Classifications

• • 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
  • C08J5/00—Manufacture of articles or shaped materials containing macromolecular substances
  • C08J5/12—Bonding of a preformed macromolecular material to the same or other solid material such as metal, glass, leather, e.g. using adhesives
  • C08J5/121—Bonding of a preformed macromolecular material to the same or other solid material such as metal, glass, leather, e.g. using adhesives by heating
• • 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
  • C08L77/02—Polyamides derived from omega-amino carboxylic acids or from lactams thereof
• • 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
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D 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 [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y70/00—Materials specially adapted for additive manufacturing
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B33—ADDITIVE MANUFACTURING TECHNOLOGY
  • B33Y—ADDITIVE MANUFACTURING, i.e. MANUFACTURING OF THREE-DIMENSIONAL [3-D] OBJECTS BY ADDITIVE DEPOSITION, ADDITIVE AGGLOMERATION OR ADDITIVE LAYERING, e.g. BY 3-D PRINTING, STEREOLITHOGRAPHY OR SELECTIVE LASER SINTERING
  • B33Y70/00—Materials specially adapted for additive manufacturing
  • B33Y70/10—Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• • 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
  • C08G69/08—Polyamides derived from amino-carboxylic acids or from polyamines and polycarboxylic acids derived from amino-carboxylic acids
  • C08G69/14—Lactams
• • 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
  • C08G69/40—Polyamides containing oxygen in the form of ether groups
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/01—Use of inorganic substances as compounding ingredients characterized by their specific function
  • C08K3/013—Fillers, pigments or reinforcing additives
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/34—Silicon-containing compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
  • C08K3/00—Use of inorganic substances as compounding ingredients
  • C08K3/34—Silicon-containing compounds
  • C08K3/36—Silica
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L101/00—Compositions of unspecified macromolecular compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/04—Homopolymers or copolymers of ethene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
  • C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
  • C08L23/10—Homopolymers or copolymers of propene
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L91/00—Compositions of oils, fats or waxes; Compositions of derivatives thereof
  • C08L91/06—Waxes
• • 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
  • C08J2300/00—Characterised by the use of unspecified polymers
  • C08J2300/22—Thermoplastic resins
• • 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
  • C08J2491/00—Characterised by the use of oils, fats or waxes; Derivatives thereof
  • C08J2491/06—Waxes

Definitions

• the present invention relates to a composition for the manufacture of a three-dimensional (3D) article layer by layer, by sintering, caused by electromagnetic radiation. More particularly, the present invention relates to a composition comprising a powder of semi-crystalline thermoplastic polymer and a wax, and its method of preparation. The invention also relates to the use of this composition and to articles made from it.
• 3D articles The construction of 3D articles is often used to produce prototypes, models of parts ("rapid prototyping") or to produce finished parts in small series (“rapid manufacturing”), for example in the fields: automotive, nautical, aeronautics, aerospace, medical (prostheses, hearing systems, cellular tissues ...), textiles, clothing, fashion, decoration, housings for electronics, telephony, home automation, IT, lighting, sport, industrial tools.
• the manufacturing process by sintering is particularly interesting.
• a layer of polymer powder is selectively and briefly irradiated in a chamber by electromagnetic radiation (eg laser beam, infrared radiation, UV radiation), the result being that the powder particles impacted by the radiation melt.
• electromagnetic radiation eg laser beam, infrared radiation, UV radiation
• the molten particles coalesce and solidify to form a solid mass.
• This process can easily produce 3D articles by repeatedly irradiating a succession of freshly applied powder layers.
• the quality of the manufactured parts as well as their mechanical properties depend on the characteristics of the polymer powder.
• Thermoplastic polymers are appreciated for being used for restrictive temperature and / or mechanical, or even chemical, applications.
• Thermoplastic elastomeric polymers have proven to be particularly interesting: they combine mechanical properties with very good resistance to thermal or UV aging, as well as low density, which thus allow the production of light and flexible parts.
• thermoplastic polymer powders must be adapted to be used in sintering devices.
• the powder must be able to be conveyed and form a uniform bed, without clumping or forming clusters or crevices.
• an additive such as a flow agent can improve flow properties to some extent.
• working window is meant the temperature range of the powder bed at which sintering is actually possible.
• the working window can be narrow (e.g. less than 5 ° C) or none.
• thermoplastic polymer powder in particular on elastomeric thermoplastic polymer, which makes it possible to manufacture articles of good quality, having good mechanical properties and precise and well-defined dimensions and contours, in particular. by making it possible to work with a larger working window, and to implement the method more easily.
• powder bed cohesion problems have been observed during sintering. More specifically, the parts being manufactured can sink inside the powder bed and come up on its edges, which prevents the completion of their manufacture. It is therefore sought to provide a powder composition which makes it possible to reinforce the cohesion of the bed in order to prevent the parts from sinking into the powder bed during sintering.
• thermoplastic polymer powder composition having good recyclability.
• the present invention makes it possible to meet the needs expressed above.
• the present invention relates to a composition for the construction of a three-dimensional (3D) article layer by layer, by sintering of the composition, caused by electromagnetic radiation, the composition comprising:
• the wax having a dropping point higher than the crystallization temperature (Te) of the semi-crystalline thermoplastic polymer
• the semi-crystalline thermoplastic polymer (TP sc) is an elastomer.
• composition of the present invention makes it possible to construct 3D articles having good definition and homogeneity over the whole of the part concerning its physical, mechanical and even chemical properties.
• the TP sc polymer is chosen from:
• PVDF vinylidene fluoride
• thermoplastic polyurethane (TPU) a thermoplastic polyurethane (TPU)
• the TP sc polymer is an elastomer, chosen from:
• the wax can be chosen in particular from polyolefin waxes, waxes of plant or animal origin as well as mixtures thereof, for example, the wax can be chosen from polyethylene and polypropylene waxes, polytetrafluoroethylene waxes, waxes of ketones, acid waxes, partially esterified acid waxes, acid anhydride waxes, ester waxes, aldehyde waxes, amide waxes, their derivatives and mixtures thereof.
• the invention also relates to a process for preparing the composition described above comprising:
• the placing of the TP sc polymer into contact with the wax is carried out by dry mixing.
• the TP sc polymer is brought into contact with the wax:
• the invention also relates to the use of the composition described above, for the construction of a layer-by-layer 3D article, by sintering of the composition caused by electromagnetic radiation, preferably by laser radiation.
• the invention also relates to a 3D article made from the composition described above, preferably by layer-by-layer construction by sintering caused by electromagnetic radiation, preferably by laser radiation.
• sintering caused by electromagnetic radiation, preferably by laser radiation.
• composition further comprises a flow agent.
• the invention relates to the use of a wax to increase the cohesion of the bed of TP sc polymer powder in a sintering process by electromagnetic radiation, preferably by laser radiation.
• composition according to the invention further exhibits good recyclability.
• the wax at the temperature of the powder bed, adheres to the polymer particles, which allows the cohesion of the powder bed to be increased; once the sintering has been carried out, and when the temperature of the powder bed decreases, the wax stiffens and peels off from the unsintered polymer particles, which makes it possible to recycle and reuse them.
• the invention relates to the use of a particular wax in a powder composition based on the TP sc polymer to improve the recyclability of powders in a construction of 3D articles by sintering.
• the invention relates to a method of constructing articles by sintering using a composition as described above where the method comprises a step of recycling the unsintered powders.
• the composition is reused in several successive constructions.
• the invention relates to the 3D article obtained from a composition comprising recycled TP sc polymer powders.
• thermoplastic polymer according to the invention is semi-crystalline.
• thermoplastic polymer means a thermoplastic polymer which has:
• Te crystallization temperature
• Tf melting temperature
• AHf enthalpy of fusion
• the semi-crystalline thermoplastic polymer of the invention can have a Tm of 100 to 300 ° C, and preferably 120 to 200 ° C. This Tf corresponds to the first heating.
