Abstract: In the production of polyamide by the melt-polymerization of the present invention, the polymerization conditions are rapidly and accurately controlled by a near-infrared spectroscopy to enable the efficient production of a desired polyamide with a good stability in its quality.

Abstract: Polymer derivatives based upon polyalkyleneimine backbones having a color stabilizing-effective amount of their reactive amino functionalities substituted by either a carboxylic acid or an amino-protecting group such as urea, are disclosed. Methods for preparing said derivatives are also disclosed. Fiber lubricant compositions comprising said polymer derivatives, and the resistance to yellowing associated with such lubricants are disclosed. Also disclosed are methods for treating fibers using the polymer derivatives.

Abstract: A graft copolymer is prepared by a process comprising: graft polymerizing a polyamide-forming monomer selected from the group consisting of lactams and &ohgr;-aminocarboxylic acids and an oligocarboxylic acid selected from the group consisting of from 0.015 to about 3 mol. % of dicarboxylic acid and from 0.01 to about 1.2 mol. % of tricarboxylic acid, in each case the stated amounts of oligocarboxylic acid based on a molar amount of lactam, &ohgr;-aminocarboxylic acid or combination thereof, onto from 0.5 to 25% by weight, based on the graft copolymer, of a polyamine having at least 11 nitrogen atoms and a number-average molecular weight Mn of at least 500 g/mol., wherein the amino group concentration in the graft copolymer ranges from 100 to 2500 mmol./kg.

Abstract: A process for making partially aromatic polyamides is provided in which an aromatic dicarboxylic acid component, at least 20-100% by weight of the dicarboxylic acid in the acid component is in the form of an alkylated ester, and a diamine component, comprising a diamine having from 6-12 carbon atoms, are admixed in the presence of water and with heating to form polyamide having from 1-100% on a molar basis of N-alkylated amide and amine groups. The polyamides are particularly useful in the manufacture of products intended for use at elevated temperatures or products in which retention of properties at elevated temperatures is required, including articles using injection molding technology, parts for automotive end-uses and electronics. The polyamides can also be formed into films and fibers for use in associated products.

Abstract: The batch process for producing a polyamide by reaction of a mixture comprising at least one aminonitrile, and optionally monomers useful for polyamide production, with water, comprises the following steps: (1) reacting the mixture with water at a temperature from 90 to 400° 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 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 370° C.

Abstract: The improved polyamide production method of the present invention is characterized by including a step of accurately regulating the molar balance between a diamine component and a dicarboxylic acid component to a desired balance in a batch-wise regulation tank, thereby preparing a slurry liquid substantially free from the amidation reaction. The slurry liquid thus prepared is fed to a batch-wise or continuous polymerization reactor, where the amidation reaction is proceeded to easily produce polyamide having a desired balance of the diamine component and the dicarboxylic acid component without causing a problem such as foaming, solidification, etc.

Abstract: A multi-stage process for the manufacture of branched aliphatic polyamides is provided. The process comprises the steps, in sequence, of feeding to a reactor a slurry of at least one aliphatic dinitrile, and at least one aliphatic diamine, at least one of which is branched, in the presence of 0.05 to 2% by weight of a phosphorous-containing compound, with the incremental addition of water, heating the slurry to a temperature of at least 270° C. while maintaining a pressure of at least 1.2 Mpa, venting water, ammonia and other volatile matter from the reactor while maintaining the temperature and pressure, maintaining the temperature for a further period of time while reducing the pressure to at least atmospheric pressure and then discharging the polyamide so formed. Polyamides made by this process are substantially the same as corresponding polyamides made by the conventional salt-strike process, and can be used in molding, coating and film applications.

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: 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.