Abstract: The invention relates to a method of preparing polyamides, in which, in a first step, the anionic polymerization of at least one lactam is carried out and then, in a second step, a heat treatment is carried out on the polymer obtained, which has a distribution of the molar masses measured by SEC having a shape close to a Gaussian curve with a high-mass tail, at a high enough temperature and for a long enough time so as to obtain a unimodal distribution of the molar masses.

Abstract: The invention relates to the use of polyamide moulding compounds, their alloys or blends, which contain at least one homopolyamide, which has been obtained from long-chained aliphatic monomer blocks with cycloaliphatic monomer blocks, in order to manufacture moulded members for optical or electro-optical applications.

Abstract: The present invention relates to the synthesis of new type of diamine monomer, 1,3-bis(4-amonophenoxy)naphthalene, and with such a compound to produce a series of aromatic polymers, including polyamide, polyimide, copoly(amide-imide)s, etc., such polymers having excellent resistance to heat and mechanical properties.

Abstract: A process for preparing a polyamide by reacting at least one aminonitrile with water comprises: (1) reacting at least one aminonitrile with water at a temperature from 100 to 360° C. and a pressure from 0.1 to 35×106 Pa to obtain a reaction mixture, (2) further reacting the reaction mixture at a temperature from 150 to 400° C. and a pressure which is lower than the pressure in step 1, the temperature and the pressure being selected so as to obtain a first gas phase and a first liquid or a first solid phase or a mixture of first solid and first liquid phase, and the first gas phase is separated from the first liquid or the first solid phase or from the mixture of first liquid and first solid phase, and (3) admixing the first liquid or the first solid phase or the mixture of first liquid and first solid phase with a gaseous or liquid phase comprising water at a temperature from 150 to 360° C. and a pressure from 0.1 to 30×106 Pa to obtain a product mixture.

Abstract: Substrates that are moisture-sensitive and/or corrosion-sensitive, such as electrical components found in fiber optic cables, copper wires, terminal blocks, connections and junctions, are protected from moisture and/or corrosion with a protectant composition that includes a polyamide gelling agent, a gelled solvent, and optionally a bleeding agent. The electrical components are typically contacted with the protective composition to protect the sensitive component from moisture and/or corrosion.

Abstract: A process for producing a polyamide from dicarboxylic acid monomer and diamine monomer comprises the steps of: (a) mixing molten dicarboxylic acid monomer and molten diamine monomer in equimolar amounts, thereby producing a molten reaction mixture; (b) flowing the reaction mixture through at least one unvented reaction vessel, the residence time of the reaction mixture in the at least one unvented reaction vessel being between about 0.01 minutes and about 30 minutes, thereby forming a first product stream that comprises polyamide and water of polymerization; and (c) flowing the first product stream through at least one vented vessel, whereby water of polymerization is removed, thereby forming a second product stream that comprises polyamide. The process can operate continuously, and there is no need to add water to the dicarboxylic acid, to the diamine, or to the reaction mixture.

Abstract: Colpolyamides resulting from the polycondensation of a mixture of (a) dodecanelactam (L12) or of 12-aminododecanoic acid (A12) and of (b) 11-aminoundecanoic acid (A11) are characterized in that the monomer L12 or A12 represents 1 to 15% or 85 to 99% by weight of the mixture, and the copolyamides have melting points (mp) as a function of the composition, the units originating from the monomer A12 and L12 being in a majority or minority respectively:(1) A12 or L12 is a majority: mp (.degree. C.).gtoreq.176-0.567.times.(% A11)(2) A12 or L12 is a majority: mp (.degree.).gtoreq.187-0.5.times.(% A12 or L12),the melting points being determined by taking the peaks of the exotherm signals obtained in differential thermal analysis with a rate of heating of 10.degree. C./minute for the second heating run. Such copolyamides have a property of resilience at low temperature and a property of improved suppleness, especially when plasticizer is added to them.