• the TP sc polymer can have a Te of 40 to 250 ° C, and preferably from 45 to 200 0 C, for example from 45 to 150 0 C.
• the Tf and Te are determined directly from the TP sc powder.
• the difference between the Te and the Tf of the TP sc polymer is preferably greater than or equal to 20 ° C, preferably greater than or equal to 30 ° C, preferably greater than or equal to 40 ° C, or to 50 ° C. , or at 60 ° C, or at 70 ° C, or at 0 ° C.
• the TP sc polymer of the invention can in particular be chosen from polyamides, PVDF, PEBA, TPU, COPE and mixtures thereof.
• the semi-crystalline thermoplastic polymer is a semi-crystalline polyamide (PA sc). It may be a homopolyamide or a copolyamide, or else a mixture of these.
• PA sc semi-crystalline polyamide
• the polyamide according to the invention can be obtained by the polymerization of a monomer (homopolyamide) or of at least two different monomers (copolyamide) chosen from:
• amino acid type monomers as examples of a, o> amino acids, mention may be made of those having from 4 to 18 carbon atoms, such as aminocaproic, 7-aminoheptanoic, 11-aminoundecanoic, N-heptyl acids. -11- aminoundecanoic and 12-aminododecanoic.
• lactam-type monomers by way of examples, mention may be made of those having from 3 to 18 carbon atoms on the main cycle and which may be substituted. Mention may be made, for example, of b, b-dimethylpropriolactam, a, a-dimethylpropriolactam, amylolactam, caprolactam also called lactam 6, capryllactam also called lactam 8, oenantholactam and lauryllactam also called lactam 12.
• dicarboxylic acid examples include acids having from 4 to 36 carbon atoms. Mention may be made, for example, of adipic acid, sebacic acid, azelaic acid, suberic acid, isophthalic acid, butanedioic acid, 1,4 cyclohexyldicarboxylic acid, terephthalic acid, sodium or lithium salt of sulphoisophthalic acid, dimerized fatty acids (these dimerized fatty acids have a dimer content of at least 98% and are preferably hydrogenated) and dodecanedioic acid HOOO- (OH) io-OOOH, and tetradecanedioic acid.
• adipic acid sebacic acid, azelaic acid, suberic acid
• isophthalic acid butanedioic acid
• 1,4 cyclohexyldicarboxylic acid 1,4 cyclohexyldicarboxylic acid
• terephthalic acid sodium or
• dimerized fatty acids is understood to mean more particularly the product of the reaction of dimerization of fatty acids (generally containing 18 carbon atoms, often a mixture of oleic and / or linoleic acid). It is preferably a mixture comprising 0 to 15% C18 monoacids, 60 to 99% C36 diacids, and 0.2 to 35% triacids or polyacids C54 or more.
• a diamine By way of example of a diamine, mention may be made of aliphatic diamines having from 4 to 36 atoms, preferably from 4 to 18 atoms, which may be saturated aryl and / or cyclic.
• hexamethylenediamine piperazine (abbreviated as "Pip"), aminoethylenepiperazine, tetramethylene diamine, octamethylene diamine, decamethylene diamine, dodecamethylene diamine, 1, 5 diaminohexane, 2 , 2,4-trimethyl-1,6-diamino-hexane, polyols diamine, isophorone diamine (IPD), methyl pentamethylenediamine (MPMD), bis (aminocyclohexyl) methane (BACM), bis (3-methyl -4 aminocyclohexyl) methane (BMACM), p-bis (aminocyclohexyl) -methane commonly referred
• diamines.diacids mention may be made more particularly of those resulting from the condensation of 1, 6-hexamethylenediamine with a dicarboxylic acid having from 6 to 36 carbon atoms and those resulting from the condensation of 1, 10 -decamethylenediamine with a diacid having from 6 to 36 carbon atoms.
• monomers of the “diamine.diacid” type mention may be made in particular of the monomers: 66, 610, 611, 612, 614, 618. Mention may be made of the monomers resulting from the condensation of decanediamine with a diacid in C6 to C36, in particular the monomers: 1010, 1012, 1014, 1018.
• XY X represents the number of carbon atoms resulting from the diamine residues
• Y represents the number of carbon atoms resulting from the residues of diacid, in a conventional manner.
• the homopolyamide is typically an aliphatic homopolyamide, preferably a linear aliphatic homopolyamide.
• the copolyamide can be aliphatic, aromatic or semi-aromatic.
• the PA sc is a semi-aromatic copolyamide, for example of formula X / YAr, as described in EP1505099, in particular of formula A / XT in which A is chosen from a unit obtained from a amino acid, a unit obtained from a lactam and a unit corresponding to the formula (diamine.diacid).
• XT denotes a unit obtained from the polycondensation of a Cx diamine and terephthalic acid, with x representing the number of carbon atoms of the Cx diamine, x being between 6 and 36, advantageously between 9 and 18, in particular a polyamide of formula A / 6T, A / 9T, A / 10T or A / 11T, A being as defined above, in particular a polyamide chosen from MPMDT / 6T, / 10T, 5T / 10T, 11 / BACT,
• T corresponding to terephthalic acid
• MXD corresponding to m - xylylenediamine
• MPMD corresponding to methylpentamethylene diamine
• BAC corresponding to bis (aminomethyl) cyclohexane
• the polyamide is chosen from polyamide (PA) 11, PA 12 or PA 6.
• the homopolyamide or the copolyamide in the context of the invention is a TP sc polymer having a Te, a Tf and an AHf as defined above.
• PVDF Vinylidene Fluoride Polymer
• the semi-crystalline thermoplastic polymer is a PVDF.
• PVDF can be a homopolymer or a copolymer.
• copolymer denotes here generically the polymers obtained by polymerization of VDF with at least one other comonomer, ie polymers having repeating units derived from VDF and from at least one other comonomer.
• it is a copolymer in the strict sense, that is to say having repeating units derived from VDF and from a single other comonomer.
• the comonomer is a halogenated alkene, and more preferably a fluorinated alkene.
• Mention may in particular be made of halogenated propenes or ethylenes, and more particularly fluoroethylene (or vinyl fluoride), chlorofluoroethylenes (1 -chloro-1 -fluoroethylene and 1-chloro-2-fluoroethylene), trifluoroethylene, chlorodifluoroethylenes (in particular 1 - chloro-2,2-difluoroethylene), 1-bromo-2,2-difluoroethylene, bromotrifluoroethylene, chlorotrifluoroethylene, tetrafluoroethylene, trifluoropropenes (in particular 3,3,3-trifluoropropene), tetrafluoropropenes (in particular 2 , 3,3,3-tetrafluoropropene), chlorotrifluoropropenes (in particular 2-chloro-3
• It may also be a perfluoroalkylvinylether, of general formula R f -O-CF-CF, Ft f being an alkyl group, preferably C1 to C4.
• Preferred examples are PPVE (perfluoropropylvinylether) and PMVE (perfluoromethylvinylether).
• PVDF can be obtained by known polymerization methods such as solution, emulsion or suspension polymerization. According to one embodiment, it is prepared by an emulsion polymerization process in the absence of fluorinated surfactant.
• PVDF when it is a copolymer, can be homogeneous or heterogeneous, and preferably homogeneous.
• a homogeneous copolymer has a uniform chain structure, the statistical distribution of the comonomers not varying between the polymer chains.
• the polymer chains In a heterogeneous copolymer, the polymer chains have an average comonomer content distribution of multimodal or spread type: it therefore comprises polymer chains rich in a comonomer and polymer chains poor in said comonomer.
• An example of heterogeneous PVDF appears in document WO 2007/080338.
