A rigid nylon porous material sheet is produced by the adhesive bonding of kinked nylon fibers having lengths of 1 to 5 inches. These fibers are cut from melt spun nylon or harvested from clean carpet fibers by shearing. The adhesive used is glycol, which attacks nylon at 180 C. forming a gel on the surface of the kinked fibers, but does not attack the nylon fibers when the kinked fiber assembly is cooled to 150 C. to precipitate ultrafine nylon within the gel. The fiber assembly is heated to 160 C. to bond the nylon fibers. It is then washed in hot water to remove unused glycol. The other adhesive is polyurethane, which is applied to the kinked fibers using coupling agents of aqueous resorcinol and vinyl pyrrolidone.

The invention addresses the problem of providing a filter fabric for a bag filter, which has excellent collection performance and low pressure drop and is resistant to a decrease in dust collection performance due to abrasion or cracking, and also a method for producing the same. Means for resolution is a filter fabric for a bag filter in which a nonwoven fabric A including short fibers a having a single-fiber fineness of 0.3 to 0.9 dtex, a base fabric, and a nonwoven fabric B including short fibers b having a single-fiber fineness of 0.3 to 4.0 dtex are laminated in this order.

The invention addresses the problem of providing a filter fabric for a bag filter, which has excellent collection performance and low pressure drop and is resistant to a decrease in dust collection performance due to abrasion or cracking, and also a method for producing the same. Means for resolution is a filter fabric for a bag filter in which a nonwoven fabric A including short fibers a having a single-fiber fineness of 0.3 to 0.9 dtex, a base fabric, and a nonwoven fabric B including short fibers b having a single-fiber fineness of 0.3 to 4.0 dtex are laminated in this order.

Disclosed are technical fibers and yarns made with partially aromatic polyamides and non-halogenated flame retardant additives. Fabrics made from such fibers and yarns demonstrate superior flame retardancy over traditional flame retardant nylon 6,6 fabrics. Further, the disclosed fibers and yarns, when blended with other flame retardant fibers, do not demonstrate the dangerous scaffolding effect common with flame retardant nylon 6,6 blended fabrics.

Disclosed are technical fibers and yarns made with partially aromatic polyamides and non-halogenated flame retardant additives. Fabrics made from such fibers and yarns demonstrate superior flame retardancy over traditional flame retardant nylon 6,6 fabrics. Further, the disclosed fibers and yarns, when blended with other flame retardant fibers, do not demonstrate the dangerous scaffolding effect common with flame retardant nylon 6,6 blended fabrics.

A problem addressed by the present invention is to provide a resin out of which a heat-resistant non-woven fabric having a fine fiber diameter can be made by an electrospinning method. A main object of the present invention is to provide a resin, including a structure(s) represented by at least one selected from the group consisting of the following general formulae (1) to (3), wherein an end of the main-chain of the resin has at least one selected from alkyl groups having 10 or more carbon atoms and fluoroalkyl groups having 4 or more carbon atoms;

##STR00001##

(wherein, in the general formula (1), X independently represents a single bond or NR.sup.3; R.sup.1 and R.sup.2 independently represent a C.sub.4-C.sub.30 bivalent organic group; R.sup.3 represents a hydrogen atom or a C.sub.1-C.sub.10 monovalent organic group; in the general formula (2), R.sup.4 represents a C.sub.4-C.sub.30 bivalent organic group; R.sup.5 represents a C.sub.4-C.sub.30 tetravalent organic group; in the general formula (3), R.sup.6 represents a C.sub.4-C.sub.30 bivalent organic group; R.sup.7 represents a C.sub.4-C.sub.30 trivalent organic group; l, m, and n are each an integer of 0 or greater with the proviso that l+m+n=10 or greater; and wherein the structures represented by the general formulae (1) to (3) do not necessarily need to be consecutively present.)

A problem addressed by the present invention is to provide a resin out of which a heat-resistant non-woven fabric having a fine fiber diameter can be made by an electrospinning method. A main object of the present invention is to provide a resin, including a structure(s) represented by at least one selected from the group consisting of the following general formulae (1) to (3), wherein an end of the main-chain of the resin has at least one selected from alkyl groups having 10 or more carbon atoms and fluoroalkyl groups having 4 or more carbon atoms;

##STR00001##

(wherein, in the general formula (1), X independently represents a single bond or NR.sup.3; R.sup.1 and R.sup.2 independently represent a C.sub.4-C.sub.30 bivalent organic group; R.sup.3 represents a hydrogen atom or a C.sub.1-C.sub.10 monovalent organic group; in the general formula (2), R.sup.4 represents a C.sub.4-C.sub.30 bivalent organic group; R.sup.5 represents a C.sub.4-C.sub.30 tetravalent organic group; in the general formula (3), R.sup.6 represents a C.sub.4-C.sub.30 bivalent organic group; R.sup.7 represents a C.sub.4-C.sub.30 trivalent organic group; l, m, and n are each an integer of 0 or greater with the proviso that l+m+n=10 or greater; and wherein the structures represented by the general formulae (1) to (3) do not necessarily need to be consecutively present.)

A reinforced paper includes a nonwoven fibrous mat impregnated with a polyetherimide composition. The nonwoven fibrous mat includes a reinforcing fiber, a high strength toughening fiber, or a combination thereof. The polyetherimide composition includes a polyetherimide having repeating units as defined herein. A method of making a reinforced paper is also disclosed. The method includes contacting at least a portion of a nonwoven fibrous mat with a composition to form a pre-preg, and heating under conditions effective to provide the reinforced paper. Articles including the reinforced paper are also described.

Provided is a polymer nanofiber sheet having high delamination resistance, a high mechanical strength, and a high specific surface area. Specifically, provided is a polymer nanofiber sheet, including polymer nanofibers, the polymer nanofibers being laminated and three-dimensionally entangled with each other, in which: at least part of the polymer nanofibers are crosslinked at a crosslinked part having crosslinking portions and a non-crosslinking portion; and the crosslinked part contains a low-molecular weight epoxy compound having a molecular weight of from 100 to 3,000.

Provided is a polymer nanofiber sheet having high delamination resistance, a high mechanical strength, and a high specific surface area. Specifically, provided is a polymer nanofiber sheet, including polymer nanofibers, the polymer nanofibers being laminated and three-dimensionally entangled with each other, in which: at least part of the polymer nanofibers are crosslinked at a crosslinked part having crosslinking portions and a non-crosslinking portion; and the crosslinked part contains a low-molecular weight epoxy compound having a molecular weight of from 100 to 3,000.