Abstract: In production of cyclohexanone by hydrogenating phenol in the presence of a hydrogenation catalyst, improved catalyst life and improved hydrogenation rate are obtained if ketone impurities, particularly hydroxyacetone, are removed from the phenol prior to the hydrogenation. The present invention provides an improved method for reducing the ketone impurities in the phenol by contacting the phenol with a polyethylenimine and distilling the mixture formed to separate the phenol. The invention is particularly useful in production of cyclohexanone from phenol obtained by decomposition of cumene hydroperoxide.

Abstract: The esterification of an aromatic dicarboxylic acid with an alkylene glycol containing 2 to 10 carbon atoms is described under conditions of direct esterification wherein the resultant polyester has low ether content. The dicarboxylic acid is esterified with the alkylene glycol in the presence of a compound of the formula ##STR1## wherein M is H, an alkali metal selected from the group consisting of lithium, sodium and potassium or an alkaline earth metal selected from the group calcium and magnesium.

Abstract: It has been suggested that a high strength polycaproamide fiber having excess number of carboxyl end groups over amino end groups can be produced by melt spinning a polymer prepared by polymerizing e-caprolactam and reacting the polymer with a dibasic carboxylic acid containing at least six carbon atoms. However, with incorporation of this dicarboxylic acid reactant in continuous operation, serious problems have been encountered in melt-spinning of the polymer due to the frequent occurrence of "nubs" or enlarged places in the extruded polyamide filament. It has now been found that the occurrence of said nubs in the fiber can be greatly reduced by utilizing certain cyclic tetracarboxylic acid dianhydrides and reacting the dianhydride at the end of the polymerization. Moreover, dyeing properties of the fiber may be more readily controlled.

Abstract: In the production of polyester fibers in a melt-spinning process, the transfer system between the melt source and the spinning position has a special importance due to the thermal degradation of the polyester. The present invention provides an improved transfer process which ensures relatively low thermal degradation of the molten polymer. The process is characterized by employment of two or more indexes whereby transfer elements and polymer flows in the transfer system may be correlated for minimum degradation of the polymer. The invention is of particular importance in a continuous process involving continuous polyester polycondensation coupled with continuous melt-spinning.

Abstract: In a continuous process for production of polyester polymers, polymer additives are added to the process stream at a point where the polymer is molten by injecting a stable liquid dispersion formed from a liquid polyisobutene and the requisite polymer additives. The process is particularly useful in production of thermally stabilized polyesters wherein a stabilizing amount of a copper complex compound is incorporated therein.

Abstract: A low shrinkage polyester fiber is produced by melt-spinning a polyester polymer under conditions of substantially simultaneous spinning, drawing, and heat treating, using carefully controlled conditions whereby the fiber has uniform properties of breaking strength in grams per denier of at least 7.0, elongation at break in percent of 18 to 30, and a residual thermal shrinkage measured in an oven at 350.degree. F. for one minute of lower than 3 percent. The low shrinkage polyester fibers are particularly useful in the preparation of reinforced elastomeric structures.

Abstract: A flame-retardant polyamide fiber is prepared and made into a flame-retardant carpet. The polyamide fiber has incorporated therein from 1 to 15 percent by weight of zinc borate and from 1 to 15 percent of an organic halide which is substantially non-reactive with the polyamide except at temperatures above 300.degree. C. The flame-retardant fiber shows improved luster and improved colorfastness to light when dyed.

Abstract: Combinations of certain hydroxycarboxylic acids with certain metal oxides and hydroxides provide unexpectedly enhanced flame retardancy to carpets, said flame retardancy being durable to usual carpet cleaning procedures.

Abstract: An improved polyamide characterized by resistance to thermal-oxidative degradation consisting essentially of a polyamide having a stabilizing amount of copper II dichloro bis (pyridine) or copper II dichloro bis (quinoline) incorporated therein. In a continuous process, the stabilizing compound is preferably added as a dispersion in an inert carrier liquid.CROSS-REFERENCE TO RELATED APPLICATIONSThis application is related to U.S. application Ser. No. 752,483 filed Dec. 20, 1976.BACKGROUND OF THE INVENTIONThis invention relates to improved polyamides and to methods for their preparation. More particularly, the invention relates to improvement in the preparation of fibers, filaments and yarns from polyamides modified for enhanced resistance to thermal-oxidative degradation.The polyamide synthetic resins have many valuable properties that have resulted in their well known wide-spread use in industry and in the arts.

Abstract: It has been suggested that a high strength polycaproamide fiber having excess number of carboxyl end groups over amino end groups can be produced by melt spinning a polymer prepared by polymerizing e-caprolactam and reacting the polymer with a dibasic carboxylic acid containing at least six carbon atoms. However, with incorporation of this dicarboxylic acid reactant in continuous operation, serious problems have been encountered in melt-spinning of the polymer due to the frequent occurrence of "nubs" or enlarged places in the extruded polyamide filament. It has now been found that the occurrence of said nubs in the fiber can be greatly reduced by utilizing certain cyclic tetracarboxylic acid dianhydrides and reacting the dianhydride at the end of the polymerization. Moreover, dyeing properties of the fiber may be more readily controlled.

