Rohm Co., Ltd.

Mitsubishi Chemical Corporation

Pioneer Corporation

Hitachi, Ltd.

Kyoto University

Nippon Telegraph and Telephone Corporation

Tottori University

Omura Toryo Co., Ltd.

Masaya Nogi

Hiroyuki Yano

Shinsuke Ifuku

Keishin Handa

Akira Nagai

Yoshitaka Takezawa

Takashi Kurihara

Takao Miwa

Toshiyuki Miyadera

Tohru Maruno

Tohru Matsuura

Junji Sugiyama

Shin-ichiro Iwamoto

Nobutatsu Koshoubu

Noriyuki Shimoji

Yoshiaki Oku

Suguru Okuyama

Hiroyuki Saimoto

Fumiaki Nakatsubo

Yoshihiko Omura

Kentaro Abe

Kentarou Abe

Provided is a nanofiber sheet that sufficiently refined by fibrillation and has high crystallinity of cellulose fiber and can realize a fiber-reinforced composite material exhibiting high transparency, a high elastic modulus, a low coefficient of linear thermal expansion, and high heat resistance and being high in flatness and smoothness. This nanofiber sheet includes crystalline cellulose as the main component and a lignin in an amount of from 10 ppm to 10 wt %. When a fiber/resin composite material obtained by impregnating the nanofiber sheet with tricyclodecane dimethacrylate, subjecting the impregnated product to UV-curing at 20 J/cm, and heating the cured product in vacuum at 160&#xb0; C. for two hours includes 60 wt % of the cured tricyclodecane dimethacrylate and 40 wt % of nanofiber, the following physical characteristics (i) to (iii) are satisfied: (i) the parallel light transmittance of light of a wavelength of 600 nm at a sheet thickness of 100 &#x3bc;m is 70% or more; (ii) the Young's modulus is 5.0 GPa or more; and (iii) the coefficient of linear thermal expansion is 20 ppm/K or less.

Nanofiber sheet, process for producing the same, and fiber-reinforced composite material

A nanofiber sheet that has a high degree of transparency, a high modulus of elasticity, a low coefficient of linear thermal expansion as well as high degrees of flatness and smoothness, in particular, a nanofiber sheet produced as a uniform and flat sheet having a high optical transmittance with cellulose as the only component. This sheet has the following characteristics: Calculated for a thickness of 60 &#x3bc;m, the transmittance for parallel rays of light having a wavelength of 600 nm is equal to or higher than 70%; The Young's modulus measured in accordance with the JIS K7161 method is equal to or greater than 10 GPa; The coefficient of linear thermal expansion measured in accordance with the ASTM D606 method is equal to or smaller than 10 ppm/K.

Nanofiber sheet and method for manufacturing the same

The present invention provides a method for producing chitin nanofibers, which includes the steps of deproteinizing a material derived from a chitin-containing organism by an alkali treatment, deashing a deproteinized integument by an acid treatment, optionally treating the deashed integument under acidic conditions, and then subjecting to a fiber-loosening treatment. The present invention also provides chitin nanofibers obtained by the method, and a composite material and a coating composition each containing the same. The present invention provides a method for producing chitosan nanofibers, which includes, in addition to the above steps, a deacetylation step and chitosan nanofibers obtained by the method, and a composite material and a coating composition each containing the same.

Method for producing chitin nanofibers, composite material and coating composition each containing chitin nanofibers, and method for producing chitosan nanofibers, composite material and coating composition each containing chitosan nanofibers

A highly transparent fiber composite material is provided that can be manufactured through a simplified process using reduced amounts of raw materials and that has high flexibility and low thermal expansivity and retains good functionality of the fiber material. The fiber composite material includes: a fiber assembly having an average fiber diameter of 4 to 200 nm and a 50 &#x3bc;m-thick visible light transmittance of 3% or more; and a coating layer that coats and smoothes the surface of the fiber assembly, wherein the fiber composite material has a 50 &#x3bc;m-thick visible light transmittance of 60% or more. With this fiber assembly, the scattering of light caused by the irregularities on the surface can be suppressed by coating the surface with the coating layer to smooth the surface, whereby a highly transparent fiber composite material can be obtained.

Fiber composite material and method for manufacturing the same

Disclosed is a highly transparent fiber-reinforced composite material including an assembly of cellulose fibers of 4 to 200 nm average fiber diameter impregnated with a matrix material so as to not only remedy the moisture absorbency attributed to cellulose fibers but also further improve transparency. There is provided a fiber-reinforced composite material including an assembly of cellulose fibers impregnated with a matrix material. In the fiber-reinforced composite material, hydroxyl groups of cellulose fibers are chemically modified through a reaction with one or more chemical modifiers selected from the group consisting of an acid, an alcohol, a halogenating reagent, an acid anhydride, and an isocyanate so that the ratio of a functional group introduced by the chemical modification is 5 to 40 percent by mole based on the hydroxyl groups of cellulose fibers before the chemical modification. The chemical modification of hydroxyl groups of cellulose fibers can reduce the hydrophilicity of cellulose fibers to thereby reduce the moisture absorbency of fiber-reinforced composite material. Further, the affinity between cellulose fibers and matrix material can be enhanced to thereby further improve transparency.

Fiber-reinforced composite material and process for producing the same

The present invention relates to a fiber-reinforced composite material and a method for manufacturing the same, and also relates to a transparent multilayered sheet, a circuit board, and an optical waveguide.

Fiber-reinforced composite material, method for manufacturing the same, and applications thereof

There is provided a fiber-reinforced composite material containing fibers having an average fiber diameter of 4 to 200 nm and a matrix material, the composite material having a visible light transmittance of 60% or more at a wavelength of 400 to 700 nm, which is a conversion value based on a thickness of 50 &#x3bc;m. A fiber-reinforced composite material composed of a matrix material and a fiber aggregate impregnated therewith is provided, in which when a segment length of a bright region corresponding to a pore region of the fiber aggregate is represented by L, which is obtained by statistical analysis of a unidirectional run-length image formed from a binary image obtained by binarization of a scanning electron microscopic image of the fiber aggregate, the total length of segments that satisfy L&#x2267;4.5 &#x3bc;m is 30% or less of the total analyzed length. A transparent multilayered sheet, a circuit board, and an optical waveguide are provided which use a transparent substrate formed from this fiber-reinforced composite material.

Fiber-reinforced composite material, method for manufacturing the same and applications thereof

Growing community of inventors

Kyoto, Japan

Masaya Nogi