Abstract: In a process for separating liquid mixtures comprising formaldehyde, trioxane, alcohol, hemiformal formed from the formaldehyde and the alcohol, usual minor components and up to 5% by weight of water, the liquid mixture is distilled batchwise or continuously at reduced pressure, atmospheric pressure or superatmospheric pressure in suitable apparatuses which are to be connected to one another in an appropriate manner, and the trioxane is produced in very high purity. The other materials of value, formaldehyde and alcohol, present in the mixture can likewise optionally be separated off and recycled or used otherwise, while the minor components are ejected.

Abstract: A process for preparing aluminum salts (I) of dialkylphosphinic acids or (formula (II)) of alkylated diphosphinic acids where R1 and R2 are a linear or branched C1-C8-alkyl radical and R3 is a linear or branched C1-C10-alkylene radical or an arylene radical or an alkylarylene radical or an arylalkylene radical, which comprises reacting a dialkylphosphinic acid ester of the formula (III) or a diphosphinic acid ester of the formula (IV) where R1, R2 and R3 are as defined above and R4 is a linear or branched C1-C8-alkyl radical, in the presence of a saturated aliphatic monocarboxylic acid having a total of from 1 to 7 carbon atoms, with aluminum hydroxide at a temperature of from 150 to 350° C.

Abstract: The invention concerns a process for preparing salts of organic acids of phosphorus. The organic acid is reacted with aluminum hydroxide in the presence of a polar solvent selected from acetic acid, propionic acid, methanol, ethanol, n-propanol, isopropanol, butanol, acetone, methyl ethyl ketone, tetrahydrofuran, dioxane, and acetonitrile.

Abstract: The invention relates to a sensor comprising a piezoelectric crystal with a polyarylene thioether-containing coating, the coating containing at least one polyarylene system having repeating units of the formula I, —[(Ar1)n—X]m—[(Ar2)i—Y]j—[(Ar3)k—Z]l—[(Ar4)o—W]p—  (I) which contain at least one thioether group, in which Ar1, Ar2, Ar3 and Ar4 are identical or different aryl systems having from 6 to 18 carbon atoms, W, X, Y and Z are identical or different linking groups, selected from the group comprising —SO2—, —S—, —SO—, —O—, —CO—, —CO2—, alkylene or alkylidene having from 1 to 6 carbon atoms and —NR1—, where R1 is an alkyl or alkylide group having from 1 to 6 carbon atoms and at least one linking group must be —S—, n, m, i, j, k, l, o, p are, equal or different, integers zero, 1, 2, 3 or 4, their sum havin

Abstract: A process for the cationically initiated preparation of oxymethylene copolymers in which, after the polymerization and after comminution of the crude polymer in a grinding assembly a portion of the deactivation suspension comprising the ground crude polymer is removed downstream of the grinding assembly and fed back to the process upstream of the grinding assembly. The return procedure predominantly reduces the proportion of oversize while the proportion of undersize rises only insignificantly. The treated crude polymer also has a lower proportion of unstable chain ends.

Abstract: The present invention relates to a method of triboelectric separation of organic polymers and salts, specially organic polymers containing sulfur, such as polyarylene sulfides and a halogenide or a carboxylate of alkaline metals, alkaline earth metals, ammonium or substituted ammonium wherein: a) the mixture to be separated is electrically charged; b) the charged particles are moved by an electric field, preferably perpendicular to the direction of the field, and c) the particles varyingly deviated in the electric field are separated and captured.

Abstract: Polymer mixtures comprising at least one thermoset and at least one oxidized polyarylene sulfide have particularly good tribological behavior. Oxidized polyarylene sulfides used in these mixtures are polyarylene sulfones or oxidized polyarylene sulfides in which at least 10% of the sulfur bridges have been converted to sulfone bridges. Polyphenylene sulfone is employed with preference. The polymer mixtures are used to produce gearwheels, gear racks, bearings, chains, wheels or gasket materials.

Abstract: The present invention relates to an absorbent comprising at least one cycloolefin copolymer which contains polymerized units which are derived from at least one cyclic and at least one acyclic olefin.

Abstract: An oriented film composed of thermoplastic polymers is described which comprises at least one vacuole-containing layer. The vacuole-containing layer comprises particulate hollow bodies which are essentially composed of a polymer which is incompatible with the thermoplastic polymer. A process for producing the film is also described.

Abstract: The invention relates to a method for separating a gaseous mixture comprising formaldehyde and trioxane, wherein at least some of the formaldehyde and the trioxane are dissolved from the mixture in a alcohol-containing liquid and the trioxane is crystallized from the solution thus obtained and is separated.

