Dual cure sealants

Patent metadata

Field	Value
Publication number	US-11655340-B2
Application number	US-201816620759-A
Country	US
Kind code	B2
Filing date	Jun 8, 2018
Priority date	Jun 9, 2017
Publication date	May 23, 2023
Grant date	May 23, 2023

Abstract

Compositions that are curable by free radical redox reactions are disclosed. Free radical curing reactions between polythiols and polyalkyenyls are initiated by the reaction of metal complexes and organic peroxides. The compositions are useful as sealants.

First claim

What is claimed is:

1. A composition comprising:
a polythiol, wherein the polythiol comprises a thiol-terminated polythioether prepolymer, wherein the thiol-terminated polythioether prepolymer comprises a moiety having the structure of Formula (2c):
—S—R 1 —[S-A-S—R 1 -] n —S—  (2c)

wherein,
n is an integer from 1 to 60;
each R 1 is independently selected from C 2-10 alkanediyl, C 6-8 cycloalkanediyl, C 6-14 alkanecycloalkanediyl, C 5-8 heterocycloalkanediyl, and —[(CHR 3 ) p —X—] q (CHR 3 )—, wherein,
p is an integer from 2 to 6;
q is an integer from 1 to 5;
r is an integer from 2 to 10;
each R 3 is independently selected from hydrogen and methyl; and
each X is independently selected from O, S, and NR, wherein R is selected from hydrogen and methyl; and

each A is independently a moiety derived from a polyvinyl ether of Formula (3) and a polyalkenyl polyfunctionalizing agent of Formula (4):
CH 2 ═CH—O—(R 2 —O) m —CH═CH 2   (3)

B(—R 70 —CH═CH 2 ) z   (4)

wherein,
m is an integer from 0 to 50;
each R 2 is independently selected from C 1-10 alkanediyl, C 6-8 cycloalkanediyl, C 6-14 alkanecycloalkanediyl, and —RCHR) p —X—WCHR 3 ),—, wherein p, q, r, R 3 , and X are as defined for R 1 ;
B represents a core of a z-valent, polyalkenyl polyfunctionalizing agent B(—R 70 —CH═CH 2 ) z wherein,
z is an integer from 3 to 6; and

each R 70 is independently selected from C 1-10 alkanediyl, C 1-10 heteroalkanediyl, substituted C 1-10 alkanediyl, and substituted C 1-10 heteroalkanediyl;
a polyalkenyl, wherein the polyalkenyl comprises an alkenyl-terminated prepolymer, a polyalkenyl monomer, or a combination thereof;
a metal complex; and
an organic peroxide.

2. The composition of claim 1 , wherein the polyalkenyl monomer comprises a bis(alkenyl) ether.

3. The composition of claim 1 , wherein the metal complex comprises cobalt(II)bis(2-ethyl hexanoate), manganese (III)(acetylacetonate) 3 , iron(III)(acetylacetonate)3, or a combination of any of the foregoing.

4. The composition of claim 1 , wherein the organic peroxide comprises tert-butyl peroxybenzoate.

5. The composition of claim 1 , wherein the metal complex comprises a metal complex of Co(II), Co(III), Mn(II), Mn(III), Fe(II), Fe(III), Cu(II), V(III), or a combination of any of the foregoing.

6. The composition of claim 1 , wherein the composition comprises a free radical photoinitiator.

7. The composition of claim 1 , wherein the composition comprises a hydrogen donor.

8. The composition of claim 7 , wherein the hydrogen donor comprises a primary amine, a secondary amine or a combination thereof.

9. The composition of claim 1 , wherein the composition comprises from 0.01 wt % to 2 wt % of a primary amine, a secondary amine, a tertiary amine, or a combination thereof, wherein wt % is based on the total weight of the composition.

10. The composition of claim 1 , wherein the composition comprises:
from 45 wt % to 85 wt % of the thiol-terminated polythioether prepolymer;
from 1 wt % to 10 wt % of the polyalkenyl;
from 0.001 wt % to 2 wt % of the metal complex; and
from 0.1 wt % to 5 wt % of the organic peroxide,
wherein wt % is based on the total weight of the composition.

11. The composition of claim 1 , wherein the composition is curable under dark conditions.

12. The composition of claim 1 , wherein,
the composition is curable upon exposure to actinic radiation; and
the composition is curable without exposure to actinic radiation.

13. The composition of claim 1 , wherein the composition is curable at a temperature from 20° C. to 30° C.

14. A cured sealant prepared from the composition of claim 1 .

15. A part sealed with the cured sealant of claim 14 .

16. A vehicle comprising the cured sealant of claim 14 .

17. An aerospace vehicle comprising the cured sealant of claim 14 .

18. A method of sealing a part comprising:
applying the composition of claim 1 to a part; and
allowing the applied composition to cure, to seal the part.

19. The composition of claim 1 , wherein the thiol-terminated polythioether prepolymer comprises a moiety of Formula (2):
—R 1 —[S—(CH 2 ) 2 —O—(R 2 —O—) m (CH 2 ) 2 —S—R 1 ] n —  (2).

20. The composition of claim 1 , wherein the thiol-terminated polythioether prepolymer comprises a thiol-terminated polythioether prepolymer of Formula (2a), a thiol-terminated polythioether prepolymer of Formula (2b), or a combination thereof:
HS—R 1 —[S—(CH 2 ) 2 —O—(R 2 —O) m (CH 2 ) 2 —S—R 1 —] n SH  (2a)

{HS—R—[S—(CH 2 ) 2 —O—(R 2 —O—) m (CH 2 ) 2 —S—R 1 —] n S-V′-} z B  (2b)

wherein,
each R 1 can independently be selected from C 2-10 alkanediyl, C 6-8 cycloalkanediyl, C 6-14 alkanecycloalkanediyl, C 5-8 heterocycloalkanediyl, and —[(CHR 3 ) p —X—] q (CHR 3 )—, wherein,
p is an integer from 2 to 6;
q is an integer from 1 to 5;
r is an integer from 2 to 10;
each R 3 independently be selected from hydrogen and methyl; and
each X can independently be selected from 0, S, and NR, wherein R can be selected from hydrogen and methyl;

each R 2 can independently be selected from C 1-10 alkanediyl, C 6-8 cycloalkanediyl, C 6-14 alkanecycloalkanediyl, and —[(CHR 3 ) p —X—] q (CHR 3 )—, wherein p, q, r, R 3 , and X are as defined as for R 1 ;
m is an integer from 0 to 50;
n is an integer from 1 to 60;
B represents a core of a z-valent, polyfunctionalizing agent B(—V) z wherein,
z is an integer from 3 to 6; and
each V is a moiety comprising a terminal group reactive with a thiol; and

each —V′— is derived from the reaction of —V with a thiol.

21. The composition of claim 1 , wherein the polythiol further comprises a polythiol monomer.

Assignees

• Prc Desoto Int Inc

Inventors

• Liu Jiancheng
• Pathak Srikant
• Virnelson Bruce

Classifications

• C08G75/025

  Preparatory processes · CPC title

• C08J7/18

  using wave energy or particle radiation · CPC title

• C08G75/00 Primary

  Macromolecular compounds obtained by reactions forming a linkage containing sulfur with or without nitrogen, oxygen, or carbon in the main chain of the macromolecule · CPC title

• C09K3/1012

  Sulfur-containing polymers, e.g. polysulfides · CPC title

• C08L81/02

  Polythioethers; Polythioether-ethers · CPC title