阅读说明：本技术 基于粉末的增材制造法 (Powder-based additive manufacturing method ) 是由 D.阿克滕 T.比斯根 M.凯斯勒 P.赖歇特 B.梅特曼 于 2018-12-13 设计创作，主要内容包括：增材制造法(3D-打印)使用具有可熔聚合物的颗粒。所述可熔聚合物包含热塑性聚氨酯聚合物,其具有160至270℃的熔融范围(DSC,差示扫描量热法；以5K/min的加热速率进行的第二次加热)和50或更高的根据DIN ISO 7619-1的肖氏D硬度,并且其具有在温度T下5至15 cm/10 min的根据ISO 1133的熔体体积速率(melt volume rate(MVR))和大于或等于90 cm3/10 min的在将该温度T提高20℃时的MVR变化。借助于该方法可得到的物体。(Additive manufacturing processes (3D-printing) use particles with fusible polymers. The fusible polymer comprises a thermoplastic polyurethane polymer having a melting range (DSC, differential scanning calorimetry; second heating at a heating rate of 5K/min) of 160 to 270 ℃ and a shore D hardness according to DIN ISO 7619-1 of 50 or more, and having a Melt Volume Rate (MVR) according to ISO 1133 of 5 to 15 cm/10 min at a temperature T and a MVR change at increasing the temperature T by 20 ℃ of greater than or equal to 90 cm fraction/10 min. An object obtainable by means of the method.)

1. Method for manufacturing an object, comprising the steps of:

-applying a layer of particles on a target surface;

-in the chamber, applying energy to selected parts of the layer corresponding to the object cross-section, such that particles in the selected parts are bound;

-repeating the applying and energy acting steps for a plurality of layers such that the bonded portions of adjacent layers are bonded to form the object;

wherein at least a portion of the particles have a fusible polymer;

it is characterized in that the preparation method is characterized in that,

the fusible polymer comprises a thermoplastic polyurethane polymer having

Melting range of 160 to 270 ℃ (DSC, differential scanning calorimetry; second heating at a heating rate of 20K/min) and

a Shore D hardness according to DIN ISO 7619-1 of 50 or more, and which has

5 to 15 cm/10 min Melt Volume Rate (MVR) and

more than or equal to 90 cm/10 min MVR change when the temperature T is increased by 20 ℃.

2. A method according to claim 1, wherein said applying energy to selected portions of said layer corresponding to the cross-section of the object, such that particles in the selected portions bond, comprises the steps of:

-irradiating a selected portion of the layer corresponding to the cross-section of the object with an energy beam such that the particles in the selected portion are bound.

3. A method according to claim 1, wherein said applying energy to selected portions of said layer corresponding to the cross-section of the object, such that particles in the selected portions bond, comprises the steps of:

-applying a liquid on selected parts of the layer corresponding to the cross-section of the object, wherein said liquid increases the energy absorption in the areas of the layer in contact therewith relative to areas not in contact with the liquid;

-irradiating the layer such that particles in regions of the layer in contact with the liquid do not bind to each other and particles in regions of the layer not in contact with the liquid do not bind to each other.

4. Method according to one of the preceding claims, characterized in that the applied particles are at least temporarily heated or cooled.

5. Process according to one of the preceding claims, characterized in that the thermoplastic polyurethane polymer has a Shore hardness (DIN ISO 7619-1) of 50 Shore D or more to 85 Shore D or less.

6. Process according to one of the preceding claims, characterized in that the fusible polymer comprises, in addition to the polyurethane polymer, a further polymer selected from the group consisting of: polyester, ABS, polycarbonate, or a combination of at least two thereof.

7. Process according to claim 6, characterized in that the meltable polymer is a blend comprising the polyurethane polymer and ABS, wherein the polyurethane polymer has a melting point (DSC, differential scanning calorimetry; second heating at a heating rate of 20K/min) of ≥ 160 ℃ and the proportion of ABS in the blend is ≥ 1% by weight and ≤ 40% by weight, based on the total weight of the blend.

8. Process according to claim 6, characterized in that the meltable polymer is a blend comprising the polyurethane polymer and a polyester, wherein the polyurethane polymer has a melting point (DSC, differential scanning calorimetry; second heating at a heating rate of 20K/min) of not less than 160 ℃ and the proportion of polyester in the blend is not less than 1% by weight to not more than 40% by weight, based on the total weight of the blend.

