Production of low density products by additive manufacturing

Patent metadata

Field	Value
Publication number	US-11292186-B2
Application number	US-201916617042-A
Country	US
Kind code	B2
Filing date	Jul 29, 2019
Priority date	Aug 1, 2018
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

Provided herein according to some embodiments is polymerizable liquid useful for the production of a three-dimensional object by additive manufacturing, said polymerizable liquid comprising a mixture of: (a) at least one photopolymerizable component; (b) a photoinitiator; (c) at least one heat polymerizable component; and (d) heat expandable microspheres. A method of making a three-dimensional object from such a polymerizable liquid by additive manufacturing and objects so produced are also provided.

First claim

We claim:

1. A method of making a three-dimensional object, comprising:
(a) producing an intermediate object from a polymerizable liquid by additive manufacturing, said polymerizable liquid comprising a mixture of:
(i) at least one photopolymerizable component,
(ii) a photoinitiator,
(iii) at least one heat polymerizable component, and
(iv) heat expandable microspheres;

(b) optionally cleaning said intermediate object; and then
(c) heating and/or microwave irradiating said intermediate object for a time and at a temperature sufficient to expand said microspheres, further cure said intermediate object, and form said three-dimensional object,
wherein said intermediate object comprises a polymer scaffold produced by the photopolymerization of said photopolymerizable component; and wherein said polymer scaffold degrades during said heating step, and forms a degradation product that in turn reacts with said at least one heat polymerizable component to form said three-dimensional object.

2. The method of claim 1 , wherein said heating and/or microwave irradiating step is carried out under conditions in which the modulus of elasticity of said intermediate object decreases during at least a portion of said heating and/or microwave irradiating step.

3. The method of claim 1 , wherein said three-dimensional object is rigid, flexible, or elastic.

4. The method of claim 1 , wherein said three-dimensional object is comprised of polyurethane, silicone, or epoxy.

5. The method of claim 1 , wherein said heat polymerizable component comprises at least one precursor to a polyurethane, polyurea, or copolymer thereof, a silicone resin, a cyanate ester resin, or a natural rubber.

6. The method of claim 1 , wherein said intermediate object comprises a polymer scaffold produced by the photopolymerization of said photopolymerizable component; and wherein said polymer scaffold softens during said heating step.

7. The method of claim 6 , wherein said heat polymerizable component comprises an epoxy resin.

8. The method of claim 1 , wherein said microspheres comprise a hollow thermally expandable shell and a propellant contained in said shell.

9. The method of claim 1 , wherein said producing step is carried out by bottom-up stereolithography.

10. The method of claim 1 , wherein said producing step is carried out by continuous liquid interface production.

11. The method of claim 1 , wherein said heat expandable microspheres are present in an amount of from 1 percent by weight to 10 percent by weight.

12. The method of claim 1 , wherein the volume of said intermediate object is increased by at least 5 percent by said heating and/or microwave irradiating step.

13. The method of claim 1 , wherein said three-dimensional object comprises a regular or irregular open-cell lattice.

14. The method of claim 1 , wherein said three-dimensional object comprises a cushion, shock absorber, thermal insulator, or electric insulator.

15. The method of claim 1 , wherein said heat polymerizable component comprises at least one precursor to a polyurethane, polyurea, or copolymer thereof.

Assignees

• Carbon Inc

Inventors

• Poelma Justin
• Rolland Jason P

Classifications

• B29C64/188

  involving additional operations performed on the added layers, e.g. smoothing, grinding or thickness control (surface shaping B29C59/00; after-treatment of articles without altering their shape B29C71/00) · CPC title

• B29L2031/3412

  Insulators · CPC title

• G03F7/0037

  Production of three-dimensional images · CPC title

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• B29C64/124 Primary

  using layers of liquid which are selectively solidified · CPC title