阅读说明：本技术 盐化的单体粉末及其在粉末团聚方法中的用途 (Salted monomer powder and its use in a powder agglomeration process ) 是由 G.卡米奇 于 2020-02-13 设计创作，主要内容包括：本发明涉及至少一种盐化的单体粉末在增材制造方法中的用途。(The invention relates to the use of at least one salified monomer powder in an additive manufacturing process.)

1. Use of at least one salified monomer powder in an additive manufacturing process.

2. The use as claimed in claim 1, wherein the volume median diameter D50 of the salted monomer powder is less than or equal to 500 μm.

3. The use as claimed in claim 1 or 2, wherein the volume median diameter D50 of the salted monomer powder is between 5 μm and 250 μm.

4. Use according to any one of claims 1to 3, wherein the salified monomer is a salt of at least one amino acid or a salt of at least one dicarboxylic acid and at least one diamine.

5. Use according to claim 4, wherein the amino acid is 11-aminoundecanoic acid or 12-aminododecanoic acid.

6. The use as claimed in claim 4, wherein the dicarboxylic acid is selected from terephthalic acid, 2, 6-naphthalenedicarboxylic acid, biphenyl-4, 4' -dicarboxylic acid, isophthalic acid, naphthalenedicarboxylic acid, oxalic acid, 1, 4-succinic acid, 1, 6-adipic acid, 1, 8-suberic acid, cyclohexanedicarboxylic acid, sebacic acid, azelaic acid, dodecanedioic acid, and tetradecanedioic acid and cyclohexanedicarboxylic acid, or combinations thereof.

7. The use of claim 4, wherein the diamine is selected from the group consisting of 1, 2-ethylenediamine, 1, 3-propylenediamine, 1, 4-butylenediamine, 1, 5-pentylenediamine, 1, 6-hexylenediamine, and 1, 4-cyclohexyldiamine, 1, 7-heptylenediamine, 1, 8-octylenediamine, 1, 9-nonylenediamine, 1, 10-decyldiamine, 1, 11-undecylenediamine, 1, 12-dodecylenediamine, p-phenylenediamine, m-xylylenediamine, and p-xylylenediamine, or a combination thereof.

8. Method of additive manufacturing of an article, wherein at least one salified monomer powder as defined in claims 1to 7 is used as starting material.

9. The method of claim 8 wherein the salted monomer powder is placed in a chamber heated to a temperature less than or equal to the melting temperature of the salted monomer powder.

10. The method of claim 8 or 9, wherein the salted monomer powder is placed in a chamber heated to a temperature between 150 ℃ and 175 ℃.

11. The process of any one of claims 8 to 10, comprising the step of polymerizing the salted monomer powder.

12. The method of claim 11, further comprising the step of 3D construction.

13. The method of claim 12, wherein the step of polymerizing the salted monomer powder and the step of 3D building are performed simultaneously.

14. The method of any one of claims 8 to 13, wherein once the article is manufactured, it is separated from the salted monomer powder, which is recovered and reused in the method of additive manufacturing of the article.

15. 3D printed product manufactured using at least one salified monomeric powder as defined in any one of claims 1to 7.

16. The 3D printed product according to claim 15, manufactured according to the additive manufacturing method as defined in claims 8 to 14.

Technical Field

The present invention relates to salted monomer powders and their use in powder agglomeration processes.

Background

The technique of agglomerating polyamide powder under electromagnetic radiation (for example laser beams) is used for the manufacture of three-dimensional objects, such as prototypes and models, in particular in the fields of motor vehicles, navigation, aviation, aerospace, medical (prostheses, auditory systems, cell tissues, etc.), textiles, clothing, fashion, decoration, electronic housings, telephones, home automation, computing or lighting.

This technique also makes it possible to achieve fine and complex geometries that cannot be achieved by conventional molding techniques.