9. The process according to claim 6, wherein the meltable polymer is a blend comprising the polyurethane polymer and a polycarbonate based on bisphenol A and/or bisphenol TMC, wherein the polyurethane polymer has a melting point (DSC, differential scanning calorimetry; second heating at a heating rate of 20K/min) of 160 ℃ or more and the proportion of polycarbonate in the blend is 1% by weight or more and 40% by weight or less, based on the total weight of the blend.

10. Method according to one of the preceding claims, characterized in that at least a part of the particles are provided with the fusible polymer and further polymer and/or inorganic particles.

11. Method according to one of the preceding claims, characterized in that the formed object is subjected to a post-treatment selected from the group consisting of: mechanical smoothing of the surface, targeted local heating, heating of the entire object, targeted local cooling, cooling of the entire object, contacting of the object with water vapor, contacting of the object with vapors of organic solvents, irradiation of the object with electromagnetic radiation, immersion of the object in a liquid bath, or a combination of at least two of these.

12. Method according to one of the preceding claims, characterized in that after the step of applying a layer of particles on the target surface, the particles are at least partially suspended in a liquid phase.

13. Method according to one of the preceding claims, characterized in that the portion of the particles having fusible polymer is selected such that the particles retain their initial free flowability after storage at 150 ℃ for 8 hours under a nitrogen atmosphere.

14. Thermoplastic powder composition comprising powdered thermoplastic polyurethane, wherein the thermoplastic polyurethane is capable of being incorporated in a thermoplastic powder composition

d) Optionally a catalyst, which is added to the reaction mixture,

e) optionally auxiliaries and/or additives, which are,

f) optionally in the presence of one or more chain terminators,

obtained by the reaction of the following components:

a) at least one organic diisocyanate,

b) at least one compound having isocyanate group-reactive groups, having a number average molecular weight (Mn) of from 500 g/mol to 6000 g/mol and a number average functionality of all components under b) of from 1.8 to 2.5,

c) at least one chain extender having a molecular weight (Mn) of from 60 to 450 g/mol and a number average functionality of all chain extenders under c) of from 1.8 to 2.5,

characterized in that the thermoplastic polyurethane has a melting range (DSC, differential scanning calorimetry; second heating at a heating rate of 5K/min) of 160 to 270 ℃ and a Shore D hardness according to DIN ISO 7619-1 of 50 or more and has a Melt Volume Rate (MVR) according to ISO 1133 of 5 to 15 cm labor/10 min at a temperature T and a MVR change at an increase of the temperature T of 20 ℃ of > 90 cm labor/10 min,

for manufacturing an object in a powder based additive manufacturing method, in particular according to one of claims 1 to 13.

15. Object manufactured by a method according to one of claims 1 to 13 or by means of a composition according to claim 14.

Examples

The present invention is illustrated in more detail according to the following examples, but is not limited thereto. The weight percent data are based on the total amount of reactive organic ingredients (alcohol, amine, water, isocyanate) used.

The TPUs usable according to the invention and the TPUs used in the comparative examples are prepared according to two common process methods: prepolymer method and single/static mixer method (One-Shot/Statikmischer-Verfahre).

In the prepolymer process, the polyol or polyol mixture is preheated to 180 to 210 ℃, is charged in advance with a portion of the isocyanate, and is reacted at a temperature of 200 to 240 ℃. The twin-screw extruder used here has a rotational speed of about 270 to 290 revolutions/min. By this upstream partial reaction, a linear, slightly pre-extended prepolymer is obtained which, in the further course of the extruder, reacts completely with the remaining isocyanate and chain extender. This process is described, for example, in EP-A747409.

In the single/static mixer process, all the comonomer is homogenized at high temperature (over 250 ℃) in a short time (less than 20 s) by means of a static mixer or other suitable mixing device and then reacted and discharged by means of a twin-screw extruder at a temperature of 90 to 240 ℃ and a speed of 260 and 280 revolutions per minute. This process is described, for example, in application DE 19924089.

The thermomechanical properties of the resulting TPU were determined on injection molded sample plaques having a dimension of 50 mm by 10 mm by 1 mm. The measurement parameters for the DMA measurement according to DIN-EN-ISO 6721-4 are a frequency of 1 Hz and a heating rate of 2 ℃/min with a temperature interval of-150 ℃ to 250 ℃.