Abstract:
A process for preparing thermoset composite articles under relatively mild conditions includes exposing a laminate containing a partially-cured thermosettable resin and a fibrous substrate to an elevated temperature which increases over time, the elevated temperature being below the glass transition temperature of the resin but sufficient to promote further curing and increase the glass transition temperature thereof to the ultimate glass transition temperature of the resin. The temperature of exposure is generally increased at a rate which maintains the temperature within about 20.degree. C. below the glass transition temperature of the thermoset-table resin, so that cure of the resin proceeds in the glassy state. The pressure during the process is generally maintained below about 50 psi and is preferably atmospheric pressure. The process enables the production of thermoset composite articles suitable for high-performance applications without lengthy autoclave treatments.
Abstract:
The preparation of solid saturated epoxy resin compositions, which when cured with conventional epoxy curing agents yield coatings exhibiting improved weatherability, i.e., better gloss retention and better chalk resistance, are described. The solid saturated epoxy resins are prepared by reacting liquid or semisolid saturated epoxy resins with a dihydroxy phenol such as resorcinol in the presence of a suitable catalyst.
Abstract:
A process is disclosed for preparing a low-chlorine epoxy resin which employs crystallization of the epoxy from solution in a finishing step of the preparation process. The process involves (a) contacting, in a basic reaction medium, epichlorohydrin and a biphenol to produce a reaction product mixture containing a diglycidyl ether of the biphenol; (b) dissolving the diglycidyl ether in an organic solvent and, optionally, contacting the diglycidyl ether with a dehydrochlorination agent; and (c) reducing the temperature of the organic solvent so as to effect crystallization of a low-chlorine fraction of the diglycidyl ether.
Abstract:
A lamp assembly which utilizes as a source of light an elongated illumination tube. This tube is fixedly mounted within a carrier housing with this housing being pivotably mounted between a pair of mounting brackets which are utilized to fixedly mount the lamp assembly at any desired location on an exterior object.
Abstract:
The physical properties of heat-cured coatings of saturated epoxy resins are significantly improved by the addition of heat stabilizers (antioxidant) and/or actinic stabilizers.
Abstract:
A process for the regeneration of a catalyst containing a metal of the group consisting of rhodium and ruthenium employed in the hydrogenation of an organic compound possessing at least one carbon-to-carbon bond unsaturation in the presence of a methylene dichloride solvent is taught whereby the catalyst is regenerated after deactivation by contacting the deactivated catalyst first with a hydrogen-containing gas then with an oxygen-containing gas and finally with a hydrogen-containing gas.
Abstract:
A polysiloxane-modified epoxy-based encapsulation composition comprising an epoxy resin, a curing agent for the epoxy resin, a polylactone-polysiloxane block copolymer, and a filler is described. The powder molding compositions provide a low internal stress epoxy composition without significantly sacrificing T.sub.g.
Abstract:
The present invention is particularly directed to a coating composition exhibiting faster cure times and improved physical properties which comprise (1) from about 60% to about 95% by weight of a saturated epoxy resin, (2) from about 5% to about 40% by weight of triglycidyl cyanurate (or triglycidyl thiocyanurate) and (3) a curing amount of an epoxy curing agent, preferably an amino-containing curing agent.
Abstract:
Stable, high-solids, low-temperature baking compositions are prepared by first reacting an epoxy resin with a polymeric fatty acid, and then reacting the resulting condensate with more than 2% by weight of a strong acid, and adding a curing amount of an amino-containing resin.
Abstract:
A polysiloxane-modified epoxy-based encapsulation composition comprising an epoxy resin, a curing agent for the epoxy resin, a polylactone-polysiloxane block copolymer, and a filler is described. The powder molding compositions provide a low internal stress epoxy composition without significantly sacrificing T.sub.g.