Abstract: A continuous, gas-assisted atmospheric process for preparing cyclic esters of alpha-hydroxycarboxylic acids, such as lactide, which comprises feeding the reactants into a reactor having means for introducing an inert gas at the operating temperature, forming a reaction mass having cyclic esters in the reactor, passing a flow of said inert gas through said reactor whereby cyclic esters are swept from the reaction mass into a gaseous product stream, and recovering the cyclic esters therefrom.
Abstract: The present invention relates to an adjustable length vehicle chassis having front and rear reach beams and a center beam, and in which the center beam is telescopically slidable into the reach beams and one reach beam is telescopically slidable into the other reach beam to attain minimum length adjustments of the chassis. One of the reach beams also includes a longitudinal slot extending substantially over its length to permit fractional length adjustments over a wide variety of lengths between maximum and minimum chassis lengths.
Abstract: An improved process for flash-spinning polyethylene plexifilamentary film-fibril strands is provided. The strand is flash-spun from a non-chlorofluorocarbon mixture of polyethylene, an organic solvent and water.
Abstract: An improved process for flash-spinning plexifilamentary film-fibril strands from fiber-forming polyolefins is provided. A polyolefin is mixed to form a solution of 18 to 33 percent polyolefin by weight of the solution, 42 to 73 perceny methylene chloride by weight of the solution and 9 to 25 percent carbon dioxide by weight of the solution. The mixture is then flash-spun into substantially dry plexifilamentary strands.
Type:
Grant
Filed:
July 24, 1989
Date of Patent:
August 27, 1991
Assignee:
E. I. du Pont de Nemours and Company
Inventors:
Don M. Coates, Gary S. Huvard, Hyunkook Shin
Abstract: Photohardenable electrostatic master with improved environmental latitude and dot shape comprising(1) an electrically conductive substrate, and coated thereon(2) a layer of photohardenable composition having a speed that requires an exposure energy in the range of 3 to 90 mjoules/sq. cm. consisting essentially of(a) at least two incompatible organic polymeric binders,(b) at least one monomeric compound having at least ethylenically unsaturated group, and(c) a photoinitiator or photoinitiator system that activates polymerization of the ethylenically unsaturated monomer upon exposure to actinic radiation,(d) a chain transfer agent, and(e) at least one polymerization inhibitor in an amount of at least 0.1% by weight based on the total weight of photohardenable composition.A xeroprinting process is described using the master. The master is used in graphic arts, color proofing which duplicates images produced by printing, preparation of printed circuit boards, resists, soldermasks, etc.
Type:
Grant
Filed:
January 12, 1990
Date of Patent:
August 27, 1991
Assignee:
E. I. du Pont de Nemours and Company
Inventors:
Graciela B. Blanchet-Fincher, Catherine Teh-Lin Chang
Abstract: The present invention relates to multistep syntheses of hexafluoropropylene from propane, propylene or partially halogenated acyclic three-carbon hydrocarbons. In all these syntheses the first step is a vapor-phase chlorofluorination of the starting material to the unsaturated chlorofluorocarbon CF.sub.3 CClCCl.sub.2.
Type:
Grant
Filed:
December 19, 1989
Date of Patent:
August 27, 1991
Assignee:
E. I. Du Pont de Nemours and Company
Inventors:
James L. Webster, Elrey L. McCann, Douglas W. Bruhnke, Jan J. Lerou, Leo E. Manzer, William H. Manogue, Paul R. Resnick, Swiatoslaw Trofimenko
Abstract: Substituted pyrroles, pyrazoles and triazoles such as ##STR1## and their pharmaceutically suitable salts are useful as antihypertensive agents and for treatment of congestive heart failure.
Type:
Grant
Filed:
March 26, 1990
Date of Patent:
August 27, 1991
Assignee:
E. I. Du Pont de Nemours and Company
Inventors:
Carini, David J., John J. V. Duncia, Gregory J. Wells
Abstract: This invention concerns compounds that are pyridine analogues of saccharin and that are synthetic sweeteners, compositions containing them, and their methods of use as sweetening agents.
Abstract: Novel 1,1,2-trifluorodienes, which have a minimum of seven carbon atoms and may contain in their molecule a phenylene or a methylphenylene moiety, are useful monomers, that can be polymerized in the presence of either free radical or coordination catalysts and can undergo selective reactions such, as for example, epoxidation of the vinyl (nonfluorinated) double bond. The resulting perfluorovinyl epoxy compounds also are useful monomers, which can undergo polymerization to useful materials.
