Process for producing a three-dimensional object

Patent metadata

Field	Value
Publication number	US-11732133-B2
Application number	US-201816607473-A
Country	US
Kind code	B2
Filing date	Apr 25, 2018
Priority date	Apr 25, 2017
Publication date	Aug 22, 2023
Grant date	Aug 22, 2023

Abstract

A process for producing a three-dimensional object by selectively layer-by-layer solidification of a powdery material layer at the locations corresponding to the cross-section of the object in a respective layer by exposure to electromagnetic radiation. The powdery material comprises at least one polymer which is obtainable from its melt only in substantially amorphous or completely amorphous form, or a polyblend which is obtainable from its melt only in substantially amorphous or completely amorphous form. The powdery material has a specific melting enthalpy of at least 1 J/g.

First claim

The invention claimed is:

1. A process for producing a three-dimensional object, the process comprising:
selectively solidifying, layer-by-layer, a powdery material at locations corresponding to a cross-section of the object in a respective layer by exposure to electromagnetic radiation,
wherein the powdery material comprises at least one polymer which is obtainable from its melt only in substantially amorphous or completely amorphous form, or a polyblend which is obtainable from its melt only in substantially amorphous or completely amorphous form;
wherein the powdery material has a specific melting enthalpy of at least 1 J/g;
wherein the powdery material has a powder distribution with (i) a d90 value of <150 μm and (ii) a mean particle size (d50 value) of at least 20 μm; and
wherein the powdery material has a bulk density of at least 0.35 g/cm 3 .

2. The process according to claim 1 ,
wherein the powdery material comprises at least one of polymers selected from the group consisting of polyetherimides, polycarbonates, polyphenylene sulfones, polyphenylene oxides, polyethersulfones, acrylonitrile-butadiene-styrene copolymers (ABS), acrylonitrile-styrene-acrylate copolymers (ASA), polyvinyl chloride, polyacrylates, polyesters, polyamides, polyaryletherketones, polyethers, polyurethanes, polyimides, polyamidimides, polysiloxanes, polyolefins and copolymers which comprise at least two different repeating units of the abovementioned polymers, and/or at least one polyblend based on the abovementioned polymers and/or copolymers.

3. The process according to claim 1 ,
wherein the powdery material is preheated before being solidified by exposure to electromagnetic radiation; and
wherein the processing temperature is
(i) at least 10° C. above a glass transition temperature of the at least one polymer or copolymer or polyblend; and/or
(ii) at most at the maximum processing temperature at which the powdery material refrains from sticking together.

4. The process according to claim 1 , wherein the powdery material has additionally one or more of the following features:
(iii) the mean particle size (d50 value) is at most 100 μm;
(iv) the powdery polymer material has a sphericity greater than 0.8;
(v) the powdery polymer material has a distribution width ((d90−d10)/d50) of less than 3;
(vi) the powdery polymer material has a bulk density of at most 0.70 g/cm 3 ,
(vii) the powdery polymer material has a melt viscosity, determined by ISO-1133 at 5 kg load and a test temperature in a temperature range of 50-80° C. above the highest melting temperature, of at least 10 cm 3 /10 min and/or at most 150 cm 3 /10 min.

5. The process according to claim 1 ,
wherein the powdery material has a polyetherimide content of at least 1% by weight and/or of at most 90% by weight,
wherein the polyetherimide content respectively refers to a total content of polymers in the powdery material without taking additives and fillers into account, and wherein, in a case of the use of a polyetherimide-containing polyblend, a polyetherimide proportion by weight of a polyetherimide-containing polyblend is included in the polyetherimide content.

6. The process according to claim 1 ,
wherein the powdery material comprises a polyetherimide selected from the group consisting of:

a polyetherimide having repeating units A according to a formula

and repeating units B according to a formula

where a proportion of repeating units A and a proportion of repeating units B, respectively based on a total content of A and B, respectively is at least 1% and/or at most 99%,
wherein R 1 and R 3 are moieties which are different from each other and which are independently selected from the group consisting of

and
wherein R 2 and R 4 are moieties which are different from each other and which are independent of each other and independent of R 1 and R 3 selected from the group consisting of

a polyetherimide having repeating units according to a formula

wherein R 5 is a moiety selected from the group consisting of

and wherein R 6 is a moiety independent of R 5 selected from the group consisting of

a polyetherimide having repeating units C according to a formula

and repeating units D according to a formula

wherein a proportion of the repeating units C and a proportion of the repeating units D, respectively based on a total content of C and D, respectively is at least 1% and/or at most 99%,
wherein R 7 is a moiety selected from the group consisting of

and
wherein R 8 is a moiety independent of R 7 selected from the group consisting of

7. The process according to claim 1 , wherein
the powdery material comprises a polyetherimide having repeating units according to a formula

wherein R 5 is a moiety selected from the group consisting of

and wherein R 6 is a moiety independent of R 5 selected from the group consisting of

wherein the powdery material comprises polyetherimide having repeating units according to a formula

or repeating units according to a formula

or repeating units according to a formula

8. The process according to claim 1 , wherein the powdery material comprises a polyetherimide-polysiloxane copolymer having repeating units E according to a formula

and repeating units F according to a formula

wherein a proportion of the repeating units E and the proportion of the repeating units F, respectively based on the total content of E and F, respectively is at least 1% and/or at most 99%.

9. The process according to claim 1 , wherein the powdery materi

Assignees

• Eos Gmbh Electro Optical Systems

Inventors

• Pfister Andreas
• Hotter Andreas
• Keller Peter
• Freihart Karl

Classifications

• C08L79/08 Primary

  Polyimides; Polyester-imides; Polyamide-imides; Polyamide acids or similar polyimide precursors · CPC title

• B29C64/153

  using layers of powder being selectively joined, e.g. by selective laser sintering or melting · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• C09D11/037

  characterised by the pigment · CPC title