Abstract:
The invention relates to a method for obtaining 3-aminomethyl-3,5,5-trimethyl cyclohexylamine (isophorone diamine, IPDA) with a cis/trans isomer ratio of at least 73/27 by fractional distillation. Said method comprises the following steps: a) preparation of IPDA with a cis/trans isomer ratio /=73/27 and iv) an IPDA fraction with a cis/trans isomer ratio
Abstract:
The invention relates to a method for the production of metylamines by means of gas phase reaction from methanol and ammonia as educts in the presence of a heterogeneous catalyst at a pressure in the region of 15 - 30 bars. Said educts are vaporised in one or several heat exchangers (1, 2, 3) in order to overheat an educt gas flow and are subsequently guided to a reactor (4). The educts can be mixed in the inlets of one of the heat exchangers (1, 2, 3) or at one remaining position in a heat exchanger (1, 2, 3). A product gas flow containing monomethylamine, dimethylamine and trimethylamine, in addition to reaction auxiliary products, is removed from the reactor (4). In order to regulate the reactor admission temperature of the educts to a temperature in the region of 360 DEG C - 370 DEG C, the educt gas flow or the product gas flow is guided partially or completely through an adjustable valve (5) enabling the pressure and the condensation temperature to be varied.
Abstract:
A process for preparing polyamides comprises polymerizing starting monomers or starting oligomers in the presence of at least one compound of the formula (I)whereR is a functional group R which bears 1-4 identical or different amide-forming groups R ,R is H, C1-C20-alkyl, cycloalkyl, benzyl or OR , where R is H, C1-C20-alkyl, cycloalkyl or benzyl,R , R , R and R are independently C1-C10-alkyl,n is a natural number greater than 1, andthe piperidine derivatives attached to R are identical or different with regard to the substituents, meaning R , R , R , R and R .The polyamides are useful for preparing filaments, fibers, films, sheetlike structures and moldings.
Abstract:
The invention relates to a method for producing polyamides, characterized in that the polymerization of starting monomers or starting oligomers is carried out in the presence of at least one compoundof formula where R is a functional group R8 which has 1 to 4 identical or different amide-forming groups R7; R1 is H, C1-C20 alkyl, cycloalkyl, benzyl, OR6 where R6 is H, C1-C20 alkyl, cycloalkyl, benzyl; R2, R3, R4, R5 independently of each other are C1-C10 alkyl; n is a natural number greater than 1, and the piperidine derivatives linked to R are identical to or different from the substituents,that is R1, R2, R3, R4 and R5. Said polyamides can be used to produce thread, fibres, films, flat structures and moulded bodies.
Abstract:
A PROCESS FOR PURIFYING CRUDE PIPERIDINES OF THE FORMULA I WHERE RL TO R4 ARE CI-C6-ALKYL, OR RL AND R2 AND/OR R3 AND R4 TOGETHER ARE A CH2-CHAIN OF 2 TO 5 CARBONS, WHICH COMPRISES, IN A FIRST STEP, REMOVING HIGH-BOILING SUBSTANCES AND, IF PRESENT, WATER FROM THE CRUDE PIPERIDINES BY DISTILLATION; IN A SECOND STEP, ADDING FROM 0.01 TO 5 % BY WEIGHT, BASED ON THE PRODUCT OF THE FIRST STEP, AS A REDUCING AGENT; AND, IN A THIRD STEP, ISOLATING THE PIPERIDINES BY DISTILLATION.
Abstract:
A process for reducing the dimerisation of piperidine of formula (I) in which R1 to R4 are C1 to C6 alkyl, R1 and R2 and/or R3 and R4 together are a CH2 chain with 2 to 5 C atoms. Said process is characterised in that to the piperidine is added 0.001 to 0.2 wt% of a reducing agent of the formula MXH4-m Y m, in which M is an alkaline metal, NR4, where R are the same or different C1-C4 alkyl groups, or an equivalent of an alkaline earth metal or an equivalent zinc, X is boron or aluminium, Y is H or CN and m is 0 or 1. Also described is a mixture of piperidine (I), 0.001 to 0.2 wt% of a reducing agent and 1 to 1000 ppm of the dimer of the piperidine (I), and the production of HALS stabilisers therefrom.
