METHOD FOR PRODUCING A POLYAMIDE

Abstract

A process for the production of a polyamide is disclosed. The process for production of a polyamide (P) comprises mixing a first mixture (M1), which comprises at least one lactam and at least one catalyst, with a second mixture (M2), which comprises at least one lactam, at least one activator and at least one amine, to give a polymerizable mixture (pM) and then polymerization of the polymerizable mixture (pM) to give the polyamide (P). A polyamide (P) obtainable by the process of the invention is also disclosed, as well as moldings made of the polyamide (P).

Claims

1. A process for the production of a polyamide (P), comprising the following steps: a) providing a first mixture (M1) which comprises the following components: (A) at least one lactam, and (B) at least one catalyst, b) providing a second mixture (M2) which comprises the following components: (A) at least one lactam, (C) at least one activator, and (D) at least one amine, c) mixing of the first mixture (M1) with the second mixture (M2) to give a polymerizable mixture (pM), and d) polymerization of the polymerizable mixture (pM) obtained in step c) to give the polyamide (P).

2. The process according to claim 1, wherein component (D) comprises at least one NH group or NH.sub.2 group.

3. The process according to claim 1 or 2, wherein component (D) is selected from the group consisting of primary aliphatic amines, primary cycloaliphatic amines, secondary aliphatic amines, secondary cycloaliphatic amines and secondary aromatic amines.

4. The process according to claim 1, wherein component (A) comprises at least one lactam having from 4 to 12 carbon atoms.

5. The process according to claim 1, wherein component (A) is selected from the group consisting of pyrrolidone, piperidone, -caprolactam, enantholactam, caprylolactam, capric lactam and laurolactam.

6. The process according to claim 1, wherein component (B) is selected from the group consisting of alkali metal lactamates, alkaline earth metal lactamates, alkali metals, alkaline earth metals, alkali metal hydrides, alkaline earth metal hydrides, alkali metal hydroxides, alkaline earth metal hydroxides, alkali metal alcoholates, alkaline earth metal alcoholates, alkali metal amides, alkaline earth metal amides, alkali metal oxides, alkaline earth metal oxides and organometallic compounds.

7. The process according to claim 1, wherein, in step c), the first mixture (M1) is mixed with the second mixture (M2) at a temperature in the range from 80 to 140 C.

8. The process according to claim 1, wherein component (C) is selected from N-substituted lactams, diisocyanates, polyisocyanates, allophanates and diacyl halides.

9. The process according to claim 1, wherein the polyamide (P) obtained in step d) additionally comprises from 1 to 50% by weight of at least one filler, based on a total weight of the polyamide (P).

10. The process according to claim 1, wherein the polymerizable mixture (pM) obtained in step c) comprises, based in each case on a total weight of the polymerizable mixture (pM), from 55 to 99.7% by weight of component (A), from 0.1 to 10% by weight of component (B), from 0.1 to 10% by weight of component (C) and from 0.1 to 25% by weight of component (D).

11. The process according to claim 2, wherein an amino functionality of component (D) is <10.

12. The process according to claim 1, wherein a molar mass of component (D) is <500 g/mol.

13. A polyamide (P) obtainable by a process according to claim 1.

14. A molding made of the polyamide (P) according to claim 13.

Description

EXAMPLES

[0168] The following components were used:

[0169] (A) Lactam [0170] Caprolactam (BASF SE, Ludwigshafen)

[0171] (B) Catalyst [0172] Brggolen C10 (17-19% by weight of sodium caprolactamate in caprolactam) (Brggemann KG, Heilbronn)

[0173] (C) Activator [0174] Brggolen C20 (80% by weight of hexamethylene-1,6-dicarbamoylcaprolactam in caprolactam) (Brggemann KG, Heilbronn)

[0175] (D) Additives [0176] Pyrazole 98% (abcr GmbH & Co. KG, Karlsruhe) [0177] Imidazole 99% (Merck KGaA, Darmstadt) [0178] 1-Octadecylamine 98% (abcr GmbH & Co. KG, Karlsruhe) [0179] 1,12-Diaminododecane 98% (Sigma-Aldrich, Taufkirchen) [0180] Piperidine 99% (Sigma-Aldrich, Taufkirchen) [0181] Dibutylamine 99.5% (Sigma-Aldrich, Taufkirchen) [0182] 1-Methylpyrazole 97% (abcr GmbH & Co. KG, Karlsruhe) [0183] 1-Methylimidazole 99% (Merck KGaA, Darmstadt) [0184] 1,2-Dimethylimidazole 98% (abcr GmbH & Co. KG, Karlsruhe) [0185] Pyridine 99.5% (Carl Roth GmbH+Co. KG, Karlsruhe) [0186] N,N-Dimethylaminopyridine (DMAP) (Sigma-Aldrich, Taufkirchen) [0187] N,N-Dimethylaniline 99% (Acros, Nidderau)

[0188] All components were weighed into the system under nitrogen and prepared for the polymerization. The reaction vessel, a 100 mL glass calorimeter reactor, was sealed with a grease-free Teflon stopper and equipped with a thermocouple. The polymerization reactions took place with stirring under dry nitrogen at 140 C. One temperature measurement per second was recorded here, and these measurements were used to generate the respective temperature-time graph of the reaction.

