Filaments based on a coated core material

• US 10,501,869 B2
• Filed: 07/07/2016
• Issued: 12/10/2019
• Est. Priority Date: 07/14/2015
• Status: Active Grant

• Current Assignee: BASF SE
• Original Assignee: BASF SE
• Inventors: Van Der Schaaf, Paul, Inderbitzin, Bruno, Hermant, Marie-Claire, Schomer, Martina
• Primary Examiner(s): Boykin, Terressa
• Application Number:
  US15/744,428
• Publication Number:
  US 20180202076A1
• Time in Patent Office: 1,251 Days
• Field of Search: 428394
• CPC Class Codes: B29C 48/0021 combined with joining, lining or laminating
• CPC Class Codes: B29C 48/05 Filamentary, e.g. strands
• CPC Class Codes: B29C 64/118 using filamentary material being melted, e.g. fused deposition modelling [FDM]
• CPC Class Codes: B29C 64/209 Heads; Nozzles
• CPC Class Codes: B29D 99/0078 Producing filamentary materials
• CPC Class Codes: B33Y 70/10 Composites of different types of material, e.g. mixtures of ceramics and polymers or mixtures of metals and biomaterials
• CPC Class Codes: C04B 2235/5264 characterised by the diameter of the fibers
• CPC Class Codes: C04B 2235/5436 micrometer sized, i.e. from 1 to 100 micron
• CPC Class Codes: C04B 2235/5445 submicron sized, i.e. from 0,1 to 1 micron
• CPC Class Codes: C04B 2235/6021 Extrusion moulding
• CPC Class Codes: C04B 2235/6026 Computer aided shaping, e.g. rapid prototyping
• CPC Class Codes: C04B 35/01 based on oxide ceramics
• CPC Class Codes: C04B 35/053 Fine ceramics
• CPC Class Codes: C04B 35/057 based on calcium oxide
• CPC Class Codes: C04B 35/111 Fine ceramics
• CPC Class Codes: C04B 35/14 based on silica
• CPC Class Codes: C04B 35/486 Fine ceramics
• CPC Class Codes: C04B 35/505 based on yttrium oxide
• CPC Class Codes: C04B 35/565 based on silicon carbide
• CPC Class Codes: C04B 35/58071 based on titanium borides
• CPC Class Codes: C04B 35/581 : based on aluminium nitride
• CPC Class Codes: C04B 35/584 : based on silicon nitride
• CPC Class Codes: C04B 35/62231 : based on oxide ceramics
• CPC Class Codes: C04B 35/62236 : Fibres based on aluminium oxide
• CPC Class Codes: C04B 35/6224 : Fibres based on silica
• CPC Class Codes: C04B 35/6225 : Fibres based on zirconium oxide, e.g. zirconates such as PZT
• CPC Class Codes: C04B 35/62263 : Fibres based on magnesium oxide
• CPC Class Codes: C04B 35/62268 : Fibres based on metal phosphorus oxides, e.g. phosphates
• CPC Class Codes: C04B 35/62281 : based on silicon carbide C04B35/571 takes precedence
• CPC Class Codes: C04B 35/62286 : Fibres based on nitrides
• CPC Class Codes: C04B 35/62295 : based on silicon nitride C04B35/589 takes precedence
• CPC Class Codes: C04B 35/62844 : Coating fibres
• CPC Class Codes: C04B 35/634 : Polymers C04B35/636 takes precedence
• CPC Class Codes: C04B 35/63408 : Polyalkenes
• CPC Class Codes: C04B 35/63476 : Phenol-formaldehyde condensation polymers
• CPC Class Codes: C04B 35/638 : Removal thereof
• CPC Class Codes: D01F 1/10 : Other agents for modifying properties
• CPC Class Codes: D01F 6/66 : from polyethers
• CPC Class Codes: D01F 8/04 : from synthetic polymers
• CPC Class Codes: D01F 8/16 : with at least one other macromolecular compound obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds as constituent

Abstract

A filament containing a core material (CM) coated with a layer of shell material (SM), wherein the (CM) contains the components a) to c):

• a) 30 to 80% by volume, based on the total volume of the C) of at least one inorganic powder (IP),
• b) 20 to 70% by volume, based on the total volume of the CM of at least one binder (B) comprising component b1)
• b1) at least one polymer (P) and
• c) optionally at least one additive,
• wherein the at least one polymer (P) is a polyoxymethylene (POM) homopolymer, a POM copolymer or POM terpolymer and wherein at least some of the OH-end groups of the PO) homopolymer are capped,
• and the SM contains the components d) to f):
• d) 75 to 100% by volume, based on the total volume of the SM of at least one thermoplastic polymer,
• e) optionally at least one inorganic powder (IP), and
• f) optionally at least one additive, wherein the thickness of the layer of shell material is 0.05 to 0.5 mm.

Claims

1. A filament comprising a core material (CM) coated with a layer of shell material (SM), wherein

the core material (CM) comprises the components a) to c):

a) 30 to 80% by volume, based on the total volume of the core material (CM) of at least one inorganic powder (IP),

b) 20 to 70% by volume, based on the total volume of the core material (CM) of at least one binder (B) comprising component b1),

b1) at least one polymer (P) and

c) 0 to 20% by volume, based on the total volume of the core material (CM) of at least one additive (A),

wherein the at least one polymer (P) is a polyoxymethylene (POM) homopolymer, a polyoxymethylene (POM) copolymer or polyoxymethylene (POM) terpolymer and wherein at least some of the OH-end groups of the polyoxymethylene (POM) homopolymer are capped,

and the shell material (SM) comprises the components d) to f);

d) 75 to 100% by volume, based on the total volume of the shell material (SM) of at least one thermoplastic polymer (TP)

e) 0 to 20% by volume, based on the total volume of the shell material (SM) of the at least one inorganic powder (IP), and

f) 0 to 25% by volume, based on the total weight of the shell material (SM) of the at least one additive (A), wherein the thickness of the layer of shell material is 0.05 to 0.5 mm.

