Classifications

• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
  • C08G69/02—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids
  • C08G69/26—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids derived from polyamines and polycarboxylic acids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y70/00—Materials specially adapted for additive manufacturing
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G69/00—Macromolecular compounds obtained by reactions forming a carboxylic amide link in the main chain of the macromolecule
  • C08G69/02—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids
  • C08G69/04—Preparatory processes
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/12—Powdering or granulating
  • C08J3/14—Powdering or granulating by precipitation from solutions
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L77/00—Compositions of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Compositions of derivatives of such polymers
  • C08L77/06—Polyamides derived from polyamines and polycarboxylic acids
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29C—SHAPING OR JOINING OF PLASTICS; SHAPING OF MATERIAL IN A PLASTIC STATE, NOT OTHERWISE PROVIDED FOR; AFTER-TREATMENT OF THE SHAPED PRODUCTS, e.g. REPAIRING
  • B29C64/00—Additive manufacturing, i.e. manufacturing of three-dimensional [3D] objects by additive deposition, additive agglomeration or additive layering, e.g. by 3D printing, stereolithography or selective laser sintering
  • B29C64/10—Processes of additive manufacturing
  • B29C64/141—Processes of additive manufacturing using only solid materials
  • B29C64/153—Processes of additive manufacturing using only solid materials using layers of powder being selectively joined, e.g. by selective laser sintering or melting
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2077/00—Use of PA, i.e. polyamides, e.g. polyesteramides or derivatives thereof, as moulding material
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
  • B29K—INDEXING SCHEME ASSOCIATED WITH SUBCLASSES B29B, B29C OR B29D, RELATING TO MOULDING MATERIALS OR TO MATERIALS FOR MOULDS, REINFORCEMENTS, FILLERS OR PREFORMED PARTS, e.g. INSERTS
  • B29K2105/00—Condition, form or state of moulded material or of the material to be shaped
  • B29K2105/25—Solid
  • B29K2105/251—Particles, powder or granules
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y10/00—Processes of additive manufacturing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y80/00—Products made by additive manufacturing
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2377/00—Characterised by the use of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Derivatives of such polymers
  • C08J2377/06—Polyamides derived from polyamines and polycarboxylic acids

Definitions

• the present invention relates to a polyamide powder with a high glass transition temperature, as well as to the corresponding preparation process.
• the invention also relates to articles made therefrom, as well as their manufacturing process.
• compositions based on polyamide powder have a very large number of applications in industry, in particular for the preparation of articles or parts of articles, for example for the automotive sector, the aeronautical sector, electrical and electronic components and consumer goods.
• compositions comprising polyamides are used as raw materials for the manufacture of articles or parts of articles by sintering, for example by laser sintering.
• compositions comprising polyamides in powder form (polyamide powders).
• polyamide powders having selected characteristics, in particular in terms of particle size and their distribution.
• the polyamide powders obtained mainly from units comprising cycloaliphatic diamines are particularly advantageous.
• Such powders exhibit a high glass transition temperature. This makes it possible to manufacture rigid articles having a greater range of use in temperature.
• the polyamide powders currently available have a low glass transition temperature, in particular of 50 ° C or less, and the parts built with these powders therefore have low mechanical properties, in particular the Young's modulus, beyond this temperature.
• the use of Available polyamide powders have drawbacks due to equipment fouling caused by their content of volatile residual compounds and very fine particles.
• the invention relates firstly to a powder comprising at least one polyamide comprising at least one unit corresponding to the formula (cycloaliphatic diamine in Ca). (Cb diacid); said powder having a glass transition temperature of at least 100 ° C; and said powder being in the form of particles having a volume average size of 35 to 120 ⁇ m, and the distribution of which is characterized by a ratio ((Dv ⁇ - Dvio) / Dvso) of 2 or less.
• the at least one polyamide comprises at least 50% by number of polyamide units corresponding to the formula (cycloaliphatic diamine in Ca). (Cb diacid).
• the cycloaliphatic Ca diamine comprises at least one substituted cycloaliphatic ring.
• the cycloaliphatic Ca diamine comprises two rings of cycloaliphatic type and has the general formula: in which :
• R 1, R 2, Fb and FU independently represent a group selected from a hydrogen atom or an alkyl comprising 1 to 6 carbon atoms and;
• X represents either a single bond or a divalent group consisting of: a linear or branched aliphatic group comprising 1 to 10 carbon atoms, optionally substituted by cycloaliphatic or aromatic groups comprising 6 to 8 carbon atoms; or a cycloaliphatic group comprising 6 to 12 carbon atoms.
