摘要:
The invention relates to a branched polyamide prepolymer obtained or obtainable by polymerization of a polyamide forming monomer mixture, comprising AA-BB repeat units and branching units derived from diamines (monomer A) dicarboxylic acids (monomer B), and/or a salt of A and B, and a higher functional monomer (monomer C) present in a molar amounts defined by formula I and formula II: MC=(Q/FC)*(MA+MB) (Formula I) and R=((MA*2)+(MC*FCA))/((MB*2)+(MC*FCB)) (Formula II) wherein—MA, MB and MC represent the molar amounts of repeat units derived from the monomers A, B and C, respectively;—FC represent the functionality of monomer C, and is equal to FC-A+FC-B;—FC-A is the number of the amino functional groups comprised by monomer C;—FC-B is the number of carboxyl functional groups or precursor groups thereof comprised by monomer C;—Q is a number in the range of 0.06-1.00; and—R is a number in the range of 0.7-1.3, which polyamide prepolymer has a viscosity number (VN), measured according to ISO 307, in the range of 7-30 mL/g. The invention also relates to a process for preparing a branched polyamide polymer, comprising (1) a melt-mixing step wherein an essentially linear polyamide (pre)polymer and a branched polyamide prepolymer are provided to and mixed and heated in a melt mixing apparatus, thereby forming a mixed melt, and the mixed melt being cooled, thereby forming a solid mixture; and (2) a solid state post condensation step wherein the solid mixture is post-condensed at elevated temperature in the solid state, thereby forming a high molecular weight branched polyamide polymer.
摘要:
The invention relates to a process for increasing the molecular weight of a polyamide via solid-state post-condensation by exposing the polyamide in the solid-state at elevated temperature to an inert gas atmosphere, that comprises a step (a) wherein the gas atmosphere to which the polyamide is exposed has a dew temperature Tdew-1, followed by a step (b) wherein the gas atmosphere to which the polyamide is exposed has a dew temperature Tdew-2, whereby Tdew-1 is higher than Tdew-2. The effect is that a high molecular weight polyamide can be obtained in a shorter production time.
摘要:
The invention relates to a semi-aromatic polyamide containing at least tetramethylene terephthalamide units and also hexamethylene terephthalamide units. The copolyamide has a melting point higher than approximately 290° C., a high crystallinity and a good stability. Preferably the copolyamide according to the invention contains approximately 30-75 mol % hexamethylene terephthalamide units and also approximately 0.01-20 mol % other units. The invention also relates to a process for the preparation of a semi-aromatic copolyamide containing at least tetramethylene terephthalamide units and hexamethylene terephthalamide units, characterized in that, successively, a first polymerization is effected in the melt phase, followed by an post-polymerization of the low molar mass polymer thus obtained in the solid phase; and to compositions and products that contain said copolyamide.
摘要:
The invention relates to a semi-aromatic polyamide, and a polyamide composition comprising the semi-aromatic polyamide, comprising a diamine component (a) comprising, based on the total number of moles of the diamine component (a): between 5 and 30 mole % of at least one C2-C5 diamine, between 5 and 30 mole % of at least one C7+ diamine, and between 45 and 90 mole % of a C6 diamine; and a dicaboxylic acid component (b) comprising, based on the total number of moles of the dicaboxylic acid component (b): at least 50 mole % of terephthalic acid and at most 50 mole % of another dicarboxylic acid.
摘要:
The invention relates to a semi-crystalline semi-aromatic polyamide comprising A-A-B-B units derived from (a) dicarboxylic acids consisting of a mixture of aromatic dicarboxylic acid and aliphatic dicarboxylic acid and (b) diamines consisting of a mixture of long chain aliphatic diamine and short chain aliphatic diamine, wherein (a-i) the aromatic dicarboxylic acid consists for at least 80 mole % of terephthalic acid, and (a-ii) the aliphatic dicarboxylic acid constitutes at least 5 mole % of the dicarboxylic acids, (b-i) the short chain aliphatic diamine constitutes at least 10 mole % of the diamines, and (c) the aromatic dicarboxylic acid and the long chain aliphatic diamine constitute 60-90 mole % of the total molar amount of dicarboxylic acids and diamines.
