Ionizing radiation post-curing of objects produced by stereolithography and other methods

• US 6,107,008 A
• Filed: 08/29/1997
• Issued: 08/22/2000
• Est. Priority Date: 08/29/1997
• Status: Expired due to Fees

• Current Assignee: Lockheed Martin Energy Systems, Inc. (French Alternative Energies and Atomic Energy Commission), Lockheed Martin Energy Research Corporation (Martin Marietta Corporation), Lockheed Martin Integrated Systems Incorporated (Martin Marietta Corporation)
• Original Assignee: Lockheed Martin Energy Systems, Inc. (French Alternative Energies and Atomic Energy Commission), Lockheed Martin Energy Research Corporation (Martin Marietta Corporation)
• Inventors: Janke, Christopher J., Eberle, Claude C., Howell, David H.
• Primary Examiner(s): Hamilton, Cynthia
• Application Number:
  US08/921,417
• Time in Patent Office: 1,089 Days
• Field of Search: 430/328, 430/296, 430/942, 430/394, 430/966, 430/967, 430/269, 264/401, 264/486, 264/488, 264/482, 264/485, 522/2, 522/4
• US Class Current: 430/328
• CPC Class Codes: B29C 2035/0833 using actinic light
• CPC Class Codes: B29C 2035/0877 using electron radiation, e.g. beta-rays
• CPC Class Codes: B29C 2791/001 Shaping in several steps
• CPC Class Codes: B29C 35/08 by wave energy or particle radiation B29C64/00, B29C71/04 take precedence
• CPC Class Codes: B29C 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• CPC Class Codes: B29C 71/04 by wave energy or particle radiation , e.g. for curing or vulcanising preformed articles during moulding, e.g. in a mould B29C35/08
• CPC Class Codes: B29K 2105/243 Partially cured
• CPC Class Codes: B33Y 40/20 Post-treatment, e.g. curing, coating or polishing
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: B33Y 80/00 Products made by additive manufacturing
• CPC Class Codes: G03F 7/0037 Production of three-dimensional images
• CPC Class Codes: G03F 7/0045 with organic non-macromolecular light-sensitive compounds not otherwise provided for, e.g. dissolution inhibitors
• CPC Class Codes: G03F 7/038 Macromolecular compounds which are rendered insoluble or differentially wettable G03F7/075 takes precedence; macromolecular azides G03F7/012; macromolecular diazonium compounds G03F7/021
• CPC Class Codes: G03F 7/38 Treatment before imagewise removal, e.g. prebaking G03F7/265 takes precedence
• CPC Class Codes: Y10S 430/143 Electron beam
• CPC Class Codes: Y10S 430/167 X-ray
• CPC Class Codes: Y10S 430/168 X-ray exposure process

Abstract

An object comprised of a curable material and formed by stereolithography or another three-dimensional prototyping method, in which the object has undergone initial curing, is subjected to post-curing by ionizing radiation, such as an electron beam having a predetermined beam output energy, which is applied in a predetermined dosage and at a predetermined dose rate. The post-cured object exhibits a property profile which is superior to that which existed prior to the ionizing radiation post-curing.

Claims

1. A method for forming an object comprising:

forming a mixture of a cationically curable epoxy resin and a cationic initiator;

shaping said mixture by irradiating the mixture in a pattern using actinic radiation sufficient to obtain an uniform and incomplete cure; and

post-curing said shaped mixture without thermal cure by irradiation using high-energy electron beam ionizing radiation for a period of time sufficient to effectuate efficient cross-linking and an essentially complete and uniform curing, wherein said curable epoxy resin comprises a semi-solid triglycidyl ether of tris(hydroxyphenyl) methane and a low viscosity bisphenol A epoxy resin.