METHOD FOR PRODUCING COPOLYAMIDES Russian patent published in 2022 - IPC C08G69/16 C08G69/14 C08G69/26 

FIELD: polymers.

SUBSTANCE: present invention relates to a method for producing copolyamides. The method includes a stage (1) of mixing the reagents and melting the mixture while heating to the temperature of 80 to 100°C, followed by heating (stage (2)) the resulting melt to 170°C and conduction polycondensation in the melt. Both stages are executed while stirring in a nitrogen medium. At the stage (2), ultrasonic frequency oscillations with the intensity I₂ = (12÷30)∙10⁴ W/m² and the specific power W_sp.2=(25÷60)∙10³ W/m³ are applied to the melt. At the stage (1), ultrasonic frequency oscillations with the intensity I₁ = (1÷2)I₂ and the specific power W_sp.1=(1÷2)W_sp.2 are applied to the mixture. The composition of the reagents includes ε-caprolactam (ε-CL) in an amount of 50 to 60% and hexamethylene diammmonium adipinate (AH salt) in an amount of 40 to 50% taken from the total mass of ε-CL and AH salt, as well as a modifier in an amount of 0.5 to 2.0% and distilled water in an amount of 5 to 15% taken from the total mass of ε-CL and AH salt. The modifier constitutes a polymethylsiloxane liquid.

EFFECT: present invention provides high productivity for the target product due to the reduction in the duration of synthesis, as well as a high yield of the reaction due to the equilibrium being shifted towards polymer formation and improvement in the homogenisation of the melt.

4 cl, 1 tbl, 13 ex