Homopolymerized epoxy-based foam-in-place material

• US 20030060522A1
• Filed: 04/10/2002
• Published: 03/27/2003
• Est. Priority Date: 09/24/2001
• Status: Active Grant

• Current Assignee: Zephyros, Inc.
• Original Assignee: L&L Products Inc.
• Inventors: Kosal, David J., Czaplicki, Michael J., Madaus, Keith
• Granted Patent: US 6,890,964 B2
• Time in Patent Office: Days
• US Class Current: 521/50
• CPC Class Codes: C08J 2203/22 Expandable microspheres, e.g. Expancel®
• CPC Class Codes: C08J 2363/00 Characterised by the use of epoxy resins; Derivatives of epoxy resins
• CPC Class Codes: C08J 9/0066 Use of inorganic compounding ingredients
• CPC Class Codes: C08J 9/32 from compositions containing microballoons, e.g. syntactic foams

Abstract

A two-component foam-in-place structural material for producing a foamed product. The first component of the system includes an epoxy-based resin preferably formulated with a physical blowing agent particulate material. The physical blowing agent core is encapsulated within a shell or skin that will change state. The second component is an acid that is capable of initiating polymerization of the resin. A reactive mixture is achieved through the combination of the first and second components wherein heat from the exothermic reaction of the epoxy component caused by the acid in turn causes the thermoplastic shell having a solvent core to soften and increase in size due to gas pressure and change in state of the shell thereby foaming the reactive mixture.

Claims

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

(a) providing a pre-mixed epoxy resin having an encapsulated solvent core, wherein the solvent core is provided in an expandable shell;

(b) providing an acid component, the acid component being phosphoric acid;

(c) combining the epoxy resin with the acid component to form an admixture, wherein;

i) the admixture includes from about 50% to about 98% by weight of the resin; and

ii) the admixture include about 5% to about 15% by weight of the acid; and

(d) applying the admixture to a member;

wherein the acid component is combined with the resin to form the admixture no more than about 60 minutes before applying the admixture to the member and wherein the admixture foams upon forming the admixture to form the foamed article.

2. A method as in claim 1 wherein the admixture is substantially free of any components other than the epoxy resin and the acid component upon application of the admixture to the member.

3. A method as in claim 1 wherein the epoxy resin includes a blowing agent.

4. A method as in claim 1 wherein foaming of the admixture is at least partially controlled by acid strength of acid component.

5. A method as in claim 1, further including the step of combining said phosphoric acid with an inert filler prior to forming the admixture.

6. A method as in claim 1, further comprising the step of combining a filler with the admixture.

7. A method as in claim 1 wherein the epoxy resin and the encapsulated solvent core are combined prior to adding said phosphoric acid.

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

(a) providing a pre-mixed epoxy resin having an encapsulated solvent core particle, wherein;

i) the epoxy resin is a bisphenol A based epoxy resin; and

ii) the solvent core is provided as a hydrocarbon encapsulated in an expandable polymer shell;

(b) providing an acid component, the acid component being orthophosporic acid; and

(c) combining the epoxy resin with the acid component to form an admixture, wherein;

i) the admixture includes from about 50% to about 98% by weight of the resin; and

ii) the admixture include about 5% to about 15% by weight of the acid; and

(d) applying the admixture to a member of an automotive vehicle, the member being selected from a frame member and a body member;

wherein the acid component is combined with the resin to form the admixture no more than about 60 minutes before applying the admixture to the member of the vehicle and wherein admixture foams upon forming the admixture to form the foamed article.

9. A method as in claim 8 wherein the admixture is substantially free of any components other than the epoxy resin and the acid component upon application of the admixture to the member.

10. A method as in claim 8 wherein the epoxy resin includes a blowing agent.

11. A method as in claim 8 wherein foaming of the admixture is at least partially controlled by acid strength of acid component.

12. A method as in claim 8, further including the step of combining said phosphoric acid with an inert filler prior to forming the admixture.

13. A method as in claim 8, further comprising the step of combining a filler with the admixture.

14. A method as in claim 8 wherein the epoxy resin and the encapsulated solvent core are combined prior to adding said phosphoric acid.

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

(a) providing a pre-mixed epoxy resin having an encapsulated solvent core particle, wherein;

i) the epoxy resin has a molecular weight from about 350 to about 600;

ii) the epoxy resin has about 1.8 to about 2.5 epoxide functional groups per molecule;

iii) the epoxy resin is a bisphenol A based epoxy resin; and

iv) the solvent core is provided as a hydrocarbon encapsulated in a polymer shell;

(b) providing an acid component, the acid component being orthophosporic acid having a molarity in a range from about 10 M to about 14.7 M; and

(c) combining the epoxy resin with the acid component to form an admixture, wherein;

i) the admixture includes from about 50% to about 98% by weight of the resin; and

ii) the admixture include about 5% to about 15% by weight of the acid; and

(d) applying the admixture to a member of an automotive vehicle, the member being selected from a frame member and a body member;

wherein the acid component is combined with the resin to form the admixture no more than about 10 minutes before applying the admixture to the member of the vehicle and wherein, upon forming the admixture, the acid component reacts with the epoxy resin to catalyze polymerization of the epoxy resin and to provide an exotherm that softens the polymer shell to expand and foam the resin thereby forming the foamed article.

16. A method as in claim 15 wherein the admixture is substantially free of any components other than the epoxy resin and the acid component upon application of the admixture to the member.

17. A method as in claim 15 wherein the epoxy resin includes a blowing agent.

18. A method as in claim 15 wherein foaming of the admixture is at least partially controlled by acid strength of acid component.

19. A method as in claim 15, further including the step of combining said phosphoric acid with an inert filler prior to forming the admixture.

20. A method as in claim 15 wherein the epoxy resin and the encapsulated solvent core are combined prior to adding said phosphoric acid.