Increasing the useful range of cationic photoinitiators in stereolithography

• US 5,494,618 A
• Filed: 06/27/1994
• Issued: 02/27/1996
• Est. Priority Date: 06/27/1994
• Status: Expired due to Term

• Current Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Original Assignee: Alliedsignal Inc.
• Inventors: Barnes, Darryl K., Sitzmann, Eugene V., Anderson, Russell F.
• Primary Examiner(s): Tentoni, Leo B.
• Application Number:
  US08/266,829
• Time in Patent Office: 610 Days
• Field of Search: 264/22, 264/236, 264/308, 156/242, 156/273.3, 156/273.5, 156/275.5, 156/307.1, 156/272.8, 427/508, 427/510, 427/512, 427/553, 427/554, 427/555
• US Class Current: 264/401
• CPC Class Codes: B33Y 70/00 Materials specially adapted for additive manufacturing
• CPC Class Codes: G03F 7/0037 Production of three-dimensional images
• CPC Class Codes: G03F 7/029 Inorganic compounds; Onium compounds; Organic compounds having hetero atoms other than oxygen, nitrogen or sulfur
• 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 7/091 characterised by antireflection means or light filtering or absorbing means, e.g. anti-halation, contrast enhancement

Abstract

Polymer precursor formulations suitable for stereolithography may be prepared from compositions containing vinyl ether functionalized compounds and epoxy functionalized compounds plus an effective amount of a cationic photoinitiator and an ultraviolet light-absorbing compound to provide a predetermined depth of cure. Preferably, the ultraviolet light-absorbing compound is anthracene or its derivatives.

Claims

1. In the process of stereolithography in which a three-dimensional object is built up in successive layers by polymerizing cationically polymerizable monomers by the catalytic action of cationic photoinitiators activated by a moving beam of ultraviolet light, the improvement comprising adding ultraviolet light-absorbing compounds to said monomers in quantities sufficient to provide a predetermined depth of cure.

2. The process of claim 1 wherein said monomers comprise vinyl ethers and epoxides.

3. The process of claim 2 wherein said cationic photoinitiators are onium salts.

4. The process of claim 3 wherein said ultraviolet light is provided by an Argon ion laser.

5. The process of claim 4 wherein said ultraviolet absorbing compounds are anthracene and/or derivatives thereof.

6. The process of claim 1 wherein said ultraviolet light-absorbing compounds are present in less than 0.2 pph by weight of said monomers.

7. The process of claim 5 wherein said ultraviolet light-absorbing compounds are at least one member of the group consisting of anthracene, 9-anthroic acid, 9,10-diphenylanthracene, 9,10-dimethoxy-2-ethyl anthracene, and 9-anthracene methanol.

8. The process of claim 7 wherein said ultraviolet light-absorbing compound thereof is 9-anthracene methanol.

9. The process of claim 5 wherein said ultraviolet light-absorbing compounds are selected from the group consisting of 9-phenyl anthracene, 2-methyl anthracene, 9-vinyl anthracene, bianthranyl and 9,10-dinaphthyl anthracene.

10. The process of claim 4 wherein said ultraviolet light-absorbing compounds are stilbene derivatives.