Abstract: Nitrogen trifluoride (NF3) containing less than 10 parts-per-million molar impurities, e.g., tetrafluoromethane (PFC-14), is disclosed. Azeotropic and extractive distillation processes using entraining agents for separating NF3 and PFC-14 from each other and from mixtures with other electronics industry materials are disclosed.

Abstract: A process is disclosed for producing calcium fluoride. The process comprises (a) mixing phosphate rock with aqueous H2SiF6 at ambient temperature for at least one hour; (b) nucleating the calcium fluoride in the slurry prepared in step (a) by reacting the slurry at a temperature and for a time sufficient to initiate and sustain nucleation of calcium fluoride and SiO2 by-product; (c) aggregating the SiO2 by-product by heating the slurry produced in step (b) at a temperature of about 90° C. to about 105° C. for at least 0.5 hours; and (d) recovering a calcium fluoride-containing product of an average particle size of less than 1 micron.

Abstract: An improved closed cell polymer foam and foaming agent involving the use of a hydrogen-containing halocarbon blowing agent (e.g., HCFC-22) in combination with an effective amount of a hydrogen bond forming blocking agent (e.g., organic ether, ester or ketone). The presence of the blocking agent is shown to significantly reduce the escape of blowing agent from and entry of air into the foam resulting in low thermal conductivity over a longer period of time and improved thermal insulation value. The present invention further relates to compositions comprising a blowing agent and an active hydrogen-containing compound, commonly referred to in the art as B-side compositions or blends, and using such compositions for producing polyurethane and polyisocyanurate foams in which the blowing agent comprises a major proportion of 1,1,2,2-tetrafluoroethane (HFC-134).

Abstract: An improved closed cell polymer foam and foaming agent involving the use of a hydrogen-containing halocarbon blowing agent (e.g., HCFC-22) in combination with an effective amount of a hydrogen bond forming blocking agent (e.g., organic ether, ester or ketone). The presence of the blocking agent is shown to significantly reduce the escape of blowing agent from and entry of air into the foam resulting in low thermal conductivity over a longer period of time and improved thermal insulation value. A closed cell thermoplastic foam such as polyethylene, polypropylene, polystyrene, among others, is disclosed produced by means of an environmentally friendly nonflammable blowing agent substantially free of halogen substituents other than fluorine and comprising HFC-134 (1,1,2,2-tetrafluoroethane).

Abstract: A stabilized azeotrope or azeotrope-like composition is disclosed comprising an azeotrope or azeotrope-like composition of 1,1,2-trichloro-1,2,2-trifluoroethane, methanol and 1,2-dichloroethylene and about 0.001 to 0.004 wt. percent of a lower alkoxyphenol, about 0.01 to 1.0 wt. percent 1,2-butylene oxide, about 0.01 to 1.0 wt. percent diisopropylamine and at least one of about 0.01 to 1.0 wt. percent nitromethane and about 0.01 to 1.0 wt. percent 1,2-propylene oxide, said wt. percents based on the weight of the azeotrope or azeotrope-like composition.

Abstract: It is an object of the present invention to provide volatile foaming agent compositions for thermoplastic resins capable of producing a thermoplastic resin foam without any shinkage or expansion after foaming.A volatile foaming agent composition for thermoplastic resin according to the present invention comprises 1,1,1,2-tetrafluoro-ethane.As the permeability of 1,1,1,2-tetrafluoro-ethane in thermoplastic resins is smaller than that of the air, volatile foaming agent composition containing 1,1,1,2-tetrafluoro-ethane and other kind of volatile foaming agent having permeability higher than that of the air can be regulated to have the permeability similar to that of the air.Accordingly, the permeating speed of volatile foaming agent from the inside of foam cells to the outside and the permeating speed of substituting air into the foam cells from outside can be balanced and any shrinkage or expansion after foaming can be avoided.