Abstract: The invention concerns copolyamides obtained by using multifunctional monomers. It consists in using a multifunctional monomer comprising at least three reactive functions and at least another multifunctional monomer, in amounts such that the terminal group concentrations are balanced. The copolyamides are particularly high viscosity copolyamides. The invention also concerns compositions based on said copolyamides.

Abstract: The invention concerns copolyamides obtained by using multifunctional monomers. It consists in using at least one multifunctional monomer comprising at least three reactive functions and at least another multifunctional monomer, in amounts such that the terminal group concentrations are balanced. The copolyamides are more particularly high viscosity copolyamides. The invention also concerns compositions based on said copolyamides.

Abstract: A method is disclosed for producing a polyamide molding compound which includes the following method steps: addition and dissolving of m-xylylene diamine and dicarboxylic acids, which include adipic acid and aromatic dicarboxylic acids, with water and additives in a dissolving chamber and production of a mixture, the sum of the aromatic dicarboxylic acids added being 2 mol-percent to 15 mol-percent (in relation to the addition of dicarboxylic acids); transfer of the mixture into a reaction vessel and polycondensation of the mixture in this reaction vessel; granulation of the polycondensate; drying of the granulate. This method is distinguished in that the polycondensation is performed at a pressure of at most 10 bar and a temperature of 255° C. to 270° C., the pressure being built up while heating the reaction vessel to 255° C. to 270° C. and—immediately after the mixture has reached the maximum temperature—being reduced to atmospheric conditions while maintaining a temperature of 255° C. to 270° C.

Abstract: The invention relates to a liquid initiator for carrying out anionic lactam polymerization. The liquid initiator contains a conversion product of isocyanate (1) with a protic compound (P) and a base (B) in an aprotic solvation agent (S).

Abstract: A process for preparing a polymer, which comprises a) reacting a mixture (I) containing 6-aminocapronitrile and water in the presence of a catalyst to obtain a mixture (II) containing caprolactam, ammonia, water, high boilers and low boilers, then b) removing ammonia from mixture (II) to obtain a mixture (III) containing caprolactam, water, high boilers and low boilers, then c) removing all or some of the water from mixture (III) to obtain a mixture (IV) containing caprolactam, high boilers and low boilers and then d) feeding mixture (IV) to a polymerization reaction, and also the polymer obtainable by this process, the use of the polymer for producing fibers, sheetlike structures and moldings, and also fibers, sheetlike structures and moldings obtainable using such a polymer.

Abstract: Disclosed is a process for reducing low molecular weight impurities, namely caprolactam and its oligomers, from Nylon-6 pre-polymer during the preparation of Nylon-6 polymer.

Abstract: The invention relates to hyperbranched copolyamides (HBPAs), to their production and to their use as additives, in particular as melt viscosity modifiers in thermoplastic polymer compositions. This copolyamide is obtained by a reaction between a monomer (I): A—R—Bf with A and B=polymerization functions of a 1st and 2nd type, respectively, which are capable of reacting with each other, R=hydrocarbon-based species and f=total number of B per monomer (preferably 2?f?10); and a monomer (II) A?—R?—B? or the corresponding lactams, with A?, B? and R? having the same definition as that given above for A, B and R, respectively. This HBPA has a I/II molar ratio such that 0.125?I/II?2. One of the species R or R? of (I) or (II) is aliphatic, cycloaliphatic or arylaliphatic. For example: A=NH2 and B=COOH or A=COOH and B=NH2 with F=2. A?=NH2 and B?=COOH or A?=COOH and B?=NH2. A—R—B2, e.g.: 5-aminoisophthalic acid or 3,5-diaminobenzoic acid and A?—R?—B?=?-caprolactam.

Abstract: The invention relates to modified polyamides, and more particularly to polyamides containing units of the type obtained by reacting a diacid with a diamine, modified with a multifunctional compound. The finished articles shaped from these polyamides or from compositions based on these polyamides have excellent mechanical properties and also a very good surface aspect. The modified polyamide according to the invention is obtained by melt-blending polyamides of different natures, in the presence of a multifunctional compound.

