摘要:
The invention relates to powder, comprising composite particles comprising core particles completely or partially coated with a precipitated first polymer, where the core particles comprise a second polymer which differs from the precipitated first polymer, and where the ratio of the d50 median diameter of the composite particles to the d50 median diameter of the core particles is 1.15 or greater. The invention further relates to processes of using the powders of the present invention to making moldings.
摘要:
A molding composition which comprises at least 50% by weight of the following constituents: a) from 0 to 99 parts by weight of polyamide, and b) from 1 to 100 parts by weight of polyamide elastomer, selected from the group of polyetheresteramide and polyetheramide, where the total of the parts by weight is 100 and where the molding composition comprises from 0 to 9% by weight of plasticizer, is used for the production of a molding for contact with a supercritical medium, and preferably for the production of an inner thermoplastics layer in a flexible pipe or rigid pipe, in which a supercritical medium is conveyed. Low or zero plasticizer content eliminates any significant occurrence of problems such as increased stiffness and longitudinal shrinkage.
摘要:
A molding compound, containing at least 30% by weight of a copolyamide, which is derived from the following monomers: a) 50 to 95 mole percent of the combination of a diamine, selected from the group consisting of 1,9-nonane diamine, 1,10-decane diamine, 1,11-undecane diamine and 1,12-dodecane diamine, and terephthalic acid, and b) 5 to 50 mole percent of the combination of a diamine, selected from the group consisting of 2,2,4-trimethylhexamethylene diamine, 2,4,4-trimethylhexamethylene diamine, and mixtures thereof, and terephthalic acid. The copolyamide is crystalline and has low water absorption.
摘要:
A task often encountered in very recent times is the rapid provision of prototypes. Particularly suitable processes are those based on pulverulent materials and in which the desired structures are produced layer-by-layer through selective melting and solidification. The invention provides the constitution, production and use of a copolyamide powder which was produced using the following monomer units: a) laurolactam or ω-aminoundecanoic acid, and also b) dodecanedioic acid, and either c) decanediamine or dodecanediamine, in shaping processes, and also to moldings produced through a layer-by-layer process which selectively melts regions of a powder layer, using this specific powder. Once the regions previously melted layer-by-layer have been cooled and solidified, the molding can be removed from the powder bed. The moldless layer-by-layer processes for the production of components using the copolyamide powder result in simplified and more reliable conduct of the process and better recyclability.
摘要:
In a method for the introduction of an inliner into a pipe or a pipeline, where the external diameter of the inliner is greater than the internal diameter of the pipe or of the pipeline, and where the action of an external force is used to reduce the cross section of the inliner prior to the introduction, the inliner is composed of a polyamide moulding composition which comprises at least 50% by weight of polyamide which is not PA11. The recovery behavior of said polyamides is similar to that of polyethylene usually used for this purpose.
摘要:
The present invention provides precipitated polymer powders based on a polyamide of the AABB type, obtained by the reprecipitation of the polyamides by at least partial dissolution followed by continuous cooling of the solution to below the precipitation temperature. The polyamides are prepared by polycondensation of diamines with dicarboxylic acids. The precipitated polyamides obtained are used in layer-by-layer shaping processes such as selective laser sintering.
摘要:
A polyamide molding composition which can be used for production of a printable or printed item contains a) at most 90 parts by weight of a polyamide obtained from a lactam or from an amino carboxylic acid having at least 10 carbon atoms; and b) from 10 to 100 parts by weight of PA1010, wherein a total of components a) and b) is 100 parts by weight.
摘要:
Process for preparing ultrafine powders based on polyamides by contacting polyamides having a relative solution viscosity ηrel in the range from 1.5 to 2.0, measured in 0.5% m-cresol solution at 25° C., with an alcoholic medium in the presence of inorganic particles under the action of pressure and/or temperature to generate an at least partial solution, and then precipitating the polyamide from the at least partial solution, characterized in that a suspension of the inorganic particles suspended in the alcoholic medium is used. The resulting ultrafine polyamide powders have a specific BET surface area in the range of 5-100 m2/g; a fineness d50 of less than 70 μm; an apparent density AD in the range from 250 to 1000 g/l; and a particle content of 0.1 to 80% by weight of inorganic particles based on the total weight of the polyamide powder. They are equally suitable for coatings and for moldings and components with improved mechanical properties.
摘要:
The present invention relates to compositions for producing membranes, the compositions comprising at least 0.1% by weight of highly branched polymer, at least 0.5% by weight of linear polymer and at least 30% by weight of solvent. The present invention additionally describes membranes obtainable from the compositions, and methods of producing these membranes.
摘要:
A molding compound, containing at least 30% by weight of a copolyamide, which is derived from the following monomers: a) 50 to 95 mole percent of the combination of a diamine, selected from the group consisting of 1,9-nonane diamine, 1,10-decane diamine, 1,11-undecane diamine and 1,12-dodecane diamine, and terephthalic acid, and b) 5 to 50 mole percent of the combination of a diamine, selected from the group consisting of 2,2,4-trimethylhexamethylene diamine, 2,4,4-trimethylhexamethylene diamine, and mixtures thereof, and terephthalic acid. The copolyamide is crystalline and has low water absorption.