Solid imaging method using photohardenable materials of self limiting thickness

• US 4,942,066 A
• Filed: 04/21/1989
• Issued: 07/17/1990
• Est. Priority Date: 04/21/1989
• Status: Expired due to Term

• Current Assignee: DSM Desotech Incorporated (DSM-Firmenich AG)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Grossa, Mario, Fan, Roxy N.
• Primary Examiner(s): SILVERMAN, STANLEY S
• Application Number:
  US07/341,612
• Time in Patent Office: 452 Days
• Field of Search: 427/54.1, 427/53.1, 427/407.1, 264/22, 264/25
• US Class Current: 427/553
• CPC Class Codes: B29C 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• CPC Class Codes: G03F 7/0037 Production of three-dimensional images
• 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 whereby a difference in an index of refraction increases by more than 0.01 after photohardening.

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, a photoinitiator, and radiation deflecting matter, wherein the deflection matter comprises dispersed particulate solid matter, emulsified liquid or gas, wherein substantially all deflecting matter is smaller than the depth of photohardening and wherein the deflecting matter has a first index of refraction, and the rest of the composition has a second index of refraction, and wherein the difference between the first index of refraction and the second index of refraction increases by more than 0.01 upon subjecting the composition to the radiation in order to selectively photoharden it.

2. The mehtod of claim 1 wherein steps (c) and (d) are successively repeated.

3. The method of claim 2, wherein the first index of refraction is smaller than the second index of refraction.

4. The process of claim 2, wherein the deflecting matter is an emulsified liquid.

5. The process of claim 2, wherein the deflecting matter is a dispersed solid.

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

7. The method of claim 6, wherein the radiation is in the region of light wavelength.