Abstract: It is intended to provide an air purification filter which has a high dry tensile strength, a high wet tensile strength in association with a high water resistance and a high water repellency and exhibits a bactericidal effect due to a gas phase reaction in a gas phase. Namely, an air purification filter having a high dry tensile strength, a high wet tensile strength (a high water resistance) and a high water repellency as well as a bactericidal effect which is obtained by blending a filter fiber having a functional group with a mixture of a modification enzyme which has an ionic polarity opposite to the ionic polarity of the whole filter fiber as described above and a bactericidal effect with an ionic synthetic resin binder having the opposite ionic polarity similar to the modification enzyme.

Abstract: It is intended to provide an air purification filter which has a high dry tensile strength, a high wet tensile strength in association with a high water resistance and a high water repellency and exhibits a bactericidal effect due to a gas phase reaction in a gas phase. Namely, an air purification filter having a high dry tensile strength, a high wet tensile strength (a high water resistance) and a high water repellency as well as a bactericidal effect which is obtained by blending a filter fiber having a functional group with a mixture of a modification enzyme which has an ionic polarity opposite to the ionic polarity of the whole filter fiber as described above and a bactericidal effect with an ionic synthetic resin binder having the opposite ionic polarity similar to the modification enzyme.

Abstract: An air purifying filter includes a modified enzyme immobilized on a surface of a carrier. The modified enzyme has been modified with a bonding agent that improves bonding. The surface of the carrier has not been rendered to be water repellant prior to immobilizing the modified enzyme on the surface of the carrier. The bonding agent improves bonding of the modified enzyme to the carrier.

Abstract: An air purifying filter includes a modified enzyme immobilized on a surface of a carrier. The modified enzyme has been modified with a bonding agent that improves bonding. The surface of the carrier has not been rendered to be water repellant prior to immobilizing the modified enzyme on the surface of the carrier. The bonding agent improves bonding of the modified enzyme to the carrier.

Abstract: An air purifying filter having an enzyme immobilized on the surface of a carrier is capable of direct killing or otherwise control of air-borne microorganisms which have been difficult to control by means of the conventional air purifying filters; and the filter is also capable of removing the retained microorganisms by killing or otherwise controlling them.

Abstract: A catalyst for the hydrodesulfurization of hydrocarbons is disclosed. The catalyst comprises at least one metal selected from the metals of the Group VIB of the Periodic Table, the Group VIII of the Periodic Table and the Group VA of the Periodic Table, or oxides, sulfide or salts thereof, or a mixture thereof or a combined material thereof, and at least one rare earth metal compound supported on a refractory carrier. The catalyst according to the present invention has markedly higher desulfurization activities and a markedly longer catalyst life than the conventional catalysts, and hydrocarbons treated with the catalyst according to the present invention show little deterioration in hue and excellent hue stability for a long period of time.