Abstract: Polyimide foam of desired density is produced by adding to a polyimide precursor comprising carboxylic and diamine components at least one foam-enhancing polar, protic additive of the formula ROH, where R is hydrogen, or C.sub.1 to C.sub.12 linear or branched alkyl or cycloalkyl, unsubstituted or substituted with halo, aryl, alkoxy or hydroxy, and heating the resultant slurry to a temperature that does not exceed about 105.degree. C. to form a homogeneous melt. When heated to a higher temperature the melt foams and cures. The density of the foam is affected by the amount of foam-enhancing additive which is utilized.
Type:
Grant
Filed:
August 31, 1990
Date of Patent:
March 17, 1992
Assignee:
Ethyl Corporation
Inventors:
James R. Barringer, H. Eugene Broemmelsiek, Carroll W. Lanier, Raymond Lee
Abstract: Composition of heterohalogenated cyclododecatriene (e.g. C.sub.12 H.sub.18 Br.sub.x Cl.sub.y) are disclosed and methods for preparation thereof.
Abstract: A flame retardant product predominant in hexabromocyclododecane is prepared and dried by a process wherein gaseous ammonia is injected into the dryer system to prevent the formation of color bodies which contaminant the product.
Type:
Grant
Filed:
November 15, 1990
Date of Patent:
December 31, 1991
Assignee:
Ethyl Corporation
Inventors:
George W. Cook, Jr., George H. Ransford
Abstract: This invention relates to a method for rendering explosives and weapons radio-opaque so as to allow their detection by low level x-ray machines.
Abstract: In humid atmospheres (e.g., 40% relative humidity or above) solutions of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride/2,2-bis[4-(aminophenoxy)phenyl]hexafluoropropane polyimides tend to be unstable in the sense that during spin coating operations undesirable precipitate formation occurs on the rotating surface of the wafer. The result is the formation of unacceptable coatings due to their irregularity and lack of uniformity. Described are solutions of these polyimide polymers in a solvent containing one or more liquid aromatic hydrocarbons having a boiling point at least about 110.degree. C. and one or more dipolar aprotic solvents having a boiling point of at least about 150.degree. C., such that the solution (a) contains on a weight basis from about 5% to about 50% of the polyimide, and (b) does not undergo precipitate formation during spin coating in an atmosphere of up to about 55% relative humidity.
Abstract: In humid atmospheres (e.g., 55% relative humidity or above) solutions of 2,2-bis(3,4-dicarboxyphenyl)hexafluoropropane dianhydride/2,2-bis[4-(aminophenoxy)phenyl]hexafluoropropane polyamic acid polymers tend to be unstable in the sense that during spin coating operations undesirable precipitate formation may occur on the rotating surface of a semiconductor wafer. The result is the formation of unacceptable coatings due to their irregularity and lack of uniformity. Described is a method of spin coating solutions of these polyamic acid polymers in a solvent containing one or more cycloaliphatic ketones, such that the solution (a) contains on a weight basis from about 5% to about 40% of the polyamic acid and (b) does not undergo precipitate formation during spin coating in an atmosphere of up to at least about 55% relative humidity.
Abstract: This invention provides a tibial prosthesis for use during a total knee arthroplasty procedure which includes a modular tibial component comprising an in-bone anchorage assembly to which is removably attached a tibial tray adapted to receive and retain a variety of femoral components or bearing inserts. Removal of the tray permits access to the interface between the bone and anchorage assembly in the event removal or revision are necessary. In preferred embodiments, the invention affords hybrid fixation of the tibial prosthesis in that bone cement for immediate fixation and adaptation for longer term bone ingrowth are featured.
Abstract: This invention provides an adjustable, removable, reusable masonry tool for retaining expansion material employed in concrete work. The tool includes a plurality of elongated, substantially U-shaped caps which retain the expansion material, the caps being slidably engaged together for adjustment of the tool's length.
Abstract: The removal of water vapor from a gas/vapor mixture by means of vapor permeation takes place by passing the mixture to be separated along one side of a membrane and the permeation of water vapor through the membrane is achieved by maintaining a relatively low partial pressure of water vapor on the other side of the membrane. To increase the flux the membrane is impregnated beforehand with a hygroscopic electrolyte.
Type:
Grant
Filed:
September 9, 1988
Date of Patent:
April 3, 1990
Assignee:
Nederlandse Organisatie voor Toegepast-Natuurwetenschappelijk Onderzoek TNO
Abstract: Filter device for removing entrained fine solid particles from a gas stream, comprising a charging system (12) and an electrified granular filter (11) downstream of the charging system which is formed by at least one layer (14) of granules of non electrically conducting material and means for forming an electric field across the granules, the granule layer (14) being formed by a self-supporting, highly porous body, such as a body constructed of granules which are sintered together to form a sintered self-supporting granule layer.
