Showing papers by "Rhône-Poulenc published in 1979"

Catalytic preparation of ethyl acetate

Abstract: In a process for the preparation of ethyl acetate by vapor phase reaction of ethylene with acetic acid, the improvement which comprises conducting said reaction in the presence of a catalytic amount of a solid, ion-exchange fluoropolymer comprising sulfonic acid moieties.

Process for rendering polyester hollow bodies gastight

Abstract: The invention pertains to a process for producing bioriented polyester hollow bodies characterized by good gas and flavor tightness, wherein one wall of a preform is coated with an aqueous composition consisting of at least two incompatible polymers, one of which is a water soluble polyvinyl alcohol and the other, a polymer latex with low water sensitivity; the coating is dried and the preform is bidrawn-blown.

Elastomeric organopolysiloxane block copolymers and non-elastomeric organosilicic copolymer blocks therefor

Abstract: Thermoplastic, crystalline block copolymers are disclosed, each comprising a plurality of recurring units selected from the group consisting of those of the structural formulae F 1 and F' 1 , and combinations thereof: F.sub.1 : --A [SiR.sub.2 (GSiR.sub.2).sub.a ASiR.sub.2 G'SiR.sub.2 A].sub.p SiR 2 (GSiR 2 ) a ASiR 2 (OSiR 2 ) n ] and F'.sub.1 : --A [SiR.sub.2 G'SiR.sub.2 ASiR.sub.2 (GSiR.sub.2).sub.a A] p SiR 2 G'SiR 2 ASiR 2 (OSiR 2 ) n ] in which the symbols A, which are identical, represent linear or branched chain alkylene radicals having from 2 to 6 carbon atoms, or cyclohexylene radicals; the symbols R, which are identical or different, represent alkyl and halogenoalkyl radicals having from 1 to 5 carbon atoms, cycloalkyl and halogenocycloalkyl radicals having from 3 to 8 carbon atoms, aryl and halogenoaryl radicals having from 6 to 8 carbon atoms or cyanoalkyl radicals having from 3 to 4 carbon atoms; the symbols G, which are identical, represent linear or branched chain alkylene radicals having from 1 to 8 carbon atoms, divalent organic radicals corresponding to the formula F 2 : --CH 2 ) x QTQ(CH 2 -- x , in which the symbols Q, which are identical, represent one of the groups --O-- and --OCO--, the --OCO-- being bonded to T by the --CO-- radical, the symbol T represents a monocyclic, divalent hydrocarbon radical having from 6 to 8 carbon atoms, or a divalent organic radical which has from 10 to 22 carbon atoms and consists of 2 hydrocarbon rings which are fused to one another or bonded together by a valence bond or by one of the groups of the formulae --O--, --CH 2 --, --C(CH 3 ) 2 -- and -Si(R'-- 2 , wherein R' is an alkyl radical having from 1 to 3 carbon atoms, and the symbols x, which are identical represent 1, 2 or 3, or divalent hydrocarbon radicals corresponding to the formula F 3 : --CH 2 ) b T(CH 2 ) b , in which the symbol T has the measuring given for the formula F 2 and the symbols b, which are identical, represent 0 or 1; s the symbols G', which are identical, have the meaning given above for G, except that they do not correspond to the formula F 2 ; the symbols a, which are identical, represent 0 or 1; the symbols p represents any number ranging from 1 to 120; and the symbol n represents any number ranging from 1 to 1,500.

Preparation of Catalysts by Adsorption of Metal Complexes on Mineral Oxides

Abstract: The preparation of dispersed metal supported catalysts by adsorption of metal complexes on oxides has led us to analyze the phenomena occurring at the interface oxide-solution. This analysis is based on simple principles such as surface polarization of oxides versus pH and adsorption of counterions by electrostatic attraction. The three most important parameters which seem to rule the adsorption phenomena are: isoelectric point of the oxide, pH of the aqueous solution, and nature of the metal complex. This simplified approach toward adsorption phenomena is in agreement with the results in literature concerning the fixation on alumina or silica carriers of chlorometallic and amine complexes of metals belonging to 7a, 8 and 1b groups. An extension of this analysis to other mineral oxides is proposed.

Synthetic amorphous silica for elastomeric reinforcement and methods therefor

Abstract: A synthetic amorphous silica having a CTAB surface area of from about 80 to about 125 m 2 /g and a structure index of at least 0.80 is disclosed as adapted for the reinforcement of elastomeric materials, as well as methods for the preparation thereof.