Type:
Grant
Filed:
May 30, 1990
Date of Patent:
August 27, 1991
Assignee:
E. I. du Pont de Nemours and Company
Inventors:
Ming-Hong Hung, Aaron C. Su, Wei-Yuan Huang, Yuanfa Zhang
Abstract: An electro-optic waveguide structure having a single mode channeled waveguide pattern of the Mach-Zehnder configuration is formed in a substrate of potassium titanyl phosphate.
Type:
Grant
Filed:
September 4, 1990
Date of Patent:
August 27, 1991
Assignee:
E. I. du Pont de Nemours and Company
Inventors:
Michael P. Chouinard, Edward P. Gargiulo, James L. Hohman, Jr., Daniel B. Laubacher, Jiunn-You Liou, Moshe Oren, O. Robert Averitt, Patrick H. Wyant, Victoria Guerra-Brady
Abstract: An improved cantilevered lay-on drive roll assembly is provided for high speed winding of threadlines on separable yarn packages which are supported on a common cantilevered chuck. The assembly has a deflectable coupling which connects the drive shaft to the roll shell and spaced bearings for rotating the shell on a cantilevered support.
Type:
Grant
Filed:
April 27, 1990
Date of Patent:
August 27, 1991
Assignee:
E. I. Du Pont de Nemours and Company
Inventors:
Richard J. Angelucci, Thomas W. Manning, Jr., James F. McKinney, William D. Walker
Abstract: This invention relates to a process for alkylation at carbon and phosphorus sites in an aqueous medium using precious metal catalysts containing sulfonated triarylphosphines (STP) of the generic formula P(C.sub.6 H.sub.4 SO.sub.3 --)X(C.sub.6 H.sub.5)Y (X+Y=3).
Type:
Grant
Filed:
March 27, 1989
Date of Patent:
August 27, 1991
Assignee:
E. I. Du Pont de Nemours and Company
Inventors:
Albert L. Casalnuovo, William A. Nugent, Jr.
Abstract: Stable formed-in-place saccharinic gum membranes on a porous support, the membranes being modified by contact with at least an equivalent of multivalent cations to anionic groups in the gum.
Abstract: A pellicle packaging and handling system include a pellicle having a transparent pellicle film extending across a peripheral pellicle frame. A pellicle holder releasably grips the pellicle frame to form a holder/pellicle assembly, the pellicle holder being graspable to handle the holder/pellicle assembly and release the pellicle from the holder. The selectively openable enclosure houses the holder/pellicle assembly with the holder/pellicle assembly releasably retained in a fixed position within the enclosure.
Abstract: A process in which a stitchbonded fabric is stretched and then allowed to recover from the stretch decreases the stiffness of the fabric while greatly increasing its thickness and bulk.
Abstract: A cover for an open-bodied truck is movable between retracted and extended positions. A pair of guides are mounted on the side walls of the open body, and a cover assembly includes a plurality of rectangular panels linked to one another and extending across the open body. End portions of the panels are slidably mounted in the guides. A drive mechanism is provided for translating the cover assembly between the retracted and extended positions, and an enclosure is mounted at the forward end of the open body for receiving and storing the cover assembly in its retracted position. The tailgate of the open body is maintained in a closed and locked condition when the cover assembly is in its fully extended position.
Abstract: A contact element having a cutting section for insulation displacement connection of an insulated electrical conductor. The contact element being folded from a flat sheet of electrical conducting material, having a generally rectangular part which bears a lip projecting from one of its sides provided with a cutting slit in the end face and an angular piece having a part connected to said rectangular part and extending essentially parallel to said lip, and having a part which is at right angles thereto and faces away from said lip. The last mentioned part being provided with a further cutting slit in the end face. By appropriate folding of said flat sheet, a contact element being provided having a cutting section for side-piercing of an electrical conductor.
Type:
Grant
Filed:
May 21, 1990
Date of Patent:
August 20, 1991
Assignee:
E. I. Du Pont de Nemours and Company
Inventors:
Albertus Van Zanten, Van Woensel, Johannes M. B.
Abstract: A process for extinguishing, preventing and controlling fires using a composition containing CHF.sub.3 is disclosed. CHF.sub.3 can be used in volume percentages with air as high as 80% without adversely affecting mammalian habitation, with no effect on the ozone in the stratosphere and with little effect on the global warming process.
Type:
Grant
Filed:
October 4, 1989
Date of Patent:
August 20, 1991
Assignee:
E. I. Du Pont de Nemours and Company
Inventors:
Alfred P. Dougherty, Jr., Richard E. Fernandez, Daniel W. Moore