Abstract: A metal catalyst carrier body includes layers of first and second metal sheets defining passages through which exhaust gases flow. The first metal sheet is corrugated and engaged with the second metal sheet in each of upstream and downstream regions at numeral contact points. In intermediate region between the upstream and downstream regions, the first metal sheet is out of engagement with the second metal sheet.

Abstract: A new phthalide derivative useful as a colorless chromogenic material has the following formula: ##STR1## wherein R.sub.1, R.sub.2, R.sub.3, R.sub.4, R.sub.5 and R.sub.6 have the same meaning as defined hereinbefore.

Abstract: A process for preparing microcapsules for pressure sensitive manifold paper characterized by emulsifying in a hydrophilic liquid a hydrophobic liquid containing an aromatic isocyanate represented by the formula ##STR1## wherein n is an integer of 1 to 10, an aliphatic isocyanate and an electron donating organic chromogenic material, and forming a polymer at the interface to cover hydrophobic liquid droplets with the polymer.

Abstract: The residual formaldehyde existing in the aqueous dispersion of microcapsules each having a capsule wall of an aldehyde polycondensation resin formed by polycondensation of formaldehyde with an amine in the presence of an acid catalyst is removed by adjusting the aqueous dispersion to an alkaline state, adding to the aqueous dispersion at least one reaction catalyst which is a member selected from the group consisting of metal hydroxides, phosphates, calcium salts and magnesium salts, and then heating and agitating the aqueous dispersion to cause a reaction to remove residual formaldehyde therefrom.