Apparatus for the thermal conversion of gypsum

Abstract: An apparatus for effecting the thermal conversion of gypsum to calcium sulfate hemihydrate includes a reactor having a series of fluidized bed compartments containing separate heat exchangers and defined by partitions each provided with an opening which is selected so that the material undergoing treatment progresses, without return movement, through the series of fluidized bed compartments. The apparatus is further constructed so as to permit recycling of fine gypsum particles from the outlet to the middle of the reactor.

Two-component mixed acrylic fibres wherein acrylic components have different amounts of non-ionizable plasticizing comonomer

Abstract: The present invention relates to two-component acrylic fibres and yarns and their process of preparation. They consist of two copolymers based on acrylonitrile, in which the proportion of plasticizing comonomer differs by between 4 and 15% and which contain a total number of milliequivalents of acid of at least 50 per kg of polymer; they comprise a mixture of monolaminar, bilaminar and multilaminar strands; they possess a crimp, the direction of which depends on the heat and/or mechanical treatments to which they have been subjected, component B, which contains the smaller proportion of plasticizing comonomer, being located on the inside of the helix formed by the filaments, after treatment, without tension, at a temperature which is below about 110° C. and at least equal to ambient temperature, and being located on the outside of the helix after treatment under tension or after heat treatment at a temperature above 110° C., and the contraction and the crimp spacing varying from one strand to the next and along one and the same strand. The yarns and fibres according to the invention can be used in all the known textile-converting techniques, namely stretch-breaking, converting, carding and the like.

Process for the regeneration of polymer from waste

Abstract: A process is disclosed for the production of a polymer of good spinnability from waste. It consists in compressing the finely chopped waste by means of a screw until a bulk density of at least 500 kg/m3 is reached, introducing same into a double screw degassing extruder, and subjecting the molten polymer to a post-condensation operation. The polymer obtained can be used as such in many textile applications and in plastics.

Process for the manufacturing of bioriented hollow bodies

Abstract: The invention pertains to the manufacture of hollow bodies such as bottles for packaging pressurized or flavoring liquids by a blowing process according to which a preform of a polyester with a polyvinyl alcohol coating is used.

Method for intimate contacting of plural phases and phase contactor apparatus therefor

Abstract: Intimate contacting of plural, physically disparate phases is achieved by establishing a current of axially extending, axially symmetrical helical flow of a first phase; separately establishing a current of coaxially extending, rectilinear flow of a physically disparate second phase, the currents of said first and said second phases being maintained physically separated from each other; circulating and directing said currents which comprise the plural phases to a zone of restricted flow passage with respect to said helical flow, whereby said plural currents converge and are intimately, homogeneously admixed and whereas such zone of convergence the momentum of the first phase helical flow is at least 100 times greater than the momentum of the second phase, coaxial rectilinear flow; and thence abruptly changing the velocity field of at least one of said plural phases, while at the same time maintaining the general direction of flow of said admixed plural phases, and whereby phase separation of the product of admixture results enabling easy recovery thereof. Such intimate contacting is especially desirable for concentrating dilute solutions of phosphoric acid with hot air.

Fibrous padding material and process for its manufacture

Abstract: PCT No. PCT/FR78/00001 Sec. 371 Date Feb. 8, 1979 Sec. 102(e) Date Feb. 8, 1979 PCT Filed June 2, 1978 PCT Pub. No. WO 78/00012 PCT Pub. Date Dec. 21, 1978 A fibrous padding material simulating natural down for quilted articles. The material is in the form of an element of defined length and of low thickness relative to its width, which element comprises a central filiform core which is relatively dense and rigid compared with the whole of the material and to which are bonded fibers which are oriented substantially transversely relative to this core, the said fibers being entangled with one another so as to form a homogeneous thin web and being located on either side of the core, substantially in the same plane (FIG. 3). Process for the manufacture of the material, in which a fibrous web is formed in a known manner, a plurality of spaced-out heat-weldable thread is superposed onto at least one of the faces of the said web, the spaced-out threads are caused to bond to the fibrous web, the web is divided into strips on either side of each thread and, finally, said strips, thus formed, are cut into elements of defined length (FIG. 1). The division of the web into strips is preferably performed by passing the threads through eyelets after the threads have been combined with the fibrous web. The web can also be divided by cutting (FIG. 1).

