Heat-curable, thermally expandable moulded park

• US 6,573,309 B1
• Filed: 08/31/2001
• Issued: 06/03/2003
• Est. Priority Date: 03/03/1999
• Status: Expired due to Term

• Current Assignee: Henkel AG & Co KGaA
• Original Assignee: Henkel-Teroson GmbH (Henkel AG & Co KGaA)
• Inventors: Reitenbach, Dirk, Muenz, Xaver
• Primary Examiner(s): Foelak, Morton
• Application Number:
  US09/914,555
• Time in Patent Office: 641 Days
• Field of Search: 521/135, 521/178
• US Class Current: 521/135
• CPC Class Codes: C08G 59/186 with acids
• CPC Class Codes: C08G 59/4021 Ureas; Thioureas; Guanidines; Dicyandiamides
• CPC Class Codes: C08J 2363/00 Characterised by the use of epoxy resins; Derivatives of epoxy resins
• CPC Class Codes: C08J 2463/00 Characterised by the use of epoxy resins; Derivatives of epoxy resins
• CPC Class Codes: C08J 9/0061 characterized by the use of several polymeric components
• CPC Class Codes: C08J 9/32 from compositions containing microballoons, e.g. syntactic foams

Abstract

Foamable compositions which exhibit reduced surface tack and better handling characteristics are obtained through the use of specific combinations of epoxy resins. One or more solid epoxy resins are utilized together with liquid and/or semi-solid epoxy resins. The compositions, which preferably contain hollow glass microspheres, are capable of providing foams which are useful in the manufacture of reinforced structural members.

Claims

1. A thermosetting, thermally-expandable molded body comprising:

(a) at least one solid reactive resin selected from the group consisting of (i) solid polyglycidyl ethers of polyphenols, polyalcohols and diamines, (ii) solid polyglycidyl esters of polycarboxylic acids, and mixtures thereof,

(b) at least one liquid reactive resin selected from the group consisting of (i) liquid polyglycidyl ethers of polyphenols, polyalcohols and diamines, (ii) liquid polyglycidyl esters of polycarboxylic acids, and mixtures thereof,

(c) at least one reactive resin conferring flexibility selected from the group consisting of rubber-modified epoxy resins, polyurethane-modified epoxy resins, adducts of amino-terminated polyoxyalkylenes and polyepoxides, adducts of polymeric fatty acids and epichlorohydrin, glycidol, or diglycidyl ethers of bisphenol A, adducts of polyether polyols with epoxy resins, polymercaptan-modified epoxy resins, polysulfide-modified epoxy resins, and mixtures thereof,

(d) at least one additive selected from the group consisting of latent hardeners and accelerators, and

(e) at least one expanding agent.

2. A molded body as claimed in claim 1 wherein said molded body is not tacky at room temperature.

3. A molded body as claimed in claim 1 wherein the solid reactive resin (a) and the liquid reactive resin (b) are polyglycidyl ethers of bisphenol A.

4. A molded body as claimed in claim 1 wherein the solid reactive resin (a) has a melting point of from 45 to 90°

C.

5. A molded body as claimed in claim 1 wherein the solid reactive resin (a) has an epoxy equivalent weight greater than 400.

6. A molded body as claimed in claim 1 wherein at least one reactive resin conferring flexibility is an adduct of at least one polymeric fatty acid and at least one diglycidyl ether of bisphenol A.

7. A molded body as claimed in claim 1 wherein there is used as the latent hardener dicyandiamide in an amount of up to 5 wt. %, based on the total composition.

8. A molded body as claimed in claim 1 additionally comprising one or more fillers, at least a part of the fillers being lightweight fillers selected from the group consisting of hollow glass spheres, flue ash, hollow plastic spheres, hollow ceramic spheres and organic lightweight fillers of natural origin.

9. A molded body as claimed in claim 1 wherein the expanding agent (e) is expandable hollow microspheres.

10. A molded body as claimed in claim 1 additionally comprising fibers selected from the group consisting of aramide fibers, carbon fibers, glass fibers, polyamide fibers, polyethylene fibers and polyester fibers.

