摘要:
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.
摘要:
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. The ultraviolet exposure of each surface layer is preferably carried out as a series of rapid repeated scans of a computer-directed focused laser.
摘要:
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. In the method, a reservoir of the liquid composition is established and its exposed surface is irradiated to solidify the surface and build up a thin-walled element which is removed from the reservoir, drained of liquid adhering thereto and cured.
摘要:
The present invention relates to a polymeric hair conditioning composition of vinyl pyrrolidone monomer, an ammonium derivative monomer and a substantially major amount, based on said monomers, of vinyl caprolactam said polymeric composition optionally containing a minor amount of stearyl methacrylate. Suitable ammonium derivative monomers include dimethylamino propyl methacrylamide, dimethyl diallyl ammonium chloride and a dialkylamino alkyl methacrylate, such as for example dimethylamino ethyl methacrylate.
摘要:
An ultraviolet light-curable liquid coating composition for molded plastic objects is disclosed. The composition is a liquid mixture of a polyurethane oligomer polyacrylate and an hydroxy-functional polyacrylate ester. The polyacrylate ester is present in an amount of from more than 50% up to 70% of total polyacrylate, and the composition is in solution in alcoholic solvent providing a solids content of from 65% to 90%. A photoinitiator is included to render the composition curable upon exposure to ultraviolet light.
摘要:
A low temperature curing solution coating composition is disclosed for the protection of solvent-sensitive thermoplastic moldings. In these compositions, a solvent medium consisting essentially of alcoholic solvents has dissolved therein a self-curing solution copolymer of monoethylenically unsaturated monomers containing an ether of an N-methylol functional monomer, especially isobutoxymethyl acrylamide. This solution is catalyzed with from 3% to 12%, based on the weight of the copolymer, of a long chain dialkyl naphthalene disulfonic acid. The catalyzed compositions are stable and cure at 150.degree. F. to 200.degree. F. without damaging the thermoplastic moldings.
摘要:
A low temperature curing solution coating composition is disclosed for the protection of solvent-sensitive thermoplastic moldings. In these compositions, a solvent medium consisting essentially of alcoholic solvents has dissolved therein a self-curing solution copolymer of monoethylenically unsaturated monomers containing an ether of an N-methylol functional monomer, especially isobutoxymethyl acrylamide. This solution is catalyzed with from 0.5% to 2.0%, based on the weight of the copolymer, of sulfuric acid. The catalyzed compositions are stable and cure at 150.degree. F. to 200.degree. F. without damaging the thermoplastic moldings.
摘要:
Carboxy functional addition-polymerizable monoethylenically unsaturated monomers and their volatile amine salts are disclosed, along with addition copolymers useful in coatings prepared therefrom. Both monomers and polymers decompose on heating. The monomers are bisamides comprised of a monoethylenically unsaturated amide and malonic acid half amide joined through their amide functionalities by a divalent saturated aliphatic group having 1-4 carbon atoms.
摘要:
Base neutralized electrodepositable coating compositions which may be utilized in a continuous electrophoretic process without the necessity of employing membrane controls. Such coating compositions are micellar dispersions comprising a resinous vehicle which is blended or admixed with an organic liquid dispersant, said dispersant having limited solubility in water and a limited affinity for the electrodepositable vehicle, and whereby the admixture is subsequently partially neutralized with a base. Such compositions when cured provide for coatings having good salt spray resistance, mar resistance, appearance, and other desirable physical characteristics.