Mixture for use in a fused filament fabrication process

Patent metadata

Field	Value
Publication number	US-12168728-B2
Application number	US-201514806102-A
Country	US
Kind code	B2
Filing date	Jul 22, 2015
Priority date	Jul 22, 2014
Publication date	Dec 17, 2024
Grant date	Dec 17, 2024

Abstract

The use of a mixture (M) comprising
(a) from 40 to 70% by volume of an inorganic powder (IP) based on the total volume of the mixture (M), (b) from 30 to 60% by volume based on the total volume of the mixture (M) of a binder (B) comprising
(b1) from 50 to 96% by weight of at least one polyoxymethylene (POM) based on the total weight of the binder (B), (b2) from 2 to 35% by weight of at least one polyolefin (PO) based on the total weight of the binder (B), (b3) from 2 to 40% by weight of at least one further polymer (FP) based on the total weight of the binder (B)

in a fused filament fabrication process.

First claim

The invention claimed is:

1. A process for the production of a three-dimensional green body by a fused filament fabrication process, comprising: heating a mixture (M) to a temperature (T M ), and
depositing the mixture (M) into a build chamber using a layer-based additive technique to form the three-dimensional green body, wherein the temperature of the build chamber is in the range of from 50° to 80° C.,
wherein the mixture (M) comprises:
(a) from 40 to 70% by volume of an inorganic powder (IP) based on the total volume of the mixture (M),
(b) from 30 to 60% by volume based on the total volume of the mixlure (M) of a binder (B) consisting of
(b1) from 70 to 96% by weight of at least one polyoxymethylene (POM) based on the total weight of the binder (B),
(b2) from 2 to 15% by weight of at least one polyolefin (PO) based on the total weight of the binder (B),
(b3) from 2 to 26% by weight of at least one further polymer (FP) based on the total weight of the binder (B), wherein the at least one further polymer (FP) is polytetrahydrofuran,

said method further comprising, after the depositing, removing at least 95% by weight of component (b1), based on the total weight of component (b1), from the three-dimensional green body to form a three-dimensional brown body;
wherein the removal is carried out by acidic treatment and at a temperature in the range from 20 to 180° C.;
wherein the particle size of the inorganic powder (IP)) is from 0.1 to 80 μm.

2. The process according to claim 1 , wherein the mixture (M) further comprises as a component (c) from 0.1 to 5% by volume of at least one dispersant based on the total volume of the mixture (M).

3. The process according to claim 1 , wherein the inorganic powder (IP) is a powder of at least one inorganic material selected from the group consisting of a metal, a metal alloy and a ceramic material.

4. The process according to claim 1 , wherein component (b1) is a polyoxymethylene (POM) copolymer which is prepared by polymerization of
at least 50 mol-% of a formaldehyde source (b1a),
from 0.01 to 20 mol-% of at least one first comonomer (b1b) of formula (II)

wherein
R 1 to R 4 are each independently of one another selected from the group consisting of H, C 1 -C 4 -alkyl and halogen-substituted C 1 -C 4 -alkyl;
R 5 is selected from the group consisting of a chemical bond, a (—CR 5a R 5b —) group and a (—CR 5a R 5b O—) group
wherein
R 5a and R 5b are each independently of one another selected from the group consisting of H and unsubstituted or at least monosubstituted C 1 -C 4 -alkyl,
wherein the at least monosubstituted C 1 -C 4 -alkyl substituents are selected from the group consisting of F, Cl, Br, OH and C 1 -C 4 -alkyl;
n is 0, 1, 2 or 3;

and
from 0 to 20 mol-% of at least one second comonomer (b1c) selected from the group consisting of a compound of formula (III) and a compound of formula (IV)
wherein
Z is selected from the group consisting of a chemical bond, an (—O—) group and an (—O—R 6 —O—) group,
wherein
R 6 is selected from the group consisting of unsubstituted C 1 -C 8 -alkylene and C 3 -C 8 -cycloalkylene.

5. The process according to claim 1 , wherein the temperature (T M ) during the heating is from 140 to 240° C.

6. The process according to claim 1 , wherein the removing of the binder (B) is performed at a temperature below the melting point of the binder (B).

7. The process according to claim 1 , further comprising, after the removing of the binder (B), sintering the three-dimensional brown body to form a three-dimensional sintered body.

8. The process of claim 7 , wherein the three-dimensional sintered body comprises less than 0.5% by volume of the binder (B) based on the total volume of the three-dimensional sintered body.

9. The process according to claim 1 , wherein the mixture (M) is provided to a nozzle and is then heated to the temperature (T M ).

Assignees

• Basf Se

Inventors

• Nestle Nikolaus
• Hermant Marie-Claire
• Schmidt Kris

Classifications

• B28B11/243

  Setting, e.g. drying, dehydrating or firing ceramic articles (B28B11/242 takes precedence) · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B33Y70/10

  Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials · CPC title

• C04B35/62227

  obtaining fibres · CPC title

• C04B35/634

  Polymers (C04B35/636 takes precedence) · CPC title