• a homogeneous copolymer can be prepared by a one-step process, in which the comonomers are injected gradually while keeping a constant mass ratio between them.
• the polymer is an elastomeric TP sc polymer chosen from a PEBA copolymer, a TPU or a COPE.
• the elastomeric thermoplastic has an instantaneous hardness less than or equal to 40 Shore D, more preferably less than or equal to 35 Shore D.
• the hardness measurements can be carried out according to standard ISO 868: 2003.
• PEBA Polyamide block and polyether block copolymer
• the semi-crystalline thermoplastic polymer is a "PEBA" copolymer, it may preferably be a linear (non-crosslinked) copolymer.
• PEBAs result from the polycondensation of polyamide blocks with reactive ends with polyether blocks with reactive ends, such as, among others, polycondensation:
• polyamide blocks containing dicarboxylic chain ends with polyoxyalkylene blocks containing diamine chain ends obtained for example by cyanoethylation and hydrogenation of aliphatic ⁇ , w-dihydroxylated polyoxyalkylene blocks called polyetherdiols;
• the polyamide blocks containing dicarboxylic chain ends originate, for example, from the condensation of polyamide precursors in the presence of a dicarboxylic acid chain limiter.
• the polyamide blocks having diamine chain ends originate, for example, from the condensation of polyamide precursors in the presence of a chain-limiting diamine.
• Three types of polyamide blocks can advantageously be used.
• the polyamide blocks come from the condensation of a dicarboxylic acid, in particular those having 4 to 20 carbon atoms, preferably those having 6 to 18 carbon atoms, and an aliphatic diamine. or aromatic, in particular those having 2 to 20 carbon atoms, preferably those having 6 to 14 carbon atoms.
• dicarboxylic acids mention may be made of butanedioic, adipic, azelaic, suberic, sebacic, dodecanedicarboxylic, octadecanedicarboxylic and terephthalic and isophthalic acids, but also dimerized fatty acids.
• diamines examples include tetramethylene diamine, hexamethylenediamine, 1, 10-decamethylenediamine, dodecamethylenediamine, trimethylhexamethylene diamine.
• polyamide blocks PA 412, PA 414, PA 418, PA 610, PA 612, PA 614, PA 618, PA 912, PA 1010, PA 1012, PA 1014 and PA 1018 are used.
• X represents the number of carbon atoms resulting from the diamine residues
• Y represents the number of carbon atoms resulting from the diacid residues, in a conventional manner.
• the polyamide blocks result from the condensation of one or more ⁇ , w-aminocarboxylic acids and / or of one or more lactams having from 6 to 12 carbon atoms.
• lactams include caprolactam, enantholactam and lauryllactam.
• ⁇ , w-amino carboxylic acid mention may be made of aminocaproic, 7-amino-heptanoic, 11-amino-undecanoic and 12-amino-dodecanoic acids.
• the polyamide blocks of the second type are blocks of PA 11 (polyundecanamide), of PA 12 (polydodecanamide) or of PA 6 (polycaprolactam).
• PA 11 polyundecanamide
• PA 12 polydodecanamide
• PA 6 polycaprolactam
• PA X represents the number of carbon atoms resulting from amino acid residues.
• the condensation according to this type can be carried out in the presence of a chain limiter, for example, a dicarboxylic acid having 4 to 12 carbon atoms or a diamine.
• a chain limiter for example, a dicarboxylic acid having 4 to 12 carbon atoms or a diamine.
• the polyamide blocks result from the condensation of at least one ⁇ , w-aminocarboxylic acid (or one lactam), at least one diamine and at least one dicarboxylic acid.
• polyamide PA blocks are prepared by polycondensation:
• said ⁇ Z ⁇ comonomer (s) being introduced in a proportion by weight advantageously ranging up to 50%, preferably up to 20%, even more advantageously up to 10% relative to all the polyamide precursor monomers;
• the dicarboxylic acid having Y carbon atoms which is introduced in excess relative to the stoichiometry of the diamine (s), is used as chain limiter.
• the polyamide blocks result from the condensation of at least two a, w-aminocarboxylic acids or of at least two lactams having from 6 to 12 carbon atoms or of a lactam and a aminocarboxylic acid not having the same number of carbon atoms in the possible presence of a chain limiter.
• aliphatic ⁇ , w-aminocarboxylic acid mention may be made of aminocaproic, 7-amino-heptanoic, 11-amino-undecanoic and 12-aminododecanoic acids.
• lactam By way of examples of a lactam, mention may be made of caprolactam, oenantholactam and lauryllactam.
• aliphatic diamines mention may be made of hexamethylenediamine, dodecamethylenediamine and trimethylhexamethylene diamine.
• dimerized fatty acids preferably have a dimer content of at least 98%; preferably they are hydrogenated; it is for example the products marketed under the brand "PRIPOL®” by the company "CRODA”, or under the brand EMPOL® by the company BASF, or under the brand Radiacid® by the company OLEON, and polyoxyalkylenes a, w-diacids.
• aromatic diacids mention may be made of terephthalic (T) and isophthalic (I) acids.
• polyamide blocks of the third type As examples of polyamide blocks of the third type, the following may be mentioned:
• 66/610/11 / 12 where 66 denotes hexamethylenediamine condensed with adipic acid, 610 denotes hexamethylenediamine condensed with sebacic acid, 11 denotes units resulting from the condensation of aminoundecanoic acid and 12 denotes units resulting from the condensation of lauryllactam.
• PA X / Y, PA X / Y / Z, etc. relate to copolyamides in which X, Y, Z, etc. represent homopolyamide units as described above.
• the polyamide blocks of the copolymer used in the invention comprise blocks of polyamide PA 6, PA 11, PA 12, PA 54, PA 59, PA 510, PA 512, PA 513, PA 514, PA 516, PA 518, PA 536, PA 64, PA 69, PA 610, PA 612, PA 613, PA 614, PA 616, PA 618, PA 636, PA 104, PA 109, PA 1010, PA 1012, PA 1013, PA 1014, PA 1016 , PA 1018, PA 1036, PA 10T, PA 124, PA 129, PA 1210,
• Polyether blocks are made from alkylene oxide units.
• the polyether blocks can in particular be blocks resulting from PEG (polyethylene glycol), ie consisting of ethylene oxide units, and / or blocks resulting from PPG (propylene glycol), ie consisting of oxide units of propylene, and / or blocks derived from P03G (polytrimethylene glycol), i.e. made up of polytrimethylene glycol ether units, and / or blocks derived from PTMG, i.e. made up of tetramethylene glycol units also called polytetrahydrofuran.
• the PEBA copolymers can comprise several types of polyethers in their chain, the copolyethers possibly being block or random.
• the polyether blocks can also consist of ethoxylated primary amines.
• ethoxylated primary amines mention may be made of the products of formula:
• m and n are integers between 1 and 20 and x an integer between 8 and 18.
• the polyether blocks can comprise polyoxyalkylene blocks containing NH 2 chain ends, such blocks being obtainable by cyanoacetylation of aliphatic ⁇ , w-dihydroxylated polyoxyalkylene blocks called polyetherdiols.
• polyetherdiols More particularly, the commercial Jeffamine or Elastamine products can be used (for example Jeffamine® D400, D2000, ED 2003, XTJ 542, commercial products from the Huntsman company, also described in the documents JP 2004346274, JP 2004352794 and EP 1482011).
• the polyetherdiol blocks are either used as such and copolycondensed with polyamide blocks having carboxylic ends, or aminated to be transformed into polyether diamines and condensed with polyamide blocks having carboxylic ends.
• a general two-step preparation method of PEBA copolymers having ester bonds between the PA blocks and the PE blocks is known and is described, for example, in document FR 2846332.
• a general method of preparing PEBA copolymers having amide bonds between PA blocks and PE blocks is known and described, for example, in document EP 1482011.