Abstract: In a process for producing polyethylene terephthalate yarn, particularly for tire cords, wherein a liquid finish is applied to the yarn, said process involving spinning and drawing steps, the improvement comprising: (a) first applying to the yarn prior to said drawing step a liquid finish composition consisting essentially of a polyalkylene glycol compound which is a mixed polyoxyethylated-polyoxypropylated monoether prepared in accordance with the equation: ##STR1## where R is an alkyl group having 1 to 8 carbon atoms, x and y are the number of moles of propylene oxide and ethylene oxide respectively and wherein ethylene oxide comprises 40 to 60 percent by weight of the combined total of ethylene oxide and propylene oxide and x+y has a value to produce a molecular weight of from 300 to 1,000; and then (b) applying to said yarn after said drawing step a liquid finish composition consisting essentially of about 70 to 95 parts by weight of said mixed polyoxyethylated-polyoxypropylated monoether, about 5 to 30 p

Abstract: It has been suggested that antistatic properties of fibers of polyamide could be improved by uniformly dispersing in the polyamide between about 1 percent and about 12 percent by weight of a predominantly branched, chain-extended propylene oxide-ethylene oxide copolymer based on a diamine. However, with incorporation of this antistatic additive in the polyamide, serious problems have been encountered in melt-spinning due to the frequent occurrence of "nubs" or enlarged places in the extruded polyamide filament. It has now been found that the occurrence of said nubs in the antistatic polyamide fiber can be greatly reduced by dispersing in the polymer about 0.5 to 12% by weight, based on the weight of the antistatic agent, of a phenol compound represented by the formula: ##STR1## where n is 2 to 6.

Abstract: An improved process and apparatus for production of synthetic multifilamentary yarns having uniform quality. The method comprises extruding a molten synthetic polymer downwardly through a spinneret, advancing the extruded filaments downwardly through a substantially stationary column of heated air, and subsequently advancing the filaments downwardly through a quenching zone wherein they are in contact with cooling air introduced into the path of the filaments under controlled conditions of air velocity and direction of flow.

Abstract: Ammonium nitrite is commercially produced by contacting a gaseous stream containing nitric oxide, nitrogen dioxide and oxygen with an aqueous solution containing a basically reacting ammonium compound in an absorption system. However, at normal production rates, serious problems have been encountered because of the emission of unreacted nitric oxide which causes pollution of the atmosphere. It has now been found that by adding controlled supplemental quantities of nitrogen dioxide to the absorption system, nitrogen oxide emission is substantially reduced.

Abstract: It has been suggested that certain polyglycol ethers, in particular mixed polyoxyethylated-polyoxypropylated monoethers, are useful as spin finishes in the production of polyester tire yarns. Polyglycol ethers having a relatively low molecular weight of about 300 to 1,000 make the best lubricants; however, their effectiveness is significantly diminished by volatilization loss during high temperature processing of the tire yarn. It has now been found that said volatilization loss is greatly decreased by including in the finish a small percentage of certain antioxidant compounds. The particular antioxidant compound used has been found to be very critical.

Abstract: A process for treating an adipic acid bleed stream obtained in the manufacture of adipic acid, said adipic acid bleed stream consisting mainly of nitric, adipic, glutaric, and succinic acids and a catalyst; the process comprising maintaining said adipic acid bleed stream in aqueous solution, and stripping nitric acid from said aqueous solution with steam at a temperature of about 100.degree.-110.degree. C. while maintaining in said aqueous solution a water to nitric acid weight ratio of at least 6, to remove substantially all of the nitric acid therefrom, thereby forming an aqueous nitric acid free mixture of said dibasic acids and said catalyst which can be safely dehydrated and distilled to produce useful chemicals.

Abstract: A flame-retardant pile carpet having a relatively pliable primary backing and a tufted surface, said surface being comprised of fibers selected from the group consisting of polyester and polyamide fibers having incorporated therein from 0.05 to 15 percent by weight of a compound selected from the group consisting of antimony oxide and zinc borate, said fibers being bonded to said backing with a bonding substance comprising a latex material and a hydrate material, said latex material being selected from the group consisting of polymers and copolymers of vinyl chloride and vinylidene chloride, and said hydrate material being selected from the group consisting of aluminum hydroxide and hydrated aluminum oxide, the ratio by weight of said latex material to said hydrate material being within the range 1:2 to 1:4.5.

Abstract: A method and apparatus for off-line testing and correcting the metering accuracy of a split multihole spinneret fed by a single metered stream by determining end to end variations in flow rate and by reworking a number of holes in the lower flow rate side of the split spinneret, calculated by multiplying the average test percent bias of the split spinneret by a predetermined constant, so as to bring end to end variations in flow rate to within a required accuracy.

Abstract: This invention relates to a yarn finishing composition and more specifically to a spin finish for multifilament yarns used in food packaging. The preferred finishing composition comprises butyl stearate, sorbitan monooleate and polyoxyethylene (20) sorbitan monooleate.

Abstract: This invention relates to a process for the production of cyclohexanone oxime by reacting cyclohexanone with excess aqueous hydroxylamine in the presence of excess ammonia. More specifically, the invention relates to improving yields of the oxime while reducing undesirable by-product formation by use of two or more stages of reaction with correlated adjustment of reaction conditions in each stage. The invention also involves improved recovery of the unreacted hydroxylamine reactant for recycle in the process.