Production of polyamide powders by ester aminolysis

Abstract

A method for producing a polycondensate powder dispersion, wherein the method includes at least one step of polycondensation: i) of at least one diester and at least one diamine, and/or ii) at least one amino ester, while stirring, in a solvent that can solubilize both the diamine and the diester and/or the amino ester but not the polyamide that forms during the polycondensation, at a temperature between 30° C. and the boiling temperature of the solvent, in order to produce a powder precipitate dispersed in the solvent.

1 . A polycondensate powder obtained from a process comprising a polycondensation of:
 i) at least one diester and at least one diamine,   and/or   ii) at least one amino ester   wherein the polycondensation is performed in a solvent that can dissolve both the diamine and the diester and/or the amino ester, but not a polyamide which forms during the polycondensation, such that a polycondensate powder precipitate dispersed in the solvent is obtained,   wherein said at least one diester is of formula:   R 1 —(CH 2 ) m —R 2 , wherein m represents an integer ranging from 0 to 36, and R 1  and R 2  represent identical or different ester functions of general formula COOR 3 , wherein R 3  represents a saturated or unsaturated, linear or branched alkyl chain of from 1 to 5 carbon atoms and/or R 1 —(C 6 H 4 ) n —R 2 , wherein n represents an integer ranging from 1 to 2, and R 1  and R 2  represent identical or different ester functions of general formula COOR 3 , wherein R 3  represents a saturated or unsaturated, linear or branched alkyl chain of from 1 to 5 carbon atoms;   wherein said at least one diamine is chosen from aliphatic diamines having from 6 to 12 carbon atoms; and   wherein said at least one amino ester corresponds to the general formula R 5 —(CH 2 ) p —R 6 , wherein p represents an integer ranging from 0 to 36, R 5  represents a primary or secondary amine function, and R 6  represents an ester function of general formula COOR 7 , wherein R 7  represents an alkyl chain of from 1 to 5 carbon atoms.   
     
     
         2 . The polycondensate powder of  claim 1 , wherein the polycondensate powder comprises particles of free powder which have a spheroidal shape, a D50 measured according to ISO standard 13320-1:1999 included within the range of from 1 to 200 μm, and wherein the powder further comprises traces of ester chain ends. 
     
     
         3 . The polycondensate powder of  claim 1 , wherein the wherein the powder further comprises from 0 to 50 mol % of a polycondensation catalyst, relative to the number of moles of the polycondensate. 
     
     
         4 . The polycondensate powder of  claim 3 , wherein the polycondensation catalyst is selected from the groups consisting of sodium hydride, potassium hydride, sodium, sodium stearate, ortho-phosphoric acid, stearic acid, ethanol, phenol, sodium methoxide, sodium ethoxide, and mixtures thereof. 
     
     
         5 . The polycondensate powder of  claim 1 , wherein the powder further comprises traces of a polycondensation solvent. 
     
     
         6 . The polycondensate powder of  claim 5 , wherein the polycondensation solvent is selected from the group consisting of linear alkanes, cycloaliphatic alkanes, halogenated solvents and mixtures thereof. 
     
     
         7 . The polycondensate powder of  claim 1 , wherein the powder further comprises traces, relative to the total weight of the powder, of an alcohol of formula R 3 OH and/or R 7 OH, wherein R 3  and R 7  each represent an alkyl chain from 1 to 5 carbon atoms. 
     
     
         8 . The polycondensate powder of  claim 1 , wherein the powder further comprises a polycondensate that is an oligomer having a number-average molar mass included in the range of from 300 g/mol to 5000 g/mol. 
     
     
         9 . The polycondensate powder of  claim 1 , wherein the powder further comprises a polycondensate that is a polyamide having a number-average molar mass of between 5000 and 30 000 g/mol. 
     
     
         10 . A product comprising the powder as claimed in  claim 1 , wherein the product is chosen from coatings, paints, anticorrosion compositions, paper additives, powder agglomeration by electromagnetic radiation-induced melting or sintering for producing objects, electrophoresis gels, multilayer composite materials, packaging, toys, products in the textile, automobile and/or electronics industry, and cosmetic, pharmaceutical or perfumery products. 
     
     
         11 . A polycondensate powder obtained from a process comprising a polycondensation of:
 i) at least one diester and at least one diamine,   and/or   ii) at least one amino ester,   
       the polycondensate powder comprising particles of free powder which have a spheroidal shape, a D50 measured according to ISO standard 13320-1:1999 included within the range of from 1 to 200 μm, wherein the powder further comprises 10 to 4000 meq/kg of ester chain ends relative to the weight of polycondensate. 
     
     
         12 . The polycondensate powder of  claim 11 , wherein the powder further comprises at least one monomer chosen from the units: 2.9, 2.10, 4.6, 4.T, 6, 6.6, 6.9, 6.10, 6.12, 6.T, 9.2, 10.2, 10.10, 10.12, 10.T, 11, 12, 12.9, 12.10, 12.12, 12.T, and mixtures thereof having alternating or block units. 
     
     
         13 . The polycondensate powder of  claim 11 , wherein the powder further comprises 10 to 10,000 ppm of solvent selected from linear alkanes, cycloaliphatic alkanes, halogenated solvents and mixtures thereof. 
     
     
         14 . The polycondensate powder of  claim 11 , wherein the powder further comprises from 0 to 50 mol % of a polycondensation catalyst selected from the group consisting of sodium hydride, potassium hydride, sodium, sodium stearate, ortho-phosphoric acid, stearic acid, ethanol, phenol, sodium methoxide, sodium ethoxide, and mixtures thereof. 
     
     
         15 . The polycondensate powder of  claim 11 , wherein the powder further comprises from 0.01% to 5% by weight of a monoalcohol of formula R 3 OH and/or R 7 OH, wherein R 3  and R 7  each represent a saturated or unsaturated, linear or branched alkyl chain of from 1 to 5 carbon atoms. 
     
     
         16 . The polycondensate powder of  claim 11 , wherein the powder further comprises a polycondensate that is an oligomer of number-average molar mass included in the range of from 300 g/mol to 5000 g/mol. 
     
     
         17 . The polycondensate powder of  claim 11 , wherein the powder further comprises a polycondensate that is a polyamide of number-average molar mass of between 5000 and 30 000 g/mol. 
     
     
         18 . The polycondensate powder of  claim 11 , wherein the powder further comprises from 0.1% to 99.9% by weight of the particles and from 0.1% to 99.9% by weight of a solvent, wherein the solvent is selected from the group consisting of linear alkanes, cycloaliphatic alkanes, halogenated solvents and mixtures thereof. 
     
     
         19 . The polycondensate powder of  claim 11 , wherein the particles have a specific surface area measured according to a Brunauer-Emmet-Teller method ranging from 1 to 20 m 2 /g. 
     
     
         20 . A product comprising the powder as claimed in  claim 11 , wherein the product is chosen from coatings, paints, anticorrosion compositions, paper additives, powder agglomeration by electromagnetic radiation-induced melting or sintering for producing objects, electrophoresis gels, multilayer composite materials, packaging, toys, products in the textile, automobile and/or electronics industry, and cosmetic, pharmaceutical or perfumery products.