Abstract: Blocked isocyanate terminated prepolymers with improved handling and processing properties are prepared from isocyanate terminated prepolymers with very low free isocyanate monomer content. The blocked prepolymers have lower melting points and/or viscosities compared to similar blocked isocyanate terminated having traditional, higher amounts of free isocyanate monomer. Curing compositions comprising the blocked prepolymers are prepared and cured to form polyurethane polymers with excellent properties.

Abstract: Polycarbonate based polyurethane prepolymers having a low amount of free isocyanate monomer with excellent handling and processing properties are prepared and used in the preparation of cast polyurethane polymers with excellent performance and handling properties.

Abstract: Co-distilling a mixture of para-phenylene diisocyanate (PPDI) and solvent, collecting the mixture of solvent and PPDI as a solution, reacting this solution with a polyol to form a prepolymer, and then removing unreacted PPDI by distillation in the presence of one or more solvents provides lower color prepolymer and higher quality polyurethane resin than a similar process that omits the co-distillation of PPDI and solvent prior to reaction with the polyol.

Abstract: Thermoplastic polyurethane (TPU) made using low free isocyanate monomer (LF) prepolymer, for example a prepolymer based on p-phenylene diisocyanate (PPDI) with low free isocyanate content, possess unique performance features including exceptional tear strength, low compression set, and an exceptional overall balance of physical properties including high temperature mechanical strength.

Abstract: A polyurethane-urea is prepared by reacting a mixture of a p-phenylene diisocyanate terminated urethane prepolymer, at least one plasticizer, and alkylated 4,4?-methylenedianiline chain extender.

Abstract: A radiation-curable polyurethane is obtained from the reaction of a low free diisocyanate polyurethane prepolymer and an acrylic monomer.

Abstract: Polyurethane prepolymers with reduced amount of unreacted monomeric hexamethylene 1,6-diisocyanate (HDI) are provided. Also provided are polyurethane elastomers obtained by mixing the polyurethane prepolymers having reduced amount of unreacted monomeric HDI with amine and/or hydroxy chain extenders and durable, resilient, colorfast golf ball covers obtained therefrom. Rolls, wheels and tires obtained from the polyurethane elastomers are also provided.

Abstract: A radiation-curable polyurethane is obtained from the reaction of a low free diisocyanate polyurethane prepolymer and an acrylic monomer.

Abstract: A monomer composition characterized by being curable to form a resin suitable for optical products having a balanced refractive index and Abbe's number range and good tintability comprising a polyene monomer; and polyisocyanate, polyisothiocyanate, or an isocyanate monomer containing at least one isothiocyanate group; and a monomer having two or more active hydrogen groups such as polythiols, polyamines, and polyols. The invention also provides a special process for making the composition and for curing the composition to form a resin product.

Abstract: Polyurethane prepolymers with reduced amount of unreacted monomeric hexamethylene 1,6-diisocyanate (HDI) are provided. Also provided are polyurethane elastomers obtained by mixing the polyurethane prepolymers having reduced amount of unreacted monomeric HDI with amine and/or hydroxy chain extenders and durable, resilient, colorfast golf ball covers obtained therefrom. Rolls, wheels and tires obtained from the polyurethane elastomers are also provided.

Abstract: An ultrasonic computed tomography tree or log scanner has a plurality of ultrasonic transceivers carried on a belt (102) sized to encircle a tree (100). The belt includes an apparatus for engaging is tightly around the tree (104). The transceivers are strapped around the tree, and their mutual relative distances are known. Electronic circuitry energizes the transmitters in a known sequence. The signals received at each of the receivers are also collected and analyzed. Computed tomographic techniques analyze the time of arrival of the acoustic pulse that is first to arrive at each receiver. A signal processor generates a two-dimensional image of a slice of the tree (110) at the locus of the belt.

Abstract: A method of continuously fabricating a lens excellent in various optical characteristics and having no nonuniformity in the characteristics over a total of the lens and a lens fabricated by the method. A first step for forming thiourethane prepolymer and a second step for making thiourethane prepolymer react with at least one urethane forming monomer are carried out in an extruder or in a reactor having an extruding device at a succeeding step, extruded thermoplastic thiourethane-urethane copolymer for optical use is elongated in a sheet-like shape, a lens precursor is formed by punching out the copolymer elongated in a sheet-like shape and the lens precursor is pressed such that a predetermined curved face is provided at least on one face of the lens precursor.

Abstract: A monomer composition characterized by being curable to form a resin suitable for optical products having a balanced refractive index and Abbe's number range and good tintability comprising a polyene monomer; a polyisocyanate, polyisothiocyanate, or an isocyanate monomer containing at least one isothiocyanate group; and a monomer having two or more active hydrogen groups such as polythiols, polyamines, and polyols. The invention also provides a special process for making the composition and for curing the composition to form a resin product.

Abstract: A process for making thermoplastic thiourethane-urethane copolymers for use in making optical products preferably comprising reacting an aliphatic diisocyanate with a dithiol under polymerization conditions to form a thiourethane prepolymer which is then reacted with a diisocyanate such as methylene bis(phenyl isocyanate) and a polyol such as a diaromatic containing diol such as ethoxylated Bisphenol A or an aliphatic isocyanate reactive monomer such as tricyclodecane dimethanol or 1,4-dimethanol cyclohexane to form the copolymer product. The polymers have a combination of high refractive index and high Abbe No. The polymers also have high impact strength, high hardness and Tg's above 100.degree. C. It is preferred to make the polymer in an extruder.