Patent ID: 7365034

Claim:
A latent carbon dioxide gas generating material comprising: (A) layer 1 containing fiber and a binder, having a basis weight of from about 25 gsm to about 100 gsm and having inner and outer surfaces, (B) layer 2 containing a carbon dioxide gas generating composition, having a basis weight of from about 5 gsm to about 300 gsm and having upper and lower surfaces, wherein layer 2 contains a carbon dioxide gas generating composition comprising a weak base and a weak acid, and (C) layer 3 containing fiber and a binder, having a basis weight of from about 25 gsm to about 100 gsm and having inner and outer surfaces, where the inner surface of layer 1 is in contact with the upper surface of layer 2 and the inner surface of layer 3 is in contact with the lower surface of layer 2 .