Abstract: A process for increasing the direct esterification reaction rate between a diacid and 1,4-butanediol and for directly esterifying greater than 95% of the acid ends of the diacid by mixing in any order the diacid, the 1,4-butanediol and a catalyst compound selected from organo-titanium, organo-tin, and organo-zirconium compounds, to form a reaction mixture wherein the ratio of diol:diacid is at least 2:1 and then reacting the reaction mixture at an average temperature ranging between 190.degree. C. to 200.degree. C. for a period of time no longer than sixty minutes. The same process may be followed substituting ethylene glycol for 1,4-butanediol, provided the catalyst compound is added neat, further provided that the average reaction temperature ranges from 190.degree. C. to 200.degree. C., and also provided that the reaction mixture be reacted for a period of time no longer than seventy minutes.
Abstract: Substituted pyrroles, pyrazoles and traizoles such as ##STR1## and their pharmaceutically suitable salts are useful as antihypertensive agents and for treatment of congestive heart failure.
Type:
Grant
Filed:
December 6, 1988
Date of Patent:
May 14, 1991
Assignee:
E. I. Du Pont de Nemours and Company
Inventors:
David J. Carini, John J. V. Duncia, Gregory J. Wells
Abstract: An apparatus for on-line determination and control of the Flow Behavior Index of a molten polymer stream are disclosed along with methods for using the Index as a means for monitoring and controlling polymer quality. In particular, the Index may be used to monitor and control on-line the levels of branching in the polymer and the polymer's molecular weight distribution.
Abstract: Permeability of structures consisting essentially of dispersions of barrier resins in permeable structural resins can be predicted by the application of near infrared spectroscopy, within the wavelength range of 600-2500 nm, especially 1100-2500 nm. The method requires establishing a correlation between base permeabilities of samples of a Training set and their near infrared spectra, developing from that correlation a predictive equation, verifying the accuracy of the predictive equation on samples of a Validation set, and applying the predictive equation to the determination of the permeabilities of unknown samples.
Abstract: The invention provides for deciding whether a recording dot is to be printed for the reproduction of scan dots. The scan dots being considered are complied in an input switching network into groups, for which an arithmetic processor determines the tonal value sum. The arithmetic processor emits a signal, if the tonal value sum exceeds a certain figure. The recording dot to be printed is determined by the presence of the signal in an output switching network. This process is performed successively for increasingly larger areas of the original, that is, for increasingly larger quantities of scan dots.
Abstract: A stator assembly for a non-static cogging brushless DC motor includes a hollow coil forming member fabricated of a nonconductive and nonmagnetic material having an array of generally radially extending teeth. Each tooth has a pair of generally radially extending sidewalls that extend substantially the entire axial length of the coil forming member. A plurality of coils is wound on the teeth of the coil forming member so that the coils are disposed in surrounding relationship with respect to the radially extending sidewalls of the teeth. The teeth on the coil forming member may extend either radially inwardly or radially outwardly thereof.
Abstract: In a solid imaging system, the beam of a relatively high-powered beam radiation source, and more particularly a laser, is modulated in accordance with its varying vector sweep speed so that substantially constant layer depth is maintained at all scanner speeds in a strip of photohardenable composition as it hardens and solidifies in response to the source's irradiation.
Abstract: A nucleic acid fragment encoding a herbicide-resistant plant acetolactate synthase protein is disclosed. This nucleic acid fragment contains at least one nucleotide mutation resulting in one amino acid change in one of seven substantially conserved regions of acetolactate synthase amino acid homology. This mutation results in the production of an acetolactate synthase protein which is resistant to sulfonylurea herbicide compounds compared to the wild-type protein. Transformation of herbicide sensitive plants or plant cells with the fragment results in resistance to the herbicide.
Type:
Grant
Filed:
March 4, 1988
Date of Patent:
May 7, 1991
Assignee:
E. I. Du Pont de Nemours and Company
Inventors:
John R. Bedbrook, Roy S. Chaleff, Saverio C. Falco, Barbara J. Mazur, Christopher R. Somerville, Narendra S. Yadav
Abstract: A permeable membrane apparatus having one or more hollow-fiber bundles enclosed in a single housing with end caps adapted so as to segment the bundles into a plurality of portions that can be separately used for fluid separation and its use.
Abstract: Photographic silver halide elements containing aryl hydrazides as defined for the production of images with ultrahigh contrast and a new class of aryl hydrazides with a cationic group in the aryl radical as defined. The photographic silver halide elements can be developed at relatively low pH values and have low fog and low tendency to form black spots in unexposed or slightly exposed areas.