Comparative Example 1

[0189] 9.4 g of caprolactam were heated to 140 C. 0.4 g (4% by weight, 0.6 mol %) of catalyst (Brggolen C10) was added and the mixture was again heated to reach the reaction temperature, and then the polymerization was started by adding 0.2 g (2% by weight, 0.5 mol %) of activator (Brggolen C20). After 15 min, the anionic polymerization was quenched by cooling of the reaction vessel in ice/water (0 C.).

Comparative Example 2

[0190] Comparative example 1 was repeated, except that 9.325 g of caprolactam and 0.075 g (0.75% by weight, 1.0 mol %) of 1-methylimidazole were used.

Comparative Example 3

[0191] Comparative example 1 was repeated, except that 9.315 g of caprolactam and 0.085 g (0.85% by weight, 1.0 mol %) of 1,2-dimethylimidazole were used.

Comparative Example 4

[0192] Comparative example 1 was repeated, except that 9.325 g of caprolactam and 0.075 g (0.75% by weight, 1.0 mol %) of 1-methylpyrazole were used.

Comparative Example 5

[0193] Comparative example 1 was repeated, except that 9.33 g of caprolactam and 0.07 g (0.7% by weight, 1.0 mol %) of pyridine were used.

Comparative Example 6

[0194] Comparative example 1 was repeated, except that 9.29 g of caprolactam and 0.11 g (1.1% by weight, 1.0 mol %) of DMAP were used.

Comparative Example 7

[0195] Comparative example 1 was repeated, except that 9.29 g of caprolactam and 0.11 g (1.1% by weight, 1.0 mol %) of N,N-dimethylaniline were used.

[0196] For comparative examples 1 to 7, table 1 shows the induction period (t.sub.induction) and the maximal temperature T.sub.max reached after the period t.sub.max.

TABLE-US-00001 TABLE 1 Comparative t.sub.Induction t.sub.max T.sub.max example Amine [min] [min] [ C.] 1 0 1.0 186.6 2 1-Methylimidazole 0 1.0 179.2 3 1,2-Dimethylimidazole 0 1.2 175.5 4 1-Methylpyrazole 0 1.1 175.6 5 Pyridine 0 1.0 182.7 6 DMAP 0 1.2 183.4 7 N,N-Dimethylaniline 0 1.1 183.6

Inventive Example 8

[0197] 9.39 g of caprolactam and 0.01 g (0.1% by weight, 0.2 mol %) of imidazole were heated to 140 C. 0.2 g (2% by weight, 0.5 mol %) of activator (Brggolen C20) was added and the mixture was again heated to reach the reaction temperature, and then the polymerization was started by adding 0.4 g (4% by weight, 0.6 mol %) of catalyst (Brggolen C10). After cooling to final temperature (45 min), the anionic polymerization was quenched by cooling of the reaction vessel in ice/water (0 C.).

Inventive Example 9

[0198] Inventive example 8 was repeated, except that 9.225 g of caprolactam and 0.175 g (1.75% by weight, 0.75 mol %) of 4-octadecylamine were used.

Inventive Example 10

[0199] Inventive example 8 was repeated, except that 9.313 g of caprolactam and 0.087 g (0.87% by weight, 0.5 mol %) of 1,12-diaminododecane were used.

Inventive Example 11

[0200] Inventive example 8 was repeated, except that 9.344 g of caprolactam and 0.056 g (0.56% by weight, 0.75 mol %) of piperdine were used.

Inventive Example 12

[0201] Inventive example 8 was repeated, except that 9.315 g of caprolactam and 0.085 g (0.85% by weight, 0.75 mol %) of dibutylamine were used.

Inventive Example 13

[0202] Caprolactam and pyrazole were heated to 140 C. 0.2 g (2% by weight, 0.5 mol %) of activator (Brggolen C20) was added and the mixture was again heated to reach the reaction temperature, and then the polymerization was started by adding 0.4 g (4% by weight, 0.6 mol %) of catalyst (Brggolen C10). After cooling to final temperature (45 min), the anionic polymerization was quenched by cooling of the reaction vessel in ice/water (0 C.).

[0203] Table 2 shows the quantities used of caprolactam and pyrazole.