• the cycloaliphatic Ca diamine is selected from isophoronediamine, 1.2-cyclohexanediamine, 1.3-cyclohexanediamine, 1.4-cyclohexanediamine, 1.3- bis (aminomethyl) cyclohexane, 1.4-bis (aminomethyl) cyclohexane, methyl cyclohexanediamine, norbornanediamine and bis- (3-methyl-4-aminocyclohexyl) -methane and 2,2 ', 4,4'-tetramethylcyclobutanediamine.
• the Cb diacid is an aliphatic diacid, a cycloaliphatic diacid, or an aromatic diacid.
• the polyamide is a homopolyamide consisting of a repeating unit of the formula (cycloaliphatic Ca diamine). (Cb diacid).
• the polyamide is a copolyamide comprising, in addition to the unit corresponding to the formula (cycloaliphatic diamine in Ca).
• (Cb diacid) at least one other unit, said at least other unit possibly being a unit obtained from an amino acid, a unit obtained from a lactam, a unit obtained from a diisocyanate and d 'a carboxylic acid, or a unit corresponding to the formula (diamine in Ca).
• (Cb-diacid) with the proviso that the unit (Ca ′ diamine).
• Cb 'diacid is different from the unit (Ca diamine).
• (Cb diacid) is a copolyamide comprising, in addition to the unit corresponding to the formula (cycloaliphatic diamine in Ca).
• (Cb diacid) at least one other unit, said at least other unit possibly being a unit obtained from an amino acid, a unit obtained from a lactam, a unit obtained from a diis
• the polyamide is a crystallizable polyamide or a semi-crystalline polyamide.
• the powder further comprises fillers, additives, or mixtures thereof.
• the invention relates secondly to a method of manufacturing a powder as defined opposite comprising the following steps: providing a composition comprising at least one polyamide comprising at least one unit corresponding to the formula (cycloaliphatic diamine in That). (Cb diacid) as defined opposite; contacting said polyamide with a solvent to obtain a homogeneous mixture; precipitation of the polyamide composition in powder form.
• the method further comprises a step of drying the powder after the mixture has cooled.
• the invention relates to a method of manufacturing an article by layer-by-layer sintering caused by electromagnetic radiation of the powder as defined below.
• the invention relates to an article manufactured by layer-by-layer sintering caused by electromagnetic radiation from the powder as defined opposite.
• the present invention overcomes the drawbacks of the prior art. It more particularly provides a powder making it possible to manufacture articles having mechanical properties (in particular the Young's modulus) which are constant and high at a higher temperature, which makes it possible to manufacture rigid articles having a greater range of use in temperature. . It allows in particular the supply of polyamide powders having particles of satisfactory size and with limited dispersion. These powders are particularly suitable for additive manufacturing, in particular by sintering caused by electromagnetic radiation such as laser sintering. It thus makes it possible to facilitate the process for manufacturing the articles, in particular by sintering, to allow high precision of execution and satisfactory reproducibility, and to improve the quality of the articles obtained. It also makes it possible to avoid the drawbacks inherent in powders comprising at least one polyamide, such as obtaining a powder comprising undesirable residual compounds having a negative impact on the quality of the articles manufactured and obtaining too fine particles liable to damage. foul the equipment.
• powder is understood to mean a composition in the form of divided particles and with a determined particle size distribution.
• amorphous polyamide is understood to mean a polyamide exhibiting only a glass transition temperature (without any melting endothermic or crystallization exothermic) during the cooling and heating steps at a speed of 20 K / min in differential calorimetric analysis measured according to the ISO 11357-2 standard of 2013.
• polyamide is understood to mean a polyamide exhibiting an enthalpy of crystallization (AH C ), during the step of cooling to a temperature. speed of 20 K / min in differential calorimetric analysis measured according to standard ISO 11357-3 of 2013, greater than 20 J / g, preferably greater than 30 J / g.
• crystallizable polyamide means a polyamide exhibiting an enthalpy of crystallization (AH C ), during the cooling step at a speed of 20 K / min in differential calorimetric analysis measured according to the ISO 11357-3 standard of 2013, of 20 J / g or less; and exhibiting a cold crystallization enthalpy (AH Cf ), during a heating step at a speed of 20 K / min in differential calorimetric analysis measured according to the ISO 11357-3 standard of 2013, greater than 0 J / g, preferably at 5 J / g, very preferably greater than 10 J / g, more preferably greater than 20 J / g.