Abstract: An ester-terminated dimer acid-based polyamide may be blended with a solvent to form a gel. The solvent may be flammable, and a wick may be added to the resulting gel so as to form a candle. Depending on the composition, the candle may be formed into a free standing pillar, or may be better suited to being placed in a container. The solvent may be mineral oil. A solid coating may be placed around the candle, for advantages including to enhance the mechanical stability of the gelled body, and to eliminate the tendency of a gel to have an oily feel and to accept noticeable fingerprints. The solvent which, in combination with the ester-terminated dimer acid-based polymer forms a gel, may be or include a fragrance material, an insecticide or an insect repellent. A wick may or may not be present in this gel, but in any event, the composition provides for the release of the fragrance, insecticide or insect-repellent.

Abstract: A two-step process for the production of polyamides from .alpha.,.omega.-dinitriles and .alpha.,.omega.-diamines involving the catalytic hydrolysis of the .alpha.,.omega.-dinitrile by addition of water with simultaneous purging of the reactor (i.e., venting of ammonia and water vapor) in the first step followed by polymerization by addition of the .alpha.,.omega.-diamine to the hydrolysate in the second step. Such a process is particularly useful in the production of poly(hexamethylene adipamide), i.e., nylon 6,6, from adiponitrile and hexamethylene diamine using lower catalyst levels during hydrolysis and resulting in reduced levels of bis(hexamethylene)triamine, BHMT, in the polymer.

Abstract: A process for the hydrolysis of a dinitrile (e.g., adiponitrile) utilizing from 0.1 to 500 mmoles of catalyst (e.g., a mixture of phosphorous acid and calcium hypophosphite) per mole of the dinitrile and in the presence of from 0.01 to 0.5 moles of a dicarboxylic acid cocatalyst (e.g., adipic acid) followed by addition of a diamine (e.g., hexamethylenediamine) and heating to produce polymerization. Such a process is particularly useful in the production of nylon 6,6 having a low BHMT content and improved melt stability.

Abstract: A process for the hydrolysis of a dinitrile (e.g., adiponitrile) utilizing a dicarboxylic acid (e.g., adipic acid) as the sole catalyst followed by addition of a diamine (e.g., hexamethylenediamine) and heating to produce polymerization. Such a process is particularly usefull in the production of nylon 6,6 having a low BHMT content and improved melt stability.

Abstract: A method for the production and use of a catalytically-acting liquid system is offered, which has no or only a small proportion of free lactam, and which is of low viscosity and good storage stability and which directly initiates the anionic lactam polymerization.

Abstract: A low molecular weight, ester-terminated polyamide may be blended with a liquid hydrocarbon to form a transparent composition having gel consistency. The ester-terminated polyamide is prepared by reacting "x" equivalents of dicarboxylic acid wherein at least 50% of those equivalents are from polymerized fatty acid, "y" equivalents of diamine such as ethylene diamine, and "z" equivalents of monoalcohol having at least 4 carbon atoms. The stoichiometry of the reaction mixture is such that 0.9.ltoreq.{x/(y+z)}.ltoreq.1.1 and 0.1.ltoreq.{z/(y+z)}.ltoreq.0.7. The reactants are heated until they reach reaction equilibrium. The gel contains about 5-50% ester-terminated polyamide with the remainder preferably being pure hydrocarbon. The gels are useful in formulating personal care products and other articles wherein some degree of gel-like or self-supporting consistency is desired.

Abstract: Polyamides are built up from, as fundamental building blocks (a), lactams or aminocarboxylic acids or mixtures of these,as fundamental building blocks (b), from 1 to 50 .mu.mol of at least tribasic amines or carboxylic acids per gram of polyamide,as fundamental building blocks (c), dibasic carboxylic acids or amines andas fundamental building blocks (d), monobasic carboxylic acids or amines,where (c) and (d) are carboxylic acids if (b) are amines, and (c) and (d) are amines if (b) are carboxylic acids,the equivalents ratio of the functional groups of (b) to the functional groups of (c) and (d) together is from 60:40 to 40:60 andthe equivalents ratio of the functional groups of (c) to the functional groups of (d) is from 15:85 to 60:40.

Abstract: An uncoated lens, especially for use as the lens of a fog light or a headlight for an automobile, and having particularly good resistance against the environmental effects which are inherent in this environment, is formed of a colorless, transparent copolyamide having a glass transition temperature of at least a 170.degree. C., blended with a homopolyamide, and wherein the copolyamide is formed from at least one cycloaliphatic diamine with two cyclohexane rings, and at least one aromatic dicarboxylic acid which is predominantly isophthalic acid. The copolyamide may optionally contain up to 20 mol % of a further polyamide forming monomer of at least one lactam or an omega-aminocarboxylic acid. The homopolyamide is preferably one of PA6, PA11, PA12, PA66, PA69, PA610 or PA612. The cycloaliphatic diamine of the copolyamide is preferably bis(3-methyl-4-aminocyclohexyl)-methane.

