Method of forming a toughened adhesive material

1. A method of forming and applying an adhesive material comprising the steps of:

forming a mixture including:

i) locating in a container an epoxy resin in an amount of from about 15% to about 40% by weight of the mixture, at least 50% of which is provided as a liquid epoxy, the liquid epoxy having a viscosity of at least 8000 cps at 23° C.;

ii) locating into the container a plurality of pellets of an impact modifier comprising a methacrylate-butadiene-styrene core/shell polymer in an amount of less than about 30% by weight of the mixture;

iii) locating into the container an epoxidized polysulfide flexibilizer in an amount of at least 5% to about 45% by weight for maintaining impact strength at low temperatures while minimizing the reduction of glass transition temperature; and

iv) locating into the container a curing agent;

v) locating into the container a clay filler,

wherein, in the step of forming the mixture, the core/shell polymer and at least a portion of the epoxy resin are mixed in solid form prior to the introduction of any liquid components;

locating the adhesive material upon a first surface; and

activating the adhesive material to bond the adhesive material to a second surface;

forming a discrete secondary phase within the adhesive material upon activation, whereby a portion of the adhesive material including the core/shell polymer separates itself from the rest of the adhesive material.

2. A method as in claim 1 , wherein the first surface and second surface are part of a component of an automotive vehicle.

3. A method as in claim 1 , wherein the impact modifier forms a discrete phase in the adhesive material upon activation of the adhesive material, the activation including curing.

4. A method as in claim 3 , wherein at least a portion of the impact modifier has a T g of less than −50° C.

5. A method as in claim 3 , wherein the epoxidized polysulfide flexibilizer is an epoxy or amine modified polymer.

6. A method as in claim 1 , wherein the adhesive material further includes about 1% to about 20% by weight one or more copolymers having a thermoplastic polyether.

7. A method as in claim 6 , wherein the thermoplastic polyether is a phenoxy resin having a molecular weight of at least 50,000.

8. The method of claim 1 , wherein the mixture comprises:

i) about 15% to about 25% by weight epoxy resin;

ii) about 1% to about 20% by weight a copolymer having a thermoplastic polyether;

iii) at least about 13% by weight core/shell polymer;

iv) at least 5% by weight epoxidized polysulfide flexibilizer.

9. A method as in claim 8 wherein, the impact modifier forms a discrete phase in the adhesive material upon activation of the adhesive material, the activation including curing.

10. A method as in claim 9 , wherein at least a portion of the impact modifier has a Tg of less than −50° C.

11. A method as in claim 8 , wherein the adhesive material further includes about 1% to about 20% by weight a phenoxy resin having a molecular weight of at least 50,000.

12. The method of claim 1 including disposing the adhesive material as a part upon a release material;

removing the adhesive material from the release material and locating the adhesive material upon or adjacent the first surface of an automotive vehicle; and

activating, by heating the adhesive material above 120° C., so as to foam and thermoset the adhesive material such that the adhesive material bonds to the first surface and the second surface of the automotive vehicle.

13. A method as in claim 8 , wherein:

i) the epoxy resin includes a liquid portion and has a viscosity from about 8,000 to about 22,000 cps, an epoxy equivalent weight of about 150 to about 220 g/eq, or both;

ii) the copolymer is a phenoxy resin with a molecular weight of at least 50,000;

iii) the adhesive material further includes an epoxy/rubber adduct;

iv) the adhesive material further includes a curing agent accelerator having a modified diphenyl bis urea, an imidazole, blocked amine, or any combination thereof.

14. A method as in claim 13 , wherein the adhesive material includes an exterior surface that is substantially tacky and a handling layer that is generally free of tack, and wherein the release material is disposed along at least a portion of the exterior surface.