Cure-on-demand moisture-curable urethane-containing fuel resistant prepolymers and compositions thereof

Patent metadata

Field	Value
Publication number	US-9518197-B2
Application number	US-201514964904-A
Country	US
Kind code	B2
Filing date	Dec 10, 2015
Priority date	Mar 7, 2014
Publication date	Dec 13, 2016
Grant date	Dec 13, 2016

Abstract

Cure-on-demand, moisture-curable, urethane-containing prepolymers having urethanes incorporated into a sulfur-containing prepolymer backbone and compositions thereof for use in sealant applications are disclosed. The cure-on-demand moisture-curable urethane-containing prepolymers are terminated with polyalkoxysilyl groups. The compositions contain a controlled-release moisture cure catalyst. Compositions containing the prepolymers provide cured sealants exhibiting improved tensile strength.

First claim

What is claimed is:

1. A composition comprising:
(a) a moisture-curable urethane-containing prepolymer comprising a reaction product of reactants comprising:
(i) an isocyanate-terminated urethane-containing adduct comprising the reaction product of reactants comprising:
a hydroxyl-terminated sulfur-containing adduct comprising the reaction product of reactants comprising a hydroxy vinyl ether and a thiol-terminated sulfur-containing prepolymer, wherein the thiol-terminated sulfur-containing prepolymer comprises a thiol-terminated polythioether, a thiol-terminated polysulfide, a thiol-terminated sulfur-containing polyformal, or a combination of any of the foregoing; and
a diisocyanate; and

(ii) a compound comprising:
a group reactive with an isocyanate group; and
at least one polyalkoxysilyl group; and

(b) a controlled release moisture cure catalyst.

2. The composition of claim 1 , wherein the hydroxyl-terminated sulfur-containing adduct comprises a hydroxyl-terminated polythioether adduct of Formula (10a), a hydroxyl-terminated polythioether adduct of Formula (10b), or a combination thereof:
R 6 —S—R 1 —[—S—(CH 2 ) s —O—(R 2 —O) m —(CH 2 ) 2 —S—R 1 —] n —S—R 6   (10a)

{R 6 —S—R 1 —[—S—(CH 2 ) s —O—(R 2 —O) m —(CH 2 ) 2 —S—R 1 —] n —S—V′—} z B  (10b)

wherein,
each R 1 independently is selected from C 2-10 alkanediyl, C 6-8 cycloalkanediyl, C 6-10 alkanecycloalkanediyl, C 5-8 heterocycloalkanediyl, and —[(—CHR 3 —) p —X—] q —(—CHR 3 —) r —, 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;

each R 2 is independently selected from C 1-10 alkanediyl, C 6-8 cycloalkanediyl, C 6-14 alkanecycloalkanediyl, and —[(—CHR 3 —) p —X—] q —(—CHR 3 —) r —, wherein p, q, r, R 3 , and X are as defined for R 1 ;
m is an integer from 0 to 50;
n is an integer from 1 to 60; and
s is an integer from 2 to 6;
each R 6 is independently selected from —CH 2 —CH 2 —O—R 13 —OH, wherein each R 13 is C 2-10 alkanediyl; and
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 group; and

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

3. The composition of claim 1 , wherein the thiol-terminated sulfur-containing prepolymer comprises a thiol-terminated polythioether prepolymer of Formula (6a), a thiol-terminated polythioether prepolymer of Formula (6b), or a combination thereof:
HS—R 1 —[—S—(CH 2 ) s —O—(R 2 —O) m —(CH 2 ) 2 —S—R 1 —] n —SH  (6a)

{HS—R 1 —[—S—(CH 2 ) s —O—(R 2 —O) m —(CH 2 ) 2 —S—R 1 —] n —S—V′—} z B  (6b)

wherein:
each R 1 independently is 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 —) r —, 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;

each R 2 is independently selected from C 1-10 alkanediyl, C 6-8 cycloalkanediyl, C 6-14 alkanecycloalkanediyl, and —[(—CHR 3 —) p —X—] q —(—CHR 3 —) r —, 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;
s is an integer from 2 to 6;
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 group comprising a terminal group reactive with a thiol group; and

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

4. The composition of claim 1 , wherein the isocyanate-terminated urethane-containing adduct comprises an isocyanate-terminated urethane-containing polythioether, an isocyanate-terminated urethane-containing polysulfide, an isocyanate-terminated urethane-containing sulfur-containing polyformal, or a combination of any of the foregoing.

