Prepolymers exhibiting rapid development of physical properties

Patent metadata

Field	Value
Publication number	US-10597360-B2
Application number	US-201815886242-A
Country	US
Kind code	B2
Filing date	Feb 1, 2018
Priority date	Jun 28, 2016
Publication date	Mar 24, 2020
Grant date	Mar 24, 2020

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 reaction products of reactants comprising:
(a) a polythiol comprising a dithiol of Formula (5):
HS—R 1 —SH  (5)

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

(b) a hydroxyl-containing bis(alkenyl) ether of Formula (2):
CH 2 =CH—(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 —CH═CH 2   (2)

wherein,
each n is independently an integer from 1 to 4; and
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 independently an integer from 2 to 6;
q is an integer from 1 to 5; and
r is an integer from 2 to 6; and

(c) a divinyl ether of Formula (3):
CH 2 =CH—O—(—R 2 —O—) m —CH═CH 2   (3)

wherein,
m is an integer from 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.

2. The polythioether prepolymer of claim 1 , wherein the reactants further comprise a polyfunctionalizing agent of Formula (7):
B(—V) z   (7)

wherein,
B comprises a core of a z-valent polyfunctionalizing agent B(—V) z ;
z is an integer from 3 to 6; and
each —V is independently a moiety comprising a terminal thiol group or a terminal alkenyl group.

3. The polythioether prepolymer of claim 1 , wherein the polyfunctionalizing agent comprises triallyl cyanurate.

4. The polythioether prepolymer of claim 2 , wherein,
each n is selected from 1 and 2;
each of R 1 and R 4 is independently 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 independently selected from 2 and 3;
q is an integer from 1 to 5;
r is selected from 2 and 3;
m is an integer from 0 to 4; and
R 2 is C 2-6 n-alkanediyl.

5. The polythioether prepolymer of claim 1 , wherein the dithiol of Formula (5) comprises 2,2′-(ethane-1,2-diylbis(oxy))bis(ethane-1-thiol), 2,2′-thiobis(ethane-1-thiol), 2,2′-oxybis(ethane-1-thiol), propane-1,3-dithiol, 2-((2-(2-mercaptoethoxy)ethyl)thio)ethane-1-thiol, or a combination of any of the foregoing.

6. The polythioether prepolymer of claim 1 , wherein the hydroxyl-containing bis(alkenyl) ether comprises reaction products of reactants comprising:
(a) a polythiol comprising a dithiol of Formula (6):
HS—R 4 —SH  (6)

wherein 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 independently an integer from 2 to 6;
q is an integer from 1 to 5; and
r is an integer from 2 to 6; and

(b) a compound of Formula (8):

wherein each n is independently an integer from 1 to 4.

7. The polythioether prepolymer of claim 6 , wherein,
the dithiol of Formula (6) comprises 3,6-dioxa-1,8-octanedithiol (DMDO), dimercaptodiethylsulfide (2,2′-thiobis(ethane-1-thiol) (DMDS), 2,2′-oxybis(ethane-1-thiol), 1,2-ethanedithiol, or a combination of any of the foregoing; and
the compound of Formula (8) comprises allyl glycidyl ether.

8. The polythioether prepolymer of claim 1 , wherein the hydroxyl-containing bis(alkenyl) ether of Formula (2) comprises 4,11,14,21-tetraoxa-8,17-dithiatetracosa-1,23-diene-6,19-diol; Formula (2b), 4,18-dioxa-8,11,14-trithiahenicosa-1,20-diene-6,16-diol; Formula (2c), 4,15-dioxa-8,11-dithiaoctadeca-1,17-diene-6,13-diol; Formula (2e), 1,18-trioxa-8,14-dithiahenicosa-1,20-diene-6,16-diol; Formula (2d), or a combination of any of the foregoing.

9. The polythioether prepolymer of claim 1 , wherein the divinyl ether of Formula (3) comprises divinyl ether, ethylene glycol divinyl ether (EG-DVE), butanediol divinyl ether (BD-DVE), hexanediol divinyl ether (HD-DVE), diethylene glycol divinyl ether (DEG-DVE), triethylene glycol divinyl ether (TEG-DVE), tetraethylene glycol divinyl ether, cyclohexanedimethanol divinyl ether, or a combination of any of the foregoing.

10. The polythioether prepolymer of claim 2 , wherein,
the dithiol comprises 1,8-dimercapto-3,6-dioxaoctane (DMDO);
the hydroxyl-containing bis(alkenyl) ether comprises 4,11,14,21-tetraoxa-8,17-dithiatetracosa-1,23-diene-6,19-diol;
the divinyl ether comprises diethylene glycol divinyl ether, triethylene glycol divinyl ether, or a combination thereof; and
the polyfunctionalizing agent comprises triallyl cyanurate.

11. The polythioether prepolymer of claim 1 , wherein the reactants comprise:
from 20 mol % to 80 mol % of the hydroxyl-containing bis(alkenyl) ether; and
from 20 mol % to 80 mol % of the divinyl ether,
wherein mol % is based on the total moles of the hydroxyl-containing bis(alkenyl)ether and the divinyl ether.

12. The polythioether prepolymer of claim 1 , wherein the reactants comprise:
from 40 mol % to 60 mol % of the hydroxyl-containing bis(alkenyl) ether; and
from 40 mol % to 60 mol % of the divinyl ether,
wherein mol % is based on the total moles of the hydroxyl-containing bis(alkenyl)ether and the divinyl ether.

13. The polythioether prepolymer of claim 1 , wherein the polythioether prepolymer comprises two or more terminal thiol groups.

14. The polythioether of claim 1 wherein the polythioether prepolymer comprises two or more terminal alkenyl groups.

15. A polythioether prepolymer comprising reaction products of reactants comprising:
the polythioether prepolymer of claim 1 ; and
a compound comprising a group reactive with a terminal group of the polythioether prepolymer of claim 1 , and a reactive functional group.

16. The polythioether prepolymer of claim 15 , wherein,
the group reactive with a terminal group of the polythioether prepolymer is selected from a thiol group, an isocyanate group, an alkenyl group, an epoxy group, and a Michael acceptor group; and
the reactive functional group is selected from a hydroxyl group, an isocyanate group, an alkenyl group, an epoxy group, a polyalkoxysilyl group, and a Michael acceptor group.

17. The polythioether prepolymer of claim 15 , wherein the polythioether prepolymer comprises at least one terminal group selected from a thiol group, a hydroxyl group, an isocyanate group, an alkenyl group, an epoxy group, a polyalkoxysilyl group, and a Michael acceptor group.

18. The polythioether prepolymer of claim 1 , wherein the polythioether prepolymer has an average functionality between 2 and 3.

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

20. A cured sealant prepared from the composition of claim 19 .

21. A part comprising the cured sealant of claim 20 .

Assignees

• Prc Desoto Int Inc

Inventors

• Cui Weibin
• Lin Renhe

Classifications

• C08G75/12

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

• 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

• C08G75/02 Primary

  Polythioethers · CPC title