Abstract: Pyrrolidonyl-containing polyesters and polyamides I to III ##STR1## where R, X, A and Z are defined herein, are suitable as film formers and conditioners in hair-cosmetic formulations, for stabilizing hydrogen-peroxide in aqueous solution, for complexing iodine, as tablet binders and as a constituent of film coatings in pharmaceutical preparations, for enzyme and bleach stabilization in detergent formulations, as an auxiliary in the production and finishing of textiles, as a solubilizer and protective colloid in the preparation and stabilization of polymer dispersions, and as an adhesive raw material.

Abstract: The semiaromatic polyamide of the invention comprises 40 to 90% by mol of (A) recurring units derived from terephthalic acid and an aliphatic diamine of 4 to 12 carbon atoms, 0 to 50% by mol of (B) recurring units derived from isophthalic acid and an aliphatic diamine of 4 to 12 carbon atoms, 0 to 60% by mol of (C) recurring units derived from an aliphatic dicarboxylic acid of 4 to 18 carbon atoms and an aliphatic diamine of 4 to 12 carbon atoms and 0 to 50% by mol of (D) recurring units derived from a lactam or an aminocarboxylic acid of 6 to 20 carbon atoms, and has a content of boiling water-soluble components (MO components) of not more than 0.25% by weight. The semiaromatic polyamide has a low content of the MO components, so that mold contamination hardly brought about in the molding process, and also molded articles of good heat resistance can be produced.

Abstract: A process for producing a polyimide composition by reacting at least one polyamic acid or at least one polyamic ester or a mixture of at least one polyamic acid and at least one polyamic ester with a selected phosphoramide in the presence of at least one base catalyst to from a polyimide composition.

Abstract: A process for making polyimide composition comprising reacting at least one diamine, at least one tetracarboxylic diacid diester, selected phosphoramide and at least one base catalyst to form at least one polyimide compound, said reaction carried out at a temperature from about 20.degree. C. to about 60.degree. C. and wherein the molar ratio of diamine:tetracarboxylic diacid diester:phosphoramide:base catalyst is in the range of 0.8-1.2:1:2.5-4.0:2.5-4.0.

Abstract: A low molecular weight, ester-terminated polyamide may be blended with a liquid hydrocarbon to form a transparent composition having gel consistency. The ester-terminated polyamide is prepared by reacting "x" equivalents of dicarboxylic acid wherein at least 50% of those equivalents are from polymerized fatty acid, "y" equivalents of diamine such as ethylene diamine, and "z" equivalents of monoalcohol having at least 4 carbon atoms. The stoichiometry of the reaction mixture is such that 0.9.ltoreq.{x/(y+z)}.ltoreq.1.1 and 0.1.ltoreq.{z/(y+z)}.ltoreq.0.7. The reactants are heated until they reach reaction equilibrium. The gel contains about 5-50% ester-terminated polyamide, with the remainder preferably being pure hydrocarbon. The gels are useful in formulating personal care products and other articles wherein some degree of gel-like or self-supporting consistency is desired.

Abstract: Disclosed are a method for producing a polyamide resin which comprises the steps of extracting with water a polyamide resin obtained by polymerizing caprolactam in the presence of water; condensing the extracted aqueous solution containing unreacted caprolactam and its low polymerized materials; and polymerizing the condensate by adding an additional amount of caprolactam, the improvement wherein(a) among the low polymerized materials of caprolactam, a cyclic dimer is supplied to a polymerization reactor after subjecting it to ring-opening reaction to give a chain structure material in an amount of 15% by weight or more based on the total amount of the cyclic dimer, or(a') a condensate obtained by condensing said aqueous solution until reaching a water partial pressure of 10 kg/cm.sup.2 G or more and a temperature of 230.degree. C.

