Photosensitive resin composition for rapid prototyping and a process for the manufacture of 3-dimensional objects

• US 6,251,557 B1
• Filed: 09/07/1999
• Issued: 06/26/2001
• Est. Priority Date: 05/09/1996
• Status: Expired due to Term

• Current Assignee: DSM IP Assets BV (DSM-Firmenich AG)
• Original Assignee: DSM B.V.
• Inventors: Sullivan, Michael G., Lapin, Stephen C.
• Primary Examiner(s): Hamilton, Cynthia
• Application Number:
  US09/390,678
• Time in Patent Office: 658 Days
• Field of Search: 430/280.1, 430/269, 522/170, 522/168, 522/175, 522/181, 264/401
• US Class Current: 430/269
• CPC Class Codes: B29C 41/003 characterised by the choice of material
• CPC Class Codes: B29C 64/106 using only liquids or viscous materials, e.g. depositing a continuous bead of viscous material
• CPC Class Codes: B29C 64/188 involving additional operations performed on the added layers, e.g. smoothing, grinding or thickness control surface shaping B29C59/00; after-treatment of articles without altering their shape B29C71/00
• CPC Class Codes: B29K 2063/00 Use of EP, i.e. epoxy resins or derivatives thereof, as moulding material
• CPC Class Codes: G03F 7/0037 Production of three-dimensional images
• 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: Y10S 430/146 Laser beam

Abstract

The invention relates to a photosensitive resin composition for rapid prototyping comprising:

a. about 30 wt. % to about 70 wt. % of at least two epoxy resins, at least one of these resins is solid at room temperature and comprises aromatic groups, and at least one of these resins is liquid, having a viscosity at 25° C. lower than about 1,000 Pa.s,

b. about 15 wt. % to about 50 wt. % of at least one multifunctional acrylate compound

c. about 5 wt. % to about 30 wt. % of a hydroxyfunctional compound

d. about 1 wt. % to about 6 wt. % cationic photoinitiator

e. about 1 wt. % to about 6 wt. % free radical photoinitiator.

The invention further relates to a process for the manufacturing of 3-dimensional objects, known as rapid prototyping, wherein the photosensitive resin composition is used.

Claims

1. A process for manufacturing a 3-dimensional object comprising:

applying radiation to an uncured first layer of photosensitive resin composition in order to cure a predetermined area of said first layer,

thereafter introducing an uncured second layer of said photosensitive resin composition on top of said first layer and applying radiation to cure a predetermined area of said uncured second layer,

wherein said photosensitive resin composition comprises

(i) at least one acrylate compound;

(ii) at least one epoxy compound which is solid at room temperature;

(iii) at least one epoxy compound which is liquid at room temperature;

(iv) at least one cationic photoinitiator; and

(v) at least one free radical photoinitiator;

wherein the weight ratio of epoxy compounds to acrylate compounds in said composition is from 0.79 to 1.51.

2. The process of claim 1, wherein said composition comprises from about 30 wt. % to about 70 wt. % of epoxy compounds.

3. The process of claim 1, wherein said composition comprises from about 15 wt. % to about 50 wt. % of at least one multifunctional acrylate compound.

4. The process of claim 3, wherein said at least one multifunctional acrylate compound comprises from 2 to 5 acrylate groups.

5. The process of claim 1, wherein said composition comprises, relative to the total weight of the composition from about 5 wt. % to about 30 wt. % of at least one hydroxyftnctional compound.

6. The process of claim 5, wherein said hydroxyfunctional compound comprises from 2 to 5 hydroxy groups.

7. The process of claim 5, wherein said hydroxyfunctional compound comprises at least one ethylenically unsaturated group.

8. The process of claim 7, wherein said ethylenic unsaturation is methacrylate or acrylate.

9. The process of claim 1, wherein said composition comprises, relative to the total weight of the composition, from about 1 wt. % to about 6 wt. % of said at least one cationic photoinitiator.

10. The process of claim 1, wherein said composition comprises, relative to the total weight of the composition, from about 1 wt. % to about 6 wt. % of said at least one free radical photoinitiator.

11. The process of claim 1, wherein said composition comprises, relative to the total weight of the composition from about 15 wt. % to about 35 wt. % of said at least one solid epoxy compound, and from about 10 wt. % to about 40 wt % of said at least one liquid epoxy compound.

12. The process of claim 1, wherein said at least one liquid epoxy compound comprises a cycloaliphatic group.

13. The process of claim 1, wherein said at least one liquid epoxy compound comprises an aromatic group.

14. The process of claim 1, wherein said cationic photoinitiator is a triarylsulfonium salt.

15. The process of claim 1, wherein the predetermined area of said first layer and the predetermined area of said second layer are cured with a laser beam, said laser beam being motion controlled with a computer so as to have said laser beam scanned over said predetermined areas in order to initiate said curing.