TABLE-US-00002 TABLE 2 Inv. Caprolactam Pyrazole Pyrazole Pyrazole ex. [g] [g] [% by wt.] [mol %] 13a 9.37 0.03 0.3 0.5 13b 9.365 0.036 0.36 0.6 13c 9.358 0.042 0.42 0.7 13d 9.35 0.05 0.48 0.8 13e 9.345 0.055 0.55 0.9 13f 9.34 0.06 0.6 1.0 13g 9.33 0.07 0.7 1.2 13h 9.325 0.075 0.75 1.3

Inventive Example 14

[0204] 9.34 g of caprolactam, 0.06 g (0.6% by weight, 1.0 mol %) of pyrazole and 0.2 g (2% by weight, 0.5 mol %) of activator (Brggolen C20) were weighed into the reaction vessel and securely sealed by means of a silicone septum. The mixture was heated to 140 C. for x min (x=0, 5, 15, 22.5, 30, 60) and the septum was then quickly replaced by the Teflon stopper with thermocouple. The polymerization was started by adding 0.4 g (4% by weight, 0.6 mol %) of catalyst (Brggolen C10), and after cooling to final temperature (45 min) was quenched by cooling of the reaction vessel in ice/water (0 C.).

[0205] For inventive examples 8 to 14, table 3 shows the induction period (t.sub.induction) and the maximal temperature T.sub.max reached after the period t.sub.max.

TABLE-US-00003 TABLE 3 Inv. t.sub.Induction t.sub.max T.sub.max ex. Amine [min] [min] [ C.] 8 Imidazole, 0.2 mol % 2.4 6.7 170.5 9 1-Octadecylamine, 0.75 mol % 5.5 16.2 150.7 10 1,12-Diaminododecane, 0.5 mol % 12 19.8 146.6 11 Piperidine, 0.75 mol % 3.8 7.6 180.7 12 0.75 mol % of dibutylamine 2.6 6.7 185.1 13a 0.5 mol % of pyrazole 3.4 6.6 177.3 13b 0.6 mol % of pyrazole 3.7 7.4 172.9 13c 0.7 mol % of pyrazole 7.0 14.0 163.0 13d 0.8 mol % of pyrazole 7.3 12.8 172.1 13e 0.9 mol % of pyrazole 7.3 14.8 164.3 13f 1.0 mol % of pyrazole 7.1 12.6 171.3 13g 1.2 mol % of pyrazole 9.7 18.8 165.5 13h 1.3 mol % of pyrazole 10.7 17.8 161.2 14a 1.0 mol % of pyrazole, x = 0 7.1 12.6 171.3 14b 1.0 mol % of pyrazole, x = 5 7.5 12.5 170.7 14c 1.0 mol % of pyrazole, x = 15 7.8 13.7 168.4 14d 1.0 mol % of pyrazole, x = 22.5 7.8 13.1 172.5 14e 1.0 mol % of pyrazole, x = 30 6.0 9.7 167.0 14f 1.0 mol % of pyrazole, x = 60 7.8 13.0 172.0

Inventive Example 15

[0206] 9.325 g of caprolactam and 0.075 g (0.75% by weight, 1.3 mol %) of pyrazole were heated to 140 C. 0.2 g (2% by weight, 0.5 mol %) of activator (Brggolen C20) was added and the mixture was again heated to reach the reaction temperature, and then the polymerization was started by adding 0.4 g (4% by weight, 0.6 mol %) of catalyst (Brggolen C10). After 45 min, the anionic polymerization was quenched by cooling of the reaction vessel in ice/water (0 C.). The maximal temperature T.sub.max is 171.5 C., and the proportion of unreacted component (A) (caprolactam) is 5.74% by weight.

Comparative Example 16

[0207] 9.325 g of caprolactam and 0.075 g (0.75% by weight, 1.3 mol %) of pyrazole were heated to 140 C. 0.4 g (4% by weight, 0.6 mol %) of catalyst (Brggolen C10) was added and the mixture was again heated to reach the reaction temperature, and then the polymerization was started by adding 0.2 g (2% by weight, 0.5 mol %) of activator (Brggolen C20). After 45 min, the anionic polymerization was quenched by cooling of the reaction vessel in ice/water (0 C.). The maximal temperature T.sub.max is 151.0 C., and the proportion of unreacted component (A) (caprolactam) is 14.98% by weight.

[0208] The temperature-time graph for inventive example 15 (continuous line) and comparative example 16 (broken line) can be seen in FIG. 2. The time tin seconds (s) is plotted on the x-axis, and the temperature T in C. is plotted on the y-axis. It can be seen that the period for which the polymerization is retarded in inventive example 15 is similar to that in comparative example 16. However, progress of the reaction after the induction period is significantly faster and more complete in inventive example 15 than in comparative example 16. The faster reaction can be seen from the steeper rise of the curve to the maximal temperature T.sub.max.

[0209] From comparison of inventive example 15 with comparative example 16 it can moreover be seen that a significantly smaller proportion of unreacted component (A) in the resultant polyamide (P) is achieved with the process of the invention.