Abstract: There are proposed a method and a device for manufacturing polyamides, in which polyamide granulate manufactured by polycondensation in the molten mass is after-condensed in the solid phase, being heated. The polyamide granulate is heated in one step to a first temperature of between 70.degree. C. and 150.degree. C., and held for a predetermined period of time at this temperature, and then, in a second step, is heated to a second higher temperature, however lying beneath the melting point, and is after-condensed at this temperature, until the desired average degree of polycondensation is achieved.

Abstract: A process for the activated anionic lactam polymerization is proposed, wherein a liquid system is employed, which simultaneously contains activator and anionic catalyst for the polymerization of the lactam.

Abstract: A continuous process for activated anionic lactam polymerization is proposed, wherein a liquid system is employed, which simultaneously contains activator and anionic catalyst for the polymerization of lactam.

Abstract: This invention relates to a novel ternary polyamide for the production of monofilaments, films and injection moulded articles.

Abstract: Partly aromatic semicrystalline thermoplastic polyamide molding compositions containA) from 40 to 100% by weight of a copolyamide composed ofa.sub.1) from 30 to 44 mol % of units which are derived from terephthalic acid,a.sub.2) from 6 to 20 mol % of units which are derived from isophthalic acid,a.sub.3) from 43 to 49.5 mol % of units which are derived from hexamethylenediamine anda.sub.4) from 0.5 to 7 mol % of units which are derived from aliphatic cyclic diamines of 6 to 30 carbon atoms,the molar percentages of components a.sub.1) to a.sub.4) together giving 100%, andB) from 0 to 50% by weight of a fibrous or particulate filler,C) from 0 to 30% by weight of an elastomeric polymer andD) from 0 to 30% by weight of conventional additives and processing assistants,the percentages by weight of components A) to D) together giving 100%.

Abstract: Certain polyamide resin compositions make it possible to shorten the injection molding processing cycle for polyamide resins. The polyamide resin compositions are obtained by adding an external lubricant to polyamide resin granules composed of from 55 to 85% by weight of polyamide resin, 10 to 40% by weight of filler, and 0.3 to 2.0% by weight of at least one type of higher fatty acid ester type internal lubricant selected from among esters of higher alcohols and higher fatty acids and higher fatty acid partial esters of polyhydric alcohol compounds.

Abstract: Colorless, transparent copolyamides, made up of monomers based on cycloaliphatic diamines and aromatic dicarboxylic acids and a maximum of 20 mol % of further polyamide-forming aliphatic monomers, which have glass transition temperatures of at least 175.degree. C., their blends and alloys, along with the molded articles that can be produced from them and a process for their preparation are proposed.

Abstract: The invention provides a continuous process for the preparation of polyamides, equipment in which the polymerization process can be conducted, and process control methods for said polymerization process.

Abstract: The invention relates to thermoplastically processible aliphatic polyesteramides which are biodegradable (compostable).

Abstract: Process for synthesis of spinnable polyamide from .alpha., .omega.-alkyldinitriles and .alpha., .omega.-alkyldiamines and excess water, where a) the aqueous solution of the dinitrile is mixed with a catalytic amount of at least one oxygen-containing acid of phosphorus and/or a water-soluble salt of calcium, zinc, cadmium or manganese in the absence of the diamine, and the pH of this solution is adjusted to an initial value in the range of 2.0 to 4.0 before hydrolysis by adding a saturated aliphatic or aromatic dicarboxylic acid and the dinitrile is and the amide-containing precursors derived therefrom are hydrolyzed to dicarboxylic acid at an elevated temperature under autogenous pressure, whereby the hydrolysis is controlled by conductometric determination of the hydrolysate, and b) at least an equimolar amount of diamine is added to the solution from step a) and the mixture is subjected to polycondensation to form polyamide [nylon].

Abstract: The invention relates to a process for the production of high molecular weight polyamide 6 (polycaprolactam).

Abstract: A thermoplastic molding material consists of from 5 to 95% by weight of a polyaryl ether A, from 5 to 95% by weight of a partly aromatic copolyamide B and, if required, not more than 40% by weight of a fibrous or particulate filler C or a mixture thereof, the percentages being based on the sum of A to C.

Abstract: Novel polyesters prepared from a diol, a dicarboxylic acid or ester forming reactive derivative thereof and an aromatic amino acid, ester or alcohol are disclosed.

