摘要:
A method for forming objects includes a step of spreading base material on a limited area by nozzles or rollers, step of proceeding a first time of physical or chemical change on selected areas by heating boards, ultra violet beams or infra-red beams so as to have gel-like material, and step of selectively proceeding a second time of physical or chemical change by laser beam or adding additional material on the selected areas of the base material so that the nature of the gel-like material becomes acceptable. The gel-like material is laminated to build a three dimensional object.
摘要:
Adducts of metabrominated monophenols such as 3,5-dibromo-2,4,6-trimethylphenol and multifunctional epoxides such as cresol-formaldehyde epoxy novolac resins are disclosed to be useful in formulations for encapsulating electronic components.
摘要:
Glycidyl derivatives of compounds containing --OH, --NH.sub.2 and/or --COOH groups are prepared by reacting in the presence of a mixture of solvents, at least one of which is a polar aprotic solvent, an excess of an epihalohydrin with a compound containing --OH, --NH.sub.2 and/or --COOH groups while continuously or incrementally adding an alkali metal hydroxide to the mixture and removing water from the reaction by codistillation with epihalohydrin and the solvents.
摘要:
Compounds are prepared which have at least one aromatic cyanate group and at least one organosiloxane moiety per molecule. These compounds when cured possess excellent thermal stability, moisture resistance properties and a low dielectric constant.
摘要:
Blends containing (1) at least one compound containing an average of more than one vicinal aromatic cyanate group per molecule and at least one organosiloxane moiety per molecule and (2) at least one compound containing an average of more than one vicinal aromatic cyanate group per molecule which is substantially free of organosiloxane moieties. The compositions are useful as a component in adhesives, coatings, laminates, composites, encapsulants, filament winding, and molding.
摘要:
Compounds are prepared which contain both an organosiloxane moiety and either a phenolic hydroxyl group or an epoxide group. Also disclosed are curable and cured compositions.
摘要:
Epoxy resins have been reacted with a copolymer of a diunsaturated aliphatic compound and acrylonitrile or methacrylonitrile and a siloxane-containing polymer resulting in a rubber modified epoxy resin suitable for use in electrical and electronic component encapsulation formulations which provide such components with improved thermal shock performance. The rubber modified epoxy resins have improved flexural properties with minimal reduction in glass transition temperature.
摘要:
Adducts of metabrominated monophenols such as 3,5-dibromo-2,4,6-trimethylphenol and multifunctional epoxides such as cresol-formaldehyde epoxy novolac resins are disclosed to be useful in formulations for encapsulating electronic components.
摘要:
Epoxy resins which are relatively low in total bound halide are prepared by concurrently and continuously adding a mixture of (1) a mixture of an epihalohydrin, a compound containing an average of more than one group reactive with a vicinal epoxide group and a solvent and (2) an aqueous or organic solution of an alkali or alkaline earth metal hydroxide; to (3) a mixture of epihalohydrin and a solvent.
摘要:
The total halide content of epoxy resins is reduced by heating a resin containing undesirable halide dissolved in a solvent mixture containing at least one polar aprotic solvent in the presence of an alkali metal hydroxide for a time sufficient to reduce the total halide content.