In the case of laser sintering, a thin layer of polyamide powder is deposited on a horizontal plate held in a chamber heated to a temperature between the crystallization temperature Tc and the melting temperature Tm of the polyamide powder. The laser makes it possible to melt (fuse) the powder particles at a plurality of points of the layer, which slowly crystallizes after passage of the laser in a geometry corresponding to the article, for example using a computer storing the shape of the 3D article and reproducing it in 2D plies (slice). Subsequently, the horizontal plate is lowered by a value corresponding to the thickness of the powder layer (for example between 0.05 and 2mm and generally of the order of 0.1 mm), then a new powder layer is deposited and the laser makes it possible to melt the powder particles in a shape corresponding to this new layer, which crystallizes slowly in a shape corresponding to the geometry of the article and so on. This procedure is repeated until the entire article is manufactured. An article surrounded by powder is obtained within the chamber. The unagglomerated parts thus remain in a powder state. After complete cooling, the article is separated from the powder, which can be reused for another run.

However, additive manufacturing methods using polyamide powders have several problems. In fact, the use of such polyamide powders results in the presence of porosity on the manufactured part and the article may need to be treated after its manufacture. Further, unused polyamide powder cannot always be recycled, since a portion of the powder often undergoes chemical evolution and begins to agglomerate during the laser sintering process.

There is therefore a need to provide a raw material alternative to polyamide powders which is easier to manufacture and which allows a good cohesion of the material in the agglomeration process.

Disclosure of Invention

The present invention results from the inventors' unexpected demonstration that salted monomer powders, in particular salted carboxylic acid and amine powders, are more readily available in powder form and used directly as starting materials in an agglomeration process than corresponding polyamides. The salted monomer powder provides very good cohesion of the material compared to conventional powders.

The present invention therefore relates to the use of at least one salified monomer powder in an additive manufacturing process.

The invention also relates to a method for additive manufacturing of an article, wherein the above-mentioned at least one salted monomer powder is used as a starting material.

The invention also relates to 3D printed products manufactured using the at least one salified monomer powder described above.

Detailed Description

In the present description of the invention, the following examples are included, D50, also referred to as "volume median diameter", corresponding to the value of the particle size that divides the population of particles examined exactly in half. D50 is based on the standard ISO 9276-parts 1to 6: "retrieval of results of particle size analysis". In the present description, a laser particle size analyzer (Sympatec Helos) and software (Fraunhofer) were used to obtain the particle size distribution of the powder and to derive therefrom D50.

Analysis of the thermal properties of polyamides, according to the standard ISO 11357-3 "Plastics-Differential Scanning Calibration (DSC) Part 3: determination of temperature and enthalpy of trading and crystallization "by DSC. The temperatures to which the invention herein more particularly relates are the first heat melting temperature (Tm1), the crystallization temperature (Tc) and the enthalpy of fusion.

Salted monomer powder

The salified monomer powder according to the invention can be formed from at least one diamine and at least one dicarboxylic acid or at least one amino acid.

According to one embodiment, the salified monomers are salts of at least one amino acid or of at least one dicarboxylic acid and at least one diamine.

The monomer powder according to the invention may comprise two or more dicarboxylic acids. The dicarboxylic acids according to the invention may be aliphatic, aromatic or mixtures of aliphatic and aromatic acids.

Preferably, the aromatic dicarboxylic acid according to the present invention is selected from terephthalic acid, 2, 6-naphthalenedicarboxylic acid, biphenyl-4, 4' -dicarboxylic acid, isophthalic acid, naphthalenedicarboxylic acid, 5-hydroxyisophthalic acid, salts of 5-sulfoisophthalic acid, furandicarboxylic acid, or combinations thereof.

The aliphatic dicarboxylic acid according to the present invention may be a non-cyclic, linear or branched dicarboxylic acid, or a cyclic dicarboxylic acid, or a combination thereof. The aliphatic dicarboxylic acid according to the present invention may be an aliphatic dicarboxylic acid having 2 to 14 carbon atoms.

Preferably, the aliphatic dicarboxylic acid according to the present invention is selected from oxalic acid, 1, 4-succinic acid, 1, 6-adipic acid, cyclohexanedicarboxylic acid, 1, 8-suberic acid, azelaic acid, sebacic acid, dodecanedioic acid, and tetradecanedioic acid, or combinations thereof.