• the polyether blocks can also be mixed with polyamide precursors and a diacid chain limiter to prepare polymers containing polyamide blocks and polyether blocks having units distributed in a statistical manner (one-step process).
• PEBA in the present description of the invention relates both to PEBAX® marketed by Arkema, to Vestamid® marketed by Evonik®, to Grilamid® marketed by EMS, and to Pelestat® type PEBA marketed by Sanyo or any other PEBA from other suppliers.
• block copolymers described above generally comprise at least one polyamide block and at least one polyether block
• the present invention also covers all the copolymers comprising two, three, four (or even more) different blocks chosen from those described in the present invention. description, provided that these blocks include at least polyamide and polyether blocks.
• the copolymer according to the invention can comprise a segmented block copolymer comprising three different types of blocks (or “triblock”), which results from the condensation of several of the blocks described above.
• Said triblock is preferably chosen from copolyetheresteramides and copolyetheramideurethanes.
• PEBA copolymers in the context of the invention are copolymers comprising blocks: PA 11 and derived from PEG; PA 11 and from PTMG; PA 12 and derived from PEG; PA 12 and derived from PTMG; PA 1010 and derived from PEG; PA 1010 and derived from PTMG; PA 610 and from PTMG; PA 610 and derived from PEG; PA 6 and derived from PEG; PA 6 and from PTMG.
• the number-average molar mass of the polyamide blocks in the PEBA copolymer is preferably from 100 to 20,000 g / mol, more preferably from 200 to 10,000 g / mol, even more preferably from 200 to 2,000 g / mol.
• the number-average molar mass of the polyamide blocks in the PEBA copolymer is from 100 to 200 g / mol, or from 200 to 500 g / mol, or from 500 to 1000 g / mol, or from 1000 to 1500 g / mol, or from 1500 to 2000 g / mol, or from 2000 to 2500 g / mol, or from 2500 to 3000 g / mol, or from 3000 to 3500 g / mol, or from 3500 to 4000 g / mol, or from 4000 to 5000 g / mol, or from 5000 to 6000 g / mol, or from 6000 to 7000 g / mol, or from 7000 to 8000 g / mol, or from 8000 to 9000 g / mol, or from 9000 to 10,000 g / mol, or 10,000 to 11,000 g / mol, or 11,000 to 12,000 g / mol, or 12,000 to 13,000
• the number-average molar mass of the polyether blocks is preferably from 100 to 6000 g / mol, more preferably from 200 to 3000 g / mol, even more preferably from 800 to 2500 g / mol. In embodiments, the number-average molar mass of the polyether blocks is from 100 to 200 g / mol, or from 200 to 500 g / mol, or from 500 to 800 g / mol, or from 800 to 1000 g / mol.
• the number-average molar mass is fixed by the chain limiter content. It can be calculated according to the relation:
• Mn nmonomer X MW repeat pattern / chain niimiter + MW chain limiter
• n monomer represents the number of moles of monomer
• ni chain imitor represents the number of moles of excess limiter (for example diacid)
• MW repeat pattern represents the molar mass of the repeat pattern
• MWi chain imitor represents the molar mass of the excess limiter (eg diacid).
• the number-average molar mass of the polyamide blocks and of the polyether blocks can be measured before the copolymerization of the blocks by gel permeable chromatography (GPC).
• the mass ratio of the polyamide blocks relative to the polyether blocks of the PEBA copolymer can in particular be from 0.1 to 20. This mass ratio can be calculated by dividing the number-average molar mass of the polyamide blocks by the number-average molar mass of the blocks. polyethers.
• the mass ratio of the polyamide blocks relative to the polyether blocks of the PEBA copolymer can be from 0.1 to 0.2; or from 0.2 to 0.3; or from 0.3 to 0.4; or from 0.4 to 0.5; or from 0.5 to 1; or from 1 to 2; or from 2 to 3; or from 3 to 4; or from 4 to 5; or from 5 to 7; or from 7 to 10; or from 10 to 13; or from 13 to 16; or from 16 to 19; or from 19 to 20. Ranges from 2 to 19, and more specifically from 4 to 10, are particularly preferred.
• Polyester block / polyether block copolymer (COPE) Polyester block / polyether block copolymer (COPE)
• the TP sc polymer is a COPE, also called a copolyetherester.
• the COPEs according to the invention therefore include any thermoplastic elastomeric polymer comprising at least one polyether (PE) block, and at least one PES polyester block (homopolymer or copolyester).
• PE polyether
• PES polyester block homopolymer or copolyester
• COPEs comprise flexible PE blocks derived from polyetherdiols and rigid polyester blocks which result from the reaction of at least one dicarboxylic acid with at least one chain-extending short diol unit.
• the PES blocks and the PE blocks are linked by ester bonds resulting from the reaction of the acid functions of dicarboxylic acid with the OH functions of the polyetherdiol.
• the short chain-extending diol can be chosen from the group consisting of neopentylglycol, and aliphatic glycols of formula HO (CH) n OH in which n is an integer of 2 to 10.
• the sequence of polyethers and diacids forms the flexible blocks whereas the linking of the glycol or of the butanediol with the diacids forms the rigid blocks of the copolyetherester.
• the diacids are aromatic dicarboxylic acids having from 8 to 14 carbon atoms. Up to 50 mole% of the aromatic dicarboxylic acid can be replaced by at least one other aromatic dicarboxylic acid having 8 to 14 carbon atoms, and / or up to 20 mole% can be replaced by an aliphatic acid dicarboxylic having 2 to 14 carbon atoms.
• aromatic dicarboxylic acids By way of example of aromatic dicarboxylic acids, mention may be made of terephthalic, isophthalic, bibenzoic acid, naphthalene dicarboxylic, 4,4'-diphenylenedicarboxylic acid, bis (p-carboxyphenyl) methane acid, ethylene bis p-benzoic acid, 1 -4 tetramethylene bis (p-oxybenzoic) acid, ethylene bis (p-oxybenzoic) acid, 1, 3-trimethylene bis (p-oxybenzoic) acid.
• glycols By way of example of glycols, mention may be made of ethylene glycol, 1, 3-trimethylene glycol, 1, 4-tetramethylene glycol, 1, 6-hexamethylene glycol, 1, 3 propylene glycol, 1, 8 octamethylene glycol, 1, 10-decamethylene glycol.
• COPEs are copolymers having PE units derived from polyetherdiols as defined above, for example polyethylene glycol (PEG), polypropylene glycol (PPG), polytrimethylene glycol (P03G) or polytetramethylene glycol (PTMG), and units PES resulting from the reaction of a dicarboxylic acid such as terephthalic acid with a glycol, ethane diol or 1, 4-butanediol.
• PEG polyethylene glycol
• PPG polypropylene glycol
• P03G polytrimethylene glycol
• PTMG polytetramethylene glycol
• units PES resulting from the reaction of a dicarboxylic acid such as terephthalic acid with a glycol, ethane diol or 1, 4-butanediol.
• Such copolyetheresters are described in patents EP402883 and EP405227.
• TPU Thermoplastic polyurethane
• the semi-crystalline thermoplastic polymer is a TPU, i.e. a copolymer with polyurethane (PU) blocks and polyether (PE) blocks, also called polyetherurethane.
• TPU i.e. a copolymer with polyurethane (PU) blocks and polyether (PE) blocks, also called polyetherurethane.
• TPUs result from the condensation of flexible PE blocks which are polyetherdiols and rigid PU blocks.
• the PU blocks and the PE blocks are linked by bonds resulting from the reaction of the isocyanate functions of the polyurethane with the —OH functions of the polyetherdiol.
• PU within the meaning of the invention is meant the products resulting from the reaction of at least one diisocyanate which can be chosen from aromatic diisocyanates (eg MDI, TDI) and / or aliphatic diisocyanates (eg: HDI or hexamethylenediisocyanate) with at least one short diol.
