The mixture preferably contains a blowing agent.

The adhesive preferably comprises a foaming agent.

The invention uses no additional blowing agent.

A preferred blowing agent is unmodified or modified azodicarbonamide.

The foam is made in the presence of a blowing agent and catalyst.

A blowing agent is added to the polymer where the decomposition products of the blowing agent or the decomposition products of the reaction products from the blowing agent are chemically reactive with the epoxy groups or their reaction products.

In addition, the present invention is a method for preparing a blowing agent composition and a foamable blowing agent-resin mixture.

Preferably, the pore-forming agent has a particle size of 20-500 νm.

The blowing agent has 20 weight percent or more of a first blowing agent selected from the group consisting of carbon dioxide and ethane.

Low density polymeric beads made by polymerizing monomeric building blocks into large crosslinked polymer molecules in porous, spherical bead form by droplet or suspension polymerization in the presence of a porogen.

More preferably, the proportion of the pore-forming agent is 7-40% (w/w).

Advantageously, the foam of the invention can be produced using only CO2 as a blowing agent.

The 'second material' comprises a porogen and the 'first material' comprises a matrix polymer.

Therefore, a higher concentration of blowing agent can advantageously be produced in the layer (17).

The formulation may further contain a pore-forming agent, a filler, a lubricant, or a glidant.