Structural adhesives

Patent metadata

Field	Value
Publication number	US-11248145-B2
Application number	US-93677709-A
Country	US
Kind code	B2
Filing date	Apr 7, 2009
Priority date	Apr 9, 2008
Publication date	Feb 15, 2022
Grant date	Feb 15, 2022

Abstract

An adhesive formulation comprising i) an adduct of an epoxy resin and an elastomer, ii) a phenoxy resin; iii) a core/shell polymer; iv) a curing agent which provides a structural adhesive with improved low temperature impact strength particularly useful for bonding metal especially in the automotive industry.

First claim

The invention claimed is:

1. An adhesive formulation comprising:
i) an adduct of an epoxy resin and an elastomer, wherein the adhesive formulation contains from about 7% to about 20% by weight of the adduct based on the adhesive formulation;
ii) a phenoxy epoxy hybrid resin supplied as a solution formed by dissolving a phenoxy resin in a liquid epoxy resin to form a pre-formed dissolution product;
iii) a core/shell polymer, wherein the adhesive formulation contains from 5% to 30% by weight of the core/shell polymer;
iv) a curing agent; and
v) one or more additional epoxy resins;
wherein the adhesive formulation includes between about 55% by weight and about 70% by weight total epoxy resin, wherein the total epoxy resin is the liquid epoxy resin of the phenoxy epoxy hybrid resin and the one or more additional epoxy resins;
wherein the adhesive formulation is a liquid or a paste at room temperature;
wherein the adhesive formulation contains between 3% to 10% by weight of the phenoxy resin so that the adhesive formulation is pumpable;
wherein the adhesive formulation functions over a temperature range of about −40° C. to about 90° C.; and
wherein the adhesive formulation has a strength when cured in the wedge impact test at −40° C. of greater than 20 N/mm.

2. The adhesive formulation according to claim 1 , wherein the formulation contains from about 7% to about 15% by weight of the adduct based on the adhesive formulation.

3. The adhesive formulation according to claim 1 , wherein the adduct includes about 1:5 to 5:1 parts of epoxy to elastomer.

4. The adhesive formulation according to claim 1 , wherein the elastomer in the adduct is selected from a group consisting of: natural rubber, styrene-butadiene rubber, polyisoprene, polyisobutylene, polybutadiene, isoprene-butadiene copolymer, neoprene, nitrile rubber, butyl rubber, polysulfide elastomer, acrylic elastomer, acrylonitrile elastomers, silicone rubber, polysiloxanes, polyester rubber, diisocyanate-linked condensation elastomer, ethylene-propylene diene rubbers, chlorosulphonated polyethylene, fluorinated hydrocarbons, and any combination thereof.

5. The adhesive formulation according to claim 4 , wherein the adduct of the epoxy resin and the elastomer is derived from a butadiene acrylonitrile rubber.

6. The adhesive formulation according to claim 1 , wherein the phenoxy resin is of the formula

where n is from 30 to 100.

7. The adhesive formulation according to claim 1 , wherein the formulation provides added strength to metal welds including weld flanges.

8. The adhesive formulation according to claim 1 , wherein the core/shell polymer has a ductile core and a rigid shell which is compatible with the other components of the formulation.

9. The adhesive formulation according to claim 1 , in which the core/shell polymer includes materials selected from a group consisting of: styrenics, acrylonitriles, acrylates, acetates, polyamides, polyethylenes, and any combination thereof.

10. The adhesive formulation according to claim 1 , wherein the core/shell polymer is a graft copolymer in which styrene, acrylonitrile, or methyl methacrylate, are grafted onto a core polymer made from polymers of soft or elastomeric compounds.

11. The adhesive formulation according to claim 10 , wherein the core polymer includes other copolymerizable containing compounds, selected from styrene, vinyl acetate, methyl methacrylate, butadiene, and isoprene.

12. The adhesive formulation according to claim 10 , wherein the core polymer includes a cross linking monomer having two or more nonconjugated double bonds.

13. The adhesive formulation according to claim 10 , wherein a shell portion of the core/shell polymer is polymerized from alkyl acrylates and/or methacrylates.

14. The adhesive formulation according to claim 1 , wherein the curing agent is selected from aliphatic or aromatic amines or their respective adducts, amidoamines, polyamides, cycloaliphatic amines, anhydrides, polycarboxylic polyesters, isocyanates, phenol-based resins, and mixtures thereof.

15. The adhesive formulation according to claim 14 , in which the curing agent is selected from modified and unmodified polyamines or polyamides.

16. The adhesive formulation according to claim 1 , wherein the formulation contains between 7% and 15% by weight of the liquid epoxy resin of the phenoxy epoxy hybrid resin.

17. The adhesive formulation according to claim 1 , wherein the formulation contains one or more liquid poly sulfides.

18. The adhesive formulation according to claim 1 , comprising from about 1% to about 10% by weight of the curing agent.

19. The adhesive formulation according to claim 18 , comprising about 0.2% to about 3% by weight of a cure accelerator, about 0.1% to about 50% by weight mineral filler, and about 0.1% to about 3.0% by weight clay and/or silica.

20. The adhesive formulation according to claim 15 , wherein the curing agent is selected from one or more of triethylenetetramine, diethylenetriamine tetraethylenepentamine, cyanoguanidine, and dicyandiamides.

21. An adhesive formulation comprising:
i) an adduct of an epoxy resin and an elastomer, wherein the formulation contains from about 7% to about 15% by weight of the adduct based on the adhesive formulation, and wherein the adduct includes about 1:5 to 5:1 parts of epoxy to elastomer;
ii) a phenoxy epoxy hybrid resin supplied as a solution formed by dissolving a phenoxy resin in a liquid epoxy resin to form a pre-formed dissolution product;
iii) a core/shell polymer, wherein the adhesive formulation contains from 5% to 30% by weight of the core/shell polymer;
iv) a curing agent; and
v) one or more additional epoxy resins;
wherein the adhesive formulation includes between about 55% by weight and about 70% by weight total epoxy resin, wherein the total epoxy resin is the liquid epoxy resin of the phenoxy epoxy hybrid resin and the one or more additional epoxy resins;
wherein the adhesive formulation is a liquid or a paste at room temperature;
wherein the adhesive formulation contains between 3% to 10% by weight of the phenoxy resin so that the adhesive formulation is pumpable;
wherein the adhesive formulation functions over a temperature range of about −40° C. to about 90° C.; and
wherein the adhesive formulation has a strength when cured in the wedge impact test at −40° C. of greater than 20 N/mm.

Assignees

• Czaplicki Michael
• Zephyros Inc

Inventors

• Czaplicki Michael

Classifications

• C08G2650/56

  Polyhydroxyethers, e.g. phenoxy resins · CPC title

• C09J2400/163

  in the substrate · CPC title

• C08L2205/025

  containing two or more polymers of the same hierarchy C08L, and differing only in parameters such as density, comonomer content, molecular weight, structure · CPC title

• C09J5/06 Primary

  involving heating of the applied adhesive · CPC title

• C09J11/08

  Macromolecular additives · CPC title