11. A molded body comprising:

(a) one or more solid epoxy resins selected from the group consisting of (i) solid polyglycidyl ethers of polyphenols, polyalcohols, and diamines, (ii) solid polyglycidyl esters of polycarboxylic acids, and mixtures thereof from 25 to 50 wt. %

(b) one or more liquid epoxy resins selected from the group consisting of (i) liquid polyglycidyl ethers of polyphenols, polyalcohols, and diamines, (ii) liquid polyglycidyl esters of polycarboxylic acids, and mixtures thereof from 10 to 50 wt. %

(c) one or more epoxy resins conferring flexibility selected from the group consisting of rubber-modified epoxy resins, polyurethane-modified epoxy resins, adducts of amino-terminated polyoxyalkylenes and polyepoxides, adducts of polymeric fatty acids and epichlorohydrin, glycidol, or diglycidyl ethers of bisphenol A, adducts of polyether polyols with epoxy resins, polymercaptan-modified epoxy resins, polysulfide-modified epoxy resins, and mixtures thereof from 1 to 25 wt. %

12. A method of rigidifying and/or reinforcing a structure having a hollow space, said method comprising:

(i) molding a mixture comprised of

(a) at least one solid epoxy resin selected from the group consisting of solid polyglycidyl ethers of polyphenols, polyalcohols and diamines, solid polyglycidyl esters of polycarboxylic acids, and mixtures thereof;

(b) at least one liquid epoxy resin selected from the group consisting of liquid polyglycidyl ethers of polyphenols, polyalcohols and diamines, liquid polyglycidyl esters of polycarboxylic acids, and mixtures thereof;

(c) at least one reactive resin conferring flexibility selected from the group consisting of rubber-modified epoxy resins, polyurethane-modified epoxy resins, adducts of polymeric fatty acids and epichlorohydrin, glycidol, or diglycidyl ethers of bisphenol A, adducts of polyether polyols with epoxy resins, polymercaptan-modified epoxy resins, polysulfide-modified epoxy resins and mixtures thereof;

(d) at least one additive selected from the group consisting of hardeners and accelerators; and

(e) at least one expanding agent;

at a temperature of 60°

C. to 110°

C. to form a molded body;

(ii) cooling the molded body;

(iii) introducing said molded body to said hollow space of said structure;

(iv) heating said molded body to a temperature of from 110°

C. to 200°

C., whereupon the volume of the molded body expands and the molded body hardens to a thermoset.

13. A method as claimed in claim 12 wherein molding step (i) is carried out by injection molding.

14. A method as claimed in claim 12 wherein molding step (i) is carried out using a procedure selected from the group consisting of extruding, casting, compression molding, and stamping.

15. A method as claimed in claim 12 wherein said molded body expands in volume by from 50 to 100% during step (iv).

16. A method as claimed in claim 12 wherein the temperature in step (i) is from 70°

C. to 90°

C.

17. A method as claimed in claim 12 wherein the temperature in step (iv) is from 130°

C. to 180°

C.

18. A method as claimed in claim 12 wherein the molded body is softened by heating when introducing the molded body to the hollow space.

19. A method of rigidifying and/or reinforcing a substrate, said method comprising:

(i) molding a mixture comprised of

(a) at least one solid epoxy resin selected from the group consisting of solid polyglycidyl ethers of polyphenols, polyalcohols and diamines, solid polyglycidyl esters of polycarboxlic acids, and mixtures thereof;

(b) at least one liquid epoxy resin selected from the group consisting of liquid polyglycidyl ethers of polyphenols, polyalcohols and diamines, liquid polyglycidyl esters of polycarboxylic acids, and mixtures thereof;

(c) at least one reactive resin conferring flexibility selected from the group consisting of rubber-modified epoxy resins, polyurethane-modified epoxy resins, adducts of amino-terminated polyoxyalkylenes and polyepoxides, adducts of polymeric fatty acids and epichlorohydrin, glycidol, or diglycidyl ethers of bisphenol A, adducts of polyether polyols with epoxy resins, polymercaptan-modified epoxy resins, polysulfide-modified epoxy resins and mixtures thereof;

(d) at least one additive selected from the group consisting of hardeners and accelerators; and

(e) at least one expanding agent;

form a molded body;

(ii) cooling the molded body;

(iii) applying said molded body to said substrate; and

(iv) heating said molded body to a temperature of from 110°

C. to 200 C., whereupon the volume of the molded body expands and the molded body hardens to a thermoset.

20. A method as claimed in claim 19 wherein molding step (i) is carried out by injection molding.

21. A method as claimed in claim 19 wherein molding step (i) is carried out using a procedure selected from the group consisting of extruding, casting, compression molding and stamping.