Abstract: A new class of thermotropic liquid crystalline polymers comprises monomers units I, II, III, and IV, where ##STR1## Ar.sup.1, Ar.sup.2 and Ar.sup.3 are each independently selected from the group consisting of 1,3-phenylene, 1,4-phenylene, 2,6-naphthylene, 2,7-naphthylene, 4,4'-biphenylene, bis-aryl moieties having the formula ##STR2## and mixtures thereof. In the bis-aryl moieties, each X can be S, O, CO, SO, SO.sub.2, C(CH.sub.3).sub.2 or C(CF.sub.3).sub.2.

Abstract: A process for the manufacture of a partially aromatic polyamide is disclosed. The process comprises the polymerization stages of, in sequence, feeding to a reactor a slurry of at least one aromatic dicarboxylic acid and at least one aliphatic diamine, then with the incremental addition of water and in the presence of 0.05 to 2% by weight of a monocarboxylic acid, heating the slurry to a temperature of at least 270.degree. C. while maintaining a pressure of at least 1.2 MPa. The preferred dicarboxylic acid is 2,6 naphthalene dicarboxylic acid. The polyamides may be used in the manufacture of products using melt processing techniques.

Abstract: This invention relates to a novel fluorine-containing polyimide or polyimide copolymer being colorless and having transparency and very low dielectric characteristics, and has a novel aromatic diamino compound used for the polyimide, a preparation process thereof, a polyimide-based resin composition comprising the polyimide or polyimide copolymer and a fibrous reinforcement, a process for preparing the resin composition, an injection molded article of the resin composition.

Abstract: The use of copolyamides as melt adhesive for heat sealing is disclosed. At least three monomer components are copolymerized in the copolyamide. These monomer components are selected from the following group: an equimolar mixture of adipic acid and hexamethylenediamine (6,6 salt), lauric acid lactam, 11-aminoundecanoic acid, an equimolar mixture of azelaic acid and hexamethylenediamine (6,9 salt), an equimolar mixture of sebacic acid and hexamethylenediamine (6,10 salt) and an equimolar mixture of dodecane dicarboxylic acid and hexamethylenediamine (6,12 salt), the melting point of the copolyamide being lower than 140.degree. C. and at least 10% by weight of lauric acid lactam and/or 11-aminoundecanoic acid being copolymerized.

Abstract: Aramids which after drawing have high tensile strengths and tensile moduli are made from units derived from selected 2,2'-disubstituted-4,4'-diaminobiphenyls, p-phenylenediamine, oxydianiline and terephthalic acid. Also disclosed is a process for drawing such aramids at least 1.5%, which results in the drawn aramid having significant crystallinity and higher tensile strength. The aramids are useful for ropes and composites.

Abstract: This invention provides hydrolytically labile polyamide compositions and articles containing an ester derived moiety in the polymer backbone which will degrade after exposure to water over long periods of time.

Abstract: The new process for the preparation of polycondensates from polyamidoamines, epichlorohydrin and if appropriate polyamines, unreacted epichlorohydrin being removed by passing an inert gas through the reaction mixture, produces salt-free reaction products which have very low organic chlorine contents and at the same time very low values for dichloropropanol, chloropropanediol and epichlorohydrin, and are excellently suitable as auxiliaries for paper and textiles.

Abstract: Discontinuous catalytic process for the production of polyamide-6,6 by heating an aqueous AH-salt solution containing HPO.sub.3.sup.2- -ions, precondensing the solution with evaporation of water at 7 to 10 bar pressure and polycondensing in the melt phase, whereby the heating rate above 175.degree. C. of the AH-salt solution is at least in the range of 0.5.degree. to 3.0.degree. C./minute, the rate of evaporation of water is at least 2%/minute (based on the quantity of water in the AH salt solution). The total residence time for a polymer having a relative viscosity of 2.2 to 3.0 for heating from 175.degree. C., precondensation and melt phase polycondensation, is not more than 90 minutes.

