Abstract: A process for recovering a gaseous component comprising at least one fluorine-containing compound from a mixture of gaseous compounds. The process includes, in a separation zone (12), bringing a mixture of gaseous constituents, including at least one fluorine-containing constituent, into contact with a gas permeable separating medium (16) comprising a polymeric compound, so that a first gaseous component comprising at least one fluorine-containing constituent is separated from a second gaseous component comprising the balance of the gaseous constituents. The first gaseous component is withdrawn from the separation zone as a permeate (34) or a retentate, while the second gaseous component is withdrawn from the separation zone as the retentate (26), when the first gaseous component is withdrawn as the permeate, and as the permeate, when the first gaseous component is withdrawn as the retentate.

Abstract: A process for recovering a gaseous component comprising at least one fluorine-containing compound from a mixture of gaseous compounds. The process includes, in a separation zone (12), bringing a mixture of gaseous constituents, including at least one fluorine-containing constituent, into contact with a gas permeable separating medium (16) comprising a polymeric compound, so that a first gaseous component comprising at least one fluorine-containing constituent is separated from a second gaseous component comprising the balance of the gaseous constituents. The first gaseous component is withdrawn from the separation zone as a permeate (34) or a retentate, while the second gaseous component is withdrawn from the separation zone as the retentate (26), when the first gaseous component is withdrawn as the permeate, and as the permeate, when the first gaseous component is withdrawn as the retentate.

Abstract: The invention relates to a method for producing block-shaped and plate-shaped polymethacrylimide foamed materials by copolymerizing methylacrylic acid and methylacryl nitrile, by subjecting the copolymerizate to a post-polymerization and cyclization in order to form polyimide, and by converting the same into a foamed material. The invention is characterized in that the copolymerization is carried out in the presence of a mixture containing at least three initiators with graduated half-life periods. The polymerization can be controlled especially well and yields polymerizate plates with thicknesses of up to 80 mm which can be easily foamed. The invention makes it possible to produce filling materials, especially plates and blocks containing electrically conductive particles.

Abstract: Filled plastic molded articles based on polymethyl methacrylate (PMMA), which articles resemble granite, are prepared by preparing a casting resin suspension comprising: (A) 20-80 parts by wt. (pbw) of a liquid PMMA polymer precursor; (B) 0-75 pbw of a non-metallized particulate filler; (C) 0-5 pbw, based on the sum of components (A) and (B) of a polymerizable organosilicon compound; and (D) 0-2 wt. % of at least one pigment or colorant; suspending metallic appearing particles of a platelet-like stratified silicate (SS) in the particle size range of 20-500 .mu.m in an amount of 1-35 pbw, based on the sum of components (A) and (B); polymerizing the suspension under free radical conditions in a polymerization mold; and removing the polymerized article from the mold.

Abstract: The invention relates to high filler content plastic molded articles, which articles have a surface having a pronounced glitter appearance resembling that of a microcrystalline mineral material. The glitter effect is obtained by incorporating glitter-producing particles having a plastic basis and a specific gravity <2, in the composition of said articles. A method of manufacturing such molded articles is described, according to which all of the components are adjusted to corresponding densities. The products have a particularly durable simulated-rock appearance with good glitter characteristics.

Abstract: A transparent plastic pane for an aircraft canopy consisting essentially of a copolymer of methylmethacrylate and polyfunctional acrylates, wherein the content of methylmethacrylate is greater than about 95 wt. % and the content of polyfunctional acrylates is 0.5 to 5% of the copolymer, and which is obtained by cast polymerization, whereby the temperature for final polymerization is maintained at 110.degree. C. to 130.degree. C. for at least 5 hours.

Abstract: A composition includes a polymethacrylimide polymer which is polymerized in the presence of an epoxy resin and a flame-inhibiting agent. Further, a process is described for making flame-resistant polymethacrylimide, which includes mixing an epoxy resin and a flame-inhibiting agent with a methacrylic acid and methacrylonitrile, and polymerizing. A polymethacrylimide foam so prepared has an LOI value of at least 25 and retains the good mechanical properties that are associated with polymethacrylimide foams.

Abstract: A method for the casting of highly filled plastics containing polymethyl methacrylate, the method involving:preparing a filler suspension by combining from 30 to 80 wt %, based on the amount of filler suspension, of at least one particle-shaped, inorganic filler with a polymer precursor under high-speed stirring, wherein the polymer precursor is made from methyl methacrylate and a polymethyl methacrylate prepolymer, wherein the filler suspension further contains from 1 to 20 parts by weight, based on the amount of filler suspension, of a colored, filled, comminuted polymer material having a density precisely adapted to the density of the filler suspension and wherein the comminuted polymer material contains a polymer component which is highly crosslinked; andpolymerizing the filler suspension by contacting the filler suspension with at least one radical initiator.

Abstract: A cast resin suspensions comprising:(A) 40 to 80% by weight of an inorganic filler,(B) 60 to 20% by weight of a liquid polymerizable organic monomer, and(C) 0 to 5 parts by weight based on the sum of (A) and (B) of a polymerizable organosilicon component as coupling agent,wherein inorganic filler (A) is a mixture of at least two filler particle fractions having different median particle sizes, wherein the size ratio of the average particle sizes of the large and small filler particles ranges from 10:1 to 2:1 and wherein the weight ratio of the contents of large and small filler particles is from 4:1 to 1:4.