Abstract: A process for the simultaneous preparation of polyamide-6 with at least two different viscosities comprising prepolymerisation of ?-caprolactam and/or other polyamide-6 precursors in the presence of water, wherein at least part of the necessary water is supplied to the prepolymerisation via the gas phase and the obtained prepolymer is progressively moved and treated with an inert gas in at least two condensation reaction zones or reactors, placed in series, and the prepolymerisation and condensation are carried out in reactor(s) or reaction zones having a self-renewing interface between molten phase and gas phase with a large surface/volume ratio of the molten phase and the molten phase is relatively strong mixed.

Abstract: The invention relates to a liquid initiator to be used in anionic lactam polymerization. Said liquid initiator contains a reaction product of carbodiimide with a protic compound and a base in an aprotic solvation agent.

Abstract: The polyamide resin of the present invention is produced by polycondensation of a diamine component comprising 70 mol % or more of m-xylylenediamine and a dicarboxylic acid component comprising 70 mol % or more of a C4-C20 ?, ?-straight-chain aliphatic dicarboxylic acid in the presence of at least one phosphorus compound selected from the group consisting of phosphinic acid compounds and phosphonous acid compounds and in the presence of an alkali metal compound of a weak acid. The weak acid has a dissociation constant lower than a first dissociation constant of a dicarboxylic acid mainly constituting the polyamide resin. The polyamide resin satisfies the following requirements (A), (B) and (C): 14000?a?40000??(A) b?1.000??(B) 0.9930?b?1.1a2×10?11+3.2a×10?7?0.9980??(C) wherein a and b are as defined in the disclosure.

Abstract: The invention relates to a process for the preparation of a polyamide comprising at least a step in which a composition that comprises at least (a) a primary aminocarbonamide and (b) an aminocarboxylic acid and/or a lactam is polymerised, said composition comprising at least (a) 10-90 wt. % primary aminocarbonamide; (b) 10-90 wt. % aminocarboxylic acid and/or lactam; (c) 0-4 wt. % water; the amounts being relative to the sum of the compounds (a+b+c). Preferably the sum of the compounds (a+b+c) is at least 75 wt. % of the total composition, more preferably 85 wt. %, most preferably 90 wt. %. The polyamide obtained with the process has a &eegr;rel of more than 2.2. The process is eminently suitable for the preparation of polyamide-6 (polycapronamide) from a composition comprising 6-aminocapronamide, 6-aminocaproic acid and/or &egr;-caprolactam. This composition is preferably obtained via the reductive amination of a 5-formylyalerate ester, preferably 5-formylmethylvalerate in water.

Abstract: A series of initiators based on transition metal complexes for the polymerization of optically active beta-lactams into poly-beta-peptides and block copolymers have been developed. These initiators are unique in being able to eliminate chain transfer and chain termination side reactions from these polymerizations resulting in narrow molecular weight distributions, molecular weight control, and the ability to prepare copolymers of defined block sequence and composition.

Abstract: The continuous process for preparing a polyamide by reacting at least one aminonitrile with water comprises: (1) reacting at least one aminonitrile with water in the presence of an organic liquid diluent at from 90 to 400° C. and from 0.1 to 35×106 Pa in a flow tube containing a Brönsted acid catalyst selected from a beta-zeolite catalyst, a sheet-silicate catalyst or a titanium dioxide catalyst comprising from 70 to 100% by weight of anatase and from 0 to 30% by weight of rutile and in which up to 40% by weight of the titanium dioxide may be replaced by tungsten oxide, to obtain a reaction mixture, (2) further reacting the reaction mixture at from 150 to 400° C.

Abstract: A method for preparing nylon 6 copolymer containing 5-sulfoisophthalate salts comonomer. The method includes the steps of reacting 5-sulfoisophthalate salts ester with aliphatic diamine in a molar ratio of 2˜20 at 160˜200° C., followed by completely removing the unreacted aliphatic diamine, to obtain the intermediate compound with terminal amine, 5-sulfobenzenediamide compound (formula III). Next, caprolactam and aliphatic diacid (formula IV) are reacted at 200˜260° C. to form an oligomer with a low molecular weight. 5-Sulfobenzenediamide (formula III) and catalyst are then added into the oligomer obtained in previous step to cause a polymerization reaction at 200˜280° C. to obtain nylon 6 copolymer containing 5-sulfoisophthalate salt comonomer. The molar ratio of E/C is 0.005˜0.150 and the molar ratio of D/E is 1.05-1.00. Compounds present in the water extract are greatly reduced.

