Abstract: The invention relates to new thermoplastically processible transparent polyamide molding materials based on copolyamides containing diamines and dicarboxylic acids with aromatic cores which exhibit a high index of refraction nD20 over 1.59 and a low density under 1.3 g/cm3. At the same time, a low birefringence, high hardness, and scratchresistance are achieved. The polyamide molding materials are fabricated by means of conventional pressure reactors (autoclaves) according to a modified technique. The granulate that is produced from the inventive molding materials is reshaped by thermoplastic processes like injection molding, particularly in multichamber cavity tools. The invention also relates to the utilization of the inventive molding materials for producing optical lenses.

Abstract: A method of producing polyamide nanocomposites from partially crystalline polyamides and organically modified layered silicates in a double screw extruder is disclosed, a first part of the polyamides being dosed into the extruder intake and melted and the organically modified layered silicate being admixed with the melt of the polyamides and then a second part of the polyamides being added to the mixture. The method according to the present invention is distinguished in that the resulting melt is subjected to filtration. Injection molded parts and vehicle driving illuminator reflectors made of the polyamide nanocomposite molding compound produced according to the present invention are also disclosed.

Abstract: A polyamide molding compound is disclosed having a partially crystalline poly-amide, which includes partially aromatic copolyamides and classic mineral fillers and is distinguished in that the mineral filler is ultrafine chalk (CaCO3) and has an average particle size of at most 100 nm. The polyamide molding compound preferably includes at most 40 weight-percent ultrafine chalk. This polyamide molding compound is preferably used for the production of reflectors and/or sub-reflectors of vehicle driving illuminators with subsequent, direct metal coating.

Abstract: Disclosed is an injection molding method for manufacturing plastic parts from thermoplastically processible plastic molding materials with at least one exposed part (1) and at least one functional part (10), whereby the plastic molding material for the exposed part (1) comprises a transparent or translucent matrix with added effect pigments, and whereby the functional parts (10) can exhibit different physical and/or chemical plastic properties to the exposed parts (1).

Abstract: The present invention relates to semiaromatic semi-crystalline thermoplastic polyamide moulding materials having improved processing behavior, increased flowability, improved surface quality and improved mechanical properties, in particular, in conditioned state, the matrix of the polyamide moulding materials according to the present invention comprising at least 3 components: a semi-crystalline copolyamide (A) having the composition 66/6I/6T, a PA prepolymer (B) having the composition 6T/6I/66 or 6T/6I/6 and an amorphous copolyamide (C) having the composition 6I/6T.

Abstract: The invention relates to reinforced thermoplastic polyamide molding materials having simultaneously good surface quality, good flowability and good heat dimensional stability, from polyamide compositions on the basis of semi-crystalline semi-aromatic polyamides and copolyamides having a melting point of at least 240° C. (A) and amorphous (co)polyamides (B). The molded articles produced by the molding materials according to the present invention are used for production of interior and exterior parts, especially having structural or mechanical function in the fields of electric components, electronics, telecommunication, automobile, transport, packaging, domestic, furniture, sports, apparatus engineering, machine construction, heating installation, air conditioning, and sanitation.

Abstract: The invention relates to a thermosetting coating mass, comprising a carboxyl functional polyester, and/or a carboxyl functional polyacrylate, a ?-hydroxyalkylamide, in which a portion of the hydroxyl groups are chemically blocked and/or fillers and/or heat stabilisers and/or triboadditives and/or further additives, such as, for example, dispersing and degassing agents.

Abstract: Transparent polyamide molding materials are provided which are characterized in that they have a melting enthalpy between 0 and 12 J/g and the polyamides are constituted of 100 mole-% of a diamine mixture having 10-70 mole-% of PACM [bis-(4-amino-cyclohexyl)-methane] with less than 50 wt.

Abstract: The snap connection for sealed and releasable connection of a first tube end with a second tube end, with spring arms, with a first outer stop projection on the first tube end, with a first elastically deformable ring connected with the spring arms, and with two first inner stop cams on the first ring cooperating with the first outer stop projection, is characterized by a second outer stop projection on the second tube end, a second elastically deformable ring connected with the spring arms with distance from the first ring, and by two, second inner stop cams on the second ring cooperating with the second outer stop projection. Both rings with their stop cams, connected to one another via the spring arms, form a double-connection element separable by and on both tube ends, which can be made from a plastic injection molding part.

