Abstract: A copolyamide with an improved modulus of elasticity for the melt-spinning of filaments consists of at least 75 wt. % of a linear polyamide base polymer with a melting point of 150.degree.-320.degree. C. and at least 0.5 wt. % of a block comonomer which is incorporated into the base polymer and has a glass transition temperature (T.sub.g) between 130.degree. and 330.degree. C. and a degree of polymerization (DP) of <100. The filaments produced from the modified copolymer with an initial modulus of 500 to 1500 cN/tex are suitable for use in the production of technical fabrics.

Abstract: Semi-crystalline, semi-aromatic copolyamides derived from terephthalic acid and mixtures comprising an alkylpentamethylene diamine and hexamethylenediamine by a process including thermal polycondensation in a closed system of the autoclave type.

Abstract: The present invention relates to semi-crystalline, semi-aromatic copolyamides, derived from terephthalic acid and mixtures comprising an alkylpentamethylenediamine and hexamethylenediamine.

Abstract: Homogeneous copolyamides having high melting points and good flexibility, well adapted for the production of textile materials and plastic shaped articles, are prepared by prepolymerizing lower dicarboxylic acid(s) with an excess of hexamethylenediamine in the presence of a catalytically effective amount of a strong inorganic or organic oxyacid, or alkali or alkaline earth metal salt thereof, and thence polycondensing the resulting prepolymer with a fatty acid dimer.

Abstract: Amorphous (co)polyamides are polycondensed from aromatic dicarboxylic acid(s), e.g., isophthalic acid and/or terephthalic acid, and from aliphatic diamine(s), e.g., hexamethylenediamine, by preparing two unbalanced prepolymers of low viscosity, one containing excess COOH endgroups and the other containing excess NH.sub.2 endgroups, and then, in a second stage, the two unbalanced prepolymers are mixed in given proportions and their postcondensation is carried out in the molten state in a vented extruder including one or more screws; the amorphous (co)polyamides thus prepared are perfectly transparent and can be easily injection molded into useful shaped articles endowed with good properties, especially in respect of multiaxial impact.

Abstract: Homogeneous copolyamides having high melting points and good flexibility, well adapted for the production of textile materials and plastic shaped articles, are prepared by prepolymerizing lower dicarboxylic acid(s) with an excess of hexamethylenediamine in the presence of a catalytically effective amount of a strong inorganic or organic oxyacid, or alkali or alkaline earth metal salt thereof, and thence polycondensing the resulting prepolymer with a fatty acid dimer.

Abstract: Novel, homogeneous and flexible block copolyetheramides, having a melting point of at least 150.degree. C., a glass transition temperature not exceeding -5.degree. C. and a melt viscosity of at least 100 poises, are preferably prepared by prepolymerizing a mixture of a salt of a short-chain aliphatic dicarboxylic acid and a short-chain aliphatic diamine with a fatty acid(s) dimer or amino derivative thereof, and then polycondensing the prepolymer in the presence of a strong organic or inorganic oxyacid, with a polyoxyalkylenediamine or a polyoxyalkylenedicarboxylic acid having a number-average molecular weight ranging from 300 to 1200.

Abstract: Homogeneous, flexible block copolyetheramides having a melting/softening point of at least 170.degree. C., a glass transition temperature, measured at ZHE, of at most -5.degree. C.

Abstract: Homogeneous, high melting, flexible copolyamides, adopted as molding compositions and for textile applications, are conveniently prepared by (a) prepolymerizing either (i) mixture of adipic acid and hexamethylenediamine, or admixture thereof with at least one other short-chain dicarboxylic acid, or (ii) mixture of (1) a salt of adipic acid, or salt of admixture of adipic acid with at least one other short-chain dicarboxylic acid, and hexamethylenediamine, together with (2) free hexamethylenediamine, said prepolymerization (a) being carried out in the presence of a catalytically effective amount of a strong inorganic oxyacid, or strong organic oxyacid other than a carboxylic acid, or alkali or alkaline earth metal thereof, said resulting prepolymer having amino end groups, and thence (b) polycondensing said prepolymer with a fatty acid dimer.

