RADIATION CURABLE RESIN COMPOSITION FOR MAKING COLORED THREE DIMENSIONAL OBJECTS

• US 20080118666A1
• Filed: 11/19/2007
• Published: 05/22/2008
• Est. Priority Date: 11/27/2001
• Status: Abandoned Application

• Current Assignee: Glen A. Thommes, John A. Lawton, Xiaorong You
• Original Assignee: Glen A. Thommes, John A. Lawton, Xiaorong You
• Inventors: Thommes, Glen A., You, Xiaorong, Lawton, John A.
• Application Number:
  US11/942,566
• Publication Number:
  US 20080118666A1
• Time in Patent Office: Days
• US Class Current: 427/595
• CPC Class Codes: C08G 2650/16 Photopolymerisation
• CPC Class Codes: C08G 59/18 Macromolecules obtained by polymerising compounds containing more than one epoxy group per molecule using curing agents or catalysts which react with the epoxy groups ; e.g. general methods of curing
• CPC Class Codes: C08G 59/68 characterised by the catalysts used
• CPC Class Codes: C08G 65/10 characterised by the catalysts used
• CPC Class Codes: C08G 65/105 Onium compounds
• CPC Class Codes: G03F 7/0037 Production of three-dimensional images
• 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: 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 7/105 having substances, e.g. indicators, for forming visible images

Abstract

A radiation curable resin composition suitable for making three dimensional objects comprises at least one epoxy compound, and a cationic photoinitiator, wherein the resin composition has a first color or no color before cure and wherein a three dimensional object made from the resin by subjecting the resin to radiation shows a second color which is different from the color of the resin composition before cure.

Claims

1. A radiation curable resin composition suitable for making three dimensional objects comprising

A) at least one epoxy compound

B) a cationic photoinitiator,

wherein the resin composition has a first color or no color before cure and

wherein a three dimensional object made from the resin by subjecting the resin to radiation shows a second color which is different from the color of the resin composition before cure.

4. The resin composition according to claim 1, wherein a three dimensional object made from the resin composition by subjecting the resin to radiation shows color and has

i. a maximum absorbance of visible light of at least 1.0 measured in the range from 400 to 650 nm on a sample having a thickness of 250 mil (0.635 cm);

or

ii a L-value between 0 and 85.

5. The resin composition according to claim 4, wherein the maximum absorbance is more than 1.5, or wherein the L-value is between 20 and 75.

6. The resin composition according to claim 1, wherein the difference between the ‘

a’ and

/or ‘

b’

values of the object and the resin are larger than 20 units, wherein ‘

a’ and

‘

b’

relate to the L*a*b color space.

20. A process for forming a three-dimensional article comprising:

(1) coating a layer of a composition as in claim 1 onto a surface;

(2) exposing the layer imagewise to actinic radiation to form an imaged cross-section, wherein the radiation is of sufficient intensity to cause substantial curing of the layer in the exposed areas;

(3) coating a layer of the composition onto the previously exposed imaged cross-section;

(4) exposing said thin layer from step (3) imagewise to actinic radiation to form an additional imaged cross-section, wherein the radiation is of sufficient intensity to cause substantial curing and coloring of the thin layer in the exposed areas and to cause adhesion to the previously exposed imaged cross-section;

(5) repeating steps (3) and (4) a sufficient number of times in order to build up the three-dimensional article.

21. The process according to claim 20, wherein the colored part is separated from the resin by cleaning.

22. The process according to claim 20 wherein the exposure energy used in step (4) is in the range of 10-2 50 mJ/cm².

2. A radiation curable resin composition suitable for making three dimensional objects comprising

A) at least one epoxy compound

B) a cationic photoinitiator and

C) a latent coloring component,

wherein the resin composition shows

i. an absorbance of visible light in the region between 400 and 650 nm of less than 0.3 measured on a sample having a thickness of 1 cm;

or

ii a L-value between 90 and 100 in the CIELAB L*a*b color space, measured on a 0.5 mm sample against a white Leneta card background.

3. The resin composition according to claim 2, wherein the absorbance of visible light of the resin is less than 0.2.

7. A radiation curable composition suitable for making three dimensional objects comprising a radiation curable component, a photoinitiator and a filler, wherein the resin composition has a first color or no color before cure and wherein a three dimensional object made from the resin by subjecting the resin to radiation shows a second color which is different from the color of the resin.

8. The resin composition according to claim 7, wherein the resin composition has a L-value between 90 and 100, and wherein the object has a L value between 0 and 85.

9. The resin composition according to claim 7, wherein the resin composition contains a latent coloring component C).

10. The resin composition according to claim 9, wherein the component C is an isobenzofuranone based colour former.

11. The resin composition according to claim 7, wherein the amount of component C is between 0.0001 and 1 wt %.

12. The resin composition according to claim 7, wherein a component A is present that contains a cycloaliphatic diepoxide.

13. The resin composition according to claim 7, wherein a component D) is present which contains an ethylenically unsaturation

14. The resin composition according to claim 13, wherein component D) comprises a (meth)acrylate functionality.

15. The resin composition according to claim 14, wherein component D comprises a mono or diacrylate of bisphenol A diepoxide.

16. The resin composition according to claim 7, wherein the resin composition contains a radical photoinitiator E).

17. The resin composition according to claim 7, wherein the resin composition contains at least two epoxy compounds.

18. The resin composition according to claim 7, wherein the resin composition contains a polyol F).

19. A resin composition suitable for making three dimensional objects comprising

A) 30-80 wt % of at least one epoxy compound

B) a cationic photoinitiator,

C) a latent coloring component

D) a (meth)acrylate component

E) a radical photoinitiator

F) a polyol

wherein the resin composition has a first color or no color before cure and

wherein a three dimensional object made from the resin by subjecting the resin to radiation shows a second color which is different from the color of the resin composition before cure.