Method for increasing the difference between the melting temperature and the crystallization temperature of a polyamide powder

Abstract

The present invention relates to a method for reducing the crystallization temperature an the melting temperature of a polyamide powder resulting from the polymerization of at least one predominant monomer, in which the reduction in the crystallization temperature is greater than the reduction in the melting temperature, said method comprising a step of polymerization of said at least one predominant monomer with at least one different minor comonomer polymerized according to the same polymerization process as said at least one predominant monomer, said at least one minor comonomer being chosen from aminocarboxylic acids, diamine/diacid pairs, lactams and/or lactones, and said at least one minor comonomer representing from 0.1% to 20% by weight of the total blend of said monomers(s) and comonomer(s), preferably from 0.5% to 15% by weight of said total blend, preferably from 1% to 10% by weight of said total blend.

1 - 7 . (canceled) 
     
     
         8 . A process for reducing the crystallization temperature and the melting temperature of a polyamide derived from the polymerization of at least one major monomer, said process comprising a step of polymerization of said at least one major monomer with at least one different minor comonomer polymerized according to the same polymerization process as said at least one major monomer, said at least one minor comonomer selected from the group consisting of 11-aminoundecanoic acid, lauryllactam, caprolactam, caprolactone, at least one diamine-diacid couples selected from the group consisting of: 6.6, 6.10, 6.11, 6.12, 6.14, 6.18, 10.10, 10.12, 10.14, 10.18 and 10.T, T being terephthalic acid, and mixtures thereof said at least one minor comonomer representing from 1% to 7% by mass of the total blend of said monomer(s) and comonomer(s), such that the reduction in the crystallization temperature is greater than the reduction in the melting temperature, relative to the crystallization temperature and the melting temperature of the polyamide obtained from the polymerization of said at least one major monomer. 
     
     
         9 . The process as claimed in  claim 8 , in which said step of polymerization is an anionic polymerization. 
     
     
         10 . The process as claimed in  claim 8 , in which said step of polymerization is a hydrolytic polycondensation. 
     
     
         11 . The process as claimed in  claim 8 , in which said at least one major monomer is selected from the group consisting of 11-aminoundecanoic acid, lactam 12,decanediamine-sebacic acid couple (10.10) and mixtures thereof. 
     
     
         12 . The process as claimed in claim  1 , further comprising, after said polymerization step, at least one step selected from the group consisting of: dissolution, precipitation, extrusion, atomization, spraying, cold nebulization, hot nebulization, milling, cryogenic milling, screening, viscosity raising, and combinations thereof. 
     
     
         13 . A copolyamide or copolyesteramide powder obtained from the polymerization of at least two different monomers polymerized according to the same polymerization process, at least one of the monomers being minor and selected from the group consisting of 11-aminoundecanoic acid, lauryllactam, caprolactam, caprolactone, and at least one diamine-diacid selected from the group consisting of 6.6, 6.10, 6.11, 6.12, 6.14, 6.18, 10.10, 10.12, 10.14, 10.18 and 10.T, T being terephthalic acid, said at least one minor monomers representing from 1% to 7% by mass of the total blend of said monomer(s). 
     
     
         14 . The powder as claimed in  claim 13 , comprising an 11-aminoundecanoic acid major monomer and at least one minor monomer selected from the group consisting of hexamethylenediamine-adipic acid couple (6.6), lauryllactam, caprolactam, caprolactone and mixtures thereof. 
     
     
         15 . The powder as claimed in  claim 13 , comprising a lauryllactam major monomer and a minor monomer selected from the group consisting of caprolactam, caprolactone, hexamethylenediamine-adipic acid couple (6.6) and mixtures thereof. 
     
     
         16 . (canceled) 
     
     
         17 . A process for manufacturing a polyamide article comprising melt-induced powder aggregation using electromagnetic radiation of a polyamide powder obtained from the polymerization of at least two different monomers polymerized according to the same polymerization process, at least one of the monomers being minor and selected from the group consisting of 11-aminoundecanoic acid, lauryllactam, caprolactam, caprolactone, and at least one diamine-diacid couple selected from the group consisting of 6.6, 6.10, 6.11, 6.12, 6.14, 6.18, 10.10, 10.12, 10.14, 10.18 and 10.T, T being terephthalic acid, said at least one minor monomers representing from 1% to 7% by mass of the total blend of said monomer(s). 
     
     
         18 . (canceled)