Abstract: Molding compositions, easily shaped into useful articles having improved mechanical properties that are less anisotropic, contain (a) a thermotropic polymer, and (b) an inorganic filler material, such inorganic filler (b) being a crystalline inorganic filler of platelet shape having a mean diameter ranging from 0.5 to 400 .mu.m and a shape factor represented by the ratio: ##EQU1## which ranges from 10 to 90, and such inorganic filler (b) being present in an amount, expressed in % by weight of filler in the combined polymer+filler, ranging from 20% to to 60%, with the proviso that such amount ranges from above 50% to 60% when the mean particle diameter of the filler material is less than 20 .mu.m.

Abstract: Smooth, thin, dimensionally stable, essentially circular and planar injection-molded disc members, well adapted as substrates for magnetic recording discs, e.g., by providing same with an effective recording amount of a magnetic coating material on at least one of the face surfaces thereof, comprise a radially molecularly oriented thermotropic polymer, desirably having a flow temperature ranging from 200.degree. C. to 350.degree. C. and an inherent viscosity of at least 1 dl g.sup.-1.

Abstract: Rigid, dimensionally stable, essentially circular and planar, axially injection-molded disc members, well adapted as support substrates for radiation sensitive layers for optical discs, e.g., laser discs, comprise radially molecularly oriented thermotropic polymers and such disc members have a radiation-sensitive microrelief pattern on at least one of the face surfaces thereof.

Abstract: High molecular weight thermotropic aromatic copolyesteramides which can be molded/extruded into a wide variety of useful shaped articles having improved thermomechanical properties are comprised of recurring structural units of the formulae (I), (III) and (IV), and optionally (II), wherein:(I) represents the structure: ##STR1## in which R.sub.1 is a methyl or ethyl radical or a chlorine or bromine atom, with the proviso that the units (I) may be identical or different,(II) represents the structure: ##STR2## (III) represents the structure: ##STR3## in which n is an integer from 2 to 6, with the proviso that the units (III) may be identical or different,(IV) represents the structure: ##STR4## the molar ratio of the units (I) relative to the sum of the units (II)+(III) ranges from 0.95 to 1.

Abstract: High molecular weight thermotropic aromatic copolyesteramides which can be molded/extruded into useful shaped articles having improved mechanical properties are comprised of recurring structural units of the formulae (I), optionally (II), (III) and (IV): ##STR1## and have yield temperatures ranging from 200.degree. to 350.degree. C.

Abstract: High molecular weight thermotropic copolyesters and copolyesteramides which can be molded/extruded into a wide variety of useful shaped articles having improved thermomechanical properties are comprised of recurring structural units of the formulae (I), (II), (III) and (IV), wherein ##STR1## in which the symbol A is an oxygen atom or the NH group; the molar ratio of the units (I) relative to the sum of the units (II)+(III) ranges from 0.95 to 1.05;the amount of the units (II) in the mixture of (II)+(III) ranges from 20 to 90 mol % and that of the units (III), on the same basis, ranges from 80 to 10 mol %;the amount of the units (IV), expressed relative to the amount of the units (I), ranges from 25 to 300 mol %; andsaid copolyesters and copolyesteramides have a flow temperature ranging from 200.degree. to 350.degree. C.

Abstract: High molecular weight thermotropic aromatic copolyesteramides which can be molded/extruded into a wide variety of useful shaped articles having improved thermomechanical properties are comprised of recurring structural units of the formulae (I), optionally (II), (III) and (IV), wherein: ##STR1## in which R.sub.1 is a methyl or ethyl radical or a chlorine or bromine atom, with the proviso that the units (I) may be identical or different; ##STR2## the molar ratio of the units (I) relative to the sum of the units (II)+(III) ranges from 0.95 to 1.05;the amount of the units (II) in the mixture of (II)+(III) ranges from 0 to 80 mol % and that of the units (III), on the same basis, ranges from 100 to 20 mol %;the amount of the units (IV), expressed relative to the amount of the units (I), ranges from 5 to 100 mol %; andsaid copolyesteramides have a flow temperature ranging from 200.degree. to 350.degree. C.

Abstract: High molecular weight thermotropic aromatic polyesters having flow temperatures ranging from 200.degree. to 350.degree. C., and well adopted for molding into mechanically improved shaped articles, e.g., fibers and films, are comprised of recurring structural units of the formulae (I), (II), (III) and (IV), wherein (I) is the structural unit: ##STR1## in which R.sub.1 is methyl, ethyl, chlorine or bromine, said structural units (I) either being identical or different; (II) is the structural unit: ##STR2## (III) is the structural unit: ##STR3## (IV) is the structural unit: ##STR4## and further wherein the molar ratio of the structural units (I) relative to the total amount of the structural units (II)+(III) ranges from 0.95 to 1.

