Abstract: A process for manufacturing a porous body, includes preparing a dispersion liquid having a dispersion medium with cellulose-based nanofibers that have an average fiber diameter from 1 to 100 nm and dispersed therein, attaching the dispersion liquid to a porous support having a plurality of pores that connect with one another, removing the dispersion liquid attached to a surface of the porous support excluding an inside of pores of the porous support, and subsequently drying the porous support including the dispersion liquid in the pores of the porous support to remove the dispersion medium.

Abstract: A process for manufacturing a porous body, includes preparing a dispersion liquid having a dispersion medium with cellulose-based nanofibers that have an average fiber diameter from 1 to 100 nm and dispersed therein, attaching the dispersion liquid to a porous support having a plurality of pores that connect with one another, removing the dispersion liquid attached to a surface of the porous support excluding an inside of pores of the porous support, and subsequently drying the porous support including the dispersion liquid in the pores of the porous support to remove the dispersion medium.

Abstract: A method for manufacturing a filter medium for an air filter having improved particle collection performance using cellulose nanofibers. The method for manufacturing a filter medium for an air filter comprises: causing a mixed solution containing cellulose nanofibers and a dispersion medium to adhere to an air-permeable support; and subsequently freeze-drying the resulting product, in which a number average fiber diameter of the cellulose nanofibers is 1 to 50 nm, the dispersion medium is a mixed dispersion medium of water and a water-soluble organic solvent, and a solid content concentration of the cellulose nanofibers in the mixed solution is 0.001 to 0.150% by mass.

Abstract: A method for producing a wet-laid nonwoven fabric for a semipermeable membrane supporting body, the method comprising: performing papermaking according to a wet papermaking method by using a fiber slurry containing a synthetic fiber as a main constituent fiber; drying the fiber slurry; subsequently subjecting the dried sheet to hot press processing two times by using a heat calender apparatus, wherein the hot press process temperature in the second treatments is adjusted to be higher by 10° C. or more than the hot press processing temperature in the first treatment, while treating the dried sheet by using a hard nip heat calender apparatus equipped with a combination of a metal roll and a metal roll for at least one time of the hot press processing; and thereby obtaining a wet-laid nonwoven fabric for a semipermeable membrane supporting body.

Abstract: A method for manufacturing a filter medium for an air filter having improved particle collection performance using cellulose nanofibers. The method for manufacturing a filter medium for an air filter comprises: causing a mixed solution containing cellulose nanofibers and a dispersion medium to adhere to an air-permeable support; and subsequently freeze-drying the resulting product, in which a number average fiber diameter of the cellulose nanofibers is 1 to 50 nm, the dispersion medium is a mixed dispersion medium of water and a water-soluble organic solvent, and a solid content concentration of the cellulose nanofibers in the mixed solution is 0.001 to 0.150% by mass.

Abstract: Provided is a nonwoven fabric for semipermeable membrane support, in which adhesiveness of a semipermeable membrane to a support is satisfactory, the thickness uniformity of the semipermeable membrane is satisfactory, and permeation-through of a coating liquid does not occur.

Abstract: A filter media for an air filter having a PF value higher than ever, and an air filter provided with the same. The filter media for an air filter is composed of wet-laid nonwoven fabric containing a glass fiber having an average fiber diameter of less than 1 and a binder fiber, and wherein the wet-laid nonwoven fabric contains a fluorine resin and a surfactant, and does not contain a resin binder or contains a binder resin in an amount of 50% by mass or less based on the fluorine resin.

Abstract: A method for producing a wet-laid nonwoven fabric for a semipermeable membrane supporting body, the method comprising: performing papermaking according to a wet papermaking method by using a fiber slurry containing a synthetic fiber as a main constituent fiber; drying the fiber slurry; subsequently subjecting the dried sheet to hot press processing two times by using a heat calender apparatus, wherein the hot press process temperature in the second treatments is adjusted to be higher by 10° C. or more than the hot press processing temperature in the first treatment, while treating the dried sheet by using a hard nip heat calender apparatus equipped with a combination of a metal roll and a metal roll for at least one time of the hot press processing; and thereby obtaining a wet-laid nonwoven fabric for a semipermeable membrane supporting body.

