Abstract: The present invention is a non-porous, breathable membrane of at least polyamide-4,6, with an elongation at rupture of about 250 to about 500% in the longitudinal direction and about 200 to about 500% in the transverse direction. The membrane has a higher heat resistance than a non-porous, breathable membrane made from polyether ester and, if it also contains an antioxidant, passes the oven/watertightness test. If the membrane is produced from a mixture of polyamide-4,6 and about 10 to about 30% by weight polyether amide, the membrane exhibits a surprisingly increased water-vapor permeability. The membrane is usable in the manufacture of thermally protective clothing.

Abstract: A process for continuous production of copolyamides based on a lactam (I), a diamine (II) and a dicarboxylic acid (III) comprises reacting a mixture (IV) comprising a diamine (II), a dicarboxylic acid (III) and water in a first reaction zone at a pressure in the range from 1.3*105 to 2.5*105 Pa in the entry zone of the reaction zone and at a temperature above the melting point of polymer (V) to a conversion, based on the molar amounts of diamine (II) and dicarboxylic acid (III), of at least 80% to form a polymer (V), reacting a mixture (VI) comprising lactam (I) and water in a second reaction zone at a pressure in the range from 5*105 to 40*105 Pa and at a temperature above the melting point of polymer (VII) to a conversion, based on the molar amount of lactam (I), of at least 80% to form a polymer (VII), then reacting polymer (V) and polymer (VII) with each other in a third reaction zone at a pressure in the range from 1*105 to 1.

Abstract: Copolymers of lactide and glycolide with high glycolide content. The average glycolate block length is less then about 3, which allows the copolymer to be soluble in slightly polar solvents such as methylene chloride.

Abstract: Polyamides are prepared from aminonitriles and water by (1) reacting the aminonitriles with water at from 180 to 350° C. and such a pressure in the range from 30 to 120 bar that a gaseous phase is present as well as a liquid phase, in a first reaction stage, (2) expanding the reaction mixture obtained in the first reaction stage via an evaporator zone or adiabatically with removal of water and ammonia into a second reaction stage, and (3) postcondensing in the second reaction stage at from 0.1 mbar to 5 bar and from 230 to 320° C.

Abstract: A polyamide is prepared by reacting at least one dinitrile and at least one diamine with water at a temperature from 90 to 400° C. and a pressure from 0.1 to 50*106 Pa in a molar ratio of at least 1:1 for water to the sum total of dinitrile and diamine in the presence of a heterogeneous catalyst selected from the group consisting of aluminum oxide, tin oxide, silicon oxide, oxides of the second to sixth transition group of the periodic table, oxides of the lanthanides and actinides, sheet-silicates and zeolites.

Abstract: The invention concerns a method for making polyamide. More particularly, the invention concerns a method for making polyamides derived from the reaction between a diacid and a diamine. It concerns a method for making a polyamide derived from the reaction of at least a diacid with at least a polyamide comprising the following steps: preparing a first mixture of diacid and diamine with a diacid/diamine molar ratio ranging between 0.8 and 0.995, preferably ranging between 0.95 and 0.99 in a first reactor (5); preparing a second mixture of diacid and diamine with a diacid/diamine molar ratio ranging between 1.005 and 1.2, preferably between 1.01 and 1.05, in a second reactor (4); introducing in melted form a first flow of the first mixture and a second flow of the second mixture in a stirred polymer reactor (7); drawing, preferably, continuously, from said reactor a flow of polyamide prepolymer; feeding said polyamide flow into a finishing step to obtain the desired degree of polymerisation.

Abstract: The present invention provides a polyimide resin, a resin composition, an adhesive solution, a film-state joining component, and an adhesive laminate film soluble in a solvent having excellent heat resistance and adhesion, capable of bonding and curing at relatively low temperatures.

Abstract: A nonwoven web and method of preparing a novel nonwoven web of synthetic fiber are disclosed. An aqueous solution amide crosslinked synthetic precursor polymer is extruded under defined conditions through a plurality of die orifices to form a plurality of threadlines. The threadlines are attenuated with a defined primary gaseous source to form fiber under conditions of controlled macro scale turbulence and under conditions sufficient to permit the viscosity of each threadline, as it leaves a die orifice and for a distance of no more than about 8 cm, to increase incrementally with increasing distance from the die, while substantially maintaining uniformity of viscosity in the radial direction, at a rate sufficient to provide fiber having the desired attenuation and mean fiber diameter without significant fiber breakage. The attenuated threadlines are dried with a defined secondary gaseous source. The resulting fibers are deposited randomly on a moving foraminous surface to form a substantially uniform web.

Abstract: In the method for solid-phase drying or solid-phase polymerizing a polyamide of the present invention, the polyamide that is stored for 20 days or longer after the production thereof until subjected to the solid-phase drying or the solid-phase polymerization under the specific conditions is used as the starting material. By storing the polyamide under the specific conditions of the present invention, the resultant solid-phase dried or solid-phase polymerized polyamide with a low yellowness is obtained even if 20 days or more time has lapsed after the starting polyamide is produced until it is subjected to the solid-phase drying or solid-phase polymerization.