• AH C enthalpy of crystallization
• ambient temperature is understood to mean a temperature between 18 and 25 ° C, preferably around 20 ° C.
• Spheroidal is understood to mean rounded, quasi-spherical particles. Spheroidal particles are particles without sharp edges, when observed by scanning electron microscopy, and having an average form factor between the largest diameter and the smallest observable diameter of 1 to 2.
• the present invention relates to a powder comprising at least one polyamide comprising at least one unit obtained from a cycloaliphatic Ca diamine monomer, and more particularly a polyamide comprising at least one unit corresponding to the formula (cycloaliphatic diamine in Ca). (Cb diacid); said powder having a glass transition temperature of at least 100 ° C; and said powder being in the form of particles, in particular spheroidal particles, having a volume average size between 35 and 120 ⁇ m, and a dispersion constrained in particle size having a ratio ((Dva - DVIO) / DV5O) of 2 or minus (where Dv x is the volume size of the x th percentile).
• the powder has a glass transition temperature (Tg) of at least 100 ° C.
• the glass transition temperature (Tg) is measured by analysis differential calorimetry at a heating temperature of 20 K / min according to standard ISO 11357-2 of 2013.
• Polyamide powders having a high glass transition temperature (Tg) are particularly advantageous. Such powders make it possible to manufacture articles which have mechanical properties (in particular the Young's modulus) which vary little with temperature and which can therefore be used over a wider temperature range.
• the powder is preferably in the form of sphenoidal particles, very preferably in the form of spherical particles.
• the polyamide particles have an average size by volume between 35 and 120 ⁇ m, preferably between 40 and 80 ⁇ m.
• the particles can have an average size between 35 and 40 ⁇ m; or between 40 and 45 ⁇ m; or between 45 and 50 ⁇ m; or between 50 and 55 ⁇ m; or between 55 and 60 ⁇ m; or between 60 and 65 ⁇ m; or between 65 and 70 ⁇ m; or between 70 and 75 ⁇ m; or between 75 and 80 ⁇ m; or between 80 and 85 ⁇ m; or between 85 and 90 ⁇ m; or between 90 and 95 ⁇ m; or between 95 and 100 ⁇ m; or between 100 and 105 ⁇ m; or between 105 and 110 ⁇ m; or between 110 and 115 ⁇ m; or between 115 and 120 pm.
• the polyamide particles have a particle size dispersion according to the formula (Dva - Dvio) / Dvso of 2 or less.
• a narrow dispersion of the polyamide particles is recommended, both to limit or even eliminate the clogging of devices for manufacturing articles by sintering layer by layer, in particular by laser sintering, and to facilitate the manufacture of said articles and improve their quality.
• the particle size distribution by volume of the polyamide particles is determined according to a usual technique, for example using a Coulter Counter III particle size analyzer, according to the ISO 13319 standard. From the particle size distribution by volume, it is possible to determine the mean diameter by volume as well as the particle size dispersion (Dv ⁇ - DVIO) / DV5O which measures the width of the distribution.
• Dvso denotes the 50 th percentile of the volume distribution of particle sizes, ie 50% by volume of the particles have a size less than Dvso and 50% by volume have a size greater than Dvso. This is the median of the volumetric distribution of the polyamide particles.
• Dvio refers to the I 0 th percentile of the volume distribution of particle sizes, i.e. 10% by volume of the particles are smaller than Dvio and 90% by volume are larger than Dvio .
• Dv ⁇ means the 90th percentile of the volume distribution of particle sizes, that is to say, 90% by volume of the particles are smaller than the DV90 and 10% by volume are greater than the DV90.
• the polyamide particles have a monomodal particle size distribution.
• the apparent specific surface designates the ratio between the real surface area of a particle and the mass of this particle (similar to surface porosity).
• the polyamide particles preferably have an apparent specific surface area measured according to the BET method ranging from 1 to 50 m 2 / g, preferentially from 1 to 20 m 2 / g, very preferably from 2 to 10 m 2 / g, more preferably from 3 at 8 m 2 / g.
• the apparent specific surface is determined according to the international standard ISO 5794/1.
• the powder comprises at least one polyamide comprising at least one unit corresponding to the formula (cycloaliphatic diamine in Ca). (Cb diacid).
• Said polyamide comprises at least one unit corresponding to the formula (cycloaliphatic diamine in Ca). (Cb diacid), with “a” representing the number of carbon atoms of the cycloaliphatic diamine and “b” representing the number of carbon atoms of the diacid, "a” and “b” each being independently between 4 and 36, as defined below.
