Abstract: Diaphragms for electrolytic cells are prepared by depositing onto a cathode screen, discrete thermoplastic fibers. The fibers are highly branched, and when deposited, form an entanglement or network thereof, which does not require bonding or cementing.

Abstract: There is used a structure modified so that the brine-introduction tube is mounted within a larger-diameter tube sealingly mounted in the brine-introduction opening in the side of the cell top, with an orifice member preferably being mounted within an end of the brine-introduction tube nearer to the cell. This makes it possible to avoid unwanted variations in the brine flow rate and to see instantly whether an orifice member is clogged.

Abstract: Synthetic-fiber diaphragms are further improved by incorporating in the diaphragm an effective proportion of a suitable inorganic material such as TiO.sub.2, BaSO.sub.4 or K.sub.2 Ti.sub.8 O.sub.17, which is more hydrophilic than the fluoropolymer forming the diaphragm. This is done either by mixing the inorganic material with the resin before it is made into fiber or by supplying sub-micron-sized particles of the inorganic material, during or even after diaphragm formation. A principal benefit is that this lowers the cell voltage which is required during an initial period (up to about 300 hours) of the operation of a chlor-alkali cell provided with such a diaphragm, making it possible to avoid such drawbacks as suffering an initial period of low production or the necessity of providing external cooling to the cell during such an initial period.

Abstract: Fibers about micron size in cross-section of certain fluorine-containing polymers can be treated after being deposited as a diaphragm, either during operation or separately before installation, so that they develop a 0.25-millimeter-thick ply on either side of a central body which is substantially different in chemical composition. This yields a diaphragm 1 to 5 millimeters thick which has a Mullen burst strength approximately three to five times greater than that of an untreated diaphragm (20-25 pounds per square inch versus 5 to 7 pounds per square inch) and a remarkably improved service life in the treated diaphragm (200 days and up) in comparison with such untreated diaphragm (30 days or less). Use of a polymer based upon a major proportion of chlorotrifluoroethylene appears to be required. This discovery is economically significant, in that it is an essential element in the technology of the replacement of asbestos diaphragms now used with a synthetic material.

Abstract: There is practiced a four-step procedure, according to which the acrylamide or the like and, if desired, other ingredients, is first polymerized in a water-in-oil emulsion where the oil phase consists of a hydrocarbon solvent in the presence of an appropriate quantity of suitable surfactant so as to produce particles of a desired size, then water is azeotropically removed, and then a suitable glycol or glycol ether is added, following which the hydrocarbon solvent used in the polymerization reaction is removed. This makes it possible to obtain a composition of matter which contains at least 10 weight percent of active flocculant ingredient, and more usually about 20 percent, suspended in a medium which is entirely water-soluble. Such flocculant compositions dissolve readily in water, yet they can be obtained, according to the method of the invention, in a manner considerably less expensive than any process which necessitates the grinding of a solid flocculant material into finely divided form.

Abstract: Diaphragms for electrolytic cells are prepared by depositing onto a cathode screen, discrete thermoplastic fibers. The fibers are highly branched, and when deposited, form an entanglement or network thereof, which does not require bonding or cementing.

Abstract: As a spin-finish lubricant for processing synthetic fibers, a nonionic polyalkoxylate surfactant of the fatty-ether alkoxylate, fatty-ester alkoxylate, or block or heteric ethylene oxide/propylene oxide type is made which contains a substantial proportion of alkali-metal or alkaline-earth metal ions and preferably anions of volatile nature, such as the anions of saturated carboxylic acids containing up to 18 carbon atoms. Such lubricants display improved stability when during a spin-finishing operation the synthetic fiber to which they have been applied is passed over a heater plate maintained at 150.degree. to 300.degree. Centigrade.

Abstract: A practical method of electrolyzing sodium chloride brine on a commercial scale, obtaining in good yield a caustic product exceptionally low in salt content, is provided. The process necessarily involves working with a brine of lower calcium-ion content than is ordinarily used, using dimensionally stable anodes, using, preferably but not necessarily, a heat-treated ion-exchange membrane as a separator within the cell, and periodically taking action to reduce the cell voltage, by reducing the current or interrupting it, alone or with a concomitant flushing of the catholyte portion of the cell.

Abstract: This invention deals with porous, substantially foam-free composite material of grainy solid material particles of a certain grain size, which is solidified with a binder mixture of isocyanate-group-containing prepolymers, water, and possibly auxiliaries, and the manufacture and application of such products.

Abstract: The invention concerns a process for making heat-resistant polyurethane elastomers from substantially linear polyhydroxyl compounds of high molecular weight, polyisocyanates, chain extenders, and, if desired, catalysts and additives, in which the polyhydroxyl compound is reacted with diisocyanate material in amounts to give an OH:NCO ratio of 1:1.10 to 1:2 and produce an adduct, and the adduct is subsequently reacted with symmetrical aromatic diisocyanate and a diol as chain extender (preferably a linear diol containing 2,4 or 6 carbon atoms) to obtain a crystalline or crystallizable diurethane or polyurethane of good heat resistance.