Abstract: A porous body that contains cellulose nanofibers having very thin fiber diameters and high hydrophilicity, and has a large specific surface area, and to provide a method of producing the porous body simply with low cost. A method of producing a porous cellulose comprises a process of lyophilizing a mixed liquid containing cellulose nanofibers and a dispersion medium, wherein the dispersion medium is a mixed dispersion medium of water and an organic solvent dissolving in water, a concentration of the organic solvent in the mixed dispersion medium is 2 to 40 mass %, and a solid content concentration of the cellulose nanofibers in the mixed liquid is 0.001 to 5 mass %.

Abstract: A filter media for an air filter having a PF value higher than ever, and an air filter provided with the same. The filter media for an air filter is composed of wet-laid nonwoven fabric containing a glass fiber having an average fiber diameter of less than 1 ?m, and a binder fiber, and wherein the wet-laid nonwoven fabric contains a fluorine resin and a surfactant, and does not contain a resin binder or contains a binder resin in an amount of 50% by mass or less based on the fluorine resin.

Abstract: Provided is a nonwoven fabric for semipermeable membrane support, in which adhesiveness of a semipermeable membrane to a support is satisfactory, the thickness uniformity of the semipermeable membrane is satisfactory, and permeation-through of a coating liquid does not occur.

Abstract: A porous body that contains cellulose nanofibers having very thin fiber diameters and high hydrophilicity, and has a large specific surface area, and to provide a method of producing the porous body simply with low cost. A method of producing a porous cellulose comprises a process of lyophilizing a mixed liquid containing cellulose nanofibers and a dispersion medium, wherein the dispersion medium is a mixed dispersion medium of water and an organic solvent dissolving in water, a concentration of the organic solvent in the mixed dispersion medium is 2 to 40 mass %, and a solid content concentration of the cellulose nanofibers in the mixed liquid is 0.001 to 5 mass %.

Abstract: The object of the present invention is to provide a porous body having fluid permeance, which contains cellulose-based nanofibers having an extremely thin fiber diameter and high hydrophilicity, and to manufacture a porous body at low cost. The porous body according to the present invention is a porous body in which nanofibers are entangled to form net-like structural bodies in pores of a porous support having many pores that are connecting with one another, wherein the nanofibers are cellulose-based nanofibers, and have a number average fiber diameter of from 1 to 100 nm.

Abstract: The present invention addresses the problem of providing a nonwoven fabric for semipermeable membrane supporting body, which gives fine MD curl when a semipermeable membrane coating liquid is coated on the supporting body (nonwoven fabric) and cured, and a method for producing the nonwoven fabric.

Abstract: Provided is a non-woven fabric for semipermeable membrane support, in which adhesiveness of a semipermeable membrane to a support is satisfactory, the thickness uniformity of the semipermeable membrane is satisfactory, and permeation-through of a coating liquid does not occur. Disclosed is a non-woven fabric for semipermeable membrane support containing organic synthetic fibers as a primary component, wherein a semipermeable membrane is to be supported by one surface of the non-woven fabric, wherein the coated surface to be coated with the semipermeable membrane and the non-coated surface that is opposite to the coated surface of the non-woven fabric both have a Bekk smoothness of 5 seconds or more, and the non-woven fabric has an internal bond strength in the sheet transverse direction in the range from 0.4 to 0.8 N·m.

Abstract: A uniform semipermeable membrane supporting body which does not cause any defect in the semipermeable membrane coating layer when a semipermeable membrane coating liquid is applied, and is free of low density defects. The wet-laid nonwoven fabric for a semipermeable membrane supporting body according to the present disclosure contains a synthetic fiber as a main constituent fiber, has been subjected to hot press processing, has a pressure loss at a face velocity of 5.3 cm/second of from 50 Pa to 3000 Pa and a sheet density of 0.