Abstract: A process for the preparation of novel polyamides, the use of such polyamides for the production of fibers, sheets and moldings, and fibers, sheets and moldings obtainable from such polyamides, are provided.

Abstract: The invention relates to a polyamide with low viscosity degradation after remelting which can be produced by anionic polymerization of lactam in the presence of alkaline catalysts and if necessary activators and the method for production of the polyamide. The invention relates furthermore to a method for reprocessing anionically produced polyamide.

Abstract: A modified polyamide polymer having a high amino end group content, with more than 30 percent of the amino end groups being secondary or tertiary amine, dramatically improves the dye bleed performance. The modified polyamide may be prepared by polymerization of polyamide-forming monomers in the presence of a carboxylic acid and a hindered piperidine derivative in amounts sufficient to achieve the high amino end group content.

Abstract: A separating agent that serves as an optical resolution agent is composed of a novel, useful optically active polymer. The separating agent is obtained through anionic polymerization of a novel maleimide and serves to separate optically active compounds.

Abstract: A process for the preparation of novel polyamides, the use of such polyamides for the production of fibers, sheets and moldings, and fibers, sheets and moldings obtainable from such polyamides, are provided.

Abstract: There is provided a process for the continuous polymerization of polyamides which is carried out under conditions of pressure, temperature and polymer concentration in water that will ultimately yield multiple phases (including a second liquid polymer phase or a polymer precipitate). However, a single phase operation is achieved under these conditions by appropriate management of residence time and using a well-mixed reaction environment in early stages of the polymerization.

Abstract: The present invention relates to a process for preparing polyamide 6 (PA 6) by hydrolytic polymerization of &egr;-caprolactam. In a first reaction step, a first intermediate mixture is formed by ring opening &egr;-caprolactam in the presence of water, under conditions of increased pressure and temperature. The first intermediate mixture is then dehydrated to form a dehydrated intermediate having a water content of less than 0.5 wt. %. The dehydrated intermediate is subsequently polymerized to. produce a polyamide 6 product having a low dimer content (e.g., of less than 0.3 wt. %). The invention also relates to an apparatus in which the process may be performed. The apparatus includes, in sequence, a pressure reactor (23) having heat exchange surfaces (36), a dehydration device (24) that is in fluid communication with the pressure reactor (23), and a main reactor (25) that is in fluid communication with the dehydration device (24).

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 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: 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: 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: An optically active poly(N-&agr;-methylbenzylmaleimide) represented by the following formula (1): 1

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: For the preparation of powders formed of copolyesteramides by anionic polymerization, at least one lactam and at least one lactone are copolymerized in solution in a solvent in the presence of a catalyst and of an activator, the solvent being a solvent of the lactam and the powders being insoluble in the solvent. Preferably at least two lactams and at least one lactone are copolymerized, and the copolymerization is preferably carried out in the presence of a finely divided organic or inorganic filler. The copolymerization is preferably carried out in the presence of an N,N′-alkylenebisamide, such as ethylenebisstearamide (EBS) disclosed in EP 192 515, or generally amides of formula R1-NH—CO—R2, in which R1 can be replaced by an R3-CO—NH— or R3-O— radical and in which R1, R2 and R3 denote an aryl, alkyl or cycloalkyl radical.

Abstract: A water absorbent material, comprising, as a main component, a water absorbent resin which has a structure in which a anhydropolyamino acid having an ethylenically unsaturated double bond is grafted with polysaccharides, wherein at least a portion of the anhydropolyamino acid is hydrolyzed and crosslinked, has high water absorbency and high biodegradability even if the anhydropolyamino acid has a low molecular weight.

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: The invention relates to a liquid initiator for carrying out anionic lactam polymerization. The liquid initiator contains a conversion product of isocyanate (1) with a protic compound (P) and a base (B) in an aprotic solvation agent (S).

Abstract: A process for preparing a polymer, which comprises

Abstract: (Co)polyamides, for example the polyamides 6 and 66, are prepared via the improvedly catalyzed polycondensation of (co)polyamide-forming (co)monomers, even in the presence of normally catalyst-inhibiting matting agents (e.g., microparticulate TiO2), the catalyst therefor comprising solid nanometric TiO2 particulates having diameters of less than 100 nm.

