A method of preparing a vinyl collagen microsphere polyamide fiber composite material includes the following steps: step 1: modifying a collagen with methacrylic anhydride to obtain a vinyl collagen, then emulsifying and cross-linking the vinyl collagen to obtain vinyl collagen microspheres; step 2: treating a polyamide fiber substrate with formaldehyde to obtain a hydroxylated polyamide fiber substrate, treating the hydroxylated polyamide fiber with (3-mercaptopropyl)trimethoxysilane (MPS) to obtain a sulfhydrylated polyamide fiber substrate; and step 3: modifying the sulfhydrylated polyamide fiber substrate with the vinyl collagen microspheres to obtain the vinyl collagen microsphere polyamide fiber composite material.

According to one embodiment, a fiber sheet includes a plurality of fibers. The plurality of fibers are in a closely-adhered state. All of the following (1) to (3) are satisfied, where F1 is a tensile strength in a first direction, and F2 is a tensile strength in a second direction orthogonal to the first direction: (1) F2>F1; (2) F1 is 1 MPa or more; and (3) F2/F1 is 2 or more.

A human hair fiber treatment agent for treating human hair fibers separated from the human head and artificially fixed at one part of the longitudinal direction, wherein the human hair fiber treatment agent comprises the following components (A) to (C) in the formulation thereof, and the content of the component (A) is 1% by mass or more: (A): formaldehyde or a hydrate thereof; (B): a melamine derivative represented by the formula (1) wherein R.sup.1 to R.sup.3 each represent a hydrogen atom, a hydroxymethylamino group, a hydroxy group, a halogen atom, a phenyl group, a linear or branched alkyl group or alkenyl group having 1 or more and 6 or less carbon atoms, or a linear or branched alkoxy group or alkenyloxy group having 1 or more and 6 or less carbon atoms; and (C): water.

##STR00001##

A human hair fiber treatment agent for treating human hair fibers separated from the human head and artificially fixed at one part of the longitudinal direction, wherein the human hair fiber treatment agent comprises the following components (A) to (C) in the formulation thereof, and the content of the component (A) is 1% by mass or more: (A): formaldehyde or a hydrate thereof; (B): a melamine derivative represented by the formula (1) wherein R.sup.1 to R.sup.3 each represent a hydrogen atom, a hydroxymethylamino group, a hydroxy group, a halogen atom, a phenyl group, a linear or branched alkyl group or alkenyl group having 1 or more and 6 or less carbon atoms, or a linear or branched alkoxy group or alkenyloxy group having 1 or more and 6 or less carbon atoms; and (C): water.

##STR00001##

A method of preparing a vinyl collagen microsphere polyamide fiber composite material includes the following steps: step 1: modifying a collagen with methacrylic anhydride to obtain a vinyl collagen, then emulsifying and cross-linking the vinyl collagen to obtain vinyl collagen microspheres; step 2: treating a polyamide fiber substrate with formaldehyde to obtain a hydroxylated polyamide fiber substrate, treating the hydroxylated polyamide fiber with (3-mercaptopropyl)trimethoxysilane (MPS) to obtain a sulfhydrylated polyamide fiber substrate; and step 3: modifying the sulfhydrylated polyamide fiber substrate with the vinyl collagen microspheres to obtain the vinyl collagen microsphere polyamide fiber composite material.

A method of preparing a vinyl collagen microsphere polyamide fiber composite material includes the following steps: step 1: modifying a collagen with methacrylic anhydride to obtain a vinyl collagen, then emulsifying and cross-linking the vinyl collagen to obtain vinyl collagen microspheres; step 2: treating a polyamide fiber substrate with formaldehyde to obtain a hydroxylated polyamide fiber substrate, treating the hydroxylated polyamide fiber with (3-mercaptopropyl)trimethoxysilane (MPS) to obtain a sulfhydrylated polyamide fiber substrate; and step 3: modifying the sulfhydrylated polyamide fiber substrate with the vinyl collagen microspheres to obtain the vinyl collagen microsphere polyamide fiber composite material.

The present disclosure provides a method for producing a cell-culturing polyvinyl alcohol-based nanofiber structure, the method comprising: electrospinning an electrospun solution to form a nanofiber mat, wherein the electrospun solution contains polyvinyl alcohol (PVA), polyacrylic acid (PA) and glutaraldehyde (GA); crosslinking the nanofiber mat via a hydrochloric acid (HCl) vapor treatment; and treating the crosslinked nanofiber mat with dimethylformamide (DMF) solvent to crystallize the nanofiber mat.

The present disclosure provides a method for producing a cell-culturing polyvinyl alcohol-based nanofiber structure, the method comprising: electrospinning an electrospun solution to form a nanofiber mat, wherein the electrospun solution contains polyvinyl alcohol (PVA), polyacrylic acid (PA) and glutaraldehyde (GA); crosslinking the nanofiber mat via a hydrochloric acid (HCl) vapor treatment; and treating the crosslinked nanofiber mat with dimethylformamide (DMF) solvent to crystallize the nanofiber mat.

The present invention relates to a method for manufacturing a cord for a power transmission belt, including a first treatment step of treating an untreated yarn of a cord for a power transmission belt with a first treatment agent containing: a rubber composition (A) containing a condensate (A1) of a resorcin and formaldehyde, a rubber component (A2) containing a carboxy-modified latex, and a curing agent (A3) containing a polycarbodiimide resin having a plurality of carbodiimide groups; and a hydrophilic solvent (B).

The present invention relates to a method for manufacturing a cord for a power transmission belt, including a first treatment step of treating an untreated yarn of a cord for a power transmission belt with a first treatment agent containing: a rubber composition (A) containing a condensate (A1) of a resorcin and formaldehyde, a rubber component (A2) containing a carboxy-modified latex, and a curing agent (A3) containing a polycarbodiimide resin having a plurality of carbodiimide groups; and a hydrophilic solvent (B).