Method for preparing polyamide by anionic ring-opening copolymerization and polyamide prepared thereby

Patent metadata

Field	Value
Publication number	US-2022010065-A1
Application number	US-201917295832-A
Country	US
Kind code	A1
Filing date	Oct 31, 2019
Priority date	Dec 5, 2018
Publication date	Jan 13, 2022
Grant date	—

Abstract

The present invention relates to a method for preparing a polyamide by anionic ring-opening copolymerization in consideration of the reactivity between a monomer and an alkali metal-based initiator. The present invention relates to a method for preparing a polyamide by anionic ring-opening copolymerization and a polyamide prepared thereby, in which, by adding a metal hydride, which is an alkali metal-based initiator, to a lactam having higher reactivity therewith, a production rate of an anion-initiated monomer is increased, thus enabling polymerization with a high conversion rate within a short polymerization reaction time to obtain a polymer having a uniform molecular weight. In the method for preparing the polyamide by anionic ring-opening copolymerization (AROP), a metal hydride is added as an alkali metal-based initiator in an amount of 0.01-20 parts by weight based on 100 parts by weight of two or more lactams, and the alkali metal-based initiator is mixed with a lactam having higher reactivity among two lactams. Therefore, the metal hydride, which is the alkali metal-based initiator, is added to the monomer having high reactivity therewith to increase a production rate of an anion-initiated monomer and improve a conversion rate into a random copolymer.

First claim

1 . A method for preparing a polyamide by anionic ring-opening copolymerization (AROP), wherein a metal hydride is added as an alkali metal-based initiator in an amount of 0.01-20 parts by weight based on 100 parts by weight of two or more lactams, and the alkali metal-based initiator is mixed with a lactam having higher reactivity among two lactams.

2 . The method of claim 1 , wherein the two lactams have 3-12 carbon atoms constituting a lactam ring, or the 3-12 carbon atoms are substituted with an alkyl group.

3 . The method of claim 1 , wherein hydrogen generated after the alkali metal-based initiator is mixed with the lactam having higher reactivity among the two lactams is removed.

4 . The method of claim 1 , wherein the alkali metal-based initiator comprises a metal hydride, and the metal hydride comprises at least one selected from sodium hydride and potassium hydride.

5 . The method of claim 1 , wherein at least one selected from the group consisting of carbon dioxide (CO 2 ), benzoyl chloride, N-acetyl caprolactam, N-acetyl laurolactam, octadecyl isocyanate, toluene diisocyanate (TDI), and hexamethylene diisocyanate (HDI) is further added as an activator.

6 . The method of claim 5 , wherein an amount of the activator is in a range of 0.002-1.0 parts by weight.

7 . The method of claim 1 , wherein at least one selected from the group consisting of ethylene-bis-stearamide (EBS), an amine compound, a urea compound, and a di-urea compound is further added as a molecular weight controller.

8 . The method of claim 7 , wherein an amount of the molecular weight controller is in a range of 0.01-10 parts by weight.

9 . The method of claim 1 , wherein the lactam in the polymerization reaction has a conversion rate of 95% or more.

10 . The method of claim 1 , wherein the polymerization temperature is in a range of 160−300° C.

11 . A polyamide prepared by the method of claim 1 .

12 . The method of claim 11 , wherein the polyamide has a polydispersity index (PDI) of 1 to 4.

13 . The method of claim 11 , wherein the polyamide has at least one selected from a linear structure, a branched structure, a hyperbranched structure, and a dendritic structure.

Assignees

• Hanwha Solutions Corp

Inventors

• Kim Do Kyoung
• Lee Jin Seo
• Do Seung Hoe

Classifications

• C08G69/20 Primary

  characterised by the catalysts used · CPC title

• C08G69/18 Primary

  Anionic polymerisation · CPC title