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: In the process for producing a cyclododecanone by isomerizing an epoxycyclododecane-containing starting material in the presence of an isomerization reaction catalyst containing lithium bromide and/or lithium iodide, in order to perform the reaction with high efficiency (high reaction rate) and high selectivity and stably produce a high-purity cyclododecanone in industry while maintaining a high-level reaction rate, the epoxycyclododecane-containing starting material is produced by contacting an epoxycyclododecadiene with hydrogen in the presence of a hydrogen-reduction catalyst and has a content of the hydroxyl group-containing cyclododecane compounds contained in the epoxycyclododecane-containing starting material controlled to 5 mol % or less.

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 car industry increasingly uses plastic optical fibers whose protective sheathing (4) is made of a polyamide. As unmodified PA poorly adheres to the fluoropolymers often used as the material for the fiber cladding (3), the plastic optical fiber (2, 3) moves in relation to the protective sheathing (4) when the temperature varies. To suppress this effect referred to as “pistoning”, the connectors and holders of the optical fibers must apply very large clamping forces to the protective sheathing (4) and the plastic optical fiber (2, 3) arranged therein, resulting in an increased signal attenuation. The use of a modified PA can clearly improve the adherence of the protective sheathing (4) to the cladding (3) of a plastic optical fiber which is made of a fluoropolymer.

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: The snap connection for sealed and releasable connection of a first tube end (10) with a second tube end (20), with spring arms (33), with a first outer stop projection (14) on the first tube end (10), with a first elastically deformable ring (31) connected with the spring arms (33), and with two first inner stop cams (34) on the first ring (31) cooperating with the first outer stop projection (14), is characterized according to the present invention by a second outer stop projection (23) on the second tube end (20), a second elastically deformable ring (32) connected with the spring arms (33) with distance from the first ring (31), and by two, second inner stop cams (35) on the second ring (32) cooperating with the second outer stop projection (23). Both rings with their stop cams, connected to one another via the spring arms, form a double-connection element (30) separable by and on both tube ends (10, 20), which can be made from a plastic injection molding part.

Abstract: Two-layered or three-layered polymer tubing for use as a pressurized fluid conduit in automobiles can be either walled or have walls continuously or partially corrugated. The tubing has an outer layer of a hard polymer molding material and an inner layer of a soft rubber-like polymer or a polymer mixture. The inner layer can be provided on the innerside with a layer of a thermoplastic adhesion-modified elastomer composition. The a materials are selected for the layers to provide a so-called “hard-soft-combination”. The rubber-like polymer composition has a hardness in the range of 30 Shore A to 60 Shore D, especially of about 30 Shore A to 90 Shore A, the compositions being selected so that they are processable by coextrusion or the so-called conex method and adhere directly to each other non-positively or positively fitted, i. e. without additional bonding agent, without delaminating.

Abstract: Copolyamides, consisting of polycondensation products of the following components: caprolactam 10 to 45 mol-%, laurolactam 30 to 55 mol-%, at least 2 dicarboxylic acids 20 to 50 mol-% of the following compounds, aliphatic &agr;,&ohgr;-dicarboxylic acids with 6 up to 14 C atoms inclusively, terephthalic acid, isophthalic acid and 2,6-naphthalene dicarboxylic acid, wherein the content of aromatic dicarboxylic acids is lower than 10 mol-%, with reference to the allover amount of the above-mentioned components, which add up to 100 mol-%, a diamine mixture in an amount that is equimolar to that of the dicarboxylic acids, chosen from the group of the following substances, hexamethylene diamine, piperazine and/or 2-methyl-1,5-diaminopentane, wherein the molar content of hexa-methylene diamine is between 75 and 95 mol-% with reference to the diamine mixture. The copolyamides according to the invention are used for the production of mono- and multifilaments, fibers, films and nets.

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.

Abstract: Thermoplastic multilayer composite, particularly in the form of a multilayer hose, a multilayer pipe or a multilayer container, containing at least one intermediate layer made of a molding compound on the basis of ethylene/vinyl alcohol copolymers between layers made of molding compounds on the basis of polyamide, the intermediate layer being bonded via at least one adhesion-promoting layer made of a molding compound on the basis of polyamide selected from the group of copolyamide 6/12, block copolyamide 6/12, polyamide 612, polyamide 610, a mixture of polyamide 6 and polyamide 12 with compatibilizer, a mixture of polyamide 6 and polyamide 11 with compatibilizer, with at least one neighboring layer made of a molding compound on the basis of polyamide 12, polyamide 11, polyamide 1010, polyamide 1012, or polyamide 1212.