2. The filament according to claim 1, wherein the binder (B)

i) comprises from 50 to 96% by weight or the at least one polymer (P), based on the total weight of the binder.

3. The filament according to claim 1, wherein the binder (B) in the core material (CM) further comprises components b2) or b3)

b2) at least one polyolefin (PO),

b3) at least one further polymer (FP), in case component is a polyoxymethylene (POM).

4. The filament according to claim 3, wherein the binder (B) comprises 2 to 35% by weight of component b2), based on the total weight of the binder (B), or from 2 to 40% by weight of component b3), based on the total weight of the binder (B).

5. The filament according to claim 1, wherein

i) the diameter of the filament is 1.5 to 3.5 mm, or

ii) the diameter of the core material is 1.5 to 3.0 mm, or

iii) the thickness of the layer of shell material (SM) is 0.09 to 0.3 mm, or

iv) the particle size of the inorganic powder (IP) is from 0.1 to 80 or

v) 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, or

vi) the at least one thermoplastic polymer (TP) of the shell material (SM) is selected from the group of polyoxymethylene (POM), polyolefins (PE) such as polypropylene or polyethylene, polyurethanes (PU), polyamides (PA), polyethers (PETH), polycarbonates (PC), or polyesters (PES) such as polylactic acid and blends thereof.

6. The filament according to claim 1, wherein the polymer (P) in component (b1) is a polyoxymethylene (POM) copolymer which is prepared by polymerization of

from at least 50 mol-% of a formaldehyde source (b1a),

from 0.01 to 20 mol-% of at least one first comonomer (b1 b) of the general formula (II)

7. The filament according to claim 3, wherein the further polymer (FP) is at least one further polymer (FP) selected from the group consisting of a polyether, a polyurethane, a polyepoxide, a polyamide, a vinyl aromatic polymer, a poly(vinyl ester), a poly(vinyl ether), a poly(alkyl (meth)acrylate) and copolymers thereof.

8. A process for the preparation of a filament according to claim 1, wherein a core material (CM) is coated with a layer of a shell material (SM) by co-extrusion of the core material (CM) with the shell material (SM).

9. A process for preparation of a three-dimensional green body, by a fused filament fabrication process, comprising at least the steps a), b), c),

a) providing the filament according to claim 1 on a spool to a noozle,

b) heating the filament to a temperature (T_M),

c) depositing of the heated filament obtained in step b) in a build chamber using a layer based additive technique in order to form the three dimensional green-body.

10. The process according to claim 9, wherein the temperature (T_M) in step b) is 140 to 240°

C.

11. The process according to claim 9, wherein step c) is followed by a step d) in which at least a part of the binder (B) or at least a part of the shell material (SM) is removed from the three-dimensional green body in order to form a three-dimensional brown body.

12. The process according to claim 11, wherein in step d)

i) the binder (B) or the shell material (SM) is removed by acidic treatment or

ii) the binder (B) or the shell material (SM) is removed at a temperature below the melting point of the binder (B) or the shell material (SM).

13. The process according to claim 11, wherein step d) is followed by a step e), in which the three-dimensional brown body is sintered to form a three-dimensional sintered body.

14. A three-dimensional green-body, prepared by the process according to claim 9.

15. The filament according to claim 1, wherein

i) the diameter of the filament is 2.0 to 3.1 mm, or

ii) the diameter of the core material is 1.9 to 2.7 mm, or

iii) the thickness of the layer of shell material (SM) is 0.1 to 0.25 mm, or the particle size of the inorganic powder (IP) is from 0.5 to 50 μ

m.

16. The filament according to claim 2, wherein the binder (B) in the core material (CM) further comprises components b2) or b3)

b2) at least one polyolefin (PO),

b3) at least one further polymer (FP), in case component is a polyoxymethylene (POM).

17. The filament according to claim 16, wherein the binder (B) comprises 2 to 35% by weight of component b2), based on the total weight of the binder (B), or from 2 to 40% by weight of component b3), based on the total weight of the binder (B).

18. The filament according to claim 17, wherein

i) the diameter of the filament is 1.5 to 3.5 mm, or

ii) the diameter of the core material is 1.5 to 3.0 mm, or

iii) the thickness of the layer of shell material (SM) is 0.09 to 0.3 mm, or

iv) the particle size of the inorganic powder (IP) is from 0.1 to 80 μ

m, or

v) 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, or

vi) the at least one thermoplastic polymer (TP) of the shell material (SM) is selected from the group of polyoxymethylene (POM), polyolefins (PE) such as polypropylene or polyethylene, polyurethanes (PU), polyamides (PA), polyethers (PETH), polycarbonates (PC), or polyesters (PES) such as polylactic acid and blends thereof.

19. The filament according to claim 18, wherein the polymer (P) in component (b1) is a polyoxymethylene (POM) copolymer which is prepared by polymerization of

from at least 50 mol-% of a formaldehyde source (b1a),

from 0.01 to 20 mol-% of at least one first comonomer (b1b) of the general formula (II)

20. The filament according to claim 19, wherein the further polymer (FP) is at least one further polymer (FP) selected from the group consisting of a polyether, a polyurethane, a polyepoxide, a polyamide, a vinyl aromatic polymer, a poly(vinyl ester), a poly(vinyl ether), a poly(alkyl (meth)acrylate) and copolymers thereof.