US-12624152-B2 - Curable compositions

Abstract

The present invention is directed to a curable composition including: an isocyanate-functional prepolymer; an epoxy-containing component present in an amount of at least 10 percent by weight of the composition; and a latent curing agent having an ability to react with at least one of the isocyanate-functional prepolymer and the epoxy-containing component upon exposure to an external energy source. The present invention is also directed to methods of making the compositions, methods of coating a substrate, methods of adhering substrates and coated substrates.

Inventors

• Joseph P. Kriley
• Marvin M. Pollum, Jr.
• Masayuki Nakajima
• David J. Fortman

Assignees

• PPG INDUSTRIES OHIO, INC.

Dates

Publication Date

20260512

Application Date

20200722

Claims (18)

1. 1 . A curable composition comprising: an isocyanate-functional prepolymer comprising a reaction product of reactants comprising a polyol and an isocyanate having an isocyanate equivalent weight of 200 g/eq to 2,000 g/eq and present in an amount of 20 percent by weight to 86 percent by weight; an epoxy-containing component comprising Bisphenol A, Bisphenol F, and/or an epoxy novolac, the epoxy-containing component present in an amount of 10 percent by weight to 75 percent by weight; a latent curing agent comprising an amine hydrogen in an amount of at least 0.5:1 to 3:1 based on a ratio of molar equivalents of amine hydrogens to total molar equivalents of isocyanate functional groups plus epoxide functional groups and having an ability to react with at least one of the isocyanate-functional prepolymer and the epoxy-containing component upon exposure to an external energy source; an elastomeric dispersion comprising elastomeric particles in an amount of 10% by weight to 35% by weight based on total weight of the elastomeric dispersion, wherein the elastomeric particles have a core-shell structure; and optionally an epoxy carrier resin incorporated into the elastomeric particles; wherein the amount by weight is based on total weight of the composition.
2. 2 . The curable composition of claim 1 , wherein the epoxy-containing component is present in an amount of 15 percent to 75 percent by weight of the curable composition.
3. 3 . The curable composition of claim 1 , wherein the latent curing agent comprises a guanidine functional group.
4. 4 . The curable composition of claim 1 , wherein the curable composition further comprises an encapsulated accelerator.
5. 5 . The curable composition of claim 1 , wherein the polyol comprises a polyether polyol.
6. 6 . The curable composition of claim 1 , wherein the curable composition, in an at least partially cured state, has a tensile strength greater than 20 MPa and an elongation at break greater than 20 percent.
7. 7 . The curable composition of claim 1 , wherein the elastomeric particles have an average particle size of 20 nm to 400 nm.
8. 8 . A substrate comprising a surface at least partially coated with a layer formed from the curable composition of claim 1 .
9. 9 . The substrate of claim 8 , wherein the substrate is an automotive component.
10. 10 . The substrate of claim 8 , wherein the substrate is an aerospace component.
11. 11 . A substrate at least partially embedded in the curable composition of claim 1 .
12. 12 . The substrate of claim 11 , wherein the substrate comprises a fibrous material, a sheet or a mesh.
13. 13 . The substrate of claim 12 , wherein the fibrous material, the sheet or the mesh comprises at least one of carbon fibers, glass fibers, and nylon.
14. 14 . An article of protective clothing comprising the curable composition of claim 1 .
15. 15 . An article comprising a first substrate, a second substrate and the curable composition of claim 1 positioned between the first substrate and the second substrate in an at least partially cured state as an adhesive to adhere the first substrate to the second substrate.
16. 16 . The article of claim 15 , wherein each of the first substrate and the second substrate are automotive components.
17. 17 . The article of claim 15 , wherein each of the first substrate and the second substrate are aerospace components.
18. 18 . A method of treating a substrate comprising: contacting at least a portion of a substrate with the curable composition of claim 1 ; and exposing the curable composition to an external energy source.

Description

GOVERNMENT CONTRACT This invention was made with Government support under Government Contract 13-02-0046 awarded by awarded by TARDEC (Tank and Automotive Research, Development and Engineering Center (US Army)). The United States Government has certain rights in this invention. FIELD OF THE INVENTION The present invention relates to curable compositions and to adhesives, sealants, coatings and composites. BACKGROUND OF THE INVENTION Curable compositions are utilized in a wide variety of applications such as to treat a variety of substrates, bond together two or more substrate materials, and fabricate composite substrates. The present invention is directed toward one-component curable compositions that are easy to apply for use in coating, sealing, bonding together substrate materials or forming composites. SUMMARY OF THE INVENTION Disclosed herein is a curable composition comprising: an isocyanate-functional prepolymer; an epoxy-containing component present in an amount of at least 10 percent by weight of the composition; and a latent curing agent having an ability to react with at least one of the isocyanate-functional prepolymer and the epoxy-containing component upon exposure to an external energy source. Also disclosed herein is a substrate comprising a surface at least partially coated with a layer formed from a curable composition comprising: an isocyanate-functional prepolymer; an epoxy-containing component present in an amount of at least 10 percent by weight of the composition; and a latent curing agent having an ability to react with at least one of the isocyanate-functional prepolymer and the epoxy-containing component upon exposure to an external energy source. Also disclosed is a substrate at least partially embedded in a curable composition comprising: an isocyanate-functional prepolymer; an epoxy-containing component present in an amount of at least 10 percent by weight of the composition; and a latent curing agent having an ability to react with at least one of the isocyanate-functional prepolymer and the epoxy-containing component upon exposure to an external energy source. Also disclosed is an article of protective clothing comprising a curable composition comprising: an isocyanate-functional prepolymer; an epoxy-containing component present in an amount of at least 10 percent by weight of the composition; and a latent curing agent having an ability to react with at least one of the isocyanate-functional prepolymer and the epoxy-containing component upon exposure to an external energy source. Also disclosed is an article comprising a first substrate, a second substrate and a curable composition comprising: an isocyanate-functional prepolymer; an epoxy-containing component present in an amount of at least 10 percent by weight of the composition; and a latent curing agent having an ability to react with at least one of the isocyanate-functional prepolymer and the epoxy-containing component upon exposure to an external energy source, wherein the curable composition is positioned between the first substrate and the second substrate in an at least partially cured state as an adhesive to adhere the first substrate to the second substrate. Also disclosed is a method of treating a substrate comprising: contacting at least a portion of a substrate with a curable composition comprising: an isocyanate-functional prepolymer; an epoxy-containing component present in an amount of at least 10 percent by weight of the composition; and a latent curing agent having an ability to react with at least one of the isocyanate-functional prepolymer and the epoxy-containing component upon exposure to an external energy source; and exposing the curable composition to an external energy source. Further disclosed herein is a curable composition comprising: an isocyanate-functional prepolymer; an epoxy-containing component present in an amount of at least 10 percent by weight of the composition; and a curing agent, wherein the curable composition has a first uncured state when the curing agent is a solid and will transition from the first uncured state to a second at least partially cured state when the curing agent changes phase from a solid to a liquid or dissolves into the curable composition. Further disclosed herein is a substrate comprising at least one surface at least partially coated with a layer formed from a curable composition comprising: an isocyanate-functional prepolymer; an epoxy-containing component present in an amount of at least 10 percent by weight of the composition; and a curing agent, wherein the curable composition has a first uncured state when the curing agent is a solid and will transition from the first uncured state to a second at least partially cured state when the curing agent changes phase from a solid to a liquid or dissolves into the curable composition. Further disclosed is a substrate at least partially embedded in a curable composition comprising: an isocyanate-functional prepolym