CS215440B1 - A method for preparing polyamide-6, antistatically modified - Google Patents

Abstract

A method of preparing antistatically modified polyamide-6 by adding a liquid polyetheramide concentrate to epsilon-caprolactam before its hydrolytic polymerization in an amount corresponding to an addition of 1 to 5% by weight. of its main reactant, i.e. diaminopolyethylene glycol per monomer weight, while the polyetheramide liquid concentrate is a dispersion mixture of 30 to 60% wt. of polyetheramide and 40 to 70% wt. polar solvents, preferably water, ethylene glycol, its oligomers or their mixture.

Description

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It is an object of the present invention to provide an antistatic modified polyamide-6.

The antistatic modification of polyamides and polyamide products to improve their physiological properties is most commonly attributed to the addition of! of various substances in which polyglycols or derivatives thereof appear as a physical or chemical component.

This category of modifiers includes inter alia polyetheramides. These have good antistatic effects and good resistance to scrubbing. However, the processes described to date for the preparation of modified polyamides and polyamide products, in particular fibers containing these modifiers, are associated with a number of incompletely solved technical problems.

The polyether amide modifiers can be incorporated into the polymer by mixing the modifier and polymer melts at temperatures above the melting point of both components, or by first preparing a mechanical mixture of these components in powder or granular form and melting them and homogenizing them in a suitable apparatus.

In particular, the problems of the two processes are mainly due to the fact that the preparation of the modifiers in granular or powder form has not been satisfactorily mastered yet. The modifier is markedly non-crystalline or low-crystal with a relatively low molecular weight-1-mer. This results in a slow setting during cooling of the melt and a more or less sticky character. In addition, strong swelling or dissolution is caused by both water and organic solvents. In summary, modifying the granulation of the modifier prevents a successful solution.

On the other hand, the manipulation of the modifier in blocks or in transport compositions is particularly demanding in the case of a rebuilding, which is time-consuming and takes place at temperatures above 150 ° C where it is already necessary to operate in a protective inert atmosphere. An advantage is the process whereby the molten polycondensation modifier is fed and fed to the polymer without cooling. In such a case, however, a relatively demanding device is needed for transporting, maintaining and mixing the melt of the polymer modifier. This must be part of the modified polymer line.

However, this means that the production of the modifier in this process binds to the production of the polymer and the modifier; Alternatively, the addition of the polyethers described so far and the described processes to the monomer is also a satisfactory technical solution since the component with a higher melting point determines the mixing temperature.

However, these problems can be technically solved by using a polyether amide modifier treated with solvents and an elevated temperature such that the low or elevated temperature exits the liquid and the modified modifier is added to the polyamide-forming monomer.

It has been shown that antistatic polyamide-6 and modified fibers can be prepared by probing polyethers which are polycondensation products of diamine polyethylene glycol mixtures. molar mass of 600-2000, dicarboxylic acids containing 4-12 carbon atoms, or an ester thereof in an amount of 1 - 1.2 equivalents to the diamino-polyethylene glycol used and the addition of other components such as carbon monoxide. ε-caprolactam or ε-aminocaproic acid, stabilizers, branching agents of the modifier of the modifier, and even in such an amount to give a weight of? the content of diamino-polyethylene glycol in the polyether amides was in the range of 50-92% in such a way that a liquid polyetheramide concentrate corresponding to the addition of 1-5% of its main reactant component by weight was added to the caprolactam by converting it to a weight, a dispersion mixture of 30-60% w / w polyether amide and 40-70% w / w polar solvents preferably water, ethylene glycol, its oligomers or mixtures thereof 1 The modifier is added to the mixture at normal or low elevated temperatures up to 120 ° The amount of addition of water or other solvents is also such that it does not interfere with the subsequent process of preparing the polymer, but it must suffice for the desired amount of modifier to be liquefied in. The advantage of the proposed process is the ability to work with the starting materials to prepare the modified polymer at their batches before the actual start of pol It is very simple and easy for the process to be carried out and for its equipment to be simplified and facilitated by the relatively low temperature conditions in which it is not necessary to work in a strictly inert atmosphere and in a closed system.