Abstract:
Recovery of isophoronediamine (IPDA) comprises preparation of IPDA having a cis/trans isomer ratio of less than 73/27 and separation into at least 5 fractions by distillation including an IPDA fraction having a cis/trans ratio of greater than 73/27 and a fraction having a cis/trans ratio of less than 66/34. A process for the recovery of 3-aminomethyl-3,5,5-trimethylcyclohexylamine (isophoronediamine, IPDA) comprises; (a) preparation of IPDA having a cis/trans isomer ratio of less than 73/27; (b) introduction of IPDA to the middle region of a distillation column having inserts and distillation of IPDA at 5-300 degreesC and 10-2000 mbar; (c) optionally further purification of the IPDA from (b) by distillation in at least one further column whereby the IPDA from step (b) and (c) are separated into at least 5 fractions comprising an organic fraction (1a) containing impurities having a lower b. pt. than trans-IPDA, an aqueous fraction (1b) containing impurities having a lower b. pt. than trans-IPDA, a fraction (2) containing impurities having a higher b. pt. than cis-IPDA, an IPDA fraction (3) having a cis/trans ratio of greater than 73/27 and an IPDA fraction (4) having a cis/trans ratio of less than 66/34.
Abstract:
An inherently light- and heat-stabilized polyamide is prepared by polymerizing polyamide forming monomers in the presence of (a) an effective amount of at least one piperidine derivative of the general formula I: wherein Ri1 represents hydrogen, benzyl, or a alkyl containing 1 to 20 carbon atoms; Ri2 through Ri5 denote each hydrogen or the same or a different alkyl having 1 to 6 carbon atoms; X has n free valance bonding sites and represents an alkyl or substituted alkylene having from about 1 to about 30 carbon atoms or an arylene having from about 1 to about 20 carbon atoms w; m is 0 or 1; -C(O)-Ri6 represents a group that can form an amide bond together with an amine, and n is equal to 1, 2 or 3 and (b) an effective amount of at least one 4-amino-2,2,6,6-tetramethylpiperidine derivative of the general formula II: wherein Ri7 denotes hydrogen, benzyl, or a alkyl containing 1 to 20 carbon atoms. The inherently light- an heat-stabilized polyamide may be used to form articles such as, for example, fibers, carpets, yarns, and textile fabrics.
Abstract:
A process for preparing polyamides comprises polymerizing starting monomers or starting oligomers in the presence of at least one compound of the formula (I)whereR is a functional group R which bears 1-4 identical or different amide-forming groups R ,R is H, C1-C20-alkyl, cycloalkyl, benzyl or OR , where R is H, C1-C20-alkyl, cycloalkyl or benzyl,R , R , R and R are independently C1-C10-alkyl,n is a natural number greater than 1, andthe piperidine derivatives attached to R are identical or different with regard to the substituents, meaning R , R , R , R and R .The polyamides are useful for preparing filaments, fibers, films, sheetlike structures and moldings.
Abstract:
A process for preparing polyamides comprises polymerizing starting monomers or starting oligomers in the presence of at least one compound of the formula (I)whereR is a functional group R which bears 1-4 identical or different amide-forming groups R ,R is H, C1-C20-alkyl, cycloalkyl, benzyl or OR , where R is H, C1-C20-alkyl, cycloalkyl or benzyl,R , R , R and R are independently C1-C10-alkyl,n is a natural number greater than 1, andthe piperidine derivatives attached to R are identical or different with regard to the substituents, meaning R , R , R , R and R .The polyamides are useful for preparing filaments, fibers, films, sheetlike structures and moldings.