摘要:
A borated aqueous solution from a nuclear reactor coolant system dilute chemical-decontamination process or from an equipment washing process which has been contaminated with radioactive metals or heavy metals including cobalt, nickel, chromium, iron, manganese, lead or mercury and with a chelating agent, detergent or soap is treated with an oxidizing agent to oxidize the chelating agent, detergent or soap and to precipitate the contaminant metals. The contaminant metals are then separated from the solution by centrifugal filtration, micromembrane belt filtration or magnetic separation. Advantageously, a very small volume of precipitate may then be buried and the decontaminated solution may be recycled or further treated and released for other uses.
摘要:
Disclosed is a method of making a laminate by electrophoretically coating a flat mat made from a material selected from graphite, carbon, and mixtures thereof with an electrophoretable polymer in a non-aqueous system. The polymer is cured and the mat is impregnated with a thermosetable impregnating resin. The impregnating resin is B-staged to form a prepreg and several prepregs are stacked and cured under heat and pressure to form the laminate. Also disclosed is a laminate made by this method.
摘要:
Disclosed is an emulsion having a discontinuous phase which comprises at least two compounds of different structural formula selected from the group consisting of solvent-soluble polymers, oligomers, and monomers dissolved in an organic solvent, and a discontinuous phase which comprises an organic non-solvent for the compounds. A method of coating a conductor with a polymeric alloy is also disclosed. The conductor is immersed in the emulsion and a direct current is applied between the conductor and the emulsion sufficient to cause the discontinuous phase of the emulsion to migrate to the conductor and deposit on it. The conductor is removed from the emulsion and is dried and the deposit is cured.
摘要:
Disclosed is a method of making an adhesive comprising forming a first composition of a polyesterether glycol having the general formula ##STR1## where R.sub.1 and R.sub.2 are each independently selected from alkylidene from C.sub.1 to C.sub.10, and n is about 1 to about 5 about 0.01 to about 1% by weight (based on the weight of the polyesterether glycol) of a catalyst, and sufficient solvent for said adhesive to have at least 50% solids, forming a second composition of about 0.85 to about 0.95 mole % of a diisocyanate and about 0.15 to about 0.05 mole % of a polyisocyanate, and mixing the first and second compositions together. The adhesive is applied to a first substrate, the solvent is evaporated, and a second substrate is pressed against the adhesive on the first substrate to form a flexible laminate.
摘要:
A resin impregnated, B-staged sheet material free of crystal formations, useful for metal clad and unclad laminate production, is made by impregnating a sheet containing a resin comprising epoxy resin and an amount of curing agent effective to cure the epoxy resin to the C-stage, where the curing agent consists essentially of the reaction product of dicyandiamide and an aminophylic reagent selected from the group consisting of aldehydes, alkyl monoglycidyl ethers having the formula: ##STR1## where R=an alkyl group having from 1 to 4 carbon atoms, styrene oxide, ethylene oxide, propylene oxide, acetic anhydride, benzoyl chloride, acetyl chloride, and mixtures thereof, and then heating the impregnated sheet until the resin is in the B-stage.
摘要:
An adhesive composition free of free-radical catalysts is disclosed comprising hydroxy terminated 1,2-polybutadiene, a diisocyanate, and either styrene, vinyl toluene, or a mixture thereof. The adhesive composition is A-staged whence a free-radical catalyst is added. A material such as a film or fibrous reinforcement is coated with the composition and the composition is B-staged. The coated material can be cured during lamination with copper in a heated nip roll.
摘要:
Disclosed is a method of making a non-aqueous emulsion from which a polymer can be electrodeposited. A mixture is prepared of about 50 to about 150 parts by weight of a non-aqueous organic, non-electrolizable, non-solvent for the polymer with about 0.8 to about 1.2 parts by weight of a nitrogen-containing base which can be a tertiary amine, an imidazole, or mixture of a tertiary amine and an imidazole. To the mixture is added a solution of 1 part by weight of the polymer which can be a polyamic acid, a polyamide imide, a polyimide, a polyparabanic acid, a polysulfone, or a mixture of these polymers. The polymer is in a non-aqueous, organic, non-electrolizable aprotic solvent such as N-methyl-2-pyrrolidone.
摘要:
Aqueous emulsions of epoxy resins, which can be used to treat glass cloth used in the preparation of printed circuit board laminates, are produced by combining an epoxy resin and a flame retardant phenol, such as tetrabromobisphenol A, with a selected nonionic surface active agent, such as an alkylaryl polyether alcohol, monomethylol dicyandiamide curing agent and, if needed, a catalyst.
摘要:
Amide-imide polymers formable in deep section and prepared by the condensation reaction of at least one of a diacid halide or a polyanhydride or equivalent, and a diamine containing at least one imide linkage. Soluble amide-imide polymers having the general formula: ##STR1## where n is an integer greater than 10 and preferably greater than 20. A novel amine having the general structural formula: ##STR2## wherein: A is selected from the group consisting of --R'-- and ##STR3## R is a trivalent organic radical in which the two valences included in the imide ring are attached to adjacent carbon atoms and the third valence is attached to a different carbon atom,R' is a divalent organic radical,R" is a tetravalent organic radical in which the bonds are attached to two pairs of adjacent carbon atoms, so that five or six membered imide rings are formed,a, b, c, and d are integers from 0 to 6, the sum of a, b, c, and d is an integer from 1 to 6, at least one R or R" group is included in the molecule, and the bracketed groups are in any order.Although one or more of the R, R', or R" radicals may contain one or more additional amino groups or other compatible linkages, preferably said amine contains only said terminal amino groups.
摘要:
A composition is disclosed of a dianhydride and a tetracarboxylic acid in the proportions of about 50 to about 70 mole % dianhydride to about 30 to about 50 mole % tetracarboxylic acid, a stoichiometric amount of an aromatic diisocyanate, and a solvent for the dianhydride, the tetracarboxylic acid, and the diisocyanate. A polyimide precursor is prepared by heating the composition at about 30.degree. to 70.degree. C until the evolution of carbon dioxide substantially ceases, and then at about 30.degree. to about 100.degree. C until its viscosity is about Q to about Z6 on the Gardner-Holdt viscosity scale at 18% solids. The polyimide precursor can be spread on a substrate and cured to produce a polyimide film or coated on a wire and cured to produce a polyimide wire enamel.