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.

Provided is a polymer material containing at least one kind of a cellulose derivative having (a) an organosilyl group (the organosilyl group having a first aliphatic group, an unsaturated aliphatic group, or an aromatic group), and (b) an acyl group or a second aliphatic group.

The present invention provides a method for the production of chemically derivatized nanocellulose, comprising the step of a. contacting a precursor cellulosic material with a chemically derivatizing composition to form a liquid reaction mixture, and b. chemically reacting the formed liquid reaction mixture, and c. subjecting the formed liquid reaction mixture to microfluidisation, wherein the steps b. and c. are carried out simultaneously.

The invention relates to systems and techniques for manufacturing articles containing cellulosic material, a coupling agent, and a binder resin, and related processes of making and using the cellulosic articles. In particularly exemplary embodiments, the manufactured articles are door skins, sometimes known as door facings, and doors made from the door skins. The article contains a lipophilic cellulosic material, a coupling agent, and a binder. The coupling agent is believed to increase the hydrophilicity (wetability) of the lipophilic cellulosic material.

The problem to be solved by the present invention is to provide a separation film mainly comprising a cellulose-based resin having high permeability. The present invention pertains to a separation film containing a cellulose ester, wherein the separation film is provided with a bicontinuous structure comprising voids and phases containing the cellulose ester, and the width of the voids is 1 to 200 nm inclusive.

Objects of the present invention are to provide a film for an agricultural greenhouse that can maintain a CO.sub.2 concentration necessary for the photosynthesis of plants even when ventilation is not performed and to provide an agricultural greenhouse using the film. The film for an agricultural greenhouse of the present invention is a cellulose film which contains a cellulose acylate resin and has an equilibrium moisture content of 4% to 8% at a temperature of 25 C., a relative humidity of 80% and a thickness of 60 to 200 m.

The invention relates to systems and techniques for manufacturing articles containing cellulosic material, a coupling agent, and a binder resin, and related processes of making and using the cellulosic articles. In particularly exemplary embodiments, the manufactured articles are door skins, sometimes known as door facings, and doors made from the door skins. The article contains a lipophilic cellulosic material, a coupling agent, and a binder. The coupling agent is believed to increase the hydrophilicity (wetability) of the lipophilic cellulosic material.

Provided are: a novel retardation film which has low photoelastic coefficient, while having good linear thermal expansion coefficient and water absorption; and the novel retardation film which additionally has high heat resistance. The above-described problem is solved by a retardation film which has an absolute value of the linear thermal expansion coefficient of 100 ppm/ C. or less, a glass transition temperature of 180 C. or more, a photoelastic coefficient of from 510.sup.12 m.sup.2/N to 3010.sup.12 m.sup.2/N and a water absorption of 2.0 wt % or less, or a retardation film which has an absolute value of the linear thermal expansion coefficient of 100 ppm/ C. or less, a photoelastic coefficient of from 510.sup.12 m.sup.2/N to 3010.sup.12 m.sup.2/N and a water absorption of 2.0 wt % or less.

The present application discloses regioselectively substituted cellulose esters, films made from the regioselectively substituted cellulose esters and methods for making the same. The regioselectively substituted cellulose esters are synthesized using trifluoroacetic anhydride and cellulose with various acyl donors or acyl donor precursors.

The present application discloses regioselectively substituted cellulose esters, films made from the regioselectively substituted cellulose esters and methods for making the same. The regioselectively substituted cellulose esters are synthesized using trifluoroacetic anhydride and cellulose with various acyl donors or acyl donor precursors.