The present invention is generally related to a high capacity, high efficiency nonwoven filtration media comprising a gradient pore structure. In particular, the filtration media can comprise thermoplastic synthetic microfibers, fibrillated fibers, staple fibers, and a binder. Furthermore, the filtration media may be produced without the use of glass fibers or microglass fibers. Consequently, the filtration media of the present invention does not cause the same issues as conventional filtration media that comprises glass fibers and/or microglass fibers. Moreover, the filtration media can be used to treat fuel, lubrication fluids, hydraulic fluids, and various other industrial gases.

The present invention is generally related to a high capacity, high efficiency nonwoven filtration media comprising a gradient pore structure. In particular, the filtration media can comprise thermoplastic synthetic microfibers, fibrillated fibers, staple fibers, and a binder. Furthermore, the filtration media may be produced without the use of glass fibers or microglass fibers. Consequently, the filtration media of the present invention does not cause the same issues as conventional filtration media that comprises glass fibers and/or microglass fibers. Moreover, the filtration media can be used to treat fuel, lubrication fluids, hydraulic fluids, and various other industrial gases.

The invention relates to a filtering material permeable to air and impermeable to oral, nasal and/or ocular human liquid aqueous excretions, comprising at least one bundle, referred to as a hydrophobic bundle, of at least two hydrophobic sheets which are superimposed and each formed by porous paper, having a gsm substance less than 30 g/m.sup.2, each hydrophobic sheet being formed by cellulose fibres, referred to as cross-linked cellulose fibres, which are connected to each other by hydrogen bonds and by covalent bonds which are formed with at least one group of cross-linking atoms, characterised in that at least some of the hydroxyls of the cross-linked cellulose fibres which are not engaged in hydrogen bonds and which are accessible to the gases form a covalent bond with an acyl group with a hydrophobic chain.

The invention relates to a filtering material permeable to air and impermeable to oral, nasal and/or ocular human liquid aqueous excretions, comprising at least one bundle, referred to as a hydrophobic bundle, of at least two hydrophobic sheets which are superimposed and each formed by porous paper, having a gsm substance less than 30 g/m.sup.2, each hydrophobic sheet being formed by cellulose fibres, referred to as cross-linked cellulose fibres, which are connected to each other by hydrogen bonds and by covalent bonds which are formed with at least one group of cross-linking atoms, characterised in that at least some of the hydroxyls of the cross-linked cellulose fibres which are not engaged in hydrogen bonds and which are accessible to the gases form a covalent bond with an acyl group with a hydrophobic chain.

An object of the present invention is to provide a chemical liquid purification method by which a chemical liquid capable of inhibiting the occurrence of short in a semiconductor substrate manufactured by a photolithography process is obtained. Another object of the present invention is to provide a chemical liquid manufacturing method and a chemical liquid. The chemical liquid purification method of the present invention includes a purification step of filtering a liquid to be purified by using a filter, in which a filter satisfying a condition 1 or a condition 2 in the following test is used as the filter. Test: 1,500 ml of a test liquid formed of the organic solvent is brought into contact with the filter for 24 hours under a condition of 23° C., and a content of particles containing at least one kind of metal selected from the group consisting of Fe, Al, Cr, Ni, and Ti in the test liquid after the contact satisfies a predetermined condition.

An object of the present invention is to provide a chemical liquid purification method by which a chemical liquid capable of inhibiting the occurrence of short in a semiconductor substrate manufactured by a photolithography process is obtained. Another object of the present invention is to provide a chemical liquid manufacturing method and a chemical liquid. The chemical liquid purification method of the present invention includes a purification step of filtering a liquid to be purified by using a filter, in which a filter satisfying a condition 1 or a condition 2 in the following test is used as the filter. Test: 1,500 ml of a test liquid formed of the organic solvent is brought into contact with the filter for 24 hours under a condition of 23° C., and a content of particles containing at least one kind of metal selected from the group consisting of Fe, Al, Cr, Ni, and Ti in the test liquid after the contact satisfies a predetermined condition.

Articles and methods involving filter media are generally provided. In certain embodiments, the filter media includes at least a first layer, a second layer, and an adhesive resin positioned between the first layer and the second layer. In some embodiments, the first layer may be a pre-filter layer or a support layer. The second layer may, for example, comprise fibers formed by a solution spinning process and/or may comprise fine fibers. In some embodiments, the adhesive resin may be present in a relatively low amount and/or may have a low glass transition temperature. The filter media as a whole may have one or more advantageous properties, including one or more of a high stiffness, a high bond strength between the first layer and the second layer, a high gamma, and/or a low increase in air resistance after being subjected to an IPA vapor discharge. The filter media may be, for example, a HEPA filter and/or an ULPA filter.

Articles and methods involving filter media are generally provided. In certain embodiments, the filter media includes at least a first layer, a second layer, and an adhesive resin positioned between the first layer and the second layer. In some embodiments, the first layer may be a pre-filter layer or a support layer. The second layer may, for example, comprise fibers formed by a solution spinning process and/or may comprise fine fibers. In some embodiments, the adhesive resin may be present in a relatively low amount and/or may have a low glass transition temperature. The filter media as a whole may have one or more advantageous properties, including one or more of a high stiffness, a high bond strength between the first layer and the second layer, a high gamma, and/or a low increase in air resistance after being subjected to an IPA vapor discharge. The filter media may be, for example, a HEPA filter and/or an ULPA filter.

A layer for a protective mask (100a, 100b, 200a) comprises at least a first sublayer (122b, 218b), wherein the first sublayer (122b, 218b) includes a first substrate and a layer of a plurality of nanoparticles (124b, 7) of a nanomaterial provided on the first substrate. The protective mask (100a, 100b, 200a) includes an outer layer (120b, 230a) which is made of an organic fibular network bonded with nanomaterials. An air filtration element (900, 1070, 1240) for attenuation of airborne contaminants includes negatively charged nanodiamonds (920, 1320). A filter (1100, 1200, 1500, 1600) for an air conditioning system (1130, 1530) or an air purifier (1230, 1630) comprises the air filtration element (900, 1070, 1240). An air treatment element (1140,1300,1540,1640) comprises nanodiamonds (920,1320) including colour centers. The protective mask (100a, 100b, 200a), the air filtration element (900, 1070, 1240), the air treatment element (1140,1300,1540,1640) and the filter (1100, 1200, 1500, 1600) overcome or at least partially ameliorate some of the deficiencies as associated with those of the prior art.

A layer for a protective mask (100a, 100b, 200a) comprises at least a first sublayer (122b, 218b), wherein the first sublayer (122b, 218b) includes a first substrate and a layer of a plurality of nanoparticles (124b, 7) of a nanomaterial provided on the first substrate. The protective mask (100a, 100b, 200a) includes an outer layer (120b, 230a) which is made of an organic fibular network bonded with nanomaterials. An air filtration element (900, 1070, 1240) for attenuation of airborne contaminants includes negatively charged nanodiamonds (920, 1320). A filter (1100, 1200, 1500, 1600) for an air conditioning system (1130, 1530) or an air purifier (1230, 1630) comprises the air filtration element (900, 1070, 1240). An air treatment element (1140,1300,1540,1640) comprises nanodiamonds (920,1320) including colour centers. The protective mask (100a, 100b, 200a), the air filtration element (900, 1070, 1240), the air treatment element (1140,1300,1540,1640) and the filter (1100, 1200, 1500, 1600) overcome or at least partially ameliorate some of the deficiencies as associated with those of the prior art.