22. A method as claimed in claim 19 wherein said molded body expands in volume by from 50 to 100% during step (iv).

23. A method as claimed in claim 19 wherein the temperature in step (i) is from 70°

C. to 90°

C.

24. A method as claimed in claim 19 wherein the temperature in step (iv) is from 130°

C. to 180°

C.

25. A method as claimed in claim 19 wherein the molded body is softened by heating when applying the molded body to the substrate.

26. A thermosetting, thermally-expandable molded body which is dimensionally stable and not tacky at room temperature comprising:

(a) at least one liquid epoxy resin which is a liquid polyglycidyl ether of a polyphenol and which has an epoxy equivalent weight of 150 to 480;

(b) at least one solid epoxy resin which is a solid polyglycidyl ether of a polyphenol and which has a melting point of from 45°

C. to 90°

C.;

(c) at least one reactive resin conferring flexibility selected from the group consisting of rubber-modified epoxy resins, polyurethane-modified epoxy resins, adducts of amino-terminated polyoxyalkylenes and polyepoxides, adducts of polymeric fatty acids and epichlorohydrin, glycidol, or diglycidyl ethers of bisphenol A, adducts of polyether polyols with epoxy resins, polysulfide-modified epoxy resins, polymercaptan-modified epoxy resins and mixtures thereof;

(d) at least one latent hardener or accelerator selected from the group consisting of guanidines, substituted guanidines, substituted ureas, melamine resins, guanamine derivatives, cyclic tertiary amines, aromatic amines, imidazole derivatives, and mixtures thereof;

(e) at least one expanding agent selected from the group consisting of azo compounds, hydrazides, and expandable hollow plastic microspheres; and

(f) at least one light weight filler selected from the group consisting of hollow glass microspheres, flue ash, hollow plastic spheres, hollow ceramic spheres, organic lightweight fillers of natural origin, and mixtures thereof.

27. A molded body as claimed in claim 26 additionally comprising fibers selected from the group consisting of aramide fibers, carbon fibers, glass fibers, polyamide fibers, polyethylene fibers, polyester fibers and mixtures thereof.

28. A thermosetting, thermally-expandable molded body which is dimensionally stable and not tacky at room temperature comprising:

(a) at leat one liquid epoxy resin obtained by reaction of bisphenol A and epichlorohydrin and having an epoxy equivalent weight of from 182 to 350;

(b) at least one solid epoxy resin obtained by reaction of bisphenol A and epichlorohydrin and having a melting point from 50°

C. to 80°

C. and an epoxy equivalent weight of from 450 to 900;

(c) at least one reactive resin conferring flexibility selected from the reaction products of polymeric fatty acids with diglycidyl ethers of bisphenol A;

(d) at least one latent hardener or accelerator selected from substituted guanidines;

(e) expandable plastic microspheres; and

(f) hollow glass microspheres.

29. A molded body as claimed in claim 28 additionally comprising polyaramide fibers selected from the group consisting of polyaramide fibers, polyester fibers, and mixtures thereof.

30. A method of rigidifying and/or reinforcing a metal component, said method comprising applying a molded body which is non-tacky and dimensionally stable at room temperature and comprised of

(a) at least one solid reactive resin selected from the group consisting of (i) solid polyglycidyl ethers of polyphenols, polyalcohols, and diamines, (ii) solid polyglycidyl esters of polycarboxylic acids, and mixtures thereof;

(b) at least one liquid reactive resin selected from the group consisting of (i) liquid polyglycidyl ethers of polyphenols, polyalcohols, and diamines, (ii) liquid polyglycidyl esters of polycarboxylic acids, and mixtures thereof;

(c) at least one reactive resin conferring flexibility selected from the group consisting of rubber-modified epoxy resins, polyurethane-modified epoxy resins, adducts of amino-terminated polyoxyalkylenes and polyepoxides, adducts of polymeric fatty acids and epichlorohydrin, glycidol, or diglycidyl ethers of bisphenol A, adducts of polyether polyols with epoxy resins, polymercaptan-modified epoxy resins, polysulfide-modified epoxy resins, and mixtures thereof;

(d) at least one additive selected from the group consisting of hardeners and accelerators; and

(e) at least one expanding agent,

to said metal component and heating said molded body to a temperature effective to expand said molded body in volume and to harden said molded body to a thermoset.

31. A method claimed in claim 30 wherein said molded body is additionally comprised of fibers.