Abstract: Polymers reactive towards free amino groups, such as polyamides, polyureas, polyurethanes or polyesters, are provided with durable modified properties by being brought into contact with an additive polymeric material which (a) is compatible with the polymer being treated, (b) contains a plurality of oxyalkylene groups effective to impart to the modified polymer improved properties such as reduced static propensity, modified dyeability, or greater water absorbency; and (c) has one or more reactive sites, in the form of a pendant free primary amino group or potential primary amino group, blocked by the dehydration of an aldehyde or a ketone with the amine, which in either case affords the capability in proper circumstances of attaching the modifying polymeric material to the polymer being treated by a covalent chemical bond.

Abstract: An improvement in the recovery of mercury from aqueous streams is achieved by the use of polytetrafluoroethylene filters.

Abstract: The invention provides a method of use for a spotting-agent composition for use in laundering garments is provided which consists essentially of a solution of (1) about 10 weight percent or more of a nonionic surfactant produced by reacting a mixture of fatty alcohols containing 10 to 18 carbon atoms (with the proviso that the proportion of such alcohols which is attributable to alcohols containing 17 or more carbon atoms is limited to about 20 percent by weight) with mixed lower-alkylene oxides (ethylene oxide and propylene oxide) to such an extent as to have the mixed oxides comprise about 57 to 68 weight percent of the total fatty alcohol plus alkylene oxides used, with the proportion of ethylene oxide in the mixed oxides used being about 50 to 70%, in (2) an isoparaffinic solvent made of a mixture of isoparaffins containing about 11 to 14 carbon atoms.

Abstract: Membranes for use in chlor-alkali cells, made of a copolymer of tetrafluoroethylene and sulfonylfluoride perfluorovinyl ether, have their selectivity improved, with resulting substantial decrease in consumption of electric power per mole of sodium hydroxide produced, by being heat-treated at 100 to 275.degree. Centigrade for several hours to four minutes. The current efficiency is substantially increased, and the power consumption, per unit of sodium hydroxide produced, is usually decreased by about 10 percent or more.

Abstract: Nonionic surfactant compositions are made by reacting a 3 to 30-unit polyglycerol as hydrophile with a hydrophobic glycidyl ether in sufficient quantity to substitute 4 to 25% of the hydroxy groups of the polyglycerol. By using glycidyl ethers (which can be made conveniently by reaction of hydrophobic alcohol with epichlorohydrin) it becomes possible to avoid the expense of working with long-chain 1,2-epoxides. The surfactant compositions obtained have solubility and stability in a variety of concentrated ionic solutions, and especially in basic media.

Abstract: As a tall-oil-soap skimming aid, there is added to black liquor resulting from the pulping of coniferous trees a terpolymer of (a) an alpha-beta-unsaturated acid, (2) an alkylate of an alpha-beta-unsaturated acid, and (3) allyl alcohol. The acid contains 3 to 4 carbon atoms and comprises about 60 to about 88 percent by weight of the terpolymer. The alkylate comprises about 6 to 28 parts by weight of the terpolymer, being an ester of the abovementioned acids, the ester having an alkyl portion containing 1 to 18 carbon atoms. Allyl-alcohol units are present in the terpolymer to an extent of 4.5 to 20 weight percent. The terpolymer can be produced by free-radical polymerization in accordance with the customary procedures. With the use of such a copolymer, the proportion of tall oil recovered from black liquor is very substantially increased.

Abstract: A composition affording satisfactory performance in commercial glassware-cleaning equipment, operating with room-temperature water, is obtained with a composition containing not only a satisfactory proportion of caustic but also a very low-foaming nonionic surfactant and, as a solubilizer for such surfactant, a cycloaliphatic C.sub.21 dicarboxylic acid or one of its alkali-metal or ammonium salts.

Abstract: Highly branched polyether polyols of high molecular weight (such as over 12,000) are made by coupling an alkoxylated polyglycerol, by reaction of the sodium alcoholate of the oxyalkylated polyglycerol with a dibenzenesulfo or ditoluenesulfo ester of a diol containing 2 to 6 carbon atoms. Products obtained are viscous resinous products which are particularly suitable for use as hydrophilic water-swellable gels and other purposes.

Abstract: Polymers reactive towards free amino groups, such as polyamides, polyureas, polyurethanes or polyesters, are provided with durable modified properties by being brought into contact with an additive polymeric material which (a) is compatible with the polymer being treated, (b) contains a plurality of oxyalkylene groups effective to impart to the modified polymer improved properties such as reduced static propensity, modified dyeability, or greater water absorbency; and (c) has one or more reactive sites, in the form of a pendant free primary amino group or potential primary amino group, blocked by the dehydration of an aldehyde or a ketone with the amine, which in either case affords the capability in proper circumstances of attaching the modifying polymeric material to the polymer being treated by a covalent chemical bond.

Abstract: Polyether polyols may be synergistically stabilized against oxidation by incorporating therewith 4,4'-bis(alphadimethylbenzyl) diphenyl amine and a 2,6-di-t-butyl-4-(lower alkyl) phenol such as 2,6-di-t-butyl-4-methyl phenol or 2,6-di-t-butyl-4-butyl phenol. The stabilized polyols inhibit color formation when employed in the preparation of polyurethane foams.