Production of spheroidal alumina shaped articles

Abstract: Spheroidal alumina shaped articles are prepared by dispersing an ungelled admixture of an alumina sol and hexamethylenetetramine, in the form of droplets, into a liquid forming medium which is but very slightly miscible with water, said medium being at a temperature of between about 50° and 105° C., next aging the alumina spheres thus shaped at a temperature greater than about 105° C. at superatmospheric pressure, then secondarily aging said alumina spheres in a basic medium, and thence washing, drying and calcining said aged alumina spheres. The resultant shaped articles are useful, e.g., catalysts or catalyst carriers/supports.

Process for the stereoselective synthesis of the E isomer of aryl alkyl oximes

Abstract: Mixtures of the E and Z isomers of aryl alkyl oximes are converted to 98% or greater E isomer by a process comprising treating a solution of a mixture of E and Z isomers in an organic solvent with a protic or Lewis acid, under anhydrous conditions, to precipitate >98% pure E isomer of an immonium complex and neutralizing the precipitate with an excess of dilute organic/inorganic base, such as Na2CO3 or NaHCO3. The E isomer of the ketoxime is precursor for highly insecticidal ketoximinoethers.

Detergent compositions comprised of non-abrasive siliceous scouring agents

Abstract: Detergent compositions comprised of conventional detergent ingredients and additives include a non-abrasive silica scouring agent having a B.E.T. surface area of between 80 and 150 m2 /g, and desirably a C.T.A.B. surface area below 45 m2 /g and a porosity on the mercury porosimeter below 20 cm3 /g.

Cross-linkable saturated powderous compositions and powderous painting and coating compositions containing same

Abstract: A saturated cross-linkable binder composition adapted for preparing coatings having a non-glossy surface is disclosed which comprises: (a) at least one cross-linkable resin selected from the group consisting of saturated polyester resins and epoxide resins; (b) a cross-linking agent wherein the functional groups are selected from the group consisting of acid groups and acid anhydride groups and, in case the cross-linkable resin is a saturated polyester resin, also masked isocyanate groups; and, (c) having associated therewith a salt of an at least bivalent metal ion and an organic acid anion selected from the group consisting of carboxylic anions and acetylacetonate. These binder compositions are particularly useful as binding agents in powderous paint compositions which yield a paint coating having a non-glossy and textured surface.

Organopolysiloxane elastomer-forming compositions and their use in mould making

Abstract: Organopolysiloxane compositions comprising, per 100 parts by weight of an alpha , omega - dihydroxydiorganopolysiloxane oil having a viscosity of 600 to 100,000 mPa.s at 25 DEG C, 1.5 to 12 parts of trialkoxysilanes or tetraalkoxysilanes or products resulting from the hydrolysis of tetraalkoxysilanes, 10 to 150 parts of fillers, dihydroxypolysiloxane oils having a viscosity of 10 to 350 mPa.s at 25 DEG C and catalysts (R''COOO)2SnQ2 wherein R'' is an aliphatic hydrocarbon and Q an alkyl radical are characterised in that the oils having a viscosity of 10 to 350 mPa.s are used at a rate of 7 to 23 parts per part of tin, and in that the catalysts are introduced so as to provide 0.22 to 1 part of tin per 100 parts of the compositions. These compositions are used for the production of moulds, in particular for moulding polyurethanes.

Apparatus for regulating the speed of a member delivering or winding a yarn

Abstract: The yarn is formed into a loop and a loop sensor monitors the variations in length in the loop of yarn. The variations in the size of the loop result from a difference in the speed between the speed of the yarn and the speed of the draw-off or delivery member. The draw-off or delivery member is driven by an asynchronous motor having a slip-clutch drive with an assembly for braking in response to eddy currents. In particular, a disc is connected to the motor and a magnetic field is applied to the disc, the magnitude of the field which is applied to the disc directly dependent upon the size of the loop. In the preferred embodiment, the regulation of the speed of a pilot roller of a winder as a function of the delivery speed of the yarn is accomplished.

