Two-component (epoxy/amine) structural foam-in-place material

• US 6,787,579 B2
• Filed: 05/02/2001
• Issued: 09/07/2004
• Est. Priority Date: 05/02/2001
• Status: Active Grant

• Current Assignee: Zephyros, Inc.
• Original Assignee: L&L Products Inc.
• Inventors: Kosal, David J., Czaplicki, Michael J., Madaus, Keith
• Primary Examiner(s): Foelak, Morton
• Application Number:
  US09/847,252
• Publication Number:
  US 20020187305A1
• Time in Patent Office: 1,224 Days
• Field of Search: 521/54, 521/135, 521/178
• US Class Current: 521/54
• CPC Class Codes: C08J 2363/00 Characterised by the use of epoxy resins; Derivatives of epoxy resins
• CPC Class Codes: C08J 9/32 from compositions containing microballoons, e.g. syntactic foams
• CPC Class Codes: Y10T 428/24372 Particulate matter
• CPC Class Codes: Y10T 428/24612 Composite web or sheet

Abstract

The present invention relates to methods, materials, and products for forming a foamed product, comprising the steps of combining an epoxy-based component with an amine-based component. The epoxy component is cross-linked through a polymerization reaction catalyzed by the amine formulation. In this regard, a reactive mixture or exothermic reaction is created between the epoxy component and the amine component when combined. The heat generated by the exothermic reaction softens a thermoplastic shell of a blowing agent formulated within the epoxy component thereby enabling a solvent core within the thermoplastic shell of the blowing agent to expand from the heat generated by the exothermic reaction.

Claims

1. A method for producing a foamed article, comprising the steps of:

providing an epoxy component, said epoxy component comprising an epoxy resin, a blowing agent having a thermoplastic shell filled with a solvent core, and a thixotropic filler, said epoxy component being provided in a substantially liquid form;

providing an amine component, said amine component comprising an amine and a thixotropic filler, said amine component being provided in a substantially liquid form; and

combining said epoxy component in its substantially liquid form and said amine component in its substantially liquid form thereby forming a reactive mixture and allowing said thermoplastic shell filed with a solvent core to soften from amine-epoxy exotherm and then expand due to gas pressure from said solvent core without addition of external heat.

2. The method for producing a foamed article recited in claim 1, wherein said epoxy resin comprises from about 35% to about 99% by weight of said reactive mixture.

3. The method for producing a foamed article recited in claim 1, wherein said epoxy resin and said thixotropic filler are combined prior to adding said blowing agent.

4. The method for producing a foamed article recited in claim 3, further including the step of combining said blowing agent with an inert filler prior to combining said blowing agent with said epoxy resin and said thixotropic filler.

5. The method for producing a foamed article recited in claim 1, wherein said reactive mixture further includes an additive selected from the group consisting of carbon black, ceramic microspheres, polymer particles, rubber particles, ceramic particles, inert mineral particles and combinations thereof.

6. The method of producing a foamed article recited in claim 1, wherein said reactive mixture is adapted for application upon portions of an automotive vehicle selected from the group consisting of a rail member, a frame member, a door assembly, a rocker, and a frame cross member.

7. The method of producing a foamed article recited in claim 1, wherein said reactive mixture is adapted for application upon portions of an automotive vehicle selected from the group consisting of a vehicle window frame, a vehicle deck lid, a lift gate, a vehicle pillar assembly, and a vehicle hatch.

8. The method of producing a foamed article recited in claim 1, wherein said reactive mixture is adapted for application upon portions of an automotive vehicle selected from the group consisting of a vehicle roof system, a roof bow, a roof rail, and a roof header.

9. The method of producing a foamed article recited in claim 1, wherein said reactive mixture is adapted for application upon portions of an automotive vehicle selected from the group consisting of a fender assembly, a bumper, and a front end structure.

21. The method for producing a foamed article recited in claim 1, wherein said thixotropic filler or said epoxy component and said thixotropic filler of said amine component are selected from silica, a calcium carbonate or an aramid.

22. The method for producing a foamed article recited in claim 1, wherein said thixotropic filler of said epoxy component and said thixotropic filler of said amine component are an aramid are aramid pulp.