Abstract: Process for the preparation of a catalyst component for the polymerization and copolymerization of ethylene to give ultrahigh-molecular-weight ethylene polymers. Reaction of a Grignard compound with a halogenating agent, a titanium compound, a perhalogen compound and an electron-donor compound and subsequent comminution of the resultant solid to a mean particle size of from 0.5 to 5 .mu.m gives a catalyst component which, together with an organoaluminum compound, results, in the polymerization and copolymerization of ethylene, in ultrahigh-molecular-weight ethylene polymers having a mean particle diameter of from 50 to 200 .mu.m and a viscosity index of greater than 2,000 cm.sup.3 /g. The mean particle diameter can be adjusted by means of the catalyst particle diameter and by means of the catalyst productivity.

Abstract: Polymeric coating systems comprising an oxidized polyarylene sulfide, especially polyarylene sulfone or partially oxidized polyarylene sulfide, are of improved abrasion resistance. The coating systems preferably comprise a polymer, a binder resin and oxidized polyarylene sulfide, and are suspended in a liquid vehicle. The coating systems are used for coating the surface of metallic and nonmetallic substrates.

Abstract: This invention relates to a method for producing aluminum phosphinates of the formula [R.sub.1 R.sub.2 P(O)O.sup.- ].sub.3 Al.sup.3 +, where R.sub.1 and R.sub.2 are the same or different and represent a C.sub.1-8 alkyl group or a phenyl group. The process involves reaction of the corresponding alkali metal phosphinate with aluminum sulfate. The aluminum phosphinate salts are useful as a flame retardant for plastics.

Abstract: Salts of 1-hydroxydihydrophosphole oxides and 1-hydroxyphospholane oxides and use thereof as flame retardants. The salts of 1-hydroxydihydrophosphole oxides and 1-hydroxyphospholane oxides are useful as flame retardants, especially for plastics such as polyester or polyamide. The aluminum salts are preferred.

Abstract: A copolymer comprisinga) a segment A with a number-average molar mass Mn of from 1000 to 20,000 g/mol, which hasi) units 1, which have been derived from structures of the formula (I) ##STR1## where the radicals R.sup.1 and R.sup.2, independently of one another, are a hydrogen, fluorine, chlorine or bromine atom or a branched or unbranched alkyl or alkoxy radical having from 1 to 6 carbon atoms; and/orii) units 2, which are derived from structures of the formula (II) ##STR2## and b) a segment B, derived from a polyarylene sulfide structure of the formula (IV) ##STR3## where Ar is an aromatic radical, or more than one condensed aromatic radicals, and n is a number from 2 to 100, in particular from 5 to 20, together with a process for its preparation, and also its use for compatibilizing blends made from polyarylene sulfides and aromatic polyesters.

Abstract: A polyolefin film which includes at least one layer containing polyolefin and cycloolefin polymer (COP), where the cycloolefin polymer is amorphous and has a mean molecular weight M.sub.w in the range from 200 to 100,000, and this mean molecular weight M.sub.w of the cycloolefin polymer is at most 50% of the mean molecular weight M.sub.w of the polyolefin, and the cycloolefin polymer is a homopolymer or a copolymer containing at most 20% by weight of comonomer.

Abstract: The present invention relates to a process for obtaining polyarylene sulfide from polyarylene sulfide-containing material. For this purpose, the polyarylene sulfide-containing material is treated with a solvent in which it dissolves, and is subsequently reprecipitated. The invention also relates to the purification of polyarylene sulfide-containing material by separating off extraneous substances, to polyphenylene sulfide particles having a specific surface area of at least 80 m.sup.2 /g and to their use as filter material.

Abstract: The present invention relates to a flame-retardant thermoplastic molding composition obtained by treating a mixture containing from 60 to 90% by weight of a thermoplastic polyester and from 10 to 40% by weight of aluminum hydroxide at from 230 to 330.degree. C. under subatmospheric pressure, where from 0.9 to 1.2 mol of water is removed per mole of aluminum hydroxide used.

Abstract: Thermoplastic molding compositions which comprise an oxidized polyethylene have high abrasion resistance and permit a less severe reduction of elongation at break at the frequently unavoidable weld lines. The molding compositions have low static friction. They are therefore used in articles which have a tight fit but are nevertheless readily separable, and also for low-friction and wear-resistant articles which require to slide.

Abstract: Oxidation product of polyarylene sulfides comprising recurring units of the formula.brket open-st.C.sub.6 H.sub.4 --S.brket close-st. (I)in the form of a compound comprising recurring units of the formula.brket open-st..paren open-st.C.sub.6 H.sub.4 --S.paren close-st..sub.a .paren open-st.C.sub.6 H.sub.4 --SO.paren close-st..sub.b .brket close-st.(II)in which the sulfur/oxygen ratio is from 1:0.1 to 1:1, the sum of a and b always being 1 and a and b each being greater than zero or with the proviso that a is zero if b is 1.