Filter medium for air filter and method for its production

Abstract

A filter medium for an air filter, characterized in that it comprises a filter material having a glass fiber as its primary component and an alkyl ketene dimer adhered to the surface of the glass fiber; and a method for producing the filter medium which comprises a step of subjecting a dispersed slurry of a raw material fiber to a wet papermaking to form a wet paper, a step of immersing the wet paper in an aqueous dispersion or solution of the dimer or a liquid mixture of the dimer and a binder resin, or applying or spraying any of the above-mentioned liquids to the wet paper, to thereby allow the dimer to adhere onto the surface of the glass fiber, and a step of drying the resultant wet paper having the dimer adhered thereto. The filter medium exhibits a reduced amount of an out gas generated when it is used with ventilation and also exhibits high water-repellency and satisfactory strength in various applications such as air conditioning of a building and semiconductor manufacturing.

Dependencies are inferred from the claim text.