Process for producing sponge rubber stamp having open cell

Abstract

A process for producing a sponge rubber stamp having open cell of the present invention comprises the steps of superposing an unvulcanized rubber sheet (A) containing a water-easily soluble powder upon an unvulcanized rubber sheet (B) containing an acid-soluble powder, heating/pressing them to form an integral laminate, treating the integral laminate with water to make the layer (A) porous, sculpturing the surface of the layer (B) of the integral laminate by a laser beam to form a stamp surface thereon, and then treating the integral laminate with an aqueous acid solution. No microcracks occur in the stamp at the formation of the stamp surface, and the stamp surface precision and the durability of the obtained stamp are excellent. In addition, the formation of a prototype and a matrix of the stamp as well as the treatment of the stamp can be simplified.

Dependencies are inferred from the claim text.