Abstract: A method of accelerating decomposition of non-living plant material from a ground surface. The method employs the application of a saprotroph containing suspension to non-living plant material such as leaves or the stubble of a cultivated crop. The suspension is formulated with a pH and nutrient level whereby the physiologic activity of the saprotroph is optimized. The deposited saprotroph containing suspension accelerates the natural decomposition process without decomposing living plant material. A resulting humus is thereby formed which brings nutrients back into the ground surface.

Abstract: A radiation curable coating composition comprising acrylate oligomers and monomers, vinyl ether monomers, and a free radical photoinitiator. The vinyl ether monomers replace N-vinyl-pyrrolidone or other undesirable reactive diluents while retaining or modifying the properties of coatings using such diluents.

Abstract: A free-radical radiation curable composition comprising:a) at least one compound containing one to six vinyl ether groups; andb) at least one compound containing a urethane backbone with one to six maleate and/or fumarate end groups,wherein the ratio of vinyl ether groups to maleate and/or fumarate groups is in the range of about 1 to about 1:5.

Abstract: A free-radical radiation curable composition comprising:a) at least one compound containing from one to about six vinyl ether groups; andb) at least one compound containing a saturated backbone and at least one maleate or fumarate end group per molecule,wherein the ratio of vinyl ether groups to maleate or fumarate groups in the composition is in the range of about 5:1 to about 1:5.

Abstract: A free-radical radiation curable composition comprising:a) at least one compound containing from one to about six vinyl ether groups; andb) at least one product obtainable by the reaction of a half-ester of maleic and/or fumaric acid with an epoxy functionalized compound,wherein the ratio of vinyl ether groups to maleate and/or fumarate groups is in the range of about 5:1 to about 1:5.

Abstract: The present invention contemplates a stereolithographic apparatus and method having a liquid organic phase and a fluid phase separated by a membrane that inhibits contact between the phases.

Abstract: A method of coating a concrete floor is disclosed in which the concrete surface is coated with a homogeneous liquid coating composition containing maleate or fumarate unsaturation in combination with vinyl ether unsaturation and a ketonic photoinitiator, the wet coating is allowed to seep into the concrete surface and to flow out on the concrete surface to form a smooth coating, and this coating is cured by exposing it at light having a wavelength in the range of from about 200 to about 600 nanometers.

Abstract: A cationically curable polyurethane composition comprises the reaction product of an organic polyisocyanate with a transvinylation polyhydric alcohol mixture containing hydroxy groups. The polyisocyanate consumes substantially all of the available hydroxy groups in the transvinylation polyhydric alcohol mixture. These compositions are particularly useful in stereolithography. A method of transvinylation utilizing ultrasonic energy is also disclosed.

Abstract: A method of curing a three-dimensional specimen of preformed cross-linked polymeric material containing polymerizable ethylenically-unsaturated material is provided in which the specimen is immersed in water having dissolved therein an amount of a water-soluble organic free-radical polymerization catalyst effective to transfer a polymerization-initiating amount of the catalyst into the preformed cross-linked polymeric material. This specimen containing the water-soluble organic free-radical polymerization catalyst is heated to a temperature causing polymerization, and is maintained at that temperature while the cure is completed. The aqueous bath preferably contains a catalyst mixture which includes a catalyst of oxidizing character in admixture with a reducing agent, such as an amine, and is maintained at a polymerization temperature of from 60.degree. C. to 100.degree. C. so that immersion of the specimen in a single bath completes the cure.

Abstract: An improved stereolithographic process is provided in which the formation of a thin walled three-dimensional object in a reservoir of liquid ultraviolet-curable ethylenically unsaturated material using a support is positioned immediately beneath the upper surface of the liquid reservoir with that upper surface being exposed to ultraviolet light in a pattern to solidify the liquid at and near the upper surface in a series of cross-sections of the desired three-dimensional object, one atop the other. In this way there is formed a series of superposed layers which adhere to one another to build the desired three-dimensional object within the liquid reservoir. The improvement comprises, stopping the exposure at any portion of the surface in the formation of said layers and then repeating the exposure at least once again in the production of each surface layer so that the strength and solvent resistance of the formed object are increased and its distortion is minimized.

Abstract: A stereolithographic method which employs an ultraviolet-curable liquid composition adapted to cure rapidly to a lightly cross-linked solvent-swellable three-dimensional complexly-shaped polymeric thin-walled element constituted by heat-softenable solid polymer upon exposure to ultraviolet dosage in the range of about 0.1 to about 10 Joules per square centimeter and which possesses reduced distortion comprises, from 20 to 80 weight percent, of a resinous polyacrylate or polymethacrylate dissolved in a combination of 10 to 45 weight percent of a liquid polyacrylate or polymethacrylate, which is preferably trifunctional, and 10 to 45 weight percent of liquid N-vinyl monomer, preferably N-vinyl pyrrolidone. Thus, the weight ratio of polyacrylate: polymethacrylate: N-vinyl monomer is about 1:2:2 to about 8:1:1. One of the foregoing polyacrylates or polymethacrylates is a polyacrylate and the other is a polymethacrylate so that good cure speed is accompanied by good distortion resistance.