• This short chain-extending diol can be chosen from the glycols mentioned above in the description of the copolyetheresters.
• the PUs entering into the composition of the copolymers according to the invention can comprise all types of polyols, and in particular those of renewable origin, such as polyols derived from starch (erythritol, sorbitol, maltitol, mannitol), the polyols derived from sugars such as sucrose (isomalt, xylitol), polyols from corn, soybeans, cotton, rapeseed, sunflower or peanuts (glycerol, propylene glycol, ethylene glycol, reaction co-product of biodiesel production ).
• polyols derived from starch (erythritol, sorbitol, maltitol, mannitol)
• sugars such as sucrose (isomalt, xylitol)
• polyols from corn, soybeans, cotton, rapeseed, sunflower or peanuts glycerol, propylene glycol, ethylene glycol, reaction co-product of bio
• polystyrene foams which can enter into the composition of these polyurethanes, one can also quote the polyethylene glycol (PEG), the poly (1, 2-propylene glycol) (PPG), the poly (1, 3-propylene glycol) (P03G) , polytetramethylene glycol (PTMG).
• PEG polyethylene glycol
• PPG poly (1, 2-propylene glycol)
• P03G poly (1, 3-propylene glycol)
• PTMG polytetramethylene glycol
• the semi-crystalline elastomeric thermoplastic polymer can also be chosen from styrene block copolymers (TPS), thermoplastic polyolefin elastomers (TPO), thermoplastic vulcanizates (TPV).
• TPS styrene block copolymers
• TPO thermoplastic polyolefin elastomers
• TPV thermoplastic vulcanizates
• thermoplastic elastomeric polymers examples include the products CAWITON®, THERMOLAST K®, THERMOLAST M®, Sofprene®, Dryflex® and Laprene® (TPS), Desmopan® or Elastollan® (TPU), Santoprene®, Termoton®, Solprene®, THERMOLAST V®, Vegaprene®, or Forprene® (TPV), and For-Tec E® or Engage. Ninjaflex® (TPO).
• CAWITON® THERMOLAST K®, THERMOLAST M®, Sofprene®, Dryflex® and Laprene® (TPS), Desmopan® or Elastollan® (TPU), Santoprene®, Termoton®, Solprene®, THERMOLAST V®, Vegaprene®, or Forprene® (TPV), and For-Tec E® or Engage. Ninjaflex® (TPO).
• the semi-crystalline thermoplastic polymer is a polymer chosen from homopolymers and copolymers of polyoxymethylene (POM), polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyterephthalate of butylene (PBT), polyphthalamides (PPA), and poly (p-phenyleneterephthalamide).
• POM polyoxymethylene
• PE polyethylene
• PP polypropylene
• PET polyethylene terephthalate
• PBT polyterephthalate of butylene
• PPA polyphthalamides
• poly (p-phenyleneterephthalamide) polyoxymethylene
• the wax of the invention is generally a solid compound at room temperature.
• the wax can be malleable at 20 ° C.
• the wax may have a coarse to fine crystal structure, translucent to opaque in appearance but not glassy. Wax can begin to melt above 40 ° C without breaking down. The wax may exhibit a melt viscosity (less than 10,000 mPa.s) at 10 ° C above its dropping point.
• the wax can be a hydrophobic compound.
• the wax used in the invention may in particular be chosen from synthetic waxes, such as polyolefin waxes, waxes of mineral (eg Montan's wax), petroleum or vegetable origin (eg carnauba wax or wax of candelilla) or animals as well as their mixtures.
• synthetic waxes such as polyolefin waxes, waxes of mineral (eg Montan's wax), petroleum or vegetable origin (eg carnauba wax or wax of candelilla) or animals as well as their mixtures.
• the wax as mentioned above generally consists of hydrocarbon compounds comprising from 10 to 100 carbon atoms, preferably from 15 to 60 carbon atoms.
• the wax is a wax of the aforementioned functionalized type which can comprise at least one polar group chosen from an ester, an ether, an acid, an acid anhydride, a carboxylate, an amide, an amine or an alcohol, preferably an ester, an acid, an acid anhydride, or an amide.
• the acidic group is typically a carboxylic acid.
• a functionalized wax can be obtained by functionalizing an existing wax, in particular by oxidation reaction or grafting reaction.
• the functionalized wax can be obtained by introducing monomers bearing functional groups during the polymerization reaction.
• these polar groups are capable of interacting with the TP sc polymer by creating a weak bond on the surfaces of the TP sc polymer powder, for example, of the hydrogen type, Van der Waals which makes it possible to improve the cohesion of the powder and to increase the hardness of the powder bed, in particular at the construction temperature.
• the wax used in the context of the invention has an acid number ranging from 2 to 100, preferably 3 to 90 mg KOH / g, for example ranging from 2 to 10, or from 10 to 20, or from 20 to 50, or from 50 to 90 mg KOH / g.
• an acid number ranging from 2 to 100, preferably 3 to 90 mg KOH / g, for example ranging from 2 to 10, or from 10 to 20, or from 20 to 50, or from 50 to 90 mg KOH / g.
• a TP sc polymer of the polyamide or PEBA type it has been observed that the higher the acid number of the wax, the stronger the cohesion of the powder bed for them. waxes having similar dropping points.
• the acid number was measured according to DIN EN ISO 2114 - November 2000, using a 50:50 v / v xylene / ethanol mixture as the titration solvent.
• the 1g wax sample was weighed in a 250ml Erlenmeyer flask and dissolved in 100ml of the hot xylene / ethanol mixture (about 90 ° C) on a magnetic stirrer.
• the sample was then placed on the magnetic stirrer of the titrimeter, the electrode was well immersed and the mixture was titrated with an ethanolic solution of KOH at a concentration of 0.1 M.
• the wax can be chosen from polyethylene and polypropylene waxes, polytetrafluoroethylene waxes, ketone waxes, acid waxes, partially esterified acid waxes, waxes. acid anhydride, ester waxes, aldehyde waxes, amide waxes, their derivatives and mixtures thereof, preferably polyethylene and polypropylene waxes, acid waxes, waxes of partially esterified acids, acid anhydride waxes, ester waxes, amide waxes, their derivatives and / or mixtures thereof.
• Waxes can typically be dry or melt mixed.
• the polyolefin waxes can be homopolymers of ethylene and / or propylene and / or 1 -butene.
• Polyolefin waxes can be copolymers of two or more olefins (eg, polymers of mixtures of ethylene, propylene and / or 1 -butene). They can also be copolymers of ethylene and of propylene.
• the polyolefins can be linear or branched polyolefins having from 20 to 200 carbon atoms, and preferably from 40 to 100 carbon atoms. They can also be substituted by aliphatic and / or aromatic groups.
• polystyrene examples include 1-hexene, 1-octene or 1-octadecene, styrene.
• a polyolefin wax used in the context of this invention is wax "Crayvallac IL ⁇ / 7495 ®” marketed by Arkema.
• a polytetrafluoroethylene wax which can be used in the context of the invention is the "Ceridust 9202F®” wax sold by Clariant or the “Crayvallac WF-1000®” wax by Arkema.
• An acid wax which can be used in the context of the invention is the "Licowax S®” wax sold by Clariant.
• ester wax which can be used in the context of the invention is polyhydroxyalkanoate wax, for example, the “Ceraflour 1000®” wax sold from Byk, and the “Licowax OP®” wax sold from Clariant.
• the wax can be a wax derived from crude oil, such as paraffins.
• Paraffin waxes primarily contain straight chain hydrocarbons and may also contain branched hydrocarbons, such as isoparaffins and other branched materials, and cycloalkanes, such as cycloparaffins and other cyclic materials.
