摘要:
To provide a cellulose acetate which gives a cellulose acetate optical film exhibiting optical properties as a result of stretching, in which the film shows excellent stretchability and gives a stretched film having excellent optical properties.Disclosed is a cellulose diacetate for a retardation film, having a total degree of acetyl substitution of from 2.27 to 2.56, in which the cellulose diacetate has a polydispersity Mw/Mn of more than 3.0 and 7.5 or less, a degree of substitution at the 6-position of from 0.65 to 0.85, a half height width of acetylation distribution of from 1.0 to 2.3, and a viscosity-average degree of polymerization of 182 or more and 213 or less. The cellulose diacetate for a retardation film preferably has a 6-percent viscosity of from 120 to 230 mPa·s and preferably has a weight-average molecular weight Mw of 205,000 or more and 235,000 or less.
摘要:
To provide a cellulose acetate which gives a cellulose acetate optical film exhibiting optical properties as a result of stretching, in which the film shows excellent stretchability and gives a stretched film having excellent optical properties.Disclosed is a cellulose diacetate for a retardation film, having a total degree of acetyl substitution of from 2.27 to 2.56, in which the cellulose diacetate has a polydispersity Mw/Mn of more than 3.0 and 7.5 or less, a degree of substitution at the 6-position of from 0.65 to 0.85, a half height width of acetylation distribution of from 1.0 to 2.3, and a viscosity-average degree of polymerization of 182 or more and 213 or less. The cellulose diacetate for a retardation film preferably has a 6-percent viscosity of from 120 to 230 mPa·s and preferably has a weight-average molecular weight Mw of 205,000 or more and 235,000 or less.
摘要:
A cellulose ester and film thereof useful for remarkably improving optical properties such as optical isotropy are provided. The cellulose ester is adjusted so that the degree of substitution is from 2.90 to 2.965, the total of degrees of substitution at 2- and 3-positions is not less than 1.97, and the half height width of chemical composition expressed in degree of substitution is not more than 0.09. Such a cellulose ester maybe produced by a method for producing a cellulose ester, which comprises (i) an acylating step for acylating a cellulose with an acylating agent in the presence of a sulfuric acid catalyst, and (ii) a hydrolyzing step for hydrolyzing the acylated product in the presence of a sulfuric acid catalyst, and in which the acylation carried out with from 1.40 to 2.0 molar equivalents of the acylating agent relative to 1 mol of a hydroxyl group in the cellulose in the presence of 6.5 to 9.5 parts by weight of the sulfuric acid catalyst relative to 100 parts by weight of the cellulose in the acylating step (i).
摘要:
Cellulose acetate having a high moldability and low solution viscosity in spite of having a high average degree of polymerization is obtained. The low molecular weight components of cellulose acetate (e.g., CTA having average degree of acetylation of 59.0 to 62.5%) are eluted with a washing solvent to produce a cellulose acetate having a molecular weight distribution Mw/Mn of 1 to 1.7. As the washing solvent, those swell or partially dissolve the cellulose acetate, for example, those which dissolve 0.1 to 30% by weight of cellulose acetate can be used. This solvent includes, for example, a solvent having a solubility parameter .delta. of 7 to 12.5 (ketones, ethers, organic acid, esters, etc.).
摘要:
The present invention provides a cellulose ester in which heat resistance under wet condition is compatible with both releasability and spinnability even when the amount of the residual solvent is small in a casting process. The cellulose ester fulfills the following formula: 0.5
摘要:
This invention provides, in an easy manner, a film-like moulded article which shows a selective reflection of a wavelength and circularly polarized light. A suitable environment for formation of a liquid crystalline phase is prepared by forming a moulded article (thin film-like moulded article) using a cellulose derivative which can form the liquid crystalline phase (e.g. a water-insoluble cellulose derivative such as ethyl cellulose), and allowing the moulded article to absorb a highly volatile organic solvent by contact with its vapour. After formation of the liquid crystalline phase, removal of the organic solvent provides the object moulded article. The thin film-like moulded article can be employed for an optical element of a circular polarized light-generator or a decoration material.
摘要:
The present invention provides a cellulose ester in which heat resistance under wet condition is compatible with both releasability and spinnability even when the amount of the residual solvent is small in a casting process. The cellulose ester fulfills the following formula: 0.5
摘要:
A cellulose acetate solution has cellulose acetate in a solvent. The cellulose acetate has an average acetic acid content in the range of 58.0 to 62.5%. In the first embodiment of the invention, the solvent is a mixture of acetone and another organic solvent. The organic solvent is an ether having 3 to 12 carbon atoms, a ketone having 4 to 12 carbon atom, an ester having 3 to 12 carbon atoms, or an alcohol having 1 to 6 carbon atoms. In the second embodiment, the solvent is the ether, the ketone or the ester. Processes for the preparation of the solution and a cellulose acetate film are also disclosed.
摘要:
Cellulose ester and film thereof useful for remarkably improving optical properties, e.g., optical isotropy. The cellulose ester has a degree of substitution from 2.90 to 2.965, a total of degrees of substitution at 2- and 3-positions ≧1.97, and a half height width of chemical composition expressed in degree of substitution of ≧0.09. The cellulose ester maybe produced by (i) acylating a cellulose with an acylating agent in the presence of a sulfuric acid catalyst, and (ii) hydrolyzing the acylated product in the presence of a sulfuric acid catalyst, wherein the acylation carried out with 1.40 to 2.0 molar equivalents of the acylating agent relative to 1 mol of a hydroxyl group in the cellulose in the presence of 6.5 to 9.5 parts by weight of the sulfuric acid catalyst relative to 100 parts by weight of the cellulose in the acylating step (i).
摘要:
A shaped article is obtained by polymerizing a selectively reflective solution comprising a cellulose derivative and a polymerizable solvent. The cellulose derivative is a cellulose derivative having an alkyl degree of substitution of about 2.2-3, an acyl degree of substitution of about 0-0.8 (preferably 0.1-0.8), and a total degree of alkyl and acyl substitution of about 2.8-3. The cellulose derivative is thus, e.g., a highly substituted alkyl cellulose (ethyl cellylose) or an acylated alkyl cellulose. Moreover, the polymerizable solvent may be a (meth)acrylic monomer (e.g., (meth)acrylic acid). According to the present invention, a shaped article having selective reflectivity with respect to wavelength and circularly polarized light is provided.