Abstract: Described is the use of metal oxides as heterogeneous catalysts in a process for producing polyamides by polymerization of lactams and optionally further polyamide-forming monomers wherein the metal oxides are used in a form which permits mechanical removal from the reaction mixture and are removed from the reaction mixture during or after the polymerization, to reduce the extractables content of the polyamide obtained.

Abstract: A process for the preparation of novel polyamides, the use of such polyamides for the production of fibers, sheets and moldings, and fibers, sheets and moldings obtainable from such polyamides, are provided.

Abstract: This invention provides processes of the preparation of polyamides, polyimides, and polyamideimides, which are easy to purify after reactions, from polycarboxylic acids and polyamines in high yield without side reactions such as a change of color to black by direct polycondensation reaction with heat, especially processes of preparing aromatic polyamides (aramids), aromatic polyimides, and aromatic polyamideimides, which are difficult to synthesize in direct polycondensation reaction. Polyamides, polymides, and polyamideimides are prepared in high yield by the polycondensation of aromatic dicarboxylic acids, aromatic tetracarboxylic acids or aromatic tricarboxylic acids and aromatic diamines, using arylboric acids such as 3,4,5-trifluorophenylboric acids as polycondensation catalysts, in a mixed solvent of pentamethylbenzene and N-methylpyrrolidinone or a mixed solvent of m-terphenyl and N-butylpyrrolidinone.

Abstract: For the anionic polymerization of lactams: (a) (i) a catalyst capable of creating a lactamate and (ii) a regulator chosen from amides of formula R1-NH—CO-R2, in which R1 can be substituted by an R3-CO—NH— or R3-0— radical and in which R1, R2 and R3 denote an aryl, alkyl or cycloalkyl radical, are dissolved in the molten lactam, (a1) the solution from stage (a) is cooled, optionally to the solid state in a form which can be divided, (a2) the product from stage (a1) is optionally reheated to a temperature below the polymerization temperature of the lactam, (a3) optionally, the product from stage (a1) is reheated and is maintained at a temperature between the melting temperature of the lactam and 15° C. above, and (b) the produce from any one of stages (a1), (a2) or (a3) is introduced into a mixing device or mold and is then heated to a temperature sufficient to obtain the bulk polymerization of the lactam.

Abstract: In a process for producing polyamides, a mixture comprising hexamethylenediamine and aminocapronitrile and obtained from the hydrogenation of adiponitrile is reacted with water and a dicarboxylic acid.

Abstract: A process for the production of polyamides is disclosed. In a first reaction step, suitable monomers such as caprolactam or an aliphatic aminocarboxylic acid are reacted with polyfunctional amines, which contain at least one secondary amino group, and/or with salts containing such amines and dicarboxylic acids. The reaction product is in a further process step undergoes solid phase post-condensation.

Abstract: The invention relates to a granule and granulate and to a process for the preparation of polyamide granules at least comprising a) polymerizing at least one dicarboxylic acid and at least one diamine until a low-molecular prepolymer powder is obtained; b) processing the prepolymer powder obtained in step (a) to form granules, with the prepolymer powder being extruded at a temperature, measured under the chosen extrusion conditions, below the melting point of the prepolymer. The process of the invention allows the production of granules that have a higher granule strength than that according to the state of the art. The process of the invention also produces fewer fines. It is preferred for polyamide-4,6 to be chosen as polyamide. The granules and the granulate obtained by the process of the invention are particularly suited for post-condensation.

Abstract: The invention provides a poly(imide-benzoxazole) (PIBO) copolymer prepared from a trimellitic anhydride halide monomer and a bis(o-diaminophenol) monomer. The PIBO copolymer is characterized by the following recurring unit: wherein X is —O—, —S—, —C(CF3)2—, —C(CH3)2—, —CO—, —CH2—, —SO2—, —SO—, or deleted; and n is an integer. The PIBO copolymers of this invention are particularly useful as dielectric layers in semiconductor devices because they possess hydroxyl groups which create better adhesion to semiconductor substrates.