Abstract: A process for making alternate S and Z twist plied yarn from individual singles yarns includes the steps of tensioning the singles yarns as they move in a path through the process, twisting the individual yarns in either an S or Z direction, stopping the forward movement of the yarn, then bonding the ply-twisted yarns at a node while applying twist, stopping the twisting operation, then repeating the procedure while twisting in the opposite direction.
Type:
Grant
Filed:
March 13, 1989
Date of Patent:
May 7, 1991
Assignee:
E. I. Du Pont de Nemours and Company
Inventors:
Donald E. Hallam, Peter Popper, Harold F. Staunton, Paul W. Yngve
Abstract: Film speed of holographic photopolymer film containing polyvinyl acetate binder and an ethylenically unsaturated monomer is improved by including acrylic anhydride in the film.
Abstract: Polymer blend composition having improved processibility and comprising:(a) a major portion of a difficultly melt-processible polymer, and(b) a minor portion of:(1) at least an effective amount, to improve processibility, of a fluorocarbon copolymer which at the melt-processing temperature of (a) is either in a melted form if crystalline, or is above its glass transition temperature if amorphous, and(2) at least an effective amount, to improve processibility, of at least one tetrafluoroethylene homopolymer or copolymer of tetrafluoroethylene and at least one monomer copolymerizable therewith, wherein the mole ratio of fluorine to hydrogen is at least 1:1, and which is solid at the melt-processing temperature of (a);masterbatches comprised of the processing aid; and processes utilizing the processing aid.
Type:
Grant
Filed:
August 29, 1990
Date of Patent:
May 7, 1991
Assignee:
E. I. Du Pont de Nemours and Company
Inventors:
George R. Chapman, Jr., Donnan E. Priester, Charles W. Stewart
Abstract: The invention is directed to a process for increasing the filling capacity of tobacco wherein tobacco is contacted with a mixture of an inert, normally gaseous expansion agent and about 15-35 weight percent of carbon dioxide at a pressure above the critical pressure of the mixture and a temperature above the critical temperature of the mixture, followed by rapid release of pressure to provide expanded tobacco without a subsequent heating step. Advantageously, the expansion agent is propane.
Abstract: Trash bags and other products from LLDPE are made animal repellent by incorporation of terpene in the LLDPE in the melt process for fabricating such products from the polymer.
Abstract: The image dot gain that normally occurs in a printing press is controllably simulated as a separate step in the process of producing accurate color proofs. The simulation is attained by placing a diffuser plate between a high-intensity light source and a color-separated image master along with its corresponding image receptor. By varying the position of the diffuser plate the percentage of image dot gain is accurately controlled as an independent variable without the need to alter the exposure time.
Abstract: A bonded composite sheet comprising a layer of flash-spun polyethylene plexifilamentary film-fibril strand sheet in face-to-face contact with a layer of polyethylene synthetic pulp is highly suited for detailed printing thereon.
Abstract: A capacitive sensor is described having an element which traverses the outside of a container of liquid to ascertain the vertical locations of liquid interfaces in the container. The sensor uses an oscillator whose amplitude or phase is a function of the capacitance of the element.
Abstract: Amphoteric polymers prepared by polymerization of (a) acrylic acid, (b) N,N-dimethyl- or N,N-diethylaminoethyl methacrylate and, optionally, (c) esters of methacrylic or acrylic acid prepared by (i) emulsion polymerization of (b), (c) and the methyl ester of (a), followed by basic hydrolysis, or (ii) polymerization of (a), (b) and (c) in the presence of a strong acid, and photographic emulsions comprised of said polymers in which the molar ratio of (a) to (b) is at least 2 to 1 and a silver halide.
Abstract: An improved mechanism for connecting a ground-engaging blade to the frame of a vehicle is disclosed which allows the blade to tilt, pitch or angle relative to the frame. The disclosed arrangement includes a pair of hydraulic cylinders which control the tilting or pitching of the blade and a single hydraulic cylinder which controls the angling of the blade. The cylinders are all pivotally connected to an intermediate member which is pinned to the blade and guided through an arc on the frame by a guide bar formed on the frame. A single hydraulic circuit is disclosed which powers the pair of hydraulic cylinders to pitch or tilt the blade relative to the frame. The resulting arrangement is both simplified and relatively stable when compared to prior art structures.