JPS5840979B2 - Polyamide manufacturing method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a polyamide that has excellent mechanical properties such as tensile strength and bending strength, and has high elongation.

A method of polymerizing ε-caprolactam by the action of an alkaline catalyst and an activator, the so-called alkaline polymerization method, is known.

The polyamide obtained by this method has features such as higher tensile strength, flexural strength, tensile modulus of elasticity 1 flexural modulus, etc. compared to the polyamide obtained by polymerizing ε-kafoulakucum in the presence of water. However, the drawback is that the elongation is small.

In order to increase the elongation of polyamide obtained by alkaline polymerization of ε-caprolactam, a method has been proposed in which ε-caprolactam is copolymerized with ω-laurinlactam in an alkaline manner (see Japanese Patent Publication No. 4313754).

According to this method, the elongation of the polyamide obtained is increased, but there is a drawback that the tensile strength, bending strength, etc. of the boamide are decreased.

An object of the present invention is to provide a method for producing polyamide with high elongation and excellent mechanical properties.

The object of this invention is to prepare ε-caprolactam and ω-laurinlactam in an amount of 1 to 15% by weight relative to ε-caprolactam in the presence of polyvinylpyrrolidone in an amount of 0.5 to 10% by weight relative to the total lactam, an alkaline catalyst and It is distantly related to copolymerization by the action of an activator.

Preferably, the ε-caprolactam and ω-laurinlactam used in this invention are substantially anhydrous.

The amount of ω-laurinlactam used is 1 to 15% by weight, preferably 1 to 10% by weight based on ε-caprolactam.
It is.

If the amount of ω-laurinlactam used is smaller than the above lower limit, it will not be possible to obtain a polyamide with high elongation, and if the amount of ω-laurinlactam used is larger than the above upper limit, the tensile strength and bending strength of the obtained polyamide will decrease. etc. will decrease.

The number average molecular weight of the polyvinylpyrrolidone used in this invention is usually 1,000 to 100,000°, preferably io, ooo to 50,000.

The amount of polyvinylpyrrolidone used is 0.5 with respect to the total amount of ε-caprolactam and ω-laurinlactam.
-10% by weight, preferably 1-5% by weight.

If the amount of polyvinylpyrrolidone used is less than the above lower limit, the tensile strength, bending strength, etc. of the obtained polyamide will decrease, and if the amount of polyvinylpyrrolidone used is larger than the above upper limit, polyvinylpyrrolidone will bleed on the surface of the obtained polyamide. The tensile strength and bending strength of polyamide decrease.

As the alkali catalyst in this invention, all catalysts used in the known alkaline polymerization method of ε-caprolactam can be used, and specific examples thereof include alkali metals, alkaline earth metals, hydrides thereof, and water. Oxides, oxides, carbonates, Alcolade, Grignard reagents, aluminum hydride compounds, these compounds and ε-
Examples include reaction products with caprolactam or ω-laurinlactam.

As the activator in this invention, all the activators used in the known alkaline polymerization method of ε-caprolactam can be used, and specific examples thereof include N-acyllactam, organic isocyanate, acid chloride, Examples include acid anhydrides, esters, urea derivatives, carbodiimides, and ketenes.

The amounts of alkaline catalyst and activator used are ε-
It is usually 0.01 to 5 mol% based on the total amount of caprolactam and ω-laurinlactam.

The copolymerization of ε-caprolactam and ω-laurinlactam is carried out at a temperature higher than the melting point of ε-caprolactam and lower than the melting point of the resulting polyamide, preferably 120 to 1
It is carried out at a temperature of 80°C.

In this invention, the copolymerization reaction can also be carried out in the presence of colorants, reinforcing agents, fillers, etc. that do not substantially inhibit the copolymerization reaction.

According to the present invention, as can be seen from the results of Examples described below, it is possible to produce a polyamide that has excellent tensile strength, tensile modulus, bending strength, and bending modulus, and has high elongation.

Next, Examples and Comparative Examples will be shown.

In the Examples and Comparative Examples, the tensile strength, tensile modulus, and elongation of the resulting polyamides were determined in accordance with ASTM D 63.
8, the flexural strength and flexural modulus of the obtained polyamide were each measured in an absolutely dry state according to ASTM D 790.

Example 1 3.5 kg of ε-caprolactam was placed in a 51 flask equipped with a stirrer, a conduit for nitrogen gas and a conduit to the reduction system.
, 105 g of ω-laurin lacum and number average molecular weight 3
70 g of 0.000% polyvinylpyrrolidone were added and melted at 120° C. with stirring.

Then, 8.5 g of sodium methylate was added to the flask, and the flask was maintained at 120° C. while passing a trace amount of nitrogen gas under reduced pressure to distill off the produced methyl alcohol.

After raising the temperature of the contents of the flask to 160°C and adding 6.0 g of polymethylene polyphenylisocyanate [manufactured by Kasei Upjohn ■, trade name: Papi] while stirring, the contents of the flask were immediately preheated to 160°C. Vertical 30
The mixture was supplied to a mold having a cavity of 0 mc, 300 mm in width, and 40 mm in depth, and kept at 160° C. for 2 hours to produce polyamide.

The obtained molded product was cut to produce a test piece, and its physical properties were measured.

The results are shown in Table 1. Comparative Example 1 A polyamide was produced in the same manner as in Example 1 except that polyvinylpyrrolidone was not used.

The physical properties of this polyamide are shown in Table 1.

Comparative Example 2 A polyamide was produced in the same manner as in Example 1, except that the amount of ω-laurinlactam used was changed to 175 g, and polyvinylpyrrolidone was not used.

The physical properties of this polyamide are shown in Table 1.

Example 2 A polyamide was produced in the same manner as in Example 1, except that the amount of polyvinylpyrrolidone used was changed to 105 g.

The physical properties of this polyamide are shown in Table 1.

Example 3 A polyamide was produced in the same manner as in Example 1, except that the amount of polyvinylpyrrolidone used was changed to 140 g.

The physical properties of this polyamide are shown in Table 1.

Claims (1)

[Claims] 1 ε-caprolactam and ω-laurinlactam in an amount of 1 to 15% by weight relative to ε-caprolactam in the presence of polyvinylpyrrolidone in an amount of 0.5 to 10% by weight relative to the total lactam, an alkaline catalyst and an activator. A method for producing polyamide characterized by copolymerization by action.