• the polyolefin waxes can be functionalized with acid anhydrides such as maleic anhydride.
• such a wax is the wax “Ceridust 802 (” marketed by the company CLARIANT.
• Amide waxes can be prepared by reacting a long chain carboxylic acid (typically a fatty acid) with an amine, diamine, or ammonia.
• a long chain carboxylic acid typically a fatty acid
• the amide wax comprises a diamide obtained from a diamine chosen from a C2 to C24 aliphatic diamine, a C6 to C18 cycloaliphatic diamine, a C6 to C24 aromatic diamine, or their mixtures.
• An aliphatic diamine can be linear or branched, preferably linear.
• suitable linear aliphatic amines are 1, 2-ethylenediamine, 1, 3-propylenediamine, 1, 4-tetramethylenediamine, 1, 5-pentamethylenediamine, 1, 6-hexamethylenediamine, 1, 8-octamethylenediamine, 1, 12-dodecamethylenediamine and their mixtures; preferably 1, 2-ethylenediamine, 1, 5-pentamethylenediamine and 1, 6-hexamethylenediamine.
• suitable branched aliphatic amines are 1, 2-propylenediamine, 2,2-dimethyl-1, 3-propanediamine, 2-butyl-2-ethyl-1, 5-pentanediamine and mixtures thereof.
• a cycloaliphatic diamine is a non-aromatic diamine comprising a ring, in particular a ring having 6 carbon atoms.
• a C6 to C18 cycloaliphatic diamine is a cycloaliphatic diamine comprising 6 to 18 carbon atoms.
• Suitable cycloaliphatic diamines are 1, 2-, 1, 3- or 1, 4-diaminocyclohexane, 2-methylcyclohexane-1, 3-diamine, 4-methylcyclohexane-1, 3-diamine, isophoronediamine, 1, 2-, 1, 3- or 1, 4- bis (aminomethyl) cyclohexane, diaminodecahydronaphthalene, 3,3'-dimethyl-4,4'-diaminodicyclohexylmethane, 4,4'-diaminodicyclohexylmethane, bis (aminomethyl) norbornane and mixtures thereof; preferably 1, 3- or 1, 4- bis (aminomethyl) cyclohexane, 1, 2-, 1, 3- or 1, 4-bis (aminomethyl) cyclohexane, isophorone diamine and 4,4'-diaminodicyclohexylmethane.
• An aromatic diamine is a diamine comprising an aromatic ring.
• a C6 to C24 aromatic diamine is an aromatic diamine comprising 6 to 24 carbon atoms.
• suitable aromatic diamines are meta- and para-phenylenediamine, meta- and para-xylylenediamine, meta- and para-toluylenediamine, 3,4'-diaminodiphenylether, 4,4'-diaminodiphenylether, 4,4'- diaminodiphenylmethane and mixtures thereof; preferably meta- and para- xylylenediamine.
• the amide wax comprises a diamide obtained with at least one diamine chosen from a C2 to C24 aliphatic diamine, in particular a linear C2 to C18 aliphatic diamine, more particularly a linear C2 to C12 aliphatic diamine, more particularly still 1, 2-ethylenediamine, 1, 5-pentamethylenediamine or 1, 6-hexamethylenediamine.
• the amide wax comprises a diamide obtained with at least one C2 to C36 carboxylic acid.
• the diamide can be obtained with a mixture of C2 to C36 carboxylic acids.
• the carboxylic acid can be linear or branched, preferably linear.
• the carboxylic acid can be saturated or unsaturated, preferably saturated.
• the carboxylic acid can be unsubstituted or substituted, especially hydroxylated.
• a hydroxylated carboxylic acid is a carboxylic acid substituted with one or two hydroxyl groups, preferably with one hydroxyl group.
• the carboxylic acid can be a hydroxylated carboxylic acid optionally mixed with an unsubstituted carboxylic acid.
• hydroxy carboxylic acids are 12-hydroxy stearic acid (12-HSA), 9-hydroxy stearic acid (9-HSA), 10-hydroxystearic acid (10-HSA), 14-hydroxy eicosanoic acid (14 -HEA), 2,2- bis (hydroxymethyl) propionic acid, 2,2-bis (hydroxymethyl) butyric acid, hydroxy-acetic acid (or glycolic acid), 2-hydroxy propionic acid (lactic acid), 2-hydroxy acid -3- (3-pyridyl) propionic, 3-hydroxy butyric acid, 2-hydroxy butyric acid, 2-methyl-2-hydroxy butyric acid, 2-ethyl-2-hydroxy butyric acid, hydroxy pentanoic acid, hydroxy hexanoic acid, hydroxy heptanoic acid, hydroxy octanoic acid, hydroxy nonanoic acid, hydroxy decanoic acid and mixtures thereof; preferably 12-hydroxy stearic acid or a binary or ternary mixture of 12-hydroxy stearic acid with the other
• Suitable examples of unsubstituted carboxylic acids are acetic acid, propionic acid, butyric acid, pentanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid, stearic acid, eicosanoic acid, palmitoleic acid, oleic acid, 11-eicosenoic acid, erucic acid, nervonic acid, linoleic acid, ⁇ -linolenic acid, g-linolenic acid, dihomo- g-linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, and mixtures thereof; preferably decanoic acid.
• the amide wax comprises a diamide obtained with at least one carboxylic acid chosen from a C2 to C22 carboxylic acid, in particular a C2 to C22 hydroxylated carboxylic acid and optionally an unsubstituted C2 to C22 carboxylic acid. , more particularly a C12 to C20 hydroxylated carboxylic acid and optionally an unsubstituted C2 to C14 carboxylic acid.
• the amide wax comprises a diamide obtained by reaction between 1, 2-ethylenediamine or 1, 6-hexamethylene diamine and 12-hydroxystearic acid or optionally decanoic acid.
• Amide waxes can be compounds prepared by reacting ammonia or ethylenediamine with saturated and / or unsaturated fatty acids such as stearic acid, tallow fatty acid, palmitic acid, erucic acid.
• Amide waxes also can include amide compounds such as N, N'-ethylenedistearamide.
• such a wax is wax "Crayvallac WN1265 ®” marketed by Arkema.
• the polyolefin waxes can be mixed with amide waxes.
• waxes are: wax “Crayvallac WN1 135" sold by the company Arkema, wax “Ceridust ® 9615A” - a mixture of polyethylene wax and amide wax, available from Clariant.
• the wax can be chosen from fatty acid derivatives, such as partially or fully esterified fatty acids.
• they are fatty acids comprising at least 10 carbon atoms, preferably 16 to 60 carbon atoms, and more preferably 24 to 36 carbon atoms.
• they are saturated alkanemonocarboxylic acids, preferably linear, such as montanic acid.
• this type of wax mention may be made of the “Ceridust 5551®” wax sold by the company CLARIANT.
• the wax does not include fatty acid salts comprising at least 10 carbon atoms, preferably from 16 to 60 carbon atoms, and more preferably from 24 to 36 carbon atoms (also called of "Metallic soaps").
• fatty acid salts comprising at least 10 carbon atoms, preferably from 16 to 60 carbon atoms, and more preferably from 24 to 36 carbon atoms (also called of "Metallic soaps").
• they are the salts of saturated alkanemonocarboxylic acids, preferably linear, such as montanic acid and stearic acid.
• these are the calcium and / or sodium and / or magnesium salts.
• such waxes are wax "Licomont NAV101 ®" marketed by Clariant, calcium stearate or magnesium.
• the wax in the composition of the invention is nonionic.
• the wax can be a mixture of the ester wax functionalized with an alcohol. Mention may be made of the “Licolub WE 40®” wax sold by the company CLARIANT.
• the vegetable waxes can comprise, for example, derivatives of castor oil, functionalized or not.