Type:
Grant
Filed:
January 10, 1989
Date of Patent:
February 6, 1990
Assignee:
Nederlandse Organisatie voor Toegepastnatuurwetenschappelijk Onderzoek TNO
Abstract: A membrane module for hyperfiltration or ultra filtration of liquid flows comprises a membrane envelope (1) spirally wound around a tube (4) provided with openings and the membrane layers of which are alternately kept at a distance from each other by retentate spacers and permeate spacers (2), which retentate spacers comprise relatively rigid rods or wires (3) extending parallel to the center line of the module. In order to obtain a very constant and defined geometry of the retentate flow channels and a favorable ratio between membrane surface and module volume, the width dimension of the rods measured perpendicular to the membrane layers is 0.5 to 2.5 mm and the distance between the rods is 4 to 12 times said width dimension. Said width dimension of the rods measured perpendicular to the membrane layers should be at least three times the diameter of the largest particles in the liquid flow to be filtered.
Type:
Grant
Filed:
September 9, 1988
Date of Patent:
October 10, 1989
Assignee:
Nederlandse Organisatie voor Toegepast-Natuurwetenschappelijk Onderzoek TNO
Abstract: A matrix septum material, especially useful in medical applications such as implantable drug delivery devices, is provided by retaining a penetrable, resilient, elastomer under compression between webs having peripheries which frame perforations to form individual, self-sealing cells in the matrix.
Abstract: A mechanical device for cleaning the bottom of a boat moored in a body of water includes a line with a central scrubber section, ends affixed above the boat's water line and means for urging the scrubber section upward. Passing the boat over the line forces the scrubber section against the bottom, cleaning it.
Abstract: A 2,2'-bridged[1,1'-biphenyl]-3-ylmethyl compound of the following formula is an intermediate to insecticidal esters. ##STR1## wherein n is 1-4 and Y is a leaving group readily displaced by carboxylate anions.
Abstract: Novel syntheses of dihalovinylcyclopropanecarboxylates, including potent insecticides, are described. The processes begin with the reaction between an alkenol and an orthoester to produce a .gamma.-unsaturated carboxylate, followed by the catalyzed addition of a carbon tetrahalide to the double bond and dehydrohalogenation to produce a cyclopropane derivative.
Abstract: In continuous operation of agitator mills, in particular when processing abrasive products, which operate with grinding bodies (35) in a grinding area, worn grinding bodies must be replaced. A grinding body feed device (9) which can be used for grinding bodies (35) of different shape and size comprises an intermediate chamber (43) from which the grinding bodies (35) pass from a storage vessel (33) into the grinding area without any material being ground getting into the storage vessel (33). The intermediate chamber (43) can be shut off at its inlet and its outlet in each case by means of a valve (19, 41; 47, 49), one of which is always closed during the introduction of grinding bodies (35) into a product supply pipe (45) leading to the grinding area.
Abstract: An implantable drug delivery depot has penetrable inlet means which define a first plane and anchor means which define a second plane. According to the invention, the first and second planes are substantially perpendicular. When the depot is implanted with the anchor means parallel to the skin surface, the inlet means is oriented so that a hypodermic needle penetrating the inlet means is nearly parallel to the skin surface, reducing the danger of dislodgement of the needle from the inlet.
Abstract: An improved process for the manufacture of herbicidal 2-[(2-chlorophenyl)methyl]-4,4-dimethyl-3-isoxazolidinone by cyclizing 3-chloro-N-hydroxy-2,2-dimethylpropanamide with an alkaline or alkaline earth hydroxide at a pH of 7.5 to 9.5, benzylating the resulting 4,4-dimethyl-3-isoxazolidinone, eliminating by-product 1-[(2-chlorophenyl)methoxy]-3,3-dimethyl-2-azetidinone by contacting the product mixture with anhydrous hydrogen chloride, and further benzylating free isoxazolidinone with base.
Type:
Grant
Filed:
February 14, 1986
Date of Patent:
May 3, 1988
Assignee:
FMC Corporation
Inventors:
Mariano A. Guiducci, Matthew I. Levinson
Abstract: Isoxazolidinones of the following formula are herbicides: ##STR1## or an agriculturally acceptable salt thereof in which R.sub.1 and R.sub.2 are independently selected from -hydrogen and-halogen; and R.sub.
Abstract: This invention is an improvement in an anchor for a transcutaneous conduit, such as a hypodermic needle, used in conjunction with a subcutaneous reservoir having a conduit-penetrable septum. The anchor includes a resilient protective boot having a plurality of concentric annular rings stacked using the conduit as an axis, beginning with a base ring carrying adhesive for attachment to the skin of a living body and ending with a terminal ring to be attached to the conduit, and includes means, when the terminal ring is attached to the conduit, to urge the protective boot into a compressed state along the axis and the conduit into the body. The improvement provides means for inserting a stylet into the anchor and through the conduit to prevent coring the septum when the conduit is inserted into the reservoir.