Structural adhesive compositions

Patent metadata

Field	Value
Publication number	US-12031064-B2
Application number	US-202217697727-A
Country	US
Kind code	B2
Filing date	Mar 17, 2022
Priority date	Nov 19, 2010
Publication date	Jul 9, 2024
Grant date	Jul 9, 2024

Abstract

Disclosed herein are compositions including (a) a first component comprising (1) an epoxy-adduct that is the reaction product of reactants comprising a first epoxy compound, a polyol, and an anhydride and/or a diacid and (2) a second epoxy compound; (b) rubber particles having a core/shell structure and/or graphenic carbon particles; and (c) a second component that chemically reacts with the first component at ambient or slightly thermal conditions. Also disclosed herein are compositions including (a) an epoxy-capped flexibilizer; (b) a heat-activated latent curing agent; and optionally (c) rubber particles having a core/shell structure and/or graphenic carbon particles; (d) an epoxy/CTBN adduct; and/or (e) an epoxy/dimer acid adduct. The heat-activated latent curing agent may include at least one reaction product of reactants including an epoxy compound and an amine and/or an alkaloid.

First claim

We claim:

1. A one-component composition comprising:
(a) an epoxy-capped flexibilizer comprising a reaction product of reactants comprising (i) a first epoxy compound, (ii) a polyol, and (iii) a diacid;
(b) a heat-activated latent curing agent comprising (x) a reaction product of reactants comprising (i) a second epoxy compound and (ii) an amine, an alkaloid, or combinations thereof, and (y) dicyandiamide having a D98 of 6 μm;
(c) an optional epoxy/CTBN adduct;
(d) an epoxy/dimer acid adduct;
(e) rubber particles having a core/shell structure;
(f) optional graphenic carbon particles; and
an epoxy compound or an epoxy resin not incorporated into or reacted as a part of any of the components (a)-(f) and/or an epoxy carrier resin incorporated into the component (e).

2. The one-component composition of claim 1 , which comprises at least one of:
2% by weight to 40% by weight, based on total weight of the composition, of the epoxy-capped flexibilizer (a);
3% by weight to 25% by weight, based on total weight of the composition, of the heat-activated latent curing agent (b);
a positive amount of up to 75% by weight, based on total weight of the composition, of the rubber particles having a core/shell structure (e); and
1% by weight to 15% by weight, based on total weight of the composition, of the epoxy/dimer acid adduct (d).

3. The one-component composition of claim 1 , wherein the first epoxy compound reactant (i) of the epoxy-capped flexibilizer (a) comprises Bisphenol A diglycidyl ether, phenyl diglycidyl ether, or combinations thereof.

4. The one-component composition of claim 1 , wherein the polyol reactant (ii) of the epoxy-capped flexibilizer (a) has a hydroxy equivalent weight of 30 to 1000.

5. The one-component composition of claim 1 , wherein the polyol reactant (ii) of the epoxy-capped flexibilizer (a) comprises ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, polyether diols of any of the foregoing, polyester diols, urethane diols or combinations thereof.

6. The one-component composition of claim 5 , wherein the polyester diol is synthesized by ring opening polymerization of caprolactone.

7. The one-component composition of claim 5 , wherein the urethane diol is synthesized by reaction of a cyclic carbonate with a diamine.

8. The one-component composition of claim 1 , wherein the polyol reactant (ii) of the epoxy-capped flexibilizer (a) comprises polytetrahydrofuran, a diol derived from caprolactone or combinations thereof.

9. The one-component composition of claim 1 , wherein the reactants of the epoxy-capped flexibilizer (a) further comprise an anhydride.

10. The one-component composition of claim 1 , wherein (x) is a reaction product of reactants comprising (i) a second epoxy compound and (ii) an alkaloid, which are provided in a molar ratio of (i) to (ii) of 1:1 to 3:1.

11. The one-component composition of claim 1 , wherein (x) is a reaction product of reactants comprising (i) a second epoxy compound and (ii) an amine, which are provided in a molar ratio of (i) to (ii) of 1:2 to 8:9.

12. The one-component composition of claim 1 , wherein (x) is a reaction product of reactants comprising (i) a second epoxy compound and (ii) an amine or an alkaloid.

13. The one-component composition of claim 12 , wherein the alkaloid comprises an imidazole.

14. The one-component composition of claim 1 , wherein the heat-activated latent curing agent (b) further comprises 3,4-dichlorophenyl-N,N-dimethyl urea.

15. The one-component composition of claim 1 , wherein at least one of the epoxy/CTBN adduct (c) and the graphenic carbon particles (f) is present in the composition.

16. The one-component composition of claim 15 , wherein the epoxy/CTBN adduct (c) is formed from CTBN having a functionality of 1.6 to 2.4.

17. The one-component composition of claim 1 , wherein the epoxy/CTBN adduct (c) is present in an amount of 1% by weight to 20% by weight, based on total weight of the composition.

18. The one-component composition of claim 1 , further comprising 1,10-phenanthroline as a chelating agent.

19. The one-component composition of claim 1 , wherein the composition is formulated to cure at a temperature of 120° C. to 140° C. within 20 minutes or less.

20. The one-component composition of claim 1 , wherein the composition is formulated to cure following exposure to thermal conditions or actinic radiation.

21. A method of treating a substrate, comprising:
applying the composition of claim 1 to a surface of the substrate.

22. The method of claim 21 , further comprising heating the composition at a temperature of 120° C. to 140° C.

23. The method of claim 21 , further comprising exposing the composition to thermal conditions or actinic radiation for 20 minutes or less.

24. An article comprising:
a coating formed on a surface of a substrate from the composition of claim 1 .

25. The article of claim 24 , further comprising a second substrate, wherein the composition is positioned between the surface and the second substrate.

26. The article of claim 25 , wherein the coating has a measured lap shear strength of at least 15 MPa when tested at room temperature.

27. An automotive component comprising the article of claim 24 .

28. A wind turbine comprising the article of claim 24 .

Assignees

• Ppg Ind Ohio Inc

Inventors

• Desai Umesh C
• Chao Tien-Chieh
• Nakajima Masayuki
• Ragunathan Kaliappa G

Classifications

• C09J5/00

  Adhesive processes in general; Adhesive processes not provided for elsewhere, e.g. relating to primers · CPC title

• C08K3/04

  Carbon · CPC title

• C08G59/184

  with amines · CPC title

• C08G59/066

  with chain extension or advancing agents · CPC title

• C08G59/182

  using pre-adducts of epoxy compounds with curing agents · CPC title