Device for treating substances of different phases such as liquid, semi-liquid or pasty substances, by another phase, particularly a gaseous phase

Abstract: 1. Apparatus for treating substances in the form of a liquid, semi-liquid or pasty phase, with another phase, in particular a gaseous phase, comprising a combustion chamber (1) and a contacting chamber (2), said combustion chamber comprising a casing (3) which is closed in its upper portion by an end plate (4), an annular space (6) which is delimited internally by an internal perforated wall (7), a restricted passage (10), at least one conduit (8) for the tangential feed of a gaseous phase, and a means (5) for axial injection of the fuel through the end plate (4), characterized in that the casing (3) terminates at the downstream end with a convergent portion (9) in which an injection device (11) terminates substantially at the level of the restricted passage (10), on the axis of rotation of the combustion chamber (1), the contracting chamber (2) extending the combustion chamber (1) in a downstream direction on the same axis of rotational symmetry.

Device for controlling the take-up speed of a winding frame

Abstract: The invention relates to a device for controlling the take-up speed of a winding frame for textile yarns, which winding frame has peripheral drive by means of a pilot roller and axial drive by means of a gas turbine integral with the spindle which carries the winding. The device acts when the winding is out of contact with the pilot roller. The control device includes: a calculating unit which, using pulses originating from the pilot roller, emits pulses at a required frequency of the spindle, and a frequency comparator which compares the frequency of pulses originating from the rotating spindle with the required frequency, and which, from the comparison, controls a device for regulating the fluid supply of the turbine. Several winding frames can be simultaneously controlled. The device can be used to provide the spindle with an overspeed at the start of winding, in order to avoid drops in tension.

Method and apparatus for the treatment of heat-sensitive materials

Abstract: The drying and dehydration of heat-sensitive materials is improved by submitting such materials to a second thermal treatment following their initial flash treatment. The method is particularly applicable to the treatment of foodstuffs.

Pressure compacting of settable gypsum/plaster compositions

Abstract: A settable molding composition comprising a mix of gypsum, plaster, water [which may be provided in whole or in part by utilizing a "wet" gypsum component] and an essentially water-insoluble metallic salt of an organic fatty acid [the "waterproofing" agent] is readily pressure compacted or molded into a variety of useful shaped articles, e.g., modular constructional units and other load-bearing members. The resultant shaped articles are highly water repellent, display excellent mechanical properties, are effectively set even in the absence of any drying step, and are even well suited for certain building elements adapted to be exposed to an outside environment.

Process for the preparation of crystalline, alkaline, aluminosilicate

Abstract: A crystalline, alkali metal aluminosilicate of type 4A is prepared by reaction between an aqueous solution of an alkali metal silicate and an aqueous solution of an alkali metal aluminate, and includes the steps of (i) introducing a flow of at least a portion of at least one of said reactant solutions into a reaction zone; (ii) co-introducing with said flow (i) an in line flow of at least a portion of the other reactant solution into said reaction zone; (iii) thus establishing in said reaction zone a liquid mixture of said aqueous reactant solutions and said liquid admixture comprising a gel-formation medium; (iv) establishing gel-formation elevated temperatures within said gel-formation medium to effect formation of a mixture comprising an aluminosilicate gel-phase and a mother liquid; (v) recycling said gel-phase/mother liquor to said flow (i); (vi) maintaining said gel-phase comprising said gel-formation medium under such elevated temperatures for such period of time as to effect crystallization of the aluminosilicate, and whereby a suspension of aluminosilicate crystals of type 4A in liquid phase results; and (vii) thence recovering said aluminosilicate crystals from said resulting liquid phase. The resultant aluminosilicate crystals are useful, e.g., detergent additives.

Enzyme-support complexes

Abstract: Enzyme-support complexes in which the enzymes are bound by covalent bonding to at least one reactive function of organic groups grafted to mineral supports by at least one ester bond. The complexes are obtained by reacting an insoluble inorganic support having hydroxyl groups with a compound formed of an organic group having at least one alcohol or phenol function and at least one reactive function, to which the enzyme is then bonded.

Stabilization of anhydrous sodium metasilicate

Abstract: Anhydrous sodium metasilicate is stabilized against attrition or "dusting" in detergent and other use, by formulating same with such amount of an additive, e.g., a hydrate, that will transfer water content to the anhydrous metasilicate, at a temperature less than the fusion temperature of sodium metasilicate pentahydrate and as will convert from about 1% to 20% by weight of said anhydrous metasilicate into its pentahydrate form.