Water-breakable formulations and additive manufacturing processes employing same

Patent metadata

Field	Value
Publication number	US-11028205-B2
Application number	US-201716070280-A
Country	US
Kind code	B2
Filing date	Jan 15, 2017
Priority date	Jan 15, 2016
Publication date	Jun 8, 2021
Grant date	Jun 8, 2021

Abstract

Curable formulations which form cured materials that are breakable upon immersion in water are disclosed. The cured materials break into a plurality of particles being a few millimeters or less in size. Methods of fabricating three-dimensional objects utilizing the curable formulations are also disclosed, as well as model objects fabricated thereby. The curable formulations include at least a mono-functional curable material and a multi-functional curable material, as described in the specification.

First claim

What is claimed is:

1. A curable formulation comprising at least one mono-functional curable material and at least one multi-functional curable material, said mono-functional and multi-functional curable materials and a concentration ratio thereof being selected such that a cured material formed upon exposing the formulation to a curing energy breaks into particles upon immersion in an aqueous solution,
wherein:
said cured material breaks upon said immersion into particles having a size ranging from 1 micron to 100 mm; and/or
said cured material features a degree of cross linking that ranges from 10 to 80%; and/or
said cured material has a swelling capacity of from 10 to 300% by weight; and/or
a 3-gram cube made of said cured material breaks upon static immersion in water in less than 10 hours.

2. The curable formulation of claim 1 , wherein said at least one mono-functional curable material is represented by Formula I:

wherein:
Ra is hydrogen, alkyl or cycloalkyl; and
Z is represented by X-L-Y,
wherein:
X is selected from C(═O), C(═O)—NR 1 , C(═O)—O, P(═O)—(OR 2 )—O or is absent;
Y is selected from O − M + , OR 3 , NR 4 R 5 or N + R 4 R 5 R 6 Q;
L is a hydrocarbon moiety of 1 to 40 atoms in length, optionally interrupted by one or more heteroatom(s), said heteroatoms being independently selected from O, S and NR 2 , or is absent;

Q is a negatively charged counter ion;
M + is a positively charged counter ion;
R 1 and R 2 are each independently selected from hydrogen, alkyl and cycloalkyl;
R 3 is selected from hydrogen, alkyl, cycloalkyl and aryl; and
R 4 , R 5 and R 6 are each independently selected from hydrogen, alkyl and cycloalkyl, or, alternatively, R 4 and R 5 form a cyclic ring.

3. The curable formulation of claim 2 , wherein Y is N + R 4 R 5 R 6 Q.

4. The curable formulation of claim 3 , wherein L is a hydrocarbon moiety of 1 to 4 carbon atoms in length.

5. The curable formulation of claim 2 , wherein Y is NR 4 R 5 .

6. The curable formulation of claim 2 , wherein Y is OR 3 .

7. The curable formulation of claim 6 , wherein L is a hydrocarbon moiety interrupted by one or more heteroatom(s).

8. The curable formulation of claim 1 , wherein said mono-functional curable material forms a polymeric (cured) material featuring:
a water uptake of at least 200%; and/or
a hydrophilic lipophilic balance, determined according to Davies method, of at least 10; and/or
a water solubility of at least 50 weight percents.

9. The curable formulation of claim 1 , wherein said at least one multi-functional curable material:
(i) forms a polymer featuring a Tg higher than 20° C.; and/or
(iii) is represented by Formula II:

wherein:
Rb is hydrogen, alkyl or cycloalkyl;
n is an integer of from 2 to 10, representing a number of polymerizable groups ═C(Rb)—W—;
W in each of said polymerizable groups is independently selected from C(═O)—O, C(═O)—NR 8 , and C(═O) or is absent; and
B is a hydrocarbon moiety of 1 to 20 atoms, interrupted and/or substituted by at least one hydrogen donor-containing group.

10. The curable formulation of claim 9 , wherein said multi-functional curable material forms a polymer featuring said Tg higher than 20° C..

11. The curable formulation of claim 10 , wherein said multi-functional curable material is represented by Formula II.

12. The curable formulation of claim 11 , wherein said hydrogen donor-containing group is selected from oxygen, hydroxy, hydroxyalkyl, amine, aminoalkyl, thiol, and thioalkyl.

13. The curable formulation of claim 1 , wherein a concentration of said at least one mono-functional curable material ranges from 40 to 90, weight percents of the total weight of the formulation.

14. The curable formulation of claim 1 , wherein a concentration of said multi-functional curable material ranges from 5 to 60 weight percents of the total weight of the formulation.

15. The curable formulation of claim 1 , further comprising at least one non-curable material.

16. The curable formulation of claim 15 , wherein said at least one non-curable material comprises a water-miscible polymer.

17. The curable formulation of claim 1 , wherein at least 50% of said particles have a size lower than 10 mm.

18. A method of fabricating a three-dimensional model object, the method comprising dispensing a building material so as to sequentially form a plurality of layers in a configured pattern corresponding to the shape of the object, wherein said building material comprises the curable formulation of claim 1 .

19. The method of claim 18 , wherein said building material comprises a modeling material formulation and a support material formulation, said support material formulation comprising said curable formulation.

20. The method of claim 19 , further comprising, subsequent to said dispensing, exposing the building material to curing energy, to thereby obtain a printed objected which comprises a cured support material formed of said curable formulation; and
removing said cured support material, to thereby obtain the three-dimensional model object,
said removing comprises contacting said cured support material with water.

21. The method of claim 20 , wherein said contacting comprises static immersion of said cured support material in said water.

22. A three-dimensional object fabricated by the method of claim 18 .

Assignees

• Stratasys Ltd

Inventors

• Ely Tal
• Pokrass Mariana
• Peri Dani
• Levy Avraham
• Tenne Dana

Classifications

• G03F7/0037 Primary

  Production of three-dimensional images · CPC title

• B33Y40/10

  Pre-treatment · CPC title

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• B33Y40/20

  Post-treatment, e.g. curing, coating or polishing · CPC title

• B29C64/40 Primary

  Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof · CPC title