摘要:
The invention relates to a high molecular weight branched polyamide polymer comprising (a) blocks predominantly consisting of AA-BB repeat units, (b) blocks predominantly consisting of AB repeat units, and (c) branching units. The invention also relates to a process for the preparation of the high molecular weight branched polyamide polymer, comprising (1) a melt-mixing step wherein an essentially linear polyamide prepolymer (X-1), predominantly consisting of AA-BB repeat units, an essentially linear polyamide (pre)polymer (X-2), predominantly consisting of AB repeat units, and a branching agent are provided to and mixed and heated in a melt mixing apparatus, thereby forming a mixed melt, and the mixed melt being cooled, thereby forming a solid mixture; and (2) a solid state post condensation step wherein the solid mixture is post-condensed at elevated temperature in the solid state, thereby forming a high molecular weight branched polyamide polymer.
摘要:
This invention relates to a flame retardant polyamide composition comprising a semi-aromatic polyamide, a flame retardant system and a reinforcing agent, wherein the semi-aromatic polyamide comprises units derived from dicarboxylic acids comprising terephthalic acid and aliphatic dicarboxylic acids, and aliphatic diamines. In the semi-aromatic polyamide the aliphatic diamines consist of 10-70 mole % of a short chain aliphatic diamine with 2-5 C atoms and 30-90 mole % of a long chain aliphatic diamine with at least 6 C atoms; the dicarboxylic acids consist of 5-65 mole % aliphatic dicarboxylic acid and optionally aromatic dicarboxylic acid other than terephthalic acid and 35-95 mole % terephthalic acid; and the combined molar amount of terephthalic acid and the long chain aliphatic diamine is at least 60 mole %, relative to the total molar amount of the dicarboxylic acids and diamines. The invention also relates to a housing for an electrical/electronic (E/E) connector and use therein of the flame retardant polyamide composition, to a surface mounting process wherein the E/E connector is used and to a surface mounted device comprising the E/E connector.
摘要:
The invention relates to a semi-aromatic polyamide, and a polyamide composition comprising the semi-aromatic polyamide, comprising a diamine component (a) comprising, based on the total number of moles of the diamine component (a): between 5 and 30 mole % of at least one C2-C5 diamine, between 5 and 30 mole % of at least one C7+ diamine, and between 45 and 90 mole % of a C6 diamine; and a dicaboxylic acid component (b) comprising, based on the total number of moles of the dicaboxylic acid component (b): at least 50 mole % of terephthalic acid and at most 50 mole % of another dicarboxylic acid.
摘要:
The invention relates to a process for the preparation of polyamide nanofibers by electrospinning, wherein the process is a multi-nozzle electrospinning process with the use of a multi-nozzle device or a nozzle-free electrospinning with the use of nozzle free device, comprising steps wherein a high voltage is applied, a polymer solution comprising a polymer and a solvent is fed to the multi-nozzle device or the nozzle free device and transformed under the influence of the high voltage into charged jet streams the jet streams are deposited on a substrate or taken up by a collector, and the polymer in the jet streams solidifies thereby forming nanofibres, and wherein the polymer comprises a semi-crystalline polyamide having a C/N ratio of at most 5.5 and a weight average molecular weight (Mw) of at most 35,000. The invention also relates polyamide nanofibers made by the electrospinning process, as well as to products made thereof and use thereof.
摘要:
The present invention relates to a process for preparing an injection molded part, comprising the following steps: a preparing a glass fiber reinforced polyamide-6 composition with a relative viscosity of less than 2.4; b heating a such composition to obtain a viscous liquid; c filling a mold cavity with the viscous liquid with a filling time of at least 0.8 s; d leaving the viscous liquid in the mold under pressure until it cools to form a part; e opening the mold; f ejecting the part; wherein the polyamide-6 composition has a crystallization temperature under hyper DSC conditions of less than 168° C. The invention also relates to an injection molded part a having a maximum wall thickness of at least 2.5 mm; and/or b a part weight of at least 100 g per injection point; wherein the part consists of a glass fiber reinforced semi-crystalline polyamide-6 composition having a relative solution viscosity of less than 2.4, wherein the polyamide-6 composition has a crystallization temperature under hyper DSC conditions of less than 168° C.