摘要:
A moulding composition contains at least 40 wt % of components a) and b). Based on the sum of components a) and b), there are 60-99 wt % of component a) and 40-1 wt % of component b). Component a) is a partially aromatic copolyamide containing, as polymerized monomer units, 30-90 mol % of a combination of hexamethylenediamine and terephthalic acid and 70-10 mol % of a combination of hexamethylenediamine and a linear aliphatic dicarboxylic acid having 8-19 C atoms. Component b) is an olefinic copolymer containing, as polymerized monomer units, i) 35-94.9 wt % of ethene-based monomer units, ii) 5-65 wt % of monomer units based on a 1-alkene having 4-8 C atoms, iii) 0-10 wt % of monomer units based on an olefin different from i) and ii), and iv) 0.1-2.5 wt % of monomer units based on an aliphatically unsaturated dicarboxylic acid anhydride, where the sum of wt % of i), ii), iii) and iv) is 100%.
摘要:
A metallic pipe for contact with a hydrolyzing medium provides longer operating times and improved high temperature resistance. The pipe contains a layer of a polyamide moulding composition containing at least 50% by weight of polyamide content containing: I) 60 to 98 parts by weight of a polyamide which contains 10 to 70 meq/kg of a terminal carboxy group and has a relative solution viscosity ηrel of at least 1.90, and II) 2 to 40 parts by weight of a polyamine-polyamide graft copolymer produced from: a) 0.5 to 25% by weight, based on the entire monomer mixture, of a polyamine having at least 4 nitrogen atoms, and b) 75 to 99.5% by weight, based on the entire monomer mixture, of polyamide-forming monomers selected from lactams, ω-aminocarboxylic acids and/or equimolar combinations of diamine and dicarboxylic acid, with the proviso that the amino group concentration of the graft copolymer is in the range from 100 to 2500 meq/kg, wherein the sum of the parts by weight of I) and II) is 100.
摘要:
A polyamide molding composition is condensed up in the melt by means of a masterbatch containing a compound having at least two carbonate units and also a polyetheramide in which at least 50% of the end groups are present as amino end groups, whereupon the melt mixture is discharged and solidified to give a molding composition or a molding. The product obtained has an increased amino end group content and consequently an improved hydrolysis resistance.
摘要:
A process for producing moldings with condensing-up of a polyamide molding composition whose polyamide component contains, as a result of the method of preparation, at least 5 ppm of phosphorus in the form of an acidic compound by means of a compound having at least two carbonate units, wherein a) from 0.001 to 10% by weight, based on the polyamide, of a salt of a weak acid is added to the polyamide molding composition prior to compounding or during compounding, b) a mixture of the finished composition and the compound having at least two carbonate units is prepared, c) the mixture is, if appropriate, stored and/or transported and d) the mixture is subsequently processed to produce the molding, with the condensing-up occurring only in this step, effects a significant increase in the melt stiffness combined with moderate processing pressures, which considerably simplifies, in particular, the production of hollow bodies and hollow profiles having large diameters.
摘要:
The invention provides a process for preparing linear alpha,omega-dicarboxylic diesters by reacting a triglyceride containing fatty acid residues having monounsaturated or polyunsaturated carbon chains with carbon monoxide, an acid and an OH-group donor in one reaction step in the presence of a catalyst.
摘要:
A process for producing moldings with condensing-up of a polyamide molding composition by means of a compound having at least two carbonate units, wherein a) a polyamide molding composition is made available, b) a mixture of the polyamide molding composition and the compound having at least two carbonate units is prepared, c) the mixture is, if appropriate, stored and/or transported and d) the mixture is subsequently processed to produce the molding, with the condensing-up occurring only in this step, and the molding is a hollow body or hollow profile having an external diameter of at least 30 mm and a wall thickness of at least 1 mm, effects a significant increase in the melt stiffness combined with moderate processing presssures, which considerably simplifies the production of these moldings.
摘要:
A molding, produced by a layer-by-layer process in which regions of respective polymer pulverulent layers are selectively melted via introduction of electromagnetic energy, where the process employs a powder which comprises at least one homopolyamide prepared via polycondensation of diamines and dicarboxylic acids, wherein the homopolyamide has an enthalpy of fusion of at least 125 J/g and a recrystallization temperature of at least 148° C.
摘要:
Composite particles comprising core particles completely or partially coated with a precipitated polymer, where the d50 median diameter of the core particles is from 3 to 100 μm and wherein the glass core particle material is at least one selected from the group consisting of a solid glass bead, a hollow glass bead, a porous glass bead, and a foamed glass particle. A method to prepare the particles includes dissolution of a polymer in a solvent and precipitation of the polymer in the presence of a suspension of the core glass particles. Further provided is a layer by layer moulding process employing the composite particles and mouldings obtained therefrom.
摘要:
The invention provides a process for preparing linear alpha,omega-dicarboxylic diesters by reacting a triglyceride containing fatty acid residues having monounsaturated or polyunsaturated carbon chains with carbon monoxide, an acid and an OH-group donor in one reaction step in the presence of a catalyst.
摘要:
A pulverulent composition that is a powder containing at least one polymer, and at least one flame retardant that contains ammonium polyphosphate, the powder having a maximum particle size of ≦150 μm and a median particle size of from 20 to 100 μm.