• wax derived from castor oil include wax "Crayvallac PC ®” marketed by Arkema, and wax “Jagrowax 100 *” sold by Jayant Agro-Organics.
• the wax has a dropping point higher than the crystallization temperature (Te) of the TP sc polymer.
• the wax according to the invention can have a dropping point greater than the Tm of the TP sc polymer of at most 30 ° C, and preferably at most 20 ° C.
• this difference can be from 1 to 5 ° C; or from 5 to 10 ° C; or from 10 to 15 ° C; or from 15 to 20 ° C; or from 20 to 25 ° C; or 25 to 30 ° C.
• the wax can have a dropping point of 60 to 180 ° C, and preferably 80 to 175 ° C.
• this dropping point can be 60 to 65 ° C; or from 65 to 70 ° C; or from 70 to 75 ° C; or from 75 to 80 ° C; or 8 (& 85 ° C; or 85 to 90 ° C; or 90 to 95 ° C; or 95 to 100 ° C; or 100 to 105 ° Q or 105 to 110 ° C; or 110 to 115 ° C; or from 115 to 120 ° C; or from 120 to 125 ° Q or from 125 to 130 ° C; or from
• the present invention proposes to use a particular wax, the dropping point of which is greater than the Te of the polymer TP sc.
• the wax is in the molten state or at least partially molten at the temperature of the powder bed, and can increase the cohesion of the TP sc polymer powders by a kind of sticking, which results in increasing the rigidity of the powder bed and prevents the part from sinking into the bed.
• the wax's dropping point is greater than the Te of the TP sc polymer by at least 5 ° C, preferably by at least 10 ° C, by [Deference by at least 15 ° C, and further by preferably at least 20 ° C.
• this temperature difference can be 5 to 10 ° 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 from 30 to 35 ° C; or 35-40 ° C; or from 40 to 45 ° C; or 45 to 50 ° C.
• the composition of the powder is semi-crystalline, that is, the transformation into powder of the TP sc polymer and the preparation of the powder composition does not affect the semi-crystalline character of the TP sc polymer as defined. above.
• composition according to the invention may comprise the TP sc polymer (s) in a proportion by weight preferably greater than or equal to 80%, or to 81%, or to 82%, or to 83%, or to 84%. , or 85%, or 86%, or 87%, or 88%, or 89%, or 90%, or 91%, or 92%, or 93%, or 94% , or 95%, or 96%, or 97%, or 98%, or 99%, or 99.1%, or 99.2%, or 99.3%, or 99.4%, or 99.5%, or 99.6%, or 99.7%, or 99.8%, or 99.9%, or 99.91%, or 99.92%, or 99.93%, or 99 , 94%, or 99.95%, or 99.96%, or 99.97%, or 99.98%, or 99.99%.
• the TP sc polymer particles can have a Dv50 size of 40 to 150 ⁇ m, and preferably 50 to 100 ⁇ m.
• the size Dv50 of the TP sc polymer particles can be 40-45 ⁇ m; or from 45 to 50 ⁇ m; or from 50 to 55 ⁇ m; or from 55 to 60 ⁇ m; or from 60 to 65 ⁇ m; or from 65 to 70 ⁇ m; or from 70 to 75 ⁇ m; or from 75 to 80 ⁇ m; 80 to 85 ⁇ m; or from 85 to 90 ⁇ m; or from 90 to 95 ⁇ m; or from 95 to 100 ⁇ m; or from 100 to 105 ⁇ m; or from 105 to 110 ⁇ m; or from 110 to 115 ⁇ m; or from 115 to 120 ⁇ m; or from 120 to 125 ⁇ m; or from 125 to 130 ⁇ m; or from 130 to 135 ⁇ m; or from 135 to 140 ⁇ m; or from 140 to 145 ⁇ m; or from or from 40-
• the composition comprises a wax at a content of 0.1 to 20% by weight of the total composition, preferably 0.5 to 10%, and more preferably 0.5 to 5% by weight.
• this content can be from 0.1 to 0.2%; or from 0.2 to 0.3%; or from 0.3 to 0.4%; or from 0.4 to 0.5%; or from 0.5 to 1%; or from 1 to 2%; or from 2 to 4%; or from 4 to 6%; or from 6 to 8%; or from 8 to 10%; or from 10 to 12%; or from 12 to 14%; or from 14 to 16%; or from 16 to 18%; or from 18 to 20%.
• the wax can be present in the composition in the form of wax particles.
• the wax particles have an average size (Dv50) of 1 to 30 ⁇ m, preferably 1 to 20 ⁇ m, and more preferably 5 to 15 ⁇ m.
• a wax is chosen whose average size (Dv 50) is smaller than that of the TP sc polymer in the composition.
• the wax can also have a Dv90 size of less than 50 ⁇ m, and preferably less than 20 ⁇ m.
• the size Dv90 of the wax particles can be 5 to 20 ⁇ m; or from 5 to 15 pm.
• the Dv50 corresponds to the particle size threshold for which 50% of the particles (by volume) have a size below the threshold, and 50% of the particles (by volume) have a size above the threshold;
• the Dv90 corresponds to the particle size threshold for which 90% of the particles (by volume) have a size below the threshold, and 10% of the particles (by volume) have a size above the threshold.
• the Dv50 and the Dv90 are measured according to the ISO 9276 standard - parts 1 to 6: “Representation of data obtained by particle size analysis”. It is possible to use, for example, a laser particle size analyzer (Sympatec Helos) and software (Fraunhofer) to obtain the volumetric distribution of a powder and to deduce the Dv50 and the Dv90 therefrom.
• the wax is present in the composition in the form of a coating at least partially covering the particles of the TP sc polymer powder.
• composition according to the invention comprises one or more flow agents.
• flow agent is meant an agent which improves the flowability as well as the leveling of the powder of semi-crystalline thermoplastic polymers during the sintering process.
• wax in the composition of the invention proves to be particularly advantageous in these cases: it makes it possible to widen the working window and also to avoid the problem of the cohesion of the bed, thus making it possible to carry out a construction. more easily.
• the flow agent can be chosen from those commonly used in the field of sintering powders of TP sc polymers. It is for example chosen from: silicas, in particular precipitated silicas, hydrated silicas, vitreous silicas, fumed silicas, pyrogenic silicas, vitreous oxides, in particular vitreous phosphates, vitreous borates, alumina, such as amorphous alumina, Ti02, calcium silicates, magnesium silicates, such as talc, mica, kaolin, attapulgite, and mixtures thereof.
• silicas in particular precipitated silicas, hydrated silicas, vitreous silicas, fumed silicas, pyrogenic silicas, vitreous oxides, in particular vitreous phosphates, vitreous borates, alumina, such as amorphous alumina, Ti02, calcium silicates, magnesium silicates, such as talc, mica, kaolin, attapulgite,
• the flow agent is generally present in the composition at a content of less than or equal to 5% by mass of the total composition, preferably less than or equal to 3%. Typically this content can be 0.1 to 2.5%, for example 0.1 to 2%, preferably 0.5 to 2%, or 0.5 to 1.5%.
• the flow agent is generally in powder form, preferably substantially spherical in shape.
• the flow agent in the composition of the powder may be in the form of particles having an average size (Dv50) less than or equal to 20 ⁇ m, preferably less than or equal to 15 ⁇ m, preferably less than or equal to 10 ⁇ m, and more preferably less than or equal to 1 ⁇ m.
• Dv50 size of the flow agent particles can be 10nm to 100nm, 100nm to 1 ⁇ m, 1 ⁇ m to 20 ⁇ m.
• composition according to the invention can comprise any type of additive suitable for the powders of TP sc polymers used in sintering: in particular additives (in powder form or not) which contribute to improving the properties of the powder for its use in technology. agglomeration and / or additives making it possible to improve the properties, for example, the mechanical properties (for example modulus, elongation at break, impact resistance) or else the aesthetic properties (color) of the three-dimensional parts manufactured.
