Abstract:
The present invention relates to a process for preparing an aliphatic or semiaromatic polyamide oligomer, in which an aqueous composition of the monomers is subjected to an oligomerization at elevated temperature and elevated pressure and the oligomerization output is preferably subjected to an expansion.
Abstract:
The present invention relates to a process for producing polyamide moldings by subjecting a lactam-containing polymerizable composition to a rotomolding process.
Abstract:
The present invention relates to a process for producing a polymer film (P) comprising a polyamide composition (PC) by extruding the polyamide composition (PC) through an annular die and then stretching the tube thus obtained by blowing in air. The present invention further relates to the polymer film (P) obtainable by the process of the invention and to a process for packaging foodstuffs with the polymer film (P).
Abstract:
The invention relates to a device for synthesizing a polymer accompanied by separating a gaseous substance. Said device comprises: a reactor chamber (1) having a substantially circular cylinder-shaped upper section (11), which is delimited by two circular surfaces (111, 112) and a circumferential surface (113) and has a longitudinal cylinder axis, and a lower section (12), the upper section (11) and the lower section (12) being connected to one another via the first circular surface (111); an inlet opening (2); a first outlet opening (3), which is arranged in a wall of the lower section (12); a second outlet opening (4), which is arranged in the second circular surface (112) or in the circumferential surface (113) between the inlet opening (2) and the second circular surface (112); and a removal device (51), which is arranged so as to be movable along the longitudinal cylinder axis at least between the second circular surface (112) and the inlet opening (2), and contacts the circumferential surface (113). The invention further relates to a method comprising: feeding an oligomer melt (7) into a circular cylinder-shaped first section (11) of a reaction chamber (1) through an inlet opening (2) tangentially to a circumferential surface (113) of the first section (11); polymerizing the oligomer melt (7) to form a polymer melt (8); removing the polymer melt (8) from the reaction chamber (1) through a first outlet opening (3) of the reaction chamber (1); and removing a gaseous substance (9) from the reaction chamber (1) through a second outlet opening (4) of the reaction chamber (1) above the inlet opening (2). Deposits on at least one inner wall of the first section (11) of the reaction chamber (1) above the inlet opening (2) are removed by a removal device (51).
Abstract:
The invention relates to a process for continuously preparing polyamide oligomers. This comprises continuous conveying of an aqueous solution of polyamide-forming monomers from a reservoir vessel into an oligomerization reactor, heating of the aqueous solution beyond a dissolution or storage temperature, the residence time of the monomer solution in the oligomerization reactor being limited and the pressure or the partial vapor pressure of the water being adjusted such that a conversion of monomers to polyamide oligomers does not exceed a maximum value and/or the polyamide oligomers formed do not phase-separate or spontaneously crystallize in solid form, and continuous discharge of the polyamide oligomers from the oligomerization reactor. A polyamide oligomer preparable by this process can be provided continuously in a mixture with water in a process for preparing a semicrystalline or amorphous, thermoplastically processible polyamide and then postcondensed to give a polyamide. This polyamide can be used for production of moldings by means of injection molding, multicomponent injection molding, injection molding/welding, extrusion, coextrusion, blow molding or thermoforming.
Abstract:
The invention relates to a device for synthesizing a polymer accompanied by separating a gaseous substance. Said device comprises: a reactor chamber (1) having a substantially circular cylinder-shaped upper section (11), which is delimited by two circular surfaces (111, 112) and a circumferential surface (113) and has a longitudinal cylinder axis, and a lower section (12), the upper section (11) and the lower section (12) being connected to one another via the first circular surface (111); an inlet opening (2); a first outlet opening (3), which is arranged in a wall of the lower section (12); a second outlet opening (4), which is arranged in the second circular surface (112) or in the circumferential surface (113) between the inlet opening (2) and the second circular surface (112); and a removal device (51), which is arranged so as to be movable along the longitudinal cylinder axis at least between the second circular surface (112) and the inlet opening (2), and contacts the circumferential surface (113). The invention further relates to a method comprising: feeding an oligomer melt (7) into a circular cylinder-shaped first section (11) of a reaction chamber (1) through an inlet opening (2) tangentially to a circumferential surface (113) of the first section (11); polymerizing the oligomer melt (7) to form a polymer melt (8); removing the polymer melt (8) from the reaction chamber (1) through a first outlet opening (3) of the reaction chamber (1); and removing a gaseous substance (9) from the reaction chamber (1) through a second outlet opening (4) of the reaction chamber (1) above the inlet opening (2). Deposits on at least one inner wall of the first section (11) of the reaction chamber (1) above the inlet opening (2) are removed by a removal device (51).
Abstract:
The present invention relates to a process for preparing polyamides by hydrolytic polymerization, in which the polyimide is treated in a devolatilizing apparatus after the hydrolytic polymerization.
Abstract:
The present invention relates to a process for preparing an aliphatic or semiaromatic polyamide oligomer, in which an aqueous composition of the monomers is subjected to an oligomerization at elevated temperature and elevated pressure and the oligomerization output is preferably subjected to an expansion.