Abstract: Disclosed is an improved process for casting the impression of a tire tread by preparing a negative mold of the tire tread and making a positive cast from the negative mold. The improvement consists of pouring a liquid photopolymerizable composition into the negative mold of the tire tread, applying a vacuum, exposing the composition to ultraviolet radiation to cross-link the polymer, removing the positive cast from the negative mold, and exposing the cast to additional ultraviolet radiation in the absence of oxygen to harden the surface of the cast.
Type:
Grant
Filed:
August 7, 1989
Date of Patent:
November 13, 1990
Assignee:
Hercules Incorporated
Inventors:
Joseph DeGiovanni, Richard B. Schroeder
Abstract: Disclosed are aqueous polyacrylate dispersions having improved rheological and stability characteristics prepared by the emulsion polymerization of acrylic esters, methacrylic esters and mixtures thereof in the absence of a protective colloid, wherein the improvement comprises conducting the polymerization in the presence of, by weight of the total monomer content, from about 0.1 to 2% of at least one substantially completely water-soluble monomer having conjugated unsaturation. The resultant aqueous polyacrylate dispersions are useful in the manufacture of latex paints, binders for nonwoven materials, water-based inks, paper coatings and water-borne adhesives, such as pressure-sensitive adhesives.
Abstract: A novel polyfunctional maleimide-based thermosettable resin composition comprising: (a) at least one polyfunctional maleimide compound selected from the group consisting of bismaleimide and polymaleimide, and (b) at least one ether derivative of an alkenylphenol.
Type:
Grant
Filed:
August 17, 1987
Date of Patent:
October 9, 1990
Assignee:
Hercules Incorporated
Inventors:
Sung G. Chu, Harold Jabloner, Tuyen T. Nguyen
Abstract: A liquid stream (13) and a detector (12) and a computer (11) which operate to observe properties in the composition of the fluid stream and compare detected data from observed samples with standards and in accordance with parameters established by calibration calculate the characteristics of the observed samples.An integral but segmented liquid stream (13) flows through the analysis system (10) to provide liquid segments of observed sample and reagent. A detector (12) scans data from the samples at the interface between these segments and information relating to the composition at the interface is analyzed by a mathematical model that permits comparison of the detected data from successively observed samples with standards and thus determines the characteristics of the samples. The segmented integral liquid stream (13) is fashioned by step pulsing of discrete segments of reagents and samples and transporting the discrete segments to a detector (12).
Type:
Grant
Filed:
September 19, 1989
Date of Patent:
September 18, 1990
Assignee:
Hercules Incorporated
Inventors:
David L. Davidson, George B. Parrent, Jr., Roland W. Gubisch, Harold Hauer
Abstract: An active voltage divider circuit is applied to the loop filter of a phase-lock loop, thereby providing a variable gain factor, wherein the gain with large phase error is substantially greater than the gain with small phase error. This results in improved acquisition time for large frequency offsets, while providing in the phase-lock state the same performance as a conventional loop having the same natural loop frequency and damping factor. By sampling the applied radio frequency signal with an amplitude detector and applying the sampled output and the output of a phase sensitive detector to an analog divider, amplitude variations of the input signal are cancelled, thereby making the loop filter essentially independent of the amplitude of the input signal. In a further embodiment the input signal is coupled to a quadrature detector wherefrom I and Q output signals are coupled to a divider which provides error signals to the loop filter that are independent of the input signal amplitude.
Type:
Grant
Filed:
January 9, 1989
Date of Patent:
August 28, 1990
Assignee:
Hercules Defense Electronics Systems, Inc.
Abstract: Described are novel thermosetting maleimide compositions suitable for making cured resins, prepregs and tough thermoset composites. The thermosetting compositions comprise a multifunctional maleimide and terminally unsaturated polyamide, polyimide, or polyamideimide oligomer which is soluble in the composition. The cured resins have a fracture toughness, K.sub.ic, of at least 1.0 MPam.sup.1/2 and a glass transition temperature of at least 200.degree. C.
Type:
Grant
Filed:
July 15, 1987
Date of Patent:
August 7, 1990
Assignee:
Hercules Incorporated
Inventors:
Sung G. Chu, Harold Jabloner, Tuyen T. Nguyen
Abstract: Disclosed is a process for promoting the rapid curing of a two component polyurethane lacquer that has been applied to a substrate. A cure coat composition consisting of a hydroxy functional polymer such as nitrocellulose, a solvent for the polymer, and a urethane catalyst such as an organic tin compound, is applied over the polyurethane lacquer while it is in a wet or semi-dry state.
Abstract: A rosin emulsion sizing agent comprising a fortified rosin, an at least partially quarternized product copolymer principal consisting of a (meth)acrylic acid alkylaminoalkyl ester or amide monomer and water exhibits excellent sizing effect in a papermaking system of higher pH, higher water hardness and higher temperature, in which conventional anionic rosin emulsion sizing agents cannot effectively function.
