Powder comprising polymer-coated glass particles

Patent metadata

Field	Value
Publication number	US-10787559-B2
Application number	US-201213541181-A
Country	US
Kind code	B2
Filing date	Jul 3, 2012
Priority date	Jul 6, 2011
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

Composite particles comprising core particles completely or partially coated with a precipitated polymer, where the d50 median diameter of the core particles is from 3 to 100 μm and wherein the glass core particle material is at least one selected from the group consisting of a solid glass bead, a hollow glass bead, a porous glass bead, and a foamed glass particle. A method to prepare the particles includes dissolution of a polymer in a solvent and precipitation of the polymer in the presence of a suspension of the core glass particles. Further provided is a layer by layer moulding process employing the composite particles and mouldings obtained therefrom.

First claim

The invention claimed is:

1. A powder, comprising composite particles:
wherein the composite particles, comprise:
a core glass particle having a d 50 median diameter of 3 to 100 μm; and
at least a partial coating of a polymer on the core;

wherein a ratio of the d 50 median diameter of the composite particles to the d 50 median diameter of the core glass particles is from 1.01 to 5.0, and
wherein a number average weight ratio of the polymer coating to the core glass particle, is from 1 to 30.

2. The powder according to claim 1 , wherein
the core glass particle is at least one selected from the group consisting of a solid glass bead, a hollow glass bead, a porous glass bead, and a foamed glass particle, and
the core glass particle is optionally sized in the composite particle.

3. The powder according to claim 2 , wherein the d 50 median diameter of the core glass particles is from 3 to 80 μm.

4. The powder according to claim 1 , wherein the polymer of the coating comprises at least one polymer selected from the group consisting of a polyolefin, a polyethylene, a polypropylene, a polyvinyl chloride, a polyacetal, a polystyrene, a polyimide, a polysulphone, a poly(N-methylmethacrylimide) (PMMI), a polymethyl methacrylate (PMMA), a polyvinylidene fluoride (PVDF), an ionomer, a polyether ketone, a polyaryl ether ketone, a polyamide, and a copolyamide.

5. The powder according to claim 1 , wherein a d 50 median diameter of the composite particles is from 20 to 150 μm.

6. The powder according to claim 1 , wherein a ratio of the d 50 median diameter of the composite particles to the d 50 median diameter of the core glass particles is from 1.05 to 5.0.

7. The powder according to claim 1 , wherein an aspect ratio of the core glass particle is 20 or less.

8. The powder according to claim 1 , wherein a density of the core glass particles is from 0.1 to 6.6 g/cm 3 .

9. The powder according to claim 1 , wherein the coating polymer is a polyamicle having at least 8 carbons per carbonamide group.

10. The powder according to claim 9 , wherein the polyamide is at least one selected from the group consisting of nylon-6,12, nylon-11 and nylon-12.

11. The powder according to claim 1 , which further comprises at least one selected from the group consisting of a powder-flow aid, an organic pigment, an inorganic pigment, and a sterically hindered phenol.

12. The powder according to claim 11 , wherein a content of the composite particles in the powder is at least 50% by weight.

13. The powder according to claim 1 , wherein the number average weight ratio of the polymer coating to the core glass particle, is from 1.4 to 10.

14. A process for producing the composite particles according to claim 1 , the process comprising:
at least partially dissolving a polymer for the coating in a medium comprising a solvent which at least partially dissolves the polymer;
adding the core glass particles to the medium, before, during or after at least partially dissolving the polymer;
suspending the core glass particles in the medium; and then
precipitating the polymer from the at least partial solution onto the core glass particles to obtain the composite particles;
wherein a ratio of the d 50 median diameter of the composite particles to the d 50 median diameter of the core glass particles is from 1.01 to 5.0.

15. The process according to claim 14 , wherein a density of the core particles is greater or not more than 20% smaller than the density of the solvent used for the precipitation of the polymer.

16. The process according to claim 14 , wherein the solvent for the polymer is ethanol and a density of the core particles is greater or not more than 20% smaller than the density of ethanol.

17. A process for producing a moulded article, the process comprising:
applying a layer of the composite powder according to claim 1 ;
selectively melting at least one region of the layer by introduction of electromagnetic energy;
allowing the melted region to solidify;
applying another layer of composite powder and repeating the melting and solidification to perform a layer-by-layer process in which a molding having a structure according to the selective treatment is obtained;
wherein the melting selectivity is achieved by applying susceptors, inhibitors, or absorbers to each applied layer or by applying a mask to the applied layer.

18. A moulded article obtained according to the process of claim 17 .

Assignees

• Monsheimer Sylvia
• Diekmann Wolfgang
• Baumann Franz Erich
• Hessel Geldmann Sigrid
• Warnke Kristiane
• Stemmer Heike
• Altkemper Stefan
• Evonik Operations Gmbh

Inventors

• Monsheimer Sylvia
• Diekmann Wolfgang
• Baumann Franz-Erich
• Hessel-Geldmann Sigrid
• Warnke Kristiane
• Stemmer Heike
• Altkemper Stefan

Classifications

• B33Y70/10

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

• C08K9/08 Primary

  Ingredients agglomerated by treatment with a binding agent · CPC title

• C09C1/28

  Compounds of silicon {(C09C1/0009, C09C1/0015, C09C1/0078 take precedence)} · CPC title

• B29C67/04

  Sintering (combined with compression B29C43/00) · CPC title

• C09C3/10

  Treatment with macromolecular organic compounds {(C09C3/006 takes precedence)} · CPC title