• additives in powder form or not
• additives for example, the mechanical properties (for example modulus, elongation at break, impact resistance) or else the aesthetic properties (color) of the three-dimensional parts manufactured.
• the composition according to the invention can comprise mineral additives, for example, carbonate minerals, in particular calcium carbonate, magnesium carbonate, dolomite, calcite, barium sulphate, sulphate.
• carbonate minerals in particular calcium carbonate, magnesium carbonate, dolomite, calcite, barium sulphate, sulphate.
• carbonate minerals in particular calcium carbonate, magnesium carbonate, dolomite, calcite, barium sulphate, sulphate.
• the composition is devoid of mineral additives and organic additives.
• the additives of the aforementioned type can be present in the composition of the powder (including those present where appropriate in the TP sc polymer powders) at a mass content of less than or equal to 60%, preferably less than or equal to 30%, more preferably less than or equal to 1%. For example at a mass content of 0.05 to 60%; or from 1 to 30%; or from 1 to 20%; or from 1 to 10%.
• the composition of the invention can also comprise dyes, pigments for coloring, pigments for infrared absorption, anti-fire additives, anti-oxygen stabilizers, light stabilizers, anti-shock agents, anti-static agents, flame retardants, and mixtures thereof. These additives are preferably in the form of a powder with a Dv50 of less than 20 ⁇ m. These additives can be present in the composition at a content of 0.05 to 5%.
• the additives can be mixed with the TP sc polymer before and / or after the grinding step described above.
• composition according to the invention comprises powders of semi-crystalline thermoplastic polymer and at least one wax.
• the process for preparing the composition of the present invention comprises a step where the TP sc polymer is contacted with the wax, and optionally a flow agent.
• TP sc polymers which can be used in the context of the invention are for the most part commercially available, in particular in the form of granules, scales or coarse powder, which can be easily converted into powder by means of known methods.
• TP sc polymer powder can be obtained by a grinding process.
• the TP sc polymer brought into contact with the wax is in powder form; alternatively, in the form of granules, scales or coarse powder, for example having a Dv50 size greater than 250 ⁇ m (In this case, a grinding and / or sieving step can be carried out.)
• the contacting of the TP sc polymer with the wax is carried out by mixing dry, that is to say in the absence of solvent.
• the placing of the TP sc polymer into contact with the wax is carried out according to the following steps:
• the suitable solvent may be a solvent known to those skilled in the art to be able to dissolve a wax, for example, acetone, ethanol and / or a solvent comprising water and a surfactant.
• the preparation process may include a grinding step in order to obtain a TP sc polymer powder of the desired particle size.
• the grinding step can be carried out before and / or after contacting the TP sc polymer with the wax.
• the grinding is cryogenic grinding known to those skilled in the art
• the TP sc polymer (or the mixture of TP sc polymer and wax) is cooled to a temperature below the transition temperature.
• glassy of the polymer TP sc. This temperature can be 10 to 50 ° C lower than the glass transition temperature of the TP sc polymer.
• the mixture can be cooled to a temperature less than or equal to -10 ° C, preferably less than or equal to -50 ° C, and more preferably less than or equal to -80 ° C.
• the cooling of the TP sc polymer can be carried out for example with liquid nitrogen, or with liquid carbon dioxide or with dry ice, or with liquid helium .
• the grinding step can be carried out in a counter-rotating pin mill (pin mill), a hammer mill (hammer mill) or in a whirl mill.
• the method for preparing the composition according to the invention can then comprise a sieving step.
• the sieving can be carried out on a sieve.
• the preparation process can include a selection step to obtain the desired particle size profile.
• the powders can be dispersed by a selection wheel and carried by classifying air. Dust entrained in the air is fed through a support wheel and discharged through a first outlet. The coarse product is rejected by a classification wheel and transported to a second outlet.
• the selector can include several successive wheels working in parallel.
• the TP sc polymer (or the mixture of TP sc polymer and wax) is contacted with the additives in powder form. , (ie in the form of a simple mixture) before or after the grinding and / or sieving step.
• certain specific additives such as mineral additives, can be incorporated into the TP sc polymer powders by compounding, in particular at the stage of the manufacture of the TP sc polymer granules intended to be ground.
• TP sc polymers for example, polyamides
• a dissolution-precipitation process can be envisaged for the preparation of powder.
• the wax can be introduced during the dissolution-precipitation process.
• composition as described above, is used for a method of constructing layer-by-layer 3D articles by sintering caused by electromagnetic radiation, for example infrared, ultraviolet, or preferably laser radiation.
• a thin layer of powder is deposited on a horizontal plate maintained in an enclosure heated to a temperature called the construction temperature.
• the term "build temperature” (also called “bed temperature”) refers to the temperature to which the powder bed, of a constituent layer of a three-dimensional object under construction, is heated during the layer-by-layer sintering process. powder layer. This temperature may be lower than the melting temperature of the TP sc polymer of less than 50 ° C, from preferably less than 40 ° C, and more preferably about 20 ° C.
• 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). Then, the horizontal plate is lowered by an amount corresponding to the thickness of a powder layer, and a new layer is deposited. The electromagnetic radiation provides the energy necessary to sinter the powder particles according to a geometry corresponding to this new slice of the object and so on. The procedure is repeated until the object has been manufactured.
• the layer of powder deposited on a horizontal plate may have a thickness of 20 to 200 ⁇ m, and preferably of 50 to 150 ⁇ m.
• the layer of agglomerated material after sintering may have a thickness of 10 to 150 ⁇ m, and preferably 30 to 100 ⁇ m.
• the composition of the invention is used in a selective laser sintering process (SLS).
• SLS selective laser sintering process
• the composition can also be used in a sintering process of the MJF (Multi Jet Fusion) and HSS (High Speed Sintering) type.
• the powder composition according to the invention thus makes it possible to manufacture three-dimensional articles of good quality, having good mechanical properties and precise and well-defined dimensions and contours.
• the powder composition as described above, can be recycled and reused in several successive constructions. It can, for example, be used as it is or as a mixture with other powders, whether or not they are recycled.
• PEBA copolymers are optionally mixed with a flow agent (silica) at a rate of 1% (for polymer A), 0% (for polymer B) by weight and optionally with a wax at a rate of 1. % in weight.
• a flow agent silicon
• a wax at a rate of 1. % in weight.
• compositions 1 to 11 were used for the manufacture of three-dimensional articles.
• compositions 2 to 6 and 8 it was found that the presence of wax having a dropping point greater than the Te of the polymer allows the composition to pass through a sintering machine so as to obtain 3D articles (compositions 2 to 6 and 8).
• compositions 1 and 7 The absence of wax does not allow the composition to pass through the sintering machine (compositions 1 and 7).
• composition 9 it was found that when the dropping point of the wax is lower than the Te of the polymer, the manufacture of 3D articles was not possible.
• the wax-free compositions 10 and 11 it was found that the use of salts does not make it possible to increase the working window or to ensure the cohesion of the bed, the manufacture of 3D articles was not possible. Not possible.
• Example 2 Example 2
• a PA12 powder is mixed with silica at a rate of 0.15%. This powder has a Tm equal to 180 ° C and a Te equal to 147 ° C measured according to the ISO 11357 standard.
• compositions 1 and 2 These compositions were used for the manufacture of three-dimensional articles.
• the wax used is a polyhydroxyalkanoate (PHA), a product marketed under the trademark Ceraflourl 000® from BYK.
• PHA polyhydroxyalkanoate
• Ceraflourl 000® a product marketed under the trademark Ceraflourl 000® from BYK.
• the working window is determined for compositions 1 and 4.
• Composition 2 allows construction of three-dimensional objects over a wider temperature range, so this formulation has a larger working window.

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