23. The method for producing a foamed article recited in claim 1, wherein said thixotropic filler of said epoxy component and said thixotropic filler of said amine component are a calcium carbonate selected from a precipitated calcium carbonate or a coated calcium carbonate.

24. The method for producing a foamed article recited in claim 1, wherein said thixotropic filler of said epoxy component and said thixotropic filler of said amine component are a silica selected from fumed silica or pyrogenic silica.

10. A method for producing a foamed article, comprising the steps of:

providing an epoxy component, said epoxy component comprising an epoxy resin, a thixotropic filler and a blowing agent having a thermoplastic shell filled with a solvent core, the thixotropic filler being an aramid pulp, said epoxy component being provided in a substantially liquid form;

providing an amino component, said amine component comprising a cycloaliphatic amine curing agent and a thixotropic filler, the thixotropic filler including aramid pulp, said amine component being provided in a substantially liquid form; and

combining said epoxy component in its substantially liquid form and said amine component in its substantially liquid form thereby forming a reactive mixture and allowing said thermoplastic shell filled with a solvent core to soften from amine-epoxy exotherm and then expand due to gas pressure from said solvent core without addition of external heat.

11. The method for producing a foamed article recited in claim 10, wherein said epoxy resin comprises from about 35% to about 99% by weight of said reactive mixture.

12. The method for producing a foamed article recited in claim 10, wherein said epoxy resin and said thixotropic filler are combined prior to adding said blowing agent.

13. The method for producing a foamed article recited in claim 10, further including the step of combining said blowing agent with an inert filler prior to combining said blowing agent with said epoxy resin and said thixotropic filler.

14. The method for producing a foamed article recited in claim 10, wherein said reactive mixture further includes an additive selected form the group consisting of carbon black, ceramic microspheres, polymer particles, rubber particles, ceramic particles, inert mineral particles and combinations thereof.

15. The method for producing a foamed article recited in claim 10, further comprising the steps of placing the reactive mixture in the cavity of an automotive vehicle.

16. The method of producing a foamed article recited in claim 10, wherein said reactive mixture is adapted for application upon portions of an automotive vehicle selected from the group consisting of a rail member, a frame member, a door assembly, a rocker, and a frame cross member.

17. The method of producing a foamed article recited in claim 10, wherein said reactive mixture is adapted for application upon portions of an automotive vehicle selected from the group consisting of a vehicle window frame, a vehicle deck lid, a lift gate, a vehicle pillar assembly, and a vehicle hatch.

18. The method of producing a foamed article recited in claim 10, wherein said reactive mixture is adapted for application upon portions of an automotive vehicle selected from the group consisting of a vehicle roof system, a roof bow, a roof rail, and a roof header.

19. The method of producing a foamed article recited in claim 10, wherein said reactive mixture is adapted for application upon portions of an automotive vehicle selected from the group consisting of a fender assembly, a bumper, and a front end structure.

20. A method for producing a foamed article, comprising the steps of:

providing a substantially liquid epoxy component that includes;

i) an epoxy resin;

ii) a blowing agent having a thermoplastic shell filled with a solvent core; and

iii) a thixotropic filler wherein the filler includes aramid pulp;

providing a substantially liquid amine component that includes;

i) a cycloaliphatic amine curing agent;

ii) an amine that is less reactive than the cycloallphatic curing agent; and

iii) a thixotropic filler wherein the filler includes aramid pulp;

combining and dispensing said substantially liquid epoxy component and said substantially liquid amine component at around room temperature to form a reactive mixture wherein;

i) the epoxy component and the amine component are formed as separate liquids prior to forming the reactive mixture;

ii) the epoxy component and the amine component react together exothermically to produce heat; and

iii) the heat causes the thermoplastic shell filled with a solvent core to soften and expand due to gas pressure from said solvent core without addition of external heat;

providing the reactive mixture within an automotive body cavity contemporaneously with the formation of the mixture or shortly thereafter, and allowing the reactive mixture to cure to form said foamed article wherein said foamed article is capable of substantial plastic deformation after curing without substantial loss of strength modulus and wherein said foamed article has a glass transition temperature greater than 200°

F. after such plastic deformation.