Abstract: A method of investment casting utilizes a pattern produced by stereolithography in which a three-dimensional specimen is provided by light cure of ethylenically unsaturated liquid material. The stereolithography composition is constituted by the ethylenically unsaturated liquid material in admixture with an inert low thermoplastic material which weakens the pattern when heated within the mold used in the investment casting process to prevent the thermal expansion of the pattern from cracking the mold.

Abstract: An ultraviolet curing liquid coating composition which, when cured with ultraviolet light in the presence of an appropriate photoinitiator, provides a coating adapted for the coating of optical glass fiber. This coating composition comprises as the essential component, an acrylate-terminated polyurethane oligomer based on a polyfunctional core which is at least trifunctional and which supports one branch for each functionality in the core. Each of the branches leads to an acrylate-functional terminal group, with there being from about 150 to about 2500 units of molecular weight in each branch between the trifunctional core and the acrylate-functional terminal group. Depending primarily upon the molecular weight of the branches, one can provide coating compositions for buffer coat, single coat or topcoat use.

Abstract: An ultraviolet curing liquid coating composition is disclosed which, when cured with ultraviolet light in the presence of an appropriate photoinitiator, provides buffer coatings for optical glass fiber having adequate strength at room or expected elevated temperature and stability at such elevated temperature, a high index of refraction above 1.48, and a low tensile modulus which remains low to resist microbending difficulties down to around -60.degree. C. This coating composition consists essentially of a linear polyacrylate-terminated polyurethane or polyurea oligomer having a room temperature tensile modulus of at least 100 psi., and a tensile modulus at -60.degree. C. which is less than 175,000 psi., when capped with 2-hydroxyethyl acrylate and cured with ultraviolet light, in admixture with a liquid acrylate-functional material which does not increase the low temperature hardness and which provides the liquidity needed for coating application.

Abstract: A radiation-curable diethylenically unsaturated polyurethane resin is disclosed which cures to provide cured coatings possessing reasonable physical integrity at room temperature, a tensile modulus of less than about 10000 psi at -40.degree. C., preferably less than 5000 psi at -60.degree. C., and a high index of refraction, above 1.48. This polyurethane resin is constituted by an essentially saturated, halogenated, dihydroxy-terminated linear liquid polybutadiene polymer, in which the halogen is preferably chlorine, reacted with an organic diisocyanate and a monoethylenically unsaturated monomer carrying a single hydroxy group to form a diethylenic diurethane having a halogen-containing essentially saturated polybutadiene backbone.

Abstract: There is disclosed linear polymers and copolymers of polymerized monoethylenically unsaturated monomers having a weight average molecular weight from about 1,500 to about 15,000, with most of the polymer ends being terminated with hydroxyl groups, one at each end of the polymer molecule. These polymers have an average of from about 1.6 to 5 hydroxyl groups per polymer molecule. Thermosetting coating compositions containing these polymers are also disclosed. The monomers which are polymerized may include a small proportion of hydroxy-functional monomers, but desirably consist of monoethylenically unsaturated monomers lacking hydroxyl functionality.

Abstract: A method of producing essentially monomeric etherified formaldehyde condensates with a bisphenol having a plurality of formaldehyde-reactive sites is disclosed in which the bisphenol is reacted with at least about 2 moles of formaldehyde per mole of bisphenol in solution in etherifying alcohol in the presence of an insoluble strong acid cation exchange resin. The reaction is carried out at a reaction temperature of from about 30.degree. C. to about 100.degree. C. to simultaneously provide the desired methylolation and etherification without introducing soluble ionic contaminants.

Abstract: An air drying latex coating composition, curable under ambient conditions, is described having copolymer particles consisting essentially of copolymerized monoethylenically unsaturated monomers dispersed in an aqueous emulsion. The copolymer particles have 0.5-30% by weight of ethylenically unsaturated monomers bonded thereto through reacted C.sub.1 -C.sub.6 N-alkylol functionalities. Curing agents or curing catalysts are also present to cure the deposited composition. The coating compositions are provided by forming an aqueous dispersion of the copolymer particles, bonding an ethylenically unsaturated monomer thereto through a C.sub.1 -C.sub.6 N-alkylol functionality, and admixing therein a curing catalyst or curing agent.

Abstract: A sand core and mold composition for use in casting metals comprising foundry sand, clay, water and from about 0.0025% to about 1% by weight of a water-soluble graft copolymer of acrylic acid and a minor amount of a water-soluble polyhydroxy polymeric compound, including water-soluble salts thereof.