Abstract: Some of ?-cyanoacrylate adhesive does not achieve practical bond (adhesion) strength and any objective materials do not have adhesion with the same. The inventor provides a primer which is not harmful against human body and shows when applied sufficient adhesion strength even on those materials hard to have adhesion. A primer for cyanoacrylate adhesive characterized by comprising as an effective content amphoteric compounds containing in molecules the following substances a and b: a: carboxyl group or sulfonic acid group, and b: amines.

Abstract: Some of ?-cyanoacrylate adhesive does not achieve practical bond (adhesion) strength and any objective materils do not have adhesion with the same. The inventor provides a primer which is not harmful against human body and shows when applied sufficient adhesion strength even on those materials hard to have adhesion. A primer for cyanoacrylate adhesive characterized by comprising as an effective content amphoteric compounds containing in molecules the following substances a and b: a: carboxyl group or sulfonic acid group, and b: amines.

Abstract: A keypad is disclosed, comprising a structure in which a protective layer made of a 2-cyanoacrylate cured product is provided in a protuberant state on a display pattern formed on a touch base of a silicone rubber-made keypad preferably via a primer coated layer. A process for producing the keypad being also disclosed wherein the protective layer having a high adhesion, hardly generating cracks even by keying operations in a number of times and hardly causing yellowing with a lapse of time can be provided in the display pattern of the keypad made of silicon rubber.