Abstract: It is an object of the present invention to provide an ultrafine cellulose fiber-containing sheet that is excellent in terms of weather resistance. The present invention relates to a sheet comprising cellulose fibers having a fiber width of 1000 nm or less, wherein the cellulose fibers have anionic functional groups, and the YI increase percentage calculated according to the following equation is 1500% or less. YI increase percentage (%)=(yellowness of the sheet after heating?yellowness of the sheet before heating)/yellowness of the sheet before heating×100, wherein the yellowness of the sheet after heating is a yellowness measured in accordance with JIS K 7373, after the sheet is subjected to hot pressing at 180° C. at 0.5 MPa for 1 minute, whereas the yellowness of the sheet before heating is a yellowness measured in accordance with JIS K 7373, before the sheet is subjected to the hot pressing.

Abstract: The purpose of the present invention is to provide a composite sheet in which the dimension stability when it is tensed is high and the appearance deterioration and the yellowness change are suppressed. The present invention relates to a sheet comprising; cellulose fibers having a fiber width of 1000 nm or less and having a phosphoric acid group or a phosphoric acid group-derived substituent; and a polyvinyl alcohol-based resin, wherein the sheet has a tensile elastic modulus of 3.4 GPa or more.

Abstract: It is an object of the present invention is to provide a sheet containing ultrafine cellulose fibers, which is excellent in transparency and water resistance. The present invention relates to a sheet including cellulose fibers having a fiber width of 1000 nm or less, and polyamine polyamide epihalohydrin, wherein the haze of the sheet is 6% or less.

Abstract: The purpose of the present invention is to provide a composite sheet in which the dimension stability when it is tensed is high and the appearance deterioration and the yellowness change are suppressed. The present invention relates to a sheet comprising; cellulose fibers having a fiber width of 1000 nm or less and having a phosphoric acid group or a phosphoric acid group-derived substituent; and a polyvinyl alcohol-based resin, wherein the sheet has a tensile elastic modulus of 3.4 GPa or more.

Abstract: The present invention is intended to provide an ultrafine cellulose fiber-containing wet sheet, which is easily handled upon the use thereof and is excellent in terms of adhesiveness to the skin. The present invention relates to a sheet comprising cellulose fibers having a fiber width of 1000 nm or less and water, wherein the sheet is gelatinous, the cellulose fibers have ionic substituents, the water content percentage is 70% by mass or more with respect to the total mass of the sheet, and the tensile strength is 0.08 MPa or more.

Abstract: It is an object of the present invention to provide a composition comprising cellulose fibers having a fiber width of 1000 nm or less, the properties of which are maintained even after long-term storage.

Abstract: It is an object of the present invention to provide a resin composite that is excellent in water resistance and is capable of exerting sufficient strength even under wet conditions. The present invention relates to a resin composite comprising a resin, fibers having an ionic functional group, and a polyvalent ion. The fibers having an ionic functional group are preferably cellulose fibers having a fiber width of 1000 nm or less.

Abstract: It is an object of the present invention to provide a resin composite that is excellent in water resistance and is capable of exerting sufficient strength even under wet conditions. The present invention relates to a resin composite comprising a resin, fibers having an ionic functional group, and a polyvalent ion. The fibers having an ionic functional group are preferably cellulose fibers having a fiber width of 1000 nm or less.

Abstract: An object of the present invention is to improve the strength of a sheet containing substituent-introduced ultrafine fiber under high-humidity conditions while maintaining its high transparency. The sheet of the present invention comprises ultrafine fiber having an ionic substituent, and a divalent or higher metal, and has a haze of 10.0% or less.

Abstract: It is an object of the present invention to provide an ultrafine cellulose fiber-containing sheet that is excellent in terms of weather resistance. The present invention relates to a sheet comprising cellulose fibers having a fiber width of 1000 nm or less, wherein the cellulose fibers have anionic functional groups, and the YI increase percentage calculated according to the following equation is 1500% or less. YI increase percentage (%)=(yellowness of the sheet after heating?yellowness of the sheet before heating)/yellowness of the sheet before heating×100, wherein the yellowness of the sheet after heating is a yellowness measured in accordance with JIS K 7373, after the sheet is subjected to hot pressing at 180° C. at 0.5 MPa for 1 minute, whereas the yellowness of the sheet before heating is a yellowness measured in accordance with JIS K 7373, before the sheet is subjected to the hot pressing.

Abstract: It is an object of the present invention to provide a composite sheet, which achieves all of water repellency, water resistance, transparency and mechanical strength. The present invention relates to a sheet having a fiber layer and a coating layer on the fiber layer, wherein the fiber layer comprises ultrafine cellulose fibers having a fiber width of 1000 nm or less in an amount of 60% by mass or more, the haze of the sheet is 20% or less, and the water contact angle of the surface of the sheet on the side of the coating layer which is measured 30 seconds after completion of the dropping of distilled water is 70 degrees or more.

Abstract: The purpose of the present invention is to provide a sheet in which generation of cracks is suppressed when it is bent. The present invention relates to a sheet comprising pulp-derived cellulose fibers having a fiber width of 1000 nm or less and a polyvinyl alcohol-based resin, wherein the sheet has a tensile strength of 15 MPa or more.

Abstract: It is an object of the present invention is to provide a sheet containing ultrafine cellulose fibers, which is excellent in transparency and water resistance. The present invention relates to a sheet including cellulose fibers having a fiber width of 1000 nm or less, and polyamine polyamide epihalohydrin, wherein the haze of the sheet is 6% or less.

Abstract: It is an object of the present invention to provide a resin composite that is excellent in water resistance and is capable of exerting sufficient strength even under wet conditions. The present invention relates to a resin composite comprising a resin, fibers having an ionic functional group, and a polyvalent ion. The fibers having an ionic functional group are preferably cellulose fibers having a fiber width of 1000 nm or less.

Abstract: It is an object of the present invention to provide a composite sheet, which achieves all of water repellency, water resistance, transparency and mechanical strength. The present invention relates to a sheet having a fiber layer and a coating layer on the fiber layer, wherein the fiber layer comprises ultrafine cellulose fibers having a fiber width of 1000 nm or less in an amount of 60% by mass or more, the haze of the sheet is 20% or less, and the water contact angle of the surface of the sheet on the side of the coating layer which is measured 30 seconds after completion of the dropping of distilled water is 70 degrees or more.

Abstract: An object of the present invention is to improve the strength of a sheet containing substituent-introduced ultrafine fiber under high-humidity conditions while maintaining its high transparency. The sheet of the present invention comprises ultrafine fiber having an ionic substituent, and a divalent or higher metal, and has a haze of 10.0% or less.