Polyolefin-based formulations for additive manufacturing

Patent metadata

Field	Value
Publication number	US-2022153888-A1
Application number	US-202017098109-A
Country	US
Kind code	A1
Filing date	Nov 13, 2020
Priority date	Nov 13, 2020
Publication date	May 19, 2022
Grant date	—

Abstract

A polyolefin-based ink for additive manufacturing includes a polyolefin copolymer having a molecular weight no more than five times the entanglement molecular weight of the polyolefin copolymer, wherein the polyolefin copolymer comprises at least one type of functional group for crosslinking. A product of additive manufacturing with a polyolefin-based ink includes a three-dimensional structure including an extruded continuous filament arranged in a predefined pattern. The continuous filament includes a polyolefin matrix having a microstructure, where the microstructure is retained after curing.

First claim

What is claimed is:

1 . A polyolefin-based ink for additive manufacturing, the ink comprising:
a polyolefin copolymer having a molecular weight no more than five times the entanglement molecular weight of the polyolefin copolymer, wherein the polyolefin copolymer comprises at least one type of functional group for crosslinking.

2 . The ink as recited in claim 1 , wherein the at least one type of functional group for crosslinking is selected from the group consisting of: a vinyl group, an oleyl group, a hydroxyl group, an amine group, an epoxy groups, a thiol groups, a protected carbamate group, a carboxylate groups, a xylene groups, and a xylenol group.

3 . The ink as recited in claim 1 , wherein the polyolefin copolymer comprises at least one type of monomeric unit (selected from the group consisting of: ethylene, propylene, butene, pentene, hexene, heptene, oxtene, vinylacetate, acrylic monomeric units such as methylacrylate, ethylacrylate, propylacrylate, n- and t-butylacrylate, pentylacrylate, hexylacrylate, methylmethacrylate, cyclohexylmethacrylate, isobutylene, isopentene, isoprene, and chloroprene.

4 . The ink as recited in claim 3 , wherein the polyolefin copolymer comprises at least two different types of the monomeric units.

5 . The ink as recited in claim 1 , wherein the molecular weight is no more than twice the entanglement molecular weight of the polyolefin copolymer.

6 . The ink as recited in claim 1 , wherein the polyolefin copolymer comprises an ethylene monomeric unit, a propylene monomeric unit, and a diene monomeric unit.

7 . The ink as recited in claim 6 , wherein a concentration of the ethylene monomeric unit is in a range of greater than 50 weight. % to about 75 weight. % of a total weight of the polyolefin copolymer.

8 . The ink as recited in claim 7 , wherein the ink has a crystallization temperature in a range of about 40 degrees Celsius to about 60 degrees Celsius.

9 . The ink as recited in claim 6 , wherein a concentration of the propylene monomeric unit is in a range of greater than 25 weight. % to about 50 weight. % of a total weight of the polyolefin copolymer.

10 . The ink as recited in claim 6 , wherein a concentration of the diene monomeric unit is in a range of greater than 0 weight. % to about 10 weight. % of a total weight of the polyolefin copolymer.

11 . The ink as recited in claim 1 , comprising a curing agent.

12 . The ink as recited in claim 1 , comprising a reinforcing filler and/or a reinforcing fiber.

13 . The ink as recited in claim 1 , comprising a rheology modifying additive.

14 . The ink as recited in claim 1 , comprising an inhibitor.

15 . The ink as recited in claim 1 , comprising an additive selected from the group consisting of: particulates, a porogen, a dispersant, a surfactant, a dye, a pigment, a physical blowing agent, a chemical blowing agent, and microballoons.

16 . A product of additive manufacturing with a polyolefin-based ink, the product comprising:
a three-dimensional printed structure comprising:
an extruded continuous filament arranged in a predefined pattern,
the continuous filament comprising a polyolefin matrix having a microstructure, wherein the microstructure is retained after curing.

17 . The product as recited in claim 16 , wherein the polyolefin matrix includes an ethylene monomeric unit, a propylene monomeric unit, and a diene monomeric unit.

18 . The product as recited in claim 16 , the microstructure includes a plurality of intra-filament pores.

19 . The product as recited in claim 16 , wherein the product is resistant to chemical degradation.

20 . The product as recited in claim 16 , wherein the product is resistant to radiation degradation.

21 . The product as recited in claim 16 , wherein the product has a use temperature in a range of greater than −60 degrees Celsius to less than 200 degrees Celsius.

22 . The product as recited in claim 16 , wherein the polyolefin matrix comprises magnetic material.

23 . The product as recited in claim 16 , wherein the product has thermal shape-memory behavior.

24 . A method of forming a three-dimensional structure comprising a polyolefin-containing matrix, the method comprising:
extruding a continuous filament of a polyolefin mixture through a nozzle to form at least a portion of a printed three-dimensional structure arranged in a predefined pattern, the polyolefin mixture comprising a polyolefin copolymer having a molecular weight no more than five times the entanglement molecular weight of the polyolefin copolymer, wherein the polyolefin copolymer comprises at least one type of functional group for crosslinking; and curing the printed three-dimensional structure to at least a predefined extent to form the polyolefin matrix.

25 . The method as recited in claim 24 , wherein the polyolefin copolymer comprises an ethylene monomeric unit, a propylene monomeric unit, and a diene monomeric unit.

26 . The method as recited in claim 24 , wherein the polyolefin mixture includes a curing agent and a crosslinking agent.

27 . The method as recited in claim 24 , wherein a concentration of the ethylene monomeric unit is in a range of about 50 weight. % to about 70 weight. % of a total weight of the polyolefin copolymer.

28 . The method of claim 24 , wherein the polyolefin mixture has a crystallization temperature in a range of about 40 degrees Celsius to 60 degrees Celsius.

29 . The method as recited in claim 24 , the polyolefin mixture comprises a porogen, wherein after curing the printed three-dimensional structure, the method further comprises:
leaching the porogen from the polyolefin matrix to result in a plurality of pores forming interconnected channels through the polyolefin matrix of the three-dimensional structure.

30 . The method as recited in claim 24 , further comprising, heating the three-dimensional structure having the polyolefin matrix for setting the polyolefin matrix.

Assignees

• L Livermore Nat Security Llc

Inventors

• Wilson Thomas S
• Golobic Alexandra Melody
• Lenhardt Jeremy M
• Schmidt Spencer

Classifications

• C09D123/16 Primary

  Elastomeric} ethylene-propylene or ethylene-propylene-diene copolymers {, e.g. EPR and EPDM rubbers · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B33Y70/00

  Materials specially adapted for additive manufacturing · CPC title

• B29C64/118

  using filamentary material being melted, e.g. fused deposition modelling [FDM] · CPC title

• C08L23/16

  Ethylene-propylene or ethylene-propylene-diene copolymers · CPC title