• the polyamide according to the invention is a homopolyamide, it comprises a single repeating unit corresponding to the formula (C a cycloaliphatic diamine). (Cb diacid).
• the term “homopolyamide” means a polyamide obtained from a single monomer, or, in the case of a polyamide of the diamine type.
• diacid from a single pair of diamine and diacid.
• Such a homopolyamide then consists essentially of units corresponding to the formula (cycloaliphatic diamine in Ca).
• (Cb diacid) The sum (a + b) / 2 is preferably greater than or equal to 8, very preferably greater than or equal to 9, more preferably greater than or equal to 10.
• the polyamide is a copolyamide, it comprises at least two distinct repeating units, including at least one of the units corresponds to the formula (cycloaliphatic diamine in Ca). (Cb diacid).
• the copolyamide preferably further comprises at least one other unit obtained from an amino acid, obtained from a lactam, obtained from a diisocyanate and a carboxylic acid, or corresponding to the formula (diamine in That).
• (Cb diacid) with "a '” representing the number of carbon atoms of the diamine and “b'” representing the number of carbon atoms of the diacid, "a '" and “b'” each being independently between 4 and 36, as defined below.
• the sum (a '+ b') / 2 is preferably greater than or equal to 8, very preferably greater than or equal to 9, more preferably greater than or equal to 10.
• the C-cycloaliphatic diamine advantageously comprises at least one substituted cycloaliphatic ring, preferably two substituted cycloaliphatic rings.
• the cycloaliphatic diamine in Ca can be chosen in particular from isophoronediamine, 1.2-cyclohexanediamine, 1.3-cyclohexanediamine, 1.4-cyclohexanediamine, 1.3-bis (aminomethyl) cyclohexane, 1.4- bis (aminomethyl) cyclohexhexanediamine-diamine cyclohexane , norbornanediamine and bis- (3-methyl-4-aminocyclohexyl) -methane, 2,2 ', 4,4'-tetramethylcyclobutanediamine.
• the cycloaliphatic diamine in Ca can also comprise two rings of cycloaliphatic type and in particular correspond to the following general formula: in which :
• R 1, R 2, R 3 and R 4 independently represent a group selected from a hydrogen atom or an alkyl comprising 1 to 6 carbon atoms and;
• X represents either a single bond or a divalent group consisting of: a linear or branched aliphatic group comprising 1 to 10 carbon atoms, optionally substituted by cycloaliphatic or aromatic groups comprising 6 to 8 carbon atoms; or a cycloaliphatic group comprising 6 to 12 carbon atoms.
• the cycloaliphatic diamine Ca of the polyamide having two cycloaliphatic rings can be chosen from bis (3,5-dialkyl-4-aminocyclohexyl) methane, bis (3,5-dialkyl-4-aminocyclohexyl) ethane, bis ( 3,5-dialkyl-4-aminocyclohexyl) propane, and bis (aminocyclohexyl) propane (PACP) (2,2-bis (4-aminocyclohexyl) propane), bis (3,5-dialkyl-4-aminocyclohexyl) butane , bis- (3-methyl-4-aminocyclohexyl) -methane (denoted BMACM, MACM or B), p- bis (aminocyclohexyl) -methane (PACM).
• the cycloaliphatic diamine Ca of the polyamide having two cycloaliphatic rings can be chosen from bis- (3- methyl-4-aminocyclohexyl) methane (denoted BMACM, MACM or B) and p-bis (aminocyclohexyl) methane (PACM).
• BMACM bis- (3- methyl-4-aminocyclohexyl) methane
• PAM p-bis (aminocyclohexyl) methane
• PACM diamine comprising at least 50% of trans-trans stereoisomer referred to as PACM (50) is particularly preferred.
• the Cb diacid can be an aliphatic diacid, a cycloaliphatic diacid or an aromatic diacid.
• the diacid is an aliphatic Cb diacid, it can be straight or branched, saturated or unsaturated.
• the fatty acid dimers mentioned above are dimerized fatty acids obtained by oligomerization or polymerization of unsaturated monobasic fatty acids with a long hydrocarbon chain (such as linoleic acid and oleic acid), as described in particular in the application. of European patent EP 0471566 A1.
• the Cb diacid is an aromatic diacid
• it can be chosen from terephthalic acid (commonly designated “T”), isophthalic acid (commonly designated “I”) and naphthalenic diacid.
• the Cb diacid is a cycloaliphatic diacid, it may contain the following carbon skeletons: norbornylmethane, cyclohexylmethane, dicyclohexylmethane, dicyclohexylpropane, di (methylcyclohexyl) propane.