Abstract: A method for placing hydrophobic polyolefin fiber in condition for cutting, carding and production of nonwoven material without substantial sacrifice in desired hydrophobic properties in the corresponding nonwoven, by utilization of a sequential treatment of the fiber with a neutralized phosphoric acid ester and a polysiloxane of defined classes.
Abstract: A compound of the general formula, ##STR1## wherein R.sub.1 and R.sub.2 independently are --H, --CH.sub.3, or --CH.sub.2 CH.sub.3 ; and R.sub.3 is alkyl of from 1 to 10 carbons or aryl of from 6 to 10 carbons.
Abstract: A graphics display apparatus using a character generation architecture is disclosed. A font memory is disclosed which can be addressed to provide a different character for each character position on a display screen. In this manner graphics images can be manipulated at character generation speeds. Further, memory can be more efficiently used and font registers and additional pages of memory are not required to accommodate an expanded font list. In accordance with the present invention, attributes are generated in hardware so that the base text can remain unchanged even though the attributes of the text are changed. A unique echo circuit is provided to generate a bold faced attribute, including an anti-smear function. In the preferred embodiment of the present invention, a single memory is used to store textual and font information, thus reducing the size and costs of the character generation architecture.
Abstract: A method and apparatus are disclosed for binding a nonwoven material by means of a binding agent requiring heat for activation, particularly for binding cellulosic fibers with a thermoplastic material. The material is irradiated with an infrared radiation source, and surface burning of the irradiated material is prevented by passing a weak flow of air through the material. Inclined walls guide the air flow through the material in an inclined path directed from the edge of the infrared radiation source and towards the center thereof. Each infrared radiation source is surrounded by two side walls so that a space is formed between each side wall and the radiation source for the passage of the inlet air. The cross-sectional areas of these spaces are together approximately equal to the cross-sectional area of a suction channel positioned opposite the spaces. The air flow is controlled by means of two speed-regulated fans, one at the inlet and one at the outlet of the apparatus.
Abstract: Disclosed is a method of delaying the metathesis polymerization of strained ring cycloolefins by addition of certain phosphorus-containing compounds including various aryl phosphates, aliphatic phosphates, aliphatic phosphites, aryl phosphites, aryl phosphines and alkyl phosphines.
Abstract: A propellant composition and method for limiting the corrosive properties of by-products from initiated crash bag propellant compositions comprising a 1(a) or 2(a) group metal azide salt, an oxidizer in the form of an oxide of a non-toxic transition metal element, and an effective amount of a modifier component of the formulaMe.sub.x (An).sub.owhereinMe is a metal cation selected from iron, copper, cobalt, nickel, and molybdenum;An is an anion group which is chemically compatible with and capable of reacting with the metal of the azide salt to form nitrogen gas and non-toxic by-products less corrosive than the corresponding hydroxide of the azide metal would be; andx and o are individually defined as a positive number not exceeding about 4, the sum of which does not exceed about 5.
Abstract: Polysilazane addition polymers are prepared by (1) reacting ammonia with one or more halogenated organic silicon compounds to produce a cyclic silazane ammonolysis product and (2) reacting the ammonolysis product with from 0.1% to 30% by weight of an isocyanate, isothiocyanate, ketene, thioketene, carbodiimide, or carbon disulfide. Polysilazane addition polymers containing alkenyl or alkynyl groups can be cured by supplying energy to generate free radicals. The cured or uncured polymers can be pyrolyzed to produce silicon nitride-containing ceramic materials.
Abstract: A method of treating polyester fabric to enhance the physical properties thereof. The fabric is first exposed to a solution comprising a wetting agent, a nonionic fluorocarbon long chain polymer, a nonionic, cationic or anionic nonsilicone based softener, a gum and a carrier comprising water and/or an organic solvent. The fabric is then exposed to heat and tension to evaporate the carrier from the solution, polymerize the nonionic fluorocarbon long chain polymer, cross-link the polyester, the softener, the gum and the nonionic fluorocarbon long chain polymer and reorient the polyester to a more crystalized structure.
Abstract: Increased resistance of the cut edges of liquid packaging board to penetration by hot hydrogen peroxide is obtained by adding an aqueous emulsion of ketene dimer, cationic rosin size and insolubilizing agent either separately or in preblended form to the aqueous pulp slurry at a neutral to alkaline pH.
Abstract: A soft, flexible, microporous film is provided having high tensile strength and good air and water vapor transmission rates therethrough while being substantially impenetrable to liquid water. This film is prepared by stretching a casting of a composition of a polyolefin and high levels of CaCO.sub.3 or glass beads and calcium stearate in two directions from 1.5-7 times in each direction to produce a film having a Gurley porosity of from 0.1 to 85 seconds. This film is especially useful for disposable items such as feminine panty liners, diapers, bed sheets, and hospital gowns. When glass beads are substituted for the CaCO.sub.3, the film is useful for battery separators.