In one embodiment of the present invention, the dicarboxylic acid consists of:

(a) an aromatic dicarboxylic acid, and (b) optionally an aliphatic dicarboxylic acid, and (c) optionally other dicarboxylic acids.

The diamines according to the invention may consist of mixtures of two or more diamines. The diamines according to the invention may be aliphatic, arylaliphatic or mixtures thereof. Arylaliphatic diamines are diamines which: wherein each amine group is directly linked to an aliphatic moiety which is also linked to an aromatic moiety, such as m-xylylenediamine and p-xylylenediamine.

The aliphatic diamine can comprise a linear aliphatic diamine, a branched aliphatic diamine, or an alicyclic diamine, or a combination thereof. The aliphatic diamine preferably comprises a diamine having 2 to 15 carbon atoms. The aliphatic diamine of C2-C15 is selected from the group consisting of 1, 2-ethylenediamine, 1, 3-propylenediamine, 1, 4-butylenediamine, piperazine, 1, 5-pentylenediamine, 1, 6-hexylenediamine, methyl-1, 5-pentylenediamine, 1, 2-cyclohexyldiamine, 1, 3-cyclohexyldiamine, 1, 4-cyclohexyldiamine, 1, 7-heptylenediamine, 1, 8-octanediamine, 1, 3-bis (aminomethyl) cyclohexane, 1, 9-nonanediamine, trimethylhexanediamine, 1, 10-decanediamine, 1, 11-undecanediamine, 1, 12-dodecanediamine, 4' -methylenebis (dicyclohexylamine), 3' -dimethyl-4, 4' -diaminodicyclohexylmethane, p-phenylenediamine, m-xylylenediamine, and p-xylylenediamine, or combinations thereof.

Preferably, the diamine comprises a C4-C10 linear diamine, more particularly 1, 4-butanediamine, 1, 5-pentanediamine, methyl-1, 5-pentanediamine, 1, 6-hexanediamine, 1, 4-cyclohexanediamine, 1, 3-bis (aminomethyl) cyclohexane, and 1, 10-decanediamine, or a combination thereof.

In one embodiment of the invention, the salified monomer powder comprises at least one amino acid, for example 11-aminoundecanoic acid, 12-aminododecanoic acid, N-heptylaminoaundecanoic acid. Preferably, the amino acid is 11-aminoundecanoic acid.

The salified monomer powder according to the invention comprising at least one dicarboxylic acid and at least one diamine, or at least one amino acid, is also referred to as "ammonium carboxylate salt".

The salified monomer powder according to the invention is preferably obtained by contacting a dicarboxylic acid with a diamine or from an amino acid. The salified monomer powder according to the invention is preferably the product of a neutralization reaction between a dicarboxylic acid and a diamine (result).

Preferably, the ammonium carboxylate salt is formed by impregnating a diamine with a dicarboxylic acid powder. Preferably, the carboxylic acid powder is stirred at a temperature less than or equal to the melting temperature of the dicarboxylic acid. Also preferably, the carboxylic acid powder is stirred at a temperature below the melting temperature of the salt and above or equal to the melting temperature of the diamine.

Preferably, the reaction temperature is 40 ℃ below the melting temperature of the ammonium carboxylate salt, more preferably 60 ℃ below the melting temperature of the ammonium carboxylate salt.

Preferably, the reaction temperature is below 220 ℃, preferably between 100 ℃ and 210 ℃, more preferably between 130 ℃ and 150 ℃. The reaction temperature can also be between 0 ℃ and 20 ℃.

Preferably, the dicarboxylic acids used in the present invention have a melting point above 100 ℃.

Preferably, the diamines used in the present invention have a melting point between 25 ℃ and 200 ℃.

The stirring of the dicarboxylic acid powder can be carried out by any means known to those skilled in the art, such as mechanical stirring or gas flow stirring.

