CS215647B1 - Process for the polymerization and copolymerization of lactam lactamacids - Google Patents

Abstract

The invention relates to a method for preparing polyamides by polymerization or copolymerization of lactams of 1-amino acids of the general formula CO-(CH2)X-NH, where x is 5 to 11. The essence of the invention is that the polymerization or copolymerization is carried out in the presence of an initiator, which is an organic diacid containing a sulfo group, of the general formula MO.jS jch2)-cooh L (GH2)y-C0OH , where M is an alkali metal and y is 0 to 5. The initiator is used in a concentration of 0.1 to 5 mol %. The invention can be used, for example, in the production of polyamide fibers with improved dyeability.

Description

This invention relates to the preparation of polyamides containing sulfonic acid groups by polymerization or copolymerization of lactams ^ / - amino acid of the formula 00- (0Η _{2) χ -ΝΗ} wherein x is 5-11,

Sulfo-containing polyamides are usually prepared by polymerizing lactams or by polycondensation of diacid salts with diamines, in the presence of aromatic diacids containing a bonded sulfoacid or an alkali and calcium salt thereof on the benzene ring, and simultaneously in the presence of diamines. Often a salt of a diamine and a sulfoacid is prepared first and then used for copolycondensation, for example according to Japanese Pat. No. 76,233.20. In Japanese Pat. No. 78 142499, the preparation of a hydrolytic polyamide 6 wherein the initiator is water and acetic acid in the presence of sodium sulfoisophthalic acid is protected.

The invention solves a method of preparation of the polyamides containing sulfonic acid groups by polymerization or copolymerization of lactams of formula 00- (0Η _{2) χ -ΝΗ,} where x is 5-11 »The essence of the invention is that the initiator used is an organic diacid containing sulfo groups of the formula

where M is an alkali metal and y is 0 to 5, preferably the citrate is used in a concentration of 0.1 to 5 mol%.

(CH ₂ ) _y -COOH (CH ₂ ) _y -COOH, sodium 5-sulfoisophthalic acid. The polymerization is conducted at a temperature of 220 to 220 ° C

320 ° C.

The resulting polyamide is terminated with carboxyl groups and contains one sulfo group in each chain,

C 0 -NH 0 OH

HOOC— / vvvvvvvvvvvvvvvv ^ tvMax — ijh — CO - * - rj J

SO-jM

The polymerization degree is dependent on the amount of initiator added and decreases with increasing concentration. The fiber-forming type of polyamide can only be prepared up to the initiator concentrations of 1 mol%, at higher initiator concentrations already low viscosity polymers are formed. However, these products can be used in addition to fiber forming polyamides before or after polymerization.

At an initiator concentration of more than 5 mol%, completely homogeneous products can no longer be obtained, since the initiator is only slightly soluble in the molten lactams and in the polymerization mixture.

The polymerization temperature of this process, which has the character of cationic polymerization, is the same as that of the hydrolysis process, i.e. 220 to 32 ° C, depending on the type of lactams used.

The polymerization rate is only slightly lower than that of the hydrolytic polymerization initiated by a similar concentration of the respective aminokysel-amino acid.

The preparation method according to the invention is described in more detail in the following examples.

Example 1

To the dried 6-caprolactam (2.9647 g) was added 0.0353 g (i.e. 0.5 mol%) of 5-sulfoisophthalic acid sodium salt and the mixture polymerized in an evacuated sealed glass vial at 260 ° C. After 48 hours of polymerization, 75% of the polymer (after extraction of the product with water) was obtained at a polymerization stage of 70. The equilibrium polymer at polymerization stage 190 was also obtained.

after 75 hours of polymerization.

Example 2

The polymerization was carried out as in Example 1 except that the initiation was 2 mol% sodium 5-sulfoisophthalic acid. The equilibrium polymer was obtained after 40 hours of polymerization at 260 ° C. The degree of polymerization P = 52 was calculated from both viscosimetric measurements, the determination of terminal carboxyl groups, and the determined sulfur content and elemental analysis.

Example 3

Anhydrous 8-octalactam was polymerized at 25 ° C in the presence of 5 mol% of 5-sulfoisophthalic acid, sodium salt, as described in Example 1. Equilibrium polymer (94 °) with a polymerization degree of 28 (viscosimetric), 25 (end groups) and . 30 (from elemental analysis) was obtained after 8 hours of polymerization.

Example 4

Anhydrous 12-dodecanlactam was polymerized at 300 ° C in the presence of 1 mole X of 5-sulfoisophthalic acid sodium salt for 12 hours as described in Example 1. 98% polymer with a polymerization degree of 98 was obtained.

Example 5

The equimolar mixture of 6-caprolactam and 12-dodecanlactam was polymerized at 260 ° C in the presence of 2 mol% sodium 5-sulfoisophthalic acid for 100 hours as described in Example 1. Copolymer having an intrinsic viscosity ('Z) = 0.4 (m) -cresol, 25 ° C) was obtained in 94% yield.

Claims (1)

SUBJECT OF THE INVENTION 1. A method for the polymerization and copolymerization of Cp-amino acid lactams of the general formula (CO-(CH ₉ ) where x is 5 to 11, characterized in that an organic diacid containing a sulfo group of the general formula, (CH ₂ ) y - COOH (CH ₂ ) y - COOH is used as the initiator where M is an alkali metal and y is 0 to 5, temperatures 220 to 320°C. 2. Method according to point 1, marked by that, that 3. Method according to point 1, marked by that, that 5-sulfoisophthalic. suction is performed by the