Water-breakable formulations and additive manufacturing processes employing same

Patent metadata

Field	Value
Publication number	US-11780172-B2
Application number	US-202117242459-A
Country	US
Kind code	B2
Filing date	Apr 28, 2021
Priority date	Jan 15, 2016
Publication date	Oct 10, 2023
Grant date	Oct 10, 2023

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 monomer 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)—NR 1 and C(═O)—O;
R 1 is selected from hydrogen, alkyl and cycloalkyl;
Y is N + R 4 R 5 R 6 Q − ;
L is an alkylene of 1 to 4 carbon atoms;
Q − is a negatively charged counter ion; 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,

and at least one multi-functional curable material represented by Formula II:

wherein:
Rb is hydrogen, alkyl or cycloalkyl;
n is 2, representing a number of polymerizable groups ═C(Rb)—W—;
W in each of said polymerizable groups is C(═O)—O; and
B is a hydrocarbon moiety of 1 to 20 atoms, interrupted and/or substituted by at least one group selected from oxygen, hydroxy, hydroxyalkyl, amine, aminoalkyl, thiol and thioalkyl,
wherein a concentration of said mono-functional curable material ranges from 50 to 80 weight percents of the total weight of the formulation; and
a concentration of said multi-functional curable material ranges from 5 to 15 weight percents of the total weight of the formulation.

2. The curable formulation of claim 1 , further comprising an additional mono-functional curable material 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)—NR 1 and C(═O)—O;
R 1 is selected from hydrogen, alkyl and cycloalkyl;
L is an alkylene of 1 to 4 carbon atoms; and
Y is OR 3 , wherein R 3 is hydrogen.

3. The curable formulation of claim 2 , wherein a concentration of said additional mono-functional curable material ranges from 5 to 20 weight percents of the total weight of the formulation.

4. The curable formulation of claim 1 , wherein a concentration ratio of said at least one mono-functional curable material and said at least one multi-functional curable material is selected as forming, upon exposing the formulation to a curing energy, a cured material that breaks into particles upon immersion in an aqueous solution.

5. The curable formulation of claim 1 , wherein a concentration ratio of said at least one mono-functional curable material and said at least one multi-functional curable material is selected as forming, upon exposing the formulation to a curing energy, a cured material that features a degree of cross linking that ranges from 10 to 80%.

6. The curable formulation of claim 1 , wherein a concentration ratio of said at least one mono-functional curable material and said at least one multi-functional curable material is selected as forming, upon exposing the formulation to a curing energy, a cured material, wherein a 3-gram cube made of said cured material breaks into particles upon static immersion in water in less than 10 hours.

7. The curable formulation of claim 1 , wherein said multi-functional curable material forms a polymer featuring a Tg higher than 20° C.

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

9. The curable formulation of claim 8 , wherein said at least one non-curable material comprises a water-miscible polymer.

10. 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 a curable formulation that comprises at least one mono-functional curable monomer 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)—NR 1 and C(═O)—O;
R 1 is selected from hydrogen, alkyl and cycloalkyl;
Y is N + R 4 R 5 R 6 Q − ;
L is an alkylene of 1 to 4 carbon atoms;
Q − is a negatively charged counter ion; 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,

and at least one multi-functional curable material represented by Formula II:

wherein:
Rb is hydrogen, alkyl or cycloalkyl;
n is 2, representing a number of polymerizable groups ═C(Rb)—W—;
W in each of said polymerizable groups is C(═O)—O; and
B is a hydrocarbon moiety of 1 to 20 atoms, interrupted and/or substituted by at least one group selected from oxygen, hydroxy, hydroxyalkyl, amine, aminoalkyl, thiol and thioalkyl,
wherein a concentration of said mono-functional curable material ranges from 50 to 80 weight percents of the total weight of the formulation; and
a concentration of said multi-functional curable material ranges from 5 to 15 weight percents of the total weight of the formulation.

11. The method of claim 10 , wherein the curable formulation further comprises an additional mono-functional curable material 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)—NR 1 and C(═O)—O;
R 1 is selected from hydrogen, alkyl and cycloalkyl;
L is an alkylene of 1 to 4 carbon atoms; and
Y is OR 3 , wherein R 3 is hydrogen.

12. The method of claim 11 , wherein a concentration of said additional mono-functional curable material ranges from 5 to 20 weight percents of the total weight of the formulation.

13. The method of claim 10 , wherein a concentration ratio of said at least one mono-functional curable material and said at least one multi-functional curable material is selected as forming, upon exposing the formulation to a curing energy, a cured material that breaks into particles upon immersion in an aqueous solution.

14. The method of claim 10 , wherein a concentration ratio of said at least one mono-functional curable material and said at least one multi-functional curable material is selected as forming, upon exposing the formulation to a curing energy, a cured material that features a degree of cross linking that ranges from 10 to 80%.

15. The method of claim 10 , wherein said building material comprises a modeling material formulation and a support material formulation, and wherein said support material formulation comprises the curable formulation which comprises said at least one mono-functional curable material and said at least one multi-functional curable material.

16. The method of claim 15 , 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

Assignees

• Stratasys Ltd

Inventors

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

Classifications

• B29C64/40 Primary

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

• B29C64/112

  using individual droplets, e.g. from jetting heads · CPC title

• B33Y40/10

  Pre-treatment · CPC title

• B33Y40/20

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

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title