Solid imaging method using photohardenable compositions containing hollow spheres

• US 5,051,334 A
• Filed: 04/21/1989
• Issued: 09/24/1991
• Est. Priority Date: 04/21/1989
• Status: Expired due to Term

• Current Assignee: DSM IP Assets BV (DSM-Firmenich AG)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Fan, Roxy N.
• Primary Examiner(s): BRAMMER, JACK
• Application Number:
  US07/341,511
• Time in Patent Office: 886 Days
• Field of Search: 430/269, 430/945, 430/270, 522/2, 525/174.4, 525/174, 525/162, 264/22
• US Class Current: 430/269
• CPC Class Codes: B29C 2035/0833 using actinic light
• CPC Class Codes: B29C 2035/0838 using laser
• CPC Class Codes: B29C 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• CPC Class Codes: B29C 70/64 the filler influencing the surface characteristics of the material, e.g. by concentrating near the surface or by incorporating in the surface by force
• CPC Class Codes: C08K 7/22 Expanded, porous or hollow particles
• CPC Class Codes: C08L 33/06 of esters containing only carbon, hydrogen and oxygen, which oxygen atoms are present only as part of the carboxyl radical
• CPC Class Codes: G03F 7/0037 Production of three-dimensional images
• CPC Class Codes: G03F 7/004 Photosensitive materials G03F7/12, G03F7/14 take precedence
• 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: Y10S 430/146 Laser beam
• CPC Class Codes: Y10S 430/148 Light sensitive titanium compound containing

Abstract

An integral three dimensional object is formed from a photohardenable liquid composition containing radiation deflecting matter which is a thermal insulator and having a different index of refraction from the liquid.

Claims

1. A method for accurately fabricating an integral three dimensional object from successive layers of a photohardenable liquid composition comprising the steps of:

(a) forming a layer of a photohardenable liquid;

(b) photohardening at least a portion of the layer of photohardenable liquid by exposure to actinic radiation;

(c) introducing a new layer of photohardenable liquid onto the layer previously exposed to actinic radiation; and

(d) photohardening at least a portion of the new liquid layer by exposure to actinic radiation, with the requirement that the photohardenable composition comprises an ethylenically unsaturated monomer, photoinitiator, and radiation deflecting matter comprising hollow spheres, the deflecting matter having a first index of refraction, the rest of the composition having a second index of refraction, the absolute value of the difference between the first index of refraction and the second index of refraction being different than zero; and

(e) successively repeating steps (c) and (d) until the three dimensional object is complete.

2. The method of claim 1, wherein the absolute value of the difference between the first index of refraction and the second index of refraction is greater than 0.02.

3. The method of claim 2, wherein the actinic radiation is in the form of a beam.

4. The method of claim 3, wherein the beam is a laser beam.

5. The method of claim 1, wherein the hollow spheres are glass spheres containing a gas.

6. The method of claim 1, wherein the hollow spheres are ceramic spheres containing a gas.

7. The method of claim 1, wherein the specific gravity of the radiation deflecting matter is within ±

10% of the specific gravity of the rest of the composition.

8. A rigid solid object made with the method of claim 1.