The diamine may be added to the dicarboxylic acid powder by any means known to those skilled in the art. For example, the diamine may be added to the dicarboxylic acid powder by spraying or dropping the diamine into the stirred dicarboxylic acid powder. Preferably, the diamine is added gradually to the dicarboxylic acid powder. Preferably, the addition rate of the diamine is 0.07 to 6.7 mass% per minute with respect to the total amount of diamine to be added.

The reaction may be carried out in the presence of water. Preferably, the amount of water is between 1 and 10 mass%, relative to the total amount of dicarboxylic acid powder and diamine. More preferably, the amount of water is less than or equal to 5 mass% with respect to the total amount of dicarboxylic acid powder and diamine. The water may be removed by evaporation during the formation of the salt.

A chain limiter or polymerization catalyst may be added to the dicarboxylic acid and diamine powders. The term "chain-limiting agent" is understood to mean an agent capable of blocking the end of the terminal functional groups of the polymer. Examples of such terminal blocking agents include acetic acid, lauric acid, benzoic acid, octylamine, cyclohexylamine, and aniline. Preferably, the chain limiter is added in an amount of 5 mol% or less with respect to the total number of moles of the dicarboxylic acid powder and the diamine.

Examples of the polymerization catalyst include phosphoric acid, phosphorous acid, hypophosphorous acid and salts of these acids. The amount of the polymerization catalyst used is preferably 2 mol% or less based on the total number of moles of the dicarboxylic acid powder and the diamine.

Additives may also be added to the powders of diamines and dicarboxylic acid salts according to the invention at any stage of the salt production. As examples of such additives, mention may be made of fillers or stabilizers, pigments, dyes, carbon black, carbon nanotubes, antioxidants, UV stabilizers, or plasticizers. The amount of the additive(s) used is preferably 20% by weight or less with respect to the total mass of the dicarboxylic acid powder and the diamine.

Preferably, the volume median diameter D50 of the particles of the salified monomer powder (also called "ammonium carboxylate salt") according to the invention is less than or equal to 500 μm. Preferably, the volume median diameter D50 of the particles of the salified monomer powder (also referred to as "ammonium carboxylate salt") is between 5 μm and 250 μm. It is also preferred that the volume median diameter D50 of the particles of the salified monomer powder (also called "ammonium carboxylate salt") is between 30 μm and 80 μm.

Examples of polyamides obtainable by polymerization of the monomer salt powder according to the invention include:

-PA 11: polyundecanamides, made from 11-aminoundecanoic acid;

-PA 12: polylauramides, made from 12-aminododecanoic acid;

-PA 4.6: polytetramethylene adipamide, manufactured from 1, 4-butanediamine and adipic acid;

-PA 6.6: polyhexamethylene adipamide, manufactured from hexamethylenediamine and adipic acid;

-PA 6.9: polyhexamethylene nonanoylamide, made from hexamethylenediamine and 1, 9-azelaic acid;

-PA 6.10: polyhexamethylene sebacamide, made from hexamethylenediamine and sebacic acid;

-PA 6.12: polyhexamethylene dodecanediamide, made from hexamethylenediamine and 1, 12-dodecanedioic acid;

-PA 10.10: polydecamethylene sebacamide, made from decamethylene diamine and sebacic acid;

-PA 10.12: polydecamethylene sebacamide, made from decamethylenediamine and 1, 12-dodecanedioic acid;

-PA 6. T: from 1, 6-hexanediamine and terephthalic acid;

-PA 4.T/6. T: from 1, 4-butanediamine, 1, 6-hexanediamine and terephthalic acid;

-PA 6.T/10. T: from 1, 6-hexanediamine, 1, 10-decanediamine and terephthalic acid;

-PA 4.T/10. T: from 1, 4-butanediamine, 1, 10-decanediamine and terephthalic acid;

-PA 6.6/6. T: made from hexamethylenediamine, adipic acid, 1, 6-hexamethylenediamine, and terephthalic acid;

-PA 4. T/DACH.T: from trans-1, 4-diaminocyclohexane, 1, 4-butanediamine and terephthalic acid;

-PA mxd.6: made from m-xylene diamine and adipic acid;

-PA mxd.10: made from m-xylene diamine and sebacic acid;

-PA bmacm.10: from bis (3-methyl-4-aminocyclohexyl) methane and sebacic acid;

-PA pacm.12: from p-aminocyclohexylmethane and dodecanedioic acid.

