In recent years, there have been concerns about not only epidemic of seasonal influenza but also human pandemic of highly-pathogenic avian influenza caused by the mutation of avian influenza viruses.
Further, there has also been a concern about a new outbreak of the highly lethal SARS virus. Under the circumstances, the fears of highly-pathogenic RNA viruses are increasing. In order to address such problems, for example, Patent Document 1 discloses an article useful for inactivating viruses upon contact. The article comprises a fabric substrate bearing a coating of immobilized polymer molecules that provides the fabric substrate with nonleachable antiviral activity, wherein the polymer molecules comprise a hydrophilic polymer having pendant antiviral groups comprising a plurality of pendant cationic groups comprising quaternary ammonium groups and a plurality of pendant hydrocarbon groups.
Patent Document 2 discloses an antiviral agent comprising, as an active ingredient, a water-insoluble aromatic hydroxy compound having a phenolic hydroxyl group at least one position. Patent Document 3 discloses an antiviral mask comprising a filter material having at least one layer containing citric acid as hydroxy acid having both a hydroxyl group (—OH) and a carboxyl group (—COOH). Patent Document 4 discloses an antiviral agent for fiber treatment comprising poly-oxyethylene(dimethylimino)ethylene(dimethylimino)ethyl ene dichloride.
However, the quaternary ammonium groups contained in the article disclosed in Patent Document 1 are cationic groups, and therefore a surfactant or the like needs to coexist to allow the polymer to be contained in a fiber such as rayon, which causes a problem that antiviral activity is lowered.
The water-insoluble aromatic hydroxy compound having a phenolic hydroxyl group disclosed in Patent Document 2 has a problem that white fibers are colored when treated therewith or its antiviral activity is not sufficient.
Citric acid used in Patent Document 3 is sensitive to repeated washing, and therefore has a problem that its antiviral activity is lowered by washing. Poly-oxyethylene(dimethylimino)ethylene(dimethylimino)ethyl ene dichloride used in Patent Document 4 has a problem that it is not suitable for use in daily clothes due to the dermal irritancy of a halogen.
Patent Document 5 discloses that antibacterial activity is imparted to fibers by graft polymerization of an acidic group-containing vinyl-based monomer onto the fibers. However, as described in paragraphs (0005) and (0006) in Patent Document 4, various antibacterial compounds have been heretofore developed and many of them have been used for fiber products, but it cannot be said that such antibacterial compounds inhibit viral infection. For this reason, there has been demand for development of viral infection inhibitors excellent in fiber processability.