Abstract: Composition for coating a biologically active substance, which is stable in a medium of which the pH is greater than or equal to 5, and which permits the release of the active substance in a medium of which the pH is less than or equal to 3.5, and biologically active substances when surrounded by this composition.

Abstract: A process for preparing membranes for electrolysis. One such process comprises impregnating a porous sheet comprising a polyfluoroolefin, asbestos fibers and an inorganic pore-forming agent with a solution comprising (i) a compound selected from the group consisting of acrylic acid and methacrylic and (ii) at least one other non-ionic monomer having at least one >C.dbd.CH.sub.2 group, withdrawing said sheet from contact with said solution, polymerizing the monomers which become impregnated in the sheet so that the pores of the sheet contain the resulting acrylic polymer, eliminating the inorganic pore-forming agent to form pores in the sheet, and swelling the acrylic polymer so that the pores of the sheet are closed by the polymer. The membranes produced by these processes are useful in cells for the electrolysis of sodium chloride to produce chlorine and sodium hydroxide.

Abstract: A polymer is disclosed having ion exchange properties, and characterized by the presence of units of the formula: ##STR1## optionally associated with units of the formula: ##STR2## in which: R.sub.1 and R.sub.2, which may be identical or different, represent a hydrogen atom or a methyl radical;E represents a divalent radical consisting of the nucleus system of a polynuclear diphenol in which the hydroxyl group are attached to different nuclei;x and n are positive integers; andM.sup.n+ represents a cation of valency n.

Abstract: Membranes which are particularly suitable for use in selective dialysis are described. These comprise:A. an anion exchange polymer in the form of particles of diameter from 5 to 500 .mu.;B. a cation exchange polymer in the form of particles of diameter from 5 to 500 .mu.; andC. a non-ionic film-forming polymer binder, the percentage by weight of binder not exceeding 50%, the polymers (a), (b) and (c) being insoluble in water, and the anion exchange and cation exchange polymers (a) and (b) being insoluble in at least one solvent for polymer (c), and each polymer having an ionic conductivity .lambda. and a permeability U to non-electrolytes such that .lambda./U>20.

Abstract: Novel sulphonated polyaryl-ether-sulphone resins are described which are particularly suitable for producing semi-permeable membranes, in particular for reverse osmosis. These resins consist essentially of a plurality of units of the formula: ##STR1## and, optionally, a plurality of units of the formula: ##STR2## in which A.sub.1, A.sub.2, A.sub.3, A.sub.4 and A.sub.5 each represents a phenylene radical at least one of which is substituted by an optionally salified sulpho (--SO.sub.3 H) radical, the relative proportions of units of formula (I) and (II) and the degree of substitution by sulpho radicals being such that the number of sulpho groups is from about 0.1 to about 5 milliequivalents per gram of dry resin.

Abstract: An alkenylaromatic polymer is provided derived from 50 to 100 mol % of at least one monomer of the general formula: ##STR1## in which R' represents a hydrogen atom or a methyl radical and R" represents a hydrogen atom or a methyl or ethyl radical, and 0 to 50 mol % of a non-aromatic ethylenically unsaturated monomer, optionally cross-linked by 0.1 to 30 mol %, relative to the monomer of formula (I), of a polyvinyl monomer, 0.01 to 1 .alpha.-ketoaldehyde group of the formula-- CO -- CHO II.being present per aromatic ring in the polymer. These polymers find particular utility in extracting sulphur and nitrogen-containing compounds from solutions containing them, especially urea from solutions resulting from the dialysis or ultrafiltration of human blood.

Abstract: An alkenylaromatic polymer is provided derived from 50 to 100 mol % of at least one monomer of the general formula: ##SPC1##In which R' represents a hydrogen atom or a methyl radical and R" represents a hydrogen atom or a methyl or ethyl radical, and 0 to 50 mol % of a non-aromatic ethylenically unsaturated monomer, optionally crosslinked by 0.1 to 30 mol %, relative to the monomer of formula (I), of a polyvinyl monomer, 0.01 to 1 .alpha.-ketoaldehyde group of the formula-- CO -- CHO (II)being present per aromatic ring in the polymer. These polymers find particular utility in extracting sulphur and nitrogen-containing compounds from solutions containing them, especially urea from solutions resulting from the dialysis or ultrafiltration of human blood.