Use (use)

The invention relates to the use of the salted monomer powder according to the invention in an additive manufacturing process. Additive manufacturing process is understood to mean a process for manufacturing an article by agglomeration of salted monomer powder.

The use of the salted monomer powder according to the invention in agglomeration technology is particularly advantageous, since it provides a very good cohesion of the material compared to conventional powders.

The salted monomer powder according to the invention can be used in the case of a method for producing an article by melting caused by a laser beam (laser sintering), IR radiation or UV radiation. The laser sintering technique is described in particular in patent application EP 1571173.

Furthermore, the salified monomer powder according to the invention can also be used in composites, substrate coatings (stocks), transfer papers or in the manufacture of cosmetic compositions.

Additive manufacturing method

The invention also relates to a method for producing an article by agglomeration of the salified monomer powder according to the invention. Preferably, the salted monomer powder according to the invention is placed in a chamber heated to a temperature lower than or equal to the melting temperature of the salted monomer powder.

Preferably, the temperature of the chamber is between 110 ℃ and 175 ℃, more preferably, the temperature of the chamber is between 130 ℃ and 175 ℃. Even more preferably, the temperature of the chamber is between 150 ℃ and 175 ℃.

The method of manufacturing an article by agglomeration of the salted monomer powder according to the invention comprises the step of polymerizing the salted monomer powder. The method of manufacturing an article by agglomeration of salted monomer powder according to the invention further comprises the step of 3D building. Preferably, the step of polymerizing the salted monomer powder and the step of 3D building are performed simultaneously.

Preferably, the polymerization is continued in the molten state and in the solid state during the rest of the build.

The invention also relates to a method for producing an article by agglomeration of the salified monomer powder according to the invention, during which:

a. a thin layer (layer 1) of salted monomer powder according to the invention is deposited on a horizontal plate held in a chamber heated to a temperature below the melting temperature of the salted monomer powder;

b. the salified monomer powder (layer 1) is simultaneously melted, polymerized and agglomerated using a laser in a geometry corresponding to the article to be manufactured;

c. the horizontal plate is lowered by a value corresponding to the thickness of the layer of salified monomer powder according to the invention, and then a new layer of salified monomer powder according to the invention is deposited (layer 2);

d. simultaneously melting, polymerizing and agglomerating the salted monomer powder layer (layer 2) in a geometry corresponding to the new ply of the article to be manufactured;

e. the horizontal plate is lowered by a value corresponding to the thickness of the layer of salified monomer powder according to the invention, and then a new layer of salified monomer powder according to the invention is deposited (layer 3);

f. simultaneously melting, polymerizing and agglomerating the salted monomer powder layer (layer 3) in a shape corresponding to the new ply of the article to be manufactured;

g. repeating the previous steps until the article is completed;

h. the chamber is cooled, preferably slowly cooled.

After complete cooling, the object and powder are separated.

In one embodiment of the invention, unused salted monomer powder is recovered and reused in another run.

According to another aspect, the invention relates to a 3D printed product manufactured according to the additive manufacturing method described above.

The invention will be further illustrated in a non-limiting manner by means of the following examples.

Examples

The properties of the salted monomer powder according to the invention were investigated in a powder agglomeration process.

1. Salted monomer powder

A salified 11-aminoundecanoic acid powder (commercially available product sold by Arkema) was used, in which the volume median diameter D50 of the particles was 50 μm.

2. Use of

The powder was used in an LS machine using a temperature in the working and build chamber below 175 ℃ (so as not to melt the powder) but above 150 ℃ (to facilitate polymerization, even after laser passage).

A good quality part is obtained.