Prepolymers exhibiting rapid development of physical properties

Patent metadata

Field	Value
Publication number	US-9920006-B2
Application number	US-201615194617-A
Country	US
Kind code	B2
Filing date	Jun 28, 2016
Priority date	Jun 28, 2016
Publication date	Mar 20, 2018
Grant date	Mar 20, 2018

Abstract

Hydroxyl-containing bis(alkenyl) ethers can be incorporated into the backbone of polythioether prepolymers and can be used as curing agents in thiol-terminated polythioether prepolymer compositions. Cured sealants prepared using compositions containing hydroxyl-containing bis(alkenyl) ether-containing polythioether prepolymers and/or hydroxyl-containing bis(alkenyl) ether curing agents exhibit improved physical properties such as rapid curing and compatibility with fillers suitable for use in aerospace sealant applications.

First claim

What is claimed is:

1. A polythioether prepolymer comprising a moiety of Formula (1):
—S—R 1 —[—S-A-S—R 1 —] s —S—  (1)

wherein,
s is an integer from 1 to 60;
each A is independently selected from a moiety of Formula (2a) and a moiety of Formula (3a):
—(CH 2 ) n —O—(CH 2 ) n —CH(—OH)—CH 2 —S—R 4 —S—CH 2 —CH(—OH)—(CH 2 ) n —O—(CH 2 ) n —  (2a)

—(CH 2 ) 2 —O—(R 2 —O) m —(CH 2 ) 2 —  (3a)

wherein,
each n is independently an integer from 1 to 4;

m is 0 to 50; and
each R 2 is selected from C 2-6 n-alkanediyl, C 3-6 branched alkanediyl, C 6-8 cycloalkanediyl, C 6-10 alkanecycloalkanediyl, and -[(—CH 2 —) p —O—] q -(—CH 2 —) r , wherein,
each p is independently an integer from 2 to 6;
q is an integer from 1 to 5; and
r is an integer from 2 to 10;

R 4 is selected from C 2-6 n-alkanediyl, C 3-6 branched alkanediyl, C 6-8 cycloalkanediyl, C 6-10 alkanecycloalkanediyl, and -[(—CH 2 —) p —X—] q -(—CH 2 —) r , wherein,
each X is independently selected from —O—, —S—, and —S—S—;
each p is an integer from 2 to 6;
q is an integer from 1 to 5; and
r is an integer from 2 to 6;

each R 1 is selected from C 2-10 alkanediyl, C 6-8 cycloalkanediyl, C 6-10 alkanecycloalkanediyl, and —[(—CHR—) p —X—] q —(CHR) l —, wherein each R is independently selected from hydrogen and methyl, wherein,
each X is independently selected from —O— and —S—;
each p is independently an integer from 2 to 6;
q is an integer from 1 to 5; and
r is an integer from 2 to 10; and
at least one A is a moiety of Formula (2a).

2. The polythioether prepolymer of claim 1 , wherein from 40 mol % to 60 mol % of the A moieties is a moiety of Formula (2a).

3. The polythioether prepolymer of claim 1 , wherein the polythioether prepolymer comprises a difunctional polythioether prepolymer of Formula (1a), a polyfunctional polythioether prepolymer of Formula (1b), or a combination thereof:
R 6 —S—R 1 —[—S-A-S—R 1 —] s —S—R 6   (1a)

{R 6 —S—R 1 —[—S-A-S—R 1 —] s —S—V′—} z B  (1b)

wherein,
each R 6 is selected from hydrogen and a moiety comprising a terminal group selected from a thiol, hydroxyl, isocyanate, alkenyl, epoxy, polyalkoxysilyl, and a Michael acceptor;
B comprises 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 terminal thiol groups; and

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

4. The polythioether prepolymer of claim 1 , wherein the polythioether prepolymer comprises a thiol-terminated polythioether prepolymer of Formula (1c), a thiol-terminated polythioether prepolymer of Formula (1d), or a combination thereof:
HS—R 1 —[—S-A-S—R 1 —] s —SH  (1c)

{HS—R 1 —[—S-A-S—R 1 —] s —S—V′—} z B  (1d)

wherein,
B comprises 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 terminal thiol groups; and

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

5. A composition comprising the polythioether prepolymer of claim 1 .

6. A part sealed with the composition of claim 5 .

7. A method of sealing a part, comprising:
applying the composition of claim 5 to a part; and
curing the applied composition to seal the part.

8. The part of claim 6 , wherein the part is a surface of an aerospace vehicle.

9. The method of claim 7 , wherein the part is a surface of an aerospace vehicle.

10. The polythioether prepolymer of claim 1 , wherein,
each n is 1; and
R 4 is selected from C 2-6 n-alkanediyl and -[(—CH 2 —) p —X—] q -(—CH 2 —) r -, wherein,
each X is independently selected from —O— and —S—;
each p is 2;
q is an integer from 1 to 5; and
r is 2.

11. The polythioether prepolymer of claim 1 , wherein R 1 is -[(—CH 2 —) p —X—] q -(—CH 2 —) r -, wherein each X is —O—; each p is 2, r is 2; and q is an integer from 1 to 5.

12. The polythioether prepolymer of claim 1 , wherein R 4 is selected from C 2-6 n-alkanediyl and -[(—CHR—) p —X—] q —(CHR) r —, wherein,
each X is independently selected from —O— and —S—;
each p is 2;
q is an integer from 1 to 5; and
r is 2.

13. The polythioether prepolymer of claim 1 , wherein each R 2 is independently selected from C 2-6 alkanediyl, 1,6-hexane-diyloxirane, and 2-(3-(allyloxy)propyl)oxirane.

14. The composition of claim 5 , wherein the composition comprises a sulfur-containing prepolymer that does not contain a pendent hydroxyl group.

15. The composition of claim 14 , wherein the sulfur-containing prepolymer that does not contain a pendent hydroxyl group is selected from a polythioether prepolymer, a polysulfide prepolymer, a sulfur-containing polyformal prepolymer, and a combination of any of the foregoing.

16. The composition of claim 5 , wherein the composition comprises a curing agent.

17. The composition of claim 16 , wherein the curing agent is selected from a polyalkenyl compound, a polyepoxide, a polyol, a polyisocyanate, a polyamine, and a polyfunctional Michael addition donor.

18. The composition of claim 5 , wherein,
the polythioether prepolymer comprises a thiol-terminated polythioether prepolymer selected from a thiol-terminated polythioether prepolymer of Formula (1c), a thiol-terminated polythioether prepolymer of Formula (1d), and a combination thereof:
HS—R 1 —[—S-A-S—R 1 —] s —SH  (1c)

{HS—R 1 —[—S-A-S—R 1 —] s —S—V′—} z B  (1d)

wherein,
B comprises 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 terminal thiol groups; and

each —V′— is derived from the reaction of —V with a thiol group; and

the curing agent comprises a polyepoxide.

Assignees

• Prc Desoto Int Inc

Inventors

• Cui Weibin
• Lin Renhe

Classifications

• C09K2003/1059

  Heat-curable materials · CPC title

• C09K3/1012

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

• C08G2190/00

  Compositions for sealing or packing joints · CPC title

• C08G75/12

  Polythioether-ethers (C08G75/0245 takes precedence) · CPC title

• C08G75/045

  from mercapto compounds and unsaturated compounds · CPC title