Abstract: A medical implant having at least a portion thereof made of a formable, pyromellitic, dianhydride (PMDA)-free, non-halogenated, aromatic polyimide is disclosed. Further disclosed are a process of manufacturing the implant and a method of implanting the implant in a subject in need thereof.

Abstract: The invention describes polyamides having both strongly hydrophilic groups and unsaturated groups, the polyamides consequently being water-dispersible and curable. The hydrophilic groups are distributed along the chain, whereas the unsaturated groups are located at the ends. The polyamides of the invention are useful in many applications, especially in the preparation of intimate blends of polyamides with vinyl, acrylic and/or styrene polymers.

Abstract: An acid dianhydride, together with a diamine, is heated in an organic polar solvent in the presence of &ggr;-caprolactone or &bgr;-butyrolactone as an acid catalyst to prepare a polyimide having an average molecular weight of 10,000 to 300,000. This production process can realize the production of a polyimide which is soluble in a solvent and has high processability and stability.

Abstract: A polyamide, the enzymatic reaction product of at least one polyamine and diester, and processes for preparing and using the same. In addition, processes for preparing and using the enzymatic reaction product as creping adhesives and wet strength resins to make cellulose products.

Abstract: A zwitterionic polyamine comprising a linear or branched hydrophobic polyamine backbone having 2 to 10 tertiary amino nitrogen atoms and a spacer between two tertiary nitrogen atoms wherein the spacer is, for example selected from C8-C16-alkylene, C5-C15-cyloalkylene, wherein in formula (IV) R═C1- to C22-alkyl or C7-C22-aralkyl and n=3 to 6, at least one tertiary amine end group of the polyamine backbone contains two groups having formula (V) or (VI), wherein A means an ethylene oxide unit, a propylene oxide unit, a unit of butylene oxides and a tetrahydrofuran unit, n is a number of from 1 to 50, X is an anionic group such as —SO3M, with the proviso that in formula (VI) one X may also be hydrogen and M is hydrogen, alkai metal or ammonium, or contains one group of formula (V) or (VI) and one group selected from radicals consisting of formula (VII), C1- to C22-alkyl and C7-C22-aralkyl the meaning of A and n is the same as in formula (V) or (VI), said zwitterionic polyetherpolyamine having a

Abstract: A substantially transparent, moldable, thermoplastic multipolymer composition comprising a methyl methacrylate copolymer containing a predominant amount of methyl methacrylate and a minor amount of one or more ethylenically unsaturated monomers; and an effective amount of a polyetheresteramide to enhance the electrostatic charge dissipation of the copolymer. The polyetheresteramide has a refractive index within about 0.005 units of the refractive index of the copolymer. The composition, when subjected to injection molding, is such that the injection-molded composition exhibits a haze of not greater than about 25% and a light transmission of at least about 60%. Preferably, the composition includes an impact modifier which also has a refractive index within about 0.005 units of the refractive index of the copolymer. The composition may also include a minor amount of a polyethylene glycol having a weight average molecular weight of about 2,000 to about 10,000.

Abstract: A laminate film showing good durability under pressure and heat application, and suitably used as a fixing film for toner image fixation, is provided. Such a laminate film is provided by forming a polyimide resin layer on a metal base layer at a controlled imidation percentage of 70-93%.

Abstract: Hot melt adhesives are prepared using thermoplastic polyamides derived from polymerized fatty acid components. The adhesives are particularly useful for bonding nonpolar substrates such as poly-&agr;-olefins.

Abstract: The present invention provides an amine or polyamine, which has a surface activity not inferior to a solid tallow-based amine and an excellent workability. A salt of the amine is suited for emulsifying asphalt and the like, and also provides an asphalt emulsion composition which is obtained by using the salt and which has a quick setting property. Namely, the prevent invention provides a polyamine represented by the formula (1), a process for producing the amine, and an asphalt emulsion composition containing a water-soluble salt of the amine. wherein R is a straight or branched hydrocarbon group having 8 to 22 carbon atoms; x is a number of 1 to 5; and each of y and z is a number of 0 to 5 with the proviso that both of y and z are not 0 at the same time.

Abstract: The present invention contemplates poly(aminoamide) pre-polymers, polyamide polymers, a multi-step process for the synthesis of these pre-polymers and polymers using acrylates and at least one monomer containing at least two primary amines, and the resins resulting from the reaction of the polymers with an epihalohydrin. These resins may be used as wet strength resins and creping aids in the papermaking industry as well as surface additives for wool.

Abstract: Polylactic acid is produced from dimers of lactic acid in an energy saving manner by contacting a lactic acid source via an extraction membrane with an amine carrier solvent to extract lactic acid across the membrane. One or two membranes may be used. After extraction, the aminium lactate salt is crystallized, disassociated and purified.