• the polyamide is a copolyamide, it further comprises at least one unit other than the unit corresponding to the formula (C a cycloaliphatic diamine). (Cb diacid).
• Said at least one other unit may be a unit obtained from an amino acid, a unit obtained from a lactam, a unit obtained from a diisocyanate and a carboxylic acid, or a unit corresponding to the following.
• the copolyamide can also comprise at least one unit obtained from an amino acid chosen from 9-aminononanoic acid, 10-aminodecanoic acid, 12-aminododecanoic acid and 11-aminoundecanoic acid as well as its derivatives. , especially N-heptyl-11-aminoundecanoic acid.
• the copolyamide may further comprise at least one unit obtained from a lactam chosen from pyrrolidinone, piperidinone, caprolactam, enantholactam, caprylolactam, pelargolactam, decanolactam, undecanolactam, a lactam monoterpene and laurolactam; preferably caprylolactam, pelargolactam, decanolactam, undecanolactam and laurolactam; very preferably laurolactam.
• a lactam chosen from pyrrolidinone, piperidinone, caprolactam, enantholactam, caprylolactam, pelargolactam, decanolactam, undecanolactam, a lactam monoterpene and laurolactam
• caprylolactam, pelargolactam, decanolactam, undecanolactam and laurolactam very preferably laurolactam.
• the copolyamide can also comprise at least one other unit corresponding to the formula (diamine in Ca). (Cb-diacid), with the proviso that the unit (Ca ′ diamine). (Cb 'diacid) is different from the unit (Ca diamine). (Cb diacid).
• the Cb ′ diacid can be chosen from the Cb monomers defined above.
• the Ca diamine can be linear or branched aliphatic, cycloaliphatic or alkylaromatic. When the Ca diamine is a cycloaliphatic diamine, it can be chosen from the Ca diamines defined above.
• the polyamide comprising at least one unit corresponding to the formula (cycloaliphatic diamine in Ca). (diacid in Cb) can be chosen from PA BMACM.10, PA PACM.10, PA BMACM.12, PA PACM.12, PA BMACM.14, PA PACM.14, PA BMACM.18, PA PACM.18, PA 11 / BMACM.10, PA 11 / PACM.10, PA 11 / BMACM.12, PA 11 / PACM.12, PA 11 / BMACM.14, PA
• PACM.14 PA 11 / BMACM.18, PA 11 / PACM.18, PA 12 / BMACM.10, PA
• PACM.10 PA 12 / BMACM.12
• PA 12 / PACM.12 PA 12 / BMACM.14
• PA 12 / BMACM.I / BMACM.T PA 12 / PACM. I / PACM. T, PA 12 / BMACM.I / PACM.I, PA 11 / BMACM.I, PA 11 / PACM.I, PA 11 / BMACM.I / BMACM.T, PA 11 / PACM.I / PACM.T, PA 11 / BMACM.I / PACM.I, PA 10.10 / BMACM.I, PA 10.10 / P ACM. I, PA 10.10 / BMACM. I / BMACM.T, PA 10.10 / PACM.I / PACM.T, PA 10.10 / BMACM. I / P ACM.
• PA 10.12 / BMACM.I PA 10.12 / PACM. I
• PA 10.12 / BMACM.I PA 10.12 / PA PACM.I
• PA 10.12 / BMACM.I PA PACM.I
• PA 10.12 / BMACM. I PA P ACM.
• PA 12.10 / BMACM.I PA 12.10 / PA PACM.I
• PA 12.10 / BMACM.I PA 12.10 / PACM.I
• PA 12.10 / BMACM.I PA 12.10 / PACM.I / PACM.T
• PA 12.14 / BMACM.I / BMACM.T PA 12.14 / PACM.I / PACM.T, PA 12.14 / BMACM.I / PACM.I, PA 10.14 / BMACM.I, PA 10.14 / PACM.I, PA 10.14 / BMACM.I / BMACM.T, PA 10.14 / P ACM. I / PACM.T, PA 10.14 / BMACM.I / PACM.I or their mixtures.
• the polyamide can be chosen from PA BMACM.10, PA BMACM.12, PA BMACM.14, PA PACM.10, PA PACM.12, PA PACM.14, PA Z / BMACM.10, PA Z / BMACM .12, PA Z / BMACM.14, PA Z / BMACM.I, PA Z / BMACM.I / BMACM.T, PA Z / P ACM.10, PA Z / PACM.12, PA Z / PACM.14, PA Z / PACM.I or PA Z / PACM.I / PACM.T in which Z represents 11, 12,
• it can be chosen from the polyamides described in patent application EP 1595907 A1 or in application WO 2009/153534.
