in a resinous matrix material, a fiber reinforced composite article of enhanced interlaminar shear strength is formed.
Type:
Grant
Filed:
January 5, 1981
Date of Patent:
February 15, 1983
Assignee:
Celanese Corporation
Inventors:
Sang N. Kim, Paul E. McMahon, John P. Riggs, John M. Rhodes