Abstract: New synthesis and analysis procedures for novel crosslinked polyamines and ampholytes. Polyamines are crosslinked with tartaric acid ester, malonic acid ester, or polycarboxylic acid esters of the citric acid cycle. The resulting crosslinked polyamine may further react with other compounds such as an .alpha.,.beta.-unsaturated or .alpha.-halo unsaturated carboxylic acids to prepare new ampholyte mixtures. The resulting novel ampholytes exhibit greater heterogeneity and complexity than presently prepared ampholytes, and can be used in analytical and preparative isoelectric focusing processes.Novel ampholyte analysis process entails analyzing chemical compounds, usually ampholytes, used in isoelectric focusing processes. The ampholyte is isoelectrically focused on an immobilized pH gradient, and then immersed in a picric acid solution to cause precipitation and visualization of amphoteric species.

Abstract: Polyamides and polyamide fibers having a major proportion of hexamethyleneadipamide units and minor proportions of at least two other amide units, one of those other amide units being those of 2-methylpentamethylenediamine are disclosed.

Abstract: The present invention relates to new polyamides comprising, on a mass basis:(a) 45 to 75% of an x,T unit, x being between 4 and 12 inclusive, the x,T unit being the condensation product of a diamine having x carbon atoms and of terephthalic acid, and(b) 55 to 25% of an aliphatic unit -HN-(CH.sub.2).sub.n -CO, n being between 6 and 14 inclusive. and the terpolyamides obtained by including a monomeric unit (c) such as the unit 6 or 6,I as a replacement for part of the aliphatic unit (b).The polyamide compositions thus obtained exhibit a Tg lower than 130.degree. C., a Tm higher than 230.degree. C. and a good crystallizability.

Abstract: Transparent polyamide compositions having high resistance to chemical agents, as well as the process for their preparation and the articles obtained from said compositions. The present polyamide compositions contain from 1 to 99% by weight, preferably 40 to 90% by weight, of a first polyamide consisting of aliphatic units containing at least 7 carbon atoms, isophthalic and terephthalic diacids, the latter being predominant, and cycloaliphatic diamine units, and from 99 to 1% by weight, preferably 60 to 10%, of a semi-crystalline polyamide consisting of at least 35%, preferably 50%, by weight of an aliphatic unit containing at least 7 carbon atoms.

Abstract: Nylon carpet or textile yarn may be produced at an increased rate of throughput/spinneret hole by incorporating into nylon 6.6 polymer a secondary component which improves processability and lustre by suppressing spherulitic growth. The secondary component may be a co-monomer (e.g. hexamethylene diamine/isophthalic acid) which is incorporated during polymerisation to form a random co-polymer, a polymer (e.g. nylon 6) which is molecularly dispersed in the nylon 6.6 polymer without significant copolymerisation occurring or a metal salt (e.g. lithium chloride).

Abstract: Thermoplastic polymeric composition which feature good physical properties which are relatively insensitive to humidity and further exhibits good barrier properties of the composition comprise:(A) a first conventional polyamide, and(B) an amorphous copolyamide which is polymerized from(B.sub.1) a polyamide forming monomer selected from the group consisting of lactams, aminoalkanoic acids and mixture thereof wherein the monomer is present in a molar proportion of between about 0 and 50%,(B.sub.2) a diamine selected from the group consisting of aralkylene diamines, cycloalkylene diamines and mixtures thereof, the diamine being present in a molar proportion of between about 25 and 60%,(B.sub.

Abstract: Novel polyesters prepared from a diol, a dicarboxylic acid or ester forming reactive derivative thereof and an aromatic amino acid, ester or alcohol are disclosed.

Abstract: A deformable surgical repair device is manufactured from a block or graft copolymer. The copolymer comprises a plurality of first linkages selected from the group consisting of glycolic acid ester and lactic acid ester linkages, and mixtures thereof, and a plurality of second linkages selected from the group consisting of 1,3-dioxan-2-one; 1,4-dioxan-2-one and .epsilon.-caprolactone linkages. The plurality of first linkages comprises at least about 50 up to about 90 mole percent of the copolymer. In an alternative Claim, the deformable surgical repair device is manufactured from a blend of a first and a second absorbable polymer. The first absorbable polymer comprises a plurality of linkages selected from the group consisting of glycolic acid ester and lactic acid ester linkages, and mixtures thereof. The second absorbable polymer comprises a plurality of linkages selected from the group consisting of 1,3-dioxan-2-one; 1,4-dioxan-2-one and .epsilon.-caprolactone linkages.