Core-shell particles, compositions incorporating the core-shell particles and methods of making the same

Patent metadata

Field	Value
Publication number	US-9856359-B2
Application number	US-201514681747-A
Country	US
Kind code	B2
Filing date	Apr 8, 2015
Priority date	Apr 8, 2015
Publication date	Jan 2, 2018
Grant date	Jan 2, 2018

Abstract

A low viscosity polysulfide sealant composition. The composition comprises a curable polysulfide polymer; a crosslinking agent; and a plurality of core-shell particles. The core-shell particles comprise: a core comprising a ferromagnetic material; and a shell comprising silica treated with an organic sulfur containing compound. The shell is capable of bonding with the polysulfide polymer.

First claim

What is claimed is:

1. A polysulfide sealant composition, comprising:
a curable polysulfide polymer;
a crosslinking agent; and
a plurality of core-shell particles comprising:
a core comprising a ferromagnetic material; and
a shell comprising silica treated with an organic sulfur-containing compound, the shell being capable of bonding with the polysulfide polymer.

2. The composition of claim 1 , wherein the polysulfide polymer is chosen from poly(ethylformal disulfide), poly(thioether), and combinations thereof.

3. The composition of claim 1 , wherein the core-shell particles have a primary particle size ranging from about 10 nm to about 1000 nm.

4. The composition of claim 1 , wherein the core-shell particles have a primary particle size ranging from about 50 nm to about 150 nm.

5. The composition of claim 1 , wherein the ferromagnetic material comprises a ferromagnetic metal or ferromagnetic metal oxide.

6. The composition of claim 1 , wherein the ferromagnetic material comprises at least one material chosen from Fe 3 O 4 , Fe, Co, or Ni.

7. The composition of claim 1 , wherein the organic sulfur-containing compound is an alkoxy silane having at least one thiol group.

8. The composition of claim 1 , wherein the organic sulfur-containing compound is a sulfur functionalized alkoxy silane chosen from bis[3-(triethoxysilyl)propyl]tetrasulfide, 3-mercaptopropyltrimethoxysilane, 3-mercaptopropyltriethoxysilane, or 3-mercaptopropylmethyldimethoxysilane.

9. The composition of claim 8 , wherein the shell is formed using tetraethyl orthosilicate.

10. The composition of claim 1 , wherein the core-shell particles include silyl ether functional groups attached to a surface of the shell.

11. The composition of claim 1 , further comprising a powder comprising MnO 2 particles.

12. The composition of claim 11 , wherein the MnO 2 particles have a particle size of 100 nm or less.

13. A process comprising:
coating a substrate with a polysulfide sealant composition to form a sealant layer, the polysulfide sealant composition having a first viscosity and comprising:
(a) a curable polysulfide polymer; and
(b) a plurality of core-shell particles comprising:
(i) a core comprising a ferromagnetic material; and
(ii) a shell comprising silica treated with an organic sulfur-containing compound capable of bonding with the polysulfide polymer and the substrate;

exposing the sealant layer to a magnetic field to consolidate the core-shell particles at an interface between the sealant layer and the substrate.

14. The process of claim 13 , further comprising coating the sealant layer with a second polysulfide sealant having a second viscosity that is greater than the first viscosity to form a second sealant layer.

15. The process of claim 13 , further comprising exposing the core-shell particles to a changing magnetic field so as to inductively heat the core-shell particles.

Assignees

• Boeing Co

Inventors

• Nowak Andrew P
• Yang Sophia S
• Boundy Thomas I
• Hansen Darrin M
• Adjorlolo Alain A
• Pajel Carissa A
• Ghantous Eliana V

Classifications

• B22F1/16

  Metallic particles coated with a non-metal (coated with lubricating or binding agents or with organic material B22F1/10) · CPC title

• B22F1/10

  Metallic powder containing lubricating or binding agents; Metallic powder containing organic material · CPC title

• B82Y30/00

  Nanotechnology for materials or surface science, e.g. nanocomposites · CPC title

• C08L81/04

  Polysulfides · CPC title

• B22F2999/00

  Aspects linked to processes or compositions used in powder metallurgy · CPC title