Dual cure additive manufacturing resins for production of flame retardant objects

Patent metadata

Field	Value
Publication number	US-11834574-B2
Application number	US-202217808209-A
Country	US
Kind code	B2
Filing date	Jun 22, 2022
Priority date	Sep 10, 2018
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

The present invention concerns methods of forming a three-dimensional object, and polymerizable liquids such as dual cure resins useful for making a three-dimensional object by sterolithography, such as by continuous liquid interface production (CLIP), wherein the three-dimensional object is flame retardant.

First claim

What is claimed is:

1. A dual cure resin useful for making a three-dimensional object by stereolithography, comprising:
(a) light-polymerizable monomers and/or prepolymers that can participate in forming an intermediate object by stereolithography;
(b) heat-polymerizable monomers and/or prepolymers;
(c) a hardener, or a chain extender;
(d) a flame retardant synergist, said flame retardant synergist comprising antimony pentoxide; and
(e) optionally, an organic diluent in a viscosity-reducing effective amount,
wherein one or both of said: (a) heat-polymerizable monomers and/or prepolymers, and said (c) hardener or chain extender, comprises a flame retardant group in its chemical structure, said flame retardant group comprising a halogen group.

2. The resin of claim 1 , further comprising:
(f) a toughener.

3. The resin of claim 1 , wherein said hardener is present and comprises a polyamine, with said organic diluent included in an amount sufficient to dissolve said hardener in said resin.

4. The resin of claim 1 , wherein said resin comprises both of said hardener and said chain extender.

5. The resin of claim 1 , wherein said organic diluent is present and comprises N,N′-dimethylacrylamide, n-vinyl-2-pyrrolidone, n-vinyl formamide, n-vinyl caprolactam, acryloylmorpholine, or a mixture of two or more thereof.

6. The resin of claim 1 , further comprising at least one photoinitiator, optionally at least one dye, and optionally at least one filler.

7. The resin of claim 1 , wherein said resin comprises a cyanate ester or epoxy resin.

8. The resin of claim 1 , wherein said heat-polymerizable monomers and/or prepolymers comprise an epoxy, optionally in combination with a cyanate ester resin.

9. A method of making a three-dimensional object, comprising:
(a) providing the resin of claim 1 ;
(b) producing by stereolithography a three-dimensional intermediate from said dual cure resin, said intermediate having the same shape as, or a shape to be imparted to, said three-dimensional object, said stereolithography including irradiating the resin with light;
(c) optionally washing said intermediate; and then
(d) heating said intermediate to a temperature at which said heat-polymerizable monomers and/or prepolymers polymerize to produce said three-dimensional object.

10. The method of claim 9 , wherein said organic diluent is present and wherein said irradiating is carried out under conditions in which said organic diluent chemically reacts by an amount sufficient to increase the strength of said intermediate.

11. The method of claim 9 , wherein said light-polymerizable monomers and/or prepolymers form a solid polymer scaffold during said producing step (b), which scaffold degrades during said heating step (d) and forms a constituent necessary for the polymerization of said heat-polymerizable monomers and/or prepolymers.

12. The method of claim 9 , wherein said producing step (b) is carried out by bottom-up stereolithography.

13. The method of claim 9 , wherein said producing step (b) is carried out by continuous liquid interface production.

14. The resin of claim 1 , wherein said chain extender is present and wherein said resin further comprises a chain extender catalyst.

15. The resin of claim 14 , wherein said chain extender catalyst comprises an onium salt.

16. The resin of claim 1 , wherein the halogen group is bromine.

17. The resin of claim 1 , where the halogen group is present in an amount of from 1 to 20% by weight of the resin.

18. The resin of claim 1 , wherein the flame retardant synergist is present in an amount of from 0.1 to 5% by weight of the resin.

19. The resin of claim 1 , wherein the hardener and the organic diluent are present, and wherein the organic diluent solubilizes or dissolves said hardener in said resin.

20. The resin of claim 1 , wherein said antimony pentoxide is functionalized with ethoxylated amine.

Assignees

• Carbon Inc

Inventors

• Grover Ikpreet Singh
• Menyo Matthew S

Classifications

• C08L51/003 Primary

  grafted on to macromolecular compounds obtained by reactions only involving unsaturated carbon-to-carbon bonds (C08L51/04, C08L51/06 take precedence) · CPC title

• B29C64/124

  using layers of liquid which are selectively solidified · CPC title

• B29C64/35

  Cleaning · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B33Y40/20

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