Abstract: Color concentrates comprising a colorant such as a pigment and a polymeric binder, and polymeric binders therefor, said polymeric binders comprising:(a) 70-90 percent of methyl methacrylate, by weight of the polymer;(b) 10-20 percent of methyl acrylate; and(c) from 0 to 10 percent of at least one free radically polymerizable monomer of the formula ##STR1## wherein R.sub.1 is hydrogen or methyl and R.sub.2 is a moiety carrying a functional group.

Abstract: Opaque tinted acrylic glass produced with organic pigments or with organic dyes, which in addition to the colorant, also contains an acid in the polymer matrix, exhibits improved resistance to weathering.

Abstract: What is disclosed is an improved method for making substantially colorless polymethyl methacrylate by bulk polymerizing methyl methacrylate with an initiator which is an azo compound free of nitrile groups.

Abstract: The present invention relates to a method of manufacturing molded polymer articles comprised of casting resins and having color-differentiated surface regions, wherein prior to the charging of the casting resin, a surface region of the molding implement is coated with a hardenable coating of a colorant-containing composition, producing color-differentiation in the surface of the molded articles. The designated surface regions of the molding implement are coated with at least two layers, whereby, according to the present method, the first coating step applies a filler-containing coating dispersion (L-1) without added colorant, and the second coating step applies a colorant-containing coating (L-2) without filler. Thereafter, the coating layers are dried, the casting resin is charged to the molding implement, the resin is polymerized by heating, and the molded articles removed from the mold.

Abstract: The invention relates to electrically conducting solid plastics, the conductivity of which is attributable to their containing finely divided particulate, conducting substances. The electrically conducting solid plastics are comprised of or contain a polymer such as polymethyl methacrylate having a discrete fine-particle structure, and the polymer particles of the polymer are "doped", at least on their surface, with at least one electrically conducting substance such as carbon black in an amount which establishes electrical conductivity. The conducting substance(s) are present in the form of a plurality of conducting particulate solid bodies, and wherein the condition is imposed that the glass temperature (Tg) of the polymer is not exceeded when the conducting substance is mixed with the polymer particles.

Abstract: Rigid foamed polymethacrylimide synthetic resin containing from 0.1 to 10 percent by weight of electrically conductive particles such as conductive carbon black exhibit improved properties when used in rapidly flowing streams of gases, are particularly suitable for use as a core material in laminates for aircraft construction, and are prepared by heating a copolymer of methacrylic acid and methyacrylonitrile containing a blowing agent and conductive particles.

Abstract: Color concentrates comprising a colorant such as a pigment and a polymeric binder and polymeric binders therefor, said polymeric binders comprising:(a) 70-90 percent of methyl methacrylate, by weight of the polymer;(b) 10-20 percent of methyl acrylate; and(c) from 0 to 10 percent of at least one free radically polymerizable monomer of the formula ##STR1## wherein R.sub.1 is hydrogen or methyl and R.sub.2 is a moiety carrying a functonal group.

Abstract: The invention relates to a method of manufacturing plastic, electrically conductive pressure-formed plates from thermoplastic plastic particles which are mechanically formed. In this method, mechanically formed, thermoplastic particles each particle having maximum particle diameter in the range of about 1 mm to about 10 mm in the middle of said particle, are mechanically mixed with an amount of at least one electric-current-conducting substance sufficient to provide electrical conductivity. The electric-current-conducting substance is furnished in the form of a plurality of particulate, electrically conducting solid bodies, said mixing being effected in the temperature region below the glass temperature (Tg) of the thermoplastic plastic material of which the thermoplastic particles are comprised. The mixture thus produced is compressed to form plastic pressure-formed plates by means of a pressure-forming device.

Abstract: Curable casting resins comprising a liquid or liquefiable curable organic polymer precursor, a high content of finely divided inorganic filler, and a polymerizable organosilicon component as an adhesion promoter, the liquid phase formed from the organic components containing lecithin in amounts from 0.01 to 5 percent by weight of the casting resin.

Abstract: A method for making curable casting resins having a high content of finely divided inorganic fillers and comprising esters of acrylic or methacrylic acid and organosilicon compounds used as adhesion promoters, which method involves mixing the liquid polymer precursor comprising acrylic or methacrylic esters with the organosilicon compound and with an alkylamine as a catalyst for the organosilicon compound, the finely divided inorganic fillers being incorporated into the resulting mixture in such amounts that the viscosity of the mixture does not exceed 10 Pa.sec, the resulting thixotropic suspension then being transformed into a completely deflocculated low viscosity suspension by being allowed to stand for a sufficient length of time at room temperature or by short term heating.

Abstract: The invention relates to a method of manufacturing plastic, electrically conductive pressure-formed plates from thermoplastic plastic particles which are mechanically formed. In this method, mechanically formed, thermoplastic particles, each particle having maximum particle diameter in the range of about 1 mm to about 10 mm in the middle of the particle, are mechanically mixed with an amount of at least one electric-current-conducting substance sufficient to provide electrical conductivity. The electric-current-conducting substance is furnished in the form of a plurality of particulate, electrically conducting solid bodies, said mixing being effected in the temperature region below the glass temperature (Tg) of the thermoplastic plastic material of which the thermoplastic particles are comprised. The mixture thus produced is compressed to form plastic pressure-formed plates by means of a pressure-forming device.