• the polyamides of the Rilsan ® CLEAR range from the company Arkema can in particular be used.
• the polyamides of the Trogamid ® range from the company Evonik can in particular be used, for example Trogamid ® CX7323.
• the powder may further comprise at least one additional polyamide not comprising a unit corresponding to the formula (C a cycloaliphatic diamine). (Cb diacid).
• the additional polyamide can be a homopolyamide or a copolyamide.
• the polyamide can be a homopolyamide obtained by polymerization of an amino acid, of a lactam or comprising a unit corresponding to the formula (diamine in Ca ” ). (Cb ” diacid), the Ca ” diamine not being a cycloaliphatic diamine.
• the amino acid can be as defined above.
• the lactam can be as defined above.
• the diamine Ca can be as defined above for the C diamine, except cycloaliphatic diamine.
• the Cb ” diacid can be as defined above for the Cb diacid.
• the polyamide can be chosen from PA 11, PA 10.10, PA 10.12, PA 12.12, PA 10.14 or PA 12.14; preferably PA 11 or PA 10.12; very preferably PA 11.
• the polyamide can comprise at least 50% by number of units obtained from cycloaliphatic diamines relative to all the units of the polyamide, that is to say at least 50% by number of units corresponding to the formula (diamine cycloaliphatic). (diacid) - as defined above - relative to all the units of the polyamide.
• Cycloaliphatic diamines correspond to cycloaliphatic Ca diamines and cycloaliphatic Ca diamines (if present).
• the diacids correspond to the diacids in Cb and the diacids in Cb (if present).
• a large proportion of units corresponding to the formula (cycloaliphatic diamine). (diacid) in the polyamide makes it possible to increase the glass transition temperature (Tg) of the powder.
• the polyamide comprises units of the formula (cycloaliphatic diamine). (diacid) present in a proportion by number, relative to all the units of the polyamide, from 50 to 55%; or from 55 to 60%; or from 60 to 65%; or from 65 to 70%; or from 70 to 75%; or from 75 to 80%; or from 80 to 85%; or from 85 to 90%; or from 90 to 95%; or 95 to 100%.
• the polyamide comprises units of the formula (cycloaliphatic diamine).
• the powder does not include additional polyamide.
• the powder comprising at least 50% of units corresponding to the formula (C a cycloaliphatic diamine).
• (Cb diacid) is homogeneously mixed with another polyamide powder in a proportion by weight of 5 to 10%; or from 10 to 15%; or from 15 to 20%; or from 20 to 25%; or from 25 to 30%; or from 30 to 35%; or from
• the polyamides according to the present invention can be amorphous polyamides, crystallizable polyamides or semi-crystalline polyamides; preferably crystallizable polyamides or semi-crystalline polyamides.
• the powder can further include fillers.
• the fillers can be chosen from conventional mineral fillers, such as those chosen from the group, given without limitation, comprising talc, kaolin, magnesia, slag, silica, carbon black, carbon nanotubes. carbon, expanded or non-expanded graphite, titanium oxide, glass, in particular in the form of beads or fibers.
• the powder can comprise from 10% to 60%, preferably from 20% to 50% by weight of fillers relative to the total weight of the powder.
• composition may also further comprise additives customary in powders, such as: flow agents, nucleating agents, colorants, light (UV) and / or heat stabilizers, plasticizers, agents surfactants, pigments, optical brighteners, antioxidants, waxes, or mixtures thereof.
• additives customary in powders such as: flow agents, nucleating agents, colorants, light (UV) and / or heat stabilizers, plasticizers, agents surfactants, pigments, optical brighteners, antioxidants, waxes, or mixtures thereof.
• the usual stabilizers used with polymers are phenols, phosphites, UV absorbers, stabilizers of the HALS (Hindered Amine Light Stabilizer) type, metal iodides.
• HALS Hindered Amine Light Stabilizer
• the powder may comprise 10% by weight or less, preferably less than 5%, of additives, relative to the total weight of the powder.
• the powder may further be substantially free of any surfactant compound.
• substantially is meant a powder comprising 1% or less; preferably 0.1% or less, very preferably 0.01% or less; more preferably about 0% of a compound, by weight relative to the total weight of the powder.
• the powder is particularly suitable for the manufacture of articles by sintering.