Abstract: A process for producing polyamides by reacting at least one lactam and optionally further polyamide-forming monomers with aqueous monomer and oligomer extracts obtained during the extraction with water of the polymer product obtained in the production of polyamides, the water content of the reaction mixture being in the range from 0.5 to 13% by weight comprises conducting the reaction in the presence of metal oxides, beta-zeolites, sheet-silicates or silica gels, which may be doped, as heterogeneous catalysts, the heterogeneous catalysts being used in the form which permits mechanical removal from the reaction mixture and are removed from the reaction mixture in the course of the polymerization or after it has ended.

Abstract: Highly branched polyamides prepared in a single step procedure of condensation polymerization of multifunctional monomer reactants comprising amine and carboxylic acid functional groups. Polymerization proceeds by reaction of an amine group of a first monomer unit with an acid group of a second monomer unit to form a reaction product having an amide linkage between the first and second monomer units and repetition of such amidation reaction between additional amine groups and acid groups of the multi-functional monomers and reaction products of the multi-functional monomers. In the present invention, in order to obtain a water soluble or dispersible hyperbranched polyamide, at least one of the multifunctional monomer unit reactants contains an amine, phosphine, arsenine or sulfide group, such that the highly branched polyamide contains in the backbone thereof an N, P, As or S atom capable of forming an onium ion.

Abstract: Disclosed are the use of lactams, aminocarboxylic acids or mixtures thereof as acceleratant or cocatalyst in the production of polyamides from aminonitriles and water, and a suitable process therefor.

Abstract: The invention relates to a process for the production of polyamide-6 by polymerization of &egr;-caprolactam with full re-use of extracted caprolactam and oligomers. The extract is not subjected to a pretreatment for reduction of the cyclic dimer content. By carrying out the polymerization in two steps, the first at an elevated pressure, but lower than the vapor pressure of the reaction mixture supplied, and the second at approximately atmospheric or reduced pressure, the cyclic dimer content of the polymerizate leaving the second polymerization step is kept at a constant level. The process offers a high degree of flexibility in terms of production capacity and composition and proportion of recycled lactam in the lactam feed for the polymerization.

Abstract: The invention concerns a polyamide comprising macromolecular chains having a star-shaped configuration, a method for making said polyamide and compositions comprising same. More particularly, the invention concerns a method for making a polyamide comprising linear macromolecular chains and star-shaped macromolecular chains with control of the star-shaped chain concentration in the polymer. Said control is obtained by using besides the polyfunctional polymers and amino acids or lactams a polyfunctional comonomer comprising either acid functions or amine functions. The resulting polyamide has optimal mechanical and rheological properties for improving the speed and quality of mould filling and producing mouldable compositions comprising high filler factors.

Abstract: The continuous process for producing polyamides by reacting at least one aminonitrile with water comprises the following steps: (10) reacting at least one aminonitrile with water at a temperature of from 200 to 290° C. at a pressure of from 40 to 70 bar in a flow tube containing a Brönsted acid catalyst selected from a beta-zeolite, sheet-silicate or metal oxide catalyst in the form of a fixed bed, (11) diabatically or adiabatically expanding the reaction mixture from step (1) into a first separation zone to a pressure of from 20 to 40 bar, the pressure being at least 10 bar lower than the pressure in step (1), and to a temperature within the range from 220 to 290° C. by flash evaporation and removal of ammonia, water and any aminonitrile monomer and oligomer, (12) further reacting the reaction mixture from step (2) in the presence of water at a temperature of from 200 to 290° C.

Abstract: The instant invention provides an aromatic polyamide composition for molding which is of superior rigidity, strength, toughness, dimensional stability, resistance to chemicals, external surface appearance and sliding characteristics in high-humidity, high-temperature environments, which has a low coefficient of linear expansion and which is of low warpage.

Abstract: A process for producing polyamides from dinitriles and diamines in a continuous reaction using subsequent heating steps. In particular, the process involves contacting a dinitrile, a diamine, water, and optionally a catalyst to form a reaction mixture; heating the reaction mixture to a first elevated temperature of between about 180 to about 240° C., maintaining said temperature for about 0.10 to about 20 hours, and optionally controlling the pressure in this heating step by venting; heating the reaction mixture to a second elevated temperature of between about 250 to about 350° C., adding water to the reaction mixture before or after the second elevated temperature is reached, maintaining the pressure in the second heating step above atmospheric pressure by venting at least some of the water, and maintaining the second elevated temperature for a period of about 0.10 to about 10 hours; and recovering the polyamide.