Abstract: Novel block copolyetheramides which are homogeneous and flexible at low temperatures and have melting or softening points of at least 170.degree. C., glass transition temperatures of at most -5.degree. C. and viscosities in the molten state of at least 500 poises, are facilely prepared by copolymerizing (I) admixture of a lactam having from 4 to 12 carbon atoms with a solution of a salt of a fatty acid dimer and a polyoxyalkylenediamine in a solvent medium comprising (i) a mixture of water and an aliphatic alcohol having less than 5 carbon atoms, (ii) a water/alcohol/lactam mixture, (iii) a lactam in molten state or (iv) a water/lactam mixture wherein the lactam is water soluble, the stoichiometry of said salt being adjusted such that the pH thereof is within .+-.0.05 pH units of its equivalence point and (II) a minor amount of a strong inorganic oxyacid or a strong organic oxyacid other than a carboxylic acid.

Abstract: Flexible, homogeneous and transparent copolyamides comprise the polycondensation products of adipic acid, fatty acid dimer and hexamethylenediamine, the molar ratio of weight adipic acid to weight of total acid in each ranging from about 0.5 to 0.99, and that point obtained by plotting, along the abscissa, such molar fraction of adipic acid versus, along the ordinate, any individual copolyamide melting point, falling within that area A B C D outlined on the attached Figure of Drawing. The subject copolyamides are prepared either by polycondensing a homogenized prepolymer thereof, or by directly copolycondensing a homogeneous, inert solvent solution of monomers. The homogeneous and transparent copolyamides exhibit improved flexibility and high tenacity coupled with good resistance to hydrolysis and good heat resistance, with the copolyamides being useful for providing shaped articles such as moldings, films or filaments of marked uniformity via injection molding, extrusion or spinning.

Abstract: Provided are heat-stable polyphase polyamido compositions having improved mechanical properties which comprise (i) from 50 to 99% by weight of a nylon polyamide resin matrix and (ii) from 1 to 50% by weight of a particulate disperse phase comprising a polyamide incompatible with the polyamide resin matrix, and methods for the preparation thereof. Shaped articles comprising said compositions exhibit improved physical properties, particularly with regard to impact strength.

Abstract: Flexible, homogeneous and transparent copolyamides comprise the polycondensation products of adipic acid, fatty acid dimer and hexamethylenediamine, the molar ratio of weight adipic acid to weight of total acid in each ranging from about 0.5 to 0.99, and that point obtained by plotting, along the abscissa, such molar fraction of adipic acid versus, along the ordinate, any individual copolyamide melting point, falling within that area A B C D outlined on the attached FIGURE of Drawing. The subject copolyamides are prepared either by polycondensing a homogenized prepolymer thereof, or by directly copolycondensing a homogeneous, inert solvent solution of monomers. The homogeneous and transparent copolyamides exhibit improved flexibility and high tenacity coupled with good resistance to hydrolysis and good heat resistance, with the copolyamides being useful for providing shaped articles such as moldings, films or filaments of marked uniformity via injection molding, extrusion or spinning.

Abstract: Heat-stable polyphase polyamido compositions having improved mechanical properties are comprised of (i) from 55 to 99% by weight of a nylon polyamide resin matrix, said polyamide resin having a number-average molecular weight of at least 5,000, and (ii) from 1 to 45% by weight of a particulate disperse phase, said particulates having a particle size ranging from 0.01 to 10.mu., and said disperse phase comprising a polyesteramide having a content in amide groups of less than 40% of the amide groups comprising said polyamide matrix resin and a glass transition temperature of less than 5.degree. C.

Abstract: Random or regularly recurring block polyesteramides having glass transition temperatures at least as low as -30.degree. C. are prepared from (i) essentially difunctional monomers comprising at least one carboxylic acid function, or ester/amide-forming derivative thereof, at least 1 mol % of which comprising dicarboxylic acids or such derivatives thereof and having from 20 to 60 carbon atoms, with the amount of monofunctional carboxylic acids comprising said carboxyl monomers being less than about 1% by weight and the amount of carboxylic acids having in excess of two functional groups being less than about 5% by weight, and (ii) a member selected from the group consisting of dihydroxyl and diamino comonomers therefor, or aminoalcohol comonomers, or mixtures of diamino and aminoalcohol comonomers.

Abstract: Implantable surgical articles are provided which are at least partially bioresorbable and which consist at least partially of a copolyester of succinic acid and oxalic acid possessing receiving units of the general formulae: ##STR1## in which each R radical in the chain, which may be identical or different, represents a linear or branched alkylene radical possessing 2 to 6 carbon atoms, at least 2 of which carbon atoms form part of the polymer chain, a cyclo-alkylene radical possessing 5 to 8 carbon atoms, or a radical of the general formula: ##STR2## in which each of R.sub.1 and R.sub.2, which may be identical or different, represents a methylene or ethylene radical. They are particularly suitable as sutures.