Support material formulation and additive manufacturing processes employing same

Patent metadata

Field	Value
Publication number	US-11207839-B2
Application number	US-201615752621-A
Country	US
Kind code	B2
Filing date	Aug 14, 2016
Priority date	Aug 14, 2015
Publication date	Dec 28, 2021
Grant date	Dec 28, 2021

Abstract

Novel support material formulations, characterized as providing a cured support material with improved dissolution rate, while maintaining sufficient mechanical strength, are disclosed. The formulations comprise a water-miscible non-curable polymer, a first water-miscible, curable material and a second, water-miscible material that is selected capable of interfering with intermolecular interactions between polymeric chains formed upon exposing the first water-miscible material to curing energy. Methods of fabricating a three-dimensional object, and a three-dimensional object fabricated thereby are also disclosed.

First claim

What is claimed is:

1. A support material formulation comprising:
a non-curable water-miscible polymer which comprises a polyol;
a first water-miscible, curable material which comprises a mixture of a mono-functional poly(alkylene glycol) acrylate and a multi-functional poly(alkylene glycol) diacrylate; and
at least one second water-miscible curable material represented by Formula I:

wherein:
Ra is selected from H, C(1-4) alkyl and a hydrophilic group;
k is an integer ranging from 2 to 10; and
X and Y are each independently a hydrogen bond-forming moiety that comprises at least one nitrogen and/or oxygen atom,
wherein:
a concentration of said first curable material is lower than 30 weight percent of the total weight of the formulation;
a weight ratio between said mono-functional poly(alkylene glycol) acrylate and said multi-functional poly(alkylene glycol) acrylate in said first curable material ranges from 70:30 to 95:5;
a concentration of said mono-functional poly(alkylene glycol) acrylate ranges from 5 to 30 weight percent of the total weight of the formulation;
a concentration of said multi-functional poly(alkylene glycol) acrylate ranges from 0.5 to 5 weight percent of the total weight of the formulation; and
a concentration of said second curable material ranges from 5 to 15 weight percent of the total weight of the formulation.

2. The formulation of claim 1 , wherein Y is selected from hydroxyl, alkoxy, aryloxy, amine, alkylamine, dialkylamine, carboxylate, hydrazine, carbamate, hydrazine, a nitrogen-containing heteralicyclic, and an oxygen-containing heteralicyclic.

3. The formulation of claim 1 , wherein X is —O—.

4. The formulation of claim 1 , wherein X is —NRc-, wherein Rc is hydrogen, alkyl, cycloalkyl or aryl.

5. The formulation of claim 1 , wherein said second curable material is an acrylamide substituted by at least one hydrogen bond-forming chemical moiety.

6. The formulation of claim 5 , wherein said acrylamide is substituted by a chemical moiety selected from hydroxyalkyl, alkoxyalkyl, aminoalkyl, alkylaminoalkyl, dialkylaminoalkyl, carboxyalkyl, hidrazinoalkyl, carbamoylalkyl, and an alkyl substituted by any other hydrogen bond-forming chemical moiety as described herein.

7. The formulation of claim 1 , wherein a concentration of said first curable material ranges from 10 to 20 weight percent of the total weight of the formulation.

8. The formulation of claim 1 , wherein a concentration of said water-miscible polymer ranges from 30% to 80% by weight of the total weight of the formulation.

9. The formulation of claim 1 , being such that a cured support material formed upon exposing the formulation to a curing energy is dissolvable in an alkaline solution.

10. The formulation of claim 9 , being such that:
a dissolution time of a cured support material when immersed in said alkaline solution is at least 2-folds, or at least 4-folds, shorter than a dissolution time of a cured support material made of a comparable support material formulation that is absent said second curable material; and/or
a dissolution time of a 16-grams cube made of said cured support material and immersed in 800 mL of said alkaline solution is less than 10 hours, or less than 5 hours, or less than 2 hours.

11. The formulation of claim 9 , wherein said alkaline solution comprises an alkali metal hydroxide.

12. The formulation of claim 11 , wherein said alkaline solution further comprises an alkali metal silicate.

13. The formulation of claim 1 , being such that a 20 mm×20 mm×20 mm object made of the support material formulation and formed upon exposing the formulation to a curing energy is characterized by a mechanical strength of at least 100 N.

14. The formulation of claim 1 , being such that a cured support material formed upon exposing the formulation to a curing energy is characterized by a mechanical strength that is lower than a mechanical strength of a cured support material made of a comparable support material formulation that is absent said second curable material and comprises substantially the same total concentration of curable materials as the formulation, by no more than 50% or by no more than 40%, or by no more than 30%.

15. 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 modeling material formulation and a support material formulation, and wherein said support material formulation comprises the formulation of claim 1 .

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 comprised of a cured modeling material and a cured support material.

17. The method of claim 16 , further comprising removing said cured support material, to thereby obtain the three-dimensional model object.

18. The method of claim 17 , wherein said removing comprises contacting said cured support material with a cleaning solution.

19. The method of claim 18 , wherein said cleaning solution comprises an alkali metal hydroxide.

20. The method of claim 19 , wherein said cleaning solution further comprises an alkali metal silicate.

21. A three-dimensional object fabricated by the method of claim 15 .

22. The formulation of claim 1 , wherein X is NH; k is 2 or 3, and Y is hydroxyl.

23. The formulation of claim 1 , wherein X is NH; k is 2 or 3, and Y is dimethylamine.

24. The formulation of claim 1 , wherein a weight ratio between said mono-functional poly(alkylene glycol) acrylate and said multi-functional poly(alkylene glycol) acrylate in said first curable material is about 90:10.

Assignees

• Stratasys Ltd

Inventors

• Vidavsky Yuval
• Peri Dani
• Pokrass Mariana
• Levy Avraham
• Matzner Eynat

Classifications

• B33Y40/20

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

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• G03G9/08795

  characterised by their chemical properties, e.g. acidity, molecular weight, sensitivity to reactants · CPC title

• G03G9/08793

  Crosslinked polymers · CPC title

• G03G9/08733

  Polymers of unsaturated polycarboxylic acids · CPC title