Three dimensional sintered inorganic structures using photopolymerization

• US 5,496,682 A
• Filed: 10/15/1993
• Issued: 03/05/1996
• Est. Priority Date: 10/15/1993
• Status: Expired due to Term

• Current Assignee: W R Grace & Company - CONN (Standard Industries Holdings, Inc.)
• Original Assignee: W R Grace & Company - CONN (Standard Industries Holdings, Inc.)
• Inventors: Quadir, Tariq, Hallock, John S., Mirle, Srinivas K.
• Primary Examiner(s): CHAPMAN, MARK A
• Application Number:
  US08/138,511
• Time in Patent Office: 872 Days
• Field of Search: 430/269, 430/281, 522/71, 522/83
• US Class Current: 430/269
• CPC Class Codes: B22F 10/12 by photopolymerisation, e.g. stereolithography [SLA] or digital light processing [DLP]
• CPC Class Codes: B22F 12/40 Radiation means
• 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: G03F 7/0037 Production of three-dimensional images
• CPC Class Codes: G03F 7/0047 characterised by additives for obtaining a metallic or ceramic pattern, e.g. by firing
• CPC Class Codes: G03F 7/027 Non-macromolecular photopolymerisable compounds having carbon-to-carbon double bonds, e.g. ethylenic compounds G03F7/075 takes precedence
• CPC Class Codes: Y02P 10/25 Process efficiency

Abstract

Dense sintered parts of ceramic and/or metallic materials are formed using stereo photolithography. An initial flowable mixture of sinterable inorganic particles, photocurable monomer, photoinitiator and dispersant is flowed over a substrate and cured in a selective pattern. Subsequent layers of the mixture are flowed over the substrate and cured to build a three dimensional body. The body is then fired to produce a dense sintered part. Parts having in excess of 95% of theoretical density can be produced.

Claims

1. A photocurable composition suitable for the formation of three dimensional sintered bodies by stereo photolithography, said composition comprising:

40-70 vol. % sinterable ceramic and/or metallic particles,

10-35 wt. % photocurable monomer based on the weight of the sinterable particles,

1-10 wt. % photocurable monomer based on the weight of the monomer,

1-10 wt. % dispersant based on the weight of the sintered particles, and a coupling agent.

2. The composition of claim 1 wherein said composition further contains a plasticizer.

3. The composition of claim 2 wherein said plasticizer is present at about 20-40 wt. % based on the weight of said monomer.

4. The composition of claim 2 wherein said plasticizer is selected from the group consisting of tripropylene glycol and glycerol trioleate.

5. The composition of claim 1 wherein said monomer comprises one or more acrylates.

6. The composition of claim 5 wherein said monomer includes a monomer selected from the group consisting of 2(2-ethoxyethoxy) ethylacrylate, trimethylolpropane triacrylate, ethoxylated trimethylolpropane triacrylate, and mixtures thereof.

7. The composition of claim 1 wherein said photoinitiator is selected from the group consisting of trimethyl benzophenone, alpha hydroxyketone, isopropylthioxanthone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinopropanone-1 and mixtures thereof.

8. The composition of claim 1 wherein said dispersant is a fatty propylenediamine dioleate.

9. The composition of claim 1 wherein said coupling agent is present at about 0.5-2.0 wt. % based on the weight of said sinterable particles.

10. The composition of claim 1 wherein said coupling agent is a silane selected from the group consisting of gamma-methacryloxypropyltrimethoxysilane and 3-acryloxypropyl-trimethoxysilane and mixtures thereof.

11. The composition of claim 1 wherein said composition contains about 50-60 vol. % of said sinterable powder.

12. The composition of claim 1 wherein said sinterable particles are ceramic particles selected from the group consisting of alumina, tetragonal zirconia, silicon nitride and mixtures thereof.