In addition, the safety of equipment operators is substantially increased. Liquidation of the modifier or its prepolycondensate, its transport and dosing can be carried out on a conventional attachment of polymetering devices, e.g., on a TiO2 suspension preparation and dispensing device, optionally in parallel with its preparation.

The amount of water for the preparation of the liquid modifier - to form it in a liquid form - may be less than or equal to that commonly used for the conventional seed for preparing a conventional polyamide. This means that the water required for the initiation of the polymerization can be introduced together with a modifier in which it has already performed the function of a scrubbing agent.

However, in addition to water, other solvents such as glycol and its oligomers or polyglycols can also be used. The process of liquefying the modifier - polyether amide can be accelerated by heating its mixture with the selected solvent. Due to the 1'-light

Claims (1)

It is preferred to use a modifier with a diamine polyglycol content above 55%. The proposed method of adding the modifier to the polymer can be carried out without new additional devices. The handling method can be selected so that the operator does not come into direct contact with the hot media. During the polymerization of caprolactam or other polyamide forming monomer, the present modifier does not substantially alter its chemical properties. However, it cannot be ruled out that preamidation reactions can be applied to a particular case in which an optional coupling of the molecule modifier to the polymer molecules can occur. However, this does not occur to such an extent that the extraneous mobility of a significant portion of the molecule modifier and its antistatic efficiency is reduced. Example 1 To a mixture of 2 kg of caprolactam and 4.4 g of benzoic acid was added 150 g of a liquid 40% w / w. polyetheramide concentrate in water. The mixture was polymerized at 254 ° C for 6 hours and then granulated. The granulated modified polymer after extraction of the monomer and drying of the object is a method of preparing polyamide-6, antistatic modified by the introduction of polyether amides, which are polycondensation products, mixtures of diamino-polyethylene glycol with relat. mol. a weight of 600-2000, dicarboxylic acids containing 4-12 carbon atoms or esters thereof in an amount of 1 - 1.2 equivalents to the diamino-polyethylene glycol used and addition of other ingredients such as ε-capro-lactam or ε-aminocaproic acid, stabilizers, agents causing branching the diffuser molecules i. in an amount such that the weight content of the diamino-polyethylene glycol in the polyether-215440 is spun at 275 ° C and a towing speed of 700 m / min through a 20-hole nozzle. Fibers of 1: 2.7 ratio had a strength of ,34.3 cN / dtex and a ductility of 29% and had antistatic properties. the charge and expressed in voltage (V) represented 26% of the value of the tension of the unmodified fibers. The used polyether amide concentrate is a dispersed polycondensate of a mixture of 65% diamino polyethylene glycol with a relative mole. weight of 1600, corresponding to 1.1 equivalents of adipic acid and the remainder to 100% of epsilon-caprolactam. Dispersion was carried out for four hours by boiling 40% of the mixture of polycondensate with water. Example 2 The procedure was identical to Example 1, except that the liquid polyether amide concentrate contained 5 wt. titanium dioxide. The resulting fiber properties were similar to Example 1. Example 3 The procedure was similar to Example 1, except that a mixture of 60% water and 40% diethylene glycol was used instead of water to prepare the polyether amide concentrate used. DISCLOSURE OF THE INVENTION ranges from 50-92%, characterized in that polyether amide concentrate is added to the ε-caprolactam prior to transferring its hydrolytic polymerization in an amount corresponding to the addition of 1-5% of its main reactant, ie diamine polyethylene glycol to the monomer, wherein the liquid polyether concentrate -Mid is a dispersion mixture of 30-60% wt. % polyether and 40-70% wt. polar solvents of water, ethylene glycol, its oligomer or mixtures thereof.