• the powder is particularly suitable also for other applications, in particular its use to manufacture composite materials; multilayer materials; transfer papers; coatings of substrates, for example metal substrates; compositions of inks or paints; cosmetic or pharmaceutical compositions; electrophoresis gels; packaging; articles intended for the transfer of fluid, for example piping, pump or valve accessories; automotive articles, for example in the form of a splined shaft, sliding door track or spring; wire items, for example a dishwasher basket; articles obtained by compression, sintering or melting, for example by use of infrared radiation, ultraviolet radiation or a laser beam.
• the present invention relates to a method of manufacturing a powder according to the first object of the present invention. This process is based on the principle of dissolution / precipitation.
• the method comprises the following steps: providing a composition comprising at least one polyamide comprising at least one unit corresponding to the formula (C a cycloaliphatic diamine). (Cb diacid); contacting said polyamide with a solvent to obtain a homogeneous mixture; precipitation of this polyamide composition in powder form.
• (Cb diacid) is as defined above.
• the composition (raw material) can be prepared by any conventional method which makes it possible to obtain a mixture of homogeneous distribution of the polyamide comprising at least one unit corresponding to the formula (cycloaliphatic diamine in Ca). (Cb diacid), optionally additional polyamides, and optionally additives and / or fillers.
• the preparation method may be melt extrusion, compaction, a method using a roller mixer, or any other suitable method.
• the composition can be prepared by melt mixing all the ingredients in a so-called live process.
• the composition can also be prepared by dry blend.
• the solvent, which is contacted with the polyamide composition can be selected from an alcohol, such as ethanol, propanol, butanol, isopropanol, heptanol; a carboxylic acid such as formic acid, acetic acid; a nitrogenous compound such as N-methyl-pyrrolidone, N-butyl-pyrrolidone; or a lactam such as butyrolactam, caprolactam, or any of their mixtures.
• an alcohol such as ethanol, propanol, butanol, isopropanol, heptanol
• a carboxylic acid such as formic acid, acetic acid
• a nitrogenous compound such as N-methyl-pyrrolidone, N-butyl-pyrrolidone
• a lactam such as butyrolactam, caprolactam, or any of their mixtures.
• the polyamide composition can have a mass fraction in the solvent of 0.05 to 0.5; preferably from 0.1 to 0.3; for example 0.2.
• the composition can in particular have a mass fraction of 0.05 to 0.1; or from 0.1 to 0.15; or from 0.15 to 0.2; or from 0.2 to 0.25; or from 0.25 to 0.3; or from 0.3 to 0.35; or from 0.35 to 0.4; or from 0.4 to 0.45; or from 0.45 to 0.5.
• Contacting to obtain a homogeneous mixture can be carried out by heating the mixture to a temperature at least at least 20 ° C higher than the glass transition temperature of the polyamide composition. Heating the mixture contributes to the solubilization of the polyamide composition in the solvent.
• the contacting to obtain a homogeneous mixture can be carried out at room temperature, before a gradual rise in temperature to the desired temperature.
• Contacting to obtain a homogeneous mixture can be carried out with stirring, in particular with mechanical stirring to promote homogenization and solubilization.
• the heating of the mixture can be carried out at a temperature of at least 120 ° C, preferably between 140 ° C and 250 ° C, most preferably between 170 ° C and 200 ° C.
• the heating can be carried out for a period of 30min to 1 hour; or from 1 hour to 1 hour 30 minutes; or from 1 h 30 to 2 h; or from 2h to 2h30; or from 2h30 to 3h; or from 3 am to 3:30 am; or from 3:30 a.m. to 4 a.m. or from 4 a.m. to 4:30 a.m. or from 4.30 a.m. to 5 a.m. or from 5 a.m. to 5:30 a.m. or from 5:30 a.m. to 6 a.m.
• the polyamide composition is then precipitated from the mixture, for example by controlled cooling. Cooling can be carried out to room temperature.
• the cooling can be carried out at a rate of 10 to 100 ° C per hour; preferably from 10 to 70 ° C per hour; very preferably from 40 to 60 ° C per hour.
• cooling can be performed at a rate of 10 to 15 ° C per hour; or from 15 to 20 ° C per hour; or from 20 to 25 ° C per hour; or from 25 to 30 ° C per hour; or from 30 to 35 ° C per hour; or from 35 to 40 ° C per hour; or from 40 to 45 ° C per hour; or from 45 to 50 ° C per hour; or at 50 to 55 ° C per hour; or from 55 to 60 ° C per hour; or from 60 to 65 ° C per l ⁇ ure; or from 65 to 70 ° C per hour; or from 70 to 75 ° C per hour; or from 75 to 80 ° C per hour; or from 80 to 85 ° C per hour; or from 85 to 90 ° C per hour or from 90 to 95 ° C per hour; or from 95 to 100 ° C per hour;
• the cooling step may further include a level during which the temperature will remain essentially constant for a period of 30min to 6h; preferably from 2 to 5 hours.