5. The composition of claim 1 , wherein the compound (ii) comprises an aminosilane.

6. The composition of claim 5 , wherein the aminosilane comprises (3-aminopropyl)triethoxysilane.

7. The composition of claim 1 , comprising dimethoxy(methyl)(vinyl)silane.

8. The composition of claim 1 , formulated as a sealant.

9. A cured sealant, prepared from the composition of claim 8 .

10. A part sealed with the composition of claim 8 .

11. A method of sealing a surface, comprising:
applying the composition of claim 8 to at least a portion of a surface;
activating the controlled release moisture cure catalyst; and
curing the applied composition to seal the surface.

12. A composition comprising:
(a) a moisture-curable urethane-containing prepolymer comprising a moisture-curable urethane-containing prepolymer of Formula (2a), a moisture-curable urethane-containing prepolymer of Formula (2b), or a combination thereof:
R 30 —C(═O)—NH—R 20 —NH—C(═O)—[—R 60 —C(═O)—NH—R 20 —NH—C(═O)—] w —R 60 —C(═O)—NH—R 20 —NH—C(═O)—R 30   (2a)

B{—V′—S—R 50 —S—(CH 2 ) 2 —O—R 13 —O—[—C(═O)—NH—R 20 —NH—C(═O)—R 60 —] w —C(═O)—NH—R 20 —NH—C(═O)—R 30 } z   (2b)

wherein,
w is an integer from 1 to 100;
each R 13 independently comprises C 2-10 alkanediyl;
each R 20 independently comprises a core of a diisocyanate;
each R 30 independently is a moiety comprising a terminal polyalkoxysilyl group;
each R 50 independently comprises a core of a sulfur-containing prepolymer, wherein the sulfur-containing prepolymer comprises a polythioether, a polysulfide, a sulfur-containing polyformal, or a combination of any of the foregoing;
each R 60 independently comprises a moiety having the structure of Formula (3):
—O—R 13 —O—(CH 2 ) 2 —S—R 50 —S—(CH 2 ) 2 —O—R 13 —O—  (3)

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 group; and

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

(b) a controlled release moisture cure catalyst.

13. The composition of claim 12 , wherein each R 30 comprises a moiety of Formula (4a), a moiety of Formula (4b), or a combination thereof:
—NH(—R 9 —Si(—R 7 ) x (—OR 7 ) 3-x )  (4a)

—N(—R 9 —Si(—R 7 ) x (—OR 7 ) 3-x ) 2   (4b)

wherein,
x is selected from 0, 1, and 2;
each R 7 is independently selected from C 1-4 alkyl; and
each R 9 is independently C 1-6 alkanediyl.

14. The composition of claim 12 , wherein each R 50 comprises a moiety having the structure of Formula (5):
—R 1 —[—S—(CH 2 ) s —O—(R 2 —O) m —(CH 2 ) 2 —S—R 1 —] n —  (5)

wherein,
each R 1 independently is 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 —) r —, 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;

each R 2 is independently selected from C 1-10 alkanediyl, C 6-8 cycloalkanediyl, C 6-14 alkanecycloalkanediyl, and —[(—CHR 3 —) p —X—] q —(—CHR 3 —) r —, 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

Assignees

• Prc Desoto Int Inc

Inventors

• Keledjian Raquel
• Lin Renhe

Classifications

• C08G18/52 Primary

  Polythioethers · CPC title

• C08G18/16

  Catalysts (catalysts in general B01J) · CPC title

• C08G18/307

  Atmospheric humidity · CPC title

• C08G18/10

  Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step · CPC title

• C08G2190/00

  Compositions for sealing or packing joints · CPC title