• the polyamide powder thus obtained has a monomodal particle size distribution.
• the powder is then separated from the solvent by one of the solid-liquid separation means known to those skilled in the art.
• the method can then comprise a step of drying the powder thus obtained. Drying can be carried out by any suitable method. For example, the drying step can be carried out in an oven.
• Drying can be carried out at a temperature of 10 to 150 ° C; preferably from 25 to 85 ° C; very preferably from 70 to 80 ° C; for example at 75 ° C. In some embodiments the drying can be carried out at a temperature of 10 to 15 ° C; or from 10 to 15 ° C; or from 15 to 20 ° C; or from 20 to 25 ° C; or from 25 to 30 ° C; or dâO at 35 ° C; or from 35 to
• the drying can be carried out under vacuum at a pressure of 10 to 1000 mbar; preferably from 50 to 1000 mbar. In some embodiments, the drying can be carried out at a pressure of 10 to 50 mbar; or from 50 to 100 mbar; or from 100 to 150 mbar; or from 150 to 200 mbar; or from 200 to
• 250 mbar or from 250 to 300 mbar; or from 300 to 350 mbar; or from 350 to
• 400 mbar or from 400 to 450 mbar; or from 450 to 500 mbar; or from 500 to
• 550 mbar or from 550 to 600 mbar; or from 600 to 650 mbar; or from 650 to
• 700 mbar or from 700 to 750 mbar; or from 750 to 800 mbar; or from 800 to
• the drying can be carried out under atmospheric pressure.
• the additives as described above can be added during the supply of the powder, during the contacting with the solvent or after the precipitation.
• the present invention relates to a process for sintering polyamide powder.
• the powder as described above, is used for a method of manufacturing articles by layer-by-layer sintering caused by electromagnetic radiation.
• the electromagnetic radiation can be, for example, infrared radiation, ultraviolet radiation or laser radiation; preferably laser radiation.
• it is a layer-by-layer sintering process caused by laser radiation (in English "laser sintering").
• a thin layer of powder is deposited on a horizontal plate maintained in an enclosure heated to a temperature called the construction temperature.
• This temperature should be lower than the melting temperature of the polyamide but high enough to allow it to melt when it receives electromagnetic radiation.
• the electromagnetic radiation then provides the energy necessary to sinter the powder particles at different points of the powder layer according to a geometry corresponding to an object (for example using a computer having in memory the shape of an object and restoring the latter in the form of slices).
• the horizontal plate is lowered by an amount corresponding to the thickness of a layer of powder, and a new layer is deposited.
• the electromagnetic radiation provides the energy necessary to sinter the powder particles in a geometry corresponding to this new slice of the object and so on. The procedure is repeated until the object has been manufactured.
• the present invention therefore also relates to the use of the polyamide powder for obtaining an article by layer-by-layer sintering of the powder caused by electromagnetic radiation.
• the present invention relates to an article manufactured by layer-by-layer sintering caused by electromagnetic radiation from the powder as defined above.
• Polyamide 12 (comparative) sold under the name Rilsamid® AECNO TL by the company Arkema with a glass transition temperature (Tg) of 40 ° C.
• test 3 and 4 The results obtained with a process and a polyamide according to the invention are compared with the results obtained with a comparative process (test 2 where the heating temperature is not at least 20 ° C higher than relative to the glass transition temperature of the polyamide) and with a comparative polyamide (test 1 where the polyamide does not have a glass transition temperature of at least 100 ° C.).
• Tests 1, 3 and 4 led to the production of a polyamide powder, unlike Test 2 in which the polyamide granules were not solubilized, and therefore no powder was obtained.
• the powders of tests 3 and 4 obtained according to the invention will lead to parts having mechanical properties (in particular the Young's modulus) which are constant and high at a higher temperature (especially for temperatures above the transition temperature. glassy of the polyamide of test 1)
• the particle size analysis demonstrated that the process and the polyamides according to the invention having a glass transition temperature of at least 100 ° C made it possible to obtain polyamide powders having an average size by volume of 35 to 120 ⁇ m and a distribution characterized by a ratio ((Dv ⁇ - Dvio) / Dvso) of 2 or less.

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• 2020
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